Datasets:

baber

/

test

like 0

US-32801581-A

Method of and system for determining particular species of chlorine in a water sample ABSTRACT A technique for determining and distinguishing between specific species of chlorine in a supply of water is disclosed herein along with certain applicable apparatus. In carrying out this technique, one or more water samples are obtained from a larger supply and made to display a pH within a specific range. In a preferred embodiment, a sample is provided for each of the different species of chlorine to be determined. A predetermined amount of hydrogen peroxide is added to each of these samples. If hypochlorous acid and/or hypochlorite (one of the species to be determined) is present in any of the samples, the hydrogen peroxide by itself will react therewith for producing oxygen. If however either monochloramine or dichloramine (other chlorine species) is present, it is necessary to combine the hydrogen peroxide with a certain minimum amount of iodine, preferably in the form of potassium iodide, to produce an oxygen evolving reaction. Dichloramine requires a greater concentration of iodine than monochloramine and, hence, the two can be distinquished from one another. In each case, the produced oxygen is detected for determining whether any or all of these chlorine species are present in the water supply and the amounts thereof. This is a division, of application Ser. No. 200,046 filed Oct. 23, 1980, now U.S. Pat. No. 4,322,215. The present invention relates generally to techniques for analyzing given water supplies for chlorine and more particularly to a technique for determining and distinguishing between different specific species of chlorine in the water supplies. From a water conservation standpoint and particularly for the purpose of protecting fresh water fish it has been found desirable to monitor for specific species of chlorine. Of particular interest are hypochlorous acid and/or hypochlorite (depending upon the pH of the water), monochloramine and dichloramine. It is therefore a specific object of the present invention to provide an uncomplicated, reliable and yet economical technique for determining and distinguishing between these three species of chlorine in a water supply. Another specific object of the present invention is to provide a technique for determining and distinguishing between the particular chlorine species mentioned on a large scale so as to be practical for use by industries producing chlorine containing wastewater. A more general object of the present invention is to provide a technique for determining a single specie of chlorine in a water sample, specifically a chlorine specie which reacts with hydrogen peroxide to produce oxygen, with or without the need for certain other additives. As will be described in more detail hereinafter, the technique disclosed herein is one which requires providing one and preferably more than one water sample from the larger water supply being analyzed and maintaining these samples at a pH within a specific range, preferably between five and eight. A predetermined amount of hydrogen peroxide is added to the sample for causing the latter to react with the particular chlorine specie being sought, if the latter is present, to produce oxygen in the water sample or samples, preferably only dissolved oxygen. If hypochlorous acid and/or hypochlorite, its equivalent (depending upon the pH of the sample or samples), is present, the hydrogen peroxide will react therewith to produce the resultant oxygen without the need for other additives. On the other hand, if either monochloramine or dichloramine is present, for the latter to react with hydrogen peroxide to produce oxygen, it has been found necessary to add certain minimum amounts of iodine, preferably in the form of potassium iodide. In the case of dichloramine, a greater amount of iodine is necessary to produce the desired reaction than for monochloramine, depending upon the specific pH of the water sample. In any event, a suitable device is provided for detecting the oxygen, if produced. In a preferred, practical embodiment a separate water sample is provided for each of the species being analyzed. The present technique for determining and distinguishing between different species of chlorine in one or more water samples will be described in more detail hereinafter in conjunction with the drawings wherein: FIG. 1 is a block diagram illustrating one technique for determining and distinguishing between particular species of chlorine in individual water samples; FIG. 2 is a graphic display illustrating the detection of the specific chlorine species sought in the technique shown in FIG. 1; FIG. 3 is a block diagram illustrating a second technique for determining and distinguishing between the same chlorine species associated with the FIG. 1 technique but using a single water sample; FIG. 4 is a diagrammatic illustration of a preferred system for determining and distinguishing between particular species of chlorine in an overall water supply and specifically a system which is especially suitable for use on a large scale; and FIG. 5 is a view in vertical section of an oxygen sensing device comprising one component of the overall system shown in FIG. 4. As stated briefly above and as will be described in more detail hereinafter, the present invention utilizes hydrogen peroxide (H2 O2) as a primary component in determining and distinguishing between certain species of chlorine in a water supply. These chlorine species consist of hypochlorous acid and/or hypochlorite, monochloramine and dichloramine. In the case of hypochlorous acid and/or hypochlorite, the chlorine/hydrogen peroxide reaction is believed to involve the following steps: H.sub.2 O.sub.2 +HOCl⃡HOOCl+H.sub.2 O (1) HOOCl→H.sup.+ +O.sub.2 +Cl.sup.- (2) In reaction step (1) above, whether hypochlorous acid and/or hypochlorite is present in the water sample depends upon the pH of the latter. If the pH is about eight or greater, hypochlorite will be present for the most part with little if any hypochlorous acid. At lower pH values, greater amounts of hypochlorous acid is present as opposed to hypochlorite. In this regard, since hypochlorite and hypochlorous acid are actually one in the same specie depending upon the pH of the water sample, for purposes of simplicity both will be referred to merely as hypochlorite with the understanding that the two may be present, either alone or together, depending upon the pH of the particular water sample in question. In any event, this specific chlorine specie is reduced by hydrogen peroxide to ultimately produce oxygen, without the need for any other additives, as seen in reaction step (2). As a result of this reaction, a suitable device can be provided for detecting the oxygen and thereby monitoring the presence or absence of hypochlorous acid and/or hypochlorite, as will be discussed in more detail hereinafter. In a preferred embodiment of the present invention, the amount of hydrogen peroxide initially provided is selected so that all of the oxygen produced is dissolved in the water sample so that an appropriate device, specifically a commercially available amperometric oxygen probe can be used to detect the dissolved oxygen (referred to as pO2 ) if present and the quantity present. In this latter regard, it is important to determine the quantity of oxygen produced since this value corresponds directly to the amount of hypochlorite in the sample. More specifically, as will be discussed in more detail below, it has been found that the steady state production of oxygen (ΔpO2) and the initial rate response (ΔpO2 /sec) are directly related to chlorine concentration. Because of this, it should be apparent that the measurements must be carried out under anaerobic reaction conditions. In performing various analytical tests relating to the reaction of hydrogen peroxide and hypochlorite, it was not only determined that there is a quantitative relationship between the hypochlorite present and the dissolved oxygen produced but that both the steady state and initial rate measurements are strongly pH dependent, so long as the pH of the water sample is at approximately eight or below. Within this pH range the greatest increase occurs between a pH of five and eight. Beyond a pH of eight, the O2 formation reaction is pH independent and hence is preferred. In any event, it has been found desirable to control the pH of the sample, preferably at a fixed value between a pH of five and eight and most preferably at a pH of about eight. This may be accomplished by providing a standard buffer solution at the desired pH and combining this solution in sufficient quantity with the sample in question so that the latter (e.g. the combination) displays the same pH. In further evaluating the reaction between hydrogen peroxide and water samples containing hypochlorite, it was found that at a fixed hydrogen peroxide concentration (1.0 mM), the increase in steady state pO2 changes linearly with hypochlorite solution. Initial rate experiments carried out at a constant hydrogen peroxide concentration and variable hypochlorite concentration were used to generate log (initial rate) versus log (HOCl) plots. These plots exhibited a slope of 1.0 for samples at both a pH of eight and at a pH of five, indicating that the reaction is indeed first order with respect to hypochlorite species. A similar experiment was carried out for a constant HOCl concentration and a variable hydrogen peroxide concentration. The results of the latter experiment indicated a first order reaction with respect to the hydrogen peroxide. With further reference to the reaction between hydrogen peroxide and hypochlorite, it has been found that a preferred technique for determining whether or not hypochlorite is present in a water sample (and the amount if present) utilizes a sufficient amount of hydrogen peroxide to provide a concentration level of 10-3 M. In this preferred technique, the sample itself is maintained at a pH of eight in a phosphate buffer. Responses to hypochlorite using this technique were observed down to 0.03 ppm Cl in the sample tested. An upper detection limit of approximately 75 ppm Cl has also been observed. This upper detection limit is due to oxygen solubility limitations, i.e., at [OCl- ] greater than 75 ppm, the solution becomes oxygen saturated, resulting in additionally produced oxygen leaving the solution. If the overall detection scheme is capable of not only measuring the dissolved oxygen but also free oxygen gas in the case where the sample is saturated, the present technique would not necessarily be confined to an upper limit. In contrast to the foregoing reaction between hydrogen peroxide and hypochlorite (or hypochlorous acid), no reaction occurs between hydrogen peroxide and either monochloramine or dichloramine in the absence of iodine, preferably in the form of potassium iodide (KI). More specifically, it has been found that in the presence of small amounts of potassium iodide (10-3 M), monochloramine rapidly oxidizes hydrogen peroxide. In the presence of monochloramine and potassium iodide, the hydrogen peroxide oxidation reaction is believed to involve the following steps: NH.sub.2 Cl+2I.sup.- →H.sup.+ I.sub.2 +NH.sub.4.sup.+ +Cl.sup.-(3) I.sub.2 +H.sub.2 O.sub.2 →O.sub.2 +2I.sup.- +2H.sup.+(4) From reaction step (4) above, it should be apparent that the reaction just described results in the production of oxygen gas. In initial work done in this area, it was found that at fixed hydrogen peroxide and potassium iodide concentrations, the initial rate response (ΔpO2 /sec) as well as the steady state response (ΔpO2) were found to change linearly with monochloramine concentration. At fixed hydrogen peroxide and monochloramine concentrations, the initial rate of ΔpO2 was found to be linearly related to the potassium iodide concentration whereas the steady state response was found to be independent of potassium iodide concentration. In the absence of monochloramine, no O2 was generated in a buffer solution (pH 8.0) containing both hydrogen peroxide and potassium iodide. Initial rate experiments carried out at constant H2 O2 and KI concentrations with variable NH2 Cl concentrations were used to generate log (initial rate) versus log (NH2 Cl) plot. The plot exhibited a slope of 1.0 at pH 8.0, indicating that the reaction is first order with respect to NH2 Cl. In addition, in this initial work, it was learned that monochloramine and dichloramine can be differentiated by the pH of the sample containing these chlorine species and the potassium iodide concentration provided. In subsequent experiments it was observed that a linear signal (quantities of oxygen produced) is generated in accordance with the concentration level of the monochloramine for concentrations ranging from 0.08 to 5 ppm Cl. The signal measured for monochloramine has been found to have no contribution for dichloramine so long as the potassium iodide concentration level remains at or below a certain level, specifically about 10-3 M in the samples tested. On the other hand, by providing a greater concentration of potassium iodide, specifically a concentration level of about 5×10-2 M, in a sample displaying a pH of about eight, the dichloramine, if present, reacts with the hydrogen peroxide to produce oxygen in the same manner as monochloramine and hypochlorite. In an actual example, a water sample having dichloramine therein was maintained at a pH of 8.0 using a phosphate buffer and sufficient hydrogen peroxide was provided to maintain a concentration level of 10-3 M. In addition, sufficient potassium iodide was provided for maintaining a concentration level of about 10-2 M. This resulted in the observation of a linearity of signal versus concentration of dichloramine from 0.2 to 0.7 ppm Cl. With further reference to the reaction between hydrogen peroxide and the chloramine species, it should be apparent that both can be distinguished from hypochlorite (or hypochlorous acid) by adding a certain minimum amount of iodine to the sample. It should also be apparent that monochloramine and dichloramine can be distinguished from one another by the amount of iodine used. While an exact amount of iodine and hydrogen peroxide necessary to accomplish this along with a particular pH of the solution have been suggested, it should be apparent that variations of one or all of these parameters will cause the others to vary. For example, a lower pH than eight for the solution may cause a change in the concentration levels of potassium iodide necessary to make the appropriate distinctions. Nevertheless, one could readily determine these parameters based on the teachings herein. Having described the foregoing ways of determining and distinguishing between the three specific chlorine species discussed above in a water sample, attention is now directed to various suggested systems for carrying out this technique. To this end, reference is first made to FIG. 1 which illustrates one such system generally designated by the reference numeral 10. As seen there, this system includes three distinct water samples S-1, S-2 and S-3 which may be taken from a single larger supply (not shown). Each of these samples is combined with a buffer solution to maintain its pH at a desired level, for example at eight, as indicated in FIG. 1. In the case of sample S-1, the prescribed amount of hydrogen peroxide alone is added thereto. This particular solution is free of any iodine. As a result, only the hypochlorite and/or hypochlorous acid, if present, and the hydrogen peroxide react to produce the previously described oxygen. In the case of sample S-2, both hydrogen peroxide and potassium iodide in the prescribed amounts are introduced therein for causing the hypochlorite and/or monochloramine, if present, to react with the hydrogen peroxide to produce its own resultant oxygen. Finally, in the case of the sample S-3, the prescribed amounts of hydrogen peroxide and potassium iodide are provided therein for causing the hypochlorite, monochloramine and dichloramine to react with the hydrogen peroxide for producing its own oxygen. System 10 also includes an oxygen detector 12 which will be discussed in more detail hereinafter with respect to FIGS. 4 and 5. For the moment, it should suffice to say that this detector serves to detect oxygen produced as a result of the previously described reactions in samples S-1, S-2 and S-3. In this regard, in order to not only determine which if any of the three previously described chlorine species is present in the water supply used to provide the samples but also the quantities thereof, it is necessary to evaluate each of the samples separately. This is because the oxygen generated as a result of the presence of the species are additive. More specifically, when hydrogen peroxide alone is added to the sample S-1, a specific amount of oxygen is generated, depending upon the amount of hypochlorite and/or hypochlorous acid present. In the graphic illustration of FIG. 2 which shows time versus the peak oxygen level detected by detector 12, the first three peaks correspond to the amount of oxygen detected as a result of the reaction in sample S-1. Note that this peak value is indicated at A. Thereafter, when the prescribed amounts of hydrogen peroxide and potassium iodide are added to sample S-2, the amount of oxygen detected is shown in FIG. 2 to be equal to the level A+B, that is, an amount A contributed by the hypochlorite present and an amount B contributed by the monochloramine. In sample S-3, when the prescribed amounts of hydrogen peroxide and potassium iodide are added, the total amount of oxygen detected is A+B+C, that is, an amount A corresponding to the hypochlorite in the sample, an amount B corresponding to the monochloramine in the sample and an amount C corresponding to the amount of dichloramine. From the foregoing, it should be apparent that if the graphic illustration of FIG. 2 represents oxygen generating reactions sufficient to depleat reproducible amounts of the reacting chlorine species in the various samples S-1, S-2 and S-3, a quantitative analysis of these species can be made. More specifically, from the analysis of sample S-1, the exact amount of hypochlorite and/or hypochlorous acid can be determined. From sample S-2, the amount of this latter specie and monochloramine together can be determined and therefore, based on the results of sample S-1, the amount of monochloramine alone can be determined. In the same manner, from sample S-3, the amount of dichloramine alone can be determined. As stated above, each sample must be maintained at a specific pH, preferably at about eight, a sufficient amount of hydrogen peroxide must be provided and the proper amount of potassium iodide must also be used, depending upon whether monochloramine or dichloramine is being sought. Referring to FIG. 3, attention is directed to a second system 14 for accomplishing the same end result as system 10, that is, for determining and distinguishing between the three previously described chlorine species in a water supply. In system 14, a single sample S-1 is initially provided at a precontrolled pH level, as indicated diagrammatically by the pH buffer added thereto. Like system 10, the sample S-1 in system 14 is combined with only hydrogen peroxide (in the absence of potassium iodide) so to cause an oxygen producing reaction between the hydrogen peroxide and hypochlorite, if the latter is present. The oxygen produced is detected by the same type of detector 12 used in system 10 and the results may be graphically illustrated in the same manner shown in FIG. 2, e.g. as the level A shown there. However, instead of providing second and third distinct samples as in system 10, system 14 uses the same samples S-1 to detect for monochloramine and dichloramine. In the case of monochloramine, after the hypochlorite has been detected for, hydrogen peroxide in the prescribed amount is again provided in the sample (assuming an excess amount was not initially added) in combination with the prescribed amount of potassium iodide for causing all of the monochloramine to react therewith for producing oxygen. This oxygen is also detected but unlike system 10, the amount detected in system 14 corresponds only to the monochloramine (amount B in FIG. 2) since the hypochlorite has already been exhausted. In order to test for dichloramine, the same sample is thereafter provided with still another prescribed amount of hydrogen peroxide (again assuming an excess is not present) in combination with the prescribed amount of potassium iodide for causing all of the dichloramine in the sample to react for producing oxygen. This oxygen is detected and corresponds only to the amount of dichloramine present in the sample (e.g., the amount C). Referring now to FIG. 4, attention is directed to still another system for determining and distinguishing between the previously described chlorine species and specifically a system which is especially suitable for use in large scale. This system which is generally indicated by the reference numeral 16 includes a reservoir 18 for containing a water sample to be analyzed therein. This container may be designed to house a discrete sample or, as indicated diagrammatically at 20, it may be designed for housing a continuously periodically replenished sample from a larger water supply not shown. A separate reservoir 22 containing a buffer solution at a predetermined pH is placed in fluid communication with container 18 for combining the buffer solution with the sample for maintaining the pH level of the combination at a predetermined level, for example at a pH of eight. A subsample of the combination sample just described is pumped or otherwise conveyed through tube means 19 by suitable means 24 into an injection valve 26. As shown in FIG. 4, the means 24 is a peristaltic pump. The injection valve may be constructed of any suitable means capable of injecting hydrogen peroxide and/or potassium iodide into the subsample as the latter passes therein. In a preferred embodiment, system 16 includes three separate and distinct reservoirs 28, 30 and 32 for respectively containing hydrogen peroxide alone, hydrogen peroxide in combination with potassium iodide (at a prescribed concentration level) and hydrogen peroxide in combination with potassium iodide (at a different prescribed concentration level). Suitable means generally indicated at 34 including an appropriate metering valve generally indicated at 36 and control components (not shown) are provided for alternatively placing the three reservoirs 28, 30 and 32 in fluid communication with the injection valve 26 for selectively metering predetermined amounts of the additives contained in these reservoirs into the subsample passing into the injection valve. For example, in the case of a first subsample, the valve 36 can be controlled to cause the prescribed amount of hydrogen peroxide from reservoir 28 to be injected into the subsample as the latter passes into the injection valve. At the same time, the buffer could and preferably would be combined with the subsamples at valve 26 rather than at reservoir 18, as indicated by dotted lines in FIG. 4. The means 24 thereafter causes the subsample to pass into oxygen sensor 38 which will be described in more detail with respect to FIG. 5. This oxygen sensor serves to detect the amount of oxygen produced as a result of the reaction between the hydrogen peroxide and any hypochlorite in the subsample. A conventional potentiostat 40 is coupled to the sensor and serves as a transducer for converting the detected oxygen to an electrical current which, in turn, is used to drive a readout 42 for providing a visual and/or permanent display corresponding to the amount of oxygen detected. The first subsample is thereafter pumped or otherwise delivered into a waste container 44. Having quantitatively analyzed the first subsample of water for hypochlorite, as described above, pump 24 serves to direct a second subsample through to injection valve 26. At the same time, means 34 controls metering valve 36 so as to cause the prescribed amount of hydrogen peroxide and potassium iodide to be injected from the reservoir 30 into the injection valve so as to mix with the second subsample. This second subsample then passes into the oxygen sensor 38 where the oxygen generated thereby is detected and readout. The second subsample is then pumped into waste container 44. This procedure is again repeated for a third subsample. However, in this latter case, means 34 causes the injection valve 36 to inject the prescribed amount of hydrogen peroxide/potassium iodide from container 32 into the injection valve while the third sample is therein. This mixture is immediately thereafter pumped into the oxygen sensor where the generated oxygen is detected and readout. Finally, the third sample is pumped into waste container 44. From the foregoing, it should be apparent that overall system 16 functions in the same way as previously described system 10 to provide corresponding levels of detected oxygen A, A+B and A+B+C so that hypochlorite, monochloramine and dichloramine can be quantitatively determined. Referring now to FIG. 5, attention is directed to a specific oxygen sensor which, as stated previously, is preferably a commercially available amperometric oxygen probe. This probe is shown including a stainless steel base 46 definiing an inner chamber 48 in the form of a through channel for receiving and passing therethrough the previously described subsamples of water from container 18. In this regard, opposite ends of the chamber 48 are placed in fluid communication with enlarged, internally threaded bores 50 adapted to receive cooperating ends of tube means 19 serving to carry the flow of sample water as described above. Probe 38 includes a main body 52 fixedly connected with base 46 for containing an oxygen permeable membrane 54 and the previously described potentiostat 40. The membrane itself is constructed of a suitable material, for example Teflon (a trademark of DuPont) and extends entirely across the bottom opening of an overall chamber 56 defined by space 46 in combination with main body 52. The membrane cooperates with the subsample located within chamber 48 to cause the oxygen produced therein to pass into chamber 56. Potentiostat 40 is located within chamber 56 and is comprised of an anode 58, a cathode 60 and an aqueous solution of potassium chloride 62 within its own container 64. These components in conjunction with suitable electronic components (not shown) contained within housing 66 convert the oxygen entering chamber 56 into a corresponding parent signal for driving previously recited readout 42. At stated previously, the entire probe and potentiostat belong with the readout device and previously described pump 24 and injection valve 26 may be conventional components. This is equally true of means 34 including its metering valve 36 and the control means associated therewith. Moreover, while not shown, a suitable means for detecting O2 gas (out of solution) could be readily provided if the samples are analyzed in excess of their O2 saturation levels. What is claimed is: 1. A system for determining chlorine species from a group consisting of hypochlorous acid and/or hypochlorite, monochloramine and dichloramine in respective first, second and third samples of a larger supply of water, said system comprising: means for providing each of said samples at a pH within a specific range; first container means including a supply of hydrogen peroxide and second container means including a supply of potassium iodide; means for transferring from said first container means to said first water sample a predetermined amount of hydrogen peroxide such that said first sample is free of potassium iodide whereby said hypochlorous acid and/or hypochlorite if present will react with said hydrogen peroxide to produce oxygen but said monochloramine and dichloramine if also present will not react with said hydrogen peroxide to produce oxygen; means for transferring from said first container means to said second water sample a predetermined amount of hydrogen peroxide and from said second container means to said second water sample a first predetermined amount of potassium iodide for causing said monochloramine and not said dichloramine to react with said hydrogen peroxide and potassium iodide for producing additional oxygen; means for transferring from said first container means to said third water sample a predetermined amount of hydrogen peroxide and from said second container means to said third water sample a second predetermined amount of potassium iodide for causing said dichloramine to react with said hydrogen peroxide and said potassium iodide for producing still further oxygen; and means for detecting from each of said sample oxygen for indicating whether or not any of said chlorine species are present in said water supply. 2. A system according to claim 1 wherein each of said transferring means includes a single common arrangement for alternatively transferring the hydrogen peroxide and potassium iodide from said first and second container means into the first, second and third samples. 3. A system according to claim 2 wherein said second container means includes two separate containers for potassium iodide.

1981-12-07

en

1983-07-05

US-66962296-A

IC card ABSTRACT An IC card that allows fixing the obverse and reverse metal panels to the plastic frame without using adhesion and allows to make conducting electrically between both the metal panels. The IC card 1 includes an electrical circuit board 3 in which electronic components 4 are incorporated, a connector 5 to be connected to an end portion of the electric circuit board, a frame 2 which constitutes an outer frame of the card and a pair of metal panels 6, 7 which cover an obverse and reverse sides of the card. A plurality of tongues 6c, projecting pieces 7c being able to engage with each other are provided on side edge portions of the metal panels 6,7 respectively, while, a plurality of slits into which the projecting pieces 7c of the lower metal panel 7 are to be pressed are provided in the frame 2, and, the projecting pieces 7c are pressed into the slits, also, corresponding tongues 6c of the upper metal panel 6 are engaged with the projecting pieces 7c respectively in a condition of being subject to elastic force of the metal panels. FIELD OF THE INVENTION The present invention relates to an IC card and a manufacturing method thereof. DESCRIPTION OF THE PRIOR ART Formerly, in what we call IC card, such a construction is employed widely in general, that inner parts such as an electrical circuit board in which prescribed electronic components etc. being incorporated are arranged in a frame and their obverse and reverse sides are covered by a pair of metal panels. In the specification, the term of "IC card" indicates card-like or plate-like device being provided with electronic circuits including semiconductor circuits or electric circuits, and cards provided with same basic constitution, being called as various other different names, for example, PC card, modem card, LAN card or electronic card etc., are also included. Now, an example of a conventional basic construction and a manufacturing method of such an IC card will be concretely explained with reference to the drawings. FIG. 23 is a disassembled perspective view of a conventional IC card 101. As shown in this figure, said IC card 101 comprises a frame 102 made of plastic which forms an outer frame of a card body, an electric circuit board 103 in which prescribed electronic components etc. 104 are incorporated, a connector 105 to be mounted to an end portion of the electric circuit board 103, and, a pair of metal panels 106,107 which cover respectively an obverse and reverse sides of the IC card 101 including the electric circuit board 103 and the connector 105. Said connector 105 is for obtaining an electrical connection with equipment (for example, a personal computer etc.) in which the IC card 101 is used. In assembling the IC card 101, at first, the connector 105 is to be mounted to the end portion of the electric circuit board 103 on which the electronic components etc.104 are mounted, and, the connector 105 is to be connected to the electric circuit board 103 electrically and mechanically, for example, by means of soldering etc., then, a kind of module 108(card module) is constituted. After setting this card module 108 to the frame 102 in the determined position, the metal panels 106,107 are fitted from the obverse and reverse side thereof respectively, and fixed to the frame 102 by means of adhesion. By this, the IC card 101 having the card module 108 built-in, as shown in FIG. 24 and FIG. 25, is assembled as one body. That is to say, formerly, an adhesive sheet is placed between each metal panel 106,107 and the frame 102, and, by its adhesive force, each metal panel 106, 107 is fixed to the obverse and reverse sides of the frame 102. In this case, in order to make the adhesion of the adhesive sheet to generate a required adhesive force, it is required to keep a predetermined temperature (for example, about 150 c), and to apply a predetermined pressure (for example, about 50 Kg) in assembling process. Therefore, in assembling the IC card 101, a special equipment which can acts a press force in the temperature controlled condition, also, there is a problem that the assembling work takes much time. With regard to such a problem, for example, in Japanese patent Laid-open Publication No. Hei 3-45397 or Hei 7-160837 (hereinafter, these are named prior art 1, prior art 2), such a construction is disclosed, that a plurality of projections (projecting pieces or tongues) are formed by bending works of side edge portions of each metal panel, while slits corresponding to the projections are provided on the obverse and reverse sides of the plastic frame, and by pressing the corresponding projection into each slit, the metal panels are fixed to the frame on the obverse and reverse sides thereof respectively. According to such a construction, it is possible to fix each metal panel to the frame without using adhesion, as the result, the above-mentioned special equipment is not required any more, and, the assembling process can be simplified. By the way, the electronic components etc. mounted on the electric circuit board in the IC card are electrically protected from static electricity impressed from out side by metal panels covering the obverse and reverse sides of the IC card. And, in order to elevate durability against static electricity from out side, it is known to be effective to connect the obverse and reverse metal panels to each other. That is to say, if both the panels are connected electrically, when static electricity is impressed to one metal panel, it is possible to let the static electricity escape through the other metal panel, therefore the durability against static electricity is improved. However, in the prior art 1 and prior art 2, the projections provided to each metal panel are pressed into the plastic frame respectively, and, the obverse metal panel and the reverse metal panel do not contact each other, therefore, there is a problem that it is impossible to make conducting between both the metal panels and improve the durability against static electricity. On the other hand, as a constitution which intends to improve the durability against static electricity by connecting the obverse and reverse metal panels each other, such a construction is known, as disclosed, for example, in Japanese Utility model Laid-open Publication No. Hei 4-63284 or Utility model Laid-open Publication No. Hei 4-77485 (hereinafter, these are named prior art 3, prior art 4), that detentes being able to engage with each other are formed by bending the side edge portions of the obverse and reverse metal panels, while, at corresponding positions to the detentes in the plastic frame, through openings from the obverse side to the reverse side are provided, and by assembling the card, the detentes of the obverse and reverse metal panels are engaged with each other in the through opening, then, the conduction between both the metal panels is obtained However, in this case, the detentes are provided at only a few places (for example 4 per one metal panel), and also, since they are basically to obtain mutual contact by merely engaging, or, to utilize elasticity of the panel detentes for elevating sureness of the contact, an adhesion is required as same as conventional manner in order to fix each metal panel to the plastic frame. As mentioned above, formerly, in the case that each metal panel is fixed to the frame without using adhesion(prior arts 1,2), both the metal panels could not be conducted electrically, on the other hand, in the case that both the metal panels are conducted electrically (prior arts 3, 4), it was impossible to fix each panel to the frame without adhesion. In other words, the actual situation is that it was impossible to achieve, at a time, simplifications of the construction of the IC card and the manufacturing process thereof and improvement of the durability against static electricity. SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned conventional problems, and has objects of providing an IC card and a manufacturing method thereof, which allow to fix the obverse and reverse metal panels to the plastic frame without using adhesion, and at a time, allow to make conducting electrically between both the metal panels. Thus, according to an aspect of the present invention which is developed to achieve the above-mentioned objects, there is provided an IC card comprising an electrical circuit board in which prescribed electronic components etc. are incorporated, a connector to be connected to an end portion of the electric circuit board, a frame which constitutes an outer frame of the card and a pair of metal panels which cover an obverse and reverse sides of the card, wherein; a plurality of projections being able to engage with each other are provided on side edge portions of each metal panels respectively, while, a plurality of slits into which the projections of whichever one metal panel are to be pressed are provided to the frame, and, the projections of said one metal panel are pressed into the slits, also, corresponding projections of the other metal panel are engaged with the projections of said one metal panel respectively in a condition of being subject to elastic force of the metal panels. In the above-mentioned IC card according to the aspect of the invention, since the projections of said one metal panel are pressed into the slits provided to the frame, said one metal panel is fixed by pressing into the frame by means of the pressing force. And, since corresponding projections of the other metal panel are engaged with the projections of said one metal panel respectively in a condition of being subject to elastic force of the metal panels, the other metal panel is secured by engaging to said one metal panel by means of the elastic force. In other words, both the metal panels can be secured to the frame without using adhesion. As the result, the adhesion itself and special equipments to be used in adhesive process are not required any more, and, the assembling process can be much simplified, by these, a reduction of the manufacturing cost of the IC card can be achieved. Also, in this case, since both the metal panels are conducted electrically due to mutual engagements of their projections, the durability against static electricity impressed from out side can be elevated still higher. That is to say, it comes to be possible to secure the obverse and reverse metal panels without using adhesion, and at a time, to conduct both the metal panels electrically, accordingly, reduction of the manufacturing cost and improvement of the endurance against static electricity can be achieved at a time. Further, in the above-mentioned IC card, it is preferable that said one metal panel covers the reverse side of the IC card and the other metal panel covers the obverse side of the IC card, and, the projections of the other metal panel are engaged with the corresponding projections of said one metal panel from out side. In this case, since the projections of the other metal panel covering the obverse side of the IC card are engaged with the corresponding projections of said one metal panel on reverse side of the IC card from out side, the engaging portions between both the projections are covered by the other metal panel, accordingly they can not be observed easily from the obverse side. In other words, it is possible to improve the appearance of the obverse side which attracts people's attention. Still further, in the above-mentioned IC card, it is preferable that a notch opening in a direction along a plane of the IC card is provided to each projection of said one metal panel, and, each projection of the other metal panel engages with the notch, by sliding the other metal panel along a corresponding surface of the frame. In this case, since the engagement between the projections of both the metal panels are obtained by sliding the other metal panel along the corresponding surface of the frame, the assembling work of both the metal panels can be performed relatively easily. Still further, in the above-mentioned IC card, it is preferable that the notch opens toward a reverse side of a portion of the IC card at which the connector is positioned, and, a maximum slide length of the other metal panel is determined to be less than a width of the connector. In this case, since the notch opens toward the reverse side of the portion of the IC card at which the connector is positioned, and the maximum slide length of the other metal panel is determined to be less than a width of the connector, the side edge portion of the connector side in the other metal panel can be slid on the same plane (i.e the surface of the connector) before and after the slide motion, and, it comes to be possible to ensure a smooth slide motion without scratches. Still further, in the above-mentioned IC card, it is preferable that an engaging portion having tapered parts is provided respectively to each projection of both the metal panels. In this case, since the engaging portion having tapered parts is provided respectively to each projection of both the metal panels, when they engage with each other, they can slide mutually in the condition that the tapered parts thereof are combined, and, they can be engaged surely as scatters in mutual dimensions and shapes are being absorbed. Still further, in the above-mentioned IC card, it is preferable that each projection of said one metal panel is formed to be a waisted configuration having a neck portion, and the tapered part of the engaging portion provided to each projection of the other metal panel engages with the neck portion. In this case, since each projection of said one metal panel is formed to be a waisted configuration having a neck portion, and the tapered part of the engaging portion provided to each projection of the other metal panel engages with the neck portion, when they engage with each other, it is possible to obtain an engaged condition by acting the elastic force of the metal panels, after inserting each projection of said one metal panel into the wide area of the tapered part. And, it is possible to engage for fixation of the other metal panel to said one metal panel without applying immoderate force on the other metal panel. Still further, in the above-mentioned IC card, it is preferable that, on the side edge portions of each metal panel, bent portions formed along the side edge by bending a panel material at a predetermined angle are provided, and, the projections of each metal panel are formed so that they project additionally from an edge of the bent portion. In this case, since on the side edge portions of each metal panel, bent portions formed along the side edge by bending a panel material at a predetermined angle are provided, it comes to be possible to raise the rigidity of each metal panel, in comparison with the case that they are designed to be merely flat plate. Still further, in the above-mentioned IC card, it is preferable that the bent portions of both the metal panels are bent by mutually different angles, and the projections of each metal panel project additionally from the edge of the bent portions in the same plane. In this case, since the bent portions of both the metal panels are bent at mutually different angles, and the projections of each metal panel project additionally from the edge of the bent portions in the same plane, the bent portions and the projections are in the same plane, therefore, in bending each metal panel, it is not necessary to bend the panel material in divided two stages, and working process can be simplified. Still further, in the above-mentioned IC card, it is preferable that concavities which contain the engaging portion between the projections of both the metal panel and convexities which can support the other metal panel in a engaging condition thereof. In this case, since the concavities which contain the engaging portion between the projections of both the metal panel and the convexities which can support the other metal panel in the engaging condition thereof, it is possible to engage each projection of both the metal panels mutually without any trouble, and to ensure effectively the supporting rigidity for the other metal panel in that engaging condition. Furthermore, according to another aspect of the present invention, there is provided an manufacturing method of an IC card comprising an electrical circuit board in which prescribed electronic components etc. are incorporated, a connector to be connected to an end portion of the electric circuit board, a frame which constitutes an outer frame of the card and a pair of metal panels which cover an obverse and reverse sides of the card, comprising: a step of forming a card module by mounting the connector to the electric circuit board; a step of fixing by pressing whichever one metal panel into the frame, by pressing a plurality of projections provided to side edge portions of said one metal panel into slits provided to the frame; a step of setting the card module to the frame into which said one metal panel is fixed by pressing; and, a step of combining an other metal panel to said one metal panel fixed by pressing into the frame after the card module being set to the frame, and engaging for securing the other metal panel to said metal panel, by engaging a plurality of projections provided to side edge portions of the other metal panel with corresponding projections of said metal panel in a condition of being subject to elastic force of the metal panels. In the above-mentioned manufacturing method of an IC card according to the aspect of the invention, by pressing a plurality of projections provided to the side edge portions of said one metal panel into the slits provided to the frame, said one metal panel is fixed by being pressed into the frame. And, since corresponding projections of the other metal panel are engaged with the projections of said one metal panel respectively in a condition of being subject to elastic force of the metal panels, the other metal panel is secured by engaging to said one metal panel by means of the elastic force. In other words, both the metal panels can be fixed to the frame without using adhesion. As the result, the adhesion itself and special equipments to be used in adhesive process are not required any more, and, the assembling process can be much simplified, by these, a reduction of the manufacturing cost of the IC card can be achieved. Also, in this case, since both the metal panels are conducted electrically due to mutual engagements of their projections, the durability against static electricity impressed from out side can be elevated still higher. That is to say, it comes to be possible to secure the obverse and reverse metal panels without using adhesion, and at a time, to conduct both the metal panels electrically, accordingly, reduction of the manufacturing cost and improvement of the endurance against static electricity can be achieved at a time. Still further, in the above-mentioned manufacturing method of an IC card, it is preferable that, in engaging for securing the other metal panel to said one metal panel, each projection of the other metal panel is to be engaged respectively with a corresponding projection of said one metal panel, by incurvating the other metal panel toward a predetermined direction within its elasticity. In this case, since in engaging for securing the other metal panel to said one metal panel, each projection of the other metal panel is to be engaged respectively with a corresponding projection of said one metal panel, by incurvating the other metal panel toward a predetermined direction within its elasticity, it is possible to act elastic force on the engaging portion between each projection relatively easily and surely. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features and advantages of the present invention will become clear from the following description taken in conjunction with the preferred embodiment with reference to the accompanying drawings, and in which: FIG. 1 is a disassembled perspective view of the IC card in a first embodiment of the present invention; FIG. 2 is an overall perspective view of the IC card in the first embodiment of the present invention; FIG. 3 is an enlarged perspective view of tongues of an upper metal panel of the IC card in the first embodiment of the present invention; FIG. 4 is an enlarged perspective view of projecting pieces of a lower metal panel of the IC card in the first embodiment of the present invention; FIG. 5 is an enlarged perspective view of concavities and slit of a frame in the first embodiment of the present invention; FIG. 6 is an enlarged perspective view illustrates an engaging condition of tongue and projecting piece in the first embodiment of the present invention; FIG. 7 is a vertical cross-sectional view of the IC card illustrates an engaging condition of tongue and projecting piece in the first embodiment of the invention; FIG. 8 is a vertical cross-sectional view of the IC card illustrates an supported condition of the upper metal panel being supported by the frame in the first embodiment of the invention; FIG. 9 is an overall perspective view of upper and lower metal panels of the IC card in a second embodiment of the invention; FIG. 10 is an enlarged perspective view of projecting pieces of a lower metal panel of the IC card in the second embodiment of the present invention; FIG. 11 is a overall perspective view illustrates an assembled condition of the IC card in the second embodiment of the present invention; FIG. 12 is an enlarged perspective view illustrates an engaging condition of tongue and projecting piece in the second embodiment of the present invention; FIG. 13 is an enlarged vertical cross-sectional view of a rear end portion of the frame in the second embodiment of the present invention; FIG. 14 is an overall perspective view of upper and lower metal panels of the IC card in a third embodiment of the invention; FIG. 15 is an enlarged perspective view of tongues of an upper metal panel of the IC card in the third embodiment of the present invention; FIG. 16 is an enlarged perspective view of projecting pieces of a lower metal panel of the IC card in the third embodiment of the present invention; FIG. 17 is an enlarged perspective view illustrates an engaging condition of tongue and projecting piece in the third embodiment of the present invention; FIG. 18 is a vertical cross-sectional view of the IC card illustrates an engaging condition of tongue and projecting piece in the third embodiment of the invention; FIG. 19 is an overall perspective view of upper and lower metal panels of the IC card in a fourth embodiment of the invention; FIG. 20 is an enlarged perspective view of tongues of an upper metal panel of the IC card in the fourth embodiment of the present invention; FIG. 21 is an enlarged perspective view illustrates an engaging condition of tongue and projecting piece in the fourth embodiment of the present invention; FIG. 22 is a vertical cross-sectional view of the IC card illustrates an engaging condition of tongue and projecting piece in the fourth embodiment of the invention; FIG. 23 is a disassembled perspective view of a conventional IC card; FIG. 24 is an overall perspective view of the conventional IC card; and FIG. 25 is a vertical cross-sectional view of FIG. 24 as taken along line XXV--XXV; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, preferred embodiments of the present invention will be explained in detail with reference to attached drawings. At first, a first embodiment of the invention shown in FIG. 1-FIG. 8 will be explained. FIG. 1 is a disassembled perspective view of an IC card 1 in accordance with the present invention. As shown in this figure, said IC card 1 comprises a frame 2 made of plastic which forms an outer frame of a card body, an electric circuit board 3 in which prescribed electronic components etc.4 are incorporated, a connector 5 to be mounted to an end portion of the electric circuit board 3, and, a pair of metal panels 6,7 which cover respectively an obverse and reverse(upper and lower) sides of the IC card 1 including the electric circuit board 3 and the connector 5. Said connector 5 is for electrical connection signal communication with an equipment(for example, a personal computer etc.) in which the IC card 1 is used, and locates on one side face(front side face) of the IC card 1. Also, the electronic components etc.4 and the connector 5 are electrically and mechanically connected to the electric circuit board 3 by means of for example soldering etc. Thus, the electric circuit board 3 to which the electronic components etc.4 and connector 5 are mounted as one body is named card module 8. In assembling the IC card 1, at first, the connector 5 is to be mounted to an end portion of the electric circuit board 3 on which the electronic components etc. 4 are mounted, and, the connector 5 is to be connected to the electric circuit board 3 electrically and mechanically, for example, by means of soldering etc., then, the card module 8 is constituted. And, by a method which will be explained in detail later, one (the lower side in the figure) metal panel 7 is pressed into the plastic frame 2 for fixation. And, the card module 8 is to be set in the plastic frame 2, and at last, the other (the upper side in the figure) metal panel 6 is combined with the frame 2 in which the card module 8 is set, and, engaged for fixation with the lower metal panel 7 being pressed into the frame 2 for fixation, by a method which will be explained later. As mentioned above, one IC card 1 having the card module 8 built-in is assembled as one body, as shown in FIG. 2, without using adhesion. Then, the card module 8 of the IC card 1 is contained and hold in the plastic frame 2, and the obverse and reverse thereof are covered by the pair of the metal panel 6,7, and, electronic components etc.4 of the card module 8 are electrically protected, by those metal panels 6,7, from static electricity impressed from out side. In the next place, the pressing for fixation the lower metal panel 7 of the lower metal panel 7 into the frame 2 and the engaging for securing the upper metal panel 6 with the lower metal panel 7 will be explained. In the embodiment, on each longitudinal side edge portion of the upper metal panel 6, a bent portion 6a formed, by bending the panel material at about 90 degrees, to L-shape in cross sectional configuration is provided respectively, and, at a plurality of places (seven places in this embodiment) of longitudinal side edge portion of said bent portion 6a, a plurality of projections 6c (tongues) are formed by bending the side edge portion inwardly further at about 90 degrees. As understood well from FIG. 3, more preferably, those tongues 6c project inwardly respectively, so that they form generally triangles in plan view, from a basic edge portion 6b formed by bending the side edge portion of said bent portion 6a inwardly further at about 90 degrees. On the other hand, also regarding to the lower metal panel, on each longitudinal side edge portion thereof, a bent portion 7a formed, by bending the panel material at about 90 degrees, to L-shape in cross sectional configuration is provided respectively, and, at a plurality of places corresponding to the tongues 6c of the upper metal panel 6, generally rectangular projections 7c (projecting pieces) project upwardly from the bent portion 7a are provided.And, as understood well from FIG. 4, an generally triangle engaging opening 7h with which engages the tongue 6c of the upper metal panel 6 is formed in each projecting piece. In the lower metal panel 7, more preferably, also on the rear side edge portion, a bent portion 7a of L-shape in cross sectional configuration as same as said bent portion 7a and a plurality of projecting pieces 7c are formed, however, the above-mentioned engaging openings 7h are not provided in the projecting pieces 7c of this portion. Also, on longitudinal frame portions 2a along the longitudinal direction of the plastic frame 2, predetermined depth of concavities 2c are provided at a plurality of places corresponding to the projecting pieces 7c of the lower metal panel 7, and, as shown in detail in FIG. 5, in the bottom wall of each concavity 2c, a slit 2h through which a corresponding projecting piece 7c passes in a condition of being pressed in. The upper surface of a convexity 2d adjacent to each concavity 2c in the longitudinal frame portion 2a constitutes a supporting surface for the upper metal panel 6 in assembling the IC card 1. In this embodiment, the length of said each slit 2h is determined to be less than the corresponding projecting piece 7c by predetermined (very slight) length, and, by enforcing each projecting piece 7c to pass through each corresponding slit 2h by external force, each projecting piece 7c (therefore, the lower metal panel 7) is pressed for fixation to the frame 2 with a certain pressing force. Also, in this condition of being pressed in, the position of the engaging opening 7h and the depth of the concavity 2c are determined so that the engaging opening 7h formed in each projecting piece 7c is positioned upward than the bottom wall of each concavity 2c. It is not shown concretely in the figures, but, more preferably, regarding to transverse frame portions 2b of the frame 2, holes into which each corresponding projecting piece 7c is to be pressed in are provided. However, regarding to this portion, any concavity is not provided in the transverse frame its self, also, each hole does not open through upwardly, therefore, each projecting piece 7c is to be buried in the transverse frame portion 2b by pressing. After pressing for fixation the lower metal panel 7 into the plastic frame 2, as mentioned above, in engaging for securing the upper metal panel 6 with the lower metal panel 7, in the final procedure of assembling the IC card 1, as shown by an arrow of virtual lines in FIG. 1, a predetermined external force is applied on the upper metal panel 6. And, the upper metal panel is incurvated within the elasticity of the material thereof in such a manner as lifting up each longitudinal side edge portion against the middle area, in other words, as expanding the middle area downwardly, and by this, the distance between the tongues 6c of both the side edge portions is enlarged. And, in this incurvated condition, as shown in FIG. 6, each tongue 6c is to be engaged with the corresponding engaging opening 7h of the projecting piece 7c from out side of the projecting piece 7c of the lower metal panel 7, and thereafter, the external force applied on the upper metal panel 6 is to be released. Thus, each tongue 6c engages with the engaging opening 7h of the corresponding each projecting piece 7c, and, the direct contact between the upper and lower metal panels 6,7 is achieved. Furthermore, in this case, after releasing the external force applied on the upper metal panel 6, by the elastic force of the upper metal panel 6 itself, each tongue 6c is subject to a moment in the direction of lifting up the corresponding projecting piece 7c. By this, each tongue 6c does not merely touch by engaging with corresponding projecting piece, but also be connected firmly by a certain biassing force (elastic force of the whole upper metal panel 6).And, it is secured by the engagement without a shake. Then, a tapered part of each tongue 6c is combined with a tapered part of the engaging opening 7h in a corresponding projecting piece 7c, and they can slide mutually. By this, they can be engaged surely as scatters in mutual dimensions and shapes are being absorbed. As shown in FIG. 7, the engaging portion between them is contained in each concavity 2c formed in the longitudinal frame portion 2a of the frame 2. Also, as shown in FIG. 8, the reverse side of the upper metal panel 6 is supported by the upper surface of the convexity 2d adjacent to the concavity 2c in the longitudinal frame portion 2a. As shown in FIG. 7 and FIG. 8, in left and right longitudinal frame portion 2a of the plastic frame 2, a groove 2f for containing the bent portion 6a of the upper metal panel 6 and a groove 2g for containing the bent portion 7a of the lower metal panel 7 are provided in the longitudinal direction. As explained above, according to the embodiment of the invention, since the projecting piece 7c of the lower metal panel 7 is pressed into each slit 2h provided to the plastic frame 2, the lower metal panel 7 is fixed by pressing into the frame 2 by means of the pressing force. And, since corresponding tongue 6c of the upper metal panel 6 is engaged with each projecting piece 7c of the lower metal panel 7 respectively in a condition of being subject to elastic force of the metal panels, the upper metal panel 6 is secured by engaging to the lower metal panel 7 by means of the elastic force. In other words, both the metal panels 6,7 can be secured to the frame 2 without using adhesion. As the result, the adhesion itself and special equipments to be used in adhesive process are not required any more, and, the assembling process can be much simplified, by these, a reduction of the manufacturing cost of the IC card can be achieved. Also, in this case, since both the metal panels 6,7 are conducted electrically due to mutual engagements of their projections(tongues 6c and projecting pieces 7c), the durability against static electricity impressed from out side can be elevated still higher. That is to say, it comes to be possible to secure the obverse and reverse metal panels 6, 7 without using adhesion, and at a time, to conduct both the metal panels 6,7 electrically, accordingly, reduction of the manufacturing cost and improvement of the endurance against static electricity can be achieved at the same time. Furthermore, in this case, since the tongues 6c of the upper metal panel 6 covering the upper side(obverse side) of the IC card 1 are engaged with the corresponding projecting pieces 7c of the lower metal panel 7 covering the lower side(reverse side) of the IC card 1 from out side, the engaging portions between both the projections 6c,7c are covered by the upper metal panel 6, accordingly, they can not be observed easily from the obverse side. In other words, it is possible to improve the appearance of the obverse side which attracts people's attention. Also, in this case, since the engaging portion having tapered parts is provided respectively to each projection(tongue 6c, projecting piece 7c) of both the metal panels 6,7, when they engage with each other, they can slide mutually in the condition that the tapered parts thereof are combined, and, they can be engaged surely as scatters in mutual dimensions and shapes are being absorbed. Further, in this case, since on the side edge portions of each metal panel 6,7, bent portions 6a,7a formed along the side edge by bending a panel material at a predetermined angle (about 90 degrees) to L-shape in cross-sectional configuration are provided, it comes to be possible to raise the rigidity of each metal panel 6,7, in comparison with the case that they are designed to be merely flat plate. Furthermore in this case, since the concavities 2c which contain the engaging portion between the projections(tongues 6c, projecting pieces 7c) of both the metal panel 6,7 and the convexities 2d which can support the upper metal panel 6 in the engaging condition thereof, it is possible to engage each projection (tongue 6c, projecting piece 7c) of both the metal panels 6,7 mutually without any trouble, and to ensure effectively the supporting rigidity for the upper metal panel 6 in that engaging condition. Also, in this case, since in engaging for securing the upper metal panel 6 to the lower metal panel 7, each tongue 6c of the upper metal panel 6 is to be engaged respectively with a corresponding projecting piece 7c of the lower metal panel 7, by incurvating the upper metal panel 6 toward a predetermined direction within its elasticity, it is possible to act elastic force on the engaging portion between the projections (tongue 6c, projecting piece 7c) relatively easily and surely. In the next place, a second embodiment of the invention, illustrated in FIG. 9-FIG. 13, will be explained. In the explanation below, the same components as in the first embodiment are designated by same reference numerals, and duplicated descriptions are eliminated. In this embodiment, as shown in FIG. 9, in a bent portion 26a of L-shape in a cross-sectional configuration formed on each longitudinal side edge portion of an upper metal panel 26, a plurality of(for example 7 pieces in this embodiment) generally triangle tongues 26c similar to those in the first embodiment are formed. On the other hand, in bent portion 27a of L-shape in a cross sectional configuration formed on each longitudinal side edge portion of a lower metal panel 27, a plurality of projecting pieces 27c are provided at corresponding positions to the tongues 26c. In this embodiment, as shown in FIG. 10, tapered notches 27h which open toward the rear side are provided to those projecting pieces 27c respectively, in order to engage the tongues 26c of the upper metal panel 26. Also, in a longitudinal frame portions 22a of the plastic frame 22 (refer to FIG. 11), concavities, slits, convexities etc. which have the same functions as those in the first embodiment are provided, though they are not shown concretely in the figure. And, the lower metal panel 27 is fixed to the frame 22, by pressing each projecting piece 27c of the lower metal panel 27 into the slit 22h (refer to FIG. 12) of the frame 22, in the same manner as in the first embodiment. In this embodiment, as shown in FIG. 11, in the final step of assembling the upper metal panel 26, by sliding the upper metal panel 26 from the rear side toward the front side of an IC card body 21 (refer to an arrow in FIG. 11), in the condition of setting the upper metal panel 26 on the frame 22(refer to broken lines in FIG. 11), the tongues 26c of the upper metal panel 26 are engaged with the notches 27h in the corresponding projecting pieces 27c of the lower metal panel 27, as shown in FIG. 12. By this, the upper metal panel 26 is secured to the lower metal panel 27. In this case, the concavities formed in the longitudinal frame portions 22a of the frame 22 are designed to be so long in the longitudinal direction of the IC card 21 that the upper metal panel 26 can slide without any trouble. In this embodiment, as shown in FIG. 13, a stair 22s is formed in a upper face of a transverse frame portion 22b of the frame 22, and the rear end 26e of the upper metal panel 26 is at the position protruding by a predetermined(very slight) from a vertical wall of the stair 22s in the transverse frame portion 22b, and, by applying an external force toward the front side on the upper metal panel 26, the rear end 26e of the upper metal panel 26 is enforced to press into the stair 22s. Therefore, in this case, the upper metal panel 26 is incurvated in the longitudinal direction of the IC card 21. As the result, each tongue 26c of the upper metal panel 26 does not merely touch by engaging with each corresponding projecting piece 27c, but also be secured firmly by a certain biassing force (elastic force of the upper metal panel 26) acting in the longitudinal direction of the card. Then, since the tapered part of each tongue 26c can slide along the tapered part of the notch 27h of the corresponding projected piece 27c, they can engage surely as scatters in mutual dimensions and shapes are being absorbed. And, the dimensions and required accuracy of each portion are determined so that a predetermined biassing force is obtained in that engaged condition. Also, in this embodiment, the maximum slide length E (refer to FIG. 11) in sliding the upper metal panel 26 from rear side to front side is determined to be less than the width W(refer to FIG. 1) of the connector 5. By this, the front end portion of the upper metal panel 26 slides on the same plane (upper surface of the connector 5) before and after of the slide motion, and, it comes to be possible to ensure a smooth slide motion without scratches. As explained above, in this embodiment, the same advantages as those in the first embodiment are obtained basically, and especially, since the engagement between the projections (tongues 26c, projecting pieces 27c) of both the metal panels 36,37 are obtained by sliding the upper metal panel 26 along the upper surface of the frame 22, the assembling work of both the metal panels 26,27 can be performed relatively easily. In the next place, a third embodiment of the invention, illustrated in FIG. 14-FIG. 18, will be explained. As shown in FIG. 14, in this embodiment, on each longitudinal side edge portion of the upper metal panel 36, a bent portion 36a formed by bending the panel material at about 90 degrees to L-shape in cross sectional configuration is provided respectively, and, tongues 36c are formed at a plurality of places (seven places in this embodiment), by bending the longitudinal side edge portion of said bent portion 36a inwardly further at about 90 degrees. As understood well from FIG. 15, those tongues 36c are respectively projecting inwardly so that they form generally rectangles in plan view, from the side edge portion of said bent portion 36a. And, triangle engaging openings 36h are formed in those tongues 36c in order to engage the projecting pieces 37c of the lower metal panel 37. On the other hand, in a bent portion 37a of L-shape in a cross-sectional configuration formed on each longitudinal side edge portion of the lower metal panel 37, at a plurality of places corresponding to the tongues 36c of the upper metal panel 36, projecting pieces 37c which project upwardly from the bent portion 37a are provided. In this embodiment, as shown in detail in FIG. 16, the upper portion of the projecting piece 37c is formed to be waisted configuration, and, the neck portion 37d thereof can engage with the engaging opening 36h provided to the tongue 36c of the upper metal panel 36. In the lower metal panel 37, more preferably, a bent portion 37a of L-shape in cross sectional configuration as same as said bent portion 37a and a plurality of projecting pieces 37c are formed also on rear side edge portion, however, the above-mentioned waisted configuration are not provided in the projecting pieces 37c of this portion, and they are formed as merely rectangular configuration. Also, the plastic frame of the IC card according to this embodiment has the same constitution as that in the first embodiment, although it is not shown concretely in the figure. And, by pressing each projecting piece 37c of the lower metal panel 37 into the slit 2h of the frame 2(refer to FIG. 17, FIG. 18) in the same manner as in the first embodiment, the lower metal panel 37 is fixed to the frame 2. After pressing the lower metal panel 37 into the plastic frame 2 for fixation, in engaging the upper metal panel 36 for securing to the lower metal panel 37 in the final step of assembling the IC card 31, as shown by an arrow of virtual lines in FIG. 14, by applying a predetermined external force on the upper metal panel 36, the upper metal panel is incurvated within the elasticity of the material thereof, in such a manner as pressing down each longitudinal side edge portions against the middle area, in other words, as expanding the middle area upwardly. By this, the distance between the tongues 36c of both the side edge portions is narrowed.And, in this incurvated condition, as shown in FIG. 17, each projecting piece 37c of the lower metal panel 37 is to be engaged with the engaging opening 36h of the corresponding tongues 36c of the upper metal panel 36. Then, since the upper metal panel 36 is incurvated as mentioned above, the projecting pieces 37c of the lower metal panel 37 are inserted smoothly into the wide portions in the engaging openings 36h in the tongues 36c of the upper metal panel 36, the engaging work can be performed easily. And thereafter, the external force applied on the upper metal panel 36 is to be released. Thus, each projecting piece 37c of the lower metal panel 37 engages with the engaging opening 36h in the corresponding tongue 36c, and, the direct contact between the upper and lower metal panels 36, 37 is achieved. Furthermore, in this case, after releasing the external force acting on the upper metal panel 36, by the elastic force of the upper metal panel 36 itself, each tongue 36c is subject to a moment in the direction of lifting up the corresponding projecting piece 37c. By this, each tongue 36c does not merely touch by engaging with each corresponding projecting piece 37c, but also be connected firmly by a certain biassing force (elastic force of the upper metal panel 36). Then, a tapered portion of the engaging opening 36h of each tongue 36c is combined with a tapered part of the neck portion 37d of the corresponding projecting piece 37c, and they can slide mutually. By this, they can be engaged surely as scatters in mutual dimensions and shapes are being absorbed. As understood well from FIG. 18, the engaging portion between them is contained in each concavity 2c formed in the longitudinal frame portion 2a of the frame 2. Also, in this moment, the reverse side of the upper metal panel 36 is supported by the upper surface of each convexity 2d formed in the longitudinal frame portion 2a. As explained above, in this embodiment, the same advantages as those in the first embodiment is obtained basically, and especially, since each projecting piece 37c of the lower metal panel 37 is formed to be a waisted configuration having a neck portion 37d, and the tapered part of the engaging opening 36h provided to each tongue 36c of the upper metal panel 36 engages with the neck portion 37d, when they engage with each other, it is possible to obtain an engaged condition by acting the elastic force of the metal panels, after inserting each projecting piece 37c of the lower metal panel 37 into the wide area of the tapered part. And, it is possible to engage the upper metal panel 36 with the lower metal panel 37 for fixation without applying immoderate force on the upper metal panel 36. In the next place, the fourth embodiment of the invention, illustrated in FIG. 19-FIG. 22, will be explained. As shown in FIG. 19, in this embodiment, on each longitudinal side edge portion of the upper metal panel 46, a bent portion 46a formed by bending the panel material oblique-inwardly is provided. And, at a plurality of places (seven places in this embodiment), such generally triangle tongues 36c which project inwardly are formed in the same inclined plane as that bent portion 46a. In this case, as shown in detail in FIG. 20, since the bent portion 46a and the tongues 46c are designed to be in a same plane, it is not required to divide the bending work of the panel material into two steps, and working process can be simplified. On the other hand, regarding to a lower metal panel 47, a bent portion 47a formed to be L-shape in a cross-sectional configuration by bending the panel material at about 90 degrees is provided to each longitudinal side edge portion of the lower metal panel 37. That is to say, the bending angles of the upper metal panel 46 and the lower metal panel 47 are different from each other. And, on the side edge portion of the bent portion 47a of the lower metal panel 47, at a plurality of places corresponding to the tongues 46c of the upper metal panel 46, generally rectangular projecting pieces 47c which project upwardly from the bent portion 47a are provided. And, as understood well from FIG. 21, triangle shaped engaging openings 47h which engage the tongues 46c of the upper metal panel 46 are formed respectively in the projecting pieces 47c. In the lower metal panel 47, more preferably, a bent portion 47a of L-shape in cross sectional configuration as same as said bent portion 47a and a plurality of projected pieces 47c are formed also on rear side edge portion, however, the above-mentioned engaging openings are not provided in the projecting pieces 47c of this portion. Also, the plastic frame of the IC card according to this embodiment has the same constitution as that in the first embodiment, though it is not shown concretely in the figure. And, by pressing each projecting piece 47c of the lower metal panel 47 into the slit 2h of the frame 2 (refer to FIG. 21, FIG. 22) in the same manner as in the first embodiment, the lower metal panel 47 is fixed to the frame 2. After pressing the lower metal panel 47 for fixation to the plastic frame 2, as mentioned above, in engaging the upper metal panel 46 for securing to the lower metal panel 47 in the final step of assembling the IC card 41, as shown by an arrow of virtual lines in FIG. 19, by applying a predetermined external force on the upper metal panel 46, bend the upper metal panel is incurvated within the elasticity of the material thereof, in such a manner as lifting up each longitudinal side edge portions against the middle area, in other words, as expanding the middle area downwardly. By this, the distance between the tongues 36c of both the side edge portions is enlarged. And, in this incurvated condition, as shown in FIG. 21, each tongue 46c of the upper metal panel 46 is to be engaged with the engaging opening 47h of the corresponding projecting piece 47c of the lower metal panel 47. And thereafter, the external force applied on the upper metal panel 46 is to be released. Thus, each tongue 46c of the upper metal panel 46 engages with the engaging opening 47h of the corresponding each projected piece 47c of the lower metal panel 47, and, the direct contact between the upper and lower metal panels 46, 47 is achieved. Furthermore, in this case, after releasing the external force acting on the upper metal panel 46, by the elastic force of the upper metal panel 46 itself, each tongue 46c is subject to a moment in the direction of lifting up the corresponding projected piece 47c. By this, each tongue 46c does not merely touch by engaging with each corresponding projected piece 47c, but also be connected firmly by a certain biassing force (elastic force of the upper metal panel 46). Then, a tapered part of each tongue 46c is combined with a tapered part of the engaging opening 47h of the corresponding projecting piece 47c, and they can slide mutually. By this, they can be engaged surely as scatters in mutual dimensions and shapes are being absorbed. As understood well from FIG. 22, the engaging portion of them is contained in each concavity 2c formed in the longitudinal frame portion 2a of the frame 2. Also, in this moment, the reverse side of the upper metal panel 46 is supported by the upper surface of each convexity 2d formed in the longitudinal frame portion 2a. As explained above, in this embodiment, the same advantages as those in the first embodiment is obtained basically, and especially, since the bent portions 46a of the upper metal panels 46 are bent at a different angle from the bent portions 47a of the lower metal panel 47, and the projecting pieces 46c project additionally from the edge of the bent portions 46a in the same plane, the bent portions 46a and the projecting piece 46c are in the same plane, therefore, in bending the upper metal panel 46, it is not necessary to bend the panel material in divided two stages, and working process can be simplified. The invention is not limited within the foregoing embodiments, and, it is to be understood that the various kind of improvements and the alternation in design is possible in the scope of the invention. What is claimed is: 1. An IC card comprising an electrical circuit board in which at least one electronic component is incorporated, a connector to be connected to an end portion of the electrical circuit board, a frame which constitutes an outer frame of the IC card and a pair of metal panels which cover obverse and reverse sides of the IC card, whereina plurality of projections being able to engage with each other are provided on side edge portions of each metal panel, while, a plurality of slits into which the projections are to be pressed are provided to the frame, and the projections of said one metal panel are pressed into the slits, also, corresponding projections of the outer metal panel are engaged with the projections of said one metal panel respectively in a condition of being subject to elastic force of the metal panels. 2. An IC card according to claim 1, wherein said one metal panel covers the reverse side of the IC card and the other metal panel covers the obverse side of the IC card, and the projections of the other metal panel are engaged with the corresponding projections of said one metal panel from out side. 3. An IC card according to claim 1, wherein a notch opening in a direction along a plane of the IC card is provided to each projection of said one metal panel, and each projection of the other metal panel engages with the notch, by sliding the other metal panel along a corresponding surface of the frame. 4. An IC card according to claim 1, wherein an engaging portion having tapered parts is provided respectively to each projection of both the metal panels. 5. An IC card according to claim 1, wherein on the side edge portions of each metal panel, bent portions formed along the side edge by bending a panel material at a predetermined angle are provided, and the projections of each metal panel are formed so that they project additionally from an edge of the bent portion. 6. An IC card according to claim 1, wherein concavities which contain the engaging portion between the projections of both the metal panel and convexities which can support the other metal panel in an engaging condition thereof are provided. 7. An IC card according to claim 2, wherein an engaging portion having tapered parts is provided respectively to each projection of both the metal panels. 8. An IC card according to claim 2, wherein the side edge portions of each metal panel, bent portions formed along the side edge by bending a panel material at a predetermined angle are provided, and the projections of each metal panel are formed to project additionally from an edge of the bent portion. 9. An IC card according to claim 2, wherein concavities which contain the engaging portion between the projections of both the metal panel and convexities which can support the other metal panel in an engaging condition thereof are provided. 10. An IC card according to claim 3, wherein the notch opens toward a reverse side of a portion of the IC card at which the connector is positioned, and a maximum slide length of the other metal panel is determined to be less than a width of the connector. 11. An IC card according to claim 3, wherein an engaging portion having tapered parts is provided respectively to each projection of both the metal panels. 12. An IC card according to claim 3, wherein on the side edge portions of each metal panel, bent portions formed along the side edge by bending a panel material at a predetermined angle are provided, and the projections of each metal panel are formed so that they project additionally from an edge of the bent portion. 13. An IC card according to claim 3, wherein concavities which contain the engaging portion between the projections of both the metal panel and convexities which can support the other metal panel in an engaging condition thereof are provided. 14. An IC card according to claim 4, wherein each projection of said one metal panel is formed to be a waisted configuration having a neck portion and the tapered part of the engaging portion provided to each projection of the other metal panel engages with the neck portion. 15. An IC card according to claim 4, wherein on the side edge portions of each metal panel, bent portions formed along the side edge by bending a panel material at a predetermined angle are provided, and the projections of each metal panel are formed so that they project additionally from an edge of the bent portion. 16. An IC card according to claim 4, wherein concavities which contain the engaging portion between the projections of both the metal panel and convexities which can support the other metal panel in an engaging condition thereof are provided. 17. An IC card according to claim 5, wherein the bent portions of both the metal panels are bent by mutually different angles, and the projections of each metal panel project additionally from the edge of the bent portions in the same plane. 18. An IC card according to claim 5, wherein concavities which contain the engaging portion between the projections of both the metal panel and convexities which can support the other metal panel in an engaging condition thereof are provided.

1996-06-24

en

1999-11-30

US-12284293-A

Coextruded multilayer plastic container utilizing post consumer plastic ABSTRACT A coextruded multilayer plastic container utilizing post consumer plastic resin comprising an appearance enhancing thin outer layer of ethylene polymers, which enhances the appearance of the container, an intermediate layer comprising a fusion blend of post consumer resin with or without colorant and a third layer comprising a fusion blend of post consumer resin which may have mixed colors. In a modified and preferred form, a fourth inner layer of virgin ethylene polymer is provided. This invention relates to coextruded plastic containers and particularly to blown plastic containers made of post consumer resin. BACKGROUND AND SUMMARY OF THE INVENTION In the use of plastic materials for containers such as bottles, it has been found desirable to attempt to recycle and reuse the plastic which is commonly known as post consumer plastic (PCP) or post consumer resin (PCR). In attempts to make containers from such materials, it has been found that the properties have been adversely affected. Specifically when containers are made from recycled post consumer high density polyethylene homopolymers (HDPE) container scrap, it has been found that the containers have diminished physical properties. Such containers made of high density polyethylene homopolymers also have been used for packaging of certain types of liquid detergent products. The use of such containers to package liquid detergent products has been somewhat restricted, however, by reason of the fact that many types of liquid detergent products accelerate the tendency of the container to exhibit stress cracking. Stress cracking is evidenced by the appearance of hazy cracks in the container which are aesthetically unpleasing to the ultimate consumer. In extreme cases, stress cracking can lead to leakage of the contents from the container. Stress cracking can occur when the containers are for liquid products including liquid detergents and liquid hypochlorite bleaches. It has been suggested that such post consumer resin be utilized because large quantities of high density polyethylene post consumer resin are available due to the extensive use of high density polyethylene in large containers for milk and water. Post consumer resin from such containers contains contaminants of paper and other plastic resins, for example, from closures such that it has been generally thought that it can not be used to make satisfactory plastic containers. In copending application Ser. No. 07/842,839 filed Feb. 27, 1992, having a common assignee with the present application, there is disclosed a plastic container which is made from a fusion blend of a post consumer resin and ethylene polymers comprising post consumer resin of homopolymer high density polyethylene plastic and virgin high density polyethylene copolymer resin. The physical properties of the container including stress crack resistance are maintained as contrasted to the loss of such physical properties that have been heretofore resulted from the use of post consumer resins. In accordance with the aforementioned application, pellets of a homopolymer high density polyethylene resin from post consumer resin (PCR) and pellets of a virgin high density polyethylene copolymer were mixed and fusion blended. Containers were blow molded and subjected to testing for stress cracking, top load and drop impact. In copending application Ser. No. 07/842,838 filed Feb. 27, 1992, having a common assignee with the present application, there is disclosed a plastic container made from a fusion blend of a post consumer plastic and ethylene polymers and comprising post consumer resin of homopolymer high density polyethylene resin and a small amount of linear low density polyethylene resin. In another form, the container is made from a blend of post consumer homopolymer high density polyethylene resin, virgin high density polyethylene resin with a small amount of linear low density polyethylene resin. The physical properties of the container including stress cracks resistance are maintained as contrasted to the loss of such physical properties that have been heretofore resulted from the use of post consumer resins. Large quantities of plastic resin are used to make containers which have an attractive appearance provided by additives which function to provide gloss or attractive colors. Such additives are quite expensive. As far as the present inventors are aware, it has not heretofore been thought to have been possible to utilize post consumer resin to make plastic containers wherein the container has additives to enhance gloss, or color, which requires expensive colorants because of the gray colors that are inherent in the post consumer resin. Among the objectives of the present invention are to provide a plastic container which has an outer appearance layer; which not only utilizes post consumer plastic but also permits the use of post consumer resin having various colors therein; wherein plastic container is constructed and arranged such that the post consumer resin having multiple colors is obscured and results in a container that provides an attractive appearance; wherein a relatively dark, thick, post consumer resin layer comprises the major portion of the container is not visible; wherein the container can have a significant attractive appearance color; and wherein the container results in significant resin savings. In accordance with the invention, a coextruded multi-layer plastic container utilizing post consumer plastic resin comprising an appearance enhancing thin outer layer comprising a fusion blend of ethylene polymers and a colorant which enhances the appearance of the container, an intermediate layer comprising a fusion blend post consumer recycled resin with or without colorant and a third layer comprising post consumer resin which may have mixed colors. In a modified and preferred form, a fourth inner layer of virgin ethylene polymer is provided over the third inner layer. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a plastic container embodying the invention. FIG. 2 is a fragmentary sectional view on a greatly enlarged scale taken along the line 2--2 in FIG. 1 diagrammatically showing the cross section of the container. FIG. 3 is a fragmentary sectional view on a greatly enlarged scale diagrammatically showing the cross section of a modified form of container. FIG. 4 is a fragemetnary sectional view on a greatly enlarged scale diagrammatically showing the cross section of another modified form of container. DESCRIPTION Referring to FIG. 1, a multilayer hollow plastic container 10 embodying the invention is preferably made by coextruding a multilayer parison and then blow molding the container hving a body portion 11, a base portion 12, a shoulder portion 13 and a neck portion 14 having a finish 15. Referring to FIG. 2, in a preferred form, the container 10 comprises four layers; an outer thin appearance enhancing plastic layer A comprising a fusion blend of ethylene homopolymer polymers and an additive for enhancing the appearance; an adjacent thin plastic layer B which functions to mask the color of a third thicker plastic layer C one which comprises a fusion blend of post consumer resin which may have mixed colors. A fourth thin inner plastic layer D of virgin ethylene homopolymer is provided on the interior of the container which protects the contents of the container where needed. In the form shown in FIG. 3, the inner layer D is omitted. The plastic resin of the outer layer A may comprise a fusion blend of ethylene copolymers such as linear low density polyethylene, low density polyethylene, high density polyethylene, or mixtures thereof and an appearance enhancing additive. Typical additives for enhancing comprise pigments providing bright attractive colors; flakes for providing pearlescent effects, such as aluminum or calcium carbonate flakes; and fluorescent dyes or pigments which absorb light at one wave length and emit light of greater wave length as is well known; and polymers of selected molecular weights which provide a high gloss appearance. The thin plastic layer B may comprise a fusion blend of ethylene polymer, preferably virgin high density polyethylene or post consumer resin and an appearance enhancing additive which will mask the post consumer resin in the thick layer C. Post consumer resin contains primarily the plastic from high density polyethylene homopolymer containers used for packaging milk and colored plastic containers and possible polypropylene resin from syrup bottles, multi-layer ketchup bottles and caps. Such post consumer resin may have the properties set forth in the following Table I. TABLE I ______________________________________ PROPERTY SPECIFIED VALUE ______________________________________ Material Density .960 ± .02 natural Melt Flow - Melt Index 0.5 ± 0.3 dgm Fines <0.01% Moisture <0.05% Contamination Paper <0.01% Plastic-Dens. >1.0 gm/cc < 0.1% ______________________________________ The thin inner layer D, when used, comprises ethylene copolymers such as virgin high density polyethylene or linear low density polyethylene. In each form the major portion of the thickness of the wall of the container is in thick layer C of post consumer resin. The linear low-density ethylene polymer(s) of the invention have a density in a range of about 0.91 to about 0.93 gm/ml, preferably in a range of about 0.92 to about 0.93 gm/ml, and especially about 0.925 gm/ml. The linear, low-density ethylene polymers will have a melt index of less than about 2.0 and preferably less than about 1.0 gm/10 min. It is desirable for the melt index to be close to the melt index of the linear high-density ethylene polymer included in the blend. These polymers are ethylene copolymers having polymerized about 2-6 and preferably about 4-6 mol % of an alpha-monoolefin containing 3 to 12 carbon atoms with the balance of the monomer polymerized therein being ethylene. The linear low-density ethylene polymers employed in the present invention have long linear chains with controlled numbers of relatively short chain branches attached to the linear chain along its entire length. The low density polyethylene homopolymer comprises utilized in the outer layer has a melt index of at least 2 and preferably less than 1; and a density of not greater than 0.93 g/ml. The low density polyethylene comprises the outside high gloss layer. The low density polyethylene has melt index of at least 2 and preferably less than 1 and will have a density mzx of 0.93 g/ml. The virgin high density copolymer resin contains linear high-density ethylene polymer. The linear high-density ethylene copolymer included in the blends will have a density of at least about 0.94 gm/ml, a melt index of less than about 0.5 gm/10 min. and will have polymerized therein at least about 98 mol % ethylene with any comonomer polymerized therein being an alpha-monoolefin containing about 3 to 12 carbon atoms. Such linear high-density ethylene polymers are known and reported in the art and are commercially available from numerous commercial producers. Such linear high-density ethylene polymers are prepared by polymerizing ethylene, optionally in the presence of an alpha-monoolefin comonomer containing 4 to 12 carbon atoms in the presence of certain metallic catalysts such as chromium catalysts, e.g. CrO3 supported on silica-alumina supports, and the Ziegler-Natta catalysts, e.g. TiCl3 employed in conjunction with certain aluminum alkyl cocatalysts. The requisite density and melt index desired in the polymer are obtained by proper control of polymerization conditions including temperature, pressure, comonomer concentration, and the concentration of telegenating agents such as hydrogen. The preferred linear high-density ethylene polymers will have a density of at least about 0.94 gm/ml. The especially preferred polymers will have a density of at least about 0.95 gm/ml. Stress crack resistance is conventionally conducted with test methods as established by Technical Bulletin PBI 11-1978 of the Plastic Bottle Institute, Rev.1-1991 or ASTM D2561-70 (Reapproved 1989). Typical examples of thicknesses of side walls of a container embodying the invention are: ______________________________________ Four layer thin layer A 2-20 mils thin layer B 2-10 mils thick layer C 5-30 mils thin layer D 1-10 mils Three layer thin layer A 2-20 mils thin layer B 2-10 mils thick layer c 5-30 mils Three layer thin layer A 3-20 mils thick layer B 8-30 mils thin layer C 1-10 mils ______________________________________ Examples of specific compositions of the layers in containers are as follows: EXAMPLE I Thin layer A--glossy high density polyethylene and pearlescent additive Thin layer B--post consumer resin (milk) and TiO2 colorant Thick layer C--post consumer resin (mixed color) and regrind Thin layer D--virgin high density polyethylene and colorant EXAMPLE II Thin layer A--glossy high density polyethylene Thin layer B--post consumer resin (milk) and TiO2 colorant Thick layer C--post consumer resin (mixed color) and regrind Thin layer D--virgin high density polyethylene and colorant EXAMPLE III Thin layer A--glossy low density polyethylene Thin layer B--post consumer resin (milk) and T1 O2 colorant Thick layer C--post consumer resin (mixed color) and regrind Thin layer D--virgin high density polyethylene Metal fragments None Other (glass, stone) None EXAMPLE IV Thin layer A--virgin high density polyethylene, glossy high density polyethylene and linear low density polyethylene Thin layer B--post consumer resin (milk) T1 O2 colorant Thick layer C--adhesive layer --Post consumer resin and regrind Thin layer D--Nylon In the form shown in FIG. 4, the inner player layer D' is made of a solvent resistant material, such as nylon, to provide a construction whereby the container can be used for solvent products such as petroleum distillates. In this form, the third layer C' comprises post consumer recycled polyethylene resin, process trim and offware scrap. An adhesive layer (not shown) is provided between the layer B and layer C' and also between layer C' and layer D' for layer adhesion. This adhesive layer comprises a nylon/polyethylene adhesive. As shown in the drawings, the layer C, C' comprises the major portion of the thickness. It can thus be seen that there has been provided a coextruded multi-layer plastic container utilizing post consumer plastic resin comprising an appearance enhancing thin outer layer comprising a fusion blend of ethylene polymers and a colorant which enhances the appearance of the container, an intermediate layer comprising a fusion blend post consumer recycled resin with or without colorant and a third layer comprising post consumer resin which may have mixed colors. In a modified and preferred form, a fourth inner layer of virgin ethylene polymer is provided over the third inner layer. It can thus be seen that there has been provided a plastic container which has an outer appearance layer; which not only utilizes post consumer plastic but also permits the use of post consumer resin having various colors therein; wherein plastic container is constructed and arranged such that the post consumer resin having multiple colors is obscured and results in a container that provides an attractive appearance; wherein a relatively dark, thick, post consumer resin layer comprises the major portion of the container is not visible; wherein the container can have a significant attractive appearance color; and wherein the container results in significant resin savings. We claim: 1. A multilayer coextruded and blow molded hollow plastic container which has a side wall consisting essentially ofa thin outer plastic layer comprising a fusion blend of virgin plastic resin and an appearance enhancing additive, said appearance enhancing additive being selected from the group consisting of pigments providing bright attractive colors, flakes for providing pearlescent effects, fluorescent dyes of pigments which absorb light of one wave length and polymers of selected molecular weights which provide a high gloss appearance, or mixtures thereof, a thin intermediate opaque plastic layer comprising a fusion blend of post consumer resin with colorants heat bonded to the outer layer during coextrusion without adhesives, a relatively thick inner plastic layer having a thickness greater than the thickness of the outer plastic layer and the intermediate opaque plastic layer comprising post consumer resin heat bonded to the intermediate layer during coextrusion without adhesives, said post consumer resin comprising the major portion by weight of the container, and said thin intermediate plastic layer masking the post consumer resin in said relatively thick inner plastic layer. 2. The plastic container set forth in claim 1 wherein said thin outer plastic layer comprises ethylene polymers selected from the group consisting of linear low density polyethylene, low density polyethylene, high density polyethylene, or mixtures thereof. 3. The plastic container set forth in claim 2 whereto said thin intermediate plastic layer comprises a fusion blend of post consumer resin primarily the plastic from high density polyethylene homopolymer containers used for packaging milk and colorant. 4. The plastic container set forth in claim 3 wherein said thick inner plastic layer comprises a fusion blend of post consumer resin including post consumer resin from colored plastic containers and regrind. 5. The plastic container set forth in claim 1 wherein said thin intermediate plastic layer comprises a fusion blend of post consumer resin primarily the plastic from high density polyethylene homopolymer containers used for packaging milk and colorant. 6. The plastic container set forth in claim 5 wherein said thick inner plastic layer comprises said post consumer resin including post consumer resin from colored plastic containers and regrind. 7. The plastic container set forth in any one of claims 2, 3-6 including a coextruded thin layer of plastic resin overlying said inner layer. 8. The plastic container set forth in claim 7 wherein said coextruded thin layer overlying said inner layer comprises virgin high density copolymer resin overlying the inner layer and heat bonded to the inner layer during coextrusion without adhesives. 9. The container set forth in claim 7 wherein said coextruded thin inner layer overlying said inner layer comprises solvent resistant plastic resin overlying the inner layer and bonded thereto by a coextruded layer. 10. The container set forth in claim 9 wherein said solvent resistant plastic resin comprises nylon including a coextruded adhesive layer between the intermediate opaque layer and the inner layer of post consumer resin and a coextruded adhesive layer between the inner layer of post consumer resin and said further inner layer of solvent resistant plastic, each said adhesive layer comprising a nylon/polyethylene adhesive. 11. The plastic container set forth in claim 7 wherein said thin layer overlying said thin layer comprises virgin high density polyethylene. 12. The container set forth in claim 1 wherein said plastic layers have thicknesses ranging as follows: ______________________________________ thin outer layer 2-20 mils thin intermediate layer 2-10 mils thick layer 5-30 mils. ______________________________________ 13. The container set forth in claim 7 wherein said layers have thicknesses ranging as follows: ______________________________________ thin outer layer 2-20 mils thin intermediate layer 2-10 mils thick layer 5-30 mils thin inner layer 1-10 mils. ______________________________________ 14. A method of forming a multilayer coextruded plastic container comprisingcoextruding a multilayer parison consisting essentially a thin outer plastic layer comprising a fusion blend of virgin plastic resin and an appearance enhancing additive, a thin intermediate opaque plastic layer comprising a fusion blend of a post consumer resin with colorants heat bonded to the outer layer during coextrusion without adhesives, and a relatively thick inner layer having a thickness greater than the thickness of the outer plastic layer and the intermediate opaque plastic layer comprising post consumer resin heat bonded to the intermediate layer during coextrusion without adhesives, said intermediate layer masking the post consumer resin, said appearance enhancing additive being selected from the group consisting of pigments providing bright attractive colors, flakes for providing pearlescent effects, fluorescent dyes of pigments which absorb light of one wave length and polymers of selected molecular weights which provide a high gloss appearance, or mixtures thereof, said post consumer resin comprising the major portion by weight of the container, and blow molding the multilayer parison to form a multilayer container wherein the thin intermediate plastic layer masks the post consumer resin in said relatively thick inner plastic layer. 15. The method set forth in claim 14 wherein said thin outer plastic layer comprises ethylene polymers selected from the group consisting of linear low density polyethylene, low density polyethylene, high density polyethylene, or mixtures thereof. 16. The method set forth in claim 15 wherein said intermediate plastic layer comprises a fusion blend of post consumer resin primarily from high density polyethylene homopolymer containers used for packaging milk and colorant. 17. The method set forth in claim 16 wherein said thick inner plastic layer comprises said post consumer resin including post consumer resin from colored plastic containers and regrind. 18. The method set forth in claim 15 wherein said intermediate plastic layer comprises a fusion blend of post consumer resin primarily from high density polyethylene homopolymer containers used for packaging milk and colorant. 19. The method set forth in claim 18 wherein said thick inner plastic layer comprises consumer resin including post consumer resin from colored plastic containers and regrind. 20. The method set forth in any one of claim 16, 16-19 including coextruding a thin layer of plastic resin overlying said inner layer. 21. The method set forth in claim 20 wherein said coextruded thin layer overlying said inner layer comprises virgin high density copolymer resin overlying the inner layer and heat bonded to the inner layer during coextrusion without adhesives. 22. The method set forth in claim 20 wherein said coextruded thin inner layer comprises solvent resistant plastic resin overlying the inner layer and bonded thereto by a coextruded layer. 23. The method set forth in claim 22 wherein said solvent resistant plastic resin comprises nylon including coextruding an adhesive layer between the intermediate opaque layer and the inner layer of post consumer resin and coextruding an adhesive layer between the inner layer of post consumer resin and said further inner layer of solvent resistant plastic, each said adhesive layer comprising a nylon/polyethylene adhesive. 24. The method set forth in claim 20 wherein said thin layer comprises virgin high density polyethylene. 25. The method set forth in claim 14 wherein said layers have thicknesses ranging as follows: ______________________________________ thin outer layer 2-20 mils thin intermediate layer 2-10 mils thick layer 5-30 mils. ______________________________________ 26. The method set forth in claim 20 wherein said layers have thicknesses ranging as follows: ______________________________________ thin outer layer 2-20 mils thin intermediate layer 2-10 mils thick layer 5-30 mils thin inner layer 1-10 mils. ______________________________________

1993-09-16

en

1998-01-27

US-47714090-A

Current amplifier circuit ABSTRACT An amplifier circuit (10) is provided which comprises a first transistor (12) and a second transistor (14). A current buffer circuit (16) is coupled to the basis of the transistors (12, 14) to provide base drive current. A voltage proportional to absolute temperature, V PTAT , is applied between the emitters of the transistors (12,14). An input current is received by the transistor (12) and an output current is generated by the transistor (14). The output current I out is amplified with respect to the input current I in by a gain factor which is substantially independent of temperature considerations. Circuitry is provided for altering the value of the voltage proportional to the absolute temperature, V PTAT , such that the gain of the amplifier circuit (10) is programmable. This application is a continuation of application Ser. No. 331,936, filed Mar. 31, 1989, now abandoned. TECHNICAL FIELD OF THE INVENTION This invention relates in general to the field of integrated electronic devices. More particularly, the present invention relates to a method and apparatus for providing substantially constant gain in a current amplifier circuit with respect to ambient temperature variations. BACKGROUND OF THE INVENTION Most integrated electronic devices exhibit changes in their performance characteristics as the temperature of the environment in which they are operating changes. This temperature dependence is due to the fact that most of the electronic components comprising these devices are themselves temperature dependent. In the case of an amplifier circuit, the gain of the amplifier can vary significantly because of changes in the ambient temperature. If the amplifier is a component of a larger integrated electronic device, the designer of the device must allow for these variations in performance due to temperature. This creates significant circuit design problems if an integrated device is to be used in an environment with widely varying temperatures. Simple circuits commonly used as amplifier stages are very susceptible to temperature changes. For example, a Darlington connection of two transistors can experience 100% change in the gain of the amplification stage over the normal working temperature range of the device. More complicated circuits may include compensation for this wide temperature dependence, but sacrifice the simplicity of the Darlington pair. Accordingly, a need has arisen for an amplifier circuit which has relatively few components, but can maintain a substantially constant gain over a wide temperature range. SUMMARY OF THE INVENTION In accordance with the present invention, an amplifier circuit is provided which substantially eliminates or reduces disadvantages and problems associated with prior amplifier circuits. A circuit is provided which provides a current gain which is substantially temperature independent. More specifically, the present invention provides for the use of two transistors and a current buffer circuit used to provide base drive current to the two transistors which are coupled in a mirror configuration. A voltage proportional to absolute temperature is applied between the emitters of the transistors. Because of the transfer characteristics of the transistors in the amplifier circuit, the temperature dependent devices compensate for one another and the resultant current gain is substantially temperature independent. According to another aspect of the present invention, a current proportional to temperature is driven through a resistive element coupled between the emitters of the transistors. The resistive element comprises a series connection of a plurality of resistors. Circuitry is provided such that selected resistors within the resistive element may be shorted out in order to alter the overall resistance of the resistive element. In this manner, the voltage between the emitters of the transistors may be programmed and thus the amplifier may be programmed to have any one of a number of predetermined current gains all of which will be substantially temperature independent. An important technical advantage of the present invention is that it provides for a substantially constant gain with respect to temperature variations, but uses a relatively small number of components. Through the use of the teachings of the present invention, an amplifier circuit may be built which has a programmable current gain which will vary by only a few percentage points over the normal operating range of temperature for most integrated electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present invention may be acquired by referring to the Detailed Description and claims when considered in connection with the accompanying drawings in which like reference numbers indicate like features, wherein: FIG. 1 is a schematic diagram of an amplifier circuit constructed in accordance to the present invention; and FIG. 2 is a schematic diagram of one embodiment of the present invention illustrating the programmable capability of the present invention and one method of providing the current proportional to temperature used in the present invention. FIG. 3 is a modification of FIGS. 1 and 2. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 illustrates a schematic diagram of an amplifier circuit, indicated generally at 10, constructed according to the teaching of the present invention. Circuit 10 comprises a first transistor 12 and a second transistor 14. First transistor 12 has its base coupled to the base of second transistor 14. Transistors 12 and 14 are constructed such that they exhibit identical transfer characteristics with the exception that transistor 14 is sized to be N times larger than transistor 12 where N is any predetermined factor. This sizing may be accomplished, for example, by forming transistor 14 to have N times the number of emitters as transistor 12. Transistors 12 and 14 are shown to be npn type bipolar junction transistors. It should be understood that the teachings of the present invention are equally applicable using pnp transistors. An input current Iin is shown in FIG. 1 to be flowing in the collector of transistor 12. An output current Iout is shown flowing in the collector of transistor 14. A current buffer 16 is shown coupled between the collector of transistor 12 and the bases of transistors 12 and 14. Current buffer 16 operates to provide base drive current to transistors 12 and 14. One embodiment of current buffer 16 is shown in FIG. 1 to comprise a transistor 18 with its base coupled to the collector of transistor 12 and its emitter coupled to the bases of transistors 12 and 14. The collector of transistor 18 is coupled to a VCC voltage supply. Transistor 18 is illustrative of only one possible method of providing the base current drive required of current buffer 16. Alternate embodiments of current buffer 16 could include a Darlington configuration of two transistors as shown in FIG. 3. It should be understood that still other embodiments of current buffer 16 are possible and these other embodiments are intended to be included within the scope of the present invention. A current labeled (IPTAT -Iin) is shown being input into circuit 10 at the emitter of transistor 12. This current when joined with the input current Iin forms the current labelled IPTAT shown in FIG. 1 to be flowing through a resistor 20. The current IPTAT flowing through resistor 20 creates a voltage labeled VPTAT. The current IPTAT and the voltage VPTAT are both proportional to absolute temperature in degrees Kelvin. The current IPTAT is created using circuitry known in the art such that its magnitude is proportional to the junction temperature of the device. As will be discussed herein, the fact that the magnitude of the current IPTAT changes proportionately to the ambient temperature directly results in the amplifier circuit 10 exhibiting a substantially constant gain when subjected to even dramatic temperature changes. The current gain of amplifier circuit 10 is defined as the ratio of output current Iout to the input current Iin. The base to emitter voltages for transistor 12 and transistor 14 have been labelled in FIG. 1 as VBE1 and VBE2 respectively. The operation of the amplifier circuit 10 may be best understood by an examination of the equations associated with its components. By summing the voltages around the lower loop of circuit 10, the following equation may be derived: V.sub.PTAT +V.sub.BE1 =V.sub.BE2 This equation may be algebraically rearranged to give an equation for VPTAT in terms of the VBE voltages of the transistors 12 and 14 as follows: V.sub.PTAT =V.sub.BE2 -V.sub.BE1 VBE2 and VBE1 may be written in terms of the input and output currents Iin and Iout as follows: ##EQU1## where k is Boltzman's constant, T is the absolute junction temperature in degrees Kelvin, q is the unit charge of an electron, N is the ratio of the size of transistor 14 to transistor 12 discussed previously, and c is a constant incorporating the transfer characteristics of transistors 12 and 14. By substituting equations (3) and (4) into equation (2), the following expression for VPTAT may be derived: ##EQU2## Assuming that VPTAT is IPTAT times the value R of the resistor 20, then an equation for Iout may be derived as follows for equation (5): ##EQU3## Using a circuit which will be described in conjunction with the description of FIG. 2, the current IPTAT can be generated with the following characteristics: PG,11 ##EQU4## where m is a scaling constant, Rs is a value of a resistor used to generate IPTAT, and λ is a constant current density ratio. By substituting the equation (7) for IPTAT into equation (6), an expression for the gain of the circuit 10 may be derived as follows: ##EQU5## The equation (8) derived for the gain β of circuit 10 helps to illustrate important technical advantages of the present invention. The gain β is dependent on the current density ratio λ, the sizing ratio N, the scaling constant m and the ratio of the resistances R to Rs. The resistors R and Rs may be constructed in such a manner that they exhibit identical temperature dependence. Thus, any temperature dependence of resistors R and Rs cancels and their ratio remains a constant term. The gain β of circuit 10 is therefore a constant, as it does not contain any terms which are dependent on temperature. Further, the gain β is proportional to the exponential of the ratio of two resistor values. For example, by using a series connection of a plurality of resistors, and circuitry for shorting out selected resistors in the series connection, the value of the resistance ratio can be selectively changed. In addition, other methods of programming the magnitude of the voltage between the emitters could also be used as long as the magnitude of the voltage changes proportionately to the absolute temperature of the device. Circuit 10 is thus adaptable to become an amplifier with a programmable current gain which, at any selected value for the gain β, is substantially independent of the ambient temperature of the device. FIG. 2 is a schematic diagram of one possible embodiment of the present invention which illustrates one method by which the current proportional to temperature IPTAT might be generated. Additionally, FIG. 2 illustrates one method in which the gain of the amplification stage might be programmed. An amplifier circuit indicated generally at 30 in FIG. 2 encompasses the aforementioned features. Circuit 30 may be conveniently divided into four general circuits. An amplification circuit 32 constitutes approximately the same structure that was illustrated in FIG. 1. A current source 34 is used to generate the current proportional to absolute temperature, IPTAT. A current mirror 36 is used to supply current to a current subtractor 38. Current subtractor 38 functions to subtract a certain amount of current from the current proportional to absolute temperature, IPTAT, such that when the input current, Iin, and the current proportional to absolute temperature are summed within the amplifier circuit 32, the voltage generated will be solely proportional to absolute temperature with no dependence on fluctuations in the input current, Iin. The current source 34 receives an initial current, Ii, through a terminal 42. The initial current Ii enters the current source 34 through the collector of a transistor 44. The collector of transistor 44 is also coupled to the base of transistor 44 and to the base of a transistor 46. The emitter of transistor 44 is coupled to the base of a transistor 50, and to the collector of a transistor 48. The emitter of transistor 46 is coupled to the base of transistor 48 and to the collector of transistor 50. Transistor 50 is sized to be four times the size of transistor 46 or to have four times the emitters of transistor 46. The emitters of transistor 50 are coupled through a resistor 52 which is labeled Rs to the emitter of transistor 48 and to a terminal 54. The resistor 52 has a value Rs which is the same value which appeared in equations (7) and (8) for IPTAT which were previously discussed. The current mirror 36 comprises a transistor 56 and a transistor 58, which have their bases coupled together. The emitter of transistor 56 are also coupled to the emitter of transistor 58 and to a terminal 59. The bases of transistor 58 and transistor 56 are coupled to the collector of transistor 58 and to the emitter of a transistor 60. The collector of transistor 56 is coupled to the base of transistor 60 and to the collector of transistor 46 in current source 34. The IPTAT current is generated in the collector of transistor 46 and through the operation of current mirror 36 is generated in the collector of transistor 58. The subtractor circuit 38 comprises a transistor 62 which has its emitter coupled to the collector of transistor 58 and the emitter of transistor 60. The transistor 62 has its base coupled to one of its collectors. The remaining collector of transistor 62 is coupled to the emitter of transistor 48, to the resistor 52 and to the terminal 54. Current subtractor 38 operates to pull two times the input current Iin from the collector of transistor 58. This results in the current flowing in the collector of transistor 60 differing from the magnitude of the current IPTAT by two times the input current Iin as labeled in FIG. 2. The base and the collector of transistor 62 are coupled to the collector of a transistor 64. Transistor 64 is sized the same as transistor 72, and is thus labeled 2X. Transistor 64 has two emitters which are coupled to the collector of transistor 60. The collector of transistor 64 furnishes a replicated current, Iin, to the current subtractor circuit 38. Thus, the current entering the amplifier circuit 32 differs from the magnitude of the current IPTAT by the magnitude of the input current Iin. A terminal 66 is also coupled to the emitters of transistor 64. The amplifier circuit 32 comprises a terminal 68 through which the input current Iin is input into the amplifier circuit 32. The terminal 68 is coupled to the base of a transistor 70 and to the collector of a transistor 72. The collector of transistor 70 is coupled to a terminal 74 and the emitter of transistor 70 is coupled to the base of transistor 72. The base of transistor 72 is coupled to the base of a transistor 76 and the base of transistor 64. The collector of transistor 76 is coupled to a terminal 78. The output current Iout is generated in either the collector or the emitters of transistor 76. The emitters of transistor 76 are coupled to a terminal 80. Depending upon the configuration of the circuit 30, the load for the amplifier circuit 32 might be positioned at either terminal 78 or 80. A resistor 82 is coupled between the base and the emitters of transistor 76. Resistor 82 provides a conduction path by which transistor 76 may be shut off. Transistor 76 is shown to be sized at ten times transistor 48. The ratio of the size of transistor 76 to the size of transistor 72 is equal to the N term in the equations discussed earlier with reference to FIG. 1. In the case of circuit 30, N would equal five. The emitters of transistor 72 and transistor 64 are coupled to a series connection of resistors through which the current IPTAT flows to create the voltage VPTAT This series connection is shown in FIG. 2 as comprising resistors 84, 86 and 88. A terminal 90 is shown coupled to a point between resistors 84 and 86, and a terminal 92 is shown coupled to a point between resistors 86 and 88. As discussed previously, the gain of the amplification stage 32 is dependent upon the ratio of the resistance used to generate the voltage VPTAT to the resistance Rs used to generate the current IPTAT. Thus, by changing the value of the resistance within the amplification circuit 32, the gain of the amplification circuit 32 may be programmed to any desired value. This programming may be accomplished by shorting out selected resistors within the series connection shown in FIG. 2. For example, terminal 90 could be connected to terminal 92 to short out resistor 86 and reduce the overall resistance used to generate the VPTAT voltage. It should be understood that resistors 84, 86 and 88 are presented solely for the purposes of teaching the present invention. Any number of resistors and programming terminals might be included in a particular embodiment of the present invention to allow for greater flexibility in programming the gain of an amplifier stage. Further, programmability is not limited to the value of the resistance in the amplification stage 32. The value of the resistance Rs in the current source 34 is also capable of being programmed in a similar manner. These and other methods of programming the gain of an amplification stage constructed according to the present invention are intended to be included within the scope of the present invention. Other modifications are possible to circuit 30 without departing from the scope of the present invention. For example, as discussed previously, a variety of current buffer devices may be used within an amplification circuit 32 in place of transistor 70 to provide base drive current to the transistors 72 and 76. For example, a pair of transistors configured in a Darlington fashion as shown in FIG. 3 would supply the base drive current and provide greater input resistance than the single transistor 70. In addition, there are a variety of methods of creating the voltage proportional to temperature, VPTAT, or the current proportional to temperature, IPTAT. The presentation of the specific embodiment illustrated in FIG. 2 is solely for purposes of teaching important technical advantages of the present invention and should not be construed to limit the scope of the present invention. For example, the NPN transistors could be changed to PNP transistors with appropriate changes in the circuit as is well known in the art. In summary, an amplification circuit is provided which provides for a substantially constant gain over a wide range of ambient temperature conditions. According to the teaching of the present invention, a method is provided by which the gain of the amplification circuit is programmable to any one of a number of selected values. Any of the selected values of the gain is then substantially independent of ambient temperature variations. Although the present invention 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 scope of the invention as defined by the appended claims. What is claimed is: 1. An amplifier circuit, comprising:(a) a first transistor comprising a base, an emitter and a collector; (b) a second transistor sized N times larger than said first transistor to determined the gain of said amplifier, where N is any predetermined factor, comprising a base, a collector and an emitter, said bases of said first and second transistors being coupled together; (c) a current buffer circuit coupled to said bases of said first and second transistors and operable to supply base drive current to said first and second transistors; and (d) circuitry for applying a voltage proportional to absolute temperature between said emitters of said first and second transistors. 2. The circuit of claim 1 wherein said current buffer circuit comprises:a third transistor comprising a base, an emitter and a collector, said base of said third transistor coupled to said collector of said first transistor, said emitter of said third transistor coupled to said bases of said first and second transistors and operable to supply said base drive current, said collector of said third transistor coupled to a predetermined voltage level. 3. The circuit of claim 1 wherein said current buffer circuit comprises third and fourth transistors each comprising a base, a collector and an emitter, said base of said third transistor coupled to said collector of said first transistor, said emitter of said third transistor coupled to said base of said fourth transistor, said collector of said third transistor coupled to said collector of said fourth transistor and a predetermined voltage level, said emitter of said fourth transistor coupled to said bases of said first and second transistors and operable to supply said base drive current. 4. The circuit of claim 1 wherein said circuitry for applying a voltage proportional to absolute temperature comprises:resistive circuitry coupled between said emitters of said first and second transistors; and circuitry for supplying a current proportional to absolute temperature coupled to said emitter of said first transistor and said resistive circuitry to cause current to flow through said resistive circuitry and create said voltage proportional to absolute temperature. 5. The circuit of claim 4 wherein the resistance of said resistive circuitry is programmable. 6. The circuit of claim 5 wherein said resistive circuitry comprises:a plurality of resistors coupled in series; and circuitry for shorting selected resistors of said plurality, the gain of the amplifier circuit responsive to said resistive circuitry such that the gain of the amplifier circuit is also programmable. 7. The circuit of claim 4 wherein said circuitry for supplying a current proportional to absolute temperature comprises a resistor, the value of said current proportional to temperature being inversely porportional to the value of said resistor such that the gain of the amplifier is proportional to the ratio of the value of the resistance of said resistive circuitry to the value of the resistance of said resistor. 8. The circuit of claim 1 and further comprising:programming circuitry for programming the gain of the amplifier circuit, said programming circuitry operable to change said voltage proportional to absolute temperature, the gain of the amplifier circuit responsive to said voltage proportional to absolute temperature. 9. The circuit of claim 1 wherein said second transistor is formed such that its size is proportionately larger than the first transistor, the gain of the amplifier being proportional to the ratio of the size of the second transistor to the size of the first transistor. 10. The circuit of claim 1 wherein said transistor comprise npn bipolar junction transistors. 11. The circuit of claim 1 wherein said transistors comprise pnp bipolar junction transistors. 12. An amplifier circuit having a programmable gain, comprising:(a) a first transistor comprising a base, a collector and an emitter, said first transistor operable to receive an input current input into the amplifier circuit; (b) a second transistor comprising a base, a collector and an emitter, said bases of said first and second transistors coupled together, said second transistor sized relative to said first transistor to have a predetermined greater size and operable to generate an output current for the amplifier circuit; (c) a third transistor comprising a base, a collector and an emitter, said emitter of said third transistor coupled to said bases of said first and second transistors, said base of said third transistor coupled to said collector of said first transistor, said third transistor operable to supply base drive current to said first and second transistors; (d) programmable resistive element having a plurality of predetermined resistance levels coupled between said emitters of said first and second transistors; and (e) circuitry for supplying a current proportional to absolute temperate to create a voltage between said emitters of said first and second transistors across said programmable resistive element. 13. The circuit of claim 12 wherein said transistors comprise npn bipolar junction transistors. 14. The circuit of claim 12 wherein said transistors comprise pnp bipolar junction transistors. 15. An amplifier circuit having a programmable gain, comprising:(a) a first transistor comprising a base, a collector and an emitter, said first transistor operable to receive an input current input into the amplifier circuit; (b) a second transistor comprising a base, a collector and an emitter, said bases of said first and second transistors coupled together, said second transistor sized proportionately to said first transistor and operable to generate an output current for the amplifier circuit; (c) a third transistor comprising a base, a collector and an emitter, said emitter of said third transistor coupled to said bases of said first and second transistors, said base of said third transistor coupled to said collector of said first transistor, said third transistor operable to supply base drive current to said first and second transistors; (d) a programmable resistive element having a plurality of predetermined resistance levels coupled between said emitters of said first and second transistors; and (e) circuitry for supplying a current proportional to absolute temperature to create a voltage between said emitters of said first and second transistors across said programmable resistive element; (f) said circuitry to supply a current comprising a resistor, said output current amplified relative to said input current by a gain factor, said gain factor being substantially constant with respect to absolute temperature changes and proportional to the ratio of the size of said second transistor to said first transistor and proportional to the ratio of the value of the resistance of said resistive element to the value of the resistance of said resistor. 16. An amplifier circuit having a programmable gain, comprising:(a) a first transistor comprising a base, collector and an emitter, said first transistor operable to receive an input current input into the amplifier circuit; (b) a second transistor comprising a base, a collector and an emitter, said bases of said first and second transistors coupled together, said second transistor sized proportionately to said first transistor and operable to generate an output current for the amplifier circuit; (c) a third transistor comprising a base, a collector and an emitter, said emitter of said third transistor coupled to said bases of said first and second transistor, said base of said third transistor coupled to said collector of said first transistor, said third transistor operable to supply base drive current to said first and second transistors; (d) a programmable resistive element having a plurality of predetermined resistance levels coupled between said emitters of said first and second transistors; and (e) circuitry for supplying a current proportional to absolute temperature to create a voltage between said emitters of said first and second transistors across said programmable resistive element; (f) wherein said programmable resistive element comprises: a plurality of resistors of predetermined values coupled in series; and circuitry for shorting out selected resistors of said plurality in order to program the overall resistance value of said resistive element. 17. A method for amplifying a current signal comprising the steps of:(a) supplying an input current to a collector of a first transistor; (b) generating an output current through the collector of a second transistor responsive to said input current; (c) supplying a voltage proportional to absolute temperature between an emitter of the first transistor and an emitter of the second transistor; and (d) supplying base drive current to the bases of the first and second transistors; (e) wherein the resistive element comprises a plurality of resistors coupled in series, the method further comprising the step of: (f) shorting out selected resistors in the resistive element in order to adjust the voltage proportional to temperature, the output current substantially proportional to the input current by a gain factor, the gain factor responsive to the level of the voltage proportional to absolute temperature. 18. The method for constructing a current amplifier circuit comprising the steps of:(a) forming a first transistor comprising a base, an emitter and a collector; (b) forming a second transistor comprising a base, a collector and an emitter, said second transistor sized relative to said first transistor to have a predetermined greater size, said bases of said first and second transistors being coupled together; (c) forming a current buffer circuit coupled to said bases of said first and second transistors and operable to supply base drive current to said first and second transistors; and (d) forming circuitry for applying a voltage proportional to absolute temperature between said emitters of said first and second transistors. 19. The method of claim 18 wherein said step of forming a current buffer circuit comprises the step of:forming a third transistor comprising a base, an emitter and a collector, the base of the third transistor coupled to the collector of the first transistor, the emitter of the third transistor coupled to the bases of the first and second transistors and operable to supply the base drive current, the collector of the third transistor coupled to a predetermined voltage level. 20. The method of claim 18 wherein said step of forming a current buffer circuit comprises the step of:forming third and fourth transistors each comprising a base, a collector and an emitter, the base of the third transistor coupled to the collector of the first transistor, the emitter of the third transistor coupled to the base of the fourth transistor, the collector of the third transistor coupled to the collector of the fourth transistor and a predetermined voltage level, the emitter of the fourth transistor coupled to the bases of the first and second transistors and operable to supply the base drive current. 21. The method of claim 18 wherein said step of forming circuitry for applying a voltage proportional to absolute temperature comprises the steps of:forming resistive circuitry coupled between said emitter of said first and second transistors; and forming circuitry for supplying a current proportional to absolute temperature coupled to said emitter of said first transistor and said resistive circuitry to cause current to flow through said resistive circuitry, such that the current flowing through said resistive circuitry creates said voltage proportional to absolute temperature. 22. The method for constructing a current amplifier circuit comprising the steps of:(a) forming a first transistor comprising a base, an emitter and a collector; (b) forming a second transistor comprising a base, a collector and an emitter, said bases of said first and second transistors being coupled together; (c) forming a current buffer circuit coupled to said bases of said first and second transistors and operable to supply base drive current to said first and second transistors; and (d) forming circuitry for applying a voltage proportional to absolute temperature between said emitters of said first and second transistors. (e) wherein said step of forming circuitry for applying a voltage porportional to absolute temperature comprises the steps of: (f) forming resistive circuitry coupled between said emitters of said first and second transistors; and (g) forming circuitry for supplying a current proportional to absolute temperature coupled to said emitter of said first transistor and said resistive circuitry to cause current to flow through said resistive circuitry, such that the current flowing through the resistive circuitry creates said voltage proportional to absolute temperature; (h) wherein said step of forming resistive circuitry comprises the steps of: (i) forming a plurality of resistors coupled in series; and forming circuitry for shorting selected resistors of the plurality, the gain of the amplifier circuit responsive to the resistive circuitry such that the gain of the amplifier circuit is also programmable. 23. The method for constructing a current amplifier circuit comprising the steps of:(a) forming a first transistor comprising a base, an emitter and a collector; (b) forming a second transistor comprising a base, a collector and an emitter, said bases of said first and second transistors being coupling together; (c) forming a current buffer circuit coupled to said bases of said first and second transistors and operable to supply base drive current to said first and second transistors; and (d) forming circuitry for applying a voltage proportional to absolute temperature between said emitters of said first and second transistors; (e) wherein said step of forming circuitry for applying a voltage proportional to absolute temperature comprises the steps of: (f) forming resistive circuitry coupled between said emitters of said first and second transistors; and (g) forming circuitry for supplying a current proportional to absolute temperature coupled to said emitter of said first transistor and said resistive circuitry to cause current to flow through said resistive circuitry, such that the current flowing through the resistive circuitry creates said voltage proportional to absolute temperature; (h) wherein the step of forming circuitry for supplying a current proportional to absolute temperature comprises the step of forming a resistor, the value of the current porportional to absolute temperature inversely proportional to the value of the resistor such that the gain of the amplifier is proportional to the ration of the value of the resistance of the resistive circuitry to the value of the resistance of the resistor.

1990-02-07

en

1991-02-05

US-3600041D-A

Suction conveyer ABSTRACT A suction conveyor for conveying material such as rice, wheat, barley, beans and maize. The suction conveyor of the invention comprises a conveying mechanism having a suction fan by suction air and particular mechanical separating means for separating air from the conveying material disposed in a suction passage at a preceding position before the suction fan. The material separated from the suction air by the mechanical separating means is discharged from the suction conveyor by means of air blowing. United States Patent [72] Inventors Shuichi Hirano l9, Kamiichlmachi Mikkachi, Nakaniikawa-gun, Toyama-ken; Seiichi Noda, 2-54, Nanazukamachi, Kizu, Kahoku-gun, Ishikawa-ken, both of, Japan [21] App]. No. 773,604 [22] Filed Nov. 5, 1968 [45] Patented Aug. 17, 1971 [54] SUCTION CONVEYER 5 Claims, 11 Drawing Figs. [52] U.S. Cl 302/23, 302/50 [51] Int. Cl 865g 53/04 [50] Field of Search 302/23, 50 [5 6| References Cited UNITED STATES PATENTS 908,445 1/1909 Carlton 302/23 Williams Ayers..... 9/1959 Burns..." 9/1965 Panning FOREIGN PATENTS 10/1953 France Primary Examiner-Andres H. Nielsen Attorneys- Robert E. Burns and Emmanuel J. Lobato ABSTRACT: A suction conveyor for conveying material such as rice, wheat, barley, beans and maize. The suction conveyor of the invention comprises a conveying mechanism having a suction fan by suction air and particular mechanical separating means for separating air from the conveying material disposed in a suction passage at a preceding position before the suction fan. The material separated from the suction air by the mechanical separating means is discharged from the suction conveyor by means of air blowing. PATENTEU AUGI 1 Ian SHEET 2 OF 4 PATENTEU nus! (I971 3.600.041 sum 3 of 4 PATENIED AUG] 7 4971 SHEET l 0F 4 SUCTION CONVEYER This invention relates to a suction conveyor for continuous conveyance, by sucking in various materials to be conveyed such as rice, wheat, barley, beans and maize. It is necessary to provide a feeding device for the materials when belt conveyor screw conveyor or bucket conveyor is used for conveying these materials and in case of an unloader in which the materials are charged into a chamber in which rotating vanes are provided and are flung upward by the rotation of the vanes, there is a possibility of damage of the conveyed material due to the materials striking the vanes. A principal object of the present invention is to provide an improved suction conveyor having very small and compact construction, for continuously conveying various materials, such as rice, wheat, barley, beans and maize with economical condition. Another object of the present invention is to provide a suction' conveyor having improved construction by which the damage of the conveyed material can be prevented as the conveying materials do not pass through it. When the suction conveyor of the present invention is used, it is only necessary to insert into the accumulated material a flexible suction hose attached to the suction pipe which is connected to the suction fan chamber, thereby only the material is sucked'together with the outside air and only the material is led to the discharge pipe connected to the suction fan chamber while the sucked air is separated from the material, and the material can be transported to any desired place by way of a discharge-wind caused by the separated air. Consequently, the suction conveyor of the present in'vention can be constructed as simple and compact, further the damage to the conveyed material can be prevented as the materials do not pass through it, the loading, unloading and conveyance of thematerials can be carried out automatically, continuously and effectively by easy handling of the suction conveyor of the invention. The objects and advantages of the invention will be more fully understood from the following description and claims in conjunction with the accompanying drawings which illustrate by way of examples in accordance with the invention. In the drawings: FIG. 1 is a lengthwise sectional views'of the first embodiment of the suction conveyor of the invention, FIG. 2 is a plan sectional view of the suction conveyor shown in FIG. 1, FIG. 3 is a side view, partly in section, of the second embodiment of the suction conveyor of the invention, FIGS. 4, and 6 are sectional views of the suction conveyor of the invention, wherein FIG. 4 is the vertical sectional view taken along line 4-4 in FIG. 5, FIG. 5 is the plan sectional view taken along line 5-5 in FIG. 4, while FIG. 6 is the sectional view taken along line 6-6 in FIG. 4, FIG. 7 is a plan sectional view of the fourth embodiment of the suction conveyor of the invention, FIG. 8 is a sectional view, taken along line 8-8, tion conveyor shown in FIG. -7, FIG. 9 is a sectional view, taken along line 9-9, of the suction. conveyor shown in FIG. 7, FIG. 10 is an elevational view of the cover used for the suction conveyor shown in FIG. 7, FIG. 11 is an elevational view of the fan of the suction conveyor shown in FIG. 7. The suction conveyor is provided with a suction fan comprising a spiral type circular body 2. A suction aperture 3 is provided at the middle of a sidewall of the circular body 2 and a discharge pipe 11 is connected to a terminal opening of the spiral air passage defined by the peripheral wall of the circular body.2. The discharge pipe 11 extends straightaway. A cylindrical air chamber 12 is connected to the suction aperture 3 of the inlet side of the circular body 2 and mounted concentriof the succally with the circular body 2. Suction holes 13 are provided at the base portion of the cylindrical air chamber 12 before and behind, and air passages 14 which coincide with the suction holes 13 are provided at the peripheral portion of the cylindrical air chamber 12, and an adjusting ring 16 to which a handle 15 is disposed, is mounted on the peripheral portion of the chamber 12 such that it is only tumable. A rotating shaft 17 is supported by bearings 18a, 18b mounted on the circular body 2 and the air chamber 12, and passes through the center of the circular body 2 and the air chamber 12. A fan 19 disposed in the circular body 2 is secured to the shaft 17, a driven pulley 20 and the driving pulley 21 are mounted on a parts of the shaft 17 which extend outside the air chamber 12. An inverted U-shaped suction pipe 22 is connected to an opening at the upper wall of the top portion of the air chamber 12 with a flexible tube 23 disposed in the intermediate portion. The suction pipe 22 is disposed parallel to the discharge pipe 11. A projecting portion formed at the forward portion of the suction pipe 22 faces the discharge pipe 11 and its tip portion is inclined forward and downward so that the opening formed at the projecting portion is connected with the open ing of the discharge pipe 11 by means of a transfer tube 24 in such a manner that the opening formed at the projecting portion faces the opening of the upper wall. A screw conveyor 25 is disposed with about half of the forward part of the suction pipe 22 and its other half in the transfer tube 24. One end portion of the screw conveyor 25 is formed by a brush screw 26 and the other part of it is formed of metal screw 27, a rotating shaft 29 of the screw conveyor 25 protrudes at an end of it which is supported by a bearing 28 mounted on one side of the suction pipe 22. A belt 31 is looped around a pulley 30 secured to the tip of the rotating shaft 29 and the driving pulley 21. A space 32 is formed in the tip end of the transfer tube 24 and a screen 24 is disposed to the upper portion of the screw conveyor 25 which is inside the forward portion of the suction pipe 22 but above the screw conveyor 25, that is, the screen 33 is located at the position opposite the suction side and adjacent to the screw conveyor 25. The screen 33 is connected the transfer tube 24. The mesh of the screen 33 is such that the conveying material does not pass through it. A conical-shaped shutter cover end of the transfer tube 24. The conical-shaped shutter cover 34 is secured to a rod 36 slidably passing through a bearing sleeve 35 which is secured in the inside wall of the discharge pipe 11. A spring 39 is inserted between a knob 37 secured to the projecting portion of the base of the rod 36 and .the discharge pipe 11, while a spring 28 is inserted between a bearing sleeve 35 and the discharge pipe 11, both springs 38, 39 are mounted on the rod 36. Therefore the conical-shaped shutter cover 34 is normally pressing against the outlet of the transfer tube 24 by the spring 38 to close the outlet. A guide plate 40 is disposed in an inwardly extending manner on the wall of one side of the discharge pipe 11 between the conicalshaped shutter cover 34 and the spiral-type circular body 2 of the suction fan 1, and a section hose 41 made of a certain flexible material is connected to the tip of the suction pipe 22 by way of a flexible tube 42 having a suitable length, and a suction nozzle (not shown) is connected to the tip of the suction hose 4]. Next, an example of the operation of the suction conveyor proposed, as described above, is explained for suction conveyance of materials such as rice, wheat, beans, etc. When power is transmitted to the pulley 20, the rotating shaft 17 and the fan attached to the shaft 17 rotate, and at the same time, power is transmitted from the pulley 21 to rotating shaft 29 by way of the pulley 30, and the screw conveyor 25 rotates. Then, the adjusting ring 16 is turned by means of the handle 15 so that the passages 14 and the suction holes of the air chamber 12 do not coincide to prevent entrance of outside air into the air chamber 12 from the passages 14 and the suction holes 13. The suction nozzle (not shown) attached to the tip of the suction hose 41 is inserted into the accumulated material 34 disposed at the outlet by which the material is sucked into the suction hose 41 together with the outside air by the suction effect of the rotating fan 19, then sucked into the suction tube 22 by way of the flexible tube 42 and strikes screw conveyor 25 where the air passes through screen 33 and then into the air chamber 12 to separate the material from-the air. Air is sucked into the suction fan -1 and this suction wind flows into the discharge pipe 1 l and is discharged outside the machine from its open end. On the other hand, the material which has been separated from the air is sent to the space 32 at the tip portion of the transfer tube 24 along the inside surface of the screen 33 by means of brush screw 26, metal screw 27 of the screw conveyor 25, and when the space becomes filled with the material, the conical-shaped shutter cover 34 and rod 36 recede gradually against the spring 38 in accordance with the pressure of the material sent into space 23 to form a gap between the conical shaped shutter cover 34 and the outlet at the tip of the transfer tube 24, the material in the space 32 is pushed out into the discharge pipe 11 through the above-mentioned gap, during which reverse wind into the transfer tube 24 is prevented by the conical-shaped shutter cover 34, the material which has been introduced into discharge pipe 11 is transported by the discharge wind blown into discharge pipe 11 from the suction fan 1 and is discharged far away outside the machine from the mouth of the pipe 11. Suction conveyance of the material is carried out continuously in this manner. And, when the operation is completed, the adjustment ring 16 is turned by means of the handle and its passages 14 and the suction holes 13 of the air chamber 12 are made to coincide, by which outside air passes directly into the air chamber 12 from the suction holes 13. This is sucked into suction fan 1 from the suction hole by which the effect of sucking in the material from the suction hose 41 together with outside air is stopped. Also, when the knob 37 is grasped and pulled outward against thespring 38, the rod 36 and the conical-shaped shutter cover 34 are pulled to open the outlet of transfer tube 24 to drop residual material in the space 32 into the discharge pipe 1 1 from its outlet and is transported and discharged outside the machine by the discharger air blown from the suction fan 1. Referring to FIG. 3 a fan chamber is disposed between the suction fan 1 and discharge pipe 11 shown in FIGS. 1 and 2. A discharge fan chamber 43 for discharging air is installed parallel and concentrically with the outside of the suction fan 1. The discharge fan chamber 43 comprises a circular body 44, suction holes 35 are disposed at the middle of both sidewalls of the discharge fan chamber 43. The inner suction hole 45 and circumferential wall opening of the circular body 2 of the suction fan 1 are connected by means of an air passage 46, and the discharge pipe 11 is connected to the circumferential wall opening of the circular body 44. The rotating shaft 17 passes through the air chamber 12 and the circular bodies 2, 44 concentrically, and is supported by the bearings 18a, 18b and the fan 19 is secured to the part of the shaft positioned inside its circular body 2 and a fan 47 to the part which extends into the circular body 44. All other symbols are the same as those in F165. 1 and 2. In the second embodiment of the suction conveyor mentioned above, the shaft 17 rotates together with the fans 19, 47 when the pulley is driven. Air, which is sucked into the circular body 2 by the fan 19 is blown out to the air passage 36 to be sent to the suction opening 45 of the fan chamber 44, and at the same time, is sucked into the fan chamber 44 by the sucking effect of the fan 47. Also, outside air is sucked into the fan chamber 44 from the outer suction hole 45, these winds are blown into the discharge pipe 11. Therefore the material, which is conveyed into the discharge pipe 11 from the transfer tube 24, is transported and discharged outside the suction conveyor by its discharge wind. In the above-mentioned two embodiments of the invention, the vanes of the screw conveyor may be formed with a brush or elastic material such as rubber, or it may be made of metal with brush or rubber mounted on its edge portion, the air passage may be improved by making the vanes in the form of a screw ribbon and the clearance between the screw conveyor 24, and the screen 33 is set appropriately in accordance with the kind of materials used in order to prevent damage to the screw conveyor itself, and at the same time, the screen 33 can be cleaned in order to prevent plugging up of the screen openings. Referring to FIGS. 4, 5 and 6, the suction conveyor of the third embodiment is provided with a suction fan chamber of the circular body type 48 which is partitioned into two chambers by a partition 49 in which an air hole is provided in the middle. A suction part 50 is formed in the middle of a sidewall of the fan the clearance 48, and a suction pipe 51 is connected with the kind suction part 50 and extends toward the position facing the forward part of the suction fan chamber 48. A discharge pipe 52 is connected to an opening formed at the lower part of the circumferential wall of the other side of the suction fan chamber 48. A rotating shaft 53 passes through the center of the suction fan chamber 48 and is supported by bearing parts mounted upon the other wall of the chamber 48. A pair of fans 54 are secured to the rotating shaft 53, in such a way that the fans 54 are installed in the respective chambers partitioned by the partition 49. A laterally attached cylindrical transfer tube 55 is connected with the suction pipe 51 at its front end, a suction inlet 56 is connected with an inlet portion of the transfer tube 55, a discharge tube 57 for conveying material into the discharge pipe 52 is connected to the other end of the transfer tube 55. A suction hose 58 made of flexible material is connected to the suction inlet 56 and the opening at the lower end of the discharge tube 57 is connected to the opening formed at the upper surface of the discharge pipe 52. A cylindrical screen 59 is concentrically disposed inside cylindrical transfer tube 55. The mesh of the screen 59 is provided with a predetermined size so that the free passing of the conveying material can be satisfactorily prevented. The inlet end of the cylindrical screen 59 is connected to the suction inlet 56 and the other end to the discharge tube 57, respectively, further the screen 59 is secured inside the transfer tube 55. A screw conveyor 50 is disposed in the cylindrical screen 59. A rotating shaft 61 is supported by the bearing part provided at the outer wall of the discharge tube 57, and the belt 64 is looped around a pulley 62 rigidly mounted on the shaft 61 and a pulley 63 rigidly mounted on the rotating shaft 53 of the fans An outlet shutter cover 65 is connected to the upper opening of the discharge pipe 52. A rod 66 pivoted to the discharge pipe 52 is secured to one side of the outlet shutter cover 65, and a weight 67 is slidably mounted on a bent portion of one end of the rod 66 so as to always press the outlet shutter cover 65 against the outlet of the discharge tube 57. A driven pulley 68 is rigidly mounted on one end of the rotating shaft 53. When the pulley 68 is driven the rotating shafts 53 and 61 are rotated by the pulley 63, the belt 64 and the pulley 62 to rotate the fans 54 and the conveyor screw 60. A suction nozzle not shown is attached to the tip of the suction hose 58. When the suction nozzle is inserted into the accumulated material, the material is sucked into the cylindrical screen 59 together with the outside air by way of the suction inlet 56 of the suction pipe 51. The air passes through the screen 59 and is sucked into the section tube 51 to separate the material from the air, the air is then sucked into the suction fan chamber 48 by way of the suction inlet 50 and at the same time, the sucked air passes inside the discharge tube 52 by the blowing action due to the rotation of the fans 54 and is discharged outside the machine from the opening at the end of the tube. On the other hand, the material separated from the air is gradually conveyed into the discharge tube 57 by the rotating screw conveyor 60 along the inside surface of the cylindrical screen. 59. The outlet shutter cover 65 is pushed open by the material. The outlet shutter cover 65 is opened by its weight with the rod 66 as the fulcrum against the weight 67 moves downward to open the outlet of discharge tube 57. The material drops from the outlet at the upper surface into the discharge pipe 52 and at the same time, it is conveyed outside the machine by the ejection wind passing in the discharge pipe 52 to carry out suction conveyance of the material continuously; Also, more than two partitions, having holes in the middle, may be provided in the suction fan chamber 48 to divide the suction fan chamber 48 into more than three chambers and provide a fan in each chamber in order to make the wind stronger. Also, this suction fan chamber may be a single chamber. Furthermore, the same action can be obtained by attaching a spring to the rod 66 of the outlet shutter cover 65 in place of a weight. Referring to FIGS. 7, 8, 9, l0 and 11, the fourth embodiment of the suction conveyor of the invention is provided with a cylindrical fan chamber 69 formed into trunco-conical form, and a suction pipe 70 is connected to the opening at the inlet end of the fan chamber 69, and a discharge pipe 71 at the outlet at the other end of the fan chamber, respectively. A cylinder 72 is disposed in the suction fan chamber 69 in such away that the cylinder 72 is positioned concentrically with the suction fan chamber 69, and the cylinder 72 is located at the intermediate part in the suction fan chamber 69 at the side of discharge pipe 71. A trunco-conically. shaped transfer tube 74 is rigidly connected to the suction fan chamber 69 by means of supporting rods and is provided with a screen having particular size of the mesh for preventing passing of the conveyed material. The end portion of the tube 74 having small diameter is rigidly connected to the tip of the suction pipe 70 at a position facing the cylinder 72. The end portion of the tube 74 having large diameter is fixed to the inside surface of the intermediate part of the suction'fan chamber 69 so as to dispose the transfer tube 74 inside the suction passage fonned between a fan 75 and the suction pipe 70. The fan 75 is disposed at the periphery of the cylinder 72, and its central shell part is rotatably supported by the cylinder 72 and the edges of the vanes of the fan 75 are disposed such that they are close to the inside circumferential surface of the cylindrical fan chamber 69. A pair of bearings 76 and 74 are disposed at the center of the inlet portion and the other end of the cylindrical fan chamber 69, respectively, so as to support in the chamber 69 by means of arms 78 and 79. The bearings 76 and 77 support both end portions of the rotating shaft 80 whichpasses through the suction fan chamber 69 and the cylinder 72. A screw conveyor 81 is secured to the rotating shaft 80, in the cylinder 72. The screw conveyor 82 having helical shape is disposed inside the transfer tube 74 in such a way that the peripheral surface of the screw conveyor 82 is closely positioned to the inside wall of the transfer tube 74. The helical shaped portion of the screw conveyor 72 is made of certain metallic wire. An end of the screw conveyor 82 having small diameter is connected to an inlet end of the screw conveyor 81 and an extending end of the screw conveyor 82 having large diameter is fixed to the rotating shaft 80. A conical cover 83 is disposed to a position facing the opening of the other end of the cylinder 72. A central hole of the cover 83 is fitted slideably on the rotating shaft 80 and at the same time, a spring 84 is mounted on the rotating shaft 80 between a base plate of the cover 83 and the bearing 77 so that the cover 73 is normally maintained closed condition by spring 84 while contacting the outlet of the other end of the cylinder 72. A pulley 85 is mounted on the back surface of the central shell of the fan 75 and is disposed inside a shutter cover 86 which is secured to the inside of the cylindrical fan chamber 69, and a belt 87 which passes through an aperture in the circumferential wall of the cylindrical fan chamber 69 is looped around the pulley 85. A pulley 88 is secured to the back end of the rotating shaft 80 and is disposed inside the cover 89 which is fixed inside the discharge pipe 71, and a belt 90 which passes through the aperture of the circumferential wall of the discharge pipe 71 is looped around the pulley 88. Next, the operation of the suction conveyor of the abovementioned forth embodiment of the invention is explained. First, a flexible hose, not shown, is connected to the opening at the tip of the suction pipe 70. Then thefan 75 and the rotating shaft are driven by'the belt 87 and the pulley 85, and the belt and the pulley 88, respectively, to rotate the fan 75 at a high speed, and to drive the rotating shaft 80 and the screw conveyor 82 at a slow speed, respectively. When the hose connected to the suction pipe 70 is inserted into the accumulated material, the material is sucked into the suction fan chamber 69 by way of the suction pipe 70 together with outside air. The material and air are separated by means of the screen which forms the transfertube 74. The material is moved through the transfer tube 74 and the cylinder 72 which is connected to the transfer tube 74 by means of the screw conveyors 82 and 81, respectively, until the material reaches the outlet of the cylinder 72. The cover 83 slides against the spring 84 by the pressure of the material which is moved gradually to the outlet to form a gap between the cover 83 and the outlet. The material drops from this gap into the suction fan chamber 69 and at the same time, it passes through the discharge pipe 72 by the wind pressure caused by the rotation of the fan- 75 and is conveyed outside the suction fan chamber 69. In this invention, a suction fan chamber to which a suction pipe and a discharge pipe are connected is provided. Transfer tube provided with a screen for separating air and the material to be sucked and conveyed, and a screw for moving the separated material is provided in the sucked air passage. The outlet of the transfer tube is connected to the discharge pipe of the suction fan chamber, and a cover is maintained under pressure at this connecting part so that the material is sucked together with outside air into the suction tube. The material is separated from the sucked air by means of the screen installed in the suction passage. The material is conveyed and introduced into the discharge pipe and conveyed by means of discharged wind from the fan chamber without passing through the fan chamber only, by driving the fan shaft and the screw conveyor and inserting the opening at the tip of the flexible suction hose connected to the suction pipe into the accumulated material. While'a preferred embodiment of the suction conveyor according to the invention has been shown and described, it will be understood that many modifications and changes can be made within the scope of the invention. What We claim is: 1. A suction conveyor comprising a suction fan chamber having a suction inlet aperture and an outlet aperture, a suction pipe connected to said suction inlet aperture, a discharge pipe connected to said outlet aperture, said suction pipe and discharge pipe each having an opening intermediate its length, a cylindrical transfer tube having its ends connected to said openings, a screw conveyor coaxially mounted for rotation within said transfer tube and extending into said suction pipe, a screen mounted transversely within said suction pipe between said transfer pipe and fan chamber and disposed immediately adjacent said screw conveyor, shutter cover means mounted within said discharge pipe and normally pressing against the end of said transfer tube connected to said discharge pipe. 2. A suction conveyor for pneumatically conveying materials such as grains including, in combination, an air chamber having inlet and outlet openings and having pneumatic suction means mounted therein for causing air to flow through said chamber between said openings; a suction pipe connected to said inlet opening; a discharge pipe connected to said outlet opening; a transfer tube interconnected between said suction and discharge pipes for bypassing said air chamber; a screw conveyor disposed within said transfer tube for carrying grain from said suction pipe to said discharge pipe; a screen disposed within said suction pipe between said transfer tube and said air chamber; and a shutter cover positioned to block the transfer tube at its connection to said discharge pipe; an improvement comprising means engaging said cover for releasably urging said cover into said blocking position and to release said cover under the force of grain advanced by said screw conveyor, and suction adjusting means wherein the walls of said air chamber define a plurality of suction holes disposed on the side of said pneumatic suction means opposite said outlet opening, and a slide cover slideably mounted on the wall of said air chamber for selective movement to open or close said suction holes. 3. A suction conveyor for pneumatically conveying materials such as grains including, in combination, an air chamber having inlet and outlet openings and having pneumatic suction means mounted therein for causing air to flow through said chamber between said openings; a suction pipe connected to said inlet opening; a discharge pipe connected to said outlet opening; a transfer tube interconnected between said suction and discharge pipes for bypassing said air chamber; a screw conveyor disposed within said transfer tube for carrying grain from said suction pipe to said discharge pipe; a screen disposed within said suction pipe between said transfer tube and said air chamber; and a shutter cover positioned to block the transfer tube at its connection to said discharge pipe; an improvement comprising means engaging said cover for releasably urging said cover into said blocking position and to release said cover under the force of grain advanced by said screw conveyor, suction and discharge fans included in said pneumatic suction means, said fans being coaxially mounted within said air chamber, said air chamber having an air supply opening therein on the side of said suction fan opposite said inlet opening, whereby said discharge fan discharges air drawn both from said suction fan and said air supply opening. 4. A suction conveyor for pneumatically conveying materials such as grains including, in combination, an air chamber having inlet and outlet openings and having pneumatic suction means mounted therein for causing air to flow through said chamber between said openings; a suction pipe connected to said inlet opening; a discharge pipe connected to said outlet opening; a transfer tube interconnected between said suction and discharge pipes for bypassing said air chamber; a screw conveyor disposed within said transfer tube for carrying grain from said suction pipe to said discharge pipe; a screen disposed within said suction pipe between said transfer tube and said air chamber; and a shutter cover pivotally connected to said discharge pipe to block said discharge pipe at its connection to said air chamber, said shutter cover having a rod attached thereto, and a weight connected to said rod to urge said cover into said blocking position, whereby said materials carried by said screw conveyor push said cover pivotally away from said blocking position. 5. The invention as set forth in claim 1, in which said screw conveyor comprises a brush portion disposed to engage said screen for cleaning said screen upon rotation of said screw conveyor. 1. A suction conveyor comprising a suction fan chamber having a suction inlet aperture and an outlet aperture, a suction pipe connected to said suction inlet aperture, a discharge pipe connected to said outlet aperture, said suction pipe and discharge pipe each having an opening intermediate its length, a cylindrical transfer tube having its ends connected to said openings, a screw conveyor coaxially mounted for rotation within said transfer tube and extending into said suction pipe, a screen mounted transversely within said suction pipe between said transfer pipe and fan chamber and disposed immediately adjacent said screw conveyor, shutter cover means mounted within said discharge pipe and normally pressing against the end of said transfer tube connected to said discharge pipe. 2. A suction conveyor for pneumatically conveying materials such as grains including, in combination, an air chamber having inlet and outlet openings and having pneumatic suction means mounted therein for causing air to flow through said chamber between said openings; a suction pipe connected to said inlet opening; a discharge pipe connected to said outlet opening; a transfer tube interconnected between said suction and discharge pipes for bypassing said air chamber; a screw conveyor disposed within said transfer tube for carrying grain from said suction pipe to said discharge pipe; a screen disposed within said suction pipe between said transfer tube and said air chamber; and a shutter cover positioned to block the transfer tube at its connection to said discharge pipe; an improvement comprising means engaging said cover for releasably urging said cover into said blocking position and to release said cover under the force of grain advanced by said screw conveyor, and suction adjusting means wherein the walls of said air chamber define a plurality of suction holes disposed on the side of said pneumatic suction means opposite said outlet opening, and a slide cover slideably mounted on the wall of said air chamber for selective movement to open or close said suction holes. 3. A suction conveyor for pneumatically conveying materials such as grains including, in combination, an air chamber having inlet and outlet openings and having pneumatic suction means mounted therein for causing air to flow through said chamber between said openings; a suction pipe connected to said inlet opening; a discharge pipe connected to said outlet opening; a transfer tube interconnected between said suction and discharge pipes for bypassing said air chamber; a screw conveyor disposed within said transfer tube for carrying grain from said suction pipe to said discharge pipe; a screen disposed within said suction pipe between said transfer tube and said air chamber; and a shutter cover positioned to block the transfer tube at its connection to said discharge pipe; an improvement comprising means engaging said cover for releasably urging said cover into said blocking position and to release said cover under the force of grain advanced by said screw conveyor, suction and discharge fans included in said pneumatic suction means, said fans being coaxially mounted within said air chamber, said air chamber having an air supply opening therein on the side of said suction fan opposite said inlet opening, whereby said discharge fan discharges air drawn both from said suction fan and said air supply opening. 4. A suction conveyor for pneumatically conveying materials such as grains including, in combination, an air chamber having inlet and outlet openings and having pneumatic suction means mounted therein for causing air to flow through said chamber between said openings; a suction pipe connected to said inlet opening; a discharge pipe connected to said outlet opening; a transfer tube interconnected between said suction and discharge pipes for bypassing said air chamber; a screw conveyor disposed within said transfer tube for carrying grain from said suction pipe to said discharge pipe; a screen disposed within said suction pipe between said transfer tube and said air chamber; and a shutter cover pivotally connected to said discharge pipe to block said discharge pipe at its connection to said air chamber, said shutter cover having a rod attached thereto, and a weight connected to said rod to urge said cover into said blocking position, whereby said materials carried by said screw conveyor push said cover pivotally away from said blocking position. 5. The invention as set forth in claim 1, in which said screw conveyor comprises a brush portion disposed to engage said screen for cleaning said screen upon rotation of said screw conveyor.

1968-11-05

en

1971-08-17

US-93188592-A

Latch release mechanism for mating electrical connectors ABSTRACT A latch-release mechanism is disclosed for a pair of electrical connectors movable toward each other in a mating direction into a mated condition. The mechanism includes a latching device on one of the electrical connectors for latchingly engaging a latch on the other electrical connector in response to movement of the connectors into the mated condition. A releasing device is provided for releasing the latching device on the one connector from latching engagement with the latch on the other connector in response to movement of the latching device generally perpendicular to the mating direction of the connectors. This is a continuation of copending application Ser. No. 07/792,538 filed on Nov. 13, 1991, now abandoned. FIELD OF THE INVENTION This invention generally relates to the art of electrical connectors and, particularly, to a latch-release mechanism for a pair of mating electrical connectors. BACKGROUND OF THE INVENTION Mating electrical connectors often are provided with latch-release mechanisms for holding the connectors in mated condition. The most common type of latching mechanism includes a pair of cantilevered spring arms projecting from one electrical connector for snapping into latched engagement with complementary latch means on a mating connector. The spring latch arms may be integrally molded with the housing of the connector, or the latch arms may be fabricated of spring metal material mounted to the outside of the connector housing. Of course, a variety of other latch-release mechanisms have been proposed and/or available. One of the problems with latch-release mechanisms of the character described is that access must be had to the mated connectors in order to release the latching mechanism to unmate the connectors. Most often, the latch-release mechanisms are disposed on opposite sides of the connectors and, consequently, access must be had to the connectors from the sides thereof in order to release the latching mechanism. It might be proposed to locate the latching mechanisms on the top and bottom of the connectors, rather than the sides thereof, but access to the bottom of a pair of mating connectors often is unavailable. A single latch on either side or the top or bottom of a pair of mating connectors does not adequately mate the connectors. An example of an environment wherein access to a pair of mating connectors is very limited, is in the field of power cables for interconnecting power lines between panels of a modular wall panel system. Such systems are used to divide a given area into distinct work stations. Most often, tracks are provided along the bottom edge of the wall panels, and power cables run in the tracks to supply power to the various work stations. Power lines usually run in the tracks of each respective panel, and power blocks or connectors are provided at opposite ends of the panels for interconnection. Obviously, with the tracks running along the bottom edges of the panels, access to the mated connectors from the bottom thereof is blocked by a floor structure. The wall panels, themselves, are relatively thin, and, consequently, access to the sides of a pair of mating connectors within the wall panels is limited or totally unavailable. This invention is directed to solving the problems described above by providing a latch-release mechanism which is latched in response to movement of a pair of electrical connectors in a mating direction and which is released in a direction generally perpendicular to the mating direction. SUMMARY OF THE INVENTION An object, therefore, of the invention is to provide a new and improved latch-release mechanism for a pair of electrical connectors movable toward each other in a mating direction into a mated condition. Generally, in the exemplary embodiments of the invention, a latching device is mounted on one of the electrical connectors for latchingly engaging latch means on the other electrical connector in response to movement of the connectors into their mated condition. Specifically, release means are provided for releasing the latching device from latching engagement with the latch means in response to movement of the latching device generally perpendicular to the mating direction of the connectors. In some embodiments of the invention, the latching device is mounted on one of the electrical connectors for sliding movement generally perpendicular to the mating direction of the connectors. The latching device on one of the electrical connectors, therefore, is moved from its latching engagement with the latch means on the other electrical connector perpendicular to the direction of mating of the connectors. In the preferred embodiments, the latch means on the other electrical connector include cam means for sliding the latching device generally vertically upwardly when the electrical connectors are mated in a generally horizontal direction. The latching device drops by gravity into latching engagement with the latch means when the connectors are mated. In order to release the latching mechanism, the latching device simply is lifted in order to unmate the connectors. In another embodiment of the invention, the latching device includes a spring arm on one of the electrical connectors biased into latching engagement with the latch means on the other electrical connector. The release means is provided in the form of a separate releasing device movably mounted on the one electrical connector for moving the spring arm out of latching engagement with the latch means in response to movement of the releasing device generally perpendicular to the mating direction of the connectors. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: FIG. 1 is an exploded perspective view of a latching device according to the invention, for slidably mounting on an electrical connector as shown; FIG. 2 is a section taken generally along line 2--2 of FIG. 1; FIG. 3 is a perspective view of a mounting cap for a pair of mating electrical connectors with latch means for latchingly engaging a pair of the latching devices of FIG. 1; FIG. 4 is a section taken generally along line 4--4 of FIG. 3; FIG. 5 is a section taken generally along line 5--5 of FIG. 3; FIG. 6 is an exploded perspective view of a second embodiment of a latch-release mechanism according to the invention; FIG. 7 is a vertical section taken generally along line 7--7 of FIG. 6, with the releasing device in its inoperable position while the mating electrical connectors are mated; FIG. 8 is a view similar to that of FIG. 7, with the releasing device moved to a position of releasing the latching devices; FIG. 9 is an exploded perspective view of a third embodiment of a latch-release mechanism according to the invention; and FIG. 10 is a fragmented section through the positioning detent means for the latching device of FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in greater detail, and first to FIGS. 1-5, these figures show a first embodiment of the invention for mating at least one pair of electrical connectors, one of which is generally designated 10 in FIG. 1. Only one connector 10 is shown in the drawings because the particular configuration of the mating connectors with which the invention is applicable can vary widely. The one electrical connector shown does illustrate the relevant structure for cooperating with the latch-release mechanisms shown and described herein. More particularly, referring to FIG. 2 in conjunction with FIG. 1, each electrical connector 10 includes generally vertically oriented groove means 12 (FIG. 2) provided by a center rib 14 and two end ribs 16 (FIG. 1). The connector includes a plurality of through passages 18 for receiving appropriate mating male and female terminals coupled to electrical wires which would project out of a rear end 20 (FIG. 2) of each through passage at a rear terminating end 22 (FIG. 1) of the connector. Referring particularly to FIG. 1, a latching device, generally designated 24, includes a side wall 26 having an elongated slot 28 to define a rail 30 having a front edge 32. The latching device provides a receptacle means, between side wall 26 and a pair of side wall flanges 34, for receiving one of the electrical connectors 10 therebetween. Rail 30 has a width for sliding between center rib 14 and end ribs 16 on one side of one of the electrical connectors 10. In other words, end ribs 16 on the connector snap into elongated slot 28 in side wall 26 of latching device 24. Center rib 40 locks behind a front edge 32 of rail 30. Consequently, the latching device can slide vertically of the electrical connector as indicated by double-headed arrow "A" (FIG. 1). FIG. 2 shows rail 30 disposed between ribs 14 and 16. FIG. 1 also shows that latching device 24 has a top wall 36 and a bottom wall 38, each of those walls being provided with a latching aperture 40. Cam ramps 42 are located immediately in front of the latching apertures. It can be seen that both of the cam ramps are curved upwardly for purposes described hereinafter. In addition, a lifting tab 44 is disposed at the rear end of top wall 36, with the lifting tab being bent upwardly for grasping by an operator. Whereas electrical connector 10 includes an integrally molded dielectric housing for receiving the appropriate terminal means, latching device 24 is unitarily fabricated of stamped and formed sheet metal material. FIGS. 3 and 4 show a mounting structure or end cap 45 for one or a pair of electrical connectors similar to electrical connector 10 for mating with one or a pair of electrical connectors mounted in one or a pair of latching devices 24. More particularly, FIG. 4 shows interior walls 46 defining gaps 48 into which a pair of mating connectors, similar to connector 10, are insertable in the direction of arrows "B". The dimensions of the interior walls, as indicated by arrows "C", are such that the walls seat between ribs 14 and 16 (FIG. 1) to lock a pair of similar mating connectors within the end cap structure. The electrical connectors for positioning in end cap 45 are the same as electrical connector 10, except the connectors in end cap 45 and the connectors in latching devices 24 will have different terminals (i.e., male versus female terminals). End cap structure 45 includes top and bottom walls 50 and 52, respectively, which are provided with latch means in the form of ramped latches 54. These ramped latches are sized for snapping into latching engagement within apertures 40 (FIG. 1) in top and bottom walls 36 and 38, respectively, of one or a pair of latching devices 24. In other words, it can be seen in FIG. 3 that two pairs of vertically aligned, horizontally spaced latch ramps 54 are provided on end cap 45. Therefore, the end cap can accommodate two mating electrical connectors for mating engagement with a pair of electrical connectors 10 mounted within a pair of latching devices 24. It can be seen particularly in FIG. 5 that both the upper and lower ramped latches 54 face upwardly from top and bottom walls 50 and 52, respectively. In operation of the latch-release mechanism described above in relation to FIGS. 1-5, an assembly of one electrical connector 10 mounted within one latching device 24 is moved in a mating direction as indicated by arrows "D" for mating with an electrical connector mounted within end cap 45. Normally, this mating direction would be generally horizontal in an environment such as a modular wall panel system as described in the "Background" above. As the respective connectors are mated, a respective vertically aligned pair of the latch ramps 54 will engage the upwardly turned cam ramps 42 of latching device 24, biasing the latching device upwardly in the direction of arrow "E"(FIG. 1). As the respective connectors are moved to their mated condition, latch ramps 54 will become aligned with apertures 40 in the top and bottom walls of latching device 24. When so aligned, the latching device will drop by gravity into a latched condition with the latch ramps 54 locked behind the front edges of apertures 40. Of course, as stated above, since end cap 45 is structured to receive a pair of mating connectors, two assemblies of connectors 10 and latching devices 24 can be mated and latched within the end cap. When it is desired to release the latch-release mechanism and to unmate the connectors, an operator simply lifts latching device 24, by lifting on tab 44 at the top of the latching device, to move the latching device upwardly whereby latch ramps 54 clear apertures 40 and the connectors can be unmated. This vertical movement of the latching device as indicated by arrows "A" and "E", generally perpendicular to the mating direction "D" in FIG. 1, is afforded by the sliding engagement of rail 30 of the latching device disposed between ribs 14 and 16 on the side of the electrical connector. FIGS. 6-8 show a second embodiment of the invention wherein one electrical connector, generally designated 58, is mateable with a second electrical connector 60. Connectors 58 and 60 are shown somewhat schematic and are substantially the same as electrical connector 10 (FIG. 1) except for the different embodiment of a latch-release mechanism. More particularly, the one electrical connector 58 is provided with a pair of cantilevered latch arms 62 on opposite sides thereof, the latch arms terminating in distal ends having cam surfaces 64 leading to latching hooks 66. The latch arms project forwardly beyond the mating end of the connector for engagement with latch bosses 68 molded integrally and projecting outwardly from the sides of mating electrical connector 60. Each latch boss 68 includes a cam ramp 70 and a latching shoulder 72. Therefore, when electrical connectors 58 and 60 are moved in a mating direction as indicated by arrows "F", cam ramps 64 on latch arms 62 will engage cam ramps 70 on latch bosses 68 to bias the latch arms generally horizontally outwardly in the direction of arrows "G". When the connectors are fully mated, latching hooks 66 on latch arms 62 lock behind latching shoulders 72 of latch bosses 68 to latch the connectors in mated condition. In order to release latch arms 62 out of latching engagement with latch bosses 68, a generally U-shaped releasing device, generally designated 74, is slidably mounted onto the top of connector 58. The releasing device has a pair of legs 76 provided with integrally molded ribs 78 on the inside thereof. The ribs slide in a pair of vertically oriented grooves 80 formed in opposite sides of electrical connector 58. Therefore, latching device 74 is mounted onto the top of electrical connector 58 in the direction of arrow "H" until distal ends 82 of legs 76 are located below latch arms 72 of the connector. This position is shown in FIG. 7. It can be seen that distal ends 82 have cam surfaces 84 for camming latch arms 62 outwardly to enable the latching device to be mounted on the connector. The distal ends also have stop surfaces 86 to define an upper limit position of the latching device, relative to connector 58, as shown in FIG. 7. In operation of the latch-release mechanism shown in FIGS. 6-8, with releasing device 74 in an elevated position as shown in FIG. 7, electrical connectors 58 and 60 can be mated in the direction of arrows "F" (FIG. 6), whereupon latch arms 62 and latch bosses 68 of the respective connectors snap into latching engagement. When it is desired to unmate the connectors, latch arms 62 are moved outwardly in the direction of arrows "G" by pushing down on releasing device 74 in the direction of arrow "I" (FIG. 8). Release ramps 88 formed on the outside of legs 76 of the releasing device engage latch arms 62 to bias the latch arms generally horizontally outwardly and perpendicular to the mating direction of the connectors. With releasing device 74 in the position shown in FIG. 8, latch arms 62 are released from latch bosses 68 of connector 60 and the connectors can be unmated. FIGS. 9 and 10 show a third embodiment of a latch-release mechanism according to the invention. More particularly, again, one electrical connector, generally designated 90, is mateable with a second electrical connector, generally designated 92. A latch-release device, generally designated 94, is fabricated of stamped and formed sheet metal material in a generally U-shape to include a pair of legs 96. Inwardly turned ribs 98 are formed along the rear edges of legs 96 for slidably mounting the latch-release device onto the top of electrical connector 90 by means of the ribs being disposed in grooves 100 formed in the sides of the electrical connector. Therefore, latch-release device 94 is mounted onto the top of connector 90 in the direction of arrow "J" and, when so mounted, the latch-release device can slide relative to the connector in the direction of double-headed arrow "K". Means are provided between latch-release device 94 and electrical connector 90 to define at least an upper, but preferably upper and lower positions of the latch-release device relative to the connector. More particularly, referring to FIG. 10 in conjunction with FIG. 9, a detent dimple 102 is formed to project inwardly from each leg 96 for seating into upper and lower detent recesses 104 and 106, respectively, formed in the sides of connector 90. With detent dimple 102 seated in upper detent recess 104 as shown in FIG. 10, an elevated unlatched position of latch-release device 94 is defined. In order to latch electrical connectors 90 and 92 in mated condition, a pair of generally L-shaped slots are stamped in each side wall 96. Each slot has a lower ramp edge 108 leading to a generally vertical latching portion 110 of the slot. Electrical connector 92 has a pair of vertically oriented, spaced latch bosses 112 projecting outwardly from each opposite side of the connector. The latch bosses are oriented for movement into the respective pairs of slots stamped in side legs 96 of latch-release mechanism 94. In operation of the embodiment of the latch-release mechanism shown in FIGS. 9 and 10, electrical connectors 90 and 92 are moved in a generally horizontal mating direction as indicated by arrows "L", with latch-release device 94 in its upper position defined by detent dimple 102 seated in detent recess 104. As the connectors are moved into mated condition, latch bosses 112 engage ramp edges 108 of the slots in legs 96 of the latch-release device. This engagement drives the device downwardly in the direction of arrow "J", moving detent dimple 102 out of detent recess 104 until the dimple reaches an enlarged detent recess 106 wherein the latch-release device can fall downwardly until latch bosses 112 seat into latching portions 110 of the slots in legs 96. The connectors now cannot be unmated. When it is desired to unmate the connectors, an operator lifts latch-release device upwardly, by engaging or grasping a lifting tab 114 on the top of the latch-release device, to move latch bosses 112 out of latching portions 110 of the slots, whereupon the connectors can be unmated. It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. I claim: 1. In a latch-release mechanism for a pair of electrical connectors movable toward each other in a mating direction into a mated condition, including a latching device on one of the electrical connectors for latchingly engaging latch means on the other electrical connector in response to movement of the connectors into said mated condition, the improvement comprising a latching device comprising a spring arm biased into latching engagement with the latch means, release means separate from the connector movable between a locking and unlocking position for releasing the latching device from latching engagement with the latch means in response to movement of the latching device generally perpendicular to said mating direction to the unlocking position, said release means held in the locking position by a ramp on the release means in contact with the spring arm, said release means movable generally perpendicular to said mating direction and comprising a releasing device slidably mounted on the one electrical connector whereby moving the release means to the unlocking position will move the spring arm out of latching engagement with the latch means in response to movement of the latching device generally perpendicular to said mating direction. 2. In a latch-release mechanism as set forth in claim 1, wherein said latching device comprises two spring arms on opposite sides of one of said electrical connectors whereby moving the release means to the unlocking position will move the spring arms in opposite directions out of latching engagement with the latch means.

1992-08-18

en

1993-05-04

US-61721984-A

High-energy laser with multiple phased outputs ABSTRACT A high-energy laser 10 comprising a ring of lesser-powered laser modules 12,14,16 from each of which an output is taken to be projected so that they all arrive in phase on a distant target. To phase-lock the outputs of all the serial laser modules, the path lengths (l) of the laser modules are made equal, the path length around the large loop which includes all the laser modules is made an integral multiple of the laser-module path length, and at least two different feedback loops are employed. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a high-energy laser (HALE) and especially to a HALE consisting of a plurality of lower-power lasers forming a large loop, the outputs of each individual laser remaining in phase with the output of the large loop. 2. Description of the Prior Art In the process of directing laser energy against a remote target to destroy or damage it, a large amount of coherent laser energy must inpinge on the target. The intensity of the laser beams at the target increases with the laser power and with the area of the telescope aperture (telescopes are generally used in this type of laser application). There are practical limits to the size of both the laser and the telescope that can be constructed with the optical precision and power-handling capabilities that are required. Thus, it would be highly desirable to operate with several smaller lasers (less power) and smaller telescopes directed separately at the same target. This requires that the outputs from the various lasers be locked in frequency and phase and that the path lengths from the lasers to the targets be controlled in order for the beams to combine coherently at the target to provide the higher power which is required and desired. OBJECTS OF THE INVENTION An object of this invention is to obtain outputs having the same frequencies from a plurality of lasers, the outputs of the same frequencies of the different lasers being in phase with each other. Another object is to project a beam of high intensity on a target, the beam at the target being composed of in-phase beams from several low-powered lasers which add coherently to provide the high intensity. A further object is to replace a high-power laser using a large telescope with several lower-power lasers using smaller telescopes and yet achieve the same high-intensity beam on the target by combining the lower-power beams at the target. Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. SUMMARY OF THE INVENTION The objects and advantages of the present invention are achieved by placing a plurality, N, of laser modules in a large series loop, or ring, with the output of the last laser being fed to the input of the first laser module. Each laser module has a laser length, l. The resonance condition for modes of resonance of the large ring is: Nl=Kλ.sub.κ where K is an integer, so that the wave reproduces itself after each round trip through the large ring and λ.sub.κ is the wavelength of a mode of oscillation. Each mode which lases must have the same phase at every laser output in order for path-length control to bring the output beams to the target in the same phase. The conditions which are achieved to phase-lock the output of each laser module are: (1) the path lengths (l) of all laser modules are made equal; (2) the path length around the large ring is made an integral multiple of the path length (l) of each module; and (3) at least two feedback loops are used, one being the large series loop. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block, diagram illustrating an embodiment of the invention. FIG. 2 is a schematic diagram illustrating in greater detail the structure of two of the individual lasers shown in block form in FIG. 1. FIG. 3 is a schematic block diagram illustrating another embodiment of the invention. FIG. 4 is a schematic block, diagram illustrating a path-length control system for a laser module. FIG. 5 is a schematic block diagram illustrating the details of the control system block, of FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of FIG. 1, several lasers (1, 2, . . . N) are coupled in series to form one large ring laser 10. Each laser module 12, 14, 16 has a portion of its output (18, 20, 22) coupled out to a telescope (the telescopes are not shown) for projection to a target, a portion coupled to the next laser module in the series and a portion fed back to its own input. In the case of the last laser module 16, the feedback output portion is coupled back to the input of the first laser module 12 to complete the ring. FIG. 2 shows some of the details of two of the laser modules (12 and 14) of typical lasers which can be employed in the implementation of the embodiment of the invention shown in FIG. 1. These lasers are well known in the art and thus will not be completely described herein. The output of each laser is coupled to a scraper, e.g., 24, which reflects a portion 18 to a telescope. Another portion 26 of the output is coupled through the hole in the scraper 24 to a second scraper 28 and a portion 30 fed back to the input of the laser via mirrors 34 and 36 and input scraper 38. A third portion 32 of the output of the first laser 12 is fed as input to the next laser module 14 in the series. The distance around the small ring of the laser module 12 is the path length (l). The distance between the output scrapers (or the output beams) of two successive laser modules (e.g., 12 and 14) in the large ring is also (l). The total length of the large ring is (L=Nl) where (N) is the number of laser modules in the large ring laser 10. Actually, the total length of the large ring should be an integral multiple of Nl, but inserting an additional factor will needlessly complicate the equations to be introduced so Nl will be employed hereinafter to indicate an integral multiple of the laser-module path length (l). The resonance condition for the oscillatory modes of the large ring laser 10 is Nl=Kλ.sub.κ (1) where K is an integer such that the light wave travelling around the large ring reproduces itself after each round trip and λ.sub.κ is the wavelength of the oscillatory mode which results from the particular K value under consideration. Every oscillatory mode in the large ring laser 10 must satisfy the above equation irrespective of what laser spectral line the mode is associated with. Because all the small lasers are coupled in one single large ring, all must oscillate on exactly the same vibrational-rotational (V-J) spectral lines and in exactly the same modes. It is not enough that the outputs of each laser module have exactly the same spectral lines and modes with exactly the same frequencies. The different modes may have different phases, but each mode which lases must have the same phase at each output scraper in order for path length control (of the output beams to the target) to bring them into phase at the target. The resonance condition for the modes given in equation (1) can be rewritten as follows to provide this condition: ##EQU1## where (k) is an integer and (n) is a number that represents a mode, the value of which can be n=0, 1, 2, . . . N. The modes of the large ring fall into (N) classes depending on whether (n) is 0, 1, 2, etc. Clearly, the class of modes with n=0 exactly reproduce themselves after traveling a distance (l) through the large ring. A mode of this class (n=0, ##EQU2## will, therefore, have exactly the same phase at each output scraper at all times. This will be true of every mode of this class no matter what spectral line it is associated with. This is also true if n=N. Furthermore, 1/N of all the longitudinal modes of every V-J spectral line will be of this class, that is, 1/N of all the modes are in phase at each output scraper. The outputs of the small lasers in FIG. 1 will be phase-locked if the large ring can be restricted to lase only on the desired class of modes. This result is achieved if each small ring laser of FIG. 1 has an equivalent length (l) so as to resonantly (regeneratively) amplify only those modes for which (l/λ) is an integer (for the modes for which n=0 or n=N). It is interesting to note that if the large ring were constrained to lase only on every Nth longitudinal mode, these modes could be brought into almost exact phase lock by a small shift in the location of each scraper even if the modes were of some class other than the class n=0. That is, phase lock could be achieved if all modes were of class n=1, for example, so that ##EQU3## However, there is no shift of the scrapers from precisely a separation of (l), because the wavelengths of the different spectral lines (of DF or HF, e.g.) only vary by about ±5%. The method employed herein to set n=0 or n=N so that ##EQU4## does not equal k plus a fraction is to have at least two feedback loops in the device. Thus, in FIG. 1, there is a feedback loop around each laser module and a feedback loop around the large ring fom the output of laser N (16) to the input of laser 1 (12). In FIG. 3, there are two feedback loops, one from the output of laser N (48) to the input of laser 1 (42) and one from the output of laser (N-1) to the input of laser 1 (42). The second feedback loops force the modes generated by the first feedback loop to be only the ones which satisfy the equations ##EQU5## Automatic path length control means would comprise means for sensing and controlling the lengths (l) of the small ring lasers to be exactly ##EQU6## of the length of the large ring. One such means would include (a) a mechanically driven mirror in each small ring, (b) a means for sampling the circulating flux in each small ring (e.g., a small hole in mirror 30 or a small grating in the light path to refract out some light), and (c) a heterodyne detector to detect beat frequencies between the modes of the laser in that sample. When all modes of the large ring lase, heterodyne frequencies will occur at c/Nl, 2c/Nl, 3c/Nl, etc. When only a single class of the desired type lases, the only heterodyne frequencies will occur at c/l, 2c/l, 3c/l, etc. (c is the speed of light). Each mechanically driven mirror should be adjusted to maximize the heterodyne beat amplitude at c/l. In order to generate a servo control signal, each mechanically driven mirror can be dithered with a very small amplitude. Because of the coupling between small rings, the dither frequency for each small ring should be different and the detector for that ring should be tuned to the dither frequency. Even when only modes of the desired class lase, the amplitude of the output and/or circulating flux for each ring will be maximized when the length (l) is resonant with the lasing modes. FIG. 4 schematically illustrates an automatic path-length control system. A grating sampler 50 is used here to sample the flux in the feedback loop of a small laser, e.g., 12. The sampled output is reflected by a mirror 52 into a heterodyne detector 54 the output of which is fed to a control system 56. The output of the control system 56 is a control signal which is fed to a mirror actuation device 58, e.g., a piston, which moves to control the position of a dither mirror 36. The position of the dither mirror 36 is altered by the control signal through the piston 58 in such a way as to maximize the c/l signal through the laser 12. Although only one path-length control system is shown, it is to be understood that each small laser will have its own path-length control system. FIG. 5 shows, in block form, the schematic for an embodiment which may be employed as the control system unit 56. The output from the heterodyne detector 54 is passed through a bandpass filter 60 tuned to pass only the c/l frequency. If l is 5 meters, c/l may be about 60 MHz and the filter passband may, for example, range between 50 and 100 MHz, or 25 and 75 MHz. The output of the filter 60 is fed to a coherent phase-locked detector 64, which may, for example, be a Foster-Seeley detector with an appropriate filter. An AC signal is also fed to the coherent detector 64 from a dither generator 62. The dither frequency may, for example, be 2-20 KHz. The output of the detector 64 is a DC signal which comprises either the sum or difference of its inputs, according to the passband of its filter. The DC output of the coherent detector 64 and the AC dither signal are fed to a summer circuit 66 which feeds the sum of the two signals to the dither mirror actuator 58. The dither mirror 36 is then positioned in accordance with the DC level of the signal and dithered in accordance with the frequency of the AC dither signal. Several other tuned resonant circuits may be used to restrict laser action in the large ring to a single desired classes of modes. One of these resonant circuits is the embodiment 40 shown in FIG. 3. The large ring has a feedback loop of length (Nl). If a secondary feedback loop is introduced bypassing one of the small laser modules, e.g., 48, it will have a feedback loop length (N-1)l. It is known that this enhances every Nth mode relative to the other modes. With this single feedback bypass, the feedback loops of the small ring lasers of FIG. 1 can be eliminated. If more precision is required, one or more other bypass loops may be employed. FIG. 3 shows the two feedback loops previously described. Different feedback loops could be used; for example, the second loop could extend from the output of laser 2 (44) to the input of laser 1 (42). Also, more than two feedback loops could be used. Another way of defining the conditions under which the desired type of lasing occurs is to say that: (a) the difference between any two feedback lengths must be equal to l (e.g., the series loop has a length Nl and a second feedback path is formed from the output of the (N-1)th laser module to the input of the series loop); or (b) a single feedback path length must be equal to l (e.g., in FIG. 1, only laser 1 has a feedback path). In both cases, of course, the length of a path of the series loop must still be Nl. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. What is claimed and desired to be secured by Letters Patent of the United States is: 1. A laser with multiple phased outputs comprising:a plurality of laser modules of number (N) arranged serially to form a large ring, the output of the last laser module in the series being fed back as the input to the first module, the laser modules all having substantially identical beam path length (l) and the beam path length of the large ring being substantially equal to an integral multiple of the module beam path length, said large ring having at least one other feedback path than that extending from the output of the last module in the series to the input of the first module in the series. 2. A laser as in claim 1, wherein:each laser module comprises a feedback ring laser. 3. A laser as in claim 1, wherein:a portion of the output of the (N-1) laser module is also fed back to the input of the first module. 4. A laser as in claim 1, wherein:a portion of the output of each of several modules is fed back to the input of the first module. 5. A laser as in claim 1, wherein:said other feedback path extends from the output of the (N-1) th laser module to the input of the first laser module in the series. 6. A laser with multiple phased outputs comprising:a plurality of laser modules of number (N) arranged serially to form a large ring, the output of the last laser module in the series being fed back as input to the first module, the beam path length (l) of all laser modules being equal, a portion of the output of each module being removed from the series loop, the laser loop conforming to the equation ##EQU7## where l is the laser path length of laser module,λk is the wavelength of the oscillatory mode which results from the particular value of K under consideration, k is an integer, n is a number representing a mode of oscillation and can be equal to 0 or N, N is the number of laser modules in the large ring, and K is an integer such that a light wave travelling around the large ring reproduces itself after each round trip; and means for forcing the value of n to be either 0 or N. 7. A laser as in claim 6, wherein:said forcing means comprises a second feedback path within said large ring. 8. A laser with multiple phased outputs comprising:a plurality of laser modules of number (N) arranged to form a large ring, the output of the last laser module in the series being fed back as the input to the first module, the laser modules all having substantially the same beam path lengths (l) and the beam path length of the large ring being substantially equal to an integral multiple of the module beam path length, said large ring of laser modules having at least one other feedback path than that extending from the output of the last module in the series to the input of the first module in the series, the difference between any two feedback path lengths being equal to the beam path length (l) of an individual laser module. 9. A laser with multiple phased outputs comprising:a plurality of laser modules of number (N) arranged to form a large ring, the output of the last laser module in the series being fed back as the input to the first module, the laser modules all having substantially the same beam path lengths (l) and the beam path length of the large ring being substantially equal to an integral multiple of the module beam path length, said large ring of laser modules having at least one other feedback path than that extending from the output of the last module in the series to the input of the first module in the series, the length of any single feedback path except that from the output to the input of the large ring being equal to the beam path length (l) of an individual laser module.

1984-06-04

en

1997-05-20

US-1331379-A

Cooling and heating system utilizing solar heat ABSTRACT A cooling and heating system utilizing solar heat comprises a heat collector for heating a circulating heat medium with solar heat, an absorption refrigerator operable with the heat medium heated by the heat collector and serving as a generating heat source to provide a chilled medium, and an air-conditioning unit for circulating the chilled medium or the heated medium alternatively therethrough to cool or heat the space to be air-conditioned. The system further comprises a bypass line provided with an auxiliary refrigerator of the dual-effect type and connected to an intermediate portion of a line extending from the absorption refrigerator to the air-conditioning unit for supplying chilled medium or the heated medium to the unit. Change-over means is provided for passing the chilled medium or the heated medium through the bypass line. BACKGROUND OF THE INVENTION The present invention relates to a cooling and heating system utilizing solar heat and comprising a heat collector for heating a circulating heat medium with solar heat, an absorption refrigerator operable with the heat medium heated by the heat collector and serving as a generating heat source to provide a chilled medium, and an air-conditioning unit for circulating the chilled medium or the heated medium alternatively therethrough to cool or heat the space to be air-conditioned. Conventional cooling and heating systems of this type mainly resort to the use of the solar heat collected by a heat collector and serving as a cooling and heating energy source and therefore have the following problems: (1) Although the air-conditioning load varies greatly throughout the year, the heat collector as well as the refrigerator must have a considerably large capacity adapted for the maximum load during the year. (2) When the air-conditioning load is small, accordingly, the heat collector and the refrigerator are unable to exhibit their abilities to the greatest possible extent, invariably failing to permit the system to achieve a high thermal efficiency all the year round. (3) Consequently there arises the necessity of using a heat accumulator of fairly large capacity for storing the excess of heat when the air-conditioning load is small despite sufficient sunshine. (4) There is the inherent requirement that the heat medium for operating the refrigerator must have a temperature of at least about 82° C. Additionally an absorption refrigerator, if used for the system, must be fully operable with solar heat to provide a chilled medium at an optimum temperature of about 7 to about 8° C. as requied for air conditioning. The heat medium needs then to have a considerably high temperature of at least about 88° C. Thus when the heat collector is unable to give the desired amount of heat medium owing to insufficient sunshine, there arises a need to use an auxiliary heat source in addition to solar heat. Further when no sunshine is available, the refrigerator must be operated solely with the auxiliary heat source. The refrigerator nevertheless is inherently as low as about 0.65 to about 0.68 in coefficient of performance (C.O.P.) and therefore necessitates a fairly large auxiliary heat source, which renders the refrigerator very inefficient to operate. Accordingly the conventional systems are not fully satisfactory in overall thermal efficiency, require a high running cost and involve the problem that the relatively great investment in equipment is not completely repayable. SUMMARY OF THE INVENTION A first object of this invention is to overcome the foregoing problems and to provide a cooling and heating system utilizing solar heat, comprising components such as a heat collector, refrigerator, auxiliary heat source and heat accumulator which are made compact to the greatest possible extent, and adapted to achieve an improved overall thermal efficiency, the system thereby being rendered satisfactorily operable with high stability at all times and at low initial and running costs. To fulfill this object, the refrigerator is of the absorption type operable with a heat medium heated by the heat collector to provide a chilled medium. The cooling and heating system of the invention is characterized in that a bypass line provided with an auxiliary refrigerator of the dual-effect type is connected to an intermediate portion of a line extending from the absorption refrigerator to an air-conditioning unit for supplying the chilled medium or heated medium to the unit, change-over means being provided for passing the chilled medium or the heated medium through the bypass line. Usable as the dual-effect auxiliary refrigerator is a gas-burning absorption refrigerator relatively simple in construction and having a high C.O.P. (0.95 for cooling or 0.8-0.9 for heating). The system described operates with solar heat alone without operating the auxiliary refrigerator when sufficient sunshine is available for the air-conditioning load. Further when the sunshine is insufficient relative to the air-conditioning load, the system operates utilizing the solar heat to the greatest possible extent with the deficiency compensated for by the auxiliary refrigerator having a high thermal efficiency. The efficient auxiliary refrigerator affords the desired operation when no sunshine is available. Thus the system provides suitable cooling or heating with stability and high efficiency at all time, achieving greatly improved thermal efficiency and performance in its entirety when evaluated on a year-round basis. Since the auxiliary refrigerator operates at any time to compensate for the deficiency of the solar heat available for the air-conditioning load, the heat collector, main refrigerator and auxiliary heat source need not always be large enough to accommodate the maximum air-conditioning load throughout the year but can be compacted to the greatest possible extent. This further permits the use of a heat accumulator of reduced capacity. The system therefore assures savings in running cost, renders the equipment investment repayable within a relatively short period and is extremely economical. A second object of this invention is to provide a cooling and heating system utilizing solar heat and adapted for use with a plurality of spaces to be air-conditioned between which there is a considerable difference in load as in the case of two buildings positioned relatively close to each other or of a large building which is exposed to sufficient sunshine at one portion while only insufficient sunshine is available at another portion, the system being such that these spaces, involving varying loads, can be cooled or heated individually suitably with economy and with a very high overall efficiency even when the system is used singly. To fulfill this object, the cooling and heating system of the invention having the foregoing construction further comprises a first branch line extending from the supplying line and adapted to be placed into or out of use by change-over, a second branch line extending from the bypass line and adapted to be placed into or out of use by change-over, and a further air-conditioning unit having the two branch lines arranged in parallel therein for another space to be air-conditioned. According to the arrangement described above, the two branch lines can be suitably selectively brought into or out of use respectively in accordance with the differing air-conditioning loads of the spaces to be air-conditioned, so that these spaces, although different in air-conditioning loads, can be cooled or heated individually suitably by the single system with economy and very high efficiency. Other objects and benefits of the invention will become apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a first embodiment of the cooling and heating system of this invention utilizing solar heat; and FIG. 2 is a diagram showing a second embodiment thereof. DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the invention will be described with reference to FIG. 1. A solar heat collector 1 connected to a heat accumulator 2 via a pump P1 includes a group of parallel collector panels arranged therein for collecting solar heat. The collected heat is given to water or like heat medium circulated by the pump P1 to heat the medium. The heated medium is stored in the heat accumulator 2 at a high temperature. The heat accumulator 2 is connected to the generator 4a of an absorption refrigerator 4, about 0.6 to about 0.7 in C.O.P. (coefficient of performance), by a heated medium circulating line 3 provided with a pump P1 at an intermediate portion thereof. The refrigerator 4 has a condenser 4c connected via a pump P3 to a cooling tower 5 and an evaporator 4b connected to fan coil units or like air-conditioning units 6 disposed in the space S to be air-conditioned, by a supply line 7 provided with a pump P4 at an intermediate portion thereof for circulating an air-conditioning fluid. Heated medium bypass lines 8 bypassing the refrigerator 4 interconnect the forward passages of the lines 3 and 7 and also the return passages thereof. Change-over valves V1 are provided at the four junctions a1, a2, a3 and a4 between the bypass lines 8 and the two lines 3 and 7. Thus when the change-over valves V1 are operated to bring the bypass lines 8 into conduction, the hot water or like heated medium from the heat accumulator 2 is bypassed around the refrigerator 4 and flows directly through the line 7 for heating. Alternatively when the change-over valves V1 are operated otherwise to bring the line 3 into communication with the generator 4a, and the evaporator 4b with the line 7, the refrigerator 4 operates with the heated medium supplied from the heat accumulator 2 and serving as its generating heat source, providing chilled water or like medium which circulates through the line 7 for cooling. In this way, the system is made operable alternatively for heating or cooling by the change-over of the valves V1. Change-over valves V2 each in the form of a three-way valve are disposed at two portions a5 and a6 of the forward passage of the supply line 7 between the refrigerator 4 and the air conditioning units 6. A line 11 bypassing the line 7 extends from one valve V2 to the other valve V2. The change-over valve V2 at the portion a6 is rendered serviceable also as a mixing valve. The bypass line 11 is provided with a dual-effect auxiliary refrigerator 10 which operates for cooling or heating alternatively on change-over. The auxiliary refrigerator 10 is of the gas-burning absorption type and has a C.O.P. of about 0.95 for cooling or of about 0.8 to about 0.9 for heating. A header 9 is provided between the bypass line 11 and the return passage of the supply line 7. The forward passage of the supply line 7 is provided, between the portions a2 and a5, with a temperature sensor 12 for detecting the temperature of the chilled or heated medium therebetween. Change-over means 13 provided for the two change-over valves V2 is electrically connected to the temperature sensor 12 to automatically operate the valves V2 in accordance with the temperature detected by the sensor 12 so that the chilled medium or heated medium, after passing through the change-over valve V1 at the portion a2, will be circulated through the line 7 or alternatively bypassed through the line 11. The temperature settings for effecting the change-over based on the detected temperature are variable as desired in accordance with cooling or heating and the air-conditioning load, etc. With the present embodiment, the change-over temperature for cooling is set at about 9 to about 10° C., and that for heating at about 49 to about 50°C. Stated more specifically, the change-over valves V2 during cooling are automatically changed-over to pass the chilled medium from the refrigerator 4 through the line 7 if the temperature thereof detected by the sensor 12 is lower than 8 to 9° C. or to bypass the same through the line 11 if the detected temperature is higher than 9 to 10° C. During heating, the change-over valves V2 are automatically changed-over to pass the heated medium from the heat accumulator 2 through the line 7 if the temperature thereof detected by the sensor 12 is higher than 50 to 51° C. or to bypass the same through the line 11 if the detected temperature is lower than 49 to 50° C. The change-over valve V2 at the portion a6 is openable at two inlets at the same time so as to be serviceable as a mixing valve as already stated. Accordingly even when the valves V2 are open for the line 7, the auxiliary refrigerator 10 can be operated at the same time to cause the medium through the line 11 to be thereby heated or chilled and mixed at the portion a6 with the heated or chilled medium through the line 7. Indicated at 14 is an auxiliary boiler serving as an auxiliary heat source and connected in parallel with the heated medium circulating line 3 via a three-way valve V3, at 15 a pressure adjusting tank useful when the circulating line 3 is held closed, and at 16 a hot water supply circuit. The cooling and heating system utilizing solar heat and having the construction described above will operate in the following manner, for example, for cooling during summer. (i) When sufficient sunshine is available, permitting the heat accumulator 2 to maintain the heat medium at about 85° C. and the refrigerator 4 to supply the chilled medium at about 8 to about 9° C., and the load on the air-conditioning units 6 is not greater than can be accommodated by the refrigerator 4, the change-over valves V2 automatically maintain the supply line 7 in a conductive state. Consequently the chilled medium from the refrigerator 4 alone is passed through the air-conditioning units 6 to cool the space S only with the solar heat. When the load on the air-conditioning units 6 has exceeded the capacity of the refrigerator 4, the auxiliary refrigerator 10 functions, causing the resulting chilled medium to be mixed, by the change-over valve V2 at the portion a6, with the medium from the refrigerator 4. (ii) When a lesser amount of sunshine is available, resulting in a reduction in the temperature of the heat medium in the accumulator 2 and an increase in the temperature of the chilled medium from the refrigerator 4 to about 10 to about 11° C., the sensor 12 detects this, automatically operating the change-over valves V2 to bring the bypass line 11 alone into conduction. The chilled medium supplied at about 10 to about 11° C. from the refrigerator 4 is mixed at the header 9 with part of the cooling medium returning at about 13 to 14° C. from the air-conditioning units 6, thus precooling the returning medium by an amount corresponding to the mixing ratio (i.e. to about 12 to about 13° C.). The mixture is then chilled to 7 to 8° C. by the auxiliary refrigerator having a high C.O.P. and thereafter fed to the air-conditioning units 6. (When the flow through the refrigerator 4 is small, the returning cooling medium from the air-conditioning units 6 may be wholly returned to the auxiliary refrigerator 10 via the header 9 even if the chilled medium has a temperature of 8 to 9° C.) (iii) When no sunshine is available with the air-conditioning load at a relatively low level, the auxiliary refrigerator 10 alone is operated for air conditioning. (iv) When there is no sunshine available with the air-conditioning load exceeding the capacity of the auxiliary refrigerator 10, the three-way valve V3 is changed-over, and the auxiliary boiler 14 serving as an auxiliary heat source is operated to bring the circuit into the state of (i) or (ii) above and effect air conditioning by both the refrigerators 4 and 10. The operation of the system during winter for heating will be apparent from the above description of the summer-time cooling operation. when there is not a great necessity for heating, the auxiliary refrigerator 10 may be one adapted solely for refrigeration. FIG. 2 shows another embodiment of the cooling and heating system utilizing solar heat according to this invention and adapted for use with a plurality of spaces to be air-conditioned between which there is a difference in air-conditioning load, such that even when used singly, the embodiment is capable of cooling and heating the spaces individually suitably with high efficiency. This embodiment will be described below, but the same parts as included in the first embodiment will not be described. Change-over valves V4, each in the form of a three-way valve and openable at two outlets or inlets at the same time, are disposed at a location between the portion a2 and the temperature sensor 12 and another location between the pump P4 and the portion a3. By way of the change-over valves V4, a first branch line 17 extends from the supply line 7. The branch line 17 is provided with a pump P5 and a heat exchanger 17a. Provided between the auxiliary rerigerator 10 and the portion a6 is a change-over valve V5 comprising a three-way valve openable at two outlets at the same time. By way of the header 9 and the change-over valve V5, a second branch line 18 extends from the bypass line 11. The branch line 18 has a pump P6 and a heat exchanger 18a. An air-conditioning unit 19 of the duct type having the heat exchangers 17a and 18a arranged in parallel therein is provided for the space S', different from the space S, to be air-conditioned. Three-way valves V6 openable at two outlets and two inlets respectively are mounted on intermediate portions of the second branch line 18. Via the two valves V6, a third branch line 49 extends from the second branch line 18. The third branch line 49 serves to efficiently air-condition the space S'. The system of the above construction can be changed over from one state to another for operation in various modes in accordance with the amount of solar heat collected, the load involved in each of the spaces S and S', etc. For instance, when sufficient solar heat is available with a great load involved in the space S and a small load in the space S', the two lines 7 and 11 are used for the air-conditioning units 6 to air-condition the space S with the collected solar heat and by the auxiliary refrigerator 10, while the line 17 alone is used for the air-conditioning unit 19 to air-condition the space S' with the solar heat only. In this case, the change-over valves V4 are opened at the two outlets and inlets at the same time respectively, whereas the change-over valve V5 is opened for the line 11 and closed for the line 18. The change-over valves V2 are automatically operated by the change-over means 13 in accordance with the temperature detected by the sensor 12. The change-over valves will be operated suitably for the other modes of operation in accordance with the amount of solar heat available, the loads involved in the spaces S and S', the sizes thereof and other conditions concerned. We claim: 1. In a cooling and heating system utilizing solar heat comprising:a solar heat collector (1), a heat accumulator (2) for storing fluid heated by solar heat obtained by said solar heat collector (1), a single-effect absorption type refrigerator (4) connected to said heat accumulator (2) via heated fluid circulating lines (3), and actuated by said heated fluid supplied from said heat accumulator (2) to produce chilled fluid, at least one air-conditioning unit (6) connected to said single-effect absorption type refrigerator (4) via air-conditioning fluid circulating lines (7), and adapted to cool or heat space (S) to be air-conditioned, heated fluid bypass lines (8) provided between said heated fluid circulating lines (3) and said air-conditioning fluid circulating lines (7) to bypass said single-effect absorption type refrigerator (4), and change-over valves (V1) provided at junctions (a1), (a2), (a3), (a4) of said heated fluid bypass lines (8) to said heated fluid circulating lines (7), and adapted to selectively changeover between a heating state to supply said heated fluid from said heat accumulator (2) directly to said air-conditioning unit (6) and a cooling state to supply said heated fluid from said heat accumulator (2) to said single-effect absorption type refrigerator (4) and supply the chilled fluid generated by the single-effect absorption type refrigerator (4) to said air-conditioning unit (6), the improvement comprising: a further bypass line (11) connected in parallel to an intermediate portion of a forward passage of said air-conditioning fluid circulating lines (7), change-over valves (V2) provided at junctions (a5), (a6) of said further bypass line (11) to said forward passage of said air-conditioning fluid circulating lines (7) and adapted to selectively changeover between a state to bypass and a state not to bypass said heated or chilled fluid from said forward passage of said air-conditioning fluid (7) to said further bypass line (11), and an auxiliary gas-burning double-effect absorption type refrigerator (10) provided on an intermediate portion of said further bypass line (11) to further heat or chill the heated or chilled fluid supplied from said forward passage of said air-conditioning circulating lines (7). 2. A cooling and heating system as claimed in claim 1, wherein a header (9) is provided between the bypass line (11) and a return passage portion of the supplying line (7). 3. A cooling and heating system as claimed in claim 1, wherein the change-over means (13) is automatically operable for change-over in accordance with the temperature detected by a temperature sensor (12) disposed upstream from the change-over means (13). 4. A cooling and heating system as claimed in claim 3, wherein the air-conditioning unit (6) is a fan coil unit. 5. A cooling and heating system as claimed in claim 2, further comprising a first branch line (17) extending from the supplying line (7) and adapted to be placed into or out of use by change-over, a second branch line (18) extending from the bypass line (11) and adapted to be placed into or out of use by change-over, and a further air-conditioning unit (19) having the two branch lines arranged in parallel therein for another space (S') to be air-conditioned. 6. A cooling and heating system as claimed in claim 5, wherein the further air-conditioning unit (19) is of the duct type.

1979-02-21

en

1981-05-26

US-6387093-A

Phenanthridium dye staining of nucleic acids in living cells ABSTRACT The invention relates to use of fluorescent compounds of the formula: ##STR1## where R contains between 4 and about 10 carbons and is optionally saturated or unsaturated, and is linear or branched or contains an alicyclic or aromatic ring; and the symbol Ψ depicts the presence of the counterion used to neutralize the positive charge on the dye. The fluorescent dye dissolved in a biologically compatible solution stains a wide variety of living cells with a red nucleic acid stain after brief incubation in low concentrations of dye, without the requirement of permeabilizing reagents. Detection of the fluorescence can be used alone or in combination with measurement of other markers or properties of the cells to identify, discriminate or sort viable cells. FIELD OF THE INVENTION The invention relates to a method of staining nucleic acids in living cells using phenanthridium dyes. In particular, the invention relates to 5-substituted derivatives of 3,8-diamino-6-phenylphenanthridium that are permanent to living cells under physiological conditions. BACKGROUND INFORMATION Fluorescent dyes are known to be particularly suitable for biological applications in which a highly sensitive detection method is desirable. By binding to a specific biological ingredient in a sample, a fluorescent dye can be used to indicate the presence or the quantity of the specific ingredient in a sample. A variety of fluorescent dyes are commercially available for specific fluorescent staining and quantitation of DNA and RNA, and other applications involving nucleic acids, see e.g. Haugland, HANDBOOK OF FLUORESCENT PROBES AND RESEARCH CHEMICALS, Set 31 (5th Ed. 1992, Molecular Probes, Inc., Eugene, Oreg.) (incorporated by reference). Among these are derivatives of 5-substituted-3,8-diamino-6-phenylphenanthridium (5-DAPP): ##STR2## When R is ethyl, the dye is commonly called ethidium. When it is methyl, the dye is methidium. If R is 3-(N,N-diethyl-N-methylammonium)propyl, the dye is propidium. Various other analogs of 5-DAPP are known, including symmetric or asymmetric dimeric derivatives, derivatives in which the position(s) of the amino groups are changed or the amino groups are further modified by chemical substitution or omission and derivatives in which the aryl moiety is replaced by modified aryl, alkyl, arylalkyl or heteroaryl groups or by hydrogen. Ethidium and its analogs were originally studied in the early 1940's as therapeutic agents for treatment of trypanosomiasis. They were subsequently found to bind to nucleic acids. This binding can be detected by the change in fluorescence properties of the nucleic acid complex following dye binding. When bound to nucleic acids, the 5-DAPP dyes generally have desirable fluorescence spectral properties. In particular, they absorb light at 488 nm and 514 nm, making them useful with instrumentation that uses the argon laser as an excitation source, such as flow cytometers and laser scanning microscopes. Furthermore, the fluorescence emission of the 5-DAPP dyes has a Stokes shift that is sufficient to permit detection of their fluorescence usually at a wavelength beyond about 580 nm, so that cellular autofluorescence is reduced. This characteristic also makes a 5-DAPP dye useful for multicolor applications in conjunction with a second dye, such as fluorescein or one of its conjugates, that is excited by the same source, but whose fluorescence is optimally detected at a shorter wavelength (typically at less than about 540 nm). Not all nucleic acid stains can be used with living cells. To be useful for the analysis of nucleic acids in living cells, a detection reagent must be able to enter living cells and to respond to the presence of nucleic acids. It is particularly important to be able to stain nucleic acids in viable cells if it is desired to analyze and, if needed, sort viable cells according to the nucleic acid content or proliferative state of these cells based on their fluorescence. It is furthermore of importance to retain the cell viability if one wishes to sort and clone cells based on some additional fluorescence parameter. It is generally recognized that ethidium and its analogs are usually not suitable for staining of nucleic acids in living cells in which the cell membrane is intact, except for permeabilized cells or at very high dye concentrations. Consequently several of these probes, in particular ethidium bromide (Tanke, et al., J. IMMUNOL. METH. 52, 91 (1982)), propidium iodide (U.S. Pat. No. 5,057,413 to Terstappen et al. Oct. 15, 1991 U.S. Pat. No. 5,314,805) and ethidium homodimer (Live/Dead® kit, U.S. Ser. No. 07/783,182 to Haugland, et al., filed Oct. 26, 1991) U.S. Pat. No. 5,314,805, have been used extensively to detect and quantitate cells in which the membrane is compromised or missing, i.e. dead cells. Making the 5-DAPP dyes more useful for staining nucleic acids in a wide variety of living cells requires improving access of the dyes to intracellular nucleic acids. Although numerous methods for enhancing permeability of organic compounds into cells have been described, including chemical- or electro-permeabilization, scrape loading, use of detergents, microinjection or various means of mechanical disruption, all of these methods intrinsically have the potential disadvantage of altering the properties of the cell membrane and thus the cell's intrinsic properties or proliferative capacity. Furthermore it is often difficult to achieve uniform labeling or reproducibility using these methods and some of the methods such as microinjection are not technically feasible on very small or fragile cells. One method for improving the uptake of ethidium into living cells involves the chemical reduction of ethidium bromide to a dihydrophenanthridine derivative with no positive charge, see e.g. Bucana, et al., J. HISTOCHEM. & CYTOCHEM. 34, 1109 (1986). Unlike ethidium or the subject materials, this compound does not bind to nucleic acids and requires the secondary step of intracellular oxidation to regenerate ethidium intracellularly. Although the ultimate result in certain types of living cells is nuclear staining by a 5-DAPP derivative, not all cells are capable of oxidizing this type of dihydrophenanthridine to the nucleic acid stain. This invention describes an effective means for improving uptake and staining of certain 3,8-diaminophenanthridium dyes in a wide variety of viable cells in culture or tissues by slightly increasing the size of the quaternizing substituent at the 5-position of the phenanthridine ring and thereby increasing the lipophilicity of the probe. Although only a slight chemical modification, this change significantly improves the permeability of the dye through the membrane of living cells and thus the staining of viable cells without significantly altering the ability of the dye to stain nucleic acids and without appreciably altering the spectral properties of the complex. There is an optimal size of the quaternizing substituent in that a further increase in size of the substituent has a deleterious effect on the nucleic acid staining by the dye. These reagents enable the staining of nucleic acids in living cells by a simple incubation with the reagent in standard culture medium, or in vivo by injection in a suitable biologically compatible fluid such as saline without resorting to use of harsh additives. Furthermore, use of these reagents permits detection, analysis and, if required, sorting of the viable cells based on the fluorescence intensity of their complex with nucleic acids, or based on fluorescence polarization, excited state fluorescence lifetime, or other dye-nucleic acid complex-related optical properties. The subject dyes have the same basic 5-DAPP structure as does ethidium, except that instead of the two-carbon alkyl group as in ethidium, the substituent R at the 5-position of the phenanthridium ring contains 4 or more carbon atoms. Synthesis of a few examples of 5-DAPP molecules for use as drugs has been described in earlier publications, e.g. Watkins, J. CHEM SOC. 3059 (1952) (incorporated by reference). This paper and a related paper, Watkins & Woolfe, NATURE 169, 506 (1952) compare the use of various derivatives of 5-DAPP as trypanocides and conclude that the therapeutic potential of ethidium is superior to that of other 5-DAPP derivatives with longer alkyl chains. The Watkins paper speculates that the concentration of the free-base form of ethidium at pH 6-9 is greater than that of methidium (which is shown to be less effective than ethidium) and that this property may result in an increased rate of diffusion of the ethidium versus methidium across the cell membrane into the trypanosome cytoplasm. Watkins does not, however, indicate that other less effective 5-DAPP derivatives would diffuse across the cell membrane more quickly than ethidium or that they would be useful as fluorescent detection reagents for nucleic acids in living cells. A application Ser. No. 08/047,683, abandoned (incorporated by reference) describes the use of the subject dyes to distinguish between live gram-positive and live gram-negative bacteria. Although dyes such as hexidium also lightly stain some gram negative organisms when used alone, the staining of gram-positive cells is significantly greater. This discrimination is not possible with ethidium, which does not effectively stain either live gram negative or live gram positive bacteria under the same mild conditions. DESCRIPTION OF THE DRAWINGS FIG. 1. Relative Uptake of Dyes into Living Cells. Uptake of ethidium, butidium, hexidium and octidium by Bacillus cereus as described in Example 2. SUMMARY OF THE INVENTION, INCLUDING PREFERRED EMBODIMENTS This invention describes a method of staining nucleic acids in living cells under physiological conditions with a dye that is excitable at about 488 nm and about 514 nm or in the range of about 480 to 520 nm and emits detectable fluorescence at a wavelength greater than about 540 nm. The method involves the use of a biologically compatible staining solution comprising a dye of the formula (5-DAPP/LIVE): ##STR3## where the substituent R contains from 4 to about 10 carbons and the symbol Ψ depicts the presence of the counterion used to neutralize the positive charge on the dye. Preferably R contains between 4 and 8 carbons and is optionally saturated or unsaturated, and is linear or branched or contains an alicyclic or aromatic ring. For example, R is a saturated or unsaturated butyl, pentyl, hexyl, heptyl or octyl substituent that is optionally branched, or R is phenalkyl or alkyl substituted phenalkyl, or R contains a cyclohexyl, cyclopentyl, cyclobutyl or cyclopropyl ring. When R is unsaturated it contains 1 to 4 carbon-carbon double or triple bonds in any combination. In one aspect of the invention, R contains less than about 11 carbons and contains a cyclic structure that is aromatic or alicyclic, such as a 6-membered ring. Preferably R is saturated n-butyl, n-pentyl, n-hexyl, n-heptyl or n-octyl, of which n-hexyl is preferred for most detection assays. When R is n-butyl, the dye is termed here "butidium"; when R is n-pentyl the dye is termed "pentidium"; when R is n-hexyl the dye is termed "hexidium"; when R is n-heptyl the dye is termed "heptidium"; when R is n-octyl the dye is termed "octidium"; and when R is phenethyl (C6 H5 CH2 CH2 --) the dye is termed "phenethidium." Synthesis and characterization of butidium and hexidium is described in Watkins. This method is also generally useful for preparing compounds where the quaternizing substituent contains a cyclic structure. In general, the substituent R is incorporated into the 5-DAPP/LIVE reagent by reaction of a suitably amine-protected 3,8-diamino-6-phenylphenanthridine with an alkylating agent R--X wherein X is a "leaving group" that activates the alkyl portion of the reagent to nucleophilic displacement. Usually the protecting group is ethoxycarbonyl and R is the desired 5-DAPP/LIVE substituent, i.e. a saturated or unsaturated, linear or branched alkyl chain or contains an aromatic or alicyclic ring. Other amine-protecting groups such as carbobenzyloxy that prevent or reduce reaction of the alkylating reagent with the amines of the phenanthriduim are also suitable. Typically, the leaving group X from the alkylating agent provides the required counterion Ψ for the dye, which is a halogen (preferably iodide or bromide) or a sulfonate ester (preferably p-toluenesulfonate, p-chlorobenzenesulfonate or trifluoromethanesulfonate). Other counterions Ψ such as perchlorate, phosphate, sulfate, carbonate, bicarbonate, or tetrafluoroborate or anions of an organic carboxylic acid or sulfonic acid with less than about 8 carbon atoms are typically obtained by ion exchange subsequent to alkylation and deprotection. Variants of 5-DAPP dyes in which the 6-phenyl moiety is further substituted or replaced by other aromatic, heteroaromatic, aliphatic substituents or in which the amino groups are modified or missing are known e.g. Watkins, supra; Walls, J. CHEM SOC. 294 (1945). Equivalent versions of these prepared with the same R substituent from suitably protected intermediates enhances their membrane permeability. Usually these modified versions of the 5-DAPP dyes do not provide additional benefits and they usually require greater effort for their synthesis. Variations on methods for synthesis of the subject dyes or for incorporating additional non-carbon or non-hydrogen atoms into R or at other sites on the molecule are well documented in the literature or are obvious to one skilled in the art, and result in equivalent compounds. The biologically compatible staining solution is made by dissolving the dye directly in an aqueous solvent such as water or tissue culture medium or buffer such as phosphate buffered saline, or, more commonly, by dissolution in an organic water-miscible solvent such as dimethylsulfoxide (DMSO), dimethylformamide (DMF), or a lower alcohol such as methanol or ethanol followed by dilution with an aqueous solvent to a concentration of solvent that is biologically compatible with the cells (i.e. not detrimental to the continuing integrity of the cell membrane). Typically the dye is preliminarily dissolved in an organic solvent (preferably DMSO) at a concentration of greater than about 1000-times that used in the staining medium then diluted one or more times into an aqueous medium such as water or a buffer to give a staining solution where the dye is present at a concentration at least sufficient to give a detectable fluorescent signal inside the cells. The staining solution optionally contains additional dyes, such as stains to detect cell viability or fluorescent conjugates of antibodies, avidins, protein A, protein G, or lectins to aid in classification of cell type; nutrients, growth factors, or chelators and preferably does not contain extracellular nucleic acids that may result in background staining or consumption of the staining reagent. Reagents or conditions that temporarily enhance the permeability of materials into cells such as hypotonic medium or detergents may be present if they do not significantly interfere with the biological compatibility of the solution, but are usually not necessary. Preferably the staining solution is completely used within one day and a new staining solution is subsequently prepared. The optimal concentration of dye in the staining solution depends on the type and concentration of cells in the sample, the type of sample, and the dye itself. The optimal concentration is usually that concentration that results in the optimum fluorescent brightness per cell in the sample. To discriminate two or more types of cells in a mixed population of cells, however, the optimal concentration results in the greatest difference in staining or identifying the various types of cells or parts of cells of interest. In such cases, the optimal concentration does not necessarily yield the greatest intensity of fluorescence or fastest rate of staining. Optimization generally involves two successive steps: 1) determination of cell density, and 2) measurement of the intensity of fluorescence as a function of any variable to be tested such as different dyes, differing dye concentrations, time, temperature, additives to the medium, type of cells or other variables. Analysis of the staining of suspended cells can be conducted either in bulk (e.g. Example 1) using an apparatus such as a fluorometer or a fluorescence plate reader or in an apparatus capable of detecting the staining in single cells such as a flow cytometer (Example 3). The staining of adherent cells that cannot be suspended by trypsinization or other means or for tissues is preferably optimized by a visible observation of a field of cells, such as by viewing the stained cells under a microscope by eye or in conjunction with a solid state camera and imaging software. The optimal concentration of dye generally depends on the cell density. Bacterial cell density is typically determined from a series of absorption readings taken from a serial dilution of a suspension of cells compared with a duplicate plating of cells on an appropriate solid growth media. The serial dilutions of plated cells are counted and compared with the absorption measurements of the same serial dilutions to determine the relationship between the number of cells or cell forming units per milliliter (cfu/mL) and absorption (cfu/mL/abs). Preferably the readings are taken at cell suspension concentrations between about 1×103 cfu/mL and about 1×1010 cfu/mL, more preferably between about 1×105 cfu/mL and about 1×109 cfu/mL. Below about 103 cfu/mL, absorption readings are not very reliable. Alternatively, cell densities are determined by direct microscopic count using a standard hemocytometer (particularly for non-bacterial cells). Following determination-of cell density, a range of dye concentrations is then used to stain the cell suspensions at different cell densities to determine the optimal dye concentration for the cell density of the sample (Examples 1 and 3 ). Typically, dye concentrations from about 1 mM down are tested, preferably dye concentrations from about 30 μM down to about 1 μM. Preferably the 5-DAPP/LIVE dye is present at a concentration sufficient to give a bright red fluorescent emission (i.e. an emission maximum greater than about 540 nm). The concentration of the dye in the staining solution is typically less than about 1 mM; more typically 0.1 μM to 100 μM; most typically about 1 μM to about 30 μM. At very low concentrations of dye (less than about 0.1 μM), the cytosol of eucaryotic cells stains initially with a faint green fluorescence that is only detected with very sensitive instruments such as a microscope equipped with a low light level imaging detector such as an image intensified video camera or an integrating charge-coupled device. The amount of cytoplasmic staining can be limited somewhat by the use of chloroquine to inhibit lysosomal uptake as demonstrated in the pulse and chase technique in Example 10. The biologically compatible staining solution is combined with a sample containing the cells of interest. Depending on the type of sample and characteristics of the cell population thought to be contained in the sample, the sample is added to the staining solution or the staining solution is added to the sample. For example, a filter containing a retentate removed from a liquid sample can be placed in the aqueous dye solution, allowing the retentate to incubate in the dye solution. Alternatively, where the sample is placed on a slide or in a specialized container, the staining solution can be added to the slide or container before or after the addition of the sample. Usually the staining solution is added to the sample to provide for a relatively homogeneous contact of the sample with the dye for a predetermined length of time. In the case of tissue staining, however, it may not be possible to obtain the desired staining intensity, pattern or discrimination without resorting to a slow perfusion of the dye or topical application. The cells in the sample are optionally in suspension in a biologically compatible medium or are located on a solid or semisolid support. In one embodiment of the invention, the sample is in suspension on a microscope slide or in a specialized container needed for an instrumentation detection method such as in a cuvette or in a microtiter plate (e.g. 96 well titer plate). Alternatively, the cells in the sample are adhered to a microscope slide or coverslip by normal cellular adhesion or by using an artificial adhesive solution such as poly-L-lysine or are attached to a filter as a retained residue or retentate. Optionally, washing and resuspension of cells are used to further improve the fluorescent response by eliminating background fluorescence. The living cells in the sample can be obtained from a wide range of sources. In one aspect of the invention, the cells are pure cultures of eucaryotes or procaryotes. Alternatively, the cells are single cell organisms or individual cells or tissues. Similarly, suspensions of cells derived from mechanical/enzymatic dissociation of tissues, adherent tissue culture cells removed from a substrate with Versene, or normally non-adherent cells in culture can be prepared. Generally, the method most universally stains cells that do not have enveloping membranes or multiple layers of polysaccharide beyond the boundary of the plasma membrane. Preferred cells include individual differentiated nucleated animal cells from vertebrates or invertebrates; single-celled organisms such as protozoa; and gram-positive bacteria. Uniformity of staining may be of less concern where it is desired to discriminate between types of cells based on their dye uptake or to visualize staining patterns that may reflect differences in uptake of the dye, such as in tissues or whole organisms. Although the preferred dyes generally stain all types of living cells, including procaryotes and eucaryotes, plants, animals, fungi, and fungal spores, the dyes are also specifically excluded from certain types of cells. This characteristic allows the dyes to be used to distinguish certain cells from a mixed population of living cells, only some of which exclude the dyes in the method of the invention. Because the low concentrations of dye routinely used in the invention can sometimes give anomalous cytoplasmic staining or may be excluded from certain specific cell types, the optimization of dye and cell concentration, temperature, additives to the medium and changes in other conditions are especially important. To discriminate two or more types of cells in a mixed population of cells, as in samples of bodily fluids or tissue or testing for contamination, cells can be differentiated based on the intensity or rate of uptake of staining by a 5-DAPP/LIVE dye, optionally in combination with other parameters such as light scatter or intensity of a second dye, to select, quantitate or sort target cells in a mixture of similar or dissimilar cells (e.g. Examples 1,3 and 12). In one aspect of the invention, the 5-DAPP/LIVE dyes are used to identify specific cells in a mixture of blood cells, where there may be questions of both the identity and nucleic acid content of the cell. Alternatively, these dyes are used to discriminate cells by microscopy based on their morphology of staining, relative size or other characteristics in combination with some second parameter such as fluorescence of a second stain or light scattering, as in flow cytometry. Yet another alternative is to use a second fluorescent reagent that is added to the sample, for example, a fluorescent reagent such as fluorescently labeled protein that binds preferentially to cells of interest thought to be contained in the sample (e.g. Example 12). Typically, it is important to determine which cells in a potentially mixed population of cells are live and which cells are not alive. This is generally done using a second fluorescent dye that is impermeant to living cells, but that stains nucleic acids in a color that contrasts to the generally red color of the 5-DAPP/LIVE dyes (e.g. Examples 1 and 3). If such a measurement is not made, then the relatively rapid staining of dead cells by the 5-DAPP/LIVE dye can potentially be confused with uptake of the 5-DAPP/LIVE dye by live cells. This is particularly necessary where an intensity measurement of cells is made in bulk without observing the fluorescence of single cells or in tissues where there may be several dead cells proximal to where the tissue has been cut. Suitable dyes for such discrimination are generally nucleic acid stains that are impermeant to live cells and are relatively non-fluorescent when not bound to nucleic acids. Preferably the impermeant stains can be excited at the same or nearly the same wavelength as the 5-DAPP/LIVE dye, but have green or yellow-green fluorescence when bound to the nucleic acid. A variety of suitable dyes are described by pending applications for DIMERS OF UNSYMMETRICAL CYANINE DYES (Ser. No. 07/761,177 filed Sep. 16, 1991 by Yue et al., abandoned), UNSYMMETRICAL CYANINE DYES WITH CATIONIC SIDE CHAIN (Ser. No. 07/833,006 filed Feb. 8, 1992 by Yue, et al., U.S. Pat. No. 5,321,130), and DIMERS OF UNSYMMETRICAL CYANINE DYES CONTAINING PYRIDINIUM MOIETIES (Ser. No. 08/043,665 filed Apr. 5, 1993 by Yue et al.) (all three patent applications incorporated by reference). Examples of suitable dyes with contrasting blue, blue-green, green, yellow-green or yellow fluorescence include dyes commercially available from Molecular Probes, Inc., Eugene, OR under the trademarks PO-PRO-1, POPO-1, BO-PRO-1, BOBO-1, TO-PRO-1, YO-PRO-1, TOTO-1 and YOYO-1. These dyes have the formula: ##STR4## where X is 0 or S; R1 is C1 -C6 alkyl, preferably methyl; and R2 is: ##STR5## and R4 and R5 are H, in which case the attached heterocyclic ring is a pyridine, or R4 and R5 taken in combination are --CH═CH--CH═CH--, in which case the attached heterocyclic ring is a quinoline. Alternatively, a second membrane permeant dye such as calcein AM (Molecular Probes, Inc.) can be used to detect viable cells by its conversion to a green-fluorescent product that is retained by viable cells. In this case, only viable cells are stained with a combination of a green fluorescent cytoplasmic stain and the red fluorescent 5-DAPP/LIVE nucleic acid stain and dead cells stain red but do not contain the green fluorescent stain. In yet another alternative, additional markers, including fluorescent and/or colored dyes, can be added to identify other characteristics of the cells stained with 5-DAPP/LIVE dyes. For example, a labeled protein specific for an external cell marker can be added to distinguish cells containing both the marker and the stained nucleic acids from cells without one or the other. Typically, live nucleated cells can be analyzed this way. First, one staining solution is prepared that contains a 5-DAPP/LIVE phenanthridium dye, where R is a linear alkyl chain containing from 5 to about 8 carbons, where the dye is present at a concentration between about 1 μM and about 25 μM. This concentration is sufficient to give a detectable red fluorescent signal inside living cells of interest. A second biologically compatible staining solution is prepared and added to the sample, either concurrently or sequentially. The second staining solution contains a fluorescent labeled protein that is specific for some aspect of the cells of interest, e.g. an antibody, lectin, protein A or protein G that binds selectively to the cells of interest. Preferably, the second reagent is detectable at a wavelength less than about 540 nm. Nucleated cells can be detected by the presence of both long wavelength and short wavelength fluorescence associated with the same cell. After the staining solution (preferably an aqueous or mostly aqueous solution containing an optimized dye concentration) is combined with a sample, sufficient time is allowed for the dye in the solution to stain intracellular nucleic acids to give a detectable fluorescent signal inside cells in the sample so that intracellular fluorescence can be evaluated. Generally, less than about 30 minutes is sufficient time for the dye to form a fluorescent dye/nucleic acid complex inside cells in the sample. Typically, the dye solution is combined with the sample for less than about 10 minutes; more typically for about 0.5 minutes to about 5 minutes, although some cells (e.g. lymphocytes) stain almost instantaneously. The differential rate of uptake of the dye into living cells can, in some cases, be used to identify and characterize the cell type in a mixture of cells or in a tissue. In general, staining of living cells with 5-DAPP/LIVE dyes that contain ring substituents such as phenethyl requires longer than staining with 5-DAPP/LIVE dyes in which the substituent is hexyl or octyl. Optimal staining of tissues and cells that have low permeability may require longer incubation periods of up to an hour or more. Where more than one fluorescent reagent is used, the staining solutions are combined with the sample long enough for both dyes to stain the cells or intracellular nucleic acids. In most cases the excess dye, if any, is removed by washing with fresh medium. Once sufficient time has elapsed for staining the intracellular nucleic acids in the sample, the sample is prepared for observation. The type of preparation depends on the type of sample and the method of observation being utilized. The preparation generally comprises illuminating the sample at a wavelength between about 480 nm and about 550 nm, typically at 480 to about 500 nm. When more than one fluorescent reagent is used the additional dye(s) are excited by light at a wavelength near the absorption maximum of the additional dye(s); preferably between about 320 nm and about 520 nm. The illumination can be accomplished by a light source capable of producing light at or near the wavelength of maximum absorption of the dye, such as an ultraviolet or visible lamp, an arc lamp, a laser, or even sunlight. Preferably the dye is excited by the argon laser at a wavelength equal to about 488 or 514 nm, or by a broad band excitation source between about 480 and 520 nm. The fluorescent signal of the dye-nucleic acid complex is assayed qualitatively or quantitatively by detection of the resultant light emission at a wavelength of greater than about 540 nm, preferably greater than about 580 nm. The emission is detected by means that include visible inspection, photographic film or electronic imaging, or use of instrumentation such as fluorometers, quantum counters, plate readers, microscopes and flow cytometers, or by means for amplifying the signal such as a photomultiplier. Quantitation of nucleic acid content is determined by comparing the amount of detectable fluorescence with a standard amount of fluorescence for a known amount of nucleic acid. When one or more additional fluorescent reagents are used, the sample is observed with means for separately detecting the red fluorescent signal at a wavelength greater than about 580 nm and of the second fluorescent signal at an appropriate wavelength (e.g. less than about 540 nm). It is seen from the examples that this series of dyes has several useful characteristics that include, but are not limited to, long wavelength absorption and emission maxima, moderately high affinity for DNA and RNA binding and high fluorescence enhancement on nucleic acid binding. Most importantly, the 5-DAPP/LIVE dyes are superior to ethidium for staining living cells because of their ability to be taken up by a variety of living cells (Examples 1-14). This can be measured qualitatively or quantitatively by several techniques that measure the enhanced fluorescence of the complex, including visual observation, microscopy (Examples 4-10 and 12-13), flow cytometry (Example 3), fluorescence spectroscopy, or analytical fluorometry (Examples 1 and 11). The short chain versions of the 5-DAPP/LIVE dyes (e.g. group 1 illustrated by butidium) have limited permeability in most cells, depending upon the system being stained, but has a higher binding affinity than the tested longer chain versions (see Table 1 ). In the longer chain versions (group 2 illustrated by hexidium, octidium and phenethidium) there is a marked enhancement of membrane permeability in all systems. Increasing the chain length of a normal alkyl substituent beyond about 6 carbons leads to increased partitioning into membranes and usually to somewhat slower equilibration with nucleic acid-containing compartments such as nuclei. Substitution of ethyl (as in ethidium) by phenethyl (as in phenethidium) facilitates entry of the 5-DAPP dye into living cells, but at a rate that is typically slower than derivatives in which the substituent is a C4 to C8 alkyl group. It is therefore preferred that the substituent R not be too large or too lipophilic; an optimum size of R for n-alkyl groups is pentyl, hexyl or heptyl (especially hexyl) in several types of cells. TABLE 1 ______________________________________ Dye K.sub.p.sup.3 ______________________________________ butidium.sup.1 9.8 × 10.sup.6 hexidium.sup.1 8.3 × 10.sup.6 octidium.sup.1 1.9 × 10.sup.6 propidium iodide.sup.2 3.8 × 10.sup.7 ethidium iodide.sup.2 8.3 × 10.sup.6 ______________________________________ .sup.1 Fluorescence spectra obtained using a standard ratio of 200 μM bp of DNA (bases of RNA) to 1 μM dye (standard solution) in a working buffer (10 mM phosphate, 10% (v/v) ethanol, 1 mM EDTA and 100 mM NaCl), p 7.4. Fluorescence was measured in a Corning 96 U well plate and Cytofluor ™ 2300 (excitation filter E (560/620), emission filter D (620/640), sensitivity 4) as a function of DNA concentration from 0-100 μM at a constant dye concentration of 0.5 μM. .sup.2 Fluorescence spectra obtained using the same method as above excep the fluorescence was measured in a Cytofluor ™ 2300 (excitation filter E (485/620); excitation D (620/640), and a sensitivity 4) as a function o DNA concentration from 0-30 μM at a constant dye concentration of 0.1 μM. .sup.3 DNA affinity (K.sub.p) determined by linear fitting of plots of reciprocal fluorescence enhancement versus reciprocal DNA concentration, as measured on a microtiter plate fluorescence reader (CytoFluor ™, Millipore). In some tissue culture cells, the pattern of staining is different from that observed in plant cells or bacteria. In the former case, cells are usually loaded with a brief pulse of dye, followed by a chase of buffered saline solution. These cells show a pattern of staining first in numerous intracellular compartments; e.g. lysosomes. In addition to staining these organelles first, the dyes also undergo a spectral shift to shorter wavelengths when associated with this "early-labeled compartment." If the same cells are exposed to pulses of higher concentrations of the 5-DAPP/LIVE dyes, the staining appears in the mitochondria (tubular structures that are labeled with rhodamine 123) and then, finally, in the nucleus, where it stains the nucleoli very brightly. Nucleoli are the most prominently stained area of higher eukaryotic cells, while the nuclei and cytosol usually stain in a hazy or punctate pattern in these cells. Animal cells loaded to equilibrium with hexidium usually show both intense cytoplasmic and nuclear staining. In plant tissues distinct nuclei tend to label uniformly, but there is frequently significant binding of the dye to cell walls. The plant cells are usually dark except for cell walls and nuclei. The characteristic binding morphology obtained using the 5-DAPP/LIVE dyes thus makes them useful in certain circumstances for identifying the type of cell in a mixed population of cells. Even the group 2 dyes are not very permeant in some systems, including certain fungal spores, and to a lesser extent, gram negative bacteria. This property confirms the utility of these dyes as differential stains, such as in the differential staining of gram positive and gram negative bacteria in Example 13. When the group 2 dyes are combined with dyes having different spectral properties and specificities (e.g. cell impermeant YOYO-1 ) they provide very good markers of all cells, including those with intact plasma membranes while the impermeant stain labels only the dead cells. This property is especially useful when attempting to discriminate between live and dead, gram positive and gram negative bacteria (Example 13), but can also be applied to the identification and sorting of fungal spore types, leukocytes, and cells undergoing mitogenic responses to stimulus with lectins, lymphokines, or other biochemical factors; or to detect the presence of excess nucleic acid content in virally-infected cells or those infested with intracellular protozoans such as Plasmodium spp. In general, as shown in FIG. 1 and in the staining results for several types of cells, ethidium does not enter most live cells easily, butidium enters live cells slowly and is usually not very bright, hexidium enters many types of live cells quickly and is bright and octidium enters cell membranes quickly. Octidium then becomes bright with continued incubation. Phenethidium enters gram positive bacteria but commonly enters tissue culture cells after 1 hr or more. The same trend in staining efficacy is obtained when peripheral blood lymphocytes are loaded with 5-DAPP dyes, but the proportion of the cell occupied by the nucleus is so large that distribution of the dye into this compartment is virtually instantaneous (on the scale of seconds) with butidium, hexidium and octidium, but not ethidium. EXAMPLE 1 OPTIMIZATION OF LIVE CELL STAINING BASED ON FLUORESCENCE INTENSITY A culture of Bacillus cereus is washed by centrifugation and resuspended in water to its original volume. Using Corning 96-well microtiter plates with flat bottoms, 150 μL volumes of suspension are loaded per well. A single well of sterile water is the well background standard. Using a Dynatech MR600 microplate reader equipped with a 410 nm filter, absorbance is determined for the initial volumes of suspension. The suspension is diluted by seven serial ten-fold dilutions in water, 150 μL of suspension per well. The absorbance is measured for each dilution. Following the absorbance measurements, each dilution loaded into wells is further diluted 1:10 and plated in duplicate on nutrient growth agar. The colonies are counted and expressed as colony forming units per milliliter (cfu/mL). Using the turbidity of the dilution in the microtiter plate, as described above, the suspension is diluted to a density of about 1×107 cfu/mL. Using Corning 96-well microtiter flat-bottom plates, a matrix is set up whereby the cell concentration decreases across the plate and the dye concentration decreases down the plate. The top row and first column are reserved for the control, which is sterile water. The bacteria suspension, adjusted to a known density of about 1×107 cfu/mL, as described above, is diluted seven times by serial ten-fold dilutions in water; 150 μL of suspension per well. Three-fold serial dilutions of 5-DAPP/LIVE dye are used (0.14-100 μM) and 10 μM of cell impermeant dead cell marker stain YOYO-1 is added to correct for dead cells. Fifty μL of a solution containing both dyes added at 4× their final concentrations to each well. The final volume per well is 200 μL. The plate is incubated at 25° C. for 30 minutes, then read in a Millipore Cytofluor™ 2300 96-well fluorescence microplate reader at a fixed excitation of 485±10 nm and emission wavelength of 520±20 nm and 620±20 nm. The high binding affinity of YOYO-1 precludes binding of the 5-DAPP/LIVE dyes to the nucleic acids of bacteria with compromised membranes. The measured intensity per well at 620 nm determines the best dye range and the best cell concentrations (concentrated through the first three ten-fold dilutions) for optimal dye loading while the intensity at 520 nm emission indicates the amount of dead cell staining. Suspensions containing a high percentage (>˜5%) of dead cells are not used in the optimization determination. The data collected allow the determination of optimal dye and cell concentration required for maximal fluorescence intensity per cell. EXAMPLE 2 MEASURING THE RELATIVE RATE OF UPTAKE OF DYES INTO CELLS Bacillus cereus is grown in nutrient broth to log phase, washed by centrifugation, and resuspended in water to a density of 5×106 cfu/mL (as determined in Example 1). One centimeter pathlength acrylic cuvettes containing 3 mL of cell suspension are placed in a fluorescence spectrophotometer equipped with a temperature regulated cuvette holder and magnetic stirrer. The suspensions are brought to 23° C. prior to dye addition. To a cuvette of 3 mL bacteria suspension is added 3 μL of 2 mM dye stock solutions in DMSO to give a final dye concentration of 2 μM to produce the maximum attainable fluorescence/cell at the 600 nm emission wavelength (determined as in Example 1). The peak fluorescence excitation and emission wavelengths are determined by scanning the spectrum of the dye in suspensions of Bacillus cereus incubated for 30 min with the dye. Fluorescence intensity of the suspensions is measured using 488 nm excitation and 600 nm emission wavelengths. Sampling of fluorescence is carried out at 5 or 10 Hz until the fluorescence signal appears to stabilize. The results of this measurement are shown in FIG. 1. The figure shows that the rate of dye loading into Bacillus cereus for the linear alkyl derivatives ethidium, butidium, hexidium and octidium increases with carbon chain length, but that the extent of loading is optimal for hexidium. EXAMPLE 3 OPTIMIZATION OF CELL STAINING BY FLOW CYTOMETRY Peripheral blood lymphocytes (PBL) are isolated from fresh heparinized goat blood and resuspended to a density of 1×106 cells/mL (as determined by direct microscopic count using a standard hemocytometer) in buffer consisting of 135 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM CaCl2, 1 mM MgCl2, pH 7.4 (HBSS+). YOYO-1 is added from a 2 mM DMSO stock solution to one mL aliquots of cell suspension to yield a final concentration of 1 μM YOYO-1. The cell suspension is incubated for 5 minutes at room temperature with YOYO-1 before adding enough 5-DAPP/LIVE (five-fold dilutions of the dye ranging in concentration from 20 mM to 2 μM are prepared in DMSO) to yield 1 nM to 10 μM final concentrations of dye with a total of DMSO concentration of 0.1%. Following a 15 minute incubation at room temperature the cells are analyzed in the flow cytometer by exciting both dyes at 488 nm and analyzing both green (YOYO-1) and red (5-DAPP/LIVE) fluorescence. Because of a nearly hundred-fold higher DNA binding affinity of YOYO-1 over 5-DAPP/LIVE and virtual impermeability of YOYO-1 to membranes the cells will fall into two discrete populations with vastly different red/green fluorescence ratios. The optimal concentration for 5-DAPP/LIVE loading of viable cells is that concentration at which maximal staining with 5-DAPP/LIVE is measured. EXAMPLE 4 STAINING OF MUSHROOM SPORES AS DETECTED BY MICROSCOPY Spores are rinsed from the gills on the underside of the cap of an agaric using a stream of distilled water. The spores are concentrated by centrifugation for 30 sec at 10,000 rpm in a microcentrifuge then a minimal volume of a 10-20 μM solution of the 5-DAPP/LIVE dye in distilled water is added. The suspension is incubated with the dye for 30 min at room temperature then a 15 μL aliquot of the suspension is mounted on between a coverglass and the slide for viewing in the presence of the dye. The cellular fluorescence is observed on a Zeiss Axioplan fluorescence microscope using fluorescein (long:pass emission) or rhodamine filter sets. The results of staining the spores of mushrooms are variable in that some stain while others do not. Those that are labeled are stained most effectively by hexidium. Ethidium enters less than about 10% of the spores, while butidium stains all spores. With butidium only about 10% of the spores are brightly stained. Hexidium stains all spores brightly while octidium stains only about 10% of them brightly. EXAMPLE 5 STAINING OF YEAST Yeast cells are washed by centrifugation and then resuspended in a solution of 2% glucose and 10 mM Na-HEPES, pH 7.4 to a cell density of between 5×105 and 2×106 cells/mL optical density at 410 nm (previously calibrated with YPD agar plate colony counts). Sufficient 10 mM stock solution of the 5-DAPP/LIVE dye in DMSO is added to effect a final concentration of 10 μM of the dye in the medium. The suspension is incubated for 30 min at 37° C. then 15 μL are placed between a coverglass and the microscope slide. The cellular fluorescence is observed using fluorescein (long-pass emission) or rhodamine filter sets. The staining of Saccharomyces with dyes of different chain lengths varies in distribution and intensity. Ethidium stains all yeast slightly with a pale red nucleus and hazy red cytoplasm. A similar pattern emerges with butidium, but there are more punctate cytoplasmic inclusions stained. Hexidium gives less of a hazy cytoplasmic stain and more distinct nuclei. Although somewhat less bright than hexidium staining, the octidium stains nuclei in somewhat less than 100% of the yeast and has markedly less cytoplasmic staining than any of the other forms. EXAMPLE 6 STAINING OF PLANT CELL TISSUE A small section of tissue from the bulb is removed with a razor blade. 0.5 mL of a 10 μM solution of the 5-DAPP/LIVE dye in distilled water is dispensed into a small glass dish. The epidermal tissue is cut into sections and placed in the dye solution. The tissue is stained for 30 min at room temperature in the dark then the tissue preparation is mounted in the presence of the dye between a coverglass and the slide. Cell walls of Alium spp. stain slightly; more hazy surface staining occurs with ethidium and butidium than with hexidium or octidium. Nuclear staining is evident with all dyes but improves with carbon chain length up to six. Octidium stains identically to hexidium. EXAMPLE 7 STAINING OF PROTOZOA 1 μL of 10 mM the 5-DAPP/LIVE dye stock is added to 1 mL of protozoan culture. The medium is incubated for 10 min at ambient temperature. 15 μL of this preparation is mounted with dye between a coverglass and the slide. Using this procedure, the nuclei of most cells of the free-living ciliate and flagellate protozoans are stained under these conditions. Hexidium is slightly better than octidium which is better than butidium and ethidium. EXAMPLE 8 STAINING OF SEA URCHIN SPERM Sperm cells are released from sea urchins by injection of KCl and the cells are concentrated by low speed centrifugation and suspended in 1 mL artificial seawater (ASW) at room temperature. Sufficient 10 mM dye stock solution is added to the sperm suspension to obtain a final dye concentration of 2 μM. The sperm are labeled by incubation in the dye solution for 5 min at room temperature. The sperm are washed by centrifugation at 2000 rpm for 1 min and then resuspended in 1 mL ASW before mounting and observation. It is observed that sperm nuclei stain brightly with hexidium. There is no apparent effect on the motility of the sperm or on its ability to fertilize a sea urchin egg. EXAMPLE 9 STAINING OF NUCLEI IN ADHERENT CULTURED MAMMALIAN CELLS 3T3 mouse fibroblast cells are grown on coverslips in calf serum-supplemented DMEM medium. The coverslips of cells are washed in HBSS+. 5-DAPP/LIVE dye solutions are prepared to a final concentration of 2 μM in DMEM without serum. One group of 3T3 cells is treated with 300 μM chloroquine (group 1). These cells and control cells (group 2) not treated with chloroquine are incubated at 37° C. for 30 min. The two groups of cells are transferred to DMEM plus 5-DAPP/LIVE. The cells are incubated in the dye-containing medium for 30 min at room temperature and are subsequently washed in HBSS+and viewed by epifluorescence microscopy using a long-pass fluorescein or a rhodamine filter set. After one half hour, the nucleus and cytoplasm of cells stained with butidium, hexidium or octidium appeared orange when viewed through the long-pass fluorescein filter (red with rhodamine excitation). Control cells (group 2) have relatively equal staining in the nucleus and cytoplasm and punctate staining-in the latter area. This is seen as tube-shaped regions; morphologically most similar to mitochondria. Cells treated with chloroquine are also stained throughout, but with a greater relative intensity of staining in the nucleus. Cytoplasmic fluorescence is less punctate than that seen in the control cells and fewer "tubular" bodies are seen. EXAMPLE 10 PULSE-CHASE STAINING OF LYSOSOMAL COMPARTMENTS IN CULTURED MAMMALIAN CELLS 3T3 mouse fibroblast cells are grown on coverslips in calf serum-supplemented DMEM medium. The coverslips of cells are washed using the HBSS+, then hexidium solutions are prepared to final concentrations of 2 μM and 0.2 μM in HBSS+. The cells are incubated in the dye-containing medium for 2 min at room temperature then they are washed in HBSS +and viewed by epifluorescence microscopy using a long-pass fluorescein or a rhodamine filter set. Brief pulse-chase loading of 3T3 cells with 0.2 μM hexidium results in labeling of punctate structures in the cell cytoplasm. Fluorescence from these structures appears green. Preincubation of the cells with 300 μM chloroquine reduces the amount of cytoplasmic staining. Loading with 2 μM hexidium for the same length of time results in additional organellar staining, which is apparently mitochondrial. Under both of these conditions nuclei are stained slightly, but only in the nucleolar regions. EXAMPLE 11 STAINING OF LYMPHOCYTES Peripheral blood lymphocytes (PBL) are isolated from fresh heparinized goat blood and resuspended in buffer consisting of 135 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM CaCl2, 1 mM MgCl2, pH 7.4 (HBSS+). The cells are resuspended to 106 mL (as determined by direct microscopic count using a standard hemocytometer) in a final volume of 3 mL in the above buffer in a quartz cuvette. 5-DAPP/LIVE dye stocks are prepared to final concentrations of 2 mM in DMSO. 3 μL of the octidium dye stock solution is injected into the cuvette to a final concentration of 2 μM. In a fluorometer, the sample is excited at 520 nm and fluorescence emission is monitored at 600 nm over the time required for the fluorescence signal to become stable. Hexidium, butidium and ethidium bromide are injected into separate samples of PBL to determine the relative rates of uptake for these stains. The volume of dye solution added to the cuvette is corrected by a factor relating the absorbance of the dye to the absorbance of a 2 mM octidium solution. With all indicators except ethidium bromide, a rapid increase in fluorescence is seen that reaches a stable level almost instantaneously. Ethidium bromide shows essentially no increase in fluorescence signal over time. EXAMPLE 12 COMPARISON OF TWO DIFFERENT CELL POPULATIONS USING TWO FLUORESCENT DYES The relative size of populations of bacteria in milk containing Streptococcus lactis and Salmonella typhimurium is determined by fluorescence microscopy after exposing the bacteria to 2 μM hexidium in combination with 1 μg/ml AMCA-IgG directed against Salmonella. The AMCA labeled IgG is prepared according to Brinkley, BIOCONJ. CHEM, 3, 1-13 (1992). Rabbit IgG is dissolved at 5-10 mg/mL in 50-100 mM sodium bicarbonate buffer pH about 8.2 at room temperature. AMCA dye in a sufficient amount from a stock solution is added to contain 0.25 mg of succinimidyl ester for each 10 mg of antibody. The solution of reactive AMCA dye should be added dropwise during a period of about 1 minute, using a Hamilton syringe (or equivalent) to the antibody solution with stirring while in an ice bath. The solution is allowed to warm to room temperature and is stirred for exactly two hours. The conjugate is separated from the unreacted dye on a Sephadex G-25 gel filtration column using an appropriate buffer and determine the degree of substitution of the conjugate by the procedure described in Brinkley, BIOCONJ. CHEM. 3, 1-13, (1992). Both dyes are prepared by dilution of 1 mM DMSO stock solutions in water. This combination allows detection of all bacteria, but Streptococci appear orange-red while Salmonella have a distinct blue halo when both are excited at 360 nm and observed with a 440 nm long-pass barrier filter. EXAMPLE 13 STAINING FOLLOWED BY FIXATION Adherent rainbow trout gonad cells (RTG-2) are grown at 20° C. until about 25% confluent. The cells are labeled by incubation in HBSS- containing 1 μM hexidium at room temperature for 30 min. The cells are subsequently washed free of hexidium with HBSS-, followed by phosphate-buffered saline, pH 7.4 (PBS), and fixed in 2% formaldehyde in PBS for 15 min at room temperature. Cell nuclei and cytoplasmic fluorescence are observed in the fluorescence microscope using fluorescein long-pass or rhodamine filter sets. There is essentially no difference between live cells loaded to equilibrium with 1 μM hexidium and cells loaded with the same concentration of hexidium and fixed with 2% formaldehyde. It is to be understood that, while the foregoing invention has been described in detail by way of illustration and example, numerous modifications, substitutions, and alterations are possible without departing from the spirit and scope of the invention as described in the following claims. What is claimed is: 1. A method of detecting nucleic acids in living mammalian or bacterial cells comprising:a) preparing a biologically compatible staining solution comprising a phenanthridium dye of the formula: ##STR6## where R is a hydrocarbon substituent that contains from 4 to about 10 carbons and is optionally saturated or unsaturated, and is linear or branched or contains an alicyclic or aromatic ring, and the symbol Ψ depicts the presence of the counterion used to neutralize the positive charge on the dye; where said dye is present at a concentration sufficient to give a detectable fluorescent signal inside living cells of interest; and b) combining the staining solution with a sample containing the living cells of interest; c) preparing the sample for observation by illuminating the sample with a light source capable of producing a light at or near the wavelength of maximum absorption of the dye; and d) observing the sample with means for detecting the fluorescent signal. 2. A method, as claimed in claim 1, for measuring the amount of nucleic acids in living cells, further comprising: comparing the amount of detectable fluorescence with a standard amount of fluorescence for a known amount of nucleic acid. 3. A method, as claimed in claim 1, further comprising adding to the sample a second fluorescent dye to detect the presence of cells in which the membrane is not intact. 4. A method, as claimed in claim 1, further comprising: sorting cells based on the amount of fluorescent signal per cell. 5. A method, as claimed in claim 1, where the R substituent of the phenanthridium dye is a C5-8 alkyl chain that is linear or branched. 6. A method, as claimed in claim 1, where the phenanthridium dye is hexidium. 7. A method, as claimed in claim 1, where the phenanthridium dye is present at a concentration less than 100 μM. 8. A method, as claimed in claim 1, where the phenanthridium dye is present at a concentration between 1 μM and 25 μM. 9. A method, as claimed in claim 1, where the sample is combined with the staining solution for 30 minutes or less. 10. A method, as claimed in claim 1, where the sample is observed with a laser scanner, a flow cytometer, a fluorescence microscope, or a confocal microscope. 11. A method, as claimed in claim 1, where the sample contains blood cells. 12. A method, as claimed in claim 1, where the sample contains mammalian cells. 13. A method, as claimed in claim 1, where the sample contains Gram positive bacteria cells. 14. A method, as claimed in claim 1, where preparing the sample for observation comprises illuminating the sample with a wavelength between about 480 nm and about 520 nm. 15. A method, as claimed in claim 14, where preparing the cells for observation further comprises fixing the cells prior to illumination. 16. A method for analyzing live nucleated mammalian cells comprising:a) preparing a first biologically compatible staining solution comprising a first reagent that is a phenanthridium dye of the formula: ##STR7## where R is a linear alkyl chain containing from 5 to 8 carbons, and the symbol Ψ depicts the presence of the counterion used to neutralize the positive charge on the dye; where said dye is present at a concentration between 1 μM and 25 μM that is sufficient to give a detectable red fluorescent signal inside living cells of interest b) combining the first staining solution with a sample containing the living nucleated cells of interest for a sufficient time for the first reagent to stain intracellular nucleic acids to give the detectable red fluorescent signal; c) preparing a second biologically compatible staining solution comprising a second reagent that is a fluorescent labeled protein that is an antibody, lectin, protein A or protein G that binds selectively to the cell of interest and is detectable at a wavelength less than about 540 nm; d) combining the second staining solution with the sample for a sufficient time for the second reagent to stain the cells to give a second fluorescent signal that is separately detectable from the red fluorescent signal; e) preparing the sample for observation by illuminating the sample with a light source capable of producing a light at or near the wavelength of maximum absorption of the first and second reagents; and f) observing the sample with means for separately detecting the red fluorescent signal at a wavelength greater than about 580 nm and of the second fluorescent signal at a wavelength less than about 540 nm. 17. A method of detecting nucleic acids in living mammalian cells comprising:a) preparing a biologically compatible staining solution comprising a phenanthridium dye of the formula: ##STR8## where R is a linear alkyl chain containing from 5 to 8 carbons, and the symbol Ψ depicts the presence of the counterion used to neutralize the positive charge on the dye; where said dye is present at a concentration between 1 μM and 25 uM that is sufficient to give a detectable fluorescent signal inside living cells of interest; and b) combining the staining solution with a sample containing the living mammalian cells of interest for a sufficient time for the dye to stain intracellular nucleic acids to give the detectable fluorescent signal; c) illuminating the sample with a wavelength between about 480 nm and about 520 nm; and d) observing the sample with an instrument for detecting the fluorescent signal. 18. A method, as claimed in claim 17, where the fluorescent signal is detected by a flow cytometer. 19. A method, as claimed in claim 17, where the fluorescent signal is detected by a microscope. 20. A method, as claimed in claim 17, further comprising: adding to the sample a second fluorescent reagent.

1993-05-17

en

1995-08-01

US-47018895-A

Thrie-beam terminal with breakaway post cable release ABSTRACT An end treatment for a thrie-beam type guardrail and a safety device specifically oriented toward trucks, vans and other utility vehicles having high profiles and centers of gravity. A slotted thrie-beam terminal is featured for use with highway guardrail systems. At least one reinforced slotted section is provided within the thrie-beam terminal to reduce the ability of the thrie beam to resist buckling in response to an axial type loading from end-on impacts. The terminal also provides for gating of laterally impacting vehicles. The terminal incorporates a break-away support post cable release mechanism which lessens risk to impacting vehicles which impact the lead post. This is a divisional of co-pending application Ser. No. 08/362,654 filed on Dec. 22, 1994, which is a continuation-in-part of Ser. No. 08/078,020, filed Jun. 15, 1993 now U.S. Pat. No. 5,407,298. 1. FIELD OF THE INVENTION The present invention relates generally to highway guardrail systems and road barriers. More particularly, the invention relates to improved new treatments for guardrail systems. 2. DESCRIPTION OF THE RELATED ART Pickup trucks, vans and other utility vehicles (hereinafter referred to as light trucks) have become increasingly popular in recent years. It has been estimated that over twenty-five percent of United States drivers own and operate a light truck, and this number may grow to represent One-third of the vehicle fleet. The Intermodal Surface Transportation Efficiency Act of 1991 specifically directed the Secretary of Transportation to revise guidelines and standards for acceptable roadside barriers and other safety appurtenances, including longitudinal barriers, end terminals, and crash cushions, to accommodate these light trucks. Light trucks generally have higher bumpers and higher centers of gravity than passenger cars and their impact performance is significantly different from that of passenger cars. In recognition of the increasing popularity of light trucks and the differences between light trucks and passenger cars, national highway safety standards are changing. Updated guidelines for safety performance evaluation of highway features, set forth in National Cooperative Highway Research Program (NCHRP) Report 350, recommends that highway safety devices, such as guardrails, end terminals, and crash cushions, be crash tested and evaluated with a 3/4 -ton pickup truck serving as a surrogate for all light trucks. NCHRP Report 350, issued in 1993, has been adopted by the Federal Highway Administration (FHWA) as the guidelines for crash testing and evaluation of all new highway safety features. The growing popularity of light trucks is leading to a rethinking in highway safety technology. One example is the thrie beam, which has been used in a number of states, such as California, Colorado, Massachusetts, Michigan, Nevada and Utah, as median and roadside barriers. The thrie beam is a corrugated metal rail which is typically installed on support posts along the roadside much as a standard W-shaped guardrail beam or "W-beam" would be. A thrie beam is wider than a standard W-beam rail, and, when installed, the width extends both above and below that of a W-beam guardrail. As such, it affords greater safety for drivers of light trucks than the W-beam, as it may be installed to coincide with the greater bumper heights of these vehicles. Although many suitable end treatments are known for W-beam guardrails and other standard guardrail designs, there are few suitable end treatments for the thrie beam design. The most common end treatments currently in use with the thrie beam guardrail are the turned-down end terminal and the transition to a W-beam rail with a crashworthy W-beam end terminal. A proprietary guardrail end treatment, known as SENTRE, manufactured by Energy Absorption Systems, Inc., is also adoptable for use as an end terminal for thrie beam guardrails. The turned-down end terminal involves sloping the end of the thrie beam down and affixing it into the ground. This end treatment eliminates the problem of vehicles spearing or impaling on the raised ends of the guardrail, but the design provides a ramp that, under certain impact conditions, could launch and vault the vehicle to the extent of becoming airborne for a considerable distance with the possibility of rollover. Indeed, the FHWA, in a memorandum dated Sep. 29, 1994, prohibited the use of turned-down end terminals on high-speed, high-volume roadways on the National Highway System (NHS). Using a specially fabricated transition section, the thrie beam rail can be transitioned to a W-beam rail and then terminated with crashworthy W-beam end terminal design. However, since the W-beam rail has a reduced capacity compared to the thrie-beam, this type of design increases the required length of guardrail. This, in turn, increases the overall cost of the end treatment. The SENTRE end terminal is constructed from a series of breakaway steel guardrail posts and frangible plastic containers containing sandbags. Impacting vehicles are decelerated as the guardrail posts release and sand bags in the plastic containers are impacted. A cable is used to guide vehicles away from the guardrail during impact. This system is very expensive, and has not gained wide acceptance. Related potential hazards are presented by guardrail support posts, whether those posts support a W-beam rail or a thrie beam rail. An end-on impact with an unmodified support post could result in ramping or vaulting of the vehicle. Breakaway support post arrangements are known wherein a frangible post is used which will shear or break away during an impact. The lead post, i.e., the post nearest the upstream end of the terminal, is typically provided with a tension support cable which extends between an unsupported point on the rail and the lower portion of the lead post. The lead post end of the cable is provided with a threaded metal fitting which is passed through a drilled hole in the lower portion of the post. A rectangular metal bearing plate with washer and nut are fastened on the end of the fitting. The tension support cable is designed to disengage when the post breaks away. However, results of crash tests have shown that the bearing plate may snag portions of the impacting vehicle and cause the vehicle to become entangled in the cable, resulting in the vehicle being brought to an abrupt halt. SUMMARY OF THE INVENTION The present invention provides a suitable end treatment for a thrie-beam type guardrail and a safety device specifically oriented toward pickup trucks, vans and other utility vehicles having high profiles, bumper heights and centers of gravity. It features a slotted thrie-beam terminal for use with highway guardrail systems. At least one reinforced slotted section is provided within the thrie-beam terminal to reduce the ability of the thrie beam to resist buckling in response to an axial type loading from end-on impacts. The terminal provides for gating of impacting vehicles. The present invention also includes a break-away support post cable release mechanism which lessens risk to impacting vehicles which break away the lead post during end-on impacts. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a portion of an exemplary thrie-beam guardrail incorporating an end terminal constructed in accordance with the present invention. FIG. 2 is a side view of upstream portions the end terminal of FIG. 1. FIG. 3 is an exploded view detailing portions of an exemplary breakaway post cable release constructed in accordance with the present invention. FIG. 4 is a cross-sectional view of an exemplary end terminal. FIG. 5 is a cross-sectional detail illustrating attachment of slot guards. FIG. 6 is an isometric detail showing attachment of slot guards proximate the downstream end of a slotted section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention offers an end terminal suitable for a thrie-beam guardrail. Referring first to FIGS. 1 and 2, an exemplary guardrail 50 is shown wherein a thrie-beam rail 52 is supported by posts 51 along its length. It may be appreciated that the guardrail 50 may be positioned alongside a roadway just as a more common and conventional guardrail would be, parallelling the roadway upon which traffic passes in the direction indicated by the arrows in FIG. 1. Terminal 10 is connected to the end of the guardrail 50. When so installed, terminal 10 presents an upstream portion 11 and a more downstream portion 13 with the upstream portion 11 disposed relative to the expected direction of traffic and longitudinally disposed loadings from end-on impacts by errant vehicles. In many respects, the terminal 10 is constructed and will operate in a manner similar to the slotted rail terminal described in U.S. Pat. No. 5,407,248 issued to Sicking et. al., assigned to the assignee of the present invention and which is herein incorporated by reference. As FIG. 1 illustrates, and as will be explained in further detail shortly, the terminal 10 may be installed so as to diverge slightly from the roadway toward its upstream portion 11. A buffered end section (not shown) may be attached to the upstream portion 11 of the thrie-beam rail 12. The downstream portion 13 is fixedly attached to the adjoining guardrail 50 by means of bolts, rivets or other connection means. Referring now to FIGS. 1 and 2, the terminal 10 includes a thrie-beam rail section 12 mounted on lead post 19 and support posts 18, 17, 16. As compared to a standard W-beam or other conventional guardrail, wherein the rail is mounted on the posts so as to present a relatively low and narrow barrier area, the thrie-beam rail presents a higher and wider barrier area more effective in stopping and slowing impacting trucks or other taller vehicles. A W-beam, for example, presents a barrier which is 12" wide from top to bottom of the barrier, the top of the barrier being 27" from the ground when mounted. The thrie-beam, on the other hand, has a top to bottom width of 20". When mounted on support posts, the top of the thrie-beam rail is 31" to 32" from the ground. The terminal 10 includes a series of multiple slotted zones, indicated generally at 20, longitudinally spaced along the rail 12. It is preferred that each slotted zone 20 be approximately centered or placed at quarter-distance points between the exemplary support posts 19, 18, 17, 16. The number and spacing of support posts may vary in accordance with terrain and other location-specific details. The slotted zone 20 comprises one or more slots 22 longitudinally disposed in the thrie-beam 12. The use of five slots is preferred as it provides for a relatively uniform and effective reduction of the thrie beam's resistance to longitudinal loading. A preferred placement for slots 22 within a slotted zone 20 is better understood with reference to the details for the exemplary thrie-beam rail 12 shown in FIGS. 5 and 6. A pair of valleys 24 and 26 are positioned between peaks 28, 30, and 32, each peak being formed by the intersections of inclined web portions 34. Edge members 36 laterally outlie peaks 28 and 32. Highly preferred placement for slots 22 is at the center portion of each peak 28, 30, 32 and each valley 24, 26. The slob 22 should be of a size sufficient to reduce the ability of the rail to resist buckling in response to longitudinal loading from one end of the rail 12. Recommended sizes for the slots are approximately one-half inch in width and a minimum of 12" in length. However, the dynamic buckling strength of the guardrail terminal can be tuned to different desired levels by controlling the number and length of slots 22. Generally, larger and longer slots have reduced dynamic buckling strength to a greater degree as has a greater number of slots. It is preferred that each slot 22 be reinforced proximate the downstream end of each slotted zone 20 to resist too great an expansion of the slot in an impact, which could result in tearing of the rail 12 and an uncontrolled stop of the vehicle. One suitable method of reinforcing downstream end of the slots 22 is through attachment of a "slot guard" 38 as described in further detail in U.S. Pat. No. 5,487,298. Other methods of reinforcement include use of thickened welds or plates bolted onto the beam 12 proximate the downstream end of the slots 22. As best seen in FIGS. 2, 3 and 4, the lead post 19 is of the breakaway variety. The post 19 is inserted into a box-shaped foundation tube 40 which is buried to be nearly flush with the surface. The post 19 is preferably fashioned from wood which is readily frangible in a collision. A tension support cable 42 extends from the thrie-beam rail 12 to the lower portion of the lead post 19 where a hole 44 has been drilled therethrough. The support cable is maintained in tension and provides additional anchorage for the rail 12 during lateral impacts, i.e., impacts along the side of the rail rather than from its end. The upper end of the support cable 42 is attached to the rail 12, typically by means of a shoe 46 which holds the cable in place against the rail and which is attached to the rail 12 by bolts or welds. Usually, an unsupported portion of the rail 12 which is not within a slotted zone 20 is used for this connection. The lower end of support cable 42 passes through the hole 44. The end of the cable 42 is provided with a threaded fitting 47 upon which is fastened a nut 48 and washer 49. A slotted bearing plate 60 is positioned between the washer 49 and the lead post 19. When installed, the bottom edge of the slotted bearing plate 60 rests on the ground, as shown by FIGS. 2 and 4. The slotted bearing plate 60 presents a cable resting notch 62 proximate its center. A cutout portion 64 extends upward from the cable resting notch to the outer edge of the slotted bearing plate. Outward of the cable resting notch 62, the cutout portion 64 must have a width at least as great as that of the cable fitting 47 such that the cable fitting 47 may be easily removed from the notch 62. It is greatly preferred that the cutout portion 64 have a much greater width so that the slotted bearing plate 60 is relatively certain to fall away from the fitting 47 once the fitting 47 is moved outward from the notch 62 along the cutout section 64. One preferred shape for the cutout section, as shown in FIGS. 3 and 4, is a V-shaped slot which extends from the upper edge of the plate 60 to the notch 62. In operation, the thrie-beam rail terminal 10 is typically positioned along a highway to prevent laterally impacting vehicles from penetrating the guardrail unimpeded and encroaching into the area shielded by the guardrail. It is intended that a vehicle will impact the guardrail terminal 10 downstream of its upstream portion 11 and on the side of the terminal 10 facing the roadway. Although the terminal 10 may be installed so that it is aligned with the guardrail to which it is attached, it is preferred that the terminal 10 extend angularly away from the roadway, as illustrated in FIG. 1. This angular departure facilitates "gating" of laterally impacting vehicles to the side of the rail opposite the roadway. Methods of installing the terminal at an angular departure are described in greater detail in U.S. Pat. No. 5,487,298 . During a collision with a vehicle which impacts the terminal 10 at its upstream portion 11, the rail portions which include the slotted zones 20 will buckle more readily than other sections of the rail 12. Due to the buckling, the rail should cushion the impact of the vehicle rather than bringing the vehicle to an abrupt, jolting halt. Upon impact with the upstream portion 11, a vehicle travelling at a moderate to high speed will likely shear frangible lead post 19. As the thrie-beam rail 12 buckles at its slotted zones 20 and collapses with the impact, tension is placed upon the tension cable 42 in an upward and downstream direction. Once the lead post 19 is sheaxed away, the lower end of the cable 42 and the fitting 47 are pulled upward and downstream. Due to the presence of the cutout section 64, the fitting 47 is freed from the slotted bearing plate 60. Although described in terms of the preferred embodiments, those skilled in the art will recognize that the invention is susceptible to numerous modifications and variations which fall within the scope and spirit of the invention. What is claimed is: 1. A cable release mechanism comprising:a generally vertical support member having an aperture therethrough; a cable having an end which is disposed through the aperture of the support member; a fastener located proximate said end of the cable which prevents withdrawal of said end of the cable from disposal through the aperture; a release plate disposed between the fastener and the support member, the release plate having a cable resting notch and a cut out section to permit a cable resting within the cable resting notch to be removed from the plate. 2. The cable release mechanism of claim 1 wherein the cutout section comprises a V-shaped slot. 3. The cable release mechanism of claim 1 wherein the support member comprises a frangible guardrail support post.

1995-06-06

en

1996-04-02

US-16096693-A

Photo-coupler apparatus ABSTRACT A photo-coupler apparatus has a light emitting element in the primary side. The secondary side of this apparatus is comprised of a photoelectromotive diode array, a light sensitive impedance element series-connected to said array, a drive transistor, and at least one output MOSFET connected to the output terminals of this apparatus. The light sensitive impedance element comes into a large impedance state when an optical signal from the light emitting element is weak. In this case, the light sensitive impedance element generates a sufficient voltage to activate the drive transistor, in spite of the photocurrent being small. This results in an improvement of the dynamic sensitivity of this apparatus. When said optical signal is strong, the impedance element comes into a small impedance state, thus providing the MOSFET with a sufficient photo-current. This results in the shortening of switching times of the output MOSFET. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention generally relates to a photo-coupler apparatus, and more particularly, to a photo-coupler apparatus having at least one MOSFET as an output contact. 2. Description of the Prior Arts FIG. 1 shows the circuit diagram of a prior art photo-coupler apparatus (first prior art). This prior art has been published in Japanese unexamined patent publication TOKUKAISHO 57-107633 which corresponds to U.S. Pat. No. 4,390,790, and EPS 0048146. The photo-coupler apparatus of the first prior art has a light emitting diode 1 at the primary side. The secondary side of this device is comprised of the following: a first photoelectromotive diode array 2a photo-coupled with light emitting diode 1; a second photoelectromotive diode array 2b photo-coupled with light emitting diode 1; a resistor 3 parallel-connected with second diode array 2b; a normally-ON drive FET 5; and an output MOSFET 4. In this figure, numbers 8 and 8' show the input terminals and numbers 9 and 9' show the output terminals of this photo-coupler apparatus. As shown in FIG. 1, the photo-coupler apparatus has two photoelectromotive diode arrays 2a and 2b. Once the second photoelectromotive diode array 2b has received a light from light emitting diode 1, it creates an electromotive force. Because of this electromotive force, drive FET 5, which is normally 0N, turns off. Then, the gate-source capacitor of output MOSFET 4 is rapidly charged by the photo-current from first photoelectromotive diode array 2a. Once the incident light from light emitting diode 1 is interrupted, the accumulated charges between the gate and source of drive FET 5 are discharged through resistor 3, thus permitting drive FET 5 to turn on. At this time, the charges accumulated between the gate and source of output MOSFET 4 are rapidly discharged via the source and drain of drive FET 5 which is now in an ON state, allowing MOSFET 4 to turn off quickly. As described above, the photo-coupler apparatus of the first prior art should include second photoelectromotive diode array 2b so as to control drive FET 5. Due to the existence of array 2b, the chip area of this apparatus increases, thus also increasing its manufacturing cost. In FIG. 2A, the circuit structure of a photo-coupler apparatus is shown according to the second prior art of this invention. This apparatus has been published in Japanese unexamined patent publication TOKUKAISHO 63-99616 which corresponds to U.S. Pat. No. 4,873,202. The second prior art photo-coupler apparatus has a light emitting diode 1 at the primary side. The secondary side of this apparatus is comprised of the following: a photoelectromotive diode array 2 which is photo-coupled with light emitting diode 1; an impedance element 6 connected in series with array 2; normally-ON drive FET 5; and output MOSFET 4 connected to output terminals 9 and 9'. In this photo-coupler apparatus, once photoelectromotive diode array 2 receives a light from light emitting diode 1, a current flows through impedance element 6. Due to this current, a voltage difference, which can activate FET 5, arises between the source and gate of FET 5. Therefore, this apparatus does not need second photoelectromotive diode array 2b shown in FIG. 1 for the activation of drive FET 5. In this case, however, impedance element 6 limits the charging current for the capacitor of MOSFET 4 when the resistance value of element 6 is large. This fact makes the charging period for MOSFET 4 longer. Thus, the time T-on, which is the period from the signal input to the turn-on of output MOSFET 4, becomes longer. Impedance element 6 also works as a discharge resistor for discharging the accumulated charges at the source and gate of FET S. Therefore, if the resistance value of impedance element 6 is large, the discharging period of FET 5 becomes longer. As a result, time T-off, which is the period from the cut off of an input signal to the turn-off of output MOSFET 4, becomes longer. On the contrary, if the resistance value of impedance element 6 is small, the current flowing through impedance element 6 must be increased to obtain a sufficient voltage for the activation of drive FET S. Therefore, the magnitude of minimum input current I-ft, which is required to turn on MOSFET 4, becomes larger, thus deteriorating the dynamic sensitivity of this device. As is evident from the above mentioned explanation, there is a trade-off between the switching times (T-on and T-off) and the minimum input current I-ft of MOSFET 4. This trade-off prevents the complete improvement of the characteristics of this photo-coupler apparatus. FIG. 2B shows the characteristic curves of the second prior art photo-coupler apparatus. The detail of this figure will be explained later in conjunction with one embodiment of this invention. In FIG. 3A, the circuit structure of a photo-coupler apparatus is shown according to the third prior art of this invention. This apparatus has been published in Japanese unexamined parent publication TOKUKAISHO 63-153916 which corresponds to U.S. Pat. No. 4,801,822. This apparatus has a light emitting diode 1 at the primary side. The secondary side of this apparatus is comprised of the following: a photoelectromotive diode array 2 which is photo-coupled with light emitting diode 1; impedance element 6' including a resistor 6a and a zener diode 6b connected in parallel with each other; normally-0N drive FET 5; and output MOSFET 4 connected to output terminals 9 and 9'. In this photo-coupler apparatus of the third prior art, impedance element 6' is comprised of the parallel circuit of resistor 6a and zener diode 6b as mentioned above. Because zener diode 6b works as a bypass for resistor 6a, most of the photo-current from array 2 flows through zener diode 6b, not through resistor 6a, when the current amount is large. As a result, resistor 6b does not limit the amount of charging current for MOSFET 4. This fact permits resistor 6b to have a greater value of resistance without making T-on longer. Time T-on and minimum input current I-ft can, therefore, be improved simultaneously in the third prior art. In said case, however, there are still some problems. That is, an extra component, zener diode 6b, is necessary to construct the photo-coupler apparatus. And, if resistor 6b has a large value of resistance so as to reduce the amount of input current I-ft (that is, to improve the dynamic sensitivity), time T-off becomes longer. FIG. 3B shows the characteristic curves of the third prior art photo-coupler apparatus. The detail of this figure will be explained later in conjunction with another embodiment of the present invention. To summarize the above mentioned results, the photo-coupler apparatus of the prior arts have the following disadvantages: (1) the photo-coupler apparatus having two photoelectromotive diode arrays (in the first prior art) requires an additional chip area for the installation of the second photoelectromotive diode array in order to activate a drive FET, thus increasing the chip area as well as the manufacturing cost; (2) although it does not require the second photoelectromotive diode array, the second prior art photo-coupler apparatus, in which an impedance element is series-connected with a photoelectromotive diode array, presents a trade-off relation between the switching times (T-on and T-off) and the minimum current I-ft (that is, sensitivity), thus preventing the improvement of the entire characteristics of this apparatus; (3) the third prior art photo-coupler apparatus, in which an impedance element is comprised of a resistor and a zener diode parallel-connected each other, can improve both T-on and I-ft simultaneously, but it requires an extra component, zener diode 6b, and time T-off becomes longer if a large value of resistor is used to improve I-ft. SUMMARY OF THE INVENTION This invention has been made to overcome the above mentioned disadvantages of the prior art photo-coupler apparatus. Therefore, the objective of the present invention is to provide a photo-coupler apparatus having at least one output MOSFET as an output contact, the apparatus which is capable of shortening the switching times of output contacts and improving its dynamic sensitivity simultaneously. In order to implement the above mentioned objective, the secondary side of the photo-coupler apparatus of this invention is comprised of a photoelectromotive diode array 2, a light sensitive impedance element 10, at least one output MOSFET 4 connected to output terminals 9 and 9', and a normally-ON drive transistor 5, as shown in FIGS. 4, 7, and 10. Impedance element 10 is connected in series with photoelectromotive diode array 2 and changes its impedance value according to the intensity change of an input light. In actuality, impedance element 10 has a small impedance value when the light intensity from a light emitting element is strong, and a large impedance value when the light intensity is weak. According to the above mentioned structure, normally-ON drive transistor 5, which is used to shorten the switching times of output MOSFET 4, is driven by the voltage difference across element 10. When the light intensity is strong and so the charging current for the gate-source capacitor of MOSFET 4 is large in amount, impedance element 10 comes into a small impedance state, thus not limiting the charging current for MOSFET 4. As a result, time T-on of output MOSFET 4 is shortened. On the other hand, when the light intensity is weak, impedance element 10 comes into a large impedance state, thus generating a voltage difference, which is sufficiently high to activate drive transistor 5, across impedance element 10. Due to this fact, the minimum current I-ft required to turn on output MOSFET 4 becomes smaller, thus improving the dynamic sensitivity of this apparatus. In order to drive the photo-coupler apparatus in a high speed switching mode, both time T-on and time T-off, which is the period from the interruption of an input signal to the turn off of output MOSFET, should be shortened. To this end, a large signal should be applied to light emitting element 1 so as to emit a strong light. When photoelectromotive diode array 2 receives a strong light, a large amount of current is generated in this array and it charges the gate-source capacitor of MOSFET 4 quickly. As a result, time T-on is shortened. On the other hand, time T-off can be shortened by adjusting the light responding rate of impedance element 10. In other words, if impedance element 10 is so arranged that it keeps the small resistance state for a while (a period during which the charges between the source and gate of transistor 5 can be discharged) after an input signal having been interrupted, that is, no light is emitted by light emitting element 1, drive transistor 5 rapidly comes into an ON state during this period, thus shortening time T-off. As is evident from the above mentioned explanation, the photo-coupler apparatus of this invention is capable of improving its dynamic sensitivity and shortening the switching times of output contacts simultaneously. In addition, in order to further raise the limiting value of charging up current for the MOSFET, a zener diode 10b may be parallel-connected with light sensitive impedance element 10 as shown in FIG. 8. In this structure, in the same manner as that of the above mentioned photo-coupler apparatus, light sensitive impedance element 10 has a large resistance when a light signal is so weak that a high sensitivity is required, thus improving its dynamic sensitivity. On the other hand, when the light signal is so strong that a sufficient amount of current flows for charging MOSFET 4, impedance element 10 comes into a small resistance state and does not limit the charging up current. Thus, time T-on is shortened. As a result, the photo-coupler apparatus having this structure can improve the dynamic sensitivity and shorten time T-on. Impedance element 10 may be fabricated to keep the small resistance state for a while after an input light has been interrupted. In this case, drive transistor 5 quickly turns on during this period. Thus, time T-off is also shortened. Still in addition, normal diode array 10c may be connected in place of zener diode 6b as shown in FIG. 9. In this structure, the clamp voltage of array 10c can be arranged by changing the number of diodes. As a result, the photo-coupler apparatus having this structure can further improve the charging efficiency. These and other objectives, features, and advantages of the present invention will be more apparent from the following detailed description of preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the circuit structure of a photo-coupler apparatus according to the first prior art of this invention; FIG. 2A shows the circuit structure of a photo-coupler apparatus according to the second prior art of this invention; FIG. 2B shows the V-I characteristics of some elements used in the photo-coupler apparatus shown in FIG. 2A; FIG. 3A shows the circuit structure of a photo-coupler apparatus according to the third prior art of this invention; FIG. 3B shows the V-I characteristics of some elements used in the photo-coupler apparatus shown in FIG. 3A; FIG. 4 shows the circuit structure of a photo-coupler apparatus according to the first embodiment of this invention; FIG. 5 is a cross sectional view of the impedance element shown in FIG. 4; FIG. 6A is a view showing the voltage variation of an input signal for the photo-coupler apparatus shown in FIG. 4; FIG. 6B is a view showing the resistance variation of the impedance element shown in FIG. 4; FIG. 6C is a view showing the output voltage variation from the MOSFET shown in FIG. 4; FIG. 7 shows the circuit structure of a photo-coupler apparatus according to the second embodiment of this invention; FIG. 8 shows the circuit structure of a photo-coupler apparatus according to the third embodiment of this invention; FIG. 9 shows the circuit structure of a photo-coupler apparatus according to the fourth embodiment of this invention; and FIG. 10 shows the circuit structure of a photo-coupler apparatus according to the fifth embodiment of this invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 4 shows the circuit structure of a photo-coupler apparatus according to the first embodiment of the present invention. The photo-coupler apparatus of this embodiment has a light emitting element 1 in the primary side. Element 1 emits a light after having been activated by an input signal introduced through input terminals 8 and 8'. The secondary side of this apparatus is comprised of the following: photoelectromotive diode array 2 which generates an electromotive force by receiving a light signal from light emitting element 1; a light sensitive impedance element 10 whose impedance value varies according to the strength of the light signal from light emitting element 1; an output MOSFET 4 whose gate and source are connected with the respective ends of the series connected circuit of photoelectromotive diode array 2 and impedance element 10; and a normally-ON drive transistor 5. The control electrode (base) of this transistor 5 is connected to the node of photoelectromotive diode array 2 and impedance element 10. Also, the conducting electrodes (source and drain) of this transistor 5 are connected with the gate and the source of MOSFET 4 respectively. The output of this apparatus is obtained through output terminals 9 and 9'. Light sensitive impedance element 10 presents a small impedance value when a strong light is given by light emitting element 1. On the contrary, it presents a large impedance value when a weak light is given by light emitting element 1. In this embodiment, an n-channel type junction FET (J-FET) is used as drive transistor 5. FIG. 5 illustrates the cross-sectional structure of light sensitive impedance element 10. This element is comprised of a diffused resistor 54 formed in an island which is electrically isolated from silicon substrate 51 by oxide film (SiO2) 57 and poll-silicon 58. Boron (B) or antimony (Sb) may be used as the impurity which is diffused into resistor 54. In this figure, 55 shows an oxide film (SiO2) and 56 shows an aluminum wiring. In such a device, an incident light is received by a part of diffused resistor 54 where it is not covered by aluminum wirings 56. The impedance of this element 10 can be changed by changing the shape of diffused resistor 54 and the size of its exposed area. A commercially available CdS light sensor may be used as impedance element 10. However, it is appropriate that impedance element 10 is integrated into one chip together with photoelectromotive diode array 2 and FETs. In this case, the above mentioned diffused resistor may be used as impedance element 10. When an incident light from light emitting device 1 is strong, light sensitive impedance element 10 has a small resistance. Due to this strong light, however, a large current flows through element 10, thus inducing a voltage, which is sufficiently high for the drive of transistor 5, across element 10. Transistor 5 then turns off. In this case, therefore, most of the photo-current generated by photoelectromotive diode array 2 is used in order to charge the gate-source capacitor of MOSFET 4. Because its resistance value is small, element 10, which is series-connected on the charging path, does not limit the charging current for MOSFET 4. This fact permits MOSFET 4 to rapidly turn on. Once the incident light from light emitting element 1 is interrupted, the accumulated charges between the gate-source capacitor of transistor 5 are promptly discharged because the resistance of element 10 stays small for a while. As a result, transistor 5 rapidly turns on, allowing the gate and source of MOSFET 4 to conduct. Then, the accumulated charges between the gate and source capacitor of MOSFET 4 are promptly discharged, permitting MOSFET 4 to come into an off-state quickly. When the incident light from light emitting element 1 is weak, element 10 has a large resistance. Due to this fact, a voltage, which is sufficiently high for the drive of transistor 5, is generated across element 10, in spite that photo-diode array 2 generates only a small amount of photo-current. Then, transistor 5 turns off so as to charge up the gate and source capacitor of MOSFET 4 with the photo-current. MOSFET 4 is, thus, set to an ON-state. Accordingly, even in the case where the current of an input signal is small, and so, light emitting element 1 emits only a weak light, MOSFET 4 can be set to an on-state. Thus, the photo-coupler apparatus presents a high sensitivity. In order to explain the operation of this photo-coupler apparatus, the V-I characteristics of the second prior art apparatus will be described first with referring to FIG. 2B. As mentioned before, the photo-coupler apparatus of the second prior art has a simple resistor as impedance element 6. FIG. 2B shows the operational characteristics of this apparatus. Lines Ra, Rb and Rc in FIG. 2B show the V-I characteristics of element 6 when it has a large, small, or medium value of resistance. The MOSFET's operational points, at which MOSFET 4 turns on to be a steady state, are shown as the intersecting points of each V-I characteristic line and the Vgs-Ids characteristic line of transistor 5. Therefore, current Ia, Ib, or Ic of each operating point shows the minimum current required to turn on MOSFET 4 in each case. In order to improve the dynamic sensitivity of this apparatus, the minimum current should be as small as possible. On the other hand, when the photo-current is sufficiently large, the amount of charging current for the gate-source capacitor of MOSFET 4 is limited by the resistance value of impedance element 6. Voc in FIG. 2B shows the open end voltage of photoelectromotive diode array 2. For resistance values Ra and Rc, the maximum currents which can flow through array 2 and impedance element 6 are ia and ic. As is evident from this fact, when the resistance of impedance element 6 is large, very little current flows in the circuit. As the current becomes smaller, the period required for the charging of MOSFET 4 becomes longer. Accordingly, a large current is required for shortening time T-on. To sum up, when impedance element 6 has a large resistance (Ra), the operating current is very small, that is, Ia. This means the dynamic sensitivity of this apparatus is very high. In this case, however, T-on becomes longer due to the small current value, i.e., Ia. On the contrary, when element 6 has a small resistance value (Rb), the limiting value of current becomes sufficiently large to shorten T-on. However, the operating current becomes Ib, thus deteriorating the dynamic sensitivity. In practice, the resistance of element 6 is determined by finding a point of compromise around the mean value, i.e., Ia in FIG. 2B. As explained above, the resistance of impedance element 6 is actually fixed in the second prior art. In said first embodiment of the present invention, the resistance of impedance element 10 varies according to the intensity change of an input light. In other words, when the intensity of light signal is weak, that means a high sensitivity is required, the resistance is sufficiently large (Ra), resulting in the high sensitivity. On the other hand, when the intensity of light signal is strong to generate a large current, the resistance of element 10 becomes smaller (Rb), thus raising the limit value of current. This makes T-on shortened. As a result, the apparatus of this embodiment can implement the high sensitivity and the shortening of T-on simultaneously without adding extra components such as zener diode 6a of the third prior art. In addition, if impedance element 10 stays in a small resistance state for a certain period (a period during which the accumulated charges between source and gate of transistor 5 are discharged) after the input signal has been interrupted, transistor 5 rapidly turns on to shorten T-off. FIGS. 6 show the relation between the input signal for light emitting element 1 and the corresponding output from the output terminals of this apparatus. Particularly, FIG. 6A shows the voltage variation of the input signal, FIG. 6B shows the resistance variation of impedance element 10 according to the input voltage variation shown in FIG. 6A, and FIG. 6C shows the output voltage variation of this apparatus according to the resistance variation shown in FIG. 6B. As is evident from these figures, the resistance of element 10 gradually increases during time t2 to t3. The accumulated charges between the gate and source of transistor 5 are promptly discharged during this time. As a result, T-off is shortened. To control the light responding rate of impedance element 10, there are some approaches widely known. One of them is, for example, to control the life timer of photo-carriers by irradiating electron beams or proton beams and implanting ions into the resistor. Another is to change the area size of the resistor so as to change the parasitic capacitance of the resistor. Next, the second embodiment of this invention will be explained below with referring to FIG. 7. The photo-coupler apparatus shown in FIG. 7 uses a p-channel junction FET 5a instead of n-channel junction FET 5 used in the first embodiment of this invention. Therefore, the operation and advantages of this embodiment are almost the same as those of the first embodiment. FIG. 8 shows the structure of a photo-coupler apparatus according to the third embodiment of this invention. In addition to the structure of the first embodiment, this photo-coupler apparatus has an additional zener diode 10b which is parallel-connected with light sensitive impedance element 10. Zener diode 10b in this structure conducts when an input light is strong, thus removing the limitation of charging up current for MOSFET 4 in cooperation with light sensitive impedance element 10. The operational characteristics of this embodiment will be explained with referring to the characteristics of the third prior art apparatus in which impedance element 6 is comprised of resistor 6a and zener diode 6b. In fact, FIG. 3B shows V-I characteristics of transistor 5, zener diode 6b and resistor 6a shown in FIG. 3A. As is evident from FIG. 3B, when the charging up current for the gate-source capacitor of MOSFET 4 exceeds a certain value, it is bypassed through zener diode 6b. Therefore, even if resistor 6a has a large resistance value, the charging up current for MOSFET 4 is not limited. As a result, the apparatus shown in FIG. 3A can simultaneously implement the high dynamic sensitivity and the shortening of time T-on. In spite of these advantages, the apparatus shown in FIG. 3A is disadvantageous in that it requires an extra component, e.i., zener diode 6b. In addition, if resistor 6a has a large value, time T-off becomes longer. This is because resistor 6a is also used as the discharging resistor for transistor 5. The resistance value of impedance element 6a is fixed as mentioned before in the third prior art. On the contrary, the photo-coupler apparatus of the third embodiment of this invention changes its resistance value according to the intensity change of an incident light. In the case where the incident light is so weak that a high sensitivity is required, impedance element 10 has a large resistance value (Ra), thus implementing the high sensitivity. On the other hand, when the incident light is strong so that a large amount of charging current is applied to MOSFET 4, impedance element 10 represents a small resistance value (Rb shown in FIG. 2B) to remove the current limitation, thus shortening time T-on. As a result, this apparatus can simultaneously implement the high dynamic sensitivity and the shortening of time T-on. In addition, after the incident light has been interrupted, impedance element 10 stays in a small resistance state for a certain period. This makes transistor 5 turn on rapidly, thus also shortening time T-off. FIG. 9 shows the circuit structure of a photo-coupler apparatus according to the fourth embodiment of this invention. This apparatus has normal diode array 10c instead of zener diode 10b shown in the third embodiment. In said third embodiment, to lower the pinch-off voltage of drive transistor 5 is not difficult. But, it is very difficult to lower the zener voltage of diode 10b below a certain value. Thus, when the charging up current for MOSFET 4 is large, the voltage drop (clamp voltage) caused by zener diode 10b becomes so large that the voltage applied on the gate of MOSFET 4 becomes lower. This results in the deterioration of the charging efficiency for MOSFET 4. The fourth embodiment overcomes the above mentioned problem by applying normal diode array 10c into the circuit. The clamp voltage of diode array 10c can be arranged by changing the number of diodes used in the array. Thus, by optimizing both the clamp voltage and Vp on Vgs-Ids characteristic of transistor 5, the charging efficiency of this apparatus can be further improved. FIG. 10 shows the circuit structure of a photo-coupler apparatus according to the fifth embodiment of this invention. The apparatus of this embodiment has MOSFET 4' in addition to the structure of the first embodiment. In fact, two MOSFETs 4 and 4' are antiseries-connected each other with source common. Due to this structure, the apparatus of this embodiment can control an AC signal. As explained above, the photo-coupler apparatus of this invention has a structure to drive a normally-ON drive transistor, which is provided in order to shorten the switching times of an output MOSFET, by the voltage difference generated across a light sensitive impedance element. When the incident light from a light emitting element is strong, and so, the charging up current for the gate-source capacitor of the MOSFET is large, the light sensitive impedance element comes into a small resistance state. Accordingly, the charging up current for the MOSFET is not limited by the impedance element, thus shortening the switching-on period of the MOSFET. On the other hand, when an incident light from the light emitting element is weak, the impedance element presents a large resistance value. Then, a considerable voltage difference to turn-off the normally ON transistor arises across the light sensitive impedance element. Due to this fact, the minimum current required for turning on the output MOSFET is further reduced in this invention. The dynamic sensitivity of this apparatus is, thus, improved. In addition, the switching off time of the output MOSFET can be shortened by adjusting the light responding rate of the impedance element. As a result, a photo-coupler apparatus having an improved dynamic sensitivity and shorter switching times of output contacts can be obtained in this invention. In addition, a zener diode may be parallel-connected with the light sensitive impedance element so as to bypass the charging up current for the output MOSFET. In this structure, zener diode conducts when an input light is strong, thus removing the current limitation for charging up the MOSFET in cooperation with the light sensitive impedance element. Further, when the intensity of an input light is weak, the impedance element presents a large resistance value, thus improving the dynamic sensitivity of this apparatus. On the other hand, when the intensity of the light signal is strong and so the charging up current is large, the impedance element presents a small resistance value. This enables to higher the limiting value of charging current. Consequently, the apparatus of this invention can implement the high dynamic sensitivity as well as the shortening of the turn-on time. Further, the impedance element stays in the small resistance state for a while after the input signal has been interrupted. During this period, the drive transistor comes into an off-state rapidly, thus also shortening the period to turn off the MOSFET. So, a photo-coupler apparatus having an improved dynamic sensitivity as well as shorter switching times of output contacts can be obtained in this invention. Still in addition, a normal diode array can be used in place of the above mentioned zener diode. Due to this structure, the clamp voltage of the diode array can be adjusted by changing the number of diodes. Thus, a photo-coupler apparatus having an improved charging efficiency can be obtained in this invention. What is claimed is: 1. A photo-coupler apparatus comprising:a light emitting element for emitting light by an input signal; a photoelectromotive diode array for generating photoelectromotive force by receiving an optical signal from said light emitting element; a light sensitive impedance element series-connected to said photoelectromotive diode array, said light sensitive impedance element changing its impedance value according to the intensity of said optical signal from said light emitting element, wherein said light sensitive impedance element comes into a small impedance state when said optical signal from said light emitting element is strong and it comes into a large impedance state when said optical signal from said light emitting element is weak; at least one output MOSFET whose gate and source are connected to respective ends of the series-connected circuit comprised of said photoelectromotive diode array and said light sensitive impedance element; and a normally-ON drive transistor whose control electrode is connected to the node of said photoelectromotive diode array and said light sensitive impedance element, and whose one pair of conducting electrodes are connected to the gate and the source of said output MOSFET respectively. 2. A photo-coupler apparatus comprising:a light emitting element for emitting light by an input signal; a photoelectromotive diode array for generating photoelectromotive force by receiving an optical signal from said light emitting element; a light sensitive impedance element series-connected to said photoelectromotive diode array, said light sensitive impedance element changing its impedance value according to the intensity of said optical signal from said light emitting element, wherein said light sensitive impedance element comes into a small impedance state when said optical signal from said light emitting element is strong and it comes into a large impedance state when said optical signal from said light emitting element is weak; a zener diode parallel-connected with said light sensitive impedance element; at least one output MOSFET whose gate and source are connected to respective ends of the series-connected circuit comprised of said photoelectromotive diode array and said light sensitive impedance element; and a normally-ON drive transistor whose control electrode is connected to the node of said photoelectromotive diode array and said light sensitive impedance element, and whose one pair of conducting electrodes are connected to the gate and the source of said output MOSFET respectively. 3. A photo-coupler apparatus comprising:a light emitting element for emitting light by an input signal; a photoelectromotive diode array for generating photoelectromotive force by receiving an optical signal from said light emitting element; a light sensitive impedance element series-connected to said photoelectromotive diode array, said light sensitive impedance element changing its impedance value according to the intensity of said optical signal from said light emitting element; a normal diode array parallel-connected with said light sensitive impedance element; at least one output MOSFET whose gate and source are connected to respective ends of the series-connected circuit comprised of said photoelectromotive diode array and said light sensitive impedance element; and a normally-ON drive transistor whose control electrode is connected to the node of said photoelectromotive diode array and said light sensitive impedance element, and whose one pair of conducting electrodes are connected to the gate and the source of said output MOSFET respectively. 4. The photo-coupler apparatus according to claim 3, wherein said light sensitive impedance element comes into a small impedance state when said optical signal from said light emitting element is strong while it comes into a large impedance state when said optical signal from said light emitting element is weak. 5. The photo-coupler apparatus according to claim 1, 2, or 3, wherein said normally-ON drive transistor is a P-channel type or a N-channel type Junction FET. 6. The photo-coupler apparatus according to claim 1, 2, or 3, wherein said light sensitive impedance element, photoelectromotive diode array, output MOSFET, and drive transistor are integrated into one chip. 7. The photo-coupler apparatus according to claim 1, 2, or 3, wherein said light sensitive impedance element stays in a small resistance state for a certain time once said optical signal from said light emitting element has been interrupted. 8. The photo-coupler apparatus according to claim 1, 2, or 3, wherein another output MOSFET is further connected to said output MOSFET in the form of anti-series connection with source common so as to control an AC signal.

1993-12-03

en

1996-05-07

US-41449995-A

Filter device ABSTRACT A filter device containing cell masses and single cells is described. The device contains porous hollow fibers and hepatocytes entrapped within a contracted gel matrix. Portions of the research described herein were supported in part by grants from the National Institutes of Health. This is a continuation-in-part of application Ser. No. 08/376,095 filed 20 Jan. 1995, which is a continuation of application Ser. No. 07/864,893 filed 3 Apr. 1992, abandoned, which is a continuation-in-part of application Ser. No. 07/355,115 filed 18 May 1989, abandoned, which is a continuation-in-part of application Ser. No. 07/197,700 filed 23 May 1988, abandoned and of application Ser. No. 07/605,371 filed 29 Oct. 1990, abandoned. Those applications are incorporated by reference herein in entirety. BACKGROUND OF THE INVENTION Liver transplantation currently is the only mode of treatment for patients in acute fulminant hepatic failure who are not responding to supportive therapy (Starzl et al. "Liver Transplantation (1)" N Engl J Med (1989) 321:1092-1099; Langer and Vacanti "Tissue Engineering" Science (1993) 260:920-926). The need for an interim liver assist device as a bridge to transplantation for patients in hepatic failure has been well documented (Takahashi et al. "Artificial Liver: State of the Art" Dig Diseases Sci (1991) 36:1327-1340). With the development of an artificial liver, patients in hepatic failure may be supported until donor livers become available or until their own livers can regenerate. Such a device would alleviate the problem of scarcity of donor organs (Busuttil et al. "The First 100 Liver Transplants at UCLA" Ann Surg (1987) 206:387-402; Vacanti et al. "Liver Transplantation in Children: The Boston Center Experience in the First 30 Months" Transplant Proc (1987) 19:3261-3266.) and associated complications (Walvatne & Cerra "Hepatic Dysfunction in Multiple Organ Failure" In Multiple Organ Failure: Pathophysiology and Basic Concepts of Therapy, Dietch, E. A., Ed., (1990) pp. 241-260, Thieme Medical Publishers, New York; Shellman et al. "Prognosis of Patients with Cirrhosis and Chronic Liver Disease Admitted to the Medical Intensive Care Unit" Crit Care Med (1988) 16:671-678). Animal cells and genetically altered derivatives thereof often are cultivated in bioreactors for the continuous production of vaccines, monoclonal antibodies and pharmaceutic proteins, such as hormones, antigens, tissue type plasminogen activators and the like. The cells essentially are a system of catalysts and the medium supplies and removes the nutrients and growth inhibiting metabolites. To supply nutrients and remove metabolites, the medium in the bioreactor is changed either intermittently or continuously by fluid flow. However, because of relatively small size and small density difference when compared to the medium, cells inevitably are withdrawn when the medium is changed, resulting in a relatively low cell concentration within the bioreactor. As a result of the low cell concentration, the concentration of the desired cell product is low in the harvested medium. An ideal animal cell bioreactor would include three features: (1) cells would be retained in a viable state at high densities in the bioreactor apparatus as long as possible, with an almost infinite residence time; (2) high molecular weight compounds, including expensive growth factors and the desired cell products, would have a long but finite residence time within the bioreactor to allow for both efficient nutrient utilization by the growing cells and also the accumulation of cell products to a high concentration; and (3) low molecular weight compounds, including less expensive nutrients and inhibitory substances, should have a very short residence time within the bioreactor to reduce inhibition of cell growth, cell product formation and other cellular metabolic activities. The development of an artificial liver is a complex problem. Many prior attempts, such as plasmapheresis, charcoal and resin hemoperfusion and xenograft cross circulation, have failed. Unlike the heart that has one major physiologic function, the liver performs many complex tasks necessary for survival. Those tasks have been difficult to develop or maintain in mechanical systems. The liver is the metabolic factory required for the biotransformation of both endogenous and exogenous waste molecules and the synthesis of glucose, lipids and proteins, including albumin, enzymes, clotting factors and carrier molecules for trace elements. The liver maintains appropriate plasma concentrations of amino and fatty acids as well as detoxifying nitrogenous wastes, drugs and other chemicals. Waste products, such as bilirubin, are conjugated and excreted via the biliary tree. Hepatic protein synthesis and biotransformation vastly increase the complexity of hepatic support. Systems that employ hepatocytes to provide biochemical function are problematic because hepatocytes can be difficult to maintain in culture. Under standard conditions, non-transformed hepatocytes cultured on plastic lose gap junctions in about 12 to 24 hours; flatten, become agranular, lose all tissue specific functions in 3-5 days; and die within 1-2 weeks. (Reid & Jefferson "Culturing hepatocytes and other differentiated cells" Hepatology (1984) May-June; 4(3): 548-59; Warren et al. "Influence of medium composition on 7-alkoxycoumarin O-dealkylase activities of rat hepatocytes in primary maintenance culture" Zenobiotica (1988) 18(8):973-81). A solution to that problem is the use of transformed hepatocytes which can be grown much more easily. However, transformed hepatocytes often are considered a poor choice because even well-differentiated transformed cells show marked variations in tissue-specific function from the parent tissues. (Reid & Jefferson (1984) supra) Moreover, many cell lines are transformed by viruses. (Aden et al. "Controlled synthesis of HBsAg in a differentiated human liver carcinoma-derived cell line" Nature (1979) pp. 615-6; Knowles et al. "Human hepatocellular carcinoma cell lines secrete the major plasma proteins and hepatitis B surface antigen" Science (1980) 209:497-9). Those cell lines have the potential to transmit the transforming virus to the patient. As a result, it is doubtful that regulatory agencies would approve the use of transformed cells for humans, even if the risk of transmission were proven minimal. Many approaches to prolonging the viability and function of cultured hepatocytes and other differentiated cells have been investigated. Those approaches include adding hormones and growth factors to the culture media, adding extracellular matrix constituents and growing the hepatocytes in the presence of another cell type. Cells routinely used in co-culture work with hepatocytes are endothelial cells or hepatic nonparenchymal cells, such as Kupffer cells. The addition of corticosteroids to the incubation media has been shown to prolong survival of cultured hepatocytes and to maintain albumin synthesis, particularly in synergy with insulin. (Jefferson et al. "Post-transcriptional modulation of gene expression in cultured rat hepatocytes" Mol Cell Biol (1984) 4(9):1929-34; Dich et al. "Long-term culture of hepatocytes: effect of hormones on enzyme activities and metabolic capacity" Hepatology (1988) 8(1):39-45) DMSO (Dimethyl sulfoxide) and phenobarbital also are known to prolong hepatocyte viability and function. (Maher, J. J. "Primary hepatocyte culture: is it home away from home?" Hepatology (1988) 8(5):1162-6) Not all tissue-specific functions are supported equally, however. Insulin can promote some functions with an effect that varies with concentration. If only insulin is added to the medium, urea cycle enzyme expression is decreased. That negative effect can be counteracted by the addition of glucagon and dexamethasone. (Dich et al. (1988) supra) Hormonally-defined medium also can prolong hepatocyte function and viability. (Jefferson et al. (1984) supra) Using a serum-free hormonally-defined medium, good function in baboon hepatocytes has been shown for over 70 days. The medium consisted of epidermal growth factor (100 ng/ml), insulin (10 μg/ml), glucagon (4 mg/ml), albumin (0.5 mg/ml), linoleic acid (5 mg/ml), hydrocortisone (10-6 M), selenium (10-7 M), cholera toxin (2 ng/ml), glycyl-histidyl-lysine (20 ng/ml), transferrin (5 mg/ml), ethanolamine prolactin (10-6 M), (100 ng/ml), somatotropin (1 mg/ml) and thyrotropin releasing factor (10-6 M). (Lanford et al. "Analysis of plasma protein and lipoprotein synthesis in long-term primary cultures of baboon hepatocytes maintained in serum-free medium" In Vitro Cell Dev Biol (1989) 25(2):174-82) It now is clear that the extracellular matrix has considerable influence on cell function and survival. (Bissell & Aggeler "Dynamic reciprocity: How do extracellular matrix and hormones direct gene expression" Mechanisms of Signal Transduction by Hormones and Growth Factors Alan R. Liss, Inc. (1987) 251-62.3) Matrix elements have been shown to reduce or obviate the need for specific growth factors. Using extracted hepatic connective tissue, hepatocytes have been cultured for over 5 months and maintained albumin synthesis for at least 100 days. That extract represented approximately 1% of the liver by weight. One-third of the extract was composed of carbohydrates and noncollagenous proteins; the other two-thirds were collagens, 43% Type I, 43% Type III, and the remainder, an undefined mixture of others including Type IV. (Rojkind et al. "Connective tissue Biomatrix: Its Isolation and Utilization for Long-term Cultures of Normal Rat Hepatocytes" J Cell Biol (1980) 87:255-63) That mixture may not reflect accurately the local hepatocyte environment, the peri-sinusoidal space or Space of Disse. The presence of matrix in the Space of Disse has been controversial. Some researchers initially suggested that the peri-sinusoidal space was "empty". It now is appreciated that all of the major constituents of basement membrane are present in or around the Space of Disse. (Bissell & Choun "The role of extracellular matrix in normal liver" Scand J Gastroenterol (1988) 23(Suppl 151):1-7) Heparan sulfate proteoglycan binds both cell growth factors and cells. (Saksela et al. "Endothelial cell-derived heparan sulfate binds basic fibroblast growth factor and protects it from proteolytic degradation" J Cell Biol (1988) 107(2):743-51; Gordon et al. "Heparan sulfate is necessary for adhesive interactions between human early hemopoietic progenitor cells and the extracellular matrix of the marrow microenvironment" Leukemia (1988) 2(12):804-9) Heparan sulfate may effect directly the hepatocyte nucleus. (Ishihara et al. "Transport of heparan sulfate into the nuclei of hepatocytes" J Biol Chem (1986) 261(29):13575-80), Hepatocytes secrete relatively abundant quantities of heparan sulfate in culture. (Arenson et al. "Formation of extracellular matrix in normal rat liver: lipocytes as a major source of proteoglycan" Gastroenterology (1988) 95(2):441-7) Immunologic studies identified Type I collagen, Type III collagen, Type IV collagen, fibronectin and laminin in the Space of Disse. (Geerts et al. "Immunogold localization of procollagen III, fibronectin and heparan sulfate proteoglycan on ultrathin frozen sections of the normal rat liver". Histochemistry (1986) 84(4-6):355-62; Martinez-Hernandez, A. "The hepatic extracellular matrix. I. Electron immunohistochemical studies in normal rat liver" Lab Invest (1984) 51(1):57-74) There normally is little Type I collagen in the Space of Disse, although hepatocytes in culture show increasing Type I synthesis with de-differentiation, at the expense of Type III collagen synthesis. That effect is reversed with culture techniques that support tissue-specific hepatocyte activity. Hepatocytes also can be cultured on Matrigel™, a biomatrix produced by a sarcoma cell line (EHS). Matrigel™ contains Type IV collagen, laminin, entactin and heparan sulfate. On Matrigel™, hepatocytes maintain normal albumin synthesis for 21 days. (Bissell & Aggeler (1987) supra). Close duplication of the normal environment of the hepatocyte also has been attempted by culturing hepatocytes in a confluent monolayer on collagen. A second layer of Type I collagen is added to recreate the normal matrix "sandwich" formed on the "top" and on the "bottom" of the hepatocyte. That technique has shown significantly improved viability and function with albumin synthesis for more than 42 days. (Dunn et al. "Hepatocyte function and extracellular matrix geometry: long-term culture in a sandwich configuration" FASEB (1989) 3:174-7) The effect of various proteoglycans and glycosaminoglycans on gap junction protein synthesis and genetic expression also has been examined carefully. The most effective compounds were dermatan sulfate proteoglycan, chondroitin sulfate proteoglycan, and heparan. Heparan extracted from the liver was most effective. Lambda carrageenan, a seaweed extract, also was effective. (Spray et al. "Proteoglycans and Glycosaminoglycans Induce Gap Junction Synthesis and Function in Primary Liver Cultures" J Cell Biol (1987) 105:541-55) Finally, chitosan, a polysaccharide found in crustacean shells and fungal membranes, has been suggested as a factor that can mimic normal matrix and promote function and survival of cells. (Muzzarelli et al. "Biological activity of chitosan: ultrastructural study" Biomaterials (1988) 9(3):247-52; Scholz & Hu "A two compartment cell entrapment bioreactor with three different holding times for cells, high and low molecular weight compounds" Cytotechnology (1990) 4:127-137). Another successful technique for culturing differentiated liver cells involves co-culture with nonparenchymal cells. Recently, co-culture of hepatocytes on various endothelial lines was compared. Co-culture showed significantly improved albumin synthesis and maintenance of gap junctions. The cells were grown in the presence of insulin and dexamethasone. The addition of serum did not improve the results. The improved survival and function conferred by co-culture occurred only with cells in close proximity and was not transferred by cell supernatants. (Goulet et al. "Cellular interactions promote tissue-specific function, biomatrix deposition and junctional communication of primary cultured hepatocytes" Hepatology (1988) 8(5):1010-8). It still is controversial whether the beneficial effects of co-culture occur through matrix interactions or require cell-cell contact. There also is evidence that lipocytes play a key role in matrix production. Lipocytes are reported to be as numerous as Kupffer cells and have been suggested to produce the majority of Type I collagen, Type II collagen, Type IV collagen, laminin and proteoglycans, particularly dermatan sulfate proteoglycan and chondroitin sulfate proteoglycan. (Friedman et al. "Hepatic lipocytes: The principle collagen-producing cells of normal rat liver" PNAS (1985) 82:8681-5) It is of particular interest that those specific proteoglycans were those that best support gap junctions (Spray et al. (1987) supra). Many techniques of artificial support have been utilized over the past three and a half decades. Those include simple exchange transfusions (Lee & Tink "Exchange transfusion in hepatic coma: report of a case" The Med J Australia (1958) 11:40-42; Trey et al. "Treatment of hepatic coma by exchange blood transfusion" NEJM (1966) 274(9):473-81); plasmapheresis with plasma exchange (Sabin & Merritt "Treatment of hepatic coma in cirrhosis by plasmapheresis and plasma infusion [plasma exchange]" Annals of Internal Medicine (1968) 68(1):1-6); extracorporeal heterologous or homologous liver perfusion (Eisemann et al. "Heterologous liver perfusion in treatment of hepatic failure" Annals of Surgery (1965) 162(3):329-345; Sen et al. "Use of isolated perfused cadaveric liver in the management of hepatic failure" Surgery (1966) 59(5):774-781); cross-circulation (Burnell et al. "Acute hepatic coma treated by cross-circulation or exchange transfusions" NEJM (1967) 276(17):943-953); hemodialysis (Opolon et al. "Hepatic failure coma (HFC) treated by polyacrylonitrile membrane (PAN) hemodialysis (HD)" Trans ASAIO (1976) 22:701-710); activated charcoal hemoperfusion (Gazzard et al. "Charcoal haemoperfusion in the treatment of fulminant hepatic failure" Lancet i:1301-1307); and, more recently, bioartificial liver systems (BAL's) containing cultured hepatocytes. Examples of bioartificial liver systems currently being investigated for support of liver failure include extracorporeal bioreactors (Arnaout et al. "Development of bioartificial liver: bilirubin conjugation in Gunn rats" Journal of Surgical Research (1990) 48:379-382; Margulis et al. "Temporary organ substitution by hemoperfusion through suspense of active donor hepatocytes in a total complex of intensive therapy in patients with acute hepatic insufficiency" Resuscitation (1989) 18:85-94); implantable hepatocyte cultures, such as microencapsulated gel droplets (Cai et al. "Microencapsulated hepatocytes for bioartificial liver support" Artificial Organs (1988) 12(5):388-393) and spheroid aggregates (Saito et al. "Transplantation of spheroidal aggregate cultured hepatocytes into rat spleen" Transplantation Proceedings (1989) 21(1) :2374-77). Those bioartificial liver systems have the advantage of performing detoxification, synthesis and bioprocessing functions of the normal liver. Only a few extracorporeal bioreactors have been used in the clinical setting (Matsumura et al. "Hybrid bioartificial liver in hepatic failure: preliminary clinical report" Surgery (1987) 101(1):99-103; Margulis et al. (1989) supra). Implantable hepatocyte cultures remain clinically untested. The technique for hepatocyte entrapment within microencapsulated gel droplets (hepatocyte microencapsulation) is similar to the technique successfully used for pancreatic islet encapsulation (O'Shea & Sun "Encapsulation of rat islets of Langerhans prolongs xenograft survival in diabetic mice" Diabetes (1986) 35:943-46; Cai et al. (1988) supra). Microencapsulation allows nutrient diffusion to the hepatocytes and metabolite and synthetic production diffusion from the hepatocytes. Microencapsulation also provides intraperitoneal hepatocytes with "immuno-isolation" from the host defenses (Wong & Chang "The viability and regeneration of artificial cell microencapsulated rat hepatocyte xenograft transplants in mice" Biomat Art Cells Art Org (1988) 16(4):731-739). Plasma protein and albumin synthesis (Sun et al. "Microencapsulated hepatocytes as a bioartificial liver" Trans ASAIO (1986) 32:39-41; Cai et al. (1988) supra); cytochrome P450 activity and conjugation activity (Tompkins et al. "Enzymatic function of alginate immobilized rate hepatocytes" Biotechnol Bioeng (1988) 31:11-18); gluconeogenesis (Miura et al. "Liver functions in hepatocytes entrapped within calcium alginate" Ann NY Acad Sci (1988) 542:531-32); ureagenesis (Sun et al. "Microencapsulated hepatocytes: an in vitro and in vivo study" Biomat Art Cells Art Org (1987) 15:483-486); and hepatic stimulating substance production (Kashani & Chang "Release of hepatic stimulatory substance from cultures of free and microencapsulated hepatocytes: preliminary report" Biomat Art Cells Art Org (1988) 16(4):741-746) all have been reported for calcium alginate-entrapped hepatocytes. Aggregated hepatocytes have been proposed as a treatment means for fulminant hepatic failure. Multiple techniques exist for hepatocyte aggregation (Saito et al. "Transplantation of spheroidal aggregate cultured hepatocytes into rat spleen" Transplantation Proceedings (1989) 21(1):2374-77; Koide et al. "Continued high albumin production by multicellular spheroids of adult rat hepatocytes formed in the presence of liver-derived proteoglycans" Biochem Biophys Res Comm (1989) 161(1):385-91). Extracorporeal bioreactor designs for the purpose of artificial liver support have included perfusion of small liver cubes (Lie et al. "Successful treatment of hepatic coma by a new artificial liver device in the pig" Res Exp Med (1985) 185:483-494) dialysis against a hepatocyte suspension (Matsumura et al. (1987) supra; Margulis et al. (1989) supra); perfusion of multiple parallel plates (Uchino et al. "A hybrid bioartificial liver composed of multiplated hepatocyte monolayers" Trans ASAIO (1988) 34:972-977); and hollow fiber perfusion. Human studies using extracorporeal hepatocyte suspensions have been reported. The first clinical report of artificial liver support by dialysis against a hepatocyte suspension was released in 1987 (Matsumura et al. (1987) supra). The device consisted of a rabbit hepatocyte liquid suspension (1-2 liters) separated from patient blood by a cellulose acetate dialysis membrane. Each treatment used fresh hepatocytes during a single four to six hour dialysis (run). Multiple runs successfully reduced serum bilirubin and reversed metabolic encephalopathy in a single case. A controlled study from the USSR comparing dialysis against a hepatocyte suspension with standard medical therapy for support of acute liver failure was reported recently (Margulis et al. (1989) supra). The bioartificial device consisted of a small 20 ml cartridge filled with pig hepatocytes in liquid suspension, along with activated charcoal granules. The cartridge was perfused through a Scribner arteriovenous shunt access. Patients were treated daily for six hours. The hepatocyte suspension was changed hourly over each six hour treatment period. Improved survival was demonstrated in the treated group (63%) when compared with the standard medical therapy control group (41%). Culturing hepatocytes with a hollow fiber cartridge is another example of bioartificial liver support. Traditionally, hepatocytes are loaded in the extracapillary space of the hollow fiber cartridge, while medium, blood or plasma is perfused through the lumen of the hollow fibers. Cells may be free in suspension (Wolf & Munkelt "Bilirubin conjugation by an artificial liver composed of cultured cells and synthetic capillaries" Trans ASAIO (1975) 21:16-27); attached to walls (Hager et al. "A Prototype For A Hybrid Artificial Liver" Trans ASAIO (1978) 24:250-253); or attached to microcarriers which significantly increase the surface area within the extracapillary space (Arnaout et al. (1990) supra). Bilirubin uptake, conjugation and excretion by Reuber hepatoma cells within a hollow fiber cartridge was reported in 1975. (Wolf & Munkelt (1975) supra). Tumor cell suspensions were injected by syringe into the shell side of the compartment while bilirubin containing medium was perfused through the hollow fiber intraluminal space. That technique has not been reported clinically, possibly due to the risk of tumor seeding by hepatoma cells. Another hollow fiber device developed for liver support uses hepatocytes attached to microcarriers loaded into the extracapillary cavity of a hollow fiber cartridge. In that device, blood flows through semi-permeable hollow fibers allowing the exchange of small molecules. Using that system, increased conjugated bilirubin levels have been measured in the bile of glucuronosyl transferase deficient (Gunn) rats. (Arnaout et al. "Development of Bioartificial Liver: Bilirubin Conjugation in Gunn Rats" J Surg Research (1990) 48:379-82) Since the outer shell is not perfused, all oxygen and nutrients are provided by the patient blood stream. In addition, that system may require an intact in vivo biliary tree for the excretion of biliary and toxic wastes. However, for clinical applications, it is desirable to increase the liver-specific functions of the BAL, thereby requiring more cells or increasing the per cell liver-specific function. The former avenue generally is not considered because normal cells are difficult to obtain, the cells are difficult to maintain and the bioreactor cannot command a large blood volume during ex vivo therapy. Primary rat hepatocytes, when plated on some modified surfaces, form aggregates that exhibit enhanced per cell liver-specific functions (Koide et al. "Continued High Albumin Production by Multicellular Spheroids of Adult Rat Hepatocytes Formed in the Presence of Liver-Derived Proteoglycans" Biochem Biophys Res Commun (1989) 161:385-391; Tong et al. "Long-Term Culture of Adult Rat Hepatocyte Spheroids" Exp Cell Res (1992) 200:326-332). Freshly isolated rat hepatocytes, when plated between 30-80% confluency onto positively charged polystyrene surfaces (Koide et al. "Formation of Multicellular Spheroids Composed of Adult Rat Hepatocytes in Dishes with Positively Charged Surfaces and Under Other Nonadherent Environments" Exp Cell Res (1990) 186:227-35), initially spread out and seem to move randomly. After 48 hours, cell movement appears directional as cells begin to aggregate into multicellular islands which eventually shed off into suspension as freely suspended aggregates. Aggregates formed in that manner exhibit a uniform diameter of approximately 100 μm and are 6-8 cell layers thick. Reported systems for making aggregates include culture of aggregates in a polyurethane foam matrix in a packed bed culture system (Ijima et al. "Application of Three Dimensional Culture of Adult Rat Hepatocytes in PUF Pores for Artificial Liver Support System" In: Animal Cell Technology: Basic & Applied Aspects Murakami et al. Ed., (1992) pp 81-86, Kluwer Academic Publishers, The Hague, Netherlands), culture of aggregates in a tubular reactor packed with pyrex glass beads (Li et al. "Culturing of Primary Hepatocytes as Entrapped Aggregates in a Packed Bed Bioreactor: A Potential Bioartificial Liver" In Vitro Cell Dev Biol (1993) 29A:249-254), culture of calcium alginate-encapsulated aggregates in a spouted bed culture chamber (Takabatake et al. "Encapsulated Multicellular Spheroids of Rat Hepatocytes Produce Albumin and Urea in a Spouted Bed Circulating Culture System" Artif Organs (1991) 15:474-480; Koide et al. "Hepatocyte Spheroid: Differentiated Features and Potential Utilization for Bioreactor of Artificial Liver Support" Extended Abstract, Japanese Association of Animal Cell Technology Annual Meeting, Nov. 9-12, 1993, Nagoya, Japan) and collagen-entrapped aggregates inoculated into the extracapillary space of a hollow fiber bioreactor (Sakai and Suzuki "A Hollow Fiber Type Bioartificial Liver Using Hepatocyte Spheroids Entrapped in Collagen Gel" Extended Abstract, Japanese Association of Animal Cell Technology Annual Meeting, 1993, Nagoya, Japan). A common limitation of each of those systems is the low number of hepatocytes attainable for use in the bioreactor. Approximately 50 million through 75 million hepatocytes as aggregates were used in those studies. The aggregate formation process using stationary petri dishes or other surfaces is long and labor intensive. Aggregate formation occurs only within a narrow cell density range (approximately 3-8×104 cells/cm2). Of the cells initially plated, only 30-40% of the inoculated cells form aggregates after 2-3 days of culture. Thus, to supply 100 million hepatocytes as aggregates, an inoculum of approximately 300-400 million cells is required. Based on plating density requirements, that translates to a surface area of 8000 cm2 or 200 petri dishes of 60 mm diameter. Thus, the feasibility of employing reconstituted hepatocytes (aggregates) in a bioartificial liver application depends on the ability to engineer reconstituted hepatocyte formation at a quicker rate and a higher efficiency. The availability of a higher number of aggregates would enable maximization of viable cells in the BAL without detrimentally increasing the size of the device. SUMMARY OF INVENTION An object of the instant invention is to provide an artificial liver comprising hepatocytes formed into organoids to maximize per cell liver-specific functions. A combination of preformed organoids and dispersed hepatocytes are entrapped within a contracted matrix gel in a hollow fiber to allow perfusion by a luminal nutrient flow stream. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 depicts the degree of gel compaction when cells, organoids or a combination thereof are entrapped within. In the graph, the curve denoted with open squares represents 5×106 /ml dispersed cells; the filled squares represent 1×106 /ml dispersed cells; the open circles, 2.5×106 /ml cells in organoids and 2.5×106 /ml dispersed cells; the filled circles, 0.5×106 /ml each of cells in organoids and dispersed cells; the open triangles 5×106 /ml cells in organoids; and filled triangles 1×106 /ml cells in organoids. FIGS. 2A and 2B depict urea production by monolayer and collagen gel-entrapped cells and organoids. FIG. 2A relates to monolayer cultures and FIG. 2B relates to collagen-entrapped cells. The plots denoted by circles in both panels relate to organoids and the plots denoted by squares in both panels relate to single cells. FIG. 3 depicts the levels of albumin production by collagen-entrapped organoids and dispersed cells. In the graph, circles relate to organoids and squares to single cells. FIG. 4 depicts the level of gel contraction using organoids, cells and combinations thereof. The gel disc had a thickness of 1.3 mm. A million cells were incorporated into each disc. The open circles relate to organoids; the filled circles, dispersed cells; the triangles, a 2:1 ratio of cells in organoids to dispersed cells; and the squares, a 1:1 ratio of cells in organoids to dispersed cells. FIG. 5 depicts albumin production of collagen-entrapped aggregated and unaggregated cells. FIG. 6 depicts the lidocaine clearance rates of gel-entrapped cells and organoids. In the figure, the plot denoted by squares relates to organoids and that by triangles, dispersed cells. FIG. 7 depicts the albumin production rate of BAL's containing organoids or dispersed cells. The plot denoted by squares relates to organoids and that by triangles to dispersed cells. FIG. 8 depicts the urea generation rate for BAL's containing organoids or dispersed cells. The plot denoted by squares relates to organoids and that by triangles to dispersed cells. DETAILED DESCRIPTION OF THE INVENTION A bioreactor device suitable for the instant invention is set forth in copending application, U.S. Ser. No. 08/376,095 filed 20 Jan. 1995, herein incorporated by reference in entirety. A bioreactor according to the inventive principles of the instant invention generally would include two chambers within a housing means having a proximal end and distal end. The two chambers are generated by a porous membrane. In one chamber are the hepatocytes and in the other chamber would flow the blood, plasma or serum. In a preferred embodiment, the membrane is in the form or porous-walled hollow fibers with the hepatocytes contained in the lumen of the fibers. The preferred membrane selectively allows low and high molecular weight compounds, such as nutrients and cell products, to cross between the chamber containing the cells and the other chamber. The desired upper molecular weight limit of the membrane is variable and can be varied to suit a specific purpose. Thus, a suitable membrane for a BAL may be on the order of 100,000 to allow free passage of most sub-cellular molecules. Ultrafiltration membranes that could be used with a bioreactor system of the instant invention include those made from polysulfone, nylon, polypropylene, polyester/polycarbonate, ionically charged membranes, cellophane®, nitrocellulose, polyethylene and ceramics. A few commercial examples include polycarbonate and polyester Nucleopore® membrane filters from Nucleopore Corporation in Pleasanton, Calif.; polysulfone PTGC membranes from Millipore of Bedford, Mass.; and nitrocellulose Collodion® membranes from Schleicher and Schuell, Inc. in Keene, N.H. For the purposes of modifying a reactor to serve as a BAL, it is preferable to employ a hollow fiber bioreactor. A suitable hollow fiber assembly is the Amicon PN 5407 Model DH4 from Amicon, a division of W. R. Grace & Co. in Danvers, Mass., with the pressure control valve and filter frits removed. In that case the hollow fibers are constructed of the various porous membrane materials with the inner compartment of the fibers serving as the site where the organoids and cells are housed. An Amicon H1P3-100 hollow fiber membrane assembly having an upper molecular weight limit of approximately 100,000 can be used. The hollow fibers of that assembly are formed of polysulfone, although any suitable membrane composition as discussed above also may be employed successfully. Because a principle function of the instant device is to detoxify blood, plasma or serum, the pore size must be selected to enable passage of most known toxins into the hollow fibers. It is known that many toxins and metabolites are conjugated or attached to carrier molecules in the circulation. A common carrier molecule is albumin. For example, it is known that unconjugated bilirubin is carried by albumin. Thus, it is beneficial to have pores which would enable passage of molecules about the size of albumin, which has a molecular weight of about 70,000 through the walls of the fiber. The hollow fibers can be obtained commercially in a variety of lengths and diameters. Suitably, the fiber lengths are conformed to the size of the housing. Fiber diameter is selected to maximize the number of cells contained therein, to maximize the flow of nutrient medium to retain maximal cell viability, to maximize surface area within the fiber and on the outer surface of the fiber and to retain an adequate size to house organoids. Fibers having a diameter of up to about 1 mm are used routinely and a diameter of about 100 μm probably represents a practical lower limit for the size of the fibers. Fibers of more intermediate diameter can be used and it often is preferred to use fibers having a diameter of about 150-400 μm so as to maximize the number of fibers that can be maintained in the housing. Thus, fibers of about 200-250 μm also are suitable. A suitable hollow-fiber assembly has a housing having spaced end portions defining a chamber therebetween. The housing has a first and second fluid inlet means with the second fluid inlet means positioned generally toward the inside of first fluid inlet means. The housing also has a first and second fluid outlet means, with the second fluid outlet means positioned generally toward the inside of the first fluid outlet means. While the housing is generally cylindrical, shape is not so limited. Any housing which will house hollow fibers may be employed successfully. Within the housing is at least one selectively permeable hollow fiber, pervious to the passage of nutrients and cell products while substantially impervious to the passage of cells, extending the length of the housing. The hollow fiber divides the chamber into an intracapillary space within the hollow fiber and an extracapillary space outside the hollow fiber. The intracapillary space and extracapillary space communicate only through the walls of the hollow fiber. Preferably, the intracapillary space provides a cell chamber for cells entrapped in the chosen matrix and a secondary lumen for passage of nutrient medium while the extracapillary space provides space for the blood, plasma or serum to bathe the outer surface of the fibers. The roles may be reversed, if desired. Preferably, a plurality of fibers would be employed. The interior lumens of the hollow fibers are in flow communication with the first fluid inlet means and the first fluid outlet means. The extracapillary space is in flow communication with the second fluid inlet means and second fluid outlet means. A bioreactor apparatus using the principles of the instant invention provides high oxygen transfer to the entrapped cells to maintain cell viability within the bioreactor with a low shear flow. The results further demonstrate that rapid start-up of the bioreactor apparatus is possible as well as step changes from serum-containing medium to serum-free medium and in many cases even protein-free medium. A "step change" means to change instantaneously rather than gradually. Generally, the cell-biocompatible matrix or gel is formed when the chosen cells are mixed with a matrix precursor solution at lower temperatures (e.g., 0° C. to 30° C.), at lower pH values (e.g., 2 to 5.5), at both a lower temperature and a lower pH value, or in a solution of different ionic makeup. The chosen matrix precursor is preferably initially in a soluble form to create the cell suspension. The cell-matrix precursor suspension then is introduced into the cell chamber through an inlet means. When the pH, the temperature or ionic character or polymer chain interaction is changed from the initial value, polymerization or aggregation occurs with the resulting polymer chains forming insoluble aggregates (e.g., pH value increased to the range of 6.8 to 7.4, temperature increased to the range of 37° C. to 45° C.). Generally, the insoluble aggregates will aggregate further to form fibers. The fibers, in turn, entrap the cells creating what is referred to as the substantially insoluble, cell-biocompatible matrix. It is desired that the chosen matrix precursor have the ability to form rapidly a substantially insoluble, biocompatible matrix in situ to entrap uniformly the cells, before the cells settle. The chosen matrix precursor preferably should form the fibrous matrix on a physical or chemical change in the cell-matrix precursor suspension. Such a change could be the result of a shift in pH or temperature value, or both, addition of a comonomer or any other initiator of polymerization or cross-linking, or any combination of those methods. Depending on the chosen matrix precursor, the formed matrix could be the result of polymerization, aggregation, ionic complexation, hydrogen bonding or the like. For the sake of convenience, it should be understood that wherever the term polymer or aggregate is used to refer to the matrix construction, the matrix is not limited to compounds with those characteristics. Any biocompatible, substantially insoluble matrix that forms in situ and entraps cells, at least initially, is considered to be within the scope of the present invention. Likewise, the matrix precursor should be read to include, but not be limited to, all compounds which tend to polymerize or aggregate or associate or the like to form the matrix in situ. Due to contraction possibly caused by the living cells contained therewithin, the cell-biocompatible matrix will contract, sometimes to about one quarter of the original volume occupied by the mixture in a few hours or days. For the instant invention it is necessary for the cell-biocompatible matrix to contract within the fiber to provide a lumen therewithin for the passage of nutrients. A cell-matrix which contracts to approximately 90% of the original volume occupied by the mixture is desired. A cell-matrix which has contracted to approximately 75% of the original volume occupied is even better. A cell-matrix which has contracted to approximately 50% of the original volume is preferred even more. However, the most desirable cell-matrix will contract to approximately one-third of the original volume occupied by the mixture. One compound that has been found to form a particularly suitable matrix is collagen. Sterile, high purity native ateleopeptide collagen Type I is commercially available from Collagen Corporation in Palo Alto, Calif. under the trade name Vitrogen™ 100. Teleopeptide collagen Type I also has proven to be useful and is available in a relatively pure form from Gottefosse Corporation located in Elmsford, N.Y. under the trade name Pancogene S™. Whenever the term collagen is used in the instant application, it should be read to include any type of collagen or modified collagen which is at least partially insoluble under optimum cell culture conditions. For example, collagen may be modified according to the techniques of U.S. Pat. No. 4,559,304 to Kasai, et al., the disclosure of which is incorporated by reference herein. The collagen-cell solution is introduced into the fibers to set in situ by increasing the ambient temperature to greater than about 25° C., preferably about 35°-45° C., and ideally about 37°-43° C. A collagen-chitosan mixture also may be used. A suitable chitosan, which is a derivative of chitin in which many of the N-acetyl linkages have been hydrolysed to leave the free amine, can be obtained from Protan Labs of Redmond, Washington in a dry state under the label Ultrapure Chitosan. As in the case of collagen, it should be recognized that the chitosan also can be modified chemically and still be an effective means for forming the matrix. In addition, the in situ polymerization of a fibrinogen and thrombin mixture to form fibrin has been employed successfully. Other materials which would meet the requirements of this system include: (1) polyamines wherein the subunits which make up the polymer have a pKa value generally ranging from 7 to 10, such as collagen and chitosan. Such polyamines are soluble in a cell culture media at pH values generally in the range of 2 to 5.5 when in a protonated form and partially insoluble in a cell culture media at pH values generally ranging from 6.8 to 7.4 when in a partially unprotonated form; (2) a mixture of water soluble polyanionic polymers and polycationic polymers. This mixture would associate through ionic bonds and fall out of solution; and (3) polymers, such as cellulose ethers, which are soluble in a cell culture media temperatures ranging from 0° C. to 30° C. but insoluble in a cell culture media at higher temperatures, such as those generally ranging from 32° C. to 45° C. have also been contemplated. In operation, the chosen cell nutrient medium is pumped with a peristaltic pump, from a media reservoir through the first fluid inlet means and first medium channel(s) to the nutrient medium plate window(s). A suitable pump is a variable speed Masterflex Cat. No. 7533-30 with size 16 Masterflex silicone tubing from Cole Palmer in Chicago, Ill. Medium continues through the nutrient medium plate window(s) to the second medium channel(s) and subsequently out bioreactor through the first fluid outlet means. Hepatocytes can be obtained by any of a variety of art-recognized means. Gentle treatment of the organ and cells is recommended to enhance viability. For example, perfusion with a solution containing a digestive enzyme, such as collagenase, is a suitable method. The animal is anethesized and the hepatic vasculature isolated. The liver is perfused with a buffer, preferably a calcium-free buffer containing a divalent cation chelator to enhance replacement of blood in the organ and to begin dissolution of the intercellular matrix. The liver is excised and then perfused with a buffer containing collagenase. The capsule is compromised and the organ manipulated to release the cells. The cells are washed and viability assessed by standard methods, such as trypan blue exclusion. Organoids are obtained by taking the hepatocyte single cell suspension in a hormonally-defined serum-free medium containing insulin, dexamethasone, glucagon, epidermal growth factor, liver growth factor, transferrin, linoleic acid, copper, selenium and zinc. The cells are placed in a siliconized spinner flask and stirred at about 40-120 rpm and preferably about 70-90 rpm and more preferredly at 80 rpm in a humidified 5% CO2 environment. The medium can be changed after 24 hours and every 2-3 days thereafter. Generally, the dynamics of organoid formation are uniform across the species origin of the cells. However, it is notable that the time frame within which organoids form can vary from species to species. Usually, cells first amass in clumps of two's, three's, four's and the like. Then over time, the clumps become larger as either clumps coalesce or individual cells adhere to the larger clumps. Thus, at an early time point, organoids may be on the order of about 20-30 μm in diameter, at a next time point, the organoids may have increased in size to about 35-40 μm in diameter, to about 100-140 μm on a successive reading and so on. Organoids of about 150-300 μm in diameter are observed routinely. With respect to preferred sizes of organoids to be incorporated into the hollow fibers, it is noted that maximal viability may be ensured with smaller sized organoids, however it is desired that a maximal number of cells be contained in the bioreactor. Moreover, it is desired that the cells retain liver-specific functions and the size of the organoids may play a role in the retention of those desirable activities. The organoids, or hepatocyte cell masses, to be incorporated into the hollow fibers can range in size from about 30-300 μm in diameter. Certain occasions may command that the idealized size of the cell masses be on the order of about 35-150 μm in diameter to a more narrow range of about 40-70 μm in diameter. Preferably the hepatocytes are entrapped in an aqueous, porous gel, such as, alginate, collagen, agar, chitosan, fibrin and the like. A mixture of organoids and single cells are mixed together to attain the necessary contraction of the formed gel in the hollow fibers to form a "secondary lumen" or the "occluded lumen" of the fiber to enable passage of the nutrient medium. The ratio of organoids to single cells is optimized to assure adequate gel contraction with the maximal number of entrapped cells. A ratio of cells in organoids to single cells of 1:3 to 3:1 can be used. A preferred ratio of 1:2 to 2:1 is preferred. A ratio of 1:1 also can be used beneficially. The matrix-cell solution is infused into the fibers via the ports described hereinabove. The sizes of the organoids and the total number of cells to be contained in the fiber lumen are adjusted by manipulating the cell number in the matrix solution prior to gelation. The number of cells in organoids is assessed and that number is added to the number of single cells to obtain a total cell number. As indicated hereinabove, a goal is to obtain the maximal number of cells in the bioreactor to ensure efficient detoxification of the blood, serum or plasma. A suitable concentration of total number cells is on the order of about 5-40×106 cells per milliliter. A more suitable concentration is about 20-40 million cells per ml and an ideal concentration is about 30-35 million cells per ml. It should be made clear that from that idealized cell number, the number of cells found in organoids then is calculated based on the desired ratios of cells in organoids to single cells discussed hereinabove. Hence, when using a cell concentration of 30×106 cells/ml and a 1:1 ratio of organoids to single cells, 15×106 cells will be in organoids and the other half of the cells are single cells. By using the cell masses, organoids of the instant invention, which are produced at an accelerated rate by the method disclosed herein, it is possible to maximize and retain liver-specific function. By doing so, an enhanced bioreactor is obtained because the device per se can be reduced in size, that is the housing can be reduced in size, so as to minimize the need to have a large extracorporeal blood volume in the device. The instant invention is exemplified in the following non-limiting examples. EXAMPLE I Porcine Organoids Formed in a Stirred Vessel Exhibit Enhanced Liver Activities Porcine hepatocyte harvest Hepatocytes were harvested from 8-10 kg male pigs by a two-step in situ collagenase perfusion technique modified from the original method developed for rat hepatocytes by Seglen (Seglen, P. O. "Preparation of Isolated Rat Liver Cells" Meth Cell Biol (1976) 13:29-38). The porcine first was anesthetized with ketamine (100 mg/ml): rompun (100 mg/ml), 5 ml:1 ml, IM to allow for intubation and mechanical ventilation. The porcine then was anesthetized with isofluorane (1.5%) per endotracheal tube and paralyzed with succinylcholine (20 mg IV). The abdomen was entered through a bilateral subcostal chevron incision. The venous vascular supply to and from the liver was isolated completely and looped with ties. The hepatic artery, common bile duct, gastrohepatic omentum and phrenic veins were ligated. The portal vein was cannulated with pump tubing and perfusion was initiated at 300 ml/min with oxygenated perfusion solution I (Per I). Per I is a calcium-free solution with 143 mM sodium chloride, 6.7 mM potassium chloride, 10 mM hydroxyethylpiperazine-ethanesulfonic acid (HEPES)(Gibco, Grand Island, N.Y.) and 1 g/l ethylene glycol-bis-aminoethyl ether (EGTA), at pH 7.40. The suprahepatic and infrahepatic vena cavae were ligated and a vent was made in the infrahepatic cava to modulate perfusion back pressure. The liver was excised, placed in a large sterile basin and perfused at 300 ml/min with oxygenated perfusion solution II (Per II). Per II consisted of 100 mM HEPES, 67 mM sodium chloride, 6.7 mM potassium chloride, 4.8 mM calcium chloride, 1% (v/v) bovine albumin and 1 g/l collagenase-D (Boehringer-Mannheim, Indianapolis, Ind.), pH 7.6. After 20-30 min, on visual and palpable evidence of the liver dissolving, the capsule was broken and the liver substance was raked and irrigated with cold Williams' E medium (Gibco) supplemented with 15 mM HEPES, 0.2 U/ml insulin (Lilly), 2 mM L-glutamine, 100 U/ml penicillin and 100 μg/ml streptomycin. The released cells were filtered through nylon mesh with 100 μm openings and resuspended in fresh Williams' E medium. Viability was assessed by trypan blue exclusion. Formation of pig hepatocyte organoids in a stirred vessel Isolated pig hepatocytes were resuspended in hormonally-defined culture medium, referred to as LTE medium, at a concentration of 0.5-1×106 cells/ml. The medium was a modification of the serum-free medium of Enat et al. (Enat et al. "Hepatocyte Proliferation In Vitro: Its Dependence on the Use of Serum-Free Hormonally Defined Medium and Substrata of Extracellular Matrix" Proc Natl Acad Sci USA (1984) 81:1411-1415) containing Williams' E basal medium supplemented with 100 units/ml penicillin, 100 μg/ml streptomycin, 0.2 units/ml insulin (Lilly Co., Indianapolis, Ind.), 1 nmole/ml dexamethasone, 4 ng/ml glucagon, 25 μg/ml EGF, 20 ng/ml liver growth factor, 6.25 μg/ml transferrin, 50 ng/ml linoleic acid, 500 μg/ml albumin, 0.1 μM CuSO4 .5H2 O, 3 nM H2 SeO3, 50 pM ZnSO4.7H2 O and 15 mM HEPES (Gibco) at pH 7.4. All the medium supplements were from Sigma unless otherwise specified. The cell suspension was placed into 250 ml siliconized spinner flasks and stirred at 80 rpm by a suspended magnetic stir bar in a humidified 5% CO2 incubator at 37° C. Medium was changed 24 hr after cell inoculation and every 2-3 days thereafter by stopping agitation, allowing gravity sedimentation of the organoids, followed by aspiration of the spent medium and replacement with fresh medium. Hepatocytes cultured in stirred conditions form organoids within 24 hr. During the formation period, cells first agglomerated to form multicellular aggregates of irregular shape and "bumpy" boundaries; individual cells still were discernible. Subsequent rearrangement and compaction of cell aggregates gave rise to structures with relatively smooth, undulating outer surfaces and individual cells at that time were indistinguishable from each other. By 24 hr, almost all aggregated cells were in the form of organoids. The diameter of organoids was assessed under an inverted microscope using a 10× ocular lens equipped with a vernier scale. Only particles above 30 μm in diameter were counted. The average of lengths along two perpendicular axes of the organoid was defined as the organoid diameter. Between 80-100 were evaluated to obtain representative average diameters. Organoids grew in size from 40-70 μm in diameter on the first day to 100-140 μm after five days in culture. For comparison, monolayer cultures also were performed. Freshly isolated hepatocyte suspensions (5×105 cells/ml) in LTE medium were used to inoculate 12-well tissue culture polystyrene plates (Falcon Multiwell, Becton Dickinson, Franklin Lakes, N.J.) at 2 ml/well. Culture medium was replaced daily with fresh medium, while the spent medium was collected and stored frozen at -20° C. until assayed. No organoids were formed during the observation period, although organoids will form on prolonged culture. Ultrastructure of organoid formed under stirred conditions resemble those formed on surfaces Scanning electron microscopy of organoids at five days in culture showed that most were relatively spherical except for some dumbbell-shaped, ones probably formed by coalescence of two organoids. At a higher magnification extensive cell-cell contact, numerous microvilli and small (2-4 μm) holes on the surface of the organoid can be seen. Such holes frequently were found at contact points of three cells. One might speculate that those pores on the organoid surface are localized in areas of junction between adjacent cells and are surface openings of differentiated bile canaliculus-like structures. Transmission electron microscopy of hepatocytes in organoids exhibited extensive cell-cell contact and nuclei of round or oval shape. Numerous mitochondria and lipid droplets of various sizes were observed in the cytoplasm of several cells. Morphologic characteristics predominant in organoids are junctional complexes, such as desmosomes, and bile canaliculus-like structures between hepatocytes. Continuous ductular structures of approximately 0.1 μm in diameter were distributed throughout the organoid 15 and can be seen to open as pores on the organoid surface. Numerous microvilli protruded into the structures. Organoids formed under stirred conditions appear structurally identical to those formed in petri dishes. Liver-specific functions of organoids formed under stirred conditions Ureagenesis Urea production by hepatocytes cultivated as monolayers and as organoids was compared using known techniques. The number of hepatocytes inoculated per unit volume of medium was the same in both cases. After measuring urea concentration for each time point, the daily production of urea was calculated. The rate of urea production divided by the initial hepatocyte concentration was taken as the specific urea production rate. Specific productivity in both cultures increased for the first three days and then gradually decreased. Hepatocytes cultured as free organoids were two times more active in urea production than cells grown as monolayers on tissue culture plates. Albumin production Albumin synthesis by organoids in spinner flasks and cells cultivated as monolayers was measured using known techniques, such as by ELISA or RIA, and expressed as cumulative values over seven days. Specific albumin synthesis rates were determined by a linear regression fit of the data. The albumin production rate for organoid and monolayer cultures were determined to be 50 μg/106 cells/day and 14 μg/106 cells/day, respectively. Organoids were at least three times more active than monolayers in producing albumin. Lidocaine metabolism The cytochrome P-450 function of hepatocyte organoids entrapped in collagen was evaluated by monitoring lidocaine metabolism using known techniques. Disappearance of exogenously added lidocaine alone was not a sufficient representation of P-450 activity, as the drug might be taken up by the hepatocytes without further biotransformation. Thus, production of lidocaine metabolites, e.g. monoethylglycinexylidide (MEGX), in addition to lidocaine clearance, were measured, using known techniques, to validate the quantification of P-450. Lidocaine clearance remained relatively constant at about 28 μg/106 cells/day over a 21-day period. MEGX-specific production also was maintained relatively constant at a rate of approximately 1.2 μg/106 cells/day, demonstrating the continuous function of the cytochrome P-450 enzyme system. 4-Methylumbelliferone (4-MU) conjugation The ability of hepatocyte organoids entrapped in collagen gel to conjugate was examined by assessing 4-MU metabolism using known techniques. 4-MU concentration decreased from 65 μM to below 0.1 μM within 24 hrs. The glucuronidated metabolite, 4-MUG, appeared in the culture medium. High glucuronidation activity was maintained in culture throughout the 21-day period. The sulfated 4-MU metabolite (4-MUS) could not be detected at a sensitivity of 1 μM. The activity represents the ability of pig hepatocyte organoids to carry out phase II metabolism for long time periods while entrapped in collagen gel. EXAMPLE II Rat Organoids Formed in a Stirred Vessel Exhibit Enhanced Liver Activities Rat hepatocyte harvest Hepatocytes were harvested from 4-6 week old male Sprague-Dawley rats by a modified two-step in situ collagenase perfusion technique (Seglen, P.O. (1976) supra; Nyberg et al. "Primary Culture of Rat Hepatocytes Entrapped in Cylindrical Collagen Gels: An In Vitro System With Application to the Bioartificial Liver" Cytotechnology (1992) 10:205-215). Post harvest hepatocyte viability ranged from 85-90% based on trypan blue exclusion. Formation of rat hepatocytes organoids in a stirred vessel Freshly harvested dispersed rat hepatocytes were inoculated into 250 ml siliconized spinner vessels to a final density of 0.3-1.0×106 cells/ml in 100 ml LTE medium, identical to that used for formation of pig hepatocyte organoids in spinner vessels. The medium is different from that used for rat hepatocyte organoid formation in petri dishes. The vessels were stirred with a suspended magnetic stir bar at 100 rpm in a humidified 5% CO2 incubator at 37° C. Medium was exchanged every 3-4 days by halting agitation to allow gravity sedimentation of organoids, followed by aspiration of spent medium and replacement with fresh medium. Rat hepatocytes cultured in stirred conditions formed organoids within 72 hrs after inoculation. During the first 8 hr period, cells were observed to form mostly doublets and triplets. After 24 hrs, cells agglomerated into masses of over 30 cells. Subsequent rearrangement and compaction of cells gave rise to a population of spherical cell structures, or organoids, which displayed relatively uniform diameter of 100-140 μm and smooth outer surfaces. To evaluate the efficiency of organoid formation, viability of cell suspensions during the formation period was determined. Single cells and cells in grouped masses that appeared blue under trypan blue exclusion were considered nonviable and unable to participate in organoid formation. It was assumed that only viable cells can form organoids. At each sampling point, 2.5 ml cell suspensions were placed into 15 ml centrifuge tubes and separated by gravity sedimentation into two fractions. The cell aggregate fraction consisted mainly of organoids and cell aggregates that would settle within the first 2 minutes to the bottom of the 15 ml centrifuge tube. That fraction was resuspended in phosphate-buffered saline solution, sonicated and stored at -20° C. until the assay for total protein. The supernatant fraction contained the culture medium and most of the nonviable and unaggregated cells that had not settled within the first two minutes after sampling. All fractions were stored at -20° C. until liver-specific function assays were performed. By 72 hrs, nearly all single cells in the spinner vessel were nonviable and all organoids appeared viable, based on fluorescence staining with ethidium bromide and fluorescein diacetate. Ethidium bromide stains nuclei of nonviable cells an orange-red and fluorescein diacetate stains cytoplasm of viable cells green. Determining the accumulation of nonviable cells and then performing a total cell balance around the vessel indicates that approximately 50-80% of inoculated cells formed into organoids. Consistently, the fraction of total protein in the organoid and aggregated cell fraction also was approximately 50-80% of the total protein content of the initial inoculum. Ultrastructure of organoids formed under stirred conditions resemble those formed on surfaces Scanning electron microscopy indicates that organoids ranged in diameter of about 50-200 μm but the majority were of about a uniform size of about 120 μm in diameter and spherical in shape. Individual cells within the organoids were indistinguishable. At a higher magnification, extensive cell-cell contact, numerous microvilli and small pores apparently corresponding to bile canalicular-like structures, can be seen on the surface of the organoid. Transmission microscopy shows clear evidence of gap junctions between cells and an extensive network of microvilli-lined bile canalicular-like channels. The cytoarchitecture and ultrastructure of organoids appear to mimic that of an in vivo liver lobule. Electron microscopy indicates that organoids formed in a spinner flask to be structurally similar to organoids formed on flat surfaces. Liver-specific functions of organoids formed under stirred conditions Ureagenesis After measuring urea concentrations, the daily production of urea by rat organoids in spinner cultures was calculated. The rate of urea production divided by the initial hepatocyte concentration was taken as the specific urea production rate. Specific productivity decreased in the first 72 hrs, presumably due to 50% loss of viability during organoid formation. After organoid formation, the specific rate held steady at approximately 24 μg/106 cells/day. By normalizing the production rate to total protein, specific productivity was approximately 120 μg/mg protein/day. Albumin synthesis Albumin concentrations in spinner flasks were measured and cumulative values were determined for seven days. Specific albumin synthesis rates were determined by linear regression fit of the data. The albumin synthesis rate for organoids was 28 μg/106 cells/day. Specific synthesis rates of organoids formed on petri dishes were similar to that of organoids formed in spinner cultures. EXAMPLE III Collagen-entrapped Porcine Organoids From Stirred cultures Collagen gel contraction The observation of gel contraction is important to the application of organoids in the BAL system, since gel contraction is necessary for intraluminal perfusion of culture medium to the hepatocytes entrapped in a hollow fiber bioreactor. To study the rate of gel contraction, both organoids and dispersed hepatocytes were entrapped in disc-shaped collagen gels of 22 mm diameter and approximately 1.3 mm thickness. Organoids were obtained from a 6 day spinner culture whereas the dispersed cells were used immediately after a separate hepatocyte harvest. The gel entrapment was performed by suspending cells in a collagen mixture consisting of 3:1 (v/v) mixture of Vitrogen 100 and four-fold concentrated Williams' E media adjusted to pH 7.4 and then plating the suspension into a 12 well-plate at 0.5 ml/well. The six conditions studied were: (1) 1×106 cells as organoids per ml collagen mixture, (2) 1×106 dispersed cells per ml collagen mixture, (3) 0.5×106 cells as organoids and 0.5×106 dispersed cells per ml of collagen mixture, (4) 5×106 cells as organoids per ml collagen mixture, (5) 5×106 dispersed cells per ml collagen mixture, (6) 2.5×106 cells as organoids and 2.5×106 dispersed cells per ml of collagen mixture. As a control, hepatocytes were killed by exposure to 50% ethanol for 15 minutes before collagen entrapment. The number of cells as organoids was estimated based on total protein per ml in the 6-day spinner culture. After incubating at 37° C. for 20 minutes the gel was formed. Subsequently, 1 ml of LTE medium was added to each well, and the gels were dislodged from the bottom of the plate to allow medium to reach the bottom of the gel. Gel diameter was measured with a ruler along two perpendicular axes for each gel. Each data point in FIG. 1 represents the average of triplicate measurements. The results demonstrate that viable hepatocytes are required for collagen gel contraction. Both organoid and dispersed cells were able to contract collagen gel. However, the rate of gel contraction by dispersed hepatocytes is higher than that by hepatocytes entrapped as organoids. The rate of contraction by a combination of both single cells and organoids falls in between the rates of those entrapped separately. Contraction appears to be affected by cell concentration (Scholtz & Hu Cytotechnology (1990) 4:127-137; Nyberg et al. Biotechnol Bioeng (1993) 41:194-203) as the extent of contraction was higher in discs with a denser cell concentration. Contraction also is expected to be affected by the distribution of cells in the gel and may attribute to the difference in the contraction rate. Liver-specific functions of collagen gel-entrapped organoids Ureagenesis Both dispersed cells and organoids were entrapped separately in collagen gel disks at the same cell concentration, submerged into medium and cultivated in 12-well plates. Comparison of the two culture systems indicate that urea production was higher in the organoid culture after collagen entrapment. Furthermore, urea production by both collagen-entrapped organoids and dispersed cells was more stable than those in free suspension or as a monolayer. After an initial increase in activity in the first three days, the urea production rate decreased to a level similar to the first day and remained relatively unchanged until day 21. Entrapment of organoids and unaggregated cells in collagen gels thus extended that activity (FIG. 2). Albumin production Albumin production by collagen-entrapped organoids and dispersed hepatocytes was measured for 21 days. The specific activities were calculated and are shown in FIG. 3. After an initial period of increasing activity, the samples stabilized at approximately 50 μg/106 cells/day and 18 μg/106 cells/day, respectively. The levels were maintained for at least 21 days. The albumin synthetic activity of collagen-entrapped organoids was not significantly different from that in free-suspension or in monolayers. That production level is similar to the in vivo albumin production reported for human liver (Peters, P. "Proteins and Plasma Protein Metabolism" In Molecular and Cell Biology of the Liver 9 pp. 31-64 LeBouton, AV. (1993) Ed. CRC Press, USA). EXAMPLE IV Collagen-entrapped Rat Hepatocyte Organoids Collagen Gel Contraction Rat hepatocyte organoids from a 48 hr spinner culture and freshly harvested rat hepatocytes were mixed at various ratios and entrapped in collagen discs that were 22 mm in diameter and approximately 1.3 mm in thickness. The gel entrapment was performed by suspending cells in a 3:1 (v/v) mixture of Vitrogen 100 and four-fold concentrated Williams' E media adjusted to pH 7.4 and then plating the cell-collagen mixture into a 12-well plate at 0.5 ml/well. The four conditions studied were: (1) organoids at 106 cells/ml without dispersed cells, (2) organoids and dispersed cells both at 106 cells/ml, (3) organoids at 106 cells/ml and dispersed cells at 0.5×106 cells/ml, (4)dispersed cells at 106 cells/mi. After incubating at 37° C. for 20 minutes the gel was formed. Subsequently, 1 ml of LTE medium was added to each well and the gels were dislodged from the bottom of the plate to allow medium to reach the bottom of the gel. Gel diameter was measured with a ruler along two perpendicular axes for each gel. Each data point in FIG. 4 represents the average of triplicate measurements. Without the addition of dispersed cells the gel containing organoid contracted only to a small degree. The presence of dispersed cells in the gel facilitated the contraction. The final diameter was about 30% smaller than at the beginning. Liver-specific functions of collagen gel-entrapped organoids formed on petri dishes Albumin synthesis Falcon Primaria culture dishes (60×15 mm) were plated with harvested freshly rat hepatocytes at 1.2×106 cells/plate and incubated in 5 ml organoid medium at 37° C. in a 5% CO2 humidified incubator. The medium used for preparation of organoids on Primaria petri dishes consisted of Williams' E medium (Gibco Laboratories, Grand Island, N.Y.) supplemented with 0.2 U/ml bovine insulin (Lilly Research Laboratories, Indianapolis, Ind.), 2 mM L-glutamine, 15 mM N-2-hydroxyethylpiperazine-N'-2-ethane sulfonic acid (HEPES), 100 U/L penicillin and 100 mg/L streptomycin (Gibco Laboratories) with an additional 50 ng/ml epidermal growth factor (EGF), 50 ng/ml linoleic acid, 0.1 μM CuSO4.5H2 O, 3 nM H2 SeO3 and 50 pM ZnSO4.7H2 O (Sigma Chemical Company, St. Louis, Mo.). Organoid formation was observed by day 4. The cellular contents of each petri dish, which contained a combination of unaggregated cells, clumped cells and organoids, were removed be gently pipetting. The contents of each plate were withdrawn into a 10 ml pipet and allowed to settle by gravity for 1 minute. The bottom one-fourth of each sample, consisting of mostly organoids and aggregated cells, was considered the organoid fraction. The top three-fourths, consisting of mostly unaggregated cells, was considered the dispersed cell fraction. Based on total protein content, equal numbers of hepatocytes in the organoid fractions and the dispersed cell fraction were entrapped into cylindrical collagen gels and incubated in fresh organoid medium. An unseparated cell suspension, consisting of a mixture of both aggregated and unaggregated cells also was collagen-entrapped into cylindrical gels 4.5 days after plating. Medium from the three different conditions were collected 7 days after plating, or 2.5 days after entrapment, and analyzed for albumin concentration. The results are shown in FIG. 5. The data were normalized to the total cellular protein present in each culture initially. Approximately two-fold higher activity of albumin synthesis was observed for the collagen-entrapped organoid culture as compared to the collagen-entrapped dispersed cell culture. The contributions from the two cell fractions approximately equaled the level of albumin produced by the unseparated cell mixture. The three collagen-entrapment cultures were also compared to cells which had formed organoids and that had been maintained on Primaria dishes for the duration of the same experiment. In accordance with the collagen entrapment cultures, the dishes were refed with fresh organoid medium 4.5 days after modulation and albumin synthesis was measured on incubation to 7 days. Results indicate that even on entrapment in collagen gel, the unseparated cell entrapment culture was able to maintain a high level of albumin synthesis. The mixture of organoids and unaggregated cells which had been maintained in petri dishes showed comparable albumin synthesis levels. Lidocaine metabolism Lidocaine clearance rates were measured as an indicator of P-450 enzyme activity. Both organoid and dispersed-cell fractions from a 4.5 day petri dish culture were entrapped in cylindrical collagen gels at approximately equal amounts of total protein. Single cells entrapped into cylindrical collagen gels immediately after rat harvest also were included in the experiment as a control. The cylindrical gels were placed into wells holding 2 ml prewarmed organoid media containing 12 μg/ml lidocaine. In the subsequent five days, the spent medium was collected and replaced daily with fresh medium. The collected samples were analyzed for lidocaine clearance. By correlating cell number to total protein content, an average cellular protein content of 2.0 mg/cell was obtained and used to determine a specific lidocaine clearance rate. On entrapment into cylindrical collagen gels, the organoid and dispersed-cell fractions exhibited an average clearance rate of 6.2±0.5 pg/cell/h and 3.2±0.4 pg/cell/h, respectively (FIG. 6). The rate obtained in the organoid entrapped cylindrical collagen gels is approximately two-fold higher than the dispersed cell-entrapped cultures and more than three-fold higher than the rate of 1.7±0.2 pg/cell by the control culture. The rate of the control culture is in good agreement with a previously reported specific clearance rate of 2.1±0.2 pg/cell/h for static cultures of single cell hepatocytes entrapped in collagen. Ultrastructure of entrapped organoids Organoids were cultivated on Primaria dishes for 4.5 days and entrapped in collagen. The collagen-entrapped organoids were cultured for two days in organoid medium, then fixed and stained for microscopic observation. Scanning electron microscopy showed that individual cells within the organoid could not be distinguished. The overall structure of organoids remained intact after two days entrapment in collagen. When viewed under an inverted microscope, the collagen gels appeared contracted, presumably because unaggregated hepatocytes, which could not be completely separated from organoids prior to entrapment, are able to contract collagen fibers. Similar to organoids in petri dishes, organoids entrapped in collagen appear to exhibit extensive cell-cell contact, abundant microvilli and small 2-4 μm openings on the surface of the entrapped organoids. The hole or pore structures, localized around cell junctions, may indicate differentiated and polarized cellular morphology of hepatocytes in organoids. Transmission electron micrographs of collagen-entrapped organoids indicate an ultrastructure similar to that observed for organoids in petri dishes. Hepatocytes on the outermost layer are flattened, more epithelial in morphology and have a low cytoplasmic volume with large nuclei. The cells comprising the interior of the organoid are cuboidal and have smaller-sized nuclei with a larger cytoplasmic volume. Cell membranes and perinuclear structures remained intact; mitochondria with matricular bodies, peroxizomes, lipid droplets, glycogen granules, intact golgi apparatus and decorated rough endoplasmic reticulum were all visible. The extensive network of bile canaliculus-like structures between hepatocytes was maintained. The organization of hepatocytes within collagen-entrapped organoids was similar to that within suspended organoids. One striking difference between organoids in petri dishes and those entrapped in collagen is that the outermost hepatocytes of the latter are covered extensively by microvilli-like projections. In organoids maintained on petri dishes, surface microvilli on the outer layer of cells were less numerous and usually were localized to areas in and around the junction between adjacent hepatocytes. EXAMPLE V Bioartificial Liver (BAL) A hollow fiber bioreactor can be used as a bioartificial liver by maintaining matrix-entrapped hepatocytes and hepatocyte organoids within the fibers, and perfusing a sustaining nutrient medium through the lumen along the space formed by matrix contraction, and passing blood around the fibers in the extracapillary space. Thus, the stream of blood, serum or plasma to be detoxified flows through the shell side. Rather than residing in the extracapillary shell space, cells, such as hepatocytes, are within the hollow fiber lumen, entrapped in a gel matrix. That configuration is accomplished by first suspending hepatocytes in a solution of collagen or a mixture of collagen and extracellular matrix components. The pH then is adjusted to 7.4 and the cell suspension inoculated into the lumen of the hollow fiber. A temperature change from 4° C. to 37° C. induces collagen fiber formation. That results in cell entrapment in an insoluble fibrous and highly porous cylindrical gel. After inoculation, the cross-sectional area of the gel-matrix cylinder can contract as much as 75%. That permits perfusion of the hollow fiber lumen even after it had been filled initially with the gel matrix. Molecular exchange occurs through the pores in the hollow fiber. Media with high molecular weight constituents flows through the hollow fiber containing a contracted core of hepatocytes embedded in a biomatrix through the hollow fiber inlet to the hollow fiber outlet. The technique has been used with multiple cell lines including, Chinese hamster ovary cells, Hep2, HepG2, Vero, 293 cells and normal diploid human liver cells. Study of a hematoxylin and eosin (H & E) stained thin section of human hepatoblastoma (HepG2) cells within a contracted gel matrix after 7 days showed the tissue density and cytoarchitecture closely resemble in vivo histology. The bioreactor offers distinct advantages over other configurations. Cells can be cultured at density close to that of tissue. At high density, cells occupy much less space, thus reducing the size of the bioreactor. Cells also obtain the benefits of close contact with minimal oxygen and nutrient limitations. Mammalian cells, at high density, may better preserve tissue specific function. The bioreactor configuration also allows manipulation of the hepatocytes' local environment. Matrix constituents that support differentiated hepatocyte function can be incorporated into the gel. The ability to perfuse the inner lumen provides high molecular weight growth factors at high concentrations. Another advantage of such a system is that different cell types can be co-entrapped in the gel to provide possible synergistic effects which may improve tissue specific function. This invention is thus capable of incorporating many factors (medium, gel matrix, co-culture, high cell density) necessary or beneficial to sustain liver-specific functions. It can be used as a bioartificial liver to support patients in liver failure. EXAMPLE VI Collagen-entrapped Porcine Organoid BAL A polysulfone hollow fiber cartridge (H1P3-100, Amicon, Danvers, Mass.) with a nominal molecular weight cut-off (MWCO) of 100 kiloDaltons (kD), an inner diameter of 1.1 mm and a total luminal volume of 10 ml was used as the BAL. The hollow fiber cartridge was autoclaved while immersed in distilled water for 30 minutes at 121° C. Other parts of the cultureware, including the oxygenator, media reservoir, pH probe and dissolved oxygen probe, were sterilized separately. The whole setup was assembled aseptically. The bioreactor was set up in a hollow fiber cell culture incubator, Acusyst Maximizer-1000 (Cellex Biosciences Inc., Coon Rapids, Minn.), which was microprocessor-controlled to maintain pH and dissolved oxygen by gas blending. Freshly harvested primary pig hepatocytes were inoculated into spinner cultures at 1×106 cell/ml in LTE medium. After 24h, approximately 95% of cells had formed into organoids, while the remaining 5% remained suspended as single cells. Most of the single cells still were viable, as seen by ethidium bromide/fluorescein diacetate dual fluorescence viability staining. At the time, a total of 120 ml were removed from spinner vessels, aliquoted into 50 ml centrifuge tubes and centrifuged (34 g, 2 min) to a soft pellet. After aspirating the supernatant, the pellet then was resuspended into a pre-mixed collagen solution. The solution was prepared by mixing at 4° C. 15 ml Vitrogen, a type I collagen, and 5 ml four-fold concentrated Williams' E medium. The pH of the mixture was adjusted to 7.4 by drop-wise addition of sterile 1 N sodium hydroxide. After suspending the organoid pellet the collagen solution, the cell-collagen mixture was injected slowly into the lumen space of the hollow fiber cartridge. A total of approximately 10 ml of solution was injected into the lumen space, or approximately 60×106 cells. Before inserting the cartridge into the cultureware, the entire cartridge was placed first in a 37° C. incubator for 10 minutes to allow the collagen mixture to gel. Approximately 400 ml prewarmed LTE media spiked with 4-methylumbelliferone (4-MU) were recirculated at 20 ml/min. Lumen perfusion at 9 ml/hr with medium alone was initiated after 24 hours. Medium from the intraluminal outflow was discarded after one pass. Every three days, medium from the extracapillary circuit was drained and replenished with fresh medium containing 12 μg/ml 4-MU. Samples were drawn from sterile septa on the extracapillary circuit and lumen outlets and stored at -20° C. until measurement of albumin, urea, 4-MU and metabolites was conducted. Lidocaine was added along with 4-MU, but due to adsorption of exogenous lidocaine to the cultureware, assessment of lidocaine clearance by cells could not be obtained readily. Liver-specific functions higher in organoid-entrapped BAL than dispersed-cell BAL Albumin synthesis Albumin synthesis profiles were obtained for the extracapillary space and lumen outflow for both organoid-entrapped and dispersed-cell entrapped BAL's. A material balance taken around the hollow fiber bioreactor was performed to obtain a cumulative total rate of 0.25 mg/day for the organoid-entrapped BAL and 0.15 mg/day for the dispersed-cell BAL (FIG. 7). By dividing those values by the estimated number of hepatocytes in the BAL, as determined by total protein analysis, specific albumin synthesis rates of 0.2 pg/cell/hr and 0.1 pg/cell/hr, respectively, were obtained. Ureagenesis Ureagenesis profiles were obtained for the extracapillary space and lumen outflow for both organoid-entrapped and dispersed-cell entrapped BAL's. A material balance taken around the hollow fiber bioreactor was performed to obtain a cumulative total rate of 2.57 mg/day for the organoid-entrapped BAL and 1.16 mg/day for the dispersed-cell BAL (FIG. 8). By dividing the values by the estimated number of hepatocytes in the BAL, as determined by total protein analysis, specific ureagenesis rates of 1.8 pg/cell/hr and 0.8 pg/cell/hr, respectively, were obtained. 4-MU metabolism The ability of collagen-entrapped hepatocyte organoids in a BAL device to conjugate was examined by assessing 4-MU metabolism. Every three days, medium on the extracapillary circuit was drained and replenished with fresh LTE medium containing 35 μM 4-MU. Daily sampling indicated that concentrations of 4-MU decreased from 35 μM to below 1 μM within 24 hr. The glucuronidated metabolite, 4-MUG, appeared in the culture medium. High glucuronidation activity was maintained in culture for over 10 days. The sulfated 4-MU metabolite (4-MUS) could not be detected at an assay sensitivity of 1μM. The activity represents the capability of pig hepatocyte organoids to carry out phase II metabolism for long time periods in a BAL device. EXAMPLE VII Collagen-entrapped Rat Organoid BAL A polysulfone hollow fiber cartridge (H1P3-100, Amicon, Danvers, Mass.) with a nominal molecular weight cut-off (MWCO) of 100 kiloDaltons (kD), an inner diameter of 1.1 mm and a total luminal volume of 10 ml was used as the BAL. The hollow fiber cartridge was autoclaved while immersed in distilled water for 30 minutes at 121° C. Other parts of the cultureware, including the oxygenator, media reservoir pH probe and dissolved oxygen probe were sterilized separately. The entire setup was assembled aseptically. The bioreactor was set up in a hollow fiber cell culture incubator, Acusyst Junior (Cellex Biosciences Inc., Coon Rapids, Minn.), which was microprocessor controlled to maintain pH and dissolved oxygen by gas blending. Freshly isolated primary rat hepatocytes were plated onto 60×15 mm Falcon Primaria culture dishes (Becton Dickinson Laboratories, Oxnard, Calif.) at a density of 5.3 or 7.4×104 cells/cm2 and incubated in 5 ml organoid medium. After 4 days, organoids and unaggregated hepatocytes were removed from the dishes by gentle pipetting. The mixture of organoids with unaggregated cells was centrifuged gently (34 g, 2 min), the supernatant was aspirated and the pellet was resuspended in a pre-mixed collagen solution. The solution was prepared by mixing at 4° C. 15 ml Vitrogen, a type I collagen, and 5 ml four-fold concentrated Williams' E medium. The pH of the mixture was adjusted to 7.4 by dropwise addition of sterile 1N sodium hydroxide. The collagen-cell mixture was inoculated into the luminal space of the hollow fiber cartridge. Approximately 500 ml prewarmed organoid media was recirculated at 200 ml/min on the extracapillary side to induce gelation of the collagen matrix. After gelation, or in approximately 30 minutes, the extracapillary medium recirculation rate was reduced to 35 ml/min. Within the first hour, the extracapillary medium was spiked with 12 μg/ml lidocaine by injecting lidocaine HCl (Abbott Laboratories, North Chicago, Ill.) into the extracapillary media reservoir. Lumen perfusion with organoid medium was initiated after 24 hours at 9 ml/hr. Medium from the intraluminal outflow was discarded after one pass. After 48 hours, medium on the extracapillary circuit was drained and replenished with fresh organoid medium containing 12 μg/ml lidocaine. Samples were drawn from sterile septa on the extracapillary circuit and lumen outlets and stored at -20° C. until measurement of albumin, lidocaine and its metabolites. Two different cell concentrations were used in the inoculation of the bioreactor. For the low inoculation cell concentration, hepatocyte organoids were prepared from 54 Primaria culture dishes, each seeded with 1.5×106 cells suspended in 5.0 ml of organoid medium. For the high inoculation cell concentration, 152 Primaria dishes each were seeded with 2.1×106 cells. Medium was replaced after 2 days of culture. Organoids and unaggregated hepatocytes were removed from the dishes on day 4 by repeated gentle pipetting and suspended into enriched medium. The mixture of organoids and unaggregated hepatocytes was pelleted and resuspended in a collagen solution before inoculation into the bioreactor. The contents of one dish from each experiment were separated by gravity into a organoid fraction and a dispersed-cell fraction. Based on the total protein content of each fraction, 35% and 45% of the originally plated cells formed organoids for the low and high inoculation experiment, respectively. Liver-specific functions higher in organoid-entrapped BAL than dispersed-cell BAL Oxygen uptake, albumin synthesis and lidocaine metabolism were used to evaluate organoid-entrapped BAL function. At the end of cultivation, fluorescence staining using fluorescein diacetate and ethidium bromide (Nikolai et al. "Improved Microscopic Observation of Mammalian Cells on Microcarriers by Fluorescent Staining" Cytotechnology (1991) 5:141-146) indicated good viability for hepatocytes in organoids. Most organoids were observed to maintain spherical morphology without disintegrating into single cells. Oxygen uptake A decrease in partial pressure of dissolved oxygen between the inlet and outlet of the bioreactor on the extracapillary space was observed, indicating oxygen consumption by the entrapped organoids and cells. The difference in partial pressure, multiplied by the solubility of oxygen in media at 37° C. (1.29×10-9 mol O2 /ml/mm Hg) and by the extracapillary medium flow rate, yielded an average oxygen consumption rate of 24.5 μmoles O2 /h and 40.0 μmoles O2 /h for the low and high cell concentration bioreactors, respectively. Both reactors yielded similar specific oxygen uptake rates (OUR) of 0.6±0.3 pmoles O2 /cell/h, after dividing the rates by the number of cells inoculated into each bioreactor, as determined by total protein analysis. Albumin synthesis Albumin synthesis profiles were obtained for the extracapillary space and lumen outflow for both studies. A material balance taken around the hollow fiber bioreactor was performed to obtain a cumulative total albumin synthesis rate of 13.0 μg/h and 80.6 μg/h for the low and high inoculation bioreactors, respectively. By dividing the values by the estimated number of hepatocytes in the BAL, as determined by total protein analysis, an average specific albumin synthesis rate of 0.54±0.04 pg/cell/h was obtained. Lidocaine Metabolism Within the first hour after loading on the first day, the extracapillary medium of both bioreactors was spiked with 12 μg/ml lidocaine. On the third day, the o extracapillary medium was drained and replenished with fresh aggregate media containing 12 μg/ml lidocaine. Both lidocaine and MEGX were measured for the two reactors on day 1 and day 3 of culture. In the bioreactor system the lidocaine added to the culture was adsorbed quickly onto the cultureware (bioreactor, tubing, oxygenator, medium reservoir). Thus lidocaine clearance was not a valid indication of metabolism. Instead the appearance of MEGX was used as an indicator of P-450 function. The specific production rate of MEGX was 0.11±0.04 pg/cell/h (Table 1). Previously, using a bioreactor entrapped with single cells, a comparable specific MEGX production rate of 0.08±0.04 pg/cell/h was reported (Shatford et al. "Hepatocyte Function in a Hollow Fiber Bioreactor: A Potential Bioartificial Liver J. Surg. Res. (1992) 53:549-557). Table 1 summarizes the metabolic activities of the BAL containing entrapped organoids versus with single-cell hepatocytes. The specific albumin synthesis rate for the organoid entrapped BAL was observed to be higher as compared to the single cell-entrapped BAL. The P-450 activity in the organoid-entrapped BAL also was higher, although to a lesser extent. The results indicate that enhanced specific, or per cell, liver functions for hepatocytes cultivated as organoids are maintained on collagen-entrapment. When entrapped in collagen gel for two days, organoids were observed to retain overall morphology. Ultrastructural evaluation suggests that organoids possess the ability to detect the presence of extracellular matrix proteins, as indicated by the presence of microvilli on the outermost surface of the organoid. Supplementing the entrapment matrix with Matrigel, laminin being the major constituent, led to improved maintenance of albumin synthesis as compared to collagen-entrapped organoids. TABLE 1 ______________________________________ SUMMARY OF COMPARISON OF DISPERSED-CELL-ENTRAPPED AND ORGANOID-ENTRAPPED BAL FUNCTION CRITERION SINGLE-CELL-BAL ORGANOID-BAL ______________________________________ Oxygen uptake rate 0.4 ± 0.3 0.6 ± 0.3 (pmoles O.sub.2 /cell/hour) Albumin synthesis 0.12 ± 0.01 0.54 ± 0.04 rate (pg/cell/hour) MEGX production 0.08 ± 0.04* 0.11 ± 0.04 rate (pg/cell/hour) 0.05 ± 0.04 ______________________________________ *based on previously reported data (Shatford et al. (1992) supra) All references cited herein are incorporated by reference in entirety. It will be evident that various modifications and changes can be made to the teachings set forth herein without departing from the spirit and scope of the instant invention. We claim: 1. A filter device comprising:a housing having first inlet and outlet ports defining a fluid flow cavity therebetween for flowing through said housing blood, serum or plasma; said cavity also enclosing a plurality of hollow fibers having porous walls and a partially occluded lumen; said porous walls comprising pores smaller than a hepatocyte; said lumen of said hollow fibers are in fluid flow communication with second inlet and outlet ports in said housing for flowing through said lumen a medium to support hepatocyte function and viability; and said lumen of said hollow fibers are partially occluded with an aqueous matrix comprising viable hepatocytes, wherein said hepatocytes are a mixture of unaggregated cells and aggregated cell masses; such that communication between said cavity and inside said hollow fibers is exclusively though the porous fiber walls. 2. The device of claim 1, wherein said hollow fibers have an inside diameter of 100-1000 μm. 3. The device of claim 2, wherein said inside diameter is 150-400 μm. 4. The device of claim 3, wherein said inside diameter is 200-250 μm. 5. The device of claim 1, wherein said pores allow passage of molecules with a molecular weight of up to 100,000. 6. The device of claim 1, wherein said medium is a serum-free medium. 7. The device of claim 1, wherein said matrix is selected from the group consisting of collagen, alginate, chitosan and fibrin. 8. The device of claim 7, wherein said matrix is collagen. 9. The device of claim 1, wherein said cell masses are 30-300 μm in diameter. 10. The device of claim 9, wherein said cell masses are 35-150 μm in diameter. 11. The device of claim 10, wherein the cell masses are 40-70 μm in diameter. 12. The device of claim 1, wherein said aqueous matrix is introduced into said fiber as a liquid and allowed to gel in situ, wherein said matrix gel contracts in the presence of said viable hepatocytes. 13. The device of claim 12, wherein said liquid contains hepatocytes at a concentration of 5-40×106 cells per milliliter. 14. The device of claim 13, wherein said concentration is 20-40×106 cells per milliliter. 15. The device of claim 14, wherein said concentration is 30-35×106 cells per milliliter. 16. The device of claim 13 wherein a half of the cells are in cell masses. 17. The device of claim 13 wherein two-thirds of the cells are in cell masses. 18. The device of claim 1, wherein said lumen is occluded 25-90% by said matrix. 19. The device of claim 18, wherein said lumen is occluded 33-75%. 20. The device of claim 1, wherein said hepatocytes are porcine hepatocytes.

1995-03-31

en

1997-01-21

US-19591662-A

Saturable core pulse width control apparatus March 1, 1966 J, SIKORRA 3,238,445 SATURABLE CORE PULSE WIDTH CONTROL APPARATUS Filed May 18, 1962 A FIG. I INPUT SIGNAL FIG. 2 2-2 i I I V f f g T3 INVENTOR. DANIEL J. SIKORRA ATTORN EY. United States Patent 3,238,445 SATURABLE CORE PULSE WIDTH CONTROL APPARATUS Daniel J. Sikorra, Champlin, Minn., assignor to Honeywell Inc., a corporation of Delaware Filed May 18, 1962, Ser. No. 195,916 7 Claims. (Cl. 323-75) This invention pertains to control circuits and more particularly to a motor control circuit for driving two terminal loads such as a permanent magnet DC motor. In a broad sense, the present invention comprises a bridge circuit having a transistor, or other current control means, in each leg thereof. A load device, such as a permanent magnet DC. motor, is connected across one diagonal of the bridge While a source of energizing potential is connected across the other diagonal of the bridge. A saturable transformer is connected in circuit with the bridge circuit so that the primary of the saturable transformer is energized by the conduction of the bridge transistors through the load device, and the secondary windings of the saturable transformer control the conduction and non-conduction of the bridge transistors. A source of input signals is connected in circuit with the primary windings of the saturable transformer to vary the conduction and non-conduction time of the bridge transistors. In normal circuit operation the transistors in first diagonally opposite legs of the bridge will conduct and hence a current will flow in a first direction through the load. The load voltage is then applied across the primary of the saturable transformer and after a predetermined time, determined by the volt-time characteristic of the transformer primary, the transformer will reach saturation. During the time that the transformer is saturating signals are induced in the transformer secondaries which hold the transistors in the first diagonally opposite legs of the bridge conducting and which hold the transistors in second diagonally opposite legs of the bridge non-conducting. When the transformer saturates, the field in the core collapses and signals are induced in the transformer secondaries such that the transistors in the first diagonally opposite legs of the bridge are cut off while the transistors in the second diagonally opposite legs of the bridge are turned on. When the transistors in the second diagonally opposite legs of the bridge conduct, a current will flow through the load device in a direction opposite to the current flow through the load when the transistor in the first diagonally opposite legs conduct. With no signal present from the input signal source the conduction time of the transistors in the first diagonally opposite leg of the bridge will be equal to the conduction time of transistors in the second diagonally opposite legs of the bridge. The bridge transistors are substantially low impedance devices and hence when the transistors conduct, substantially the entire source of energizing potential is dropped across or applied to the load, the polarity of the load voltage reversing each time the transistors in the diagonally opposite legs of the bridge change conduction states. When the conduction times of the transistors in the diagonally opposite legs of the bridge are equal, the time average load voltage will be zero. In the case where the load device is a permanent magnet motor, the load impedance to alternating current is high and hence the AC. current through the load is small. An input signal applied from the input signal source either aids or opposes the signal tending to saturate the saturable transformer and hence either decreases or increases respectively the conduction time of the transistors in diagonally opposite legs of the bridge. Since the conduction time of the bridge transistors is no longer equal, a resulting DC. current will flow through the load and, in the case of a DC. permanent magnet motor, the motor will produce a torque in one direction or the other depending upon the polarity of the input signal. In a copending Sikorra application, Serial No. 113,885, filed May 31, 1961, now Patent No. 3,199,011, there is shown another motor control circuit. The invention of my copending application is applicable to various circuits. It is especially well adapted for control of those terminal loads such as a split field motor. The teaching is also applicable to two-terminal loads but the efficiency in such arrangements is relatively low. In the present invention, on the other hand, the efiiciency of operation of two terminal loads is very high. It is one object of this invention, therefore, to provide an improved control circuit. Another object of this invention is to provide a control circuit particularly suited to the control of two terminal loads. These and other objects of my invention will become apparent to those skilled in the art upon consideration of the accompanying specification, claims and drawing of which: FIGURE 1 is a schematic diagram of an embodiment of this invention. FIGURE 2A illustrates the output of the circuit of FIGURE 1 in the absence of a control signal. FIGURE 2B illustrates the output of the circuit of FIGURE 1 when a control signal is applied. FIGURE 3 illustrates the effect of the control signal on the volt-time characteristic of the saturable transformer primary. Structure of FIGURE 1 Referring to FIGURE 1, there is shown a saturable transformer 20 having a primary winding 21 having end terminals 22 and 23, a primary winding 24 having end terminals 25 and 26, a secondary winding 27 having end terminals 30 and 31, a secondary winding 32 having end terminals 33 and 34, a secondary winding 35 having end terminals 36 and 37, and a secondary Winding 40 having end terminals 41 and 42. End terminal 22 of primary winding 21 is directly connected to end terminal 30 of secondary winding 27. End terminal 23 of winding 21 is connected by means of a capacitor 43 to end terminal 25 of primary winding 24. End terminal 26 of primary winding 24 is directly connected to end terminal 42 of secondary winding 40. End terminal 30 of secondary Winding 27 is directly connected to an emitter 45 of a transistor 44. Transistor 44 further has a base 46 and a collector 47. Base 46 of transistor 44 is connected by means of a resistor 50 to end terminal 31 of secondary winding 27. Collector 47 of transistor 44 is connected to ground 51. Emitter 45 of transistor 44 is directly connected to a collector of a transistor 52. Transistor 52 further has an emitter 53 and a base 54. Base 54 of transistor 52 is connected by means of a resistor 56 to end terminal 33 of secondary winding 32. End terminal 34 of secondary winding 32 is directly connected to emitter 53 of transistor 52. Emitter 53 of transistor 52 is directly connected to a source of energizing potential 57. Potential source 57 is connected to an emitter 61 of a transistor 60. Transistor further has a base 62 and an emitter 63. Base 62 of transistor 60 is connected by means of resistor 64 to the end terminal 37 of secondary winding 35. End terminal 36 of secondary winding 35 is directly connected to emitter 61 of transistor 60. Collector 63 of transistor 60 is directly connected to an emitter 66 of a transistor 65. Transistor 65 further has a base 67 and a collector 68. Base 67 of transistor 65 is connected by means of a resistor 70 to end terminal 41 of secondary winding 41). End terminal 42 of secondary winding 40 is connected to emitter 66 of transistor 65. Collector 68 of transistor 65 is connected directly to ground 51. Emitter 66 of transistor 65 is connected to a terminal 72 of a load 71, in this case a DC. permanent magnet motor. Load 71 further has a terminal 73. Terminal 73 of load 71 is directly connected to emitter 45 of transistor 44. A source of input signals 75 has a first output terminal 76 and a second output terminal 77. Output terminal 76 of source 75 is directly connected to end terminal 23 of transformer primary winding 21, While output terminal 77 of input signal source 75 is directly connected to end terminal 25 of transformer primary winding 24. Operation FIGURE 1 In considering the operation of the circuit of FIGURE I assume that the output signal from input signal source 75 is zero and that transistors 52 and 65 are just beginning to conduct. When transistors 52 and 65 conduct a current will flow from the potential source 57 through emitter 53 to collector 55 of transistor 52, load 71, and emitter 66 to collector 68 of transistor 65 to ground 51. Since transistors 52 and 65 are relatively low impedances when conducting, substantially the entire potential source 57 is dropped across load 71 such that terminal 73 is positive with respect to terminal 72. The volt drop across load 71 is coupled across the primary windings 21 and 24 of saturable transformer such that end terminal 22 of primary winding 21 is positive with respect to end terminal 26 of primary winding 24. The volt drop across primary windings 21 and 24 of saturable transformer 20 induces a voltage into the secondary windings 27, 32, 35 and 40 of transformer 20. The voltage induced in secondary winding 27 is of a polarity such that end terminal 31 is positive with respect to end terminal 30. The positive voltage at end terminal 31 of secondary 27 is coupled through resistor 50 to the base 46 of transistor 44 thereby holding transistor 44 in an off or non-conducting state. The voltage induced in secondary winding 35 is of a polarity such that end terminal 37 is positive with respect to end terminal 36. The voltage at end terminal 37 is coupled through resistor 64 to the base 62 of transistor 60 thereby holding transistor 60 in an off or non-conducting state. The voltage induced in secondary winding 32 is such that end terminal 33 is negative with respect to end terminal 34. This negative potential at end terminal 33 of winding 32 is coupled through resistor 56 to the base 54 of transistor 52 thereby holding transistor 52 in its on or conducting state. Similarly, the voltage induced in secondary winding 411) is of a polarity such that end terminal 41 is negative with respect to end terminal 42. The negative voltage at end terminal 41 is coupled through resistor 70 to the base 67 of transistor 65 thereby holding transistor 65 in its on or conducting state. The conduction of transistors 52 and 65 continues until the voltage produced across the primary windings 21 and 24 of saturable transformer 20 drive the transformer core to saturation. When the transformer saturates, the voltage induced in the transformer secondary windings 27, 32, 35 and 40 will disappear and a back E.M.F. will be generated by the collapsing fields around the secondary windings. The collapsing magnetic fields around the secondary windings induce opposite polarity signals in the secondary windings. The signal induced in secondary winding 27 will be of a polarity such that terminal 31 is negative with respect to end terminal 39. The negative signal at end terminal 31 is coupled through resistor 50 to base 46 of transistor 44 thereby switching transistor 44 to its on or conduct ing state. Similarly, the signal induced in secondary winding 35 is of a polarity such that end terminal 37 is negative with respect to end terminal 36. The negative potential at end terminal 37 is coupled through resistor 64 to the base 62 of transistor 60 thereby switching transistor 60 to its on or conducting state. At the same time, a signal is induced in secondary winding 32 such that end terminal 33 is positive with respect to end terminal 34. The positive potential at end! terminal 33 is coupled through resistor 56 to base 54 of transistor 52 thereby switching transistor 52 to its off or non-conducting state. Similarly, the potential induced in secondary winding 40 is such that end terminal 411s positive with respect to end terminal 42. The positive potential at end terminal 41 is coupled through resistor to the base 67 of transistor 65 thereby switchlng transistor 65 to its off or non-conducting state. Since transistors 44 and 60 are now conducting, a current will flow from the potential source 57 through eml ter 61 to collector 63 of transistor 60, load 71, and emitter 45 to collector 47 of transistor 44 to ground 51. Since, as explained previously, transistors 44 and 60 are relatively low impedance devices when conducting, substantially all of potential source 57 is dropped across load device 71. The potential drop across load 71 is such t at terminal 72 is positive with respect to terminal 73. The volt drop across load 71 is coupled across primary Windings 21 and 24 of saturable transformer 20 such that end terminal 26 of primary winding 24 is positive with respect to end terminal 22 of primary winding 21. As explained hereinbefore, the volt drop across primary windings 21 and 24 induce voltages in secondary windings 27, 32, 35 and 40. The voltages induced in sec ondary windings 32 and 40 will be of a polarity such as to hold transistors 52 and 65 respectively in their oil or non-conducting state. p The voltages induced in secondary windings 27 and 35 are of a polarity such as to hold transistors 44 and 60 in their on or conducting states. As in the case of the conduction of transistors 52 and 65, transistors 44 and 60 will continue to conduct until saturable transformer 20 is driven to saturation in the opposite direction, at which time the voltages induced in the transformer secondaries will disappear and a back will be generated which will again turn tran= sistors 52 and 65 on and transistors 44 and 60 off. FIGURE 2A shows an idealized wave form of the load voltage measured across load 71. Referring to FIGURE 2A it can be seen that the positive and negative half cycles of the rectangular wave load voltage have equal periods and equal but opposite magnitudes so that the time average of the load voltage will be zero. Assume now that a DO. input signal appears at the output of input signal source 75 such that terminal 76 is positive with respect to terminal 77. When transistors 52 and 65 conduct, source 57 is effectively connected across primary windings 21 and 24 such that the positive terminal 57 is connected to terminal 22 of primary winding 21 and the negative terminal, or ground, 51 is connected to the end terminal 26 of primary winding 24. Thus, source 57 acts as an energizing source for primary windings 21 and 24. It can readily be seen that the input signal is of a polarity such that it opposes potential source 57. Since the volt-time product of saturable transformer 20 is a constant, when the energizing voltage increases the time required to saturate the core must decrease. Since, as explained above, the control signal opposes potential source 57, the time required to saturate the core when. transistors 52 and 65 conduct, increases. Assume that the input signal remains at the. same p0- larity, that is, terminal 76 positive with respect to terminal 7. When transistors 44 and 60 conduct, source 57 will now be effectively connected across primary windings 21 and 24 such that end terminal 26 of primary winding 24 is positive with respect to end terminal 22 of primary winding 21. It can now be seen that the input signals aids energizing source 57 and hence the energizing voltage will increase. Since, as explained above, the volttime product must remain a constant, and since the energizing voltage has increased, the time now required to saturate the core must decrease. The effect of the input signal upon circuit operation can be seen by referring to FIGURE 3. FIGURE 3 shows a plot of the constant volt-time product for saturable transformer 20. When the input signal is zero, the voltage applied to primary windings 21 and 24 will be approximately equal to source voltage 57. This voltage is represented by E in FIGURE 3. When E is applied to the transformer cores 21 and 24, the conduction time of the positive and negative conduction periods Will be equal to 1 However, when a control signal is applied to the transformer primaries as explained above, this input signal will subtract from the source in one case, when transistors '52 and 65 conduct, and will add to the potential source when transistors 44 and 60 conduct. This can be seen in FIGURE 3 wherein voltage E represent voltage applied to the transformer primaries when transistors 44 and 60 conduct and E represents the voltage applied to the primaries when transistors 52 and 65 conduct. From FIG- URE 3 it can be seen that when E is applied to the transformer primaries the time required to drive the core to saturation, that is t has decreased, while when B is applied to the transformer primaries, the time required to drive the core into saturation, that is t has increased. The load waveform, when an input signal is applied to the circuit, is shown in FIGURE 28. FIGURE 2B shows that the conduction time of the negative conduction period has increased while the conduction time of the positive conduction period has decreased, the magnitude of positive and negative conduction periods still being equal. If the input signal from signal source 75 is of the opposite polarity, that is, terminal 77 positive with respect to terminal 76, the input signal will aid potential source 57 when the transistors 52 and 65 conduct, and will oppose source 57 when transistors 44 and 60 conduct. In this case the load waveform across load device 71 is similar to that shown in FIGURE 2B except that the conduction time of the positive conduction period is longer than the conduction time of the negative conduction period. It is to be understood that While I have shown a specific embodiment of my invention, that this is for the purpose of illustration only and that my invention is to be limited solely by the scope of the appended claims. What I claim is: 1. Apparatus of the class described comprising: first, second, third and fourth current control means; means connecting said first and third current control means in series; means connecting said second and fourth current control means in series across said first and third current control means so as to form a bridge circuit; means for connecting a load across one diagonal of said bridge circuit; means for connecting a source of energizing potential across the other diagonal of said bridge circuit; a saturable transformer having primary windings and first, second, third and fourth secondary windings; means connecting the primary windings of said saturable transformer across said load means; means connecting the first, second, third and fourth secondary windings of said saturable transformer in controlling relation to said first, second, third and fourth current control means respectively; and means for connecting a source of input signals in circuit with the primary windings of said saturable transformer. 2. Apparatus of the class described comprising: first, second, third, and fourth transistors each having a collector electrode, a base electrode, and an emitter electrode; means connecting said first and third transistors in series; means connecting said second and fourth transistors in series across said first and third transistors so as to form a bridge circuit; load means connected across one diagonal of said bridge circuit; a source of energizing potential connected across the other diagonal of said bridge circuit; a saturable transformer having primary windings and first, second, third, and fourth secondary windings; means connecting the primary windings of said saturable transformer across said load means; means connecting the first, second, third, and fourth secondary windings of said saturable transformer from the base to emitter electrodes of said first, secend, third, and fourth transistors respectively; - and a source of input signals connected in circuit with the primary windings of said saturable transformer. 3. Apparatus of the class described comprising: a transistorized bridge circuit, said bridge circuit having a transistor in each leg thereof; load means connected across one diagonal of said bridge circuit; a source of energizing potential connected across the other diagonal of said bridge circuit; a saturable transformer having primary and secondary windings wound in inductive relation thereto; means connecting the primary windings of said saturable transformer across said load means; means connecting the secondary windings of said saturable transformer in controlling relation to said bridge circuit, whereby signals induced in said secondary windings produce conduction in transistors in first diagonally opposite legs of the bridge circuit and non-conduction in transistors in second diagonally opposite legs of the bridge circuit; and a source of input signals connected in circuit with the primary windings of said saturable transformer to vary the conduction and non-conduction times of of the transistors in the first and second diagonally opposite legs of the bridge circuit. 4. Apparatus of the class described comprising: transistorized bridge circuit, said bridge circuit having a transistor in each leg thereof; a source of energizing potential connected across one diagonal of said bridge circuit; load means connected across the other diagonal of said bridge circuit; a saturable transformer having primary and secondary windings wound in inductive relation thereto; means connecting the primary windings of said saturable transformer across said load means; means connecting the secondary windings of said saturable transformer to said transistorized bridge circuit whereby transistors in a first diagonally opposite legs of said bridge will conduct during a first time period and transistors in second diagonally opposite legs of said bridge will conduct during a second time period; and a source of input signals connected in circuit with the primary windings of said saturable transformer to vary the duration of said first and second time periods. 5. Apparatus of the class described comprising: a transistorized bridge circuit, said bridge circuit having a transistor in each leg thereof; means for connecting a source of energizing potential across one diagonal of said bridge circuit; means for connecting load means across the other diagonal of said bridge circuit; a saturable transformer having primary and secondary windings wound in inductive relation thereto; means connecting the primary windings of said saturable transformer across said load means; means connecting the secondary windings of said saturable transformer to said transistorized bridge circuit whereby transistors in first diagonally opposite legs of said bridge will conduct during a first time period and transistors in second diagonally opposite legs of said bridge will conduct during a second time period; and means for connecting a source of input signals in circuit with the primary windings of said saturable transformer to vary the duration of said first and second time periods. 6. Apparatus of the class described comprising: first, second, third, and fourth current control means each having a collector electrode, a base electrode, and an emitter electrode; means connecting said first and third current control means in series; means connecting said second and fourth current control means in series across said first and third current control means so as to form a bridge circuit; load means connected across one diagonal of said bridge circuit; a source of energizing potential connected across the other diagonal of said bridge circuit; a saturable transformer having primary windings and first, second, third, and fourth secondary windings; means connecting the primary windings of said saturable transformer across said load means; means connecting the first, second, third, and fourth secondary windings of said saturable transformer in controlling relation to said first, second, third, and fourth current control means respectively; and means for connecting a source of input signals in circuit with the primary windings of said saturable transformer. across the other diagonal of said bridge circuit; means connecting the primary windings of said satur- 7. Apparatus of the class described comprising: a transistorized bridge circuit, said bridge circuit having a transistor in each leg thereof; means for connecting a load means across one diagonal of said bridge circuit; means for connecting a source of energizing potential across the other diagonal of said bridge circuit; a saturable transformer having primary and secondary windings wound in inductive relation thereto; means connecting the primary windings of said saturable transformer across said load means; means connecting the secondary windings of said saturable transformer in controlling relation to said bridge circuit, whereby signals induced in said secondary windings produce conduction in transistors in first diagonally opposite legs of the bridge circuit and non-conduction in transistors in second diagonally opposite legs of the bridge circuit; and means for connecting source of input signals in circuit with the primary windings of said saturable transformer to vary the conduction and non-conduction times of the transistors in the first and second diagonally opposite legs of the bridge circuit. References Cited by the Examiner UNITED STATES PATENTS 2,821,639 1/1958 Bright et a1 323-75 X 2,897,296 7/1959 Buchhold 32375 X 2,931,991 4/1960 Schultz 32l2 X 3,034,072 5/1962 Hakimoglu 331113.l 3,067,378 12/1962 Paynter 321 X 3,080,534 3/1963 Paynter 3212 X LLOYD MCCOLLUM, Primary Examiner. A. D. PELLINEN, Assistant Examiner. 1. APPARATUS OF THE CLASS DESCRIBED COMPRISING: FIRST, SECOND, THIRD AND FOURTH CURRENT CONTROL MEANS; MEANS CONNECTING SAID FIRST AND THIRD CURRENT CONTROL MEANS IN SERIES; MEANS CONNECTING SAID SECOND AND FOURTH CURRENT CONTROL MEANS IN SERIES ACROSS SAID FIRST AND THIRD CURRENT CONTROL MEANS SO AS TO FORM A BRIDGE CIRCUIT; MEANS FOR CONNECTING A LOAD ACROSS ONE DIAGONAL OF SAID BRIDGE CIRCUIT; MEANS FOR CONNECTING A SOURCE OF ENERGIZING POTENTIAL ACROSS THE OTHER DIAGONAL OF SAID BRIDGE CIRCUIT; A SATURABLE TRANSFORMER HAVING PRIMARY WINDINGS AND FIRST, SECOND, THIRD AND FOURTH SECONDARY WINDINGS; MEANS CONNECTING THE PRIMARY WINDINGS OF SAID SATURABLE TRANSFORMER ACROSS SAID LOAD MEANS; MEANS CONNECTING THE FIRST, SECOND, THIRD AND FOURTH SECONDARY WINDINGS OF SAID SATURABLE TRANSFORMER IN CONTROLLING RELATION OF SAID FIRST, SECOND, THIRD AND FOURTH CURRENT CONTROL MEANS RESPECTIVELY; AND MEANS FOR CONNECTING A SOURCE OF INPUT SIGNALS IN CIRCUIT WITH THE PRIMARY WINDINGS OF SAID SATURABLE TRANSFORMER.

1962-05-18

en

1966-03-01

US-28963894-A

Type of polymer latex and its use as plasticizer in a photographic material ABSTRACT New types of polymer latices and their use in photographic materials are disclosed. They are obtained by subjecting to radical emulsion polymerisation one or more radical-polymerisable monomers, whose emulsifier-free homopolymers or copolymers possess a glass transition temperature below 65° C., preferably below 30° C., in the presence of a water-soluble polymer of a particular chemical formula. These new types of latices are preferably used in graphic arts contact materials, e.g. daylight materials. They can be used in relative high amounts thus improving dimensional stability without deteriorating the scratch resistance too strongly. A preferred radical-polymerisable monomer mixture comprises n.-butyl acrylate, methyl methacrylate and acrylic acid. DESCRIPTION 1. Field of the Invention The present invention relates to new types of polymeric latices and their use in photographic materials. 2. Background of the Invention Coated photographic layers and complete photographic materials must comply with a number of requirements concerning physical properties. In order to avoid physical damage during manufacturing and handling a photographic material must show a sufficiently high scratch resistance. Furtheron, photographic materials must show a good flexibility so that easy handling without the occurence of creases or cracks is possible; in other words, the materials may not suffer from brittleness especially under critical low humidity conditions. On the other hand, stickiness should be avoided. Still furtheron, photographic materials must show a good dimensional stability, meaning a minimal dimensional distortion during processing especially during the drying phase at elevated temperature. The requirement of dimensional stability is particularly stringent for graphic arts contact materials often serving in pre-press activity as final intermediates between colour separations produced on a scanner and the exposure step onto a printing plate. Several contacts, being duplicates of different separations, have to be exposed in register on one and the same printing plate and mutually different dimensional distortions would lead to unacceptable colour shifts on image edges in the final print. As well known in the art flexibility and dimensional stability can be improved by the incorporation of so-called plasticizers. These substances can be relatively low-molecular weight compounds, preferably containing several hydrophilic groups like hydroxyl groups, or they can be polymer latices preferably having a rather low glass transition temperature. The former act in an indirect way by retaining enough water in the gelatinous layer even at low relative humidity. In this way the layer is kept sufficiently flexible at room temperature, even at a high hardening degree of the gelatinous layer while the required dimensional stability is assured. Representative plasticizers include alcohols, dihydric alcohols, trihydric alcohols and polyhydric alcohols, acid amides, cellulose derivatives, lipophilic couplers, esters, phosphate esters such as tricresyl phosphate, glycol esters, diethylene glycol mixed esters, phthalate esters such as dibutyl phthalate and butyl stearate, tetraethylene glycol dimethyl ether, ethyl acetate copolymers, lactams, lower alkyl esters of ethylene bis-glycolic acid, esters or diesters of an alkylene glycol or a polyalkylene glycol, polyacrylic acid esters, polyethylene imines, poly(vinyl acetate) and polyurethanes, as illustrated by Eastman et al U.S. Pat. No. 306,470, Wiest U.S. Pat. No. 3,635,853, Milton et al U.S. Pat. No. 2,960,505, Faber et al U.S. Pat. No. 3,412,159, Ishihara et al U.S. Pat. No. 3,640,721, Illingsworth et al U.S. Pat. No. 3, 0003, 878, Lowe et al U.S. Pat. No. 2,327,808, Urnberger U.S. Pat. No. 3,361,565, Gray U.S. Pat. No. 2,865,792, Milton U.S. Pat. Nos. 2,904,434 and 2,860,980, Milton et al U.S. Pat. No. 3,033,680, Dersch et al U.S. Pat. No. 3,173,790, Fowler U.S. Pat. No. 2,772,166 and Fowler et al U.S. Pat. No. 2,835,582, Van Paesschen et al U.S. Pat. No. 3,397,988, Balle et al U.S. Pat. No. 3,791,857, Jones et al U.S. Pat. No. 2,759,821, Ream et al U.S. Pat. No. 3,287,289 and De Winter et al U.S. Pat. No. 4,245,036. Low-molecular plasticizers with hydrophilic groups show the disadvantage of rendering the coated hydrophilic layer(s) of a photographic element sticky particularly at elevated relative humidity. When photographic materials are packaged, stored and delivered in a web-like or sheet-like manner an unacceptable adherance of support parts to surface parts can occur during storage or after processing. Moreover, they are not diffusion resistant. On the other hand, plasticizers consisting of conventional polymer latices, e.g. polyethylacrylates and analogues which are widely used in commercial materials, show other drawbacks. The amount of latex which can be incorporated in a gelatinous layer in order to improve dimensional stability is limited because high concentrations of the latex disturb the cohesion of the gelatine matrix resulting in a decrease of the scratch resistance eventually below a critical level. So there is a need for new types of latices which can be incorporated in gelatinous layers upto higher latex/gelatin ratios without affecting the scratch resistance too strongly. Attempts to provide latices giving improved physical properties are disclosed e.g. EP 0 477 670, which describes the use of gelatin-grafted latices, in WO/14968, which discloses reduced pressure fog with uncase-hardened and case-hardened gelatine-grafted polymer latices, and in EP 0 219 101 which discloses incorporation of high quantities of hydrophobic latices by surrounding them during preparation with natural water-soluble polymers like dextranes. U.S. Pat. No. 4,714,671 discloses polymer latices in which the dispersed particles consist of a soft hydrophobic core and a hard shell giving rise to suitable plasticizers which do not diffuse out of the layer under tropical conditions. The present invention extends the teachings on improved polymer latices for use as plasticizers in photographic materials. It is an object of the present invention to provide new types of latices which can be incorporated in gelatinous layers in high concentrations while retaining good scratch resistance. It is a further object of the present invention to provide improved photographic materials showing an excellent compromise between dimensional stability, flexibility and scratch resistance. Other objects of the invention will become apparent from the description hereafter. 3. Summary of the Invention The objects of the present invention are realized by providing a photographic material, comprising a support, at least one silver halide emulsion layer, and optionally one or more other hydrophilic layer(s), characterized in that at least one of said emulsion or other hydrophilic layer(s) contains a polymer latex with an average particle size of less than 500 μm, which is obtained by subjecting to radical emulsion polymerisation one or more radical-polymerisable monomers, whose emulsifier-free homopolymers or copolymers possess a glass transition temperature below 65° C., preferably below 30° C., in the presence of a water-soluble polymer of formula I ##STR1## wherein Z is --CH2 --CR1 R2 --(I.1) or ##STR2## M represents H, Na, K, Li, or NH4, R represents H or CH3, R2 represents H, C1 -C6 unsubstituted or sustituted alkyl (preferably --CH3, --C2 H5, --C4 H9, --CH2 C (CH3)3), unsubstituted or substituted aryl (preferably phenyl or tolyl), --(CH2)m--OCO--R5, wherein R5 corresponds to C1 -C8 alkyl and m is 0 or 1, ##STR3## A represents OM, OR3, NH2, NHR3, O--R4 --(SO3 M)n or NH--R4 --(SO3 M)n, wherein R3 represents C1 -C4 alkyl, R4 represents an aliphatic or aromatic residue of 1 to 10 C atoms, preferably a residue derived from a C1 -C4 alkane or from benzene, methylbenzene or naphthalene, n is 1 or 2, and x,y are chosen in such a way that the weight-average molecular weight of polymer I is comprised between 5,000 to 500,000, preferably between 10,000 and 200,000, and the ratio x:y is comprised between 1:4 and 1:1 preferably between 1:3 and 1:1. The described emulsion polymer latices are new themselves with the exception of those compounds (I.1) wherein A equals NH--R4 --(SO3 M)n. The preparation of these latter latices and their use in paper sizing agents is known from DE 3807097. It was found surprisingly that the incorporation of the invention latices in one or more hydrophilic layers of a photographic material drastically improved the scratch resistance/concentration relationship compared to conventional latices as polyethylacrylate and analogues. In this way it became possible to improve the dimensional stability of the photographic material sufficiently without decreasing the scratch resistance below an unacceptable level. 4. Detailed Description The polymers 1.1 are known (DE 3344470, DE 3807097, DE 3429961, DE 3609981, DE 3703551, DE 3331542, EP 0 307 778, EP 0 009 185, DE4034871, U.S. Pat. No. 4,151,336, J. Am. Chem. Soc. Vol. 68 (1946) p. 1495, J. Macromol. Sci.-Chem. Vol. A6(8) (1972) p. 1459, J. Macromol. Sci.-Chem. Vol. A4(1) (1970) p. 51). The polymers are formed in a reaction of alternatingly or statistically composed copolymers II of maleic acid anhydride and α-olefins ##STR4## with the acid anhydride ring of II splitting reagents III. Suitable α-olefins are those having 2 to 9 C atoms such as, e.g., ethylene, propylene, butene-1, isobutylene and α-methylstyrene. Especially preferred are α-diisobutylene, styrene and vinyl esters such as vinyl acetate or vinyl esters of branched-chain carboxylic acids (R Lican 261, -270, -279, -288 or -245 from Huels AG). The preparation of their copolymers with maleic anhydride is known in principle and described, e.g., in "Houben-Weyl, Methoden der organischen Chemie, Bd. E XIV, Teil 2, Georg Thieme Verlag, Stuttgart, 1987". The acid anhydride ring-splitting reagents III are III a) bases, preferably sodium hydroxide or potassium hydroxide, III b) short-chained alcohols or alcoholates having up to 4 C atoms, III c) ammonia or short-chained amines having up to 4 C atoms, III d) aminosulphonic acids of following formula: H.sub.2 N--R.sup.4 --(SO.sub.3 M).sub.n, wherein R4, M, and n have the significances given in formula I. Suitable examples include 2-aminoethanesulphonic acid, 2-, 3-, or 4-aminobenzenesulphonic acid, aminonaphthalenesulphonic acids, 4-amino-1,3-benzenedisulphonic acid, 5-amino-1,3-benzenedisulphonic acid and 2-amino-1,4-benzenedisulphonic acid or alkali salts of these sulphonic acids, or III e) propanesulton or butanesulton. The polymers I.2 can be prepared in a similar way from known copolymers of maleic acid anhydride and furan (See J. Am. Chem. Soc. Vol. 68 (1946) p. 1495, J. Macromol. Sci.-Chem. Vol. A6(8) (1972) p. 1459, J. Macromol. Sci.-Chem. Vol. A4(1) (1970) p. 51, both cited above) by the ring splitting reagents III. Suitable polymers I.1 are, e.g.: ##STR5## (mixture wherein the sum of R', R" and R'" represents --C7 H17) ##STR6## A suitable polymer I.2 is: ##STR7## Preference is given to the polymers Ia-5 and Ic-1. Especially preferred are the polymers Ia-1 and Id-1. The polymers I may also be mixtures wherein preferably more than 80% especially more than 90%, based on the mixture, are structural units I. Possible structural units that can be contained in the mixtures of I result, e.g., from the incomplete conversion of the maleic anhydride groups, ##STR8## conversion of an acid anhydride group by water, ##STR9## double conversion of an acid anhydride group in case of an excess of alcohol reagent, ##STR10## double conversion of an acid anhydride group with an amine or an aminoalkylsulphonic acid, under specific reaction conditions, with formation of an imide. ##STR11## or by adding a third monomer, so that modified polymers form which contain terpolymeric units; examples: ##STR12## The polymers (I) are used in the emulsion polymerisation according to the invention in an amount of 0.5 to 35, preferably of 2 to 10% by weight, based on the amount of monomers to be polymerised. They possess a.o. emulsifying properties and are being grafted at least partially by the radical-polymerising monomers. The monomers according to the invention to be radical-polymerised in the presence of the polymers I are e.g. (meth) acrylic acid esters, mixtures of (meth) acrylic acid esters or monomer mixtures that contain at least 50% by weight of (meth) acrylic acid esters, provided that the glass temperature of the emulsifier-free polymers of the used monomers or monomer mixtures are below 65° C. By the term (meth) acrylic acid esters within the scope of this invention are to be understood esters of methacrylic- and acrylic acid. Suitable (meth)acrylic acid esters are, e.g.: 2-Propenoic acid, methylester 2-Propenoic acid, pentyl ester 2-Propenoic acid, butyl ester 2-Propenoic acid, phenylmethyl ester 2-Propenoic acid, cyclohexyl ester 2-Propenoic acid, cyclopentyl ester 2-Propenoic acid, hexadecyl ester 2-Propenoic acid, 2-methylpropyl ester 2-Propenoic acid, 2-ethylhexyl ester 2-Propenoic acid, 2-(1-ethyl)pentyl ester 2-Propenoic acid, 2-(2-ethoxyethoxy)-ethyl ester 2-Propenoic acid, 2-butoxyethyl ester 2-Propenoic acid, 2-(2-methoxyethoxy)-ethyl ester 2-Propenoic acid, 2-n-propyl-3-i-propylpropyl ester 2-Propenoic acid, octyl ester 2-Propenoic acid, octadecyl ester 2-Propenoic acid, 2-ethoxyethyl ester 2-Propenoic acid, 2-methoxyethyl ester 2-Propenoic acid, 2-(methoxyethoxy)ethyl ester 2-Propenoic acid, ethyl ester 2-Propenoic acid, propyl ester 2-Propenoic acid, 2-phenoxyethyl ester 2-Propenoic acid, phenyl ester 2-Propenoic acid, 1-methylethyl ester 2-Propenoic acid, hexyl ester 2-Propenoic acid, 1-methylpropyl ester 2-Propenoic acid, 2,2-dimethylbutyl ester Especially suited (meth)acrylic acid esters are 2-propenoic acid methyl ester, 2-propenoic acid n-butyl ester and 2-propenoic acid ethyl ester. In a further preferred embodiment, in addition to the described (meth)acrylic acid esters, up to 50%, preferably 1 to 20%, of vinyl monomers are used that contain anionic groups or form such groups depending on the pH. Preference is given to vinyl monomers that contain carboxylate groups or sulphonate groups or that are capable of forming them by a variation of the pH. Examples of preferred vinyl monomers of this kind are 1-Propene-1,2,3-tricarboxylic acid 2-Propenoic acid 2-Propenoic acid, sodium salt 2-Chloro-2-propenoic acid 2-Propenoic acid, 2-carboxyethyl ester 2-Methyl-2-propenoic acid 2-Methyl-2-propenoic acid, lithium salt Methylenebutanedioic acid 2-Butenedioic acid 2-Methylbutenedioic acid 2-Methylenepentendioic acid 2-Carboethoxyallyl sulfate, sodium salt 2-Propenoic acid, ester with 4-hydroxy-1-butanesulphonic acid, sodium salt 2-Propenoic acid, ester with 4-hydroxy-2-butanesulphonic acid, sodium salt 3-Allyloxy-2-hydroxypropanesulphonic acid, sodium salt 2-Methyl-2-propenoic acid, ester with 3-[tert-butyl(2-hydroxyethyl)amino]propane sulphonic acid Ethenesulphonic acid, sodium salt Methylenesuccinic acid, diester with 3-hydroxy-1-propane sulphonic acid, disodium salt 2-Methyl-2-propenoic acid, ester with 2-(sulphooxy) ethyl, sodium salt N-3-Sulphopropyl acrylamide, potassium salt 2-Methyl-2-propenoic acid, 2-sulphoethyl ester 2-Methyl-2-propenoic acid, 2-sulphoethyl ester, lithium salt p-Styrene sulphonic acid, ammonium salt N-1,1-dimethyl-2-sulphoethyl acrylamide, sodium salt p-Styrene sulphonic acid, potassium salt p-Styrene sulphonic acid 4-4-Ethenylbenzenesulphonic acid, sodium salt, 2-Propenoic acid, 3-sulphopropyl ester, sodium salt m-Sulphomethylstyrene sulphonic acid, potassium salt p-Sulphomethylstyrene sulphonic acid, sodium salt 2-Methyl-2-propenoic acid, 3-sulphopropyl ester, sodium salt 2-Methyl-2-propenoic acid, 3-sulphobutyl ester, sodium salt 2-Methyl-2-propenoix acid, 4-sulphobutyl ester, sodium salt 2-Methyl-2-propenoic acid, 2-sulphoethyl ester, sodium salt 2-Methyl-2-[(1-oxo-2-propenyl)amino]-1-propane sulphonic acid 2-Methyl-2-[(1-oxo-2-propenyl)amino]-1-propane sulphonic acid, sodium salt 2-Methyl-2-[(1-oxo-2-propenyl)amino]-1-propane sulphonic acid, potassium salt Especially preferred vinyl monomers with anionic groups are 2-propenoic acid sodium salt and N-1,1-dimethyl-2-sulphoethyl acrylamide sodium salt. Moreover, mixtures according to the invention of radical-polymerisable monomers can contain such vinyl monomers up to 25% by weight, preferably 0.5 to 15% by weight, which are capable of reacting with gelatine or with gelatine hardeners that are of common use in photographic layers. Suitable vinyl monomers that are reactive with respect to gelatine or gelatine hardeners are 2-Chloroethylacrylate Acetoacetoxyethylacrylate 3-Chloromethylstyrene 4-Chloromethylstyrene 2-Cyano-N-2-propenylacetamide 2-Methyl-2-propenoic acid, 2-aminoethyl ester, hydrochloride 2-Propenoic acid, 2-aminoethyl ester N-Methacryloyl-N'-glycylhydrazine hydrochloride 5-Hexene-2,4-dione 5-Methyl-5-hexene-2,4-dione 2-Methyl-2-propenoic acid, 2-[(cyanoacetyl)-oxy]ethyl ester 2-Propenoic acid, oxidranylmethyl ester 2-Methyl-2-propenoic acid, oxidranylmethyl ester Acetoacetoxy-2,2-dimethylpropyl methacrylate 3-Oxo-4-pentenoic acid, ethyl ester N-(2-Aminoethy)-2-methyl-2-propenamide, monohydrochloride 3-oxo-butanoic acid, 2-[(2-methyl-1-oxo-2-propenyl)oxy]ethyl ester 2-Propenamido-4-(2-chloroethylsulphonylmethyl)benzene 3-(2-ethyl sulphonylmethyl)styrene 4-(2-ethylsulphonylmethyl)styrene N-(2-Amino-2-methylpropyl)-N'-ethenylbutanediamide Propenamide Acetoacetoxyethylmethacrylate Preferred vinyl monomers that are reactive with respect to gelatine or gelatine hardeners are acetoacetoxyethylmethacrylate and 4-chloromethylstyrene. The radical-polymerisable monomer mixtures according to the invention may contain further vinyl monomers that contribute to a further modification of the emulsion polymer, e.g. with respect to its glass transition temperature, its refractive indices or gel content, as long as the emulsifier-free polymers derived from those monomer mixtures possess a glass transition temperature below 65° C., preferably below 30° C. Preferred vinyl monomers of this kind are Allylmethacrylate Tetraallyloxyethane Acrylamide Styrene (1-Methylethenyl)benzene 3-Octadecyloxystyrene 4-Octadecyloxystyrene N-(3-Hydroxyphenyl)-2-methyl-2-propenamide 2-Propenoic acid, 2-hydroxyethyl ester 2-Propenoic acid, 2-hydroxypropyl ester N-(1-Methylethyl)-2-propenamide 3-Ethenylbenzoic acid 4-Ethenylbenzoic acid N-(2-Hydroxypropyl)-2-methyl-2-propenamide N,2-Dimethyl-2-propenamide 2-Methyl-2-propenamide N-(2-Hydroxypropyl)-2-methyl-2-propenamide N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]-2-propenamide N-(1,1-Dimethylethyl)-2-propenamide Acetic acid ethenyl ester 3-Methylstyrene 4-Methylstyrene N,N-dimethyl-2-propenamide Ethyleneglycoldimethacrylate Furan In a particularly preferred embodiment the radical-polymerisable monomers comprise a mixture of n.-butylacrylate (preferably higher then or equal to 41%), methylmethacrylate (preferably lower then or equal to 56%) and acrylic acid (preferably between 1 and 3%). As initiators are taken into account in general 0.05 to 5% by weight, based on the monomers, of initiators decomposing in radicals. Such initiators are, e.g., organic peroxides, such as lauroyl peroxide, cyclohexanone hydroperoxide, tert.-butyl peroctoate, tert.-butyl perpivalate, tert.-butyl perbenzoate, dichlorobenzoyl peroxide, benzoyl peroxide, di-tert.-butyl peroxide, tert.-butyl hydroperoxide, cumol hydroperoxide, peroxycarbonates such as diisopropyl peroxidicarbonate, dicyclohexyl peroxidicarbonate, diisooctyl peroxidicarbonate, sulphonyl peroxides such as acetylcyclohexylsulphonyl peracetate, sulphonylhydrazides, azo compounds such as azodiisobutyric acid nitrile as well as better water-soluble azo compounds as described, e.g., in DE-A-2841045. Inorganic peroxides such as hydrogen peroxide, potassium peroxodisulphate and ammonium peroxodisulphate are suited as well. The initiators decomposing in radicals can be used alone or in combination with reducing agents or heavy metal compounds. Such compounds are, e.g., sodium- or potassium pyrosulphite, formic acid, ascorbic acid, thiourea, hydrazine- or amine derivatives and RONGALIT (1-hydroxymethanesulphinic acid Na-salt). The heavy metal compounds can be present in oil-soluble as well as in water-soluble form. Examples of water-soluble heavy metal compounds are silver nitrate, halides and sulphates of 2- and 3-valent iron, cobalt, nickel and salts of titanium or vanadium in low valency stages. Examples of oil-soluble heavy metal compounds are cobalt naphthenate and the acetylacetone complexes of vanadium, cobalt, titanium, nickel and iron. The emulsion polymerisations take place at temperatures between 20° and 100° C., preferably between 40° and 85° C. The amount of other emulsifying agents that can be used in addition to the polymers I is 0° to 20%, preferably 1 to 5%, based on the monomers to be polymerised. Artionic as well as non-ionic emulsifying agents are suited therefore. As examples can be mentioned alkyl- and aryl sulphonates such as dodecylsulphonic acid Na-salt, the N-methyl taurinate product with oleic acid (HOSTAPON T) and sulphonated dodecylphenyl phenyl ethers (Dow FAX 2A1), alkyl- and aryl sulphates such as the sodium sulphate of oxethylated nonylphenol (HOSTAPAL B), poly(vinyl alcohol), oxethylated phenols, oleyl alcohol polyglycol ethers, oxethylated polypropylene glycol or natural products such as gelatine and fish glue. Carrying out the emulsion polymerisation can take place in such a way that an aqueous solution of polymer I, optionally together with other emulsifying agents, is prepared and then the monomers and the initiator are fed separately. It is also possible, however, to prepare only a part of polymer I in water, optionally together with other emulsifying agents and to feed the remainder together with the monomers, the initiator and optionally additional emulsifying agents in separate fluxes. Alternatively, one can proceed in such a way that an aqueous solution of polymer I, monomers, initiator and optionally other emulsifying agents are fed continuously or intermittently over the entire period of polymerisation and that only a determined amount of water is used. Further, the polymerisations according to the invention are likewise suited for carrying out a batch-wise process, according to which polymer I, monomer (mixture), initiator and optionally further emulsifying agents are applied together and brought to the desired polymerisation temperature. In a special embodiment of the emulsion polymerisation only a part of the monomers is first polymerised according to a batch-wise process, whereupon further monomers are fed, occasionally together with initiator and emulsifying agent. The applied and dropwise added monomer (mixture) can then be composed differently. If polymer I is being applied as an aqueous solution, it may be advantageous for the polymerisation to heat the receiver together with the initiator to 40° to 85° C. for some time, e.g. between 10 and 180 min, before adding the monomers. One can proceed e.g. as follows in the emulsion polymerisation according to the invention: Under nitrogen atmosphere an aqueous solution of polymer I together with potassium peroxidisulphate is prepared. The preparation is heated at 65° C. with stirring for some time, whereupon first an aqueous solution of a low-molecular emulsifying agent is added at once and then the monomer mixture within some period of time. After the temperature rise of the starting exothermic reaction is finished, the mixture is stirred at increased temperature, demonomerised at 90° C. under reduced pressure, cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water (1:1). After completion of the emulsion polymerisation in the illustrated way, a fine, aqueous polymer emulsion with average particle size between 30 and 500 nm has formed. The type of photographic material in which the polymer latices are incorporated according to the present invention and its field of use is not limited in any way. It includes photographic elements for graphic arts and for so-called amateur and professional black-and-white or colour photography, cinematographic recording and printing materials, X-ray diagnosis, diffusion transfer reversal photographic elements, low-speed and high-speed photographic elements, etc. However the advantages of the present invention become most perspicuous when the latices are incorporated in photographic materials setting high standards to dimensional stability, e.g. graphic arts contact materials as explained in the background section. Several types of commercial contact materials are available. Duplicating materials can be of the classical dark room type but in recent times preference is given to so-called daylight or roomlight contact materials which can be handled for a reasonable period under UV-poor ambient light. Also yellow light contact materials exist which can be handled under relative bright yellow light. Very insensitive daylight types are available which have to be exposed by strongly emitting metal-halogen sources. Less insensitive types are designed for exposure by quartz light sources. The daylight materials can be of the negative working type or of the direct positive working type. Usually in black-and-white materials the silver halide emulsion layer simply consists of just one layer. However double layers and even multiple layer packs are possible. Apart from the emulsion layer a photographic element usually comprises several non-light sensitive layers, e.g. protective layers, backing layers, filter layers and intermediate layers (or "undercoats"). All of these layers can be single, double or multiple. The polymer latices of the present invention can be present in all these layers, or in several of them, or in just one of them. In principle a mixture of two or more different latices can be used, or an invention latex can be mixed with a conventional plasticizer, but for normal practice just one representative of the new types will be sufficient. In the preferred embodiment of a graphic arts contact material the plasticizer is preferably present in the emulsion layer in a plasticizer/gelatin ratio ranging from 0.2 to 1. When present in the protective layer the preferred ratio range is between 0.2 and 1 equally. Apart from the polymer latex of the present invention the emulsion layer and the other hydrophilic layers can contain, according to their particular design and application, the typical and well-known photographic ingredients such as stabilizers, sensitizers, desensitizers, development accelerators, matting agents, spacing agents, anti-halation dyes, filter dyes, opacifying agents, antistatics, UV-absorbers, surfactants, gelatin hardeners such as formaldehyde and divinylsulphon. The composition of the silver halide emulsion incorporated in a photographic element of the present invention is not specifically limited and may be any composition selected from e.g. silver chloride, silver bromide, silver iodide, silver chlorobromide, silver bromoiodide, and silver chlorobromoiodide. However in the preferred embodiment of a contact material, especially a daylight material, emulsions rich in chloride are preferred. The photographic emulsion(s) can be prepared from soluble silver salts and soluble halides according to different methods as described e.g. by P. Glafkides in "Chimie et Physique Photographique", Paul Montel, Paris (1967), by G. F. Duffin in "Photographic Emulsion Chemistry", The Focal Press, London (1966), and by V. L. Zelikman et al in "Making and Coating Photographic Emulsion", The Focal Press, London (1966). Two or more types of silver halide emulsions that have been prepared differently can be mixed for forming a photographic emulsion. The average size of the silver halide grains may range from 0.05 to 1.0 μm, preferably from 0.2 to 0.5 μm. For daylight materials the average grain size is preferably comprised between 0.07 μm and 0.20 μm. The size distribution of the silver halide particles can be homodisperse or heterodisperse. The light-sensitive silver halide emulsions can be chemically sensitized as described e.g. in the above-mentioned "Chimie et Physique Photographique" by P. Glafkides, in the above-mentioned "Photographic Emulsion Chemistry" by G. F. Duffin, in the above-mentioned "Making and Coating Photographic Emulsion" by V. L. Zelikman et al, and in "Die Grundlagen der Photographischen Prozesse mit Silberhalogeniden" edited by H. Frieser and published by Akademische Verlagsgesellschaft (1968). However in the case of a contact daylight material the emulsion is preferably not chemically ripened and preferably contains relative high amounts of a desensitizer. The light-sensitive silver halide emulsions can be spectrally sensitized with methine dyes such as those described by F. M. Hamer in "The Cyanine Dyes and Related Compounds", 1964, John Wiley & Sons. Dyes that can be used for the purpose of spectral sensitization include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. Particularly valuable dyes are those belonging to the cyanine dyes, merocyanine dyes and complex merocyanine dyes. However in the particular case of a contact daylight material the emulsion is preferably not spectrally sensitized in view of the daylight stability. The silver halide emulsion(s) for use in accordance with the present invention may comprise compounds preventing the formation of fog or stabilizing the photographic characteristics during the production or storage of photographic elements or during the photographic treatment thereof. Many known compounds can be added as fog-inhibiting agent or stabilizer to the silver halide emulsion. The photographic material of the present invention may further comprise various kinds of surface-active agents in the photographic emulsion layer or in another hydrophilic colloid layer. Suitable surface-active agents include non-ionic agents such as saponins, alkylene oxides e.g. polyethylene glycol, polyethylene glycol/polypropylene glycol condensation products, polyethylene glycol alkyl ethers or polyethylene glycol alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkylamines or alkylamides, silicone-polyethylene oxide adducts, glycidol derivatives, fatty acid esters of polyhydric alcohols and alkyl esters of saccharides; anionic agents comprising an acid group such as a carboxy, sulpho, phospho, sulphuric or phosphoric ester group; ampholytic agents such as aminoacids, aminoalkyl sulphonic acids, aminoalkyl sulphates or phosphates, alkyl betaines, and amine-N-oxides; and cationic agents such as alkylamine salts, aliphatic, aromatic, or heterocyclic quaternary ammonium salts, aliphatic or heterocyclic ring-containing phosphonium or sulphonium salts. Such surface-active agents can be used for various purposes e.g. as coating aids, as compounds preventing electric charges, as compounds improving slidability, as compounds facilitating dispersive emulsification, as compounds preventing or reducing adhesion, and as compounds improving the photographic characteristics e.g higher contrast, sensitization, and development acceleration. Preferred surface-active coating agents are compounds containing perfluorinated alkyl groups. In case of a photographic colour material the typical ingredients like colour forming agents, mask forming agents, Development Inhibitor Releasing couplers, and other Photographic Useful Group releasing couplers can be present. The support of the photographic material can be a transparent base, preferably an organic resin support, e.g. cellulose nitrate film, cellulose acetate film, polyvinylacetal film, polystyrene film, polyethylene terephthalate film, polycarbonate film, polyvinylchloride film or poly-alpha-olefin films such as polyethylene or polypropylene film. The thickness of such organic resin film is preferably comprised between 0.07 and 0.35 mm. These organic resin supports are preferably coated with a subbing layer. On the other hand the support of the photographic material can be a paper base preferably a polyethylene or polypropylene coated paper base. The photographic material can be exposed according to its particular composition and application, and processed by any means or any chemicals known in the art depending on its particular application. The following preparative and photographic examples illustrate the present invention without however being limited thereto. EXAMPLES Examples of Synthesis The used polymers I are copolymers that are composed alternatingly to a wide extent, if not stated otherwise. Emulsion polymer 1 An aqueous solution of 40 g of polymer Ia-1 and 16 g of potassium peroxidisulphate in 800 ml of water was prepared under nitrogen atmosphere. The preparation was heated at 65° C. with stirring for 2 h, whereupon 240 ml of 1N sodium hydroxide solution, 640 g of 10% aqueous solution of HOSTAPON T and 4707 g of water were added at once. Then a monomer mixture consisting of 714.4 g of n-butyl acrylate, 869.6 g of methyl methacrylate and 16 g of acrylic acid was added within 1 min. The mixture was stirred at 65° C. for another 16 h, cooled, mixed with a 20% solution of 1000 ppm of phenol in ethanol/water (1:1) and filtered through a 100-μm filter. The obtained latex had a solids content of 21.9% (w/w), a pH of 6.6 and according to laser correlation spectroscopy an average particle size of 75 nm. Emulsion polymer 2 An aqueous solution of 80 g of polymer Ia-1 and 16 g of potassium peroxidisulphate in 1600 ml of water was prepared under nitrogen atmosphere. The preparation was heated at 65° C. with stirring for 2 h, whereupon 340 ml of 1N sodium hydroxide solution, 640 g of 10% aqueous solution of HOSTAPON T and 3820 g of water were added at once. Then a monomer mixture consisting of 714.4 g of n-butyl acrylate, 869.6 g of methyl methacrylate and 16 g of acrylic acid was added within 1 min. The mixture was stirred at 65° C. for another 16 h, cooled, mixed with a 20% solution of 1000 ppm of phenol in ethanol/water (1:1) and filtered through a 100-μm filter. The obtained latex had a solids content of 21.6% (w/w), a pH of 6.4 and according to laser correlation spectroscopy an average particle size of 133 nm. Emulsion polymer 3 500 g of an aqueous solution of 25 g of polymer Ia-1 together with 10 g of potassium peroxidisulphate was prepared under nitrogen atmosphere. The preparation was heated at 65° C. with stirring for 2 h, whereupon 150 ml of 1N sodium hydroxide solution, 400 g of 10% aqueous solution of HOSTAPON T and 2940 g of water were added at once. Then a monomer mixture consisting of 446.5 g of butyl acrylate, 543.5 g of methyl methacrylate and 10 g of acrylic acid was added within 15 min. After the temperature rise of the starting exothermic reaction had been completed, the mixture was stirred at 80° C. for another 2 h, demonomerised at 90° C., then cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water. The obtained latex had a solids content of 22.0% (w/w), a pH of 5.7 and according to laser correlation spectroscopy an average particle size of 61 nm. Emulsion polymer 4 With the restriction that instead of n-butyl acrylate an identic amount of ethyl acrylate was used, the polymerisation occurred as described under "emulsion polymer 3". The obtained latex had a solids content of 22.7% (w/w), a pH of 5.7 and according to laser correlation spectroscopy an average particle size of 82 nm. Emulsion polymer 5 25 g of a terpolymer consisting of 50 mol-% of maleic anhydride, 44 mol-% of α-diisobutylene and 6 mol-% of styrene were dissolved in a mixture of 3161 g of water and 431 ml of 1N sodium hydroxide solution (polymer Ig-1) and mixed with 10 g of potassium peroxidisulphate under nitrogen atmosphere. The mixture was heated at 65° C. with stirring for 2 h and then 400 ml of a 10% aqueous solution of HOSTAPON T were added quickly. Thereupon the monomer mixture consisting of 446.5 g of butyl acrylate, 543.5 g of methyl methacrylate and 10 g of acrylic acid was added within 15 min. After the temperature rise of the starting exothermic reaction had been completed, the mixture was stirred at 80° C. for another 2 h, demonomerised at 90° C., then cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water. The obtained latex had a solids content of 21.6% (w/w), a pH of 6.7 and according to laser correlation spectroscopy an average particle size of 79 nm. Emulsion polymer 6 Unter nitrogen atmosphere a mixture was prepared of 640 g of water, 540 mg of RONGALIT C and 220 g of a 18.2% aqueous solution of a terpolymer that in a first stage was prepared from 50 mol-% of maleic anhydride, 44 mol-% of α-diisobutylene and 6 mol-% of styrene and thereupon was reacted with an amount of sodium taurinate aequimolar to that of maleic anhydride. The mixture was heated at 50° C. and then 25% of both solutions I and II were added at once. It was stirred at this temperature for 1 h whereupon the remainder of both solutions I and II was added simultaneously within 3 h. solution I: 1.60 g of ammonium peroxidisulphate 140 g of water solution II: 200 g of ethyl acrylate After the addition was finished the mixture was stirred at 50° C. for another 6 h. The latex formed was degassed under reduced pressure at 60° C. and filtered through a 100-μm cloth. It had a solids content of 23.5% and according to laser correlation spectroscopy an average particle size of 52 nm. Emulsion polymer 7 100 g of a terpolymer which in a first stage was prepared from 50 mol-% of maleic anhydride, 44 mol-% of α-diisobutylene and 6 mol-% of styrene and thereupon was reacted with an amount of sodium taurinate equimolar to that of the maleic anhydride, were dissolved in 2275 g of water and mixed with 10 g of potassium peroxidisulphate under nitrogen atmosphere. The preparation was heated at 65° C. with stirring for 1 h and then at the same time a monomer mixture consisting of 111.65 g of ethyl acrylate, 135.9 g of methyl methacrylate and 2.5 g of acrylic acid as well as 36.25 g of a 3.45% aqueous solution of potassium peroxidisulphate was added in 5 min. Stirring at 80° C. was continued for another 30 min whereupon once again a monomer mixture consisting of 334.5 g of ethyl acrylate, 407.6 g of methyl methacrylate and 7.5 g of acrylic acid as well as 108.75 g of a 3.45% aqueous solution of potassium peroxidisulphate were added at the same time in 90 min. The mixture was stirred at 80° C. for another h, demonomerised at 90° C., then cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water. The pH of the obtained latex was increased from 4.5 to 5.5 by adding 25 ml of 1N sodium hydroxide solution. The latex had a solids content of 26.7% (w/w) and according to laser correlation spectroscopy an average particle size of 78 nm. Emulsion polymer 8 Unter nitrogen atmosphere 100 g of polymer Ie-1 were dissolved in 2275 ml of water and mixed with 10 g of potassium peroxidisulphate. The further reactions occurred as described under "Emulsion polymer 3". The pH of the obtained latex was 4.8 and was increased to 5.5 by adding 20 ml of 1N sodium hydroxide solution. The latex had a solids content of 26.4% (w/w) and according to laser correlation spectroscopy an average particle size of 286 nm. Emulsion polymer 9 3340 g of an aqueous solution containing 25 g of polymer Ia-1 and 10 g of potassium peroxidisulphate was prepared under nitrogen atmosphere. This solution was heated at 65° C. with stirring for 2 h and thereupon at once 150 ml of 1N sodium hydroxide solution and 400 ml of a 10% aqueous solution of HOSTAPON T were added. Thereupon the monomer mixture consisting of 990 g of ethyl acrylate and 10 g of acrylic acid was added within 15 min. After the temperature rise of the starting exothermic reaction had been completed, the mixture was stirred at 80° C. for another 2 h, demonomerised at 90° C. then cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water. The obtained latex had a solids content of 22.7% (w/w), a pH of 5.6 and according to laser correlation spectroscopy an average particle size of 129 nm. Emulsion polymer 10 With the restriction that a modified monomer mixture consisting of 840 g of ethyl acrylate, 100 g of methyl methacrylate, 10 g of acrylic acid and 50 g of acetoacetoxyethyl methacrylate was used, the polymerisation occurred as described under "Emulsion polymer 9". The obtained latex had a solids content of 22.2% (w/w), a pH of 5.9 and according to laser correlation spectroscopy an average particle size of 108 nm. Emulsion polymer 11 With the restriction that a modified monomer mixture consisting of 790 g of ethyl acrylate, 100 g of methyl methacrylate, 10 g of acrylic acid and 100 g of acetoacetoxyethyl methacrylate was used, the polymerisation occurred as described under "Emulsion polymer 9". The obtained latex had a solids content of 22.3% (w/w), a pH of 5.8 and according to laser correlation spectroscopy an average particle size of 89 nm. Emulsion polymer 12 3340 g of an aqueous solution containing 25 g of polymer If-1 and 10 g of potassium peroxidisulphate was prepared under nitrogen atmosphere. This solution was heated at 65° C. with stirring for 2 h and thereupon 159 ml of 1N sodium hydroxide solution and 400 ml of a 10% aqueous solution of HOSTAPON T were added quickly. Thereupon the monomer mixture consisting of 446.5 g of butyl acrylate, 543.5 g of methyl methacrylate and 10 g of acrylic acid was added within 15 min. After the temperature rise of the starting exothermic reaction had been completed, the mixture was stirred at 80° C. for another 2 h, demonomerised at 90° C., then cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water. The obtained latex had a solids content of 21.7% (w/w), a pH of 6.1 and according to laser correlation spectroscopy an average particle size of 86 nm. Emulsion polymer 13 3340 g of an aqueous solution containing 25 g of polymer Ia-1 and 10 g of potassium peroxidisulphate was prepared under nitrogen atmosphere. This solution was mixed at once with 150 ml of 1 N sodium hydroxide solution and 400 ml of a 10% aqueous solution of HOSTAPON T. Thereupon the monomer mixture consisting of 446.5 g of butyl acrylate, 543.5 g of methyl methacrylate and 10 g of acrylic acid was added within 15 min. After the temperature rise of the starting exothermic reaction had been completed, the mixture was stirred at 80° C. for another 2 h, demonomerised at 90° C., then cooled and mixed with a 20% solution of 1000 ppm of phenol in ethanol/water. The obtained latex had a solids content of 19.8% (w/w), a pH of 6.3 and according to laser correlation spectroscopy an average particle size of 74 nm. Examples of Physical Evaluation in Photographic Materials Photographic-physical example 1 In this example the dimensional stability of photographic material samples comprising invention latices 1 and 2 is compared to samples comprising control plasticizer polyethylacrylate (C-1). The photographic material was prepared as follows. A direct positive pure silver bromide emulsion was precipitated by a double jet technique and internally sensitized. The emulsion was then externally fogged using thiourea dioxide as to obtain the desired sensitivity. Finally the emulsion was divided in aliquot portions and different latices were added to each portion according to table 1. The coating solutions thus prepared were applied to a subbed polyethylene terephtalate base at a silver coverage, expressed as silver nitrate, of 3.18 g/m2, and a gelatin coverage of 2.7 g/m2. A protective layer was applied containing gelatin hardened with formaldehyde at a coverage of 0.7 g/m2. The sensitivity and gradation were determined as follows. The coated samples were exposed to an UV-white light source (AGFA CDL 2001S) and developed in a conventional Phenidone-hydroquinone developing solution (AGFA G4000), fixed, washed and dried in an AGFA RAPILINE 66A processor. The direct positive sensitivity was determined at density 0.1 above minimum density and expressed as relative log H value, higher figure meaning higher sensitivity. The gradation was measured as the slope of the linear part of the sensitometric curve. The scratch resistance was measured by scratching the coated samples with a ball point under a gradually increasing load. The value of the scratch resistance corresponds to the load in grams required for cutting through the emulsion layer completely. The dimensional change during processing is evaluated as follows. Each coated sample was conditioned in an acclimated room for at least 6 hours to a relative humidity of 30 or 60% respectively at 22° C. Two holes with a diameter of 5 mm were punched at a distance of 200 mm in each film sample having dimensions of 35 mm×296 mm. The exact interval between those holes was measured with an inductive half-bridge probe (TESA FMS100) having an accuracy of 1 μm, whereby this distance was called X μm. Subsequently the film material was subjected to processing in an automatic apparatus, a PAKO 26RA the dryer of which was equipped with an air-inlet. The samples were developed at 38° C., fixed at 33° C., rinsed without temperature control, and dried, whereby air of 22° C. and of 30% RH or of 60% RH respectively was provided through the air-inlet and whereby the temperature was raised upto 35° C. in the case of 60% RH, or 55° C. in the case of 30% RH. The distance between the two holes in the film is measured again after an acclimatisation period of 3 hours and is expressed as Y μm. The dimensional stability is calculated as (Y-X).5 and expressed in μm/m. The results are summarized in tables 1a and 1b. TABLE 1a ______________________________________ latex dimensional change Sample No. type g/m.sup.2 30% RH 60% RH scratch res. ______________________________________ 1 -- -- +209 -71 500 2 C-1 0.66 +172 -53 1300 3 C-1 1.40 +148 -66 850 4 C-1 2.20 +132 -52 650 5 e.p. 2 0.66 +161 -41 >1600 6 e.p. 2 1.40 +148 -48 1075 7 e.p. 2 2.20 +143 -57 775 8 e.p. 1 0.66 +172 -36 1450 9 e.p. 1 1.40 +147 -41 1100 10 e.p. 1 2.20 +107 -56 825 ______________________________________ TABLE 1b ______________________________________ Sample No latex type sensitivity gradation ______________________________________ 1 -- 1.49 4.6 2 C-1 1.37 4.1 3 C-1 1.34 3.8 4 C-1 1.33 3.4 5 e.p. 2 1.38 4.2 6 e.p. 2 1.33 3.7 7 e.p. 2 1.28 3.5 8 e.p. 1 1.38 4.2 9 e.p. 1 1.34 3.9 10 e.p. 1 1.33 3.6 ______________________________________ The photographic results with the invention latices are similar to those with the control latex. However it is clear from table Ia that the scratch resistance/dimensional change relation is substantially improved when using the invention latices. Photographic-physical example 2 In this example the physical properties of photographic samples containing control or invention latices were compared at a rather low gelatin coverage. The silver bromide emulsion was prepared as in example 1. The respective latices were added to the emulsion in an amount corresponding to a coverage of 1.5 g/m2 after coating. The coating solutions were applied to a polyethylene terephtalate base at a coverage of 3.18 Ag/m2 and 1.5 g gelatin/m2. The same protective layer was applied as in example 1. The results are summarized in table 2. TABLE 2 ______________________________________ latex scratch dimensional change Sample No. type gradation resistance 30% RH ______________________________________ 1 C-1 4.0 140 +113 2 e.p. 3 4.0 230 +108 3 e.p. 4 4.1 260 +132 4 e.p. 5 4.0 250 +119 5 e.p. 7 4.3 230 +121 6 e.p. 13 3.9 270 +129 ______________________________________ Due to the relative low gelatin coverage the scratch resistance values were lower than in example 1. Again it is clear that the scratch resistance/dimensional change relation was better for the samples containing invention latices. Photographic-physical example 3 In this example photographic samples are compared in which both the emulsion layer and the protective layer contain control or invention plasticizers. The silver bromide emulsion was prepared as in example 1. The respective latices were added to the emulsion in an amount corresponding to a coverage of 1.5 g/m2 after coating. The coating solutions were applied to a polyethylene terephtalate base at a coverage of 3.18 Ag/m2 and 1.5 g gelatin/m2. The protective layer was applied containing formaldehyde hardened gelatin at a coverage of 0.7 g/m2 and a latex at a coverage of 1.4 g/m2. The results are summarized in Table 3. TABLE 3 ______________________________________ latex scratch dimensional Sample No. type gradation resistance change 30% RH ______________________________________ 1 C-1 4.4 160 +95 2 e.p. 3 4.5 180 +118 3 e.p. 7 4.4 210 +115 4 e.p. 8 4.3 190 +116 5 e.p. 13 4.4 170 +108 ______________________________________ Although the results are less pronounciated as in the previous examples it is still clear that the invention latices gave rise to better scratch resistance values for acceptable dimensional stability values. We claim: 1. Photographic material comprising a support, at least one silver halide emulsion layer, and optionally one or more other hydrophilic gelatinous layer(s), characterized in that at least one of said emulsions or other hydrophilic gelatinous layer(s) contains a polymer latex with an average particle size of less than 500 μm, which is obtained by subjecting to radical emulsion polymerisation one or more radical-polymerisable monomers, whose emulsifier-free homopolymers or copolymers possess a glass transition temperature below 65° C., in the presence of a water-soluble polymer of formula I ##STR13## wherein Z is --CH2 --CR1 R2 --(I.1), or ##STR14## M represents H, Na, K, Li, or NH4, R1 represents H or CH3,R2 represents H, C1 -C6 alkyl, aryl, --(CH2)m --OCO--R5, wherein R5 corresponds to C1 -C8 alkyl and m is 0 or 1, ##STR15## A represents OM, OR3, NH2, NHR3, O--R4 --(SO3 M)n or NH--R4 --(SO3 M)n, wherein R3 represents C1 -C4 alkyl, R4 represents an aliphatic or aromatic residue of 1 to 10 C atoms, n is 1 or 2, and x,y are chosen in such a way that the weight-average molecular weight of polymer I is comprised between 5,000 to 500,000, and the ratio x:y is comprised between 1:4 and 1:1. 2. Photographic material according to claim 1 wherein R2 is chosen from the group consisting of --CH3, --C2 H5, --C4 H9, --CH2 C(CH3)3), phenyl and tolyl. 3. Photographic material according to claim 1 wherein R4 is derived from a residue chosen from the group consisting of C1 -C4 alkane, benzene, methylbenzene and naphthalene. 4. Photographic material according to claim 1 wherein said radical-polymerisable monomers comprise a mixture of n.-butyl acrylate, methyl methacrylate and acrylic acid. 5. Photographic material according to claim 1 wherein said polymer latex is present in the emulsion layer and/or in the protective layer in a latex/gelatin ratio ranging from 0.2 to 1. 6. Photographic material according to claim 1 wherein said material is a graphic arts contact material. 7. Photographic material according to claim 1 wherein said one or more radical-polymerisable monomers are those whose glass transition temperature of their emulsifier-free homopolymers or copolymers is below 30° C.

1994-08-12

en

1995-12-26

US-50991083-A

Process for the production of plastic based on polyisocyanates ABSTRACT The present invention is directed to a process for the production of plastics based on an isocyanate-polyaddition product by (1) forming an isocyanate group-containing prepolymer from (a) a compound which has a molecular weight of from 146 to about 10,000, is substantially free from hydroxyl groups, contains at least two terminal carboxyl groups and optionally contains ether and/or ester groups, (b) excess quantities of an organic nonaromatic polyisocyanate which has at least one cyclohexane ring and exclusively contains aliphatically- and/or cycloaliphatically-bound isocyanate groups and (c) up to 10 equivalent percent, based on the isocyanate-reactive groups in component (a), of a compound which is monofunctional for the purposes of the isocyanate-addition reaction and, (2) reacting the product of step (1) with (d) a chain-lengthening agent such as water, a polyamine containing at least two primary and/or secondary amino groups or hydrazine or a derivative thereof containing at least two primary and/or secondary amino groups. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the production of plastics, which are substantially free from urethane groups and which are based on polyisocyanates, by the reaction of aliphatic or cycloaliphatic polyisocyanates with compounds which are substantially free from hydroxyl groups and urethane groups and which have isocyanate-reactive groups, to produce the corresponding isocyanate group-containing prepolymers and subsequently chain-lengthening these prepolymers with water, polyamines or hydrazines. 2. Description of the Prior Art The reaction between carboxyl groups and isocyanate groups which is known in principle and results in amide groups has until now not been used on a large scale for the production of plastics based on polyisocyanates, apart from the production of high molecular weight thermoplastic copolyamides (see, for example K. B. Onder et al., Polym. Prep. Amer. Chem. Soc. Div. Polym. Chem., 21, (1980), 132 ff). The reason for this may be seen in the low reactivity of carboxyl groups towards isocyanate groups, which results in the finding that, during the reaction of compounds containing carboxyl groups with polyisocyanates, secondary reactions always take place which result in an undesirable swelling of the reaction mixtures. Thus, for example during the reaction of the melt of polyesters containing carboxyl groups with conventional polyisocyanates, for example toluylene diisocyanate, highly cross-linked and completely insoluble products are obtained long before the release of carbon dioxide which would theoretically be expected. On the other hand, amide groups are more thermo-stable than urethane groups, so that it was possible to proceed from the fact that plastics which were produced using reaction components containing carboxyl groups and were based on polyisocyanates have an increased stability to temperature influences, compared to conventional polyurethanes. Thus, an object of the present invention is to provide a method of producing such polyisocyanate-based plastics which allows the production thereof in a substantially by-product-free form. Surprisingly, this object may be achieved by the process according to the present invention which is described in more detail in the following. SUMMARY OF THE INVENTION The present invention is directed to a process for the production of plastics based on an isocyanatepolyaddition product by (1) forming an isocyanate group-containing prepolymer from (a) a compound which has a molecular weight of from 146 to about 10,000, is substantially free from hydroxyl groups, contains at least two terminal carboxyl groups and optionally contains ether and/or ester groups, (b) excess quantities of an organic nonaromatic polyisocyanate which has at least one cyclohexane ring and exclusively contains aliphatically- and/or cycloaliphatically-bound isocyanate groups and (c) up to 10 equivalent percent, based on the isocyanate-reactive groups in component (a), of a compound which is monofunctional for the purpose of the isocyanate-addition reaction and (2) reacting the product of step (1) with (d) a chain-lengthening agent such as water, a polyamine containing at least two primary and/or secondary amino groups or hydrazine or a derivative thereof containing at least two primary and/or secondary amino groups. DETAILED DESCRIPTION OF THE INVENTION Component (a) which is to be used in the present process is selected from organic compounds having an (average) molecular weight (which may be calculated from the content of terminal groups) of from 146 to about 10,000, preferably from about 500 to 4,000, most preferably from about 1000 to 3500, which are substantially free from hydroxyl groups, optionally contain ether and/or ester groups, are optionally present as a mixture and which contains at least 2, preferably 2 or 3, most preferably 2, terminal carboxyl groups. The term "free from hydroxyl groups" means in this connection that in these compounds there is a maximum of 10, preferably a maximum of 5, hydroxyl groups per 100 carboxyl groups. The compounds which are suitable as component (a) are preferably either free polycarboxylic acids having a molecular weight of at least 146 of the type exemplified below as components for the production of polyesters containing carboxyl groups, or are polyesters, polyethers, polyacetals or polyamines which contain terminal carboxyl groups. Polyesters or polyether containing terminal carboxyl groups are preferably used as component (a). Of course, mixtures of different compounds corresponding to the definition mentioned above may also be used in the present process. Polyesters containing carboxyl groups are, for example the known reaction products of polyhydric, preferably dihydric, and optionally also trihydric alcohols with polybasic, preferably dibasic, carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof may also be used for the production of the polyesters containing terminal carboxyl groups. The polycarboxylic acids may be of an aliphatic, a cycloaliphatic, an aromatic and/or a heterocyclic nature and may optionally be substituted, for example by halogen atoms, and/or may be unsaturated. The following are mentioned as examples of such acids: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, endomethylene-tetraphthalic acid anhydride, glutaric acid anhyride, maleic acid, maleic acid anhyride, fumaric acid, dimeric and trimeric fatty acids, such as oleic acid, optionally in admixture with monomeric fatty acids, terephthalic acid dimethyl ester and terephthalic acid bis-glycol ester. The following, for example are included as polyhydric alcohols: ethylene glycol, propylene glycol-(1,2) and -(1,3), butylene glycol-(1,4), -(1,3) and -(2,3), hexane diol-(1,6), octane diol-(1,8), neopentyl glycol, cyclohexane dimethanol (1,4-bis-hydroxymethyl-cyclohexane), 2-methyl-1,3-propane diol, glycerin, trimethylolpropane, hexane triol-(1,2,6), butane triol-(1,2,4), trimethylolethane, pentaerythritol, quinitol, mannitol, sorbitol, methyl glycoside, also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols. Suitable polyethers containing terminal carboxyl groups may be obtained, for example by reacting polyether polyols which are known from polyurethane chemistry with dicarboxylic acids or dicarboxylic acid anhydrides of the type exemplified above. Polyether polyols which are suitable for this purpose include, for example the addition products of alkylene oxides, for example ethylene oxide and/or propylene oxides, to suitable starting molecules for example, water, ethylene glycol, propylene glycol, trimethylolpropane and/or glycerin. In principle, any reaction products (which correspond to the above definition and contain free carboxylic groups) prepared by reacting dicarboxylic acids or dicarboxylic acid anhydrides of the exemplified type with the compounds known from polyurethane chemistry which have isocyanate-reactive groups, i.e. in particular hydroxyl groups or amino groups, may be used as component (a). For example, the derivatives of previously produced polyester polyols, polycarbonate diols, polycaprolactone diols, polyacetal diols and polyester amines or polyamides containing amino groups are to be included with these reaction products. The preliminary products containing hydroxyl or amino groups are converted into the corresponding compounds containing terminal carboxyl groups by a reaction with dicarboxylic acids or dicarboxylic acid anhydrides, generally within a temperature range of from about 80° to 150° C. The exemplified dicarboxylic acid anhydrides are preferably used for the modification reaction. This reaction may be catalyzed with bases or tertiary amines, if required. It is also possible to use compounds which contain ionic groups, in particular sulphonate groups, and which have terminal carboxyl groups as component (a). Compounds of this type may be obtained, for example by reacting the sulphonate diols described in U.S. Pat. No. 4,108,814 with dicarboxylic acid anhydrides of the exemplified type. It is also possible to use nonionically, hydrophilically-modified compounds containing terminal carboxyl groups as component (a), as they may be obtained, for example by reacting the exemplified dicarboxylic acid anhydrides with diols which have side chains and contain ethylene oxide units of the type mentioned in U.S. Pat. Nos. 3,905,929 and 4,190,566. Such ionically or nonionically, hydrophilically-modified compounds are simultaneously used in particular for the production of aqueous dispersions of the products according to the present invention. In principle, it is also possible simultaneously to use the exemplified hydrophilic components containing hydroxyl groups which are not modified with dicarboxylic acid anhydrides for the hydrophilic modification of the products according to the present process, provided that the total content in component (a) of hydroxyl groups corresponds to the above-mentioned definition. Compounds suitable as component (b) are nonaromatic polyisocyanates, having at least one cyclohexane ring and containing exclusively aliphatically- and/or cycloaliphatically-bound isocyanate groups. Diisocyanates containing at least one cycloaliphatically-bound isocyanate group are preferably used, and diisocyanates containing two cycloaliphatically-bound isocyanate groups are more preferably used. For example, the following polyisocyanates are suitable as component (b): perhydrogenated xylylene diisocyanates, diisocyanatomethyl-tricyclodecanes which may be present as isomer mixtures, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (IPDI), 4,4'-diisocyanato-dicyclohexyl-methane, 4,4'-diisocyanato-dicyclohexyl-propane (2,2), or the phosgenation products of perhydrogenated aniline/formaldehyde condensates which are present as isomer or homologue mixtures. Polyisocyanates which contain biuret or isocyanurate groups and are based on the simple aliphatic or cycloaliphatic diisocyanates exemplified may also be used. Polyamines containing at least two primary and/or secondary amino groups, preferably diamines and/or hydrazines containing two primary and/or secondary amino groups, are particularly included as component (d), i.e. as chain-lengthening agents, in addition to water, when the present process is being carried out. Compounds suitable as component (d) particularly include those corresponding to the following general formula: (A).sub.n (NHB).sub.2 wherein A represents a saturated aliphatic hydrocarbon radical having from 2 to 12, preferably from 2 to 6 carbon atoms, a saturated cycloaliphatic hydrocarbon radical having from 4 to 15, preferably from 6 to 10, carbon atoms, an aromatic hydrocarbon radical having from 6 to 15, preferably from 6 to 13, carbon atoms or an araliphatic hydrocarbon radical having from 7 to 13 carbon atoms, at least two carbon atoms being positioned between the two amino groups; B represents hydrogen or an alkyl radical having from 1 to 18 carbon atoms, preferably hydrogen; and n represents 0 or 1. The following are included as examples suitable for component (d): ethylene diamine, 1,2-propylene diamine, 1,3-propylene diamine, hexamethylene diamine, 1-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane (IPDA), 1,4-diaminocyclohexane, 4,4'-diamino-dicyclohexylmethane, 2,4- and 2,6-toluylene diamine and mixtures thereof or 4,4'-diaminodiphenyl-methane, or mixtures of such amines; as well as N-methyl-diethylene triamine, hydrazine, methyl hydrazine, dodecyl hydrazine, N,N'-dimethyl hydrazine or the hydrates of such hydrazines. Diamines which contain ionic centers, for example the N-(ω-amino-alkane)-ω'-amino alkane sulphonic acid salts which are described in German Offenlegungsschrift No. 2,035,732 may particularly also be used as component (d) in the production of aqueous dispersions of plastics based on polyisocyanates according to the present invention. During the production of aqueous dispersions of plastics based on the polyisocyanates according to the present process, it is also often appropriate to use diamines or hydrazines containing at least one reversibly blocked amino group as components (d). These are compounds which are selected from ketimines, ketazines, oxazolidines, aldazines, aldimines and carbonates. From compounds of this type are produced the amines or hydrazines on which they are based under the hydrolytic influence of water. The production of aqueous dispersions of plastics based on polyisocyanates with the use of such blocked chain-lengthening agents is described, for example, in U.S. Pat. Nos. 4,192,937; 4,269,748 and 4,292,266 or in German Offenlegungsschrift No. 2,725,589. The ketamines described in German Offenlegungsschrift No. 2,725,589 and the azines described in U.S. Pat. No. 4,269,748 are particularly preferred as component (d) having at least partly blocked amino groups. When carrying out the present process using these particular chain-lengthening agents according to the methods disclosed in the above-mentioned publications, it is only essential for at least 50%, preferably for more than about 85%, of the amino groups present in the amine or hydrazine component to be present in a blocked form and accordingly, for the amines to contain on statistical average a maximum of 1 mol, preferably a maximum of about 0.30 mol, of free amino groups per mol of polyamine, preferably diamine. Examples of blocked chain-lengthening agents of the type mentioned include acetone hydrazone, acetonazine, the bis-ketimine of IPDA and acetone, the homologous compounds based on methylethyl ketone or on methylisobutyl ketone or acetaldazine. The bis-ketimines of IPDI mentioned, and acetone hydrazone or acetonazine are preferred as component (d) having blocked amino groups. In a first stage of the present process, a prepolymer containing isocyanate groups is produced from component (a) and component (b). During this reaction, the reaction components are generally used in quantities corresponding to an equivalent ratio of isocyanate groups to isocyanate-reactive groups (in particular carboxyl groups) of from about 1.2:1 to 3:1, preferably from about 1.4:1 to 3:1. The reaction components are preferably reacted in substance, such that they are mixed together at from about 20° to 120° C. and are heated as quickly as possible to a temperature of from about 130° to 200° C., preferably from about 140° to 170° C., and are reacted at this temperature until the end of the release of carbon dioxide. The reaction may be carried out under an inert gas, such as nitrogen, and/or in the presence of a catalyst. Examples of suitable catalysts particularly include tertiary amines, alcoholates or phenolates and organometallic compounds, for example lithium methylate, sodium methylate, potassium methylate, lithium-t-butylate, sodium-t-butylate, potassium-t-butylate, sodium phenolate, lithium acetate, sodium acetate, potassium acetate, the alkali metal alcoholates of 2-ethyl-hexanol and the alkali metal salts of 2-ethyl-caproic acid. The following are also mentioned: lead octoate, tin octoate, nickel oleate, nickel acetylacetonate, dibutyl-tin-dilaurate, triethylamine or triethylenediamine. The catalysts may optionally be deactivated at the end of the reaction. For this purpose, the reaction products are mixed with from about 100 to 1000 ppm of neutralizing, acetylating or alkylating substances. Substances of this type include for example: hydrogen chloride, benzoyl chloride, ethyl iodide, dimethyl sulphate, sulphur or complex-formers. In principle, the NCO prepolymers may also be produced in the presence of inert, high-boiling solvents. Examples of such solvents include sulpholane, dimethyl formamide, N-methyl-pyrrolidone, diphenyl ether or diphenyl sulphone. Following production and before further reaction thereof, the NCO prepolymers may be diluted with inert solvents, the boiling point of which is now uncritical. Solvents suitable for this purpose particularly include acetone, methylethyl ketone, tetrahydrofuran, dioxane, ethyl acetate or toluene, in addition to the solvents mentioned above. In one embodiment of the present process, in particular during the production of aqueous dispersions of plastics based on polyisocyanates according to the present process, it may be appropriate simultaneously to use an additional starting component (c) in the production of the NCO prepolymers. This particular component (c) which is preferably used in admixture with component (a) is a reaction component which is monofunctional for the purposes of the isocyanate-addition reaction and has a molecular weight of from about 500 to 4000, preferably from about 800 to 2500. The isocyanate-reactive groups of component (c) are generally hydroxyl groups or preferably carboxyl groups. Preferred compounds for component (c) are monohydric polyether alcohols having ethylene oxide units and optionally also propylene oxide units or the reaction products thereof, containing carboxyl groups, with dicarboxylic acid anhydrides of the type exemplified above. Component (c) generally contains at least about 50%, preferably at least about 80%, by weight, of structural ethylene oxide units. They are produced by alkoxylation, preferably ethoxylation, of monofunctional starting molecules, for example ethanol or n-butanol, after which the above-mentioned modification reaction with dicarboxylic acid anhydride may optionally be carried out. If such component (c) is simultaneously used in the production of the NCO prepolymers, the quantity thereof, based on the total of components (a) and (b), is a maximum of about 15%, preferably a maximum of about 10%, by weight. The use of component (c) containing hydroxyl groups is particularly possible, provided that the total quantity of hydroxyl groups present in the mixture of components (a) and (c) amounts to a maximum of about 10% preferably a maximum of about 5%, of all the isocyanate-reactive groups which are present in this mixture. When component (c) is simultaneously used in the production of the NCO prepolymers, the quantity of polyisocyanate (component (b)) must, of course, be increased accordingly, so that the above-mentioned conditions with respect to the equivalent ratio of isocyanate groups to isocyanate-reactive groups are still fulfilled. It may be appropriate to compensate for the chain-terminating effect of monofunctional component (c) by the simultaneous use of a corresponding quantity of at least trifunctional components (a) and/or (b) and/or (d). The NCO prepolymers produced from components (a), (b) and optionally (c) are reacted with the chain lengthening agent (d) in the second stage of the present process. Apart from the use of high excesses of water during the use thereof as a chain-lengthening agent in the production of aqueous dispersions of the polyisocyanate-based plastics, the chain-lengthening agents are generally used in quantities such that from about 0.5 to 1.5, preferably from about 0.7 to 1.1, in particular about 1, gram equivalent of amino groups of the chain-lengthening agent (d), which are optionally partly blocked in a reversible manner, are available per mol of isocyanate groups of the prepolymer. When water is used as a chain-lengthening agent in the production of non-dispersed polyisocyanate-based plastics, suitable quantities of water are used, and water may be considered as a difunctional chain-lengthening agent. During the production of aqueous dispersions of polyisocyanate-based plastics with the simultaneous use of water and amine or hydrazine chain-lengthening agents which are optionally partly blocked, the quantity of water is not considered in the calculation of the quantity of amine or hydrazine chain-lengthening agents. If water is used as the chain-lengthening agent (d), an embodiment of the present process is also possible according to which the chain-lengthening reaction of the NCO prepolymer takes place under the influence of atmospheric moisture. According to this embodiment of the present process, the prepolymers containing NCO groups are processed as a moisture-hardenable one-component system, optionally after a "pre-lengthening" operation with less than stoichiometric quantities of amine or hydrazine chain-lengthening agents having exclusively free amino groups. For example, in this procedure, the chain-lengthening reaction is carried out after processing the NCO prepolymers (which are optionally pre-lengthened) as coating agents for substrates which cure under the influence of atmospheric moisture to produce thermostable coatings. In this embodiment of the present process, the NCO prepolymers which are optionally pre-lengthened may, of course, be provided with auxiliaries and additives which are conventional in coating technology, for example, lacquer solvents, pigments, flow auxiliaries and fillers or the like, before they are processed. During the reaction of the NCO prepolymers with water and/or with amine or hydrazine chain-lengthening agents of the exemplified type within the above-mentioned ranges, in particular during the stoichiometric reaction of the NCO prepolymers with chain-lengthening agent (d), valuable polyisocyanate-based plastics are produced which are substantially free of urethane groups, and the mechanical properties of which may be varied within wide ranges by a suitable choice of the type and particularly the functionality of the starting materials. The reaction of the NCO prepolymers with the chain-lengthening agents may be carried out in solvent-free manner or in the presence of solvents of the type exemplified above. Thus, for example, the process according to the present invention is particularly suitable for the production of physically drying lacquer solutions, in which case NCO prepolymers which are substantially produced from linear starting materials (a) and (b), and into which small quantities of monofunctional isocyanates, for example stearyl isocyanate, are optionally incorporated for the purpose of controlling the chain-termination are reacted in lacquer solvents of the type exemplified above with preferably stoichiometric quantities of chain-lengthening agent (d). Aqueous dispersions of the polyisocyanate-based plastics are produced according to a preferred embodiment of the present process. For this purpose, components (a), (c) and/or (d) of the exemplified type containing ionic centers and/or nonionic, hydrophilic groups are preferably simultaneously used in a quantity ensuring the dispersibility of the isocyanate-polyaddition products while the present process is being carried out. Moreover, either the chain-lengthening reaction of the NCO prepolymers takes place in an aqueous medium, i.e., in a high excess of water, based on the isocyanate groups of the prepolymer, or the polyisocyanate-based plastics which are produced in the absence of excess quantities of water are converted into an aqueous dispersion following production thereof. During the production of aqueous dispersions, the hydrophilic components mentioned are generally used in a quantity such that the polyisocyanate-based plastics which are finally dispersed in water contain up to about 45 milliequivalents of ionic centers, in particular of sulphonate groups, per 100 g of solids and/or contain up to about 30%, preferably to about 20%, by weight of ethylene oxide units positioned in polyether chains, one of these characteristic numbers having, of course, to be other than 0, so that there is a quantity of hydrophilic centers ensuring the dispersibility of the polyisocyanate-based plastics. It is largely unimportant whether the hydrophilic centers have been incorporated into the products of the process via component (a), (c) or (d) or via several of these components. When producing the polyisocyanate-based plastics in the absence of dispersing water, the present process is preferably carried out in the presence of a hydrophilic solvent, for example N-methyl-pyrrolidone, dioxane or acetone, after which the aqueous dispersion is produced by mixing the thus-obtained solution of the products of the present process with water, optionally removing any readily volatile solvents, such as acetone, by distillation after mixing with water. It is also possible during the production of aqueous dispersions to mix, for example, a hydrophobic NCO prepolymer of the exemplified type with a hydrophilically-modified NCO prepolymer of the exemplified type, so that the total quantity of hydrophilic groups in the mixture corresponds to the above-mentioned quantities, and it is then possible to convert the mixture into the end product by reaction with component (d). According to one preferred embodiment for the production of aqueous dispersions of the products according to the present process, the chain-lengthening reaction of the optionally hydrophilically-modified NCO prepolymer produced from components (a), (b) and optionally (c) takes place by the reaction thereof with aqueous solutions of diamines of the types exemplified above, optionally containing ionic centers, or with hydrazines of the type exemplified above, and the NCO prepolymers are combined with the aqueous solutions of the chain-lengthening agents (d) either as a melt or in the form of solutions in solvents of the last exemplified type. According to another preferred embodiment for the production of aqueous dispersions of the products according to the present invention, the hydrophilically modified NCO-prepolymers produced from components (a), (b) and optionally (c) are mixed with at least partly blocked diamines or hydrazines in the absence of water analogously to the methods disclosed in German Offenlegungsschrift No. 2,725,589 or in U.S. Pat. Nos. 4,269,748, 4,192,937 or 4,292,226 and the thus-obtained mixture is then mixed with water. It is basically also possible simultaneously to use external emulsifiers, for example alkali metal salts of long-chain fatty acids or long-chain alkane sulphonic acids or ethoxylated alkyl benzenes having an average molecular weight of from about 300 to 3000, during the production of aqueous dispersions of the products according to the present invention, instead of or simultaneously with the incorporated hydrophilic centers. In this method, these external emulsifiers are appropriately incorporated into the NCO prepolymers before the chain-lengthening process thereof. However, the use of such external emulsifiers is a less preferred embodiment when compared to the use of incorporated hydrophilic centers. In the production of aqueous dispersions of the products according to the present process, the quantity of water is generally calculated such that dispersions containing from about 10 to 60%, preferably from about 20 to 50%, by weight solids are produced. The thus-obtained dispersions may be used with conventional auxiliaries and additives and may be used in all conventional areas for aqueous polyurethane dispersions. In all the embodiments of the present process, the chain-lengthening reaction preferably takes place at room temperature or at moderately elevated temperature, i.e., in a temperature range of from about 15° to 60° C. The invention is further illustrated, but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified. EXAMPLES The following components (a) were used in the Examples: 1. Polyester A Produced from hexane diol, neopentyl glycol and adipic acid in a mol ratio of 4.4:2.4:7.8, having a molecular weight of 1598, an acid number of 69.5 and a viscosity at 75° C. of 730 mPa.s. 2. Polyester B Produced from 1,4-butane diol, 1,6-hexane diol and adipic acid, having a molecular weight of 960, an acid number of 114.1 and a viscosity at 75° C. of 320 mPa.s. 3. Polyether A Produced from polypropylene glycol (molecular weight 2000) and succinic acid anhydride in a mol ratio of 1:2. The acid number is 50.4 and the molecular weight is 2222. 4. Polyether B Produced from polypropylene glycol (molecular weight 1000) and succinic acid anhydride in a mol ratio of 1:2. The acid number is 90 and the molecular weight is 1244. The following polyether was used as component (c): Polyether C Produced from 1 mol of monofunctional polyethylene oxide polyether started on n-butanol having a molecular weight of 1145 and 1 mol of succinic acid anhydride at 120° C. over a period of 5 hours with subsequent vacuum degassing. Content of ethylene oxide: 86.1%. EXAMPLE 1 200 g (0.13 mols) of Polyester A were dehydrated for 30 minutes at from 100° to 110° C. and under a pressure of 18 mbar in a one liter reaction vessel. After cooling to 80° C., 81.74 g (0.312 mols) of 4,4'-diisocyanatodicyclohexyl methane (Desmodur W, available from Bayer AG, Leverkusen) were added under nitrogen and the reaction vessel was immersed, with stirring, into an oil bath which had been pre-heated to 160° C. When an internal temperature of about 140° C. was reached, CO2 started to evolve vigorously. The volume of gas was measured by a gas meter. After a total of 4.5 hours, 5.82 l (0.26 mols) of CO2 had evolved, corresponding to 100% of the theoretical yield. The mixture was cooled to room temperature and a clear, highly viscous melt (η23° C.=320,000 mPa.s) was obtained containing 5.3% of NCO (calculated 5.65%). The product was readily soluble in esters, ethers and ketones. After being stored for 12 weeks at room temperature, the NCO content had fallen slightly to 5.2%. The NCO prepolymer was suitable for the production of coatings which harden under the influence of atmospheric moisture. For this purpose, the NCO prepolymer or the solution thereof is preferably mixed with a catalyst accelerating the chain-lengthening reaction with water, for example dibutyl tin dilaurate, and is applied to the substrate to be coated. EXAMPLE 2 Example 1 was repeated under identical conditions, but 0.2 g (1000 ppm) of sodium methylate were added to the reaction mixture. In this case, the theoretical volume of CO2 was obtained after 85 minutes. The NCO content amounts to 5.1% and the viscosity η25° C. was 250,000 mPa.s. Thus, the rate of the reaction was accelerated by a factor >3 by 100 ppm of sodium methylate. The product had identical solution properties and, like the product according to Example 1, is suitable for the production of coatings which are hardenable under the influence of atmospheric moisture. EXAMPLE 3 400 g (0.26 mols) of Polyester A were reacted with 152.7 g (0.583 mols) of 4,4'-diisocyanatodicyclohexylmethane (Desmodur W) in the presence of 500 ppm of sodium methylate (based on the polyester) under the reaction conditions described in Example 1. The theoretical volume of CO2 (11.6 l) had evolved after 90 minutes and the NCO content was 4.6% (calculated 5.1%). The clear, pale yellow melt was dissolved 50% in acetone. A water-dilute, clear solution was obtained which, after adding dibutyl tin dilaurate, may be used for the production of coatings which harden under the influence of atmospheric moisture. EXAMPLE 4 An NCO prepolymer which is free from urethane groups was produced in a completely analogous manner to Example 3 from the following: 200 g (0.125 mols) of Polyester A 65.5 g (0.250 mols) of 4,4'-diisocyanatodicyclohexyl methane (Desmodur W) 250 ppm of lead octoate. After 2 hours at 160° C., the mixture was dissolved 70% in dried tetrahydrofuran. NCO content: calculated 4.12%, observed 4.13% (based on solids). The clear solution was stable in storage for at least 3 months and may be used just like the solution of the previous examples for the production of coatings which harden under the influence of atmospheric moisture. EXAMPLE 5 200 g of Polyester A (0.13 mols) were reacted with 69.3 g (0.312 mols) of isophorone diisocyanate in the presence of 1000 ppm of sodium methylate in a completely analogous manner to Example 1. 100% of the theoretical yield of CO2 was produced after 90 minutes. The clear, yellowish melt was cooled (η23° C.=410,000 mPa.s) and the NCO content was determined as 4.5%. The NCO prepolymer may also be used as a binder for coating agents which harden under the influence of atmospheric moisture. EXAMPLE 6 (COMPARATIVE EXAMPLE) The following Comparative Examples 6a, 6b, and 6c demonstrate that aromatic diisocyanates are unsuitable according to the present invention due to undesirable secondary reactions. (a) 200 g of Polyester A were reacted with 51 g (0.293 mols) of 2,4-diisocyanato toluene under the reaction conditions of Example 1. After a total of 3.5 hours, only 80% of the theoretical yield (4.7 l) of CO2 was released, but the product was completely cross-linked. It was insoluble in acetone, tetrahydrofuran and ethyl acetate. (b) When this experiment was repeated in the presence of 1000 ppm of sodium methylate, the mixture cross-linked after 20 minutes, and only 67% of the theoretical yield (3.9 l) of CO2 was measured. Since catalysts did not produce the desired result, the diisocyanate was deactivated in Example 6c. (c) Comparative Example 6a was repeated, but diisocyanato toluene deactivated with 175 ppm of hydrogen chloride was used. After 2.5 hours, only 65% of the theoretical yield (3.8 l) of CO2 was obtained, and the product was already full of gel particles and was insoluble in acetone. NCO content 5.6%, calculated 5.7%. (d) Comparative Example 6a was repeated with the only exception the reaction temperature being lowered to 120° C. rather than 160° C. After 3.5 hours only 4.0 l of CO2 (71%) were released; at this point the material gelled and was insoluble in acetone. Thus the lower temperature did neither increase the evolution of CO2 nor decrease the amount of cross-linking. EXAMPLE 7 (COMPARATIVE EXAMPLE) The following Examples 7a and 7b prove the special position of cycloaliphatic diisocyanates, because they show that 1,6-diisocyanato-hexane is also unsuitable for the process according to the present invention. (a) When 800 g (0.52 mols) of Polyester A were reacted with 156.3 g (0.93 mols) of 1,6-diisocyanato-hexane, then only 70% of the theoretical yield (16 l) of CO2 was obtained after 35 minutes at from 140° to 160° C., and the product was already completely cross-linked and had become insoluble. (b) When this experiment was repeated using 200 g (0.13 mols) of Polyester A and 49.14 g (0.293 mols) of 1,6-diisocyanato-hexane in the presence of 1000 ppm of p-toluene sulphonic acid methyl ester (deactivation), a completely cross-linked product was obtained after 100 minutes, although only 74% of the theoretical yield (4.3 l) of CO2 evolved. The product was insoluble in tetrahydrofuran and in acetone. EXAMPLES 8 TO 16 The following examples show the multiplicity of possible catalysts. In each case, 200 g (0.125 mols) of dehydrated Polyester A were mixed with 62.4 g (0.28 mols) of IPDI and with the respective catalyst at about 70° C. and were lowered into a bath which had been pre-heated to 160° C. At the end of the CO2 evolution, the gas volume was measured and the viscous melt was cooled to about 80° C. and was dissolved 70% in an organic solvent. The NCO content was determined beforehand. The results are provided in Table I. TABLE I __________________________________________________________________________ % of the theoretical yield Time NCO Example Catalyst of CO.sub.2 [h] [%] 70% solution __________________________________________________________________________ 8 Sodium methylate.sup.1 100 1.0 4.6 optically clear (Acetone) 9 Sodium phenolate.sup.1 95 2.2 5.1 optically clear (Acetone) 10 Dibutyl tin dilaurate.sup.1 98 2.2 5.0 optically clear (Acetone) 11 Lithium metal.sup.2 100 2.5 5.3 optically clear (Acetone) 12 Lithium methylate.sup.1 95 1.5 4.6 optically clear (Acetone) 13 Lithium-t-butylate.sup.1 100 2.3 4.6 optically clear (Ethyl acetate) 14 Lead octoate.sup.1 99 2.2 4.9 optically clear (Tetrahydro- furan) 15 Nickel oleate.sup.1 97 1.8 4.4 optically clear (Methyl- ethyl-ketone) 16 -- 95 6.5 5.1 optically clear (Acetone) __________________________________________________________________________ .sup.1 250 ppm, based on the total mixture .sup.2 500 ppm, based on the total mixture EXAMPLES 17-18 The process was carried out in a completely analogous manner to Example 1. ______________________________________ CO.sub.2 EX- % of AM- Polyester Diiso.sup.2 theoret. NCO Time PLE A Catalyst.sup.1 cyanate yield [%] [h] ______________________________________ 17 200 g Tin-II- 73.6 g 100 4.66 1.5 octoate 18 200 g "DABCO" 73.6 g 98 4.75 1.5 ______________________________________ .sup.1 250 ppm, based on the total mixture .sup.2 4,4diisocyanatodicyclohexyl methane EXAMPLE 19 400 g (0.322 mols) of Polyether B were dehydrated and mixed with 1000 ppm of 4-methyl-2,6-di-tert.-butylphenol and 250 ppm of sodium methylate. 161 g (0.725 mols) of isophorone diisocyanate was added at 80° C. and the mixture was rapidly heated to 140° C. Vigorous CO2 evolution was observed upon reaching a temperature of 120° C. The evolution (100% of the theoretical yield) was complete after 3 hours. The NCO content was 5.4%. The product was clearly soluble in acetone and is suitable for the production of coatings which harden under the influence of atmospheric moisture. EXAMPLE 20 Example 19 was repeated, but in this case with 200 g (0.090 mols) of Polyether A and 45.1 g (0.203 mols) of isophorone diisocyanate. The CO2 evolution had finished after 1 hour at an internal temperature of 135° C. The NCO content was 3.65%. The product was clearly soluble in acetone, ethyl acetate, dioxane, tetrahydrofuran and methyethyl ketone and is suitable for the production of coatings which harden under the influence of atmospheric moisture. EXAMPLE 21 500 g of a 50% solution of an NCO prepolymer in acetone prepared according to Example 3 were diluted with a further 325 ml of acetone and were mixed at 50° C. with a mixture of 2.95 g (0.059 mols) of hydrazine hydrate and 13.5 g (0.036 mols) of a 51% aqueous solution of the sodium salt of N-aminoethyl-2,2-amino-ethane sulphonic acid in 50 g of water. After 5 minutes, the mixture was dispersed by adding dropwise 375 ml of deionized water and the acetone was distilled off under a water jet vacuum. A finely divided aqueous polyester-polyamide-polyurea dispersion was obtained which was stable in storage for more than 4 months. ______________________________________ Solids content 40.1% pH 6.8 % SO.sub.3.sup.⊖ 1.1 Particle size 303 nm (Nanometer) Outflow viscosity 11.4 sec FB, Nozzle 4. ______________________________________ A glass plate was coated with the dispersion in a wet film thickness of 0.2 mm. The coating was dried at room temperature for 8 hours and was then heated at 120° C. for 20 minutes. In this manner, an optically clear, flexible, hard-elastic film was obtained. The dispersion is particularly suitable for coating textiles or for finishing leather. EXAMPLE 22 407 g of a 50% solution of the NCO prepolymer prepared according to Example 5 were diluted with 430 ml of acetone, as described in Example 21, and then chain-lengthened with a solution of 2.6 g of hydrazine hydrate (0.051 mols) and 15.74 g (0.042 mols) of the diaminosulphonate mentioned in Example 21, in 50 ml of water. The thus-obtained solution was then dispersed in 340 g of salt-free water. After distilling off the acetone, a finely-divided aqueous dispersion of a polyester-polyurea-polyamide was obtained which was stable in storage for more than 4 months. ______________________________________ Solids content 43.5% pH 6.9 % SO.sub.3.sup.⊖ 1.3 Particle size 195 nm Outflow viscosity 12.1 sec FB, Nozzle 4. ______________________________________ The dispersion was stable to centrifugation (30 mins/3000 r.p.m.). An optically clear, highly flexible, elastic film was obtained on a glass plate which was coated with the dispersion according to Example 21, after drying in the air and after being subsequently heated at 120° C. for 20 minutes. The dispersion is suitable for coating and laminating textiles, leather or glass, for example. EXAMPLE 23 Example 3 was repeated and the clear melt was dissolved 50% in toluene/THF (in a ratio of 1:1.33). A mixture of 208.5 g of the above-mentioned prepolymer solution with 2.6 g of stearyl isocyanate was added dropwise to a solution of 10.05 g of IPDA (0.0591 mols) in 157 g of isopropanol and 94 g of toluene over a period of about 2 hours. A physically drying, optically clear, storage stable polyester-polyurea-polyamide lacquer was obtained. The solids content was 24.84% and the viscosity at 25° C. was 18,000 mPa.s The material is suitable for finishing textiles and leather. EXAMPLE 24 200 g (0.208 mols) of Polyester B were dehydrated and mixed with 103.9 g (0.468 mols) of IPDI and 250 ppm of lead octoate and were reacted for 2 hours at 160° C. bath temperature. The melt was dissolved 70% in acetone and the solution was clear and thinly liquid. The solution was stirred with a solution of 26.2 g of IPDA in 156 g of toluene and 156 g of isopropanol. The NCO content of the solution of the pre-lengthened NCO prepolymer was then 1.5%. Glass plates were then coated with the solution. After being stored for 2 days at room temperature in the air, optically clear, tough elastic films were obtained which had an excellent adhesion to glass. When, instead of IPDA, a stoichiometrically equivalent quantity of hydrazine hydrate (7.71 g) was used, clear films of a similar elasticity were obtained. 25 g of above solution (70° in acetone) was mixed with 5 g of toluene and 3 drops of catalyst Formrez®UL 1 (Witco) and coated on a clean glass plate using a 10 mil drawdown bar. After 2 days at ambient temperature a completely clear, tough and elastic moisture cured film was obtained. EXAMPLE 25 Part 1 600 g (0.407 mols) of Polyester A were dehydrated for 30 minutes at from 110° to 120° C. in a water jet vacuum. 240 g (0.916 mols) of 4,4'-diisocyanatodicyclohexyl methane (Desmodur W) were added at 80° C. and the mixture was catalyzed with 75 mg (125 ppm) of sodium methylate. The theoretical volume of CO2 (18.23 l) had evolved within 1 hour at 160° C. The prepolymer was dissolved 80% in dioxane. The NCO content of the solution was 4.06% (theoretically: 4.26%). Part 2 304 g of sulphonate diol (0.5 mols) and 100 g (1 mol) of succinic acid anhydride were mixed with 0.3 g of lithium-t-butylate and were stirred for 4 hours at from 120° to 125° C. The anhydride band had disappeared in the IR spectrum. The sulphonate diol was a propoxylated adduct of 2-butene diol-1,4 and NaHSO3 having a molecular weight of 425. The product was used as a 70% clear solution in toluene, the toluene being removed by distillation under vacuum after the reaction with the anhydride. Part 3 100 g of Polyether C (0.08 mols) were thoroughly mixed with 200 g (0.245 mols) of the product from Part 2. 188.45 g (0.7193 mols) of 4,4'-diisocyanatodicyclohexyl methane (Desmodur W) were added at 75° C. The reaction was completed (theoretical amount of CO2) after 2 hours at from 120° to 125° C. and the mixture was dissolved 80% of dioxane. The NCO content of the solution was 6.56% (theoretically: 6.54%). The ethylene oxide content of the prepolymer was 29% and the sulphonate content was 6.6%. Part 4 800 g of the prepolymer from Part 1 were thoroughly mixed with 176.6 g of the prepolymer from Part 3 at from 65° to 70° C. and were mixed with 40.9 g (0.365 mols) of acetonazine at 70° C. After 8 minutes, the mixture was dispersed with thorough stirring with a mixture of 1171 ml of water, 6.6 g of diethylene triamine and 3.8 g of ethoxylated nonylphenol ("NP 30", BAYER AG). The mixture was then stirred for 4 hours at from 60° to 70° C., cooled to room temperature and a little coarsely-divided matter was filtered off. (400μ filter). ______________________________________ Data of the dispersion ______________________________________ Solids 35% Content of ethylene oxide 3.2% Sulphonate content 0.73% pH 6.0. ______________________________________ Films were produced on glass plates and on aluminum film as described above and were dried for 5 hours at 120° C. A hard-elastic, slightly opaque film was obtained having a Shore A hardness of 71. Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims. What is claimed is: 1. A process for the production of plastics based on an isocyanate-polyaddition product which may optionally contain ionic groups with the provision that the ionic groups, if present, are exclusively sulfonate groups which comprises(1) forming an isocyanate group-containing prepolymer from(a) a compound which has a molecular weight of from 146 to about 10,000, is substantially free from hydroxyl groups, contains at least two terminal carboxyl groups and optionally contains ether and/or ester groups, (b) excess quantities of an organic nonaromatic polyisocyanate which has at least one cyclohexane ring and exclusively contains aliphatically- and/or cycloaliphatically-bound isocyanate groups and (c) up to 10 equivalent percent, based on the isocyanate-reactive groups in component (a), of a compound which is monofunctional for the purpose of the isocyanate-addition reaction and (2) reacting the product of step (1) with(d) a chain-lengthening agent comprising water, a polyamine containing at least two primary and/or secondary amino groups or hydrazine or a derivative thereof containing at least two primary and/or secondary amino groups. 2. The process of claim 1 wherein the polyisocyanate of component (1)(b) contains at least one cycloaliphatically-bound isocyanate group. 3. The process of claim 1 wherein said plastic is an aqueous dispersion of an isocyanate-polyaddition product. 4. The process of claim 3 wherein component (1)(a) comprises a compound containing ionic and/or nonionic hydrophilic groups; component (1)(c) comprises a compound containing nonionic hydrophilic groups; and/or component (2)(d) comprises a polyamine containing ionic groups, said compounds being used in a quantity which ensures the dispersibility of the polyaddition products in water. 5. The process of claim 4 wherein step (2) is conducted in the aqueous phase or step (2) is conducted in the absence of water and subsequently the polyaddition products are dispersed in water. 6. The process of claim 4 wherein component (2)(d) comprises a diprimary diamine and/or hydrazine containing at least one blocked amino group selected from the group consisting of ketimines, ketazines, oxazoladines, aldazines, aldimines and carbonates and wherein step (2) is conducted by mixing the reaction product of step (1) with component (2)(d) in the absence of water and subsequently mixing the mixture with water. 7. The process of claim 1 which comprises conducting step (1) at an equivalent ratio between isocyanate groups and isocyanate-reactive groups of from about 1.4:1 to 3:1 and at a temperature of from about 130° to 200° C. 8. The process of claim 2 which comprises conducting step (1) at an equivalent ratio between isocyanate groups and isocyanate-reactive groups of from about 1.4:1 to 3:1 and at a temperature of from about 130° to 200° C. 9. The process of claim 5 which comprises conducting step (1) at an equivalent ratio between isocyanate groups and isocyanate-reactive groups of from about 1.4:1 to 3:1 and at a temperature of from about 130° to 200° C. 10. The process of claim 6 which comprises conducting step (1) at an equivalent ratio between isocyanate groups and isocyanate-reactive groups of from about 1.4:1 to 3:1 and at a temperature of from about 130° to 200° C. 11. The product produced in accordance with the process of claim 8. 12. The product produced in accordance with the process of claim 9. 13. The product produced in accordance with the process of claim 10.

1983-07-01

en

1984-04-03

US-2732286D-A

Propstl United States Patent O METHOD OF MAKING PRINTED IMAGES Georg Prpstl, Zell am Neckar, Wurttemberg, Germany, assigner to Robert Bosch G. m. b. H., Stuttgart, Germany Application September 30, 1953, Serial No. 383,217 8 Claims. (Cl. 41-41) This application is a continuationin-part of application Serial No. 302,247, tiled August l, 1952, now abandoned. The present invention relates to a novel method of producing printed images of objects, such as type characters, printing plates or in general any proled object or surface, more particularly a method involving the production of a latent image upon a registration or copying sheet and subsequent conversion or development of the latent image into a visible image by means of a suitable developing agent. Among the objects of the invention is the provision of a method of this character which is both simple and easy to use; by which a latent image is produced by simple contact or pressure with an original to be reproduced or copied; which is adapted for either direct reproduction of an original object or for use as a master for producing additional copies by means of known reproduction processes; and which will enable the invisible or latent image to be developed into a visible image or copy expeditiously and by relatively simple means. With the foregoing and further objects in view, as will become more apparent hereafter, the invention is based essentially on the selective disintegration of an extremely thin metallic layer upon being subjected to a surface pressure by an object or original to be reproduced or printed, wherebyrto change the rate of reaction of the pressed areas with a disintegrating agentV for the metal compared with the non-pressed areas. In other words, the pressed areas of the layer form a latent image which may be converted into a visible image by subjecting the metal to a suitable disintegrating agent, such as an ammonia or bromine atmosphere, during a predetermined time period. For practical purposes, layers having a thickness of 0.02 to 2n(1/t=1/1000 of a millimeter) and consisting of finely-divided particles of zinc, cadmium, aluminum, etc., have been found to produce satisfactory results or prints of high quality and resolution. Layers of such minute thickness can be ailected or conditioned in their behavior towards a disintegrating agent of the metal by a relatively slight pressure applied thereto by the object or original to be reproduced, whereby to accelerate or decelerate, as the case may be, the rate of reaction of the pressed areas or portions compared with the non-pressed areas, upon subjecting the layer to a suitable disintegrating or developing agent. As a result of this selective disintegration lof the pressed and non-pressed areas, respectively, the latent image can be developed into a visible image or print of high contrast and definition by a proper control of the developing time. In a simple embodiment of the invention, contact of the metallized layer applied to a suitable base, such as a sheet of paper, polystyrene, or the like, with a printing plate or the type characters of a conventional typewriter', under sucient pressure, elects a change in the structure of the pressed areas to result in a latent image which can' be converted into' a visible image in the manner pointed out. In applying the pressure tc the merallized surface it is advisable to interpose a protective sheet, such as= of thi-n ICC paper or the like, to prevent contaminating matter from being applied to the metal surface and interfering with the latent image formation by pressure application to the layer. In the same manner, fingerprints or prints of other rough or proled surfaces can be produced by merely pressing the linger against a sheet of metallized paper through a thin sheet of protective paper or the like. T he fact that a relatively slight pressure applied to the metallized layer is sutcient to enable the production of prints or copies of high contrast and resolution, in predicated basically upon the minute thickness and structure of the metallized layer. More particularly, with metallized layers of this type and minute thickness, i. e.A with the metal applied in highly dispersed or nely-divided condition, such as obtained by a cathode disintegration or evaporation process in a vacuum, the behavior of the entire layer or metal body is dependent to a predominating degree upon the surface condition of the layer, much more so than in the case of a solid metal body or layer. Moreover, purely geometric reasons play an important part in the formation of a well-defined image or print, as will become evident from the following. The development or disintegration of the metallized layer, in particular in thet case of a chemical developer, such as a bromine or ammonia atmosphere, constitutes a gradually advancing process, starting at an initial point or development center. For the purpose of the present discussion, it may be assumed that the reaction once started at the surface progresses at approximately equal speed both tangentially as Well as transversely to the metallized layer. lf the reaction is interrupted at the instant of reaching the opposite or inner side of the layer, it is understood that the developed image diiters from the effective latent image merely by an amount equal to or of the order of the thickness of the metallized layer. From this it follows that the developed image or print equals the latent image or object to be reproduced to an increasingly greater degree the smaller the thickness of the metal layer. For this reason layers having a thickness within or below the range mentioned above not only allord the required modification or changes in the structure of the metal by the applied activating pressure, but also result in a developed image or print,- upon subjecting the layer to a disintegration. process, having a high degree of contrast and definition. The invention will be better understood by the following detailed description taken in reference to the accompanying drawing forming part of this specification and wherein: Fig'. l shows on a greatly enlarged scale a portion of a metallized printing sheet having an elemental` latent image formed thereon by pressure from an object or original to be reproduced; and Figs. 2l to 5 show various images obtainable by the development of the latent image of Fig. l using different developers and/ or metallized layers. Referring more particularly to Fig. 1, the numeral I0 represents a support or recording sheet consisting, for instance, of lacquered paper, polystyrene or other suitable Iight-pervious material, and having coated thereon a coherent layer l1 of finely-divided or highly-dispersed metal particles' consisting of the group of zinc, cadmium and aluminum, etc. and being preferably produced by a cathode disintegration or evaporation process in a vacuum. The numeral 12 indicates an activated or pressed elemental area upon or within the layer l1, representing a latent image or an object or original to be printed or reproduced. By subjecting the sheet with its latent image to an atmosphere of ammonia or brornine or another developer or disintegrating agent for the metal, the disintegration will be accelerated or decelerated for the' pressed area or latent image 12, in such a manner 3 as to rcsult in a copy or print of the original subject matter, provided a proper timing or interruption of the development at the instant when the reaction has progressed from the outer to the inner surface of the layer 11. Such a developed image is shown for example by Fig. 2. In the foregoing example, the effect of the latent image 12 may be manifested in a slowing down or deceleration of the disintegration at the pressed areas compared with the non-pressed areas, such a pressure activation being more appropriately termed a negative activation or passivation, as compared with a positive activation resulting in an accelerated reaction or disintegration at the pressed areas during development. As an example, when using a metallized zinc layer in connection with bromine vapor as a developer, the activating pressure results in an accelerated disintegration of the metal at the pressed or latent image areas (positive activation), while in the case of an acetic acid atmosphere used as a developing agent for the same metal layer, the applied pressure causes a slowing down of the rate of disintegration of the metal at the pressed areas (passivation or negative activation). In practice, the effective latent image area b may differ from the actual latent image a, conforming to the object or original to be reproduced, by a slight amount c representing an initial active zone and being either positive, as in Figs. 2 and 3, or negative, as in Figs. 4 and 5, the former having the effect of increasing and the latter of decreasing the effective latent image area b compared with the actual latent image a. Furthermore, the reaction at the point of transition from the activated to the non-activated areas, for reasons of continuity, changes gradually from zero to a maximum, thus creating additional developing zon'es beyond the boundaries of the effective latent image. The result will be a nal developed image having an area d as shown in the drawing. In the drawing, the additional active area c and developing zone have been shown greatly exaggerated for the purpose of better illustration. Both effects are greatly minimized Or rendered negligible for all practical purposes by using metallized layers having a thickness within the order given hereinabove. The difference between the actual and effective latent image or the initial active zone c may be due to an interaction between the pressure applying body with the metal, producing additional active zones adjacent to the actually pressed areas, in the case of a positive initial active zone, as shown by Figs. 2 and 3, or causing a partial neutralization of the edge zone of the pressed or activated area, in the case of a negative initial active zone, as shown by Figs. 4 and 5. Figs. 2 and 3 show the developed image d assuming activation or passivation, respectively, of the layer 11 and a positive initial active zone c, while Figs. 4 and 5 illustrate the developed image for both activation and passivation, respectively, in case of a negative initial active zone at the start of the developing process. The pressure activation or passivation of a metallized layer according to the present invention may be effected either by the use of static or dynamic pressure, that is, by simply pressing the body or original to be reproduced upon the layer or by moving a recording element over the layer with sufiicient surface pressure (stroke activay tion). The minimum pressure required to produce a developable latent image may vary widely, depending upon existing conditions. When using zinc as a metallized coating, pressures of between 0.l to l() kg. per cm.2 have been found to give satisfactory results. The optimum pressure for other metals and developer combinations is, however, best determined by experiment. Although the actual phenomena taking place in formation and development of the latent image are not as yet fully understood, experience and experiments have shown that the following effects or a combination thereof provide a reasonable explanation of the formation and development of the latent image according to the invention. It may be assumed that the metallized layer is normally covered with a thin covering layer of oxide or another substance, said covering layer being broken up or destroyed by the applied pressure, whereby during the subsequent disintegration the metal is attacked both directly and indirectly so as to result in a selective development or formation of a visible image. The covering layer upon the metallized layer may also be completely torn off and transferred to the pressing body or object at the instant of interrupting the contact, thus again providing areas of different surface conditions and subject to a different rate of attack by the developer or disintegrating agent. Furthermore, it is possible that parts of the metallized layer become recrystallized as a result of the applied pressure 0r the metallic crystals become crushed or broken up into smaller units by plastic deformation so as to produce starting or developing centers for the subsequent disintegration reaction. Internal stresses and/ or faults produced as a result of the applied pressure may also play an important part in producing differently reacting areas forming the latent image as a result of the activating pressure application. In other words, the above and similar effects all cause an inhomogeneity in the pressed portions of the metallized layer compared with the non-pressed portions, in such a manner as to result in a selective preconditioning or varying rate of reaction with the disintegrating or developing agent. As pointed out hereinbefore, maximum sharpness or definition is obtained by interrupting the development at the instant when the reaction has traversed or progressed to the inner side of the layer, without having materially affected the activated or pressed areas, constituting the latent image, assuming a negative activation or passivation of the pressed areas by the applied pressure. The development may be interrupted by subjecting the layer to a suitable neutralizing or stop bath, while the remaining metallized areas forming the developed image may be protected against further disintegration, such as by the surrounding atmosphere, by the application thereto of a thin chemically neutral coating, such as a coating of polystyrene lacquer or an equivalent material. The print or reproduction obtained in this manner may in turn serve as a master for making further contact prints or enlargements by the aid of any of the known photographic, blueprint, diazo or similar reproduction processes. Since metals and their reaction products exhibit substantial differences in optical reflectivity and absorption, suiciently contrasting images or prints can be produced by the method according to the invention by means of metallized layers having a thickness within and below the range mentioned. The resolution of the developed image is further dependent upon the crystal or grain size of the metal in addition to the thickness of the layer. However, the condition of the base material may also play an important part. For normal reproduction or macroscopic prints, ordinary or lacquered paper has been found to give satisfactory results, while for microscopic registrations or prints, a highly smooth base is required, such as glass, synthetic or equivalent material. As will be understood, the invention is not limited to the production of photographic, blueprint or like copies using the metallized print as an original, either positive or negative, i. e. with the base of the metallized layer consisting of light pervious, such as translucent or transparent material, and with the metal particles forming a relatively opaque layer. Thus, a metallized image may be produced in accordance with the invention upon a rigid printing plate, coated with a metallized layer in substantially the same manner as described hereinbefore. The plate serves in turn as a matrix for printing a number of copies by the use of a suitable die or pigment selectivelyfadhering: to either theV metallized or demetallized areas upon said plate. '-Alternatively, use of a suitable base material makesv it possible to selectively etch away the non-metallic or demetallized portions of the plate in an effort to produce a normal printing plate having raised metallized portions. The latter may then in' turn be demetallized by'subjecting the plate to a disintegrating agent, in order to obtain an ordinary printing platesuitable for use in connection with standard printing applications. n Such a printing plate produced either according to the invention or otherwise may also serve as a means for activating the original. metallized area, if; a large number of metallized prints or copies are desired. For this purpose, the printing plate or matrix is simply pressed against the metallized layer, preferablywith the interposition of a thin protective sheet to prevent the transfer onto the metallized layer of any foreign contaminating substance. The thus obtained pressure activated metallized layer carrying a latent image of the subject matter delineated upon the printing plate is then developed to produce a visible image in the manner according to the invention and described hereinbefore. A variety of gaseous or liquid materials have been found suitable as disintegrating or developing agents for use in connection with the present invention, a few preferred examples being described in the following. Good results are obtained both with bromine fumes having admixed therewith a suitable ballast gas, such as air or vapors of the solvents of bromine. This developer is especially useful in connection with metallized zinc layers. Other halogen vapors have been found to have a similar effect. Other satisfactory gaseous developers are ammonia-air mixtures containing suitable amounts of moisture, or glacial acetic acid vapor including air and moisture. The foregoing are examples of 'gaseous developers, while the following are suitable developers in liquid form, tested and found to give satisfactory results: Concentrated sulfuric acid, being especially suitable for dynamic pressure activation of aluminum layers; bromine and other halogens dissolved in various organic solvents, especially suitable for use with zinc, suitable solvents having been found in the form of chloroform, carbon tetrachloride, various ethers, alcohols, benzol, acetone, etc. In the foregoing the invention has been described with specific reference to a few illustrative methods and processes. It will be evident, however, that modifications and variations, as well as the substitution of equivalentesteps and processes for those described herein for illustration, may be made without departing from the broader scope and spirit of the invention as set forth in the appended claims. In general, the process of the invention may be used for the production of prints, images, records, registrations, etc. of any object, proled or roughened surface or `moving member adapted to exert an activating or passivating pressure, either static or dynamic (stroke activation) upon a metallized surface, including typing, printing, production of fingerprints or prints of any roughened surface to be investigated, recording by a moving pen or stylus, and the like. The specification and drawing are accordingly to be regarded in an illustrative rather than in a limiting sense. What is claimed is: l. A recording method comprising the steps of providing a base member having deposited thereon a coherent layer consisting of highly-dispersed metallic particles and having a thickness of from 0.005 to 2n, applying to selected areas of said layer conforming to the outline of a record to be produced a pressure to affect therate ot' reaction of the layer metal with a disintegrating agent, to thereby form a latent image of said record, and subjecting said layer to a disintegrating agent during a predetermined time period, to cause a differential disintegration, at the activated an'd riorra'ctivated areas, respectively, of the layer metal, whereby to convert said latent image intoa visible image upon said member. -2. A recording method comprising the steps of proi viding a base member having deposited thereon a coherent layer consisting of highly-dispersed metallic particles of the group consisting of zinc, cadmium and aluminum and having a thickness of from 0.005 to 2n, applying toV selected areas .of said layer conforming to the outline of a record' to be produced a pressure to affect the rate of reaction of the layer metal with a disintegrating agent, to thereby forma latent image of said record, and subjecting said layer to a disintegrating agent during a predetermined timeperiod, to cause a differential. disintegration at the activated land nonactivated areas, respectively, of the layer metal, whereby to convert said latent-imageY into a visable image upon said member. 3. A recording method comprising the steps of providing a base member having deposited thereon a coherent layer consisting of highly-dispersed zinc particles and having a thickness of from 0.005 to 2p., applying to selected areas of said layer conforming to the outline of a record to be produced a pressure to affect the rate of reaction of the layer metal with a disintegrating agent, to thereby form a latent image of said record, and subjecting said layer to a disintegrating agent of the group consisting of halogen, ammonia and acetic acid vapors during a predetermined time period, to cause a differential disintegration at the activated and non-activated areas, respectively, of the layer metal, whereby to convert said latent image into a visible image upon said member. 4. A recording method comprising the steps of providing a base member having deposited thereon a coherent layer consisting of highly-dispersed metallic alumimum particles having a thickness of from 0.005 to 2u, applying to selected areas of said layer conforming to the outline of the record to be produced a pressure to affect the rate of reaction of the layer metal with a disintegrating agent, to thereby form a latent image of said record, and subjecting said layer to sulphuric acid during a predetermined time period, to cause a differential disintegration at the activated and non-activated areas, respectively, of the layer metal, whereby to convert said latent image into a visible image upon said member. 5. A recording method comprising the steps of providinga base member having deposited thereon a coherent layer consisting of highly-dispersed metallic zinc particles and having a thickness of from 0.005 to 2p., applying to selected areas of said layer conforming to the outline of the record to be produced a pressure to affect the rate of reaction of the layer metal with a disintegrating agent, to thereby form a latent image of said record, and subjecting said layer to a disintegrating agent comprising halogen dissolved in an organic solvent during a predetermined time period, to cause a differential disintegration at the activated and non-activated areas, respectively, of the layer metal, whereby to convert said latent image into a visible image upon said member. 6. A recording method comprising providing a base member having deposited thereon a coherent layer consisting of highly-dispersed zinc particles and having a thickness of from 0.005 to 2n, applying to selected areas of said layer conforming to the outline of a record to be produced a pressure to alfect the rate of reaction of the layer metal with a disintegrating agent, to thereby form a latent image of said record, and subjecting said layer to an atmosphere containing bromine during a predetermined time period, to cause a differential disintegration at the activated and non-activated areas, respectively, of the layer metal, whereby to convert said latent image into a visible image upon said member. 7. A recording method comprising the steps of providing a base member having deposited thereon a coherent layer consisting of highly-dispersed zinc particles having a thickness of from 0.005 to 2n, applying to selected areas of said layer conforming to the outline of a record to be produced a pressure to affect the rate of reaction of the layer metal with a disintegrating agent, to thereby form a latent image of said record, and subjecting said layer to an atmosphere containing ammonia during a predetermined time period, to cause a differential disintegration at the activated and non-activated areas, respectively, of the layer metal, whereby to convert said latent image into a visible image upon said member. 8. A recording method comprising the steps of providing a light-pervious base member having deposited thereon a coherent layer consisting of highly-dispersed metallic particles having a thickness of from 0.005 to 2p., applying to selected areas of said layer conforming to the outline of a record to be produced a pressure to affect the rate of reaction of the layer metal with a disintegrating .28 agent, to thereby form a latent image of said record, and subjecting said layer to a disintegratingagent of the layer metal during la limited time period, to cause a differential disintegration at the activatedl and non-activated areas, respectively, of the layer metal such as to substantially remove the metal at one of said last-mentioned areas, whereby to convert said latent image into a visible image upon said member. References Cited in the le of this patent UNITED STATES PATENTS 1. A RECORDING METHOD COMPRISING THE STEPS OF PROVIDING A BASE MEMBER HAVING DEPOSITED THEREON A COHERENT LAYER CONSISTING OF HIGHLY-DISPERSED METALLIC PARTICLES AND HAVING A THICKNESS OF FROM 0.005 TO 2U, APPLYING TO SELECTED AREAS OF SAID LAYER CONFORMING TO THE OUTLINE OF A RECORD TO BE PRODUCED A PRESSURE TO AFFECT THE RATE OF REACTION OF THE LAYER METAL WITH A DISINTEGRATING AGENT, TO THEREBY FORM A LATENT IMAGE OF SAID RECORD, AND SUBJECTING SAID LAYER TO A DISINTEGRATING AGENT DURING A PREDETERMINED TIME PERIOD, TO CAUSE A DIFFERENTIAL DISINTEGRATION AT THE ACTIVATED AND NON-ACTIVATED AREAS, RESPECTIVELY, OF THE LAYER METAL, WHEREBY TO CONVERT SAID LATENT IMAGE INTO A VISIBLE IMAGE UPON SAID MEMBER.

en

1956-01-24

US-14233761-A

Power transmission Sept. 28, 1965 G. P. BUTTERBAUGH ET AL 3,2@8305 POWER TRANSMISSION Filed Oct. 2, 1961 5 Sheets-Sheet 1 BY THE/R ATI'QQ S. 9921s Em/ p 195 G. P. BUTTERBAUGH ET AL 3,20&30 POWER TRANSMISS ION 3 Sheets-Sheet 2 Filed Oct. 2, 1961 MM QM 3,2083% PUWER TRANSMISSION Galen P. Butterhaugh, Lynwood, and Esley F. Salshury, Los Angeles, (Zaiif, assignors, by mesne assignments, to Clarence E. Fleming, .llr., and Clifiord R. Anderson, in, both of Pasadena, Calif. Filed Oct. 2, 1961, Ser. No. 142,337 3 Claims. (Q1. 74-694) This invention relates to power transmission mechamsrns. The power transmission mechanism of the invention is primarily intended for use on golf carts, personnel carriers, garden tractors, and similar vehicles which are powered by small horsepower gasoline engines, usually in the range of five to ten horsepower. There is a decided need for a dependable transmission mechanism for this type of service. The transmission mechanism of the invention is particularly suitable for transmitting power from the driven pulley of an automatic variable speed torque converter of the general type illustrated and described in U.S. Patent No. 2,543,337, Salsbury, to the drive wheels of a vehicle. It is an object of the invention to provide a differential of the type having a worm and a worm gear characterized by an improved structure which permits the ready replacement of the input shaft to the worm without disturbing the worm in its relation to the Worm gear and to its mounting. A further object of the invention is to provide a novel design of differential worms .and input shaft which forestalls any distortion of the differential input shaft, resulting from overhung load or other reason, from being tranmitted to the worm itself. In one embodiment of the power transmission mechanism of the invention there is employed a differential and manually shiftable transmission assembly, the differential having a worm associated with a worm gear and the transmission being provided with a shiftable gear that is movable between reverse and forward positions. There is provided a common shaft coupling the differential and power transmission together, which common shaft serves the dual role of output shaft to the transmission and input shaft to the differential. The shiftable gear of the transmission is slidably carried by the common shaft and is movable lengthwise thereof between its reverse and forward positions and the worm of the differential is mounted upon the common shaft within the differential. The common shaft may be removed from the worm and differential housing Without disturbing the worm in its relation to the worm gear. The transmission preferably has a transmission input shaft which is in alignment with the common shaft, with the transmission end of the transmission input shaft being provided with a counterbore having a bearing which rotatably supports the transmission end of the common shaft when the transmission is in its reverse position. When the foregoing shiftable gear is moved into the transmission forward position, it serves to lock the common shaft to the transmission input shaft providing a direct drive. In a preferred embodiment of the mechanism of the invention, the differential worm, which is tubular, is rotatably supported in bearings at its opposite ends within the differential housing. The worm along at least a portion of its length has internal grooves. The differential input shaft which extends through the worm is provided with external splines which seat in the internal grooves Patented Sept. 28, 1965 of the tubular worm. With this arrangement the differential input shaft may be removed from the worm and from the differential housing without disturbing the worm in its relation to the worm gear. The differential input shaft at one end of the tubular worm has a locking means, preferably a nut on the threaded end of the shaft, which engages that end of the worm to forestall removal of the shaft. The shaft at the other end of the tubular worm has an enlarged portion, preferably with a sloping surface that engages the opposite end of the worm gear. The differential shaft may be removed from the tubular worm by disengaging the locking means and withdrawing the shaft from the opposite end of the worm. In a preferred embodiment of the differential component of the power transmission mechanism of the invention, the splines of the input shaft which seat in the grooves of the internal wall of the tubular worm are immediately adjacent the locking means. The splines of the input shaft normally need not extend more than one-quarter of the length of the portion of the shaft contained within the tubular worm. These and other advantages and objects of the power transmission of the invention will become more apparent from the following specification and the accompanying drawings which are for the purpose of illustration only, and in which: FIG. 1 is a side elevational view of a preferred form of the power transmission train of the invention made up of a variable speed drive, with a driven pulley of the drive on an input shaft of a manually shiftable transmission which is coupled to a differential; FIG. 2 is a longitudinal sectional view of the power transmission train of FIG. 1 with a gear being substituted for the driven pulley of the variable speed drive on the input shaft to the transmission; FIG. 3 is a cross-sectional view talren along line 3-3 of FIG. 2 through the differential component of the power transmission train of FIG. 2; FIG. 4 is a fragmentary sectional view taken along line 44 of FIG. 2 illustrating a detent mechanism of the manually shiftaole transmission component; and FIG. 5 is a fragmentary sectional view taken along line 5-5 of FIG. 2 through one of the gears of the transmission component. With reference to FIGS. 1 and 2, there is illustrated a power transmission train made up of a variable speed drive 12 with a driven pulley 1 (FIG. 1 only) of the drive 12 mounted on an input shaft 16 of a manually shiftable transmission 18 which is coupled by a common shaft Ztl to a tubular worm 22 of a differential 24. The common shaft Ztl serves in a dual role as output shaft to the transmission 18 and input shaft to the differential 24. It will be seen that in FIG. 2 a gear 26 has been substituted for the driven pulley 14 of FIG. 1. This illustrates one of the many combinations readily available by interchange of components of the power transmission device of the invention. In the device illustrated in FIGS. l and 2 the outer end of the transmission input shaft 16 is supported by an outboard bearing 30 of a bracket 32 which is bolted to the housing of the transmission 18. The bracket 32 has an inverted L-shape with an elongated base member 34 which is horizontally disposed and held by bolts 36 and 38 respectively to legs 4i and 4?. extending downwardly from the underside of the transmission housing. A vertically disposed arm 44 of the bracket 32 is bolted to the outer end of the base member 34 and carries at its upper end the aforementioned outboard bearing 30. In the particular embodiment illustrated the outboard bearing is of the ball bearing type and is enclosed in a retainer 31 that is bolted to a horizontal extension at the upper end of the vertical arm 44 of the bracket 32. A spacer 33 encircles the shaft 16 and is positioned between the inner race 35 of the outboard bearing 31} and shoulder 37 of the shaft 16. The inner end of the transmission input shaft 16 is supported within the housing of the transmission by a ball bearing assembly 48. The inner end of the transmission shaft 16 is counterbored to receive a sleeve bearing 5%. A gear 52 having two sets of external teeth 54 and 55 is press-fitted to the outer circumference of the transmission shaft adjacent its inner end. The transmission shaft 16 extends into the interior of the transmission 18 through an oversized hole 57 of a bell shaped enclosure plate 56. A dust seal ring 58 snugly engages the circumerence of the shaft 16 within the enclosure plate 56. The dust seal ring 58 is of the type having a wire spring member 611 which urges the seal proper into close contact with the encircled shaft 16. The common shaft 20 at its transmission end has a short length of reduced diameter, which portion is rotatably supported by the sleeve bearing 51) contained within the counterbore of the transmission input shaft 16. A shiftable or sliding gear 62 encircles the transmission end of the common shaft 211 (immediately adjacent the transmission input shaft 16) and is movable therealong. The sliding gear 62 at one end has external teeth 66 and at its other end is provided with smaller internal teeth 63. The sliding gear 62 has three positions, namely reverse, neutral, and forward. The sliding gear 62 centrally of its length has an outwardly facing groove 76 in which 7 a shifting yoke 72 is disposed. The yoke 72 is carried by a shifting rod 74. The shifting rod '74 parallels the shafts 16 and 20 and is supported in an upper portion of the transmission housing. The rod 74 adjacent its inner end is provided with three spaced grooves 76a, 76b, and 760 which co-operate individually with a steel ball '78 (see FIGS. 2 and 4) to hold the shifting rod '74 and yoke '72 in one of the three transmission positions. The ball 78 is urged towards the rod 74 by a coil spring 80. Each of the grooves 76a, 76b, and 760 is relatively shallow, thus permitting movement of the rod 72 with the application of some force. When the sliding gear 62 is moved to the right of FIG. 2 to the transmissions forward position, its internal teeth 63 mesh with the teeth 55 of gear 52, providing a direct drive between the transmission input shaft 16 and the common shaft 20. It will be appreciated that the sliding gear 62 is slidably held to the common shaft by splines 34-. The sliding gear 62 is illustrated in FIG. 2 in its neutral position. When sliding gear 62 is moved to the left of FIG. 2 to the transmissions reverse position, its external teeth 66 engage the teeth of an idler gear 33 which idler gear 8% meshes with teeth 90 of a spool gear 92. The spool gear 92 is carried by a shaft 94 that is spaced below and parallels the two shafts 16 and 29. The idler gear 88 is carried by a stud shaft 96 (FIG. 5) that similarly parallels the two shafts 16 and 20. The opposite end of the spool gear 92 carries teeth 93 which are in mesh with external teeth 54 of the gear 52 which, it will be recalled, is carried by the inner end of the transmission input shaft 16. When the sliding gear 62 is in the transmissions reverse position, power is transmitted via the transmission input shaft 16, the spool gear 92, and the idler gear 83 to the common shaft 20 which is rotated in a direction counter to that of the direct drive of the forward position. The tubular worm 22 of the differential 2 is supported at its opposite ends within the differential housing by roller bearing assemblies 106 and 102. The common shaft at its differential end is threaded to receive a nut 4, 1116. The nut 11% in its threaded-down position abuts one end of the tubular worm 22. Access to the nut 106 is gained by removal of an end plate 107 of the differential housing. The common shaft 20 at the other end of the worm 22 has an enlarged portion 116 which has a sloping surafce 112 that engages the end of the worm. It is thus seen that the common shaft 211 is supported and held in alignment by the sleeve bearing 56 within the counterbore of the inner end of the transmission input shaft 16 and is secured in the worm 22 of the differential 24 by the nut 106 and the enlarged portion 110. Torque is transmitted to the worm 22 through splines 114 on the differential end of the shaft 20, the splines 114 seating in internal grooves of the inner Wall of the tubular worm 22. The splines 114 of the input shaft in the embodiment illustrated extend less than one-quarter of the length of the shaft Within the tubular worm 22. Threads 116 of the tubular worm 22 engage with circumferential teeth 118 of a worm gear 120. The worm gear 126 (see FIGS. 2 and 3) carries four planet pinions 122, 124, 126 and 128 which are respectively rotatably held to the worm gear 121 by stub shafts 122a, 124a, 126a, 123a. The two planet pinions 122 and 124 cooperate to drive a sun gear which is affixed to a right-hand axle 132. Similarly, the two planet pinions 126 and 128 co-operate to drive a second sun gear 134 which is aflixed to a left-hand axle 136. The two axles 132 and 136 which are in axial alignment, have a common pin 138 seated in adjoining counterbores of their abutting ends. The axles 132 and 136 are respectively supported within the differential housing by roller bearings 1 10 and 142. Dust seals 148 and 150 respectively encircle the axles 132 and 136. The design of the components of the power transmission mechanism of the invention permits joining of the components in various combinations. This feature is a decided advantage as it permits the manufacturer to market a number of power transmission trains capable of various duties with a minimum of component parts. The differential housing is provided with a fill plug 121 and a drain plug 123. Grease may pass between the differential 24 and transmission 18 through aligned holes 125 and 127 in the abutting walls of the two units. The holes 125 and 127 are filled with suitable plugs when the units are used separately. Although exemplary embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that various changes, modifications, and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims which follow. \Ve claim: 1. In a differential of the type having a worm and a worm gear contained in a housing, the improvement comprising: a tubular worm rotatably supported in bearings at its opposite ends within the housing, said worm along at least a portion of its length having longitudinallyextending internal grooves; a differential input shaft extending through the worm with external splines on the input shaft seating in the internal groopes in the tubular worm, said differential input shaft being removable from the worm and differential without disturbing the worm in its relation to the worm gear; and said input shaft at one end of the tubular worm having a locking means engaging said one end of the worm to forestall removal of the shaft, and said shaft at the opposite end of the tubular worm having an enlarged portion that engages said opposite end of the worm, said shaft being removable from said opposite end of the tubular worm upon disengaging said locking means. 2. A differential comprising: a housing; a tubular worm rotatably supported in bearings at its the splines of the input shaft are immediately adjacent opposite ends within the housing, said form along the locking means and said splines extend less than oneat least a portion of its length having longitudinallyquarter of the length of the shaft Within the tubular Worm. extending internal grooves; a differential input shaft extending through the Worm 5 References Clted by the Examiner With external splines on the input shaft seating in the UNITED STATES PATENTS internal grooves of the tubular Worm, said differen- 1 175 251 3/16 Fleury et a1 74 70O tial input shaft at its outer end being unsupported 1:207246 12/16 Vining a cantilever design; and 13421861 6/20 Morton 74 713 said input shaft at one end of the tubular worm having 10 1 381 197 6/21 John 74, 377 a locking means engaging said one end of the Worm 7 /29 Smith to forestall IBmOVEIl 0f the shaft, and said shaft at 1 7703 4 7 30 Lancia 713 the opposite end of the tubular worm having an enlarged portion that engages said opposite end of FOREIGN PATENTS the worm, said shaft being removable from said 15 651,603 4/51 Great Britain. opposite end of the tubular worm upon disengaging I said 10 cking means- DON A. WAITE, Prlmary Examiner. 3. A differential in accordance With claim 1 wherein BROUGHTON G. DURHAM, Examiner. 1. IN A DIFFERENTIAL OF THE TYPE HAVING A WORM AND A WORM GEAR CONTAINED IN A HOUSING, THE IMPROVEMENT COMPRISING; A TUBULAR WORM ROTATABLY SUPPORTED IN BEARING AT ITS OPPOSITE ENDS WITHIN THE HOUSING, SAID WORM ALONG AT LEAST A PORTION OF ITS LENGTH HAVING LONGITUDINALLYEXTENDING INTERNAL GROOVES; A DIFFERENTIAL INPUT SHAFT EXTENDING THROUGH THE WORM WITH EXTERNAL SPLINES ON THE INPUT SHAFT SEATING IN THE INTERNAL GROOPES IN THE TUBULAR WORM, SAID DIFFERENTIAL INPUT SHAFT BEING REMOVABLE FROM THE WORM AND DIFFERENTIAL WITHOUT DISTURBING THE WORM IN IS RELATION TO THE WORM GEAR; AND SAID INPUT SHAFT AT ONE END OF THE TUBULAR WORM HAVING A LOCKING MEANS ENGAGING SAID ONE END OF THE WORM TO FORESTALL REMOVAL OF THE SHAFT, AND SAID SHAFT AT THE OPPOSITE END OF THE TUBULAR WORM HAVING AN ENLARGED PORTION THAT ENGAGES SAID OPPOSITE END OF THE WORM, SAID SHAFT BEING REMOVABLE FROM SAID OPPOSITE END OF THE TUBULAR WORM UPON DISENGAGING SAID LOCKING MEANS.

1961-10-02

en

1965-09-28

US-21881198-A

System and method for bypassing supervisory memory intervention for data transfers between devices having local memories ABSTRACT A system and method for providing direct transfers of data segments between devices having local memories without the need for first transferring the data to a central supervisory memory to maintain cache coherency. Direct data transfers are performed from a first local memory of a first device to a second local memory in a second device in a transaction processing system that includes a main memory to provide supervisory storage capability for the transaction processing system, and a directory storage for maintaining ownership status of each data segment of the main memory. A data transfer of a requested data segment is requested by the second device to obtain the requested data segment stored in the first local memory of the first device. The requested data segment is removed from the first local memory in response to the data transfer request, and is directly transferred to the second local memory of the second device. The requested data segment is also transferred to the main memory, and to the directory storage where the ownership status can be revised to reflect a change of ownership from the first device to the second device. The direct transfer of the requested data segment between the first and second devices occurs independently of the transfer of the requested data segment from the first device to the main memory and directory storage. CROSS-REFERENCE TO OTHER PATENT APPLICATIONS The following co-pending patent application of common assignee contains some common disclosure: "Bi-directional Interface Distributed Control Mechanism", filed Jun. 12, 1998, Ser. No. 09/096,624, which is incorporated herein by reference in its entirety; "Queueing Architecture And Control System For Data Processing System Having Independently-Operative Data And Address Interfaces", filed Jun. 12, 1998, Ser. No. 09/096,822, which is incorporated herein by reference in its entirety; "High-Performance Modular Memory System With Cross bar Connections"; filed Dec. 31, 1997, Ser. No. 09/001,592, which is incorporated herein by reference in its entirety; and "Directory Based Cache Coherency System Supporting Multiple Instruction Processor and Input/Output Caches"; filed Dec. 31, 1997, Ser. No. 09/001,598, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION This invention relates generally to cache coherency schemes for use in multiprocessing, shared memory systems, and more particularly to a system and method for providing direct data transfers between modules having local memories, thereby selectively bypassing the need to route data through a centralized memory while maintaining complete cache coherency at the centralized memory. BACKGROUND OF THE INVENTION Large-scale data processing systems typically utilize a tremendous amount of memory. This is particularly true in multiprocessing systems where multiple processing units and numerous input/output modules are implemented. There are several memory methodologies known in the art that provide for efficient use of memory in such multiprocessing environments. One such memory methodology is a distributed memory where each processor has access to its own dedicated memory, and access to another processor's memory involves sending messages via an inter-processor network. While distributed memory structures avoid problems of contention for memory and can be implemented relatively inexpensively, it is usually slower than other memory methodologies, such as shared memory systems. Shared memory is used in a parallel or multiprocessing system, and can be accessed by more than one processor. The shared memory is connected to the multiple processing units--typically accomplished using a shared bus or network. Large-scale shared memories may be designed to cooperate with local cache memories associated with each processor in the system. Cache consistency protocols, or coherency protocols, ensure that one processor's locally-stored copy of a shared memory location is invalidated when another processor writes to that shared memory location. More particularly, when multiple cache memories are coupled to a single main memory for the purpose of temporarily storing data signals, some system must be utilized to ensure that all processors, such as instruction processors (IPs) are working from the same (most recent) copy of the data. For example, if a copy of a data item is stored, and subsequently modified in a cache memory, another IP requesting access to the same data item must be prevented from using the older copy of the data item stored either in main memory or the requesting IP's cache. This is referred to as maintaining cache coherency. Maintaining cache coherency becomes more difficult as more caches are added to the system since more copies of a single data item may have to be tracked. Many methods exist to maintain cache coherency. Some earlier systems achieve coherency by implementing memory locks. That is, if an updated copy of data existed within a local cache, other processors were prohibited from obtaining a copy of the data from main memory until the updated copy was returned to main memory, thereby releasing the lock. For complex systems, the additional hardware and/or operating time required for setting and releasing the locks within main memory cannot be justified. Furthermore, reliance on such locks directly prohibits certain types of applications such as parallel processing. Other manners of maintaining cache coherency exist, such as memory bus "snooping", and other techniques. For distributed systems having hierarchical memory structures, a directory-based coherency system becomes more practical. Directory-based coherency systems utilize a centralized directory to record the location and the status of data as it exists throughout the system. For example, the directory records which caches have a copy of the data, and further records if any of the caches have an updated copy of the data. When a cache makes a request to main memory for a data item, the central directory is consulted to determine where the most recent copy of that data item resides. Based on this information, the most recent copy of the data is retrieved so it may be provided to the requesting cache. The central directory is then updated to reflect the new status for that unit of memory. However, due to the ever-increasing number of processing devices and I/O modules capable of being configured within a single system, it has become quite common for one processing module or I/O module to request data that is currently "owned" by another processing or I/O module. Typically, such a request involves a first request by a central supervisory memory to have the data and ownership returned to that central memory, such as a main computer memory. The current owner of the valid data then transfers both the current data and ownership back to the central memory which must then provide the data to the requesting processing or I/O module in a conventional manner. While such a system facilitates cache coherency maintenance, it results in unnecessary latencies, particularly where there are a large number of potential local or cache memories external to the main memory. It would therefore be desirable to provide a system and method for directly transferring locally-stored data, such as cached data, between requesters while maintaining cache coherency. The present invention provides a solution to the shortcomings of the prior art, and offers numerous advantages over existing cache coherency methodologies. SUMMARY OF THE INVENTION The present invention relates to a system and method for providing direct transfers of data segments, such as cache lines, between devices having local memories, such as cache memories, without the need for first transferring the data to a central supervisory memory to maintain cache coherency. This data bypass system and method therefore allows requested data segments stored in a first device to bypass the main memory and travel directly from its current local memory to a requesting device, while also providing for the independent return of the data segment from its current local memory to the main supervisory memory in order to maintain memory coherency. In accordance with one embodiment of the invention, a method is provided for performing direct data transfers from a first local memory of a first device to a second local memory in a second device. The method is for use in a transaction processing system that includes a main memory to provide supervisory storage capability for the transaction processing system, and includes a directory storage for maintaining ownership status of each data segment of the main memory. The method includes requesting a data transfer of the requested data segment in the first local memory to the second local memory. The requested data segment is removed from the first local memory in response to the data transfer request, and directly transferred to the second local memory of the second device. The requested data segment is removed from the first local memory where the data transfer request is one in which ownership of the data is desired, for example where write privileges are desired. The requested data segment may remain in the first local memory if the data transfer request is one where only a copy of the data is desired, such as in a read-only request. The requested data segment is also transferred to the main memory, and to the directory storage where the ownership status can be revised to reflect a change of ownership from the first device to the second device. In the case of a read-only data transfer request, the requested data segment may remain in the first local memory, but ownership must be removed. The direct transfer of the requested data segment between the first and second devices occurs substantially independently of the transfer of the requested data segment from the first device to the main memory and directory storage. In accordance with another embodiment of the invention, a system for bypassing supervisory memory intervention for data transfers between first and second devices is provided. Each of the first and second devices include associated local memories, such as cache memories. The supervisory memory includes a data storage array for providing a centralized storage location for data segments, and further includes a directory storage array for maintaining ownership status of each of the data segments. The system allows a direct transfer of data where the first device requests a transfer of a data segment that is currently residing in the local memory of the second device. The system includes a routing control circuit that provides control signals to direct the movement of the requested data segment in response to a data fetch command provided by the first device. An input queue is coupled to receive the requested data segment from the local memory of the second device in response to first ones of the control signals. An output queue is coupled to receive a first copy of the requested data segment from the input queue in response to second ones of the control signals. The output queue completes the direct data transfer by providing the requested data segment to the local memory of the first device when the requested data segment becomes available in the output queue. A crossbar interconnect circuit is coupled to the routing control circuit to receive third ones of the control signals, and is further coupled to the input queue to receive a second copy of the requested data segment from the input queue. The crossbar interconnect circuit, in response to the third control signals, forwards the second copy of the requested data segment to the supervisory memory to be stored and to revise the ownership status of the requested data segment to reflect new ownership by the first device. The transfer of the requested data segment from the second device to the first device is independent of the transfer of the requested data segment from the second device to the supervisory memory. In accordance with yet another embodiment of the invention, a system is provided for performing a direct data transfer from a first device having a requested data segment stored in a first local memory to a second device having a second local memory. The system includes a main memory to provide supervisory storage capability, and a directory storage for maintaining ownership status of each data segment of the main memory. A circuit for requesting a data transfer of the requested data segment in the first local memory to the second local memory of the second device is provided. Another circuit conditionally removes the requested data segment from the first local memory in response to the data transfer request. The system includes a circuit that transfers the requested data segment to the second local memory of the second device, while a separate circuit transfers the requested data segment to the main memory and the directory storage to respectively store the requested data segment and revise the ownership status to reflect a change of ownership from the first device to the second device. The transfer of the requested data segment to the second local memory is not dependent upon the transfer of the requested data segment to the main memory and directory storage. Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description. As will be realized, the invention is capable of other and different embodiments, and its details are capable of modification without departing from the scope and spirit of the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a Symmetrical Multi-Processor (SMP) System Platform in which the principles of the present invention may be applied; FIG. 2 is a block diagram of one embodiment of a processing module (POD); FIG. 3 is a block diagram of an I/O Module used in connection with the exemplary SMP system; FIG. 4 is a block diagram of one example of a Sub-Processing Module (Sub-POD); FIG. 5 is a block diagram of one embodiment of a Memory Storage Unit (MSU); FIGS. 6A and 6B are Directory Storage Information Bit Formats used to encode the directory in accordance with one embodiment of the invention; FIG. 7 is a block diagram of one embodiment of a bypass buffer mechanism in accordance with the present invention; FIG. 8 is a block diagram of a more specific embodiment of a bypass buffer mechanism within a multi-processor transaction processing system; and FIG. 9 is a flow diagram of a bypass buffer methodology in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS The present invention is directed to a system and method for facilitating efficient transfers of data from a first auxiliary memory to a second auxiliary memory. The invention allows a requested data segment or cache line stored in a local memory to avoid the need to be returned to the main supervisory memory in a system before being provided to another local memory in another device. This data bypass system and method therefore allows the requested data to bypass the main memory and travel directly from its current cache location to the requesting device, while also providing for the independent return of the cache line from its current cache location to the main supervisory memory in order to maintain cache coherency. While the present invention is particularly advantageous in the context of a Symmetrical Multi-Processor (SMP) environment as described below, it will be appreciated by those skilled in the art that the invention may be equally applicable to other computing environments requiring management of cache coherency. Further, the example computing environment described below includes a description of a directory-based cache coherency system within which the present invention is particularly useful. Therefore, the SMP environment and related cache coherency system described in FIGS. 1-6B below is provided for illustrative purposes and to provide a context from which a full operational understanding of the present invention may be obtained; however the invention is not limited thereto. FIG. 1 is a block diagram of a Symmetrical Multi-Processor (SMP) System Platform in which the principles of the present invention may be applied. System Platform 100 includes one or more Memory Storage Units (MSUs) in dashed block 110 individually shown as MSU 110A, MSU 110B, MSU 110C and MSU 110D, and one or more Processing Modules (PODs) in dashed block 120 individually shown as POD 120A, POD 120B, POD 120C, and POD 120D. Each unit in MSU 110 is interfaced to all PODs 120A, 120B, 120C, and 120D via a dedicated, point-to-point connection referred to as an MSU Interface (MI) in dashed block 130, individually shown as 130A through 130S. For example, MI 130A interfaces POD 120A to MSU 110A, MI 130B interfaces POD 120A to MSU 110B, MI 130C interfaces POD 120A to MSU 110C, MI 130D interfaces POD 120A to MSU 110D, and so on. In this example SMP environment, MI 130 comprises separate bi-directional data and bi-directional address/command interconnections, and further includes unidirectional control lines that control the operation on the data and address/command interconnections (not individually shown). The control lines operate at a system clock frequency (SYSCLK) while the data bus runs source synchronous at two times the system clock frequency (2× SYSCLK). For example, in one embodiment, the system clock frequency is approximately 100 megahertz (MHZ). Any POD 120 has direct access to data in any MSU 110 via one of MIs 130. For example, MI 130A allows POD 120A direct access to MSU 110A and MI 130F allows POD 120B direct access to MSU 110B. PODs 120 and MSUs 110 are discussed in further detail below. System Platform 100 further comprises Input/Output (I/O) Modules in dashed block 140 individually shown as I/O Modules 140A through 140H, which provide the interface between various Input/Output devices and one of the PODs 120. Each I/O Module 140 is connected to one of the PODs across a dedicated point-to-point connection called the MIO Interface in dashed block 150 individually shown as 150A through 150H. For example, I/O Module 140A is connected to POD 120A via a dedicated point-to-point MIO Interface 150A. The MIO Interfaces 150 are similar to the MI Interfaces 130, but may have a transfer rate that is approximately half the transfer rate of the MI Interfaces because the I/O Modules 140 are located at a greater distance from the PODs 120 than are the MSUs 110 and produce different timing considerations. FIG. 2 is a block diagram of one embodiment of a processing module (POD). POD 120A is shown, but each of the PODs 120A through 120D have a similar configuration. POD 120A includes two Sub-Processing Modules (Sub-PODs) 210A and 210B. Each of the Sub-PODs 210A and 210B are interconnected to a Crossbar Module (TCM) 220 through dedicated point-to-point Interfaces 230A and 230B, respectively, that are similar to the MI interconnections 130. TCM 220 further interconnects to one or more I/O Modules 140 via the respective point-to-point MIO Interfaces 150. TCM 220 buffers data, and functions as a switch between Interfaces 230A, 230B, 150A, and 150B, and MI Interfaces 130A through 130D. When an I/O Module 140 or a Sub-POD 210 is interconnected to one of the MSUs via the TCM 220, the MSU connection is determined by the address provided by the I/O Module or the Sub-POD, respectively. In general, the TCM maps one-fourth of the memory address space to each of the MSUs 110A-110D. The TCM 220 can further be configured to perform address interleaving functions to the various MSUs. The TCM may also be utilized to perform address translation functions that are necessary for ensuring that each processor (not shown in FIG. 2) within each of the Sub-PODs 210 and each I/O Module 140 views memory as existing within a contiguous address space as is required by certain off-the-shelf operating systems. In one embodiment of the SMP environment, I/O Modules 140 are external to Sub-POD 210 as shown in FIG. 2. This embodiment allows system platform 100 to be configured based on the number of I/O devices used in a particular application. In another embodiment of the present invention, one or more I/O Modules 140 are incorporated into Sub-POD 210. FIG. 3 is a block diagram of an I/O Module used in connection with the exemplary SMP system. I/O Module 140A and Processing Module 120A are illustrated, but it is understood that each I/O Module 140 has a similar structure and interconnection. I/O Module 140A includes a Direct Input/Output Bridge (DIB) 310 connected to one or more Peripheral Component Interconnects (PCIs) in dashed block 320, individually shown as PCI 320A, PCI 320B, and PCI 320C, via one or more dedicated PCI Interfaces 330, shown individually as PCI Interfaces 330A, 330B, and 330C, respectively. DIB 310 is also connected to POD 120A via MIO Interface 150A as is shown in FIG. 2. DIB 310 buffers data, and functions as a switch between PCI Interfaces 330A, 330B, and 330C and MIO Interface 150A, allowing POD 120A access to each of PCIs 320A, 320B, and 320C, respectively. The DIB includes I/O Cache 340 coupled to each of the PCIs in the associated DIB, and is used to buffer read-only data received from an MSU 110 for use by one or more of the various I/O devices associated with the PCIs. The DIB further include an I/O Buffer 350 used to buffer read/write data retrieved from an MSU 110 for the purposes of performing partial write operations. Together, I/O Cache 340 and I/O Buffer 350 may be referred to as I/O Memories. The functionality provided by these I/O memories will be described in more detail below. Peripheral Component Interconnect (PCI) 320 represents a set of industry-standard PCI add-in cards, each of which connects multiple I/O Sub-systems in dashed block 360, individually shown as I/O Sub-systems 360A, 360B, and 360C, to I/O Module 140A via an industry-standard bus. These I/O Sub-systems 360 include, but are not limited to, SCSI controllers, LAN controllers, and video controllers, and various other disk and tape sub-systems. Other I/O bussing architectures could similarly be used in connection with the SMP environment, and the particular I/O bussing architecture selected is not relevant to the cache coherency bypassing methodology of the present invention. In operation, memory data can be retrieved from an MSU 110, and transferred via MIO Interface 150A to an I/O Sub-system 360 such as a tape or disk sub-unit so that a copy may be created. In this instance, it is not necessary to store the memory data in either the I/O Cache 340 or the I/O Buffer 350 as is indicated by Line 370. Memory data may also be retrieved from an MSU 110 to be stored in I/O Cache 340. Data within I/O Cache 340 is available to the I/O Sub-units 360 through the associated PCIs 320 for read-only purposes. The I/O Cache reduces system overhead by reducing the number of read requests that must be presented to an MSU. As stated above, one embodiment of the I/O Cache involves storing the data in the I/O Cache for read purposes only. When data is transferred from an I/O Module to be written to an MSU, one of two methods is utilized. When an entire contiguous block of data is to be written by an I/O Module to an MSU 110, the I/O Module performs an Overwrite operation. The contiguous data block is transferred from an I/O Sub-system such as disk directly to the MSU without being temporarily stored within an I/O Cache 340 or I/O Buffer 350 as is indicated by Line 370. The data provided by the I/O Module will overwrite whatever data signals previously were stored within the MSU. In other instances, the I/O Module is not overwriting an entire contiguous block of memory data but is instead merging data retrieved from an I/O Sub-system into selected addressable portions of a memory block. In these situations, an addressable block of memory data is copied from an MSU 110 to I/O Buffer 350. Data is then retrieved from I/O Sub-system 360 and selectively merged into I/O Buffer 350, and the entire addressable block of memory data is transferred back to the appropriate MSU. This is done so that an MSU is not forced to handle the merging process, which would diminish data throughput. One manner in which these various I/O operations are supported by the cache coherency system of the example memory system is discussed below. FIG. 4 is a block diagram of one example of a Sub-Processing Module (Sub-POD) 210A. Sub-POD 210A is shown, but it is understood that all Sub-PODs 210 have similar structures and interconnections. In this embodiment, Sub-POD 210A includes a Third-Level Cache (TLC) 410 and one or more Coherency Domains 420 (shown as Coherency Domains 420A, 420B, 420C, and 420D). TLC 410 is connected to Coherency Domains 420A and 420B via Bus 430A, and is connected to Coherency Domains 420C and 420D via Bus 430B. TLC 410 caches data from the MSU, and maintains data coherency among all of Coherency Domains 420, guaranteeing that each processor is always operating on the latest copy of the data. Each Coherency Domain 420 includes an Instruction Processor (IP) 450 (shown as IPs 450A, 450B, 450C, and 450D), and a Second-Level Cache (SLC) 460 (shown as SLC 460A, 460B, 460C and 460D.) Each SLC interfaces to an IP via a respective point-to-point Interface 470 (shown as Interfaces 470A, 470B, 470C, and 470D), and each SLC further interfaces to the TLC via Bus 430 (shown as 430A and 430B.) For example, SLC 460A interfaces to IP 450A via Interface 470A and to TLC 410 via Bus 430A. Similarly, SLC 460C interfaces to IP 450C via Interface 470C and to TLC 410 via Bus 430B. Each SLC caches data from the TLC as requested by the interconnecting IP 450. IP 450 and SLC 460 may be integrated in a single device, for example, such as a Pentium Pro® processing device available from the Intel Corporation. Alternatively, the IP 450 may be a A-Series Instruction Processor or a 2200-Series Instruction Processor, both commercially available from the Unisys Corporation. In this embodiment, the IP 450 is externally coupled to an SLC 460. FIG. 5 is a block diagram of a Memory Storage Unit (MSU) 110. Although MSU 110A is shown and discussed, it is understood that this discussion applies equally to each of the MSUs 110. As discussed above, MSU 110A interfaces to each of the PODs 120A, 120B, 120C, and 120D across dedicated point-to-point MI Interfaces 130A, 130E, 130J, and 130N, respectively. Each MI Interface 130 contains Data Lines 510 (shown as 510A, 510E, 510J, and 510N) wherein each set of Data Lines 510 includes sixty-four bi-directional data bits, data parity bits, data strobe lines, and error signals (not individually shown.) Each set of Data Lines 510 is therefore capable of transferring eight bytes of data at one time. In one embodiment, a memory transfer operation involves eight eight-byte transfer operations over a respective set of Data Lines 510. Thus any transfer operation involves 64 bytes, which is termed one "cache line" of data. Data Lines 510A, 510E, 510J, and 510N interface to the Memory Data Crossbar (MDA) 530. The MDA 530 buffers data received on Data Lines 510, and provides the switching mechanism that routes this data between the PODs 120 and an addressed location within the Data Storage Array 540 via Line 535. Data Storage Array 540, which is addressed in 64-byte cache lines discussed above, provides the main storage facility for SMP 100. For each of the cache lines stored in the Data Storage Array, associated status bits are stored in the Directory Storage Array 550. The status bits, referred to as the "Directory Storage Information Bits", records which IP(s) 450 or which IOP 140 has a copy of the associated cache line stored within a local cache memory. Whenever any read or write operation is performed to a cache line within the Data Storage Array 540, the Directory Storage Information Bits associated with that cache line are read from the Directory Storage Array 550. These bits are used to determine how the read or write operation should be processed. For example, these bits may indicate that the Data Storage Array may not contain the most recent copy of the requested cache line because a (possibly updated) copy of the cache line resides in a specified TLC 410. The memory operation will therefore be completed by retrieving this copy from the TLC, forcing the TLC to designate the copy as unusable (invalidate it), and providing the copy to the new requester. The Directory Storage Information Bits will be updated to reflect the newly created copy of the cache line. Control for MSU 110A is provided by the Memory Controller (MCA) 560. MCA includes Request Logic 562 for queuing requests and associated commands from Address/command Lines 520 (shown as 520A, 520E, 520J, and 520N.) The commands are provided by the PODs 120 on behalf of the TLCs 410 and I/O Caches 340 to indicate what type of memory operations are to be performed. The queued requests and the associated commands are provided to Control Logic 564, which generates the routing control information for MDA 530 on Line 566. Control Logic 564 provides address signals to Directory Storage Array 550 and Data Storage Array 540 on Lines 570. Control signals are provided to Directory Storage Array 550 and Data Storage Array 540 on Lines 580 and 582, respectively. Control Logic 564 further provides Mask Signal 584 to Data Storage Array 540 to control which data signals transferred on Line 535 to the Data Storage Array are actually written to the Data Storage Array, as will be discussed further below. MCA 560 further includes Directory State Control 568. During any read or write operation of a cache line stored in Data Storage Array 540, Directory State Control 568 retrieves the associated Directory State Information from the Directory Storage Array 550 across Lines 590. Directory State Control 568 then updates the Directory State Information based on the command associated with the memory request, and further based on the identity of the requesting unit. After this update is performed, the information is written back to the Directory Storage Array. MCA 560 also includes Coherency Control 569. Coherency Control receives Directory Storage Information from Directory State Control 568. In response to this status information, Coherency Control 569 generates control signals to the Request Logic 562 causing Request Logic to issue Functions to one or more the PODs so that the in-progress memory operation may be completed in a manner which guarantees cache coherency. Using the example provided above, assume the Directory Storage Information Bits associated with the requested cache line indicate that the most recent copy of a requested cache line is located in a specified one of the TLCs. Coherency Control 569 receives this information from Directory State Control 568 and generates control signals to Request Logic 562. Request Logic issues the appropriate Function to the POD associated with the specified TLC, thereby causing the TLC to return the requested cache line in a manner to be described below. Data coherency involves ensuring that each POD 120 operates on the latest copy of the data. Since multiple copies of the same data may exist within platform memory, including the copy in the MSU and additional copies in various I/O Caches 340 or Third Level Caches 410, some scheme is needed to control which data copy is considered the "latest" copy. The platform of the current invention uses a directory protocol to maintain data coherency. The directory protocol of the previously-described embodiment stores Directory Storage Information Bits for each of the cache lines stored in an MSU 110. This information is monitored and updated by the MCA 560 when a cache line is read or modified. The Directory Storage Information Bits includes information that indicates which "state" a cache line is in, and further indicates which TLC(s) or I/O Cache may have a copy of the cache line. A cache line "state" provides information about what access privileges are associated with the cache line, and further indicates which actions need to be taken by the MSU and the rest of Platform 100 before a request concerning a particular cache line may be granted. For example, the cache line data may have to be retrieved from one of the TLC or I/O Caches. In other cases, copies of the cache line may have to be invalidated within one or more TLC or I/O Caches before the MSU can provide the request cache line to the requester. In the exemplary system described above, a cache line is in one of the following states, including "MSU Owns", "Exclusive", "Shared", "I/O Copy", "I/O Exclusive", "Deferred", and "Error". All cache lines in the MSU are placed in the "MSU Owns" state after system initialization and before any cache lines have been copied into one of the system caches. This is also the state a cache line enters after it is overwritten with new data received from an I/O sub-system such as disk or tape during an "Overwrite" operation. This state indicates that the MSU has the most recent copy of the cache line. Since only the MSU is considered to have a valid copy of any cache line that is in the MSU Owns state, an error occurs if any of the TLCs or I/O Caches attempts to write to the cache line at this time. A POD may make a request to an MSU to obtain ownership to modify a copy of a cache line. This request is made on behalf of a TLC 410 associated with that POD. When the TLC is provided with the requested cache line, the cache line transitions to the "Exclusive" state. The TLC receiving the cache line is said to be the "Owner" of that cache line, and has read/write access rights. Only one cache may be the Owner of a cache line at once. No other cache may have a copy of the cache line while another cache is the Owner. Once the cache line enters the Exclusive state, the copy of the cache line stored within the MSU is no longer considered valid. When the MSU receives requests for a cache line that is in the Exclusive State, the MSU must retrieve the cache line copy from the Owner during what is referred to as a "Return" operation. As will be described more fully below, the present invention is directed to at least partially bypassing this mandatory data "return", thereby reducing memory latencies. A POD may also request a copy of a cache line for read-only purposes. When a cache line is copied to one of the TLCs for read-only purposes, the cache line state transitions to the "Shared" state. When in this state, the cache line may reside within one, several, or all of the TLCs 410 in Platform 100 at once. The MSU is still considered to have a valid copy of the cache, and may provide this cache line to a TLC making a further read-only request. Another read-only state is the "I/O Copy" state. In the I/O Copy state, the cache line may reside within one I/O Cache 340 and no TLCs. As is the case with the Shared state, the MSU is still considered to have a valid copy of the cache line, and modifications may not occur to the cache line within the I/O Cache. The coherency actions employed when a cache line is in this state are similar to those used when the cache line is in the Shared state. This state is used to provide multiple I/O Sub-systems 360 coupled to I/O Cache 340 with access to MSU data for read-only purposes, thereby reducing the number of requests made to main memory, and I/O-to-memory access times. The "I/O Exclusive" state allows an I/O Buffer 350 to gain an exclusive copy of the cache line with read/write access rights, thereby becoming the cache line Owner. When the cache line is in this state, no other copies may exist within any other cache in the system. Moreover, the Owner is not forced to return the cache line until it has completed the operation. That is, the MSU does not initiate the return of cache lines in this state as a result of subsequent requests by other units. Instead, the Owner returns the cache line on its own accord. This allows an I/O unit to receive a cache line from the MSU, selectively merge data received from a disk or tape sub-system into the cache line, then write the cache line back to main memory after all updates are completed without an MSU performing any coherency operations. This allows system overhead to be reduced in a manner to be described below. A cache line may also be in the "Deferred" state, indicating that the cache line state is in transition. The Deferred state is entered when a request is made for a cache line that is either in the Exclusive or I/O Exclusive state. Since the MSU is not considered to have a valid copy of a cache line that is in either the Exclusive or I/O Exclusive states, the request is deferred until the Owner of the cache line returns access rights and/or the modified copy of the cache line to the MSU. Once the MSU issues a Function to the current Owner initiating the return of the cache line, the cache line must transition to this temporary state. Otherwise, the MSU will (erroneously) issue additional Functions to the current Owner if subsequent requests for this cache line are received before the return of the cache line is completed. Finally, a cache line may also transition to the "Error" state. A cache line transitions to the Error state when the MSU receives an unexpected command. For example, if a cache line is in the MSU Owns state, the MSU should contain the only valid copy of the cache line within the Platform. Therefore, a command attempting to write the cache line from a cache to the MSU is considered an illegal and unexpected operation, and will cause the cache line to transition to the Error state. Once a cache line is in the Error state, it may not be accessed. It remains in the Error state until the MSU is re-initialized, or until an I/O Module 140 makes a request to write new data to the entire cache line during an I/O Overwrite operation. FIGS. 6A and 6B are Directory Storage Information Bit Formats used to encode the directory states described above. The Directory Storage Information Bits may be expressed in two formats. The Ownership Format, which is designated by setting Bit 8 to 0, is shown in FIG. 6A. This format is used whenever a cache line is in any state other than the Shared State. When described in Ownership Format, the cache line state is encoded in bits 7-5. Bits 3-0 encode the identity of a TLC or I/O Cache having a copy of the cache line. More specifically, bits 3-2 identify the POD associated with the cache. Bit 1 indicates whether the cache is coupled to a MIO Interface 150 (I/O Cache) or a MT Interface 230 (TLC). Finally, bit 0 identifies the cache as one of the two TLCs 410 or I/O Caches 340 associated with a given POD. FIG. 6B is the format used to express Directory Storage Information Bits when the associated cache line is in the Shared State. This format, which is designated by setting bit 8 to one, identifies one or more TLC(s) having a shared copy of the cache line using a vector stored in bits 7-0. In both the Ownership and Shared Formats illustrated in FIGS. 6A and 6B respectively, bits 13-9 store the check bits that provide single bit error correction and double-bit error detection on bits 8-0 of the Directory Storage Information Bits. As discussed above, when a POD 120 makes a read request to an MSU 110 for a cache line, the MCA will read the associated Directory Storage Information Bits, update them according to the request, and write them back to the Directory Storage Array 550. The new state of the cache line depends both on the type of request, and the identity of the cache which will obtain a copy of the cache line. The type of request is determined by the "command" provided by the requesting POD 120 on predetermined Address/command Lines 520. The identity of the requesting cache is encoded on other Address/command Lines using an encoding scheme similar to that used within the Directory Storage Information Bits. As discussed above, when the MSU receives a command from one of the PODs, the MSU may respond by issuing a Function to one or more of the PODs to cause some action to occur with respect to the cache line so that cache line coherency will be maintained. It should be noted that in one embodiment of the aforementioned SMP system, the PODs do not initiate the requests of their own accord. Each command is issued by a POD because of a request made by an associated TLC or an I/O Cache. Furthermore, although functions are said to be issued by the MSU to a POD, it should be understood that each of these functions are issued to solicit an action within a TLC or an I/O Cache associated with the POD. In other words, logic within the POD facilitates communications functions occurring between the MSU and the TLC and I/O Caches associated with the POD. A POD issues five types of Commands to the MSU: Fetches, Stores, I/O Commands, Special Commands, and Diagnostic Commands. Fetches generally request that data from the MSU be provided to a TLC. Stores indicate that data and/or access rights are being returned to the MSU by a TLC. I/O Commands include Commands which are counterparts to the Fetches and Stores, but which request that a cache line be transferred from, or provided to, an I/O Cache. Diagnostic Commands are used to inject faults, and to perform verification functions. Special Commands include commands to send a message from one POD to another, which are used in connection with the present invention to allow the MSU to be bypassed in a data transfer. Further, an MSU may have to obtain the latest copy of a cache line before a request may be granted. To obtain this latest copy, the MSU issues return-type functions including the Return-Copy, Return-Purge, and Return-Purge-No-Data Functions. These return-type functions cause a TLC to return cache line data and/or permission rights to the MSU. When the TLC responds to these functions, the data and/or permission rights are returned by the associated POD along with one of the Return Commands. Similarly, a POD issues an I/O Command when an I/O Module wants to read from, or write to, a cache line within an MSU 110. The specific format and definition of general POD commands, I/O commands, and MSU return commands need not be fully described to understand the present invention, and therefore will not be described in full detail here. However, to obtain an appreciation of how such commands and return commands are encoded and issued, reference can be made to copending U.S. patent application, Ser. No. 09/001,598 entitled "Directory Based Cache Coherency System Supporting Multiple Instruction Processor and Input/Output Caches", filed on Dec. 31, 1997, which, as previously indicated, is incorporated herein by reference. The aforementioned description of a cache coherency scheme used in connection with a directory-based memory system sets forth a computer memory environment in which the present invention is applicable. The following description of the present invention is described in terms of the above-described memory system for purposes of explanation and illustration. As will be apparent to those skilled in the art from the following description, the present invention is applicable in other cache coherency environments and is not to be limited to the specific embodiment set forth above. As previously indicated, the present invention provides a bypass mechanism for use in maintaining memory coherency, such as cache coherency, in systems having a main memory as well as multiple local memories used in connection with corresponding processors, input/output devices, or other computing modules. The present invention avoids the need to return data from a current data owning computing module to the main memory prior to providing the data to the requesting computing module. Instead, a requesting module makes a request for data, and if another computing module other than the main memory is the current owner of the data, the data is directly provided to the requesting module. However, coherency must be maintained, and the present invention also provides a manner of maintaining local memory coherency. Therefore, the present invention significantly reduces memory latency for data transfers between computing modules, while maintaining local memory coherency. While the more simple approach to maintaining cache coherency when a requesting POD requests ownership of a cache line currently owned by a second POD would be to force the cache line to be first returned to the main memory, this approach is time-consuming and adversely affects system performance. The present invention provides a mechanism and procedure for allowing the requested cache line to bypass the main memory and travel directly to the requesting POD, while also providing for the independent return of the cache line from the second POD to main memory in order to maintain cache coherency. In one embodiment of the invention, the only relationship between the return of the cache line to the main memory and the transfer of the requested cache line to the requesting POD is an enablement indication to allow the cache line to be returned to the main memory when the POD-to-POD data transfer has reached a predetermined stage of the transfer. However, while bypassing the main memory allows the requesting POD to obtain the requested data faster, it greatly complicates the coherency protocol. This complication results at least in part because the requesting POD may receive the data via the bypass path, update the data in its cache, and flush the data to memory, all before the time the data from the second POD (i.e., the POD having original ownership) ever makes its way back to the memory for coherency purposes. If the memory merely received the requests and processed them in the order received, it would overwrite the most recent data provided by the requesting POD with the outdated data from the second POD that originally owned the cache line. Therefore, the present invention also provides a tracking mechanism and methodology to ensure that memory is provided with the most recent copy of the data. The aforementioned embodiment of the SMP system 100 exemplifies the type of computing environment in which the present invention is particularly useful. Although the present invention is particularly beneficial in such a system, and although a preferred embodiment of the present invention is situated within such an SMP system 100, the present invention is not limited thereto. The present invention is equally applicable in other computing environments having a designated module, such as a memory module, that maintains cache coherency in a multi-cache memory system. In the SMP 100 example, the main memory 110 includes directory storage for maintaining cache line ownership status. Other computing systems implementing memory ownership status where data is returned to the designated module and where the ownership status is updated therein prior to being forwarded to other requesting modules are equally appropriate environments to which the present invention is applicable and beneficial. The ensuing description describes the invention in general terms, and also sets forth the invention in terms of an SMP environment as previously described. Referring now to FIG. 7, a block diagram of one embodiment of a bypass buffer mechanism 700 in accordance with the present invention is provided. The bypass buffer mechanism 700 includes a plurality of local memories, such as cache memories, within various components or modules of the system. For example, these local or cache memories may be associated with processing modules, input/output modules, directly-coupled peripheral devices, and the like. In FIG. 7, two such modules are represented as the Requester 702 of a cache line and the Current Owner 704 of the requested cache line. Both of these devices could be PODs 120 as previously described. Each POD has at least one associated cache memory, and in this case the Requester 702 is requesting a cache line currently "owned" by the Current Owner 704. The Current Owner 704 may "own" the requested cache line because it previously requested the cache line in question and made modifications to that cache line. In order to make such modifications, that device had to obtain ownership of the cache line to maintain cache coherency. The Memory/Directory module 706, analogous to the Data Storage Array 540 and Directory Storage Array 550, changed the ownership status to reflect that device 704 owns the cache line upon obtaining rights to modify it. In prior art systems, a request by one device having a local memory for a data segment owned by another device would require that the data segment be transferred from the owning device to the memory (where ownership status is updated), and finally transferred to the requesting device. In prior art systems, the transfer of the data from the current owner to the memory may be referred to as a "Return" command, indicating that the modified data needed to be returned to the main memory before any other requesting device can obtain the data for modification or even to obtain a copy of the data. However, storing the data in the memory and updating the status prior to providing the data to the requesting device is very time-consuming, and negatively affects system performance. The present invention greatly enhances system performance in such situations. A Bypass Module 708 is provided which works in connection with a Routing Module 710 to allow a cache line (or other locally-owned data segment) to bypass the requirement of first being stored in the Memory/Directory 706 prior to being provided to the Requester 702. The Bypass Module 708 is controlled by a Routing Control Module 712 that directs the requested cache line from the Current Owner 704 on interface 714 directly between Input Queue 716 and Output Queue 718, and on to the Requester 702 via interface 720. However, cache coherency must be maintained. Therefore, the present invention provides another interface, represented by line 722, that provides the requested cache line back to the Memory/Directory 706 via normal routing channels. A Crossbar Interconnect Module 724 also controlled by the Routing Control Module 712 provides the requested cache line back to the appropriate memory location as if a standard Return function had been issued. This allows the Memory/Directory 706 to maintain cache coherency, but does not delay the Requester 702 from obtaining the cache line as quickly as possible. FIG. 8 is a block diagram of a more specific embodiment of a bypass buffer mechanism within a multi-processor transaction processing system. The embodiment of FIG. 8 is described in connection with a transaction processing system such as the SMP system described in connection with FIGS. 1-6, and uses like reference numbers where applicable for major components. For example, the example of FIG. 8 references PODS 120A, 120B, 120C and 120D, MSU 110A, MDA 530, Data Storage Array 540, Directory Storage Array 550, and MCA 560 in order to assist in an understanding of the operability of the present invention within the SMP environment previously described. FIG. 8 is best described by example. A processor associated with a POD, for example POD 120A, issues a Fetch Command on interface 800. The Fetch Command includes a memory address, identification of the requesting POD, and detailed command code. The Fetch Command reaches POD Address Control Block 802 within the MCA 560, which includes a queuing structure for such data transfer requests. The POD Address Control Block 802 determines the destination Memory Cluster Control Block (804, 806, 808, 810) to which the Fetch Command is destined, based on the memory address information. When the Fetch Command in POD ADRS CTRL BLK 802 is scheduled for release from the queuing structure, the Fetch Command is transferred to the appropriate control block on the memory side of the MCA 560, which in this example will be assumed to be Memory Control Block 806, which also includes queuing structures for data transfer requests. The Memory Control Block 806 queuing structures schedules the Fetch Command for further processing based on other pending requests that it has in its queuing structures. When the Fetch Command gains priority in the queuing structure, it is provided to the Directory Storage Array 550 and the Data Storage Array 540 as shown on interfaces 812A and 812B respectively. In other words, when the Fetch Command gains priority it causes a main storage read cycle. Ownership status (i.e., directory state information) is read into the Memory Control block 806 on interface 814, where it is determined whether the requested cache line is owned by the main storage or some other device. This determination is analogous to the previously described Directory State Control 568 previously described in connection with FIG. 5. The Memory Control Block 806 retrieves the associated Directory State Information from the Directory Storage Array 550 across Lines 814, and then updates the Directory State Information based on the command associated with the memory request and on the identity of the requesting unit. A cache line is read from the Data Storage Array 540 and placed into one of the two MSU IN Qs, such as illustrated on line 815. If the ownership status determination function of the Memory Control Block 806 determines that the requested cache line is owned by the main memory (i.e., the Data Storage Array 540), then it issues a read data transfer request to the Data Interconnect Control 816 via interface line 818. In this case, the Memory Control Block 806 schedules the read data transfer request for further processing based on other pending requests for data transfers that are currently in its queue. When the read data transfer request gains priority, the Memory Control Block 806 issues control signals to the MDA 530 via control interface 820 (shown in the embodiment of FIG. 5 as interface 566), which causes the transfer of read data from the appropriate MSU Input Queue (MSU IN Q0, MSU IN Q1) to the appropriate POD Output Queue (POD OUT Q). Also, the Data Interconnect Control 816 signals the data response output queue on the appropriate POD Address Control Block (802) that a data response signal for the requested fetch can be transmitted to the POD 120A as shown by interface 822. As mentioned above, the control signals on control interface 820 cause the transfer of read data from an appropriate MSU Input Queue to the appropriate POD Output Queue in cases where the Memory Control Block 806 determines that the requested cache line is owned by the main memory. The following description explains the manner in which data is transferred in the MDA in response to the control signals on control interface 820 in accordance with one embodiment of the invention. In this example it is assumed that the computing environment includes four Processing Modules (PODs), and the Data Storage Array 540 is divided into four individual Memory Clusters (MCL) in each MSU to which data resides. Multiple MCLs (not shown) allow for address and data interleaving, thereby allowing multiple memory operations to be performed substantially concurrently. In one embodiment, each MCL includes arrays of Synchronous Dynamic Random Access memory (SDRAM) devices and associated drivers and transceivers. It should be noted that the MSU may be populated with as few as one MCL if the user so desires. However, in the present example, it will be assumed that the Data Storage Array 540 includes four individual MCLs. With this configuration, each MDA will include four POD Data Queue Blocks and four MSU Data Queue Blocks. From the description provided herein, it will be readily apparent to those skilled in the art that the number of POD Data Queue Blocks and MSU Data Queue Blocks is dependent upon the number of PODs and MCLs desired in a particular computing environment. However, the principles described herein are equally applicable to any desired configuration. Referring to FIG. 8, each POD Data Queue Block 826, 828, 830, 832 includes two input queues, labeled POD IN Q0 and POD IN Q1. For example, POD Data Queue Block 826 includes POD IN Q0 834 and POD IN Q1 836. POD Data Queue Block 828 includes POD IN Q0 838 and POD IN Q1 840. POD Data Queue Block 830 includes POD IN Q0 842 and POD IN Q1 844, and POD Data Queue Block 832 includes POD IN Q0 846 and POD IN Q1 848. Each of these POD input queues is for receiving data from its respective POD. While each POD Data Queue Block in the illustrated embodiment includes two input queues, the present invention is equally applicable to embodiments including only one input queue per POD Data Queue Block or more than two input queues per POD Data Queue Block. Each POD Data Queue Block 826, 828, 830, 832 also includes one output queue, labeled POD OUT Q. For example, POD Data Queue Block 826 includes POD OUT Q 850, POD Data Queue Block 828 includes POD OUT Q 852, POD Data Queue Block 830 includes POD OUT Q 854, and POD Data Queue Block 832 includes POD OUT Q 856. Each of these POD output queues is for providing data to the respective POD. In the illustrated embodiment, data stored in a POD output queue is received from one of at least two sources, including from a POD input queue which occurs in the case of a POD-to-POD data transfer, or from an MSU input queue which is discussed more fully below. The MDA 530 in FIG. 8 also illustrates that a plurality of MSU Data Queue Blocks 858, 860, 862 and 864 are present in the MDA 530. Each MSU Data Queue Block 858, 860, 862, 864 includes two MSU input queues, labeled MSU IN Q0 and MSU IN Q1. More specifically, MSU Data Queue Block 858 includes MSU IN Q0 866 and MSU IN Q1 868, MSU Data Queue Block 860 includes MSU IN Q0 870 and MSU IN Q1 872, MSU Data Queue Block 862 includes MSU IN Q0 874 and MSU IN Q1 876, and MSU Data Queue Block 864 includes MSU IN Q0 878 and MSU IN Q1 880. Each of the MSU input queues is for receiving data from the main storage to be transferred to a POD output queue in a POD Data Queue Block 826, 828, 830, 832. Each MSU Data Queue Block 858, 860, 862, 864 also includes an MSU output queue, labeled MSU OUT Q. More specifically, MSU Data Queue Block 858 includes MSU OUT Q 881, MSU Data Queue Block 860 includes MSU OUT Q 882, MSU Data Queue Block 862 includes MSU OUT Q 883, and MSU Data Queue Block 864 includes MSU OUT Q 884. Each MSU output queue is for receiving data signals from one of the POD input queues which is to be written to the main storage. The data flow from POD to MSU is initiated by a POD, which provides data to its respective POD input queue destined for an MSU output queue and ultimately to an MCL in the Data Storage Array 540. The data flow from MSU to POD is initiated by an MCL, which provides data to its respective MSU input queue destined for a POD output queue for ultimate transmission to the targeted POD. The data transfer of the MDA 530 can be visualized as sixteen data sources (eight POD input queues and eight MSU input queues) vying for access to eight data destinations (four POD output queues and four MSU output queues). This interconnect is accomplished using the Data Crossbar Interconnect 885. The Data Crossbar Interconnect 885 is capable of connecting any of the POD input queues (834, 836, 838, 840, 842, 844, 846, 848) to any of the MSU output queues (881, 882, 883, 884), and also to any of the POD output queues (850, 852, 854, 856) in the case of a POD-to-POD data transfer. The Data Crossbar Interconnect 885 establishes a proper interconnection under the direction provided by the control signals on control interface 820. These interconnect control signals are at least in part based on the target address corresponding to the data to be transferred. Therefore, where the Memory Control Block 806 determines that the requested cache line is owned by the main memory, the requested data is transferred from an MSU Data Queue Block (858, 860, 862, 864) to a POD Data Queue Block (826, 828, 830, 832). The POD Address Control Block 802 then schedules the transfer of a data response signal along with the requested data on interfaces 824 and 886 respectively. At this point, the Fetch Command where the MSU was the owner of the requested cache line has been completed. If, however, the ownership status determination function of the Memory Control Block 806 determines that the requested cache line is owned by another POD, such as POD 120D, then POD 120D has the latest copy of the data. In this case, POD 120D must release the cache line from its cache, and relinquish ownership of the cache line. Under these circumstances, the Memory Control Block 806 retains the Fetch Command and marks its directory state as "Deferred", which indicates that it is waiting for further processing to be resolved. Because the Memory Control Block 806 determined that another requester owns the data, it initiates a function on interface 887 to the appropriate POD Address Control Block based on the POD identification of the owner, which in this example is POD Address Control Block 888. The function includes the MSU address and detailed command code. In this case, the detailed command code would indicate "Return", which directs the owning POD 120D to return the requested data that is currently residing in its cache. While a Return function typically causes the requested data to be provided only to an addressed portion of the main memory, such a Return function in the present invention causes the owning POD to surrender the requested data, but the requested data is intercepted on its return route to accomplish the POD-to-POD transfer. Other detailed command code types that the MSU might send to a POD include "Purge", which directs a POD to invalidate a cache line copy that it currently holds in its cache. The Return function information supplied by the Memory Control Block 806 also includes data response signal information that is saved in the POD Address Control Block 888, and used to supply the data response signals to the destination POD at a later time, when the data is returned by the current owner--POD 120D. The POD Address Control Block 888 schedules the return function for further processing based on other pending return and purge functions that it is currently managing. It uniquely identifies each particular return function with an identifier, referred to as a Memory Job Number (MJN). The MJN accompanies the MSU address and detailed command information. The MSU address will direct the surrendered data to the appropriate location in the main memory, although this surrendered data will also be intercepted in order to provide a direct POD-to-POD data transfer as is described more fully below. The POD Address Control Block 888 then schedules the transfer of the return function to the POD 120D via interface 889, based on the current state of the address/command bus associated with interface 889, which was generally shown as part of Address/Command Lines 520N in FIG. 5. The management of data transfers across the POD/MSU bus 130 (see FIG. 1) may be determined in a manner described herein and in copending U.S. patent application, Ser. No. 09/096,624 entitled "Bi-Directional Interface Distributed Control Mechanism", filed on Jun. 12, 1998, which is assigned to the assignee of the instant application, the contents of which are incorporated herein by reference. The MSU 110A then awaits the return of the requested data from POD 120D. The POD 120D eventually receives the return function via interface 889, and returns the requested data using both command and data interfaces, labeled interface 890A and 890B respectively. The detailed command code in the returned POD command indicates a "Store Return" type, and the unique MJN identifier is included in this POD command for future identification purposes. The command information is returned to the POD Address Control Block 888 and the data is provided to the MDA 530 via interface 890B. In this particular example, the data is returned from POD 120D to the POD Data Queue Block3 832 to the POD Input Queue-0 846. The POD Address Control Block 888 receives the POD Store Return command and accesses information stored within the POD Address Control Block 888 that was earlier saved. This saved information includes data response signal information used to supply the data response signals to the destination POD. This saved information is located within the POD Address Control Block 888 using the unique MJN previously created by the POD Address Control Block 888 and returned to the POD Address Control Block 888 along with the Store Return command. The saved information in the POD Address Control Block 888 includes an identification of the requesting POD that is awaiting the returned data, as well as the data response signals to transmit back to the requesting POD 120A. The POD Address Control Block 888 lines up or correlates the Store Return command with its associated inbound data transfer. Such a "correlation" matches data and address signals associated with the same request, and may be determined in a manner described herein and in copending U.S. patent application, Ser. No. 09/096,822 entitled "Queueing Architecture And Control System For Data Processing System Having Independently-Operative Data And Address Interfaces", filed on Jun. 12, 1998, which is assigned to the assignee of the instant application, the contents of which are incorporated herein by reference. When both the command and data components of the Store Return command are present, the Store Return is enabled for further processing. The POD Address Control Block 888 schedules the Store Return command for delivery to the Data Interconnect Control 816 based on other pending requests that it is processing in its request queue. Upon the Store Return command gaining priority in the queue, the POD Address Control Block 888 delivers the Store Return command to the Data Interconnect Control 816 via interface 891, and further retains the Store Return command to deliver back to the Memory Control Block 806 at a later time in order to update the main storage data and directory state. The Data Interconnect Control 816 receives the Store Return command and schedules the return data transfer request for further processing based on other pending requests for data transfers that it is currently managing. When the return data transfer request identified by the Store Return command gains priority, the Data Interconnect Control 816 issues control signals to the MDA(s) 530 via control interface 820 to cause the transfer of the returned data from the appropriate POD Input Queue, which in this case is POD Input Queue-0 846, to the destination POD Output Queue, which in this case is POD Output Queue 850, via data interface 895. Also, the Data Interconnect Control 816 signals the data response output queue of the destination POD Address Control Block 802 via interface 822 that a data response signal to the requested fetch command can be transmitted to the requesting POD 120A. Additionally, the Data Interconnect Control 816 communicates to the POD Address Control Block that was the source of the Store Return command (POD Address Control Block 888 in this example) that this unique data return has been delivered to an output queue in the MDA 530, using the corresponding Memory Job Number (MJN). The destination POD Address Control Block (POD Address Control Block 802 in this example) schedules the transfer of the data response signal plus the actual requested data across the POD/MSU interface 130. In the example of FIG. 8, this is accomplished by transferring the data response signal from POD Address Control Block 802 to POD 120A via interface 824, and by transferring the requested data from POD Output Queue 850 of POD Data Queue Block-0 826 to POD 120A via data interface 886. The original Fetch Command has now been satisfied by the MSU 110A, and the POD-to-POD data transfer is complete. However, cache coherency must be maintained by properly updating the cache line ownership status in the Directory Storage Array 550 and returning the data to the Data Storage Array 540. Therefore, the POD Address Control Block 888 locates the original Store Return command in its input request queue and marks the Store Return command for delivery to the appropriate Memory Control Block (Memory Control Block 806 in this example). In a preferred embodiment, these activities take place in parallel with certain activities related to the transfer of the requested data to the requesting POD. For example, the activities surrounding the return of the Store Return command to the Directory Storage Array 550 and Data Storage Array 540 can be initiated during the time that the POD Address Control Block 802 is scheduling the transfer of the data and the data response signal to the requesting POD 120A. These parallel activities increase overall system performance. As previously indicated, when the Memory Control Block 806 originally initiated the Return Function to the POD Address Control Block 888, the POD Address Control Block 888 saved the information therein. Therefore, when the POD Address Control Block 888 has located the original Store Return command in its input request queue and has marked the Store Return command for delivery to Memory Control Block 806, the POD Address Control Block 888 uses the MJN to invalidate that original return function entry so that the MJN is now available for a new return function. The Store Return command is delivered via interface 892 to the Memory Control Block 806 based on priority scheduling of other requests currently being managed by the POD Address Control Block 888 queuing circuitry. The Memory Control Block 806 then receives the Store Return command and locates the original Fetch Command it is holding that was earlier marked as "Deferred". The Store Return command indicates that the Fetch Command has now been satisfied so that the Memory Control Block 806 can now schedule the writing of the returned data back to the Data Storage Array 540 via interface 899 and marking the current directory state of the cache line(s) in the Directory Storage Array 550 to reflect that POD 120A is the new "owner" of the respective cache line(s). The directory state of the cache line will change from "Deferred" to "Exclusive" in this example, and this directory state change will mark the completion of the POD-to-POD data transfer transaction. The activities surrounding the return of the data to the Directory Storage Array 550 and the Data Storage Array 540 occur independently of the activities surrounding the transfer of the requested data to the requesting POD 120A. In other words, by the time the Directory Storage Array 550 and the Data Storage Array 540 receive the returned data and log the ownership change, POD 120A will have already received the requested data for its use. Therefore, not only does POD 120A typically receive the data prior to the returned data reaching the directory and main data storage, POD 120A does not have to wait for a data transfer from the main data storage back to POD 120A as in the prior art. The timing is of course dependent on the state of the queuing structures throughout the system, but on average this results in a substantial reduction in the time required for the requesting device to receive the requested data. For example, disregarding queuing delays throughout the various command and data transfer paths, the performance increase using the bypass acceleration mechanism and method of the present invention can be illustrated by comparing the number of clock cycles required to perform a POD-to-POD transfer with and without the benefit of the present invention. In the following example, the MSU clock cycles are measured from the first clock cycle of the POD Store Return command transmission at the owning POD output (e.g., POD 120D) to the first clock cycle of actual data transmission to the requesting POD (e.g., POD 120A). This comparison calculated in connection with an embodiment such as described in connection with FIG. 8 is illustrated in Table 1 below for a POD-to-POD transfer: TABLE 1 ______________________________________ Number of Clock Cycles ______________________________________ Without Bypass Mechanism 40 Of Present Invention With Bypass Mechanism Of 7 Present Invention ______________________________________ As can be seen, in the case where the bypass mechanism of the present invention is not employed and the returned data must first be written to main storage and then retrieved from main storage to be provided to the requesting device, approximately 40 clock cycles occur by the time the actual data transmission is initiated. Alternatively, using the present invention, this is reduced to 7 clock cycles, which is a substantial increase in performance. Again, this example does not account for queuing delays, but illustrates the relative difference of time required to perform a POD-to-POD transfer when implementing or not implementing the present invention. FIG. 9 is a flow diagram of a bypass buffer methodology in accordance with one embodiment of the present invention. A requesting device issues a request for data as shown at block 900. This request may be in the form of a Fetch Command or other command which would typically require a change of data segment (e.g., cache line) ownership. It is determined 902 whether the requested data segment is currently owned by main storage. If the requested data segment is owned by the main storage, the main storage provides the data segment to the requesting device via normal channels, as seen at block 904. For example, the data segment is transferred between main memory queuing structures and requesting device queuing structures via a data transfer module such as the Data Crossbar Interconnect 885 shown in FIG. 8, and the data segment is subsequently transferred to the requesting device. The ownership directory is updated 906 to reflect new ownership by the requesting device, and the transaction is complete. If, as determined at block 902, the requested data segment is not owned by the main storage, the current owner of the data segment is determined 908. It should be noted that the determination of the current owner of the data segment at block 908 and the determination of whether the main storage owns the data segment at block 902 can be performed coterminously, and need not be performed in a sequence suggested by the flow diagram of FIG. 9. The determination of the current owner of the data will provide an identification of a POD, I/O module, or other module currently owning the requested data segment. It should be recognized that in one embodiment of the invention, each POD includes multiple (e.g., two) processors each having an associated cache. Therefore, a data segment can actually be owned by the same POD requesting the data segment, but the current owner of the data segment would be a non-requesting processor within the POD. The ownership status at the ownership directory will be set to a "deferred" state as indicated at block 910, which indicates that the cache line state is in transition. A "Return" command is issued 912 to the current owner of the data segment to obtain the data segment. At this time, the data segment is directly transferred 914 to the requesting device's output queue, and thereafter is output 916 to the requesting device. By providing the returned data directly to the input queue of the requesting device, the requesting device does not have to wait the time it would take to transfer the data back to the main storage, and then back to the requesting device's output queue. In order to maintain cache coherency, the returned data segment is also transferred 918 to the main memory output queue. So, although the data will be returned to the main storage to maintain cache coherency, the requesting device was not forced to wait until all of this processing occurred. The embodiment of FIG. 9 illustrates the parallel and independent nature of the returned data segment as compared to the transfer 914 of the data to the requesting device. However, in one embodiment of the invention, the transfer 914 occurs first, and the transfer 918 is triggered after the data has been transferred 914 to the requesting device output queue, as indicated by dashed line 917. From the main memory output queue the data segment is output 920 to the main memory. The deferred ownership status is then removed 922, and the ownership directory is updated 924 to reflect that the requesting device is now the new owner of the data segment or cache line. In one embodiment of the invention, the transfer of the returned data to the main storage for purposes of maintaining cache coherency occurs concurrently with the transfer of the returned data to the requesting device. However, the transfer of the returned data could alternatively be transferred after the data segment was provided to the requesting device without departing from the scope and spirit of the invention. As long as the ownership status is defined in the "Deferred" state until the returned data reaches the main memory, coherency will be maintained. However, performing these two operations in parallel further increases system throughput and overall system performance. It should also be noted that the transfer 918 of the returned data to the main memory output queue is required where the associated data transfer request is one where ownership privileges, such as data write privileges, are desired. In these cases, the data must be removed from the current owner of the data, and output 920 to the main memory along with modifying the ownership status 922, 924. However, in cases where the data transfer request is only for a read-only copy of the data segment, ownership by the requesting device is not necessary. Ownership is still updated to designate the main memory the owner of the requested data, but in this case the device can retain a copy of the requested data that is being provided to the requesting device and a read-only copy of the requested data is provided to the requesting device. The "Shared" state previously described is an example of such a situation, where the requested cache line may reside within one, several, or all of the local memories at once. The MSU is still considered to have a valid copy of the cache, and may provide this cache line to a local memory making a further read-only request. The invention has been described in its presently contemplated best mode, and it is clear that it is susceptible to various modifications, modes of operation and embodiments, all within the ability and skill of those skilled in the art and without the exercise of further inventive activity. Accordingly, what is intended to be protected by Letters Patents is set forth in the appended claims. What is claimed is: 1. A method for performing a direct data transfer from a first device having a requested data segment stored in a first local memory to a second device having a second local memory, the method for use in a transaction processing system having a main memory to provide supervisory storage capability for the transaction processing system, the transaction processing system further having a directory storage for maintaining ownership status of each data segment of the main memory, the method comprising:requesting a data transfer of the requested data segment in the first local memory to the second local memory of the second device; transferring the requested data segment from the first local memory to the second local memory of the second device in response to the data transfer request; transferring the requested data segment to the main memory and the directory storage to revise the ownership status to reflect a change of ownership from the first device to the second device; and wherein the requested data segment is transferred to the second local memory independent of the transfer of the requested data segment to the main memory and directory storage. 2. The method of claim 1, further comprising determining the ownership status of the requested data segment by accessing one or more ownership status bits corresponding to the requested data segment from the directory storage, and allowing a direct transfer of the requested data segment from the first device to the second device where the one or more ownership bits establish the first device as the current owner of the requested data segment. 3. The method of claim 1, wherein transferring the requested data segment from the first local memory to the second local memory comprises removing the data from the first local memory if the data transfer request indicates a command where ownership privileges are required by the second device. 4. The method of claim 3, further comprising:determining the ownership status of the requested data segment by accessing one or more ownership status bits corresponding to the requested data segment from the directory storage; allowing a direct transfer of the requested data segment from the first device to the second device where the one or more ownership bits establish the first device as the current owner of the requested data segment; setting the ownership status of the requested data segment to a pending state until the requested data segment has been transferred to the main memory and directory storage; and revising the ownership status to reflect ownership by the second device when the requested data segment has been transferred to the main memory and directory storage. 5. The method of claim 1, wherein transferring the requested data segment from the first local memory to the second local memory comprises transferring a copy of the data from the first local memory to the second local memory and retaining the data in the first local memory if the data transfer request indicates a command where ownership privileges are not required by the second device. 6. The method of claim 5, further comprising:determining the ownership status of the requested data segment by accessing one or more ownership status bits corresponding to the requested data segment from the directory storage; allowing a direct transfer of the requested data segment from the first device to the second device where the one or more ownership bits establish the first device as the current owner of the requested data segment; setting the ownership status of the requested data segment to a pending state until the requested data segment has been transferred to the main memory and directory storage; and revising the ownership status to reflect ownership by the main memory when the requested data segment has been transferred to the main memory and directory storage. 7. The method of claim 1, wherein transferring the requested data segment to the second device and transferring the requested data segment to the main memory and directory storage comprises performing the transfers in parallel. 8. The method of claim 1, wherein transferring the requested data segment to the main memory and directory storage comprises controlling the transfer of the requested data segment to the main memory and directory storage independent of the control of the transfer of the requested data segment to the second device. 9. The method of claim 1, wherein at least a portion of a data transfer path of the requested data segment to the second device is separate and distinct from a data transfer path of the requested data segment to the main memory and directory storage. 10. The method of claim 1, further comprising generating a data return command to direct the first device to surrender the requested data segment from the first local memory in response to the data transfer request. 11. The method of claim 1, wherein transferring the requested data segment from the first local memory to the second local memory comprises transferring the requested data segment from the first local memory to a temporary storage location prior to transferring the requested data segment to the second local memory. 12. The method of claim 11, wherein transferring the requested data segment to the second local memory of the second device comprises transferring the requested data segment from the temporary storage location to an output queue designated to output data to the second local memory. 13. The method of claim 12, wherein transferring the requested data segment from the first local memory to a temporary storage location further comprises transferring the requested data segment from the first local memory to an input queue designated to receive data from the first local memory. 14. The method of claim 1, wherein requesting a data transfer comprises issuing a data fetch command from the second device for processing by the transaction processing system. 15. The method of claim 1, wherein:transferring the requested data segment from the first local memory to the second local memory comprises transferring the requested data segment from the first local memory to a temporary storage location prior to transferring the requested data segment to the second local memory; and transferring the requested data segment to the main memory and directory storage is initiated upon receipt of an indication that the requested data segment has reached the temporary storage location. 16. A system for bypassing supervisory memory intervention for data transfers between first and second devices having associated local memories, wherein the supervisory memory includes a data storage array for storing a plurality of data segments and a directory storage array for maintaining ownership status of each of the data segments, and wherein the first device requests a transfer of a requested data segment currently residing in the local memory of the second device, the system comprising:a routing control circuit configured and arranged to provide control signals to direct the movement of the requested data segment in response to a data fetch command provided by the first device; an input queue coupled to receive the requested data segment from the local memory of the second device in response to first ones of the control signals; an output queue coupled to receive a first copy of the requested data segment from the input queue in response to second ones of the control signals, and to complete the data transfer by providing the requested data segment to the local memory of the first device upon availability of the requested data segment in the output queue; a crossbar interconnect circuit coupled to the routing control circuit to receive third ones of the control signals, and coupled to the input queue to receive a second copy of the requested data segment from the input queue, wherein the crossbar interconnect circuit, in response to the third control signals, forwards the second copy of the requested data segment to the supervisory memory to be stored and to allow the ownership status of the requested data segment to be revised to reflect new ownership by the first device; and wherein the transfer of the requested data segment from the second device to the first device occurs in parallel with the transfer of the requested data segment from the second device to the supervisory memory. 17. The system as in claim 16, further comprising:a first device interface coupled to the first device to receive the fetch command from the first device; a memory interface coupled to the first device interface to receive the fetch command, wherein the fetch command includes an address of the requested data segment; a directory control circuit coupled to the memory interface to receive the address, and coupled to the directory storage array to receive the ownership status of the requested data segment in response to the address; a second device interface coupled to the second device to provide a data return command to the second device when the directory control circuit establishes that the requested data segment is currently residing in the local memory of the second device; and wherein the second device surrenders the requested data segment in response to the data return command. 18. The system as in claim 16, wherein the directory control circuit comprises means for modifying the ownership status. 19. The system as in claim 18, wherein the means for modifying the ownership status comprises means for changing the ownership status to a pending state until the supervisory memory receives the second copy of the requested data segment. 20. The system as in claim 16, wherein the system comprises a plurality of devices having associated local memories, and wherein the data transfers can be performed between any two of the plurality of devices. 21. The system as in claim 20, wherein the system comprises a plurality of the input queues and a plurality of the output queues, and wherein each of the plurality of devices is coupled to a different one of the plurality of the input queues to provide requested ones of the data segments, and wherein each of the plurality of devices is further coupled to a different one of the plurality of the output queues to provide requested ones of the data segments. 22. The system as in claim 16, further comprising a memory output queue coupled to the crossbar interconnect circuit to receive the second copy of the requested data segment and to forward the second copy of the requested data segment to the supervisory memory upon availability of the second copy of the requested data segment in the memory output queue. 23. The system as in claim 16, wherein the local memories comprise cache memories and the requested data segment comprises a requested cache line. 24. The system as in claim 16, wherein the first ones of the control signals comprise an address of the input queue which is to receive the requested data segment from the second device. 25. The system as in claim 24, wherein the second ones of the control signals comprise:the address of the input queue that received the requested data segment; and an address of the output queue which is to receive the first copy of the requested data segment from the input queue. 26. The system as in claim 24, wherein the system further comprises a memory output queue coupled to the crossbar interconnect circuit to receive the second copy of the requested data segment and to forward the second copy of the requested data segment to the supervisory memory upon availability of the second copy of the requested data segment in the memory output queue; and wherein the third ones of the control signals comprise:the address of the input queue that received the requested data segment; and an address of the memory output queue which is to receive the second copy of the requested data segment from the input queue. 27. A system for performing a direct data transfer from a first device having a requested data segment stored in a first local memory to a second device having a second local memory, the system including a main memory to provide supervisory storage capability and a directory storage for maintaining ownership status of each data segment of the main memory, comprising:means for requesting a data transfer of the requested data segment in the first local memory to the second local memory of the second device; first data transfer means for transferring the requested data segment from the first local memory to the second local memory of the second device in response to the data transfer request; second data transfer means for transferring the requested data segment to the main memory and the directory storage to respectively store the requested data segment and revise the ownership status to reflect a change of ownership from the first device to the second device; and wherein the transfer of the requested data segment to the second local memory is not dependent upon the transfer of the requested data segment to the main memory and directory storage. 28. The system as in claim 27, further comprising:means for determining the ownership status of the requested data segment by accessing one or more ownership status bits corresponding to the requested data segment from the directory storage; and means for allowing a direct transfer of the requested data segment from the first device to the second device where the one or more ownership bits establish the first device as the current owner of the requested data segment. 29. The system as in claim 28, further comprising means for setting the ownership status of the requested data segment to a pending state until the requested data segment has been transferred to the main memory and directory storage, at which time the ownership status is revised to reflect a new ownership of the requested data. 30. The system as in claim 29, wherein:the first data transfer means comprises means for transferring a copy of the requested data segment to the second local memory while retaining the requested data segment in the first local memory if the data transfer request indicates a command where ownership privileges are not required by the second device; and the ownership status is revised to reflect ownership by the main memory when the requested data segment has been transferred to the main memory and directory storage. 31. The system as in claim 29, wherein:the first data transfer means comprises means for removing the requested data segment from the first local memory to the second local memory if the data transfer request indicates a command where ownership privileges are required by the second device; and the ownership status is revised to reflect ownership by the second device when the requested data segment has been transferred to the main memory and directory storage. 32. The system as in claim 27, further comprising control means for providing first control signals to control the transfer of the requested data segment to the second local memory, and for providing second control signals to control the transfer of the requested data segment to the main memory and the directory storage. 33. The system as in claim 32, further comprising first buffer means for receiving the requested data segment from the first local memory, and for temporarily storing the requested data segment until receiving the first control signals at which time a first copy of the requested data segment is provided to the second local memory. 34. The system as in claim 32, further comprising second buffer means for receiving a second copy of the requested data segment from the first buffer means and for temporarily storing the second copy of the requested data segment until receiving the second control signals at which time the second copy of the requested data segment is provided to the main memory and the directory storage.

1998-12-22

en

2000-12-26

US-66859096-A

Conduit fast connection ABSTRACT A conduit, to be attached to a fluid port in a block or wall, has an enlarged end with a sealing ring and an attachment plate with a cut-out engaging the enlarged end, preferably with the plate secured against the enlarged end by a retaining ring or convolution. The plate has an attachment hole with a snap ring in the hole which is snap-locked onto a barbed stud threaded into the block retaining the enlarged conduit end in the fluid port. The conduit is disconnected by unthreading the stud through the plate hole from the block. BACKGROUND OF THE INVENTION The present invention relates to conduit attachments and particularly conduit employed for communicating flow of pressurized refrigerant and the connection of such conduits to a wall or block such as in a refrigerant expansion valve or receiver/drier header. The present invention relates to the fast or quick connection of refrigerant conduits to a wall or block and particularly relates to such quick connection in the assembly and installation of automotive passenger compartment air conditioning systems in high-volume mass production. Heretofore, it has been the practice in installing air conditioning conduits in automotive mass production to utilize a connection of the type having a connector plate attached to the end of the refrigerant conduit to be connected; and, the connector plate is fastened to the block or wall having a fluid connecting port for connection to the conduit, the attachment being made typically by threaded fasteners such as a machine screw or bolt received through the plate. The aforesaid known type of conduit connection employed for refrigerant conduits attached to a port in a block or wall B is shown in FIG. 5 where a plate 1 is attached to the conduit 2 and is sealed in a port 3 by means of a protrusion 4 on the plate having an annular seal ring 5 received in the port. The conduit 2 is attached to the plate by a crimped flange 6; and, a separate hole 7 is provided in the plate for attachment to the block by means of a suitable threaded fastener 9. The aforesaid manner of attachment of a refrigerant conduit to a port formed on a block or wall has thus required the threading and tightening of a bolt during installation. This bolt installation has been found troublesome in high-volume mass production where, due to the orientation of the system components in the engine compartment, the installer has limited access to the bolt. In such typical installations it is difficult to engage the bolt head with appropriate tools for tightening the bolt. Thus, it has been desired to provide a quick or fast connection for the refrigerant conduit to a block port without the need of any separate fasteners or tools. SUMMARY OF THE INVENTION The present invention provides a quick or fast connection of a conduit to a port in a block or wall and is particularly suitable for quick connection of conduits to such a port for flow of pressurized refrigerant through the conduit to the port. The present invention has particular applicability to the assembly and installation of refrigerant conduit in automotive air conditioning systems where it is desired to provide a quick connect without the need for separate fasteners or tools of a conduit to a port in a block or wall of a system component in high-volume mass production. The present invention provides a conduit having an enlargement or protrusion on the conduit end to be connected to the port. An attachment plate has a cut-out therein with the conduit received in the cut-out and contacting the enlargement. Preferably the conduit is secured thereto by a pair of convolutions or rings formed on the conduit. A pre-assembled stud is releasably fastened to the block or wall adjacent the fluid port; and, a separate cut-out or aperture in the plate is received over the stud and snap-locked thereon with the enlarged end of the conduit being simultaneously inserted and sealed in the port. The snap-locking is preferably accomplished by a snap ring provided in the plate aperture which is snapped over an undercut or barb provided on the stud. If it is desired subsequently to remove the connection, the stud may be removed such as by unthreading from the block or wall and the plate and conduit removed. The present invention thus provides a unique and novel technique for assembling a fluid pressure conduit to a port in a block or wall with a quick connect or snap-lock attachment over a stud which makes the connection between the conduit and the fluid port and retains the conduit secured therein without separate tools or fasteners. The connection may thereafter be broken or disconnected by unthreading the stud. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of the conduit connection of the present invention; FIG. 2 is a view of the components of FIG. 1 in the assembled condition; FIG. 3 is an alternate arrangement of the embodiment of FIG. 2; FIG. 4(a) is a view similar to FIG. 1 illustrating the initiation of the sequence of assembly of FIG. 2; FIG. 4(b) is a view similar to FIG. 1 showing partial assembly; FIG. 4(c) is a view similar to FIG. 2 showing completion of the assembly sequences; and, FIG. 5 is a view similar to FIG. 1 of the prior art connection. DETAILED DESCRIPTION Referring to FIGS. 1 and 2, the conduit connection of the present invention is indicated generally at 10 and includes a conduit or tube 12 having an enlarged end indicated generally at 14 and which has an annular groove 16 formed thereon into which is received an annular seal ring 18. An attachment plate 20 has a cut-out formed therein which may either be an aperture or an open slot into which the conduit 12 is received. In the presently preferred practice an annular ring 24 is received over the conduit 12 and secured thereto for retaining the conduit in the cut-out 22. However, alternatively ring 24 may be formed integrally in the tube wall as a convolution, as may the enlarged end 14. Although the presently preferred practice has the conduit secured to the plate 22 by a second enlargement, convolution or ring 28, it will be understood that, in its simplest form the invention may be practiced with only the single enlargement 14. Attachment plate 20 has a second cut-out or aperture 26 with a reduced diameter portion 27 and formed therein spaced from the cut-out 22 with a resilient snap ring 28 received therein and retained by a collar or ring 30 pressed in the aperture 26. Ring 28 is shown in FIG. 2 as having a rectangular cross section, but a circular cross section ring may also be employed. A block or wall 32 such as the block of an expansion valve or header of a receiver/drier, has a fluid port 34 formed therein which is sized and configured to have received therein the enlarged end 14 of conduit 12 in a manner such that seal ring 18 is compressed in groove 16 and a fluid pressure fight seal is formed therebetween. A bore 36 is formed in block 32 spaced from port 34 by an amount to coincide with aperture 26. Bore 36 has a stud 38 releasably and preferably threadedly engaged therein; and, the portion of stud 38 extending externally of the bore 36 is provided with a taper 40 and an undercut or relief is provided adjacent the largest diameter of the taper thereby forming an annular barb on the stud. It will be understood that stud 38 is provided pre-assembled to the block 32 and is tus in place at the time of the connection of conduit 12. Referring to FIG. 4(a), the conduit connection of the present invention is shown at the beginning of installation. In FIGS. 4(a), (b) and (c) the invention is shown using an alternative configuration for the snap ring 28' having a circular transverse section. In FIG. 4(a) the tapered portion 40 of the stud 38 is illustrated as inserted into the aperture 26 to a point where it initially contacts the snap ring 28'. Referring to FIG. 4(b), the plate 22 has been moved downwardly an additional amount from the position shown in FIG. 4(a) until the taper 40 of the stud 38 has expanded the snap ring 28' to its greatest diameter and to a condition where it is at incipient snap-over of the taper 40. Referring to FIG. 4(c), the plate 22 has been moved downwardly to contact the upper surface of block 32 and the tapered portion 40 of stud 38 has passed through the snap ring 28' which has now contracted or snapped into the undercut region 39 of the stud 38 such that ring 28' prevents removal of the plate by the engagement of the reduced diameter portion 27 of aperture 26 with the ring 28'. If it is subsequently desired to remove the conduit from engagement with the port 34, the stud 38 may be removed by insertion of a tool (not shown) such as an Allen wrench or hexagonal bit into the socket 41 through the plate aperture 26 and the stud unthreaded from block 32. Referring to FIG. 3, an alternate embodiment of the invention is indicated generally at 50 as having the adaptor plate 122 formed with a conically tapered portion in the aperture 126 and an undercut 139 formed adjacent the smallest diameter of the tapered portion 140 thereby forming an internal annular barb. A stud 138 has the upper portion thereof formed with a straight cylindrical configuration; and, an annular groove 143 is formed thereon into which snap ring 28' is engaged and resiliently compressible therein such that the ring 28' may pass through the tapered portion 140 and expand into undercut 126 an amount sufficient to retain the plate 122 on the stud 138. The present invention thus provides a novel and unique quick or fast connection for a conduit for communicating pressurized fluid to a port formed in a block or wall. A connection plate secured to the conduit is snap-locked over a tapered stud provided in releasable, preferably threaded engagement with the block or wall. Subsequent disconnection of the conduit is enabled by unthreading of the stud from the block or wall. Although the present invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the of the following claims. We claim: 1. A method of connecting a tubular conduit to a wall or block for flowing pressurized fluid therethrough comprising:(a) forming a protrusion or enlargement on an end of a tubular conduit; (b) providing an attachment plate and forming a cut-out therein and forming an aperture therein spaced from said cut-out; (c) disposing said conduit in said cutout; (d) forming a fluid pressure port in said wall and inserting said enlargement in said port and sealing therebetween; (e) providing a stud and releasably securing said stud to said wall or block; and, (f) disposing a resiliently deflectable member between said stud and aperture and inserting said stud in said aperture and deflecting said resilient member and retaining said plate on said block or wall and said conduit in said port. 2. The method defined in claim 1, wherein said steps of disposing a resiliently deflectable member includes forming an undercut or relief and inserting a spring therein. 3. The method defined in claim 1, wherein said step of releasably securing said stud includes threadedly engaging said stud with said block or wall. 4. The method defined in claim 1, wherein said step of sealing between said port and said enlargement includes forming an annular groove in said conduit enlargement and disposing a resilient ring therein. 5. The method defined in claim 1, further comprising releasing said stud from said block and disconnecting said conduit from said port. 6. The method defined in claim 1, wherein said step of forming an enlargement includes forming at least one convolution in the wall of said conduit. 7. A method of releasably quick-connecting a fluid pressure conduit to a port in a block or wall comprising:(a) removably mounting a stud on said block spaced from said port; (b) forming an enlargement or protrusion on an end of said conduit and inserting said enlargement in said port; (c) providing an attachment plate and forming a cut-out in said plate and an aperture spaced from said cut-out; (d) disposing said conduit in said cut-out and contacting said enlargement with said plate; (e) releasably securing a stud to said block or wall and inserting said stud in said plate aperture and retaining said plate on said stud; and, (f) removing said stud for disconnecting said conduit from said port. 8. The method defined in claim 7, wherein said step of removably mounting a stud includes threadedly engaging said stud in said block. 9. The method defined in claim 7, wherein said step of inserting said enlargement includes disposing a seal between said enlargement and said port. 10. The method defined in claim 7, wherein said step of inserting said stud includes snap-locking. 11. The method defined in claim 7, wherein said step of retaining said plate on said stud includes disposing a spring member in said aperture and deflecting said spring member. 12. The method defined in claim 7, wherein said step of disposing said conduit in said cut-out includes securing said conduit to said plate. 13. The method defined in claim 7, wherein said step of disposing said conduit in said cutout includes forming a pair of convolutions in the wall of said conduit and securing said conduit to said plate.

1996-06-19

en

1998-03-17

US-23445451-A

Polymers from dihydric phenols and disulfonic esters of diols Patented June 8, 1954 UNITED STATES PATENT OFFICE POLYMERS FROM DIHYDRIC PHENOLS AND DISULFONIC ESTERS OF DIOLS Frank Reeder, Killay, Swansea, Wales, and Eric Richard Wallsgrove, Coventry, England, assignors to Courtaulds Limited, London, England, a British company No Drawing. Application June 29, 1951, Serial No. 234,454 Claims priority, application Great Britain August 4, 1950 equimolecular proportions of a dihydric phenol and a disulphonic ester of a diol in the presence of an alkali in a molecular proportion which is at least twice the molecular proportion of the disulphonic ester. The alkali is preferably a caustic alkali such 1-. as caustic soda. The molecular proportion of the alkali used must be at least twice the molecular proportion of the disulphonic ester but the presence of alkali in excess of this requirement is not detrimental as it has no efiect on the nature of the reaction. The reaction involved in the present invention using caustic soda as the alkali is believed to proceed on the following lines: + NaOH giving a polymer having the recurring unit together with R-SOz-O-Na and H20. In these formulae Ar is an arylene group, which may be substituted, R is a divalent linkage group and R is a monovalent hydrocarbon radical such as an alkyl, aryl or aralkyl group. R, may be, for example, a group of the type -(CI-i2)n in which m is an integer not less than 2, preferably from 2 to 10, a group of the type in which n is an integer not less than 2, or a group of the type in which is an integer not less than 2. The preferred dihydric phenol is hydroquinone but other dihydric phenols such as resorcinol and 3,3- or 4,4dihydroxy diphenyl may be used. Examples of suitable disulphonic esters are the di-para-toluene sulphonates of ethylene glycol, 1:4-bis-(p-hydroxyethoxy) benzene, propane- 1,3-diol, butane 1,4 diol, pentane 1,5 diol, hexane-1,6-diol, decane-1,l0-diol and diethylene glycol. Using hydroquinone and the di-paratoluene sulphonate of either ethylene glycol, or 1 4-bis- (,o-hydroxyethoxy) -benzene, the polymer in both cases is believed to have the recurring i.- 2 l L. 2 J The reaction according to the invention may conveniently be efiected by heating the reactants together under a reflux condenser in the presence of a diluent such as a mixture of water and dioxane. The reaction may also be carried out in the presence of an inert gas such as nitrogen to prevent as far as possible oxidative side reactions of the reactants and the product. The invention is illustrated by the following examples in which parts are by weight. Example 1 A mixture of 18.5 parts of the di-para-toluene sulphonate of ethylene glycol 01136-802-0-CHz-CH2-O-8O2-OCH3) 5.5 parts of hydroquinone, 30 parts of dioxane, 20 parts of Water and 4 parts of caustic soda was refluxed for 12 hours; during the heating the polymeric etherseparated out as a line white powder. This powder was separated, washed with boiling water and boiling dilute hydrochloric acid and dried at centigrade. The product was a white powder melting in the temperature range of 240 to 270 centigrade. It was insoluble in the usual organic solvents but dissolved in hot meta-cresol and hot nitrobenzene, partially crystallising out again on cooling. Intrinsic viscosity measurements on the filtered cold meta-cresol solution gave a minimum intrinsic viscosity of 9.29, 3 Example 2 A mixture of 20.24 parts of the di-para-toluene sulphonate of 1 z l-bis-(hydroxyethoxy) benzene 4 quinone, 96 parts of dioxane, 58 parts of water and parts of caustic soda was heated under a reflux condenser for 12 hours with vigorous stirring, a stream of nitrogen being maintained 4.4 parts of hydroquinone, 50 parts of dioxane, parts of water and 6.4 parts of caustic soda (twice the theoretical quantity), was heated at 100 centigrade under a reflux condenser for 23 hours; the mixture was stirred vigorously throughout while a stream of nitrogen was continuously passed through the apparatus both before and during the heating. The product was separated and purified as described in Example 1. The product was similar to that obtained in Example 1 and had a minimum intrinsic viscosity of 0.24. Example 3 A mixture of 50.6 parts of the di-para-toluene sulphonate of IA-bis-(hydroxyethoxy) -benzene, 11 parts of hydroquinone, 160 parts of dioxane, 58 parts of Water and 10 parts of caustic soda (25 per cent excess over the theoretical quantity) were heated under a reflux condenser for 20 hours. The heating was efiected under nitrogen as described in Example 2 and the product was separated and purified as described in Example 1. The product was a pale buff-coloured, fibreforming polymer melting in the range of 240 to 270 centigrade. Example 4 A mixture of 11.88 parts of butane ize-diol dipara-toluene sulphonate, 3.23 parts of hydroquinone, parts of dioxane, 25 parts of water and 3.58 parts of caustic soda was heated under reflux for 16 hours. The heating was effected under nitrogen as described in Example 2 and the product, a pale brown polymer, was separated and purified as described in Example 1. Example 5 A mixture of 38.4 parts of propane-1:3-dioldi-para-toluene sulphonate, 11 parts of hydroquinone, 96'parts oi dioxane, 58 parts of water and 10 parts of caustic soda (25 per cent excess) were heated under a reflux condenser for 12 hours with vigorous stirring, a stream of nitrogen being maintained through the reaction vessel as described in Example 2. The polymeric ether separated as a fawn-coloured powder during the heating. After cooling it was separated, washed with boiling water and boiling dilute hydrochloric acid and dried at centigrade. The product was a fawn-coloured powder, melting at to 168 centigrade; its intrinsic viscosity was 0.15. Example 7 A mixture of 41 .2 parts of pentane-l :5-diol-di-' para-toluene sulphonate, 11 parts of hydrothrough the reaction vessel as described in Example 2. The polyrneric ether was separated and purified as described in Example 6. The product was a fawn-coloured powder melting at 134 to 164 centigrade; its intrinsic viscosity was 6.17. Example 8 A mixture of 4-2.6 parts ofhexane-lzS-diol-dipara-toluene sulphonate, 11 parts of hydroquinone, 96 parts of dioxane, 58 parts of water and 10 parts of caustic soda (25 per cent excess) was heated under a reflux condenser for 12 hours with vigorous stirring, a stream of nitrogen being; maintained through the reaction vessel as described in Example 2. The polymeric ether was separated and purified as described in Example 6. The product was a pale fawn-coloured powder, melting at 165 to centigrade; its intrinsic viscosity was 0.18. Example 9 A mixture of 1 1.48 parts of decane-ltlO-dioldi-para-toluene sulphonate, 3.3 parts of hydroquinone, 58 parts of ioxane, 18 parts of water and 3 parts of caustic soda (25 per cent excess) was heated under a reflux condenser for 12 hours with vig- :ous stirring, a stream of nitrogen being maintained through the reaction vessel as described in Example 2. The polymeric ether was separated and purified as described in Example 6. The product was a brown solid, melting below 100 centigrade. In the above examples, intrinsic viscosity m is determined by the formula where 51 is the time for a solution of the polymer in ineta-cresol (concentration 0 grams in 100 grams of meta-cresol) using a standard Ostwald viscometer, and IE2 is the corresponding time for ineta-cresol alone. What we claim is: 1. A process for the production of linear polycthers which comprises mixing together to form a solution, substantially equimolecular proportions of a dihydric phenol which apart from its hydroxyl groups is unsubstituted, and an arcmatic disulphonic ester of a diol having the general formula HO-(CH2)mOH, in which 11:. is an integer not less than 2, together with an aqueous diluent and a caustic alkali, the molecular proportion of which is at least twice the molecular proportion of the disulphonie ester, heating the solution so formed at the refluxing temperature of the aqueous diluent; whereby a linear polyether is precipitated. and separating the polymeric ether so precipitated. 2. A process as claimed in claim 1, wherein the dihydric phenol used is hydroquinone. 3. A process as claimed in claim 1, wherein the disulphonic ester used is, the di-para toluene sulphonate of ethylene glycol. 4. A process as claimed in claim 1, wherein the aqueous diluent used'is a mixture of water and dioxane. 5. A process for the production of linear polyethers which comprises mixing together to form a solution, substantially equimolecular proportions of hydroquinone and the di-para-toluene sulphonate of ethylene glycol, together with aqueous dioxane as diluent, and a caustic alkali, the molecular proportion of which is at least twice the molecular proportion of the di-paratoluene sulphonate of ethylene glycol, heating the solution so formed at the refluxing temperature of the aqueous dioxane; whereby a linear polyether is precipitated, and separating the polymeric ether so precipitated. 6 References Cited in the file of this patent UNITED STATES PATENTS Name Date Arvin Nov. 10, 1936 OTHER REFERENCES Number 10 York. 1. A PROCESS FOR THE PRODUCTION OF LINEAR POLYETHERS WHICH COMPRISES MIXING TOGETHER TO FORM A SOLUTION, SUBSTANTIALLY EQUIMOLECULAR PROPORTIONS OF A DIHYDRIC PHENOL WHICH APART FROM ITS HYDROXYL GROUPS IS UNSUBSTITUTED, AND AN AROMATIC DISULPHONIC ESTER OF A DIOL HAVING THE GENERAL FORMULA HO-(CH2) M-OH, IN WHICH M IS AN INTEGER NOT LESS THAN 2, TOGETHER WITH AN AQUEOUS DILUENT AND A CAUSTIC ALKALI THE MOLECULAR PROPORTION OF WHICH IS AT LEAST TWICE THE MOLECULAR PROPORTION OF THE DISULPHONIC ESTER, HEATING THE SOLUTION SO FORMED AT THE REFLUXING TEMPERATURE OF THE AQUEOUS DILUENT; WHEREBY A LINEAR POLYETHER IS PRECIPITATED AND SEPARATING THE POLYMERIC ETHER SO PRECIPITATED.

1951-06-29

en

1954-06-08

US-12659187-A

Articulating steel cap for underground mining support structures ABSTRACT A steel cap for steel sets in mining support structures is made of a hollow sectional profile having a certain length. A tip is arranged as an insert at one end of the sectional profile. A fork is arranged as an insert at the other end of the sectional profile. Each insert is formed as a plug-in connection. The plug-in connection is provided with a hold free of play in a correct position. For this purpose each insert has at its end facing the sectional profile, a plug with a cross-section corresponding to that of the sectional profile, and at least one surface inclined relative to the longitudinal axis of the steel cap. At least one movable wedge element is arranged for cooperation with each inclined surface. A wedge drive permits driving the wedge element or elements into or out of a locking position relative to the respective inclined surface. FIELD OF THE INVENTION The invention relates to an articulating steel cap for underground mining support structures made of a section of a hollow sectional profile of given length. A tip is inserted into one end of the hollow section. A fork is inserted into the other end of the hollow section. The tip and fork each have an insert, whereby the connection of each insert to the hollow section is constructed as a plug-in connection. DESCRIPTION OF THE PRIOR ART Such an articulating steel cap is already known from German Utility Model Number 83 05 874. Steel caps of this type can be manufactured at reasonable costs and the maintenance and repair can be performed efficiently. The cap components can be assembled easily on location in a mine. However, the manufacturing methods for making such a cap must meet relatively high requirements, for example, tolerance requirements. Yet, it is not possible, at reasonable costs, to insert the respective tip or fork into the hollow section completely without ply so that on the one hand so-called fretting corrosion may occur while on the other hand an undesirable edge pressure can occur. OBJECTS OF THE INVENTION In view of the foregoing it is the object of the invention to further develop an aritculating steel cap of the above type in such a way, that the inserts are provided with a play-free safe hold in a correct position without losing the described advantages and to avoid fretting corrosion and edge pressures. SUMMARY OF THE INVENTION According to the invention this object has been achieved by an insert having at its end facing toward the hollow section a profiled plug having a cross-section corresponding to the cross-section of the hollow section. Each profiled plug has at least one longitudinally inclined surface. A movable wedge element is arranged for cooperation with each longitudinally inclined surface. The wedge element is constructed to be pulled into the hollow sectional profile between the longitudinally inclined surface and an inner surface of the hollow section. Due to the use of inclined surfaces in combination with wedge elements it is possible to assure an absolutely safe hold of the respective insert with its plug in a correct position in the hollow section. An especially good hold is achieved if not only one inclined surface, but rather two corresponding surfaces arranged opposite each other are used in combination with two wedge elements. Advantageously such surfaces both have the same inclination, whereby, in combination with the corresponding wedges, the respective insert is centered in the hollow section. The connection is thus very safe, yet simultaneously easily releasable. The assembly advantages mentioned above are retained. The efficiency in the repair and maintenance known from the above described prior art, is also maintained. The connection is no longer sensitive to fretting. The undesirable edge pressing and the erroneous positioning of the respective insert caused by the edge pressing are avoided. According to an embodiment of the invention at least one pull-anchor extending in the longitudinal direction is arranged inside the insert. The pull-anchor reaches behind each movable wedge element by means of a back-grip. The pull-anchor is constructed for external activation. Such a structure is very simple and provides external access to the pull-anchor for driving the wedges with the required force into a locking position, or to loosen the wedges. Preferably, the pull-anchor is constructed as a threaded bolt having a bolt head accessible from the outside and a threaded portion carrying a nut forming said back-grip which is guided for axial movement in the hollow section, but held against rotation. The threaded bolt is easily operable thorough its outwardly freely accessible bolt head. The bolt threading, cooperating with the nut functioning as a back-grip, provides a very large force translation or mechanical advantage so that if necessary the wedges may be pulled in with a very large force. There is a direct force transmission between the wedge and the insert through the pull-anchor. Hence, any undesired displacement of the wedge element due to tensioning or clamping forces caused by the clamping operation, is not to be expected. The nut of the pull-anchor has an outer cross-sectional configuration adapted, with play, to the inner cross-section of the hollow section. The nut cross-section is preferably rectangular, or approximately rectangular, or it may have a quadrangle form. If the outer cross-sectional shape of the nut corresponds, with play, to the inner cross-section of the hollow section, the nut can on the one hand not rotate, but on the other hand it can move axially without any hindrance for operating the wedge element or elements. According to the invention, each wedge element is connected to the back-grip or nut so that the wedge element can move radially relative to the back-grip or nut without being able to move axially without axial movement of the nut. This feature has the advantage that through the pull-anchor, which is, for example, constructed as a threaded bolt, the wedge element or elements can be simply driven out of their clamping position, from the outside, for loosening the connection between the hollow section and the insert. For this purpose the threaded bolt is pressed or punched inwardly in an axial direction to thereby take along the nut which in turn entrains the wedge element or elements axially thereby loosening the connection. The invention also provides that the insert constructed as a fork, is longitudinally divided centrally in a plane parallel to the fork surfaces. A longitudinal division of the fork is possible without losing the securing strength or safety of the fork. Dividing the fork provides simultaneously a more cost efficient production and repair of such a fork because in case of damage only one half of the fork is damaged while the other half remains usable. Thus, it is possible in case of damage to exchange but one half of the fork. As result, the stock maintenance is substantially reduced anD a smaller weight needs to be transported when repairs are necessary. If the fork is divided, it is possible to provide a separate wedge for each inclined surface of the profiled plug of the fork half. Due to this feature possibly the smallest dimensional tolerances between the inclined surfaces of the two cooperating fork halves may be compensated. This division of the wedges to be used is within the scope of the invention. It is also possible to incline all plane surfaces of the profiled plugs of the divided fork as well as of the undivided fork and of the tip and to allocate wedges to these inclined surfaces. Thus, a very rigid fixation can be achieved in all directions. However, especially the inclined surfaces of the profiled plugs which apply the main force to the respective wedge and thus transmit this force to the hollow section should be covered as much as possible by the wedges for reducing surface pressure during the force transmission. According to the invention the angle of inclination of the inclined surfaces is within the range of 2° to 10°, whereby a very strong connection is achieved even with relatively small pulling-in forces. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein: FIG. 1 is a longitudinal section through a cap of the invention including a hollow steel section, a tip inserted into one hollow end and a fork inserted into the other hollow end of the steel section; FIG. 2 shows the present cap of FIG. 1 with the tip and cap pulled out; FIG. 3 is an exploded side view of the pull-anchor, the wedge elements, and the back-grip member or nut; FIG. 4 is a section along section line IV--IV in FIG. 2; FIG. 5 is a section along section line V--V in FIG. 1; FIG. 6 is a section along section line VI--VI in FIG. 2; and FIG. 7 is a view in the direction of the arrow A in FIG. 2 rotated to the left by 90°. DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BEST MODE OF THE INVENTION FIG. 1 shows a side view, partially in section, of an articulating steel cap 1. The central member 2 of the cap 1 is constructed as an integral box profile or section that may be cut from a length of hollow sectional steel. A tip 3 is provided at one end of the hollow box section 2 and a fork 4 is provided at the other end of the hollow box section 2. The tip 3 has a profiled insert plug 5. The fork has a profiled insert plug 6. In the illustrated arrangement, the line of effectiveness of the main load direction is located in the plane of the drawing or parallel thereto. The profiled insert plug 5 of the tip comprises, perpendicularly to the plane of the drawing, and in an opposed arrangement, two surfaces 7 and 8 inclined in the longitudinal direction so as to converge inwardly relative to the hollow box section 2. Each of these surfaces 7 and 8 has an angle of inclination alpha in the range of about 2° to 10°. The plug 5 may have additional wall members or lateral surfaces extending parallel to the plane of the drawing. These additional wall members or lateral surfaces have such a spacing from one another, that they fit with as little play as possible into the respective hollow space of the hollow box section 2. Such a surface arrangement is known from the above described prior art. The additional wall members are not absolutely necessary, however, they may be advantageous since they may contribute substantially to the stiffness of the entire system. It is also conceivable that these additional wall members have a corresponding inclination as, for example, the longitudinally inclined surfaces 7 and 8. The facing ends of at least the longitudinally inclined surfaces 7 and 8 may bear mutually against a wall member or bottom 23 having an opening 24. The walls having the surfaces 7, 8 and the bottom 23 preferably form an integral plug. These wall members forming the longitudinally inclined surfaces 7 and 8 must be sufficiently supported relative to each other. The profiled insert plug 6 of the fork 4 is constructed substantially similarly as the plug 5 with longitudinally inclined surfaces 9 and 10. The longitudinally inclined surfaces 9 and 10 also have the inclination angle alpha of about 2° to 10° and they converge inwardly into the hollow box section 2. The plug 6, however, shows a modification of an example embodiment. Namely, the longitudinally inclined surfaces 9 and 10 are supported exclusively by the wall members 25 and 26 so that at the facing side or end a natural opening 27 remains. The respective cross-sectional shapes of the hollow box section 2 and of the inserts 3 and 4 are shown in FIGS. 4 to 6. FIG. 4 is a view onto the plug 5 of the tip 3 prior to inserting the plug 5 into the hollow box setion 2. FIG. 5 shows the tip 3 inserted with its plug 5 into the box section 2 whereby the nut 18 and the threaded end of the pull-anchor 17 are visible. FIG. 6 shows a view onto the plug 6 of the fork 4 prior to inserting the plug 6 into the box section 2. For securing the inserts 3 and 4, for example, the threaded bolt 17 forming a pull-anchor is inserted in the longitudinal direction into the insert 3. For this purpose the threaded bolt 17 is passed through the opening 28 and through the opening 24 until the bolt head 19 comes to rest on the shoulder 28'. The nut 18 is now screwed onto the threaded part of the threaded bolt 17. The nut 18 is left in a rotated position which permits the insertion of the nut 18 into the hollow box section 2. The cross-section of the nut 18 corresponds, with sufficient play, to the inner cross-section of the hollow box section 2 so that the nut 18 inserted into the box section 2 cannot rotate any more. Two movable wedge elements 11 and 12 placed to rest with their inclined surfaces on the respective inclined surfaces 7 and 8 of the profiled insert plug 5, bear axially against the nut 18. The wedge elements are connected with the nut 18 in any desired manner in such a way that they can at least move slightly radially. An axial movement of the nut 18 in both directions shall entrain the movable wedge elements 11 and 12 so that these wedge elements 11 and 12 may be locked or loosened. The sequence of assembly of the pull-anchor device, however, without the insert tip 3, is shown in an exploded view in FIG. 3. When the device is assembled, the insert tip 3 may be pushed with its profiled insert plug 5 axially into the hollow box section 2 until the facing end 29 of the insert 3 bears against the respective facing edge of the hollow box section 2. When this condition is achieved, the bolt head 19 of the threaded bolt 17 acting as a pull-anchor, is rotated. Since the nut 18 cannot rotate inside the hollow box section 2, it travels in the axial direction toward the bolt head 19, thereby pushing the movable wedge elements 11 and 12 in the axial direction so that the wedge gap between the inclined surfaces 7 and 8 of the profiled insert plug 5 on the one hand and the respective inner surfaces of the hollow box section 2 on the other hand is completely filled, whereby the wedge elements are in a locking position. The movable wedge elements 11 and 12 can thus be pulled with a very large force into the wedge gap, whereby an extraordinarily strong connection is established, which simultaneously centers the insert tip 3 in the correct position in the box section 2. Preferably, the width of the movable wedge elements 11 and 12 is so dimensioned that they cover the respective width of the longitudinally inclined surfaces 7 and 8 as much as possible in order to achieve a surface pressure as small as possible in spite of high clamping forces. The same applies naturally to the movable wedge elements 13 and 14 in their arrangement and relationship to the longitudinally inclined surfaces 9 and 10 of the profiled insert plug 6. The wedge elements 13, 14 are assembled and used in the same manner as described above with reference to the profiled insert plug 5. The described manner of attaching the insert tip 3 and insert fork 4 according to the invention in the hollow box section 2 for forming an articulating steel cap 1, makes it advantageously possible to divide the fork 4 in the plane 21 parallel to the fork surfaces 22. The dividing plane 21 is indicated in FIGS. 4 and 7. The division of the fork 4 on the one hand has the advantage that the respective individually forged half fork sections are simpler and hence more cost efficiently produceable so that the fork 4 assembled of these half fork sections is cheaper than forks which are produced as integral members by conventional methods. On the other hand, such as divided fork 4 can be repaired more efficiently than heretofore because in case of damage normally only one half of a fork 4 is damaged. If the fork 4 is a single integral piece, the entire fork becomes useless and must be replaced. However, in the case of a divided fork, only the damaged half becomes useless and can be replaced by a respectively less expensive new half fork. Since half of the fork is naturally also substantially lighter than an entire fork, the repair work is respectively simplified. Further, the stock supplies may be reduced by this feature, especially the stock supplies directly in the mine. In the case of the divided fork it may be advantageous to also divide the longitudinally movable wedge elements 13 and 14 in the longitudinal direction so that also small differences in the inclination of the longitudinally inclined surfaces 9 and 10 may be compensated. These inclined surfaces 9 and 10 are now allocated each to its fork half. However, when the longitudinally inclined surfaces 9 and 10 are corresponding to each other with a sufficient precision, such feature is not necessary. Due to the pull-in, the outer not inclined surfaces of the movable wedge elements 11 to 14 come to rest rigidly against the inner surfaces 15 or 16 of the hollow box section 2 so that in the axial direction a very strong force-locking or clamping is produced while in the radial direction a form-locking connection with the hollow profile section 2 is provided. With this type of connection the advantages of an articulating steel cap having a welded-on tip and fork, are achieved without the serious disadvantages. Rather, according to the invention it is possible to combine the advantages of the known welded steel cap with the advantages of the known plug-in steel cap and simultaneously eliminate the disadvantages of both systems. Additionally, the invention has the following advantages. It provides th possibility of selecting the material for making the cap. It reduces the stock maintenance and thus assures smaller stock maintenance costs than in the prior art. The tools needed for assembling the present caps are simple and relatively coarse tools readily available in a mine. Additionally, the present caps have a smaller weight than heretofore. These features, for the first time, make it possible to use the present caps in developing countries where mining operations take place. The caps are especially advantageous for these countries because heretofore the mining support structures were mainly made of wooden timbers in these countries with the result that forests become denuded with dangerous ecologic consequences. Additionally, in the long run the present steel caps are more economical than the conventional wooden timber support structures. Although the invention has been described with reference to specific example embodiments it will be appreciated, that it is intended to cover all modifications and equivalents within the scope of the appended claims. What I claim is: 1. An articulating steel cap for mining support structures, comprising a hollow box section having a given inner cross-sectional shape, a cap tip at one end of said hollow box section, a cap fork at the other end of said hollow box section, plug-in connection means for securing said cap tip and said cap fork to said hollow box section, said plug-in connection means comprising a profiled plug (5, 6) rigidly connected to said cap tip and to said cap fork, each profiled plug having a cross-section corresponding to said given inner cross-sectional shape of said hollow box section, each profiled plug having wall members with at least one longitudinally inclined surface (7-10), a movable wedge element (11-14) arranged for cooperation with the respective longitudinally inclined surface, and means for pulling each wedge element into a space between said longitudinally inclined surface (7-10) and an inner surface (15, 16) of said hollow box section for wedging said profiled plugs into a locking position and for also moving said plugs into a release position. 2. The articulating steel cap of claim 1, wherein said pulling means comprise a pull-anchor (17) arranged to extend longitudinally through its respective cap tip and profiled plug and its respective cap fork and profiled plug, said pull-anchor having a back-grip (18) reaching behind each movable wedge element (11-14), said cap tip and cap fork having access holes for an external operation of said pull-anchors. 3. The articulating steel cap of claim 2, wherein said pull-anchor comprises a threaded bolt (17) having an externally accessible bolt head (19) and a threaded portion, a nut (18) on said threaded portion, said nut forming said back-grip which is guided for axial movement inside said given inner cross-sectional shape of said hollow box section, but prevented from rotating inside said hollow box section. 4. The articulating steel cap of claim 3, wherein said nut (18) has an outer cross-sectional shape adapted to said given inner cross-sectional shape of said hollow box section. 5. The articulating steel cap of claim 2, wherein each wedge element (11-14) is connected to said back-grip (18) for radial movement relative to said back-grip and for axial movement only with said back-grip (18). 6. The articulating steel cap of claim 1, wherein said cap fork (4) is centrally divided longitudinally in a plane (21) parallel to fork surfaces (22). 7. The articulating steel cap of claim 1, wherein said inclined surfaces (7-10) have an angle of inclination within the range of about 2° to about 10°.

1987-11-30

en

1989-04-11

US-1139293-A

Voltage controlled integrated circuit for biasing an RF device ABSTRACT The present invention is directed to a voltage controlled single-package integrated circuit device, capable of thermal compensation, for biasing a quasi-linear bipolar device. The bias circuit also provides a low impedance source to a RF device so that the bias point does not dynamically change with the RF signal, thus improving linearity. Changes in the base-emitter voltage level of the RF device are monitored by a reference diode to provide automatic temperature compensation. The reference diode is in close thermal proximity to the RF device, allowing for accurate thermal tracking. The base-emitter voltage may be electronically adjusted by means of a control voltage input, such being suitable for hook-up to a computer system having a digital to analog convertor thereby allowing for fine voltage adjustments. The control voltage may also be used to adjust the class of operation of the RF device or provide external temperature control. CROSS REFERENCE TO RELATED APPLICATIONS The subject matter of the present application is related to co-pending U.S. application, Ser. No. 07/932,755, titled "Device for Biasing an RF Device Operating in Quasi-Linear Modes with Temperature Compensation", filed on Aug. 20, 1992 and assigned to the assignee hereof, and herein incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an integrated circuit for biasing a quasi-linear bipolar device, and more specifically to a voltage controlled single-package integrated circuit device capable of thermal compensation for biasing such a device. 2. Description of the Prior Art It is well-known in the art that biasing circuitry is required for quasi-linear devices such as bipolar RF transistors. Quasi-linear devices are characterized as being in the common-emitter configuration with a conduction angle of 180 degrees to 360 degrees. The biasing circuitry must supply the proper current levels required by the device while compensating for drifts in the device operating point brought about by changes in ambient temperature and operating conditions. Systems which are not protected from temperature fluctuations are more susceptible to ambient temperature changes and system heat-sinking properties which are not optimal. If operating point drift is not addressed and remedied, catastrophic device failure, or "thermal runaway" may result. Because of this potential danger caused by thermal variations, biasing circuitry has long monitored and compensated for fluctuations in temperature. Typically, the base-emitter voltage level of the RF device being biased is monitored and, when increases in temperature cause the voltage level to drop, the voltage is stabilized by decreasing the amount of current in the RF circuit. However, biasing circuitry of the prior art has usually included multiple active components, capacitors, and inductors, on a PCB. Since these components are usually fabricated by different suppliers, the RF characteristics of the active devices typically have different geometries and, thus, often do not exactly match the characteristics of the RF device being biased. In addition, the use of discrete components utilizes more valuable board space than would a biasing circuit on a single integrated circuit. This is very important in today's market of high performance, low cost, small RF power hybrid modules. Besides thermal tracking of the biased device, another important concern is the ability to change class of operation as system demands dictate. Typical quasi-linear modes of operation include classes A, AB1, AB2, and B. It may be desirable to change a system's mode of operation to any one of these. For example, if more efficiency and less linearity of operation is required, it may make sense to change class of operation from class AB1 to AB2. The class of operation of an RF device is typically altered by varying the voltage supplied to the device. However, the prior art has not successfully addressed this need with a single-package integrated circuit device. SUMMARY OF THE INVENTION It is therefore an object of this invention to utilize biasing circuitry which monitors and compensates for changes in the operating point of a quasi-linear device caused by fluctuations in temperature or operating point. It is further an object of this invention to utilize biasing circuitry capable of changing the class of operation of a quasi-linear device. The present invention is directed to a voltage controlled single-package integrated circuit device, capable of thermal compensation, for biasing a quasi-linear bipolar device. The bias circuit also provides a low impedance source to a RF device so that the bias point does not dynamically change with the RF signal, thus improving linearity. Changes in the base-emitter voltage level of the RF device are monitored by a reference diode to provide automatic temperature compensation. The reference diode is in close thermal proximity to the RF device, allowing for accurate thermal tracking. The base-emitter voltage may be electronically adjusted by means of a control voltage input, such being suitable for hook-up to a computer system having a digital to analog convertor thereby allowing for fine voltage adjustments. The control voltage may also be used to adjust the class of operation of the RF device or provide external temperature control. BRIEF DESCRIPTION OF THE DRAWINGS The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, and further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: FIG. 1 is a schematic of a biasing circuit for an RF device according to the prior art; and FIG. 2 is a schematic of a biasing circuit for an RF device according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a schematic of a biasing circuit 10 for an RF device according to the prior art. Comprised of discrete components, both passive and active, biasing circuit 10, as indicated by the dashed lines, is contained on a PCB and therefore does not reside in a single-package integrated circuit device. Reference diode DREF, which is thermally coupled to the RF device, monitors the base-emitter voltage with respect to ambient temperature changes of the RF transistor being biased. An increase of 1 degree Celsius, yields a PN junction voltage decrease of 2 to 2.5 millivolts. As the ambient temperature increases, the PN junction voltage drops, causing the operating point of the device to drift. If this phenomenon is not stabilized, thermal runaway may be the result. When a base-emitter voltage drop is detected via temperature by reference diode DREF, bias circuitry 10 compensates by supplying less voltage to the RF device. This compensation is accomplished by discrete components capacitor C1, zener diode D1, resistor R3, comparator X2, and reference diode DREF. VCNTL is a voltage input to bias circuit 10, whereby the voltage supplied to the RF device may be controlled. OUT is the voltage signal to be fed to the base of the biased RF device. Many different biasing circuits could be used to accomplish what is shown in FIG. 1. However, it is important to recognize that this prior art is not a single package integrated circuit solution. Because the biasing circuit 10 is comprised of discrete components, both passive and active, board space is used and mismatch of RF characteristics between these discrete components and the RF device being biased is experienced. Referring now to FIG. 2, a schematic of a biasing circuit 20 for an RF device according to the present invention is shown. The components of biasing circuit 20, contained within the dashed lines, are contained in a single-package integrated circuit. Active components L1 and C1 provide RF decoupling to bias circuit 20. VCC, the supply voltage, is a standard supply voltage similar to that used by many bipolar RF devices today. DREF, the reference diode, is placed in close thermal proximity to the RF device being tested--in this case, T5 --and monitors the junction temperature of T5 and thus the drift in the base-emitter voltage of T5 with respect to ambient temperature changes. Since reference diode DREF is thermally connected to biased device T5, biasing circuit 20 will track T5 's base voltage in response to temperature changes in T5, and maintain a constant quiescent collector current. Thus, class of operation and performance are maintained. For maximum thermal tracking, it is important that reference diode DREF be placed in thermal proximity to biased device T5. Since biasing circuit 20 is a single integrated circuit, close placement of DREF to T5 is facilitated. As biased device T5 heats up, reference diode DREF senses this temperature change and bias circuit 20 adjusts the voltage value at voltage V1 accordingly. A change in voltage V1 is mirrored by a corresponding change in base-emitter voltage V' such that the collector current of the biased device IC remains constant. It will be understood by those familiar with the art, that the value of resistor R5 is relatively small and is chosen to establish VCNTL at V1 while allowing any decrease in the value of the PN junction voltage of T5 to also be reflected at V1. The feedback loop which adjusts base-emitter voltage V1 in response to changes in temperature is composed of differential pair T1 and T2 and Darlington pair T3 and T4. T1 and T2, with their emitters decoupled from ground via small resistor R2, form a differential pair. It is advantageous for differential pair T1 and T2 to have closely matched characteristics so that they are balanced. When transistors T1 and T2 are made from the same die, as is the case here, matching is facilitated. Since V2 is usually a constant value, R2 represents a constant current source. Current which flows through R2 is shared by T1 and T2. If VCNTL is increased, T1 turns on more, thereby providing less current to T2 and more current for Darlington Pair T3 and T4, causing V2 to increase. Darlington pair T3 and T4 provide bias circuit 20 with a low impedance current source as required by ideal voltage source V', and therefore serves to pass through current needed to maintain emitter-base voltage V' at a stable level independent of the current needs of biased device T5. Darlington pair T3 and T4 are especially attractive because of the extra current gain they offer. They provide increased sensitivity for a more stable output voltage and a lower output impedance than would otherwise be achieved. Resistor R4 is used to provide a current sink option for bleeding excess charge; in this way, bias circuit 20 can both source and sink current thereby eliminating the need to rely on T5 to sink current. The physical size of Darlington transistors T3 and T4 can be increased so that they are capable of passing more current. If this increase in size is implemented, differential pair T1 and T2 may also need to be larger in order to withstand the larger current which will flow through R1. And, while T3 and T4 offer excellent current gain characteristics, they could be replaced by other circuitry, such as a single-pass transistor, if less current gain is acceptable. The presence of transistor T1 allows emitter-base voltage V' to be electronically controlled. Control voltage input VCNTL provides the means by which the user may adjust V' as required. Changing VCNTL also allows the class of operation of the biased device to be changed. For instance, hooking up control voltage input VCNTL to a computer which possesses a digital to analog convertor would allow frequent and minute adjustments to be made to VCNTL, thereby changing the voltage at the base of T1 and, in turn, the value of base-emitter voltage V'. As described above, when base-emitter voltage V' is changed, the collector current IC of biased device T5 also changes, allowing its class of operation to be changed. Biased device T5 may be operating in the Class AB1 mode if a linear range of operation is desired. Changing the value of VCNTL can push biased device T5 into a Class AB2 mode of operation which may be desirable if greater efficiency and a smaller linear range of operation is required. Changing the class of operation of biased device T5 is accomplished by simply varying the voltage level of VCNTL and does not require changing any components in biasing circuit 20. This advantage differentiates the invention over the prior art. An improved structure for biasing devices has been described. Any bipolar device operating in the quasi-linear mode where thermal runaway is an issue and where it might be advantageous to change the class of operation during operation stands to benefit from the invention described herein. While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. For instance, reference diode DREF is described as the means by which the junction temperature of biased device T5 is monitored. However, one skilled in the art will understand that other semiconductor temperature sensing devices, such as a transistor, may be used. Additionally, an active current source, rather than resistor R2, could be used to decouple the emitters of differential pair T1 and T2 to ground. What is claimed is: 1. A single package integrated circuit device for biasing a quasi-linear bipolar device having a class of operation, comprising:a reference device for monitoring temperature changes of the quasi-linear bipolar device and for monitoring any corresponding deviations of a base-emitter voltage of the quasi-linear bipolar device from a predetermined base-emitter voltage level; a feedback loop for maintaining the predetermined base-emitter voltage level of the quasi-linear bipolar device comprising a differential transistor pair, having a first transistor and a second transistor wherein a emitter of the first transistor and an emitter of the second transistor are connected, and a Darlington transistor pair, having a third transistor and a fourth transistor, with a base of the third transistor connected to a collector of the second transistor, a base of the fourth transistor connected to an emitter of the third transistor, and a collector of the third transistor connected to a collector of the fourth transistor, wherein the Darlington transistor pair provide a low impedance current source required to maintain the predetermined base-emitter voltage level of the quasi-linear bipolar device; a voltage control input, for selectively electronically adjusting the predetermined base-emitter voltage level of the quasi-linear bipolar device thus changing the class of operation of the quasi-linear bipolar device, connected to a base of the first transistor. 2. The biasing device of claim 1, wherein the voltage control input is suitable for control by a computer such that frequent and small changes in the predetermined base-emitter voltage level may be realized. 3. The biasing device of claim 1, wherein the class of operation refers to classes A, AB1, AB2, and B. 4. The biasing device of claim 1, wherein the reference device is in close thermal proximity to the quasi-linear bipolar device. 5. The biasing device of claim 4, wherein the reference device is a diode. 6. The biasing device of claim 1, wherein the emitter of the first transistor and the emitter of the second transistor are decoupled from ground through a small resistance. 7. The biasing device of claim 6, wherein the small resistance is a resistor having a current, wherein the resistor behaves as a constant current source and the current through the resistor is shared between the first transistor and the second transistor. 8. The biasing device of claim 1, wherein the collector of the third transistor and the collector of the fourth transistor are connected to a power supply. 9. The biasing device of claim 1, wherein a resistive element supplies current from a power supply to the base of the third transistor. 10. The biasing device of claim 9, wherein the resistive element is a resistor. 11. The biasing device of claim 1, wherein the quasi-linear bipolar device is a bipolar RF transistor.

1993-01-29

en

1994-09-06

US-59283084-A

Compressor auxiliary condenser arrangement adapted to be mounted in a refrigerator machinery compartment ABSTRACT A unitary refrigerator compressor and auxiliary condenser assembly adapted to be installed in the machinery compartment of a domestic refrigerator. The assembly includes a serpentine portion of the auxiliary condenser having an inlet and outlet end connected to the compressor, and a container supported on the serpentine portion for providing evaporation of water collected in the container. The serpentine portion of the condenser and container are in intimate heat exchange contact by virtue of adhesive bonding between the two components, and are resiliently supported on the base member so as to vibrate in unison with said compressor. BACKGROUND OF THE INVENTION The present invention relates generally to refrigerators of the type wherein the high-side portion of the refrigeration system is arranged in a machinery compartment which is isolated from the food storage compartment of the refrigerator, and more particularly to a unitary system including the compressor and auxiliary condenser arrangement which are resiliently mounted on a base member so as to vibrate in unison. In refrigerators using a natural convection condenser system, the condenser is usually mounted on the back wall of the refrigerator. Depending on the type compressor used it may be necessary to provide an auxiliary condenser for the purpose of providing oil cooling. This added volume of tubing must either be accommodated by placing it in the same area of the condenser in which case the condenser must be made taller or the refrigerator must be maintained a further distance from the wall on which it is to be arranged. In the alternative, the auxiliary condenser may be arranged in the machinery compartment as shown in U.S. Pat. No. 2,721,451 and U.S. Pat. No. 2,679,144, both assigned to the General Electrical Company, the assignee of the present invention. Some refrigerators include means for automatically defrosting the evaporator upon which frost forms and collects. Often such refrigerators also include means whereby moisture resulting from a defrosting operation is evaporated into the atmosphere outside the food storage compartments and thereby disposed of. One arrangement for so disposing of the defrost moisture as shown in the above referenced patents includes using the auxiliary condenser in the machinery compartment and a drain pan in heat exchange relationship with the auxiliary condenser. In this arrangement the defrost moisture is directed into the drain pan from the evaporator located in the food storage compartment and is evaporated by the heat from the auxiliary condenser. While this is a convenient and efficient way of evaporating moisture, it does present some problems in that the operating compressor vibrates relative to its mount. Since the auxiliary condenser is connected to the compressor through relatively rigid tubing, the vibrations from the compressor are transferred to the auxiliary condenser and pan structure. This results in excessive noise and further possible damage from metal fatigue can occur. SUMMARY OF THE INVENTION Accordingly, the present invention has as its primary objective means for mounting the compressor and auxiliary condenser assembly on the same support structure so that they will vibrate un unison. Another object of the invention is to provide an auxiliary condenser, condensate pan arrangement which is utilized for both evaporating defrost moisture and for cooling compressor oil, if desired. Another objective of the invention is to increase the heat exchange relationship between the auxiliary condenser and condensate pan so as to allow a high natural convective heat dissipation and defrost condensate evaporation in a minimum of space. Another object of the invention is to provide a lateral arrangement of the components in the rear portion of the cabinet so as to allow the front portion of the cabinet to be configured lower to the floor to thereby increase the capacity of the food storage compartment. A household refrigerator is provided including a cabinet having a compartment to be refrigerated in the upper portion thereof. The food compartment is separated by an insulated partition to include a machinery compartment in the lower portions of and adjacent the rear wall of the cabinet. The machinery compartment extends substantially between the side walls of the cabinet and has an access opening in the rear wall of the cabinet. A unitary refrigerating apparatus is adapted to be arranged in the machinery compartment through the access opening. The unitary apparatus includes a base member having a substantially horizontal support wall extending substantially between the side walls of the cabinet. Supported on the support wall is a hermetic compressor and an auxiliary condenser. The auxiliary condenser includes a serpentine tube portion disposed outside of the hermetic compressor which is connected to the compressor through the compressor outlet tube. A condensate collection container is disposed in heat exchange relation with the serpentine tube portion to form a condensate removal assembly. Means are provided for supporting the container and the serpentine tube portion on the support wall. The support means includes a bracket having leg portions mounted on the support wall and a platform portion spaced from the support wall dimensioned to receive the condensate removal assembly. Locking means are provided to securely hold the condensate removal assembly relative to the platform. Both the compressor and condensate removal assembly are resiliently mounted on the support wall. To this end the elastomer support means are disposed between the compressor and the support wall, and between the leg portions and the support wall for resiliently supporting the compressor and condensate removal assembly relative to the support wall so that the compressor and condensate removal assembly vibrate in unison. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevational view of a refrigerator incorporating the preferred embodiment of the present invention; FIG. 2 is an enlarged rear elevational view showing the arrangement of components incorporating the preferred embodiment of the invention; FIG. 3 is a section view taken above line 3--3 of FIG. 2; and FIG. 4 is an exploded perspective view of the components incorporating the preferred embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 is a partially illustrated a refrigerator cabinet 10 including a food storage compartment shown in outline and indicated by 12, and a machinery compartment 14 disposed below the food storage compartment. A door 16 hingedly mounted on the refrigerator cabinet 10 is provided for closing an access opening to the food storage compartment 12. Located in the compartment 12 is the refrigeration system evaporator 13 provided for cooling compartment 12. Referring now to FIGS. 2 and 3 there is shown located in the machinery compartment 14 is a refrigerating unit or compressor 18 mounted on a base member 19 which is adapted to be arranged in machinery compartment 14 through a rear access opening. The base member 19 extends substantially between the cabinet side walls and is secured to the cabinet 10 in any suitable manner such as by bracket 20 to front wall of compartment 14 and by bolts 22 to the rear wall of the cabinet. The compressor 18 is included in the refrigeration system provided for cooling the fresh food compartment. Also included in the refrigeration system and located in the machinery compartment 14 is an auxiliary condenser 24 which in operation assists the main condenser 26 in the system in dissipating heat absorbed by the system from the food storage compartment. During normal operation of the refrigeration system the absorption of heat from the food storage compartment 12 results in the formation of frost on the evaporator 13 located in compartment 12. The defrost system employed in the present embodiment is generally referred to in the art as a cycle defrost system. In a cycle defrost system the fresh food compartment 12 in which the evaporator 13 is located is maintained at a temperature generally above freezing. Each time the compressor 18 is de-energized or cycles off during normal operation of the refrigerator any frost which may accumulate on the evaporator 13 during the period of time the compressor 18 is operating will in effect melt off by natural convection of the warmer air within the fresh food compartment 12. This defrost water or moisture resulting from the defrosting of the evaporator when the compressor is de-energized is collected by a trough 15 and is conducted by a tube 28 to the machinery compartment 14. As seen in FIGS. 2-4 the above-mentioned auxiliary condenser 24 may comprise a single conduit arranged in serpentine form and including a plurality of passes 30 disposed in a common horizontal plane. Secured to the upper sides of the passes 30 as by high temperature hot melt adhesive 33 is a moisture collecting pan 32. In the present embodiment the pan 32 is fabricated from aluminum while the auxiliary condenser 24 may be of clad steel tubing. The use of a hot melt adhesive 33 along the entire length of the passes 30 provides both an effective bond between the dissimilar materials and an excellent heat exchange relationship therebetween. The effective heat exchange afforded between the condenser 24 and pan 32 by the use of a hot melt adhesive allows a minimum amount of tubing to be used which results in a machinery compartment which also utilizes a minimum amount of space in the refrigerator cabinet. It should also be noted that the adhesive used besides being self-curing should withstand temperature approaching 300° F. In the present embodiment the pan 32 is secured by adhesive in intimate heat exchange relationship with the auxiliary condenser 24 and accordingly the condensate collected in pan 32 is heated by relatively hot gaseous refrigerant flowing through the passes 30 of the auxiliary condenser 24. The auxiliary condenser 24 and pan 32 assembly which in effect forms a condensate removal assembly is mounted on the base member 19 and arranged spaced laterally therefrom to assure free circulation of air around the assembly. The auxiliary condenser and pan assembly includes a support member 34 which is formed to include a horizontal platform portion 36 on which the serpentine portion 30 of the auxiliary condenser 24 is arranged. Extending downwardly from this horizontal platfrom portion 36 are a pair of legs 38. The legs 38 include two outwardly and horizontally extending support portions 40 which are adapted to be supported on the base 19 in a manner to be explained hereinafter. Because the present refrigerator employs a cycle defrost system wherein defrosting of the evaporator takes place each time the compressor is de-energized or cycles off during the normal operating mode of the refrigerator, the pan 32 receives water intermittently and at rather low volumes. This insures that the moisture collected in the pan 32 during each off cycle of the compressor is completely evaporated by the relatively hot gaseous refrigerant circulating through the serpentine portions 30 of the auxiliary condenser 24 during each on cycle of the compressor. In the present embodiment of the invention the auxiliary condenser 24 is also employed as a compressor oil cooler. To this end as shown in FIG. 2 the auxiliary condenser 24 is connected at its inlet end to the compressor discharge 42 with its outlet end connected to a coil tube 44 arranged in the oil sump portion of the compressor 18. The outlet of coil 44 is connected to the main condenser 26 which is in turn series connected through a capillary 46 to the evaporator 13 and thence through a suction line 48 to the inlet of the compressor 18 to complete the refrigerant system. Generally the temperature of the gaseous refrigerant from the compressor discharge entering the auxiliary condenser 24 is in the range of 190°-200° F., however, in extreme ambient conditions the temperature may approach 300° F. This relatively hot temperature due to the heat exchange relationship afforded by the adhesive bond is effective in evaporating the water collected in the pan 32. In operation, as the refrigerant passes through the auxiliary condenser 24 and enters the coil tube 44 in the oil sump of the compressor the temperature of the circulating refrigerent has fallen to approximately 140° F. Since the oil in the operating compressor oil sump is approximately 225° F. the temperature of the relatively cooler coil tube 44 is sufficient to cool the oil and accordingly an oil cooling arrangement is provided. Operation of the system is not affected since refrigerant which may condense in the coil 24 due to the cooling effect will boil and vaporize and accordingly reach the system condenser 26 as a vapor to be condensed. As described the tubing connecting the compressor 18 to be auxiliary condenser 24 is rather rigid and accordingly vibrations generated by the operating compressor are transferred to the auxiliary condenser pan assembly. By the present invention means are provided for supporting the compressor 18 and auxiliary condenser 24 and pan 32 assembly so that they will vibrate in unison. To this end the compressor 18 and auxiliary condenser 24 and pan 32 assembly are resiliently mounted on the base member 19. As best shown in FIG. 4 the base member 19 is lanced in a plurality of spaced locations to provide a plurality of tabs 50. The tabs 50 to be used in mounting the compressor 18 and auxiliary condenser 24 and pan 32 are bent upwardly from the base as shown in FIG. 4 to provide vertically positioned support members. In the present instance as viewed in FIG. 4 one set of four tabs on the left hand side of the base member are provided to support the compressor 18 as will be explained, and another set of two tabs on the right hand side of the base member are provided to support the condenser pan assembly. A resilient elastomer pad or member 52 which is formed to include a central passageway 54 is provided for each of the vertically extending support tabs 50. The resilient pads 52 as shown in FIG. 3 are arranged over the vertical extending support members 50. The vertical dimension of each of the vertical members 50 is greater than that of the pads 52 and accordingly the upper ends extend through the passageways 54. The compressor 18 includes leg portions 56 which correspond in number and location to the one set of support members 50 formed in base member 19. The legs 40 of member 34 align with the other set of support members 50 formed in base 19. With the auxiliary condenser and compressor mounted or positioned as shown in FIGS. 2 and 3 a clip 58 is attached to the upper free end of the vertical support member. The spring clip 58 engages retaining slots 60 formed in the free upper end of the support members 50 so as to trap the resilient pad 52 between the clip 58 and the base member 19. As can be seen by the present support system both the compressor and the support structure for the auxiliary condenser pan assembly are resiliently supported on the base member 19. It should be understood that depending on the compressor employed it may not be necessary to provide oil cooling as described above in which instance the coil portion 44 may be eliminated. In this instance the outlet of the auxiliary condenser 24 would be connected directly to the inlet of the main condenser 26. In another instance, for example in employing rotary compressors, the auxiliary condenser may be employed as a desuper heater coil feeding partially condensed refrigerant to the compressor for cooling purposes. In summary, by the present invention there has been provided a compressor and auxiliary condenser mounting arrangement for evaporating defrost moisture and if desired for cooling the compressor oil including a mounting system which allows the arrangement to vibrate in unison under influence of the operating compressor. It should be apparent to those skilled in the art that the embodiment described heretofore is considered to be the presently preferred form of this invention. In accordance with the Patent Statutes, changes may be made in the disclosed apparatus and the manner in which it is used without actually departing from the true spirit and scope of this invention. What is claimed is: 1. A household refrigerator including a cabinet having a compartment to be refrigerated in the upper portion thereof separated by an insulated partition to include a machinery compartment in the lower portions of and adjacent the rear wall of said cabinet, said compartment extending substantially between the side walls of the cabinet and having an access opening in the rear wall of said cabinet, a unitary refrigerating apparatus adapted to be arranged in said machinery compartment through said access opening, comprising:a base member having a substantially horizontal support wall extending substantially between said side walls; a hermetic compressor mounted on said support wall; a condensate disposing means and oil cooling arrangement including an auxiliary condenser having a first portion located inside said compressor and a second serpentine tube portion disposed outside said hermetic compressor connected to said compressor and a condensate collection container disposed above said serpentine tube portion; means securing said container in heat exchange relation with said serpentine tube portion whereby the high thermal conductivity and condensate evaporation rates are insured; means supporting said condensate disposing means on said support wall including a bracket having leg portions mounted on said support wall and a platform portion spaced from said support wall being dimensioned to receive said container; locking means being dimensioned to engage said container to securely hold said condensate disposing means relative to said platform; an elastomer support means disposed between said compressor and said support wall, and between said leg portions and said support wall for resiliently supporting said compressor and said condensate disposing means relative to said support wall so that said compressor and oil cooling arrangement vibrate in unison. 2. A household refrigerator recited in claim 1 wherein said compressor includes a casing, a sump disposed in the lower portion of said casing for holding cooling medium, said auxiliary condenser further includes a tube portion arranged in said compressor sump in heat exchanging relationship with said cooling medium. 3. The invention recited in claim 1 wherein said base member further includes a plurality of holding tab members formed being dimensioned so as to be bendable selectively to project upwardly from said base member to an operative position;a first set of resilient members including a passageway for receiving a first set of selected upwardly positioned holding tab members with the upper free end of said holding tab members extending above said resilient members; upper body portion on said compressor including openings therein for receiving the upper free end of said holding tab members; holding means secured to said upper free end of said holding tab member for resiliently securing said compressor to said resilient member; a second set of resilient members including a passageway for receiving a second set of selected upwardly positioned holding tab members; holding means secured to said upper free end of said holding tab member for resiliently securing said compressor to said resilient member. 4. A household refrigerator recited in claim 3 wherein said condensate collection container is fabricated of aluminum and said securing means is a hot melt self-curing adhesive.

1984-03-23

en

1985-02-05

US-79269497-A

Plunge milling cutter ABSTRACT A plunge milling cutter is shown which displays an unusually high cutting edge density with positive cutting geometry derived from the configuration of the rake surfaces of its hard metal cutting inserts, notwithstanding their generally parallelepiped form. This is a division, of application Ser. No. 08/335,658, filed Nov. 8. 1994, now U.S. Pat. No. 5,639,189, issued on Jul. 7, 1994. This invention relates to milling tools, and particularly to a high-density face mill for the heavy-duty plunge cutting of metal, and to an indexable cutting insert especially adapted for use in a high-density plunge-milling cutter. The face mill and insert of this invention were developed for the rough machining of the cam lobes of the cam shafts of internal combustion engines. In such service, the cam lobe profile may be milled from a near net-shape forging or casting, or from a cylindrical steel bar, which have been previously turned or milled to provide end and interlobe journals. The lobe locations of the shaft remain as blanks which are then milled into lobe form by plunge feeding the cutter into each lobe blank in turn for the removal of from 20% to 60% of the metal of the blank, depending on the starting stock, in a single revolution of the cam shaft in just over four seconds. The machining operation is illustrated and described in U.S. Pat. Nos. 4,551,048 and 4,624,610. The attainment of metal removal rates of such high magnitude with acceptable tolerances and tool life in the described service was the object of this invention. Tool life, or more precisely, the end of the effective life of the collective edges of a milling cutter, is less a precise condition of the tool than of the monitored power demand and the acceptability of the part or surface produced. In the described application, the characteristics of the cup-shaped milling tool and of the indexable cutting inserts of the invention are such as to provide from 130 to 170 minutes of actual cutting time at surface cutting speeds of approximately 750 feet per minute with a feed rate of 85 inches per minute at maximum depth of cut, which is increased at lesser depths to maintain chip load, i.e., to take maximum advantage of available spindle power, all within a machining cycle of from 4 to 4.5 seconds per lobe. The cutter is plunged into the lobe blank for the initiation of the cut and the cam shaft then rotated to further feed the lobe blank into the rotating cutter while the cutter slide is appropriately advanced into and retracted from the blank under numerical control to define the lobe of the cam. One hundred thirty to one hundred seventy minutes of cutting time equates to a minimum of four hours of shift time of automated, unattended manufacture, given the time required to index the cam shaft from lobe to lobe, and transfer time while the completed workpiece is removed and replaced. Tool-changing time in automated repetitive manufacture in a dedicated set up is typically determined by in-process gauging of the workpiece in the machine to determine when the workpiece no longer meets the tolerance standard established for the piece. The milling tool is then replaced by another and moves to the tool room to have its cutting inserts indexed to present a fresh, unused cutting edge of each insert, or replaced as needed for the same purpose. Satisfactory milling for such a length of time in such strenuous service is made possible in accordance with the invention by the concentration of on-edge cutting inserts in near touching contact in an attitude in which each insert provides over its clearance surface a chip-receiving space for the next insert to enter the cut. The almost shingled relationship of successive inserts without suffering unfavorably negative cutting geometry is made possible by the specially formed rake surfaces of the insert. These allow a substantial heeling (high clearance) of the generally block-shaped inserts of the milling cutter without the excessively negative rake that would otherwise result from the generally rectangular parallelepiped insert configuration, and yet provide eight cutting edges when the major faces are square (four cutting edges when the major faces of the insert are oblong), all of positive rake relative to their adjacent major face, and of near neutral true rake and of positive inclination (effective shear) when mounted in the beveled cutter body. SUMMARY OF THE INVENTION The face milling cutter of the invention has a thick-walled cup-shaped body of high torsional rigidity, which is machined at its open end to provide multiple inclined insert pockets in peripheral saw-toothed array. Each pocket holds a block-shaped, on-edge indexable cutting insert with only slight spacing from its peripherally neighboring inserts, and with its cutting edge disposed at a negative radial rake in a plane normal to the rotational axis and at an outwardly and downwardly sloping bevel angle, so as to sweep a substantially conical path about the tool axis with the apex of that path in front of the cutter. In the described array, the downwardly and rearwardly sloped insert seats provide a space between the workpiece and the clearance face of each insert and the rake face of the following insert into which to receive the chip or chips generated by the cutting edge of the following insert. The rotational axis of the tool intersects the rotational axis of the cam shaft at an angle such that the conical cutting-edge path is essentially parallel to the cam shaft axis in the plane of the two rotational axes. The high density of on-edge cutting inserts of the cutter of the invention (18 to 22 cutting edges on a diameter of 6 inches) is made possible with advantageous cutting geometry by the cutting insert of the invention. It is basically of flat rectangular parallelepiped form in which the narrow faces of the insert provide the rake faces, and the major faces of the insert constitute the flanks or clearance faces. The narrow faces are grooved along and parallel to the major clearance faces to provide a positive sharp cutting edge which is strengthened by imposing on the clearance face, along the cutting edge, a shallow chamfer which serves as the primary clearance land behind the cutting edge. The hook shape of the cutting profile resulting from the adjacent groove in the narrow face, combined with the negative radial rake of the cutting edge, creates effectively positive cutting geometry notwithstanding the otherwise excessively negative heeling disposition of the insert in the cutter body. DESCRIPTION OF THE DRAWINGS The invention is hereafter described in detail in conjunction with the accompanying drawings, in which: FIG. 1 is a plan view of the cutter of the invention; FIG. 2 is an elevational view thereof; and FIG. 3 is a bottom end view of the cutter; FIG. 4 is a plan view of a representative one of the multiplicity of on-edge cutting inserts of the milling cutter of FIG. 1; FIG. 5 is a side elevation of the insert of FIG. 4; FIG. 6 is a fragmentary enlargement of FIG. 5 to provide raked face detail; and FIG. 7 is a fragmentary sectional view taken on the line 7--7 of FIG. 4, with further configurational detail; FIG. 8 is a plan view of the milling cutter from which a number of the inserts have been removed to show the insert seats; FIG. 9 is a fragmentary elevational view of the cutter body affording a further view of the insert seats; and FIG. 10 is a fragmentary sectional elevation of the cutter body taken on the axis of an insert locator pin; FIG. 11 is an oblique elevational view of the cutter in action on a partially milled cam shaft lobe, which is seen in end elevation; FIG. 12 is an oblique elevational view rotated 90° from that of FIG. 11, i.e., transversely of the cam shaft workpiece, and showing in broken lines the outline of the cam lobe in least projection, and in relation to the cutting edges of the cutting tool; FIG. 13 is an oblique view of an alternative form of insert in accordance with the invention, which is rectangular in plan rather than square; FIG. 14 is a plan view of a milling cutter in accordance with the invention adapted for cutting the wider lobe faces of cam shafts for heavy-duty engines; FIG. 15 is a side view thereof; and FIG. 16 is a diagram of the relationship of the apparent rake and shear of a cutter beveled at 15° to the resulting effective rake and shear. DESCRIPTION OF THE PREFERRED EMBODIMENT The plunge-milling cutter of the invention takes the form of an outwardly cylindrical, heavy-walled, cup-shaped body 20 whose rim is milled and ground to provide a multiplicity of contiguous insert pockets 22 about the face of the cutter, each to hold a hard metal cutting insert 24 of particular configuration in a particular attitude so as to present its flank and rake surfaces to the workpiece in a predetermined way. The thick bottom wall 26 of the cup-shaped cutter body is bored and milled to provide a central hole and cross-slot 28 to receive the T-head of the spindle draw bar of a quick-change spindle, or the pilot shaft of a more conventional spindle. The bottom surface is milled to provide a diametrical keyway 30, aligned with the cross-slot 28, to receive the drive keys of the spindle face. Diametrically opposed pins 32 extending upwardly from the bottom wall into the interior space of the cutter body are engaged by the rotation of the T-head of the draw bar as it clamps the cutter body to the spindle face axially and rotationally. Also for use with quick-change spindles, the bottom surface of the cutter body is provided with an integral seating ring 31 whose facing and peripheral surfaces are ground for closely mated fit to the recessed face of such a spindle. The sidewalls 34 of the cutter body narrow in two steps from the heavy bottom wall 26 so that, elementally, the cutter body may be thought of as a base plate surmounted by successively narrower integral rings of which the uppermost carries the cutting inserts 24. In blank form, i.e., before the insert pockets 22 are milled and ground, the upper edge surface 36 of the cutter body is beveled at the cone angle α to which the inserts will be set (FIG. 10), but the beveled surface yields to a generally saw-tooth configuration (FIGS. 8 and 9) as the insert pockets 22 are machined. The insert pockets are best seen in FIGS. 8 to 10 inclusive. Only the upper edge of the rear seating surface 38 of the insert pocket (FIG. 10) remains from the original bevel surface of the tool body after the insert seats are machined. The bottom seating surface 40 of the pocket, which provides the base for the major face of the insert, is a plane surface which is tilted radially outwardly and downwardly at the aforementioned bevel angle α, and tipped rearwardly and downwardly at a heeling angle selected in conjunction with the rake angle of the cutting insert 24 to provide effective cutting geometry, and to allow a space in front of the rake face into which to receive the chip curled from the workpiece by the cutting edge. In the illustrated instance, the bevel angle α is 15°, and is determined by the design of the cam-milling machine, while the heeling angle of the bottom seating surface is 16°. The rear seating surface 38 of the insert pocket is a plane surface perpendicular to the bottom seating surface 40 and angled with respect to a radial plane so as to present the parallel cutting edge of the insert at the desired angle of inclination. To facilitate the simultaneous milling and grinding of both seating surfaces of the insert pocket, a diagonal kerf 42 is cut at their juncture to permit both surfaces to be finished by the pass-through radial feed of a grinding wheel, and to prevent the stress concentration that would otherwise occur if those surfaces were to meet in a sharp corner. As the through-grinding finishing technique is desirable from the standpoint of runout tolerance of the cutting edges, allowing cutting edge runout to be held to 0.0005", a radially inner seating surface, as such, is dispensed with, and the third-axis reference of the insert provided by a separately-installed, upstanding locator pin 44. This is perhaps best seen in FIG. 10, from which it will be apparent that the uppermost ring element of the cutter body 20 is turned to provide an inwardly extending annular ledge 46. Alongside each insert pocket, a hole is drilled and reamed through the ledge, on an axis perpendicular to the plane of the major seating surface 40 of the pocket, to receive the pin 44, a hardened dowel pin, in a drive fit. The undercut of the ledge 46 is preferably a little deeper axially than a half-length of the dowel pin 44, for, in the event of cutter mishap, the hardened dowel pin will shear at the upper surface of the ledge. The undercut permits the clearing of the pin remnant by tapping it on through. The insert 24, shown in detail in FIGS. 4 to 7 inclusive, is a block of hard metal, e.g., sintered tungsten carbide, of generally square parallelepiped configuration. It is located in its pocket by the engagement of three of its mutually perpendicular surfaces with the three locating references of the pocket, namely, the bottom seating surface 40 to engage a major seating surface 48 of the insert, the upstanding rear seating surface 38 of the pocket, to engage that lesser edge surface 50 of the insert which is parallel to the selected cutting edge, and the upstanding locator pin 44 to engage another edge surface 50 of the insert, perpendicular to the selected cutting edge. The insert 24 is firmly held in engagement with all three references by a single countersink-head retainer (not shown) passed through a doubly countersunk through hole 52 centered in the major faces 48 of the insert. The retainer may be a machine screw received in a more or less central tapped hole 54 in the bottom seating surface 40 of the pocket, appropriately oriented according to the "bent-screw" principle of U.S. Pat. No. 3,662,444-Erkfritz to bias the insert 24 against all three locating references, or it may take other specific forms known to the art. In instances where the interlobe clearance of the cam shaft is minimal, it may be necessary to omit the locator pins 44, in which case, the orientation of the force exerted by the retainer is shifted to provide a lateral seating force directed toward the rear locator surface 38 of the insert pocket, rather than diagonally of the insert, as when the pins 44 are used. It may further be noted that the bottom seating surface 40 of each insert pocket 22 is grooved at its forward edge, parallel to the rake face of the insert, to provide additional space for the development of the chip. As earlier said, the general overall configuration of the insert 24 is that of a parallelepiped. In the form illustrated in FIGS. 4 to 12, it is square in plan, its two identical plane, parallel major surfaces 48 serving respectively, and, in turn, as its bottom seating surface and its upper clearance surface, depending upon which of its eight available cutting edges is presented for cutting service. Each of the four lesser edge surfaces 50 of the insert provides two cutting edges 56, one at each juncture with one of the two major faces 48 of the insert. These edges are modified from right-angular intersection by two edge-sharpening grooves 58 of circular cross-section in each edge surface 50 of the insert, parallel to the major surfaces 48 adjacent thereto. Each groove 58 would intersect the extended adjacent major surface 48 of the insert in a cusp which, although advantageously positive, would be too weak to withstand the cutting forces on the insert when heeled at 16°, in the illustrated case. The cutting edge 56 is therefore reinforced by chamfering the edges of the major insert faces, at 9° as illustrated in FIGS. 4 to 7 inclusive, which results in a primary clearance land 60 disposed at a net clearance angle of 7° when the insert is mounted in the cutter body. As the chamfering of the major surface 48 lowers the cutting edge along the cross-section of the groove 58, it intersects the groove in a cusp that may, if desired, be blunted by a touch grind at an angle of from 70° to 90° to the primary clearance land 60, to a width of up to 0.007"(shown in exaggerated scale in FIGS. 6 and 7), to strengthen the edge. The dimensions shown in FIG. 7 are proportionally illustrative of the insert of FIGS. 4 and 5 with overall plan dimensions of 5/8 "square, and may be varied for other sizes. The grooving of the four edge surfaces 50 of the insert to sharpen the cutting edges 56 shifts the cutting edges 56 inwardly of the insert, receding from the initial planes of the edge surfaces 50, which remain as raised central bands which meet at the corners of the insert, where they are relieved by a small chamfer which may be pressed or ground in the insert. Depending upon the degree of blunting, if any, of the cusp at the intersection of the groove 58 with the surface of the primary land 60, a tangent to the groove at its upper edge will preferably make an angle of from 15° to 20° with the adjacent central band of the edge surface 50 of the insert. As the insert when installed in the cutter body is heeled at an angle of 16°, the grooved rake face 58 of the insert at the cutting edge 56 may therefore range from slightly positive to slightly negative true rake but with positive effective shear as presented to the workpiece, i.e., with the rotational axis of the cutter angled away from perpendicular to the axis of the cam shaft by the bevel angle α of the cutter, as in FIG. 11, so that the sweep of the cutting path through the lobe blank 62 is nominally parallel to the cam shaft axis in the common plane of the cutter and cam shaft axes. However, as the rake face 58 is disposed with a positive inclination and near neutral true rake, it enters and moves through the cut diagonally, i.e., in a slashing motion as well as a shearing motion, effectively improving the overall geometry compared to a shearing action alone. This will be evident from FIGS. 11 and 12, which show the cutter axis angularly offset from perpendicularity to the cam shaft axis by the amount necessary to present the beveled cutting path essentially parallel to the cam shaft axis as the cutter is plunged into the workpiece. As shown by the solid partial outline of the cam lobe 62 in FIG. 11, the cutter has entered the lobe quadrant of maximum metal removal with the shortest cutting path. The cam blank is fed into the cutter by clockwise rotation, as seen in FIG. 11, with the cutter in right-hand rotation (viewed from behind the spindle). Inasmuch as the lobe blank is feeding "over the top" into the downward sweep of the cutter, the cut being made is a climb cut, i.e., with the chip thickest at point of entry and thinnest at completion of the cut. As each cutting insert initially contacts the workpiece at maximum depth of cut, its entry into the cut is attended by the shock of collision, requiring that cutter body 20 be rigid and the spindle and workpiece rigidly mounted. The operation is attended with substantial noise, which, however, has been lessened by the cutter of the invention by virtue of the high density of its cutting edges 56, viz., 21 on a diameter of six inches (3.5 per inch) with the result that on the heaviest cut (FIG. 11), there is always one insert in the cut. This greatly reduces the resilient rebound of the workpiece, both torsional and flexural, thus reducing the level of noise in the cutting operation. The economical achievement of high density of cutting edges commensurately with available spindle power in the plunge milling context necessarily involves the engineering resolution of conflicting demands of space and function, which are accomplished with the indexable on-edge cutting insert 24 of the invention. As an essentially square block, the insert provides eight cutting edges at the intersections of its major and lesser surfaces. The maximum number of such inserts which can be accommodated on a given cutter diameter depends upon the width of the chip that must be taken with each cut at the desired cutting geometry. As seen in FIG. 12, where the insert just above center line is entering the cut as the insert on center is leaving, the length of the cutting edge is foreshortened in projection in the cutting direction, which itself changes in the cut. In short, for a given cam face width, the cutting edge must be longer than the cam face width if the cam lobe is to be machined in one plunge-feeding revolution of the lobe blank. The required cutting edge length thus determines the minimum peripheral dimension of a square insert as well, and the maximum number of inserts which can be accommodated at a given cutter diameter. Clearance from the workpiece to receive the curling chip is likewise a major design consideration in the high density milling of steel, and other ductile metals. Basically, the only space available is the triangular space defined by the edge surface of the insert in the cut, the major clearance face of the insert which preceded it in the cut, and the surface of the workpiece (see FIG. 11). This space is created by depressing the trailing edge of the insert to a heeling or clearance angle of 16°, which, in a conventional square block insert, would produce substantially negative cutting geometry. The unacceptably destructive and power-consuming effect of that geometry is overcome by the insert of this invention whose multiply-grooved edge surfaces provide positive cutting geometry within themselves and when drastically heeled, which is then rendered further positive with respect to the workpiece by its rotative positioning with a positive inclination angle for slashing entry into the cut. The achievement of positive inclination angles, also sometimes referred to as "effective shear", in beveled face mills by the use of negative apparent radial rake is itself now an understood phenomenon explained in machining textbooks, for example, Machining Science and Application, Kronenberg, Pergamon Press, 1966, Chapter 5, pp. 85, 86, and earlier, as in U.S. Pat. No. 2,186,417-Charles E. Kraus, 1940, assigned to a company related to the assignee of this invention. The relationship of true rake to apparent radial rake, and of effective shear, or angle of inclination, to apparent shear, or axial rake, is given by the following equations, paraphrasing the foregoing textbook reference: tangent (true rake)= tan (axial rake)×cos (bevel angle)!+ tan (radial rake)×sin (bevel angle)! tangent (effective shear)= tan (axial rake) ×sin (bevel angle)!- tan (radial rake) ×cos (bevel angle)! These mathematical relationships are represented for a bevel angle of 15° by the chart of FIG. 16, the counterparts of which will be found in the aforementioned U.S. Pat. No. 2,186,417 for bevel angles of 30° (FIG. 13) and 45° (FIG. 14). In FIG. 16 hereof, the true rake and effective shear (angle of inclination) are shown for the preferred embodiment of the cutter of the invention with the cutting edges of the inserts blunted to an extent such that the grooved rake surface of the insert has an apparent axial rake (apparent shear) of -1°, and an apparent radial rake of -10°. Projecting those values to the coordinate axes skewed at 15°, and having due regard to the sign of the resulting values, it will be seen that true rake is actually ˜-4°, while the effective shear angle (angle of inclination) is positive at a value in excess of 9°. The favorable resulting geometry and the cutting edge density achievable are believed largely responsible for the relatively quiet operation of the cutter notwithstanding the very high metal removal rates in the described service. While the milling cutter of the invention has been here defined in the conventional terminology of face-mill geometry, it is recognized that the feeding direction of the cutter relative to the work, i.e., the camshaft of the illustrative example, is different from conventional face mill feed. That is, whereas a face mill, whether or not beveled, is fed in a direction perpendicular to the spindle axis, the feeding direction of the illustrated cutter is initially perpendicular to the bevel as the cutter plunges to cutting depth, and then essentially tangential to the bevel as the work piece rotates through its cycle. The invention has been illustrated and described thus far in connection with its preferred form of insert 24, namely the square block form, preferred for the economies to be realized from its eight indexable cutting edges. It will be appreciated, however, from the foregoing discussion of density limitation of square inserts on a given diameter by the required length of cutting edge, that any necessary increase in the length of the cutting edge of the insert for the sake of cam lobe faces of greater width can only be accommodated at the same density by an insert 64 which is oblong rather than square, as shown in FIG. 13, and which therefore can be indexed to only four cutting edges, rather than eight. The same cutting face geometry already described serves the insert 64, and a cutter so equipped, equally well, providing enhanced cutting geometry by the double-grooved configuration of the insert rake face, and the orientation of the insert in the cutter body with a positive inclination angle for slicing entry into the cut. The loss of four cutting edges in the oblong form of insert 64 can have a beneficial trade off, however, in the somewhat greater insert density made possible by the narrower front-to-back dimension of the insert relative to cutting edge width. Practical considerations of chip clearance space and insert strength nevertheless limit the degree to which the insert can be narrowed. An increase in density of 5% (22 inserts versus 21) on a six-inch cutter diameter can be realized as cutting edge length of four-edge indexable inserts according to the invention are extended from 5/8 inch in eight-edge square inserts to 7/8 inch in four-edge oblong. A further adaptation of the milling cutter of the invention is shown in FIGS. 14 and 15. The cutter body 66 is similar to the cutter body 20, previously described, in the sense that it is cup- or bowl-shaped although with heavier sidewalls to accommodate two oblong inserts 64 side-by-side in each pocket, and to handle the heavier cutting loads that result at the same cutting speeds and feeds, such cutters being designed for milling the lobes of the cam shafts of heavy-duty diesel engines. Where two oblong inserts are used side-by-side as illustrated, the inserts of successive pockets are preferably offset from each other radially to avoid leaving a ridge on the workpiece in the event a non-cutting space should occur or develop at the meeting corners of two adjacent cutting edges of the same pocket. The insert of the invention enables the tooling engineer to provide a plunge milling cutter of heretofore unrealized high cutting edge density by utilizing the "on-edge" or tangential form of insert whose preferred simple screw attachment to the insert pocket eliminates the peripheral space requirements of the wedge blocks and screws associated with radially-mounted blade type inserts, while at the same time preserving the strength and torsional rigidity of the cutter body by eliminating the deeply incised pockets required for radially-oriented blade type inserts. The achievement of this high cutting edge density, i.e., with the inserts so close peripherally, demands a high heeling angle to provide chip space for a curling chip of ductile metal, which would normally result in highly negative cutting geometry, absent the rake face geometry of the inserts of this invention. Thus, the geometry of this invention neutralizes the disadvantageously negative cutting geometry that would otherwise accompany density, and results in smoother metal removal without excessive consumption of power. Moreover, the machining operation is accompanied with far less shock and noise than has been associated with the high metal removal rates demanded in this service because of the favorable cutting geometry and because, through most of the cutting cycle, there is always one cutting edge in the cut. The reduction of noise levels has obvious benefits for the attendants, and the reduction of shock can add significantly to the useful life of the milling machine. In the preferred form of insert, namely the insert having square major faces, the cutting advantages specified are achieved with the economy of eight cutting edges on every insert. However, where wider cutting paths are required, as, for example, in milling the cam lobes of a sizeable diesel engine, larger square inserts on the same cutter diameter can only be accommodated at a reduced cutting edge density because of the larger peripheral space occupied by the insert. This, in turn, reduces the metal removal rate, i.e., the production rate. Where favorable cutting edge density cannot be maintained with square inserts, the oblong form comes into its own by providing favorable cutting edge density while, whether mounted singly or doubly as shown, sweeping the wider cutting path. As production rates are thereby increased by reason of both factors, as compared with a square insert of equivalent cutting width, the loss of four cutting edges is balanced or outweighed by higher production rates. As each of these factors is accompanied by its own cost or value, optimal sizes and forms of insert can be determined for any application, other factors being equal. The features of the improved plunge milling cutter and insert of the invention believed patentable are set forth in the following claims. What is claimed is: 1. A high-density plunge milling cutter for milling camshafts, comprising:a thick-walled cup-shaped body attachable to a drive spindle in driving engagement; said cup-shaped body having a rim provided with a multiplicity of inclined seats each having therein a block shaped indexable cutting insert with its active cutting edge disposed to sweep a conical cutting path about an apex in front of the cutter and with said cutting edge disposed forwardly of a parallel radius of the cutter so as to move diagonally in a cut tangent to said conical cutting path; each said insert seat comprising a principal seating surface which is pitched away from said cutting path both in the radially outward direction and in the circumferential direction opposite to the cutting direction, and an edge-seating surface perpendicular to said principal seating surface; said block shaped insert comprising a hard cutting material of generally parallelepiped form having two parallel major plane surfaces serving respectively and interchangeably as a major seating face emplaced upon said principal seating surface and as a clearance face for the insert; said insert also having opposed, plane parallel minor edge surfaces perpendicular to said major surfaces and serving respectively and interchangeably as a cutting face and an edge-seating surface of the insert emplaced against said edge-seating surface of said insert seat; each insert also having therein a hole passing between said major surfaces and countersunk from each and a countersunk-head retainer passed through said hole and into said cutter to secure said insert in engagement with both said seating surfaces of said insert seat; the clearance face of each insert receding from said conical cutting path to the bottom of the cutting face of the succeeding insert to form with said cutting path and said cutting face a triangular chip space for said succeeding insert; said minor edge surfaces of each insert each having therein a pair of grooves each extending the full width of said minor edge surfaces parallel to said major surfaces adjacent thereto with a plane mid-portion of said edge surface between said pair of grooves; said major plane surfaces of each insert having thereon adjacent to each of said minor edge surfaces a narrow land extending the full width of said minor edge surface, each said land making an acute exterior angle with said major plane surface and intersecting the adjacent groove of the adjacent minor edge surface at an acute angle to form therewith straight and parallel cutting edges along at least two opposite sides of each of said major plane surfaces, said disposition of said cutting edge relative to a parallel radius, and the rake of said groove at the cutting edge, resulting in positive effective shear in said cut. 2. The milling cutter of claim 1 wherein a third seating reference is provided for each insert by a pin in said cutter body perpendicular to said principal seating surface adjacent the radially inner edge thereof and projecting to a height above said principal seating surface less than that of the major clearance surface of said insert, said retainer urging said insert into engagement with said pin and said seating surfaces. 3. The cutter of claim 1 wherein the difference between said acute exterior angle and the pitch of said principal seating surface of the insert seat provides a net clearance angle of approximately seven degrees. 4. A high-density plunge milling cutter for milling camshafts, comprising:a thick-walled cup-shaped body attachable to a drive spindle in driving engagement; said cup-shaped body having a rim provided with a multiplicity of inclined insert pockets each comprising a plane seating surface tilted radially outwardly toward the base of said cup-shaped body and tilted toward said base in the peripheral direction opposite to the cutting direction of rotation; an insert abutment surface rising from said seating surface at the edge thereof which is rearward relative to the cutting direction; the edge of said abutment surface remote from said base being adjacent to the forward edge of the seating surface of the succeeding insert pocket; identically shaped on-edge inserts in each of said multiplicity of pockets secured therein by a countersink head retainer passed through a countersunk hole in said insert and into said cutter body so as to clamp the insert against the seating and abutment surfaces of said pocket to assure transmission of the cutting forces from the insert to said tool body at the abutment surface of the pocket; the chip-receiving space associated with each cutting insert being formed essentially by the edge surface of said insert facing in the cutting direction, the clearance surface of the immediately preceding insert, and the surface of the workpiece being cut; and said edge surface facing in the cutting direction having at least a portion providing positive effective shear adjacent to the cutting edge of the insert. 5. The milling cutter of claim 4 wherein said seating and abutment surfaces of each insert pocket are mutually perpendicular and each insert in overall form is essentially a parallelepiped engaged in surface-to-surface contact with the seating and abutment surfaces of one of said pockets. 6. The milling cutter of claim 4 wherein the insert pockets are open in both radial directions to permit through passage of a machining element to machine said seating and abutment surfaces. 7. The milling cutter of claim 6 wherein each insert pocket is flanked on its inner side by an upstanding pin mounted in said cutter body perpendicularly to said seating surface, said pin serving as the radially inward locator for the insert, and said retainer serving to clamp the insert against said seating and abutment surfaces and said pin.

1997-01-29

en

1998-10-13

US-99719492-A

Wheel unit for a baby carriage ABSTRACT A wheel unit for a baby carriage comprises a wheel fixed on a wheel rim, a sleeve member rotatably and releasably disposed in an axial through opening of the wheel rim, and having an axial through bore, and a plurality of hooks and a flange formed on the first and second ends, respectively, of the sleeve member, a pair of pressing plates formed on the flange of the sleeve member, and an axle disposed in the axial through bore of the sleeve member and having an annular groove which is releasably engaged by arcuate-shaped, lower edges of the pressing plates. BACKGROUND OF THE INVENTION A conventional wheel unit used in a conventional baby carriage, as shown in FIGS. 4-6, comprises two wheels 4 and 4' fixed by a shaft support 5 pivotally connected to a support rod 6. The shaft support 5 supports a shaft 7, which passes through the wheel 4' and then through the wheel 4 before being connected to a fixer 72. The fixer 72 has an annular groove 71 which receives a pinch ring 73 for preventing the wheels 4 and 4' from falling off. The wheel unit is covered by a seal cover 74. When the pinch ring 73 is pulled downwardly, it disengages from an annular groove 71, thereby allowing the wheel 4 to be removed from the shaft 7. The conventional wheel unit shown in FIGS. 4-6 has the following disadvantages: 1. The structure of the wheel unit is too complicated. 2. The pinch ring 73 and the shaft 7 are both made of metal, which is susceptible to rust. 3. Wheels 4 and 4' may have different central opening sizes, which increases the manufacturing costs. SUMMARY OF THE INVENTION The present invention has been devised to offer a wheel unit for a baby carriage with the following advantages: 1. A special tool is not needed to take off the wheel unit. 2. An axle and a sleeve member are provided for assembling the wheel unit in a quick and easy manner. 3. The wheel unit of the present invention has fewer components than the prior art wheel units, thereby reducing the costs of packaging and transportation of the wheel unit of the present invention. 4. The shaft and shaft tube are made of a strong, anti-friction plastic, thereby preventing rusting of these components. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood with reference to the accompanying Drawings, wherein: FIG. 1 is an exploded perspective view of a wheel unit for a baby carriage of the present invention; FIG. 2 is a side cross-sectional view of the wheel unit for a baby carriage of the present invention; FIG. 3 is a side cross-sectional view of the wheel unit for the baby carriage of the present invention, showing the disassemblage of the same; FIG. 4 is a perspective view of a conventional baby carriage; FIG. 5 is a cross-sectional view of a conventional wheel unit of a conventional baby carriage with FIG. 4; and, FIG. 6 is a cross-sectional view of related components for disassembling the conventional wheel unit of the conventional baby carriage. DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIGS. 1-3, the wheel unit of the present invention comprises a wheel rim 11, a wheel 1, a sleeve member 2, and an axle 3. The wheel rim 11 is provided with an axial through opening 111 having an outer side surface and an inner side surface. The wheel 1 is disposed on the wheel rim 11. The sleeve member 2 comprises axial through bore 222, first and second open ends, a plurality of hooks 221 disposed around the first end of the tubular portion 22, and a flange 224 formed on the second end of the tubular portion 22. Each hook 221 has a sloped surface 223. A pair of pressing plates 21 extend laterally from the flange 224 in opposing directions. The pressing plates 21 have arcuate-shaped, lower edges 211 which define a substantially circular-shaped opening 212 therebetween. The axle 3 comprises an elongated cylindrical member having first and second ends, and an annular groove 32 formed in the axle 3 adjacent the first end 31. When assembling, the first end of the tubular sleeve member 2 is inserted into and through the axial through opening 111 of the wheel rim 11 until the hooks 221 engage the inner side surface of the axial through opening 111 and the flange 224 abuts the outer side surface of the axial through opening 111, thereby rotatably securing the sleeve member 2 within the axial through opening 111. Next, the first end 31 of the axle 3 is inserted into the second open end of the tubular portion 22 until the first end 31 of the axle 3 extends through the first open end of the tubular portion 22 and the arcuate-shaped, lower surfaces 211 of the pressing plates 21 engage the annular groove 32 of the axle 3, thereby securing the axle 3 in the axial through bore 222 of tubular portion 22. When disassembling, as shown in FIG. 3, the pressing plates 21 are pressed inwardly until the arcuate-shaped, lower edges 211 of the pressing plates 21 are disengaged from the annular groove 32 of the axle 3, thereby allowing the axle 3 to be pulled from the axial through bore 222 of the tubular portion 22. Next, the hooks 221 of the tubular portion 22 are pressed inwardly until they can be passed through the axial through opening 111 of the wheel rim 11, thereby allowing the sleeve member 2 to be pulled from the axial through opening 111. While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claim is intended to cover all such modifications which may fall within the spirit and scope of the invention. What is claimed is: 1. A wheel unit for a baby carriage comprising:a wheel rim having an axial through opening, said axial through opening having inner and outer side surfaces; a wheel disposed on said wheel rim; a tubular sleeve member adapted to be releasably and rotatably received within said axial through opening of said wheel rim, said sleeve member having a tubular portion with an axial through bore, first and second open ends, a plurality of hooks and a flange formed on said first and second ends, respectively, of said tubular portion for releasably and rotatably securing said sleeve member in said axial through opening of said wheel rim, and a pair of pressing plates extending laterally from said flange in opposing directions, said pressing plates further including arcuate-shaped, lower edges; and, a cylindrical axle adapted to be releasably received in said axial through bore of said sleeve member, said axle having first and second ends, and an annular groove formed adjacent said first end of said axle, wherein said arcuate-shaped lower surfaces of said pressing plates are adapted to be received in said annular groove of said axle, and said pressing plates may be pushed inwardly for releasing said arcuate-shaped, lower edges of said pressing plates from said annular groove of said axle.

1992-12-28

en

1994-01-11

US-62550396-A

Method of making a protective coating material ABSTRACT A protective, impact resistant material and method which includes a fabric of thermoplastic polymeric fibers having a strength of at least 0.5 GPa and an elastic modulus of at least 25 GPa and a matrix of polymeric material disposed in the interstices between the fibers having an elastic modulus of 0.2 to 3×10 6 psi. The polymeric fibers can be gel spun, polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. In a second embodiment, the matrix is derived from the fabric. The method includes the steps of providing a matrix of melted polymeric material transparent to energy of a predetermined type and having a predetermined melting temperature, placing a fabric of polymeric fibers having a melting temperature higher than that of the matrix in the matrix, applying a pressure of 1000 to 2000 psi to the fabric in the matrix, then raising the temperature to the melting temperature of the fabric for the time required to cause consolidation of the fabric and the matrix and rapidly cooling the consolidated fabric and matrix to a temperature below the melting temperature of the fabric. In accordance with the second embodiment there is provided a fabric of polymeric fibers as in the first embodiment which is operated upon as in the first embodiment to cause melting of a sufficient portion of the fabric to fill the interstices between the fibers of the fabric. The fabric is then rapidly cooled to a temperature below the melting temperature of the fabric. CROSS REFERENCE TO RELATED APPLICATIONS This application is a Division of application Ser. No. 08/487,818, filed Jun. 7, 1995, now pending, which is a division of Ser. No. 08/241,218, filed May 11, 1994, now U.S. Pat. No. 5,573,824. This application is related to Ser. No. 07/939,256, now U.S. Pat. No. 5,824,586 filed Sep. 2, 1992, of Paul Klocek et al., the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention This invention relates generally to a tough, durable and impact resistant continuous polymer. The polymer in accordance with this invention has very high strength and stiffness in a direction parallel thereto while being compliant in a direction normal thereto. This permits the polymer to be very impact resistant and relates it to applications where high strength and/or impact resistance is desired in a moldable material. Since the polymer in accorance with the invention is continuous, it also relates to applications requiring high strength and/or impact resistance while being impermeable or transparent. More specifically, this invention relates to, but is not limited to, optical coatings for windows and domes (a window being defined herein as something between a system and the environment to protect the system from the environment) and particularly, but not limited to, coatings for infrared windows and domes, primarily, but not limited to, use on aircraft, and, more specifically to a polymer or plastic optical coating to protect infrared optics, particularly infrared windows and domes. Brief Description of the Prior Art To increase the survivability and operational capability of infrared windows and domes, particularly as used during flight and particularly for the 8 to 12 micrometer wavelength (infrared) region, protective coatings are required for rain, dust, sand and hail impact. The impact of these particles during flight (aircraft, missile, helicopters etc-) on the window or dome erodes the window or dome, thereby reducing its strength and ability to transmit infrared or other energy radiations therethrough. This degradation can render the electro-optical sensor behind the dome or window inoperable or even damaged should the window or dome catastrophically fail. Presently used prior art infrared windows and domes degrade in performance due to loss of transmission and strength due to environmental degradation, particularly due to erosion by rain, dust and sand particles at aerodynamic speeds Prior art solutions to this problem have involved the use of a protective coating on the infrared domes and windows. Due to the requirement that the protective coating be transparent in the wavelength region in which the window or dome operates (i.e., 8 to 12 micrometers, 3 to 12 micrometer, 3 to 5 micrometers, 1 to 12 micrometer, etc.), past and current efforts on protective coatings have concentrated on traditional inorganic materials, such as silicon, gallium phosphide, boron phosphide, diamond, germanium carbide, silicon nitride, silicon carbide, oxides, etc. to obtain. the desired transparency These coating have displayed high strength, high fracture toughness, high hardness and moderate to high elastic (Young's) modulus. The general mechanical requirements of coatings for soft (rain) and hard (sand, hail, dust, etc.) particle impact protection of substrates are low hardness and high fracture toughness or strength with a high elastic modulus to reduce the strain induced in the substrate or a low elastic modulus to absorb the impact stress. Accordingly, the above-mentioned materials have shown only limited effectiveness in solving the problem of erosion due to particle impact and have been difficult to scale up in size. It is therefore apparent that other solutions to the problem were required which overcome or minimize those problems. The above described problems were reduced by providing polymeric coatings for infrared windows and domes which were infrared transparent polymers with low hardness and high strength as set forth in the above-mentioned application. These polymers absorb and distribute the stresses of the impacting particles, thereby protecting the underlying infrared optics, primarily infrared windows and domes and primarily, but not limited to, the 8 to 12 micrometer wavelength range. The polymeric infrared transmitting coating described in the above mentioned application has been found to be very effective in providing the required protection for infrared windows and domes against particles which do not set up stress waves in the plane of the window or dome surface. Such materials are inexpensive and readily available in films which can be placed on the exterior surface of an infrared window or dome Polymers had been overlooked prior to the above noted application for use as infrared optical protective coatings, apparently due to their well-known absorption bands throughout the infrared range. These bands are the intrinsic molecular vibrational absorption due to the constituents of the polymer (i e., C-H stretching, bending modes). However, on detailed analysis of the infrared spectra of various polymers, some are highly transparent in, for example, the 8 to 12 micrometer regions where considerable interest and applications exist for electro-optical systems. These same 8 to 12 micron transparent polymers and copolymers, such as, for example, and not limited to, polyethylene, ethylene-octene copolymer, polyvinylpyrrolidene, poly(acenaphthylene), styrene/ethylene-butylene copolymer, poly(1-butene), poly(acrylic acid, ammonium salt), polyamide resin, ethylene/propylene copolymer and ethylene/propylene/diene terpolymer, possess low hardness, high strength and low elastic (Young's) modulus, making them candidates as particle impact and erosion resistant coatings for infrared windows and domes. The polymers of choice in the above noted applications are those that provide infrared transmissivity in the desired wavelength range, such as, for example, 8 to 12 micrometers, low hardness less than about 50 kg/mm2, high strength in the range of 10,000 to 100,000 psi with a preferred value of greater than 20,000 psi and low elastic (Young's) modulus in the range of 0,2 to 3×106 psi and preferably less than 0.5×106 psi. Most polymers do not display transmissivity in the infrared range and it has been generally believed that polymers in general do not display such transmissivity and are absorbent to infrared energy. In those cases where the polymers provide the desired optical properties but fail to provide the desired mechanical properties, copolymers of the optically desirable polymers and other polymers which provide the desired mechanical properties can be formulated to provide a compromise which still presents the critical properties in the desired ranges. The ethylene-octene copolymer is an example of such copolymer. Additional copolymers or terpolymers are desirable to optimize the optical transparency and the mechanical and thermal properties, particularly strength and thermal stability. Candidates include polyethylene, ethylene-octene copolymer, polyvinylpyrrolidene, poly(acenaphthylene), styrene/ethylene-butylene copolymer, poly(1-butene), poly(acrylic acid, ammonium salt), polyamide resin, ethylene/propylene copolymer and ethylene/propylene/diene terpolymer, which are infrared (8 to 12 micrometers) transparent and neoprene, polyurethane, fluorelastomer, polycarbonate, polyether sulfone, polyether etherketone and polyacrylate which are very rain erosion resistant. Also, the copolymers can be tailored to provide vibrational modes of the atoms therein at frequencies outside of the optical frequency range of interest to possibly provide the desired transmissivity in the frequency range of interest. The sheet of polymeric material is placed on the optical window or dome in any of many well known ways, such as, for example, by static or chemical bond with or without an intermediate "glue" layer, as required, spinning on, spraying on or cast on and allowed to set. A problem with the above described polymeric sheet material is that it is compliant in both the plane normal thereto as well as in the plane thereof. Accordingly, though hard particles, such as sand, cause stress waves to propagate essentially only along the line of impact of the window therewith, which is normal to the plane of the polymeric material, rain additionally causes stress waves to propagate along the surface of the window in a direction essentially along the plane of the window and the polymeric covering thereon. These stress waves in the plane of the polymeric material cause a polymer coating of the type discussed with reference to the above noted copending application to move along the path of the stress waves or in the plane of the polymeric coating. Since the window or dome to which the coating is attached does not undergo such movement, there is a tendency for the polymer coating to separate or delaminate from the dome or window and eventually tear and thereafter possibly further be removed from the window. This causes a loss of the window or dome protection previously obtained from the coating. SUMMARY OF THE INVENTION In accordance with the present invention, the above described problem of the prior art is minimized. This is accomplished by providing a high strength (from about 10,000 to about 100,00 psi and preferably greater than 20,000 psi), high elastic modulus (from about 50 to about 200 GPa and preferably about 100 GPa), solid and continuous polymeric material in the form of a fabric of overlapping and underlapping sinusoidal woven fibers designed or derived from high molecular weight polymer and consolidated to maintain the crystalline weave with a high degree of controlled orientation The polymeric fibers are preferably, but not limited to, polyethylene which is woven and consolidated whereby the orientation and weave is retained in the crystallites and/or molecules. This is preferably accomplished by use of just the woven fiber but can also involve disposing the woven polymeric fabric in a matrix, the matrix being preferably of a polymeric material suitable for use as required in the above noted copending application. The woven fiber or the woven fiber and matrix are consolidated in some manner, such as by hot pressing, calendaring, tentering, etc The woven fiber fabric is heated under a pressure of about 1000 psi or more and preferably from about 1000 to about 2000 psi to a temperature at or slightly above its melting point for the minimum period of time required to cause consolidation of the woven fibers and/or the woven fibers and matrix, this taking generally less than about 60 minutes. The consolidated fibers and matrix are then cooled rapidly, generally in 5 minutes or less, to below 100° C. The rapid cooling is to maintain the orientation of the long molecule chains (high molecular weight) intact to the greatest extent possible concomitant with the fiber and/or fiber/matrix consolidation. The result is a coating which is strong in the plane of the coating, yet compliant and elastically deformable in a direction normal to that plane so that the coating is able to absorb and store any impact stress thereto Any polymeric material with high (about 0.5 GPa or 70,000 psi strength and high (-25 GPa or greater or 3.6×106 psi or greater) elastic modulus which is a thermoplastic that can be processed as required above can be used. Examples of materials which can be so used are, but are not limited to, gel spun high molecular weight polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. A polyethylene fabric composed of "Spectra" fibers, sold commercially by Clark-Schuabel Co. and having a molecular weight of approximately 1,000,000 has been found to be extremely suitable for use in accordance with the present invention. Suitable polymers are generally linear polymer chains and generally have molecular weights on the order of about one million or more. The woven fabric need not be transparent in the range of interest though the matrix, if used, must be transparent in that range. When the fabric is not transparent in the range of interest, the fibers thereof must be sufficiently spaced apart to permit an adequate amount of the radiation of interest to pass between the fibers and the matrix, if any, disposed between the fibers. In a further embodiment of the inventions the matrix can be omitted and the polymeric fiber fabric itself can be heated under pressure and temperature conditions the same as above described for use in conjunction with the fabric and matrix to flatten the fabric and cause the material forming the fibers to flow into the interstices between the fibers. This results in a continuous sheet of the fibrous material with the interstices filled with the same material as the fibers since the interstices are now filled with polymeric material which has flowed from the fibers. In practice, the above described fibrous material is secured over a window or radome in place of the prior art coatings in well known manner to provide protection. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of a fabric disposed in a matrix in accordance with the present invention; FIG. 2 is a cross section taken along the line 2--2 of FIG. 1; and FIG. 3 is a cross section taken along the line 3--3 of FIG. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS. 1 to 3, there is shown a first embodiment of a coating material in accordance with the present invention. In accordance with this embodiment, there is provided a fabric 1 of very high molecular weight polyethylene fibers having a molecular weight of approximately 1,000,000, the particular fabric used being composed of "Spectra" fibers, sold commercially by Clark-Schuabel Co. The fabric 1 is composed of a plurality of sinusoidally shaped fibers in two groups 3 and 5, each of the groups disposed orthogonally to the other with the fibers of each group overlapping and underlapping the fibers of the other group as shown in FIGS. 2 and 3. The fabric 1 may or may not be placed between two sheets of a matrix 7 of a polymer having a melting temperature lower than that of the fabric. The fabric fiber can also be drawn with a matrix polymer coating or cladding thereon or the fabric can be immersed or sprayed with a liquid polymer (i.e. melted, dissolved, etc.) If a matrix is used, the infrared transmitting polymers mentioned above, i.e., polyethylene, etc. are preferred. The fabric or the fabric with the matrix are placed under pressure of 1500 psi in, for example, a hot press with a hydraulic ram and the temperature is raised to between 140° C. and 190° C., this temperature being at or slightly above the melting temperature of the fabric which, in this case, is 140° C., for 60 minutes or less to permit the fibers to melt sufficiently to permit the fabric or the fabric and matrix to consolidate without material breakup of the long molecular chains comprising the fabric fibers. The consolidated polymer is then rapidly cooled to less than 100° C. in 5 minutes or less. The final material can now be used to coat optical devices in standard manner or as an impact resistant coating for other non-optical applications or as a free-standing polymer for structural, optical or other applications. In accordance with a second embodiment of the invention, the fabric 1 of FIG. 1 is used without the matrix. The fabric 1 is heated to a temperature between 140° C. and 150° C. under the same pressure conditions as in the first embodiment for about 60 minutes or less until the fibers have melted and flowed sufficiently so that the fiber material also fills the interstices between the fibers and forms a continuous material. The continuous material is then rapidly cooled as above to provide the final material required for coating an optical device. Though the invention has been described with respect to specific preferred embodiments thereof, many variations and modifications will immediately become apparent to those skilled in the art. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications. We claim: 1. A method of making a protective coating material, comprising the steps of:(a) providing a fabric of polymeric fibers having a predetermined melting temperature, said fabric having interstices between said fibers defined by said fibers; (b) applying a pressure of from about 1000 to about 2000 psi to said fabric; (c) concurrently with said applying a pressure of from about 1000 to about 2000 psi to said fabric, raising the temperature of said fabric to about and at least the melting temperature of said fabric for the time required to cause melting of a sufficient portion of said fabric to fill said interstices between said fibers of said fabric; and (d) then rapidly cooling said fabric to a temperature below the melting temperature of said fabric to maintain the long molecule chains (high molecular weight) intact to the greatest extent possible concomitant with the fiber and/or fiber/matrix consolidation. 2. The method of claim 1 wherein said fabric is composed of a first group of spaced apart fibers extending in a first direction and sinusoidally shaped and a second group of spaced apart fibers extending in a direction essentially normal to said first direction and sinusoidally shaped, said fibers of said second group alternately overlying and underlying fibers of said first group. 3. The method of claim 2 wherein said polymeric fibers are taken from the group consisting of gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. 4. The method of claim 1 wherein said polymeric fibers are taken from the group consisting of gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. 5. The method of claim 1 wherein said fibers are thermoplastic and have a strength of at least 0.5 GPa (70,000 psi) and an elastic (Young's) modulus of at least 25 GPa (3.6×106 psi) and said matrix has an elastic modulus in the range from about 0.2 to about 3×106 psi. 6. The method of claim 5 wherein said fabric is composed of a first group of spaced apart fibers extending in a first direction and sinusoidally shaped and a second group of spaced apart fibers extending in a direction essentially normal to said first direction and sinusoidally shaped, said fibers of said second group alternately overlying and underlying fibers of said first group. 7. The method of claim 6 wherein said polymeric fibers are taken from the group consisting of gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. 8. The method of claim 5 wherein said polymeric fibers are taken from the group consisting of gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate.

1996-03-29

en

1999-03-09

US-51767565-A

Gas scrubber y 1967 w. J. ARMIGER, JR GAS SCRUBBER 5 Sheets-Sheet 1 Filed Dec. 30, 1965 INVENTOR WILLIAM J. ARMIGER JR ATTORNEYS May 2, 1967 W. J. ARMIGER, JR 3,317,200 GAS SCRUBBER Filed Dec. 150, 1965 3 Sheets-Sheetv 2 :3 i 1'?) 0 j 2 1 o N it Q l l 1;. INVENTOR WILLIAM J. Q] g AIiQDMIGER JR. q H I w a 4 L; N ATTORNEY? May 2, 1967 w-. J. ARMIGER, JR GAS SCRUBBER 3 Sheets-Sheet 3 Filed Dec. 30, 1965 I so INVENTOR ARMIGER JR. WILLIAM J. ATTORNEYS United States Patent 3,317,200 GAS SCRUBBER William J. Armiger, Jr., Princeton, N.J., assignor to Research-Coftrell, Inc., Bridgewater Township, N.J., a corporation of New Jersey Filed Dec. 30, 1965, Ser. No. 517,675 5 Claims. (Cl. 26164) This invention relates to the scrubbing of particulate laden gases and more particularly to a device which performs the simultaneous functions of effecting a pressure drop across an orifice in a gas flow stream and of wetting the particulates by virtue of turbulence created by the gas flow through the orifice. In many industrial processes, the wetting of the particles in a particle laden gas stream facilitates their subsequent removal from the gas stream thus both cleaning the gas and also assisting, in certain instances, in the recovery of the particles themselves. By placing an orifice in a duct wherein the orifice has a lesser aperture than the duct aperture which carries particle laden gases, a pressure change across the orifice is effected and it is in the area of this pressure drop that washing liquid, as for example, water, is introduced into the particle laden gas stream for intimate mixing of the gas with the liquid. In many instances, depending upon the particular nature of the gas and particles carried thereby and depending upon total system gas pressure requirements there is an optimum pressure loss across the orifice which should be maintained. This optimum pressure loss often varies continually. By the use of a variable aperture orifice, the pressure drop across the orifice may be varied so as to maintain the optimum condition. The effective aperture of such a variable aperture may be regulated by pressure sensing means in combination with automatic means to vary the effective aperture. One example of a variable aperture orifice, although not necessarily for the intended particle laden gases, is given by US. Patent 2,801,647 to Dorrel et al. and may be described as a louver type wherein rotating vanes or louvers are placed in parallel and rotated in opposite directions to thereby vary the effective aperture of a fixed aperture Such an arrangement, while apparently satisfactory for the intended purpose, it is not suited for all types of gas purpose of scrubbing or opening in a duct. ' placeable. used in conjunction with the rotating louvers illustrated at FIGURES 1-3 inclusive. Referring now to FIGURES 1 and 2 of the drawings, the numeral 10 denotes generally the variable orifice scrubber assembly according to this invention and comprises a cylindrical duct section having walls 12 and upper and lower flanges 14 and 16 adapted for coupling to complementary flanges on duct portions which the duct section 12 is adapted to join. The numeral 18 denotes a plate having a square central aperture therein with the plate being secured transversely across the longitudinal axis of the duct section. The numeral 20 denotes a centrally located aperture within plate 18 along whose four edges are secured longitudinal inserts 22 to which are attached at their upper portions clip elements 24 which cooperate with bracket elements 26 placed on the lower portion of elements 22 to hold the latter in position. Preferably, the elements 22 are formed of a refractory material or metal casings having a high resistance to the action of heat and abrasion and by virtue of the clips 24 and 26 attached thereto are easily refittings coupled to tubular elements 30 positioned in and supported 'by the cylindrical wall of duct section 12. A tubular nozzle 32 is coupled to one end of each elbow 28 and projects into the area of the duct section. As shown in FIGURE 1 of the drawings, there are preferably a plurality of such elbows 28 for injecting liquid into the gas stream which flows through duct segment. A cylindrical aperture 34 may be provided at one portion 1 of the wall of the duct section for receiving a short bearings 44. A bracket 46 scrubbing installations wherein the variable orifice de- 1 vice is subject to the deleterious action of extremely high temperature particle laden gasesor touany situation where the action of the gases on the louver type vanes would be such as to cause or to necessitate frequent replacement thereof. According to the practice of the present invention, a variable orifice scrubber assembly for a gas scrubbing device is provided with adjustable louver type vanes for effecting a variable orifice wherein the vanes are susceptible of easy replacement of the parts thereof exposed to the often deleterious effects of the particle laden gases which they are designed to control. In the drawings: FIGURE 1 is a plan view of a duct section provided with a variable aperture orifice and means for introducing liquid into the duct section. FIGURE 2 is a cross-section taken along line 22 of FIGURE 1. FIGURE 3 is a view taken along line 3-3 of FIGURE 2. FIGURE 4 is a view taken along line 44 of FIGURE 3. FIGURES 5 and 6 are perspective views of certain elements defining the louver type vanes illustrated in the preceding figures. FIGURE 7 is a plan view of another type of element rotating element 50. The numeral 68 denotes a power placement purposes. flanged pipe section 36 adapted to receive a manhole cover 38. The aperture 34 may be termed an access aperture since the removal of the manhole cover 38 will permit access to the upper portion of plate 18 and also facilitates inspection of the below described louver elements. The numeral 40 denotes either of a pair of shafts or rectangular cross section, one end of which is mounted in bearings 42 and the other ends of which pass through is suitably secured to the duct section and supports bearings '42. Similarly, bracket 48 is also secured to the duct section and supports bearings 44 and also an automatic turning control element 50, the functionv of which will later be described. Bushing members 52 and 56 support shafts 40 at each place where they pass through the duct sections. Bushing 52 is supported by demountable plate 51 whose removal, together with hearing 42, permits the vane elements 70 and (to later be described) to be slid off shafts 40 for re- Pressure sensing elements 60 and 62 are positioned above and below, respectively, orifice plate 18 and the numerals 64 and 66 denote, respectively, lines preferably electrical, which feed signals corresponding to the pressure sensed by elements 60 and 62 to louver input to element 50. Referring now to FIGURES 3 through 7 of the drawings, the numeral 70 denotes any one of a plurality of generally elongated refractory elements having curved, generally semi-cylindrical portions 72 at the top of the bottom. Elements 70 are positioned immediately adjacent aperture 20 of plate 18 and generally medially of each of the shafts 40 which extend across duct section 10. As will be seen more particularly from an inspection of FIGURES 4, 5 and 6, each element 70 is provided at one face with an integral extending lip 74 extending around a square aperture 76 adapted to receive the shaft 40. The elements 70 are assembled as illustrated at FIG- URE 4 of the drawings. As shown at FIGURE 7 of the drawings, the numeral The numerals 28 denote flange type elbow 80 denotes any one of a plurality of refractory elements each of which is provided at one face with an extending lip 82 preferably integral therewith. Further reference to FIGURE 4 discloses how elements 80 are assembled, each of their central apertures 84 being square in cross section to receive shaft 40. The refractory elements 70 and 80 are placed over shaft 40, much as in the manner of beads strung on a piece of String or wire. The endmost elements 80 abut column portions 53 and 57 of bushings 52 and 56 respectively. The mode of operation of the above described variable orifice scrubber assembly is as follows. Particle laden gases pass upwardly through the duct section 12, i.e., from the direction below the shaft 40 towards the nozzles 32, with reference to FIGURE 2, and cleaning liquid, such as water, is injected through nozzle 32 into the gas flow stream. The velocity of cleaning liquid ejection for various applications will vary and in certain applications this velocity is low. Pressure sensing elements 60 and 62 sense the downstream and upstream pressures, respectively, within the duct section 12 and signals corresponding to these pressures are fed into louver rotating element 50 through lines 64 and 66. By means of suitable gearing within element 50, the louver vanes 70 and shaft 40 are rotated to assume that specific angular relationship which will yield the optimum pressure drop at the gasliquid mixture zone which effects the maximum wetting of the particles within the gas. Reference to FIGURE 3 of the drawings shows that the angular position of louver element 70 may be varied from the solid position shown, which will yield a maximum effective aperture area, to the dotted position, which Will yield a minimum effective aperture area. Thus the maximum angular displacement of each of the shafts 40 need only be 90. The particulate laden gases striking the cast louver elements 70 and 80 create a turbulent volume which extends from the louver elements to the other side of aperture 20. The edges of elongated refractory elements 22 which are in the gas path also effect some turbulence and this further enhances the wetting of the particles in the gas from the liquid stream coming into the duct section through nozzles 32. While the louver rotating element in FIGURES 1 and 2 has been illustrated and described as automatic, as by a suitable servo mechanism as element 50', particularly in conjunction with pressure sensing elements 60 and 62, it will be understood that the shafts 40 may be manually rotated. The worker in this art will recognize that the refractory elements 22, 70 and 80 are under the deleterious action of both heat, in the case of hot gases, and of the particles themselves carried thereby whether the gases be at extremely high or elevated temperatures or not. Continued operation of any variable orifice scrubber assembly, such as the assembly of this invention, will often result in an eventual requirement for a replacement of those parts or those elements in the gas stream which are subjected to the greatest wear. By virtue of the simplicity of construction of elements 22, 70 and 80, any material which is particularly suited to withstand the above enumerated deleterious actions of the particle laden gas stream which is to be wetted may be used. Thus, any type of refractory substance may be easily cast and employed as elements 22, and 80. Similarly, the advent of an ever more numerous selection of materials, with the continued advancement of technology, any type of material may be employed for these elements, not necessarily one known as a refractory material. The requirement for sometimes frequent replacement of such elements as these demands a construction which will admit not only of easy replacement but of a simple shape or configuration of those elements which must be replaced. Here, the worker in this art will readily appreciate that elements 22, 70 and are of simple shapes or configurations and thus admirably answer the above noted requirements. What is claimed is: 1. A variable orifice gas scrubber assembly including: a housing having two open ends; a plate in said housing positioned generally transversely to the longitudinal axis thereof, said plate having an aperture therein, means in said housing positioned axially of said plate for injecting a liquid into the interior of said housing, a rotating louver element positioned within said housing and contiguous to said opening and extending generally transversely of said housing, said louver having a generally elliptical cross-section over at least a portion of its length, said louver comprising a plurality of stacked elements traversed by a shaft passing therethrough, said louver being slidable off its supporting shaft and adapted to be withdrawn therefrom and from the interior of said housing. 2. The variable orifice scrubber assembly of claim 1 wherein said louver comprises a first plurality of stacked elements each of which is generally elliptical in crosssection and a second plurality of stacked elements each of which is generally circular in cross section. 3. The variable orifice scrubber assembly of claim 2 wherein said stacked elements each comprise an element having an aperture therethrough and an integral lip on one side of said aperture mating with a complementary recess of an adjacent element. 4. The variable orifice scrubber assembly of claim 1 wherein the periphery of said aperture in said plate is lined with a heat and abrasion resistant element demountable therefrom, with a portion of said resistant element extending radially inwardly of the said periphery. 5. The variable orifice scrubber assembly of claim 1 including means to sense gas pressure in said housing on opposite sides of said aperture plate, and means for rotating said louver in response to a sensed difference in gas pressure across said aperture. References Cited by the Examiner UNITED STATES PATENTS 6/1965 Rehmus 261-188 X HARRY B. THORNTON, Primary Examiner. T. MILES, Assistant Examiner. 1. A VARIABLE ORIFICE GAS SCRUBBER ASSEMBLY INCLUDING: A HOUSING HAVING TWO OPEN ENDS; A PLATE IN SAID HOUSING POSITIONED GENERALLY TRANSVERSELY TO THE LONGITUDINAL AXIS THEREOF, SAID PLATE HAVING AN APERTURE THEREIN, MEANS IN SAID HOUSING POSITIONED AXIALLY OF SAID PLATE FOR INJECTING A LIQUID INTO THE INTERIOR OF SAID HOUSING, A ROTATING LOUVER ELEMENT POSITIONED WITHIN SAID HOUSING AND CONTIGUOUS TO SAID OPENING AND EXTENDING GENERALLY TRANSVERSELY OF SAID HOUSING, SAID LOUVER HAVING A GENERALLY ELLIPTICAL CROSS-SECTION OVER AT LEAST A PORTION OF ITS LENGTH, SAID LOUVER COMPRISING A PLURALITY OF STACKED ELEMENTS TRAVERSED BY A SHAFT PASSING THERETHROUGH, SAID LOUVER BEING SLIDABLE OFF ITS SUPPORTING SHAFT AND ADAPTED TO BE WITHDRAWN THEREFROM AND FROM THE INTERIOR OF SAID HOUSING.

1965-12-30

en

1967-05-02

US-20592062-A

Telephone switching network Jan. 25, 1966 T. N. LowRY TELEPHONE SWITCHING NETWORK 8 Sheets-Sheet 2 Filed June 28, 1962 STAGE L/ NE TERM/NALS Jan. 25, 1966 T. N. LowRY TELEPHONE SWITCHING NETWORK 8 Sheets-Sheet 3 Filed June 28, 1962 STAGE 4 STAGE 3 Jan. 25, 1966 T. N. LowRY 3,231,579 TELEPHONE SWITCHING NETWORK Filed June 28, 1962 8 Sheets-Sheet 4 SELECT 2 T. N. LOWRY TELEPHONE SWITCHING NETWORK Jan. 25, 1966 Filed June 28, 1962 m. GP* Jan. 25, 1966 T. N. LowRY TELEPHONE SWITCHING NETWORK 8 Sheets-Sheet 6 Filed June 28, 1962 mmm. Nk /QQ S \VI|.U l `m$u mh ES n I` .2 fg MRL rob T||| n II @Q fm2 NS. WIL RS fo@ l 4| faQ fm2 .l/.NI RQ r QQ mv f /Qm klom Bowl XS( mm mm mm mm mm Q wk MS NIR Imi l l. l I. Jan. 25, 1966 T. N. LowRY 3,231,579 TELEPHONE SWITCHING NETWORK Filed June 28, 196? 8 Sheets-Sheet 7 Jan. 25, 1966 T. N. LOWRY TELEPHONE SWITCHING NETWORK 8 Sheets-Sheet 8 Filed June 28, 1962 United States Patent O 3,231,679 TELEPHONE SWITCHING NETWORK Terrell N. Lowry, New York, NSY., assignor to Bell Telephone Laboratories, Incorporated, New York, NY., a corporation of New York Filed June 28, 1962, Ser. No. 205,920 41 Claims. (Cl. 179-18) This invention relates to telephone switching networks, and particularly to the control ot such networks when adapted for use in electronic telephone switching systems. Telephone switching networks of the character related to the present invention comprise a number of switches arranged in stages to provide transmission interconnections between any one of a plurality of transmissi-on terminals at one side of the network and any one of a plurality of transmission terminals at the other side of the network. The switching network may in this manner be employed to connect a subscriber line corresponding to the terminal vat the one side of the network to a subscriber li-ne or trunk corresponding to the terminal at the other side of the network. The switches which are ultimately operated to establish each of the connections in the various stages of the transmission network to complete a desired transmission path conventionally comprise a coordinate array of crosspoints having an electrical contacting means at each of the crosspoints. Electrical contacting means which may be employed in a crosspoint switch to establish transmission path connections take various forms and a number of these are well known in the telephone switching art. Mechanical arrangements for operating the contacting means have proven highly useful in the past `and have been extensively employed. Electronic means such as gas tubes, for example, have also been employed for completing transmission path connections. This invention concerns itself paiticulanly with the control of those switching devices in which metallic contacts are actually operated, such as electromechanical relays having contacts associated therewith. Switching network arrangements using well known electromechanical relay means have long constituted the basic contacting means for selectively completing a telephone network transmission path in certain telephone systems. The time required for electromechanical relays to respond to energizing current pulses, however, has proven excessive in the context o-f high speed electronic switching systems. Accordingly, a need was created for an electrical contacting means which is operative responsive to el-ectrical pulses occurring at electronic speeds. A highly advantageous answer to this need, fulfilling the requirement of high operating speeds while retaining the advantages inherent in a mechanical switch, is the contacting device known yas a ferreed. One form o-f the ferreed is described in the patent of the present inventor, No. 3,037,085 issued May 29, 1962. This ferreed cornprises in its simplest form a pair o-f magnetically responsive electrical reed contacts associated with a magnetic structure having remanent magnetic properties. The ferreed is organized such that when a flux is induced in the magnetic structure in one direction by a current pulse applied to windings coupled thereto, the flux is closed through the electrical reed contacts themselves thereby causing their closure. The remanent properties of the structure maintain the contacts closed atter the energizing current pulse which induced the flux therein is interrupted. The contacts are opened .by a reverse current pulse applied to another winding, which current pulse causes a reverse flux which closes through another portion of the magnetic structure rather than through the 3,231,679 Patented Jan. 25, 1966 ICC reed contacts. The spring action of the reed contacts then causes their separation. The ferreed is thus wholly compatible with electronic telephone switching systems in which high speed ener- -gizing current pulses are applied to establish cross-point connections. Although a disparity still may exist between the response time of the reed contacts and the time duration of the energizing current pulses, the magnetic structure, which may advantageously be fabricated of a ferrite material, provides an ideal buffer between these two occurrences. A control flux is readily induced or switched in the structure responsive to high speed pulses and remains, or latches, to actuate the relatively slower operating contacts. The organization of the control windings of a Iterreed may advantageously be such that when both of two control windings are energized in either direction the reed contacts are closed and remain closed, the contacts being opened when either one but not both of the windings are energized. Such a winding arrangement is also described in detail in the patent of the present inventor referred to hereinbefore in detail and makes possible this differential excitation of ferreeds. When ferreeds operating in the differential excitation mode are arranged in a coordinate crosspoint switch, energizing control conductors Iarranged in both sets of coordinates defining the crosspoints serially include therein the respective winding means of the individual ferreeds. The contacts of each ferreed may be arranged to interconnect transmission conductors discretely associated with the energizing control conductors which define the crosspoint location of the ferreed within the coordinate crosspoint switch. To close the contacts of a 'ferreed at a selected crosspoint ot a switch, the two coordinate cont-rol conductors defining the selected crosspoin-t .are simultaneously energized. The contacts of the selected crossp-oint ferreed close in response to the energization of its two control winding means in its response time after the brief energizing current pulses are removed from the defining coordinate energizing conductors. When the differentially excited ferreeds are arranged in coordinate fashion, it is clear that each of the other ferreeds having a winding included in the control conductors will have only one of their two control winding means energized. In accordance with the differential excitation mode of operation, the contacts of cach ferreed of a coordinate switch appearing in the energized coordinate which were previously closed will be restored to their normally open state, leaving operated only the contacts of the selected crosspoint ferreed. This operation of a ferreed switch array has been termed destructive mark operation. In the destructive mark switch as described in the aforementioned Patent No. 3,037,085, the selected coordinate control conductors are separately although simultaneously energized from separate energizing pulse sources. A multistage network of lferreed switches may advantageously be made up having a plurality of switches in each stage and one such network arrangement is shown in the patent referred to in the foregoing. Considerably larger networks in which a more economical distribution of switches and their interconnecting links is realized may also be achieved using the ferreed as the basic electrical connecting means. In such larger networks, switching arrangements are provided which respond to signals from common control equipment which itself operates responsive to the subscribers service requests. When such -a common `control equipment is employed in connection with an electronic switching system, more economical and efficient distribution of network components is made possible and the flexibility of the switching system is greatly increased. In large switching networks of the the parallel transmission network to the next. 3 character contemplated the problem is presented of gaining access to the network itself and then controlling the network pulsing paths to establish the necessary transmission paths required by subscriber service requests. The network may also be required to perform various test yfunctions and also, advantageously, when malfunctions are detected, to perform its own clearing operations. When a lrelatively large number of transmission paths are to ybe controlled in a network, it has been found that -a signicant economic advantage may be realized by using electromechanical relay means to provide the access for control operations. Specifically, when wire spring relays are so employed the cost of a single relay Contact is small when com-pared to the cost, for example, of a semiconductor device which would be required to perform the same control path establishing function. It is an object of the present invention to provide a new and novel ferreed switching network, the access and control of which, although electronically controlled, are achieved by means of electromechanical relay means, 'thereby to realize improvements in network economy and flexibility not possible with prior switching networks. Another object of this invention is to provide a new and improved switching network compatible with electronic telephone switching systems. It is also an object of this invention to employ the bilateral electrical current properties of ferreed switching devices to provide a telephone switching network capable of performing a number of control operations with a minimum increase in network components. It is a further object of this invention to provide a ferreed switching network having relay means for selecting and establishing a control path therethrough. The foregoing and other objects of this invention are -realized in one speciiic illustrative embodiment thereof which employs the aforementioned ferreed electrical contacting devices as the -basic switching elements. As also mentioned previously, the ferreeds each have a pair of control winding sets coupled toa magnetic structure, both `control winding sets of which must be energized to effect the closure of the ferreed contacts. In one use of the ferreed in this invention, two reed spring contact sets are provided in each ferreed to establish a connection vbetween tip and ring transmission conductors from one stage of The basic crosspoint switch of the present invention is a coordinate array of such ferreeds. One of the control winding sets of each ferreed is connected in an energizing control conductor of one set of coordinates and the other control winding set of the same ferreed is connected in an energizing control conductor of the other set of coordinates. When a ferreed is operated, its contacts interconnect transmission conductors ofl the transmission network which are discretely associated with the energizing control conductors in which the windings of the ferreed are connected. A selected ferreed of the switch is then operated simply by coincidentally energizing the two coordinate control conductors defining the selected ferreed in the coordinate array. Obviously, and in accord with destructive mark operation, each of the other ferreeds occurring on the energized coordinate control conductors will have only one of the control winding sets energized and hence will be restored to the normal state causing its contacts to open if previously operated. Each of the ferreed crosspoint switches of this invention advantageously makes use of the connection in the switch of the output end of each of the coordinate control conductors of one set of coordinates with the input end of each of the coordinate control conductors of the other set of coordinates by means of a common conducting bus. This ferreed switch arrangement is described in the copending application of W. S. Hayward, Jr., Serial No. 206,055, tiled lune 28, 1962, now Patent No. 3,110,- 772 issued November l2, 1963. Since a somewhat rigor- `ous requirement of coincidence -both in time and amplitude exists for the energizing current pulses required to operate the ferreed devices employed in this invention, the common conducting bus connecting the ends of the coordinate control conductors of a switch advantageously solves this problem. Thus, by simultaneously applying a current pulse to a selected control conductor of one set of coordinates and a ground potential, for example, to a selected control conductor of the other set of coordinates, an energizing circuit is defined which will include both of the winding sets of the selected ferreed appearing at the crosspoint defined by the selected coordinates. Obviously, in -this manner the identical current pulse is applied to both winding sets of the selected ferreed. An absolute coincidence of time and pulse magnitude is thus insured. Before proceeding to the general organization of this invention, it may be noted that all references are to a switching control network as distinguished from the telephone transmission network which the switching control network is intended to control. Thus the switching control network will be understood by one skilled in the art to control, by means of the tip and ring contact pairs of the `ferreeds, transmission paths in a parallelling transmission network which may be, but is not necessarily, an image of the switching control network. However, since this invention concerns itself essentially with switching network control, the transmission network of a telephone system with which this invention may advantageously be adapted for use is not considered in detail herein nor is it fully shown in the drawing. The ferreed crosspoint switches of this invention are organized in grid units in which a plurality of switches on one side have their output coordinate control conductors connected by means of a plurality of interswitch links to input coordinate control conductors of lan equal plurality of switches on the other side of the grid. Coordinate transmission conductors discretely associated with the coordinate control conductors of the various switches may be interconnected by interswitch transmission conductors in a pattern similar to that of the interswitch links. Hereafter the term link is descriptive of a connection between coordinate control conductors, it being understood that interswitch transmission conductors may be provided in association with each interswitch link vfor connecting the coordinate transmission conductors associated with the coordinate control conductors connected by the interswitch link. The interswitch link connections `are such that each switch on one side of the grid has access at one of its output coordinate control conductors with each switch on the other side of the grid. An illustrative control network according to this invention is further developed by multiplying a number of such grids in both directions to make up a supergrid array of grids. Two columns of grids are contemplated with a plurality of grids in each column. In this super-grid arrangement of grids, it is apparent that =four columns of crosspoint switches will result, of which columns of switches in the present network will comprise the switching stages. `rl'he grids including the stage 1 and 2 switches and the grids including the stage 3 and 4 switches are interconnected by means of a plurality of intergrid links. The latter links connect the levels of the switches in such a manner that each ygrid of one column of grids has access to each grid of the other column of grids. Three sets of interstage links thus result which will be designated herein the A links, interconnecting `the switches of stages 1 and 2, the B links, interconnecting the switches of stages 2` and 3, and the C links, interconnecting the switches of stages 3 and 4. According to one feature of this invention each of the A, B, and C links has a relay contact included therein. The relay contacts of the links are associated with operating relays grouped according to'links in a manner vsuch that with the operation of selected relays in each of the groups corresponding to the A, B, and C links, a single conducting control path is established `from one side of a selected switch of the first stage switches to the other side of a selected switch of the last stage switches. Such a single conducting control path is made possible by the connections at each of the stages of the coordinate control conductors to the common conducting busses as previously described. At the first stage side of lthe network each of the input coordinate control conductors is connected to a line control conductor which has a relay contact included therein for making the subscriber line selection. At the last stage side of the network each of the output coordinate control conductors is connected to a trunk control conductor which has a relay contact included therein for making the selection of trunks leading out of the network. In the ferreed network being generally described, the transmission conductors outgoing Ifromy the last stage off the parallelling transmission path network, which is not a part of this invention, for completing calls between a calling subscriber substation and the central oiiice or a called subscriber within the same central office, are termed junctors. Thus, it will be appreciated by one skilled in the -art that the illustrative control network according to this invention being described may comprise only one part of a telephone system for responding to subscribers service requests. Other control networks which may be identical to the one contemplated herein may thus be employed in the system to control the completion of call connections. The first and second stages of the supergrid network of this invention comprise concentrator stages. The switches employed in the latter stages have their cross- -points arranged and the number of coordinate control conductors in each set of coordinates organized in a manner such that the number of incoming lines of the network is reduced by a predetermined factor at the output side of the second stage. In the illustrative embodiment of this invention being described, the number of lines incoming to the network are concentrated on a 4:1 basis. Specifically, the particular control network to beconsidered in detail hereinafter provides for the access of 4096 lines to 24 transmission conductors at the output of the second stage. It is also a feature of a control network according to the principles o-f this invention tha-t a ferreed is also connected in each of the line control conductors at the first stage of the network; contacts of this ferreed rnay for example `serve to disconnect, i.e., cut off, line supervisory circuits from the respective transmission conductors of the line circuits associated with the line control conductors. A special form of ferreed is employed a-t this point to provide for such cut-olf operations. The ferrreed is provided with a single Winding in order to achieve polar operation upon its selective energization. A current 1n one direction in the single winding thus serves to close the contacts of the polar cut-off ferreed and a current in the opposite direction opens the contacts. The polar ferreed of a particular line control conductor may be operated in conjunction with the exclusive control of the first stage switch to which the line control conductor is` connected. The common conducting bus of each of the rst stage switches itself provides an independent control circuit path by connecting thereto a shunt conductor leading to a potential source. The shunt conductor has also 1ncluded therein a relay contact selectively operable to provide a shunt path directly to the latter potential through a particular control conductor of one coordinate without at the same time including in the path a control conductor of the other coordinate. As a result, although a control circuit is completed for the polar cut-off ferreed, the first stage switch is effectively opened with respect to the ferreeds appearing therein on the coordinate control conductor completing the circuit for the polar iferreed. Particular network operations may thus be accomplished in which a number of operative combinations o-f the cut-off polar ferreed and first stage switches are involved. Since the lferreeds of the supergrid switches are operable by current pulses of either polarity, network operations requiring the opening of the contacts of the first stage switches with or without the operation of the cut-off polar ferreed contacts are made possible without the addition of components or circuits within the network itself. It is still another feature of this invention that at the junctor side of the network each of the junctor control conductors connected to the output coordinate control conductors of the last stage switches has one winding of a single ferreed Idevice connected thereto. The contacts of this ferreed may be advantageously used to connect a test circuit to the transmission conductors associated with a junctor control conductor. This ferreed device, also operated in the differential excitation inode, is connected to the junctor control conductors between the control network and the aforementioned junctor selection relay contacts. The junctor ferreed -advantageously provides for false, cross and ground testing of the particular network transmission path to which its contacts are connected. The bidirectional character of the current control paths dened through the supergrid iferreeds and the junctor ferreeds makes `possible a variety of network control and test operations with or without the selective operation of the cut-off polar ferreed contacts. According to yet another feature of this invention, each :of the line control conductors, shunt conductors, A, B, and C links, and junctor control conductors of the control network, in addition to a relay contact, has a fuse connected therein. A self-clearing operation in the event of a sticking selection relay contact is in this manner advantageously made possible. It will lbe appreciated that, in a control network of the character contemplated, if a selection relay contact sticks closed, the one link control path in which the malfunctioning contact appears will remain in a busy condition and cannot be restored to an idle condition merely by releasing the relay involved. This defective condition is obviously more serious than the case of a contact which refuses to close since a false control connection thus established will interfere with other control connections. When the ferreed energizing current pulse is applied to the control network, the current will divide between the control paths thus existing. In accordance with this feature, all of the selection relays of the links except those of the particular group of links to be tested are closed. A direct current, sufficiently low in magnitude not to disturb operated ferreeds, is then applied to all of the junctor control conductors at the junctor side of the net-work. Since, in the particular group of links being tested, each of the selection relay contacts will be open, if one ofthese contacts is stuck closed, all of the direct current will Ibe applied to the current path through the control network including the stuck contact. Although t'he testing current is of low magnitude, it is of sufficient duration to cause the Ifuse included in the latter path to melt, thus clearing the control path without in any way affecting the condition of the remaining control paths in the stage being tested. A subsequent continuity test may then be accomplished to isolate the now defective fuse and provide for its replacement and the correction of the stuck associated contact. Fuses of suitable characteristics may be provided to insure adequate operating margins. The foregoing and other objects and features of this invention will be better understood from a consideration of the detailed description of a specic illustrative network embodiment thereof which follows when taken in conjunction with the accompanying drawing in which: FIGS. l through 8 depict an illustrative telephone switching control network according to they principles of this invention; FIG. 9 shows t-he arrangement of FIGS. l through 8 to depict the control network organization; FIG. l0 depicts one ferreed crosspoint switch which may be employed as the basic electrical contacting means 7 within the illustrative control network proper and its attendant transmission path network; FIG. 11 depicts a comparison of varlous energizing pulses applied to the control network during various operations; 4 FIG." 12 depicts .the convention employed to represent relays and their associated make or break contacts; FIG. 13 depicts the connection of a typical ferreed crosspoint within a coordinate switch array. An illustrative control network according to the principles `of this invention may now 'be considered in detail with particular reference to FIGS. 1 through 8 of the drawing. The following description of such an illustrative network will comprise, first, the organization and structural arrangements of the control network, lfollowed by a'description of illustrative operations of the control network in accomplishing its various functions. The description of the structural organization of the control network will consider lirst the control network proper, its terminal circuitry, and interswitch link selection relay contacts, followed by a description of the various relay groups for controlling these and other contacts, the relay control circuits for accomplishing various network functions, and finally, general mention .of the external circuitry which may advantageously comprise part of the telephone system as a whole with which a control network according to this invention may be adapted for use. lBroadly, the network comprises a supergrid made up of a plurality of columns of grids of ferreed switches. The switches are in this manner arranged in four stages. The stage 1 and 2 switches are arranged in a plurality of grids of switches, which grids in the specific embodiment being described number sixty-four. The stage 3 4and 4 switches are also arranged in a plurality of grids, which grids number sixteen. For purposes of clarity the grids of the four stages will be designated A and C link grids hereinafter and, also to simplify the presentation in the drawing, only the last grid of each column of grids is shown in detail, the first and second representative grids v being shown only in Ablock symbol form. The rst column of grids of the network thus comprises a plurality of A link grids -1 through 20-64 and the second col-umn of grids of the network comprises a plurality of C link grids 30-1 through 30-16. The first two stages of the network are concentrator stages and the crosspoint arrangement of the ferreeds and the organization of the coordinate control conductors of the switches to achieve the required concentration is depicted in detail in the grid 20-64 shown in FIG. 2. Each of the concentrator grids 20-1 through 20-64 is organized with four first stage switches 21-1 through 21-4 and four second stage switches 22-1 through 22-4. yEach of the switches-211 through 21-4 comprises a partial access switch with sixteen input terminals at one side having access to four out of eight output terminals at the other side. Each of the switches 22-1 through 22-4 of the second stage comprises a switch having eight terminals at one side and four terminals at the other side. The organization of a first stage concentrator switch may be understood with particular reference to switch 21-1 of grid 20-64, for example. The switch 21-1 is provided with a plurality of input terminals m1 through m16 at one side connected to sixteen vertical coordinate control conductors of the switch. The latter control conductors are each connected at one end to a common conducting bus 23 in the manner described in detail in the copending application of Hayward, now Patent 3,110,772, mentioned hereinbefore. Eight horizontal coordinate control conductors are connected at one end also to the common conducting bus 23. In order toachieve concentration of the transmission paths, the individual ferreeds are arranged at the crosspoints of the switch 21-1 in a manner so that the transmission input paths corresponding to each of the terminals m may be connected via the ferreed contacts to any predetermined four of the eight transmission output paths corresponding to each of the terminals n; and the control windings are correspondingly connected between vertical and horizontal control conductors as shown in switch 21-1. Although any combinations of such connections may be devised by one skilled in the art, in the present illustrative embodiment, the terminals m are grouped by four such that the transmission conductors corresponding to any group of four terminals m may be connected to transmission conductors corresponding to a different combination of four horizontal conductors. These combinations of connections are represented in switches 21-1 and 21-4 in FIG. 2 by the encircled crosspoints of the switches, the ferreeds themselves being omitted for purposes of simplicity. The connection of the ferreed device of FIG. l0 in a typical crosspoint switch array is shown in FIG. 13. Although the complete ferreed switch 31-8, part of which is shown in FIG. 13, appears in FIG. 3, the connections of the various ferreed terminals in the other switches 21, 22 and 32 of FIGS. 2 and 3 are identical to those shown in FIG. 13. The reed contacts 51 and 52 interconnect the transmission conductors Tml, Rml and Tnl, Rnfl associated with the coordinate control conductors m1 and n1 respectively, when the ferreed device F11 is operated. In the switches 221 through 22-4 a further step in the concentration of the grids 201 through 20e64 is achieved as may be described in connection with an illustrative switch 22-1. Eight :horizontals of the latter switch have access to four verticals via the contacts of the individual ferreeds in this case provided at each of the crosspoints of the switch also as represented by encircled crosspoints only. The horizontal and vertical coordinate control conductors of the switch 22-1 are also connected at their ends, respectively, to a common conducting bus 23 in accordance with the switch described in the aforementioned Hayward application, now Patent 3,110,772. Continuing with a consideration of a representative grid of the first and second stages, the interconnections of the A links between the horizontals of the switches 21-1 through 21-4 of the grid 20-64 and the horizontals of the switches 22-1 through 22-4 of the same grid may be merely stated at this point as each containing a relay contact and a fuse. In addition, the A links at this point may be understood as being associated in pairs to achieve the interstage connections. The A links will be considered in further :detail hereinafter. It is to be vunderstood that each of the grids Ztl-I through 20-63 and their component ferreed switches are also organized in a manner identical to that described in connection with the representative grid Ztl-64. The third and fourth stages of the network of FIGS. 1 through 8 comprise a plurality of sixteen grids 30-1 through Sti-16. As depicted in detail in the representative grid 30-16, each of the latter grids is an octal grid having eight ferreed switches 31-1 through 31-8 in one of its stages and eight ferreed switches 32-1 through 328 in the other of its stages. Each of the ferreed switches of the latter stages is also organized on an octal basis, having eight vertical coordinate and eight horizontal coordinate control conductors. The respective ends of the control conductors lying on the coordinates are also connected to a common'conducting bus 23 in each of the switches. In the case of the third stage switches, eight terminals m1 through m8 are provided for each switch which are connected to the eight vertical coordinate control conductors. For the fourth stage switches, eight terminals nl through 118 connect to the eight horizontal coordinate control conductors. The provision at each of the crosspoints ofthe octal switches of the grid Sti-16 is again represented merely by the encircled crosspoints at these locations. lThe connection of a typical ferreed device F11 in a typical ferreed switch 31-8 is shown in FIG. 13. C links, the specific interconnection of which will be described hereinafter, also connect the horizontal coordinate control coriductors of the third stage switches with the horizontal coordinate control conductors of the fourth stage switches. Each of the interstage C links also has a relay contact and a fuse therein as will be considered in further detail hereinafter. It is to be understood that each of the other grids 30-1 through 30-15 and their component ferreed switches are also organized in a manner identical to that described in connection with the representative grid 30-16. The A link grids and C link grids are interconnected by means of B links in a manner such that each of the A link gri-ds has access to each of the C link grids. Although sixty-four A link grids are provided and only sixteen C link grids, a symmetrical interconnection of B links is made possible since, it will be recalled, the second stage of each of the A link grids is made up of four ferreed switches each having four outputs and the third stage in each of the C link gri-ds is made up of eight 'ferreed switches each having eight inputs. In the illustrative network lbeing described it is thus clear that 1024 aggregate terminals of the A link grids connect to 1024 aggregate terminals of the C link grids. With such an equal distribution of terminals of the A and C link grids, the terminals and their corresponding transmission conductors of an A link grid are successively connected, respectively, -to the terminals and their corresponding transmission conductors of the C link grids which correpond to the numerical position of the connecting A link grid in the column of A link grids. For example, the last terminal of the A link grid -64, which i-s the terminal n4 -of the switch 22-4, connects via a B link to the last terminal m8 of the last switch 31-8 of the last C link grid 30-16. The first terminal of the A link grid 20-64, which is the first terminal n1 yof the switch 22-1, connects via a B link 26 to the last terminal of the la-st switch of the first C link grid -1. Likewise, continuing this successive interconnection -of B links, the last terminal of the last ferreed switch of the second A link grid 20-2 connects via a B link 27 to the second terminal :of the last C link grid 3016, the latter terminal being the second terminal m2 of the first switch 31-1. The second terminal of the second A link grid Ztl/ 2 then connects via a B link 28 to the second terminal of the lC link grid Ztl-2. The first terminal of the second A link grid 20-2 connects via B link Z9 to the second terminal of the first C link grid 30-1. Further representative connections of B link-s between the second and third stage switches will finally serve to illustrate the B link organization. The first terminal of the first A link grid 20-1 is connected via .a B link 33 to the first terminal of the first C link grid 30-1 and the last terminal of the first A link grid 20-1 is connected via a B link 34 to the first terminal of the last C link grid 30-16. The second terminal of the first A link grid 20-1 is connected via `a B link 35 to first terminal of the second C link grid 302. From the toregoing representative B link connections it is clear that with each A link grid having sixteen outputs, access may be had to each of the sixteen C link grids. Conversely, since each of 4the C link grids has sixty-four terminals, access to these terminals may be had from each of the sixty-four A link grids. Each .of the B links, the representative ones 25 through 29, 33, 34, and 35 of which are shown in the drawing, also has a selection relay conta-ct and a fuse therein, which elements will be considered in greater detail hereinafter. The interconnections of the A links within ea-ch of the grids 20-1 through 20-64 is made in a manner similar to that described for the B links; that is, each of the switches 21-1 through 21-4 of the first stage has access Via its horizontal con-trol conductors to each of the switches 22-1 through 22-4 of the second stage. This interconnection may be understood with reference to the grid 20-64 shown in detail in FIG. 2. It may be noted, 'to avoid complexity of presentation. however, that, in distinction from the switches of the C link grids, the switches of each stage of the concentrator grids each have m-ore horizontal control cond-uctors than there are switches of the .other stage to which it Imay have access. Accordingly, the horizontal control conductors of the switches 21-1 through 21-4 are connected in pairs via pairs of A links to pairs of horizontal control conductors of the switches 22-1 through 22,-4. Specifically, the first two horizontal control conductors of 'the switch 21-1 are connected via a pair of A links, represented in FIG. 2 by ia representative link 36, to the first two horizontal control conductors of the second stage first switch 22-1. The seventh Iand eighth horizontal control conductors of the first switch 21-1 -of the grid 30-64, of that switch, respectively, which are the penultimate-'and last horizontal control conductors, `are connected via pair of A links represented by the link 37 to the -first and second horizontal control conductors of the second stage last switch 22-4. The first and second horizontal contr-ol conductors of the first stage last switch 21-4 are connected by a pair of A links 38 to the penultimate and last horizontal control conductors, respectively, of the second stage first switch 22-1 and the :penultimate and last horizontal cont-rol conductors of the switch 21-4 are connected via a pair of A links 39 to the penultimate and last horizontal con-trol conductor, respectively, Iof the second stage last switch 22-4. Thi-s sequence of interconnection is continued for the intermediate pairs of A links not shown in lthe drawing The pairing of A links `and their paired connections between terminals of the grids advantageously makes possible the Iuse of 8 x 4 switches in the second stage to achieve a correspondence of the number of horizontal control cond-uctors and their paralleling transmission conductors of the third stagel grids with the horizontal control conductors and their paralleling transmission conductors of the second stage grids. It is to be understood that each of the grids 20-1 through 20-63, not shown or shown only in block symbol form, has it switch interconnections made in a manner identical to that described in the foregoing for the grid 20-'64. Within each of the C link grids 30-1 through 3ft-16, the switch interconnections between switches are identical to that described between grids for the B links. Thus, within each C link grid, each of the switches 31-1 through 31-8 of the third stage has access, via one of its horizontal control conductors and a C link, with each switch within its grid of the fourth stage. Representative C links 40 through 43 are shown in FIG. 3 interconnecting representative horizontal control conductors of the switches of the grid 30-16. C link 40 thus connects the last horizontal control conductor of the third stage last switch 31-8 with the last horizontal control conductor of the last switch 32-8 of the fourth stage; C link 41 connects the first horizontal control conductor of the last switch 3].-8 with the last horizontal control conductor of the first switch 32-1; C link 42 connects the last horizontal control conductor of the first switch 31-1 with the first horizontal control conductor of the last switch 32-8; and finally, C link 43 connects the first horizontal control conductor of the first switch 31-1 with the first horizontal control conductor of the first switch 32-1. Intermediate C links not shown to avoid complexity similarly connect the intermediate horizontal control conductors of the third and fourth stage switches to achieve the required access pattern, and their interconnection may be determined by interpolation. It is also to be understood that each of the grids 30-1 through 30-15, not shown or shown in block symbol form only, is organized with respect to its interconnecting C links, in a manner identical to that described for the illustrative grid 30-16. The organization of an illustrative control network and its internal interconnections has thus been described, which network has 4096 line terminals at the first stage in 256 switch groups of sixteen m1 through m16 line terminals. The network also has 1024 junctor terminals at the fourth and last stage in 128 switch groups of eight terminals n1 through ng. Before proceeding to a description of the additional terminal circuitry for selecting a control path through the control network, the particular ferreed device contemplated for use as a crosspoint in the switches already considered will be described. Although the individual ferreeds may advantageously take the form of the differentially operating parallel ferreed shown and described in Patent No. 3,037,085 of the present inventor referred hereinbefore, any form of crosspoint switch operating in the coincident current excitation mode may be employed in the switches of a network according to this invention. One such alternative form of ferreed and one which is contemplated for use in the present network is the series ferreed shown in FIG. and is also described in the copending application of A. L. Blaha et al., Serial No. 124,723, filed July 17, 1961, now Patent 3,075,059 issued January 22, 1963. The ferreed of FIG. 10 comprises a slotted magnetic sleeve 50 of a material having substantially rectangular hysteresis characteristics through which are passed magnetically responsive reed contact members. Since the switching network ,of this invention provides for the simultaneous completion of tip and ring transmission circuits, two reed contact member pairs 51 and 52 are provided in the ferreed. A magnetically permeable collar 53 encircles the sleeve 50 at approximately its midpoint and opposite the contacts of the reed members 51 and 52 within the sleeve. A portion a of the sleeve 50 has a winding 54 and a winding 55 thereon and portion b of the sleeve 50 has a winding 56 and a winding 57 thereon. The Winding 54 is connected in series opposing with the winding 56 in an energizing circuit 58 and the winding 55 is connected in series opposing with the Winding 57 in an energizing circuit 59; the relative sense of these energizing circuits is opposite, so that for similar polarities of exciting currents, windings 54 and 55 will produce opposing magnetic fields, as will windings 56 and 57. The lon the simultaneous energization of the two sets of control windings 54-55 and 56-57, it will be assumed that a positive current pulse is applied simultaneously to each of the circuits 58 and 59, specifically, to the respective terminals of these circuits designated 60 and 61, repectively. From the sense of the larger windings 55 and 56 and the polarity of the applied energizing current pulse it will be apparent that a remanent magnetization will be induced responsive thereto in the sleeve 50 which is upward as viewed in the drawing. This magnetization will be equally distributed along the series portions a and b of the sleeve 50 and will find closure through the magnetic reed contact members 51 and 52 thereby effecting their closure. The energizing pulse will also be applied to the oppositely wound windings 54 and 57 thereby generating a counter magnetomotive force to the force inducing the foregoing magnetization. However, the number of turns of the latter windings is determined such that this magnetomotive force is overridden by the force generated in the windings 55 and 56 having a larger number of turns. Advantageously, t-he remanent properties of the sleeve 50 permit the flux induced therein to operate on the relatively slower responding reed contact members 51 and 52 after the energizing current pulse is removed from the terminals 60 and 61. These remanent properties also maintain the contacts of the reed members permanently closed without further expenditure of power. Release -of the contacts is accomplished by applying Van energizing current pulse to either one but not both of the energizing circuits 58 and 59. Assuming that a device F11. positive current -pulse is applied to only the circuit 58 at the terminal 61, a magnetomotive force in the upward direction as viewed in the drawing will be generated in the winding 56 and such a force in the downward direction will be generated in the winding 54. ln the portion b of the sleeve 50 to which the winding 56 is coupled, the magnetization is already upward as a result of the previously described operation, and accordingly no effective magnetic change takes place in this portion b. In the portion a, however, the previously induced magnetization is switched to the opposite direction. Since no energizing cunrent pulse is being applied at this time to the circuit 59, no magnetomotive forces counter to those just described are generated in the windings 55 and 57. The flux closure of the oppositely directed magnetizations as a result of the single applied current pulse will now be through the shunting collar 53 and through individual ones of the reed contact member pairs. As la result, the magnetic poles at the contacts of the members 51 and 52 will be alike, thus causing their separation. It is thus apparent that when only one of the energizing circuits 58 and 59 is energized, the portions a and b Will be left vwith opposing magnetizations, and in either case the contacts will open or remain opened. In actual practice the reed contact members of the ferreed device of FIG. 10 may advantageously be encapsulated in glass envelopes in order to provides contact protection. The series ferreed device of FIG. 10 is readily adapted to the coordinate crosspoint switches Ialready described herein in connection with the network portions of FIGS. 2 and 3 as shown in FIG. 13 by, for example, connecting the terminals 60 and 60a in series with an energizing control conductor in one of the sets of coordinates and by connecting the terminals 61 and 61a in series with an energizing control conductor in the other set of coordinates. The reed contacts 51 and 52 are connected between the transmission conductors T1111, Rm1 .and Thi, R111 associated with the respective coordinate control conductors m1 and nl which define the ferreed crosspoint When the crosspoint device F11 is operated, the transmission conductors T1111 and Rml vare connected to the transmission conductors T111 and R111 respectively by the contacts 51 and 52. It will be appreciated by one skilled in the art that still other forms of differentially excited and coincidentally operated electrical contacting devices may `be employed as a crosspoint device in the network of this invention. Further, a differentially excited and coincidentally operated ferreed such as de- -scribed in detail in the foregoing may also be employed to perform other and different functions in a switching network. Thus, as will be described hereinafter, the ferreed o-f FIG. 10 may advantageously be employed with virtually no modification in the control network of this invention in conjunction with performing the FCG testingof the paralleling transmission network. Returning to the description of the control network proper and particularly to the line Iside at the first stage thereof, the organization of the line selection circuits may now be considered. Each of the line terminals 1n of the grids 20-1 through Ztl-64 is connected via the winding of a polar cut-ofi ferreed 65, a fuse, and a line selection relay contact to a common conductor 66 by means of an individual line control conductor 67. The conductor 66 is connected through a pulse control relay contact to ground. Each of the common conducting busses 23 of each of the first stage switches 21-1 through 21-4 of each of the grids 20-1 through Ztl-64 is connected via a shunt conductor 68, a fuse, and a shunt relay contact to a common conductor 69, which latter conductor is in turn connected to ground through another pulse control relay contact. 'l'lhe speciiic design-ations of the relay contacts so far mentioned, including those referred to as being included in the interstage connecting links together with the associated fuses, and the organization of the polar cut-off fer-reeds will be considered in detail hereinafter in conjunction with the description of the selection relays with which the contacts are associated and `the control of the cut-oil ferreeds. At the junctor side of the netwoork each of the junctor terminals n of the switches of the fourth stage are connected via a junctor control conductor 70, one of the winding sets of `an FCG ferreed 71, a junctor selection relay contact, and a fuse to a common conductor 72, which latter conductor is in turn connected through one pulse control rel-ay contact to ground and through another pulse control relay contact to pulsing conductor 199. The ferreeds 71 may advantageously each comprise a ferreed device identical to that depicted in FIG. 10. One of the Winding sets of .a ferreed 71 is connected in series with a junctor control conductor 70 and the other winding set of each of the ferreeds 71 is connected in a common conductor 73 individual to a C link grid. The contacts of a ferreed 71 may be arranged to connect a test circuit to the transmission conductors `associated with a junctor control conductor 70 when the ferreed 71 is operated. One end of each of the common conductors 73 associated respectively with the C link grids is connected to the conductor 72. The other end of each of the common c-onductors '73 is connected via la no-test selection relay contact and a fuse to a common conductor 74. The latter conductor is connected via la pulse control relay contact and a resistance 75 to a source of positive potential 76. It will Ibe apparent from the illustrative control network of FIGS. l through 8 so far described, that by closing a 'selected relay contact in each of the A, B, and C links one exclusive ser-ies control path may be established in the control network between any one terminal m at the line side of the network and any one terminal n at the junctor side of the network. Thus, starting at the right side of the network as viewed in FIG. 3, such an exclusive control path may be traced from a selected n terminal, a vertical coordinate control conductor of a switch of the fourth stage, one tot the control winding sets of -a crosspoint ferreed, `a common conducting bus 23, a horizontal coordinate control conductor of the same switch, the other control winding set `of the same ferreed, a C link via its ruse and C link selection relay contact, a horizontal coordinate control conductor of a third stage switch, one of the control winding sets of a crosspoint ferreed, common conducting Vous 23 of the same switch, a vertical coordinate control conductor, the other control winding set of the same ferreed, to a terminal m of the third stage switch. The exclusive control path is then continued via a B link, control winding sets of a crosspoint ferreed of a second stage switch, `an A link and the control winding sets of a crosspoint ferreed of the irst stage to a terminal m of an A link grid at the line side of the network. The exclusive series control path thus traceable may obviously be extended in both directions from the control network proper. Thus, at the line terminal -side of the control network, the series control ypath may be further traced via the winding of a Ipolar ferreed 65, a fuse, a line selection relay contact, yand a line control conductor 67 to ground by means of the common conductor 66 and `a pulse control relay contact. At the junctor side of the network the exclusive control path may be further extended to the common conductor 72 via `a fuse, a junctor selection relay contact, one of the control winding sets of Ia ferreed 71, and a junctor control conductor 70. In addition to the exclusive series control paths available through the control network as above illustrated, other such control paths are also available at either end of thecontrol network. At the line terminal side of the network, for example, an alternative control pat-h is available which may be traced via the winding of a polar ferreed and a first stage switch alone. Starting at the common conductor 66, such a control path follows a line control conductor 67, a line selection relay contact, fuse, and terminal m to a vertical coordinate control conductor of a switch or" the first stage. At this point the latter control path is traced through the common conductor bus 23 of the same switch, a shunt conductor 68, fuse, and a shunt relay contact to the common conductor 69. Alternatively, the latter control path may be .traced from the latter common conducting bus 23 and a horizontal coordinate control conductor of a switch of the first stage to continue its series path through the control network as previously described. Still another series control path may be traced from a horizontal coordinate control conductor of a first stage switch to its common conducting bus 23 and then directly to a connected shunt conductor 68, in this manner bypassing the vertical coordinate control conductors. At the junctor side of the network a number of alternative circuits may also be traced. Thus, for example, a series control path extended through the control network itself may be traced therefrom either through a single control winding set of a ferreed 71 and thus to the common conductor 72, or through both control winding sets of a ferreed 71 via the common conductor 72 and a control conductor 73 to the common conductor 74. Each of the various series control paths so fa-r mentioned is employed in performing various transmission network control operations as controlled by the operation of their associated control path selection relays. These relays and their contacts, which have so far only been gene-rally referred to, and their energizing circuits may'now be considered in detail. The energizing circuits of the relays will he grouped in general in accordance with particular operations of the control network. In FIG. 5 are shown the groups of relays required to select and establish the various series control paths through the control network and its terminal circuitry generally described in the foregoing. The groups of relays and their associated contacts will rst be catalogued before considering in detail the circuits required for their control. The relays are group in accordance with the particular segments of the series control paths through the control network which they selectively established. Beginning at the line side of the network it will be recalled that each of the conducting busses 23 of the first stage switches is connected in a shunt circuit controlled by a shunt relay contact via a shunt conductor 68. A plurality of sixty-four relays S1 through S64, each having four contacts associated therewith, control establishment of these shunt circuit control paths. Each of the relays S1 through S64 is assigned to an individual A link grid and has one of its relay contacts connected in a shunt conductor 68 of a switch of its assigned A link grid. Specifically, the relay S1 assigned to the grid 20-1 has associated therewith and controls the contacts Sl-l through S1-4 connected in the four shunt conductors 68 of the four first-stage switches of the latter grid. The relay S2 has associated therewith and controls the contacts S2-1 through S2-4 connectedin the four shunt conductors 68 of the four lirst-stage switches of the grid 2li-2. This association of relays is continued with their contacts in the shunt conductors 68 to the last grid Ztl-64. At that point the relay S64 controls the contacts 564-1 through 864-4 connected in the tour shunt conductors 68 of the lirst-stage switches 21-1 through 21-4. Each of the shunt relay contacts Sl-l through 864-4 has associated therewith a fuse fs also connected in its respective shunt conductor 68. Each of the relays S1 through S64 is connected at one side to a source o-f potential 75 and at the other side to a one-out-of-sixty-four selector switch 76. Line selection at the line terminal side of the network is performed by a plurality of sixty-four relays L1 through L64 each having sixty-four contacts associated therewith. Each of the relays L1 through L64 has a line selection contact connected by means of a line control conductor 67 to a line terminal m of each of the grids Ztl-1 through 20-64. For example, the first contacts L1-1 through L64-1 of the relays L1 through L64, respectively, are connected in the line control conductors 67 connected through the windings of polar ferreeds 65 to the successive line terminals m1 through m15 of each of the switches of the A link grid 20-1. The second contacts L1-2 through L64-2 of the relays L1 through L64, respectively, are connected in the line control conductors 67 which in turn are connected through the windings of polar ferreeds 65 to the successive line terminals m1 through m16 of each of the switches of the A link grid 20-2. This successive assignment of line selection contacts is continued in this manner through the grids 20-3 through 20-63. At the grid 20-64, the last contacts L1-64 through L64-64 of the relays L1 through L64, respectively are connected, as shown in greater detail in the grid 20-64. to the successive line terminals of the first-stage switches 21-1 through 21-4. Specifically, the contacts L1-64 through L16-64, for example, are connected through windings of polar ferreeds 65 to the line terminals m1 through m16 of the switch A21-1. The line terminals m1 through m16 of the last first-stage switch 21-4 are connected through windings f polar ferreeds 65 tol the contacts 1.49-64 through L64-64, respectively. Each of the line selection relay contacts L1-1 through L64-64 also has associated therewith a fuse fl. Each of the relays L1 through L64 is connected at one side to a source of potential 77. At the other side the latter Irelays are connected to a oneout-of-sixty-four selector switch 178. At the latter side the relays are also connected, respectively, to ground through a plurality of relay contacts LL-1 through LL-64, the purpose of which will be considered hereinafter in describing particular functions of the present control network. Control path selection between the first and second stages, that is, the selection of the A links, is performed by a plurality of eight relays A1 through A8 each having associated therewith 256 contacts. The relays A1 through A8 are distributed among the A link grids in a manner such that, with respect to each A link grid, successive relay contacts of an odd and even numbered relay pair are alternated successively for the A link pairs within the grid. Since there are eight relays A1 through A8, and four switches within each of the stages of the A link grids, these relays are assigned in pairs to horizontal control conductors of the first-stage switches. Within any A link grid, the first two relays A1 and A2 are assigned to the odd and even horizontal control conductors, respectively, of the first first-stage switch; the second two relays A3 and A4 are assigned to the odd and even horizontal control conductors, respectively, of the second firststage switch; the third two relays A5 and A6 are assigned to the odd and even horizontal control conductors, respectively, of the third first-stage switch; and the last two relays A7 and A8 are assigned to the odd and even horizontal control conductors, respectively, of the fourth firststage switch. This distribution of A link relay contacts may be further demonstrated with respect to the A link grid Ztl-64 shown in detail in FIG. 2. In the first firststage switch 21-1 of that grid, for example, relay A1 controls four contacts A1-253 through A1-256 in the first, third, fifth, and seventh horizontal control conductors and relay A2 controls four contacts A2-253 through A2-256 in the second, fourth, sixth, and eighth horizontal control conductors. This distribution may be continued to the last switch 21-4 of the grid 20-64 where the relay A7 controls four contacts A7-253 through A7-256 in the first, third, fifth, and seventh horizontal control conductors and relay A8 controls four contacts A8-253 through A8-256 in the second, fourth, sixth, and eighth horizontal control conductors. By means of this relay contact distribution a positive discrimination is obtained between the two links of the A link pairs within an A link grid. Each of the A link relay-contacts associated with the relays A1 through A8 has associated with it, within its A link a fuse fa. The A link relays A1 through A8 are each connected at one side to a source of potential 79. At the other side the latter relays are connected to a one-out-ofeight selector switch 80. At the latter side the relays are also connected, respectively, to ground through a plurality of relay contacts AA-1 through AA-S, the purpose of which will also be considered hereinafter. B link selection between the second and third stages of the network of FIGS. 1 through 8 is performed by a plurality of sixteen relays B1 through B16 each having associated therewith sixty-four contacts. The relays B1 through B16 are distributed among the terminals m of the C link grids in a manner such that the two relay groups B1 through B8 and B9 through B16 have their contacts assigned to alternating C link grids. The first contacts of each of the relays B1 through B8, for example, are connected to the terminals m1 through m8 of the first third-stage switch of the C link grid 30-1. These contacts are designated B1-1 through B8-1, respectively. With respect to the last third-stage switch of the grid 30-1, the contacts B1-8 through BS-8 of the relays B1 through B8, respectively, are connected to the terminals m1 through ma. Proceeding to the second C link grid 30-2, the relays B9 through B16 have their respective contacts 1 through 8 connected to the terminals m1 through m8 of each of the switches of that grid. Thus the contacts B9-1 through B16-1 of the relays B9 through B16, respectively, are connected to the terminals m of the first third-stage switch of the grid 311-2; the contacts B9-2 through B16-2 of the relays B9 through B16, respectively, are connected to the terminals m of the second third-stage switch of the grid 31h-2; etc. This distribution may be continued by interpolation to the last thirdstage switch of the grid 30-2 where the contacts B9-8 through B16-8 of the relays B9 through B16 are connected respectively to the switch terminals m. Proceeding in this alternate manner of assigning the relay groups B1 through B8 and B9 through B16 to adjacent C link grids to the last grid 3h0-16, the assignment of relays B9 through B16 and their relay contacts at the latter grid with respect to the detailed showing of the switches 31-1 and 31-8 is as follows: the contacts B9-57 through B16-57 of the relays B9 through B16, respectively, are connected to the terminals m1 through m8 of the first third-stage switch 31-1, respectively, and the contacts B9-64 through B16-64 of the relays B9 through B16, respectively, are connected to the terminals m1 through m8 of the last third-stage switch 31-8, respectively. The intermediate connections of the contacts of the relays B1 through B16 in the B links in each of the C link grids may readily be determined by interpolation from the representative contacts shown and described. Each of the B link relay contacts associated with the relays B1 through B16 has associated with it, within its B link, a fuse fb. The B link relays B1 through B16 are each connected at one side to a source of potential 81. At the other side the latter relays are connected to a one-out-of-sixteen selector switch S2. At the latter side the relays B1 through B16 are also connected, respectively, to ground through a plurality of relay contacts BB-1 through BB 16, the purpose of which will become apparent hereinafter. Control of control path selection via the C links between the third and fourth stage switches is had by means of a plurality of sixty-four relays C1 through C64, each having sixteen contacts associated therewith. The relays C1 through C64 are assigned by groups to pairs of the C link grids 30-1 through 30-16 with the contacts of the relay groups successively assigned to the successive C links connected to the switches of the third stage. In the first C link grid 30-1 the contacts C1-1 through C1-8 of the relay C1 are connected to the horizontal control conductors of the first third-stage switch of this grid, the contacts C2 1 through C2-8 of the relay C2 are connected to the horizontal control conductors of the second third-stage switch of this grid, the contacts C3-1 through C3,8 of the relay C3 are connected to the horizontal control conductors of the third third-stage switch of this grid, etc. This contact assignment is continued to the eighth and last third-stage switch of the grid Sil-1 with connection to the horizontal control conductors of this switch of the contacts C8-1 through CS-S of relay C8. In the next C link grid 3,0-2 of the first pair of C link grids, contacts C11-9 through C1-16 of the relay C1 are connected to the horizontal control conductors of the first third-stage switch o f this grid, contacts C2i-9 through C2-16 of relay C2 are connected to the horizontal control conductors of the second third-stage switch of this grid, and so on to the eighth and last third-stage switch of this grid. At the latter switch of the grid 302 contacts C8-9 through C8-16 of the relay C8 are connected successively to its horizontal control conductors. This distribution of successive contacts of the same relay group to adjacent pairs of the C link grids is continued throughout the column of C link grids. At the last two C link grids 30-15 and 3016 for example, the successive contacts of the relay group C57 through C64 are connected to the horizontal control conductors of their third-stage switches. Specifically, the contacts C57-1 through C57-8 are connected successively to the horizontal control conductors of the iirst third-stage switch of the grid 30-15, the contacts CSS-1 through CSS-S are connected successively to the horizontal control conductors of the second third-stage switch of the grid `30-1f5, etc. The contacts C64-1 through C64-8 are then connected'successively to the horizontal control conductors of the eighth third-stage switch of the grid 3045. In the last grid 30-16, this distribution of contacts is continued with the connection of the contacts C57-9 through C57-16 of the relay C57 to the horizontal control conductors of the `switch 31-1 shown in detail in FIG. 3, At the last switch 31-8 of the latter grid, contacts C64-9 through C64-16 of the relay C64 are successively connected to its horizontal control conductors. Each of the C link relay contacts associated with the relays C1 through C64 has associated with it within its C link a fuse fc. The C link relays C1 through C64 are each connected at one side to a source of potential 8,3. At the other side the latter relays are connected to a one-out-of-sixty-four selector switch 8.4. At the latter side the relays C1 through C64 are also connected, respectively, to ground through a plurality of relay contacts CCI through CC64, the purpose of which will be described in detail hereinafter. Junctor selection at the junctor s ide of the control network is accomplished by a plurality of sixty-four relays J1 through 164 each having sixteen contacts associated therewith. Each of the relays J1 through 164 has a junctor selection contact connected by means of a junctor control conductor 70 to a junctor terminal n of each of the grids 30-1 through 30-16. For example, the rst contacts 11-1 through 164-1 of the relays 11 through 164i, respectively, are connected ,in the junctor control conductors 70 connected through the FCG ferreeds 71 to the successive junctor terminals n1 through ng of each of the fourth-stage switches of the C link grid 30-1. The second contacts 11-2 through 1 6442 of the relays 11 through 164, respectively, are connected in the junctor control conductors 70 of the successive junctor terminals nl through n@ of each of the fourth-stage switches of the C link grid 30-2. This successive assignment of junctor selection contacts is continued in this manner through the grids 3ft-3 through 30-15. At the grid 30-16, the last contacts 11-16 through 164-16 of the relays 11 through 164, respectively, are connected, as shown in greater detail in the grid 30-16, to the successive junctor terminals of the fourth-stage switches 32-1 through 32-8. Specifically, the contacts J1-16 through 18-16, for example, are connected via the junctor control conductors 70` to the terminals nl through ng of the switch 32-1. The junctor terminals n1 through ns of the last fourth-stage switch 32,-8 are connected through their respective junctor control conductors 7 0 to the contacts 157-16 through 164-16, respectively. Each of the junctor selection relay contacts 11-1 through 164-16 has associated therewith and also included in its junctor control conductor 70 of fuse fj. Each of the relays 11 through 164 is connected at one side to a source of potential 85. At the other side the latter relays are connected to a one-out-of-sixty-four selector switch 86. At the latter side the relays are also connected, respectively, to ground through a plurality of relay contacts 11-1 through L11-64, the purpose of which will also be considered hereinafter. One final group of relays is provided to select a series control path through the control network proper. A plurality of sixteen no-test relays N1 through N16 each having a single relay contact associated therewith control the energizing paths through one of the control Winding sets of the FCG ferreeds 71. The relays N1 through N16 are assigned to the C link grids 30-1 through 30-16, respectively. Thus, the single contacts N1-1 through N16-1 of the relays N1 through N16 are included in the energizing conductors 73 of each of the latter grids and thereby control the control paths through the latter conductors 73 to the common conductor 74 in turn leading to an energizing source. Each of the no-test relay contacts N1-1 through N16-1 has associated with it and also included in its conductor 73 a fuse fn. Each of the relays N1 through N16 is connected at one side to source of potential 87. At the other side the latter relays are connected to a oneoutofsixteen selector switch 88. At the latter side the relays are also connected, respectively, to ground through a plurality of relay contacts NN-1 through NN-16, the purpose of which will become apparent hereinafter. The designation of the foregoing relays as no-test derives from an operation not described in connection with the present control network and the designation is employed only for the sake of consistency when the network is considered in a wider telephone system context. In the foregoing description of control path selection relays and their contacts, in each .case only a single relay with its contacts is described and shown in the drawing. It will be appreciated by one skilled in the art that such a single relay is assumed for purposes of simplicity of description only and in actual practice la number of relays may be ganged and operated simultaneously to accommodate, in some cases, the larger number of contacts to be controlled. In the actual practice of a control network according to this invention any suitable form of relay may be employed. In view of the considerable number of contacts associated with the relays, .the well-known wire spring relay was found particularly advantageous and economical. The contacts of each of the relays so far described are make contacts and are shown in the drawing in accordance with conventional detached relay contact practice as depicted in FIG. 12. The selector switches 76, 78, 80, 82, 84, 86, and 88 referred to in the foregoing and the'mlanner lin which these switches are controlled will be considered in detail hereinafter. In the foregoing the relays have been described, the selective operations of which control and establish the series of segments of a single series control path through Vthe control network and its terminal circuitry. Before proceeding to a description of the energizing circuits for selectively operating the above relays, two additional groups of relays and their contacts will be considered. The first of these is effective selectively to steer the ferreed, energizing current pulses to the various control paths establishable in the control network and its terminal circuitry by the relays already described, The second group of relays is employed in the novel self-clearing operation of the control network according to this invention. In the rst group of relays mentioned in the foregoing, nine pulse control relays K1 through K9, shown in FIG. 6, have single contacts distributed at various points thro-ughout the network and its terminal circuitry. In the portions thereof so far described, for example, contact K1-1 of the relay K1 is connected in the common conductor 69 at the line terminal side of the network controlling its access to ground. Similarly, the contact K2-1 of the relay K2 is connected in the common conductor 66, also at the line terminal side of fthe network, controlling the access of the latter conductor to ground. At the junctor side of the network, the contacts K8-1 and K9-1 of the relays K8 and K9, respectively, are connected between the conductor 72 and ground, and between the conductor 74 and the resistor 75 with potential source 76, respectively. The remaining contacts of the relays K3 through K7 will be most conveniently described in connection with the address and relay selection circuitry to be considered hereinafter. Each of the relays K1 through K9 is connected at one side to a source of potential 89 and at its other side to an energizing conductor 90. The second of the relay groups, shown in FIG. 8, which is the relay group operated for performing the selfclearing operation mentioned above, comprises a plurality of six clear relays LL, AA, BB, CC, Il, and NN, The relay LL has sixty-four contacts LL-l through LL- 64 associated therewith. The latter contacts are included in auxiliary energizing circuits, respectively, for each of the relays L1 through L64 previously described and shown in FIG. 5. The relay AA has eight contacts AA-1 through AA-S associated therewith, which latter contacts are included in auxiliary energizing circuits, respectively, for each of the relays A1 through A8 also shown in FIG. 5. The relay BB has sixteen contacts BB-l through BB-16 associated therewith, which latter contacts are included in auxiliary energizing circuits, respectively, for each of the relays B1 through B16 of FIG. 5. The relays CC and JJ each have sixty-four contacts associated therewith. The contacts CC-1 through CC-64 are included in auxiliary energizing circuits for the relays C1 through C64, respectively, and the contacts .IJ-1 through .TI-64 are included in auxiliary energizing circuits for the relays .I1 through 164, respectively. The relay NN has sixteen contacts NN-1 through NN-16 associated therewith, which contacts are included in auxiliary energizing circuits for` the relays N1 through N16, respectively. Each of the latter relays is also shown in FIG. 5. Each of the clear relays shown in FIG. 8 is connected at one side to a source of potential 91 and at its other side to an energizing conductor 92. Each of the contacts of the relays depicted in FIGS. and 6 are also make contacts and each of the contacts and its relay are shown in the conventional detached relay contact presentation as were the selection relays previously described. Only single relays are shown in FIGS. 5 and 8 and it is also to be understood with respect to these relays that a number of relays may be ganged in each case to accommodate the considerable number of contacts operated. Returning at this point to the various control circuits for selectively operating the control path selection relays already described, the relay control circuits for selecting and establishing a series control path through the control network responsive to a Connect order Will first be considered. In order to establish such a control path, a line terminal, A link, B link, C link, and junctor terminal are selected. Connect order circuitry for operating Athe various relays for selecting these control path segments connects selected ones of these relays to ground through its selector switch. In the Connect order circuitry each of the selector switches 78, 80, 82, 84, and 86 is connected via common conductors 93 -through 97 to corresponding selection conductors 10() through 104, respectively. The latter selection conductors are connected respectively through a plurality of make Connect order relay contacts CO1-1 through COI-5 to a common ground conductor `to ground. The latter relay contacts are associated with a relay CO1 the energizing circuit of which terminates at one end on ground. The energizing circuit of the relay CO1 is completed at its other end via a conductor 107 which extends to a network controller circuit to be considered hereinafter. The selector switches 78, 80, 82, 84, and 86 may each comprise any well-known tree selector switch, or other form of selector switch capable of steering an energizing current pulse through a branching network under the control of address information signals applied thereto. Such selector circuit arrangements are well known in the art and accordingly, since they do not per se comprise inventive aspects of this invention, the selector switches are shown in block symbol form only. The foregoing selector switches receive address instructions via a plurality of address conductors 108 through 112 which extend -to an address register of the network. Two other relays CO2 and CO3 are also operated during a Connect order operation of the control network; however these are more logically considered in connection with the circuitry for applying the actual ferreed energizing current pulses. Circuits for establishing a series control path through the network and its terminal circuitry for a Connect order may thus be traced to energize a selected one of each of the relays L1 through L64, A1 through A8, B1 through B16, C1 through C64, and J1 through 164 as follows: from ground at the common ground conductor 105, make contacts CO1-1 through CO1-5, selection conductors 100 through 104, common selector conductors 93 through 97, through the respective selector switches 78, 80, 82, 84, and 86, to the potential sources of the above-mentioned relays as selected by address signals transmitted to the selector switches via the address conductors 108 through 112, respectively. The next network operation, the control circuits of which will be described, is the Restore order for restoring supervision after a call has been completed. As will become apparent hereinafter, this network control operation involves only the switches of the rst stage and the shunt selection circuits connected thereto. Accordingly, as depicted in FIG. 7, circuits are provided for setting up control path segments in these portions of the control network. The selector switches 76 and 78 associated with these portions of the network are extended to the Restore order control section by means of a conduc-tor 113 and the conductor 93 previously described. Ground for selected relays of the selector switches 76 and 78 is extended via a common conductor 114, two make relay contacts R01-1 and R01-2, two selection conductors 115 and 116, and thereby through the respective conductors 113 and 93. The contacts RO1-1 and R01-2 are controlled by a Res-tore order relay R01, one side of which is connected to ground. The energizing circuit for the relay R01 is completed via a conductor 118 to network controller circuits, Energizing paths from ground for a selected relay of the relay groups S1 through S64 and L1 through L64 as selected by address signals transmitted -to the selector switches 76 and 78 via address conductors 119 and 108 may be traced as. follows: from ground via the common conductor 114,. relay make contacts R01-1 and R01-2, selection conductors 115 and 116, and thereby through the respectivel conductors 113 and 93 through the selector switches 76 and 78, respectively, to the potential sources 75 and 77 of the selected relays. Two other relays of this relay control circuitry are also of interest. However, since these relays R02 and R03 are operative only during the actual application of a ferreed energizing pulse, they will be more logically considered in conjunc-tion with a description of the circuits for steering the latter enel:- gizing current pulse. 21 l, The next relay control circuitry to be considered is that for preparing the transmission network for a false cross and ground test. In this operation, ferreeds in the second, third, and fourth stages and an FCG ferreed are operated, switches in the rst stage are to be left released and the cut-olf ferreed left unchanged from its previous condition. In order to accomplish this selection operation one of the shunt selection relays S1 through S64, one of the A link selection relays A1 through A8, one of the B link selection relays B1 through B16, one of the C link selection relays C1 through C64, one of the junctor selection relays J1 through 164, and one of the no-test selection relays N1 through N16, are operated. The control circuit for selectively operating one relay of each of these relay groups comprises selector switches 76, 80, 82, 84, 86, and 88. Address control for the latter selector switches is extended from the network controller previously mentioned via the address conductors 119, 109, 110, 111, 112, and a conductor 120. Ground is extended through the foregoing selector `switches for the selected relays via the conductors 113, 94, 95, 96, 97, and a conductor 121, respectively, which are extended to FIG. 7. The paths to ground are then continued respectively by means of the selection conductors 122 through 127, relay make contacts FCGl-l through FCG16 included in the respective latter conductors, and a common conductor 128. The relay make contacts FCG1-1 through FCG1-6 are controlled by an FCG relay FCGl, which relay is connected at one side to ground and at the other side is extended via a conductor 130 to the network controller previously mentioned. Two other relays FCG2 and FCG3 are also included in this control circuitry and their operation will be considered hereinafter. One other transmission network control operation which involves the same selection relays as were described in connection with the Connect order control circuitry is special service request simulation. In this operation the cut-E ferreed stage is active as are each of the network proper stages. 'Ihe FCG ferreeds, on the other hand, are released. Accordingly, paths to ground for the selected relays are provided through the selector switches 78, 80, 82, 84, and 86 under the control of their associated address conductors Via the common conductors connected to these selector switches previously described and which are now extended to FIG. 8. The latter conductors terminate at a plurality of selection conductors 131 through 135 which in turn are connected through a plurality of respective relay make contacts SR1-1 through SR1-5 to ground via a common ground conductor 136. The latter relay contacts are controlled by a relay SR1 which is connected at one side to ground and is extended via a conductor 138 to the previously mentioned network controller. Two other relays SR2 and SRS also comprise a part of the control circuitry being described and these will be considered in conjunction with their operation hereinafter. Paths to ground for the selected relays of the foregoing selector switch groups may be traced along the conductors 93 through 97, selection conductors 131 through 135, relay contacts SR1-1 through SR1-5, respectively, to the ground conductor 136. In the foregoing network control circuits described, each of the various relay contacts through which ground is extended is a make contact. In these control circuits the concern has been with establishing an exclusive series control path through the control network and its terminal circuitry. Combinations of the selector switches of FIG. 5 were involved in making this exclusive control path selection. In the nal control network operation to be described hereinafter, the control path selection contacts are tested for any which may have stuck closed and the control path segment including such a contact is opened. For this purpose each of the stages and the terminal circuits of the control network are sequentially tested by closing all of the contacts of all of the latter stages except the contacts of the stage under test. The relay contacts in each of the auxiliary ground circuits of the path selection relays, such as, for example, the contacts LL-l through LL-64, AA-l through AA-8, etc., are provided for this purpose. These contacts are controlled by the relays shown in FIG. 8. The latter relays, LL, AA, BB, CC, JJ, and NN are connected to ground via their energizing conductors 92 through respective break contacts CTI-1 through CT6-1 and a common ground conductor 140. The latter contacts are controlled by a plurality of respective relays CTI through CT6, one end of each of which `is connected to ground and the other ends of which relays are connected via a plurality of conductors 142 to the previously mentioned network controller. The common ground conductor is connected to ground at two points: at one point the connection is made through a relay make contact CL-l of a clear relay CL and at the other point the `connection is made through a relay make contact CLS-1 of a clear shunt relay CLS. The relays CL and CLS are connected at one side to ground and are extended via respective conductors 145 and 146 to the previously referred to network controller. Other contacts of both of the latter relays are connected in conductors the purpose of which will be described. The description of the control path selection relay energizing circuits so far has concerned itself only with the selection and establishing of the series control paths through the control network and its terminal circuitry without mention of the circuits for directing energizing current pulses and potentials to these paths for performing the various transmission network control operations generally mentioned. It will be recalled that the pulse control relays K1 through K9 actually performed the operation of steering current to various parts of the control network for the performance of its various transmission network control functions. Various combinations of the latter relays are operated simultaneously with the selection relays already described and accordingly control circuits for the relays K1 through K9 are included in each of the selection relay control circuits described and traced in the foregoing. The description will thus return to each of these circuits to pick up the control of the pulse control relays K1 through K9 for actually apphing the ferreed energizing current pulses and potentia s. Returning now to the Connect order control circuits of FIG. 5, four conductors 147 through 150 are seen to extend ground from the ground conductor 105 of FIG. 5 to the relays K2, K5, K6, .and K7, respectively, of FIG. 6, through relay make contacts CO2-1, CO2-2, CO2-3, and C03-1, respectively. The CO2 relay contacts are controlled by a relay CO2 connected at one side to ground and at the other side to a conductor 152 extended to the network controller mentioned previously. The conductors 147 and 148 are also connected to the ground conductor 105 via a pair of secondary conductors 153 and 154, respectively, having respective relay make contacts 154, respectively, having respective relay make contacts C03-2 and C03-3 therein. The latter relay contacts and the contact C03-1 are controlled by a relay CO3 which is connected at one side to ground and at the other side to a conductor 156 extended to the abovementioned network controller. In the Restore control circuits, the relays K1, K3, K6, and K7 are connected to the ground conductor 114 of FIG. 7 via a plurality of conductors 157 through 160, respectively, having included therein` the relay make conacts RO2-1 through RO2-3 and RC3-1. The latter conductors are extended to the respective relays in FIG. 6 Via a cable 157. The latter relay contacts are controlled by relays R02 and R03 connected at one side to ground and at the other side to energizing conductors 163 and 164, respectively, which latter conductors are also extended to the previously mentioned network controller. The conductors 157 and 158 are also connected to the 23 ground conductor 114 by means of secondary ground conductors 165 and 166, respectively, having therein relay make contacts RO32 and ROS-3 of the relay R03. During the false cross and ground test only the K relays K1, K4, K6, and K7 are operated and accordingly the source of potential 89 is connected to ground through each of these relays via a plurality of conductors 167 through 170 extended to FIG. 6 via a cable 167', which conductors in turn are connected to the ground conductor 128 of FIG. 7 through a plurality of relay make contacts FCG2-1 through FCG2-3 and FCG3-1, respectively. The latter relay contacts are controlled by relays FCG2 and FCG3, which relays are connected at one side to ground and at the other side to energizing conductors 173 and 174, respectively, which latter conductors are also extended to the previously mentioned network controller. The conductors 167 and 169 are also connected to the ground conductor 128 by means of secondary ground conductors 129 and 171, respectively, having therein relay make contacts FCG3-2 and FCG3-3 of the relay FCG3. In the Service request test relay control section of FIG. 8 control is afforded relays K3, K6, K7, and K8 via conductors 175 through 178 extended to FIG. 6 via a cable 175 which conductors are each connected at one end to the respective energizing conductors 90 of the latter relays. The conductors 175 through 178 are connected at the other ends to the common ground conductor 136 of FIG. 8 through a plurality of relay make contacts SR2-1 through SR2-3 and SRS-1, respectively. These contacts are controlled by the relays SR2 and SR3 which relays are connected at one side to ground, respectively, and are connected at the other side to energizing conductors 181 and 182 which extend to the previously mentioned network controller. The conductors 175 and 177 are also connected to the ground conductor 136 by means of secondary ground conductors 137 and 179, respectively, having therein relay make contacts SRS-2 and SRS-3 of the relay SRS. Particular ones of the K relays of FIG. 6 are also operated during the contact test and clearing operation of the control network. The relays K2 and K9 are controlled during this operation by means of a pair of conductors 183 and 184, respectively, of FIG. 8 extended to the latter relays via a cable 183', which conductors extend ground to the latter relays from the rst secondary ground point of the ground conductor 140. The conductors 183 and 184 have included therein relay make contacts CL-2 and CL-3 controlled by the relay CL previously described. During this same test and clear operation but at a different time, the yrelays K1 and K9 are simultaneously'operated. Control of the latter relays is had by means of a pair of conductors 185 and 186, respectively, which are extended to the latter relays via a cable 185 and which conductors extend ground to the latter relays from the second secondary ground point of the ground conductor 140. The conductors 185 and 186 have included therein relay make contacts CLS-2 and CLS-3 controlled by the relay CLS also previously described. The relays K1 through K9 operate to control contacts already specied in the portions of the network and its terminal circuitry. However, these relays also operate other contacts in control conductors extending to external instruction circuits which do not comprise a part of this invention and which may now be generally considered with particular reference to FIG. l. External control for providing instruction and address signals for the network so far described may advantageously be provided by means of a number of circuit means devisable by one skilled in the art. Such circuit means are well known and one exemplary combination of circuits for providing the instruction and address signals required to control the various control circuits described hereinbefore is depicted in FIG. 1. Since such circuits are well known and comprise noninventive associated components external to the control network which cornprises the present invention, they are shown in block symbol form only. The external circuitry is thus identied only to the extent of specifying the character of the outputs required to render the control network of this invention operable. As was mentioned earlier herein, the control network of this invention is not contemplated as being operative directly responsive to subscriber dial pulses. In order to simplify the control of the network, direct control is provided by a common control of the telephone switching system of which the present control network may be adapted for use. This common control is then operated responsive to` the subscriber dial pulses. The telephone lsystem common control controls, in the exemplary system being described, a network controller 191 which operates under instructions from the common control to supply the various energizing pulses, to be more specifically identiiied, at the proper times. An address register 192, also under the control of instructions from the system common control 190, provides coded signals and their translation to make the necessary selection of the selection relays within the selector switches 76, 78, 80, 82, 84, 86, and 88. The network controller 191 provides control for a control path continuity check circuit 193 and also for a pulse source 194. This control is provided via a pair of conductors 195 and 196, respectively. The continuity check circuit 193 may comprise any suitable circuit readily devisable by one skilled in the art capable of detecting opens and other circuit resistance change-s and this circuit is accordingly also shown in block symbol form only. The pulse source 194, similarly shown, may comprise any suitable circuit capable of providingpulses at the times and of the character to be more specifically described. The pulse source 194 is connected through a pair of relay make contacts K7-1 and K51 via a conductor 197 extended through FIGS. 2 and 3 directly to the common conductor 72 of FIG. 4. The continuity check circuit 193 is connected through a pair of relay make contacts K6-1 and K3-1 via a conductor 198 directly to the common conductor 66 shown in FIG. 1. The conductors 197 and 198 are connected together between their respective relay contact pairs by means of a bridging conductor 199. The latter conductor is connected through a relay make contact K4-1 via a conductor 200 extended through FIGS. 2 and 3 to the common conductor 74 of FIG. 4. The network controller 191 also provides control signals for each of the network control operations. Thus, select, check and energize signals are provided for the conductors 107, 152, and 156, respectively, of the Connect order control circuits, which conductors are extended to the network controller 191 via a cable 201. Select, check and energize signals are also provided for the conductors 118, 163, and 164, respectively of the Restore control circuits, which conductors are extended to the network controller 191 via a cable 202. In the FCG test control circiuts the network controller provides select, check, and energize signals for the conductors 130, 173, and 174, respectively, thereof, which conductors are extended to the network controller 191 via a cable 203. Similarly, select, check, and energize signals are provided by the network controller 191 to the conductors 138, 181, and 182 of the Service request test control circuits, which conductors are extended to the network controller 191 via a cable 204. Finally, instruction signals are provided by the network controller 191 for the Contact Test and Clear control circuit. Specically, control signals are provided for the conductors 142 and 145 which are extended from the network controller 191 via a cable 205 and for the conductor 146 which also extends t0 the network controller, 10. A MULTISTAGE TELEPHONE SWITCHING NETWORK HAVING IN EACH OF ITS STAGES A PLURALITY OF ARRAYS OF CROSSPOINT DEVICES, EACH OF SAID ARRAYS HAVING INPUT AND OUTPUT SETS OF COORDINATE CONTROL CONDUCTORS; AND COMPRISING CONDUCTING MEANS FOR EACH OF SAID ARRAYS CONNECTING THE INPUT AND OUTPUT SETS OF COORDINATE CONTROL CONDUCTORS OF SAID ARRAY; A PLURALITY OF INTERSTAGE CONTROL LINKS INTERCONNECTING SAID OUTPUT SET OF COORDINATE CONTROL CONDUCTORS OF EACH OF THE ARRAYS OF ONE STAGE WITH THE INPUT SET OF COORDINATE CONTROL CONDUCTORS OF EACH OF THE ARRAYS OF A SUCCEEDING STAGE; A PLURALITY OF RELAY CONTACTS CONNECTED RESPECTIVELY IN SAID INTERSTAGE CONTROL LINKS; AND A PLURALITY OF RELAY MEANS FOR CONTROLLING RESPECTIVELY SAID PLURALITY OF RELAY CONTACTS SUCH THAT A CONTINUOUS AND UNIQUE SERIES CONTROL PATH IS ESTABLISHED BETWEEN ANY COORDINATE CONTROL CONDUCTOR OF SAID INPUT SET OF AN ARRAY OF THE FIRST STAGE OF SAID PLURALITY OF STAGES AND ANY COORDINATE CONTROL CONDUCTOR OF SAID OUTPUT SET OF AN ARRAY OF THE LAST STAGE OF SAID PLURALITY OF STAGES.

1962-06-28

en

1966-01-25

US-48578083-A

Electron gun with improved cathode and shadow grid configuration ABSTRACT An improved electron gun is shown with a cathode having a smooth, concaved surface and a grooved pattern therein which matches, and is aligned with, the pattern of a shadow grid placed immediately before the cathode surface so that the outer, larger radius of curvature of the shadow grid closest to the cathode is substantially identical and concentric with the radius of curvature of the smooth, concave cathode surface. Beyond the shadow grid is a control grid which controls the flow of electrons emitted from the cathode toward an anode. The grooves which form the pattern within the cathode surface have tapered side walls and rounded outer and inner corners to improve the flow of emitted electrons and facilitate manufacture. The present invention relates to an improved electron gun and, more particularly, to a cathode and grid configuration which improves the flow of electrons by utilizing a grooved cathode surface, grooved to match the configuration of the shadow grid immediately adjacent thereto. BACKGROUND OF THE INVENTION It is well known in the art to utilize an electron gun within a traveling-wave tube (TWT) or other charged particle device such as a linear accelerator, a free electron laser, a switch tube or a crossed-field tube. A TWT, in particular, is a broad-band, microwave tube which depends for its characteristics upon interaction between the electric field of a wave propagated along a wave guide and a beam of electrons traveling with the wave. In this tube, the electrons in the beam travel with velocities slightly greater than that of the wave, and, on the average, are slowed down by the field of the wave. Thus, the loss in kinetic energy of the electrons appears as an increased energy conveyed by the field to the wave. The TWT therefore, may be used as an amplifier or as an oscillator. The electron gun which forms the heart of the TWT is typically formed with a cathode and anode between which are disposed grids. An electron gun showing such an arrangement may be found in prior U.S. Pat. No. 3,558,967, issued Jan. 26, 1971, by George V. Miram. The Miram patent utilizes a control grid and a shadow grid having the same pattern for the purpose of selectively blocking electron flow from the cathode to the control grid thereby preventing excessive heating of the control grid by electron bombardment. The shadow grid placed adjacent to the cathode causes distortion of the electric fields. This creates electron trajectories in the beam of electrons flowing from the cathode toward the anode to cross over one another and diverge from the desired laminar flow. Such crossing trajectories create serious heating problems when the stray electrons strike parts of the microwave tube structure downstream from the electron gun. The Miram reference overcomes this defocusing problem by either imbedding the shadow grid within the cathode or recessing the shadow grid in a recessed pattern within the surface of the cathode. When the shadow grid is imbedded within the cathode, the result is a serious shortening of the cathode life due to the poisoning of the cathode by the contacting grid or due to grid emission resulting from migration of the emissive material onto the grid. The second Miram solution is to recess the grid in a noncontact manner within square cornered grooves in the surface of the cathode. In either solution that the Miram reference teaches, the spacings are impractically small. These small spacings provide less than optimum electron optics. Furthermore, the Miram reference teaches the need for relieving the surface of the cathode to form dimples between the recessed shadow screen. These dimples, or secondary concaved surfaces, are intended to form tiny beamlets which are ultimately focused into a single unitary linear beam after passage through the shadow and control grids. One disadvantage of forming dimples, or secondary concaved emitter surfaces, within the concaved surface of the cathode is the added fabrication steps required. Further, each dimple must be symmetrical about its center. Thus, the pattern of the shadow grid and accompanying control grid or grids is needlessly complicated in order to match the symmetry of the dimpled pattern. This requires tighter grid tolerances and creates alignment problems. Finally, the pattern of grooves on the cathode surface is unnecessarily complex and difficult to manufacture. After the suggested use of an imbedded shadow grid, Miram taught the use of a spherically-concaved and dimpled cathode surface, together with a pair of axially-spaced, spherically-concaved, focus-and-control grids in his coinvention, U.S. Pat. No. 3,983,446, which issued Sept. 28, 1976. Other U.S. patents which show grooved control grids may be found in U.S. Pat. No. 3,500,107 which issued Mar. 10, 1970, by J. E. Beggs and U.S. Pat. No. 2,977,496 which issued Mar. 28, 1961 by H. D. Doolittle. These patents show a grooved, spherical, cylindrical or flat-surfaced cathode, respectively. Except for the flat-surfaced cathode shown in the Beggs patent, the curved cathode surfaces are each shown with secondary curved surfaces that are difficult to machine or otherwise fabricate. A copending patent application, Ser. No. 362,790, filed Mar. 28, 1982, by Richard B. True, entitled Improved Dual-Mode Electron Gun, assigned to the same assignee as the present invention, shows the use of a smooth, concaved cathode in a dual-mode electron gun. However, this reference used a shadow grid with two distinct patterns of conductive elements and a varying potential to accomplish its dual-mode function. It does not teach an improved cathode and shadow grid configuration. SUMMARY OF THE INVENTION Accordingly, it is the object of the present invention to provide an improved electron gun which eliminates the dimpled cathode and provides a more laminar flow of electrons emitted from the cathode toward the anode. Another object of the invention is to provide an improved electron gun with a simplified cathode surface which is more easily fabricated than prior art cathodes. A further object of this invention is to create an improved groove configuration within the cathode surface and a simplified relationship between such grooves and the shadow grid. In accomplishing these and other objects, there is provided an improved electron gun having a smooth, single-concaved, electron-emitting surface disposed in juxtaposition with an anode between which is mounted a pair of grids. The first grid adjacent to the smooth, single-concaved surface is a shadow grid which is formed with a pattern of conductive elements and which is aligned with a control grid upon which is also formed a substantially similar pattern of aligned, conductive elements. The smooth, single-concaved surface of the cathode is relieved by a plurality of grooves which matches the pattern of the shadow and control grids. The outer surface of the shadow grid is substantially aligned with the emitter surface of the cathode. By utilizing the grooved pattern behind the shadow grid, the laminar flow of electrons from the cathode is improved. Using this arrangement, it has been found that it is unnecessary to dimple the concaved, electron-emitting surface of the cathode, as in the prior art. DESCRIPTION OF THE DRAWINGS Further objects and advantages of the present invention will become apparent after consideration of the following specification and accompanying drawings, wherein: FIG. 1 is a cross-sectional, schematic view of an electron gun showing the improved cathode and shadow grid configuration of the present invention; FIG. 2 is a detailed schematic representation, shown in cross-section, illustrating the present invention; FIG. 3 shows a plot of current density across the surface of the cathode of the present invention; FIG. 4 is a schematic representation, shown in cross-section, similar to FIG. 2 showing a prior art electron gun; FIG. 5 is a plot of current density across the surface of the cathode shown in FIG. 4, similar to FIG. 3; FIG. 6 is a schematic representation, shown in cross-section, of another prior art cathode and shadow grid arrangement; FIG. 7 is a detailed cross-sectional view showing the interrelationship between the shadow grid and the cathode of the present invention; FIG. 8 is a cross-sectional view illustrating the flow of an electron beam from a segment of the grooved cathode of the present invention; and FIG. 9 is a cross-sectional view illustrating the flow of an electron beam from the prior art cathode of FIG. 4. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, FIG. 1 shows an electron gun 10 having an anode 12 and a cathode assembly 14. The cathode assembly 14 consists of a thermionic cathode dispenser 16 provided with a smooth, single-concaved, electron-emitting surface 18 which is heated by an encapsulated heating coil 20. The encapsulated heating coil 20 nests within a counterboard aperture in dispenser 16 that, in turn, mounts within a conductive collar 22 which fits snugly within a mounting housing, not shown. Mounted upon the outer end of a housing ring 24 is a shadow grid 44 which may be manufactured by photoetching or electrical-discharge machining a thin, preformed sheet of molybdenum, hafnium, or an alloy of copper and zirconium sold under the trade name of Amzirc. The shadow grid, in the preferred embodiment, is 0.003 inches thick. The relationship between the shadow grid 44 and the cathode surface 18 is shown in greater detail in FIGS. 2, 7 and 8. A focusing electrode 26 whose annular opening 28 is disposed between the cathode 16 and anode 12 is mounted within the housing, not shown. Mounted between the focusing electrode 26 and ring 24 is a second ring 30 having a toroidal shape with an inner surface upon which is mounted a control grid 56 formed in a manner similar to the formation of shadow grid 44. Control grid 56 fits concentrically within the spherically-shaped shadow grid 44. Each of the grids 44 and 56 are provided with circular conductive elements 58, FIGS. 2 and 7, which are connected to one another by radiating conductive elements 60. It will be understood that the grids, 44 and 56, may be formed in several configurations within the preferred embodiment. That is, the grids may be constructed by arranging conductive elements into a particular pattern or by placing apertures within a conductive sheet leaving the remaining material to form the conductive elements of the grids. It will also be understood that the shadow grid 44 is arranged between the cathode 16 and the control grid 56 to prevent the electrons emitted from surface 18 of cathode 16 from striking the control grid 56 and thus heating the control grid. Therefore, in most embodiments, the pattern of the shadow grid 44 and control grid 56 is identical. However, this is not necessary within the teachings of this invention. Nor is this invention limited to a single control grid, as two or more such grids are often used. In operation, electrons escape from the smooth, concaved surface 18 of cathode 16 and pass through the grids 44 and 56 to be accelerated toward a tapered annular opening 62 with the anode 12. The electrons are thus formed into a beam "b" by the action of the control grids 44 and 56, the focusing electrode 26 and the anode opening 62. As seen in FIG. 2, the smooth, concaved surface 18 of the electrode 16 is provided with a plurality of grooves 64 which are arranged in a pattern identical to the pattern of the shadow grid 44. Grooves 64 are machined or etched into the surface 18 of cathode 16 and provide a region of greatly reduced (negligible) electron emissivity which, in combination with the conductive element 58 of the shadow grid 44, acts to produce a laminar flow of electrons from the surface 18 of cathode of 16. It will be seen in FIGS. 2 and 7 that the conductive elements 58 and 60 which form the shadow grid 44 are spherically shaped with an outer surface radius 66 that is equal to the radius of curvature of the cathode surface 18. Further, the shadow grid 44 is arranged so that its outer radius lies substantially in the same plane as the radius of curvature of surface 18. In a preferred embodiment, this line-to-line configuration provides for the smoothest flow of emitted electrons. However, it will be understood that the exact location of the shadow grid 44 may be varied so that the grid 44 is actually recessed within groove 64 or placed just outside of the radius of curvature which forms the concave surface 18. FIG. 3 shows a plot of calculated current density across the surface 18 of cathode 16. The maximum current density has been determined to equal 7.1 amps/cm2 when the voltage upon the shadow grid 44 is zero volts and the voltage upon the control grid 56 is 350 volts, as shown in FIG. 2. Referring now to FIGS. 4 and 5, a comparison is made between the improved cathode and shadow grid configuration of the present invention, FIG. 2, and the prior art, FIG. 4. In the prior art, the cathode 416 has a spherical surface 418 which includes a plurality of dimpled, or secondary spherical surfaces 419. The shadow grid 444 is spaced apart from the surface 418 of the cathode while the control grid 456 is aligned behind the shadow grid. FIG. 5 shows a plot of the current density across the surface of the cathode 416. In the prior art, the shadow grid 444 is maintained at zero volts while the control grid is maintained at 450 volts. In this configuration, the maximum current density across the face of the cathode is 8.5 amps/cm2. It should be noted that the present invention permits the control grid 56 to be operated at a lower voltage than prior art arrangements, while the cathode peak loading is also lower. The effect of reducing the cathode peak loading for the same cathode current is that the cathode may be operated at a lower temperature resulting in a longer life expectancy than in prior art arrangements. As mentioned above under the Background Of The Invention, another prior art arrangement, FIG. 6, includes the concept of placing the shadow grid 644 within grooves 664 in the spherical surface 618 of the cathode 616. This prior art arrangement also utilized a control grid 656 having the same pattern as the shadow grid 644. While the prior art taught the utilization of grooves 664 within the surface 618 of cathode 616, the prior art still required the use of dimples 619, or secondary-concaved surfaces, across the concaved surface 618. The present invention has discovered that the dimpling of surface 618 is no longer necessary to obtain a smooth laminar flow of electrons from surface 618 of the cathode. Referring now to FIG. 7, the details of the grooves 64 in cathode 16 and conductive elements 58 of the shadow grid 44 are shown. It will be noted that the grooves 64 are not square-sided grooves, as shown in the prior art. Rather, the grooves have rounded upper and lower corners with tapered side walls to provide an improved flow of electrons, as shown in FIG. 8. The outer radius 66 of the shadow grid 44 is substantially aligned with the radius of curvature of the concaved surface 18 of cathode 16. It will be seen that the 0.003 inch element 58 is square and aligned symmetrically over a 0.003 inch deep groove whose inner side is 0.005 inches long and whose outer side opening is 0.007 inches long. While the exact dimensions of the groove configuration may be varied, the preferred groove configuration is shown. FIG. 7 shows the smooth, concaved surface 18 of cathode 16. However, as discussed below, a second dimpled surface 64, shown by a single dashed line 68, may be used. Alternately, a second convexed surface, shown by the dashed line 70, may be used. Referring now to FIG. 8, electron flow from the cathode surface 18 past grids 44 and 56 toward the anode 12 is shown through the utilization of a computer plot which simulates such flow in a small segment of the electron gun 10. In FIG. 8, the generally horizontal lines represent a computer plot of the electron current as the electrons flow from the cathode surface 18 toward the anode 12. The y axis shows the distance in centimeters of the individual conductive elements 58 which form the shadow grid 44 and control grid 56 from the plane of symmetry, while the x axis shows the distance in centimeters from the cathode surface. By comparing FIGS. 8 and 9, one can readily see the improvement in the laminar flow of electrons between the cathode and anode as they pass by the control and shadow grids. In FIG. 8, the present invention is illustrated showing the smooth, concaved surface 18 of the cathode 16 relieved by grooves 64 wherein the conductive elements 58 of shadow grid 44 are aligned with their outer radius substantially matched with the radius of curvature of the cathode surface 18. It will be seen from the diagram that the root-mean-square (RMS) of exit angles from the cathode surface is 0.5 degrees. When comparing this with the prior art arrangement shown in FIG. 9, which is a plot of the configuration of FIG. 4, one can see that the flow of electrons emitted from the cathode surface 418 past the shadow grid 444 and control grid 456 is more turbulent than in FIG. 8. In fact, the RMS of the exit angles is 1.4 degrees compared to 0.5 degrees in FIG. 8. It should also be noted that the electrons emitted behind the shadow grid carry more of the total current in FIG. 9 than in FIG. 8. The calculations indicate that 0.4% of the total cathode current is emitted behind the shadow grid 444 (shown by dashed lines) in the conventional gun shown in FIG. 9, while but 0.3% of the total cathode current is emitted behind the shadow grid 44 (also shown by dashed lines) in FIG. 8. The improved arrangement of FIG. 8 permits the control grid to be operated at a lower voltage and the cathode to be operated at a lower peak loading than their counterparts shown in FIG. 9. The lower peak cathode loading, as mentioned above, improves the life of the electron gun by lowering the required cathode operating temperature. The voltage used within the present embodiment maintains the anode 12 at a 25 kilovolt potential above the cathode 16. Obviously, other voltages may also be used. Note, that FIGS. 8 and 9 show a fictitious anode voltage of 1000 volts and 1100 volts, respectively, to simulate the electric field generated by the anode voltage of 25 kilovolts for computational purposes. The shadow grid 44, of the present embodiment, is maintained at 0 volts above the cathode, while the control grid 56 is 350 volts above the cathode potential. The electron gun of present embodiment may be operated between 1 kilovolt to 65 kilovolts. In this case, the shadow grid 44 remains at 0 volts while the control grid 56 may vary proportionally between 14 volts and 910 volts. A review of FIG. 8 in the area of the rounded and tapered surfaces of the groove 64 will illustrate how the rounded corners and tapered side walls aid the laminar flow of electrons emitted from the grooved cathode surface 18. These rounded and tapered surfaces are also more practical to manufacture than sharp square surfaces. The exact configuration of groove 64 and the depth at which the shadow grid 44 is inserted into the groove or placed above the groove may vary within the teachings of the present invention. The preferred arrangement is an aligned configuration. Another major importance of the shaped grooves 64 of the present invention is that they reduce the cathode current behind the shadow grid 44 and produce more uniform current density between the grooves. This increased uniformity reduces the peak cathode loading which in turn, allows the cathode temperature to be reduced and tube life prolonged. While the cathode surface 18 is a smooth, concave surface in the preferred embodiment, it has been found that the surfaces between conductive elements 58 may be convexed in some configurations for defocusing the flow of electrons. In this arrangement, the spreading flow is refocused by the control grid 56, which in some embodiments, improves the focus of the resultant beam. In other arrangements, the rounded and tapered surfaces of grooves 64 work well with dimpled surfaces between the elements 58, as in the prior art. The control grid 56 may be formed from more than one grid, as in a dual mode electron gun. Further, it is possible that in some applications, the shadow grid 44 may be formed from more than one grid. While other variations are possible, the present invention should be limited only by the appended claims. We claim: 1. An improved electron gun, comprising:an anode; a thermionic cathode having a smooth, single-concaved, electron-emitting surface; a control grid having a pattern of conductive elements; a shadow grid having a pattern of conductive elements; said smooth, single-concaved surface of said cathode having a grooved pattern therein which matches and is aligned with and under the pattern of said shadow grid, wherein said grooved, smooth, single-concaved surface of said cathode promotes the linear flow of electron from said electrons emitting surface around said shadow and control grids into a linear beam toward said anode. 2. An improved electron gun, as claimed in claim 1, wherein:said control grid is at least one control grid; said shadow grid is at least one shadow grid; and at least a portion of said at least one shadow grid pattern of conductive elements substantially matches at least a portion of the pattern of conductive elements of said at least one control grid and is aligned therewith. 3. An improved electron gun, as claimed in claim 1, wherein:said shadow grid and control grid have spherical radii of curvature which substantially match the spherical radius of curvature of said smooth, single-concaved surface of said cathode. 4. An improved electron gun, as claimed in claim 1, wherein:said shadow grid is recessed into said grooved pattern in said smooth, single-concaved surface of said cathode. 5. An improved electron gun, as claimed in claim 1, wherein:said shadow grid has an outer surface radius; said smooth, single-concaved surface of said cathode has a radius of curvature which is equal to said outer surface radius of said shadow grid; and said outer surface radius of said shadow grid is arranged in substantial line-to-line alignment with said radius of curvature of said smooth, concaved surface wherein said grooved pattern prevents contact therebetween. 6. An improved electron gun, as claimed in claim 1, wherein:said shadow grid is mounted slightly beyond said grooved pattern in said smooth, single-concaved surface toward said control grid. 7. An improved electron gun, as claimed in claim 1, additionally comprising:means for applying a voltage between 1 kilovolt to 65 kilovolts between said anode and said cathode; means for applying a positive voltage between 14 volts to 910 volts to said control grid compared to said cathode; and means for maintaining said shadow grid at zero voltage compared to said cathode. 8. An improved electron gun, as claimed in claim 7, wherein:said voltage applied between said anode and said cathode is 25 kilovolts; and said voltage applied to said control grid is 350 volts. 9. An improved electron gun, as claimed in claim 1, wherein:said grooved pattern within said smooth, concaved cathode surface is formed from grooves having tapered side walls and rounded inner and outer corners, wherein said linear flow of electrons from said cathode toward said anode is improved. 10. An improved electron gun, comprising:an anode; a cathode having an inner radius of curvature which forms a smooth, concaved, electron-emitting surface; said concaved surface having a pattern of grooves across said surface, each groove having rounded inner and outer corners; a first grid having a pattern of conductive elements which match, and are aligned with, said pattern of grooves in said cathode surface mounted adjacent to said cathode surface; a second grid having a pattern of conductive elements which substantially match, and are aligned with, said first grid mounted adjacent to said first grid; wherein said grooves reduce the amount of electron current emitted from said cathode surface behind each conductive element of said first grid and increase the uniformity of electron current density emitted from said cathode surface between said grooves. 11. An improved electron gun, as claimed in claim 10, wherein:said grooves within the surface of said cathode having tapered side walls. 12. An improved electron gun, as claimed in claim 10, wherein:said first grid has an outer surface radius that equals said inner radius of curvature of said concaved cathode surface and which is substantially aligned therewith, wherein said grooves prevent contact of said first grid and said cathode surface and reduce cathode current therebetween. 13. An improved electron gun, as claimed in claim 10, additionally comprising:means for applying a voltage between 1 kilovolt and 65 kilovolts between said anode and said cathode; means for applying a positive voltage between 14 volts and 910 volts to said control grid compared to said cathode; and means for maintaining said shadow grid at a zero voltage compared to said cathode. 14. An improved electron gun, as claimed in claim 13, wherein:said voltage applied between said anode and said cathode is 25 kilovolts; and said voltage applied to said control grid is 350 volts. 15. An improved electron gun, comprising:an anode; a cathode having a generally concaved surface; said concaved surface having a pattern of grooves across said surface; said grooves having rounded inner and outer corner and tapered side walls; a shadow grid having a pattern of conductive elements which match and are aligned with said pattern of grooves in said cathode surface mounted adjacent thereto; a control grid having a pattern of conductive elements which substantially match and are aligned with said conductive elements of said shadow grid mounted adjacent thereto; wherein said grooves reduce the amount of cathode current between said grooves and aligned conductive elements of said shadow grid. 16. An improved electron gun, as claimed in claim 15, additionally comprising:said generally concaved surface of said cathode in a smooth surface. 17. An improved electron gun, as claimed in claim 15 additionally comprising:said generally concaved surface of said cathode has secondary convexed surfaces between said grooves. 18. An improved electron gun, as claimed in claim 15, additionally comprising:said generally concaved surface of said cathode has secondary concaved surfaces between said grooves. 19. An improved electron gun, as claimed in claim 15, additionally comprising:said generally concaved surface of said cathode having a radius of curvature; said shadow grid having an outer surface radius generally equal to said radius of curvature of said cathode surface is substantially aligned with said outer surface radius of said electron gun.

1983-04-18

en

1986-04-15

US-29642394-A

Fire barrier ABSTRACT A fire barrier for use in dynamic voids to seal against the spread of fire. Flexible barrier material is suspended below a lazy tong arrangement spanning the void while the edges of the barrier material are biased against the walls of the joint to provide the necessary seal. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to fire barriers for use in voids formed in buildings, and more particularly, pertains to systems that continue to maintain an effective barrier against the spread of fire despite a substantial relative displacement or distortion of the surfaces that define such voids. 2. Description of Related Art A variety of dynamic voids or joints are typically incorporated in a building in order to prevent damage as the structure undergoes movement due to thermal, wind and seismic loads. In order to prevent the spread of heat, smoke, and flames therethrough, such voids must be fitted with fire barriers. It is especially important for a fire barrier fitted to a joint to remain in tact after the joint has undergone substantial displacement or distortion due to seismic activity, as the risk of fire is especially high immediately following an earthquake. Various barrier systems have been devised that attempt to accommodate the magnitude of movement anticipated during a seismic event. A substantial widening and/or narrowing of a seismic joint can be expected, while lateral or shear displacement on the order of several feet is not unusual. Fire barriers typically consist of a sheet of flexible material that is attached to each wall of the joint and loosely draped therebetween. Such configuration does not in any way impede the narrowing of the gap while the slack in the material accommodates a widening of the gap beyond its nominal width. Any differential vertical displacement between the two sides of the joint, is similarly compensated for by the flexible material. In order to prevent failure of such a barrier when the joint undergoes substantial lateral displacement, various mechanisms have additionally been provided in order to allow one or both sides of the barrier to shift along the walls of the joint. Some configurations provide for the barrier to be rigidly affixed to one side of the joint while the opposite edge of the barrier is slideably retained in a groove or track attached to the opposite wall of the joint. Alternatively, both edges of the barrier are retained within grooves or tracks formed in both sides of the joint in order to allow both sides to shift laterally relative the walls of the joint. These prior art fire barriers suffer from a number of shortcomings. First and foremost, as the joint walls shift laterally in the described systems, substantial shear loads are transferred to the barrier material due to the friction inherent in the groove or track attachment configurations. Any distortion, damage or obstruction of the retaining tracks further aggravates the potential for failure. Furthermore, such systems are relatively complex and their retrofitment to typical in-place joint configurations may be problematic and therefore very costly. SUMMARY OF THE INVENTION The present invention provides a fire barrier that prevents the spread of smoke, heat and flame through a dynamic void such as a seismic joint. The system's configuration ensures that an effective barrier is maintained despite substantial displacement or distortion of the joint. Moreover, the barrier is relatively inexpensive, easily installed, and is readily retrofitted to many existing joint cover systems. The barrier system of the present invention functions in conjunction with a diagonal bar mechanism, also known as an easy tong arrangement, that is commonly employed to maintain joint covers in position over a dynamic joint. Tracks incorporated in the opposite walls or top edges of the joint retain the ends of diagonally positioned bars that are distributed along the length of the joint. Wheels or rollers may be attached to the ends of the bars to reduce friction. As the joint narrows or widens, the angle of the bars adjust to compensate for the change in the joint's width. Relative lateral displacement causes the ends of the bars to simply slide or roll in their respective tracks. The fitment of hemispherical rollers or the incorporation of sufficient play in the mechanism by which the bars are retained in the tracks or grooves, allow the bars to angle upwardly and downwardly as the opposite sides of the joint undergo relative vertical displacement without in any way impeding the system's other degrees of freedom of movement. The actual fire barrier component of the present invention consists of a flexible sheet or blanket material which many include layers of insulation sandwiched between metal foil backing. The barrier extends along the entire length of the joint and is of a width substantially greater than the nominal width of the joint. In one embodiment, the two long edges of the material are suspended directly from the above-described bar mechanism so as to allow the excess material therebetween to hang down into the joint. This is achieved by the use of hanger clips or hanger rails that are pivotally attached to the diagonal bars and that hook into complementing hooked features incorporated in or affixed to the edges of the barrier material. The edges of the material are biased into sliding engagement with the joint walls, either by the hanger clips or rails themselves or by additionally fitted spring members. Alternatively, the fire barrier component may be suspended from a cover plate that is maintained in a centered position by the above-described bar mechanism. Hanger clips extending downwardly from the cover support the fire barrier material, as well as bias its edges into sliding engagement with the joint walls. Spring members may additionally be fitted to ensure proper contact. Friction reducing surfaces may be applied either to the joint walls or incorporated in the barrier material, or both, in order to ensure the system's smooth operation. The configuration of the present invention completely isolates the barrier material from shear forces during relative lateral movement of the walls of the joint while only very minor shear stresses are transferred to the material during a widening or narrowing of the joint as the diagonal support bars twist. The system is quickly and easily retrofitted to many joint cover-centering mechanisms already in place in many existing structures. These and other features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments which, taken in conjunction with the accompanying drawings, illustrate by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of the fire barrier system of the present invention; FIG. 2 is a top plan view of the system shown in FIG. 1; FIG. 3 is a perspective view of an alternative embodiment of the invention; FIGS. 4a, b and c are top plan views of further alternative embodiments of the present invention; and FIG. 5 is a cross-sectional view of another alternative embodiment of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT The figures generally illustrate the fire barrier system of the present invention. The barrier material is disposed within a seismic joint by suspension from a series of diagonal bars that span the joint. The edges of barrier are urged against the walls of the joint so as to effect a seal against heat, smoke and flames yet remain easily shiftable along the length of the walls. FIG. 1 is a cross-section of the preferred embodiment of the present invention. A structural void 12, such as a seismic joint, is defined by opposing walls 14 and 16. Suspended therebetween is shown fire barrier 18 which comprises a sandwiched structure of layers of insulation between metal backing material. A track or retention groove 20, 22 is securely incorporated in both sides of joint 12 and extends along substantially its entire length. A series of diagonally positioned support bars 28, having a length substantially greater than the nominal width of the joint, span the joint. Each bar is supported at its ends by wheels or hemispherical rollers rotatingly attached thereto and retained within the tracks. A widening of the joint causes each bar to assume a more perpendicular orientation as its ends shift within the retention tracks while a narrowing of the joint causes each bar to assume a more angled orientation. Such mechanism is sometimes referred to as a lazy-tong arrangement and is commonly employed to maintain a cover in a centered position above a dynamic joint. In the system shown in FIGS. 1 and 2, the fire barrier material 18 is suspended from the diagonal support bars 28 by a series of hanger clips 30, each pivotally attached to a support bar at 31. Each clip terminates in an up-turned hook 33 that engages a downturned hook member 32 securely affixed to the barrier material 18 to provide support therefore. An alternative clip configuration may be employed that is pivotally affixed to the center of each support bar and supports, and biases both edges of the barrier material. Each clip is formed from spring material and is configured so as to exert a force against the walls 14, 16 of the joint 12. The clips thereby serve, to simultaneously support the fire barrier as well as bias it into sealing engagement with the joint walls. FIG. 3 illustrates an alterative embodiment in which a number individual spring clips are replaced by a single hanger rail 34 which extends along a substantial portion of the joint and is pivotally attached to a number of the support bars at 36. The hanger rail terminates in an upturned edge 37 that engages the downturned hook members 32 incorporated in the barrier material 18. The rail exerts a biasing force directed outwardly toward the walls of the joint. Friction reducing surfaces 38, 40 may optionally be incorporated in the fire barrier/joint wall interface either by attachment to the wall, to the fire barrier material or to both. Additionally, intumescent material 42 may be disposed near the interface in order to ensure a proper seal upon being subjected to heat. Alternatively or in addition thereto, a foam strip 44 may be included in the interface to seal against cold smoke. FIGS. 4a, b and c show alternative embodiments wherein additional springs 46, 48, 50 are used that either supplement the biasing function of the hanger clips or hanger rail against the joint's walls or exclusively provide such biasing force. Various configurations are shown which attach to the individual diagonal bars 28 at their centers and extend outwardly to engage the barrier material and urge it into contact with the joint walls. FIG. 5 illustrates another embodiment of the present invention wherein barrier material 18 is suspended from cover plate 52 which in turn is maintained in a centered position over joint 12 by a diagonal bar mechanism 54. The cover plate is pivotally attached to the center of each support bar 56, while the barrier material is supported by hanger clips 58 that are attached to the cover plate. The hanger clips 58 both support the barrier material, as well as bias its edges against the joint walls 14 and 16. Alternatively, a separate hanger clip may be employed to support each edge of the material. Additionally, spring members may be fitted to complement the biasing function of the hanger clips, or may be solely relied upon to ensure proper contact between the barrier edges and the side walls. In operation, the system of the present invention provides the function of preventing the spread of fire through the void to which it is fitted. Hangar clips 58 suspend the barrier 18 across the void 12 and urge its edges into firm contact with the walls 14, 16 of the void, thereby precluding the passage of smoke, heat and flame therethrough. The optionally incorporated intumescent material 42 melts upon exposure to heat to positively seal the interface. An optionally fitted foam strip 44 prevents the passage of cold smoke therethrough. Relative movement of the walls of the joint does not in any way compromise the system's ability to fulfill its fire barrier function. Relative movement of the joint walls 14, 16 in a direction normal to the length of the joint 12, i.e. a widening or narrowing thereof, causes the diagonal bars 28 to twist while the ends 24, 26 of the bars shift slightly in opposite directions within their respective retention grooves 20, 22. This causes only a very slight amount of shear stress to be transferred to the barrier material which it is easily capable of accommodating. The edges of the material continue to be urged into firm contact with the walls at all times. A relative vertical displacement of the sides of the joint causes the bars 28 to be angled out of the horizontal without in anyway diminishing the contact of the barrier material 18 with the walls 14, 16. Play inherent in the bar end retention system or the use hemispherical rollers 24, 26 allow the diagonal support bars to easily compensate for such movement without compromising their ability to move in the other directions. In the event the joint 12 is subjected to relative lateral movement, the ends of the diagonal bars 24, 26 simply roll or shift in their respective retention grooves 20, 22. The angle of the bars does not change and consequently, absolutely no shear loads are transferred to the barrier material 18 itself. Friction-reducing material 38, 40 incorporated in the joint wall/fire barrier interface ensures that the barrier does not snag during wall displacement thereby ensuring the system's smooth operation. Regardless of the final configuration resulting from the relative displacements or contortions of the joint walls, the barrier 18 will remain in tact and will continue to be held in sealing engagement with the joint's walls. The system therefore continues to prevent the spread of smoke, heat and fire through the joint. While a particular form of the invention has been illustrated and described, it will also be apparent to those skilled in the art that various modification 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. What is claimed is: 1. A fire barrier system for sealing a dynamic void, comprising:diagonally oriented support bars spanning the width of said void, each bar's ends being slideably affixed to opposite walls defining said void; flexible fire barrier material extending across and having opposite edges extending along said void, said material being of a width substantially wider than the nominal width of said void; means suspending from said diagonal support bars the edges of said barrier material oriented along the length of said void; and means biasing said opposite edges of said material into sealing engagement with said opposite walls. 2. The fire barrier system of claim 1 wherein said suspension means comprise individual hanger clips, pivotally affixed to said diagonal support bars and configured so as to engage said barrier material therebelow is an interhooking manner. 3. The fire barrier system of claim 2 wherein said hanger clips comprise said biasing means. 4. The fire barrier system of claim 2 wherein said biasing means comprises springs attached to said diagonal bars and wherein said springs extend across the void to engage said opposite edges of said barrier material. 5. The fire barrier of claim 1 wherein said suspension means comprise hanger rails extending along the length of said void, pivotally affixed to said support bars and configured so as to engage said barrier material therebelow in an interhooking manner. 6. The fire barrier system of claim 6 wherein said hanger rails comprise said biasing means. 7. The fire barrier of claim 6 wherein said biasing means comprises springs wherein said springs extend across the void to engage said opposite edges of said barrier material. 8. The fire barrier system of claim 1 wherein friction reducing surfaces are disposed in the interface between the barrier material and the walls of the void. 9. The fire barrier system of claim 1 wherein intumescent material is disposed in the interface between the barrier material and the walls of the void. 10. The fire barrier system of claim 1 wherein foam strips are disposed in the interface between the barrier material and the walls of the void in order to seal out cold smoke. 11. A fire barrier system sealing a dynamic void, comprising:diagonally oriented support bars spanning the width of said void, each bar's ends being slideably affixed to opposite walls defining said void; a cover plate disposed over said void, pivotally attached to the center of each of said support bars; flexible fire barrier material extending across and having opposite edges extending along said void, said material being of a width substantially wider than the nominal width of said void; means suspending from said cover plate the edges of said barrier material oriented along the length of said void; and means biasing said opposite edges of said material into sealing engagement with said opposite walls. 12. The fire barrier system of claim 11 wherein said suspension means comprise individual hanger clips affixed to said diagonal support bars and configured so as to engage said barrier material therebelow in an interhooking manner. 13. The fire barrier system of claim 12 wherein said hanger clips comprise said biasing means. 14. The fire barrier system of claim 11 wherein friction reducing surfaces are disposed in the interface between the barrier material and the walls of the void. 15. The fire barrier system of claim 11 wherein intumescent material is disposed in the interface between the barrier material and the walls of the void. 16. The fire barrier system of claim 11 wherein foam strips are disposed in the interface between the barrier material and the walls of the void in order to seal out cold smoke.

1994-08-25

en

1995-10-31

US-47550183-A

Low calorie dessert mixes and products prepared therefrom ABSTRACT New dessert mixes are obtained by preparing aqueous solutions or dehydrated powders containing butterfat; nonfat dry milk solids containing a certain portion of whey protein concentrate; a fructose-based sweetening agent and a stabilizer. The new mixes are prepared by combining a dry premix of whey protein concentrate and/or other nonfat milk solids, fructose and stabilizers with milk and/or cream; heating the mixture to effect pasteurization and then homogenizing the mixture to form the desired solution which may optionally be dehydrated. The dehydrated powdered mix may be redehydrated and then frozen. This is a continuation-in-part of Ser. No. 357,839, filed Mar. 15, 1982, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to new and improved dessert premixes and mixes. More specifically, the invention relates to new dessert premixes and mixes preferably containing only natural products which are capable of being converted to frozen products having very attractive properties. More particularly, the invention provides new dessert premixes and mixes based on natural products preferably containing no added sucrose or glucose and having attractive consumer properties, such as reduced calorie content and improved sweetness and taste. The new dessert mixes comprise dehydrated powders or aqueous solutions having a solids content made up of butterfat; nonfat dry milk solids, a portion of which are preferably whey protein concentrate; a sweetening agent consisting of at least 75% by weight fructose; and one or more stabilizers which preferably contain at least a stated amount of microcrystalline cellulose. A premix powder consisting of whey protein concentrate, fructose, stabilizers and other additives such as egg solids, flavoring agents and other milk solids is first prepared. The new mixes are prepared by combining the premix with appropriate amounts of milk and/or cream, heating the mixture to effect pasteurization and then homogenizing the mixture to form the desired dispersion. The new invention also provides valuable products, such as soft dessert ice cream mixes, hard ice cream, etc., prepared by subjecting the aforementioned solutions to a freezing process. In addition, the homogenized solutions may be dehydrated to form a powdered mix which can be rehydrated and then frozen. 2. Prior Art A great variety of different types of dessert mixes which can be frozen to produce soft and hard ice cream products has been prepared in the past. Most of these products have been based on the use of sucrose and have a high caloric content. In the interest of weight reduction, attempts have been made to produce products by substituting materials for the sucrose, but the attempts, heretofore, have not been entirely satisfactory. In many cases, these products have been deficient in taste or body and texture, and either it has been difficult to freeze them, or retain their composition at the freezing temperatures, or too expensive to produce them for large scale consumption. Arbuckle, Ice Cream, 3rd Edition, AVI Publishing Co., Inc., 1977, pp. 80-91, discloses various sources of sweetener solids for use in making ice cream. Various mono- and di-saccharides in numerous stages of refinement are listed. Arbuckle recites that authorities consider an acceptable zone of sweetness for ice cream to be between about 13 and 20% by weight concentration based on sucrose. Considering sucrose to have a sweetening value of 100, fructose has a relative sweetness of 173, and invert sugar (a mixture of glucose anf fructose obtained by the hydrolysis of sucrose) has a relative sweetness of 127. Glucose has a sweetening value of 74. Because glucose and invert sugar (mixture of glucose and fructose) are monosaccharides or monosaccharide mixtures having a relative low molecular weight of 180.1, they tend to depress the freezing point of ice cream more than higher molecular weight sugars such as sucrose, lactose, maltose and converted corn syrup solids. Arbuckle states that this effect on freezing point limits the amount of monosaccharide in ice cream to about 25% of the total desired sugar. In other words, at least 75% of the sweetening agent must be a di- or oligosaccharide. Moreover, the relative sweetness of monosaccharides does not necessarily transfer proportionately when substituted for sucrose. Arbuckle states that it requires 1.05 pounds of invert sugar to equal one pound of sucrose even though invert sugar is purportedly 1.27 times as sweet as sucrose. However, invert sugar contains 25% to 30% water. Arbuckle also states that it takes 1.25 pounds of glucose to replace one pound of sucrose. Therefore, due to the lowering of the freezing point and the lack of direct translation of sweetening powers, it is not recommended to prepare an ice cream having a monosaccharide as the only added sugar. Arbuckle states that invert sugar should not replace more than 33% of the sucrose when making ice cream and that dextrose, i.e., glucose, should not replace more than 35% of the sucrose. By the same reasoning, Arbuckle states that honey, which is a mixture of 17.5% moisture, 74.5% invert sugar (glucose and fructose), 2% sucrose, 2% dextrin and 3.8% miscellaneous matter requires 1.4 pounds to equal one pound of sucrose and should not replace more than 30% of sucrose in ice cream. Arbuckle makes several sugar (sucrose)-saving suggestions to stretch a manufacturer's allotment of cane or beet sugar (sucrose), such as replacing sucrose with corn sugar or corn syrup solids; replacing part of the sugar with milk solids and inverting up to 1/3 of the sucrose. None of the suggestions teaches or even indicates that sucrose can be entirely replaced or even replaced by a majority of a monosaccharide such as fructose. In fact, Arbuckle states on page 38 that an appropriate ice cream sweetener can be obtained only by using some sucrose in the blend. The percentage of sweetening agent which can be blended with sucrose depends upon various factors such as desired sugar concentration, total solids content, effect on physical properties such as freezing point, viscosity and whipping ability and the inherent relative sweetening power of the sweetening agent. All illustrations and tables in Arbuckle indicate that at least two-thirds of the sweetening agent must be sucrose. Koerver, in U.S. Pat. No. 2,500,315, teaches an ice cream with an increased lactose (milk sugar which is a disaccharide) content, and Decker, in U.S. Pat. No. 3,510,316 teaches a nonfat dairy dessert where part of the sugar (sucrose) is replaced by a less sweet corn syrup (28 DE). According to Arbuckle, about 80% of a low-conversion corn syrup is made up of polysaccharides consisting of three or more monosaccharides linked together. However, none of the prior art surveyed suggests that sucrose can be replaced entirely, or even substantially, as a sweetener for ice cream by another sugar or blend of sugars. Arbuckle states that about 25% of the MSNF (milk solids not fat) content of ice cream may be supplied by dried whey which is listed as being 13.4% protein (lactalbumin), 76.1% lactose and 10.5% mineral salts. In the same paragraph, MSNF is listed as 35.8% protein (27.1% casein and 8.7% lactalbumin), 54.4% lactose and 9.8% mineral salts. Arbuckle further states that a high quality, good flavored dry buttermilk can be used to replace all of the MSNF of a mix without affecting texture or taste. The use of sodium caseinate and low lactose skim milk is also mentioned. Sodium caseinate is said to produce a slight undesirable flavor in finished ice cream products. However, there is no mention that a product rich in whey proteins, such as a whey protein concentrate or isolated whey proteins, can be utilized at all. OBJECTS OF THE INVENTION It is an object of the invention, therefore, to provide an improved type of dessert premix and mix. It is a further object to provide an improved type of dessert mix which is prepared from natural products and can be converted by freezing to form a variety of ice cream type products. It is a further object to provide new dessert premixes which are preferably free of sucrose which can be converted to frozen products having desirable sweetness and taste by the addition of milk and/or cream. It is a further object to provide new dessert mixes which preferably contain no added sucrose or glucose and which can be converted to sweet-tasting dessert products which have a reduced sugar content. It is a further object to provide new dessert mixes containing fructose which can be converted to frozen products having attractive physical and nutritional properties. It is a further object to provide new and improved soft dessert ice cream products and hard ice cream products. These and other objects of the invention will be apparent from the following detailed description thereof. SUMMARY OF THE INVENTION The new dessert mixes of the present invention comprise aqueous solutions or suspensions having a solids content made up of butterfat, nonfat dry milk solids (a portion of which is preferably whey protein concentrate), a special proportion of substantially pure fructose and a stabilizer preferably containing microcrystalline cellulose. While less preferred, up to about 25% of the fructose can be replaced by other sweetening agents such as corn syrup solids, maltose, glucose, sucrose, honey, invert sugar, saccharin and aspartame. It is also possible to produce an acceptable mix without the use of a whey protein concentrate forming part of the nonfat dry milk solids. However, because of the improved characteristics attributed to the use of whey protein concentrate, its inclusion as part of the nonfat milk solids is clearly preferred. As used herein, the term whey protein concentrate shall be deemed to include an equivalent amount of isolated whey protein. A premix is first prepared which is a powder consisting of whey protein concentrate or other nonfat milk solids, fructose-based sweetener, a stabilizer-emulsifier mix, and other ingredients such as egg solids, flavorings, and additional milk solids such as nonfat dry milk, dry buttermilk, caseinate salts or low lactose skim milk. For purposes of brevity, the stabilizer-emulsifier mix may be referred to as "stabilizer" only. The new mixes are preferably prepared by combining the premix components together with milk and/or cream along with other added milk solids and flavorings if desired; and heated the mixture to effect pasteurization; and then homogenizing the mixture to form the desired liquid mixture. In a home environment, it may not be possible to pasteurize and homogenize the liquid mixture prior to freezing. If desired, the liquid mixture may be dehydrated to powdered form by means of freeze-drying or any other water removal process which will not substantially affect the characteristics of the mix such as color, flavor and nutritional qualities. The powdered mix can then be diluted with water just prior to use. Valuable products, such as soft ice cream mixes, hard ice cream, etc., are obtained by subjecting these liquid mixtures to a freezing process. It has been found that the new dessert mixes of the present invention posses many valuable and attractive properties. It has been found, for example, that the products prepared therefrom, such as the soft ice cream mixes and the hard ice cream, have reduced sugar content and are particularly attractive for dietary purposes. In addition, the products have improved sweetness and taste despite the elimination of all or substantially all of the conventional sucrose sugar. Further advantage is found in the fact that, particularly in the case of the soft dessert mixes, there can be an increase in overrun during freezing which results in an even lower calorie content and lower cost of operation. Contrary to the allegations of the prior art, it has been found that surprisingly, the fructose-sweetened dessert mixtures can be frozen at, or near, the usual ice cream freezing temperatures without any undue depression in the freezing point. DETAILED DESCRIPTION OF THE INVENTION The new dessert mixes of the present invention are preferably prepared by mixing butterfat, nonfat dry milk solids, a portion of which are preferably whey protein concentrate or isolated whey protein, a special proportion of fructose-based sweetener and a stabilizer with the desired milk and/or cream; heating the mixture to effect pasteurization; and then homogenizing the mixture. Additional ingredients such as flavoring, color, fruit, nuts, honey, eggs, etc. may be added to the mixture after the pasteurization or homogenization to produce the product desired. Preferably, the dry ingredients consisting of the whey protein concentrate or other milk solids, fructose-based sweetener and stabilizer mix will be precombined into a premix. Other ingredients such as egg solids, flavorings, and additional milk solids such as skim milk, buttermilk powder, caseinate salts, or low lactose skim milk may also be added to the premix. It will then be necessary to add the premix only to the desired amount of skim milk, milk, and/or cream (and additional butterfat if necessary), before freezing. The dessert mixes of the present invention may be used to prepare two primary types of frozen desserts, i.e., ice cream including frozen custard or french vanilla, and ice milk. The principle difference between ice cream and ice milk resides in the fat and total solids content of the liquid mixes. Ice cream generally has about 8-20% fat content and from about 35-49% total solids. On the other hand, ice milk has a fat content between about 2% and 7% and a solids content of about 24-34%. Either the ice cream mix or ice milk mix may be used to prepare hard or soft serve products. However, the ice milk mix is preferably used for soft serve. The upper limit for fat content is determined by preferences of taste and physical properties of the ice cream. There are specialty ice creams which contain fat contents of 25% or higher. Frozen dessert mixes having fat contents in the range of 2-25% are within the scope of this invention. The mixes may be made available in three different forms which may ultimately be used to prepare the same frozen dessert. The first form is a liquid mixture or aqueous suspension of all ingredients. This liquid mixture has been pasteurized and homogenized in the manner described herein and is ready to be frozen. The second form consists of a dry mixture obtained by dehydrating the liquid mixture to a powder by freeze-drying or equivalent means. This powder contains all essential ingredients and needs only to be remixed with water before freezing. The third form consists of the premix of dry ingredients including fructose, whey protein concentrate isolated whey protein or other milk solids, stabilizers, other milk solids if necessary, and any other ingredients such that the premix need only be mixed with cream and milk and/or skim milk before freezing. The invention will first be described in terms of the liquid mixture comprising form one and the dried powder comprising form two since they are each complete formulations of a dessert mix. The premix suitable for combination with various combinations of milk and cream will then be described in detail. The liquid aqueous mixture or suspension will generally comprise the following ingredients or solids contents in percentages by weight. ______________________________________ Overall Range Range Ingredient Range (Preferred) (Preferred) ______________________________________ Butterfat 2-25 2-7 (3-6) 8-25 (12-18) MFNS 8-15 8-15 (11-13) 10-14 (10-13) Fructose-Based 7-18 7-13 9-8 Sweetener* Pure Fructose 7-14 7-11 (8-10) 9-14 (10-13) Crystalline** Stabilizers .5-2.5 .5-2.5 (.7-2.0) .5-2.5 (.7-2.0) Egg Yolk 0-1.5 1.0- (.25-1.0) 0-1.5 (.5-1.5) Solids Milk Solids 10-35 10-22 18-35 TOTAL SOLIDS 24-49 24-34 35-49 ______________________________________ *Range for fructose combined with other sugars such as glucose, sucrose, maltose and corn syrup solids. **Range for fructose when used alone. Similarly, a dehydrated or dried mixture (discounting any moisture present) will generally have the following weight percentage range: ______________________________________ Soft Serve Overall or Ice Ice Cream Ingredients Range Milk Range Range ______________________________________ Butterfat 6-57 6-29 16-57 MNSF 20-63 24-63 20-40 Fructose-Based 20-53 20-53 20-50 Sweetener Stabilizers 1-10 1.4-10 1.0-7.0 Egg Yolk 0-4.5 0-4 0-4.5 Solids Milk Solids 39-76 39-75 48-76 TOTAL SOLIDS 100 100 100 ______________________________________ The butterfat employed in the new mixes may be any suitable butterfat, but is preferably butterfat from fresh cow's milk or cream. The preferred butterfat preferably contains as major triglycerides C4 to C10 saturated fatty acids, C14 saturated fatty acids, C16 saturated fatty acids, C18 saturated fatty acids and C18 unsaturated fatty acids. The proportion of each will vary depending on the season, temperature, etc. Generally, the preferred fats contain 8 to 12% C4 to C10 saturated acids, 8 to 12% C14 saturated acids, 30 to 40% C16 saturated acids, 8 to 12% C18 saturated acids, and 25 to 35% unsaturated acids. As previously mentioned, the amount of the butterfat added to the dessert mix may vary over a wide range depending upon the type of product desired, i.e., ice cream or ice milk mix. In general, the amount of the butterfat in the solutions prepared from the milk and cream will vary from about 2 to 25%, and preferably from 2 to 20%. In making the ice milk and soft dessert mixes, it is permissible to employ solutions containing about 2 to 7%, and preferably 3 to 6%, by weight of the butterfat, and in making the hard ice cream dessert product, it is permissible to employ liquid mixtures containing 8% to about 25%, and preferably 12 to 18%, by weight of butterfat. The second component in the dessert mixes of the present invention comprises a blend of nonfat dry milk solids. Preferably, at least a portion of the nonfat dry milk solids is a whey protein concentrate or isolated whey protein. The main ingredients of nonfat dry milk solids include lactose (milk sugar), protein, and minerals, such as calcium. Minute amounts of fat may also be present. Other components include Vitamin A, pantothenic acid, riboflavin, thiamine, niacin and other minerals, such as phosphorus, potassium, sodium and iron. Particularly preferred nonfat dry milk solids to be used are whey protein concentrates, skim milk powders and dry buttermilk powders and mixtures thereof. These sources of nonfat milk solids contain about 45 to 55% lactose, 30 to 38% protein, 0.5 to 5.0% fat, and 6 to 10% minerals. However, the protein content of the whey protein concentrate may vary between about 25 to 75 percent. A method for preparing the nonfat dry milk solids can be found in Hall, et al., Drying of Milk and Milk Product, AVI Publishing Co., 1971. The major portion of nonfat milk solids may preferably be supplied by liquid skim milk, milk and/or cream. Whey protein concentrate is defined by the United States Food and Drug Administration as the substance obtained by the removal of sufficient non-protein constituents from whey so that the finished dry product contains not less than 25% protein. This product may not contain more than 60% lactose and has a mineral content between 2 and 15%. Whey protein concentrates are commercially available having protein content ranging from about 25 to 75%. A particularly preferred whey protein concentrate for use in the present invention has a protein, lactose and mineral content which is approximately the same as nonfat dry milk solids and is sold under the tradename "Protec". Protec powder contains about 35% protein, 54% lactose, 1% fat and 10% minerals and moisture. Whey protein concentrates containing higher protein concentrations may also be advantageous. Higher whey protein content adds to the body of a frozen product by strengthening the lamella surrounding the air sac in the frozen product. In addition, higher whey protein means less lactose in the concentrate. Reduced lactose is preferable since lactose crystallizes out increasing the sandy texture of the frozen product. In this context, the entire milk solids not fat content of the milk could be whey protein concentrate. However, federal and state regulations currently limit the amount of whey solids of any kind which can be used in frozen dessert mixes. Isolated whey protein may be used in the place of whey protein concentrate in equivalent protein amounts. Thus, one pound of 50% whey protein concentrate may be substituted by one-half pound of isolated whey protein. The term "whey protein concentrate" as used herein is, therefore, deemed to include an equivalent amount of isolated whey proteins. Another difference betwen whey protein concentrate and nonfat dry milk is in the quality of the protein. As noted by the earlier citation to Arbuckle, supra, the 35.8% protein in nonfat dry milk is about 27.1% casein and 8.7% lactalbumin. Whereas, in whey, essentially all of the protein is lactalbumin (including lactaglobulin). According to the National Dairy Council, whey proteins are higher in nutritive value than casein. Casein has a protein efficiency ratio (PER) of 2.5 whereas the PER for whey protein is about 3.6. It has been found that between about 10 and 100% of the nonfat dry milk solids may be whey protein concentrate in order to obtain the desired results. However, in order to satisfy federal and state regulations, they whey protein concentrate must presently be limited to not more than 25 to 35% of the milk solids not fat. A preferable range is between about 10 and 35% of the milk solids. Thus, the addition of whey protein concentrate favorably affects both the nutritional and physical qualities of the frozen desserts of the invention. In addition to nonfat dry milk and whey protein concentrate, it may be desirable to utilize dry buttermilk powder as a source of nonfat dry milk solids. Dry buttermilk contains more fat than nonfat dry milk or whey protein concentrate, but has protein and lactose concentrations which are about the same as nonfat dry milk. The approximate composition of dry buttermilk, according to Arbuckle, is 3.9% moisture, 4.7% fat, 35.9% protein, 47.8% lactose and 7.7% ash. When using dry buttermilk, it will be necessary to take the fat content into consideration. Dry buttermilk can be used in the place of some or all of the nonfat dry milk. Nonfat dry milk, dry buttermilk and other sources of MSNF, such as whey powder and sodium or calcium caseinate and low lactose skim milk, may be utilized as a source of nonfat milk solids. The texture and body of frozen desserts prepared from these sources without the presence of whey protein concentrate is clearly inferior to the desserts prepared with the whey protein concentrate preset, although the flavor is acceptable. Therefore, the presence of whey protein concentrate is not absolutely essential to prepare fructose-sweetened frozen dessert within the broadest aspects of the present invention. However, within the confines of its preferred embodiment, whey protein concentrate or its equivalent in isolated whey protein is a highly preferable, if not essential, ingredient. While not known for a certainty, it is believed that the whey proteins are superior in whipping ability to other nonfat milk solids. Whipping ability is based, in part, on the cohesion and strength of the lamellae. Higher whey protein concentrations in the source of nonfat milk solids are thought to produce superior products since they increase the whipping ability and reduce the lactose content and its attendant propensity toward creating a sandy texture in the frozen product. Somewhat similar, but less acceptable, results are obtained through the use of low lactose skim milk which contains the same ratio of casein to whey proteins as skim milk. The higher the protein content of the whey protein concentrate is, the lower the total whey protein concentrate content can be overall. The amount of the nonfat dry milk solids to be employed may vary over a considerable range depending upon the type of product desired. In general, the amount of the nonfat dry milk solids to be employed in the dry mix comprises about 20% to about 40% by weight, and in the aqueous solutions, about 8% to about 15% by weight. In the soft dessert mixes, the preferred amount of blended nonfat dry milk solids range from about 8% to about 15% by weight in the aqueous solution, and in the hard ice cream from about 10% to about 14% by weight in the aqueous solution. The third essential ingredient in the dessert mixes of the present invention comprises the substantially pure crystalline fructose. High fructose corn syrup and other components containing large amounts of fructose are less preferable for use in the present invention. While less preferable, it is possible to prepare acceptable dessert mixes wherein the sweetening agent is not pure fructose. These sweetening agents must be at least seventy-five percent by weight fructose. When combining fructose with other sweetening agents, great care should be taken not to use more of these alternate sweetening agents than is absolutely necessary. It may be preferable to use small amounts of non-carbohydrate sweetening agents having a high relative sweetness such as aspartame or saccharin to complement the fructose in lowering the caloric content. Less preferable are the conventional carbohydrate sweetening agents such as the various corn syrups, glucose, sucrose, maltose, invert sugar, honey and mixtures thereof. When using a combination of fructose with other sweetening agents, the total fructose-based sweetening agent content may very from about 20% to 53% in the dry mix, and about 7% to about 18% in the aqueous solution. In soft dessert mixes, the amount can vary from about 7% to about 13% by weight in the aqueous solution; and in hard ice cream products, the range will vary from about 9% to 18%. It is especially preferred that the sweetening agent employed is pure crystalline fructose free of other sugars, such as glucose, sucrose, etc. The crystalline fructose should be employed in the new mixes in amounts varying within certain limits. The amount of fructose may vary from about 20% to about 40% in the dry mix, and about 7% to about 14% in the aqueous solution. In making the soft dessert mixes, the preferred amount of fructose to be used ranges from about 7% to about 11% by weight in the aqueous solution, and in the hard ice cream products, the preferred amount of fructose will range from about 9% to about 14% in the aqueous solution. Stabilizers, emulsifiers, fillers and other additives are also included in the dessert mixes of the present invention. Microcrystalline cellulose is preferably included as one ingredient of the stabilizer-emulsifier combination. The stabilizer used may also contain any other suitable stabilizing agents, such as cellulose gum (carboxymethyl cellulose), gum tragacanth, India gum, karaya gum, locust bean gum, guar gum, Irish moss, agar-agar, gelatin, pectin, carageenan, sodium alginate and psyllium seed extract. Mono- and diglycerides are preferably added as emulsifiers. Polyoxyethylene derivatives of hexahydric alcohols, glycol and glycol asters may also be used as emulsifiers. Preferred stabilizers and emulsifiers to be used comprise a mixture containing from 20 to 50% by weight of microcrystalline cellulose. Preferably, the microcrystalline cellulose will be combined with cellulose gum (CMC), carageenen and mono- and diglycerides. More particularly, it has been found that an especially preferred stabilizer comprises 20 to 50% microcrystalline cellulose, 20 to 40% mono- and diglycerides, 10 to 25% CMC (sodium carboxymethyl cellulose) CMC and 1 to 10% carageenen. The amount of the stabilizer and emulsifier to be employed may vary over a considerable range. In some jurisdictions, the maximum amount of stabilizer is 0.5% and the maximum allowable amount of emulsifier is 0.2%, making a maximum total of 0.7%. In general, the amount of stabilizer and emulsifier will vary from about 0.5% to about 2.5%, and more preferably in an amount varying from about 0.7% to 2.0% by weight. Since, in its preferred embodiment, the fructose content of the mixes of this invention is much less than the sucrose content in conventional frozen dessert mixes (7-14% for fructose as compared to 12-20% for sucrose), the total solids content will also generally be less for comparable products. The solids can be bolstered somewhat by increasing the milk solids not fat and butterfat contents. However, in order to maintain the reduced caloric content obtained by the relatively low fructose content, it is not desired to substantially increase the total solids. It is, therefore, essential to utilize a stabilizer which will efficiently function to maintain the desired body and texture of the frozen mix by combining with the generally higher water content. In this regard, it has been found desirable, if not essential, to incorporate the above-mentioned finely divided microcrystalline cellulose into the stabilizer. Egg yolk solids are also a desired part of the dessert mixes to improve texture, whipping ability and firmness. Because egg solids tend to oxidize more easily than other ingredients, and acquire an off-flavor, it is desired to add fresh eggs to the mix along with the milk and cream just prior to freezing. It is preferred to have about 0.25 to 1.5% of the total solids of the mix as egg yolk solids. This translates, essentially, into about 1 to 6% by weight fresh eggs or 0.33 to 2% as dried whole egg solids. Dried egg yolk solids or dry whole egg solids may be added to the premix if desired. However, the premix should be utilized as soon as possible if dried egg solids are incorporated. As used herein, terms such as aqueous solution or liquid mixture are used in a generic sense to include dispersions, colloidal suspensions and true solutions. The physical nature of such solutions or mixtures may vary according to the ingredients, processing techniques, etc. The product can be prepared in a variety of methods. For example, a dry premix can be prepared by first combining the whey protein concentrate and/or other nonfat milk solids, fructose-based sweetener stabilizer-emulsifier mix (and egg solids if desired), and subsequently adding an appropriate amount of liquid milk and/or cream (and fresh eggs) to furnish the required nonfat milk solids, butterfat and aqueous medium; or all of the ingredients can be combined at the same time, i.e., by combining the nonfat milk solids, whey protein concentrate, fructose-based sweetener, stabilizer and butterfat (as a separate component or as a component in the milk or cream) with the desired amount of milk and/or cream and fresh eggs. Whatever way the products are prepared, the resulting aqueous solution should preferably have a solids content varying from about 24% to about 49% by weight. Dry mixes can also be prepared by making the aqueous solution and then spray-drying the mixture to remove the water. As a result, the butterfat will be included in the dry mix and the desired product can be obtained by merely adding water. Other ingredients may be added to the dessert mix as dry solids or to the aqueous solutions or mixtures prepared therefrom. For example, it may be desirable to add components such as honey, nuts and flavoring material such as cocoa, carob, vanilla, fruits and fruit flavors, etc. Calcium lactate or sulfate may be added as calcium builders. Vitamin A and D, which are generally added to fortify milk, may be added. The amount of the added component and the time for adding the material may vary over a considerable range depending upon the nature of the finished product desired. As noted, the new dessert mixes may be prepared by a variety of different methods. If a dry solid premix is prepared first, it may be prepared by merely mixing the dry components together in any desired order and then combining the mixture with the aqueous and fat components such as skim milk, milk, cream, etc. After the aqueous dispersion has been prepared, the mixture is then heated to effect pasteurization. The temperature employed and the time of heating will vary over a wide range, depending upon the product desired. In general, pasteurization temperatures range from about 145° F. to about 204° F. The procedure generally varies from a low of 30 minutes at 145° to a high of 204° for about 0.05 second as specified in 37 C.F.R. 131.3(b) which pertains to dairy products in general. According to 37 C.F.R. 135.3, frozen dessert mixes are to be pasteurized at a low of 155° F. for 30 minutes to a high of 175° for 25 seconds. Following pasteurization, the mixture is homogenized. This involves passing the liquid mix through exceeding narrow slits or openings commonly known as homogenizing valves. The pressure at which the liquid is pumped is regulated by the closure of the homogenizing valve. In some case, it may be necesssary to employ a second stage. In general, pressures generally range from about 1,000 to 5,000 psig where, in a two-stage process, the first stage employs a pressure of 2,000 to 5,000 psig and the second stage a pressure of 1,000 psig. The homogenized product, as prepared above, is then utilized to produce a variety of different types of valuable dessert products. For example, the products may be frozen at a suitable temperature to prepare ice milk, soft ice milk, soft ice cream, and hard ice cream products. When freezing, the materials may be frozen according to conventional procedure wherein the aqueous dispersion is added to the mixing equipment involving stirring and the reduction of temperature. Suitable temperatures range from about 19° F. to a about 22° F. In making the hard ice cream product, the freezing should preferably be sufficient to produce a 0° core by the end of 24 hours of hardening. As noted above, one advantage of the new products of the invention, particularly in the case of the soft dessert product, is that in freezing, an overrun of 35% to about 100% is obtained. This results in a reduction in the calorie content as well as cost of production. Also, the liquid mixture may be frozen at or near the usual freezing temperatures even when crystalline fructose is used as the only added sugar. In addition, the products of this invention are preferably free from added glucose and sucrose (lactose is a disaccharide containing glucose and galactose). Sucrose and glucose are known to trigger insulin production and are absorbed relatively rapidly into the blood stream. Fructose, on the other hand, is absorbed more slowly into the blood stream and does not require the presence of insulin for absorption across the cell membrane. Therefore, there may be significant health advantages in a dessert product sweetened with fructose and not containing any sucrose other than just the possibility of lower calorie content. For example, the total sugar contents (lactose plus fructose) are much lower than comparable sucrose-sweetened products. To illustrate the preparation of the new products of the present invention, the following examples are given. It is to be understood, however, that the examples are given in the way of illustration and are not to be regarded as limiting the invention in any way. EXAMPLE I This example illustrates the preparaton of a white, hard ice cream mixture according to the present invention. 5266 pounds of cream containing 40.5% butterfat; 825 pounds of milk containing 1.3% butterfat; 3580 pounds of skim milk; 350 pounds of Protec powder (whey protein concentrate) made up of 35% protein and 54% lactose; and 1665 pounds of skim condensed milk, containing 33.78% total solids, were combined with 1375 pounds of pure crystalline fructose, 114 pounds of a stabilizer made up of 40% microcrystalline cellulose, 20% cellulose gum (CMC), 8% carageenen, 32% mono- and digycerides and 269 pounds of egg solids. This mixture was stirred together at a temperature of 40° F. for 2 minutes. The resulting product has a solids content of: ______________________________________ AS A AS A LIQUID MIX DEHYDRATED MIX ______________________________________ butterfat 16% 39.4% nonfat milk solids* 11.5% 28.3% fructose 10.25% 25.2% stabilizer .85% 2.1% eggs 2.0% 5.0% Total Solids 40.6% 100% ______________________________________ *21.5% whey protein concentrate The above product was then pasteurized by heating at 175° F. for 25 seconds. Following pasteurization, the product was homogenized by use of a single stage homogenizer at 2200 psi. Hard ice cream products at 80% overrun were prepared from the above-noted homogenized mix by freezing at 21° F. for a period of 2 minutes. The resulting product had a calorie content of about 220 calories per 100 grams, excellent sweetness and taste and very good body. The product retained its hard structure on storage over a period in excess of 180 days. The above product may be produced in different flavors by the addition of flavorings such as chocolate, strawberry, pineapple, chocolate chip, and the like prior to freezing. EXAMPLE II This example illustrates the preparation of a chocolate hard ice cream mixed according to the process of the invention. 2681 pounds of cream having a butterfat content of 40.5% was mixed with 2709 pounds of skim milk; 225 pounds of Protec powder (whey protein concentrate) made up of 35% protein and 54% lactose; and 805 pounds of skim condensed milk. To this was added 935 pounds of pure fructose; 66 pounds of stabilizer as in Example I; 156 pounds of fresh eggs; and 214 pounds of chocolate flavor. The mixture was stirred together at a temperature of 40° for 2 minutes. The resulting product had a solids content of: ______________________________________ AS A AS A LIQUID MIX DEHYDRATED MIX ______________________________________ butterfat 14% 32.9% nonfat milk solids* 11% 25.8% fructose 12% 28.2% stabilizer .85% 2.0% eggs 2% 4.7% chocolate flavor 2.75% 6.4% Total solids 42.6% 100% ______________________________________ *25% whey protein concentrate The above product was then pasteurized by heating at 175° F. for 25 seconds. Following pasteurization, the product was homogenized by use of a single stage homogenizer at 2200 psi. Hard ice cream products were prepared from the above-noted homogenized mix by freezing at 21° F. for a period of 2 minutes. The resulting product had a calorie content of 234 calories per 100 grams, excellent taste and sweetness and very good texture and body. The product retained its hard structure on storage for a period of time in excess of 180 days. EXAMPLE III This example illustrates the preparation of a white soft dessert mix according to the process of the invention. 2.0 pounds of cream containing 40.5% butterfat; 81.5 pounds of milk containing 4.0% butterfat; 1.25 pounds of powdered skim milk; 2.75 pounds of whey protein concentrate powder made up of 35% protein and 54% lactose; 10.5 pounds of pure fructose; 0.7 pounds of stabilizer as defined in Example I above; and 1.3 pounds of chocolate flavor were combined together. This mixture was stirred together at a temperature of 40° F. for two minutes. The resulting product had a solids content of: ______________________________________ AS A AS A LIQUID MIX DEHYDRATED MIX ______________________________________ butterfat 4% 14.5% nonfat milk solid* 11% 40.0% fructose 10.5% 38.2% stabilizer .7% 2.6% chocolate flavor 1.3% 4.7% Total solids 27.5% 100% ______________________________________ 23.7% whey protein concentrate The above product was pasteurized by heating at 175° F. for about 25 seconds. Following pasteurization, the product was homogenized by use of a single stage homogenizer at 2200 psi. A soft ice cream product was prepared from the above-noted homogenized mix by freezing at 19° F. for a short period. The resulting product had excellent taste and sweetness, and very good texture and body. The calorie content was about 115 calories per 100 grams as compared to 150 calories for a comparable sucrose-sweetened product. The product had a very high potential overrun. The amount of overrun for soft serve will vary between about 35 and 100%, depending upon the particular kind of soft serve machine used. EXAMPLE IV Exammple III was repeated with the exception that the chocolate flavor was eliminated, and the components were combined in the following amounts: 1.65 pounds cream, 83.63 pounds of milk, 1.9 pounds powdered skim milk, 3.0 pounds of Protec powder (whey protein concentrate), 8.5 pounds fructose and 0.7 pounds of the microcrystalline cellulose containing stabilizer of Example I. The resulting product had a solids content of: ______________________________________ AS A AS A LIQUID MIX DEHYDRATED MIX ______________________________________ butterfat 4.0% 15.5% nonfat milk solids* 12.0% 48.0% fructose 8.5% 33.7% stabilizer .7% 2.8% Total solids 25.2% 100% ______________________________________ *23.7% whey protein concentrate EXAMPLE V Example IV is repeated with the exception that the amount of fructose varied as follows: 6.5% fructose with 3.0% honey, 4.5% fructose with 3.0% honey, related results are obtained. Since honey is approximately 37% fructose, the sweetening agent in both instances was at least 75% fructose. EXAMPLE VI The following table is exemplary of ice milk type dessert mixes in both the form of a liquid mixture and a dry powder which fall within the scope of this invention. These mixes may be used to prepare either hard or soft serve products. All ingredients are listed in percent by weight. __________________________________________________________________________ EXAMPLE VI FORMULA: A B C D E Ingredient L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 __________________________________________________________________________ Butterfat 3.0 11.5 6.0 18.8 5.0 17.4 5.0 18.1 7.0 28.0 .sup.3 Milk Solids 3.0 .0 12.0 37.5 13.0 45.3 11.0 39.9 9.0 36.0 Not Fat Fructose 9.5 36.5 11.0 34.4 10.0 34.9 9.0 32.6 7.0 28.0 Stabilizer 0.5 2.0 .7 2.2 .7 2.4 .6 2.2 .5 2.0 Egg Solids -- -- 1.0 3.1 -- -- 2.0 7.2 .5 2.0 Flavor 1.3 4.0 -- -- -- -- 1.0 4.0 Total Milk 16.0 18.0 56.3 18.0 62.7 16.0 58.0 16.0 64.0 Solids Total Food 26.0 100.0 32.0 100.0 28.7 100.0 27.6 100.0 25.0 100.0 Solids __________________________________________________________________________ .sup.1 Liquid Mixture .sup.2 Dry Powder .sup.3 Approximately 25% whey protein concentrate having a protein conten of about 35% In the above table, the milk solids not fat can be provided by a number of sources such as powdered skim milk, protein whey concentrate (a partially delactosed whey containing about 25-75% whey protein), dry buttermilk and condensed skim milk. Sources which provide both butterfat and milk solids not fat include cream, whole milk, plain milk powder, condensed whole milk, butter and evaporated milk. EXAMPLE VII The following table is also exemplary of ice cream type dessert mixes in both the form of a liquid mixture and a dry powder. These mixes may be used to prepare either hard or soft serve products. All ingredients are listed in percentage by weight. __________________________________________________________________________ EXAMPLE VII FORMULA: F G H I J Ingredient L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 __________________________________________________________________________ Butterfat 10.0 28.6 10.0 28.0 11.0 30.4 12.0 32.5 12.0 32.9 .sup.3 Milk Solids 13.0 37.1 12.0 33.6 11.0 30.4 14.0 37.8 10.0 27.4 Not Fat Fructose 9.0 25.7 10.0 28.0 12.0 33.1 10.0 27.0 12.0 32.9 Stabilizer .5 1.4 .7 2.0 .5 1.4 1.0 2.7 .5 1.4 Egg Solids 1.0 2. 3.0 8.4 .5 1.4 -- -- 2.0 5.4 Flavor 1.5 4.3 -- -- 1.2 3.3 -- -- -- -- Total Milk 23.0 65.7 22.0 61.6 22.0 60.8 26.0 70. 22.0 60.3 Solids Total Food 35.0 100.0 35.7 100.0 36.2 100.0 37.0 100.0 36.5 100.0 Solids __________________________________________________________________________ .sup.1 Liquid Mixture .sup.2 Dry Powder .sup.3 Approximately 25% whey protein concentrate having a protein conten of about 35% EXAMPLE VIII The table in this example shows both liquid and dry mixes which may be used to prepare hard ice cream products. __________________________________________________________________________ EXAMPLE VIII FORMULA: K L M N O P Ingredient L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 __________________________________________________________________________ Butterfat 13.0 30.8 15.0 33.7 18.0 37.9 20.0 46.5 16.0 42.3 14.0 35.9 .sup.3 Milk Solids 14.0 33.2 13.0 29.1 12.0 25.3 11.0 25.6 10.0 26.5 10.0 25.6 Not Fat Fructose 12.0 28.5 13.0 29.1 13.0 27.4 10.0 23.3 11.0 29.1 10.5 26.9 Stabilizer 1.2 2.8 .8 1.8 1.2 2.5 1.0 2.3 .8 2.1 1.0 2.6 Egg Solids 2.0 4.7 1.5 3.4 2.0 4.2 1.0 2.3 -- -- 3.5 9.0 Flavor -- -- 1.3 2.9 1.3 2.7 -- -- -- -- -- -- Total Milk 27.0 64.0 28.0 62. 30.0 63.2 31.0 72.1 26.0 68.8 24.0 61.5 Solids Total Food 42.2 100.0 44.6 100.0 47.5 100.0 43.0 100.0 37.8 100.0 39.0 100.0 Solids __________________________________________________________________________ .sup.1 Liquid Mixture .sup.2 Dry Powder .sup.3 Approximately 25% whey protein concentrate having a protein conten of about 35% EXAMPLE IX The table which follows is illustrative of the ice milk and ice cream-type dessert mixes in both the form of a liquid mixture and a dry powder which can be prepared using whey protein concentrates having different protein contents and fructose-based sweeteners having a minor amount of a sweetening agent other than fructose. These are exemplary only and various other combinations are also possible, without departing from the scope of the invention. For example, the whey protein concentrate could be eliminated and the MSNF could be comprised solely of nonfat dry milk, dry buttermilk, low lactose skim milk or combinations thereof in any ratio or proportion. In addition, minor amounts of sodium caseinate and/or whey could also be added. When using whey, it would be beneficial to use a high protein milk solid such as sodium caseinate since whey is relatively low in protein, i.e., 12-14%. In this regard, an isolated milk-derived protein such as sodium caseinate could be used to increase the protein content of any combination of nonfat milk solids. However, without the presence of the whey proteins provided by the whey protein concentrate or isolated whey protein, the body texture and storage qualitites of the products may be somewhat lacking. __________________________________________________________________________ EXAMPLE IX FORMULA: Q R S T U Ingredient L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 L.sup.1 D.sup.2 __________________________________________________________________________ Butterfat 6.0 19.9 7.0 21.5 14.0 33.1 18.0 36.5 16.0 34.4 Milk Solids 8.0.sup.3 26.5 9.0.sup.5 27.6 11.0.sup.7 26.0 11.0.sup.9 22.3 14.0.sup.11 30.1 Not Fat Fructose-Based 14.0.sup.4 46.4 13.0.sup.6 39.9 15.0.sup.8 35.5 18.0.sup.10 36.5 12.0.sup.12 25.8 Sweetener Stabilizer 1.7 5.6 1.5 4.6 1.3 3.1 .9 1.8 2.0 4.3 Egg Solids 0.5 1.6 .5 1.5 1.0 2.3 1.4 2.9 1.0 2.2 Flavor -- 1.6 4.9 -- 1.5 3.2 Total Milk 14.0 46.4 16.0 49.1 25.0 59.1 29.0 58.8 30.0 64.5 Solids Total Food 30.2 100.0 32.6 100.0 42.3 100.0 49.3 100.0 46.5 100.0 Solids __________________________________________________________________________ .sup.1 liquid mixture .sup.2 dry powder .sup.3 35% whey protein concentrate having a protein content of about 35% .sup.4 90% fructose, 10% high conversion corn syrup solids .sup.5 15% whey protein concentrate having a protein content of about 50% .sup.6 90% fructose, 10% aspartame .sup.7 30% whey protein concentrate having a protein content of about 60% .sup.8 90% fructose, 10% sucrose .sup.9 10% whey protein concentrate having a protein content of about 75% .sup.10 80% fructose, 15% regular conversion corn syrup solids, 5% honey .sup.11 20% whey protein concentrate having a protein content of 50% and 30% dry buttermilk .sup.12 95% fructose, 5% aspartame The premix mentioned above for preparing the dessert mixtures will preferably contain all of the essential ingredients, with the exception of egg solids, to prepare an ice cream or ice milk mix merely by the addition of appropriate amounts of milk, cream or a mixture of milk and cream. Some milk solids are essential to the premix and preferably include the whey protein concentrates or isolated whey proteins. However, it is possible to add other milk solids such as nonfat dry milk, powdered whole milk, buttermilk solids, powdered cream, caseinate salts, low lactose skim milk and the like. Since the premix is an ideal mix to market to individuals for the preparation of homemade ice cream or ice milk, it is preferred to make the premix essentially complete thus requiring only the addition of a combination of milk and cream according to a set recipe to prepare a final frozen product. The recipe could call for the addition of fresh eggs and specify different flavorings to be added. In the alternative, the eggs, if desired, could be added to the premix as whole egg solids or egg yolk solids and various flavorings could also be added to the premix. It, therefore, follows that the essential ingredients of the premix include the fructose-based sweetener (preferably pure fructose), some milk solids preferably including whey protein concentrate and stabilizers and emulsifiers. However, because of regulatory limitations as to the amount of whey protein concentrate which can be used, it may be necessary to incorporate powdered skim milk, dry buttermilk, caseinate salts, low lactose skim milk or some other source of MSNF into the premix. As will be demonstrated in the tables and examples which follow, a combination of cream and skim milk can supply the requisite fat content to make a frozen dessert, but can supply only about 40 to 70% of the MSNF required. Therefore, some MSNF which preferably includes whey protein concentrate or a combination of whey protein concentrate plus MSNF from another source, such as skim milk powder, dry buttermilk, caseinate salts or low lactose skim milk, must supply from 30 to 60% of the total dessert MSNF in the premix. Since at least 10% of the total MSNF in the final dessert mix is preferably whey protein concentrate, the minimum ratio of whey protein concentrate to nonfat dry milk in the premix will preferably be at least 0.2:1 and may be entirely whey protein concentrate. Most preferably, the ratio of whey protein concentrate to other sources of nonfat dry milk solids in the premix will vary between about 0.5:1 to 5:1. In order to satisfy the required solids content in the prepared frozen dessert, the premix will contain between about 10 and 54% MSNF preferably having a whey protein concentrate content as mentioned above, 37 to 86% of a fructose-based sweetener, and 2 to 21% stabilizer and emulsifier. When using pure crystalline fructose, the percentages will vary slightly to about 13 to 54% MSNF having the whey protein concentrate content mentioned above, 37 to 83% pure crystalline fructose and 2 to 21% stabilizer and emulsifier. Egg solids or egg yolk solids sufficient to supply 0.25 to 1.5% egg yolk solids in the frozen dessert may be added. This will generally vary between about 1.25 and 10.5% by weight egg yolk solids in the premix. The premix is thoroughly blended to provide a uniform mixture which is then packaged in sealed moisture-tight containers. The containers may vary in size depending upon how they are to be used. The premix may be packed in bulk in drums and shipped to dairies or ice cream plants for mixing with large quantities of cream and milk in commercial operations. Smaller containers may be utilized by restaurants or fast food outlets having soft serve machines. Still smaller packets or containers may be provided for home use. Since there are various combinations of milk and cream which can be combined, the following tables are exemplary only. Fat content of cream and MSNF content of cream and skim milk may vary according to locality, season or government regulations. However, based on the following tables, one skilled in the art can readily determine how to blend a proper premix to be used with a particular cream and milk combination. TABLE I __________________________________________________________________________ COMPOSITION IN PERCENT BY WEIGHT OF VARIOUS DESSERT MIXES OBTAINED BY COMBINING A PREMIX OF WHEY PROTEIN CONCENTRATE DRY SKIM MILK, PURE CRYSTALLINE FRUCTOSE, EGG YOLK SOLIDS AND STABILIZER __________________________________________________________________________ MIX NUMBER INGREDIENTS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 __________________________________________________________________________ Butterfat (from 3 3 4 4 5 5 6 6 7 8 9 10 11 11 12 cream) Whey Protein Conc. 3 4 3 3 3 4 5 3 4 5 3 4 3 4 3 MSNF From Cream, 9 10 9 10 8 9 9 10 10 8 10 11 10 10 Skim Milk & Skim Milk Powder Crystalline 9 10 9 10 9 10 9 10 9 10 9 10 10 11 10 Fructose Egg Yolk Solids .5 .5 .5 .5 .5 .5 .5 .5 .5 .5 .5 .5 .5 .5 .5 Stabilizer & 1.25 1.25 1.25 1.25 1.25 1.25 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 .75 Emulsifier TOTAL SOLIDS 25.75 28.75 26.75 28.75 26.75 29.75 30.5 30.5 31.5 32.5 32.5 36.5 35.5 37.5 35.25 Water 74.25 71.25 73.25 71.25 73.25 70.25 69.5 69.5 68.5 67.5 67.5 63.5 64.5 62.5 64.75 __________________________________________________________________________ MIX NUMBER INGREDIENTS 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 __________________________________________________________________________ Butterfat (from 12 13 13 14 14 15 15 16 16 17 17 18 18 19 20 cream) Whey Protein Conc. 4 4 3 4 5 4 3 3 4 3 3 3 4 4 MSNF From Cream, 9 8 10 9 9 9 9 8 9 9 8 7 8 7 9 Skim Milk & Skim Milk Powder Crystalline 11 10 11 10 11 10 11 10 11 11 12 11 12 11 12 Fructose Egg Yolk Solids .5 .5 .5 .5 .5 .5 .5 .5 .5 1.0 1.0 1.0 1.0 1.0 1.0 Stabilizer & .75 .75 .75 .75 .75 .75 .75 .75 .75 .75 .75 .75 .75 .75 .75 Emulsifier TOTAL SOLIDS 37.25 36.25 38.25 38.25 40.25 39.25 39.25 38.25 41.25 41.75 41.75 40.75 43.75 42.75 45.75 Water 62.75 63.75 61.75 61.75 59.75 60.75 60.75 61.75 58.75 58.25 58.25 59.25 56.25 57.25 54.25 __________________________________________________________________________ TABLE II __________________________________________________________________________ POSSIBLE COMBINATIONS OF CREAM, SKIM MILK AND SKIM MILK POWDER REQUIRED TO MAKE DESSERT MIXES OF TABLE I (COMBINATION PLUS WHEY PROTEIN CONCENTRATE, FRUCTOSE, EGG YOLK SOLIDS AND STABILIZER SHOULD EQUAL __________________________________________________________________________ 100) MIX NUMBER INGREDIENTS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 __________________________________________________________________________ Cream 40% 7.5 7.5 10 10 12.5 12.5 15 15 17.5 20 22.5 25.0 27.5 27.5 30 Skim Milk 76.92 73.63 74.33 72.14 72.83 69.54 67.21 67.21 64.63 62.04 60.53 54.65 54.24 52.05 53.02 8.8% MSNF Skim Milk 1.83 3.12 1.92 3.11 .92 2.21 2.29 3.29 3.37 1.46 3.47 4.85 3.76 3.95 2.73 Powder Cream 35% 8.57 8.57 11.42 11.42 14.28 14.28 17.14 17.14 20 22.84 25.71 28.56 31.43 31.43 34.28 Skim Milk 75.84 72.55 72.89 70.70 71.03 67.74 65.07 65.07 62.11 59.17 57.29 51.05 50.29 48.09 48.72 8.8% MSNF Skim Milk 1.84 3.13 1.94 3.13 .94 2.23 2.29 3.29 3.39 1.49 3.50 4.89 3.78 3.98 2.75 Powder Cream 30% Fat 10.0 10.0 13.33 13.33 16.66 16.66 20.0 20.0 23.33 26.66 30.0 33.33 36.66 36.66 40.0 Skim Milk 74.42 71.13 71.0 68.80 68.67 65.38 62.21 62.21 58.80 55.37 53.03 46.33 45.10 42.91 43.04 8.8% MSNF Skim Milk 1.83 3.12 1.92 3.12 .92 2.21 2.29 3.29 3.37 1.47 3.47 4.84 3.74 3.93 2.71 Powder Cream 20% Fat 15.0 15.0 20.0 20.0 25.0 25.0 30.0 30.0 35.0 40.0 45.0 50.0 55.0 55.0 60.0 Skim Milk 69.43 66.14 64.34 62.15 60.34 57.05 52.24 52.24 47.15 42.06 38.06 29.67 26.78 24.58 23.06 8.8% MSNF Skim Milk 1.82 3.11 1.91 3.10 .91 2.20 2.26 3.26 3.35 1.44 3.44 4.83 3.72 3.92 2.69 Powder __________________________________________________________________________ MIX NUMBER INGREDIENTS 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 __________________________________________________________________________ Cream 40% 30 32.5 32.5 35 35 37.5 37.5 40 40 42.5 42.5 45 45 47.5 50 Skim Milk 50.82 50.43 48.23 46.74 44.55 44.13 44.13 43.76 40.47 38.40 38.40 37.99 34.70 34.31 29.53 8.8% MSNF Skim Milk 2.93 1.82 4.02 3.01 3.20 3.12 3.12 1.99 3.28 3.35 2.35 1.26 2.55 1.44 3.72 Powder Cream 35% 34.28 37.14 37.14 40 40 42.86 42.86 45.71 45.71 48.57 48.57 51.43 51.43 54.29 57.14 Skim Milk 46.52 45.75 43.55 41.70 39.51 38.74 38.74 37.98 34.69 32.28 32.28 31.52 28.23 27.47 22.32 8.8% MSNF Skim Milk 2.95 1.86 4.06 3.05 3.24 3.15 3.15 2.06 3.35 3.40 2.40 1.30 2.59 1.49 3.79 Powder Cream 30% Fat 40.0 43.33 43.33 46.66 46.66 50.0 50.0 53.33 53.33 56.66 56.66 60.0 60.0 63.33 66.66 Skim Milk 40.84 39.61 37.41 35.09 32.89 31.66 31.66 30.43 27.14 24.27 24.27 23.02 19.73 18.50 12.88 8.8% MSNF Skim Milk 2.91 1.81 4.01 3.00 3.20 3.09 3.09 1.99 3.28 3.32 2.32 1.23 2.52 1.42 3.71 Powder Cream 20% Fat 60.0 65.0 65.0 70.0 70.0 75.0 75.0 80.0 80.0 -- -- -- -- -- -- Skim Milk 20.87 17.96 15.77 11.79 9.59 6.69 6.69 3.78 .49 -- -- -- -- -- -- 8.8% MSNF Skim Milk 2.88 1.79 3.98 2.96 3.16 3.06 3.06 1.97 3.26 -- -- -- -- -- -- Powder __________________________________________________________________________ The above Tables were calculated using the following data: Cream 40% = 40% Fat, 5.35% MSNF, 54.65% H.sub.2 O Cream 35% = 35% Fat, 5.69% MSNF, 59.31% H.sub.2 O Cream 30% = 30% Fat, 6.24% MSNF, 63.76% H.sub.2 O Skim Milk = 8.8% MSNF, 91.2% H.sub.2 O Skim Milk Powder = 100% MSNF TABLE III __________________________________________________________________________ DRY PREMIX COMPOSITION IN PERCENT BY WEIGHT WHICH CAN BE COMBINED WITH THE CREAM AND SKIM MILK (EXCLUDING SKIM MILK POWDER) COMBINATIONS OF TABLE II TO MAKE THE DESSERT MIXES OF TABLE I (100 MINUS LBS CREAM AND SKIM MILK IN COMBINATION EQUALS LBS OF PREMIX REQUIRED) __________________________________________________________________________ MIX NUMBER INGREDIENTS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 __________________________________________________________________________ Fructose 57.73 53.00 57.43 55.96 61.39 55.68 50.59 56.22 50.36 55.66 53.03 49.14 54.80 53.79 58.89 Whey Protein 19.24 21.20 19.14 16.79 20.46 22.27 28.11 16.86 22.38 27.82 17.68 19.66 16.43 19.56 17.67 Concentrate Skim Milk Powder 11.80 16.53 12.25 17.46 6.21 12.31 12.87 18.49 18.86 8.18 20.45 23.83 20.55 19.32 16.08 Stabilizer 8.02 6.62 7.98 6.99 8.53 6.96 5.62 5.62 5.60 5.56 5.89 4.91 5.48 4.89 4.42 Egg Yolk Solids 3.21 2.65 3.20 2.80 3.41 2.78 2.81 2.81 2.80 2.78 2.95 2.46 2.74 2.44 2.94 TOTAL 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 __________________________________________________________________________ MIX NUMBER INGREDIENTS 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 __________________________________________________________________________ Fructose 57.38 58.58 57.08 54.79 53.79 54.50 54.50 61.54 56.26 57.57 62.80 64.66 59.11 60.44 58.57 Whey Protein 20.87 23.43 15.57 21.92 24.45 21.80 21.80 18.46 20.46 15.70 15.70 17.64 19.70 21.98 14.64 Concentrate Skim Milk Powder 15.23 10.67 20.87 16.44 15.65 16.89 16.89 12.30 16.88 17.58 12.35 7.41 12.56 7.97 18.25 Stabilizer 3.91 4.39 3.89 4.11 3.67 4.09 4.09 4.62 3.84 3.92 3.92 4.41 3.70 4.12 3.66 Egg Yolk Solids 2.61 2.93 2.59 2.74 2.44 2.72 2.72 3.08 2.56 5.23 5.23 5.88 4.93 5.49 4.88 TOTAL 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 __________________________________________________________________________ Various other combinations are possible as the above tables do not include all variables within the scope of the invention. In these tables, the whey protein concentrate varies between bout 23 to 36% of the total MSNF, and the ratio of whey protein concentrate to skim milk powder varies from about 0.75:1 to 3.5:1. The cream and skim milk provides between about 40 to 65% of the total MSNF. The fructose content can also be varied to provide 7-14% solids in the final product. The amounts of stabilizer package and egg yolk solids can also vary. IN addition, other ingredients such as flavorings, fruits, nuts and other additives can be added. The protein content of the whey protein concentrate can vary anywhere from about 25 to 75% protein or the equivalent amount of isolated whey protein. The pure crystalline fructose sweetener may be substituted with a fructose containing up to 25% of another sugar or combination of sugars. When less than pure fructose is used, the overall sugar content must be raised unless the added sweetening agent is a non-carbohydrate such as aspartame or saccharin. On a dry basis, the premix ingredients in Table III varied within the following ranges: whey protein concentrate (14-29%), powdered skim milk (6-24%), crystalline fructose (49-65%), stabilizer (3-9%) and egg yolk solids (2-6%) which constitutes a preferred range. As previously stated, the egg yolk solids need not be included in the premix; hence, the range for egg yolk solids may vary from 0 to 6%. The following examples illustrate a premix and cream/skim milk combinations which can be used to prepare the dessert mixes of Examples I and II. Since most whipping cream sold in supermarkets contain about 35% butterfat, the examples are based on cream containing 35% fat, 5.69% milk solids not fat and 59.31% water; and on a skim milk containing 8.6% milk solids not fat and 91.4% water. EXAMPLE X A homogeneous premix was prepared by blending the following ingredients: ______________________________________ Weight % Weight ______________________________________ 10.25 lbs Pure Crystalline Fructose 59.18 2.87 lbs Whey Protein Concentrate 16.57 2.85 lbs Skim Milk Powder 16.45 .85 lbs Stabilizer and Emulsifier 4.91 .50 lbs Egg Yolk Solids 2.89 17.32 lbs 100.00 ______________________________________ The above premix was added to the liquid mixture consisting of 45.71 lbs. cream having a fat content of 35%; and 36.97 lbs. of skim milk having an MSNF content of 8.6%. The resulting liquid mixture had a solids content of 39.10% consisting of the following ingredients: ______________________________________ Percent ______________________________________ Fructose 10.25 Fat 16.00 Nonfat Milk 11.50 Solids* Stabilizer .85 Egg Yolk Solids .50 39.10 ______________________________________ *25.0% whey protein concentrate The liquid mixture can be pasteurized, homogenized and frozen as in Example I. EXAMPLE XI A homogeneous premix was prepared by blending the following ingredients: ______________________________________ Weight % Weight ______________________________________ 12.00 lbs Pure Crystalline Fructose 55.76 2.87 Whey Protein Concentrate 13.34 2.55 lbs Skim Milk Powder 11.85 .85 lbs Stabilizer and Emulsifier 3.95 .50 lbs Egg Yolk Solids 2.32 2.75 lbs Cocoa 12.78 21.52 lbs 100.00 ______________________________________ The above premix was added to a liquid mixture consisting of 40.0 lbs. of cream having a fat content of 35%; and 38.48% lbs. of skim milk having a MSNF content of 8.6%. The resulting liquid mixture had a solids content of 41.1% consisting of the following ingredients: ______________________________________ Percent ______________________________________ Fructose 12.00 Fat 14.00 Nonfat Milk 11.00 Solids* Stabilizer .85 Egg Yolk Solids .50 Cocoa 2.75 41.10 ______________________________________ *26.1% whey protein concentrate This liquid mixture can also be pasteurized, homogenized and frozen as in Example II. EXAMPLE XII Alternate premixes suitable for use in blending with the cream and skim milk of Example X are as follows: EXAMPLE XII __________________________________________________________________________ - I II III WEIGHT WEIGHT WEIGHT (% WEIGHT) (% WEIGHT) (% WEIGHT) __________________________________________________________________________ PREMIX INGREDIENT Crystalline Fructose 10.25 (59.18) 10.25 (59.18) 10.25 (59.18) Whey Protein Concentrate 1.73.sup.1 (9.99) 3.90.sup.3 (22.52) 5.25.sup.5 (30.31) Other Nonfat Milk Solids 3.99.sup.2 (23.03) 1.82.sup.4 (10.50) .47.sup.6 (2.71) Stabilizer & Emulsifier .85 (4.91) .85 (4.91) .85 (4.91) Egg Yolk Solids .50 (2.89) .50 (2.89) .50 (2.89) 17.32 (100) 17.32 (100) 17.32 (100) SOLIDS CONTENT OF FINAL PRODUCT Crystalline Fructose 10.25 10.25 10.25 Fat 16.00 16.00 16.00 Whey Protein Concentrate 1.73.sup.1 3.90.sup.3 5.25.sup.5 Other Added MSNF 3.99.sup.2 1.82.sup.4 .47.sup.6 MSNF from Cream & 5.78 5.78 5.78 Skim Milk Stabilizer & Emulsifier .85 .85 .85 Egg Yolk Solids .50 .50 .50 39.10 39.10 39.10 __________________________________________________________________________ .sup.1 75% Protein and provides 15% of total MSNF .sup.2 60% Powdered Skim Milk, 40% Dry Buttermilk .sup.3 55% Protein and provides 34% of total MSNF .sup.4 Skim Milk powder .sup. 5 35% Protein and provides 45.6% of total MSNF .sup.6 Dry buttermilk powder EXAMPLE XIII The following table is illustrative of MSNF contents of premix compositions not containing whey protein concentrate suitable for use in combination with added quantities of skim milk and cream to make a frozen dessert. For purposes of illustration, the premix contains 57% by weight fructose, 36% by weight MSNF and 7% by weight stabilizer. ______________________________________ EXAMPLE XIII FORMULA: Ingredient A B C D E F G H ______________________________________ Nonfat Dry 27 14 31 15 -- 32 16 15 Milk Dry Butter- -- 14 -- 15 28 -- 16 15 milk Sodium -- 8 -- -- 4 4 4 2 Caseinate Low Lactose 9 -- -- 3 -- -- -- 2 Skim Milk Isolated -- -- 5 3 4 -- -- 2 Whey Protein TOTAL 36 36 36 36 36 36 36 36 MSNF Fructose 57 57 57 57 57 57 57 57 Stabilizer 7 7 7 7 7 7 7 7 100 100 100 100 100 100 100 100 ______________________________________ While the invention has been described above in terms of its best known embodiment, it is not to be limited to the specific examples or tables, but is to be accorded the full protection allowed by the following claims. What is claimed is: 1. A liquid dessert mix suitable for freezing having a solids content of between about 24 and 49% by weight wherein the percent by weight solids comprises about:(a) 2 to 25% butterfat, (b) 8 to 15% nonfat milk solids selected from the group consisting of nonfat dry milk, dry buttermilk, whey, whey protein concentrate, sodium caseinate, low lactose skim milk powder and mixtures thereof wherein at least 10% by weight of said non fat milk solids consists of a whey protein concentrate having a protein content of between 25 and 75% by weight: (c) 7 to 18% of a fructose-based sweetener containing at least 75% by weight fructose selected from the group consisting of substantially pure crystalline fructose, frutose non-carbohydrate sweetener combinations and fructose carbohydrate combinations, (d) 0 to 1.5% egg yolk solids, and (e) 0.5 to 2.5% of a stabilizer and emulsifier wherein the stabilizer contains from about 20 to 50% by weight of a microcrystalline cellulose. 2. A powdered dessert premix according to claim 1 wherein the fructose-based sweetener is a fructose non-carbohydrate sweetener combination. 3. A powdered dessert premix according to claim 2 wherein the non-carbohydrate sweetener is selected from the group consisting of aspartame and saccharin. 4. A powdered dessert premix according to claim 1 wherein the fructose-based sweetener is a combination of fructose and an additional carbohydrate sweetener. 5. A powdered dessert premix according to claim 4 wherein the additional carbohydrate sweetener is a member selected from the group consisting of glucose, sucrose, maltose, corn syrup solids, invert sugar solids, dried honey and mixtures thereof. 6. A liquid dessert mix according to claim 1 wherein the fructose-based sweetener is substantially pure crystalline fructose. 7. A liquid dessert mix according to claim 6 wherein the solids content is between about 24 to 34% by weight wherein the percent by weight solids comprises about 2 to 7% butterfat, 8 to 15% non fat milk solids, 7 to 11% crystalline fructose, 0 to 1.0% egg yolk solids and 0.5 to 2.5% stabilizer and emulsifier. 8. A liquid dessert mix according to claim 7 wherein the percent by weight solids comprises about 3 to 6% butterfat, 11 to 13% nonfat milk solids, 8 to 10% crystalline fructose, 0.25 to 1.0% egg yolk solids and 0.7 to 2.0% stabilizer and emulsifier. 9. A liquid dessert mix according to claim 8 wherein the whey protein concentrate accounts for between about 20 and 35% of the nonfat milk solids. 10. A liquid dessert mix according to claim 9 wherein the butterfat content is supplied by liquid cream, and the nonfat milk solids content is supplied by liquid cream, liquid skim milk, whey protein concentrate and one or more members selected from the group consisting of nonfat dry milk, dry buttermilk, whey, sodium caseinate and low lactose skim milk powder. 11. A liquid dessert mix according to claim 10 wherein the protein content of the whey protein concentrate is about the same as the protein content of skim milk powder. 12. A liquid dessert mix according to claim 6 wherein the solids content is between about 35 and 49% by weight wherein the percentage by weight solids comprises about 8 to 20% butterfat, 10 to 14% nonfat milk solids, 9 to 14% crystalline fructose, 0 to 15% egg yolk solids and 0.5 to 2.5% stabilizer and emulsifier. 13. A liquid dessert mix according to claim 12 wherein the percent by weight solids comprises about 12 to 18% butterfat, 10 to 13% nonfat milk solids, 10 to 13% crystalline fructose, 0.5 to 1.5% egg yolk solids, and 0.7 to 2.0% stabilizer and emulsifier. 14. A liquid dessert mix according to claim 13 wherein the whey protein concentrate accounts for between about 20 to 35% of the nonfat milk solids. 15. A liquid dessert mix according to claim 14 wherein the butterfat content is supplied by liquid cream, and the nonfat dry milk solids is supplied by liquid cream, liquid skim milk, whey protein concentrate, and one or more members selected from the group consisting of nonfat dry milk, dry buttermilk, whey, sodium caseinate and low lactose skim milk powder. 16. A liquid dessert mix according to claim 15 wherein the protein content of the whey protein concentrate is about the same as the protein content of skim milk powder. 17. A liquid dessert mix according to claim 1 wherein the fructose-based sweetener is a fructose non-carbohydrate sweetener combination. 18. A liquid dessert mix according to claim 17 wherein the non-carbohydrate sweetener is selected from the group consisting of aspartame and saccharin. 19. A liquid dessert mix according to claim 1 wherein the fructose-based sweetener is a combination of fructose and an additional carbohydrate sweetener. 20. A liquid dessert mix according to claim 19 wherein the additional carbohydrate sweetener is a member selected from the group consisting of glucose, sucrose, maltose, corn syrup, invert sugar, honey and mixtures thereof. 21. A dessert mix according to claim 6 which has been dehydrated to a powdered form. 22. A dessert mix according to claim 7 which has been dehydrated to a powdered form. 23. A dessert mix according to claim 8 which has been dehydrated to a powdered form. 24. A dessert mix according to claim 9 which has been dehydrated to a powdered form. 25. A dessert mix according to claim 10 which has been dehydrated to a powdered form. 26. A dessert mix according to claim 11 which has been dehydrated to a powdered form. 27. A dessert mix according to claim 12 which has been dehydrated to a powdered form. 28. A dessert mix according to claim 13 which has been dehydrated to a powdered form. 29. A dessert mix according to claim 14 which has been dehydrated to a powdered form. 30. A dessert mix according to claim 15 which has been dehydrated to a powdered form. 31. A dessert mix according to claim 16 which has been dehydrated to a powdered form. 32. A dessert mix according to claim 17 which has been dehydrated to a powdered form. 33. A dessert mix according to claim 18 which has been dehydrated to a powdered form. 34. A dessert mix according to claim 19 which has been dehydrated to a powdered form. 35. A dessert mix according to claim 20 which has been dehydrated to a powdered form. 36. A powdered dessert premix to be added to a combination of liquid milk and cream to prepare a frozen dessert which comprises about:(a) 10 to 54% by weight non fat dry milk solids selected from the group consisting of non fat dry milk, dry buttermilk, whey, whey protein concentrate, sodium caseinate, low lactose skim milk power and mixtures thereof and wherein whey protein concentrate having a protein content of between about 25 to 75% by weight is present such that the ratio of whey protein concentrate to the remainder of the non fat milk solids is at least 0.2:1, (b) 37 to 86% by weight of a fructose-based sweetening agent containing at least 75% by weight fructose selected from the group consisting of substantially pure crystalline fructose, fructose non-carbohydrate sweetener combination and fructose carbohydrate combinations, (c) 2 to 21% by weight stabilizer and emulsifier wherein the stabilizer contains from about 20 to 50% by weight of a microcrystalline cellulose, and (d) 0 to 10% by weight egg yolk solids. 37. A powdered dessert premix according to claim 36 wherein the fructose-based sweetening agent is substantially pure crystalline fructose. 38. A powdered dessert premix according to claim 37 containing about 13 to 54% by weight nonfat milk solids, 40 to 83% by weight substantially pure crystalline fructose and 2 to 21% by weight stabilizer and emulsifier. 39. A powdered dessert premix according to claim 38 wherein the nonfat milk solids consist of a mixture of whey protein concentrate and other nonfat milk solids from the nonfat milk solids group, in a ratio of 0.5:1 to 5:1 whey protein concentrate to said other nonfat milk solids. 40. A powdered dessert premix according to claim 39 comprising 14 to 29% whey protein concentrate, 6 to 24% other nonfat milk solids, 49 to 65% crystalline fructose, 3 to 9% stabilizer and 0 to 6% egg yolk solids. 41. A powdered dessert premix according to claim 40 wherein the egg yolk solids content is between 2.0 and 6.0% by weight. 42. A powdered dessert premix according to claim 41 wherein the whey protein concentrate contains approximately the same protein concentration as skim milk powder or dry buttermilk. 43. A powdered dessert premix according to claim 41 wherein the premix also contains a flavoring. 44. A powdered dessert premix according to claim 43 wherein the flavoring is a chocolate flavoring. 45. A powdered dessert premix according to claim 41 containing no egg yolk solids. 46. A powdered dessert premix according to claim 38 wherein the nonfat milk solids are entirely a whey protein concentrate.

1983-03-15

en

1985-02-05

US-18358662-A

Screen and pneumatic separator Aug. 30, 1966 R. w. MOCRE 3,269,532 SCREEN AND PNEUMATIC SEPARATOR Filed March 29, 1962 2 Sheets-Sheet 1 INVENTOR Aug. 30, 1966 R. w. MOORE SCREEN AND PNEUMATIC SEPARATOR Filed March 29. 1962 2 Sheets-Sheet 2 lI/I/I/ll/ l gm 16 B0 Ill/ll lI/I INVENTOR Ralph W M 007 6 ATTORNEYS United States Patent 3,269,532 SCREEN AND PNEUMATIC SEPARATOR Ralph W. Moore, Hagerstown, Md., assignor to The Pangborn Corporation, Hagerstown, Md., a corporation of Delaware Filed Mar. 29, 1962, Ser. No. 183,586 7 Claims. (Cl. 209-33) This invention relates to a separating device for separating particulate matter, more particularly for such particles that are used in blasting equipment for cleaning, peening, abrading and the like. Particle separating devices have been used with the above type of equipment for a considerable period of time, but are generally bulky and cumbersome. In addition, present separating devices operate by employing a strong negative pressure or vacuum and replace the displaced air by means of open ports or the like which direct the air along an. intersecting pathway with respect to a stream or curtain of particles. This type of arrangement usually requires a relatively large exhaust system and, in addition, tends to be inefficient since it is difficult to obtain an even equal flow through all parts. Separating devices in present use are generally considered efficient if not more than 2% by weight of the separated particulate material is foreign matter. Such impurities substantially reduce the working life of throwing wheels and wheel vanes, sometimes by as much as 90% in the case of sand and similar impurities. It is an object of the present invention to provide particle-separating devices that are more simple to construct and use, have greater efiiciency, and a higher capacity per unit size. It is a further object of the present invention to reduce the amount of impurities or foreign bodies in sorted particulate matter, particularly abrasive particulate matter, to below the 2% value heretofore considered satisfactory. Other objects and a fuller understanding of the invention may be obtained by referring to the following description and claims, taken in conjunction with the accompanying drawings wherein: FIG. 1 is a perspective partly broken away of a separator according to the present invention; FIG. 2 is a vertical cross-section taken along line 22 of FIG. 3 of the separator of FIG. 1; FIG. 3 is a plan view of the separator of FIGS. 1 and 2 with top removed; FIG. 4 illustrates a modification of FIG 2; and FIG. 5 is a cross-section taken along line 5-5 of FIG. 3. In accordance with the present invention a vibrating positive-pressure device is employed for separating small particles from a stream containing these particles and also containing elongated foreign bodies such as wires having diameters close to those of the particles, said device having a screen with a mesh size suitable for passing the desired particles, vibrating means connected to the screen for vibrating it, and supply structure connected to deliver the stream to the screen so that it flows over the screen as the screen vibrates. An apron attached at one end of the screen receives the unsorted particles and feeds them to the screen, said apron being essentially arranged in a horizontal position for spreading the particles and causing wires or similar foreign bodies to settle to a tilt that approaches the horizontal, so that such foreign bodies move over the screen without falling through it, while the particulate matter is screened. In addition, the apparatus can be made particularly compact by separating the fines from the heavier particles with a parallel arrangement of two curtain-type streams of the particles, using blowers to deflect the fines from both streams into the space between these streams. Patented August 30, 1966 With reference to FIGS. 1, 2 and 3, a preferred embodiment of the present invention is shown having sides 27A through D, a roof 52 with hinged service doors 54, and a vibratory screen 5. The screen can consist of any abrasive-resistant heavy duty industrial screening material such as wire having a mesh size adapted to the particular purpose to which the separating device is applied. For general blasting purposes it should pass particles not substantially larger than about /8" in diameter. It is conveniently fitted with a frame 7 having a top plate 12, side members, and a discharge extension 8. The frame, in turn, is suspended from roof 52 at convenient fixed pivot points 53 (FIG. 5) by links 9, 9A which permit the frame to vibrate up and down as well as to and fro. The links can hang free in extended manner, or as shown they can be urged toward a folded position as by coil springs (not shown). Vibrating means such as a journal 11 (FIG. 1) carrying a rotatably mounted shaft 35 and an eccentrically rotatably-rnounted weight 39, is connected to an electric motor 13 or other convenient source of rotational energy. A convenient method for transmitting rotational movement to the weight 39 is shown as a belt 15 running from a driving wheel 32 on motor 13 to a driven wheel keyed to the shaft 35. It is helpful to keep the motor and drive elements shielded from the dust particles, particularly when abrasive particles are being treated, as by employing sealed bearings for movable drive and suspension parts, and also by mounting the motor 13 on roof 52 in the manner shown in FIG. 1. Screen 5 is supplied with particles by feed duct 17 having outlet 18. An outlet only about 3 to 6 inches high is particularly useful in preventing wires or the like from entering the screening area in an upright or vertical position and passing through the mesh of the screen. Duct opening 18 opens onto apron 58 which is secured to frame 7 and arranged in a generally horizontal position. As the stream of material to be separated is dropped onto the apron, it flows over its discharge lip 51 (FIGS. 1 and 3) onto the screen and across it. Coarse material too large to fall through the mesh of the screen is discarded through a coarse discharge port 16 by means of extension 8 secured to frame 7, and allowed to drop into coarse discharge chute 20. Frame 7 also includes a distribution chamber 21 below the screen and having a slot 22 through which the particles dropping through the mesh of screen 5 are spread out in an elongated curtain to fall onto catch plate 23. Secured at both ends of distribution chamber 21, as shown in FIGS. 1, 2 and 5, are dams 26 and 26B, dam 26 being equipped with a lip extension 26A for handling overflow and directing it into overflow chute 20A through port 20B (FIG. 1). Chute 20A can empty into the recycling path of the blastant particles so that they can return for another passage through the separator. Catch plate 23 is arranged beneath frame 7 and fixedly mounted in end Walls 27A and 27B. This plate serves to split the screened particles into two parallel streams or curtains overflowing from both longitudinal edges. Blowers 25 are conveniently mounted on both side walls 27C and 27D at a point beneath catch plate 23 and arranged to flow in generally horizontal direction transverse to the pathway of overflow particles falling from the trough, In this way dust and fines are displaced inwardly to be collected in fine hopper 29 having inwardly disposed guide plates G and the recoverable particles fall into recovery bin 31. The blowers are preferably equipped with wide flat nozzles 25A for blowing a short wide jet of air which impinges in a uniform manner against the entire width of the particle curtains falling from trough 23. The blower nozzles are shown at the same level so that the air flow from one side does not extend to the curtain on the opposing side where it could have an undesired effect on the dropping particles. Air is removed from the separator by means of conduit 34 whichis shown as connected to the top of fine hopper 29. The conduit can have its remote end leading to any convenient suction device such as that forming part of the blasting equipment with which the separator is used. The usable particles received in bin 31 are conveniently removed through recovery line 36 or any other suitable emptying device. The recovered particles can be recycled directly to the blasting operation. The slot 22 at the bottom of distribution chamber 21 (Ref. FIGS. 1 and 2) can be made adjustable as by using one or two movable side plates 24 which can be slidably held against the floor of the distribution chamber. Such an arrangement may be conveniently and autmatically operated by remote control, whereby slot 22 can be momentarily enlarged to clear any small obstruction or blockage which interrupts the feeding of screened particles onto plate 23. Apparatus of the type described above is very effective for separating core wires and the like, and sand, from recycled blastant particles. By keeping the apron 58 horizontal, such wires are permitted to settle down to approach a horizontal position as they move across the apron. These wires are used in large quantities in pres ent-day casting techniques to hold mold portions such as cores in place. Blasting operations are particularly desirable for cleaning up such castings and many of the cores, including core wires and the like which still adhere to the castings when they are loaded into the blasting machine, Provision is made in such machines to permit core wires that are separated from the castings to drop through gratings or similar devices so that they do not accumulate to jam the blasting apparatus. These wires accordingly are automatically removed from the blasting zone along with the blasting particles and have to be separated by a separate treatment. Blast projectors such as throwing wheels, are commonly used to project the blastant particles against the castings or other work pieces which are readily damaged or jammed by wires, and it is accordingly very important to completely remove the Wires from the recycled blastant. The generally horizontal position of the apron 58 along with the use of a shallow layer of entering particles on this apron assures the settling down of the wires. A suitable shallowness of layers can be anything up to about two or three inches. In such condition the mixture leaving the lip 51 of the apron 58 (Ref. FIGS. 1 and 3) has all its wires lying down so close to the horizontal that they move across the screen 5 without falling through its mesh. This happens whether the screen is merely vibrated in one dimension either up and down or to and fro, or it is gyrated in a circular or elliptical path, or even if it is subjected to vibration of the type that acts on the particles so as to propel them forward. The use of a trough or catch plate to split the long thin curtain-like stream. falling from slot 22 into two parallel elongated streams is a particularly desirable feature of the present invention. It enables the use of opposed air streams to provide the fines separation in an extremely compact manner. The horizontal separation between the split curtains should be between one and five feet. Less separation will cause both of the oppositely directed blown streams of air to interfere with each other before they produce the desired deflection of the fines and wider separation makes the entire apparatus so much more bulky as to defeat the compactness which the invention otherwise provides. Chute 20A is an overflow for the trough 21 and is used to indicate that the trough is filled with particles along its entire length. A dam 26 (FIG. 5) at the overflow end of the trough helps to assure that particles move cornpletely along the entire length of this trough so that there is a positive feed through all portions of slot 22. This gives the falling curtains of particles their greatest Width and thereby increases the effectiveness of the separation. FIG. 4 illustrates a modification of FIG. 2 in which frame 7 is mounted on brackets attached to side walls 27C and 27D by means of pneumatic cushions 3t? conveniently bolted to brackets 28 and the sides 27C and 27D. In this construction, the vibrating device is shown as a self-contained actuator 49 such as electromagnets energized by the standard 60-cycle electric current, to produce an alternating magnetic field that vibrates the screen at a frequency of cycles per second. Alternatively, the pneumatic cushions 30 can have their interiors connected to a source of pulsing pressure that causes the cushions to expand and contract and to correspondingly vibrate the frame 7. Limit stops or bumpers can be effectively used with such a pulsing technique, or with any other vibrating arrangements, to act as jars against which the frame 7 strikes as it is vibrated. This improves the screening action by increasing the severity of each vibration swing. Because this unit is often preferably mounted near the top of a throwing wheel machine and as much as 20 to 30 feet above floor level, it is desirable to minimize the transmission of vibration from the screen to the support structure. Isolating the vibrating part of the unit preferably by air cushions accomplishes this result very efiiciently. It is another feature of the present invention that the amount of air blown in by means of blowers 25 is not so great as to overburden the suction equipment for the blasting chamber to which conduit 34 is normally connected. If desired, the amount of excess air blown in across the poured curtains can be reduced as by having the intakes of blowers 25 connected to the interior of the separator as indicated in FIG. 4. The blowers will then essentially recirculate air already present in the separator. A single separator according to the present invention can have more than one delivery outlet 36. For this purpose the hopper shaped bin 31 can be divided into two or more small hopper-shaped compartments each having its own outlet. The individual outlets can be separately connected to different throwing wheels or the like for reblasting. The trough 21 with its slotted floor need not be vibrated with the screen, and if desired, this trough can merely be fixed in place between the walls of the compartment. Since it is obvious that many changes and modifications can be made in the above-described details without departing from the nature and spirit of the invention, it is to be understood that the invention is not to be limited to said details except as set forth in the appended claims. What is claimed is: 1. A device for separating small particles from a stream containing these particles and also containing elongated foreign bodies having diameters close to those of the particles, said apparatus having a substantially horizontal screen with a mesh size suitable for passing the desired particles, vibrating means connected to the screen for vibrating it, supply structure connected to deliver the stream to the screen so that it flows over the screen as the screen vibrates, said supply structure including feed means for delivering the stream in a flat shallow layer, said screen having an attached apron for receiving the particles and feeding them onto the screen, said apron being arranged in a substantially horizontal position causing elongated foreign bodies deposited thereon to approach the horizontal and pass over said screen without falling through it, while the particles pass through as screened particles, pouring means below said screen connected to pour two parallel elongated narrow curtain type streams of said screened particles down through an open space, blower structure connected to blow air horizontally in said open space and across stream, said blower structure including a plurality of blowers facing each other the blown air moving from outside both streams to the zone between these streams, suction means having a suction inlet in said zone for exhausting the blown air, a pair of separator partitions below said open space to split the falling streams into lighter particles that are deflected into said Zone by blown air, heavier particles that are not so deflected, a collector for collecting the deflected particles of both streams, and a collector for separately collecting the undeflected particles of both streams. 2. A device according to claim -1 in which said screen is mounted on a frame, said frame having downwardly extended sides arranged for funneling said screened particles onto said pouring means adapted for distributing said particles as a plurality of evenly-distributed curtains of particles. 3. A device according to claim 1 in which said blower structure is equipped with means for recirculating air from within said particle separator to said blower structure. 4. A device according to claim 1 wherein said pouring structure is a V-shaped trough, feed structure being below said screen and above said trough, said feed structure having downwardly converging sides, and said sides of said feed structure being spaced from each other to 6 form a slot with said slot being disposed above the root of the V. 5. A device according to claim 4 wherein adjusting means are connected to said sides of said feed structure for controlling the size of said slot. 6. A device according to claim 1 wherein the intake of each of said blowers is disposed within said open space. 7. A device according to claim 1 wherein said feed means includes a flat feed duct having a longer width than its height, and said feed duct being disposed adjacent said apron for delivering the stream in a flat shallow layer. References Cited by the Examiner UNITED STATES PATENTS 82,431 9/1868 Mills 209-134 148,229 2/ 1874 Mayers 209-265 253,546 2/1882 McNeil 209-263 693,025 2/1902 Jessup 209-263 955,714 4/1910 Steedman 209-134 X 2,866,547 12/1958 Gladfelter 209-135 X 2,941,667 6/1960 Hilgartner 209-134 3,005,547 10/1961 Freeman 209-134 X 3,036,708 5/1962) Freeman 209-134 3,087,615 4/1963 Powell 209-134 FRANK W. LUTTER, Primary Examiner. RICHARD A. OLEARY, Examiner. 1. A DEVICE FOR SEPARATING SMALL PARTICLES FROM A STREAM CONTAINING THESE PARTICLES AND ALSO CONTAINING ELONGATED FOREIGN BODIES HAVING DIAMETER CLOSE TO THOSE OF THE PARTICLES, SAID APPARATUS HAVING A SUBSTANTIALLY HORIZONTAL SCREEN WITH A MESH SIZE SUITABLE FOR PASSING THE DESIRED PARTICLES, VIBRATING MEANS CONNECTED TO THE SCEEEN FOR VIBRATING IT, SUPPLY STRUCTURE CONNECTED TO DELIVER THE STREAM TO THE SCREEN SO THAT IT FLOWS OVER THE SCREEN AS THE SCREEN VIBRATES, SAID SUPPLY STRUCTURE INCLUDING FEED MEANS FOR DELIVRING THE STREAM IN A FLAT SHALLOW LAYER, SAID SCREEN HAVING AN ATTACHED APRON FOR RECEIVING THE PARTICLES AND FEEDING THEM ONTO THE SCEEEN, SAID APRON BEING ARRANGED IN A SUBSTANTIALLY HORIZONTAL POSITION CAUSING ELONGATED FOREIGN BODIES DEPOSITED THEREON TO APPROACH THE HORIZONTAL AND PASS OVER SAID SCREEN WITHOUT FALLING THROUGH IT, WHILE THE PARTICLES PASS THROUGH AS SCREENED PARTICLES, POURING MEANS BELOW SAID SCREEN CONNECTED TO POUR TWO PARALLEL ELONGATED NARROW CURTAIN TYPE STREAMS OF SAID SCREENED PARTICLES DOWN THROUGH AN OPEN SPACE, BLOWER STRUCTURE CONNECTED TO BLOW AIR HORIZONTALLY IN SAID OPEN SPACE AND ACROSS STREAM, SAID BLOWER STRUCTURE INCLUDING A PLURALITY OF BLOWERS FACING EACH OTHER THE BLOWER AIR MOVING FROM OUTSIDE BOTH STREAMS TO THE ZONE BETWEEN THESE STREAMS, SUCTION MEANS HAVING A SUCTION INLET IN SAID ZONE FOR EXHAUSTING THE BLOWN AIR, A PAIR OF SEPARATOR PARTITIONS BELOW SAID OPEN SPACE TO SPLIT THE FALLING STREAMS INTL LIGHTER PARTICLES THAT ARE DEFLECTED INTO SAID ZONE BY BLOWN AIR, HEAVIER PARTICLES THAT ARE NOT SO DEFLECTED, A COLLECTOR FOR COLLECTING THE DEFLECTED PARTICLES OF BOTH STREAMS, AND A COLLECTOR FOR SEPARATELY COLLECTING THE UNDEFLECTED PARTICLES OF BOTH STREAMS.

1962-03-29

en

1966-08-30

US-78275985-A

Wet surface tracking resistance for an ignition distributor cap ABSTRACT The combination of radial and concentric ribs on the interior surface of an ignition distributor cap provide increased wet surface tracking resistance to help isolate spark to the electrodes. BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a breakerless ignition distributor and system as may be used with internal combustion engines for automotive vehicles, for example. The available space in an automotive engine compartment is very limited and the desire to reduce weight is high. These factors dictate that distributors be of compact size and employ lightweight components which require a minimum of adjustments and alignment while being able to withstand the shock and vibration in the engine compartment. The subject invention advances the art of ignition distributors which work with electronic ignition systems, which, in most cases, are now computerized in motor vehicles, along with Hall Effect switches or electrical pick-ups and associated electrical and solid state electronic circuitry. Such a distributor illustrative of the prior art is illustrated in U.S. Pat. No. 4,165,726 to Helmer which is hereby incorporated by reference. The ignition distributor employs features of an insertless distributor cap further described in U.S. Pat. No. 4,338,895 to Lennis and Handy, which is also hereby incorporated by reference. In U.S. Pat. No. 2,918,913 to Guiot, attention is invited to FIG. 2A which illustrates metal disk 19 with apertures 20 which interact with oscillating coil 7. Attention is also invited to FIG. 4A showing metal disk 21 and aperture 22 interacting with coil 9. U.S. Pat. No. 3,789,168 to Meyer et al. illustrates an ignition distributor device for use with vehicle engine ignition systems equipped with electronically advanced spark timing angle controllers. U.S. Pat. No. 4,342,292 to House et al. illustrates an annular insulating rib 41 on a rotatable member 40. U.S. Pat. No. 4,393,849 to Sae illustrates a variable ignition distributor which is designed to furnish a high voltage spark to one spark plug and a low voltage spark to another spark plug. U.S. Pat. No. 4,464,142 to Bridges et al. discloses an ignition distributor and a shaft coupler. U.S. Pat. No. 4,470,385 to Burk et al. illustrates another distributor for use with an internal combustion engine. U.S. Pat. No. 4,485,796 to Boyer illustrates still another example of ignition distributors. Attention is invited to FIG. 6 and more specifically to metallic plate member 50 with radially extending slots 54 and 56. U.S. Pat. No. 4,519,362 to Arakawa illustrates a signal rotor 111 with a cylinder discrimination signal producing magnet 116. This is best shown in FIG. 10A. Also illustrated in a slit disk type signal rotor 121 with a cylinder discrimination signal producing slit 126. This is best illustrated in FIG. 11A. It is an object of the subject invention to minimize the size of the distributor. It is a further object of the invention to reduce the size of the distributor by providing a window-in-vane on an interrupter assembly which reduces the number of vanes needed by one by eliminating a second interrupter assembly which carries the now eliminated vane. It is another object of the subject invention to provide a switching technique to work with the subject window-in-vane and Hall Effect sensors in the ignition distributor. It is another object of the subject invention to provide a distributor cap which works in communication with a rotor to provide a labyrinth structure to minimize the effects of arcing and to provide ribs to interfere with and lengthen the wet surface path along the inside of the distributor cap. It is still a further object of the subject invention to provide a distributor cap and rotor which are designed to work together to create a pumping action when the rotor is in motion which urges the charged and ionized atmosphere inside the distributor cap upward and out of the cap through a vent tower. It is still another object of the subject invention to provide an improved spark shield which helps to isolate the spark occurring between the rotor electrode and the distributor cap electrodes from the Hall Effect sensors which are concurrently in communication with the interrupter assembly. Another object is to provide a switch plate assembly to carry two pairs of Hall Effect generators and sensors. This application is one of six applications filed on the same date, all commonly assigned and having similar specification and drawings, the six applications being identified below: ______________________________________ U.S. Ser. No. Title ______________________________________ 782,757 Window-In-Vane Interrupter And Switch Plate Assembly For An Ignition Distributor 782,758 Labyrinth For An Ignition Distributor Cap And Rotor Assembly With Atmospheric Purging Action 782,759 Wet Surface Tracking Resistance For An Ignition Distributor Cap 782,760 Spark Shield And Inlet Air Vent For An Ignition Distributor 782,761 Plastic Hub And Interrupter Assembly For An Ignition Distributor 782,767 Ignition Distributor - Hall Effect Sensor Switching System And Method ______________________________________ DESCRIPTION OF THE DRAWINGS 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 in the accompanying drawings in which: FIG. 1 is a perspective view of the subject ignition distributor showing where it connects to the various engine components; FIG. 2 is an exploded perspective view of the main parts of the subject ignition distributor; FIG. 3 is a cut-away perspective view of the subject ignition distributor illustrating the various parts; FIG. 4A is a sectional view of the distributor cap without the spark plug electrodes, but with the coil electrode in place; FIG. 4B is an interior view of the distributor cap without the coil electrodes and spark plug electrodes; FIG. 5A is a cut-away of the rotor illustrating the rotor staking nubs protruding from the rotor prior to being ultrasonically worked thereby trapping the rotor electrode to the rotor; FIG. 5B is a sectional view of the rotor with the rotor electrode in place and showing the rotor staking nubs after being ultrasonically worked; FIG. 5C is a plan view of the rotor with the rotor electrode; FIG. 6A is a plan view of the spark shield; FIG. 6B is a sectional view of the spark shield taken along section lines 6B--6B of FIG. 6A; FIG. 7A is a plan view of the switch plate assembly; FIG. 7B is a sectional view of the switch plate assembly taken along section lines 7B--7B of FIG. 7A; FIG. 8A is a plan view of the retainer; FIG. 8B is a sectional view of the retainer; FIG. 9A is a plan view of the interrupter; FIG. 9B is a side view of the interrupter; FIG. 9C is a cut-away view of the interrupter showing the window-in-vane; FIG. 10A is a cut-away of the hub illustrating the hub staking nubs protruding from the rotor prior to being ultrasonically worked thereby trapping the interrupter to the hub; FIG. 10B is a sectional view of the hub with the interrupter in place and showing the hub staking nubs after being ultrasonically worked; and FIG. 10C is a plan view of the interrupter and hub, assembled. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the ignition distributor 20 is shown in perspective. The distributor communicates with the coil 80 via a wire connected to coil tower 28 and running to coil 80. The coil 80 is then connected to the engine control computer 82 with the ability to store data, mathematical relationships, programs and methods and with the ability to receive data from sensors, make computations using data and the stored relationships, programs and methods, and to translate the results of those computations to control signals for the sensors and transducers which control the operation of an internal combustion engine 100. The computer 82 is also able to act as timer and counter for various purposes. The transducers controlled include the coil 80, distributor 20 and fuel injectors grouped in two banks 86 and 88. The ignition distributor 20 also communicates with spark plugs 84 which are in communication with the internal combustion chambers of engine 100. The ignition distributor 20 is mounted and grounded to the engine 100 via drive coupling 54, seal 78, and fastened to the engine 100 by way of a clamp (not shown) in communication with mounting flange 76. The ignition distributor 20 is in communication with the engine control computer 82 via wires 41 and connectors 42. The engine control computer 82 gets its power from the vehicle battery and power supply system both schematically shown as 83. Referring now to FIG. 2 which is an exploded perspective view of the subject ignition distributor 20, several main parts are shown; distributor cap 24, rotor 32, spark shield 38, switch plate assembly 40, housing 44, interrupter 46, metal shutter or vanes 50, drive shaft 52, and stem portion 74, along with drive coupling 54. Referring now to the distributor cap 24, the spark towers 26 house spark plug electrodes (shown in the Lennis, Handy patent) which are connected to spark plug wires which in turn communicate with the spark plugs 84 of the engine 100. (For simplicity, only one of the spark plug connections is shown in FIG. 1.) The spark plug electrodes communicate with the rotor 32 via rotor electrode 34 as the rotor moves about a shaft 52 passing the rotor electrode 34 near to the spark plug electrodes. Also shown on the distributor cap 24 is bored coil tower 28 which houses the coil electrode 60 and its associated parts (shown in FIG. 3 and FIG. 4A) for communication with the rotor 32 and coil 80. The distributor cap 24 is generally of a dome shape and is designed to mate with the bowl shaped housing 44 thereby entrapping intervening parts, such as the rotor 32, spark shield 38, switch plate assembly 40 and interrupter 46, along with shaft 52. Provided with the distributor cap 24 to allow tight communication with the intervening parts previously listed and the housing 44 are flanges 22 which contain holes (not visible) for mounting screws 23. The screws 23 communicate with the switch plate assembly 40 through flanges 43 appended from the switch plate assembly 40. Through the flanges 43 are holes 43A designed to accept screws 23. The screws then are driven into the bowl shaped housing 44 into threaded holes 45. Another tower on the dome shaped distributor cap 24 is vent tower 30. The vent tower 30 provides a port 31A through which the atmosphere inside the ignition distributor 20 can be vented. The rotor 32 carries a rotor electrode 34 for communication with the spark plug electrodes (not shown) affixed to the spark towers 26. The type of electrodes employed are similar to those illustrated in U.S. Pat. No. 4,338,895 to Lennis and Handy and the construction of the spark towers 26 is likewise similar. This structure is adequately described in the Lennis and Handy patent which is incorporated by reference. Also incorporated by reference is the U.S. Pat. No. 4,165,726 to Helmer. The rotor 32 has a cylindrical shaped member 33, the top portion of which accepts the rotor electrode 34 via slot 35. The cylindrical shaped member 33 is open at both ends, the upper portion 33A being provided for communication between the coil electrode 60 and its associated parts, shown in FIG. 3 and FIG. 4A, and the rotor electrode 34. The bottom opening 33B of the cylindrical shaped member 33 allows communication with shaft 52. The shaft 52 has notch 53 to mate with a key 33C (shown in FIG. 5A) contained inside the lower portion 33B of cylindrical shaped member 33 to provide tight communication between rotor 32 and shaft 52. The cylindrical shaped member 33 will be further described in conjunction with FIG. 5A, FIG. 5B and FIG. 5C. Spark shield 38 is affixed to switch plate assembly 40 by means of a retainer 36. The spark shield 38 covers Hall Effect generator and sensor units 55, 55A, 56 and 56A shown in FIG. 3 and shields them from spark. This will be further explained in conjunction with FIG. 6A and FIG. 6B. There are two sets of Hall Effect generators (55 and 56) and sensor circuits (55A and 56A), only one of which is shown in the cut-away perspective of FIG. 3. Each Hall Effect sensor circuits 55A and 56A is connected to the engine control computer 82 by means of wires 41 and connectors 42. The bowl shaped housing 44 is designed to accept the interrupter 46 inside the bowl. The bowl shaped lower housing has an opening 72 shown in FIG. 3 to accept the shaft 52. The shaft 52 is in communication with the interrupter 46 by means of a plastic hub 48. The interrupter 46 is ultrasonically staked to the hub 48. This ultrasonic staking operation is also employed to connect the rotor electrode 34 to the rotor 32. The interrupter 46 is provided with a vane or metal shutter 50 for each cylinder contained in the engine 100. The particular embodiment shown is for a four cylinder engine and four vanes are provided. One of the vanes in the interrupter 46 contains a window and is called a windowed shutter or window-in-vane 58, this is shown in cut-away perspective in FIG. 3. The bottom portion of the bowl shaped housing 44 is stem portion 74. This portion is designed to communicate with the engine 100 and mount the ignition distributor 20 firmly thereto. Affixed to the end of the stem portion 74 which is designed to communicate with the engine 100 is drive coupling 54. The purpose of the drive coupling 54 is to communicate with the engine's crankshaft, silencer shaft or equivalent. This drive coupling will move in accordance with the engine's crankshaft or silencer shaft etc. (a design choice) and rotate the shaft 52 and thereby the interrupter 46 and connected rotor 32. The end of the ignition distributor 20 which communicates with the engine 100 for mounting purposes involves the end to which drive coupling 54 is affixed. The drive coupling end is inserted into a hole provided in the engine 100 communicating with the appropriate shaft inside the engine 100. The stem portion 74 is further inserted into the engine 100 and a seal is provided between the two and is shown as seal 78. Mounting flange 76 is provided on stem portion 74 to communicate with a clamp (not shown) to firmly affix the ignition distributor 20 in place and help to retain its position in the engine compartment of an automobile in which the engine 100 is mounted. Referring to FIG. 3, illustrated is a cut-away perspective of the ignition distributor 20. The ignition distributor 20 is shown in full assembly with all of the intervening parts. The generally dome shaped distributor cap 24 has spark towers 26 and a center bored coil tower 28, along with a vent tower 30. Vent tower 30 is made up of a vent stem 31 and a vent cap 29. The vent stem 31 is provided with a port 31A (shown in FIG. 4B) through to the inside of distributor cap 24. The vent cap 29 is affixed to the vent stem 31 onto a concentric stem 27 which is smaller in diameter than stem 31. The hole through stem 31 communicates with the atmosphere outside of distributor cap 24 via gap 30A. In other words, vent cap 29 does not seal off the hole in stem 31 and concentric stem 27, but merely shields it and still allows communication between the inside of ignition distributor cap 24 and the atmosphere outside of cap 24 via port 31A through stem 31, concentric stem 27, cap 29 to gap 38. The center electrode for connection to the coil from the ignition distributor 20 is shown as electrode 60. Electrode 60 is placed inside bored coil tower 28 and is spring loaded. The spring loading is in its relaxed state with the cap in an unassembled condition with the rest of the intervening parts. Therefore, when the rotor 32 communicates tightly with the rest of the assembly and the distributor cap 24, a portion of the center electrode 60 is urged toward the top of tower 28 and the spring 61 (shown in FIG. 4A) is in its compressed position thereby urging continuous contact with rotor electrode 34 which is ultrasonically staked to rotor 32. This is further explained in conjunction with FIG. 4A. The distributor cap 24 is affixed to the bowl shaped housing 44 by means of flanges 22 and screws 23 which are tightened into threaded holes 45 on the flanged platform section 70 of bowl shaped housing 44. Also shown in FIG. 3 is the interaction between the rotor 32, the cylindrical member 33 and the rest of the intervening parts. It can be seen that the rotor 32 and distributor cap 24 also form a labyrinth structure to prevent transmittal of the spark entering the ignition distributor 20 at coil electrode 60 from traveling anywhere but to rotor electrode 34. Entrapping the spark shield 38 to the switch plate assembly 40 is retainer 36. Retainer 36 is composed of a segmented annular ring 37 shown in more detail in FIGS. 8A and 8B and two tabs 36A fixed to legs 36B. The spark shield 38 is a dome shaped structure with stiffening ribs 39. It is of the same approximate diameter as the switch plate assembly 40 and is designed to interlock with it at pockets 90 around the circumference shown in FIG. 7A and FIG. 7B. The center of the dome shaped spark shield 38 is a circular opening 73 designed to match up with the similar circular opening 73A and switch plate assembly 40. The retainer 36 is inserted through opening 73 through dome shaped spark shield 38 until the legs 36B force the connected tabs 36A through the switch plate assembly 40. At this point, the tabs 36A protrude over the center opening 73A of the switch plate assembly 40 until tabs 36A lock it in place. The retainer 36 thusly holds spark shield 38 to switch assembly 40. Switch plate assembly 40 holds two Hall Effect generators 55 and 56 and sensor circuits 55A and 56A (only one of which is shown in FIG. 3). The switch plate assembly 40 provides mounting brackets 63 and slots 62 for the generators 55 and 56 and back plates 64 for sensor circuits 55A and 56A by which the Hall Effect signal is received. There is a gap 66 between the Hall Effect generators 55 and 56 as mounted in brackets 63 and the back plate 64 such that the interrupter's metal shutters or vanes 50 and 58 can pass through the gap 66 as they rotate with interrupter 46. The Hall Effect sensor circuits 55A and 56A sense the presence or absence of the metal vanes 50, along with the presence or absence of window-in-vane 58 and its parts, right window-in-vane member 57, window 58A, and left window-in-vane member 59. The switch plate assembly 40 is shown in greater detail in FIG. 7A and FIG. 7B and its corresponding description. The window-in-vane 58 likewise will pass through this gap. The presence or absence of a metal vane 50 or a portion of window-in-vane 58 will cause a difference in the signal received by one of the Hall Sensors 55A and 56A. In other words, the presence of window-in-vane 58 causes a difference in the output signal from the Hall sensor circuits or pick-ups 55A and 56A as the portions of window-in-vane 58 pass near the sensor circuits 55A and 56A. In other words, as right window-in-vane member 57, window 58A and/or left window-in-vane member 59, all parts of window-in-vane 58, interrupt the Hall Effect signal, a magnetic field, generated by Hall Effect generators (magnets) 55 or 56, a different output from sensor circuits 55A or 56A is produced than that by the interruption of the same Hall signal by a non-windowed vane. The interrupter 46 is ultrasonically staked with hub staking nubs 47 to a plastic hub 48 which has a bottom flange 48A onto which the interrupter 46 is placed. See FIG. 10A, FIG. 10B and FIG. 10C. There are holes 46A in the interrupter 46 through which hubs 47 are placed and protrude through the interrupter 46. The ultrasonic staking operation melts material like nubs 47 such that the interrupter 46 is staked to the plastic hub 48. The plastic hub 48 also has a cylindrical portion 48B which has an opening therethrough to communicate with shaft 52 and the other concentrically mounted intervening parts to the ignition distributor 20. This is further illustrated in FIG. 10, FIG. 10A and FIG. 10B and the corresponding description. The stem portion 74 of the bowl shaped housing 44 comprises an opening 72 to communicate with shaft 52. It is through shaft 52 that the action of the drive coupling 54 is communicated to the rest of the ignition distributor parts to help produce the desired signal and spark distribution patterns. The stem portions 74 further comprises a mounting flange 76 which will accept a mounting clamp (not shown) to firmly affix the ignition distributor 20 to the engine 100. A seal 78 is provided at the end of stem portion 74 to seal the action and operation of the drive coupling 54 from the outside atmosphere. Drive coupling 54 communicates with the interior of the engine 100 by interacting with the crankshaft or silencer shaft (or equivalent) to produce a rotating motion which thereby engages the shaft 52 and generates the rotating motion inside the distributor 20. Referring to FIG. 4A, the distributor cap 24 is shown in a sectional view with coil electrode 60 in place. As shown in the spring 61 and carbon contact rod 60A which provides a spring loading action which urges electrical contact between coil electrode 60 by way of carbon contact rod 60A contacting rotor electrode 34. The coil electrode 60 and accompanying spring loaded parts are placed in bored coil tower 28. Spark plug electrodes (not shown) are placed in spark tower 26. The spark plug electrodes protrude into the interior of distributor cap 24 through spark plug electrode slots 106 for eventual communication with the rotor electrode 34 as it rotates about the center axis of the distributor 20 via shaft 52. Also illustrated in FIG. 4A are wet surface interruption ribs 102 which follow the shape of the generally domed distributor cap 24 in a radial fashion. The purpose of these ribs is to interfere with the spark path should it attempt to flow other than between the rotor electrode 34 and one of the spark plug electrodes in tower 26. This condition could occur if the inside surface 25 of the distributor cap 24 becomes contaminated with moisture and/or dirt. This contamination could attract the spark to take a path along the inside surface 25 of the distributor cap 24. When this occurs, the ribs 102 will provide sharp obstructions to the spark, forcing it to divert from the path along the inside surface 25 to the more resistant path of traveling in air. Another feature provided by the ribs 102 is to increase the inside surface area 25 by lengthening the path that a spark would have to travel thereby increasing the resistance of the path. Another rib with a similar function to ribs 102 is rib ring 103. The purpose of this ring is to further isolate the high tension electrical energy created at the juncture of electrode 60 via carbon contact rod 60A and rotor electrode 34. Rib ring 103 provides a fence around the combination of the coil electrode 60 (and its associated parts) and rotor 32. Another spark isolation feature in the ignition distributor cap 24 is a labyrinth structure defined by outer labyrinth 104 and inner labyrinth 105 in conjunction with portions of rotor 32, namely, cylindrical shaped member 33 and rotor ring 32A shown in FIG. 5A, FIG. 5B and FIG. 5C. This labyrinth structure, along with the ribs 102 and rib ring 103, provide a great amount of spark isolation on the inside surface 25 of distributor cap 24. Referring to FIG. 4B, an inside view of the distributor cap 24 is shown, further illustrating the concentric relationship between inner labyrinth 105, outer labyrinth 104, and rib ring 103. The ribs 102 depend from the rib ring 103 in a radially outward direction toward the outside edge 107 of distributor cap 24. Also provided in the distributor cap are spark plug electrode slots 106 and vent port 31A. The combined radial/concentric rib design of items 102 and 103 provide increased wet surface tracking resistance with minimal extra manufacturing material. Referring now to FIG. 5A, FIG. 5B and FIG. 5C, the rotor 32 is illustrated. In FIG. 5A a sectional view of rotor 32 illustrates the rotor staking nubs 34A on platform 32B. The nubs 34A are shown in an unworked condition prior to the assembly with rotor electrode 34 and prior to an ultrasonic staking or welding operation which will melt a portion of rotor staking nubs 34A until rotor electrode 34 is affixed to rotor 32. Rotor staking nubs 34A are shown in FIG. 5B after assembly to rotor electrode 34 and after ultrasonic staking or welding. FIG. 5B and FIG. 5C further illustrate the other portions of the rotor 32. FIG. 5B shows rotor 32 in a sectional view depicting the cylindrical shaped member 33 in an upper portion 33A and a lower portion 33B. The cylindrical shaped member 33 is interrupted by the rotor platform 32B which supports the rotor electrode. The upper portion 33A of the cylindrical shaped member 33 has a bore 33D which allows communication between coil electrode 60 (and its associated parts) and rotor electrode 34. The lower portion 33B of cylindrical shaped member 33 is also provided with a bore 33E which allows communication between rotor 32 and shaft 52. The rotor 32 is locked in position with the shaft by means of a key 33C formed on the interior surface of 33B to interrupt the bore 33E. The key 33C is in tight communication with notch 53 on shaft 52 when the rotor 32 is inserted onto the shaft 52. Also provided on platform 32B is rotor ring 32A which encircles upper portion 33A or cylindrical shaped member 33. The rotor ring 32A, as well as the upper portion 33A of cylindrical shaped member 33, is interrupted by slot 35 to allow for the insertion and affixation of rotor electrode 34 onto the platform 32B in such a way as to allow the rotor electrode 34 to communicate with the coil electrode 60 (and its associated parts) and the spark electrodes (not shown). The concentric ring rotor/cap labyrinth achieves center-to-outer cap random fire resistance. The high rotor side walls formed by 33A, in conjunction with the labyrinth rings 104 and 105, achieve cylinder-to-cylinder misfire resistance. The slot 35 is flanked by pumping surface 32C which follows the shape of the inside top of the distributor cap 24. The purpose for this mating shape is to create a pumping action between the pumping surface 32C and the inside top of the distributor cap 24. This action results in the urging of the inside atmosphere of distributor cap 24 upward and eventually out of the vent port 31A in vent stem 31 exiting the vent tower 30 via the gap 30A provided between the vent tower 30 and vent cap 29. This pumping and vent action helps reduce the possibility of component deterioration due to the presence of high tension electrical energy and the possible corrosive action of the presence of spark. The pumping surface 32C, in conjunction with the upper portion 33A of cylindrical member 33, forms a rotor side wall which is tapered to the shape of the interior of cap 24 to enhance the pumping action and to also provide crossfire protection. The extra deep barrier ring in cap 24 formed by outer labyrinth 104 and inner labyrinth 105 complements the rotor side walls and rings formed by the upper portion 33A of cylindrical member 33 along with rotor ring 32 for a labyrinth arc over protection which is relatively insensitive to any end play of shaft 52 and to any component tolerances. Referring now to FIG. 6A and FIG. 6B, the spark shield 38 is displayed in a plan view in FIG. 6A and in a sectional view in FIG. 6B. The spark shield is of generally dome shape shown in FIG. 6B and is provided with an opening 73 at its center. Stiffening ribs 39 are provided in a radially outward direction from the opening 73 toward the outer edge 39A. The diameter of the spark shield 38 is generally that of the switch plate assembly 40 and is provided on the outer edge 39A with mating means 38A at various positions around the outer edge 39A to mate with the switch plate assembly 40. The outer edge 39A is also provided with index means 38B to properly orient the spark shield 38 and mating means 38A onto the switch plate assembly 40. The mating means 38A takes the form of legs shown as 92 in FIG. 6B projecting perpendicularly down from the circumferential edge of the spark shield 38. The spark shield 38 protects the switch plate assembly 40 from high voltage discharges. The thin membrane design compresses easily under the compression load from snap retainer 36 for a tight fit. The radial ribs 39 allow full molding fill with minimal material. The spark shield 38 isolates the switch plate assembly 40 and other parts in bowl shaped housing 44 from ozone and related compounds present in the atmosphere inside the distributor 20 surrounding the electrodes. The spark shield 38 also isolates the cap 24 from oil vapor from engine 100. The spark shield 38 also improves ventilation and purging of the atmosphere inside cap 24 by limiting the cross-sectional sweep area of rotor 32. Referring to FIG. 7A and FIG. 7B, the switch plate assembly 40 is illustrated. The switch plate assembly 40 is generally of cylindrical shape to match that of the distributor cap 24. The switch plate 40 is provided with an opening 73A to match the opening 73 in the spark shield 38. The most important portions provided on the switch plate assembly are the mounting brackets 63 and slots 62 which are designed to mate with the Hall Effect generators 55 and 56 in such a fashion as to allow the generators 55 and 56 to transmit their signals to a Hall Effect sensor circuits 55A and 56A mounted in backplates 64. Space is provided by gap 66 between generators 55 and 56 and backplate 64 to allow the metal shutters or vanes 50 and 58 on interrupter 46 to pass between the generators 55 and 56 and backplates 64 as they rotate about the central axis of the distributor 20. The generators 55 and 56 are mounted on one side of the switch plate assembly 40. The wires 41 pass from the sensor circuits 55A and 56A and are routed along the bottom of the switch plate assembly 40 for eventual termination in connectors 42. The slots 62 are provided in mounting brackets 63. The brackets 63 are appended from the edge along the circular openings 73A. The reason for the symmetrical offset location between the Hall Effect generators 55 and 56 and the Hall Effect sensors 55A and 56A and their brackets 63 and backplates 64 is due to the timing requirements of the control methods and speed of the engine 100 and the speed of the engine control computer 82, along with the performance of the Hall Effect generators 55 and 56, along with the sensors 55A and 56A. Each sensor 55A and 56A contains an integrated circuit which interacts with the presence (or lack of presence) of the signal from generators 55A and 56A. The integrated circuit operates as a switch in response to the signals. The integrated circuit is activated by the presence of a range of signals from the generators 55 and 56. This range is expanded or contracted based on temperature's effect on the generators 55 and 56 and the sensors 55A and 56A. These conditions all affected the placement of the Hall Effect generators and sensors in their offset location. FIG. 7B is a sectional view of the switch plate assembly 40 illustrating the interaction between the metal shutters or vanes 50 and 58 of the interrupter 46 with the Hall Effect generators 55 and 56 and sensor circuits 55A and 56A. The generators 55 and 56 are essentially a magnet and the sensor circuits 55A and 56A are pick-up circuits which react to the presence or lack of a magnetic field from generator/magnets 55 and 56. The reaction sensed in 55A and 56A causes a voltage output to be read from wires 41. It is this output which is processed by the engine control computer 82. The legs 92 on spark shield 38 mate with and sit in pockets 90 on the switch plate assembly 40. The pockets 90 are located on the outer circumferential edge of switch plate assembly 40. When assembled, legs 92 and pockets 90 form an inlet 94 shown on FIG. 1. The inlet allows outside air to be urged into the interior of distributor cap 24 by the pumping action of rotor 32. This augments the flow of air through the cap 24 as the main source of air is inlet 94 and is not restricted by the internal components of the ignition distributor 20. Referring now to FIG. 8A and FIG. 8B, the retainer 36 is illustrated in plan and sectional views respectively. In FIG. 8A the retainer 36 is shown in plan view depicting the retainer 36 as a generally circular shape. FIG. 8B further illustrates the retainer 36 as having the general shape of a cylinder. The retainer 36 is provided with an opening 37A which is surrounded by a segmented annular ring 37. The purpose of the annular ring is to interlock with the bottom of switch plate assembly 40. Retainer 36 is also provided with tabs 36A which protrude out from the edge of legs 36B. Retainer 36 has two legs 36B both fitted with tabs 36A. The purpose for these legs and tabs is to fit through the openings 73 in spark shield 38 and opening 73A in switch plate assembly 40. The tabs 36A, when the retainer 36 is fully inserted into the opening 73 and hole 73A, lock the top of the spark shield 38 in place with the switch assembly 40. Referring to FIG. 9A, the interrupter 46 is shown in plan view. The interrupter 46 is of generally circular shape in this view and is provided with metal shutters or vanes 50 which are equal in number to the number of cylinders provided in engine 100 with the exception being that one of the metal shutters or vanes 50 is windowed and is designated as window-in-vane 58. The metal shutters or vanes 50 are illustrated in the side view shown in FIG. 9B. As is evident from the side view of FIG. 9B, the interrupter 46 takes on a cylindrical bowl shape as formed by the metal shutters or vanes 50 along with window-in-vane 58 which depend from the circular shape base 51 along its outer edge perpendicular to the surface of base 51. The interrupter is provided with holes 46A which are designed to accept hub staking nubs 47 from the hub 48. FIG. 9C illustrates window-in-vane 58 in a side view. The window-in-vane 58, like the other metal vanes 50, is formed from the circular shaped base 51 to the interrupter 46. The window 58A defines a right window-in-vane member 57 and a left window-in-vane member 59. Referring to FIG. 10A, plastic hub 48 is illustrated in a side sectional view showing the hub staking nubs 47 prior to being ultrasonically staked or welded after assembly through the holes 46A in interrupter 46. The hub 48 comprises a bottom flange 48A and a cylindrical portion 48B. The cylindrical portion 48B is affixed to the circular shaped bottom flange 48A and is central to the hub 48. The hub 48 is provided with an opening 49 to communicate with shaft 52. Referring to FIG. 10B, the hub 48 is shown after assembly to interrupter 46 and after ultrasonic staking or welding done to hub staking nubs 47. The interrupter 46 has been inserted over the hub staking nubs 47 through holes 46A in interrupter assembly 46, the ultrasonic staking operation welding the hub 48 to the interrupter 46. Also illustrated are metal vanes 50 and window-in-vane 58. Referring to FIG. 10C, a plan view is shown of the interrupter 46 assembled to the hub 48. The hub staking nubs 47 have been ultrasonically staked or welded and the vanes 50 and window-in-vane 58 are shown. The hub 48 is made of a thermoplastic polyester material. It is drilled with and mechanically pinned to the shaft 52. Although this type of assembly has been used before, new to this embodiment is the running of the hub 48 along with the affixed interrupter 46 directly on a predominantly iron-composite bearing surface (not shown) provided in bowl shaped housing 44. Previously, the thermoplastic polyester hub material was separated from the bearing surface by a hardened steel washer to protect the hub 48 from rapid wear. With this design the function of the washer is integrated into the hub 48 with land 48C. The use of the thermoplastic polyester material as a thrust mechanism in this application is considered revolutionary and has not been seen before. The experience gained from the use of the thermoplastic polyester hub with a hardened steel washer in previous designs and laboratory testing have proven that the thermoplastic polyester hardened steel hub will operate successfully without the hardened steel washer. The ignition distributor 20 is designed to work best with multi-point injection (MPI) fuel supply systems. However, with the deletion of one pair of the Hall Effect generators and sensors, and the replacement of the window-in-vane 58 with a solid metal vane 50, the distributor 20 can be used with a single point injection fuel supply system. While the present invention has been disclosed in connection with the preferred embodiment thereof, it should be understood that there may be other embodiments which fall within the spirit and scope of the invention and that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the following claims. I claim: 1. An ignition distributor cap to work with a rotor, the rotor having a cylindrical member having an upper and lower portion, each portion having a bore where a rotor ring surrounds the upper portion of the cylindrical member thereby forming an annular channel, spark plug electrodes, a coil electrode, a shaft, a bowl shaped housing and a rotor electrode in an ignition distributor for an internal combustion engine with cylinders, the ignition distributor cap comprising:a generally domed shape with a generally hollow interior and with a circular shaped bottom to mate with the bowl shaped housing; spark towers equal in number to the number of cylinders of the internal combustion engine, projecting up from the top of the dome shape and slotted to accept spark plug electrodes and allow them to protrude into the distributor cap interior for communication with the rotor electrode; a vent tower projecting up from the top of the dome shape and provided with a vent port through to the distributor cap interior to allow for the outward flow of the atmosphere inside the distributor cap and bowl shaped housing; a coil tower projecting up from the top of the dome shape and slotted to accept a coil electrode and allow it to protrude into the distributor cap interior for communication with the rotor electrode; interruption ribs which radially follow the dome shape, protruding into the hollow interior of the dome shape; a rib ring of annular shape which surrounds the coil electrode protruding into the hollow interior of the dome shape and intersecting with and providing a termination for each of the interruption ribs thereby providing spark isolation and increased wet surface tracking resistance by urging the spark to follow the less resistance path provided by the rotor electrode and the spark plug electrodes; an inner labyrinth of annular shape on the interior surface of the dome shape surrounding the coil electrode and protruding into the hollow interior of the dome shape; and an outer labyrinth of annular shape on the interior surface of the dome shape surrounding the inner labyrinth thereby forming an annular channel; the inner and outer labyrinths of the distributor cap for use in combination and inter-nesting with the rotor ring and upper portion of the cylindrical member to provide a labyrinth for increased cylinder-to-cylinder misfire resistance.

1985-10-01

en

1986-12-23

US-29760694-A

Low power consumption type thin film gas sensor ABSTRACT This invention relates to a low power consumption type thin film gas sensor and method for fabricating the same. The gas sensor includes a silicon substrate having a window in the central part of one side thereof, masking material formed on the one side thereof except the window, a supporting film formed of an etch stop layer and a glass film on the other side of the substrate, heaters and temperature sensors arranged in parallel on the supporting film facing the window, an interlayer insulation film formed on the supporting film to cover the heaters and the temperature sensors, sensing film electrodes formed on the interlayer insulation film, and a sensing film formed on the interlayer insulation film so as to cover the sensing film electrodes for sensing a particular gas. FIELD OF THE INVENTION This invention relates to a low power consumption type thin film gas sensor and fabrication method thereof, more particularly to a thin film gas sensor and fabrication method thereof which can minimize the power consumption for heating heaters thereof which heat to a specific high temperature a sensing film thereof to enhance the sensitivity of the sensing film to a particular gas by forming a supporting film of a heat generation part with a material and structure having low heat loss. BACKGROUND OF THE INVENTION A gas sensor is a sensor for sensing presence of a particular gas, there are, depending on the gas to be sensed by the sensing film of a sensor, a sensor for sensing CO, a sensor for sensing (CH3)3N gas generated when fish in a refrigerator goes bad, a sensor for sensing CH3 SH gas generated when vegetables go bad and a sensor for sensing C2 H5 OH, etc. In general, what we should take into account as basic requisite a gas sensor has to have is to be compact and low power consumptive, in addition to high sensitivity, excellent selectivity and high speed of response. Such a gas sensor contains a heater in the element to enhance the sensitivity of a sensing film to sense a particular gas by heating the sensing film to a specific temperature (normally to 200 to 500 deg. C.), while maintaining the lowest possible power consumption. In order to make the power consumption lower, the material of the heater itself should be highly efficient as a heat generating material, and loss of the heat generated in the heater to outsise should be minimized. When a heater is to be heated to a specific temperature difference ΔT, in general, the amount of heat loss P to outside is expressed as follows; P=Pm+P.sub.R +P.sub.A, where, Pm is heat loss through the supporting film of the sensor, PR is heat loss due to the radiation, and PA is heat loss through circumferential air. wherein, since the PR is relatively very small value, and the PA is small value caused by the geometry of the heating part, it is possible to reduce the heat loss P just by reducing the Pm. The heat loss through the supporting film Pm of a sensor can be expressed as follows; ##EQU1## where, K is a constant, σ is heat conductivity of the supporting film, h is thickness of the supporting film, u is width of the supporting film, and a is length of the heat generation part. As can be seen from the equation, to reduce heat loss through the supporting film, either the supporting film should be of low heat conductive material with reduced thickness, or the ratio of the length of the heating part to the width of the supporting film should be adjusted. A conventional thin film gas sensor fabricated considering the foregoing condition could have reduced the heat loss of a heater by providing, after forming a supporting film, a heater, and a sensing film on one side of a silicon wafer, a window formed by carrying out an anisotropic etching of the other side of the wafer. A supporting film of a thin film gas sensor exerts a very important influence on the characteristics such as efficiency, reliability, etc. of the sensor, depending on the structure, and the thermal, electrical and mechanical properties of the supporting film. The supporting film is formed by a silicon wafer having a supporting film formed on one side thereof which is etched from the back thereof in an etching solution until an appropriate thickness thereof is left when the etching is stopped. Such an etch stop is caused by an exposure of, in most cases, boron doped P+ type silicon layer, a silicon oxide (SiO2) film, or a silicon nitride (Si3 N4) film. Therefore, in order to form a supporting film of predetermined thickness, though it is necessary to carry out an anisotropic etching of a silicon wafer having the film formed thereon to an exact thickness, it is difficult to control forming the exact thickness of the supporting film due the occurance of small amount of etching of the boron doped silicon layer (hereinafter called "P+ -Si") or the silicon oxide film in an anisotropic etching solution (KOH water solution). However, since the silicon nitride (Si3 N4) film is not susceptible to an etching solution at all, if underlayer of the supporting film is formed of the silicon nitride (Si3 N4) film, an exact thickness of the supporting film can be obtained. FIG. 1 is a section of a conventional thin film gas sensor. Referring to FIG. 1, a thin film gas sensor includes a supporting film 2 having a silicon oxide film 2a, a silicon nitride film 2b and a silicon oxide film 2c deposited stacked on a silicon substrate 1 to a thickness of 2.5 μm, 0.2 μm, 2.5 μm, respectively, and having a NiFe metal alloy deposited on the supporting film 2, which is subjected to a patterning to form heaters 3 and temperature sensors 4. In this instant, size of the active area a of the heaters 3 is made to be 450 μm×450 μm. After forming the heaters 3 and the temperature sensors 4 on the supporting film 2 as described above, a passivation layer 5 is formed thereon using SiONx. After forming gas sensing elements 8 each having a sensing electrode 6 and a sensing film 7 on the passivation layer 5, the back of the silicon substrate 1 is subjected to an anisotropic etching in KOH water solution. This completes fabrication of a conventional thin film gas sensor 10 having a supporting film 2 formed of deposited, stacked structure of SiO2, Si3N4 and SiO2 thereon. The characteristics of the heater of a conventional thin film gas sensor is shown in FIG. 2. It can be shown that a conventional thin film gas sensor consumes 70 mw to heat the heat generation part of the heater thereof to 300 deg. C., about 340 mw/mm2 of the heat generation part, and resistence of the temperature sensor is about 700 Ω at 300 deg. C. The thin film gas sensor fabricated according to the foregoing process using, for the supporting film, single layered film of P+ -Si, SiO2 or Si3 N4, or multiple layered film of SiO2 /Si3 N4 /SiO2 has problems of having a difficulty in forming a supporting film having an exact predetermined thickness due to small amount of etch of P+ -Si or SiO2, SiO2 /Si3 N4 /SiO2 in KOH water solution during the anisotropic etching, and having a limit in reducing the power consumption of the heater due to P+ -Si and Si3 N4 having relatively high heat conduction, which leads to a greater heat loss. SUMMARY OF THE INVENTION Accordingly, the object of this invention for solving the foregoing problems is to provide a low power consumption type thin film gas sensor which can minimize the power consumption of the heater for heating to a specific high temperature the gas sensing film to enhance the sensitivity of the gas sensing film to a particular gas by forming the supporting film of the heat generation part of the gas sensor with glass having small heat loss. Another object of this invention is to provide a method for fabricating a low power consumption type thin film gas sensor which can minimize the power consumption of the heater thereof and can control the thickness of the supporting film exactly by using glass films and silicon nitride films having low heat conductivities for the supporting film. These and other objects and features of this invention can be achieved by providing a low power consumption type thin film gas sensor including a silicon substrate having a window in the central part of one side thereof, masking material formed on the one side thereof except the window, a supporting film formed of an etch stop layer and a glass film on the other side of the substrate, heaters and temperature sensors arranged in parallel on the supporting film facing the window, an interlayer insulation film formed on the supporting film to cover the heaters and the temperature sensors, sensing film electrodes formed on the interlayer insulation film, and a sensing film formed on the interlayer insulation film so as to cover the sensing film electrodes for sensing a particular gas. And, the method for fabricating a low power consumption type thin film gas sensor includes processes for depositing a silicon nitride film on one side of a silicon substrate, forming a supporting film by depositing a silicon nitride film and a glass film successively on the other side of the substrate, forming heaters and temperature sensors arranged in parallel on the supporting film, forming an interlayer insulation film on the supporting film the heaters and the temperature sensors are formed thereon, forming sensing film electrodes on the interlayer insulation film, forming a sensing film on the interlayer insulation film to cover the sensing film electrodes, forming etching window exposing the silicon substrate by carrying out etching of the parts corresponding to the temperature sensors and the heaters of the nitride film formed on the one side of the silicon substrate after completion of the sensing film forming process, and forming a window by carrying out an anisotropic etching of the exposed silicon substrate using the masking material as a mask. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a section of a conventional thin film gas sensor. FIG. 2 is a power consumption characteristic curve of a heater of the thin film gas sensor shown in FIG. 1. FIGS. 3(a) to 3(e) show processes for fabricating a thin film gas sensor in accordance with this invention. FIG. 4 is a section of the thin film gas sensor fabricated in accordance with the processes of FIGS. 3(a) to 3(e). FIG. 5 is a graph showing both power consumption of a heater required for heating a sensing film and resistance of sensors based on temperature for a thin film gas sensor in accordance with this invention. FIG. 6 is a graph showing change of sensivity of CH3SH gas based on the change of temperature for a thin film gas sensor in accordance with this invention. FIG. 7 shows the response characteristic of the sensor of this invention to CH3SH gas. FIG. 8 is a graph showing the selectivity of the sensor of this invention to various gases. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 3(a) to 3(e) show processes for fabricating a thin film gas sensor in accordance with this invention. The process for fabricating a thin film gas sensor in accordance with this invention is as follows. First, as shown in FIG. 3(a), silicon nitride (Si3 N4) films 20a and 20d are deposited on both sides of a silicon substrate 60 each to a thickness of 500 Angstroms to 2500 Angstroms with low pressure chemical vapor deposition (LPCVD) method, wherein the silicon nitride film 20d deposited at the back of the silicon substrate 60 serves as a mask at the time of carrying out anisotropic etching of the silicon substrate 60 in following process and the silicon nitride film 20a at the front thereof serves as an etch stop layer. Then, a glass film 20b is deposited with atmospheric pressure chemical vapor deposition (APCVD) method to a thickness of 5000 Angstroms to 3 um on the silicon nitride film deposited on the silicon substrate 60. A supporting film 20 having a nitride film 20a and a glass film 20b as shown in FIG. 3(b), wherein the glass film 20b, being one of PSG (phosphosilicate glass), BSG (borosilicate glass) or BPSG (borophosphosilicate glass), serves as a supporting film having low heat conductivity. Next, as shown in FIG. 3(c), heaters 30b and temperature sensors 30a are formed in parallel on the supporting film 20 formed in the foregoing process so that each of the areas of the heat generation parts of the gas sensor is to be 0.588 mm×0.588 mm. The heater 30b and the temperature sensor 30a are deposited to a thickness of about 5000 Angstroms to 3 um using metals such as Pt/Ta. In this instant, the length of the heat generation part is formed to be less than 1/2 of the width of the supporting film. The tantalum (Ta) used for the heat generation part at forming the heaters 30b and the temperature sensors 30a is deposited under a platinum (Pt) layer as a means for enhancing the adhesive force between the platinum layer and the glass film, preferably to a thicknes of 200 Angstroms to 700 Angstroms. And the platinum, being a high temperature material, can be used for the heaters as well as for the temperature sensors due to its heat generation chatacteristics and exhibits excellent agreement with resistance law based on the change of temperature. After forming the heaters and the temperature sensors in the foregoing process, an interlayer insulation film 40 is formed by depositing an silicon nitride film with sputtering method. In this invention, a silicon nitride film having an excellent insulation property and a high heat conductivity is used as the interlayer insulation film 40 for easy transfer of the heat generated in the heater 30b to a sensing film to be formed in a process to be described later. Sensing film electrodes 50a are formed by depositing metals such as Pt/Ta to a thickness of about 4000 Angstroms to 6000 Angstroms and patterning it, and a sensing film 50 is formed so as to cover the sensing film electrodes 50a. Through the foregoing process, a sensing element having sensing film electrodes 50a and a sensing film 50 as shown in FIG. 3(d). Herein, the sensing film 50 is of SnO2 doped with 1 wt % of palladium, preferably to a thinkness of 1000 Angstroms to 5000 Angstroms. After completion of the foregoing processes for the front surface of the silicon substrate 60, the silicon nitride film 20d formed at the back of the silicon substrate 60 is etched with reactive ion etching (RIE) method to form an etching window. Then the exposed silicon substrate 60 is subjected to an anisotropic etching in KOH solution using the silicon nitride film 20d at the back thereof as a mask. The progress of etch stops at the silicon nitride film 20a to obtain a thin film gas sensor as shown in FIG. 3(e). FIG. 4 is a section of of a thin film gas sensor of low power consumption type in accordance with this invention fabricated through the processes of FIGS. 3(a) to 3(e). As shown in FIG. 4, a thin film gas sensor 70 of low power consumption type in accordance with this invention includes a supporting film 20, having a silicon nitride film 20a and a glass film 20b, serving as an etch stop layer formed on one side of the silicon substrate 60, heaters 30b and temperature sensors 30a formed on the supporting film 20 arranged in parallel, an interlayer insulation film 40 formed on the supporting film 20 so as to cover the heaters 30b and the temperature sensors 30a, a sensing element having sensing film electrodes 50a and a sensing film 50 formed on the interlayer insulation film 40, a window formed on the other side of the silicon substrate 60, and a silicon nitride film 20d formed on the other side thereof with no window having been formed thereon. The gas sensor in accordance with this invention enables control of the thickness of the supporting film precisely since the supporting film 20 having the silicon nitride film 20a and the glass film 20b can not be etched due to the silicon nitride film 20a serving as an etch stop layer while carrying out an anisotropic etching of the silicon substrate 60 in the following process, and can sense a particular gas well since the sensing film 50 can be heated to a specific temperature due to the glass film 20b having a low heat conductivity that prevents loss of heat through the supporting film 20 at the time of heating the sensing film 50 to a high temperature. Moreover, the thickness of the supporting film 20 can be reduced because a conventional supporting film 20 uses three layers, a silicon oxide film 2a, a silicon nitride film 2b and a silicon oxide film 2c, whereas the supporting film of this invention uses two layers, a silicon nitride film 20a and a glass film 20b. As for the heaters 30b and the temperature sensors 30a, multiple metal layers are used. Platinum, being a high temperature material, has an excellent heat generation characteristic and exhibits an excellent agreement with the resistance law based on temperature, and tantalum is used to enhance the adhesive force between the platinum and the glass film. The heater 30b is provided for heating the sensing film 50 to a specific temperature to enhance the sensitivity of the sensing film 50 for a particular gas, and the temperature sensor 30a is provided to sense the temperature of the heater 30a. A nitride film is used as an interlayer insulation film 40, which silicon nitride film helps the sensing film 50 be heated to a specific temperature to sense a particular gas well because the silicon nitride film having an excellent insulation property and a high heat conductivity permits good transfer of the heat generated in the heater 30b to the sensing film. As for the sensing film electrode 50a, multiple layers of metal films such as Pt/Ta are used, and as for the sensing film 50, SnO2 doped with 1 wt % of palladium is used. The sensing film electrode 50a is provided for measuring the resistance component of the sensing film 50, and the sensing film 50 is provided for sensing a particular gas. The nitride film 20d formed at the back of the silicon substrate 60 serves as a masking material while carrying out an anisotropic etching of the silicon substrate 60. The characteristics of the thin film gas sensor fabricated through the foregoing processes obtained through tests are shown in FIGS. 5 to 8. FIG. 5 is a graph showing both the power consumption of a heater required to heat a sensing film and the resistance of sensors at the heated temperature. Referring to FIG. 5, it can be known that, with this invention, the power consumption of the heaters for heating the sensing film 50 to 300 deg. C., is 70 mW, 202 mW/mm2 for the heat generation part having an area of 0.588×0.588 mm2, is much lower than the power consumption, being 340 mW/mm2 for the heat generation part of a conventional sensor. In conclusion, by controlling the properties of the supporting film 20 such as the heat conductivity (σ), the thickness (h) and the ratio of the length to the heat generation part (u/a), it is possible to reduce the power consumption of the heater. Characteristics shown as graph in FIG. 6 could have been obtained as the result of measurements of the sensitivity based on the density of CH3 SH gas while changing the temperature of the sensing film 50 with the heater 30b formed in the sensing element. Referring to FIG. 6, the sensitivity of the sensing film 50 to a gas can be expressed as Ra (resistance of the sensing film in air)/Rg (resistance of the sensing film at exposure to a gas), it can be known that the sensor according to this invention can exihibit a sufficient sensitivity to CH3 SH gas when heated to a temperature over 250 deg. C. Shown in FIG. 7 is a response characteristic of a sensor to CH3 SH gas, wherein it can be shown that the speed of response is about 5 seconds and the recovery characteristic is excellent when the sensor is exposed to CH3 SH gas in a density of 0.2 ppm at 250 deg. C. Shown in FIG. 8 is result of tests for checking the sensitivity of the sensing film 50 of the thin film gas sensor in accordance with this invention to various gases. Referring to FIG. 8, it can be seen that sensitivities to CO, (CH3)3 N and C2 H5 OH are relatively lower than the sensitivity to CH3 SH. By this, it can be known that the sensor in accordance with this invention has an excellent selectivity to CH3 SH gas. As has been explained, a thin film gas sensor in accordance with this invention has the advantages of reducing the power consumption of the heater and the capability of forming the thin supporting film precisely as the result of forming the supporting film using glass having a heat conductivity lower than the materials at use presently, and forming an etch stop film using a silicon nitride film. Although the invention has been described in conjunction with specific embodiments, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, the invention is intended to embrace all of the alternatives and variations that fall within the spirits and scope of the appended claims. What is claimed is: 1. A low power consumption type thin film gas sensor comprising:a silicon substrate having a window in the central part of one side thereof: masking material formed on the one side thereof except the window; a supporting film formed of an etch stop layer and a glass film on the other side of the substrate; heaters and temperature sensors arranged in parallel on the supporting film facing the window, said heaters and temperature sensors having a fixed length of heat generation part; an interlayer insulation film formed on the supporting film to cover the heaters and the temperature sensors, sensing film electrodes formed on the interlayer insulation film; and, a sensing film formed on the interlayer insulation film so as to cover the sensing film electrodes for sensing a particular gas. 2. The thin film gas sensor as claimed in claim 1, wherein a silicon nitride film is used for the masking material. 3. The thin film gas sensor as claimed in claim 2, wherein the thickness of the silicon nitride film is 500 Angstroms to 2500 Angstroms. 4. The thin film gas sensor as claimed in claim 1, wherein a silicon nitride film is used for the etch stop layer of the supporting film. 5. The thin film gas sensor as claimed in claim 4, wherein the thickness of the silicon nitride film is 500 Angstroms to 2500 Angstroms. 6. The thin film gas sensor as claimed in claim 1, wherein one of PSG (phosphosilicate glass), BSG (borosilicate glass) or BPSG (borophosphosilicate glass) film is used for the glass film. 7. The thin film gas sensor as claimed in claim 6, wherein the thickness of the glass film is 5000 Angrtroms to 3 um. 8. The thin film gas sensor as claimed in claim 1, wherein the heaters and the temperature sensors are formed of multiple metal layers. 9. The thin film gas sensor as claimed in claim 8, wherein the heaters and the temperature sensors are formed of multiple metal layers of Pt/Ta. 10. The thin film gas sensor as claimed in claim 9, wherein the thickness of the heaters and temperature sensors are 5000 Angstroms to 3 μm. 11. The thin film gas sensor as claimed in claim 9, wherein the tantalum layer serves for enhancing the adhesive force between the platinum layer and the glass film of the supporting film. 12. The thin film gas sensor as claimed in claim 11, wherein the thickness of the tantalum layer is 200-700 Angstroms. 13. The thin film gas sensor as claimed in claim 1, wherein the length of the heat generation part of the heaters and the temperature sensors is less than 1/2 of the width of the supporting film. 14. The thin film gas sensor as claimed in claim 1, wherein a silicon nitride film is used for the interlayer insulation film. 15. The thin film gas sensor as claimed in claim 1, wherein multiple metal layers of Pt/Ta are used for the sensing film electrodes. 16. The thin film gas sensor as claimed in claim 1, wherein the sensing film is of SnO2 doped with 1 wt % of palladium. 17. The thin film gas sensor as claimed in claim 16, wherein the thickness of the sensing film is 1000 Angstroms to Angstroms.

1994-08-29

en

1996-08-13

US-19004594-A

Use of persistent heterocyclic free-radicals in magnetic resonance imaging ABSTRACT The present invention provides the use of a persistent π-system free radical for the manufacture of a contrast medium for use in magnetic resonance imaging, wherein the electron delocalising π-system of said radical comprises at least one homo or heterocyclic ring, said radical being other than the chloranil semiquinone anion radical or a trityl radical. Also provided are magnetic resonance imaging contrast media containing and methods using such radicals. The application is a 371 of PCT/EP92/01793 filed Aug. 6, 1992. The present invention relates to the use of persistent free radicals, in particular persistent free radicals having a carbon-based π-bonded electronic system available for delocalization of the unpaired electrons (hereinafter "persistent π-system radicals"), as image enhancing agents in magnetic resonance imaging (MRI) as well as to contrast media containing such radicals and to the use of such radicals and their non-radical precursors in the manufacture of MRI contrast media. MRI is a diagnostic technique that has become particularly attractive to physicians as it is non-invasive and does not involve exposing the patient under study to potentially harmful radiation, such as for example the X-radiation of conventional radiography. This technique, however suffers from several serious drawbacks, including in particular the expense of manufacture and operation of the MRI apparatus, the relatively long scanning time require to produce an image of acceptable spatial resolution, and the problem of achieving contrast in the magnetic resonance (MR) images between tissue types having the same or closely similar imaging parameters, for example in order to cause a tissue abnormality to show up clearly in the images. The expense of manufacture and operation of an MRI apparatus is closely associated with the strength of the magnetic field that the primary magnet in the apparatus is required to generate in order to produce images of acceptable spatial resolution in an acceptable time. MR images are generated by manipulation of the MR signals detected from the example, for example a human or animal body, placed in a magnetic field and exposed to pulses of radiation of a frequency (typically radiofrequency (RF)) selected to excite MR transitions in selected non-zero spin nuclei (the "imaging nuclei", which are generally water protons in body fluids) in the sample. The amplitude of the induced MR signals is dependent upon various factors such as the strength of the magnetic field experienced by the sample, the temperature of the sample, the density of the imaging nuclei within the sample, the isotopic nature and chemical environment of the imaging nuclei and the local inhomogeneities in magnetic field experienced by the imaging nuclei. Thus many techniques have been proposed for enhancing MR image quality, for example by increasing MR signal amplitude or by increasing the difference in MR signal amplitude between different tissue types. The imaging parameters (nuclear density, T1 and T2) for tissues of interest may be altered and many proposals have been made for doing this by the administration of magnetically responsive materials into patients under study (see for example EP-A-71564 (Schering), EP-A-133674 (Schering) and WO-A-85/04330 (Jacobsen)). Where such materials, generally referred to as MRI contrast agents, are paramagnetic they produce significant reduction in the T1 of the water protons in the body zones into which they are administered or at which they congregate, and where the materials are ferromagnetic or superparamagnetic (for example as suggested by Jacobsen) they produce a significant reduction in the T2 of the water protons. In either case the result is enhanced (positive or negative) contrast in the MR images of such zones. The contrast enhancement achievable by such agents in conventional MRI is relatively limited and it is generally not such as to allow a reduction in the image acquisition period or in the field strength of the primary magnet. Utilisation of the spin transition coupling phenomenon known as dynamic nuclear polarisation or as the Overhauser effect to amplify the population difference between the ground and excited spin states of the imaging nuclei by the excitation of a coupled ESR transition in a paramagnetic species present in the sample being imaged has been described by Hafslund Nycomed Innovation AB in WO-A-88/10419. This new technique for generating a MR image of the sample, which is hereinafter termed electron spin resonance enhanced magnetic resonance imaging (ESREMRI) or Overhauser MRI (OMRI), involves exposing the sample to a first radiation of a frequency selected to excite nuclear spin transitions in selected nuclei in the sample (radiation which is generally of radiofrequency or thereabouts and thus for convenience. will be referred to hereinafter as RF radiation) and also exposing the sample to a second radiation of a frequency selected to excite electron spin transitions coupled to nuclear spin transitions for at least some of the selected nuclei (radiation which is generally of microwave frequency or thereabouts and thus for convenience is referred to hereinafter as MW or UHF radiation), the MR images being generated from the resulting amplified MR signals (free induction decay signals) emitted by the sample. The paramagnetic substance which possesses the ESR transition which couples with the NMR transition of the imaging nuclei may be naturally present within the imaging sample or more usually may be administered as an OMRI contrast agent. In WO-A-88/10419 various OMRI contrast agents were proposed, for the most part these being nitroxide stable free radicals, although the use of the chloranil semiquinone radical and of Fremy's salt was also proposed. In WO-A-90/00904 Hafslund Nycomed Innovation AB proposed the use of deuterated stable free radicals, in particular deuterated nitroxide stable free radicals, as OMRI contrast agents. Organic free radicals however frequently have properties which render them unsuitable for use as OMRI contrast agents. Thus free radicals commonly are unstable in physiological conditions, or have very short half-lives leading to toxicity problems. A further drawback is the low relaxivity exhibited by many free radicals, which results in poor coupling of the electron and nuclear spin transitions and thus a poor enhancement of the magnetic resonance signal. A need therefore exists for improved free radical OMRI contrast agents and in WO-A-91/12024 Hafslund Nycomed Innovation AB proposed the use of carbon free radicals, and in particular various triarylmethyl radicals. The disclosure of WO-A-91/12024 is incorporated herein by reference. For such free radicals to be effective, they should be relatively long lived and to distinguish from free radicals which have a momentary existence, those usable as OMRI contrast agents will be referred to herein as being "persistent" free radicals, that is having a half life of at least one minute at ambient temperature. We have now found that other π-system radicals are useful as OMRI contrast agents and viewed from one aspect the present invention provides the use of a persistent π-system radical for the manufacture of a contrast medium for use in MRI, and especially for use in OMRI, wherein the electron delocalizing π-system of said radical comprises at least one homo or heterocyclic ring, said radical being other than the chloranil semiquinone anion radical, preferably other than perhalo radicals and especially preferably other than a triarylmethyl radical and particularly preferably said radical having an inherent linewidth for the peaks in its esr spectrum of less than 500 mG, especially less than 100 mG, and most especially no more than 50 mG. The cyclic π-system radicals-used according to the present invention thus involve as a basic structural component a structure which, in one mesomeric form, can be represented as X.sup.1 --(C═C).sub.n --X.sup.2 where X1 represents O.sup.•, S.sup.•, N.sup.• -, ##STR1## or, less favourably ##STR2## X2 represents an atom or group capable of participating in the π-bond system of the (C═C)n moiety, e.g. O-, S-, ##STR3## O-, etc; I N-, C═C is an unsaturatedly bonded carbon atom pair; n is a positive integer, i.e. having a value of at least I, preferably at least 2 and especially preferably up to 20, especially up to 10, e.g. 1, 2, 3, 4, 5 or 6; and where the atom chain X1 -(C═C)n -X2 contains or at least in part is a component of an unsaturated carbo- or heterocyclic ring, said ring preferably containing 5 to 8 members and optionally carrying one or more, preferably 1, 2 or 3, fused carbo- or heterocyclic rings also participating in the π-system. The π-system radicals used according to the present invention may contain more than one unpaired electron; although if this is the case the unpaired electrons should most preferably be involved in separate delocalizing π-systems, i.e. biradicals rather than triplet state radicals are preferred since the latter are generally less stable. Since it is generally preferred for OMRI contrast agents that their esr spectra should contain as few lines as possible, it is especially preferred that the number of non-zero spin nuclei in the proximity of high free electron density sites within the radical should be as low as possible. Accordingly proton (1 H) substitution of the atoms of the π-system atom chain should be minimized and while halogen atoms such as chlorines may (by virtue of their vacant d orbitals) participate in the π-system and so enhance radical stability their presence as substituents on or as X2 components of the π-system atom chain is generally to be avoided. From the foregoing, it will be appreciated that a single radical may include more than one π-system atom chain X1 -(C═C)n X2 and indeed it is generally preferred that this should be the case. It is however generally to be preferred that for a system where X1 is nitrogen the corresponding X2 should be other than nitrogen or that no more than one corresponding X2 be nitrogen. Otherwise however, and especially where X1 is oxygen or carbon, it may be desirable that X1 and X2 should be the same element and more particularly that the two atoms should be capable of equivalent electronic configurations in alternative mesomeric forms of the radical, as is for example the case with galvinoxyl radicals which offer two resonance structures with alternative equivalent sites for the -O.sup.• moieties. Examples of suitable central π-system skeletons for cyclic π-system radicals usable according to the invention thus include the following: Ar3 3 C.sup.• Ar2 2 C.sup.• -- Ar3 N+• Ar--N.sup.• -- ##STR4## Ar--O.sup.• Ar--S.sup.• Ar--C═C--O.sup.• ##STR5## where Ar represents an aryl group, e.g. a 5-8 membered carbo or heterocyclic group itself optionally carrying fused rings serving to extend the π-system. Where more than one Ar group is present they may be identical or different or even joined. Thus more explicit examples of cyclic π-system radical skeletons include ##STR6## (where "R" implies that a substituent, e.g. hydrogen, alkyl etc, is required). In the skeletal structures indicated above, -O.sup.• and -S.sup.• moieties late generally interchangeable and fused aryl rings may be added on if desired, subject of course to the general preference that the π-system should preferably contain no more than 4, especially no more than 3, fused rings. While radicals according to the invention may have charged X2 groups, such radicals will generally be less preferred. In order that the π-system radicals should perform most effectively as MRI contrast agents it will generally be preferred that the atoms of the X1 (C═C)n X2 chain and indeed of any conjugated ring systems be substituted. In this regard substitution is intended to fulfil a dual or treble function--to stabilize the radical and to reduce esr linewidths and/or reduce the number of lines in the esr spectrum. Of course for many structures or substitution sites one or more of these functions can be achieved by the same manner of substitution. Thus as mentioned above, substitution should generally be designed to minimize the occurrence of non-zero spin nuclei (especially hydrogen (1 H) at or even closely adjacent sites of high free electron density. Above and beyond this however substitution should generally be such as to block off or sterically hinder approach to atoms having high free electron density, so reducing radical reactivity and increasing stability, and also to provide electron withdrawing or electron donating substituents at sites where such effects serve to enhance stability. Generally speaking, electron donor or withdrawing substituents should preferably be selected to minimize esr line broadening or line splitting effects and sterically hindering or blocking groups should be selected to achieve their steric effect of hindering intermolecular approach with minimal deformation of the delocalizing π-system as such deformation reduces the radical stabilizing efficacy of the system. Although discussed further below, steric hindrance of neighbouring ring sites is preferably effected by substitution with t-butyl-thio, t-butoxy or t-butyl groups or by substitution of ortho and meta positions by bridging groups of formula -X7 -CR7 -X7 -, where each X7, which may be the same or different is O, S, C═O or SO2 (both X7 preferably being O or CO) and R7 is a hydrogen atom or a C1-6 alkyl group optionally substituted by hydroxyl, C1-6 alkoxy or carboxyl groups or amides, esters or salts thereof, e.g. a -O-C(CH3)2 -O- group. Among electron withdrawing groups for substitution of the radical skeleton, nitrile, sulphonate, sulphone, sulphonamide and salts thereof (e.g. R2 SO2, R2 OCOSO2 and R2 2 NCOSO2) and, more preferably, carboxyl groups (and esters, amides and salts thereof) are especially preferred. Within any one aryl ring however, generally only one or at most two such electron withdrawing groups will be desired. For electron donor groups, especially those at a para (or δ) position to a radical centre X1 group, groups of formula R2 O and R2 S are especially preferred where R2 is hydrogen or C1-6 alkyl optionally substituted by hydroxyl, or C1-6 alkoxy, amine, C1-6 alkyl or dialkyl amine, carboxyl (and amides and esters thereof) etc. Although many persistent cyclic π-system radicals are known, those having -X7 -CR7 2 -X7 - steric hindrance groups substituted on neighbouring carbon atoms of the ring systems and those having SO2 R3 (where R3 is R2, CO2 R2 or CONR2 2) solubilizing and/or stabilizing groups are novel and particularly suited for use according to the invention and thus form a further aspect of the invention. Viewed from a still further aspect, the invention also provides a method of magnetic resonance investigation of a sample, said method comprising introducing into said sample a persistent cyclic π-system radical as discussed above, exposing said sample to a first radiation of a frequency selected to excite electron spin transitions in said free radical, exposing said sample to a second radiation of a frequency selected to excite nuclear spin transitions in selected nuclei in said sample, detecting free induction decay signals from said sample, and, optionally, generating an image or dynamic flow data from said detected signals. Viewed from another aspect, the invention also provides a magnetic resonance imaging contrast medium comprising a physiologically tolerable persistent cyclic π-system free radical together with at least one pharmacologically acceptable carrier or excipient. For in vivo imaging, the free radical should of course preferably be a physiologically tolerable radical, or one presented in a physiologically tolerable, e.g. encapsulated, form. Preferred free radicals for use according to the invention exhibit high stability to oxygen, to pH, for example in the range pH 5-9, and in aqueous solution, particularly stability up to a concentration of 300 mM. Further desirable characteristics include reduced tendency to dimerization, long half-life, preferably greater than 1 minute, particularly preferably greater than 1 hour and especially preferably 1 year, long relaxation times, both T1e and T2e preferably being greater than 1 μsec, high relaxivity, for example greater than 0.3 mM-1 sec-1 and a small number of esr transition lines. As indicated above, the possibility exists to optimize different characteristics, e.g. solubility, stability and line broadening, of the overall radical by appropriate combinations of different substituents on the radical skeleton. Combinations, where one or more substituent is selected to optimize stability and line broadening, and one or more substituent is selected to optimize solubility are considered particularly interesting. In order to optimize the above-mentioned desirable properties, a number of criteria need to be borne in mind in selecting or constructing radicals for use according to the invention. Thus, the aromatic rings of the radicals advantageously are substituted and the nuclear identities of nuclei in all substituents and their positions within the molecule should be selected so as to minimise their effect (line splitting or broadening) on the esr transitions. In general, in a X1 (C1 ═C2)n X2 structure, it is especially desirable that the C2 carbons should be substituted, particularly any C2 carbon in a position δ to an X1 moiety. Substitution of C2 carbons is desirable in order to minimise dimerisation and oxygen attack on the molecule. C2 carbons in the β position relative to any X1 moiety are preferably by bulky substituents to minimise attack by oxygen and substitution of δ C2 carbons by electron withdrawing and/or water solubilizing groups is also particularly preferred. Such substituents preferably have no magnetic moment, or have a very low effective spin density. Alternatively, in order to minimise their effect on the esr transition, the substituents should be bonded in such a manner that they are capable of free rotation. In the radicals used according to the invention, the carbons of the π-system, e.g. carbons in unsaturated chains or rings, preferably carry substituents other than protons (1H) and indeed it is preferred that only one such carbon at most is unsubstituted. Suitable substituents include groups R1 which may be the same or different, and independently represent alkyl groups or groups of formula -M, -X3 M, -X3 Ar2 where M represents a water solubilizing group, each group X3, which may be the same or different, represents an oxygen or sulphur atom or a NH, CH2, CO or SO2 group; Ar2 represents a 5 to 10 membered aromatic ring optionally substituted by a solubilizing group M; or R1 groups on different or adjacent R1 groups (preferably groups at the α and β positions to an X1, moiety) together with the two intervening carbon atoms may represent groups of formula ##STR7## where R.sup. 6 represents a hydrogen atom, a hydroxyl group, an optionally alkoxylated, optionally hydroxylated acyloxy or alkyl group or a solubilising group M; Z represents an oxygen or sulphur atom or a group NR5, CR7 2, SiR7 2 ; R5 represents a hydrogen atom or an optionally hydroxylated, optionally aminated, optionally alkoxylated, optionally carboxylated alkyl, oxo-alkyl, alkenyl or alkaryl group; each R7, which may be the same or different, represents a hydrogen atom, an alkyl, hydroxyalkyl, alkoxycarbonyi or carbamoyl group or two groups R7 together with the atom to which they are bound represent a carbonyl group or a 5 to 8 membered cycloalkylidene, mono- or di-oxacycloalkylidene, mono- or di-azacycloalkylidene or mono- or di-thiacycloalkylidene group optionally with the ring attachment carbon replaced by a silicon atom (preferably however in any spiro structure the ring linking atom will be bonded to no more than three heteroatoms) and R7 where it is other than hydrogen, is optionally substituted by a group R6. Certain of the radicals substituted in this fashion are new and they, their salts and their non-radical precursors (e.g. compounds having a structural unit X4 X1 (C═C)n X2 where X4 is a leaving group, e.g. hydrogen, hydroxyl, halogen, carboxyl, CO2 OCO.C(Ar)3 or NNC(Ar)3) form further aspects of the present invention. In the radicals used according to the invention the solubilizing groups M may be any of the solubilizing groups conventionally used in diagnostic and pharmaceutical products. Particularly preferred solubilizing groups M include optionally hydroxylated, optionally alkoxylated alkyl or oxo-alkyl groups and groups of formulae R5, COOR5, OCOR5, CHO, CN, CH2 S(O)R5, CONR5 2, NR5 COR5, NR5 2, SO2 NR5 2 OR5, PO3 2-, SOR5, SO2 R5, SO3 M1, COOM1 (where M1 is one equivalent of a physiologically tolerable cation, for example an alkali or alkaline earth metal cation, an ammonium ion or an organic amine cation, for example a meglumine ion) --(O(CH2)p)m OR5 (where p is an integer having a value of from 1 to 3 and m is an integer having a value of from 1 to 5), --CX3 (CHR5)p X3 or (where R8 is a hydrophilic R.sup. 5 group) or SR10 or SO2 R10 where R10 is a group R5 or an alkyl group optionally substituted by one or more, especially two or three groups COOR5, OCOR5, CHO, CN, CONR5 2, NR5 COR5, NR5 2 SO2 NR5 2, OR5, PO3 2-, SOR5, SO2 R5, SO3 M1, COOM1, or --(O(CH2)n)m OR5. Especially preferred as solubilizing groups M are groups or formula C(H)3-p (CH2OH)p, R9, COR9, SR9, SOR9, SO2 R9 CON(R9)2, NR9 2, NHR9 and CONHR9 [where R9 may represent a C1-5 alkyl group optionally substituted by hydroxyl, alkoxy or amino groups or carboxyl groups or esters or amides thereof, e.g. groups ##STR8## (although any R9 group attached to a sulphur, nitrogen or oxygen atom is preferably not hydroxylated at the α carbon)], and groups of formula SR12 where R12 is a group CH2 COOR13, CH(COOR13)2, CH2 CONHR9, CH2 CONR9 2, CR5 (COOR13)2, CH(CN)CO2 R13, (CH2)p SO3 - M1, (CH2)p COR9, CH(COR9)CH2 COR9 and CH(R5)COR9 where p, M1 and R5 are as earlier defined and R13 is a hydrogen atom, an alkyl group or a group. M1 or R9. Further especially preferred solubilising groups M or X3 M include groups of formula X5 C((CH2)p COOR13)2 R14, X5 C((CH2)p COOR13)3 and X5 C((CH2)p COOR13)R14 2, where R13 is as defined above, p is an integer from 1 to .3, X5 is an oxygen or sulphur atom, and R14 is a hydroxyalkyl group such as a group R9 as earlier defined. Other examples of preferred R1 groups include for example the following structures --S--(CH2 CH2 O)p, R19 where p' is 0, 1 or 2 and R19 is hydrogen or C1-4 alkyl --S--(CH2)p, --CO--R23 where R23 is C1-4 alkyl (e.g. methyl, ethyl or t-butyl), NR2 21 or OR21 and R21 is C1-4 alkyl --COR22 where R22 is hydrogen, hydroxyl, R23, or COOR21 --CH2 O[CH2 CH2 O]p,CH3 --CH2 OCOR21 and ##STR9## where X3 is oxygen or sulphur. Where M represents a group containing a moiety NR5 2, this may also represent an optionally substituted nitrogen-attached 5 to 7 membered heterocyclic ring optionally containing at least one further ring heteroatom, e.g. N or O, for example a group of formula ##STR10## In the substituents on the radicals used according to the invention, any alkyl or alkenyl moiety conveniently will contain up to 6, especially up to 4, carbon atoms and any aryl moiety will preferably contain 5 to 7 ring atoms in the or any aromatic ring and especially preferably will comprise an aromatic ring with 0, 1 or 2 further aromatic rings fused directly or indirectly thereto. Preferred structures for the radicals include those in which at least one pair of adjacent ring carbons of the (C═C)n moiety or of any aryl substituent carries a fused ring of formula ##STR11## where X3 and Z are as defined before, especially rings of formulae ##STR12## where X3 is oxygen, sulphur, carbonyl or SO2 and R7 is hydrogen or optionally hydroxylated methyl. As has been discussed above, the substituents on the skeleton of the π-system serve primarily to achieve one or more of the functions of i) steric hindrance (blocking), ii) electron withdrawing (from the π-system), iii) electron donating (into the π-system) and. iv) enhancing the water solubility of the overall radical. The preferred electron donating blocking groups are t-butoxy, t-butylthio, NR70 2 (where R70 is as described below) and the --X7 --CR7 --X7 -- (where X7 is 0 or S) bridging groups. The preferred electron withdrawing blocking groups include --X7 --CR7 --X7 -- (where at least one X7 is SO or SO2) bridging groups CHO CONR70 2, COOR70, OCOR70, SO2 NR7 2, SO2 CR70 3, NR70 COR70, NR70 COOR70, OCONR70 2, NR70 SO2 R70, NR70 CONR70 2, NR70 SO2 NR70 2, COCR70 3, COCOR70, SO2 R70, COCOOR70, CN, COSR70, SOCR70 3 and CR70 ═NOR70 where R70 is hydrogen or alkyl or cycloalkyl (preferably C1-4 alkyl or C5-6 cycloalkyl) optionally substituted by one or more groups selected from OH, NH2, CONR71 2 and COOR71 (preferably 1, 2 or 3 hydroxy groups) and R71 is hydrogen or optionally hydroxylated C1-3 alkyl. Preferably R70 is C1-4 hydroxyalkyl ( e.g. CH2 OH, CH2 CH2 OH, CH2 CH2 CHOHCH2 OH, CH2 CHOHCHOHCH2 OH, CHaCHOHCH2 OH, and C(CH2 OH)3) or 2,3-dihydroxycyclopentyI or 2,3-dihydroxycyclohexyl. Thus taking for illustrative purposes the Ar3 C.sup.• and Ar-O.sup.• systems, preferred radical substitution for Ar3 C.sup.• is as described in PCT/EP91/00285 and examples of preferred substitution for Ar-O structures, such as for example the phenoxy, indolizinyl, indolyl, semiquinone and galvinoxyl structures, include those disclosed below: ##STR13## where each R32 which may be the same or different represents a hydrogen atom, a group R31 or a solubilizing group, e.g. a group M; R33 represents a group M20 or, less preferably, R31 ; each R31, which may be the same or different, represents a steric hindrance group, e.g. t-butyl or more preferably a -O-t-butyI or -S-t-butyl group, or two groups R31 on adjacent carbons together represent a steric hindrance bridging group e.g. a group -X7 -CR7 2 -X7 -, or X7 -NR5 -X7 - it being particularly convenient that both sets of R31 and R32 groups represent such bridging groups; M20 represents an electron donor group, e.g. a group OR9, SR9 (where R9 is preferably methyl), -CR36 ═CR34 R35 (where R34 and R35 are hydrogen, cyano, alkyl, aryl, or carboxyl or an amide or ester thereof and R36 is hydrogen or alkyl), or -CR36 ═N-R37 (where R37 is alkyl), preferably a group capable of lying in the plane of the phenyl ring. Examples of suitable steric hindrance R31 groups include Ar-O-, Ar-S-, At-SO2 -, Ar-CO-, alkyl-CO-, and other carbon or nitrogen attached homo or heterocyclic rings (preferably 5-7 membered, especially 5-membered and particularly preferably dithiacyclopentanes and derivatives thereof), e.g. ##STR14## Thus exemplary phenoxy structures include the following ##STR15## where R52 is an electron withdrawing group (e.g. a cyano or carboxyl group or an amide or ester thereof, e.g. a group COOR54 or CONR2 54 where R54 is hydrogen or optionally hydroxylated, alkoxylated or aminated alkyl) or, less preferably, a steric hindrance or solubilizing group, e.g. R31 or M; each of R48, R49, R50, R51 and R53 is a hydrogen or a steric hindrance or solubilizing group (e.g. R31 or M), R50 preferably being hydrogen and the remaining preferably being other than hydrogen, especially R48 and R49 which particularly preferably represent steric hindrance groups such as -S-tBu, -O-tBu etc. In a preferred embodiment each of the groups R50, R51 and R53 which may be the same or different independently represents a hydrogen atom, a hydroxy group or an optionally hydroxylated optionally alkoxylated alkyl, alkoxy, alkylthio or acyloxy group or a water solubilising group M; R52 represents an electron withdrawing group, a sulphone or sulphonamide group (e.g. SO2 R54, SO2 NR2 54) or a group as defined for R50 with the exception of hydrogen; each of the groups R48 and R49 independently represents a hydrogen atom, a water solubilising group M or an alkyl, alkoxy, alkylthio, acyloxy or aryl group optionally substituted by alkyl, hydroxy, mercapto, alkoxy or optionally alkoxylated, optionally hydroxylated acyloxy groups, or by a water solubilising group M; or adjacent groups R48 and R49, R50 and R51, R51 and R52 and/or R52 and R53, together with the two intervening carbon atoms may represent groups of formula ##STR16## where R7 represents a hydrogen atom, a hydroxy, or optionally hydroxylated, optionally alkoxylated acyloxy group or a water solubilising group M. Preferred indolizinyl radicals include those wherein R52 is an electron withdrawing group, especially an ester or amide or a carboxy group or a salt thereof. Preferably also R48 and R49 are identical, and particularly preferably R48 and R49 are both solubilizing groups M or optionally substituted alkoxy or alkylthio groups. More preferably R52 and one of R50, R51 and R53 are alkoxy groups or a group -COO54, -OCOR54, -CONH54 or -CONR54 2, e.g. -CON(CH2 CH2 OH)2. Examples of particularly preferred identities for R48 to R53 are as follows: for R53 : hydrogen, methoxy and carboxy and salts, esters and amides thereof for R52 : cyano, carboxy and salts, esters and amides thereof for R51 : hydrogen, methoxy and carboxy and salts, esters and amides thereof for R50 : hydrogen, methoxy, tri(hydroxymethyl)methylthio and carboxy and salts, esters and amides thereof for R50 and R51 together: dimethyl methylenedioxy and di(hydroxymethyl)methylenedioxy for R48 and R49 : phenyl, t-butoxy, t-butylthio, carboxymethylthio, 3,4-dihydroxybutanoyloxy, 2,3-dihydroxypropoxycarbonyl, 2-sulphoethylthio, tri(hydroxymethyi)methyl, bis 2-hydroxyethyl carbamoyl and his (2,3-dihydroxypropyl)carbamoyl. for R48 and R49 together: dimethylmethylenedioxy and di(hydroxymethyl)methylenedioxy. Particularly preferred indolizinyl radicals for use in accordance with the invention include ##STR17## More preferred indolizinyl radicals include: ##STR18## as well as radicals of the general formulae ##STR19## Indolizinyl radicals wherein R53 and R52 are carboxy groups and R50 and R51 together are dimethylmethylenedioxy or di(hydroxymehtyl)methylenedioxy groups or where R53 and R51 are methoxy groups, R52 is a carboxy group and R50 is a trihydroxymehtyl methylthio group are also preferred. Examples of indolizinyl radicals include ##STR20## Most of the persistent indolizinyl radicals discussed above are themselves novel and they, their salts, and their non-radical precursors form further aspects of the invention- In particular the water-soluble compounds are all novel. In particular the novel indolizinyl radicals include compounds wherein R48 to R53 are as hereinbefore defined with the proviso that where either one of R53, R52 or R51 is cyano, or R52 is -CHO, -CO2 CH3, -CONH2, or -COOH3, and the remaining substituents R50, R51, R52, R53 are hydrogen, at least one of R48 and R49 is other than a substituted or unsubstituted phenyl group, and that where R52 is cyano, and R50, R51, and R53 are hydrogen, at least one of R48 and R49 is other than n-C3 H7. ##STR21## where R65 to R68 are hydrogen or more preferably steric hindrance, solubilizer or electron-withdrawing groups, e.g. R31 or M; R63 is a steric hindrance, solubilizer or a π-system extending group, e g R31, M carboxyl or an indolyl group (as with the dibenzoyl indigo structure); and R64 is an acyl, e.g. PhCO, group or an alkyl group optionally substituted by solubilizing moieties, e.g. hydroxyl, amine, alkoxy, carboxy and sulphourea groups, for example by -CON (CH2 CH2 OH)2 or -SO2 N (CH2 CHOHCH2 OH)2 groups. Thus R65 to R68 conveniently may represent bridging moieties of the type discussed above, e.g. -O-C(CH3)2 -O- groups or t-butoxy or t-butylthio groups or one or two of R66, R67 and R68 may conveniently represent SO3 - groups. Examples of appropriate indolyl radicals include: ##STR22## where R═CH2 CHOHCH2 OH or CH(CHOHCH2 OH)2 ##STR23## where R69 to R72 which may be the same or different represent steric hindrance and/or solubilizing groups or more preferably R69 and R70 and/or R71 and R72, together with the intervening carbons form fused aryl rings, preferably 5-7 membered rings, which optionally but preferably themselves carry steric hindrance and/or solubilizing (e.g.. R31 and M) groups. Particularly preferably, the mesomeric forms of the semiquinone anion radicals, i.e. O-B-O- and O-B-O (where B is used to represent the body of the molecule) are identical. Examples of semiquinone anion radicals thus include ##STR24## where X6 is N, CH or ##STR25## each of R79, R78, R80 and R81 is a steric hindrance group (especially t-Butyl), optionally carrying a solubilizing moiety and each of R76, R77, R79 and R82 is hydrogen or a steric hindrance or solubilizing group or adjacent pairs of R75 to R82 may together represent bridging steric hindrance groups or fused aryl rings (optionally themselves carrying steric hindrance and/or solubilizing groups). As examples of enolate radicals may be mentioned: ##STR26## Such radicals are described in the literature, for example by O'Neill and Hagarty in J. Chem. Soc., Chem. Commun. 198.7, 744 and J. Org. Chem. 52, 2115, 1987. Generally speaking, substitution to enhance radical stability should be at or adjacent sites in the X1 C═C)n X2 π-system which have high spin density. Substitution at high spin density sites should generally be with unreactive groups and frequently electron withdrawing or electron donor substituents will be preferred. Substitution at neighbouring sites should generally be by bulky steric hindrance groups which serve to prevent the radical from reacting with other molecules or radicals. The steric hindrance groups can also serve to enhance water solubility of the radical; alternatively separate solubilizing substituents may be included. The particularly preferred substituent groups for the radicals for use according to the invention include the following -tBu, -O-tBu, -S-tBu, -OC (CH3)2 -O-, I, -CO- CR7 2 -CO-, -CO-NR5 -CO-, -SO3 Na, -COOR2, -S-R2, -SO2 R2, SO2 NR2 2. Persistent cyclic π-system radicals are widely known from the literature and ones suitable for use according to the invention may be prepared by the methods described in the literature. Substitution along the lines discussed above may be achieved using methods known from the literature or by using methods analogous to those discussed in PCT/EP91/00285. Examples of relevant literature references include Forrester et al "Organic chemistry of stable free radicals" Academic Press, London1968, Tetrahedron 18:61 (19..), Berichte (1957) page 1634, Angew Chem. Int. (1984) page 447, Helvetica (1988) page 1665, JACS (1957) page 4439, Rosenblatt JACS 62:1092 (1940), Taube et al. Berichte 86:1036 (1953), Weygand et al. Berichte 90:1879 (1957), Dann et al. Berichte 93:2829 (1960), Sziki Berichte 62:1373 (1929), Moore J Org Chem 33:4019 (1968), Fieser et al. JACS 70:3165 (1948), Reynolds et al. Org. Synthesis. 34:1 (19.54); Fujita Tet. Lett (1975) page 1695, Akita J Pharm Soc. Japan 82:91 (1962), Graebbe J. fur Praktische Chemie 62:32 (1900), Helferich et al. Annalen 551:.235 (1942), Indian J. Chem. 12:893 (1974), Ramirez et al. JACS 81:4338 (1959), Ramirez et al. JOC 23:778 (1958), Stock et al. JACS 86:1761 (1964), Ramirez et al. JOC 3.3:20 (1968), Methoden der Organischen Chemie --Houben Weyl page 464-5, No. VII/3a (1977), Can J Chem 40:1235 (1962), Chem Lett (1984) page 341, JCS Perkins II (1989) page 1349, JACS (1960) page 6208, J Chem Phys (1965) page 308, JOC (1988) page 5770, McNab et al. JCS Perkins II (1988) page 759, Russell et al. JACS (1970) page 2762, Weiser et al. Tet. Lett. 30:6161, J Phys Chem 71:68 (1967), Dimroth et al. Liebigs Annalen 624:51 (1959), Miura et al. JOC 58:5770 (1988), Ata et al. Chem Lett (1989.) 341-344, Solar JOC 28:2911 (1963), JOC 51:4639 (1986), JOC 54:3652(1989), Theophil Eioher and Josef L Weber "Structure and Reactivity of Cyclopropenones and Triafulvenes" in Topics in Current Chemistry vol 57, Springer Verlag pages 1-109, Comprehensive Heterocyclic Chemistry Vol 4 part 3 Pergamon 1984 London, ISBN 0-08-030704-3, Chapter 3/08 Pyrroles with Fused Six-membered Heterocyclic Rings:(i) a-Fused, Pages 443-495; W Flitsch Methods for the construction of the Indolizine Nucleus; Takane Uchida, Synthesis pages 209-236; Moria L Bode and Perry T Kaye: A New Synthesis of Indolizines via Thermal Cyclisation of 2-Pyridyl derivatives. JCS PERKIN TRANS I (1990) 2612-2613; K Matsumoto and T Uchida Synthesis (1978) 207-208; Esko Pohjala. Acta Chem Scand. B 28 (1974) p582-583, B 29 (1975) 1079-1084, B 30 (1976) 198-202, B 31 (1977) 321-324; Heterocycles (1974). 585-588; Heterocycles (1975) 615-618; J Heterocyclic Chem (1977) 273-279; J Heterocyclic Chem (1978) 955-960; D H Wadsworth et al J. Org Chem (1989) 3660-3664; Tet Lett. (1981) 3569-3572; J. Org Chem (1986) 4639-4644; J Org Chem (1989) 3652-366.0; L Cardellini et al. JCS PERKIN TRANS II (1990) 2177-2121; Tominaga et al. Heterocycles J Her Chem (1989) page 477; JACS (1990) p 8100; Tet. Lett. (1990) pp. 56.8.9, 7109 and 6949; JCS Perkin I (1990) p. 2612; J Het. Chem (1990) p 263; JCS Perkin I (1989) p. 1547; Bordwell JACS 113:3495 (1991); Chem Ber 93:2649 (1960); Chem Ber 87:922 (1954); Acta Chem Scand. 23:751 (1969); Chem Ber 32:25139 (1909); Becker et al. New J Chem 12:875 (1988). Persistent free radicals which have relatively few transitions, e.g. less than 15, preferably less than 10, in their esr spectra and radicals having narrow linewidth esr transitions, e.g. up to 500 mG, preferably less than 150 mG, especially less than 60 mG and particularly less than 25 mG, are especially preferred for use as OMRI contrast agents. (The linewidths referred to are conveniently the intrinsic linewidths (full width at half maximum in the absorption spectrum) at ambient conditions). Whilst low numbers of esr transition lines are generally preferred to obtain more effective coupling of the esr and NMR transitions, we have found that. surprisingly good coupling, and therefore enhancement of the MR signal, may also be achieved with radicals showing a large number of ESR transitions. Where the radicals have a multiplicity of esr transitions, the hyperfine splitting constant is preferably very small. In this connection radicals having as few as possible non-zero spin nuclei, positioned as far away as possible from the paramagnetic centre are thus especially preferred. The novel radicals of the invention include radicals which surprisingly are stable at physiological pH, have long half lives (at least one minute, and preferably at least one hour), long relaxation times, and exhibit surprisingly good relaxivity. Water-soluble radicals are a particularly important aspect of the invention. The radicals may be coupled to further molecules for example to lipophilic moieties such as long chain fatty acids or to macromolecules, such as polymers, proteins, polysaccharides (e.g. dextrans), polypeptides and polyethyleneimines. The macromolecule may be a tissue-specific biomolecule such as an antibody or a backbone-polymer such as polylysine capable of carrying a number of independent radical groups which may itself be attached to a further macromolecule. Coupling lipophilic groups is particularly useful since it may enhance the relaxivity of the radicals in certain systems such as blood. Such lipophilic and macromolecular derivatives of the radicals and salts thereof form a further aspect of the present invention. The linkage of a radical to the further molecule may be effected by any of the conventional methods such as the carbodiimide method, the mixed anhydride procedure of Krejcarek et al. (see Biochemical and Biophysical Research Communications 77:581 (1977)), the cyclic anhydride method of Hnatowich et al. (see Science 220:613 (1983) and elsewhere), the backbone conjugation techniques of Meares et al. (see Anal. Blochem. 142:68 (1984) and elsewhere) and Schering (see EP-A-331616 for example) and by the use of linker molecules as described for example by Nycomed in WO-A-89/06979. In view of their surprisingly beneficial properties, the novel radicals of the invention may also be used as esr spin labels in esr imaging or in magnetometry. The radicals may be prepared from their non-radical precursor compounds by conventional radical generation methods for example comproportionation, oxidation, reduction or any of the other methods known from the literature or described in PCT/EP91/00285. Thus in a-further aspect the invention provides a process for the preparation of the novel radicals of the invention which comprises subjecting a radical precursor therefor to a radical generation step and optionally subsequently modifying the substitution on the aryl moieties, e.g. by oxidation or reduction. By such modification for example, sulphide substituents (e.g. --SCH3 or -SCH2 COOEt) may be oxidized to the corresponding sulphones so avoiding problems of acidic hydrogens prior to radical formulation. Similarly lipophilic substituents (such as -SCH2 COOEt) may be reduced to corresponding hydrophilic substituents (e.g. -SCH2 CH2 OH). Thus for example carbon free radicals may conveniently be prepared from corresponding triaryl methyl halides by reduction with a metal catalyst, such as copper, zinc or silver, or by electrolytic reaction on an electrode or by photochemical reaction in the presence of a chlorine radical scavenger, e.g. an olefin. Alternatively, carbon free radicals may be prepared from the corresponding triaryl methanes by reaction with a base, e.g. in the presence of sodium hydride followed by a reaction with an oxidant, e.g. iodine in the presence of oxygen or a quinone such as chloranil, following for example the method described in U.S. Pat. No. 3,347,941. Another method to prepare triarylmethyl radicals is to react triarylmethates with other, less stable radicals such as tert-butoxyl radicals. The latter radicals are generated in situ via thermolysis or photolysis of an appropriate precursor, such as a peroxide or an azo compound. A further example of a method by which radical preparation may be effected is reaction of the corresponding triaryl methanols in the presence of an acid to form a carbonium ion followed by reduction to the free radical in the presence of a suitable reducing agent, such as metal ions e.g. Cr2+, Fe2+, or by electrochemical reduction. The carbon free radicals may also be generated by a comproportionation reaction between cations and anions of a corresponding radical precursor. In such a reaction an electron is exchanged between the anion and the cation, and two radicals are generated. Triarylmethyl radicals may thus be prepared by mixing together a triarylmethyl radical precursor cation with a corresponding anion. Triarylmethyl radicals may also be prepared by thermolysis or photolysis of a corresponding dimeric triarylmethyl structure, for example an azobistriarylmethyl or a bis (triarylmethylcarboxylic acid) peroxide. An alternative method of preparation of triarylmethyl radicals is the electrochemical decarboxylation of a triarylmethylcarboxylate. While radicals with long half lives in aqueous solution, for example at least one hour, preferably ten days, more preferably fifty days and especially preferably at least one year are clearly particularly desirable for use in in vivo imaging, shorter lived inert free radicals may still be utilised in imaging (e.g. of inanimate samples) and these may particularly conveniently be prepared immediately pre-administration. The non-radical precursors may themselves be prepared by methods conventional in the art or analogous to those described in PCT/EP91/00285. Taking as another illustrative example the indolizinyl radicals, these indolizinyl radicals may be generated from the corresponding indolizinols by oxidation under air or oxygen, or by using a chemical oxidant such as benzoquinone, iodine or chloranil. Oxidation under air or oxygen is preferred. Oxidation may conveniently be effected during cyclization to form the indolizinyl skeleton, during work-up or even before or during administration. The non-radical indolizinyl precursors may themselves be prepared by methods conventional in the art. Thus to form an indolizinol, a suitable cyclopropenone is conveniently reacted with an appropriately substituted pyridine, following for example the procedures described by Wadsworth et al in Tetrahedron lett. 22:3569 (198.1) and J. Org. Chem 51:463.9. (1986). Further processes for the preparation of oxoindolizine and oxoindilizinium compounds, i.e. derivatives in the keto as opposed to enol form, which may be used as non-radical precursors are described in EP-A-68880 and U.S. Pat. No. 4,446,223. Thus indolizinyl free radicals according to the invention may be prepared by following reaction schemes such as those suggested below: ##STR27## For the preparation of the non-radical precursors for indolizinyl radicals for use according to the invention, the literature contains many further useful guidelines. Thus one suitable approach for the production of nitro substituted precursors is described by Tominaya et al in J Heterocyclic Chem (1989) p. 477 ##STR28## The nitro group can then be transformed into an oxygen radical, e.g. folowing the sequence: ##STR29## Hydrogenated indolizinyls, for instance indolizinyl alkaloids like castanospermine or similar substances also represent useful reagents in the synthesis of the indolizinyl radicals. These hydrogenated substances can be dehydrogenated and/or dehydrated to the indolizinols/indolizinyls. (See J.A.C.S. 1990, 8100; Tet Lett 1990, 5689; Tet Lett 1990, 7109; Tet Lett 1990, 6949). More specific routes to indolizinyl radicals include the following: ##STR30## The preparation of semiquinone anion radicals is widely described in the literature. However, by way of illustration, aryloxy and semiquinone radicals can be prepared from quinones/hydroquinones according to the following general schemes: ##STR31## If several products are formed, they can be separated by chromatography or crystallization, or by a combination of these techniques. ##STR32## This group of alkoxyphenoxyl radicals is thus clearly related to the semiquinone anion radicals, the only difference being the R* instead of the minus charge, i.e. ##STR33## Where a monoalkylated product is desired, in order to generate phenoxyl rather than semiquinone anion radicals, a quinone starting material should be reduced to the hydroquinone form before the alkylation is effected. Suitable reduction techniques are described for example by E F Rosenblatt JACS 62, 1940 p 1092; H J Taube et al. Berichte 86, 1953, p 1036; F W Weygand et al. Berichte 90, 1957, p 1879; O Daun et al. Berichte 93, 1960, p 2829; T Sziki, Berichte 62, 1929, p 1373; H W Moore, J. Org. Chem. 33, 1968, p 4019; L Feiser et al. JACS 70, 1948, p 3165; G A Reynolds et al., Organic Synthesis 54, 1954, p 1; T Akita, J. Pharm. Soc. Jpn. 82, 1962, p 91; S Fujita et al., Tet Lett, 1975, p 1965; and C Graebbe, Journal fur Praktische Chemie [2], 62, 1900, p 32. Moreover using sodium borohydride, a whole range of quinones may be reduced to semiquinone anion radicals and, with more than one equivalent of H.sup.•, further reduction to hydroquinones is observed. An example is given below. ##STR34## Other examples of quinone reductions useful for the preparation of radical precursors include ##STR35## (In these formulae the R groups will generally be identical to the specifically identified substituents at the 2- positions). General methods for alkylation of phenols/hydroquinones can be found in Compendium of Organic Synthetic Methods Vol. I-V by Harrison and Harrison and later by Hegedus and Wade, Wiley Interscience. Compounds of formula ##STR36## may be made either from diacylated hydroquinone by mild hydrolysis of one acyl group or by selective monoacylations. In general, phenoxy radical precursors of formulae ##STR37## (where M3 represents a group which makes the molecule water soluble) are desirable and may be made in this fashion, for example according to a scheme such as: ##STR38## Other phenol/quinone substitutions are described for example in: F Ramirez et al JACS 81, 1959, p 4338; F Ramirez et al JOC 23, 1958, p 778; G Stork et al JACS 86, 1964, p 1761; and F Ramirez et al JOC 33., 1968, p 20. In synthesising substituted radicals, the substituents may be introduced onto individual component substructures before they are put together to form the radical precursor compounds, or they may be introduced directly onto the precursor compound or the actual radical itself. It is also possible to effect the substitution and radical construction steps simultaneously in a "one-pot" reaction. For use in OMRI, the radicals are conveniently formulated into contrast media together with conventional pharmaceutical carriers or excipients. Contrast media manufactured or used according to this invention may contain, besides the radicals (or the non-radical precursor where radical formation is to be effected immediately before administration), formulation aids such as are conventional for therapeutic and diagnostic compositions in human or veterinary medicine. Thus the media may for example include solubilizing agents, emulsifiers, viscosity enhancers, buffers, etc. The media may be in forms suitable for parenteral (e.g. intravenous) or enteral (e.g. oral) application, for example for application directly into body cavities having external voidance ducts (such as the gastrointestinal tract, the bladder and the uterus), or for injection or infusion into the systemic vasculature. However, solutions, suspensions and dispersions in physiologically tolerable media will generally be preferred. Free radicals which are relatively unstable or insoluble in the sample environment may be encapsulated, e.g. in gastric juice resistant capsules containing a medium in which they are stable. Alternatively, the radicals may be presented as an encapsulated freeze dried powder in a soluble capsule. Such formulations might conveniently be dissolved shortly before in vivo use. For use in in vivo diagnostic imaging, the medium, which preferably will be substantially isotonic, may conveniently be administered at a concentration sufficient to yield a 1 micromolar to 10 mM concentration of the free radical in the imaging zone; however the precise concentration and dosage will of course depend upon a range of factors such as toxicity, the organ targetting ability of the contrast agent, and the administration route. The optimum concentration for the free radical represents a balance between various factors. In general, optimum concentrations would in most cases lie in the range 0.1 to 100 mM, especially 0.2 to 10 mM, more especially 0.5 to 5 mM. Compositions for intravenous administration would preferably contain the free radical in concentrations of 10 to 1000 mM especially 50 to 500 mM. For ionic materials, the concentration will particularly preferably be in the range 50 to 200 mM, especially 130 to 170 mM and for non-ionic materials 200 to 400 mM, especially 290 to 330 mM. For imaging of the urinary tract or the renal or biliary system however, compositions may perhaps be used having concentrations of for example 10 to 100 mM for ionic or 20 to 200 mM for non-ionic materials. Moreover for bolus injection the concentration may conveniently be 0.1 to 100 mM, preferably 5 to 25 mM, especially preferably 6 to 15 mM. The present invention will now be further illustrated by the following non-limiting Examples (percentages, parts and ratios are by weight and temperatures are in degrees Celsius unless otherwise stated). EXAMPLE 1 ##STR39## 2,3-Diphenyl-1-hydroxyindolizine-7-carboxylate triethylammonium salt Diphenylcyclopropenone (Aldrich 17,737-7) (0.5000 g 2.424 * 10-3 mole) and isonicotinic acid (Aldrich I-1,750-8) (0.2985 g 2.424 *, 10-3 mole) were added in solid form to a carefully dried reaction flask. The flask was equipped with a septum and the flask was evacuated three times with addition of nitrogen after each evacuation. Chlorobenzene (Aldrich 27,064-4) (5 ml) was added with a gastight syringe. The stirred mixture was cooled to 0° C. Triethylamine (Aldrich 23,962-3) (0.3379 ml, 2.42 * 10-1 mole) was added dropwise with a gastight syringe. The resulting mixture was stirred at ambient temperature for 2 days. The colour of the mixture changed to yellow and then to green. The solvent was removed on a rotavap, and the resulting semisolid was redissolved in hot ethanol and water. After cooling to ambient temperature, the product was filtered and washed with diethylether and dried in vacuum. All these operations were performed under an atmosphere of N2. Yield: 0.653g (1.517 * 10-3 mole)=62.6% of theory 1 H NMR (250 MHz) (DMSOd6 /D2 O with sodium hydrosulphite (Aldrich 15,795-3) present)) (water resonance at 4.60 ppm as reference) δ: 1.10 (t, 9H), 2.98 (q, 6H), 6.70 (d, 1H, H6, JH6-H5, 7.56 Hz), 7.1-7.2 (m) and 7.25-7.35 (m) (total 10 H, 2 Ph), 7.70 (d, 1H, H5, JH5-H6, 7.56 Hz), 8.04 (bs, 1H, HS). MS (DEI) (DCI probe and electron impact ionization) M/Z: 329 (10.%), 178 (8%), 86 (100%) EXAMPLE 2 ##STR40## 2,3-Diphenyl-1-hydroxyindolizine-6,7-dicarboxylate di-triethylammonium salt Diphenylcyclopropenone (0.5000 g, 2.424 * 10-3 mole) and pyridine-3,4-dicarboxylic acid (0.4051 g, 2.424 * 10-3 mole) were added to a carefully dried reaction flask. The flask was equipped with a septum and evacuated three times with addition of nitrogen after each evacuation. Methanol (10 ml) (degassed with N2) was added and the stirred slurry cooled to 0° C. Triethylamine (0.666 ml, 6.20 * 10-3 mole) was then added with a syringe. The reaction mixture was stirred for 3 days at ambient temperature. (Thin layer chromatography showed complete conversion after one day). The yellowish product was filtered (under nitrogen to prevent radical formation) and washed with diethyl ether and dried at high vacuum. 1 H NMR in D2 O/DMSOd6 showed only ethyl resonances, upon addition of sodium hydrosulphite the resonances from the heterocycle appeared. Yield: 0.762 g (1.3235 * 10-3 mole)=54.6% of theory 1 H NMR (250 MHz) (D2 O/DMSOd6, sodium hydrosulphite present) (water resonance at 4.60 ppm as reference) d: 3.12 (t, 18H), 4.99 (q, 12H)9.16-9.30 (m) and 9.34-9.46 (m) (total 10 H, 2 Ph), 10.42 (s, 1H, H5) and 10.59 (s, 1H, HS). MS (DEI) M/Z 373 (5%), 355 (47%), 329 (100%) EXAMPLE 3 ##STR41## 2,3-Diphenyl-1-hydroxyindolizine-6,7-dicarboxylate triethanolammonium salt Diphenylcyclopropenone (0.5000 g, 2.424 * 10-3 mole) and pyridine-3,4-dicarboxylic acid (0.405.1 g, 2.424 * 10-3 mole) were added to a carefully dried reaction flask. The flask was equipped with a septum and evacuated three times with addition of nitrogen after each evacuation. Methanol (10 ml) (degassed with N2) was added with a gastight syringe and the stirred suspension cooled to 0° C. Triethanolamine (0.3217 ml, 2.424 * 10-3 mole) was added dropwise with a gastight syringe. The mixture was stirred for 48 hours at ambient temperature, cooled to about +10° C. and the product was isolated by filtration under N2. The product was washed with a little cold methanol and ether on the filter and dried in vacuum. Yield 0.548 g (1.0487 * 10-3 mole)=43% of theory 1 HNMR (250 MHz) (DMSO d6 /D2 O with sodium hydrosulphite present) (water resonance at 4.60 ppm as reference) d: 3.36 (t, CH2, 6H), 3.82 (t, CH2, 6 H), 7.15-7.35 (m) and 7.40-7.50 (m) (total 10H, 2-Ph), 8.37 (s, 1H, H5) and 8.58 (s, 1H, H8). MS (DEI) M/Z: 373 (11%), 355 (48%), 329 (100%) MS (Thermospray after RP 18 column, MeOH:H2 O 3:10.2 M NH40 Ac) M/Z: 390 (M+18, 1%), 374 (M+1, 1%), 344 (17%), 330 (34%). EXAMPLE 4 ##STR42## 2,3-Diphenyl-1-hydroxyindolizine-7-carboxylate triethanolammonium salt Diphenylcyclopropenone (0.6249 g, 3.03 , 10-3 mole) and isonicotinic acid (0.2985 g, 2.424 * 10-3 mole) were added to a carefully dried reaction flask. The flask was equipped with a septum and the flask was evacuated three times with addition of nitrogen after each evacuation. Methanol (19 ml) was added with a gastight syringe. The stirred suspension (slightly yellowish) was cooled to 0° C. Triethanolamine (Aldrich T5,830-0) (0.3217 ml, 2.424 * 10-3 mole) was added dropwise with a gastight syringe. The suspension went into solution immediately and an orange colour appeared. The reaction mixture was stirred at ambient temperature for 2.5 hours, while the title compound precipitated. The mixture was cooled to about 0° C. and the product isolated by filtration under N2. The product was washed with minute amounts of methanol and some diethylether and dried. Yield: 0.246g (5.1.51 * 10-4 mole)=17% of theory The product was identified by mass spectrometry; DCI probe and electron impact conditions identified the heterocyclic part and 1 HNMR identified the ammonium part. The product was further characterized by ESR and OMRI, measurements of the corresponding radical which was generated by treatment with oxygen. MS (DEI) M/Z: 329 (97%), 178 (100%) EXAMPLE 5 ##STR43## 2,3-Diphenyl-1-hydroxyindolizine-7-carboxylate N-methylglucammonium salt Diphenylcyclopropenone (0.500 g, 2.424 * 10-3 mole), isonicotinic acid (0.2985 g, 2.424 * 10-3 mole) and N-methylglucamine (0473. g 2.424 * 10-3 mole) were added to a carefully dried reaction flask. The flask was equipped with a septum and was evacuated three times with addition of nitrogen after each evaporation. Tetrahydrofuran (10 ml, degassed with helium) was added with a gastight syringe. A yellow colour formation is observed immediately. The colour changed to black and all solids dissolved over a period of 18 hours. The product was precipitated by addition of petroleum ether (10 ml, 30°-60° C.--degassed with N2). The yellow/green (indolizinol/indolizinyl) product was filtered under N2 and washed with small amounts of tetrahydrofuran and petrol ether. More solids formed in the filtration flask and were also collected. The products were identified as the title compound based on mass spectrometry and ESR/OMRI measurements. Yield: 0.105 g (2.002 * 10-4 mole)=8.3% of theory MS (DEI) M/Z: 329 (100%), 178 (100%) EXAMPLE 6 ##STR44## 2,3-Diphenyl-1-hydroxyindolizin-6,7-dicarboxylate didipropan-2,3-diolammonium radical salt, In situ formation of the radical 3,4-Pyridinedicarboxylic acid (2.424 , 10-3 mole, 0.4051 g), diphenylcyclopropenone (2.424 , 10-3 mole, 0.5000 g) and di(propane-2,3-diol) amine (4.848 * 10-3 mole, 0.8008 g) were stirred in methanol (1.0 ml), under an atmosphere of air for 24 hours at ambient temperature. Thin layer chromatography revealed complete consumption of the cyclopropenone and the solvent was removed on high vacuum, yielding the product as a foam. The radical was identified by mass spectrometry (DCI-EI and thermospray) and by the ESR spectrum and the OMRI effect in a water solution (buffer pH 7.4). EXAMPLE 7 ##STR45## 2,3-Diphenyl-1-hydroxyindolizin-6,7-dicarboxylate di-N-methylglucammonium salt 3,4-Pyridinedicarboxylic acid (2,424 * 10-3 mole, 0.4051 g), diphenylcyclopropenone (2. 424 * 10-3 mole, 0.5000 g) and N-methylglucamine (4.848, 10-3 mole, 0.9404 g) were stirred in a mixture of tetrahydrofuran (10 ml, degassed with helium) and methanol (3 ml, degassed with helium) at ambient temperature for 24 hours. The solvent was removed and the product triturated with diethyl ether and methanol and dried. Yield: 0.870. g (1.139 , 10-3 mole)=47% of theory MS (DCI) M/Z: 373 (5%), 329 (100%), 178 (71%) EXAMPLE 8 Radical formation The compounds of Examples 1 to 5 and 7 are converted to their radicals by oxidation in air or with benioquinone. EXAMPLE 9 ##STR46## 1-Hydroxy-2,3-diphenyl-7-cyanoindolizine The title compound was synthesized according to the procedure of D H Wadsworth, J. Org. Chem., 1986, 51, 4639. Yield 0.184 g (0.59 mmol, 49%) 1 H NMR (300 MHz) (Acetone D6) δ: 6.46 (dd, CH, 1H), 7.50-7.20 (m, 2-Ph, 10H), 7.90 (dd, CH, 1H), 8.01 (dd, CH, 1H) MS (Thermospray via loop) M/Z: 310 (M+, 100%) EXAMPLE 10 ##STR47## 1-Oxy-2,3-dipehnyl-7-cyanoindolizinyl The title compound was synthesized from the product of Example 9 according to the procedure of D H Wadsworth, J. Org. Chem., 1989, 54, 3652. The isolated green to black precipitate was analyzed by HPLC and the radical content was determined to be 20%. OMRI signal enhancement at 5 Watts=60 EXAMPLE 11 ##STR48## 1-Hydroxy-2,3-diphenyl-6,7-diamidoindolizine Diphenylcylcopropenone (0.250 g, 1.21 mmol) and 3,4-diamidopyridine (0.200 g, 1.21 mmol) were mixed in a dry, argon filled reaction flask. Chlorobenzene (2.5 mL) (oxygen free) was added, and the reaction was heated to 130C. After 2 h the heating was stopped and the reaction was allowed to reach room temperature. Petroleum ether 40-60C (2.5 mL) was added in order to obtain a complete precipitate of the product. The solvent was filtered off and the precipitate was washed with petroleum ether. Acetone (30 mL) was added to the crude product, and the mixture was stirred for 1h. The dark acetone solution was filtered off leaving a yellow precipitate. The precipitate was analyzed by HPLC (Kromasil C8, CH3 CN/H2 O). Two peaks were found with a ratio of 2:1. HPLC-MS showed that the larger peak was the desired product. Yield 0,155 g (0,418 mmol, 34%) MS (Thermospray after HPLC C18) M/Z: 371 (M+, 12%), 356 (14%), 344 (I7%), 326 (100%). EXAMPLE 12 ##STR49## 1-Oxy-2,3-diphenyl-6,7-diamidoindolizinyl 1-Hydroxy-2,3-diphenyl-6,7-diamidoindolizine (Example 11) was dissolved in THF and 4-benzoquinone was added. The reaction was stirred for 15 min at 50C. The colour changed during the reaction from yellow to dark red. The product was analyzed and the formation of the radical was determined by an OMRI experiment. OMRI signal enhancement at 5 Watts=70. EXAMPLE 13 ##STR50## 1-Hydroxy-2,3-diphenyl-6,7-dicyanoindolizine Diphenylcyclopropenone (0.319 g, 1.55 mmol) and 3,4-dicyanopyridine (0.200 g, 1.55 mmol) were mixed in a dry, argon filled reaction flask. Chlorobenzene (2.5 mL) (oxygen free) was added, and the reaction was heated to 130C. After 2 h the heating was stopped and the reaction was allowed to reach room temperature. Petroleum ether 40-60C (2.5 mL) was added in order to obtain a complete precipitate of the product. The solvent was filtered off and the precipitate was washed with petroleum ether. The crude product was stirred with chloroform (30. mL) for lb. The dark chloroform solution was filtered off leaving the title product as a yellow precipitate. Yield 0.100g (0.298 mmol, 19%) 1 H NMR (300 MHz) (DMSO D6) δ: 7.50-7.20 (m, 2-Ph, 10H), 8.29 (CH, 1H), 8.48 (CH, 1H) MS (Thermospray via loop) M/Z: 359 (30%), 353 (45%), 33.7 (100%). EXAMPLE 14 ##STR51## 1-Oxy-2,3-diphenyl-6,7-dicyanoindolizinyl 1-Hydroxy-2,3-diphenyl-6,7-dicyanoindolizine (Example 13) (10 mg, 0.03 mmol) was dissolved in DMSO (5 mL) and 4-benzoquinone (13.0 mg, 0.12 mmol) was added. The reaction was stirred for 15 min at 70C. The colour of the reaction became dark. The product was analyzed and the formation of the radical was determined by an OMRI experiment. OMRI signal enhancement (5 Watts) 80. EXAMPLE 15 ##STR52## 1-Mercapto-2,3-di-t-butylthio-7,8-dicyanoindolizine and 1-Mercapto-2,3-di-t-butylthio-6,7-dicyanoindolizine The title compounds are prepared according to the following reaction scheme ##STR53## a) Bis (t-butylthio)cyclopronenethione Silver tetrafluoroborate (21.8 g, 112 mmol) was dissolved in dry acetonitrile (50 mL) in a dry, argon filled reaction flask. The solution was cooled to -20C and tetrachlorocyclopropene (19.8 g, 11.0 mmol) dissolved in dry acetonitrile (25 mL) was added dropwise. When all was added the reaction was stirred for 0.5 h at -15C. The temperature was lowered to -20C and t-BuOH (50.0 mL, 444.0 mmol) dissolved in dry acetonitrile was added. The reaction was allowed to reach room temperature and was stirred over night. The precipitated AgCl was filtered off and the filtrate was concentrated, almost to dryness. Chloroform and water were added, and after vigorous shaking, the water phase was discarded. The organic phase was dried over Na2 SO4, filtered and evaporated. To the remaining crude product was added EtOAc (10 mL), and the mixture was stirred for 2 h. The dark oil transformed into yellow crystals (tris(t-butylthio)cyclopropenium tetrafluoroborate). The crystals were collected by filtration and were dissolved in a mixture of hydrochloric acid (50 mL, 2N) and THF (50 mL). The solution was refluxed for 4 h. After cooling to room temperature, chloroform (200 mL) was added. The organic phase was separated, washed once with water and dried over Na2 SO4. The title compound was purified by flash-chromatography (DCM : Petroleum ether 40-60C 1:1). Yield 7.92 g (32.2 retool, 29%) 1 H NMR (300 MHz) (CDCl3) δ: 1.67 (s) 13 C NMR (75 MHz) (CDCl3) δ: 169.7, 154.9, 50.8, 32.2 MS (Electron impact ionization) M/Z: 247 (M+I, 27%), 190 (35%), 134 (60%), 102 (14%), 59 (100%). b) 1,1'-(2.2',3,3'-tetra-t-butylthio-7,7',8,8'-tetracyano-diindolizine)-disulfide and 1,1'-(2,2',3,3'-tetra-t-butylthio-6,6',7,7'-tetracyano-diindolizine)disulfide Bis(t-butylthio)cyclopropenethione (0.382 g, 1.55 mmol) and 3,4-dicyanopyridine (0.200 g, 1.55 mmol) were mixed in a dry, argon filled reaction flask. Chlorobenzene (25 mL) (oxygen free) was added, and the reaction mixture was heated to 130 C for 70 h. The reaction was stopped and the crude product was purified by flash-chromatography (DCM: petroleum ether 40-600 75:25). A mixture of the title homodimer compounds and the heterodimer disulfide was obtained (91 mg). On TLC all three appeared in the same spot (Rf. 0.21/DCM: petroleum ether 40-60C 75:25). The isomers were. separated on HPLC (Kromasil KR100-10-CS, 250 x 10 mm, CH3 CH : H2 O 80:20). Yield: 7,7',8,8' dimer 0.027 g (0.03 6 mmol, 4.6% ) 6,6',7,7' dimer 0.009 g (0.012 mmol, 1.5%). hybrid dimer 0.028 g (0.036 mmol, 4.6%) 1 H NMR (300 MHz) (CDCl3) δ: (7,7',8,8' dimer): 8.98 (d, ArH, 1H), 6.86 (d, ArH, 1H), 1.30 (s, t-Bu, 9H), 1.20 (s, t-Bu, 9H). (6,6',7,7' dimer): 9.13 (d, ArH, 1H), 7.88 (s, ArH, 1H), 1.34 (s, tBu, 9H), 1.15 (s, t-Bu, 9H) MS (Thermospray after HPLC C18) (7,7'8,8') : M/Z 767 (M+19) (100%) (6,6',7,7'): M/Z: 767 (M+19) (100%). c) 1-Mercapto-2,3-di-t-butylthio-7,8-dicyanoindolizine 1,1'-(2,2',3,3'-tetra-t-butylthio-6,6',7,7'-tetracyanodiindolizine)-disulfide is treated with a reducing agent in an appropriate solvent until all disulfide is consumed. The reaction is stopped and the product is isolated by chromatography or recrystallization, or by a combination thereof. The radical is produced by conventional techniques. d) 1-Mercapto-2,3-di-t-butylthio-6,7-dicyanoindolizine 1,1'-(2,2',3,3'-tetra-t-butylthio-7,7,'8,8'-tetracyanodiindolizine)-disulfide is treated with a reducing agent in an appropriate solvent until all disulfide is consumed. The reaction is stopped and the product is isolated by chromatography or recrystallization, or by a combination thereof. The radical is produced by conventional techniques. EXAMPLE 16 ##STR54## 1-Mercapto-2,3-di-t-butylthio-7,8-diamidoindolizine The title product and the resulting radical are synthesized analogously to Example 15. EXAMPLE 17 ##STR55## 1-Mercapto-2,3-di-t-butylthio-6,7-diamidoindolizine The title product and the resulting radical are synthesized analogously to Example 15. EXAMPLE 18 ##STR56## 1-Mercaptor-2,3-di-t-butylthio-7,8-di(triethylammonium carboxylate) indolizine Bis(t-butylthio)cyclopropenethione and pyridine-3,4-dicarboxylic acid are mixed in a dried, argon filled reaction flask. A dry degassed solvent is added. To the mixture is added triethylamine. The reaction is stirred until no more product is obtained. The product is isolated either by chromatography or by recrystallization, or by a combination thereof. The radical is generated by conventional techniques. EXAMPLE 19 ##STR57## 1-Mercapto-2,3-di-t-butylthio-6,7-di(triethylammonium carboxylate) indolizine Bis(t-butylthio)cyclopropenethione and pyridine 3,4-dicarboxylic acid are mixed in a dried, argon filled reaction flask. A dry degassed solvent is added. To the mixture is added triethylamine. The reaction is stirred until no more product is obtained. The product is isolated either by chromatography or by recrystallization, or by a combination thereof. The radical is generated by conventional techniques. EXAMPLE 20 ##STR58## 1-Hydroxy-2,3-di-t-butoxy-6,7-dicyanoindolizine The title compound is prepared by the following reaction scheme ##STR59## a) 1.2.-Di-tert-butoxycyclobutenedione 3,4-Dihydroxy-3-cyclobutene-1,2-dione (5.0 g, 43.8 mmol) was dissolved in water (230 mL). While stirring the solution NaOH (87.7 mL, 1M, 87.7 mmol) was added dropwise. AgNO)3 (14.9 g, 87.7 mmol) dissolved in water (90 mL) was then slowly added to the solution. A yellow to green precipitate was formed. The suspension was stirred for 1 h. The precipitated silver salt was collected by filtration. It was washed with water, acetone and ether and was dried in vacum overnight. In a dry reaction flask the silver salt and dry ether (50 mL) were mixed. While stirring the suspension, t-butyl chloride (40.4 mL, 367 mmol) was added. After 48 h the reaction was stopped. The silver chloride formed was filtered off and washed with ether. The organic phases were washed with diluted NaHCO3 and with water, dried over Na2 SO4 and the solvent was evaporated. Yield: 3.33g (14.7 mmol, 34%) 1 H NMR (300 MHz) (CDCl3) δ: 1.61 (s, t-Bu). 13 C NMR (75 MHz) (CDCl3) δ:188.6, 186.2, 87.0, 28.6 MS (Thermospray after HPLC C18 ): M/Z: 228 (M+2) (24%), 173 (100%), 157 (37%), 117 (44%). b) 2,3-Di-tert-butoxycyclopropenone 1,2-Di-tert-butoxycyclobutenedione is dissolved in ether and photolyzed under nitrogen by a mercury high pressure lamp through quartz glass for 2-8h depending on the quality of the mercury lamp. The title compound produced is purified by HPLC-RP, recrystallization or by distillation at low pressure, or by a combination of this techniques. (See E V Dehmlow, Chem. Ber. 121, 569, 1988). c) 1-Hydroxy-2,3-di-t-butoxy-6,7-dicyanoindolizine 2,3-Di-tert-butoxycyclopropenone and 3,4-dicyanopyridine are mixed in a dry, argon filled flask. A solvent such as chlorobenzene (oxygen free) is used. After the completion of the reaction the product is purified by chromatography or recrystallization, or by a combination of these techniques. The radical is then generated by conventional techniques. EXAMPLE 21 ##STR60## 1-Oxy-2,3-di(t-butylthiol)-7,8-dicarboxylic acidindolizinyl The title compound was prepared by the following reaction scheme ##STR61## a) Bis(t-butylthio)cyclopropenone In a dry, argon filled reaction flask was placed bis(t-butylthio)cyclopropenethione (0.200 g, 0.81 mmol). Thionychloride (1.0 mL, 5.12 mmol) was added dropwise with stirring at room temperature. A yellow precipitate was formed. After 1 h excess of thionylchloride was removed under reduced pressure, using a Rotary evaporator connected to an oil pump and an ethanol-carbon dioxide trap. By adding CH2 Cl2 (5 mL) to the residual material a red solution was formed leaving a white precipitate. The solution was cooled to 0° C., washed with cold NaHCO3 (5%) and dried over Na2 SO4. The solvent was removed under reduced pressure. The product was filtered through a column of microcrystalline cellulose using petroleum ether as eluent and purified by recrystallisation from petroleum ether. Yield: 122 mg (0.53 mmol, 66%) 1 H NMR (300 MHz) (CDCl3) δ: 1.55 (s, t-bu) 13 C NMR (75 MHz) (CDCl3) δ: 152.2, 143.0, 48.8, 31.6 MS (EI): M/Z: 230 (M+) (25%), 202 (62%), 173 (65%), 146 (100%). b) 1-Hydroxy-2,3-di(t-butylthio)-7,8-dicarboxylic acid-indolizine 3,4-Pyridinedicarboxylic acid (1.31 g, 7.83 mmol) and triethyl amine (1.58 g, 15.7 mmol) were dissolved in chloroform (5.0 mL) (oxygen free) in a dry, argon filled reaction flask. Bis(t-butylthio)cyclopropenone (0.30 g, 1.30 mmol) was added. The reaction was stirred at 35° C. for 48h. The reaction was terminated and the product was purified by preparative HPLC (Kromasil C18, 250×20 mm, CH3 CN: H2 O, NH4 OAc pH=5). The product was unstable in the water-acetonitrile solution. It was therefore impossible to evaporate the solution. However, by allowing the fraction with pure product to stand in the freezer overnight the water and the acetonitrile were separated into two phases. The organic phase was separated and stored in the freezer. The product, which was dissolved in acetonitrile was stable in the freezer for months. Yield 0.052 g (0.130 mmol, 10%) 1 H NMR (300 MHz) (CDCl3) 5:8.54 (d, ArH, 1H), 7.15 (d, ArH, 1H), 3.2 (q, CH2), 1.4 (t, CH3), 1.29 (s, t-bu, 9H), 1.25 (s, t-Bu, 9H). MS (Plasma spray): M/Z: 398 (M+1) (4%), 352 (17%), 312 (100%), 256 (33%). c) 1-Oxy-2,3-di(t-butylthio)-7,8-dicarboxylic acidindolizinyl 1-Hydroxy-2,3-di(t-butylthio)-7,8-dicarboxylic acidindolizine (0.014 g, 7.83. mmol) was dissolved in sodium phosphate buffer (2.5 mL, pH=8). The solution was purged for 15sec. with air. The colour of the resulting solution was brown-green. ESR (water, 1.23 mM, 200G): doublet, aH =1.95 G, linewidth 73 mG. Overhauser enhancement (water, 1.23 mM): 144 at 16W microwave power. EXAMPLE 22 ##STR62## 1-Hydroxy-2,3-di-(8-methylthio-2,2,6,6 -tetramethylbenzo[1,2-d:4,5-d']bis(1,3)dioxole-4-yl)-6,7-di-(trialkylammonium carboxylate) indolizine The title compound is prepared according to the following reaction scheme ##STR63## a) 4-Hydroxyethyl-8-methylthio-2,2,6,6-tetramethylbenzo[1,2-d: 4,5,d']bis(1,3)dioxole 4-Hydroxymethyl-8-methylthio-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']bis(1,3)dioxole (see PCT/EP91/00285) is dissolved with stirring in dry THF in a dry, argon filled reaction flask. The solution is cooled to (-25)-(-30)C. Butyllithium in hexane is added dropwise with a syringe. The reaction is stirred for 0.5 h. In another reaction flask, a large excess of paraformaldehyde is depolymerized by heating. The formaldehyde formed is distilled, by means of an argon stream, into the reaction via a glass tube. When the reaction is complete, the product is hydrolyzed. The crude product is collected and is purified by recrystallization or chromatography, or by a combination of these techniques. b) 4-Bromomethyl-8-methylthio-2,2,6,6-tetramethylbenz[1,2-d:4,5-d']bis(1,3)dioxole 4-Hydroxymethyl-8-methylthio-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']bis(1,3)dioxole is dissolved in pyridine. The solution is chilled and triphenylphosphine followed by carbontetrabromide are added the reaction is stirred for an appropriate time. Methanol is added and the product is isolated by a suitable method. c) 1,3-Bis(8-methylthio-2,2,6,6-tetramethylbenzo[1,2d:4,5-d']bis(1,3)dioxole-4-yl) acetone 4-Bromomethyl-8-methylthio-2,2,6,6-tetramethylbenzo[1,2d:4,5-d']bis(1,3)dioxole is dissolved in dry ether in a dry, argon filled reaction vessel. The solution is cooled with a dry ice ethanol bath, With stirring, butyllithium in hexane is added. After the completion of the halogen metal exchange reaction ethyl (N,N-dimethyl) carbamate dissolved in dry ether is added. The reaction is hydrolyzed and the product is purified by chromatography or recrystallization, or by a combination of these techniques. d) 1,1-Dibromo-1,3-bis(8-methylthio-2,2,6,6-tetramethylbenzol[1.2-d:4.5-d']bis(1,3)dioxole-4-yl) acetone 1,3-Bis(8-methylthio-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d,]bis(1,3)dioxole-4-yl) acetone is dissolved in solvent. In the presence of base, bromine is added. After workup, the product is purified by chromatography or recrystallization, or by a combination of these techniques. e) 2,3-Di(8-methylthio-2,2,6,6-tetramethylbenzo[1,2d:4,5-d']bis(1,3 )-dioxole-4-yl)cyclopropenone Triethylamine is dissolved in CH2 Cl.sub. 2 with stirring. 1,1-Dibromo-1,3-bis(8-methylthio-2,2,6,6-tetramethylbenzol [1,2-d:4,5-d']bis(1,3)dioxole-4-yl) acetone in CH2 Cl2 is slowly added. After completion, the reaction mixture is worked up. The product is isolated by chromatography or recrystallization, or by a combination of these techniques. f) 1-hydroxy-2,3-di(8-methylthio-2,2,6.6-tetramethylbenzo[1,2-d:4.5-d']bis(1,3)dioxole-4-yl)-6,7di-(triethylammonium carboxylate) indolizine 2,3-Di(8-methylthio-2,2,6,6-tetramethylbenzo[1,2-d:4,5d']bis(1,3)dioxole-4-yl)cyclopropenone and pyridine-3,4-dicarboxylic acid are mixed in a dry, argon filled reaction flask. A dry, degassed solvent and triethylamine are added. The reaction mixture is stirred until no more product is formed. The product is isolated either by chromatography or by recrystallization, or by a combination of these techniques. The radical is generated by conventional techniques. EXAMPLE 23 ##STR64## 8-Oxyquinolinyl radical 8-Hydroxyquinoline (0.145 g, 1 mmol) was dissolved in a mixture of acetonitrile (20 ml) and DMSO (10 ml). Sodium hydroxide (1 ml of a 1 M aqueous solution) was added. p-Benzoquinone (0.43 g, 4 mmol) was dissolved in acetonitrile (20 ml). Both solutions were purged with argon for 30 minutes and then mixed. An instant colour change from yellow to dark green was observed. The formation of the radical was verified by ESR measurements. EXAMPLE 24 ##STR65## 8-Thiomethyl-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']bis(1,3)dioxole-4-oxy radical Sodium hydroxide (3.2 g, 80 mmol) and potassium ferricyanide (25.0 mg, 0.76 mmol) were dissolved in water (80 ml). 4-Hydroxy-8-thiomethyl-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']bis(1,3)dioxole (100 mg, 0.35 mmol) was then added and the solution was heated to 80C for 2 hours. A colour change from orange to pale green was observed the formation of the radical was verified by ESR measurements. ESR frequency 548.9 MHz. 5 lines with aH =106 mg, LW=53 mg. EXAMPLE 25 ##STR66## Phenol (502.1 mg, 5.335 mmol) was dissolved in DMF (4 mL, dry Aldrich sureseal). Sodium hydride (159.9 mg, 5.330 mmol, 80% in white oil) was washed twice with dry petroleum ether (decanting most of the petroleum ether after settling of the NaH), dired with argon gas and added to the phenolic solution. The resulting solution was stirred under argon while hydrogen evolved. When the gas evolution had ceased, tetrafluoroquinone (199.0 mg, 1.105 mmol) was added in portions, while cooling the mixture with an ice-water bath. The resulting solution was stirred 48 h, acidified with dilute HCl and evaporated. Water was added and the product was extracted with CHCl3 (3×50 mL). The organic phase was washed with water (25 mL), dried (Na2 SO4), filtered and evaporated yielding 0.7 g crude product. The pure product was obtained by flash chromatography on silica gel eluting with CHCl3. Yield 250 mg (47%). The product was identified by 1 HNMR- and 13 CNMR spectroscopy. 1 HNMR (CDCl3, 300 MHz) δ: 7.17 (m, 8H, Ar), 7.01 (m, Ar), 6.86 (m, 8H, Ar) 13 CNMR (CDCl3, 75 MHz) δ: 171.48, 156.37, 142.50, 129.46, 123.91, 116.80. Small amounts of a different product was also obtained in the chromatographic separation. Using MS and NMR data, this product was identified as: ##STR67## The semiquinone anion radicals are generated by convnetion techniques from the product of the Example. EXAMPLES 26 AND 27 The following products were synthesized in the same way as described in Example 25 (yield: 39%, and 45% respectively) ##STR68## The corresponding radicals-are generated using conventional techniques. EXAMPLE 28 ##STR69## This semiquinone was made according to: Methoden der Organischen Chemie--Houben Weyl pp 464-465 number VII/3a 1977. The product was crystallized from hot EtOH. The radical is generated using conventional techniques. EXAMPLE 29 ##STR70## PhSO2 Na (1.6579 g., 0.0101 mol) was dissolved in water (100 mL), while keeping an atmosphere of N2. HCl (12 M, 0.84 mL, 0.0101 mol). was added in order to produce PhSO2H. Benzoquinone (0.01 mol, 1.081 g) was added while flushing with N2. A white to grey precipitate was formed immediately. The solution was stirred for 5 min, filtered (glass sinter no. 3) under N2, washed with distilled water (20 mL) and dried under vacuum (+20C) over night. Yield 2.08 g. The product was identified by 1 H- and 13 CNMR spectroscopy. 1 H NMR (CDCl3, 300 MHz) δ: 6.82 (d, 1H), 7.01 (dd, 1H), 7.24 (d, 1H), 7.58-7.73 (m, 3H, Ph), 8.00 (m, 2H, Ph) 7.4-7.7 (b, OH, 2H) 13 CNMR (CDCl3, 75 MHz) δ: 150.72, 148.97, 141.91, 134.20, 129.83, 127.70, 125.43, 124.24, 119.88, 117.80, 114.47 ##STR71## Phenylsulfonylhydroquinone (0.0250 g, 0.1 mmol) was dissolved in CH2 Cl2 (4 mL). Silicagel (0.5 g) and NalO4 (0.65 M in H2 O, 0.5 mL) were added. The clear solution turned yellow quickly and the solution was filtered through a short plug of silica after 15 min stirring. The product was eluted with CH2 Cl2. Yield 0.0218 g. The product was identified by 1 H and 13 CNMR spectroscopy. 1 H NMR (CDCl3, 300 MHz) δ: 6.75 (d, 1H, J=10.2 HZ,), 6.86 (q, 1H, Ja =10.2 HZ, Jb =2.3 HZ) 7.62 (d, 1H, J=2.3 Hz), 7.55-7.62 (m, 2H, atom. H), 7.66-7.73 (m, 1H, arom. H), 8.07-8.12 (m, 2H, arom. H) 13 CNMR (CDCl3, 75 MHz) δ: 185.79, 180.82, 138.13, 37.07, 136.90, 136.84, 134.77, 129.67, 129.31. The radical is generated using conventional techniques. EXAMPLE 30 ##STR72## NaSO2 Ph (0.829 g, 5.05 mmol) was dissolved in H2 O (50 mL) under N2. HCl (0.42 mL, conc.) was added, followed by the monopenylsulfonylquinone (1.2413 g, 5 mmol). The quinone did not dissolve, and consequently, THF (50 mL) was added with concomitant dissolution of the substrate. A red colour appeared, which changed into brown within 15 min. HCl (2 drops, conc.) were added and the solution became clearer. pH was measured to be 5. TLC analysis indicated a new lipophilic product. The THF was evaporated off and the water phase was extracted with EtOAc (3×100 mL). In the first extraction some difficulties to separate the phases were observed. Addition of some saturated NaCl solution forced the phases apart. The combined EtOAc phase was washed once with saturated NaCl, dried (Na2 SO4), filtered and evaporated. The product was dissolved in EtOAc and filtered through a short silica column. Evaporation yielded a grey powder. Yield 30%. The product was identified by 1 H NMR spectroscopy. The radical is generated using conventional techniques. EXAMPLE 31 ##STR73## The hydroquinone is synthesized according to the procedure of Can. J. Chem. 1962, 40, page 1235. If desired the solvent may be changed to DMF and the reaction may be run at a higher temperature. The radical may be generated by conventional techniques. EXAMPLE 32 ##STR74## Sodium hydride (1.98 g, 0.066 mol, 80% in mineral oil), previously washed with dry petroleum ether (2×5 mL) and dried under a stream of N2 was added to a solution of EtSH (4.1006 g, 0.66 mol) in DMR (55 mL) at 0C. The resulting thick slurry was transferred to a dropping funnel and added gradually to a stirred (+10C) solution of chloranil (3.6882 g, 0.015 mol) in benzene (100 mL) over a period of 40 min. The reaction mixture was allowed to warm up to room temperature and stirred for 24 hours. Dilute HCl (ca 1 M) was added to pH 6. The solution was evaporated at ≦40C/4 mm Hg. The resulting black oil was partitioned between CHCl3 adn water (with a little dilute HCl added to ensure a low pH). The water phase was extracted with CHCl3 (4×100 mL). The combined CHCl3 phases were washed with water (1×100 mL) and dried (Na2 SO4). Evaporation gave a black oil, which crystallized in a water/ethanol mixture (dissolved in hot EtOH and hot water added until cloudiness appeared. The mixture was heated again and scratched to induce crystallization). The product was isolated in a yield of 300 mg as yellow crystals. The identification and verification were done with the help of 1 H NMR and IR spectroscopy and MS. 1 HNMR (CDCl3, 300 MHz) δ: 7.37 (s, OH, 2H), 2.92 (q, CH2, 8H), 1.21 (, CH3, 12 H) 13 CNMR (CDCl3, 75 MHz) δ: 152.42, 125.07, 29.73, 14.71 The use of a larger amount of EtSH resulted in a higher yield. The radical may be generated by conventional techniques. EXAMPLE 33 ##STR75## This reaction was perfomed analogously to Example 32. The product was identified by mass spectrometry. 1 HNMR (CDCl3, 300 MHz) δ: 7.69 (s, OH, 2H), 1.31 (s, CH3, 27H), 13 CNMR (CDCl3, 75 MHz) δ: 155.61, 128.03, 50.42, 31.59 The radical may be generated by conventional techniques. EXAMPLE 34 Tetraphenoxy benzoquinone is reduced with Na2 S2 O4 to the tetraphenoxy hydroquinone, as described by L Feiser et al., JACS 70, 1948, p 3165. The product is purified by crystallization or chromatography, or by a combination of these techniques. EXAMPLE 35 Tetraphenoxy benzoquinone is reduced with excess NaBH4 in a mixture of EtOH and water. The product is purified by extractions and chromatography, or by a combination of these techniques. The product is then monoalkylated or monoetherified to yield a phenoxy radical precursor as follows: ##STR76## Tetraphenoxyhydroquinone is monomesylated in pyridine with one equivalent of MeSO2 Cl for 2-3 days at ambient temperature. The product is isolated in low to moderate yield by extractions and chromatography. (See Annalen 551:235 (1942)) . EXAMPLE 36 ##STR77## 2,6-Diphenylsulfonyl hydroquinone is monomesylated in pyridine with one equivalent of MeSO2 Cl for 2-3 days at ambient to high temperature. The product is isolated and purified by extractions and chromatography. EXAMPLE 37 ##STR78## Tetraethylthiohydroquinone is monomesylated with MeSO2 Cl in pyridine at room temperature for 2-4 days. The product is isolated by extractions and chromatography. Radicals may be generated from the compounds of Examples 34-37 by conventional techniques. EXAMPLE 38 ##STR79## Tetraethylthiohydroquinone monomesylate is stirred with lead dioxide (excess) in the dark under an atomosphere of N2. Small samples are taken, centrifuged or filtered through oxygen-free silica and analysed by ESR, or by OMRI signal enhancement measurements. The product is purified by centrifugation, filtration and recrystallization or chromatography. EXAMPLE 39 ##STR80## 2,6-Dichlorohydroquinone monomethyl ether is stirred with an excess of K3 Fe(CN)6 in benzene until samples taken show high conversion to the radical. The product is purified as described in Example 38. EXAMPLE 40 Six phenoxy radical precursors are prepared according to the following reaction schemes (See also Muller, E. et al. Chem. Ber. 93, 2649 (1960): and Mu ller, E. and Lay, K. Chem. Bet. 87, 922 (1954)): ##STR81## The corresponding phenoxy radicals are generated by conventional techniques. EXAMPLE 41 A phenoxy radical precursor is prepared by a trimerization-condensation reaction as set forth below (see Martinson, P. et al., Acta Chem. Scand. 23:751-64 (1969)): ##STR82## In the first stage of the reaction scheme, to a hot solution of 1,3,5-tripivaloyl benzene and ethanedithiol in acetic acid is added dropwise BF3.OEt2 (48% in BF3) and the reaction mixture is left overnight for crystallization. After cooling, crystals separate. These crystals are filtered off and recrystallized for use in the later reaction steps. The phenol end product can be transformed into a radical directly or after oxidation of the sulphurs in the steric hindrance groups according to the reaction scheme below: ##STR83## In step (b) 2-hydroxy-1,3,5-tripivaloyl benzene trisethylenethioketal is dissolved in CH2 Cl2 at ambient temperature. Magnesium monoperphtalic acid (MMPA) and tetra-n-butylammonium hydrogensulphate (Q+HSO4. dissolved in water are added dropwise. The reaction is complete after several hours. The phases are separated and the organic phase is washed with a saturated solution of NaHCO3. The ether phase is dried (Na2 SO4) and the solvent evaporated leaving the product, which can be purified via distillation, crystallization or chromatography, or combinations thereof. EXAMPLE 42 ##STR84## (See Becker et al. New J. Chem 12:875-880 (1988)) ##STR85## p-Benzoquinone is dissolved in acetic acid (60%). The thiophenol is slowly added at ambient temperature with efficient stirring. After stirring (3-4 days) a voluminous red precipitate is formed and filtered off. The product can be crystallized and the two isomeric products (the 2,6- and 2,4-isomers, respectively) can be separated by chromatography. The reduction of the quinone product is performed in absolute EtCH with NaBH4. After stirring, 2 M HCl is added until pH=2-3. The ethanol is evaporated, and the residue is partitioned between ether and water. The ether phase is dried (Na2 SO4) and the solvent is evaporated, leaving a residue, which was used without further purification. The O-alkylation of the product (2,6-bisphenylthio hydroquinone) can be performed in dry dioxane with isobutylene, condensed into the solution, and a catalytic amount of concentrated sulfuric acid. The reaction flask is sealed and the reaction mixture is stirred at room temperature for 10 h. The reaction mixture is then neutralized with solid NaHCO3 (until CO2 evolution ceases).. After drying (Na2 SO4), the solvent is evaporated to give the t-butoxylated product. 2,6-Diphenylthio-4-t-butoxyphenole is dissolved in CH2 Cl2 and mixed with metachloroperbenzoic acid (MCPBA) and Q+HSO- 4, dissolved in water. Efficient stirring is maintained at reflux for 20 h. sodium sulphite is added to reduce the excess MCPBA. After concentration in high vacuum, the reaction mixture is worked up to give the product, which is purified via distillation, crystallization or chromatography, or combinations thereof. EXAMPLE 43 ##STR86## The reaction is performed according to the method of Ullman et al. Chem. Ber. 42.:2539-2548 (1909). If another oxidant is selected the same reaction sequence can be used to give the corresponding 5-COOH derivative. EXAMPLE 44 ##STR87## 3,4,5-trimethoxyphenol is dissolved in a 2 M solution of NaOH at room temperature. Formaldehyde solution (37%) is added and the mixture is stirred for two days at room temperature. The reaction mixture is then neutralized with diluted (50%) acetic acid (to pH=6-7) and the product is isolated and used without further purification in the next reaction step. The product of the first reaction step is dissolved in dry acetone and active MnO2 is added. The mixture is stirred for 24 h at room temperature. The mixture is filtered, and the filtrate treated with an acidic ion exchanger (e.g. Dowex 50 x B) and filtered again. After evaporation of the solvent the di-aldehyde product can be isolated. This compound is dissolved in glacial aceitc acid with warming. After cooling, ethanedithiole and a few drops of BF3.OEt2 are added. Stirring is maintained for 20 h. The acetic acid is evaporated at reduced pressure (1-2 torr) and the residue is the desired product, compound (A). The oxidation of the compound (A) takes place in glacial acetic acid with H2 O2 (35%). Stirring is continued at room temperature for 48 h. The excess peroxide is destroyed by the careful addition of a saturated solution of sodium sulphite. Compound (B) can then be purified via distillation, crystallization or chromatography, or combinations thereof. EXAMPLE 45 ##STR88## p-Hydroxymethyl phenol is etherified by dissolving it in dioxane, condensing isobutylene into the solution and adding a catalytic amount of mineral acid. This product can be converted to the di-hydroxymethyl derivative by addition to a solution of NaOH (50%) adn then adding, at room temperature, a solution of formaldehyde (37%). The oxidation of this product takes place with active MnO2 (20 equivalents) in acetone. In the next reaction step, the starting product is dissolved in glacial acetic acid, and ethanedithiol (2.5 equivalents), and a few drops of BF3.OEt2 are added. After stirring overnight, the reaction mixture is worked up by evaporation of the solvent. The residue is then purified by crystallization, distillation or chromatography, or combinations thereof. There follows another oxidation with MnO2, and the aldehyde is isolated and then condensed with an active methylene compound to give compund (A), according to the general procedures given by Mullet et al. (see Example 40). The phenol function can, by use of diazomethane, be protected to give compound (B), which can be oxidized with hydrogen peroxide (20 equivalents) in acetic acid. The excess peroxide is reduced by the addition of sodium sulphite. The product can then be purified by crystallization, distillation or chromatography, or combinations thereof. The methyl ether is cleaved to the phenol with hydrogen iodide in acetone. The mixture is evaporated to dryness at high vacuum, and the phenol can be converted to its radical by anion formation and oxidation. S-oxidation can take place without prior phenol protection. EXAMPLE 46 ##STR89## The starting compound is dissolved in dry Et2 O, and t-BuLl is added via a syringe. Stirring is continued for several hours at room temperature. After quenching with water, the phases are separated and the organic phase is worked up. The product is used directly in the next reaction step. In this it is dissolved in acetone and oxidized with active MnO2. After stirring at room temperature for 24 h, the mixture is filtered and the solvent is evaporated under reduced pressure. The product is then purified by crystallization, distillation or chromatography, or combinations thereof. The standard procedure for thioketalisation, as given above, is followed. The thioketal product is then purified by crystallization, distillation or chromatography, or combinations thereof. The thioketal is dissolved in acetone and MnO2 is added. After work up the aldehyde product is used directly in next step. The aldehyde compound is mixed with diethylmalonate and pyridine, according to the procedure given by Mullet et al. (see above). The product is then purified by crystallization, distillation or chromatography, or combinations thereof. It is then oxidized with hydrogen peroxide in acetic acid. After work up, including reduction of the excess peroxide, the product can then be purified by crystallization, distillation or chromatography, or combinations thereof. EXAMPLE 47 Radical formation The following schemes illustrate phenoxy radical formation techniques: ##STR90## Potassiumferricyanide (0.29 g, 0.8 mmol) was dissolved in water, which had been made alkaline with potassiumhydroxide. Diethylether (80 mL) was added, and into the mixture was bubbled argon for 30 minutes. 3,5-di-tert-butyl-4-hydroxybenzaldehyde (0.1 g, 0.4 mmol) was added. After 45 minutes, the organic phase became yellow and the presence of the radical was established with ESR measurements. 3,5-Di-tert-butyl-4-hydroxyanisole (0.1 g, 0.4 mmol) was dissolved in diethylether (80 mL), and into the mixture was bubbled argon for 30 minutes. Potassiumferricyanide (0.29 g) was dissolved in water (100 mL), which had been made alkaline with potassiumhydroxide and bubbled with argon for 30 minutes. The solutions were mixed and after 10 minutes the organic phase was red and the presence of the radical was established with ESR measurements. EXAMPLE 48 ##STR91## The S-methylated di-ketal (500 mg, 1.87 mmol) was dissolved in THF (50 mL, distilled over Na) under argon. The mixture was cooled to -70C, n-Butyllithium (0.8 mL, 2.0 mmol) was added through a syringe. The mixture was stirred at -70C for 2 hours. The Dewar flask was removed, and O2 was bubbled through the mixture for 3 h. Diethylether (50 mL) was added, and a solid precipitated. This was filtered off and dissolved in 1 N NaOH and washed with Et2 O. The organic phase was extracted twice with 1 N NaOH (10 mL). The alkaline water phase was acidified with concentrated HCl to pH 2 and then extracted with CH2 Cl2 (2×50 mL). After drying, filtering and evaporation the product was isolated (130 mg, 0.46 mmol; 25%). Radical formation is performed with KOH and K3 Fe(CN)6, as described above. EXAMPLE 49 ##STR92## Anthraquinone-2,6-disulfonic acid disodium salt (Aldrich A9,060-8) was dissolved in a water solution, buffered to pH 11, in a concentration of 2.5 mM. 0.25 equivalents NaBH4 was added and the ESR spectrum of the solution showed 23 lines with a linewidth of 28 mG at 200 G field strength. The Overhauser enhancement was 140 (14000%) at 5 W irradiating power--irradiating at the centre line. EXAMPLE 50 ##STR93## Anthraquinone-2,7-disulfonic acid disodium salt (Janssen) was dissolved in a water solution, buffered to pH 11, in a concentration of 2.5 mM. 0.25 equivalents NaBH4 was added and the ESR spectrum of the solution showed 23 lines with a linewidth of 50 mG at 200 G field strength. The Overhauser enhancement was 72 (7200%) at 5 W irradiating power--irradiating at the centre line. EXAMPLE 51 ##STR94## 2,3,5,6-Tetraphenoxy benzoquinone was dissolved in a mixture of THF and a water solution buffered to pH 11 (3.5/0.5) in a concentration of 2-5 mM. 0.25 equivalents NaBH4 was added and the ESR spectrum of the solution showed 9 lines with a linewidth of 16 mG at 200 G field strength. The Overhauser enhancement was 114 (11400%) at 5 W irradiating power--irradiating at the centre line. EXAMPLE 52 ##STR95## 2,3,5,6-Tetraphtalimido benzoquinone was dissolved in DMF in a concentration of 5.0 mM. 0.25 equivalents of NaBH4 was added adn the ESR spectrum of the solution showed 9 lines with aH=400 mG, with a linewidth of 30 mG at 200 G field strength. The Overhauser enhancement was 5 (500%) at 5 W irradiating power--irradiating at the centre line. EXAMPLE 53 ##STR96## 2,3,5,6-Dithienyl benzoquinone 2',2"-disulfonic acid di sodium salt was dissolved in a water solution, buffered to pH 11, in a concentration of 5.0 mM. 0.25 equivalents of NaBH4 was added and the ESR spectrum of the solution showed 3 lines with aH=180 mG with a linewidth of 28 mG at 200 G field strength. The Overhauser enhancement was 72 (7200%) at 5 W irradiating power -irradiating at the centre line. EXAMPLE 54 ##STR97## Galvinoxyl free radical (Aldrich G30-7) was dissolved in toluene at a concentration of 2.5 mM. The ESR spectrum showed one broad signal with an apparent linewidth of approximately 9.5 G at 200 G magnetic field strength. At 4.5 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 9.9 (9900%) was observed. EXAMPLE 55 ##STR98## BDPA free radical complex with benzene (Aldrich 15,256-0) was dissolved in toluene in a concentration of 2.5 mM. The ESR spectrum showed one broad signal with an apparent linewidth of approximately 9.0 G at 200 G magnetic field strength. At 5.0 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 165 (16500%) was observed. AT 21 mW irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 6 (600%) was observed. EXAMPLE 56 ##STR99## 1-Benzoyl indigo was dissolved in THF (10 mM) and NaBH4 (2.5 mM) was added. At 5.0 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 20 (2000%) was observed. EXAMPLE 57 ##STR100## 1,6-Dibenzoyl indigo was dissolved in THF (10 mM) and NaBH4 (2.5 mM) was added. At 5.0 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 65 (6500%) was observed. EXAMPLE 58 ##STR101## Potassium indigotetrasulfonate (Aldrich 23,408-7) was dissolved in water buffered to pH 11 at a concentration of 10 mM. Radicals were formed spontaneously in the solution. The ESR spectrum showed 15×3 lines with coupling constants of 600 and 126 mG. The apparent linewidth was 35 mG. At 5.0 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 70 (7000%) was observed. EXAMPLE 59 ##STR102## Rose bengal (Aldrich 19,825-0) was dissolved indegassed MeOH (10 mM) and heated. Radicals were formed spontaneously--presumably some oxygen in the solution worked as an oxidant. Formally the radical can be regarded as an aroxyl radical. The ESR spectrum of the cooled solution showed 13 lines with a linewidth of 181 mG. At 5.0 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 120 (12000%) was observed. EXAMPLE 60 ##STR103## 2,4,6-Triphenylphenoxyl dimer (Aldrich 27,245-0) was dissolved in toluene (dry, degassed with argon). The maximum concentration of dimer was 1.25 mM assuming no dissociation to radical monomers. The corresponding maximum concentration of radicals could theoretically be 2.5 mM assuming 100 % dissociation. This solution gave an ESR spectrum with an apparent linewidth of 5 Gauss. The intrinsic linewidth must however be much narrower, as seen from the Overhauser enhancement experiments which gave the following results: Irradiation with 24 mW effect gave 4.6 enhancements (460%) and irradiation 810 mW gave 26 enhancements (2600%). The irradiation frequency was at the centre of the ESR spectrum. EXAMPLE 61 ##STR104## 2,2-Diphenyl-1-picrylhydrazyl hydrate free radical (Aldrich D 21,140-0) was dissolved in a concentration of 2:5 mM in THF. The ESR spectrum showed one very broad signal at 200 G magnetic field strength. At 5.0 W irradiating power at the centre of the ESR spectrum an Overhauser enhancement of 39 (3900%) was observed. At 350 mW irradiating power an Overhauser enhancement of 5 (500%) was observed. EXAMPLE 62 ##STR105## N,N-bis-(2-hydroxyethyl)-3,5-bis-(1,1-dimethyl ethyl)-4-hydroxybenzenecarboxamide 3,5-bis-(1,1-dimetyletyl)-4-hydroxybenzenecarboxylic acid (2.5. g, 0.010 mol) and diethanolamine (1.05 g, 0.010 mol) were dissolved in 30 ml of dry dimethylformamide and dicyclohexylcarbodiimide (2.13 g, 0.0105 mol) in 10 ml of dry dimethylformamide was added over 5 minutes. After stirring overnight, the resulting colorless suspension was filtered, and the filtrate was evaporated, 3×25 ml of benzene was added and reevaporated to yield a white solid which was recrystallised from toluene. Yield: 2.0:6 g (61%) 1 H NMR (CDCl3, 300 MHz) δ: 7.34 (s, 2H, ArH), 5.42 (s, 1H, ArOH), 4.2-2.6 (m, 10H, CH2 CH2 OH), 1.43 (s, 18H, C(CH3)3) Mass spectrum (APcI, 25 V) : m/e (%rel.int.) 338 (100) (M+1), 321 (5), 174 (4), 115 (6), 106 (31). EXAMPLE 63 ##STR106## N,N-bis-(2,3-dyhydroxypropyl)-3,5-bis-(1,1-dimethylethyl)-4-hydroxybenzenecarboxamide 3,5-bis-(1,1-dimethylethyl)-4-hydroxybenzenecarboxylic acid (5.0 g, 0.020 mol) and bis-(2,3-dihydroxypropyl)amine (3.3 g, 0.020 mol) were dissolved in 60 ml of dry dimethylformamide and dicyclohexylcarbodiimide (2.13 g, 0.0105 mol) in 20ml of dry dimethylformamide was added. After stirring overnight the resulting colorless suspension was filtered, and the filtrate was evaporated, added 3×25 ml of benzene and reevaporated to yield a white solid; according to HPLC a mixture of starting material, title compound and at least two other products. The title compound was isolated by preparative HPLC. Yield: 0.1 g (1%) (not optimized, crude HPLC yield: ca 30%). 1 H NMR ((CD3)2 SO, 300 MHz) 6:7.20 (s, 2H, ArH), 5.02 (s, 1H, ArOH, 3.8-3.2 (m, 14H, CH2 CH(OH)CH2 OH), 1.36 (s, 18H, C(CH3)3). Mass spectrum: (APcI, 25V): m/e (rel.int.) 398 (100) M+1), 304 (5), 250 (7), 201 (9), 178 (2), 160 (16), 142 (48), 101 (45). EXAMPLE 64 ##STR107## N,N-bis-(2-hydroxyethyl)-2,6-bis-(1,1-dimethylethyl)benzene-4-carboxamide-1-oxy radical To a saturated solution of N,N-bis-(2-hydroxyethyl)-3,5-bis-(1,1-dimethylethyl)-4-hydroxybenzenecarboxamide in redistilled, Argon-flushed water (50 mg in 50 ml) 1.0 g of lead dioxide was added in one portion while flushing with argon. The flask was sealed with an ordinary stopper and teflon tape and thoroughly shaken. The dark green solution thus obtained was used directly for ESR-measurements.. ESR-data (H2 O, 0.75 mM): triplet, linewidth=900 mG; aH =1650 mG. EXAMPLE 65 ##STR108## N-N-bis-(2,3-dihydroxypropyl-2,6-bis-(1,1-dimethylethyl)-benzene-4-carboxamide-1-oxy radical To a saturated solution of N,N-bis-(2,3-dihydroxypropyl)-3,5-bis-(1,1-dimethylethyl)-4-hydroxybenzenecarboxamide in redistilled, Argon-flushed water (50 mg in 50 ml) was added in one portion while flushing with argon, 0.5 g of lead dioxide. The flask was sealed with an ordinary stopper and teflon tape and thoroughly shaken. The dark green solution thus obtained was used directly for ESR-measurements. ESR-data (H2 O, 3.79 mM): triplet, linewidth=900 mG; aH =1850 mG. EXAMPLE 66 ##STR109## 8-Methoxy-3,3,5,5-tetraoxo-2,2,6,6-tetramethylbenzo[1.2-d:4,5-d']-bis-(1,3)oxathiole-4-oxyl The title compound was prepared according to the following scheme: ##STR110## a) 2,2,6,6-tetramethylbenzo[1,2,-d:4,5-d']-bis(1.3)-oxathiole 2,6-Dioxo-benzo[1,2-d:5,4-d']bis(1,3)oxathiole (1.0 g, 4.4 mmol), prepared according to the literature (H. Fiedler, Berichte 95, 1771 (1962)) was suspended in dry methanol (30 mL) and a solution of sodium methoxide in methanol (prepared from 20 mL methanol and 2.2 mmol sodium) was then added over a period of 15 minutes. After stirring for 15 minutes, the mixture was poured onto diethyl ether (50 mL) and 1 M aqueous HCl (25 mL). The aqueous phase was extracted twice with ether and the combined organic phases were dried (MgSO4) and evaporated. The residue (0.60 g) was dissolved in dry acetonitril (40 mL) containing acetone (6 mL) and BF3.Et2 O (4 mL) was then added. After stirring for 20 minutes, water (100 mL) and dichloromethane (50 mL) were added. The aqueous phase was extracted twice with dichloromethane and the combined organic phases were dried (MgSO4) and evaporated. The brownish residue was passed through a short silica column using ethyl acetate:cyclohexane (1:5) as the eluent to give 0.30 g of a yellow solid which was further purified by preparative HPLC (RP-18, acetonitrile:water 80:20). Yield 0.25g (23%). 1H NMR (CDCl3) δ:1.80 (s, 12H, CH3), 6.35 (s, 1H), 6.75 (s, 1H). b) 8-t-Butoxy-2.2,6,6-tetramethylbenzo[1,2-d:5,4-d'bis(1.3) oxathiole 2,2,6,6-Tetramethylbenzo[1,2-d:5,4-d']bis (1,3)oxathiole (300 mg, 1.18 mmol) was dissolved in dry diethyl ether (30 mL) and the solution was cooled to -78° C. A solution of n-BuLi in hexane (2.5 M, 0.52 mL) was added and the reaction was allowed to attain room temperature. After stirring for 1 hour, the mixture was cooled to -78° C. and transferred into a solution of MgBr2 in dry ether (prepared from magnesium, 60 mg and 1,2-dibromoethane) 0.2 mL in 2 mL ether) kept at -78° C. The mixture was stirred for 30 minutes at 0° C. and then, a solution of t-butylperbenzoate (0.24 mL, 0.12 mmol) in dry ether (2 mL) was added. After stirring for 1 hour at 0° C., the mixture was poured onto a mixture of ice and 0.1 M aqueous HCl. The aqueous phase was extracted three times with ether and the combined organic phases were washed with aqueous NaHSO3, 2 M NaOH, dried (MgSO4) and evaporated. The product was purified by preparative HPLC (RP-18, CH3 CN: H2 O 80:20). Yield 124 mg (32%). 1 H NMR (CDCl3) δ:1.36 (s, 9H, t-Bu), 1.82 (s, 12H, CH3), 6.54 (s, 1H). c) 8-Methoxy-2,2,6,6-tetramethylbenzo[1,2-d;5,4-d']bis (1.3.)oxathiole 7-t-Butoxy-2,2,6,6-tetramethylbenzo[1,2-d;5,4-d']bis(1,3)oxathiole (152 mg, 0.47 mmol) was dissolved in 1,1,1-trifluoroethanol (4 mL) and cooled to -10° C. A solution of CF3 SO3 H in 1,1,1-trifluoroethanol (0.11 M, 0.52 mL) was then added and the mixture was stirred for 40 minutes at -5° C. A solution of triethyl amine in ether (0.14 M, 0.41 mL) was then added, the solution was evaporated and the product purified by preparative HPLC (RP-18, CH3 CN: H2 O 80:20). Yield 113 mg (90%). 1 H NMR (CDCl3) δ:1.86 (s, 12H, CH3), 4.74 (s, 1H, OH), 6.40 (s, 1H). This phenol was then methylated using phase-transfer conditions. Thus, a solution of the phenol (0.48 mmol, 130 mg) was dissolved in CH2 Cl2 (20 mL) together with tetrabutylammonium hydrogensulfate (163 mg, 0.48 mmol), 1M aqueous NaOH (20 mL) and methyl iodide (2.4 mmol, 0.15 mL). The mixture was stirred vigorously for 15 hours, the organic phase was evaporated and triturated with ether. The organic phase was washed with brine, water, dried (Na2 SO4) and evaporated. The product was purified by preparative HPLC (RP-18, CH]CN: H2 O 80:20). Yield 133 mg (97%). 1 H NMR (CDCl3) δ: 1.86 (s, 12H, CH3), 3.92 (s, 3H, OCH3), 6.52 (s, 1H). 4-t-Butoxy-8-methoxy-2,2,6,6-tetramethylbenzo[1.2-d;5,4-d'bis[1,3) oxathiole 7-Methoxy 2,2,6,6-tetramethylbenzo[1,2-d;5,4-d'bis(1,3)oxathiole (142 mg, 0.50 mmol) was dissolved in dry diethyl ether (20 mL) and cooled to -78° C. A solution of n-BuLi in hexane (2.5 M, 0.52 mL) was added and the reaction mixture was stirred for 2 hours at room temperature. After cooling to -78 ° C., the solution was transferred to a solution of MgBr2 in ether (prepared from magnesium, 24 mg, and 1,2-dibromoethane, 0.086 ml in 2 mL ether) kept at -78° C. After stirring for 45 minutes at 0° C., t-butylperbenzoate (0.6 mmol, 0.11 mL) in dry ether (2.0 mL) was added. After stirring for another hour, the mixture was poured onto a mixture of ice and 0.1 M HCl. The aqueous phase was extracted three times with ether, the combined organic extracts were washed with aqueous NaHS3, 2 M NaOH, dried (Na2 SO4) and evaporated. The product was purified by preparative HPLC (RP-18, CH3 CN: H2 O 80: 20 ). Yield 60mg(34% ). 1 H NMR (CDCl3) δ: 1.39 (s, 9H, t-Bu), 1.84 (s, 12H, CH3), 3.88 (S, 3H, OCH3). e) 4-Hydroxy-3,3,5,5-tetroxo-8-methoxy-2,2,6,6-tetramethyl-benzo[1,2-d;5,4-d']bis(1,3)oxathiole 4-t-Butoxy-8-methoxy-2,2,6,6-tetramethylbenzo[1,2-d; 5,4-d']bis(1,3)oxathiole (60 mg, 0.17 mmol) was dissolved in glacial acetic acid and aqueous hydrogen peroxide (3 mL, 36%) was added. The solution was heated to 100° C. for 1 hour. After neutralization of the solvent with aqueous 2 M NaOH, the mixture was extracted three times with ethyl acetate. The combined organic phases were dried (MgSO4) and evaporated. The product was purified by preparative HPLC (RP-18, CH3 CN: H2 O 80:20). Yield 25 mg (35%). 1 H NMR (DMSO-d6) δ:1.69 (s, 12H, CH3), 3.68 (s, 3H, OCH3), 3.8 (br s, 1H, OH). f) 8-Methoxy-3,3,5,5-tetraoxo-2,2,6,6-tetramethylbenzo[1,2-d;5,4-d']bis(1,3)oxathiole-4-oxy The radical is prepared from 4-hydroxy-3,3,5,5-tetroxo-8-methoxy-2,2,6,6-tetramethylbenzo[1,2-d;5,4-d']bis(1,3)oxathiole using either PbO2 or K3 Fe(CN)6 as the oxidant. EXAMPLE 67 ##STR111## 1-Bytyloxycarbonyl-1-bis[8-(4-methylthio-2,2,6,6-tetramethylbenzo[1,2,-d;4,5-d']-bis(1,3)dithiole)methyl The title compound is prepared according to the following scheme: ##STR112## 2,2,6,6-Tetramethylbenzo[1,2-d;5,4-d']bis-(1,3)dithiole is lithiated with n-BuLl in diethyl either and then reacted with dimethyl disulfide to give 4-methylthio-2,2,6,6-Tetramethylbenzo[1,2-d;5,4-d']bis-(1,3)dithiole. This compound can then be reacted with n-butyl glyoxalate (0.5 eq.) in a solvent consisting of a mixture of concentrated sulfuric acid and glacial acetic acid (1:10) (analogously to: G. Werber, Ann. Chim. 49, 1898 (1959)). After work-up, including neutralization and extraction the product is purified by preparative HPLC. The n-butyl bis[8-(methylthio-2,2,6,6-tetramethylbenzo[1,2-d;5,4-d']bis-(1,3)dithiole]acetate formed can be hydrolyzed with a 10% solution of sodium hydroxide and transferred into other esters, amides, thioesters and anhydrides etc. by standard procedures. If n-butyl bis[8-(methylthio-2,2,6,6-tetramethylbenzo-[1,2-d;5,4-d']bis-(1,3)dithiole] acetate is treated with n-BuLi (3 eq.) in tetrahydrofurane at ambient temperature and exposed to oxygen, the initially formed enolate anion is oxidized to the stable title radical (analogously to P. O'Neill and A. F. Hegarty, J. Org. Chem. 52, 2113 (1987)). EXAMPLE 68 ##STR113## N,N'-bis(2,3-dihydroxydroxypropyl)-2,4,6-triiodophenoxide-3,5-dicarboxylic acid diamide The title compound was prepared according to the following scheme: ##STR114## Dimethyl 1-hydroxybenzene-3,5-dicarboxylic acid 5-Hydroxyisophthalic acid (54.6 g, 0.30 mol, Aldrich 31, 127-8) was dissolved in absolute methanol (300 mL). Concentrated sulfuric acid (15 mL) was added and the reaction mixture was heated to reflux temperature for 19 hours and then cooled to -20° C. The precipitate was collected by filtration and the crude product was recrystallized in methanol. 1 H NMR (DMSO-d6) δ: 3.90 (s, 6H, CH3), 7.57 (d, 2H, J=1.5 Hz), 7.92 (t, 1H, J=1.5 Hz), 10..29 (s, 1H, OH). 13 C NMR (DMSO-d6) δ: 52.3.6, 120.2, 120.4, 131.3, 157.9, 165.4 N,N'-bis (2,3-dihydroxypyropyl)-1-hydroxybenzene-3,5-dicarboxylic acid diamide Dimethyl 5-hydroxyisophthalate (12.6 g, 60 mmol) was dissolved in methanol (36 mL) containing 3 -amino-1,2-dihydroxypropane (16.4 g, 180 mmol). The mixture was heated to reflux temperature for 10 days, and, after cooling to room temperature, was evaporated. Acetone (100 mL) was added to the residue and the crystalline solid was collected by filtration. The product was purified by recrystallization from acetone. Yield 9.0 g (46%). 1 H NMR (DMSO-d6) δ: 3.18-3.28 (m, 2H), 3.36-3.47 (m, 4H), 3.67 (p, 2H, J-8.4 Hz), 4.40 (br s, 4H), 7.39 (s, 2H), 7.78 (s, 1H), 8.36 (t, 2H, J=6.3 Hz). 13 C NMR (DMSO-d6) δ: 63.04, 70.31, 116.6, 116.7, 135.9, 157.2, 166.2. N,N-bis(2,3-dihydroxypropyl)-1-hydroxy-2,4,6-triodobenzene-3,5-dicarboxylic acid diamide N,N-bis(2,3-dihydroxypropyl)-1-hydroxy-2,4,6-triiodobenzene-3,5-dicarboxylic acid diamide (13.1 g, 40 mmol) was dissolved in water (160 mL) and pH was adjusted to 3.9 using aqueous HCl. To this solution, NaICl2 (42.6 g, 50.3%, 40 mmol) was added dropwise during a period of 30 minutes. After standing overnight, the reaction mixture was evaporated. The product was purified by preparative HPLC (RP-18, CH3 CN: H2 O 15: 85, 1% TFA). Yield 22.3 g (79%). 1 H NMR (DMSO-d6) δ: 3.08-3.21 (m, 2H), 3.22-3.55 (m, 4H), 3.62-3.75 (m, 2H), 5.4 (br s, 4H), 7.97-8.12 (m, 1H), 8.33-8.44 (m, 1H). N,N-his(2,3-dihydroxypropropyl)-2,4,6-triiodonhenoxide-3,5-dicarboxylic acid diamide N,N-bis(2,3-dihydroxypropyl)-1-hydroxy-2,4,6-triiodobenzene-3,5-dicarboxylic acid diamide (100 mg, 0.14 mmol) was dissolved in water (7 mL) under an atmosphere of argon. PbO2 (1 g) was then added and, after stirring for 10 minutes, the solid was allowed to settle and a sample was withdrawn for ESR analysis. Overhauser measurement: Enhancement of 38 (20 W microwave power). ESR: singlet, linewidth 1.08 G. We claim: 1. An electron spin resonance enhanced nuclear magnetic resonance imaging contrast medium comprising a physiologically tolerable persistent cyclic n-system free radical, said radical having an inherent linewidth in its esr spectrum of less than 500 mG, said radical having an electron delocalising n-system which comprises at least one heterocyclic ring, wherein said radical is an indolizinyl radical, together with at least one pharmacologically acceptable carrier or excipient. 2. A contrast medium according to claim 1 wherein the radical is a 2,3-diphenyl-1-hydroxylndolizlne-6,7-dicarboxyl radical. 3. A contrast medium according to claim 1 wherein the radical is a 2,3-diphenyl-1-hydroxyindolizine-7-carboxyl radical. 4. A contrast medium according to claim 1 wherein the radical is substituted on its skeleton by groups which are sterically hindering groups, electron donor groups, electron withdrawing groups, or solubilizing groups. 5. A contrast medium according to claim 1 wherein the radical is an indolizinyl radical of formula ##STR115## where R52 is an electron withdrawing group, a steric hindrance group or a solubilizing group; and each of R48, R49, R50, R53 and R53 is hydrogen or a steric hindrance or solubilizing group. 6. A persistent, water-soluble π-system free radical as defined in claim 1. 7. A non-radical precursor to a persistent, water-soluble π-system free radical as defined in claim 6. 8. A process for preparing a radical as defined in claim 6 comprising subjecting a non-radical precursor-therefor to a radical generation procedure. 9. A method of electron spin resonance enhanced nuclear magnetic resonance investigation of a sample, said method comprising introducing into said sample a persistent cyclic n-system free radical,said radical having an inherent linewidth in its esr spectrum of less than 500 mG, said radical having an electron delocalising n-system which comprises at least one heterocyclic ring, and said radical being an indolizinyl radical, exposing said sample to a first radiation of a frequency selected to excite electron spin transitions in said free radical, exposing said sample to a second radiation of a frequency selected to excite nuclear spin transitions in selected nuclei in said sample, detecting free induction decay signals from said sample, and optionally, generating an image or dynamic flow data from said detected signals.

1992-08-06

en

1995-07-25

US-37452595-A

Pane having improved properties ABSTRACT The invention concerns a monolithic or laminated pane of glass or of plastic materials which contains at least one glass sheet (8, 9). The edge face of the glass sheet is at least partly covered with a protective strip (11, 12) of elastomeric material which has a hardness less than 90 shore A. The protected strip is adhered to the edge face. The strip serves to protect the sheet from any shock or impact it receives during processing prior to assembly into a pane for use in aircraft or transportation vehicles. BACKGROUND OF THE INVENTION This invention relates to a pane, notably a pane used in the aeronautical sector. The pane may be monolithic or laminated, of glass or of plastics material, or it may also be a composite pane composed of an assembly of rigid sheets, of glass and/or of plastics material, and of flexible sheets. A composite pane used in the aeronautical sector is, commonly, composed of at least two sheets of thermally or chemically toughened glass, between which there is an intermediate sheet of plastics material which may, if desired, be composed of several plies or sheets. When the pane is in the usual conditions of a high altitude flight it is subjected, on the one hand, to considerable differences of pressure between its two faces and, on the other hand, to also considerable differences of temperature between the median part and the peripheral part of the pane. Furthermore, it is also subjected to vibrational loadings. As indications, the pressure difference may reach 900 millibars and the temperature difference may reach approximately 70° C. To these already high stresses there can be added stresses due, for example, to an impact in flight, in particular at low temperature, such as the strike of a bird, or other local stresses. As a result of these particularly high loadings, such panes deteriorate with use after a greater or lesser period. Solutions have already been proposed for reducing the risks of failure of the pane. One of the most common causes of failure is the difference in the coefficients of thermal expansion of the glass and of the intermediate sheet of plastics material which is, generally, of polyvinyl butyral. One solution consists of introducing a material having a low coefficient of thermal expansion into the marginal part of the pane, between the intermediate sheet and the glass. Another solution consists of placing a continuous film of a material of a difference nature having a lower modulus of elasticity between the intermediate sheet and the glass. These solutions may, however, lead to optical defects in the pane. There has also been proposed, in the document EP 508 864, an intermediate sheet of polyvinyl butyral composed of several plies, the plasticizer content of the plies in contact with at least one sheet of glass being higher than in the internal plies. This characteristic makes possible, also, a reduction and indeed an elimination of the known stresses leading to a cleavage of the glass, that is to say a rupture in a plane substantially parallel to the plane of the glass, notably when it is chemically toughened. These panes of the earlier documents have exhibited, as a whole, improved properties. They have satisfactory working lives. Nevertheless, in certain cases, important precautions are necessary during the production of the pane. The present invention overcomes these disadvantages. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a pane having the desired qualities of long life in the conditions of temperature and pressure to which a pane used in the aeronautical sector may be subjected. The inventors have achieved this result by demonstrating the stresses to which the pane is subjected during manufacture and installation in the aircraft fuselage. The inventors have demonstrated that, in particular, during handling it was possible for the pane to be subjected to shocks or impacts creating micro-defects which, although not visible, could cause deterioration of the pane. The inventors have also determined the characteristics for overcoming these defects and have found a solution compatible with the demands of the aeronautics industry and offering the advantage of being, in addition, easy to carry out. The invention concerns a pane, the edge face of which is at least partly covered by a strip or band. In one of its aspects, the invention concerns a pane comprising at least one sheet of glass, the edge face of which is, at least partly, covered by a protective strip. The material forming the strip according to this invention is chosen from among the following materials: silicone, rubber, thermosetting or thermoplastics elastomers. The material must be compatible, in particular, with the intermediate sheets or layers of plastics material used and with the seals that are generally installed at the periphery of the pane. These are seals for leak tightness and/or installation and/or removal, for example. These seals can be extruded or encapsulated. They are commonly of silicone. Furthermore, the material used according to this invention is, preferably, light in weight, that is to say with a density advantageously less than 1.2 g/cm3. The strip of this invention is preferably of polyurethane. The hardness of the strip is preferably higher than that of the seal in order to obtain a good assembling connection. It is preferably less than 90 Shore A and is, for example, between 60 and 90 Shore A. It is preferable, in addition, for the strip to have a good tear resistance. This is, preferably, higher than 2 kg measured according to standard ASTM 1938 and can even be as high as a value of the order of 2.5 kg. Preferably, the strip is left on the pane, which is mounted in the cockpit or fuselage of the aircraft. As we have seen earlier, the pane then undergoes considerable thermal stresses. For these reasons, the strip has a thermal dimensional stability after 30 minutes at 120° C. of less than 1%. Moreover, according to one advantageous variant of the invention, the strip covers, at least partly, the edge face of at least one sheet of glass and, preferably, of each of the glass sheets, taken individually, that form part of the pane. The strip is preferably applied onto the glass sheet before the manufacturing cycle for the pane. The glass sheet is then protected by the strip from any loadings from the start right to the end of the manufacturing steps and the installation of the pane. The strip should then have a thermal dimensional stability such that is withstands the heating conditions during assembly, which may reach more than 100° C. under pressure of 10 bars or more. The total thickness of the strip is preferably between 0.1 and 2 mm. The greater the thickness, the more will the strip according to this invention possess improved properties, in particular energy-absorber properties. Nevertheless, preferably, this thickness does not exceed 2 mm for reasons of bulk. It is obvious that each constituent of the pane has precise dimensions and that the dimensions of the whole of the pane must correspond exactly to the intended location provided in the body of the aircraft, for example. Furthermore, the edge faces of the pane are relatively of considerable size due, in particular, to the presence of various functional elements such as connecting, guiding elements and the presence of a seal or seals. Because of the small space available, the strip according to this invention advantageously comprises an adhesive film which, by the simple application of a pressure, enables the strip to be firmly fixed to the pane. The pressure may be applied, for example, by the application of a grooved roller, a spatula or any other means. The adhesive film is, preferably, of the acrylic type; it has a thickness of the order of 0.01 to 0.2 mm. The thickness is, preferably, of the order of 0.05 mm. The strip is advantageously unrolled from an unreeling device and immediately afterwards is applied against the edge face of the pane and, possibly also, may project onto the faces of the pane. The strip is thus applied uniformly in a simple and practical manner, in spite of the small thickness of a glass sheet, the thickness of which may, for example, be as small as 3 mm and in spite of the shape of the edge face which may, for example, be rounded. The glass sheet covered according to this invention is advantageously a sheet of chemically toughened glass, that is to say strengthened by a chemical treatment, itself known. This treatment consists, for example, of an ion exchange in the surface layers of the glass, the ions of small size being replaced by ions of larger size. This ion exchange creates a surface zone in compression. The strength of this surface zone in compression is particularly high. However, its thickness is less than that of a glass sheet that is thermally toughened. The present invention reduces the risk of deterioration of the surface of the glass during awkward or incorrect handling. DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the invention will become apparent from the remainder of the description, prepared with reference to an example of embodiment and to the figures, in which: FIG. 1 comprises various schematic layouts 1a to 1f, showing difference possible positions of the strip according to this invention, FIG. 2 shows, in section, one embodiment of a pane according to the invention, FIG. 3 shows, in section, a variant of a pane according to the invention, FIG. 4 shows, in section, another variant of a pane according to the invention, FIG. 5 shows, in section, another variant of a pane according to the invention, FIG. 6 shows, in section, another variant of a pane according to the invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a monolithic pane 1 composed on one sheet 2. This sheet is, for example, of glass. Its edge face 3, the arrises of which are referenced 5 and 6, is covered with a strip 4 according to the invention. In the arrangements 1a to 1c, the edge face 3 is rounded, whereas it is straight in the arrangements 1d to 1f. As illustrated in arrangements 1a and 1d, the strip may project onto the faces of the sheet 2. It may also project only on one face. It may moreover not project, while still protecting, for example, the arris 5 or the arris 6, as illustrated in arrangements 1b and 1e. It may also cover only a part of the edge face of the pane, as illustrated in arrangements 1c and 1f, while still protecting or not protecting the arris 5 and/or the arris 6. Only a few arrangements are illustrated in these schematic drawings. Other arrangements are, of course, possible without departing form the spirit of the invention. The pane according to this invention has improves properties, in particular an improved resistance to shock or impact. The results of tests carried out on the pane shown in arrangement 1a are as follows: The glass sheet is chemically toughened. If a steel ball is dropped on the rounded top of the glass sheet, simulating impacts during handling, defects are observed when the ball has an energy greater than or equal to 0.1 joule. If the same test is performed on the pane shown in arrangement 1a, provided with a strip of the silicone type, defects are observed for an energy of 0.5, 1 or 2 joules depending upon the thickness of the silicone strip, which is 1, 2 or 3 mm respectively. If the strip is composed of a polyurethane having a Shore A hardness of 80, a thickness of 0.41 mm and a tear resistance of the order of 2.6 kg according to test referenced ASTM 1938, defects appear for an energy greater than or equal to 9 joules. Furthermore, the strip is firmly fixed to the glass sheet. It is fixes there by an adhesive film of the acrylic type of thickness 0.04 mm. The adhesion values measured with a polyurethane strip described above are of the order of 1N/mm. These values are measured according to the test known at 180° peeling test, described in standard ASTM-D-100. The specimen tested are left for 24 hours at ambient temperature. The pulling speed in this case is 305 mm/min. As an indication, the drop test with a steel ball of 50 mm diameter and mass 500 g is performed on a plane specimen covered with a polyurethane strip according to the invention, as described above. This test simulates the shocks that the pane can experience during handling. The glass breaks for an energy greater than or equal to 10 joules whereas, for the same bare glass sheet, that is to say without a strip, the limiting energy is 3 joules. This example illustrates the improved properties of the pane according to this invention and the brittleness of the edges of the pane which can lead to breakage of the pane. As illustrated in FIG. 2, with advantage, a seal 7 is mounted at the periphery of the pane. This seal is preferably a leak tight and/or installation/removal seal. It is extruded or encapsulated. The pane 1 then comprises a so to speak composite seal, composed of the strip 4 according to the invention disposed according to arrangement 1a of FIG. 1, and of the seal 7. The strip may also be disposed in a different arrangement. It is then ready to be mounted in a bodywork opening or in a frame of a window or door, or in the cockpit or fuselage of an aircraft. The seal is, in this example, of silicone of thickness 2 mm, produced by encapsulation. The strip is, in this example, of polyurethane like that described in relation to FIG. 1. Defects appear when the energy of a steel cylinder falling onto the rounded top of the pane covered both with the strip 4 and the seal 7 is greater than or equal to 20 joules. The glass sheets illustrated in FIGS. 1 or 2 may also form part of a laminated pane as shown, for example, in FIGS. 3 and 5. FIG. 3 shows a laminated pane composed of two glass sheets 8 and 9, between which is an intermediate sheet of flexible plastics material 10. This intermediate sheet, shown schematically, may itself comprise several plies or sheets, possibly of different materials. In the figure two strips, 11 and 12, surround respectively the edge faces of the sheets 8 and 9. In this figure, the strip 11 is shown projecting onto the faces 13 and 14 of the sheet 9, whereas the strip 12 does not project. The figure thus illustrates the different possible positions of the strips relative to the sheets and the different possible superpositions of rigid or flexible sheets, without departing from the spirit of the invention. A seal, not illustrated, may also cover the whole of the edge face of the thus constituted pane. FIG. 4 illustrates another variant of the invention, in which the strip 15 according to the invention covers the entirety of the laminated pane. It is then applied after the assembling and does not need to be able to withstand, for example, the pressure and temperature conditions required for such an assembling. This pane may be used for transportation vehicles, for buildings etc. FIGS. 5 and 6 illustrate panes for aircraft according to a preferred variant of the invention. They are composed of three glass sheets 16, 17 and 18. The glass sheets 16 and 17, in particular the sheet 16, are exposed to the pressure and temperature obtaining inside the aircraft. The sheet 18 is, itself, exposed to the external conditions. A heating network 19 is usually provided in proximity to the sheet 18 for the purpose of removing the frost and/or mist from the pane. It is composed of electrical heating wires, not illustrated, electrically connected to electrical feeder strips, themselves connected via a connection element to an electrical supply source. Conductor wires for eliminating the static charges may also be provided. Intermediate sheets of plastic 20 and 21 are provided between the glass sheets. These are usually one or more sheets of polyvinyl butyral, optionally composed of several plies. In the embodiment illustrated here, the sheets 16 and 17 and also the intermediate sheet 20 are larger than the sheet 18 and the intermediate sheet 21. The intermediate sheet 21 may also be of the same dimensions as the sheet 17, for example. The intermediate sheet 20 is generally reinforced by a peripheral belt or insert, shown at 22, embedded in the intermediate sheet. This belt may comprise, if desired, holes for mounting the pane by bolting to the structure of the aircraft. This belt may be of an inoxidizable metal, of aluminium or based upon a fibrous structure. Its thickness is of the order of 2 mm. The strips 23, 24 according to the invention may cover the edge face of the sheets 16 and 17 as shown in FIG. 5. The strips 23 and 24 cover, at least partly, the edge face of the sheets 16 and 17, respectively, considered individually. These sheets are, of course, covered before they are assembled together, preferably just after they are manufactured. The strips may also cover the whole of the pane, as shown at 25 in FIG. 6. The strips 23, 24 and 25 may project or not onto the faces of the glass sheets, may cover in totality or only partly the edge faces of the sheets or of the pane. FIG. 5 illustrates an advantageous variant, in which the sheets 16 and 17 are of chemically toughened glass and, in addition, have a rounded edge. The sheet 18 may also be covered with a strip according to this invention. The method of production of a pane according to the invention, notably a laminated pane, comprises the following steps. A strip according to this invention is applied onto the edge face of a glass sheet, which has just undergone a chemical toughening treatment. The strip, comprising an adhesive film, is unreeled from a feeder device and is applied against the edge face, projecting if desired onto one or both faces of the glass sheet. With advantage, the application is performed by means of a grooved roller, to make the application highly uniform. The strip thus protects the glass sheet right from the start of the production cycle for the pane. A protective wrapping film may enclose the entirety of the glass sheet. This glass sheet can be stored. It is then assembled with other glass sheets, themselves perhaps also provided with strips according to this invention. The wrapping film, if provided, is of course removed before assembling. With advantage, several plies or sheets of flexible plastics material are disposed between these glass sheets, as well as a heating network, antistatic network, reinforcing belt etc. This assembly is preassembled by a calendering technique or by introducing the assembly into a bag, subjected to heat and placed under vacuum. The preassembly is then introduced into an autoclave, where it is subjected to a temperature of the order of 100° C. at 10 bars pressure. On leaving the autoclave, the assembly is firm and solid, that is to say the different plies constituting an intermediate sheet and also the intermediate sheet and the glass sheets are intimately bonded together. A silicone seal is then moulded onto the periphery of the pane. A wrapping film may, if desired, protect each of the faces of the pane. This pane is then mounted in the body of the aircraft by bolting or by mechanical fixing, for example by gripping. The wrapping film is, if present, then removed. The invention concerns monolithic or laminated panes, provided or not with a seal or any other element of glass or plastics material, without departing from the spirit of the invention. Although the invention has been described only in relation to panes used in the aeronautical industry, it may also be used for transportation vehicles or buildings or ships. We claim: 1. A monolithic or laminated pane of glass or plastic material for use in aircraft or transportation vehicles comprising at least one sheet of glass or plastic having an edge face, and a protective strip of elastomeric material adhered to said edge face and at least partly covering said edge face, said strip having a hardness less than 90 Shore A. 2. A pane as set forth in claim 1, wherein said elastomeric material of said protective strip is selected from the group consisting of silicone or polyurethane. 3. A pane as set forth in claim 2, wherein said elastomeric material is a polyurethane. 4. A pane as set forth in claim 3, wherein said polyurethane has a Shore A hardness in the range between 60 and 90 Shore A. 5. A pane as set forth in claim 1, wherein said strip has a tear resistance higher than 2 kg, measured according to ASTM 1938. 6. A pane as set forth in claim 1, wherein said elastomeric strip has a thickness between 0.1 and 2 mm. 7. A pane as set forth in claim 1, wherein said elastomeric strip includes an adhesive film component for bonding said protective strip to said edge and said adhesive film component of said strip has a thickness in the range 0.01 to 0.2 mm. 8. Pane according to claim 7, characterized in that the adhesive film is of the acrylic type. 9. A pane as set forth in claim 7, wherein said strip is capable of being unrolled from an unreeling device. 10. A pane as set forth in claim 1, which further comprises a seal mounted as the periphery of the pane, said strip being located between the edge of said glass or plastic and the inner surface of said seal. 11. A pane according to claim 1, wherein said pane comprises glass and said glass is chemically toughened. 12. A pane according to claim 1, wherein said pane is laminated. 13. A pane according to claim 4, wherein said pane is laminated. 14. A pane according to claim 10, wherein said pane is laminated. 15. In the process of preparing a glass laminate for aircraft, said glass laminate comprising a plurality of glass sheets having edge faces, the improvement comprising adhesively boding a protective strip of elastomeric material to at least part of the edge face of at least one of said glass sheets prior to assembly and lamination of said sheets to form a laminated assembly. 16. The process of claim 15, wherein at least those sheets exposed to the pressure and temperature obtained inside the aircraft are protected by said elastomeric strip. 17. The process of claim 15, wherein said laminate is composed of three glass sheets and the edge faces of all of said glass sheets are protected by said strip. 18. The process of claim 15, wherein after lamination, said glass sheets are intimately bonded together and a silicone seal is subsequently molded onto the periphery of the laminated pane, said strips being intermediate the silicone seal and said edge faces of said glass sheets. 19. The process of claim 15, wherein said strip is unrolled from an unreeling device and immediately afterwards is applied against the edge face of at least one of said sheets. 20. Pane according to claim 1, characterized in that the edge face of the pane is rounded.

1994-06-16

en

1996-12-17

US-36234689-A

Apparatus for producing two dimensionally bent glass ABSTRACT An apparatus for producing two-dimensionally bent and optionally tempered glass plates includes a roller oven (1), a pressing and bending station (2) and a cooling station (3). A lower male mold-like, full surface bending mold (10) with two-dimensionally shaped bending surface is arranged in the pressing and bending station (2). The top surface of the bending surface of the bending mold (10) is located in the conveying plane defined by the conveying rollers (5). The wall of the bending mold (10) forming the bending surface is provided with bores (14), which can be supplied with hot gas for forming a hot gas cushion. After positioning the glass plate (4) on the hot gas cushion, the female mold-like frame bending mold (11) is lowered onto the glass plate (4). The bent glass plate slides on the hot gas cushion into the cooling station (3). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing two-dimensionally bent and optionally tempered glass plates, with a roller oven for heating planar glass plates in a horizontal position to the bending temperature, a pressing and bending unit following the roller oven and a cooling device following the pressing and bending unit. 2. Background of the Related Art In a known apparatus for producing cylindrically bent glass plates, the conveying rollers have in the end portion of the roller oven a curvature which increases from roller to roller. The glass plate to be bent is conveyed into the bending station on the conveying rollers. The pressing and bending unit comprises a full or solid surface bending mold positioned above the conveying rollers and a frame bending mold lowerable below the supporting regions of the conveying rollers with which the glass plate is pressed against the upper full surface bending mold. The pressing process is followed by the bent glass plate again being placed on the conveying rollers with the aid of which it is brought into the following cooling station (German Patent 34 38 705). In order to reduce the deterioration to the optical quality of the heated glass plates resting on the conveying rollers within the bending station under the effect of the weight of the plates, in the known apparatus part of the glass plate weight is compensated by a hot gas flow directed from below against the glass plate between the conveying rollers. Despite these measures it is not possible to completely eliminate the influence of the non-uniform supporting of the glass plate by the conveying rollers. In addition, the known apparatus is relatively complicated and costly. SUMMARY OF THE INVENTION The object of the present invention is to provide an apparatus of the aforementioned type permitting the production of two-dimensionally bent glass plates with an even further improved optical quality. The apparatus according to the invention includes a pressing and bending unit comprising a lower male mold-like full surface bending mold with a two-dimensionally shaped bending surface, whose top surface is located in the conveying plane defined by the conveying rollers in the roller oven. The wall of the full surface bending mold forming the bending surface is provided with bores, which can be subject to the action of hot gas under overpressure for forming a hot gas cushion and that following the positioning of the glass plate on the hot gas cushion the female mold-like opposite mold is lowered onto the glass plate. In the case of the apparatus according to the invention, the lower bending mold is constructed as a full or solid surface bending mold, so that within the bending station no undesired deformations of the glass plate can occur as a result of the weight of said plate. Simultaneously, said full surface bending mold forms a hot gas cushion, on which the glass plate from the roller oven is brought in a floating manner into its position necessary for the bending process. During the passage of the heated glass plates into the bending station on the hot gas cushion a more or less marked prebending occurs due to the action of the weight of the glass plates. After positioning has taken place, i.e., immediately prior to the performance of the pressing process, the hot gas supply to the bending mold can be briefly interrupted, so that the glass plate is directly pressed by the upper mold onto the bending surface of the lower full or solid mold. The inventive apparatus is eminently suitable for the production of bent and tempered glass plates with a substantially planar central field and lateral region bent to a greater or lesser extent. Glass plates of this type are, e.g., used for the glazing of display cases. BRIEF DESCRIPTION OF THE DRAWINGS Appropriate developments and variants of the inventive apparatus form the subject matter of subclaims and can be gathered from the following description of embodiments with reference to the drawings, wherein: FIG. 1 is a perspective view, partly in section, of a first embodiment of the invention; FIG. 2 is a vertical longitudinal section along line II--II in FIG. 1; FIG. 3 is vertical cross-section along like III--III in FIG. 2; FIG. 4 is a vertical longitudinal view of another embodiment of the invention; FIG. 5 is a perspective view, partly in section, of another embodiment of the invention; and FIG. 6 is a vertical cross-section along lines VI--VI in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As can be seen from FIG. 1, the apparatus fundamentally comprises a horizontal roller oven 1, a bending station 2 and a cooling station 3, which in the illustrated case is constructed as a tempering station. The roller oven 1 is a horizontal continuous oven of known construction used for heating the glass plates 4 to the necessary bending temperature. The conveying rollers 5 on which the glass plates 4 are conveyed through the oven are driven in known manner. The end of the roller oven 1 is terminated by an end wall 6. The end wall 6 contains a slot-like opening 7, through which the heated glass plate passes out of the oven and into the bending station 2. Bending station 2 directly follows oven 1. The actual bending tools are arranged within a closed casing comprising a lower casing part 8 and an upper casing part 9. Within the lower casing part 8 is positioned the male mold-like bending mold 10 and within the upper casing part 9 the female mold-like bending mold as a frame bending mold 11. The male mold-like bending mold 10 is constructed as a full surface bending mold and constitutes in part the surface of a cylinder. The directrix of this cylinder surface corresponds to the desired cross-sectional shape of the glass plates to be produced. The generatrixes of the cylinder surface extend in the direction of the longitudinal axis of the plant, i.e., in the glass plate conveying direction. The central field of the bending surface is planar and the bending mold 10 is arranged at such a height that the generatrixes of said central field of the bending mold 10 are level with the conveying plane predetermined by the conveying rollers 5. As can be seen in FIGS. 2 and 3, the full surface bending mold 10 comprises a metal plate and is provided with a plurality of bores 14. The bending mold 10 forms the upper terminating plate of a closed chamber 15, into which hot gas under overpressure is passed. The hot gas, which has a temperature roughly corresponding to that of the glass plate 4, flows out of the bores 14 and forms a hot gas cushion on which the glass plate 4 floats, without it coming into contact with the surface of the bending mold 10 during the sliding movement. The necessary volume flow of the hot gas is produced by a fan 16. A heating unit 17 heats the gas flow to the necessary temperature. The hot gas can be drawn out of the opening 13 in the upper casing part 9 and returned in a circuit through line 18 to the pressure chamber 15. At its lower end, bending mold 10 has a flange 19, with the aid of which it is fixed to a corresponding flange 20 on the pressure chamber casing 15. If necessary, this makes it possible to replace the full surface bending mold 10 by another such mold. As can be gathered from FIG. 3, it can be appropriate to provide the lower side of the full surface bending mold 10 with partitions 22 and to supply the bending surface fields separated by these, namely the central field 22 and the two bent, lateral fields 24 and 25, separately with pressurized gas, whose volume flow and pressure can in each case be separately regulated. For this purpose, the partitions 22 in bending mold 10 are connected to corresponding partitions 26 within casing 15. The partial cavities 27, 28, 29 formed in this way are supplied with hot pressurized gas via separate connecting lines 30, 31 and 32 and via separate control valves 33. The frame bending mold 11 located within the upper casing part 9 can be raised and lowered with the aid of the pneumatic or hydraulic cylinder 35, or with the aid of a corresponding mechanical lifting means. Laterally of the lower bending mold 10 are provided lateral guide rollers 37 for the glass plate 4. The guide rollers 37 are used for keeping the glass plate 4 in the necessary position on its path from the roller oven 1 into the bending station 2 and within the latter. Stops 38, which can be lowered below the conveying plane, are used for positioning the glass plate 4 in the conveying direction. The lateral guide rollers 37 are mounted on a carriage 40, which is displaceable in rails 41 at right angles to the conveying direction of the glass plates 4. The carriage 40 can be moved into the desired position by a hydraulic cylinder 42 or by a corresponding mechanical drive. On the part of the carriage 40 projecting out of the lower casing part 8 is arranged an electric motor 44 which, by means of a driving belt or chain 45 drives one of the rollers 37. A heat-resistant material band 46 passes over the two rollers 37 and in this way is driven with a regulatable speed via driving belt 45. The thus driven band 46 serves to laterally guide the glass plate 4 on its way from the oven 1 into the bending station 2 and simultaneously, via the contact with the lateral edge of the glass plate 4, ensures the further conveying of the latter into the end position. The same arrangement of guide rollers 37 and a driven band 46 is provided on the facing longitudinal side of the bending station. Within the bending station 2 is also provided a conveying means, with the aid of which after carrying out the bending process, the glass plate 4 is moved from the bending station 2 into the following cooling station 3. In the illustrated case this conveying means comprises a slide 48, which is fixed to a rod 49, which is in turn respectively fixed on either side to endless chains 50. Each of the chains 50 is mounted in a laterally spaced manner from the bending mold on chain wheels or sprockets 51 above the conveying plane of the glass plates and at such a height that the slider 48 grips the rear edge of the glass plate 4 when the strip 49 with the slider 48 is located on the lower run of the chains 50. The chains 50 with the slider 48 are rotated by the controlled motor 52, the slider 48 moving the bent glass plate 4' out of the bending station and into the cooling station 3. The further conveying of the glass plates is taken over by driven conveying rollers 53 in cooling station 3. At the end of the sliding process, the slider 48 is detached from the glass plate 4' and returns to its starting position at the upper run of the chains 50, said starting position being located outside the area of the frame bending mold 11 during the pressing process. The following process sequence occurs when carrying out a bending cycle. As soon as the leading edge of a glass plate 4, which has been heated to the bending temperature in the oven 1, passes into the bending station and approaches the lower bending mold 10, with the aid of a (not shown) control circuit, fan 16 is switched on and consequently hot air acts from below on the perforated bending mold 10. The hot gas passing out of the bores 14 forms a hot gas cushion between the surface of the bending mold 10 and the glass plate 4. The glass plate 4, as a result of its kinetic energy or, if necessary, due to the frictional force transferred by the driven band 46, passes on the hot gas cushion to its end position, which is defined in the movement direction by stop 38 and is defined laterally by the rollers 37 and the band 46. As soon as the glass plate has reached its end position, the hot gas flow to the lower bending mold is interrupted, so that the glass plate 4 is applied to the bending mold 10. With the aid of the pressure cylinder 35, the frame bending mold 11 is now lowered and presses the glass plate 4 against the full surface bending mold 10. Stop 38 is then lowered by the pneumatic cylinder 55 and frees the path for the bent glass plate 4' into the cooling station. The pressure cylinder 35 then raises the frame bending mold 11 back into its upper end position. As soon as the path for the slider 48 is freed by the frame bending mold 11, motor 52 is switched on, so that the slider 48 is brought into its lower working position. Simultaneously the fan 16 is switched on again, so that once again a hot gas cushion is formed between the full surface bending mold 10 and the bent glass plate 4'. Floating on said hot gas cushion, the glass plate is moved with the aid of slider 48 onto the cooling station 3, where it undergoes accelerated cooling with cold air in a per se known manner with the aid of two blowing boxes 58, 59, which are in each case equipped with blowing nozzles 60, and is consequently tempered. Another possibility for conveying the bent glass plate 4' into cooling station 3 from bending station 2 at the end of the bending process is shown in FIGS. 4 and 5. In this case, the lower bending mold 10, including the pressure chamber 15 on the one hand and the blowing apparatus comprising the two blowing boxes 58, 59 on the other, are fixed to a common support frame 62, which is pivotably mounted about a horizontal spindle 63. With the aid of the hydraulic or pneumatic cylinder 64, the support frame 62 can be pivoted by an angle α. When the glass plate 4 passes from the oven 1 into the bending station 2, the support frame 62 is in its horizontal position. As soon as the glass plate 4 has reached its end position on the bending mold 10, it is tilted in the described manner with the aid of the frame bending mold 11. As soon as the bending process is ended and the frame bending mold 11 has again assumed its upper end position, hot compressed air is supplied to the pressure chamber 15. As a result the bent glass plate 4' is lifted from the mold surface as a hot gas cushion forms and the glass plate 4' floats on it. The pressure cylinder 64 is then operated and the support frame 62 is pivoted by an angle α. Due to its own weight, the glass plate 4' now slides into the cooling station, where it is taken over by the rollers 53 and passes into a (not shown) removal station. Also in the case of the apparatus shown in FIGS. 5 and 6, the lower bending mold 10, the pressure chamber 15 and the two blowing boxes 58, 59 are arranged on the common support frame 62, which is pivotable about pivot pin 63 with the aid of the pressure cylinder 64, so that following the bending process the glass plate 4' can be conveyed from the bending station into the cooling station 3. In this embodiment the central field 66 of the bending mold 10 is not planar and is instead slightly cylindrically bent. Thus, on entering the bending station, the glass plate 4 is supported by laterally arranged, additional gas cushion support means 68. The latter comprise pressure chambers adapted to the geometry of the bending mold 10, whose upper surface is planar and has bores 69, through which the hot gas flows out for forming the hot gas cushion. The support means 68 are supplied with hot pressurized gas via pressure lines 70. They are fixed to displaceably mounted rods 71 and are operated by pressure cylinder 72, which act on the two rods 71 by means of the connecting links 73. With the aid of one of the pressure cylinders 72, each support means 68 is brought into the working position shown in the drawings when the glass plate 4 leaves the oven 1 and passes into the bending station. As soon as the glass plate 4 has reached its end position in the bending station, the two support means 68 are retracted with the aid of the pressure cylinders 72, whereupon the glass plate engages on the lower bending mold 10 initially under its own weight and then under the action of the frame bending mold 11. On the support means 68 are in each case mounted two guide rollers 37 over which passes the flexible band 46. One of the rollers 37 is driven by motor 74 via driving chain 45. The motor 74 is in turn arranged on the connecting link 73. In this way, the lateral regions of the glass plates are supported from below with the aid of the described support means and are simultaneously guided on their lateral edges. They are optionally conveyed by friction grip and are thus brought into their end position, as defined by stops 75. If the lateral end regions of the glass plate 4 are to be strongly bent, it is advantageous to use as the upper frame bending mold a multipart bending mold, as shown in FIG. 6. The frame bending mold 77 is constructed in multipart form in per se known manner and it comprises a central part 78 and two lateral parts 78, 79 pivotably arranged on the central part 78. Side parts 79, 80 are in each case provided with a lever arm 81, to which is in each case articulated a lever 82. Levers 82 are in turn articulated to a crank mechanism 83, which is operated by a rod 84. The two side parts 79, 80 of frame bending mold 77 are flapped downwards with the aid of rod 84, as soon as the bending mold 77 has been lowered onto the glass plate resting on the lower mold 10 with the aid of the piston rod 85 operated by a pressure cylinder. Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. What is claimed as new and desired to be secured by Letters Patent of the United States is: 1. An apparatus for producing two-dimensionally bent glass plates, comprising:a roller oven having horizontally extending conveying rollers, for heating a horizontally positioned glass sheet to a bending temperature; a pressing and bending unit positioned downstream of said roller oven in a glass sheet conveying direction, comprising:(a) a lower full surface male bending mold having a perforate top surface lying in a plane defined by said conveying rollers, (b) means for supplying pressurized hot gasses to the perforations of said lower bending mold, whereby a hot gas cushion may be formed between said lower bending mold and a glass sheet in said pressing and bending unit, (c) a female mold positioned over said lower bending mold, and (d) means for vertically moving said female mold towards said lower bending mold for pressing and bending a glass sheet resting thereon; a cooling device positioned downstream from said pressing and bending unit for cooling a bent glass sheet; and means for conveying a glass sheet from said roller oven to said pressing and bending unit and means for transferring a bent glass sheet from said pressing and bending unit to said cooling device. 2. The apparatus of claim 1 including means for selectively controlling the supply of hot gases in said hot gasses supplying means. 3. The apparatus of claim 1 wherein said means for transferring a bent glass plate from said pressing and bending unit to said cooling device, comprises a slider movable to a position for contacting and pushing on a downstream edge of a glass sheet in said pressing and bending unit. 4. The apparatus of claim 1 wherein said means for transferring a bent glass plate from said pressing and bending unit to said cooling device comprises means for tilting said lower bending mold. 5. The apparatus of claim 1 including means for positioning a glass sheet on said lower bending mold in a direction lateral to said conveying direction. 6. The apparatus of claim 5 wherein said positioning means are adjustable in the direction lateral to said conveying direction. 7. The apparatus of claim 5 wherein said positioning means are positioned on two lateral sides of said lower bending mold, the positioning means on each lateral side of said lower bending mold comprising:two rollers rotatable about vertical axes and spaced in the conveying direction; and an endless, flexible, heat resistant band running around said two rollers. 8. The apparatus of claim 7 including means for driving at least one of said two rollers. 9. The apparatus of claim 1 wherein said means for supplying hot gasses comprises means for forming a pressure chamber for which said lower bending mold is a top surface, wherein said means for forming a pressure chamber including a casing detachable from said lower bending mold. 10. The apparatus of claim 9 including means for dividing said pressure chamber into plural cavities, wherein said lower bending mold is divided into plural fields respectively fluidically communicating with said plural cavities. 11. The apparatus of claim 1 including laterally movable gas cushion support means positioned at lateral sides of said lower bending mold and having upper surfaces coplanar with said conveying rollers. 12. The apparatus of claim 1 wherein said female bending mold is a multi-part bending mold having a central part and side parts pivotally connected thereto. 13. The apparatus of claim 1 including a casing enclosing said pressing and bending unit. 14. The apparatus of claim 13 including means for recirculating hot gasses from said casing to said hot gasses supplying means.

1989-06-06

en

1991-04-23

US-78365358-A

Variable bandwidth tracking system Sept. 14, 1965 Filed Dec. 26, 1958 R- D. M COY VARIABLE BANDWIDTH TRACKING SYSTEM 2 Sheets-Sheet 1 I i I I 3.2 3o 40 37 i 29 /244 i J PA? A W9 "/6 4/ IE-Ek/fl DUPLEXER 4 REcEIvER TRANSMITTER 22 f 'VARIABLE 49 ELEVATION PRE- CONTROL 4 PowER DETECTOR AMPLIFIER AMPLIFIER AMPLIFIER BANDWIDTH ADJUSTER VARIABLE AzIMuTI-I PRE- PowER y CONTROL DETECTOR AMPLIFIER F; AMPLIFIER L k AMPLIFIER 49 L 25 as I as BANDWIDTH ADJUSTER INVENTOI? GENT Sept. 14, 1965 R. D. M coY 3,205,753 VARIABLE BANDWIDTH TRACKING SYSTEM Filed Dec. 26, 1958 2 Sheets-Sheet 2 REC'gFlER FILTER acceleration. United States Patent 3,206,753 VARIABLE BANDWIDTH TRACKING SYSTEM Rawley D. McCoy, Bronxville, N.Y., assignor, by mesne assignments, to Dynamics Corporation of America, New York, N.Y., a corporation of New York Filed Dec. 26, 1958, Ser. No. 783,653 17 Ciaims. (Cl. 343-117) This invention relates to positional control systems, and in particular to apparatus for automatically positioning a directive element for tracking a moving object. Radar systems used for fire control, missile guidance, and similar applications must be designed to track moving targets with great accuracy. Tracking must also be accomplished as smoothly as possible without unduly sacrificing system accuracy. An important factor in determining both the tracking accuracy and the smoothness with which a radar system will operate when following a maneuvering target is the bandwidth of its antenna servo positioning system. A wide bandwidth will provide a tight, accurate system having a relatively short time constant while a narrow bandwidth will result in a smoother system having a longer time constant. A target whose angular velocity is changing rapidly relative to the tracking station will produce an error control signal comprised of a wide band of frequency components. If the radar is to follow this target with a minimum of lag between the directive axis of the antenna and the true direction to the target, the antenna positioning servos must respond to all significant frequency components in the received signal. The servo pass band must, therefore, be wide enough to amplify all significant signal frequencies even though this mode of operation may result in some reduction in smoothness due to increased gain at the higher noise frequencies. On the other hand, a radar system tracking a distant target, or a target moving with essentially constant angular velocity relative to the radar will receive signals having predominately low frequency components. Under these conditions the servo bandwidth may be narrow, thereby amplifying the low-frequency signal frequencies while, at the same time, improving tracking smoothness by attenuating all noise frequencies above the pass band. It is highly desirable, therefore, that a radar tracking system possess a wide bandwidth when tracking targets having a high angular acceleration and a narrow bandwidth when tracking targets having a low, or zero, angular It is further desirable that this bandwidth be continuously variable as a function-of target movement, and that such change in bandwidth be accomplished automatically rather than manually. Accordingly, it is a principal object of this invention to provide an improved variable bandwidth positional control system. Another object is to .provide a variable bandwidth positional control system wherein the bandwidth is automatically varied as a function of the magnitude of the error signal. Still another object is to provide an automatic tracking system in which the response of the elevation and azimuth error channels are individually controlled by the magnitudes of the elevation and azimuth error signals respectively. Yet another object is to provide an automatic tracking system in which the bandwidth is automatically increased and decreased at different rates. A further object is to provide an automatic tracking system in which the response of the elevation error channel and the response of the azimuth error channel are controlled by the sum of the elevation and azimuth error signals. Still a further object is to provide a variable bandwidth positioning system in which the system damping ratio is maintained constant while the bandwidth is varied. The foregoing objects are achieved in the present invention in which the bandwidth, or response, of a servo amplifier is varied as a function of the magnitude of the error signal. The invention is especially suited for use in an automatic tracking system, and will be described in connection therewith, although it should be understood that it is not limited to this particular application. In the type of automatic tracking system to be disclosed a directive antenna is provided which may be positioned in elevation and azimuth by separate drive motors. Radio frequency energy, reflected or transmitted from a target, is received at the antenna and conducted to a radio receiver having its output coupled to elevation and azimuth detectors. Error voltages, proportional to the angular difference between the target and antenna positions, are generated in the detectors, amplified, and applied to the elevation and azimuth antenna drivemotors which position the directive axis of the antenna. Servo systems may be made with configurations resulting in a predominant velocity error, acceleration error, or rate of change of acceleration error. For automatic tracking radar systems, with narrow bandwidth servo characteristics, a system with an acceleration error character istic and essentially zero velocity error characteristic is usually used. The following discussion describes a system with such a configuration with essentially zero velocity error. When a target having a low angular acceleration is being tracked the magnitude of the error voltage is relatively small since the radar antenna follows the target closely. The frequency components in the received signal are comparatively low and the bandwidth of the system may be narrow thereby providing improved noise suppression. At increased target angular accelerations, the antenna will lag further behind the target and the error voltage will increase. The servo bandwidth must then be increased so that the system will respond to the higher frequency components present in the signal, thereby decreasing the lag angle between the directive axis of the antenna and the true direction to the target. It is seen, therefore, that a small error voltage corresponds to the conditions under which a narrow bandwidth is needed and that a large error voltage is an indication that a'relatively wide bandwidth is required. In one embodiment of the invention, the output of the radar receiver is separated into elevation and azimuth error voltage components, and each component, atfer amplification in an associated variable control amplifier, is coupled to the corresponding elevation or azimuth drive motor. The elevation error voltage component is also coupled through a low-pass network to attenuate the high-frequency noise components, rectified .to produce a voltage proportional to the magnitude of the filtered error voltage, and then coupled to a positional servo. The positional servo drives potentiometers in the variable control elevation amplifier which adjust the bandwidth of this evelaticn channel in accordance with the magnitude of the filtered elevation error voltage while simultaneously keeping the damping ratio of the elevation channel constant. Similarly, the azimuth error voltage component is filtered in a low-pass network, rectified, and used to drive another positional servo which positions potentiometers in the variable control azimuth amplifier. The bandwith of the azimuth channel is thereby varied in accordance with the magnitude of the filtered azimuth error voltage while the damping ratio of the azimuth channel is held constant. Thus, the bandwith of the elevation channel is made to vary directly with the magnitude of the elevation error signal, and the bandwidth of the azimuth channel is varied directly with the magnitude of the azimuth error signal. Non-linear circuit means are also included in both channels for increasing the bandwidth at a faster rate than it is decreased. It should be understood that the invention is not restricted to second order servo systems but may be used in conjunction wi-th other types of systems as well. In another embodiment of the invention, the elevation and the azimuth error signals are combined to form a single error voltage which simultaneously controls the response of both the elevation and azimuth channels. A good approximation is thereby obtained to the true error voltage with a considerable saving in equipment. The above objects and the brief introduction to the present invention will be more fully understood and further objects and advantages will become apparent from a study of the following detailed description in connection with the drawings wherein: FIG. 1 is a block diagram of a preferred embodiment of the present invention, FIG. 2 is a schematic representation of a portion of the system of FIG. 1, and FIG. 3 is a schematic representation showing another embodiment of the invention. Referring to FIGURE 1, a scanner comprising a parabolic reflector 11 and an antenna 12 is adapted for the transmission of electromagnetic energy in the form of a directional beam. The antenna 12, which is used for both transmitting and receiving, is located at the focus of parabolic reflector 11 and is rotated by a motor 13 and conventional nutating mechanism (not shown) about the directive axis a-a of the scanner. Due to the motion of antenna 12 relative to reflector 11, the transmitted beam of electromagnetic energy describes a cone of radiation as shown by dashed lines in FIG. 1. A high-frequency transmitter 14 couples pulser of radio energy through a duplexer 15 and wave guide 16 to the antenna 12. Any target which appears Within the cone of radiation will reflect a portion of the received energy back to the antenna, and this energy is conveyed through wave guide 16 and duplexer 15 to the radar receiver 17. A rotating joint 18, in Wave guide 16, permits azimuth drive motor 19 to turn scanner 10 continuously in the azimuth plane. In conical scanning, the amplitude of the electromagnetic energy received from the target depends upon the angular displacement of the target relative to the directive axis of the radio beam. Since the beam is rotated in a conical path, the reflected energy varies in strength as the beam is rotated. Therefore, the reflected energy received by the antenna is amplitude modulated at a frequency corresponding to the nutating frequency of the antenna, and the amplitude of the modulation is a function of the displacement of the target relative to the directive axis a-a. The phase of the modulation is a function of the position of the target relative to the directive axis. The energy reflected from the target and supplied to receiver 17 provides a measure of the angle between the directive axis of scanner 10 and the true direction of the target. The output of receiver 17 is an error signal which varies in amplitude at the nutating frequency and may be considered to have elevation and traverse angle error components. The elevation angle component is measured in the vertical plane while the traverse angle component is the angle measured at the radar in a slant plane including the target and the radar antenna. The traverse angle component is not, in general, equal to the azimuth angle which is measured in the horizontal plane and, since the directive axis of the scanner may he inclined with respect to the horizontal plane, a secant correcting potentiometer 36 is provided for transforming the error component in the traverse plane to an equivalent error component in the azimuth plane. This correction is needed in the azimuth channel to keep the channel sensitivity constant as the elevation angle of scanner 10 is changed. The practical range of secant potentiometer 36 is limited to about since the secant of the elevation angle approaches infinity as the angle approaches The output of receiver 17 is coupled directly to elevation detector 22 by a lead 20 and to one terminal of secant potentiometer 36 by a lead 21. The rotating arm 37 of potentiometer 36 is attached to elevation drive motor 28 by a mechanical connection shown schematically by dashed line 38 so that the displacement of potentiometer arm 37 corresponds to the elevation angle of scanner 10. Arm 37 of potentiometer 36 is electrically coupled to the input of azimuth detector 23 by means of a lead 21a and, since the resistive winding 40 of potentiometer 36 is formed so that the voltage on arm 37 varies as the secant of the elevation angle, the output signal of receiver 17 is modified by this function before application to azimuth detector 23. A two-phase generator 24, driven in synchronism with antenna 12, provides quadrature reference voltages coupled by means of leads 24a to elevation and azimuth detectors 22 and 23. The phase of the modulation on the received signal is compared with one reference voltage in elevation detector 22 and with the other reference voltage in azimuth detector 23. Since the reference voltages are 90 out of phase with each other and since the elevation and azimuth axes are perpendicular, the magnitude of the output voltage of elevation detector 22 is proportional to the elevation angle error while the magnitude of the output voltage of azimuth detector 23 is proportional to the azimuth error angle. The output of elevation detector 22 is coupled through preamplifier 25, variable control amplifier 26 and elevation power amplifier 27 to the elevation drive motor 28. The scanner 10 is suspended between the parallel arms of a supporting yoke structure 29 and is pivoted in elevation by drive motor 28. A tachometer 30, which is mounted in the same case as elevation drive motor 28, provides derivative feedback over lead 31 to the input of elevation amplifier 27. The output of preamplifier 25 is also connected to a bandwidth adjuster 32 which varies the bandwidth of the elevation channel in accordance with the magnitude of the elevation error signal. Details of bandwidth adjuster 32 will be described hereinafter. The output of azimuth detector 23 is coupled through preamplifier 33, variable control amplifier 34 and azimuth power amplifier 35 to azimuth drive motor 19 which positions scanner 10 in the azimuth plane through gearing 39. A tachometer 41 is mounted within the case of azimuth drive motor 19 being connected by lead 42 to the input of azimuth amplifier 35 thereby providing derivative feedback in the azimuth channel. The output of preamplifier 33 is also coupled to a bandwidth adjuster 43 which controls the bandwidth of the azimuth channel in accordance with the magnitude of the azimuth angle error voltage. In FIGURE 2, details of preamplifier 25, variable control amplifier 26 and bandwidth adjuster 32 are shown. It will be understood that similar components are used in the azimuth channel and that the following explanation also applies to preamplifier 33, variable control amplifier 34 and bandwidth adjuster 43. The output of elevation detector 22 is coupled to a terminal 48 and through an input resistor 50 to a D.-C. amplifier 51, amplifier 51 having a feedback resistor 52 coupled between its input and output terminals. The output of amplifier 51 is connected through a resistor 55 and potentiometer 56 to ground while the arm 57 of potentiometer 56 is electrically coupled to one end of a second potentiometer 58. The arm 59 of potentiometer 58 is connected through a resistor 60 to an integrating amplifier 61 having a feedback capacitor 62 connected across it. The output of amplifier 61 is coupled through an input resistor 63 to an inverting amplifier 64, having a feedback resistor 65, while the output of amplifier 64 is coupled through a resistor 66 to summing amplifier 67. The arm of potentiometer 56 is connected to summing amplifier 67 through a resistor 68, summing amplifier 67 having a feedback resistor 69 connected between its input and its output terminal 49. Potentiometers 56 and 58 and amplifier 61, 64 and 67 together with their input and summing impedances comprise the variable control amplifier 26. Potentiometer 56 controls the magnitude of the output signal from amplifier 51 applied to potentiometer 58 and to one input of summing amplifier 67 while potentiometers 56 and 58 together control the magnitude of the output signal from amplifier 51 applied to amplifier 61. By adjusting the arms 57 and 59 of potentiometers 56 and 58 simultaneously and in the same ratio, the bandwidth of the elevation channel is varied directly as a function of the position of these arms while the damping ratio of the elevation channel is maintained constant. When the arms 57, 59 are near the grounded ends of potentiometers 56, 58, the bandwidth of the elevation channel is a minimum. Moving the arms toward the energized end of the potentiometers increases the bandwidth in direct proportion to the displacement of arms 57, 59 from their grounded ends. If only potentiometer 56 were adjusted to vary the bandwidth of the system, the break point at the low frequency end of the transfer characteristic would occur at the same frequency for all settings of the potentiometer. The gain of the system at the break point would, however, vary as a function of the displacement of the arm of potentiometer 56 from its grounded end. By connecting the error signal to amplifier 61 through the second potentiometer 58, the low-frequency break point of the transfer characteristic is made to occur at the same value of gain for all settings of the potentiometer arms thereby maintaining the damping ratio fixed as the bandwidth is varied. In other words, the transfer characteristic is moved parallel to itself along the frequency axis by adjusting potentiometers 56 and 58 together, thereby changing the frequency at which the break point occurs but not the shape of the open-loop gain frequency curve. Limit stops (not shown) are provided on potentiometers 56 and 58 to prevent reduction in bandwidth below a predetermined value. The output of amplifier 51 is also connected through a low-pass filter 72 comprising series resistors 73 and 74 and a capacitor 75 connected between the junction of the resistors and ground. The purpose of the low-pass filter is to smooth the error signal and attenuate the high-frequency noise components so that the bandwidth will be a function of the error signal due to the dynamics of the target course and not a function of the noise in the error signal. The output of low-pass filter 72 is connected to one contact 76 of a chopper 77 having its vibrating arm 78 grounded. The coil 79 of chopper 77 is energized by an alternating voltage source 80. The output of low-pass filter 72, which is modulated by chopper 77, is fed through a capacitor 81 and an A.-C. amplifier 82 to a rectifier 83. Rectifier 83, which may be a voltage doubler or any other suitable type of rectifying device, provides a D.-C. voltage output having a fixed polarity regardless of the polarity of the error signal. The rectifier output voltage is coupled to a smoothing circuit 84 consisting of a capacitor 70 and a resistor 71 and, after modulation by means of chopper contact 76a and arm 78, is fed to an A.-C. servo amplifier 86. Amplifier 86, comprising part of positional servo 85, is coupled to the control winding 87 of a two-phase motor 88 having a reference winding 89 excited from an alternating voltage source 90. Since the bandwidth of the servo is to be a function of the magnitude of the error voltage only and does not depend upon the direction of the error, rectifier 83 is required to provide a uni-directional output. The shaft of tw0-phase motor 88 is coupled by 6 mechanical connection 91 to the arms of potentiometers 56 and 58 thereby adjusting the bandwidth of the variable control amplifier 26 in direct proportion to the magnitude of the elevation error voltage. A tachometer 92, provided for stabilization of positional servo 85, is coupled to the shaft of two-phase motor 88 by a mechanical connection 93 and to the input of amplifier 86 through a network comprising resistors I94, 95 and 96, and rectifier 97. The purpose of this network is to permit the bandwidth of the system to be increased more rapidly than it is decreased. Thus, if a target which has been moving .at a relatively constant angular velocity should suddenly accelerate, the bandwidth of the system will be increased quickly and the target will not be lost. If the radar is tracking a rapidly maneuver ing target, however, and the target suddenly assumes a more nearly constant angular velocity, the bandwidth will begin to decrease at a relatively slow rate. An immediate resumption of target maneuvering, therefore, does not require as great an increase in bandwidth as would be necessary if the rate of bandwidth decrease were as high as the rate of increase. When the error signal is increasing in magnitude, servo motor 88 turns in such a direction as to move the arms of potentiometers 56 and 58 away from their grounded terminals. Under these conditions, the polarity of the voltage at terminal 98 of tachometer 92 is positive and current flows through rectifier 97 and resistor 96 to ground. The feedback voltage coupled to the input of amplifier 86 is, therefore, smaller than it would be if rectifier 97 were not conducting and motor 88 will respond more quickly to the error signal. On the other hand, when the magnitude of the error voltage is decreasing and servo motor 88 is turning in the opposite direction thereby moving potentiometers 56 and 58 toward their grounded ends, the polarity of the output voltage of tachometer 92 will be negative. Rectifier 97 will not conduct and the full negative output voltage will be coupled to the input of amplifier 86 thus lowering the speed with which servo motor 88 will reduce the bandwidth of amplifier 26. A negative positional feedback signal is applied to servo amplifier 86 through a potentiometer 99 having one end connected to a voltage source E and the other end grounded. The arm of potentiome ter 99 is coupled to motor 88 through mechanical connection 100 and to the input of amplifier 86 through resistor 101. Before a target has been acquired by the radar, the magnitude of the error voltage will be essentially zero and the system, as thus far described, would be automatically set for minimum bandwidth. It is usually desirable, however, to provide a relatively wide bandwidth when the radar is being used for purposes other than automatic tracking, such as searching for a target. A voltage of fixed amplitude is, therefore, coupled to the input of amplifier 86 through a resistor 102 from potentiometer 103 when an AUTO-MAN. selector switch 104 is placed in the MAN. position. This voltage, which is modulated by chopper 77, causes servo motor 88 to adjust the arms of potentiometers 56 and 58 to achieve the desired bandwidth. With switch 104 in the manual position, capacitor 105 is charged to a voltage determined by the setting of the arm of potentiometer 103 and the magnitude of the potentiometer excitation voltage E. When switch 104 is moved to the AUTO. position for automatic tracking, potentiometer 103 is disconnected and capacitor 105 discharged through resistor 102 thereby minimizing any transient voltages which might otherwise be caused by a sudden change in voltage at the input to amplifier 86. In the embodiment of the invention shown in FIG- URES 1 and 2, the bandwidth of the elevation channel is varied as a direct function of the elevation error voltage by bandwidth adjuster 32, while the bandwidth of the azimuth channel is varied directly with the azimuth error voltage by a second bandwidth adjuster 43. A considerable saving in equipment and a reduction in system complications may be realized by using the system shown in FIG. 3 wherein the elevation and traverse error voltages are added algebraically, and their sum applied to a single positional servo which controls the bandwidth of the elevation and azimuth channels simultaneously. Referring to FIG. 3, the components in the elevation channel are each designated by the same numerals as are used in FIGS. 1 and 2, and the components in the azimuth channels, since they are similar to those in the elevation channel, are designated by identical primed numerals. Since the operation of the preamplifier and variable control amplifiers have already been described in connection with FIGS. 1 and 2, this description will not be repeated here. In this second form of the invention, the output of amplifier 51 is coupled through a low-pass filter 110, comprising resistors 111, 112 and a capacitor 113, to the input of a modulator 114 having a reference voltage supply 114a. Similarly, the output of amplifier 51 is coupled through a low-pass filter 115 comprising resistors 116, 117 and capacitor 118 to the input of modulator 114. Modulator 114 is coupled to rectifier and filter unit 19 providing a smoothed DC. output voltage having a magnitude proportional to the sum of the elevation and. azimuth error voltages. This DC voltage is converted to an alternating voltage in modulator 120, having a reference voltage supply 120a, and applied to an A.C. amplifier 121 which energizes the control winding 122 of two-phase servo motor 123. The shaft of two-phase motor 123 is coupled by mechanical connection 124 to otentiometers 56 and 58 in the elevation channel and by mechanical connection 125 to Potentiometers 56' and 58 in the azimuth channel. Motor 123, having a reference winding 126 excited from an alternating voltage source 127, adjusts the bandwidths of the elevation and azimuth channels simultaneously as a funcion of the sum of the elevation and azimuth error voltages while maintaining the damping ratio of each channel fixed. Negative positional feedback is obtained from potentiometer 123, having a voltage E connected across it, while the arm of potentiometer 128 which is driven by motor 123, is coupled to the input of modulator 129. Stabilization of the bandwidth adjusting servo is obtained by applying the output of tachometer 133, which is coupled to the shaft of two-phase motor 123, to the input of modulator 120. In order to provide a wide system bandwidth when the radar is not tracking a target, the voltage on the arm of a potentiometer 129 may be connected across a capacitor 130 by setting AUTO.-MAN. selector switch 131 to its MAN. position. This voltage is coupled through resistor 132 to the input of modulator 120 to control the setting of potentiometers 56, 56', 58, and 58' by servo motor 123. When switch 131 is set at AUTO., capacitor 130 discharges and the bandwidth of the elevation and azimuth channels is then determined solely by the magnitude of the composite error signal. One of the significant features of the invention is that it automatically adjusts the radar system for optimum tracking as a function of target maneuvers relative to the radar antenna. Minimum bandwidth, and hence maximum noise attenuation, is maintained for targets having a low angular acceleration, the bandwidth being automatically expanded as the angular acceleration of the target increases. The maximum bandwidth is limited to a value below that which will result in unstable scanner oscillations while the minimum bandwidth is kept wide enough to maintain tracking of targets having a constant angular acceleration with little or no error. In addition, the damping ratios of the elevation and azimuth channel servos are maintained constant as the bandwidth is varied thus assuring optimum tracking over the entire bandwidth range. As many changes could be made in the above construction and many different embodiments could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. What is claimed is: 1. A control system for positioning an output member in accordance with an applied input signal comprising error signal means responsive to the position of said output member and to said applied input signal, variable control amplifying means coupled to said error signal means and to said output member, low-pass filter means coupled to said error signal means, and bandwidth ad justing means coupled to said low-pass filter means and to said variable control amplifying means, said bandwidth adjusting means varying the response of said amplifying means in accordance with the magnitude of said error signal means. 2. In a feedback control system including an error signal source, amplifying means coupled to said error signal source, and movable output means connected to said amplifying means, the combination comprising bandwidth adjusting means coupled to said error signal source and to said amplifying means, said bandwidth adjusting means varying the response of said amplifying means in accordance with the magnitude of said error signal source, and means coupled from said bandwidth adjusting means to said amplifying means for maintaining the damping ratio of said feedback control system constant with changes in bandwidth. 3. In a feedback control system including an error signal source, amplifying means coupled to said error signal source and output means coupled to said amplify- .ing means, the combination comprising low-pass filter means coupled to said error signal source, rectification means coupled to said low-pass filter means, and servo control means coupled to said rectification means and to said amplifying means, said servo control means varying the bandwidth of said amplifying means as a function of the magnitude of the output of said error signal source and maintaining the damping ratio of said feedback control system constant with changes in bandwidth. 4. In a feedback control system including an error signal source and movable output means, the combination comprising potentiometer means coupled to said error signal source, amplifying means coupling said potentiometer means to said movable output means, and bandwidth adjusting means coupled to said error signal source and to said potentiometer means, said bandwidth adjusting means varying the setting of said potentiometer means in accordance with the output of said error signal source. 5. A feedback control system as defined in claim 4 wherein said bandwidth adjusting means includes positional servo means responsive to the magnitude of said error signal source, said positional servo means setting said potentiometer means in accordance with the magnitude of the output of said error signal source. 6. A feedback control system as defined in claim 4 wherein said amplifying means includes a direct channel, an integrating channel, summing means, and means coupling the outputs of said direct and integrating channels to the input of said summing means, and wherein said potentiometer means includes first and second potentiometers, said first potentiometer varying the input signal to said direct channel and said second potentiometer varying the input signal to said integrating channel. 7. In a feedback control system including an error signal source and controllable output means, the combination comprising amplifying means having first and second channels and means coupling the outputs of said first and second channels to said output means; first and second potentiometers each having a fixed element and a movable element, said first potentiometer coupling said error signal source to said first channel and said second potentiometer coupling said error signal source to said second channel, and bandwidth adjusting means coupled to said error signal source, said bandwidth adjusting means including a servo motor responsive to the magnitude of said error signal source coupled to the movable elements of said first and second otentiometers. 8. In a feedback control system having a movable output member, the combination comprising amplifying means coupled to said output member and adapted to receive an applied error signal voltage, means coupled to said amplifying means for varying the bandwidth thereof in accordance with an applied input signal, and means coupled to said amplifying means for maintaining the damping ratio of said fedback control system constant with changes in bandwidth. 9. A feedback control system as defined in claim 8 wherein the magnitude of the input signal applied to said means for varying the bandwidth of said amplifying means corresponds to the magnitude of said applied error signal voltage. 10. A positional control system for controlling a movable object in accordance with an applied error signal comprising amplifying means including a direct channel, an integrating channel, and means coupling the outputs of said direct and integrating channels to said movable object; a first potentiometer having its fixed element adapted to receive said applied error signal and its movable element connected to said direct channel; a second potentiometer having its fixed element connected to the movable element of said first potentiometer and having its movable element connected to said integrating channel; and bandwidth adjusting means adapted to receive said applied error signal, said bandwidth adjusting means including motor means mechanically coupled to the movable elements of said first and second potentiometers, each of said movable elements being displaced in direct proportion to the magnitude of said applied error signal. L1. An automatic tracking system comprising an antenna mounted for movement in elevation and azimuth, receiver means connected to said antenna for supplying signal voltages proportional to the elevation and azimuth components of the angular error between the directive axis of said antenna and the direction to a distant target, elevation amplifying means connected to said receiver means to receive the elevation component of error voltage, means coupled to said elevation amplifying means .and to said antenna for driving said antenna in elevation, azimuth amplifying means connected to said receiver means to receive the azimuth components of error voltage, means coupled to said azimuth amplifying means and to said antenna for driving said antenna in azimuth, first and second bandwidth adjusting means connected to said receiver means, said first bandwidth adjusting means being coupled to said elevation amplifying means for adjusting the response of said elevation amplifying means in accordance with the magnitude of the elevation component of error voltage and maintaining the damping ratio of the elevation channel constant, and said second bandwidth adjusting means being coupled to said azimuth amplifying means for adjusting the response of said azimuth amplifying means in accordance with the magnitude of the azimuth component of error voltage and maintaining the damping ratio of the azimuth channel constant. 12. An automatic tracking system as defined in claim 11 wherein said system includes means for manually adjusting the response of said elevation and azimuth amplifying means when said system is not tracking a target. 1-3. An automatic tracking system comprising an antenna mounted for movement in elevation and azimuth, receiver means connected to said antenna for supplying signal voltages proportional to the elevation and azimuth ll) components of the angular error between the directive axis of said antenna and the direction to a distant target, elevation amplifying means connected to said receiver means to receive the elevation component of error voltage, means coupled to said elevation amplifying means and to said antenna for driving said antenna in elevation, azimuth amplifying means connected to said receiver means to receive the azimuth component of error voltage, means coupled to said azimuth amplifying means and to said antenna for driving said antenna in azimuth, and bandwidth adjusting means connected to said receiver to receive the sum of the elevation and azimuth components of error voltage, said bandwidth adjusting means being coupled to said elevation and azimuth amplifying means for varying the bandwidth thereof in accordance with the sum of said elevation and azimuth components of the error voltage. 1 In a radio tracking system including an antenna and a receiver connected to said antenna, said receiver producing an output voltage including a signal component and a noise component, the combination com-prising amplifier means coupled to said receiver, means coupled to said amplifier means and to said antenna for positioning said antenna, filter means coupled to said receiver for separating said signal component from said noise component, and control means responsive to said signal component coupled to said filter means and to said amplifying means, said control means adjusting the bandwidth of said amplifying means in accordance with said signal component. '15. In a radio tracking system including an antenna and a receiver connected to said antenna, said receiver producing an output voltage comprised of a band of frequency components, the combination comprising amplifier means coupled to said receiver, means coupled to said amplifier means and to said antenna for positioning said antenna, filter means coupled to said receiver, rectifier means coupled to the output of said filter means, and control means coupled to the output of said rectifier means and to said amplifying means for adjusting the bandwidth of said amplifying means and maintaining the damping ratio of said radio tracking system constant. 16. In a radio tracking system including an antenna and a receiver connected to said antenna, said receiver producing an output voltage comprised of a band of frequency components, the combination comprising amplifier means coupled to said receiver, said amplifier means including potentiometer means for varying the bandwidth of said amplifier means, means coupled to said amplifier means and to said antenna for positioning said antenna, filter means coupled to said receiver, rectifier means couple-d to the output of said filter means, and positional servo means having a servo amplifier coupled to the output of said rectifier means and a servo motor connected to said servo amplifier, said servo motor having its output shaft coupled to said potentiometer means thereby varying the bandwidth of said amplifier means in direct proportion to the output of said rectifier means. 17. A radio tracking system as defined in claim 16 wherein said positional servo means includes non-linear circuit means for driving said servo motor at a higher speed when the output of said rectifier means is increasing in magnitude than when it is decreasing in magnitude. References Cited by the Examiner UNITED STATES PATENTS 2,647,258 7/53 McCoy 318-448 2,698,932 1/55 Wathen 3437.4 2,704,490 3/55 Hammond 343-117 2,760,131 8/56 Br-aunagel 318-28 2,784,402 3/57 White et a1. 3437.4 2,880,384 3/59 Surtees 24477 CHESTER L. IUSTUS, Primary Examiner. 2. IN A FEEDBACK CONTROL SYSTEM INCLUDING AN ERROR SIGNAL SOURCE, AMPLIFYING MEANS COUPLED TO SAID ERROR SIGNAL SOURCE, AND MOVABLE OUTPUT MEANS CONNECTED TO SAID AMPLIFYING MEANS, THE COMBINATION COMPRISING BANDWIDTH ADJUSTING MEANS C OUPLED TO SLAID ERROR SIGNAL SOURCE AND TO SAID AMPLIFYING MEANS, SID BANDWIDTH ADJUSTING MEANS VARYING THE RESPONSE OF SAID AMPLIFYING MEANS IN ACCORDANCE WITH THE MAGNITUDE OF SAID ERROR SIGNAL SOURCE, AND MEANS COUPLED FROM SAID BANDWIDTH ADJUSTING MEANS TO SAID AMPLIFYING MEANS FOR MAINTAINING THE DAMPING RATIO OF SAID FEEDBACK CONTROL SYSTEM CONSTANT WITH CHANGES IN BANDWIDTH.

1958-12-26

en

1965-09-14

US-5885198-A

Internal thread-producing tool and method ABSTRACT A thread-producing tool for producing an internal thread includes a body forming a rear shank portion and a front cutting portion. Provided in the body is a lubricant storage chamber for storing liquid lubricant which is driven toward the cutting portion through discharge passages under the action of centrifugal force during a thread-cutting operation. BACKGROUND OF THE INVENTION The present invention relates to an internal thread producing tool, which can be either a cutting screw tap or a non-cutting thread former. Conventionally the tool is either of high-speed steel or carbide metal. The invention also pertains to a method of forming an internal thread. Shown in FIG. 1 is a conventional screw tap which is a cutting tool for cutting an internal thread. The tap includes a rear shank 1 for being clamped in a tool support, and a front thread cutting part, the so-called chamfer a, consisting of screw turns. The chamfer is arranged on the free end of the tool and is interrupted by longitudinal grooves for chip removal. Disposed rearwardly of the chamfer is the so-called guide or guide part b, which also consists of screw turns interrupted by grooves for chips. The guide part does not perform any cutting work, however, but serves, as the name implies, for the guiding and the uniform driving of the screw tap through the hole to be tapped. Tools producing internal thread without the use of a guide part have also been proposed recently for rigid tapping, see Swedish Patent Application 9600927-9. In principle there are two basic types of screw taps, namely the bottoming tap (also called blind hole tap) and the straight-through tap. As the names imply, holes open on one side and closed on the other side by a bottom are involved in the first case, while bottomless holes open on both sides are involved in the second case. In the first case the chips have to be conveyed out of the hole, in the opposite axial direction to that of the tapping. The grooves for chips are consequently formed helically in the same direction as the direction of rotation of the tap, whereby they have a chip-conveying effect. Known bottoming taps are described e.g. in DE-U-86 23 509.5, Marburger U.S. Pat. No. 4,462,727 and Von Holst et al. U.S. Pat. No. 5,487,626. In the second case (i.e. with straight-through taps) it is more favorable if the chips are conveyed to the front, through the hole, in the same direction as the tapping direction. In this case, therefore, the grooves for chips are formed helically opposite the direction of rotation of the tap and thereby have the effect of driving the chips towards the tap tip. Examples of straight-through screw taps are described for example in DE-A-3 419 850 and DE-U-83 24 835.8. Also known are screw taps with straight, axially extending grooves for chips, which in principle convey the chips neither to the front nor to the rear. These are particularly suitable with short-chipping material and with small thread depths. Three different types of taps with straight-line grooves are often employed, namely, a taper tap, a second tap and a plug tap. Unlike the screw tap, thread formers do not produce any chips; they simply deform the material. With thread formers also it is the practice to speak of a "chamfer" and a guide part, although the term chamfer is strictly speaking incorrect, since thread formers do not cut. For the sake of simplicity, however, this expression will also be used here for describing the tapering front part, in which, as in the case of screw taps, the work (albeit deforming work) for producing the thread is performed. A thread former according to the state of the art is described, for example, in DE-A-2 414 635. It is normal to use considerable amounts of coolants and lubricants when operating the thread-producing tools described above. In recent times, however, a strong trend in general towards dry machining can be noted, not only in the production of thread but also, or even in particular, in turning, drilling and milling. The main reasons for this are to save on the costs of cooling lubricants and to protect the environment. Various machining processes can be converted to dry chipping relatively easily. The latter include, e.g.,turning and milling. Other processes present far greater problems when they are carried out dry screw tapping and thread forming are particularly problematical. In such cases the so-called minimal lubrication technique is often used as a possible solution wherein minimal lubricant is fed via nozzles from the outside or centrally through the spindle and the tool. It is therefore often necessary for the screw tapping process (or thread forming process), to install a minimal lubrication system on the machine. This naturally complicates the machine and makes it more expensive. The invention is consequently based on the aim of saving on cooling lubricant costs and protecting the environment. It is further an object of the invention to avoid the need for the installation of a minimal lubrication system on a thread-producing machine. SUMMARY OF THE INVENTION These and other objects clear to the skilled artisan are achieved by the present invention, in which a thread-producing tool comprises a body having a rear shank portion and a front thread-forming portion. The body includes a lubricant chamber disposed therein for storing liquid lubricant. The chamber includes at least one lubricant discharge passage extending from the chamber to the front thread-cutting portion for discharging liquid lubricant. The invention also relates to a method of producing an internal thread in a workpiece which comprises the steps of: A) providing a tool formed by a body having a rear shank portion, a front thread-forming, and a lubricant chamber formed in the body communicating with the thread-forming portion by at least one discharge passage; B) storing liquid lubricant in the chamber; and C) rotating the tool during a thread-forming operation wherein the liquid lubricant is displaced through the discharge passage under the action of centrifugal force. BRIEF DESCRIPTION OF THE DRAWING The invention will now be described in detail below by means of embodiments shown in the drawings, wherein: FIG. 1 shows a conventional spirally grooved screw tap, FIG. 2 a longitudinal section of a screw tap according to a first embodiment of the invention, FIG. 3 a longitudinal section of a screw tap according to a second embodiment of the invention, and FIG. 4 a longitudinal section of a screw tap according to a third embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION As shown in FIG. 1, a commonly used bottoming screw tap incorporates a shank 1 and a square 2, which is disposed on the shank 1 for the transmission of a turning moment in a case. Extending forwardly from the shank is a taper-shaped neck 3, and extending forwardly from the neck 3 is a screw head 4. The head 4 and the neck 3 are provided with for example three equidistant, helical grooves 5 for chip removal. The operative front end of the tool is normally provided with a conical tip 6, which has no function, but is there only on manufacturing grounds. As already mentioned above, the screw head of the commonly used screw tap (and also the commonly used thread former) incorporates a chamfer a and a guide part b. As can be seen from all the figures, the chamfer a tapers substantially uniformly to the front. Whereas the whole of the chipping takes place in the chamfer area a, the guide part b serves merely for the axial guiding of the tool in the already produced thread. According to the above-mentioned SE-A-9600927-9 the guide part b can be omitted for rigid screw tapping ("rigid tapping"). In order to achieve the aims mentioned earlier, a minimal lubricant chamber is formed in the thread-producing tool according to the invention, wherein the lubricant is conveyed via fine bores at least aided by centrifugal force occurring during the machining, without there occurring an additional external effect on the tool cutting edges. Moreover, no coolant is supplied from the outside during the whole period of use, the lubricant from the chamber takes over this function. According to the embodiment in FIG. 2 a minimal lubricant chamber 7 is located in the screw head. The chamber 7 comprises a bore which extends to the front or distal end of the tool. The front end of the bore can be widened slightly and accommodate a closure 8. In so doing the conical tip 6 of FIG. 1 has preferably been eliminated. The nature of the closure 8 is not material to the invention, but it could, for instance, comprise an externally threaded screw, or a pin which is glued or pressed-in. The use of a soft pin of light metal such as aluminum is also conceivable, which is heat-sealed during the pressing in. Blind rivets could also be used. Disposed obliquely (or alternatively directly radially) outwards from the chamber 7 are feed bores or discharge passages 9 for feeding the lubricant to the chipping point, i.e. to the chamfer, and optionally also to the guide part. The necessary bore diameter of said feed bores depends on the viscosity of the minimal lubricant and lies in general in the range between 0.01 and 0.4 mm, preferably between 0.05 and 0.2 mm. The number of feed bores is not critical and can be e.g. from two to eight. Up to approximately 0.2 mm diameter the feed bores are normally manufactured by erosion; below 0.2 mm by laser drilling. Both methods can be used both for high-speed steel and for carbide metal. The required amount of minimal lubricant is extremely small and normally lies between 1 and 20 ml per hour. In view of these very small amounts which are provided, a minimal lubricant with particularly good SPRITE affect (i.e., the property of the minimal lubricant to spread and distribute itself very rapidly on the surface of the tool and of the workpiece) is required. The use of simply any cutting oil, such as were known previously, is therefore not preferred, but special minimal lubricants, such as are conventional, are employed. According to the embodiment shown in FIG. 3 the chamber 7' is longer, i.e., it is continuous, from the distal end of the tool up to the shank end. In order to be able to accommodate more lubricant, the bore can have a greater diameter in the shank than in the front part, see bore part 11. The rear end of the chamber bore can also be sealed by means of a closure (see closure 12), in the same way as the front end. According to the embodiment in FIG. 4 the lubricant can be urged forwardly of the discharge passages by means of a plunger 13 and a spring 14. The spring 14 is moreover located between the axially movable plunger 13 and the end closure 12'. Due to the integral lubricant chamber the screw tapping can also be performed in difficult materials without the use of expensive minimal lubrication devices and without additional lubrication from outside. In addition it is guaranteed that the lubricant comes out only when the tool rotates. Consequently only very small amounts are needed. Tests have shown that a lubricant volume of about 5 ml suffices for the whole life of a screw tap of the size M8 for the machining of heat treatable steel. The life of such a screw tap is about 90 minutes. It should be clear that the outer geometry of the tool producing thread is immaterial to the inventive idea. Consequently the minimal lubricant chamber according to the invention can be used for any screw tap and any thread former. Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims. What is claimed is: 1. An internal thread-producing tool, comprising a body having a rear shank portion and a front thread-forming portion, the body including a lubricant chamber disposed therein for storing liquid lubricant, the chamber including at least one lubricant discharge passage extending from the chamber to the thread-forming portion for discharging liquid lubricant, wherein the lubricant chamber has at least two different diameters over an axial length of the lubricant chamber. 2. The tool according to claim 1, wherein the chamber contains a minimal liquid lubricant. 3. An internal thread-producing tool, comprising a body having a rear shank portion and a front thread-forming portion, the body including a lubricant chamber disposed therein for storing liquid lubricant, the chamber including at least one lubricant discharge passage extending from the chamber to the thread-forming portion for discharging liquid lubricant, wherein the discharge passage has a diameter in the range of about 0.01 to 0.4 mm. 4. The tool according to claim 1, wherein the chamber extends along a center axis of the body. 5. The tool according to claim 4 wherein the chamber extends rearwardly from a front end of the body, a front end of the chamber being sealed by a closure. 6. An internal thread-producing tool, comprising a body having a rear shank portion and a front thread-forming portion, the body including a lubricant chamber disposed therein for storing liquid lubricant, the chamber including at least one lubricant discharge passage extending from the chamber to the thread-forming portion for discharging liquid lubricant, wherein the chamber also extends to a rear end of the body, a rear end of the chamber being sealed by a closure. 7. An internal thread-producing tool, comprising a body having a rear shank portion and a front thread-forming portion, the body including a lubricant chamber disposed therein for storing liquid lubricant, the chamber including at least one lubricant discharge passage extending from the chamber to the thread-forming portion for discharging liquid lubricant, further including a plunger disposed in the chamber and being forwardly spring-biased to urge liquid forwardly toward the discharge passage. 8. An internal thread-producing tool as set forth in claim 1, wherein the chamber includes at least two lubricant discharge passages extending from the chamber to the thread-forming portion for discharging liquid lubricant, the at least two discharge passages extending from the lubricant chamber at different angles relative to the chamber. 9. An internal thread-producing tool, comprising a body having a rear shank portion and a front thread-forming portion, the body including a lubricant chamber disposed therein for storing liquid lubricant, the chamber including at least one lubricant discharge passage extending from the chamber to the thread-forming portion for discharging liquid lubricant, wherein the chamber extends along a center axis of the body, the chamber extends rearwardly from a front end of the body, a front end of the chamber being sealed by a closure, and the chamber also extends to a rear end of the body, a rear end of the chamber being sealed by a closure.

1998-04-13

en

1999-11-30

US-97752892-A

Chair accessible toilet facility ABSTRACT A footrest for use by a person seated in a wheel-chair facing a toilet facility includes an upper surface capable of accepting a foot thereon and slanting downwardly generally towards the front of the toilet facility. The footrest also includes a lip attached to the upper surface for retaining the foot on the upper surface at a fixed location. TECHNICAL FIELD The present invention relates generally to toilet facilities, and more particularly to footrests for use in conjunction with a toilet. BACKGROUND ART Although restroom facilities have been modified for use by physically disabled persons with, for example, the addition of bars, rails and wider stalls, there is still a certain group of persons, namely, persons confined to wheelchairs, for whom restrooms remain difficult if not impossible to use. These persons usually wear leg bags into which they discharge their urine. A leg bag is normally attached to a shin or calf area of the user's legs and must be periodically emptied into a toilet facility which is typically done while the user is seated in the wheelchair facing the toilet facility. It is difficult, however, for persons confined to wheelchairs to empty their leg bags in present toilet facilities because the leg bag must be placed in close proximity to a rim of the toilet in order to be emptied. At the present time, persons confined to wheelchairs who use leg bags accomplish this act by lifting their legs and resting them on a rim of the toilet facility. However, because toilets are usually made of porcelain or other slick materials and because these persons do not have muscle control in their legs, the leg frequently slips off the toilet rim thereby causing an unsanitary condition. Thus, there is an urgent need for a foot and heel support system which will allow a person seated facing a toilet facility to place his or her foot on a footrest adjacent to the toilet facility and to eliminate the contents of a leg bag while the foot is supported in a stable and comfortable position. Toilet facilities having footrests are known in the prior art. For example, Romer, U.S. Pat. No. 1,798,632 discloses a toilet facility having a U-shaped footrest resting on a floor and slanting downward towards the rear of a toilet to enable a person to assume the squatting position while using the toilet facility. Likewise, Catchings, U.S. Pat. No. 1,155,885; Finlay, U.S. Pat. No. 2,250,060 and Kristoffersen, U.S. Pat. No. 4,012,797 discloses toilet facilities having substantially flat footrests positioned on either side of a toilet to enable a person to assume the squatting position while using the toilet. Moulder, U.S. Pat. No. 1,972,233 discloses a toilet facility having multiple seats and a flat footrest to enable use of the facility by smaller children. Griffith, U.S. Pat. No. 1,668,242 discloses a toilet device having a footrest which moves a person seated in a wheelchair on to a toilet facility to enable use of that facility. Bruzenak, U.S. Pat. No. 2,182,979 discloses a toilet facility including handrails which facilitates use of the facility in the squatting position. None of these prior art references, however, discloses a footrest adapted to be used by a person while seated in a chair facing the toilet facility or a footrest that allows a person to empty a leg bag from a seated position in front of the toilet facility with a foot located in a stable and comfortable position. SUMMARY OF THE INVENTION These disadvantages are substantially overcome by the present invention. Thus, in accordance with one aspect of the present invention, an apparatus for supporting a foot in relation to a toilet facility including a toilet having a front and located above a floor comprises a supporting means for supporting a foot above the floor in proximity to the toilet. The supporting means includes an upper surface capable of accepting a foot thereon and slanting downwardly generally towards the front of the toilet facility. The apparatus further includes retaining means for retaining the foot on the supporting means at a fixed location. Preferably, the retaining means includes a lip connected to, and extending above, at least a portion of the upper surface for holding the foot securely on the upper surface at a fixed height. The retaining means may also include a high friction coefficient material attached to the upper surface for holding the foot on the upper surface. Preferably, the supporting means includes a support member connecting the upper surface to the floor thereby transferring the weight of a foot from the upper surface to the floor. The supporting means may support a foot at a height above the floor approximately equal to the height of a rim of the toilet or, in the alternative, at a height greater than or less than the height of the rim of the toilet. Alternatively, the supporting means and the retaining means may be integrally formed with the toilet. In an alternative embodiment, the supporting means includes first and second supporting means located adjacent to but on opposite sides of the toilet for supporting a foot above the floor in proximity to the toilet. In this embodiment, first and second retaining means retain the foot on the first and second supporting means, respectively, at fixed locations. Preferably, the first and second supporting means include first and second upper surfaces, respectively, slanting downwardly generally toward the front of the toilet facility. In still a further alternative embodiment, the supporting means includes connecting means for connecting the upper surface to a wall adjacent the toilet facility and may include a support member connected to the upper surface having a fastener extending therethrough for connection into the wall. In this embodiment, the upper surface may extend into a hole in the wall when the support member is connected to the wall. In a further aspect of the present invention, an improvement in a toilet facility having a toilet located above a floor comprises a supporting means for supporting a foot of a person seated in a chair facing the toilet, the supporting means supporting the foot at a height above the floor so as to enable the person to empty the contents of a waste collection bag attached to a leg of the person. The improvement also includes retaining means attached to the supporting means for retaining the foot on the supporting means. Preferably, the supporting means includes an upper surface slanting downwardly generally towards the front of the toilet facility and the retaining means includes a lip attached to the upper surface for holding the foot on the upper surface at a predetermined height. In alternative embodiments, the retaining means may include an upper surface slanting downwardly generally towards the toilet or may include a ledge attached to the toilet having an indentation formed therein for holding a foot on the ledge. In still another aspect of this invention, a toilet facility comprises a toilet and a footrest. Preferably the footrest includes an upper surface slanting downwardly generally towards the front of the toilet for accepting a foot such that a toe of the foot is positioned above a heel of the foot, and a retainer extends above at least a portion of the upper surface for holding a foot at a fixed location with respect to the upper surface. Also preferably, the footrest is connected to the toilet or, in an alternative embodiment, the footrest is integrally formed with the toilet or, in still another alternative embodiment, the toilet facility includes a supporting means for supporting the toilet and the footrest. BRIEF DESCRIPTION OF THE DRAWING These and other features and advantages will become more apparent from a detailed consideration of the invention when taken in conjunction with the drawing, in which: FIG. 1 is a side view of the toilet facility footrest of the present invention; FIG. 2 is a side view of a second embodiment of the footrest of the present invention; FIG. 3 is a front view of a double footrest embodiment of the present invention; FIG. 4 is a side view of a wall-mounted embodiment of the footrest of the present invention; FIG. 5 is a side view of a second wall-mounted embodiment of the footrest of the present invention; FIG. 6 is a front view of a third wall-mounted embodiment of the footrest of the present invention; FIG. 7 is a front view of a fourth wall-mounted embodiment of the footrest of the present invention; FIG. 8 is a perspective view of an embodiment of the footrest wherein the footrest is integrally formed with a toilet; FIG. 9 is a perspective view of a further embodiment of the footrest wherein the footrest is integrally formed with the toilet; and FIG. 10 is a perspective view of a still further embodiment of the footrest wherein the footrest is integrally formed with the toilet. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a side view of a footrest 10 according to the present invention including a plate 12 having an upper surface 14. Typically the upper surface 14 is flat and slants downwardly generally towards the front of the footrest 10 and away from a wall 15 as shown in FIG. 1. The footrest 10 also includes a lip 16 which connects to a lower portion of the plate 12 and preferably extends substantially perpendicular to, and above at least a portion of the upper surface 14. The lip 16 may, however, extend above a portion of the upper surface 14 in a substantially perpendicular to, and above at least manner other than perpendicularly. A bar 18 supports the plate 12 and the lip 16 and connects through a fixture 20 to a floor 22. The bar 18 in conjunction with the fixture 20 transfers the weight of objects placed on the plate 12 to the floor 22. Fixture 20 is fastened to the floor in a suitable manner, for example, with bolts or glue. The footrest 10 is located adjacent a toilet 30 such that the plate 12 is located at a height approximately equal to the height of a rim 32 of the toilet 30. However, the plate 12 can be located at a height either greater than or less than the height of the rim 32, wherein this position is determined primarily by user comfort considerations. In use, a person 40 seated in, for example, a wheelchair 42, places a foot 44 on the footrest 10 such that a sole of the foot 44 rests on the upper surface 14 of the plate 12 and a heel of the foot presses against the lip 16. In this manner, the foot 44 is supported at a predetermined height on the footrest 10 with the heel of the foot 44 resting at a location below a toe of the foot. With the foot 44 placed on the footrest 10, as shown in FIG. 1, the person 40 can utilize gravity to empty the contents of a leg bag 46 from, for example, an outlet 48 existing therein, into the toilet 30 while the foot 44 remains in a fixed and comfortable position at a location adjacent the toilet 30. In this manner, the footrest 10 reduces the risk of spillage of the contents of the leg bag 46 during emptying thereof. An alternative embodiment of the present invention is shown in FIG. 2. In this embodiment, a plate 212 and a lip 216 are connected to a toilet 230 at a predetermined vertical height which is below a rim 232 of the toilet 230. Preferably, the plate 212 and the lip 216 are integrally formed with the toilet 230 and, as such, are made of the same material, for example, porcelain, as the toilet 230. In this embodiment, the toilet 230 in conjunction with the plate 212 act as a supporting means for the footrest which is used in the same manner as described in conjunction with the embodiment of FIG. 1. A front view of an alternative embodiment of the invention is shown in FIG. 3 which includes a footrest 310 having plates and 312b and lips 316a and 316b on opposite sides of a toilet 330. The plates 312a and 312b and the lips 316a and 316b are supported by a U-shaped support bar 350 connected to a floor 322 through a second support bar 352. The support bars 350 and 352 are preferably made of metal; however, they can be made of any other suitable material. Strips of high friction coefficient material 354 are located on the surfaces 314a and 314b of the plates 312a and 312b, respectively, and further serve to retain a foot on the plates 312a and 312b when the sole of the foot comes into contact with the high friction coefficient material 354. It should be noted that the high friction coefficient material 354 can be placed in any suitable pattern or design on the upper surfaces 314a and 314b of the plates 312a and 312b. The high friction coefficient material 354 can also be used in conjunction with all the embodiments of the invention disclosed herein, and are only mentioned with reference to FIG. 3 for the sake of simplicity. With this embodiment, a person seated in a chair facing the toilet 330 can place either or both feet on the plates 312a and 312b of the footrest 310. FIG. 4 shows a side view of a wall-mounted embodiment of the footrest used in conjunction with a urinal 430 having a rim 431. In this embodiment, a support plate 456 lies adjacent a wall 458 and connects to an upper end of a plate 412 having a lip 416 attached thereto such that the support plate 456 extends below a portion of the plate 412. Fasteners 460 extend through the support plate 456 and into the wall 458 for holding the support plate 456 in a rigid position. In this manner, the plate 412 and the lip 416 are supported by the wall 458 at a predetermined height and location with respect to the urinal 430. Preferably, the plate 412 and lip 416 are located at a height substantially equal to the rim 431 of the urinal 430. FIG. 5 shows a side view of a wall-mounted embodiment of the present invention wherein a support plate 556 connects to a wall 558 and supports a plate 512 and a lip 516 adjacent a toilet 530 in a manner similar to that described in conjunction with FIG. 4. In this embodiment, however, the support plate 556 connects to the plate 512 through a support member 517 and extends vertically above the plate 512. FIG. 6 shows an alternate embodiment of a wall-mounted footrest of the present invention wherein a support bar 664 and a support plate 666 are attached to a side wall 668 in any conventional manner and laterally support a plate 612 and a lip 616 adjacent a toilet 630. Preferably, the plate 612 is located at a height approximately equal to a rim 632 of the toilet 630; however, as with all the embodiments of this invention, the plate 612 and the lip 616 can be supported at any vertical height. FIG. 7 shows a front view of an embodiment of the invention used in conjunction with a urinal. In this embodiment, U-shaped fastening plates 770, having fasteners 772 extending therethrough into a wall 774, support plates 712 and lips 716 adjacent a urinal 776 such that the plates 712 are supported at a vertical height approximately equal to the height of a rim 778 of the urinal 776. In this embodiment, the plates 712 may extend into recesses of the wall 774 such that the lips 716 are located approximately even with the wall 774. FIG. 8 shows a perspective view of a toilet facility having a footrest 810 integrally formed with a toilet 830. As such, the footrest 810 is made of the same material as the toilet 830 and may, therefore, be formed in the same molding process as the toilet 830. A foot 811, shown in phantom line, rests on the foot rest 810 as indicated in FIG. 8. The footrest 810 includes an upper surface 812 slanting downwardly generally towards the front of a toilet facility. A retainer 816, for example, a lip, is attached to the plate 812 and preferably is attached to a side 833 of the toilet 830. For ease in normal use of the toilet 830, the upper surface 812 extends to the same height as a rim 832 of the toilet 830. The lip 816 may be positioned at any height below the rim 832 with the exact position being determined by ease of use of the footrest in emptying a leg bag. In this embodiment, the surface 812 and the retainer 816 act as retaining means while the toilet 830 acts as a supporting means. FIG. 9 shows a perspective view of a toilet facility having a footrest 910 integrally formed with a toilet 930. A ledge 980 extends out from a rim 932 of the toilet 930. An indentation 982 is formed within the ledge 980 such that an upper surface 984 slants generally downward toward the rear of the toilet facility. A wall 986 extends downward from the ledge 980 to a lower portion of the upper surface 984. In use, a person places a foot on the footrest 910 so that a heel on the foot rests on the upper surface 984 and a bottom of the foot comes into contact with the wall 986. In such a manner, the foot will be supported by the footrest 910 at a fixed location with respect to the rim 932 of the toilet 930. FIG. 10 shows a perspective view of an alternative embodiment of the invention having a footrest 1010 integrally formed with the toilet 1030 at a location below a rim 1032 of the toilet 1030. In this embodiment, the footrest 1010 has an upper surface 1013 slanting downwardly generally towards the toilet 1030 thereby defining a space directly between the upper surface 1013 and a side 1033 of the toilet 1030. In use, a person places a foot in the space between the side 1033 of the toilet 1030 and the upper surface 1013, such that the heal of the foot comes into contact with both the upper surface 1013 and the side 1033 of the toilet 1030. In this manner, the foot will be supported at a predetermined height with respect to the toilet 1030. It should be noted that the footrest of the present invention may include Only the plate 12 having an upper surface 14 and the high friction coefficient material 354 attached thereto. It should also be noted that either a single or double footrest version of the invention can be used in any of the embodiments of the footrest disclosed herein and that any of the embodiments of the footrest 10 disclosed herein can be used in conjunction with any toilet facility, including a toilet, a urinal and any other defecation or urination apparatus. The term "toilet," as used herein, includes what is commonly referred to as a urinal. Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which come within the scope of the appended claims is reserved. We claim: 1. A toilet facility comprising:a toilet adapted to be located above a floor and having a front portion and a back portion; supporting means for supporting a foot of a person above the floor in proximity to the toilet, the supporting means, being positioned laterally of the toilet and including an upper surface capable of accepting the foot thereon and slanting downwardly generally towards the front portion and away from the back portion of the toilet, to support the toes of the foot above the heel of the foot; and retaining means for retaining the foot on the supporting means at a fixed location, the retaining means including a lip structure connected to and extending above at least a portion of the upper surface for engaging the back of the heel of the foot when the foot is supported on the upper surface. 2. The toilet facility as recited in claim 1 wherein said retaining means retains the foot on the supporting means at a fixed location with the heel of the foot being retained closer to the front of the toilet than the toes of the foot. 3. The toilet facility of claim 2 wherein the supporting means and the retaining means are integrally formed with the toilet. 4. The toilet facility of claim 2 wherein the supporting means includes a support member adapted to connect the upper surface to the floor for transferring the weight of a foot from the upper surface to the floor. 5. The toilet facility of claim 4 wherein the retaining means includes a non-slip material attached to the upper surface. 6. The toilet facility of claim 4 wherein the supporting means supports the foot at a height above the floor approximately equal to the height of a rim of the toilet. 7. The toilet facility of claim 4 wherein the supporting means supports the foot at a height above the floor greater than the height of a rim of the toilet. 8. The toilet facility of claim 2 wherein the supporting means includes second supporting means located on the opposite side of the toilet for supporting a foot above the floor in proximity to the toilet and second retaining means for retaining the foot on the second supporting means, wherein the second supporting means includes second upper surface slanting downwardly gene ally towards the front portion of the toilet facility. 9. The toilet facility of claim 2 wherein the supporting means includes connecting means for connecting the upper surface to a wall adjacent the toilet 10. The toilet facility of claim 9 wherein the connecting means includes a support member, connected to the upper surface, having a fastener extending therethrough for connection into the wall. 11. The toilet facility of claim 10 wherein the upper surface is adapted to extend into a hole in the wall when the support member is connected to the wall. 12. The toilet facility of claim 1 wherein the retaining means includes a non-slip material attached to the upper surface. 13. A toilet facility comprising:a toilet adapted to be located above a floor and having a front portion and a back portion; supporting means for supporting a foot of a person seated in a chair facing the front portion of the toilet, said supporting means being positioned laterally of the toilet and including support surface means disposed near a rim of said toilet and slanting downwardly generally towards the front portion and away from the back portion of the toilet for physically supporting the foot of the person seated in the chair facing said toilet at a height above the floor so as to enable the person to empty the contents of a waste collection bag attached to a leg of the person under the force of gravity into said toilet; and retaining means attached to the supporting means for retaining the foot on the supporting means, the retaining means including foot supporting means for engaging the back of the heel of the foot when the foot is supported on the support surface means. 14. The toilet facility of claim 13 wherein the foot supporting means is located at a height approximately equal to the height of the rim of the toilet. 15. The toilet facility of claim 13 wherein the foot supporting means includes a lip attached to the support surface means for holding the foot on the supporting means. 16. The toilet facility of claim 15 wherein the supporting means includes a support member adapted to connect the support surface means to the floor for transferring the weight of the foot from the support surface means to the floor. 17. A method of facilitating the emptying into a toilet of the contents of a urine bag secured below the knee to a disabled leg of a person in a wheelchair comprising the steps of:positioning the foot of the disabled leg on a footrest disposed near the rim of the toilet such that at least a portion of the foot and the urine bag secured to the disabled leg is disposed above the rim of the toilet, said positioning step including the step of maintaining a heel of the foot securely engaged with said footrest with said heel being disposed on said footrest below any toe of the foot, said positioning step further including said footrest having a slanting upper surface providing for the step of maintaining said foot angularly disposed with respect to said rim of said toilet with the heel of said foot being disposed closer to the front of the toilet when the disposition of any toe of said foot; and utilizing gravity, emptying the contents of the urine bag into the toilet.

1992-11-17

en

1994-02-01

US-58402690-A

Cam unit and sewing machine employing same ABSTRACT A cam unit comprising a main cam; a first auxiliary cam provided in contact with the main cam; a second auxiliary cam provided in contact with the first auxiliary cam; a rod provided between the main cam and the second auxiliary cam and having a slenderly shaped hole in which the peripheral portion of the first auxiliary cam is located in contact with the rod so that the rod is swung while being guided by the first auxiliary cam; a motion transmission means secured to the rod and located on the peripheral portion of the main cam so as to move the rod in accordance with the contour of the main cam; a jump prevention means secured to the rod and located on the peripheral portion of the second auxiliary cam so as to prevent the motion transmission means from jumping from the main cam; and a shaft extending through all the cams. A positive cam is constituted by the main cam, the auxiliary cams and the rod without guiding a driven member to straightly move it. A motion is directly transmitted to a swinging member by the cam unit. BACKGROUND OF THE INVENTION The present invention relates to a cam unit for converting a rotary motion into a reciprocative motion, and also relates to a sewing machine employing the cam unit. FIG. 4 shows the constitution of a conventional differential vertical sewing machine in which a main shaft 1 is supported by bearings 1a and 1b so that the shaft is rotated by a motor not shown in the drawing. The left-hand end of the main shaft 1 is coupled to a needle rod and thread take-up mechanism 12 made of a needle rod 13 and a thread take-up lever 14. The needle rod 13 is guided by bearings 13a and 13b. A flywheel 1c is mounted on the main shaft 1 at the right-hand end thereof. Four eccentric wheels 4, 6, 8 and 10 for causing an upper feed vertical driving force (i), an upper feed horizontal driving force (ii), a lower feed vertical driving force (iii) and a lower feed horizontal driving force (iv), respectively, and a bevel gear 2 for transmitting the torque of the main shaft 1 to a lower shaft 18 are attached to the central portion of the main shaft. The lower shaft 18 is rotatably supported by bearings 18a and 18b. A bevel gear 17 and a shuttle hook 19 are attached to the lower shaft 18 at the right-hand end and left-hand end thereof, respectively. A vertical shaft 15 is supported by bearings 15a and 15b. Bevel gears 3 and 16 are mounted on the vertical shaft 15 a the upper and lower ends thereof, respectively, and engaged with the bevel gears 2 and 17, respectively. An upper feed shaft 38 is rotatably supported by bearings 38a and 38b. The input portion 38i of the upper feed shaft 38 at the right-hand end thereof is coupled to an upper feed quantity controller 20 by a pin 24. The output portion 38o of the shaft 38 at the left-hand end thereof is split into two parts and surrounds a member 39 rotatably supported by the input end portion of a horizontal driving lever 40. An upper feed dog 55 is provided with upper feed teeth 57 at the front end of the dog and is rotatively coupled at the rear end of the dog to the lower end of the horizontal driving lever 40. The two-split front portion of the upper feed dog 55 surrounds a cam follower 50 rotatably supported on a rod 49b at the lower end thereof. The rod 49b is slidably supported by the body 53 of a head. A driving lever 45 is rotatably supported at the central portion thereof. A cam follower 46 is attached to the driving lever 45 at the output portion thereof. The lever 45 is rotatively coupled at the input portion thereof to a rod 5 at the lower end thereof. The rod 5 is rotatively coupled at the upper end thereof to the eccentric wheel 4. An upper feed vertical motion lever 49a shaped as L is rotatably supported by a lifter attaching rod 52 supported by the head body 53 so as to be vertically slidable. The vertical portion of the lever 49a is engaged with the cam follower 46. The horizontal portion of the lever 49a is engaged with the bottom of the upper horizontal portion of the rod 49b. A rod 7 is rotatively coupled at the upper portion thereof to the eccentric wheel 6, and coupled at the lower end portion of the rod to the upper feed quantity controller 20. The controller 20 includes a control lever 25, an auxiliary lever 27 and a coupling lever 28 which are supported to be tunable about the axis of the fixed shaft 21 secured to the head body 53, a pin 22 for rotatively coupling the control lever and the auxiliary lever to each other, a pin 23 for rotatively coupling the auxiliary lever and the coupling lever to the rod 7 at the lower end thereof, and a pin 24 for rotatively coupling the coupling lever to the input portion 38i of the upper feed horizontal motion shaft 38. A lower feed horizontal motion shaft 58 is rotatably supported by bearings 58a and 58b and coupled at the input portion 58i of the shaft to a lower feed quantity controller 29. The output portion 58o of the shaft 58 is rotatively coupled to a feed dog 59 at the rear end thereof. The feed dog 59 has feed teeth 25 on the central part of the portion. The front end portion 59o of the dog 59 is split into two parts. A lower feed vertical motion shaft 62 is rotatably supported by bearings 62a and 62b, and rotatively coupled at the output portion 62o of the shaft to a member 60. The output portion 62o of the shaft 62 is surrounded by the two-split portion of the feed dog 59. The input portion 62i of the shaft 62 is rotatively coupled to a rod 9 at the lower end thereof. The upper portion of the rod 9 is rotatively coupled to the eccentric wheel 8. A rod 11 is rotatively coupled at the upper portion thereof to the eccentric wheel 10 and coupled at the lower end of the rod to the lower feed quantity controller 29. The controller 29 includes a control lever 34, an auxiliary lever 36 and a coupling lever 37 which are supported to be tunable about the axis of the fixed shaft 30 secured to the head body 53, a pin 31 for rotatively coupling the control lever and the auxiliary lever to each other, a pin 32 for rotatively coupling the auxiliary lever and the coupling lever to the road 11 at the lower end thereof, and a pin 33 for coupling the coupling lever to the input portion of the lower feed horizontal motion shaft 58. FIG. 5 shows an enlarged partial view of another conventional differential vertical sewing machine of such kind at and near a lower feed dog 59. The difference of the machine from that shown in FIG. 4 is that a two-split vertical driving lever 63 is secured to a lower feed vertical motion shaft 62 at the tip thereof and surrounds a member 60 rotatably supported by the lower feed dog 59 at the tip thereof. FIG. 6 shows an enlarged partial view of another conventional differential vertical sewing machine at and near a lower feed dog 59. In the machine, a lower feed vertical motion shaft 62 is rotated, as differs from those shown in FIGS. 4 and 5, a cam 63 is secured to the shaft at the tip thereof, a cam follower 60 is attached to the portion of the lower feed dog 59, which is engaged with the cam, and a spring 67 engaged with the body of a head and a spring attaching member 71 provided on the dog at the tip thereof acts to apply an elastic force to prevent the cam follower from jumping from the cam. The operation of the conventional sewing machine shown in FIG. 4 is described from now on. When torque is applied to the main shaft 1 by the motor not shown in the drawing, the shaft is rotated and the torque thereof is transmitted to the sections of the machine trough mechanisms coupled to the shaft. At the left-hand end of the main shaft 1, the vertical motion of the needle rod 13 and that of the thread take-up lever 14 are caused through the needle rod and thread take-up mechanism 12. At the central portion of the main shaft 1, the torque thereof is transmitted to the vertical shaft 15 through the engagement of the bevel gears 2 and 3, and the torque of the vertical shaft is transmitted to the lower shaft 18 through the engagement of the bevel gears 16 and 17 to rotate the shuttle hook 19. The rotation of the eccentric wheel 4 is converted into the vertical motion of the rod 49b through the reciprocative motion of the rod 5, the swing motion of the driving lever 45 and that of the driven lever 49a. The rotation of the eccentric wheel 6 is converted into the reciprocative motion of the rod 7, which causes the swing motion of the upper feed horizontal motion shaft 38 through the upper feed quantity controller 20. The swing motion of the shaft 38 causes that of the horizontal driving lever 40 and the horizontal motion of the upper feed dog 55 through the engagement of the two-split output portion 38o of the shaft and the member 39. Since the two-split front portion of the upper feed dog 55 is engaged with the cam follower 50 rotatively coupled to the lower portion of the rod 49b, the dog performs a vertical motion synchronized with the horizontal motion of the dog, so that the upper feed teeth 57 performs a pseudo-elliptic feed motion. The rotation of the eccentric wheel 8 is converted into the reciprocative motion of the rod 9 and the swing motion of the feed vertical motion shaft 62, and causes the vertical motion of the member 60 rotatively coupled to the output portion 62o of the shaft. The rotation of the eccentric wheel 10 is converted into the reciprocative motion of the rod 11, which causes the swing motion of the lower feed horizontal motion shaft 58 through the lower feed quantity controller 29 so that the horizontal motion of the feed dog 59 coupled to the output portion 58o of the shaft. Since the two-split front portion of the dog 59 is engaged with the member 60, the dog performs a vertical motion synchronized with the horizontal motion thereof, so that feed teeth 75 perform a pseudo-elliptic feed motion. Since it is well known that the above-mentioned motions caused through the rotation of the main shaft 1 are organically synchronized with each other, it is not described in detail herein. The quantity of an upper feed is controlled by swinging the upper feed control lever 25 to change the posture thereof. The quantity of a lower feed is controlled by swinging the lower feed control lever 34 to change the posture thereof. Mechanisms for changing the postures of the control levers 25 and 34 and mechanisms for maintaining the postures are not shown in the drawings. Although lower feed mechanisms shown in FIGS. 4 and 5 differ from each other in the form of the feed dog 59 and that of the vertical driving lever 63, the mechanisms are nearly the same as each other in the operation of each portion thereof. Although the operation of the lower feed horizontal motion shaft 58 of a lower feed mechanism shown in FIG. 6 is the same as that of the lower feed horizontal motion shaft 58 of the lower feed mechanism shown in FIG. 4, the lower feed vertical motion shaft 62 of the mechanism shown in FIG. 6 performs a rotary motion so that the cam 63 mounted on the shaft at the tip thereof is rotated. Since the cam follower 60 mounted on the feed dog 59 at the tip thereof in the lower feed mechanism shown in FIG. 6 is urged by the spring 67 so as to be engaged with the surface of the cam 63, the feed dog performs a vertical motion due to the rotation of the cam. Since the swing motion of the lower feed horizontal motion lever 68 and the rotary motion of the cam 63 in the mechanism shown in FIG. 6 are synchronized with each other as well as those in the mechanism shown in FIG. 4, feed teeth 75 perform a pseudo-elliptic feed motion. FIG. 7 is an enlarged partial view of another conventional differential vertical sewing machine in which a rotary shaft is provided instead of a vertically moving shaft, a cam is mounted on the rotary shaft at the tip thereof, a sliding block is provided to be guided by the body of a head so as to be straightly moved vertically and is engaged with the cam so as to perform the vertical motion, and feed teeth perform a vertical motion due to that of the block. The upper feed mechanism of the sewing machine is described from now on. In the mechanism, timing pulleys 4 and 8 are mounted on the central portion of a main shaft 1, a member 39 is rotatively coupled to the input end of a horizontal driving lever 40 and engaged with the two-split output portion 38o of an upper feed horizontal motion shaft 38, and a guide 41 provided at the output end of the shaft guides a driven lever 49 to move the lever straightly. A timing pulley 42 is mounted on the input portion of an upper feed vertical motion shaft 43 rotatably supported by bearings 43a and 43b, and is coupled to the timing pulley 4 by a timing belt 5. A cam 44 is mounted on the upper feed vertical motion shaft 43 at the output end thereof. A slider 45 is straightly moved vertically while being guided by a linear guide 48 secured to the head body 53. A cam follower 46 is attached to the upper arm of the slider 45 and engaged with the cam 44 by the elastic force of a spring 47. The slider is restricted by a means not shown in FIG. 7, so that the slider does not rotate about the axis of the straight motion thereof. The driven lever 49 is guided by the guide 41 at the output end of the horizontal driving lever 40. A cam follower 50 is attached to the driven lever 49 at the upper end thereof and engaged with the slider 45 by the upward elastic force of a spring 51 provided between the upper arm 49s of the driven lever and the guide 41. An upper feed dog 55 is rotatively coupled at the rear end thereof to the driven lever 49 at the lower end thereof and guided by an upper feed rest guide 56 rotatably supported by a block attaching rod 52 at the lower end thereof, so that the rest is slid. The rod 52 receives a downward elastic force from a spring 54 provided between the arm 52s of the rod and the head body 53, so that a presser not shown in FIG. 7 is usually at a standstill in contact with a needle plate not shown in FIG. 7. The upper arm 52p of the rod 52 is for lifting the lower arm 45o of the slider 45 when the rod is lifted by a lifter not shown in FIG. 7. The lower feed mechanism of the sewing machine is described from now on. In the mechanism, a lower feed vertical motion shaft 62 is rotatably supported by bearings 62a and 62b. A timing pulley 61 is mounted on the shaft 62 at the input end thereof and coupled to the timing pulley 8 by a timing belt 9. A cam 63 is mounted on the shaft 62 at the output end thereof. A slider 64 is straightly moved vertically while being guided by a linear guide 66 secure to the head body 53. A cam follower 60 is attached to the slider 64 at the upper portion thereof and engaged with the cam 63 by the elastic force of a spring 67 provided between the arm 64s of the slider at the lower end thereof and the linear guide 66. The slider 64 is restricted by a means not shown in FIG. 7, so that the slider does not rotate about the axis of the straight motion thereof. FIG. 8 shows the case that the cam 63 is composed of a main cam 63a for causing the slider 64 to perform a desired motion, and an auxiliary cam 63b for preventing the cam follower 60 from jumping from the main cam. In that case, the cam follower 60 is engaged with the main cam 63a and attached to the slider 64, and another cam follower 74 is engaged with the auxiliary cam 63b and attached to the slider. The two cam followers 60 and 74 do not separate from the main and the auxiliary cams 63a and 63b due to the phase of the cam 63. The operation of the sewing machine shown in FIG. 7 is described from now on. The motion of the needle rod and thread take-up mechanism 12 of the machine and the motion of the shuttle hook 19 thereof are the same as those of the sewing machine shown in FIG. 4. The torque of the main shaft 1 of the machine shown in FIG. 7 is transmitted to the upper feed vertical motion shaft 43 through the timing pulley 4, the timing belt 5 and the timing pulley 42 so that the cam 44 mounted on the shaft is rotated. The torque of the cam 44 acts through the cam follower 46 so that the slider 45 is straightly moved vertically while being guided by the head body 53, and the driven lever 49, which is coupled at the upper end thereof with the bottom of the slider through the cam follower 50 and guided by the guide portion 41 of the horizontal driving lever 40 so as to be straightly moved, is moved vertically. The torque of the main shaft 1 acts through an eccentric wheel 6, a rod 7 and an upper feed quantity controller 20 to swing an upper feed horizontal motion shaft 38 whose swing motion is converted into that of the horizontal driving lever 40 through the engagement of the two-split output end portion 38o of the upper feed horizontal motion shaft and the member 39 rotatively coupled to the lever. The swing motion of the lever 40 acts to swing the driven lever 49 which is guided by the guide portion 41 of the horizontal driving lever 40. Thus, the driven lever 49 performs both the vertical motion and the swing motion because of the torque of the main shaft 1. For that reason, the upper feed dog 55 rotatively coupled at the rear end thereof to the driven lever 49 at the lower end thereof and guided for sliding, at the front portion of the dog by an upper feed rest guide 56 rotatably supported by the block attaching rod 52 performs a horizontal motion and a swing motion so that upper feed teeth 57 attached to the bottom of the front portion of the dog perform a pseudo-elliptic feed motion. In the upper feed mechanism, the direction of the vertical motion of the driven lever 49 is reverse to that of the vertical motion of the upper feed teeth 57. In other words, the teeth 57 are moved down when the lever 49 is moved up. When the block attaching rod 52 is pushed up in the upper feed mechanism by a push-up means not shown in FIG. 7, the upper feed dog guide 56 is moved up so that the upper feed teeth 57 are moved up. In that case, since there is a gap between the upper arm 52p of the lifter attaching rod 52 and the lower engaging portion 45o of the slider block 45 as the rod is moved down, the upper feed dog 55 is rotated counterclockwise at the time of the upward motion of the rod. For that reason, when the rod 52 is pushed up, the bottoms of the upper feed teeth 57 are moved up to a position above that of the bottom of the presser not shown in FIG. 7. The horizontal motion of the lower feed mechanism of the sewing machine shown in FIG. 7 is the same as that of the lower feed mechanism of the sewing machine shown in FIG. 4. The torque of the main shaft 1 is transmitted to the lower feed vertical motion shaft 62 through the timing pulley 8, the timing belt 9 and the timing pulley 61 so that the cam 63 mounted on the shaft at the tip thereof is rotated. The torque of the cam 63 acts through the cam follower 60 so that the slider 64 is straightly moved vertically while being guided by the head body 53, and the front portion of the lower feed dog 59 fitted at the front end 59o thereof with a plurality of cam followers 65 engaged with the upper arm 72 of the slider 64 on the top and bottom of the arm is moved vertically. Since a horizontal motion is transmitted to the lower feed dog 59 at its rear end rotatively coupled to a lower feed horizontal motion lever 68, the lower feed teeth 75 attached to the top of the central portion of the dog perform a pseudo-elliptic feed motion. In the case shown in FIG. 8, the cam 63 is composed of the main cam 63a as the body of the cam and the auxiliary cam 63b for preventing the main cam from jumping from the cam follower, one 60 of the plural cam followers 60 and 74 attached with a gap therebetween to the slider 64 is in contact with the main cam, and the other 74 of them is in contact with the auxiliary cam. Since the auxiliary cam 63b is shaped so that the plural cam followers 60 and 74 located at a prescribed distance from each other are always simultaneously in contact with the main cam 63a and the auxiliary cam, regardless of the phase of the cam 63, the cam followers 65 do not jump even if the rotation speed of the cam increases. Since the slider is disposed between the cam and the feed dog in the case shown in FIG. 8, the cam followers 60 and 74 are not moved in directions C and D as the feed dog is moved in the directions. FIG. 9 shows the eccentric wheels, the rod and the vicinity of them in each of the conventional sewing machines shown in FIGS. 4 and 7. The eccentric wheel 101, which is denoted by 8 in FIG. 4 and by 10 in FIG. 7, is secured to the main shaft 1 by a screw 102, and the rod 103, which is denoted by 9 in FIG. 4 and by 11 in FIG. 7, is rotatively coupled to the wheel. When the main shaft 1 shown in each of FIGS. 4 and 7 is rotated, the eccentric wheel 101 secured to the shaft is rotated so that the rod 103 is swung in directions C and D and directions A and B, or, to be exact, the center of the ring of the rod at the upper end thereof performs a circular motion and the tip of the rod, which is not shown in FIG. 9, is moved in the directions A and B. FIG. 10 shows the vertical motion of the feed teeth 27, which is caused by the above-mentioned motion of the tip of the rod 103, in the sewing machine shown in FIG. 4 and not having a cam unit. FIG. 11 shows the vertical motion of the feed teeth 75, which is caused by the above-mentioned motion of the tip of the rod 103, in the sewing machine shown in FIG. 7 and having the cam unit. FIG. 10 shows the vertical motion of the feed dog 59 and the feed teeth 75 in their elliptic motion during the sewing operation of the sewing machine shown in FIG. 4 and not having the cam unit. In FIG. 10, the axis of abscissas and that of ordinates denote the rotation angle θ of the main shaft 1 and the vertical position h of the feed teeth 75, respectively. The motion of the feed teeth 75 during the single round of the rotation of the msin shaft 1 or during a single stitch is denoted by a curve P→Q→R→S→T shown in FIG. 10. A point P or T shown in FIG. 10 indicates the bottom dead point of the feed teeth 75. A point R shown in FIG. 10 indicates the top dead point of the feed teeth 75. A point Q shown in FIG. 10 indicates the instant at which the feed teeth 75 come up out of a needle plate not shown in the drawings or the teeth collide against a presser. A point S shown in FIG. 10 indicates the instant at which the feed teeth 75 go into the needle plate or the teeth separate from the presser. As mentioned above, the feed teeth 75 collide against the presser at the point Q at which the phase of the main shaft 1 is θQ, and the teeth separate from the presser at the point S at which the phase of the main shaft is θS. The larger the angle α between the tangent on the curve and the positive direction of the axis of abscissas is, the higher the speed of the vertical motion of the feed teeth 75 is. As understood from FIG. 10, the feed teeth 75 collide against the presser at the time of the maximum speed of the upward motion of the teeth. FIG. 11 shows the vertical motion of the feed dog 59 and the feed teeth 75 in their elliptic motion during the sewing operation of the sewing machine shown in FIG. 7 and having the cam unit. The axis of abscissas and that of ordinates shown in FIG. 11 denote the rotation angle θ of the main shaft 1 and the vertical position h of the feed teeth 75, respectively. Symbols shown in FIG. 11 denote the same as those in FIG. 10 except symbols A, B, C and D. The vertical motion of the feed teeth 75 is denoted by a curve P→Q→R→S→T shown in FIG. 11. The speed of the vertical motion of the feed teeth 75 is zero (α=0) at a point Q at which the teeth collide against a presser, and at a point S at which the teeth separate from the presser. The feed teeth 75 are moved up at a prescribed speed toward the collision point Q, and moved up at a sharply decreasing speed in the immediate vicinity of the collision point. The speed of the upward motion of the teeth 75 instantaneously becomes zero at the time of the arrival at the collision point Q. Immediately after the arrival at the collision point Q, the teeth 75 are moved up further while the speed thereof increases gradually. At a point H or R indicating the top dead point of the motion of the teeth 75, the teeth begin to be moved down. The speed of the downward motion of the teeth 75 instantaneously becomes zero at a point S due to an action reverse to that in the above-mentioned upward motion of the teeth, so that the teeth are put out of contact with the presser. Such operation is repeated to feed a sewn object. In the sewing machines employing the cam units shown in FIGS. 6 and 8, it is enabled by appropriately predetermining the form of the cam that the feed teeth 75 are caused to perform the motion shown in FIG. 11. For the motion, the cam has such a form that the speed of the collision of the feed teeth 75 with the presser is approximate to zero. When the lower feed horizontal output lever 68 is swung in the directions A and B in the sewing machine shown in FIG. 6, the cam follower 60 is moved in the directions C and D so that the cam follower deviates from a vertical line λ-λ' extending through a cam shaft 62. For that reason, it is complicated to design the form of the cam 63. This is a problem. Besides, it is geometrically difficult to provide a positive cam. This is also a problem. The sewing machine shown in FIG. 8 was developed as one of means for solving the problems. However, since the sliding block 64 is added to prevent the cam follower 74 from deviating the vertical line λ-λ', the sewing machine is complicated. Since the conventional sewing machines are constituted as described above, the vertical motion shaft 62 needs to be rotated if the cam unit is provided to reduce the speed of the collision of the feed teeth 75. This is a problem. If a positive cam such as the lower feed vertical motion cam 63 is provided to prevent a cam follower from jumping from the cam when the cam is rotated rapidly, the cam follower 65 and the slider 64, which are moved straightly, need to be provided so that the constitution of the machines is complicated. This is also a problem. SUMMARY OF THE INVENTION The present invention was made in order to solve the above-mentioned problems. Accordingly, it is an object of the present invention to provide a cam unit capable of causing the shaft of a section to perform a desired motion, without changing the kind of the motion of the shaft and adding a straightly moved member to the cam unit to complicate it. The cam unit comprises a main cam, a first auxiliary cam, a second auxiliary cam, a rod, a motion transmission means, a jump prevention means, and a shaft. The first auxiliary cam is provided in contact with the main cam. The second auxiliary cam is provided in contact with the first auxiliary cam. The rod is provided between the main cam and the second auxiliary cam and has a slenderly shaped hole in which the peripheral portion of the first auxiliary cam is located in contact with the rod so that the rod is swing while being guided by the first auxiliary cam. The motion transmission means is secured to the rod and located on the peripheral portion of the main cam so as to move the rod in accordance with the contour of the main cam. The jump prevention means is secured to the rod and located on the peripheral portion of the second auxiliary cam so as to prevent the motion transmission means from jumping from the main cam. The shaft of the cam unit extends through all the cams. A positive cam is constituted by the main cam, the auxiliary cams and the rod without guiding a driven member to straightly move it. A motion is directly transmitted to a swinging member by the cam unit. For these reasons, it is enabled without complicating the cam unit that the unit causes the shaft of the section to perform the desired motion. It is another object of the present invention t provide a sewing machine which employs such a cam unit and is high in the degree of freedom of design or in the degree of easiness of causing the output section of the machine to perform a desired motion and is simple in constitution. The sewing machine includes the cam unit, and upper feed dog, upper feed teeth, and lower feed teeth. The cam unit comprises a main cam, a first auxiliary cam, a second auxiliary cam, a rod, a motion transmission means, a jump prevention means, and a main shaft. The first auxiliary cam is provided in contact with the main cam. The second auxiliary cam is provided in contact with the first auxiliary cam. The rod is provided between the main cam and the second auxiliary cam and has a slenderly shaped hole in which the peripheral portion of the first auxiliary cam is located in contact with the rod so that the rod is swung while being guided by the first auxiliary cam. The motion transmission means is secured to the rod and located on the peripheral portion of the main cam so as to move the rod in accordance with the contour of the main cam. The jump prevention means is secured to the rod and located on the peripheral portion of the second auxiliary cam so as to prevent the motion transmission means from jumping from the main cam. The main shaft extends through all the cams so as to transmit torque. The upper feed dog is supported by a vertical motion rod supported to be vertically movable and can be reciprocated in conjunction with the rotation of the main shaft. The upper feed teeth are provided on the upper feed dog. The lower feed teeth are provided so that the lower feed teeth can be put into and out of contact with the upper feed teeth by the cam unit as the torque of the main shaft is transmitted to the cams. The cam unit is capable of causing the feed section or the like of the sewing machine to perform a desired motion. The speed of collision of the feed teeth with a presser can be made nearly zero by the simple cam unit without rotating a vertical motion shaft and using a special member such as a cam follower and a slider. DESCRIPTION OF THE DRAWINGS FIG. 1(a) is a front view of a cam unit which is an embodiment of the present invention; FIG. 1(b) is a longitudinally sectional view of the cam unit; FIG. 2 is a front view of the feed transmission section of a sewing machine, which employs such a cam unit; FIG. 3 is a schematic view of a sewing machine employing such cam units; FIG. 4 is a structural view of a conventional differential vertical sewing machine; FIG. 5 is a view of the lower feed mechanism of another conventional differential vertical sewing machine; FIG. 6 is a view of the lower feed mechanism of yet another conventional differential vertical sewing machine; FIG. 7 is a structural view of the lower of yet another conventional differential vertical sewing machine employing a cam unit; FIG. 8 is a view of the lower feed mechanism of yet another conventional differential vertical sewing machine; FIG. 9(a) is a front view of the eccentric wheel and rod of each of the sewing machines shown in FIGS. 4 and 7; FIG. 9(b) is a longitudinally sectional view of the eccentric wheel and the rod; and FIGS. 10 and 11 are time charts of the vertical motions of feed teeth. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Embodiments of the present invention are hereafter described in detail with reference to the drawings attached hereto. FIG. 1 shows a cam unit 104 which is one of the embodiments. The cam unit 104 includes a main cam 104a, auxiliary cams (A and B) 104b and 104c, a driven rod 105, a cam follower 106, a cam follower 107, and stop rings 108. The main cam 104a is shaped as a plate. The auxiliary cam (B) 104c is shaped as a disk and smaller in diameter than the main cam 104a. The other auxiliary cam (A) 104b is shaped as a plate, provided in contact with the preceding auxiliary cam (B) 104c, and nearly equal in size to the main cam. The driven rod 105 is provided between the main cam 104a and the auxiliary cam (A) 104b and has a slenderly shaped hole 105c in which the peripheral portion of the auxiliary cam (B) 104c is located in contact with the driven rod. The cam unit 104 also includes a main shaft 101 extending through the main cam 104a and the auxiliary cams (A and B) 104b and 104c in the axial directions thereof. The main cam 104a and the auxiliary cams (B and A) 104c and 104b are secured to each other and then secured to the main shaft 101 by a screw 109. The cam follower 106 is a bearing provided on the peripheral portion of the main cam 104a so as to serve as a motion transmission means for moving the rod 105 in accordance with the contour and rotation of the main cam. The cam follower 106 is secured with one of the stop rings 108 to a pin 105a calked to the rod 105. The cam follower 107 is a bearing provided on the peripheral portion of the auxiliary cam (A) 104b so as to serve as a jump prevention means for preventing the cam follower 106 from jumping from the main cam 104a. The cam follower 107 is secured with the other of the stop rings 108 to a pin 105b calked to the rod 105. The head of the rod 105 has the slenderly shaped hole 105c in which the auxiliary cam (B) 104c is disposed coaxially with the main shaft 101. The rod 105 has two flat facets 105d and 105e extending along the major axis of the slenderly shaped hole 105c. The auxiliary cam (B) 104c is guided by the flat facets 105d and 105e so that an imaginary straight line extends on the axis of the cam followers 106 and 107 and the axis of the main shaft 101. FIG. 2 shows a feed transmission section including the cam unit 104 instead of an eccentric wheel for a sewing machine. The feed transmission section also includes a feed vertical motion shaft 129 and a link 128 secured to the shaft by a screw 130 and rotatively coupled at the free end of the link to the rod 105 at the lower end thereof by a pin 105f. The operation of the cam unit 104 is described from now on. When the main shaft 101 is rotated, the rod 105 is reciprocated in directions A and B in accordance with the contour curve of the main cam 104a because the cam follower 107 prevents the other cam follower 106 from jumping from the main cam and the auxiliary cam (B) 104c is fitted on the flat facets 105d and 105e on the slenderly shaped hole 105c. Since the auxiliary cam (B) 104c is fitted on the flat facets 105d and 105e to perform such restriction that the imaginary straight line always extends on the axis of the cam followers 106 and 107 and the axis of the main cam 104a, the main cam and the cam follower 106 always remain engaged with each other, the auxiliary cam (A) 104b and the cam follower 107 always remain engaged with each other and the cam followers 106 and 107 are prevented from jumping from the rolling surfaces of the main cam and the auxiliary cam (A) 104b in the rapid rotation of the cams. The rod 105 is accurately reciprocated in the directions A and B in accordance with the contour curve of the main cam 104a as the cams are rotated by the main shaft 101. Since the rod 105 is not guided to be straightly moved, the rod is enabled to be swung in directions C and D about the main shaft 101 while being reciprocated in the directions A and B. In other words, the rod 105, which is moved by the cam, is not confined to being guided to be straightly moved. In the feed transmission section shown in FIG. 2, the rod 105 is reciprocated in the directions A and B and the link 128 coupled to the rod by the pin 105f is swung in directions A' and B' about the shaft 129 as the main cam 104 is rotated by the main shaft 101. Although the pin 105f provided at the lower end of the rod 105 is required to be moved in the directions C and D, due to the swing of the link 128, the requirement is not a problem because the rod is enabled to be swung in the directions C and D about the axis 0 of the main shaft 101. FIG. 3 shows a differential vertical sewing machine which employs four such cam units instead of eccentric wheels and is the other of the embodiments. The cam units are provided in positions A, B, C and D. The same reference symbols in FIGS. 3 and 4 denote equivalents. The cam units in the positions A, B, C and D are for an upper feed vertical motion, an upper feed horizontal motion, a lower feed horizontal motion and a lower feed vertical motion, respectively. The motions are caused in the upper and lower feed sections of the sewing machine in accordance with the contour curves of the cams of the cam units as the main shaft 101 of the machine is rotated. The operation of the other sections of the sewing machine, which is caused by the rotation of the main shaft 101, is the same as that of the conventional sewing machines. Although the cam follower 107 for preventing the other cam follower 106 from jumping from the main cam 104a is made of the bearing in the embodiments described above, the present invention is not confined thereto but may be otherwise embodied so that the preceding cam follower is made of a sliding roller or a pin not having a rotary portion. Although the auxiliary cams (A and B) 104b and 104c are integrated with each other in the embodiments, the present invention is not confined thereto but may be otherwise embodied so that the auxiliary cams are separate from each other and secured to the main shaft 101. The auxiliary cam (B) 104c may be substituted by the main shaft 101. As far as the slenderly shaped hole 105c of the rod 105 functions to guide the auxiliary cam (B) 104c, the form of the hole may differ from that shown in FIG. 1. Although the cam units are applied to the main shaft of the differential vertical sewing machine of the vertical needle type, the cam units may be applied to the motion transmission sections of sewing machines of various types. What is claimed is: 1. A cam unit comprising:a main cam; a first auxiliary cam provided in contact with said main cam; a second auxiliary cam provided in contact with said first auxiliary cam; a rod provided between said main cam and said second auxiliary cam and having a slenderly shaped hole wherein a peripheral portion of said first auxiliary cam is located in contact with said rod so that said rod is swung while being guided by said first auxiliary cam; a motion transmission means secured to said rod and located on a peripheral portion of said main cam for moving said rod in accordance with a contour of said main cam; a jump prevention means secured to said rod and located on a peripheral portion of said second auxiliary cam for preventing said motion transmission means from jumping from said main cam; and a shaft extending through all said cams. 2. A cam unit according to claim 1, wherein said main cam and said first and second auxiliary cams are secured to each other and then secured to said shaft by a screw. 3. A cam unit according to claim 1, wherein said motion transmission means is a first cam follower for moving the rod in accordance with the contour and rotation of said main cam. 4. A cam unit according to claim 3, wherein said first cam follower is secured with a first stop ring to a pin calked to said rod. 5. A cam unit according to claim 3, wherein said first cam follower is a bearing. 6. A cam unit according to claim 1, wherein said jump prevention means is a second cam follower for preventing said first cam follower from jumping from said main cam. 7. A cam unit according to claim 6, wherein said second cam follower is secured with a second stop ring to a pin calked to the rod. 8. A cam unit according to claim 6, wherein said second cam follower is a bearing. 9. A sewing machine wherein a cam unit, an upper feed dog, upper feed teeth and lower feed teeth are included; said cam unit comprises a main cam, a first auxiliary cam, a second auxiliary cam, a rod, a motion transmission means, a jump prevention means and a main shaft; said first auxiliary cam is provided in contact with said main cam; said second auxiliary cam is provided in contact with said first auxiliary cam; said rod is provided between said main cam and said second auxiliary cam and has a slenderly shaped hole in which a peripheral portion of said first auxiliary cam is located in contact with said rod so that said rod is swung while being guided by said first auxiliary cam; said motion transmission means is secured to said rod and located on a peripheral portion of said main cam so as to move said rod in accordance with a contour of said main cam; said jump prevention means is secured to said rod and located on a peripheral portion of said second auxiliary cam so as to prevent said motion transmission means from jumping from said main cam; said main shaft extends through all said cams so as to transmit torque; said upper feed o dog is supported by a vertical motion rod supported to be vertically movable and can be reciprocated in conjunction with the rotation of said main shaft; said upper feed teeth are provided on said upper feed dog; and said lower feed teeth are provided so that said lower feed teeth can be put into and out of contact with said upper feed teeth by said cam unit as the torque of said shaft is transmitted to all said cams.

1990-09-18

en

1991-12-10

US-53968290-A

Pneumatically-controlled, user-operated switch interface ABSTRACT A pneumatically-controlled, user-operated switch interface which allows a physically disabled person to operate electronic equipment such as a computer, television, video cassette recorder and a remote control includes apparatus providing at least one airway passage; first switching circuitry for producing a plurality of switching signals and having at least one pneumatuc switch responsive to air pressure in the at least one airway passage; second switching circuitry settable in first and second switch positions for selectively connecting each of the plurality of switching signals to selected inputs of the electronic equipment as the electrical input signals, and user-activated apparatus for setting the second switching circuitry in the first and second switch positions. The switch interface can operate a plurality of computer input devices to allow a physically handicapped person to use commercially available software packages. BACKGROUND OF THE INVENTION The invention relates in general to methods and apparatus for operator interfacing with electrical devices, and more particularly to a pneumatic switch interface which allows physically disabled people to interact with a computer. Even the most routine tasks most people encounter in everyday life, including operating televisions, telephones, computers and other electronic equipment, become great challenges when attempted by a severely physically handicapped person. As a result, physically disabled persons are largely forced to be dependent on others to help them accomplish these basic needs. Previously, substantial efforts have been devoted to the design of user-operated devices that permit the physically disabled to perform tasks by exploiting the abilities they do have. Thus, a number of devices have been developed which are adapted to be operated by extremities in which even severely physically handicapped people typically retain some degree of movement. One such device is disclosed in U.S. Pat. No. 3,229,059 to Beatty, which comprises a chin-operated switching controller that controls a television or radio when a person turns his head from side-to-side. Although devices such as the Beatty controller allow handicapped persons to perform simple tasks, they are becoming increasingly disfavored due to their limited capability. Another approach is to use breath-controlled switches, which are especially helpful for the more severely physically handicapped persons, such as quadriplegics or bed-ridden patients. U.S. Pat. No. 4,298,863 to Natitus et al. discloses such a device wherein a bed-ridden patient blows on the pneumatic transducer of a portable patient call system to produce an alarm signal for calling a nurse. U.S. Pat. Nos. 3,848,249 to Meiri and 4,453,043 to Zielinski et al. disclose controllers for persons with motor impairments which automatically dial a telephone number when a person blows on a breath-operated microswitch. U.S. Pat. No. 4,207,959 to Youdin et al. discloses a voice-activated wheelchair controller with a plurality of breath-control tubes which override speech-activated control circuits to manually operate the movement of a motorized wheelchair. These devices help severely physically handicapped persons to perform various very simple tasks, but none are sophisticated enough to enable physically handicapped persons perform the complex tasks involved in operating a computer. One computer input device that allows a physically impaired person to perform a limited number of functions on a computer is described in U.S. Pat. No. 4,567,479 to Boyd. The Boyd device comprises vacuum-operated switches which are controlled by a separate breath-control tube. Each switch generates when actuated a control signal that is connected directly into a computer which is controlled by a specially-modified software program. The control signal generated by each switch is associated with a different single operation to be performed by the computer as specified by the modified program. The Boyd input device is thus not adaptable to other computers or computer programs without creating new interface software and hardware specific to each computer and computer program. In addition, the Boyd input device is cranially mounted and operated, which may easily fatigue a physically disabled user after prolonged use. Further, because the Boyd input device is cranially operated, a user may require assistance from another when placing or removing such a device from his or her head. SUMMARY OF THE INVENTION An object of the present invention is to provide a pneumatically-controlled, user-operated switch interface that allows a user to operate a computer without special programming by sipping and puffing into breath-control tubes to generate control signals which replicate the operation of a peripheral computer input device. Another object of the present invention is to provide a pneumatically-controlled, user-operated switch interface for electronic equipment which is switchable between different signal output modes to replicate the operation of a plurality of peripheral input devices. It is yet a further object of the present invention to provide a pneumatically-actuated, user-operated switch interface for controlling signal input to electronic devices that performs a greater number of functions through an innovative multi-integrated design than permitted by known breath-actuated switch interfaces. Another object of the present invention is to provide a compact, economical, non-fatiguing and easy to use electronic equipment input control system for use by persons who are severely physically disabled. It is yet a further object of the present invention to provide an electronic equipment input control system for physically disabled users that is compatible with off-the-shelf peripheral input devices. Still another object of the present invention to provide a stand-alone, breath-actuated switch interface which can be operated by a physically handicapped person and also by a non-physically disabled individual. These and other objects are achieved by a pneumatically-controlled, user-activated switch interface for providing electrical input signals to an electronic device via a plurality of inputs of the electronic device, wherein the switch interface comprises apparatus providing at least one airway passage; first switching circuitry for producing a plurality of switching signals and having at least one pneumatic switch responsive to air pressure in the at least one airway passage; second switching circuitry settable in first and second switch positions for selectively connecting each of the plurality of switching signals to selected ones of the plurality of electronic device inputs as the electrical input signals, and user-activated apparatus for setting the second switching circuitry in the first and second switch positions. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a is a block diagram showing a functional orientation of a pneumatic switch interface according to the invention. FIG. 1b is a block diagram showing a second functional orientation of a pneumatic switch interface according to the invention. FIG. 2 is a perspective view of a pneumatic switch interface according to the invention. FIG. 3 is a perspective view of a mouthpiece support unit suitable for use with the invention. FIG. 4 is a perspective view of a holding piece suitable for use with the invention. FIG. 5a is a more detailed perspective view of a mouthpiece support unit suitable for use with the invention. FIG. 5b is a diagram of an airway filtering system integrated into an integral mouthpiece unit suitable for use with the invention. FIG. 6 is an internal view of the switch housing of the switch interface of FIG. 1. FIG. 7 is a diagram of the control circuitry within the switch housing of the present invention. FIG. 8 is a diagram of the user-activated means for setting the second switching means of the switch interface of the present invention. FIG. 9 is a circuit diagram for a switch interface of the invention configured for a digitizer for use with a computer mouse. FIG. 10 is a circuit diagram for a switch interface of the present invention configured for a computer mouse. FIG. 11 is a circuit diagram for a switch interface of the present invention configured for a computer joystick. FIG. 12 is a circuit diagram for a switch interface of the present invention configured for a hand-held remote control for a television. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The electronic device which is controlled by the pneumatically-controlled, user-activated switch interface of the present invention may be any device which receives electrical input signals from another device. Preferably, the signals are received via input wires or infrared electromagnetic radiation. Suitable electronic devices include computers and remote-controlled consumer electronic equipment such as televisions, video cassette recorders and stereos. The pneumatically-controlled user-activated switch interface mimics the signals generated by a control device such as a computer input device, a video game controller or a television remote control. Typical computer input devices include a computer mouse, trackball, joystick, digitizing board, puck, and WIZ. Preferably, the switch interface contains circuitry which permits both conventional operation of the control device by a physically able individual, such as a care giver, and switch interface operation by a physically disabled individual when the care giver is unavailable. "Physically disabled" and "physically handicapped" are used synonymously herein, and mean an individual who does not have adequate motor control to operate commercially available electronic control devices which are used by the general public in everyday life. It is believed the switch interface will find its greatest utility and advantage among physically disabled persons who possess sufficient control over at least one of their arms and hands to permit them to use the user-activated means for setting the second switching means in the first and second switch positions. More severely disabled persons may utilize the switch interface with the assistance of another individual, such as a care giver, to use the user-activated means for setting the second switching means in the first and second switch positions. "High air pressure" means the higher than normal atmospheric air pressure produced by a person puffing or blowing into an airway passage. "Low air pressure" means the lower than normal atmospheric air pressure produced by a person sucking or sipping into an airway passage. The means for providing at least one airway passage may be any airtight passage which can conduct high and low air pressure from one end of the passage to the other. The airtight passage must be sufficiently strong not to burst under high air pressure and sufficiently rigid not to collapse under low air pressure. Preferably, the airtight passage is a flexible tube. Most preferably, the means for providing at least one airway passage include at least 3 separate flexible tubes, each made from an air impermeable plastic. One end of the airway passage communicates with the first switching means. The opposite end of the airway passage receives high and low air pressure from the user's mouth. Preferably, this is facilitated by means of a mouthpiece which is detachably attached to the opposite end of the airway passage. The first switching means for producing switching signals comprises at least one pneumatic switch responsive to the air pressure in the airway passage. Preferably, the first switching means will generate a first switching signal when there is high air pressure within the airway passage and a second switching signal when there is low pressure within the airway passage. A particularly preferred embodiment comprises a low-pressure responsive switch and a high-pressure responsive switch, each in airtight parallel communication with the airway passage, such that the air pressure within the airway passage is simultaneously applied to each switch. In a still more preferred embodiment, the first switching means comprise a plurality of such pairs of vacuum-actuated and pressure-activated switches, with each pair in separate communication with a separate airway passage. The second switching means comprises any means which is settable in first and second switch positions so as to selectively connect the switching signal generated by the first switching means to selected inputs of an electronic device. The second switching means are settable in the first and second switch positions by user-activated means, which may be any means which may be used to set the second switching means in its first and second switch positions. A rotatable switch incorporated into a housing of the switch interface, push buttons and slide switches are three preferred user-activated means for setting the second switching means. A particularly preferred embodiment includes at least one electrical switch exposed through an upper housing cap of the switch interface housing. The interface switch preferably includes a housing which may be preferably rotatably mounted upon a surface. The mounting includes securing means which preferably includes clamps, suction cups, screws or grips. The operation of the above-described pneumatically-controlled, user-operated switch interface may be briefly described as follows: The physically disabled user, or his or her care giver, turns on the electronic equipment which is desired to be used and manually selects either the first or second switch positions on the switch interface using the user-activated means for setting the second switching means, thus setting the switch interface to provide electrical signals which comprise input signals to the specific electronic equipment which is desired to be used. The physically disabled user may then control the operation of the electronic device by selectively puffing or sipping into the air passage, thereby creating electrical signals in the first switching means which are applied to the inputs of the electronic device through the second switching means. When the user desires to utilize the switch interface for a different electronic device, or a different electronic function of the same device, the user, or his or her care giver, simply employs the user-activated means for setting the second switching means to select the other switch position, thereby altering the inputs applied to the electronic device. Thus, the pneumatically-controlled, user-activated switch interface of the present invention may be employed by a physically disabled user to control more than one electronic device or more than one function of a complex electronic device. The general theory of operation of the present invention is illustrated in FIGS. 1a and 1b. Referring to FIG. 1a, a pneumatically-controlled, user-operated switch interface 1 in accordance with the invention is interposed between two electronic devices A and B. In general, the control signal output of device A controls the operation of device B. Typically, device A is an input device such as a computer mouse or joystick having manual switch buttons which, when pushed by a physically able person, control a computer program on the computer of device B. Switch interface 1 is wired in parallel with device A so that either device A or switch interface 1 may control the operation of device B. In this particular case, switch interface 1 replicates the operation of the mouse or joystick by reproducing the n-bit instruction word that is transmitted from device A into device B. FIG. 1b shows pneumatically-controlled, user-operated switch interface 1 in a similar but slightly different configuration in which switch interface 1 is interposed between components I and II of device A for generating a signal output for controlling device B. Typically, component I may be a computer puck having manual switch buttons which communicates with the digitizing tablet of component II for collectively controlling the operation of device B by a physically able person. Switch interface 1 is wired in parallel with the puck, thereby replicating the puck's signal output. Referring to FIGS. 2 and 3, a pneumatically-controlled switch interface 1 comprises a flexible tube 2 extending from a main body 3 to distal end 4. The distal end 4 of flexible tube 2 screws into threaded cap 5 of holding piece 6. Holding piece 6 has a pair of jaws 7 which hold a mouthpiece support unit 8. Main body 3 can be secured in a vertical position during switch interface operation, for example, by a suction cup that is attached to a lower housing cap 26 that grips the surface of a floor or desk top, or by a C-clamp that attaches around the circumference of a switch housing 25 of the main body 3 and screws onto a jutting table edge or the like. Switch housing 25 may be mounted horizontally on a table top as shown in FIG. 2. In this configuration, the main body 3 is mounted onto a short section of PVC tubing 43 in a swivel rigid mount connection. The threaded end 44 of the section of PVC tubing screws into a mounting plate 45 attached onto the surface of a table. The swivel action of main body 3 provides an added degree of freedom to a handicapped user. For instance, by gripping mouthpieces 10 with his or her teeth, a user may rotate the mouthpiece support unit 8 into a working position or may push the unit aside when a session is complete. As shown in FIG. 3, the bottom of each support ring 9 fastens to mounting stem 11 which serves to position the associated mouthpiece 10 for use by a physically disabled user. Stems 11 are mounted side-by-side in closely spaced planar relationship on short horizontal support bar 12 to allow ready access to any mouthpiece 10 without substantial effort by the user. Horizontal support bar 12 is mounted on one end of elongated tube 14 by support rod 13. Elongated tube 14 has a hooked distal end section 14a for locating the array of mouthpieces in a more accessible position for the user. The other end of elongated tube 14 extends into and frictionally engages the inner surface of a short, conically-shaped hollow support member 15. Jaws 7 of the holding piece 6 grip the outer surface of hollow support member 15 to effectively support the mouthpiece support unit 8 in place. The hollow support member 14 rotates within jaws 7 to position the array of mouthpieces in different positions to accommodate the needs of each individual user. Referring to FIGS. 3, 4, 5a and 5b, mouthpiece support unit 8 includes an array of support rings 9, each of which frictionally holds a mouthpiece 10. Each mouthpiece 10 preferably has an internal wet cotton filter, for example as disclosed in U.S. Pat. No. 4,046,153, which collects saliva and entraps harmful bacteria during use of switch interface 1. The array is replaceable to maintain proper sanitation between multiple users. A plurality of air lines 16 are enclosed within the interior of flexible tube 2. Air lines 16 exit flexible tube 2 through hole 18 and extend into support member 15. At the open end 18 of elongated tube 14, air lines 16 separate, with each line extending into a hole 19 in the underside of a respective one of the mouthpieces 10. Air lines 16 are held in frictional contact with each hole 19 in an airtight connection. To prevent damage to air lines 16 that might occur as a result of crimping or twisting, a stainless steel spring or rigid reinforcing wire (not shown) may be fixed on the exterior surface of flexible tubing 2. Alternatively, each flexible tube 2 may be made from a protective ribbed metal tubing, such as the type of tubing used to sheath the receiver coils on a public telephone, that is durable enough to withstand normal every-day use. Flexible tube 2 is sufficiently long and flexible to assume any orientation required to position mouthpieces 10 for comfortable use by a physically handicapped user. Flexible tube 2 extends into main body 3 via opening 20 in upper housing cap 21, as shown in FIG. 6. Flexible tube 2 attaches to upper housing cap 21 by via threaded flange 22 which mates with connector attachment 23 on flexible tube 2. Each of the three air lines 16 are respectively connected to a first switching means which are mounted within switch housing 25 of main body 3. The second switching means is retained in rotatable housing portion 60 which is mounted between switch housing 25 and upper housing cap 21. The switch housing 25 may be made from PVC tubing that is secured to upper housing cap 21, via rotatable housing portion 60, and a lower housing cap 26 by screws (not shown) to form an enclosure around the first switching means. Specifically for the case where device B is a computer, as illustrated in FIG. 1a, pneumatically-controlled switch interface 1 generates a signal output which replicates the signal output of a selected peripheral computer input device A. The first switching means comprise arrays of pneumatic switch assemblies 28. The second switching means comprise a group of external manual selector switches 29. The array of pneumatic first switch assemblies 28 cooperates with the group of second switching means 29 to complete an electrical circuit for placing signal voltages onto the correct leads of a computer pin-plug interface for replicating the operation of an input device, based on the high and low air pressure exerted upon the pneumatic switch assemblies by the user. As shown in FIG. 7, each switch assembly 28 comprises associated vacuum and pressure sensitive micropneumatic switches 30A and 30B which produce switching signals in response to high and low air pressure created within an airline 16 by a user sipping or puffing onto a mouthpiece 10. Micropneumatic switches 30A and 30B are commercially available, i.e. Micropneumatic Logic Industry, Part #502-P-G-RANGE-A. Second switching means 29 selectively connect switching signals generated by the pneumatic first switching means 28 onto the correct pins of an 8-pin computer plug to produce a signal output that is compatible with a selected computer input device. It will be appreciated that first switching means (switch assemblies 28) and second switching means (selector switches 29) can be implemented using printed circuit board or integrated circuit technology in lieu of discrete components. Within switch housing 25, each air line 16 splits into two separate air lines 16a and 16b via a Y-shaped connector 33. Air lines 16a and 16b are connected to the associated vacuum switch 30A and the pressure switch 30B, respectively, so that the air pressure within each air line 16 is applied to both of its associated switches 30 simultaneously. During operation of switch interface 1, a puff of air on a mouthpiece 10 causes high air pressure within an associated air line 16 that is simultaneously applied to both an associated vacuum switch 30A and pressure switch 30B via communicating air line branches 16a and 16b. The high air pressure closes pressure switch 30B to generate a corresponding first signal output while the vacuum switch 30A remains inactive. Analogously, low air pressure caused by a sip through airline 16 closes a vacuum switch 30A to produce a corresponding second signal output while the pressure switch 30B remains inactive. Therefore, each airline 16 has the capability of specifying two independent functions that can be performed on a computer. Closing the pneumatic first switching means creates switching signals which are selectively directed onto the correct pin configuration by the second switching means (external selector switches 29) for replicating the signal output of a desired peripheral computer input device. By adding air lines and associated switching circuitry, switch interface 1 may be expanded to specify more functions. For example, a switch interface having two air lines is able to implement four functions, a switch interface having three air lines is able to implement six functions, and so on. Referring to FIG. 8, the second switching means are mounted so that four operator actuator members 29A thereof extend through hole 38 in rotatable housing portion 60. By varying the orientation of operator actuator members 29A between two switching configurations, the pneumatically-controlled switch interface can produce a signal output which replicates the signal output of a selected computer input device. Rotation of housing portion 60 so that rotatable housing portion 60 engages three of the four selector members 29A causes the selector members 29A to move into a second configuration. The fourth switch must be manually switched from one position to a second position. Switching configuration I produces a signal output which is compatible with a first class of input devices. Alternatively, switching configuration II produces a signal output which is compatible with a second group of input devices. Once a physically disabled user sips or puffs on a mouthpiece 10 to select a desired function on the computer, switch interface 1 replicates the signals produced by a selected input device by placing signal voltages on those leads which correspond to a specific input pin configuration. The signals pass from the switch housing along these leads into the computer serial input port for processing by the associated computer input device software. By selectively connecting signal voltages onto the correct pins of a computer plug interface, switch interface 1 can replicate the operation of various input devices. Input devices may be integrated onto the switch interface 1 by connecting the jack on an input device cable to its female counterpart 40 on an external cable that extends from switch housing 25. By the same token the switch interface 1 may employ an external cable to carry signals out from the switch housing for processing. FIG. 9 shows a practical example of how switch interface 1 replicates the operation of one class of input devices when second switching means 29 are moved into first switching configuration. FIGS. 10-12 show practical examples of how switch interface 1 can replicate the operation of a second class of input devices when second switching means 29 are moved into a second switching configuration. The circuit diagram of a pneumatically controlled, user-activated switch interface for replicating the signal output of a CALCOMP Model 33110 WIZ computer input device is shown in FIG. 9. The WIZ is a computer input device comprising a puck with six manual switch buttons which select functions on a digitizing board for implementing functions on a computer. Pneumatically-controlled switch interface 1 uses its first switching means to generate switching signals for replicating the signal generated by pushing each manual switch button. By manually placing selector switch M1 in the configuration shown, switch interface 1 generates switching signals from its first switching means 200-205 which reproduce the puck's manual switch button signals. The three air pressure-actuated switches 200, 202 and 204 and the three vacuum-actuated switches 201, 203 and 205 individually close to complete specific circuit paths which selectively connect signal voltages to output leads 6, 7 or 8 of pin-plug 210 on the digitizing board. The pneumatically-controlled first switching means of switch interface 1 is connected in parallel to corresponding leads from the WIZ input device so that it retains full operational capability in lieu of signals directed through switch interface 1. Pneumatically-controlled first switching means 200-205 individually close for generating a 4-pin signal for performing one of six distinct computer functions. Pins 1 and 2 carry source voltage from the digitizing board's power supply (not shown) to pneumatically-controlled first switching means 200-205. For example, pin 2 may carry a +5 V dc signal to vacuum-actuated switches 201,203,205. Accordingly, pin 1 carries -5 V dc to pressure-actuated switches 200,202,204. If +5 V dc is considered high (H) and -5 V is considered low (L), the following Table I represents the 6-line signal generated by pneumatically-controlled first switching means 200-205 across pins 6, 7 and 8 of an 8-pin computer serial port for performing 6 separate functions: TABLE 1 ______________________________________ Pins 6 7 8 Computer functions ______________________________________ -- -- L function 1 -- -- H function 2 -- L -- function 3 -- H -- function 4 L -- -- function 5 H -- -- function 6 ______________________________________ Specifically, when pneumatic switch 200 closes, which would be analogous to pressing a manual switch button on the WIZ's puck, -5 V dc is selectively connected from pin 1 along lead 250 to pin 8, making pin 8 go low. Similarly, when switch 201 closes, +5 V dc is selectively connected from pin 2 along lead 251 to pin 8 through selector switch M1, making pin 8 go high. This would correspond to closing a second manual switch on the WIZ puck. Analogously, when switch 202 closes, +5 V dc is selectively connected to pin 7, making it high. When switch 203 closes, -5 V dc is selectively connected to pin 7 through selector switch M2, making it low. And, when switches 204 and 205 close, -5 V dc and +5 V dc are placed on pin 6, respectively, making it low and high in each case. Selector switches M3 and M4 selectively connect source voltages from pins 1 and 2 to switches 204 and 205, respectively. Pins 3,4 and 5 are inoperative in this illustrative embodiment. For the second selector switch configuration, the circuit diagrams of switch interface 1 for replicating the push of buttons on a computer mouse, joystick, and a remote control are shown. A computer mouse typically has several buttons which, when pushed, control different functions on a computer. FIG. 10 shows the circuit diagram for switch interface 1 for a GENIUS Model GM-6 mouse. In this configuration, three pneumatically-controlled first switching means 300,301 and 302 generate switching signals which correspond to each of three manual switches on the mouse. The switching signals form a 3-bit digital signal which is selectively placed onto pins 6,7 and 8 for input into the computer when certain pneumatic switches are closed. Selector switch M1 connects source voltage from pin 2 to switch 301. Pins 1,3 and 4 bypass all associated pneumatic circuitry to carry mouse positional signals to the computer. Pin 5 is inoperative in this illustrative example. The following Table 2 defines the 3-bit digital code generated by switch interface 1 for emulating the operation of the mouse. TABLE 2 ______________________________________ Pins 6 7 8 Mouse functions ______________________________________ 0 0 1 switch 1 0 1 0 switch 2 1 0 0 switch 3 ______________________________________ FIG. 11 shows the circuit diagram for the switch interface 1 corresponding to a CALCOMP Model 23120 puck and digitizing board computer input device. In this configuration, an additional pneumatically-controlled switch 303 is added to the first switching means circuitry of FIG. 10. Pneumatic switching signals generate a 4-bit digital code that corresponds to each of four buttons on the puck. Selector switch M1 connects source voltage from pin 2 to the vacuum-actuated pneumatic switches. Pins 1,3 and 4 carry positional signals directly from the puck to the digitizing board bypassing all pneumatic circuitry. The following Table 3 defines 4-bit digital signal generated by switch interface 1 for replicating the operation of the puck. TABLE 3 ______________________________________ Pins 5 6 7 8 Computer functions ______________________________________ 1 0 0 0 function 1 0 1 0 0 function 2 0 0 1 0 function 3 0 0 0 1 function 4 ______________________________________ FIG. 12 shows the circuit diagram for a pneumatically-controlled, user-operated switch interface corresponding to a Curtis Mathis hand-held remote controller for a television set. In this configuration, additional pneumatically-controlled switches are added for performing six different television functions. By puffing or sipping into the appropriate air line, a user may be able to turn a television on or off, increase or decrease volume, and change the channel. Pin 8 is inoperative in this illustrative embodiment. The pneumatically-controlled, user-operated switch interface of the present invention may be used to operate any number of input devices, to provide a physically disabled person the ability to operate complicated drawing programs, such as AutoCAD, or video games, such as NINTENDO. Those of ordinary skill in this art will understand that the above-described embodiments are merely illustrative examples of the invention application. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope of the appended claims. I claim: 1. A pneumatically-controlled, user-actuated, switch interface for providing electrical input signals to an electronic device via a plurality-of inputs of said electronic device, said switch interface comprising:means for providing at least one airway passage; first switching means for producing a plurality of switching signals having at least one pneumatic switch responsive to air pressure in said at least one airway passage; second switching means settable in first and second switch positions for selectively connecting each of said plurality of switching signals to selected ones of said plurality of electronic device inputs as said electrical input signals; and user-activated means for setting said second switching means in said first and second switch positions. 2. The switch interface of claim 1, wherein said second switching means comprises a plurality of switches interconnected between said at least one pneumatic switch and said electronic device inputs, and said setting means comprises rotatable switch housing means for urging said plurality of switches between said first and second switch positions when rotated. 3. The switch interface of claim 1, wherein the electronic device is selected from the group consisting of a computer, a video game, a television, a video cassette recorder and a stereo. 4. The switch interface of claim 1, wherein said first switching means comprises a plurality of pairs of low air pressure-actuated and high air pressure-actuated switches. 5. The switch interface of claim 1, wherein said user-activated means for setting said second switching means includes at least one electrical switch exposed through an upper housing cap. 6. The switch interface of claim 1, wherein said input device retains full operational capability. 7. The switch interface of claim 1, wherein said first switching means is capable of generating two distinct electrical input signals per each airway passage. 8. The switch interface of claim 1, further comprising a housing and means for rotatably mounting said housing. 9. The switch interface of claim 8, wherein the mounting means includes means for securing said housing to a surface. 10. The switch interface of claim 9, wherein the securing means is selected from the group consisting of clamps, suction cups, screws and grips. 11. A user-actuated, pneumatically-controlled switch interface as specified in claim 1, wherein said electronic device is selected from the group consisting of a mouse, joystick, trackball, digitizing board, puck, and a remote control.

1990-06-15

en

1992-06-30

US-78544477-A

Apparatus for supporting a member from a drop-tile ceiling ABSTRACT Apparatus for supporting a member from a drop-tile ceiling is characterized by a decorative escutheon having a recess therein sized to receive a resilient grasping element and to guide the grasping element for movement against the bias of its resiliency from a first, open, to a second, grasping, position. In one embodiment the grasping element has a threaded extension extending therefrom which is engaged by a hook structure such that engagement of the hook with the threaded extension draws the grasping element into the recess to move the grasping element from the open to the grasping position. In another embodiment, the grasping member has a threaded nut thereon which receives a threaded element insertable into the escutheon such that progressive threaded engagement draws the grasping element into the recess to move it from the open to the grasping position. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to apparatus for suspending members from the channel beams of drop-tile ceilings, and in particular, to apparatus wherein a resilient grasping element is drawn against the bias of its own resiliency into a recess to move grasping arms thereon from an open to a closed position. 2. Description of the Prior Art Drop-tile ceilings under consideration utilize channel beams of inverted T shape suspended from the structural members of the building. The ceiling panels are received upon the unexposed sides of the legs of the T. The top surface of the T is presented for view. With the advent of such drop-tile ceiling construction, the ability to suspend members, such as flowering plants, artistic mobiles or wall partitions, has decreased. This occurs because such suspended ceilings are fabricated of a material usually insufficient to securely support the weight of a hanging member. The prior art discloses several devices utilizing hook elements having slotted bases adapted to be received over the legs of the T. Typical of such devices are U.S. Pat. Nos. 3,198,471 (Meyer) and 3,618,176 (Barnes). However, such devices must be slipped onto the T-shaped channel beams before the beams are suspended in place, implying a predetermination of location for a suspended member and a permanency not typically encountered. Other prior art devices have permitted insertion or placement after the fact of erection of the ceiling. Typical of these devices are U.S. Pat. Nos. 3,327,376 (Freeman et al.) and 3,743,228 (Drab). However, these devices are unartistically utilitarian and do not offer an aesthetically pleasing or decorative mode of suspension from drop-tile ceilings. U.S. Pat. Nos. 347,489 (Kenway) and 2,284,302 (Roberts) are typical of prior art construction supports utilizing threaded elements to draw grippers or jaws together to support wire, piping, or the like. It is therefore advantageous to provide an easily and expeditiously placeable and removeable apparatus able to securely support relatively heavy objects from the channel beams of drop-tile ceilings. It is also advantageous to provide such an apparatus with an aesthetically pleasing or decorative appearance so as not to detract from the appearance of the member being suspended. SUMMARY OF THE INVENTION This invention relates to apparatus for suspending an article, as a potted plant, artistic mobile or a wall partition, from a channel beam or T-bar of a drop-tile ceiling. The invention includes a decorative escutcheon having a recess in the underside thereof. An opening is provided extending through the escutheon communicating with the recess therein. A resilient grasping element, having first and second arms, each of the arms bent at a joint to define facing opposed flanges, is moveable against the bias of its resiliency into the recess in the escutheon. Closure means are provided to move the grasping element to the grasping element to the grasping position. In one embodiment, the closure means comprises a threaded extension on the grasping element sized to pass through the opening in the escutheon. The arms are moveable from an open to a grasping position. In the open position, the clearance, or span between the the flanges is wider than the width dimension of a channel beam of a drop-tile ceiling. A support hook, adapted to receive the member or item to be suspended, has a threaded aperture therein. The progressive reception of the threaded extension into the aperture draws the resilient grasping element against the bias of its resiliency into the recess to move the arms and flanges to the closed, grasping, position. In the closed position the clearance between the flanges closes, to contact the joints against the lateral edges of the channel beam. In a second embodiment, the resilient grasping element has an opening therein registerable with the opening in the escutheon and has a threaded nut comprising the closure means. The nut receives a threaded element through the registerable openings such that progressive threaded engagement of the nut with the threaded element moves the grasping element against the bias of its resiliency to the grasping position. In both embodiments the recess in the escutheon has a dimension, in a plane perpendicular to an axis through the opening and in a plane parallel to the exposed surface of the channel beam, at least 3/16ths of an inch greater than the width dimension of the channel beam. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following detailed description thereof, taken in connection with the accompanying drawings which form a part of this application, and in which: FIG. 1 is a perspective view of a drop-tile ceiling having a supporting apparatus embodying the teachings of this invention suspended therefrom; FIG. 2 is an exploded view of the elements comprising a supporting apparatus embodying the teachings of this invention; FIG. 2A is a view taken along lines 2A--2A of FIG. 2; FIG. 3 is a section view taken through a supporting apparatus embodying the teachings of this invention in the first, open, position; FIG. 4 is a view similar to FIG. 3 showing a supporting apparatus in the second, grasping, position; FIG. 5 is an exploded view similar to FIG. 2 of a second embodiment of the invention; FIG. 6 is a sectional view, similar to FIG. 3, showing the second embodiment of the invention in the open position; and, FIG. 7 is a sectional view, similar to FIG. 4, showing the second embodiment of the invention in the second, grasping, position. DESCRIPTION OF THE PREFERRED EMBODIMENT Throughout the following description, similar reference numerals refer to similar elements in all Figures of the drawings, which form a part of this application. In FIG. 1, a perspective view of a drop-tile ceiling 10 having a supporting apparatus 12 embodying the teachings of this invention suspended therefrom. The ceiling 10 is fabricated of a lattice-like framework of structural channel members 14 of an inverted T-construction suspended from the building superstructure by conventional means, as appreciated by those skilled in the art. A plurality of substantially flat panels 16 are disposed in the area between adjacent legs of the T-bars 14, the peripheral edges of the panels 16 being supported in the under surfaces 15 of the channels 14. The upper surface 17 of the T-bar 14 is exposed to view and defines a substantially planar surface exhibiting a predetermined width dimension, usually 15/16-ths of an inch, between the lateral edges of the T-bar 14. The supporting apparatus 12 is expeditiously placeable and removable from any desired location along any of the channels 14. The supporting apparatus 12, is fabricated of a construction sufficient to support a relatively heavy load, as a hanging plant with potting arrangement thereof, at least in excess of 50 pounds. Furthermore, the apparatus 12 exhibits a pleasing aesthetic appearance to the eye of an observer. In FIG. 2, an exploded view of the supporting apparatus 12 embodying the teachings of this invention. The apparatus 12 includes a decorative escutheon 20, or baseplate having an aesthetically attractive exterior, having a recess 22 on the underside 23 thereof. The escutheon has a central axial opening 24 therethrough, the opening 24 communicating with both the exterior of the escutheon 20 and the recess 22 on the interior, underside 23 thereof. The recess 22 has a predetermined configuration, typically square, when viewed in a plane parallel to the exposed surface 17 of the upper surface of the T-bar or channel 14, or in a plane perpendicular to an axis 26 through the opening 24 in the escutheon. Although a square recess is preferred, it is understood that any predetermined configuration may be used, so long as at least one dimension of the recess 22 is at least three-sixteenths (3/16) of an inch greater than the width dimension of the channel. For example, if the preferred squre recess 22 is utilized in connection with a standard 15/16 inch T-bar 14 of a drop-tile ceiling, the dimension of each side of the mouth of the recess 22 is 11/8 inches. A resilient grasping element 30, such as an integral resilient leaf spring, comprises means for grasping a channel 14. Of course, other suitable grasping elements may be utilized. The resilient leaf spring 30 comprises a base portion 32, having first and second substantially upstanding arms 34A and 34B extending therefrom. The end of each of the arms 34 is bent, as at joints 36A and 36B, to define inwardly, opposed flanges 38A and 38B. The resilient grasping element 30 is moveable within the recess 22 from a first, open, to a second, closed or grasping, position. In the first, open, position, the ends of the flanges 38 define a clearance dimension, or span, 40 wider than and sized to fit over the width dimension of the channel 14. (FIG. 3). In the second, grasping, position (FIG. 4), the clearance 40' between ends of the flanges 38 is narrowed, with the inside surfaces of the joints 36 being contacted against the lateral edges of the channel 14. As seen in FIG. 4, to insure support of the member, the inside of the joints 36 are preferably abutted against the lateral edges of the channels 14 with the undersides 39 of the flanges overlapping the unexposed surfaces 15 of the channel 14. Closure means 41 for moving the grasping means from the first, open, to the second, grasping, position, to close the flanges 38 of the resilient grasping element 30 are provided. In the first embodiment of the invention, the closure means comprises a threaded extension or bolt 42 affixed to and extending from the base 32 of the resilient leaf spring 30. The extension 42 is adapted to pass through the opening 24 through the escutheon 20. A support member 50, such as a hook element with a flared baseplate 51 comprises means adapted to receive a member to be supported from the channel 14. The support member 50 preferably has a threaded aperture 52 therein, the threaded extension 42 being threadedly advanceable or retractable therein. Progressively threaded engagement of the threaded extension 42 within the aperture 52 draws the resilient leaf spring 30 against the resiliency of its bias into the recess 22 in the escutheon 20, to bring the ends of the flanges 38 toward the other, to narrow the clearance span 40. Threading a 3/16 of an inch of the extension 42 1/2 inch into the aperture 52 draws the joints 36 into direct abutting contact with the lateral edges of the channel and is sufficient to support at least 50 pounds from the channel 14. When it is desired to emplace a support apparatus 12 at a predetermined location along a channel 14, it is merely necessary to place the flanges 38, with the initial clearance 40, over the width of the channel 14. Progressive threaded advancement of the extension 42 into the aperture 52 of the support hook 50, as by rotation of the support hook 50, draws the resilient leaf spring 30 against the bias of its resiliency into the recess 24, to close the clearance 40 and bring the joints 36 into the illustrated abutting contact with the edges of the channel 14. As seen in FIGS. 5 and 6, in a second embodiment of the invention, the closure means 41 comprises a threaded nut 55 disposed about the periphery of an opening 56 in the base 32 of the leaf spring 30. The opening 56 is registered with the opening 24 in the escution 20. The nut 55 is threadedly engageable with an element 57 affixed to a member, as a wall partition, to be supported. The element 57 is insertable through the registered openings 24 and 56 such that progressive threaded engagement of the nut 55 with the threaded element 57 draws the spring 30 against the bias of its resiliency into the recess 22 to close the clearance 40 and bring the joints 36 into the abutting contact between the lateral edges of the channel, as in FIG. 7. As is the case with the embodiment of FIGS. 2-4, the recess 22 is square when viewed in a plane parallel to the plane of the exposed surface 17 of the channel 12, or in a plane perpendicular to the axis of the opening 24 in the escutheon 20. It is preferred that the sides of the recess be at least 3/16 of an inch greater than the width of the exposed surface 17 of the T-bar or channel 12. Having described preferred embodiments of the invention, modifications thereto may be effected as appreciated by those skilled in the art yet remain within the contemplation of this invention, as defined in the appended claims. What is claimed is: 1. Apparatus for supporting a member from a channel beam of a drop-tile ceiling comprising:a decorative escutheon having a recess therein and having an opening therethrough communicating with said recess; a resilient element for grasping the channel beam, said grasping element having a first and a second arm each bent at a joint toward the other to define an inwardly extending flange substantially perpendicular to its associated arm, said grasping element being moveable within said recess from a first, open, position to a second, grasping, position, said grasping element having a dimension between the ends of the flanges such that, in said first position, said grasping element is sized to span the width dimension of the channel beam, said flanges of said grasping element being dimensioned such that, in said second position, the grasping element is in grasping engagement with the channel beam so that said joint in each of said arms is contracted against the edges of the channel beam; and, closure means extending through said opening in said escutheon and connected to said grasping element for moving said grasping element from said first position to said second, grasping, position. 2. Apparatus according to claim 1, wherein:said grasping element comprises a resilient leaf spring; and, said closure means comprises a threaded extension extending from said leaf spring through said opening in said escutheon. 3. Apparatus according to claim 2, further comprising:a hook having a threaded aperture therein adapted to receive said threaded extension such that progressive threaded engagement of said extension and said hook draws said resilient spring against the bias of its resiliency into said recess to move said spring from said open position to said grasping position, said hook being adapted to receive a member to be supported therefrom. 4. Apparatus according to claim 1, wherein:said grasping element comprises a resilient leaf spring having an opening therein registrable with said opening in said escutheon; and, said closure means comprises a threaded nut mounted on said leaf spring to register with said opening therein; said nut adapted to receive a threaded element insertable through said registered openings in said escutheon and said spring such that progressive threaded engagement of said nut with the insertable element draws said resilient spring against the bais of its resiliency into said recess to move said spring from said open to said grasping position. 5. Apparatus according to claim 1, wherein at least one dimension of said recess in said escutheon in a plane parallel to an exposed surface of the channel beam is at least 3/16 of an inch greater than the width dimension of the channel beam measured in the same plane. 6. Apparatus according to claim 1 wherein said recess in said escutheon is substantially square in a plane parallel to an exposed surface of the channel beam and wherein the dimension of one side of said square is at least 3/16 of an inch greater than the width dimension of the channel beam measured in the same plane. 7. Apparatus for supporting a member from a channel beam of a drop-tile ceiling, comprising:a decorative escutcheon having a recess in the underside thereof and an opening therethrough communicating with said recess; a resilient grasping element having first and second arms, the end of each of said arms bending at a joint toward the other to define opposed flanges, said resilient grasping element having a threaded extension sized to pass through said opening in said decorative escutheon, said arms being moveable from a first, open, position to a second, grasping, position as said resilient member is drawn into said recess; said grasping element in said first, open, position defining a clearance between said flanges wider than the width dimension of a channel beam of a drop-tile ceiling, said grasping element in said second, grasping, position contacting said joints against the lateral edges of a channel beam of a drop-tile ceiling; and, a hook support member for receiving a member to be supported, said support member having a threaded aperture therein, said threaded extension being progressively threadedly engageable within said aperture to draw said resilient member against the bias of its resiliency into said recess to move said resilient member from said first, open, to said second, grasping, position. 8. Apparatus according to claim 7, wherein said recess in said decorative escutheon is substantially square in a plane perpendicular to an axis through said opening. 9. Apparatus according to claim 8, wherein said dimension of said square is at least 3/16 of an inch greater than the width dimension of a channel beam of a drop-tile ceiling. 10. Apparatus for supporting a member from a channel beam of a drop-tile ceiling comprising:a decorative escutheon having a recess in the underside thereof and an opening therethrough communicating with said recess; a resilient grasping element having first and second arms, the end of each of said arms bending at a joint toward the other to define opposed flanges, said resilient grasping element having an opening therein registrable with said opening in said escutheon, said arms being moveable from a first, open, position to a second, grasping, position as said resilient member is drawn into said recess; said grasping element in said first, open, position defining a clearance between said flanges wider than the width dimension of a channel beam of a drop-tile ceiling, said grasping element in said second, grasping, position contacting said joints against the lateral edges of a channel beam of a drop-tile ceiling; and, a threaded nut mounted on said resilient grasping element to register with said opening therein, said nut adapted to receive a threaded element insertable through said registered openings in said escutheon and said resilient grasping element such that progressive threaded engagement of said nut with the insertable element draws said resilient grasping element against the bias of its resiliency into said recess to move said grasping element from said open to said grasping position. 11. Apparatus according to claim 10, wherein said recess in said decorative escutheon is substantially square in a plane perpendicular to an axis through said opening. 12. Apparatus according to claim 11, wherein said dimension of said square is at least 3/16 of an inch greater than the width dimension of a channel beam of a drop-tile ceiling.

1977-04-07

en

1978-10-03

US-27728994-A

Stripline resonator ABSTRACT A stripline resonator is constructed of a dielectric plate having a ground electrode formed on a side surface thereof, an open-ended λ/2 long stripline arranged on a top surface of the dielectric plate, an input terminal to which signals are inputted, said input terminal is connected to one end of the open-ended λ/2 long stripline, a first reactance element connected either in series or in parallel between the input terminal and the open-ended λ/2 long stripline, and a second reactance element connected at one end thereof to an opposite end of the open-ended λ/2 long stripline and at an opposite end to a ground electrode. BACKGROUND OF THE INVENTION This invention relates to a filter suitable for use in a high-frequency band in a communication equipment, especially a mobile radiophone. A conventional stripline resonator is illustrated in FIG. 16. Referring to FIG. 16, the conventional stripline resonator is described. A side surface 104 and a bottom surface 105 of a dielectric plate 101 are metallized or plated over the entire surfaces thereof. The metallized or plated side surface 104 and bottom surface 105 are electrically maintained at the ground potential. A stripline resonator 103 is formed on a top surface 102 of the dielectric plate 101. The stripline resonator 103 is connected at one end thereof to an input terminal 108. At an area on the top surface 102, said area being apart by a predetermined distance from an opposite end of the stripline resonator 103, a marginal portion 106 is formed in such a way that the marginal portion is plated in continuation with the side surface 104. The opposite end of the stripline resonator 103 is connected to the marginal portion 106 via a lumped-constant element such as a capacitor 107. As a consequence, capacitance C is realized between the opposite end of the stripline resonator 103 and the side surface 104 which forms a ground electrode, whereby the stripline resonator 103 is equipped with an increased quality factor Q. SUMMARY OF THE INVENTION An object of the present invention is to provide a stripline resonator having a still higher quality factor Q. Another object of the present invention is to provide a stripline resonator which requires a small mounting area. In one aspect of the present invention, there is thus provided a stripline resonator comprising: an input terminal; an open-ended λ/2 long stripline arranged on a dielectric plate; and a reactance element connected at one end thereof to said input terminal and at an opposite end thereof to one end of said open-ended λ/2 long stripline. The stripline resonator may further comprise a reactance element connected at one end thereof to an opposite end of said open-ended λ/2 long stripline. According to the present invention, the stripline can be divided and arranged on plural dielectric plates and these dielectric plates can be arranged in a multilayer structure. Owing to the construction described above, the stripline resonator according to the present invention is equipped with a high quality factor and requires only a small mounting area. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a stripline resonator according to a first embodiment of this invention; FIG. 2 is an equivalent circuit diagram of the stripline resonator in FIG. 1; FIG. 3 is a perspective view of a stripline resonator according to a second embodiment of this invention; FIG. 4 is an equivalent circuit diagram of the stripline resonator in FIG. 3; FIG. 5 is a perspective view of a stripline resonator according to a third embodiment of this invention; FIG. 6 is an equivalent circuit diagram of the stripline resonator in FIG. 5; FIG. 7 is a perspective view of a stripline resonator according to a fourth embodiment of this invention; FIG. 8 is an equivalent circuit diagram of the stripline resonator in FIG. 7; FIG. 9 is a perspective view of a stripline resonator in which an open-ended λ/2 long stripline has been divided into three parts to provide a multilayer structure; FIG. 10 is a sectional view of an enlarged detail of a portion of in FIG. 9; FIG. 11 is a perspective view of a stripline resonator in which an open-ended λ/2 long stripline has been divided into three parts and inductance elements are connected between adjacent stripline parts, to an upstream side of the first stripline part and to a downstream side of the last stripline part, respectively; FIG. 12 is an equivalent circuit diagram of the stripline resonator in FIG. 11; FIG. 13 is a perspective view of another stripline resonator in which an open-ended λ/2 long stripline has been divided into three parts and inductance elements are connected between adjacent stripline parts, to an upstream side of the first stripline part and to a downstream side of the last stripline part, respectively; FIG. 14 shows a table of experimental data of a stripline divided into two parts; FIG. 15 illustrates a table of experimental data of a stripline divided into three parts; and FIG. 16 is a perspective view of a conventional stripline resonator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The stripline resonator according to the first embodiment of this invention is first described with reference to FIGS. 1 and 2. Referring first to FIG. 1, arranged on a top surface 7 of a dielectric plate 1 are an input terminal 2, a short-ended stripline 3, a terminal 4 and a capacitor 5. The short-ended stripline 3 forms an inductance component with a length shorter than λ/2. The short-ended stripline 3 is connected at one end thereof to the input terminal 2 and at an opposite end to a side surface 6. The input terminal 2 and the terminal 4 centrally define through-holes, respectively. These through-holes extend from the top surface 7 to a bottom surface 8. An inner wall of each through-hole is metallized or plated (hereinafter collectively called "plated"). On the bottom surface 8, electrode patterns of the same shape as the input terminal 2 are formed around outer peripheries of the through-holes, respectively. The terminal 4 and the side surface 6 are connected together via the capacitor 5. On the other hand, contacts 10,17 and an open-ended λ/2 long stripline 11 are formed on a top surface 15 of a dielectric plate 14 of the same shape and dimensions as the dielectric plate 1. The open-ended λ/2 long stripline 11 is connected at one end thereof to the contact 10 and at an opposite end thereof to the contact 17. The top surface 7 of the dielectric plate 1 is plated except for areas--where the input terminal 2, the short-ended stripline 3, the terminal 4 and the capacitor 5 are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 6 of the dielectric plate 1 is plated over the entire area thereof in continuation with the plated area of the top surface 7. The bottom surface 8 of the dielectric plate 1 is plated except for an area, which is brought into contact with the open-ended λ/2 long stripline 11 when the dielectric plate 1 and the dielectric plate 14 are stacked together, and an area extending over a predetermined distance from the contour of the first-mentioned area. Similarly, the top surface 15 of the dielectric plate 14 is plated except for areas--where the contact 10, the contact 17 and the open-ended λ/2 long stripline 11 are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 13 of the dielectric plate 14 is plated over the entire area thereof in continuation with the plated area of the top surface 15. The bottom surface 16 of the dielectric plate 14 is plated over the entire area thereof in continuation with the side surface 13. These plated surfaces are electrically maintained at the ground potential. When the dielectric plate 1 and the dielectric plate 14 are stacked together, the input terminal 2 and the contact 10 as well as the terminal 4 and the contact 17 are electrically connected via the plated inner walls of their corresponding through-holes. Accordingly, the stripline resonator of FIG. 1 can be represented by the equivalent circuit depicted in FIG. 2. In FIG. 2, an input terminal 201 is connected to one end of an open-ended λ/2 long stripline resonance circuit 204. An inductance 202 is connected at one end thereof in parallel between the input terminal 201 and the open-ended λ/2 long stripline resonator 204 and at an opposite end to a ground 203. An opposite end of the open-ended λ/2 long stripline resonator 204 is connected to a ground 206 via a capacitance 205. The route of the input terminal 201→the open-ended λ/2 long stripline resonance circuit 204→the capacitance 205→the ground 206 in FIG. 2 is therefore equivalent to the route of the input terminal 2→the contact 10→the open-ended λ/2 long stripline 11→the contact 17→the terminal 4→the capacitor 5→the side surface 6 in FIG. 1. Further, the route of the input terminal 201→the inductance 202→the ground 203 in FIG. 2 is equivalent to the route of the input terminal 2→the short-ended stripline 3→the side surface 6 in FIG. 1. When an inductance Lo is connected in parallel to an input terminal, the impedance Zin and quality factor Q can be expressed by the following formulas (1) and (2): ##EQU1## where Zo : characteristic impedance of a stripline, l: length of the stripline, al: 1/Q, n: 2, and Qs: Q of the stripline. The above two formulas indicate that a high quality factor Q is therefore obtained by an increase in the imaginary part of the impedance. The stripline resonator according to the second embodiment of this invention will next be described with reference to FIGS. 3 and 4. Referring first to FIG. 3, arranged on a top surface 28 of a dielectric plate 23 are an input terminal 20, a connecting terminal 21, a coil 22, a terminal 24 and a capacitor 25. The input terminal 20 is connected to the connecting terminal 21 via the coil 22, whereas the terminal 24 is connected to a side surface 26 via the capacitor 25. The connecting terminal 21 and the terminal 24 centrally define through-holes, respectively. These through-holes extend from the top surface 28 to a bottom surface 27. An inner wall of each through-hole is plated. On the bottom surface 27, electrode patterns of the same shape as the connecting terminal 21 are formed around outer peripheries of the through-holes, respectively. On the other hand, contacts 31,32 and an open-ended λ/2 long stripline 30 are formed on a top surface 33 of a dielectric plate 29 of the same shape and dimensions as the dielectric plate 23. The open-ended λ/2 long stripline 30 is connected at one end thereof to the contact 31 and at an opposite end thereof to the contact 32. The top surface 28 of the dielectric plate 23 is plated except for areas--where the input terminal 20, the connecting terminal 21, the coil 22, the terminal 24 and the capacitor 25 are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 26 of the dielectric plate 23 is plated over the entire area thereof in continuation with the plated area of the top surface 28. The bottom surface 27 of the dielectric plate 23 is plated except for an area, which is brought into contact with the open-ended λ/2 long stripline 30 when the dielectric plate 23 and the dielectric plate 29 are stacked together, and an area extending over a predetermined distance from the contour of the first-mentioned area. Similarly, the top surface 33 of the dielectric plate 29 is plated except for areas--where the contact 31, the open-ended λ/2 long stripline 30 and the contact 32 are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 34 of the dielectric plate 29 is plated over the entire area thereof in continuation with the plated area of the top surface 33. The bottom surface 35 of the dielectric plate 29 is plated over the entire area thereof in continuation with the side surface 34. These plated surfaces are electrically maintained at the ground potential. When the dielectric plate 23 and the dielectric plate 29 are stacked together, the input terminal 21 and the contact 31 as well as the contact 32 and the terminal 24 are electrically connected via the plated inner walls of their corresponding through-holes. Accordingly, the stripline resonator of FIG. 3 can be represented by the equivalent circuit depicted in FIG. 4. In FIG. 4, an input terminal 401 is connected to one end of an open-ended λ/2 long stripline resonance circuit 403 via an inductance 402. An opposite end of the open-ended λ/2 long stripline resonance circuit 403 is connected to a ground 405 via a capacitance 404. The route of the input terminal 401→the inductance 402→the open-ended λ/2 long stripline resonance circuit 403→the capacitance 404→the ground 405 in FIG. 4 is therefore equivalent to the route of the input terminal 20→the oil 22→the connecting terminal 21→the contact 31→the open-ended λ/2 long stripline 30→the contact 32→the terminal 24→the capacitor 25→the side surface 26 10 in FIG. 3. When an inductance Lo is connected in series to an input terminal, the input impedance Zin and the quality factor Q can be expressed by the following formulas as (3) and (4): ##EQU2## where Zo : characteristic impedance of a stripline, l: length of the stripline, al: 1/Q, n: 2, and Qs: Q of the stripline. The above two formulas indicate that a high quality factor Q is therefore obtained by an increase in the imaginary part of the impedance. The stripline resonator according to the third embodiment of this invention will now be described with reference to FIGS. 5 and 6. Referring first to FIG. 6, arranged on a top surface 42 of a dielectric plate 37 are an input terminal 36, a connecting terminal 47, a capacitor 41, a terminal 38 and a capacitor 39. The input terminal 36 is connected to the connecting terminal 47 via the capacitor 41, while the terminal 38 is connected to a side surface 40 via the capacitor 39. The connecting terminal 47 and the terminal 38 centrally define through-holes, respectively. These through-holes extend from the top surface 42 to a bottom surface 48. An inner wall of each through-hole is plated. On the bottom surface 48, electrode patterns of the same shape as the connecting terminal 47 or the input terminal 38 are formed around outer peripheries of the through-holes, respectively. On the other hand, contacts 44,52 and an open-ended λ/2 long stripline 45 are formed on a top surface 49 of a dielectric plate 46 of the same shape and dimensions as the dielectric plate 37 The open-ended λ/2 long stripline 45 is connected at one end thereof to the contact 44 and at an opposite end thereof to the contact 52. The top surface 42 of the dielectric plate 37 is plated except for areas--where the input terminal 36, the connecting terminal 47, the capacitor 41, the terminal 38 and the capacitor 39 are arranged, respectively --and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 40 of the dielectric plate 37 is plated over the entire area thereof in continuation with the plated area of the top surface 42. The bottom surface 48 of the dielectric plate 37 is plated except for an area, which is brought into contact with the open-ended λ/2 long stripline 45 when the bottom surface 48 of the dielectric plate 37 and the top surface 49 of the dielectric plate 48 are brought into a contiguous relation, and an area extending over a predetermined distance from the contour of the first-mentioned area. Similarly, the top surface 49 of the dielectric plate 46 is plated except for areas--where the contact 44, the terminal 52 and the open-ended λ/2 long stripline 45 are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 50 of the dielectric plate 46 is plated over the entire area thereof in continuation with the plated area of the top surface 49. The bottom surface 51 of the dielectric plate 46 is plated over the entire area thereof in continuation with the side surface 50. When the dielectric plate 37 and the dielectric plate 46 are stacked together, the connecting terminal 47 and the contact 44 as well as the contact 52 and the terminal 38 are electrically connected together via the plated inner walls of their corresponding through-holes. As a consequence, the stripline resonator in FIG. 5 can be represented by the equivalent circuit of FIG. 6. In FIG. 6, an input terminal 601 is connected to one end of an open-ended λ/2 long stripline resonance circuit 603 via a capacitance 602 and an opposite end of the open-ended λ/2 long stripline resonance circuit 603 is connected to a ground 605 via a capacitance 604. The route of the input terminal 601→the capacitance 602→the open-ended λ/2 long stripline resonance circuit 603→the capacitance 604→the ground 605 in FIG. 6 is equivalent to the route of the input terminal 36→the capacitor 41→the connecting terminal 47→the contact 44→the open-ended λ/2 long stripline 45→the contact 52→the terminal 38→the capacitor 39→the side surface 40 in FIG. 5. When a capacitance Co is connected in series to an input terminal, the input impedance Zin and the quality factor Q can be expressed by the following formulas (5) and (6): ##EQU3## where Zo : characteristic impedance of a stripline, l: length of the stripline, al: 1/Q, n: 2, and Qs: Q of the stripline. The above two formulas indicate that a high quality factor Q is therefore obtained by an increase in the imaginary part of the impedance. As is illustrated as the fourth embodiment of the present invention in FIG. 7, the capacitor 41 can also be connected in parallel relative to the open-ended λ/2 long stripline 45. Namely, the capacitor 41 is connected at one end thereof to the input terminal 36 and at an opposite end thereof to the plated area formed on the top surface 42. The construction of FIG. 7 is different from the construction of FIG. 5 only in that the capacitor 41, the input terminal 36 and the connecting terminal 47 are connected in different ways as described above. An equivalent circuit of the stripline shown in FIG. 7 can be illustrated as shown in FIG. 8. When a capacitance Co is added in parallel to an input terminal, the impedance Zin and the quality factor Q can be expressed by the following formulas (7) and (8): ##EQU4## where Zo : characteristic impedance of a stripline, l: length of the stripline, al: 1/Q, n: 2, and Qs: Q of the stripline. The above two formulas indicate that a high quality factor Q is obtained by an increase in the imaginary part of the impedance. Reference is next made to FIGS. 9 and 10, which show the stripline resonator in which the open-ended λ/2 long stripline has been divided into three parts to provide the multilayer structure. Striplines 59,60,61 are arranged on top surfaces 79,65,64 of dielectric plates 55,56,57, respectively. When these three dielectric plates are stacked together, the striplines 59,60,61 are mutually connected at their ends so that a single open-ended λ/2 long stripline is formed. A detailed description will now be made of the connection between the stripline 60 and the stripline 61 when the dielectric plate 56 and the dielectric plate 57 are stacked together. As is illustrated in FIG. 10, one end portion of the stripline 60 formed on the top surface 65 of the dielectric plate 56 extends continuously from the top surface 65 onto the side surface 62 and further onto a bottom surface 63. In opposition to the position of the stripline 60 arranged on the bottom surface 63, the stripline 61 is disposed on the top surface 64 of the dielectric plate 56. When the dielectric plate 56 and the dielectric plate 57 are stacked together, an end of the stripline 60 and a corresponding end of the stripline 61 are therefore electrically connected. The connection between the stripline 59 on the dielectric plate 55 and the stripline 60 on the dielectric plate 56 have the above-described construction. Referring to FIG. 9, a description will hereinafter be made of a construction in which the above three-piece open-ended λ/2 long stripline is employed and the above-described capacitors or coils are incorporated. Arranged on a top surface 76 of a dielectric plate 58 positioned at the top are an input terminal 70, a connecting terminal 71, a terminal 72 and a ground electrode 73. The input terminal 70 and the connecting terminal 71 are connected together via a coil 75. The terminal 72 and the ground electrode 73 are connected together via a capacitor 74. The terminal 72 and the connecting terminal 71 centrally defines through-holes. These through-holes extend from the top surface 76 to a bottom surface 78. An inner wall of each through-hole is plated. In registration with the through-hole formed in the terminal 72 on the dielectric plate 58, through-holes are formed in the remaining dielectric plates 59,60,61, respectively. Inner walls of these through-holes are also plated. On the top surface 79 of the dielectric plate 55 positioned underneath the dielectric plate 58, the contact 66 and the stripline 59 are arranged. The contact 66 is electrically connected to the above-described connecting terminal 71 via the corresponding through-hole. The stripline 59 is connected at one end thereof to the contact 66 and in the manner described above with reference to FIG. 10, is connected at an opposite end thereof to one end of the stripline 60 on the dielectric plate 56. Further, the stripline 60 is arranged on the top surface 65 of the dielectric plate 56 positioned underneath the dielectric plate 55. The stripline 60 is connected at one end thereof to the stripline 59 and in the manner described above with reference to FIG. 10, is connected at an opposite end thereof to the stripline 61. The stripline 61 and a contact 84 are arranged on the top surface 64 of the dielectric plate 57 positioned underneath the dielectric plate 56. The strip conductor 61 is connected at one end thereof to the contact 84 and as described above, is connected at an opposite end thereof to the stripline 60. The contact 84 is electrically connected to the terminal 72 via the plated inner walls of the through-holes formed in the individual dielectric plates. A description will next be made of plated areas of each dielectric plate. The top surface 76 of the dielectric plate 58 is plated except for areas--where the input terminal 70, the coil 75, the connecting terminal 71, the terminal 72, the capacitor 74 and the ground electrode are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The side surface 77 is plated over the entire area thereof in continuation with the plated area on the top surface 76. The bottom surface 78 is plated except for an area, which is brought into contact with the stripline 59 arranged on the dielectric plate 55 when the dielectric plate 58 and the dielectric plate 55 are stacked together, and an area extending over a predetermined distance from the contour of the first-mentioned area. The top surface 79 and side surface 80 of the dielectric plate 55 are plated except for areas--where the contact 66, the stripline 59 and the through-holes are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The bottom surface 81 is plated except for an area, which is brought into contact with the stripline 60 arranged on the dielectric plate 56 when the dielectric plate 55 and the dielectric plate 56 are stacked together, and an area extending over a predetermined distance from the contour of the first-mentioned area. The top surface 65 and side surface 62 of the dielectric plate 56 are plated except for areas--where the stripline 60 and the through-holes are arranged, respectively--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The bottom surface 63 is plated except for an area, which is brought into contact with the stripline 61 arranged on the dielectric plate 57 when the dielectric plate 56 and the dielectric plate 57 are stacked together, and an area extending over a predetermined distance from the contour of the first-mentioned area. The top surface 64 and side surface 85 of the dielectric plate 57 are plated except for areas--where the stripline 61 is arranged--and areas extending over a predetermined distance from the contours of the first-mentioned areas. The bottom surface 83 is plated over the entire area thereof. As will be explained below, an equivalent circuit of the stripline resonator in FIG. 9 can be illustrated as shown in FIG. 4. The route of the input terminal 401→the inductance 402→the open-ended λ/2 long stripline resonance circuit 403→the capacitance 404→the ground 405 in FIG. 4 is therefore equivalent to the route of the input terminal 70→the coil 75→the connecting terminal 71→the contact 62→the striplines 59,60, 61→the contact 84→the through-hole→the capacitor 74→the ground electrode 73. By changing the coil 75 to a capacitor and connecting the input terminal 70 to the connecting terminal via a capacitor in FIG. 9, the construction of the equivalent circuit of FIG. 6, which was described in connection with the third embodiment, can be realized. By changing the dielectric plate 58 in FIG. 9 to the dielectric plate 1 in FIG. 1, connecting the input terminal 2 to the contact 62 and connecting the terminal 4 to the contact 84 via the through-hole, the construction of the equivalent circuit of FIG. 2, which was described in connection with the first embodiment, can also be realized. Referring next to FIG. 11, the embodiment in which an open-ended λ/2 long stripline is constructed in a divided form on a single dielectric plate will be described. FIG. 11 is a perspective view in which the open-ended λ/2 long stripline described above with reference to FIG. 5 has been divided into three parts. In FIG. 11, element of structure identical to the corresponding elements in FIG. 5 are identified by like reference numerals and their description is omitted herein. In FIG. 11, striplines 45a,45b,45c which have been formed by dividing into three parts the open-ended λ/2 long stripline 45 shown in FIG. 5 are arranged on a top surface 49 of a dielectric plate 46. The stripline 45a is connected at one end thereof to a contact 44 and at an opposite end thereof to one end of the stripline 45b via a contact 93. An opposite end of the stripline 45b is connected to one end of the stripline 45c via a contact 94. Further, an opposite end of the stripline 35c is connected to a contact 52. On the other hand, a top surface 42 of a dielectric plate 37 is provided with connecting terminals 47a,47b and capacitors 91,92 in addition to the elements shown in FIG. 5. The connecting terminals 47a,47b centrally define through-holes which extend from the top surface 42 to a bottom surface 48. An inner wall of each through-hole is plated. On the bottom surface 48, electrode patterns of the same shape as the connecting terminal 47a or 47b are formed around outer peripheries of the through-holes, respectively, although the electrode patterns are not illustrated in FIG. 11. When the dielectric plate 37 and the dielectric plate 46 are stacked together, these electrode patterns are brought into contact with a contact 93 and a contact 94 arranged on a top surface 49 of the dielectric plate 46, respectively. Incidentally, the plating applied on the top surface 42 of the dielectric plate 37 is not applied in this embodiment at areas, where the connecting terminals 47a,47b are arranged, respectively, and areas extending over a predetermined distance from the contours of the first-mentioned areas. Further, the connecting terminal 47a is connected to the plated area via the capacitor 91, while the connecting terminal 47b is connected to the plated area via the capacitor 92. When the dielectric plate 37 and the dielectric plate 46 are stacked together, the contact 93 and the connecting terminal 47a as well as the contact 94 and the connecting terminal 47b are hence electrically connected together via the plated inner walls of the corresponding through-holes in addition to electrical connection between the input terminal 36 and the contact 44 and that between the contact 52 and the terminal 38. As a consequence, the stripline resonator of FIG. 11 can be illustrated by the equivalent circuit of FIG. 12. In FIG. 12, divided striplines 702,703,704 are connected in series. An input terminal 701 is connected to one end of the divided stripline 702. A reactance 705 is connected at one end thereof in series between the input terminal 701 and the stripline 702 and at an opposite end thereof to a ground 709. Further, a reactance 706 is connected at one end thereof in series between the striplines 702 and 703 and at an opposite end thereof to a ground 710. In addition, a reactance 707 is connected at one end thereof in series between the striplines 703 and 704 and at an opposite end thereof to a ground 711. The route of the input terminal 701→the striplines 702,703,704→the reactance 708→the ground 712 in FIG. 12 is thus equivalent to the route of the connecting terminal 47→the contact 44→the striplines 45a,45b,45c →the terminal 38→the capacitor 39→the side surface 40 in FIG. 11. Further, the reactances 705,706,707,708 correspond to the capacitors 41,91,92,39, respectively. When a stripline resonator is divided into two parts or three parts, the input impedances Zin2,Zin3 and quality factors Q2,Q3 can be expressed as will be described next. Zin2 can be expressed by the following formula (9): ##EQU5## Q2 can be expressed by the following formula (10): ##EQU6## where Zo : characteristic impedance of a stripline, l: length of the stripline, al: 1/Q, n: 2, ω: resonance frequency, and Qs : Q of the stripline. When experimental data on the two-piece stripline resonator are similarly divided into three parts, Zin3 can be expressed by the following formula (11): ##EQU7## Q3 can be expressed by the following formula (12): ##EQU8## where Zo : characteristic impedance of a stripline, l: length of the stripline, al: 1/Q, n: 3, ω: resonance frequency, and Qs : Q of the stripline. A high quality factor Q is therefore obtained by an increase in the imaginary part of the impedance. In the illustrated embodiment, the capacitors are connected between the divided striplines. Similar effects can be obtained when inductances, for example, coils 96,97,98,99 are similarly connected in place of the capacitors 41,91,92,39 as depicted in FIG. 13. In the illustrated embodiment, divided striplines are employed as the striplines 702,703,704. It is however borne in mind that the present invention is not limited to the use of such divided striplines. Similar effects can also be obtained when an open-ended λ/2 long stripline is arranged on the dielectric plate 46 and the contacts 93,94 are arranged on the open-ended λ/2 long stripline. Experimental data on stripline resonators having capacitance circuits arranged between divided striplines are shown in FIGS. 14 and 15. FIG. 14 shows a table of experimental data of a stripline divided into two parts. The data shown in FIG. 14 were obtained by changing the values of capacitors arranged between the divided striplines. According to the results of the experiment, it is appreciated that a stripline resonator having a capacitance added between divided parts of a stripline has higher Q than a stripline resonator not added with such capacitances. FIG. 15 illustrates a table of experimental data of a stripline divided into three parts. FIG. 15 shows experimental data obtained by changing the values of capacitors arranged between an input terminal and the stripline while fixing the values of the capacitors arranged between the divided striplines in view of the data of FIG. 15. From these results, it is also understood that a stripline resonator with capacitances added between divided striplines has a higher Q than a stripline resonator not added with any capacitance. What is claimed is: 1. A stripline resonator, comprising:an input terminal; an open-ended λ/2 long stripline arranged on a dielectric plate; a first reactance element having one end connected to said input terminal and an opposite end connected to one end of said open-ended λ/2 long stripline; and a second reactance element having one end connected to an opposite end of said open-ended λ/2 long stripline and an opposite end which is grounded. 2. A stripline resonator comprising:a first dielectric plate and a second dielectric plate arranged in a multilayer structure, wherein said first dielectric plate includes:a ground electrode, an input terminal extending from a top surface to a bottom surface of said first dielectric plate and electrically connecting said top surface and said bottom surface, a short-ended stripline having one end connected to said input terminal on a side of said top surface and an opposite end connected to said ground electrode and having an inductance component, a connecting terminal extending from said top surface to said bottom surface and electrically connecting said top surface and said bottom surface, and a capacitance element having one end connected to said connecting terminal on the side of said top surface and an opposite end connected to said ground electrode; and said second dielectric plate includes an open-ended λ/2 long stripline, said first dielectric plate and said second dielectric plate being stacked together, and said open-ended λ/2 long stripline having one end connected to said input terminal on a side of said bottom surface and an opposite end connected to said connecting terminal on the side of said bottom surface. 3. A stripline resonator according to claim 2, wherein said open-ended λ/2 long stripline is divided into a plurality of parts and arranged on said first and second dielectric plates. 4. A stripline resonator, comprising:a first dielectric plate and a second dielectric plate arranged in a multilayer structure, wherein said first dielectric plate includes:a ground electrode, a first connecting terminal extending from a top surface to a bottom surface of said first dielectric plate and electrically connecting said top surface and said bottom surface, an inductance element having one end connected to an input terminal on a side of said top surface and an opposite end connected to said first connecting terminal on the side of said top surface, a second connecting terminal extending from said top surface to said bottom surface and electrically connecting said top surface and said bottom surface, and a capacitance element having one end connected to said second connecting terminal on the side of said top surface and an opposite end connected to said ground electrode; and said second dielectric plate includes:an open-ended λ/2 long stripline, said first dielectric plate and said second dielectric plate being stacked together, and said open-ended λ/2 long stripline having one end connected to said input terminal on a side of said bottom surface and an opposite end connected to said second connecting terminal on the side of said bottom surface. 5. A stripline resonator according to claim 4, wherein said open-ended λ/2 long stripline is divided into a plurality of parts and arranged on said first and second dielectric plates. 6. A stripline resonator comprising:a first dielectric plate and a second dielectric plate arranged in a multilayer structure, wherein said first dielectric plate includes:a ground electrode, an input terminal on a top surface of said first dielectric plate, a first connecting terminal extending from said top surface to a bottom surface of said first dielectric plate and electrically connecting said top surface and said bottom surface, a first capacitance element having one end connected to said input terminal and an opposite end connected to said first connecting terminal on a side of said top surface, a second connecting terminal extending from said top surface to said bottom surface and electrically connecting said top surface and said bottom surface, a second capacitance element having one end connected to said second connecting terminal on the side of said top surface and an opposite end connected to said ground electrode; and said second dielectric plate includes:an open-ended λ/2 long stripline, said first dielectric plate and said second dielectric plate being stacked together, said open-ended λ/2 long stripline having one end connected to said input terminal on said bottom surface and an opposite end connected to said second connecting terminal on the side of said bottom surface. 7. A stripline resonator according to claim 6, wherein said open-ended λ/2 long stripline is divided into a plurality of parts and arranged on said first and second dielectric plates. 8. A stripline resonator, comprising:a first dielectric plate and a second dielectric plate arranged in a multilayer structure, wherein said first dielectric plate includes:a ground electrode, an input terminal extending from a top surface to a bottom surface of said first dielectric plate and electrically connecting said top surface and said bottom surface, a first capacitance element having one end connected to said input terminal on a side of said top surface and an opposite end connected to said ground electrode, a connecting terminal extending from said top surface to said bottom surface and electrically connecting said top surface and said bottom surface, and a second capacitance element having one end connected to said connecting terminal on the side of said top surface and an opposite end connected to said ground electrode; and said second dielectric plate includes:an open-ended λ/2 long stripline, said first dielectric plate and said second dielectric plate being stacked together, said open-ended λ/2 long stripline having one end connected to said input terminal on a side of said bottom surface and an opposite end connected to said connecting terminal on the side of said bottom surface. 9. A stripline resonator according to claim 8, wherein said open-ended λ/2 long stripline is divided into a plurality of parts and arranged on said first and second dielectric plates. 10. A stripline resonator, comprising:a first dielectric plate and a second dielectric plate arranged in a multilayer structure, wherein said first dielectric plate includes:a ground electrode, an input terminal extending from a top surface to a bottom surface of said first dielectric plate and electrically connecting said top surface and said bottom surface, a first reactance element having one end connected to said input terminal on a side of said top surface and an opposite end connected to said ground electrode, a connecting terminal extending from said top surface to said bottom surface and electrically connecting said top surface and said bottom surface, a second reactance element having one end connected to said connecting terminal on the side of said top surface and an opposite end connected to said ground electrode, at least one connecting electrode extending from said top surface to said bottom surface and electrically connecting said top surface and said bottom surface, and a third reactance element having one end connected to said connecting electrode on the side of said top surface and an opposite end connected to said ground electrode; and said second dielectric plate includes:an open-ended λ/2 long stripline, and at least one contact arranged on said open-ended λ/2 long stripline, wherein said first dielectric plate and said second dielectric plate are stacked together, said open-ended λ/2 long stripline has one end connected to said input terminal on a side of said bottom surface and an opposite end connected to said connecting terminal on the side of said bottom surface, and said contact is connected to said connecting electrode on the side of said bottom surface.

1994-07-22

en

1996-06-11

US-28385888-A

Torque transmitting and torsion damping apparatus for use in motor vehicles ABSTRACT A torsion damping apparatus between the crankshaft of the engine and the input shaft of the change-speed transmission of a motor vehicle has two flywheels one of which is driven by the crankshaft and the other of which drives the input shaft by way of a friction clutch which generates heat. In order to prevent the transfer of heat from the friction clutch to the antifriction bearing between the flywheels, which are rotatable relative to each other against the opposition of a damper, the bearing is at least partially surrounded by a thermal barrier of synthetic plastic, ceramic or metallic material which prolongs the useful life of the bearing and enhances the torsion damping action of the damper. The thermal barrier can constitute or form part of the damper. The bearing can be disposed radially inwardly of the location of engagement between the clutch and the other flywheel and can be cooled by streams of air flowing through an annulus of passages each having a first end disposed radially inwardly of the friction surface of the other flywheel and a larger second end in a second surface of the other flywheel opposite the friction surface. Heat barriers in the other flywheel can alternate with the passages in the circumferential direction of the other flywheel. CROSS-REFERENCE TO RELATED CASES This is a division of copending patent application Ser. No. 132,909, filed Dec. 14, 1987 now abandoned, which is a division of Ser. No. 000,470 filed Jan. 5, 1987 (now U.S. Pat. No. 4,727,970 which was a continuation-in-part of abandoned patent applications Ser. Nos. 716,838 (filed Mar. 28, 1985), 799,006 (filed Nov. 18, 1985) and 848,732 (filed Apr. 4, 1986). The apparatus of the present invention constitutes an improvement over and a further development of torque transmitting, torsion damping and similar apparatus which are disclosed in numerous pending U.S. patent applications and granted U.S. Letters Patent of the assignee. Reference may be had, for example, to commonly owned patent applications Serial Nos. 661,028 (filed Oct. 15, 1984) and now U.S. Pat. No. 4,638,684, 669,658 filed Nov. 8, 1984) and now abandoned, 669,659 (filed Nov. 8, 1984) and now abandoned, 669,769 (filed Nov. 8, 1984) and now abandoned, 669,770 (filed Nov. 8, 1984) and now abandoned, 669,768 (filed Nov. 8, 1984) and now abandoned, 717,327 (filed Mar. 29, 1985) and now abandoned, 706,498 (filed Feb. 28, 1985) and now U.S. Pat. No. 4,611,701, 745,016 (filed June 14, 1985) now U.S. Pat. No. 4,729,464, 801,565 (filed Nov. 25, 1985) and now abandoned and 844,475 (filed Mar. 26, 1986) now U.S. Pat. No. 4,782,933. BACKGROUND OF THE INVENTION The present invention relates to torque transmitting and torsion damping apparatus, especially to improvements in torque transmitting and torsion damping apparatus which can be utilized in motor vehicles to compensate for fluctuations of torque which is transmitted between driving and driven components, particularly between the crankshaft of the internal combustion engine and the input shaft of the change-speed transmission in a passenger car or another motor vehicle. It is already known to provide a torsion damping apparatus, which is installed in a motor vehicle between the crankshaft of the internal combustion engine and the input shaft of the changespeed transmission, with several flywheels which are rotatable relative to each other within certain limits and against the opposition of one or more dampers. Such apparatus are disclosed, for example, in commonly owned copending patent application Ser. No. 669,657, now abandoned of Oswald Friedmann as well as in several other pending applications of the assignee. The flywheels can rotate relative to each other about the axis or axes of one or more bearings. A friction clutch is interposed between the last flywheel and the input shaft of the transmission, and such friction clutch includes a disc which is movable into and out of friction- and heat-generating engagement with the adjacent flywheel. This can adversely influence the operation and useful life of the bearing, especially if the races of the bearing are directly connected to or in direct contact with the adjacent flywheels. Thus, one race of an antifriction ball bearing between two coaxial flywheels which can move angularly relative to each other against the opposition of one or more dampers can be non-rotatably secured to one of the flywheels, and the other race of the bearing can be non-rotatably secured to the other flywheel. It has been found that the just described mounting of the flywheels on an antifriction bearing enables the damper or dampers to produce a highly satisfactory damping action. Nevertheless, such torsion damping apparatus failed to gain popularity in the automotive and other industries, primarily because the useful life of the bearing or bearings between the flywheels is relatively short. The bearing or bearings are one of the critical elements in these torsion damping apparatus so that their failure after a relatively short interval of use deters the manufacturers of motor vehicles from employing such torsion damping apparatus between the engine and the change-speed transmission. A torque transmitting and torsion damping apparatus between the input shaft of a change-speed transmission and the output shaft of an engine must be capable of taking up stresses, such as those attributable to fluctuations of transmitted torque, which develop while a rotary driving element transmits torque to a rotary driven element. As a rule, or in many instances, the crankshaft of the engine is attached directly to a first flywheel, the input shaft of the transmission can receive torque from a second flywheel by way of a friction clutch, and the means for transmitting torque between the flywheels comprises one or more dampers which oppose angular movements of the flywheels relative to each other. The second flywheel has a friction surface which is engaged by a lining of the clutch disc of the friction clutch when the latter is engaged to transmit torque from the second flywheel to the transmission. The bearing or bearings between the flywheels have pairs of races confining single or multiple rows of antifriction rolling elements in the form of needles, balls, rollers or the like. The bearing or bearings enable the torque transmitting and torsion damping apparatus to perform a highly satisfactory damping of oscillations which develop in the power train between the engine and the transmission. Nevertheless, and as already stated above, such apparatus failed to gain widespread acceptance due to the short useful life of the bearing or bearings. As a rule, the bearing or bearings constitute the first part or parts which require replacement, and such replacement must take place after a relatively short period of use. One of the main reasons that the useful life of the antifriction bearing or bearings between the flywheels of the above outlined torque transmitting apparatus is relatively short is that the bearings are subjected to pronounced thermal stresses, primarily because the friction clutch between the input element of the change-speed transmission and the respective flywheel invariably generates heat when it is called upon to transmit torque to the transmission. The damper or dampers which are provided between the relatively movable flywheels of the just outlined torque transmitting apparatus normally comprise at least one set of coil springs or analogous energy storing elements which yieldably oppose angular movements of the flywheels relative to each other, as well as one or more friction generating devices each of which can oppose some or all angular movements of the flywheels relative to one another. The damper or dampers contribute significantly to the initial and maintenance cost of the torque transmitting apparatus. OBJECTS AND SUMMARY OF THE INVENTION An object of the invention is to provide a torsion damping apparatus which can be used in motor vehicles as a superior substitute for heretofore known torsion damping apparatus and is constructed, dimensioned and assembled in such a way that it and its bearing or bearings can stand long periods of use. Another object of the invention is to provide a torsion damping apparatus wherein the bearing or bearings between the flywheels can be shielded from undesirable influences of the adjacent parts of the apparatus in a simple and inexpensive but efficient way. A further object of the invention is to provide a torsion damping apparatus wherein the damper or dampers can perform their functions more efficiently than in heretofore known apparatus, even though their construction need not depart, or need not appreciably depart, from the construction of dampers in conventional torsion damping apparatus. An additional object of the invention is to provide a novel and improved method of shielding the bearing or bearings and/or the damper or dampers of a torsion damping assembly from undesirable influences of other component parts of the apparatus, especially of the friction clutch between one of the flywheels and the input element of the change-speed transmission in a motor vehicle. Still another object of the invention is to provide a torsion damping apparatus which exhibits the above outlined features but need not be bulkier, more complex and/or more expensive than heretofore known apparatus. A further object of the invention is to provide an apparatus which is designed for controlled transmission of torque between the crankshaft of the internal combustion engine and the input shaft of the change-speed transmission in a motor vehicle and is capable of effectively opposing and damping undesirable fluctuations of torque in the power train between the engine and the wheels of the vehicle. Another object of the invention is to provide a novel and improved method of combining the bearing or bearings with other parts of the above outlined torsion damping apparatus. Another object of the invention is to provide novel and improved bearings for use in the above outlined torsion damping apparatus. An additional object of the invention is to provide novel and improved flywheels for use in the above outlined torsion damping apparatus. A further object of the invention is to provide a novel and improved method of preventing heat from adversely influencing the bearing or bearings and/or other sensitive parts of a torsion damping apparatus of the type wherein a flywheel can transmit torque to a rotary element by way of a friction clutch. An additional object of the invention is to provide a novel and improved device for preventing heat which is generated during actual use of the torsion damping apparatus from affecting the useful life of certain sensitive parts including the bearing or bearings and one or more dampers. Another object of the invention is to provide novel and improved means for preventing escape of lubricant from the bearing or bearings in a torsion damping apparatus of the above outlined character. A further object of the invention is to provide a torsion damping apparatus wherein the useful life of the bearing or bearings can match the useful life of other constituents. Another object of the invention is to provide the above outlined apparatus with novel and improved means for preventing the heat which is generated by the friction clutch from adversely influencing the bearing or bearings between the flywheels. A further object of the invention is to provide a relatively simple, compact and inexpensive torque transmitting apparatus which can be used with particular advantage between the crankshaft of the internal combustion engine and the input element of the change-speed transmission in a motor vehicle. An additional object of the invention is to provide a novel and improved method of shielding the bearing or bearings between the flywheels from excessive thermally induced stresses. Still another object of the invention is to provide an apparatus of the above outlined character whose components can be assembled or taken apart in a simple and time-saving manner and which can automatically ensure uniform wear upon the component parts of the bearing or bearings between the flywheels. A further object of the invention is to provide the apparatus with novel and improved means for damping and opposing the movements of flywheels relative to each other. A further object of the invention is to provide a novel and improved mounting for the bearing or bearings between the flywheels as well as to provide novel and improved damper means between such flywheels. Another object of the invention is to achieve the above-enumerated objects in a simple and inexpensive way. Another object of the invention is to provide the apparatus with novel and improved means for prolonging the useful life of the antifriction bearing or bearings between the components of its flywheel. A further object of the invention is to provide novel and improved means for withdrawing heat and for keeping heat away from the bearing or bearings of the above outlined apparatus. Still another object of the invention is to provide the torque transmitting apparatus with a simple and inexpensive flywheel and with novel and improved means for cooling one or more parts of the friction clutch between the flywheel and the input shaft of the change-speed transmission. An additional object of the invention is to provide an apparatus wherein heat is withdrawn from the friction clutch in a direction to avoid the transfer of such heat to sensitive parts of the apparatus. A further object of the invention is to provide a power train which embodies the above outlined apparatus and to provide a motor vehicle which embodies the power train and the apparatus. An additional object of the invention is to provide a novel and improved method of cooling the flywheel, the antifriction bearing means and/or the clutch in the above outlined apparatus. Another object of the invention is to provide a novel distribution of heat barriers in the flywheel or flywheels of the above outlined apparatus. An additional object of the invention is to provide a torque transmitting apparatus which is constructed and assembled in the above-outlined manner and can be installed in the power trains of existing motor vehicles. The invention is embodied in a torsion damping apparatus which is especially suited to take up and to compensate for fluctuations of torque which is transmitted from the crankshaft of the internal combustion engine to the rotary input element of the change-speed transmission in a motor vehicle. One embodiment of the improved torsion damping apparatus comprises a plurality of flywheels including preferably but not necessarily coaxial fist and second flywheels which are movable angularly relative to each other, single or plural damper means operating between the first and second flywheels to yieldably oppose angular movements of such flywheels relative to each other, bearing means (e.g., one or more antifriction needle, ball or roller bearings with coaxial inner and outer races) which is interposed between the first and second flywheels and has at least one row of antifriction rolling elements, and a friction clutch which is operable to receive torque from one of the first and second flywheels with attendant generation of heat. The one flywheel and the friction clutch have cooperating first and second friction- and heat-generating surfaces (the first friction generating surface can constitute one side face or end face of the one flywheel, and the second surface can constitute the exposed surface of one friction lining on a clutch disc forming part of the friction clutch and serving to transmit torque to the input element of the change-speed transmission), and the improved torsion damping apparatus further comprises one or more thermal barriers and/or other suitable means for impeding (preferably blocking) the transfer of heat from the first surface to the bearing means. The impeding means can be installed between the bearing means and the one flywheel. One race of the bearing means can be non-rotatably installed in the one flywheel, and the impeding means (e.g., a thermal barrier) can be mounted between such one race and the one flywheel. The impeding means can contain or can consist of a synthetic plastic material, a metallic material or a ceramic material. For example, the impeding means can contain a duroplast, i.e., a thermosetting resin (e.g., a phenoplast in the form of hard paper). If the impeding means is made of or contains a thermoplastic material, such material can be selected from the group consisting of polytetrafluoroethylene, polyimide and polyamidimide. It is further possible to make the thermal barrier of a material which contains a polycarbonate, especially a fiber-reinforced polycarbonate. The first flywheel can be formed with a central protuberance and the second flywheel is then provided with a centrally located recess which receives at least a portion of the protuberance as well as a portion of or the entire bearing means which then surrounds a portion of or the entire protuberance. The impeding means is or can be mounted in the recess and at least partially surrounds or is surrounded by the bearing means, depending upon whether the recess is provided in the one flywheel or in the other of the first and second flywheels. For example, one race of the bearing means can be arranged to rotate with the one flywheel, and the impeding means can be interposed between such race and the one flywheel so that it rotates with the one flywheel. The other race of the bearing means then surrounds the protuberance of the other of the first and second flywheels. The impeding means can be integral with the bearing means; for example, such impeding means can comprise a thermal barrier which is bonded to the bearing means in an extruding or injecting molding machine. Also, if the thermal barrier contains sintered material, such material can be integral with the bearing means. Alternatively, the thermal barrier can be a press fit on or in the bearing means. it is also possible to assemble the bearing means and the first flywheel into a prefabricated unit which fits, with a certain annular clearance, into a centrally located recess of the second flywheel and such clearance is filled with a mass of plastic material which is allowed to set and can constitute or form part of the impeding means. The hardened plastic material then surrounds the outer race of the bearing means and can be inserted into the centrally located recess of the one flywheel, i.e., of that flywheel which can transmit torque to the input element of the change-speed transmission in response to engagement of the friction clutch. The impeding means can include or constitute a means for sealingly engaging (e.g., surrounding) at least a portion of the bearing means. The impeding means can comprise a ring-shaped thermal barrier including a substantially cylindrical section which overlaps the first race of the bearing means, and at least one radially disposed section which extends from the cylindrical section toward the other race of the bearing means. One of the races surrounds the other race, and the cylindrical section can surround the outer of the two races. The ring-shaped thermal barrier can have a substantially L-shaped cross-sectional outline, and the radially extending section of such thermal barrier can include an annular portion (e.g., an annular marginal portion) which bears against the other race of the bearing means, as considered in the axial direction of the flywheels. The impeding means can comprise two mirror symmetrical rings each of which has an L-shaped cross-sectional outline and whose cylindrical sections surround the outer race of the bearing means. The radial sections of such rings extend from the respective cylindrical sections along the corresponding end faces of the two races, and each radial section thereof can extend across the corresponding end of the annular clearance between the inner and outer races of the bearing means. Thus, the outer race of the bearing means is then disposed between the radial sections of the two rings which constitute or form part of the impeding means. The two rings are mirror symmetrical to each other with reference to a plane which is disposed between them and is normal to the common axis of the flywheels. Each radial section can be biased axially of the flywheels and against the respective end face of the inner race by a diaphragm spring or by other suitable biasing means. The outer marginal portion of each diaphragm spring can react against the one flywheel, and the inner marginal portion of each diaphragm spring then bears against the radial section of the respective ring. Such inner marginal portions can cause the aforediscussed annular lips (if any) of the radial sections to bear against the respective end faces of the inner race. A sleeve-like section of a thermal barrier which constitutes or forms part of the impeding means can be a press fit in the centrally located recess of the first or second flywheel. The sleeve-like section and the bearing means can constitute a prefabricated unit which is received in the recess. The sleeve-like section of the thermal barrier can surround the outer race of the bearing means and its thickness, as considered radially of the flywheels, can vary in the axial direction of the bearing means. At least the thicker portion of the sleeve-like section can be a press fit in the recess of the first or second flywheel. The ring or rings of the thermal barrier can define with one of the races one or more annular chambers for suitable sealing means, such as one or more O-ring. For example, if the thermal barrier comprises a single ring having a substantially L-shaped cross-sectional outline, the cylindrical section of the ring can surround the external surface of the outer race of the bearing means, the radial section of the ring can extend from the cylindrical section inwardly along one end face of the outer race and along the corresponding end face of the inner race, and the annular chamber can be provided at the junction of the two sections, i.e., in the region where the one end face of the outer race meets the peripheral surface of the outer race. The chamber can be formed by providing the outer race of the bearing means with an annular groove. The sealing means (such as the aforementioned O-ring) can be received in the chamber and can be compressed therein by a shoulder of the outer race of the bearing means. The thermal barrier can comprise a ringshaped section having a frustoconical external and/or internal surface in contact with a complementary surface of the one flywheel and/or the outer race of the bearing means. Means (such as the aforementioned diaphragm spring) can be provided to bias the ringshaped section of the thermal barrier axially in the direction of the taper of the ring-shaped section, i.e., so that the larger-diameter end of the frustoconical internal surface or the smaller-diameter end of the frustoconical external surface is the leading end of the ring-shaped section. Such section can constitute a split ring, or it can be assembled of two or more discrete arcuate sections. If the thermal barrier further comprises at least one sealing element, the latter extends radially of the ring-shaped section and toward that race of the bearing means which is not in contact with the cylindrical part of the ring. A diaphragm spring or other means can be provided to bias the sealing element axially against that race which is not engaged by the cylindrical part of the ring, for example, to bias an annular lip of the sealing element against the adjacent race of the bearing means. The ring can include a radial section which is disposed opposite the sealing element and can constitute an integral part of the cylindrical section. The radial section and the sealing element then flank the two races of the bearing means. The means for impeding the transfer of heat to the bearing means can perform the function of or cooperates with the aforementioned damper means which yieldably opposes angular movements of the flywheels relative to each other. The clutch preferably comprises a clutch disc, and the first surface of the one flywheel is adjacent the clutch disc. The clutch also comprises means (e.g., a diaphragm spring) for biasing the first surface of the one flywheel and the clutch disc into frictional engagement with each other when the clutch is engaged whereby the clutch causes the generation of heat which is transmitted to the one flywheel. The opposing means may but need not constitute the only means which tends to resist angular movements of the flywheels relative to each other. The bearing means can comprise an antifriction needle, ball or roller bearing having a race for the rolling elements. The race is adjacent and preferably rotates with the one flywheel, and the opposing means preferably includes a first portion (e.g., the annular portions of two mirror symmetrical rings each of which has a substantially L-shaped cross-sectional outline) which is interposed between the race and the one flywheel, and a second portion (e.g., the radially extending portions of the aforementioned rings) which is in direct or indirect frictional engagement with the other flywheel. The antifriction bearing preferably further comprises a second race which is connected to and shares the angular movements of the other flywheel. The second portion of the opposing means is or can be in direct frictional engagement with the second race. As mentioned above, the second portion of the opposing means can extend substantially radially of the flywheels and of the antifriction bearing, and the first portion of such opposing means preferably extends circumferentially of the race which rotates with the one flywheel. The radially extending portions of the rings preferably abut, or are at least adjacent, the end faces of the second race, i.e., of that race which shares the angular movements of the other flywheel. The opposing means can further comprise one or more dished springs or analogous energy storing means for at least indirectly biasing the second portions of the rings against the other flywheel, e.g., by biasing such second portions axially of the flywheels against the end faces of the race which rotates with the other flywheel. A first portion of each dished spring can react against the one flywheel, and a second portion of each dished spring (such second portions are preferably disposed radially inwardly of the respective first portions) bears against the second portion of the corresponding ring. The distance between the second portions of the dished springs and the axes (e.g., the common axis) of the flywheels preferably equals or approximates the distance between such axes and those parts of the second portions of the rings which bear against the end faces of the second race and/or directly against the other flywheel. The bias of one of the dished springs can exceed the bias of the other dished spring so that the rolling elements of the bearing means are clamped between the two races when the clutch is disengaged in that the second race tends to move axially with reference to the race which rotates with the one flywheel. The force which is required to disengage the clutch and acts axially of the flywheels is opposed by the one dished spring i.e., the force of the one dished spring must be overcome in order to disengage the clutch. The second portions of the rings can further serve as a means for at least substantially sealing the axial ends of the annular space which is defined by the two races of the bearing means and receives the rolling elements. A further feature of the invention resides in the provision of an apparatus wherein the friction clutch has a clutch plate having the aforementioned second surface which is engageable with the (first) surface of the one flywheel. The damping means of such apparatus can comprise two series-connected damping units and one or more friction generating units which are interposed between the flywheels to yieldably oppose rotation of the flywheels relative to each other. The first surface and the bearing means are preferably spaced apart from each other in the radial direction of the flywheels, and the impeding means of such apparatus includes a portion of the one flywheel; to this end, the one flywheel is provided with substantially axially extending passages which are disposed intermediate the bearing means and the first surface, i.e., radially outwardly of the bearing means. At least one passage is or can be elongated, e.g., at least one passage can constitute a slot and the passages preferably form an annulus which surrounds the bearing means. In accordance with a presently preferred embodiment of this apparatus, each passage has a slot-shaped end portion in the first surface, and the cross-sectional area of at least one passage increases in a direction away from the first surface (preferably close to or all the way to an additional surface of the one flywheel opposite the first surface). The arrangement may be such that the internal surfaces which bound some or all of the passages resemble the surfaces surrounding fluid-circulating vanes or blades. The passages are or can be adjacent (particularly closely adjacent) the bearing means (the latter can include one or more radial and/or axial antifriction bearings with a pair of races and needle-, roller- or ball-shaped rolling elements between the races). Those end portions of the passages which are provided in the additional surface of the one flywheel preferably extend substantially radially outwardly away from the bearing means. The just discussed end portions of the passages can extend at least close to or all the way to and even beyond the radially outermost portion of the first surface. The internal surfaces which bound the passages can include inner portions which are nearer to the axes of the flywheels and extend in substantial parallelism with such axes all the way between the first and additional surfaces of the one flywheel, and outer portions which are more distant from the axes of the flywheels and extend in a direction from the first surface and radially of and away from the axes of the flywheels. The passages are, or can be, equidistant from each other in the circumferential direction of the one flywheel, and they preferably form an annulus with its center on the axes of the flywheels. The combined length of the passages (as measured in the circumferential direction of the one flywheel) can be between 20 and 70 percent of the corresponding portion of the one flywheel. The one flywheel comprises webs which alternate with the passages of the aforementioned annulus, and the width of each such web (measured in the circumferential direction of the one flywheel) can be between 0.5 and 2.5 times the width of a passage. The webs can be said to constitute, or they can be designed to constitute, heat barriers between the passages. Such heat barriers are integral portions of the one flywheel, and they cooperate with the streams of air flowing through the passages when the one flywheel rotates to prevent an overheating of the bearing means. The damping means can comprise an annulus of rivets or analogous fasteners which are fixed to the one flywheel and alternate with the passages (as considered in the circumferential direction of the one flywheel). The fasteners can be used to attach a disc- or flange-like output member of the damping means to the one flywheel. The diameter of the annulus which is formed by the passages can closely approximate or equal the diameter of the annulus of fasteners. Such fasteners extend through at least some of the aforementioned web-like heat barriers of the one flywheel. The fasteners can alternate with pairs of passages (as considered in the circumferential direction of the one flywheel). The webs can include wider webs and narrower webs, and the fasteners are preferably secured to the wider webs. The width of each wider web can equal or approximate the combined width of the two narrower webs. The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an axial sectional view of a torsion damping apparatus which is installed in a motor vehicle and wherein the means for impeding the transfer of heat from the friction clutch to one of the flywheels is constructed, assembled and mounted in accordance with a first embodiment of the invention; FIG. 2 is a fragmentary axial sectional view of a second torsion damping apparatus wherein the means for impeding the transfer of heat to the bearing means and one race of the bearing means define two annular chambers for sealing rings; FIG. 3 is a similar fragmentary axial sectional view of a third torsion damping apparatus wherein the means for impeding the transfer of heat to the bearing means includes a single ring with a substantially L-shaped cross-sectional outline and a substantially washer-like sealing element; FIG. 4 is a similar fragmentary axial sectional view of a further torsion damping apparatus wherein the means for impeding the transfer of heat to the bearing means is integral with one of the flywheels and/or with the bearing; FIG. 5 is a fragmentary axial sectional view of an additional apparatus wherein a thermal barrier of the means for impeding the transfer of heat is located radially inwardly of the inner race of the antifriction bearing; FIG. 6 is an axial sectional view of a further torque transmitting apparatus which embodies the invention, the output element of an integral combustion engine and the input element of a change-speed transmission being indicated by phantom lines; FIG. 7 is an enlarged view of a detail within the phantom-line circle Z of FIG. 6; FIG. 8 is a similar enlarged view of a detail in a modified torque transmitting apparatus; FIG. 9 is an axial sectional view of a further apparatus which embodies the invention; and FIG. 10 is a fragmentary transverse sectional view as seen in the direction of arrows from the line X--X of FIG. 9. DESCRIPTION OF THE PREFERRED EMBODIMENTS The torsion damping apparatus 1 of FIG. 1 comprises a composite flywheel 2 including a first flywheel 3 receiving torque from an internal combustion engine 105 by way of a crankshaft 5 which is secured thereto by an annulus of bolts 6 or analogous fasteners, and a second flywheel 4 which transmits torque to the input element 10 of a changespeed transmission 110 in a motor vehicle by way of a friction clutch 7. The friction clutch 7 comprises an axially shiftable pressure plate 8, an axially fixed pressure plate which constitutes the second flywheel 4, a clutch plate or disc 9 with two friction linings 9a, a cover or housing 11 and a diaphragm spring 12 which normally urges the pressure plate 8 against the adjacent lining 9a so that the friction- and heat-generating (second) surface 9b of the other lining 9a bears against the adjacent friction- and heat-generating (first) surface 4a of the flywheel 4. The diaphragm spring 12 is tiltably mounted between two wire-like ring-shaped seats on the cover 11 by rivets 12a, and the axially movable pressure plate 8 is non-rotatably affixed to the flywheel 4 or to the cover 11 by leaf springs 8a. The cover 11 rotates with the flywheel 4 and with the pressure plate 8. The central portion of the clutch disc 9 transmits torque to the input element 10 of the transmission 110. The means for disengaging the clutch 7 can comprise a bearing (not shown) which can act against the radially inwardly extending prongs 12b of the diaphragm spring 12 in order to move the radially outermost portion of the diaphragm spring axially in a direction away from the flywheel 4 so that the leaf springs 8a can move the pressure plate 8 axially and away from the flywheel 4 to thus terminate the torque-transmitting connection between the flywheel 4 and the clutch disc 9, i.e., between the crankshaft 5 and the input element 10. The flywheels 3 and 4 are or can be coaxial and can perform limited or unlimited angular movements relative to each other against the opposition of a composite damper including a damper unit 13, a friction generating unit 13a and a slip clutch 14 which is connected in series with the damper unit 13. The torsion damping apparatus 1 further comprises a bearing means 15 which is interposed between the flywheels 3 and 4 and, in the embodiment of FIG. 1, comprises an antifriction ball bearing 16 with an inner race 19, an outer race 17 spacedly surrounding the inner race 19 and a single row of spherical rolling elements 16a in the bearing clearance between the two races. The outer race 17 is installed in a centrally located seat recess or bore 18 of the flywheel 4, and the inner race 19 is mounted on a centrally located cylindrical stub protuberance or hub 20 which is an integral part of the flywheel 3, which extends axially in a direction away from the crankshaft 5, and at least a portion of which is received in the recess 18. The inner race 19 is a press fit on the protuberance 20 of the flywheel 3 and is held against any axial movement relative to the protuberance 20 by a shoulder 21 of the flywheel 3 as well as by an annular washer-like retaining element 22 which is affixed to the protuberance 20 by screws 23 so that its left-hand end face bears against the end face 20a of the protuberance 20. The improved torsion damping apparatus 1 further comprises means for impeding the transfer of heat from the friction- and heat-generating surfaces 9b, 4a to the bearing means 15. In the embodiment of FIG. 1, the heat transfer impeding means includes a thermal insulator or barrier 24 which is installed between the outer race 17 of the antifriction bearing 16 and the adjacent portion of the flywheel 4, namely that portion of the flywheel 4 which directly surrounds the recess 18 therein. The construction, composition and mounting of the thermal barrier 24 are such that it at least strongly interferes with and appreciably reduces the transfer of heat from the clutch disc 9 to the antifriction bearing 16. This reduces the likelihood of excessive thermal stressing of the lubricant (e.g., grease) for the antifriction bearing 16 as well as the likelihood cf excessive thermally induced distortion (expansion) of the antifriction bearing 16 which could result in jamming of spherical rolling elements 16a between the races 17 and 19. The diameter of the recess 18 in the central portion of the flywheel 4 is selected in such a way that the recess can receive the outer race 17 of the antifriction bearing 16 as well as the components of the thermal barrier 24. In other words, the diameter of the recess 18 exceeds the outer diameter of the outer race 17. The illustrated thermal barrier 24 comprises two rings 25, 26 which are mirror symmetrical to each other with reference to a plane that is disposed between them and is normal to the axes of the flywheels 3, 4 and antifriction bearing 16. Each of the rings 25, 26 has a substantially L-shaped cross-sectional outline with a cylindrical section 25a, 26a which surrounds the external surface of the outer race 17 and a radially inwardly extending washer-like section 25b, 26b which extends along the respective end face of the outer race 17 and toward and along the respective end face of the inner race 19. The radially innermost annular portions or lips of the radial sections 25b, 26b bear axially against the respective end faces of the inner race 19. Thus, the sections 25b, 26b constitute sealing elements which reduce the likelihood of penetration of foreign matter into the annular bearing clearance between the races 17, 19 as well as the likelihood of escape of lubricant from such clearance. The sealing action of radial sections 25b, 26b of the rings 25, 26 is enhanced by discrete means for biasing the radially innermost portions of such radial sections against the adjacent end faces of the inner race 19. The biasing means comprises two diaphragm springs 27, 28. The radially outermost portion of the diaphragm spring 27 reacts against a shoulder provided therefor on a disc 30 which is affixed to the flywheel 4 by rivet-shaped distancing elements 29, and the radially innermost portion of the diaphragm spring 27 bears against the radially innermost portion of the radial section 25b of the ring 25. The radially outermost portion of the diaphragm spring 28 reacts against a shoulder of the flywheel 4, and its radially innermost portion bears against the radially innermost portion of the radial section 26b of the ring 26. In order to simplify and facilitate the assembly of the antifriction bearing 16 with the flywheels 3 and 4, the cylindrical sections 25a, 26a of the rings 25, 26 are forcibly fitted onto the outer race 17 of the antifriction bearing 16 in a first step before the bearing 16 and the rings 25, 26 thereon are forcibly inserted into the recess 18 of the flywheel 4. The bearing 16 and the rings 25, 26 are thereupon additionally secured against axial movement relative to the flywheel 4 in that the radial section 26b of the ring 26 bears against an internal shoulder 31 of the flywheel 4 and the radial section 25a of the ring 25 is caused to abut against the disc 30 which, as mentioned above, is affixed to the flywheel 4 by the distancing elements 29. The damper unit 13 includes the disc 30 and a second disc 33 which is held at a fixed distance from the disc 30 by the aforementioned rivet-shaped distancing elements 29 which are anchored in the flywheel 4. The shanks of such distancing elements extend through a flange 32 which is disposed between the discs 30 and 33. The discs 30, 33 cannot rotate relative to each other and share all angular movements of the flywheel 4. The flange 32 shares all angular movements of the flywheel 3. The discs 30, 33 and the flange 32 are provided with neighboring windows for energy storing devices in the form of circumferentially acting coil springs 34 which oppose angular movements of the flywheels 3 and 4 relative to each other, i.e., such coil springs resist angular movements of the discs 30, 33 with reference to the flange 32 and vice versa. The composite damper further includes the friction generating unit 13a which is active during each and every stage of angular movement of the flywheel 3 relative to the flywheel 4 and/or vice versa. The friction generating unit 13a acts axially between the disc 30 on the flywheel 4 and the flywheel 3, and includes an energy storing member in the form of a diaphragm spring 35 which is installed in prestressed condition between the disc 30 and a pressure applying washer 36. The diaphragm spring 35 can react against the flywheel 3 to bear against the washer 36 which, in turn, urges a friction ring 37 against the flywheel 3. The axial stress which is applied by the diaphragm spring 35 is taken up by the antifriction bearing 16. The flange 32 constitutes the input element of the damper unit 13 as well as the output element of the slip clutch 14. The input element of the slip clutch 14 is constituted by two discs 38, 39 which are maintained at a fixed axial distance from each other and are non-rotatably secured to the flywheel 3. The means for non-rotatably securing the disc 39 to the flywheel 3 comprises an annulus of rivets 40. The disc 38 is provided with an annulus of axially extending peripheral fingers or lugs 38a which extend into adjacent peripheral notches 41 of the disc 39 so that the two discs are held against angular movement relative to one another. The flange 32 has radially outwardly extending arms 42 which are clamped between the discs 38 and 39 by a diaphragm spring 43 which urges the discs 38 and 39 toward each other. The diaphragm spring 43 reacts against the flywheel 3 and bears against the disc 38 in a direction to urge the latter axially toward the disc 39. The arms 42 of the flange 32 alternate with windows which are provided in the discs 38, 39 and receive energy storing devices in the form of coil springs 44 which can be engaged by the respective arms 42 and constitute stops that determine the extent of angular displacement of the parts of the slip clutch 14 relative to each other. It has been found that the thermal barrier 24 between the friction clutch 7 and the bearing means 15 is capable of prolonging the useful life of the bearing means as well as of ensuring more satisfactory operation of the damper (13, 13a, 14) between the flywheels 3 and 4. This is due to the fact that the thermal barrier 24 greatly reduces the transfer of heat to the bearing means 15 even though it takes up little room and is assembled of a small number of simple, compact and inexpensive parts each of which can be mass-produced in available machinery. Extensive experiments with the improved torsion damping apparatus (wherein the bearing means is installed directly between the two flywheels 3 and 4 and wherein the angular movements of the flywheels relative to each other must be damped by one or more discrete or interlinked dampers) indicate that, in the absence cf any preventive or precautionary measures, heat energy which is released when the friction clutch 7 is engaged subjects the bearing means between the flywheels to very pronounced thermal stresses which entail unsatisfactory operation and frequently rapid destruction of the bearing means as well as unsatisfactory operation of the damper or dampers. The likelihood of rapid destruction of the bearing means is especially pronounced if the bearing clearance or tolerance between the inner and outer races is small or very small. Repeated pronounced heating and cooling of the parts of such bearing means entails substantial thermally induced expansion and contraction whereby the rolling elements between the two races are likely to seize in response to expansion cf the races which, in turn, entails rapid destruction of the rolling elements and of the tracks which are machined into the races. All this can be avoided by the advent of the present invention, i.e., by the provision of a thermal barrier which at least impedes the transfer of heat to the bearing means. Another important advantage of the improved apparatus is that the lubricant (such as oil or grease) in the bearing clearance between the races of the bearing is much less likely to be overheated and to escape from the bearing. This, too, contributes to longer useful life of the bearing means and of the entire torsion damping apparatus. Moreover, portions or sections of the rings 25, 26 which constitute or form part of the improved thermal barrier 24 can serve as an effective means for sealing the bearing clearance between the races 17 and 19 to thereby even further reduce the likelihood of escape of excessive quantities of lubricant from the interior of the antifriction bearing 16. The aforediscussed plastic, ceramic and/or metallic materials have been found to constitute highly satisfactory thermal insulators which can protect the antifriction bearing 16 and the units of the composite damper for extended periods of time, even if the friction clutch 7 is continuously engaged and/or is caused or permitted to slip (with attendant pronounced generation of heat) at frequent and relatively long intervals. It was further ascertained that the placing of the thermal barrier directly between the antifriction bearing 16 and the adjacent portion of the flywheel 4 (i.e., of that flywheel which is directly heated by the friction clutch 7) contributes significantly to adequate shielding of the bearing means 15 from excessive heat while, at the same time, allowing for relatively simple and inexpensive installation of the thermal barrier in the torsion damping apparatus. Of course, it is equally possible to employ two or more thermal barriers or to provide one or more thermal barriers in the body of the flywheel 4 and out of direct contact with the antifriction bearing 16 but in the path of transfer of heat energy from the friction generating surfaces 9b, 4a to the bearing 16. The positions of the recess 18 and protuberance 20 can be reversed, i.e., the protuberance can be provided on the central portion of the flywheel 4 and the flywheel 3 is then formed with a recess which receives at least a portion of the protuberance on the flywheel 4, at least a portion of the bearing means on such protuberance and at least a portion of the thermal barrier. The thermal barrier is then preferably installed within the inner race (which surrounds the protuberance of the flywheel 4) in order to prevent overheating of the bearing means 15. This is shown in FIG. 5. The thermal barrier 24 of FIG. 1 can be replaced with a thermal barrier which comprises a single ring having a cylindrical section which surrounds the major portion of or the entire outer race 17, and a radial section which is adjacent one end face of the race 17 and extends radially inwardly toward and at least in part along one end face of the inner race 19. The illustrated two-piece thermal barrier 24 is preferred in many instances because the two radially extending sections 25b, 26b constitute effective and relatively simple as well as compact sealing elements which prevent the escape of lubricant from the bearing clearance for the rolling elements 16a and also reduce the likelihood of overheating of the confined lubricant and/or rolling elements. The provision of biasing means (such as the aforementioned diaphragm springs 27 and 28) even further reduces the likelihood of escape of excessive quantities of lubricant and/or of overheating of the lubricant and/or rolling elements in the bearing clearance between the races 17 and 19. The diaphragm springs 27, 28 can be provided even if the sections 25b and 26b are elastically deformable and the rings 25, 26 are installed in such a way that the sections 25b, 26b are prestressed and bear against the respective end faces of the inner race 19 even if the diaphragm springs 27, 28 are omitted; however, these diaphragm springs are then optional. FIG. 2 shows a portion of a modified torsion damping apparatus with coaxial flywheels 3, 4, a modified bearing means having an antifriction ball bearing 116 between the two flywheels, and a modified thermal barrier between the antifriction bearing 116 and that portion of the flywheel 4 which is immediately adjacent the outer race 117 of the bearing 116. Such portion of the flywheel 4 has a recess 118 which receives a portion of the outer race 117 as well as portions of two mirror symmetrical insulating rings 125, 126 which constitute component parts of the thermal barrier. The inner race 119 of the antifriction bearing 116 is a press fit on the protuberance or hub 120 of the flywheel 3. The manner in which the flywheel 4 cooperates with the friction clutch (not shown in FIG. 2), and the manner in which the flywheel 3 receives torque from the crankshaft of the engine is or can be the same as shown in FIG. 1. The outer race 117 of the antifriction bearing 116 has circumferentially extending annular chambers in the form of grooves or recesses 117a, 117b which are overlapped in part by the cylindrical sections 125a, 126a and in part by the inwardly extending radial sections 125b, 126b of the respective rings 125, 126. Each of these rings has a substantially L-shaped cross-sectional outline, the cylindrical sections 125a, 126a engage with the peripheral surface of the outer race 117, and the radial sections 125b, 126b extend radially inwardly along the respective end faces of the races 117, 119 and have radially innermost annular portions or lips 125c, 126c which are biased axially against the adjacent end faces of the inner race 119 by two diaphragm springs 127, 128 which respectively react against the disc 130 and flywheel 4 and bear against the adjacent lips 125c, 126c. The disc 130 has a shoulder for the radially outermost portion of the diaphragm spring 127, and the flywheel 4 has a shoulder for the radially outermost portion of the diaphragm spring 128. The chambers 117a, 117b respectively receive discrete sealing means in the form of O-rings 145, 146 which cooperate with the lips 125c, 126c and diaphragm springs 127, 128 to prevent penetration of foreign matter into the bearing clearance between the races 117, 119 as well as to prevent the escape of lubricant (e.g., grease) from such clearance. The dimensions of the chambers 117a, 117b and of the O-rings 145, 146 are selected in such a way that the O-rings are at least slightly compressed so as to reliably prevent the escape of lubricant from the clearance for the rolling elements of the antifriction bearing 116. FIG. 2 further shows that the thickness of the intermediate portion of each of the radial sections 125b, 126b is less than the thickness of the radially outermost or the radially innermost (125c, 126c) portion of each such section. This enhances the elasticity of the radial sections 125b, 126b and enables the diaphragm springs 127, 128 to reliably hold the lips 125c, 126c in sealing contact with the adjacent end faces of the inner race 119. The cylindrical sections 125a, 126a can be a press fit in the recess 118 of the flywheel 4, and they can be assembled with the outer race 117 of the antifriction bearing 116 before the latter is fitted onto the protuberance 120 and before the protuberance 120 is introduced into the recess 118. The diaphragm spring 127 and/or 128 can be omitted if the corresponding radial section 125b and/or 126b is sufficiently elastic to adequately bear against the respective end face of the inner race 119 when the antifriction bearing 116 is properly mounted on the protuberance 120 of the flywheel 3 and is adequately received in the recess 118 of the flywheel 4. The same applies for the radial sections 25b, 26b of the rings 25, 26 and for the diaphragm springs 27, 28 of the apparatus 1 which is shown in FIG. 1. Thus, all that is necessary is to make the rings 25, 26 and/or 125, 126 of a suitable elastomeric material and to mount these rings in such a way that their radial sections 25b, 26b and/or 125b, 126b are elastically deformed in fully assembled condition of the respective apparatus to adequately bear against the inner race 19 or 119 and to thus prevent escape of lubricant from the clearance between the races 17, 19 or 117, 119. The O-rings 145 and 146 even further reduce the likelihood of escape of lubricant from the bearing clearance between the races 117 and 119, even if the lubricant is subjected to the action of very pronounced centrifugal forces. Referring to FIG. 3, there is shown a portion of a further torsion damping apparatus wherein the antifriction bearing 216 between the coaxial flywheels 3 and 4 has an outer race 217 with a frustoconical external or peripheral surface 217' abutting against a complementary frustoconical internal surface 225a' of the tubular section 225a of a split ring-shaped thermal barrier 225. The section 225a has a frustoconical external surface 225a" whose taper is counter to that of the internal surface 225a' and which is in contact with a complementary frustoconical surface in the recess 218 of the flywheel 4. The illustrated section 225a can be replaced with a section having a cylindrical internal surface and a frustoconical external surface or vice versa. The external surface of the outer race 217 or the surface in the recess 218 is then a cylindrical surface. The diaphragm spring 227 reacts against the disc 230 and biases the ring-shaped thermal barrier 225 in the direction of taper of its frustoconical surfaces 225a', 225a", i.e., in a direction to cause the section 225a to penetrate deeper into the recess 218. The thermal barrier of FIG. 3 further comprises a first sealing element 226 which is a separately produced washer and extends radially inwardly from the thinnest portion of the cylindrical section 225a along the right-hand end faces of the races 217, 219 and carries at its radially innermost end an annular lip 226c which is biased against the right-hand end face of the race 219 due to innate elasticity of the sealing element 226 or due to the provision of a suitable diaphragm spring (not specifically shown). The radially inwardly extending section 225b of the ring-shaped thermal barrier 225 constitutes a second washer-like sealing element which is adjacent the left-hand end faces of the races 217, 219 and has a radially innermost portion in the form of an annular lip bearing against the adjacent end face of the race 219 under the action of the diaphragm spring 227, i.e., because the spring 227 urges the cylindrical section 225a deeper into the recess 218 of the flywheel 4. The disc 230 is affixed to the flywheel 4, e.g., in a manner as described for the disc 30 of FIG. 1. The sealing elements 226 and 225b flank the antifriction bearing 216 and reduce the likelihood of escape of lubricant from the annular clearance for the rolling elements of the bearing 216. Portions of the sealing elements 226, 225b have reduced thicknesses (see the portion 226b) to enhance their elasticity and to further reduce the likelihood of uncontrolled escape of lubricant from the clearance for the rolling elements. In lieu of spheres, the antifriction bearing 16, 116 or 216 can also employ barrel-shaped or needle-like rolling elements without departing from the spirit of the invention. Furthermore, the antifriction bearing can be provided with two or more rows of antifriction rolling elements. The material of the ring-shaped thermal barrier 225 and of the sealing element 226 is preferably a good insulator of heat. The torsion damping apparatus which embodies the structure of FIG. 3 exhibits the advantage that the frustoconical parts 217 and 225 compensate for certain machining tolerances and ensure automatic centering of the antifriction bearing 216 and thermal barrier when the diaphragm spring 227 is caused to bear against the left-hand side of the cylindrical section 225a and radial section or sealing element 225b. Moreover, the structure which is shown in FIG. 3 can automatically compensate for wear upon the parts of the antifriction bearing 216, upon the ringshaped part 225 of the thermal barrier as well as upon the sealing element 226. The spring 227 ensures that the cylindrical section 225a is wedged in the recess 218 of the flywheel 4, that the outer race 217 is wedged in the cylindrical section 225a, and that the sealing element 226 is adequately held between the outer race 217 and the adjacent shoulder 231 of the flywheel 4 as well as that its lip 226c sealingly engages the right-hand end face of the inner race 219. The provision of a split ring 225 even further ensures adequate wedging of the parts 225, 217 in the recess 218 of the flywheel 4. It is further within the purview of the invention to provide the improved torsion damping apparatus with a thermal barrier which need not include any prefabricated parts in the form of rings and/or washer-like sealing elements. For example, and as shown in FIG. 4, the thermal barrier 324 can constitute a single piece of thermoplastic or thermosetting material which is injected into the recess 318 of the flywheel 4 around the outer race 317 of the antifriction bearing 316. All that is necessary is to dimension the outer race 317 and the recess 318 in such a way that the surfaces bounding the recess and the surfaces bounding the outer race define an annular space or compartment which can receive flowable plastic material. When the plastic material sets, the resulting thermal barrier 324 adequately fills the space between the race 317 and the surfaces surrounding the recess 318 and impedes or totally prevents the transfer of heat from the clutch disc (not shown) to the antifriction bearing 316. The illustrated plastic thermal barrier 324 can be replaced with a barrier which consists of sintered ceramic or metallic material. In each instance, the thermal barrier is an integral part of the antifriction bearing 316 and/or of the flywheel 4. It is also possible to apply an integral plastic, ceramic or metallic thermal barrier to the inner race and/or outer race of the antifriction bearing 316 before the latter is inserted into the recess 318 or to apply the thermal barrier to the surfaces bounding the recess 318 (so that the thermal barrier becomes an integral part of the flywheel 4) before the antifriction bearing 316 is inserted into the thus obtained thermal barrier in the recess 318. The injection or another mode of introduction of a flowable plastic, metallic or ceramic material into the space between the surfaces bounding the recess 318 of the flywheel 4 and the exterior of the antifriction bearing 316 is especially advantageous and desirable if he bearing 316 is a commercially available antifriction bearing which is already provided with sealing elements 360 that prevent uncontrolled escape of lubricant from the space between the two races. As mentioned above, all that is necessary is to adequately select the dimensions of the surfaces bounding the recess 318 so as to provide sufficient room for introduction of a flowable material which is to form the thermal barrier 324 and is to be integral with the outer race 317 and/or with the flywheel 4. The disc 330 is applied subsequent to introduction of the outer race 317 into the recess 318, and the disc 320 is attached to the flywheel 3 to hold the inner race 319 against axial movement. Referring to FIGS. 6 and 7, there is shown an apparatus 401 which transmits torque from a rotary output element 405 (such as the crankshaft of an internal combustion engine in a motor vehicle) to a rotary input element 410 (e.g., the input shaft of a change-speed transmission in a motor vehicle). In order to render it possible to absorb shocks which develop during transmission of torque, the apparatus 401 comprises a composite flywheel 402 having two coaxial flywheels 403 and 404 which have limited or full freedom of angular movement relative to each other. The flywheel 403 is coaxially secured to the output element 405 by a set of bolts 406 or by other suitable fasteners. The flywheel 404 can transmit torque to the input element 410 by way of a friction clutch 407 whose housing or cover 411 is secured to the flywheel 404 by bolts, screws or like fasteners, not shown. The clutch 407 further comprises a pressure plate 408, a clutch disc 409 whose linings are disposed between a radially extending surface 404a of the flywheel 404 and the pressure plate 408 and whose hub is non-rotatably affixed to the input element 410, and a diaphragm spring 412 which reacts against the cover 411 and bears against the pressure plate 408 to bias the latter against the respective friction lining whereby the other friction lining bears against the surface 404a and the flywheel 404 rotates the input element 410 as long as the friction clutch 407 remains engaged. The diaphragm spring 412 is installed between two ring-shaped seats in the form of wire rings which are supported by the cover 411. A damper 413 is installed between the flywheels 403 and 404 to yieldably oppose the aforementioned angular movements of the flywheels relative to each other. The apparatus 401 further comprises antifriction bearing means 414 here shown as comprising a ball bearing 415 with a single row of spherical rolling elements 415a between an outer race 416 and an inner race 418. The race 416 extends into an internal annular groove 417 of the flywheel 404, and the race 418 surrounds a hub-shaped central portion or protuberance 419 of the flywheel 403. The protuberance 419 extends axially of the flywheel 404 in a direction away from the output element 405. The inner race 418 is a press fit on the protuberance 419 and is held against axial movement on such protuberance by a radially outwardly extending shoulder 420 of the flywheel 403 in cooperation with a washer-like retainer 421 which abuts the adjacent end face 422 of the protuberance 419 and is separably affixed to the latter by screws 423 or by analogous fastener means. In accordance with a feature of the embodiment of FIGS. 6 and 7, the apparatus 401 further comprises a thermal barrier 424 which is interposed between the race 416 of the ball bearing 415 and the flywheel 404 so as to impede or fully prevent the transmission of heat which is generated primarily as a result of frictional engagement of the clutch plate 409 with the surface 404a of the flywheel 404 when the friction clutch 407 is operative to transmit torque from the flywheel 404 to the input element 410 of the change-speed transmission. The purpose of the thermal barrier 424 is to prevent heat, which is generated in response to engagement of the friction clutch 407, from adversely influencing (i.e., from exerting excessive thermal stresses upon) the lubricant (grease) which is used for the rolling elements 415a of the ball bearing 415. Furthermore, the barrier 424 prevents excessive thermally induced deformation and radial expansion of the bearing 415 when the left-hand lining of the clutch disc 409 is in frictional engagement with the surface 404a of the flywheel 404. Excessive radial expansion of the races 416 and 418 could entail a jamming of the rolling elements 415a between the races. The diameter of the surface in the deepmost portion of the recess 417 in the flywheel 404 is selected in such a way that certain parts of the thermal barrier 424 can be installed in such recess and surround the outer race 416 of the antifriction bearing 415. As can be best seen in FIG. 7, the thermal barrier 424 comprises two substantially or exactly mirror symmetrical rings 425, 426 each of which has a substantially L-shaped cross-sectional outline. The axially extending (annular) portions or legs 425a, 426a of the rings 425, 426 are radially outwardly adjacent the outer race 416 of the ball bearing 415, and the radially inwardly extending (washer-like) portions or legs 425b, 426b of these rings flank the respective end faces of the race 416 and have radially innermost parts or lips 434, 435 which abut the respective end faces 437, 438 of the inner race 418 to thereby oppose angular movements of the race 418 and flywheel 403 relative to the race 416 and flywheel 404. Thus, the lips 434, 435 form part of the thermal barrier 424 as well as of the aforementioned damper 413 between the flywheels 403 and 404. The radially extending legs 425b, 426b of the rings 425, 426 perform the additional function of confining the lubricant (normally grease) for the rolling elements 415a in the space between the races 416 and 418 of the ball bearing 415. The damping and confining or sealing action of the legs 425b, 426b can be enhanced and maintained at a selected optimum value or within a predetermined optimum range by the provision of means for biasing the lips 434, 435 against the respective end faces 437, 438 of the inner race 418. Such biasing means comprises a first dished spring 427 whose radially outermost portion reacts against an internal shoulder 430a of a disc 430 and whose radially innermost portion bears against the lip 434 of the leg 425b, and a second dished spring 428 whose radially outermost portion reacts against an internal shoulder 431 of the flywheel 404 and whose radially innermost portion bears against the lip 435 of the leg 426b. The disc 430 is affixed to the flywheel 404 by a set of rivets 429. FIG. 7 shows that the thickness of the median portions of the legs 425b, 426b is reduced so that such median portions constitute two relatively thin and hence more readily flexible membranes 432, 433. The lips 434, 435 are disposed radially inwardly of the respective membranes 432 and 433 and bear against the respective end faces 437 and 438 of the inner race 418 with a force which is determined by the bias of the respective dished springs 427 and 428. The initial stressing of the dished springs 427 and 428 is selected in such a way that the axially oriented force which is applied by the spring 428 exceeds the axially oriented force which is applied by the spring 427. This ensures that the races 416 and 418 tend to move axially and in opposite directions whenever the friction clutch 407 is idle whereby the rolling elements 415a are clamped between the two races. The inner race 418 tends to move to the left, as viewed in FIG. 7, because the bias of the dished spring 428 prevails over that of the dished spring 427. In order to simplify the assembly of the thermal barrier 424 with the antifriction bearing 415, the annular portions 425a, 426a of the rings 425, 426 are first force-fitted onto the peripheral surface of the outer race 416 before the rings 425, 426 are introduced into the recess 417 of the flywheel 404. The antifriction bearing 415 is maintained in a predetermined axial position with reference to the flywheel 4 because the outer side of the properly installed radially extending leg 426b abuts an internal shoulder 431a of the flywheel 404 and the radially outermost portion of the outer side of the leg 425b abuts the adjacent side of the aforementioned disc 430. The damper 413 between the flywheels 403 and 404 further comprises the aforementioned disc 430 as well as a second disc 440 whose inner diameter is larger than that of the disc 430. The rivets 429 are configurated in such a way that they maintain the discs 430, 440 at a fixed axial distance from the surface 404a of the flywheel 404 as well as from each other. The discs 430, 440 flank (i.e., they are disposed at the opposite sides of) a flange 439 whose radially outwardly extending prongs 439a are secured to the flywheel 403 by rivets 442. The flange 439 and the discs 430, 440 have registering windows for energy storing elements in the form of coil springs 441 whose function is to oppose angular movements of the discs 430, 440 and flange 439 relative to each other. The arrow 443 denotes in FIG. 6 the direction in which the tips of the radially inwardly extending fingers of the diaphragm spring 412 must be shifted in order to move the radially outermost portion of the diaphragm spring axially and away from the flywheel 404 in order to disengage the friction clutch 407. The force which is applied in the direction of the arrow 443 must overcome the force with which the prestressed spring 412 urges the pressure plate 408 against the respective friction lining of the clutch disc 409. The bias of the springs 427, 428 is selected in such a way that the resulting axial force acting upon the race 418 (namely the difference between the axially applied larger force of the spring 428 and the axially applied smaller force of the spring 427) is smaller than the force which must be applied in the direction of the arrow 443 in order to disengage the clutch 407. This ensures that the spring 428 ceases to urge the inner race 418 axially relative to the outer race 416 when the friction clutch 407 is engaged to transmit torque from the flywheel 404 to the input element 410 of the change-speed transmission. In other words, the rolling elements 415a are not clamped between the races 416 and 418 when the flywheels 403, 404 are to transmit torque from the output element 405 to the input element 410. The just discussed selection of the bias of the springs 412, 427, 428 and of the force which must be applied in the direction of he arrow 443 is desirable and advantageous because this ensures that the rolling elements 415a come into contact with different portions of the tracks which are defined by the races 416 and 418 and also that the angular positions of the rolling elements 415a change with attendant reduction of pronounced localized wear upon the antifriction bearing 415 and the longer useful life of the torque transmitting apparatus 401. The extent to which the flywheels 403 and 404 can turn relative to each other is determined by the length of circumferentially extending slots in the flange 439. Such slots receive portions of the respective rivets 429. FIG. 8 shows a portion of a modified torque transmitting apparatus wherein the dished spring 527 which bears upon the bead 534 reacts against the corresponding end face of the outer race 516 and urges the bead 534 against a friction generating washer 503b so that the latter bears against a shoulder 503a of the flywheel 503. Thus, the spring 527 is disposed between the median portion or membrane of the radially extending leg 525b of the ring 525 and the respective end faces of the races 516 and 518. The washer 503b can be made of steel and is preferably mounted in such a way that it cannot rotate relative to the flywheel 503. The construction which is shown in FIG. 8 ensures that the axially oriented force which is generated by the spring 527 is added to the axially oriented force which is generated by the spring 528 so as to urge the inner race 518 axially of the outer race 516 when the friction clutch (not shown in FIG. 8) is disengaged i.e., the races 516 and 518 then clamp the rolling elements 515a of the antifriction bearing 515. The leg 525b is integral with the axially extending annular leg 525a of the ring 525. The ring 526 has an axially extending portion 526a and the radially extending leg 526b with bead 535. The rings 525, 526 are installed in the flywheel 504. An important advantage of the torque transmitting apparatus of FIGS. 6-8 is that the thermal barrier 424 of FIGS. 6-7 or the barrier of FIG. 8 can also serve as (or as a component part of) a means for opposing angular movements of the flywheels 403 and 404 or 503 and 504 relative to each other. This contributes to simplicity, compactness and lower cost of the apparatus. The rings 425, 426 or 525, 526 and the springs 427, 428 or 527, 528 can constitute the sole means for frictionally damping the angular movements of the flywheel 403 or 503 relative to the flywheel 404 or 504 and/or vice versa. This entails a substantial reduction of the overall number of component parts of the torque transmitting apparatus and simplifies the assembly and/or dismantling of such apparatus. If the improved thermal barrier 424 or the barrier of FIG. 8 constitutes the sole means for frictionally damping the angular movements of the flywheels 403 or 503 and 404 or 504 relative to each other, the conventional damper or dampers can be omitted in their entirety. On the other hand, if the apparatus comprises one or more conventional dampers plus the thermal barrier which also serves as or includes a means for opposing angular movements of the flywheels 403, 404 or 503, 504 relative to each other, the damping action can be enhanced by a unit (the improved torque transmitting apparatus) which also performs another important, desirable and advantageous (thermal insulating) function. It has been found that the improved thermal barrier (either alone or in combination with one or more conventional dampers) can ensure an ideal or nearly ideal progress of the damping action. Proper thermal insulation of the lubricant (normally grease) in the annular space between the races 416, 418 or 516, 518 of the antifriction bearing 415 or 515 contributes significantly to a longer useful life of the entire apparatus, and such insulation also reduces the need for frequent inspection of the bearing. Proper lubrication of the tracks which are defined by the races 416, 418 or 516, 518 and of the rolling elements 415a or 515a is one of the most important factors insofar as the useful life of the bearing means (and hence of the entire torque transmitting apparatus) is concerned. The apparatus of FIGS. 6-8 can be simplified still further by omitting the spring 427 and/or 428 of FIGS. 6-7 and/or the spring 527 and/or 528 of FIG. 8. All that is necessary is to ensure that the rings 425, 426 or 525, 526 are made of a material which exhibits a requisite degree of springiness so that the radially extending arms 425b, 426b or 525b, 526b bear against the respective end faces of the race 418 or 518 and/or directly against the flywheel 403 and/or against a part (such as 503b) which rotates with the flywheel 503 when the improved thermal barrier is properly installed between the friction clutch and the bearing 415 or 515, normally between the flywheel 404 or 504 and the respective race (416 or 516) of the bearing means. The utilization of dished springs or otherwise configurated biasing means is often preferred because such springs ensure a more predictable generation of friction between the ring or rings of the thermal barrier and the flywheel 403 or 503. The springs 427, 428 or FIG. 7 further ensure an even more reliable sealing of both axial ends of the annular space which is defined by the races 416, 418 and serves for reception of the rolling elements 415a. The improved thermal barrier can operate satisfactorily with a single ring 425, 525 or 426, 526. The utilization of two rings is preferred at this time because two rings ensure a more satisfactory sealing of the aforediscussed annular space between the races 416, 418 or 516, 518, because two rings can establish a highly satisfactory thermal barrier between the flywheel 404 or 504 and the bearing 415 or 515, and also because two rings (especially when used with two discrete dished springs or the like) can provide a highly satisfactory damping action by opposing the angular movements of the flywheels 403, 404 or 503, 504 relative to each other. FIGS. 9 and 10 show an apparatus 601 for controlled transmission of torque from the crankshaft 605 (indicated by phantom lines) of the internal combustion engine to the input shaft 610 (shown by phantom lines) of the change-speed transmission in a motor vehicle. The apparatus 601 comprises a composite flywheel 602 including coaxial first and second components 603, 604 which are rotatable relative to each other within predetermined limits. The component 603 is coaxially secured to the crankshaft 605 by a set of bolts 606, and the component 604 carries the housing or cover 611 of a friction clutch 607 whose clutch disc or clutch plate 609 has a hub which is non-rotatably secured to the input shaft 610. The component 603 drives the input shaft 610 in response to engagement of the clutch 607 in a manner not forming part of the present invention. FIG. 9 shows an axially movable pressure plate 608 which is normally biased toward the component 604 by a diaphragm spring 612 tiltably mounted at the inner side of the housing 611. The clutch plate 609 carries linings which are in frictional engagement with the adjacent surface of the pressure plate 608 and with an annular friction surface 604a of the component 604 when the clutch 607 is engaged, namely when the component 603 drives the input shaft 610 through the medium of the component 604 and clutch plate 609. The apparatus 601 further comprises means for yieldably opposing angular movements of the components 603 and 604 relative to each other. Such opposing means comprises a first damping unit 613, a second damping unit 614 in series with the unit 613, and a friction generating device 613a. The exact construction of the units 613, 614 and friction generating device 613a forms no part of the present invention. Reference may be had to the aforementioned copending applications of the assignee and to the embodiments of FIGS. 1-8. The apparatus 601 still further comprises bearing means 615 including at least one radial antifriction bearing 616 having an outer race 617, an inner race 619 and an annulus of spherical rolling elements 616a between the two races. The outer race 617 is disposed in an axial recess or bore 618 of the component 604, and the inner race 619 is preferably a press-fit on a centrally located cylindrical protuberance 620 of the component 603. The protuberance 620 extends axially in a direction away from the crankshaft 605 and into the bore 618 of the component 604. The inner race 619 abuts a stop in the form of a shoulder 621 of the protuberance 620 and is held against axial movement away from such shoulder by a disc-shaped retainer 622 which is secured to the adjacent end face 620a of the protuberance 620 by a set of screws 623 or other suitable fasteners. The apparatus 601 also comprises a number of means for impeding or preventing the transmission of heat between the friction surface 604a and the radial antifriction bearing 616. The latter is disposed radially inwardly of the friction linings on the clutch plate 609. One of the heat transmission preventing or impeding means comprises a thermal barrier 624 composed of two coaxial rings 625 and 626 each having a substantially L-shaped cross-sectional outline. The axially extending (cylindrical) portions 625a, 626a of the rings 625, 626 surround the major part of the external surface of the outer race 617 and are received in the bore 618 of the second component 604. The radially extending (washer-like) portions 625b, 626b of the rings 625, 626 are adjacent the respective end faces of the races 617, 619 and are biased against the corresponding end faces of the inner race 619 by energy storing elements in the form of diaphragm springs 627, 628, respectively. The radially extending portions 625b, 626b not only intercept some of the heat but also serve to seal the space between the races 617, 619 so as to prevent uncontrolled escape of grease for the rolling elements 616a. The radially outermost portion of the diaphragm spring 627 reacts against a shoulder of a disc 630 which is affixed to the component 604 by rivets 629, and the radially innermost portion of the spring 627 bears against the radially innermost part of the portion 625b. The diaphragm spring 628 has a radially outermost portion which reacts against an internal shoulder of the component 604 and a radially innermost portion which bears against the radially innermost part of the portion 626b. The diameter of the surface surrounding the bore 618 is sufficiently large to allow for the placing of rings 625, 626 onto the outer race 617 in a manner as shown in FIG. 9. The material of the rings 625, 626 is selected in such a way that they constitute a thermal insulator which impedes the transfer of heat between the friction surface 604a of the component 604 and the radial bearing 616. The bearing 616 is held against axial movement relative to the component 604 by the rings 625, 626 in that the ring 625 abuts the disc 630 and the ring 626 abuts an internal shoulder 631 of the component 604. As mentioned before, the rivets 629 fix the disc 630 to the component 604. The damping unit 613 comprises the aforementioned disc 630 and a second disc 633. The discs 630, 633 are disposed at the opposite sides of a flange 632 and are held (by the rivets 629) against axial movement relative to each other and relative to the component 604. The flange 632 has windows (not specifically referenced) which register with windows in the discs 630, 633 and serve to receive energy storing elements in the form of coil springs 634. The coil springs 634 yieldably oppose angular movements of the flange 631 and discs 630, 633 relative to each other. The flange 632 is rotatable relative to the component 604, together with the component 603. The friction generating device 613a can be said to constitute a part of the damping unit 613 and is designed to resist each and every angular movement of the components 603 and 604 relative to each other. This friction generating device is installed between the disc 630 and the component 603 and comprises an energy storing device in the form of a diaphragm spring 635 which reacts against the disc 630 and bears upon a ring 636. The ring 636, in turn, urges a washer 637 against the component 603. The force which is transmitted by the diaphragm spring 635 to the disc 630 is taken up by the radial bearing 616. The flange 632 is the input member of the damping unit 613 as well as the output member of the damping unit 614. The input member of the damping unit 614 includes two axially spaced-apart discs 638, 639 which are non-rotatably secured to the component 603. The disc 639 is affixed to the component 603 by rivets 640. The periphery of the disc 638 is provided with integral projections in the form of axially extending lugs 638a which extend into complementary recesses 641 of the disc 639. This ensures that the discs 638, 639 can move axially toward and away from each other but cannot perform any angular movements with respect to one another. The flange 632 has radially extending arms or teeth 642 which are clamped between the discs 638 and 639. For this purpose, the discs 638, 639 are biased toward each other by a diaphragm spring 643. The spring 643 reacts against the component 603 and bears upon the disc 638 in a direction to urge the disc 638 toward the disc 639. The discs 638, 639 have windows which register with each other and with tooth spaces between the arms 642 and serve to receive energy storing elements in the form of coil springs 644. In accordance with a feature of the invention which is shown in FIGS. 9 and 10, the component 604 is provided with axially extending passages 645 which are disposed between the bore 618 for the radial bearing 616 and the friction surface 604a of the component 604, as considered in the radial direction of the composite flywheel 602. The passages 645 serve to prevent the transfer of substantial quantities of heat from the friction surface 604a of the component 604 to the bearing 616. As can be seen in FIG. 10, the passages 645 can constitute slots which are elongated in the circumferential direction of the component 604 and together form an annulus whose diameter 650 is smaller than the minimum diameter of the friction surface 604a but greater than the diameter of the surface surrounding the bore 618 of the component 604. The passages 645 are preferably adjacent, and most preferably closely adjacent, the bearing 616. In accordance with a presently preferred embodiment of the invention, the cross-sectional areas of the passages 645 increase in a direction from a surface 646 radially inwardly of the friction surface 604a toward an additional surface 647 of the component 604 opposite the friction surface 604a. The surface 647 faces the damping units 613 and 614. The component 604 has internal surfaces which surround the passages 645 and each of which includes a first or inner portion 648 nearer to the common axis of the components 603, 604 and extending in at least substantial parallelism with such axis, and a second or outer portion 649 which is more distant from the common axis of the components 603, 604 and diverges radially outwardly away from the common axis toward the periphery of the component 604. At least a portion of each surface portion 649 has a substantially convex outline as can be readily seen in the lower portion of FIG. 9. The shallow leftmost portion of each passage 645 is provided in the second surface 647 of the component 604 and extends radially at least along a portion (x) of the width of the friction surface 604a as considered in the radial direction of the flywheel 602. The surfaces bounding the passages 645 resemble those of air circulating vanes or blades on an air impeller and cause streams of air to flow through the passages 645 in a direction from the friction surface 604a toward the additional surface 647 of the component 604. This entails a pronounced cooling of the entire flywheel 602 and greatly reduces the amount of heat which is transmitted from the friction surface 604a to the bearing 616. Thus, that portion of the component 604 which is formed with the passages 645 can be said to constitute a thermal barrier which impedes the transfer of heat from the surface 604a to the antifriction bearing 616. In addition, streams of air flowing through the passages 645 effect a substantial cooling of component parts of the damping means 613, 614, 613a because such streams flow along the discs 633 and 639 and a portion of each such stream can escape, for example, through the windows of the discs 630, 633 and flange 632. As mentioned before, such windows are provided for the energy storing springs 634. FIG. 10 shows that the rivets 629 form an annulus whose diameter equals or approximates the diameter 650 of the circle formed by the annulus of passages 645. FIG. 10 further shows that each fastener 629 alternates with pairs of slit-shaped passages 645 which have identical lengths. The length of each of the webs 652 through which the fasteners 629 extend exceeds the length of a passage 645. For example, the length of a web 652 (as measured in the circumferential direction of the component 604) can be between 0.5 and 2.5 times the length of a passage 645. In the embodiment which is shown in FIGS. 9 and 10, the component 604 is provided with two sets of webs, namely the aforementioned relatively long webs 652 which carry the rivets 629 and shorter webs 651 which alternate with the longer webs 652. Any heat which is generated at the friction surface 604a and is to reach the antifriction bearing 616 must be transmitted through the webs 651 and 652. Such webs can be said to constitute small heat barriers because they are being cooled by streams of air flowing through the passages 645. That (innermost) portion of the component 604 which defines the bore 618 and surrounds the radial bearing 616 is denoted by the character 653. The portion 653 is surrounded by the annulus of passages 645 and by the webs 651 and 652 of the component 604. The length of a web 652 can equal or approximate the combined length of two shorter webs 651 (as measured in the circumferential direction of the radially innermost portion 653 of the component 604). The length of a passage 645 can equal or exceed (at least slightly) the length of a shorter web 651. The combined length of the passages 645 (in the circumferential direction of the component 604) can be between 20 and 70% of the total length of the corresponding portion of the component 604. In the embodiment of FIGS. 9 and 10, the combined length of the passages 645 can be at least 50% of the circumferential length of the corresponding portion of the component 604. In other words, at least onehalf of the circle whose diameter is shown at 650 can extend through the passages 645. It is also within the purview of the invention to increase the length of the passages 645. For example, if the radial bearing 616 can stand reasonably pronounced thermal stresses, or if the transmission of pronounced thermal stresses is impeded in another way, the length of the illustrated passages 645 can be increased as shown in FIG. 10 at 654, i.e., the shorter webs 651 can be omitted so that the rivets 629 alternate with relatively long passages each of which can extend along an arc in excess of 45 degrees. For example, the component 604 can be provided with four relatively long passages 645 which alternate with four webs 652, and each web 652 is traversed by at least one fastener in the form of a rivet 629. Since the webs 651 and/or 652 constitute relatively narrow portions of the component 604 and alternate with passages 645, they act not unlike restrictors or throttles to the transmission of heat from the friction surface 604a toward the bearing 616. Thus, the corresponding portion of the component 604 is cooled by streams of air flowing through the passages 645, and the webs 652 constitute restrictors in that they oppose the transmission of heat to the radial bearing 616 so that the useful life of such bearing is much longer than in conventional apparatus. In view of the aforediscussed distribution of material of the component 604 in the region of the circle whose diameter is shown at 650, and in view of the distribution of passages 645 in the form of an annulus which is disposed between the friction surface 604a and the radially innermost portion 653 of the component 604 (i.e., radially outwardly of the bearing 616), heat which is generated in response to engagement of the friction clutch 607 can entail some rise in the temperature of the radially innermost portion 653 but not to a value which could entail damage to the bearing 616. The feature that the bearing 616 is not subjected to excessive thermal stresses is attributable, to a considerable extent, to the fact that the major part of the mass of the component 604 is located radially outwardly of the passages 645. The placing of rivets 629 into the webs 652 exhibits the advantage that the rivets dissipate substantial quantities of heat which would otherwise pass through the webs 652 and into the radially innermost portion 653 of the component 604. Moreover, the rivets 629 transmit heat to the discs 630, 633 which dissipate such heat into the surrounding atmosphere. In other words, the rivets 629 ensure that a substantial percentage of heat which would have passed through the webs 652 and into the portion 653 is transmitted to parts (630, 633) having large exposed surfaces to ensure rapid dissipation of transmitted heat to atmospheric air. The heat barrier 624 including the rings 625, 626 constitutes an optional feature of the apparatus of FIGS. 9-10. Thus, if the bearing 616 is furnished with conventional sealing rings, the rings 625, 626 can be omitted and the bearing 616 can be fully assembled on the component 603 before the component 603 is assembled with the component 604. In such apparatus, the outer race 617 of the bearing 616 is or can be a press-fit in the bore 618 of the component 604. The just described mounting of the bearing 616 in the bore 618 (without the rings 625, 626) reduces the initial cost and simplifies the assembly of the apparatus 601. The passages 645 are provided in addition to those passages which are desirable or necessary in the component 604 for other purposes, for example, to facilitate assembly of the apparatus 601 by providing paths for the tool which is to rotate the bolts 605 and/or other tools. It is also known to provide the components of a composite flywheel with openings for withdrawal of lubricant and for other purposes. The passages 645 are provided for the specific purpose of reducing the transfer of heat between the antifriction bearing which is interposed between the components of the flywheel and the friction surface of the component which comes into contact with the linings of the clutch plate 609. The passages 645 extend all the way between the surfaces 604a and 647 of the component 604 so as to ensure the aforedescribed desirable circulation of air streams and attendant cooling of the corresponding portion of the component 604 radially outwardly of the portion 653 which supports and surrounds the outer race 617 of the antifriction bearing 616. It has been found that the passages 645 contribute significantly to the useful life of the bearing 616 because the bearing is shielded from excessive thermal stresses which develop when the friction clutch 607 is actuated and which are likely to rapidly destroy the bearing in the absence of any remedial measures in addition to those which are already known in the art. The provision of passages 645 is particularly desirable in apparatus which employ antifriction bearings whose components are assembled with a minimum of play so that pronounced and rapid heating or cooling of such bearings could entail extensive thermally induced distortion and attendant jamming of the parts. In fact, such excessive thermally induced distortion can lead to seizing with immediate destruction of the bearing. The streams of air which flow through the passages 645 further ensure adequate cooling of lubricant for the rolling elements 616a of the bearing 616 regardless of whether such lubricant is oil or grease. Adequate cooling (or prevention of overheating) of the lubricant also prolongs the useful life of the bearing 616. The passages 645 can be configurated in a number of different ways without departing from the spirit of the invention. It has been found that elongated passages in the form of arcuate slots are particularly advantageous because they ensure the flow of large quantities of air and reduce the combined length of webs 652 or webs 651, 652. The aforedescribed configuration of surfaces 648, 649 which surround the passages 645 is desirable and advantageous because such surfaces act not unlike the surfaces of vanes or blades and ensure forced circulation of air in the region of the circle including the diameter 650. The placing of passages 645 close to the radially innermost portion 653 of the component 604 also contributes to a more reliable prevention of overheating of the bearing 616. The provision of relatively shallow recesses which are provided in the surface 647 and constitute the radially outermost portions of the passages 645 ensures that a large percentage of air which is heated during flow through the passages is caused to flow radially outwardly and away from the bearing 616. The surfaces surrounding the passages can be said to constitute a radial fan which draws air from the space radially inwardly of the friction surface 604a and causes streams of air to flow first axially and thereupon radially outwardly toward the periphery of the component 604. This effectively reduces the likelihood of flow of large quantities of heated air toward the bearing 616. The aforementioned configuration (convexity) of the surface portions 649 in the passages 645 also contributes to a desirable flow of heated air radially outwardly and away from the radially innermost portion 653. While it is possible to provide the passages 645 in non-uniform or irregular distribution, a uniform or regular distribution is preferred at this time because it ensures predictable cooling of each and every portion of the component 604 in the region of the webs 651 and 652. As mentioned before, the mass of the component 604 radially outwardly of the passages 645 is much larger than the mass of the radially innermost portion 653. Since the flow of heated air is radially outwardly, eventual heating of the major part of the component 604 radially outwardly of the passages 645 does not entail an overheating of the portion 653 and bearing 616. The streams of air which flow through the passages 645 bring about a desirable cooling of the elements of the damping means 613, 613a, 614. This prolongs the useful life of such damping means and hence the useful life of the entire apparatus. Moreover, the streams of air can adequately cool the first component 603 of the composite flywheel 602. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims. We claim: 1. Apparatus for transmitting torque between an output shaft of a combustion engine and a transmission, comprising a composite flywheel including a first flywheel fixedly connectable to the output shaft of the engine and a second flywheel having a friction surface engageable with a clutch plate of a friction clutch with attendant generation of heat, said first and second flywheels being rotatable relative to each other and the friction clutch being connectable with said second flywheel and being arranged to couple said second flywheel with and to detach said second flywheel from the transmission; antifriction bearing means between said first and second flywheels; damper means for opposing rotation of said first and second flywheels relative to each other; means for at least reducing the transfer of heat from said friction surface to said bearing means, including heat insulating means interposed between said friction surface and said bearing means for substantially thermally insulating said bearing means from said friction surface; and sealing means engaging said insulating means to seal said antifriction bearing means. 2. The apparatus of claim 1, wherein said insulating means is disposed between said second flywheel and said bearing means, said sealing means being disposed between said insulating means and said bearing means. 3. The apparatus of claim 1, wherein said bearing means includes a race which supports and is rotatable with said second flywheel, said second flywheel including a seat adjacent said race and said insulating means being disposed between said seat and said race. 4. The apparatus of claim 1, wherein said insulating means contains a plastic material. 5. The apparatus of claim 1, wherein one of said first and second flywheels has an axial protuberance and the other of said first and second flywheels has a centrally located recess for said protuberance, said bearing means being disposed in said recess adjacent said protuberance and said insulating means being located in said recess adjacent said bearing means. 6. The apparatus of claim 1 for transmitting torque between the output shaft of the engine and an input shaft of the transmission, wherein said friction clutch is arranged to couple said second flywheel with and to detach said second flywheel from the input shaft of the transmission and said second flywheel has a centrally located recess for said bearing means, said first flywheel having a centrally located protuberance extending into said recess and said bearing means having a race rotatable with said second flywheel, said insulating means being disposed in said recess adjacent said race. 7. The apparatus of claim 1, wherein one of said flywheels has a central protuberance and the other of said flywheels has a recess for said bearing means and said protuberance, said bearing means having an inner race surrounding said protuberance and an outer race, said insulating means being disposed between said outer race and said other flywheel. 8. The apparatus of claim 1, wherein said insulating means further includes means for sealing said bearing means. 9. The apparatus of claim 1, wherein said insulating means further includes integral sealing means for said bearing means. 10. The apparatus of claim 1, wherein said bearing means includes a first race and a second race, said insulating means including at least one ring having a substantially L-shaped cross-sectional outline, said ring including an axially extending first portion surrounding one of said races and a second portion extending radially toward the other of said races. 11. The apparatus of claim 10, wherein the second portion of said ring at least partially overlaps radially and abuts axially said other race. 12. The apparatus of claim 1, wherein said bearing means includes a plurality of races and one of said races has a first and a second end, said insulating means including first and second rings each having a substantially L-shaped cross-sectional outline, said rings surrounding said one race and being adjacent the respective ends thereof. 13. The apparatus of claim 1, wherein said bearing means includes an inner race and an outer race, said insulating means comprising two rings each having a substantially L-shaped cross-sectional outline, said rings being mounted on said outer race and each having a radially inwardly extending portion. 14. The apparatus of claim 1, wherein said bearing means includes a plurality of races and said insulating means comprises two rings each having a substantially radially extending portion overlapping at least one of said races, and further comprising means for biasing said radially extending portions toward said at least one race. 15. The apparatus of claim 14, wherein said biasing means comprises at least one diaphragm spring. 16. The apparatus of claim 1, wherein said bearing means includes a plurality of races and said sealing means includes two rings having radially extending portions with tips overlapping at least one of said races, and further comprising means for biasing said tips toward said at least one race including at least one diaphragm spring which reacts against said second flywheel. 17. The apparatus of claim 1, wherein one of said flywheels has a recess for said bearing means, said insulating means being a press fit in said recess. 18. The apparatus of claim 17, wherein said bearing means and said insulating means constitute a preassembled unit which is installed in said recess. 19. The apparatus of claim 1, wherein said bearing means includes a plurality of races and said insulating means includes at least one ring having a substantially L-shaped crosssectional outline, said ring including a portion surrounding and extending axially of one of said races, said sealing means including a seal which is interposed between said portion of said ring and said one race. 20. The apparatus of claim 19, wherein said seal includes an O-ring. 21. The apparatus of claim 19, wherein said races include an inner race and an outer race, said one race constituting said outer race and having a groove for said seal, said seal being surrounded by said portion of said ring. 22. The apparatus of claim 19, wherein said portion of said ring has an end face and said one race has a shoulder confronting said end face, said seal being clamped between said shoulder and said end face.

1988-12-13

en

1990-01-02

US-24922981-A

Radioreceptor assay for benzodiazepines in saliva ABSTRACT A radioreceptor assay for benzodiazepines in saliva which comprises measuring the diminution of attachment of a known quantity of radio labeled benzodiazepine to a receptor carrier in the presence of an unknown quantity of unlabeled benzodiazepine in a known amount of human saliva. Benzodiazepines are selected from the following oft-utilized drugs which are also representative types of benzodiazepine; namely, diazepam (Valium), chlordiazepoxide (Librium), nitrazepam (Benzalin), oxazepam (Serax), flurazepam (Dalmane), and clorazepate. Competitive receptors suitable for the present benzodiazepine radioreceptor assay are from fresh rat frontal cortex. Utilizable receptors are whole brain cortex, human cortex, and striatum. This is a continuation of application Ser. No. 014,552, filed Feb. 23, 1979, now abandoned. This invention relates to a radioreceptor assay for benzodiazepines in saliva which comprises measuring the diminution of attachment of a known quantity of radio labeled benzodiazepine to a receptor carrier in the presence of an unknown quantity of unlabeled benzodiazepine in a known amount of human saliva. Benzodiazepines are selected from the following formulae of oft-utilized drugs: ##STR1## The above structural formulae are illustrative of a larger group of active compounds, such as diazepam (Valium), chlordiazepoxide (Librium), nitrazepam (Benzalin), oxazepam (Serax), flurazepam (Dalmane), and clorazepate. Competitive receptors suitable for the present benzodiazepine radioreceptor assay are from fresh rat frontal cortex. Utilizable receptors are whole brain cortex, human cortex, and striatum. The basic utility of active members of the benzodiazepines is as a clinical anxiety reliever or hypnotic. The benzodiazepines are the most commonly used prescription drugs in this country. They are commonly used to treat anxiety and insomnia and are increasingly being used to treat alcohol withdrawal symptoms and epileptic seizures. Routine monitoring of benzodiazepine concentrations would be desirable for many reasons. Patient dose requirements vary widely due to the wide range of blood levels reported following the same dose. Because benzodiazepine side effects, such as lethality when mixed with alcohol, and the risk of physiological and psychological dependence are apparently does related, patients should be maintained on the lowest effective therapeutic dose. Although threshold levels must be attained for therapeutic efficacy, excessive levels may cause clinical worsening. PRIOR ART STATEMENT U.S. Pat. No. 4,083,948 Davis et al. (Hoffmann-LaRoche) is a radioimmunoassay for benzodiazepines using preferably 125 I-labeled 4'-hydroxy derivatives of these compounds as tracers. U.S. Pat. No. 4,119,709 Holub is a diagnostic test based on competitive binding where there is a difference for the radioactive labeled form of the substance between liquid and solid phases. M. A. Schwartz, "Pathways of Metabolism of the Benzodiazepines," The Benzodiazepines, ed. by S. Garattini et al., New York, Raven Press, 1973, pp. 75-97. C. Brasestrup et al., "Specific Benzodiazepine Receptors in Rat Brain Characterized by High Affinity [3 H] Diazepam Binding," Proc. Natl. Acad. Sci., 74(9):3805-3809, 1977. R. F. Squires, "Benzodiazepine Receptors in Rat Brain," Nature, 266:732-734, 1977. In the literature the principal method for measuring benzodiazepines, gas liquid chromatography, has not attained routine clinical use because of technical complexities. Also, development of a specific assay is required for each drug and its metabolites. In this invention there is described an assay for benzodiazepines in saliva based on competition for diazepam receptor binding. The assay is sensitive and simple enough for routine clinical use. Measurement of benzodiazepines in saliva offers advantages over plasma level determinations; saliva is easier to collect, particularly from anxious patients, and faster to assay. Also, saliva more directly reflects an intracellular environment and thus may correspond more closely to clinical efficacy than plasma level. The following description represents the best mode for carrying out the present invention as well as one or more specific examples or embodiments of the working thereof. In this assay, saliva is used without any extraction or precipitation. The saliva is first centrifuged (10,000 g for 20 mins) to separate it into mucous sediment and serous supernatant. The serous supernatant is diluted by a factor of two with 50 mM Tris buffer pH 7.7 at 25° C. [tris(hydroxymethyl)aminomethane] and added directly to the assay. The absence of interference by saliva itself is apparent from experiments in which 100λ of diluted saliva in a total assay volume of 0.5 ml reduced 3 H-diazepam binding by only 1.60±0.08%. Increasing volumes of saliva reduced binding linearly with about 45% inhibition occurring with 100λ of saliva. Saliva reduces specific and non-specific binding to the same extent, suggesting that saliva proteins bind 3 H-diazepam, making less available for interaction with brain membranes. The inhibition of binding by the saliva of several laboratory personnel was uniform, as was inhibition of binding by the same subjects' saliva collected on different days. Variability of inhibition of specific binding for repeated determinations of the same sample was less than 5%. In summary, the simplicity of the benzodiazepine receptor assay for saliva, as well as the ease with which saliva samples (0.2 ml each) can be collected and stored, make this assay suitable for routine clinical use in large patient populations. Saliva can be collected at home and refrigerated for later assay. The assay is selective; chlorpromazine (10-5 M), haloperidol (10-5 M), pimozide (10-5 M), fluphenazine (10-5 M), desmethylimipramine (10-5 M), pargyline (10-5 M), dl-propranolol (10-5 M), and levallorphan (10-5 M) incubated with saliva failed to inhibit 3 H-diazepam binding more than saliva itself, suggesting that this assay can be used in patients who are being treated with a variety of other drugs besides benzodiazepines. For patients receiving more than one benzodiazepine, the absolute concentration of each cannot be determined separately. In such cases, inhibition of 3 H-diazepam binding would be converted to a diazepam equivalent which would produce the same degree of inhibition. The radioreceptor assay for benzodiazepine in saliva is simpler to perform than would be a radioreceptor assay for benzodiazepines in plasma (red blood cells). There is a high degree of inhibition of 3 H-diazepam specific and non-specific binding by both plasma and red blood cell lysates. This necessitates extra steps for further purification of plasma by deproteination and centrifugation. In the radioreceptor assay for benzodiazepines in saliva, this is not necessary. Dilute serous saliva is added directly to the assay without further extraction or purification. Large amounts of cortex can be obtained from rats and stored frozen. 3 H-diazepam is commerically available. It is believed that 100 samples can be assayed in a day. EXAMPLE 1 Competition by Inhibition Caused by Drug-Free Saliva Benzodiazepines in saliva reduce the specific binding of 3 H-diazepam more than the small degree of inhibition caused by drug-free saliva and the amount of inhibition of specific binding is proportional to the amount of benzodiazepine in saliva. The amount of benzodiazepine in a saliva sample can easily be determined using a standard curve of inhibition of 3 H-ligand binding by known amounts of the drug. This method requires that benzodiazepines present in saliva will not inhibit non-specific (blank) binding of 3 H-ligand. In 14 saliva samples from patients on benzodiazepines, blank 3 H-diazepam binding was 231±5 CPM, while non-specific binding in the presence of 12 control saliva samples was 205±7 CPM. Thus, specific binding in the presence of patient saliva can be determined by subtracting non-specific binding values obtained with control saliva from total binding with patient saliva. The percentage inhibition of specific 3 H-diazepam binding (in the presence of control saliva) by the patient saliva (containing drug) was then calculated and compared to a standard displacement curve for determining actual benzodiazepine content. Similar reductions in specific and non-specific binding of 3 H-diazepam by saliva indicated that saliva components bind benzodiazepines making less available for membrane binding. In this assay, benzodiazepine bound to saliva components dissociates during the incubation so that total benzodiazepine levels were measured. To confirm this, 100 nM diazepam was pre-incubated for 10 mins at 37° C. with control saliva to allow binding to saliva proteins to occur. The saliva with diazepam was then added to a standard binding assay. The time course and extent of reduction of binding was the same for diazepam pre-incubated with saliva and diazepam dissolved in buffer. The maximum percentage lowering of binding was equivalent to that produced by 100 nM diazepam added directly to the assay with no saliva present. For the benzodiazepine radioreceptor assay, fresh rat frontal cortex was homogenized (Brinkman polytron, setting 6 for 30 secs) in 50 volumes (w/v) 50 mM Tris buffer, pH 7.4 at 25° C. The homogenate was centrifuged twice at 50,000 g for 10 mins, with re-homogenization of the intermediate pellet in fresh buffer. The final pellet (which may be stored frozen) was resuspended in 15 volumes of freshly prepared 50 mM Tris buffer, pH 7.4 at 25° C. 3 H-diazepam (80 Ci mmol-1, New England Nuclear) was diluted to 5 nM in fresh buffer. Polypropylene 12×75 mm incubation tubes received, in order, 100λ diluted saliva (on benzodiazepine therapy or drug free), 50λ 3 H-ligand, 50λ drug for standard curve or nitrazepam for blanks (final concentration 1 micromolar) or the drug solvent buffer, and tissue suspension to 0.5 ml total volume. Final concentration of 3 H-diazepam was 0.50 nM. The tubes were incubated at 0° C. for 45 mins and rapidly filtered under vacuum through Whatman GF/B filters with two 5 ml rinses of ice cold 50 mM Tris buffer pH 7.4 at 25° C. 3 H-diazepam trapped on the filters was counted by liquid scintillation spectrometry after remaining overnight in scintillation vials containing Aquasol (New England Nuclear). A standard displacement curve for the drug under study was determined in the presence of equal volumes of control saliva with final concentrations of drug about one-third, three times, and the same as its IC50 value for inhibiting 3 H-diazepam binding under the conditions described. A log-probit plot was used to convert the displacement curve to a straight line, allowing percentage inhibition of 3 H-diazepam to be converted to molar drug concentration (FIG. 1). To examine recovery, four different benzodiazepines were pre-incubated with saliva for 10 mins at 37° C. to provide time for binding to saliva proteins and subsequently assayed for benzodiazepine levels. Diazepam (100 nM), chlordiazepoxide (1000 nM), nitrazepam (100 nM), and oxazepam (100 nM) were all fully recovered in the benzodiazepine radioreceptor assay with respective values of 97 nM (n=4), 1000 nM (n=4), 100 nM (n=4), and 100 nM (n=4). EXAMPLE 2 This example compares the present radioreceptor assay and its saliva levels with another procedure which is gas liquid chromatography with electron capture. Saliva benzodiazepine levels were measured in patients treated with oxazepam; saliva oxazepam levels were determined on the same samples by gas liquid chromatography with electron capture and by saliva radioreceptor assay. Table 1 indicates a good agreement between the different methods. Using 100λ of two-fold diluted saliva, the lower limit of sensitivity (7% inhibition of specific binding) is 0.14 ng/ml, 1.50 ng/ml, 0.28 ng/ml, and 2.87 ng/ml for diazepam, chlordiazepoxide, nitrazepam and oxazepam, respectively. TABLE 1 ______________________________________ Results of Split Sample Determinations Using the Radio- receptor Assay and Gas-Liquid Chromatography With Electron Capture Gas-Liquid Radioreceptor Chromatography with Sample Assay Electron Capture ______________________________________ 1 17.2 16.8 2 17.2 17.9 3 20.1 19.6 4 16.7 20.3 5 15.5 16.7 6 18.9 18.6 7 28.7 28.7 8 28.7 29.9 ______________________________________ (Intraclass correlation = 0.95; p<.0001) I claim: 1. In a radioreceptor assay for benzodiazepine in saliva which comprises measuring the diminution of attachment of a known quantity of radiolabeled benzodiazepine to a receptor carrier in the presence of an unknown quantity of unlabeled benzodiazepine in a known amount of human saliva, the improvement wherein(1) the saliva is centrifuged to separate mucous sediment and serous supernatant; (2) the serous supernatant is diluted and incubated with radiolabeled benzodiazepine and receptor carrier at 0° C. for about 45 minutes, wherein the receptor carrier is fresh brain cortex or striatum homogenized and formed into a pellet. 2. The method according to claim 1 wherein the unlabeled benzodiazepine is diazepam. 3. The method according to claim 1 wherein the unlabeled benzodiazepine is chlordiazepoxide. 4. The method according to claim 1 wherein the unlabeled benzodiazepine is nitrazepam. 5. The method according to claim 1 wherein the unlabeled benzodiazepine is oxazepam. 6. The method according to claim 1 wherein the radio labeling is by 3 H.

1981-03-30

en

1984-02-14

US-49974174-A

Process for the conversion of hydrocarbonaceous black oil ABSTRACT A process for the conversion of a hydrocarbonaceous black oil, wherein a heated portion of the charge stock is recycled to the inlet of the charge heater, is disclosed. United States Patent m1 Gatsis l l PROCESS FOR THE CONVERSION OF HYDROCARBONACEOUS BLACK OIL [75] Inventor: John G. Gatsis, Des Pl'ttincs. Ill. [73] Assignce: Universal Oil Products Company, Des Pluines, Ill. [32} Filed: Aug. 22 1974 [ll Appl. No.: 499,741 l.H-lI.754 NW3] Herthel INK/4R X I Nov. 11, 1975 li'llhhl NW4) Muth Imus R l'l lblh' 731957 Burr et (ll... IIISSRGI 1.953.514 4/1960 Wilkins............. INS/Q5 lllifilfi llwllhi Watkins... BUSH-l3 .mZlhHZ-l ll. W65 MeKinne et all. H JUN/I43 1124A) llrl lffi Schlinger et ul. ZUh'lHI? 122N701 ll/IIhh D(l\\d et ul... INN/4H R $496,005 I/l F/tl l.u\\i H JUN/57 [57] ABSTRACT A pmeess for the conversion of u h Lll'OCLlfbUflllCCttllS hlttek oil. wherein a heated portion of the charge stuck is rec \e|ed to the inlet of the charge heater. is disclused. 4 Claims. No Drawings PROCESS FOR THE CONVERSION OF I-IYDROCARBONACEOUS BLACK OIL DISCLOSURE The invention described herein is adaptable to a process for the conversion of petroleum crude oil into boiling hydrocarbon products. More specifically. the present invention is directed toward a process for converting atmospheric tower bottoms products, vacuum tower bottoms products, crude oil residuum, topped crude oils, crude oils extracted from tar sands, etc.. which are sometimes referred to as black oils," and which contain a significant quantity of asphaltic material. Petroleum crude oils, particularly the heavy oils extracted from tar sands, topped or reduced crudes, and vaccum residuum, etc., contain high molecular weight sulfurous compounds in exceedingly large quantities. In addition, such crude, or black oils contain excessive quantities of nitrogenous compounds, high molecular weight organo-metallic complexes principally comprising nickel and vanadium, and asphaltic material. Currently, an abundant supply of such hydrocarbonaceous material exists, most of which has a gravity less than 20.0 AP] at 60F, and a significant proportion of which has a gravity less than 10.0. This material is generally further characterized by a boiling range indicating that percent or more, by volume boils above a temperature of about 1,050F. The conversion of at least a portion of the material into distillable hydrocarbons--i.e., those boiling below about l,050F.has hitherto been considered nonfeasible from an economic standpoint. Yet, the abundant supply thereof virtually demands such conversion, especially for the purpose of satisfying the ever-increasing need for greater volumes of the lower boiling distillables. The present invention is particularly adaptable to the catalytic conversion of black oils into distillable hydrocarbons. Specific examples of the black oils to which the present scheme in uniquely applicable, include a vacuum tower bottoms product having a gravity of 7.1 API at 60F. containing 4.05 percent by weight of sulfur and 23.7 percent by weight of asphaltics; a topped" Middle East Kuwait crude oil, having a gravity of 110 AP] at 60F., containing 10.1 percent by weight of asphaltenes and 5.20 percent by weight of sulfur; and a vacuum residuum having a gravity of 8.8 APl at 60F, containing 3.0 percent by weight of sulfur and 3,400 ppm. of nitrogen and having a 20.0 percent volumetric distillation point of 1,055F. The principal difficulties, attendant the conversion of black oils, stem from the presence of the asphaltic material. This asphaltic material consists primarily of high molecular weight, non-distillable coke precursors, insoluble in light hydrocarbons such as pentane or heptane, and which are often found to be complexed with nitrogen, metals and especially sulfur. Generally, the asphaltic material is found to be colloidally dispersed within the crude oil, and, when subjected to elevated temperatures, has the tendency to flocculate and polymerize whereby the conversion thereof to more valuable oilsoluble products becomes extremely difficult. Not only does the flocculation and polymerization of the asphaltic material decrease the yield of valuable hydrocarbon products but when these coke precursors form coke during heating and prior to entering the catalytic reaction zone, the internal surfaces of the heaters 2 which contact the oil become coated with coke. Such coking or fouling of the heaters heat transfer surface causes less favorable heat transfer rates and in order to compensate for this lower heat transfer rate, the heater temperatures must be increased which only further aggravates the coking problem. I have discovered that this problem can be alleviated by providing a recycle of previously heated black oil to the inlet of the heater to ensure adequate turbulence and ample mixing of the black oil being heated. This recycle will lessen the temperature gradient across the heat transfer area of the heater, and provide a more uniform oil temperature in the entire cross-section of the flowing black oil. Furthermore, this recycle will promote better heat transfer, thereby lowering the temperature of the heat transfer surface which, in turn, lessens the propensity of the black oil along with the asphaltenes contained therein to form coke and heavy polymers. A principal object of the present invention is to retard and inhibit the formation of undesirable coke and polymers on the heat transfer surfaces of the primary heater in a process for the conversion of hydrocarbonaceous black oil. Another object is to promote better initial heat transfer rates in such a heater which will permit a lower temperature for the heat transfer surfaces which. in turn, will minimize coke-producing high temperatures. Yet another object is to extend the length of time between maintenance of the heat exchange surfaces for the removal of accumulated coke and polymers. In one embodiment, therefore, the present invention relates to a process for the conversion of a hydrocarbonaceous black oil, which process comprises the steps of: (a) admixing said black oil with hydrogen and heating the resulting mixture in a heater to a temperature above about 600F.; (b) recycling at least a portion of the heated mixture to the inlet of said heater; (c) contacting at least a portion of the heated mixture with a catalytic composite in a conversion zone maintained at hydrocarbon conversion conditions; and, (d) recovering a converted hydrocarbon product. A black oil is intended to connote a hydrocarbonaceous mixture of which at least about 10 percent boils above a temperature of about l,050F., and which has a gravity, API at 60F., of about 20 or less. As will be readily noted by those skilled in the art of petroleum refining techniques, the conversion conditions hereinafter enumerated are well known and commercially employed. The conversion conditions include temperatures above about 600F., with an upper limit of about 800F., measured at the inlet to the catalytic reaction zone. Since the bulk of the reactions are exothermic, the reaction zone effluent will be at a higher temperature. In order to preserve catalyst stability, it is preferred to control the inlet temperature such that the effluent temperature does not exceed about 900F. Hydrogen is admixed with the black oil charge stock by compressive means in an amount generally less than about 20,000 SCFB, at the selected pressure and preferably in an amount of from about 1,000 to about 10,000 SCFB. The operating pressure will be greater than 500 psig. and generally in the range of about 1,500 psig. to about 5,000 psig. [t is not essential to my invention to employ a particular type of reaction zone. Upflow, downflow or radial flow reaction zones may suitably be employed within the reaction zone in a fixed bed, moving bed, ebullating bed or a slurry system. Likewise. the type, form or composition of the catalyst is not essential to my invention and any suitable black oil hydrocarbon conversion catalyst may be selected. The catalyst disposed within a fixed bed or moving bed reaction zone can be characterized as comprising a metallic component having hydrogenation activity. which component is composited with a refractory inorganic oxide carrier material of either synthetic or natural origin. The precise composition and method of manufacturing the carrier material is not considered essential to the present process, although a siliceous carrier, such as 88 percent alumina and 12 percent silica, or 63 percent alumina and 37 percent silica, or an all alumina carrier. are generally preferred. Suitable metallic components having hydrogenation activity are those selected from the group consisting of the metals of Group VI'B and VIII of the Periodic Table, as indicated in the Periodic Chart of the Elements, Fisher Scientific Company (1953). Thus the catalytic composite may comprise one or more metallic components from the group of molybdenum, tungsten, chromium, iron, cobalt, nickel, platinum, palladium, iridium, osmium, rhodium, ruthenium and mixtures thereof. The concentration of the catalytically active metallic component, or components. is primarily dependent upon the particular metal as well as the characteristics of the charge stock. For example, the metallic components of Group Vl-B are preferably present in an amount within the range of about l.0 percent to about 20.0 percent by weight, the iron-group metals in an amount within the range of about 0.2 percent to about 10.0 percent by weight, whereas the platinum-group metals are preferably present in an amount within the range of about 0.l percent to about 5.0 percent by weight, all of which are calculated as if the components existed within the finished catalytic composite as the elemental metal. The refractory inorganic oxide carrier material may comprise alumina, silica, zirconia, magnesia, titania, boria, strontia, hafnia, and mixtures of the two or more including silica-alumina, alumina-silica-boron phosphate, silica-zirconia, silica-magnesia, silica-titania, alumina zirconia, alumina-magnesia, alumina-titania, magnesia-zirconia, titania-zirconia, magnesia-titania, silica-alumina-zirconia, silica-alumina-magnesia, silicaalumina-titania, silica-magnesia-zirconia, silicaalumina-boria, etc. It is preferred to utilize a carrier material containing at least a portion of silica, and preferably a composite of alumina and silica with alumina being in the greater proportion. The catalysts utilized in a slurry system preferably contain at least one metal selected from the metals of Group VLB, V-B and VIII. Slurry system catalysts usually are colloidally dispersed in the hydrocarbonaceous charge stock and may be supported or unsupported. The following examples are given to illustrate the process of the present invention and the effectiveness thereof in inhibiting and retarding the formation of undesirable coke and polymers of the heat transfer surfaces of the primary heater in a process for the conversion of hydrocarbonaceous black oil. In presenting these examples, it is not intended that the invention be limited to the specific illustrations, nor is it intended that the process be limited to particular operating conditions, catalytic composite, processing techniques, charge stocks, etc. It is understood, therefore, that the present invention is merely illustrated by the specifics hereinafter set forth. EXAMPLE I A topped Middle-East Kuwait crude containing 5.2 percent by weight sulfur and to percent by weight oilinsoluble asphaltenic material and having a gravity of l l A?! at 60 "F. is selected for desulfurization in a catalytic reaction zone containing a desulfurization catalyst which contains 2 percent by weight nickel and I6 percent by weight molybdenum composited with a carrier material of 88 percent alumina and 12 percent silica. The desulfurization catalyst is loaded into fixed beds in a downflow catalytic reaction zone. The topped crude is admixed with sufficient hydrogen to achieve a hydrogen circulation rate of 6,000 SCFB. The admixture of topped crude and hydrogen is passed over the heat exchange surfaces of a primary heater and then into the catalytic reaction zone. A desulfurized hydrocarbonaceous black oil is recovered from the reaction zone effluent. A target 1 percent residual sulfur (the equivalent of percent desulfurization) in the hydrocarbon product is maintained by periodically adjusting the outlet temperature of the primary heater. With a liquid hourly space velocity of 0.9 hr. the initial catalyst inlet temperature required to reach the l percent target is 725F. The hereinabove processing scheme is continuously operated for 90 days and then is shut down. Inspection of the heat exchange surfaces shows that the carbon and polymer buildup on these surfaces amounts to 40 grams per square meter. EXAMPLE ll The processing scheme in Example I is modified to permit a slipstream of heated black oil to be taken from the effluent of the primary heater and recycled to the inlet of said primary heater. The heat exchange surfaces are thoroughly cleaned to remove the accumulated carbon and polymers. A fresh batch of catalyst which is identical to that used in Example I is loaded into the catalytic reaction zone and fresh topped crude is desulfurized at the same operating conditions utilized in Example 1 except that 10 percent of the liquid effluent from the primary heater is recycled to the inlet of the primary heater. The processing scheme is also continuously operated for 90 days and is then shut down. Inspection of the heat exchange surfaces shows that the carbon and polymer buildup on these surfaces amounts to 30 grams per square meter which is considerably less than that produced in Example I. The foregoing specification and illustrative examples clearly indicate the means by which the present invention is effected, and the benefits afforded through the utilization thereof. 1 claim as my invention: 1. A process for the conversion of a hydrocarbonaceous black oil, which process comprises the steps of: a. admixing said black oil with hydrogen and heating the resulting mixture in a heater to a temperature above about 600F.; b. recycling at least a portion of the heated mixture to the inlet of said heater; c. contacting at least a portion of the heated mixture with a catalytic composite in a conversion zone maintained at hydrocarbon conversion conditions; and, d. recovering a converted hydrocarbon product. 2. The process of claim 1 further characterized in that said heater is a direct fired heater. 3,919,074 6 3. The process of claim I further characterized in a pressure of from about 500 psig. to about 5,000 psig.. that said black oil is derived from tar sand. shale or any a temperature of from about 600F. to about 900F.. a other inorganic oil-bearing substance. hydrogen gas circulation rate from about 1.000 SCFB 4. The process of claim I further characterized in 5 to about 20,000 SCFB. that said hydrocarbon conversion conditions comprise 1. A PROCESS FOR THE CONVERSION OF A HYDROCARBONACEOUS BLACK OIL, WHICH PROCESS COMPRISES THE STEPS ODF: A. ADMIXING SAID BLACK OIL WITH HYDROGEN AND HEATING THE RESULTING MIXTURE IN A HEATER TO A TEMPERATURE ABOVE ABOUT 600*F., B. RECYCLING AT LEAST A PORTION OF THE HEATED MIXTURE TO THE INLET OF SAID HEATER, C. CONTACTING AT LEAST A PORTION OF THE HEATED MIXTURE WITH A CATALYTIC COMPOSITE IN A CONVERSION ZONE MAINTAINED AT HYDROCARBON CONVERSION CONDTIONS, AND, D. RECOVERING A CONVERTED HYDROCARBON PRODUCT. 2. The process of claim 1 further characterized in that said heater is a direct fired heater. 3. The process of claim 1 further characterized in that said black oil is derived from tar sand, shale or any other inorganic oil-bearing substance. 4. The process of claim 1 further characterized in that said hydrocarbon conversion conditions comprise a pressure of from about 500 psig. to about 5,000 psig., a temperature of from about 600*F. to about 900*F., a hydrogen gas circulation rate from about 1,000 SCFB to about 20,000 SCFB.

1974-08-22

en

1975-11-11

US-72571985-A

Tool for removal of an engine cylinder liner ABSTRACT To service an engine, it is frequently determined that a cylinder liner and piston must be replaced. Removal is difficult and time consuming if the piston is first removed through the liner and the liner is then grasped from below and pulled from the block. A method includes inserting a tool into a bore of the liner and expanding the tool into a frictional fit against the liner. A force is applied on the tool to forcibly move the liner. The piston and associated rings and rod are held in place in the liner by a partial vacuum for removal with the liner as a complete unit. This is a division of Ser. No. 549,130 filed Nov. 7, 1983, now U.S. Pat. No. 4,530,141 issued July 23, 1985, which is a continuation-in-part of Ser. No. 490,942 filed May 2, 1983, now abandoned. DESCRIPTION 1. Technical Field The invention relates to removal of a cylinder liner, piston, ring and rod from an engine, and more particularly the invention relates to a method of removing such engine components as a unit. 2. Background Art Internal combustion engines commonly utilize cylinder liners to define the bores in which the pistons reciprocate. During operation of the engine, the combustion process results in a carbon build-up or wear step near the top of the point of piston travel in the liner. This and other types of wear usually necessitate replacement of the cylinder liners and pistons after a period of time. Removal of the liners, however, is complicated by an interference fit between the liners and the block. The interference fit is established, for example, by O-rings about the liners and it generally increases because of the high temperatures and other conditions of engine use. Heretofore, a liner without air inlet ports therethrough has commonly been removed by inserting a tool down into the bore which may then be adjusted to grasp the end face of the liner. The liner is then pulled from the block by applying sufficient force on the tool to overcome any interference fit. A disadvantage of this practice is that the piston must first be removed through the top of the associated cylinder liner so that the tool may be inserted in the liner. Performing these individual steps is inconvenient and time consuming, particularly where the carbon build-up or wear step is pronounced and must first be removed by grinding in order to the slide the piston out of the bore. In two cycle engines where the liners have an inlet port, it is known to insert into the liner a tool which has a rod with two ends. Each of the ends are positioned in opposite ports in the liner, and the engine rotated to urge the associated piston against the rod for dislocating the liner. This practice is described in U.S. Pat. No. 3,805,359 which issued to Webb on Apr. 23, 1974. U.S. Pat. No. 3,945,104 which issued to Brookover on Mar. 23, 1976, shows another such tool in which an impact device is slidable on the tool to strike an anvil and break the liner loose. It will be noted, however, that this type of removal practice still requires separate steps to remove the piston and rod. The present invention is directed to overcoming one or more of the above problems. DISCLOSURE OF THE INVENTION In one aspect of the present invention, a method is employed for removing a cylinder liner, piston, ring and rod as a unit from an engine block. The method includes inserting a tool in the bore of the liner, expanding the tool against the liner and establishing frictional contact between the tool and liner. The method further includes applying a force on the tool and moving the tool with the liner relative to the engine block, establishing at least a partial vacuum in the liner above the piston, and then removing as a unit the liner with the piston, ring and rod. In another aspect of the present invention, a method includes inserting a tool having a driver and mandrel in the bore of the cylinder liner and moving the piston against and urging the driver into an aperture of the mandrel. The method further includes applying a force on the mandrel in the direction of piston travel and diametrically expanding the mandrel into frictional engagement with the liner in response to the driver being urged into the mandrel, and moving the tool with the liner relative to the engine block. At least a partial vacuum is established in the liner above the piston, and the liner together with the associated piston, ring and rod are removed as a unit. In still another aspect of the invention, a tool for removing a cylinder liner from an engine block has a mandrel and a driver. The driver is insertable into an aperture of the mandrel. Means is provided for applying a force on the driver for moving the driver to a preselected first position in an aperture of the mandrel. The cylinder liner, piston and other associated components are removed as a unit to simplify engine repair work. Removal as a unit obviates separate operations which involve first removing the piston through the liner and then insertion of a tool to grab the underside of the liner in order to pull the liner out of the block. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of a portion of an engine and a tool in place on the engine for performing an embodiment of the method of the present invention; FIG. 2 is similar to FIG. 1, but illustrates an intermediate step during the disclosed method; FIG. 3 illustrates in detail the tool shown in FIG. 1 which may be used to perform a method of the present invention; FIG. 4 is a view in cross-section of one portion of the tool of FIG. 3 taken along line IV--IV of FIG. 3; FIG. 5 is a diagrammatic view of an embodiment of the present invention showing a tool which may be used to perform a method of the present invention; and FIG. 6 is a diagrammatic end view in partial section of the tool of FIG. 5. BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIG. 1, a portion of an internal combustion engine 10 is disclosed to illustrate a "cylinder" of the engine. Disregarding for the moment the tool 12, the engine has a block 14 in an opening of which is located a cylinder liner 16 forming a cylinder bore 18 of the engine. The outer surface 19 of the cylinder liner is sized for a "pilot" fit with the block opening and has O-rings 20 positioned in grooves on a lower portion of its outer surface. When the liner is fitted to the block, the O-rings establish an interference fit on the lower step 24 of the block. A piston 26 having a top surface 27 and with rings 28 retained in grooves on its outer surface is positioned in the cylinder bore 18. The piston pivotally connects to a rod 32 by conventional means which includes a wrist pin 34. The rod is connected to a crankshaft 37 by use of a rod cap 38. The engine head (not shown) fits over the top surface 35 of the block 14. The construction and operation of such engines are understood in the art and will not be further explained. Referring now particularly to FIGS. 3 and 4, an embodiment of a tool 12 which may be employed to remove a cylinder liner, piston with one or more rings, and rod in their assembled or operational relationship is shown. The tool is diametrically adjustable such that it can be inserted into the cylinder bore 18 even where a carbon build-up or wear step is present on the liner 16. The tool has two segments 40 which may be described as single-tapered collets with slots 42 such as are often used to make chucks for holding workpieces during machining operations. The segments are constructed of metal with the slots filled or sealed with an elastomeric or plastic material identified by reference numeral 44. Two tapered arbors 46 are receivable in tapered openings 47 in the segments 40. The arbors are of metal construction and each may be slotted to receive a key for engagement with a slot in its respective segment. A bolt 48 is positionable through openings in the segments and arbors. One of the arbors is counterbored to receive the bolt head (see FIGS. 1 and 2). The bolt is also positionable through openings in a spacer 50 and oversized washer 52 and is at one end threadably engageable with a nut 54. It will be seen that when the tool is assembled and the nut is turned relative to the bolt, the tapered arbors will be urged further into their respective tapered openings causing the segments to expand diametrically. The tool 12 of FIGS. 3 and 4 is shown in FIGS. 1 and 2 to, as later described, illustrate removal from the engine 10 of a unit 58 defined to include the cylinder liner 16, piston 26, rings 28 and rod 32 assembled together in their operational relationship. Another embodiment of tool 12 is shown in FIGS. 5 and 6. That tool has a mandrel 60 with a circumferential wall 62. The circumferential wall 62 has an outer surface 64 defining a diameter of the mandrel and an inner surface 66, at least partly tapered, defining an aperture 68. The aperture is shown opening on first and second ends 69,70 respectively, of the mandrel. The mandrel also has a plurality of slots 72 dividing the circumferential wall into segments 74 such that diametrical expansion of the mandrel tends to occur in response to forces exerted on the inner surface. The slots preferably are symmetrically located and extend substantially the length of the mandrel so expansion will be essentially uniform. The mandrel also desirably has its outer surface and second end covered with a flexible, preferably elastomeric, cover 76. A cap 78 having an opening 80 therethrough is also positionable on the second end of the mandrel. The tool 12 further has a driver 82 which has a base 84 and a body portion 86 with tapered walls 88. The tapered walls extend from the base and define a frusto-conical shape. The body portion is insertable into the aperture 68 from the first end 69 of the mandrel 60. The driver also has an opening 90 therethrough which is at least partly threaded. The base of the driver extends across the first end of the mandrel when the body portion is positioned in the mandrel. Means 94 is provided for applying a force on the driver 82 for moving the driver, once inserted into the mandrel 60, to a preselected position in the aperture 68 at which the body portion 86 urges against the inner surface 66 tending to enlarge the diameter of the mandrel. The means includes a threaded rod 96 with a nut 98 and a threaded portion 100 which engages with the threaded portion of opening 90 of the driver so that the driver may be "pulled" into position in the mandrel by progressively tightening the nut against the cap. It will be seen that the body portion is movable to succeeding positions in the aperture because the tapered wall of the body portion will slide along the tapered inner surface 66 defining the aperture when sufficient force is applied to the driver. At each succeeding position the tapered walls of the body portion will increasingly forcibly urge against the inner surface tending to define a larger diameter of the mandrel. A tool 12 such as illustrated is inserted into the cylinder bore 18 and expanded against the inner walls of the cylinder liner 16 (FIG. 1). Expansion establishes a frictional fit or contact between the cylinder liner and the outer surface of the tool. For example, with the tool of FIGS. 3 and 4, the bolt 48 is adjusted to establish frictional forces between the tool and liner greater than those of the fit of the liner in the bore 18. The tool of FIG. 5 also facilitates this practice by adjustment of the nut 98. Uniform diametrical expansion and metal-rubber construction, characteristics of the illustrated tools, substantially eliminate damage to the liner. A force is subsequently applied on the tool in a longitudinal or axial direction relative to the liner. Because of the frictional fit of the tool with the liner, sufficient force on the tool "breaks" the interference fit and the liner will move with the tool from its position in the engine block 14 (FIG. 2). The liner is thus removable from the block. Sufficient force for removal may be applied to the tool 12 by moving the piston 26 in the bore 18 and engaging the piston with and urging it against the bottom of the tool. The piston is moved by rotating the crankshaft 37 with, for example, an engine turning tool which engages the flywheel in much the same fashion as the engine starter pinion. The force on the tool 12 may also be applied on the top of either of the described tools such as by positioning a bar across and spaced from the top of the tool. The bar, for example, may be supported by spacers resting on the top surface 35 of the block 14. For the tool of FIG. 3, a rod passes through an opening in the bar with one end attached to the tool and the other end threadably engaged by a nut. The nut may be adjusted working against the bar to raise the rod thereby applying a lifting force to the tool. For the tool of FIG. 5, the threaded rod 96 passes through the bar. An additional nut is tightened against the cap 78 to hold the threaded portion in place in the driver while nut 98 is adjusted to provide the lifting force. Other devices may also be used. The tool 12 of FIGS. 5 and 6 also facilitates removing the unit 58 by using movement of the piston 26 to provide both the force for removal and the force for expansion of the tool. At the outset, the mandrel 60 need only be held against movement in the cylinder liner 16 with sufficient force to resist the tendency of the mandrel to slide in the liner as the piston initially moves against the driver. This force may be established, for example, by use of the threaded rod 96 and nut 98 to diametrically expand the mandrel to a preselected frictional engagement with the liner. Thereafter, further piston movement progressively urges the driver into the mandrel to succeeding positions, and the mandrel is expanded diametrically thereby increasing the frictional force holding the tool in the liner. Simultaneously, a force is also increasingly exerted on the tool in the direction of piston travel until the liner breaks loose in the bore 18. For the above purpose, it is expected that the relative tapering configurations and other aspects of the mandrel and driver can be established by one skilled in the art. Normally, the base 84 against which the piston urges should be as large as possible to spread out the forces applied. For the engine 10 shown, movement of the tool 12 and liner 16 by the piston 26 or other device applying the force need be only that sufficient to break the interference fit of the O-rings 20. In other engine configurations more tool-liner movement may be desirable or necessary depending upon the nature of the interference fit of the liner and engine block 14. At least a partial vacuum is to be established in the liner 16 above the top surface 27 of the piston 26 to maintain the unit 58 intact for and during removal. The tool 12 may be used throughout removal as an air-tight covering with the vacuum being established in the liner between the tool and piston. As an example, expanding the tools shown also establishes an air-tight fit or contact between the tool and liner to facilitate forming the vacuum. Alternately, the tool may be removed to be used on other cylinders or engines with a cap being put in place on the top of the liner to act as the air-tight covering. The cap, for example, may be a plastic plug which simply fits snugly into the bore 18 and "seals" against the liner's inner surface. The vacuum is established between the plug and the piston. Experience has shown that conditions for generating sufficient vacuum may be established by having the piston 26 in contact or closely adjacent the tool 12 or cap prior to lifting the liner from the block 14 (See FIG. 2). The vacuum is established from the tendency of the piston to move downwardly when the liner is lifted with the piston, rings 28 and interconnected rod 32 unsupported. It should be understood that the disclosed method may be practiced with additional steps, and that the order of steps may be varied as evident from the discussion herein, without departing from the invention. Industrial Applicability It is believed removal of the unit 58 from the engine block 14 is sufficiently clear from the above. However, a brief discussion follows so that one may more fully appreciate the advantages of servicing an engine in the disclosed manner. Initially, with the head of the engine 10 removed, it is desirable and may even be necessary to rotate the crankshaft 37 and position the piston 26 at a desired travel point in the cylinder bore 18 to facilitate positioning the tool and completing the removal process. The tool 12 is inserted into the bore preferably far enough such that it will not be over the carbon build-up or wear step. Experience will indicate the desired initial position of the piston for a particular engine and tool. It is suggested that the piston be positioned such that, at the time of lifting the liner from the block, it will be adjacent or in contact with the tool 12, or cap if used, to facilitate establishing the vacuum. Where the piston 26 is to be used to move the tool 12 and liner 16, its initial position is preferably on the upstroke such that it will be adjacent or in contact with the tool. This minimizes the resistance to piston movement from air trapped by the tool in bore 18 which must leak past the rings. One practice which works well is to insert the tool in the cylinder bore 18 and rest it on the piston. For the tool of FIG. 3, the bottom segment 40 would rest on the piston, while for the tool of FIG. 5, the base 84 of the driver 82 would rest thereon. This permits one to simply rotate the crankshaft 34 to move the piston and tool to desired positions prior to diametrically expanding the tool, if necessary, and then to expand the tool in contact with the piston to facilitate the removal process. The tool 12 is "expanded" to establish the frictional fit. The air-tight fit is simultaneously established without additional "sealing" such that the tool may be satisfactorily used during the entire removal process. It may be necessary for sufficient vacuum, however, to use an O-ring at the head of the bolt 48 in the tool of FIG. 3, or to otherwise prevent air flow along the bolt. It will be noted that the bolt head being recessed in the counterbore of the arbor 46 eliminates piston damage from the bolt head 26 and holds the bolt from movement during tool expansion. Also, the arbors 48 being keyed to their respective segments 40 prevents relative movement therebetween. In the tool of FIG. 5, the elastomeric cover 76 performs the function of sealing to establish the vacuum. The cylinder liner 16 is next unseated to break the interference fit by applying sufficient force to the tool 12 as previously explained. If desired, the tool may then be removed and used to unseat the next liner on the engine for which a piston 26 is in proper position. A cap is fitted in the freed liner so that the vacuum may be established for completing removal. Otherwise, the tool is maintained in place. Next, the rod cap 38 is removed and the liner or tool where present grasped to pull the liner free of the block 14. The oversized washer 52 shown with the tool of FIG. 3 or the eye portion of the tool of FIG. 5, for example, is a convenient point at which to connect the tool being used to an overhead device if needed for lifting purposes. With the partial vacuum, the piston 26, rings 28 and rod 32 will, without being supported, move free of the engine 10 together with the liner for removal as the unit 58. Other aspects, objects and advantages will become apparent from a study of the specification, drawings and appended claims. I claim: 1. A pulling tool for inserting into and frictionally engaging a cylinder liner for removal of said cylinder liner from an engine block in response to a force applied on said tool, comprising:a segmented mandrel having a circumferential wall, first and second ends and a plurality of longitudinal slots, said circumferential wall having an outer cylindrical surface defining the diameter of said mandrel and a tapered inner surface defining an aperture opening on said first end and being divided into segments by said slots; a driver having a base and a body portion, said body portion having a frusto-conical shape and being insertable into said aperture and movable to succeeding positions at which said frusto-conical shape increasingly forcibly urges against said tapered inner surface of said mandrel to force said outer surface to a correspondingly larger diameter, said base extending across said first end of said mandrel when said driver is inserted in said mandrel; a cap at said second end of said mandrel; means cooperating with said driver and said cap to move them toward each other forcing said body portion against the tapered inner surface of the mandrel to expand the mandrel radially; and a flexible, elastomeric cover attached to and extending over substantially the entire outer cylindrical surface of the mandrel for frictionally engaging the cylinder liner, the cover being supported by its engagement with the mandrel. 2. The tool, as set forth in claim 1, wherein the means cooperating with said driver and cap is a threaded rod extending from an opening in said driver and an opening in said cap. 3. The pulling tool, as set forth in claim 1, including means for sealing the mandrel radially inwardly of the elastomeric cover to provide an airtight seal. 4. The pulling tool, as set forth in claim 1, wherein the flexible elastomeric cover extends over the outer cylindrical surface of the mandrel and the second end of the mandrel for covering the slots to provide an airtight seal. 5. The pulling tool, as set forth in claim 1, wherein there is a single driver and wherein the tapered inner surface of the mandrel extends a major portion of the length of the mandrel from the first end. 6. The pulling tool, as set forth in claim 1, wherein the base of the driver is substantially as large as the circumferential wall at its second end. 7. The pulling tool, as set forth in claim 1, wherein the driver has an opening having threads that end short of the base. 8. A tool for inserting into a tubular member and for gripping said tubular member in response to a force applied on said tool, comprising:a longitudinally-segmented, hollow mandrel having a circumferential wall and first and second ends, said circumferential wall having an outer surface defining a diameter of the mandrel and a tapered inner surface; a driver having a base and a frusto-conical body portion insertable into said hollow mandrel and into engagement with its tapered inner surface, the frusto-conical body portion being movable to succeeding positions at which said frusto-conical body portion increasingly forcibly urges said outer surface to a correspondingly larger diameter; means for applying a force on said driver to force it into the hollow mandrel and to said succeeding positions; and a flexible cover on the outer surface of said circumferential wall to frictionally engage said tubular member. 9. The tool, as set forth in claim 8, wherein said flexible cover is an elastomeric material. 10. The tool, as set forth in claim 8, wherein said flexible cover engages the entire outer surface of said mandrel. 11. The tool, as set forth in claim 8, including a cap at said second end of said mandrel, and wherein said means for applying force on said driver is a threaded rod extending from said driver at said first end to the cap.

1985-04-22

en

1986-05-20

US-88487186-A

Fiber optic modal coupler, interferometer and method of coupling spatial modes using same ABSTRACT A modal coupler, for coupling between first and second order modes of an optical fiber, comprises a single continuous strand of optical fiber, and a device for applying stress to the optical fiber at spaced intervals along the fiber. The stress deforms the fiber and abruptly changes the fiber geometry at the beginning and end of each stressed region. The change in fiber geometry causes coupling of light from the fundamental mode to the second order mode. The coupler, under certain conditions, exhibits polarization dependence, and thus, it may be utilized as a fiber optic polarizer. In addition, the device couples coherently, and may be used in interferometric systems. This application is a continuation of application Ser. No. 556,306, filed Nov. 30, 1983, now abandoned. BACKGROUND OF THE INVENTION The present invention relates generally to fiber optic directional couplers, and more specifically, to devices which selectively couple light energy between the modes of an optical fiber. Fiber optic directional couplers provide for the transfer of optical energy traveling in one fiber optic waveguide to another. Such couplers are useful for a variety of applications, e.g. in fiber optic sensors. As is well known in the art, a single optical fiber may provide two or more waveguides under certain conditions. These waveguides are commonly referred to as the normal modes of a fiber, which may be conceptualized as independent optical paths through the fiber. Normal modes have unique electric field distribution patterns which remain unchanged, except for amplitude as the light propagates through the fiber. Additionally, each normal mode will propagate through the fiber at a unique propagation velocity. The number of modes which may be supported by a particular optical fiber is determined by the wavelength of the light propagating therethrough. If the wavelength is greater than the "cutoff" wavelength, the fiber will support only a single mode. If the wavelength is less than cutoff, the fiber will begin to support higher order modes. For wavelengths less than, but near cutoff, the fiber will support only the fundamental, or first order mode, and the next, or second order mode. As the wavelength is decreased, the fiber will support additional modes, e.g. third order, fourth order, etc. These first order, second order, third order, etc. normal modes are commonly referred to as the "spatial" modes of the fiber. Each of spatial the normal modes (e.g. first order, second order, etc.) are orthogonal, that is, there is no coupling between the light in these modes. In addition, each of the spatial normal modes includes two orthogonal polarization modes, which may be defined e.g. as the linear vertical polarization mode and the linear horizontal polarization mode. The orientation of the electric field vectors of the modes defines the polarization of the light in the mode, e.g. linear vertical, or linear horizontal. A more complete discussion of these modes, and their corresponding electric field patterns, will be provided below. SUMMARY OF THE INVENTION The present invention comprises an all fiber modal coupler for transferring optical power from a fundamental, or first order mode, to the second order mode of an optical fiber, in a controlled manner. The coupler is advantageously quite simple in structure, and includes an optical fiber, having a core surrounded by a cladding, and a light source for introducing a lightwave into the optical fiber, for propagation therethrough. The lightwave produced by the light source has a wavelength below the cutoff wavelength, to cause the lightwave to propagate through the fiber in both first and second order modes. The invention additionally comprises a device for applying stress to the optical fiber at spaced intervals along the fiber to provide a series of stressed regions which cause coupling of light energy between the first and second order modes. In the preferred embodiment, this stress applying device comprises a plate having a series of grooves cut on one face thereof to provide a series of ridges. These ridges are oriented perpendicular to the longitudinal axis of the fiber, and a force is applied thereto. The force is sufficient to asymmetrically deform the fiber at the stressed regions to cause a relatively abrupt change in fiber geometry at the boundary between each of the stressed regions and the adjacent unstressed regions. This abrupt change in fiber geometry causes coupling between the first and second order modes of the fiber. In the preferred embodiment, the beginning of one stressed region is separated by one beat length from the beginning of the next adjacent stressed region. Further, the length of each of these stressed regions is preferably one-half beat length so that each of the unstressed regions will also be one-half beat length in length. The term "beat length" as used herein, is mathematically defined as the wavelength of the lightwave propagating through the fiber divided by the difference in refractive indices of the first and second order modes. Stated another way, the beat length is the distance required for the first and second order modes to separate in phase by 360°, due to their dissimilar propagation velocities. Test results show that the coupler of the present invention exhibits surprising anomalous behavior when compared to conventional coupled mode theory. For example, conventional coupled mode theory predicts that the coupler should be wavelength dependent. However, the test results show that the coupling is substantially independent of the wavelength of the light over a broad range. The coupler also exhibits another type of anomalous behavior, namely, that as the number of stress regions is increased, the coupling becomes polarization dependent. For example, using a thirty ridge device, 40 dB coupling of the vertically polarized fundamental mode to the higher order mode was achieved, whereas with the same set up, the horizontally polarized fundamental mode coupled only 4 dB of power into the higher order mode, yielding a 36 dB extinction ratio between the vertical and horizontal polarizations in the fundamental modes. With a ten ridge device, however, very little discrepancy between the coupling of the two polarizations was observed. The polarization dependence of the coupler may be advantageously utilized to provide an all fiber optic polarizer. Thus, in another embodiment of the invention, a second order mode stripper is provided at the coupler output to remove the higher order modes into which the light has been coupled. Assuming that the vertical polarization is well coupled and the horizontal polarization is poorly coupled, input light which is horizontally polarized would be passed by the coupler and mode stripper, while vertically polarized light would be effectively blocked. Additionally, the invention may be used as a Mach-Zehnder interferometer by mounting two modal couplers on a single strand of fiber. In such arrangement, a higher order mode stripper is preferably placed on the fiber after the second modal coupler, i.e. at the output of the interferometer, so that only the residual fundamental mode power is output to a detector. By way of specific example, the couplers may be set to about 50/50 coupling and the wavelength of the input light may be varied slightly in order to tune the relative phase difference of the two modes between the couplers. In one test of this device, a dynamic range of the power in the fundamental mode of 30 dB was measured as the fiber was thermally expanded, thereby demonstrating that the device couples coherently, and is suitable for use in interferometric systems. BRIEF DESCRIPTION OF THE DRAWINGS These and other features of the present invention are best understood through reference to the drawings, in which: FIG. 1 is a schematic diagram illustrating the electric field patterns of the first and second order modes, LP01 and LP11, respectively; FIG. 2 is an exploded, perspective view of the modal coupler of the present invention; FIG. 3 is a cross sectional view, taken along the lines 3--3 of FIG. 2, showing the shape of the ridges; FIG. 4 is a schematic diagram showing a pair of ridges pressed against the optical fiber so as to slightly deform the fiber and cause abrupt changes in fiber geometry at the beginning and end of each ridge; FIGS. 5a-f are diagrams showing the electric field distribution relative to the fiber axis at various points along the optical fiber of FIG. 4; FIG. 6 is a graph of coupled power versus wavelength, illustrating the polarization dependence and wavelength independence of the coupler, as contrasted to conventional coupled mode theory; FIG. 7 is a schematic diagram showing the circuit arrangement utilized to test the performance of the coupler of the present invention, and to obtain the data points for the actual coupling curves shown in FIG. 6; FIG. 8 is a schematic diagram of a fiber optic polarizer which utilizes the coupler of the present invention; and FIG. 9 is a schematic diagram of a single fiber Mach-Zehnder interferometer utilizing a pair of couplers constructed in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The coupler of the present invention comprises a single strand of nonbirefringent single mode optical fiber operated at a wavelength above cutoff such that the fiber supports both fundamental and second order guided modes. Coherent coupling between these modes is achieved by stressing the fiber at periodic intervals, e.g. once per beat length. The fundamental and second order guided modes provide two orthogonal paths through the fiber which permits the device to be used as a two channel medium, e.g. as in in-line Mach-Zehnder interferometer, and as a two channel medium in data systems. Before discussing the structural details and operational theory of the present invention, a brief summary of mode theory will be presented, to provide background for more fully understanding of the invention. Mode Theory When a single mode fiber is used at a wavelength below cutoff, it will begin to guide higher order modes. The wavelength at cutoff (λc) is related to the fiber geometry, and may be calculated utilizing the following equation: ##EQU1## Where r is the core radius, nc is the refractive index of the core, and ncl is the refractive index of the cladding. If the indices of the core and cladding are approximately equal, then it can be shown that the LP11 modes are the next modes (i.e. the second order modes) beyond the fundamental modes LP01 which are guided. These modes are defined and described in detail in an article by D. Gloge, entitled "Weakly Guiding Fibers", Applied Optics, 10, 2252 (1971). FIG. 1 shows the field patterns of the two modes in the fundamental LP01 set of modes and the four modes in the second order LP11 set of modes. The arrows indicate the direction of the electric field vectors at a particular instant in time. For the LP01 fundamental modes, the electric field vector is either vertical, representing vertically polarized light or horizontal, representing horizontally polarized light. However, for the LP11 second order modes, the vertical polarization and the horizontal polarization each have two electric field patterns. Further, each of the second order mode field patterns is comprised of two lobes. In one of these field patterns, the electric field vectors of the lobes are perpendicular to the zero electric field line (ZFL), while in the other electric field pattern, the electric field vectors of the lobes are parallel to the zero electric field line (ZFL). The zero electric field line is simply a line between the two lobes in each of the second order mode patterns which represents zero electric field amplitude. Similarly, the horizontally polarized second order modes have electric field vectors oriented either parallel to the ZFL or perpendicular to the ZFL, as shown in FIG. 1. Each of the six electric field patterns in FIG. 1, namely, the two LP01 patterns and the four LP11 patterns, are orthogonal to each other. Thus, the six patterns may be viewed as independent optical paths through the fiber, which ordinarily do not couple with each other. If the indices of the core and the cladding are approximately equal, the two LP01 modes will travel through the fiber at approximately the same propagation velocity, and the four second order LP11 modes will travel through the fiber at approximately the same propagation velocity. However, the propagagtion velocity for the fundamental LP01 set of modes, will be slower than the propagation velocity for the second order LP11 set of modes. Thus, the two set of modes LP01, LP11, will move in and out of phase with each other as the light propagates through the fiber. The propagation distance required for the two sets of modes to move out of phase by 360° is commonly referred to as the beat length of the fiber, which may be mathematically expressed as: ##EQU2## where λ is the optical wavelength in a vacuum and Δn is the difference in the effective refractive indices of the two sets of modes. Coherent power transfer between the two sets of modes, LP01 and LP11, can be achieved by producing periodic coupling which matches the beat length of the modes. Such coupling can be implemented by periodically deforming the fiber with the device shown in FIG. 2. Structural Features of the Coupler FIG. 2 shows the coupler of the present invention in perspective view. A polished, flat surface 10 is machined on a metal or plastic block 11. The surface 10 should be smooth and flat to within a few microns. A nonbirefringent optical fiber is disposed between the surface 10 and the undersurface of a second block 14, which has a multiple ridge region 12, machined thereon. The ridge region 12 provides a series of ridge-shaped coupling elements which, when pressed against the fiber so as to squeeze the fiber between the blocks 11, 14, stress the fiber at periodic intervals to cause light to be coupled between the modes. Referring briefly to FIG. 2, there is shown a cross section of the ridged region 12 in which a plurality of ridges 16 are formed. The ridges 16 are formed by machining the block 14 to provide spaced parallel notches or grooves 17, such that there is formed a plurality of polished ridge surfaces 18, having a width, W, and a separation, S, between the edges of adjacent ridges. In the embodiment shown, the width, W, and separation, S, are each one-half beat length of the fiber for light at the particular frequency which is utilized. In theory, each ridge can be any odd multiple of one-half beat length, and each separation can be any odd multiple of one-half beat length. The cross section of the notches 17 in the preferred embodiment is rectangular, since that is the easiest shape to machine. However, this shape is not critical; any shape which yields a flat surface 18 on the ridges 16 will be satisfactory, providing that the height, H, of the notch 17 is sufficient to maintain stress when the material of the ridge 16 is deformed by application of force to the fiber. In a preferred embodiment, the block 14 is made of a hard plastic, Deltrin™. This plastic deforms more readily than glass, and thus, avoids damage to the fiber. For complete power transfer, it is important that the ridges apply stress to the fiber so as to provide alternate regions of deformation and no deformation in the fiber. Further, it has been found that the force of about 3 kg applied to the block 14 is required to achieve maximum coupling, regardless of the number of ridges 12. The overall length of the device is not critical, however, in the embodiment shown, the length is on the order of two to three inches. Returning to FIG. 1, the block 14 has a plurality of holes 20 which are spaced in a pattern to receive a set of pins 22 projecting from the flat surface 10 in a matching pattern. The block 14 may be slid toward and away from the flat surface 10 along the pins 22. The pins 22 are so aligned and the ridges 16 are oriented such that the edges of the ridges 16 are transverse to the longitudinal axis of a fiber 24 which is held on the flat surface 10 by a pair of fiber holding plates 26. Thus, the edges of the ridges 16, illustrated by the reference numeral 27 in FIG. 2, the transverse to the longitudinal axis of the fiber 24. The pins 22 also serve to prevent rocking of the block 14 to prevent uneven pressure from being applied to the fiber 24. If desired, the ends of the pins 22 may be threaded for receiving respective nuts (not shown), and respective coil springs (not shown) may be placed between the nuts and the upper block 14 in order to control the pressure exerted by the top plate 14 on the fiber 24. The holding plates 26 are disk-shaped with a V-shaped cutout therein for receiving the fiber, and are mounted in respective circular apertures of respective end plates 28, which are mounted at the ends of the block 11 so that they are perpendicular to the flat surface 10. However, any other suitable method of holding the fiber may be used alternatively. Determining the Fiber Beat Length To properly size and space the ridges 16, the beat length of the non-birefringent fiber 24 must be known. Unlike birefringent fiber, the beat length of the non-birefringent fiber cannot be directly observed, and a more elaborate procedure is necessary. The particular fiber used as the fiber 24 in the preferred embodiment was a single length of Corning single mode fiber, having an outer diameter of approximately 125μ, a cutoff wavelength of approximately 650 nm, a mean index for the core and the cladding of 1.458, a step index profile with a core index of 1.4593, and a cladding index of 1.4567, and a core radius of 2.9μ. Vertically polarized light was input to the fiber by offsetting the input beam relative to the central axis of the fiber such that approximately equal amounts of the vertically polarized fundamental LP01 mode and the vertical-normal LP11 mode (See FIG. 1) were launched. A continuous wave dye laser was used so that the input wavelength could be varied. The fiber output was displayed on a screen and the interference pattern between the two guide modes was observed. As the input wavelength was scanned from 570 nm to 610 nm the output pattern fluctuated periodically (i.e. repeated itself) 40 times. Those skilled in the art will understand that, from this data, the difference between the refractive index between the two sets of modes (i.e. the first and second order modes) may be calculated using the simplified Eigenvalue equations for a cylindrical step index fiber, as discussed in Chapter 8 of Light Transmission Optics, Dietrich Marcuse, 2nd edition, Van Nostrand Reinhold Co., 1982 (See especially Section 8.6). For the above-described fiber, a value for the refractive index difference was calculated to be 0.001342, yielding a beat length, calculated in accordance with equation (2), above, of 0.447 mm for a wavelength of 600 nm. The preferred embodiment was constructed as a thirty ridge structure with 0.203 mm wide gaps between ridges, and 0.229 mm wide ridges, yielding a ridge periodicity of 0.432 mm. The gaps and ridges were not equal in length due to fabrication limitations. The wavelength required for a beat length of 0.432 mm (equal to the ridge periodicity) was calculated to be 608 nm. Theory of Operation As shown in FIG. 4, application of a vertical force, F, to the plate 14 presses the ridges 16 against the fiber 24, and thus, causes the portions of the fiber 24 beneath the ridges 16 to be stressed and asymmetrically deformed. The ridges thus cause abrupt changes in fiber geometry at the beginnings and ends of the stressed regions. For purposes of explanation, these abrupt changes in fiber geometry may be viewed as boundaries 44 at which the center line or longitudinal axis 46 of the fiber is abruptly shifted in the direction of the applied force. Such abrupt shifting of the fiber axis 46 causes light to be coupled from the fundamental LP01 set of modes to the second order LP11 set of modes at each of the boundaries 44. The particular second order mode to which the light is coupled depends upon the direction of force relative to the polarization of the applied light. For example, if the input light in the fundamental is vertically polarized, such light will uniquely couple to the vertical-perpendicular second order mode, and not to the vertical parallel second order mode, the horizontal-normal second order mode, or the horizontal parallel second order mode (see FIG. 1). Assuming now that the force is still vertical, but the input light is horizontally polarized in the fundamental mode, such light will couple uniquely to the horizontal parallel second order mode and not to any of the other second order modes. To more fully illustrate the manner in which light is coupled to the second order modes at each of the boundaries 44, the electric field distribution of a lightwave will be traced as it propagates through the fiber 24, from the left side to the right side, as viewed in FIG. 4. It will be assumed that the lightwave is vertically polarized and launched in the fundamental mode. As shown in FIG. 5a, just before the lightwave arrives at the first boundary 44, e.q. when it is at the location A in FIG. 4, the electric field distribution, illustrated by the curve labeled 52, will be symmetric about the center line 46, and well confined to the fiber core. As the lightwave crosses the boundary 44, to the location B in FIG. 4, the electric field distribution shown by the curve 52 will appear the same, relative to a fixed observer, since the electric field is continuous across the boundary 44, in accordance with Maxwell's equations. However, the fiber axis 46 is now shifted due to the deformation of the fiber 24 caused by the ridges 16, so that the curve 52 is no longer symmetrical about the axis 46, as shown in FIG. 5b. The curve 52, shown in dotted lines in FIG. 5b thus decomposes back into two normal modes, namely a fundamental mode, illustrated by the curve 54, and a small second order mode, illustrated by the curve 56. In other words, the nonsymmetric curve 52 is the sum of the first and second order normal mode curves 54, 56, respectively. Thus, at the first boundary 44, the decomposition of the curve 52 causes a small amount of fundamental mode light to be transferred to the second order mode. Since the ridge 16 is one-half beat length long, as the light propagates from location B to location C in FIG. 4, the light in the second order mode will undergo a phase shift of 180° relative to the light in the first order or fundamental mode. Accordingly, as the point C in FIG. 4, the electric field distributions shown by the curves 54 and 56 will be the same, except that they are 180° out of phase, as illustrated in FIG. 5c. When the lightwave crosses the second boundary 44, and arrives at the point D in FIG. 4, the axis 46 of the fiber shifts back to an unstressed undeformed condition, and the modes 54, 56 are again nonsymmetrical with regard to the axis 46. Consequently, the light in the fundamental mode 54 again decomposes into a fundamental mode 58 of lesser amplitude than the mode 54, and a second order mode which is in phase with the second order mode 56, thereby yielding a resultant second order mode 60, as shown in FIG. 5d, which has an increased amplitude relative to the mode curve 56. It will be recognized that the 180° phase change between the modes during propagation from point B to point C, advantageously causes the light coupled from the fundamental to the second order mode to add to that previously coupled, such that the second order mode coupling is cumulative, rather than destructive. As the light propagates from point D to point E, the first and second order modes undergo another 180° phase change, such that when the light reaches point E in FIG. 4, the electric field distribution is as shown in FIG. 5e. At the third boundary 44, the fiber axis again shifts, and the same process repeats, so as to cause light from the fundamental mode to be coupled to the second order mode, as illustrated by the curves 62, 64 in FIG. 5f. Thus, it may be seen from the foregoing that the abrupt boundaries 44 provide coupling locations at which a fraction of energy from the fundamental mode is coupled to the second order mode. From the above discussed coupled mode analysis, one would expect the performance of the coupler to be dramatically reduced when the spacing between the beginning of one ridge and the beginning of the next ridge 16 is not one beat length (or an integer multiple thereof). Calculations show that, in theory, the performance of the coupler of the present invention should generally follow the curve 70 of FIG. 6. For the preferred embodiment, maximum coupling was expected to occur at a wavelength of 608 nm, which yields a beat length equal to the ridge periodicity of 0.432 mm. At wavelengths above or below 608 nm, the curve 70 predicts that the coupling should rapidly decrease. The performance of the thirty ridge coupler of the preferred embodiment was tested utilizing the circuit arrangement shown in FIG. 7. A frequency tunable dye laser 72 was used to produce the source light. This source light was impressed upon a beam splitter where approximately one-half of the light was directed to a detector 74, while the other one-half was impressed upon a lens 76, which focused the light for introduction into an optical fiber 78. The dye laser 72 was operated in a wavelength range below cutoff such that only the first and second order modes were launched in the fiber 78. The fiber 78 was wrapped around a 1.3 centimeter diameter post at the input and to provide a mode stripper 80 for stripping out any second order modes that were launched. This type of mode stripper is well known in the art, and is discussed in an article by Y. Katsuyama, entitled "Single Mode Propagation in a Two Mode Region of Optical Fiber by Using Mode Filter", Electronics Letters, 15, 442 (1979). An all fiber polarization controller 82 was formed in the fiber 78 after the mode stripper 80. A polarization controller of this type is disclosed in U.S. Pat. No. 4,389,090, issued June 21, 1983. The purpose of the polarization controller 82 is to vary the polarization of the guided input light such that it is e.g. linear-vertical. The fiber 78 then passes through a ridge structure such as that described in reference to FIGS. 2 and 3 to form the thirty ridge modal coupler 84 of the preferred embodiment. The fiber is then wrapped around another post to form a second mode stripper 86, identical to the mode stripper 80. At the output end of the fiber, the output light is directed against a collimating lens 88, which impresses the output light upon a detector 90. The two detectors 74, 90 are then connected by lines 92, 94, respectively, to a ratiometer 96. This ratiometer 96 displays, as an output, the ratio of the output light intensity, as measured by the detector 90, to the input light intensity, as measured by the detector 74. In operation, the light input at the input end of the fiber 78 is first stripped of second order modes by the mode stripper 80, so that when the light enters the polarization controller, only the fundamental mode is present. The polarization controller is then used to adjust the polarization of the input light so that it is e.g. vertically linerly polarized upon entering the modal coupler 84. The coupler 84 is operated by appling a force to the upper ridged plate, as discussed above, to cause coupling of light from the fundamental mode to the second order mode. After leaving the coupler 84, the light is stripped of second order modes by the mode stripper 86, and any residual light in the fundamental mode is impressed upon the detector 90 through the lens 88. The wavelength of the input light was then varied from 570 nm to 612 nm to determine the sensitivity of the coupler 84 to variations in wavelength. As expected, maximum coupling occurred at a wavelength of 608 nm. Measurements indicated that the coupling of the vertically polarized fundamental mode to the second order mode (i.e. the vertical-perpendicular second order mode) was quite good, and that less than -40 dB of residual power was left in the fundamental mode at the output end of the fiber 78, which corresponds to 99.99% of the power being coupled from the fundamental to the second order mode. Insertion loss was measured by removing the output mode stripper and measuring the total power in the fiber while the coupler was operating. By comparing this value to the power in the fiber when the coupler was not operating, a loss of 9% was measured. When the wavelength of the source light was varied from 608 nm, however, the coupler 84 exhibited unexpected behavior. Specifically, the coupling of the vertically polarized light remained at high level throughout the wavelength range from 570 to 612 nm, as illustrated by the curve 98 in FIG. 6, and thus, the coupling did not follow the theoretical curve 70. [The triangles on the curve 98 indicate actual data points.] The tests described above in reference to FIG. 7 were repeated, this time for linearly horizontally polarized input light. As indicated by the curve 100 of FIG. 6, coupling of the horizontal polarization was relatively constant over the wavelength range, and peaked at 608 nm. [Dots on the curve 100 represent actual data points.] Thus, the coupling curves 98, 100 for vertically and horizontally polarized light, respectively, were both broad and did not follow the predicted coupled mode theory curve 70. It is significant, however, that the curve 100 for horizontally polarized light exhibits further anomalous behavior in that the amount of coupling is much less than for vertically polarized light, being on the order of only 4 dB. For both the curves 98 and 100, a vertical force was applied to the coupler 84 to cause coupling from the fundamental to the higher order modes. Thus, the coupler of the present invention exhibits anomalous behavior when compared to conventional coupled mode theory, in that (1) the coupling is relatively constant for different wavelengths, and (2) such coupling is polarization dependent. Interestingly, the polarization dependence of the coupler appears to be related to the number of ridges 16 (FIG. 3). For example, when a ten ridge device is used, the discrepency between the coupling of the two polarization diminishes, and both polarizations couple on the order of b 99% of their power into the second order mode. For an eighty ridge device, neither polarization couples better than 20% of its power. The reasons for this surprising behavior of the coupler are not fully understood. It is theorized that the coupler does not follow conventional mode theory for two reasons: (1) because the LP11 modes only approximate the true normal modes of the fiber, and (2) because the normally nonbirefringent fiber becomes birefringent when squeezed by the ridges 16 (FIG. 3). Use of the Coupler as a Fiber Polarizer The above-described polarization dependence of the coupler may be advantageously utilized to provide an in-line all fiber bidirectional polarizer. As shown in FIG. 8, such a polarizer may comprise a single continuous strand of fiber 102 having end portins 104, 106. Mode strippers 108, 110 are located at the end portions 104, 106, respectively, and a modal coupler 112, such as the thirty ridge coupler of the preferred embodiment, is interposed between the mode strippers 108, 110. Preferrably, the number of ridges 16 on the modal coupler 112 are selected to maximize coupling in one polarization, (e.g. the vertical polarization) and minimize coupling of the orthogonal polarization (e.g. the horizontal polarization). As discussed previously in reference to FIGS. 7 and 8, using the thirty ridge device, 40 dB coupling of the vertically polarized fundamental mode to the higher order mode was achieved, while only 4 db of the horizontally polarized fundamental mode was coupled to the higher order mode. Consequently, such a modal coupler yields a 36 dB extinction ratio between the vertical and horizontal polarizations in the fundamental modes. In operation, light is input to one end portion of the fiber 102, e.g. the end portion 104. Second order modes are stripped by the mode stripper 108 so that only the fundamental mode enter the modal coupler 112. It will be assumed that vertical polarizations are well coupled, while horizontal polarizations are poorly coupled. Thus, if the light input to the coupler 112 is vertically polarized, substantially all of it will be coupled to the second order mode, and such light will be stripped by the mode stripper 110 so that the amount of light reaching the output fiber portion 106 is virtually zero. On the other hand, if the polarization of the input light entering the coupler 112 is horizontal, only a fraction of the light will be coupled to the second order mode and stripped by the mode stripper 110. Thus, much of the light will remain in the fundamental mode and propagate to the output end portion 106 of the fiber 102. As indicated above, with a thirty ridge device, a 36 db extinction ratio between the vertical and horizontal polarizations in the fundamental modes may be expected, yielding an all-fiber polarizer with performance comparable to that of thin polarizing films. Use of the Coupler as a Mach-Zehnder Interferometer As shown in FIG. 9, a Mach-Zehnder interferometer may be constructed by mounting two modal couplers 120, 122 in spaced relationship along a single continuous strand of optical fiber 124. Source light is produced by a laser 126, which is optically coupled to introduce light into the input end of the fiber 124. The source light from the laser 126 is first passed through a mode stripper 128, formed on the fiber 124, to remove second order modes. The light is then passed through a polarization controller 130, which is used to adjust the polarization of the light to e.g. linear-vertical. The guided source lightwave then enters the first coupler 120, which is set to approximately 50/50 coupling, such that half of the power is coupled to the second order mode. After propagating a distance through the fiber 124, the light then enters the second coupler 122. The light exiting the second coupler 122 passes through a mode stripper 132, formed on the fiber 24, to strip second order modes. The light then exits the fiber 124 and is impressed upon a detector 134 which outputs an electrical signal on a line 136. In the embodiment shown, the length of fiber between the modal couplers 120, 122 and the wavelength of the source light are selected such that, at the input end of the second coupler 122, there is zero phase difference between the light in the first order and second order modes. It will be recognized that if the phase difference between the modes is zero upon entering the coupler 122, the coupling to the second order mode will be at a maximum, while if the first and second order modes are 180° out of phase, the coupling by the coupler 122 will be at a minimum. Accordingly, with zero phase difference at the input end of the coupler 122, maximum coupling to the second order mode will occur. The second order mode is then stripped by the mode stripper 132, and the signal at the detector, i.e. the residual fundamental mode power, will be at a minimum. The amount of coupling of the coupler 122 may be varied until a minimum in the residual fundamental power is observed. The coupling is then fixed at this value and the portion of fiber between the couplers 120, 122 is exposed e.g. to an environmental quantity to be measured, such as temperature. Exposure to temperature will change the length of the fiber between the couplers 120, 122, and thus, cause the light in the first and second order modes to move out of phase upon entering the coupler 122. This will cause the coupling to the second order mode to decrease, and thus, the residual power in the fundamental mode, as measured by the detector, will increase. The output signal on the line 136 from the detector 134, therefore, provides a direct indication of the magnitude of the sensed environmental quantity. In one experiment, a dynamic range of the power in the fundamental mode of 30 dB was measured as the fiber was thermally expanded. This demonstrates that the device couples coherently and can be used in interferometric systems. Thus, the modal coupler of the present invention has a variety of uses, e.g. as a single fiber polarizer, or a single fiber Mach-Zehnder interferometer. Additionally, the coupler may be used in a two channel data system. These uses are exemplary only, and other uses will be apparent to those skilled in the art. What is claimed is: 1. A modal coupler, comprising:an optical fiber, having a longitudinal axis; a light source for introducing a lightwave into said optical fiber, said lightwave having a wavelength selected such that said fiber supports first and second spatial modes for said wavelength, said fiber having a beat length for said modes; and a member for applying force to said optical fiber at spaced intervals along said fiber axis, said force causing portions of said longitudinal axis to be displaced relative to other portions of said longitudinal axis such that said longitudinal axis shifts at each of said intervals in response to said force to cause coupling between said modes, said intervals spaced in accordance with the beat length for only said first and second spatial modes of said fiber, so that said coupling is cumulative between said first and second spatial modes. 2. A modal coupler, as defined in claim 1, wherein said force applied by said member to said fiber produces a series of spaced stressed regions along said fiber. 3. A modal coupler, as defined in claim 2, wherein said coupling occurs at locations along said fiber corresponding to a boundary of each of said stressed regions. 4. A modal coupler, as defined in claim 2, wherein each of said stressed regions is adjacent to another of said stressed regions, and wherein a boundary of one of said stressed regions is separated by one beat length from the corresponding boundary of an adjacent stressed region. 5. A modal coupler, as defined in claim 2, wherein said stressed regions are one-half beat length long and said stressed regions are separated by one-half beat length. 6. A modal coupler, as defined in claim 2, wherein the number of said stressed regions is selected to cause preferential coupling of one polarization relative to another polarization. 7. A modal coupler, as defined in claim 1, wherein said fiber is substantially nonbirefringent. 8. A modal coupler, as defined in claim 1, wherein said first and second modes of said fiber are the only spatial modes supported by said fiber. 9. A modal coupler, as defined in claim 1, wherein said coupler is bidirectional such that said coupling is the same regardless of the direction of propagation of said lightwave through said fiber. 10. A fiber optic apparatus, comprising:an optical fiber having a longitudinal axis; a light source for introducing light into said fiber at a wavelength selected to cause said fiber to support first and second spatial modes, said fiber having a beat length for said first and second modes; a modal coupler, mounted on said optical fiber, for coupling light between the first and second spatial modes at spaced intervals along said fiber axis, said intervals spaced in accordance with the beat length for only said first and second spatial modes of said fiber, such that said coupling is cumulative between the first and second spatial modes of said fiber, said modal coupler adapted to preferentially cumulatively couple light of a first polarization relative to light of a second polarization, such that any of said cumulatively coupled light of said first polarization is coupled from one of said modes to the other of said modes to a greater extent than any of said cumulatively coupled light of said second polarization; and means for outputting light only from one of said modes of said fiber to cause said apparatus to output light substantially in only one of said polarizations. 11. A single fiber Mach-Zehnder interferometer for detecting interference between two light signals, comprising:a single strand of optical fiber having a longitudinal axis; and a light source for introducing light into said fiber at a wavelength selected to cause said fiber to support first and second spatial modes, said light being divided between said modes to provide said two light signals, said fiber having a beat length for said first and second modes, said modes providing respective optical paths for propagation of said light signals; a modal coupler for coupling light between said first and second modes at plural intervals along said fiber axis, said intervals spaced in accordance with the beat length for only said first and second modes, such that said coupling is cumulative between the first and second spatial modes of said optical fiber, said coupler mounted along the axis of said optical fiber such that said modes are coupled after propagation of said light signals through a substantial length of said fiber, said coupling causing said signals to interfere; and means for detecting light from one of said first and second modes, so as to detect optical path length changes in the optical paths. 12. A method of coupling light between first and second order modes of an optical fiber, comprising:introducing light into said optical fiber at a wavelength selected to cause said fiber to support only said first and second order modes; applying force to said fiber at plural intervals along second order modes, said intervals spaced such that said periodic coupling is cumulative; and selecting the number of said intervals to provide preferential coupling for a first polarization relative to a second, orthogonal polarization from one of said modes to the other of said modes. 13. A modal coupler, comprising:a single multimode optical fiber for propagating light of first and second orthogonal polarizations, said fiber having a longitudinal axis; and a member for applying force to said multimode fiber at plural intervals along said axis, said intervals spaced such that said coupling is cumulative between two spatial modes of said multimode fiber, the number of said intervals selected to cause said coupling to be substantially greater for said first polarization than for said second polarization. 14. A mode coupler, as defined by claim 13, wherein said two modes comprise exclusively first and second order modes of said fiber. 15. A method of coupling light exclusively between two spatial modes of an optical fiber, said optical fiber having a longitudinal axis, said method comprising;introducing a light wave into said optical fiber, said lightwave having a wavelength selected such that said fiber supports first and second spatial modes for said wavelength; applying force to said optical fiber at spaced intervals along said fiber axis to couple light between said first and second modes; and spacing the intervals such that said coupling is cumulative between only said first and second modes. 16. A fiber interferometer, comprising:an optical fiber having first and second propagation modes, said first and second modes providing first and second optical paths through said fiber; a first modal coupler which couples said optical paths at a first selected location on said fiber; a second modal coupler which couples said optical paths at a second selected location on said fiber, said first location spaced from said second location by a segment of said fiber; and a detector which detects light in one of the optical paths independently of any light in the other of the optical paths to sense changes in said optical paths in said segment of said fiber. 17. A fiber interferometer, as defined by claim 16, wherein said first and second modes comprise spatial modes. 18. A fiber interferometer, as defined by claim 17, wherein said first and second modes are first and second order spatial modes. 19. A fiber optic polarization coupler, comprising:an optical fiber having first and second spatial propagation modes; and a modal coupler which cumulatively couples light between said spatial modes, said modal coupler being adapted to preferentially cumulatively couple light of a first polarization relative to light of a second polarization, such that a first fraction of light of said first polarization is coupled and a second fraction of light of said second polarization is coupled, said first fraction being significantly greater than said second fraction. 20. A modal coupler, comprising:an optical fiber having a longitudinal axis; and a light source for introducing a lightwave into said optical fiber, said lightwave having a wavelength selected such that said fiber supports first and second spatial modes such that said fiber supports first and second spatial modes for said wavelength, said fiber having a beat length for said modes, the longitudinal axis of said fiber being displaced at spaced intervals along said fiber such that portions of said longitudinal axis are shifted relative to other portions of said axis to cause coupling between sid modes, said intervals spaced in accordance with the beat length for only said first and second spatial modes of said fiber such that said coupling at said intervals is cumulative.

1986-07-09

en

1988-09-06

US-26367463-A

Quick detachable hoist J1me 1964 s. PENNEY ETAL QUICK DETACHA'BLE HOIST 2 Sheets-Sheet 1 Filed March 1, 1963 GEORGE PENNEY NORMAN W. WI LSON INVENTORS June 30, 964 G. PENNEY ETAL 3,139,193 QUICK DETACHABLE HOIST Filed March 1, 1965 2 Sheets-Sheet 2 l l l l l l I I I HA" E474 GEORGE PEN NEY NORMAN W. WILSON INVENTOR. BYWM ATTY United States Patent O 2 Claims. (Cl. 21477) This application is a substitute for our application filed August 4, 1961, Serial No. 129,357. The invention herein shown and described relates to new and useful improvements in hoists adapted, though not restrictively so, for use on truck bodies and the like and has for its principle object to provide a hoist of this character which is of simple, efiicient, durable all welded construction and one which may be quickly and conveniently attached to or detached from any sturdy component of the truckstructure such for example asthe rear bumper thereof. Another object of the invention is to provide a hoist of the character described which is operable by a standard hydraulic jack which is readily applicable to the hoist or removable therefrom when desired or necessary. A further object is the provision of a hoist capable of lifting heavy loads with minimum effort on the part of the operator and which may be conveniently manipulated for placing the load in any desired location within or upon the truck body. The foregoing and 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 drawingsforming, a part hereof and in which: FIGURE 1 is a rear elevational view of a truck equipped with a hoist made in accordance with our invention. FIGURE 2 is an elevational view of the hoist on an enlarged scale and rotated through 90 of a circle from the position shown in FIGURE 1. FIGURE 2A is a fragmentary detail view on an enlarged scale of the free end of the hoist boom. FIGURE 3 is a sectional top plan view taken approximately along the line 33 of FIGURE 2 on an enlarged scale. FIGURE 4 is a side elevational view of FIGURE 3. FIGURE 5 is a fragmentary sectional detail view taken approximately along the line 55 of FIGURE 3. FIGURE 6 is a detail view of a jack-anchoring means, and FIGURE 7 is a side elevational view of FIGURE 6. With continuing reference to the drawings wherein like references of character designate like parts and particularly FIGURES 1 and 2 thereof, reference numeral 1 indicates generally a truck body which may be of the pick-up type having a tail gate 2 and a top 3. The truck is provided with a rear bumper 4 of the so called wrap-around type made of channel section bent at a right angle at both of its ends. The tail gate is hinged to the bottom wall of the truck body as at 5 in the conventional manner. The hoist comprises a turret in the form of a circular plate 7 having a concentric sleeve bearing 8 integrated with its underside and extending downwardly through aligned openings 9 and 10 in upper and lower gussets 11 and 12 welded to and interconnecting respectively the top and bottom flanges of one of the rearwardly bent ends 13 of the bumper 4. The top end of the bearing 8 is welded as at 14 to the underside of the gusset 11. The top end of a pivot shaft 15, journalled in the sleeve bearing 8, extends upwardly through a boom pivot plate 16 and into the bottom half of a boom pivot mounting 3,139,198 Patented June 30, 1964 block 17 Whose bottom end is welded as at 18 to the plate 16 near one end thereof and to the shaft 15 as at 19. A clevis 20 is hingedly attached by a pin 21 to the block 17 and integrated at its top end with a boom centering shaft 22 extending upwardly into the bottom end of the boom indicated generally at 25, and which comprises a tubular member 26 shaped as shown in FIGURES 1 and 2 and provided with a reinforcing rib 27 extending substantially throughout its length. The free end of the boom is provided with aring member 28 for the reception of a chain or cable as indicated at 30 in FIGURE 1 or a hook (not shown) could be attached to the member 28 for handling loads indicated generally at 31 in FIGURE 1. The boom pivot plate is reinforced by parallel ribs 16A, and the boom pivot mounting block 17 is reinforced by a gusset 17A. From the foregoing it will be readily apparent that the boom 25 through the medium of the boom pivot plate 16 and pivot shaft 15 can be rotated through 360 of a circle and that the boom itself can be swung in a vertical plane, regardless of the position of the boom pivot plate, from a position as indicated by broken lines in FIGURE 2 where its freeend can be resting upon the bottom wall of the truck body to an elevated position in the proximity of that shown in full lines. Integrated with the boom 25 near the bottom end thereof is a horizontally disposed jack plate 35 reinforced on its underside by a gusset 36 welded to the plate and to the boom as at 37 and 38 respectively. The jack plate 35 is further reinforced by diagonal gussets 39 welded at their bottom end to the jack plate as at 40 and at their top end to the boom as at 41 (see FIG. 2). A standard hydraulic jack indicated generally at 42 and operable by a jack handle (not shown) is held seated on the jack plate 35 by means of cables or chains 43 attached at their bottom end to clevises 45 welded as at 46 to the boom pivot plate 16. The top ends of the chains 43' are attached to eyes 48 welded as at 49 to opposite sides of a jack pad 54)" having a central downwardly opening recess 52 shouldered as at 53 for the reception of a ring 54 welded in place as at 55. The jack 42 may be a standard hydraulic type preferably, though not restrictively, of five-ton capacity having a ram or piston shaft 61) provided with a threadedly adjustable extension 61 adapted for insertion through the ring 54 and into the recess 52. The ram 60, and hence the jack pad 50 is operable from the retracted position shown in broken lines in FIGURE 2 to the full line extended position shown therein. As clearly shown in FIGURES 1-4, the clevises 45 are offset from the boom pivot 21 and also from. the thrust line of the jack ram 60. As a consequence thereof, outward movement of the ram 66 from the retracted position shown in broken lines in FIGURE 2 will exert a pulling force on the chains 43 which will be reacted against by the clevises 45 and transmitted through the jack body 42 and jack plate 35 to the boom 25 above and to one side of the boom pivot 21. The triangle of forces and the magnitude thereof thus applied to the boom with the jack plate acting as a lever arm and the boom pivot as a fulcrum will provide the boom with abundant lifting power for any loads the truck may be capable of carrying. The easy swivel action of the boom pivot plate 16 enables an operator to conveniently spot a load on the truck body after the load has been elevated to clear the bottom wall of the body. Although we have shown and described the turret and its related parts secured to one of the curved ends of a bumper by means of gussets it will be readily understood that the sleeve bearing 8 of the turret could be extended through and secured to the flanges of a bumper made of straight channel section. Also, we do not wish to be limited to a hydraulic jack as herein shown and described since obviously mechanical jacks of the screw type and the like could be used just as effectively. The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1. A hoist of the character described, comprising in combination, a turret, a vertically disposed sleeve bearing mounting said turret to flanges of a vehicle bumper of channel section, a pivot shaft journalled in said sleeve bearing and extending upwardly through said turret, a boom pivot plate secured at one of its ends to said pivot shaft for rotation therewith, a boom of generally arcuate shape in side elevation and having a top end and a bottom end, means hingedly mounting the bottom end of the boom to said boom pivot plate, a jack, means removably supporting said jack on said boom near said bottom end thereof in offset relation thereto and to said hinged boom mounting means, a ram operable by said jack, non-elastic means interconnecting said ram and the opposite end of said boom pivot plate at a point more remote from said jack support whereby the triangle of forces applied to the boom through the lever arm characteristic of said offset jack supporting means will impart upward swinging movement of the boom relative to said bumper and whereby a load suspended from said top end of the boom may be lowered onto or lifted from the body of a vehicle to which said bumper is secured. 2. A combination hoist and vehicle bumper, said bumper being of channel section and bent at a right angle at least at one of its ends, upper and lower gussets secured to and interconnecting respectively the top and bottom flanges of said bent end of the bumper, wardly through the aligned openings in said circular and boom pivot plates and secured to the latter, a vertical disposed boom pivot mounting block secured at its bottom end to said extended top end of said pivot shaft and to said boom pivot plate, a boom of generally arcuate shape in side elevation and having a top end and a bottom end, means hingedly mounting the bottom end of the boom to said boom pivot mounting block, a plate secured to said boom superjacent said bottom end thereof and extending outwardly at a right angle therefrom, a vertically disposed jack supported upon said plate, a ram operable by the jack, a jack pad straddling said ram and extending outwardly from both sides thereof, non-elastic means interconnecting said jack pad and said boom pivot plate, and the connection of said non-elastic means with said boom pivot plate being offset from said boom pivot mounting block and from the vertical axis of said jack and ram, whereby the triangle of forces applied to the boom through the lever arm characteristic of said jack supporting plate will impart upward swinging movement of the a boom relative to said bumper and whereby a load suspended from said top end of the boom may be lowered onto or lifted from the body of a vehicle to which said bumper is secured. References Cited in the file of this patent V UNITED STATES PATENTS 1. A HOIST OF THE CHARACTER DESCRIBED, COMPRISING IN COMBINATION, A TURRET, A VERTICALLY DISPOSED SLEEVE BEARING MOUNTING SAID TURRET TO FLANGES OF A VEHICLE BUMPER OF CHANNEL SECTION, A PIVOT SHAFT JOURNALLED IN SAID SLEEVE BEARING AND EXTENDING UPWARDLY THROUGH SAID TURRET, A BOOM PIVOT PLATE SECURED AT ONE OF ITS ENDS TO SAID PIVOT SHAFT FOR ROTATION THEREWITH, A BOOM OF GENERALLY ARCUATE SHAPE IN SIDE ELEVATION AND HAVING A TOP END AND A BOTTOM END, MEANS HINGEDLY MOUNTING THE BOTTOM END OF THE BOOM TO SAID BOOM PIVOT PLATE, A JACK, MEANS REMOVABLY SUPPORTING SAID JACK ON SAID BOOM NEAR SAID BOTTOM END THEREOF IN OFFSET RELATION THERETO AND TO SAID HINGED BOOM MOUNTING MEANS, A RAM OPERABLE BY SAID JACK,

1963-03-01

en

1964-06-30

US-34360389-A

Shunt connection device for electrical connectors ABSTRACT An electrical connector comprises a first casing member in which is a series of housings each adapted to receive a respective one of a plurality of male contact members each incorporating a tang. The connector further comprises a second casing member complementary to the first casing member in which are a series of housings each adapted to receive a respective female contact member each adapted to cooperate with the tang on a respective male contact member to make an electrical connection. The connector further comprises a plurality of connection channels each adapted to have a tang passed through it and a shunt module adapted to receive these electrical connection channels. The shunt module comprises an insulative material body and a series of passages adapted to coincide with respective housings of the first casing member and to receive a respective electrical connection channel. A skirt on one casing member is adapted to receive the shunt module. At least two of the electrical connection channels in the shunt module are electrically interconnected to make a shunt connection. BACKGROUND OF THE INVENTION 1. Field of the invention The present invention concerns electrical connectors comprising a first casing member with male contact members and a second casing member with female contact members, the two casing members being adapted to fit together so that the male members cooperate with the female members to provide electrical continuity. 2. Description of the prior art Connectors of this kind are used in many industries and in particular in the automobile industry, and they are generally fitted to the ends of previously prepared electrical conductor harnesses. In harnesses of this kind, other conductors are "spliced" to certain conductors to constitute branch connections providing other electrical functions. The "splicing" of these additional conductors constitutes a task which is very difficult to achieve from the mechanical point of view. One object of the present invention is to eliminate such splicing. SUMMARY OF THE INVENTION The present invention consists of, in an electrical connector comprising a first casing member, a plurality of male contact members each incorporating a tang, a series of housings in the first casing member each adapted to receive a respective male contact member, a second casing member complementary to the first casing member, a plurality of female contact members adapted to cooperate with the tang on a respective male contact member to make an electrical connection and a series of housings in the second casing member each adapted to receive a respective female contact member, a shunt connection device comprising a plurality of electrical connection channels each adapted to have a tang pass through it and a shunt module adapted to receive the electrical connection channels and comprising an insulative material body and a series of passages adapted to coincide with respective housings of the first casing member and to receive a respective electrical connection channel, in which shunt module at least two of the electrical connection channels are electrically interconnected to provide a shunt connection, the connector further comprising a skirt on one casing member adapted to receive said shunt module. In this way it is a simple matter to connect electrically at least two male contact member tangs, one being linked to a female contact member whereas the other may be free. In this way splicing is entirely eliminated and the wiring can be done entirely automatically by machine. The electrical connection channels are preferably made from a strip of highly conductive metal which is cut to form a series of H-shaped holes delimiting two tangs which are bent towards one side of the strip to form the channels, the marginal bands at either side of the channels serving to interconnect the channels electrically and being adapted to be cut selectively according to the shunt connections required. Two opposite portions of the interior of the skirt preferably comprise abutment members and the shunt module preferably comprises resilient lugs adapted to cooperate with the abutment members to lock the shunt module into the skirt. In a preferred embodiment of the invention the first and second casing members each comprise two superposed series of housings, the shunt module comprises two superposed series of passages and the electrical connection channels adapted to be received into the passages of one series are aligned and interconnected by a respective marginal band and the connector further comprises an intermediate band by which the marginal bands are electrically interconnected. The electrical connection channels are preferably made from a strip of highly conductive metal which is cut to form two series of H-shaped holes, a band between the holes and elongate openings in a middle portion of the band and the tangs delimited by the H-shaped holes is bent to form two series of electrical connection channels and the strip is bent into an U-shape so that the electrical connection channels are in opposed relationship in two parallel planes and the marginal bands between each series of electrical connection channels and the corresponding edge of the strip are bent under the electrical connection channels. Each passage preferably comprises a resilient lug for retaining the respective electrical connection channel. Finally, at least one of the casing members could be of a type comprising a compartment adapted to receive an insert comprising the series of housings each adapted to receive a contact member. The invention will now be described in more detail and by way of example only with reference to a specific embodiment shown in the appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view in perspective of a connector fitted with a shunt device in accordance with the invention. FIG. 2 is a plan view of a cut strip adapted to form the conductor of the shunt device in accordance with the invention after cutting but before bending. FIG. 3 is a plan view showing various possibilities for cutting the strip. FIG. 4 shows the strip finally obtained. FIG. 5 is a view in elevation from the front of the shunt module adapted to receive the strip from FIGS. 2 through 4. FIG. 6 is a view in elevation of the back of the shunt module from FIG. 5. FIG. 7 is a view in cross-section on the line 7--7 in FIG. 5. FIG. 8 is a view in cross-section on the line 8--8 in FIG. 5. FIG. 9 is a view in cross-section on the line 9--9 in FIG. 5. FIG. 10 is a view of the female casing partly in cross-section. FIG. 11 is a view of the assembled casing in axial cross-section. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is an exploded perspective view of an electrical connector fitted with a shunt device in accordance with the invention and comprising a female casing 1, a complementary male casing 2, two inserts 3 adapted to be received in a compartment 7 of the female casing 1 and two inserts 4 adapted to be received in a compartment 8 of the male casing 2. To make FIG. 1 clearer only one of each of the inserts 3 and 4 has been shown. Each insert 3 is divided into a series of housings 10, with each adapted to receive a male contact member 12 incorporating a bar 13, lugs 15 for crimping onto the conductive core of a previously stripped electrical conductor and lugs 16 for crimping onto the insulation of the conductor, a hole 14 being also provided in said male contact member 12. Each insert 4 is divided into a number of housings 21, with each corresponding to one of the housings 10 and each adapted to receive a female contact member 20. The female contact member 20 comprises lugs 25 for crimping onto the core of a stripped electrical conductor, lugs 26 for crimping onto the conductor and an extension 22 folded into a clamp 23 for gripping the bar 13 elastically. The female contact member 20 could be of some other type, for example with a U-shaped housing, the free ends of the branches being inwardly folded and adapted with the core of the U to grip the bar 13. Similarly, the bars 13 could be cylindrical and the female contacts have a corresponding shape. A shunt module 5 is housed in a skirt 28 of the female casing 1. The shunt module 5 is shown in detail in FIGS. 2 through 8 and comprises an insulative suppport 55 and a connecting strip 30. The connecting strip 30 (see FIGS. 2, 3 and 4) is made from a generally rectangular blank which is a good conductor of electricity with two longer sides 32 and 33 and two shorter sides 34 and 35. Into the middle part are cut elongate holes 36 and symmetrically relative to the latter H-shaped holes 37 which delimit two tangs 38 and 39. As seen in FIG. 3, each tang 38 is bent towards one side of the blank and each tang 39 is bent to the same side and towards the tang 38 of the adjacent H-shaped hole so as to form an electrical connection channel 40. The blank is then folded into a U-shape along two lines 41 and 42 passing through the edge of the holes 37 adjacent the holes 36 so that the electrical connection channels 40 lie on two parallel lines perpendicular to a core 48. The marginal band 46 situated between the edge of the holes 37 and the longer side 32 is bent along a line 44 so as to lie under one of the rows of electrical connection channels 40. The marginal band 47 situated between the edge of the holes 37 and the long side 33 is bent along a line 45 to extend under the second row of channels 40. Areas 50 may be cut selectively during manufacture of the connecting strip 30. Areas 51 may be cut selectively after the connecting strip 30 has been fitted into the shunt module 5. The shunt module 5 comprises an insulative material body 55 shaped to define a series of passages 56 each adapted to receive an electrical connecting channel 40 of one row on the connecting strip 30. The body 55 comprises a second series of passages 57 adapted to receive the electrical connection channels 40 of the second row. The central part of the body 55 comprises between a passage 56 and the corresponding passage 57 a box-section 59 against which the core 48 bears. Large holes 60 are provided between the box-sections 59. The passages 56 are interconnected by box-sections 62, 63 and 64 and the passages 57 are interconnected by box-sections 65, 66 and 67. Between the box-sections 62, 63 and 64 and the box-sections 59 is a groove 69 in which the marginal band 47 is housed, a similar groove 70 being provided between the box-sections 65, 66 and 67 and the box-sections 59 for the marginal band 46. Each passage 56 comprises an elastic lug 72 ending in a hook 73. Each passage 57 is likewise provided with an elastic lug 74 ending with a hook 75. Thus when the connecting strip 30 is fitted the lugs 72 and 74 move apart elastically to enable the electrical connecting channels 40 to be inserted into the passages 56 and 57 and when the channels are in place the hooks 73 and 75 cooperate with the corresponding ends of the channels to lock the connecting strip into the module. The body 55 comprises two locking tabs 80 and 81 (see FIG. 9). On the side opposite the hook 73 the passages 56 comprise a slot 82 for the tangs 13 to pass through. The passages 57 comprise slots 84 corresponding to the slots 82. The body 55 comprises notches 85 near one end and adapted to cooperate with projections 86 on the skirt 28 so that the shunt module can only be fitted one way round. As seen in FIG. 10, the skirt 28 of the casing 1 comprises on one side a shoulder 90 and on the opposite side a ramp 91 with a shoulder 92. To install the shunt module 5 it is inserted into the skirt 28. The elastic lug 81 bears against the shoulder 90 so as to be retracted and to lock against the latter. The lug 80 bears against the ramp 91 so as to be retracted elastically until its free end bears against the shoulder 92. The insert 3 is provided with a shoulder 95 and abutment members 96. The shoulder 95 is adapted to bear against a corresponding shoulder 97 of the compartment 7 to limit its insertion. The abutment members 96 cooperate with a shoulder 98 to oppose withdrawal of the insert once fitted. Each housing 10 is provided with a spring tang 99 with a peg 100 adapted to cooperate with the hole 14 so that once it is inserted into the housing the male contact member 12 is locked in place. The bar 13 of each member 12 passes through a channel 40 and is consequently electrically connected to the connecting strip 30. At the end opposite that comprising the compartments 8, the male casing 2 is closed by a partition wall 110 pierced by slots 111 for the bars 13 to pass through. The insert 4 comprising a shoulder 103 adapted to bear against a shoulder 104 of the housing 8 to limit the insertion and abutment members 102 adapted to cooperate with the back of the slots 112 in the casing 2 to block the inserts and oppose their withdrawal. Each housing 21 of an insert 4 comprises an elastic lug 105 provided with a pin 106 which by cooperating with the hole 24 locks the female contact member 20 in place. It will be readily understood that before fitting the connecting strip 30 selected areas 50 are cut, according to the shunt connections to be made, and that when the strip is fitted the corresponding areas 51 are cut so that two channels 40, or three channels 40, or four channels 40, etc. . . . are electrically interconnected. According to the electrical connections to be made some housings 21 of the inserts 4 may not have any members 20 while the male tangs 13 of the corresponding housings 10 may be electrically connected by the shunt device in accordance with the invention. The invention greatly facilitates the making of shunt connections in wiring systems and makes it possible to dispense with the splicing of conductors. Of course, the invention is not limited to the embodiment that has just been described and shown. Numerous modifications of detail may be made thereto without thereby departing from the scope of the invention. There is claimed: 1. A shunt connection device for an electrical connector, said electrical connector comprising a first casing member, a plurality of male contact members each incorporating a tang, a series of housings in said first casing member each adapted to receive a respective male contact member, a second casing member complementary to said first casing member, a plurality of female contact members each adapted to cooperate with a tang on a respective male contact member to make an electrical connection and a series of housings in said second casing member each adapted to receive a respective female contact member; said shunt connection device comprising a plurality of electrical connection channels each adapted to have a tang pass through it and a shunt module adapted to receive said electrical connection channels and comprising an insulative material body and a series of passages adapted to coincide with the respective housings of said first casing member and to receive a respective electrical connection channel, in which shunt module at least two of said electrical connection channels are electrically interconnected to provide a shunt connection, the connector further comprising a skirt on one casing member adapted to receive said shunt module. 2. Device according to claim 1 wherein two opposite portions of the interior of said skirt comprise abutment members and said shunt module comprises resilient lugs adapted to cooperate with said abutment members to lock said shunt module into said skirt. 3. Device according to claim 1 wherein said electrical connection channels are made from a strip of highly conductive metal which is cut to form a series of H-shaped holes delimiting two tangs which are bent towards one side of said strip to form said channels, with marginal bands to either side of said channels, serving to interconnect said channels electrically and being adapted to be cut selectively according to shunt connections required. 4. Device according to claim 3 wherein said first and second casing members each comprise two superposed series of housings, said shunt module comprises two superposed series of passages and said electrical connection channels adapted to be received into the passages of one series are aligned and interconnected by a respective marginal band and further comprising an intermediate band by which said marginal bands are electrically interconnected. 5. Device according to claim 4 wherein said electrical connection channels are made from a strip of highly conductive metal which is cut to form two series of H-shaped holes, a band between said holes and elongate openings in a middle portion of said band and said tangs delimited by said H-shaped holes are bent to form two series of electrical connection channels and said strip is bent into a U-shape so that said electrical connection channels are in opposed relationship in two parallel planes and the marginal bands between each series of electrical connection channels and the corresponding edge of the strip are bent under said electrical connection channels. 6. Device according to claim 4 wherein each passage comprises a resilient lug for retaining the respective electrical connection channel. 7. Device according to claim 4 wherein at least one of said casing members is of a type comprising a compartment adapted to receive an insert comprising the series of housings each adapted to receive a contact member. 8. An electrical connector comprising a first casing member, a plurality of male contact members each incorporating a tang, a series of housings in said first casing member each adapted to receive a respective male contact member, a second casing member complementary to said first casing member, a plurality of female contact members each adapted to cooperate with a tang on a respective male contact member to make an electrical connection, a series of housings in said second casing member each adapted to receive a respective female contact member, a shunt connection device comprising a plurality of electrical connection channels each adapted to have a tang pass through it and a shunt module adapted to receive said electrical connection channels and comprising an insulative material body and a series of passages adapted to coincide with the respective housings of said first casing member and to receive a respective electrical connection channel, in which shunt module at least two of said electrical connection channels are electrically interconnected to provide a shunt connection, and a skirt on one casing member adapted to receive said shunt module. 9. Connector according to claim 8 wherein two opposite portions of the interior of said skirt comprise abutment members and said shunt module comprises resilient lugs adapted to cooperate with said abutment members to lock said shunt module into said skirt. 10. Connector according to claim 8 wherein said electrical connection channels are made from a strip of highly conductive metal which is cut to form a series of H-shaped holes delimiting two tangs which are bent towards one side of said strip to form said channels, with marginal bands to either side of said channels, serving to interconnect said channels electrically and being adapted to be cut selectively according to shunt connections required. 11. Connector according to claim 10 wherein said first and second casing members each comprise two superposed series of housings, said shunt module comprises two superposed series of passages and said electrical connection channels adapted to be received into the passages of one series are aligned and interconnected by a respective marginal band and further comprising an intermediate band by which said marginal bands are electrically interconnected. 12. Connector according to claim 11 wherein said electrical connection channels are made from a strip of highly conductive metal which is cut to form two series of H-shaped holes, a band between said holes and elongate openings in a middle portion of said band and said tangs delimited by said H-shaped holes are bent to form two series of electrical connection channels and said strip is bent into a U-shape so that said electrical connection channels are in opposed relationship in two parallel planes and the marginal bands between each series of electrical connection channels and the corresponding edge of the strip are bent under said electrical connection channels. 13. Connector according to claim 11 wherein each passage comprises a resilient lug for retaining the respective electrical connection channel. 14. Connector according to claim 11 wherein at least one of said casing members is of a type comprising a compartment adapted to receive an insert comprising the series of housings each adapted to receive a contact member.

1989-04-27

en

1990-09-04

US-78125792-A

Preparation of azo pigments with low pcb content by coupling in the presence of olefins ABSTRACT The production which is customary in practice of monoazo compounds based on dichloro- and trichloroanilines or disazo compounds of the chlorinated biphenyl series by conventional coupling methods meets with difficulties in that the resulting pigments are contaminated by traces of polychlorinated biphenyls. According to the invention, it has now been found that by addition of water-soluble olefins of the type ##STR1## (R =H, alk or Oalk; X =--COOR 1 , --CONHR 2 or --NR 3 COR 4 ) in the azo coupling, the side reactions which form PCBs can be decidedly suppressed during synthesis of the pigments. The invention relates to the preparation of azo pigments based on chlorinated benzene-diazonium salts or biphenyl-bis-diazonium salts and acidic CH coupling components. Industrially produced organic pigments may contain polychlorinated biphenyls (PCBs) as an impurity if certain structural conditions exist in the starting components and because of side reactions, depending on the type of synthesis process chosen [compare R. Anliker, Swiss Chem 3 (1981), No. 1-2, pages 17-23 (German) or pages 25-29 (English); and W. Herbst and K. Hunger in "Industrielle Organische Pigmente (Industrial Organic Pigments)", VCH-Verlag, Weinheim 1987, pages 577-578]. The persistence and bioaccumulative properties of relatively highly chlorinated biphenyls (containing three or more chlorine atoms) above all have meant that production of this class of compounds, which was previously widely used industrially, has been stopped and marketing of compounds and formulations which contain PCBs as impurities has even been subjected to restrictions and controls. The corresponding legal regulations have become increasingly stricter in recent years and the threshold values of amounts of polychlorinated biphenyls permitted in commercial products have been drastically reduced (in the USA, for example, to not more than 25 μg of PCB per gram of the substance marketed). It has been found, however, that amongst the azo pigments, chiefly monoazo compounds based on di- and trichloroanilines, and also disazo pigments of the chlorinated biphenyl series may be obtained having an undesirable contamination with polychlorinated biphenyls if the pigments are prepared by conventional large-scale industrial coupling processes. The PCB contents in these azo pigments in these cases often exceed the tolerance specified in the USA. It was thus initially obvious for the PCBs to be removed by solvent extraction from the coloring agents contaminated with them. European Patent EP-B-0,063,321 thus explains, for example, that crude organic pigments of varying chemical category can be converted into products of high purity by treatment with a mixture of a hydrophilic and a hydrophobic organic solvent at 50°-180° C., these solvents being of only limited miscibility with one another. In this technique, the impurities then collect in one of the organic phases and can be removed by the route mentioned. However, the amounts of PCBs present are often only incompletely affected by these and similar purification methods, since pigments of high specific surface area, that is to say with a high content of extremely fine particles, usually primarily bond impurities securely to their active surface by adsorption and moreover also securely hold them occlusively in agglomerates. Solvent treatment of a pigment is furthermore almost always associated with a change in the coloristic properties, so that there are narrow tolerances on the duration and intensity of an intended purification procedure. In the case of pigments of low solvent stability, purification analogously to the processes described above therefore cannot be used at all. Another factor which makes things difficult is the fact that in all purification operations using organic solvents the impurities enriched therein, i.e., for example the polychlorinated biphenyls, must be eliminated again and subsequently destroyed, which raises considerable technical problems, particularly in the case of PCBs: Because of the exceptional resistance of the class of compounds to be removed, degradation thereof by chemical methods, thermal methods, photolysis and the like is extremely difficult [Review Article by D. Martinetz in Chem. Techn. 39 (1987)/Volume 11, pages 466-470]. The severity of these degradation methods as a rule also does not allow PCB impurities in pigments to be destroyed, if appropriate, without at the same time damaging the coloring agent. For the reasons mentioned, it was in all cases desirable to develop synthesis processes for pigments which exclude or at least largely suppress the formation of traces of PCBs as by-products of the coupling reaction from the beginning. Thus, according to published European Patent Application EP-A-0,319,452, specific coupling conditions were to be discovered for producing monoazo pigments starting from di- and trichloroanilines as diazo components, these conditions leading to a reduction of the PCB content in the corresponding pigments to values of not more than 25 μg/g. However, the prior art known from this patent application relates exclusively to process variants in which the azo coupling is carried out in a pH range of less than 7 by addition of the diazonium salt solution to a suspension or solution of the coupling component, or by simultaneous metering of the aqueous suspensions or solutions of the two reaction components (pigment formation components) into a reaction vessel. As a characterizing feature, the procedure described therein furthermore requires limited molar excesses of diazonium salt, based on the sum of the number of moles of the coupling component present in the reaction mixture and of pigment already formed, the permitted excess of diazonium salt being made dependent on the pH range of the coupling reaction. Thus, for example, in the pH range of 4 to 7 preferred for azo couplings for the preparation of pigments, a diazonium salt excess of less than 0.05 mol % has been defined in order to obtain products with PCB contents of not more than 25 μg/g. In contrast, if the synthesis of monoazo pigments of the di- or trichloroaniline series is carried out by a method in which the coupling component is fed into a solution of the diazonium salt which has been initially introduced into the reaction vessel (so-called "indirect" coupling), the pigment obtained can contain polychlorinated biphenyls to a degree which far exceeds the legally prescribed limit of 25 μg of PCBs per g of pigment. However, azo pigments which are prepared by a process according to which alkali is metered into the reaction mixture continuously or discontinuously in the course of the coupling operation in order to maintain a certain pH range (so-called "pendulum coupling") often contain--under certain structural conditions--PCB contents which are significantly above 25 μg/g. It was therefore particularly desirable to have available an improved process for azo coupling in which the process limitations described above can be dispensed with and pigments having a particularly low content of PCB impurities are obtained. The present invention thus relates to a process for the preparation of monoazo pigments of the general formula I ##STR2## or of disazo pigments of the general formula II ##STR3## in which n is 1, 2 or 3, m is 1 or 2, K1 and K2 are each the radical of an acidic CH coupling component H--K1 or H--K2 from the acetoacetic acid arylamide or naphthol series or of a heterocyclic structure and K1 and K2 are identical or different, which contain not more than 25 μg of polychlorinated biphenyls having at least 4 chlorine atoms (PCBs) per gram of pigment, by azo coupling in an aqueous medium, which comprises carrying out the coupling reaction in the presence of olefins of limited or unlimited water-solubility of the general formula III in which R is a hydrogen atom or an alkyl or alkoxy group and X is a radical of the formula --COOR1, --CONHR2 or --NR3 COR4 or--if R is not alkoxy--is also the radical --CN, in which R1 is hydrogen, alkyl or alkyl which is substituted by 1 or more radicals from the group comprising hydroxyl, alkoxy, amino, alkylamino and dialkylamino, R2 is hydrogen, alkyl or alkyl which is substituted by 1 or more radicals from the group comprising hydroxyl, alkoxy, amino, alkylamino, dialkylamino, sulfo, carboxyl, alkoxycarbonyl and saturated or unsaturated alkanoylamino as well as corresponding N-alkanoyl-N-alkyl-amino, R3 is hydrogen or alkyl and R4 is alkyl. Olefins of the formula III which are preferably employed in the context of the pigment synthesis described are those in which R is hydrogen, C1 C4 -alkyl or C1 -C4 -alkoxy; in particular hydrogen, methyl, methoxy or ethoxy, and the radical X has the meaning shown for this by the abovementioned groupings, in which case R1 is hydrogen or C1 -C4 -alkyl which can be substituted by 1 or 2 radicals from the group comprising hydroxyl, C1 -C4 -alkoxy, amino, N-(C1 -C4 -alkyl)-amino and N,N-di-(C1 -C4 -alkyl)-amino; in particular hydrogen, methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-aminoethy, 2-(dimethylamino)-ethyl, 3-aminopropyl or 3-(dimethylamino)propyl, R2 is hydrogen or C1 -C4 alkyl which can be substituted by 1 to 3 radicals from the group comprising hydroxyl, C1 -C4 -alkoxy, amino, N-(C1 -C4 -alkyl)-amino, N,N-di-(C1 -C4 -alkyl)-amino, sulfo, carboxyl, (CC1 -C4 -alkoxy)carbonyl, N-(C2 -C5 alkanoyl)-amino and N-(C3 -C5 alkenoyl)-amino; in particular hydrogen, C1 -C4 -alkyl or C1 -C4 -alkyl which is substituted by 1 or 2 radicals from the group comprising hydroxyl, methoxy, ethoxy, amino, methylamino, ethylamino, N,N-dimethylamino, N,N-diethylamino, sulfo, carboxyl, acetamido and acrylamido, R3 is hydrogen or C1 -C4 -alkyl, in particular hydrogen, methyl or ethyl, and R4 is C1 -C4 -alkyl, in particular methyl or ethyl. Olefinic compounds of the formula III which are particularly suitable for the process claimed are those in which the radical X is the grouping --CONHR2 and R and R2 have the abovementioned meanings. The olefins to be added to the coupling mixture are readily polymerizable compounds. The water-solubility thereof should preferably be at least 1%. Such olefins of the type of compound listed which dissolve completely in water at the stated concentrations are preferred. Examples of these are, inter alia: acrylic acid, 2-methyl-propenoic acid (methacrylic acid), methyl acrylate, ethyl 2-ethoxy-acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-dimethylaminoethyl methacrylate, acrylamide, N-methylacrylamide, 2-methylpropenamide (methacrylamide), N-acetylacrylamide, N-hydroxymethyl-acrylamide, 2-acrylamido-glycolicacid,2-acrylamido-2-methylpropanesulfonic acid, (3-dimethylaminopropyl)-methacrylamide, (2-dimethylaminoethyl)-methacrylamide, (3-diethylamino-propyl)-acrylamide, N-(1-methoxymethyl-propyl)-acrylamide, 2,2-bisacrylamidoacetic acid, vinyl-acetamide, N-methyl-N-vinyl-acetamide, acrylonitrile and methacrylonitrile. From the list of abovementioned compounds, acrylamide and methacrylamide and derivatives thereof are preferably used. The olefins of the structure III are known per se and/or can be prepared by known or customary methods. The particular amounts of the olefins to be employed according to the invention vary between 0.01 and 1% by weight, preferably 0.05 and 0.5% by weight, based on the aqueous pigment suspension obtained after the azo coupling, or between 0.1 and 10% by weight, preferably 0.5 and 5% by weight, based on the amount of pigment formed in the reaction. All the customary variants of azo couplings in an aqueous medium can be practised in the process according to the invention for the preparation of low-PCB mono- or disazo pigments. It is irrelevant here whether the diazonium salt solution is added to the solution or suspension of the particular coupling component in the course of the coupling or whether, for example, an alkaline solution of the coupling component is allowed to run into the diazonium salt solution or suspension; the coupling can also be carried out by simultaneously bringing together the solutions or suspensions of the two reaction partners in one reaction vessel, it being possible for static or dynamic mixers to be used in each case. The azo coupling is preferably carried out under the action of a buffer mixture, advantageously at a pH in the range from 4 to 7; however, the most favorable pH conditions for the course of the coupling reaction can also be established and maintained by metering in acid or alkali. If appropriate, the coupling can take place in the presence of nonionic, anionic or cationic surface-active compounds or other types of auxiliary, such as naturally occurring or synthetic resins or resin derivatives or additives for printing inks, lacquers or plastics. The aqueous pigment suspensions obtained in the coupling operation are as a rule filtered immediately after synthesis and the pigments are washed free from salt. The resulting aqueous press-cake is then either used directly for pigmenting or first processed to give a powder after drying. The process according to the invention is particularly suitable for lowering the PCB content of those monoazo pigments which are produced by coupling processes practised on a large industrial scale using chlorinated anilines as diazo components. Examples of such possible diazo components are: 2-chloroaniline, 3-chloroaniline, 4-chloroaniline, 2,3-dichloroaniline, 2,4-dichloroaniline, 2,5-dichloroaniline, 2,6-dichloroaniline, 3,4-dichloroaniline, 3,5-dichloroaniline,2,3,4-trichloroaniline,2,3,5-trichloroaniline, 2,3,6-trichloroaniline, 2,4,5-trichloroaniline, 2,4,6-trichloroaniline and 3,4,5-trichloroaniline, 2,4-dichloroaniline, 2,5-dichloroaniline and 2,4,5-trichloroaniline being preferred diazo components. The process according to the invention is furthermore suitable for the preparation of low-PCB disazo pigments starting from chlorinated diaminobiphenyls. Examples which may be mentioned of these bifunctional diazo components are: 2,2'-dichloro-4,4'-diamino-biphenyl, 3,3'-dichloro-4,4'- diamino-biphenyl, 2,2',3,3'-tetrachloro-4,4'-diaminobiphenyl,2,2',5,5'-tetrachloro-4,4'-diamino-biphenyl and 2,2',6,6'-tetrachloro-4,4'-diamino-biphenyl, 3,3'-di-chloro-4,4'-diamino-biphenyl and 2,2',5,5'-tetrachloro-4,4'-diamino-biphenyl being preferred bis-diazo components. Acidic CH coupling components which are of particular interest for the synthesis of mono- or disazo pigments by the process according to the invention are acetoacetic acid arylamides, such as, for example, acetoacetic acid anilide, which can be substituted on the phenyl ring by one or more, preferably 1 to 3, of the radicals from the group comprising methyl, methoxy, ethoxy, nitro and chlorine and/or can contain a fused-on 5- or 6-membered heterocyclic radical on the phenyl ring, preferably benzimidazolone; as well as naphthol or naphthol derivatives, such as 2-hydroxy-3-naphthoic acid and 2-hydroxy-3-naphthoic acid N-arylamides, for example 2-hydroxy-3-naphthoic acid N-phenyl-amide, which can be substituted on the phenyl ring by one or more of the radicals from the group comprising methyl, methoxy, ethoxy, nitro, alkanoylamino, such as acetamino, aroylamino, such as benzoylamino, and chlorine and/or can contain a fused-on 5- or 6-membered heterocyclic radical on the phenyl ring, preferably benzimidazolone; and furthermore all acidic CH com-pounds in which the activated hydrogen atom is bonded to a mono- or polynuclear heterocyclic radical, such as, for example, 1-aryl-pyrazol-5-one, which can be substituted in the 3-position by methyl, carbalkoxy or acylamino, or such as barbituric acid, 2,6-dihydroxypyridine, 2,4-di-hydroxyquinoline, 1,5-diazabicyclo[3,3,0]-octane-2,4,6,8-tetrone, 2H-pyrazolo[3,4-b]pyridine-3,6-dione, 1,2,3,5-tetrahydro-imidazo[1,2-b]isoquinolin-5-one, 9H-pyrazolo[5,1-b]quinazolin-9-one or 2,4-dihydroxy-pyrimido[1,2a]-benzimidazole, to name only a few representatives from the series of heterocyclic coupling components. Examples of selected coupling components for the synthesis of monoazo pigments by the process according to the invention are: 2-hydroxy-3-naphthoic acid N-arylamides, such as 2- hydroxy-3-naphthoic acid anilide, 2-hydroxy-3-naphthoic acid N-(2- or 4-methylphenyl)-amide, 2-hydroxy-3-naphthoic acid N-(2-methoxy- or 2-ethoxyphenyl)-amide, 2-hydroxy-3-naphthoic acid N-(2,5-dimethoxyphenyl)-amide and 5-(2-hydroxy-3-naphthoylamino)-benzimidazol-2-one. Coupling components which are preferably used in the synthesis of disazo pigments are: acetoacetanilides, which can be substituted on the phenyl nucleus by 1 to 3 of the radicals from the group comprising methyl, methoxy, ethoxy, nitro and chlorine, as well as 5-aceto-acetylbenzimidazolones. The azo pigments prepared by the process according to the invention can be used for coloring naturally occurring and synthetic materials. They are particularly suitable for pigmenting printing inks for letterpress/offset printing, gravure printing, flexographic printing and other specific printing processes, for the preparation of pigmented lacquers based on systems which dry by oxidation or oven-drying systems, for the preparation of emulsion paints, for pigmenting plastics, such as, for example, polyvinyl chloride, polyolefins, polystyrenes and copolymers thereof, poly(methyl methacrylates), polyurethanes, polycarbonates, polyesters, cellulose derivatives, elastomers or thermosets, and as coloring agents for spin-dyeing. The pigments obtainable according to the invention can also be employed for specific fields of application, for example as coloring agents for electrophotographic toners, for color jet printing processes (for example ink jet processes) or for heat transfer tapes. In the following examples parts and percentage data relate to the weight, unless indicated otherwise. Parts by volume bear the same relationship to parts by weight as the liter to the kilogram. EXAMPLE 1 16.3 parts of 2,5-dichloroaniline are stirred in 37 parts by volume of 30% strength hydrochloric acid for about 8 hours until formation of the amine hydrochloride is complete. After cooling, by addition of ice, the amine is then diazotized at -5° to 0° C. by feeding in 14 parts by volume of a 40% strength aqueous sodium nitrite solution. After stirring for a further hour, the mixture is diluted to 400 parts by volume by making up with water, the nitrite excess present is destroyed by means of sulfamic acid, kieselguhr is added as a filtration auxiliary and the resulting diazonium salt solution is filtered. 1.2 parts of acrylamide are now introduced into this solution and the diazo component thus prepared is buffered to a pH of 4 to 4.5 with a buffer mixture prepared from 45 parts of 33% strength sodium hydroxide solution and 35 parts of glacial acetic acid. 32.5 parts of 5-(2-hydroxy-3-naphthoylamino)-benzimidaz-ol-2-one are stirred into 300 parts by volume of water and dissolved by addition of 30 parts of 33% strength sodium hydroxide solution at 30°-35° C. in a second vessel. The coupling component solution obtained in the above manner is now added dropwise to the initially prepared buffered diazonium salt solution at 0°-10° C. in the course of one hour, while stirring, the pH of the reaction mixture gradually rising to 5 to 5.5. When the feeding-in of the coupling component has ended and as soon as diazonium ions are no longer detectable by spot tests with H-acid, the suspension is briefly heated to 95° C. and the azo pigment which has precipitated is then filtered off, washed salt-free with water and dried at 60° C. For analytical determination of the content of polychlorinated biphenyls, a powder sample of the coupling product thus obtained, C.I. Pigment Brown 25 - No. 12510 (CAS No. 6992-11-6), is first doped with a standard solution of two known chlorinated biphenyls and dissolved in approximately 96% strength sulfuric acid, and the resulting solution is mixed, in the combined extraction/purification process described below, with silica gel in an amount such that this still remains free-flowing. This mixture (of adsorbent together with test substance) is now transferred into a customary chromatography tube which has already been charged beforehand with two silica gel purification zones (a silica gel layer laden with KOH over a silica gel layer laden with oleum) and is subsequently eluted with n-hexane. The polychlorinated biphenyls in the eluate are determined quantitatively, after separation by gas chromatography on a capillary column, by electron capture detection (=ECD) or massselective detection against an internal PCB standard. The proportions of PCBs determined in this way were 20 μg per g of pigment (20 ppm of PCBs). The sample can also be quantified by other analytical methods, for example by high pressure liquid chromatography (HPLC). EXAMPLE 2 16.3 parts of 2,5-dichloroaniline are diazotized as described in Example 1. After filtration, 4 parts of an approximately 50% strength aqueous solution of methylolacrylamide (N-hydroxymethyl-acrylamide) are added and the hydrochloric acid diazonium salt solution prepared is buffered at pH =4. Coupling is again carried out by feeding an alkaline solution of 32.5 parts of 5-(2-hydroxy-3-naphthoylamino)-benzimidazol-2-one at 0°-8° C. into the diazo component initially prepared and has ended when a pH range of not more than 5.0 to 5.2 is reached in the reaction mixture. The coloring agent obtained after working up and drying, C.I. Pigment Brown 25 (No. 12510) has an analytically determined PCB content of 25 μg/g (25 ppm). EXAMPLE 3 Comparison Test If the process described in Example 1 is carried out by indirect coupling but without using an olefin having the structure according to formula III, the coupling product isolated in this manner, Pigment Brown 25 (No. 12510), then contains about 150 μg/g of polychlorinated biphenyls (150 ppm of PCBs). EXAMPLE 4 40.0 parts of finely crystalline 2,4,5-trichloroaniline are stirred overnight in a mixture of 200 parts of water, 200 parts by volume of 30% strength hydrochloric acid and 0.5 part of a secondary alkanesulfonate (chain length in the alkyl radical 60% C13 -C15 and 40% C16 -C17). After addition of ice to the hydrochloride suspension formed, the amine is diazotized by rapidly feeding in 29 parts by volume of a 40% strength aqueous sodium nitrite solution, and the mixture is subsequently stirred with a nitrite excess for 1 hour. The excess nitrite ions present therein are then destroyed by means of sulfamic acid, the diazonium salt solution is clarified and 5 parts of methacrylamide are added. 64.5 parts of 2-hydroxy-3-naphthoic acid N-(4-ethoxyphenyl)-amide are dissolved at 80°-85° C. in 400 parts of water, to which 28 parts by volume of 33% strength sodium hydroxide solution have first been added, in a coupling vessel. The clear solution thus obtained is cooled to 5°-10° C. by introduction of ice, after addition of 15 parts by volume of a 10% strength aqueous solution of the abovementioned alkanesulfonate, and 25 parts by volume of glacial acetic acid are added, while stirring, the coupling component precipitating in finely divided form. Coupling is now carried out at 15°-25° C. by dropwise addition of the above diazonium salt solution to the initially prepared suspension of the 2-hydroxy-3-naphthoic acid arylide in the course of 2 hours, the pH of the reaction mixture being kept in the range from pH 4.5 to 4 by dropwise addition of 10% strength sodium hydroxide solution. The violet-brown coupling product 3-hydroxy-N-(4-ethoxyphenyl)-4-(2,4,5-trichlorophenyl)azo- 2-naphthalene-carboxamide (CAS No. 5012-29-3) obtained when coupling is complete and isolated in the customary manner has an analytically determined PCB content of 18 μg/g (18 ppm). EXAMPLE 5 Comparison Test If the azo pigment described in Example 4 is again synthesized by the process corresponding to so-called pendulum coupling but no methacrylamide has been added to the diazonium salt solution here, the coupling product obtained contains more than 50 μg/g of hexachlorobiphenyls (more than 50 ppm of PCBs). EXAMPLE 6 32.2 parts of2,2',5,5'-tetrachloro-4,4'-diamino-biphenyl are stirred for 8 hours in a mixture of 85 parts by volume of water and 85 parts by volume of 30% strength hydrochloric acid. The diamine hydrochloride formed in this way is then diazotized at 0°-10° C. by dropwise addition of 28 parts by volume of a 40% strength aqueous sodium nitrite solution. When the diazotization is complete, the resulting bisdiazonium salt solution is diluted to 400 parts by volume by making up with water and filtered, with addition of silica gel, and any excess of nitrous acid present in the filtrate is destroyed by means of sulfamic acid. 47 parts of acetoacetic acid 2-methyl-4-chloro-anilide are stirred in 400 parts by volume of water in a second vessel and dissolved by adding 20 parts by volume of 33% strength sodium hydroxide solution. The resulting clear solution is now cooled to 10° C., 1 part of the alkanesulfonate described in Example 4 is added and the coupling component is then precipitated, while stirring, by addition of 14 parts by volume of glacial acetic acid in which 1 part of dimethyl-diallyl-ammonium chloride and 3 parts of 2-hydroxyethyl methacrylate are dissolved. The coupling itself is carried out by dropwise metering of the above bisdiazonium salt solution, at 15°-20° C. in the course of 2 hours, into the coupling suspension initially prepared. As soon as the pH of the reaction mixture has fallen from initially 5.5 to pH 4 to 3.5, feeding in of 6% strength sodium hydroxide solution is started in order to keep the pH range between 4 and 3.5 during this reaction phase. When the coupling has ended, the suspension is heated to 95° C and is subsequently stirred at the elevated temperature for a further hour, and the pigment which has precipitated is filtered off, washed salt-free with water and dried. The coupling product thus obtianed, C.I. Pigment Yellow 113 - No. 21126 (CAS No. 14359-20-7) has a tetrachlorobiphenyl content of 22 μg/g (22 ppm). EXAMPLE 7 32.2 parts of 2,2', 5,5'-tetrachloro-4,4'-diamino-biphenyl are diazotized as described in Example 6. 3 parts of 2,2-bisacrylamidoacetic acid, dissolved in 20 parts by volume of water, are then added to the bisdiazonium salt solution obtained after filtration. Meanwhile, a solution of 42 parts of acetoacetic acid 2,4-dimethyl-anilide in a mixture of 800 parts by volume of water and 20 parts by volume of 33% strength sodium hydroxide solution has been prepared in a separate dissolving vessel. For the coupling, the solutions of the two reaction components made up to equal volumes are metered simultaneously, while stirring, into an acetic acid/sodium acetate buffer mixture which has been initially prepared and to which 2 parts of a condensation product of stearyl alcohol and 18 equivalents of ethylene oxide have been added. During this procedure, the pH in the coupling vessel varies between pH 5.5 and 4.5. A content of polychlorinated biphenyls of 23 μg/g in total (23 ppm of PCBs) is determined analytically in the disazo compound C.I. Pigment Yellow 81 - No. 21127 (CAS No. 22094-93-5) isolated in the customary manner after coupling. EXAMPLE 8 Comparison Test If the coupling described in Example 7 to give C.I. Pigment Yellow 81 (No. 21127) is carried out, in contrast, in the absence of the acrylamide derivative used in that example, the resulting coupling product has a PCB content of 70 μg/g (70 ppm). I claim: 1. A process for the preparation of a monoazo pigment of the formula (I) ##STR4## or of a disazo pigment of the formula II ##STR5## in which n is 1, 2 or 3, m is 1 or 2, K1 and K2 are each the radical of an acidic CH coupling component H--K1 or H--K2 from the acetoacetic acid arylamide or naphthol series or of a heterocyclic structure and K1 and K2 are identical or different, which contains not more than 25 μg of polychlorinated biphenyls (PCBs) per gram of pigment, by azo coupling in an aqueous medium, which comprises carrying out the coupling reaction in the presence of olefins of limited or unlimited water-solubility of the formula III ##STR6## in which R is a hydrogen atom or an alkyl or alkoxy group andX is a radical of the formula --COOR1, --CONHR2 or --NR3 COR4 or--if R is not alkoxy--is also the radical --CN, in which R1 is hydrogen, alkyl or alkyl which is substituted by 1 or more radicals from the group comprising hydroxyl, alkoxy, amino, alkylamino and dialkylamino, R2 is hydrogen, alkyl or alkyl which is substituted by 1 or more radicals from the group comprising hydroxyl, alkoxy, amino, alkylamino, dialkylamino, sulfo, carboxyl, alkoxycarbonyl and saturated or unsaturated alkanoylamino as well as corresponding N-alkanoyl-N-alkyl-amino, R3 is hydrogen or alkyl and R4 is alkyl. 2. The process as claimed in claim 1, wherein, in the olefins of the formula III,R is hydrogen, C1 -C4 -alkyl or C1 -C4 -alkoxy, and the radical X has the meaning shown for this in claim 1 by the groupings mentioned therein, in which case R1 is hydrogen or C1 -C4 -alkyl which can be substituted by 1 or 2 radicals from the group comprising hydroxyl, C1 -C4 -alkoxy, amino, N-(C1 -C4 -alkyl)-amino and N,N-di-(C1 -C4 -alkyl)-amino; R2 is hydrogen or C1 -C4 -alkyl which can be substituted by 1 to 3 radicals from the group comprising hydroxyl, C1 -C4 -alkoxy, amino, N-(C1 -C4 -alkyl)-amino, N,N-di-(C1 -C4 -alkyl-amino, sulfo, carboxyl, (C3 -C5 -alkoxy)-carbonyl, N-(C2 -C5 -alkanoyl)-amino and N-)C3 -C5 -alkenoyl)-amino; R3 is hydrogen or C1 -C4 -alkyl, and R4 is C1 -C4 -alkyl. 3. The process as claimed in claim 1 or 2, wherein, in the olefins of the formula III,R is hydrogen, methyl, methoxy or ethoxy, and the radical X has the meaning shown for this in claim 1 by the grouping mentioned therein, in which case R1 is hydrogen, methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-aminoethyl, 2-(dimethylamino)ethyl, 3-aminopropyl or 3-(dimethylamino)-propyl, R2 is hydrogen, C1 -C4 -alkyl or C1 -C4 -alkyl which is substituted by 1 or 2 radicals from the group comprising hydroxyl, methoxy, ethoxy, amino, methylamino, ethylamino, N,N-dimethylamino, N,N-diethylamino, sulfo, carboxyl, acetamido and acrylamido, R3 is hydrogen, methyl or ethyl and R4 is methyl or ethyl. 4. The process as claimed in claim 1 wherein, in the olefins of the formula III, the radical X is the grouping --CONHR2. 5. The process as claimed in claim 1 wherein the olefins of the formula III are employed in an amount of 0.01 to 1% by weight, based on the aqueous pigment suspension obtained after the azo coupling. 6. The process as claimed in claim 5, wherein the amount of olefins employed is 0.05 to 0.5% by weight. 7. The process as claimed in claim 1 wherein the olefins of the formula III are employed in an amount of 0.1 to 10% by weight, based on the amount of pigment formed in the coupling. 8. The process as claimed in claim 7, wherein the amount of olefins employed is 0.5 to 5%. 9. The process as claimed in claim 1 wherein the azo coupling is carried out under the action of a buffer mixture at a pH in the range from 4 to 7. 10. A pigmenting printing ink, a lacquer, an emulsion paint, a plastic, an electrophotographic toner, an ink jet ink, or a heat transfer tape, which is colored, wherein the coloring agent comprises an azo pigment prepared by the process of claim 1. 11. A method for coloring a pigmenting printing ink, a lacquer, an emulsion paint, a plastic, an electrophotographic toner, an ink jet ink, or a heat transfer tape, comprising the step of incorporating an azo pigment prepared by the process of claim 1.

1990-06-16

en

1993-09-07

US-10053761-A

Planographic printing plates United States Patent-O 3,227,975 PLANOGRAPHIC PRINTING PLATES Samuel Guastella, Westminster, Edward J. Guerra, Fitchburg, D. D. Uong, Leominster, and Wyman F. Uhl, Ashby, Mass., assignors, by mesne assignments, to Fitchburg Paper Company, a subsidiary of Litton Industries, Inc, a corporation of Delaware No Drawing. Filed Apr. 4, 1961, Ser. No. 100,537 6 Claims. (Cl. nib-149.2) Our invention relates to planographic printing plates, and particularly to improved paper base planographic plates and a rapid and simplified method of manufacturing the same. In planographic printing, the print is formed by pressing the surface to be inked against a smooth plate which has been selectively inked in areas defining the reverse of the print. The process requires a plate having imaged areas which are receptive to the ink, with the remaining, unimaged areas being ink repellent so that by contacting the plate with an inking roller, ink is applied only to the imaged areas. Ordinarily the plate is first wet outwith an aqueous solution to render the unimaged areas incapable of picking up the ink, while the imaged areas, having an oleophilic, hydrophobic character, remain dry. Then, by contacting the plate with an inking roller, ink is applied selectively to the imaged areas. Plates commonly available consist of a suitable backing material, typically metal, plastic or paper, having a surface which may be uniformly wet with water but which also possesses an affinity for the image. A characteristic of these plates is a durable surface capable of being wet with .water and rendered thoroughly ink repellent while also being highly retentive of the imaging material which is repellent to Water. Paper base planographic plates are commonly used for short and medium run work, and are particularly suitable for ofiice work because they can be imaged directly by marking or typing with readily available pencils, crayons, ball-point pens, or typewriter ribbons. Such plates generally comprise a clay-coated paper base having a surface covering of a hydrophilic, but insoluble, coating material which ordinarily includes a pigment filler such as clay, blanc fixe, colloidal silica or the like. T e surface must possess a rather critical balance between its hydrophilic and oleophilic characteristics so as to be readily wet with water, and also retentive of ink-receptive imaging material, which is generally oleaginous. The success of any plate depends on its surface being durable so as to resist deterioration from repeated wett-ings, inkings, and pressings, while retaining its water receptive and image retentive properties. Paper base plate suitable for direct imaging should also be sufiiciently durable to permit erasures without destruction of the planographic surface. Paper plates currently avail-able are generally made by coating a coated paper base stock with an aqueous emulsion, solution or suspension containing a film-forming material, such as casein, starch, carboxy methyl cellulose, albumin or polyvinyl alcohol, then drying the coating and further processing the sheet to render the coating insoluble. This type of processing, while producing satisfactory plates, is relatively complex in that successive operations are necessary, and each of them requires careful control of both the compositions and the conditions of application. Numerous disadvantages also result from the application of the planographic coating from a water base. A tendency to curl may develop which requires still further treatment, such as coating the backside, to reduce the curl or to avoid other complications impairing usefulness. Moreover, the surface of the base stock, which ordinarily carries a clay coating, may become disrupted during the coating operation so as to require calendering, super- US. Patent No. 3,083,639. aware, the most promising development in the art prior "ice calendering, or other remedial treatment after the coating operation. We have found that it is possible to make a satisfactory planographic printing plate by treating a non-planographic paper base with an essentially aqueous solution of colloidal silica, and for example, we have had reasonably successful results with plates prepared by treating a paper base With a suspension of Ludox SM colloidal silica, as obtained from E. I. du Pout de Nemours and Co., Inc., in an aqueous solution containing between 30 and 70 volume percent of acetone, the suspension containing 1 percent silica solids by weight. However, the difliculties encountered in manufacturing paper plates by methods employing aqueous systems may be avoided by making plates by treating a paper base with essentially organic solutions. Among such solutions, we have successfully employed an organic suspension containing 1 percent of Davidson 79 silica gel in equalvolumes of methyl ethyl ketone and methanol, and We have also employed a 1 percent suspension of Cab-O-Sil M5 silica in ethyl ether. Still better results may be obtained by employing dispersions of silica obtained by hydrolizing ethyl silicate, in any of the ways taught in United States application for Letters Patent Serial No. 824,942, filed July 6, 1959, by John Frank Thurlow, for Pl-anographic Printing Plates and Processes for Making the Same, now Thus, so far as we are to our invention has been the plates prepared in accordance with the afores-aid application Serial No. 824,942, employing a planographic coating of hydrolized ethyl silicate. However, planographic plates made in accordance with the aforesaid application still leave something to be desired in rapidity of image buildup, cleanup characteristics, practical length of run, era-sure property, and ink spotting. Accordingly, it is a primary object of our invention to provide a planographic printing plate improved in all of the characteristics over the best prior planographic plates. .11: is a further object of our invention to provide an improved treating suspension for imparting planographic properties to non-planographic surfaces. It is a further object of our invention to provide an improved process for making high quality planographic printing plates which'is rapid, simple and inexpensive. Briefly described, a lanographi-c printing plate in accordance with our invention comprises a non-planographic flexible base on the surface of which aredispersed-particles of a partially hydrolized alkyl silicate. By microscopic examination, these particles are found to be relatively unagglomcrated and to be of a characteristic range of sizes. Upon chemical analysis, the surface composition of our improved plate is found to have a characteristic ratio of silicon to organic constituents. Our improved plates are manufactured, in accordance with a preferred embodiment of our invention, by treating a paper base sheet-coated with a non-planographic coating of clay and latex with an improved treating suspension prepared by heating a suspension of a lower alkyl silicate in a'solution including a water-miscible, polar organic solvent'consisting at least in part of dimethyl formamide ordimethyl acct-amide, water, and ammonia or an alkyl amine. The application of a partially hydrolized alkyl silicate suspension in accordance with our invention will impart planographic properties to any kind of paper base whose surface is 'not too oleophilic or hydrophilic. Best results, however, are obtained when the base sheet is a clay coated paper, in which the clay coating serves as a barrier capable of preventing the penetration of water into the paper base. The application of barrier coats is commonly employed for this purpose and is not novel with plates prepared according to this invention. However, a barrier coat is necessary if a plate of highest durability and performance is to be produced, and may in that sense be considered as contributing to the ultimate utility of the invention. While many suitable clay coated papers are known to the art which may be successfully employed in the practice of our invention, the following is a formulation that we have found most satisfactory: CLAY COATING FORMULA Parts by Weight Clay 100 Casein 18.0 Latex 6.0 It is important that this coating, or other coatings which may be applied to a flexible base in the practice of our invention, be free of deformers, stearates, plasticizers and other oily substances that might impart oleophilic properties to our planographic surface. The latex in the coating may be butadiene-styrene, such as Dow 512 R, available from the Dow Chemical Company. It is provided to make the coated base waterproof and flexible, and to impart wet-rub resistance to the clay coating. It also contributes to image retention. The formulation of the novel treating suspension of our invention, in accordance with the preferred embodiment thereof, may best be understood from the following examples, which we have used to make planographic plates of excellent quality capable of giving more than 2,000 useful copies: Example I Parts by volume Condensed ethyl silicate 28.8 Dimethyl formamide 36.9 Methanol a 24.6 Aqueous NH OH (28% NH 4.4 Distilled H O 3.3 The ammonia is diluted with the water. The condensed ethyl silicate, dimethyl formamide, and methanol are combined, and then added to the ammonia solution in a vessel provided with circulating water coils. The vessel is closed, and the contents are reacted at elevated temperatures with a gradual rate of temperature rise from 70 F. to 131 F. over a 6 hour period. The rise of the temperature curve should be a smooth one with no sudden, erratic maxirna or minirna. The temperature rise is controlled by controlling the temperature and rate of flow of the water in the cooling coils. The reaction temperature and time affect the colloidal particle size and the degree of substitution of the ethyl groups in the reaction product. The particle size of the planographic coatings will influence the image retention on the plate. For a desirable predetermined end product, rate of temperature increase correlates with the percentage of water and ammonia contained in the formula. In other words, the formula may be designed for rapid or slow reaction depending on the reaction equipment. Example II Parts by volume Condensed ethyl silicate 28.8 Dimethyl acetamide 36.9 Methanol 24.6 Aqueous ammonia (28% NH 4.4 Distilled H O 3.3 When reacted as described in connection with Example I above, the formulation of Example 11 produced an excellent treating suspension having the sa-rne properties as the formulation of Example I. The application of partially hydrolized ethyl silicate from the above suspensions to a suitable base produces a firmly bonded coating which is microscopically grained, because of the particulate nature of the siliceous reaction product, but which aproaches a uniform film. This coating differs from that obtained from an aqueous dispersion of silica, in that there is a tendency for the silica in the latter to agglomerate, and in that the coat that is formed from the aqueous dispersion is in the nature of relatively few, highly concentrated, deposits of agglomerated particles which adhere with much less strength and are consequently easily removed. The surface formed from an aqueous suspension is neither durable nor possesses good planographic properties, probably because a uniform siliceous deposit is not formed. The coating formed by our suspension differs from those obtained from organic dispersions of silica in that the siliceous coating is much more firmly bonded to the base. Also, the wearing properties are generally superior, particularly with regard to the ability of the planographic surface to withstand erasures. The application of a partially hydrolized ethyl silicate coating from an organic suspension results in a finely textured siliceous surface, with the siliceous particles covering substantially all of the base coating and constituting a textured surface. The siliceous nature of the surface renders it readily wet with water, While its organic constituent, finely textured nature can be visualize-d as providing excellent image retention. We have analyzed the films deposi ed from our suspensions by drying coatings of the suspensions on a Mylar polyester film, and then subjecting the deposits to chemical analysis. From a suspension prepared in accordance with Example I above, we obtained deposits having the following analysis, in terms of percent by weight. Constituent: Percent by wt. C 6.71 C H O 3.15 Thus, the optimum degree of partial hydrolysis would appear to be that resulting in film deposits incorporating approximately 6.7 percent of carbon. Since the complete hydrolysis of the silicate would leave essentially no organic constituents in the film deposits, the percentage of carbon is an eifective indication of the degree of hydrolysis. We have found that the extent of hydrolysis determines the relative oleophilicity and hydrophilicity of the planographic surface formed, and that the partial hydrolysis may be carried out far enough to leave only about 2 percent of carbon in the film deposits, or may be restricted so long as the dried film retains a sufficiently hydrophilic character. That is, the hydrolysis must be carried at least to the extent that paper plates made from the resulting suspensions and wet with water will not pick up ink in their unimaged areas, as can readily be determined by routine experimentation without the exercise of invention. It should be understood that some variation in the formulation of the treating suspension of our invention can be made. For example, we have experimented with suspensions in which the ammonia was varied from 25% less than that given above to 25 more, by volume, with reasonably successful results at both extremities. Examination of electron microscope photomicrographs of surface deposits from such suspensions containing excess, deficient, and normal amounts of ammonia (as defined by the above example) show a progressive variation in particle size, with the smaller particles occurring in the deposit from the ammonia-deficient suspension, and the larger particles occurring in the deposits from the excessively ammoniated suspensions. The particle size for optimum results appears, from measurement made on these photomicrographs, to lie in the range from about 10 to millimicrons. As another indication of the particle size, the suspended particles are sufliciently colloidal to exhibit a Tyndal effect, without being sufficiently small to form a clear solution nor sufficiently large to give a milky suspension. We have also made planographic plates using diethyl amine as the hydrolysis agent. These plates, while not meeting the standards of plates prepared with ammonia as the hydrolysis agent, are still of good quality. Thus, it is apparent that in the broader aspects of our invention diethyl amine, or, from known chemical principles, any of the lower alkyl amines, can be employed as the hydrolysis agent. On the other hand, other bases, such as tie carbonates, bicarbonates and hydroxides of sodium and potassium, cannot be successfully employed. While the amount of water used in Examples I and II appears to be the optimum, we have found that the Water content may be varied over a considerable range. Thus, we have prepared planographic plates from suspensions to which no water other than that present in the aqueous ammonia has been added, and also from suspensions containing ten times the amount of water added in Examples I and II. As water is increased or decreased in the formulation of the treating suspension, from the optimum quantity, a gradual decrease in the quality of the plates is observed, although all have useful planographic properties. The organic solvent used in preparing the treating suspensions of our invention should contain at least a portion of either dimethyl acetamide or dimethyl formamide, since we have found no other solvent that will produce plates of the same quality. The balance of the solvent is preferably methanol, but methyl ethyl ketone, and presumably any other unreactive, water-miscible, polar organic solvent, may be employed. From experiments in which the proportions of dimethyl formamide and methanol were varied, from 25 percent by volume of dimethyl formamide to pure dimethyl formarnide, we have found that optimum results are secured with the organic solvent of Example 1, containing 60 percent dimethyl formamide and 40 percent methanol by volume, but that planographic plates can be made with all of the variations. In decreasing order, the acceptibility of plates made with the various solvent proportions is as follows; values are in parts by volume. Dimethyl Formamide: Methanol 60 40 Although the examples given employ only condensed ethyl silicate as the siliceous starting material, it is believed apparent from known principles of chemistry that other alkyl silicates, and particularly the lower alkyl silicates, would have partial hydrolysis, products of similar properties. Accordingly, other alkyl silicates may be employed if so desired without departing from the scope of our invention. While we have given various examples and illustrations of our invention, many changes and variations will be apparent to those skilled in the art upon reading our description, and these can be made without departing from the scope of our invention. Having thus described our invention, what we claim is: l. A planographic printing plate comprising a paper base sheet having a printing face carrying as its principal planographic component particles of colloidal dimensions of between 10 millimicrons and 50 millimicrons of the product obtained by partially hydrolyzing a lower alkyl silicate by reacting water and ammonia with a mixture of said lower alkyl silicate and a solvent which solvent comprises 25 to percent of material selected from the class consisting of dimethyl formamide and dimethyl acetamide and the balance of which solvent consists of an unreactive water-miscible polar organic solvent, the rela tive proportions of reactants being: Parts by volume Alkyl silicate 28.8 Ammonia as aqueous 28% 3.3-5.5 Additional water 0-33 thereby to produce a siliceous hydrolyzate with residual organic constituents containing at least about 2% of the weight of said hydrolyzate of carbon, but less than enough to impair the essential water receptive surface characteristics of the planographic surface. 2. The product defined by claim 1, wherein the alkyl silicate is ethyl silicate. 3. The product defined by claim 1, wherein the alkyl silicate is condensed ethyl silicate the polar organic solvent is methanol, and the proportions of ammonia and water are respectively about 4.4 and 3.3. 4. The method of making paper base planographic printing plates, comprising the steps of partially hydrolyz ing a lower alkyl silicate dispersed in a solvent which comprises from 25 to 100 percent of material selected from the class consisting of dimethyl formamide and dimethyl acetamide and the balance consists essentially of an unreactive water-miscible polar organic solvent, by reacting said silicate with ammonia and water, the relative proportions of reactant being: Parts by volume Lower alkyl silicate 28.8 Ammonia, as aqueous 28% 3.3-5.5 Additional water 0-33 thereby to produce a reaction product mixture containing a partial hydrolyzate of the lower alkyl silicate in the form of colloidial particles of between 10 millimicrons and 50 millimicrons of siliceous material with residual organic constituents containing at least about 2% of the weight of said siliceous material of carbon, coating the reaction product mixture on a paper base, and drying the coated base. 5. The method defined by claim 4, wherein the alkyl silicate is ethyl silicate. 6. The method defined by claim 4, wherein the alkyl silicate is condensed ethyl silicate the polar organic solvent is methanol, and the proportions of ammonia and water are respectively about 4.4 and 3.3. References Cited by the Examiner UNITED STATES PATENTS 2,132,443 10/1938 Simons 101-149.2 2,395,880 3/1946 Kirk 260-4488 2,408,654 11/ 1946 Kirk 252-309 3,017,826 1/1962 Salzberg 101-149,2 3,028,804 4/1963 Neugebauer et al. 101-1492 3,083,639 4/1963 Thurlow 101-1492 DAVID KLEIN, Primary'Examiner. RICHARD D. NEVIUS, Examiner. 1. A PLANOGRAPHIC PRINTING PLATE COMPRISING A PAPER BASE SHEET HAVING A PRINTING FACE CARRYING AS ITS PRINCIPAL PLANOGRAPHIC COMPONENT PARTICLES OF COOLOIDAL DIMENSIONS OF BETWEEN 10 MILLIMICRONS AND 50 MILLIIMICRONS OF THE PRODUCT OBTAINED BY PARTIALLY HYDROLYZING A LOWER ALKYL SILICATE BY REACTING WATER AND AMMONIA WITH A MIXTURE OF SAID LOWER ALKYL SILICATE AND A SOLVENT WHICH SOLVENT COMPRISES 25 TO 100 PERCENT OF MATERIAL SELECTED FROM THE CLASS CONSISTING OF DIMETHYL FORMAMIDE AND DIMETHYL ACETAMIDE AND THE BALANCE OF WHICH SOLVENT CONSISTS OF AN UNREACTIVE WATER-MISCIBLE POLAR ORGANIC SOLVENT, THE RELATIVE PROPORTIONS OF REACTANTS BEING:

1961-04-04

en

1966-01-04

US-23264662-A

Haloalkyldihydroxyoxahexyl hydrocarbonthiophosphonates United States Patent 3,201,440 HALUALKYLDIHYDROXYOXAHEXYL HYDRO- CARBUNTHIUPHDSPHONATES Q 7 David D. Reed, Glenham, N.Y., James M. Petersen, Fishkill, N.Y., and Herman D. Kluge, deceasedylate of Fishlriil, N.Y., by Hazel E. Kluge,.administratrix, Fish- 7 kill, N.Y., asignors to Texaco Inc, New York, N.Y., a corporation of Delaware No Drawing. Filed Oct. 18, 1962, Ser. No. 232,646 ' 8 Claims. (CL 260-461) This invention relates to novel reaction products of haloalkylhydroxyalkyl hydrocarbonthiophosphonates and hydroxyepoxyalkanes. More particularly, it pertains to haloalkyldihydroxyoxahexyl hydrocarbonthiophosphonates and their method of manufacture. The hydroxyepoxyalkane hydrocarbonthiophosphonate reaction products contemplated herein have been found to be effective as thermal stability additives for fuels, e.g., jet fuels. The haloalkyldihydroxyoxahexyl hydroearbonthiophosphonates, hereafter known as the oxahexyl thiophosphonates for reasons of brevity, are represented by the following formula: where R is a monovalent hydrocarbon derived radical (hydrocarbyl), R and R? are radicals selected from the group consisting of hydrogen, alkyl of from 1- to 6 carbon atoms and halogenated alkyl radicals from 1 to 6 carbon atoms, at least one of said R and R groups being haloalkyl, R and R are radicals selected from the group consisting of hydrogen and alkyl from 1 to 6 carbon atoms, and X is sulfur or a mixture of sulfur and oxygen. By the term haloalkyl we intend alkyls having one to all of the hydrogens thereon substituted with halogen. Broadly, the novel compounds of the invention are prepared by reacting at elevated temperatures a hydroxyepoxyalkane with a haloalkylhydroxyalkyl hydrocarbonthiophosphonate and optionally in the presence of an acid as catalyst such as Lewis acids, organic acids, and mineral acids. PREPARATION OF THE HALOALKYLHYDROXY- ALKYL HYDROCARBONTHIOPHOSPHONATE REACTANT The haloalkylhydroxyalkyl hydr'ocarbonthiophosphonates and their method of manufacture are described in coassigned, copending application Serial No. 232,659, filed October 18, 1962. As described therein the haloalkylhydroxyalkyl hydrocarbonthiophosphonates are dephonic acid is derived from a hydrocarbon-P 8 reaction product. In the preparation of the hydrocarbonthiophosphonic acid, a reaction mixture of P 8 and hydrocarbon comprising 5-40 wt. percent P 8 is heated at a temperature between about 100320 C. in a nonoxidizing atmosphere, for example, under a blanket of nitrogen. The resultant product is hydrolyzed at a rived from hydrocarbonthiophosphonic acids and halo- 5 allcylene oxide and in turn the hydrocarbonthiophostemperature between about and 260 C. by con- 3,201 ,440 Patented Aug. 17, 1965 ice 20 to 200 carbon atoms and X is sulfur or amixture of oxygen and sulfur. X in the above formula is designated sulfur or a mixture of sulfur and oxygen because the steam hydrolysis treatment often results in replacement of a portion of sulfur joined to the phosphorus with oxygen. The monovalent hydrocarbon derived radical represented by R in the previous formula is derived from the hydrocarbon which formed the initial hydrocarbon- P S reaction product. The hydrocarbons utilized can be aliphatic, cycloaliphatic, aromatic, alkarene or aralkane hydrocarbons. Lubricating oil fractions and cracked hydrocarbon fractions also comprise another desirable class of hydrocarbon materials for reaction with P 8 The preferred hydrocarbons for reaction with P 8 are olefins. The olefinic hydrocarbons advantageously contain at least 12 carbon atoms although lower molecular weight olefins can be employed. Examples of mono-olefin polymers are polyisobutylene, polybutylene, polyproylene. Copolymers of olefins illustrate another type such as the copolymer of butadiene and isobutylene. Generally, olefin polymers and copolymers having an average molecular weight between 250 and 50,000 are employed. Polymers and copolymers having an average molecular weight from 600 to 5,000 are preferred. One specific preferred monoolefin polymer is polybutene having an average molecular weight between 600 and 5,000. Examples of haloalkylhydroxyalkyl hydrocarbonthiophosphonates reactants contemplated herein are 3-chloro- 2-hydroxypropyl polybutene (780 M.W.) thiophosphonate, 3-chloro-2-hydroxypropyl polybutene (940 M.W.) thiophosphonate, l-fiuoromethyl-Z-hydroxy 3-fluoropropyl polybutene (1200 M.W.) thiophosphonate, 1-lT,2-dibromoethyl)-2-hydroxy-3-bromopropyl polybutene (1200 M.W.) thiophosphonate, and 3-bromo-2-hydroxypropyl polyisobutylene (2500 M.W.) thiophosphonate. HY DROXYEPOXY ALKANE REACTANT The hydroxyepoxyalkanes suitable for reaction with the thiophosphonate reactant for forming the desired oxahexyl thiophosphonates of the invention have the general formula: where R and R are hydrogen or an alkyl from 1 to 6 carbons. Examples of the hydroxyepoxyalkane contemplated herein are 3-hydroxy-1,2-epoxypropane, 4-hydroxy- 3 phonates. The catalyst contemplated herein are the Lewis acids, mineral acids and organic acids. Specific examples of such catalyst are BF -C H OC H (boron trifluoride etherate), 3P3, HF, A1C13' sl'lclly Tlch, 211012, 1131304, H 80 and CCl CO H. PREPARATION OF THE OXAHEXYL HYDRO- CARBONTHIOPHOSPHONATE PRODUCT Specifically, the oxahexyl hydrocarbonthiophosphonate product is prepared by reacting the haloalkylhydroxyalkyl hydrocarbonthiophosphonate with the hydroxyepoxyalkane with or withoutthe presence of an acid substance as catalyst at a temperature between about and 150 C., in a reactant mole ratio of hydroxyepoxyalkane to thiophosphonate reactant to catalyst of between about 0.1:1:0.01 and 52120.1. Although superatmospheric and subatmospheric pressure may be employed, atmospheric pressure is normally utilized. The product is purified by standard means such as stripping out the unreacted reactants at elevated temperature (e.g., above 75 C.) and reduced pressure (between 0.1 and mm. Hg) utilizing an inert gas such as nitrogen as stripping agent. Specific examples of the oxahexyl hydrocarbonthiophosphonates contemplated herein are 2-chloromethyl-5,6-dihydroxy-S-oxahexyl polybutene (940 M.W.) thiophosphonate; 2-bromomethyl-5,6-dihydroxy-3-oxahexyl polybutene (940 M.W.) thiophosphonate; 1,2-di(fluoromethyl)-4,6-diethyl-5,6 hydroxy 3-oxahexyl polypropylene (1500 M.W.) thiophosphonate; and l-ethyl-Z-(chloromethyl)-4-methyl-5,6-dihydroxy-3-oxahexyl polymethylene (2500 M.W.) thiophosphonate. The following examples further illustrate the invention by demonstrating the preparation of the oxahexyl thiophosphonates but are not to be construed as limitations thereof. Example I 355 grams of a mineral oil solution containing 0.1 mole of 3-chloro-2-hydroxypropyl polybutene (940 M.W.) thio phosphonate of the formula: where R is a polybutene radical having an average molecular weight of 940 and X is a mixture of oxygen and sulfur (0.5 wt. percent sulfur) were added to a 1 liter, 3-necked flask equipped with a stirrer, dropping funnel, gas inlet tube, thermometer and reflux condenser. In addition 7.5 grams (0.1 mole) of glycidol and 1.4 (0.01 mole) boron triiluoride etherate were added. The reaction mixture was heated to 93 C. with stirring and nitrogen blowing for where R is a polybutene radical having an average molecular Weight of 940 and X is a mixture of sulfur and oxygen. This product analyzed as follows: Description Calculated Found Phosphorus, wt. percent 0.85 1.0 Hydroxyl No 27 25 Neut. No 0 2. 44 4 Example I! where R is a polybutene radical having an average molecular Weight of 940 and X is a mixture of oxygen and sulfur (0.5 wt. percent sulfur). Also, 7.8 grams (0.105 mole) of glycidol were employed. The stripped product was found to be Z-bromomethyl-S,6-dihydroxy-3-oxahexyl polybutene (940 M.W.) thiophosphonate of the formula: where R and X are as heretofore defined. This product analyzed as follows: Description Calculated Found Phosphorus, weight percent 1.19 1.1 43 30 0 0. 54 1y phosphonate reactant in product 1 1 We claim: 1. A haloalkyldihydroxyoxahexyl hydrocarbonthiophoswhere R is hydrocarbyl derived from an aliphatic polyolefin having an average molecular weight between 250 and 50,000, R and R are selected from the group consisting of hydrogen, alkyl from 1 to 6 carbons and haloalkyl from 1 to 6 carbons, at least one of said R and R groups being said haloalkyl, R and R radicals selected from the group consisting of hydrogen and alkyl of from 1 to 6 carbons and X is a chalcogen selected from the group consisting of sulfur and a mixture consisting of a major portion of sulfur and a minor portion of oxygen. 2. A thiophosphonate in accordance with claim 1 wherein, X is a mixture consisting of a major portion of sulfur and a minor portion of oxygen, R R and R are hydrogen and R is haloalkyl. 3. A thiophosphonate in accordance with claim 2. wherein R is chloromethyl. 4. A thiophosphonate in accordance with claim 2 Wherein R is bromomethyl. 5. A method of preparing a haloalkyldihydroxyoxahexyl hydrocarbonthiophosphonate of the formula: where R is hydrocarbyl derived from an aliphatic polyole- :fin having an average molecular weight between 250 and 50,000, R and R are radicals selected from the group consisting of hydrogen, alkyl of from 1 to 6 carbons and prising contacting a haloalkylhydroxyalkyl hydrocarbonthiophosphonate of the formula: i i RP-O(I3HCHOH with a hydroxyepoxyalkane of the formula: a R4 5 CHCH- HOH wherein R, R R R R and X as are heretofore defined, at a temperature of between about 25 and 150 C., in a mole ratio of said hydroxyepoxyalkane to thiophosphonate reactant of between about 0.121 and 5:1. 6. A method in accordance with claim 5 wherein said method is conducted in the presence of said as catalyst, said acid selected from the group consisting of 6 BF3, HF, Alclg, SnCl ZnCl H3PO4, H2804 and CCl CO H and in a mole ratio of said hydroxyepoxyalkane to said thiophosphonate reactant to said catalyst of 0.1:1:0.01 to 521:0.1, R R and R are hydrogen and X is a mixture consisting of a major portion of sulfur and a minor portion of oxygen. 7. A method in accordance with claim 6 wherein R is a polybutene radical having an average molecular Weight of 940, R is chloromethyl and said catalyst is boron trifluoricle etherate. 8. A method in accordance with claim 6 wherein R is a polybutene radical having an average molecular weight of 940, R is bromomethyl, and said catalyst is boron tn:- fluoride etherate. No references cited. CHARLES B. PARKER, Primary Examiner. IRVING MARCUS, Examiner. 1. A HALOALKYLDIHYDORXYOXAHEXYL HYDROCARBONTHIOPHOSPHONATE OF THE FORMULA 5. A METHOD OF PREPARING A HALOALKYLDIHYDROXYOXAHEXYL HYDROCARBONTHIOPHOSPHONATE OF THE FORMULA:

1962-10-18

en

1965-08-17

US-72825976-A

Disinfectant composition comprising pinanol ABSTRACT A disinfectant composition comprises a germicidally effective amount of pinanol dispersed in a fugitive carrier, preferably water. BACKGROUND OF THE INVENTION The present invention relates to a pinanol and more particularly to its use in a disinfectant composition. Heretofore, the terpene alcohol pinanol has been used predominantly as an intermediate in synthesis of terpene chemicals and sparingly as a final product. For example, it is well known that linalool (an especially valuable essence for perfumes) can be synthesized using 2-pinanol as an intermediate during the synthesis (eg. British Patent No. 953,500). Typically the 2-pinanol itself is derived by catalytically hydrogenating pinane hydroperoxide with a nickel chrome catalyst (Russian Patent No. 340,648), by oxidizing pinane with a base such as sodium hydroxide (U.S. Pat. No. 3,723,542), or by various other techniques well known in the art. It now has been discovered that a highly effective disinfectant composition can be made from pinanol. SUMMARY OF THE INVENTION The present invention is a disinfectant composition comprising a germicidally effective amount of pinanol dispersed in a fugative carrier. Preferably the pinanol is 2-pinanol and the carrier is water. DETAILED DESCRIPTION OF THE INVENTION Pinanol is a bicyclic terpene alcohol. The preferred pinanol of this invention is the tertiary alcohol 2-pinanol (2,6,6-trimethyl-bicyclo (3.1.1)-heptan-2-ol). It is conceivable that various of the hydrogens could be substituted by alkyl, halogen, nitrile, and the like, i.e., having the hydroxylated carbon nucleus or skeleton of a pinanol. It also is conceivable that some unsaturation could be present. The present invention will be described in detail with 2-pinanol, though such is merely descriptive and not limitative of the present invention. The pinanol is dispersed in a fugative carrier for compounding the disinfectant composition of this invention. While the carrier can be an organic solvent, it is preferred to use water as the carrier. The carrier should be fugative preferably at about room temperature leaving no residue or at best an innocuous residue. Also, the carrier should not diminish the disinfectant qualities of the pinanol. Pinanol can be emulsified or dispersed in water conventionally with the aid of an emulsifier, dispersant, surfactant or the like. Preferably, the pinanol is emulsified in water with a soap. For efficiency and economy the soap is derived from terpene chemical operations as is the pinanol. Suitable soaps can be derived from rosin acids, fatty acids and mixtures thereof by their reaction with, for example, alkali metal or alkaline earth metal. At high concentrations of pinanol in the disinfectant composition (roughly around 80 weight percent), the pinanol can tend to crystallize from the water upon standing for extending periods of time. The pinanol can be re-dispersed by mild heating or by the addition of a clarifying agent such as an alcohol. Such alcohols include, for example, isopropanol, ethanol, primary alkanols of six to sixteen carbon atoms and various other alcohols. Such alcohols also can enhance the germicidal activity of the pinanol. Typically, from about 3 to about 12 weight percent of the alcohol is sufficient to suppress crystal formation. Alternatively, the concentration of pinanol can be decreased or the proportion of soap increased in order to prevent crystallization of the pinanol in water. The disinfectant composition also can contain odorants (eg. dipentene) to impart an odor conducive to user acceptance or can be colored for special asthetic appeal. The particular isomeric form of the 2-pinanol is not limitative in its effectiveness as a disinfectant. The proportion of cis-, and trans-2-pinanol can be typical of that normally obtained during production of the pinanol (generally a cis:trans ratio of from about 3.5:1 to 3.8:1), or such proportions can be adjusted to any convenient value that is necessary or desirable including all cis-, or all transpinanol. The effectiveness or germicidal activity of the pinanol disinfectant composition is determined by accepted methods of the art. Such methods include the AOAC phenol coefficient method and the AOAC use-dilution method of the Association of Official Analytical Chemists as found in their publication Methods of Analysis, AOAC 12th Edition, 1975, the same incorporated herein by reference. Generally, the present disinfectant composition is classified as a "janitorial or household" disinfectant effective against enteric organisms rather than a "medical or surgical" disinfectant also effective against pyogenic organisms (such as staphylococcus aureus). Further, details on this can be found in Kirk-Othmer Encyclopedia of Chemical Technology, 2nd Edition, Volume 2, pages 604/648 (Interscience Publishers, New York, New York 1964), the same expressly incorporated herein by reference. Pinanol also can be used as disinfectant additive to enhance or augment the germicidal activity of other disinfectants such as, for example, pine oil or the like. Pine oil generally contains 50-60% alpha-terpineol with lesser amounts of terpene hydrocarbons, borneol, fenchyl alcohol, related terpineols, terpene ethers, terpene ketones and terpene phenols. The proportion of pinanol in the disinfectant composition (or to be used as an additive) is related to the particular use intended therefor and the particular organisms sought to be eliminated. Typically, as little as about 10% by weight of 2-pinanol can enhance germicidal activity when used as an additive. A pinanol disinfectant composition can contain up to about 80% pinanol by weight or higher depending upon, among other factors, how well the pinanol can be emulsified and stabilized in water. The following examples show in detail how the present invention can be practiced, but they should not be construed as limiting the present invention. EXAMPLE I A 2-pinanol disinfectant composition was subjected to the AOAC phenol coefficient method in order to determine its germicidal effectiveness against salmonella typhi (Methods of Analysis, Association of Official Analytical Chemists, p. 57, 12th Edition, 1975). The disinfectant composition had the following composition by weight percent: ______________________________________ 2-pinanol (cis:trans ratio 5:1) 80.0 *SYLVATAL 40 9.0 KOH (50% aqueous solution) 3.4 Water 7.6 ______________________________________ *SYLVATAL is registered trademark of Sylvachem Corporation, Jacksonville, Florida, and SYLVATAL 40 is a distilled tall oil consisting of about 70% tall oil fatty acids and about 30% tall oil rosin acids. The phenol coefficient was determined to be 8.0. A commercial pine oil composition also was tested and found to have a phenol coefficient of only 6.5. These results clearly demonstrate the superior germicidal activity of the 2-pinanol disinfectant composition. EXAMPLE II The 2-pinanol used in these examples is made by hydrogenating pinane hydroperoxide and is recovered therefrom by conventional distillation techniques. Pinanol bottoms is the fraction of higher boiling constituants remaining from the hydrogenation-distillation operation. The pinanol bottoms contains a large proportion of α-terpineol which is the chief component of pine oil. The pinanol bottoms were formulated into a disinfectant composition and the phenol coefficient thereof determined. Pinanol bottoms have the following composition by weight percent: ______________________________________ α-terpineol 78.8 2-pinanol 13.8 linalool 1.2 related alcohols 6.2 ______________________________________ The pinanol bottoms disinfectant composition by weight percent is as follows: ______________________________________ Pinanol bottoms 80.0 SYLVATAL 40 9.0 KOH (50% aqueous solution) 3.4 Water 7.6 ______________________________________ The phenol coefficient of this disinfectant composition was determined to be 7.0. Thus, the 2-pinanol is effective as an additive to enhance the germicidal activity of conventional disinfectant compositions. EXAMPLE III The pinanol disinfectant composition of Example I was subjected to the use-dilution method in order to determine its germicidal activity against salmonella choleraesuis (Methods of Analysis, Association of Official Analytical Chemists, p. 59, 12th Edition, 1975). A use-dilution of 1:128 was found for the pinanol composition. A commercial pine oil was found to have a 1:112 use-dilution. Economic and time factors restricted further use-dilution tests; however, based on the significant phenol coefficient results reported in Example I, it is believed that a much higher use-dilution number could be displayed by the present pinanol disinfectant composition. These results, though, do demonstrate the superiority of the present pinanol composition over conventional pine oil. EXAMPLE IV Several more 2-pinanol disinfectant compositions were formulated and their stability as measured by crystal formation evaluated. In none of the following formulations did any crystals develop after extended periods of storage. The following pinanol disinfectant compositions are given by weight percent. ______________________________________ A B C D ______________________________________ 2-pinanol 64.0 50.0 25.0 73.0 SYLVATAL 40 9.0 12.5 9.0 9.0 KOH (50% aqueous solution) 3.4 4.8 3.4 3.4 Dipentene 16.0 -- -- -- Isopropanol 16.0 -- 7.0 7.0 Water 7.6 32.7 55.6 7.6 ______________________________________ The foregoing compositions display representative formulations of the pinanol disinfectant composition of the present invention. I claim: 1. A disinfectant composition for inhibiting enteric microorganisms comprising:a germicidally effecive amount of pinanol; a soap; and an aqueous carrier, said soap being in a proportion for providing a stable aqueous dispersion of said pinanol in said aqueous carrier. 2. The disinfectant composition of claim 1 wherein said soap is an alkali metal or alkaline earth metal salt of a rosin acid, a fatty acid, or mixtures of said acids. 3. The disinfectant composition of claim 1 wherein said pinanol is 2-pinanol. 4. A method for inhibiting enteric microorganisms which comprises applying thereto a disinfectant composition comprising a germicidally effective amount of pinanol stably dispersed in an aqueous carrier. 5. The method of claim 4 wherein said pinanol is 2-pinanol. 6. The method of claim 4 wherein said pinanol is stably dispersed in said aqueous carrier with the aid of a soap. 7. The method of claim 6 wherein said soap is an alkali metal or alkaline earth metal salt of a rosin acid, a fatty acid, or mixtures of said acids.

1976-09-30

en

1977-11-15

US-86602177-A

Expansion circuit for improved stereo and apparent monaural image ABSTRACT An expander circuit for expanding stereo signals comprises left and right channel variable gain stages whose gain varies in proportion to the amplitude of the control signals fed to the control inputs thereof; and left and right channel expansion control signal providing means for receiving respectively at least portions of the left and right channel signals and feeding expansion control signals to the control inputs of the variable gain stages. These control signals have amplitudes directly proportional to the amplitudes of the signals fed to the inputs of the expansion control signal providing means. The improvement in the circuit is the addition of a signal coupling network for coupling a portion of the left-right channel stereo image producing signal components to the input of the associated expansion control signal providing means and a much smaller porportion thereof to the expansion control signal providing means associated with the other channel. The coupling network responds differently to identical apparent monaural image producing signal components in each channel by feeding a larger proportion thereof to the input of the associated expansion control signal providing means. The coupling network is coupled to points of both amplifier channels which prevent the cross-coupling of a significant portion of the signals in each amplifier channel to the main signal path of the other amplifier channel. BACKGROUND OF THE INVENTION This invention relates to expander circuits in multi-channel amplifier systems used commonly, among other possible reasons, to re-establish the desired dynamic quality of the original signal components altered by compression and peak limiting operations carried out during a recording operation. A stereo sound system drives a left and a right speaker unit with left and right channel signals comprising what can be referred to as apparent monaural image-producing signal components having subsantially identical wave forms (in terms of amplitude and shape) and stereo image-producing signal components having substantially different wave forms. The substantially identical monaural image-producing left and right channel signal components produce an apparent sound source (which can be referred to as an apparent monaural sound image) midway between spaced speaker units. A significant percentage of stereo recordings surprisingly produce such an insufficient apparent monaural sound image that the center area in front of a listener positioned not far from the speaker appears to be acoustically weak. A stereo sound image is produced by these spaced speaker units when substantially different stereo image-producing signal components are fed to these spaced speaker units. In such case, an apparent sound image therefrom appears to be located substantially to one side or the other of the midway point between the speaker units. The ratio between the amplitudes of stereo image-producing signal components reproduced by these spaced speaker units determines the apparent location of the stereo sound image perceived by the listener. If a given stereo image-producing signal component is only reproduced by the left speaker unit, the apparent location of the stereo sound image produced thereby will be to the far left, whereas if the same signal component is also reproduced by the right speaker unit but to a lesser degree (as is commonly the case since complete stereo signal separation is uncommon), the apparent location of the stereo sound image is closer to the midway point between the speaker units in proportion to the degree to which the wave forms of the left and right stereo image-producing signal components approach near equal values. Almost all recordings have their dynamic qualities alterned to some degree by means of compression and peak limiting. Therefore, for the most accurate sound reproduction expansion in the playback system is needed to re-establish the originally recorded signals. In a stereo playback system consisting of left and right channel recorded signals, the addition of an expander alters the stereo sound image produced by left and right speaker units because expansion alters the signal levels of the left and right channels to different degrees, depending on the ratio of the amplitudes of the stereo image producing signals thereof. Thus, for example, if the difference between the loudness of a louder left channel relative to the right channel is 6 db, after expansion of each channel separately the loudness difference could now be 12-20 db, and thus, the left channel would dominate to a greater extent, causing the apparent stereo image location to shift to the left. To avoid this effect and for economy sake, many expanders use only one DC control signal derived from the sum of the left and right signals to control both left and right channels. This sum signal is, by definition, a monaural signal. This method of expansion has two limitations. Firstly, since either channel controls the gain of both, if a signal is very low or absent from one side, the gain can still be raised by the signal of the other channel, thus allowing excessive noise to be heard in the absence of masking program signals. Secondly, if relatively fast time constants are used for the expansion, a reduced sense of stereo image results because the control signal is monaural. My U.S. Pat. No. 3,980,964 describes an expander circuit which reduces distortion, noise and pumping effects while allowing fast accurate following of the program envelope. This results in a greater sense of realism than with slower designs since all aspects of the program,. including fast transients are expanded. This expander circuit, in addition to the presence of a non-frequency selective variable gain stage and a fast acting expansion control signal producing circuit which is preferably an AC to DC converter circuit controlling the same, is provided with a high pass filter which filters out low frequencies, so that the converter circuit produce DC gain control signals reflecting the amplitude of the harmonics of the fundamental frequencies of the audio signal. The commercial form of this circuit incorporated in a stereo amplifier system, before the present invention was conceived, decreased the amount of stereo signal ratio modification caused by the expansion process by cross-coupling a fraction of each DC control signal produced by each AC to DC converter circuit to the control terminal of the variable gain stage of the other channel. Thus, each channel had a small gain control effect on the other channel so that, with this cross-coupling, the stereo image retained a better resemblance to that which would be produced by the original signals. (This stereo image improvement is achieved independently of the presence of the high pass filters described, which are responsible for the distortion, noise and pumping effect reducing the advantages of this circuit). As previously indicated, many stereo recordings fail to produce a significant apparent monaural image to give a more realistic special effect to the listener. In using the cross-coupling of DC control signals to only moderately reduce the stereo separation in the amplifier channels just described to re-establish a more accurate stereo image, many recordings still produce a relatively poor apparent monaural image. While this apparent monaural image could be increased in the circuit just described by increasing the ratio of the cross-coupled DC control signals, such an increased cross-coupling of signals required to establish a significant apparent monaural image usually undesirably reduces the desired stereo separation so that the desired stereo image is not achieved. Accordingly, an object of the present invention is to provide expansion control circuitry which cross-couples expansion control signals in a manner which both improves the stereo and the apparent monaural images produced by the multi-channel amplifier and sound system involved. Another object of the invention is to produce such an improved expansion circuit at a modest cost. SUMMARY OF THE INVENTION The present invention is a substantial improvement over the above described DC control signal mixing technique from the standpoint of simultaneously producing more realistic stereo and monaural images. Also, it produces unexpectedly a three-dimensional effect (i.e. a greater sense of depth as well as width) from only left and right speaker units. These impressive results are achieved by the cross-coupling of the AC input signals to the AC to DC converter circuits previously described (or other expansion control signal providing circuit involved), with and without the presence of said high pass filters, rather than by cross-coupling the DC outputs thereof. Thus, a relatively small fraction, as for example, about 5-20%, and preferably about 10-15%, of only the stereo component of the AC input signal fed to the expansion control signal providing circuit associated with each amplifier channel is fed to the input of the expansion control signal providing circuit associated with the other channel. Also, the monaural component of the AC input signal in each channel is coupled to a greater degree than the stereo component thereof to the input of the associated expansion control signal providing circuit. The stereo image correcting and monaural image enhancing effect produced by the AC cross-coupling described occurs only if the time response of the expansion control signal providing circuit is short. In other words, the DC control signals produced by AC to DC converter circuits used as expansion control signal providing circuits must reflect the instantaneous changes of the amplitudes of the AC input signals. Such fast acting AC to DC converter circuits are disclosed in my U.S. Pat. Nos. 3,980,964 and 3,790,896. Because the signals involved are AC signals, it is possible to provide circuitry which responds differently to the apparent monaural image-producing signal components and the stereo image-producing signal components, as described. In accordance with the preferred form of the invention, the circuit for accomplishing this result includes a voltage-divider impedance network which interconnects corresponding low impedance points of the two amplifier channels involved. These low impedance points are, most advantageously, the emitter portion of emitter-follower circuits which normally have low impedance points at the emitters of the transistors thereof. The voltage divider impedance network preferably comprises identical outer impedance sections coupled between the low impedance points and the input terminals to the expansion control signal providing circuits, such as the inputs to the high pass filters or AC to DC circuits referred to, and a center impedance section of an impedance value many times greater than the outer impedance sections and interconnecting the input terminals of the expansion control signal providing circuits. It can be shown that when signals having wave forms with substantially identical amplitude, phase and shape (i.e. monaural image-producing signals) are present at the outermost terminals of this network, no current flows beween these terminals. The center impedance section of the network then acts like an almost infinite impedance isolating the outer sections of the network and providing a different voltage division along the network for stereo and monaural signals to that a higher proportion of the identical monaural signals appearing at each low impedance terminal referred to is coupled to the input of the associated expansion control signal providing circuit than for stereo signals present at these terminals. Also, the low impedance points to which the ends of the impedance network are connected result in a voltage division along the network for stereo signals which produces a substantially zero voltage (with respect to chassis ground) at these points, so that the network de-couples the stereo signal in each channel from that portion of the other channel coupled to the adjacent end of the impedance network, such as the input to the associated variable gain stage. DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of a preferred form of the expansion circuit of the invention; FIG. 2 shows the degree of gain expansion achieved by the variable gain stages shown in FIG. 1 from the various expansion control signals indicated; and FIG. 3 is an exemplary circuit diagram of the emitter-follower circuits and the associated voltage divider network interconnecting the emitter circuit outputs and inputs of the high pass filters shown in block form in FIG. 1. DESCRIPTION OF EXEMPLARY EMBODIMENT OF THE INVENTION Referring now more particularly to the exemplary block diagram of FIG. 1, shown therein are signal sources 2-2' for left and right amplifier channels 3-3' of a stereo amplifier system. These signal sources may be FM signal detector circuits, disc record pick-up units, tape pick-up units, or the like, which produce signals having what has been previously referred to as apparent monaural image-producing signal components, and stereo image-producing signal components. As previously indicated, apparent monaural image-producing signal components have wave forms which have substantially similar or identical amplitude and shape, (and desirably also the same phase) and stereo image-producing signal components have wave forms which have substantially dissimilar amplitude and/or shape. The signal sources 2-2' are respectivey coupled directly or indirectly through amplifiers (not shown) to circuits 4-4' which provide a very low impedance between their output terminals 4a-4a' and a reference point, like chassis ground, to which their terminals 4b-4b' are connected. In the exemplary circuit illustrated, the circuits 4-4' are emitter-follower circuits where the terminals 4a-4a' are coupled to the emitter portions of the transistors therein, as shown in FIG. 3 to be described. The output terminals 4a-4a' of the emitter-follower circuits 4-4' are shown connected respectively to the input termials 6a-6a' of non-frequency selective variable gain stages 6-6'. The variable gain stages 6-6' can take a variety of forms. Thus, they can each be a variable impedance network, like the network 2 shown in FIG. 9 of my U.S. Pat. No. 3,980,964 (which has a variable gain less than 1), or more preferably can be a more conventional variable gain amplifier (which has a variable gain more than 1). In either event, the variable gain stages 6-6' act as expansion circuits where the gain thereof is directly proportional to the amplitude of expansion control signals fed to the input control terminals 6b-6b' thereof, as illustrated by FIG. 2. In the present exemplary circuit in FIG. 1, these expansion control signals are DC voltages fed thereto from expansion control signal providing circuits 7-7' which, most preferably, include high pass filters 10-10' and AC to DC converter circuits 12-12' which respectively may be like the high pass filter circuits3-3' and AC to DC converter circuits 4-4' shown in FIGS. 5 and 6 of my U.S. Pat. No. 3,980,964. However, if one wishes not to utilize the advantages of the invention of this patent, the high pass filters 10-10' may be omitted. Where the variable gain stages 6-6' are of the type shown in FIG. 9 of this patent, the AC to DC converter circuits 12-12' would not be needed and the expansion control signal producing circuits 7-7' would, in effect, be the signal cross-coupling circuit 5 to be described, which interconnects the low impedance terminals 4a-4a'. The output terminals 6c-6c' of the variable gain stages 6-6' may be coupled through power amplifiers to left and right hand speaker units 13--13' which would normally be placed respectively at left front and right front portions of a room in front of the seating area of the listener or listeners involved. In a four-channel amplifier system, the circuit shown in FIG. 1 could be duplicated for left rear and right rear speaker units. In accordance with the present invention, the cross-coupling circuit 5 provides different degrees of coupling and cross-coupling of the monaural and stereo signals from each channel to the inputs of the expansion control signal providing circuits. Thus, identical monaural signals in the amplifier channels are, most advantageously, coupled through this circuit 5 to the input terminals of the associated expansion control signal providing circuits 7-7' to a greater degree than the stereo signals are coupled thereto, and a portion of the stereo signal components in each amplifier channel are cross-coupled to the input terminal of the expansion control signal providing circuit associated with the other channel. For example, from about 5 to 20%, and more preferably from about 12 to 15%, of the stereo image-producing signal components coupled to the input terminal of expansion control signal providing circuit 7 or 7' associated with one amplifier channel is cross-coupled to the input terminal of the expansion control signal providing circuit associated with the other amplifier channel. Also, the stereo signals in each amplifier channel are de-coupled from the other amplifier channel because of the low impedance of the emitter-follower output terminals 4a-4a'. As previously indicated, the AC to DC converter circuits 12-12' must, for the advantages of the invention to apply, respond quickly to changes in amplitude of the input signal components, as is the case also with the circuit shown in my U.S. Pat. No. 3,980,964. (FIG. 8 of this patent and the description thereof indicates a desired speed of response of the output of the AC to DC converter circuits resulting from a relatively long duration audio signal of fixed amplitude suddenly applied to and suddenly removed from the AC to DC converter circuits.) While the cross-coupling circuit 5 now to be described may have other circuit configurations for producing the functions just described, it is most preferably a voltage divider network comprising identical outer resistors 5a-5a' respectively connected between the low impedance emitter-follower circuit terminals 4a-4a' and the input terminals 10a-10a' of the high pass filters 10-10' (where the high pass filters are utilized) or the input terminals of the AC to DC converter circuits 12-12' in the absence of said filters. A central cross-coupling resistor 5b is provided of a substantially higher resistance value than the resistors 4a-4a'. For example, in one commercial form of the circuit, the resistors 4a-4a' were 15,000 ohms and the cross-coupling resistor was 82,000 ohms. However, the actual values and effects of these resistors depend upon the particular effective circuit input impedances of the circuits to which the various points of the voltage divider network are connected. It was found that such a voltage divider network responds differently to the monaural and stereo signals as described. In order to explain the operation of the voltage divider network, reference should now be made to FIG. 3 which shows exemplary circuits for the emitter follower circuits 4-4' and the equivalent input circuits for the variable gain stages 6-6' and the high pass filters 10-10'. As there shown, the emitter follower circuits 4-4' respectively include NPN transistors 20-20' whose emitters 20e-20e' are connected through resistors 22-22' to ground. Capacitors 24-24' connect the emitters 20e-20e' respectively to the outer ends of voltage divider network 5 and also to the ungrounded ends of impedances 26-26' representing the equivalent input impedances of the variable gain stages 6-6'. The upper and lower ends respectively of cross-coupling resistor 5b of the voltage divider network 5 are shown respectively coupled through capacitors 28-28' to impedances 30-30' representing the equivalent input impedances of the high pass filter circuits 10-10'. Exemplary values of the various impedances shown in FIG. 3 are as follows: resistors 5a and 5a'--15,000 ohms resistor 5b--82,000 ohms resistors 22 and 22'--15,000 ohms resistors 26 and 26'--100,000 ohms resistors 30 and 30'--390,000 ohms capacitors 24 and 24'--10 microfarads capacitors 28 and 28'--0.0047 microfarads For identical signals appearing simultaneously at the outer ends of resistors 5a-5a', which would be the case with monaural signals, there can obviously be no flow of current between these points since there is no potential difference therebetween when, as is usually the case with monaural signals in the amplifier channels, they are approximately in phase with one another. In such case, no current from these monaural signals will flow in the cross-coupling resistor 5b which makes this resistor act like an infinite impedance connected to chassis ground. Accordingly, for given monaural signals at the output terminal 4a or 4a' of the emitter follower circuit 4 or 4', the magnitude of the signal coupled across the equivalent input impedance 26 or 26' of the associated variable gain stage 6 or 6' is determined by the following equation: ##EQU1## where AM equals the amplitude of the monaural signal involved. (This equation assumes that the effective infinite impedance to ground referred to, shunted by the 390,000 ohms resistor 30 connected to chassis ground, acts like a single 390,000 resistor replacing the same.) For stereo signals which are dissimilar signals in the two channels, the voltages or currents produced by the same are coupled to a lesser degree to the input of the associated high pass filter and are cross-coupled to the input of the high pass filter associated with the other channel to only a modest degree as, for example, with a cross-coupling ratio falling in the range of about 5 to 20% and, preferably, in the range of about 10 to 15%. Since stereo signals present at the opposite ends of the voltage divider resistors 5a-5a' are substantially dissimilar signals, current will flow into the cross-coupling resistor 5b as determined by its value and that of resistor 5a or 5b. Therefore, the voltage divider network does not act to de-couple these signals from the various points of the voltage divider network, and so there will be at the input of each high pass filter signals originating both from the output terminal of the emitter follower of the associated channel and the output terminal of the emitter follower of the other channel. The stereo signal voltage Ecc cross-coupled from the input of high pass filter 10 or 10' to the input of the other of same through the cross-coupling resistor 5b and resistor 5a or 5a' is determined by the following equation: ##EQU2## where Es equals the stereo signal at the input of filter 10 or 10'. The stereo signal voltage Ec directly coupled from the output of emitter follower circuit 4a or 4a' to the ungrounded end of the equivalent input impedance 30 or 30' of the associated high pass filter is determined by the following equation: ##EQU3## where Es' equals the stereo signal at terminal 4a or 4a'. The 77,700 ohms is the net resistance of the resistor 30 or 30' in parallel with resistors 5b and 5a or 5a', assuming further that the emitter circuit resistance is of such a small value (typically under 300 ohms) in comparison to 15,000 ohms that it acts like an effective ground. This effective ground acts to prevent coupling of stereo signals between the inputs of the variable gain stages. Thus, the equation for the stereo voltage Ecc' coupled between one end of the voltage divider network 5 and the other end thereof is as follows: ##EQU4## where Es equals the stereo signal at terminal 4a or 4a'. It can thus be seen that the amount of the monaural signals coupled from the output terminal 4a or 4a' to the input of the associated high pass filter 10 or 10' is greater than the amount of the stereo signals coupled to the input of the associated high pass filter 10 or 10', so that the DC control signal developed by the AC to DC converter circuit associated therewith will be affected to a higher degree by a monaural signal of a given amplitude than by a stereo signal of the same amplitude. Also, a small but significant portion of the stereo signal at the input of high pass filter 10 or 10' originating in the associated channel is cross-coupled to the input of the other filter, but practically no portion thereof is coupled to the input of the variable gain stage of the non-associated channel. The voltage divider network 5 thus produces a desired reduced amount of stereo signal separation in the amplifier channels together with a desired increase in the monaural signals therein to eliminate a weak sound image midway between the speaker units. It should be understood that numerous modifications may be made in the most preferred form of the invention shown in the drawings without deviating from the broader aspects of the invention. For example, while the cross-coupling of stereo signals between the inputs of the variable gain stages is best achieved by use of a voltage divider network 5 coupled between the emitter portions of emitter-follower circuits 4-4' driving variable gain stages 6-6', isolation between the inputs of the variable gain stages could be achieved by separating the inputs of the variable gain stages from the network 5 altogether as, for example, by use of separate emitter-follower circuits in each channel (not shown). Also, the signals feeding the voltage divider network 5 less desirably could be obtained completely from the output of the variable gain stages, or partially therefrom as by voltage adding or subtracting feedback connections between the output of variable gain stages 6-6' and the inputs to high pass filters 10-10'. I claim: 1. An expander circuit for a multi-channel amplifier system including left and right amplifier channels respectively driving left and right speaker units, each channel including a variable gain stage therein whose gain varies in direct proportion to the amplitude of control signals fed to control signal input terminals thereof, said expander circuit comprising left and right expansion control signal providing means having inputs for receiving respectively left and right amplifier channel signals and output terminals connected respectively to said control signal input terminals of said variable gain stages of said left and right amplifier channels, at which output terminals the expansion control signals respectively appear in proportion to the amplitudes of the sum of the signal components fed to said inputs, the improvement comprising signal coupling circuit means for coupling the signals of said amplifier channels to the input terminals of said expansion control signal providing means, said signal coupling circuit means including respective means associated with said channels for respectively coupling at least a portion of the signals therein having substantially different waveforms to the input terminals of the expansion control signal providing means of the associated channels and for cross-coupling a substantially lesser proportion of the same to the input terminal of the expansion control signal providing means of the non-associated channels, whereby the original signal separation of the two amplifier channels is substantially maintained in spite of said expansion. 2. The expander circuit of claim 1 wherein there is provided isolating means for preventing said cross-coupled signals fed to the latter expansion control signal providing means from being also cross-coupled to the input of the variable gain stage of the latter amplifier channel. 3. The expander circuit of claim 1 wherein the ratio of the signals having substantially different waveforms in said respective channels cross-coupled to the input terminals of the expansion control signal providing means of the non-associated channels to that coupled to the input terminal of the expansion signal providing means of the associated channels is in the range of from about 5 to 20%. 4. The expander circuit of claim 3 wherein said ratio is in the range of from about 10 to 15%. 5. The expander circuit of claim 1 wherein said signals of substantially different waveform are coupled to said expansion control signal providing means from variable gain stage driving points of said amplifier channels which prevent cross-coupling of signals in each channel to the input of the variable gain stage of the other channel. 6. The expander circuit of claim 5 wherein said points are the emitter connected portions of emitter-follower circuits. 7. The expander circuit of claim 1 wherein said coupling circuit means couples a greater percentage of substantially identical signals in said respective amplifier channels to the inputs of the expansion control signal providing means of the associated channels than for said signals of substantially different waveforms, to enhance an apparent monaural image produced between said left and right speaker units. 8. The expander circuit of claim 1 wherein said coupling circuit means comprises a voltage divider network connected between relatively low impedance points of said amplifier channels, said voltage divider network comprising three series connected sections, the outer sections being connected between said low impedance points of said amplifier channels and the respective input terminals of said expansion control signal providing means, and a center section interconnecting said input terminals. 9. The expander circuit of claim 8 wherein said center section of said voltage divider network has an impedance value many times greater than the outer section thereof. 10. The expander circuit of claim 9 wherein the equivalent input impedances of said expansion control signal providing means are of a value many times greater than the value of the impedances of said center section of said voltage divider network. 11. The expander circuit of claim 8 wherein said low impedance points are in the emitter connector portions of emitter-follower circuits. 12. The expander circuit of claim 8 wherein said expander control signal providing means includes an AC to DC converter circuit which produces DC signals closely and substantially instantaneously following the change in amplitude of the signals fed from said amplifier channels to the inputs thereof, said variable gain stages being responsive to the DC control signals fed to the control signal input terminals thereof. 13. In a circuit for expanding stereo input signals in left and right stereo amplifier channels and including stereo input signal receiving left and right channel variable gain means, each of which has a gain proportional to the amplitude of a control signal fed to a control input thereof, and a left and right channel expansion control signal providing means responsive respectively to the input signals in said left and right channels for producing control signals respectively fed to the control inputs of the associated left and right variable gain means, said control signals having amplitudes directly proportional to the amplitude of the sum of the proportion of the input signals fed to the associated expansion control signal providing means, the improvement comprising coupling means for coupling a portion of each input signal component fed to the input of each associated expansion control signal providing means to the input of the other expansion control signal providing means, and isolating means for preventing the cross-coupling of the input signals from each channel from the variable gain means of the associated channel to the input of the variable gain means of the other channel. 14. The circuit of claim 13 wherein said coupling means is a voltage divider network extending between corresponding low impedance points of said amplifier channels and having similar impedance value outer sections respectively coupled between said low impedance points and the inputs of said expansion control signal providing means and a center section interconnecting said inputs and being many times larger in impedance value than said outer sections of the voltage divider network. 15. In a circuit for expanding stereo input signals in left and right stereo amplifier channels and including stereo and monaural signal components, left and right channel stereo signal receiving variable gain means each responsive to the amplitude of control signals fed to the control input thereof by varying the gain thereof in accordance with the amplitude of the control signals fed thereto, and left and right channel expansion control signal providing means responsive respectively to the input signals in said left and right channels for producing signals respectively fed to the control inputs of the associated left and right variable gain means, said control signals having amplitudes directly proportional to the amplitude of the sum of the proportion of the input signals fed to the associated expansion control signal providing means, the improvement comprising: coupling circuit means for coupling the monaural and stereo input signal components in said channels to the left and right expansion control signal providing means and comprising means for coupling the stereo signal components of the input signal in each channel to the inputs of both of said expansion control signal producing means, the degree of such coupling being to a greater degree to the input of the expansion control signal producing means of the associated channel than to the input of the expansion control signal providing means associated with the other channel, and for coupling to a greater degree than the stereo signal components in each channel the monaural signal components in each channel to the input of the associated expansion control signal providing means, and isolation means for preventing the cross-coupling of the stereo signal components in each of the channels to the input of the variable gain means associated with the other channel. 16. The circuit of claim 15 wherein said expansion control signal providing means of each channel includes an AC to DC converter circuit for generating a DC expansion control signal from the sum of the signal components fed thereto. 17. The circuit of claim 15 wherein said isolation means is an emitter-follower circuit. 18. The circuit of claim 15 wherein said expansion control signal providing means is a circuit which responds substantially instantaneously to changes in amplitude of the input signals thereto.

1977-12-30

en

1979-07-24

US-35707989-A

Saw belt roller ABSTRACT Saw belt roller, in particular for horizontal belt saws, in which the peripheral or running surface (3) carrying the saw belt consists of a wear-resistant, hard, metal material. The metal joining piece (6) between the running surface (3) and the hub (5) of the saw belt roller (1) is interrupted by the insertion of a noise-damping, in particular viscoelastic, material (7), which is preferably selected from concrete polymer, silicone, rubber, in particular hard rubber, or similar elastomeric material. The invention relates to a saw belt roller, in particular for horizontal belt saws, in which the peripheral or running surface carrying the saw belt consists of a wear-resistant, hard, in particular metal, material. It is generally known that, in belt saws, the belt saw blade produces a shrill screeching noise when going around the saw belt rollers, in particular during the cutting process, the cause of this primarily being the fact that the saw belt vibrates in the transverse and longitudinal direction during the cutting process. In addition to the shrill screeching noise, which is very disturbing in the surrounding area, the vibrations of the belt saw blade also have a damaging effect on the accuracy of cutting and the cutting performance as well as on the useful life of the belt saw blade. Furthermore, the vibrating belt saw blade thoroughly spatters cutting oil, forming a mist of cutting oil. Finally, the vibrations of the belt saw blade result in a rough cutting surface on the cut workpiece and in a blade clearance which is broader at the beginning of cutting than the blade clearance which later develops and which is defined by the shape of the saw blade. In the case of more violent vibrations, it is no longer possible to achieve an accurate, straight cut. To solve the problems mentioned, it is proposed, on the one hand, to provide the running surface of the saw belt roller with a contoured coating of elastic material (U.S. Pat. No. 3,363,495), with the running surface coating being formed, in accordance with DE No. C-2,740,212, by O-rings which lie spaced laterally from one another in dovetail-shaped peripheral grooves in the saw belt roller. However, this construction has the disadvantage that it is extremely susceptible to wear, so that the contoured coating of elastic material must be replaced after an extremely short operating time. On the other hand, to solve the problem mentioned, it is proposed to alter the voltage and/or the free length of the belt saw blade periodically during operation of the belt saw (DE No. A-3,040,829). However, the measures required for construction of this solution are evidently complicated. To this end, one of the two saw belt rollers must be provided with a periodically effective tension drive by means of which the two saw belt rollers can periodically be moved closer together and further apart. Instead, a tension roller which is mounted so as to slide transversely with respect to the belt saw blade and which is periodically pressed against the belt saw blade by an adjusting drive can be arranged between the two saw belt rollers. This last-mentioned construction is the current state of the art. Independently of this, however, use is still also made today of fairly large cover hoods and cover plates in order to limit the emission of noise. Preferably, such enclosures of the belt saw blade and saw belt rollers are lined on the inside with sound-absorbent material. These measures are not suitable for the elimination of the "evil" of excessive noise levels or unacceptably high vibrations of the belt saw blade; however, they help to moderate the said evil. SUMMARY OF THE PRESENT INVENTION The present invention is based on the object of avoiding the stated disadvantages of the known constructions and of designing a saw belt roller such that low-noise, precise running of the belt saw blade is achieved while maintaining the high level of wear resistance. Between the running surface of the saw belt roller, which is formed of material having a hard surface for reasons of wear, and the hub of the saw belt roller in accordance with a significant feature of the invention, a continuous material joining piece, in particular a metal joining piece, is interrupted, in particular by means of a noise-damping material. By using materials including concrete polymer, silicone, rubber, in particular hard rubber, or similar elastomeric material as the noise-and vibration-damping material, the strength and stability of the saw belt roller is not impaired. At the same time, however, a higher level of noise- and vibration-damping is achieved. A particularly advantageous embodiment of construction includes a running surface supported via elastic strips or the like, in particular rings of rubber or the like, on the wheel disc defining the metal joining piece between the running surface and the hub. The running surface is formed from the outer peripheral surface of the running ring which has an approximately trapezoidal cross-section and is support by two rings of rubber or the like lying against the two oblique surfaces opposite the wheel disc forming the joining piece between the running surface and the hub. The embodiment is distinguished both by a high level of noise- and vibration-damping and a high truth of running, so that a greater pre-tensioning of the belt saw blade is possible. In addition, but independently thereof, the roller includes a sandwich configuration and has at least one elastically resilient, in particular viscoelastic, intermediate layer extending transversely to the central axis and can also serve to damp noise and vibration. Accordingly, the noise-damping material is not stretched in an annular manner around the axis of the saw belt roller but transversely to it. Three embodiments of a saw belt roller constructed in accordance with the invention are described in more detail below with reference to the attached drawing, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a first embodiment of a saw belt roller constructed in accordance with the invention, in diagrammatic partial section; FIG. 2 shows a second embodiment of a saw belt roller constructed in accordance with the invention, in diagrammatic partial section; and FIG. 3 shows a third embodiment of a saw belt roller constructed in accordance with the invention, in diagrammatic partial section. DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The saw belt roller 1 shown in partial section in FIG. 1 consists of an outer ring 2, the peripheral surface 3 of which represents the running surface for the belt saw blade (not shown). On one side, in FIG. 1 the left side, the running surface 3 is limited by a stop collar 4. The hub of the saw belt roller is given the reference numeral 5. The metal joining piece 6 between the hub 5 and the outer peripheral ring 2 or the running surface 3 is interrupted by a layer 7 extending over the periphery, of noise-damping material, in particular hard rubber, silicone or the like. It should be mentioned at this point that it is possible to provide more than one intermediate layer 7 between the running surface 3 and the hub 5. The geometric axis of the saw belt roller 1 is given the reference numeral 8. As already specified at the outset, the running surface ring 2 consists of a wear-resistant material, preferably steel, ceramic or the like. The hub 5 and joining piece 6 can be produced from a less wear-resistant material, preferably also a metal material. The embodiment of FIG. 2 differs from that of FIG. 1 in that the entire joining piece between the running surface ring 2 and the hub 5 is filled with a noise-damping material 9, in particular preferably concrete polymer. In the embodiment of FIG. 3, the running surface 3 is formed from the outer peripheral surface of a running ring 2 which has an approximately trapezoidal cross-section and is supported, by two rings 12, 13 of rubber or the like lying against the two oblique surfaces 10, 11, on the wheel body or on the metal joining piece 6 between the running surface ring 2 and the hub (not shown). The running surface ring 2 shown in FIG. 3, too, has a stop collar 4 for the belt saw blade, which is given the reference numeral 14. The cutting teeth of the belt saw blade 14 are given the reference numeral 15. The running surface ring 2 of FIG. 3 is supported, both radially and axially, within a peripheral groove formed on the wheel body or on the wheel disc 6 via the rubber rings 12, 13, one lateral limit, in FIG. 3 the left-hand limit, of the peripheral groove 16 being produced by a retaining ring 17 screwed onto the wheel disc 6. The screw connection between the retaining ring 17 and the wheel disc 6 is indicated in FIG. 3 by the fastening screw 18. In the assembled state, the rings 12, 13 of rubber or the like lie in the two corners of the peripheral groove 16. Preferably, O-rings are used for this, the cross-section of which is deformed to be approximately triangular in the assembled state, corresponding to FIG. 3. As specified above, the saw belt roller 1 can also be produced in a sandwich configuration and have at least one elastically resilient, in particular viscoelastic (silicone) intermediate layer which extends transversely to the central axis 8 of the saw belt roller 1. This embodiment is not shown in the drawing. Furthermore, the saw belt roller according to the invention is also suitable for vertical belt saws. All the features disclosed in the documents are claimed as essential to the invention, insofar as they are novel individually or in combination with respect to the state of the art. I claim: 1. A saw belt roller, in particular for horizontal belt saws and particular for carrying a saw belt, comprising a running surface member (3) consisting of a wear-resistant, hard material, a hub (5), and a continuous member (6) located between the running surface member (3) and the hub (5), said continuous member including a resilient and elastic connecting element of a non-metallic material and ( 7; 9; 12, 13) forming a totally non-metallic and sole connection between said hub and running surface member and thereby damping noise and vibration created by a belt saw running on said running surface member. 2. The saw belt roller according to claim 1, wherein said vibration-damping material is selected from concrete polymer, silicone, rubber, hard rubber, and similar elastomeric material. 3. A saw belt roller, in particular for horizontal belt saws and particular for carrying a saw belt, comprising a wheel disc consisting of a wear resistant and hard material and having a hub (5), an outer peripheral running ring (2) having an approximately trapezoidal cross-section aligned with said wheel disc, said running ring including an outer running surface and two inner oblique surfaces, and two rings (12, 13) of a resilient elastic material and located one each between one of said two oblique surfaces (10, 11) of the running ring and the wheel disc.

1989-05-25

en

1991-01-01

US-74603485-A

Method of approach in area cutting ABSTRACT A method of approach in area cutting includes giving in advance an angle θ between a workpiece plane (WPL) and a straight line (SL) connecting an approach starting point (P A ) and a cutting starting point (P i ), and a distance dz between the approach starting point (P A ) and the cutting starting point (P i ) in a direction perpendicular to the workpiece plane. Coordinate values of the approach starting point (P A ) are calculated using the angle θ and the distance dz in such a manner that a projection (SL&#39;) of the straight line (SL) on the workpiece plane (WPL) is brought into orientation with a direction of a normal line at the cutting starting point (P i ) on a curve (OLC) of the external shape. A tool (TL) is positioned at the approach starting point (P A ) in a rapid-traverse mode, and the tool is subsequently moved to the cutting starting point (P i ) in a cutting-feed mode. Thereafter, cutting is started. BACKGROUND OF THE INVENTION This invention relates to a method of approach in area cutting for cutting the interior of an area surrounded by the curve of an external shape. More particularly, the invention relates to a method of approach so adapted that in moving a tool toward a cutting starting point, the tool is moved obliquely with respect to a workpiece, so that the tool will cut into the workpiece without fail. Forms of numerically controlled machining include cutting, in which the interior of an area bounded by the curve of an external shape is hollowed out down to a predetermined depth, and die milling in which the interior of an area is die milled. In such cutting of the interior of an area, as shown in FIG. 1, the process includes entering the curve OLC of an external shape of an area AR, cutting direction (direction of arrow A), cut-in direction (direction of arrow B), and cut-in pitch P; creating a cutting path PTi (i=1, 2, . . . ) on the basis of the entered data; performing cutting my moving a tool TL in the cutting direction along the created cutting path PTi ; creating the next cutting path PTi+1 by effecting a shift corresponding to the aforementioned pitch in the cut-in direction (direction of arrow B) after the completion of cutting along the above-mentioned cutting path; performing cutting by moving the tool in the cutting direction (direction of arrow A) along the next cutting path; and thereafter repeating this unidirectional cutting to cut the area AR. It should be noted that, for each cutting path PTi, two points Pi, Qi where the curve OLC of the external shape is intersected by a straight line SLi determined by the cut-in direction and pitch are specified as machining starting and end points, respectively. A tool referred to as an end mill is used as the tool TL. As shown in FIG. 2, an end mill includes a bottom surface having cutting edges BT1, BT2, and a cutter side having a cutting edge BT3. Longitudinal cutting is performed by the cutting edges BT1, BT2, and transverse cutting is carried out by the cutting edge BT3. Little cutting force is applied in the longitudinal direction, and great cutting force is applied in the transverse direction. The workpiece is a solid material prior to the cutting of an area. Moreover, the center position CP (see FIG. 2) of the bottom surface of tool (end mill) TL does not rotate (i.e., is stationary), even when the tool TL is rotated. Consequently, when the initial cut is to be made, even though the tool TL is moved for cutting feed from an approach starting point Pa, which is located directly above the cutting starting point Pi, as shown in FIG. 3, toward the cutting starting point Pi while being rotated, the tool TL slides along the surface of the workpiece WK rather than cutting into the workpiece or, even if it does cut into the workpiece, it fails to do so smoothly and results in a machining error. Accordingly, a hole is bored in advance at the initial cutting starting point Pi so that the tool TL will be sure to cut into the workpiece WK when the approack is made. However, this method is disadvantageous in that it necessitates the hole boring step prior to the cutting of the area and prolongs machining time. SUMMARY OF THE INVENTION An object of the present invention is to provide a method of approach in area cutting, whereby a tool will cut into a workpiece without fail when making an approach, even at initial cutting. Another object of the present invention is to provide a method of approach in area cutting, whereby a tool will cut into a workpiece without fail when making an approach, even if a hole or the like is not bored beforehand at the cutting starting point. The present invention provides a method of approach in area cutting for cutting the interior of an area bounded by the curve of an external shape. The method includes giving in advance an angle θ between a workpiece plane and a straight line connecting an approach starting point and a cutting starting point, and a distance dz between the approach starting point and the cutting starting point in a direction perpendicular to the workpiece plane; calculating coordinate values of the approach starting point using the angle θ and the distance dz in such a manner that a projection of the straight line on the workpiece plane is brought into coincidence with a direction of a normal line at the cutting starting point on the curve of the external shape; positioning the tool at the approach starting point in a rapid-traverse mode; subsequently moving the tool to the cutting starting point in a cutting-feed mode; and thereafter starting cutting. According to the approach method of the present invention, the tool TL is moved toward the cutting straight point obliquely with respect to the workpiece WK. As a result, even though the workpiece is a solid member when the approach is made, the tool is capable of cutting into the workpiece smoothly without fail. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for describing the cutting of an area; FIG. 2 is a view for describing a tool; FIG. 3 is a diagram for describing the shortcomings of the conventional method; FIGS. 4(A) and 4(B) are diagrams for describing a method of approach in area cutting according to the present invention; FIG. 5 is a block diagram of an embodiment of the present invention; and FIGS. 6(A) and 6(B) are flowchart of processing according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 4 is a diagram for describing the method of the present invention, in which FIG. 4(A) is a sectional view and FIG. 4(B) a plan view. The method of approach of the present invention includes giving in advance an angle θ between a workpiece plane WPL and a straight line SL connecting an approach starting point PA and a cutting starting point Pi. Also given in advance is a distance dz between the approach starting point PA and the cutting starting point Pi in a direction perpendicular to the workpiece plane. The method further includes calculating coordinate values of the approach starting point PA using the angle θ and the distance dz, in such a manner that a projection SL' [see FIG. 4(B)] of the straight line SL on the workpiece plane WPL, is brought into coincidence with a direction of a normal line at the cutting starting point Pi on the curve OLC of the external shape; positioning the tool TL at the approach starting point PA in a rapid-traverse mode; subsequently moving the tool to the cutting starting point Pi in a cutting-feed mode; and thereafter starting cutting. FIG. 5 is a block diagram of an embodiment of the present invention, and FIG. 6 is a flowchart of processing. (1) When a cycle start button on an operator's panel 101 is pressed, a processor 102 causes an NC data reader 103 to read one block of NC data from an NC tape 104. The NC tape 104 stores area cutting data in addition to ordinary path data, G-function instruction data and M-, S- and T-function instruction data. Stored at the end of the NC program is an M code (M02) indicating program end. Placed at the beginning of the area cutting data is an area cutting command indicating that the data which follow are the area cutting data. Placed at the end of the area cutting data is a code indicative of the end of the area cutting data. (2) The processor 102, placed under the control of a control program stored in a ROM 105, checks whether an item of the read NC data is "M02", which is indicative of program end. If the item of data is "M02", numerical control processing is ended. (3) If the item of read NC data is not "M02" indicative of program end, then the processor 102 checks whether the item of NC data is the area cutting command. (4) If the item of NC is not the area cutting command, the processor 102 executes ordinary numerical control processing. By way of example, if an item of NC data is an M-, S- or T-function instruction, the processor delivers the data to a machine tool 107 via a data input/output unit 106 functioning as an interface circuit between an NC unit and the machine. In response to a completion signal received as an answer from the machine tool 107 indicating completion of processing for the M-, S- or T-function instruction, the processor causes the NC data reader 103 to read the next item of NC data. If the item of NC data is path data, then the following path control processing is executed. Specifically, the processor obtains incremental values Xi, Yi, Zi along the respective axes, and obtains velocity components Fx, Fy, Fz along the respective axes from equations ##EQU1## based on the incremental values and a commanded feed velocity F. Thereafter, the processor obtains travelling quantities ΔX, ΔY, ΔZ, which are to be traversed along the respective axes in a predetermined period of time ΔT seconds (=8 msec), from equations ΔX=F.sub.x ΔT (2a) ΔY=F.sub.y ΔT (2b) ΔZ=F.sub.z ΔT (2c) The processor delivers ΔX, ΔY, ΔZ to a pulse distributor 108 every ΔT sec. On the basis of the input data (ΔX, ΔY, ΔZ), the pulse distributor 108 performs a simultaneous three-axis pulse distribution calculation to generate distributed pulses XP, YP, ZP. The distributed pulses are applied as inputs to servo circuits 109X, 109Y, 109Z for the respective axes to rotate servomotors 110X, 110Y, 110Z. The tool is thus moved relative to the workpiece toward a target position. The procesor 102, in accordance with the following formulae, updates the present position X1, Ya Za along the respective axes every ΔT sec, Xa, Ya, Za having been stored in a working memory 112: X.sub.a ±ΔX→X.sub.a (3a) Y.sub.a ±ΔY→Y.sub.a (3b) Z.sub.a ±ΔZ→Z.sub.a (3c) The sign depends upon the direction of movement. Similarly, in accordance with the following formulae, the processor 102 updates remaining traveling distances Xr, Yr, Zr (the initial values of which are the incremental values Xi, Yi, Zi, respectively) every ΔT sec, Xr, Yr, Zr having been stored in the working memory 112: X.sub.r -ΔX→X.sub.r (4a) Y.sub.r -ΔY→Y.sub.r (4b) Z.sub.r -ΔZ→Z.sub.r (4c) When the following condition is established: X.sub.r =Y.sub.r =Z.sub.r =0 (5) the processor 102 then causes the NC data reader 103 to read the next item of NC data. (5) If the item of NC data is found to be the area cutting command at the decision step (3), the processor 102 causes the NC data reader 103 to read the area cutting data and store the data in a RAM 111 until the code indicating the end of the area cutting data is read out. It should be noted that the area cutting data are (1) data indicating the curve of the external shape of the area, (2) cutting direction data (data indicating that the tool is to be moved in the direction of the arrow A or in the direction of an arrow D in FIG. 1), (3) cut-in direction data (data indicating that the tool is to be moved in the direction of the arrow B or in the direction of an arrow C in FIG. 1), (4) pitch P in the cut-in direction, (5) cutting velocity, (6) cut-in direction starting point, (7) cut-in direction end point, (8) position (Zap) of approach plane APL [see FIG. 4(A)], (9) the angle θ between the workpiece plane and a straight line connecting the approach starting point PA and cutting starting point Pi, (10) the distance dz between the approach starting point PA and the cutting starting point Pi in a direction perpendicular to the workpiece plane, etc. (6) When the area cutting data are finished being read, the processor 102 performs the operation 1→i on i, which is stored in the working memory 112. Hereafter we will assume that the cutting direction is the +X direction, that the cut-in direction is the +Y direction, that the approach plane is parallel to the XY plane at a height Zap, that the cut-in direction starting point is Ys, and that the cut-in direction end point is Ye. (7) Next, the processor 102 performs processing for specifying an i-th cutting path PTi. Specifically, the processor 102 creates the straight line SLi (see FIG. 1). The straight line SLi is expressed by the equation y=Y.sub.s +P·i (6) (8) Thereafter, the processor 102 calculates the coordinate values of the points Pi, Qi where the straight line SLi intersects the curve OLC of the external shape of the area. Of the intersection points Pi, Qi, the intersection point Pi, which has the smaller X coordinate value, is treated as the cutting starting point of the i-th cutting path PTi, and the intersection point Qi, which has the larger X coordinate value, is treated as the cutting end point of the i-th cutting path PTi. (9) After the coordinate values (Xio, Yio, Zio) of the cutting starting point Pi are calculated in the above manner, the processor 102 calculates the coordinate values (XA, YA, ZA) of the approach starting point PA by using the coordinate values of the cutting starting point Pi, the angle θ and the distance dz. More specifically, first the processor finds the normal line to the external shape curve OLC [see FIG. 4(B)] at the cutting starting point Pi. The normal line lies on the XY plane and is obtained in the following manner: If two points Pi1, Pi2 lying on the external shape curve OLC on either side of the cutting starting point Pi are found and a circle passing through these three points Pi1, Pi, Pi2 is obtained, then the straight line connecting the center of this circle and the cutting starting point Pi will be the normal line. Accordingly, the normal line is specified by the equation y=a·x+b (7) where a and b are coefficients. Letting XA, YA be the coordinate values of the approach starting point Pa along the X and Y axes, respectively, the following equation will hold: Y.sub.A =a·X.sub.A +b (7)' For a case where the curve OLC of the external shape is composed of a number of line segments and circular arcs, if the cutting starting point Pi lies on a predetermined line segment, then the normal line will be a straight line perpendicular to the line segment and passing through the cutting starting point; if the cutting starting point Pi lies on a predetermined circular arc, then the normal line will be a straight line connecting the cutting starting point Pi and the center of the circular arc. If we assume that the projection of the approach starting point PA (XA, YA, ZA) on a cutting plane CPL is Pi ', the three-dimensional coordinate values thereof will be (XA, YA, Zio). Accordingly, letting D be the distance between the cutting starting point Pi and the projected point Pi ', the following equations will hold: ##EQU2## tan θ=dz/D (9) Z.sub.A -Z.sub.io =dz (10) On the basis of the foregoing, the processor 102 obtains the coordinate values (XA, YA, ZA) of the approach starting point from Eqs. (7)' through (10). (10) When the coordinate values of the approach starting point PA are thus obtained, the processor 102 moves the tool TL along the Z axis from the present position (not shown) to a point Ps [see FIG. 4(A)] on the approach plane APL in the rapid-traverse mode, thereafter positions the tool at a point PA ' on the approach plane APL in the rapid-traverse mode by simultaneous two-axis control along the X and Y axes, and then moves the tool along the Z axis to the approach starting point PA in the rapid-traverse mode. This completes positioning of the tool TL at the approach starting point PA. It should be noted that the numerical control processing for the positioning from the present position to the point Ps, from the point Ps to the point PA ' and from the point PA ' to the point PA is performed in a manner similar to the path control processing of the step (4). (11) When positioning of the tool at the approach starting point PA is concluded, the processor 102 obtains incremental quantities Xi, Yi, Zi between PA and Pi and executes the path control processing of the step (4) by using these incremental quantities and the cutting velocity F. As a result, the tool TL is transported from the approach starting point PA to the cutting starting point Pi at the cutting velocity F. In the course of travel the tool begins to cut into the workpiece WK and finally arrives at the cutting starting point Pi. This completes the approach operation. (12) When the approach is completed, the processor 102 treats the point Pi as the cutting starting point and the point Qi as the cutting end point and, in like fashion, moves the tool along the +X axis in the rapid-traverse mode to perform cutting along the i-th cutting path. (13) When cutting is completed, the processor 102 obtains the difference (=|Ye -Ya |) between the present position coordinate Ya (stored in the working memory 112) along the Y axis and Y-axis coordinate Ye of the cut-in direction end point and checks whether or not the difference is greater than the pitch quantity P. (14) If |Ye -Ya |≧P holds, the processor 102 performs the operation i+1→i and repeats the processing from step (7) onward. (15) If |Ye -Ya |<P is found to hold at the decision step (13), then the processor 102 finally performs cutting by transporting the tool along the curve OLC of the external shape of the area, thereafter causing the NC data reader 103 to read the next item of NC data and repeating the processing from step (2) onward. Though the present invention has been described in detail in accordance with the drawings, the invention is not limited to the illustrated embodiment. For example, in the embodiment described, an area cutting command is inserted into the NC tape, an approach path and cutting paths are created by using the area cutting data that follow the area cutting command, and area cutting is performed along these paths. However, an arrangement can be adopted in which NC data for moving the tool along the approach path and cutting paths are created by the aforementioned method, the NC data are recorded on an NC tape, and approach and cutting control are performed by feeding the NC data recorded on the NC tape into an NC unit. According to the present invention, a tool is made to approach a workpiece plane obliquely, so that the workpiece may be cut by the cutting edge formed at the cutter side. This enables an improvement in cutting performance, allows the tool to cut into the workpiece smoothly when an approach is made, and permits cutting to be performed efficiently. Further, since the arrangement is such that the tool approaches the workpiece plane obliquely according to the present invention, a hole or the like need not be bored in advance at the cutting starting point. This shortens machining time and enables highly accurate area cutting to be performed. Accordingly, the present invention is well-suited for application to NC data creation systems for machine tool control or area cutting control, wherein area cutting is performed by numerical control. What is claimed is: 1. A method of approach in area cutting for cutting the interior of an area bounded by a curve of an external shape, comprising the steps of:(a) storing in memory an angle θ between a workpiece plane and a straight line connecting an approach starting point and a cutting starting point, and storing in memory a distance dz between the approach starting point and the cutting starting point in a direction perpendicular to the workpiece plane; (b) calculating coordinate values for the approach starting point using the angle θ and the distance dz, so that the direction of a projection of the straight line on the workpiece plane coincides with a direction of a normal line which is normal to the curve of the external shape at the cutting starting point; and (c) positioning a tool at the approach starting point; (d) automatically moving the tool to the cutting starting point in a cutting feed mode by moving the tool obliquely with respect to the workpiece in a direction defined by the entered angle data and thereafter starting cutting in the interior of the area bounded by the curve of the external shape. 2. A method of approach in area cutting according to claim 1, wherein said step (b) includes specifying the normal line by y=a·x+b, where a and b are coefficients, and obtaining three-dimensional coordinate values (XA, YA, ZA) for the approach starting point according to Y.sub.A =a·X.sub.A +b ##EQU3## tan θ=dz/D Z.sub.A -Z.sub.io =dz where (Xio, Yio, Zio) are three-dimensional coordinate values for the cutting starting point and D is the distance between the cutting starting point and a projection of the approach starting point on a plane containing the cutting starting point. 3. A method of approach in area cutting for cutting the interior of an area bounded by a curve of an external shape, comprising the steps of:(a) storing in memory a predetermined angle θ between a workpiece plane and a straight line connecting an approach starting point and a cutting starting point, storing in memory a predetermined distance dz between the approach starting point and the cutting starting point in a direction perpendicular to the workpiece plane, and storing in memory data necessary for creating NC data indicative of area cutting, including data indicating the curve of the external shape, cutting direction data, cut-in direction data, data representing pitch in the cut-in direction, and data representing the position of the approach plane; (b) obtaining the cutting starting point for area cutting by processing the data necessary for creating NC data; (c) calculating coordinate values of the approach starting point using the angle θ and the distance dz, so that the direction of a projection of the straight line on the workpiece plane coincides with a direction of a normal line which is normal to the curve of the external shape at the cutting starting point; and (d) creating NC data for positioning the tool at the approach starting point based on the cutting starting point obtained in said step (b) and the coordinate values of the approach starting point calculated in said step (c), as well as NC data for moving the tool from the approach starting point to the cutting starting point in a cutting-feed mode, the approach of the tool being controlled based on the NC data. 4. A method of approach in area cutting according to claim 1, wherein said step (b) includes specifying the normal line by y=a·x+b, where a and b are coefficients, and obtaining three-dimensional coordinate values (XA, YA, ZA) for the approach starting point according to Y.sub.A =a·X.sub.A +b ##EQU4## tan θ=dz/D Z.sub.A -Z.sub.io =dz where (Xio, Yio, Zio) are three-dimensional coordinate values for the cutting starting point, and D is the distance between the cutting starting point and a projection of the approach starting point on a plane containing the cutting starting point. 5. A method of approach in area cutting for cutting the interior of an area bounded by a curve of an external shape, comprising the steps of:(a) storing in memory curve data corresponding to the curve of an external shape of an area; (b) storing in memory entered angle data corresponding to an angle between a workpiece plane and a straight line connecting an approach starting point and a cutting starting point; (c) storing in memory distance data corresponding to a distance between the workpiece plane and the approach starting point in a direction perpendicular to the workpiece plane; (d) automatically calculating coordinate values for the approach starting point based on the stored angle data and the stored distance data, so that a projection of a straight line connecting the approach starting point and the cutting starting point on the workpiece plane exends to the cutting starting point and is normal to the curve of the external shape at the cutting starting point; (e) automatically positioning a tool at the approach starting point; (f) automatically moving the tool to the cutting starting point in a cutting feed mode by moving the tool obliquely with respect to the workpiece in a direction defined by the entered angle data; and (g) initiating cutting in the interior of the area bounded by the curve of the external shape.

1984-10-12

en

1987-10-27

US-20808280-A

Method of manufacturing a monolithic metallic matrix coated with a catalysis promoting metal oxide ABSTRACT The invention relates to a method for the manufacture of a metallic matrix which is &#34;monolithic&#34;, is coated with a catalysis promoting metal oxide and is disposed in a metal casing, in which the matrix is composed of alternately disposed plain and corrugated or folded metal sheets or plates, in which these sheets are stacked in a pile or are wound into a spiral. The method comprises a special resistance welding on the end faces of the matrix and arc welding of the side face of the matrix to the side of the casing, on which the metal oxide is applied. The present invention relates to a method for the manufacture of a mechanically stable, monolithic matrix of metal which is coated with a catalysis promoting metal oxide. It is known to use so-called "monolithic" metal elements as constructional supports for catalysts for the purification of vehicle exhaust gases. Those skilled in the art will understand the term "monolithic" as meaning a support structure of the honey comb type having a round, oval, square or otherwise shaped base with parallel channels extending through it in the flow direction of the exhaust gas. A catalyst matrix has heretofore been disclosed in a number of patents including U.S. Pat. No. 3,920,583; German Offenlegungsschrift No. 2,302,746; and German Offenlegungsschrift No. 2,450,664, the disclosures of which are incorporated herein by reference in their entireties. The known matrix is of scale-resistant steel and comprises an expanded metallic support, in which steel sheets of a specific and predetermined thickness are formed to be plain and other steel sheets are formed to be corrugated or folded and the sheets are arranged alternately in layers, in which the layers are stacked in a pile or wound into a spiral. As is the case with modern internal combustion engines, the requirements of mechanical stability for such metallic support structure are extremely high because, as a result of the ignition timing of a piston motor, extremely strong pulsations occur in the exhaust gas, and it has already been proposed in different ways to connect the superimposed plain and corrugated or folded steel sheets in a rigid manner by suitable measures. German Offenlegungsschrift No. 2,720,323 discloses a support structure wherein the metal strips are connected together by means of electron beam welding into an assembly which is rigid per se and then fastened in a housing. This method of mechanical stabilization requires work under high vacuum in addition to costly apparatus. This patent also proposes to fasten the metal strips together and to provide a connection with the housing by laser welding. The drawback of this method, in addition to the provision of a costly high-powered laser, is the danger of working with a laser beam. A method has now been discovered which enables the use of simple means to weld the strips together and to connect them to a housing without great cost. In summary, the present invention relates to a method of manufacturing a mechanically stable, monolithic metal matrix having a vertical axis and opposed end faces and which is coated with metal oxide to enable catalysis, is disposed in a metal jacket and comprises alternately superposed plain and corrugated or folded metal sheets of scale-resistant and high temperature resistant metal and in which the metal sheets are stacked in a pile or wound into a spiral. The present invention particularly resides in disposing one of the end faces of the matrix on a base electrode plate connected to one pole of a current source, and disposing the other, opposite end face on a second cover electrode plate connected to the other pole of the current supply, passing a welding current through the arrangement of matrix and electrode plates at least once, i.e. once or a plurality of times, to weld the metal plates at said end face disposed on said base electrode plate, then disposing the matrix in a way whereby the initially upper end face which is still unwelded lies on the base electrode plate and repeating the welding process, disposing and then welding the matrix in a metal jacket by means of an electric arc guided over the metal jacket in accordance with a required or predetermined weld path with the incorporation of at least one outer metal plate of said matrix, and coating the interior of the composite body thereby obtained with a metal oxide which promotes catalysis. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in greater detail with respect to its embodiments with reference to the accompanying drawing in which: FIG. 1 is a schematic diagram illustrating an apparatus for welding the end faces of alternating plain and corrugated metal strips of a monolithic metal matrix; FIG. 2 is a schematic diagram illustrating an apparatus for applying a rigid weld connection between the welded monolithic metal matrix and the metal casing into which said matrix has been inserted; FIG. 3 is a cross-sectional view of a modified grooved electrode plate for welding the end faces of a matrix using the apparatus of FIG. 1; and FIG. 4 illustrates diagrammatically various predetermined patterns of weld connections between the metal matrix and metal casing obtained with the apparatus of FIG. 2. In operation in practicing the method of the present invention and with particular reference to FIGS. 1 and 3, the end faces 10 and 12 of alternating plain metal sheets 14 and deformed metal sheets 16 of monolithic metal matrix 18 are disposed between and in electrical contact with electrode plates 20 and 22 made, for example, of copper and which may be either smooth as shown in FIG. 1 or provided with grooves 23 as shown in FIG. 3. The resulting assembly of matrix 18 and electrode plates 20 and 22 is disposed on base plate 24. Electrode support 26 carrying current conductor 28 is connected through ammeter 30 to a supply of alternating current 32 and base plate 24 is connected directly to current supply 32. Thus, electrode plate 20 is connected through base plate 24 to one pole of the arc welding apparatus shown in FIG. 1. Electrode plate 22 which is applied to upwardly directed end face 10 of matrix 18 is connected through conductor 28 and electrode support 26 to the other pole of the arc welding apparatus. On actuation of the circuit for from 1 to 10 seconds, e.g. for 2 to 3 seconds with amperages of from 100 to 350 A, e.g., approximately 240 A, the edges of the plain and corrugated metal sheets 14 and 16 are welded together at lower end face 12. This welding process may be repeated several times. After welding at the lower end face 12, matrix 18 is reversed whereby end face 12 is disposed against electrode plate 22 and end face 10 is disposed against elelctrode plate 20 and the welding together of metal sheets 14 and 16 at end face 10 is carried out in the same manner. With particular reference to FIGS. 2 and 4, metallic support matrix 18 is inserted into metal casing 34, for example a tubular jacket. A rigid weld connection 36 between matrix 18 and casing 34 may be carried out with the same apparatus. In this respect the metal casing 34 containing the metal support matrix 18 is disposed in electrical contact with base plate 24 which is connected with one pole of the arc welding apparatus. Welding electrode 28 is connected through electrode support 26 to the other pole of the apparatus. In this embodiment, current supply 33 provides a source of direct or alternating current. This enables the production of a weld seam 36 having any course which surrounds casing 34 with the inclusion of at least the outermost layer of sheets 14 and 16 in matrix 18 and therefore provides a mechanically stable weld connection between matrix 18 and casing 34. Operation under a protective gas such as argon and/or helium may be advantageous or even necessary, depending on the material. For this purpose, the arrows in FIG. 2 show the flow of protective gas through conduit 38 from a source not shown. The provision of grooves 23 in lower electrode plate 20 has proved to be particularly advantageous for the welding of the edges of sheets 14 and 16 at the end faces. Grooves 23 are formed in a way whereby the points of contact on the edges of the plain and corrugated metal sheets 14 and 16 lie in each case on the raised sections 40 of electrode plate 20. The spacing between raised sections 40 must be formed in a way whereby said raised sections correspond exactly to the spacing between the smooth plates 14 of the metal monolithic support matrix 18. It may also be advantageous to provide both electrode plates 20 and 22 with a grooved profile of this type. The metallic support structure or support produced after welding is then coated with a conventional support material for catalysts and may be treated in this respect, for example, with solutions of active catalyst metal. In this way the individual sheets 14 and 16 are coated on their surfaces, for example by wash coats, with a support material which pormotes catalysis, in particular a metal oxide having a high surface area such as activated Al2 O3. The elements cerium, zirconium, iron, nickel, rare earths or a combination of these in their oxide forms may be included in this metal oxide as catalyst additions thereto. According to a preferred advantageous embodiment of the invention plate 20 provided with grooves 23 is used as the base electrode plate. A cover electrode plate 22 provided with such grooves may also be used. The optimum welding results are obtained if the spacings between raised sections 40 separating grooves 23 correspond to the spacings between plain sheets 14 of the matrix 18. Uniformity of the end face welding may be increased by passing a welding current through the arrangement several times during the welding procedure and between each of these current applications rotating matrix 18 disposed on base electrode plate 20 slightly about its vertical axis. Protective gas may be used both for the welding of end faces 10 and 12 and for welding of casing 34 if the materials used require this procedure. The method for coating the welded arrangement with a catalysis promoting metal oxide is carried out in particular by applying a dispersion of said catalysis promoting metal oxide to the composite body which has been welded at its end faces and within the casing and by removing the dispersion agent by drying and then by calcining the coated body. It has proved to be convenient to use a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum at least for matrix 18. It is advantageous in this respect to pre-anneal the composite body in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before coating with the metal oxide. The present invention enables the use of simple means to weld alternate corrugated or folded and plain metal plates of a monolithic support matrix and to fasten this matrix in a metal casing jacket. Substantially less time and equipment is required than in the case of methods used in the prior art. In addition, the method of the present invention does not involve any safety risks. The matrix which, according to the invention, is disposed in a casing and coated with a catalysis promoting metal oxide has an unexpectedly high mechanical stability in comparison to known matrices, which stability may be observed from the measurement of the force required to press out the end faces of the sheet connections. The present invention is further taught in the following specific examples. EXAMPLE 1 (Comparative Example) A metal support matrix of an alloy consisting of 15% chromium, 4% aluminum and the remainder iron, having a diameter of 60 mm and a length of 76.2 mm and having 46 cells/cm2, produced by the spiral winding of a plain sheet and a corrugated sheet, is welded at its end face by an electron beam after insertion in a metallic casing. The connection between the matrix and the casing also is effected by electron beam welding, and in effect in the form of a spiral as shown in FIG. 4a. In order to provide a surface which is suitable for anchoring, the casing containing the support matrix is heated in a gas containing oxygen for 3 hours at 950° C. After cooling, coating with activated Al2 O3 is carried out in accordance with the wash coat method. The dispersion agent is then dried off and the coated body is calcined. EXAMPLES 2-6 (In accordance with the invention) In each example a matrix as described and produced in Example 1 is welded at its end faces, as shown in FIG. 1, by means of a suitable apparatus, after the production of the alternating deformed and plain sheets. For this purpose an alternating current of approximately 240 A is passed through the matrix for approximately 2-3 seconds, at a voltage of 220 V. This process is repeated several times with rotation of the body to be welded about its cylindrical axis. In this way the welding of the first lower end face is carried out. After reversing the matrix, the procedure is carried out in the same way for the second, now lower, end face. When the two end faces are welded, the matrix is disposed in a suitable metal casing or sleeve. Connection to the casing by welding is then carried out by the so-called WIG (wolfram-inert gas method), as shown in FIG. 2, in accordance with one of the weld variants shown in FIG. 4. This welding takes place with alternating or direct current of 220 V at a current strength of 40 A. The coating with Al2 O3 is carried out in the same way as in Example 1. EXAMPLE 3 The catalyst supports produced in accordance with Examples 1 and 2 to 6 were tested on a test machine (Instron) for measuring the pressing force required in units of Newton by means of a press to displace the fastened layers. The results are given in the folowing Table 1. TABLE 1 ______________________________________ Pressing out force of the different embodiments Example FIG. No. Pressing out force (N) ______________________________________ 1 4d 9,123 2 4b 8,927 3 4d 16,284 4 4e 14,322 5 4a 19,620 6 4c 20,110 ______________________________________ As can be seen from the examples, a composite body of a metal support and a wash coat may be produced in accordance with the method of the present invention at a lower cost, this body having at least the same pressing out forces as known composite bodies. Pressing out forces which are greater by 100% or more may be obtained with the same embodiment as the comparative example or other variants. What is claimed is: 1. In the method of manufacturing a mechanically stable, monolithic metal matrix having a vertical axis and opposed end faces and which is coated with a catalysis promoting metal oxide, is disposed in a metal jacket and comprises alternately superposed plain and corrugated or folded metal sheets of scale-resistant and high temperature resistant metal and in which the metal sheets are stacked in a pile or wound into a spiral, the improvement which comprises disposing one of the end faces of the matrix on a base electrode plate connected to one pole of a current source, and disposing the other, opposite end face on a second cover electrode plate connected to the other pole of the current supply, passing a welding current through the arrangement of matrix and electrode plates once or a plurality of times to weld the metal plates at said end face disposed on said base electrode plate, then disposing the matrix in a way whereby the initially upper end face which is still unwelded lies on the base electrode plate and repeating the welding process, disposing and then welding the matrix in the metal jacket by means of an electric arc guided over the metal jacket in accordance with a predetermined weld path with the incorporation of at least one outer metal sheet of said matrix, and coating the interior of the composite body thereby obtained with a catalysis promoting metal oxide. 2. A method as claimed in claim 1 wherein a base electrode plate provided with grooves is used. 3. A method as claimed in claim 2 wherein a cover electrode plate provided with grooves is used. 4. A method as claimed in claim 1 wherein a cover electrode plate provided with grooves is used. 5. A method as claimed in claims 2, 3 or 4 wherein the spacings between the raised portions separating the grooves correspond to the spacings between the plain metal sheets of the matrix. 6. A method as claimed in claim 5 wherein during the end face welding several welding currents are passed through the arrangement and between each of said currents the matrix lying on the base electrode plate is rotated slightly about its vertical axis. 7. A method as claimed in claim 2, 3 or 4 wherein during the end face welding several welding currents are passed through the arrangement and between each of said currents the matrix lying on the base electrode plate is rotated slightly about its vertical axis. 8. A method as claimed in claim 1 wherein a protective gas is used during the welding processes. 9. A method as claimed in claim 8 wherein a dispersion of a catalysis promoting metal oxide is applied to the composite body welded at its end faces and on its jacket side and as yet uncoated, the dispersion agent is removed by drying and the coated body is then calcined. 10. A method as claimed in claim 7 wherein a dispersion of a catalysis promoting metal oxide is applied to the composite body welded at its end faces and on its jacket side and as yet uncoated, the dispersion agent is removed by drying and the coated body is then calcined. 11. A method as claimed in claim 6 wherein a dispersion of a catalysis promoting metal oxide is applied to the composite body welded at its end faces and on its jacket side and as yet uncoated, the dispersion agent is removed by drying and the coated body is then calcined. 12. A method as claimed in claim 5 wherein a dispersion of a catalysis promoting metal oxide is applied to the composite body welded at its end faces and on its jacket side and as yet uncoated, the dispersion agent is removed by drying and the coated body is then calcined. 13. A method as claimed in claim 2, 3 or 4 wherein a dispersion of a catalysis promoting metal oxide is applied to the composite body welded at its end faces and on its jacket side and as yet uncoated, the dispersion agent is removed by drying and the coated body is then calcined. 14. A method as claimed in claim 9 wherein a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum is used at least for the matrix. 15. A method as claimed in claim 8 wherein a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum is used at least for the matrix. 16. A method as claimed in claim 7 wherein a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum is used at least for the matrix. 17. A method as claimed in claim 6 wherein a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum is used at least for the matrix. 18. A method as claimed in claim 5 wherein a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum is used at least for the matrix. 19. A method as claimed in claims 2, 3 or 4 wherein a scale-resistant and high temperature resistant chromium steel alloy containing the element aluminum is used at least for the matrix. 20. A method as claimed in claim 14 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide. 21. A method as claimed in claim 9 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide. 22. A method as claimed in claim 8 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide. 23. A method as claimed in claim 7 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide. 24. A method as claimed in claim 6 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide. 25. A method as claimed in claim 5 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide. 26. A method as claimed in claims 2, 3 or 4 wherein the composite body is pre-annealed in an atmosphere containing oxygen at a temperature between 600° and 1200° C. before being coated with the metal oxide.

1980-11-18

en

1982-02-23

US-9506593-A

Adjustable vehicle wheel restraint ABSTRACT A vehicle wheel restraint device include a base plate having a wheel plate assembly adjustably mounted in a lateral direction by a channel mounted to the base plate. A pair of outwardly angled wheel plates engage the vehicle wheel, with the spacing adjustable, and a tire belt is arranged to be tightened onto the tire with a ratchet wind up mechanism also carried by the wheel plate assembly. The base plate can be swung out by release of one of a pair of floor anchor bolts and pulling on a pull cord. This is a continuation of application Ser. No. 07/905,113 filed on Jun. 26, 1992 now abandoned. BACKGROUND OF THE INVENTION This invention concerns vehicle wheel restraints of the type including wheel chocks and tire straps. There is currently conducted extensive dynamometer and emissions testing of vehicles during development. Such devices are sometimes used to secure a vehicle in a testing enclosure during the performance of dynamometer and emissions tests. Such restraints have often involved fastening of individual devices by means of anchor bolts received in floor channels, with the varying vehicle dimensions requiring individual fitting of the devices for each vehicle tested. Some adjustable wheel restraints have heretofore been developed, as for example shown in U.S. Pat. Nos. 3,189,127; 2,998,102; and 1,776,935. The prior art devices have not provided easy but precise adjustment of the wheel chock, nor for an adjustment of the wheel chock laterally, as is required for floor anchored devices. The object of the present invention is to provide such capability in a vehicle wheel restraint device. SUMMARY OF THE INVENTION The present invention comprises a device including a base plate adapted to be fixed in a floor channel, by tee anchor bolts, a channel fixed to the base plate extending at a right angles to the floor channels. A wheel plate and tire strap wind up assembly are mounted to be set in any adjusted position along the length of the base plate channel to enable the wheel plates and tire strap to be aligned with the vehicle wheel. The wheel plate assembly includes a fixed wheel plate and an adjustable position wheel plate, which are outwardly angled from each other. The adjustable wheel plate may be slid towards or away from the fixed wheel plate on a threaded bar, the bar also movable to incremental adjusted positions held with a locking pin engaging one of a series of spaced openings. An adjusting nut on the threaded bar allows a fine adjustment of the position of the adjustable wheel plate to be snugly moved into engagement with the vehicle tire. A ratchet operated wind up reel enables a tire strap to be drawn tightly around the vehicle tire. The base plate can conveniently be freed from one floor channel anchor bolt to enable the entire device to be swung out, pivoting on a remaining anchor bolt to be moved from under the vehicle by means of a cord attached to the other end of the base plate. DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a wheel restraint device installed on one side of a vehicle shown in fragmentary form. FIG. 2 is an enlarged fragmentary plan view of the restraint device shown in FIG. 1. FIG. 3 is an enlarged side view of the wheel restraint device shown in FIG. 1, with an anchoring floor channel, with different size wheels shown in phantom lines. FIG. 4 is a perspective view of the wheel restraint device shown in FIGS. 1-3, showing the swing out manipulation in phantom lines. FIG. 5 is an enlarged exploded perspective view of the released anchor bolt assembly. DETAILED DESCRIPTION In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims. Referring to the drawings and particularly FIG. 1, a vehicle 10 is shown having a wheel 12 engaged by a wheel restraint device 14. The wheel restraint device 14 is held by two anchor bolts 16A passing through a base plate 28 and 16B received in a floor channel 18, a parallel series of sub floor channels usually incorporated in test chambers. The wheel 12 is confined between a fixed wheel plate 20 and an aligned adjustable position wheel plate 22, each wheel plate 20, 22 angled outwardly from each other. A strap 24 fixed at one end passes around the top of the wheel 12 and is wound onto a ratchet belt wind-up subassembly 26 to tightly hold the wheel 12. A separate tie down strap 30 anchored with another anchor bolt 32 connected to the vehicle body is required also. This should be located to prevent any lateral movement of the vehicle under the influence of engine vibration during testing. The base plate 28 is underlain with a low friction plastic layer 35, and has a generally triangular main portion 36, the base side receiving the anchor bolts 16A, 16B. An extension portion 38 projects laterally inward. An adjustment channel 40 is fixed to the base plate 28, bracing gussets 42 fixed along the length thereof. A wheel plate-belt wind up assembly 44 is mounted to be slidable along the adjustment channel 40, to be guided thereby in a transverse direction to the direction of adjustment of the wheel plates 20, 22 and to be fixed in any adjusted position with a tee bolt 46 extending through a splice plate 48. The fixed wheel plate 20 is included in the assembly 44, braced with gussets 50 fixed to a wheel plate mounting plate 52. The ratchet-belt wind up subassembly 26 is also included in assembly 44, mounted by bracket plates 54 fixed to a base plate 56 welded to the back of the fixed wheel plate 20. The ratchet-belt windup subassembly 26 includes a wind up shaft 58 on which is wound the tire belt 24. A ratchet wheel 60 and panel 62 allow a torque nut 64 affixed to an extension shaft 66 to wind up and hold the belt 24. A wheel plate holder bar 68 extends normally to the channel 40 and is slidably mounted in a housing 70, with an incremental adjustment enabled by a locking pin 72 (FIG. 3) engaging one of a series of locating recesses 74 formed along the length of the holder bar 68. A pin retraction mechanism 71 allows raising of the pin 72 to free the holder bar 68 for adjustments of the spacing of the wheel plates 20, 22 in the longitudinal direction. The adjustable wheel plate 22 is fixed to a mounting base 76 which also has the other end of belt 24 attached with a hook 78 and recess 80. The mounting base includes a guide tube 82 slidably receiving the holder bar 68. The end of the holder bar 68 is threaded and receives an adjusting nut 84, which when advanced allows a fine adjustment of the spacing between the fixed wheel plate 20 and adjustable wheel plate 22 to be fit tightly to the wheel 12. A compression spring 86 forces the guide tube 82 out when the nut 84 is reversely rotated to open up the spacing. An indicator 83 (FIG. 2) is employed for more convenient set up in a preselected adjusted position. The anchor bolt 16B can be removed by means of a slotted retainer plate 88 bolted to a slotted mounting plate 90 affixed to the top of base plate 34. A pull cord 92 is attached at 94 to the far end of the extension portion 38 of the base plate 34. A handle attached at the other end allows the base plate 34 to be swung out, pivoting about the anchor bolt 16A, with the low friction plastic layer 35 reducing the effort required. The wheel restraint device 14 will normally be used in pairs, one for each front (or rear) wheel of the vehicle 10. Thus, easy adjustment of the location and spacing of the wheel plate bolt wind up assembly 26 may be accomplished to be matched to the dimensions of a particular vehicle to be restrained. The spacing of the wheel plates 20, 22 is also readily carried out. The vehicle 10 is thereby very securely restrained. What is claimed is: 1. A vehicle wheel restraint device comprising:a base plate; anchor means for fixing said base plate to a supporting floor; a single guide channel affixed to said base plate extending thereacross in a first transverse direction; a wheel plate assembly including a pair of aligned wheel plates outwardly angled from each other, one of said wheel plates movable along said guide channel to be located at positions along said guide channel; means mounting the other of said wheel plates in said wheel plate assembly to be adjustably movable towards and away from said one wheel plate in a longitudinal direction normal to said direction in which said single guide channel extends; and, means for fixing said one wheel plate at locations along said guide channel on said base plate, means for fixing said other wheel plate in any adjusted position relative said one wheel plate, whereby said wheel plates can be fixedly located on said base plate on said supporting floor by transverse adjustment of said one wheel plate along said guide channel on said base plate and the spacing of said wheel plates adjusted by said adjustment of said other wheel plate in said longitudinal direction. 2. The vehicle wheel restraint device according to claim 1, wherein said wheel plate assembly further includes a belt wind up mechanism fixed to said one wheel plate and a tire belt fixed at one end spaced from said belt wind-up mechanism, said belt extending across said wheel plates and having the other end thereof attached to said belt wind up mechanism to be able to be tightened over a tire of a wheel disposed between said wheel plates. 3. The vehicle wheel restraint device according to claim 1, wherein said means mounting said other of said wheel plates comprises a holder bar and means attaching said other of said wheel plates to said holder bar, means mounting said holder bar for longitudinal sliding movement with respect to said one wheel plate and wherein said means for fixing said other wheel plate comprises locking means for locking said holder bar at incrementally spaced locations along the path of said longitudinal sliding movement. 4. The vehicle wheel restraint device according to claim 3, wherein said means attaching said holder bar to said other wheel plate includes fine adjustment means for continuously adjusting the position of said other of said wheel plates on said holder bar. 5. The vehicle wheel restraint device according to claim 1, wherein said means fixing said one wheel plate at locations along said guide channel comprises an anchor bolt received in said guide channel and fixed relative to said one wheel plate. 6. The vehicle wheel restraint device according to claim 1, wherein said anchor means comprises a pair of anchor bolts secured to said base plate spaced apart in said longitudinal direction normal to said wheel plates, and means for releasing one of said pair of anchor bolts from said base plate to allow swing out of said base plate on the remaining secured anchor bolt. 7. The vehicle wheel restraint device according to claim 6, further including a pull cord attached to said base plate to assist in swing out thereof. 8. The vehicle wheel restraint device according to claim 7, further including a low friction plastic layer affixed to the underside of said base plate.

1993-07-20

en

1994-03-15

US-11901093-A

Cell panel with extruded burner target plates and process for making same ABSTRACT A cell panel for a gas furnace having a burner box containing combustion burners includes burner target plates formed by an extrusion process from the sheet material forming the cell panel. The burner target plates include a concave side positioned to face the discharge side of a corresponding burner, and a convex side upon which the flared inlet port of a corresponding heat exchanger cell may be securely seated. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to gas furnaces and, in particular, to the cell panel positioned between the burner box and heat exchanger cells of a gas furnace. More specifically, but without restriction to the particular embodiment hereinafter shown and described, this invention relates to burner target plates formed in the cell panel by extrusion. 2. Discussion of the Prior Art Gas furnaces typically include a primary heat exchanger positioned adjacent a burner box containing burners. During operation of the furnace, a blower moves circulating air over the heat exchanger to produce heated air that is directed to a desired location. Gas is supplied to the burner box by a gas manifold having orifices that direct the gas into the burners. The gas exiting the burners is ignited by an ignitor provided in the burner box. The burners allow combustion of the gas as well as direct heat into the heat exchanger. The typical heat exchanger includes cells with a channel or pass formed in each cell to direct the flow of heat and flue gas produced by combustion. These cells are positioned side by side in a parallel manner and are provided with a predetermined spacing to allow the blower air to flow around the cells. The blower air is thus heated by convection as it moves over the cells. Each of the channels in the primary heat exchanger cells includes a flared inlet port as well as a discharge port. A sheet metal panel or cell panel having burner target plates is typically provided to position the burner box relative to the cells contained in the heat exchanger. The burner target plates provided in the cell panel serve two functions in that they provide a seat for the flared inlet port of a corresponding heat exchanger panel while also providing a zone or target area with a central opening at which a corresponding burner is directed so that heat and flue gas produced by combustion is directed into the corresponding heat exchanger cell. Prior art burner target plates are individually manufactured in a separate stamping process and then either fastened to large stamped openings provided in the cell panel or similarly fastened to a smaller sheet metal panel secured to the discharge side of the burner box. In the former arrangement, the burner box has an un-paneled discharged side which is secured to the cell panel to cover the area containing the target plates. The residential heating industry has advanced with the advent of condensing gas furnaces. These furnaces typically included a primary heat exchanger as well as a condensing heat exchanger. A blower in these condensing heat furnaces similarly provides circulating air flow over both heat exchangers to produce heated air that may be directed to a desired location by a system of ductwork and registers. In such condensing furnaces, both the primary heat exchanger and the condensing heat exchanger include cells with a channel or pass formed therein to direct the flow of flue gas produced by combustion. These cells in both the primary and secondary heat exchangers are positioned side by side in a parallel manner and are provided with a predetermined spacing to allow blower air to flow around both groups of heat exchanger cells. Gas is similarly provided to the condensing furnace by a gas manifold having orifices that direct the gas into burners contained in a burner box. The gas is ignited by an ignitor as it exits the burners contained in the burner box. The heat and flue gas produced by combustion is then directed into the primary heat exchanger cells and induced to move through the heat exchangers. Each of the channels provided in the primary heat exchanger cells eventually terminates at a discharge port. The discharge ports of the primary heat exchanger are typically aligned and secured in a first sheet metal panel forming the discharge side of the primary heat exchanger. The condensing heat exchanger of the furnace is configured in a similar manner to its primary heat exchanger. A series of side by side condensing cells is provided. Each of these condensing cells has an inlet port for receiving flue gas discharged from the primary heat exchanger. The inlet ports of the condensing heat exchanger cells are aligned and secured in a second sheet metal panel forming the inlet side of the condensing heat exchanger. The two heat exchangers are mounted together to form a single intrical unit capable of receiving and heating clean circulating air provided from the blower. These condensing gas furnaces similarly include a cell panel including burner target plates for aligning the primary heat exchanger cell and directing burner discharge into the cells. Although the condensing gas furnace is an advancement over prior gas-fired furnaces including only a primary heat exchanger, the cell panels typically used in these condensing gas furnaces are similar to those used in the prior single heat exchanger furnaces. The cell panels in current condensing gas furnaces also require the manufacturing of individual burner target plates that are fastened to large openings provided in the burner box area of the cell panel or similarly fastened to openings provided on the discharge side of the burner box which would then be mounted to an appropriate opening in the cell panel. OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to improve gas furnaces having a primary heat exchanger with cells and a cell panel. It is a further object of the present invention to form burner target plates in the material forming the cell panel of a gas furnace. A further object of the present invention is to reduce the cost of manufacturing a cell panel having burner target plates for receiving the flared inlet ports of corresponding heat exchanger cells of a gas furnace. Still another object of the present invention is to position the primary heat exchanger cells of a gas furnace in a parallel manner to allow heat transfer between the cells and circulating blower air moving over the cells. Yet another object of the present invention is to extrude burner target plates in a cell panel from the material forming the cell panel so that heat and flue gas discharged from the burners is directed into corresponding channels provided in the primary heat exchanger cells of a gas furnace. An additional object of the present invention is to reduce the time required to assemble the cell panel and primary heat exchanger cells of a gas furnace. These and other objects are attained in accordance with the present invention wherein there is provided a cell panel for a gas furnace having a burner box containing combustion burners. Each of the burners is utilized to combust gas and direct the resultant heat and combustion products into the flared inlet port of a corresponding primary heat exchanger cell. The cell panel includes a rigid sheet member of substantially flat surface area formed from an extrudable material. The cell panel is provided with a plurality of collinear burner target plates formed in the rigid sheet member. The number of burner target plates corresponds to the number of burners provided in the burner box which, in turn, corresponds to the number of heat exchanger cells provided in the primary heat exchanger. An appropriate number of burner target plates will vary with furnace capacity and any such particular number is not considered a function of the present invention. Each of the plates is provided with a central opening. The plates are extruded from the sheet material forming the cell panel. The extruded burner target plates include a concave side positioned to face the discharge side of a corresponding combustion burner, and a convex side being formed so that the flared inlet port of a corresponding primary heat exchanger cell can be seated thereon. In this manner, when each of the flared inlet ports of the primary heat exchanger cells is seated upon and secured to the convex side of a corresponding burner target plate, the primary heat exchanger cells are aligned within the furnace to allow heat transfer between the cells and the circulating blower air. The extruded burner target plates formed in the cell panel are each further provided with a bevelled flange segment that is oval in configuration and that extends outwardly from the flat surface of the rigid sheet member forming the cell panel. The bevelled flange segment has a distal edge that forms the boundary of a raised planar region including the central opening. A truncated cusp member that is annular in configuration is extruded from the sheet material forming the raised planar region. The annular cusp member extends outwardly from the raised planar region thereby giving depth to the central opening. BRIEF DESCRIPTION OF THE DRAWING Further objects of the present invention together with additional features contributing thereto and advantages accruing therefrom will be apparent from the following description of a preferred embodiment of the invention which is shown in the accompanying drawing with like components throughout indicated by like reference numerals, wherein: FIG. 1 is a perspective view of a condensing gas furnace incorporating the cell panel of the present invention and showing the furnace burner box disassociated from the cell panel; FIG. 2 is a perspective view of the primary and condensing heat exchangers provided in the condensing furnace of FIG. 1; FIG. 3 is a side elevational view of one of the primary heat exchanger cells shown in FIG. 2; FIG. 4 is a front elevational view of the heat exchanger cell shown in FIG. 3; FIG. 5 is a partial side elevational view of the cell panel according to the present invention; and FIG. 6 is an enlarged partial side elevational view, taken along section line 6--6 of FIG. 5, showing a burner target plate according to the present invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring first to FIG. 1, there is shown a gas-fired condensing furnace 10 including a primary heat exchanger 12 having heat exchanger cells 14. A condensing heat exchanger 16 is shown positioned below the primary heat exchanger 12. The condensing heat exchanger 16 includes a number of condensing heat exchanger cells 18 as represented by the single cell 18 shown in phantom in FIG. 2. A blower 20 is provided adjacent to the heat exchangers 12 and 16 to move clean circulating air over the heat exchangers during operation of the furnace. The gas furnace 10 also includes a burner box 22 which is supplied gas by a gas manifold 24. The gas manifold 24 contains orifices (not shown) that direct the supply gas into burners 26. The burner box 22 containing the burners 26 is mounted to a cell panel 28 when the furnace 10 is assembled. The cell panel 28 is preferably made of aluminized steel. Upon ignition of the gas provided to the burners 26, an inducer 30 is activated to induce the flow of heated flue gas through the heat exchangers 12 and 16. The cell panel 28 includes burner target plates 32 as shown in FIG. 2. Each of the burner target plates 32 includes a central opening 33 and each of the primary heat exchanger cells 14 includes a corresponding channel 34. The central opening 33 is preferably oval in shape but may be of any suitable shape including circular. The channels 34 each include a first pass 36, a second pass 38, and a third pass 40 as shown in FIG. 2 and FIG. 3. The primary heat exchanger 12 includes a discharge side 42 while the condensing heat exchanger 16 includes a inlet side 44 and a discharge side 46. The discharge side 46 of the condensing heat exchanger 16 includes an inducer mounting opening 48. The inducer 30 is mounted onto mounting opening 48 as shown in FIG. 1 and, during operation of the furnace, induces flow of heated flue gas through the heat exchangers 12 and 16 as well as moves the flue gas into venting pipe (not shown) so that the flue gas produced by combustion may be appropriately vented. The cell panel 28 also includes a large rectangular opening 50, FIG. 2, which allows the cell panel 28 to be mounted against the discharge side 46 of the condensing heat exchanger 16 so that the heat exchangers 12 and 16 may be properly positioned and aligned on top of each other. As most clearly shown in FIG. 3, the primary heat exchanger cells 14 each include a flared inlet port 52 and a flared discharge port 54. The flared discharge ports 54 are secured and aligned in the sheet metal member forming the discharge side 42 of the primary heat exchanger 12 as shown in FIG. 2. Referring now to FIGS. 2, 5 and 6, there is shown that the burner target plates 32 generally include a concave side 56 and a convex side 58. More particularly, each of the burner target plates 32 includes a bevelled flange segment 60 that is oval in configuration, a raised planar region 62 and a truncated cusp member 64. As shown in FIGS. 3, 4 and 5 the flared inlet port 52 of each of the primary heat exchanger cells 14 is also oval in configuration and corresponds in size and shape to the raised bevelled flange segment 60 so that the flared inlet port 52 may be snugly seated upon the convex side of the bevelled flange segment 60. As specifically shown in FIGS. 2 and 6, the flange segment 60 includes an oval proximal edge 66 which is contiguous with the sheet metal forming the flat surface area of the cell panel 28. The flange segment 60 also includes an oval distal edge 68 which forms the boundary of the raised planar region 62. The truncated cusp member 64 similarly includes an oval proximal edge 70 which is contiguous with the sheet material forming the raised planar region 62. The truncated cusp member 64 finally terminates at an oval distal edge 72. The bevelled flange segment 60, raised planar region 62, and truncated cusp member 64 each have an outer surface, as shown in FIG. 6, which join one another at their edges to form the convex side 58 of the burner target plate 32. Similarly, the bevelled flange segment 60, raised planar region 62, and truncated cusp member 64 each include an inner surface, as shown in FIG. 2. In a like manner, these inner surfaces join together to form the concave side 56 of the burner target plates 32. The bevelled flange segment 60 is further provided with preformed screw holes 74 which correspond to preformed screw holes 76 provided in the flared inlet port 52 of each primary heat exchanger cell 14 as shown in FIG. 4. Upon assembly of the condensing gas furnace 10, each of the flared inlet ports 52 of the primary heat exchanger cells 14 is seated upon the outer surface of the bevelled flange segment 60 and secured thereto by sheet metal screws passing from the inner surface of the bevelled flange segment 60 into the corresponding screw holes 76 provided in the flared inlet port of 52. Alternatively, self-taping screws may be employed thus eliminating the need to preform the screw holes 76. During operation of the condensing furnace 10, heated flue gas is discharged from the burners and directed at the concave side 56 of the burner target plates 28. The central opening 33 is given depth and definition by the truncated cusp member 64 which protrudes into the first pass 36 of the primary heat exchanger cells 14 when the cells 14 are mounted to the cell panel 28. In this manner, the truncated cusp member 64 provides a channeling effect that smoothly directs the flow of heated flue gas into the first pass 36 of the channel 34. There has thus been shown and described a design for the burner target plates 32 that allows for directing the flow of hot flue gas produced by operation of the furnace into the channel 34 of the cells 14 and that also allows for quick and ready assembly of the cells 14 to the cell panel 28. In accordance with one aspect of the present invention, the burner target plates 32 are extruded from the sheet material forming the cell panel 28 rather than being individually manufactured by a stamping process and then secured to large openings provided in the cell panel 28 as was done in prior cell panels. This extrusion process indirectly reduces the time required to assemble the cell panel to the heat exchanger cells 14 because the burner target plates are made a part of the cell panel 32 thus requiring no assembly of individual burner target plates to the cell panel. The cost of manufacturing the complete cell panel 28 is directly reduced because only one manufacturing process is required rather than several stamping and assembly processes. The extrusion process for forming the burner target plates 32 in the sheet material of the cell panel 28 includes a two stage process including a preliminary notch and pierce stage followed by a forming stage. The forming stage includes both drawing and extruding. In the notch and pierce stage, the rectangular sheet material forming the cell panel 28 is positioned between a first set of dies. This first set of dies blanks or stamps out the required number of central openings 33 in the sheet material as well as the rectangular opening 50 for receiving the condensing heat exchanger 16. Also at this stage, the corners of the rectangular sheet material are notched out so that 90° flange segments may be formed around the periphery of the cell panel 28. Once the blank square material forming the cell panel 28 has been notched and pierced, it is then moved to a forming station. The forming station includes a second set of dies for drawing and extruding the burner target plates 32 of the present invention. The second set of dies include forming elements for fabricating the burner target plates 32 around the previously pierced openings 33. One die of the second set includes a protruding forming element corresponding to the shape and size of the concave side 56 of the burner target plate 28, while the other die of the second set includes a recessed forming element corresponding to the shape and size of the convex side 58 of a respective burner target plate 32. Each of the forming elements in the second set of dies include a forming section corresponding to the bevelled flange segment 60, raised planar region 62, and the truncated cusp member 64 of the burner target plate 32. Each die of the second set is relatively large weighing between 5,000 and 9,000 pounds, with dimensions of up to 48 by 48 by 60 inches. Each die is connected to a set of nitrogen cylinders that control the movement of the dies during the forming process. Mill oil on the sheet material forming the cell panel provides sufficient lubrication during the drawing and extruding process. As the nitrogen cylinders are activated when the previously notched and pierce cell panel 28 is positioned therebetween, the forming elements corresponding to the shape of the burner target plates are brought together. As a result of the weight of the dies and the pressure provided by the nitrogen cylinders, the bevelled flange segments 60 are formed by drawing, that is, stretching and shaping the material in the immediate vicinity to form the flange segment 60. The raised planar region 62 remains coplanar with the distal edge 68 during the drawing formation. The planar region 62 is thus moved a distance away from the substantially flat surface area of the sheet material comprising the cell panel 28. The forming elements in the second set of dies also engage the sheet material of the raised planar region 62 immediately surrounding the central openings 33 to further extrude this material to form a respective truncated cusp member 64 around each of the previously pierced central openings 33. The second set of dies are then moved away from each other and the cell panel 28 completed in accordance with the present invention is removed therefrom and inventoried for later assembly. The cell panel of the present invention including the extruded burner target plates formed therein is not limited to use in condensing heat furnaces and has been shown and described in configuration therewith only by way of illustration. A cell panel including the extruded burner target plates in accordance with the present invention may be effectively used in a verity gas-fired furnaces including those with only one heat exchanger. The four burner target plates shown in the accompanying drawing figures is by way of illustration only and is not intended as a limitation of the number or placement of burner target plates formed in accordance with the present invention. Thus, while this invention has been described in detail with reference to a single preferred embodiment, it should be appreciated that the present invention is not limited to that precise embodiment. Rather, in view of the present disclosure, many modifications and variations would present themselves to those of skill in the art without departing from the scope and spirit of this invention, as defined in the following claims. What is claimed is: 1. A cell panel for a gas furnace having a burner box containing combustion burners, each of the burners for directing heat into the flared inlet port of a corresponding heat exchanger cell to heat a flow of circulating air passing over the cells, the panel comprising:a rigid sheet member of substantially flat surface area formed from an extrudable material, the sheet being positioned between a discharge side of the burners and the inlet ports of the heat exchanger cells; and a plurality of burner target plates formed in said rigid sheet member, each of the plates having a central opening and being extruded from the sheet material to form a concave side being positioned to face the discharge side of a respective combustion burner, and a convex side being formed so that the flared inlet port of a corresponding heat exchanger cell can be seated thereon; whereby when each of the flared inlet ports of the heat exchanger cells is seated upon and secured to the convex side of a respective burner target plate, the heat exchanger cells are aligned within the furnace to allow heat transfer between the cells and the circulating air. 2. The cell panel according to claim 1 wherein each of the burner target plates includes:a bevelled flange segment having an inner and an outer surface, being oval in configuration, and extending outwardly from the flat surface of said rigid sheet member, said bevelled flange segment further having a distal edge and a proximal edge that is contiguous with the flat surface of said rigid sheet member; a raised planar region including the central opening and having an inner and outer surface, said raised planar region being bound by and contiguous with said distal edge of the flange segment; and a truncated cusp member having an inner and outer surface, being annular in configuration, and extending outwardly from said raised planar region, said truncated cusp member having a distal edge and a proximal edge being contiguous with said raised planar region, the concave side of each of said burner target plates thereby being formed by the inner surfaces of the flange segment, planar region, and cusp member and the convex side of each of the target plates being formed by said outer surfaces of the flange segment, planar region, and cusp member. 3. The cell panel according to claim 2 wherein the flared inlet port of each of the heat exchanger cells is oval in configuration and formed to seat snugly upon the outer surface of a corresponding bevelled flange segment to thereby align the cells within the furnace while allowing the corresponding truncated cusp member to protrude into a channel provided in the heat exchanger cell. 4. The cell panel according to claim 3 wherein said bevelled flange segment further includes four holes spaced thereabout, each of these flange holes corresponding to a hole in the flared inlet port of the heat exchanger cells so that the cell panel and heat exchanger cells can be secured together by sheet metal screws. 5. The cell panel according to claim 4 wherein the burner box is secured to said rigid sheet member so that the discharge side of each of the combustion burners is positioned proximate a corresponding burner target plate to center the burner on the central opening of the plate whereby heat and flue gas discharged from the burner is directed through the opening and into the channel formed in the heat exchanger cell. 6. The cell panel according to claim 1 wherein the material forming said rigid sheet member is aluminized steel. 7. A cell panel for use in a gas furnace having a burner box containing combustion burners, each of the burners for directing heat into the flared inlet port of a corresponding heat exchanger cell to heat a flow of circulating air passing over the cells, said cell panel comprising:a rigid sheet member of substantially flat surface area formed from an extrudable material, the sheet being positioned between a discharge side of the burners and the inlet ports of the heat exchanger cells; and a plurality of burner target plates formed in said rigid sheet member, each of the plates having a central opening and being extruded from the sheet material to form a concave side being positioned to face the discharge side of a respective combustion burner, and a convex side being formed so that the flared inlet port of a corresponding heat exchanger cell can be seated thereon, each of the burner target plates further including; a bevelled flange segment having an inner and outer surface, being oval in configuration, and extending outwardly from the flat surface of said rigid sheet member, said bevelled flange segment further having a distal edge and a proximal edge being contiguous with the flat surface of said rigid sheet member; a raised planar region including the central opening and having an inner and outer surface, said raised planar region being bound by and contiguous with said distal edge of the flange segment; and a truncated cusp member having an inner and outer surface, being annular in configuration, and extending outwardly from said raised planar region, said truncated cusp member having a distal edge and a proximal edge being contiguous with said raised planar region, the concave side of each of said burner target plates thereby being formed by the inner surfaces of the flange segment, planar region, and cusp member and the convex side of each of the target plates being formed by said outer surfaces of the flange segment, planar region, and cusp member. 8. The cell panel according to claim 7 wherein the flared inlet port of each of the heat exchanger cells is oval in configuration and formed to seat snugly upon the outer surface of a corresponding bevelled flange segment to thereby align the cells within the furnace while allowing the corresponding truncated cusp member to protrude into a channel provided in the heat exchanger cell. 9. The cell panel according to claim 8 wherein said bevelled flange segment further includes four holes spaced thereabout, each of these flange holes corresponding to a hole in the flared inlet port of the heat exchanger cells so that the cell panel and heat exchanger cells can be secured together by sheet metal screws. 10. The cell panel according to claim 9 wherein the burner box is secured to said rigid sheet member so that the discharge side of each of the combustion burners is positioned proximate a corresponding burner target plate to center the burner on the central opening of the plate whereby heat and flue gas discharged from the burner is directed through the opening and into the channel formed in the heat exchanger cell. 11. The cell panel according to claim 7 wherein the material forming said rigid sheet member is aluminized steel. 12. A process for simultaneously forming the concave and convex sides of a burner target plate in sheet material comprising the cell panel in a gas furnace having a burner box containing gas combustion burners, each of the burners for directing heat through a central opening formed in the target plate and into a corresponding heat exchanger cell, each of the heat exchanger cells having a flared inlet port that seats upon the convex side of the burner target plate so that the cells are aligned in the furnace to allow heat transfer between the cells and clean circulating air passing through the heat exchanger, said process including the steps of:piercing a series of collinear central openings in the sheet material forming the cell panel, each opening being positioned in an area of sheet material corresponding to the area forming a respective burner target plate; securing said sheet material between dies having forming elements, one of the dies having a first forming element corresponding in size and shape to the convex side of a respective burner target plate and the other die having a second forming element corresponding in size and shape to the concave side of the respective target plate, said two forming elements capable of mating with each other while the sheet material is positioned therebetween; and causing the dies to move toward each other so that the mating forming elements engage respective sides of the sheet material in the area of a corresponding burner target plate opening to form a respective burner target plate. 13. The process according to claim 12 wherein the step of causing the dies to move toward each other includes the steps of:drawing, simultaneously, inner and outer surfaces of a bevelled flange segment from said sheet material so that the flared inlet port of a corresponding heat exchanger cell is seatable on the outer surface of the bevelled flange segment, the flange segment thereby having a distal edge and a proximal edge being contiguous with the sheet material surrounding a respective plate; forming a raised planar region having a respective central opening, from the sheet material in the plane containing the distal edge of said bevelled flange segment, said forming step occurring concurrently with said drawing step; and extruding a truncated cusp member from the sheet material immediately surrounding a corresponding central opening, said truncated cusp member extending the sheet material away from said raised planar region and terminating with a distal edge surrounding the central opening whereby when the flared inlet port of a corresponding heat exchanger cell is seated upon said bevelled flange segment, the extruded cusp member extends into a channel provided in the heat exchanger cell. 14. A cell panel for use in a gas furnace having a burner box containing combustion burners, each of the burners for directing heat into the flared inlet port of a corresponding heat exchanger cell to heat a flow of circulating air passing over the cells, said cell panel comprising:a rigid sheet member of substantially flat surface area formed from an extrudable material, the sheet being positioned between the discharge side of the burners and the inlet ports of the heat exchanger cells; and a plurality of collinear burner target plates formed in said rigid sheet member, each of the plates having a central opening and being extruded and drawn from the sheet material to form a concave side being positioned to face the discharge side of a corresponding combustion burner, and a convex side being formed so that the flared inlet port of a corresponding heat exchanger cell can be seated thereon. 15. The cell panel according to claim 14 wherein each of the burner target plates further includes:a bevelled flange segment having an inner and an outer surface, being oval in configuration, and extending outwardly from the flat surface of said rigid sheet member, said bevelled flange segment further having a distal edge and a proximal edge being contiguous with the flat surface of said rigid sheet member; a raised planar region including the central opening and having an inner and outer surface, said raised planar region being bound by and contiguous with said distal edge of the flange segment; and a truncated cusp member having an inner and outer surface, being annular in configuration, and extending outwardly from said raised planar region, said truncated cusp member having a distal edge and a proximal edge being contiguous with said raised planar region; the bevelled flange segment being formed by simultaneously drawing the inner and outer surfaces of the segment from said sheet material so that the flared inlet port of a corresponding heat exchanger cell is seatable on the outer surface of the bevelled flange segment, said drawing process thereby forming the distal edge of the flange segment and the proximal edge thereof being contiguous with the sheet material surrounding the burner plate; the raised planar region formed by moving an area of sheet material bound by the distal edge of the flange segment with the plane containing the distal edge while the bevelled flange segment is being drawn; and the truncated cusp member being formed by extruding sheet material from the area immediately surrounding a corresponding central opening, said truncated cusp member extending the sheet material away from said raised planar region and terminating with a distal edge surrounding the central opening whereby when the flared inlet port of a corresponding heat exchanger cell is seated upon said bevelled flange segment, the extruded cusp member extends into a channel provided in the heat exchanger cell.

1993-09-09

en

1994-09-13

US-33874573-A

Air heating and cooling system for a vehicle passenger compartment ABSTRACT The output of a blower is supplied to three branch ducts in one of which the air passes through a cooler, in another of which it passes through a heater and in the third of which the air always passes through unchanged. A common control valve controls the discharge from the three ducts, never allowing discharge from more than two of them and providing smooth transition as the valve is moved from one extreme position to the other, from 100 percent heated air to 100 percent unchanged air to 100 percent cooled air. For reasons of heat exchanger design, the air passing through the duct in which the heater is located is branched off downstream of the cooling device from the duct in which the cooler is located. United States Patent 1191 1451 May 7, 1974 Scheidel et al. AIR HEATING ANDCOOLING SYSTEM FOR A VEHICLE PASSENGER COMPARTMENT Inventors: Wolfgang Scheidel, Buhlertal; Helmut Steinmann, Baden-Baden, both of Germany Robert Bosch GmbH, Stuttgart, Germany Filed: Mar. 7, 1973 Appl. No: 338,745 Assignee: Foreign Application Priority Data Mar. 8, 1972 Germany 2211091 U.S. Cl 165/42, 98/206, 62/244 Int. Cl .1 B60h 3/00 Field of Search 98/2.01, 2.05, 2.11; References Cited UNITED STATES PATENTS 12/1958 Sparrowm, 165/26 2,860,567 11/1958 Wilfert 98/206 2,729,158 l/l956 Wilfert.... 98/2.06 2,718,839 9/1955 warm. 98/206 PrimaryExaminer-Meyer Perlin Attorney, Agent, or Firm-William R. Woodward [57] ABSTRACT The output of a bloweris supplied to three branch ducts in one of which the air passes through a cooler, in another of which it passes through a heater and in the third of which the air always passes through un- V changed. A common control valve controls the discharge from the three ducts, never allowing discharge from more, than two of them and providing smooth transition as the valve is moved from one extreme position to the other, from 100 percent heated air to 100 percent unchanged air to 100 percent cooled air. For reasons of heat exchanger design, the air passing through the duct in which the heateris located is branched off downstream of the cooling device from the duct in which the cooler is located. 16 Claims, 11 Drawing: Figures SHEET 2 OF 2 PATENTEDHAY 7 1914 Fig. 2d Fig. 2e Fig. 2c @Blk 5 Fig. 2b Fig. 2a . 1 AIR HEATING AND COOLING SYSTEMFOR A VEHICLE PASSENGER CDMPARTMENT This invention relatestoa'n airheatingand cooling system for motor vehicles and moreparticularly to a system in which at least one cooling and at least one heating device, .in each case preferably heat exchangers, are associated withparallel connectediducts of. an air duct system through which air-is supplied to the passenger compartment of the vehicle at .a temperature regulated by a control device that suitablymixesthe air flowing through the parallel ducts. Air heating and cooling systems for vehicles are known in which air supplied by a blower isapportioned by a mixing valve to two parallel ducts, in one of which is located a heating device and in the other a cooling device, the apportionment being controlledin response to the temperature of the air supplied to the passenger compartment. In this known type of heating and coolin g system, warmed air is delivered exclusively to an orifice in the foot space of the vehicle, while cooled air is led to special discharge openings in the dashboard of the vehicle. Another kind of air heating and cooling system is known in which the airsupplied by the blower is first passed through a cooler and then through a heater and only thereafter distributed to the various ducts leading to the individual air discharge openings in the passenger space of the vehicle. The temperature of the air reaching the vehicle interior in this system is controlled by valves which regulate the operation of the heateror the cooler, as the case may be. Still another type of air heating and cooling system for vehicles is known in which the air supplied by the blower is first passed through a cooler and then distributed to two air ducts. A heat exchanger serving as a heater is associated with one of these two parallel air ducts. In this case the temperature of the air delivered to the passenger compartment is controlled by a mixing valve which varies the proportion of air flowing through the parallel ducts. In all of these known vehicle air heating and cooling systems, the disadvantage has resulted that when the outer air temperature lies in the range between about +10 to about +30C, hence during the larger portion of SUBJECT MATTER OF THE PRESENT INVENTION Briefly, air is supplied to three branch air ducts, in one of which the air may be heated, in a second of which it may be cooled and in the third of which the air temperature is not changed. A control device is provided for mixing the air supplied by these three ducts for delivery to the passenger space; and in accordance with a particularly advantageous form of the invention, the mixing is applied to the output of only two of the three ducts at the same time, in each case mixing two airstreams of different temperatures, one of these two air streams always being the stream of which the temperature is not changed. In a preferredformofthe invention thecontrol device isa slide or gate valve, suchas arotary slide valve withfixed and movable aperturesbywhich therate of discharge of air from the respectiveaforesaid branch ducts'to the passenger space of the vehicle can be controlled. In another preferred form of the invention, the control deviceincludes a cylinder valve with adiametral passage. The invention will be desc'ribed. by way of example with reference tothe accompanying drawings, wherein: FIG. 1 is a perspective view,'w.ith certain elements shownin diagram, of an airheating and cooling system in accordance with the invention; FIG. 2 shows diagrammatic representations of the position of the control valve of the system under-different conditions of operation, and *FIG. 3 shows diagrammaticallydifferent mixing positions of an air heating and cooling. system with a differblower 3 is located. The air flowing through the main duct 2 is distributed to three ducts 4, 5 and 6 disposed parallel and adjacent to each other. A flap valve 7 in the main duct 2 near where it feeds the branch ducts 4, 5 and 6 is provided inorder to control the overall rate of air movement in the system. Outside air flows through the duct 4, which is at the left in FIG. 1, without its temperature being changed. A heat exchanger 8, which may for example be the evaporator of a cooling system serves as a cooler by which the air flowing in duct 6 may be cooled. In the duct 5, which is the central one of the three parallel ducts as shown in FIG. 1,.a heat exchanger 9 serving as. a heater is provided. When the evaporator 8 is turned on, air flowing through the duct 6 comes out at a temperature lower than that of the outside air. When the heater 9 is turned on, air flowing through the duct 5 comes out warmer than the outside air. ' The three parallel ducts 4, 5 and 6am closed off at the bottom by a partition 10 in which three apertures 11, 12and 13 are provided arrangedin the form -ofsegments cut out of an annular area of the partition 10 defined by two concentric circles. These apertures provide the respective discharge openings of the three ducts 4, 5 and 6. A slide valve 15 of the rotary disc type is mounted by a suitably bearing on the partition 10 so as to be rotatable about the axis A--A. This rotary slide valve 15 has two apertures l6 and 17 corresponding in shape to that of the discharge openings 11, 12 and 13 of the air ducts 4, 5 and 6. In the embodiment of the invention illustrated in 3 lies exactly between the openings of the other two ducts. I In FIGS. 2a, 2b 2e diagrammatic plan view of the rotary slide valve for different switching positions are shown. The annular segments shown in dashed lines represent the openings ll, 12 and 13 in the horizontal partition 10. The annular segments drawn in solid lines represent the apertures 16 and 17 in the disc of the rotary slide valve 15. FIG. 2a shows a position of the rotary slide valve in which the aperture 17 of the disc registers with the discharge opening 12 of the air duct 5, through which warmed air flows. In this case this warmed air can flow in the air duct 14, whence it is distributed, by means not shown in the drawing, to the individual air discharge openings in the passenger compartment of the vehicle. At this time the other two duct discharge openings 11 and 13, however, are sealed shut. For this position of the slide valve, accordingly, only warm air is delivered by the system to the passenger compartment. In FIG. 2b the rotary slide valve 15 is shown in a position in which the apertures 16 and 17 partly register with the discharge openings 11 and 12 respectively of the partition 10. In this condition of the system the outside air, on the one hand, and warmed air, on the other, are supplied to the air duct 14, where these two air streams are mixed. The air flowing into the passenger compartment is therefore cooler than in the condition of the system shown in FIG. 2a. In the situation shown in FIG. 20 only the air duct 4 is opened, since the aperture 16 registers with the discharge opening 11 of that duct, so that only outside air can flow in the duct 14 and from there into the passenger compartment. In the situation shown in FIG. 2d the apertures 16 and 17 lie partly in registry with the discharge openings 11 and 13 respectively, of the horizontal partition 10. Accordingly outside air, on the one hand, and air cooled by the evaporator 8, on the other hand, flow into the passenger compartment of the vehicle. In the condition of the system shown in FIG. 2e, however, only air duct 6 is opened, so that only cooled air can flow into the passenger compartment. It will thus be seen that a rotation of the rotary slide valve in a counter clockwise direction, beginning from the position shown in FIG. 2a, the air delivered to the passenger compartment of the vehicle becomes steadily cooler, this effect being provided by the progressive closing and opening of the air ducts 5, 4 and 6 (in that order) by the rotary valve 15, in such a way that the next in sequence is progressively opened as the one previously opened is progressively closed. In other words, the output of duct 4 is regulated with respect to the output of either duct 5 or duct 6 in an inversely proportional manner. Another illustrative embodiment of the invention in an air heating and cooling system is shown in FIG. 3, where FIGS. 3a, 3b 3e diagrammatically show different conditions of the system. Here again there is a main duct 2 in which air flow is produced by a blower 3. The main duct 2 branches, again, into three ducts 4, 5 and 6. The arrangement this time is not geometrically parallel, but from a system point of view the ducts may be regarded as in principal parallel. That is, they are supplied in parallel and they discharge, except for interruption by valving, in parallel, from the point of view of an air flow circuit. In this case the discharge 4 openings 11, 12 and 13 of the three air ducts 4, 5 and 6 are immediately adjacent to each other and the discharge portion of these ducts converge in such a manner that a valve cylinder 20, provided with a diametral passage 21, may serve as the control device of the system. The passage 21 has a rectangular cross section the dimensions of which approximately correspond to the substantially identical cross sections of the discharge openings of the three air ducts 4, 5 and 5. Corresponding reference numerals are used in FIG. 3 and FIG. 2 for the ducts 4, 5 and 6 and for the discharge openings 11, 12 and 13, as well as for the cooler 8 and the heater 9. It will therefore be seen that the condition of the system represented in FIG. 3a corresponds to that shown for the other embodiment in FIG. 2a and the same applies for FIGS. 3b and 2b, FIGS. 30 and 2c, FIGS. 3d and 2d and FIGS. 3e and 2e. It may accordingly beseen from the positions of the cylinder 20 in FIGS. 3a, 3b 3e, that in this system also the air supplied to the passenger compartment can be gradually changed from hot to cold when the cylinder is turned, clockwise beginning from the position shown in FIG. 3a. In the situation shown in FIG. 3 only air warmed by the heating element 9 is delivered to the passenger compartment, whereas under the conditions illustrated in FIG. 3b both warm air and unheated outside air can flow into the passenger space. In the case of FIG. 30, orily unchanged'outside air flows into the car interior, while in the situation shown in FIG. 3d, in part cooled air and in part unaffected outside air are supplied. Finally, in the situation shown in F IG. 3e, only cooled air is supplied by the system to the passenger compartmenLThe individual air streams in use in the various cases are indicated in the diagrams of FIG. 3 by arrows. Both of the described embodiments of the invention are particularly effective as fully regulated heating and cooling systems. In a fully regulated air control system the air delivery temperature should depend as linearly as possible on the control valve position, a condition that can be accomplished in the case of the two described control devices very easily by modifying the shape of the apertures 16 and 17 in'the disc of the rotary gate valve 15 or by modifying the shape or dimensions of the passage 21 of the valve cylinder 20. By rotation of the rotary slide valve 15 or of the valve cylinder 20, as the case may be, the air delivery temperature can accordingly be continuously changed from cooling to heating over the whole range of movement of the control device, an effect that is not so easy to realize, as has heretofore been appreciated, with a variety of conventional valve arrangements. In the air heating and cooling systems here described, as is particularly clear from FIGS. 2 and 3, there are never more than two air streams mixed with each other, and one of them is always the air stream the temperature'of which is that of the outside air. In systems of this sort, therefore, only one of the two heat exchangers needs to be used at any one time. The rotary slide valve 15 or the valve cylinder 20, as the case may be, serving as the control device of the system is preferably driven by an electric motor (not shown). It is, however possible, to provide manual control with a flexible cable linkage or a rack and pinion linkage, or a control utilizing a vacuum box or a device using an expansible material. In the case of an air heating and cooling system having still further control devices affecting the temperature or the rate of flow of the air stream delivered to the passenger compartment, as for example a stepwise ventilator control and/or a valve for selecting between closed circulation of air and fresh air input, usually with possibility of adjusting the proportion of fresh air input, all involved in the regulation task, it is advantageous to constitute the regulation system in such a manner that the regulating device merely affects the positioning of the rotary slide valve or the valve cylinder 20, as the case may be, while all the other control devices above mentioned are actuated in accordance with the position of the rotary slide valve 15 or the cylinder valve by means of cable actuators or similar arrangements. That is possible inthe case of systems of the present invention because of the fact that the control device is so constituted that for every temperature setting for the air flowing into the passenger compartment there is an exactly defined position of the control device distinguishable from all other possible positions that it may have. In previously known systems control devices of flap valve form that was not possible because a particular air delivery temperature could be equally well provided by two or more settings of the flap valve. By way of example there is shown in FIG. I an electronic regulating system comprising a manual setting device for providing a desired temperature setting, a temperature sensor 26 for measuring the temperature of the passenger compartment, a temperature sensor 27 for measuring the temperature of the air delivered by the system and a regulator apparatus 28. The regulator 28 controls the position of the rotary slide valve 15 as a function of the measured and: prescribed magnitudes. The disc of the rotary slide valve 15 has a drive stud 29 which actuates the air intake flap valve 7 by means of a cable connection 30. The actuating stud 29 can also be arranged to control the valves of the heat exchangers and, if desired, also air distribution valves. The regulator 28 is concerned, therefore, only for the proper setting of the rotary slide valve and allthe other control devices of the air heating and cooling system are controlled in accordance with the position of the rotary slide valve 15. v r The air heating and cooling system of the present invention is relatively simple to build 'and very easy to regulate. It has a very high reliability in operation, moreover, since for the output temperature adjustment, instead of a number of valves, only one movable part, i.e., a rotary slide valve or a cylinder valve, is provided. lt willbe noted that as shown both in FIG.'1 and in FIG. 3, the air passing through duct 5 and hence also through the heater 9 also passes throughthe cooler 8, which of course is inactive when the heater-9 is operating. In other words the duct Sis branched ofi from the duct 6 downstream of the cooler 8. This slight deviation from ordinary parallel branching of the three ducts makes it possible to provide the cooling heat exchanger surface in a form offering relatively little resistance toas a heater can have longer passages and. smaller crosssection and the reduced flow of hot air as compared to the flow of cool air does not prevent reaching a sufficiently high heatingcapacity. It is to be understood that the references herein to parallel ducts are meant in 'a very broad sense. It is clear that in any event the two ducts through which at any one time air is concurrently flowing are being fed and discharged in parallel. In the embodiments of thei'nvention above described three parallel brand ducts are provided,one equipped with a heater, one with a cooler and another with no heat exchanger of either type. The mixing valve is shown so arranged that air from either the heating branch 5 or the cooling branch 6 iseither used along or is mixed in some proportion with air from the unchanged air duct 4. ltwill be seen, however, that the principle of the invention is not limited to these valving schemes, nor to the mixing of air flows from only two ducts at a time. The third duct has its heat exchanger shut off in each case, so that it can perfectly well function as part, or even all, of the passage'for unchanged air, if the valving program is modified accordingly. For example, when the heating element 9 is turned off cooled air from the duct '6 can be mixed with unchanged air from either or both of ducts 4 and 5, whereas when the cooler 8 is turned off the heated air from the duct 5 can be mixed with unchanged air from either or both of ducts 4 and 6. The presence of the duct 4 is thus not strictly necessary for the practice of the invention, but it is a practical convenience because of its low flow resistance that permits a relatively large volume of air to be moved easily through a physically small structure when a small heating or cooling effect under close control is desired. Although the invention has been described with respect to two particular embodiments, it will be understood that variations and modifications are possible within the inventive concept without departing from the spirit of the invention. We claim: 1. An air heating and cooling system for the passenger compartment of a motor vehicle comprising: first, second andthird ducts (4, 5 and 6) arranged to be supplied with air from a commonair supply and adapted" to guide the flow of air streamsbranching from said air supply; heating means for heating air passing through said first duct (6 r l cooling means for cooling 'air passingthrough said second duct (5'); g said third duct (4) being adaptedto transmit air without change of temperature, and temperatureresponsive meansfor selecting for deliveryto saidpassenger compartment a flow of air exiting from said first, said second or said third duct alone or from anycombination thereof. 2. An air heating and cooling system-as defined in claim 1 in; which said temperature responsive means (15, 20) is arrangedto provide for mixing air only two of saidair streams at a time and in each case air from said third duct (4)is caused to passbyvsaid temperature responsive means. 3*. An air heating and cooling system as defined in claim 2 in which said temperature responsivemeansineludes agate valve (15) by which the proportion of air I from said -first, second andthird ducts (4, 5 and6) supplied to said passenger compartment is controllable. 4; An air heating:andcoolingsystern as defined in claim3in which saidgatevalve (15) isadapted to shut down or open up'said' ducts (4, Sand *6) two at atime in inversely proportionalfashion". 5. An air heating and cooling system as defined in claim 4 in which the discharge openings (ll, 12 and 13), respectively provided for said ducts, are arranged in an equally spaced series and in which said gate valve (15) is provided with a slide having two apertures (16, 17) the spacing between which is greater than the spacing of two adjacent discharge openings of said respective ducts (4, 5 and 6). 6. An air heating and cooling system as defined in claim 5 in which the shape of said duct discharge openings (1 1, 12 and 13) is similar to the shape of said apertures (16, 17) in said slide of said gate valve (15). 7. An air heating and cooling system as defined in claim 6 in which the shape of the surface between said discharge openings (11, 12) of two of said ducts (4, 5) have the same shape as one of said duct discharge openings. 8. An air heating and cooling system as defined in claim 7 in which said slide of said gate valve (15) has two apertures (16, 17) so spaced from each other that one of said ducts (4) is opened by one of said apertures (16) when the other of said apertures (17) said slide of said gate valve (15) lies exactly between the openings (12, 13) of the other two of said ducts (5, 6). ' 9. An air heating and cooling system as defined in claim 5 in which said temperature responsive means includes a rotary slide gate valve (15). 10. An air heating and cooling system as defined in claim 9 in which said discharge openings (11, 12 and 13) of said three ducts (4, 5 and 6) are disposed on said slide of said rotary slide gate valve (15) with the centers of adjacent openings relatively displaced by 90 with reference to the axis of rotation (A-A) of said rotary slide. 11. An air heating and cooling system as defined in claim 10 in which said dischargeopenings (11, 12 and 13) of said three ducts (4, 5 and 6) have the shape of segments of a circular annulus. 12. An air heating and cooling system as defined in 8 claim 2 in which discharge openings (11, 12 and 13) are provided for said three ducts (4, 5 and 6) immediately adjacent to each other and in which said temperature responsive means includes a valve cylinder (20) with a diametral passage (21). 13. An air heating and cooling system as defined in claim 12 in which the respective cross sections of said discharge openings (11, 12 and 13) of said three ducts (4, 5 and 6) are at least approximately of the same magnitude and at least'approximately correspond in shape to the cross section of said passage (21) through said valve cylinder '(20). 14. An air heating and cooling system as defined in claim 13 in which said passage (21) through said valve cylinder (20) has a rectangular cross section. 15. An air heating and cooling system as defined in claim 1 in which the movement of said temperature responsive means is adapted to change the temperature of the delivered air continuously between a minimum and a maximum value. 16. An air heating and cooling system for the passenger compartment of a motor vehicle comprising: a plurality of ducts, including a first duct (5) equipped with air heating means (9), a second duct (6) equipped with air cooling means (8), and a third duct (4) having no air heating or cooling means provided therein, said ducts being arranged to be supplied with air from a common air supply; means for selectively enabling or disabling said heating and cooling means respectively according to whether heating or cooling is desired, and temperature responsive means for selecting a flow of air exiting from one or more of said plurality of ducts for delivery to said passenger compartment in such a way as to tend to maintain a desired temperature in said passenger compartment. 1. An air heating and cooling system for the passenger compartment of a motor vehicle comprising: first, second and third ducts (4, 5 and 6) arranged to be supplied with air from a common air supply and adapted to guide the flow of air streams branching from said air supply; heating means for heating air passing through said first duct (6); cooling means for cooling air passing through said second duct (5); said third duct (4) being adapted to transmit air without change of temperature, and temperature responsive means for selecting for delivery to said passenger compartment a flow of air exiting from said first, said second or said third duct alone or from any combination thereof. 2. An air heating and cooling system as defined in claim 1 in which said temperature responsive means (15, 20) is arranged to provide for mixing air only two of said air streams at a time and in each case air from said third duct (4) is caused to pass by said temperature responsive means. 3. An air heating and cooling system as defined in claim 2 in which said temperature responsive means includes a gate valve (15) by which the proportion of air from said first, second and third ducts (4, 5 and 6) supplied to said passenger compartment is controllable. 4. An air heating and cooling system as defined in claim 3 in which said gate valve (15) is adapted to shut down or open up said ducts (4, 5 and 6) two at a time in inversely proportional fashion. 5. An air heating and cooling system as defined in claim 4 in which the discharge openings (11, 12 and 13), respectively provided for said ducts, are arranged in an equally spaced series and in which said gate valve (15) is provided with a slide having two apertures (16, 17) the spacing between which is greater than the spacing of two adjacent discharge openings of said respective ducts (4, 5 and 6). 6. An air heating and cooling system as defined in claim 5 in which the shape of said duct discharge openings (11, 12 and 13) is similar to the shape of said apertures (16, 17) in said slide of said gate valve (15). 7. An air heating and cooling system as defined in claim 6 in which the shape of the surface between said discharge openings (11, 12) of two of said ducts (4, 5) have the same shape as one of said duct discharge openings. 8. An air heating and cooling system as defined in claim 7 in which said slide of said gate valve (15) has two apertures (16, 17) so spaced from each other that one of said ducts (4) is opened by one of said apertures (16) when the other of said apertures (17) said slide of said gate valve (15) lies exactly between the openings (12, 13) of the other two of said ducts (5, 6). 9. An air heating and cooling system as defined in claim 5 in which said temperature responsive means includes a rotary slide gate valve (15). 10. An air heating and cooling system as defined in claim 9 in which said discharge openings (11, 12 and 13) of said three ducts (4, 5 and 6) are disposed on said slide of said rotary slide gate valve (15) with the centers of adjacent openings relatively displaced by 90* with reference to the axis of rotation (A-A) of said rotary slide. 11. An air heating and cooling system as defined in claim 10 in which said discharge openings (11, 12 and 13) of said three ducts (4, 5 and 6) have the shape of segments oF a circular annulus. 12. An air heating and cooling system as defined in claim 2 in which discharge openings (11, 12 and 13) are provided for said three ducts (4, 5 and 6) immediately adjacent to each other and in which said temperature responsive means includes a valve cylinder (20) with a diametral passage (21). 13. An air heating and cooling system as defined in claim 12 in which the respective cross sections of said discharge openings (11, 12 and 13) of said three ducts (4, 5 and 6) are at least approximately of the same magnitude and at least approximately correspond in shape to the cross section of said passage (21) through said valve cylinder (20). 14. An air heating and cooling system as defined in claim 13 in which said passage (21) through said valve cylinder (20) has a rectangular cross section. 15. An air heating and cooling system as defined in claim 1 in which the movement of said temperature responsive means is adapted to change the temperature of the delivered air continuously between a minimum and a maximum value. 16. An air heating and cooling system for the passenger compartment of a motor vehicle comprising: a plurality of ducts, including a first duct (5) equipped with air heating means (9), a second duct (6) equipped with air cooling means (8), and a third duct (4) having no air heating or cooling means provided therein, said ducts being arranged to be supplied with air from a common air supply; means for selectively enabling or disabling said heating and cooling means respectively according to whether heating or cooling is desired, and temperature responsive means for selecting a flow of air exiting from one or more of said plurality of ducts for delivery to said passenger compartment in such a way as to tend to maintain a desired temperature in said passenger compartment.

1973-03-07

en

1974-05-07

US-41456173-A

2-Amino-1-(2-imidazolin-2-yl)-2-imidazolines ABSTRACT The present invention relates to 2-amino-1-(2-imidazolin-2-yl)2-imidazolines, the free base of which has the following structural formulas: WHEREIN R1 is hydrogen, lower alkyl, cycloaklyl, aryl, substituted aryl, heterocyclic, substituted heterocyclic or aryloxy; R2 is hydrogen, lower alkyl, aryl and substituted aryl; or R1 and R2 taken together with the nitrogen atom to which they are attached form a heterocyclic ring; R3 and R4 are hydrogen, lower alkyl, aryl, or substituted aryl; R5 is hydrogen, lower alkyl, aryl or substituted aryl; N IS AN INTEGER FROM 0 TO 10. The compounds of this invention are useful as antiarrhythmic agents as well as antibacterial agents. United States Patent [1 1 Wittekind et al. [ Dec. 16, 1975 [54] 2-AMlNO-l-(2-IMIDAZOLIN-2-YL)-2- IMIDAZOLINES [75] Inventors: Raymond R. Wittekind, Morristown; John Shavel, Jr., Mendham, both of NJ. [73] Assignee: Warner-Lambert Company, Morris Plains, NJ. 22 Filed: Nov. 7, 1973 21 Appl. No.: 414,561 Related U.S. Application Data [60] Division of Ser. No. 253,074, May 15, 1972, Pat. No. 3,798,232, and a continuation-in-part of Ser. No. 6,639, Jan. 28, 1970, Pat. No. 3,666,767. [52] US. Cl. 260/309.6 [51] Int. Cl. C07D 49/34 [58] Field of Search 260/309.6, 309.2 [56] References Cited UNITED STATES PATENTS 2,987,522 6/1961 Shen 260/309.6 3,467,668 9/1969 Gruber et al. 260/309.6 3,666,767 5/1972 Wittekind et al. 260/296 R 3,798,232 3/1974 Wittekind et al. 260/309.6 3,803,157 4/1974 Wittekind et al. 260/296 R 3,806,518 4/1974 Wittekind et al. 260/309.6 Primary ExaminerEthel G. Love Attorney, Agent, or Firm-Albert H. Graddis; Frank S. Chow [57] ABSTRACT The present invention relates to 2-amino-l (2- imidazolin-2-yl)-2-imidazolines, the free base of which has the following structural formulas: 1 Claim, No Drawings R is hydrogen, lower alkyl, cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, or aryloxy; I R is hydrogen, lower alkyl, aryl, substituted aryl, or R and R taken together with the nitrogen atom to which they are attached form a heterocyclic ring, for example, a 5- or 6-membered ring; R and R are hydrogen, lower alkyl, aryl or substituted aryl; R is hydrogen, lower alkyl, aryl or substituted aryl; n is an integer from to 10. v In the definitions for R R R R and R the term lower alkyl includes aliphatic hydrocarbons having 1 to carbon atoms in the carbon chain. It includes straight chain as well as branched chain radicals. The term also includes, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl and the like. The term cycloalkyl encompasses saturated monocyclic groups having from 3 to 8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. The term heterocyclic encompasses the monocyclic 5- and 6-membered hetero rings having at least one hetero atom in the ring which may be either nitrogen, oxygen or sulfur. Representative heterocyclics falling within this definition are, for example, aziridinyl, azetidinyl, pyrrolyl, pyrrolidinyl, morpholino, thienyl, fury], pyridyl, piperidyl, indolyl, and the like. Additionally, these 5- and 6-membered heterocyclics may have further substituents in their ring'portions by groups such as, hydrogen, halogen, lower alkyl and lower alkoxy. The term aryl denotes a monocyclic or bicyclic hydrocarbon radical, preferably of 6 to 10 carbon atoms, such as for example, phenyl, naphthyl and the like. The term substituted aryl as used herein includes aryl as defined above in which one or more of the hydrogen atoms of the aryl portion have been substituted by groups such as, halogen, hydroxyl, lower alkyl, trifluoromethyl, amino, substituted amino or lower alkoxy. X, in the formulas below, includes anions suchas the halides, for example, fluoride, chloride, iodide, bromide, or other anions such as, sulfate, nitrate, phosphate, maleate, fumarate and the like. The definitions for R R R R, and R and n as used hereinafter have the same meanings as defined above. The compounds of this invention exhibit antiarrhythmic activity, for example, at a dosage of about 2 to 3 mg/kg, body weight in a mammal such as, cats, dogs, monkeys and the like. In experimentally induced arrhythmia, such as those induced by ouabain, at a dosage of 2 to 3 mg/kg, the compounds of this invention are capable of arresting such arrhythmia. Generally speaking, the compounds of this invention are useful in conditions associated with cardiac arrhythmia. A dosage level of about 1 to 10 mg, several times daily is recommended. This dosage regimen can be varied according to body weight, sex and species of the mammal being treated. Among the dosage forms which can be used to administer these compounds are, for example, tablets, powders, elixirs, suspensions and the like. These dosage forms are formulated by procedures known to the pharmacists art. All the compounds of this invention also exhibit antibacterial activity against gram positive cocci, such as Staphylococcus aureus or gram negative bacilli, such as E. coli. To use the compounds as anti-bacterials, they are formulated from 1 to 10% by weight with a dermatologically acceptable vehicle, such as talc, petrolatum and applied liberally to the site infected with the susceptible bacteria. The preferred genus of thiss invention is a compound of the structure: where R a heteroaromatic group such as furfuryl, 2-(3H- pyrazol-3-yl), 2-(4-imidazolyl), 5-methyl-l,3,4- thiadiazolyl, 2-benzimidazolyl, Z-benzthiazolyl, 3 4 2-thiaz0lyl, 2-(6-methoxypyridazinyl) 'and the like. hydroiodide 3 and triethyl[1-(2-imidazolin-2-yU-2- n to 3. imida z oliin-Z-yl-]ammonium iodide "hydroiodi'de meanionic g p such 85 halide, eate. fumarthanethiol 4 were prepared by the processes depicted ate and the like- 7 on page eight, where A has the same meaning as given These compounds are prepared as follows: above. A. 11-(011, -NH, I -sc11, R-(cn --NH & HA HA N4L NH NAN L l l .l g 11(c,11,),A' Z a -c11,s11 Nll 'llA l .l where R, n and A have the same meaning as above. 2-Methylmercaptoimidazol-2-ine 6 and the corre- 2-Propanol and acetonitrile are useful solvents for sponding salts 5 are prepared according to procedures these processes described in S. R. Aspinall and E. J. Bianco, J. Org. C/1em., 73, 602 1951 w. Wilson,J. C/1em.S0c., 1389 The amines 2 and their acid addition salts are avail- (1955) and A. L. Langis and F. Herr, Can. 736, 494 able from Aldrich Chemical Company and can be pre- (June 14, 1966), CA, 65, l22l2 (1966). N N N 5011 5011, sc11 3 'HA N HA 11 11 n uu N I N Z (C=H=)3N *9 (0,11, 3 N I 1 1 1 11 N11 L l 2 i pared by methods outlined in Synthetic Organic Chem- 2- Propanol and-.acetonitrile are useful solvents for ism-y by R. B. Wagner and H. D. Zook. John Wiley and these processes. v Sons, Inc, New York, N.Y., 1953. p. 653 and p. 832. To further illustratethe practice of this invention. the l-(2-lmidazolin-2-yl)-2-(methylthio)-2-imidazoline following examples are included: EXAMPLE 1 2(Furfurylamino)-1-(2-imidazolin-2-yl)-2-imidazoline Hydroiodide A solution of furfurylamine (11.6 g, 0.120 mole), 1-( 2-imidazolin-2-yl Z-methylthio )-2-imidazoline hydroiodide (37.1 g, 0.120 mole) and 2-propanol (300 ml) was heated under reflux for 1 hour during which time a steady stream of nitrogen was passed through the reaction mixture. The solution was allowed to cool to room temperature and the solid was collected. Recrystallization from 2-propanol (2 times) gave 14.6 g (34%) of the imidazoline, mp. 201202. Anal. Calcd for C H IN O: C, 36.58; H, 4.66; l, 35.14; N, 19.39; 0, 4.43. Found: C, 36.59; H, 4.44; I, 34.98; N, 19.09; 0, 4.72. EXAMPLE 2 1-( 2-lmidazolin-2-yl )-2- [2-( 3H-pyrazol-3-yl )ethyl- ]amino -2-imidazoline Dihydrochloride A solution of 2-(3H-pyrazol-3-y1)ethylamine 1 1.0 g, 0.0600 mole), 1-( 2-irnidazolin-2-yl )-2-( methylthio)-2- imidazoline hydrate (12.1 g, 0.0600 mole) and 2- propanol (180 ml) was heated under reflux for 3 hours while a steady stream of nitrogen was passed through the medium. The reaction mixture was allowed to cool to room temperature. The precipitate was collected. Recrystallization (2 times) from absolute ethanol gave 6.55 g (34.1%) of the imidazoline, mp. 292293. Anal. Calcd for C H C1 N C, 41.26; H, 5.98; C], 22.14; N, 30.65. Found C, 41.36; H, 6.05; Cl, 22.38; N, 30.78. EXAMPLE 3 1-( 2-lmidazolin-2-yl )-2- [2-( 4-imidazolyl )ethyl- ]amino -2-imidazoline Hydrochloride A solution of histamine dihydrochloride (22.1 g., 0.120 mole), 1-( 2-imidazolin-2-yl )-2-( methylthio )-2- imidazoline hydrate (24.2 g., 0.120 mole) and 2- propanol (400 ml.) was heated under reflux while a steady stream of nitrogen was passed through the medium. The reaction mixture was allowed to cool to room temperature. The solid was collected and recrystallized from ethanol (3 times); yield 4.52 g. (13.2%) of the imidazoline, mp. 192.0-193.0. Anal. Calcd. for C H ClN C, 46.54; H, 6.39; Cl, 12.49; N, 34.58. Found: C, 46.43; H, 6.24; C], 12.25; N, 34.72. EXAMPLE 4 2- l-(2-Imidaz0lin-2-yl)-2-imidazolin-2- yl]amino benzothiazole Hydrobromide Monohydrate. A solution of Z-aminobenzothiazole (22.5 g., 0.15 mole), l-( 2-imidazolin-2-yl )-2-( methylthio )-2- imidazoline hydroiodide (15.6 g., 0.15 mole) and acetonitrile (750 ml.) was heated under reflux for 20 hours during which time a stream of nitrogen was passed through the reaction mixture. The solution was allowed to cool to room temperature. The solid was collected and recrystallized from acetonitrilewater; yield 7.05 g. (11%) of the imidazoline, m.p. 305-307. Anal. Calcd for C H IN OS: C, 36.13; H, 3.96; l, 29.36; N, 19.44; S, 7.42. Found: C, 35.95; H, 4.14; l, 29.43; N, 19.51; S. 7.67. EXAMPLE 5 2- 1-( 2-lmidazolin-2-yl )-2-imidazolin-2-yl]amino -5- methyl-1 ,3 ,4-thiadiazole A solution of 2-amino-5-methyl-1,3,4-thiadiazole (8.06 g., 0.07 mole), 1-(2-imidazolin-2-yl)-2-(methylthio)-2-imidazoline hydroiodide 21.9 g. (0.07 mole) and acetonitrile (400 ml.) was heated under reflux for 3 days while a stream of nitrogen was passed through the reaction mixture. The solid was collected from the hot solution, and then dissolved in water (300 mL), basified with 2N sodium hydroxide solution and extracted with methylene chloride. The organic phase was dried over sodium sulfate, filtered and evaporated. v Recrystallization of the residue from acetone gave 1.86 g. (11%) of the imidazoline, m.p. l192. Anal. Calcd for C H N S: C, 43.01; H, 5.21; N, 39.01; S, 12.77. Found: C, 43.05; H, 5.12; N, 39.10; S, 12.73.- EXAMPLE 6 2- [l-(2-lmidazolin-2-yl)-2-imidazolin-2- yl]amino 'benzimidazole Hydroiodide. A mixture of 2-aminobenzimidazole (8.0 g, 0.060 mole), triethyl[ l-( 2-imidazolin-2-yl )-2-imidazolin-2- yl]ammonium iodide hydroiodide methanethiol (32.5 g, 0.0600 mole) and 2-propano1 (distilled from calcium hydride, 150 ml) was heated under reflux, with stirring, for 23 hours. A slow stream of nitrogen was bubbled through the reaction mixture during this time. The reaction mixture was allowed to cool to room temperature. The precipitate was collected and recrystallized from methanol; yield 2.9 g (12%) of the imidazoline hydroiodide, mp. 289.5290.0 dec. Anal. Calcd for C H N I: C, 39.31; H, 4.06; N, 24.68; I, 31.95. Found: C, 39.35; H, 4.16; N, 24.87; 1, 31.77. EXAMPLE 7 3- [1-(2-imidazolin-2-yl)-2-imidazolin-2-yl]amino -6- methoxypyridazine Hydroiodide A solution of 3-amino-6-methoxypyridazine (48.8 g., 0.400 mole), 1-(2-imidazolin-2-yl)-2-(methylthio)-2- imidazoline hydroiodide g., 0.400 mole) and acetonitrile (3 l.) was heated under reflux for 70 hours while a stream of nitrogen was passed through the reaction medium. The reaction mixture was allowed to cool to room temperature. The precipitate was collected and recrystallized from ethanol-water; yield 14.6 g. (9.0%) of the imidazoline hydroiodide, m.p. 249250. Anal. Cald. for C H IN O: C, 33.95; H, 4.14; l, 32.61; N, 25.19; 0, 4.11. Found: C, 33.87; H, 4.18; I, 32.87; N, 25.31; 0, 4.35. EXAMPLE 8 2- l-( 2-lmidazolin-2-yl)-2-imidazolin-2-yl]aminothiazole Hydroiodide 1. 1-(2-IMIDAZOLIN-2-YL)-2- (2-(4-IMIDAZOLYL)ETHYL)AMINO2-IMIDAZOLINE HYDROCHLORIDE.

1973-11-07

en

1975-12-16

US-74977376-A

Weight bearing treadle ABSTRACT An improved treadle for use in a compact, portable weighing scale comprising a load-bearing, pressure-developing displacement treadle connected to a volume-reacting, weight-indicating readout means. The treadle contains a first sealed collapsible chamber sealed at one end and communicating with the readout means at the other, and a second, fully sealed collapsible chamber not communicating with the readout means. The second sealed chamber improves the compression characteristics of the collapsible chamber. At least one collapsible chamber is preferably formed from flexible tubing which is reinforced with braiding. A treadle comprising two treadle plates, and a means of compacting same, are also disclosed. APPLICABILITY OF INVENTION The present invention is directed toward an improved treadle for use in a compact, portable weighing scale. More specifically, the invention concept herein described encompasses a personal portable weighing scale of a size which affords convenient storage, or carrying in a handbag, pocket, suitcase, or back pack. Therefore, although suitable for utilization within the household, the present "mini-scale" is ideally suited for use when away from home. The present invention improves upon, and is, therefore, closely related to my U.S. Pat. No. 3,985,191 (Cl. 177-208), issued Oct. 12, 1976, all the teachings of which are incorporated herein by reference thereto. Briefly, my previous invention is directed toward a portable mini-scale comprising a weight-bearing treadle formed by two spaced-apart, substantially parallel surfaces and containing a collapsible chamber. Communicating with the chamber is a conduit, preferably about 6 feet of small diameter flexible tubing for ease in eye-level observation of weight-indicating readout means connected to and communicating with the opposite end of the conduit. In operation, the weight of an object, or person on the treadle collapses the chamber which causes a compressed bellows in the readout means to expand in proportion. Expansion of the bellows actuates movement of a weight-indicating cylindrical scale. The present invention relates primarily to improvements in the weight-bearing treadle. The treadle disclosed in my prior patent consists of helical coils of flexible tubing disposed within two flat surfaces. A person stands on the treadle, and partially compresses the tubing, thereby causing fluid to be transmitted to the weight-indicating readout means. The device works well, but some deficiencies have been observed. With flexible tubing, such as Tygon tubing, the prolonged application of force causes the tubing to stretch, so that the indicated weight changes when someone remains on the scale for an extended length of time. Another problem is that uneven application of force causes the tubing to at least partially collapse, and thus be pinched shut. Pinched tubing, obviously, cannot transmit fluid to the readout means and erroneous weights may result. These problems are largely eliminated through the use of a closed portion of tubing, preferably filled with a fluid, to improve the elastic characteristics of the treadle. Preferably, a double helix of (1) closed tubing and (2) tubing open at one end to the readout means, will be used. The closed tubing acts as an elastic member and also functions to reinforce the side walls of the tubing which is connected to the readout means. Other improvements in the treadle include use of two treadle plates, and a better layout of the coils within the treadle, a way of folding the treadle plates wherein tabs are disposed at staggered loci on each treadle shroud to permit the tubing to the readout means to be wrapped around a channel formed by the plates and hold them in intimate contact, and use of flexible tubing containing braided reinforcement, incorporation of guards in the treadle surface to protect the tubing where joints are made, and incorporation of a hard cord or line inside the tubing to eliminate the possibility of pinching shut some portion of the tube. Accordingly, the present invention provides an improved weight bearing treadle comprising in cooperative combination: (a) at least one treadle plate; (b) a flexible tube disposed upon said plate and adapted to react to a weight, and wherein (i) said flexible tube is sealed at one end and, (ii) connectable to a readout means at the other end; and, (c) a resilient member contiguous with at least a portion of said flexible tube to provide side-wall support thereto when said flexible tube is compressed. SUMMARY OF THE INVENTION As hereinbefore stated, the present invention provides a compact, portable weighing scale improving upon that which is disclosed and defined in my prior U.S. Pat. No. 3,985,191. The most significant improvement over the operation of my prior patent is afforded by incorporation of two types of collapsible tubing within the treadle means. One portion of the tubing is open to the weight-indicating readout means. This tubing functions in a fashion similar to that of my prior patent. When weight is applied to the treadle, the tubing is compressed and fluid is displaced from the tubing to the readout means. One improvement is the incorporation of a second tube which is sealed at both ends. The function of the sealed tube is twofold: (1) to improve the elastic characteristics of the scale; and, (2) to provide a significant amount of side-wall support for the open tubing. It is not necessary for the sealed tubing to be equal in length to the open tubing, though such configuration comes within the scope of my invention. I have found that it is possible to obtain much improved operation by providing sealed tubing in contact with open tubing for even a single 360° spiral, when the open tubing is disposed as a spiral. When the open tubing is disposed within the treadle means as a series of back-and-forth, or reflex, loops the improved operation is obtained by providing at least on length of closed tubing, in contact with at least one loop along substantially its entire length. The sealed tubing may be similar in size and shape to the tubing open to the readout means. The sealed tubing may be filled with a compressible fluid, such as air, or an incompressible one, e.g., water. It is also within the scope of the present invention to provide a fluid within the sealed tubing which is under a pressure different from atmospheric, e.g., air at a total pressure of 1.15 atmospheres, absolute. It is also possible to use tubing which is solid, or which has a shape other than tubular. What is essential is that the sealed tubing provides side-wall support to the tubing open to the readout means, and also impart resiliency to the treadle. Another feature which improves the operation of the scale and which compliments the use of some closed tubing contiguous to the open tubing, is to provide braiding on the outside of the tubing. Any non-stretching braiding material can be used, and may be applied by conventional means. The function of the braiding is to provide additional support to the tubing to prevent excessive deformation under sustained stress. Many types of tubing which are suitable for use, such as Tygon tubing, tend to retain a deformed shape when force is applied to them for several minutes. This property is objectionable because it allows the tubing to remain collapsed, and this causes fluid to remain displaced from the open tubing to the readout means. This prevents fluid return to the treadle, so the following weighing may be incorrect. This hysteresis is undesirable in a scale. The braiding, or reinforcing material, may be applied only to the exterior of the tube, in which case it will provide support to the tube during compression and will prevent an increase in the tube's circumference. Alternatively, the braiding may be embedded wholly or partially within the tube wall to provide additional limited flexibility in the tube, when these properties are desirable. Another feature of the improved scale which complements the above feature is incorporation of rigid or semi-rigid guards to protect the tubing from crushing at joints. Points of severe stress occur wherever two portions of tubing must be joined together, or when tubing leaves the treadle. Tubing connectors are typically made of a semi-rigid material, and a tight friction fit may be used, at least initially, to join tubing to a tubing connector. There is a slight increase in diameter of the tubing as it slips over a tubing connector and the materials being dissimilarly deformed work differently under load so that the joint may leak. To protect these sensitive portions of the open tubing, a raised channel is preferably provided in the treadle plates. Yet another step in eliminating one of the minor problems encountered in my prior scale is incorporation of a closure prevention means within the open tubing. In one embodiment, this may take the form of a length of monofilament line, braided string, airway maintenance cord, or similar means within the tube connective with the readout means. The function of the closure prevention means is to make sure that even if excessive force is applied, it will be impossible to completely pinch shut the tubing, preventing flow to the readout means. Incorporation of a length of airway maintenance cord 1/16 inch diameter within a piece of braided Tygon tubing, 0.125 inch I.D. by 0.187 inch O.D., produces an assembly which cannot be pinched shut. Further improvements resulted after studies which indicated that my prior scale was, for some people, difficult to use. In the prior scale, only a single treadle was provided with a single coil of open tubing within. It was difficult for some people to balance on the treadle, on the balls of their feet, to insure a proper weight reading. The system worked well, and was reproducible, but many consumers would be unwilling to take the time necessary to acquire the proper technique for using the scale. In one embodiment, the scale of the present invention completely eliminates these difficulties. Thus, preferably two interconnected treadles are provided, one for each foot. When two treadles are employed, they should be closely aligned to facilitate ease in use. The use of tape hinges or other means to hold the two treadles together at the optimum distance significantly improves the accuracy of operation of the scale. I have also provided a unique means of compacting or folding the device for storage or travel. In some embodiments, the scale of the present invention will be used in conjunction with a readout means attached to a long flexible tube. The tube is long so that the readout means can be held at eye-level by the user. There is a problem in storing the long flexible tubing leading to the readout means when the scale is not in use. I have managed to solve this storage problem, and also provided a unique way of holding the superimposed treadle plates together. I provide on the treadles, or preferably on a shroud covering the bottom of the treadle plates, inclined attachment means which form either leg of a "V" frame, or trough, in which the long flexible tube to the readout means can be placed. Wrapping of the flexible tube into the "V" results in a closely held pair of treadle plates, with the tubing to the readout means also neatly stored in the channel formed by the circumference of the stacked treadles. The improved scale can use any readout means. The readout means disclosed in my prior patent consisted of a bellows, and helical rod used in conjunction with a weight-dimensioned indicating cylindrical scale. It would also be possible to use a very sensitive pressure gauge, or to let the fluid displaced from the open tube displace another fluid in a "U" tube, such as a "U" tube manometer. Another excellent readout means consist of a bellows similar to that used in my prior patent, but wherein the expansion of the bellows displaces a length of line connected to a rotary dial. In summary, any readout means capable of receiving an input of fluid flow and/or pressure, may be used with good results. The readout means forms no portion of the present invention. BRIEF DESCRIPTION OF THE DRAWING FIG. 1, is a plan view of the treadle assembly of one embodiment of the present invention. FIG. 2, is a broken-away view of the tubing showing the general position of a cord therein used in the treadle means and generally covered by the shroud. FIG. 3, is a sectional view of tubing used in the treadle subjected to compression showing airways held open within the tubing by cord. FIG. 4, is an enlarged, cross-sectional view of one portion of the treadle means showing the treadle in compression, with a compacting tab in a relief position and partially collapsed tube. FIG. 5, is a view of the treadle means compacted for traveling, showing the operation of the compacting tabs, crossed and cradling several turns of small diameter tube to the readout means. With reference now to FIG. 1, the treadle, indicated generally as 1, is shown in its open configuration. Two treadle plates 4 each contain dual spirals of tubing 3 used in conjunction with a partial spiral of sealed tubing 2. Tubing 3, as best shown in FIG. 2, contains a length of airway maintenance cord 13, which is similar to monofilament or braided line. The function of line 13 is to prevent complete collapse or pinching shut of tube 3. As best shown in FIG. 3, when this tubing is collapsed, a small triangular space 17 will be maintained on each side of the line 13, even when a great amount of pressure is exerted on the tube. FIG. 3 also indicates braiding material 14 wound around tube 3 used to reinforce the side walls of the tube. The helical configuration of the open and sealed tubes 3 and 2, respectively, can be maintained either by glueing them together, welding the tubing with heat, or by providing relatively tight containment of the spirals within shroud 10. Preferably, the spiral configuration is maintained by heating the tube formed into a spiral so that the plastic will "remember" its shape. It is, of course, possible to make a treadle means 1 without heat treating these spirals, but the production of the device is made somewhat more complicated because the tube tends to return to its original linear shape rather than stay naturally in a spiral or helix. The spacing between treadle plates 4 is maintained by tapes 5 which prevent the treadle plates from getting separated by more than the length of the tapes 5. Tapes 5 can be cloth, string, wire, bead chain, etc. In the embodiment shown, two spirals of tubing are used on each treadle plate 4. It would be possible to make one spiral of a different size than the other spiral on the treadle; but, for ease of manufacturing and use of the device, the spiral portions are preferably all the same size. Because two spirals are used on each treadle plate, there must be a way of connecting these two spirals so that fluid displaced, or pressure indication from the spirals can be transmitted to the readout means. Two lengths of open tubing 3 on each plate are connected via a "Y" fitting 6, which permits transmission of fluid and/or pressure from tubing 3 to tubing 11, which passes beyond the boundaries of treadle plate 4. Fitting 6 may also take the form of a "T". Tubing 11 may be identical to tubing 3, but preferably, tubing 11 is of reduced diameter and more flexible. To protect the tubing from extreme stress when a user stands improperly upon the treadle, ridges 7 and 8 are preferably provided to ensure that no crushing force will be applied to tubing 3 stretched over the openings of rigid "Y" fitting 6. Ridges 8 also serve to protect tubing 11 from being pinched shut, or subjected to extreme cutting pressure if user stands improperly on the treadle plate. The ridges also prevent fluid leakage around the joints, as previously discussed. It is necessary to transmit pressure and/or fluid flow generated from both of the dual spirals of tubing on each treadle plate 4. This is accomplished by transmitting the fluid, or pressure, in each tube 11 to "Y" fitting 16, which connects with tubing 12 going to the readout means. Tubing 12 is preferably minimal I.D. and similar to tubing 11. Within each shroud 10 are slits 15 permitting the insertion of tabs 9 for holding the treadle in a compacted state. The compacting means 9 are comprised of relatively stiff plastic tabs, held within shroud 10 by the connecting link either by interference fit, or with adhesive, or both. As shown in FIG. 4, the compacting means 9 offer almost no resistance to downward force applied to treadle plate 4 when the scale is in operation. This is a very important property of the compacting means 9 in that they will not interfere with the weighing process or the readout means nor deform. As shown in FIG. 5, the function of compacting means 9 is to provide intermittent flange support for winding tubing 12 about a channel when formed treadles are in the compacted position. Tubing 12 is thus neatly stored, while the two treadle plates 4 are held together by the interferring tabs 9, locked by the tubing which is generally quite lengthy to permit a user of the scale to hold the readout means at a position convenient for viewing. The compacting means 9 are staggered so that they form a V-shape, or V-trough, as shown in FIG. 5, to permit easy winding of tubing 12. Tubing 12 also locks tabs 9 due to the alternate direction of pull of tabs 9. FIG. 1 actually shows the treadle means in an upside down position. During normal use, the treadle means 1 would be flopped 180° and placed on a flat, hard surface. Treadle plates 4 would be on top. In the treadle means disclosed in my prior patent, it was necessary to balance the balls of the feet evenly upon the treadle. Because of the use of two treadle plates in the present invention, it is preferred for the user merely to place one foot on each treadle plate and stand normally. The best mode contemplated by me for practicing the present invention is as follows: Treadle plates molded about 0.062 inch thick, except for heavier ribs, shown as 7 and 8 in the drawing, are formed from polycarbonate, ABS, or some other similar shock resistant material in a rectangle, with rounded ends, about 7.5 inches by 2.5 inches. Two pieces of PVC tubing of 0.187 inch O.D. by 0.125 inch I.D., which have been braided with 150/10 fiber glass, double wrapped about a 0.060 inch lead, or about 16 wraps per inch in two directions, the ends fixed with solvent of the Cadco-SC 201 type or equivalent or simply clove hitched, were then prepared. These two lengths of tubing were cut and preformed to produce a helix with about a 2.0 inch O.D. by wrapping the tubing in a flat spiral, placing it in a suitable fixture, and immersing the tubing for 40 seconds in water at 100° C. The fixture containing the tubing is then removed from the water, cooled to room temperature, and the tubing removed. Two finished helices from a double flat helix. Both tubes which will comprise the double helix are open at this point. One of the tubes is completely sealed at both ends by placing of the ends over a steel stub heated to 116° C. for two to five seconds, and then flat clamped immediately upon removal so that about a 0.25 inch length is thermally sealed. The fluid trapped within the tube is air in this embodiment, at ambient pressure. The clamps can be removed after six minutes when the assembly has cooled to room temperature. The other tube is now straightened by insertion into a length of 0.375 inch I.D. tubing, and a fish wire is then inserted. One end of the fish wire is hooked to receive the end of a monofilament or braided line (Gadding's Ideal, size C, is preferred). The line is then drawn through to about 0.25 inch from the end of the tubing. One end of this tube is thermally sealed as above. The tube containing the fish line returns to its helical shape after removing from the 0.375 inch tube. The open end of the tube, containing the fish line, is coated internally with solvent and slipped over one leg of a "Y" connector. A second similar tube is likewise attached to the other leg of the "Y" in a reverse coiling direction, but in the same plane. The assembly is placed in a fixture holding the entire assembly in a position which allows the double sealed tubes to be interwound so that each turn of one tube is separated by a turn of the other type. Thus, open tube containing a length of fishing line, is alternated with tubing which is sealed at both ends. A fixture consisting of a small molded urethane sponge disc is wet with solvent and "stamped" onto the molded treadle plate and the circular affected areas allowed to reach a tack point. At that point in time, the fixture with prepared assembly of tubing is carefully located concentric with the curved ends of the molded plate and held in place for five minutes under an exhaust hood. The fixture is then removed leaving the assembly bonded to the plate. Preformed shrouds of sheet PVC are die cut to match the outline of the plate and extruded about 0.187 inch to accommodate and fit over the helices while leaving a flat area on a 0.25 inch rim provided with clearances for tubes and tapes. Prior to placement on the plate the rounded edges of the extruded portion are slit so that the blanked and formed tabs can be inserted through the slits up to the connecting link stops, which locate the tabs. Solvent is flowed between the link and the inner top of the shroud. Plates with assembled helices are aligned parallel and 1.5 inches apart being connected with two 0.020 inch thick by 0.50 inch width PVC strips 2.250 inches long. These strips are placed parallel across the gap between the plates and the ends joined to the plates with solvent and clamps. Small tubing, 0.031 inch I.D. by 0.093 inch O.D. has been made up into an assembly consisting of a 6 foot length 12 inserted into the tail of "Y" connector 16, and two three inch lengths inserted into each leg of the "Y" 16 after being wet with solvent. Now each short length is inserted into the tails of "Y" connectors 6 to complete the internal assembly of the treadles. Now the prepared shrouds are placed over each treadle assembly and solvent is flowed in the edges with an industrial hypodermic syringe to affix the shroud to the treadle plate. All of this is preferably done under an exhaust hood for safety. I claim as my invention: 1. A weight-bearing treadle having at least one substantially rigid horizontal plate and comprising, in cooperative relationship:(a) a reinforced, first flexible tube (i) disposed upon said horizontal plate and adapted to react compressively to a weight, and, (ii) sealed at one end thereof and connectable at the other end to a weight-read-out means; and, (b) a second flexible tube (i) sealed at both ends thereof and, (ii) in contiguous side-wall support relationship with at least a portion of said first flexible tube. 2. Treadle of claim 1 wherein said first flexible tube is reinforced with braid. 3. Treadle of claim 1 wherein said first flexible tube contains in the interior thereof a length of flexible relatively incompressible material. 4. The treadle of claim 1 further characterized in having two spaced-apart horizontal plates (i) each of which has disposed thereon said first and second flexible tubes, and, (ii) which are in co-planer relationship. 5. Treadle of claim 4 wherein the two treadle plates are hingedly connected by lengths of flexible tape. 6. Treadle of claim 4 wherein said first flexible tube comprises two helices symmetrically disposed upon each of said two treadle plates. 7. Treadle of claim 6 wherein each helix contains an interior helix of said second flexible tube encompassed by and contiguous with said first flexible tube. 8. Treadle of claim 6 wherein the flexible tubes of each of said double helices are joined together, within the perimeter of each treadle plate, by connection to a "Y" fitting, and wherein said tubes from each treadle plate are joined together between the treadle plates by connection to a "Y" fitting which is connectable to readout means, and wherein the tubing slipped over legs of the "Y" fitting within the perimeter of each treadle plate is located within rigid protective ridges on each treadle plate. 9. Treadle of claim 6 wherein each pair of double helices on each plate is covered by a protective shroud. 10. Treadle of claim 9 wherein compacting means are provided in said shroud consisting of at least four inclined tabs connected to said shroud and forming opposingly angled tabs which form a compacting means when said plates are in a closed, touching position, and wherein said tabs form a "V" shape, adapted to contain a length of flexible tubing thus maintaining said plates in a closed position.

1976-12-13

en

1978-04-25

US-4495793-A

Non-inflatable sealing cuff for tracheal tube and other cannula ABSTRACT The present invention discloses a sealing cuff for an elongated tubular cannula, for forming an adequate fluid seal between the cannula and a body passageway when the cannula is inserted into the passageway. The sealing cuff comprises a plurality of thin flexible resilient annular slit discs extending generally perpendicularly from the cannula with a rim having a diameter larger than the opening of the body passageway. The slit discs haves a series of slits extending generally radially outwardly to the rim, dividing the disc into annular sectors, so that when the cannula is inserted into the body passageway, each sector can independently bend, overlap and readily conform to the wall of the passageway. The sealing cuff further comprises a plurality of thin flexible resilient annular solid discs extending generally perpendicularly from the cannula and having a diameter smaller than that of the body passageway, and arranged alternately between said slit discs. The discs of the sealing cuff for use on a tracheal tube can be &#34;D-shaped&#34; to facilitate conforming to the shape of the trachea. BACKGROUND OF THE INVENTION The present invention relates to medical catheters and cannula, and more particularly to tracheal tubes. Tracheal tubes have been used for some time to administer anesthesia to a patient, and to provide a bypass supply of air or mixture of gases to a patient having an obstruction in the upper area of the throat. Tracheal tubes can be in the form of a long flexible endotracheal tube wherein the distal end can be inserted into the trachea through the nose or mouth of the patient, or can be a short curved tracheostomy tube wherein the distal end can be inserted into the trachea through a surgical incision in the neck of the patient. The proximal end of the tracheal tube remains outside the trachea in communication with ambient air to permit passage of such air into the trachea. The proximal end of the tracheal tube can also be attached to a respiratory device to assist the patient's breathing. The distal end typically includes an inflatable cuff as described in U.S. Pat. No. 3,659,612 which is inflated after the tube is positioned to provide a fluid seal between the distal end of the tube and the wall of the trachea. The inflatable cuff includes a thin film elastic balloon which is bonded around the tube, having an inflation line extending from the balloon to the proximal end of the tube, and can further include check valves, relief valves, and external bulb indicators to help maintain the desired pressure within the cuff. Excessive pressure in the cuff can cause severe damage to the wall of the trachea, and insufficient pressure can result in an inadequate seal. When the inflatable cuff is properly designed, manufactured, handled, and used, it performs a safe and effective fluid seal. A problem with the inflatable cuff is that the cuff and inflation line are costly and difficult to manufacture. Another problem is that the inflatable cuff is very delicate and easily damaged during handling and in use; any leak in the balloon, inflation line or check valve will allow the cuff to collapse and not provide an adequate seal. U.S. Pat. No. 3,659,611 discloses an early non-inflatable tracheal tube seal, in which the distal end of the device includes a series of three resilient, solid disc, silicon flanges to engage the wall of the trachea. An apparent problem with the solid disc flanges is that the discs must be larger than the trachea to insure an occluding seal, but the oversized discs cannot conform to a smaller opening without bending and buckling around the periphery of the disc. The bending and buckling around the periphery of the discs can result in an ineffective seal, and can result in stress concentrations which may produce excessive localized pressure on the tracheal wall. Other medical procedures often require placement and sealing of a small cannula or catheter within a body passageway, for example an arterial or venous catheter within a blood vessel. Such cannula may be difficult to seal and can require a "cut down" surgical procedure of the vessel, with clamps and sutures to adequately seal the cannula within the body passageway. It is a object of the present invention to provide a safe, effective, reliable and durable fluid sealing cuff between a cannula and a body passageway. It is another object to provide a non-inflatable sealing cuff for a tracheal tube which is not difficult and not expensive to manufacture; and safe, effective, reliable and durable in use. SUMMARY OF THE INVENTION The foregoing objects are accomplished by a sealing cuff for an elongated tubular cannula, for forming an adequate fluid seal between the cannula and a body passageway when the cannula is inserted into the passageway. The sealing cuff comprises a plurality of thin flexible resilient annular discs extending generally perpendicularly from the cannula with a rim having a diameter larger than the opening of the body passageway. The discs have a series of slits extending generally radially outwardly to the rim, dividing the rim into annular sectors, so that when the cannula is inserted into a body passageway, each sector can independently bend, overlap and readily conform to the wall of the passageway. Another embodiment of the sealing cuff further comprises a plurality of thin flexible resilient annular solid discs extending generally perpendicularly from the cannula and having a diameter smaller than that of the body passageway, and arranged alternately between said slit discs. The sealing cuff is particularly useful to seal tracheal tubes with the trachea of a patient. Another embodiment includes the discs having a D-shape to facilitate conforming to the shape of the trachea of a patient. BRIEF DESCRIPTION OF THE DRAWINGS While the novel features of the invention are set forth in the appended claims, the invention will be better understood along with other features thereof from the following detailed description taken in conjunction with the drawings in which: FIG. 1 is a front perspective view of the distal end of a tracheal tube illustrating one embodiment of the present invention; FIG. 2 is a sectional view taken along 2--2 of FIG. 1, which is slightly enlarged; FIG. 3 is a side elevational sectional view of a tracheostomy tube incorporating the present invention, inserted into the trachea of a patient; FIG. 4 is an enlarged detail view of the inscribed area 4--4 of FIG. 3; FIG. 5 is an exploded front prospective view illustrating another embodiment of the present invention; FIG. 6 is a plan view of FIG. 5 which is slightly enlarged; FIG. 7 is a side elevational sectional view of a tracheostomy tube incorporating the second embodiment of the invention, inserted into the trachea of a patient; FIG. 8 is an enlarged detail view of the inscribed area 8--8 of FIG. 7; FIG. 9 is a sectional view taken along 9--9 of FIG. 3 which is slightly enlarged to illustrate the trachea and esophagus; and FIG. 10 is a plan view of a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring first to FIGS. 1, 2 and 3, there is illustrated an example of a first embodiment of the present invention, as a sealing cuff 10 formed on the tubular cannula 12 of a tracheal tube. The tubular cannula has a distal end 14 which is to be inserted within the trachea 16 of a patient, and the sealing cuff is to provide an adequate fluid seal between the cannula and the wall of the trachea. The sealing cuff 10 comprises a plurality of slit sealing discs 20. The sealing discs are thin flexible resilient annular discs which extend generally perpendicularly from the distal end 14 of the cannula. The discs have a diameter larger than the opening of the trachea, and can be sized correspondingly with the various sizes of tracheal tubes. An example of a typical size of the disc is about 1.25 inch in diameter. A unique feature of the sealing disc 20 is a series of slits 22 which extend generally radially outwardly to the rim of the disc. The slits in the disc function to substantially improve the flexibility and conformability of the rim of the disc upon engagement with the wall of the trachea. As previously discussed, the diameter of such disc must be larger than the opening to be sealed; and upon engagement of a "solid" (prior art) disc within the smaller opening can result in wrinkling and buckling-of the rim and surface of the solid disc, which can preclude the desired seal and can create stress concentrations on the wall of the trachea. In addition, the shape of the trachea at the distal end of the positioned cannula is not usually round and can vary from oval to "D-shaped" (see FIG.9), and it can be quite difficult for a solid disc to conform and seal around such irregular shapes. The slits of the present invention divide the disc into annular sectors 24 in which the tips of each sector can independently bend, twist, and overlap with adjacent sectors, if necessary, to conform to the wall of the trachea. The number, spacing and length of the slits 22 are each variable to produce the desired flexibility, conformability, rigidity, seal pressure and durability of the discs of the sealing cuff. For some design applications, it may be desirable to have the slits extend from the base of the cannula 12 to the rim of the discs, with numerous tightly spaced sectors, for maximum flexibility (but which may be allow some fluid flow leakage through the slits). Other material thicknesses and selections may dictate slits which emanate from points between the cannula and the rim, for improved sealing features with perhaps fewer discs. The present embodiment of sealing cuff 10 provides adequate flexibility and fluid seal with about six to ten discs 20 formed of 0.003 inch thin silicon (or polyurethane, flexible polyvinylchloride or like polymer) having slits 22 extending about 0.1 inch, about every thirty-six degrees, forming about ten sectors 22, with each disc spaced adjacently about 0.1 inch apart on the distal end of the cannula. The slits 22 of the disc may be fabricated by shearing a "flush" slit between sectors, or can be a "clearance" slit (or a slot) having a few degrees, or a few thousands of an inch, of clearance between sectors. The clearance permits the sectors to be even more flexible, and can permit the tips of the sectors to conform to smaller shapes without overlapping, which can provide a better seal in certain applications. The slits can also be fabricated so that the slits extend from emanation points shaped as small apertures to facilitate flexibility of the sectors, and which terminates the slit and prevents the slits from tearing inwardly toward the cannula. It may be advantageous to arrange the discs 20 so that the slits 22 of adjacent discs are not in alignment. Such an arrangement will avoid direct leakage paths between adjacent discs, and even if there is some leakage between the slits, the leakage flow must meander between discs which would provide resistance to the leakage and result in a better seal. Referring particularly to FIG.3 and also to FIG.4, the tracheal tube with the sealing cuff 10 is shown positioned within the trachea 16 of a patient. The cannula 12 of the tracheal tube is shown as a tracheostomy tube of which the distal end 14 has been inserted into a stoma 26 created in the neck of the patient, and the proximal end 28 has been secured by a suitable neck flange 30 tied by a strap around the neck of the patient. The proximal end 28 is further attached to a respirator device 32 to facilitate breathing of the patient. The dashed lines 34 illustrate the analogy of cannula 12 as an elongated endotracheal tube of which the distal end 14 and sealing cuff 10 is inserted into the mouth and through the larynx 36 of a patient and similarly positioned within the trachea. Upon the initial insertion of the distal end 14 through the stoma 24 (or through the larynx 36), the flexible sealing discs 20 are naturally collapsed and compressed by the stoma until the distal end passes into the trachea; the resilient discs 20 then progressively return to their extended generally perpendicular configuration; however, the tips of sectors 24 of the split discs now engaqe and readily conform to the wall of the trachea 16 to provide an adequate sealing cuff around the cannula. The sealing cuff 10 as utilized on tracheal tubes does not require an absolute air-tight or liquid-tight seal of each disc with the tracheal wall. Respiration devices operate at a relatively low pressure of about 25 to 50 millimeters of mercury, to apply air and oxygen to the lungs of the patient. The sealing cuff 10 acts as a resistance occluder to any bypass flow around the distal end of the cannula, and the respirator gas follows the path of least resistance into the lungs. In some applications, only one or a few slit disc 20 may be sufficient to provide a barrier to bypass flow and to provide an adequate seal. Referring now to FIGS. 5, 6, 7 and 8 there is illustrated an example of another embodiment of the present invention as a sealing cuff 40 formed on the tubular cannula 42 of a tracheal tube. The sealing cuff 40 comprises a plurality of thin, flexible, resilient slit annular discs 44, extending generally perpendicularly from the distal end 46 of the cannula. The slit discs 44 include a series of unique slits 48 which extend generally radially outwardly to the rim of the disc, and divide the disc into annular sectors 50. The slit discs 40 with sectors 50 are similar in design and function, to the slit discs (20) discussed in reference to FIG.1. and are similarly spaced apart along the distal end of the cannula. The sealing cuff 40 further comprises a plurality of thin flexible resilient annular solid discs 52 extending generally perpendicularly from the distal end of the cannula. Each of the solid discs 52 are arranged adjacently to a slit disc 44 and spaced apart along the distal end of the cannula. The solid discs 52 greatly compliment the function of the slit disc 44 to provide an even more adequate and effective seal with the trachea. The solid discs can have a diameter similar to that of the slit disc to seal against the wall of the trachea in the traditional manner. However, it is preferable that the diameter of the solid disc be smaller than the diameter of the slit disc, and even smaller than the opening of the passageway to be occluded. The reduced diameter solid discs have limited engagement with the wall of the trachea, and therefore are not usually wrinkled or buckled, and retain their perpendicular orientation between the slit discs. The slits discs flex, bend and conform to the contour of the wall of the trachea and reliably block and prevent any leakage paths around the sealing cuff, but the slits 48 can sometimes permit leak paths through the slit discs of the sealing cuff; while the solid discs may allow leakage around the discs but reliably block and prevent any leak paths through the body of the sealing cuff. The combination of the alternate slit disc and solid disc provides a labyrinth path for any leakage to alternately travel through a slit disc, then around a solid disc throughout the sealing cuff to therefore provide an excellent barrier to bypass flow and an adequate seal with the trachea. The solid discs also tend to support and align any slit discs that may become misaligned during handling or during installation of the tube. The selection of the thickness, diameters, materials, slit depth and pattern of the slit discs; and the thickness, materials, and the diameter of the solid discs; plus the relative spacing, orientation and arrangement of the discs along the cannula can each be varied in numerous combinations to provide an adequate seal of almost any cannula within any body passageway. It was found that an excellent seal was provided on a tracheal tube utilizing about six slit discs 44 of 0.003 inch thin silicon having a diameter of about 1.25 inches, with each disc having slits of about 0.1 inch arranged about every 36 degrees dividing the disc into about ten sectors; and utilizing about five solid discs 52 having a diameter of about 1.0 inch with the solid discs arranged alternately between the slit discs and spaced adjacently about 0.1 inch apart along the distal end of the cannula. Referring now to FIGS. 9 and 10, there is shown a cross section of the trachea 16, also showing the esophagus 54 separated by the tracheal membrane 56 to illustrate the typical "D-shaped" tracheal opening. FIG. 10 illustrates a third embodiment of a sealing cuff having a sealing disc 58 specifically designed to conform to the D-shaped opening of the trachea, and is otherwise similar to the slit disc and solid disc components as described in reference to FIGS. 5,6,7, and 8. While specific embodiments and examples of the present invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the spirit and scope of the invention. For example, the sealing discs of the present invention are described as extending "generally perpendicularly" from the cannula. In some applications of the sealing cuff, some or all of the discs may be fabricated having an angled or conical configuration; perhaps to facilitate insertion, or perhaps with a reverse angle conical configuration so that any bypass flow would tend to increase the engagement force of the sealing discs against the passageway for an improved seal. The term generally perpendicularly shall apply to such angled and conical configurations of the discs. Similarly, the term "generally radially" outwardly shall apply to slits which may be oriented at an angle or spiral or other such path to the rim of the discs. The term "discs" shall apply to discs which are circular, oval, D-shaped or customized in shape to fit a specific contour or body passageway; and shall apply to discs which are flat, tapered, or corrugated for a specific application. What is claimed: 1. A sealing cuff on an elongated tubular cannula, for forming an adequate fluid seal between the cannula and a body passageway when the cannula is positioned in the passageway, comprising:at least one thin flexible resilient annular disc extending generally perpendicularly from the cannula with a rim having a diameter larger than the opening of the body passageway; said disc having a series of partial slits extending from points on the disc generally radially outwardly to the rim, dividing a portion of said disc into annular sectors, so that when the cannula is positioned in the body passageway, the rim of each sector can independently bend, overlap and readily conform to the wall of the passageway, while the body of said disc remains substantially planer. 2. The sealing cuff as in claim 1, wherein said slits extend from points about midway between the cannula and the rim of said disc. 3. The sealing cuff as in claim 2 comprising a plurality of at last three said slit discs which are spaced adjacently apart along the cannula. 4. The sealing cuff as in claim 3, further comprising at lest one thin flexible resilient annular solid disc extending perpendicularly from the cannula and having a diameter smaller than that of the body passageway, and arranged adjacently to at least one of said slit discs. 5. The sealing cuff as in claim 3, further comprising a plurality of thin flexible resilient annular solid discs extending perpendicularly from the cannula and having a diameter smaller than that of the body passageway, and arranged alternately between said slit discs. 6. The sealing cuff as in claim 3 wherein said discs are arranged so that the slits of adjacent discs are not in alignment. 7. A non-inflatable sealing cuff on a tracheal tube having an elongated tubular cannular with a distal end, for forming an adequate fluid seal between the distal end of the cannular and the wall of the trachea when the trachael tube is positioned in the trachea, comprising:at least one thin flexible resilient annular disc extending perpendicularly from the distal end of the cannula with a rim having a diameter larger than the opening of the trachea; said disc having a series of partial slits extending from points on the disc generally radially outwardly to the rim, dividing a portion of said disc into annular sectors, so that when the cannula is positioned in the trachea, the rim of each sector can independently bend, overlap and readily conform to the wall of the trachea, while the body of said disc remains substantially planer. 8. The sealing cuff as in claim 7, wherein said slits extend from points about midway between the cannula and the rim of said disc. 9. The sealing cuff as in claim 8 comprising a plurality of at least three said slit discs which are spaced adjacently apart along the cannula. 10. The sealing cuff as in claim 9 wherein said discs are arranged so that the slits of adjacent discs are not in alignment. 11. The sealing cuff as in claim 9, further comprising at least one thin flexible resilient annular solid disc extending perpendicularly from the cannula and having a diameter smaller than that of the trachea, and arranged adjacent to at least one of said slit discs. 12. The sealing cuff as in claim 11, comprising about six said slit discs having a diameter of about 1.25 inch, with each disc having slits of about 0.1 inch about every 36 degrees dividing each slit disc into about ten annular sectors, and further comprising about five said solid discs having a diameter of about 1.0 inch, with said solid discs arranged alternately between said slit discs, and said discs spaced about 0.1 inch apart on the distal end of the cannula. 13. The sealing cuff as in claim 11 wherein said discs are D-shaped to facilitate forming a seal with the trachea of a patient. 14. The sealing cuff as in claim 9 wherein said discs are D-shaped to facilitate forming a seal with the trachea of a patient. 15. The sealing cuff as in claim 9, comprising about ten said slit discs having a diameter of about 1.0 inch, with each disc having slits of about 0.1 inch about every 36 degrees dividing each disc into about ten annular sectors, with said slit discs spaced about 0.1 inch apart on the distal end of the cannula.

1993-04-08

en

1994-06-21

US-35160799-A

Hurdle or rack board for sheet-fed printing machines ABSTRACT A hurdle board assembly for separating sheet piles in a delivery of a sheet-fed printing machine includes a hurdle board. A plurality of spacer elements are connected to the hurdle board at locations in the vicinity of the border of one surface of the hurdle board. The spacer elements are respectively movable between a condition wherein they are retracted into the hurdle board and a condition wherein they extend vertically from the hurdle board. Respective prestressing devices are provided for prestressing the spacer elements, respectively, in a direction in the condition wherein the spacer elements, respectively, extend from the hurdle board. Respective locking devices are provided for securing the spacer elements, respectively, in the retracted condition. The locking devices are deactivatable from a side of the hurdle board so as to release the spacer elements. BACKGROUND OF THE INVENTION Field of the Invention The invention relates to a hurdle or rack board for separating sheet piles in a delivery of a sheet-fed printing machine. Hurdle boards are panels or pallets which, in the delivery of a sheet-fed printing machine, are positioned on a pile board and then above one another, with an interposition of spacer elements, respectively, in order to form a relatively low partial pile of sheets of paper or other printing materials, respectively, thereon. Such a hurdle operation is necessary if sheets in a relatively high pile were to stick together as a result of the weight of the pile, as can occur, for example, in the case of intensive ink application and/or thin printing materials. The spacer elements keep the hurdle boards spaced apart from one another a distance that is greater than the height of the individual partial piles, with the result that the pile pressure is limited, and blocking of sheets is prevented. In the case of hurdle work or operation, the machine operator usually positions, for example, four spacer elements manually around the last-formed partial pile, on the pile board or on the uppermost of the hurdle boards which, for this purpose are somewhat larger than the maximum printable sheet format, and then places the next hurdle board in position, in which case, the operator must be careful not to move the spacer elements. These handling procedures are also necessary in the case of a delivery for non-stop operation, as is described, for example, in the published German Patent Document DE-A-4 344 361. In such a case, the introduction and positioning of the spacer elements is not merely laborious, but also, due to the continuing operation of the printing machine, very dangerous, in particular in the case of the rear or inner spacer elements, for which the operator has to reach far into the delivery. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide a hurdle board for sheet-fed printing machines which reduces the amount of energy expended for hurdle work or operation and the safety problems associated therewith. With the foregoing and other objects in view, there is provided, in accordance with the invention, a hurdle board assembly for separating sheet piles in a delivery of a sheet-fed printing machine, comprising a hurdle board, a plurality of spacer elements connected to the hurdle board at locations in the vicinity of the border of one surface of the hurdle board, the spacer elements, respectively, being movable between a condition wherein they are retracted into the hurdle board and a condition wherein they extend vertically from the hurdle board, respective prestressing devices for prestressing the spacer elements, respectively, in a direction of the condition wherein the spacer elements, respectively, extend from the hurdle board, and respective locking devices for securing the spacer elements, respectively, in the retracted condition, the locking devices being deactivatable from a side of the hurdle board so as to release the spacer elements. In accordance with another feature of the invention, the hurdle board is a rectangular panel having a surface area greater than a maximum sheet format, and the spacer elements, respectively, are disposed in the vicinity of respective corners of the hurdle board and outside the maximum sheet format. In accordance with a further feature of the invention, a multiplicity of parallel, regularly spaced-apart grooves are formed in at least one of the two surfaces of the hurdle board. In accordance with an added feature of the invention, the hurdle board assembly includes pushbuttons actuatable for deactivating the locking devices in order to release the spacer elements, the pushbuttons being located on side surfaces of the hurdle board. In accordance with an additional feature of the invention, the side surfaces of the hurdle board are formed at predetermined locations with recesses having a register form. In accordance with yet another feature of the invention, a surface of the hurdle board facing away from the spacer elements is formed so as to effect a formlocking or positive connection with extended spacer elements of an adjacent hurdle board. In this regard, it is noted that a formlocking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a forcelocking connection, which locks the elements together by force external to the elements. In accordance with yet a further feature of the invention, each of the spacer elements is formed as an elongated rail rotatably mounted at one end thereof in an elongated groove formed in the hurdle board, the spacer elements, respectively, being swingable into the respective elongated grooves. In accordance with a concomitant feature of the invention, the hurdle board has an overall height of approximately 1.5 to 2 cm when the spacer elements are in the retracted condition thereof. Such a hurdle board with integrated spacer elements is stored and handled in the condition in which the spacer elements are retracted. When required, the machine operator lifts the hurdle board into the delivery and aligns it therein. Thereafter, the machine operator deactivates or unlocks the locking or arresting device for the spacer elements, for example, by actuating pushbuttons which are provided in suitable positions laterally on the hurdle board. The spacer elements then swing out or extend automatically and are automatically located in the correct positions. Because the position of the spacer elements relative to the hurdle board is fixed, all that the machine operator need do is to ensure the correct alignment of the hurdle board relative to the preceding hurdle boards. The hurdle boards according to the invention can be used either with the spacer elements in the upward direction or with the spacer elements in the downward direction. In the former case, the spacer elements of a hurdle board on which a partial sheet pile is being formed are swung upwardly the instant the partial sheet pile has reached the permissible height, and the next hurdle board is placed in position. In the latter case, the spacer elements swing downwardly, and the hurdle board is deposited on the preceding hurdle board, on which a partial sheet pile has been formed. With a delivery provided for non-stop operation, it is usually the case that, while the next rack board is being introduced, a movable rake formed of parallel bars retains the sheets arriving continuously from the printing units. In order for the intermediate sheet pile formed on the rake to be transferred to the hurdle board, the latter is formed with parallel grooves which have a greater cross section than the bars and into which the bars can penetrate, whereupon the rake can be pulled out from underneath the intermediate sheet pile. Such grooves for non-stop operation may also be provided in a hurdle board according to the invention. If relatively low hurdle boards with a thickness of approximately 1.5 to 2 cm are used, the grooves are formed either on the surface with the spacer elements or on the opposite surface of the hurdle board, depending upon the orientation in which the rack boards are to be used. In the case of relatively high hurdle boards, it is also possible for grooves to be formed on both surfaces, with the result that these hurdle boards can be used on both sides. It is not just that the hurdle boards according to the invention are very simple and safe to use, but that they also make it possible wholly or partially to automate hurdle operation, which it has heretofore only been able to be executed manually. If pushbuttons or similar actuating elements which release the locking devices upon actuation are provided on side surfaces of the hurdle board, this not only facilitates manual operation, but also means that the pushbuttons can easily be actuated with the aid of, for example, electromechanical or pneumatic actuators which are provided at appropriate locations in the delivery, in order to release the spacer elements on a machine-control command. Within the context of yet further-advancing automation, it is possible for the hurdle boards to be fed mechanically to the delivery. In order to facilitate automatic handling of the hurdle board, it is possible to provide accurately fitting recesses at predetermined locations in the side surfaces of the hurdle board, it being possible for suitable gripping elements of an automatic conveying arrangement to engage in a positively locking or formlocking manner in the recesses. In the preferred embodiment, the hurdle board is a rectangular panel having a surface area that is greater than the maximum sheet format, one spacer element, respectively, being located in the vicinity of each corner of the hurdle or rack board and outside the maximum sheet format. If that surface of the hurdle board that is directed away from the spacer elements is formed for a positively locking or formlocking connection to the extended spacer elements of an adjacent hurdle board, the accurately fitting or in-register alignment of the hurdle board over the preceding hurdle board is facilitated. The spacer elements are preferably elongated rails which, at one end, respectively, are mounted rotatably in an elongated groove formed in the hurdle board, it being possible for the spacer element to be swung into the groove. Movable struts and, if appropriate, additional locking or arresting devices may be provided in order to fix the spacer elements in the swung-out or extended condition. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a hurdle or rack board for sheet-fed printing machines, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a to 1f are diagrammatic elevational views of diverse forms of hurdle boards with integrated foldable spacer elements; FIGS. 2a and 2b are side elevational views of a foldable spacer element in a hurdle board, shown in extended and retracted conditions, respectively; and FIG. 2c is a top plan view of FIG. 2b. DESCRIPTION OF THE PREFERRED EMBODIMENTS The hurdle board assemblies shown in FIGS. 1a to 1f have hurdle boards 2 formed as rectangular panels or pallets having a width and a length which are greater than the width and the length, respectively, of the largest sheets which can be printed in a printing machine having a delivery in which the hurdle boards are used. The hurdle board 2 is provided with four spacer elements 4, one at each corner, which can be swung inwardly or retracted, and swung outwardly or extended, the spacer elements 4 in FIG. 1a having been swung out vertically upwardly. The spacer elements 4 are located on the top side of the hurdle board 2, outside the surface area corresponding to a maximum printable sheet format. A sheet pile can be formed on the top side of the hurdle board 2 up to a maximum height, which is smaller than the length of the spacer elements 4. Thereafter, a further hurdle board 2, of which the spacer elements 4 are swung out upwardly, is placed in position thereon, and so forth. It is alternatively possible for the hurdle board 2 to be used in reversed position, with the spacer elements 4 directed downwardly, as shown in FIG. 1b. FIG. 1b also shows a further hurdle board 2 that has been positioned on top, as well as a sheet pile 6 between the hurdle boards 2. FIG. 1c shows a hurdle board 8 that is suitable for a So-called non-stop delivery. Formed in the top side of the hurdle board 8 are a multiplicity of equally spaced-apart parallel grooves 10, in which a non-illustrated rake can engage in order to permit the pile board of the delivery to be lowered and to introduce a new hurdle board 8, while the continuously fed sheets are stored in the interim by the rake. The spacer elements 4 of the hurdle board 8 extend upwardly, i.e., they are located on the same side of the hurdle 8 as the grooves 10. The hurdle board 12 shown in FIG. 1d differs from the hurdle board 8 in FIG. 1c merely by the fact that the spacer elements 4 of the hurdle board 12 extend downwardly, i.e., they are located on that side of the hurdle board 8 that is opposite from the grooves 10. Such hurdle boards 12 are stacked as is shown in FIG. 1b. While the hurdle boards 2, 8 and 12 shown in FIGS. 1a to 1d are thin enough and low enough, respectively, for the bending or sagging that occurs during loading still to be acceptable in the normal case, use is sometimes also made of higher hurdle boards, such as are shown in FIGS. 1e and 1f. The hurdle board 14 in FIG. 1e is similar to the hurdle board 2 of FIG. 1a, but it is considerably thicker and higher, respectively. In order to limit the weight, the hurdle board 14, rather than being solid, is formed with diagrammatically represented cavities 16. Except for its thickness, the hurdle board 18 of FIG. 1f corresponds to the hurdle board 12 of FIG. 1d. FIGS. 2a and 2b are cross-sectional views of a hurdle board 2, as in FIG. 1a, in the region of a spacer element 4 which, in FIG. 2a, is in the swung-out or extended condition, while FIG. 2b shows the spacer element 4 in the swung-in or retracted condition. FIG. 2c is a plan view of the hurdle board 2 in the condition of FIG. 2b. In the vicinity of each corner, the hurdle board 2 is formed with an elongated recess or groove 20 in the top side thereof, as viewed in FIG. 2a. The groove 20 extends along a side wall 22 (note FIG. 2c) of the hurdle board 2. The groove 20 is somewhat longer and has a somewhat greater cross section than the spacer element 4 which, in this embodiment, is an elongated rail of U-shaped cross section. Thus, the entire spacer element 4 can be received in the groove 20. At one end, the spacer element 4 is swivellably mounted on a pin 24 that runs transversely through the groove 20 at one end of the latter. An elongated leaf spring 26, which is supported on the base of the groove 20, extends behind the pin 24 and into the spacer element 4, with the result that the spring 26 prestresses the spacer element 4 into the swung-out or extended condition thereof shown in FIG. 2a. In this swung-out or extended condition, the spacer element 4 is retained in its vertical position by a strut 28. At one end, the strut 28 is connected swivellably to the spacer element 4. At its other end, the strut 28 is mounted swivellably and is displaceable in the longitudinal direction in slots or elongated notches 30 formed in the side walls of the groove 20. If the spacer element 4 is swung into the condition thereof shown in FIGS. 2b or 2c, counter to the action of the leaf spring 26, the strut 28 is displaced until it is received in its entirety in the interior of the spacer element 4. In this swung-in or retracted condition, the outer end of the spacer element 4 is secured by an arresting element having an axially movable shank 32 that passes through the side wall 22 and, in the interior, carries a catch 34 that engages behind the spacer element 4. Fastened at the outer end of the shank 32 is a pushbutton 36 (FIG. 2c), part of which is received in an opening formed in the side wall 22. A helical spring 38 prestresses the pushbutton 36 outwardly. When manual or mechanical pressure is exerted upon the pushbutton 36, the catch 34 releases the spacer element 4, so that the latter snaps upwardly into the condition shown in FIG. 2a. In order to facilitate the locking of the spacer element 4 as it swings inwardly or retracts, it is possible for the catch 34 and the corresponding mating surface at the outer end of the spacer element 4 to carry non-illustrated sloping ramp surfaces which can slide on one another as the shank 32 is displaced axially. If the stressing of the leaf spring 26 is insufficient for retaining the swung-out or extended spacer element 4 reliably in the vertical condition thereof, additional arresting devices may be provided for this purpose. For example, the slot or notch 30 may be formed so that the spacer element 4 is retained in a self-locking manner in the swung-out or extended condition, or the arresting element which, in the exemplary embodiment, has the shank 32, the catch 34 and the pushbutton 36, is constructed and disposed in some other manner, so that it also arrests the swung-out or extended spacer element 4. In the region of the bearing location of the spacer element 4 in the hurdle board 2, a recess 40 is formed on the underside of the hurdle board 2, the outer end of a swung-out or extended spacer element 4 of a further hurdle board 2 fitting into the recess. This prevents lateral slippage of the hurdle boards 2 which are stacked above one another. In the vicinity of each corner of the rack board 2, a recess 42 having a tetrahedral shape, for example, is formed in the side wall 22. The recesses 42 make it possible for the hurdle board 2 to be gripped in a positive or formlocking and accurately fitting or in-register manner by any type of gripping elements of an automatic conveying arrangement. In this regard, it is noted that a formlocking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a forcelocking connection, which locks the elements together by force external to the elements. Instead of integral or one-piece spacer elements 4, it is also possible to use multipartite, length-adjustable spacer elements with which the pile height of the hurdle boards 2 can be adapted to the respective conditions. When the hurdle board is of suitable thickness, rather than using swingable or foldable spacer elements, it is also possible to use spacer elements which can be extended telescopically out of the hurdle board. We claim: 1. A hurdle board assembly for separating sheet piles in a delivery of a sheet-fed printing machine, comprising a hurdle board, a plurality of spacer elements connected to said hurdle board at locations in the vicinity of the border of one surface of the hurdle board, said spacer elements, respectively, being movable between a condition wherein they are retracted into the hurdle board and a condition wherein they extend vertically from the hurdle board, respective prestressing devices for prestressing said spacer elements, respectively, in a direction in the condition wherein said spacer elements, respectively, extend from said hurdle board, and respective locking devices for securing said spacer elements, respectively, in said retracted condition, said locking devices being deactivatable from a side of said hurdle board so as to release said spacer elements. 2. The hurdle board assembly according to claim 1, wherein said hurdle board is a rectangular panel having a surface area greater than a maximum sheet format, and said spacer elements, respectively, are disposed in the vicinity of respective corners of said hurdle board and outside the maximum sheet format. 3. The hurdle board assembly according to claim 1, wherein a multiplicity of parallel, regularly spaced-apart grooves are formed in at least one of the two surfaces of said hurdle board. 4. The hurdle board assembly according to claim 1, including pushbuttons actuatable for deactivating said locking devices in order to release said spacer elements, said pushbuttons being located on side surfaces of said hurdle board. 5. The hurdle board assembly according to claim 4, wherein said side surfaces of said hurdle board are formed at predetermined locations with recesses having a register form. 6. The hurdle board assembly according to claim 1, wherein a surface of said hurdle board facing away from said spacer elements is formed so as to effect a formlocking or positive connection with extended spacer elements of an adjacent hurdle board. 7. The hurdle board assembly according to claim 1, wherein each of said spacer elements is formed as an elongated rail rotatably mounted at one end thereof in an elongated groove formed in said hurdle board, said spacer elements, respectively, being swingable into the respective elongated grooves. 8. The hurdle board assembly according to claim 1, wherein said hurdle board has an overall height of approximately 1.5 to 2 cm when said spacer elements are in said retracted condition.

1999-07-12

en

2000-11-21

US-51040295-A

Removable inner turbine shell with bucket tip clearance control ABSTRACT A turbine includes a plurality of inner shell sections mounting first and second stage nozzle and shroud portions. The inner shell sections are pinned to an outer containment shell formed of sections to preclude circumferential movement of the inner shell relative to the outer shell and enable thermal expansion and contraction of the inner shell relative to the outer shell. Positive bucket tip clearance control is afforded by passing a thermal medium about the inner shell in heat transfer relation with the shrouds about the first and second stage bucket tips, the thermal medium being provided from a source of heating/cooling fluid independent of the turbine. Access is provided to the rotor and turbine buckets by removing the outer and inner shell sections. This is a divisional of application Ser. No. 08/414,698 filed Mar. 31, 1995, now U.S. Pat. No. 5,685,693. TECHNICAL FIELD The present invention relates generally to turbines, and particularly to land-based gas turbines employing either closed-cycle steam or air cooling or open-cycle air cooling of hot gas path components and having removable inner and outer turbine shells affording access to the high maintenance hot gas path parts of the turbine without removal of the rotor for maintenance, repair and/or conversion between air and steam cooling. The present invention also relates to inner and outer turbine shells constructed to afford positive bucket tip clearance control. BACKGROUND Hot gas path components in gas turbines typically employ air convection and air film techniques for cooling surfaces exposed to high temperatures. High pressure air is conventionally bled from the compressor and the energy of compressing the air is lost after the air is used for cooling. In current heavy duty gas turbines for electric power generation applications, the stationary hot gas path turbine components, i.e., the nozzles and turbine bucket shrouds, are attached directly to massive turbine shell structures and the shrouds are susceptible to bucket tip clearance rubs as the turbine shell thermally distorts. That is, the thermal growth of the turbine shell during steady-state and transient operations is not actively controlled and bucket tip clearance is therefore subject to the thermal characteristics of the turbine. Bucket tip clearance in these heavy duty industrial gas turbines is typically determined by the maximum closure between the shrouds and the bucket tips (which usually occurs during a transient) and all tolerances and unknowns associated with steady-state operation of the rotor and stator. Steam cooling of hot gas path components has been proposed, utilizing available steam from, for example, the heat recovery steam generator and/or steam turbine components of a combined cycle power plant. Where steam is utilized as the coolant for gas turbine components, there is typically a net efficiency gain inasmuch as the gains realized by not extracting compressor bleed air for cooling purposes (typically in an open-cycle configuration) more than offset the losses associated with the use of steam as a coolant instead of providing energy to drive the steam turbine. The steam cooling concept is even more advantageous when the steam coolant is provided in a closed loop whereby the heat energy imparted to the steam as it cools the gas turbine components is recovered as useful work in driving the steam turbine. Because of the differences in heat transfer characteristics between air and steam, it would be expected that turbine components designed to utilize these two cooling mediums would be constructed differently. For example, a turbine nozzle designed to be cooled by closed-loop steam cooling would be expected to be substantially different from a nozzle cooled by open-cycle air cooling. The internal passages which provide convection cooling would be shaped differently and, whereas in the case of steam cooling the coolant would be recovered from the nozzle to provide useful work elsewhere, in the case of air cooling, the air would typically be discharged through holes in the walls of the nozzle partitions to form a coolant film over the cooled component. For a gas turbine to have the flexibility to be cooled with either air or steam (a feature of the present invention described below), it is necessary to provide the ability to interchange certain components (those to be cooled) to accommodate the different cooling mediums. A customer purchasing a simple cycle gas turbine power plant, for example, would almost certainly need to have the turbine components cooled by air, there being no available source of alternative coolant. If, however, the customer later expands his plant to an uprated combined cycle plant, steam becomes readily available as a coolant and it would to be advantageous, from an efficiency point of view, to utilize this steam to cool the turbine, necessitating a change in at least some of the hot gas path components. Removal of the stationary hot gas path components for maintenance and replacement in respective air and steam-cooled turbines typically involves major downtime and costs. Additionally, in the case of steam cooling, direct connection of steam cooling pipes between the actively cooled hot gas path components and a single turbine shell make component removal impossible without rotor removal or an overly large shell diameter. Further, cost-effective maintenance and repair of gas turbines requires change-out of all hot gas path components without rotor removal. Thermodynamic performance of a gas turbine is a primary characteristic in determining the economic value of the turbine. Turbine bucket tip clearance is a primary contributor to improved thermodynamic; performance. In current practice, the stator components are mounted on a single turbine shell. Turbine shell distortion caused by thermal and mechanical loads manifests itself as circumferential variation in radial location of the bucket shrouds and nozzle diaphragms. This circumferential asymmetry is currently accounted for by increased bucket tip to shroud operating clearances as noted previously. This has a very substantial negative impact on thermodynamic performance. Consequently, there is a need to minimize the variation in radial clearance between the shroud and bucket tips to improve turbine performance. Tip clearance control becomes even more critical with steam cooling due to the possibility of steam leakage into the hot gas path due to rubs. It will be appreciated that a bucket utilizing a closed circuit cooling system returns all of the thermal cooling medium to be used elsewhere in the system without dispersing it into the hot gas path as in an air-cooled system. This increases the difficulty of cooling the bucket tip. Therefore, the bucket tip cap must be significantly thinner than in an open circuit cooling design to enhance conductive cooling of the tip. The reduced tip thickness increases the likelihood that a rub against, or contact with, the shroud would penetrate the cooling passages, causing evacuation of the cooling medium and potential bucket failure. Consequently, tip clearance control, particularly in a closed circuit cooling design where the components are readily removable, is of critical importance. DISCLOSURE OF THE INVENTION According to the present invention, a turbine is provided with inner and outer shells. For discussion purposes, the turbine preferably comprises four stages with the inner shell mounting the first and second stage nozzles, as well as the first and second stage shrouds, while the outer shell mounts the third and fourth stage nozzles and shrouds. It will be appreciated, however, that a greater or lesser number of turbine stages, as well as a different number of nozzle stages and shrouds supported by the inner and outer shells, may be provided. Each of the inner and outer shells is formed in circumferentially extending sections about the rotor axis, preferably in two circumferential halves (upper and lower) of 180° each. The upper outer shell half and each inner shell half are individually removable from the turbine without removal of the rotor to enable access to the hot gas path components for maintenance, repair and/or changeover between air and steam cooling components. Where an air-cooled turbine is provided , it will be appreciated that cooling air is provided to the stationary components, e.g., the first and second stage nozzles, and those components are carried by the inner shell in communication with high pressure air from the compressor. The first stage nozzle may lie in open communication with the high pressure discharge in the cavity supplying high pressure air to the combustors. Separate piping may be provided for supplying a lower pressure cooling air from the compressor extraction grooves through the outer shell into a cavity between the inner and outer shells and into the second stage nozzles. The cooling air provided is, of course, in an open circuit, the air exiting the partitions or vanes of the first and second stage nozzles for film cooling into the hot gas stream. Cooling air may similarly be piped directly through the outer shell to the third stage nozzle while the fourth stage nozzle remains uncooled. Additionally, air is introduced into the turbine rotor and into the turbine buckets of the first and second stages in an open-loop circuit whereby spent cooling air is discharged into the hot gas stream. In a closed-circuit steam cooling system for the turbine, cooling steam is provided to each of the nozzle partitions of the first and second stages by way of discrete steam supply and spent cooling steam exit pipes, coupled to the partitions through the inner shell and releasably coupled at their outer ends to the outer shell. The couplings between the steam pipes and the outer shell are accessible externally of the turbine whereby access to the hot gas path components for maintenance and repair can be obtained, as explained below. Additionally, closed-circuit steam cooling supply and spent cooling steam return conduits are provided through the rotor and into the buckets of the first and second stages. In the air and steam cooling arrangements for the preferred four stage turbine embodiment, the third stage is air-cooled, while the fourth stage remains uncooled. The present invention is concerned with the inner and outer shells, their mounting to one another, accessibility to the turbine rotor components and tip clearance control in the context of the inner and outer shells. For a complete description of the air and steam cooling circuits for the rotational components, i.e., the rotor and buckets, of which the present invention forms a part, reference is made to co-pending patent application Ser. No. 08/414,695, titled "Closed or Open Circuit Cooling of Turbine Rotor Components", and for a disclosure of the first and second stage steam-cooled buckets, reference is made to patent application Ser. No. 08/414,700, titled "Closed Circuit Steam-Cooled Bucket" (Attorney, the disclosures of which are incorporated herein by reference. Also, for a disclosure of the first and second stage steam-cooled vanes, reference is made to patent application Ser. No. 08/414,697, titled "Turbine Stator Vane Segments Having Combined Air and Steam Cooling Circuits", the disclosure of which is incorporated herein by reference. Consequently, it will be appreciated that to effect a changeover in a single turbine from air to steam cooling, certain component parts must be designed, removed and/or replaced to accommodate the different cooling mediums. Hence, convenient access to the hot gas path components without rotor removal is essential. The hot gas path components which must be interchanged comprise the first and second stage nozzles and buckets and associated piping for the air and steam cooling circuits as appropriate. All other components of the turbine, however, remain common. That is, the inner and outer shell, the third and fourth stages, as well as all rotor wheels and spacer disks and axial rotor bolts remain the same. To accomplish this changeover between air and steam cooling components and/or to obtain access to the hot gas path components for maintenance and/or repair, the outer shell is provided in upper and lower sections (e.g., two halves), each mounting portions of the third and fourth stage nozzles and shrouds of the four stage turbine. The various inlet and exit heating/cooling fittings extending through the outer shell sections and connected to piping carried by the inner shell to afford tip clearance control (discussed below) and to cool the hot gas path airfoils for either air or steam cooling, may be accessed externally of the cuter shell for disconnection (as well as for connection). Rollers are disposed through access openings in the lower outer shell half to support the inner shell. Pins carried by the inner shell coupling the inner and outer shells together and supporting the inner shell from the outer shell are then uncoupled from the outer shell through access openings in the outer shell. Upon uncoupling the pins, disconnecting the pipe fittings from the outer shell and installing the rollers, the upper section of the outer shell is disconnected from the lower section thereof at the horizontal joint. The upper outer shell section is then lifted and removed, together with the associated third and fourth stage nozzle assembly halves carried thereby. This provides access to the upper inner shell section carrying the first and second stage nozzles. Upon disconnecting the upper and lower sections of the inner shell from one another (e.g., at the horizontal joint between the section halves), the upper inner shell section with its assembled shrouds, nozzle stages and associated interior piping for tip clearance control and steam or air cooling, may be removed through the access opening formed by the removal of the upper outer shell section. In the case of the steam-cooled turbine, the supply and exit steam pipes are mounted on the inner shell and releasably coupled to the outer shell via adapter fittings accessible externally of the outer shell. Thus, by removal of the adapter fittings, the internal steam cooling piping carried by the inner shell is spaced radially inwardly of the outer shell. A simulated or dummy inner shell section of comparable weight to the removed inner shell section is then disposed in the access opening and both the dummy section and the lower inner shell section are rotated about the rotor axis and on the rollers to locate the previously located lower inner shell section in an upper position in registration with, and enabling its removal through, the turbine access opening. Thus, the entire first and second stage nozzle assembly is readily removed, affording access for the replacement or repair of stationary components (i.e., nozzles and shrouds), or conversion between air and steam cooling. In another aspect of the present invention, the inner and outer shells are connected to one another in a manner providing for an initial accurate minimum setting of the clearance between the bucket tips and the shrouds by enabling initial adjustment of the radial position of the inner shell relative to the rotor and the outer shell and, during turbine operation, enabling thermal growth, i.e., expansion and contraction, of the inner shell relative to the outer shell. To accomplish this, the inner shell is mounted to the turbine outer shell, preferably solely by a plurality of circumferentially spaced pins carried by the inner shell in radial planes at axial spaced locations preferably passing through the first and second stage shrouds. The pins project radially and are adjusted, e.g., by adjusting screws accessible externally of the outer shell to locate the inner shell accurately and precisely relative to the axis of the rotor, thereby affording initial close clearances between the bucket tips and the shrouds of the inner shell. Each pin restrains circumferential displacement and concentricity of the inner shell relative to the outer shell and the location of the pins about the shell prevent radial displacement of the inner shell relative to the outer shell. However, the pins enable unrestrained radial movement of the inner shell relative to the outer shell due to thermal growth, i.e., expansion and contraction, so that control over tip clearance can be maintained during turbine operation by the tip clearance control system, which will now be described. In a further aspect of the present invention, positive control of the thermal expansion and contraction of the inner shell relative to the outer shell is maintained to actively control tip clearance during turbine operation. To accomplish this, each semi-cylindrical, integrally cast or fabricated, inner shell half has an internal, generally circumferentially extending passageway or plenum in a radial plane at an axial location containing the first stage shrouds and a second internal, generally circumferentially extending plenum in a second radial plane at an axial location containing the second stage shrouds. The plenums are connected to one another by passageways within the inner shell. A thermal medium, from an auxiliary source independent of the turbine, is supplied to the plenums about the first and second stage shrouds through a fitting releasably secured to the inner shell and passing through the outer shell of the turbine. The source may comprise a cooling and/or heating fluid, preferably air, supplied by an auxiliary closed-cycle system comprised of, for example, a motor-driven compressor, a heat exchanger and a heater. The heating/cooling fluid is piped from the auxiliary system, circulated through the inner shell plenums about the first and second stage shrouds and returned. This heating/cooling fluid thus controls, as a function of turbine operation, the temperature and hence the thermal movement (i.e., radial expansion and contraction) of -the inner shell relative to the outer shell. Consequently, the radial locations of the first and second stage shrouds about the first and second stage bucket tips, respectively, are actively controlled during both steady state and transient operations. By way of example, during a hot restart of the turbine where the turbine has been previously running for a long period of time and the component parts are hot, severe rubbing of the turbine bucket tips may occur due to the difference in cool-down rates between the shrouds and the rotor. That is, the surrounding shrouds and support structure may cool faster than the rotor and shrink radially inwardly while the centrifugal action of the spinning rotor during a hot restart essentially elongates the buckets potentially into tip contact with the shrouds. By supplying a heating/cooling medium, e.g., air or steam, to the plenums in the inner shell, the radial dimension of the inner shell can be actively and substantially uniformly adjusted during both transient and steady state operations to control and thereby minimize tip clearance. Thus, by initially establishing a minimum tip clearance and actively controlling tip clearance during operation, improved turbine performance is achieved. In a preferred embodiment according to the present invention, there is provided a turbine comprising a rotor carrying buckets forming part of a turbine stage, an inner shell carrying nozzles and a shroud for surrounding tips of the buckets, an outer shell about the inner shell and connections between the inner and outer shells for supporting the inner shell against radial and circumferential movement and enabling thermal expansion and contraction of the inner shell relative to the outer shell in radial directions, the inner shell having a passage for containing a thermal medium to control the thermal expansion and contraction of the inner shell about the bucket tips thereby actively maintaining clearance between the shroud and the bucket tips during turbine operation. In a further preferred embodiment according to the present invention, there is provided a turbine, comprising an outer structural shell, an inner shell connected to the outer shell and carrying a nozzle and a shroud for a turbine stage, said shroud surrounding tips of buckets carried by a turbine rotor and a plurality of connecting elements engaging between the inner and outer shells aligning the inner shell about the rotor. In a still further preferred embodiment according to the present invention, there is provided a method of operating a turbine having a rotor including buckets carried thereby forming part of a turbine stage, an outer containment shell, an inner shell about the rotor including nozzles carried thereby forming another part of the turbine stage and a shroud about the tips of the buckets, and a passage in the inner shell for flow of a thermal medium to control thermal growth of the inner shell, comprising the steps of connecting the inner shell and the outer shell to one another to preclude radial and circumferential movement of the inner shell relative to the structural outer shell and enable thermal radial expansion and contraction of the inner shell relative to the structural outer shell, and flowing the thermal medium through the passage to control the temperature and thermal radial expansion and contracting of the shell thereby to control the clearance between the bucket tips and the shroud. In a still further preferred embodiment according to the present invention, there is provided in a turbine having a rotor, a method of positioning an inner shell carrying a shroud about the tips of turbine buckets carried by a turbine rotor, the inner shell being supported by an outer shell of the turbine, comprising the step of disposing radially directed, circumferentially spaced pins between and in engagement with the outer shell and the inner shell to restrain radial and circumferential relative movement of the inner and outer shells and enable substantially unrestrained thermal expansion and contraction of the inner and outer shells relative to one another. In a still further preferred embodiment according to the present invention, there is provided in a turbine having a rotor and an axis, a method of positioning an inner shell carrying a shroud about tips of turbine buckets carried by a turbine rotor, the inner shell being supported by an outer shell of the turbine, comprising the steps of disposing radially directed, circumferentially spaced pins in a radial plane between and in engagement with the outer shell and the inner shell and adjusting at least a pair of the pins for positioning the inner shell relative to the bucket tips carried by the rotor and the rotor axis. In a still further preferred embodiment according to the present invention, there is provided a method of removing at least one of inner shell sections carrying attached nozzle stage and shroud portions from a turbine having an outer housing including at least two outer shell sections overlying the inner shell sections, comprising the steps of disconnecting an outer shell section from the turbine housing and another of the outer shell sections, removing the disconnected outer shell section from the turbine housing to define an access opening into the turbine and removing an inner shell section with attached nozzle stage and shroud portions through the access opening. In a still further preferred embodiment according to the present invention, there is provided in a multi-stage turbine having hot gas path components cooled by one of air and steam cooling circuits, a method of converting between air and steam cooling circuits in the turbine, comprising the steps of removing the hot gas path components cooled by one of the air and steam cooling circuits from the turbine and replacing the removed hot gas path components with hot gas path components cooled by another of the air and steam cooling circuits. Accordingly, it is a primary object of the present invention to provide a gas turbine having a removable inner shell supporting hot gas path components affording access to the turbine stages without removing the turbine rotor, positive bucket tip clearance control and conversion between air and steam cooling circuits and related methods. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a gas turbine incorporating the present invention; FIG. 2 is a schematic diagram of a combined cycle system incorporating the present invention and employing a gas turbine and heat recovery steam generator for greater efficiency; FIG. 3 is a cross-sectional view of a portion of a turbine illustrating its combustor, compressor and turbine sections; FIG. 4 is an enlarged fragmentary cross-sectional view of a portion of the turbine illustrated in FIG. 3; FIG. 5 is a reduced cross-sectional view illustrating the inner and outer shells, and first and second stage buckets and nozzles, together with piping and passages for controlling thermal expansion and contraction of an inner turbine shell half; FIG. 5A is a schematic representation of the thermal circuit for the inner turbine shell half of FIG. 5; FIG. 6 is a fragmentary exploded perspective sectional view illustrating portions of the connections between the inner and outer shells; FIG. 7 is a schematic view taken along an axial plane illustrating the location of the pin connections between the inner and outer shells; FIG. 8A is a fragmentary cross-sectional view of a portion of the inner shell illustrating the connection between the inner and outer shells; FIG. 8B is an enlarged cross-sectional view looking radially inwardly through a top hat illustrating the connection between the inner and outer shells enabling fixation of the inner shell against radial and circumferential movement and relative thermal expansion and contraction; FIGS. 9 and 10 are schematic illustrations of a manner of accessing the lower inner shell section; FIG. 11 is a schematic view along a radial plane illustrating a manner of rotating the lower inner shell for subsequent removal; FIG. 12 is a fragmentary cross-sectional view illustrating rollers inserted through the outer shell for supporting the inner shell during disassembly and assembly of the turbine parts; FIG. 13 is an enlarged cross-sectional view of the rollers carrying the inner shell and taken generally about on line 13--13 in FIG. 12; and FIG. 14 is a view similar to FIG. 3 illustrating the commonality of turbine components for both air and steam cooling, as well as the components changed upon conversion between air and steam cooling. BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 is a schematic diagram for a simple cycle, single-shaft heavy-duty gas turbine 10 incorporating the present invention. The gas turbine may be considered as comprising a multi-stage axial flow compressor 12 having a rotor shaft 14. Air enters the inlet of the compressor at 16, is compressed by the axial flow compressor 12 and then is discharged to a combustor 18 where fuel such as natural gas is burned to provide high-energy combustion gases which drive the turbine 20. In the turbine 20, the energy of the hot gases is converted into work, some of which is used to drive the compressor 12 through shaft 14, with the remainder being available for useful work to drive a load such as a generator 22 by means of rotor shaft 24 for producing electricity. A typical simple cycle gas turbine will convert 30 to 35% of the fuel input into shaft output. All but 1 to 2% of the remainder is in the form of exhaust heat which exits turbine 20 at 26. Higher efficiencies can be obtained by utilizing the gas turbine 10 in a combined cycle configuration in which the energy in the turbine exhaust stream is converted into additional useful work. FIG. 2 represents a combined cycle in its simplest form, in which the exhaust gases exiting turbine 20 at 26 enter a heat recovery steam generator 28 in which water is converted to steam in the manner of a boiler. Steam thus produced drives a steam turbine 30 in which additional work is extracted to drive through shaft 32 an additional load such as a second generator 34 which, in turn, produces additional electric power. In some configurations, turbines 20 and 30 drive a common generator. Combined cycles producing only electrical power are in the 50 to 60% thermal efficiency range using the more advanced gas turbines. FIG. 3 illustrates in greater detail the gas turbine which is the focus of the present invention and which, preferably, is used in the combined cycle configuration of FIG. 2. Air from the compressor 12 is discharged to the combustion cans comprising combustor 18, the combustion cans being located circumferentially about the rotor shaft 14 in the usual fashion, one such "can" being shown at 36. Following combustion, the resultant combustion gases are used to drive the turbine section 20, which includes in the instant example four successive stages represented by four wheels 38, 40, 42 and 44 comprising the turbine rotor and mounted to the rotor shaft 14 for rotation therewith, and each carrying a row of buckets represented, respectively, by blades 46, 48, 50 and 52, which are arranged alternately between fixed nozzles represented by vanes 54, 56, 58 and 60, respectively. Thus, it will be appreciated that a four-stage turbine is illustrated wherein the first stage comprises nozzles 54 and buckets 46; the second stage, nozzles 56 and buckets 48; the third stage, nozzles 58 and buckets 50; and the fourth stage, nozzles 60 and buckets 52. Referring now to FIG. 4, the turbine is shown to include an outer structural containment shell 70 and an inner shell 72, the latter mounting the shrouds 74 and 76 for the first and second stages. As best illustrated in FIG. 3, the outer shell 70 is secured at axially opposite ends to the turbine exhaust frame 77, for example, by bolts 74, and at its upstream end to the compressor discharge casing 79 by bolts 75. It will be appreciated that the outer and inner shells 70 and 72 each comprise shell sections, preferably arcuate shell halves, extending substantially 180° for each shell half, about the rotor axis. Thus, the outer shell halves are bolted to the remaining turbine housing at axially opposite ends and to one another at a horizontal joint, not shown. It will be appreciated that the inner shell sections 72, as well as the outer shell sections 70, are each formed of integral castings or fabrications which are responsive to temperature changes and, hence, expand or contract depending upon the temperature changes. The axial extent of turbine inner shell 72 can be from one to all turbine stages, though in the preferred embodiment of FIGS. 3 and 4, it is shown as having an axial extent covering the first two of the illustrated four turbine stages and, in particular, two stages of stationary shrouds 74, 76 that are attached to it. The turbine inner shell 72 is not a pressure vessel nor a final containment vessel and, as such, does not require the structural integrity or flange sizes required by the outer turbine shell 70. This minimizes its thermal and mechanical distortion. Still referring to FIG. 4, the inner shell 72 carries respective cooling medium supply and return pipes 49s and 51r for cooling each of the first and second stage nozzle vanes 54 and 56, respectively. These individual supply and return pipes are permanently connected by suitable flanges and gaskets to arcuate supply and return conduits 53s and 55r, respectively, spaced radially outwardly of the inner shell 72 radially inwardly of the outer shell 70, and extending circumferentially about the inner shell 72. Each conduit 53s and 55r has a pipe fitting 57 terminating in a radial outer annular flange 59 spaced radially inwardly of an associated access opening through the outer shell. Each access opening includes an annular flange having a plurality of bolt holes, e.g., flange 61 in FIG. 4. An adapter fitting 63, i.e., an annular flange with concentric sets of annular bolt holes, enables the pipe fittings to be releasably secured to the outer shell with access to the bolts to effect connection and disconnection between the outer shell 70 and pipe fittings 57 afforded through the access openings of the outer shell. That is, the bolts connecting the adapter fittings 63 to the pipe fittings 57 as well as connecting the fittings 63 to the outer shell 70 are both accessible externally of the outer shell 70. Consequently, by disconnecting the cooling supply and return pipes 49s and 51r, respectively, from the outer shell, leaving a space between each flange 59 and the inner surface of the outer shell, the outer and inner shells can be removed, as described below, to enable access to the rotatable turbine components for maintenance and repair. Additionally, with this configuration, air cooling stationary components can be readily replaced by steam cooling components using common parts of the rotor for both cooling mediums, e.g., wheels, spacers, third and fourth stage buckets, and other parts, as well as the outer shell. Referring row to FIGS. 6, 7 and 8A, the inner shell 72 is secured to the outer shell 70 along radial planes normal to the axis of the rotor and at axial locations preferably in alignment with the first and second stage buckets and shrouds. To accomplish this, a plurality of pins 90 are connected to and between the inner and outer shells in a manner preventing movement of the inner shell relative to the outer shell in radial and circumferential directions, yet enabling unrestrained movement in a radial direction as a result of thermal distortion. Preferably, the pins between the inner and outer shells lie in the radial planes at circumferentially spaced positions thereabout. For example, eight pin locations may be used to interconnect the shells at each axial location, with each pin 90 lying approximately 45° about the rotor axis from adjacent pins. As illustrated in FIG. 7, the pins are also spaced from a horizontal joint J between the inner shell halves 72, the radially extending arrows in FIG. 7 representing the thermal expansion and contraction of the inner and outer shells relative to one another. The pins are preferably cylindrical, are secured to the inner shell and project radially outwardly therefrom to terminate in reduced sections 91 having flats 89 on opposite sides, i.e., the flats 89 face in a circumferential direction. The cylindrical radial inner ends of the pins are preferably shrunk-fit into complementary openings in and about the inner shell 72. As best illustrated in FIGS. 6, 8A and 8B, top hats 94 are provided through access openings 92 (FIG. 6) in the outer shell 70 at the circumferential locations of the pins 90. The top hats 94 have flanges with bolt holes for bolting the top hats to ring flanges about the access openings 92 in the outer shell having corresponding bolt holes. The top hats 94 each have a substantially cylindrical, radially inward extension 96 terminating at their inner ends in female threaded lateral openings 93. Adjusting screws 95, illustrated in FIGS. 8A and 8B, have male threaded ends for threaded engagement in diametrically opposed threaded openings 93 and project radially inwardly of the cylindrical top hat extension 96. The openings 93 and screws 95 lie in a circumferential plane also intersecting the flats 89 on the radially outer ends of the pins. The inner ends of the screws each have a convex spherical head 97 (FIG. 8B) engaging a complementary concave surface 98 on a spherical washer 99 having a flat surface 101 slidably engageable with the flat 89 on one side of a pin 90. Each screw 95 has a series of flats 103 between its male threaded end and its head 97. This enables a tool, such as a wrench, not shown, to be passed inwardly within the diametrically large cylindrical top hat extension 96 and engaged about the flats to rotate the adjusting screws 95 whereby access to the screws 95 is available externally of the outer shell 70. It will be appreciated that four adjusting screws 95 spaced 90° one from the other about the top hat extension may be used (with four flats 90° from one another about pin 90), although only two such screws in a circumferential plane are preferable. A blind flange bolted to the top hat at the outer turbine shell outer diameter seals radial gas leaks around the pins. The adjusting screws 95 can be selectively adjusted externally of the outer shell 70 to locate the inner shell 72 relative to the rotor axis with an initial minimum clearance between the shrouds 74 and 76 and the turbine buckets 46 and 48, respectively. As indicated previously, this arrangement secures the inner shell to the outer shell against circumferential and radial movement, but enables the inner shell to thermally distort, i.e., move radially relative to the outer shell in response to the application of the thermal medium in plenums 78 and 80 to facilitate the tip clearance control (as described below). When the inner shell is initially installed and adjusted by the adjusting screws 95 for alignment with the rotor axis, the pins 90 and screws 95 hold tight, running turbine tip clearances which can be maintained during steady-state and transient turbine operation by controlling the temperature of the inner shell through the supply of thermal medium from the heating/cooling source outside of and independent of the turbine to the plenums. Significantly, the pins are located in two planes normal to the axis of the rotor and pass through the first and second stage shrouds, respectively. Pins 90 constitute the structural support for the inner shell relative to the outer shell. Seals 100 and 102 are provided at the opposite ends of the shells, as illustrated in FIG. 4, to minimize air flow between regions of different air pressure denoted as I, II and III. Also, a plurality of pads 105 are disposed at circumferentially spaced positions between an aft bulkhead of inner shell 72 and a forward bulkhead of outer shell 70 as illustrated in FIG. 4. Pads 105 carry the axial loadings on the inner shell to the outer shell. In a preferred embodiment of the disclosed turbine, the running tip clearance between the tips of the turbine buckets 46 and 48 and the shrouds 74 and 76, respectively, is positively and actively controlled during steady-state turbine operation and transient conditions by controlling the temperature of the inner shell 72 and preferably controlling that temperature by employing a thermal medium in plenums 78 and 80 from, for example, a source independent of the turbine and its operation. To, in part, accomplish this objective, the inner shell 72 is supported by the plurality of pins 90 in radial planes passing through the first and second stage shrouds and buckets whereby the inner shell is supported from the outer shell against circumferential and radial movement solely by the pins and is enabled by the radially projecting pins to expand and contract in radial directions in response to thermal conditions, i.e., an applied thermal medium. Referring to FIGS. 5 and 5A, plenums or passages 78 and 80 are formed in the inner shell 72 at locations preferably radially outwardly of the shrouds 74 and 76, respectively. The plenums 78 and 80 extend arcuately in radial planes extending about each of the shell sections, e.g., the inner shell halves. As illustrated in FIG. 5A, the plenums 78 and 80 lie in serial communication one with the other by way of generally axially extending passageways 82 in each inner shell section adjacent its joint with an adjacent inner shell section. Thus, the passageways 82 interconnect the plenums 78 and 80 in a serial flow relationship. As illustrated in FIGS. 5 and 5A, an inlet pipe 84 extends through an access opening in the outer shell 70 for connection with an inlet fitting on the inner shell 72 whereby thermal medium may be passed through the outer shell 70 and into the plenum 78. Additionally, an outlet pipe 86 passes through an access opening in the outer shell 70 whereby thermal medium inlet to the inner shell plenums 78 and 80 may be discharged and returned to the thermal medium source. It will be appreciated that while the upper outer and inner shell halves are described and depicted, the lower outer and inner shell halves are substantially identical and that a description of one suffices as a description of the other. It will also be appreciated that, while only a single inlet pipe and a single outlet pipe are specifically disclosed for supplying thermal medium to the plenums of the shell sections, separate inlets and outlets may be provided the plenums 78 and 80. Also, the plenums 78 and 80 may be provided in plenum segments having separate inlets and outlets as desired without departing from the scope of the present invention. Further, the inlet and outlet pipes 84 and 86 (FIG. 5), respectively, are releasably coupled to pipe connections 84a and 86a on the inner shell in communication with plenums 78 and 80, respectively, in a manner enabling disconnection and connection of the inlet and outlet pipes with the respective plenums externally of the outer shell 70. This can be accomplished by gasketed flange connections at the juncture of the inlet 84 and an extension 84a fixed to inner shell 72 and at the juncture of the outlet pipe 86 and a flange ring 86a about the opening to plenum 80, the bolts for which lie within inlets 84 and outlets 86 and are accessible externally of shell 70 through respective inlets 84 and outlets 86. Referring again to FIG. 5, the thermal medium supplied to the plenums 78 and 80 is provided in this example by an external source independent of the turbine and preferably in a closed-loop circuit. The closed circuit may include a heat exchanger 88, a compressor 90 and a heater 92. In this manner, the thermal medium may provide cooling or heating thermal fluid to the plenums 78 and 80 via inlet 84 and outlet 86 in a closed circuit as necessary and desirable in accordance with the operating conditions of the turbine. The temperature of the heating/cooling medium supplied to the plenums 78 and 80 may be controlled in accordance with a predetermined schedule based on historical temperatures of the turbine during start-up, running speed and transients, such as shut-down, whereby the inner shell can be controlled to expand or contract to counter the typical thermal mismatches encountered in turbine operation. It will be appreciated that the pinned connections between the inner shell and the outer shell facilitate the tip clearance control. While the inner shell is fixed against radial and circumferential movement, the shell is responsive to controlled temperature inputs by way of the thermal medium to controllably expand or contract the inner shell to control the clearance of shrouds 74 and 76 relative to the tips of the buckets 46 and 48. For example, during start-up, the thermal medium supplied to the plenums 78 and 80 is a heating fluid. By heating the inner shell, it may be expanded at a rate equal to or greater than the rate of thermal expansion of the rotor and buckets. The radially projecting pins 90 thus slide in a radial outward direction along the flat faces of washers 99, enabling expansion of the inner shell and its shrouds relative to the outer shell to maintain clearance between the shrouds and the bucket tips. During a transient, the inner shell may tend to contract faster than the rotor, hence displacing the shrouds radially inwardly toward the bucket tips. In that event, heating fluid is supplied to the plenums such that the rate of thermal contraction of the inner shell is less than the rate of thermal contraction of the rotor and buckets to avoid contact between the turbine tips and shrouds. During steady-state operation, the temperature of the thermal medium is controlled to maintain a predetermined clearance between the shrouds and bucket tips. Thus, during all active thermal distortions of the shells, the connections between the adjusting screws carried by the outer shell and the pins carried by the inner shell permit relative sliding motion between the flats of the pins and the washers of the adjusting screws to enable tip clearance control. The inner shell is otherwise unsecured except for the seals at opposite axial ends thereof. Another aspect of the present invention resides in the capability to access the turbine and remove the hot gas components of the turbine stages without removal of the rotor from the turbine. Referring again to FIG. 3, it will be appreciated that the outer shell 70 of the turbine carries the third and fourth stage nozzles 58 and 60 in the present preferred four-stage turbine, whereas the inner shell 72 supports and carries the first and second stage nozzles 54 and 56, respectively. Also, as stated previously, the inner and outer shells are each provided, preferably, in upper and lower shell halves. Elongated access openings 102 are formed along the lower outer shell half as schematically illustrated in FIG. 12. Roller assemblies 104 are inserted into the elongated access openings and engage the inner shell 72 for supporting the inner shell from the rollers and enabling the inner shell to rotate on the rollers. A second set of rollers is used in the same set of holes that top hats 94 use. The top hats are removed, one at a time, and the roller assemblies installed. The rollers are offset from pins 90, thereby allowing the inner shell to be rolled out without removing the pins. Roller assemblies 104, 106 are inserted into access openings 125, 102, respectively, and into contact with lands 108, 109, respectively, which form part of the inner shell 72. As shown in FIG. 13, roller assembly 104 (as well as roller assembly 106) is in the form of a two-wheel bogie truck, with wheels 111 pivotably attached at 113 to threaded stud 115 which is provided with a threaded collar 117. Collar 117 has a larger diameter shoulder flange free to rotate on the inner turbine shell 70, the collar being held in place by a "C" ring. By rotating the threaded collar 117, the stud 115 advances and hence the wheels 111 may engage the lands. Reverse rotation of the collar 117 retracts the wheel assemblies 104. Wheel assemblies 106 are substantially similar to wheel assemblies 104, differing only in the size and number of wheels to accommodate their share of the load of the inner shell 72 during assembly and disassembly. Prior to removing the outer upper shell half, the adjusting screws 95 are backed off flats 89 and the top hats 94 are removed by withdrawing them through their access openings in the outer shell, leaving the inner shell supported solely by the rollers inserted into the lower outer shell half as previously described. Also, the cooling pipe fittings 57 and thermal medium inlet and outlet connections 84 and 86, respectively, and their associated adapter fittings 63, are disconnected through the access openings in the outer shell 70. It will be appreciated that when the adapter fittings are removed, the cooling pipe flanges 59 and the inlet extension to plenum 78 and the outlet from plenum 80 are spaced radially inwardly of the outer shell to afford clearances therebetween enabling removal of the lower inner shell half as described below. As noted previously, the upper outer shell half may be removed from the turbine by unbolting the axially opposite end flanges from the remainder of the turbine housing and unbolting the upper outer shell half from the lower outer shell half along a horizontal joint therebetween. By lifting the upper outer shell half from the turbine, the third and fourth stage nozzles 58 and 60, respectively, are likewise removed from the turbine with the upper outer shell half. The removal of the upper outer shell half also provides access for removal of the inner shell halves with the first and second stage nozzles and shrouds carried thereby and affords access to the turbine buckets and other hot gas path parts for their removal and replacement as necessary. This is schematically illustrated in FIG. 9, where the upper outer shell half 70 and the upper inner shell half 72 have been removed. With both the upper, outer and inner shell halves removed, a simulated or dummy inner shell half 110 (FIG. 10) is secured to the lower inner shell half. The dummy or simulated shell half is of a similar weight as the inner shell half. A rolling fixture 112 may be secured to the turbine housing, i.e., the lower outer shell half, surrounding the dummy inner turbine shell 110. A winch 114 may be provided on the rolling fixture and a line attached to the lower inner shell half. By operation of the winch, the lower inner shell half and the dummy inner shell half may be rotated about the rotor axis for exposure of the lower inner shell half in the access opening. Other suitable tools may be used to rotate the dummy inner shell half and the lower inner shell half as a unit to bring the previously lower inner shell half into an upper position in the access opening. Once located in the access opening, the lower inner shell half, together with the first and second stage nozzles and shroud portions carried thereby can be removed through the access opening whereby all of the nozzles and shrouds can be replaced. The reverse procedure may be used to reassemble the turbines with replaced or refurbished parts. For example, with the dummy shell half 110 in place, a new inner shell half may be disposed in the access opening adjoining the dummy shell. By rotating the new inner shell half and the dummy shell, the new inner shell half may be located in the lower half of the turbine housing. A second new inner shell half may then be disposed in the access opening and secured to the lower inner shell half. The upper outer shell half is then replaced, closing the turbine. The top hats 94 are then inserted and the adjusting screws adjusted to initially align the inner shell about the rotor axis with minimum tip clearance. The pipe fittings 57 and the inlet and outlet connections for the thermal medium are then reconnected through the access openings in the outer shell and the roller assemblies are removed. The turbine is now in running condition. Referring to FIG. 14, the turbine hereof is illustrated with parts stippled and parts left clear. The stippled parts of FIG. 14 represent those components of the turbine rotor which are common to the turbine when using either air or steam cooling. The clear parts of FIG. 14 represent those components of the turbine rotor which must be replaced when the rotor is converted between air and steam cooling, the steam cooling components being illustrated. For example, a customer may require initially an air-cooled four stage turbine and later require conversion from the air-cooled turbine to a steam-cooled turbine. Rather than replacing the entire turbine, only the first and second stage buckets 46 and 48, first stage shrouds 74, and first and second stage partitions 54 and 56 of the air-cooled turbine require replacement. By removing the top outer shell 70 and the inner shell halves, as previously described, the inner shell can be refurbished by removing the first stage shrouds and the first and second stage partitions and replacing those elements with the shrouds, partitions and piping necessary for steam cooling. Obviously, an entirely new turbine inner shell could be provided as the replacement part. Additionally, with access to the rotating components, the first and second stage air-cooled turbine buckets can be replaced by first and second stage steam-cooled buckets. The replacement turbine buckets and rotor steam cooling circuit disclosed in those prior applications referenced earlier would complete the conversion. Consequently, common parts used for either air cooled or steam-cooled turbines include the inner and outer shells, the third and fourth stage nozzles, the second stage shrouds, all rotor wheels and spacers and the third and fourth stage turbine buckets. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. What is claimed is: 1. A turbine comprising:a rotor carrying buckets forming part of a turbine stage; an inner shell carrying nozzles and a shroud for surrounding tips of said buckets; an outer shell about said inner shell; and connections between said inner and outer shells for supporting said inner shell against radial and circumferential movement and enabling thermal expansion and contraction of said inner shell relative to said outer shell in radial directions, said inner shell having a passage for containing a thermal medium to control the thermal expansion and contraction of said inner shell about said bucket tips and relative to said outer shell, thereby actively controlling clearance between said shroud and said bucket tips during turbine operation. 2. A turbine according to claim 1 wherein said inner shell comprises a pair of generally semi-cylindrical integrally cast sections, each section having a plenum extending generally arcuately about the shell for containing the thermal medium. 3. A turbine according to claim 1 wherein said passage lies radially outwardly of said shroud. 4. A turbine according to claim 1 wherein said connections comprise pins disposed at circumferentially spaced locations about said inner and outer shells and adjusting elements for said pins for adjusting the location of the inner shell radially and circumferentially relative to the outer shell, thereby adjusting the location of the inner shell relative to the rotor. 5. A turbine according to claim 4 wherein said pins are carried by said inner shell, said adjusting elements being carried by said outer shell. 6. A turbine according to claim 1 wherein said connections comprise pins disposed at circumferentially spaced locations about said inner and outer shells, said inner shell being structurally supported by said pins along a radial plane passing through said inner and outer shells and lying generally perpendicular to the axis of the rotor. 7. A turbine according to claim 1 including means external to said turbine and in communication with said passage for supplying a thermal medium to said passage. 8. A turbine according to claim 7 wherein said external means and said passage comprise a closed-loop circuit. 9. A turbine according to claim 1 wherein said rotor carries buckets forming part of another stage of said turbine, said outer shell carrying nozzles and a shroud for surrounding tips of the buckets of said another stage. 10. A turbine according to claim 1 wherein said rotor carries buckets forming parts of first, second, third and fourth stages, said inner shell carrying first and second stage nozzles and shrouds surrounding the tips of the first and second stage buckets, said outer shell carrying third and fourth stage nozzles and shroud surrounding the tips of the third and fourth stage buckets, piping carried by said inner shell for supplying a cooling medium to said first and second stage nozzles, and fittings accessible externally of said outer shell and coupled to said piping. 11. A turbine, comprising:an outer structural shell; an inner shell connected to said outer shell and carrying a nozzle and a shroud for a turbine stage, said shroud surrounding tips of buckets carried by a turbine rotor; and a plurality of connecting pins engaging between said inner and outer shells aligning said inner shell about the rotor, said pins being disposed at circumferentially spaced locations about said inner and outer shells, and adjusting elements for displacing said pins in circumferential and radial directions for adjusting the location of the inner shell circumferentially and radially relative to the outer shell, thereby adjusting the location of the inner shell relative to the rotor. 12. A turbine according to claim 11 wherein said pins are carried by said inner shell, said adjusting elements being carried by said outer shell.

1995-08-02

en

1998-07-14

US-58141895-A

Method and apparatus for processing multicarrier signals ABSTRACT Some embodiments of the present invention are capable of reducing the dynamic range of multicarrier signals. In an exemplary embodiment, the multicarrier signal processor includes a controller configured to receive at least a portion of a multicarrier signal, the controller analyzing the signal to identify at least one carrier signal of the multicarrier signal to be modified. At least one signal modifier communicates with the controller, the signal modifier receiving at least a portion of a multicarrier signal. The signal modifier isolates a carrier signal to be modified as directed by the controller, and modifies the isolated carrier signal. A negative delay is imparted to the carrier signal. A signal combiner receives the modified carrier signal and combines it with an unmodified multicarrier signal. Preferably, the multicarrier signal processor is used to reduce the dynamic range of a multicarrier signal. CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of U.S. application Ser. No. 08/315,382, filed Sep. 30, 1994, which is incorporated by reference. FIELD OF THE INVENTION The present invention relates to multicarrier signal processing and, more particularly, to methods and apparatus which alter the dynamic range of a multicarrier signal. BACKGROUND OF THE INVENTION In radio transmission and reception systems, a radio receiver is typically confronted with a multicarrier signal, i.e., a signal comprising a plurality of carrier signals having different signal characteristics, such as different frequencies. Due to variations in broadcast strength and the different locations from which they are broadcast, the respective carrier signals of a multicarrier signal arrive at a particular radio receiver with varying strengths. The difference in strength between the highest and lowest constituent carrier signals defines the dynamic range of the multicarrier signal. FIG. 1 depicts a schematic diagram of the front-end of a conventional radio receiver. Receiver 100 receives the broadband signal via antenna 101. Bandpass filter 105 takes the received broadband signal and passes only the multicarrier signal, eliminating signals whose frequencies are outside the multicarrier range defined by the filter. The multicarrier signal is mixed down by mixer 117 cooperating with local oscillator 125 and sent to a second bandpass filter 119. Bandpass filter 119 selects the particular frequency band or bands of interest which form the output signal. Typically, the utility of a radio receiver is limited by the dynamic range of the receiver components that process the signals of interest. More specifically, the dynamic range that the radio receiver can satisfactorily process is usually limited, at one extreme, by noise, and at the other extreme, by the inherent physical characteristics of mixer 117. If the dynamic range of mixer 117 is too low, the mixing of a multicarrier signal with a wide dynamic range can introduce undesirable intermodulation products into the output signal. When the radio receiver forms a portion of a wireless telecommunications system, the wide variation in signal power levels creates particular signal processing problems. Therefore, there is a need in the art for signal processing elements that can process multicarrier signals with wide dynamic ranges without introducing distortion n the resultant output signal. Such signal processors could advantageously be employed in radio receivers and wireless telecommunications systems to reduce the dynamic range of multicarrier signals. SUMMARY OF THE INVENTION The present invention provides a multicarrier signal processor capable of reducing the dynamic range of multicarrier signals. In an exemplary embodiment, the multicarrier signal processor includes a controller configured to receive at least a portion of a multicarrier signal. The controller analyzes the signal to identify at least one carrier signal of the multicarrier signal to be modified. At least one signal modifier communicates with the controller, the signal modifier receiving at least a portion of a multicarrier signal. The signal modifier isolates a carrier signal to be modified as directed by the controller, and modifies the isolated carrier signal. A signal combiner receives the modified carrier signal and combines it with an unmodified multicarrier signal. Preferably, the multicarrier signal processor is used to reduce the dynamic range of a multicarrier signal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a schematic diagram of a conventional radio receiver front-end; FIG. 2 depicts an illustrative radio receiver according to the present invention; FIG. 3 depicts a block diagram of an illustrative embodiment of the present invention; FIG. 4 is a block diagram of the individual signal modifier of FIG. 3; FIG. 5 is a block diagram of an illustrative controller as shown in FIG. 3; FIG. 6 is a block diagram of another illustrative controller as shown in FIG. 3; FIG. 7 depicts the spectral content of an exemplary multicarrier signal; FIG. 8 depicts the spectral content of the multicarrier signal of FIG. 7 after it has been altered according to the present invention; FIG. 9 is a schematic illustration of a cellular communications system which incorporates the multicarrier signal processor of the present invention; FIG. 10 depicts a radio receiver according to a second illustrative embodiment of the present invention; FIG. 11 depicts a block diagram of the second illustrative embodiment of the present invention; and FIG. 12 is a block diagram of the individual signal modifier of FIG. 11. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Turning now to the drawings in detail in which like numerals indicate the same or similar elements, FIG. 2 depicts a schematic diagram of a multicarrier signal processor 201 according to the present invention. Illustratively, signal processor 201 is described as part of radio receiver front-end 100. However, it will be appreciated by those skilled in the art that signal processor 201 is used to process multicarrier signals in a wide variety of systems and devices including, but not limited to radio systems, audio systems, radar systems, and the like. Radio receiver front-end 100 processes a multicarrier signal comprising a plurality, P, of carrier signals, each of which is individually situated in one of a plurality, P, of distinct frequency bands. Any group of frequency bands can be employed, including those frequency bands having varying widths and non-contiguous frequency bands. The grouping of frequency bands defines a frequency range R. FIG. 7 schematically depicts the spectral content of a typical multicarrier signal comprising nine constituent carrier signals, labeled S1 to S9, each of which is situated in a distinct frequency band. The dynamic range of the multicarrier signal is 70 dB (the difference in magnitude between the strongest constituent carrier signal, S3, and the weakest constituent carrier signal, S5). According to the present invention, the dynamic range of the multicarrier signal in FIG. 7 is reducible by 40 dB, as shown in FIG. 8, by attenuating the power of signals S3 and S6 by 20 dB and boosting the power of signal S5 by 20 dB. As a result, the dynamic range of the processed signal of FIG. 8 is 30 dB. With continued reference to FIG. 2, one or more multicarrier signal processors, represented by 201M, is typically employed in radio receiver front-end 100 to reduce the dynamic range of a group of P carrier signals of a multicarrier signal. The radio receiver front-end generally comprises antenna 101, bandpass filter 105, multicarrier signal processor 201, amplifier 107, mixer 117, and local oscillator 125. The radio receiver front-end components are selected from any components or group of components which perform the stated functions, and will not be described in detail. Further description of radio components such as those used in receiver front-end 100 is found in Hickman, Newnes Practical RF Handbook, (Newnes, Oxford), c. 1993, the disclosure of which is incorporated by reference herein. Wireless telecommunications systems employ radio receivers incorporating radio receiver front end 100 at several positions within a system. FIG. 9 depicts wireless telecommunications system 800, partitioned into a number of geographically distinct areas called cells. Cell 810 is schematically depicted as a hexagon, however, in practice a cell typically has an irregular shape depending upon the topography of the terrain serviced by the wireless telecommunications system. Within cell 810 is provided cell site 820 which typically includes base station 822 cooperating with antenna 824. Radio receiver front end 100 is typically incorporated within the base station of cell site 820. Wireless terminals 840 communicate with cell site 820 via radio links. As used herein, the expression wireless terminals refers to any communications device which receives or transmits an electromagnetic signal through space including, but not limited to, mobile telephones, pagers, and personal communicators. Cell site 820 optionally communicates with a wireless switching center (WSC) 850. A wireless switching center typically comprises a large switch (e.g., the 5ESS® switch available from AT&T Corp.) that routes calls to and from wireless terminals in the wireless system and, if necessary, to and from the public switched telephone network (PTSN) via a local office switch 860. Detailed descriptions of wireless telecommunications systems are found in Lee, Mobile Cellular Telecommunications Systems, (McGraw-Hill, N.Y.), c. 1989, Lee, Mobile Communications Design Fundamentals, (Wiley-Interscience), c. 1993, Transmission Systems For Communications, (Bell Telephone Laboratories, NJ), c. 1982, Rey, Ed. Engineering and Operations in the Bell System, (AT&T Bell Laboratories, Murray Hill, N.J.), c. 1983, and Young, Wireless Basics., (Intertec, Chicago), c. 1992, the disclosures of which are incorporated herein by reference. In the frequency range of interest, R, a multicarrier signal typically comprises a plurality of carrier signals with greatly disparate relative powers, i.e., a signal with a large dynamic range. Large dynamic range multicarrier signals negatively impact the performance of numerous system components with limited dynamic ranges such as mixers, amplifiers, and analog-to-digital converters. For example, when the physical dynamic range of mixer 117 is less than the dynamic range of the multicarrier signal, mixer 117 can introduce intermodulation products into the multicarrier signal. The intermodulation products interfere with the carrier signals, creating a distorted multicarrier signal. Multicarrier signal processor 201 mitigates such problems in an exemplary embodiment by analyzing the multicarrier signal to determine the relative power of each of the constituent carrier signals. Based on the analysis, the multicarrier signal processor targets one or more of the constituent carrier signals whose power is beyond a particular range, the range being preset or determined from the multicarrier signal analysis. The multicarrier signal processor samples the multicarrier signal and sends at least one sampled multicarrier signal to a signal modifier that changes the phase and/or amplitude of the targeted constituent carrier signal. The targeted constituent signal is selected from an individual frequency band or a block or frequency bands, depending upon system needs. The modified signal is injected back into the unmodified multicarrier signal in a feedforward architecture. In this manner, the modified signal interacts with the corresponding unmodified constituent carrier signal to reduce the overall dynamic range of the multicarrier signal. Multicarrier signal processor 201 reduces the dynamic range of a multicarrier signal in an exemplary embodiment depicted in FIG. 3. FIG. 3 depicts a block diagram of the processor 201, which comprises amplifier 390, signal divider 301, signal combiner 303, delay 305, controller 307, and one or more individual signal modifiers, represented by 35N. As used herein, N represents the number of individual signal modifiers in a given embodiment. While there can be any number, N, of individual signal modifiers for a particular application, N is typically less than P. Furthermore, while the number of individual signal modifiers used in an embodiment is selected based on system considerations, larger numbers of individual signal modifiers generally increase the ability of the multicarrier signal processor to reduce the dynamic range of a multicarrier signal. Alternatively, the individual signal modifiers of the present invention can be cascaded in series such that a multicarrier signal is sequentially processed by the individual signal modifiers. As depicted in FIG. 3, the incoming multicarrier signal is processed by signal divider 301. Signal divider 301 receives the multicarrier signal and takes N+2 samples of it, each of which is typically an analog representation of the multicarrier signal. Signal divider 301 places one sample of the multicarrier signal onto each of signal paths 311, 315, 371, . . . , 37N-1 and 37N. Preferably, signal divider 301 is fabricated so that the majority of the power of the multicarrier signal is put onto signal path 311. Signal divider 301 is advantageously selected from compound splitters, which generally comprise a combination of 1:2 or 1:3 Wilkinson or hybrid couplers. However, any element which takes an incoming signal and provides plural outputs can be used as signal divider 301. One of the sampled signals is placed on signal path 315 and fed to controller 307. Controller 307 receives this multicarrier signal sample and performs several functions. First, the controller analyzes the multicarrier signal to determine the relative power of each of the carrier signals. This may be done on all of the carrier signals simultaneously (e.g., with a fast fourier transform) or serially by scanning for individual carrier signals, one at a time, across the frequency range, R. In an exemplary embodiment, controller 307 is programmed with a threshold power. The threshold is typically a range selected such that any constituent carrier signal having a power below the threshold lower limit is amplified and any constituent carrier signal having a power above upper limit is attenuated. In this manner, individual carrier signals with power levels that are excessively high or excessively low relative to the other carrier signals are automatically attenuated or automatically amplified. This threshold programming may be performed in any known manner. In an exemplary embodiment, the multicarrier signal processor operates with CDMA (code division multiple access) systems such that the CDMA equipment is not overwhelmed by signals from analog systems. In this embodiment, the multicarrier signal comprises both CDMA signals, i.e., spread-spectrum-modulated signals, and higher-powered analog signals, e.g., amplitude-modulated and frequency-modulated signals. Controller 307 is preset with a upper threshold which eliminates the substantially higher-powered analog signals. In this embodiment, the controller instructs the individual signal modifiers to modify the large carrier signal such that the modified signal, when combined with the unmodified multicarrier signal, substantially eliminates the large carrier signal. In a CDMA system, the controller is typically positioned in the CDMA receiver after the bandpass filter, such that the mixer and other dynamic-range-sensitive components are not influenced by the higher-powered analog signals. After analyzing the incoming multicarrier signal, controller 307 directs individual signal modifiers 351, . . . 35N-1, 35N via pathways 341 . . . 34N-1, 34N to isolate and modify a particular constituent carrier signal from the multicarrier signal. Each individual signal modifier, 351 . . . 35N-1, 35N, respectively receives an unmodified multicarrier signal sample from signal divider 301 through paths 371 . . . 37N-1, 37N. The individual signal modifier isolates its targeted constituent carrier signal or block of carrier signals as directed by controller 307, and modifies it. In an exemplary embodiment, the phase and/or amplitude of the targeted signal is/are changed in preparation for injection back into the unmodified multicarrier signal. For a constituent carrier signal having a large amplitude, the amplitude can be decreased by the signal modifier. In particular, a constituent carrier signal can be created having the same amplitude but 180° out of phase with the corresponding unmodified constituent carrier signal. To boost the amplitude, the constituent carrier signal can be created having the same amplitude and in phase with the constituent carrier signal. For either modification technique, the strength of the constituent carrier signal within the multicarrier signal is reduced or increased upon combination with the corresponding unmodified constituent carrier signal. The modified constituent carrier signals are output through signal pathways 381, 38N-1, 38N to signal combiner 303 for combination with the unmodified multicarrier signal. Signal combiner 303 receives N+1 signals: one from signal path 311 and one from each of the N individual signal modifiers through pathways 381 . . . 38N-1, 38N, and injects the modified isolated signals back into the unmodified multicarrier signal. Typically, combiner 303 creates an output signal that is the vector sum of all N+1 signals. Signal combiner 303 is generally selected from any compound splitter, particularly, compound splitters which comprise a combination of 1:2 or 1:3 Wilkinson or hybrid couplers. However, any component which combines signals received from plural pathways can be employed as signal combiner 303. The signal sample received from path 311 is a delayed, unmodified multicarrier signal. Delay 305 in signal path 311 is preferably set so that the delay through signal path 311 is equal to the delay through signal paths 37N, individual signal modifiers 35N and signal paths 38N. Delay elements impart a negative phase slope to the signal upon which they act. Delay 305 and the phase shift imparted by each individual signal modifier must be carefully coordinated so that signal combiner 303 effectively performs a vector addition of all of the signals which enter it. In other words, if individual signal modifier 35N is to attenuate a given carrier signal, delay 305 must be set so that the multicarrier signal through signal path 311 and the isolated and modified signal through individual signal modifier 35N arrive at signal combiner 303 at the same time. In the case of signal attenuation, the phase of the output signal from the individual signal modifier is shifted 180° relative to the phase of the unmodified carrier signal, so that the two signals destructively interfere. As will be discussed in detail below, in an alternate embodiment delay 305 is eliminated from signal path 311 and a negative delay element is inserted in signal paths 381, 38N-1, 38N. Negative delay elements, such as negative group delays, create signals which appear to have propagated a shorter distance than the actual path length by imparting a positive phase slope to the signal. The use of negative delay elements in signal paths 381, 38N-1, 38N, reduces the loss of the unmodified multicarrier signal in signal path 311. Since, in an exemplary embodiment, the majority of the signal strength traverses signal path 311, the overall loss in the multicarrier signal processor is reduced through the use of negative group delays. Exemplary negative group delays are described in B. J. Arntz, U.S. Pat. No. 5,291,156, issued Mar. 1, 1994, the disclosure of which is incorporated by reference herein. For the case of carrier signal amplification, the delay 305 is identical, since the time through the signal paths is the same. However, the phase of the modified carrier signal from the individual signal modifier is adjusted, relative to the phase of the respective unmodified carrier signal, so that the two signals are constructively added. Individual components of multicarrier signal processor 201 will now be described with reference to FIGS. 4-6. FIG. 4 schematically depicts an individual signal modifier 35N for use in the multicarrier signal processor. Each individual signal modifier, i.e., individual signal modifier 351, 35N-1, and 35N, isolates a targeted carrier signal and modifies its phase and/or amplitude in preparation for being injected back into the unmodified multicarrier signal. The individual signal modifier of FIG. 4 includes mixer 401, bandpass filter 403, phase-shifter 405, amplitude modifier 407, mixer 409, amplifiers 411, 415, and 417, and programmable synthesizer 413. Typically, class A amplifiers are used in individual signal modifier 35N, as well as throughout multicarrier signal modifier 201, as will be described below. A sample of the multicarrier signal enters mixer 401 from signal path 37N. Mixer 401 mixes down the multicarrier signal, so that bandpass filter 403 can isolate the constituent carrier signal targeted for modification by controller 307. Programmable synthesizer 413 directs mixer 401 to shift the incoming multicarrier signal such that the targeted carrier signal is positioned at the pass frequency of bandpass filter 403. In this manner, the carrier signal targeted by controller 307 is isolated from the multicarrier signal by bandpass filter 403. Amplifier 415 amplifies the signal which is fed to band pass filter 403. The carrier signal that is isolated by bandpass filter 403 will be referred to as an isolated carrier signal. Bandpass filter 403 is typically a high Q bandpass filter with a passband equal to the frequency bandwidth of the targeted signal or block of signals. The isolated carrier signal exits bandpass filter 403, is amplified by amplifier 417, and is fed to phase shifter 405. Phase-shifter 405 selectively changes the phase of the isolated carrier signal by a given number of degrees. For example, by shifting the phase of the signal such that the signal is 180° out-of-phase with the unmodified carrier signal, the modified carrier signal destructively interferes with the unmodified carrier signal. When the modified signal is to constructively add with the unmodified carrier signal, the phase shifter is set such that the modified and unmodified carrier signals are in phase with one another. In this manner, the modified isolated carrier signal from the individual signal modifier, when injected back into the multicarrier signal by signal combiner 303, interacts with the corresponding unmodified carrier signal by destructively interfering or constructively adding with the unmodified carrier signal to reduce the overall dynamic range of the multicarrier signal. Phase-shifter 405 is provided with either a fixed phase shift, i.e., a phase shift preset for a given number of degrees, or it is provided with a variable capability that is controlled by controller 307. In an exemplary embodiment, phase shifter 407 is programmable such that it adjusts the phase of the signal according to its frequency. Following phase shifter 405, the isolated carrier signal next enters amplitude modifier 407. While amplitude modifier 407 is illustratively depicted as an attenuator, it is selected from elements that can amplify, attenuate, or alternatively amplify or attenuate an incoming signal, e.g., amplifiers which are capable of both attenuating and amplifying. The amount by which signal modifier 407 either amplifies or attenuates the isolated carrier signal is selected to be either fixed or variable, depending upon system considerations. When the amount is variable, controller 307 directs the amount of attenuation or amplification to be produced by amplitude modifier 407. While each individual signal modifier can either attenuate or amplify the isolated carrier signal, in an exemplary embodiment signals are only attenuated. Attenuation of signals tends to result in an overall better noise figure for the multicarrier signal processor. In this embodiment, amplitude modifier 407 is selected to be an attenuator. Typically, the isolated carrier signal is attenuated by approximately 5 to 15 dB. Following signal modification, the modified isolated carrier signal enters mixer 409, which mixes up the modified isolated carrier signal, as directed by programmable synthesizer 413, to the frequency band in which the carrier signal resided prior to mixing down by mixer 401. The modified isolated carrier signal is amplified by amplifier 411, then output to signal combiner 303 via path 38N. Multiple amplifiers distributed along the signal path generally create better noise reduction than a single amplifier, although such single amplifier may be satisfactory. Following vector combination in signal combiner 303, the modified multicarrier signal is optionally input to another multicarrier signal processor serially connected to the previous multicarrier signal processor. This arrangement provides further reduction in the dynamic range of a multicarrier signal. FIG. 5 depicts a block diagram of an illustrative embodiment of controller 307A, in which the multicarrier signal is analyzed with a fast fourier transform. In this embodiment, controller 307A includes mixer 501, local oscillator 511, bandpass filter 503, analog-to-digital converter 505, fast-fourier transform analyzer 507, digital signal processor 509, and amplifiers 520 and 522. The multicarrier signal received from signal divider 301 via signal path 315 is mixed down by mixer 501 to an intermediate frequency, in well-known fashion. Mixer 501 is controlled by local oscillator 511. The mixed-down signal is amplified by amplifier 520 and input to bandpass filter 503. Bandpass filter 503 is preferably a high Q filter with a passband width equal to the frequency range, R, of interest. The filtered multicarrier signal is amplified by amplifier 522 and passed to analog-to-digital converter 505. Analog-to-digital converter 505 converts the analog output of bandpass filter 503 to a digital format for analysis by fast-fourier transform 507. Fast-fourier transform 507 takes the multicarrier signal and produces its spectral content, as illustrated in FIGS. 7 and 8. Digital signal processor 509 takes the output of fast-fourier transform 507, analyzes its dynamic range, and identifies which carrier signals should be attenuated or amplified. Digital signal processor 509 may also specify the amount of attenuation or amplification. In one embodiment, digital signal processor 509 also determines the amount of phase shift for each targeted carrier signal or block of carrier signals. Additionally, digital signal processor 509 sends a signal to each individual signal modifier indicating which targeted carrier signal the individual signal modifier is to isolate for attenuation or amplification. FIG. 6 depicts a block diagram of an alternate embodiment of controller 307B, which analyzes the multicarrier signal by scanning across it for individual carrier signals in sequential fashion. In this embodiment, controller 307B comprises mixer 601, programmable synthesizer 611, bandpass filter 603, amplitude detector 605, analog-to-digital converter 607, digital signal processor 609, and amplifiers 620 and 622. Mixer 601 mixes down the multicarrier signal from signal path 315 to an intermediate frequency, as directed by programmable synthesizer 611. The mixed-down signal is amplified by amplifier 620 and sent to bandpass filter 603. Bandpass filter 603 is typically a high Q filter with a passband width equal to the frequency range of interest. The signal is amplified by amplifier 622. Amplitude detector 605 takes the filtered multicarrier signal and determines the average power of the individual scanned signal, in well-known fashion. Analog-to-digital converter 607 converts the analog output of amplitude detector 605 to a digital format for use by digital signal processor 609. Digital signal processor 609 determines the amplitude of the carrier signal being analyzed, and directs programmable synthesizer 611 to serially tune to a different carrier signal until all of the carrier signals in the multicarrier signal have been analyzed. Additionally, digital signal processor 609 determines which carrier signals should be targeted for attenuation or amplification. Digital signal processor 609 directs each individual signal modifier by sending a signal indicating which carrier signal that individual signal modifier is to isolate and attenuate or amplify and, optionally, the amount of carrier signal amplification or attenuation. Numerous advantages are realized through the use of the multicarrier signal processors of the present invention. For example, conventional systems typically employ filters in the position of filter 105 which are expensive to produce and bulky to install at cell sites. Such filters are needed in conjunction with conventional receivers to prevent interference between the bands of the A and B carriers within a cellular market. The present invention permits the use of smaller, less expensive filters in the receiver since the multicarrier signal processor essentially creates the effect of an ideal filter. Exemplary filters for use with the present invention are barium titanate duplex filters. Barium titanate duplex filters are described in U.S. Pat. No. 3,938,064, the disclosure of which is incorporated herein by reference. Turning now to FIG. 10, another illustrative embodiment of multicarrier signal processor, designated generally by reference numeral 701, reduces the dynamic range of a multicarrier signal. FIG. 11 depicts a block diagram of the processor 701, which comprises signal divider 702, signal combiner 703, controller 707, and one or more individual signal modifiers, represented by 75N. As used above, N represents the number of individual signal modifiers in a given embodiment. Multicarrier signal processor 701 operates substantially as described above with regard to signal processor 201, with the differences described hereinbelow. In particular, delay 305 is eliminated from signal path 711 and a negative delay element is inserted in auxiliary path 79N, consisting of signal path 77N, individual signal modifier 75N, and signal path 78N. As depicted in FIG. 11, the incoming multicarrier signal is processed by signal divider 702. Signal divider 702 receives the multicarrier signal, takes N+2 samples of it, and places one sample of the multicarrier signal onto each of signal paths 711, 715, 771, . . . , 77N-1 and 77N. Preferably, signal divider 702 is fabricated so that the majority of the power of the multicarrier signal is put onto signal path 711. Substantial delay is imparted to the signal passing through auxiliary path 79N, in the order of microseconds. Narrow band pass filters in the individual signal modifiers add a significant delay to the signal. In order to equalize the delay in the auxiliary path with the delay in path 711, a long delay may be necessary, which can introduce significant loss to the system and desensitize signal path 711. A negative delay in the auxiliary path equalizes the delays in path 711 and auxiliary path 79N while introducing minimal losses and not degrading the sensitivity of the system. One of the sampled signals is placed on signal path 715 and fed to controller 707. Controller 707 receives this multicarrier signal sample and performs several functions. First, the controller analyzes the multicarrier signal to determine the relative power of each of the carrier signals in order to detect low carrier signals to be amplified or to detect large carrier signals to be attenuated. In this embodiment, the controller instructs the individual signal modifiers to modify the large carrier signal such that the modified signal, when combined with the unmodified multicarrier signal, substantially eliminates the large carrier signal. The controller is typically positioned in the CDMA receiver after the bandpass filter, such that the mixer and other dynamic-range-sensitive components are not influenced by the higher-powered analog signals. After analyzing the incoming multicarrier signal, controller 707 directs individual signal modifiers 751, . . . 75N-1, 75N via pathways 741 . . . 74N-1, 74N to isolate and modify a particular constituent carrier signal from the multicarrier signal. Each individual signal modifier, 751 . . . 75N-1, 75N, respectively receives an unmodified multicarrier signal sample from signal divider 702 through paths 771 . . . 77N-1, 77N. The individual signal modifier isolates its targeted constituent carrier signal or block of carrier signals as directed by controller 707, and modifies it. In an exemplary embodiment, the phase and/or amplitude of the targeted signal is/are changed in preparation for injection back into the unmodified multicarrier signal. For a constituent carrier signal having a large amplitude, the amplitude can be decreased by the signal modifier. A constituent carrier signal can be created having the same amplitude but 180° out of phase with the corresponding unmodified constituent carrier signal. The strength of the constituent carrier signal within the multicarrier signal is reduced upon combination with the corresponding unmodified constituent carrier signal. The modified constituent carrier signals are output through signal pathways 781, 78N-1, 78N to signal combiner 703 for combination with the unmodified multicarrier signal. Signal combiner 703 receives N+1 signals: one from signal path 711 and one from each of the N individual signal modifiers through pathways 781 . . . 78N-1, 78N, and injects the modified isolated signals back into the unmodified multicarrier signal. Typically, combiner 703 creates an output signal that is the vector sum of all N+1 signals. FIG. 12 schematically depicts an individual signal modifier 75N for use in an alternative embodiment of the multicarrier signal processor. Each individual signal modifier, i.e., individual signal modifier 751, 75N-1, and 75N, isolates a targeted carrier signal and modifies its phase and/or amplitude in preparation for being injected back into the unmodified multicarrier signal. The individual signal modifier of FIG. 11 comprises mixer 720, negative delay 722, bandpass filter 724, phase-shifter 726, amplitude modifier 728, mixer 730, amplifiers 732, 736, and 737, and programmable synthesizer 734. Typically, amplifiers 732, 736, and 737 are class A amplifiers. A sample of the multicarrier signal enters mixer 720 from signal path 77N. Mixer 720 mixes down the multicarrier signal to an intermediate frequency, so that bandpass filter 724 can isolate the constituent carrier signal targeted for modification by controller 707 (FIG. 11). Programmable synthesizer 734 directs mixer 720 to shift the incoming multicarrier signal such that the targeted carrier signal is positioned at the pass frequency of bandpass filter 724 as will be discussed below. Negative delay element 722 receives the signal from mixer 720 at the intermediate frequency and amplified by amplifier 736. Negative delay element 722 can be the negative group delay disclosed in B. J. Arntz, U.S. Pat. No. 5,291,156, issued Mar. 1, 1994. Negative delay element 722 creates a signal which appears to have travelled a shorter distance than the actual path length by imparting a positive phase slope in the band of operation. The magnitude of the negative delay imparted by negative delay element 722 is preferably set to compensate for the delay through auxiliary path 79N, consisting of signal paths 77N, individual signal modifier 75N and signal paths 78N (FIG. 11). Negative delay 722 may incorporate a non-adjustable positive phase slope or an electrically adjustable phase slope to enable the magnitude of the delay to be adjusted at will without physically changing the length of the signal path which the input signal traverses. Negative delay 722 and the phase shift imparted by each individual signal modifier must be carefully coordinated such that the signal combiner 702 effectively performs a vector addition of all the signals which enter it. If individual signal modifier 75N is to attenuate a given carrier signal, negative delay 722 must be set so that the multicarrier signal through signal path 711 and the isolated and modified signal through individual signal modifier 75N arrive at a signal combiner at the same time. In the case of signal attenuation, the phase of the output signal from the individual signal modifier is shifted 180° relative to the phase of the unmodified carrier signal so that the two signals destructively interfere. The signal is amplified by amplifier 737. The carrier signal targeted by controller 707 is positioned at the pass frequency of band pass filter 724 and is isolated from the multicarrier signal by bandpass filter 724. The carrier signal that is isolated by bandpass filter 724 will be referred to as an isolated carrier signal. As described above, bandpass filter 724 is typically a high Q bandpass filter with a passband equal to the frequency bandwidth of the targeted signal or block of signals. The isolated carrier signal exits the bandpass filter, is amplified by amplifier 738, and is fed to phase shifter 726. Phase-shifter 726 selectively changes the phase of the isolated carrier signal by a given number of degrees. For example, by shifting the phase of the signal such that the signal is 180° out of phase with the unmodified carrier signal, the modified carrier signal destructively interferes with the unmodified carrier signal. When the modified signal is to constructively add with the unmodified carrier signal, the phase shifter is set such that the modified and unmodified carrier signals are in phase with one another. In this manner, the modified isolated carrier signal from the individual signal modifier, when injected back into the multicarrier signal by signal combiner 703, interacts with the corresponding unmodified carrier signal by destructively interfering or constructively adding with the unmodified carrier signal to reduce the overall dynamic range of the multicarrier signal. Following phase shifter 726, the isolated carrier signal next enters amplitude modifier 728. In this embodiment, amplitude modifier 728 is selected to be an attenuator. Typically, the isolated carrier signal is attenuated by approximately 5 to 15 dB. Following signal modification, the modified isolated carrier signal enters mixer 730. Mixer 730 mixes up the modified isolated carrier signal, as directed by programmable synthesizer 734, to the frequency band in which the carrier signal resided prior to mixing down by mixer 720. The modified isolated carrier signal is amplified by amplifiers 732, then output to signal combiner 703 via path 78N. Alternatively, a single amplifier may be used. Referring back to FIG. 11, following vector combination in signal combiner 703, the modified multicarrier signal is optionally input to another multicarrier signal processor serially connected to the previous multicarrier signal processor. This arrangement provides further reduction in the dynamic range of a multicarrier signal. The present invention advantageously reduces the dynamic range of a multicarrier signal without eliminating carrier signals and the information which they carry. Because individual carrier signals are merely attenuated or amplified, only the dynamic range is reduced without excluding the information-carrying frequency bands of the multicarrier signal. While the foregoing invention has been described in terms of the exemplary embodiments, it will be readily apparent that numerous changes and modifications can be made. Accordingly, modifications such as those suggested above, but not limited thereto, are considered to be within the scope of the claimed invention. What is claimed is: 1. A multicarrier signal processor for processing a multicarrier signal, the multicarrier processor comprising:a controller configured to receive at least a portion of the multicarrier signal, the controller analyzing the multicarrier signal to identify at least one carrier signal of the multicarrier signal to be modified; and at least one signal modifier, the signal modifier configured to receive the at least portion of the multicarrier signal, to isolate the at least one carrier signal to be modified as directed by the controller, to impart a negative delay to the carrier signal and to modify the isolated carrier signal to interact with a corresponding unmodified carrier signal. 2. The multicarrier signal processor of claim 1 further comprising a signal divider for receiving an incoming carrier signal and placing the at least portion of the multicarrier signal on plural output paths. 3. The multicarrier signal processor of claim 2 wherein one of said plural output paths is an input path for the controller. 4. The multicarrier signal processor of claim 2 wherein one of said plural output paths is an input path for the at least one signal modifier. 5. The multicarrier signal processor of claim 1 wherein the at least one signal modifier modifies the carrier signal by altering the phase and/or amplitude of the carrier signal. 6. The multicarrier signal processor of claim 1 further comprising a signal combiner for combining a modified carrier signal with an unmodified multicarrier signal. 7. The multicarrier signal processor of claim 1 wherein the signal modifier includes a programmable synthesizer communicating with the controller and a mixer communicating with a bandpass filter. 8. The multicarrier signal processor of claim 1 wherein the signal modifier includes a phase shifter and an amplitude modifier. 9. A multicarrier signal processor for processing a multicarrier signal, the multicarrier processor comprising:a controller configured to receive at least a portion of the multicarrier signal, the controller analyzing the multicarrier signal to identify at least one carrier signal of the multicarrier signal to be modified; and at least one signal modifier, the signal modifier configured to receive the at least portion of the multicarrier signal, to isolate the at least one carrier signal to be modified as directed by the controller, to impart a positive phase slope to the carrier signal and to modify the isolated carrier signal to interact with a corresponding unmodified carrier signal. 10. The multicarrier signal processor of claim 9 further comprising a signal divider for receiving an incoming carrier signal and placing the at least portion of the multicarrier signal on plural output paths. 11. The multicarrier signal processor of claim 10 wherein one of said plural output paths is an input path for the controller. 12. The multicarrier signal processor of claim 10 wherein one of said plural output paths is an input path for the at least one signal modifier. 13. The multicarrier signal processor of claim 9 wherein the at least one signal modifier modifies the carrier signal by altering the phase and/or amplitude of the carrier signal. 14. The multicarrier signal processor of claim 9 further comprising a signal combiner for combining a modified carrier signal with an unmodified multicarrier signal. 15. The multicarrier signal processor of claim 9 wherein the signal modifier includes a programmable synthesizer communicating with the controller and a mixer communicating with a bandpass filter. 16. The multicarrier signal processor of claim 9 wherein the signal modifier includes a phase shifter and an amplitude modifier. 17. A method for processing a multicarrier signal, the method comprising:a) receiving at least a portion of the multicarrier signal in a controller; b) analyzing the multicarrier signal in the controller to identify at least one carrier signal to be modified; c) receiving the at least portion of the multicarrier signal in a signal modifier for isolating the carrier signal to be modified and changing at least one signal characteristic of the carrier signal such that the modified carrier signal abates the multicarrier signal; d) directing the signal modifier to isolate the carrier signal identified by the controller; e) modifying the carrier signal; f) imparting a negative delay to the carrier signal; and g) sending the modified carrier signal to an output port for combination with the multicarrier signal. 18. The method of claim 17 further comprising combining the modified carrier signal with the multicarrier signal. 19. The method of claim 18 wherein the multicarrier signal has associated therewith a dynamic range, and said step of combining the multicarrier signal with an unmodified carrier signal reduces the dynamic range of the multicarrier signal. 20. An apparatus for processing a multicarrier signal comprising a plurality of carrier signals, the apparatus comprising:a) a signal divider for creating at least a first signal, a second signal, and a third signal based on the multicarrier signal and for putting the first signal onto a first signal path, the second signal onto a second signal path, and the third signal onto a third signal path; b) a signal combiner for receiving the first signal from said first signal path, and a modified third signal from the third signal path, the signal combiner creating an output signal based on the sum of the first signal and the modified third signal; c) an individual signal modifier in the third signal path for isolating, from said third signal, a carrier signal and for modifying the phase and/or amplitude of the carrier signal to create the modified third signal; and d) a controller for receiving the second signal from the second signal path, the controller analyzing the second signal to determine the relative power of the carrier signals which comprise the second signal, the controller identifying at least one carrier signal to be isolated by the individual signal modifier; and e) a negative delay element in the third signal path for equalizing the delay of the third signal in the third signal path with the delay of the first signal in the first signal path. 21. The apparatus of claim 20 wherein the individual signal modifier comprises:a mixer for mixing down said third signal; a bandpass filter for isolating a carrier signal from said third signal; an amplitude modifier for modifying the amplitude of said first isolated signal; a phase-shifter for modifying the phase of the isolated signal; and a second mixer mixing up the isolated signal to create said modified third signal. 22. The apparatus of claim 20 wherein:the individual signal modifier isolates the carrier signal using a bandpass filter based on a first band designator; and the controller generates said first band designator such that the carrier signal targeted by the controller for isolation is positioned at a pass frequency of the bandpass filter. 23. A method for processing a multicarrier signal comprising a plurality of carrier signals, comprising:a) creating, based on the multicarrier signal, at least a first signal, a second signal, and a third signal such that the first signal, the second signal and the third signal are analog representations of the multicarrier signal; b) analyzing the second signal to determine the relative power of each of the carrier signals which comprise the multicarrier signal to produce an analysis; c) identifying, based on said analysis, at least one of the carrier signals to be modified; d) isolating the at least one carrier signal to be modified and modifying the phase and/or amplitude of the isolated carrier signal to create a modified third signal; e) imparting a negative delay to the modified third signal to equalize the delay of the third signal with the delay of the first signal; and f) combining the first signal and the modified third signal. 24. A signal modifier for modifying at least one carrier signal of a multicarrier signal comprising:a) a mixer configured to receive the multicarrier signal; b) a filter for receiving the output of the mixer, the filter having a bandpass frequency; c) means communicating with the mixer for shifting the multicarrier signal such that at least one carrier signal to be modified is positioned at the bandpass frequency of the filter; d) a phase shifter for modifying the at least one carrier signal passed by the filter; and e) a delay element for imparting a negative group delay to the multicarrier signal.

1995-12-29

en

1997-12-02

US-47371454-A

Process for purifying and separating b12-group-vitamins by partition chromatography on cellulose columns Oct. 8, 1957 PROCESS FOR PURIFYING AND SEPARATING B -GROUPVITAMINS BY PARTITION CHROMATOGRAPHY ON CELLULOSE COLUMNS Filed Dec. 7, 1954 2 Sheets-Sheet 1 Fig.1 Without KCIO4 Fact. I ll Fuct.A ' With KCIO4 mvsmozzg KONRAD BERNI-I-AUER W/L HELM FRIEDRICH ATTORNEYS b Value Without KCI04 Oct. 8, 1957 PROCESS FOR PURIFYING BERNHAUER ETAL AND SEPARATING B -GROUPVITAMINS Y PARTITION CHROMATOGRAPHY ON CELLULOSE COLUMNS Filed Dec. 7, 1954 Without KC|O4 Fig.2 WifhOuf 2 Sheets-Sheet 2 KCI 04 Wlth KCI 0 Water IN VENTORS K ONRA D BER/VHA U57? WIL HE L M FR/EDR/Ch' a r F 4' AM... f hum" ATTORNEYS PROCESS FDR PURIFYING SEPARATING Bn-GROUP-VITAMINS BY PARTITION (SHED- MATOGRAPHY ON CELLULOSE COLUMNS Konrad Bernhauer and Wilhelm Friedrich, Aschairenburg, Germany, assignors to Aschaffenburger Zellstoifwerkc Aktiengesellschaft, Redenfelden, Upper Bavaria, Germany, a corporation of Germany Application December 7, 1954, Serial No. 473,714 Claims priority, application Germany December 10, 1953 16 Claims. (Cl. 167-81) This invention relates to a process for purifying and separating Biz-group-vitamins by partition chromatography on cellulose columns. In the isolation of vitamin B12 and other factors of the Biz-group and after adsorption, elution, extraction, and precipitation processes, a rather complicated composition of different kinds of vitamin B12 is often obtained, in particular if digested sludge is used as starting material (see W. Friedrich and K. Bernhauer, Angewandte Chemie 65, 627 (1953); K. Bernhauer and W. Friedrich (Aschaifenberger Zellstotfwerke A. G.), DBP 922 126). Very efiective processes are required for the further purification and separation of these compositions since the individual components mostly differ only very little from one another in chemical and physical respect. In most cases such compositions do not crystallize; and in case crystallization does take place'mixed crystals are obtained because mostly part of the Biz-group-vitamins is isomorphous (for instance vitamin B12 and factor III). At present, the separation of such compositions with the aid of countercurrent distribution is hardly practicable on a technical scale as it would require very complicated apparatuses and very great amounts of solvents. For some time in adsorption chromatographic methods aluminum oxide has been used as adsorbent and diiferent organic liquids (mixtures of water and acetone respectively diethylene dioxide (dioxan) or methyl alcohol) have been used as solvents (eluents). When that method has been applied to compositions of vitamin Biz-factors obtainable from digested sludge and which always contain four kinds of vitamin B12 at the least, it has only been successful when the development was'carried out using acetone of increasing water content in the presence of cyanide, whereby it was possible to separate the faster migrating kinds of vitamin B12. The factor III thus obtained, however, always contained, even when crystalnited States Patent lized, among other substances, considerable amounts of vitamin B12. It was extremely difficult-also when using a developer containing a great quantity of waterto elute the factors V which migrate even more slowly (see W. Friedrich and K. Bernhauer, Angewandte Chemie 65, 627 (1953)). Of the partition chromatographic systems, silica-gel together with aqueous alcohols respectively phenols has so far mostly been employed. Thus vitamin B1 has been purified (see E. Lester Smith and L. F. I. Parker, Biochem. Soc., Proc. of 9.5. 1948; E. Lester Smith, W. F. J. Cuthbertson, A. Walker and K. A. Lees, Fed. Proc. 9, No. 1 (1950); K. H. Fantes, J. E. Page, L. F. I. Parker and E. Lester Smith, Proc. Roy. Soc. B 136, 592 (1950)) in silica-gel columns using n-butyl alcohol, n-propyl alcohol, and isopropyl alcohol of suitable water contents as developers, eventually adding phenol or cresol. Furthermore it has been tried in this way to separate the vitamin- Biz-active substances from feces (see U. J. Lewis, D. F. Tappan and C. A. Elvehjem, J. Biol. Chem. 194, 539 (1952); I. E. Ford and l. W. G. Porter, Biochem. J. 51, Proc. V. (1952)), employing therewith water-saturated n-butyl-alcohol respectively sec. butyl alcohol as developer, but without obtaining any satisfactory effect. When this method was applied to vitamin Biz-factors from digested sludge and alcohols having the usual water content and completely miscible with water as well as cyanide as developer were used, a separation was not obtained. Water-saturated sec. butyl alcohol acted similarly under the same conditions. A partial separation was obtained by using water-saturated n-butyl alcohol. In this case it was, however, necessary to employ great quantities of the developer, and the process lasted several days. In some cases, starch was used for separating vitamin B12 and BlZb instead of silica-gel (see E. Lester Smith and L. F. J. Parker, Biochem. Soc. Proc. of May 29, 1948; E. Lester Smith, W. F. I. Cuthbertson, A. Walker and K. A. Lees, Fed. Proc. 9, No. 1 (1950)). But starch columns have proved a failure in separating compositions of Biz-group-vitamins from digested sludge, as diffuse chromatograms without the formation of zones were always obtained. Now, in accordance with the present invention, the surprising and important observation has been made that chromatographic columns of cellulose in the form of powder or flakes are exceedingly Well suited for separating complicated compositions of Biz-group-vitamins. Heretofore, cellulose has only been employed (in the form of strips respectively sheets of paper) in paper chromatography of Biz-vitamins, and different developers have been used therewith. Water-saturated n-butyl alcohol which was employed among other substances for separating vitamin B12 and desoxyribosides has proved the least suitable. (See W. A. Winsten and E. Eigen, J. Biol. Chem. 177, 989; 181, 109 (1949)). It was furthermore used for separating vitamin B12 and the factors WAB, WR and B12 (see H. G. Wijmenga, Dissertation, Utrecht (1951)), although hours were required therefor. For separating vitamin Biz-factors from feces the said developer was also used (see W. J. Lewis, D. F. Tappan and C. A. Elvehjem, J. Biol. Chem. 194, 539 (1952)). An increase of the Rr-values being very low, a certain acceleration of the migration velocity resulting therefrom was obtained by saturating the paper strips with 0.66 m. KH2PO4 (see H. G. Wijmenga, Dissertation, Utrecht (1951)). However, the dispersion did not improve essentially therebysince the respective factors were subsequently found to be non-uniform (see E. S. Holdsworth, Nature 171, 148 (1953)). A similar acceleration of the migration velocity could be obtained by adding glacial acetic acid to n-butyl-alcohol-water (see H. G. Wijmenga, Dissertation, Utrecht (1951)). The application of water-saturated sec. butyl alcohol proved an essential advance in paper chromatography. (See K. H. Fantes, J. E. Page, L. F. J. Parker and E. Lester Smith, Proc. Roy. Soc. B 136, 592 (1950)). When applying this system, as Well as water-saturated sec. butyl alcohol with an addition of glacial acetic acid, the factors III, A and pseudovitamin B12 either cannot be separated from one another, or the separation is only inadequate (see I E. Ford, Physiol. Rev., being printed). These results in paper chromatography-which are as yet rather unsatisfactory-could not serve as a guide in elaborating the process according to the present invention. Both methods, i. e. paper chromatography and column chromatography, differ essentially from each other; and the developers suitable for one method are not always to be applied to the other. Water-saturated n-butyl alcohol for instance proved a complete failure in the paper chromatography of more complicated compositions of vitamin B12, whereas water-saturated sec. butyl alcohol yielded fairly satisfactory results. On the other hand, water-saturated sec. butyl alcohol was useless in column chromatography according to the inventron, whereas good separations were received in this case by using water-saturated n-butyl alcohol. As may be seen from the foregoing the kind of developer is of great importance to the chromatography on cellulose columns according to the present invention. Systematic check tests have revealed that particularly favorable effects are obtained under certain conditions explained in the following: Vitamin 12 and etiocobalamine (see K. Bernhauer and W. Friedrich, Angew. Chem. 66, 776 (1954)) may be separated easily from each other by water-saturated nbutyl-alcohol as developer, though mostly not quantitatively, since the zones of both factors are usually too broad. However, the separation of vitamin 1312 from the remaining complete factors (see K. Bernhauer and W. Friedrich, Angew. Chem. 66, 776 (1954)) has proved perfect, a broad colorless zone being between them in the chromatographing column. Using this arrangement, a complete separation of the slowly migrating vitamin-B12- factors (factor III, factor A, pseudo-vitamin B12, factors V) is not possible. Vitamin B12 may be separated as to quantity from etiocobalamine and factors which migrate in a similar way as well as from factor III by water-saturated n-butyl alchol in the presence of certain salts such as for instance perchlorates (e. g. potassiumor sodium-perchlorate). The factors III, A, pseudo, V, etc., however, migrate too slowly and therefore accumulate in too high dilutions in the eluate. When using sec. butyl alcohol containing water the separation of the different vitamin-Biz-factors is unsatisfactory. A developer having a water content of 29% has proved most favorable. In this system etiocobalamine and vitamin B12 are separated satisfactorily, whereas the slower factors migrate diffusely and are inseparable as to quantity. When the water content of the developer is increased, all zones migrate diffusely; when the water content of the developer is increased, the migration velocity of the zones is too slow. Excellent separating effects considerably exceeding the results of all other separating methods are obtained by using sec. butyl alcohol containing water in the presence of certain salts, such as for instance potassium or sodium salts of e. g. perchloric acid (HClOa), chloric acid (HClOa), bromic acid (HBrOa), nitric acid (HNOs), hydrogen tetraphenylboron (I-I/B(CsH5)4/ monochloroacetic acid (ClI-I2C.COOH), dichloroacetic acid (C1zI-IC.COOH) trichloroacetic acid (ClaCCOOH), monobromoacetic acid (B.rI-IzC.COOH), dibromoacetic acid (BrzI-IC.COOH) camphosulphonic acid, benzenesulphonic acid (CsHsSOaH) 2,4-dichlorobenzoic acid (CsHaClzCOOI-I), sulphanilic acid (H2N.CsH4.SOal-I), tic-naphthalene sulphonic acid (CH7SO3H) The concentration of these salts in the developer should be about 0.0020.02 mol per 1000 cc. Salts which are very sparingly soluble in the developer are employed as concentrated solutions. This developing system is particularly suitable when operating with increasing water content. A water content of 20-25% permits etiocobalamine and similar factors to migrate well separated, a water content of 25-28% causes the separation and elution of vitamin B12 and factors which migrate in a similar way; finally the slowly migrating Biz-kinds (factor III, pseudo-factors, factors V, etc.) are separated and eluted by water-saturated sec. butyl alcohol. Then the chromatography proceeds with maximum speed and separating efiect. Developers containing other alcohols or ketones instead of n-butyl alcohol or see. butyl alcohol are not suitable for the process according to the invention; they produce either diffuse zones or no zones at all. By employing salts according to the invention sec. butyl alcohol-being otherwise of no use in chromatographing Biz-vitamins on cellulose columnscould be made an excellent developer. Sec. butyl alcohol has among others the advantage over n-butyl alcohol of being able to dissolve more water (up to approximately 31% by volume) than n-butyl alcohol (up to approximately 18% by.volume), whereby also Bizfactors migrating more slowly may be developed and eluted with sufficient speed (if more water is added to the developer). A narrowing and decelerating of the zones containing the Biz-vitamins is etfected-when using n-butyl-alcoholwater as well as sec.-butyl-alcohol-waterby the salts which are used according to the present invention. Both effects may probably be explained by the same cause, i. e. by the formation of complex compounds with B12- vitamins. The fact of such complex compounds being formed may be gathered from the literature. Thus perchloric acid forms-though under entirely different conditions, namely in glacial acetic acid--a compound with vitamin B12, which compound contains 6 molecules perchloric acid per 1 molecule vitamin B12 (see I. F. Alicino, I. Am. Chem. Soc. 73, 4051 (1951)). Complex compounds are formed by certain carbonyl compounds with certain strong acids (e. g. with trichloroacetic acid, dichloroacetic acid, perchloric acid, nitric acid) as well as with certain salts; certain amino-ketones form complex compounds with for instance perchloric acid (see F. Hein Chemische Koordinationslehre, S. I-lirzel-Verlag, Leipzig, 1950, pages 462467). The molecules of the various Biz-kinds charged with the respective ions respectively salts migrate differently in most cases more slowly-than in uncharged condition (decelerating effect). This retardation of the migration of the chromatographic zones has its most evident effect on the slower factors and is very insignificant with for instance etiocobalamine (see table I). Chromatography of vitamins of the Biz-group on columns of cellulose powder. Developer: Water-saturated n-butyl alcohol containing CN without respectively with an addition of potassium perchlorate. The numbers given indicate the R-values (mean values). Thereby the dispersion of the chromatograrns and, owing to this, also the separation of the individual factors is substantially improved. The intensification (narrowing) of the zones may probably be explained by the reduction of diffusion owing to the formation of complex compounds; it also contributes greatly to increase the separating efiect. The following conditions have to be fulfilled by salts increasing the dispersion in cellulose column chromatography: They are neutral (neutral pH-value of aqueous solutions), easily dissociable in water (i. e. they are derived from strong acids), their anions are monobasic and consist of at least 4 non-metal atoms. Salts not belonging to this group are not suitable. Am- monium salts, for instance, are not suited because of their acid reaction. Salts of weak acids show no effect at all, (in conformity with F. Hein, see above; according to whom only strong acids are capable of forming complex compounds). Salts of multivalent anions, such as, for instance, sulfates and phosphates are likewise unsuited; in most cases sulfates have no remarkable influence, whereas phosphates cause completely diffuse zones. Salts which cause a positive separating eifect in cellulose column chromatography also increase the efiiciency of paper chromatography. As shown in Fig. l the dispersion of the factors vitamin B12, factor III, factor A, and pseudo vitamin B12 is most substantially increased if the developer (water-saturated sec. butyl alcohol) is saturated with potassium perchlorate. Figure 2 illustrates the effect of various amounts of water in the developer on the separation. For preparing the column for instance 50 g. cellulose powder Whatman Standard Grade and 500 cc. water-saturated n-butyl alcohol, containing e. g. 0.2-0.5 cc. of an aqueous solution of hydrocyanic acid are shakenwhile gradually adding approximately 20 cc. wateruntil the material is homogeneous. The pulp is filled into the chromatographic column in small portions which are compressed each time by a perforated stamper. When employing sec. butyl alcohol as developer one proceeds in the same way but without using additional water. The compositions respectively concentrates of B12 vitamins to be chromatographed are mostly applied to the columns as dry materials, for instance in the form of a kieselguhr (diatomaceous earth) preparation, (see K. Bernhauer and W. Friedrich, Angew. Chemie 66, 776 (1954)). The dry kieselguhr preparation of Biz-vitamins is treated with hydrocyanic acid fumes and subsequently filled into the column containing above the cellulose packing a thin layer of e. g. 1-2 centimeters of the developer; it is then covered with a disk of filter paper and finally compressed by the stamper. As developer there is used water-saturated n-butyl alcohol or hydrated sec. butyl alcohol containing water and a small quantity, for instance 0.4-1.0 cc. of an aqueous solution of 10% hydrocyanic acid per liter. The water to be used for preparing the column as well as the developer should be free of carbonic acid. In general all chromatographic zones are developed in the same succession, no matter in which way the chromatography is performed. For the best known Biz-vitamins having n-butyl-alcohol-water as developer this sequence results from the following R-values: Vitamin Biz-factor: R-value Etiocobalamine 0.40-0.59 Vitamin B 2 0.21-0.29 Biz-factor III 0.08-0.12 b vitamin B12 0.055-0.08 The variation of the R-values may be explained by the diflerent quality of the cellulose powder and by contamination of the material to be chromatographed (for instance by salts) whereby the migration speed of the individual zones is eifected. EXAMPLE 1 A slurry consisting of 5 g. cellulose powder, 50 cc. water-saturated n-butanol containing CN'-ions and 2 cc. water was introduced into a chromatographic column (diameter 11.5 mm.) in small portions each of which was separately compressed in the column by means of a perforated punch. A dry concentrate of Biz-vitamins obtained from 5 l. of digested sludge in the form of a kieselguhr-preparation was treated with vapor of hydrocyanic acid, introduced into the column and after covering with a sheet of a filter paper compressed with the punch. The column was developed with water-saturated n-butanol containing CN'- ions. During this developing four colored chromatographic zones appeared on the column according to the following sheet: Vitamin Biz-factor: R-value Etiocobalamine -d 0.5 Vitamin B12 0.25 Factor III 0.10 Factor V 0.05 The fractions containing vitamin B12 and factor III were extracted with water, evaporated in vacuo to a small volume and after addition of acetone allowed to stand whereby the vitamins crystallized as red needles. EXAMPLE 2 A kieselguhr dry preparation containing various B12- vitamins was after addition of some potassium perchlorate well ground and introduced into a chromatographic colurnn according to Example 1. During the developing with water-saturated n-butanol, containing CN-ions, five chromatographic zones appeared on the column according to the following sheet: Vitamin Biz-factor: R-value Etiocobalamine 0.4 Factor Ia 02 Vitamin B12 0.12 Factor III 0.05 Factor V 0.02 EXAMPLE 3 A slurry containing 12 g. of cellulose powder, cc. of water-saturated sec. butanol and 0.24 cc. of an aqueous solution of 10% hydrocyanic acid was introduced in small portions into three chromatographic columns (diameter 11.5 mm.), each of the portions being compressed with a perforated punch. A dry kieselguhr preparation containing about 1 mg. of each of the following vitamin Biz-factors: etiocobalamine, vitamin B12, factor III and pseudo vitamin B12 was introduced into each of the columns. The first of the columns was developed with sec. butanol containing CN-ions and 31 vol.-percent water; the second column was developed with sec. butanol containing CN'- ions and 25 vol.-percent of water, the third column with sec. butanol containing CN-ions and 20 vol-percent of water. For results see Fig. 2 and Table 2. EXAMPLE 4 Three chromatographic columns prepared according to Example 3 were developed with mixtures of sec. butanol, hydrocyanic acid and water, said mixtures being saturated with potassium perchlorate. The developer of the first column contained 31 voL-percent of water, the second 25 vol-percent, the third 20 vol-percent. For results see Fig. 2 and Table 2. Table 2 Chromatographic separation of some vitamin Biz-sorts in cellulose powder-columns. Developer: CN'-ions containing sec. butanol with various content of water with ma ia; and without potassium perchlorate. Diameter of the columns 11.5 mm., height of the columns 65 mm. sec. butanol containing 23 VOL-percent of water, traces of CN-ions and 0.093% of sodium trichloroacetate. Developer vol. R-values of factors Percent Column No. K0104 Results see. I II III IV butanol water (etioco (vitamin (factor (L-vitabalamine) B12) III) min BlZ) 1 69 31 Without. only one cifiuse zone no separation. 2 75 25 do 0.67 0. 42 0.33 0.26 zones difiuse and too narrow. 3 80 20 do 0.40 0.21 0.086 0.055 I and II rather well separated, III and IV dilIuse, quantitatively not separable. 4..- 69 31 with 1.0 0.77 0.57 0. 24 III ianid IV very well separa e 5 75 25 do. 0.67 0.34 0.146 0.067 all iapitors very well separa e 6 80 do 0.38 0.15 0.058 0.027 quick factors very well separated, the others move too slow. EXAMPLE 5 During the developing appeared on the chromatographic EXAMPLE 6 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 VOL-percent of water and traces of CN'-ions and saturated with potassium chlorate. During the developing appeared on the chromatographic columns four well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.55, 0.31, 0.12, 0.07 respectively. EXAMPLE 7 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 vol.-percent of water, traces of CN-ions and 0.05% of potassium nitrate. During the developing appeared on the chromatographic column four well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.65, 0.29, 0.14, 0.09 respectively. EXAMPLE 8 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 vol.-percent of water, traces of CN-ions and 0.05% of sodium monochloroacetate. During the developing appeared on the chromatographic column four quite well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.61, 0.40, 0.17, 0.1 respectively. EXAMPLE 9 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 VOL-percent of water, traces of CN'-ions and 0.076% of sodium dichloroacetate. During the developing appeared on the chromatographic column four well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.7, 0.37, 0.14, 0.09 respectively. EXAMPLE 10 chromatographic column prepared and fitted with B z-vitamins according to Example 5 was developed with column four very well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.53, 0.32, 0.13, 0.07 respectively. EXAMPLE 11 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 VOL-percent of water, traces of CN-ions and 0.12% of sodium dibromoacetate. During the developing appeared on the chromatographic col umn four very well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.53, 0.35, 0.10, 0.06 respectively. EXAMPLE 12 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 vol.-percent of water, traces of CN-ions and 0.086% of sodium tetraphenylboron. During the developing appeared on the chromatographic column four very well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.51, 0.26, 0.12, 0.06 respectively. EXAMPLE 13 A chromatographic column prepared and fitted with B12-vitamins according to Example 5 was developed with sec. butanol containing 23 vol-percent of water, traces of CN-ions and 0.136% of sodium salt of camphosulphonic acid. During the developing appeared on the chromatographic column four very well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.42, 0.29, 0.09, 0.04 respectively. EXAMPLE 14 A chromatographic column prepared and fitted with Biz-vitamins according to Example 5 was developed with sec. butanol containing 23 VOL-percent of water, traces of CN-ions and 0.107% of sodium 2,4-dichlorobenzoate. During the developing appeared on the chromatographic column four very well separated zones of etiocobalamine, vitamin B12, factor III and factor V, the R-values of which were 0.5, 0.28, 0.073, 0.05 respectively. EXAMPLE 15 A chromatographic column prepared and fitted with Biz-vitamins according to Example 5 was developed with sec. butanol containing 23 VOL-percent of water, traces of CN'-ions and 0.115% of sodium alpha-naphthalenesulphonate. During the developing appeared on the chromatographic column four very well separated zones of etiocobalamine, vitamin B12, factor 111 and factor V, 9 the R-values of which were 0.51, 0.27, 0.11, 0.08 respectively. EXAMPLE 16 A chromatographic column prepared and fitted with Biz-vitamins according to Example 5 was developed with sec. butanol containing 23 VOL-percent of water, traces of CN-ions and 0.098% of sodium salt of sulfanilic acid. During the developing appeared on the chromatographic column four well separated zones. We claim: 1. A process for purifying and separating B12 group vitamins by means of partition chromatography, comprising the steps of preparing a pulp from a cellulose material and a straight chain butyl alcohol containing water, charging the pulp onto a chromatographic column, then charging a mixture of B12 vitamin factors onto the column, and developing the chromatogram by adding a water-containing developer comprising a straight chain butyl alcohol, thereby eluting each of the vitamin B12 factors contained in said mixture separately. 2. The process according to claim 1, characterized in that the developer contains normal butyl alcohol and has a water content up to and including 18% by volume. 3. The process according to claim 1, characterized in that the developer contains secondary butyl alcohol and has a water content up to and including 31% by volume. 4. The process according to claim 1, characterized in that said cellulose material consists of cellulose powder. 5. The process according to claim 1, characterized in that said cellulose material consists of cellulose flakes. 6. The process according to claim 1, characterized in that said developer contains CN- ions. 7. The process according to claim 1, characterized in that a kieselguhr product of the mixture of B12 vitamin factors is charged onto the column. 8. A process for purifying and separating B12 group vitamins by means of partition chromatography, comprising the steps of preparing a pulp from cellulose material and a straight chain butyl alcohol containing water, charging the pulp onto a chromatographic column, then charging a mixture of B12 vitamin factors onto the column, and developing the chromatogram by adding a Watercontaining developer comprising a straight chain butyl alcohol and at least one salt of a strong acid, which salt has monobasicanions consisting of at least four nonmetal atoms, is easily dissociable in water, and forms aqueous solutions of neutral pH. said developer serving to elute each of the vitamin B12 factors contained in said mixture separately, said salt improving the dispersion of said chromatogram. 9. The process according to claim 8, characterized in that said easily dissociable salt is a salt containing a cation selected from the group consisting of sodium and potassium, and an anion selected from the group consisting of perchlorate, tetraphenyl borate, campho sulfonate and trichloracetate. 10. The process according to claim 8, characterized in that said easily dissociable salt is potassium perchlorate. 11. The process according to claim 8, characterized in that said easily dissociable salt is the sodium salt of hydrogentetraphenylboron. 12. The process according to claim 8, characterized in that said easily dissociable salt is the sodium salt of a camphosulfonic acid. 13. The process according to claim 8, characterized in that said easily dissociable salt is the sodium salt of trichloracetic acid. 14. The process according to claim 8, characterized in that the easily dissociable salt is added to the developer before the beginning of the development of the chromatogram. 15. The process according to claim 8, characterized in that a kieselguhr product of the mixture of B12 vitamin factors is charged onto the column. 16. A process for purifying and separating B12 group vitamins by means of partition chromatography, comprising the steps of preparing a pulp from cellulose material and a straight-chain butyl alcohol containing Water, charging the pulp onto a chromatographic column, then charging a kieselguhr product of a mixture of B12 vitamin factors onto the column, and thereafter developing the chromatogram by adding a developer containing water, a straight chain butyl alcohol, and at least one easily dissociable salt having a monobasic anion consisting of at least four non-metal atoms, and a monovalent cation selected from the group consisting of sodium and potassium, thereby improving the dispersion of the chromatogram rand eluting each of the vitamin B12 factors separately from said mixture. References Cited in the file of this patent Buchanan: J. of the Chem. Soc. (1950, part III), pp. 2845-2855. Balston: Guide to Filter Paper and Cellulose Powder Chromatography (1952), pp. 14 and 23. 1. A PROCESS FOR PURIFYING AND SEPARATING B12 GROUP VITAMINS BY MEANS OF PARTITION CHROMATOGRAPHY, COMPRISING THE STEPS OF PREPARING A PULP FROM A CELLULOSE MATERIAL AND A STRAIGHT CHAIN BUTYL ALCOHOL CONTAINING WATER, CHARGING THE PULP ONTO A CHROMATOGRAPHIC COLUMN, THEN CHARGING A MIXTURE OF B12 VITAMIN FACTORS ONTO THE COLUMN, AND DEVELOPING THE CHROMATOGRAM BY ADDING A WATER-CONTAINING DEVELOPER COMPRISING A STRAIGHT CHAIN BUTYL ALCOHOL, THEREBY ELUTING EACH OF THE VITAMIN B12 FACTORS CONTAINED IN SAID MIXTURE SEPARATELY. 16. A PROCESS FOR PURIFYING AND SEPARATING B12 GROUP VITAMINS BY MEANS OF PARTITION CHROMATOGRAPHY, COMPRISING THE STEPS OF PREPARING A PULP FROM CELLULOSE MATERIAL AND A STRAIGHT-CHAIN BUTYL ALCOHOL CONTAINING WATER, CHARGING THE PULP ONTO A CHROMATOGRAPHIC COLUMN, THEN CHARGING A KIESELGUHR PRODUCT OF A MIXTURE OF B12 VITAMIN FACTORS ONTO THE COLUMN, AND THEREAFTER DEVELOPING THE CHROMATOGRAM BY ADDING A DEVELOPER CONTAINING WATER, A STRAIGHT CHAIN BUTYL ALCOHOL, AND AT LEAST ONE EASILY DISSOCIABLE SALT HAVING A MONOBASIC ANION CONSISTING OF AT LEAST FOUR NON-METAL ATOMS, AND A MONOVALENT CATION SELECTED FROM THE GROUP CONSISTING OF SODIUM AND POTASSIUM, THEREBY IMPROVING THE DISPERSION OF THE CHROMATOGRAM AND ELUTING EACH OF THE VITAMIN B12 FACTORS SEPARATELY FROM SAID MIXTURE.

1954-12-07

en

1957-10-08

US-92060497-A

Integrated DRAM with high speed interleaving ABSTRACT An integrated circuit includes a controller and a memory to implement a graphics controller. The controller and memory are controlled by a common clock signal to operate synchronously with each other. The memory is organized in a plurality of storage arrays, organized in two banks. A set of bit-line sense amplifiers is provided for each bank. A pair of row decoders decode a row address to select a row of data from each bank. The selected row of data is received by a pair of bit-line sense amplifiers. A column decoder selects a column of data from the pair of bit-line sense amplifiers. A pair of multiplexers select one-half of the selected column in response to a HI/LO signal and then select the remaining half of the selected data in response to a change in value of the HI/LO signal. Main or data sense amplifiers amplify the output of the multiplexers to provide data outputs in the form of full swing signals. FIELD OF THE INVENTION This invention relates generally to the field of digital memory systems. BACKGROUND OF THE INVENTION High performance data processing systems require digital memory systems which are capable of storing and providing large amounts of data at very high speeds. For example, graphics controllers which operate in conjunction with a host computer to perform sophisticated image manipulation and rendering functions to generate data for display on a display screen, require memories which are capable of storing and providing the amount of data required of such functions at very high data rates. Dynamic Random Access Memories (DRAMs) are often used to meet the storage requirements required by high performance systems. DRAMs are typically characterized by a greater storage density per chip when compared to static random access memories (SRAMs). However, DRAMs are also typically characterized by slower access times then SRAMs. A variety of techniques have been used to increase the bandwidth of digital memory systems employing DRAMs. For example, the memory, and the data paths to and from the memory, may be organized to allow multiple words of data to be retrieved in a single access. Although such a technique provides increased bandwidth, there remains a need for digital memory systems which provide even greater data storage and data throughput than is currently available. SUMMARY OF THE INVENTION In a principal aspect, embodiments of the present invention provide a memory system capable of providing data at high rates. Presentation of a row address to the memory system results in a row of data being read out of parallel storage arrarys in the memory system by a plurality of Bit-Line Sense Amplifiers (BLSA). Presentation of a column address to the memory system causes selection of a corresponding column of data in the selected row. The selected column of data is retrieved in two phases by toggling of the least significant bit of the column address. Advantageously, the signals in the memory system are of the small signal differential type of signal produced by the BLSAs, and are not amplified by main sense amplifiers (MSA) until selection of each of the subsets or phases for output. This advantageous feature allows a reduction in the number of MSAs required for the memory system. The result is fewer hardware elements, fewer routing lines to connect such components and lower power consumption. A further advantage is that output of the selected column in two subsets or phases results in higher data throughput by allowing the least significant column address bit to be switched at a rate approximately twice as fast as the column address. This feature provides the advantage of allowing simple and more direct routing of the single, least significant bit of the column address for higher speed switching. The lower frequency switching required of the column address imposes fewer constraints on the routing of the column address signals in the IC chip, thus reducing design complexity. These and other features and advantages of the present invention may be better understood by considering the following detailed description of a preferred embodiment of the invention. In the course of this description, reference will frequently be made to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a high-level block diagram of a graphics controller chip which employs the principles of the present invention. FIG. 2 is a block diagram of a preferred embodiment of the memory system of FIG. 1. FIG. 3 is a timing diagram showing operation of a preferred embodiment. DETAILED DESCRIPTION In FIG. 1 of the drawings, a graphics controller is implemented in an Integrated Circuit (IC) 100 which includes a controller 102 and a memory 104. The graphics controller preferably operates in conjunction with a microprocessor (not shown) to receive data and commands from the microprocessor, to store data in the memory 104, to manipulate the data via the controller 102 and to display the data onto a visual display (not shown) by generation of appropriate control signals. An example of the functions performed by the controller is provided in a data book published by S3 Incorporated of Santa Clara, Calif., entitled ViRGE Integrated 3D Accelerator, published August 1996. This data book describes many of the functions performed by the ViRGE graphics accelerator chip sold by S3 Incorporated. Memory 104 preferably takes the form of a Dynamic Random Access Memory (DRAM). In a preferred embodiment, the controller 102 and the memory 104 are coupled by a data path which is 128 bits wide allowing transfers between the controller and the memory of 128 bits per clock cycle. The memory 104 stores and outputs data in response to control signals generated by the controller 102. FIG. 2 of the drawings is a block diagram illustrating further details of the memory 104. The memory 104 includes a plurality of storage arrays 202, 203, 204, 205, 206, 207, 208 and 209 which are alike in structure and storage capacity. The storage arrays 202-209 are organized in two banks 211 and 212 which may be referred to as an odd bank and an even bank, respectively. The storage arrays are conventional DRAM type storage arrays which employ a one transistor-one capacitor per cell structure to achieve high density. In a preferred embodiment, each of the storage arrays 202-209 contains 256 rows each containing 1 K bits. Thus, each bank 211, 212 stores 256×1k×4=1M bit of data, for a total memory capacity between the two banks of 2M bits. The data stored in the storage arrays is accessed by decoding a row address with decoder 214. In a preferred embodiment the row address is 8 bits to correspond to 256 rows in the banks 211 and 212. The row address is stored in a register 213 in response to a Row Address Strobe (RAS) signal generated by controller 102. The decoder 214 selects one of 256 rows in the storage arrays 202-209 to be read out by two sets of bit-line sense amplifiers (BLSA) 216 and 218. The row address decoded by decoder 214 is supplied to each array of each bank to generate a row of data which is 8k bits wide. BLSA 216 senses and amplifies the data stored in the storage cells contained in the odd half 211 of the row selected by row decoder 214. BLSA 218 operates similarly with even half of the row selected in bank 212. A column address received from controller 102 is stored in register 219, in response to a Column Address Strobe (CAS) signal from controller 102. The column address in register 219 is decoded by a decoder 220 to select 256 bits from the 8k bits stored in BLSA 216 and 218. Multiplexers 220 and 222 perform a two-to-one multiplexing function. Multiplexer 220 receives 128 bits from BLSA 216 into 64 pairs of two-to-one multiplexers. Multiplexer 222 is similarly organized and operates in a similar manner with respect to BLSA 218. Multiplexers 220 and 222 are both controlled by a HI/LO signal generated by the controller 102. The HI/LO signal corresponds to the least significant bit of the column address. Once BLSAs 216 and 218 have sensed and amplified the data in each of the storage cells of the selected row, 128 bits of data representing a half column of data are available to the controller 102 from the memory 104. As can be seen from FIG. 2, each 128 bit quantity of data provided by memory 104 consists of 64 bits of data from odd bank 211 and 64 bits of data from even bank 212. Once the controller 102 has captured the first 128 bits of data, the HI/LO signal is toggled to change its value from a binary 0 to a binary 1, or alternatively from a binary 1 to a binary 0, to cause multiplexers 220 and 222 to select the other 64 bits of data received from BLSAs 216 and 218, respectively. As can be seen, toggling of the HI/LO signal causes another 128 bits of data to be outputted by the memory 104. Use of the HI/LO signal to retrieve an additional 128 bits of information is advantageous in that only one signal needs to be toggled to generate an additional 128 bits of data instead of changing of an entire address bus. This simplifies routing of the IC chip 100 by allowing the single HI/LO signal to be designated as a critical path and to be routed on the IC chip 100 in an optimal manner to allow for higher frequency switching, than would be possible for the row address lines or the column address lines. Data selected by multiplexers 220 and 222 is amplified by an odd and even set of Main Sense Amplifiers (MSA) 224 and 226. The MSAs 224 and 226 are conventional and are also commonly known as data sense amplifiers. The MSAs 224 and 226 operate in a conventional fashion to convert the small (differential) type signal generated by BLSA's 216 and 218 into full swing signals useable by the controller 102. The foregoing description has focused on a read operation in which data is retrieved from the memory 104. A write operation operates similarly in all respects except that a write enable signal is generated by controller 102 and data is provided to the memory 104 for writing into the storage arrays. The MSA's 224 and 226 convert the received full swing data signals into small signals. The resulting signals are then written into the appropriate location in banks 211 and 212 in response to appropriate row and column addresses, RAS and CAS signals and the write enable signal. In FIG. 2 the write enable signal is shown generally. Control of the memory system including the data paths internal to the system to distinguish between read and write operations is conventional and will be understood by those skilled in the art in view of the present disclosure. FIG. 3 of the drawings is a timing diagram showing the relationship of the signals sent by controller 102 to memory 104 to obtain four data words. The data, address and control signals generated by the controller 102 are generated synchronously with a clock signal designated in FIG. 3 as CLK, and shown at 302. A Write Enable (WE) signal shown at 304 controls whether a memory operation is for reading or for writing. The Write Enable signal is shown as an active low signal, meaning that when it has a logical 0 value, it controls the writing of data into the memory 104, and when it has a logical 1 value, it is inactive and data is then read from memory. The row address to the memory is shown at 306 and as explained above, preferably comprises 8 bits to select one of 256 rows. Use of the row address 306 by the memory 104 is controlled by the RAS signal 305 which causes the row address to be stored into register 213. The column address signal as noted above preferably comprises 6 bits and is shown at 308. Use of the column address is controlled by the CAS signal shown at 307, which causes the column address to be stored in register 219. The HI/LO signal is shown at 310. Data outputted by the memory 104 is shown at 312. The timing diagram of FIG. 3 shows a read operation. The read operation takes eight clock cycles as shown by the individually numbered clock signals at 302. In the cycle before cycle 0, a row address is placed onto the row address bus by the controller 102 and the RAS signal is asserted to store the row address into the register 213. In clock cycle 2, after a sufficient amount of time has been allowed for the row address to be decoded and to allow the data in the decoded row to be sensed into the sense amplifiers 216 and 218, the column address is provided to select one of the two columns in the selected row and the CAS signal 307 is asserted to cause the column address to be stored. The CAS signal as seen is asserted at cycle 2. At cycle 4, the first 128 bits of data becomes available in the selected row. At cycle 3, the HI/LO signal is toggled to cause the second 128 bits of data to become available at cycle 5. Also at cycle 5, the column address is changed to select the second column of data stored in the sense amplifiers 216 and 218. This causes a third 128 bits of data to become available at cycle 6, during which cycle the HI/LO signal is toggled once again to cause a fourth 128 bits of data to become available in cycle 7. The second column address may be but need not be sequential to the first address. Once the second column address has been asserted at cycle 5, in the following cycle RAS and CAS are deactivated as they are no longer needed. This allows another memory cycle to start at cycle 9. As seen from the timing diagram of FIG. 3, a total of 512 bits of data are accessed by using the single row address. The HI/LO signal is toggled at a frequency which is twice the frequency at which the column address is required to change. This reduces the number of critical paths required in the memory 104 and allows the frequency of the clock to be increased in comparison to using four different column addresses to retrieve the same amount of data. It is to be understood that the specific mechanisms and techniques which have been described are merely illustrative of one application of the principles of the invention. For instance, the specific widths of data paths and the size of the memory arrays described herein are provided merely to assist in explanation of an exemplary embodiment. Other widths and sizes are well within the scope of the principles of the invention. Numerous additional modifications may be made to the methods and apparatus described without departing from the true spirit and scope of the invention. What is claimed is: 1. An integrated circuit comprising:a graphics controller which generates a row address signal, first and second column address signals for each row signal and which switches a hi/lo signal for each column address signal, to read a plurality of data words from a memory; said memory comprising a Dynamic Random Access Memory (DRAM) which comprises, a plurality of arrays, organized into an odd bank and an even bank, each array including a plurality of rows and a plurality of columns; a pair of bit-line sense amplifiers, a first of said bit-line sense amplifiers corresponding to said odd bank and a second of said bit-line sense amplifiers corresponding to said even bank; a row decoder which selects one of said rows in accordance with said row address received from said graphics controller, to transfer bits in a selected row to said first and said second bit-line sense amplifiers; a column decoder which selects a pair of columns in said selected row in accordance with said first and said second column address received from said graphics controller; and a pair of multiplexers, a first of said multiplexers coupled to receive data from said first bit-line sense amplifier and a second of said multiplexers coupled to receive data from said second bit-line sense amplifier, said multiplexers responsive to said hi/lo signal generated by said graphics controller to select a first subset of bits stored in each of said bit-line sense amplifiers to generate a first data output word from said first column address in response to a first state of said hi/lo signal, and responsive to a change in value of said hi/lo signal for selecting a second subset of bits stored in each of said bit-line sense amplifiers to generate a second data output word from said first column address. 2. An integrated circuit as set forth in claim 1 wherein the memory generates a third and a fourth data output word from said row address in response to said second column address and a change in value of said hi/lo signal. 3. An integrated circuit as set forth in claim 2 wherein each of said data words consists of 128 bits. 4. A memory system comprising:a plurality of memory arrays, each of said arrays comprising a plurality of rows, and a plurality of columns, each of said columns comprising a plurality of multi-bit memory words; a row address decoder responsive to a row address for selecting one of said plurality of rows; a column address decoder responsive to a column address for selecting one of said plurality of columns; a pair of sense amplifiers responsive to said selected row for storing data contained in said row; a selector which responds to a first value of a hi/lo signal to select a first sub-group of data, corresponding to said column address, stored in each of said bit-line sense amplifiers and to a second value of said hi/lo signal to select a second sub-group of data, corresponding to said column address, stored in each of said bit-line sense amplifiers, said first and said second sub-groups of data comprising small signal differential type signals. 5. A memory system comprising:an odd memory bank and an even memory bank each of said banks comprised of at least one memory array arranged in a plurality of rows and columns; a row address decoder which responds to a row address to select one of said rows of said odd and even memory banks; an odd bit-line sense amplifier responsive to data bits in said selected row in said odd memory bank and an even bit-line sense amplifier responsive to data bits in said selected row in said even memory bank; a column address decoder which responds to a column address to select a column of data bits from said odd bit-line sense amplifier and said even bit-line sense amplifier; and an odd set of multiplexers, responsive to a HI/LO signal, which selects a first subset of said column of data bits selected from said odd bit-line sense amplifier; and an even set of multiplexers, responsive to said HI/LO signal, which selects a second subset of said column of data bits selected from said even bit-line sense amplifier. 6. A memory system as set forth in claim 5 further comprising:a set of odd data sense amplifiers which amplify signals selected by said odd set of multiplexers; and a set of even data sense amplifiers which amplify signals selected by said even set of multiplexers; said odd data sense amplifiers and said even data sense amplifiers receiving small signal differential type signals and generating data outputs for said memory system in the form of full swing data signals. 7. A memory system as set forth in claim 5 wherein said odd memory bank and said even memory bank each comprise four sets of memory arrays. 8. A memory system as set forth in claim 5 wherein said memory system responds to a change in value of said HI/LO signal by providing the remainder of data selected by said column address decoder. 9. An integrated circuit comprising:a graphics controller which generates a row address signal, a column address signal and which switches a hi/lo signal corresponding to said column address signal, to read a plurality of data words from a memory; said memory comprising a Dynamic Random Access Memory (DRAM) which comprises, an odd memory bank and an even memory bank each of said banks comprised of at least one memory array arranged in a plurality of rows and columns; a row address decoder which responds to a row address to select one of said rows of said odd and even memory banks; an odd bit-line sense amplifier responsive to data bits in said selected row in said odd memory bank and an even bit-line sense amplifier responsive to data bits in said selected row in said even memory bank; a column address decoder which responds to said column address to select a column of data bits from said odd bit-line sense amplifier and said even bit-line sense amplifier; and an odd set of multiplexers, responsive to said hi/lo signal, which selects a first subset of said column of data bits selected from said odd bit-line sense amplifier; and an even set of multiplexers, responsive to said hi/lo signal, which selects a second subset of said column of data bits selected from said even bit-line sense amplifier. 10. An integrated circuit as set forth in claim 9 wherein said memory system further comprises:a set of odd data sense amplifiers which amplify signals selected by said odd set of multiplexers; and a set of even data sense amplifiers which amplify signals selected by said even set of multiplexers; said odd data sense amplifiers and said even data sense amplifiers amplifiers receiving small signal differential type signals and generating data outputs for said memory system in the form of full swing data signals. 11. A memory system as set forth in claim 10 wherein said odd memory bank and said even memory bank each comprise four sets of memory arrays. 12. A memory system as set forth in claim 11 wherein said memory system responds to a change in value of said hi/lo signal by providing the remainder of data selected by said column address decoder. 13. An integrated circuit as set forth in claim 1 wherein said first and said second data output words generated by said pair of multiplexers are small signal differential type signals. 14. A memory system as set forth in claim 5 wherein said first subset of said column of data bits selected from said odd bit-line sense amplifier and said second subset of said column of data bits selected from said even bit-line sense amplifier are small signal differential type signals. 15. A memory system as set forth in claim 6 wherein said odd data sense amplifiers and said even data sense amplifiers receive small signal differential type signals. 16. A memory system as set forth in claim 8 wherein said data selected by said column address decoder are small signal differential type signals. 17. An integrated circuit as set forth in claim 9 wherein said data words read by said graphics controller are full swing type signals and wherein said data bits selected by said column address decoder are small signal differential type signals. 18. An integrated circuit as set forth in claim 9 wherein said data words read by said graphics controller are full swing type signals and wherein said data bits generated by said odd and said even bit-line sense amplifiers are small signal differential type signals and wherein said data bits selected by said column address decoder are small signal differential type signals.

1997-08-27

en

1999-01-05

US-91245497-A

Interface conversion modules based upon generalized templates for multiple platform computer systems ABSTRACT A utility program develops and updates an API-translation layer of an emulator for running programs written for one platform on another platform. This speeds the development of code such as operating-systems upgrades, where the API set can change frequently. The utility builds a module for each API from a set of templates to execute the module&#39;s function on the other platform. Generalized function templates iterate through API functions. Exception templates can override the generalized templates in specific cases. Types templates convert individual arguments of the API. Code templates contain code for incorporation into a number of other templates. FIELD OF THE INVENTION The present invention relates to electronic data processing, and more specifically concerns a software tool for generating a set of translation-code modules for translating application-program interfaces (APIs) from one platform to another, for use with an emulator which allows application programs written for one platform to be executed on a different platform. BACKGROUND OF THE INVENTION Present-day application programs almost never interface directly to the hardware of the computer system in which they execute. Instead, application program interfaces (APIs) call code modules which control the hardware, or which call programmed interfaces at yet lower levels. Most API code modules reside in an operating system (OS), although others may exist in a basic input/output system (BIOS), or in other places. Code modules for API functions typically reside in freestanding dynamic link library (DLL) files each containing routines for carrying out dozens or even hundreds of API functions. Executing an application program written for one computer processor, operating system, or other platform on another platform requires a program, variously known as an emulator, simulator, interpreter, or translator, to convert instructions, data formats, application-program interfaces (APIs), and other characteristics of the application from those of its original platform to those of the native platform in which the emulator runs. Sometimes the original platform has been replaced, but the old application must still be run on the new platform. Sometimes programs are written to an abstract platform, so that the same application can be executed on numerous different platforms merely by writing an emulator for each native platform that is to host the abstract platform. An emulator subsystem generally has two major components. The emulator itself converts the original processor instructions from the application into instructions or groups of instructions appropriate to the processor of the new platform, and executes them. An API translation layer "thunks" API calls from the original platform being emulated into calls to APIs written for the native platform; that is, it intercepts API calls made by an application written for the emulated platform, converts their arguments from the calling convention of the original platform to that of the native platform, then calls an appropriate native-platform module for executing the API function. A translation module or "API thunk" is a piece of program code in the translation layer which executes between a particular original API and the operating system running on the native platform. Conventional practice involves hand-writing thunk code for each new and modified API. However, an API set may change daily during the development of an operating system. Also, the number of APIs can be very large. The Microsoft Windows NT operating system, for example, contains more than 3,500 APIs in 42 different DLL modules. Therefore, manual production of individual API translation code becomes increasingly impractical. Increasingly shorter product cycles compounds this problem. Some interface modules or thunks have been generated from handwritten descriptors for each separate API. However, these must be maintained separately from the APIs themselves, and thus involve costly additional effort. They also suffer from "synchronization" problems: if one or more modules inadvertently escape an update between one development iteration and the next, their down-level code may mistranslate an API, or may crash the system. Such problems can be difficult to find, thus forcing the entire development effort to wait. Alternatively, a software tool has been employed to create a set of skeleton API thunks as C-language source files which were then hand-modified. This approach is impractical, in that rerunning the tool destroys all the hand edits. SUMMARY OF THE INVENTION A utility program according to the present invention creates and automatically updates code modules for translating APIs written for one platform so that they will execute properly on a different platform. The utility, executed for every new development iteration of an operating system or other software environment, uses a set of templates for constructing source code for the translation modules, based upon the functions performed by the APIs. Special translation requirements are handled by exception templates containing personalized translation code. Another kind of template performs type conversions from the original API's parameters or arguments into those of the different platform. Automatic code generation in this manner enables much faster development iterations by providing an automated method of synchronizing the translation modules with changes made to the new operating system or environment. The code generator ensures that all translation modules are at the current updated level, which prevents system crashes caused by incompatible modules. It also greatly reduces errors within individual code modules resulting from prior hand generation methods, and eliminates errors across module caused from different people working independently on different modules. Other features and advantages, as well as modifications and additions within the scope of the invention, will appear to those skilled in the art from the following description. DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a computer system in which the invention may be practiced. FIG. 2 is a high-level block diagram of a multiple-platform emulation environment in which the invention finds utility. FIG. 3 is a high-level block diagram of a translator utility according to the invention, along with its inputs and outputs. FIG. 4 is a flow diagram showing the operation of the translator of FIG. 3. DETAILED DESCRIPTION FIG. 1 provides a brief, general description of a suitable computing environment in which the invention may be implemented. Hardware and software environments will first be discussed, followed by a detailed description of the invention comprising a tool for creating and automatically updating code modules for translating APIs written for one platform so that they will execute properly on a different platform. The invention will hereinafter be described in the general context of computer-executable instructions such as program modules, executed by a personal computer (PC); however, other environments are possible. Program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Those skilled in the art will appreciate that the invention may be practiced with other computer-system configurations, including hand-held devices, multiprocessor systems, microprocessor-based programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. FIG. 1 shows an exemplary system for implementing the invention. It employs a general-purpose computing device in the form of a conventional personal computer 20, which includes processing unit 21, system memory 22, and system bus 23 that couples the system memory and other system components to processing unit 21. System bus 23 may be any of several types, including a memory bus or memory controller, a peripheral bus, and a local bus, and may use any of a variety of bus structures. System memory 22 includes read-only memory (ROM) 24 and random-access memory (RAM) 25. A basic input/output system (BIOS) 26, stored in ROM 24, contains the basic routines that transfer information between components of personal computer 20. BIOS 24 also contains start-up routines for the system. Personal computer 20 further includes hard disk drive 27 for reading from and writing to a hard disk (not shown), magnetic disk drive 28 for reading from and writing to a removable magnetic disk 29, and optical disk drive 30 for reading from and writing to a removable optical disk 31 such as a CD-ROM or other optical medium. Hard disk drive 27, magnetic disk drive 28, and optical disk drive 30 are connected to system bus 23 by a hard-disk drive interface 32, a magnetic-disk drive interface 33, and an optical-drive interface 34, respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for personal computer 20. Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 29 and a removable optical disk 31, those skilled in the art will appreciate that other types of computer-readable media which can store data accessible by a computer may also be used in the exemplary operating environment. Such media may include magnetic cassettes, flash-memory cards, digital versatile disks, Bernoulli cartridges, RAMs, ROMs, and the like. Program modules may be stored on the hard disk, magnetic disk 29, optical disk 31, ROM 24 and RAM 25. Program modules may include operating system 35, one or more application programs 36, other program modules 37, and program data 38. A user may enter commands and information into personal computer 20 through input devices such as a keyboard 40 and a pointing device 42. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 21 through a serial-port interface 46 coupled to system bus 23; but they may be connected through other interfaces not shown in FIG. 1, such as a parallel port, a game port, or a universal serial bus (USB). A monitor 47 or other display device also connects to system bus 23 via an interface such as a video adapter 48. In addition to the monitor, personal computers typically include other peripheral output devices (not shown) such as speakers and printers. Personal computer 20 may operate in a networked environment using logical connections to one or more remote computers such as remote computer 49. Remote computer 49 may be another personal computer, a server, a router, a network PC, a peer device, or other common network node. It typically includes many or all of the components described above in connection with personal computer 20; however, only a storage device 50 is illustrated in FIG. 1. The logical connections depicted in FIG. 1 include local-area network (LAN) 51 and a wide-area network (WAN) 52. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. When placed in a LAN networking environment, PC 20 connects to local network 51 through a network interface or adapter 53. When used in a WAN networking environment such as the Internet, PC 20 typically includes modem 54 or other means for establishing communications over network 52. Modem 54 may be internal or external to PC 20, and connects to system bus 23 via serial-port interface 46. In a networked environment, program modules depicted as residing within 20 or portions thereof may be stored in remote storage device 50. Of course, the network connections shown are illustrative, and other means of establishing a communications link between the computers may be substituted. FIG. 2 shows a software environment 200 for running an application program 210 for one platform on a processor 220 representing a different platform. The elements enclosed in dashed line 201 are elements designed to be executed on a first platform such as a processor 21, FIG. 1, of the Intel "X86" family, for example, an Intel 80386, 80486, or Pentium microprocessor. The other elements execute on a second platform, such as a Digital Equipment Corp. "Alpha" or an IBM "PowerPC" microprocessor serving as processor 21. This description refers to the first and second platforms as the "X86" and "native" platforms, respectively. For purposes of illustration, a native-platform version 230 of the Microsoft NT operating system serves as OS 35, FIG. 1. Conventional emulator program 240 translates the instructions, data, and interfaces (APIs) of an X86-platform application program such as 36, FIGS. 1 and 2, from those of the X86 platforms to equivalent operations in the native platform. The APIs of an application program are actually calls to a set 250 of API modules 251-253, only a very few of which are shown in FIG. 2. API modules are commonly grouped into dynamic link libraries such as 254. As noted previously, OS 230 has thousands of APIs in more than 40 DLLs; this set, collectively known as "Win32" is recompiled into a new "build" almost daily during a development effort. When application 210 calls an API written for the X86 platform, such as API 251, a conventional API translation layer 241 in emulator 240 retrieves the proper API module 251, and calls an associated translation-code module, or "thunk," 261 to convert any API arguments and data to the correct format for the native platform, and to perform functions which emulate those the API would have performed on the original X86 platform. The set of thunks 260 includes a separate module 261-262 for each X86 API 251-252. APIs such as 253 written for the native platform execute directly when called from OS 230, and do not require thunks. FIG. 3 is a high-level block diagram 300 showing a translator utility according to the invention, along with its inputs and outputs. Some of the elements shown in FIG. 2 have different labels in FIG. 3, to denote that the corresponding elements are in compiled object-code form in FIG. 2, but exist as source-code files in FIG. 3. In its source-code form, each DLL 254, FIG. 2, is a collection 310 of files 311 each containing instructions in a language such as C for an API 250, FIG. 2. Each file represents one or more functions 312 to be performed by one of the APIs 251-252. A module-definition file (.DEF) file 322 specifies the list of functions which are to be exported from DLL 320 as APIs. The .DEF file is compiled into an import library (.LIB) file 321. The .LIB file is significant because the API name exported from the DLL may differ from the function name in source file 311; for example, an entry FOO=BAR@4 in a .DEF file instructs the linker to export the function known internally as FOO from the DLL as BAR. Thunk generator 330 uses .LIB file 321 to associate an internal function name with an exported API name. C-language files have associated header (.H) files 313 that specify the external interface of their code file 311, such as data types and external variable names. In particular, header files include type information 315 for functions 312 in code files 311. For example, a .H header file could contain a type definition such as: ______________________________________ Typedef struct tagFoo { int member1; int member2; } *PFOO and a function declaration: int AnApi {PFOO arg1, char *} ; Generator 330 stores this information for all APIs. The entries for the above example might be: TYPENAME struct tagFoo MEMBER LIST MEMBER NAME member 1 MEMBER TYPE int MEMBER OFFSET 0 MEMBER NAME member 2 MEMBER TYPE int MEMBER OFFSET 4 TYPENAME PFOO INDIRECTION 1 BASETYPE struct tagFoo APINAME AnApi RETURN TYPE int ARG NAME arg1 ARG TYPE PFOO ARG NAME <noname> ARG TYPE char * ______________________________________ Finally, a conventional definitions (.DEF) file 322 may instruct a conventional linker (not shown) in OS 230 to export an internal API name from DLL 320 as a different name. Translation generator 330 uses information from files 311, 313, and 321 to build C-language source-code files 340 which can be compiled into the translation-code modules 260 in FIG. 2. The invention provides a novel set of template files 350 for this purpose. Template (.TPL) files are descriptions of how to generate translation-code modules ("thunks"). They comprise small amounts of hand-generated C code which implement generalized forms for iterating over API functions and their arguments, and for handling special cases which may arise in particular APIs. Each template has the following syntax: ______________________________________ [Type.sub.-- of.sub.-- Template] TemplateName=Name.sub.-- Of.sub.-- Template CGenBegin= <code to generate when this template is expanded> CGenEnd= ______________________________________ There are four types of template 350. The iterated-function (IFunc) template 351 iterates over API functions. Generator 330 expands one of these for each exported function in an API. The IFunc template 351 is the default expansion for APIs. The following example template will generate a skeleton thunk 340. ______________________________________ [IFunc] TemplateName=HostFuncs CGenBegin= void wh@ApiName (PULONG BaseArgs, ULONG RetVal) @ApiFnRet *pRetVal = (@ApiFnRet *) RetVal; @Types (Locals) @Types (Body) @IfApiRet (*pRetval = ) @ApiName (@IfArgs (@ArgList (*((@ArgType *) (@ArgAddr (BaseArgs))) @ArgMore(,)))); @Types (Return) } CGenEnd= ______________________________________ Generator 330 expands each of the `@` prefixed keywords in template 351 from the data collected from files 313 and 321 for a particular API 310 as follows: ______________________________________ @ApiName Internal name of the API @ApiFnRet Return type of the API @Types(x) Expands Type templates of the form `x` @IfApiRet(x) Expands `x` if the return type of the API is non-void @IfArgs(x) Expands `x` if the API has arguments @ArgList(x) Iterates over all arguments, expanding `x` for each argument @ArgType Type of argument @ArgAddr(x) Address of the argument, relative to `x` @ArgMore(x) Expands if there are more arguments after the current ______________________________________ one For example, an API with prototype `HWND FindWindowA(LPSTR 1pClass, LPSTR 1pWindow)` expands to: ______________________________________ whFindWindowA (PULONG pBaseArgs, ULONG RetVal) HWND *pRetVal = (HWND *) RetVal; *pRetVal = FindwindowA( *(LPSTR *) (pBaseArgs+0), * (LPSTR *) (pBaseArgs+1) ); } ______________________________________ An exception-function (EFunc) template 352 recognizes a particular API name, and overrides the default IFunc template 351 for that API. The following example template 352 produces fixed code for the particular API named `SetErrorMode`. __________________________________________________________________________ [EFunc] TemplateName=SetErrorMode CGenBegin= void wh@ApiName (PULONG BaseArgs, ULONG RetVal) @ApiFnRet *pRetVal = (@ApiFnRet *) RetVal; *pRetVal = SetErrorMode ((*(UINT *) pBaseArgs) | SEM.sub.-- NOALIGNMENTFAULTEXCEPT) *pRetVal &= ˜SEM.sub.-- NOALIGNMENTFAULTEXCEPT; } CGenEnd= __________________________________________________________________________ EFunc templates provide a facility for custom-writing code for an API, while preserving robustness against API changes. Of course, the code for such an API can always be rewritten merely by rewriting its EFunc template. A types (Types) template 353 creates a thunk 340 for each parameter, or argument, of each API file 311 which matches a specified type name. Types templates are powerful in that generator 330 applies them automatically to new APIs, providing correct thunking without manual intervention. Consider the following examples: ______________________________________ [Types] TemplateName=Locals TypeName=LPSTR IndLevel=0 CGenBegin= @ArgLocal = * ((@ArgType *) (pBaseArgs + @ArgOff)); CGenEnd= [Types] TemplateName=Body TypeName=LPSTR IndLevel=0 CGenBegin= VALIDATE.sub.-- LPSTR (@ArgNameLocal); CGenEnd= ______________________________________ With these two templates, any API 311 which takes the C-language LPSTR data type automatically receives the special-purpose Types code in addition to the IFunc code for the default IFunc template. For example, the `FindWindowA` API described above now expands to: ______________________________________ HWND *pRetVal = (HWND *) RetVal; LPSTR 1pClass = *((LPSTR *) (pBaseArgs + 0); LPSTR 1pWindow = *((LPSTR *) (pBaseArgs + 1); VALIDATE.sub.-- LPSTR (1pClass); VALIDATE.sub.-- LPSTR (1pWindow); *pRetVal = FindWindowA ( 1pClass, 1pWindow ); } ______________________________________ A code template 354 operates like a macro. It contains code which may be common to a number of other templates, and is referred to by name in those templates. For example, if the line ______________________________________ *pRetVal = SetErrorMode ((* (UINT *) pBaseArgs) * ______________________________________ occurs many times in many different templates 351, 352, or 353, then that line could be placed in a code template such as one named, "serrm." The referring templates, such as the example above, then merely replace that line with the name of the macro, for example, "[@serrm]". The conventional C macro facility then replaces the name with the code; C macros can, of course, be much more complex than this simple example. Although the above templates are shown as written in the C language, they are language-independent. Templates 350 may generate code in C++, in assembler language, or in any other desired form. FIG. 4 describes the steps 400 carried out by translation-code generator 330, FIG. 3. The generator is run at 401 for every build of the operating system 230 or other entity whose APIs require regeneration. At its conclusion 402, the entire set of API translation-module source-code files 340 has been synchronized at the same level, and can be compiled in a conventional manner into the set of object-code modules 260, FIG. 2 which together form an API-translation portion (the "thunk layer") of emulator 240. Block 410 scans all the DLLs 254 belonging to the OS 230 to identify the set of APIs (261, 262, . . . in FIG. 2) which require regeneration. The names of these APIs are in the export table 314 and in the import .LIB file 321 of each DLL, as previously described. (As a technical aside, the raw exports come from the import .LIB. However, many of them may be unnamed ordinals or renamed C functions. In order to obtain type information, generator 330 must reconstruct the name of the original function that implements each API. Thus, it must sometimes unmap the export name back to the function name.) Step 403 then sequentially selects a current API in the set for processing. Step 420 may identify the current API as having an exception template 352, by a conventional table-lookup in a list of the exception-template names. If such a template exists, step 421 accesses the associated EFunc template, and step 422 places its source code into a thunk file 340 for that API. If the current API is a normal API, step 430 reads export table 314 of its header file 313 to extract the names of all its exported functions. Step expands the IFunc template 351 for those functions, as described above. When step 431 has iterated through all the exported functions of the current API, exit 432 progresses to the next step. Step 440 cycles through the parameters (arguments) of the current API, sequentially selecting one as a current parameter. If step 441 determines that a Types template 353 exists for this parameter type, then step 442 places the template's source code in the module 340, so that the API will process that argument type correctly. Most types templates substitute a different value for a parameter. However, a types template may perform other functions, such as validating the range of a parameter. Control passes to exit 443 when all Types templates have been processed. Step 450 processes Code templates 354, FIG. 3. Whenever the name of a code template appears (as a macro name) in template-processing step 422, 432, or 442, dashed lines 451 call step 450 to expand a particular named code template and return the code to the calling template. Step 450 may actually occur later, when the thunk source-code files 340 are conventionally compiled into object-code modules 260. It is to be understood that the above description is intended to be illustrative, and not restrictive. The invention may be used to provide for execution of interfaces from multiple prior platforms as opposed to just one. Further, template matching can be done in many different manners, such as by having a field in an interface which directly identifies a desired template. Many other embodiments will be apparent to those skilled in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. What is claimed is: 1. In a programmable digital computer, a method for generating a synchronized set of translation modules each containing program code representing a translated version of an interface module on a native platform, the method comprising:identifying the set of interface modules written for the emulated platform and requiring translation for the second platform; extracting from one of the modules data representing a group of functions exported by the one module; matching data of the one module to a group of function templates, at least some of the templates containing generalized program code written for the native platform and performing functions from the emulated platform; selecting at least one of the templates in response to the matching step; for each template selected, converting the generalized program source code in the template into expanded program code constituting at least part of the translation module for the one module; and repeating the extracting matching selecting, and converting steps for other of the modules. 2. A method according to claim 1, further comprising:determining that the one module matches one of a group of exception templates each containing program code; and generating at least part of the translation module for the one module from the program code of the one exception template. 3. A method according to claim 2, further comprising:bypassing matching the one-module data against the function templates when the current module matches one of the group of exception templates. 4. A method according to claim 1 wherein the one module has at least one parameter having one of a group of types, further comprisingmatching the one parameter to one of a group of types templates; and generating at least some of the program code of the translation module for the one module from the one types template. 5. A method according to claim 1, further comprising:determining that one of the templates specifies the name of one of a group of a code templates; and incorporating source code from the specified code template in the one template whenever the one template provides code for a translation module. 6. A method according to claim 1 wherein the interface modules have an import table and reside in at least one link library, and wherein the identifying step comprises:scanning the link library; and reading the names of the interface modules in the set from the import tables. 7. A method according to claim 1, further comprising:iterating the matching, selecting and converting steps over each of the functions in the group of functions. 8. A computer system for producing a set of synchronized translation modules each containing code for a translated version of a different interface representing that interface on a second platform, the system comprising:a set of interface files each comprising source code for implementing one of the interfaces; a set of header files associated with respective ones of the interface files and containing the names of functions exported by the respective interface files; a group of function templates each containing generalized source code for executing a group of translation functions; and a generator for matching certain of the interface files to at least one of the function templates and for converting the generalized code of the one function template into expanded source code for executing at least one of those functions exported by the interface files, the expanded code forming at least a portion of the translation modules. 9. A computer system according to claim 8, further comprising a group of exception template files associated with certain ones of the translation modules, and wherein the generator produces source code forming at least part of the code of the translation modules from one of the exception templates instead of from the function templates. 10. A computer system according to claim 8, further comprising a group of types templates respectively containing source code for a group of data types found in certain of the interface modules, and wherein the generator incorporates forming a part of the translation modules from those of the types templates corresponding to the data types found in the certain interface modules. 11. A computer system according to claim 8, further comprising an import library alternative names of functions exported by the respective interface files, and wherein the generator responds to the alternative names rather than to the names in the set of header files. 12. A computer-readable medium having computer-executable instructions for generating translation code representing a translated version of an interface written for a first platform on a second, different platform, comprising:selecting one of a plurality of generalized templates, each generalized template capable of performing a plurality of different functions based on information contained in an interface written for the first platform; and expanding the generalized template to produce modules constituting the translation code, the translation code representing the interface on the second platform. 13. A computer-readable medium having computer-executable instructions for generating a synchronized set of translation modules each containing program code representing a translated version of an interface module on a native platform, the method comprising:identifying the set of interface modules written for the emulated platform and requiring translation for the second platform; extracting from one of the modules data representing a group of functions exported by the one module; matching data of the one module to a group of function templates, at least some of the templates containing generalized program code written for the native platform and performing functions from the emulated platform; selecting at least one of the templates in response to the matching step; for each template selected, converting the generalized program source code in the template into expanded program code constituting at least part of the translation module for the one module; and repeating the extracting, matching, selecting, and converting steps for other of the modules. 14. A medium according to claim 13, including further instructions for:determining that the current module matches one of a group of exception templates each containing program code; and generating at least part of the translation module for the current module from the program code of the one exception template. 15. A medium according to claim 13 wherein the current module has at least one parameter having one of a group of types, the medium including further instructions for:matching the one parameter to one of a group of types templates; and generating at least some of the program code of the current translation module from the one types template. 16. A method for automatically generating translation code representing translated versions of interfaces written for a first platform on a second, different platform, comprising:constructing a generalized template capable of performing a plurality of different functions; extracting a plurality of functions performed by the interfaces written for the first platform; and expanding the generalized template for each of the function to produce modules constituting the translation code, the translation code representing all of the functions performed by the interfaces. 17. A method according to claim 16, further comprising:constructing a plurality of additional templates each associated with a particular type of parameter in the interfaces; and generating translation code from one of the additional templates for the parameters associated with any of the additional templates. 18. A method for automatically generating translation code representing a translated version of an interface written for a first platform on a second, different platform, comprising:selecting one of a plurality of generalized templates, each generalized template capable of performing a plurality of different functions based on information contained in an interface written for the first platform; and expanding the generalized template to produce modular, constituting the translation code the translation code representing the interface on the second platform. 19. The method of claim 18 and further comprising the step of repeating the selecting and expanding steps for each interface written for the first platform until all interfaces in a program are translated. 20. The method of claim 18, wherein the information comprises functions performed by the interface. 21. A digital computer system for executing an application program written for an emulated platform on a native platform, comprising:an operating system executing on the native platform; a set of interface modules executable on the emulated platform; an emulator for executing on the native platform an application program written for an emulated platform and having a set of interfaces executable on the emulated platform; a group of function templates each containing generalized code for executing a function; a group of types templates each containing conversion code for converting a data type of the emulated platform to a data type of the native platform; and a set of translation modules for executing translated versions of respective ones of the interface modules on the native platforms, the translation modules containing expanded code from the function templates and conversion code from the types templates. 22. A digital computer system according to claim 21, further comprising a group of exception templates containing code associated with particular respective ones of the interface modules, wherein at least some of the translation modules contain code directly contained in the exception modules.

1997-08-18

en

2000-02-15

US-90350092-A

High-frequency-excited laser for high output powers, particularly a CO.sub.2 ABSTRACT High-frequency-excited laser for high input powers, particularly a CO 2 stripline laser. For supplying high-power high-frequency energy to a laser, a matching unit (2) for the impedance is integrated in the laser, whereby the matching unit (2) contains a L-C element, whereby the inductance L and the capacitance C are variable, whereby the inductance can be set on the basis of variation of the length of the voltaicly conductive parts of a high-frequency feed and of a high-frequency conductance, whereby the capacitor is constructed of an outer conductor (10) and of an inner conductor (3) coaxial thereto, and whereby a coaxial slide ring (27) externally movable in an axial direction is in communication with the outer conductor (10). The slide ring (27) adjoins a dielectric cylinder (28) between the outer conductor (10) and the inner conductor (3), the outer conductor (10) carrying the inner conductor (3). The high-frequency-excited laser is provided for CO 2 stripline lasers. BACKGROUND OF THE INVENTION The present invention is directed to an HF-excited laser for high input powers, particularly a CO2 stripline laser. A prior art high power waveguide laser is disclosed in U.S. Pat. No. 4,939,738 and a stripline laser is disclosed in U.S. Ser. No. 743,709 filed Aug. 12, 1991. In HF-excited, higher-power lasers, having for example an input power of at least 1 kW, a matching unit transforms the impedance of the electrons that excite the plasma to the output impedance of the generator, this usually amounting to 50 Ohms at a given frequency. To this end, either two short circuit lines are connected into the input line in λ/4 spacing or a π element having a fixed series inductance and two variable case capacitances were hitherto utilized. However, the short-circuit lines cause high currents and high voltages on the 50 Ohm line, whereas the π element has a large physical space requirement. SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact structure of a matching element and, simultaneously, to minimize the current load. The object is achieved by a high-frequency-excited laser of the present invention for high input powers, particularly a CO2 stripline laser, which contains a laser housing and a matching unit integrated in the laser housing for matching the impedance to the impedance of a high-frequency feed. The matching unit contains a L-C element that acts a resonance transformer. The inductance L and capacitance C are variable. The inductance is set on the basis of a variation of the length of the voltaicly conductive parts between an HF feed and an HF conductance of a high-frequency connection. The capacitor is constructed with an outer conductor and an inner conductor coaxial thereto. A coaxial slide ring movable from the outside in an axial direction is in communication with the outer conductor. The slide ring adjoins a dielectric between the outer conductor and the inner conductor. The inner conductor has a capacitor electrode cylinder with an enlarged diameter and the outer conductor carries the inner conductor. The L-C element in the present invention acts as a resonance transformer at the given frequency. The specific structure guarantees an HF-tight (high-frequency tight) termination of the laser and an HF-tight connection to a high-frequency cable. Advantageously, the inner conductor forms a region having an enlarged diameter, whereby the capacitance of the capacitor is defined by the axial position of the slide ring vis-a-vis this region. An optimum exploitation of the space of the existing laser housing is enabled in that the outer conductor is designed coaxially vis-a-vis the laser housing and displaceable relative thereto in an axial direction, in that the inner conductor is insulated from and conducted through a face plate of the outer conductor, in that the inner conductor contains a binder element movable in an axial direction behind this face plate, and in that the axial position of the outer conductor vis-a-vis the housing defines the inductance that is set. The outer conductor thereby advantageously completely surrounds the inner conductor up to a plug-type connection for a coaxial plug and adjoins the housing wall in HF-tight fashion. The laser can thus be simply connected in an HF-tight manner to a connecting cable. BRIEF DESCRIPTION OF THE DRAWING The features of the present invention which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages, may best be understood by reference to the following description taken in conjunction with the accompanying drawing, and in which: The single FIGURE depicts a high-frequency-excited laser according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT A matching unit 2 is accommodated in a laser housing 1. The matching unit 2 is composed of an L-C element, whereby an inductance is formed by the entire length of the HF feed to and conductance from the gas discharge space (not shown in the drawing). The HF feed is fashioned as inner conductor 3 that is composed of an inner plug contact 4, of a pin 5, of a capacitor electrode cylinder 6 and of an inner conductor 7 whose electrically effective length is variable. This HF feed is in communication via a connection element 8 with a laser electrode terminal 9 and is displaceable along the latter in an axial direction. The end face of the capacitor electrode cylinder 6 is connected to the variable inner conductor 7 and is insulated from a face plate 13 of the outer conductor 10 by an insulating part 12 of plastic, preferably of Teflon and is mechanically supported against this face plate 13. The outer conductor 10 is fashioned displaceable in axial direction along the laser housing 1 and forms a HF-tight termination relative to the laser housing 1. The face plate 13 is connected to the outer cylinder 14 that projects beyond the capacitor electrode cylinder 6 in axial direction and is completed via an outer plate 17 and an outer tube 24 adjoining thereat. The outer tube 24 has its end region connected to an outside contact ring 25 and is supported against the inner conductor 3 via an insulating washer 26. The outer contact ring 25 serves the purpose of contacting along an outer contact of a coaxial plug (not shown) whose shielded contact contacts the inner plug contact 4 of the inner conductor 3. A slide ring 27 is arranged displaceable in an axial direction in the outer cylinder 14. The slide ring 27 is supported relative to the outer cylinder 14 via contact springs and is separated from the inner conductor 3 by a dielectric cylinder 28. The dielectric cylinder 28 lies on an insulator flange 19 that is preferably composed of Teflon. The insulator flange 19 surrounds an insulating cylinder 20 that is preferably composed of ceramic and extends to the capacitor electrode cylinder 6. The dielectric cylinder 28 adjoins a stop ring 22 of the insulator part 12, whereby the stop ring 22 serves as a stop for any displacement of the slide ring 27. The slide ring 27 is externally set by displacing the pin 29 in the direction of arrow B. After the balancing, the pin 29 can be fixed along the outer plate 17 and can then be cut off since a readjustment is not provided. After the balancing of the inductance by shifting the entire matching unit 2 in the direction of arrow A, the face plate 13 can be fixed along the laser housing 1. The insulating cylinder 20 is arranged between the outer plate 17 and the capacitor electrode cylinder 6 in an extension of the outer conductor 24 and, via a sinuous spring 21, the insulating cylinder 20 presses the capacitor electrode cylinder 6 against the insulating part 12 and presses the latter against the face plate 13. The invention is not limited to the particular details of the apparatus depicted and other modifications and applications are contemplated. Certain other changes may be made in the above described apparatus without departing from the true spirit and scope of the invention herein involved. It is intended, therefore, that the subject matter in the above depiction shall be interpreted as illustrative and not in a limiting sense. What is claimed is: 1. A high-frequency-excited laser for high input powers, particularly a CO2 stripline laser, which contains a laser housing and a matching unit integrated in the housing for matching an impedance of the laser to an impedance of a high-frequency feed connected thereto, comprising: an L-C element in the matching unit, the L-C element acting as a resonance transformer; an inductance and a capacitance of the L-C element being variable; the inductance being set by a variation of a length of voltaicly conductive parts of the high-frequency feed and a high-frequency conductance of a high-frequency connection; the capacitance being provided by a capacitor that is formed by an outer conductor and an inner conductor coaxial thereto; an externally movable coaxial slide ring that is movable in an axial direction being in communication with the outer conductor, said slide ring adjoining a dielectric between the outer conductor and the inner conductor; the inner conductor having a capacitor electrode cylinder with an enlarged diameter; and the outer conductor carrying the inner conductor. 2. The laser according to claim 1, wherein the capacitance of the capacitor is defined by an axial position of the slide ring along the capacitor electrode cylinder. 3. The laser according to claim 1, wherein the matching unit is in a coaxial relationship with the laser housing and displaceable in an axial direction relative to said laser housing; wherein the inner conductor is conducted through a face plate of the outer conductor in an insulated manner; wherein the inner conductor contains a connection element that is adjustable in at least an axial direction behind the face plate; and wherein an axial position of the outer conductor along the laser housing defines the inductance. 4. The laser according to claim 1, wherein the outer conductor completely surrounds the inner conductor up to a plug connection for a coaxial plug, wherein the outer conductor shields the inner conductor in a high-frequency tight manner, and wherein the outer conductor adjoins the laser housing in a high-frequency tight manner. 5. A high-frequency-excited laser for high input powers having a housing and a matching unit integrated in the housing for matching an impedance of the laser to an impedance of a high-frequency feed connected thereto, comprising:an L-C element in the matching unit, the L-C element having a variable inductance and a variable capacitance; the inductance being set by at least a variation of a length of voltaicly conductive parts of the high-frequency feed; the capacitance being provided by a capacitor that is formed by an outer conductor and an inner conductor coaxial thereto with a dielectric between the inner and outer conductors; an externally movable coaxial slide ring adjoining the dielectric and in communication with the outer conductor, the slide ring being movable in an axial direction; and the inner conductor having a capacitor electrode cylinder with an enlarged diameter and the outer conductor carrying the inner conductor, the inner conductor being a part of the voltaicly conductive parts. 6. The laser according to claim 5, wherein the capacitance of the capacitor is defined by an axial position of the slide ring along the capacitor electrode cylinder. 7. The laser according to claim 5, wherein the matching unit is in a coaxial relationship with the laser housing and and displaceable in an axial direction relative to said laser housing; wherein the inner conductor is conducted through a face plate of the outer conductor in an insulated manner; wherein the inner conductor contains a connection element that is adjustable in at least an axial direction behind the face plate; and wherein an axial position of the outer conductor along the laser housing defines the inductance. 8. The laser according to claim 5, wherein the outer conductor completely surrounds the inner conductor up to a plug connection for a coaxial plug, wherein the outer conductor shields the inner conductor in a high-frequency tight manner, and wherein the outer conductor adjoins the laser housing in a high-frequency tight manner. 9. A high-frequency-excited laser for high input powers having a housing and a matching unit integrated in the housing for matching an impedance of the laser to an impedance of a high-frequency feed connected thereto, comprising:an L-C element in the matching unit, the L-C element having a variable inductance and a variable capacitance; the inductance being set by at least a variation of a length of voltaicly conductive parts of the high-frequency feed; the capacitance being provided by a capacitor that is formed by an outer conductor and an inner conductor coaxial thereto with a dielectric between the inner and outer conductors, the inner conductor being conducted through a face plate of the outer conductor in an insulated manner and the inner conductor having a connection element that is adjustable in at least an axial direction; an externally movable coaxial slide ring adjoining the dielectric and in communication with the outer conductor, the slide ring being movable in an axial direction; the inner conductor having a capacitor electrode cylinder with an enlarged diameter and the outer conductor carrying the inner conductor, the capacitor electrode cylinder being a part of the voltaicly conductive parts; the capacitance being defined by an axial position of the slide ring along the capacitor electrode cylinder; and the inductance being defined by an axial position of the outer conductor along the housing of the laser. 10. The laser according to claim 9, wherein the outer conductor completely surrounds the inner conductor up to a plug connection for a coaxial plug, wherein the outer conductor shields the inner conductor in a high-frequency tight manner, and wherein the outer conductor adjoins the laser housing in a high-frequency tight manner.

1992-06-24

en

1993-09-14

US-42073873-A

Card advancing and function performing methods and apparatus ABSTRACT Card advancing and function performing methods and apparatus place a card in a first region, and advance the card from such first region by way of a first path to a second region, whereby a first edge portion of the card leads an opposite second edge portion of the card. The desired function relative to the card is performed in the second region, and the second edge portion is made to lead the first edge portion of the card. The card is returned from the second region to the first region by way of a second path different from the first path with the second edge portion continuing to lead the first edge portion of the card. The second path is located between the first path and the second region, and the leading second edge portion is depressed into the second path for a return of the card to the first region. Westover et al. 1 1 CARD ADVANCING AND FUNCTION PERFORMING METHODS AND APPARATUS [75] Inventors: Dwight G, Westover, Sierra Mudre; Frederic F. Grant, Bellfiower. both of Calif. 173] Assignee: Bell & Howell Company, Chicago, [22] Filed: Nov. 30, I973 [21] Appl. No.: 420.738 [52] US. Cl. 271/3; 271/D1G. 9', 346/138 [51] Int. Cl B6511 5/06; B65h 29/22 [58] Field of Search 271/3, 4, DIG. 9; 346/138 [56] References Cited UNITED STATES PATENTS 2,431,360 11/1947 Philpott 346/138 3.755.653 8/1973 Venker H 271/DIG. 9 3,790.15) 2/1974 Hutzmann et a1 271/4 51 Aug. 19, 1975 Primary ExaminerEv0n C. Blunk Assistant Examiner-Robert Saifer Attorney, Agent, or Firm-Benoit Law Corporation [57 ABSTRACT Card advancing and function performing methods and apparatus place a card in a first region. and advance the card from such first region by way of a first path to a second region, whereby a first edge portion of the card leads an opposite second edge portion of the card. The desired function relative to the card is performed in the second region, and the second edge portion is made to lead the first edge portion of the card. The card is returned from the second region to the first region by way of a second path different from the first path with the second edge portion continuing to lead the first edge portion of the card. The second path is located between the first path and the second region, and the leading second edge portion is depressed into the second path for a return of the card to the first region. 17 Claims, 16 Drawing Figures PATENTED AUG-I 9 I975 Siii PATENTH] AUG-1 9 I975 sum 5 0F g CARD ADVANCING AND FUNCTION PERFORMING METHODS AND APPARATUS CROSS REFERENCES The following United States patents and/or copending patent applications. filed of even date. disclose or disclose and claim subject matter which is shown herein and/or which may be employed in the practice of the subject invention. These patents or applications are assigned to the same assignee as the subject patent application or patent and are herewith incorporated by reference herein. Ser. No. 420.503. entitled Communication Methods and Billing Systems, by R. A. Boyle. E. S. Gilchrist and R. L. Visser; Ser. No. 420,734, entitled Communication Methods and Billing Systems. by E. S. Gilchrist and R. L. Visser'. Ser. No. 420,735, entitled Methods and Apparatus for Performing a Function Relative to a Card. by F. F. Grant; Ser. No. 420.736, entitled Printing Apparatus. by E. S. Gilchrist and F. F. Grant; Ser. No. 420,737, entitled Sheet Advancing Methods and Apparatus. by F. F. Grant; Ser. No. 420.739. entitled Printing Methods and Apparatus. by R. M. McManaman; and Ser. No. 420. 740, entitled Character Expressing and Printing Methods and Apparatus, by E. S. Gilchrist and A. B. Nayak. BACKGROUND OF THE INVENTION 1. Field of the lnvention The subject invention broadly relates to card advancing and function performing methods and apparatus. By way of example. and not by way of limitation. a field of utility of the subject invention resides in card printing and/or reading equipment wherein cards are moved to and from a printing and/or reading station. 2. Description of the Prior Art Despite the vast amount of prior-art techniques and equipment in the above mentioned field. there persists a need for methods and apparatus wherein cards are economically and reliably advanced from a first region to a second region where a desired function is performed relative to the card. and are thereupon returned to the first region. There also exists a need for economic and reliable methods and apparatus wherein cards from a first stack are serially processed and are thereupon piled up on a second stack. Existing solutions or proposals in this field are either unreliable or rather expensive. Moreover, prior-art solutions which would have the requisite reliability in card handling and feeding are incapable of satisfying an existing need for portable or compact and inexpensive stationary card moving and function performing apparatus. SUMMARY OF THE INVENTION It is an object of this invention to satisfy the above mentioned needs. It is an object of this invention to provide improved methods and apparatus for performing one or more functions relative to one or more cards. It is an object of this invention to provide improved methods and apparatus for moving or advancing cards. LII it is a related object of this invention to provide improved methods and apparatus for advancing cards from a stack of cards. Other objects of this invention will become apparent in the further course of this disclosure. From one aspect thereof, the subject invention resides in a method of performing a function relative to a card, and resides, more specifically, in the improvement comprising in combination the steps of placing said card in a first region, advancing said card from said first region by way of a first path to a second region. whereby a first edge portion of the card leads an opposite second edge portion of the card. performing said function relative to said card in said second region, providing a second path different from said first path and leading from said second region to said first region. and locating said second path between said first path and said second region, making said second edge portion lead said first edge portion of the card, depressing said leading second edge portion into said second path. and returning said card from said second region to said first region by way of said second path different from said first path with said second edge portion continuing to lead said first edge portion of the card. From another aspect thereof, the subject invention resides in a method of performing a function relative to a number of cards, and resides, more specifically, in the improvement comprising in combination the steps of placing said cards in the form of a stack of cards in a first compartment of a first region. advancing said cards one by one from said stack of cards in said first compartment to a second region by way of a first path leading from said first compartment to said second region, whereby a first edge portion of each card leads an opposite second edge portion of that card, performing said function relative to each card in said second region, providing a second path different from said first path and leading from said second region to said first region, and locating said second path between said first path and said second region, making said second edge portion of each card lead said first edge portion of that card and moving each card from said second region to a second compartment in said first region before said function is performed relative to the next card in said stack, the cards being moved from said second region by said second compartment in said first region by depressing said leading second edge portion of each card into said second path and advancing each card by way of said second path. the latter advanced cards being stacked in said second compartment in said first region. From another aspect thereof. the subject invention resides in apparatus for performing a function relative to a card, and resides. more specifically. in the improvement comprising. in combination. means for storing said card in a first region of said apparatus. means defining a first channel between said first region and a second region of said apparatus. means for advancing said card from said first region by way of said first channel to said second region, whereby a first edge portion of the card leads an opposite second edge portion of the card. means for performing said function relative to said card in said second region, means defining a second channel extending between said second region and said first region and being located between said first channel and said second region, means for reversing the direction of movement of said card whereby said second edge portion leads said first edge portion. and means for depressing said leading second edge portion into said second channel, said reversing means including means for returning said card from said second region to said first region at said reversed direction of movement and by way of said second channel. From another aspect thereof, the subject invention resides in apparatus for performing a function relative to a number of cards, and resides, more specifically, in the improvement. comprising. in combination, means for defining a first compartment, means for receiving said cards in the form of a stack of cards in said first compartment, means for providing a first channel between said first compartment and a predetermined region of said apparatus, means for advancing said cards one by one from said stack of cards in said first compartment to said predetermined region by way of said first channel, whereby a first edge portion of each card leads an opposite second edge portion of that card, means for performing said function relative to each card in said predetermined region, means for defining a second compartment. means for providing a second channel extending between said predetermined region and said second compartment and being located between said first channel and said predetermined region, means for reversing the direction of movement of each card in said predetermined region whereby said second edge portion of each card leads said first edge portion of that card, and means for depressing said leading second edge portion of each card into said second channel, said reversing means include means for moving each card from said predetermined region to said second compartment before said function is performed relative to the next card in said stack, and for so moving said card in said reversed direction of movement from said predetermined region to said second compartment by way of said second channel, and means for stacking said moved cards in said second compartment. From yet another aspect thereof, the subject invention resides in apparatus for performing a function relative to a card, and resides, more specifically, in the improvement comprising in combination, means for storing said card in a first region of said apparatus, means defining a first channel between said first region and a second region of said apparatus, means defining a second channel extending between said second region and said first region and being located between said first channel and said second region, means for advancing said card from said first region by way of said first channel to said second region, whereby a first edge portion of the card leads an opposite second edge portion of the card, means in said second region for moving said card in a first direction wherein said first edge portion leads said second edge portion. and alternatively in a second direction wherein said second edge portion leads said first edge portion, means for performing said function relative to said card in said second region, means at said second region for positioning said leading first edge portion of said card into engagement with said card moving means in said second region and for alternatively depressing said leading second edge portion of said card into said second channel, and means for returning said card from said second region to said first region by way of said second channel with said second end portion leading said returning card through said second channel. The expression card" as herein employed is not intended to be interpreted in a limiting sense. Rather, the meaning of that term is intended to include not only cards in their popular meaning, but also other sheetlike objects or sheets of material. BRIEF DESCRIPTION OF THE DRAWINGS The invention will become more readily apparent from the following detailed description of preferred embodiments thereof, illustrated by way of example in the accompanying drawings, in which like reference numerals designate like or functionally equivalent parts, and in which: FIG. I is a plan view ofa record card that may be employed in the practice of the subject invention; FIG. 2 is a plan view, with removed top, of a compact card moving and function performing apparatus in accordance with a preferred embodiment of the subject invention; FIG. 3 is a section taken along the line 3 in FIG. 2, with the printing mechanism having been removed; FIG. 4 is a section taken along the line 4 4 in FIG. 2, with the printing mechanism having been removed; FIG. 5 is a section taken along the line 5 5 in FIG. 2, with the printing mechanism having been removed; FIG. 6 is an offset section taken along the line 6 6 in FIG. 3; FIG. 7 is a partial sectional elevation taken along the line 7 7 in FIG. 6; FIG. 8 is an offset section taken along the line 8 8 in FIG. 4; FIGS. 9 and 10 are enlarged fragmentary views of FIG. 4; FIG. 1] is a fragmentary sectional view of the printing mechanism taken at the line II 11 in FIG. 2; FIG. 12 is a partial section taken along the line 12 I2 in FIG. 11; FIG. 13 is a plan view of the printing head with associated parts; FIG. I4 is a partial section taken along the line 14 14 in FIG. 11; FIG. 15 is a sectional elevation of a detail of FIG. 11 on an enlarged scale; and FIG. 16 is a block diagram of electronic equipment used in the portable billing apparatus herein disclosed and controlling functions thereof. DESCRIPTION OF PREFERRED EMBODIMENTS By way of example, and not by way of limitation, the apparatus 28 shown in the drawings may have utility as a portable billing apparatus and will occasionally be referred to as such in the further course of this disclosure. For instance, the portable billing apparatus 28 may be employed to provide bills and billing information at customers addresses for utility consumption of services rendered. In the latter vein, FIG. 1 shows a record card 23 on which account and billing information has been printed in three fields 31, 32 and 38. Depending on the application, some of that information may be preprinted on the record card 23, and the remaining information may then be printed on the card 23 by the portable billing apparatus 28. The record parts 31 and 38 may then be handed to the particular customer as a statement or bill. The record part 32 may be returned to the billing center for the purpose of subsequent verification of the amount due from the particular customer. When paying his bill, the customer would send the record part 38 along with his payment and the record part 38 would then be compared with the record part 32 to verify that the customer has paid his entire bill. The portable billing apparatus 28 in accordance with the illustrated preferred embodiment of the subject invention will now be described with the aid of FIGS. 2 to 15. The portable billing apparatus 28 has a housing 41 having a slot 42 at one end thereof for receiving a record card 22 on which data are to be printed. The record card 23, shown in dotted outline in FIG. 2, may be of the type shown in FIG. I and described above. A supporting structure with side frames 43 and 44 is provided inside the housing 41 for mounting the mechanical parts of the billing apparatus 28. A card receiving chamber 45 is defined inside the slot 42 by a pair of card guides 46 and 47 having flared or inclined receiving lips (see FIGS. 2 and 4). Lateral guides 51 and 52 have flared or inclined lips 53 and 54 for guiding the card 23 laterally where necessary. A card receiving platform 56 is resiliently mounted below the receiving chamber 45 by springs 47' relative to a supporting plate 48. If desired, several cards 23 may be inserted at a time through the slot 42 and receiving chamber 45 and stored on the platform 56. A lip 49 on the supporting plate 48 prevents more than one card from being fed at a time from the platform 56 to the printing area of the portable biller. The portable biller 28 includes a handle 61 which has a manually engageable piece 62. The handle 61 is attached by screws 63 to an actuator block 64 which is slidable along bars 65 and 66. A screw 68 connects a lug 69 to an extension bar of an actuating arm 72. The actuating arm 72 has an offset extension 73 which engages the forward end of a carriage 74 (see FIG. 4). In this manner, the handle 6I is capable of causing sliding motion of the carriage 74 along a track 76. The carriage 74 has an extension lip 77 bent over the actuating arm extension 73. A resilient bracket 79 mounts a roller 81 on the carriage 74 for limited rotary movement relative to the platform 56 or the card or cards located thereon. A limited peripheral portion of the roller 81 is occupied by a high friction material 82, while the remaining peripheral portions of the roller 8] are occupied by a low friction material 83. For the purpose of illustration, the low friction material 83 has been shown in black in FIG. 4, while the high friction material 82 has been shown in white. The roller 81 has a flat top 84 adjacent the bracket 79 so that the roller 8] is only capable of limited rotary movement, such as an angular movement of [5 in both clockwise and counterclockwise directions. The roller 8I is a unidirectional card advancing device. If the handle 61 and the carriage 74 are pushed to the left as seen in FIGS. 3 and 4, the high friction between the roller portion 82 and the inserted card 23 above the platform 56 causes the roller 81 to rotate slightly. This rotation is limited by the abutment of the flat roller top 84 with the supporting bracket 79 so that the high friction roller portion 82 remains in contact with the inserted card 23. Accordingly. upon further movement of the carriage 74, the card engaged by the high friction portion 82 of the roller 82 is driven to the left into the path 85 shown in FIG. 4. A support 86 and a hold down spring 87 are mounted adjacent the gate 85. The support 86 functions as a guide. As seen in FIG. 9, the guide 86 and hold down spring 87 cooperate in positioning the leading edge of the advancing card 23 in a recess 88 of a drum 89. The object of this juncture is to wrap the card around the drum for printing and other purposes more fully described below. To this end. the drum 89 has a shaft 91 which. as more fully seen in FIG. 8, is rotatable in two bearings 93 and 94 attached to the frame structures 43 and 44. A gear wheel 95 is attached to the drum 89 in order to drive the drum. As seen in FIG. 3, a hook 97 is attached to the drive block 64. When the handle 61 advances the drive block 64 to the left, the book 97 engages a hook 98 fastened to a drive belt 99. The drive belt 99 is in forcetransmitting engagement with the drive gear wheel 95 of the drum 89 and extends also over an idler pulley I00 seen in FIG. 3. Accordingly, the advancing block 64 drives the drum 89 via the hooks 97 and 98 and the belt 99. The drum 89 is thus rotated counterclockwise in the direction of an arrow 10] shown in FIGS. 4 and 9. The advanced card 23 is wrapped around at least part of the periphery of the drum 89 during each rotary motion. To this end. belts 103 ofa flexible metal or a flexible, tough plastic are attached by fasteners 104 to the periphery of the drum 89. These belts 103 further extend from the drum 89 to and around the periphery of a drum I05. The ends of the belts I03 which are opposite to the ends attached to the drum 89 are attached to the drum I05. The drum I05 has a shaft I06 rotatable in bearings I08 and I09 attached to the frame structures I9I and I92. When the drum is rotated counterclockwise in the direction of the arrow 10] by the drive belt 99, portions of the belt 103 are progressively unwound from the drum I05 and wound onto the advancing card 23 on the drum 89. In this manner, the card 23 is progressively wound onto the drum 89 and is held down on the drum by the belts 103. Wrapping of the card 23 around at least part of the drum 89 is not resisted by the card drive roller 8]. Rather, the advancing drum 89 and belts I03 will pull the engaged card 23 along the platform 56 which imparts a clockwise rotary motion to the roller 81. In this manner. the low friction portion 83 of the roller will be drawn into contact with the sliding card. Because of the low friction nature of the roller portion 83, the roller 81 will then not resist advancement of the card along the platform 56 and onto the drum 89. While the handle 6I and drive belt 99 are being ad vanced, a coil or clock spring is partially unwound from a drum I12 shown in FIGS. 3 and 6. A shaft I14 is attached to the mounting structure 44 in order to mount the spring drum 112 for rotary movement. A coil or clock spring I I5 is wound when the wrapped portions of the belts I03 are unwound from the drum 105 by the rotating main drum 89. The spring IIS has an end II6 attached to the shaft of the drum 105. An opposite end of the spring 115 extends around a pin 117 which is attached to the mounting structure 191. In this manner, the belts 103 are spring tensioned when they are wound onto the card on the drum 89. By way of alternative. the shaft I06 can be made stationary relative to the mounting structures I9I and 192. In that case, the inner end of the spring 115 could be attached to the shaft 106 and the outer end of the spring 115 could be attached to the drum 105, with the drum 105 being then mounted for rotation on the shaft 106. At this juncture, a closer consideration of the nature and function of the slide block assembly 64 will be helpful. As seen in FIG. 3, the slide block assembly 64 is composed to a first slide block 122 and a second slide block 123. The handle 61 is attached by the fasteners 63 to the slide block 122. The lower block has a fork portion 124 which straddles a bushing 125 slidable on the bar 65. Similarly, the block 122 has a fork 127 which straddles a bushing 128 slidable on the bar 66. The bushing 125 fits into a bore in the slide block 122, while the bushing 128 fits into a bore in the slide block 123. In this manner, the handle 61 moves the blocks 122 and 123 of the slide block assembly 64 in unison until the block 123 is stopped. This occurs when a roller 131 drops into a depression 132 in a bar 133 as shown in FlG. 7. The roller 131 is mounted by a linkage 135 for rotation relative to the bar 133. The linkage 135 is connected to a bracket 136 which is attached to the bar 71. The bar 71, in turn, is attached to the slide block 123 at 68 and 69. When the slide block assembly 64 is advanced by the handle 61, the roller 31 rolls along the bar 133 until it drops into the depression 132 as indicated in FIG. 7. A spring 137 biases the roller 131 against the bar 133 and into the depression 132. Engagement of the roller 131 with the bar 133 at the depression 132 stops further movement of the slide block 123. Continued movement of the handle 61 then pulls the bushing 138 by action of the fork 127 away from the slide block 123. At the same time, the slide block 122 pulls off the bushing 125 retained by the fork 124 of the arrested slide block 123. At that instant, the carriage 74 will have stopped its motion on the track 76 since it is connected at 73 and 77 to the bar 71 which, in turn, is attached to the slide block 123 as mentioned above. This means that the unidirectional card advancing roller 81 will have advanced the leading edge of the engaged card 23 into the recess 88 and under part of the belt 103 as shown in FIG. 9, when the sliding block 122 separates from the sliding block 123. Continued movement of the handle 61 will then further advance the sliding block 122 toward a stop 138. At this juncture, it will be noted that the hook 97 shown in FIG. 3 is attached to an extension 139 of the sliding block 122 and is initially spaced from the hook 98 on the drive belt 99. This provides a lost motion connection between the hooks 97 and 98, whereby the hook 98 only becomes engaged when the leading edge of the advanced card 23 has been located in the recess 88 of the main drum 89 as shown in FlG. 9. Once the engagement between the hooks 98 and 99 has been established, further movement of the slide block 122 away from the then arrested slide block 123 will advance the drive belt 99 which, in turn, will rotate the drum 98 counterclockwise in the direction of the arrow 101 by action on the drive wheel 95. [n this manner, the advanced card 23 will be wrapped around at least part of the periphery of the main drum 89 as mentioned above. A dashpot assembly 141 controls the forward speed of the slide block assembly 64. The dashpot assembly 141 has an air cylinder 142 attached to the mounting structure 44 by a bracket 143. A piston 145 shown in dotted lines in FIG. 3 is fitted for sliding movement in the air cylinder 141. An adjustable air valve 146 on the cylinder 141 permits adjustment of the rate of movement of the piston in the cylinder. A piston rod 147 is connected to the piston 145. A link 148 connects the free end of the piston rod 147 to a lever 149 which is pivoted relative to the mounting structure 44 at 151. A link 152 is pivoted on the extension 139 of the slide block 122 and acts on the lever 149 to move the piston 145 in the cylinder 142 to the left as seen in FIG. 3, against the air resistance provided by the valve 146 and against the bias of a spring 153. This occurs when the slide blocks 122 and 123 are advanced by the handle 61 and continues when the slide block 122 is further advanced by the handle 61 after separation from the slide block 123; if desired. At the end of the track provided by the bars 65 and 66, the motion of the slide block 122 is arrested by a stop 138. The slide block 122 may then be returned to the slide block 123 as more fully described below. A double pawl 155 acts on a ratchet wheel 156 to arrest rotary movement of the drum 89 under the influence of the tensioned spring 115 and rotary movement of the drum 105 also under the influence of the tensioned spring 115. As shown in FIG. 8 the ratchet wheel 156 is connected to the drum 89. The pawl 155 may now be actuated in a controlled manner to permit stepped movements of the drum 89 during printing of the desired information on the wrapped card on the drum. This phase of the operation of the portable printer 28 will be more fully described below. For the purpose of the present disclosure, it is assumed that the required information has been printed onto the wrapped card and that it is desired to return this card 23 to the exit slot 42. At this juncture, it will be noted that the link 152 is designed as a trigger biased by a spring 157. Accordingly, a link 152, which will override the free end of the lever 149 during movement of the slide block 122 toward the stop 138, can move back over the free end of the lever 149 when the slide block 122 is returned to its original position (see FIG. 3). [n the meantime, the bias spring 153 is free to return the lever 149 to its original position shown in FIG. 3. During the printing process, the spring 115 rotates the drum 89 clockwise in the direction of an arrow 161 as seen in FIG. 10. Such movement of the drum 89 will eventually cause an unwrapping of the card 23 from the drum 89. During such unwrapping the hold down spring 87 will cause the then leading edge of the card 23 to impinge upon the guide 86 in its lower surface as shown in FIG. 10. This guides the card 23 into a return gate or channel 162. As seen from FlG. 10 the hold down spring effectively depresses the then leading edge of the card 23 into the return gate or channel 162, with the return gate or channel 162 being located between the gate or channel and the second region of the apparatus occupied by the drum 89. During such unwrapping of the card, the spring 115 rotates the drum counterclockwise as seen in FIG. 4 in order to wind the previously unwound portions of the belts 103 again onto the drum 105. In this manner, the spring also causes rotation of the drum 89 in the direction of the arrow 161. For this to occur it is necessary that the hook 97 on the slide block 122 be spaced from the hook 98 on the drive belt 99 sufficiently to permit an unwrapping of the card 23 from the drum 89. By way of example, this may be accomplished simply by manually engaging the handle portion 62 and retracting the handle 61 from the end position at 138 to the midposition at which the slide block 122 again engages the previously separated slide block I23. Alternatively, and in accordance with the illustrated preferred embodiment, an arm 292 cooperates with a pin 293' to form a one-way clutch between the gear wheel 95 and the drum 89 and the bias of the partially unwound spring 110 may then be employed to return the slide block 122 to its midposition. In that case the gear wheel 95 acts through the pin 293' and arm 292 to advance the drum 89 in the forward direction when a card is being wrapped thereon. The drum 89 then stays in the advanced position until the double pawl 155 is released. While the drum stays in the advanced position, the spring 110 returns the gear wheel 95, drive belt 99 and slide block 122 to a midposition. It will be recalled at this juncture that the slide block 122 became separated from the slide block 123 when the roller 131 became arrested in the recess 132 of the bar 133. as shown in dotted lines in FIG. 7. The partial backward movement of the handle 61 just described may be effected in one operation with the previously described forward actuation. In that case the operator would actuate the handle 61 to push the slide block 122 forward to the maximum advanced position 138 and would then actuate the handle 61 to return the slide block 122 into engagement with the slide block 123. In accordance with the illustrated preferred embodiment of the invention, the slide block 123 is connected to a free end of a spring 164 shown in FIG. 7 via the bar 71, bracket 136 and fastener 165. The spring 164 is wound on a drum 166 which is rotatable about a shaft 167 as shown in FIG. 7. The spring 164 is tensioned to wind itself fully onto the drum 166. Accordingly, the spring 164 biases the slide block 123 against the slide block 122 so that the slide block 123 will follow the slide block 122 when the handle is actuated to move the slide block assembly 64 to the left as seen in FIG. 3. Similarly, the operator will feel the instant at which the slide block 122 has reengaged the slide block 123 since the spring 164 is then wound on the drum 166 except for a small end portion attached to the bracket 136, and since the roller 131 is then arrested in the recess 132 of the bar 133. The operator will then release the handle portion 62 until the printing process has been completed and the card has been unwrapped from the drum 89. The leading edge of the unwrapping card proceeds through the gate 162 into a return chamber 167 delimited by shield I68, and onto a platform 169. At this juncture. a function which takes place during the previously described advancement of the slide block 164 has to be considered. In particular, a roller 171 is advanced from its initial position shown in FIG. 4 to an advanced position near the card return chamber 167 when the slide block 64 is first advanced to the left as seen in FIG. 3. To this end, an arm 172 shown in FIGS. 3 and 4 projects from the bar 71 which, as previously mentioned, has a portion 69 attached to the lower slide 123 at 68. The actuating arm 172 has a pin 172' which engages a carriage 173 as shown in FIG. 4. Accordingly, the carriage 173 is advanced along a track 174 in a direction toward the card return chamber 167 when the slide block 64 is first moved to the left by the handle 61 from its initial position shown in FIG. 3. The carriages 74 and 173 thereby move in unison since they are both actuated from the same bar 71 attached to the slide block 123. Both carriages 74 and 173 stop when the roller 13] becomes arrested in the recess 132 of the bar 133 shown in FIG. 7 and when the slide 122 then separates from the slide 123 as previously described. At that juncture, the roller 171 is located in the vicinity of the card return chamber 167. Like the roller 81, the roller 171 is designed as a unidirectional card advancing device having a portion 176 of high friction material extending over part of its periphery and a portion 177 of low friction material extending over the remainder of its periphery. The roller 171 is mounted for limited rotary movement on a resilient support 178 which is attached to the carriage 173. A flat roller top 179 limits angular movement of the roller 171 to about l5 in each direction. Because of the presence of the low friction portion 177 of the roller 171, the leading edge of the returning card can readily slide in between the platform 169 and the roller 17] since the rotational position of the roller 17! is then such that the high friction portion 176 of the roller is spaced from the return platform 169. Also, the shield or plate 168 is resiliently mounted by springs 181 while the roller 171 is resiliently mounted by the previously mentioned support 178. After the printing process as to the particular card 23 has been completed, the operator engages the handle 61 at its portion 62 and moves the slide block assembly 64 to the right as seen in FIG. 3. This actuates the carriages 74 and 73 from their above mentioned advanced position toward their initial position shown in FIG. 4. In terms of roller 81, this movement has no effect on any card, since it will cause position of the low friction portion 83 adjacent the platform 56. Accordingly. no card is removed from the platform 56, even if more than one card were previously positioned on the platform 56. On the other hand, movement of the carriage 173 from the above mentioned advanced position toward the initial position shown in FIG. 4 will rotate the roller I71 sufficiently to place the high friction portion into engagement with the card that has been returned through the chamber 167. Accordingly, the returning roller 171 will grip the card with its high friction portion and will slide it along the return platform 169 thereby separating it fully from the drum 89. In this manner, the unidirectional card advancing device in the form of the roller 171 will place the leading edge of the returned card at the slot 42, such that the returned card 23 can be manually engaged and removed from the apparatus 28. In the process of its renewal, the card will subject the roller 171 to a limited angular movement such that the low friction portion 177 moves into engagement with the card. The roller 171 will then offer no resistance to a manual removal of the card from the printing apparatus 28. The next card may then be moved into engagement with the drum 89 in the above mentioned manner by actuation of the handle 61. The printing process will now be fully described with reference to the accompanying drawings. In particular, FIG. 5 shows the previously mentioned double pawl 155 which pivots around an axis 183. The pawl 155 is of a ferromagnetic material and is actuated by electromagnetic coils or solenoids 184 and 18S located on an armature 186. The pivot shaft 183 may be connected to the armature 186. The double pawl 155 is designed in the manner of an escapement which. upon alternative energization of the coils 184 and 185. will permit stepped advancement of the ratchet wheel 156 and drum 89 in the direction of the arrow 187 which corresponds to the arrow 161 in FIG. 10. In this manner. advancement of the drum 89 can be easily controlled so that the wrapped card 23 on the drum is located. row for row. in the desired positions for the printing process. As shown in FIGS. 2 and 4. the previously described roller 105 and the printing assembly 189 are supported by side plates 191 and 192 which are pivoted relative to the frame structure at 193 so that the roller 105 and the printing assembly 189 can be swung outwardly as shown in phantom outline at 194 in FIG. 4. This facilitates servicing of the apparatus and access to the card on or at the drum 89. As shown in dotted lines at 195 in FIG. 11. the printing mechanism 196 is detachable as a unit from the assembly 189. The printing mechanism is supported by a frame structure 198 having plates 199 and 200 cross tied together by rods 201. 202, 203 and 204. The printing mechanism 196 has a mounting frame 206 pivotally mounted on rod 202. A bias spring 207 urges the frame 206 to its open position. A screw 208 retains the frame 206 in its active position shown in FIG. 11 against the bias of the spring 207. A motor 209 is mounted on the frame 206. The motor 209. when energized. drives a shaft 212 which has a flexible coupling 213 attached thereto in a stepped manner. The flexible coupling 213 links the motor shaft 212 to a printing head 214 shown in FIGS. 11 to 13. The flexible coupling 213 isolates the printing head 214 from pulsating motions which the motor shaft 212 executes at the end of a stepping operation. To this end. the flexible coupling 213 has buffer springs 216 which resiliently interconnect the coupling members 217 and 218. A set screw 219 attaches the coupling member 217 to the motor shaft 212. The coupling part 218 forms a collar which conically blends into a ring 221 which has a plurality of notches 222, the number of which corresponds to the number of desired angular positions of the printing head. At least one detent 224 is biased by a spring 225 into the notches 222. In this manner. the motor 209 is capable of stepping the printing head to any desired angular position. However. pulsating motions of the motor shaft 212 are not transmitted to the printing head. Rather. the detent 224 cooperating with notches 222 will retain the printing head stationary in any stepped position. while the coupling 213 with its buffer springs 216 will absorb motor shaft pulsations. The printing head 214 has a plurality of flexible arms 226 projecting radially from a base 227. The base 227 is attached to the notched ring 221 and thus to the coupling piece or collar 218. Each flexible arm 226 of the printing head has a flat tab at its extremity. The tabs 228 may be rectangular as shown in FIG. 13. The tabs 228 of the printing head carry raised alphanumeric or clear text characters 229 or raised code text or encoded characters 231 in such an arrangement that an encoded character is located at a position 232 when ever its corresponding alphanumeric character is located at a position 233. In this manner. it is possible to print clear text and its corresponding encoded text simultaneously on a card 23 at different locations thereof. In particular. the printer according to the illus trated preferred embodiment is capable of printing information in clear text in either of the record parts 31 and 38 and simultaneously in code text in the record part 32 shown in FIG. 1. To this end. the printer has two hammers 234 and 235 which are simultaneously struck by two actuators 236 and 237 which are simultaneously actuated by a common magnetic armature 238. As shown in FIG. 14. the armature 238 is pivoted relative to a bracket 239 by pins 241. Each of the hammers is biased to a retracted position by a spring 243 located in a relatively stationary housing 244. In order to print corresponding alphanumeric and encoded characters. an electromagnetic coil or solenoid 246 is energized to attract the armature 38. This causes the actuators 236 and 237 to actuate the hammers 234 and 235 simultaneously. whereby these hammers simultaneously strike the tabs 228 which contain raised forms of the particular alphanumeric character and its encoded counterpart. Ink for the printing process is derived from a ribbon 248 which is interposed between the printing head tabs 228 and the card 23 on the drum 89 at the locations 232 and 233 shown in FIG. 12. The ribbon 248 is dispensed from a cartridge 249 which contains a supply of the ribbon. A ribbon guide 251 has a guide portion 252 projecb ing under the ribbon 248 (see FIGS. 11, 12 and 15). As seen in FIG. 12, the guide portion 252 has cutouts 254 to clear the printing tabs 228 and arms 226 at the locations 232 and 233. The ribbon 248 can be inserted or exchanged when the screw 208 has been loosened whereby the Spring 207 swings the assembly 196 outwardly about the pivot 202 (see FIG. 11). The printing mechanism 189 can be moved laterally on its supporting rod as shown in dotted lines at 291 in FIG. 2. so that different columns can be printed on the record cards. As seen in FIGS. 3 and 8. the drum 89 has an arm 292 which contacts a stop 293 on the frame structure 44 when the drum 89 has returned to its initial position after completion of the printing operation. As shown in FIG. 9.. a hold down spring 295 may be provided to positively retain the card 23 as it is wrapped around the drum 89. FIG. 9 also shows a readout head structure 296 which may be provided to read information from the card 23 at or in the vicinity of the drum 89. This would be in keeping with the broad scope of the subject invention. which contemplates printing. reading and/or the performance of another function or functions relative to the cards 23 in the region of the drum 89. Now that an understanding concerning the illustrated preferred embodiment of the invention has been gained. it may be helpful to summarize the function of the illustrated apparatus in terms of the subject invention. To this end it will be recognized that each card 23 is placed in a first region of the apparatus 28 at the platform 56. The card 23 is then advanced with the aid of the unidirectional card advancing device 8| from the first region at the platform 56 by way ofa first path 85 to a second region of the apparatus which is occupied by the drum 89. During such movement of the card. a first edge portion of the card leads an opposite second edge portion of the card and. as shown in FIG. 9. is inserted into the drum recess 88. In the illustrated preferred embodiment of the invention the advance card is wrapped around the drum 89 which is rotated in the direction of the arrow 101 as described above in connection with FIGS. 4 and 9. The card having been completely wrapped around the drum 89. the direction of rotation of that drum is reversed and then proceeds in the direction of the arrow I6l shown in FIG. 10. The desired function relative to the card. such as printing and/or reading, may be performed at that juncture in the second region of the apparatus occupied by the drum 89. Reverse rotation of the drum 89 in the direction of the arrow 16! makes the aforesaid second edge portion of the card (the previously trailing edge) lead the above mentioned first edge portion (the previously leading edge As seen in FIG. 10, this now leading second edge portion is diverted by the spring 87 into the return path or channel 162. This second path 162 is different from the above mentioned first path 85 and leads from the second region occupied by the drum 89 back to the first region of the apparatus occupied by the two compartments which contain the unidirectional card advancing device 81 and the unidirectional card returning device I71, respectively, as shown in FIG. 4. The unidirectional card returning device will complete the return of the card to the mentioned first region when the slide block 123 is returned to its initial position shown in FIG. 3, whereby the mentioned second edge portion of the card continues to lead the above mentioned first edge portion. According to the illustrated preferred embodiment of the invention, the above mentioned first region is compartmentalized; a first compartment being defined by the platform 56 in the area occupied by the card advancing device 81, and a second compartment being defined by the lower platform 169 in the area occupied by the unidirectional card returning device 171. The card advancing device 81 first advances the card from the mentioned first compartment by way of the path 85 leading to the second region occupied by the drum 89. Performance of the desired function or functions relative to the card in the second region proceed as before The card is then moved by way of the return path 162 to the second compartment at the lower platform I69 with the aid of the spring 87, drum 89 and unidirectional card returning device I7]. As indicated at 23' in FIG. 4, the cards 23 may be placed in the first compartment of the first region of the apparatus in the form of a stack of cards. Only a small fraction of the stack of cards is shown in FIG. 4 so as to avoid obscurement of important features of the illustrated apparatus. In reality, the stack of cards is readily inserted through the slot 42 and input channel 45 in between the platform 56 and unidirectional card advancing device 8]. No substantial resistance is put up by the device 8I against such insertion, since the entering stack of cards will contact the low-friction portion 83 of the device 81. The unidirectional card advancing device 8] will advance the cards one by one from the stack 23' in the first compartment since the high-friction portion 82 of the device 8] will rotate into force-transmitting engagement with each successive top card of the stack during each forward stroke of the device 8]. On the other hand. the low-friction portion 83 of the device 81 will rotate into contact with each succeeding top card of the stack 23 during each return stroke of the device 81. In this manner, the card will not be shifted during the successive return strokes of the device 81. On the other hand, the cards will be advanced one by one from the stack 23' during successive forward strokes of the device 8], and will be thus advanced by way of the path 85 to the above mentioned second region occupied by the drum 89. As before, a first edge portion of each card leads an opposite second edge portion of that card during advancement to the second region. The desired function, such as printing and/or reading, is performed on each card in the second region while wrapped around the drum 89. The second or previously trailing edge portion of the particular card is then made to lead the previously leading or first edge portion of that card by rotating the drum in the direction of the arrow 16] shown in FIG. I0. As a feature of the illustrated preferred embodiment of the invention. each card is moved from the second region occupied by the drum 89 to the second compartment below the platform I69 before the function in the second region is performed relative to the next card in the stack. In other words. the card 23 shown in FIG. 10 is removed from the drum via the return channel I62 before the next card is advanced onto the drum via the upper channel 85. The cards are successively returned from the second region at the drum 89 by way of the lower path 162 and with the aid of the unidirectional card returning device 17]. Each returning card is engaged by the high-friction portion 176 of the device 171 which thereupon travels from the above mentioned advanced position to the initial position shown in FIG. 4. In this manner. the cards are stacked onto each other in the second compartment below the platform 169, as partially illustrated at 23". Whenever the device I7I is advanced from the initial position shown in FIG. 4 to the previously mentioned advanced position, the low-friction portion 177 will be rotated into contact with the underlying card. whereby the cards in the stack 23" will not be shifted relative to each other. At the end of a complete operation. the stack of cards 23" may be removed from the lower second compartment through the slot 42. No substantial resistance to such removal will be put up by the device 17], since the low-friction portion I77 will then have been rotated into contact with the underlying card as the stack is manually pulled to the right as seen in FIG. 4. As a special feature of the illustrated preferred embodiment of the invention. each card is first moved in the mentioned second region in a first direction away from the first path 85 by rotation of the drum 89 in the direction of the arrow 101 shown in FIGS. 4 and 9, and is then moved in such second region in a second direction opposite to the first direction to the second or return path 162 by rotation of the drum 89 in the direction of the arrow 16] as shown in FIG. 10 and described above. Owing to these features, the above mentioned objects of the invention are all met in an economical and reliable manner, whereby very heavy and complex equipment is avoided. as are a jamming and misprinting or misreading of cards. The subject extensive disclosure will suggest or render apparent various modifications and variations within the spirit and scope of the invention to those skilled in the art. As a special feature of the illustrated preferred embodiment, all cards will be stacked in the same order at 23" as they had been positioned at 23'. In this manner, the cards may be processed through the apparatus 28 two or more times in proper sequence, such as for a reading of different utility meters for the same households. Suitable electronic equipment for the portable billing apparatus 28 will now be described with the aid of the last figure of the drawings. Function and purpose of this electronic equipment are essentially as follows: To enable the photoelectric or magnetic reader 296 to read from each card 23 the information provided thereon by the utility computer 13 and printer 22, to enable the meter reader to input his readings into the portable billing apparatus by means of a keyboard 300, to calculate the new amount due on the basis of the billing information read from the card and the new meter reading supplied through the keyboard 300, to release the ratchet wheel 156 in a controlled manner for a stepped advancement of each card during the printing phase, to actuate the printing head 214 for a printing of the new meter reading and the new amount due on the cards 23 as mentioned above, and to actuate the printing hammers 246 during such printing process. The heart of the electronic equipment of the portable billing apparatus is a microcomputer 302. Microcomputers have become well-known in recent years as they form the essential part of hand-held or other portable electronic calculating equipment and have found utility in other areas where small computers are of advantage. By way of example, and not by way of limitation, the microcomputer 302 may be adapted from the commercially available MCS-4 Microcomputer. Alternatives are apparent to an integrated circuit designer of average skill from the subject disclosure. In particular, the microcomputer 302 has a two phase oscillator 304 which clocks a central processing unit (CPU) 305. A data bus 306 leads to and from the central processing unit 305. Random access memories (RAM) 308 and 309 are connected to the central processing unit 305 via data bus 306. Programed read only memories 310 and 311 are connectable to the central processing unit 305 via data bus 306 and an address latch 312. A chip selector 313 enables the address latch 312 to select one out of n programed read only memories which, in actuality, are preferably present in the form of integrated circuit chips. wherein n is the number of programed read only memories. An input/output interface device 316 selectively connects input ports (IP), 317, 318 and 319 and output ports (OP) 320 and 321 to the central processing unit 305 via data bus 306. For this purpose, the interface device 316 in conjunction with the chip selector 313 provides an input command via a line 323 to the input ports 317 to 319, and an output command via a line 324 to the output ports 320 and 321. The item 296 is preferably a code reader which, for instance, reads the billing information from the part 32 of the card as provided by the utility computer and printer. The signals produced by the reader 296 are amplified and processed by a signal processor 331 which may be of a basically conventional type. A line 332 applies the amplified and processed read message to the input port 317 whence it is applied to the central processing unit 305 by the interface device 316 and data bus 306. The RAM device 309 is preferably of a conventional integrated circuit design having an output port 362 in addition to a read/write memory 364. The meter reader inputs the reading for the particular customer through the keyboard 300 which has digit keys (1 through 9), a decimal key (0), an entry key (E) and a clear key (C). The keyboard device 300 is preferably of a coordinate or cross-bar type receiving its input via a line 334 and output port 362 of the integrated RAM device 309 and supplying its output via a line 335 to the input port 319. The data provided by the keyboard device 300 is supplied via the interface device 316 and data bus 306 to the central processing unit 305 where it is processed together with the billing information read by the reader 296. Such processing is effected under the control of the programed read only memories 310 and 311. Accordingly, information which applies to customers in general may be stored in the program of the read only memories thereby saving space on the cards 23 and additional reading steps. The RAM device 308 is preferably of a conventional integrated circuit design having an output port 361 in addition to a read/write memory 363. As the microcomputer 302 has completed a calculating operation and is ready for the printing process, a driver 341 is energized via a line 342 and the output port 361 of the integrated RAM device 308. The driver 341 may be of a conventional type which alternatively energizes the electromagnets 184 and 185 in order to actuate the pawl into controlling a stepped advance of the ratchet wheel 156 and thereby of the card wrapped on the drum 89. Information on the data to be printed is supplied via the output port 320 and a line 344 to a driver 345. The driver 345 may be of a conventional type which energizes the stepping motor 209 with electrical pulses so that the rotary printing head 214 is actuated to the correct angular position for the printing of each clear text and corresponding code text character. In order to permit the equipment to orient itself as to the position of the printing head 214, an angular head position sensor 347 is provided. The sensor 347 may be of an electrooptical, electromagnetic or other conventional type to sense the actual angular position of the printing head 214. A line 349 applies the position sensin g signal to the input port 318 for consideration by the 17 central processing unit 305 in its control of the printing head. Whenever the printing head 214 has been actuated to the desired angular printing position. the microcomputer 302 energizes the hammer actuator 246 via the output port 321 and a line 351. Movement of the printing mechanism for printing in different columns on the card 31., if needed may be controlled in a similar manner by the microcomputer 302 so that no specific equipment is disclosed for this purpose. Rather, the figure under discussion discloses electronic equipment which will satisfy the basic data processing and control needs of the portable billing apparatus 28. Refinements for particular billing situations may be added on the basis of conventional circuit design. We claim: 1. In a method of performing a function relative to a card, the improvement comprising in combination the steps of: placing said card in a first region; advancing said card from said first region by way of a first path to a second region, whereby a first edge portion of the card leads an opposite second edge portion of the card; performing said function relative to said card in said second region; providing a second path difi'erent from said first path and leading from said second region to said first region, and locating said second path between said first path and said second region; making said second edge portion lead said first edge portion of the card; depressing said leading second edge portion into said second path; and returning said card from said second region to said first region by way of said second path difi'erent from said first path with said second edge portion continuing to lead said first edge portion of the card. 2. A method as claimed in claim 1, wherein: said first region is compartmentalized; said card is positioned in a first compartment in said first region; said card is advanced from said first compartment in said first region by way of a first path leading from said first compartment to said second region; and said card is moved from said second region to a second compartment in said first region by way of a second path leading from said second region to said second compartment in said first region. 3. A method as claimed in claim 2, wherein: said card is first moved in said second region in a first direction away from said first path and is then moved in said second region in a second direction opposite to said first direction to said second path. 4. A method as claimed in claim 2, wherein: said card is first rotated in said second region in a first sense away from said first path and is then rotated in said second region in a second sense toward said second path. 5. In a method of performing a function relative to a number of cards. the improvement comprising in com- 6 bination the steps of: placing said cards in the form of a stack of cards in a first compartment of a first region; advancing said cards one by one from said stack of cards in said first compartment to a second region by way of a first path leading from said first com partment to said second region. whereby a first edge portion of each card leads an opposite second edge portion of that card; performing said function relative to each card in said second region; providing a second path different from said first path and leading from said second region to said first region, and locating said second path between said first path and said second region; and making said second edge portion of each card lead said first edge portion of that card and moving each card from said second region to a second compartment in said first region before said function is performed relative to the next card in said stack. the cards being moved from said second region to said second compartment in said first region by depressing said leading second edge portion of each card into said second path and advancing each card by way of said second path, the latter advanced cards being stacked in said second compartment in said first region. 6. A method as claimed in claim 5, wherein: each card is first moved in said second region in a first direction away from said first path and is then moved in said second region in a second direction opposite to said first direction to said second path. 7. A method as claimed in claim 5, wherein: each card is first rotated in said second region in a first sense away from said first path and is then rotated in said second region in a second sense toward said second path. 8. In apparatus for performing a function relative to a card. the improvement comprising in combination: means for storing said card in a first region of said apparatus; means defining a first channel between said first region and a second region of said apparatus; means for advancing said card from said first region by way of said first channel to said second region, whereby a first edge portion of the card leads an opposite second edge portion of the card; means for performing said function relative to said card in said second region; means defining a second channel extending between said second region and said first region and being located between said first channel and said second region; means for reversing the direction of movement of said card whereby said second edge portion leads said first edge portion; and means for depressing said leading second edge portion into said second channel, said reversing means including means for returning said card from said second region to said first region at said reversed direction of movement and by way of said second channel. 9. Apparatus as claimed in claim 8, wherein: said apparatus includes means for defining distinct first and second compartments in said first region; said storing means include means for storing said card in said first compartment; said first channel defining means include means for defining said first channel between said first compartment and said second region; said card advancing means including means for advancing said card from said first compartment by way of said first channel to said second region: said second channel defining means include means for defining said second channel between said second region and said second compartment; and said card returning means include means for returning said card from said second region to said second compartment by way of said second channel. 10. Apparatus as claimed in claim 9, including: means for moving said card in said second compartment from said second channel to a rest position in said second compartment spaced from said first compartment. 11. Apparatus as claimed in claim 9, including: means in said second region for moving said card. said moving means including means for first moving said card in said second region in a first direction away from said first channel and means for then moving said card in said second region in a second direction opposite to said first direction and toward said second channel. 12. Apparatus as claimed in claim 9, including: rotary means in said second region; means for wrapping said card about said rotary means in said second region: and means for rotating said rotary means with said card in said second region. said rotating means including means for rotating said rotary means with said card in a first sense away from said first channel. and means for rotating said rotary means with said card alternatively in a second sense toward said second channel. 13. In apparatus for performing a function relative to a number of cards. the improvement comprising in combination: means for defining a first compartment; means for receiving said cards in the form of a stack of cards in said first compartment: means for providing a first channel between said first compartment and a predetermined region of said apparatus: means for advancing said cards one by one from said stack of cards in said first compartment to said predetermined region by way of said first channel. whereby a first edge portion of each card leads an opposite second edge portion of that card; means for performing said function relative to each card in said predetermined region: means for defining a second compartment: means for providing a second channel extending between said predetermined region and said second compartment and being located between said first channel and said predetermined region: means for reversing the direction of movement of each card in said predetermined region whereby said second edge portion of each card leads said first edge portion of that card: and means for depressing said leading second edge portion of each card into said second channel. said reversing means include means for moving each card from said predetermined region to said second compartment before said function is perfomied relative to the nest card in said stack. and for so moving each card in said reversed direction of movement from said predetermined region to said second compartment by way of said second channel; and means for stacking said moved cards in said second compartment. 14. An apparatus as claimed in claim 13. including: means in said predetermined region for moving said card. said moving means including means for first moving said card in said predetermined region in a first direction away from said first channel and means for then moving said card in said predetermined region in a second direction opposite to said first direction and toward said second channel. 15. An apparatus as claimed in claim 13, including: rotary means in said predetermined region; means for wrapping said card about said rotary means in said predetermined region: and means for rotating said rotary means with said card in said predetermined region. said rotating means including means for rotating said rotary means with said card in a first sense away from said first channel. and means for rotating said rotary means with said card alternatively in a second sense toward said second channel. 16. in apparatus for performing a function relative to card. the improvement comprising in combination: means for storing said card in a first region of said apparatus: means defining a first channel between said first region and a second region of said apparatus; means defining a second channel extending between said second region and said first region and being located between said first channel and said second region: means for advancing said card from said first region by way of said first channel to said second region. whereby a first edge portion of the card leads an opposite second edge portion of the card; means in said second region for moving said card in a first direction wherein said first edge portion leads said second edge portion. and alternatively in a second direction wherein said second edge portion leads said first edge portion; means for performing said function relative to said card in said second region; means at said second region for positioning said leading first edge portion of said card into engagement with said card moving means in said second region and for alternatively depressing said leading second edge portion of said card into said second channel; and means for returning said card from said second region to said first region by way of said second channel with said second end portion leading said returning card through said second channel. 17. An apparatus as claimed in claim 16. wherein: said card moving means in said second region include rotary means. means for wrapping said card about said rotary means in said second region. and means for rotating said rotary means with said card in said second region. said rotating means including means for rotating said rotary means with said card in a first sense away from said first channel. and means for rotating said rotary means with said card alternatively in a second sense toward said second channel: and said edge positioning and depressing means include means for positioning said leading first edge portion of said card into engagement with said rotary and wrapping means. and for alternatively depressing said leading second edge portion of said card into said second channel upon rotation of said rotary means with said card in said second sense toward said second channel. 1. In a method of performing a function relative to a card, the improvement comprising in combination the steps of: placing said card in a first region; advancing said card from said first region by way of a first path to a second region, whereby a first edge portion of the card leads an opposite second edge portion of the card; performing said function relative to said card in said second region; providing a second path different from said first path and leading from said second region to said first region, and locating said second path between said first path and said second region; making said second edge portion lead said first edge portion of the card; depressing said leading second edge portion into said second path; and returning said card from said second region to said first region by way of said second path different from said first path with said second edge portion continuing to lead said first edge portion of the card. 2. A method as claimed in claim 1, wherein: said first region is compartmentalized; said card is positioned in a first compartment in said first region; said card is advanced from said first compartment in said first region by way of a first path leading from said first compartment to said second region; and said card is moved from said second region to a second compartment in said first region by way of a second path leading from said second region to said second compartment in said first region. 3. A method as claimed in claim 2, wherein: said card is first moved in said second region in a first direction away from said first path and is then moved in said second region in a second direction opposite to said first direction to said second path. 4. A method as claimed in claim 2, wherein: said card is first rotated in said second region in a first sense away from said first path and is then rotated in said second region in a second sense toward said second path. 5. In a method of performing a function relative to a number of cards, the improvement comprising in combination the steps of: placing said cards in the form of a stack of cards in a first compartment of a first region; advancing said cards one by one from said stack of cards in said first compartment to a second region by way of a first path leading from said first compartment to said second region, whereby a first edge portion of each card leads an opposite second edge portion of that card; performing said function relative to each card in said second region; providing a second path different from said first path and leading from said second region to said first region, and locating said second path between said first path and said second region; and making said second edge portion of each card lead said first edge portion of that card and moving each card from said second region to a second compartment in said first region before said function is performed relative to the next card in said stack, the cards being moved from said second region to said second compartment in said first region by depressing said leading second edge portion of each card into said second path and advancing each card by way of said second path, the latter advanced cards being stacked in said second compartment in said first region. 6. A method as claimed in claim 5, wherein: each card is first moved in said second region in a first direction away from said first path and is then moved in said second region in a second direction opposite to said first direction to said second path. 7. A method as claimed in claim 5, wherein: each card is first rotated in said second region in a first sense away from said first path and is then rotated in said second region in a secOnd sense toward said second path. 8. In apparatus for performing a function relative to a card, the improvement comprising in combination: means for storing said card in a first region of said apparatus; means defining a first channel between said first region and a second region of said apparatus; means for advancing said card from said first region by way of said first channel to said second region, whereby a first edge portion of the card leads an opposite second edge portion of the card; means for performing said function relative to said card in said second region; means defining a second channel extending between said second region and said first region and being located between said first channel and said second region; means for reversing the direction of movement of said card whereby said second edge portion leads said first edge portion; and means for depressing said leading second edge portion into said second channel, said reversing means including means for returning said card from said second region to said first region at said reversed direction of movement and by way of said second channel. 9. Apparatus as claimed in claim 8, wherein: said apparatus includes means for defining distinct first and second compartments in said first region; said storing means include means for storing said card in said first compartment; said first channel defining means include means for defining said first channel between said first compartment and said second region; said card advancing means including means for advancing said card from said first compartment by way of said first channel to said second region; said second channel defining means include means for defining said second channel between said second region and said second compartment; and said card returning means include means for returning said card from said second region to said second compartment by way of said second channel. 10. Apparatus as claimed in claim 9, including: means for moving said card in said second compartment from said second channel to a rest position in said second compartment spaced from said first compartment. 11. Apparatus as claimed in claim 9, including: means in said second region for moving said card, said moving means including means for first moving said card in said second region in a first direction away from said first channel and means for then moving said card in said second region in a second direction opposite to said first direction and toward said second channel. 12. Apparatus as claimed in claim 9, including: rotary means in said second region; means for wrapping said card about said rotary means in said second region; and means for rotating said rotary means with said card in said second region, said rotating means including means for rotating said rotary means with said card in a first sense away from said first channel, and means for rotating said rotary means with said card alternatively in a second sense toward said second channel. 13. In apparatus for performing a function relative to a number of cards, the improvement comprising in combination: means for defining a first compartment; means for receiving said cards in the form of a stack of cards in said first compartment; means for providing a first channel between said first compartment and a predetermined region of said apparatus; means for advancing said cards one by one from said stack of cards in said first compartment to said predetermined region by way of said first channel, whereby a first edge portion of each card leads an opposite second edge portion of that card; means for performing said function relative to each card in said predetermined region; means for defining a second compartment; means for providing a second channel extending between said predetermined region and said second compartment and being located between said first channel and said pRedetermined region; means for reversing the direction of movement of each card in said predetermined region whereby said second edge portion of each card leads said first edge portion of that card; and means for depressing said leading second edge portion of each card into said second channel, said reversing means include means for moving each card from said predetermined region to said second compartment before said function is performed relative to the next card in said stack, and for so moving each card in said reversed direction of movement from said predetermined region to said second compartment by way of said second channel; and means for stacking said moved cards in said second compartment. 14. An apparatus as claimed in claim 13, including: means in said predetermined region for moving said card, said moving means including means for first moving said card in said predetermined region in a first direction away from said first channel and means for then moving said card in said predetermined region in a second direction opposite to said first direction and toward said second channel. 15. An apparatus as claimed in claim 13, including: rotary means in said predetermined region; means for wrapping said card about said rotary means in said predetermined region; and means for rotating said rotary means with said card in said predetermined region, said rotating means including means for rotating said rotary means with said card in a first sense away from said first channel, and means for rotating said rotary means with said card alternatively in a second sense toward said second channel. 16. In apparatus for performing a function relative to a card, the improvement comprising in combination: means for storing said card in a first region of said apparatus; means defining a first channel between said first region and a second region of said apparatus; means defining a second channel extending between said second region and said first region and being located between said first channel and said second region; means for advancing said card from said first region by way of said first channel to said second region, whereby a first edge portion of the card leads an opposite second edge portion of the card; means in said second region for moving said card in a first direction wherein said first edge portion leads said second edge portion, and alternatively in a second direction wherein said second edge portion leads said first edge portion; means for performing said function relative to said card in said second region; means at said second region for positioning said leading first edge portion of said card into engagement with said card moving means in said second region and for alternatively depressing said leading second edge portion of said card into said second channel; and means for returning said card from said second region to said first region by way of said second channel with said second end portion leading said returning card through said second channel. 17. An apparatus as claimed in claim 16, wherein: said card moving means in said second region include rotary means, means for wrapping said card about said rotary means in said second region, and means for rotating said rotary means with said card in said second region, said rotating means including means for rotating said rotary means with said card in a first sense away from said first channel, and means for rotating said rotary means with said card alternatively in a second sense toward said second channel; and said edge positioning and depressing means include means for positioning said leading first edge portion of said card into engagement with said rotary and wrapping means, and for alternatively depressing said leading second edge portion of said card into said second channel upon rotation of said rotary means with said card in said second sense toward said second channel.

1973-11-30

en

1975-08-19

US-51593974-A

Method of sterilizing using a rotary disk-ball valve control system ABSTRACT A plurality of valves, including ball valves, regulates the flow of a sterilizing agent to and from a sterilizing chamber. Rotary means connected to a ball valve regulates the flow of the sterilizing agent through the valve. Driving means cause the rotary means to rotate, thereby opening or closing the ball valve at predetermined times. A plurality of switches regulate the driving means, and circuit means connected to the switching means regulate the temperature and pressure in the chamber in timed relation with the driving means. Camming means coupled to the driving means operate the switching means in timed relation with the driving means. BACKGROUND OF THE INVENTION The present invention relates to a sterilizer system. More particularly the present invention relates to a ball valve sterilizer system and control. Various sterilizer systems which utilize steam as a sterilizing agent are known in the art. Typically, a steam sterilizer system is used in hospitals, chemical laboratories, biological laboratories and, in general, wherever materials must be sterilized. The present invention is not limited to sterilizer systems using steam only, it is applicable to all types of sterilizers, including gas sterilizers, low temperature sterilizers, washer sterilizers, and steam-vacuum sterilizers. For the purpose of conciseness, however, the invention is described herein in terms of a general purpose steam sterilizer. It should be understood, however, that the invention is equally applicable to sterilizers using other gases as the sterilizing agent. As used in a hospital, a sterilizer must be capable of sterilizing at least three different types of materials, namely, fabrics such as caps, gowns, and dressings; surgical instruments; and chemical solutions. The operation of a sterilizer using steam depends upon control of the flow of steam at high pressures and temperatures. In the past, sterilizers employed poppet valves to control the steam flow. It was found that the poppet valves used in a sterilizer became defective due to articles or impurities in the steam which interfered with proper seating of the valve face on the valve seat and due to corrosion by the steam. As a result, the flow of steam could not be reliably or accurately regulated. Moreover, due to the failure of the valve to properly regulate the flow of steam, the sterilizer failed to sterilize the article or matter to be sterilized. In many areas, and especially in hospital operating rooms, this could prove to be disastrous. BRIEF SUMMARY OF THE INVENTION A principal advantage of the present invention is that the flow of sterilizing agent is reliably and accurately regulated by ball valves and the problem of valve failure is substantially avoided. Another advantage of the present invention is that the valves are accurately, efficiently and reliably operated in synchronism with electrical control circuitry which determines the sequence of steps for sterilizing the matter to be sterilized. Another advantage of the present invention is that the rotation of the ball member of a ball valve provides a continuous wiping action which maintains the valve seating clean and free of corrosion. Unlike poppet valves, the ball valve is less subject to defects from particles or impurities in the steam and is also not as subject to corrosion when used with steam or gas sterilizing systems. Another advantage of the present invention is the means for rotating the ball valve member, which enables 360° rotation of the member. Full 360° rotation of the ball valve member is a significant advantage over prior art devices which are limited to 90° rotation, since a much cleaner wiping action is achieved. Another advantge of the present invention is that the means for rotating the ball valve member is economical. The present invention utilizes a mechanical arrangement of program disks for operating a plurality of ball valves whereas prior art devices required individual electromechanical means to move a ball valve member back and forth through a 90° arc. These electromechanical devices are expensive since the armature of the electromechanical device is required to provide a significant force. Briefly, in accordance with the present invention, matter, in the form of either solids or liquids, is sterilized by flowing a gaseous sterilizing agent such as steam at high temperatures into a sterilizing chamber. A plurality of valves, including ball valves, control the flow of the sterilizing agent to and from the sterilizing chamber. Each of the ball valves includes a housing and a ball valve member disposed within the housing and connected to a rotatable stem. The housing and valve member are provided with flow passages. Rotary means are mounted on the stem, and rotation of the rotary means opens and closes the ball valves by aligning the flow passages. Driving means rotate the rotary means to open and close the ball valves at predetermined times, and electrical switching means regulate the driving means. Circuit means connected to the switching means regulate the temperature and pressure of the sterilizing chamber in timed relation with the driving means, and camming means coupled to the driving means operate the switching means in timed relation with the driving means. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown. FIG. 1 is a view in side elevation of a sterilizing apparatus constructed in accordance with the principles of the present invention. FIG. 2 is a view, partly in cross-section, taken along line 2--2 in FIG. 1. FIG. 3 is a view, partly in cross-section, taken along line 3--3 in FIG. 1. FIG. 4 is a cross-sectional view of a ball valve taken along the line 4--4 in FIG. 1. FIG. 5 is a cross-sectional view of a ball valve taken along the line 5--5 of FIG. 4. FIGS. 6A and 6B comprise a decisional flow chart representing the operational states of an apparatus in accordance with the present invention. FIG. 7A and 7B comprise a schematic of an electrical circuit in accordance with the present invention. FIG. 8 is a piping diagram in accordance with the present invention. FIG. 9 is a chart showing the states of the microswitches of FIGS. 7A and 7B in relation to the operating cycles of an apparatus in accordance with the present invention. FIG. 10 is a chart showing the opening or closing of the ball valves according to the operating cycles of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings in detail, wherein like numerals indicate like elements, in FIGS. 6A and 6B there is shown a flow chart representing the sequence of decisions made during the operation of the present invention. The functions performed at each decisional block shown in FIGS. 6A and 6B correspond to the system components appearing in FIGS. 7A, 7B and 8. Accordingly, reference will be made to the latter figures in the course of describing the characteristic features of the invention as they are depicted in the flow charts in FIGS. 6A and 6B. The operation of the system begins by monitoring the steam pressure in the piping extending from a pressure source (not shown) to the apparatus. This is accomplished by a pressure-sensitive switch 34, shown in FIGS. 7A and 8. If the steam pressure exceeds a preselected threshold value, the pressure-sensitive switch 34 closes. This is indicated by the STEAM PRESSURE UP block. When switch 34 closes, it provides a current path to manual switches 108b, 110b, and 112b. Manual switches 108b, 110b and 112b determine the mode or cycle of operation of the invention, namely, the INSTRUMENTS, DRESSINGS or SOLUTION modes represented by the SELECT CYCLE block. The cycle of operation is selected by manually depressing one of the switches 108b, 110b and 112b. The selected cycle, however, will not begin until standby light 128 goes off. Standby light 128 remains on until the chamber door (not shown) is locked. With toggle switch 102 closed, power is applied to line 101a from power line 101. When the chamber door is open, switch 124a is closed and standby light 128 is on. Locking the chamber door opens switch 124a, de-energizing standby light 128. This is indicated by the blocks labeled LOCK DOOR and STANDBY LIGHT ON in FIG. 6A. Pressure-sensitive switch 34 determines when the apparatus enters an operating cycle. If the steam pressure in the piping connecting the steam source to the apparatus is above the preselected threshold, switch 34 closes, supplying power to switches 108b, 110b and 112b. If the steam pressure falls below the preselected threshold, however, the system will not operate, switch 34 remaining open. The STEAM PRESSURE UP block and switch 34 may both be omitted if the steam pressure source is reliable and pressure monitoring is not required. Also, the STEAM PRESSUE UP block may be omitted if it is preferred to monitor the steam pressure by a gauge such as the chamber jacket pressure gauge 45, see FIG. 8. Assuming that the steam pressure exceeds the preselected threshold, the apparatus is actuated by manually locking the chamber door and manually depressing one of switches 108b, 110b and 112b to select one of the three available cycles of operation. If both of the aformentioned conditions are met, that is, if the door is locked and a cycle of operation has been selected, the standby light 128 goes off and the apparatus begins to operate automatically following a fixed time delay. Closing the chamber door provides power to time delay relay 126 through switch 124, switch 34, switch 200 and either switch 108b, 110b or 112b. Time delay relay 126 controls the operation of contacts 127. This is represented in FIG. 6A by the block labeled 20 SECOND TIME DELAY. In the preferred embodiment shown, the duration of the delay interval is 20 seconds, that is, time delay relay 126 closes contacts 127 after a 20 second delay. However, it should be apparent that delay intervals of differing durations may be used without departing from the spirit or scope of the invention. At the termination of the delay period, time delay relay 126 closes contacts 127, providing current through switch 114a to motor 120. The operation of motor 120 is described in further detail in a later portion of this disclosure. Referring to FIG. 8, steam is admitted to chamber 54 and chamber jacket 50 through steam entry valve 44, which is a solenoid valve, until a temperature within a predetermined range of a preselected temperature (the "set point" temperature) is reached. Temperature controller and recorder 48 monitors the temperature of the steam in chamber 54 and opens and closes valve 44 in response. Steam flows through steam entry valve 44 to chamber 54 and chamber jacket 50 when valve 44 is open. Valve 44 is open when temperature-sensitive switch 104, in controller and recorder 48, closes. When terminals 106 and 134 are connected, current flows through switch 204 and light 130 is on. This segment of the system operation is represented by the parallel blocks labeled HEAT LIGHT ON and ADMIT STEAM. As steam flows through valve 44 into chamber 54 and jacket 50, the chamber temperature falls within a predetermined range of the set point temperature. At this time, switch 51 in controller and recorder 48 disconnects terminals 106 and 134 and connects terminals 106 and 132. With terminals 106 and 132 connected, current flows to sterilizer timer 136. This is indicated by the START STERILIZER TIMER block. When sterilizer timer 136 is activated, switch 140 closes and switch 142 opens. With switch 140 closed, current flows through terminals 106 and 132 to a serilizer light 138. This is indicated by the STERILIZER LIGHT ON block. With switch 142 open, no current can flow to switch 206. The operation of switch 206 in connection with the operation cycles of the apparatus is discussed in further detail hereinafter. While the sterilizer timer 136 is operating, temperature controller and recorder 48 regulates the temperature inside chamber 54. Specifically, as shown in the control loop containing the block marked TEMP. + 2° F. FROM SET POINT, if the temperature of chamber 54 is not more than 2° F. above the set point temperature, temperature sensitive switch 104 in controller and recorder 48 remains closed so that valve 44 remains open, admitting steam into chamber 54 and jacket 50. Should, however, the chamber temperature reach 2° F. above the set point temperature, temperature-sensitive switch 104 opens so that steam entry valve 44 closes preventing steam from entering chamber 54 and jacket 50. Once activated, sterilizer timer 136 runs continuously, whether valve 44 opens or closes, that is, whether or not switch 104 opens or closes. But if the chamber temperature falls to 2° F. below the set point temperature, sterilizer timer 136 stops running. When the chamber temperature falls to 2° F. below the set point temperature, switch 51 reconnects terminals 106 and 134 to reset sterilizer timer 136. The resetting operation is governed by the block marked TEMP. -2° F. FROM SET POINT. From the foregoing, it can be appreciated that the operation of the sterilizer timer 136 may be intermittent depending upon the chamber temperature. If the chamber temperature remains greater than 2° F. below the set point temperature and the sterilizer timer 136 measures one complete interval in the preferred embodiment without being reset, then motor 120 operates to cause ball valve 52 to close, see FIG. 8, thereby blocking the flow of steam from the source to chamber 54. This is indicated by the END OF STERILIZE TIME and CUT OFF STEAM blocks in FIG. 6A. The synchronous operation of ball valve 52 with motor 120 is described in detail hereinafter. After steam is cut off from chamber 54 and jacket 50, the step of exhausting the steam from chamber 54 commences. This step is monitored by ambient pressure switch 86 as explained hereinafter. During the exhaust step, an exhaust light 150 is illuminated and the steam is exhausted from chamber 54 and converted to water by water condensor 49. The rapidity with which the steam is exhausted from chamber 54 varies in accordance with the type of article being sterilized as indicated in the CYCLE DECISION I loop shown in FIG. 6B. Thus, if the cycle originally selected was for either instruments or dressings, chamber 54 is exhausted quickly by opening fast exhaust ball valve 60. On the other hand, if the cycle originally selected corresponded to solutions, the slow exhaust ball valve 62 is opened and chamber 54 is exhausted slowly. If the slow exhaust ball valve 62 is opened, chamber 54 is exhausted until ambient pressure is reached. At this point ambient pressure switch 86 closes to apply power to switch 212. Slow exhaust ball valve 62 is then closed in synchronous operation with motor 120, and it must be determined whether the apparatus should enter into a drying cycle. The synchronous operation of ball valve 62 with motor 120 is described in detail hereinafter. The drying cycle is used only if the article being sterilized is a fabric, surgical dressing, cap, gown, etc. As shown by the CYCLE DECISION II loop in FIG. 6B, a drying cycle will not be entered if the cycle originally selected was for either solutions or instruments. Assuming, however, that dressings are being sterilized, that is, that the drying cycle is entered by CYCLE DECISION II, and assuming further that fast exhaust ball valve 60 had been opened, fast exhaust ball valve 60 is maintained open as indicated by the block labeled (FAST EXHAUST STAYS OPEN). The drying timer 152 (see FIG. 7B), then, begins to measure the drying interval and drying light 154 is illuminated as indicated by the START DRYING TIMER and DRYING LIGHT ON blocks. In addition, ball valve 70 is opened when drying timer 152 is on so that steam ejector 66 starts operating, as indicated by the block labeled START STEAM EJECTOR. The steam ejector 66 receives the steam flowing through fast exhaust ball valve 60 and ejects it to condensor 49. The system continues to operate in this state without interruption until the termination of the drying interval, at which time ball valve 70 closes and steam ejector 66 is cut off. This is indicated by the block labeled CUT OFF STEAM EJECTOR. Whether or not the drying cycle has been used, if the fast exhaust ball valve 60 had been opened, it will remain open until the chamber door is unlocked. As indicated by the WARNING LIGHT ON block in FIG. 6B, at the time that fast exhaust ball valve 60 begins to close, the chamber door is locked so that current flows through switch 124 to warning light 172 and buzzer 174 which provide warning signals. In the preferred embodiment shown in FIG. 7B, the warning signal generated by buzzer 174 persists over a span of 2 minutes. It should be obvious, however, that other warning signals could be selected over differing intervals of time within the spirit and scope of the invention. The warning signals indicate that the sterilization process has been completed and that the chamber door may be unlocked. Unlocking the door opens switch 124 and terminates the warning signals, as indicated by the TWO MIN. BUZZER INTERRUPTED BY DOOR OPENING and the UNLOCK DOOR blocks. Referring now to FIG. 8, there is shown a piping diagram according to the present invention. Steam is supplied through a shut-off valve 36, a strainer 38 and a check valve 40 according to principles well-known in the art. The steam then passes through a pressure regulator 42, and the pressure of the steam is monitored by the pressure-sensitive switch 34. This portion of the apparatus corresponds to the decisional block labeled STEAM PRESSURE UP in FIG. 6A. The steam monitored by pressure-sensitive switch 34 passes through steam entry valve 44, which is a solenoid valve, and enters chamber 54, through ball valve 52, and chamber jacket 50. Steam entry valve 44 is shunted by manual by-pass valve 84. Valve 84 provides an alternate path for steam flow to ball valve 52 and chamber jacket 50 should there be an electrical malfunction in the system causing solenoid valve 44 to become inoperative. The steam in chamber jacket 50 flows to steam trap 46 and on to condensor 49. When a full flow of steam is attained, steam trap 46 closes to maintain jacket 50 hot. Valve 44 controls the flow of steam into chamber 54, through ball valve 52, as well as the flow into jacket 50. Valve 44 is, in turn, controlled by temperature controller and recorder 48. Temperature controller and recorder 48 records the temperature of chamber 54 throughout each cycle of operation, and it regulates the temperature of the steam in chamber 54 by monitoring the temperature in drain 56 and opening and closing valve 44 in response thereto. More specifically, the temperature controller and recorder 48 senses the temperature of the steam in drain 56. In response to the steam temperature inside drain 56, temperature controller and recorder 48 operates valve 44 to control the flow of steam into jacket 50 and chamber 54. Drain 56 is connected to steam trap 58 through check valve 57. Steam trap 58 maintains the temperature of the steam inside chamber 54 at the set point temperature by closing when chamber 54 is loaded with steam. Steam trap 58, then, maintains saturated steam in the piping between trap 58 and drain 56. Drain 56 is also connected to fast exhaust ball valve 60 through check valve 57. Fast exhaust ball valve 60 is connected to steam ejector 66, and steam flows from drain 56 to steam ejector 66 when fast exhaust valve 60 is open, that is, when instruments or dressings are being sterilized, see FIG. 6B. Further, drain 56 is connected to slow exhaust ball valve 62 through check valve 57. Slow exhaust ball valve 62 is connected to needle valve 64. Therefore, steam flows from drain 56 to needle valve 64 when slow exhaust valve 62 is open, that is, when a solution is being sterilized, see FIG. 6B. As shown in FIG. 8, steam traps 46 and 58, steam ejector 66, and needle valve 64 are connected to the inlet end of condensor 49. With fast exhaust ball valve 60 open, steam is exhausted from chamber 54 and ejected by steam ejector 66 to condensor 49. Steam flows through piping 68 and ball valve 70 to operate steam ejector 66. As the steam is exhausted from chamber 54 through ball valve 60, air is drawn into chamber 54 by way of piping 72 and air filter 74. The water supply for condensor 49 is regulated by valve 76 and water supply solenoid valve 78. In addition, a manual bypass valve 80 is shunted across solenoid valve 78 and a vacuum breaker 82 is connected to valve 78 between valve 76 and valve 78. In the event that the system suffers an electrical power failure, the steam entry valve 44 and water supply valve 78 would be rendered inoperative since they are electrically controlled solenoid valves. Therefore, manual bypass valves 84 and 80 are connected across valves 44 and 78, respectively, in oreder to provide alternative paths for the steam flow. The pressure of the steam entering chamber 54 through ball valve 52 is monitored by ambient pressure switch 86. Upon completion of the exhaust cycle, see the CYCLE DECISION I loop in FIG. 6B, the chamber pressure must reach ambient pressure before CYCLE DECISION II can be entered. This is characterized by the block designated AMBIENT PRESSURE in FIG. 6B. When the exhaust cycle has been completed, pressure switch 86 will indicate whether chamber 54 is at ambient pressure and, accordingly, whether CYCLE DECISION II can be entered. As previously explained, CYCLE DECISION II determines whether a drying cycle will be initiated. Steam ejector 66 is used only in the drying cycle. In other words, unless the article being sterilized is a dressing, ball valve 70 is closed and steam ejector 66 is not utilized. However, as shown in FIG. 6B, despite the fact that steam ejector 66 may not be operating, that is, despite the fact that the apparatus by-passes the drying cycle, the fast exhaust ball valve 60 will still be open. Referring now to FIGS. 7A and 7B, there is shown an electrical schematic for the present invention. Electrical power is supplied to recorder motor 100 in temperature controller and recorder 48 by means of power lines 101 and 103. Temperature sensitive switches 104 and 51, along with motor 100, are part of temperature controller and recorder 48. Temperature switch 104 is connected to solenoid valve 44, toggle switch 102 and microswitch 208. Switch 104 is actuated (opens) at the upper temperature limit (set point temperature + 2° F) while temperature switch 51 is actuated (opens) at the lower temperature limit (set point temperature -2° F). Push button switches 108, 110, and 112 determine the particular operating cycle for the system, namely, instruments, dressings or solutions, and push button switch 114 determines whether operation is manual or automatic. Specifically, switch 114 is mechanically coupled to switch 114a; so that when switch 114 closes, switch 114a opens. When depressed, switch 114 closes and provides a current path from line 101a to light 115. Additionally, depressing switch 114 causes switch 114a to open so that current cannot flow to motor 120. Thus, with switch 114 depressed, the apparatus must be operated manually. Lights 109, 111 and 113 are illuminated when switches 108, 110, and 112, respectively, are depressed. That is, with switches 108, 110 and 112 depressed, current flows to lights 109, 111 and 113, respectively. Microswitches 200, 204, 206, 208, 209, 210, 212, 214, 216, 218, 220, 222 and 224 are limit switches which are normally open and are operated by a top program disk 300 which is shown in FIGS. 1 and 2. For ease of reference, microswitches 200, 204, 206, 208, 209, 210, 212, 214, 216, 218, 220, 222 and 224 are designated in the aggregate by the letter M. Each of the microswitches M is closed during particular portions of the operating cycles (described in the flow charts appearing in FIGS. 6A and 6B) of the present systems. The on/off states of the microswitches M in relation to the program disk 300 and the operating cycles of the system are displayed in FIG. 9 and discussed in greater detail below. Microswitches M are controlled by means of top program disk 300. Disk 300 is provided with one or more arcuate slots, designated in the aggregate as 310, at varying radii from the disk center. Circular motion of disk 300 results in intermittent contact between the surface of disk 300 and microswitches M according to the locations and shapes of slots 310. In the automatic mode the disk 300 is driven by motor 120. If the motor 120 is not energized, as in the manual mode with switch 114a open, the disk 300 is rotated manually. The microswitches M control the operation of motor 120 as well as other functions of the apparatus, including the sterilization and drying cycles, as described below. In particular, all microswitches M connected to line 122 control the operation of motor 120, see FIGS. 7A and 7B. When the steam pressure is above the threshold value, pressure switch 34 closes and power is applied to microswitch 200. If microswitch 200 is closed, the power is applied to push-button switches 108b, 110b and 112b which are electrically connected to time delay relay 126. Push-button switches 108b, 110b, and 112b are mechanically coupled to push-button switches 108, 110 and 112 and to push-button switches 108a, 110a and 112a so that closing switch 108 closes switches 108a and 108b, closing switch 110 closes switch 110a and 110b and opens 110c, and closing switch 112 closes switches 112a and 112b and opens switch 112c. If operation is in the automatic mode, manual switch 114 is not depressed, and switch 114a provides a current path from either switch 108b, 110b or 112b to motor 120. Thus, in the automatic mode, motor 120 drives disk 300, and disk 300 controls the states of the microswitches M. Referring to FIG. 9, at 0° rotation of disk 300, microswitch 200 is closed. That is, the actuator arm (not shown) of switch 200 extends into an associated one of the slots 310, causing switch 200 to close. Switch 200 remains closed until disk 300 rotates past the 60° mark. At 60° rotation the actuator arm of switch 200 slidably engages the surface of disk 300, and switch 200 opens. Thus, a camming action between the surface of top program disk 300 and the actuator arm of each of the microswitches M controls the on/off state of the microswitch. As mentioned previously, door switch 124 is mechanically coupled to switch 124a so that closing switch 124 opens switch 124a, see FIG. 7B. Therefore, when the chamber door is closed, switch 124 closes and switch 124a opens. When switch 124a opens, standby light 128 goes off. This corresponds to the operation of the system represented by the block marked LOCK DOOR in FIG. 6A. With door switch 124, pressure switch 34, microswitch 200, and one of the push-button switches 108b, 110b and 112b closed, the time delay relay 126 is energized. After a 20 second time delay corresponding to the 20 SECOND TIME DELAY block in FIG. 6A, time delay relay 126 closes contacts 127, thereby energizing motor 120 if switch 114a is closed (automatic mode). After 60° rotation of program disk 300, microswitch 200 opens and motor 120 and program disk 300 stop. Initially, the chamber temperature is below the low temperature limit (set point temperature -2° F.) and temperature-sensitive switch 51 connects terminal 134 to terminal 106. Therefore, closed switch 204 energizes heat light 130. In particular, at 30° rotation of disk 300, microswitch 204 closes and heat light 130 goes on. Heat light 130 stays on until microswitch 204 opens at 70° rotation or switch 51 disconnects terminals 106 and 134. This corresponds to the HEAT LIGHT ON block in FIG. 6A. Between 0° and 60° of rotation, ball valve 52 is opened by the program disks 302 and 304, see FIGS. 1, 2, 3 and 10. The closing and opening of ball valves 52, 62, 60 and 70 in synchronism with the rotation of program disks 300, 302, and 304 is discussed in detail hereinafter. Ball valve 52, when open, admits steam to chamber 54 as indicated by the ADMIT STEAM block in FIG. 6A. Once the lower temperature limit, viz. 2° F. below the set point temperature, is reached the temperature sensitive switch 51 releases terminal 106 from contact with terminal 134 and connects terminal 106 with terminal 132. As a result, heat light 130 goes off and sterilizer timer 136 is actuated. This is indicated by the ACHIEVE SET POINT TEMP. and START STERILIZER TIMER blocks in FIG. 6A. When sterilizer timer 136 is actuated, switch 142 opens, switch 140 closes and sterilizer light 138 goes on as indicated by the STERILIZER LIGHT ON block. During sterilization, the chamber temperature is regulated by temperature controller and recorder 48. Temperature controller and recorder 48 includes temperature-sensitive switches 104 and 51 and recorder drive motor 100. If, for any reason, the chamber temperature falls below the lower temperature limit, viz. 2° F. below the set point temperature, temperature-sensitive switch 51 releases terminal 106 from contact with terminal 132 and reconnects terminal 106 to terminal 134. As a result, heat light 130 goes on while sterilizer time 136 is automatically reset due to the disconnection of power thereto. This is indicated by the TEMP. -2° F. FROM SET POINT and RESET TIMER blocks in FIG. 6A. Should, however, the lower temperature limit again be reached, switch 51 disconnects terminal 106 from terminal 134 and reconnects it to terminal 132 to re-energize sterilizer timer 136 which starts to measure a new timing cycle while steam enters chamber 54. When the chamber temperature is below the upper temperature limit, viz. 2° F above the set point temperature, switch 104 is closed. Microswitch 208 is closed from 0° to 90° rotation of disk 300 so that if switch 104 is closed at this time, solenoid valve 44 is opened and steam flows to chamber jacket 50 and ball valve 52 as indicated by the SOLENOID VALVE STAYS OPEN block. When the chamber temperature exceeds the upper temperatue limit, temperature-sensitive switch 104 opens causing solenoid valve 44 to close and shut off the flow of steam to jacket 50 and ball valve 52 as indicated by the CLOSE SOLENOID VALVE block. When the timing cycle measured by sterilizer timer 136 ends, switch 140 opens, sterilizer light 138 turns off, and switch 142 closes to provide a current path to microswitch 206. This corresponds to the END OF STERILIZE TIME block in FIG. 6A. Microswitch 206 is closed from 30° to 120° of rotation of program disk 300 so that power is transmitted to motor 120 at this time to advance it to the 120° position once the sterilizer timer cycle is over. When microswitch 206 opens at 120° rotation of the disk 300, it cuts off power to motor 120. The motor 120 will stop at this point unless power is supplied to it from an alternate current path. In the instruments or dressings mode of operation, however, push-button switch 108a or 110a is closed. In addition, from 90° to 175° rotation of disk 300 microswitch 210 is closed, see FIG. 9. Since microswitch 210 is closed from 90° to 175°, there is an alternate path of power to motor 120 through switch 108a or 110a and switch 210 when, at 120°, microswitch 206 opens. Further, microswitch 210 remains closed until disk 300 rotates to 175°. At 175°, in the instruments or dressing mode, fast exhaust valve 60 is open and switch 210 opens and cuts off power to motor 120. In the instruments or dressings mode, then, motor 120 must stop at 175° unless an alternate current path is provided to motor 120. At 90°, microswitch 209 closes, exhaust light 150 goes on, and the system enters CYCLE DECISION I in FIG. 6B. In the instruments and dressings modes, switches 112 and 112a are not depressed. In addition, in the instruments mode, switches 108 and 108a are depressed while switches 110 and 110a are not. Therefore, in the instruments mode, a current path is provided through switches 108a, 110c and 112c to microswitch 216. Microswitch 216, however, is open until 210° so that no current flows through switch 216 at 175°. Similarly, in the dressings mode, switch 110c is depressed so no current flows through switch 216 at 175°. Thus, in the instruments and dressings modes, the motor 120 is stopped at 175° while chamber 54 is exhausted of steam in the fast exhaust mode. This is indicated by the FAST EXHAUST VALVE OPEN block. When the chamber pressure drops to ambient pressure, however, pressure-sensitive switch 86 closes, and motor 120 is energized since microswitch 212 is closed at 175°, see FIG. 9. And switch 212 keeps motor 120 energized up to 220°. In comparison, if the solution mode is selected, no power flows through microswitch 210 despite the fact that it is closed from 90° to 175° rotation, since neither switches 108a nor 110a are depressed. At 70° rotation, as mentioned previously, switch 204 opens maintaining the heat light 130 off. At 90°, microswitch 209 closes, energizing exhaust light 150 and the system enters CYCLE DECISION I. Over the 120° interval of rotation extending from 90° to 210°, microswitch 209 remains closed and exhaust light 150 remains on. At 120°, switch 206 opens cutting off power to motor 120 unless an alternate current path to motor 120 is provided. While ball valve 52 remains open, steam is not permitted to enter chamber 54. This is caused by closing solenoid valve 44 when microswitch 208 is opened at 90° to 210°. Thus steam is slowly exhausted from jacket 50 through ball valve 52 to chamber 54. Slow exhaust valve 62 is open at 120° rotation of disk 300, as indicated by the SLOW EXHAUST VALVE OPEN block, and the motor 120 remains stopped at 120° rotation in the slow exhaust mode until ambient pressure is reached in chamber 54. When ambient pressure is reached, pressure sensitive switch 86 closes and power is supplied to motor 120 through switch 212. The motor 120 advances to 210°, and at 210° switch 216 closes keeping motor 120 energized since switch 112a is depressed in the solutions mode. At 220° switch 212 opens, but power is still supplied to motor 120 through switch 216. As disk 300 passes 210°, switch 209 opens and exhaust light 150 turns off. Meanwhile, microswitch 214 closes at 190° actuating drying timer 152 which closes switch 156, turning on drying light 154, and opens switch 170. In the instruments mode, motor 120 is energized up to 280° by means of switch 216, switch 112c, switch 110c and switch 108a. In the solutions mode, power is applied to motor 120 up to 280° by means of switch 112a and 216. Thus, in the instruments and solutions modes, the drying cycle is bypassed, see FIG. 6B, and motor 120 rotates straight through to 280°. In contrast, in the dressings mode, no power is applied to switch 216 through switch 110c so that when switch 212 opens at 220° no power is supplied to motor 120 unless an alternate current path to motor 120 is provided. As mentioned previously, switch 214 closes at 190°, actuating drying timer 152. Drying timer 152, when actuated, opens switch 170 so current cannot flow through switch 170 to switch 216. Motor 120, then, remains stopped at 220° in the dressings mode while the system runs through the drying cycle. Once drying timer 152 completes its cycle, it opens switch 156, which turns off drying light 154, and closes switch 170. Accordingly, power is transferred through switch 214 to switches 170 and 216 up to 280°. Motor 120 and disk 300, then, are driven to 280° rotation. At 270° microswitch 224 closes and, accordingly, warning light 172, time delay relay 173, and buzzer 174 go on. At the end of a predetermined interval, time delay relay 173 times out closing contacts 175, and buzzer 174 goes off. Warning light 172 stays on until switch 224 opens at 330°. From 90° to 275°, microswitch 222 closes so that solenoid valve 78 conducts water to condensor 49 during the exhaust and drying cycles. Since microswitch 218 is closed at 280° and switch 124a closes when the chamber door is opened, power is delivered to motor 120 as the door opens. The causes the motor 120 to drive the disks 300, 302 and 304 to their starting positions. Finally, microswitch 220 closes when disk 300 rotates past 310°. When closed, microswitch 220 operates latch relay 176, which is part of switches 108, 110, 112 and 114, so as to release switches 108, 110, 112 and 114 when switch 124a closes upon opening the chamber door. As indicated in FIG. 7B, however, this may also be accomplished by manually depressing reset switch 178 with the chamber door closed and cycling motor 120 through one revolution. Referring now to FIGS. 1 through 5 and 10, there is shown in detail the structure of the program disk 300 and the ball valves 52, 62, 60 and 70 of the present invention. In particular, in FIG. 1 there is shown a motor drive shaft 306 which is coupled to motor 120. Disks 300, 302 and 304 are mounted on shaft 306. Top program disk 300 contacts the plurality of microswitches 200, 204, 206, 208, 209, 210, 212, 214, 216, 218, 220, 222 and 224, previously described and designated in the aggregate as M. Immediately below top program disk 300 is middle program disk 302, and located beneath disk 302 is bottom program disk 304. Disks 302 and 304 are of equal diameters and are mounted concentrically on shaft 306. All of the disks may herein be referred to in the aggregate as disks 305. Disks 305 are variously joined near their edges by program posts 408, 410, 412, and 414. Top program disk 300 is also mounted concentrically on shaft 306. However, top disk 300 is of greater diameter than disks 302 and 304. Furthermore, as shown in FIG. 2, program disk 300 is provided with arcuate slots, designated generally as 310, at various angles and radii from the disk center which coincides with shaft 306. Disk 300 is joined to middle disk 302 by means of program posts 408 and 412. The top program disk 300 is provided with slots 310 of varying lengths and at different locations along the face of the disk to provide a camming surface to operate microswitches M. Slots 310 cooperate with microswitches M in a camming arrangement, switching certain of the microswitches M on and off at predetermined times. Thus, each of the microswitches M remains in the closed position for the duration of the time interval required by the disk 300 to traverse the length of the corresponding arcuate slot 310. That is, the actuator arm (not shown) of each of the switches M protrudes beneath the top surface of disk 300 and into an associated one of the slots 310 for a predetermined time period corresponding to the length of the slot 310, causing that switch to close during that time period. Upon traversing the entire length of the arcuate slot 310, the actuator arm is placed in sliding contact with the solid surface of disk 300. As the actuator arm slides over the surface of disk 300, the physical force exerted by disk 300 on the actuator arm causes the switch to open. Cast in other terms, each of the switches M follows the camming surface presented by revolving disk 300 and switches on and off accordingly. As disk 300 rotates through a full 360°, the system passes through each of the states set forth in the flow charts appearing in FIGS. 6A and 6B. Referring to FIG. 9, depending upon the length of each of the slots 310, each of the switches M remains closed for a fixed portion of a full revolution. Therefore, each of the microswitches M is on or off according to the portion of a full revolution traveled by disk 300. For example, microswitch 206 is closed from 30° to 120° or one-quarter of a full revolution of disk 300 and, accordingly, the length of the arcuate slot 310 which passes beneath microswitch 206 is 90° long. Similarly, microswitch 200 is open from 60° to 335° so that the length of the arcuate slot 310 which corresponds to microswitch 200 is 360° minus 275° or 85° long. Referring to FIG. 7A, it will be noted that motor 120 is alternately energized as previously described by a variety of the microswitches M which connect to wiring 122. In turn, the microswitches M are opened and closed by arcuate slots 310 so that the arcuate slots 310 control the synchronous energization of motor 120. To complete a full cycle of operation, the mechanical components shown in FIG. 8 must be synchronized with the electrical elements shown in FIGS. 7A and 7B. More specifically, the operation of the ball valves 52, 70, 62 and 60 must be synchronized with the movement of the arcuate slots 310 in disk 300, disk 300 being driven by motor 120. For this purpose, the assembly of disks 300, 302 and 304 is provided with a plurality of program posts 408, 410, 412, and 414, as shown in FIG. 3. The position of each of the program posts is designed to enable each of the ball valves to operate in synchronism with the operation of the microswitches M by slots 310. Program posts 408 and 412 join disks 300 and 302, see FIG. 1, and program 410 and 414 join disks 302 and 304. As shown in FIG. 3, each ball valve is mounted on a base 301 and located at a preselected position along the periphery of disks 300, 302 and 304. Focusing, for purposes of explanation, on ball valve 52, it will be noted that ball valve 52 is provided with paddle arms 400. The detailed structure of ball valve 52 is shown in FIG. 4. There, it is shown that ball valve 52 includes a ball valve member 504 which securely engages a stem 506. The stem 506 securely engages ball valve member 504 so that rotation of stem 506 about its own axis causes ball valve member 504 to rotate about the same axis. The ball valve member 504 is spherical in shape and is provided with a flow passage 508. Additionally, ball valve member 504 is housed within valve housing 505 which is provided with a flow passage 500. The ball valve member 504 is kept in position by annular seats 507 and 509 located at each end of flow passage 508, between the ball valve member 504 and the valve housing 505. Paddle arms 400 securely engage the stem 506 so that circular displacement of the paddle arms causes stem 506 to rotate about its own axis. Thus, stem 506 and the ball 504 are rotated by circular motion of the paddle arms 400 to bring flow passages 500 and 508 into and out of alignment. Ball valve assemblies are commonly provided with a stop post permitting only 90° of motion. This stop post has been removed in the present invention to permit stem 506 and ball valve 504 a full 360° rotation. By positioning the ball valves sufficiently close to the disks 300, 302 and 304 full 360° rotation of the ball valve member 504 is achieved when paddle arms 400, 402, 404 and 406--corresponding respectively to ball valves 52, 62, 60 and 70--are contacted by program posts 408, 410, 412, and 414. Furthermore, the relative position of each of the ball valves 52, 62, 60 and 70 with respect to the slots 310 determines the synchronous rotation of ball valve member 504 with the on/off states of microswitches M. The structure shown in FIG. 4 describes ball valves 62, 60 and 70 as well as ball valve 52. In the preferred embodiment shown in FIG. 1, ball valves 52 and 60 are provided with paddle arms 400 and 404 which extend into the space separating disks 302 and 304. On the other hand, ball valves 62 and 70 are provided with paddle arms 402 and 406 which are disposed at heights higher than the height of paddle arms 400 and 404. More specifically, paddle arms 402 and 406 extend into the space separating disks 300 and 302 rather than the space separating disks 302 and 304. Consequently, program posts 410 and 414, which do not enter the space between disks 300 and 302, do not control the operation of ball valves 62 and 70 since they cannot contact paddle arms 402 and 406 of those ball valves. On the other hand, program posts 408 and 412 serve to control the operation of the ball valves 62 and 70 since these program posts extend into the space separating disks 300 and 302. In other words, program posts 408 and 412 are capable of contacting the paddle arms 402 and 406 during the course of a full revolution of shaft 306 and disks 300, 302 and 304 mounted thereon. The synchronous relationship of the microswitches M and the ball valves 52, 62, 60 and 70 is disclosed in FIGS. 9 and 10. Thus, for example, as the drive shaft 306 begins to rotate, the actuator arm of microswitch 200 projects into the space provided by an associated arcuate slot 310. At this point, none of the ball valves 52, 62, 60 or 70 is open and the system is in the standby mode. As shaft 306 passes through 60° rotation, microswitch 200 traverses the entire length of the associated arcuate slot 310 and its actuator arm then slidably contacts the top surface of disk 300. Accordingly, microswitch 200 is switched to the off or open state by the solid surface of disk 300. Traveling from 0° to 60°, program post 410 contacts paddle arms 400 mounted on ball valve 52 bringing flow passages 500 and 508 into alignment. Consequently, ball valve 52 "opens". Further revolution of paddle arms 400 due to contact with program post 414 causes flow passages 500 and 508 to go out of alignment so that ball valve 52 "closes". That is, the opening and closing of ball valve 52 by means of contact between paddle arms 400 and program post 410 is gradual based on the gradual alignment of flow passages 500 and 508. Ball valves 62, 60 and 70 are opened and closed in an indentical manner. The gradual opening and closing of a ball valve is diagrammatically illustrated in FIG. 10 where solid lines indicate the gradual opening of a valve, dotted lines indicate the gradual closing of a valve, and hatched lines indicate that a valve is full open. Ball valve 52 is closed initially but opens as paddle arms 400 causes valve stem 506 and ball valve member 504 to rotate due to contact with program post 410. After nearly 60° of rotation of disks 305, paddle arms 400 are turned sufficiently to cause ball valve member 504 to align flow passages 508 and 500, as shown in FIGS. 4 and 5. FIGS. 4 and 5 show the extreme alignment (FIG. 4) and (FIG. 5) of flow passages 500 and 508. Alignment of flow passages 500 and 508 as shown in FIG. 4 permits the maximum flow of steam through a ball valve. Further rotation of the paddle arms 400, however, results in the rotation of stem 506 and ball valve member 504 so that flow passages 500 and 508 fall increasingly out of alignment. Consequently, the flow through ball valve 52 gradually decreases until, at nearly 180° rotation of disks 305, the steam flowing through the inlet end of flow passage 500 cannot enter flow passage 508. As shown in FIG. 10, it is possible for a ball valve to remain in the state of maximal alignment (FIG. 4) of flow passages 500 and 508 for finite periods of time. Thus, for example, ball valve 52 achieves maximum steam flow at 60° and retains that position until 120°, at which point the program post 414 rotates paddle arms 400 so that flow passages 500 and 508 fall increasingly out of alignment. In the preferred embodiment shown, the diameters of the flow passages 500 and 508 are such that the transition of the ball valve 52, 62, 60 or 70 from its "off" state (with no flow) to its "on" state (with maximal flow) requires approximately 60° rotation of the shaft 306. However, as will be obvious to one of ordinary skill in the art, the diameters of flow passages 500 and 508 may be varied to produce other intervals over which the valve turns completely on or off. Since the present invention is directed towards a method and apparatus for sterilizing articles such as instruments, dressings, and solutions it is important that the flow of steam -- upon which the sterilization process hinges -- be reliably and accurately regulated. For this purpose, valves 52, 70, 62 and 60 are all ball valves having the structure shown in FIGS. 4 and 5. The primary advantages of such a ball valve are that it is relatively free from the effects of particles and the corrosive effects of steam which are commonly found in other types of valves. In particular, the rotation of ball valve member 504 in valve housing 505 produces a wiping action which reduces or eliminates the effects of corrosion or foreign particles in the steam. This is a significant advantage over the use of poppet valves. In summary, sterilization of liquid or solid matter is accomplished by synchronizing the operation of ball valves 52, 70, 62 and 60 with the operation of microswitches M by means of relative motion between switches M and a program disk 300 and by means of the rotation of ball valve paddle arms 400, 402, 404 and 406 by pg,29 program posts 408, 410, 412, and 414. The program posts are fixed with respect to the program disks so that the operations of microswitches M and paddle arms 400, 402, 404 and 406 are synchronous. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention. We claim: 1. A method for sterilizing an article in a chamber operatively connected to a plurality of ball valves provided with rotary means for opening and closing said ball valves, comprising:programming a disc having a plurality of posts depending therefrom by providing said disc with a plurality of slots; rotating said programmed disc in slidable contact with a plurality of switches to cause said switches to open and close in a predetermined sequence determined by said slots and to cause said posts to contact said ball valve rotary means to open and close said ball valves in a predetermined sequence determined by said posts; admitting a gaseous sterilizing agent to said chamber; maintaining the temperature of said sterilizing agent in said chamber within a preselected range of a set point temperature for a predetermined interval of time; exhausting said sterilizing agent from the chamber and controlling the sequence and duration of said admitting, maintaining and exhausting steps in response to said predetermined sequence in which said switches are opened and closed and said posts contact said rotary means in response to said rotation of said programmed disc. 2. A method in accordance with claim 1 wherein said article is a dressing and including the step, following the exhausting step and carried out in said chamber, of drying said article of condensed moisture. 3. A method in accordance with claim 1 wherein said temperature maintaining step includes the steps of admitting said sterilizing agent to said chamber if said sterilizing agent temperature in said chamber drops below an upper temperature limit and preventing said sterilizing agent from entering said chamber if said sterilizing agent temperature in said chamber rises above said upper temperature limit, and selectively re-initiating said temperature maintaining step if said sterilizing agent drops below a lower temperature limit. 4. A method of sterilizing an article in a chamber operatively connected to a plurality of ball valves having rotary means for opening and closing said ball valves, comprising:providing a slotted disc having a plurality of posts depending therefrom in rotatable contact with one or more of said ball valve rotary means; providing an electric control circuit including a timer and a plurality of switches in slidable contact with said disc; rotating said slotted disc to cause said switches to operate said electrical control circuit in a predetermined sequence of states and to cause said posts to rotatably contact each of said ball valve rotary means to operate said ball valves in a predetermined sequence of states; admitting a gaseous sterilizing agent to said chamber by opening at least one of said ball valves; maintaining the temperature of said sterilizing agent in said chamber within a preselected range of a set point temperature for a predetermined interval of time determined by said timer; exhausting said sterilizing agent from said chamber and controlling the sequence and duration of said admitting, temperature maintaining, and exhausting steps according to the operation of said electrical control circuit and the operation of said ball valves in response to said rotating step. 5. A method in accordance with claim 1 wherein said article is a dressing and including the step, following the exhausting step and carried out in said chamber, of drying said article of condensed moisture. 6. A method in accordance with claim 4 wherein said temperature maintaining step includes the steps of admitting said sterilizing agent to said chamber if said sterilizing agent temperature in said chamber drops below an upper temperature limit and preventing said sterilizing agent from entering said chamber if said sterilizing agent temperature in said chamber rises above said upper temperature limit, and selectively re-initiating said temperature maintaining step if said sterilizing agent drops below a lower temperature limit.

1974-10-18

en

1977-01-18

US-15575498-A

Device for connecting two or more multiwire cables ABSTRACT The connecting device includes a drum (3) and two means (4) for securing wire bundles of the cables to be connected. Said securing means (4) are generally symmetrically positioned on either side of the drum (3), substantially coaxially therewith, and the drum (3) carries members for positioning the connection means at uniformly distributed locations adjacent its periphery. FIELD OF THE INVENTION The present invention generally relates to a device for connecting multiwire cables. BACKGROUND OF THE INVENTION Such devices are used to ensure join of cables disposed one after the other so as to connect two points of a line, even ones which are very remote. These devices are employed for all types of coaxial or optical cables, for example made of copper. The connecting device according to the invention is more particularly, but not exclusively, intended for connecting multiwire optical cables for which it is necessary to observe particular wiring rules due to the fragility of the optical fibers composing them, to the reserve of optical fibers, to the respect of the minimum radii of curvature, etc . . . . Multiwire cables are composed of a plurality of wires, copper wire or optical fiber for example, each transmitting information, data or current. The connection of two multiwire cables requires the connection of each wire of the upstream cable to a corresponding wire of the downstream cable. Such a connecting device may, in manner known per se, ensure connection of a plurality of cables disposed upstream to a plurality of cables disposed downstream, the total number of the wires presented upstream having to be equal to the total number of the wires presented downstream. The connection of these wires is effected by connection means of any type known per se, for example by a splice or a connector. SUMMARY OF THE INVENTION The connection of the optical cables is generally effected at the present time with the aid of devices comprising elements, called coiling cassettes, disposed side by side. Each coiling cassette ensures coiling and connection of one or more optical fibers of the optical cables upstream and downstream. The coiling cassettes are mounted to move in rotation about an axis in order to allow the user to displace them like the pages of a book to have access to the cassette containing the fiber or fibers on which he wishes to intervene. These devices are fastidious and slow to use since it is necessary upon each intervention to pivot the cassettes one by one to render the cassette containing the sought after fiber or fibers accessible. Moreover, these devices present the drawback of requiring the fibers to be cut to largely different lengths, varying as a function of the position of the cassette on which they are taken over. One can also cite document DE-A-3627599 which concerns a connection device for two high-voltage electrical cables, and the core of which is constituted by a plurality of wires. These wires are interconnected, without being separated or spaced apart, by means of a crimp connection. In contrast, the shielding wires of this cable are connected to each other individually by means of separate connectors. They are maintained in a separated apart and parallel position in relation to each other by support and spacing elements. In such a device, the conductive wires per se are connected by a central crimp connector, without any lateral spacing apart or separation. The invention proposes to overcome the different drawbacks of the known devices by providing a connecting device of reduced dimensions which is particularly easy to use. To that end, the invention relates to a device for connecting at least two multiwire cables, in which each wire of a cable disposed upstream is connected to a wire of a cable disposed downstream by a connecting means, for example a splice or a connector, characterized in that: it is composed of a drum and two means for securing the wire bundles of the cables to be connected, said securing means are positioned on either side of the drum overall in symmetrical manner and substantially on the same axis as said drum, the drum bears, at regularly distributed points near its periphery, means for positioning said connection means, these positioning means are mounted in rotation about the longitudinal axis of the drum, either by rotation means supporting this drum or by at least one ring mounted in rotation in relation to the drum, with the result that the wires maintained by the securing means and disposed in a connection means borne by the drum, form on either side of the drum two conical laps of wires having a securing means for focus, and that these connection means are accessible the one after the other by simple rotation of their positioning means about the axis of the drum, and that these connection means are accessible the one after the other by simple rotation of their positioning means about the longitudinal axis of the drum. The connecting device according to the invention is further noteworthy in that: the drum is cylindrical in shape, the drum has the general shape of a disc whose thickness is adapted to the dimensions of the connection means, the securing means are each constituted by a ring ensuring hold of the wires in a bundle, the securing means comprise a hub around which are disposed, side by side, the wires of the cable to be connected and a holding means retaining said wires in position around the hub, the holding means are constituted by two rings mounted to move in rotation around the hub, disposed against each other and each presenting a slot so that it is possible to insert the wires between the rings and the axial hub when the slots are aligned, while the withdrawal of said wires is avoided by rotating one of the rings with respect to the other to move the slots apart in the circumferential direction, the positioning means are notches made on the periphery of the drum, the securing means are positioned on a common hub which also bears the drum, for example constituted by a tube of constant diameter, the hub of each securing means is constituted by a conical element positioned with its end of larger diameter against the drum and bearing the wire-holding means at its end of smaller diameter, the hub bears fins between which the wires are disposed. DESCRIPTION OF THE DRAWINGS The invention will be more readily understood thanks to the following description given by way o-limiting example with reference to the accompanying drawings, in which: FIG. 1 is a schematic side view of an embodiment of a device according to the invention and comprises an enlarged view of a detail. FIG. 2 is a plan view of the device shown in FIG. 1. FIG. 3 is a view in perspective of a second embodiment of a device according to the invention. FIG. 4 is a view in perspective of a variant embodiment of a device of FIG. 3. FIGS. 5a and 5b show an embodiment of the holding means. FIG. 6 is a schematic view of a cable connection sleeve employing the device of FIG. 3. FIG. 7 is a schematic view of the sleeve of FIG. 6, with the cover removed. FIG. 8 is a side view of the sleeve of FIG. 6. FIGS. 9 to 13 show embodiments of the drum of the connecting device according to the invention intended for connecting conventional cables, namely, respectively, cables containing 128, 248, 496, 376 and 512 optical fibers. DETAILED DESCRIPTION OF THE INVENTION As shown in FIGS. 1 and 2, a connecting device allows the connection of an upstream cable 1 to a downstream cable 2 and is usually positioned in a connection sleeve schematically shown in FIG. 1 by the frame drawn in fine broken lines in which it is hermetically enclosed. In manner known per se, the connecting device may ensure connection of one or more cables disposed upstream to one or more cables disposed downstream, the total number of wires disposed upstream having to be equal to the number of wires disposed downstream. The device according to the invention may be employed for connecting multiwire cables of any type, made of copper, coaxial or optical. In manner known per se, the multiwire cables are composed of a plurality of wires. In the case of an optical cable, which we are considering by way of example in the present description, the optical fibers are either disposed in bundles of unitary fibers or of microsheaths within the sheath of the cable, or connected in bands in which two, four, six or eight fibers are disposed parallel to one another. For their connection, the cables 1 and 2 are flared out in unitary elements composed of individual fibers, microsheaths or bands depending on the type of cable used. By way of example, we shall consider in the present description the use of the device for connecting optical cables 1 and 2 formed by bands 10 and 20, these bands are a form of embodiment of the wires of a multiwire cable. The bands 10 and 20 released from the sheath of the cables are coiled on discs 11, 21 so as To have available a reserve of optical fibers with a view to possible modifications of the Connections. The connecting device according to the invention is composed of a drum 3 and two means 4 for securing the bundles of wires of the upstream cable and of the downstream cable, respectively. The drum 3 is cylindrical in form and presents a circular cross-section in the embodiment shown in the drawings. This drum has the general form of a disc whose thickness is adapted to the dimensions of the connection means employed, i.e. of the order of some centimeters. It may be constituted by a thick, solid or hollow disc, or by a ring. It may also be constituted by two plane faces disposed parallel to one another and connected by a ring of material whose diameter is equal to or smaller than the diameter of the two plane faces. Said securing means 4 are positioned on either side of the drum 3, overall symmetrically, being disposed substantially on the same axis as said drum 3. The bundle of bands 10, 20 issuing from the cables 1 and 2 are respectively positioned in one of the securing means 4. It is possible to use securing means 4 which are simply constituted by a ring ensuring hold of the bands in a bundle. Said securing means preferably comprise a hub 40 around which are disposed the bands of optical fibers side by side, and a holding means 5 retaining said bands in position around the hub. These holding means 5 may be constituted by fast-tightening rings, dismountable or not. The drum 3 bears, at regularly distributed points near its periphery, positioning means allowing positioning and hold of the bands 10 and 20 or connection means; these positioning means are not shown in FIGS. 1 and 2. By way of example, if the connection of optical fibers must be effected by a splice, a drum 3 presenting two outer plane faces whose diameter is larger than that of the ring which connects them, is used. The positioning means are in that case provided in each of the faces so as to retain the bands 10 and 20. These bands flare out so as to release the individual fibers on which splices are made in the space located between said plane faces. If the connection is to be effected with the aid of a connector, it is possible to use the same type of drum, with projecting plane faces bearing means for positioning the bands of fibers, the connectors being fixed to the ring, or to use a drum without projecting faces, on the periphery of which positioning means have been provided, ensuring hold of said connectors. Simple to make, these positioning means may be notches 30 made on the periphery of the drum. Any type of inscription, figure, letter or sign, may be printed near the notches on one and/or the other of the faces of the drum, so as to allow the wires to be located. When each band is to be positioned and held on the drum, V-notches of small opening are formed, at the bottom of which the bands may be wedged. When the positioning means must ensure positioning of connectors, the dimensions and shape of the notches 30 are adapted to the conformation of the connector. An embodiment of such a notch 30 intended for positioning a connector is shown in FIG. 3; this notch is of square cross-section. Such notches 30 are provided over a large part of the periphery of the drum. The bands 10, 20 held by the securing means 4 are disposed one by one in a notch of the drum 3 or in a connector borne by this drum. On doing so, a conical lap of bands having a securing means 4 for focus is produced on either side of the drum. It is, of course, possible to make the connection of the optical fibers before positioning the bands, or the connectors, in the positioning means of the drum. The connecting device according to the invention offers an easy access to the connections, as the latter are distributed over a circumference disposed around the axis on which the fibers are secured. This connecting device uses bands having virtually identical lengths, which avoids all the drawbacks due to the necessity of cutting the bands to different lengths as a function of the location in which their connection is made, such drawbacks being known with the devices employing coiling cassettes. According to an embodiment, not shown in the drawings, the securing means 4 are positioned on a common hub 40 which also bears the drum 3. A tube of constant diameter may constitute a simple form of embodiment of such a hub 40. FIG. 3 shows a variant embodiment in which the hubs of each securing means are constituted by a conical element 41, 42, each of these conical elements being positioned with its end of larger diameter against the drum 3 and bearing the band-holding means at its end of smaller diameter; only one holding means is shown in FIG. 3. The diameter of the end positioned against the drum of each conical element is, as shown in the drawing, smaller than the bottom diameter of the notches 30, so as to leave the necessary space for positioning the connectors around said conical elements. Such a form of embodiment makes it possible to limit the possibility of displacement of the bands in the direction of the axis of the device so as to reduce the risks of said bands breaking. In fact, if FIGS. 1 and 2 are considered again, it is seen that, near the securing means 4, the bands are close to one another, while they move away from one another as the drum is approached. Such spacing apart of the bands renders them vulnerable if, by accident, an object strikes them. The embodiment of the hub in two conical elements enables a device to be proposed in which the bands are always disposed at a short distance from a rigid surface. If by accident an object strikes or pushes a band, the deformation thereof is limited by its abutment against the wall of the hub and the rupture of this band is avoided. In the embodiment of FIG. 4, the hub bears fins (of which four have been shown on part 42) between which the bands 10, 20 are disposed. This form of embodiment allows an even better protection of the bands which are disposed inside the space defined by the fins and therefore inaccessible from the outside. It is, of course, possible to make similar fins on a common tubular hub. Such an embodiment of the common hub with a tubular inner body and triangular fins of which the upper part is against the drum 3, makes it possible to position each band in a fairly large volume to allow the formation of an additional reserve of band. In fact, it is possible to position the band loosely between the securing means 4 and the drum 3 or even to form one or more loops of bands which are disposed between the fins 44. This additional reserve allows the modification of the connection of the band at the level of the drum 3 without it being necessary to remove the band from the securing means and repositioning it after having displaced it in the direction of the drum. FIGS. 5a and 5b show a particularly simple and efficient embodiment of the holding means 5. This holding means 5 is constituted by two rings 51 and 52 mounted to move in rotation on the hub, disposed against each other and each presenting a slot 53, 54. When the rings are disposed as shown in FIGS. 3 and 5b, with the slots 53, 54 aligned, it is possible to insert the bands between the rings 51, 52 and the axial hub 40. When all the bands are inserted, it suffices, to prevent the withdrawal of said bands, to rotate one of the rings with respect to the other to move the slots 53, 54 apart in the circumferential direction, as shown in FIG. 5a. FIGS. 6 to 8 illustrate the use of a connecting device according to the invention in a cable connection sleeve 6. In this example, the cable connection sleeve is constituted by an overall parallelepipedic box presenting on each of its end faces four passages 60 for cables such as 62. The connecting device may thus be employed for connecting from one to four cables disposed upstream to one to tour cables disposed downstream. These Figures schematically show the arrangement of the bands in loops 61, making it possible to create fairly large reserves of bands without requiring the use of coiling discs such as the discs 21 and 11 of FIGS. 1 and 2. An embodiment of the different notches allowing positioning of the bands, or connectors, on the drum 3 is visible in FIG. 8. FIGS. 9 to 13 show embodiments of the drum 3 depending on the constitution of the cables for five conventional dimensions of the cables. These drums are shown in cylindrical connection sleeves 7. In these embodiments, the positioning means 30 are borne by one or more rings disposed on the periphery of the drum. The drum shown in FIG. 9 is intended for the connection of cables comprising 128 optical fibers distributed in 16 bands of 8 fibers. In this embodiment, the ring 31 occupies only a portion of the periphery of the drum, a space 38 remaining free and allowing passage of cables. The drum shown in FIG. 10 is intended for the connection of cables comprising 248 optical fibers distributed in 31 bands of 8 fibers, the drum bearing the ring 32 presenting 31 notches. The drum shown in FIG. 11 is intended for the connection of cables comprising 496 optical fibers distributed in 62 bands of 8 fibers. In this embodiment, the drum bears two rings 33 and 34 provided with notches 30. The bands are firstly positioned in the notches of the inner ring 33, positioning the notches of the ring 34 in register with those of the ring 33 as shown in the drawing. The ring 34 is then rotated so as to close the notches of the ring 33, then bands are positioned in the notches of this ring 34. The bands are then positioned on two conical laps while remaining easily accessible from the outside. The drum shown in FIG. 12 is a drum of the same structure as that of FIG. 10 but bears a ring 35 allowing the connection of cables comprising 376 optical fibers distributed in 47 bands of 8 fibers. The drum shown in FIG. 13 is intended for the connection of cables comprising 512 optical fibers distributed in 64 bands of 8 fibers. This drum is of the same type as that of FIG. 11 and comprises two rings 36, 37. The notches of the outer ring are closed at their inner end. The rings occupy only a portion of the circumference of the drum. It is then possible to remove the outer ring 37 by elastic deformation to position the bands in the notches of the ring 36, then to replace this ring 37 in order to position the bands in its notches. It will be noted that, in the device according to the invention, access to any connection between two wires is obtained very simply by rotating the drum about its axis, or by rotating the drum and the securing means, the bands being positioned loosely between the drum and said securing means or between said securing means and the ends of the sheaths of the cables. It is, of course, possible, in the case of the drum bearing a ring, to ensure a simple rotation of this ring with respect to the central part of the drum. The device according to the invention is also particularly interesting in that it offers the possibility of making the connections automatically with the aid of a machine on which the drum is driven in rotation step by step. Means for locating the position of the drum may be used to facilitate automatization. Although the drum of the device according to the invention has been described as being of circular cross-section, the present invention would not be exceeded by providing a drum of any cylindrical shape in the broad sense of the term, having any other cross-section, for example ellipsis, rhombus, etc. What is claimed is: 1. Device for connecting at least two multiwire cables (1, 2) in which each wire of a cable disposed upstream is connected to a wire of a cable disposed downstream by a connection means, characterized in that:it is composed of a drum (3) and two means (4) for securing the wire bundles of the cables to be connected, said securing means (4) are positioned on either side of the drum (3) overall in symmetrical manner and substantially on the same axis as said drum (3), the drum (3) bears, at regularly distributed points near its periphery, means (30) for positioning said connection means, these positioning means (30) are mounted to rotate about the longitudinal axis of the drum (3), either by rotation means supporting this drum (3), or by at least one ring (33, 34) mounted to rotate with respect to the drum (3),with the result that the wires maintained by the securing means (4) and disposed in a connection means borne by the drum (3), form on either side of the drum two conical laps of wires having a securing means (4) for focus, and these connection means are accessible one after the other by simple rotation of their positioning means (30) about the longitudinal axis of the drum (3). 2. Connecting device according to claim 1, characterized in that said securing means (4) comprise a hub (40) around which are disposed, side by side, the wires of the cable to be connected and a holding means (5) retaining said wires in position around the hub (40). 3. Connecting device according to claim 2, characterized in that the holding means (5) are constituted by two rings (51, 52) mounted to move in rotation on the hub, disposed against each other and each presenting a slot (53, 54) so that it is possible to insert the wires between the rings (51, 52) and the axial hub (40) when the slots (53, 54) are aligned, while the withdrawal of said wires is avoided by rotating one of the rings with respect to the other to move the slots (53, 54) apart in the circumferential direction. 4. Device according to claim 5, characterized in that the hub (40) of each securing means (4) is constituted by a conical element (41, 42) positioned with its end of larger diameter against the drum (3) and bearing the wire-holding means (5) at its end of smaller diameter. 5. Connecting device according to claim 1, characterized in that the securing means (4) are positioned on a common hub (40) which also bears the drum (3), for example constituted by a tube of constant diameter. 6. Connecting device according to claim 5, characterized in that the hub (40, 41, 42) bears fins (44) between which the wires are disposed. 7. Connecting device according to claim 1, characterized in that the positioning means (30) are notches made on the periphery of the drum. 8. Connecting device according to claim 1, characterized in that the drum (3) is cylindrical in shape. 9. Connecting device according to claim 1, characterized in that the drum (3) has the general shape of a disc whose thickness is adapted to the dimensions of the connection means. 10. Connecting device according to claim 1, characterized in that the securing means (4) are each constituted by a ring ensuring hold of the wires in a bundle. 11. A connecting device according to claim 1, wherein said connection means is one of a splice and a connector.

1997-04-02

en

2000-10-31

US-48870183-A

Multimicroprocessor system ABSTRACT A multimicroprocessor system constructed of multimicroprocessor structures each including N-number of microprocessor units, a shared memory, an input/output unit and a register exchange circuit. The microprocessor units are uniform and include a microprocessor, a data memory, a parallel input-output interface, a sequential input/output circuit, a program memory and a bi-directional buffer. The buffer connects the internal data bus in the microprocessor unit to the shared instruction bus for the multimicroprocessor structure, and the enable inputs of the buffer are connected to the internal busses for circuit selection in the microprocessor unit by the microprocessor address lines. The address lines of the first microprocessor unit in the multimicroprocessor structure are connected also to a shared memory, input/output unit and both to the parallel data exchange register circuit and the &#34;HALT&#34; inputs of the microprocessors in the rest of the units through a logic circuit, which serves to switch off the microprocessor units. The multimicroprocessor structures are connected therebetween by first level data exchange register circuits, whose control inputs are connected to the address lines of the first microprocessor units in the respective first microprocessor structures. These first level register circuits are connected groupwise to a second level data exchange register circuit, whose control input is connected to the address lines of the microprocessor unit whose address lines are connected to the first of the first level data exchange register circuits. BACKGROUND OF THE INVENTION This invention relates to a multimicroprocessor system of the single instruction stream and multiple data streams (SIMD) type as well as to a multimicroprocessor system of multiple SIMD systems (MSIMD) type, which can find application in parallel processing of information for various specific classes of problems, such as high-speed Fourier transformation, vector and matrix calculations, simultaneous real-time processing of signals from different sources, processing of data from physical or other experiments, simultaneous control of a number of interconnected objects, and rapid solution of differential and linear equations. The electronic calculator devices and computers of the above type run their programs with all their SIMD or MSIMD groups of microprocessor units executing one and the same instruction at a time over different operands. Upon execution of several instructions, an information exchange between the units takes place. SIMD and MSIMD microprocessor systems are known which comprise a control unit and executive microprocessor units specifically connected therebetween, in which all executive units are connected with the control unit through a single instruction line. A switching unit controlled by the control unit ensures the connection between said units by means of control lines for data exchange. All the units are connected through the switching unit to a common memory as well as to common data input/output circuits. The microprocessor units each comprise a microprocessor, a RAM-type memory and an input/output interface. Hierachically structured multimicroprocessor systems are known where the units are arranged in a tree. A disadvantage of the SIMD and MSIMD multimicroprocessor systems is their unfitness for implementation in universal, arbitrary microprocessor elements. Moreover, the control on such systems must be very complicated, which has an effect on the complexity of the control unit, which, in contrast to the other units, does not enable one to charge said unit with executive functions. The intermodular connection requires the availability of complex, specific circuits. The data exchange between the units is based on a sequential rather than a parallel principle thereby reducing the performance of the system as a whole. Such systems possess neither the flexibility required for extension (reconfiguration) by additional units nor the possibility for transformation from an SIMD into an MSIMD system and vice versa. SUMMARY OF THE INVENTION The object of this invention is to provide a multimicroprocessor system of SIMD and MSIMD type possessing both simple structure and controllability independent of the type of microprocessor elements used, simultaneously ensuring a rapid parallel data exchange between individual units and a high flexibility to reconfiguration, with the simplicity of intermodular connection being such that the requirement for complicated interface circuits and devices is avoided. This object is achieved in a multimicroprocessor system constructed of microprocessor units in which each unit includes a microprocessor, RAM and interface circuits, and input/output for intermodular data exchange and an instruction input, said instruction input being connected to an internal "data" bus through a buffer circuit, and the address lines and microprocessor control lines being connected to the remaining elements in the microprocessor unit. The multimicroprocessor system includes N-number of microprocessor units with their instruction inputs connected to a shared "instruction" bus and their input/outputs for data exchange connected to a switching unit. According to this multimicroprocessor system, the microprocessor address lines for element selection in the microprocessor unit are connected to the buffer circuit which serves to disable the connection between the internal "data" bus and the instruction input of said microprocessor unit, wherein a shared ROM-type memory, a shared RAM-type memory and shared input/output devices are connected through their data lines to the instruction bus of the multimicroprocessor system, and the address lines of the first microprocessor unit, which appears also as a control input, are connected both to the shared memories and shared input/output devices and to the "HALT" inputs of the microprocessors in the microprocessor units through a logic circuit, which serves to switch off the microprocessor units, as well as to the switching unit, which is designed as a register data exchange circuit. The above object is also achieved in a multimicroprocessor system in which the register circuit for parallel data exchange includes N-number of registers and a combination logic circuit, which connects the register input/outputs with the control input signals for data exchange between said registers, said combination logic circuit being characterized by /log2 (N+1)/ inputs, i.e. the smallest natural number not less than log2 (N+1), for setting the exchange code, wherein the first output of the combination logic circuit is connected to the enable circuit for connection between the first register output and the second register input, the second output line of the combination circuit is connected to an enable circuit for connection between the third register output and the second register input, etc., the (N-2)th output line is connected to an enable circuit for connection between the first register output and the (N-1)th register input, and the last output line is connected to an enable circuit for connection between the first register output and the last register input, wherein each register is provided with an input/output for connection with a given microprocessor unit, and the first register is provided with an additional input/output. The object of this invention is also achieved in a multimicroprocessor system which includes a number of SIMD multimicroprocessor systems hierarchically connected through a number of register data exchange circuits as those outlined above, where the additional input/outputs of the first registers in the data exchange register circuits of the SIMD multimicroprocessor systems are connected to the first hierarchic level data exchange register circuits, and the control inputs of register data exchange circuits are connected to the address lines of the first microprocessor unit in the first SIMD system within the group of systems; the additional input/outputs of the first level exchange register circuits are connected groupwise to the second level data exchange register circuits, the control inputs of said second level data exchange register circuits being connected to the address lines of that microprocessor unit whose address lines are connected to the first data exchange circuits in the group of first level data exchange registers, etc. On the last level of hierarchic connection between the microprocessor units, there is a single register data exchange circuit of the same type as that already discussed, with its exchange controlling inputs connected to the address lines of the first unit in the system. The advantages of the microprocessor system consist in the possibility for its implementation using arbitrary microprocessor elements, i.e. both monolithic and TTL microprocessors and circuits. The main advantage consists in its simple structure and simple connection between the microprocessor units, which obviates the need for complicated interface units and circuits. Both the executive and control units are of one and the same type, and the control unit also performs control functions. The register circuit for parallel data exchange ensures the possibility for high speed data exchange between the microprocessor units, contrary to the available sequential data exchange systems. The multimicroprocessor system with its hierarchic organization of the connection between the individul units possesses substantial advantages over the known systems especially concerning some classes of problems such as matrix calculations, signal processing, sorting, etc. It is an important advantage of the multimicroprocessor system that it possesses a high flexibility both concerning its designing and reconfiguration from one type to another. DESCRIPTION OF THE DRAWINGS The invention is illustrated by an example embodiment in connection with the accompanying drawings, in which: FIG. 1 is a block diagram of a microprocessor unit; FIG. 2 is a structural diagram of the SIMD multimicroprocessor system; FIG. 3 is a block diagram of the register data exchange circuit; FIG. 4 is a structural diagram of a hierarchically structured multimicroprocessor system; and FIG. 5 is a provisional structural diagram of 64 multimicroprocessor system constructed of 16 SIMD multimicroprocessor systems where each system is provided with 4 microprocessor units. DESCRIPTION OF THE PREFERRED EMBODIMENT A microprocessor unit (FIG. 1) includes a microprocessor 1, a RAM-type memory 2, a parallel input/output 3, and is provided with an input/output for external data 4, an input/output for data exchange with other units 5, a circuit 6 for sequential input/output with corresponding input/output and control lines 7, and an instruction input 8 connected to an internal "data" bus 9 through a buffer 10. Address lines 11 and control lines 12 are connected to the rest of circuits in the microprocessor unit, while inputs for timing pulses 13 and halt (switching off) pulses (HALT) 14 are provided to the microprocessor 1. It is a feature of the microprocessor unit that the address lines 11 for selection of the rest of the circuits in the microprocessor unit, are connected to the buffer 10 which disables the connection between the internal bus 9 and the instruction input 8. The multimicroprocessor structure (FIG. 2) consists of N-number of microprocessor units 16 with their instruction inputs 8 connected to a shared "instruction" bus 17 and their data exchange input/outputs 5 connected to a switching unit 18, a shared ROM-type memory 20, a shared RAM-type memory 21 and shared input/output devices 22 being connected through their respective data lines 19 to the instruction bus 17. The address lines 11 of the first microprocessor unit 16 which appears also as a control unit, are connected both to the shared memories 20, 21, the shared input/output devices 22 and HALT inputs 14 of the other microprocessor units 16 through logic circuit 23, which serves to switch off the microprocessor units 16, as well as to the switching unit 18, which is constructed as a register data exchange circuit. The internal connections of the address lines in the microprocessor units 16 and the connections between the first microprocessor unit address lines and the shared devices (20, 21, 22) are selected such that all the microprocessors possess one and the same allocation of their address fields, said fields containing the following addresses: addresses for RAM 2 and input/output devices 3 and 6 in the microprocessor unit, addresses for switching off each of the microprocessors through the logic circuit 23 as well as an address for switching off all the microprocessor units except the first one, an address for selection of the register data exchange circuit 18, addresses which represent exchange codes for the switching unit 18, addresses for storage of interruption addresses, and other addresses. The logic circuit 23 can be constructed from flip-flops of the "T" type, each of the outputs for the inputs 14 for switching off a microprocessor unit 16 being provided with one flip-flop. A signal to one of the flip-flops is sent in the case where a definite address is present on the address lines 11 of the first microprocessor unit 16. Also, a definite address enables the switching unit 18. In such a case, some of the direct addressable addresses can be over-lapped by the exchange addresses in the switching unit 18. The register circuit 18 for parallel data exchange (FIG. 3) consists of N-number of registers 25 and a combination logic circuit 26 by which the /log2 (N+1)/ number of control inputs 27 are, i.e. the smallest natural number not less than log2 (N+1), connected through the y1, y2, . . . , yN-1 outputs of the combination logic circuit 26 to the inputs and outputs, respectively, of the registers 25, wherein the first output y1 of circuit 26 is connected to an enable circuit 28 for connection between the output of the first register 25 and the input of the second register 25, the second output y2 is connected to an enable circuit 29 for connection between the third register output and the second register input, etc., the N-3th output line yN-3 is connected with an enable circuit 30 for connection between the output of the first register 25 and the next to the last register 25 input, the output yN-2 is connected with an enable circuit 31 for connection between the Nth register output and the (N-1)th register input, and the output yN-1 is connected with an enable circuit 32 for connection between the first register output and the last register input, all the registers 25 being provided with an input/output 33 for connection to a microprocessor unit 16 through its input 5, the first register 25 possessing also an additional input/output 34. Hierarchically structured multimicroprocessor system (FIG. 4) includes several SIMD multimicroprocessor structures 35 connected therebetween by several register data exchange circuits 18, where the additional input/outputs 34 of the first registers 25 in a definite number of systems 35 are connected to first level exchange register circuits 36, whose control inputs 27 are connected to the address lines 11 of the first microprocessor units 16 in the first system of the group 35, the additional input/output 34 of the first registers 25 in the first level exchange register circuits 36 are groupwise connected to the second level exchange register circuits, whose control inputs are connected to the address lines of that microprocessor unit 16 whose address lines are connected to the first register circuit for first level data exchange 36, etc., wherein, on the last hierarchic level of connection between microprocessor units 16, there is a single register data exchange circuit 37, whose control inputs are connected to the address lines of the first microprocessor unit 16 in the first SIMD system. In this case, the address field of the first microprocessor unit 16 should contain also addresses for control of the exchange taking place in the exchange circuits on each level starting from zero and reaching to the last level, while the other control units 16 should contain a lower number of such addresses. FIG. 5 shows a hierarchically structured MSIMD system consisting of 16 SIMD multimicroprocessor structures 35. Each structure 35 includes four microprocessor units 16 denoted as M0, . . . , M63, wherein each register data exchange circuit of zero (18), first (36) and second (37 ) level contains four registers 25 denoted as R0, R4, . . . , R60 with their numbers corresponding to the numbers of the units in the system. Register circuits 36 and 37 are controlled by the address lines of the first microprocessor units in the system. Systems of such a type can be designed with different number of units in the SIMD system 35 and different number of registers can be used in the register circuits. The minimum number of units in SIMD systems is two. A regular structure is achieved when all the SIMD systems include two modules (units) and each register circuit has two registers. Then, the number of levels is equal to /log2 N/. Connection in such systems resembles a tree structure. The multimicroprocessor structure (FIG. 2) operates as follows. All the microprocessor units 16 are started by the same initial address contained in their program counters, i.e. the address of the first instruction in the program recorded in the shared memory 20. One and the same instruction is actually read out of the shared memory 20 only by the first microprocessor 16 and since the buffers 10 are open, the instruction code enters through the bus 17 to all the microprocessor units 16. When said instruction contains an address of a local RAM 2 operand, each microprocessor unit 16 excecutes the instruction on the data contained in said address in its own RAM 2. At this point, the buffer 10 is closed and the bus 17 and internal bus 9 are disconnected one from the other. Each microprocessor unit 16 executes the instruction as a stand alone microcomputer. Upon execution of a definite number of instructions, some data exchange between microprocessor units 16 may be needed. This is achieved as follows: each microprocessor unit 16 sends its data through its output 5 for exchange in its respective register 25 in the register data exchange circuit 18, wherein the process takes place in parallel and uses one and the same instruction (subprogram) series. Then, a dummy instruction (for example, a kind of comparison without any variation in the content of the cells of memory) is executed. The logic circuit 23 decodes the address of the dummy instruction and a "HALT" signal is sent to the inputs 14 in order to switch off the microprocessor units 16. Similarly, an address is sent, which serves to enable, again through the logic circuit 23, the exchange circuit 18. The first microprocessor unit 16 then begins to read and "execute" dummy instructions, whose addresses are exchange codes to the circuit 18, until the desired shift of data in registers 25 is reached. It is necessary either to ensure that the dummy instructions do not change the data contained in the first microprocessor unit 16, or if impossible, to store the condition code preliminarily. Said dummy instructions should be short enough so as to reduce the necessary exchange time. Then, all the microprocessor units 16 are switched on (possibly with the address they have been switched off by the "T" flip-flops in the logic circuit 23, or in some other way) and start the execution of a subprogram for reading one word length data from their registers 25 through the input 5 of the parallel input/output circuit 3. Then, execution of the next instruction or re-exchange can be made. The data in the RAM 2 of each microprocessor unit 16 can be entered in parallel through the inputs 4 or transferred from the shared RAM 21 through the instruction bus 17, wherein, during the process of transfer to a given microprocessor unit 16, the other microprocessor units 16 in the structure should be switched off in advance. Also, data can be entered sequentially into the microprocessor units 16 through the inputs 7 of the sequential input/output circuits 6. A clock-pulse generator (not shown) sends timing signals through the respective microprocessor inputs 13. The register exchange circuit 18 operates as follows. When a definite code is sent to the input lines 27, one of the following transformations, subject to exchange between registers 25, is accomplished: ##EQU1## in which the series given above includes serial numbers of those registers 25 which receive the content of the respective lower row of registers 25. Algorithms and programs exist for expansion of an arbitrary transformation for exchange between all N-number of registers in a series of b0, b1, . . . , bN basic transformations. For example, if register (4) should send its given content into registers (1), (2) and (3) while receiving data from unit 1, and if the addresses which serve to accomplish the b0, b1, b2, b3, b4 transformations are 80, 81, 82, 83, 84, respectively, and the address A73 serves to switch off the microprocessor units (all addresses are in hexadecimal), following series of instructions to be executed by the first microprocessor unit (N=4; contents of the microprocessor units subject to exchange are in their respective registers) is required: DI81, DI84, DI83 because the necessary exchange can be represented by the transformation ##EQU2## which expands itself into the b3, b4, b1 series. The DIA73 instruction is introduced in advance, where DI is a dummy instruction code (i.e. instruction which does exist but does not initiate any reasonable action in view of the final result). If the transformation represents a permutation, then its expansion is not longer than N-1 and a simple analytical formula with corresponding program are available for this purpose. MSIMD multimicroprocessor system operates as follows. Each SIMD structure 35 runs its own program, which, in particular, possibly coincides with the program of another structure 35. If necessary, all the microprocessor units 16 in the system can exchange data between each other as desired, i.e. in a manner, described by an arbitrary transformation of all the elements-units, said exchange being performed as follows: the necessary transformation (let it be a permutation p) is expanded into a product of cycles (12), (123), . . . , (12 . . . N), where N is the total number of units in the system. Then, the cycles are accomplished in a sequence by parallel basic permutations in the register circuits for exchange on each hierarchic level. For example, if the required permutation for the system of FIG. 5 is p=(0 2 4 . . . 24 26 1 3 . . . 25 27 28 29 . . . 53 54) (which has been set as a single cycle and not as a notion in two rows), said permutation can be expanded by the standard procedure into the product (0 1 2 . . . 25 26)·(0 1 2 . . . 53 54). The first permutation is completed in three steps (one basic permutation in one step). During the first step, the permutations (0 1 2 3), (4 5 6 7), (8 9 10 11), (12 13 14 15), (16 17 18 19), (20 21 22 23), (24 25 26) are accomplished in parallel in the SIMD 35 systems, i.e., register circuits of zero level. During the second step, the permutations (0 4 8 12), (16 20 24) are accomplished in parallel in the register structures of first level. During the third step, the second level permutation (0 16) is accomplished, where the digits denote the numbers of the registers in the different level circuits, said numbers being equivalent to the numbers of the units in the system. The second permutation is accomplished also in three steps, where, during the first step, all complete cycles from (0 1 2 3) to (48 49 50 51) and the cycle (52 53 54) are accomplished. The cycles (0 4 8 12), (16 20 24 28), (32 36 40 44), (48 52) are accomplished in parallel in the second step, and the permutation (0 16 32 48) is accomplished in the third step. The complete permutation p is accomplished in 6 steps. Multimicroprocessor systems can be constructed using different microprocessor families while preserving said organization. In an embodiment of the present invention, different microprocessor systems were designed based on the INTEL and MOTOROLA microprocessor families, said families being only illustrative and not restrictive to the invention. Methods, algorithms and programs for parallel solution of different classes of problems were developed for said systems. When a ROM-type memory 38 is included in the microprocessor unit 16, the multimicroprocessor structure of FIG. 2 transforms into a SIMD/MIMD system, i.e. a system which allows for a functional reconfiguration from one type into another only according to the address contained in the program counter of the microprocessor 1 of said microprocessor unit 16. If the program counter addresses a program which has been included in the local memory 38, then the microprocessor unit 16 operates individually (i.e. the system is MIMD). It is possible that at times some of the microprocessor units 16 shown in FIG. 2 operate on their own programs while the rest of the microprocessor units 16 operate on the shared program contained in the shared ROM-type memory 20. Any microprocessor unit 16 can be switched from its own program to the shared program by an automatic call to an address which is outside the local address field of said microprocessor unit 16 and which contains a "common" for a number of microprocessor units 16 instruction. This functional reconfiguration, which takes place automatically, represents an essential advantage of the present invention especially due to its simplicity. This option extends the applicability of the present invention to various problems, increases the performance and results in memory savings for the system as a whole. The presence of ROM-type memory 38 in the microprocessor unit 16 ensures the possibility for automatic functional reconfiguration of the hierarchically structured multimicroprocessor system from MSIMD into M-SIMD/MIMD, SIMD or MIMD system. This reconfiguration increases the efficiency since the possible parallelism in the solution of some problems is not adequate so as to load all the microprocessor units. In such a case, some of the microprocessor units would operate on their own programs. A multiprogram mode of operation in the system is possible, in which a system constructed of N-number of microprocessor units can process in parallel N different kinds of problems distributed to the N microprocessor units. What is claimed is: 1. A multimicroprocessor system having a plurality of multimicroprocessor structures, each multimicroprocessor structure including N-number of microprocessor units coupled, collectively, to shared memory units and a shared input/output of the multimicroprocessor structure, said microprocessor units being the same and each microprocessor unit including a microprocessor, a data memory, a parallel input/output interface, a sequential input/output and a program memory; wherein said multimicroprocessor structures further comprise respective parallel data exchange register circuits to which the microprocessor units in each multimicroprocessor structure are respectively connected, said parallel data exchange register circuits having respective additional input/outputs; said multimicroprocessor system further comprising first level data exchange register circuits, to which said additional input/outputs of said parallel data exchange register circuits are connected, each first level data exchange register circuit having a control input, connected to address lines in a first of the microprocessor units in a first of said multimicroprocessor structures, and further additional input/outputs, and said multimicroprocessor system further comprising a second level data exchange register circuit, to which said further additional input/outputs of said first level data exchange register circuits are connected, said second level data exchange register circuit having a control input connected to the address lines in the first of the microprocessor units in the first of said multimicroprocessor structures in a first of said first level data exchange register circuits; and each of said microprocessor units further comprising a bi-directional buffer which serves to connect an internal data bus to a shared instruction bus in said multimicroprocessor structure for all of the microprocessor units, the buffer having enable inputs connected to internal busses for circuit selection in the microprocessor unit by the address lines of the microprocessor unit, the address lines of the first microprocessor unit being connected also to the shared memory units in the multimicroprocessor structure, to the shared input/output as well as both to the respective parallel data exchange register circuits and "HALT" inputs of microprocessors in the other microprocessor units in each multimicroprocessor structure through a logic circuit, which serves to switch off the microprocessor units. 2. A multimicroprocessor system as claimed in claim 1, wherein the parallel data exchange register circuits each comprise N-number of interconnected registers, a combination circuit and bi-directional busses for input/output of data to the registers, wherein /log2 (N+1)/ number of control inputs, i.e. the smallest natural number not less than log2 (N+1), are provided to the combination circuit with the outputs of said combination circuit connected to enable circuits for parallel connection between registers, where a first of said outputs is connected to an enable circuit for connection between an output of a first of said registers and an input of a second of said registers, a second of said outputs is connected to an enable circuit for connection between an output of a third of said registers and an input of the second register, and a (N-3)th of said outputs is connected to an enable circuit for connection between the first register output and an input of the next to the last register, an (N-2)th of said outputs is connected to an enable circuit for connection between an output of a last of said registers and the next to the last register input, a (N-1)th of said outputs is connected to an enable circuit for connection between the first register output and an input of the last register, and an Nth of said outputs is connected so as to enable the connection between the second register output and the first register input, where the first register is provided with said additional input/output.

1983-04-26

en

1986-05-27

US-20687894-A

Character image display apparatus for a camera ABSTRACT A character image display apparatus in a film device with a lens mounted thereon or a camera is constructed such that a hole is provided on a reflector in a flash unit provided on a body of the camera, one end of a photoconductor is fixed to the hole and the other end thereof is connected to a diffusion block disposed so as to face an exposure window on the body, and a display device in which a positive film of a display image such as a character image sticked on a plane of the diffusion block is disposed in front of a film in fixed relationship to a shading corrugation within an exposure portion of the camera body, whereby when photographing is performed, a light ray from the flash unit is introduced by the photoconductor and a display image such as a character mark is simultaneously exposed simultaneously exposed as a part of a photographing image with light rays uniformed by the diffusion block. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simplified display apparatus for a camera into which a photographed image and a or the like at a photographing position can be taken simultaneously. 2. Prior Art In ordinary cameras, various data photographing apparatus capable of simultaneously taking a picture of photographing data or the like together with a photographing image have been developed and put into practise. These apparatus are constructed such that an illumination apparatus for the exclusive use of photographing data for introducing external light onto a camera body or a back lid is mainly provided, or a photographing data is simultaneously taken in a picture together with a photographing image on a film with a data apparatus provided before or behind the film by utilizing exposure light from a photographing lens. However, since a photographing data is taken in a picture in superposed relationship on a part of a film together with a photographing image, for example, there may be caused a case where the data is not distinctly legible in the finished photograph as in the case where an over-exposed object being photographed is taken in a part of a photographing image on which the data is taken in a picture. Also, in a film device with a lens mounted thereon (camera), its cost is a big problem and its body is provided with an expensive data photographing apparatus, thus it being complicated. SUMMARY OF THE INVENTION An object of the present invention is to provide a simplified character image display apparatus for a camera which is capable of clearly photographing a display image, such as a character simultaneously with the image being photographed. The present invention is a character image display apparatus in a film device with a lens mounted thereon in which a hole is provided on a reflector in a flash unit provided on a body of said film device, one end of a photoconductor is fixed to the hole and the other end thereof is connected to a diffusion block disposed so as to face an exposure window on the body, and a display device in which a positive film of a display image such as a character image sticked on a plane of the diffusion block is disposed in front of a film in fixed relationship to a shading corrngation within an exposure portion of body, whereby when photographing is performed, a light ray from the flash unit is introduced by the light guide and a display image such as a character mark is simultaneously exposed as a part of a photographing image with light rays uniformed by the diffusion block. In the present invention, an illumination light ray from the flash unit is introduced by the light guide to illuminate a display image such as a character mark with light rays uniformed by a diffusion block and the sidplay image is simultaneously photographed on a film together with a photographing image, resulting in that a display mark such as character mark can be clearly and simultaneously taken in a picture with a simple apparatus composed of only inexpensive members. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the structure of a character display apparatus of the present invention in a camera; FIG. 2 is a front view of the camera shown in FIG. 1; FIG. 3 is a perspective view showing an example of fixing a light guide to a diffusion block; FIG. 4 is a perspective view showing another example of fixing the light guide to the diffusion block; FIG. 5 is a front view of a display mark; and FIGS. 6(A) and (B) are front views of finished photographs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention will be described hereinafter with reference to the attached drawings. FIG. 1 shows the back view of the body of a camera with its back lid removed. FIG. 2 shows the front view thereof. Specifically, the camera has a photographic lens 1 at the center of the camera, a view finder 2 and a flash unit 3 at the upper front thereof, and a button 4 for operating the flash unit. A body 5 of the camera is integrally formed and has an exposure portion 6 extending rearward in a pyramid shape through which light passes at the center of the body 5, and an opening as an exposure window at a film pressing portion 9 is disposed between opposite sides of the body 5 for receiving a film cartridge 8. A plurality of shading corrugations 10 are formed within the exposure portion 6. The flash unit 3 comprises a diffusion plate 11, a flash bulb (not shown) and a reflector 12. The reflector 12 is provided with a hole 13. One end of a light guide 14 is at hole 13 so that light from the flash bulb can pass through the light guide 14. The light guide 14 is preferably an optical fiber bundle. The other end of the light guide 14 is inserted into a hole 16 of a diffusion block 15 which is fixed to the shading corrugation 10 in the exposure portion 6. The diffusion block 15 has a display plane 15a (FIGS. 3 and 4) disposed so as to be in contact with the film pressing portion 9. Referring to FIGS. 3 and 4, the diffusion block 15 receives illumination from light guide 14 which is uniformly distributed over display plane 15a. The tip of the light guide 14 is inserted into the hole 16 of the diffusion block 15 and is disposed perpendicularly to the display plane 15a, as shown in FIG. 3, and is adhesively fixed therein. The tip of light guide 14 ends in a plane that is substantially perpendicular to the longitudinal axis of the light guide 14. Referring to FIG. 4, the light guide 14 is inserted laterally to the display plane 15a, that is, in a direction parallel to display plane 15a, and the tip of the light guide 14 is obliquely cut to have a light dispersion plane 14a facing the display plane 15a. An image on a positive film 17 which is prepared by photographing a character mark or the like as shown in FIG. 5, is adhered to a display plane 15a on the film side of the diffusion block 15. Accordingly, when the shutter 18 is depressed, the flash unit 3 emits light to expose the film and illuminate the image such as a character mark on the display plane 15a with light rays uniformed by the diffusion block 15 by introducing, the light from the flash unit 3 by the light guide 14, thereby a very clear image being simultaneously exposed on a part of an exposure area of the film. While there is no limitation in size of the diffusion block 15, judging from a taken picture, it is most suitable to dispose the display plane 15a at the four corners within an exposure portion 6 or on the full surface of the lower side within the exposure portion 6. When an exposure value of a display image does not agree with that of a photographing image due to a size of the display plane 15a or an image density of a character mark or the like, it is possible to easily make the amounts of exposures equal by increasing a size of the photoconductor 14. Consequently, a printed photograph is a picture having the clear display image 19a such as a character in a part of the exposure image 19, as shown in FIGS. 6 (A) and (B). As described above, a character display apparatus of the present invention in a camera is composed of very inexpensive light guide and diffusion block on the display plane of which a mark is only sticked. With such a structure, it is possible to simultaneously photograph a very clear display image in a part of an object being photographed together with the latter. Consequently, a photograph adapted to a place of selling films or an event performed in the place can be provided without raising a price of the film device, leading to highly raise a value for a commemorative picture. What is claimed is: 1. A character image display apparatus for a camera, comprising:a camera body having a film exposure portion and a film plane; a flash unit having a reflector for illuminating a subject being photographed, the flash unit being housed on the camera body; a light guide having an end thereof connected to the reflector through a hole in the reflector, thereby light emitted from the flash unit being transmitted through said light guide; a diffusion block fixed to the camera body within the exposure portion of the body, the diffusion block having a display plane substantially parallel to the film plane of the camera body, and a positive film of a display image being disposed on said display plane and thereby facing the film plane of the camera body, and an opposite end of the light guide disposed in the diffusion block such that during the photographic process light from the flash unit is introduced through the light guide to the diffusion block to uniformly illuminate the display image and thereby the display image being simultaneously photographed with a subject being photographed. 2. The character image display apparatus of claim 1, wherein said display image is a character image. 3. The character image display apparatus of claim 1, wherein said positive film is adhesively adhered to the display plane of the diffusion block. 4. The character image display apparatus of claim 1, wherein the opposite end of the light guide in the diffusion block has a light dispersion plane which is disposed substantially parallel to the display plane of the diffusion block. 5. The character image display apparatus of claim 4, wherein the light dispersion plane is oblique to the longitudinal axis of the light guide. 6. The character image display apparatus of claim 4, wherein the light dispersion plane is substantially perpendicular to the longitudinal axis of the light guide.

1994-03-07

en

1996-01-23

US-7052560-A

Transmission May 21, 1963 H. o. scHJoLlN ErAL TRANSMISSION 4 Sheets-Sheet 1 Filed Nov. 2l, 1960 Hllli ff" fa IN VEN TOR/.5` ATTORNEY May 21, 1963 K H. o. s'cHJoLIN ETA). 3,090,257 TRANSMISSION Filed Nov. 2l, 1960 4 Sheets-Sheet 2 ATTOR NEY May 2l, 1963 H. o. scHJoLIN ET AL 3,090,257 TRANSMISSION Filed NOV. 2l, 1960 4 Sheets-Sheet 3 IN VEN TORJ AT TORNEY May 21, 1963 H. o. scHJoLlN ETAL 3,090,257 TRANSMISSION 4 Sheets-Sheet 4 Filed NOV. 2l, 1960 3,090,257 ce Patented May 2l, 1963 3,690,257 TRANSMISSION Hans O. Schjoiin, Birmingham, Luther N. Kern, Berkley, and Millis V. Parshall, Pontiac, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Nov. 21, 1960, Ser. No. 70,525 11 Claims. (Cl. 74-781) This invention relates to transmissions and more particularly to a transmission incorporating planetary gearing and clutch and brake mechanism adapted to provide neutral plus a plurality of drive ratios. An object of this invention is to provide a transmission incorporating planetary gearing and a neutral clutch wherein a Belleville spring is normally eiective to engage the clutch to transmit drive to the gearing. Another object of this invention is to provide a clutch and gearing arrangement of the type described wherein a Belleville spring is supported at its outer periphery on a clutch drum in such manner that the clutch drum serves as the reaction member for the Belleville spring and the spring is normally elective to engage the clutch. A further object of this invention is to provide a mounting for a Belleville spring adapted to actuate a clutch which is of simple low cost construction. An additional object of this invention is to provide a drive ratio control mechanism incorporating a clutch unit and a brake unit arranged in tandem wherein a single Belleville spring is utilized to actuate both units. A particular object of this invention is to provide drive ratio control mechanism for a transmission incorporating a clutch unit and a brake unit arranged in tandem and incorporating a Belleville spring for selectively actuating said units wherein the Belleville spring is effective in and or" itself to establish direct drive through the transmission. A more particular object of this invention is to provide a drive ratio control unit for a transmission incorporating a clutch unit and a brake unit wherein a Belleville spring extends between said units at the outer periphery of the spring and wherein a single piston acting on the inner periphery of the spring is effective when supplied with iluid pressure to move the spring to release one unit and engage the other unit. An additional object of the invention is to provide a clutch and brake unit of the class described which is specifically designed to lbe assembled as a subassembly and to be easily and quickly assembled into the complete transmission assembly. These and other objects of this invention will lbe apparent from the following description and claims taken in conjunction with the accompanying drawings, in which: FIGURE 1 is a transverse sectional view of one ernbodiment of the invention. FIGURE 2 is a transverse sectional View of the clutch and lbrake assembly adapted to be preassembled as a subassembly for installation in the complete transmission assembly. FIGURE 3 is an enlarged View illustrating the means for retaining the clutch and brake subassembly in the completed transmission. FIGURE 4 is a transverse sectional view of a second transmission assembly incorporating the invention. Referring to FIGURE l there is shown a transmission housing having an engine driven power input shaft 11 extending therein through an oil seal 12. A flywheel or clutch drum 13 bolted to shaft 11 -by bolts 14 provides a drive clutch surface 15. Drum 13 is provided with a ring or starter gear 16 and a reaction member l17 adapted to retain a Belleville spring 75 on the clutch drum, the retainer' 17 being detachably secured to drum 13 by means of bolts 13. A series of flats 19 on drum 13 receive a clutch separator plate 20 and a presser plate 21. Slotted tangs 22 and 23 on separator plate 26 and presser plate 22, respectively engage surfaces 19 such that members 20 and 21 rotate with drum 13 but are axially slidable with respect to the drum. An annular axially extending boss 24 on presser plate is engaged lby Belleville spring 75. A planetary gearing unit 25 includes a planet carrier 26 supporting a plurality of pinion gears 27 in mesh with a sun gear 28 and a ring gear 29. Driven clutch plates 30 and 31 extend outwardly from an extension 32 of carrier 26 between drive surface 15 and separator 20 and between separator 20 and presser plate 21, respectively. A series of axially extending splines 33 on extension 32 permit axial motion of clutch plates 3i) and 31 with respect to carrier 26 while at the same time cause rotation of the plates as a unit with the carrier. Pinion gears 27 are each rotatably supported on a stub shaft 34 in carrier 26 4by means of needle bearings 35. Carrier 26 is freely rotatable with respect to a power delivery shaft 110. A ring gear support 36 is splined to power delivery shaft 110 for rotation therewith, the support having an axial extension- 37 splined to shaft 110. A bushing 38 supports ring gear `extension 37 and one end of shaft 110 in drum 13 for rotation with respect to the drum. A sun gear assembly 39 formed integrally with sun gear 28 includes a portion 40 contacting shaft 110, a recessed portion 41 and a radially outwardly extending flange 42. A bushing 43 supports the recessed portion 41 on shaft 110 at the juncture of recessed portion 41 and ilange 42. A drum 44 is bolted to flange 42 and a plate 45 is bolted to drum 44 by means of bolts 46 and 47 shown in FIGURE 2. Drive clutch plates 48 and a pressure plate 49 are splined to drum 44 for axial motion with respect to the drum. A series of discs 51 and a pressure plate 50 are splined to drum `44 for axial motion with respect to the drum. A Belleville spring 52 has its outer periphery retained on drum 44 by a pair of pivot rings 53 and 54. A clutch hub 56 splined to shaft 110 car-ries a series of driven clutch discs 55, the disc 55 being axially 4movable on hub 56 and extending radially outwardly between discs `48 and pressure plate 49. A retainer 58 has a series of discs 59 splined thereto and extending radially outwardly between discs 51 and pressure plate 50. Retainer 58 includes a radially inwardly extending member 60 cooperating with a piston 61 to form a chamber 62 adapted to receive fluid under pressure. A housing member 63 includes an axially extending sleeve 64 contacting shaft 110 and providing a support for an annular sleeve extension 65 formed on piston 61. Sleeve 65 extends outwardly from chamber 62 at the inner end of member 6i), there being a ring 66 and a washer 67 on sleeve extension 65 held on the sleeve by means of a snap ring 68. Ring 66 is rotatable on sleeve 65, there being a bearing 69 disposed intermediate ring 66 and washer 67. Belleville spring 52 is normally effective to pivot about pivot rings 53-54 to engage clutch discs 48-55 Fluid pressure may be admitted through a pipe 7l), passages 71, '72 and 73 to chamber 62 to cause piston 61 to move to the right, the piston carrying the Belleville spring 52 to the right to release clutch discs 48-55 and engage friction discs 51-59, the Belleville spring acting as a lever to apply force to pressure plate `50. It will be noted that sleeve extension 64 extends to the end of clutch hub 56 beneath sleeve extension 65 of piston 61 to provide a support surface for extension 65. Retainer 17 is provided with an inwardly extending annular rim 74 adapted to receive the outer periphery of Belleville spring 75, the inner periphery of spring 75 terminating in a retainer 76 on a clutch actuator sleeve 77. spaanse' Sleeve 77 is rotatably driven by spring 75 through a drive lug 78. A gear 79 for-med integrally with sleeve 77 mates with a gear 80 on a pump drive shaft S1 such that a pump 82 is continuously driven through Belleville spring 75, The pump S2 may Vsupply oil under pressure for actuating piston 61 through suitable control -valving (not shown) and for lubrication purposes. A manually operable clutch actuator fork indicated generally at 8S includes a pair of arms 86 and 87 lon the fork, the arm 86 carrying a pin 8S supporting a fiber roller 89 thereon and the `arm S7 carrying a pin 90 supporting a fiber roller 91 thereon. As shown at the right-hand end of FIGURE l oil for lubrication purposes may be admitted through a pipe 95, passage 96 in member 58, chamber 97, passage 9 8 in member 64;, and passages 99, 100, 101, 102, 103 and 104 in shaft 110. Shaft 110 is Supported in housing member 63 by means of a ball bearing 92. As shown particularly in FIGURE 2, the subassembly including sun gear 28, drum 44, plate 45, hub 56, retainer member 5,8, piston 61, Belleville spring 52, ring 66, bearing 69, Washer 67, discs #iS-55, discs 51-59 and bushing 43 are all preassembled as a subassembly and adapted to be quickly and simply assembled to the complete assembly as a unit. As shown in FIGURE 3, retainer 58 is provided with a recess 105 adapted to receive a retainer 106, the retainerV 1&6 being bolted to housing 10- by bolts 107. Retainer 106 in recess 105, prevents rotation of member `58. Housing 10 is detachably secured to housing 109 by bolts 10S shown in FIGURE 1. It will readily be understood that the arrangement whereby the subassembly described may be quickly and simply installed as a unit or removed as a unit facilitates use lof assembly and disassembly, thereby reducing costs of production and servicing of the transmission. The clamp member 106 is easily and simply installed to retain the subassembly in its proper position in the transmission. In operation of the arrangement shown in FIGURES l through 3, a positive neutral, direct drive and overdrive may be obtained. Power delivery shaft 110 may drive a manually shiftable gear box or automatic 4transmission capable of providing additional drive ratios and reverse as desired. Belleville spring 75 normally pivots about retainer 17 on clutch drum I13 to force pressure plate 21 into its clutch engaging position. In the event that positive neutral or no drive is desired, the forks 86 and 87 are manually actuated through a clutch pedal and shaft arrangement (not shown) to move clutch actuator sleeve 77 to the right, thus pulling the inner end of Belleville spring 75 to the right to release pressure plate 21. The fiber rollers S9 and 91 bear on the side of gear 79 during the interval in which the clutch is released and provide a rolling contact with the rotating gear. It has been found that the fiber rollers provide a long and useful life and are much less expensive than roller bearings in the present application. Belleville spring 52 is normally effective to engage clutch discs 48-55 to establish direct drive through the planetary gearing unit. With clutch discs 48-55 engaged sun gear 28 is locked to power delivery shaft `110. With both ring gear 29 and sun gear 28 fixed for rotation with power delivery shaft 110, the planetary gearing unit is locked up in direct drive. For overdrive operation through the planetary gearing unit, fluid pressure from pump 82 may be admitted to chamber 62 through passages 70, 71, 72 and 73 under control of suitable control valving, not shown. The control valving may be manually controlled by the vehicle operator as by means of a suitable solenoid valve to .either connect chamber 62 to exhaust or admit fluid under pressure to the chamber. Movement of piston 61 to the right in response to fluid pressure will release Belleville spring 52 from pressure plate 49 and cause Belleville spring 52 to act =as a lever to engage pressure plate 50 to yfriction discs 571-59. The Belleville spring acts as a 4 common operating member to actuate both pressure plates 49 and 50. With discs 51-59 engaged sun gear 28 is locked against rotation and functions las a reaction member for the gear unit. Shaft will rotate faster than engine shaft 11, or in overdrive. lt will be understood that in the event of pump failure or loss of fluid pressure, Belleville spring 52 will automatically engage clutch discs 43-55 to place the gear unit in direct drive. This is a considerable advantage in the event of uid pressure loss when operating on the highway in that it is often undesirable to operate in overdrive in hilly country or Where maximum acceleration is desired. Also the gear unit is protected against failure as might otherwise occur in the event it was to be operated in overdrive with low oil pressure. The tandem arrangement of the discs reduces the vertical space required and makes possible the dual function of Belleville spring 52 and the use of a single piston in the assembly. The arrangement reduces costs by utilizing interchangeable parts in both disc assemblies, the single spring 52 and single piston 61. The design of Belleville spring 75 mounted directly on retainer 17 further reduces costs by providing a simple low-cost Belleville spring mounted on the clutch housing and directly engaging the clutch. The fiber rollers 89, 91 further reduce costs as compared to using a ball bearing. The provision of the subassembly of the discs in tandem as a unit and clamp arrangement whereby fthe subassernbly may be quickly and easily installed and removed further reduces manufacturing and service costs. Referring to FIGURE 4 there is shown a transmission assembly similar to that of FIGURES l through 3 but arranged to provide either underdrive or direct drive through the planetary gearing unit. ln FIGURE 4 an engine driven power input shaft i114 drives an engine flywheel or clutch drum 116 having a retainer 117 bolted thereto by bolts 118. Clutch drum 116 is provided with ilats A1119 adapted to receive tangs 121 of a presser plate 120. Presser plate 120 is axially movable with respect to drum 116 and rotatable therewith and is provided with an upstanding axially extending annular boss 122. A planetary gearing unit 123 is composed of a planet carrier 124 supporting a plurality of pinion gears 125 in mesh with a ring gear 126 and a sun gear 127 Planet carrier 124 is splined to a power delivery shaft 115 to drive the same. A drive clutch plate 128 is bolted to ring gear 126 and extends outwardly between presser ',120 and clutch drum 116. A sleeve extension 129 formed integrally .vru'th sun gear 127 is provided with an upstanding flange 130 bolted to a clutch drum 131 having a plate 132 fixed thereto at the opposite side of the drum from iiange l130. Drum 131 is provided with a set of friction discs 133 and a second set of discs 133', the discs of each set being interchangeable. Discs 133 and a pressure plate 131iare axially movable on drum 131. Discs 133 and a pressure plate 135 are likewise axially movable on drum 131, all of the discs and pressure plates being fixed to drum 131 for rotation therewith. A clutch hub 136 splined to power delivery shaft 115 carries a series of friction discs 137 thereon, the discs being splined to hub 136 for axial motion thereon. A retainer 138 bolted to housing 112 carries a series of friction discs 139 splined thereon for axial motion with respect thereto. A downwardly depending ange 140 on retainer 13S forms a chamber 141 having a piston 142 therein, the piston having a sleeve portion 143 extending outwardly from chamber 1411. A ring 144- and washer 145 are carried by sleeve 143, there being a bearing 146 between the ring and Washer. A pair of pivot rings 147 and 148 fixed to drum 131 receive the outer periphery of a Belleville spring 149 therebetween, the inner periphery of spring 149 contacting ring 144. Fluid under pressure may be admitted to chamber 141 for transmission drive ratio control purposes through passages 150, 151, 152 found in retainer 133. Fluid for lubrication purposes may be admitted through passages 153, y154i and 155 found in retainer 13S. A bushing 156 disposed between planet carrier 124 and clutch drum 116 rotatably supports carrier 124 and one end of shaft 115. A ball bearing 157 rotatably supports the other end of shaft 115 in housing portion 112. Drum 116 is supported on shaft 144 which extends through an oil seal '177. Retainer ring 117 has a flange or annular lip 160 formed thereon to receive the outer edge of a Belleville spring 161. A clutch actuating sleeve 162 is provided with an upstanding flange 163 at one end thereof and a pump drive gear 164i at the other end thereof, the inner edge of Belleville spring 161 being in contact with flanges 163. A clutch release yoke is provided with arms 165 and 166 contacting the outer race 167 of a roller bearing assembly 168 carried lby sleeve 162. Gear 164 meshes with a gear 169 on a pump shaft 170 of a pump 171. Belleville spring 161 `drives sleeve 162 through a drive connection 172. In operation spring 161 is normally effective to engage pressure plate 12) to clutch plate 12S to establish drive through the planetary gearing, the ring retainer 117 functioning as the reaction point for the Belleville sprin-g. In the event that a positive neutral is desired, the forks 165 and 166 may be actuated through suitable linkage (not shown) to move sleeve 162 and the inner end of Belleville spring 161 to the righ-t to release the main drive clutch. Belleville spring 149 is normally eiective to force pressure plate 134 to engage clutch discs 132-137, the rings 147 and `1418 serving as the reaction point lfor the spring. In this condition of operation sun gear 127 is clutched to power delivery shaft 115 to provide direct drive through the planetary gearing unit. In order to change drive ratio, fluid pressure may fbe admitted to chamber 141 through passages 151, 152 and 153 to cause piston 142 to move the inner end of Belleville spring 149 to the right, thereby releasing pressure plate 134 and forcing pressure plate 135 to engage discs 13S- 139. Sun gear 127 will thereby -be held against rotation to provide reduction drive through the planetary gearing unit. While the embodiment in FIGURES 1 through 3 is the preferred embodiment, it will readily be understood that the embodiment in FIGURE 4 includes many of the advantages of the preferred embodiment including the use of tandem sets of friction discs, the use of a single Belleville spring effective to provide direct drive through the gear unit in the event of loss of fluid pressure and to alternately actuate both sets of discs and the single piston for controlling the Belleville spring. The housing sections 11,1 and 112 of FIGURE 4 and 9 and 10 of FIG- URE l are detachably secured together by bolts 158 and 19S, respectively, to facilitate assembly and disassembly of the transmissions. We claim: l. In a transmission of the type having a power input shaft, a power delivery shaft and a planetary gearing unit disposed between said power input shaft and power delivery shaft including a planet carrier supporting a plurality of planet pinion gears in mesh with a ring gear and a sun gear and having a drum member rotatable as a unit with said sun gear; said drum member having a first set of friction elements effective when engaged to establish `one transmission drive ratio and a second set of friction elements effective when engaged to establish a second transmission drive ratio, means normally effective to engage said first set of friction elements including a Belleville spring in said drum element, and means for moving said Belleville spring to release said first set of friction elements and to engage said second set of friction elements. 2. In a transmission of the type having a power input shaft, a power delivery shaft and having a planetary gearing unit disposed :between said shafts including a planet carrier supporting a plurality of planet pinions in mesh with a ring gear and a sun gear and having means for controlling the transmission drive ratio including a drum rotatable with one element of said gearing unit; a first set of friction discs disposed within said drum effective when engaged to establish one drive ratio through said transmission, a second set of friction discs arranged in axial alignment with said first set of friction discs effective when engaged to establish a second transmission drive ratio, means normally effective to engage said first set of friction discs comprising a Belleville spring pivotally supported in said drum, a piston operably connected to said Belleville spring and adapted to receive fluid pressure, said piston being movable in response to fluid pressure supplied thereto to move said Belleville spring about its pivot to release said first set of friction discs and engage said second set of friction discs. 3. In a transmission of the type having a power input shaft, a power delivery shaft and having means for transmitting torque from said input shaft to said power delivery shaft including a planetary gearing unit having a planet carrier supporting a plurality of planet pinions in mesh with a ring gear and a sun gear and having means for `controlling the transmission drive ratio including a drum rotatable with one element of said gear unit; an engageable and releasable clutch in said drum effective when engaged to clutch said drum to said power delivery shaft, an engageable and releasable brake in said drum effective when engaged to brake said drum against rotation, a Belleville spring pivotally supported in said drum and normally effective to engage said clutch, a chamber having a piston therein and operably connected to said Belleville spring, said piston being movable in response to fluid pressure supplied to said chamber to move said Belleville spring to release said clutch and to engage said brake. 4. In a transmission of the type having a power input shaft, a power delivery shaft and havin-g means for transmitting torque from said power input shaft to said power delivery shaft including a planetary gearing unit having a planet carrier supporting a plurality of planet pinions in mesh with a ring gear and a sun gear and means for controlling the transmission drive ratio including a drum fixed for rotation with said sun gear; an engageable and releasable clutch in said drum effective when engaged to establish direct `drive through said gear unit, an engageyable and releasable brake in said drum effective when engaged to establish a second drive ratio through said transmission, means normally effective to engage said clutch including a Belleville spring pivotally supported in said drum, a chamber within said drum adapted to be filled with and exhausted of fluid pressure, a piston within said chamber, said piston having a sleeve extending out of said chamber and operably connected to said Belleville spring, said piston .being effective in response to fluid pressure supplied to said chamber to move said spring to release said clutch and engage said brake. 5. yIn a transmission of the type having a power input shaft, a power delivery shaft and having a planetary gearing unit adapted to operably connect said power input shaft to said power delivery shaft in one 'of two drive ratios and including a planet carrier supporting a plurality of pinion gears in mesh with a ring gear and a sun gear and a drum fixed for rotation with said sun gear, an engageable and releasable clutch disposed in said drum effective when engaged to connect said drum to said power delivery shaft to establish direct drive through said gear unit, an engageable and releasable brake in said drum effective when engaged to prevent rotation of said drum to establish a lsecond transmission drive ratio, said brake including a retainer fixed against rotation and forming a chamber adapted to recieve lfluid under lpressure, a piston in said chamber having a sleeve portion extending out of said chamber, and a Belleville spring pivotally sup- 7 ported on said drum and operably connected to said piston, said Belleville spring being normally effective to en gage said clutch, said piston being movable in response to fluid pressure supplied to said chamber to move said spring to release said clutch and apply said brake. 6. vIn a transmission of the type having a transmission. housing and a power input shaft and a power delivery shaft rotatably supported in said housing and a planetary gearing unit disposed between said power input shaft and. said power delivery shaft including a planet carrier sup-- porting a plurality of planet pinion gears in mesh with a. sun gear and a ring gear and a subassembly for controlling the transmission drive ratio and adapted to be assembled as a unit in said housing including a drum fixed toV said sun gear; a clutch unit and a brake unit, said brake: unit including a retainer adapted to be clamped to said housing and forming a chamber adapted to receive uid pressure, said subassembly also including a Belleville spring pivotally supported in saidv drum and a piston in said chamber having a sleeve extending outwardly from said chamber and operably connected to said Belleville spring, said spring being normally effective to engage said clutch to establish direct drive through said gear unit, said piston being movable in response to tiuid pressure supplied to said chamber to actuate said spring to release said clutch and apply said brake to establish a second transmission drive ratio. 7. In a transmission of the type having a power input shaft and a power delivery shaft and a planetary gearing unit including a planet carrier supporting a plurality of planet pinions in mesh with a ring gear and a sun gear, said gear unit having one element thereof fixed for rotation with said power delivery shaft and a second element thereof driven by said clutch plate; drive ratio control mechanism for controlling the gear unit drive ratio comprising a drum member fixed for rotation with a third element of said ygear unit, an engageable and releasable clutch disposed within said drum effective when engaged to clutch said drum to said power delivery shaft to establish direct drive through said gear unit, a retainer member extending into said drum forming a chamber within said drum adapted to Ibe supplied -with fluid under pressure, a brake in said drum efiecti-ve when engaged to brake said drum against rotation, a piston in said chamber having a portion extending out of said chamber, a Belleville spring pivotally supported in said drum and operably connected to said piston extension, said Belleville spring being normally effective to engage said clutch, said piston being movable in response to fluid pressure supplied to said chamber to actuate said Belleville spring to release said clutch and engage said brake. 8. In a transmission assembly of the type having a housing, a power input shaft, a power delivery shaft, a planetary gearing unit in said housing adapted to selectively connect said power delivery shaft to said power input shaft in one of two drive ratios, said planetary gearing unit having a first element driven by said power input shaft, a second element fixed for rotation with said power delivery shaft, and a third element adapted to be selectively connected to said power delivery shaft and to said said housing; an improved drive ratio control including a rotatable drum disposed within said housing and connected for rotation as a unit with said third transmission element, a first set of friction elements in said drum effective when engaged to connect said drum to said power delivery shaft, a second set of friction elements in said drum etective when engaged to connect said drum to said housing, a chamber within said housing adapted to receive fluid under pressure, a piston in said chamber, a Belleville spring in said housing pivoted to said drum intermediate said sets of friction elements, said Belleville spring being normally effective to engage one of said sets of friction elements when said chamber is exhausted of fluid under pressure, said piston extending outwardly from said chamber into operable relationship with said Belleville spring, said piston being movable in response to fluid pressure in said chamber to move said spring to disengage lsaid first set of friction elements and to engage said second set of friction elements. 9. In a transmission assembly of the type having a housing, a power input shaft, a power delivery shaft, a planetary gearing unit in said housing adapted to selectively connect said power delivery shaft to said power input shaft in one of two drive ratios, said planetary gearing unit having a first element driven by said power input shaft, a second element fixed for rotation with said power delivery shaft, and a third element adapted to be selectively connected to said power delivery shaft and to said housing; an improved drive ratio control unit disposed within said housing, said unit including a rotatable drum disposed within said housing and supported for rotation on said power delivery shaft, said drum being connected for rotation as a unit with said third element, means oper- .able to connect said drum to said power delivery shaft including a first set of engageable and releasable friction elements disposed within said drum, means operable to connect said drum to said housing including a second set of engageable and releasable friction elements disposed within said drum, a chamber formed by said housing and extending into said drum, a Belleviile spring pivoted to said drum and normally effective to engage said first set of friction elements, a piston said chamber having a portion thereof extending outwardly from said chamber ,and cooperating with said Belleville spring, said piston 'being movable in response to tiuid pressure in said chamber to move said Belleville spring to release said first set of friction members and to engage said second set of friction members, and means in said housing for admitting Afluid under pressure to said chamber. 10. In a transmission assembly of the type having a housing, a power input shaft, a power delivery shaft, a planetary gearing unit in said housing adapted to selectively vconnect said power delivery shaft to said power input shaft in one of two drive ratios, said planetary gearing unit having a first element driven by said power input shaft, a second element fixed for rotation with :said power delivery shaft, and a third element adapted to be selectively connected to said power delivery shaft and to said housing; an improved drive ratio control unit disposed within said housing, said improved drive ratio control unit including a rotatable drum disposed for rotation within said housing, a sleeve extension connecting said drum to said third element for rotation therewith as a unit and rotatably supporting said drum on said power Idelivery shaft, a clutch hub disposed within said drum and fixed to said power delivery shaft for rotation therewith as a unit, engageable and releasable clutch members within said rotatable drum carried by and rotatable with said drum and clutch hub respectively, a brake hab disposed within said rotatable drum and fixed against rotation, engageable and releasable brake members car- `ried by said drum and brake hub respectively, said brake hub forming a chamber adapted to receive fluid under pressure, a Belleville spring disposed between said brake and clutch hubs and normally effective to engage said clutch members and release said brake members when said chamber is devoid of fluid under pressure, a piston in said chamber having a portion extending outwardly from said chamber into cooperative relationship with said Belleville spring, said piston being movable in response to tiuid pressure to move said Belleville spring to release said clutch members and to engage brake members, rcspectively. ll. In a transmission assembly of the type having a housing, a power input shaft, a power delivery shaft, a planetary gearing uni-t in said housing adapted to selectively connect said power input shaft to said power delivery shaft in one of two drive ratios, said planetary gearing unit having a first element driven by said power 9 input shaft, a second element fixed for rotation with said power delivery shaft, and a third element adapted to be selectively connected to said power delivery shaft and to be held against rotation; an improved drive ratio control unit disposed within said housing including a rotatable drum disposed within said housing, a sleeve extension on said drum concentric with said power delivery shaft for connecting said third element to said drum for rotation therewith as a unit and for rotatably supporting said drum on said power delivery shaft, a clutch hub disposed within said housing an-d xed to said power delivery shaft for rotation therewith, engageable and releasable clutch members carried by said drum and said clutch hub, respectively, and rotatable with said drum and clutch hub respectively, a brake hub disposed within said drum and fixed to said housing, engageable and releasable brake members carried by said drum and brake hub respectively, said brake hub forming a chamber adapted to receive luid under pressure, a Belleville spring disposed within said drum, means carried by said duim pivotally retaining the outer periphery of said Belleville spring on said drum, a piston in said chamber having a sleeve portion concentric with said power delivery shaft extending outwardly from said chamber and into cooperating relationship with respect to the inner periphery of said Belleville spring, said Belleville spring being disposed between said clutch and brake hubs and normally effective to engage said clutch members `and release said brake members when said chamber is empty of fluid under pressure, said piston being axially movable in response to fluid under pressure to pivot said spring about its pivotal connection with said drum to thereby release said clutch members and engage said brake members. References Cited in the le of this patent UNITED STATES PATENTS 2,385,517 Hunt Y Sept. 25, 1945 2,600,520 Spase June 17, 1952 2,743,626 Schjolin May 1, 1956 2,757,766 McCroskey et al Aug. 7, 1956 2,861,482 Schjolin Nov. 25, 1958 2,890,773 Martindell June 16, 1959 2,939,558 Schjolin .Tune 7, 1960 1. IN A TRANSMISSION OF THE TYPE HAVING A POWER INPUT SHAFT, A POWER DELIVERY SHAFT AND A PLANETARY GEARING UNIT DISPOSED BETWEEN SAID POWER INPUT SHAFT AND POWER DELIVERY SHAFT INCLUDING A PLANET CARRIER SUPPORTING A PLURALITY OF PLANET PINION GEARS IN MESH WITH A RING GEAR AND A SUN GEAR AND HAVING A DRUM MEMBER ROTATABLE AS A UNIT WITH SAID SUN GEAR; SAID DRUM MEMBER HAVING A FIRST SET OF FRICTION ELEMENTS EFFECTIVE WHEN ENGAGED TO ESTABLISH ONE TRANSMISSION DRIVE RATIO AND A SECOND SET OF FRICTION ELEMENTS EFFECTIVE WHEN ENGAGED TO ESTABLISH A SECOND TRANSMISSION DRIVE RATIO, MEANS NORMALLY EFFECTIVE TO ENGAGE SAID FIRST SET OF FRICTION ELEMENT, INCLUDING A BELLEVILLE SPRING IN SAID DRUM ELEMENT, AND MEANS FOR MOVING SAID BELLEVILLE SPRING TO RELEASE SAID FIRST SET OF FRICTION ELEMENTS AND TO ENGAGE SAID SECOND SET OF FRICTION ELEMENTS.

1960-11-21

en

1963-05-21

US-12106798-A

Tire testing device having an intelligent test head ABSTRACT A tire testing device comprising an air pressure control means for changing the tire pressure of a wheel, a test head and a computer, which prior to and after a change in the air pressure produce an interferogram of the tire surface and convert the interferogram into a modulo-2π image, which for its part is processed to yield a gray value image, and in which from a comparison of the gray value images information about defects present in the tire is obtained, a positioning means for the test head, with which the test head is to be positioned for producing interferograms at a predetermined distance from the tire, and a control means in order to incrementally rotate the wheel by an amount equal to a test segment, when the examination of the preceding test segment is completed, wherein an optical means for producing the interferograms, an electronic control means for the optical means and the air pressure control means are collected together in the test head and in that a sequence control means for the tire checking apparatus and means for evaluating the interferogram are provided in the computer. The invention relates to a tire testing device comprising an air pressure means for changing the tire pressure of a wheel, a test head, a computer, which prior to and after a change in the air pressure respectively with coherent radiation produce an interferogram of the tire surface and convert the interferogram into a modulo-2π image, which for its part is processed to yield a gray value image, and in which from a comparison of the gray value images information about any defects present in the tire is obtained and a control means in order to incrementally rotate the wheel by an amount equal to a test segment, when the examination of the preceding test segment is completed. BACKGROUND OF THE INVENTION The German patent publication 4,231,578A1 discloses a method for determining the structural strength of tires, in the case of which coherent light is shone onto the tire, the radiation reflected by the tire is split up into two beams parts in a dual beam interferometer, in the dual beam interferometer one of the two beam parts is tilted in relation to the other beam part (shearing), in the dual beam interferometer one of the two parts of the radiation is incrementally shifted in phase, a component representing the radiation due to reflectance from the test object, which is split into two beam parts, is recombined in the dual beam interferometer by components forming an image of the surface of the tire with a large aperture, to an electronic image sensor system and the signals at the output of the image sensor system are digitalized and further processed in an image processing system to give a modulo-2π image, and the modulo-2π image is confirmed as an output gray value image. In accordance with the German patent publication 19,502,073 A1 the above mentioned method is further developed by so partially differentiating the output gray value image that a second gray value image is produced, identical to the output gray value image and same is geometrically displaced in relation to the output gray value image in the shearing direction and is modified by a gray value, which is constant over the entire image range and the second gray value image, manipulated in this manner, is subtracted from the output gray value image so that a resulting gray value image is produced, on which any defects in the tire, which may be present, can be recognized. When it is considered that structural damage in car tires, more particularly in the carcass including the belt, may substantially reduce the safety of driving the motor vehicle, it will be seen to be desirable to perform a tire check at regular intervals. In U.S. patent application Ser. No. 09/094,143, which is incorporated herein by reference, there is a proposal for checking a tire by mounting the wheel, which bears the tire to be checked, on a wheel balancing machine and moving a test head up to the tire to be at a predetermined check distance for producing an interferogram. Checking for defects is performed on a first segment of the tire. Then the wheel is rotated further by the balancing machine by an amount equal to a checked segment and the last-mentioned steps are repeated until the entire tire has been checked. The tire testing device accordingly comprises a balancing machine, on which the wheel bearing the tire to be checked is mounted, a positioning means for a test head, with which the test head may be moved up to the tire as far as a predetermined check or test distance for producing an interferogram, and a control means for the balancing machine in order to rotate the wheel by an amount equal to one check segment. In U.S. patent application Ser. No. 09/093,890, which is incorporated herein by reference, there is a proposal for checking a tire by mounting the wheel, which bears the tire to be checked, on a driven roller set. The tire checking comprises an air pressure means for changing the tire pressure and furthermore a testing head and a computer. Furthermore the apparatus comprises at least one driven roller set, onto which the motor vehicle with the wheel, which bears the tire to be checked, is to be driven, a positioning means for the test head, with which the test head can be moved toward the tire to be at a predetermined distance therefrom for producing interferograms and a control means for the roller set in order to rotate same an amount equal to the size of a check segment, when checking of the preceding segment has been completed. SUMMARY OF THE INVENTION One object of the invention is to create a tire checking apparatus, which allows the checking of a tires as part of servicing operations on the wheels of a motor vehicle or as part of a general technical examination of a motor vehicle, which must be performed from time to time, and in this respect the computing and evaluating operations are to be able to be performed as rapidly as possible and with minimum structural the hardware complexity. For this purpose the tire checking apparatus of the invention is characterized in that an optical means for producing the interferograms, an electronic control means for the optical means and the air pressure control means are collected together in the test head and in that a sequence control means for the tire checking apparatus and means for evaluating the interferogram are provided in the computer. Owing to this division up of the optical and electronic units in the test head and in the principal computer (PC) rapid evaluation is achieved with a comparatively small amount of structural and hardware complexity. In accordance with an advantageous development of the tire checking apparatus of the invention the test head comprises a CPU, the electronic control means for the optical means and the air pressure control means and same is connected via an interface with the computer. Accordingly all functions in the test head may be coordinated using but one single serial interface, as for example an RS-232 interface, with the computer means (PC). In accordance with a further advantageous development the tire checking apparatus of the invention, wherein the optical means comprises a video camera, laser diodes and a piezo means, is characterized in that the electronic control means controlled by the computer for the optical means comprises a laser diode control means and a piezo means driver or control means. An other preferred feature of the invention is characterized in that the air pressure control means comprises an air pressure sensor and a solenoid valve driver, the solenoid valve being preferably controllable both as regards the size of its aperture and as regards the time of opening. In this respect it is furthermore an advantage for the air pressure control means to reduce the tire pressure for each checking stage by one step and after the conclusion of checking to return it to the rated pressure. In an advantageous fashion the structural complexity is even further reduced for checking tires in accordance with the invention because a power supply for the electronic units of the test head is integrated in the test head. A further advantageous development of the invention is characterized in that a system bus, preferably an I2 C bus, is provided for connection of the electronic units of the test head. As regards the speed of operation of the test head it is an advantage for the electrical units of the test head to be collected together on a board, which preferably also comprises the power supply. A further advantageous development of the invention is characterized in that a system bus, preferably an I2 C bus, is provided for connection of the CPU with the piezo means control means of the test head. A further advantageous design of the tire checking apparatus of the invention, wherein the wheel drive control means of a balancing machine serve for segment-wise incremental rotation of the wheel, is characterized in that the computer of the tire checking apparatus is integrated in the computer of the balancing machine. In other words the computer performs its function both during balancing of the wheels and also during tire checking. In the case of the above mentioned embodiment it is an advantage for a synchro to be connected with the shaft of the balancing machine to sense further rotation of the shaft and causes the computer to respond thereto, which then turns off the motor drive, when the wheel has been rotated further by one check segment. Such synchros are in any case present in conventional balancing machines so that structural complexity is not increased. A further advantageous design of the tire checking apparatus of the invention, wherein at least one driven roller set of the brake test dynamometer, on which the motor vehicle is to be driven having the wheel, which bears the tire to be checked, serves for segment-wise incremental rotation of the wheel, is characterized in that the computer of the tire checking apparatus is integrated in the computer of the brake test dynamometer. In the above mentioned embodiment of the invention it is an advantage for a sensor roller to be provided, which senses the incremental rotation of the tire and via a synchro causes the computer to respond to such rotation, said computer then turning off the motor drive, when the tire has been further or incrementally turned through one check segment. Accordingly the roller set of the brake test dynamometer is adapted to the requirements of tire checking with a minimum of complexity. Finally an advantageous development of the tire checking apparatus of the invention is characterized in that the motor for the segment-wise incremental rotation of the wheel is driven via a frequency converter, which may be controlled by the computer. A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic plan view of a balancing machine as a first working embodiment of the tire checking apparatus of the invention. FIG. 2 is a front end-on view of the test head of the tire checking apparatus as in FIG. 1. FIG. 3 shows a block diagram of the tire checking apparatus in accordance with the first embodiment. FIG. 4 is a diagrammatic plan view of one roller set of a brake test dynamometer as a second embodiment of the tire checking apparatus of the invention. FIG. 5 is a diagrammatic front end-on view of the apparatus in accordance with FIG. 4. FIG. 6 is a block diagram of the tire checking apparatus according to the second working embodiment. FIG. 7 is a block diagram of the optical and electronic units of a test head. DESCRIPTION OF THE SPECIFIC EMBODIMENTS FIG. 1 shows a balancing machine 2 with a keyboard 4 and a monitor 6, which are arranged on a housing 8. A wheel 10 with a tire 11 is mounted on a shaft 12 of the balancing machine 2 by means of a quick release clamping means 14, which engages a hub of the wheel 10. On the housing 8 of the balancing machine 2 a test head 16 is attached by means of two parallel links or arms 18 and 20. The arm 20 has its one end pivotally mounted on a bracket 22 on the housing 8. A joint 24 connects the arm 20 with the arm 18 and the arm 18 is attached via a joint 26 with the test head 16. Accordingly the test head 16 may be pivoted from a position (not illustrated) wherein it is tucked away on the housing 8, into a checking position (FIG. 1), wherein it is opposite to the side wall of the tire 11 in the checking position. A handle 28 is provided on the test head 16 and possesses a push button switch (not illustrated), by means of which the positioning means (parallel links or arms 18 and 20) may be arrested, when the test head 16 has reached the check or test position. The air pressure means comprises a pressure hose 40 and a valve 42 with an air pressure sensor, the valve 42 being adapted to be mounted on the valve of the tire. In the test head 16 a control means is provided for the air pressure means. The control means in the test head 16 is connected via a cable 30 with the valve, which is designed in the form of a solenoid valve, and with the air pressure sensor, which is integrated in the valve. The valve 42 is able to be set both as regards its aperture (setting the delivery rate per unit time) and also to open and close it so that the change in pressure in the tire may be set both by the degree of valve opening and also the time of valve opening. The test head 16 will be seen in FIG. 2 in a front end-on view and laser diodes 44 will be seen, which serve to produce interferograms. Furthermore two diodes 46 and 48 are provided, which serve to set the distance between the test head 16 and the side wall of the tire 11 during testing. For this purpose the two laser diodes 46 and 48 are so set obliquely in the visible range that the laser beams thereof are at an angle to each other and intersect at that point, which corresponds to the test distance between the test head and the tire's side surface. When the test head 16 is moved toward the tire 11, the checking distance will be reached, when the two laser beams coalesce to one point on the side wall of the tire 11. Lastly an objective 45 of a camera is diagrammatically represented, which takes pictures of the tire to be checked. The speed of rotation of the motor of the balancing machine is so controlled by a variable frequency converter that the motor runs at a relatively low, constant speed of rotation. A synchro on the shaft 12 senses the shaft's speed and produces an output signal, which corresponds to the amount, by which the tire has been turned. The output signal of the synchro is employed in the computer to turn off the drive motor, when the tire has been incrementally turned through one check segment. In the case of the working embodiment illustrated in FIG. 2 a check segment is equal to 1/8 of the overall periphery of the tire so that the tire must be turned seven more times in order to fully check the tire. The test head 16 is connected with a lead for the power supply to the test head and a data line leading to the computing unit. The motor for driving the shaft of the balancing machine and the synchro on the shaft of the balancing machine are also connected with the computing unit, such connecting leads and the computing unit being omitted in order to make the drawing more straightforward. A central computing unit is provided for controlling the functions of the tire checking apparatus, such computing unit being integrated with the computer of the balancing machine so that here as well hardware complexity is not increased. Furthermore the monitor for display of the results of measurement is also employed for balancing and for the checking of the tire, information on both checking operations being displayed on the same monitor. FIG. 3 shows a block diagram of the first working embodiment of the tire checking apparatus. The central computing unit 50, which is illustrated in the form of a PC, conventionally possesses several "com" ports. A mouse 52 is connected with the com 1 port. The com 2 port is employed for a balancing machine control means 54, which essentially comprises the control for the drive motor of the balancing machine and is also responsible for incremental rotation segment by segment of the wheel during the checking thereof. The test head 16 is connected with the com port 3, while the video camera present in the test head is connected via a lead 56 with the frame grabber 58 in the computing unit 50. The design of the test head 16 will be described in more detail infra, while the connections for the keyboard and the monitor of the computing unit 50 are omitted in order to make the drawing more straightforward. The manner of functioning of the tire checking apparatus is as follows. Firstly the wheel bearing the tire to be checked is mounted on a balancing machine, the shaft of the balancing machine being able to be rotated under the control of a computer both for wheel balancing and also for performing tire checking at different speeds of rotation. The next step is for a test head to be moved toward the tire as far as a predetermined check distance for producing interferograms and it is arrested in this position. After mounting the tire on the balancing machine the air pressure valve is connected with the tire. Prior to performing the first check sequence the wheel-specific data and, respectively, the data for incremental rotation of the shaft of the balancing machine, as for example the duration of drive at constant speed of rotation, which depend on the wheel dimensions are supplied to the computer or gotten from a look-up table. Then tire checking is performed on a first check segment of the tire in accordance with the method as initially mentioned. After the first check segment has been examined, the wheel is incrementally turned on further by the size of a check segment using the shaft of the balancing machine, the shaft of the balancing machine being controlled via a computer and in a manner dependent on output signals of a synchro on the shaft of the balancing machine. When the next segment of the wheel has been brought into position, the test head is activated in order to check the next segment. Thereafter as many check sequences and as many incremental rotational movements are performed as are necessary for checking the entire tire. At each check sequence there is, as already indicated, a reduction in pressure between a first series of interferograms and a second series, such reduction in pressure also being controlled by the computing unit. The reduction in pressure is accordingly performed in steps, the pressure starting at the rated pressure being reduced by one step in each check sequence. After conclusion of checking the air pressure the tire is then returned to the rated pressure, the valve and the control means connected with same also being employed. With reference to FIGS. 4 through 6 a second working embodiment of the tire checking apparatus of the invention will now be described. A roller set with two rollers 64 and 66 of a brake test dynamometer 62 are illustrated of which the roller 64 is driven by a motor 68. The other roller 66 free wheels. Between the rollers of the roller set a respective sensor roller 76 is arranged. The roller sets and the drive motors of the brake test dynamometer are arranged in a recess in the floor. A vehicle is driven in the direction of the arrow F onto the roller sets so that for instance its front wheels are arranged in the two roller sets. In FIG. 4 a front wheel 78 of a motor vehicle is indicated, whose tires are to be checked. FIG. 4 furthermore shows a front wheel 80, which has a smaller diameter than the wheel 78 and belongs to another motor vehicle. The different sizes of the wheels 78 and 80 only serve to explain the manner of functioning of this embodiment of the invention. A test head 90 is mounted by means of two pivot arms 94 and 96 on a Z column 92 able to be moved in the direction of the arrow Z in FIG. 5 vertically. Accordingly the test head 90 may be readily moved into the position with the correct check distance from the side surfaces of the tire 78. Then the pivot arms 94 and 96 and also the Z column 92 are arrested. The air pressure means comprises, as in the first embodiment, a pressure hose and a solenoid valve, which may be mounted on the tire valve. The valve is able to be set both as regards its aperture (setting the delivery amount per unit time) and also to open and close it so that the change in pressure in the tire may be set both by the degree of valve opening and also the time in which the valve is open. The air pressure control means in the test head 90 is connected via a cable (not illustrated) with the air pressure sensor and the solenoid valve. A handle 97 is provided on the test head 90 and with it the test head may be moved manually along the three axes until the check position has been reached. When the check position is reached, the arresting means of the three slides are activated using a push button switch, which is provided on the handle 97. The test head 90 arranged on the column 92 is represented in FIG. 5 in a front end-on view and laser diodes 98 will be seen, which are employed for producing the interferograms. Furthermore two diodes 100 and 102 are provided, which serve to set the correct distance between the test head 90 and the side wall of the tire 78. For this purpose the two laser diodes 100 and 102 are so set obliquely in the visible range that the beams thereof are at an angle to each other and intersect at that point, which corresponds to the test distance between the test head and the tire's side wall. When the test head 90 is moved toward the tire 78, the check distance will be reached, when the two laser beams form one point on the side wall of the tire 78. Lastly an objective 104 of a camera is diagrammatically represented, which takes pictures of the tire to be checked. The speed of rotation of the motor 68 is so controlled by a variable frequency converter (not illustrated) from the central computing unit of the tire checking apparatus that the motor runs at a relatively low, constant speed of rotation. The sensor roller 76 engages the tire in order, via the synchros to produce an output signal, which is equal to the amount by which the tire has been turned. The output signal of the synchros of the sensor roller 76 is employed in the computer to turn off the drive motor when the tire has been incrementally rotated through one check segment. In the case of the working embodiment illustrated in FIG. 5 a check segment is equal to 1/8 of the overall periphery of the tire so that the tire must be turned seven more times in order to fully check the tire. The position of the test head 90' is indicated in phantom lines and provided with the reference numerals 90', 94' and 96'. As shown in FIG. 4 it is possible to move the test head 90 into position at the correct distance both in the case of large wheels such as the wheel 78 and also in the case of small wheels such as the wheel 80. A central computing unit is provided for controlling the functions of the tire checking apparatus, such computing unit being integrated with the computer of the balancing machine so that here as well hardware complexity is kept low. Furthermore the monitor for display of the results of measurement is also employed for the brake test and for the checking of the tire, information on both checking operations being displayed on the same monitor. The manner of operation of the above described working embodiment of the tire checking apparatus of the invention on a brake test dynamometer is analogous to the manner of operation of the tire checking apparatus of the invention on a balancing machine as was described supra. The difference resides in that the two roller sets of a brake test dynamometer may be run under the control of the computer both for performing brake testing and also for performing tire testing with different speeds of rotation. FIG. 6 shows a block diagram of the second working embodiment of the tire checking apparatus. The central computing unit 50, which is represented as a PC, conventionally possesses a plurality of "com" ports. A mouse 52 is connected with the com 1 port. The com 2 port is connected with a brake test dynamometer control means 93, which essentially comprises the control for the drive motor of the brake test dynamometer and is also responsible for incremental rotation of the wheel during tire checking. The test head 90 is connected with the com port 3, while the video camera present in the test head is connected via a lead 105 with the frame grabber 58 in the computing unit 50. The design of the test head 90 will be described in more detail infra, while the connections for the keyboard and the monitor of the computing unit 50 are omitted in order to make the drawing more straightforward. A second test head 91 is connected by means of a lead 106 with the frame grabber 58. In this working embodiment the frame grabber 58 is employed for processing the output signals of both test heads 90 and 91. FIG. 7 shows a block diagram of the optical and electronic units of the test head, as for example the test head 16 or the test head 90 and 91. In the test head 16 an optical means 110 is provided for producing the interferograms, which comprises a video camera 112, the laser diodes and as piezo means 116. In the optical means the light diffusely reflected back from the tire goes to the objective of a video camera, the light passing through a Michelson interferometer, in which the light beam is firstly split up at a ray splitter into two beam parts. After reflection at the mirrors the beam parts are recombined prior to passing to the objective of the video camera 112. In the Michelson interferometer, using a setting element it is possible for one image part to be tilted in relation to the other image part. This leads to two mutually shifted images of the tire side wall. With the aid of a piezo element it is possible for the second beam part to be shifted in minimum steps. This function serves for determining the phase relationship of the diffusely reflected light and accordingly for determination of deformation. The signal of the video camera 112 (CCD camera) is supplied via the BNC connection 114 (FIG. 7) to the PCI frame grabber 58, which is provided in the computing unit 50. An electronic control means for the optical means 110 comprises a laser diode control means 116 and a piezo control means 118. The air pressure control means includes an air pressure sensor 120 and a solenoid valve drive 122. Lastly FIG. 7 shows a power supply 124 for the electronic units in the test head. The electrical units are controlled by a computer CPU 126, which is connected by means of an RS-232 driver 128 with the computing unit (PC) 50, in which a sequence control means of the tire checking apparatus is provided together with means to evaluate the interferograms. Each of the test heads 16, 90 and 91 operates as an autonomic system. Control is taken over from the computing unit 50 through a serial interface and the RS-232 driver 128. Accordingly the piezo means 116 for producing special images (wavelength shift), the laser diodes 44 and 98 for illuminating the tire side walls, the laser diodes 46, 48, 100 and 102 for setting the distance of the test heads from the tires, the video camera 112 for producing an image, the air pressure sensor 120 for checking the tire pressure, the solenoid valve driver 122 for the control of the solenoid valve 42 and a serial interface are to be operated via the driver 128. The system is so designed that via one serial system bus 117, preferably an I2 C bus, the individual component groups may be controlled via the CPU 126. Safety-related elements of the tire checking apparatus, as for instance the condition that the illuminating laser diodes, for instance the diodes 44, may only be turned on when a tire is opposite to the test head, are consequently not under the control of the computing unit 50, since such computing unit elements are ensured by the software and hardware independently of the computing unit 50. Owing to the serial system architecture it is possible also for future options to be adopted without any problems. An expansion of up to a maximum of 128 component groups is possible. For example LCD displays, infrared remote control elements, LED display means, relay outputs, semiconductor outputs, additional analog and digital output and furthermore key areas are possible. Owing to the system architecture it is more especially possible to operate all component groups in the test head, including the air pressure control, using a single interface. Each test head is connected by means of a commercially available equipment cable with the principal power supply. It can operate in a voltage range of 90 to 260 V and at a frequency of 40 to 400 Hz without changing means. Internally following the power supply 124 all component groups including the video camera 112 and the piezo means 116 are supplied with 12 V DC. The system is accordingly safe to touch. The high voltage for driving the piezo means 116 is locally produced in the piezo control means. The component groups of the individual system component are connected together by a flat cable in bus technology, that is to say via the system bus 117. Wiring is accordingly extremely simple. A further advantageous feature is possible if the power supply 124 and the remaining component groups 116, 118, 120, 122, 126 and 128 are collected together on one board, a system bus, preferably a I2 C bus only being provided for driving a piezo amplifier in the control means 188 for the piezo means. This means that there is a further simplification of the tire checking apparatus of the invention as regards structural and hardware complexity. It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those skilled in the art upon reviewing the above description. Those skilled in the art will recognize as an equivalent or alternative method of tire testing and combining a tire testing machine with a wheel balancing machine. The scope of the invention should, therefore, be determined not as reference to the above description, but should instead be determined with reference to the apended claims along with the full scope of equivalence to which such claims are entitled. What is claimed is: 1. A tire testing device comprising:an air pressure means for changing the tire pressure of a wheel, a test head and a computer, which prior to and after a change in the air pressure respectively with coherent radiation produce an interferogram of the tire surface from which the information about defects present in the tire is obtained, a positioning means for the test head, with which the test head is to be positioned for producing interferograms at a predetermined distance from the tire, and a control means in order to incrementally rotate the wheel by an amount equal to a test segment, when the examination of the preceding test segment is completed, wherein (a) an optical means for producing the interferograms, an electronic control means for the optical means and the air pressure control means are collected together in the test head, wherein (b) the test head comprises a CPU which is provided for the electronic control of the optical means and the air pressure control means and is connected via an interface with the computer, wherein (c) a system bus is provided for connecting the electronic units of the test head, and wherein (d) a sequence control means for the tire testing device and means for evaluating the interferogram are provided in the computer. 2. The device as claimed in claim 1, wherein the optical means comprises a video camera, laser diodes and a piezo means, wherein the electronic control means controlled by the computer for the optical means comprises a laser diode control means and an piezo means control means. 3. The device as claimed in claim 2, wherein a system bus is provided for connecting the CPU with the piezo means control means of the test head. 4. The device as claimed in claim 3, wherein the system bus is an 12 C bus. 5. The device as claimed in claim 1, wherein the wheel drive control means of a balancing machine serves for segment-wise incremental rotation of the wheel, wherein the computer of the tire testing device is integrated in the computer of the balancing machine. 6. The device as claimed in claim 5, wherein a synchro is connected with the shaft of the balancing machine, which senses incremental rotation of the balancing machine and feeds rotation information to the computer, which halts further rotation of the motor drive when the wheel has turned by one test segment. 7. The device as claimed in claim 5, wherein a motor for segment-wise rotation of the wheel is provided and operated using a frequency converter which may be controlled by the computer. 8. The device as claimed in claim 1, wherein the air pressure control means includes a pressure sensor and a solenoid valve driver. 9. The apparatus as claimed in claim 1, comprising a valve which is controllable both as regards the size of its aperture and as regards the time of opening. 10. The device as claimed in claim 9, comprising air pressure control means to control the pressure in the tire, the tire pressure being reduced for each checking step by one step and after the conclusion of checking being returned to the rated pressure. 11. The device as claimed in claim 1, wherein a power supply is integrated in the test head for supplying power to electronic units of the test head. 12. The device as claimed in claim 1, wherein the system bus is an 12C bus. 13. The device as claimed in claim 1, wherein any electronic units of the test head are mounted together on one board. 14. The device as claimed in claim 1, wherein any electronic units of the test head as well as a power supply integrated in the test head for supplying power to the electronic units of the test head are mounted together on one board. 15. The device as claimed in claim 1, wherein at least one driven roller set of a brake test dynamometer, on which a motor vehicle is to be driven having the wheel, which bears the tire to be checked, serves for segment-wise incremental rotation of the wheel, wherein the computer of the tire testing device is integrated in the computer of the brake test dynamometer. 16. The device as claimed in claim 15, comprising a sensor roller which senses the incremental rotation of the tire and via a synchro causes the computer to respond to such rotation, said computer then turning off the motor drive when the tire has been further through one test segment. 17. The device as claimed in claim 15, wherein a motor for segment-wise rotation of the wheel is operated using a frequency converter, which may be controlled by the computer.

1998-07-21

en

2000-03-28

US-36652182-A

Binding tool ABSTRACT There is disclosed a binding tool for fastening and cutting off a band such as a plastic binding band after relaxing the pulling force which includes a pistol-type body, a trigger part subjected to a returning force, a pulling member slidably disposed in the body, a sliding member slidably disposed along a slot of the pulling member and connected to the trigger part through a pivoted connecting member, a push-up member having a tapered surface slidably contacting a tapered surface of the sliding member and a surface slidably contacting an inner surface of a rear end portion of the pulling member. The sliding contact between the tapered surfaces is released when forces imposed reaches a predetermined value. The tool includes a rocking member provided at a tip with a cutter, and a push-down member having a sloped surface slidably contacting a sloped surface formed in the under portion of the pulling member, a face slidably contacting the upper surface of the rocking member, and a face coming into slidable contact with a pressing surface provided on the under side of the sliding member after release from contact of the tapered surfaces of the sliding member and push-up member. FIELD OF THE INVENTION This invention relates to a binding tool wherein such binding band as a cable tie made of a plastic for binding electric cables and other materials is fastened as tensioned under a predetermined strength and is then cut off at the free end under a reduced tension by once relaxing the pulling force just before the band is cut off. DESCRIPTION OF THE PRIOR ART Generally pistol-type binding tools are known. A pistol-type binding tool provided with a pulling mechanism and cutting mechanism is disclosed in the gazette of Japanese Patent Publication No. 16833/1966 filed by claiming the priority right based on U.S. patent application Ser. No. 474,563 of July 26, 1965 of Jack E. Caveney et al. and a pistol-type binding tool provided with a pulling mechanism and cutting mechanism so that the pulling mechanism will be driven through an operating mechanism without contacting the cutting mechanism until a fixed tension is obtained and will be driven through a toggle link device contracting against the cutting mechanism when the fixed tension is obtained to operate the cutting mechanism is disclosed in the gazette of Japanese Patent Laid Open No. 116399/1977 filed by claiming the priority right based on U.S. patent application Ser. No. 656,489 of Feb. 9, 1976 of Joseph Romeo Paradis. These conventional binding tools have defects that, generally, the band will be cut off at the free end at the maximum peak of the band fastening tension and will be pulled out of a socket part containing a ratchet mechanism formed at one end of the band as engaged by the pulling cutting shock or will be so abnormal in the engagement with the socket part as to be likely to be disengaged even if not pulled out. The present invention has it as an object to engage a band with a socket part by once momentarily relaxing the pulling force just before cutting the band after fastening and pulling it to prevent the return of the band when cut and to securely bind it. Another object of the present invention is to make the remaining length after cutting the band adjustable to further securely engage the band. Further, another object of the present invention is to make the manufacture easy with a simple structure and to improve and rationalize the workability with a light weight. SUMMARY OF THE INVENTION The present invention relates to a binding tool comprising a trigger part given a returning force and connected to a pistol-type body capable of being fitted with a pad plate at the tip, a sliding member operatively connected to the trigger part, a push-up member taper-contacting the rear end portion of the sliding member and given a push-up force, a pulling member connected to the push-up member and provided at the tip with ratchet pawls engaging the free end portion of a binding band, a rocking member provided at the tip with a cutter so as to slide with the above mentioned pad plate and a push-down member slidable on the upper surface of the rear end portion of the rocking member and having a sloped surface, the push-down member being pressed and pushed down between the above mentioned sliding member and tensioning member. In one mode of the present invention, the above mentioned push-down member is arranged with a gap from the pressing surface of the sliding member and in tapered contact with the pulling member. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention is shown in the drawings in which: FIG. 1 is a perspective view of a vicinity of a tip portion; FIG. 2 is a general sectioned view on line A--A in FIG. 1; FIG. 3 is a general sectioned view on line B--B in FIG. 1; FIG. 4 is an elevation of a pad plate to be fitted to the tip; FIG. 5 is a magnified view of a part of the tip portion in FIG. 3; FIG. 6 is a perspective view showing the relation between a sliding member and push-up member; FIG. 7 is a binding band fastening state explaining view; FIGS. 8A to 8D are explanatory views showing operating states. DETAILED DESCRIPTION OF THE INVENTION To further explain the embodiment of the present invention with reference to the drawings, the reference numeral 1 denotes a pistol-type body in which a pad plate 2 can be fitted to the tip and a trigger part 4 given a returning force by a resilient, for example, plastic spring 3 is pivoted with a pin 5 as a fulcrum. As exemplified in FIGS. 4 and 5, the pad plate 2 is provided with a hole portion 2A passing the free end portion of the binding band. The upper inside of the hole portion 2A may be blade-shaped. Further, by varying the thickness of the pad plate 2 as indicated by the two-point chain lines, the cut remaining length projecting out of the socket part of the band when cut can be adjusted. As exemplified in FIG. 2, the plastic spring 3 is set as somewhat compressed and deformed within the body 1 and contacts at the tip with the trigger part 4 as strengthened in the returning force. Further, the rear end portion of the plastic spring 3 is split. As in the illustration, both end portions of the spring 3 adjacent the split are provided with tapered parts contacted with each other so that a force strongly pushing up the tapered surfaces will be given by the elastic deformation and will reinforce the force of returning the trigger part 4 to the original position. By the way, in case the deformation of the plastic spring 3 exceeds tapered contact surface, the elastically deforming force of the contact part will not act but only the inherent elastically deforming force of the plastic spring 3 will act. That is to say, by making the contour of the plastic spring 3 as mentioned above, the returning force of the trigger part 4 can be averaged. Further, the trigger part 4 is pivoted to one end of a connecting member 6 by the pin 5 and the connecting member 6 is pivoted at the other end to a sliding member 8 sliding within the body 1 by a pin 7. A tapered surface 8A is formed in the rear end portion of the sliding member 8 and is borne by a push-up member 9 having at the top end a tapered surface 9A contacting the tapered surface 8A and given a push-up force by a spring 10. This spring 10 is disposed between an adjusting screw 11 and a nut 12 screwed to the tip of it so that, by rotating the adjusting screw 11, the nut 12 will move vertically and the strength of the push-up force of the spring 10 will be able to be adjusted. Further, the above mentioned push-up member 9 and nut 12 are borne by the rear end portion 13A of a pulling member 13 moving within the body 1. The pulling member 13 is provided in the tip portion with ratchet pawls 15 having a spring 14 and a locking part 16 opposed to them. The locking part 16 is a lateral projection integrally formed on pulling member 13. Further, a rocking member 18 pivoted by a pin 17 is disposed below the above mentioned pulling member 13 and is provided at the tip with a cutter sliding on the inner surface of the pad plate 2 fitted to the tip of the body 1 and with a compression spring 23. On the upper surface of the rear end portion of the rocking member 18, a push-down member 20 having a sloped surface 20A is arranged movably vertically and slidably on the rocking member 18 and has a gap from a pressing surface 8B between the pressing surface 8B of the above mentioned sliding member 8 and a sloped surface 13B of the pulling member 13 and a sloped surface 20A is contacted with the sloped surface 13B formed in the pulling member 13. In the drawings, the reference numeral 21 denotes a material to be bound, 22 denotes a binding band, 22A denotes a socket part and 22B denotes a free end portion. The operation of the present invention shall be described in the following. When the binding band 22 is wound on such materials 21 as, for example, electric cables and in the free end portion 22B is inserted through the hole portion 2A of the pad plate 2 as in FIG. 7 and FIGS. 8A, 8B and the trigger part 4 is pulled as indicated by the arrow in FIG. 2, the rear end portion 13A of the pulling member 13, that is, the pulling member 13 will be moved away from the tip of the body 1 as in FIG. 8A through by means of the connecting member 6 and sliding member 8 and thereby the ratchet pawls 15 provided in the tip portion of the pulling member 13 will engage the free end portion 22B of the band 22 between the pawls and the locking part 16 by the action of the spring 14. When the trigger part 4 is further pulled, the force of the pulling member 13 to pull the band 22 and the force of the push-up member 9 subjected to the force of the spring resisting so as not to be disengaged from the tapered surface 8A of the sliding member 8 will be unbalanced with each other, the push-up member 8 will retreat, the movement of the pulling member 13 will stop and the sliding member 8 will somewhat move. In such case, if a tensile stress acts on the band 22, the pulling member 13 will be momentarily somewhat pulled back, the band will perfectly engage with the socket part, the gap between the pressing surface 8B of the sliding member 8 and the push-down member 20 will contract and the stress acting on the band 22 will be relaxed. When the trigger part 4 is further pulled, the pulling member 13 will not move, the sliding member 8 will move, the pressing surface 8B will contact the push-down member 20 and the push-down member 20 will be compressed between the sliding member 8 and pulling member 13. However, as the push-down member 20 and pulling member 13 are contacted with each other in the tapered parts, the compressing force will act to push-down the push-down member 20 (FIG. 8B), therefore the rocking member 18 will be pushed down in the rear end portion, will rock against the compression spring 23 with the pin 17 as a fulcrum, will push up the cutter 19 at the tip and will slide the blade-shaped portion of the pad plate to cut off the band 22 in the free end portion 22B (FIG. 8C). When the trigger part 4 is released, the rocking member 18 will push up the push-down member 20 to return to the original state by the action of the compression spring 23, all the actions will return to the original states due to the spring 3 and the cut free end portion 22B of the band 22 will be discharged out of the tip (FIG. 8D). By the way, by properly determining the thickness of the pad plate 2 at the tip of the body 1, the band 22 can be normally and positively engaged with the socket part 22A with some space in the projection out of the socket part 22A. Further, in case the upper inside of the hold portion 2A of the pad plate 2 is blade-shaped, the cutter 19 will be able to be expected to operate more smoothly to cut accurately. As described above, according to the present invention, as the pulling force is once relaxed just before the band is cut off after being fastened and pulled, the band will be prevented from returning and will be bound positively. Further, as the cut portion of the free end of the band can be positively projected out of the socket part, the operation will be able to be improved and rationalized. I claim: 1. A binding tool for fastening and cutting off a band after relaxing of a pulling force comprising:a pistol-type body capable of being fitted with a pad plate at the tip; a trigger part subjected to a returning force; a pulling member slidably disposed in said body and having a tip provided with ratchet pawls and a locking part opposite the pawls; a sliding member slidably disposed along a slot of said pulling member and connected to said trigger part through a pivoted connecting member and having a tapered surface near its rear end portion; a push-up member having a tapered surface at the top, said surface being slidably contacted with said tapered surface of said sliding member and having a surface slidably contacting an inner surface of the rear end portion of said pulling member, the contacting of said tapered surfaces of said push-up member and said sliding member being released when forces imposed reach a predetermined value; a rocking member provided at the tip with a cutter and pivoted to said body; and a push-down member having a sloped surface slidably contacted with a sloped surface provided in the lower portion of said pulling member, a face slidably contacting the upper surface of said rocking member, and a face coming into slidable contact with a pressing surface provided at an under side of said sliding member after releasing from contact the tapered surfaces of said sliding member and said push-up member. 2. A binding tool according to claim 1, wherein said trigger is forwardly biased by a plastic spring, said push-up member is adjustably biased perpendicular to the axis of said pulling member by a spring, and said rocking member is biased by a spring.

1982-04-07

en

1983-10-18

US-67853996-A

Polarimetrical processing detection circuit for radar receiver ABSTRACT This target detection polarimetrical processing circuit comprises, in parallel, a polarimetrical CFAR detector provided with a target detection output, a polarimetrical clutter-rejection filter associated with a CFAR detector provided with a target detection output and a bank of polarimetrical filters associated with CFAR detectors provided with target detection outputs, and an &#34;OR&#34; type logic circuit combining the different target detection outputs and a selection circuit activating the polarimetrical clutter-rejection filter and disabling the bank of polarimetrical filters when the degree of polarization of the clutter exceeds a certain threshold and conversely disabling the polarimetrical clutter-rejection filter and activating the bank of polarimetrical filters when the degree of polarization of the clutter is below said threshold. The circuit makes use of the complementary features of the polarimetrical clutter-rejection filter, the polarimetrical CFAR detector and a bank of polarimetrical filters to carry out an optimal target detection whatever the degree of polarization of the clutter, the signal-to-clutter ratio and the instantaneous polarization of the target echo. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains to operations for the polarimetrical processing of the reception signal of a radar with a view to improving the sensitivity of detection of targets. 2. Description of the Prior Art In order to improve the sensitivity of detection of targets in radar technology, it has been proposed to take the polarization of the back-scattered field into consideration, either by using radar receivers having two parallel channels with horizontal and vertical crossed polarizations or right-hand and left-hand circular crossed polarizations, or by using transmitters that transmit simultaneously or successively in two orthogonal polarizations with modulation encoding operations to separate the transmitted signals and seek out the polarization having the optimum signal-to-noise ratio. In these techniques using polarimetrical radars, there are two reception channels available, A and B, in two orthogonal polarizations on which there are available complex video signals ZA and ZB resulting from the standard operations, conducted in parallel in both channels, of frequency transposition, matched filtering and possibly frequency processing which may be Doppler or MTI (mobile target indication) processing. The first step of the usual polarimetrical processing operations always consists of the assessment, made in one way or another, of the degree of polarization and the type of polarization of the resolution cell tested (the range and speed gate taken into consideration) and its environment. This assessment is done, for each resolution cell, by determining the components of the Stokes vector G with four real components g0, g1, g2, g3 that are defined by the expressions: ##EQU1## the component go representing the energy of the received signal and the components g1, g2 and g3, normed by the component g0 representing the coordinates of a vector whose modulus p: ##EQU2## represents the degree of polarization and whose orientation in the Poincare sphere represents the type of polarization. If the reception channel A is a left-hand circular polarization and the reception channel B is a right-hand circular polarization, the coordinate g2 defines a diameter on the Poincare sphere that is oriented positively towards the point of the equator corresponding to a horizontal polarization and negatively towards the point of the equator corresponding to a vertical polarization and the coordinate g1 defines another diameter of the Poincare sphere orthogonal to the preceding one, oriented positively towards the polar point corresponding to a left-hand circular polarization and negatively towards the polar point corresponding to a right-hand circular polarization. The location, further within the interior of the Poincare sphere or further away from the interior of the Poincare sphere, of the point with coordinates g1, g2, g3 normed by the component g0, gives the degree of polarization. The closer the point is to the surface of the sphere, the greater is this degree of polarization. The polarimetrical environment of the clutter is assessed by determining the components of the Stokes vector in the resolution cells neighboring the resolution cell under analysis for the target detection. These components are determined either along the distance axis if the operation relates to the mobile echoes selected by Doppler processing or along the temporal axis, from antenna rotation to antenna rotation, in the case of a map of clutter designed for the detection of slow targets or targets seen athwart, and the average of the components is taken. To reveal the echoes of the polarimetrical environment of the clutter, there are essentially three known techniques. These are the techniques of: - the polarimetrical rejection filter, the bank of polarimetrical filters, and the polarimetrical CFAR (constant false alarm rate) detector. A polarimetrical filter carries out a linear combination of the complex signals ZA and ZB received on the two orthogonally polarized ports of the receiver of the radar. In this operation, the antenna is provided with a virtual reception polarization e that is tuneable at will by action on the complex coefficients of the linear combination chosen: the signal Z at output from the filter is none other than the component of the incident field along the axis of polarization defined by e. By using the Stokes vector H with components g0, g1, g2, g3 ! corresponding to the back-scattered field in the resolution cell under analysis and by assigning the notations 1, α, β, γ! to the components of the unitary Stokes vector H corresponding to the polarization defined by e, it can be shown that the energy of the signal at output of a polarimetrical filter corresponds to the scalar semi-product F of the vector G multiplied by the vector H: ##EQU3## This output signal energy is extracted by a modulus extraction circuit processing the components in phase and in quadrature of the complex output signal of the polarimetrical filter, as happens when there is no polarimetrical filter. It is compared with a detection threshold set as a function of the requisite probability of a false alarm Pfa, to detect the presence of a target. A polarimetrical filter taken in isolation, quite like a mono-polarization antenna, has a "blind" polarization: an echo with a polarization orthogonal to that of the filter or to that of the antenna, whatever its intensity, does not give rise to any signal at output. Depending on the viewpoint adopted, whether it is sought to eliminate spurious signals or detect targets, this may be an advantage or a drawback. To obtain a polarimetrical rejection filter, it is enough to choose a polarization e for the polarimetrical filter that is orthogonal to the estimated polarization of the clutter. If gf0, gf1, gf2, gf3 ! are the components of the Stokes vector Gf of the clutter which are, as seen here above, the mean components of the Stokes vectors of the back-scattered field in the resolution cells neighboring the cell under analysis, and if pf is the degree of polarization of the clutter: ##EQU4## This amounts to adopting the following values for components of the unitary Stokes vector H of the polarimetrical rejection filter: ##EQU5## since two orthogonal polarizations are represented on the Poincare sphere at two diametrically opposite points. The mean energy Ff at output of the polarimetrical filter for a resolution cell containing only clutter is then equal to: ##EQU6## which can also be written: ##EQU7## This energy is minimal and corresponds to half of the energy of the non-polarized component of the clutter for this energy of the non-polarized component is equally distributed between the polarization e of the filter and the orthogonal polarization. In an environment of non-polarized clutter (pf =0), a polarimetrical rejection filter is inoperative and the residual energy of the clutter then becomes independent of the choice of the filtering polarization e and reaches half of the total energy conveyed by the two ports of the antenna. The usefulness of the polarimetrical rejection filter increases with the degree of polarization of the clutter. However, the polarimetrical rejection filter has the drawback of being blind to the targets that back-scatter a field having the same polarization as the clutter. A bank of polarimetrical filters consists of a parallel grouping of several polarimetrical filters with permanently fixed polarizations, chosen so as to be evenly distributed on the Poincare sphere, each of these polarimetrical filters being followed by a modulus extractor and a CFAR or constant false alarm rate detector. In addition, the bank of polarimetrical filters includes an "OR" type logic circuit combining the outputs of the different detectors and performing the logic merger of the detections, namely the elementary presence of targets. The totalizing of the cases of detection or elementary presence of targets performed by the different detectors is equivalent to the selection of the polarimetrical filter that gives the optimum signal-to-clutter ratio while a polarimetrical rejection filter only minimizes the level of clutter. The bank of polarimetrical filters is thus an approximate embodiment of the "matched polarimetrical filter". The greater the number of polarimetrical filters used and the greater the extent to which they give a representative and dense sampling of the space of the polarizations, the better is the approximation. As the degree of polarization of the clutter increases, the matched polarimetrical filter tends to be merged with the polarimetrical rejection filter. This fact can be understood easily by taking the extreme case of the entirely polarized clutter (pf =1) for which the residual energy of the clutter at output of the polarimetrical rejection filter is zero and the signal-to-clutter ratio is infinite. A bank of polarimetrical filters is therefore well suited to types of clutter with little or medium polarization. Furthermore, it is also appropriate for weak useful echoes. However, since the residue of clutter at output of a polarimetrical rejection filter is very sensitive to the precise adjustment of the "blind" polarization to the polarization of the clutter, it can be seen that, in a highly polarized environment, a bank of polarimetrical filters makes for a cumbersome solution. For, with the need to ensure a sufficiently fine meshing of Poincare sphere polarizations, the bank must contain a large number of filters. Conceptually, the polarimetrical CFAR detector has the following elements: a base-changing circuit acting on the vector signal, whose components are the signals ZA, ZB present at the two reception ports of the radar, to express this vector signal with two new components EP and EQ in the base of the inherent polarizations P and Q of the clutter (polarizations parallel and orthogonal to that of the clutter), two weighting circuits that are each positioned on one output channel of the base-changing circuit and carrying out a 1/√λ, and 1/√μ weighting respectively, conversely proportional to the square root of the estimated energy of the clutter in the channel considered, P and Q respectively, two modulus extraction circuits, one summation circuit connected to the output of the two modulus extraction circuits and one CFAR detector. The base-changing circuit is formed by two polarimetrical filters, one with the polarization of the clutter and the other with a polarization orthogonal to that of the clutter, the latter filter being then a polarimetrical clutter-rejection filter. The parameter λ that plays a part in the weighting of the channel coming from the polarimetrical filter with the polarization of the clutter is proportional to the estimated energy of the clutter at output of this polarimetrical filter: ##EQU8## for the unitary Stokes vector L of this polarimetrical filter with polarization identical to that of the clutter has the following components: ##EQU9## and the mean energy of the clutter at output of this filter verifies: ##EQU10## The weighting parameter p for its part is equal to: ##EQU11## since it has been seen that the mean energy of clutter at output of a polarimetrical filter with polarization orthogonal to the clutter is equal to: ##EQU12## At outputs of the weighting circuits, the incident polarized clutter is converted into a non-polarized phenomenon. A processing operation of this kind does not give rise to any blind polarization. Provided that it is strong enough, a target echo having the same polarization as the clutter may be detected for it appears on the processing channel P. It can be shown in fact that the polarimetrical CFAR detector is optimal for the high signal-to-clutter ratios. Besides, unlike in the case of the rejection filter, this processing remains efficient in a non-polarized environment. In short, the efficiency of the polarimetrical processing operations that are known depends on the degree of polarization of the clutter and the energy of the useful echo. This means that there is no processing operation that is optimal in all cases of clutter. SUMMARY OF THE INVENTION The present invention is aimed at overcoming this drawback. An object of the invention is a target detection polarimetrical processing circuit for radar receivers comprising at least, in parallel, a polarimetrical CFAR detector provided with a target detection output and a polarimetrical clutter-rejection filter associated with a CFAR detector provided with a target detection output, and an "OR" type logic circuit combining the target detection outputs of the polarimetrical CFAR detector and of the CFAR detector. Advantageously, the target detection polarimetrical processing circuit comprises, in parallel, a polarimetrical CFAR detector provided with a target detection output, a polarimetrical clutter-rejection filter associated with a CFAR detector provided with a target detection output and a bank of polarimetrical filters associated with CFAR detectors provided with target detection outputs, and an "OR" type logic circuit combining the different target detection outputs and a selection circuit activating the polarimetrical clutter-rejection filter and disabling the bank of polarimetrical filters when the degree of polarization of the clutter exceeds a certain threshold and conversely disabling the polarimetrical clutter-rejection filter and activating the bank of polarimetrical filters when the degree of polarization of the clutter is below said threshold. BRIEF DESCRIPTION OF THE DRAWINGS Other characteristic and advantages of the invention shall emerge from the following description of an embodiment given by way of an example. This description shall be made with reference to the drawings, of which: FIG. 1 gives a schematic view of a processing circuit carrying out the function of a polarimetrical clutter-rejection filter positioned upline with respect to a CFAR detector; FIG. 2 gives a schematic view of another processing circuit carrying out the function of a bank of polarimetrical filters associated with CFAR detectors whose outputs are coupled by an "or" type logic circuit; FIG. 3 gives a schematic view of another processing circuit carrying out the function of a polarimetrical CFAR detector; FIGS. 4 and 5 are graphs of curves of probability of detection as a function of the types of polarimetrical processing; and FIG. 6 gives a schematic view of a polarimetrical processing circuit according to the invention. MORE DETAILED DESCRIPTION The polarimetrical processing circuit of FIG. 1, which carries but the function of a polarimetrical clutter-rejection filter positioned upline with respect to a CFAR detector comprises the following elements at input: a circuit 10 for determining components of the Stokes vector G for each resolution cell of the radar, followed by a circuit 11 for determining components of the Stokes vector Gf of the clutter surrounding each resolution cell of the radar, a circuit 12 for determining components of the unitary Stokes vector HQ of the polarization orthogonal to that of the clutter, a circuit 13 for computing the scalar product 1/2G.HQ and a CFAR detector 14. The circuit 10 for determining the components of the Stokes vector G for each resolution cell of the radar works on the basis of the complex video signals ZA and ZB available on the two crossed polarization reception channels of the radar and determines the components g0, g1, g2, g3 ! of the Stokes vector G by implementing the relationships of definition: ##EQU13## The circuit 11 for determining the components of the Stokes vector Gf of the clutter surrounding each resolution cell determines the components gf0, gf1, gf2, gf3 ! of the Stokes vector Gf of the clutter in establishing the mean components of the Stokes vector G of the resolution cells surrounding the resolution cell under analysis for the target detection. The circuit 12 for determining the unitary Stokes vector HQ of the polarization orthogonal to that of the clutter determines the components 1, α, β, γ! of the Stokes vector HQ on the basis of the relationships: ##EQU14## The circuit 13 for the computation of the scalar product delivers, for each resolution cell examined, a real signal representing a energy value of echo received in a polarization orthogonal to that of the clutter and therefore fulfils the role of a polarimetrical rejection filter. This signal which has the value: 1/2G.H.sub.Q =g.sub.0 +α.g.sub.1 +β.g.sub.2 +γ.g.sub.3 is subjected to the CFAR detector 14, of standard construction, generating a target detection binary signal PE. As indicated here above, a circuit of this kind with a polarimetrical rejection filter is optimal in the case of highly polarized clutter but inefficient in the presence of non-polarized clutter and blind to targets having the same polarization as the clutter. The polarimetrical processing circuit of FIG. 2 which carries out the function of a bank of polarimetrical filters associated with CFAR detectors whose outputs are coupled by an "OR" type logic circuit comprises the following elements: a circuit 20 for determining the components of the Stokes vector G for each resolution cell of the radar, followed by several circuits 21, 22, 23 for computing the scalar product with unitary Stokes vectors Hi corresponding to various directions of polarization evenly distributed on the Poincare sphere, CFAR detectors 24, 25, 26 connected individually to the outputs of the scalar product computation circuits 21, 22, 23 and an "OR" type logic circuit 27 combining the target detection outputs of the different CFAR detectors 24, 25, 26. The circuit 20 for determining the components g0, g1, g2, g3 ! of the Stokes vector G is similar to the circuit 10 of FIG. 1 and proceeds by means of the same relationships of definition (1). The scalar product computation circuits 21, 22, 23 are similar to the circuit 11 of FIG. 1 but, unlike this circuit 11, they operate with permanently fixed unitary Stokes vectors Hi that are chosen once and for all in such a way as to correspond to polarizations evenly distributed on the Poincare sphere. They generate signals representing the echo energy received in different polarizations sampling the different types of polarization possible and play the role of a bank of polarimetrical filters. The CFAR detectors 24, 25, 26, which are of standard construction, generate a binary target detection signal, depending on the crossing or non-crossing of their thresholds which are adjusted for a constant false alarm rate. The "OR" type logic circuit 27 combines the target detection outputs PEi of the different CFAR detectors 24, 25, 26 at a common output PE in which all the target detection operations are merged. As indicated here above, a circuit of this kind with a bank of polarimetrical filters is optimal for weak useful echoes and clutter with little or medium polarization. On the contrary, with highly polarized clutter, their efficiency falls. This is because the residue of clutter at output of the polarimetrical filters is very sensitive to the adjustment of the polarization of the filter on its "blind" polarization. The polarimetrical processing circuit of FIG. 3 fulfilling the function of a polarimetrical CFAR detector, comprises: a circuit 30 for determining the components of the Stokes vector G for each resolution cell of the radar followed by a circuit 31 for determining the components of the Stokes vector Gf and the degree of polarization pf of the clutter surrounding each resolution cell of the radar, a cell 32 for determining the components of the unitary Stokes vectors HP and HQ of the polarizations parallel and orthogonal to that of the clutter; two circuits 33, 34 for computing the scalar products 1/2G.HP and 1/2G.HQ, each followed by a weighting circuit 35, 36; a summator circuit 37 taking the sum of the signals from the weighting circuits 35, 36 coming from the scalar product computation circuits 33, 34, and a CFAR detector 38 connected to the output of the summator circuit 37. The circuit 30 for determining the components g0, g1, g2, g3 ! of the Stokes vector Gf is similar to the circuit 10 of FIG. 1 and works by means of the same relationships of definition (1). The circuit 31 for determining the components of the Stokes vector Gf and the degree of polarization pf of the clutter surrounding each resolution cell determines the components gf0, gf1, gf2, gf3 ! of the Stokes vector Gf of the clutter in computing the mean components of the Stokes vectors G of the resolution cells surrounding the resolution cell considered and the degree of polarization pf of the clutter by means of the relationship of definition: ##EQU15## The circuit 32 for determining the components of the unitary Stokes vectors HP and HQ of the polarizations parallel and orthogonal to that of the clutter determines the components 1, -α, -β, -γ! of the unitary Stokes vector HP of the polarization of the clutter and 1, α, β, γ! of the unitary Stokes vector HQ of the polarization orthogonal to that of the clutter implementing the relationship of definition: ##EQU16## For each resolution cell examined, the circuit 33 for computing the scalar product 1/2G.HP delivers a real signal representing an echo energy received in a polarization parallel to that of the clutter. This signal has the value: 1/2G.H.sub.P =g.sub.0 -α.g.sub.1 -β.g.sub.2 -γ.g.sub.3 For each resolution cell examined, the circuit 34 for computing the scalar product 1/2G.HQ delivers a real signal representing an echo energy received in a polarization orthogonal to that of the clutter and fulfils the role of a polarimetrical clutter-rejection filter. This signal has the value: 1/2G.H.sub.Q =g.sub.0 +α.g.sub.1 +β.g.sub.2 +γ.g.sub.3 The weighting circuits 35 and 36 reduce the energy values of clutter available at output of the scalar product computing circuits 33 and 35 to the same level by multiplying the output signal of the scalar product computing circuit 33 by the coefficient: ##EQU17## and the output signal of the scalar product computing circuit 34 by the coefficient: ##EQU18## so as to return to the presence of a non-polarized process as far as the clutter is concerned. The summator 37 adds the two signals delivered by the weighting circuits 35, 36 and applies the resultant signal to the input of the CFAR detector 38 which is of standard design. This CFAR detector 38 delivers a target detection binary signal PE at output as a function of the crossing or non-crossing of its threshold which is adjusted for a constant false alarm rate. A polarimetrical CFAR circuit of this kind is optimal for a powerful useful echo. The efficiency of the polarimetrical processing circuits described here above with reference to FIGS. 1 and 3 varies as a function of the signal-to-clutter ratio and the degree of polarization of the clutter. In order to obtain optimal efficiency in every case, it is proposed here either to select the appropriate polarimetrical processing or to associate different polarimetrical processing operations by logic merger or to combine the above two types of action while at the same time limiting the increase in complexity that arises therefrom. These associations and selections are determined according to one or more critical parameters as a function of the measured polarization of the clutter with a view to increasing the probability of detection of a useful echo. The associations more specially envisaged relate to processing operations having different natures with definite features of complementarity such as the polarimetrical rejection filter and the polarimetrical CFAR detector. Indeed, the merging of polarimetrical processing operations of similar nature is less worthwhile: the association of a bank of polarimetrical filters and of the polarimetrical rejection filter for example would ultimately result only in a particular bank of polarimetrical filters with, admittedly, an adaptive component. The graphs of curves of FIGS. 4 and 5 provide a glimpse of the complementary features of the different polarimetrical processing operations. They are plotted for Gaussian signals and for a useful signal that is non-polarized or that has a polarization unknown in principle as is the case for a radar with circularly polarized emission and for a probability of false alarm of 10-6. The curves represent, as a function of the degree pf of polarization of the clutter, the probability of detection Pd of the different polarimetrical processing operations. They are indexed by "a" for the polarimetrical rejection filter, "b" for a bank of twelve polarimetrical filters with evenly distributed polarizations on the Poincare sphere of polarizations, "c" for a bank of thirty-two polarimetrical filters with evenly distributed polarizations on the Poincare sphere and "d" for the polarimetrical CFAR detector. The graph of the curves of FIG. 4 is plotted for a low signal-to-noise ratio equal to 8.8 dB. It shows that, in this case, the banks of polarimetrical filters are at their most efficient over a wide range of degrees of polarization of the clutter but that the polarimetrical rejection filter ultimately proves to be more efficient beyond a degree of polarization of clutter pf of 0.8. The fact that the polarimetrical CFAR detector is systematically inferior to approaches based on polarimetrical filters can also be seen. The graph of the curves of FIG. 5 is plotted for a mean signal-to-clutter ratio equal to 12.8 dB corresponding to the conventional limits of the radar range. It shows that, in this case, the greatest efficiency is obtained with the polarimetrical CFAR detector for a degree of polarization of the clutter pf below 0.824 and that, beyond this value, the greatest efficiency is obtained with a polarimetrical rejection filter. It can also be seen, in the graphs of FIGS. 4 and 5, by comparing the curves a and b, that the efficiency of the bank of twelve polarimetrical filters is greater than that of the polarimetrical rejection filter below a degree of polarization of the clutter pf having a value in the range of 0.68. To derive advantage from these observations, there is proposed a polarimetrical processing operation in which the polarimetrical CFAR detector is used in parallel either with the bank of polarimetrical filters if the degree of polarization of the clutter is below a threshold set within a bracket ranging from 0.6 to 0.8 and preferably at 0.68 for a bank of polarimetrical filters having an average size of ten to fifteen filters or with the polarimetrical rejection filter if the degree of polarization of the clutter exceeds this threshold. FIG. 6 gives a schematic view of an exemplary implementation of a polarimetrical processing operation of this kind. The figure shows: a circuit 60 for determining the components of the Stokes vector G for each resolution cell of the radar, a circuit 61 for the polarimetrical learning of the clutter, a polarimetrical rejection filter 62 associated with a CFAR detector 63 and a polarimetrical CFAR detector 64 driven by a "polar" command of the polarimetrical clutter-learning circuit 61, a bank 65 of polarimetrical filters associated with CFAR detectors 66 and activated or disabled in opposition with the polarimetrical rejection filter 62 by a "disable" signal of the polarimetrical learning circuit 61 and an "OR" type logic circuit 67 bringing together the target detection output PE1 of the CFAR detector 63 placed downline with respect to the polarimetrical rejection filter 62, the target detection output PE2 of the polarimetrical CFAR detector 64 and the target detection output PE3 of the CFAR detectors 66 placed downline with respect to the polarimetrical filters of the bank 65 and a common target detection output PE. The circuit 60 for determining the components g0, g1, g2, g3 ! of the Stokes vector G for each resolution cell of the radar, which is placed at the head, is similar to the circuit 10 of FIG. 1 and works by means of the same relationships of definition (1). The polarimetrical learning circuit 61 comprises: a circuit for determining the components of the Stokes vector Gf of the clutter common with the polarimetrical rejection filter 62 and the polarimetrical CFAR detector 63 which is similar to the filter 11 of the polarimetrical rejection filter processing circuit of FIG. 1 (this circuit for determining the components of the Stokes vector Gf of the clutter delivers the components of the Stokes vector Gf of the clutter by way of a "polar" command), a circuit for determining the degree of polarization pf of the clutter placed after the circuit for determining the components of the Stokes vector Gf of the clutter, and a threshold circuit generating the disabling order "disable" depending on whether or not the degree of polarization of the clutter pf crosses a fixed triggering threshold in the vicinity of the value 0.68. The polarimetrical rejection filter 62 associated with the CFAR detector 63 has a constitution similar to that of the polarimetrical processing circuit with polarimetrical rejection filter of FIG. 1 except for the following points: firstly it shares its circuit for determining the components of the Stokes vector G of the resolution cells of the radar with the polarimetrical clutter-learning circuit 61, the polarimetrical CFAR detector 64 and the bank of polarimetrical filters 65; secondly, it shares its circuit for determining the components of the Stokes vector Gf of the clutter with the polarimetrical clutter-learning circuit 61 and the polarimetrical CFAR detector 64; thirdly it shares its circuit for determining the components of the unitary Stokes vector HQ of polarization orthogonal to that of the clutter with the polarimetrical CFAR detector 64; fourthly its circuit for computing the polar product is provided with a disabling command placing its output at the level zero when the disabling signal generated by the polarization clutter-learning circuit 61 corresponds to a degree of polarization of the clutter pf below the triggering threshold. The polarimetrical CFAR detector 64 has a constitution similar to that of the polarimetrical processing circuit of FIG. 3 fulfilling the polarimetrical CFAR function except for the fact that it shares some of its elements with a polarimetrical clutter learning circuit 61, the polarimetrical rejection filter 62 and the bank of polarimetrical filters 65. The bank of polarimetrical filters 65 associated with the CFAR detectors 66 has a constitution similar to that of the polarimetrical processing circuit of FIG. 2 fulfilling the function of a bank of polarimetrical filters except for the following points: firstly, it shares its circuit for the determining of the components of the Stokes vector G of the resolution cells of the radar with the polarimetrical clutter-learning 61, the polarimetrical rejection filter 62 and the polarimetrical CFAR detector 64; secondly its scalar product computing circuits are provided with an disabling command placing their output at the level zero when the disabling signal "disable" generated by the polarimetrical clutter-learning circuit 61 corresponds to a degree of polarization of the clutter pf greater than the triggering threshold The polarimetrical processing circuit of FIG. 6 can be used to derive the benefit of the advantages proper to the polarimetrical CFAR detector, the polarimetrical rejection filter and the bank of polarimetrical filters taken separately, namely the absence of "blind" polarization of the polarimetrical CFAR detector, the optimal character of the polarimetrical CFAR detector for the powerful useful echoes, the optimal character of the polarimetrical rejection filter in the case of highly polarized clutter, and the optimal character of the bank of polarimetrical filters for the weak useful echoes and the clutter with low or medium polarization. The fact of associating a polarimetrical CFAR detector, a polarimetrical rejection filter and a bank of polarimetrical filters in one and the same polarimetrical processing circuit entails only a small increase in the computational load of the signal processor of the radar. Indeed, the essential part of this load can be attributed to the estimation of the polarimetrical values of the clutter surrounding the resolution cell being tested, and this estimation is common to the polarimetrical CFAR detector and to a polarimetrical rejection filter. A polarimetrical processing circuit of this kind associating the polarimetrical CFAR detector, the rejection polarimetrical filter and the bank of polarimetrical filters can be used with radars having polarization agility. This is useful above all for the recognition function but also has advantages in terms of detection. The volume of the processing operation then increases in substantial proportions since the number of channels available goes from two to three and four respectively in the monostatic and bistatic cases corresponding to vector environments (clutter polarization) with a dimension of 6 or 10 instead of 3. Nevertheless, the different principles of polarimetrical processing envisaged and, with them, the configurations of association and selection described can be extended naturally to other uses. The criteria of choice however become inevitably more complex if only because of the effect of the polarization sent out on the degree of polarization of the clutter. This polarimetrical processing circuit associating the polarimetrical CFAR detector, the polarimetrical rejection filter and the polarimetrical filter bank may be placed in any surveillance radar working from any platform, whether or not on the ground, for example for air traffic control. The radar polarimetry substantially increases the visibility of the targets whether they are submerged in clutter or are clutter-free. The result thereof is that the wave shapes and the frequency processing operations become lighter. This has the beneficial consequence wherein it becomes possible to use the radar for other tasks during the time thus released. What is claimed is: 1. A target detection polarimetrical processing circuit for radar receivers comprising at least, in parallel, a polarimetrical CFAR detector provided with a target detection output and a polarimetrical clutter-rejection filter associated with a separate CFAR detector provided with a target detection output, and an "OR" type logic circuit combining the target detection outputs of the polarimetrical CFAR detector and of the separate CFAR detector placed after the polarimetrical rejection filter. 2. A circuit according to claim 1 comprising, in parallel, said polarimetrical CFAR detector provided with a target detection output, said polarimetrical clutter-rejection filter associated with a CFAR detector provided with a target detection output and a bank of polarimetrical filters associated with CFAR detectors provided with target detection outputs, and an "OR" type logic circuit combining the different target detection outputs. 3. A circuit according to claim 2, further comprising a selection circuit activating the polarimetrical clutter-rejection filter and disabling the bank of polarimetrical filters when the degree of polarization of the clutter exceeds a certain threshold and conversely disabling the polarimetrical clutter-rejection filter and activating the bank of polarimetrical filters when the degree of polarization of the clutter is below said threshold. 4. A circuit according to claim 3, wherein said threshold is chosen in a bracket of degrees of polarization of the clutter ranging from 0.6 to 0.8. 5. A circuit according to claim 4, wherein said threshold is chosen to be equal to a degree of polarization of the clutter equal to 0.68.

1996-07-05

en

1998-06-09

US-15602498-A

Blood type-specific safety labeling system for patients and blood products ABSTRACT A labeling system to ensure that blood products are compatible with a patient&#39;s blood type. A blood product housing, which is attached to a blood product, comprises a plurality of block-like projections and recesses corresponding to the antigens/antibody characteristics of a blood product. A patient housing, secured to the patient, comprises a plurality of mirror image three-dimensional block-like projections and recesses corresponding to the antigen/antibody characteristics of the patient&#39;s blood. If the blocks and recesses of the housings mate and seat to one another this confirms the blood product is compatible with the blood of the patient. If the blocks and recesses of the housings do not mate and seat to one another this confirms the blood product is not compatible with the blood of the patient. BACKGROUND OF THE INVENTION 1. Field of the Invention A key type identification system for blood products. 2. Description of the Relevant Art Human blood is "Typed," or classified into groups, to determine its compatibility with blood or blood products from another individual. If incompatible blood or blood products are administered (as with a blood transfusion), the automatic blood cell- and tissue-destroying process which ensues can be disastrous, and potentially fatal to the recipient. The current blood typing system is extremely sophisticated and complex, to the point that it can be difficult even for experienced health care professionals to comprehend or remember. Therefore, health care institutions engaged in the practice of transfusion medicine almost always utilize "Blood Banks," or departments devoted exclusively to the maintenance, processing, typing, distribution, and documentation of all aspects of transfusion therapy. While the compartmentalization of the blood bank is essential for safety and quality assurance, it often hides the technical aspects of transfusion therapy from health care personnel who are not directly involved with the Blood Bank. Although errors inevitably occur in blood processing, they are usually Identified and corrected before the blood is administered. Nonetheless, the health care profession must continue to seek better safeguards and methods of avoiding the potentially fatal administration of incompatible blood products to a patient. The current ABO typing system is complex and errors can occur anywhere in the processing of blood or blood products. There are two parts or components of human blood on which blood typing is based: the Red Blood Cells (RBC's), and the Plasma. Red blood cells primarily carry oxygen to the tissues, and Plasma is the liquid medium through which they travel throughout the body. On the surface of each RBC are "Antigens," or proteins, which can react with "Antibodies," found in the plasma. These Antigen-Antibody reactions usually result in the destruction of the RBC's, and this process is an extension of one of the body's natural methods of self defense. Blood "Typing" is a process which identifies the common or major Antigens and Antibodies found in blood. The three antigens are named "A," "B," and "RH"; the antibodies and are named for the antigens with which they combine: "Anti-A", "Anti-B", and "Anti-RH." Antigens are found on RBC's, and Antibodies are found in Plasma. TABLE A ______________________________________ MAJOR ANTIGENS ON RBC'S MAJOR ANTIBODIES IN PLASMA ______________________________________ A Anti-A B Anti-B Neither A nor B -- RH Anti-RH ______________________________________ When an antigen is combined with its corresponding Antibody, i.e., A with Anti-A, B with Anti-B, or RH with Anti-RH, a series of chemical reactions occur which ultimately destroy the RBC, and may trigger other tissue damaging processes. Humans have developed such that the genetically determined presence or absence of Antigens A, B, and RH determines the corresponding presence or absence of Anti-A, Anti-B, and Anti-RH. In normal individuals, if A is found on the surface of the RBC, the plasma does not contain Anti-A; if A is not present on the surface of the RBC, the plasma does contain Anti-A. The same applies for B and RH. If both A and B are found on the surface, then neither Anti-A nor Anti-B are present in the plasma. If neither A nor B are present on the surface of the RBC, then both Anti-A and Anti-B are found in the plasma. The following Table B summarizes. TABLE B ______________________________________ ANTIGEN RH ANTIGEN PRESENCE PRESENCE BLOOD ANTIBODIES PRESENT ON RBC ON RBC TYPE IN PLASMA ______________________________________ A Only Not Present A Negative Anti-B, Anti-RH A Only Present A Positive Anti-B B Only Not Present B Negative Anti-A, Anti-RH B Only Present B Positive Anti-A A and B Not Present AB Negative Anti-RH A and B Present AB Positive None Neither Not Present O Negative Anti-A, Anti-B, Anti-RH Neither Present O Positive Anti-A, Anti-B ______________________________________ There are, by definition, combinations of blood types which will unite the antigen with its corresponding antibody, triggering the destruction of the RBC. For example, whole blood of type A positive (with RBC surface antigens A and RH, and plasma antibody Anti-B) when mixed with whole blood of type B positive (with RBC surface antigens B and RH and plasma antibody Anti-A) will bring together the RBC- destroying combinations of surface antigen A with plasma antibody Anti-A and surface antigen B with plasma antibody Anti-B. Thus, these types are considered "incompatible." A patient can only receive whole blood of the exact same type. This is called "type specificity." Because this limits the quantity of blood that is available to any given patient for transfusion therapy, whole blood collected from blood donors is usually fractionated or separated into its components to yield plasma, platelets and packed RBC's. The ABO typing system is also used to classify these individually separated blood components (i.e., Fresh Frozen Plasma, Platelets, and Packed RBC's). The same compatibility rules apply, but the presence or absence of RBC's (and their surface antigens) or plasma (and its antibodies) in the blood component determines its compatibility with a patient's whole-blood. Packed RBC's typically do not contain Plasma; therefore, the absence of plasma antibodies increases the number of combinations of blood types with which the Packed RBC's are compatible. A patient having blood type A positive, for example, while able to receive only whole blood of type A positive, could also receive Packed RBC's of types A positive, A negative, O positive and O negative; and Plasma of types A positive and AB positive. Similarly, a patient of blood type B negative, while able to receive only whole blood of type B negative, could also receive Packed RBC's of types B negative and O negative; and Plasma of types B negative, B positive, AB negative and AB positive. The following table summarizes whole blood types and their compatibility with individual blood components. TABLE C ______________________________________ A A B B AB AB O O NEG POS NEG POS NEG POS NEG POS ______________________________________ Compatibility Between Whole Blood Type (Vertical) and Packed RBC Type (Horizontal) A NEG X X A POS X X X X B NEG X X B POS X X X X AB NEG X X X X AB POS X X X X X X X X O NEG X O POS X X Compatibility Between Whole Blood Type (Vertical) and Plasma Type (Horizontal) A NEG X X X X A POS X X B NEG X X X X B POS X X AB NEG X X AB POS X X O NEG X X X X X X X X O POS X X X X ______________________________________ X indicates "Compatible It is the shared responsibility of the blood bank and the individual health care practitioners to know and remember which blood mixture combinations are compatible, and to recognize and remember those combinations which are incompatible (and potentially lethal). With any process, errors occur unavoidably. There are many areas in transfusion medicine into which human error can be introduced. Although regulations require that quality control measures and error identification and analysis programs be ongoing in health care facilities, the complete elimination of errors in collection, typing, labeling, distribution, administration, and documentation, can never be achieved. All attempts, therefore, must be focused on the minimization of certain types of easily avoidable errors. While many safeguards are in place for the prevention of this potential catastrophe, there are still situations in which Inadvertent administrations occur. For example, a unit of blood may have been sent to a different patient with the same name; the blood administrator may have confused one patient's blood product for that of another patient. A wrong unit of blood may have been given under the stress of managing the patient's life-threatening emergency, or during the late-night shift, or at any time when the administrator's vigilance may be compromised. Most patient-type and blood-product-type identification systems focus on the administrator's verification of the accuracy of labeled information to assure type compatibility. Some inventions have attempted to invoke technology such as portable computers and bar-code readers to identify potential errors of type compatibility. Expensive computer technology is often unavailable, and humans process information with a fixed degree of fallibility, such that information is misprocessed by humans at a rate which is directly proportional to levels of stress. Most patient-type and blood-product-type identification systems are human-driven; therefore, this invention is designed to simplify the recognition of type-compatibility and type-incompatibility to reduce the potential for the inadvertent administration of incompatible blood-products. SUMMARY OF THE INVENTION The invention embodies three dimensional complimentary and uncomplementary shapes to predict the theoretical compatibility and incompatibility of typed blood product combinations. When a patient enters a health care setting in which blood transfusion therapy is possible, his/her blood type is determined. Next, a wrist identification band is applied with demographic information to which a labeled plastic tag is attached in the shape which corresponds to his/her whole-blood type according to the previously described model. Once the need is determined for the administration of blood products, the blood bank affixes to the blood product packaging a labeled plastic tag which is in the shape of the blood type of the specific blood product according to the previously described model. Once the blood product package is brought to the patient, and after existing protocols for proper identification of the patient and the corresponding blood product package, the two labeled plastic tags are compared. As previously described, complimentary shapes predict appropriately matched blood types, while uncomplimentary shapes warrant further verification. The system is designed to be a simple, cost effective means of identifying Blood Type incompatibilities, and in confirming Blood Types compatibilities in blood transfusion therapy. Successful implementation of this model should improve patient safety in the health care setting. Broadly the invention comprises a labeling system to ensure that blood products are compatible with a patient's blood type. A blood product housing comprises a plurality of three-dimensional physical indicia corresponding to the antigen/antibody characteristics of a blood product. A patient housing comprises a plurality of mirror image three-dimensional physical indicia corresponding to the antigen/antibody characteristics of a blood product. The blood product housing is engaged to the patient housing. If the indicia mate and seat to one another this confirms that the blood product is compatible with that of the patient. If the indicia do not mate and seat to one another this confirms that the blood product is not compatible with that of the patient. In a preferred embodiment, the indicia are block-like recesses and blocks which are arrayed to correspond to blood types. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portion of a labeling system embodying the invention for the antigen relationship of a red blood cell of type A positive; FIG. 2 is an illustration of a system for plasma of type A positive; FIG. 3 is an illustration of a system for whole blood of type AB negative; FIG. 4 is an illustration of a system of a compatible type A negative; FIG. 5 is an illustration of whole blood of type AB negative and corresponding packed RBC's of type AB negative (plasma and plasma antigens removed); FIG. 6 is an illustration of a match of patient (whole blood) of type AB negative which is compatible with packed RBC's of type AB negative; FIG. 7 is an illustration of a model which predicts compatibility such that a patient with type B positive blood should not normally receive packed RBC's of type A negative; FIG. 8 is an illustration of whole blood of type AB negative and a corresponding plasma of type AB negative RBC's and RBC antigens removed; FIG. 9 is an illustration of a model which predicts compatibility such that a patient with type AB negative blood can normally receive fresh frozen plasma of type AB negative; FIG. 10 illustrates the labeling system's ability to confirm the compatibility of individual blood components of differing types with a patient's blood of type AB negative; FIG. 11 is an illustration of a model which predicts compatibility such that a patient with type AB negative blood should not normally receive fresh frozen plasma of type O negative; FIG. 12 is an illustration of an extension of the principle of the model embodied in a "compatibility tab," which corresponds to the physical (as opposed to theoretical) compatibility of actual samples of blood when mixed together; and FIG. 13 is a procedural flow diagram implementing the invention of FIG. 12. DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The labeling system of the invention, while based on the state-of-the-art ABO Typing System, simplifies the complex aspects of the ABO Typing System and uses a labeling system physically shaped to distinguish combinations of blood-products which are compatible from those combinations which are incompatible. The labeling system, while complimenting a health care professional's knowledge, does not rely on that knowledge, which may, for any reason, be compromised. In the following discussion, the presence of an antigen on a RBC or of an antibody on the plasma is indicated schematically by the block in its appropriate recess. Its absence is indicated by an empty recess. Referring to FIG. 1, a RBC is represented schematically as a dark block-like housing 10 with three recesses 12a, 12b and 12c for three major block-like antigens A, B and RH, 14a, 14b and 14c respectively, of type A positive. The leftmost recess 12a placeholder is always reserved for antigen 14a, the middle recess 12b for antigen 14b, and the rightmost recess 12c for antigen 14c. Referring to FIG. 2, the plasma is similarly represented as a light block-like housing 20 with three recesses 22a, 22b and 22c for three major block-like antibodies 24a, 24b and 24c, Anti Rh, Anti B and Anti A respectively. An RBC of each of the major blood types can thus be represented. Referring to Table D below, for simplification, the housings representing the antigens are now dark. TABLE D __________________________________________________________________________ ##STR1## __________________________________________________________________________ Normal plasma and RBC's coexist with the appropriate combination of antigens and antibodies according to the aforementioned table. Using a similar model for the plasma object, and remembering that the placeholders for the antibodies mirror those for the antigens, then corresponding plasma for RBC's of a specific Type can be represented in Table E below. TABLE E __________________________________________________________________________ ##STR2## __________________________________________________________________________ FIG. 3 is an example of AB Negative whole-blood. Because normal human plasma coexists with RBC's, the labeling system can represent any whole-blood (a combination of plasma and RBC's) with the plasma object on the left (light) and its corresponding RBC object on the right (dark). A housing 30 is both dark 32 (RBCs) and light 34 (plasma) and both are characterized by recesses 36. Both antibodies 38 and antigens 40 are shown. With whole-blood as an example, the labeling system can represent all major blood Types using appropriate combinations of plasma objects and RBC's are shown in Table F below. TABLE F ______________________________________ ##STR3## ______________________________________ The labeling system of the invention differentiates between the compatibilities and incompatibilities of different blood type combinations. To test for compatibility using the previously described structures, (for example whole-blood), the structures are three dimensional objects (although shown in front views), similar to "locks and keys." Referring to FIG. 4, a blood product housing 50, secured to a blood product (not shown) for A Neg is placed over a patient housing 52, such as attached to a patient's wrist band (not shown). The dark RBC structures approach the light plasma objects. The recesses for the antigens and the antibodies are deliberately complimentary, such that they can fit together. Each blood type is normally compatible with itself, as demonstrated by this example. The labeling system can also be used for blood components. For example, the component "Packed RBC's" describes a whole-blood byproduct from which plasma has been effectively removed, leaving only RBC's. As such, normally, the antibodies contained in the plasma are no longer present. Referring to FIG. 5, whole-blood of Type AB Negative and a corresponding product of Packed RBC's of Type AB Negative are shown. As shown in FIG. 6, the labeling system ensures that a patient of Type AB Negative (assumed to have whole-blood) could receive Packed RBC's of his/her own type. As shown in FIG. 7, the labeling system also ensures that a patient with blood Type B Positive should not normally receive Packed RBC's of Type A Negative. The labeling system can also be used to represent another blood components, such as Fresh Frozen Plasma (FFP). This component describes a whole-blood byproduct from which the RBC's have been effectively removed. As such, normally, the antigens contained on the surface of the RBC's are no longer present. In FIG. 8, whole-blood of Type AB Negative, and a corresponding product of FFP of Type AB Negative are shown. As shown in FIG. 9, the labeling system ensures that a patient of Type AB Negative (patients are normally assumed to have whole-blood) could receive FFP of his/her own type. As shown in FIG. 10, the labeling system has the ability to confirm the compatibility of individual blood components of differing types with a patient's blood of type AB negative; As shown in FIG. 11, the labeling system also ensures that a patient with blood Type AB Negative should not normally receive FFP of Type O Negative. Referring to FIG. 12, a blood product housing 60 is characterized by a compatibility block 62 having a recess 64. A compatibility tab 66 covers the recess 64. A patient housing 68 has a mating compatibility tab 70. There is a space designated on the tab 66 for "Physical Compatibility." When a sample of donor blood is physically mixed with a sample of patient's blood in a test tube in the blood bank, its physical (as opposed to theoretical) compatibility is determined. The tab 66 is broken off only after compatibility testing is completed, if and only physical compatibility exists. To prevent the administration of compatibility-untested blood, the presence of that tag would prevent the proper fit of any combination of donor and recipient blood housings. FIG. 13 illustrates a procedure of the invention using the embodiment of FIG. 12. Blood product 72 is attached in any suitable manner to the product housing 60. The patient housing 68 is attached to a patient bracelet 74. Similarly, additional spaces or place holders for blocks/recesses could be added to the safety tags to represent other compatibility tests, such as the presence of minor (not major as A, B, and RH) antigens antibodies. The foregoing description has been limited to a specific embodiment of the invention. It will be apparent, however, that variations and modifications can be made to the invention, with the attainment of some or all of the advantages of the invention. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention. Having described my invention, what I now claim is: 1. A blood product identification system which comprises:a blood product housing having a face and at least one three-dimensional blood product indicium formed in the face, the shape of the blood product indicium being one piece of a set of two geometrically complementary pieces, the blood product indicium corresponding to the theoretical compatibility characteristics of a blood product; a patient housing having a face and at least one three-dimensional patient indicium formed in the face, the shape of the patient indicium being the second piece of the set, the patient indicium corresponding to the theoretical compatibility characteristics of a patient's blood whereby when the patient housing is engaged in a face-to-face relationship with the blood product housing, if the blood product indicium and the patient indicium mate and seat then the blood product housing and patient housing will seat indicating that the characteristics of the blood product is of a type which is compatible with the characteristics of the patient's blood and if the blood product indicium and the patient indicium do not mate and seat then the blood product housing and patient housing will not seat indicating that the characteristics of the blood product is of a type that is not compatible with the characteristics of the patient's blood; and means for preventing the mating and seating of the blood product indicium with the patient indicium when the characteristics of the blood product is of a type that is theoretically compatible with the characteristics of the patient's blood but physical compatibility has not yet been determined, the means for preventing being distinct from the blood product and patient indicia and comprises a cavity on one of the housings, a mating protuberance on the other housing and a removable tab positioned to prevent the cavity and the protuberance from mating. 2. The system of claim 1 wherein the theoretical compatibility characteristics of the blood product and the patient's blood comprise antigen/antibody characteristics. 3. The system of claim 2 wherein the blood product indicium and patient indicium comprise recesses and projections. 4. The system of claim 3 wherein the recesses and projections are block-shaped. 5. The system of claim 3 wherein the blood product indicium and patient indicium correspond to the major antigens A, B, RH and the major antibodies anti-A, anti-B and anti-RH. 6. The system of claims 1, 2, 3 or 4 wherein the blood product indicium correspond to blood products selected from the group consisting of plasma/RBCs, RBCs, fresh frozen plasma, cyroprecipitate, platelets and packed RBCs. 7. The system of claims 1, 2, 3 or 4 wherein the patient indicium correspond to major antigen/antibodies selected from the group consisting of antigen-A, B, or RH, and anti-A, anti-B and anti-RH. 8. The system of claim 1 wherein the removable tab seals the cavity.

1998-09-17

en

2000-05-09

US-42902073-A

Method and apparatus for determining the distance between the surface of an eye and a reference point ABSTRACT The distance between the cornea of a human eye and some reference point is determined by projecting, from locations on either side of the reference point, a pair of light images toward the eye so that the pathways traversed by the projected light images intersect at some predetermined distance from the reference point. The desired distance between the eye and the reference point is determined when the person is positioned so that the projected images are superimposed on the cornea of the person&#39;&#39;s eye. In accordance with one embodiment of the invention, when the desired distance is determined, moveable headrest apparatus which is in contact with the person&#39;&#39;s forehead is locked in place to assist in preventing further movement of the person&#39;&#39;s head. United States Patent Tate, Jr. 5] Sept. 9, 1975 [54] METHOD AND APPARATUS FOR 3,610,128 /1971 Bellows 356/12 X DETERMINING THE DlSTANCE BETWEEN 3.622.242 ll/l97l Land ct al 356/12 3,807,858 4/1974 Finch 356/1 THE SURFACE OF AN EYE AND A 1817,63] 6/1974 Kawahara 356/! REFERENCE POINT [75] Inventor: George W. Tate, Jr., Dallas. Tex. [73] Assignees: Giles C. Clegg, Jr.; John R. Lynn. both of Dallas, Tex. part interest to each [22] Filed: Dec. 28, 1973 [21 1 App]. No: 429,020 [52] US. Cl. 351/1; 351/38; 356/1; 356/17 [51] Int. Cl. A61B 3/10; 001C 3/00 [58] Field of Search 356/1, 12, 17; l/38 351/1 [56] References Cited UNITED STATES PATENTS l 65l 66l 12/1927 Armbrustcr 351/38 2,081.96) 6/1937 Allen ct 351/38 X 3 002 093 9/1961 Kis ct al 356/17 X 3,187J 6/1965 Milncs.. r. 356/1 X 3,408,137 10/1968 Reincr 3. 1/28 148 .J'JJHM f c/ISS Primary Examiner-Paul A. Sacher Attorney, Agent, or Firm-Giles C. Clegg, Jr. [57] ABSTRACT The distance between the cornea of a human eye and some reference point is determined by projecting, from locations on either side of the reference point, a pair of light images toward the eye so that the pathways traversed by the projected light images intersect at some predetermined distance from the reference point. The desired distance between the eye and the reference point is determined when the person is positioned so that the projected images are superimposed on the cornea of the person's eye. In accordance with one embodiment of the invention, when the desired distance is determined. moveable headrest apparatus which is in contact with the persons forehead is locked in place to assist in preventing further movement of the persons head. 12 Claims, 10 Drawing Figures PATENTEU SEP 9 975 SEIEET 2 BF 2 EYE EQUIPMENT TESTING METHOD AND APPARATUS FOR DETERMINING THE DISTANCE BETWEEN THE SURFACE OF AN EYE AND A REFERENCE POINT BACKGROUND OF THE INVENTION This invention relates to distance measuring apparatus and method and more particularly to apparatus and method for determining the distance between the cornea of the eye of a person and a fixed reference point. Eye examinations to determine the so-called refractive error of a person's eyes are carried out by having the person view through various trial lenses on a screen. Different pairs of trial lenses are placed in front of the person and the person is asked to indicate his preference of lens for each pair, i.e., which lens of each pair provides the clearest view of the test symbol. In this manner, the refractive error of the person's eyes can be determined by determining what power of trial lens is required to correct the refractive error. As is well known, the accuracy ofdetermining the refractive error depends on maintaining a constant distance between the cornea of the subjects eye and the surface of the trial lens nearest the subject. If this distance, known as the vertex distance, is not maintained constant throughout the examination, spurious and inconsistent results may be obtained during the course of the examination. This is so because the vertex distance determines. in part, the effective power of lens needed to correct the refractive error of that distance. To maintain a constant vertex distance during an eye examination, a chin rest and headrest may be provided so that the subject will remain in a fixed position relative to the trial lens. After fixing the vertex distance. it is still necessary to measure this distance so that eye glasses can be prepared which simulate the power of the refractive system (i.e., the trial lens and vertex distance) used to measure the subjects refractive error. That is, the refractive system which produced an indication ofgood vision during the examination procedure was based on a certain fixed vertex distance and if these results are to be reproduced in a pair of eye glasses for the subject, then that vertex distance must be taken into account. This does not mean the same vertex distance must be maintained in the eye glasses as was maintained during the examination, but the vertex distance maintained during the examination must be known so that the corrective power of the eye glasses compensates for any difference between the two vertex distances. In prior art methods of measuring the vertex distance during eye examination, measuring apparatus is placed against either the eye ball itself or the eye lid of the sub ject to measure the distance between the eye surface or eye lid and the trial lens, If the apparatus is placed against the eye ball, an accurate measurement is obtained. but the subject generally exhibits discomfort with this type of measurement unless anasthetic drops are used. If the measuring apparatus is placed against the eye lid. then an error may be introduced in the measurement on account of the measurement being made from the eye lid rather than from the surface or cornea of the eye. SUMMARY OF THE INVENTION It is an object of the present invention, in view of the above mentioned prior art. to provide method and ap paratus for measuring the vertex distance during eye examination without the need for touching the surface of the eye or the eye lid. In accordance with one aspect of the invention, it is an object to provide a simple yet effective method and apparatus for fixing and maintaining the vertex distance during an eye examination. In accordance with another aspect of the invention, it is an object to provide a method and apparatus for monitoring the vertex distance and for indicating the magnitude of any change therein during an eye examination. In one specific illustrative embodiment of the inven' tion, first and second light images are projected generally from first and second sources respectively, spaced on either side of a reference point on the refraction equipment. toward a subject whose eyes are being examined. The two souces are arranged so that the path ways traversed by the projected images intersect at some predetermined distance from the reference point, this distance corresponding to the desired vertex distance for the eye examined, the first and second images are superimposed on the cornea of the eye. When the subject is so positioned, the desired vertex distance is established. BRIEF DESCRIPTION OF THE DRAWINGS A complete understanding of the present invention and of the above and other objects and advantages thereof may be gained from a consideration of the following description presented in connection with the accompanying drawings in which: FIG. I is a perspective view of apparatus for determining the vertex distance made in accordance with the priciples of the present invention; FIG. 2 is a side view of the apparatus of FIG. 1; FIG. 3 is a top view of the headrest apparatus of FIG. 1: FIG. 4 is a top view of the image projecting apparatus and periscope structure of FIG. 1; FIGS. 5A, 5B and 5C show exemplary images projected by the image projecting apparatus of FIG. 1; FIG. 6 shows a cross-sectional view of one of the image projecting devices of FIG. I; FIG. 7 schematically illustrates means for generating signals indicating vertex distance; and FIG. 8 schematically illustrates an alternative apparatus for determining or measuring the vertex distance. DETAILED DESCRIPTION FIGS. I through 4 show one illustrative embodiment of apparatus for determining and maintaining a fixed vertex distance for eye examinations. The apparatus is used in conjunction with and attached to a casing 102 for holding trial lens 104 (FIG. 4) for performing refractive error measurement. Typically, other trial lenses would be used in conjunction with the lens I04 to present before a subject lens combinations having different refractive powers. (The other lens which might be used in conjunction with the trail lens 104 are not shown in the drawings.) A pair of image projecting devices I06 and 110 are positioned on either side of the casing I02 as best seen in FIGv 4. Any suitable means for attaching the devices I06 and 110 to the casing I02 might be employed. The devices 106 and 110 are positioned to project light images to the right of the apparatus in the direction in which a subject would be positioned. The devices I06 and 110 are oriented so that the pathways represented by dotted lines I07 and Ill traversed by the projected light images intersect at a predetermined distance from the trial lens 104. This distance is selected as the distance from the trial lens I04 at which a subjects eye is to be positioned for examination. An exemplary image projecting device is shown in FIG. 6 and includes a cylindrical casing 600 (shown in cross-section), one end of which is enclosed and the other end of which is open. Positioned in the casing 600 at the closed end thereof is a light emitting source 602 which may simply be a common light bulb. A focusing lens 610 is positioned near the open end of the casing 600 for the purpose of causing the light passing therethrough from the light source 602 to converge as generally shown in FIG. 6. A transparent slide 606, such as glass or film. is positioned between the light source 602 and the lens 610. The image to be projected by the device of FIG. would be included on the slide 606. (Types of images which could be utilized will be discussed latcr.) The focusing lens 610 is selected so that the image projected by the device will be in sharp focus at substantially the distance at which the light paths from the two image projecting devices intersect. The reason for this will become clear as the apparatus is fur ther described. The described technique and apparatus for projecting the images are. of course, well known in the slide projector art. for example. Also affixed to the casing I02 on the bottom surface thereof is a periscope I14 through which the person conducting the eye examination can view the cornea of the eye of the subject. The periscope I14 includes an eye piece 118 through which the examiner would look and an appropriate arrangement of mirrors internal to the periscope for directing light from the direction of the person's eye through the periscope II4 and eye piece H8. The pcriscope [I4 is provided to allow the examiner a front view of the eye of the subject which. because of the placement of the apparatus in front of the eye of the subject, might not otherwise be possible or convenient. Of course, if a clear view of the cornea of the eye is presented, the periscope I I4 may be omitted. The trial lens casing 102 is attached by braces 122 to a headrest housing 126 which, in turn. is rotatably at tached to a support boom or bar 138. The bar 138 forms part of an articulated arm having adjustable joints and swivels (not shown) to permit universal movement of the headrest housing I26. The articulated arm is carried by an appropriate floor or wall support. The housing I26 is box-shaped and carries a slidable bar 130. with a scale 190 inscribed thereon, extending through an opening at either end of the housing (only one opening is shown in FIG. I A pad I34 covers one end of the bar 130 to allow the subject 100 to comfort ably place his forehead against the end of the bar. One end of an extension spring I42 is attached to the out side of the housing I26 and the other end of the spring is attached near the non-padded end of the bar 130 to urge and maintain the bar against the head of the subject I00 when the subject is within a certain distance of the housing I26. Otherwise, the bar I is free to slide longitudinally in the housing 126. A tightening screw I46 is located on top of the housing I26 and is adapted to be manually screwed into or out of the housing so as to cause the end 148 of the screw to be placed into or out of contact with the top surface of the bar I30. By screwing the screw 146 into the housing. the end 148 of the screw contacts the bar I30 and. by friction, prevents it from sliding in the housing I26. To free the bar so that it may slide. the screw 146 is simple screwed outwardly from the housing 126. The use of the vertex distance measuring apparatus will now be described. A subject whose eyes were to be examined would be initially positioned so that the subjects chin rested upon a chin rest 162. The vertex measuring apparatus would then be swung into position in front of the subject's face with the padded end of the bar 130 resting against the forehead of the subject and the image projection devices 106 and 110 positioned substantially at the subject's eye level. The image projecting devices 106 and I I0 would then be activated to project images in the direction of the subject. Assuming that the subject were not yet properly positioned at the desired vertex distance, the projected images would probably fall on some part of the face of the subject, spaced horizontally from each other. The vertex measuring apparatus would then be moved either toward or away from the subject as was necessary to cause the images falling on the subjects face to move closer together toward the eye to be tested. When the apparatus was positioned so that the projected images were superimposed upon the cornea of the subjects eye, the desired vertex distance would be determined. superimposition would occur. of course. when the cornea of the eye were located at the point of intersection of the image pathways. During the apparatus positioning procedure, as long as the subject was within a certain distance of the apparatus. the padded end of the bar 34 would be maintained in contact with the subjectss forehead by the spring 142. That is. the housing I26 would simply slide about the bar as the housing was moved toward or away from the subject. As indicated earlier, the examiner views the images projected on the cornea of the eye through the periscope 114 to determine when the images are properly superimposed. At this point, the cornea is at a known vertex distance from the trial lens 104. If the examiner desires to change this distance for some reason. he can simply note the position of the bar 130 with respect to the housing 126 by means of the scale I90 and instruct the subject to move forward or backward. as desired. a distance measured by the scale. When the trail lens 104 and casing 102 are positioned at the desired vertex distance, the examiner tightens the screw I46 against the bar I30 to lock the bar in place relative to the housing I26. The bar is now positioned for the desired vertex distance. to provide a headrest for the subject. By instructing the subject to maintain his forehead against the bar I30, a constant known vertex distance can be maintained for the examination. Rather than locking the bar 130 in place during the eye examination. it may be desirable to simply use the bar as a feeler gauge to disable automated eye testing equipment, whenever the subject moved from the de sired vertex distance, or to provide for monitoring the vertex distance and to supply to the eye testing equipment a signal indicating the magnitude and direction of change of the distance. In such a case, movement de tection apparatus could be included in the housing 126 to detect movement of the bar 130 and for signaling the automatic eye testing equipment accordingly. Exemplary movement detection apparatus is shown in FIG. 7. Such apparatus includes a rack and pinion gear combination 701 and 702, with the rack 701 corresponding to the bar 130 of FIGS. 1 through 3. As the rack 701 is moved forward or backward as result of movement by the subject, it causes the pinion 702 to rotate. The pinion 702 is mechanically coupled to a shaft angle encoder 704, which generates an output defining the horizontal position of the rack 701. This output would be utilized by the eye testing equipment, for example, to take into account any movement of the subject, i.e., any changes in the vertex distance. Since the initial position of the rack 701 could be different for different subjects (e.g. because of different facial structure of the subjects) it is necessary to provide the eye testing equipment with an indication of the intial or starting position of the rack (at the beginning of the eye examination) any deviation from which the eye testing equipment will measure. A simple pushbutton signal generating device 706 is provided to enable the examiner to signal the eye testing equipment (by depressing a push button 707) when the subject is placed at the desired vertex distance. In response to this signal, the eye testing equipment records the initial position of the rack 70], and any changes from this position will be measured by the eye testing equipment. The outputs of the Encoder 704 and Signal Generator 707 can be connected to the eye testing equipment by cable 705. Alternative apparatus for determining or monitoring the vertex distance is shown in FIG. 8. This apparatus includes light image projectors 106 and 110 each mounted on the housing 102 to rotate about a vertical axis. Discs 802 and 804 are mounted on the top of the light projectors 106 and 110 respectively, and disc 804 is mechanically coupled to a shaft angle encoder 810. The discs 802 and 804 are mechanically coupled together by a linkage 806 so that rotation of one of the light projectors will cause rotation of the other projector by an equal amount but in an opposite direction. The shaft angle and encoder 810 is electrically coupled to the aforementioned automated eye testing equipment to provide a signal of the angular position of the disc 804 and thus of the light image projector 110. A push-button signaling device 814, similar to that discussed in connection with FIG. 7, is also provided. Also included is a fixed headrest 180. In operation, after the subject is positioned against the headrest 180, the light image projectors 106 and 110 are rotated until the projected images are superimposed on the cornea of the subjects eye. The push button on the push-button device 814 is then depressed causing a signal to be applied to the eye testing equipment. The eye testing equipment then records the signal generated by the shaft angle encoder 810 representing the angular position of the light projectors 106 and 110. The vertex distance V is given by the formula V D/2 Cot-an 9 where D represents the distance between the projectors and 9 represents the angle between the long axis of the projectors and a line extending midway between the projectors from a point at which the projected light images intersect. Of course, from this formula, the automated eye testing equipment can determine the vertex distance. FIG. 5 graphically shown exemplary images which might be used in connection with the image projecting devices 106 and 110. For example, the image shown in FIG. 5A might be projected by the image projecting device 110 and the image shown in FIG. 5B projected by the device 106. The proper vertex distance would be indicated when the two images were superimposed as shown in FIG. SC on the cornea of the subjects eye. Numerous image shapes or configurations could be employed facilitating ease of determining proper superimposition of the images. Although the invention has been described with respect to a particular preferred embodiment thereof, many changes and modifications will become apparent to those skilled in the art in view of the foregoing description which is intended to be illustrative and not limiting of the invention. The appended claims are intended to cover such changes and modifications. What is claimed is: 1. Apparatus for defining a distance between the surface of the eye of a person and a reference point comprising a frame on which said reference point is defined, first projecting means carried by said frame and positioned on one side of the reference point for projecting an image in a first direction generally toward the person s eye, second projecting means carried by said frame and positioned on the other side of the reference point for projecting an image in a second direction generally toward the eye, said projecting means being positioned so that the projected images will be superimposed on each other on the surface of the eye when the eye is located at a predetermined distance from the reference point, a housing secured to said frame, movable headrest means extending from said housing for contacting the head of the person and movable with respect to the reference point. biasing means for urging the headrest towards the person and maintaining contact between headrest and the head of the person when the head is within a certain distance of the reference point and an indicating means for providing an indication of the position of said moveable headrest means relative to the reference point. 2. Apparatus as in claim 1 further comprising manual means for locking said movable means in a position fixed relative to the reference point. 3. Apparatus as in claim 1 wherein said indicating means comprises means for generating and electrical signal indication of the position of said movable headrest means relative to the reference point. 4. Apparatus as in claim 1 further comprising periscope means secured to said frame and positioned to enable a person to view therethrough the surface of said eye when the eye is located substantially at said predetermined distance from the reference point. 5. Apparatus as in claim I wherein said indicating means comprises indicia on said movable means for indicating the position of said headrest relative to said reference point. 6. Apparatus as in claim I including mounting means for rotatably mounting said first projection means and said second projection means on said frame for rotation about generally vertically disposed, parallel axis, means responsive to rotation of one of said projecting means for causing the other projecting means to rotate by a mount equal to but opposite in direction of the rotation of said one projecting means to cause the first and second light images to be superimposed on the cornea of the persons eye at different pre-determined distances, means for indicating the rotational position of the first projecting means. 7. Apparatus as in claim 6 wherein said indicating means comprises a shaft angle Encoder for generating a signal indicating the rotation of said first projecting means. 8. Apparatus as in claim I wherein each of said projecting means comprises a light emitting means a focusing lens for focusing the projected image at substantially said desired distance, and a transparent slide positioned between said light emitting means and said focusing means for carrying the image light from said light emitting means through said slide and said focusing means to project the light image. 9. Apparatus as in claim 8 wherein the image of the transparent slide associated with the first projecting means is different from but complimentary to the image of the transparent slide of the second projecting means. 10. Apparatus for fixing the distance between the cornea of the eye ofa person and a reference point on refraction equipment comprising means secured to said refraction equipment on one side of the reference point for projecting a first light image along a first pathway generally toward the person, means secured to said equipment on the other side of said reference point for projecting a second light image along a second pathway generally toward the person. said first and second pathways intersecting a predetermined distance from the reference point. the desired distance between the cornea of the eye and the reference point being established when the first light image is superimposed over the second light image on the cornea of the eye, a headrest feeler means for contacting the persons forehead when the eye of the person is positioned at said desired distance from said reference point, and means responsive to movement of said feeler means for generating an electrical signal to thereby indicate that the persons forehead has moved. ll. Apparatus as in claim 10 wherein said projecting means each comprise a light emitting means. a focusing lens for focusing the projected image at substantially said desired distance, and a transparent slide positioned between said light emitting means and said focusing lens for carrying the image light from said light emitting means passing through said slide and said focusing lens to project the light image. 12. Apparatus as in claim 10 wherein said signal generating means includes means for generating a signal indicating the magnitude of the movement of said feeler means. 1. Apparatus for defining a distance between the surface of the eye of a person and a reference point comprising a frame on which said reference point is defined, first projecting means carried by said frame and positioned on one side of the reference point for projecting an image in a first direction generally toward the person''s eye, second projecting means carried by said frame and positioned on the other side of the reference point for projecting an image in a second direction generally toward the eye, said projectiNg means being positioned so that the projected images will be superimposed on each other on the surface of the eye when the eye is located at a predetermined distance from the reference point, a housing secured to said frame, movable headrest means extending from said housing for contacting the head of the person and movable with respect to the reference point, biasing means for urging the headrest towards the person and maintaining contact between headrest and the head of the person when the head is within a certain distance of the reference point and an indicating means for providing an indication of the position of said moveable headrest means relative to the reference point. 2. Apparatus as in claim 1 further comprising manual means for locking said movable means in a position fixed relative to the reference point. 3. Apparatus as in claim 1 wherein said indicating means comprises means for generating and electrical signal indication of the position of said movable headrest means relative to the reference point. 4. Apparatus as in claim 1 further comprising periscope means secured to said frame and positioned to enable a person to view therethrough the surface of said eye when the eye is located substantially at said predetermined distance from the reference point. 5. Apparatus as in claim 1 wherein said indicating means comprises indicia on said movable means for indicating the position of said headrest relative to said reference point. 6. Apparatus as in claim 1 including mounting means for rotatably mounting said first projection means and said second projection means on said frame for rotation about generally vertically disposed, parallel axis, means responsive to rotation of one of said projecting means for causing the other projecting means to rotate by a mount equal to but opposite in direction of the rotation of said one projecting means to cause the first and second light images to be superimposed on the cornea of the person''s eye at different pre-determined distances, means for indicating the rotational position of the first projecting means. 7. Apparatus as in claim 6 wherein said indicating means comprises a shaft angle Encoder for generating a signal indicating the rotation of said first projecting means. 8. Apparatus as in claim 1 wherein each of said projecting means comprises a light emitting means, a focusing lens for focusing the projected image at substantially said desired distance, and a transparent slide positioned between said light emitting means and said focusing means for carrying the image light from said light emitting means through said slide and said focusing means to project the light image. 9. Apparatus as in claim 8 wherein the image of the transparent slide associated with the first projecting means is different from but complimentary to the image of the transparent slide of the second projecting means. 10. Apparatus for fixing the distance between the cornea of the eye of a person and a reference point on refraction equipment comprising means secured to said refraction equipment on one side of the reference point for projecting a first light image along a first pathway generally toward the person, means secured to said equipment on the other side of said reference point for projecting a second light image along a second pathway generally toward the person, said first and second pathways intersecting a predetermined distance from the reference point, the desired distance between the cornea of the eye and the reference point being established when the first light image is superimposed over the second light image on the cornea of the eye, a headrest feeler means for contacting the persons forehead when the eye of the person is positioned at said desired distance from said reference point, and means responsive to movement of said feeler means for generating an electrical signal to thereby indicate that the persons forehead has moved. 11. Apparatus as in claim 10 wherein said projecting means each comprise a light emitting means, a focusing lens for focusing the projected image at substantially said desired distance, and a transparent slide positioned between said light emitting means and said focusing lens for carrying the image light from said light emitting means passing through said slide and said focusing lens to project the light image. 12. Apparatus as in claim 10 wherein said signal generating means includes means for generating a signal indicating the magnitude of the movement of said feeler means.

1973-12-28

en

1975-09-09

US-26504488-A

Sewing machine pneumatic decurler ABSTRACT An apparatus for eliminating curls at the cut ends of fabric workpieces provides air tubes directed toward the curls so that air flow flattens the curls. The apparatus includes a device for generating air flow; a first tube connected to the device for generating air flow and having one end fixed to the presser foot of a sewing machine; a second tube connected to the device for generating air flow and having one end situated under the throat plate of a sewing machine; and a valve positioned between the device for generating air flow and the tubes. The first tube includes an opening facing the curls and a contact portion extending horizontally and overlapping the curled edge of the workpiece for contacting the curled edge when the presser foot is moved downwardly. The second tube includes an opening facing the curls. The pattern of air flow is switchable to one or both of the tubes depending on the configuration of the curls; that is, whether the fabric is outwardly curled or inwardly curled. FIELD OF THE INVENTION This invention relates to an apparatus for eliminating curls formed at the cut-end of knitted fabric workpieces so that when the workpieces are sewed together along the cut-ends, such curls are flattend before being sewed. More particularly, the invention pertains to an apparatus for flatening curls before sewing. BACKGROUND OF THE INVENTION It is generally known that when a knitted fabric is cut, its cut-end tends to be curled. When such fabric workpieces are cut together and overlapped for sewing together, it is necessary to stretch the workpieces to flaten the curl before sewing the workpieces together. FIG. 8 to FIG. 14 illustrate one conventional type of apparatus for eliminating curls described in Japanese patent publication No. 59-45395 titled "apparatus for eliminating curls", published on Nov. 6, 1984, and filed on June 9, 1981. This apparatus includes a presser bar 101 and presser foot 102 attached to the presser bar 101. The apparatus also includes a base plate 103 fixed to a bed 104. A first curl-eliminating body 105 is located at the front side of the presser foot 102. A slope 107, formed at the end of the first curl-eliminating body 105, is down-sloped rightwardly when viewed from an operator. The tip end 108a of projection 108 is down-sloped rightwardly so that it creeps into the curled portion K of the workpiece (See FIG. 12). Arrow Y in FIG. 8 indicates the direction in which the workpiece is fed. Another slope 109 is down-sloped towards the operator. A middle plate 110 is located under the first curl-eliminating body 105 and adapted to rotate around a shaft 106. At the end of the middle plate 110, a projection 111 is provided. This projection 111 is larger than the projection 108 as shown in FIG. 9, and provides a slope 112 and another slope 113. The first curl-eliminating body 105 and the middle plate 110 contact one another only at projection 108 and projection 111. Springs 118 and 119 urge the first curl-eliminating body 105 and the middle plate 110 to rotate counter clockwise when viewed from the operator side such that the middle plate 110 is clamped between the first curl-eliminating body 105 and the base plate 103. The base plate 103 provides a second curl-eliminating body 114 at its end. An L-shaped arm 120 is rotatably supported by a support column 120A as shown in FIG. 9, FIG. 10, and FIG. 11, and its end 120a contacts the surface of the first curl-eliminating body 105 as shown in FIG. 10. Another end 120b of the L-shaped arm 120 engages horizontal bar 101a which extends from the presser bar 101. A restricting plate 121 is located between the presser foot 102 and the second curl-eliminating body 114. The restricting plate 121 contacts the edge of the workpiece W and guides the workpiece W as shown in FIG. 12. Referring to FIG. 10, the operation of this conventional curl eliminator will be explained hereafter. When the presser bar 101 is lifted by knee-operation, the presser foot 102 and the horizontal bar 101a will also be lifted, and as a result, L-shaped arm 120 rotates clockwise such that end 120a presses the first curl-eliminating body 105 downwardly, so that the first curl-eliminating body 105 rotates in a clockwise direction. The presser foot 102 than descends for sewing, and the horizontal bar 101a also descends. As a result, the L-shaped arm 120 rotates counter clockwise, and is released from pressing the first curl-eliminating body 105. Thereby, springs 118 and 119 urge the first curl-eliminating body 105 and the middle plate 110 to rotate counter clockwise such that two cloths W1, and W2, which constitute the workpiece W, are clamped between the middle plate 110 and the first and second curl eliminating bodies, respectively. At this point, the sewing machine starts and the workpiece W is fed in the direction of arrow Y. Since the operational action for both upper cloth W1 of workpiece W and lower cloth W2 of workpiece W are virtually the same, reference will be made to only the upper cloth W1. As the workpiece W is fed, the curl K1 approaches projection 108 of the first curl-eliminating body 105, and the curl K1 is smoothly introduced into the projection 108 since a slope 108T is formed in the same direction as the curling K1 as shown in FIG. 13. Since the projection 108 is situated in front of slope 107, the curl K1 will be pushed rightward and stretched as the workpiece W is fed so that the curled portion diminishes. Referring to FIG. 13, the upper cloth W1 of the workpiece W is clamped between the tip end of the projection 108 and the middle plate 110. Since the contact between projection 108 and the middle plate 110 is one-point contact, when the workpiece W is pulled by the dog feed (not shown), the curl K1 tends to be diminished. As the cloth W1 is further fed and passes over the slope 107, the curl K1 becomes smaller as shown in FIG. 14. Finally, the curl K1 creeps in between the first curl-eliminating body 105 and the middle plate 110, and is flattened. The flattened curl K1 is further fed to the presser foot 102 and is sewed by a needle N (FIG. 12). The conventional type of eliminator just described is available, where the curls K1 and K2 are curled outwardly as shown in FIG. 6 as curls 15 and -6. Where, however, the curls K1, and K2 are curled inwardly as shown in FIG. 7 as curls 17 and 18, the conventional type of eliminator is not available. If some other curl stretching devices are provided at the middle plate 110, the structure of the conventional eliminator becomes more complicated and invites higher costs. OBJECTS OF THE INVENTION It is, therefore, an object of the present invention to provide a curl eliminating device which can be used when the curls at the edges of the workpiece curl inwardly as well as outwardly. It is a further object of the present invention to provide a simple, low cost curl eliminating device. These and other objects will be apparent to those skilled in the art from the description which follows. SUMMARY OF THE INVENTION It has now been found that these objectives may be achieved by the use of air pressure. According to the present invention, a first, upper air tube is provided having one end connected to an air source or means for generating air flow. An opening at the other end of the upper air tube is situated at the front side of the presser foot of a sewing device and is adapted to touch the upper of two cloth workpieces being sewn together and separate therefrom in association with the up-down movement of the presser foot. A second, lower air tube is also provided having one end connected to an air source. An opening at the other end of the lower air tube is situated at the under side of the throat plate of a sewing device. Both openings from the first and the second air tubes are provided with nozzles such that air flowing from the nozzles is directed to flatten curls formed at the edges of the upper cloth workpiece and the lower cloth workpiece, respectively. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention will be described in detail with reference to the following drawings: FIG. 1 is a perspective view of a curl eliminating apparatus applied to a overedge sewing machine according to the present invention; FIG. 2 is a partial plan view drawing of FIG. 1; FIG. 3 is a partial front view drawing of FIG. 1; FIG. 4 is an explanatory drawing explaining how curls outwardly curled are eliminated; FIG. 5 is an explanatory drawing explaining how curls internally curled are eliminated; FIG. 6 is a perspective view drawing of FIG. 4; FIG. 7 is a perspective view drawing of FIG. 5; FIG. 8 is a perspective view drawing of a conventional curl eliminating apparatus; FIG. 9 is a plan view drawing of FIG. 8; FIG. 10 is a front view drawing of FIG. 8; FIG. 11 is a partial left side view drawing of FIG. 9; FIG. 12 is a partial plan view of essential portion of conventional curl eliminator when a workpiece is placed and fed; FIG. 13 is a sectional drawing viewed in direction of arrow 13--13 in FIG. 9; and FIG. 14 is a sectional drawing viewed in direction of arrow 14--14 in FIG. 9. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to FIGS. 1-7 which illustrate one preferred embodiment of the present invention, numeral 1 denotes an overedging machine, having a presser foot 2, a bed 3, and a throat plate 4. The numeral 5 denotes an air throttle valve, and 6 denotes a branch-connector. Upper nozzle tube 7 is made of metal, while the tube between the connector 6 and a connecton A is preferably made of rubber. The upper nozzle tube 7 is fixed to the upper side of the presser foot 2 by a set screw 8, such that the upper nozzle tube 7 moves up and down in association with up and down motion of the presser foot 2. The upper nozzle tube 7 is straight and parallel with the bed 3 from connection A to a connection B of the presser foot 2. Referring now to FIG. 2 and FIG. 3, the end of upper nozzle tube 7 has a U-shape portion 9 and a J-shaped portion 10. The J-shaped portion 10 extends horizontally and includes a leg 29. The leg 29 also constitutes a lower leg of the U-shaped portion 9. The spacing between the J-shaped portion 10 and the throat plate 4 is approximately the thickness of two sheets of cloth which comprise the workpieces to be sewed as shown in FIG. 4. J-shaped portion 10 is equipped with a nozzle 11 such that when air flows or is jetted from the nozzle 11 toward the edge of the workpiece, the air flattens the curl as shown in FIG. 4. A lower nozzle tube 12 runs from the branch-connector 6 to the under side of the bed 3 and is then turned up such that its opening, which is equipped with a nozzle 14, jets air to the edge of the workpiece to flatten the curl as shown in FIG. 4 and FIG. 5. The end of the lower nozzle tube 12 is supported by a lower-knife-slide-stud (not shown). This lower-knife-slide-stud is adapted to move in a direction normal to the direction in which the workpiece is fed such that the overedging width can be adjusted. Thus, the lower nozzle 14 moves only when the lower-knife-slide-stud moves for adjusting the overedging width. The end of the lower nozzle tube 12 is flush with the surface of throat plate 4; that is, is at the same level as the surface of throat plate 4. As shown in FIG. 3, the throat plate 4 is provided with U-shaped recess 13 such that the end of lower nozzle tube 12 is inserted therein as shown in FIG. 2 and FIG. 3. The operation of the preferred embodiment hereinbefore described is as follows: Referring to FIG. 4 and FIG. 6, which illustrate a situation where two sheets to be sewn together have oppositely curled edges 15 and 16, the two sheets are first overlapped. Then the presser foot 2 descends such that the J-shaped portion 10 of upper nozzle tube 7 touches the top workpiece. The curled edge 16 of the bottom workpiece extends over the edge 24 of throat plate 4 as shown in FIG. 4. When the sewing starts, both upper nozzle 11 and lower nozzle 14 jet air simultaneously. The air flow from the upper nozzle 11 flattens curled edge 15 of the upper workpiece. The air flow from the lower nozzle 14 flattens curled edge 16 of the lower workpiece. As the workpieces are fed, the J-shaped portion 10 of upper tube 7, which overlaps the curled edge 16 of the upper workpiece as shown in FIG. 4 and FIG. 6 further flattens the workpieces. Although most of the curl is flattened by air flow, a small curl may remain. It is the remaining small curl, if any, which will be flattened by the J-shaped portion 10 of upper nozzle tube 7. Referring to FIG. 5 and FIG. 7, where the ends of the workpieces curl toward one another, the upper workpiece is placed to cover lower leg 29 of the U-shaped portion 9 and the lower workpiece is placed under the lower leg 29 of the U-shaped portion 9. When the sewing starts, both upper nozzle 11 and lower nozzle 14 jet air simultanously. Both curled edge 17 in the upper workpiece and curled edge 18 in the lower workpiece are flattened by the air flow from the upper nozzle 11. As the workpiece is fed further, the curl 17 in the upper workpiece will be squeezed between the presser foot 2 and the lower leg 29 of the U-shaped portion 9. The curl 18 in the lower workpiece will be squeezed between the U-shaped portion 9 and the throat plate 4. As aforementioned, large curls will be flattened by the air flow and any smaller remaining curls will be flattened by the lower leg 29 of U-shaped portion 9. As previously described, where the edges are inwardly curled, air is jetted simultaneously from both upper nozzle 11 and lower nozzle 14. In another embodiment, it is possible to jet air only from the upper nozzle 11 by changing the branch-connector 6 to a branch connector which is capable of being switched so as to provide a flow of air to either the upper nozzle tube 7 alone, the lower nozzle tube 12 alone, or both simultaneously, as needed. Any suitable means of regulating air flow, such as a solenoid or pneumatic valve, can be used to create the appropriate flow of air through the branch connector. Although particular preferred embodiments of the present invention have been described herein, the present invention is not limited to these particular embodiments. Various changes and modifications may be made thereto by those skilled in the art without departing from the spirit or scope of the invention, which is defined by the appended claims. What is claimed is: 1. An apparatus for eliminating curls at the edge of a first fabric workpiece before sewing the first fabric workpiece to a second fabric workpiece along the curled edge on a sewing device having a vertically movable presser foot and a throat plate, the curl eliminating apparatus comprising:means for generating air flow; a first tube having a first end portion connected to said means for generating air flow and a second end portion fixed on the presser foot, said second end portion including an opening facing said curls and a contact portion extending horizontally and overlapping said curled edge of said first fabric workpiece for contacting with said curled edge when said presser foot moves downwardly; a second tube having a first end connected to said means for generating air flow and a second end situated under the throat plate and including an opening facing said curls, and a valve positioned between said means for generating air flow and first and second tubes for controlling air flow. 2. An apparatus for eliminating curls, as recited in claim 1, wherein said first end portion of said first tube has a flexible portion. 3. An apparatus according to claim 1 wherein said first tube further has an intermediate portion between said first and second end portions of said first tube, and said second end portion of said first tube further includes a vertical portion connecting said contact portion with said intermediate portion. 4. An apparatus according to claim 1 wherein said contact portion is positioned behind the presser foot in a feed direction of said fabric workpiece. 5. In a sewing machine, an apparatus for eliminating curl at an edge of a fabric workpiece comprising:a tube having an end portion including an opening for jetting an air flow facing said curl to flatten said curl and a contact portion which extends horizontally to overlap said curled edge of said fabric workpiece; and means for moving said tube vertically to bring said contact portion into contact with said fabric workpiece to additionally flatten said curl. 6. An apparatus according to claim 5 wherein said end portion of said tube is positioned behind a needle of said sewing machine in a feed direction of said fabric workpiece. 7. In a sewing machine, an apparatus for eliminating curl at an edge of a fabric workpiece comprising:means for generating air flow; a first tube having a first portion connected to said means for generating air flow, a second portion having an opening facing said curled edge for flattening said curl, and a third portion extending substantially straight between said first and second portion; said second portion including a contact portion horizontally extending below said third portion and overlapping said curled edge and a vertical portion connecting said contact portion with said third portion; means for moving vertically said second and third portions of said first tube to bring said contact portion in contact with said fabric workpiece to flatten said curl in addition to said first-mentioned flattening; and a second tube having an end connected to said means for generating air flow and an other end including an opening positioned under the throat plate and facing said curl. 8. An apparatus according to claim 7 wherein said first end portion of said first tube comprises a flexible portion. 9. An apparatus according to claim 7 wherein said contact portion is positioned behind a needle of said sewing machine in a feed direction of said fabric workpiece.

1988-10-31

en

1990-05-29

US-27068263-A

Materials handling tray Oct. 27, 1964 TWEED MATERIALS HANDLING TRAY 2 Sheets-Sheet 1 Filed April 4, 1963 Oct. 27, 1964 F. E. TWEED 3,154,197 MATERIALSHANDLING TRAY Filed April 4, 1963 2 Sheets-Sheet 2 United States Patent 3,154,197 MATERIALS HANDLING TRAY Francis E. Tweed, Reading, Pa., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Apr. 4, 1963, Ser. No. 270,682 8 Claims. (Cl. 211-126) This invention relates to a novel materials handling tray and, particularly but not necessarily exclusively, to a tray of this nature which is peculiarly adaptable for use in a substantially automated, multi-operation manufacturing process in conjunction with the effective and protective transportation and storage with minimum space requirements of structurally compatible articles therewithin. It is an object of my invention to provide a materials handling tray as above of economical and durable design and construction which embodies significant spacesaving features in the design thereof. A further object of my invention is the provision of a tray as above which incorporates complementary design features whereby a plurality of the trays may be efiectively interlocked and stacked for storage with minimum space requirements. Another object of my invention is the provision of a tray as above which incorporates self-contained article guide and support and locking features whereby structurally compatible articles may be effectively inserted, supported and maintained therewithin. In a preferred embodiment herein disclosed, the tray of my invention will be seen to be designed for the receipt and support of other structurally compatible material handling means, as for example the materials handling racks which form the subject matter of my copending application Serial No. 268,896, and to comprise an inverted, generally U-shaped frame member. Complementary shaped flanges and bent-over lip portions are formed at opposite extremities of the frame member whereby a plurality of the trays may be stacked in an interlocked relationship. Guide and support means, incorporating a self-locking design feature, are provided on opposite interior walls of the tray whereby the said materials handling means may be supported and maintained therewithin. The above and other objects and advantages of my invention are believed made clear by the following detailed description thereof taken in conjunction with the accompanying drawings wherein: FIG. 1 is a cross-sectional View taken through the center of the tray; FIG. 2 is an end plan View with the self-contained locks depicted in the closed position and includes the depiction of further materials handling means supported therewithin; FIG. 3 is an isometric view with the self-contained locks depicted in the open position, and FIG. 4 is a cross-sectional view of a plurality of the trays positioned in a stacked interlocked relationship. Turning now to the drawings, the herein-disclosed preferred embodiment of my invention will be seen to take the form of an inverted, generally U-shaped frame member 11 comprising top portion 12 with leg portions 13 and 14 extending therefrom. Handling flanges 16 and 17 are formed on the exterior surfaces of the respective leg portions and extend the entire lengths thereof whereby the trays may be conveniently gripped for handling. Flange-like leg portion extensions 18 and 19, and complementary shaped bent-over lip portions 21 and 22, respectively, are formed as shown at opposite ends of the leg portions whereby a plurality of the trays may be stacked in a stable interlocked relationship with minimum space requirements in the manner depicted in FIG. 4. 'ice Article guide and support means 23 and 24 are formed as shown on the interior walls of the leg portions whereby structurally compatible articles may be guided and supported therewithin. In the herein-disclosed preferred embodiment of my invention, these means will be seen to take the form of complementary shaped tongue and groove configurations, respectively, whereby the complementary shaped end portions of, for example, the materials handling rack of my aforementioned copending application, may be guided and supported thereby. In this regard, a rack 26 of this nature is depicted in FIG. 2 in the position assumed thereby within the tray. Diode stud assembly 27, comprising thin whisker leads 28, are in turn depicted as supported within the rack whereby it is made clear that the top portion 12 of the tray functions as a protective cover to prevent any damaging contact with the thin whisker leads of the diode stud assemblies supported within the tray. Further, it may be noted that the complementary shapes of the guide and support means of the herein-disclosed preferred embodiment, and the end portions of the racks, enable the former to function in the manner of a guide and rail system whereby the tray may be readily coordinated with the input and output stations of diode assembly machines and the racks automatically transferred between the trays and the said stations during the performance of a substantially automated, multi-operation diode manufacturing process. Self-contained profile locks 29 and 30 are seen in FIGS. 2 and 3 to be located in slots 31 at the ends of the leg portions, and to comprise guide and support means extensions 32 and 33, respectively, formed therein. The profile locks are slightly shorter than but otherwise iden tical in shape to the portions of the tray into which they are fitted, and are slidably attached thereto by pins 34 and locking screws 35 extending therebetween in the depicted mounting holes provided therefor. The locks may be positioned in either of the extreme upward position of FIG. 3the open positionor the extreme downward position of FIG. 2the closed position-by the manual adjustment thereof and tightening of the locking screws 35. Alternatively, the locks may be spring loaded in any obvious manner to either one of the above-mentioned positions whereby the manual adjustment thereof will become necessary only in those cases where the other position is desired. In the open position, the guide and support means extensions 32 and 33 are in alignment with the guide and support means to thus present a smooth profile to the insertion and withdrawal of the racks from the tray. In the closed position, the extensions are not in alignment with the guide and support means and thus function, in the manner depicted in FIG. 2, to prevent the Withdrawal of racks from the tray as should be obvious. Thus, it may be appreciated wherein the trays may be loaded with racks and the locks placed and tightened in the closed position whereupon the trays may be readily handled without fear of the racks falling therefrom. Significant space-saving features of my invention are believed made apparent by the design of the hereindisclosed preferred embodiment whereby it is seen that the extent of the tray is made just sufficient to maintain and protect the diode-loaded racks supported therewithin, while at the same time providing the desirable stacking, handling, and locking features set forth hereinabove. It should further become apparent that the design of the tray and the guide and support means may be readily modified in accordance with the size and shape of the articles to be supported and maintained therewithin whereby the size of the tray may be kept to an absolute minimum commensurate with the size of the articles. While I have described the herein-disclosed preferred embodiment of my invention in detail, it will become ob= vious to those skilled in this art, after reading this description, that various changes and modifications, in ad dition to those of size and shape mentioned hereinabove may be made therein without departing from the spirit and scope thereof. It is, therefore, intended that the matter contained in the foregoing description and annexed drawings be interpreted as illustrative only, and not in a limiting sense, when consideration is given to the appended claims. What is claimed is: 1. In a materials handling tray for the support of articles therewithin: a generally U-shaped frame member comprising a top portion and leg portions extending therefrom, said leg portions having interior and exterior surfaces, complementary shaped means formed at the upper and lower extremities of the leg portions whereby a plurality of the trays may be placed in an interlocked stacked relationship, and guide and support means formed on the interior surfaces of the leg portions below the top portion, 'said guide and support means having shapes which are complementary to the shapes of at least portions of V the articles to be supported within the trays whereby the said article portions may be interlocked with the guide and support means to thus guide and'support the articles within the tray. 2. In a tray as in claim 1 wherein: the said complementary shaped leg portions and the guide and support means are integral with and extend the entire lengths of the respective leg portions. 3. In a tray as in claim 1 further comprising: locking means formed on the leg portions whereby articles supported within the tray may be locked there- 1n. 4. In a materials handling tray for the support of articles therewithin: a generally U-shaped frame member comprising a top portion and integral leg portions extending downwardly therefrom, said leg portions having interior and exterior surfaces, integral flange-like extensions formed on the upper extremities of the leg portions at the junctures thereof of the top portions and extending upwardly therefrom, r a complementary shaped bent-over lip portions formed on the lower extremities of the leg portions whereby a a plurality of the trays may be placed in a stacked interlocked relationship by positioning the bent-over lip portions of one tray on the top .portion and between the fiange-like extensions of another, handle means formed on and extending from the exterior surfaces of the leg portions, and article guide and support means formed on the in terior surfaces of the leg portions, said guide and support means having shapes which are complementary to the shapes of at least portions of the articles to -be supported within the tray whereby 4 the said article portions may be interlocked with the guide and support means to guide and support the articles in a protected manner within the tray below the top portion thereof. 5. In a tray as in claim 4 wherein: the articles to be supported within the tray comprise materials handling racks. 6. In a tray as in claim 4 wherein: the flange-like extensions, the bent-over lip portions, and the guide and support means extend the entire lengths of the leg portions, and the leg portions further comprise locking means positioned at the ends thereof whereby articles supported within the tray may be locked therewit-hin. 7. In a materials handling tray for the support/there within of materials handling racks which comprise tongue and groove portions formed at opposite ends thereof, a generally U-shaped frame member comprising a top portion with two integral leg portions extendin downwardly from opposite edges thereof, said leg portions having interior and exterior surfaces in relation to the tray, flange-like extensions formed on and extending upwardly from the upper extremities of the leg portions at the 'junctures thereof with the edges of the top portion, complementary shaped hen-over lip portions formed at the lower extremities of the leg portions whereby a plurality of the trays may be placed in a stacked interlocked relationship by positioning the bent-over lip portions of one tray on the top portion and between the fiange-like extensions of another, article guide and support means formed on the interior surfaces of the leg portion, said guide and support means comprising tongue and groove configurations, respectively, of shapes complementary to the respective tongue and groove portions of the racks wherebythe latter may be interlocked with the former and guided and supported thereby within the tray, slots formed in the ends of the leg portions, and locking means'slidably mounted and movable therein to at least an open and a closed position whereby articles supported within the tray may be locked therewithin by movement of the locking means to the closed position. 8. In a device as in claim 7 wherein: the locking means comprise profile locks which include extensions of the guide and support means, said extensions being in alignment with the guide and support means in the open position of the locking means and not in alignment therewith in the closed position thereof; References Cited in the file of this patent UNITED STATES PATENTS 1. IN A MATERIALS HANDLING TRAY FOR THE SUPPORT OF ARTICLES THEREWITHIN: A GENERALLY U-SHAPED FRAME MEMBER COMPRISING A TOP PORTION AND LEG PORTIONS EXTENDING THEREFROM, SAID LEG PORTIONS HAVING INTERIOR AND EXTERIOR SURFACES, COMPLEMENTARY SHAPED MEANS FORMED AT THE UPPER AND LOWER EXTREMITIES OF THE LEG PORTIONS WHEREBY A PLURALITY OF THE TRAYS MAY BE PLACED IN AN INTERLOCKED STACKED RELATIONSHIP, AND GUIDE AND SUPPORT MEANS FORMED ON THE INTERIOR SURFACES OF THE LEG PORTIONS BELOW THE TOP PORTION, SAID GUIDE AND SUPPORT MEANS HAVING SHAPES WHICH ARE COMPLEMENTARY TO THE SHAPES OF AT LEAST PORTIONS OF THE ARTICLES TO BE SUPPORTED WITHIN THE TRAYS WHEREBY THE SAID ARTICLE PORTIONS MAY BE INTERLOCKED WITH THE GUIDE AND SUPPORT MEANS TO THUS GUIDE AND SUPPORT THE ARTICLES WITHIN THE TRAY.

1963-04-04

en

1964-10-27

US-40775095-A

Article depositing apparatus ABSTRACT A document processing system comprising a sensor array for sensing the size and position of a document; a movable magnetic scanner for scanning the document for coded information thereon; an imager for obtaining digitized image data of the document; a movable printing device for printing information on a document; a reversible document transport for conveying a document relative to the sensor array, the magnetic scanner, the imager, and the printing device; and a control unit connected to the sensor array, the magnetic scanner, the printing device and the document transport, the control unit controlling the movement of the document by the document transport between the sensor array, the magnetic scanner, the imager and the printing device, and further controlling movement of the magnetic scanner and the printer relative to the document transport. This is a divisional of U.S. patent application Ser. No. 08/004,829 filed on Jan. 15, 1993, now U.S. Pat. No. 5,422,467. FIELD OF THE INVENTION The present invention relates generally to an article depositing apparatus, and more particularly to an apparatus for receiving, processing and sorting envelopes and single document deposits. The invention is particularly suitable for an unmanned operation of accepting a deposit or receiving payments into a bank or like establishment, in conjunction with conventionally known automatic teller machines (ATM) and will be described with particular reference thereto. It is understood, however, that the present invention has other broader applications, and may be used to receive utility bills, notes, or other single sheet documents in other business situations. BACKGROUND OF THE INVENTION Automatic teller machines (ATM's) are widely used by banks and like establishments to provide unmanned cash dispensing to customers. Business transactions with ATM's are typically initiated by a customer using actuating keys on the ATM after the customer's identification has been established by means of a magnetic card having a customer's identification number and other pertinent information encoded thereon. ATM's have become extremely popular with banking and other financial institutions and their customers as a quick and convenient method of dispensing cash. However, for depositing money into a bank, or for paying utilities or like bills at a bank, it is generally necessary for such transactions to be handled by a bank teller during normal business hours. The present invention overcomes this and other problems and provides an article depositing apparatus for the acceptance of both envelopes and single document deposits, which machine can align and duplex single document deposits, sort deposits by kind, apply identification information to each deposit, magnetically scan and read single document deposits, obtain an image of one or both sides of a single document deposit, and the machine being compact and suitable for use with conventional ATM's. SUMMARY OF THE INVENTION According to the present invention there is provided a deposit processing module comprising a first transport having a first end for receiving envelopes and single document deposits and a second end from which the deposits are discharged, and a second transport operatively positioned for receiving and returning single document deposits to and from the first transport. Print means are provided for printing information onto each deposit, magnetic charge/read means are provided for charging and reading magnetic information and coded on the deposits and an imager is provided to obtain an image of one or both sides of the deposits. A gate mechanism associated with the second end of the first transport is movable between a first position wherein envelopes and single document deposits may be discharged from the module and a second position wherein single document deposits may be transferred between the first transport and the second transport. In accordance with another aspect of the present invention, there is provided a deposit processing device for receiving envelope deposits and single document deposits. The deposit processing device includes a deposit processing module having a deposit receiving end and a deposit discharge end. A first transport path extends from the deposit receiving end to the deposit discharge end and is dimensioned to receive envelope deposits or single document deposits. Printer means are disposed along the first transport path for printing information onto said envelope deposit or the single document deposit. A second transport path is provided adjacent the first transport path dimensioned to receive single document deposits. Magnetic scanning means are disposed along the second transport path for scanning a single document deposit for coded information thereon. Imager means are disposed along the second transport path for obtaining an image of a single deposit thereon. Conveyor means are provided for conveying envelope deposits and single document deposits along the first transport path and for conveying single document deposits along the second transport path. Gate means operatively connects the first transport path with the second transport path to permit single document deposits to be conveyed therebetween. The deposit processing device further includes a deposit storage module adjacent the deposit discharge end of the deposit processing module having a plurality of storage locations including at least one envelope storage location and at least one single document storage location. Means for moving the deposit processing module relative to the deposit storage module are provided to position the discharge end of the document processing module adjacent one of the storage locations together with means for duplexing single document deposits to permit scanning and imaging of both sides of a single document deposit. In accordance with another aspect of the present invention, there is provided a deposit processing module comprising a first transport having a first end for receiving envelope deposits and single document deposits and a second end from which the deposits are discharged. Printing means are disposed along the first transport for printing deposit information on the deposits. A second transport having an end positioned adjacent the second end of the first transport is provided for receiving and returning single document deposits to and from the first transport. A magnetic charge/read head is disposed along the second transport for charging and reading magnetic information on the single document deposits and an imager is disposed along the second transport for imaging one side of the single document deposit. A gate mechanism is associated with the second end of the first transport, the gate mechanism being movable between a first position wherein envelope deposits and single document deposits may be discharged from the processing module from the second end of the first transport and a second position wherein single document deposits may be transported between the first transport and the second transport. In accordance with yet another aspect of the present invention, there is provided a depository for receiving envelopes, checks, utility bills, or other sheet notes comprising a deposit storage module having a plurality of deposit storage locations therein and a deposit receiving module. The deposit receiving module includes a printer for printing deposit information on a deposit, a magnetic charge and read head for magnetically charging and reading coded information on a deposit and an imager for copying the surface of a deposit. The deposit receiving module has a receiving end for receiving deposits and a discharge end for discharging the deposits to the deposit storage module. Means are provided for pivoting the receiving module about a fixed axis among a number of positions corresponding to the deposit storage locations. In accordance with a still further aspect of the present invention, there is provided a deposit processing module comprised of an elongated platen having opposite facing elongated planar surfaces and an endless belt encircling the platen having a first belt run extending along one of the opposite facing elongated surfaces and a second belt run extending along the other of the opposite facing surface. Reversible drive means are provided for conveying the belt around the platen. A first plate means is disposed adjacent one of the opposite facing elongated surfaces in operative engagement with the first belt run to define a first transport. A second plate means is disposed adjacent the other of the opposite facing elongated planar surfaces in operative engagement with the second belt run to define a second transport. A gate member is provided at one end of the platen and being movable relative thereto, the gate member having a contoured surface positionable adjacent the belt for conveying deposits between the first transport and the second transport. In accordance with a still further aspect of the present invention, there is provided a deposit processing module having a deposit receiving end, a deposit discharge end, a first deposit transport path extending between the deposit receiving end and the deposit discharge end and a second deposit transport path having one end positioned adjacent the deposit discharge end. Printer means are provided for printing information onto a deposit, magnetic scanning means are provided for scanning a deposit for coded information thereon, and imager means are provided for obtaining an image of a deposit, the printer means, magnetic scanning means and the imager means being positioned along the first and second transport paths. Reversible conveyor means are provided for conveying a deposit along the first and second transport paths. A gate member is movable to a position wherein the first deposit transport path is connected to the second deposit transport path and means for pivoting the device about a fixed axis are provided to move the deposit discharge end to a plurality of locations. It is an object of the present invention to provide a deposit processing device for receiving envelopes and single document deposits. It is another object of the present invention to provide a deposit processing device as described above which can sort like documents and envelopes. Another object of the present invention is to provide a deposit processing device as described above which can apply transaction identification information onto the deposit in a configurable location. Another object of the present invention is to provide a deposit processing device as described above which can magnetically charge and scan a deposit for magnetically coded information thereon. Another object of the present invention is to provide a deposit processing device as described above which can scan a deposit and record the image on one or both sides thereof. A still further object of the present invention is to provide a deposit processing device as described above which can duplex a single document deposit. A still further object of the present invention is to provide a deposit processing device as described above which includes means for justifying a deposit along a registration edge. A still further object of the present invention is to provide a document processing device as described above which includes first and second linear transports which are generally parallel to each other and which together are angularly pivotable about a fixed axis. A still further objection of the present invention is to provide a deposit processing device as described above which is capable of sorting and storing deposits into a plurality of storage locations. A still further objection of the present invention is to provide a deposit processing device as described above which is capable of receiving deposits in other than a single orientation. A still further objection of the present invention is to provide a deposit processing device as described above which is compact in size and is separable to expose internal components for ease of serviceability. These and other objects and advantages will become apparent from the following description of a preferred embodiment taken together with the accompanying drawings. 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 in the specification and illustrated in the accompanying drawings which form a part hereof and wherein: FIG. 1 is an exploded perspective view of a deposit processing device illustrating a preferred embodiment of the present invention and showing a document processing module, a document storage module, and a main printed circuit board; FIG. 2 is an enlarged perspective view of the deposit processing module shown in FIG. 1; FIG. 3 is a schematic side elevational view of the deposit processing device shown in FIG. 1 showing one side of the device; FIG. 4 is a schematic side elevational view of the deposit processing device shown in FIG. 1 showing the other side of the device; FIG. 5 is a top, plan view of the deposit processing device shown in FIG. 1; FIG. 6 is an enlarged, partially broken away side elevational view of the deposit processing module and a portion of the deposit storage module showing the deposit processing module oriented to a top storage bin position; FIG. 7 is a side elevational view of the deposit processing module and deposit storage module showing an opposite view of that shown in FIG. 6; FIG. 8 is a top, plan view of the deposit processing module when positioned as shown in FIG. 7; FIG. 9 is a longitudinal sectional view taken along line 9--9 of FIG. 8; FIG. 10 is a plan view taken along line 10--10 of FIG. 9 showing portions of an upper transport; FIG. 11 is a plan view taken along line 11--11 of FIG. 9 showing portions of a lower transport; FIG. 12 is a sectional view taken along line 12--12 of FIG. 9; FIG. 13 is a sectional view taken along line 13--13 of FIG. 9; FIG. 14 is an end view taken along line 14--14 of FIG. 9; FIG. 15 is an enlarged view showing the gate mechanism; FIG. 16 is a fragmentary, further enlarged view of FIG. 9 showing the gate mechanism in a first position; FIG. 17 is an enlarged view showing the gate mechanism in a position for conveying a document between the upper transport and the lower transport; FIG. 18 is a view similar to FIG. 16 showing the document processing module in a gate full "up" position from which a single document may be sent to a select location or be received therefrom; FIG. 19 is an end elevational view taken along line 19--19 of FIG. 18; FIG. 20 is a schematic, perspective view showing motor drive arrangement for moving components of the document processing module. FIGS. 21A-21C are schematic views of the deposit processing device shown in FIG. 1 illustrating successive positions of the deposit processing module when an envelope deposit is processed; FIGS. 22A-22F are schematic views of the deposit processing device shown in FIG. 1 illustrating successive positions of the deposit processing module when a single document deposit process; FIGS. 23A-23D are schematic views of the deposit processing device as shown in FIG. 1, showing the successive positions of the deposit processing module when duplexing (i.e., inverting) a single document deposit; FIG. 24 is a perspective view of the deposit processing module showing the module opened for service; FIG. 25 is a block diagrammic representation of the electronic control system for the document processing device shown; FIG. 26 is a side elevational, sectional view of the receiving end of a document processing module according to the present invention, illustrating a modification to the document processing module to enable it to receive and process rigid or semi-rigid cards; FIG. 27 is a view taken along lines 27--27 of FIG. 26; FIGS. 28A and 28B are schematic views of the deposit processing module as shown in FIGS. 26 and 27, showing several positions of the deposit processing module when receiving a rigid or semi-rigid card; and FIGS. 29A and 29B are schematic views of a deposit processing module according to the present invention, together with an automatic document feeder for use therewith. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings wherein the showing is for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting same, the drawings show a compact, deposit processing apparatus 10 according to the present invention. Apparatus 10 is adapted to receive deposits such as envelopes containing currency or the like, and single document deposits, such as checks, utility bills, or other single sheet documents. In this respect, as used hereinafter, the term "deposit" shall generally refer to both envelopes and single sheet documents, the specific type of deposit being identified later in the specification when necessary to explain the operation of apparatus 10. Apparatus 10 is preferably for use in conjunction with a conventional automatic teller machine (ATM), wherein access to the ATM is by means of a conventional magnetic identification card. As will be appreciated from a further reading of the specification, however, apparatus 10 has other uses and applications and may find advantageous application in situations not involving ATMS or ATMS requiring credit card access. Apparatus 10 would typically be situated adjacent a housing facia 22 within a housing (not shown). Housing facia 22 includes a plate 24 having a deposit entry slot 26 which is accessible to a customer formed therein. In the drawings (see FIGS. 3 and 4), apparatus 10 is shown resting upon a support surface 28 which is schematically illustrated. An envelope storage bin 30 is positioned to one side and below apparatus 10 to receive and store envelope deposits which have been processed therethrough. Apparatus 10 is primarily comprised of a deposit processing module 12, and a deposit storage module 14 which is attachable thereto. Referring to FIG. 3, deposit processing module 12 is adapted to receive deposits through deposit receiving slot 26 and after processing same, to discharge the deposits into deposit storage module 14 or the envelope storage bin 30. Hereinafter, the end of deposit processing module 12 adjacent the housing facia shall be referred to as "the receiving end" or "front end" of the module, and the portion of the module adjacent deposit storage module 14 shall be referred to as the "discharge end" or "back end" of the module. Apparatus 10 is positioned so that the receiving end thereof is adjacent deposit entry slot 26. Broadly stated, deposit processing module 12 is generally comprised of three (3) sections or components, each of which is pivotally attached at one end to permit separation from each other for servicing as will be described in greater detail below. More specifically, deposit processing module 12 is generally comprised of an upper module section 100, a lower module section 200, and a transport and gate assembly 300 which is positioned therebetween. As shown in FIG. 2, upper module 100 is generally comprised of a support housing 102 having two spaced-apart, parallel sidewalls 104, 106. A spacer bar 108 and a cover plate 110 extend between sidewalls 104, 106. Sidewalls 104, 106 are formed to provide mounting surfaces for a transport motor 40, a pivot motor 50, and a shuttle motor 60. Transport motor 40 and pivot motor 50 are mounted to sidewall 104 with their respective drive shafts extending therethrough. Shuttle motor 60 is mounted on an inward extending panel 112 cut from sidewall 106. Adjacent to motors 40, 50 and 60, a printed circuit board 114 is provided and mounted on inward extending tabs (not shown) formed in the sidewalls 104, 106. A smaller printed circuit board 116 is provided at the discharge end of upper module section 100. Printed circuit board 114, 116 each include end portions which project beyond in sidewall 104, as best seen in FIGS. 1 and 2. Cover 110 (best illustrated in FIG. 9) is mounted to the sidewalls 104, 106 to enclose motors 40, 50, 60 and printed circuit board 114. The lower end 118 of cover plate 110 adjacent the receiving end of deposit processing module 12 is inturned toward the center thereof, as best seen in FIG. 9. Forming part of upper module section 100 is a floating plate 120. Floating plate 120 is generally U-shaped (as best seen in FIG. 13) and is dimensioned to be received between sidewalls 104, 106 of housing 102 of upper module section 100. In the embodiment shown, floating plate 120 is formed of a single metal sheet having the ends and sides bent to a desired configuration. In this respect, several components comprising the present invention, primarily the structural housings and support members, are preferably formed from single metal plates into complex shapes by cutting and bending such plates by conventionally known forming techniques. It is believed that the forming of such components is within the ability of those skilled in the art of metal forming and that the shapes of the components and how they may be formed is discernible from the drawings of the present invention. For this reason, and because the specific shapes of the structural components in and of themselves are not a primary aspect of the present invention, they shall not be described in great detail. A transverse slot 122, shown in FIG. 8, is formed in floating plate 120 to receive a printer shuttle 70. In this respect, portions of floating plate 120 along the sides of slot 122 are bent upward to define rails 124 which act as guides and mounting surfaces for printer shuttle 70. An auxiliary mounting bracket 126, shown in FIG. 9, is attached to the upper surface of floating plate 120 to provide an additional guide surface for printer shuttle 70 and to confine printer shuttle 70 within the slot 122. In this respect, the upper end of the auxiliary mounting bracket defines a generally L-shaped rail 126a along which printer shuttle may slide. The receiving end of the floating plate 120, i.e. the end of the floating plate adjacent the deposit receiving slot 26, has an upturned leading edge 128 which is formed to mesh with the inturned lower end 118 of cover plate 110. A centrally located, non-continuous rail 130 extends along the length of floating plate 120. Rail 130 is generally comprised of two (2) rail sections 132, 134 which are disposed on either side of slot 122. Rail sections 132, 134 project downward from the lower surface of floating plate 120, and are dimensioned to extend slightly below the lower surface of printer shuttle 70. The receiving end of rail 130 is upturned and dimensioned to extend into slots (not shown) in the inturned end 118 of cover plate 110. An idle guide roller 136 extends through a slot (not shown) in the leading edge of rail section 132. Guide roller 136 is mounted on a roller strut 138, shown in FIG. 12, which is mounted to rail section 132 and is pivotable relative thereto. Referring now to FIGS. 15 and 24, rail section 134 at the discharge end of floating plate 120 is best shown. Rail section 134 is comprised of a first portion 134a which is fixedly secured to floating plate 120 and a second portion 134b which is formed to be slidably received by portion 134a. Rail portion 134b is attached to a flexible deflector 150 which is provided at the discharge end of floating plate 120. Deflector 150 is preferably of a molded plastic construction and is shaped to be positioned on the upper surface of floating plate 120 and extend downward over the end thereof. A flat coiled leaf spring 152 secured to floating plate 120 biases the overextending end of deflector 150 downward to the position shown in FIG. 9. A rectangular pin 154 extends laterally outward from each side of deflector through rectangular slots 156 formed in sidewalls 104, 106 of housing 102, as shown in FIGS. 2 and 6. In this respect, deflector 150 is movable within support housing 102 on rectangular pins 154 sliding in slots 156 of sidewalls 104, 106. As shown in FIG. 9, deflector 150 is attached to rail portion 134b such that the free end of floating plate 120 is confined therebetween and slidable relative thereto. As a result, the discharge end of floating plate 120 is reciprocally movable, to a limited extent, toward deposit storage module 14, i.e. to the right in FIG. 9, in addition to being movable in a vertical direction (i.e. by movement of rectangular pins 154 in slots 156). The receiving end of floating plate 120 is likewise movable relative to housing 102. In this respect, the receiving end of floating plate 120 is mounted to housing 102 by means of pins 162 projecting outward from the sides thereof which pins 162 extend through inclined slots 164 in sidewalls 104, 106 of housing 102, as best seen in FIG. 7. Pins 162 which extend through sidewalls 104, 106 are attached by a helical spring 166 to pins 168 which are fixedly mounted to the outer surfaces of sidewalls 104, 106. In a similar respect, a pin 172 extends from the side of floating plate 120 past sidewall 104 and is connected by helical spring 174 to a pin 176 extending from sidewall 104, as best seen in FIG. 6. Springs 166, 176 bias floating plate 120 downward to a normal position, as generally shown in FIG. 9. Referring more specifically to printer shuttle 70, a conventionally known print head is mounted within printer shuttle 70 for marking deposits with transaction code and/or customer information. Printer shuttle 70 is formed to include a plurality of aligned slots to operatively receive rails 124, 126a. In this respect, printer shuttle 70 is adapted to be freely movable along rails 124, 126a. Referring to FIG. 6, the upper part of printer shuttle 70 includes an outward extending cam surface 72 which is positioned to engage a pin 74 mounted to a plate on housing 102. Pin 74 engages cam surface 72 when printer shuttle 70 is in a predetermined position within slot 122. In this respect, cam surface 72 and pin 74 are dimensioned to cause the printer shuttle 70 and floating plate 120 to move upward relative to the lower module section 200 and transport and gate assembly 300 of the document processing module 12 as will be described in greater detail below during the discussion of the operation of the present invention. Referring now to FIGS. 9, 11 and 13, lower module section 200 of document processing module 12 may be best seen. Lower module section 200 includes a generally U-shaped housing 202 comprised of a flat plate 204 and two (2) downward extending sidewalls 206, 208. A pair of flanges 212, 214, which are in planar alignment with sidewalls 206, 208, extend upward from the plate 204. In the embodiment shown, flanges 212, 214 are notched out from plate 204 and result in voids 216 being formed therein. Each flange 212, 214 includes an outward extending hub 218 which is in axial alignment with the other. The receiving end of plate 204 is formed into a triangular shape, best seen in FIG. 9, having a barrier portion 222 and a guide portion 224. Guide portion 224 of the plate 204 includes serrated edges to mesh with other module components (best seen in FIG. 10) as will be discussed later. In this respect, the discharge end of the plate 204 is also serrated (as best seen in FIG. 11) and formed to operatively interact with other module components. Two (2) generally parallel transfer slots 232, 234, best seen in FIG. 11, are formed into plate 204 and extend transverse to the longitudinal axis thereof. Slot 232 is dimensioned to a portion of a scanning imager 80. Scanning imager 80 is disposed below the plate 204 and between the sidewalls thereof with a scanning window 82 extending into the slot 232 and being flush with the upper surface of the plate 204. Slot 234 is provided to receive a magnetic ink character recognition (MICR) shuttle 90. To this end, portions of the plate 204 defining slot 234 are formed as spaced-apart rails 236 on which MICR shuttle 90 is mounted and can slide. Rails 236 are dimensioned such that the MICR shuttle 90 is flush with the upper surface of the plate 204. As best seen in FIG. 11, rails 236 are formed to extend beyond the sidewall 206 of the housing 202 to enable the MICR shuttle 90 to move sufficiently towards sidewall 206 such that the operative components of the MICR can magnetically charge or read information from a deposit position to that side of the plate. MICR shuttle 90 is comprised of a housing having slots dimensioned to receive the rails 236. The operative portion of the MICR head is designated 240 in the drawings. Adjacent the MICR head on MICR shuttle 90 a sensor 242 is provided. In the embodiment shown, sensor 242 is a retro-reflective sensor which is capable of detecting objects (i.e. sheet documents) passing thereover. Below MICR shuttle 90, a solenoid 250, best seen in FIG. 11, is mounted below plate 204. Solenoid 250 includes a reciprocally movable pin 252 and a sensor 254 (shown schematically in FIG. 25) to monitor movement of pin 252. Printed circuit boards 264, 266, which will be described in greater detail below, are mounted below plate 204 adjacent the distal ends thereof as seen in the drawings. Referring now to FIGS. 9-14, transport and gate assembly 300 are best shown. The transport and gate assembly 300 is generally comprised of an elongated, hollow, box-like platen 310 and a gate 410 which is pivotably mounted to the discharge end of platen 310. In the embodiment shown, platen 310 is formed from a generally U-shaped bottom member 312 and a flat top member 314 which are secured to each other (by means not shown) to form a structure having a rectangular, box-like cross-section as best seen in FIG. 13. The distal ends of platen 310 are serrated to operatively mesh with the components located adjacent the ends thereof. Specifically, the receiving end of platen 310 meshes with the serrations formed on guide portion 224 of plate 204, as shown in FIG. 10, and the discharge end of the platen 310 meshes with serrations formed on gate 410, which is best seen in FIG. 10. According to the present invention, a drive shaft 320 extends through the receiving end of the platen 310. As is best seen in FIG. 12, shaft 320 extends through bushings 322 mounted through the sides of the U-shaped bottom member 312 so as to enable platen 310 to be freely pivotally movable on drive shaft 320. Drive shaft 320 extends beyond the sides of platen 310 and includes a pair of outer bushings 324 which extend through the sidewalls 104, 106, 206, 208 of housing 102 of the upper module section 100 and the housing 202 of the lower module section 200. In this respect, the upper module section 100 and the lower module section 200 and the platen 310 are all pivotally mounted onto drive shaft 320, with the drive shaft 320 being freely rotatable relative to each. At one end of shaft 320, a tooth drive gear 332 is fixedly secured. A second tooth gear 334 is fixedly mounted near the middle of drive shaft 320. Gear 334 extends through slots formed in the upper and the lower surfaces of platen 310. Referring now to the discharge end of platen 310, a second shaft 336 is provided, as shown in FIG. 14. Shaft 336 extends through bushings 338 in the sides of U-shaped member 312 to facilitate free rotation of shaft 336 relative to platen 310. A tooth gear 342 is fixedly mounted to shaft 336 near the middle thereof to be in alignment with gear 334 on drive shaft 320. A pair of conical rollers 344 are mounted on shaft 336 for rotation therewith and are positioned on opposite sides of gear 342. A pair of gears 352, 354 are mounted on one end of shaft 336. As shown in FIG. 10, a timing belt 356 connects gear 352 to a gear 358 on a shaft 362 which extends through platen 310. A roller 364, which spans the width of platen 310, is mounted to shaft 362 for rotation therewith, as shown in FIG. 9. Shaft 362 and roller 364 are positioned to be above the track of MICR shuttle 90. Roller 364 extends slightly below the lower surface of platen 310 through a slot formed therein. As best seen in FIG. 10, a rail 368, which is aligned with and extends between the gears 334, 342 on the drive shaft 320 and shaft 336, projects from the upper surface of platen 310. Rail 368 is provided to support a continuous transport belt 370 which encircles platen 310 lengthwise. In this respect, transport belt 370 is mounted on gears 334, 342 of shafts 320, 336 respectively. Transport belt 370 has a first belt run 370a across rail 368 on the upper surface of platen 310 and a second belt run 370b along the lower surface of platen 310. Importantly, according to the present invention, shaft 336 and roller 364 are positioned within platen 310 such that a gap 380 is formed between belt run 370b and the upper surface of plate 204, as best seen in FIGS. 15 and 16. Gap 380 extends generally from the discharge end 18 of platen 310 to under MICR shuttle 90. Beyond MICR shuttle 90 to the receiving end 16 of platen 310, belt run 370b generally engages the upper surface of plate 204. Referring now to FIGS. 9, 10 and 15-17, gate 410 is best illustrated. Gate 410 includes a barrier portion 412 which extends across the front of platen 310, as shown in FIG. 10, and a pair of flat arms 414 which extend along the sides of the platen 310. Arms 414 are pivotally mounted to platen 310 on pins for pivotable rotation relative thereto. In the embodiment shown, arms 414 are generally J-shaped and are secured to barrier portion 412 by fasteners (not shown). Arms 414 project upward above the upper surface 310 of the platen and are joined to barrier portion 412 such that arms 414 extend thereabove. A tempered metal rod 416 extends from the sides of platen 310 up over the upper surface of barrier portion 412 and acts as a spring to bias gate 410 in a downward direction. In this respect, arms 414 are formed to include a lower edge 422, shown in FIG. 16, which acts as a stop against shaft 336 to limit gate 410 in its downward direction to neutral position as shown in FIG. 16. Arms 414 likewise include a second surface 424 which limits the upward movement of gate 410 through engagement with shaft 336, as shown in FIG. 18. Barrier portion 412 has a generally flat Upper surface 426 and is dimensioned such that upper surface 426 is aligned with the upper surface of platen 310 when the gate 410 is in the neutral (home) position. As best seen in FIG. 10, the ends of upper surface 426 are serrated to mesh with the edges of platen 310 and portions of deposit storage module 14. In addition, notches are formed in gate 410 to enable it to move without contacting the conical rollers 344 or transport belt 370, as shown in the drawings. When the gate 410 is in its neutral position, as shown in FIGS. 9 and 16, an upper discharge slot 430 is defined between the upper surface 426 of the gate 410 and the lower surface of deflector 150. Referring now to FIG. 15, barrier portion 412 includes an arcuate inner surface 432 facing and encompassing the end of platen 310. Arcuate surfaces 432 merges with a flat lower surface 434. A generally flat plate 436 is provided below barrier portion 412. In the embodiment shown, flat plate 436 is formed as part of arms 414. Plate 436 is spaced from lower surface 434 of barrier portion 412 and defines a lower discharge slot 440 therewith. The ends of lower surface 434 and of plate 436 are likewise serrated to mesh with the ends of platen 310 as well as components on deposit storage module 14. As best seen in FIG. 16, a curved, outward facing surface 442 is formed on the sidearm. Surface 442 faces towards the deposit storage module 14 and is recessed slightly below the outer facing surface of barrier portion 412. An inclined abutment surface 444 is formed at the upper portion of barrier portion 412 and merges with curved surface 442. As set forth above, upper module section 100, lower module section 200, and the transport and gate assembly 300 which have heretofore been described separately, are pivotally mounted to drive shaft 320, which is best seen in FIG. 24. Upper module section 100, the lower module section 200, and the transport and gate assembly 300 are adapted to be joined together in operative engagement with each other. To this end, pairs of latch elements 452, 454 (best seen in FIG. 6) are mounted on each side of housing 102 of the upper module section 100 to lock onto tabs 456 extending outward from the sides of the housing 202 of the lower module section 200. A release bar 458 spans sidewalls 104, 106 of housing 102 of upper module section 100 to connect the latch elements 452 on each side thereof. When united, upper module section 100 and platen 310 define a first transport therebetween, and lower section 200 and platen 310 define a second transport therebetween, which is best seen in FIG. 9. More specifically, a first transport is defined between floating plate 120 and the upper surface of the platen 310. In this respect, transport belt 370 is operatively disposed against rail 130 on floating plate 120 (i.e. envelopes and deposits) to capture documents therebetween and to transport the deposits along rail section 132, 134 on floating plate 120 between the receiving end and the discharge end of document processing module 12. The second transport is defined by the lower surface of platen 310 and plate 204 of housing 202 of the lower module section 200. In accordance with the present invention, document processing module 12 is pivotally mounted to a support frame 500, best seen in FIGS. 4, 6, 7 as 13. As shown in FIG. 13, support frame 500 is generally U-shaped and includes a bottom wall 502 and two (2) sidewalls 504, 506 which are generally parallel to each other and spaced apart to receive the document processing module 12 therebetween. Document processing module 12 is pivotally mounted to support frame 500 by means of pins 512 extending through sidewalls 504, 506 into hubs 218 on housing 202 of bottom module section 200. In the embodiment shown, a major portion of sidewall 504 is cut away to permit components of document processing module 12, such as the end shafts 336, 362 to extend therethrough, which is best seen in FIG. 2. As shown in FIG. 6, a gear block 522 having an arcuate rack gear 524 formed along the upper edge thereof is mounted to sidewall 504. Rack gear 524 is positioned to operatively engage a pinion gear 52 on the shaft of pivot motor 50. Adjacent gear block 522, sidewall 504 is formed to have a curved edge 532 having a plurality of notches and windows 534 formed therethrough. Sidewall 506 of the U-shaped support frame 500 includes a plurality of apertures, designated 550a, 550b, 550c, 550d, 550e, 550f, and 550g which are arranged in an arcuate pattern, as best seen in FIG. 7. Apertures 550a, 550b, 550c, 550d, 550e, 550f and 550g are positioned to receive pin 252 of solenoid 250 so as to lock deposit processing module 12 in one of a plurality of specific positions relative to deposit storage module 14, as will be described in greater detail below. Sidewalls 504, 506 each include locating notches 562 which are provided to locate and attach document storage module 14 to the document processing module 12. Referring now to FIG. 20, a schematic view of the motor drive assemblies for the respective components of the document processing module 12 is shown. In FIG. 20, the transport motor 40, and pivot motor 50 and shuttle motor 60 are all schematically illustrated. According to the present invention, each motor is preferably a reversible stepping motor wherein the relative rotational position of it may be monitored, and thus the position of components driven thereby may be monitored. As indicated above, transport motor 40 is mounted to sidewall 104 of upper module section 100 with its drive shaft extending therethrough. A gear 42 is mounted to the shaft of transport motor 40 to drive a timing belt 44 which connects gear 42 to gear 332 on drive shaft 320. In this respect, transport motor 40 is operable to rotate drive shaft 320 which in turn rotates shaft 336 by means of transport belt 370. Shaft 336 in turn drives shaft 362, and roller 364 thereon, by means of timing belt 356. Thus, transport belt 370, conical rollers 344 and roller 364 are simultaneously driven in the same direction by transport motor 40. As described above, pivot motor 50 is operable to drive pinion gear 52 across rack 524 on plate 522, which in turn is operable to cause deposit processing module 12 to pivot about axis A on pins 512 and to angularly orient deposit processing module 12 to one of the several positions 550a, 550b, 550c, 550d, 550e, 550f, 550g. Shuttle motor 60 is provided to reciprocally move printer shuttle 70 and MICR shuttle 90 across the width of platen 310. To this end, a drum 62 is mounted on the shaft of motor 60. The ends of a cable 64 are mounted to drum 62 and wound around drum 62 to enable cable 64 to be wound or unwound in each direction depending upon the rotation of shuttle motor 60. As shown in FIG. 20, cable 64 is wrapped over a system of pulleys, designated 66 in the drawings. Pulleys 66 are positioned to define form a continuous cable circuit, portions of which are adjacent, and run parallel to, the direction of movement of printer shuttle 70 and MICR shuttle 90. Idler pulleys 66 are mounted to drive shaft 320 to direct the cable therearound. Printer shuttle 70 and MICR shuttle 90 fixedly attached to cable 64 so as to move therewith. To monitor the operation of deposit processing module 12, as well as the position and configuration of deposits, a plurality of sensors are provided. According to the present invention, the sensors, and the circuitry associated therewith, have been arranged to facilitate ease of mounting and simple access thereto for maintenance purposes. In this respect, as set forth above, document processing module 12 includes a plurality of printed circuit boards 114, 116, 264, 266. As best seen in FIG. 9, the printed circuit boards 114, 264 are disposed at the receiving end of document processing module 12, and circuit board 114 being above and circuit board 264 being below platen 310. Circuit board 264 includes a pair of light emitters, designated 264a, 264b in the drawings, as best shown in FIG. 11. As best shown in FIG. 9, openings in plate 204, platen 310 and inturned portion of cover 110 permit a light beam to be directed from emitters 264a, 264b through the upper and lower transports towards a pair of light receivers 114a, 114b on opposing printed circuit board 114. In this respect, emitters 264a, 264b and receivers 114a, 114b are positioned to operatively align relative to each other, and each emitter and its respective receivers form an optical sensor. In like respects, at the discharge end of the deposit processing module 12, three (3) light emitters 266a, 266b, 266c are provided on the lower circuit board 266 to direct individual beams of light through openings in plate 204, platen 310 and floating plate 120 toward light receivers 116a, 116b, 116c on the circuit board 116. As shown in the drawings, emitters 264a, 264b, 266a, 266b and their respective receivers 114a, 114b, 116a, 116b are generally centrally disposed with respect to the center line of platen 310. Light emitter 266a and its related receiver 116a (not shown) is generally disposed along one edge of platen 310, as best seen in FIG. 11. In addition to the above-identified emitters and receivers, additional sensors are provided to monitor the relative position of selected components of deposit processing module 12. A generally U-shaped module rotation sensor 182, best seen in FIGS. 6 and 11, is provided to receive curved edge 532 of sidewall 504. Sensor 182 is operable to monitor the angular position of deposit processing module 12 by sensing the position of windows 534 with respect thereto. Conventionally known retro-reflective switches, shown schematically and designated 184 and 186 in FIG. 25, are also preferably provided to sense a home position for print shuttle 70 and for MICR shuttle 90, the home position being adjacent sidewall 104 of housing 102. A sensor 188 is also preferably provided to sense a "gate up" position, i.e. when gate 410 is in its uppermost position. An additional sensor, designated 190 in FIG. 25, may also be provided to indicate when latch elements 452, 454 are properly secured to ensure proper alignment and mating of the upper and lower module sections 100, 200 and transport and gate assembly 300. Still further, a sensor, designated 192 in FIG. 25 is also preferably provided on print shuttle 70 to sense the edge of a deposit for the purpose of locating print shuttle 70 relative to the deposit when information is to be printed thereon. As indicated above, light emitters 264a, 264b, 266a, 266b, 266c and light receivers 114a, 114b, 116a, 116b, 116c are mounted on printed circuit board 264, 266, 114 and 116, together with circuitry associated therewith. Circuit boards 114, 116, 264, 266 are connected to each other and to operatively engage components such as motors 40, 50, 60, printer shuttle 70, scanner imager 80 and MICR shuttle 90 by flex circuits (not shown) which can flex and bend as deposit processing module 12, and various components thereof, move and operate. A portion of the circuit boards 114, 116 extends beyond sidewall 104 of the document processing module 12, as best seen in FIG. 1. These extending portions of circuit boards 114, 116 include circuit lead lines to be received within female connectors 34 on a master circuit board 36. Master circuit board 36 is adapted to be mounted on spacer posts 38 extending outward from the document processing module 12, as best seen in FIG. 14, wherein the master circuit board 36 and a female connector 34 are shown in phantom. Referring now to FIG. 25, a block diagrammic representation of the internal control system for the document processing module 12 is shown. The physical operation of deposit processing module 12 are basically controlled by a central processing unit 600 which is programmed to control operations of the various components of deposit processing module 12 by means of a program stored therein. Central processing unit 600 is connected to light emitters and receivers, and to motors 40, 50, 60. Information received from stepping motors 40, 50, 60 and optical sensors enables central processing unit 600 to monitor the relative position of the components, as well as to identify and monitor deposits placed therein. Central processing unit 600 is connected to the printer within printer shuttle 70 to provide instructions and information to be printed on a deposit. Scanner imager 80 is connected to the control processing unit (CPU) of the ATM to receive information in coded form for present transmission to an external database, such as a bank or similar financial institution, or for display to the ATM user on the CRT of the ATM, or for storage within memory of the CPU of the ATM for transmission at a later time. Central processing unit 600 is likewise connected to the MICR read head to receive information typically present on checks or other similar documents in coded text. A separate decoding processing unit 610 is provided to decode and translate information obtained from a deposit to provide information identifiable to central processing unit 600 or to the external database. Referring to FIGS. 4 and 5, deposit storage module 14 is a rectangular, box-like structure having two spaced-apart parallel sidewalls 702, 704, a top wall 706, and a bottom wall 708. A plurality of spaced-apart shelves 712 extend between sidewalls 702, 704 to define compartments 714, 716, 718, 720. Sidewall 704, top wall 706 and bottom wall 708 are formed so as to define an open corner for access to compartments 714, 716, 718, 720. A side panel 722 is spaced-apart and mounted to sidewall 702. Mounting lugs 724 extend from sidewall 704 and panel 722 and are positioned so as to be received within mounting notches 562 on support frame 500 of deposit processing module 12. In this respect, mounting lugs 724 are provided to position deposit storage module 14 adjacent to deposit processing module 12. To ensure accurate positioning, and to maintain accurate alignment between the deposit storage module 14 and deposit processing module 12, latch elements 726, 728 are provided to operatively lock and hold deposit storage module 14 in engagement with deposit processing module 12. In the embodiment shown, compartments 714, 716 and 718 are adapted to receive single document deposits from deposit processing module 12, as shown in FIGS. 16 and 17. At the entrance to each compartments 714, 716, 718, a drive shaft 732 having a plurality of drive rollers 734 thereon is provided. Each drive shaft 732 extends between sidewalls 702, 704 and has one end which projects into the space defined between sidewall 702 and panel 722. A gear 736 is mounted on the end of each drive shaft 732 and meshes with a second intermediate gear 738 which is also confined between panel 722 and sidewall 702. Gears 738 of each compartment 714, 716, 718 are positioned to align and mesh with gear 354 on shaft 336 of platen 310. In this respect, drive shaft 732 and drive rollers 734 at the entrance to compartments 714, 716, 718 are driven by gear 354 on platen 310 when platen 310 is aligned with a specific compartment. Idle rollers 742 mounted on shafts 744 are provided above and in mating engagement with drive rollers 734. Deflectors 746 are provided between drive rollers 734 and idle rollers 742 to direct single document deposits into the associated compartment. The leading edges of the deflectors are serrated to mesh with the leading edges of platen 310. According to one aspect of the present invention, the lowermost compartment 720 is provided to enable document processing module 12 to duplex, i.e. to invert, single document deposits. To this end, a pair of drive shafts 752 are provided at the entrance to compartment 720. Each drive shaft 752 includes drive rollers 754 which mate with rollers 754 on the opposite drive shaft 752. A drive gear 756 is provided at the end of each shaft 752 and meshes with an intermediate gear 758 which is operable to engage gear 354 on shaft 336 of platen 310. Referring now to FIGS. 15-18, a pair of similar gate actuators 760 are mounted to the inner surfaces of sidewalls 702, 704. Gate actuators 760 are mounted on a pair of pins 762, 764 which are received in slots formed in each actuator 760. A biasing spring 766, having a predetermined spring force, urges actuators 760 upward to a neutral position as shown in FIG. 15. As shown in the drawings, the upper slot is generally L-shaped, while the lower slot is straight. Each actuator 760 is formed to have a pair of cam surfaces 772, 774 which are dimensioned to operatively engage and interact respectively with surfaces on gate 410 as will be described in greater detail below. In this respect, the slots in gate actuator 760 are configured such that when a downward force sufficient to overcome the biasing force of spring 766 is exerted on the inclined cam surface 772 of actuator 760, actuator 760 is forced downward and back (i.e. away from gate 410). In other words, one slot is inclined relative to the other slot to impart a slight rotation of actuator 760 as it moves downwards. In addition, the L-shaped slot allows actuator 760 to pivot backward about lower pin 764 when an upward force is exerted on lower cam surface 774, as will be described in greater detail below. Operation Referring now to the operation of the present invention, apparatus 10 is preferably integrated as part of an automatic teller machine (ATM), wherein access to apparatus 10 may be accomplished by using conventionally known magnetically coded cards and utilizing keypads typically provided on the ATM to establish the identity of a customer. Authorization to use apparatus 10 may be obtained from a remote, external database, such as in a bank or other financial institution or from records maintained in memory within the central processing unit of the ATM. Importantly, system and hardware for accessing apparatus 10 in and of itself forms no part of the present invention. Moreover, it will be appreciated after understanding the operation of the present invention, that apparatus 10, need not be part of an automatic teller machine (ATM), but may be used as a stand alone unit for other applications wherein access to the apparatus may be by means other than a magnetically encoded card. With respect to the operation and use of apparatus 10, deposit processing module 12 is adapted to operate in conjunction with deposit storage module 14. Importantly, according to the present invention, specific operations of deposit processing module 12 are accomplished through interactive engagement between the gate 410 of document processing module 12 and gate actuator 760 on deposit storage module 14. In this respect, according to the present invention, deposit processing module 12 is pivotally movable about axis A to a plurality of positions relative to deposit storage module 14. In the embodiment shown, deposit processing module 12 is movable to seven (7) specifically defined positions relative to deposit storage module 14. In each position, deposit processing module 12 is locked into proper alignment with deposit storage module 14 by means of pin 252 on solenoid 250 which projects into one of locating apertures 550a, 550b, 550c, 550d, 550e, 550f, 550g defined in sidewall 506 of support frame 500. In this respect, each aperture 550a, 550b, 550c, 550d, 550e, 550f, 550 g in support frame 500 represents a specific position of deposit processing module 12. For the purposes of illustrating operation of the present invention, in FIG. 7, each aperture 550a, 550b, 550c, 550d, 550e, 550f, 550g has been identified with respect to the function of deposit processing module 12 in such position. In general, the upper three (3) apertures 550a, 550b, and 550c are positions for depositing single document deposits into compartments 714, 716, 718 of deposit storage module 14, aperture 550a also being a "home position" for deposit processing module 12. Aperture 550d represents a single document deposit "aligning position" and a position wherein single document deposit is conveyed between the upper transport and the lower transport. Aperture 550e represents a gate full "up" position and a position wherein single document deposits are conveyed from the lower transport to pinch rollers 754 and visa versa. Aperture 550f represents a "facia-aligned position". This position also allows document deposits to be sent or received from pinch rollers 754 to the upper transport. Aperture 550g represents an "envelope deposit position". FIG. 4 generally shows deposit processing module 12 in the "facia-aligned position" for receiving a deposit, but also shows the range of movement of deposit processing module 12 by illustrating (in phantom) the positions of transport belt 370, (i.e. platen 310) would assume when document processing module 12 is in its extreme, uppermost and lowermost positions. As discussed previously, apparatus 10 is adapted to receive envelope deposits which may contain currency or other documents of value, or single document deposits, such as checks, utility bills, or other notes of value. With the present invention, envelope deposits are handled differently than single document deposits. Accordingly, hereinafter "envelope deposits" shall be referred to as such and designated "ED" in the drawings, and deposits such as a check, utility bills, or some other single note of value shall be referred to as a "single document deposit" and designated "DD" in the drawings. Referring now to the processing of a deposit, an authorization signal to allow access to apparatus 10 is conveyed to central processing unit 600 from an external source. As indicated above, such signal may be received from an automatic teller machine (ATM), a bank, or other financial institution or some other source. Once central processing unit 600 has received instructions to accept receipt of a deposit, central processing unit 600 instructs pivot motor 50 to pivot deposit processing module 12 about axis "A" to move same to the facia-aligned position, a position illustrated in FIG. 4. More specifically, pivotal movement of deposit processing module 12 is accomplished by pinion gear 52 being driven over arcuate rack gear 524. The relative position of deposit processing module 12 is monitored by central processing unit 600 based upon information received from stepping motor 50 and from information received from angular position sensor 182. With such information, central processing unit 600 may determine the relative location of deposit processing module 12 relative to deposit receiving slot 26 in housing facia 22, as well as the relative position of deposit processing module 12 relative to deposit storage module 14. When deposit processing module 12 has pivoted to the "facia-aligned position", pivot motor 50 is stopped and solenoid 250 is actuated such that pin 252 thereon extends through aperture 550f in support housing 500. In this respect, deposit processing module is thus locked and aligned into a deposit receiving position, wherein the upper transport is aligned with deposit receiving slot 26 through housing facia 22. With deposit processing module 12 in the "facia-aligned" position, central processing unit 600 initiates transport motor 40, to initiate movement of transport belt 370 in a direction to draw a deposit into the upper transport. According to the present invention, deposit processing module 12 is capable of identifying the type of deposit inserted therein, i.e. envelope deposit ED or single document deposit DD, by means of the optical sensors provided at the receiving end of deposit processing module 12. In this respect, as the leading end of the deposit enters the upper transport, it passes between light emitters 264a, 264b and light receivers 114a, 114b. According to the present invention, emitters 264a, 264b and receivers 114a, 114b, are positioned and have operational characteristics wherein they are capable of providing to central processing unit 600 information as to the length, width and opacity (which provides an indication of thickness) of the inserted deposit, with which central processing unit 600 can identify whether the deposit is an envelope or single document based upon such information. If an envelope deposit ED is detected, transport motor 40 proceeds to transport drive belt 370 to convey the envelope deposit ED to a position under printer shuttle 70. Envelope deposit ED is drawn along rail 130 of floating plate 120 through frictional engagement with transport belt 370. Importantly, because transport belt 370 and rail 130 on floating plate 120 project above their respective surfaces, the upper transport has ample clearance on either side of transport belt 370 (i.e. between floating plate 120 and platen 310) to facilitate the passage of envelope deposits ED which have lumps or enlargements to one side of drive belt 370. More importantly, because upper plate 120 effectively "floats" relative to housing 102 of upper module section 100, and may move away from transport belt 370, the upper transport can accommodate the passage of relatively thick envelope deposits ED. Importantly, floating plate 120 not only moves upward away from transport belt 370 to receive thick deposits, it also shifts in the direction of movement of the thick deposit. In this respect, slots 164, through which pegs 162 extend, are slanted to allow floating plate 120 to shift upward and in the direction of movement of the deposit. Such movement is facilitated because the dispensing end of floating plate 120 may slide between deflector 150 and rail section 134a. Central processing unit 600 is programmed to position the envelope deposit below printer shuttle 70 by controlling transport motor 40. Positioning envelope deposit ED below printer shuttle 70 can be accomplished by using the optical sensors, i.e. light emitters 266a, 266b, 266c and light receivers 116a, 116b and 116c to establish when the leading edge of the envelope deposit has reached the discharge end of deposit processing module 12. With the envelope deposit ED positioned below printer shuttle 70, central processing unit 600 may activate shuttle motor 60 to position print head 70 to a desired location relative to the envelope deposit ED. Shuttle motor 60 is operable to move printer shuttle 70 transverse to the path of envelope deposit ED by wrapping cable 64 onto drum 62. At this point, it should be noted that operation of shuttle motor 60 also moves MICR shuttle 90 along its respective track. In this respect, printer shuttle 70 and MICR shuttle 90 move in tandem across platen 310. A proximity sensor (not shown) adjacent one side of deposit processing module 12 is used to establish a "home position" for both printer shuttle 70 and MICR shuttle 90. The central processing unit 600 activates pivot motor 50 to rotate deposit processing module 12 to the lowest position, i.e. the envelope deposit position as schematically illustrated in FIG. 21C. In this position, gate member 410 is in its neutral, lowermost position wherein the upper discharge slot 430 of gate 410 is aligned with the first transport. Transport motor 40 is then actuated to drive the envelope deposit ED into envelope storage bin 30 for later retrieval by a bank employee or otherwise authorized individuals who can verify the content of the envelope deposit against the information entered by the user by retrieving the transaction information from memory of central processing unit 600. Information is printed onto envelope deposit ED by passing envelope deposit ED beneath printer shuttle 70 (by means of transport belt 370) and simultaneously activating the print head within printer shuttle 70. The information printed onto envelope deposit ED would typically include a transaction number, the date and/or other coded information relating to the transaction and/or customer. As will be appreciated, the information printed on the envelope deposit ED is likewise maintained in memory or transferred to an external database for later retrieval. Referring now to FIGS. 22A-22F, the processing of a single document deposit is illustrated. When a single document deposit such as a check or utility bill is inserted into the deposit receiving slot, it is drawn into the upper transport (the document processing module being in the facia aligned position) and conveyed toward the printer head. As the document deposit DD passes between light emitters 264a, 264b and receivers 114a, 114b at the receiving end of the transport, the deposit is identified as a single document by means of the optical sensors which, as indicated above, scan the deposit as to its thickness, i.e., its opacity. Once the deposit is identified as a single document deposit DD, the document deposit, when necessary, is "justified" or "aligned", i.e. moved toward the edge of platen 310 near sidewall 104 of housing 102. According to the present invention, "justification" or "alignment" of the document deposit DD is accomplished by first identifying the amount and direction of misalignment of document deposit DD. This is accomplished utilizing light emitters 266a, 266b and 266c and receivers 116a, 116b and 116c. In this respect, if document deposit DD is misaligned, the leading edge of document deposit DD will be conveyed by transport belt 370 past each corresponding pair of light emitters 266a, 266b and 266c and receivers 116a, 116b and 116c at a different time. By sensing when the sequence and time when each light beam is broken, and knowing the speed the document deposit is being conveyed along the transport path by belt 370, central processing unit 600, by processing a trigonometric calculation can determine the amount and direction of misalignment of document deposit DD. Specifically, it can determine whether the leading edge of document deposit DD is away from side wall 104 (i.e. with the trailing edge being near side wall 104) or whether the trailing edge of document deposit DD is angled away from side wall 104. Once the position of the document is established, "justification" or "alignment" of the document is generally accomplished by repeatedly transporting the misaligned end of document deposit DD, i.e. the end of the document outermost or furthest from side wall 104 over conical rollers 344, shown in FIG. 10, between the upper and lower transport. To this end, document processing module 12 is moved to its "aligning position", best seen in FIG. 17 and schematically illustrated in FIG. 22C. As shown in FIG. 17, when document processing module 12 is in its "aligning position", cam surface 772 of gate actuator 760 engages abutting surface 444 of gate 410 and forces gate 410 upward into a position wherein arcuate deflecting surface 432 of gate 410 is aligned with the upper surface of transport belt 370. In this respect, biasing spring 766 on actuator 760 has sufficient spring force to counteract the biasing effect of tempered rods 416 which bias gate 410 to a downward position. Shuttle motor 60 is actuated to move printer shuttle 70 (together with the MICR shuttle 90) to a position where cam surface 72 on shuttle housing 70 rides up onto pin 74 extending from support housing 102 to lift floating plate 120 away from the single document deposit. Plate 120 is lifted away from belt 370 to reduce the friction drive exerted by belt 370 on document deposit DD. In this respect, in its normal position, i.e. plate 120 resting on transport belt 370, a "high frictional drive" condition exists between the deposits and transport belt 370 to drive deposits along the first transport. With plate 120 lifted away from transport belt 370, a "low frictional drive" condition exists between transport belt 370 and the deposit. A "low frictional drive" is required to enable conical rollers 344 to shift a document deposit DD toward side wall 104. In this respect, conical rollers are designed to exert a relatively small lateral force, in the order of 1 ounce, on document deposit DD. This relatively small lateral force is necessary to avoid forcing and crumbling the document deposit DD into side wall 104. Because the force of conical rollers 344 is so small, the frictional force exerted on document deposit DD by transport belt 370 must be removed to enable the document deposit DD to be moved by conical rollers 344. If a document deposit DD is misaligned and the leading edge of the document deposit DD is disposed away from side wall 104, document deposit DD is conveyed by transport belt 370 to a position where the leading edge thereof is over conical roller 344. Transport motor 40 is then repeatedly driven, first in a forward direction and then in a reverse direction, to repeatedly convey the leading edge of single document deposit DD over conical rollers 344. Arcuate surface 432 of gate 410 causes the leading edge to be guided around the end of platen 310 between the respective transports. As the leading edge of the single document deposit DD is reciprocally conveyed over conical rollers 344, the tapered surfaces of such rollers 344 causes the leading edge of the document deposit DD to shift towards one side of platen 310. The optical sensor comprised of light emitter 266a and light receiver 116a which are positioned along the edge of platen 310, as best seen in FIG. 14, indicate when the single document deposit DD is aligned along the edge of platen 310. The document deposit is considered "aligned" or "registered" along the edge of the platen when eighty percent (80%) of the deposit is determined to be along the edge of platen 310. The inner surface of side arm 414 of gate 410 acts as a step and prevents the edge of the document deposit from shifting past the edge of platen 310. If a document deposit DD is misaligned and the trailing edge of document deposit DD is oriented away from side wall 104, the document deposit DD is conveyed from upper transport to the lower transport until such trailing edge is over conical roller 344. In this position, the leading edge of the document deposit DD would be captured between MICR shuttle 90 and transport belt 370, and a major portion of the document would be within gap 380 which is defined between transport belt 370 and plate 204. Importantly, gap 380 creates a "low friction drive" condition such that when the trailing edge of document deposit DD is repeatedly driven over conical rollers 344, the trailing edge is forced into alignment by conical rollers 344 in a manner as described above. In this respect, the leading edge of the document deposit DD, which is captured between MICR shuttle 90 and transport belt 370, experiences a "high frictional drive" condition which generally maintains the leading end of the document deposit in its original position as the trailing edge is conveyed into alignment by conical roller 344. With respect to the aforementioned aligning process, the relative position of the document deposit during alignment is monitored by means of the optical sensors, i.e. emitters 266a, 266b, 266c and receivers 116a, 116b, 116c, provided along the discharge end of the transports together with the sensor 242 mounted to the MICR shuttle 90. Once the document deposit is aligned along the edge of platen 310, it is then conveyed from the upper transport to the lower transport as illustrated in FIG. 22D, again utilizing arcuate surface 432 of gate 410 as a guide. As the document deposit DD is driven into the second transport, it passes over MICR shuttle 90 wherein the MICR head is energized to magnetize the document deposit wherein any code number thereon would be magnetized. In this respect, documents such as checks or utility bills typically include information set forth thereon in an ANSI standard bar code, wherein the bar code is printed with a magnetizable ink. Information typically found on commercial checks or utility bills would include: (1) institutional information regarding the institution issuing the check or bill, (2) an account number, and (3) a check number, bill number or statement number relating to the particular document. Larger institutions may also include (4) the amount of the check or bill, as part of the bar code information. As the document deposit passes over the MICR head, it also passes over window 82 of scanner imager 80. As it does so, an image of the downward facing side of the document deposit is obtained and conveyed to central processing unit of the ATM via the scanner card for storage in memory, or is immediately transferred to external memory at the bank or financial institution. In this respect, transport belt 370 conveys the entire document deposit over image scanner 80. When the leading edge of the document deposit has reached the optical sensors at the receiving end of lower transport, transport drive motor 40 is reversed to convey the document deposit back over the MICR head so that the above-identified magnetized, coded information may be removed therefrom. Generally, the coded information is typically provided at specific locations on a certain type of document. Central processing unit 600 is programmed to position the MICR shuttle 90 initially to a location wherein the coded information would be expected on the document deposit. In the event that the coded information is not found where expected, central processing unit 600 causes transport belt 370 to continually reverse itself to pass the document over the MICR shuttle 90, while at the same time, causing shuttle motor 60 to relocate MICR shuttle 90 along its rails to a position wherein the coded information might be found. In other words, central processing unit 600 is programmed to reposition the MICR head to search the document for the coded information. When the appropriate information has been obtained from the document, such information may be immediately transferred to the external memory of the financial institution, stored in memory by the central processing unit of the ATM to be downloaded to an external central database at a later time, or utilized in an immediate transaction with a customer. Once the appropriate information is obtained from the document deposit, the document deposit is transported by transport belt 370 back to the upper transport as illustrated in FIG. 22E, again using arcuate surface 432 of gate 410 as a guide. As the document deposit is returned to the upper transport, transaction information is printed thereon as it passes beneath print shuttle 70. With the information obtained from the document deposit DD, and utilizing either present instructions stored in memory, or instructions provided from an external source such as a central computer in a financial institution or the like, central processing unit 600 would select one of the three compartments 714, 716, 718 of deposit storage module 12 into which document deposit DD is to be conveyed. With the desired compartment identified by central processing unit 600, pivot motor 50 is actuated to cause document processing module 12 to be pivoted into alignment with the desired compartment. As document processing module 12 moves from its "deposit aligning position, as shown in FIGS. 17 and 22E, toward one of the three (3) compartments 714, 716, 718, as shown in FIG. 22F (wherein the upper transport is aligned with compartment 716) and FIG. 16 (wherein the upper transport is aligned with compartment 714), gate 410 moves past gate actuator 760. In this respect, the upper end of gate actuator 760 merely pivots about pin 764 out of the way of the lower portion of gate 410 as it moves thereby. Importantly, as gate 410 moves away from, and out of engagement with, gate actuator 760, gate 410 is permitted to return to its normal (down) position wherein the upper discharge slot 430 of gate 410 is in alignment with the upper transport. Referring now to FIG. 16, the relative positions of platen 310 and gate 410 of document processing module 12 when in alignment with compartment 714 of deposit storage module 14 are shown. In this position, the upper transport is in alignment with compartment 714 such that a document deposit conveyed from the upper transport would be directed between the drive rollers 734 and idle rollers 742. Importantly, intermediate gear 738 which meshes with gear 736 on drive shaft 732 operatively engages gear 354 on the end of shaft 336 on platen 310. Thus, as transport belt 370 is being driven by transport motor 40 and simultaneously rotates shaft 336 through platen 310 and gear 354 on end thereof which engages and drives gear 738. Gear 738 in turn drives rollers 734. The document deposit is thus caught between rotating drive rollers 734 and idle rollers 742, and conveyed into compartment 714. When the trailing end of the document deposit has passed the optical sensors at the discharge end of platen 310, transport motor 40 continues to operate for a predetermined period of time to ensure that the document is conveyed entirely into compartment 714. In this respect, a document deposit can be conveyed into any of the upper three (3) storage compartments in a similar manner. For example, FIG. 22F schematically illustrates a document deposit being driven into compartment 716. As shown in the drawing, transport belt 370 is driven to convey the document deposit toward the deposit storage module 14 wherein drive roller 734 at the entrance to the compartment with idle rollers 742 catch the leading edge of the document deposit and pull the document deposit into the compartment. In accordance with another aspect of the present invention, apparatus 10 includes means for "duplexing" or inverting a document deposit therein. Such feature is particularly applicable when a document deposit has been placed into document processing module 12 in an improper orientation, or merely to reorient a document deposit so as to enable both sides of the document deposit to be scanned or imaged by the MICR shuttle 90 or by the image scanner 80. In this respect, FIGS. 23A-23D illustrate a procedure for "duplexing" a document within document processing module 12. In this respect, originally a document deposit would typically be processed discussed above. In this respect, the document deposit would first be "aligned" in a manner as previously described. It would then be conveyed from the upper transport (as shown in FIG. 23A) to the lower transport (as shown in FIG. 23B) to locate and obtain information from a bar code or magnetic code on the document deposit. In the event that the document has been inserted improperly into the document processing module, i.e. upside down, the MICR head would be unable to locate or read the bar code (which would be facing platen 310). If the MICR head is unable to locate or read a bar code, central processing unit 600 would initiate the "duplex" procedure. To duplex the document deposit, central processing unit 600 would initiate pivot drive motor 50 to move document processing module 12 from its aligning position as shown in FIG. 17 to its "duplex position" as shown in FIG. 18. In this position, surface 772 of gate actuator 760 has caused gate 410 to move to its uppermost position. In this respect, spring 766 which is attached to gate actuator 760 has a spring force greater than the biasing force exerted by spring rods 416 on gate member 410, and therefore moves gate 410 upward wherein lower discharge slot 440 (i.e. the slot defined by lower surface 434 of gate 410 and lower plate member 436) of gate member 410 is in alignment with compartment 720. In this position, gear 354 at the end of shaft 336 operatively engages intermediate gear 758 associated. with upper drive shaft 752. Transport motor 40 is then initiated to cause transport belt 370 to convey the document deposit toward drive rollers 754 at the entrance of compartment 720, as illustrated in FIG. 18. Importantly, the position of the trailing edge of the document deposit is monitored as it is being conveyed from the lower transport into lower compartment 720. In this respect, transport motor 40 is shut off once the document deposit has exited lower discharge slot 440 of gate 410. Importantly, the end of the document deposit is maintained between drive rollers 754 at the entrance to compartment 720 as illustrated in FIG. 23C. Once the document deposit has cleared the lower transport, central processing unit 600 causes pivot motor 50 to move document processing module 12 from its "duplex position" to the "facia-aligned position", as illustrated in FIG. 9, wherein the upper transport is essentially aligned with lower compartment 720. In this respect, document processing module 12 is moved from its "duplex position" to the "facia-aligned position", gate actuator 760 is forced backward by abutting surface 444 of gate member 410. In this respect, spring 766 which biases gate actuator 760 does not have sufficient strength to resist the overall movement of document processing module 12. Accordingly, as described above, gate actuator 760 moves downward and shifts to the rear to enable gate 410 to move thereby when document processing module 12 moves to a lower position, i.e. the "facia-aligned position" or the "envelope deposit position". In the "facia-aligned position", document processing module 12 is oriented such that drive gear 354 on shaft 336 through platen 310 is in operative engagement with intermediate gear 758 connected to the lower set of drive rollers 754. In this position, transport motor 40 is actuated to cause the document deposit to be conveyed from lower compartment 720 into the upper transport, as schematically illustrated in FIG. 23D. With the document deposit conveyed back into the upper transport, the optical sensors on the discharge end of document processing module 12 indicate when the trailing end of the document deposit has entered the upper transport. Central processing unit 600 then instructs the document processing module 12 to return to the "aligning position" wherein the document deposit may be transported from the upper transport to the lower transport in a manner as previously discussed. As will be appreciated, as the document deposit is conveyed from the upper transport to the lower transport, the side of the document which was originally facing away from image/scanner 80 and MICR shuttle 90 is now facing image/scanner 80 and MICR shuttle 90. In this position, it may be magnetically charged and read, or imaged in a manner as previously discussed. With the appropriate information obtained and after transaction information is printed thereon, the document deposit is then conveyed to one of the storage compartments 714, 716, 718, as discussed above. The invention as heretofore described, thus provides a single document processing apparatus capable of receiving envelope deposits; as well as document deposits such as checks, utility bills, or other valued notes. More importantly, an apparatus according to the present invention can scan, image and print onto one or both sides of a document deposit and accomplishes such scanning, imaging and printing, utilizing only one magnetic read head, one image/scanner and one print head. In this respect, the ability to duplex a document deposit reduces the necessity of duplicate components. Moreover, the use of a bi-directional transport as well as a movable MICR head and print head enables the present invention to read account code information off documents inserted to the document processing module in any orientation. In addition, the movable shuttles, particularly the MICR shuttle 90, enable variable print locations on deposited documents to be located and scanned. With respect to the alignment mechanism., the use of conical shaped rollers and a bi-directional transport enables justification and straightening of documents against the registration edge for searching the location of coded information on deposits. Still further, by justifying the document around a curved path (i.e. between the upper transport and the lower transport) document rigidity is ensured to provide better transport and alignment of all types of sheet material. More importantly, the present invention accomplishes the foregoing by a relatively simple, compact mechanism. In this respect, a single common belt drive conveys documents through both the upper and lower transport. In addition, the pivotable document processing module enables storage of like documents in specific compartments and bins and simplifies transporting of documents by .means of a gate which is movable by means of rotation of the document processing module. In addition to processing sheet document deposits DD and envelope deposits ED, a document processing module 12 according to the present invention is also capable of processing rigid or semi-rigid cards such as a laminated driver's license or a plastic identification card. In this respect, the receiving end of document processing module 12 may be modified to include a rectangular slot 802, as seen in FIGS. 26 and 27. Slot 802 is formed in barrier portion 222 of plate 204 and is positioned to be in registry with the second transport, which is defined by plate 204 and the lower surface of platen 310. Referring now to FIGS. 28A and 28B, document processing module 12 is shown in its "envelope deposit position." In this position, slot 802 is in registry with deposit entry slot 26 in housing facia 22. A rigid or semi-rigid card, which is designated CD in the drawings, may be inserted into the second transport through slots 26 and 802. Card CD is captured between transport belt 370 and plate 204, and may be conveyed by transport belt 370 over scanner/imager 80, where an image of the card CD may be obtained. In this respect, document processing module 12 may be used to copy and store identification information or authorization information from a rigid or semi-rigid card CD. Upon completion of the imaging, card CD would be returned to the user by reversing drive belt 370. As will be appreciated, card. CD could include magnetic information in coded form which could be read by the MICR head. Still further, according to the present invention, card CD may be transferred from the second transport to the upper transport to print thereon, in a manner similar to that described above to transfer sheet document during the duplexing procedure. In this respect, document processing module 12 would be moved to its "duplex position", as shown in FIG. 18. Transport motor 40 is then initiated to cause transport belt 370 to convey card CD between drive roller 754 at the entrance of compartment 720, the trailing edge of card CD being held between drive roller 754. Document processing module 12 is then moved to its "facia aligned position", as illustrated in FIG. 9, and card CD is conveyed into the first transport, where information may be printed onto the upward facing side of card CD. To return card CD to the customer, the sequence is reversed and card CD is conveyed from the first transport into bin 720 where its trailing edge is held by rollers 754, and then from roller 754 into the second transport from where it may be returned to the customer. This present invention thus provides a document processing device which can receive and return an identification card or authorization card from a customer, and is capable of scanning such card for magnetic information, obtaining an image of such card and printing information onto such card. Referring now to FIGS. 29A and 29B, a document feeding mechanism for picking a document from a stack and conveying the individual document to document processing module 12 is schematically shown. In this respect, in some applications it may be desirable to utilize a document processing device according to the present invention to automatically process a stack of like documents. For example, a bank may wish to identify, image and sort checks drawn on accounts maintained at the bank. To this end, an automatic document feeder 900 is shown. Document feeder 900 includes a tray 902 for receiving a stack of documents DD to be processed. A picker roller 904 is provided at the bottom of tray 902 to remove single documents from the bottom of the stack. Roller 904 includes a gear 906, which meshes with an intermediate gear 908. Intermediate gear 908 is positioned to mesh with a gear 910 provided on shaft 320 of document processing module 12. When document module 12 is in its "facia-aligned position", gear 910 meshes with intermediate gear 908 as shown in FIG. 29A. As transport belt 370 is driven, gear 910 drives intermediate gear 908 which in turn drives gear 906 on picker roller 904. Picker roller 904 conveys a single document into first transport. Once the document is within. document processing module 12, document processing module 12 is pivoted to another position such that gear 910 disengages intermediate gear 908. The document may then be processed in any preset manner and conveyed to a storage location as shown in FIG. 29B. A deposit processing device as described above finds advantageous application with a conventional automated teller machine (ATM) for processing checks and/or utility bills. A conventional ATM would typically include a display monitor having a screen for displaying information to a customer, a card reader for reading information from an identification card, and a keypad for use by a customer for inputting information. A customer with an ATM card would access the ATM by inserting the card into the card reader and then utilizing the keypad to insert a personal identification code. Magnetic information on the ATM card would typically include the customer's name and an account number. Through a menu driven user interface, the customer may use the keypad (or touch designated areas on the screen) to input instructions to the ATM's central processor. According to the present invention, if a check is to be cashed by a customer, the scanner/imager of the deposit processing module would scan the face of the check in a manner as described above. The scanning process creates digital image data which would be conveyed to the ATM's central processor. According to a predetermined program, one or more select fields of information from the digital image data can be displayed on the monitor screen of the ATM. Specifically, in a check cashing procedure, the field showing the amount of the check is preferably displayed for the convenience of the customer. All or part of the check may then be cashed by the customer, with any remaining balance being credited to the customer's account. As indicated above, some institutional checks would include the amount of the check within the bar coded information thereon. In such situations, the central processor may compare the amount requested for withdrawal by the customer with the amount of the check and proceed with the currency dispensing if the amount requested by the customer is within the value of the check. In situations where the amount of the check is not within the bar coded information, a computer program may be provided wherein the digital image data information provided to the ATM is analyzed to determine the amount of the check. In this respect, the characters set forth in the "check amount" field would be analyzed to determine the amount of the check. Once the amount of the check is determined, the ATM's central processor again compares the amount requested by the customer with the amount of the check to determine whether sufficient funds exist therein to proceed with the check cashing procedure. A less complex program may be provided wherein the digital image data is analyzed to determine the number of characters preceding a delimiter character, i.e. the decimal point, in the identified "check amount" field. For example, the processor may determine that two numbers exist before the decimal point in the check amount field. With this information, the computer can recognize that the maximum amount of the check could be $99.99 and the minimum amount of the check would be $10.00. With this range of value, the central processor would analyze the amount requested by the customer. If the amount requested falls within the acceptable range, and if sufficient funds exist within the customer's account to overcome any possible shortfall in the amount of the check, the ATM may authorize cashing of the check for the amount requested by the customer. Thus, the ATM processor could be programmed to analyze general information and compare such information to a customer's account and base an authorization or denial of check cashing based upon programmed criteria. In addition to the foregoing advantages, the present invention, through its specific design, lends itself to easy maintenance by being pivotally hinged at one end wherein the operative components of the document processing module are accessible. In this respect, FIG. 24 shows how the upper and lower module sections 100, 200 may be separated from each other and from the transport and gate assembly 300. The present invention thus provides a document processing module which is compact and extremely versatile. As indicated above, the present apparatus is capable of receiving envelope deposits, rigid or semi-rigid cards, and more importantly, may receive document deposits such as checks, utility bills, or other valued notes. Importantly, with respect to single document deposits, the versatility of the present apparatus facilitates receipt of a wide range of varied types of document deposits and the ability of the document processing module to duplex the document facilitates financial transactions heretofore unavailable with existing devices. The present invention has been described with reference to a preferred embodiment. Other modifications and alterations will occur to those skilled in the art upon a reading and understanding of the present specification. It is intended that all such modifications and alterations be included insofar as they come within the scope of the appended claims or equivalents thereof. Having thus described the invention, the following is claimed: 1. A document processing system comprising:sensor means for sensing the position, thickness, width and opacity of a document; magnetic scanning means for scanning said document for coded information thereon; imaging means for obtaining digitized image data of said document; memory means for storing said digitized image data obtained by said imaging means; printing means for printing information on said document; transport means for conveying a document past said sensor means, said magnetic scanning means, said imaging means, and said printing means; a processing means for controlling said document processing system, said processing means being connected to said sensor means, said magnetic scanning means, said imaging means, said memory means, said printing means and said transport means; and an ATM, connected to said processing means, including input means for inputting a user identification code and an input value, a display means, and a cash dispensing means. 2. A document processing system as defined in claim 1, wherein said processing means identifies image data corresponding to a predetermined field of said digital image data stored in said memory means, and displays said identified image data on said display means. 3. A document processing system as defined in claim 2, wherein said processing means computes a maximum value based upon a determination of a number of characters preceding a delimiter character in said identified image data. 4. A document processing system as defined in claim 3 wherein said processing means compares an input value input by a user through said input means to said maximum value, in order to determine whether to dispense cash to said user through said cash dispensing means. 5. A document processing system as defined in claim 3, wherein processing means searches a remote memory means, and retrieves user data corresponding to a user identification code input by said user through said input means. 6. A document processing system as defined in claim 5 wherein said processing means determines whether to dispense cash to said user through said cash dispensing means based upon said maximum value, an input value input by a user through said input means, and said user data. 7. A document processing system comprising:a sensor array for sensing the size and position of a document; a magnetic scanner for scanning a document for coded information thereon; an imager for obtaining digitized image data of a document; a memory storage device for storing said digitized image data obtained by said imager; a printing device for printing information on a document; a reversible document transport for conveying a document to said sensor array, said magnetic scanner, said imager, and said printing device; a control unit for controlling said document processing system, said control unit including a system for receiving user information and a display for displaying information to a user, said control unit being connected to said sensor array, said magnetic scanner, said memory storage device, said printing device and said transport means. 8. A document processing system as defined in claim 7, wherein said control unit identifies image data corresponding to a predetermined field of said digital image data and stores said data in said memory storage device. 9. A document processing system as defined in claim 8, wherein said control unit computes a value based upon a determination of a number of characters preceding a delimiter character in said identified image data. 10. A document processing system as defined in claim 9, wherein said control unit compares an input value entered by a user to said value, in order to determine whether to dispense cash to said user through a cash dispenser. 11. A document processing system as defined in claim 9, wherein said control unit searches a remote memory storage device, and retrieves user data corresponding to a user identification code entered by said user. 12. A document processing system as defined in claim 11, wherein said control unit determines whether to dispense cash to said user based upon said maximum value, an input value entered by a user, and said user data. 13. A document processing system comprising:a sensor array for sensing the size and position of a document; a movable magnetic scanner for scanning said document for coded information thereon; an imager for obtaining digitized image data of said document; a movable printing device for printing information on a document; a reversible document transport for conveying a document relative to said sensor array, said magnetic scanner, said imager, and said printing device; and a control unit connected to said sensor array, said magnetic scanner, said printing device and said document transport, said control unit controlling the movement of said document by said document transport between said sensor array said magnetic scanner, said imager and said printing device, and further controlling movement of said magnetic scanner and said printer relative to said document transport. 14. A document processing system comprising:a magnetic scanner for scanning said document for coded information thereon; an imager for obtaining digitized image data of a document; a printing device for printing information on a document; a reversible document transport for conveying a document relative to said magnetic scanner, said imager, and said printing device; a duplexing assembly communicating with said document transport for inverting a document relative to said document transport, wherein both sides of said document can be exposed to said magnetic scanner, said imager and said printing device; and a control unit connected to said magnetic scanner, and said imager to receive information therefrom, and further connected to said document transport and said duplexing assembly for controlling the movement and orientation of a document on said document transport. 15. A document processing system comprising:a sensor array for sensing the dimensions of a document and the position thereof; a magnetic scanner for scanning a document for coded information thereon; an imager for obtaining digitized image data of a document; a printing device for printing information on a document; a reversible document transport for conveying a document relative to said sensor array, said magnetic scanner, said imager, and said printing device; a plurality of storage locations for storing documents; means for moving said sensor array, said magnetic scanner, said imager, said printing device and said document transport as a unit relative to said plurality of storage locations wherein said document transport is operably alignable with each of said storage locations to deposit documents therein; and a control unit connected to said sensor array, said magnetic scanner and said imager for receiving information therefrom, and connected to said printing device, said document transport, and said means for moving for controlling the movement of a document on said document transport and the positioning of unit relative to said plurality of storage locations. 16. A document processing system comprising:a reversible document transport for reciprocally moving a document along a predetermined path; a plurality of storage locations alignable with said document transport; a sensor array for sensing the dimensions and position of a document; a magnetic scanner movable across said path for scanning a document for coded information thereon; an imager disposed along said path for obtaining digitized image data of a document; a printing device movable across said path for printing information on a document; a control unit connected to said sensor array, said magnetic scanner, said imager, said printing device and said document transport, said control unit controlling the movement of a document along said path by said document transport and further controlling movement of said magnetic scanner and said printer relative to said path to operatively position same relative to a document on said document transport. 17. A document processing system comprising:a magnetic scanner for scanning a document for coded information thereon; an imager for obtaining digitized image data of a document; a printing device for printing information on a document; a reversible document transport for conveying a document relative to said sensor array, said magnetic scanner, said imager, and said printing device; a duplexing assembly communicating with said document transport for inverting the orientation of a document relative to said document transport, wherein both sides of said document can be exposed to said magnetic scanner, said imager and said printing device; a plurality of storage locations for storing documents; and means for moving said magnetic scanner, said imager, said printing device and said document transport as a unit relative to said plurality of storage locations wherein said document transport is operably alignable with each of said storage locations to deposit documents therein.

1995-03-21

en

1996-07-09

US-34539982-A

Electrodeposition of chromium ABSTRACT Trivalent chromium is electrodeposited from an aqueous bath in which are dissolved very small proportions of compounds of classes (I) compounds containing ##STR1## group, preferably a thiocyanate or a compound of formula X--CSNR where X is R, S or, NR 2 or is --CSNR 2 joined by --S-- or --S--S-- and R is H, alkyl, alkenyl, alkynyl or aromatic: (II) compounds of formula (X)--SO 2 --(Y) in which X is (a) a saturated or unsaturated two or three carbon atom alpiphatic group terminating in a mercapto group or (b) the disulphide corresponding thereto, of formula Y--(SO 2 )--X--S--S--X(SO 2 )--Y or (c) single unsubstituted benzene ring; and Y is --ONa, --OH, --NH 2 or when X is a single unsubstituted benzene ring, a direct --NH-- linkage or indirect --NH--CO-linkage to the ortho position thereof, (III) compounds of formula HOOC --(CH 2 ) n --S m (CH 2 )COOH where n or m is 1 or 2; (IV) o-mercaptobenzoic acid and (V) sodium salts of sulphur, selenium and tellurium. The invention relates to the electrodeposition of chromium from aqueous electrolytes containing trivalent chromium ions. Conventionally chromium has been electrodeposited from solutions containing hexavalent chromium with a small quantity of sulphuric acid. However, hexavalent chromium can present serious environment and health hazards, the solution itself being highly toxic and corrosive. Also it has long been characterised as having poor throwing power, limited covering power and low electrical efficiency whilst being sensitive to current interruptions resulting in so called "white-washing" of the deposit. To overcome these disadvantages, at least in part, chromium electroplating baths based on trivalent chromium complexes have been formulated. Such plating baths have excellent throwing power and are tolerant to current interruption. However, the colour of the plate obtainable is often darker than that obtained from hexavalent chromium baths, so that there has hitherto only been a limited commercial exploitation of such baths containing trivalent chromium complexes. One prior proposal is to electrodeposit from a solution in which the Cr+++ ions are complexed with thiocyanate, using Cr:NCS molar ratios of between 1:1 and 1:6, preferably about 1:2, to optimise efficiency and colour and minimise undesired gas emission. Because the thiocyanate complex forms only slowly, it was essential to heat the chromium salt solution with the thiocyanate at 80° for 2 to 4 hours at a controlled pH to equilibrate it prior to use in electrodeposition. In contrast to this, it has now been discovered that very low concentrations of thiocyanate can be utilised without prior equilibration and that moreover other usually sulphur-containing, and preferably organic compounds (not hitherto used in chromium electrodeposition) can now be used as additives at equivalently low levels to give effective and acceptable electrodeposits. The concentration of such compounds is, according to the invention, always lower than the 1:1 ratio previously described for the thiocyanate complexes, and is preferably one or more orders of magnitude lower, so that it appears that a different mechanism is involved from the bulk formation of thiocyanate complex throughout the whole solution. Possibly there is rapid, equilibrated, complex formation, decomposition and reformation in the immediate vicinity of the depositing layer of metal, so that the small amount of this compound has an effectively catalytic effect, but the Applicants do not intend to limit their invention by any hypothesis as to the mode of action. While according to the invention the sulphur-containing compound is present in less than the 1:1 proportion, so that it cannot form a complex with all of the trivalent chromium present, it is possible although not necessary for other complexing agents of different type to be present. Uncomplexed trivalent chromium ion is green in colour, and is generally present in the practice of our invention. In one aspect therefore the invention provides an electroplating solution containing trivalent chromium ions together with a dissolved compound of the classes I to V listed below, in a proportion less than equimolar in relation to the trivalent chromium ions. The relative molar concentration of the trivalent chromium to the compound is always more than the 1:1 ratio mentioned in respect of thiocyanate complexes in the prior art and is usually more than 1:0.1, many compounds being effective at considerably higher chromium ratio of 1:0.01 or 1.0.001 or in some cases even more. In practice the chromium ion concentration will usually lie within the range 0.01 to 1.0 molar. Correspondingly, the compounds will usually be present in amounts from 1 to 500 milligrams per liter, more especially 10 to 100 mg/l. Preferably, the compound will be organic and sulphur-containing. Class I compounds as defined herein consists of those compounds with an ##STR2## group within the molecule. Preferably, these are either a thiocyanate in salt or ester form or a compound which can be expressed by the formula: ##STR3## wherein X is either (a) --R, --S or --NR2 or (b) represents another group of the formula ##STR4## linked to the first by --S-- or --S--S--; the R group being the same or different and chosen from hydrogen; straight or branch chain alkyl, alkenyl, or alkynyl groups, and mononuclear or binuclear carbocyclic aromatic groups, R being either unsubstituted or substituted by a carboxylic acid group or a salt or ester thereof. The organic compounds should be water soluble. Usually therefore they will be of relatively low molecular weight (e.g. less than 300) so that R is preferably hydrogen or preferably at most possesses not more than six carbon atoms for example C1 to C3 alkyl. Specific compounds suitable for use in accordance with class I of the present invention include: ##STR5## The organic compounds described above can be used in combination with one another. Class II of compounds according to the invention consists of compounds of formula (X)--SO2 --(Y) in which X is (a) a saturated or unsaturated two or three carbon atom aliphatic group terminating in a mercapto group or (b) the disulphide corresponding thereto, of formula Y--(SO2)--X--S--S--X(SO2)--Y or (c) a single unsubstituted benzene ring; and Y is --ONa, --OH, --NH2 or when X is a single unsubstituted benzene ring, a direct --NH-- linkage or indirect --NH--CO linkage to the ortho position thereof. Specific compounds of utility in Class II are: sodium allyl sulphonate CH2 ═CH CH2 SO3 Na, sodium vinyl sulphonate CH2 ═CH SO3 Na, mercaptopropane sulphonic acid HS--CH2 CH2 CH2 SO3 H, bis-(sodium sulphopropyl)disulphide HO3 S--CH2 CH2 CH2 --S--S--CH2 CH2 CH--SO3 H, benzene sulphonamide C6 H5 SO2 NH2, thiamazole of formula ##STR6## or saccharin of formula ##STR7## All of the above compounds possess a sulphonic or sulphonamide group attached to a simple short-chain mercapto-containing group or to a single unsubstituted benzene ring. It seems possible that the practice of the invention depends on the formation of transient deposition-affecting species near the layer of deposition, and we have found that departure from the definition of Class II compounds e.g. by substitution of the benzene ring, is not advisable. Thus, certain naphthalene compounds (2,7-naphthalene disulphonic acid, the naphthalene trisulphonic acids) do not work effectively. Moreover, the alkyl-substituted toluene-4-sulphonamide or toluene-4-sulphonic acid are also not very effective. The same applies to the bis-benzene sulphonamides or the benzene-m-disulphonic acid. The more complex ring systems e.g. 5-sulphosalicylic acid, 3(benzothiazolyl-2 mercapto)-propyl sulphonic acid and 1-(β-hydroxyethyl) 2-imidazolidine thione also do not give as satisfactory results. Moreover, in relation to the alkyl compounds, the corresponding hydroxy-compound i.e. isethenic acid HO--CH2 --CH2 --SO3 --H is not of primary interest. If decomposition products are involved in the process of the invention it may be that an increase in complexity of the initial material gives undesirable reactions at the deposition layer. Class III of preferred compounds consists of the compounds of formula HOOC--(CH2)n --Sm --(CH2)n --COOH where n or m is 1 or 2. Preferred examples are dithiodiglycollic acid and thiodiglycollic acid. Once again, departure from this category of compound is inadvisable. A higher member of the series, thiodipropionic acid of formula HOOC--CH2 CH2 --S--CH2 CH2 COOH is less effective than the lower members. Class IV of preferred compounds is similar to Class III, and consists in the compounds of formula: ##STR8## where Z is a water-solubility-conferring group e.g. --COOH, --OH or --SO3 H. The aromatic ring linkage between for example the --COOH and the --SH groups appears to give an effective product. All of the above organic compounds, of classes I to IV are inter-related in that they possess either one or more thiol groups, or groups electrochemically related thereto. Class V of compounds is not organic but inorganic and consists of the sodium salts of acids of sulphur, selenium and tellurium from the list comprising metabisulphite, dithionite, sulphide, selenate, selenite, tellurate and tellurite. A buffering agent may be present and may comprise boric acic or one or more borates. Alternatively, or additionally, one or more other buffering agents may be present, for example a carboxylic acid or a carboxylic acid salt such as citrate, tartrate, malate, formate or acetate. To increase the conductivity of the electrolyte solution and hence reduce the power consumption required for chromium electrodeposition, conductivity salts may be added. These are desirable but not essential and so may vary in concentration from zero to saturation. Typical conductivity salts are salts of alkali or alkaline earth metals with strong acids for example chloride or sulphate of potassium or sodium. Ammonium ions may also be useful in increasing conductivity and also may provide some buffering action. It is preferable that the solution be acidic since at a pH greater than 4.5 chromium may be precipitated from solution. Below pH 1.5 some loss in coverage may occur and the plating rate may decrease. The optimum pH range is from about 2.5 to about 4.0. Wetting agents or surfactants are desirable, though not essential, since they may increase coverage and plating rates. Typical concentrations range from 0.1 to 10 grams per liter. The choice of wetting agent is not as critical as in hexavalent chromium baths since the solution of the present invention is not as highly oxidising. Indeed, those wetting agents frequently employed in nickel electroplating baths may be used in the solution of the present invention for example, sulphosuccinates such as sodium dihexylsulphosuccinate or alcohol sulphates such as sodium 2-ethylhexyl sulphate. Antifoaming agents may also be added. A particular preferred form of the solution of the present invention comprises trivalent chromium ions, the water-soluble organic compound as described above, both borate and a buffer other than borate, a conductivity salt, and a wetting agent and be formulated in a hydrogen concentration to afford the appropriate pH less than 4.5. The presence of incidental amounts of other organic or inorganic species is acceptable if they do not affect the plating to an undesirable extent. The solution cannot however tolerate a large amount of hexavalent chromium and it may be necessary to add a suitable reducing agent, for example a bisulphite, formaldehyde, glyoxal or more especially a sulphite e.g. as sodium sulphite, to convert hexavalent chromium to trivalent chromium. This treatment may be necessary particularly if the solution is to be used directly in contact with an inert anode since oxidation of trivalent chromium to hexavalent chromium can occur on electrolysis. The bath may conveniently be made up by dissolving water-soluble salts of the required inorganic species, and salts or other suitable water-soluble forms of the organic species in sufficient water to afford the required concentration. Preparation of the bath may be accomplished at room temperature though it is preferable to heat the solution to about 50° C. to increase the rate of dissolution of the solid species. Another aspect of the present invention is an electroplating process in which a workpiece (preferably a metal workpiece) is immersed in a solution as described above and an electric current is passed through the solution from a compatible anode to the workpiece as a cathode whereby there is produced an electrodeposited chromium plate. Use of this process can give light coloured electrodeposits similar in appearance to those obtained from solutions containing hexavalent chromium values. The operating temperature of the solution of the present invention is preferably from 10° to 90° C., e.g. 40°-60° C. 50° C. is considered optimum. Current densities between 1 and 100 amperes per square decimeter may be employed and 10 amperes per square decimeter may be considered as optimum. If the pH of the solution during operation varies outside the recommended range, control may be accomplished by addition of, for example, hydrochloric or sulphuric acids or of, for example, sodium, potassium or ammonium hydroxide. During operation of the process it may be advantageous to separate the anode from the solution by a layer of inert material having a porous structure of the type that provides low permeability to the passage of liquids and low resistance to the passage of electric current. Alternatively an ion-selective membrane can be used. The insulating effect should not however be excessive. Such procedures are preferably if chloride or other halide ions are present in the solution. It will be appreciated that the low organic content of the solution simplifies the effluent treatment after the plating process. Another aspect of the invention is constituted by an article having on at least one surface thereof a chromium electrodeposit produced by the process described above. A further aspect of the invention is a dry mix or concentrated solution of materials, suitable for dissolution in water, or suitable for dissolution in an existing electroplating bath to replenish desired constituents, so as to provide an electroplating solution as described above. This may for example comprises a trivalent chromium salt, a conductivity salt, boric acid and the water-soluble organic compound in relative proportions such than when the dry mix is dissolved in water to a trivalent chromium ion content between 0.01 and 1.0M, the buffered pH lies between 1.5 and 4.5 and the organic compound is dissolved in the bath in a chromium ion:organic ratio of greater than 1:0.1. It can be used to make up the initial bath by dissolution in water using a wetting agent. A replenishment additive preferably contains the chromium salt and the organic compound in higher proportions than those intended for bath operation to compensate for degradation in use. For example, an additive containing an organic compound:chromium ion ratio in a 1:65 weight ratio has been found generally useful as a replenishment additive, about 200 gm/Ampere-hr being utilised, preferably being made up as a concentrated solution prior to addition. The invention will be further illustrated by the following examples. EXAMPLE 1 The following species were dissolved in water and the resulting solution diluted to 1 liter with water. Chrometan (containing 16.2% chromium): (Chrometan is the proprietary name for a commercially available mixture containing chromium sulphate and sodium sulphate): 10 g Boric acid: 60 g Potassium sulphate: 100 g Sodium 2-ethyl hexyl sulphate (40% solution): 1.0 ml The chromium content was therefore 1.62 g (32.2 millimoles). The pH of the solution was adjusted to 3.2 and the solution was heated to 50° C. A Hull cell test using a platinised titanium anode and a brass cathode was carried out on the solution for 3 minutes at a total current of 5 amperes. A very poor plate was produced i.e. a discoloration of the brass panel was seen and not a metallic coating. Addition of 100 milligrams per liter of thiourea (m.w. 76) to the solution (i.e. 1.32 mM) and repeating the Hull cell test gave a bright uniform chromium electrodeposit having an attractive light colour. The chromium:thiourea molar ratio was 1:0.0423. EXAMPLE 2 A solution as given in example 1 was made up, but 50 milligrams per liter (0.67 mM) of thioacetamide m.w. 75 was added instead of thiourea. A Hull cell test produced a bright uniform chromium electrodeposit having an attractive light colour. The chromium:thioacetamide molar ratio was 1:0.0214. EXAMPLE 3 A solution as given in example 1 was made up but 50 milligrams per liter (0.625 mM) of sodium thiocyanate of m.w. 80 were added instead of thiourea. A Hull cell test produced a bright uniform electrodeposit having an attractive light colour. The chromium:thiocyanate molar ratio was 1:0.02. EXAMPLE 4 The following species were dissolved in water and the resulting solution diluted to 1 liter with water. Chrometan: 100 g Boric acid: 60 g Malic acid: 10 g Potassium sulphate: 100 g Potassium chloride: 50 g Sodium 2-ethyl hexyl sulphate (40% solution): 0.5 ml The chromium content was 16.2 g (312 mM). The pH of the solution was adjusted to 3.5 and heated to 50° C. A Hull cell test gave a very poor plate i.e. some metallic coating at high current densities with green and black streaking at lower current densities. Addition of 20 milligrams per liter of mono N-p-tolyl thiourea of m.w. 166, i.e. 0.12 mM, and representing the Hull cell test produced a bright uniform chromium electrodeposit having an attractive light colour. The chromium:p-tolyl-thiourea molar ratio was 1:0.00038. EXAMPLE 5 Example 4 was repeated using 20 milligrams of mono-N-allyl thiourea (m.w. 116, i.e. 0.172 mM) instead of tolyl derivative. Equivalent results were obtained. The chromium allyl thiourea molar ratio was 1:0.00055. EXAMPLE 6 A solution as given in example 4 was made up but 50 milligrams per liter of sodium diethyl dithiocarbamate of m.w. 170, i.e. 0.294 mM, were added in place of the tolyl thiourea. A Hull cell test produced a bright uniform deposit having an attractive light colour. The chromium:dithiocarbamate molar ratio was 1:0.00094. EXAMPLE 7 The following species were dissolved in water and the resulting solution diluted to 1 liter with water. chromic chloride: 5 g (i.e. 1.64 g Cr, i.e. 31.5 mM) Boric acid: 60 g Potassium chloride: 100 g Sodium sulphate: 150 g Sodium dihexyl sulpho-succinate (60% solution): 0.5 ml The pH of the solution was adjusted to 2.5 and heated to 50° C. A Hull cell test produced a very poor plate i.e. a discolouration of the brass panel was seen and not a metallic coating. Addition of 10 milligrams per liter tetraethyl thiuram disulphide of m.w. 286 i.e. 0.035 mM, and repeating the Hull cell test produced a bright uniform chromium electrodeposit of attractive colour. The chromium:thiuram disulphide molar ratio was 1:0.00111. EXAMPLE 8 A solution as given in example 6 was made up but 10 milligrams per liter of tetramethyl thiuram mono-sulphide of m.w. 208 i.e. 0.048 mM were added in place of the disulphide. A Hull cell test produced a bright uniform deposit having an attractive light colour. The chromium:thiuram sulphide molar ratio was 1:0.00152. EXAMPLE 8 Example 1 was repeated except that instead of thiourea there was used, in seven different assessments: (a) 2 g./1. (13.9 mM) sodium allyl sulphonate, giving a chromium:sodium allyl sulphonate molar ratio of 1:0.432. (b) 5 g./1 (24.4 mM) of sodium saccharin, molar ratio 1:0.758. (c) 10 mg./1. (0.0549 mM) dithiodiglycollic acid (1:0.0017) (d) 50 mg./1 (0.325 mM) o-mercaptobenzoic acid (1:0.0101) (e) 200 mg./1 (1.149 mM) sodium dithionite (1:0.0357) (f) 500 mg./1 (2.646 mM) sodium selenate (1:0.0822) (g) A mixture of 30 mg/1 (0.395 mM) of thiourea (1:0.0123) (h) and 3 g./1. (14.6 mM of sodium saccharin (1:0.453) In each case a significant improvement in plating was achieved, giving a bright uniform chromium electrodeposit with an attractive light colour. I claim: 1. An electroplating solution containing trivalent chromium ions at least some of which are uncomplexed together with a dissolved compound selected from the group consisting of:(i) compounds of the formula (X)--SO2 --(Y in which X is selected from the group consisting of (a) an aliphatic chain of less than three carbon atoms terminating in a mercapto group (b) a disulphide of the formula Y--SO2 --X--S--S--X--SO2 --y wherein X is as defined in (a) above and Y is as defined below, and (c) a single unsubstituted benzene ring, and Y is selected from the group consisting of ONa, --OH, --NH2, a--NH--link to a benzene ring and a--NH--CO--link to a benzene ring; (ii) compounds of the formula HOOC--(CH2)n --Sm --(CH2)n --COOH wherein n and m independently are integers not greater than 2; (iii) compounds of the formula: ##STR9## wherein Z is a group conferring water solubility, and (iv) a compound selected from the group consisting of sodium metabisulphite, sodium dithionite, sodium sulphide, sodium selenate, sodium selenite, sodium tellurate and sodium tellurite; said dissolved compound being present in a less than equimolar ratio in relation to the trivalent chromium ions thereby leaving at least part of the trivalent chromium ions uncomplexed by said compound. 2. A solution as claimed in claim 1 in which the relative molar concentration, of trivalent chromium to the said dissolved compound, is more than 1:0.1 respectively. 3. A solution as claimed in claim 2 in which the said ratio is more than 1:0.01 respectively. 4. A solution as claimed in claim 1, 2 or 3 which is from 0.01 to 1.0 molar in trivalent chromium. 5. A solution as claimed in claim 1, 2 or 3 containing from 1 to 500 mg/l of the said dissolved compound. 6. A solution as claimed in claim 1, 2 or 3 containing from 10 to 100 mg/l of the said dissolved compound. 7. A solution as claimed in claim 1, 2 or 3 in which the dissolved compound is a sulphur containing organic compound of the formula (X)--SO2 --(Y) in which X is selected from the group consisting of (a) saturated and unsaturated two and three-carbon atom aliphatic groups terminating in a mercapto group (b) disulphides of the formula (Y)--(SO2)--X--S--S--X--(SO2)--Y, wherein X is as defined in (a) above and Y is as defined below, and (c) a single unsubstituted benzene ring; and Y is selected from the group consisting of --ONa, --OH, and --NH2 provided that when X is a single unsubstituted benzene ring, it includes direct--NH--linkages and indirect--NH--CO--linkages to the ortho position of said ring. 8. A solution as claimed in claim 1, 2 or 3, in which the dissolved compound is selected from the group consisting of:sodium allyl sulphonate CH2 ═CH--CH2 SO3 Na, sodium vinyl sulphonate CH2 ═CH--SO3 Na, mercaptopropane sulphonic acid HS--CH2 CH2 CH2 SO3 H, bis-(sodium sulphopropyl) disulphide HO3 S--OH2 CH2 CH2 --S--S--CH2 CH2 CH2 --SO3 H, benzene sulphonamide C6 H5 SO2 NH2, thiamazole of formula: ##STR10## and saccharin of formula: ##STR11## 9. A solution as claimed in claim 1, 2 or 3 in which the dissolved compound is an organic compound of formula: HOOC--(CH.sub.2).sub.n --S.sub.m --(CH.sub.2).sub.n --COOH where n or m is 1 or 2. 10. A solution as claimed in claim 1, 2 or 3 in which the dissolved compound is dithiodiglycollic acid or thiodiglycollic acid. 11. A solution as claimed in claim 1, 2 or 3 in which the dissolved compound is selected from the group consisting of ortho-mercapto benzoic acid, ortho-mercapto phenol and ortho-mercapto sulphonic acid. 12. A solution as claimed in claim 1, 2 or 3 in which the dissolved compound is selected from the group consisting of sodium salts of metabisulphite, dithionite, sulphide, selenate, selenite, tellurate and tellurite. 13. A solution as claimed in claim 1, 2 or 3 in which the dissolved compound is organic and has a molecular weight of less than 300. 14. A solution as claimed in claim 1, 2 or 3 of pH 1.5 to 4.5. 15. A solution as claimed in claim 1, 2 or 3 of pH 2.5 to 4.0. 16. A solution as claimed in any claim 1, 2 or 3 which contains a buffering agent. 17. A solution as claimed in claim 1, 2 or 3, which contains a buffering agent selected from the group consisting of boric acid, borates, carboxylic acids and carboxylic acid salts. 18. A solution as claimed in claim 1, 2 or 3 which includes a conductivity salt at a concentration up to saturation. 19. A solution as claimed in claim 1, 2 or 3 in which a wetting and and/or an antifoaming agent is present. 20. A solution as claimed in claim 1, 2 or 3 which includes a reducing agent. 21. An electroplating process in which (a) a workpiece is immersed in an electroplating solution in accordance with claim 1, 2 or 3, and (b) electric cuurent is passed through the solution from a compatible anode to the workpiece as a cathode to produce an electrodeposited chromium plate. 22. An electroplating process as claimed in claim 21 in which the current density over the workpiece is between 1 and 100 amperes per sq. decimeter. 23. A process as claimed in claim 21 in which the temperature of the bath is maintained between 10° and 90° C. 24. A process as claimed in claim 21 wherein the pH of the bath is maintained from about 2.5 to about 4.0. 25. A process as claimed in claim 21 in which the workpiece is metal. 26. An article having on at least one surface thereof a chromium electrodeposit produced by the process in which(a) a workpiece is immersed in the electroplating solution of claim 1, and (b) electric current is passed through the solution from a compatible anode to the workpiece as a cathode to produce an electrodeposited chromium plate.

1982-02-03

en

1984-09-25

US-20629280-A

Method of making dental bridge using a prefabricated non-precious pontic ABSTRACT Disclosed is a prefabricated pontic framework formed of a non-precious material and method to be used in making dental bridges. The prefabricated pontic framework comprises a plurality of pontic supports with a connecting bar mounted on opposed sides of each pontic support, such pontic framework being selected and cut to size for a particular bridgework situation. This application is a division of application Ser. No. 042,708, filed May 25, 1979, now U.S. Pat. No. 4,269,595. FIELD OF THE INVENTION The present invention is directed to a prefabricated pontic framework formed of a non-precious material and to a method of making dental bridges using prefabricated pontic frameworks. DESCRIPTION OF THE PRIOR ART In manufacturing dental bridges, wax copings are formed by using cut down teeth impressions for dies. A plurality of pieces of wax or wax pontic supports are typically positioned between spaced apart abutment teeth, one such piece of wax corresponding to each missing tooth. The wax pontic supports and the wax copings are interconnected by small wax attachments. Next, the wax pieces are "invested" by surrounding the same in a substance that turns into a solid investment material. The wax copings and wax pontic framework are then placed in an oven wherein the wax is burned out. The formation of the wax pontic framework, regardless of the casting metal used, is a very time consuming step and adds greatly to the overall cost of producing dental bridges. After the wax is burned out in the oven, a precious metal, such as gold, is centrifugally fed into the residual mold left by the departed wax. Consequently, the wax copings and wax pontics are converted to gold copings or crowns and gold pontics, each of which are interconnected by the gold alloy. It should be appreciated that the precious alloy may include other metals, such as silver. It has been preferred by prior art practices that the crowns on the abutment teeth should be of a precious alloy so as to be sufficiently malleable and burnishable to be capable of being pushed down close to the abutment tooth surfaces. As is appreciated in the art, a non-precious alloy cannot be soldered or chemically fused with a precious alloy. Hence, the formation of the dental bridge is accomplished in one casting, with the pontics, in addition to the crowns, being formed of a precious alloy. Hence, the use of a substantial quantity of precious metal, such as gold, adds tremendously to the cost of the dentist, laboratory, and patient. After the casting, porcelain is applied to the gold pontic framework and gold copings to finalize the formation of artificial teeth. SUMMARY OF THE INVENTION The present invention is directed to a prefabricated pontic framework formed of a non-precious material and to a method of making dental bridges using prefabricated pontic frameworks. The prefabricated pontic frameworks comprises a plurality of pontic supports, with a pair of opposed sides of each pontic support having connecting bars extending therefrom. In one embodiment, the prefabricated pontic framework is formed of a non-precious alloy or precious alloy and in another embodiment the prefabricated pontic framework is formed of plastic. It should be appreciated that the framework can be supplied in other materials if desired, such as a gold alloy, or even wax. By providing prefabricated pontic frameworks to the dental laboratories, a substantial amount of time for the technician is saved in making the dental bridges, in that the prior art practice requires the pontic framework to be made of wax prior to casting. Secondly, the prefabricated pontic framework allows for the replacement of gold alloy pontic supports with the prefabricated non-precious pontic framework, thereby reducing cost to the dentist, laboratory, and patient. The use of the plastic prefabricated pontic framework allows for the pontic framework to be heated and bent to conform to a severely swayed or curved edentulous ridge, such as that encountered with making anterior bridges. Moreover, due to the strength of and rigidity of pontic framework formed of non-precious alloys, the dimensions of the pontic framework can be decreased as compared to the gold alloy pontic framework of the prior art. This, in turn, allows for increased room for porcelain, thereby providing improved esthetics in the porcelain bridgework. The proposed method of making dental bridges comprises cutting the prefabricated pontic framework to the desired length for fitting between opposed abutment dies, with the desired number of pontic supports corresponding to the missing teeth. Next, the cut pontic framework is attached to a pair of wax copings, which are shaped on the abutment dies. Subsequently, the prefabricated pontic framework, with at least one wax coping on each end thereof, is invested and cast. This method provides a dental bridge frame having either non-precious or gold copings or crowns which are mechanically bonded to the prefabricated pontic framework. Since non-precious alloys are not readily burnishable, the method allows for the use of gold alloy copings with non-precious pontic framework. Hence, the gold alloy coping is sufficiently malleable to meet the needs of conforming to the abutment teeth, whereas the pontic framework is sufficiently strong and rigid to provide structural support. At the same time, as previously explained, the use of the prefabricated pontic framework reduces gold usage and saves time for the technician by eliminating the prior art practice of "waxing up" the pontic framework. That is, making them "from scratch" is eliminated. BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of the present invention will become apparent as the following description proceeds, taken in conjunction with the accompanying drawings in which: FIG. 1 is a plan view of the initial stages of forming a dental bridge in the prior art with the illustrated elements being found in the present invention. FIG. 2 is a plan view of the initial stages of forming a dental bridge of the present invention wherein the cut prefabricated pontic framework of the present invention is illustrated. FIG. 3 illustrates the "waxing up" of the present invention. FIG. 4 illustrates the casting and "burn out" of the wax of the present invention. FIG. 5 illustrates the final dental bridge of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates the initial steps and elements in making dental bridges which are found in the prior art and which are in common with the present invention. FIGS. 2 through 5 progressively illustrate the successive steps in forming the dental bridge of the present invention, with a completed dental bridge 10 being illustrated in FIG. 5. The dental bridge 10 is used to mount one or more artificial teeth between adjoining, real abutment teeth. Referring to FIG. 1, a positive impression mold die 12, which is normally prepared from a negative impression provided from a dental office, is prepared in a conventional manner, typically in a dental laboratory. As is standard practice, the impression mold die 12 is made of hardened die stone, with a plurality of keyed pins 14 being used for anchoring the impression mold die 12 into a support base 16. Next, the prior art practice calls for cutting the impression mold die 12 to create a plurality of sections 18. Typically, there are abutment teeth sections 20 and 22, which define abutment dies 26 and 28 respectively, and a center edentulous section 24, which corresponds to the location of the missing teeth. It should be understood that the abutment dies 26 and 28 conform to the image of the real abutment teeth after they have been cut down around an end tooth area which, in turn, defines an end tooth portion 30 of the dies 26 and 28. The abutment teeth dies 26 and 28, in a conventional manner, are then "waxed-up" to produce wax coping 32, which are thin wax molds that conform to the exterior of the cut down tooth portions 30 of the abutment dies 26 and 28. The wax copings 32 are normally trimmed to terminate at a margin 33, which corresponds to the edge of the cutdown tooth portion 30 of the abutment teeth dies 26 and 28. In other words, the tooth portions 30 of abutment dies 26 and 28 form the wax copings 32. There may be more than one abutment die on each side of the dental bridge 10. Up to this point, the prior art practice and the processes of this invention are the same. The remainder of the prior art practice is described in the Background Section. The improvement of the present invention comprises replacing the precious alloy pontic framework of the prior art with a prefabricated non-precious pontics framework 38, while retaining copings or crowns for the abutment teeth formed of precious metal. Also, the copings or crowns for the abutment teeth can be cast in either precious or non-precious metal as desired by the dentist. Referring to FIG. 2, the method of the present invention continues from those steps heretofore described in relation to the prior art in a manner illustrated in FIG. 2. More specifically, before the wax copings 32 are waxed-up using conventional wax-up procedures, the prefabricated pontic framework 38 is cut to size. It is contemplated that the prefabricated pontic framework 38 will be supplied by a dental manufacturer to the dental laboratories in a form described hereinafter. The prefabricated pontic framework of the preferred embodiment 38 comprises three pontic supports 40 interconnected by a plurality of knurled connecting bars 42, one such bar 42 being disposed on opposed sides of each of the pontic supports 40. The illustrative example of FIG. 2 shows the pontic framework 38 which corresponds to a desired dental bridge for replacing one molar tooth, using molar pontic support 44, and two bicuspid teeth, using biscuspid pontics support 46 and 48. This defines a three unit posterior pontic framework 38. If less than the three pontic supports 44, 46 and 48 are required, it is contemplated that the connecting bars 42 can be transversely cut using conventional cutting methods to give the desired pontic framework 38. Consequently, the pontic framework 38 can, for example, be divided up along cut lines 50 so as to provide a pontic framework 38 cut to any length according to the patient case requirements, utilizing one, two, or all three pontic supports 40. The pontic framework 38 is ideally composed of a non-precious alloy, such as chrome cobalt, or alternatively a plastic or wax. It should be appreciated that the prefabricated pontic framework 38 can be provided with any number of pontic supports 40, although three are preferable. Moreover, the pontic framework 38 can be designed to correspond to any part of a patient's teeth. It is anticipated that at least six or seven different pontic frameworks 38 will be provided to the dental laboratories from the dental manufacturers. This range of pontic frameworks 38 will cover all or most of the possible dental bridges 10 that are normally required. It is contemplated that the pontic framework 38 will have various combinations of pontic supports 40, with there being a size range, such as large, medium, and small, depending upon the type and size of the missing tooth to which the individual pontic support 40 corresponds. Moreover, the individual pontic supports 40 can be ground to meet a desired size and configuration. Referring to FIG. 2, after the dental laboratory has selected the particular pontic framework 38 for the desired dental bridge 10, the pontic framework 38 is cut to fit an edentulous space 52, which corresponds to the space between the abutment teeth dies 26 and 28. The two connecting bars, that protrude from the ends of the pontic framework 38 and which engage the wax copings 32, are defined as the distal bar 54 and the mesial bar 56. Hence, these bars 54 and 56 are cut so that they are close to or touching the appropriate abutment dies 26 and 28. Preferably, the dimensional length of the pontic frame 38 is determined prior to the abutment dies 26 and 28 being waxed up. After the abutment dies 26 and 28 are waxed up, the tolerance therebetween normally does not permit the cut pontic arrangement 38 to be fitted therebetween. Preferably, the pontic arrangement 38 can be heated up so that the wax copings 32 will melt slightly in the areas of contact with the pontic framework 38. This permits the pontic framework 38 to be positioned in its correct location. Other procedures for positioning the pontic framework 38 will be obvious to one skilled in the art, such as trimming away a portion of the wax coping 32, instead of melting it away. Referring to FIG. 3, the next step of the process is to flow wax 58 around the connecting bars 54 and 56 so as to connect the pontic framework 38 securely to the opposed pair of wax copings 32. It should be appreciated that the connecting bars 54 and 56 allow adequate mechanical retention for the wax 58. Referring to FIG. 4, the next step, after pouring the wax 58, is to invest the entire bridge framework, which at this point comprises the pontic framework 38 with the pair of opposed wax copings 32 mounted on each end thereof by the wax 58. The entire bridge framework is removably mounted on a relatively heavy, horizontally disposed sprue 60. In that the plastic sprue 60 has a hollow tube portion 62 therein, the sprue 62 serves not only to stabilize the entire bridge framework, but it also serves as a reservoir to provide interior access for the input of the material to replace the wax. Hence, in a conventional manner the entire bridge framework is surrounded by known liquid investment material, which then hardens. Then the wax copings 32, the wax 58 and the sprue 62 are burned out in an oven, typically at 1200 degrees Fahrenheit. Subsequently, the investment material has hollow areas which previously held the wax and into which the melted alloy, such as gold or non-precious metal is centrifugally fed, in a manner well known in the art, to produce the entire bridge framework in metal. The spaces previously occupied by the wax become crowns or metal copings 32, which are mechanically attached to the pontic framework 38. It should be appreciated that as part of the prior art practice, it is well known that the coefficient of expansion of the gold and its surrounding investment material needs to be similar, so as to avoid various shrinkage problems. As with the prior art, the expansion of gold for the crowns or copings 32 is controlled. With the prefabricated pontic framework 38, there is no expansion or contraction thereof; hence, the shrinkage problem with respect to the framework 38 is virtually eliminated. As is well known in the art, soldering of precious metal to non-precious metal is not possible. However, with the above described investing and casting procedures, a mechanical bond is formed between the non-precious pontic framework 38 and the precious or non-precious crowns or pontics 32. In the preferred embodiment the wax copings 32 are replaced with a precious alloy, such as a gold alloy, for the reason that it is readily burnishable. However, a non-precious material identical to the prefabricated pontic arrangement 38 can also be used for the copings 32, depending upon the dentist's specifications. The non-precious alloys are inherently stronger and more rigid that the softer and more pliable gold alloys. Gold alloy pontics have a tendency to flex under stress, whereas those of non-precious alloy are more stable. Hence, it has proven very desirable to make the crowns out of precious alloys so that they can be burnished to fit the abutment teeth. On the other hand, it has proven to be very desirable to make the pontic framework 38 out of a non-precious alloy so as to provide structural support strength. Moreover, due to the strength of and rigidity of the non-precious pontic framework 38, the dimensions of the pontic framework 38 can be decreased as compared to those composed of a precious alloy. As will become apparent hereinafter, this, in turn, allows for increased room for porcelain, thereby improving the esthetics in the porcelain bridgework. In summary, since the non-precious alloys are not readily burnishable, the prefabricated pontic framework 38 allows for the use of gold copings or crowns 32 with non-precious pontic frameworks. This overcomes the problem of non-burnishable margins for the metal copings that would occur with a full non-precious bridge 10. At the same time, the replacing of gold alloy pontics with prefabricated non-precious pontic frameworks 38 results in a substantial cut in gold alloy usage, thereby reducing cost to the dentist, laboratory, and patient. However, the manufacturer can also supply gold alloy pontic frameworks if the dentist requires it. Referring to FIG. 5, after the above described casting step the wax copings 32 have been converted to metal copings 64 and at this point consists of an incomplete dental bridge framework 66. This dental bridge framework 66, consisting of the prefabricated framework 38 with metal copings 64 attached thereto, is then finished down following normal, well-known procedures. Porcelain 68 is then applied to the dental bridge framework 66 to give the appearance and form of real teeth. Some non-precious alloys require a porcelain bonding agent be used before application of the standardly applied opaque porcelain. In the case where a bonding agent is used and the copings 64 are of gold alloy, de-gassing of the gold alloy may be obtained while firing the bonding agent. Opaque porcelain and translucent porcelain are then applied using conventional porcelain-to-metal bridgework procedures. In an alternative embodiment of the present invention, the prefabricated pontic framework 38 can be composed of a plastic or wax material. This is particularly desirable in the case where the dental bridge 10 is being made for an edentulous ridge which is severely swayed or curved. This situation requires more extensive pontic adaption, such as with anterior dental bridges 10. A prefabricated pontic framework 38 formed of plastic or wax can be heated and curved to the desired dimensions to meet the severely curved edentulous ridge. Moreover, the plastic pontic framework 38, in turn, can then be used to cast a non-precious or precious alloy pontic framework 38. In other words, the plastic pontic framework, after being properly bent, can be burned away, with a non-precious or precious material being substituted therefor. In summary, a plastic pontic framework 38 can be desirable in an anterior bridge situation, while a non-precious alloy pontic framework can be desirable in a posterior bridge situation. Although particular embodiments of the invention have been shown and described here, there is no intention to thereby limit the invention to the details of such embodiments. On the contrary, the intention is to cover all modifications, alternatives, embodiments, usages and equivalents of the subject invention as fall within the spirit and scope of the invention, specification and the appended claims. What is claimed is: 1. A method of making dental bridges wherein at least a pair of opposed wax copings, formed by at least a pair of opposed abutment dies, are subsequently invested and cast into precious alloy copings, the improvement comprising the steps of:providing a prefabricated pontic framework of non-precious metal having at least one pontic support with a pair of connecting bars extending therefrom; cutting the connecting bars to a desired length to fit between the abutment dies of said pair of opposed abutment dies; attaching one of the connecting bars to each of the wax copings of said pair of opposed wax copings; investing the pair of opposed wax copings with the prefabricated pontic framework disposed therebetween. 2. In the method of claim 1,providing a prefabricated pontic framework formed of a non-precious alloy. 3. In the method of claim 1,providing a plurality of pontic supports rigidly connected to each other with the connecting bars; providing the prefabricated pontic framework with a pair of connecting bars extending from each end of the prefabricated pontic framework; cutting the prefabricated pontic framework across one of connecting bars to obtain the desired number of pontic supports of the desired size. 4. In the method of claim 1,mounting the pair of opposed copings, having the prefabricated pontic framework therebetween, on a prong-like sprue; casting the pair of opposed wax coping and union to the framework in a precious alloy.

1980-11-05

en

1982-08-31

US-74447096-A

Book holder ABSTRACT A book holder for holding and positioning books and documents. The book holder includes a document support and display surface with oppositely disposed (page) engagement clips extending from the support surface. An adjustable line guide is removably positioned on the support surface for selective vertical transgression thereover. An extensible document engagement clip extends from the top of the display surface. BACKGROUND OF THE INVENTION 1. Technical Field This invention relates to book and copy holders used for positioning materials so that they can be viewed by a user while performing other tasks. A book holder generally supports a book on an incline flat surface with a holding means. 2. Description of Prior Art Book and copy holders of this type have relied on a variety of useful constructions for supporting a book or papers in an upstanding position so that it can be easily read without holding same. Typically, a user would use both hands to support a book in an angled upright open position. This precludes or makes difficult for the user the use of their hands for writing or other like tasks. Alternately, books, if hardback for example, can be propped up by leaning on some article and other non-rigid publication require more support such a workbooks used by teachers and students that are difficult to hold open and upright required for use. A number of different book and page holders have accordingly been developed to solve this problem. Prior art holders of this type have a support frame or surface with attachment straps, hooks or clamps to hold the book on the stand and open or a single page to be copied, for instance. Examples of such devices can be seen in U.S. Pat. Nos. 1,899,404, 2,156,225, 2,441,932, 4,416,414, 4,712,760 and 5,052,650. In U.S. Pat. No. 1,899,404 a book holder and table can be seen having a book support platform pivotally secured to an adjustable frame stand with a center engagement clip and a pair of adjustable leaf retainers. U.S. Pat. No. 2,156,225 is directed to a reading stand having a wire support construction, a book engagement plate and multiple pivoted spring clips to hold the book open positioned within. U.S. Pat. No. 2,441,932 shows an easel type support having a pair of criss-cross collapsible X-shaped support frame elements pivotally secured together with a resistance chain therebetween on an easel support. Page clips are removably secured to a central cross frame member. Referring to U.S. Pat. No. 4,116,414, a book holder can be seen having a support sheet with a pivot stand leg. A pair of clothes pins are resiliently secured to the support sheet engageable on a book position thereon. U.S. Pat. No. 4,712,760 discloses a back rest with a page retainer having a tapered base with an insertable upstanding wall extending therefrom. Page retaining clips are adjustably positioned from the back for engagement thereover. In U.S. Pat. No. 5,052,650 illustrates a copy holder having an upright flat surface supported by an adjustable stand with a line guide extending inwardly across the engagement surface from one side. SUMMARY OF THE INVENTION A book holder of the present invention for supporting and displaying books, magazines and papers in an upright angled attitude. The book holder includes an elongated angled base with an integral upstanding support surface extending at right angles thereto. An angular leg support extends from the support surface which has a movable line guide extending thereacross. A pair of oppositely disposed retaining clips extend from the support surface for bi-lateral book engagement. A top page retainer means is included to maintain page typed documents on the support surface. DESCRIPTION OF THE DRAWINGS FIG. 1 a perspective view of the book holder with page retainers shown therein; FIG. 2 is a rear elevational view of the book holder set forth in FIG. 1; FIG. 3 is an enlarged front elevational view of a page guide receiving slot and associated end rails; FIG. 4 is a side elevational view on lines 4--4 of FIG. 3; FIG. 5 an enlarged partial side elevational view of a page line guide assembly within the support surface; and FIG. 6 is an enlarged side elevational view of a page engagement means with portions broken away; and FIG. 7 is an enlarged top plan view of a portion of the page line guide illustrated in FIG. 5. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2 of the drawings, a book holder 10 of the invention can be seen having an inclined elongated base 11 and a support surface 12 extending therefrom. The base 11 has a front surface 13 from which are formed a pair of oppositely disposed legs 14 and 15. An inclined upper surface 16 of the base 11 extends from the front surface 13 with interconnected sidewall surfaces 17 and 18. The support surface 12 extends intrinsically from the upper surface 16 opposite said front surface 13 at a right angle thereto imparting an angled inclination to the support surface 12. The support surface 12 is generally flat having a top edge 19 and respective side edges 20 and 21. The aforedescribed integral support surface 12 is in turn supported by a pair of brackets 22 and 23 extending from the intersection of the support surface 12 and base 11 adjacent the respective top and side edges 19 and 20 and 19 and 21. The brackets 22 and 23 have respective curved base legs 22A and with integral angles braces 22B and 23B extending therefrom to the hereinbefore described support surface 12 junction of the top edge 19 and side edges 20 and 21 thereof defining a triangular area therebetween. The support surface 12 has a pair of oppositely disposed elongated parallel slots 24 and 25 inwardly of the respective side edges 20 and 21. The slots 24 and 25 extend from the upper surface 16 of the base 11 terminating in respective annular openings 24A and 25A adjacent the top edge 19. Each of the slots 24 and 25 have pairs of upstanding parallel guide rails 26 and 27 that extend therealong from the annular openings 24A and 25A to the upper surface 16 of the base 11, best seen in FIGS. 1, 3 and 4 of the drawings. Referring now to FIGS. 1 and 5 of the drawings, a line guide assembly 28 can be seen having a transparent line band 29 with engagement fittings extending therefrom for registration within the respective slots 24 and 25. Each of the engagement fittings have a pin 30 with a retaining disk 31 on its respective free end. Resilient guide leaves 32, best seen in FIG. 5 of the drawings are secured to the transparent band 29 so as to be engageable on the support surface 12 on either side of the hereinbefore described outer rails 26 and extend transversely beyond the transparent band 29 thereby defining a uniform travel path for the transparent band 29 on the rail pairs 26 and 27. It will be evident from the above description that the disks 31 are insertable through the annular openings 24A and 25A and are engageable on the support surface 12's back surface 33 overlying the slots 24 and 25. Referring back to FIGS. 1 and 2 of the drawings, page and leaf retaining clips 34 and 35 can be seen having a pair of identical elongated hooks extending from multiple horizontally aligned and longitudinally spaced mounting brackets 37 on the back surface 33 of the support surface 12. Each of the mounting brackets 37 are generally rectangular with parallel transversely extending openings 38 and 39 therethrough that are aligned with openings and adjacent brackets 37 to form respective parallel guide channels there between best seen in FIG. 2 of the drawings. The The retaining clips 34 and 35 have a cross-sectionally rectangular elongated guide channel engagement portion 34A and 35A respectively with a compound curved end portion that returns upon itself to define a resilient engagement area therebetween at 40 as will be understood by those skilled in the art. The guide channel engagement portions of the retaining clips 34 and 35 are registerable within said respective guide openings 38 and 39 from opposing side edges 20 and 21 so as to selectively overlie the support surface 12 or alternately be adjustably positioned therebeyond for engagement of a book (not shown) positioned on or extending beyond the support surface 12. A page retaining clip 41, best seen in FIGS. 1, 2, and 6 of the drawings, extends from the back surface 33 of the support surface 12 beyond the top edge 19. The retaining clip 41 has an elongated cross-sectionally rectangular main body member 42 with an end return portion 43 and a paper engagement spacing lug 44 in vertical spaced relation therebelow. An enclosed support channel 45 is formed on the back surface 33 of the support surface 12 midway between the respective side edges 20 and 21. The page retaining clip 41 is registerably received within the support channel 45 and is adjustably deployed therefrom above the top edge 19, as required. It will be apparent to those skilled in the art that the end return portion 43 of the retaining clip 41 is configured with engagement retaining convexed areas CA frictionally engaged within said enclosed support channel 45. In use, the book holder 10 of the invention can receive and hold open a book (not shown) on its angled support surface 12 resting on the base 11 with the respective retaining clips 34 and 35 horizontally adjustable within the respective guide openings 38 and 39 so as to be engageable over the respective portions of the book (not shown) as will be well understood by those skilled in the art. In use, for a single sheet or a page (P) the same is positioned on the support surface 12 and the line guide assembly 28 is positioned thereover with the page retaining clip 41 engageable on the free end of the page P as illustrated in FIG. 6 of the drawings. Referring now to FIG. 2 of the drawings, a pair of retaining clips 47 extend from the back surface 33 of the support surface 12 on oppositely disposed sides of the enclosed supporting channel 45 for registration storage of the respective page retaining clips 34 and 35 shown in broken lines as will be well understood by those skilled in the art. Thus it will be seen that a new and useful book holder has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention. Therefore I claim: 1. A book holder for supporting books and papers comprising; a base, having a front surface, interconnected side surfaces, and an upper surface, a document support surface extending from said upper surface, a bracket structure extending from said document support surface, said bracket structure including base legs with braces extending therefrom engaging said support surface in spaced vertical relation to said base legs, a pair of spaced parallel slots in said document support surface, a line guide registerable within and extending between said slots, means for spacing said line guide from said support surface, page engagement clips extending from said support surface, means for selective extension of said engagement clips on said document support surface, said page engagement clips having resilient end portions, a page retaining clip mounted on said support surface. 2. The book holder as set forth in claim 1 wherein said upper surface of said base is angularly inclined from said front surface to said document support surface. 3. The book holder as set forth in claim 1 wherein said document support surface is generally flat and is in a leaning attitude away from said front surface of said base and at right angles to said upper surface of said base. 4. The book holder as set forth in claim 1 wherein said bracket structure defines a triangular area between the leg and brace and support surface. 5. The book holder as set forth in claim 1 wherein said means for spacing said line guide from said support surface comprises: pairs of rails on said support surface adjacent said parallel slots. 6. The book holder set forth in claim 1 wherein said page engagement clips are cross-sectionally rectangular having compound curved end portions defining a resilient engagement portion therebetween. 7. The book holder of claim 1 wherein said means for selective extension of said engagement clips from said support surface comprises: a plurality of mounting brackets on a back surface of said support surface, said mounting brackets defining a pair of segmented guide channels therebetween. 8. The book holder as set forth in claim 1 wherein said page retaining clip comprises: an elongated body member, an end return of said body member, a lug in said body member adjacent said return, a mounting support channel on said document support surface. 9. The book holder of claim 1 wherein said line guide comprises: a guide band, oppositely disposed retaining assemblies extending therefrom, said retaining assemblies registerable through said respective slots in said support surface. 10. The book holder of claim 9 wherein said retaining assembly comprises: a pin extending from said guide band, a retaining disk on the end of said pin, a guide leaf extending from said guide band, said retaining disk registerable through apertures in said support surface interconnected with said slots.

1996-11-07

en

1999-01-05

US-79797885-A

Portable wind-resistant sign stand with flexible sign ABSTRACT A preferred lightweight, portable sign and stand apparatus generally includes a plurality of ground-engaging legs secured to a longitudinally-extending elongated base assembly. The base assembly of the preferred apparatus includes clamping members for clampingly anchoring a thin, flat sign panel protruding generally upwardly therefrom. The sheet material of which the sign panel is composed is sufficiently rigid that the sign panel is self-supporting in its protruding relationship with the base assembly. The sign panel is sufficiently flexible and resilient, however, to bendably deflect in a generally lateral direction, without yielding, in response to transverse loads exerted thereon, thereby substantially preventing the sign and stand apparatus from tipping over. The sign and stand apparatus also preferably has a resultant or combined center of gravity that remains inboard of the engagement of the legs with the ground in order to further resist any tendency to tip over in high winds. BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to sign and poster display devices of all kinds. The invention more particularly relates to portable sign and stand apparatus having a wind-resistant, flexible sign panel. Numerous sign stands and poster display devices known today are used for displaying various signs and messages for conveying advertisements and information to the public. In many of such sign and stand apparatuses, the signs are typically positioned on sign standards or posts that are anchored in the ground, held in place by sandbags or other heavy objects, or spring-mounted on bases which allow them bend or deflect without tipping over under high wind forces. Spring-mounted sign stands which can be used for this purpose are shown in U.S. Pat. Nos. 3,646,696; 3,662,482; 4,033,536; 4,265,040; and 4,288,053; as well as in copending patent applications, Ser. Nos. 274,400, filed June 17, 1981; 442,378, filed Nov. 17, 1982; 442,418, filed Nov. 17, 1982; and 442,419, filed Nov. 17, 1982. All of said copending applications are assigned to the same assignee as the invention herein, and their disclosures are hereby incorporated by reference herein. Such deflectable sign stands, although unanchored and lightweight, prevent tipping over or sliding of the sign and stand units in virtually all weather and wind conditions. Although the above-described sign and sign stand units are well-adapted for a variety of sign or display applications, it is an object of the present invention to provide a portable and wind-resistant sign and stand apparatus that is even lighter in weight than the previous sign and stand units and which employs a minimum number of parts or components. A further object is to provide a sign and stand apparatus that has a unique and attractive appearance, is inexpensive to manufacture, and which may be used in many different applications, including point-of-purchase displays, pedestrian or vehicular traffic messages or barriers, commercial advertisements, etc. In accordance with the present invention, an improved wind-resistant sign and stand apparatus generally includes an elongated base assembly, a plurality of ground-engaging legs extending transversely from and secured to, the elongated base assembly, and a one-piece monolithic sign panel protruding in a generally vertical direction from the base assembly. The sign panel, which is preferably composed of a thin, flexible sheet-like material, has a lower peripheral portion clamped to the base assembly and is sufficiently rigid that the remainder of the sign panel is self-supporting in its vertically protruding relationship with the base assembly. The sign panel is sufficiently flexible and resilient, however, to deflect without yielding in response to loads exerted thereon, such as high wind forces, for example. In a preferred embodiment of the invention, the sign panel is clamped to the base assembly and maintained in an elevated position such that its lower end is generally adjacent to the ground, but slightly spaced therefrom in order to minimize the amount of air that can pass under the sign panel in high winds, thereby substantially avoiding or minimizing the creation of .[.a.]. .Iadd.aerodynamic forces .Iaddend.low pressure region on the downwind side of the side panel. The sign and stand apparatus also preferably has a resultant or combined center of gravity that remains between the ground-engaging ends of the legs regardless of whether the sign panel is deflected or vertically disposed, thereby substantially preventing the sign and stand apparatus from tipping over in high winds. Additional objects, advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sign and stand apparatus in accordance with one embodiment of the present invention. FIG. 2 is an elevational view, looking in the direction of the arrow 2 of FIG. 1. FIG. 3 is a cross-sectional view, taken along 3--3 of FIG. 2. FIG. 4 is a partial side elevational view of the sign panel and base assembly of the sign and stand apparatus of FIG. 1, with the sign panel illustrated in a vertical, undeflected position. FIG. 5 is a view similar to that of FIG. 4, but with the sign panel illustrated in a deflected position. FIG. 6 is a partial bottom view of the sign and stand apparatus, looking in the direction of the arrow 6 of FIG. 4. FIG. 7 is a full side view of the sign and stand apparatus with the sign deflected. FIGS. 8 and 9 show two alternate embodiments of the sign for use with the present invention. FIG. 10 illustrates still another embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 through 7 illustrate an exemplary embodiment of a wind-resistant sign and stand apparatus in accordance with the present invention. One skilled in the art will readily recognize from the following discussion that the principles of the present invention are equally applicable to sign and stand units other than that shown for purposes of illustration in the drawings. As shown in FIG. 1, an exemplary sign and stand apparatus 10 generally includes an elongated base assembly 12, a plurality of ground-engaging legs 14 and 16 extending transversely therefrom, and a relatively thin and generally flat sign panel 20 with a preselected display message on one or both sides thereof. The ground-engaging legs 14 and 16 preferably extend in a generally horizontal lateral direction relative to the longitudinally-extending base assembly 12, and are preferably adapted to maintain the base assembly 12 and the lower edge 21 of the sign panel 20 in a slightly elevated position, generally adjacent to, but spaced from, the ground or other supporting surface 18. Such slightly elevated positioning of the base assembly and sign panel serves to keep the free outer ends of the legs 14 and 16 in contact with the ground on uneven surfaces in order to maintain a wide base of support for the sign and stand assembly and thereby minimize its tendency to tip over. As is discussed in more detail below, however, the base assembly and the sign panel should be positioned as close to the ground as practicable in order to minimize the amount of wind that can pass below the sign panel. Optionally, the legs 14 and 16 may be equipped with caps or pods 22, which if used are preferably composed of rubber or other non-skid material to help prevent the sign and stand apparatus from sliding on smooth or hard supporting surfaces. It is understood that the base assembly and legs can have any shape and cross-sectional configuration, so long as the points of contact of the base on the ground 18 generally form a perimeter shape and the center of gravity of the sign stand stays within it (as explained infra). The legs and base can also be foldable for ease of transportation and storage of the sign stand. As is further illustrated in FIGS. 2 through 7, the base assembly 12 preferably includes a pair of elongated, generally longitudinally-extending clamping members 24 and 26, which clampingly secure and anchor a lower peripheral end portion 28 of the sign panel 20 therebetween. At least the clamping member 24 is preferably a hollow elongated member having a generally rectangular lateral cross-section, and is secured at opposite longitudinal ends to a pair of bracket members 30 and 32. In the preferred embodiment, the clamping member 26 is also secured at opposite longitudinal ends to the bracket members 30 and 32, but the clamping member 26 is preferably an elongated angle member having a generally L-shaped lateral cross-section. The preferred bracket members 30 and 32 generally include respective channel-shaped portion 34 and 36 adapted to receive the respective ground-engaging legs 14 and 16 therein, and respective horizontal plate portions 38 and 40, to which the preferred clamping members 24 and 26 are secured. As shown in the drawings, the members are secured together by a plurality of bolts 33, although it is understood that any other types of fasteners or securing means known to those skilled in the art can also be used. When secured to the bracket members 30 and 32, either or both of the clamping members 24 and 26 function to resist torsional loads exerted thereon as the sign panel 20 deflects under high wind loads as is described below. The clamping members 24 and 26 include respective clamping faces 44 and 46 which clampingly engage the generally vertical opposite surfaces of the lower peripheral portion 28 of the sign panel in a substantially flat relationship therewith. Preferably, the clamping faces 44 and 46 engage the entire longitudinal width of the lower peripheral portion 28 in order to uniformly distribute the clamping forces thereon and thus minimize stress concentrations. The clamping members 24 and 26 are preferably forcibly urged toward one another to clampingly engage and anchor the sign panel therebetween by means of a plurality of threaded fasteners 50 spaced longitudinally along the base assembly 12. The fasteners 50 preferably extend through corresponding apertures in the clamping members 24 and 26 and in the lower peripheral portion 28 of the sign panel. As an alternative embodiment, the clamping faces 44 and 46 may be sufficiently large to allow for adequate clamping of the sign panel therebetween without having the fasteners 50 extend through the sign panel. In such an embodiment, the fasteners would not have to be removed, but rather would only need to be loosened in order to remove or insert the sign panel between the clamping members. As still another embodiment, if a permanent installation is desired, rivets or other permanent fasteners extending through the clamping members and sign panel may be employed. It should be noted that as an alternate embodiment to that described above, only one of the clamping members 24 and 26 is required to be secured to the bracket members 30 and 32. In such an embodiment the other clamping member would not be secured to the bracket members and would serve as a backing plate to uniformly distribute the clamping forces along the lower portion 28 of the sign panel 20. Furthermore, whether or not the clamping member 26 is secured to the bracket members 30 and 32, it too may optionally be a hollow member with a generally rectangular cross-section. The sign panel 20 is preferably composed of a thin sheet material sufficiently rigid that the sign panel is self-supporting in its generally vertical upwardly protruding relationship with the base assembly 12. In order to properly function as a wind-resistant sign, however, the sign panel must be sufficiently flexible and resilient to bendably deflect in a generally lateral direction, without surpassing its yield point, under the influence of predetermined loads, such as high wind forces up to 70 m.p.h., exerted transversely thereon. A preferred lightweight sheet material for the sign panel 20 is an acrylic resin, or other plastic material, either of which may also be reinforced with fiberglass. An example of one examplary material for the sign panel 20 is "Lumasite" manufactured by Amercian Acrylic Corp. of West Babylon, N.Y. Lumasite is an acrylic sheet of material, cast from methyl methacrylate (acrylic) monomer, reinforced with fiberglass. One skilled in the art will readily recognize that other flexible and resilient materials with similar characteristics and properties may be substituted for the sign panel. In addition to being strong but light in weight, the acrylic material also offers the advantage of being somewhat absorbent so that the ink used to print a message on the display surfaces of the sign panel is not easily scratched or worn off. Such material is only an exemplary, preferred material, however, and one skilled in the art will readily recognize that other synthetic or nonsynthetic materials may alternatively be employed. As still another example of an alternate material, a sheet metal sign panel composed of high-strength, tempered spring steel may be used. Such spring steel typically has a yield strength of approximately 50,000 p.s.i. Although a flat generally rectangular sign panel 20 is shown in the drawings, for purposes of illustration, the sign panel may also be embossed or non-uniform in thickness, and may have any of an infinite number of lateral profile shapes, so long as the above-discussed rigidity and flexibility are present. The sign and stand apparatus 10 has a relatively low resultant or combined center of gravity 58, largely because of the lightweight upwardly-protruding sign panel and the low location of the base assembly and legs. The relationship of the combined center of gravity 58 and the length of the generally laterally-extending legs is selected in order to prevent the sign and stand apparatus from tipping over in high winds. In order to achieve this result, the combined or resultant center of gravity 58 is preferably located at a position on the sign panel 20 that is a predetermined vertical distance from the ground 18 such that even when the sign panel deflects, the resultant center of gravity 58 remains between or within boundaries 60 defined by the location of the ground-engaging free ends of the legs 14 and 16 and illustrated in phantom lines in FIG. 1. It should be noted that the resultant center of gravity 58 may shift or change somewhat as the sign panel deflects because during the course of such deflection, more of the mass of the sign panel 20 is located closer to the ground. However, by maintaining the resultant center of gravity 58 within the confines of the base of support provided by the engagement of the legs 14 and 16 with the ground, the tendency of the sign and stand assembly to tip over under the influence of wind forces or other loads exerted transversely on the sign panel 10 is reduced or eliminated. When the sign panel deflects under strong wind forces, additional resultant forces are generated in a vertically downward direction on the feet or the ends of the legs of the base assembly. This helps to effectively anchor the sign stands in high wind forces. Furthermore, as mentioned above, the base assembly 12 and the lower edge of the sign panel 20 should be maintained at a slightly elevated position in order to maintain only the free ends of the legs 14 and 16 in engagement with the ground, even when the sign and stand assembly is placed on uneven ground or other supporting surface. This subsstantially ensures that the base of support, as defined by the boundary lines 60, is as broad as possible in order to maximize the resistance of the sign and stand apparatus to tipping in high winds. Subject to the above considerations, however, the lower edge of the base assembly 12 and the sign panel 20 should be located generally adjacent and as close as practicable to the ground in order to minimize the amount of wind that can pass beneath the sign and stand apparatus. The amount of wind allowed to pass beneath the sign must be minimized in order to prevent the sign when deflected from becoming an airfoil. As shown in FIG. 7, the sign takes an arcuate .Iadd.airfoil .Iaddend.shape when it is deflected in high winds. Thus, the air 66 passing over the top surface of the sign accelerates in velocity creating a low pressure area. This is commonly known as lift and, if large amounts of air 64 are allowed to also pass beneath the sign, the deflected sign 20 would act the same as an airfoil. If such .[.lift.]. .Iadd.high aerodynamic forces .Iaddend.were created on the sign 20, it would allow the sign stand to .[.become "lighter" and.]. be actually displaced or turned over by the wind. Therefore, by reducing the open area beneath the sign panel, the amount of wind passing therethrough is reduced. This reduces the size and intensity of the wind forces acting on the underneath side of the sign panel and thus prevents the formation of the undesirable .[."lift".]. .Iadd.aerodynamic .Iaddend.forces. For optimum results, it is preferred that the open area beneath the sign panel be 10% or less in size relative to the size of the sign panel. This has been found to be best for operation of the sign stand in high winds. FIGS. 8 through 10 illustrate a significant feature of the invention, namely that the sign 20 can have a wide variety of sizes and shapes. The sign can be made in the shape of the product that it is advertising and promoting. FIG. 8 illustrates the sign 20 formed in the shape of a pack of cigarettes; the perspective view is painted or printed on the sign and adds to the realism of the product. In addition, the same advertisement can be printed or contained on both sides, with one being the mirror image of the other. FIG. 10 illustrates a sign 20 formed in the shape of a bottle of a popular soft drink. The sign has a large area in order to make a significant impression on consumers, yet the large area is sufficient to cause the sign stand to be affected by highwind forces. FIG. 9 shows a sign which is formed in the shape of a person who has been presented in advertising as the spokesperson or symbol for a company. As can be seen, the sign 20 can take virtually any shape which creates an opportunity for significant flexibility and creativity in the marketplace. FIG. 10 also illustrates a sign stand 80 which has a base assembly 82 having foldable legs 84, 86, 88 and a fourth-foldable leg that is behind the sign panel and thus hidden from view. The legs are pivoted around pivot pins 92 and locked in place by spring pins 94 which are adapted to mate with holes 96. When the signs are used for display, the legs are folded downwardly and extend in the manner shown in FIG. 10. When the signs are being transported or stored, the legs are folded into their vertical upright positions, as shown for example by the phantom lines 84' and 86'. The present invention also has applicability to many outdoor sign and warning devices, such as traffic flow barricades used in the construction field and point-of-purchasing advertising sign stands. In any of these applications, the devices are unanchored, lightweight and portable, and yet can withstand virtually all types of wind forces. In addition to the various alternate embodiments of the invention described above, the sign panel 20 may also optionally include a hand hole 80, as shown in FIG. 1, for ease and convenience of carry. When the sign panel 20 is removed from the base assembly 12, the inventive sign stand system presents a flat, easily storable and transportable package. Additional hand holes on the side edges of the sign (not shown) could also be provided to facilitate disassembly and transport of the sign stand. The foregoing discussion discloses and describes exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion that various changes, modifications and variations my be made therein without departing from the spirit and scope of the invention as defined in the following claims. What is claimed is: 1. A lightweight and readily portable sign and stand apparatus, comprising an elongated base assembly, a plurality of ground-engaging legs extending transversely from and secured to said elongated base assembly, a one-piece monolithic sign panel having a lower peripheral portion and protruding in a generally vertical direction from said elongated base assembly and having at least one generally planar display surface thereon, said base assembly including clamping means for clampingly securing and anchoring substantially the entire length of the lower peripheral portion of said sign panel to said elongated base assembly in a generally fixed relationship therewith, said sign panel being sufficiently rigid to be self-supporting in said generally vertically protruding relationship with said base assembly but sufficiently flexible and resilient to bendably deflect without yielding in response to predetermined loads exerted thereon in directions transverse to the plane of said display surface, said sign and stand apparatus having a combined center of gravity located a predetermined vertical distance above the ground, said legs being configured to engage the ground at a predetermined horizontal distance from said base assembly, said combined center of gravity remaining horizontally within the confines of the area defined by the locations at which said legs engage the ground during said bendable deflection of said sign panel in order to substantially prevent said sign and stand apparatus from tipping over in response to said predetermined transverse loads, said sign panel, when deflected, having a continuously curved portion defining an airfoil .Iadd.shape.Iaddend., said sign panel having the lower peripheral portion disposed a preselected height above the ground to define an open area generally beneath said sign panel, the size of said open area in relation to the size of said sign panel and .[.the shape of.]. said airfoil .Iadd.shape .Iaddend.cooperating to substantially negate aerodynamic .[.lift.]. .Iadd.forces.Iaddend.. 2. A sign and stand apparatus according to claim 1, wherein said clamping means includes a pair of elongated clamping members adapted to clampingly engage said lower peripheral portion of said sign panel therebetween. 3. A sign and stand apparatus according to claim 2 wherein said elongated clamping members are adapted to clampingly engage said lower peripheral portion of said sign panel along substantially the entire longitudinal length thereof. 4. A sign and stand apparatus according to claim 3, wherein at least one of said elongated clamping members is adapted to resist torsional loads thereon in response to loads exerted on said sign panel in said directions transverse to the plane of said display surface. 5. A sign and stand apparatus according to claim 1, wherein said legs are elongated members having free outer end portions engaging the ground and opposite end portions secured to said base assembly, said free outer ends being the only portions of said sign and stand apparatus engaging the ground. 6. A sign and stand apparatus according to claim 1, wherein said sign panel has a lower edge generally parallel to the ground, said clamping means being adapted to clampingly engage said sign panel generally along said lower edge, said lower edge further being supported by said base assembly in an elevated position generally adjacent to but spaced slightly from the ground. 7. A sign and stand apparatus according to claim 1, wherein clamping means includes a pair of clamping members, each of said clamping members includes a clamping face thereon adapted for a generally flat clamping engagement with one of the opposite surfaces of said sign panel, a number of longitudinally-spaced fasteners extending in a generally lateral direction through said clamping members and said lower peripheral portion of said sign panel, said fasteners being adapted to forcibly maintain said clamping members in said flat clamping engagement with said opposite surfaces of said sign panel, one of said clamping members being secured to the remainder of said base assembly, and the other of said clamping members being detached from said remainder of said base assembly, said one secured clamping member tending to resist torsional loads exerted thereon in response to loads exerted on said sign panel in said directions transverse to the plane of said display surface. 8. A sign and stand apparatus according to claim 1 wherein said open area is ten percent (10%) of or smaller than the surface area of said sign panel. 9. A lightweight and readily portable sign and stand apparatus, comprising an elongated base assembly extending in a longitudinal direction, at least two pairs of elongated ground-engaging legs secured to said base assembly with each pair of legs laterally protruding a predetermined distance in generally opposite lateral directions from said base assembly and engaging the ground at their free outer ends, a generally planar one-piece monolithic sign panel protruding in a generally vertical direction with a lower peripheral portion thereof secured to said base assembly in a generally fixed relationship therewith, said base assembly including a pair of longitudinally-extending clamping members clampingly engaging opposite surfaces of said sign panel therebetween along substantially all of the longitudinal length of said lower peripheral portion in order to anchor and generally fix said sign panel to said base assembly, said sign panel being sufficiently rigid to be self-supporting in order to maintain itself in said generally vertical protruding relationship with said base assembly but sufficiently flexible and resilient to deflect without yielding in a generally lateral direction relative to said elongated base assembly in response to predetermined loads exerted transversely on said sign panel, said sign and stand apparatus having a predetermined combined center of gravity that remains laterally within the confines of a lateral area defined by the locations at which said legs engage the ground regardless of said deflection of said sign panel in response to said predetermined transverse loads exerted on said sign panel, said sign and stand apparatus thereby being substantially prevented from tipping over as said sign panel deflects under the influence of wind forces exerted on said sign panel, said sign panel, when deflected, having a continuously curved portion defining an airfoil .Iadd.shape.Iaddend., said sign panel having said lower peripheral portion disposed a preselected height above the ground to define an open area generally beneath said sign panel, the size of said open area in relation to the size of said sign panel and .[.the shape of.]. said airfoil .Iadd.shape .Iaddend.cooperating to substantially negate aerodynamic .[.lift.]. .Iadd.forces.Iaddend.. 10. A sign and stand apparatus, according to claim 9, wherein said sign panel is sufficiently resilient to return to its generally vertically protruding position after said deflection when said transverse loads are removed therefrom. 11. A sign and stand apparatus according to claim 9, wherein said clamping members include generally vertically extending faces thereon, said faces engaging said opposite faces of said sign panel in a substantially flat relationship therewith when said sign panel is clampingly anchored therebetween. 12. A sign and stand apparatus according to claim 9, wherein said pairs of legs are longitudinally spaced from one another. 13. A sign and stand apparatus according to claim 12, wherein one of said pairs of legs is located generally at each end of said elongated base assembly. 14. A sign and stand apparatus according to claim 9, wherein said sign panel is composed of a reinforced acrylic resin material. 15. A sign and stand apparatus according to claim 9, wherein said sign panel is composed of high-strength tempered spring steel. 16. A sign and stand apparatus according to claim 9, wherein at least one of said longitudinally-extending clamping members comprises a generally hollow member having a generally rectangular lateral cross-section. 17. A sign and stand apparatus according to claim 16, where the other of said longitudinally-extending clamping members has a generally L-shaped lateral cross-section. 18. A sign and stand apparatus according to claim 17, wherein each of said clamping members includes a clamping face thereon adapted for a generally flat clamping engagement with one of said opposite surfaces of said sign panel, a number of longitudinally-spaced fasteners extending in a generally lateral direction through said clamping members and said lower peripheral portion of said sign panel, said fasteners being adapted to forcibly maintain said clamping members in said flat clamping engagement with said opposite surfaces of said sign panel. 19. A sign and stand apparatus according to claim 9, wherein one of said clamping members is secured to the remainder of said base assembly, and the other of said clamping members being detached from said remainder of said base assembly. 20. A sign and stand apparatus according to claim 19, wherein each of said clamping members includes a clamping face thereon adapted for a generally flat clamping engagement with one of the opposite surfaces of said sign panel, a number of longitudinally-spaced fasteners extending in a generally lateral direction through said clamping members and said lower peripheral portion of said sign panel, said fasteners being adapted to forcibly maintain said clamping members in said flat clamping engagement with said opposite surfaces of said sign panel, said one secured clamping member tending to resist torsional loads exerted thereon in response to loads exerted transversely on said sign panel. 21. A sign and stand apparatus, comprising:a base assembly including a pair of generally longitudinally-extending clamping members having opposed laterally-facing and generally vertically-extending clamping faces thereon, means for selectively and forcibly urging said clamping faces toward one another, a pair of legs extending in opposite generally lateral directions and being secured to at least one of said clamping members at each opposite end thereof, each of said legs being adapted for engaging the ground at a free outer end thereof; a one-piece monolithic sign panel composed of a sheet material, said sign panel having substantially the entire length of a lower end portion adapted to be received between said clamping faces and to be clampingly engaged thereby in a generally flat mutual engagement therewith in order to secure said sign panel to said base assembly in a generally fixed relationship therewith, said lower end portion being at an elevated position relatively closely adjacent to but spaced from the ground when secured to said base assembly, said sheet material being sufficiently resilient and flexible to resiliently deform in a generally lateral direction without yielding in response to predetermined forces exerted transversely thereon, said sheet material further being sufficiently rigid to be self-supporting in a generally vertically protruding relationship with said clamping members; and said sign and stand apparatus having a combined resultant center of gravity located at a predetermined vertical position such that as said sign panel deflects said center of gravity remains laterally between the lateral confines of said ground-engaging ends of said legs, thereby substantially preventing said sign and stand apparatus from tipping over in response to wind loads exerted thereon, said sign panel, when deflected, having a continuously curved portion defining an airfoil .Iadd.shape.Iaddend., said sign panel having a lower peripheral portion disposed a preselected height above the ground to define an open area generally beneath said sign panel, the size of said open area in relation to the size of said sign panel and .[.the shape of.]. said airfoil .Iadd.shape .Iaddend.cooperating to substantially negate aerodynamic .[.lift.]. .Iadd.forces.Iaddend.. 22. A sign and stand apparatus according to claim 21, wherein said means for forcibly urging said clamping faces toward one another comprises a plurality of longitudinally-spaced threaded fasteners extending laterally through corresponding longitudinally-spaced apertures in said clamping members and in said lower end portion of said sign panel. 23. A sign and stand apparatus according to claim 22, wherein said sheet material is composed of fiberglass-reinforced acrylic resin. 24. A sign and stand apparatus according to claim 22, wherein said sheet material is composed of high-strength tempered spring steel. 25. A sign and stand apparatus according to claim 21, wherein said clamping member that is secured to said legs tends to resist torsional loads exerted thereon in response to loads exerted transversely on said sign panel. 26. A sign and stand apparatus according to claim 25, wherein each of said clamping members includes a clamping face thereon adapted for a generally flat clamping engagement with one of said opposite surfaces of said sign panel, a number of longitudinally-spaced fasteners extending in a generally lateral direction through said clamping members and said lower peripheral portion of said sign panel, said fasteners being adapted to forcibly maintain said clamping members in said flat clamping engagement with said opposite surfaces of said sign panel. 27. A lightweight and readily portable sign and stand apparatus, comprising an elongated base assembly, a plurality of ground-engaging legs extending transversely from and secured to said elongated base assembly, a one-piece monolithic sign panel having a lower peripheral portion protruding in a generally vertical direction from said elongated base assembly and having at least one generally planar display surface thereon, said base assembly including clamping means for clampingly securing and anchoring substantially the entire length of the lower peripheral portion of said sign panel to said elongated base assembly in a generally fixed relationship therewith, said sign panel being sufficiently rigid to be self-supporting in said generally vertically protruding relationship with said base assembly but sufficiently flexible and resilient to bendably deflect without yielding in response to predetermined loads exerted thereon in directions transverse to the plane of said display surface, said sign and stand apparatus having a combined center of gravity located a predetermined vertical distance above the ground, said legs being configured to engage the ground at a predetermined horizontal distance from said base assembly, said combined center of gravity remaining horizontally within the confines of the area defined by the locations at which said legs engage the ground during said bendable deflection of said sign panel in order to substantially prevent said sign and stand apparatus from tipping over in response to said predetermined transverse loads, said sign panel, when deflected, having a continuously curved portion defining an airfoil .Iadd.shape.Iaddend., said sign panel having a lower periphery defining means for substantially limiting air flow beneath said sign panel and thereby substantially negating the aerodynamic .[.lift.]. .Iadd.forces .Iaddend.of said .Iadd.airfoil shape .Iaddend..

1985-11-14

en

1987-02-24

US-87637097-V

Sweet cherry cultivar named `Somerset` ABSTRACT A new distinctive cultivar of sweet cherry (Prunus avium) named `Somerset` (formerly tested as NY 6476) which is exceptional in combining 1) firm, highly attractive fruit that resist rain induced fruit cracking, 2) a tree habit that branches more profusely than many other cultivars and which facilitates precocious cropping, and 3) having a unique affinity of genetic compatibility with some hybrid cherry rootstock cultivars that cause genetic incompatibility and early decline in many other scion cultivars. CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation of U.S. application Ser. No. 08/654,785, filed May 28, 1996, now abandoned, which is a continuation of U.S. application Ser. No. 08/148,084, filed Nov. 4, 1993, now abandoned. BACKGROUND OF THE INVENTION In 1960 hybrid cherry seeds created from controlled pollinations between `Van` X `Vic` were harvested at the New York State Agricultural Experiment Station (Station). These seeds were given cold treatment to satisfy their stratification requirement along with other seed derived from our cherry breeding research. In 1961 the population of `Van` X `Vic` seedlings designated as Breeding Record 59433 were planted. This population included a tree located at a site designated as Darrow 3 Row 14 Tree #83 (D3R14T83). This tree bore fruit in 1966 that we observed to have exceptional firmness and skin that is more shiny (glossy) and blacker than the skin of most other dark fleshed, dark skinned sweet cherry cultivars. It was designated NY 6476 and grafted in 1967 to `Mazzard Seedling` sweet cherry rootstocks utilizing the nursery t-budding grafting technique. These grafts produced trees to be used for more tests of this selection's merit. Grafted trees that resulted were planted in 1969 in a Station field designated as Lucey R1T26 and Lucey R2T27. In 1973 further grafted trees resulted from using Lucey R2T27 buds for propagating wood and planting trees grafted to `Mazzard Seedling` rootstocks in a Station orchard designated as Crittenden 29R2T34,T35,T36. Subsequently, third and fourth clonal generations of trees were created utilizing buds for propagating wood taken from the Cr29R2T34 and Cr29R2T35 trees for planting in 1982 at Cr31R5T5 and T6 and Lucey 50 R5T20,T21,T22,T23,T24 and T25 in 1987. These trees were observed, evaluated and harvested and also used as source material for propagating wood for distribution to collaborators in the USA, Canada, Belgium, France, Norway, Romania and Spain under restricted, nondistribution test agreements. Some of these trees have had research observations taken about their performance on a regular basis each year since 1966. DESCRIPTION OF RELATED ART In all test plantings, trees of NY 6476 (now named and released as `Somerset`) bore consistently heavy fruit crops as judged by experienced researchers and cherry orchardists. Some of these trees were tested during blossom time for pollenizer effectiveness and were found to belong to the pollenizer group designated as Group III (S3S4). Trees of `Somerset` have been uniquely precocious in setting fruit earlier in their life time than many other sorts that we have had under test. `Somerset` trees also have had a unique branching habit wherein they have lateral branches that are more numerous than most other cherry cultivars. This branching habit produces more opportunities for flower buds to form on previous season's growth leading to more non-spur fruiting than on most other sweet cherry cultivars that we have observed. The yield potential and realized crops of `Somerset` cherries have been high when compared to cropping efficiency of other cultivars measured as weight of fruits divided by cross sectional area of trunk diameter. There follows comparison of four traits of 29 sweet cherry cultivars and selections including `Somerset` (NY 6476) originally published by Brown et al, HortScience 23:902-904. (1988): For this study, a precise method for measuring both sweet cherry flesh and skin strength was required. The Instron Universal Testing Machine was chosen because it has been used to measure effectively components of firmness in fruit crops. The objective of the present study was to evaluate both total firmness (skin and underlying flesh) and flesh firmness of sweet cherry germ plasm by means of the Instron puncture test. We wanted to determine how effectively differences in these two components of firmness cound be detected within and between sweet cherry selections and cultivars. To provide a representative sample of material being used in breeding, standard cultivars were included in this study, along with several promising New York selections that were obtained by open pollination or from hybridizations between commercially important cultivars (Table 1). The objective was to assess the variability present within the breeding program for these components of firmness. The material being tested would also provide and objective assessment of how New York breeding selections compare with standard commercially grown cultivars. Fruit and plant characteristics thought to be indicative of fruit maturity were also measured. These included fruit weight, the dimensions of the fruit (length, breadth, and width), soluble solids content (SSC) and fruit removal force (FRF). Correlations between these characteristics and fruit firmness were examined to determine if the firmness of the sample was related to the relative stage of maturity or to any of the other measured characteristics. Fruit samples were obtained from trees grown in an orchard at the New York State Agricultural Experiment Station at Geneva. Since the optimum harvest date of sweet cherries is difficult to assess, previous performance records were used in an effort to ensure that selections and cultivars were harvested at the same relative stage of fruit maturity. The fruit size and color at harvest met commercial standards for the fresh market. Fruit were harvested at the red-mahogany stage as determined by reference to the cherry color comparator #6 (Tech West Enterprises, Ltd., Vancouver, B.C., Canada). There follows comparison of four traits of 29 Sweet cherry cultivars and selections including `Somerset` (NY6476) originally published by Brown et al, HortScience 23:902-904. (1988). TABLE 1 ______________________________________ Parentage of the Cultivars and New York Selections Evaluated Cultivar of Selection Type.sup.z Parentage ______________________________________ Bada W Unknown seedling × Ord Bing B Republican open pollinated Cavalier B Unknown Early Rivers B Early Purple open pollinated Emperor Francis W Unknown Hedelfingen B Unknown Hudson B Oswego × Giant May Duke D Unknown (but sweet × tart cherry) Merton Bounty B Elton × Schrecken Merton Reward B Emperor Francis × Bedford Prolific Moreau B Unknown NY 1507 B Schmidt × Bing NY 3308 B Windsor open pollinated NY 3801 W Bing × NY 1495 [Emperor Francis × Gil Peck] NY 5929 B Kristin [E. Francis × Gil Peck] × S. Hardy. Giant NY 7679 W Pr. 1-638 × NY 5656 [E. Francis × Napoleon] NY 9801 B Schneider open pollinated NY 11390 B Chinook [Bing × Gil Peck] open pollinated Rainier W Bing × Van Sam B (Windsor open pollinated seedling) open pollinated Schmidt B F. Schwarze Knopelkirsche open pollinated Starkrimson B Stella × Garden Bing Stella B Lambert [Napoleon × Black Heart] × J.I.2420 Ulster B Schmidt × Lambert Van B Empress Eugenie open pollinated Victor W Windsor open pollinated Viva B Ukendt × Victor Windsor B Unknown ______________________________________ .sup.z B = dark sweet cherry, W = white fleshed sweet cherry, D = duke One random sample of 30 fruit was harvested from single trees of each cultivar or selection. Individual fruits were weighed and the length (base to apex), breadth (i.e. cheek), and width (i.e. suture) of each fruit was measured in millimeters. Fruit were then placed in refrigerated storage 4.5° C. for several hours before Instron testing to eliminate any variation due to temperature. Fruit firmness was measured with the Instron Universal Testing Machine (Instron Corp., Canton, Mass.). Full scale load was set at 5. The crosshead speed was 5 cm·min-1, and chart speed 10 cm·min-1. Intact fruit was positioned so that the stem was in the horizontal plane. The skin of the fruit was punctured with a #41 drill blank (probe diameter 2.4 mm) on the area of the cheek to the right of the suture and the maximum force measured in newtons. Skin was removed from an adjacent area of the cheek on the opposite side of the suture and the same procedure was repeated to determine flesh firmness. Fruit removal force (FRF), or the force required to remove the fruit from its stem, was determined using a Hunter mechanical Force Gauge (Ametek, Inc., Hatfield, Pa.). Fruit SSC was measured on the expressed juice of individual fruit with a hand-held refractometer. All characteristics were analyzed by a one way analysis of variance (ANOVA) with cultivar being the variable. Means were separated by the method of LSD at the 5% level. The ANOVA established significant cultivar effects for all fruit quality characteristics. The means for flesh and total puncture values, SSC, and fruit removal force are presented in Table 2. The cultivars and selections are arranged in order of their flesh puncture values, from the firmest (the highest value) to the softest. Although fruit color is used commercially to gauge maturity, fruit removal force, fruit size, weight, and SSC are other important characteristics that can be used to assess fruit maturity. It was initially thought that some of the differences in firmness might be attributed to differences in maturity, but we found that the correlation between SSC and the flesh puncture value was not significant. The correlations between the flesh and total puncture values and FRF also were not significant (Table 3). This is evident when comparing firmness values of selections and cultivars with the same relative FRF, such as `Van` and `Hedelfingen` (Table 2). TABLE 2 ______________________________________ Means for Instron Puncture Values of Flesh Firmness and Total Firmness (skin and flesh combined), Soluble Solids Content (SSC), and Fruit Removal Force (FRF) of Sweet Cherry Cultivars and Selections Cultivar Flesh Total SSC FRF or Selection (N) (N) (% Brix) (g) ______________________________________ Moreau 1.28 a.sup.z 3.73 ef 14.2 mn 609 bc NY 6476 1.21 ab 4.17 bcd 16.5 fgh 422 f-j Emperor Francis 1.13 b 4.44 ab 17.4 cde 550 d Ulster 0.97 c 4.22 bc 19.1 ab 466 ef NY 3801 0.97 c 3.20 ijk 13.7 n 632 ab Rainier 0.95 c 3.91 de 17.0 d-g 435 f-i NY 9801 0.80 d 3.77 ef 18.9 ab 419 g-k NY 1507 0.79 d 4.66 a 19.4 a 391 ijk NY 5929 0.78 d 3.18 ijk 19.4 a 342 lm NY 3308 0.78 d 3.21 ij 15.9 hij 489 c Hudson 0.77 de 3.90 de 17.7 cd 569 cd Bing 0.76 de 3.38 ghi 19.1 ab 326 m Schmidt 0.76 de 3.42 ghi 18.6 b 397 h-k Cavalier 0.74 def 3.93 cde 15.5 jk 465 ef Van 0.73 def 2.78 mn 18.9 ab 436 fgh Starkrimson 0.72 d-g 3.41 ghi 14.0 n 611 bc NY 11390 0.69 c-h 3.05 j-m 19.4 a 554 d Sam 0.66 f-j 3.35 hi 14.9 klm 658 a Bada 0.63 g-j 3.56 fgh 17.3 cde 430 f-j NY 7679 0.62 hij 3.20 ijk 17.1 def 270 n Windsor 0.58 ijk 2.92 k-n 15.8 ij 419 g-k Stella 0.55 jkl 3.21 ij 16.0 hij 573 cd Victor 0.54 jkl 3.67 efg 15.0 kl 498 e Viva 0.51 klm 3.13 i-l 16.9 efg 386 jkl Hedelfingen 0.49 klm 2.88 lmn 14.8 lm 412 h-k Merton Reward 0.48 lm 3.03 j-m 16.4 ghi 380 kl May Duke 0.43 mn 2.67 no 17.9 c 501 c Early Rivers 0.42 mn 2.34 p 13.9 n 460 efg Merton Bounty 0.39 n 2.39 op 17.0 d-g 426 f-j ______________________________________ .sup.z Means within a column separated by LSD, P = 5%. Each number is the mean value for 30 fruit. The correlations presented are across all genotypes, but correlations within genotypes followed the same pattern. The lack of any large, significant correlations between firmness and the characteristics commonly used to indicate harvest maturity (Table 3) shows that the time of sampling did not bias the firmness results. Now that the use of the Instron for detecting differences in firmness has been established, the issue of determination of optimum harvest maturity can be addressed in future studies. The correlations between puncture force and the other fruit characteristics were either not significant or below 0.35, indicating that indirect selection for firmness would not be feasible. The correlation coefficient of 0.49 between flesh and total puncture force values suggests that a high total puncture force does not ensure that flesh values will also be high (Table 3). TABLE 3 ______________________________________ Correlation Coefficients Between Fruit Characteristics Across 29 Genotypes of Sweet Cherry Flesh Total SSC FRF Wt Diam ______________________________________ Flesh -- Total 0.49** -- SSC NS 0.20** -- FRF NS NS -0.32** -- Weight 0.22** NS NS NS -- Diameter 0.32** 0.23** 0.22** NS 0.96** -- ______________________________________ NS/**Nonsignificant or significant at the 1% level, respectively. The total firmness force value is not only an indication of skin strength, but is influenced by the firmness of the underlying flesh, so that the value obtained is a mixture of the two components. Therefore, when the percentage of flesh firmness to total firmness is calculated the values are surprisingly low, ranging from 15% to 34%. This does not suggest that the skin alone is responsible for the remaining percentage, but rather that it is the interaction of the skin and flesh. When cultivars of similar total firmness are compared, the differences is flesh firmness can be large. This is found throughout the range of total firmness values as evidenced by the three pairs shown. The difference in the magnitude of flesh vs. total firmness has important implications in choosing cultivars for use in genetic improvement. A genotype with high flesh and high total values is preferred. Where genotypes have a high total value with a low flesh value, it is primarily the skin that is responsible for the perceived firmness. The strong contribution of skin to total firmness is evident in the case of NY 1507 and `Victor` where the flesh accounts for only 17% and 15% of the total firmness, respectively. To emphasize the importance of flesh firmness to the perception of total firmness, `Van` is regarded as being firm, yet in total firmness it ranks very low. However, the flesh is very firm and accounts for a relatively high percentage (26%) of the total value. The flesh texture of `Van` may be responsible for its reputation for firmness. Examination of Table 1 reveals that many commercial cultivars share a common parentage, with `Napoleon` found several times in the pedigree of the firmer selections (Tables 1 and 2). The firmness values of several New York selections are higher than the commercial cultivars used in their development. Several New York selections are as firm as the commercially important `Bing` in both total and flesh firmness with NY 6476, `Somerset`, being firmer than `Bing` in both categories. Use of the Instron not only allows us to identify those sources of firmness to be used in breeding, but also enables us to evaluate the progeny for both components of firmness. Studies of progenies resulting from hybridizations between the firmest cultivars and selections will provide greater understanding of the inheritance of firmness. This may aid the improvement in fruit firmness, which should greatly extend the storage life of the sweet cherry and result in improved fruit quality in the marketplace. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph showing fruits and stems of `Somerset` cultivar. FIG. 2 is a photograph showing pits of fruit of `Somerset` cultivar. FIG. 3 is a photograph showing an intact tree with leaves and fruit thereon for `Somerset` cultivar. FIG. 4 is a photograph of a flower grouping and immature leaves for `Somerset` cultivar. FIG. 5 is a photograph of a single flower of `Somerset` cultivar. DESCRIPTION OF THE INVENTION This invention relates to a new and distinctive cultivar of the cherry tree, `Somerset`, which we discovered in a test planting belonging to the New York State Agricultural Experiment Station, Cornell University, Geneva, Ontario County, N.Y. This discovery is a product of cherry breeding research program of the New York State Agricultural Experiment Station. Pollination: We have conducted experiments to determine the pollination biology specifics about `Somerset`. Our experiments took the form of field tests to cover the emerging flowers with paper bags and thereby isolate flowers of `Somerset` from bee visitation. Such bagging allowed us to subsequently apply pollen derived from known sources to flowers' stigmas to determine the specific pollination compatibility group to which `Somerset` belongs. It is self unfruitful and belongs to Group III as described by Crane and Brown, 1955. "Incompatibility and varietal confusion in cherries" Sci. Hort., 11 pp. 53-55. This pollination group is rather common amongst commercially important sweet cherry cultivars. `Somerset's` flowers contain ample amounts of viable pollen which is available for cross pollinaation via insect vectors. Flowers open early about one day before `Bing` through the blooming time of sweet cherries in Geneva, N.Y. Although they bloom early compared to most other sweet cherry cultivars, they bear regular, heavy crops under all climatic conditions where they have been tested in various countries and states. Hence, we deduce that the ovaries of `Somerset` flowers are highly fertile. Detailed plant description: Immature leaves, flowers, fruit stems, pits and an intact tree with leaves and fruit thereon are shown in the figures which are individually described in the Brief Description of the Drawings section hereinbefore. The numerical color specifications employed in this patent disclosure are those of The Royal Horticultural Society Color Chart (1976). Flowers and flowering: Flowers born on lateral branches or spurs on branches that are two years old or older (FIG. 4). They also are born from axillary buds of shoots laid down the previous growing season, more so than for most other cultivars that we have observed. Typically, 3 to 5 flowers are produced from spur buds and 3 to 5 flowers are also borne on proximal region axillary buds on the previous season's shoots. Flowers (FIG. 5) are white, single and have no unusal features that distinguish them from those of other sweet cherry cultivars except that they open earlier than most other cultivars. They are structurally typical of Prunus avium with a base number of five petals and about 25 stamens. Pedicels are about 3.5 cm to 4.5 cm long and of intermediate thickness, about 1 mm. Anthers are yellow and pollen is yellow-orange. Self pollinations of `Somerset` are unfruitful. Fruiting habit and fruit: `Somerset` trees which are grafted to the common cherry rootstock, `Mazzard Seedling` (Mazzard), typically have flowers produced after only two growing seasons on trees that have been planted in their orchard position. Fruit is often set on trees which flower for the first time. This high precociousness to bear flowers and set fruit is a distinguishing feature of `Somerset` when it is grafted to Mazzard. The individual fruits of `Somerset` are cordate (slightly heart shaped), their skin color at maturity is greyed-purple 187A with a high sheen. Their flesh color is a slightly lighter shade of greyed-purple, 187B. Fruits are very symmetrical, and medium large compared to most other sweet cherry cultivars. They are about 2.7 to 3.1 cm in diameter of width and 2.4 cm to 3.0 cm long. The pits are round conic with size being medium about 1.1 cm long and 1.0 cm wide across the suture and 80 mm wide in their flatter dimension with slightly protruding tips on the stigmatic ends. A typical fruit is shown in an accompanying photograph. Fruits of `Somerset` resist moisture stress induced cracking better than the `Bing` cultivar. The soluble solids level of `Somerset` fruit is generally above 17 percent and always above 16 percent at maturity in Geneva. The natural acidity level of `Somerset` fruits is higher than many commercially important cultivars. The flavor of `Somerset` fruits is stronly cherry-like and the good balance of natural sugars and natural acidity makes the quality of its fruit particularly appealing to people who prefer tartness in sweet cherry taste. Their flesh is firmer than most other sweet cherry cultivars, about 1.21 Instron units at maturity. They have a fruit removal force at maturity of about 422 grams of pull force. Fruit ripening is about with the `Hedelfingen` and `Lapins` cultivars, which is about 65 days after full bloom in Geneva. Tree habit: `Somerset's` tree habit is low in vigor, spreading with many lateral branches produced along apical portions of about 30% of the previous season's growth. This tree habit and branching structure leads to a round form to the tree crown in mature, unpruned fruiting trees. The trees of `Somerset` produce more lateral limbs that emerge at wider angles to the trunk and to scaffold limbs than most commercial cultivars including `Bing,` `Napoleon,` `Rainier,` `Emperor Francis,` `Sam,` `Hedelfingen,` and `Van.` The lateral limbs are very strongly connected. `Somerset` has never been observed by the inventors to have limb breakage problems even with its heavy cropping capacity. It is a subjective observation that the wide angles of the scaffold limbs and secondary scaffold limbs contribute to the strong crop carrying capacity of `Somerset` trees. `Somerset` trees are slightly less vigorous than most commercial cultivars of sweet cherries and are naturally about 20% smaller than the trees of most commercial cultivars of sweet cherries at 10 years of age. The height and width are expediently held to 10 to 11 feet by pruning. Shoots: `Somerset's` shoots are of medium length with many lateral branches. They have small lenticels. In the autumn after cessation of terminal growth, the color of the bark at the fourth internode above the proximal position is greyed-orange 165A on the side of the stem which is commonly exposed to direct sunlight. The other side of the stem is greyed-yellow 161A. The sun exposed color contrasts to greyed-orange 165B in the `Bing` cultivar. Leaves: Leaves of `Somerset` are medium in leaf area, usually symmetrical, lamella glabrous and smooth with adaxial lamella surface dark yellow-green 137A, abaxial surface yellow-green 147B and margins of mature leaves are usually coarsely double serrate with two primary serrations per cm, glands are reniform and averaging 2 per petiole, stipules are present during early stages of growth but abscise before fruit maturity, petioles 3 to 3.75 cm long, leaf position typically 65 to 75 degrees from the perpendicular shoot. Bark: At Geneva, N.Y., the color of the bark on the north side of the trunks of mature fruiting trees at 50 cm. above the soil line is Greyed-Purple 187B while the `Bing` cultivar has slightly darker bark, namely Greyed-Purple 187A. `Somerset` has elliptical lenticels that are larger in both length (three to five times longer) and height (about twice the height) than those of `Bing.` the lenticels have a line or crack running the full length near their center. They often form a chain that is continous around a high percentage of the circumference of the trunk, whereas, in `Bing,` they are discontinous and much less frequent so that much more smooth bark is present on the lower trunk `Bing` than on `Somerset` so the mature bark of `Somerset` has more and larger lenticels and a somewhat rougher texture than the mature bark of `Bing.` The lenticels of young trees tend to hold the same pattern as they mature. Rootstocks: `Somerset` trees have shown two characteristics that help delineate them as unique when grafted and grown on rootstocks in New York. The `Somerset` scion causes root suckers to emerge from trees grafted to `Mazzard Seedling` under Geneva orchard conditions. Although a few other varieties have a low incidence of this trait in Geneva, `Somerset` nearly always has this feature. When grafted to `Damil,` a cherry rootstock cultivar known to induce genetic incompatibility between the scion and rootstock tissues in many sweet cherry scion cultivars in New York conditions, `Somerset` has not shown typical delayed incompatibility symptoms (reduced lateral branching, yellow-green leaves, premature "flagging" (drooping) of leaves and early cessation of annual growth and premature tree death). Training and pruning: `Somerset` requires much less attention to cultural manipulations like the use of scoring of the bark and growth regulator applications to induce limb emergence than most commercial cultivars. No special manipulations are required to spread the angle of the emerging limbs to a more horizontal position. Precocity of young trees is so high that early cropping tends to pull the limbs down into a habit or tree form that is conducive to heavy flower bud initiation and very high fruit set and yield potential. Because `Somerset` produces a smaller tree compared to most commercial cultivars, `Somerset` trees can be planted at about 20-25% closer spacings in most orchard systems than can commonly grown commercial cultivars. Pruning for renewal of fruiting woods is somewhat greater for `Somerset` than is necessary for most commercial cultivars that have less branching and later and lighter croppping. For the home gardner/orchardist, the unique characteristics of ease of training and smaller tree size on comparable rootstocks allow for better utilization of lawn/yard/garden space and earlier production of home grown fruit. Although `Somerset` has a tendency in some years to overset its cropload and then produces smaller fruit size in that season, there are no known cultural practices that thin crop load besides heavy pruning to cut off limbs that would have born "extra" fruit. The pull force for `Somerset` is satisfactory for harvesting by commercial processing operations. Usefulness `Somerset` sweet cherry is well suited for production to fulfill certain fresh market demands in most major sweet cherry production regions of the USA and other countries. The particularly favorable features of this cultivar are its firm, attractive, good flavored fruit, borne precociously on a uniquely branching tree. The tree's precocity coupled with its fruiting profusely on both spurs and previous season's growth and its affinity for some size contolling rootstocks make it desirable for high density orchard plantings, a much needed approach for more profitable sweet cherry production in some areas of the world. `Somerset` will require a pollenizer cultivar interplanted with it which will bloom at the same, early flowering season and which is not in the Group III pollination category. In our field observations of `Somerset` we have noted better tolerance to rain induced fruit cracking than most other cultivars with comparable fruit firmness. Thus, the inventors believe that `Somerset` is highly likely to replace the primary mid-late season cultivar in the Great Lakes Region, `Hedelfingen,` because it has higher yields of firmer more attractive fruit. The productivity of `Somerset` was among the top five of 16 sweet cherry cultivars tested and the 16 cultivers were selected for further screening from over 50 cultivers. In the same test, `Somerset` tied for first in firmness and its percent cracked fruit is amongst the lowest. Disease and pest resistance: In those cases where `Somerset` clusters, it is more susceptible to brown rot than most other commercially grown cultivars of sweet cherry but not more susceptible to brown rot than several newer self-fertile cultivars including `Stella,` Lapins' and `Vandalay` and ultra heavy setting self-incompatible cultivars like `Van` which suffer from brown rot infections as much or more than `Somerset.` In seasons where rains occur during final fruit maturation, `Somerset,` with its somewhat higher tolerance to rain-induced fruit cracking has less incidence of brown rot than commercially important, highly crack-susceptible cultivars such as `Van.` Turning now to leaf infections, `Somerset` has greater susceptibility to leaf infections caused by the bacteria Pseudomonas syringae than do the commercially important cultivars `Emperor Francis,` `Starks Gold,` `Sam,` `Hedelfingen,` `Rainier,` and `Van,` but less susceptibility to leaf infections than `Bing,` `Napoleon,` `Lapins,` and `Newstar.` The tolerance of `Somerset` to wood/bark infection is rated as better than that of `Rainier,` `Van,` `Bing,` `Napoleon,` `Lapins,` and `Newstar` based on experiments at Geneva, N.Y. Turning now to X-disease, `Somerset` is less tolerant to X-disease than the two cultivars existing with tolerance to X-disease, namely `Sweet Ann` and `Angela,` but these two cultivars are not commercially viable. Susceptibility to other graft transmissible pests is not known for `Somerset.` To fulfill the need for uninfected propagating stocks, `Somerset` has been indexed by the Washington State University NRSP5 Project at Prosser, Wash. and uninfected propagating stocks are supplied to commercial nurseries. No known difference in tolerance to insects and nematode pests exists for `Somerset.` Other cultivars: The `Cavalier` and `Starkrimson` cultivars mentioned in the tables hereinbefore are known to be patented in the United States. The other cultivars listed in said tables that have names and not numbers are known to have been released for commerce without plant patent protection. So far as the numerical accessions in the tables are concerned, NY3308 and NY11390 are the subject respectively of U.S. Plant patent application Ser. Nos. 08/835,640 and 08/831,762. What is claimed is: 1. A new and distinct cultivar of sweet cherry tree substantially as herein described and illustrated.

1997-06-13

en

1999-11-09

US-19393680-F

Scrub brush FIG. 1 is a front perspective view of the scrub brush, showing my new design; FIG. 2 is a bottom perspective view thereof; FIG. 3 is a rear perspective view thereof; FIG. 4 is a bottom plan view thereof. The brush is substantially symmetrical about its longitudinal axis. The ornamental design for a scrub brush, as shown and described.

1980-10-06

en

1983-07-05

US-34392682-F

Letter paper with design of two movable eyes FIG. 1 is a perspective view of a letter paper with design of two movable eyes showing my new design; FIG. 2 is a right side elevational view; FIG. 3 is a left side elevational view; FIG. 4 is a top plan view; FIG. 5 is a bottom plan view; FIG. 6 is a front elevational view; and FIG. 7 is a rear elevational view thereof. The ornamental design for a letter paper with design of two movable eyes, as shown.

1982-01-29

en

1984-09-25

US-34864382-F

Toy tricycle FIG. 1 is a side elevational view of a toy tricycle showing our new design, the side opposite being substantially a mirror image; FIG. 2 is a rear elevational view thereof; FIG. 3 is a front elevational view thereof; FIG. 4 is a top plan view thereof; and, FIG. 5 is a bottom plan view thereof. The ornamental design for toy tricycle, as shown and described.

1982-02-12

en

1984-06-19

US-63347990-F

Dust pan FIG. 1 is a top, perspective view of a dust pan showing my new design; FIG. 2 is a side elevational view thereof, the opposite side being a mirror image; FIG. 3 is a top plan view thereof; FIG. 4 is a front elevational view thereof; FIG. 5 is a rear elevational view thereof; and, FIG. 6 is a bottom plan view thereof. The ornamental design for a dust pan, as shown and described.

1990-12-26

en

1993-04-20

US-81768092-F

Seat cushion FIG. 1 is a top, perspective view of a seat cushion showing our new design; FIG. 2 is a top plan view thereof; FIG. 3 is a front elevational view thereof; FIG. 4 is a rear elevational view thereof; and, FIG. 5 is a side elevational view thereof, with the opposite side being a mirror image thereof. The bottom of the design is flat and unornamented. The ornamental design for a seat cushion, as shown and described.

1992-01-07

en

1994-03-15

US-68622284-F

Fishing lure head FIG. 1 is a right side elevational view of my new lure head, which is a mirror image of the left side elevational view; FIG. 2 is a front end view of the lure head; FIG. 3 is a rear end view of the lure head; FIG. 4 is a right side elevational view of another embodiment of the lure head, and is a mirror image of the left side elevational view; FIG. 5 is a front end view of the lure head of FIG. 4; FIG. 6 is a rear end view of the lure head of FIG. 4; and FIG. 7 is a cross-sectional view of the lure head of FIG. 4 on line 7--7. The ornamental design for a fishing lure head, as illustrated and described.

1984-12-24

en

1988-04-26

US-1261393-F

Ornamental child&#39;s pillow in the fanciful form of a rabbit FIG. 1 is a perspective view of the pillow taken from above the left front corner; FIG. 2 is a top plan view thereof; FIG. 3 is a perspective view thereof taken from below the right rear corner; and, FIG. 4 is a bottom plan view thereof. The stippled shading represents conventional fabric and is understood to extend uniformly throughout the areas represented. The ornamental design for an ornamental child's pillow in the fanciful form of a rabbit, as shown and described.

1993-09-07

en

1994-06-28

US-82444092-F

Flower pot cover FIG. 1 is a perspective view of a flower pot cover showing my new design, the lace pattern which is partially shown is understood to repeat uniformly across the inner and outer surfaces; FIG. 2 is a top plan view thereof; FIG. 3 is a bottom plan view thereof; FIG. 4 is a side elevational view thereof, all sides being identical; and, FIG. 5 is an enlarged plan view of the pattern shown in FIG. 1. The flower pot cover has no substantial thickness. The ornamental design for a flower pot cover, as shown and described.

1992-01-23

en

1993-01-12

US-2647594-F

Writing surface and enclosure for supplies FIG. 1 is a right front perspective view of the writing surface and enclosure for supplies; FIG. 2 is a top plan view thereof; FIG. 3 is a left side elevational view thereof; FIG. 4 is a right side elevational view thereof; FIG. 5 is a front elevational view thereof; FIG. 6 is a rear elevational view thereof; FIG. 7 is a bottom view thereof; and, FIG. 8 is a right front perspective view thereof shown in the open position. The ornamental design for a writing surface and enclosure for supplies, as shown and described.

1994-07-28

en

1995-07-25