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FIELD OF THE INVENTION
This invention relates to the use of silicon nitride as a gallium diffusion barrier during molecular beam epitaxial growth of gallium arsenide compounds on silicon sub-micron metal oxide semiconductor (MOS) electronics. More particularly, the present invention relates to a technique for the deposition of silicon nitride films by plasma enhanced chemical vapor deposition (PECVD) in which the composition of the gas employed during the deposition process is controlled within a specific range.
BACKGROUND OF THE INVENTION
The use of optical interconnects for silicon integrated circuits has been employed heretofore to take advantage of the greater capacity of optoelectronics for communications while retaining the computational advantages of silicon electronics. The integration of optoelectronic devices directly on silicon circuits offers the added advantage that such devices need not be located along the chip edge, thereby enhancing the potential for increasing the "pinout count⃡ of the chip. Accordingly, those skilled in the art have focused their interest upon the molecular beam epitaxial growth of gallium arsenide/aluminum gallium arsenide (GaAs/AlGaAs) multiple quantum well modulators on submicron MOS electronics.
During the growth of gallium arsenide on MOS devices by heteroepitaxy, it is necessary to protect the silicon device from the affect of gallium which readily diffuses into the silicon, so resulting in the formation of a conductive oxide. In order to obviate this limitation, the use of a silicon nitride layer over the oxide has been found to result in a diffusion barrier during molecular beam epitaxial growth. However, in order to assure success of the nitride barrier it is essential that the barrier evidence sufficient resistance to hydrofluoric acid used to clean the silicon surfaces prior to growth. Furthermore, the nitride barrier must evidence sufficient mechanical stability to withstand oxide desorption at temperatures in excess of 900 degrees Centigrade which are necessary for the successful growth of gallium arsenide on silicon without effecting cracking or loss of adhesion. The mechanical stability is especially critical for submicron MOS electronics which have as their top dielectric layer a glass which liquefies at 850 degrees Centigrade to round the edges of contact holes. It is this liquification of the reflow glass which tends to cause failure of the nitride diffusion barrier.
SUMMARY OF THE INVENTION
In accordance with the present invention, the limitations of the prior art methodology are effectively obviated by carefully controlling the processing conditions during plasma enhanced chemical vapor deposition (PECVD) of silicon nitride. More specifically, it has been found that silicon nitride films deposited by plasma enhanced chemical vapor deposition (PECVD) in the absence of ammonia exhibit lower residual stress levels during molecular beam epitaxial growth. Studies have revealed that if the nitrogen to silane ratio during the silicon nitride growth is kept below a value of 400:1 the nitride films do not exhibit stress induced cracking at molecular beam epitaxial growth processing temperatures and further evidence excellent resistance to hydrogen fluoride based etchants.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more readily understood by reference to the following detailed description taken in conjunction with the accompanying drawing wherein:
FIG. 1 is a front elevational view in cross section of a silicon MOSFET structure without metallization for an integrated gallium arsenide modulator prior to molecular beam epitaxial growth; and
FIG. 2 is a graphical representation on coordinates of nitrogen to silane ratio against etch rate (10:1 H 2 O:HF) in Angstroms per minute and refractive index showing the affect of process control on film stress, refractive index and etch rate.
DETAILED DESCRIPTION OF THE INVENTION
The MOS fabrication described is effected in (100) silicon oriented 3 degrees off axis toward the (110) face as normally required for high quality gallium arsenide growth on silicon. Circuits are produced in the silicon by standard technologies which include a reflow glass as the top dielectric layer. Before the metal interconnect lines are deposited on the silicon, the wafers are diced into chips. The chips are then prepared for simulated growth by depositing the silicon nitride diffusion barrier. Each of the chips is cleaned by conventional cleansing techniques and loaded into a chemical vapor deposition chamber. Silicon nitride is then deposited by reaction of nitrogen and silane with a nitrogen to silane gas ratio ranging from 53:1 to 400:1. Then, the chips so treated are loaded into a nitrogen ambient furnace and heated to a temperature within the range of 600 to 1000 degrees Centigrade at a rate of approximately 40 degrees Centigrade per minute and held at that temperature for approximately one (1) hour. Next, the chips so treated are cooled to room temperature and examined for evidence of cracking or adhesion loss due to the thermal cycling process. For comparative purposes, the process was repeated using nitrogen to silane ratios ranging from 400:1 to 1250:1.
The results of such testing in Table I which is set forth below. In the Table, MOS chips which evidenced cracking during thermal cycling have been noted with an asterisk in the temperature columns at the temperature at which cracking was observed for varying nitrogen to silane ratios. Etch rate, in Angstroms per minute, film thickness in Angstrom units and refractive index is also shown in the Table for each of the samples evaluated.
TABLE I______________________________________ Film Re- Cracks Cracks CracksN2:Si Thick- Etch rate fractive @ @ @Ratio ness (Å) (Å/min.) Index 1000° 800° 600°______________________________________ 53:1 800 4 2.753215:1 850 13 2.505250:1 813 15 2.462300:1 753 22 2.347 * *300:1 847 24 2.399320:1 648 23 2.357350:1 782 27 2.315400:1 965 28 2.330 * *430:1 841 54 2.232 * *600:1 961 120 2.091 *700:1 926 206 1.943 * *800:1 795 227 1.999 * *1000:1 860 860 1.908 * *1250:1 902 1804 1.860 * *______________________________________
It will be appreciated that films deposited with a nitrogen to silane ratio less than 300:1 did not evidence cracking. However, all films deposited at nitrogen to silane ratios greater than 400:1 evidenced cracking when cycled at temperatures greater than 800 degrees Centigrade. For comparative purposes, nitride films deposited on bare silicon substrates subjected to the same thermal cycling did not evidence cracking or lose adhesion, so indicating that melting of the underlying reflow glass induces mechanical failure in the silicon nitride films.
With reference now to FIG. 1, there is shown a cross-sectional view in front elevational view of a MOSFET structure employed in the practice of the present invention prior to molecular beam epitaxial growth. Shown in the Figure is a (100) silicon substrate 11 which is oriented 3 degrees off axis. Substrate 11 includes thereon successively a thin film of silicon dioxide 12, a reflowable glass layer 13 such as phosphosilicate glass or BPTEOS which has a lower melting point than that of standard silicon dioxide. The purpose of the reflow glass is to allow the rounding off of the top corners of the contact holes to ensure adequate step coverage during the metallization of transistors. Also shown is silicon nitride diffusion barrier 14 deposited upon glass layer 13. Areas destined for molecular beam epitaxial growth 15 which appear open are typically opened in a processing sequence involving reactive ion etching through the dielectric stack upon the substrate which includes the silicon dioxide, reflow glass and silicon nitride.
With reference now to FIG. 2, there is shown a graphical representation on coordinates of nitrogen to silane ratio against wet etch rate (10:1 H 2 O:HF) in Angstroms per minute and refractive index. The data plotted thereon reveals the effect of the control of growth parameters on these characteristics. It will be noted by examination of the graphical data that there is a sharp rise in etch rate with a corresponding drop in refractive index at gas ratios greater than 800:1. At gas ratios in the range of 300:1 to 400:1, there is evidence of slight instability as the refractive index tends to behave non-linearly.
An example of the application of the present invention is set forth solely for purposes of exposition and is not to be construed as limiting.
EXAMPLE
A group of CMOS circuits with 0.9 micrometer line width rules, not including a silicon nitride diffusion barrier, was separated into chips suitable for individual processing. Each chip was subjected to identical cleaning procedures involving ten (10) minute treatments with a 10:1 aqueous sulfuric peroxide solution followed by a distilled water rinse. Then, lots of three (3) chips were loaded into a single wafer parallel plate PECVD chamber together with several bare silicon samples. Each lot was then coated with silicon nitride deposited from an ambient comprising nitrogen and silane in varying gas ratios ranging from 53:1 to 1250:1 (nitrogen to silane). The reaction chamber employed was a standard glow discharge parallel plate plasma reactor. The gases were supplied through a uniform array of holes in an rf-powered counterelectrode 15 centimeters in diameter spaced 3 centimeters away from the substrate. The nitrogen flow was within the range of 100 to 400 sccm and the silane flow rate varied from 0.2 to 2.2 sccm. RF frequency was 13.56 MHz. The substrate temperature was maintained at 350 degrees Centigrade during film deposition. The bare silicon samples were used to determine deposited nitride thickness, etch rate in dilute (10:1) hydrofluoric acid in water and refractive index. Thickness and refractive index were determined using a commercial ellipsometer. One MOS chip from each lot was then loaded into a nitrogen ambient furnace and ramped to 600 degrees, 800 degrees or 1000 degrees Centigrade at a rate of 40 degrees per minute. The chips were held at the desired temperature for sixty (60) minutes and allowed to cool to room temperature over a three hour period. After reaching room temperature, each chip was examined for evidence of cracking or adhesion loss due to thermal cycling.
Based upon the data set forth in the Table and in FIG. 2, it is evident that the dominant factor pertaining to silicon nitride growth in the absence of ammonia in a plasma enhanced chemical vapor deposition process is the nitrogen to silane gas ratio. Thus, maintaining the ratio at 300:1 or less results in the reduction of film stress to a level which permits one to thermally stress the wafers employed without running the risk of causing mechanical failure of the nitride film. Furthermore, the etch rate using hydrofluoric acid can be controlled to the point where the silicon nitride film is almost impervious to the acid or is capable of being adjusted such that etching is effected at a rate in excess of 1500 Angstroms per minute solely by varying the nitrogen to silane gas ratio. This ability to tailor the film stress and etch rate is critical in the integration of these technologies and finds particular application in the growth of gallium arsenide by heteroepitaxy on silicon CMOS devices.
The described technique is of particular interest in the monolithic integration of interconnected GaAs/AlGaAs double heterostructure modulators and silicon MOSFET structures. In this process, it is necessary to cover the wafer of interest with successive layers of silicon dioxide and a layer of silicon nitride to protect the MOSFET structures during gallium arsenide epitaxy and subsequent processing
While the invention has been described in detail in the foregoing specification and in the exemplary embodiment, it will be appreciated by those skilled in the art that many variations may be made without departing from the spirit and scope of the invention.
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A technique is described for the preparation of a thin film of a silicon nitride diffusion barrier to gallium on a silicon integrated circuit chip. The technique involves reacting nitrogen and silane in a ratio of 53:1 to 300:1 in a plasma enhanced chemical vapor deposition apparatus. The described technique is of interest for use in the monolithic integration of interconnected GaAs/AlGaAs double heterostructures, modulators and silicon MOSFET structures.
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BACKGROUND INFORMATION
[0001] 1. Field
[0002] Embodiments of the disclosure relate generally to the field of packaging for pastry and baked goods and more particularly to a multidiametric case for a cupcake or similar good, the case having a relieved upper portion for clearance of frosting or topping, an aperture in the bottom allowing easy removal of the cupcake from the package and retaining elements within the case for closely contacting the cupcake for retention in the package until removal.
[0003] 2. Background
[0004] Cupcakes and similar baked goods and pastries are typically packaged in boxes containing multiple units. Baked goods such as cupcakes are quite fragile in nature and such packaging does not provide satisfactory protection for the baked goods, allowing individual cupcakes to move within the box creating distortion or damage to the soft cake and frosting. Retaining elements within the multiunit box have been previously employed as disclosed in U.S. Pat. No. 6,003,671 issued to McDonnough et al on Dec. 21, 1999. However extracting individual cupcakes is typically not easy or convenient and such packaging is not readily economically adaptable for individual cupcakes.
[0005] Individual packaging has been provided in the form of small boxes or paper wrapping which suffer many of the same issues as multiunit packaging. Certain single item packages such as that disclosed in US patent publication 2004/0251162 to McGinnis et al published on Dec. 16, 2004 have been provided, however, such packaging is overly complex and expensive to be cost effective for high quantity production and sale of baked goods.
[0006] It is therefore desirable to provide a cost effective packaging system for individual cupcakes or similar baked goods. It is additionally desirable that such a packaging system would allow easy removal of the cupcake without damage while retaining the cupcake safely within the package until removal is desired.
SUMMARY
[0007] Exemplary embodiments provide cupcake package employing a base element having a primary diameter for receiving a cupcake body and a relieving cylinder having a second diameter extending from the base element for clearance of a top contour of the cupcake. A bottom surface closes the base element and includes an aperture centrally located therein sized to accept insertion of a finger for removal of the cupcake. A cylindrical lid is closely received over the relieving cylinder to close the package. In one exemplary embodiment the base element is frustoconical.
[0008] In certain implementations, the base element further incorporates a restraint system for the cupcake. A first restraint system includes two sets of opposing apertures in the base element vertically displaced from and perpendicular to each other. A first dowel is received through the first set of apertures and extending through a cupcake body carried in the base element and a second dowel is received through the second set of apertures and extending through the cupcake body.
[0009] A second restraint system incorporates multiple pyramidal protuberances extending from an inner surface of the base element oriented with an extended point downward toward the bottom to engage the body of the cupcake.
[0010] A third restraint system uses one or more circular ridges extruded from an inner surface of the base element to engage the body of the cupcake.
[0011] The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present invention or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a bottom angle isometric view of a general embodiment of the cupcake package of the present invention;
[0013] FIG. 1B is a side view of the embodiment of FIG. 1A ;
[0014] FIG. 1C is a bottom view of the embodiment of FIG. 1A ;
[0015] FIG. 1D is a top angle isometric view of the embodiment of FIG. 1A with the closure lid removed;
[0016] FIG. 1E is a side section view of the embodiment of FIG. 1A with a cupcake inserted in the case;
[0017] FIG. 1F is the side section view of the case with the cupcake being removed;
[0018] FIG. 2A is a bottom angle isometric view of an embodiment of the cupcake package with a first restraint structure;
[0019] FIG. 2B is a top angle isometric view of the embodiment of FIG. 2A ;
[0020] FIG. 2C is a bottom view of the embodiment of FIG. 2A ;
[0021] FIG. 2D is a top view of the embodiment of FIG. 2A showing interior details of the embodiment;
[0022] FIG. 2E is a side section view of the embodiment of FIG. 2A ;
[0023] FIG. 3A is a top isometric view of an embodiment of the cupcake package with a second restraint structure;
[0024] FIG. 3B is a top view of the embodiment of FIG. 3A ;
[0025] FIG. 3C is a side section view of the embodiment of FIG. 3A ;
[0026] FIG. 4A is a top isometric view of an embodiment of the cupcake package with a third restraint structure; and,
[0027] FIG. 4B is a side section view of the embodiment of FIG. 4A .
DETAILED DESCRIPTION
[0028] The embodiments described herein disclose a cupcake package having a multidiametric case with multiple cylindrical elements or a combination of cylinders and conical frustrums to receive the cupcake and having a bottom with an aperture for urging the cupcake from the case with a consumer's finger, a lid for closing the case, and various restraint elements within the case to maintain the cupcake in the case until removed.
[0029] As shown in FIG. 1A-1E for an exemplary embodiment, a frustoconical base element 10 of the case with a first primary diameter 11 receives the body of the cupcake (as best seen in FIG. 1E ). The shape of the base element may be a conical frustrum as shown for use with a conventional cupcake or various depths and diameters of cylindrical elements or other rotated geometric shapes defined to closely receive the baked good. The inner surface 12 of the base element frictionally engages the sides of the cupcake to assist in retaining the cupcake in the package and prevent unwanted motion in the package during handling or transport. A cylindrical top element 14 expands from the base element 10 to a second diameter 15 to allow volumetric relief within the package for frosting or top contouring of the cupcake or other baked good to be contained in the case. Further, the larger diameter of the top element simplifies the insertion of the cupcake or baked good into the case.
[0030] A lid 16 having an inner diameter sized to be closely received over the cylindrical top element 14 provides a closure for the case to protect the cupcake or baked good after insertion into the case. For the embodiment shown a filleted external surface of the lid allows for easy grasping by the consumer for removal. In alternative embodiments, a smooth cylindrical external surface or a textured surface may be employed.
[0031] A bottom surface 18 of the base element 10 incorporates an aperture 20 which is sized to accommodate insertion of a fingertip. As best seen in FIG. 1F , after removing the lid, inserting a fingertip through aperture 20 and pressing upward against the bottom 22 of the cupcake urges the cupcake body 24 from the case allowing the consumer to easily remove the cupcake for consumption.
[0032] For the exemplary embodiments, injection molded polystyrene or similar material may be employed for the case and lid providing a very low cost, mass producible product. Alternative paper, cardboard or plastic materials may be employed in alternative embodiments using standard fabrication techniques known to those skilled in the art.
[0033] To further restrain the cupcake in the case, a restraint system is employed. As shown in FIGS. 2A-2E , a first exemplary restraint system for the embodiment shown incorporates apertures 30 in the base element through which wooden or plastic toothpicks or dowels 32 are inserted, piercing the body of the cupcake. The dowel ends extend through the apertures 30 on each side of the base element thereby restraining the cupcake within the case. For the embodiment shown, two perpendicular vertically offset sets of apertures and dowels are employed. In alternative embodiments, a single aperture set and dowel may be employed or additional sets for increased security. For removal of the cupcake, the dowels are extracted from the case and the cupcake is removed by inserting a finger into the aperture 20 in the bottom 18 to urge the cupcake out of the case.
[0034] A second exemplary restraint system is shown in FIGS. 3A-3C which employs pyramidal protuberances 34 extending from the inner surface 12 of the base element 10 . Orientation of the protuberances with point 36 extending downwardly toward the bottom 18 of the base element engages and restrains the body of the cupcake when the cupcake is placed into the case and urged toward the bottom. For the embodiment shown, four pyramidal protuberances 34 are shown. In alternative embodiments one or more protuberances may be employed as required to firmly secure the cupcake or other backed good in the case. For removal of the cupcake, inserting a finger into the aperture 20 in the bottom 18 and urging the cupcake upwards with sufficient force overcomes the friction created by the indentation of the pyramidal protuberances in the body of the cupcake allowing it to be removed from the case.
[0035] Ridges 38 extruded from the inner surface 12 of the base element 10 provide a third exemplary retention system for the embodiments disclosed as shown in FIGS. 4A and 4B . For the embodiment shown, the ridges extend around an entire circumference of the inner surface and two ridges are employed. In alternative embodiments ridges extending over a portion of the circumference or a single or additional multiples of ridges are employed. A substantially circular cross section of the ridges is employed which provides sufficient resistance against the body of the cupcake to retain the cupcake in the case. However, alternative cross sections such as triangular or rectangular may be employed in alternative embodiments. As with the pyramidal protrusions, removal of the cupcake is accomplished by inserting a finger into the aperture 20 in the bottom 18 and urging the cupcake upwards with sufficient force overcomes the friction created by the indentation of the circular ridges in the body of the cupcake allowing it to be removed from the case.
[0036] Having now described various embodiments of the invention in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present invention as defined in the following claims.
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A cupcake package includes a base element having a primary diameter for receiving a cupcake body and a relieving cylinder having a second diameter extending from the base element for clearance of a top contour of the cupcake. A bottom surface closes the base element and includes an aperture centrally located therein sized to accept insertion of a finger for removal of the cupcake. A cylindrical lid is closely received over the relieving cylinder to close the package.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an absorption type refrigerating machine comprising an evaporator, an absorber, a regenerator and a condenser which are connected by piping to form a refrigerating cycle.
2. Background Art
Heat transmission pipes provided in an evaporator of an absorption refrigerating machine are disclosed in, for example, Japanese Utility Model Publication No. 40776 of 1978 wherein a cooling water running in each heat transmission pipe is cooled by a refrigerant dispensed over the outer surface of the heat transmission pipe using a refrigerant dispenser.
In the prior art as described above, since the outer and inner surfaces of the heat transmission pipe are smooth, the cooling water running in the pipe can flow smoothly through the pipe without being sufficiently agitated. As a result, the heat transfer coefficient between the cooling water and the heat transmission pipe is low, disadvantageously requiring an increase of the number of the heat transmission pipes and, hence, the volume of the evaporator in order to secure a certain amount of transferred heat. In addition, when heat transmission pipes having smooth inner and outer surfaces are used for a condenser or absorber, similarly to the case of the evaporator, a water running in each heat transmission pipe can not be sufficiently agitated, with the heat transfer coefficient being low between the cooling water and the heat transmission pipe. In order to secure a certain amount of transferred heat, that is, a cooling capacity at the condenser or absorber, therefore, the number of the heat transmission pipes must be increased, disadvantageously increasing the volume of the condenser or absorber and, similarly to the above described problem with the evaporator, enlarging the absorption type refrigerating machine.
In order to solve the problem as above described, spiral pipes each having a protrusion formed on the inner wall of the pipe are used for an evaporator. Among such pipes, those in which the pitch of the protrusion is small and about 0.4 to 0.5 times of the outer diameter of the heat transmission pipe are widely used, so that a turbulent effect may be produced by the protrusion to improve the heat transfer coefficient in the pipe to increase the amount of exchanged heat. Since the pitch is small, however, when a refrigerant is dispensed from above onto a group of heat transmission pipes of the evaporator or the like in which the heat transmission pipes are provided in a plurality of vertical stages, the refrigerant tends to gather at the lower part of the heat exchanger due to a groove on the outer wall of each pipe corresponding to the protrusion, creating a problem that a dry heat transfer surface will be exposed to decrease the heat transfer performance and, hence, the refrigerating capacity. Moreover, if the depth of the spiral groove is greater, the refrigerant will penetrate into the grooved area instead of spreading over the outer surface of the heat transmission pipe, further impairing the wetting over the heat transfer surface. If the pitch of a protrusion is small also in an absorber, an absorbent will gather on the outer surface of each heat transmission pipe to expose a dry heat transfer surface, impairing the absorbing capacity of a refrigerant vapor.
SUMMARY OF THE INVENTION
It is the object of the present invention to improve the refrigerating capacity of an evaporator and the refrigerant absorbing capacity of an absorber to provide an enhanced and downsized absorption type refrigerating machine.
In order to achieve the object, according to a first aspect of the present invention, an absorption type refrigerating machine is provided comprising an evaporator which cools a cooling water by vaporization of a refrigerant to supply the cooling water to a load; an absorber into which a refrigerant vapor from the evaporator flows and in which a concentrated absorbent is dispensed to absorb the refrigerant vapor by the concentrated absorbent; a regenerator which heats a diluted absorbent from the absorber to separate a refrigerant vapor therefrom; and a condenser into which the refrigerant vapor from the regenerator flows and in which the refrigerant vapor is condensed, the elements all connected by piping to form a refrigerating cycle, the evaporator including a plurality of heat transmission pipes accommodated therein and arranged generally in a horizontal direction, each pipe having at least one continuity of protrusion on the inner surface thereof extending in the axial direction of the pipe in a spiral fashion and at least one continuity of groove corresponding to the continuity of protrusion formed on the outer surface of the pipe, the ratio of the pitch of the groove of each heat transmission pipe to the outer diameter dimension of the pipe being set within the range of 0.5 to 1.25; and a dispenser provided above the heat transmission pipes for dispensing the refrigerant, the ratio of the pitch of the groove of the heat transmission pipe to the refrigerant dispensation pitch of the dispenser being set within the range of 0.6 to 1.4.
According to a second aspect of the present invention, the groove of each heat transmission pipe is 0.5 mm to 5 mm in width, 0.3 mm to 0.7 mm in depth and 0.5 mm to 1 mm in radius of curvature.
According to a third aspect of the present invention, the protrusion on the inner surface of each heat transmission pipe is 0.3 mm to 0.6 mm in height.
According to a fourth aspect of the present invention, the outer surface of each heat transmission pipe is buffed and finished.
According to a fifth aspect of the present invention, an absorption type refrigerating machine is provided comprising an evaporator which cools a cooling water by vaporization of a refrigerant to supply the cooling water to a load; an absorber into which a refrigerant vapor from the evaporator flows and in which a concentrated absorbent is dispensed to absorb the refrigerant vapor by the concentrated absorbent; a regenerator which heats a diluted absorbent from the absorber to separate a refrigerant vapor therefrom; and a condenser into which the refrigerant vapor from the regenerator flows and in which the refrigerant vapor is condensed, the elements all connected by piping to form a refrigerating cycle, the condenser including a plurality of heat transmission pipes accommodated therein and arranged generally in a horizontal direction in which the cooling water flows, each pipe having at least one continuity of protrusion on the inner surface thereof extending in the axial direction of the pipe in a spiral fashion and at least one continuity of groove corresponding to the continuity of protrusion formed on the outer surface of the pipe, the groove of the heat transmission pipe being 0.5 mm to 5 mm in width, 0.3 mm to 0.7 mm in depth and 0.5 mm to 1 mm in radius of curvature and the ratio of the pitch of the groove of the heat transmission pipe to the outer diameter dimension of the pipe being set within the range of 0.5 to 1.25.
According to a sixth aspect of the present invention, an absorption type refrigerating machine is provided comprising an evaporator which cools a cooling water by vaporization of a refrigerant to supply the cooling water to a load; an absorber into which a refrigerant vapor from the evaporator flows and in which a concentrated absorbent is dispensed to absorb the refrigerant vapor by the concentrated absorbent; a regenerator which heats a diluted absorbent from the absorber to separate a refrigerant vapor therefrom; and a condenser into which the refrigerant vapor from the regenerator flows and in which the refrigerant vapor is condensed, the elements all connected by piping to form a refrigerating cycle, the absorber including a plurality of heat transmission pipes accommodated therein and arranged generally in a horizontal direction in which the cooling water flows, each pipe having at least one continuity of protrusion on the inner surface thereof extending in the axial direction of the pipe in a spiral fashion and at least one continuity of groove corresponding to the continuity of protrusion formed on the outer surface of the pipe; and a dispenser provided above the heat transmission pipes for dispensing the concentrated absorbent, the groove of the heat transmission pipe being 0.5 mm to 5 mm in width, 0.3 mm to 0.7 mm in depth and 0.5 mm to 1 mm in radius of curvature, the ratio of the pitch of the groove of the heat transmission pipe to the outer diameter dimension of the pipe being set within the range of 0.5 to 1.25, and the ratio of the pitch of the groove of the heat transmission pipe to the absorbent dispensation pitch of the dispenser being set within the range of 0.6 to 1.4.
According to the first aspect of the present invention, part of the refrigerant dripped onto each heat transmission pipe of the evaporator will flow along the spiral groove, and the remainder of the refrigerant will spread over the whole outer surface of the heat transmission pipe. The flow of cooling water running in the pipe will be turbulent by the protrusion. By providing the pitch of the groove at a predetermined ratio to the outer dimension of the pipe and to the refrigerant dispensation pitch, the refrigerant can spread moderately over the surface of the heat transmission pipe. Because of the appropriately provided pitch of the groove, a sufficient turbulent effect in the heat transmission pipe will be obtained by the protrusion corresponding to the groove.
According to the second aspect of the present invention, by providing the groove of a shape having the predetermined dimensions, the refrigerant will flow along the groove and will be prevented from penetrating into the groove, hardly spreading over.
According to the third aspect of the present invention, by providing the height of the protrusion on the inner surface of each heat transmission pipe at a predetermined dimension, a sufficient turbulent effect can be obtained and a flow loss of the heat transmission pipe can be kept at a relatively low level.
According to the fourth aspect of the present invention, wettability of the outer surface of each heat transmission pipe against the refrigerant can further be improved.
According to the fifth aspect of the present invention, the refrigerant condensed on the outer surface of each heat transmission pipe in the condenser will flow intensively along the groove on the outer surface of the pipe and will be prevented from spreading over the whole outer surface of the pipe. A turbulent flow will also be generated in the cooling water by the protrusion formed on the inner surface of the heat transmission pipe, improving the heat transfer efficiency between the cooling water and the heat transmission pipe. By providing the pitch of the groove at a predetermined ratio to the outer dimension of the pipe, the refrigerant will spread moderately over the surface of the heat transmission pipe.
According to the sixth aspect of the present invention, the absorbent dripped onto each heat transmission pipe of the absorber will spread generally over the whole outer surface of the pipe. A turbulent flow will be generated by the protrusion in the cooling water running in the pipe. By providing the pitch of the groove at a predetermined ratio to the outer dimension of the pipe and to the absorbent dispensation pitch, the absorbent will spread moderately over the surface of the heat transmission pipe and, because of the appropriately provided pitch of the groove, a sufficient turbulent effect in the heat transmission pipe will be obtained by the protrusion corresponding to the groove.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of an absorption type refrigerating machine;
FIG. 2 is a side view illustrating the structure of an evaporator;
FIG. 3 is a sectional view of a heat transmission pipe;
FIG. 4 is a graphical representation of the change of performance of a heat transmission pipe of an evaporator where the pitch of a groove is varied:
FIG. 5 is a side view illustrating the structure of a condenser;
FIG. 6 is a graphical representation of the change of performance of a heat transmission pipe of an evaporator where the ratio of the pitch of a groove to the refrigerant dispensation pitch is varied;
FIG. 7 is a graphical representation of the change of performance of a condenser where the pitch of a groove is varied; and
FIG. 8 is a graphical representation of the change of performance of a heat transmission pipe of an absorber where the ratio of the pitch of a groove to the absorbent dispensation pitch is varied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will now be described with reference to the drawings. In FIG. 1, a low temperature evaporator-absorber shell (lower shell) 1 accommodates an evaporator 2 and an absorber 3. A high temperature regenerator 4 includes a gas burner 5 for example. Provided along a diluted absorbent pipe 6 from the absorber 3 to the high temperature regenerator 4 are a first absorbent pump P, a low temperature heat exchanger 7 and a high temperature heat exchanger 8.
A high temperature condenser-regenerator shell (upper shell) 10 accommodates a low temperature regenerator 11 and a condenser 12. Refrigerant vapor pipe 13 extends from the high temperature regenerator 4 to the low temperature regenerator 11. A heater 14 is provided in the low temperature regenerator 11. A refrigerant pipe 15 extends from the heater 14 to the condenser 12. A refrigerant liquid flow pipe 16 extends from the condenser 12 down to the evaporator 2, and a refrigerant circulation pipe 17 is connected by piping to the evaporator 2. Also provided are a refrigerant pump 18 and a refrigerant dispenser 19. A cooling water pipe 21 is connected to the evaporator 2. An evaporator heat exchanger 21A is also provided.
An intermediate absorption pipe 22 extends from the high temperature regenerator 4 to the high temperature heat exchanger 8, and an intermediate absorbent pipe 23 which has an inflow port 23A extends from the high temperature heat exchanger 8 to the low temperature regenerator 11. A second absorbent pump 24 is provided along the intermediate absorbent pipe 23. A concentrated absorbent pipe 25 extends from the low temperature regenerator 11 to the low temperature heat exchanger 7, and another concentrated absorbent pipe 26 extends from the low temperature heat exchanger 7 to the absorber 3. Also provided are a concentrated absorbent dispenser 27, a cooling water pipe 29, an absorber heat exchanger 29A and a condenser heat exchanger 29B.
As illustrated in FIG. 2, the evaporator heat exchanger 21A is composed of evaporator heat transmission pipes 30 which are connected by piping in a plurality of columns and rows. These heat transmission pipes 30 are degreased on the both, outer and inner, surfaces by, for example, an alcohol and are polished and finished on the outer surfaces by, for example, a buff. Supporter portions 30A, 30A are formed at the both ends of each heat transmission pipe 30. The supporter portions 30A, 30A have smooth outer and inner surfaces and are retained by pipe plates 1A, 1A provided at the both ends of the evaporator-absorber shell 1. Each heat transmission pipe 30 is circular in section and has a diameter of, for example, 16 mm over the whole length. Above the heat transmission pipes 30, a dispenser (tray) 19 is provided which has a plurality of drip holes 19a for dispensing refrigerant. Each of the above heat transmission pipes 30 is a corrugated pipe having a spiral shape, and has at least one continuity of groove 31 formed on the outer surface and extending in a spiral fashion. Corresponding to the continuity of groove 31, a continuity of protrusion 32 is formed on the inner surface of the heat transmission pipe.
The continuities of groove 31 and protrusion 32 each have a partially spiraled portions 31B, 31B formed at the both ends where the depth of the groove 31 and the height of the protrusion 32 gradually decrease toward the supporter portions 30A, 30A. The partially spiraled portions 31B, 31B are formed, for example, of a length less than a half of the outer periphery of the heat transmission pipe 30. The terms "continuity of groove 31" and "continuity of protrusion 32" will hereinafter referred to simply as "groove 31" and "protrusion 32," respectively.
If the pitch P of the groove 31 is too small, the amount of the refrigerant dripped which penetrates into the groove 31 will increase, thereby eliminating the lateral spread of the refrigerant, while if it is too large, a turbulent effect produced by the protrusion 32 will be weak. The ratio of the pitch P to the diameter D of the heat transmission pipe, P/D, will therefore be set within the range of 0.5 to 1.25.
Preferably, the pitch P of the groove 31 should generally be the same as the refrigerant dispensation pitch of the dispenser 19, P1, that is, the pitch at which the dispensation holes are provided. The ratio of the pitch of the groove to the refrigerant dispensation pitch should be at least within the range of 0.5 to 1.25. This is because if the pitch P is too small when the refrigerant falls dropwise from the refrigerant dispensation holes, the refrigerant will not spread over the heat transmission pipe 30, and will instead fall directly into the groove 31. Conversely, if the pitch P is too large, the pipe will be rather smooth as if it had no groove 31 formed thereon. As a result, though the heat transmission pipe 30 will be easier to be wetted, the protrusion 32 corresponding to the groove 31 will be less in height, thereby reducing a liquid agitating effect caused by the turbulence generated within the heat transmission pipe 30. The pitch P according to the embodiment of the present invention, which has been adapted to satisfy all the requirements for the pitch P of the groove 31, is, for example, 14 mm. By thus predetermining the pitch, it was demonstrated by experiments that a heat transmission coefficient will improve as much as 20% or more as compared to that of a smooth pipe.
As illustrated in FIG. 3, the depth H of the groove 31 is, for example, 0.4 mm. It should be set at least within the range of 0.3 mm to 0.7 mm. It is 0.7 mm or less in this embodiment because if the depth H is too large, the refrigerant dripped will penetrate into the groove 31 instead of spreading over the outer surface of the heat transmission pipe 30. By predetermining the depth to be rather small, therefore, the refrigerant will tend to spread off the groove. Also, it is 0.3 mm or more because if the depth is too small, the turbulent effect of a cooling water caused by the protrusion 32 corresponding to the groove 31 will decrease.
In addition, the width W of the groove 31 is, for example, 0.9 mm. The width W of the groove 31 herein refers to the width between an inflection point 33 where the curvature of the groove 31 begins and another inflection point 34 where the curvature of the groove of the groove 31 ends. If the width W is too large, the refrigerant dripped will gather at the groove 31. It should therefore be set within the range of 0.5 mm to 5.0 mm. The radius R of the groove should be set within the range of 0.5 mm to 1.0 mm. Not predetermining the R at too small a magnitude will prevent the refrigerant from penetrating into the groove in a hardly withdrawable manner.
The height, that is, a dimension of inward raise, of the protrusion 32 formed on the inner surface of each heat transmission pipe 30 should be set within the range of 0.3 mm to 0.6 mm. This is because if the height is too small, an improvement in the heat exchange efficiency caused by the liquid agitating effect may hardly be obtained, while if it is too large, flow resistance within the heat transmission pipe 30 will be greater, impairing the flow through the pipe.
FIG. 4 graphically represents a ratio of heat transmission coefficient of the heat transmission pipe 30 against that of a smooth pipe where the outer diameter is 16 mm and the pitch of the groove 31 is varied in the heat transmission pipe 30. The depth H of the groove 31 is constantly 0.4 mm and the width of the groove 31 is constantly 0.9 mm. As will be apparent from the result shown in the FIG. 4, if the pitch P is varied from 8 mm to 20 mm, that is, the ratio of the pitch P to the diameter D is varied from 0.5 to 1.25, the heat transmission coefficient will be 1.1 times or more of that in the smooth pipe.
FIG. 6 graphically represents the relationship between the ratio of the pitch P to the refrigerant dispensation pitch P1 and the ratio of the heat transmission coefficient. As shown, it has been found that the heat transmission coefficient will reach the peak where the pitch P of the groove 31 of the heat exchange pipe 30 is approximately the same as the refrigerant dispensation pitch P1. It has also been found that if the ratio of the groove pitch P to the refrigerant dispensation pitch P1 of a dispenser, that is, P/P1, is within the range of 0.6 to 1.4, the heat transmission coefficient will be greater than 1.05, thereby improving the performance of the heat transmission pipe (corrugated pipe) 30 of the evaporator. This is because, as mentioned previously, the pitch P is not too small, allowing the refrigerant to spread moderately over the heat transmission pipe 30 but is not too large either, providing a sufficient liquid agitating effect within the heat transmission pipe 30.
When the pitch P is 7 mm or smaller, that is, too small, the refrigerant will not sufficiently spread over the heat transmission pipe 30, thereby decreasing the heat transmission coefficient. Alternatively, when the pitch P is 21 mm or more, which is too large, a liquid agitating effect can not be obtained, with the heat transmission coefficient decreased.
The condenser heat exchanger 29B of the condenser 12 is, similarly to the evaporator heat exchanger 21A described above, composed of heat transmission pipes 35 which are provided in a plurality of columns and rows. As illustrated in FIG. 5, these heat transmission pipes 35 are corrugated pipes as are the evaporator heat transmission pipes 30 and are retained with the both ends by pipe plates 10A, 10A of the evaporator-regenerator shell 10. A spiral groove 31 is formed on the outer surface of each pipe. The groove 31 has also appropriate dimensions similarly to the case of the evaporator. Namely, the groove 31 has a width of 0.5 mm to 5 mm, a depth of 0.3 mm to 0.7 mm, and a radius of curvature of 0.5 mm to 5 mm. A protrusion 32 is also formed on the inner surface of each heat transmission pipe corresponding to the groove 31. Because poor wettabitity is preferable in order to promote the condensation of refrigerant vapor, no polishing should be made of the outer surface of the heat transmission pipe 35.
FIG. 7 graphically represents the performance of a corrugated pipe composing a heat transmission pipe 35 of the condenser heat exchanger 29B. The abscissa axis of the illustration represents the spiral pitch of the corrugated pipe, that is, the pitch of a groove. The ordinate axis represents a ratio (K/(P, wherein (K represents a performance ratio of heat transmission coefficient of the corrugated pipe to that of a smooth pipe (bare pipe) and (P represents a ratio of pressure loss of the corrugated pipe to that of a smooth pipe. Namely, the ordinate axis represents the performance of the corrugate pipe using non-dimensional numbers, wherein more than 1 means a good performance and less that 1 means a poor performance. The corrugated pipe has an outer diameter of 16 mm. As can be seen from the illustration, when the pitch of the groove is 8 mm to 20 mm, the ratio (K/(P is greater than 1.05. It has therefore been found that this embodiment will be effective when the ratio of the groove pitch of the heat transmission pipe to the outer diameter dimension of the pipe is 0.5 to 1.25.
The absorber heat exchanger 19A of the absorber 3 is, similarly to the evaporator heat exchanger 21A described above, composed of heat transmission pipes 35 which are provided in a plurality of columns and rows. The arrangement is analogous to the one shown in FIG. 5, and, therefore, no particular illustration will be referred to. These heat transmission pipes 35 are corrugated pipes as are the evaporator heat transmission pipes 30 and are retained with the both ends by the pipe plates 10A, 10A of the evaporator-regenerator shell 10. A spiral groove 31 is formed on the outer surface of each pipe. The groove 31 also has appropriate dimensions similarly to the case of the evaporator. Namely, the groove 31 has a width of 0.5 mm to 5 mm, a depth of 0.3 mm to 0.7 mm, and a radius of curvature of 0.5 mm to 1 mm. A protrusion 32 is also formed on the inner surface of the heat transmission pipe corresponding to the groove 31.
The relationship between the pitch of the groove 31, that is, the spiral pitch and the heat transmission coefficient is similar to that illustrated in FIG. 4 in connection to the evaporator. Namely, if the ratio of the pitch P to the diameter D of the heat transmission pipe 35 is varied from 0.5 to 1.25, the heat transmission coefficient will be 1.1 times or more of that in a smooth pipe.
FIG. 8 graphically represents the relationship between the ratio of the pitch P of the groove 31 to the refrigerant dispensation pitch P1 and the ratio of the heat transmission coefficient. As shown, it has been found that if the ratio P/P1 is in the range of 0.6 to 1.4 (which means the pitch P of the groove 31 is 8 mm to 20 mm), the ratio of the heat transmission coefficient will be greater than 1.05, thereby improving the performance of the heat transmission pipe 35 (corrugated pipe) of the absorber. It has also been found that the heat transmission coefficient will reach the peak where the pitch P of the groove 31 of the heat transmission pipe 30 is approximately the same as the refrigerant dispensation pitch P1.
In operation of an absorption type refrigerating machine as arranged above, a gas burner 4 of an high temperature regenerator 5 burns and heats a diluted absorbent, such as aqueous solution of lithium bromide, flowing in from an absorber 3 to separate a refrigerant vapor from the diluted absorbent. The refrigerant vapor will flow through a refrigerant vapor pipe 13 to a low temperature regenerator 11. The low temperature regenerator 11 heats an intermediate absorbent from the high temperature regenerator 4 to provide a condensed refrigerant liquid which flows to a condenser 12. The condenser 12 condenses the refrigerant vapor flowing in from the low temperature regenerator 11, and flows it down to the evaporator 2 together with a refrigerant liquid flowing in from the low temperature regenerator 11. Within the evaporator 2, the refrigerant liquid will be dispensed by the operation of an refrigerant pump 18 onto an evaporator heat exchanger 21A. A cooling water which has been cooled to a low temperature in the evaporator heat exchanger 21A is then supplied to a load. The refrigerant vapor generated in the evaporator 2 will flow to the absorber 3 to be absorbed by a concentrated absorbent dispensed onto an absorber heat exchanger 29A.
An intermediate absorbent having an elevated temperature in which a refrigerant vapor has been separated in the high temperature regenerator 4 will flow via an intermediate absorbent pipe 22, a high temperature heat exchanger 8, another intermediate absorbent pipe 23 and a second absorbent pump 24 to the low temperature regenerator 11, into which the intermediate absorbent from the high temperature regenerator 4 will flow, accelerated by the second absorbent pump 24. The intermediate absorbent will then be heated by a heater 14 to separate a refrigerant vapor therefrom, further increasing its temperature.
A concentrated absorbent which has been heated and condensed in the low temperature regenerator 11 will flow into a concentrated absorbent pipe 25 and pass through a low temperature heat exchanger 7 and a concentrated absorbent pipe 26 to the absorber 3. It will then be dispensed from a dispenser 27 onto the absorber heat exchanger 29A.
While the absorption type refrigerating machine is operating as described above, a refrigerant falls dropwise from a dispenser 19 of the evaporator 2 onto heat transmission pipes 30. The refrigerant will then spread and flow smoothly over the outer surface of each heat transmission pipe 30 and will fall dropwise onto other heat transmission pipes 30 in a generally uniform fashion, during which part of the refrigerant flows along a groove 31 and falls downward. In addition, a cooling water running in each heat transmission pipe 30 will have a turbulence generated by a protrusion 32 to improve the heat transfer between the cooling water and the heat transmission pipe 30. Further, the refrigerant will fall dropwise also onto lower heat transmission pipes 30 in the evaporator 2 from the upper heat transmission pipes 30 in a generally uniform fashion so that wetting of the surfaces of the heat transmission pipes 30 may be secured.
In operation of the heat exchanger 29B of the condenser 12, a refrigerant vapor flowing from the low temperature regenerator 11 will be condensed on the outer surface of each heat transmission pipe 35. The refrigerant will flow downward along the outer surface of the heat transmission pipe 35 to fall dropwise from the lower end onto other heat transmission pipes 35 below, where the refrigerant on the outer surface of each pipe will gather in a groove 31 to drip downward. Thus, on the outer surface of the heat transmission pipe 35, instead of spreading, the refrigerant will flow and fall dropwise along the groove 31, thereby increasing the condensing area. In addition, a cooling water running in the heat transmission pipe 35 will have a turbulence generated by a protrusion 32, improving the heat transfer efficiency between the cooling water and the heat transmission pipe 35.
In the heat exchanger 29A of the absorber 3, a concentrated absorbent to be dispensed is cooled by a cooling water running in each heat transmission pipe 30 to facilitate the absorption of refrigerant vapor. The concentrated absorbent dispensed will then fall dropwise onto heat transmission pipes 30. The absorbent will flow downward over the outer surface of each heat transmission pipe 30 and fall dropwise from the lower end onto other heat transmission pipes 30 located below, where the absorbent on the outer surface of each pipe will drip downward along a groove. Thus, on the outer surface of the heat transmission pipe 30, the absorbent falls dropwise along the groove 31, not spreading, which will facilitate to prevent the refrigerant vapor which has once been absorbed by the absorbent from vaporizing again. In addition, the cooling water running in the heat transmission pipe 30 will have a turbulence generated by a protrusion 32, improving the heat transfer efficiency between the cooling water and the heat transmission pipes 30.
According the embodiment described above, since each heat transmission pipe 30 of the evaporator 2 has a groove which is predetermined as described above with respect to the ratio of the pitch to the outer diameter D, the depth and the width, when a refrigerant falls dropwise onto the heat transmission pipes 30, the refrigerant on the outer surface of each pipe will spread generally over the whole surface of the pipe instead of intensively flowing along a groove 31, enabling an improvement of the heat transfer between the refrigerant and the heat transmission pipes 30 as well as allowing the refrigerant to fall dropwise in a generally uniform fashion onto heat transmission pipes 30 located below. In addition, a cooling water running in each heat transmission pipe 30 will have a turbulence generated by a protrusion 32, improving the heat transfer between the cooling water and the heat transmission pipe 30, so that the heat exchange efficiency in the heat transmission pipe may be considerably improved. As a result, the performance of the evaporator 2 can be significantly improved, which allows to reduce the number of the heat transmission pipes 30 so that the evaporator 2 and, hence, the evaporator-absorber shell 1 may be downsized.
Further, when the outer surface of the heat transmission pipe 30 is polished, wettability will further be improved, and the heat exchange efficiency in the heat transmission pipe 30 can additionally be increased.
In addition, since each heat transmission pipe 35 of the condenser 12 is a corrugated pipe having a spiral groove 31 and a protrusion 32, a refrigerant which has condensed on the outer surface of the pipe will gather in and flow along the groove 31, which allows to prevent the refrigerant from spreading over the whole outer surface of the pipe and to secure a condensing area, especially on the heat transmission pipes 35 at a lower stage to which the refrigerant will fall dropwise. It is advisable that the pitch of the groove 31 of the heat transmission pipe 35 be smaller than that of the heat transmission pipe 30 so that the refrigerant will flow downward along the groove 31 instead of spreading over the outer surface of the pipe. Also, the cooling water will have a turbulence generated by a protrusion 32 formed on the inner surface of the heat transmission pipe 35, improving the heat transfer between the cooling water and the heat transmission pipes 35, so that the heat exchange efficiency in the heat transmission pipe 35 may be considerably improved. As a result, the performance of the condenser 12 can be significantly improved, which allows to reduce the number of the heat transmission pipes 35 so that the condenser 12 and, hence, the condenser-regenerator shell 10 may be downsized. Thereby, the absorption type refrigerating machine can be significantly downsized. Downsizing the absorption type refrigerating machine will also enable to reduce the volume of absorbent to be filled.
Moreover, since the heat exchanger 29A provided below the dispenser 27 of the absorber 3 is composed of a plurality of heat transmission pipes 30, each of which is a corrugated pipe formed similarly to the heat transmission pipe 30 for the evaporator 2, having generally the same depth, pitch and width of the groove as that of the heat transmission pipe 30, when the absorption type refrigerating machine is operating, it can prevent a concentrated absorbent dripped from the dispenser 27 from intensively flowing along the groove, which therefore allows the concentrated absorbent to flow generally over the whole surface of the pipe, increasing the heat transfer between the concentrated absorbent and the heat transmission pipe 30. Further, it will also absorb the refrigerant vapor from the evaporator 2 by the concentrated absorbent spread over the whole surface, which improves the absorbing capacity, and further, will enable the concentrated absorbent to fall dropwise in a generally uniform fashion onto the heat transmission pipes 30 located below. In addition, a cooling water running in the heat transmission pipes 30 will have a turbulence generated by a protrusion 32, which improves the heat transfer between the cooling water and the heat transmission pipe 30, so that the heat transfer efficiency in the heat transmission pipe 30 may be considerably improved. As a result, the performance of the absorber 3 can be significantly improved, which allows to reduce the number of the heat transmission pipes 30 so that the absorber 3 may be downsized. Thereby, not only the evaporator 2 and the condenser 12 described above, but the absorption type refrigerating machine can also be considerably downsized.
As described above, according to the first, second, third and fourth embodiments of the present invention, part of a refrigerant will flow along a groove and the remainder will spread generally over the whole surface of each heat transmission pipe, improving the heat transfer efficiency between the refrigerant and the heat transmission pipe. Also, due to a turbulent effect caused by a protrusion in each heat transmission pipe, the heat transfer efficiency between a cooling water and the heat transmission pipe will be improved. In addition, by providing the pitch of the groove at a predetermined dimension to the outer dimension of the pipe and the refrigerant dispensation pitch, mutually contradictory effects of spreading the refrigerant over the outer surface of the heat transmission pipe and of achieving a sufficient turbulent effect in the heat transmission pipe may coexist. The thermal efficiency in the heat transmission pipe will thereby be significantly improved so that the enhancement of the evaporator performance may be attained.
According to the second embodiment of the present invention, the refrigerant will not only flow along each groove, but can as well sufficiently spread off the groove, therefore, further increasing the heat transfer efficiency.
According to the third embodiment of the present invention, by providing the height of the protrusion provided on the inner surface of each heat transmission pipe at a predetermined dimension, a sufficient turbulent effect may be obtained, which increases the heat transfer efficiency between the cooling water and the heat transmission pipe to a sufficient level, while preventing the increase of a flow loss against the cooling water in the heat transmission pipe as well as avoiding the enlargement of units such as pumps.
According to the fourth embodiment of the present invention, wettability of the outer surface of each heat transmission pipe against the refrigerant can be improved, so that the heat transfer efficiency to the refrigerant in the heat transmission pipe may be increased.
According to the fifth embodiment of the present invention, the refrigerant condensed on the outer surface of each heat transmission pipe of the condenser may be prevented from spreading over the whole outer surface of the pipe, which allows to avoid the re-vaporization of the refrigerant, improving the condensing capacity. Also, since the heat transfer efficiency of the heat transmission pipe to the refrigerant can be improved, the heat transfer efficiency in the heat transmission pipe will also be improved, so that a performance enhancement of the condenser may be attained.
According to the sixth embodiment of the present invention, the concentrated absorbent dripped onto each heat transmission pipe of the absorber will spread over the whole surface along the groove formed on the outer surface of the heat transmission pipe, improving the heat transfer efficiency between the concentrated absorbent and the heat transmission pipe. Also, due to the protrusion corresponding to the groove, the cooling water in the heat transmission pipe will have a turbulence generated, which improves the heat transfer efficiency between the cooling water and the heat transmission pipe. Therefore, the heat exchange efficiency of the heat transmission pipe may be improved so that a performance enhancement of the condenser may be attained.
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An absorption type refrigerating machine comprising an evaporator, an absorber, a regenerator, and a condenser, all connected by piping to form a refrigerating cycle. The evaporator, condenser or absorber includes a plurality of heat transmission pipes accommodated therein and arranged generally in a horizontal direction. Each pipe has at least one continuity of protrusion on the inner surface thereof extending in an axial direction of the pipe in a spiral fashion and at least one continuity of groove corresponding to the continuity of protrusion formed on the outer surface of the pipe.
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FIELD OF THE INVENTION
[0001] The present invention contemplates a pharmacological composition comprising as an active ingredient oleanolic acid, for the prophylaxis and treatment of neurodegenerative diseases such as multiple sclerosis. The invention demonstrates the ability of this natural compound, present in the cuticle of olives and olive leaves, as well as in oils where these fractions have a significant presence (olive-pomace oil), to reduce markedly the clinical signs of experimental autoimmune encephalomyelitis, referred to herein as EAE. This action is associated with an increase of both weight and survival of experimental animals as well as a reduction of the inflammatory reaction and cerebrovascular permeability. It is therefore an object of this invention to provide a pharmaceutical and/or nutraceutical composition with applications for treating Multiple Sclerosis (hereafter MS).
BACKGROUND OF THE INVENTION
[0002] Multiple Sclerosis is an autoimmune, inflammatory and degenerative disease of the central nervous system (CNS) directed against myelin proteins of the brain and spinal cord. It is considered as one of the major neurological illness of young adults, but although more common in women, the severity of the disease is more pronounced in male carriers. MS is characterized by the presence of plaques or lesions of demyelination in the white matter of the CNS, resulting in an abnormal nerve conduction that mainly affects muscle control. Signs and symptoms vary widely, depending on the location of the lesions. Thus, i) motor symptoms may include speech impairment, weakness, tremors and difficulty walking, ii) sensory symptoms may include numbness, tingling, pain and visual disturbances and iii) the psychological symptoms can include changes in mood, and depression. In most patients, the disease occurs during or after a previous stage of relapses and remissions, while in a small percentage of patients (10-15%), the evolution of the disease is progressive from the beginning. The attacks lead to a continuous process of demyelination and remyelination, which causes scarring of nerve fibbers and a progressive disability. Although the exact cause of the disease is still unknown, several studies have supported the hypothesis of a viral aetiology, but none of the viruses studied has emerged as the causative agent searched. So, current theories suggest that the etiology of MS may be related to a combination of autoimmune, environmental and viral factors that act together with an underlying genetic predisposition.
[0003] Experimental autoimmune encephalomyelitis (EAE) induced in susceptible strains of animals provides the best available model for understanding events in MS and to test new drugs that could lead to novel therapies (Raine et al. Lab Invest. 1980, 43: 150-7). In this model, immunization of the CNS is achieved by injection with specific antigens (myelin basic protein, proteolipid protein or myelin/oligodendrocyte glycoprotein) and adjuvants, which induce a T cell-mediated attack on the brain and spinal cord (Pettinelli and McFarlin, J. Immunol. 1981, 127: 1420-1423). Thus, in the CNS of animals with EAE are observed perivascular and parenchymal inflammatory infiltrates consisting mainly of (CD8 + and CD4 + ) T cells, B cells and activated macrophages that have crossed the blood-brain barrier (BBB), due to alterations in its permeability. Subsequently, it takes place the activation of resident cells such as microglia and astrocytes (Schonrock L M. et al Neuropathol Appl Neurobiol. 1998, 24: 320-30). Depending on the species and/or animal strain as well as on the antigen used, the inflammatory lesions may be accompanied, or not, by areas of demyelination. One of the characteristic features of EAE is the progressive weight loss during the clinical phase of the disease, which is rapidly reverted when the animals recover (Ruuls et al, J. Immunology, 1996, 157:5721-5731). The recovery is also associated with the production of cytokines such as IL-10 and TGF-β (Kennedy et al., J. Immunol. 1992, 149:2496-2505).
[0004] The currently available treatments for multiple sclerosis are intended to suppress the immune-inflammatory component of the disease. At present, the disorder is treated symptomatically by administration of high-dose of glucocorticoids at the onset of acute neurological symptoms. However, due to the numerous and serious side effects of steroids, it is not possible to carry out continuous preventive therapy. Some patients also received immunosuppressive agents, although they are often poorly tolerated. Therefore it is necessary to identify new treatments for MS to resolve the above mentioned issues and to minimize or slow the progression of the disease.
[0005] Thus, pharmacological research is focused on finding novel therapeutic agents, and in recent years the plant kingdom is proving to be an excellent resource for finding these new compounds. Even, it have been developed several lines of research that seek to analyze the beneficial effects of natural compounds present in vegetables, in order to relate the composition of the diet with the development/modulation of immune-inflammatory diseases, to define possible nutritional therapeutic strategies. In this context, oleanolic acid is a pentacyclic triterpenoid of oleanane group frequently present in plants used in traditional medicine in different countries. It comes in the form of free acid or as triterpenoid saponins aglycones (Liu J., J Ethnopharmacol 1995, 49: 57-68), and has been isolated from various plant species, including Olea europaea.
[0006] The literature since 1906 (Canzoneri F., Gazz chim ital, 1906, 36:372) recognize that the oleanolic acid as a permanent constituent of olive leaves and fruits. In the olive tree, is mainly in leaves, green fruits, especially in the cuticle, and in the residual liquor from the dressing olives. It is also found in mature olives, olive oil and pomace oil.
[0007] There are numerous publications on the therapeutic properties of triterpenes and in particular there are multiple studies that collect the biological and pharmacological activities of the oleanolic acid. These include: hepatoprotective (Liu Y et al., Toxicology Letters 1998, 95: 77-85), inflammatory (Mañez S et al. Eur J Pharmacol. 1999, 334: 103-5; Marquez-Martin A et al. Cytokines 2006), antitumoral (R. Martin et al. Cancer Res 2007, 67: 3741-51, John M E et al. J Nutr. 2006, 136: 2553-7), anti-HIV (Zhu Y M et al., Bioorg Med Chem Lett. 2001, 11: 3115-8; Kashiwara Y et al., J Nat Prod 1998, 61: 1090-5), vasodilatory (R. Rodriguez-Rodriguez et al. Br J Nutr. 2004, 92: 635-42), hypoglycaemic (H. Sato et al. Biochem Biophys Res Commun. 2007, 362: 793-8, Yoshikawa M et al. Biofactors. 2000, 13: 231-7), and lipid lowering activities (BL Ma. Traditional Medicine and Pharmacology. 1986, 2: 28-29).
[0008] The present invention relates to the search for new treatments for MS and describes a new pharmacological application of the oleanolic acid, as an agent that markedly reduces the clinical and immuno-inflammatory hallmarks of the experimental autoimmune encephalomyelitis.
SUMMARY OF THE INVENTION
Brief Description
[0009] The present invention describes the use of a pentacyclic triterpene, on the development of drugs or pharmaceutical compositions and nutraceutical compositions for the prevention and/or treatment of neurodegenerative diseases, such as multiple sclerosis. More particularly, the compound of the present disclosure refers to the pentacyclic triterpene, oleanolic acid. (3β-hydroxyolean-12-en-28-oic acid).
[0000]
[0010] It is also part of the invention a pharmaceutical composition useful for the treatment of a neurodegenerative disease, preferably multiple sclerosis comprising a therapeutically effective amount of a pentacyclic triterpene, together with, optionally, one or more adjuvants and/or pharmaceutically acceptable vehicles.
[0011] In addition, a further aspect within the scope of the invention relates to a pharmaceutical composition in which the pentacyclic triterpene is oleanolic acid, and the use of the pharmaceutical composition to treat a human being affected by a neurodegenerative disorder, preferably multiple sclerosis, involving the administration of the therapeutic composition to reduce the progression of the disease.
DETAILED DESCRIPTION
[0012] This invention pertains to the use of a composition comprising oleanolic acid as the agent that reduces the clinical and the immuno-inflammatory signs observed in the experimental autoimmune encephalomyelitis induced in C57BL/6 mice (female 6-8 weeks of age), animal model of multiple sclerosis, and that in addition significantly delays the onset of the disease, in particular (see Example 1):
[0013] a) Daily ip administration of 6 mg/kg of oleanolic acid (OA1) decreases the severity of the disease, and
[0014] b) Daily ip administration of 6 mg/kg of oleanolic acid (OA2) delays the onset of EAE.
[0015] These actions are manifested through: i) amelioration neurological symptoms, ii) weight gain, iii) decrease of cellular and molecular extravasation, iv) decrease expression of key proteins in inflammatory processes, v) increased survival of EAE mice.
[0016] Therefore, the results suggest that this triterpene may have protective effects on the BBB integrity and on the inflammatory events related to the development of EAE, which could lead to an improvement of the clinical symptoms associated with MS, in the EAE model, as well as other neurodegenerative disorders. Furthermore, since this product is a natural substance that can be isolated from olives, this compound could be used as a supplement to the diet or in nutraceutical preparations.
[0017] Thus, an object of this invention is the use of a pentacyclic triterpene, from now on use of a compound of the present invention, in the development of pharmaceutical and nutraceutical compositions for the prevention and/or treatment of neurodegenerative diseases, preferably sclerosis multiple.
[0018] As used herein, the term pentacyclic triterpene refers to a member of this family of compounds belonging, for illustrative purposes and without limiting the scope of the invention, to the following group: oleanolic acid, maslinic acid and erythrodiol.
[0019] A particular object of this invention is the use of a compound of the invention in which the pentacyclic triterpene comes from the oleanane family, preferably oleanolic acid.
[0020] In this invention the term “the use of a pentacyclic triterpene” also includes the use of its isomeric forms, pharmaceutically acceptable salts and solvates, synthetic derivatives such as cyano, imidazole, amide, ester and ether derivatives of parent compounds. The pentacyclic triterpenes of the present invention can be isomers, including optical isomers or enantiomers. The use of its isomers, enantiomers as well as individual diastereoisomers and mixtures thereof, are also included in the present invention. The individual diastereoisomers and mixtures thereof can be separated by conventional techniques.
[0021] Also, within the scope of this invention is the use of prodrugs of pentacyclic triterpenes. The term “prodrug”, as used herein, includes any compound derived from a pentacyclic triterpene, for example, esters, including esters of carboxylic acids, esters of amino acids, phosphate esters, sulfonate esters, metal salts, etc., Carbamates, amides, cyanide derivatives, etc. which, when administered to an individual, is capable of providing, directly or indirectly, the pentacyclic triterpene in this individual. Advantageously, the derivative is a compound that increases the bioavailability of pentacyclic triterpene when administered to an individual, or that enhances the release of same in a biological compartment. The preparation of the prodrug can be carried out by conventional methods known by those experts in the art.
[0022] As used in this invention the term “neurodegenerative disease” refers to pathologies in which cell degeneration of the central nervous system and the immuno-inflammatory component play a crucial role, and refers more specifically, for illustrative purposes and without limiting the scope of the invention, to multiple sclerosis and Alzheimer's disease.
[0023] Accordingly, another particular object of this invention is the use of a compound of the invention in the preparation of pharmaceutical or nutraceutical compositions for the prevention and/or treatment of human neurodegenerative disorders including, for illustrative purposes and without limiting the scope of the invention, multiple sclerosis and Alzheimer's disease.
[0024] Another object of this invention is a pharmaceutical composition useful for the treatment of a neurodegenerative disease, hereafter “pharmaceutical composition of this invention”, comprising a therapeutically effective amount of a pentacyclic triterpene, together with, optionally, one or more adjuvants and or a pharmaceutically acceptable vehicles.
[0025] Yet another particular object of this invention is the pharmaceutical composition of the invention in which the pentacyclic triterpene belongs to the following group: oleanolic acid, maslinic acid and erythrodiol.
[0026] A further object of this invention is the pharmaceutical composition of the invention in which the pentacyclic triterpene is oleanolic acid.
[0027] In this disclosure, the term “pharmaceutically acceptable vehicle” refers to those substances, or combination of substances, known in the pharmaceutical industry, used in the preparation of pharmaceutical forms and includes adjuvants, solids or liquids, solvents surfactants, etc.
[0028] The pharmaceutical composition may also contain one or more therapeutic agents that will eventually enhance the therapeutic action of the pentacyclic triterpene compound or increase their spectrum of activity.
[0029] The pentacyclic triterpene compound will be present in the pharmaceutical composition in a therapeutically effective amount, i.e. in an appropriate amount to exert its therapeutic effect. In a particular embodiment, the pharmaceutical composition provided by this invention, contains between 0.01% and 99.99% by weight, of a pentacyclic triterpene compound and mixtures thereof, and may be available at any appropriate dispensation form according to the administration route chosen, eg oral, parenteral, intraperitoneal or topical. A review of the different pharmaceutical forms of drug administration and preparation procedures can be found, for example, in the Treaty of Galenic Pharmacy, C. Fauli i Trillo, 1st edition, 1993, Luzán 5, SA Editions.
[0030] Yet another object of this invention is the use of the pharmaceutical composition of the invention in the treatment of a human being affected by a neurodegenerative disease, hereafter, use of the pharmaceutical composition of the present invention, consisting on the administration of the therapeutic composition which reduces the progression of the disease, preferably multiple sclerosis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 : Effect on body weight (A), and on clinical signs (B) due to the progression of the disease effected by oleanolic injected daily after first symptoms. OA1
[0032] FIG. 2 : Effect on body weight (A), and on clinical signs (B) due to the progression of the disease effected by oleanolic injected daily after 7 days of immunization. OA2
[0033] FIG. 3 : Oleanolic acid diminished firm arrest (A) and rolling flux (B) of leukocytes on brain microvasculature, analyzed by intravital microscopy. C, healthy mice. EAE, induced-mice. EAE+OA1, induced-mice treated with OA at the onset of the clinical signs. EAE+OA2, induced-mice treated with OA from day 7 after immunization.
[0034] FIG. 4 : Changes in blood-brain barrier permeability of untreated- or OA treated EAE-mice. Evans blue dye was used as a measurement of plasma protein extravasation in (A) cerebral cortex, (B) cerebellum and (C) spinal cord 21-24 days post-immunization. C, healthy mice. EAE, induced-mice. EAE+OA1, induced-mice treated with OA at the onset of the clinical signs. EAE+OA2, induced-mice treated with OA from day 7 post-immunization.
[0035] FIG. 5 : Effect of OA on osteopontin (OPN) expression in CNS tissues: (A) cerebral cortex, (B) cerebellum and (C) spinal cord, of healthy and EAE mice, analyzed by commercial ELISA kits. C, healthy mice. EAE, induced-mice. EAE+OA1, induced-mice treated with OA at the onset of the clinical signs. EAE+OA2, induced-mice treated with OA from day 7 post-immunization
[0036] FIG. 6 : Survival enhancement of EAE mice due to effect of Oleanolic acid treatment, injected after first symptoms.
BRIEF DESCRIPTION OF THE EMBODIMENTS
Example 1
Oleanolic Acid Reduces Clinical Signs in EAE Mice
[0037] In the experiments we used fifteen animals per group. EAE was induced as described (Slavin A. Autoimmunity 1998, 28: 109) in C57BL mice by administration of a proteolipid protein. The immunization was carried out with 100 μg of a partial peptide of myelin/oligodendrocyte glycoprotein (MOG 33-55 ) in complete Freund's adjuvant containing 4 mg of Mycobacterium tuberculosis H37Ra in 1 ml. The mice were immunized by subcutaneous injection of this emulsion on day 0. In addition, on day 0 and 2, were administered intraperitoneally 300 ng/200 μl of Bordetella pertussis toxin. The administration of 6 mg/kg of oleanolic acid was performed intraperitoneally once a day, beginning:
[0038] 1.—12 days after induction of EAE, when clinical symptoms were detected, until the end of the experiment (21 days after induction) (OA1), and
[0039] 2.—after 7 days of induction of EAE, before the onset of the disease, until the end of the experiment (21 days after induction) (OA2).
[0040] Mice were examined, weighed and scored daily in a double-blind manner for signs of EAE. OA-treated EAE mice were compared with a group of EAE animals treated with placebo, with untreated control animals or control animals received the same daily dose oleanolic acid. In addition, a pathologic evaluation was performed to confirm the effect of improving the state of the disease. The weight of the mice in each group is represented in FIGS. 1 A and 2 A. The level of paralysis reached by each group of mice is shown in FIGS. 1 B and 2 B.
Evaluation of the Effect of Oleanolic Acid: Scores.
[0041] The effect of disease improvement (clinical effect) by the action of oleanolic acid is scored and evaluated with the pattern presented below.
[0042] Grade 0, no abnormality.
[0043] Grade 0.5, partial loss/reduced tail tone, assessed by inability to curl the distal end of the tail (Tail 50% or ⅔).
[0044] Grade 1.0, tail atony 100%
[0045] Grade 1.5, slightly/moderately clumsy gait, impaired righting ability, or combination.
[0046] Grade 2.0, hind limb weakness, partial (1 or 2)
[0047] Grade 2.5, partial (1 or 2) hind limb paralysis.
[0048] Grade 3, complete hind limb paralysis.
[0049] Grade 3.5, limb weakness.
[0050] Grade 4, tetraplegic. Complete limb paralysis
[0051] Grade 5, moribund state or death.
[0000] signs of paralysis started to develop around days 11-14 (tail atony and clumsy gait) following immunization, pointing to EAE induction;
[0052] In FIG. 1B , it is shown the evolution of the signs of paralysis of untreated EAE mice, compared with OA treated EAE mice. Mice treated with 6 mg/kg of the natural triterpene compound isolated from olive pomace oil, oleanolic acid, showed a significant improvement in clinical status of the disease compared with untreated EAE group. In addition, the severity of EAE was also significantly attenuated with prophylactic administration of oleanolic acid, as there was a delay in the onset of the disease ( FIG. 2B ). In both situations, the reduction of body weight was suppressed, showing a recovery ( FIG. 1A ) or preventive ( FIG. 2A ) effect.
[0053] Moreover, as mentioned above, in MS there is an infiltration of inflammatory cells into the CNS because of the breakdown of the blood-brain barrier, causing both cellular and molecular extravasation. These phenomena occur mainly in the venules where blood flow is lower. To study leukocyte-endothelial interactions that occur in vivo in the microcirculation (particularly the phenomena of leukocyte rolling and adhesion), intravital fluorescence microscopy was used. FIG. 3 shows the adherent (A) and rolling (B) leukocytes. EAE animals showed a significant increase of both parameters compared to healthy controls mice. In contrast, when the mice belonged to groups of protocol EAE+OA1 or protocol EAE+OA2, we observed a significant decrease in the flow of leukocytes rolling and adhering to the endothelium, compared with the untreated EAE group. Then, to characterize the changes in vascular permeability, Evans blue was injected intraperitoneally to the different groups of animals. FIG. 4 shows the leakage that occurs in the spinal cord, brain and cerebellum. Mice of protocol EAE+OA1 and protocol EAE+OA2 have a significantly reduced leakage in the CNS tissues studied, as compared to untreated EAE animals.
[0054] The analysis of key pro-inflammatory protein expression in EAE, lead us to study the presence and modulation of Osteopontin in CNS tissues. FIG. 5 shows that in all tissues studied, spinal cord, brain and cerebellum, the expression of this protein is increased in mice with EAE, when compared with healthy control mice. This increase was significantly reduced when mice were treated with oleanolic acid, following either protocol OA1 or OA1.
[0055] In terms of survival ( FIG. 6 ), was noted that in the placebo-treated EAE group, mice die within the first 40 days after disease induction. In contrast, when EAE mice receive oleanolic acid at the onset of symptoms, the animals did not die until 60 days post-induction.
Material and Methods.
Experimental Animals.
[0056] Mice were housed in the animal care facility at the School of Medicine of the University of Valladolid. Mice were fed with a special diet for laboratory animals, water ad libitum, temperature of 20-24° C. and exposed to a light cycle of 12 h/day (8.00 am-8.00 pm) (Council of European Communities, 1986). All experimental protocols were reviewed and approved by the Animal Ethics Committee of the School of Medicine, of the University of Valladolid.
Reagents
[0057] The following chemicals used in the experiments were provided by Sigma Chemical Co. (St. Louis, Mo., USA): Freud's complete adjuvant, M. tuberculosis H37 RA, B. pertussis toxin, rhodamine 6G and Evans Blue. The ELISA kit for detection of osteopontin was from IBL (Hamburg, Germany). The natural compound oleanolic acid was supplied by Cymit Quimica SL (Barcelona, Spain).
[0058] The pentacyclic triterpene, oleanolic acid was initially dissolved in dimethyl sulfoxide (DMSO) to prepare a stock solution of 10 −2 M. The subsequent dilutions of the triterpene were also carried out in DMSO. The final concentration of DMSO reached (less than 0.001%) did not significantly affect the results.
Induction of EAE
[0059] Chronic progressive EAE disease was induced in adult 8-10-wk-old female C57BL/J6 mice following the protocol described by (Slavin A. Autoimmunity 1998, 28:109-20). Mice were injected in the tail base bilaterally with an innoculum containing 100 μg of MOG peptide 35-55 emulsified in complete Freund's adjuvant containing 0.4 mg/ml Mycobacterium tuberculosis H37 RA. Then, i.p. injection 300 ng/animal of B. pertussis toxin was administered by two times with an interval of 48 hours. Mice were examined daily to monitor weight loss and the onset of neurological symptoms
Analysis of Osteopontin in the CNS.
[0060] Animals of the different experimental groups were sacrificed at day 21 post-immunization and CNS protein extracts (cerebral cortex, cerebellum and spinal cord) were prepared by homogenization in a solution: 0.4 M NaCl, 0.05% Tween 20, 0.5% BSA, 0.1 mM phenylmethylsulfonyl fluoride, 0.1 mM benzetonium chloride, 10 mM EDTA and 20 KI aprotinin (100 mg tissue/ml). The homogenate was centrifuged at 10,000 rpm for 10 min at 4° C. The concentration of osteopontin was determined in the supernatants by a commercial ELISA kit.
Intravital Microscopy in the Brains of Mice.
[0061] Intravital microscopy techniques allow the study of leukocyte-endothelium interactions. The leukocytes that interact with the endothelial surface can be visualized because their speed is markedly reduced, as compared to the average velocity of the blood flow in the venule. To make a precise study of leukocyte-endothelium interactions, we first made a record of the venule for one minute using a camcorder, and in a second time, a more detailed analysis was performed. The parameters of interest were the number of leukocytes adhering to the venular endothelium (number of leukocytes stationary for more than 30 seconds), and the number of rolling leukocytes (number of white cells per minute moving at a velocity less than that of erythrocytes).
[0062] The craniotomy was performed on the parietal zone. Animals received i.v. administration of rhodamine 6G (0.3 mg/kg body weight) to fix leucocytes. The fluorescence associated to rhodamine 6G was visualized at 510-560 nm by epi-ilumination. The microscope (20×) was used for observing micro-circulating events in brain. A digital camera coupled with a microscope displays the images on a monitor, which were recorded on video for further analysis of the leucocyte in rolling and adhesion.
Analysis of Extravasation Alterations
[0063] Evans blue dye is able to bind quantitatively to albumin, both in vivo and in vitro. This property has been widely used for quantification of protein extravasation as an index of increased vascular permeability and, indirectly, of tissue damage. The Evans Blue, once extravasated into the tissues, is removed from them, and then quantified by visible spectrophotometry.
[0064] Mice from all experimental groups were given 30 mg/kg of Evans Blue i.p. Then, the spinal cord, cerebrum and cerebellum was removed and washed in saline. The dye was extracted from the CNS tissues with formamide and the concentration was determined by measuring the absorvance at 620 nm. CNS tissue was dried 24 h at 60° C. and weighed. The extravasated dye was expressed as μg of Evans Blue/mg dried weight of the tissue.
Statistical Analyses
[0065] Data were treated using Mann-Whitney U test. Results are expressed as mean±SD; P values <0.05 were considered statistically significant.
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Oleanolic acid (3β-hiydroxyolean-12-en-28-oic acid) is a pentacyclic triterpene occurring in a large number of medicinal plants. The present invention is directed to the pharmacological application of the oleanolic acid, alone or in combination with other substances, in the treatment or prophylaxis of neurodegenerative diseases such as multiple sclerosis. The inventors have found that oleanolic acid, intraperitoneally administered once daily, reduces significantly the immuno-inflammatory and neurological symptoms associated with the experimental autoimmune encephalomyelitis, an experimental model of multiple sclerosis, delaying the onset and reducing the progression of the disease.
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BACKGROUND OF THE INVENTION
The invention relates to a dosing device for fluids used in infusion or transfusion systems comprising a flexible fluid line transversing a housing and a pressure element supported in the housing to compress the fluid line.
To perform infusions or transfusions, a reservoir containing the infusion or transfusion fluid and having a downwardly directed aperture, as well as a connected fluid line, is suspended as high as is considered necessary to ensure that the fluid pressure in the line is higher than the vein pressure of the patient. The fluid is delivered first to an intermediate container in the fluid line and then from there to the patient. Due to the different marginal conditions, e.g. the vein pressure of the patient, the viscosity of the fluid and the varying filling height of the fluid container and due to the fluid dosages determined therapeutically, it is necessary to accurately adjust the rate of flow of the fluid.
There have been known dosing means of the above mentioned type comprising a fluid line extending through a housing and a clamping element which consists of a roller guided in the housing and pressing on the hose cross section (DE-OS No. 26 37 495). The dosage amount usually determined by the number of fluid drops dripping per unit of time into the intermediate container cannot be kept constant for a long period with such a device because the PVC-hoses usually applied may deform due to their creep tendency (cold flow property). Problems will develop above all if the dosage amount needs to be increased leading to a longer compression of the fluid line than previously considered necessary, because the tough-elastic relaxation behavior present as a result of hysteresis of the plastic line inhibits a quick recovery of the original line cross section. Hence, even with constant adjustment a constant dosage cannot be realized with such dosing devices.
There has also been provided a dosing means comprising a housing and a substantially cylindrical valve chamber provided therein, with two connecting pieces having a respective channel and projecting radially from the housing or valve chamber in opposite directions, and a plug rotatable with a handle and sealingly disposed in the valve chamber. In the jacket surface of the plug, a passage is provided which when subjected to the rotary position of the plug admits, between the connecting pieces, flow cross sections of different dimensions. (DE-OS No. 27 35 955). Such dosing means are involved with a considerable constructional expenditure to ensure a safe sealing of the dosing means against air access.
Therefore, it is an object of the present invention to provide a fluid dosing means for infusion or transfusion devices which will overcome the above noted and other disadvantages.
It is another object of the present invention to provide a dosing means which permits an accurate, time-constant and reproducibly adjustable dosing of fluids.
SUMMARY OF THE INVENTION
The foregoing objects and others are accomplished in accordance with the present invention by providing a fluid line which contains inside a housing a hose or tubular element of highly flexible elastomeric material. The fluid line may be made of suitable plastics in the conventional manner. The elastomeric hose portion provided therein at a suitable site and surrounded by a housing forms in common with the latter, together with a pressure element and an adjusting means, the respective dosing unit. The hose portion has a high flexibility and restoring force thus imparting to the cross sectional face of the hose portion the tendency of returning to its original relaxed condition, this being controlled by the adjusting element, which is a pressing member in the instant case. A change in the position of the pressing element will cause an immediate change in the flow at the specific cross section of the hose portion, including the withdrawal of the pressing element. The resultant dosing accuracy is very high allowing the dripping rate of the fluid to be maintained substantially constant in time and reproducible by adjustment. The dosing means of the present invention ensures considerable air-tightness because the device controlling the flow, i.e. the hose portion in the instant case, is made of one piece. This is a very important safety feature with respect to intra-venous infusion and transfusion devices. The dosing means may also be produced at a reasonable price. The housing is an injection molded part made of one piece. Moreover, the housing, the adjusting means and the pressure element need not be sterilized because only the hose portion will come into contact with the infusion or transfusion fluid, so that the cost in regard to the sterilization of the dosing means and the risk of imperfect sterilization are avoided.
According to one preferred embodiment of the present invention, part of the longitudinal hose portion is thicker than the remaining portion with longitudinal displacement being protected against by the presence of the thicker part in the housing, with the pressure element engaging the hose portion outside the thicker region. Due to the shape of the hose portion, the position of the housing is exactly fixed. It is also quite advantageous that the hose portion can be readily obtained in the market as an injection molded part thus doing away with the need for special elements. In the dosing means of the present invention, the hose portion may be also used for the injection of additional medicaments or fluids by means of a syringe. The air-tightness of the dosing means is also ensured upon the puncturing and removing of a needle cannula because the hose or tubular portion is made of a highly flexible material. Due to the thicker part of the hose portion, a larger clearance in the cavity thereof is guaranteed when taking into consideration the depth of penetration of the needle cannula, thus increasing the safety of the device.
In accordance with the above discussion, it is apparent that the utility of the hose portion is of a dual nature. On the one hand, medicaments may be injected, preferably via the thicker portion, and on the other hand, in connection with the pressing element, the rate of flow of the infusion or transfusion fluid is reliably and accurately administered. These two objects have been achieved heretofore only with the use of two hose sections.
Another preferred embodiment of the present invention is characterized in that the pressing function is conducted by the pressing element transverse to the longitudinal direction of the hose portion and that the front side of the pressing element pressing against the hose portion is inclined relative to the direction of movement thereof. Due to such an asymmetrical deformation of the hose portion, the latter can be clamped successivey from one side thus preventing it from retaining a deformation in another cross sectional shape, in spite of its elasticity, e.g. in the form of an eight, or from changing its cross sectional shape suddenly. This ensures a particularly accurate, reproducibly adjustable dosage.
According to another embodiment, the present invention is characterized in that the housing includes a puncture channel for a needle cannula. By this means, the needle cannula is introduced at a specific location of the hose portion.
In another preferred embodiment, the invention is characterized in that the puncture cannula extends at an acute angle relative to the longitudinal axis of the hose portion to maintain the most favorable puncture angle in accordance with the guidance of the needle cannula. The injection will be effected more safely because a maximum free path is obtained for the point of the needle in the hose portion. This is important if, in cases of emergency, the injection must be made very quickly, because the needle point can be positioned more easily and more safely in the hose cross section and the second hose wall cannot be perforated by too deep a puncture, whereby the injection fluid would not get into the blood circulation.
Provided as an advantageous embodiment of the invention, the pressure element is movable via a manually adjustable, self-locking adjusting means which, preferably, may consist of a threaded spindle positioned in the housing. Subject to the thread pitch, the spindle allows for the injection of a particularly accurate and reproducible dosage. The adjusting means may be provided with a detachable handle portion to increase safety against incidental or undesired adjustment of the dosing means, because it cannot be set when the handle portion is removed.
The preferred embodiments of the present invention will now be explained in more detail with reference to the accompanying drawings which are intended to illustrate but not limit the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of a dosing means comprising a threaded spindle as an adjusting device;
FIG. 2 is a plan view of the dosing means of FIG. 1;
FIG. 3 is a sectional view along the line III--III of FIG. 1;
FIG. 4 is an exploded perspective view of the dosing means of FIG. 1 in which the housing halves are opened;
FIG. 5 is a longitudinal sectional view of a dosing means comprising an eccentric as an adjusting device;
FIG. 6 is a plan view of the dosing means of FIG. 5;
FIG. 7 is a sectional view along line VII--VII of FIG. 5;
FIG. 8 is an exploded perspective view of the dosing means of FIG. 5, the housing halves being open; and
FIG. 9 is a perspective view of a dosing means comprising a lever as an adjusting means, the housing halves being open.
DETAILED DESCRIPTION
The embodiments shown in FIGS. 1 to 9 relate to a dosing means provided in an infusion- or transfusion device. Therefore, the dosing means 1 in a fluid line 2 is disposed between an infusion container and a patient. It comprises a housing 3 to receive an adjusting device 4, a pressing element 5 and a hose portion 6 inserted into the fluid line 2.
The hose portion 6 is a injection valve of a highly-elastic elastomer which is normally interconnected in a pvc-fluid line 2 to permit injection, for instance, of medicaments by infusion or transfusion. To connect it to the conventional pvc-fluid line 2, the two ends of the flexible hose portion 6 tightly overlap the ends of the fluid conduit 2. It is also possible to use connecting pieces such as employed in conventional infusion devices. The central region of the hose portion 6 preferably contains a thicker part 65, both ends of which are formed as annular shoulders reduced to cylindrical hose sections 63 and 64 which are somewhat larger in cross section than the cross section of the fluid line 2. The thick part 65 fixes the position of the total dosing means 1 at a specific point in the fluid line 2. Moreover, the wall thickness may be reinforced accordingly. This is important if the hose portion 6, specifically the thicker portion 65, in the dosing means 1 is also used for injection purposes. The thicker part 65 ensures a free path as long as possible to the cavity 60 of the hose portion 6 for the puncture of a needle cannula (not shown). The highly elastic material of the hose portion 6 is responsible for the immediate closing of the puncture hole upon the piercing of the wall of the hose portion 6 by a needle cannula and upon the extraction of the needle cannula.
In a closed condition, the housing 3 forms a chamber 7 in which the hose portion 6 is incorporated. The chamber 7, substantially adapted to the outer contour of the hose portion 6, comprises within the region of the thin cylindrical hose portion 63 a neck 71 and within the region of the thin cylindrical hose portion 64 a channel 72 (FIGS. 3 and 4). The annular shoulders 61 and 62 of the hose portion 6 are adjacent to a wall of the chamber 7 thus fixing the position of the hose portion 6. A puncture channel 8 for guiding a needle cannula to chamber 7 extends through the housing 3 at an acute angle relative to its longitudinal axis. This puncture channel 8 ends directly ahead of the annular shoulder 61 which is formed by the stepped thicker part 65 of the hose portion 6.
The pressing element used in the embodiments of the dosing means 1 of FIGS. 1 to 8 is a square-shaped dosing wedge 5 which, at its broad side, is pressing in a straight guide path 32, extending perpendicular to the hose portion on the cylindrical hose section 64 shortly ahead of the annular shoulder 61 of the hose portion 6. The end face 51 of the dosing wedge 5 presses the hose section 64 towards the flat bottom surface of the channel 72. The face 51 extends obliquely to the bottom surface in the cross sectional plane of the hose portion 6. Thus, with the application of the dosing wedge 5, the hose portion will be progressively clamped from the one side.
The dosing wedge 5 is operated by an adjusting device or setting means 4, the return movement being performed by the elastic restoring force of the hose portion 6. As illustrated in FIGS. 1 to 4, the setting means 4 may consist of a threaded spindle 40 disposed in a thread 33 of the housing 3a and actuated by a setting wheel 41. With the advance of the threaded spindle 40, pressure is applied to the dosing wedge 5 which urges against the hose section 64. For example, a hexagonal part 42 of the setting wheel 41 may engage a respective recess 43 inside the threaded spindle 40. The positive connection being disengageable, a removal of the setting wheel 41 is possible to prevent e.g. an inadmissible shifting of the dosing means 1. A hollow cylinder 44 projecting from the setting wheel 41 coaxially with the hexagon 42 and being fitted into a respective hollow-cylindrical recess 34 of the housing portion 3a of housing 3 is intended to guide the setting wheel 41 and to inhibit breaking, by tilting, of the hexagon 42.
In the embodiments of FIGS. 5 to 8, the setting means 4 consists of an eccentric 45 secured to an eccentric shaft 46 which is held by the bearing 35 in the housing 3a, and which receives a key-portion 48 of the setting wheel 47 supported with the former in the housing 3a. The eccentric shaft 46 is connected positively and detachably to the setting wheel 47. That portion 49 which receives the key-portion 48 of the setting wheel 47 is of a square or hexagonal shape. Upon actuating the eccentric shaft 46 by means of the setting wheel 47, the dosing wedge 5 is adjusted subject to the angle position of the eccentric 45, the outer peripheral surface of which is pressing on the dosing wedge 5. Due to the flexibility of the hose portion 6 inside the hose section 64, the dosing wedge 5 is constantly urged against the outer peripheral surface of the eccentric 45. The setting means is also self-locking thus preventing the setting wheel 41 from being moved automatically. The other elements of the dosing means 1 correspond to the preceding embodiment.
According to the embodiment of FIG. 9, a short leg 91 of an angular lever 90, rather than the dosing wedge 5, presses on the hose portion 6, the lever 90 being hinged unilaterally with its long leg 92 at a pivot point of housing 3a so that the long leg 92 takes an inclined position relative to the housing wall 36 if the hose portion 6 is relaxed. Between the housing wall 36 and the long leg 92, a slide 93 is inserted. Part of the slide extending inside the housing 3 is supported at the housing wall 36 to press on the long leg 92 of lever 90. When moved away from the pivot point 97 of the lever 90, the slide 93 gradually presses like a wedge on the long leg 92 due to the inclination of the lever 90, while the nearly rectangularly bent short leg 91 of the lever 90 increasingly presses on the hose portion 6. The end side 98 of the short leg 91 of the lever acting on the hose portion 6 is chamfered transversely to the hose extension similarly to that of the dosing wedge 5 thus causing the gradual clamping from one side of the hose portion 6 if the lever 90 is swivelled to the closing position. The slide 93 is guided in a slot 37 in the upper housing wall 36, the inside 39 of which is corrugated, to obtain a self-locking of the setting means in association with the corrugated surface 95 of the slide portion 94 inside the housing 3. The upper part 96 of the slide 93 may be also removable in accordance with the setting wheels 41 and 47 of the preceding embodiments so as to avoid an inadmissible actuation of the dosing means by unauthorized persons.
The housing is an injection molding made of one piece, e.g. of polypropylene. All of the illustrated housings are so designed that they contain two elements 3a and 3b (FIGS. 4, 8 and 9) pivotable for example about a film hinge 30. The two housing elements 3a and 3b may be mutually arrested by compression with the aid of snap locks 31a and 31b. Upon the compression of the two housing elements 3a and 3b, the junction cannot be released without being destructive. Both housing members include a handle portion 38 extending in parallel to the fluid line 2 and permitting the singlehanded operation of the setting means 4 in combination with a setting wheel 41 and/or 47 or a slide 93. The outer contour of the setting wheels 41 and 47 or of the slide 93 is shaped so as to allow an easy handling with one thumb while the other fingers of the hand are gripping the handle portion 38 of the housing 3.
Although the above specification refers to a hose portion 6 having a thicker part 65, it is possible to use a normal flexible hose without a thickening, the connection with the pvc fluid line 2 being established by connecting pieces.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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The invention relates to a dosing device for fluids used in infusion or transfusion systems comprising a flexible fluid line transversing a housing to compress the fluid line. The device comprises a housing and an elastomeric tubular element having leading and trailing sections which traverses said housing to interconnect respective ends of said fluid line. The tubular element comprises a thicker portion between the leading and trailing sections whereby the thicker portion protects against longitudinal displacement of the housing. A pressing element engages the tubular element outside the region of the thicker portion.
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CLAIM FOR PRIORITY
[0001] This non-provisional application claims the benefit of the filing date of U.S. Provisional Patent Application Serial No. 60/180,348, of the same title, filed Feb. 4, 2000.
TECHNICAL FIELD
[0002] The present invention relates generally to papermaking fiber processing and more particularly to a method and apparatus useful for cleaning secondary pulp by way of a multistage forward cleaner system with an integrated flotation cell which cooperates with the forward cleaners to boost efficiency of the system.
BACKGROUND
[0003] Processing of papermaking fibers to remove contaminants is well known in the art, including the use of forward cleaners and flotation cells. Such technology is used, for example, to treat secondary (recycle) fiber sources for re-use in paper products such as towel and tissue, paperboard, coated writing and printing papers and so forth. Following is a brief synopsis of some patents of general interest.
[0004] According to U.S. Pat. No. 4,272,315 to Espenmiller waste paper containing materials, e.g., commercial “waste paper”, are treated for recovery of reusable paper therefrom by slushing in a pulper from which two fractions are continuously extracted—a first fraction through small holes, e.g. {fraction (3/16)} inch in diameter, and a second fraction through substantially larger holes, e.g., 1 inch in diameter. The second fraction is screened, preferably after a centrifugal cleaning operation, in a screen having small perforations sized to accept only substantially defibered paper, and the accepts flow is mixed directly with the first extracted fraction. The reject flow from this screen is conducted, with or without an intermediate deflaking operation, to a tailing screen from which the accepts are recycled to the pulper and the rejects are eliminated from the system. Advantages of this method and system include the continuous elimination of plastic and other floating trash from the pulper, a high degree of essentially complete defibering in the pulper, and minimal recycling of adequately defibered stock.
[0005] U.S. Pat. No. 4,983,258 to Maxham discloses a process for the production of papermaking fiber or pulp from waste solids emanating from pulp and paper mills, particularly waste solids in process water streams containing fibrous solids that cannot be directly recycled by paper mill “saveall” devices, from pulp and paper mill process water streams conveyed by the sewerage system to wastewater treatment plant facilities, and from “sludge” emanating from the underflow of a primary clarifier or sedimentation basin at pulp and paper mill wastewater treatment facilities either before or after the “sludge” is thickened and dewatered. The said process comprises a defibering stage to release individual fibers from bundles, a screening stage to separate long fiber and debris from short fiber and clay, a centrifugal cleaning stage to separate debris from the long fiber, a bleaching stage to increase the brightness of the fiber, a dewatering stage to remove excess water from the pulp, a sedimentation stage to separate the short fiber-clay-debris from the defibering effluent which is substantially recycled, and a biological treatment process to remove dissolved organic materials from the excess water generated which can be either discharged from the process or recycled as process water.
[0006] U.S. Pat. No. 5,240,621 to Elonen et al. discloses a method of separating an aqueous solids containing suspension which includes (a) subjecting a first solids containing suspension to centrifugal forces so as to separate the suspension into a first gas containing flow, a second gas-free flow and a third flow; (b) feeding the third flow into a flotation cell having a bottom; (c) introducing air at the bottom of the flotation cell into the third flow for separating from the third flow a fourth partial flow; (d) withdrawing the air containing third flow after the separation of the fourth partial flow from the flotation cell; and (e) subjecting the third flow to the centrifugal forces of step (a). An apparatus for the separation of gas and lightweight material from a gas and lightweight material containing aqueous solids suspension is also described and includes a centrifugal pump for separating the gas and lightweight material from the solids suspension with a suspension inlet and an outlet for the lightweight material; a flotation cell for separating the lightweight material from a solids suspension; and a circulation loop connecting the outlet of the centrifugal pump, the flotation cell and the suspension inlet of the pump.
[0007] In U.S. Pat. No. 5,693,222 to Galvan et al. a dissolved gas flotation tank system is disclosed which is configured to provide educted gas or air into recirculated effluent fluid from the tank which includes a pump system which increases the dissolution rate of gas into the effluent fluid thereby eliminating the need for retention tanks and related equipment which adds to high equipment costs. The dissolved gas flotation tank system also provides a pre-contact chamber for assuring immediate and intimate contact between the suspended solids in an influent feed stream and the recirculated effluent fluid in which gas is dissolved, as well as flocculant when used, to produce a better agglomerate structure for improved flotation and separation. The dissolved gas flotation tank also provides an improved means of removing and processing float from the tank, and employs a dewatering system enhanced by the addition of chemicals or flocculants into the float removal system.
[0008] The disclosures of the foregoing patents are hereby incorporated for reference.
[0009] While flotation and separation technologies are fairly advanced, there is an ongoing need to increase overall fiber-cleaning system performance and to reduce the amount of waste and capital investment in the plant.
SUMMARY OF INVENTION
[0010] The present invention provides a hybrid system for processing papermaking fibers and includes a multistage array of forward cleaners coupled with a flotation cell which increases overall efficiency of the system. In a typical embodiment, a first rejects aqueous stream from a first stage bank of centrifugal cleaners is treated in a flotation cell before being fed to a second stage bank of centrifugal cleaners.
[0011] One advantage of feeding the second accepts stream forward is that it does not have to be returned to the first bank of cleaners for re-cleaning. This reduces the size of the first bank of cleaners or allows an existing installation to operate at a lower consistency. (The cleaners operate more efficiently at a low consistency of 0.5% than at 0.8 or 1%). Another advantage is that the flotation cell operates at greater than 60% efficiency on removing hydrophobic contaminants from the first cleaner rejects, while another cleaner stage removes less than 50% of the hydrophobic contaminants. As a result a large quantity of hydrophobic contaminants are removed in the flotation stage, which makes the remaining cleaner stages work more efficiently with less good fiber loss.
[0012] Investigation showed that the number of hydrophobic contaminants in the second cleaner accepts after the flotation stage was lower than the number of hydrophobic contaminants in the first cleaner accepts. Without the flotation stage the number of hydrophobic contaminants in the second accepts is much higher than the first accepts, so that the second accepts have to be returned to the first bank of cleaners for more cleaning.
[0013] As will be appreciated form the discussion which follows, the size and cost of a flotation stage for treating secondary fiber can be reduced by up to 75% if it is installed in centrifugal cleaner system as compared to a full scale treatment of the stock by flotation. The centrifugal cleaner system modeling indicates a 34% reduction in ink speck area of total centrifugal cleaner system accepts by removing ink specks from the first stage rejects with 80% efficiency in a flotation stage and then feeding the flotation accepts forward after centrifugal cleaning of the second stage. (24% reduction if second stage rejects are treated in a similar manner). The ability to feed the centrifugal cleaner rejects forward (after the flotation stage and additional centrifugal cleaning in the next stage) reduces the stock consistency in the first stage, thereby improving the efficiency of the first stage. The capacity of the system is also increased by feeding the second stage centrifugal cleaner accepts forward. The other centrifugal cleaner stages can also be operated more efficiently since more than 50% of the ink in the first stage centrifugal cleaner rejects has been removed in the flotation stage. When the centrifugal cleaner accepts are thickened in a press, a large amount of ink ends up in the pressate. This ink can also be removed by using the ink-laden pressate as dilution water for the centrifugal cleaner rejects going to the flotation stage.
[0014] A conventional centrifugal cleaner system (as shown in FIG. 1) normally consists of several stages, whereby the rejects of each centrifugal cleaner stage are diluted for cleaning in the next stage and the centrifugal cleaner accepts are fed backwards to the feed of the previous stage. The ink speck removal efficiency of the centrifugal cleaner is usually much less than 50% on toner inks in office waste paper. As a result the total centrifugal cleaner system ink speck removal efficiency can drop to 30% or less on a furnish containing a large proportion of office waste.
[0015] By sending the first or second stage centrifugal cleaner rejects to a flotation stage (as shown in FIG. 2) it is possible to remove a much higher percentage of the ink specks in office waste. (It was possible to obtain 80% removal of ink specks during a pilot plant trial with a flotation cell operated on second stage centrifugal cleaner rejects.) If the accepts of the flotation cell are cleaned in the next centrifugal cleaner stage, the centrifugal cleaner accepts from that stage can then be fed forward to the thickener. Sending centrifugal cleaner accepts forward reduces the load and improves the efficiency of the previous centrifugal cleaner stage.
[0016] The present invention is particularly useful in connection with removing stickies from the recycle fiber product stream; likewise, it is believed pitch removal is enhanced. Stickies are generally a diverse mixture of polymeric organic materials which can stick on wires, felts or other parts of paper machines, or show on the sheet as “dirt spots”. The sources of stickies may be pressure-sensitive adhesives, hot melts, waxes, latexes, binders for coatings, wet strength resins, or any of a multitude of additives that might be contained in recycled paper. The term “pitch” normally refers to deposits composed of organic compounds which are derived form natural wood extractives, their salts, coating binders, sizing agents, and defoaming chemicals existing in the pulp. Although there are some discrete characteristics, there are common characteristics between stickies and pitch, such as hydrophobicity, low surface energy, deformability, tackiness, and the potential to cause problems with deposition, quality, and efficiency in the process. Indeed, it is possible with the present invention to reduce stickies by 50%, 80% or even more by employing a flotation cell in a multistage forward cleaner system as hereinafter described in detail.
[0017] The rejects from the flotation stage are so full of ink and ash that they can be rejected without any further treatment.
[0018] There is provided in one aspect of the present invention, a method of processing papermaking fibers with a multistage array of forward cleaners including a plurality of centrifugal cleaners configured to generate accepts streams and rejects streams which concentrate heavy waste, the method including (a) feeding a first aqueous feed stream including papermaking fibers to a first stage bank of centrifugal cleaners of the multistage array; (b) generating a first accepts aqueous stream and a first rejects aqueous stream in the first stage bank of centrifugal cleaners, the first aqueous rejects stream being enriched in heavy waste with respect to said first aqueous feed stream; (c) supplying the first rejects aqueous stream to a flotation stage; (d) treating the first rejects aqueous stream in the flotation stage to remove hydrophobic waste from the first aqueous rejects stream and produce an intermediate aqueous purified feed stream; and (e) feeding the aqueous purified intermediate feed stream to a second stage bank of centrifugal cleaners of the multistage array, the second centrifugal cleaner being configured to generate a second accepts aqueous stream, wherein the second rejects aqueous stream is enriched in heavy waste with respect to said aqueous purified intermediate feed stream. The method may further include feeding the first accepts aqueous stream and said second accepts aqueous stream to another cleaning device or a thickening device. Suitable additional cleaning devices include screening devices, reverse cleaners and the like. In a preferred embodiment, the first aqueous feed stream comprises a preliminary accepts stream generated by way of a preliminary bank of centrifugal cleaners dividing a preliminary feed stream into a preliminary accepts stream and a preliminary rejects stream. A preferred method may include feeding the preliminary rejects stream to the flotation stage and treating the preliminary rejects stream along with the first rejects aqueous stream to remove hydrophobic waste therefrom whereby the aqueous purified intermediate stream includes treated components from both the preliminary rejects stream and the first rejects aqueous stream.
[0019] In other preferred embodiments, the process may include feeding the second rejects aqueous stream to a third centrifugal cleaner operative to generate a third accepts aqueous stream and a third rejects aqueous stream.
[0020] Preferably, the multistage array of forward cleaners comprises at least 3 banks of centrifugal cleaners, and still more preferably, the multistage array of forward cleaners comprises at least 5 banks of centrifugal cleaners. The first aqueous feed stream generally has a consistency of from about 0.3% to about 0.9%, whereas the first aqueous stream more typically has a consistency of from about 0.4% to about 0.7%. The hydrophobic waste removed from the first aqueous stream by the flotation stage often includes an ink and stickies composition, toner ink compositions being typical in office waste and stickies compositions frequently being obtained from pressure sensitive adhesives in office waste.
[0021] In another aspect of the invention there is provided a hybrid apparatus for processing papermaking fibers with a multistage array of forward cleaners including (a) a first bank of centrifugal cleaners configured to generate a first accepts stream and a first rejects stream upon operating on a first aqueous feed stream, the first rejects stream being enriched with respect to heavy hydrophobic contaminants with respect to the first aqueous feed stream; (b) a flotation cell connected to the first bank of centrifugal cleaners so as to receive the first rejects stream and adapted to remove hydrophobic contaminants such as ink, stickies and the like from the first rejects stream, the flotation cell being constructed and arranged so as to generate a flotation rejects stream and a flotation accepts stream which is purified with respect to hydrophobic contaminants in said first rejects stream; and (c) a second bank of centrifugal cleaners coupled to the flotation cell so as to receive the flotation accepts stream as a second feed stream, the second bank of centrifugal cleaners being likewise configured to generate an accepts stream hereinafter referred to as a second accepts stream and a second rejects stream respectively. In a preferred embodiment, a preliminary bank of centrifugal cleaners is provided upstream of the first bank of centrifugal cleaners and coupled thereto whereby the accepts stream of the preliminary bank of centrifugal cleaners is fed to the first bank of centrifugal cleaners. The banks of centrifugal cleaners are typically hydrocyclone type cleaners.
[0022] Unless otherwise indicated, terminology appearing herein is given its ordinary meaning; %, percent or the like refers, for example, to weight percent and “consistency” refers to weight percent fiber or solids as that term is used in papermaking.
BRIEF DESCRIPTION OF DRAWINGS
[0023] The invention is described in detail below with reference to numerous examples and the appended Figures wherein like numbers designate similar parts throughout and wherein:
[0024] [0024]FIG. 1 is a schematic of a conventional multistage forward centrifugal cleaner system wherein each bank of cleaners are designated by a conical element;
[0025] [0025]FIG. 2 is a schematic diagram of a hybrid multistage forward cleaner/flotation apparatus and process of the present invention, wherein a flotation stage is provided to treat the second stage rejects stream;
[0026] [0026]FIG. 3 is a schematic diagram of a hybrid multistage forward cleaner/flotation apparatus and process of the present invention wherein a flotation stage is provided to treat the first stage rejects stream;
[0027] [0027]FIG. 4 is a schematic diagram of a hybrid multistage forward cleaner/flotation apparatus and process of the present invention wherein a flotation stage is provided to treat the first stage rejects and third stage accepts; and
[0028] [0028]FIG. 5 is a schematic diagram illustrating an apparatus and process of the present invention wherein the hybrid system has dual forward cleaner banks in series and the rejects stream from both of the forward cleaner banks are provided to a flotation cell.
DETAILED DESCRIPTION
[0029] The invention is described in detail below for purposes of illustration and exemplification only. Such explanation of particular embodiments in no way limits the scope of the invention which is defined in the appended claims. Referring to FIG. 1, there is shown a conventional forward cleaner system 10 of the type employed at a paper mill, for instance, as part of the cleaning process for processing secondary pulp into paper products. System 10 has five stages 12 , 14 , 16 , 18 and 20 of banks of centrifugal cleaners interconnected in the manner shown. Such connections may include suitable piping, mixing tanks, holding vessels and the like (not shown) as may be convenient for operating the system. Pulp is fed at low consistency to the system at 22 to the first bank of cleaners 12 through inlet 24 and centrifugally treated in the first stage by a bank of hydrocyclones, for example, such that the accepts are fed forward at 26 to a thickener (or another cleaning device) at 28 whereas the rejects, concentrating the heavy, hydrophobic waste in the system are fed to second stage 14 at 28 for further treatment in a second stage made up of a second bank of centrifugal cleaners 14 . Diluent water is added to the rejects stream from the first stage as indicated at 30 in an amount suitable for the particular system or operating conditions. Stream 28 (first stage rejects) is thus fed to the second stage cleaners whereupon bank 14 of cleaners generates an accepts stream 32 and a rejects stream 34 . Stream 32 is a recycled to the feed 22 and makes up a portion of the material fed to the first stage bank of cleaners 12 . The first bank of cleaners may be made up of 50 or more hydrocyclones depending on capacity and performance desired. Subsequent stages will each contain fewer cleaners than the previous stage depending upon the amount of rejects, until the final stage contains less than 10 cleaners.
[0030] Stream 34 is again enriched with respect to heavy components (with respect to stream 32 ) and is fed to the third stage 16 bank of cleaners for further processing. Diluent water may again be added at 36 if so desired to stream 34 . Stage 16 generates another accepts stream 38 which is fed back to the second stage (stream 28 ) and another rejects stream 40 enriched in heavy hydrophobic components.
[0031] In like fashion, stream 40 is fed to the fourth stage 18 bank of cleaners at 42 where diluent water may again be added. The fourth stage generates another accepts stream 44 and another rejects stream 46 . These streams have the rejects/accepts characteristics noted above.
[0032] Stream 46 is fed to yet another stage 20 of forward cleaners at 48 wherein stream 46 is divided into an accepts stream 50 and a rejects stream 52 as indicated on the diagram. Accepts stream 50 is recycled to the fourth stage as shown and rejects stream 52 is discarded or further processed if so desired. There is thus described a conventional forward cleaner system utilizing centrifugal cleaners in cascaded/refluxing fashion to concentrate the waste material and purify the pulp which is fed forward at a papermaking process to a thickening device or a cleaning device such as screens or a reverse cleaner.
[0033] In accordance with the present invention, a flotation stage is advantageously integrated into a multistage forward cleaner system to remove hydrophobic material and increase the cleaning efficiency. Flotation utilizes the phenomenon that the minerals which are present in the ground ore can partially be wetted, i.e., they are hydrophilic, while other parts of the minerals are hydrophobic. Hydrophobic particles have a clear affinity to air. Accordingly, finely distributed air is introduced into the solid-water-mixture so that the air will attach to the hydrophobic particles causing them to rise to the surface of the mixture or suspension. The hydrophobic particles, such as valuable minerals or the above-mentioned contaminants present in repulped stock suspensions, collect as froth at the surface of the suspension and are skimmed off with a suitable means such as a paddle or weir. The hydrophilic particles of the ore or stock suspension remain in the flotation vat. It is also possible to separate two or more useful minerals selectively by the flotation method, for example, in the separation of sulfidic lead/zinc ores. For controlling the surface properties of the minerals small amounts of additives of chemical agents are introduced such as, for example, foaming agents which will help to stabilize the air bubbles, so-called collecting agents which actually cause the hydrophobic effect and prepare the mineral particles for attachment to the air bubbles, and floating agents which temporarily impart hydrophilic properties to the hydrophobic minerals and later return the hydrophobic properties for selective flotation, as mentioned above. The latter are generally inorganic compounds, mostly salts, while the collectors are mostly synthetic organic compounds, and the foaming agents are oily or soapy chemicals such as fatty acid soap.
[0034] The apparatus of the present invention may utilize a variety of readily available components. The centrifugal cleaners, for example, are available from Ahlstrom (Noormarkku, Finland) or Celleco (Model 270 series) (Lawrenceville, Ga., USA) and are arranged in banks as shown in FIGS. 2 - 5 . The flotation stage, which may be multiple cells, are likewise readily available from Comer SpA (Vicenza, Italy). Comer Cybercel® models FCB1, FCB3 and FCB4 are suitable as discussed further herein.
[0035] There is illustrated in FIG. 2 an apparatus 100 and method in accordance with the present invention. Apparatus 100 operates similarly to apparatus 10 in FIG. 1. Like ports are given like numbers for purposes of brevity and only differences noted from the discussion above. The system 100 of FIG. 2 operates as described in connection with system 10 of FIG. 1 and is so numbered in the drawing except that system 100 has a flotation stage 75 for treating the rejects stream 34 of second stage cleaner 14 . Diluent water may be added at 36 as before, and hereafter, stream 34 is treated in the flotation stage to remove hydrophobic material. The accepts from the flotation stage, that is purified as shown by removing hydrophobic waste from stream 34 , is then fed in stream 34 ′ to third stage cleaner 16 . Instead of refluxing the accepts from the third stage back to the second stage, the accepts material is fed forward in a product stream 26 ′ for downstream processing. The hydrophobic rejects ( 31 ′) from flotation stage ( 75 ) are removed from system 100 .
[0036] In FIG. 3 there is illustrated another apparatus 200 and method of the present invention. Here again similar functioning parts are numbered as in FIGS. 1 and 2, the discussion of which is incorporated by reference here. Apparatus 200 of FIG. 3 differs from apparatus 10 of FIG. 1 in that a flotation stage 75 is added to treat the first stage rejects stream 28 to remove hydrophilic waste to produce an intermediate purified stream 28 ′ which is fed to the second stage bank of cleaners 14 . Bank 14 generates a purified accepts stream 32 ′ which is fed forward to the thickening or other device 28 along with stream 26 . The hydrophobic rejects ( 21 ′) from flotation stage ( 75 ) are removed from system 200 .
[0037] In FIGS. 4 and 5 there are illustrated alternate embodiments of the present invention. Like components are numbered as in FIGS. 1 - 3 above, the discussion of which is incorporated by reference. In the apparatus 300 of FIG. 4, there is provided a flotation cell 75 which treats rejects stream 28 from the first centrifugal cleaning stage along with accepts stream 38 ′ from the third centrifugal cleaning stage. Stream 38 ′ is combined with rejects stream 28 and fed to the flotation stage where hydrophobic material is removed and an intermediate purified stream 28 ′ is produced. Stream 28 ′ is fed to the second stage 14 of centrifugal cleaners. The accepts stream from stage 14 is fed forward as stream 32 ″ and combined with stream 26 in thickening device 28 . The hydrophobic rejects ( 21 ′) from flotation stage ( 75 ) are removed from system 300 .
[0038] Apparatus 400 of FIG. 5 resembles apparatus 200 of FIG. 3 except that there is provided a preliminary stage 12 ′ of centrifugal cleaners, the accepts stream 26 ″ of which is utilized as the feed to stage 12 . Rejects stream 28 ″ of stage 12 ′ is combined with rejects stream 28 of stage 12 and fed to flotation stage 75 . Accepts stream 32 ′ of the second stage cleaners is fed forward with accepts stream 26 of stage 12 . The hydrophobic rejects ( 21 ′) from flotation stage ( 75 ) are removed from system 400 .
EXAMPLES
[0039] Pilot plant trials showed that flotation cells such as the Comer Cybercel ® can successfully deink secondary centrifugal cleaner rejects, with better results obtained if the consistency is kept close to 0.6%. Consistency refers to weight percent fiber or associated solids such as ash unless the context indicates otherwise. Results on 42% office waste (Grade A) and 100% office waste (Grade B) are shown in Table 1.
TABLE 1 Pilot Plant Results for Brightness Gain, Dirt + Ash Removal Efficiency on Grades A and B at Halsey and Results Used in Simulation Models Grade: A B Model Consistency: 0.69% 0.90% 0.62% Brightness Gain: 18.5% 5.3% Dirt Removal: 77-89% 65-87% 80% Ash removal: 63% 64% 64%
[0040] A simulation model was used to calculate the impact of a Comer Cybercel® flotation cell to deink forward cleaner rejects on solids loss, ash removal and on removal efficiency of mid-dirt (>150 microns) from a 1 st washer to the deinked pulp (while running grade B at 336 tpd at the 1 st washer):
TABLE 2 Impact of Flotation Cell on Solids Loss, Ash Loss, and Mid-dirt Removal Efficiency (according to the Simulation Model for 6 different configurations on Grade B) Example Solids loss Ash loss Mid-dirt Eff. 1 No Flotation cell 8.9 tpd 0.8 tpd 96.1% 2 Flotation cell on 2 nd 2.7 tpd 0.9 tpd 97.0% stage Rejects 3 Flotation cell on 6.7 tpd 1.9 tpd 97.4% 1 st stage Rejects 4 As 3 with 50% eff. in 6.7 tpd 1.9 tpd 97.7% 1 st stage 5 Flotation cell on 1 st 8.9 tpd 1.9 tpd 97.7% stage Rejects + 3 rd stage accepts, 44% eff. in 1 st stage 6 Flotation cell on two 11.8 tpd 2.8 tpd 98.5% 1 st stages
[0041] The following indicators were used to evaluate the performance of the pilot plant:
[0042] feed consistency.
[0043] brightness gain of handsheets from accepts compared to feed.
[0044] Dirt removal efficiency of small dirt (<150 microns), mid-dirt (>150 microns) and large dirt (>200 microns).
[0045] Ash removal efficiency.
[0046] The results in Table 3 below for examples 7-14 (duplicate runs) show that even at 0.90% feed consistency it was possible to obtain 5.3% points brightness gain, 73% mid-dirt removal efficiency and 64% ash removal on Grade B. Operating the flotation cell at 0.69% consistency on Grade A, it was possible to obtain 8.1% points brightness gain, 79% mid-dirt removal efficiency and 63% ash removal.
TABLE 3 Comer Pilot Plant Results on 2 nd stage Cleaner Rejects Feed Brightness Dirt + Ash Removal % Example Anal. Cons. % Ash % Gain Small Mid Large Ash Comments Grade B 7 1 0.86 3.3 88 71 64 2 4.4% 5.8 87 74 65 59 Accepts = 90% > 200 m. 8 1 0.88 5.4 87 74 67 2 3.9% 4.6 86 69 57 52 Accepts = 99% > 200 m. 9 1 0.88 6.3 88 78 74 2 5.9% 5.0 87 73 66 68 10 1 0.98 5.9 89 74 61 3.8% 5.7 86 69 63 77 Average 0.90 4.5% 5.3 87 73 65 64 Grade A 11 1 0.53 7.3 . . . 2 15.9% 9.4 92 78 72 Accepts = 95% > 200 m. 12 1 0.83 4.2 88 70 60 70 2 17.8% 8.2 87 70 64 Accepts = 90% > 200 m. 13 1 0.70 8.6 89 88 92 53 2 16.5% 8.0 89 80 80 Accepts = 74% > 200 m. 14 1 — 8.7 91 85 87 67 2 23.8% 10.4 89 85 85 Average 0.69 18.5% 8.1 89 79 77 63
[0047] The effect of incorporating a flotation stage in accordance with the present invention into a multistage forward cleaner system was evaluated with a computer model with respect to the systems illustrated in FIGS. 1 - 5 . Results are summarized in the tables below. DIP refers to deinked pulp and DRE refers to dirt removal efficiency.
TABLE 4 System of FIG. 1 - Conventional Multi-Stage Cleaner System SUMMARY Flow Cons. Ash Ash Dirt > 150 Dirt > 160 gpm % STPD % STPD ppm/1.2 g m 2 /day Washer Thick Stock 540 10.37 335.7 2.53 8 5 720 3310 DWw 4272 0.03 7.7 7 0.5 1504 158 Gyro Accept 4812 1.19 343.4 2.63 9.0 738 3468 Gyro Accept 4812 1.19 343.4 2.49 8 55 738 3468 Dil. Water 4741 0.03 8.5 7.00 0 60 1504 176 Total in 9553 351.9 9.15 3644 1 st Stage Cleaner Accept 9492 0.60 343 0 2.43 8 34 596 2798 Total out Accept 9492 343.0 8 34 596 2798 Diff. In-out 60 8.9 0.8 846 5 th Stage Cleaner Rejects 60 2 46 8.9 9.04 0.80 6957 847 Total Rejects 60 8.9 0.8 847 Cleaner to Press DRE: 30.0% DRE Dil. Water Out 9334 0 03 16.8 Press Out 158.5 35.1 326.2 1.9 6.2 417 1863 Press to DIP DRE: 93.3% DRE DIP 28 PROCESS Washer - DIP 96.1% DRE
[0048] [0048] TABLE 5 System of FIG. 2 - Multi-Stage Cleaner System with Flotation Cell on 2 nd Stage Rejects SUMMARY Flow Cons. Ash Ash Dirt > 150 Dirt > 160 gpm % STPD % STPD ppm/1.2 g m 2 /day Washer Thick Stock 540 10.37 335 7 2.53 8.5 720 3310 DWw 4272 0.03 7 7 0 7 0.1 150.4 16 Gyro Accept 4812 1.19 343.4 2.49 8 5 708 3326 Gyro Accept 4812 1.19 343 4 2.49 8.55 708 3327 Dil. Water 5666 0.03 10.2 0.70 0.07 150 21 Total in 10478 353.5 8.62 3348 1 st Stage Cleaner Accept 9492 0.57 327.0 2.25 7.34 461 2063 3 rd Stage Cleaner Accept 927 0.43 23.8 1 39 0 33 373 121 Total out Accept 10419 0.56 350.8 7.68 455 2185 Diff. In-out 58 2.7 0.9 1164 Comer Rejects 42 0.93 2.3 34.77 0.81 32762 1050 5 th Stage Cleaner Rejects 16 0.36 0.3 32 88 0.11 23680 113 Total Rejects 58 2.7 0.9 1163 Cleaner to Press DRE: 30.0% DRE Dil. Water Out 10261 0.03 18.5 Press Out 158.5 35.1 332.4 1.9 6.3 318 1449 Press to DIP DRE: 93.3% DRE DIP 21.3 PROCESS Washer - DIP 97.0% DRE
[0049] [0049] TABLE 6 System of FIG. 3 - Multi-Stage Cleaner System with Flotation Cell on 1 st Stage Rejects SUMMARY Flow Cons. Ash Ash Dirt > 150 Dirt > 150 gpm % STPD % STPD ppm/1.2 g m 2 /day Washer Thick Stock 540 10.37 335.7 2.53 8.5 720 3310 DWw 4272 0 03 7 7 0.7 0.1 150.4 16 Gyro Accept 4812 1.19 343.4 2.49 8.5 708 3326 Gyro Accept 4812 1 19 343.4 2.49 8.55 708 3327 Dil. Water 7449 0 03 13.4 0.70 0.09 150 28 Total in 12261 356.8 8.64 3355 1 st Stage Cleaner Accept 9492 0.50 282.9 2.13 6.04 443 1715 2 nd Stage Cleaner Accept 2679 0.42 67.1 1.12 0.75 191 175 Total out Accept 12171 0.48 350.1 6.79 394 1890 Diff. In-out 90 6.7 1.85 1465 Comer Rejects 74 1.45 6 4 25.91 1 66 15279 1337 5 th Stage Cleaner Rejects 16 0.28 0.3 69.31 0.19 34056 128 Total Rejects 90 6.7 1.85 1465 Cleaner to Press DRE: 30.0% DRE Dil. Water Out 12012 0.03 21.6 Press Out 158.5 35.1 328.5 1.9 6.2 276 1241 Press to DIP DRE: 93.3% DRE DIP 18.5 PROCESS Washer - DIP 97.4% DRE
[0050] [0050] TABLE 7 System of FIG. 4 - Multi-Stage Cleaner System with Flotation on 1 st St. Rejects + 3 rd St. Accepts SUMMARY Dirt > 150 Flow Cons. Ash Ash ppm/1.2g Dirt > 150 gpm % STPD % STPD Double-dirt m 2 /day Washer Thick Stock 546 10.37 339.5 2.51 8.52 1489 6921 DWw 4266 0.015 3.8 0.7 0.0 300 16 Gyro Accept 4812 1.19 343.4 2.49 8.55 1476 6937 Gyro Accept 4812 1.19 343.4 2.49 8.55 1476 6937 Dil. Water 7543 0 015 6 8 0.70 0.05 300 28 Total in 12355 350.1 8.60 6985 1 st Stage Cleaner Accept 10100 0 46 279.2 2.15 6.01 816 3118 2 nd Stage Cleaner Accept 2104 0.50 62.9 1.16 0.73 346 298 Total out Accept 12204 0 47 342.2 1.97 6.74 729 3416 Diff. In-out 151 8.0 1.9 3549 Comer Rejects 143 0 91 7.8 23.75 1.85 31464 3347 5 th Stage Cleaner Rejects 8 0 41 0.2 7.68 0.02 72988 202 Total Rejects 151 8.0 1.9 3549 Cleaner to Press DRE: 30.0% DRE Dil. Water Out 12045 0.015 10.8 Press Out 158.5 35.1 331.3 1.9 6 3 511 2316 Double-dirt Press to DIP DRE: 93.3% DRE DIP 34 Double-dirt PROCESS Washer - DIP 97.7% DRE
[0051] [0051] TABLE 8 System of FIG. 5 - Multi-Stage Cleaner System with Flotation Cell on both 1 st Stage Rejects. SUMMARY Dirt > 150 Flow Cons. Ash Ash ppm/1.2 g Dirt > 150 gpm % STPD % STPD double-dirt m 2 /day Washer Thick Stock 546 10.37 339.5 2.51 8.5 1489 6920 DWw 4266 0.015 3.8 0.7 0.0 300 16 Gyro Accept 4812 1.19 343.3 2 49 8.5 1476 6935 Gyro Accept 4812 1.19 343.4 2.49 8.55 1476 6937 Dil. Water 7431 0.015 6.7 0.70 0 05 300 27 Total in 12243 350.0 8 60 6964 1 st Stage Accept 8417 0 44 223.0 1.89 4.21 523 1596 Cleaner 2 2 nd Stage Cleaner Accept 3619 0.53 115.3 1.36 1.56 388 612 Total out Accept 12036 0.47 338.3 5.77 477 2208 12036 0.55 400.0 Diff. In-out 208 11.8 2.8 4756 Comer Rejects 192 0.99 11.4 24.65 2.81 28167 4389 5 th Stage Cleaner Rejects 16 0.39 0.4 8.54 0.03 71490 367 Total Rejects 208 11.8 2.8 4756 Cleaner to Press DRE: 30.0% DRE Dil. Water Out 11856 0.015 10.7 0 70 0.1 Press Out 180.0 35.16 327.6 1 74 5.7 334 1497 379.5 double-dirt Press to DIP DRE: 93.3% DRE DIP 22 double-dirt PROCESS Washer - DIP 98.5% DRE
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A hybrid system for processing papermaking fibers includes a multistage array of forward cleaners coupled with a flotation cell which increases overall efficiency of the system. In a typical embodiment, a first rejects aqueous stream from a first stage bank of centrifugal cleaners is treated in a flotation cell before being fed to a second stage bank of centrifugal cleaners.
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FIELD OF THE INVENTION
The invention relates to a yarn supply device group for attaching to a textile machine, in particular a ring knitting machine with electrically controllable switching or actuating elements in every supply device which are connected in a signal-transmitting circuit to a central control mechanism by a bunch of lines common to all devices.
BACKGROUND OF THE INVENTION
From European Patent Application No. 801 067 19 (corresponds to U.S. Pat. No. 4,386,508) is known to construct a bunch of lines as a flat multi-conductor cable, in which at least as many conductors or wires are arranged side-by-side as there are supply devices in the supply device group. Since for example fourteen or more supply devices can be associated with one knitting machine, and since for every supply device, if necessary, several lines or wires in the bunch of lines are needed, the bunch of lines has considerable dimensions and is difficult to store, due to extremely cramped space conditions. Furthermore, the function-correct connection and "marking" of the supply devices, prior to the first use of the textile machine or after rearrangement or the connecting or "marking" of one or several exchanged supply devices, is extremely expensive. It is namely necessary that an operator manually and suitably position one or several contact pins inside of the supply device, so that the suitable circuit connections between the switching or actuating elements and the central control mechanism are formed. This manual "marking" in addition is time-consuming and causes an undesirably long stand-still time for the textile machine.
The basis of the invention is the technical problem of how to construct a yarn supply device group of the above-identified type so that the structural provisions for connecting the supply devices to the central control mechanism are considerably reduced and so that mainly the adjusting or "marking" of the supply devices in the supply device group is simplified and can be carried out more quickly.
SUMMARY OF THE INVENTION
The set problem is solved inventively by providing a yarn supply device group in which each supply device has an electronic switching arrangement which contains a writable and readable memory associated with the switching or actuating devices, which can be supplied with a unique address from the central control mechanism and which, after having been supplied with the address, can be controlled by being addressed, wherein the switching arrangements of all supply devices are connected in the same manner to the bunch of lines.
In this construction, due to the electronic switching arrangement, to which can be fed an address from the central control mechanism, a manual marking of each supply device is not necessary. As soon as operation starts, the central control mechanism supplies an address to each electronic switching arrangement, under which address then during operation each supply device can be controlled individually. This means that the supply devices of the group need only be fixed mechanically without "marking" and that then the textile machine is immediately ready for operation. A further, important advantage consists in the bunch of lines containing only a small number of lines, since all supply devices are connected in the same manner to the same lines, so that the connection can be carried out relatively simply and the structural parts and the space for storing the bunch of lines is considerably reduced, because it is no longer necessary to select for each supply device a specific line or lines. The bunch of lines can be integrated structurally without any difficulties into the supply device group or the storing of the group, so that little space is needed for the bunch of lines and it no longer hangs around interferingly between the individual supply devices and the central control mechanism. The standstill times of the textile machine, prior to starting operation, after breakdowns in operation, after change-over operations during which, if necessary, individual supply devices of the group were exchanged, after repair or exchange operations, and during method changes, can be shortened drastically through this.
Particularly advantageous is thereby an embodiment in which the bunch of lines includes a line which is designated for carrying the addresses and is connected to the switching arrangements in series, while the switching arrangements are connected in parallel to the other lines of the bunch of lines. During the first adjusting of the supply devices of the group, just as little care must be taken for connecting the individual cables to the switching arrangement as after exchanging the positions of supply devices of the group, since the exchanged supply devices assume the same positions with respect to the lines of the bunch of lines as the supply devices which were provided earlier at such places. With the series connection in one line of the bundle of lines, the assigning of addresses to the individual supply devices can be carried out according to a relay circuit, so that even after an exchange, supply devices of the group can be controlled again individually from the central control mechanism without having to be "marked" again.
A further advantageous embodiment of the invention provides a microprocessor in each switching arrangement Microprocessors are simple, premanufactured and inexpensive electronic structural elements which can be programmed selectively for respective applications. They are commercially available and require, for example as chips, extremely little space for storage. It would, of course, be conceivable to use in place of a microprocessor a custom electronic switching arrangement; but this would be substantially more expensive than a microprocessor, which is usable for many different purposes and is programmed in view of the expected, known steps.
Since in such a textile machine under certain operating conditions, for example during starting up of the normal operating program or during stopping of a specific quality of goods, the supply devices of the group are supposed to operate only according to a simplified program, or since it may be necessary to leave one or some of all existing supply devices passive, it is advantageous if each switching arrangement has a manually operable switch with which its microprocessor can be separated from the lines of the bunch of lines. Since during switching off of this switching arrangement the current flow in the one line of the bunch of lines in which the switching arrangements are arranged in series remains, the assigning of the addresses to the remaining supply devices and their individual control through the switching off of the switching arrangement is not influenced.
A further, advantageous embodiment involves the microprocessor of each switching arrangement having a read only memory for at least one fixed control program. Fixed programs can be stored in such read only memory or the read only memories and can be read either under control of the central control mechanism or by operations in the respective supply device itself. In this construction, a universal usability of the supply devices is achieved.
Furthermore, also advantageous is an embodiment in which the central control unit contains a microprocessor having an input connected to at least one signal producing control element which provides, for example, the operating clocks, operating position, operating speed and the like of the textile machine. In this manner, not only a structural simplification and universal usability of the central control mechanism for various operating methods is made possible, but it is also assured that the central control mechanism and the supply devices in the group can be operated in strict and desired dependence from the operating clocks or the operating speed during each operating phase. Due to this control of the central control mechanism, it and also the supply devices remain independent from fluctuations in the operating clock or the operating speed during each operating phase. It is thereby also advantageous that the coupling between the textile machine and the central control mechanism occurs also in an electrical or electronic manner which is not susceptible to breakdowns and needs little installation space.
A further, advantageous thought involves the microprocessor of the central control unit being able to store and selectively recall at least one fixed program for effecting a uniform control of all switching arrangements. Here again a central control mechanism right from the start receives the possibility to adjust and uniformly control the supply devices during specific steps which differ from the normal working operation according to these respective conditions.
A further, advantageous measure which results in a simplification of the operation involves the provision in each switching arrangement of a device for detecting, coding and transmitting the occurrence of an error to the central control unit, the central control unit having an error indicator. This additional device in every supply device fulfills the purpose to localize errors which occur in every supply device and to analyze same and make them recognizable by the central control mechanism, so that it can stop the textile machine and at the same time announce the type of error.
It has thereby proven advantageous if each supply device has an error indicator controlled by its microprocessor, since then in the region of the central control mechanism the type of error can be recognized, and in addition it can indicate in which supply device the error occurred. The search for the error and the correction of the error is substantially simplified through this.
An embodiment which is particularly protected against damage from dirt and other outside influences is one in which each yarn supply device has a housing which contains its switching arrangement. Especially during use of a microprocessor, the space which is available in common supply devices is very sufficient for storing the switching arrangement.
Finally, a further advantageous embodiment is one in which the central control unit and the yarn supply device are all supported on an annular carrier. The bunch of lines can hereby be located in the annular carrier, on which is also secured the central control mechanism. Thus, interfering and space-consuming cable connections between the central control mechanism and the supply devices are not needed. As is known already, during fastening of the supply devices on the annular carrier, the respective correct connections between the control mechanism and the switching arrangements can be created.
A particularly advantageous use of the subject matter of the invention results in connection with an electronically or electrically controlled ring knitting machine, in which the individual ring devices are controlled centrally by a so-called pattern computer. Such pattern computer can be connected to the central control unit for the supply devices with the interpositioning of an interface switching circuit, which causes the central control unit and also the microprocessors in the supply devices to be controllable in parallel with the signals from the pattern computer which are also intended for the ring devices and, for example, indicate the respective colors or a color change. Thus, the step which is necessary during the mechanical control of the ring devices is not needed in the individual supply devices, with which step the yarn-guiding arms which are on the output side are lifted into a central position, from which then a signal is formed by a yarn-guiding arm which is moved under the yarn tension from the side of the ring device, which signal indicates to the microprocessor in the supply device which color must now be continuously delivered. This step occurs sensibly during each machine phase, even if no yarn change takes place. During the electronic control of the ring devices, through the saving of this step, a simplification is achieved, since the microprocessors in the supply devices are utilized for fewer switching operations and also the central control unit has to carry out fewer switching operations, since the microprocessors in the supply devices can each be controlled directly with the order for a color change and for the respective color.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in connection with one exemplary embodiment which is illustrated in the drawings, in which:
FIG. 1 is a partially cross-sectional side view of an exemplary embodiment of a supply device;
FIG. 2 is a cross-sectional view taken along the line II--II of FIG. 1;
FIG. 3 is a partially cross-sectional rear view of the exemplary embodiment of FIG. 1;
FIG. 4 is a block diagram of the electronic circuit in each supply device;
FIG. 5 is a block diagram of an electronic control unit which is utilized for controlling all supply devices of FIG. 1;
FIG. 6 is a schematic top view of a fourteen-device ring knitting machine;
FIG. 7 is a timing diagram for the control of the supply devices.
DETAILED DESCRIPTION
A supply device for positive yarn delivery has a housing 1 with a clamp portion 3 which can be fastened to a support ring 2 of the knitting machine, namely with a screw 4. The support ring 2 carries above the knitting systems a number of such supply devices which corresponds to the system count of the machine (FIG. 6).
The clamp portion 3 extends with a projection 3A into the housing 1 and divides same into chambers 1A or 1B. The projection 3A extends in FIG. 1 beyond the housing 1 and forms a support plate 3B for a vertical, nonrotatable axle 3C. Several (here four) yarn-feeding wheels 5A, 5B, 5C, 5D are supported rotatably on the axle 3C with bearings (not illustrated). A tape 6A, 6B, 6C or 6D which is driven in synchronism with the knitting machine runs over each wheel. The number of yarn-feeding wheels corresponds with the number of preferably different-colored yarns for the associated ring device.
In the housing 1, at the same level as the wheels 5A, 5B, 5C and 5D, there are supported four times two =eight yarn-guiding arms 7A in, 7A out, 7B in, 7B out, 7C in, 7C out, 7D in, 7D out on axles which extend horizontally into the housing 1.
All arms 7A in, 7B in, 7C in and 7D in for the incoming yarns are supported identically, as are the arms 7A out, 7B out, 7C out and 7D out for the outgoing yarns, so that only the arms 7A in and 7A out will be described hereinafter.
An armature plate 8A is supported on the axle of the arm 7A in, which plate cooperates with an "engagement" electromagnet 9A which, when actuated, swings the armature plate 8A against the action of a spring 10A in a clockwise direction (upward in FIG. 1). When the electromagnet 9A is no longer actuated, the spring moves the arm 7A in a counterclockwise direction (downward in FIG. 1) toward a stop 11A.
A support plate 12A (see 12D in FIG. 1) for a draw spring 13A (see 13D in FIG. 1) is supported on the axle of the arm 7A out, the other end of which draw spring is supported on a support plate 14A (see 14D in FIG. 1) which in turn is secured on the housing 1 by means of a screw 15A. The draw spring 13 pulls the arm 7A out in a counterclockwise direction (namely upward in FIG. 1). On the axle of the arm 7A out, there is fastened an essentially L-shaped plate 16A with a stop surface 17A for limiting counterclockwise movement of the arm 7A out, an actuation surface 18A and a contact plate 19A. A contact cam 20A is secured on the axle of the arm 7A. The contact plate 19A of the L-shaped plate 16A cooperates with a stationary contact plate 21A on a projection 22A. A contact tongue 24A is secured by means of a screw 23A on the projection 22A, which extends vertically downwardly and cooperates with the contact cam 20A. The operating surfaces 18A, 18B, 18C and 18D of the other arms 8B out, 8C out or 8D out cooperate with further operating surfaces 25A, 25B, 25C or 25D of a vertical draw bar 26 which is secured on an armature (not illustrated in FIGS. 1 to 3) of a lifting electromagnet 27. When the electromagnet 27 is actuated, the draw bar 26 is moved upwardly a small distance, which causes the arms 7A out, 7B out, 7C out to be swung in a counterclockwise direction into a center position, since the draw bar 26 with its surfaces 25A, 25B, 25C or 25D engages the plates 16A, 16B, 16C or 16D on the axles of the arms 7A out, 7B out, 7C out or 7D out. The contact cams 20 do not yet cooperate in the center position of the arms with the contact tongues 24.
When the electromagnet 27 is no longer actuated, the draw bar 26 drops back into its rest position, due to its weight and the weight of the armature (FIG. 1).
The contact plates 21A, 21B, 21C and 21D and the contact tongues 24A, 24B, 24C and 24D are connected by (not illustrated) electrical lines to a contact pin 28S (FIG. 1) of an electrical circuit board 28 (FIG. 2) which contains a switching arrangement in the form of a microprocessor which will be described hereinafter.
Further contact pins of the electrical circuit board 28 are connected with contact sockets 29 or 30 to further lines (not illustrated), which contact sockets 29 or 30 are provided here on opposite sides of the housing (see FIG. 2). To each socket there is connected a flat cable with preferably six conductors, which is utilized as a so-called "bus cable" in order to feed control signals and a supply current to an electronic central control unit CU (FIGS. 5 and 6) and to receive signals from same, which is preferably secured on the support ring 2 and contains a microprocessor. In place of the sockets 29, 30 it would also be possible to provide a contact-pin arrangement in the chamber 1b, with which then the conductors of the bus cable can be connected at the support ring 2.
Furthermore, plates 31 and 32 are secured on the housing 1, which plates extend outwardly and respectively have four fixed ceramic eyelets 33A, 33B, 33C and 33D for guiding the yarns FA, FB, FC or FD and four fixed ceramic eyelets 34A, 34B, 34C and 34D for guiding the yarns FA', FB', FC' or FD'. The yarns are positively guided by the wheels 5A, 5B, 5C or 5D and the tapes 6A, 6B, 6C or 6D and leave the supply device downwardly to a ring device, in which they are detected by fingers and are guided on downwardly to the needles of the knitting machine. Between the eyelets 33A, 33B, 33C or 33D and the wheels 5A, 5B, 5C or 5D, the incoming yarns FA, FB, FC or FD run through ceramic eyelets 35A, 35B, 35C or 35D on the free ends of the arms 7A in, 7B in, 7C in or 7D in.
The outgoing yarns FA', FB', FC' or FD' run through ceramic eyelets 36A, 36B, 36C or 36D at the free ends of the arms 7A out, 7B out, 7C out or 7D out, after they have passed through the eyelets 34A, 34B, 34C or 34D.
A lamp 37 in FIG. 1 provides a visual error indication, while a manual switch 38 is designated for switching off the microprocessor in the supply device.
FIG. 4 illustrates the microprocessor FMP (supply device microprocessor), for example a so-called "one-chip" microprocessor, in a supply device FU n (where n lies in this case between one and fourteen). The microprocessor is supplied with a voltage of 5 V (direct voltage) by a voltage threshold, which from a 24 V voltage supply lets through only 5 V for other switching arrangements in the supply device, and is connected by the "bus cable" in the form of the flat cable with six conductors to identical microprocessors of the two adjacent supply devices. The first supply device FU1 (FIG. 6) and the last supply device FU14 of the group are connected to the control unit CU, which is illustrated in FIG. 5 and FIG. 6. The "bus cable" contains a line for the voltage supply and five signal lines for controlling the microprocessor in every supply device or for monitoring the system with respect to occurring errors of various types. These cables are identified in FIG. 4 with: RESET, STOP SIGNAL, CLOCK, DATA, and RELAY. The functions which can be effected therewith will be described later. It is important that the microprocessors FMP are connected in series in the cable RELAY, while in the remaining cables they are connected in parallel with one another.
The microprocessor FMP is connected in the supply device to the "trig" contacts 19A/21A, 19B/21B, 19C/21C and 19D/21D and to the "stop" contacts 20A/24A, 20B/24B, 20C/24C and 20D/24D.
The microprocessor FMP controls, through a driving circuit which is supplied with 24 V, the electromagnets 9A, 9B, 9C and 9D, the lifting magnet 27 and the lamp 37. The manual switch 38 can switch off all functions in the microprocessor FMP, with the exception of the transmission of the RELAY signal. When the switch is in its "off" position, the microprocessor FMP does not take notice of any other information on the "bus cable".
The central control unit CU in FIG. 5 consists in reality of a microprocessor CMP (central microprocessor), which is also a "one-chip" microprocessor supplied with plus 5 V direct voltage.
For synchronizing the operation of the microprocessor CMP in the central unit CU with the operation of the ring knitting machine, a position sensor SYNC is provided (for example a Reed switch) which cooperates with the drive shaft of the rib cylinder of the knitting machine in order to feed one pulse per revolution of the knitting machine to the microprocessor. A for example photoelectrical sensor FREQ cooperates with a toothed disk on the drive shaft of the knitting machine in order to feed a pulse train having a frequency which corresponds to the momentary speed of the knitting machine to the microprocessor CMP in the control unit CU.
The microprocessor CMP is connected to a display DISPLAY in the control unit CU which indicates only two characters which provide a visual, coded indication of the type of an occurring error, whereby for example a yarn breakage is indicated with the code "1 1" and an error in the signal transmission with the code "2 2".
The microprocessor CMP in the control unit CU is connected, for communicating with the respective microprocessors FMP in every supply device of the system, according to the invention to the "six wire bus cable" which is mentioned in connection with FIG. 4.
T1, T2, T3 and T4 (FIG. 5) identify four manual switch buttons in the area of the central control unit, the function of which will be described hereinafter.
FIG. 6 illustrates the supply devices FU1 to FU14 and the control unit CU on the support ring 2 of the knitting machine. It can thereby be recognized how the feeding tapes 6A, 6B, 6C and 6D are driven by a shaft 39 through a roller 40 with a variable diameter (for changing the tape speed) and a stretching device 41 with a drive belt 42.
The described exemplary embodiment operates as follows.
When the power supply for the ring knitting machine is switched on, each supply device FU1 . . . FU n . . . FU m in the group receives a specific address from the control unit CU, whereby m equals the total number of supply devices and is fourteen. In other words, each supply device receives a unique number which it keeps until the next addressing operation takes place, namely until the ring knitting machine is switched on the next time.
The addressing is carried out by the control unit CU, which sends out a signal, for example a binary zero (equals a low potential) on the RELAY line when it starts to send pulse trains on the CLOCK line. The signal on the RELAY line enters the microprocessor FMP1 of the supply device number 1 (FU1), whereby same is programmed so that it starts to count and stores in an internal memory the number of clock pulses which occurred up to this point in time on the CLOCK line, namely in this case "one". The signal on the RELAY line continues from the RELAY output of the microprocessor FMP1 in the supply device FU1 to the RELAY input of the microprocessor FMP2 in the supply device FU2, which upon receipt of the RELAY signal reads that so far two pulses occurred on the CLOCK line, whereby this number is stored in its internal memory. The RELAY signal continues to run from supply device to supply device until it has passed the last supply device FU m of the group, the microprocessor FMP m of which reads or counts that m pulses have occurred on the CLOCK line, so that this supply device receives the address "m" (for example "fourteen").
The important advantage in this addressing operation or "marking" of the supply devices lies in the supply devices, if this should be desirable for one reason or another, being able to be moved or exchanged freely within the system. The position of each supply device in the group can be changed freely, or alternatively one supply device can be replaced with a new supply device without a "marking" being carried out manually, as is necessary in the known system according to European Patent Application No. 80106719.9. In the known system, the supply devices must be "marked", in that the position of a specific contact pin must be adjusted to a specific wire in the flat multi-conductor cable.
The automatic addressing operation in the inventive system eliminates also the up-to-now existing disadvantage of the first-time "marking" by hand prior to the first operation of the ring knitting machine.
In the described exemplary embodiment, knitting station No. 12, namely supply device FU12, is for example viewed now. At a certain moment, the needles of the ring knitting machine work with the yarn FD', which is fed positively by the uppermost yarn feeding wheel 5D by means of the yarn feeding tape 6D. Just then a change to the yarn FA' takes place in the associated ring device.
Immediately prior to such moment, the control unit CU, which operates in synchronism with the knitting machine, sends out an addressing or calling signal in the form of a 6-bit word (whereby the highest possible address is sixty-four), in this case the number "twelve", namely on the DATA line. The microprocessors in all supply devices FU1 to FU14 receive the information on the DATA line each time they receive a pulse on the CLOCK line. They are programmed so that they compare the calling signal, which was sent out by the central control unit, with the address which is stored in their internal memory and
(1) if the comparison is positive, respond to the calling signal by sending back a receipt signal to the central control unit CU on the STOP signal line, whereas,
(2) if the comparison is negative, they do not respond to the calling signal.
Upon receiving back such a receipt signal, the central control unit CU sends out one or several orders or order signals on the DATA line, whereby each order signal is a 4-bit word (the possible total number of orders is sixteen), but only the microprocessor FMP12, which was called, is enabled to read or to receive the order signal or signals which occur on the DATA line. If the central unit does not receive the receipt signal promptly after sending out the addressing or calling signal, it produces in accordance with its program an error indication or a STOP signal for the knitting machine.
At this very moment, the order or the instruction to the microprocessor in the supply device FU12 is to "disengage the positive feed", (order I). During receipt of the order I, the microprocessor FMP of each supply device carries out three different operations, namely:
(1) to switch off the current to all "engagement" electromagnets 9A, 9B, 9C and 9D in the supply device;
(2) to switch on the current to the "lifting" magnet 27;
(3) to switch off the stop function of all arms 7A out, 7B out, 7C out and 7D out, namely the co-acting contact cams 20A, 20B, 20C and 20D and the contact tongues 24A, 24B, 24C and 24D.
Through the operation (1), the "working" arm 7D in is swung inward in a counterclockwise direction, namely downwardly in FIG. 1, which causes the yarn FD on the feeding wheel 5D to be pulled out from under the feeding tape 6D, and the positive feeding is stopped.
Through the operation (2), the draw bar 26 is moved, which causes the "working" arm 7D out, and also the other arms 7A out, 7B out or 7C out, which possibly in this moment are in their lower position, for example due to the elasticity of the yarns, to be rotated a distance in a counterclockwise direction, namely in FIG. 1 upwardly, into a predetermined central position. The contacts 20, 24, however, are not closed.
The central control unit CU now again sends the address signal "twelve" on the DATA line. The microprocessor in the supply device FU12 operates by sending back a receipt signal to the central control unit on the STOP SIGNAL cable, whereupon the control unit CU sends out a new order II on the DATA line, which again is only carried out by the supply device FU12. The order II reads "change the color". The microprocessor FMP of each supply device is programmed to proceed upon receipt of the order II as follows:
(4) all arms 7A out, 7B out, 7C out, 7D out are released, since the lifting magnet 27 is de-energized; and
(5) the current is switched on to the "engagement" electromagnet 9A, 9B, 9C or 9D whose associated arm 7A out, 7B out, 7C out or 7D out has been moved by a yarn FA', FB', FC' or FD' into a so-called "trig position", whereby such yarn must now be processed and is therefore tensioned. The "trig-position" corresponds with the contact position of the plates 19A/21A, 19B/21B, 19C/21C or 19D/21D, in this case the contact plates 19A/21A, as is illustrated in FIG. 1.
Through this operation, the corresponding arm 7A in, 7B in, 7C in or 7D in, in the present case 7A, moves the yarn FA, FB, FC or FD, in the present case FA, upwardly into a position under the corresponding yarn feeding tape on the feeding wheel so that it is fed positively, namely with a constant speed in synchronism with the ring knitting machine.
An internal program routine runs thereby in the microprocessor FMP of the supply device in order to ensure that the correct yarn is fed positively, regardless of the fact that disturbances can occur in the supply device, for example due to an increased tension due to the elasticity of the just stopped yarn. It may also happen that two output arms are moved into the "trig position" and each produce a trig signal. If then the microprocessor FMP would not have any internal program routine (as described hereinafter), two yarns would be fed positively. The internal program routine operates in four different possible cases as follows (see FIG. 7):
The uppermost signal diagram in FIG. 7 illustrates the rear edge of the actuating pulse for the "lifting" magnet 27 of the supply device, namely the electromagnet is de-activated at the moment t1 and releases the arms 7A out, 7B out, 7C out and 7D out, so that they are prepared for the next operation, which produces a "trig signal". In the case 1, namely at the moment t2, the arm 7A was moved outward into the "trig position" due to a color change, since in the ring device a new yarn FA' was picked up. In this case, the microprocessor FMP produces as programmed at the moment t2 an actuating signal and switches on the current to the electromagnet 9A.
In case 2, the arm 7D out was moved with the old yarn FD' at the moment t3 into the "trig position". In this case, a color change in the ring device will not take place during the knitting machine rotation; rather, the needles continue to knit the old yarn FD'. At the moment t3, a "timer routine" starts in the microprocessor FMP, while the microprocessor FMP is waiting for a possible "trig signal" for a new yarn, namely for the yarn FA. If during this "timer routine" (duration 20 ms) such a "trig signal" does not occur, then the microprocessor FMP produces in accordance with the program an actuating signal at the moment t3+20 ms, namely it switches on again the current to the electromagnet 9D for the old yarn, so that same has priority and is again fed positively.
In case 3, the arm 7D out is again moved at the moment t4 with the old yarn FD into the "trig position". The "timer routine" is again started in the microprocessor FMP. However, a short time later, at the moment t5, a "trig signal" is also received by the arm 7A out with the new yarn FA. This can only mean that the arm 7D out was moved at the moment t4 erroneously into the "trig position", probably due to remaining tension in the yarn FD', which cannot be the case with the new yarn FA'. The microprocessor FMP gives, as programmed, the trig signal for the new yarn priority and produces at the moment t5 an actuating signal for the electromagnet 9A.
In case 4, no trig signal occurs whatsoever, either for the old yarn FD or for the new yarn FA, which means that an error exists, for example a yarn breakage. The microprocessor FMP in such supply device now produces and sends, as programmed, at the moment t6, determined by a third order signal III of the central control unit CU, a "GIVE STOP SIGNAL", a stop signal on the STOP SIGNAL line back to the control unit CU, which subsequently again sends out a stop signal to a stop motion relay in the knitting machine for stopping the machine. At this moment, the current to the error-indicating lamp 37 in the supply device which is in question here is switched on, so that the operator can easily determine at which knitting station the error occurred. The microprocessor CMP in the central control unit CU also sends out a signal to its error-type indicator, in the present case for example the code "1 1".
In all of the cases 1, 2 and 3, the microprocessor FMP in the supply device automatically switches on as programmed the stop function for the respective output yarn guiding arm only for the yarn which has given the "trig signal", namely in case 1 for the new yarn FA, in case 2 for the old yarn FD and in case 3 for the new yarn FA. The stop function, namely the current feed to the contact cams 20A, 20B, 20C or 20D and the contact tongues 24A, 24B, 24C or 24D, is programmed so that, in all supply devices, it is switched on promptly after the "trig signal" occurs in the supply device.
In cases 1, 2 and 3, the microprocessor FMP in the supply device accordingly does not answer the order signal 3 "GIVE STOP SIGNAL", since a "trig signal" was received, which means that no error, as for example a yarn breakage, existed.
On the other hand, the microprocessor FMP in every supply device is programmed for normal operation so that it sends back promptly a stop signal on the "STOP SIGNAL" line to the central control unit if a thread breakage in the just knitted yarn occurs, so that the knitting machine is stopped and an error-indicating lamp 37 and the display light up. Moreover, at the same time the current to all "engagement" electromagnets is switched off, so that the positive feeding of the threads is stopped in order to prevent a temporary overfeeding of yarn. After repairing the error, for example a yarn breakage at one of the supply devices, the operator switches on the restart switch T4 in the central control unit CU (see FIG. 5), which causes the microprocessor CMP in the control unit, as programmed, to switch off the current to the stop motion relay of the knitting machine and simultaneously to give the order to the microprocessor FMP in the supply device in which the error to switch off the error-indicating lamp 37 occurred, assuming that the stop contact which is in question here is again open. In this case, no "reset" of the program routine in the control unit takes place, but the system starts again as programmed by carrying out the operation which would have been next when the error occurred.
The operator can reset with the switch T1 the entire program in the microprocessor CMP of the central control unit CU and the microprocessors FMP in all supply devices, whereupon the entire program is again started automatically when the control unit receives the next synchronization pulse from the position sensor SYNC (see FIG. 5).
The switch T2 causes the central control unit CU to send out a specific common order to the microprocessors in all supply devices in order to keep all electromagnets 9A, 9B, 9C and 9D without current so that no yarn is fed positively. The trig signal of the "trig contacts" 19A/21A, 19B/21B, 19C/21C or 19D/21D is thereby, however, designed so that it concerns, just like prior to the stop function, only the yarn which is currently being knitted. This mode of operation can be of considerable importance during running of a new quality of material in the machine, namely before the speed of the tapes 6A, 6B, 6C and 6D (namely the yarn speed) is adjusted correctly in relationship to the speed of the knitting machine.
Finally, the switch T3 effects in the control unit CU an additional specific order to the microprocessors FMP of all supply devices which causes the current to the one of the electromagnets 9A, 9B, 9C, 9D, which was operated by a "trig signal" to remain switched on, whereas the lifting-engagement electromagnets 27 are not actuated as during the normal mode of operation during one machine rotation. This means that the respective yarn is constantly being fed positively. This special function can be utilized when the ring knitting machine is to be used for knitting smooth fabric.
The invention is not limited to the above-described exemplary embodiment which is illustrated in the drawings, and a number of modifications are possible which are within the scope of the invention.
The described exemplary embodiment is intended for a mechanically controlled ring knitting machine, in which the ring devices are controlled in a mechanical manner from a central control unit.
However, the invention can be utilized particularly advantageously for an electronically controlled ring knitting machine, in which the ring devices are controlled electrically through the central control unit. The information for the color change or the yarn change is accessible electrically in the central pattern program system of the knitting machine itself. This means that, in this case, the necessity for a temporary lifting of the arms 7A out, 7B out, 7C out or 7D out into a "central" position and for the lowering of the arms by the new yarn does not exist. Since the temporary lowering of the output yarn guiding arms is not needed, a "lifting" electromagnet 27 is not needed. It is then also unnecessary to block the stop function for the output yarn guiding arm during the time during which the central control unit sends out an order for ending the positive feed in the respective supply device.
In the electrically controlled ring knitting machine, the microprocessor CMP is programmed to send an order for the positive feed to the respective supply device and to simultaneously inform the microprocessor FMP in the supply device which of the four "engagement" electromagnets 9A, 9B, 9C or 9D is to be operated.
Then, the stop function is switched on only for the yarn which was ordered by the central control unit CU for the positive feed.
When using the supply device group in a mechanically controlled ring knitting machine, the microprocessor CMP of the central control unit CU is, in dependence on the respective type of the ring knitting machine, designed or programmed right from the start with various information tables in its internal memory (whereby the information tables can vary in dependence on the number of knitting stations of the machine, the spaces between the knitting stations and the like), so that the operations which as a whole are to be carried out in all supply devices, the sequence in which such operations are to be carried out, and the points in time at which these operations must be carried out is established. The points in time at which these operations must be carried out are determined by establishing at which pulse in the pulse train from the pulse generator FREQ they must be started, whereby the synchronization pulses which the microprocessor receives from the position sensor SYNC are counted.
When using the subject matter of the invention in an electronically controlled ring knitting machine, these information tables for the microprocessor CMP in the central control unit CU do not need to be so extensive, since in this case the microprocessor CMP works "on-line" with the knitting machine pattern computer, namely through an interface circuit IC (indicated by dashes in FIG. 5), and therefore continuously receives information from the pattern computer PC which informs it of the necessary color change data during each machine rotation.
All other functions are in this case substantially the same as in the earlier described exemplary embodiment, which is used in a mechanically controlled ring machine.
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The invention relates to a yarn supply device group for attaching to a textile machine, in particular a ring knitting machine with electrically controllable switching and actuating devices in every supply device which are connected in a signal-transmitting circuit by a bunch of lines common to all supply devices to a central control mechanism. Previously, every supply device in the group had to be "marked" manually prior to the start of operation. In addition, a bunch of lines with large dimensions was necessary, since each supply device needed at least one separate line. In the invention, manual "marking" is not needed, since in each supply device an electronic switching arrangement which contains a writable and readable memory is associated with the switching or actuating devices, can be supplied with an individual address from the central control mechanism, and after having been supplied the address can be controlled addresslike, and for connection of the supply device to the central control mechanism a small-dimensioned bunch of lines can be provided since the switching arrangements of all supply devices are connected in the same manner to the bunch of lines.
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FIELD OF THE INVENTION
[0001] The present invention relates to a domestic porridge making appliance, and more particularly to a domestic porridge making appliance in which a pulverizing means for pulverizing all kinds of grains like rice as one of main ingredients of the porridge together with various vegetables and a heating means for heating water and porridge ingredients are formed integrally with each other, thereby making it possible to prepare porridge in a more convenient way.
[0002] Generally, porridge is widely used for food use of patients who are ill or are in a recovering stage, for the health of old people or children, for stimulating people's appetite when they have a poor appetite, and sometimes for famine-relieving product at a time of want of food. From this viewpoint, therefore, the porridge is a basic form in cooking grains.
[0003] The kinds of porridge are rice porridge, rice and milk mixed porridge, nut porridge (porridge made of rice and pine nuts, sesame, walnuts, jujubes, dried chestnuts or the like), green beans or other porridge (porridge made of beans, red beans, mung beans, barley, unripe barley or the like), sea food porridge (porridge made of raw oysters, abalones, mussels, clams or the like), and meat porridge (porridge made of a variety of birds and meats or porridge made of beef and mussels).
[0004] In addition to the above mentioned kinds of porridge, there are porridges that are made of starch powder and Job's tears, lotus roots, water chestnuts, arrowroots, yams or the like, which gives extraordinary tastes, diet effects, and medical effects. And there are porridges that are made of rice and various vegetables like bean sprouts, mallows, dried radish leaves or the like, which is cooked for stimulating poor appetites.
[0005] Referring to the process of making porridge as used conventionally, grains like rice are heated with an amount of water in the range of 6 to 7 times with respect to the rice amount until the grains become thick. For example, rice is put and cooked in water made by boiling and straining mung beans or red beans, rice is put and cooked in the water made by boiling and grinding beans, and rice powder is mixed with all kinds of nut powder and cooked with the addition of water. In case of meat porridge, also, meat is minced, seasoned and roasted and then, rice is put and cooked with the roasted meat, or rice is put and cooked in soup that is made after well boiling and cooked with the very small pieces of meat.
[0006] However, the conventional porridge making method requires a relatively long period of time in keeping the grains or vegetables soaked in water, and it is inconvenient to keep porridge stirred, while being boiled in order not to make it scorched. In addition, in the case where the time for making the grains soaked in water is erroneously manipulated or where the amount of water is erroneously put, there is a problem that the taste of the porridge is not good.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the prior art.
[0008] An object of the present invention is to provide a domestic porridge making appliance and a method for making porridge by using the same that is capable of making porridge in more convenient and easier ways and substantially reducing the time required in making the porridge as compared with conventional methods.
[0009] According to a preferred embodiment of the present invention, a domestic porridge making appliance in which the appliance comprises a generally cylindrical cooking vessel into which a predetermined amount of water and porridge ingredients are put and having an upper side opened and a vessel handle grip formed at one side thereof for moving the cooking vessel; a driving part having a lower surface formed to correspond to the opened upper side of the cooking vessel, a motor disposed on the bottom surface thereof in such a manner as to be inserted into the inside of the cooking vessel wherein the motor having a pulverizing blade connected to an end of a rotating shaft thereof, a heater formed at the outside of the pulverizing blade for heating the water in the cooking vessel, and a controller formed at the inside thereof for controlling the motor and the heater, is characterized in that at the lower part of the peripheral surface of said driving part a ring type of insertion groove is formed for inserting and thereby fixing the upper part of said cooking vessel wherein at the inner surface of said insertion groove a plurality of protrusion pieces is in a form with curved surface, and at the upper surface of said cooking vessel a ring type of insertion protrusion is formed wherein at the outer surface of said insertion protrusion a plurality of protrusion step is in a form with a curved surface which contacts the curved surface of said protrusion piece formed at the inner surface of said insertion groove.
[0010] According to other embodiment of the present invention, the appliance is characterized in that a dented insertion groove is formed where each of said protrusion piece is formed to insert each of said protrusion step; and as counterpart another insertion groove is formed where each of said protrusion step is formed to insert each of said protrusion piece.
[0011] According to another embodiment of the present invention, an opening/closing switch is installed at said insert groove to detect the combination of said driving part and said cooking vessel.
[0012] According to a further embodiment of the present invention, said opening/closing switch contacts a sense installed at the upper part of said cooking vessel when said driving part is coupled with said cooking vessel.
[0013] According to still a further embodiment of the present invention, said d protrusion pieces and protrusion steps are three, respectively.
BRIEF DESCRIPTION OF THE INVENTION
[0014] The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:
[0015] FIG. 1 is a perspective view of the appliance according to the present invention;
[0016] FIG. 2 is an exploded perspective view of the appliance of the present invention;
[0017] FIG. 3 is a front view of the top surface of the appliance according to the present invention.
[0018] FIG. 4 is a sectional view of the internal structure of the appliance according to the present invention.
[0019] FIG. 5 is a sectional view of the opening-closing structure of the appliance according to the present invention.
[0020] FIG. 6 is an enlarged perspective view of an opening-closing structure of the appliance according to the present invention.
[0021] FIG. 7 is a block diagram of the configuration of the appliance according to the present invention.
[0022] FIG. 8 is a flow-chart showing the operation order of the appliance according to the present invention.
[0023] FIG. 9 is a flowchart showing the process of making porridge by using the domestic porridge making appliance of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0025] The terms used in the present invention are defined in accordance with the functions made in the present invention, which may be varied according to the intention or practices of those people who work in the art, and therefore, it should be understood that they do not limit the technical components of the present invention.
[0026] Referring to FIG. 1 to FIG. 4 , as shown, a domestic porridge making appliance 1 according to the present invention includes a driving part 100 in which a motor 125 and a controller 113 are housed, for pulverizing porridge ingredients (e.g., grains like soaked rice, beans, vegetables, meat, sea food and so on) and a cooking vessel 300 into which the porridge ingredients and water are put and pulverized by the driving part 100 detachably mounted thereto.
[0027] The driving part 100 includes an upper housing 110 that has a generally a cylindrical shape of appearance opened on the bottom surface thereof with a stepped protrusion at the top side thereof, the upper housing having the controller 113 mounted at an inside thereof, and a lower housing 120 that is coupled to the opened portion of the upper housing 110 and has the motor 125 mounted downwardly thereto.
[0028] The upper housing 110 is provided with a handle grip 111 , 111 a for moving the driving part 100 and the cooking vessel 300 on the rear and the top surface thereof, and with the controller 113 in which a timer 113 a is disposed for controlling each part of the domestic porridge making appliance 1 as time goes by, at the inside thereof. A power supply 115 is installed at the outer surface of the upper housing 100 for supplying power the motor 125 and the controller, and a wind outlet 116 may be formed at the top surface of the upper housing 100 to discharge heat from the controller 113 and the motor 125 .
[0029] The handle grip 111 installed at the top surface of the upper housing 110 can be rotated for being folded in no use, and a hanging groove 111 b may be formed at the lower part of the handle grip 111 a placed at the upper housing 110 for inserting and fixing a hanging protrusion 305 formed at a handle grip 306 of the cooking vessel 300 .
[0030] The control panel 112 includes function a selection button 112 a for selecting grain porridge, meat porridge, vegetable porridge or sea food porridge, a reservation button 112 b for reserving operation time, a heating button 112 c for keeping the prepared porridge warm at a predetermined temperature, a cleaning button 112 d for cleaning the appliance by itself after making the porridge, and emitting diodes 112 b ′, 112 c ′, 112 d ′ for showing the setting of the buttons 112 b , 112 c , 112 d , respectively may be installed at one side of the cleaning button 112 d , and a display 112 e on which time passed or time left during reservation, heating or making the porridge is displayed.
[0031] So as to prepare porridge, in the case where the selection button 112 a is pressed by a user, light emitting diodes 112 f indicating the grain porridge, the meat porridge, the vegetable porridge and the sea food porridge, and disposed at one side of the selection button 112 a start to generate the light sequentially, and as the selection button 112 a , the reservation button 112 b , the heating button 112 c and the cleaning button 112 d are pressed by the user, the time passed or the time left is displayed on the display 112 e.
[0032] The lower housing 120 has an upper side opened to correspond with the opened bottom side of the upper housing 110 and has a staged protrusion 121 formed at the lower side of the opened upper surface thereof, the staged protrusion 121 adapted to be coupled to a generally cylindrical motor mounting part 124 into which the motor 125 is disposed. On the outer surface of the staged protrusion 121 a ring type of insertion groove 121 a into which the upper part of the cooking vessel 300 is inserted to fix may be formed, while on the inner surface of the staged protrusion 121 a protrusion piece 128 which is installed with insertion into a protrusion step 314 formed at the outer surface of a insertion protrusion 312 that is formed at the upper part of the cooking vessel 300 may be formed, as described in the following.
[0033] The motor mounting part 124 has a rotating shaft 126 extended downwardly from the motor 125 , and the rotating shaft 126 has a pulverizing blade 127 mounted at the end portion thereof wherein the pulverizing blade 127 serves to pulverize the porridge ingredients to a predetermined size. A heater 122 may be installed extendedly downwardly at one side of the staged protrusion 121 for boiling the porridge ingredients by means of heating water into the cooking vessel 300 , and a sensor 123 may be installed at other side of the staged protrusion 121 to detect the amount of water, the temperature of the porridge ingredients and generation of bubble. An opening/closing switch 114 may be installed to detect the coupling condition of the cooking vessel 300 at the insertion groove 121 a , and a protection cover 129 made of stainless material may be mounted at the outer surface of the staged protrusion 121 and the motor mounting part 124 . The cooking vessel 300 takes a generally cylindrical shape and has an opened upper portion for mounting the driving part 100 therein. The cooking vessel 300 includes an inner tank 302 that is provided at the inside thereof, an outer tank 304 that is coupled to the outside of the inner tank 302 to thereby form an outer appearance thereof. In this case, the inner tank 302 is made of stainless metal or synthetic resin having excellent strength and heat-resistance properties with the top part open, the end of upper part of the inner tank 302 is closely contacted with the outer tank 304 to be fixed air-tightly, at on side of the open upper part a discharging groove 302 a may be formed for discharging the contents of the inner tank 302 , and the inner tank 302 may be spaced to form a volume part 303 for heat insulation. The upper surface of the outer tank 304 made from synthetic resin may be a counterpart to the lower part of the driving part 100 , and the outer tank 304 comprises a upper outer tank 310 having a ring type of insertion protrusion 312 , which is coupled with the insertion groove 121 a placed at the lower surface of the driving part 100 by inserting, a middle outer tank 320 made from stainless material and connected to the lower part of the upper outer tank 320 forming the outer surface of the outer tank 304 , and a lower outer tank 330 coupled to the lower part of the middle outer tank 320 to support the outer tank 304 as well as to stabilize the middle outer tank 320 . Coupling grooves 310 a , 330 a are formed at the lower part of the upper outer tank 310 and the upper part of the lower outer tank 330 to insert the upper part and lower part of the middle outer tank 304 , respectively, and a handle grip 306 may be secured to treat the cooking vessel 300 at the outer surface of the upper outer tank 310 and the lower outer tank 330 . A hanging protrusion 306 a may be installed over the handle grip 306 for avoiding the rotation of the driving part 100 around the cooking vessel 300 by being supported with a extension spring 306 b wherein the hanging protrusion 306 a is inserted into a hanging groove 111 b formed at the lower surface of a handle grip 111 a in the side surface of the driving part 100 . A sensor part 315 may be provided at the upper surface of a insertion protrusion 312 , which is formed on the upper surface of the upper outer tank 310 , for operating the opening-closing switch 114 in manner to be adjacent to the opening-closing switch 114 placed on the lower surface of the driving part 100 . At the both sides of the sensor 315 a dented groove 317 may be formed along the upper surface of the insertion groove 312 for discharging the vapor generated from boiling of the ingredients of the porridge contained into the inner tank 302 toward a discharging outlet 304 a and for preventing the opening-closing switch from operating at a place other than at the place of sensor 315 . On the periphery surface of the insertion protrusion 312 a protruded step 314 may be formed and a protrusion piece 128 formed at the inner surface of the insertion groove 121 a in the lower housing 120 of the driving part 100 can be inserted. The combination of the driving part 100 and the cooking part 300 will be described in detail referring to the drawings in the following.
[0034] FIG. 5 is a sectional view of the opening-closing structure of the appliance and FIG. 6 is an enlarged perspective view of an opening-closing structure of the appliance according to the present invention.
[0035] As shown in FIGS. 5 and 6 , a plurality of protrusion steps 314 may be formed the periphery surface of the insertion protrusion 312 formed on the upper surface of the upper outer tank 310 of the cooking vessel 300 , and a plurality of protrusion pieces 128 may be formed to be inserted into the protrusion steps 314 at the inner surface of the insertion groove 121 a formed at the upper housing 120 of the driving part 100 . At one side of the protrusion step 314 there may be provided with an insertion dented groove 314 ′ for inserting a portion of the protrusion piece 128 , and at one side of the protrusion step 314 there may be provided with a insertion dented groove 128 ′ for inserting a portion of the protrusion step 314 , and each insertion dented groove 314 ′, 128 ′ may be in a curved surface for ease insertion of the protrusion piece 128 and the protrusion step 314 . If the driving part 100 is rotated after be secured at the upper part of the cooking vessel 300 , the end part of the protrusion piece 128 formed at the driving part 100 can be inserted the insertion dented groove 314 ′ of the protrusion step 314 placed at the cooking vessel 300 and at same time the end part of the protrusion step 314 can be inserted into the insertion dented groove 128 ′ of the protrusion piece 128 to be pressurized by the curved surface formed at each insert dented groove 314 ′, 128 ′ and thereby the driving part 100 may be secured closely at the cooking vessel 300 . And the driving part 100 can be coupled with the cooking vessel 300 with rotation and at the same time the opening-closing switch 114 installed at the lower part of the driving part 100 may contact the sensing part 315 placed at the upper of the cooking vessel 300 and thereby the state of combination of the driving part 100 may be transmitted to the controller 113 , and thus the rotation of the driving part 100 can be avoided by inserting the hanging protrusion 306 a supported with elasticity at the upper part of the handle grip 306 of the cooking vessel 300 into the hanging groove 111 b formed at the lower part of the handle grip 111 a.
[0036] The operation procedures of the appliance according to the present invention will be disclosed as examples in the following.
[0037] FIG. 7 is a block diagram of the configuration, and FIG. 8 is a flow-chart showing the operation order of the appliance according to the present invention.
[0038] First of all, porridge ingredients like soaked rice, other grains, meat, vegetables, sea foods and a predetermined amount of water are put in the inner tank 302 of the cooking vessel 300 , and the driving part 100 is then mounted and coupled to the cooking vessel 300 . And then the control panel 112 on the top surface of the driving part 100 is manipulated by a user for operating the porridge making appliance 1 . To do this, any one of the selection button 112 a , the reservation button 112 b , the heating button 112 c and the cleaning button 112 d on the control panel 112 may be selected by the user. If the reservation button 112 b and the selection button 112 a are simultaneously pressed after the porridge ingredients and water are put in the cooking vessel 300 (at step S 110 ), the controller 113 displays the time to start the operation on the display 112 e and at that time, if the reservation button 112 b is continuously pressed, it increases or decreases the expected time for the operation to thereby display the time finally set on the display 112 e (at step S 112 ). The controller 113 senses the presence and absence of water in the cooking vessel 300 and is returned to its initial step, if it is sensed that the water is not enough or no water is therein (at step S 113 ). Then, if the reservation time elapses, the porridge making steps as will be discussed below are processed (S 114 ). If the heating button 112 c is pressed to keep the porridge after making warm in the cooking vessel 300 (at step S 120 ), the controller 113 displays the heating time on the display 112 e , and at that time, if the heating button 112 c is continuously pressed, it increases or decreases the heating time for the porridge to thereby display the time finally set on the display 112 e (at step S 122 ). The controller 113 applies power to the heater 122 to operate the heater 122 at a predetermined set temperature (at step S 126 ) such that the porridge in the cooking vessel 300 can be kept at the predetermined set temperature. After that, if the heating maintaining time elapses, the controller 113 cuts the power being supplied to the heater 122 to thereby stop the heating operation (at step S 128 ). If the cleaning button 112 d is pressed after water is poured into the cooking vessel 300 (at step S 130 ), the controller 113 applies the power to the heater 122 to boil the water in the cooking vessel 300 , and also applies the power to the motor 125 for a predetermined period of time to thereby rotate the pulverizing blade 127 (at step S 132 ), with a result that as the pulverizing blade 127 is rotated, the water in the cooking vessel 300 is rotated to thereby make the pulverizing blade 127 and the cooking vessel 300 all cleaned. If the selection button 112 a is pressed after the porridge ingredients and water are put in the cooking vessel 300 , the light emitting diodes 112 f indicating the grain porridge, the meat porridge, the vegetable porridge and the sea food porridge that are disposed at one side of the selection button 112 a start to generate the light sequentially. At that time, if a desired porridge kind is selected, the controller 113 starts to carry out the operation of making the desired porridge (S 200 to S 510 ). In this case, the controller 113 sets the heating time and the pulverizing time by the porridge ingredients in accordance with the selected porridge kinds, and based upon the set time, it starts to pulverize and heat the porridge ingredients in the cooking vessel 300 . After the selection of the desired porridge kind, the controller 113 senses the presence or absence of the water between the heater 122 and the pulverizing blade 127 of the driving part 100 , and if the presence of water is sensed, it operates the heater 122 for the predetermined period of time to heat the water in the cooking vessel 300 . At that time, the steam generated when the water is boiled is discharged through the steam discharging groove 302 a on the cooking vessel 300 . And, the controller 113 operates the motor 125 to thereby pulverize the porridge ingredients in the cooking vessel 300 by using the pulverizing blade 127 at the inside of the cooking vessel 300 and heats the pulverized mixture to thereby complete the desired porridge making operation. Hereinafter, an explanation of the process of making the porridge by using the domestic porridge making appliance of this invention will be given in detail.
[0039] FIG. 9 is a flowchart showing the process of making porridge by using the domestic porridge making appliance of this invention.
[0040] In the case where the selection button 112 a is pressed to select a desired porridge kind or where the reservation time elapses after the reservation button 112 b is pressed, the controller 113 senses the presence or absence of water in the cooking vessel 300 (at step S 602 ). If it is sensed that the water is not charged in the cooking vessel 300 , at that time, the controller 113 generates a warning sound and is then returned to its initial state. On the other hand, if it is sensed that the water is charged in the cooking vessel 300 , the controller 113 measures a temperature of the water (at step S 603 ). In this case, if the temperature of the water is higher than a temperature set therein, the controller 113 is in a stand-by stage for time set therein such that the porridge ingredients are soaked in the water for the predetermined period of time (at step S 604 ). Contrarily, if the temperature of the water is lower than the temperature set therein, the controller 113 applies the power supplied from the power supply 115 to the heater 122 to thereby operate the heater 122 (at step S 605 ). As the heater 122 is operated, the water that is charged in the cooking vessel 300 is heated and boiled, which is sensed by means of the sensor 123 . Thus, the temperature of water boiled is transmitted to the controller 113 . At that time, the controller 113 starts to carry out a heating step (at step S 610 ) wherein the operation time of the heater 122 is counted and at the same time the operation of the heater 122 is controlled. In this case, if the operation time of the heater 122 does not reach the time set therein, the controller 113 continuously applies the power to the heater 122 to keep the water boiled, and contrarily, if the operation time of the heater 122 reaches the time set therein, the controller 113 makes the heater 122 kept at a predetermined temperature for about 30 seconds and then cuts the power supply to the heater 122 to thereby stop operating the heater 122 (at step S 618 ). On the other hand, if the temperature of water does not reach the set temperature, the controller 113 continuously applies the power to the heater 122 to thereby heat the water to the set temperature (at step S 616 ). Even though the operation of the heater 122 stops by the above conditions (at step S 618 ), if the operation time of the heater 112 is shorter than the set time, the stand-by state is kept until the operation time of the heater 122 reaches the set operation time (at step S 620 ). After the heating step (at step S 610 ), the controller 113 applies the power to the motor 125 to thereby carry out a first pulverization step for the porridge ingredients in the cooking vessel 300 by using the pulverizing blade 127 mounted on the rotating shaft 126 of the motor 125 at the inside of the cooking vessel 300 (at step S 622 ). During the first pulverization step, the motor 125 is operated for about 20 seconds and has stand-by time for about 1 to 3 minutes. In this case, the operation time of the motor 125 is varied in accordance with the kinds of porridge. After the first pulverization step, the controller 113 carries out a second pulverization step where the motor 125 is operated for about 20 seconds and takes stand-by time for about 10 seconds, which is conducted repeatedly about 4 to 6 times (at step S 624 ), and then, the controller 113 takes stand-by time for about 5 minutes (at step S 626 ), thereby completing the operation of making the porridge. In this case, the heating step (step S 610 ) and the first and second pulverization steps (steps S 622 and S 624 ) may be carried out reversely or repeatedly in accordance with the porridge ingredients.
[0041] As clearly appreciated from the foregoing, there is provided a domestic porridge making appliance and a method for making porridge by using the same wherein a pulverizing means for pulverizing all kinds of grains like rice as one of main ingredients of the porridge together with various vegetables and a heating means for heating water and porridge ingredients are formed integrally with each other, thereby making it possible to prepare the porridge in a more convenient way.
[0042] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
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The present invention relates to a domestic porridge making appliance in which pulverizing means to pulverize ingredients of porridge such as various kinds of grains and vegetables, and heating means are formed in a single body for preparing porridge with ease. The present invention in which the appliance comprises a cylindrical vessel having the upper surface open for inputting predetermined amount of water and a vessel grip installed at suitable place thereof for handling; a motor having pulverizing cutters at the end of a rotation shaft capable of being embedded into the lower part of said vessel wherein the lower part may be in the form corresponding to the open upper surface of said vessel; a heat for heating said predetermined amount of water at the outer part of said milling cutters; and a driving part placed within said lower part for controlling said motor and said heater is characterized in that an insertion groove in the shape of ring is formed to fix the upper part of said vessel with insertion at the lower periphery surface of said driving part, a plurality of protrusions are formed in the shape of a curved surface at inner circumference of the upper surface of said vessel, a insertion protrusion in shape of ring is formed for inserting into said insertion groove at the upper surface of said vessel, and a projecting step has a curved surface to contact the curved surface of said protrusion formed at the inner circumference of said insertion groove at the outer circumference of said insertion protrusion. The present invention may supply means for cooking porridge in easier and more convenient way than a known appliance and also may shorten the time consumed for making porridge.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of Application Ser. No. 60/878,003, filed Dec. 28, 2006, entitled “Flat Panel Display Mounting System,” the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to television displays and more particularly relates to television mounting systems for flat panel displays.
Recently, there has been a marked growth in the popularity of flat panel displays, and in particular flat panel televisions. Flat panel televisions presently use one of two technologies, either liquid crystal or plasma display, to provide a display screen that is much thinner and lighter than traditions cathode ray televisions or projection televisions. Flat panel televisions are also versatile and that they can be placed on a stand or mounted on numerous surfaces such as a wall.
The variety and accessibility of flat panel televisions is increasing as more manufacturers enter the market and larger flat panel televisions are produced. Presently, each manufacturer of flat panel televisions offer mounting brackets, stands or other hardware that is uniquely designed to mount that particular brand of flat panel television. There are also a number of mounting systems that can be used interchangeably with different flat panel televisions, however, these mounting systems typically require a mounting plate that is specific to each unique flat panel television product.
Many of the mounting systems that are available are not versatile. These mounting systems are designed for mounting a particular flat panel television. Thus, there is a need for mounting systems that are able to mount a wide range of flat panel televisions. There's also a need for mounting systems that do not require significant man power. As is well-known to those skilled in the art, many of the mounting systems require three or more individuals to work together to mount a flat panel televisions to a wall. Thus, there remains a need for televisions mounting systems that require less man power for mounting a flat panel television to a wall. There's also a need for television mounting systems that more adequately protect the flat panel television mounting thereto. Finally, there remains a need for flat panel television mounting systems that enable the mounted flat panel television to be properly oriented for maximum viewing quality.
SUMMARY OF THE INVENTION
In one preferred embodiments of the present invention, a television mounting system includes a wall plate having an upper end, a lower end, and first and second sides extending between the upper and lower ends, and a support flange extending along the upper end of the wall plate. The wall plate may have at least one support rib integrally formed with and projecting from the wall plate. The wall plate desirably has an inner face and an outer face, and the at least one support rib projects from the inner face. The at least one support rib may include a pair of support ribs having a V-shaped configuration. A first mating flange preferably extends along the first side of the wall plate and a second mating flange preferably extends along the second side of the wall plate. The first and second mating flanges may include curved surfaces.
The wall plate may have openings extending therethrough for securing the wall plate to a surface, the openings including a pair of aligned keyhole-shaped openings extending through the wall plate and a smaller opening aligned with the pair of keyhole-shaped openings and located between the pair of keyhole-shaped openings and the upper end of the wall plate. One or more flanges, such as one or more L-shaped flanges, may project from a lower end of the wall plate. The flanges desirably have threaded openings. In certain preferred embodiments, inserts having threaded central openings may be inserted into openings in the flanges.
The television mounting system may also include a monitor plate mountable on the wall plate, the monitor plate having an inner face, an outer face, an upper end, a lower end and first and second sides extending between the upper and lower ends. A first mounting flange having a first hook may extend along the first side of the monitor plate and a second mounting flange having a second hook may extend along the second side of the monitor plate. When mounting the monitor plate on the wall plate, the first and second hooks of the mounting flanges desirably engage the first and second mating flanges on the wall plate. In one embodiment, the monitor plate has openings extending therethrough for securing the monitor plate to a television monitor. The monitor plate may also have openings extending therethrough for securing at least one expansion plate to the monitor plate.
In certain preferred embodiments, L-shaped flanges project from a lower end of the monitor plate, the L-shaped flanges have threaded openings that are alignable with the threaded openings on the wall plate when the monitor plate is mounted on the wall plate.
The at least one expansion plate desirably includes a top expansion plate having an upper end, a lower end, and at least one support hook insertable into at least one of the second openings in the monitor plate for securing the top expansion plate to the monitor plate. The at least one expansion plate may also include a bottom expansion plate having an upper end, a lower end and at least one support hook insertable into at least one of the second openings in the monitor plate for securing the bottom expansion plate to the monitor plate. The at least one support hook on the top expansion plate preferably extends toward the lower end of the top expansion plate and the at least one support hook on the bottom expansion plate preferably extends toward the lower end of the bottom expansion plate. The top expansion plate desirably includes first openings for securing the top expansion plate to the monitor plate and second openings for securing the top expansion plate to a television monitor. The bottom expansion plate desirably includes first openings for securing the bottom expansion plate to the monitor plate and second openings for securing the bottom expansion plate to a television monitor.
In certain preferred embodiments, the top expansion plate includes a pair of support arms that extend outwardly from the monitor plate, whereby each support arm has an opening for securing the support arm to a television monitor and a support rib that surrounds the opening and extends to a location adjacent the monitor plate, the support rib enhancing the structural integrity of the support arms of the top expansion plate. The bottom expansion plate may include a pair of support arms that extend outwardly from the monitor plate, whereby each support arm includes an opening for securing the support arm to a television monitor and a support rib that surrounds the opening and extends to a location adjacent the monitor plate, the rib enhancing the structural integrity of the support arms of the bottom expansion plate.
In another preferred embodiment of the present invention, a television mounting system includes a wall plate having an upper end, a lower end, and first and second sides extending between the upper and lower ends, and at least one support rib integrally formed with and projecting from the wall plate. The wall plate desirably has an inner face and an outer face, and the at least one support rib projects from the inner face. The at least one support rib preferably comprises a pair of support ribs having a V-shaped configuration.
The mounting system may also include a first mating flange extending along the first side of the wall plate, and a second mating flange extending along the second side of the wall plate. The wall plate preferably has openings extending through the wall plate for securing the wall plate to a surface, the openings including a pair of aligned keyhole-shaped openings extending through the wall plate and a smaller opening aligned with the pair of keyhole-shaped openings and located between the pair of keyhole-shaped openings and the upper end of the wall plate.
The mounting system may also include a monitor plate mountable on the wall plate, the monitor plate having an inner face, an outer face, an upper end, a lower end and first and second sides extending between the upper and lower ends, a first mounting flange having a first hook extending along the first side of the monitor plate, and a second mounting flange having a second hook extending along the second side of the monitor plate, whereby when mounting the monitor plate on the wall plate the first and second hooks of the mounting flanges engage the first and second mating flanges on the wall plate.
In another preferred embodiment of the present invention, a television mounting system includes a wall plate having an upper end, a lower end, and first and second sides extending between the upper and lower ends, a first mating flange extending along the first side of the wall plate, and a second mating flange extending along the second side of the wall plate. The mounting system desirably includes a monitor plate mountable on the wall plate, the monitor plate having an inner face, an outer face, an upper end, a lower end and first and second sides extending between the upper and lower ends. The system preferably includes a first mounting flange having a first hook extending along the first side of the monitor plate, and a second mounting flange having a second hook extending along the second side of the monitor plate. After the monitor plate has been secured to a television, the monitor plate may be mounted on the wall plate. When mounting the monitor plate on the wall plate, the first and second hooks of the mounting flanges preferably engage the first and second mating flanges on the wall plate.
The monitor plate preferably comprises first openings extending through the monitor plate for securing the monitor plate to a television monitor. The monitor plate may have second openings extending through the monitor plate for securing at least one expansion plate to the monitor plate. In certain preferred embodiments, the at least one expansion plate include a top expansion plate having an upper end, a lower end, and at least one support hook insertable into at least one of the second openings in the monitor plate for securing the top expansion plate to the monitor plate, and a bottom expansion plate having an upper end, a lower end and at least one support hook insertable into at least one of the second openings in the monitor plate for securing the bottom expansion plate to the monitor plate. The at least one support hook on the top expansion plate preferably extends toward the lower end of the top expansion plate and the at least one support hook on the bottom expansion plate preferably extends toward the lower end of the bottom expansion plate. The top expansion plate may include first openings for securing the top expansion plate to the monitor plate and second openings for securing the top expansion plate to a television monitor. Similarly, the bottom expansion plate may include first openings for securing the bottom expansion plate to the monitor plate and second openings for securing the bottom expansion plate to a television monitor.
In another preferred embodiment of the present invention, a television mounting system includes a monitor plate having openings extending therethrough, at least one expansion plate having at least one support hook insertable into one of the openings extending through the monitor plate for securing the at least one expansion plate to the monitor plate. The at least one expansion plate desirably includes a top expansion plate having an upper end, a lower end, and at least one support hook insertable into at least one of the openings in the monitor plate for securing the top expansion plate to the monitor plate, and a bottom expansion plate having an upper end, a lower end and at least one support hook insertable into at least one of the openings in the monitor plate for securing the bottom expansion plate to the monitor plate.
In one preferred embodiment of the present invention, a television mounting system includes a monitor plate having a plurality of openings extending therethrough, the plurality of openings including central openings and peripheral openings outside the central openings, and at least one expansion plate having at least one support hook insertable into one of the plurality of openings extending through the monitor plate for securing the at least one expansion plate to the monitor plate. The at least one expansion plate desirably includes a top expansion plate having an upper end, a lower end, and at least one support hook insertable into at least one of the plurality of openings extending through the monitor plate for securing the top expansion plate to the monitor plate, and a bottom expansion plate having an upper end, a lower end and at least one support hook insertable into at least one of the plurality of openings extending through the monitor plate for securing the bottom expansion plate to the monitor plate. The support hooks are preferably insertable into the peripheral openings for increasing an area covered by the top and bottom expansion plates and are insertable into the central openings for reducing the area covered by the top and bottom expansion plates.
In another preferred embodiment of the present invention, a television mounting system includes a wall plate, a tilt mechanism coupled with the wall plate for tilting to selected angles relative to the wall plate, and a monitor plate having openings extending therethrough for securing the monitor plate to a television monitor, the monitor plate being mountable on the tilt mechanism. The wall plate is desirably coupled with the tilt mechanism using fixed fasteners so that the tilt mechanism cannot be accidentally disassembled from the wall plate. The wall plate preferably has first and second sides extending between upper and lower ends thereof, the sides having elongated slots formed therein that receive one or more of the fixed fasteners. The fixed fasteners are preferably slidable in the elongated slots during tilting movement of the tilt mechanism relative to the wall plate.
The mounting system may also include at least one expansion plate securable to the monitor plate. The at least one expansion plate may include a top expansion plate having an upper end, a lower end, and at least one support hook insertable into at least one of the second openings in the monitor plate for securing the top expansion plate to the monitor plate, and a bottom expansion plate having an upper end, a lower end and at least one support hook insertable into at least one of the second openings in the monitor plate for securing the bottom expansion plate to the monitor plate. The top expansion plate may include a pair of support arms that extend outwardly from the monitor plate, whereby each support arm includes an opening for securing the support arm to a television monitor and a support rib that surrounds the opening and extends to a location adjacent the monitor plate, the rib enhancing the structural integrity of the support arms of the top expansion plate. The bottom expansion plate desirably includes a pair of support arms that extend outwardly from the monitor plate, whereby each support arm includes an opening for securing the support arm to a television monitor and a support rib that surrounds the opening and extends to a location adjacent the monitor plate, the rib enhancing the structural integrity of the support arms of the bottom expansion plate.
In another preferred embodiment of the present invention, a television mounting system includes a wall mount, a monitor plate adapter coupled with the wall mount, and a permanent linkage coupling the monitor plate adapter with the wall mount, whereby the permanent linkage enables the monitor plate adapter to selectively move relative to the wall mount. The mounting system desirably includes at least one tightening element coupled with the permanent linkage, whereby the at least one tightening element is movable to a first position for enabling movement of the monitor plate adapter relative to the wall mount and is movable to a second position for preventing movement of the monitor plate adapter relative to the wall mount.
The permanent linkage desirably includes a combination articulating and tilting link having an articulating linkage and a tilting linkage. The at least one tightening element preferably includes a first tightening knob coupled with the articulating linkage and a second tightening knob coupled with the tilting linkage. The articulating linkage desirably includes a shaft permanently connecting the wall mount and the combination articulating and tilting link. The first tightening knob is desirably coupled with the shaft. The tilting linkage desirably includes a second shaft permanently connecting the monitor plate adapter and the combination articulating and tilting link. The second tightening knob is preferably coupled with the second shaft.
The system also desirably includes a monitor plate mountable on the monitor plate adapter. The monitor plate preferably comprises mounting flanges extending along sides thereof that engage mating flanges on the monitor plate adapter. The monitor plate desirably includes a flange extending along an upper end thereof, the flange having at least one opening adapted to receive a fastener for securing the monitor plate to the monitor plate adapter. The monitor plate adapter preferably has a support ledge extending adjacent a lower end thereof and the monitor plate sits on the support ledge when the monitor plate is mounted on the monitor plate adapter. In other preferred embodiments, the monitor plate may sit on and be supported by the upper end of the monitor plate adapter, and/or the lower end of the monitor plate adapter.
In one embodiment, the system includes at least one expansion plate securable to the monitor plate. The at least one expansion plate preferably includes a top expansion plate securable to the monitor plate using one or more hooks extending from the top expansion plate and a bottom expansion plate securable to the monitor plate using one or more hooks extending from the bottom expansion plate. The system preferably includes fasteners extending through openings in the top and bottom expansion plates for securing the expansion plates to the monitor plate. The expansion plates desirably cover an area that is larger than an area covered by the monitor plate. The expansion plates preferably include openings for securing the expansion plates to a television monitor.
In one preferred embodiment, the wall mount includes a channel formed therein and a tool is insertable into the channel for storing the tool with the wall mount. The wall mount may have a ledge disposed adjacent an end of the channel for holding the tool inside the wall mount. In one embodiment, the tool is an Allen wrench having a longer section insertable into the channel and a shorter section adapted to engage the shelf on the wall mount.
The mounting system may include an articulating arm having a first end permanently coupled with the articulating linkage and a second end remote from the first end. The system may also include a second articulating arm having a first end coupled with the second end of the first arm and a second end coupled with the wall mount. The first and second articulating arms are desirably permanently connected together by a shaft for providing selective articulating movement.
In another preferred embodiment of the present invention, a television mounting system includes a wall mount, a monitor plate adapter coupled with the wall mount, and a permanent linkage including an articulating arm for permanently coupling the monitor plate adapter with the wall mount for selectively moving the monitor plate adapter relative to the wall mount. The system preferably includes at least one tightening element coupled with the permanent linkage, whereby the at least one tightening element is movable to a first position for enabling movement of the monitor plate adapter relative to the wall mount and is movable to a second position for preventing movement of the monitor plate adapter relative to the wall mount. The permanent linkage desirably includes a second articulating arm for permanently coupling the monitor plate adapter with the wall mount, whereby the first and second articulating arms are permanently connected together.
In a preferred embodiment of the present invention, a television mounting system includes a wall mount, a monitor plate adapter coupled with the wall mount, and a permanent linkage coupling the monitor plate adapter with the wall mount for selectively moving the monitor plate adapter relative to the wall mount. The permanent linkage desirably includes a cable management system that is adapted for guiding cables between the wall mount and the monitor plate adapter. The permanent linkage preferably allows selective articulating and tilting movement of the monitor plate adapter relative to the wall mount. The system desirably includes at least one tightening element coupled with the permanent linkage, whereby the at least one tightening element is movable to a first position for allowing movement of the monitor plate adapter relative to the wall mount and is movable to a second position for fixing the position of the monitor plate adapter relative to the wall mount.
In one preferred embodiment, the cable management system desirably includes a first housing having a first channel for guiding a first cable and a second housing having a second channel for guiding a second cable, whereby the first and second channels are spaced from one another for minimizing signal interference between the first and second cables. The first and second cables may be selected from the group consisting of an audio cable, a video cable and a power cable. The system desirably includes a first cap securable over the first channel for containing the first cable in the first housing and a second cap securable over the second channel for containing the second cable in the second housing. The first housing desirably has a first side wall and a second side wall and the first channel preferably extends between the first and second side walls, the first and second side walls including aligned slots. Pins may be inserted into the aligned slots in the first and second side walls of the first housing. The first housing has a longitudinal axis and the inserted pins desirably extend in a direction that traverses the longitudinal axis. The pins are preferably engageable with the first cable for maintaining the first cable in the first channel of the first housing.
In one embodiment, the aligned slots have an L-shape, and the pins are advanced into a short leg of the L-shaped slot when seated in the aligned slots. The first cap may have an underside having fingers that are insertable into a long leg of the L-shaped slot for holding the pins in the short leg of the L-shaped slot. The first cap preferably forms a friction fit with the first housing.
The system may also include a second housing having a first side wall and a second side wall and the second channel extends between the first side wall and the second side wall. The first and second side walls of the second housing desirably include aligned slots. Pins are desirably insertable into the aligned slots in said first and second side walls of the second housing. The second housing has a longitudinal axis and the inserted pins preferably extend in a direction that traverses the longitudinal axis. The pins are engageable with the second cable for maintaining the second cable in the second channel of the second housing. The aligned slots of the second housing preferably have an L-shape, whereby the pins are advanced into a short leg of the L-shaped slot when seated in the aligned slots. The second cap preferably has an underside having fingers that are insertable into a long leg of the L-shaped slot for holding the pins in the short leg of the L-shaped slots of the second housing. The second cap desirably forms a friction fit with the second housing.
In certain preferred embodiments, the cable management system may have only one housing for directing/holding wires. In other embodiments, the cable management system may have one housing that holds wires and a second housing that does not hold wires.
The system may also include a monitor plate mountable on the monitor plate adapter. The monitor plate desirably includes mounting flanges extending along sides thereof that engage mating flanges on the monitor plate adapter. The monitor plate may include a flange extending along an upper end thereof, the flange having at least one opening adapted to receive a fastener for securing the monitor plate to the monitor plate adapter. The monitor plate adapter desirably has a support ledge extending adjacent a lower end thereof and the monitor plate sits on the support ledge when the monitor plate is mounted on the monitor plate adapter.
The television mounting system may also include at least one expansion plate securable to the monitor plate. The at least one expansion plate preferably includes a top expansion plate securable to the monitor plate using one or more hooks extending from the top expansion plate and a bottom expansion plate securable to the monitor plate using one or more hooks extending from the bottom expansion plate. Fasteners, such as screws, may extend through openings in the top and bottom expansion plates for securing the expansion plates to the monitor plate. The expansion plates desirably cover an area that is larger than an area covered by the monitor plate. The expansion plates include openings for securing the expansion plates to a television monitor.
The wall mount of the television mounting system may include a channel formed therein whereby a tool is insertable into the channel for storing the tool with the wall mount. The wall mount may also include a ledge disposed adjacent an end of the channel for holding the tool inside the wall mount. The tool may be an L-shaped instrument commonly referred to as an Allen wrench having a longer section insertable into the channel and a shorter section adapted to engage the shelf on the wall mount.
In still another preferred embodiment of the present invention, a television mounting system includes a wall mount, a monitor plate adapter coupled with the wall mount, and a linkage coupling the monitor plate adapter with the wall mount for selectively moving the monitor plate adapter relative to the wall mount, the permanent linkage including a cable management system that is adapted for guiding cables between the wall mount and the monitor plate adapter. The linkage desirably allows selective articulating and tilting movement of the monitor plate adapter relative to the wall mount. The cable management system preferably includes a first housing having a first channel for guiding a first cable and a second housing having a second channel for guiding a second cable, whereby the first and second channels are spaced from one another for minimizing signal interference between the first and second cables. The first and second cables may include an audio cable, a video cable or a power cable.
A first cap is desirably securable over the first channel for containing the first cable in the first housing and a second cap is securable over the second channel for containing the second cable in the second housing. The first housing preferably has a first side wall and a second side wall and the first channel extends between the first and second side walls, the first and second side walls including aligned openings extending therethrough. Pins are desirably insertable into the aligned openings in the first and second side walls of the first housing. The first housing has a longitudinal axis and the pins are desirably inserted in the aligned openings in a direction that traverses the longitudinal axis. The pins are preferably engageable with the first cable for maintaining the first cable in the first channel of the first housing. The first cap desirably forms a friction fit with the first housing.
The system also desirably includes the second housing having a first side wall and a second side wall with the second channel extending between the first side wall and the second side wall, the first and second side walls of the second housing including aligned openings. Pins are preferably insertable into the aligned openings in the first and second side walls of the second housing. The second housing has a longitudinal axis and the inserted pins preferably extend in a direction that traverses the longitudinal axis. The pins are desirably engageable with the second cable for maintaining the second cable in the second channel of the second housing. The second cap desirably forms a friction fit with the second housing.
These and other preferred embodiments of the present invention will be described in more detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1C show a wall plate for a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIGS. 2A-2C show a monitor plate for a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIG. 3 shows the wall plate of FIG. 1A juxtaposed with the monitor plate of FIG. 2A .
FIGS. 4A-4F show the wall plate and the monitor plate of FIG. 3 assembled together.
FIGS. 5A and 5B show the wall plate and the monitor plate of FIG. 3 assembled together.
FIGS. 6A and 6B show a top expansion plate for a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIGS. 7A and 7B show a bottom expansion plate of a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIG. 8A shows the top and bottom expansion plates of FIGS. 6A and 7A assembled with the monitor plate of FIGS. 2A-2C .
FIG. 8B shows a front view of the top and bottom expansion plates of FIG. 8A in an expanded configuration.
FIG. 8C shows a rear view of FIG. 8B .
FIGS. 9A-9B show a top large expansion plate and a bottom large expansion plate attached to a monitor plate, in accordance with certain preferred embodiments of the present invention.
FIGS. 10A-10B show an exploded view of a tiltable mount for a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIGS. 11A-11F show the tiltable mount of FIGS. 10A-10B after assembly.
FIG. 12A shows a front perspective view of the tiltable mount shown in FIG. 11A .
FIG. 12B shows a rear perspective view of the tiltable mount shown in FIG. 11B .
FIG. 13 shows a top perspective view of the tiltable mount shown in FIG. 12A .
FIG. 14A shows the top and bottom expansion plates of FIGS. 6A and 7A attached to the tiltable mount shown in FIG. 12A .
FIG. 14B shows the top and bottom expansion plates of FIG. 14A in an expanded configuration.
FIGS. 15A and 15B show a tilt and pan mount of a television mounting system, in accordance with certain preferred embodiments of the present.
FIGS. 16A and 16B show exploded views of the tiltable and pan mount of FIGS. 15A and 15B .
FIGS. 17A-17F show other views of the tilt and pan mount of FIG. 15A .
FIG. 18A shows a front perspective view of a wall mount of the tiltable and pan mount of FIG. 15A .
FIG. 18B shows a rear perspective view of the wall mount of FIG. 18A .
FIG. 19A shows a cross sectional view of the tilt and pan mount of FIG. 18A .
FIG. 19B shows a tightening knob for use with the tilt and pan mount of FIG. 19A .
FIG. 20A shows a perspective view of a tilt and pan mount of FIG. 15A having top and bottom expansion plates secured thereto.
FIG. 20B shows the tilt and pan mount of FIG. 20A with the top and bottom expansion plates in an expanded configuration.
FIG. 21 shows a side view of a tilt, pan and cantilever mount for a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIGS. 22A-22C show a side view of a tilt, pan and articulating mount for a television mounting system, in accordance with certain preferred embodiments of the present invention.
FIG. 23 shows an exploded view of a tilt, pan and articulating mount for television mounting system, in accordance with certain preferred embodiments of the present invention.
FIG. 24 shows the tilt, pan and articulating mount of FIG. 23 in an assembled configuration.
FIG. 25 shows another view of the tilt, pan and articulating mount shown in FIG. 24 .
FIG. 26 shows a rear view of a wall mount of the tilt, pan and articulating mount shown in FIG. 24 .
FIG. 27 shows a cross sectional view of the tilt, pan and articulating mount shown in FIG. 25 .
FIG. 28 shows a top view of a cable management system of the tilt, pan and articulating mount shown in FIGS. 24 and 25 .
FIG. 29 shows a permanent linkage system for the tilt, pan and articulating mount shown in FIG. 25 .
FIG. 30 shows other views of a permanent linkage system for the tilt, pan and articulating mount shown in FIG. 25
FIG. 31A shows top and bottom expansion plates attached to the tilt, pan and articulating mount shown in FIG. 24 .
FIG. 31B shows the top and bottom expansion plates of FIG. 31A in expanded configuration.
DETAILED DESCRIPTION
Referring to FIG. 1A , in accordance with certain preferred embodiments of the present invention, a wall plate 100 for a television mounting system includes an upper end 102 , a lower end 104 , a first side 106 and a second side 108 . The wall plate if preferably made of a rigid material such as metal. The wall plate 100 includes ribs 110 formed therein. The ribs strengthen the wall plate and prevent the sides 106 , 108 of the wall plate from collapsing or bending toward one another when a load is applied to the wall plate.
Referring to FIGS. 1A-1C , the wall plate includes a first mating flange 112 provided adjacent the first side 106 of wall plate 100 . The wall plate 100 also includes a second mating flange 114 provided adjacent the second side 108 of the wall plate. In preferred embodiments, the mating flanges 112 , 114 are curved for adding strength to the flanges. The mating flanges 112 , 114 preferably extend between the upper end 102 and the lower end 104 of the wall plate. As will be described in more detail below, the mating flanges 112 , 114 mesh with mounting flanges on a monitor plate for forming a section of a television mounting system.
Referring to FIGS. 1A and 1B , the wall plate includes a first keyhole opening 116 and a second keyhole opening 118 . After securing elements such as screws have been anchored in a wall, the first and second keyhole openings 116 , 118 may be used for securing the wall plate to a wall. The wall plate 100 also includes a circular opening 120 that is aligned with the first and second keyhole openings 116 , 118 . The circular opening 120 is smaller than the keyhole openings 116 , 118 and is adapted to receive a fastener such as a screw for mounting the wall plate to a wall. The circular opening 120 is smaller than the keyhole openings so that it can better withstand stresses that are typically present at upper ends of base plates or mounting plates. The wall plate 100 also includes supplemental openings 122 that may also be used for anchoring the wall plate to a wall or a surface.
FIG. 1A shows the surface of the wall plate 100 that is abutted against a wall, with the ribs 110 projecting away from the wall so that the wall plate may be placed flush with the wall. FIG. 1B shows the face of the wall plate 100 that faces away from the wall with the ribs 110 projecting away from the wall.
Referring to FIGS. 1B and 1C , the wall plate includes a pair of L-shaped flanges 124 A, 124 B that project from the lower end 104 of the wall plate. The flanges 124 A, 124 B include central openings 125 that are adapted to receive threaded inserts 126 that are press fit into the openings 125 . The threaded inserts 126 , which are shown in FIGS. 1A and 3 , are adapted to receive threaded fasteners 164 , such as screws, bolts or the like (see FIG. 3 ).
Referring to FIGS. 2A-2C , in certain preferred embodiments of the present invention, a television mounting system includes a monitor plate 130 having an upper end 132 , a lower end 134 , a first side 136 and a second side 138 . Referring to FIG. 2C , the monitor plate 130 includes an inner face 140 that opposes the wall plate shown in FIGS. 1A-1C and an outer face 142 that normally opposes the back or rear of a television monitor.
Referring to FIGS. 2A-2C , the monitor plate 130 includes a first mounting flange 144 extending along the first side 136 of the monitor plate and a second mounting flange 146 extending along the second side 138 of the mounting plate. As shown in FIG. 2A , the first mounting flange 144 includes a first hook 148 and the second mount flange 146 includes a second hook 150 . The first and second hooks 148 , 150 are adapted to engage upper ends of the mating flanges 112 , 114 of the wall plate 100 shown in FIG. 1B .
Referring to FIGS. 2A and 2B , the monitor plate 130 includes a series of expansion plate openings 152 extending therethrough. As will be described in more detail below, the expansion plate openings 152 enable the expansion plates (not shown) to be attached to the monitor plate. The monitor plate 130 also includes supplemental expansion plate openings 154 that may also be used for attaching the expansion plates to the monitor plate. The monitor plate 130 also includes an inner set of television mounting openings 156 A- 156 D that are used for mounting a television monitor to the monitor plate 130 . In certain preferred embodiments, fasteners such as screws are passed through the inner set of television mounting openings 156 - 156 D and into threaded openings located at the rear of a television monitor. In certain preferred embodiments, the inner set of television mounting openings 156 A- 156 D are used for providing a 75 mm by 75 mm mounting pattern.
Referring to FIGS. 2A and 2B , the mounting plate 130 also includes an outer set of television mounting openings 158 A- 158 D that are used for mounting a larger sized television monitor to the mounting plate. In one particular preferred embodiment, the outer set of television mounting openings 158 A- 158 D are used for a 100 by 100 mm mounting pattern.
Referring to FIG. 2A , the monitor plate 130 includes L-shaped flanges 160 A, 160 B that project from the lower end 134 of the monitor plate 130 . Threaded inserts 162 are desirably press fit into the openings in the L-shaped flanges 160 A, 160 B. As will be described in more detail below, the L-shaped flanges 160 A, 160 B are used for connecting the monitor plate 130 to the wall plate 100 shown in FIGS. 1A-1C .
FIG. 3 shows the wall plate 100 of FIGS. 1A-1C being juxtaposed with the monitor plate 130 of FIGS. 2A-2C . Before assembling the wall plate 100 and the monitor plate 130 together, the inner face 127 (shown in FIG. 1C ) of the wall plate 100 is juxtaposed with the inner face 140 of the monitor plate. The first and second mounting flanges 144 , 146 on the monitor plate 130 are coupled with upper ends of the mating flanges 112 , 114 of the wall plate. After the mounting flanges are coupled with the mating flanges, the monitor plate is slid toward the lower end 104 of the wall plate until the hooks 148 , 150 on the monitor plate engage the upper ends of the mating flanges 112 , 114 . After the hooks 148 , 150 are firmly seated on the upper ends of the mating flanges 112 , 114 , threaded fasteners 164 may be passed through the threaded inserts press fit into the L-shaped flanges on the respective wall plate 100 and monitor plate 130 . In certain preferred embodiments, the threaded fasteners 164 may be at least partially coupled with the threaded inserts on the L-shaped flanges of the wall plate 100 before the monitor plate 130 is assembled with the wall plate. As a result, the threaded fasteners will be pre-aligned with the openings in the threaded inserts once the monitor plate is coupled with the wall plate. In this particular embodiment, the threaded fasteners may be fully tightened after the wall plate 100 and the monitor plate 130 are coupled together for securing the wall plate 100 and the monitor 130 to one another.
FIGS. 4A-4F show the monitor plate 130 assembled with the wall plate 100 . As shown in FIGS. 4E and 4F , the upper end 102 of the wall plate 100 includes a top flange 166 that adds strength to the upper end of the wall plate and prevents the wall plate from bending forward under load. As shown in FIGS. 4C and 4D , the mating flanges 112 on the wall plate 100 are captured within the mounting flanges 144 , 146 on the monitor plate 130 . Referring to FIG. 4B , the first and second hooks 148 , 150 on the monitor plate engage the upper ends of the mating flanges 112 , 114 on the wall plate 100 .
FIG. 5A shows monitor plate 130 assembled with wall plate 100 . Threaded fasteners 164 extend through the threaded inserts press fit into the L-shaped flanges of the respective wall plate and monitor plate for securing the wall plate and monitor together. FIG. 5B shows the assembly of FIG. 5A with reinforcing ribs 110 being provided on the wall plate 100 . The reinforcing ribs 110 provide strength to the wall plate under load. The upper end 102 of the wall plate includes a top flange 166 that also provides strength to the wall plate under load. The projecting ribs 110 and the top flange 166 prevent the wall plate 100 from bending or folding under load. As a result, the ribs 110 and the top flange 166 enable the wall plate to carry more weight than is possible with prior art mounting systems.
Although the present invention is not limited by any particular theory of operation, it is believed that providing mounting flanges 144 and 146 on the monitor plate 130 that couple with mating flanges of the wall plate enables the assembly of the wall plate 110 and the monitor plate 130 to carry additional load. This is because the hooks 148 , 150 on the monitor plates 130 engage the upper ends of the mating flanges on the wall plate 100 . Further structural support is provided by the L-shaped flanges of the respective wall plate and monitor plate that are connected together by passing a threaded fastener through the threaded inserts positioned on the L-shaped flanges.
Referring to FIGS. 6A and 6B , in one preferred embodiment of the present invention, a television mounting system includes a top expansion plate 170 having a first face 172 that normally faces the back of a television monitor and a second face 174 that normally faces a monitor plate, such as the monitor plate shown and described above in FIGS. 2A-2C . The top expansion plate 170 includes openings 176 that receive fasteners such as screws for securing the top expansion plate to the monitor plate. The top expansion plate 170 shown in FIGS. 6A and 6B has five openings 176 that are arranged in a particular configuration. One or more of the openings 176 may be utilized depending upon the size of the television monitor secured to the top expansion plate. The top expansion plate 170 also includes supplemental openings 178 that are also used for securing a television monitor to the top expansion plate. In certain preferred embodiments, the supplemental openings 178 enable a larger sized television monitor to be secured to the top expansion plate. One or more of the openings 176 , 178 may include an elongated or slotted opening 180 which provides flexibility for securing a television monitor to the top expansion plate. This may be useful in instances where a circular opening does not exactly align with a mounting opening on a television monitor.
As shown in FIGS. 6A and 6B , the top expansion plate 170 also includes hooks 182 that project from the second face 174 of the top expansion plate 170 and extend toward a lower end 184 of the top expansion plate. As will be described in more detail below, the hooks 182 preferably fit in the expansion plate openings 152 ( FIG. 2A ) of the monitor plate for providing enhanced weight bearing support for the top expansion plate.
Referring to FIGS. 7A and 7B , in certain preferred embodiments, the television mounting system also preferably includes a bottom expansion plate 186 including an upper end 188 and a lower end 190 . The bottom expansion plate 186 includes first openings 192 that are adapted to receive fasteners such as screws for securing the bottom expansion plate 186 to the rear of a television monitor. Fasteners may be passed through one or more of the first openings 192 depending upon the size of the television monitor and/or the mounting pattern on the rear of the television monitor. The bottom expansion plate 186 also includes second openings 194 which may be utilized for larger configurations and/or larger television monitors. Bottom expansion plate 186 has a first face 196 that confronts the back of the television monitor and a second face 198 that confronts the monitor plate when attached thereto. The bottom expansion plate 186 also preferably includes hooks 200 that project from the second face 198 and extend toward the lower end 190 thereof. The hooks 200 are preferably inserted into the expansion plate openings 152 ( FIG. 2A ) on the monitor plate for enhancing the load bearing capabilities of the bottom expansion plate.
FIG. 8A shows the top expansion plate 170 and the bottom expansion plate 186 secured to the monitor plate 130 ( FIG. 5A ). Although not shown, fasteners are inserted into the openings 176 , 192 of the expansion plates for securing the expansion plates to the monitor plate. In addition, the hooks 182 , 200 fit into the expansion plate openings in the monitor plate for supporting the expansion plate and enhancing the load bearing capabilities of the expansion plates. In FIG. 8A , the top and bottom expansion plates 170 , 186 are attached to the monitor plate in a first configuration. In one particular preferred embodiment, the attachment of the top and bottom expansion plates to the monitor plate provides a 200×100 mm configuration for supporting a television monitor having that particular size. However, different openings on the top and bottom expansion plates 170 , 186 may be used for supporting television monitors having a different (e.g., larger) sizes.
FIG. 8B shows the top and bottom expansion plates 170 , 186 secured to the monitor plate 130 in an expanded configuration. The hooks 182 , 200 are inserted into a different set of openings closer to the upper and the lower end of the monitor plate. One or more fasteners are passed through the openings 176 , 192 in the expansion plates for securing the expansion plates to the monitor plate.
FIG. 8C shows a rear side view of the top and bottom expansion plates 170 , 186 attached to the monitor plate 130 . The hooks 182 on the top expansion plate 170 extend through expansion plate openings 152 in the monitor plate 130 for supporting the top expansion plate 170 . The hooks 200 on the bottom expansion plate 186 extend through other expansion plate openings 152 on the monitor plate 130 for supporting the bottom expansion plate. Fasteners 202 such as screws extend through openings in the monitor plate 130 and openings in the respective top and bottom expansion plates 170 , 186 for securing the expansion plates to the monitor plates. Locking nuts may be coupled with the hooks. More or less fasteners 202 than shown in FIG. 8C may be utilizing for securing the expansion plates to the monitor plates. In FIG. 8C the top and bottom expansion plates are secured to the monitor plate in an expanded configuration. If a smaller configuration such as the configuration shown in FIG. 8A is desired, the hooks 182 , 200 of the respective expansion plates are secured in the centrally located expansion plate openings 152 A, 152 B on the monitor plate 130 .
Referring to FIGS. 9A-9C , in accordance with certain preferred embodiments of the present invention, a large top expansion plate 204 and a large bottom expansion plate 206 may be secured to the monitor plate 130 shown and described above in FIGS. 2A-2C . Referring to FIG. 9A , the large top expansion plate 204 includes hooks 208 located in a central, monitor plate mounting area 210 . The hooks 208 are adapted to pass through expansion plate openings in the monitor plate for securing the large top expansion plate 204 to the monitor plate. The large top expansion plate 204 also includes a first arm 212 and a second arm 214 extending from the central, monitor plate mounting area 210 . The first arm 212 includes at least one opening 216 through which a fastener may be passed for securing a television monitor to the first arm 212 . The first arm 212 also includes a rib 218 that extends around the opening 216 and inwardly to an area adjacent to the central, monitor plate mounting area 210 . Although the present invention is not limited by any particular theory of operation, it is believed that the rib 218 enhances the strength of the first arm 212 at certain stress points such as stress points located around the opening 216 and in the area around the central, monitor plate mounting area 210 . Laboratory studies have shown that some of the greatest load stresses occur around the opening 216 and in the area where the arm 212 extends to the central, monitor plate mounting area 210 . Thus, providing a rib 218 on the arm 212 will strengthen the arm and provide a reliable structure for handling the stresses under load.
The second arm 212 of the large top expansion plate 204 has one or more openings 220 for receiving a fastener for fastening a television monitor to the second arm 214 . Second arm 214 also includes a rib 222 similar to the rib 218 . Rib 222 also enhances the strength of the second arm as described above with respect to the rib on the first arm 212 .
The assembly shown in FIG. 9A also includes the large bottom expansion plate 206 including first arm 224 having at least one opening 226 for receiving a fastener and a rib 228 . The large bottom expansion plate 206 also includes a second arm 230 having one or more opening 232 and a rib 234 . The large bottom expansion plate 206 also includes hooks 236 that pass through openings in the monitor plate for supporting the large bottom expansion plate on the monitor plate.
Referring to FIG. 9B , when the large top expansion plate 204 is assembled with the monitor plate 130 , the hooks 208 on the large top expansion plate pass through some of the expansion plate openings in the monitor plate 130 . Similarly, when the large bottom expansion plate 206 is assembled with the monitor plate 130 , the hooks 236 on the large bottom expansion plate pass through some of the openings in the monitor plate 130 . Preferably, openings 216 , 220 , 226 and 232 on the respective large top and bottom expansion plates are aligned with openings on a television monitor. Fasteners may pass through the openings 216 , 220 , 226 and 232 for securing the respective large top and bottom expansion plates to a television monitor. After the expansion plates are secured to the television, the television, the top and bottom expansion plates 204 , 206 and the monitor plate 130 secured thereto may be attached to a wall plate similar to the wall plate shown and described above in FIGS. 1A-1C .
Referring to FIGS. 10A and 10B , in certain preferred embodiments of the present invention, a television mounting system includes a tiltable mount 298 having a wall plate 300 with an upper end 302 , a lower end 304 , a first side 306 and a second side 308 . The wall plate 300 includes ribs 310 formed therein that enhance the strength of the wall plate under load. Wall plate 300 also includes a top flange 366 that further enhances the strength of the wall plate under load. The wall plate 300 includes opening similar to the openings shown and described above in the embodiment shown in FIGS. 1A-1C . Referring to FIG. 10A , the wall plate 300 includes a first keyhole opening 316 and a second keyhole opening 318 . After fasteners are secured to a wall, the first and second keyhole openings 316 , 318 may be used for mounting the wall plate 300 to the wall. The wall plate 300 also includes an additional opening 320 aligned with the first and second keyhole openings. The additional opening 320 also receives a fastener for mounting the wall plate 300 to a wall.
Referring to FIGS. 10A and 10B , the wall plate 300 also includes supplemental openings 322 that may also be used for mounting the wall plate 300 to a wall. Although a particular pattern of supplemental openings 322 is shown, the pattern may be modified and include more or less than the number of openings shown in the drawing figures.
The first side 306 of the wall plate 300 includes an elongated slot 323 . Similarly, the second side 308 of the wall plate 300 includes an elongated slot 325 . As will be described in more detail below, the elongated slots 323 , 325 enable a tilting mechanism to slide along the slots 323 , 325 to enable the tilting mechanism to tilt relative to the wall plate 300 .
Referring to FIGS. 10A-10B , the television mounting system also includes a monitor plate 330 that is preferably similar to the monitor plate shown and described above in FIGS. 2A-2C . The tilting mount 298 also preferably includes a tilt mechanism 380 including a first side 382 having a first mating flange 384 and a second side 386 having a second mating flange 388 . The mounting flanges 344 , 346 on the monitor plate 330 are slideable over the mating flanges 384 , 388 on the tilt mechanism 380 . The hooks 348 , 350 on the mounting flanges preferably engage upper ends of the mating flanges 384 , 388 on the tilt mechanism 380 for coupling the monitor plate 330 with the tilt mechanism 380 .
Referring to FIG. 10A , the lower end of the monitor plate 330 includes L-shaped flanges 360 that are preferably aligned with opposing flanges 390 on the tilt mechanism 380 . The flanges 390 include one or more openings 392 that are preferably aligned with the openings on the L-shaped flanges 360 of the monitor plate. Fasteners may be passed through the openings for securing the L-shaped flanges 360 of the monitor plate 330 with the flanges 390 of the tilt mechanism 380 .
The tilt mechanism 380 is assembled with the wall plate 300 by aligning openings 327 , 329 at the respective first and second sides 306 , 308 of the wall plate 300 with openings 394 , 396 formed in the sides of the tilt mechanism. Thus, opening 327 of the wall plate is aligned with opening 396 of the tilt mechanism, and opening 329 of the wall plate is aligned with opening 394 of the tilt mechanism. A first fastener may be passed through the aligned openings 327 and 396 and a second fastener may be passed through the aligned openings 329 and 394 . Similarly, the openings at an upper end of the tilt mechanism may be aligned with the slots 323 , 325 in the wall plate 300 . Fasteners may also be passed through these aligned openings. The elongated slots 323 , 325 enable the tilt mechanism 380 to tilt relative to the wall plate.
In order to mount a television monitor to a wall, the wall plate 300 is first secured to a wall as described above. The tilt mechanism 380 is then assembled with the wall plate 300 . As noted above, due to the elongated slots 323 , 325 provided in a wall plate, the tilt mechanism 380 is able to tilt relative to the wall plate 300 . The monitor plate 330 is then attached to the rear surface of a television monitor by passing fasteners through one or more openings of the monitor plate and into mounting holes in the television monitor. After the monitor plate is attached to the television monitor, the television monitor and the attached monitor plate are coupled with the tilt mechanism 380 by sliding the mounting flanges 344 , 346 of the monitor plate over the mating flanges 384 , 388 of the tilt mechanism.
FIGS. 11A-11F show the tilt mount 298 , after the monitor plate 330 has been coupled with the wall plate 300 . The upper fasteners 335 , when untightened, are able to slide within slots 323 , 325 . This enables the monitor plate 330 and the tilt mechanism 380 to tilt relative to the wall plate 300 . When a preferred angle of tilt has been obtained, the upper fasteners 335 may be tightened for securing the monitor plate 330 at a preferred angle or orientation relative to the wall plate. Lower fasteners 337 may also be loosened and tightened for selectively enabling the monitor plate 330 to be tilted and secured in a preferred orientation.
FIG. 12A shows a front perspective view of the tilt mount 298 . Although not shown, in preferred embodiments, a television monitor is attached to the monitor plate 330 prior to attachment of the monitor plate to the tilt mechanism (not shown) and the wall plate 300 . FIG. 12B shows a rear perspective view of the tilt mount 298 including wall plate 300 that is preferably attached to a wall. As noted above, the wall plate 300 includes one or more ribs 310 and a top flange 366 extending along an edge of the wall plate 300 . The ribs 310 and the top flange 366 enhance the strength of the wall plate.
FIG. 13 shows a top perspective view of the tilt mount 298 shown in FIGS. 11A-11F and 12 - 12 B. The tilt mount 298 includes wall plate 300 , tilt mechanism 380 and monitor plate 330 coupled with tilt mechanism 380 . The tilt mount 298 includes upper fasteners 335 that pass through the slots (not shown) in the sides of the wall plate 300 . In one embodiments, the inner ends of the fasteners include fixed nuts 339 secured thereto that cannot be removed from the inner ends of the upper fasteners 335 . This structure creates a permanent unbreakable linkage between the wall plate 300 and the tilt mechanism 380 . Similarly, the lower fasteners 337 may also include fixed nuts 341 secured to inner ends thereof, which form a permanent, unbreakable connection between the tilt mechanism 380 and the wall plate 300 . The fixed nuts 339 , 341 prevent unintentional disassembly of the tilt mount 298 so that the structure will not collapse by loosening the upper and lower fasteners 335 , 337 . Without the fixed nuts 339 , 341 , it may be possible for an individual to loosen fasteners, which could result in the mounting system collapsing and a television monitor crashing to the floor. Thus, the fixed nuts 339 , 341 provide a reliable mechanism for preventing accidental damage to a television monitor. In other embodiments, the fixed nuts may be replaced by a C-clip provided over the end of the fastener so as to prevent unintentional disassembly of the tilt mount. A permanent unbreakable linkage may also be created by deforming the inner ends of the fasteners so that the fasteners may not be removed. In other embodiments, any type of fastening element may be used that makes disassembly of the tilting mechanism from the wall plate very difficult or nearly impossible.
As shown in FIG. 13 , the openings of the L-shaped flanges on the monitor plate 330 are aligned with the openings on the flanges on the tilt mechanism 380 . Fasteners such as screws may be passed through the aligned openings for securing the monitor plate 330 to the tilt mechanism 380 . Threaded inserts may be press fit into the opening in the flanges and used for pre-aligning the fasteners with the openings in the flanges. In addition, the mating flanges on the tilt mechanism 380 are captured within the mounting flanges 344 , 346 on the monitor plate 330 .
FIG. 14A shows a top expansion plate 370 and a bottom expansion plate 386 secured to a monitor plate of the tilt mechanism shown in FIGS. 12A-12B . In FIG. 14A , the top and bottom expansion plates 370 , 386 are attached to the tilt mount 298 in a first configuration that may be a 200×100 mm configuration.
FIG. 14B shows the top expansion plate 370 and the bottom expansion plate 386 secured to the monitor plate 330 in an expanded configuration. In certain preferred embodiments, the expanded configuration may be a 200×200 mm configuration.
Referring to FIGS. 15A and 15B , in further preferred embodiments of the present invention, a television mounting system includes a tilt and pan mount 400 . The tilt and pan mount 400 includes a wall mount 402 that is attached to a wall, a monitor plate adapter 404 and a linkage 406 that couples the monitor plate adapter with the wall mount. As will be described in more detail below, the linkage 406 enables the monitor plate adapter to pan and tilt relative to the wall mount 402 .
Referring to FIGS. 16A and 16B , the tilt and pan mount 400 includes the wall mount 402 having a first face 408 that is abutted against a wall and a second face 410 that preferably faces away from the wall. The wall mount 402 also includes an upper end 410 and a lower end 412 . The wall mount has one or more openings 414 extending from the first face 408 to the second face 410 . Fasteners may be passed through the openings 414 for securing the wall mount to a wall. Referring to FIG. 16A , the lower end 412 of the wall mount 402 includes a ledge 416 that supports a portion of an Allen wrench 418 . Referring to FIG. 16B , an elongated groove or slot 420 is formed in the rear face 408 of the wall mount 402 . When the Allen wrench 418 is rotated in a certain orientation, the elongated shaft of the Allen wrench 418 may be slid into the groove 420 . Once the elongated shaft of the Allen wrench is completely inserted into the groove 420 , the shorter section 422 of the Allen wrench may be rotated so that it sits atop the ledge 416 . The above described structure provides a storage location for the Allen wrench 418 so that it may be continuously stored with the tilt and pan mount and easily accessed when needed for adjusting the tilt and pan mount.
Referring to FIG. 16A , after fasteners have been passed through the openings 414 for securing the wall mount 402 to a wall, plugs 424 may be press fit over the openings so as to provide an aesthetically pleasing appearance for the wall mount.
The wall mount 402 has an articulating link 426 projecting from the front face 410 thereof. The articulating link 426 includes an opening 428 adapted to receive a shaft 430 . The shaft 430 preferably fits within the opening 428 and is able to rotate within the opening 428 for providing a panning motion for the monitor plate adapter 404 .
Referring to FIGS. 16A and 16B , an upper end of the shaft 430 includes a tilt and pan link 432 attached thereto. The tilt and pan link 432 is preferably attached to the upper end of the shaft 430 and rotates simultaneously with the shaft. The tilt and pan link 432 includes an opening 434 that is preferably aligned with an opening 436 on a tilt link 438 attached to a back side of monitor plate adapter 404 . During assembly, a second shaft 440 is passed through aligned openings 434 , 436 for coupling the monitor plate adapter 404 with the tilt and pan link 432 . The second shaft 440 enables the monitor plate adapter 404 to tilt relative to the tilt and pan link 432 . The above-described linkage assembly enables the monitor plate adapter 404 to both pan and tilt relative to the wall plate 402 .
The tilt and pan mount 400 also includes a monitor plate 442 that may be assembled with the monitor plate adapter 404 . The monitor plate 442 includes an upper end 444 and a lower end 446 . The upper end 444 includes a top flange 448 having openings for 450 for receiving fasteners 452 . The openings 450 are preferably aligned with openings 454 provided at an upper end of the monitor plate adapter. The monitor plate adapter 442 preferably includes first and second mounting flanges 456 , 458 . The mounting flanges are preferably slid into mating flanges 460 , 462 provided on the monitor plate adapter 404 .
Referring to FIGS. 17A and 17B , the wall mount 402 preferably includes a ledge 416 that supports the Allen wrench 418 for storage inside the wall mount. After the longer shaft of the Allen wrench has been slid into a groove formed inside the wall mount 402 , the shorter shaft of the Allen wrench may be rotated so that it sits atop the ledge 416 . The above-described structure provides a storage location for the Allen wrench and increases the chances that the Allen wrench can be easily retrieved when necessary for adjusting the tilt and pan mount 400 .
Referring to FIG. 17A , the monitor plate includes first openings 470 that are adapted to receive the hooks on the expansion plates shown and described above in FIGS. 6A-6B and 7 A- 7 C. The monitor plate 442 includes a plurality of the first openings 470 for providing flexibility for securing the expansion plates to the monitor plate. The monitor plate 442 also include second opening 472 that receive fasteners such as screws for securing the expansion plates to the monitor plate 442 . As the monitor plate adapter 404 tilts and pans, the monitor plate 442 move simultaneously therewith.
Referring to FIGS. 17C and 17D , the tilt and pan mount 400 includes a first tightening knob 474 that may be loosened for enabling the monitor plate adapter 404 to tilt relative to the wall mount 402 . When the desired tilt is achieved, the tightening knob 474 may be tightened for securing the monitor plate adapter 404 in place and preventing further tilting movement of the monitor plate adapter relative to the wall mount 402 .
FIGS. 17E and 17F show the tilt and pan mount 400 including a second tightening knob 476 that may be loosened for enabling the monitor plate adapter 404 to pan relative to the wall mount 402 . When the monitor plate adapter 404 has been panned to a preferred location, the tightening knob 476 may be retightened for preventing further panning movement of the monitor plate adapter 404 relative to the wall mount 402 .
FIGS. 18A and 18B show the Allen wrench 418 stored inside the wall mount 402 . Referring to FIG. 18B , the wall mount 402 includes an elongated groove or channel 420 that receives the long shaft of the Allen wrench 418 . When the long shaft of the Allen wrench 418 has been fully inserted into the groove 420 , the short shaft 422 of the Allen wrench 418 may be rotated so that it sits atop the ledge 416 at a lower end of the wall mount 402 . The structures shown in FIGS. 18A and 18B enables the Allen wrench to be stored with the wall mount 402 at all times and easily retrieved when necessary for adjusting the tilt and pan mount shown in FIGS. 17A-17F .
FIG. 19A shows a cross sectional view of the tilt and pan mount shown in FIG. 17A-17F . The monitor plate adapter 404 is permanently attached to the wall mount 402 by shaft 430 . As noted above, the shaft 430 may not be removed from the assembly so that the monitor plate adapter 404 is permanently attached to the wall mount 402 . Referring to FIGS. 19A and 19B , a rotatable tightening knob 476 is coupled with an upper end of the shaft 430 . When the tightening knob 476 is loosened, the monitor plate adapter 404 is able to articulate relative to the wall mount 402 to provide a panning movement. When the tightening knob 476 is tightened, the monitor plate adapter 404 is secured in place and is no longer able to pan relative to the wall mount 402 .
When the monitor plate 442 is assembled with monitor plate adapter 404 , top flange 448 abuts against a shelf provided at an upper end of the monitor plate adapter. A fastener 452 may then be passed through opening 450 for securing the monitor plate 442 to the monitor plate adapter 404 .
FIG. 20A shows the tilt and pan mount 400 of FIGS. 17A-17F with a top expansion plate 470 and a bottom expansion plate 486 secured to a monitor plate (not shown). In FIG. 20A , the top and bottom expansion plates 470 , 486 are in a non-expanded configuration. In FIG. 20 , the top and bottom expansion plates 470 , 486 are secured to the monitor plate 442 of the tilt and pan mount 400 in an expanded configuration. As is evident, the expanded configuration shown in FIG. 20B is able to secure a larger sized television monitor than is possible when using the non-expanded configuration shown in FIG. 20A . The top and bottom expansion plates 470 , 486 include a plurality of openings that may have fasteners passed therethrough for attaching a television monitor to the top and bottom expansion plates.
FIG. 21 shows a tilt, pan and cantilever mount for a television mounting system, in accordance with further preferred embodiments of the present invention. The tilt, pan an cantilever mount contains many of the features shown and described above in conjunction with the embodiment of FIGS. 17A-17F .
The mount 500 includes a wall mount 502 that is coupled with a monitor plate adapter 504 by an articulating arm 515 . The wall mount 502 includes an articulating link 526 having an internal shaft (not shown) that permanently couples the arm 515 with the wall mount through the articulating link 526 . The mount 500 also includes a tilt and pan link 532 having a shaft (not shown) that permanently couples the tilt and pan link 532 with the articulating arm 515 . The mount 500 also includes another shaft (not shown) that couples the monitor plate adapter 504 with the tilt and pan link 532 to provide a tilting action.
The tilt, pan, and cantilever mount 500 includes three tightening knobs 474 , 475 and 476 . The first tightening knob 474 may be loosened for enabling the monitor adaptor plate 504 to tilt relative to the wall mount 502 . The second tightening knob 475 may be loosened for enabling the articulating arm 515 to articulate relative to the wall mount 502 . The third tightening knob 476 may be loosened for enabling the tilt and pan link 532 to articulate relative to the articulating arm 515 . The shafts that interconnect the components are preferably permanent connections so that the arm 515 may not be decoupled from the articulating link 526 and the tilt and pan link 532 . Similarly, the shaft permanently couples the monitor plate adaptor 504 with the tilt and pan link 532 so that it cannot be disassembled. After the monitor plate adaptor 504 has been panned and tilted to the appropriate orientation, the tightening knobs 474 , 475 and 476 may be tightened for holding the monitor adaptor plate 504 stationary relative to the wall mount 502 .
The articulating arm 515 may have a hollow channel extending from a first end to a second end thereof. Cables such as audio, video and/or power cables may be passed through the channel extending from the first end to the second end of the articulating arm 515 . The channel in the articulating arm 515 enables the cables to be controlled and directed as they extend from the wall mount 502 to a television monitor secured to the television mounting system 500 .
Although the present invention is not limited by any particular theory of operation, it is believed that providing the articulating arm 515 having a length results in the monitor adaptor plate 504 being spaced away from the wall mount 502 . As a result, a television monitor may be secured to the television mounting system and panned or tilted without an edge of the monitor striking the wall to which the wall mount 502 is secured. Without the articulating arm 515 , a television monitor secured to the television mounting system 500 may strike a wall before it is properly tilted and/or panned to a desired orientation. Thus, the articulating arm 515 provides more space between the television monitor and the wall and provides more flexibility for tilting and panning.
FIGS. 22A-22C show a television mounting system including a tilt, pan and articulating mount 600 . The mount 600 includes a monitor plate adaptor 604 that is coupled with a wall mount 602 by a first articulating arm 615 and a second articulating arm 617 . The first articulating arm 615 has a first end 619 and a second end 621 . The second articulating arm 617 has a first end 623 and a second end 625 . The first end 619 of the first articulating arm 615 is coupled with an articulating link 626 secured to the wall mount 602 . The second end 621 of the first articulating arm 615 is coupled to the first end 623 of the second articulating arm 617 by an internal shaft (not shown) that permanently connects the first and second arms together. The second end 625 of the second arm 617 is coupled to a tilt and pan link 632 by an internal shaft (not shown). The monitor plate adaptor 604 is coupled with the tilt and pan link 632 by a tilt support 638 that provides for tilting motion.
The tilt, pan and articulating mount includes permanent linkages formed between the first end 619 of the first articulating arm 615 and the articulating support 626 . A permanent articulating linkage is also formed between the second end 621 of first arm 615 and the first end 623 of second arm 617 . Another permanent articulating linkage is formed between the second end 625 of second arm 617 and the tilt and pan link 632 . Finally, a permanent tilting linkage is formed between the tilt and pan link 632 and the tilt support 638 provided on a back face of the monitor plate adaptor 604 .
The tilt, pan and articulating mount 600 includes a number of tightening knobs that may be loosened for enabling the parts to articulate and/or tilt. The tightening knobs may be tightened when a desired position for the monitor plate adaptor 604 relative to the wall mount 602 has been obtained. Even if the tightening knobs are completely loosened and removed, the permanent linkages ensure that the tilt, pan and articulating mount cannot be dissembled and/or collapse.
FIG. 22B shows some of the permanent linkages that couple the monitor plate adaptor 604 with the wall mount 602 . FIG. 22C shows other permanent linkages that couple the monitor plate adaptor 604 with the wall mount 602 .
Referring to FIG. 23 , in accordance with another preferred embodiment of the present invention, a television mounting system includes a tilt, pan and articulating mount 700 having cable management. As used herein, the terminology cable management means that the routing of the audio, video and/or power cables between a wall and a television monitor may be controlled. Controlling these cables may be desirable to enhance the overall aesthetic appearance of a television system. Control of the cables may also be desirable so as to minimize interference between the power, audio and/or video cables. For example, running a power cable directly next to an audio cable may result in signal interference that diminishes the quality of the audio signal. The same may also apply for video cables. Thus, the cable management system seeks to route the video, audio and/or power cables so as to maximize aesthetic appearance and/or maximize the quality of the audio and video of the television monitor.
The tilt, pan and articulating mount 700 includes a wall mount 702 , a monitor plate adaptor 704 and a monitor plate 742 that are substantially similar in design and function as the embodiment shown and described above in conjunction with FIGS. 17A-17F . The mount 700 includes a cable management system 800 that controls the audio, video and power cables extending from the wall mount 702 to a television monitor secured to the monitor plate 742 . The cable management system 800 also incorporates a structure that enables the monitor adaptor plate 704 to pan and tilt relative to the wall mount 702 .
As shown in FIG. 23 , the mounting system includes a first housing 802 and a second housing 804 that are coupled together by a first articulating link 806 and a second articulating link 808 . The first housing 802 includes a channel 810 extending from a first end to a second end thereof. Audio, video and/or power cables may be passed through the channel from the first end to the second end. Before the cables may be passed through the channel 810 , the end caps 852 , 854 are removed. In addition, a top cap 812 is removed for accessing the channel 810 . The second housing 804 has a similar structure as the first housing including a channel (not shown). A top cap 814 is removed for accessing the channel of the second housing 804 .
The tilt, pan and articulating mount 700 includes a series of permanent linkages that interconnect the components and enable the monitor plate adaptor 704 to articulate and tilt relative to the wall mount 702 . The mount system 700 includes a first shaft 816 that permanently connects a first end of first articulating link 806 with articulating support 826 provided on wall mount 702 . The mount system 700 also includes a second shaft 818 that permanently couples a second end of the first articulating link 806 with the first housing 802 and the second housing 804 . The mount system 700 includes a third shaft 820 that permanently couples the first end of the second articulating link 808 with the first housing 802 and the second housing 804 . The mount system 700 also has a fourth shaft 822 that permanently couples the second end of the second articulating link 808 with a tilt and pan link 832 . Finally, the mount system 700 includes a fifth shaft 824 that permanently couples the tilt and pan link 832 with a tilt linkage 838 provided on a rear surface of the monitor plate adaptor 704 . The mount system 700 also includes tightening knobs 874 that are coupled with the shafts 816 , 818 , 820 , 822 and 824 . The tightening knobs 874 may be loosened for enabling articulating or tilting motion of the monitor plate adapter 704 . The tightening knobs 874 may be tightened when the monitor plate adaptor 704 has been articulated and/or tilted to a desired orientation relative to the wall mount 702 .
Referring to FIG. 23 , similar to the structure disclosed in embodiments above, the shafts 816 , 818 , 820 , 822 and 824 form permanent linkage between the various components of the assembly. The first shaft 816 forms a permanent linkage between the first articulating link 806 and the wall mount 702 that enables the first articulating link 806 to articulate relative to the wall mount 702 . The second shaft 818 forms a permanent linkage between an opposite end of the first articulating link 806 and first ends of the first and second housings 802 , 804 . The second shaft 818 enables the first and second housings 802 and 804 to articulate relative to the first articulating link 806 . The third shaft 820 forms a permanent linkage between the second articulating link 808 and first and second housings 802 , 804 . The third shaft 820 enables the second articulating link 808 to articulate relative to the first and second housings 802 , 804 . The fourth shaft 822 provides a permanent linkage between the second articulating link 808 and the pan and tilt link 832 . The fourth shaft 822 enables the pan and tilt link 832 to articulate relative to the first link 806 . The fifth shaft 824 provides a permanent link between the monitor plate adapter 704 and the pan and tilt 832 . The fifth shaft 824 enables the monitor plate adapter 704 to tilt relative to the pan and tilt link 832 . The assembly 700 also includes tightening knobs 874 . The tightening knobs are preferably coupled with the five shafts 816 , 818 , 820 , 822 and 824 . When the tightening knobs are loosened, the components linked by the shafts are able to move relative to one another. When the tightening knobs 874 are tightened, however, the components linked by the shafts are not free to move relative to one another.
FIGS. 24 and 25 show the assembly 700 of FIG. 23 after the components have been assembled together. The assembly includes wall mount 702 , cable management system 800 , monitor plate adapter 704 and monitor plate 742 .
FIG. 26 shows a rear side of wall mount 702 including a groove 720 formed in the rear surface of the wall mount for securing an Allen wrench 718 .
FIG. 27 shows a cross sectional view of the assembly 700 shown in FIG. 25 . As shown in FIG. 27 , first shaft 816 forms a permanent articulating linkage between wall mount 702 and first articulating linkage 806 . The second shaft 818 forms a permanent linkage between first articulating link 806 and first housing 802 and second housing 804 . Third shaft 820 forms a permanent link between second articulating link 808 and first and second housings 802 , 804 . Fourth shaft 822 provides a permanent articulating linkage between second articulating link 808 and the pan and tilt linkage 832 . Fifth shaft 824 provides a tilting linkage between the monitor plate adapter 704 and the pan and tilt linkage 832 .
Referring to FIG. 28 , the first housing 802 has a channel 810 that extends between first side wall 840 and second side wall 842 . The first and second side walls 840 , 842 include aligned L-shaped slots 844 that are adapted to receive pins 846 . If it is desirable to pass audio/video and or power cables through the channel 810 , the cap 812 is removed to expose channel 810 . The cables are then passed through the well from a first end 848 to a second end 850 thereof. Once the cables have been properly positioned within the well 810 , the pins 846 are positioned in the L-shaped slots and advanced towards the second end 850 of the housing 802 . The cap 812 is then secured atop the housing 802 and over the channel 810 . The underside of the cap 812 includes fingers 852 that are preferably advanced into the L-shaped slots 844 . The insertion of the fingers 852 into the L-shaped slots prevents the pins 846 from retracting from the slots.
Referring to FIG. 23 , when audio, video and/or power cables are passed through the housing 802 , the end caps 852 , 854 must first be removed from the respective first and second ends 848 , 850 of the housing 802 . The end caps 852 , 854 remain removed from the housing 802 when cables extend therethrough.
Referring to FIGS. 27 and 28 , the second housing 804 has a structure similar to the structure found in the first housing 802 . Thus, audio, video and/or power cables may also be passed through a channel extending between first and second ends of the second housing 804 . In certain preferred embodiments, it may be advisable to separate audio and video cables from power cables. Thus, in particular embodiments, the audio and video cables may be passed through the first housing 802 and the power cables may be passed through the second housing 804 . Such a configuration may minimize interference caused by current running through the power cables. In other embodiments, the audio and video cables may be passed through the second housing 804 and the power cable may be passed through the first housing 802 . The particular configuration is not significant so long as the audio and video cables are separated from the power cables. In still other preferred embodiments, it may be advisable to separate the audio and video cables from one another by passing the audio cables through one of the housing and the video cables through the other housing.
FIG. 29 shows the permanent linkage of the first articulating link 806 with the first housing 802 and the second housing 804 . The second shaft 818 provides the permanent, unbreakable linkage. The tightening knob 875 may be loosened for allowing articulating movement of the first articulating link 806 relative to the first and second housing 802 , 804 . The knob 875 may be tightened for preventing further movement of the first articulating link 806 relative to the first and second housings 802 , 804 . The assembly 700 also includes another permanent linkage formed using first shaft 816 that connects first articulating linkage 806 with wall mounts 702 . Tightening knob 874 may be loosened for enabling articulating movement between the wall mount 702 and the first articulating link 808 . The tightening knob 874 may be tightened for preventing further articulating movement between the wall mount 702 and the first articulating link 806 .
FIG. 30 shows an additional permanent linkage interconnecting the monitor plate adapter 704 and the second articulating link 808 . The permanent linkage is providing by the fourth shaft 822 that permanently couples the second articulating link 808 and the tilt and pan link 832 . The fourth shaft 822 provides a permanent, unbreakable articulating linkage between the tilt and pan link 832 and the second articulating link 808 . FIG. 30 also shows a fifth shaft 824 that provides a permanent panning link between the monitor plate adapter 704 and the tilt and pan link 832 . In addition, the assembly includes third shaft 820 that provides a permanent link between the first housing 802 and the second housing (not shown) with the second articulating link 808 . As described above, the tightening knobs may be loosened or tightened depending on whether tilting and/or panning movement is desired.
FIG. 31A shows the assembly shown in FIG. 24 with a top expansion plate 870 and a bottom expansion plate 886 secured to a monitor plate (not shown). FIG. 31B shows top expansion plate 870 and bottom expansion plate 886 secured to monitor plate 742 . In FIG. 31A , the expansion plates 870 , 886 are in a normal or non-expanded configuration. In FIG. 31B , the expansion plates 870 , 886 are in an expanded configuration for securing a larger sized television.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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A television mounting system is disclosed. It includes a wall plate adapted to be secured to a wall and a monitor plate mountable on the wall plate. Expansion plates may be secured at selected locations on the monitor plate to accommodate mounting of various sizes of display screens, such as flat panel televisions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Application No. 60/478,828 filed Jun. 17, 2003 entitled “Method and System for Purchase Receipt Management” which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to associating consumers with their purchases so that consumer transactions can be tied back to a particular consumer. More particularly, the invention relates to the aggregation, management and data mining of consumer purchasing information for the purpose of routing electronic purchase history to consumers and allowing merchant analysis of consumer behavior in order to create consumer profiles to better service consumers and provide more personalized offers.
2. Description of the Related Art
Current receipt management systems do not use aggregated receipt data to facilitate a broad range of post-purchase activities. While certain corporate purchasing cards access Level III purchase data (described further below) for the purposes of automated employee expense control and reimbursement, this purchase data is not utilized to benefit merchants and consumers in the facilitation of a broad range of post-purchase activities. Further, while some merchants offer detailed purchase histories to consumers, these detailed histories are limited to purchases at that particular merchant in order to facilitate merchandise returns.
Currently, consumers' wallets are filled with loyalty and membership club cards, shopper's club cards, frequent shoppers cards, and the like. Consumers must carry and utilize separate merchant membership cards for use with individual merchants. Merchants administer these programs to associate consumers with their respective purchases for the purposes of analysis and relationship management.
SUMMARY OF THE INVENTION
According to an embodiment of the present invention, a process for managing purchase receipt data is described. The process includes enrolling at least one consumer with a receipt manager system by assigning a unique consumer identifier to the at least one consumer and associating at least one consumer payment vehicle with the unique consumer identifier. Next, the process includes enrolling at least one merchant with the receipt manager system and providing the at least one enrolled merchant with instructions for identifying unique consumer identifiers and instructions for forwarding purchase receipt data to the receipt manager system. The purchase receipt data associated with at least one unique consumer identifier is received and aggregated according to the at least one unique consumer identifier.
In another embodiment of the present invention a process for managing purchase receipt data is described. The process includes enrolling at least one consumer with a receipt manager system by assigning a unique consumer identifier to the at least one consumer and associating at least one consumer payment vehicle with the unique consumer identifier. The process further includes enrolling at least one merchant with the receipt manager system and receiving access instructions from the at least one enrolled merchant for accessing consumer purchase receipt data. The consumer purchase receipt data is accessed at the at least one enrolled merchant to identify consumer purchase receipt data that is associated with at least one unique consumer identifier and aggregated according to the at least one unique consumer identifier.
In still a further embodiment of the present invention a process for managing purchase receipt data is described. The process includes enrolling at least one consumer with a receipt manager system by assigning a unique consumer identifier to the at least one consumer and associating at least one consumer payment vehicle with the unique consumer identifier. Next, purchase receipt data is received at a third party service provider, the purchase receipt data including at least the unique consumer identifier and a merchant identifier for each transaction. The consumer purchase receipt data is forwarded to the receipt manager system and aggregated according to the at least one unique consumer identifier.
In yet another embodiment of the present invention a process for managing multiple memberships is described. The process includes enrolling at least one consumer with a membership management system by assigning a unique consumer identifier to the at least one consumer and associating multiple consumer merchant memberships with the unique consumer identifier. The process also includes enrolling merchants associated with the multiple consumer merchant memberships with the membership management system and receiving instructions from the enrolled merchants defining the parameters for each of the multiple consumer merchant memberships. The process further includes
providing instructions for identifying unique consumer identifiers, acquiring consumer merchant membership data associated with at least one unique consumer identifier and aggregating received consumer merchant membership data according to the at least one unique consumer identifier.
In a further embodiment of the present invention a process for aggregating consumer transaction data is described. The process includes establishing a receipt management network including at least one transaction manager, multiple member consumers and multiple member merchants, each of the multiple member consumers being identified via a unique consumer identifier and each of the multiple member consumers having at least one payment vehicle controlled by the at least one transaction manager. The process further includes collecting member consumer purchase information from the at least one transaction manager, the member consumer purchase information including first member consumer purchase information from the multiple member merchants and second member consumer purchase information from non-member merchants based on each of the member consumers' use of their at least one payment vehicle and aggregating the collected first and second member consumer purchase information for review by at least one of the multiple member merchants.
BRIEF DESCRIPTION OF THE FIGURES
In the Figures:
FIG. 1 shows a schematic system and method for an exemplary receipt management network according to an embodiment of the present invention;
FIG. 2 shows a schematic system and method for an exemplary receipt management network according to an embodiment of the present invention;
FIG. 3 shows a schematic system and method for an exemplary data aggregation network according to an embodiment of the present invention; and
FIG. 4 shows a schematic system and method for an exemplary membership consolidation network according to an embodiment of the present invention.
DOCUMENTS FOR INCORPORATION BY REFERENCE
The teachings disclosed in the following documents are hereby incorporated by reference herein in their entireties:
U.S. Pat. No. 5,056,019,
U.S. Pat. No. 6,292,789, and
U.S. patent application Ser. No. 10/411,192 filed Apr. 11, 2003 entitled “METHOD AND SYSTEM FOR A MULTI-PURPOSE TRANSACTIONAL PLATFORM.”
DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , in an embodiment of the present invention, a receipt management network (hereafter “RMN”) 10 includes at least one consumer 12 , at least one merchant 14 and a receipt manager 16 . A preferred embodiment includes multiple consumers and multiple merchants. As used herein, consumers may be individuals, businesses or any other purchasing entity and need not be affiliated with any of the other network entities unless specifically stated herein as being so. Initially, the consumer 12 enrolls in the RMN through various available processes, including, but not limited to, on-line registration, mail-in registration and telephonic registration S 1 . Consumer registration is acknowledged and completed through assignment of a unique consumer identifier (hereafter “CID”) S 2 . Similarly, the merchant 14 enrolls in the RMN as well S 3 , with enrollment completed via acknowledgment by the receipt manager and assignment of a merchant identifier (hereafter “MID”) S 4 . Additionally, the receipt manager may provide the merchant with CID identification and forwarding software for installation on the merchant's purchase processing system. This software facilitates the identification of member consumers through, for example, a membership listing, e.g., look-up table, and includes routing instructions for forwarding identified member consumer receipt information to the receipt manager. Alternatively, using established network communication lines, the receipt manager may identify associated CIDs within a merchant database(s) and retrieve receipt information using pre-established interfacing routines.
Once enrollment is complete, upon a member consumer completing a purchase from a member merchant S 5 , the receipt manager receives receipt information from the merchant S 6 . The consumer may also receive a receipt at the time of purchase, i.e., electronic receipt for Internet purchase or hardcopy receipt for brick and mortar purchase or telephone purchase. The receipt information may include itemized receipt data. The itemized data can be sent to the receipt manager directly at the time of purchase from the point of sale (hereafter “POS”) or it can be sent via a periodic batched transfer. Preferably, the receipt capture and forwarding processes are electronic, but portions of the process may be manual if necessary. For example, in an alternative embodiment, a member consumer may input receipt information directly with the receipt manager for non-member merchants, e.g., by scanning in a copy of the receipt or manually entering details through a graphical user interface on the receipt manager's website S 7 . The itemized receipts are associated with the consumer according to the CID collected at the POS. The receipt manager receives and stores the itemized receipts according to the CID. The RMN facilitates receipt aggregation and the mining and formatting of data from aggregated receipts in order to reduce certain consumer service costs incurred by all aforementioned parties and increase revenue through targeted sales based on the mined data and enhanced consumer service. The consumers participate in the receipt network in order to receive their purchase receipt electronically so that it can be used conveniently for several post purchase activities including returns, (tax) records, rebates, warranties, repeat purchases and reminders via the receipt management application described herein.
Aggregating a group of merchants that wish to participate and establishing connectivity from each to the receipt manager for the purposes of purchase data routing will establish a network of member merchants. These connections may leverage existing payment and data network infrastructure (e.g. Internet, MasterCard network) in whole or in part. The network may utilize a single standard technology or a plurality of technologies to route purchase data to the receipt manager.
Referring to FIG. 2 , in an alternative embodiment, the RMN 10 further includes a third party participant 18 . In this alternative embodiment, instead of receiving receipt data from the merchant(s) 14 , the receipt manager 16 receives receipt data, or at least part of the receipt data, from a third party participant 18 , such as a credit authorization entity (e.g., MasterCard, Visa, etc.), a financial institution, an electronic fund transfer (EFT) entity or the like S 11 . By way of example, whenever a member consumer utilizes a credit payment vehicle, e.g., credit card, to make a purchase from a merchant, the payment authority receives a payment authorization request from a merchant S 8 . According to this alternative embodiment, once the payment authority authorizes the request, the payment authority forwards authorization to the merchant S 9 and sends extracted authorization data to the receipt manager S 11 . In this embodiment, the non-member merchant may provide the consumer with a receipt S 10 since the non-member merchant is not aware of the consumer's membership in the RMN. Alternatively, the merchant 14 is a member of the RMN 10 , but elects to have a third party participant 18 handle the CID identification and receipt forwarding process. As stated above, these embodiments which utilize a third party participant may leverage existing payment and data network infrastructure (e.g. Internet, MasterCard network) in whole or in part.
The purpose of the CID is to associate a particular transaction with a specific consumer so that itemized purchase (e.g., receipt) data is routed and assigned correctly to the consumer purchaser. In a particular embodiment, the CID is assigned to the consumer through a particular payment method, for example, a particular payment vehicle, e.g., credit, debit, stored value, home equity account or the like, through the receipt manager. The payment vehicle may or may not be issued by the receipt manager. For example, referring to S 1 of FIGS. 1 and 2 , in a particular embodiment, when a consumer enrolls in the RMN, a consumer could (1) request that an existing credit or debit account number be utilized as a CID; (2) request a unique CID in association with an existing credit or debit account; (3) request a separate unique CD for each of the consumer's existing credit or debit accounts; (4) request a single OD that is linked to each of the consumer's existing credit or debit accounts; (5) request one or more new credit or debit accounts which may be linked with one or more CIDs. In this particular embodiment, whenever the consumer utilizes one of the linked credit or debit accounts to make a purchase, the account number is matched against a database listing of enrolled account numbers with corresponding CIDs. For account numbers that are enrolled, the corresponding CD is assigned to the transaction and the CID and the receipt are forwarded (electronically or manually) to the receipt manager according to the CID.
Alternatively, the consumer may be assigned a CID through the receipt manager independent of any particular payment vehicle. This OD may be carried on, for example, a card, which may be read, e.g., scanned at the POS or verbally associated with a transaction by the consumer at the POS or manually entered by the consumer when making an on-line purchase. Consumers present this card or number at the POS in order to be identified as program participants and ensure that all consumer purchase receipts, regardless of payment vehicle selected at POS, e.g. cash, check, credit card, debit card, are associated with the consumer and transmitted to the receipt manager.
Once the receipt manager receives the itemized receipts, the receipt manager is able to organize, store and present the information from the itemized receipts for review by the consumer. Itemized receipts contain detailed information including merchant information (e.g., merchant name/brand), item or service description (e.g., Hewlett Packard HP 750 Ink-jet Printer) and price information ($129.00+10% tax=$141.90), payment vehicle information (Citibank MasterCard with last 4 account number digits), time of purchase information (Apr. 26, 2003, 6:00 pm EST), and the like. Detailed Information may include, but is not limited to, Level III data fields as they are defined in the credit card industry. Level III data includes line item details, e.g., item by item descriptions of each component of the purchase, and other data such as, but not limited to quantities, product code, product description, brand identification, stock keeping unit (SKU), ship-to-zip, freight amount and duty amount, order/ticket number, unit of measure, extended item amount, discount indicator, discount amount, net/gross indicator, tax rate applied, tax type applied, debit or credit indicator, and alternate tax identifier. The receipt information may be viewed on-line by the consumer, in a consumer selected format, e.g., according to merchant, according to payment vehicle, according to category of goods or services, according to price, according to purchase date and the like. This receipt aggregation and presentation allows consumers to view all receipts on a single website. Alternatively, the receipt manager can provide formatted information to individual merchants, for posting on merchant websites for review by individual merchant consumers. The data can be stored in the receipt manager's databases and/or it can be downloaded at consumer request to a personal computer and/or PDA device. The data can be incorporated into personal financial management software for budgeting, taxes or other purposes.
In addition to the aggregation and formatting services provided by the receipt manager, other value-added tools for receipt management can be provided. These value-add tools include prompts for using data in the aggregated consumer receipts for record-keeping purposes, for budgeting purposes, for tax record purposes. More particularly, receipt data may be used to continually and automatically update consumer-created shopping lists and/or personal registry, e.g., wish, lists. The receipt management system described herein may be used as a personal accountant for each individual consumer.
Additionally or alternatively, the receipt manager may merge the receipt data with consumer payment vehicle spending data. For example, in those cases where the receipt manager also issues the payment vehicle, the receipt manager may use the receipt data in conjunction with payment vehicle spend data for consumer targeting and consumer relationship management (CRM) purposes, and also for economic forecasting, both industry forecasting and/or forecasting relating to a specific merchant. Consumer receipt data may be used by the receipt manager and/or other consumer service entities in order to better ascertain and understand consumer spending habits and improve marketing and targeting techniques, e.g., create consumer profiles to better service consumers and provide more personalized offers.
Referring to FIG. 3 , a specific exemplary embodiment is shown wherein the data from the RMN is used in conjunction with other transaction data, i.e., consumer payment vehicle spending data, in order to provide useful consumer transaction data to member RMN merchants. In FIG. 3 , the transaction manager 33 receives consumer transaction data 34 in the form of consumer receipt data 35 and other consumer transaction data 36 from the RMN member merchant 14 a , S 34 . In this embodiment, the transaction manager 33 functions as the receipt manager as described above and is, for example, a financial institution capable of offering financial payment services to consumers such as credit and debit accounts. The transaction manager 33 has established payment vehicle relationships with both RMN member consumers 12 a and 12 b (S 30 ) and non-RMN member consumers 12 c and 12 d (S 32 ). The transaction manager 33 also receives other consumer purchase data 36 from non-RMN member merchants 14 b for both RMN member consumers 12 a and 12 b and non-RMN member consumers 12 c and 12 d . By way of example, other transaction data might include credit card purchase data for a RMN member consumer for transactions with non-RMN member merchants. Utilizing all of the consumer transaction data 34 , the transaction manager 33 aggregates the transaction data in order to ascertain and analyze the purchasing habits of consumers through their use of the payment vehicles, i.e., payment accounts for the consumers that are managed by the transaction manager 33 .
By way of particular example, assuming RMN member merchant 14 a is Best Buy, the transaction manager 33 receives consumer receipt data 35 for purchases at Best Buy buy RMN member consumers 12 b , 12 b (S 34 ). This data is detailed, Level III data, such as purchase type data, e.g., DVDs. The transaction manager 33 is also collecting other RMN member consumer purchase data for purchases made with a transaction manager sponsored payment vehicle outside of the RMN, e.g., from non-RMN member merchants 14 b (S 36 ). So for example, this data might show that while the RMN member consumers 12 b , 12 b are loyally purchasing DVDs from Best Buy, the same RMN member consumers 12 b , 12 b are purchasing electronics from other stores in the electronics industry. Further still, the transaction manager 33 aggregates all of the collected consumer transaction data 34 and provides high level reports to the RMN member merchants 14 a (S 38 ).
In a further embodiment of the present invention, the receipt manager facilitates the granting of rebates for eligible merchants and consumers. In this embodiment, an eligible merchant, i.e., a merchant or manufacturer signed up with the receipt manager's receipt management system, notifies the receipt manager if a consumer uses applicable merchant or manufacturer rebates during a purchase. This notification may be performed in real-time or through batch processing. The rebate could be associated with the consumer's CID. The receipt manager, at the request of the merchant, fulfills that rebate electronically, e.g., on the day of the sale to the consumer's payment vehicle of choice or by default to the payment vehicle used to make the initial purchase or, in certain instances, to a financial account of the consumer, e.g., checking, savings, investment or the like. The rebate could be fulfilled instantly or not, depending on the capabilities and business interests of the rebate issuing entity (manufacturer or retailer). This electronic rebate process eliminates the need for the paper-intensive rebate system that requires the consumer to make a copy of the payment receipt, send in the proof-of-purchase, which is typically in the form of a UPC symbol and then wait several weeks for the manufacturer to process that rebate and then remit payment. This system will also enable fraud controls for the rebate process that will prevent fraudulent rebate redemption and will reverse rebate payments for items that are returned after a rebate is paid.
In a particular example, a member manufacturer (e.g., Sony) who participates in the automatic rebate service provided by the receipt manager offers a rebate on a specific good (e.g., Digital Video Disc (DVD) player). A member consumer shopping at a member merchant store, brick and mortar or on-line, e.g., Best Buy, peruses the available DVD players. The member consumer finds that Sony offers an automatic rebate through the receipt management network and chooses the Sony DVD player over other potential choices from other manufacturers.
In another embodiment of the present invention, membership in the receipt management network facilitates product registration for warranties and other purposes. In addition, the receipt management application can serve as a consolidated source for product information (e.g. manuals, directions) related to past purchases. This information may be stored with the receipt manager or may reside with the respective merchants. In such case, links to the merchant's web site can lead consumers to desired information. The receipt management application can also present intelligent offers based on purchase history that are tailored for a specific consumer with a particular purchase history.
In a further embodiment of the present invention, membership in the receipt management network facilitates more efficient merchandise returns by consumers and protects both merchants and consumers from fraud. Member consumers do not have to worry about losing receipts, and possibly not being able to return merchandise, since the receipts are stored electronically within the receipt management network and accessible to the merchants. Consumers can opt to simply print receipts from their personal computer, or they can rely on member merchants to electronically retrieve their receipt data in-store (for merchants that opt to do so). This receipt storage allows merchants to check the identity of the consumer with the receipt prior to returning value to the consumer. Further still, the merchant may credit value to the payment vehicle that was used in the transaction, thus protecting the consumer as well as the merchant from fraud. Because the receipt management network also keeps the payment details of the transaction, the network protects merchants from those member consumers who might try (accidentally or purposefully) to return an item to a different merchant store, i.e., within the merchant's integrated back-end system connecting all stores, for store credit that is in excess of what they originally paid.
Referring to FIG. 4 , in a further embodiment of the present invention, similar to FIG. 1 , a membership consolidation network (“MCN”) 12 includes at least one consumer 12 , at least one merchant 14 and an administrative membership entity 30 . A preferred embodiment includes multiple consumers and multiple merchants. Consumers may be individuals, businesses or any other purchasing entity. Initially, the consumer 12 enrolls in the MCN through various available processes, including, but not limited to, on-line registration, mail-in registration and telephonic registration S 20 . Consumer registration is acknowledged and completed through assignment of at least one unique consumer identifier (hereafter “CID”) S 21 . Similarly, the merchant 14 enrolls in the MCN as well S 22 , with enrollment completed via acknowledgment by the administrative membership entity and assignment of a merchant ID (hereafter “MID”) S 23 . During the merchant enrollment step S 22 , the merchant may provide varying levels of detailed merchant loyalty program information to the administrative entity which may be stored in a loyalty program database 32 according to MID.
The CIDs may reside on a debit or credit card, e.g., may be same as a debit or credit card number, or may be a different identifier that is held by participating merchants and/or the receipt manager and is linked with a consumer's debit or credit account or finally, the CID may be issued as a stand alone unique identifier that is linked to consumer transactions at the POS by the consumer. In this further embodiment of the present invention, the CID is used to identify a consumer to a membership consolidation network (hereafter “MCN”), which is also accessible by participating merchants as well as the MCN administrative management entity. The MCN may consist of the entire RMN or a subset of individual merchants or alternatively, a set of merchants not enrolled in the RMN. Alternatively or in addition to the consumer's membership in the RMN, the OD may also be associated with consumer's membership information for other merchant programs such as loyalty, shoppers clubs and other memberships such as video store, coffee shop and music store memberships. Consumer data that is associated with the consumer's CID(s) may be stored in a consumer CID database 31 . As such, the OD facilitates the consolidation of a consumer's memberships, thus reducing the number of cards and/or ID numbers that must be carried and utilized by a consumer in order to participate in membership programs offered by various merchants.
Each of the consumer's merchant memberships is accessible through the consumer's CID, which acts as a proxy of all other membership numbers and information. Participating merchants can connect to the MCN and agree to accept the OD at the POS each time the consumer uses the OD in association with a purchase from the merchant. In a particular implementation of the further embodiment, a first database at either the merchant or the MCN administrative management entity confirms the CID and the identity of a given consumer and a second database at either the merchant or the MCN administrative management entity associates that OD with the merchant's account number for that consumer's membership with the merchant, in order to facilitate the transaction. Alternatively, the number of databases may vary. The same database may provide all information or the information may be spread over more than two databases. One skilled in the art recognizes the varying system architectures that may be used to facilitate the information storage and transfer described in the embodiments set forth herein.
The information databases may be populated with data in a number of ways. First, participating merchants may provide consumer membership information to the MCN administrative management entity for association with participating consumer CIDs and storage within the appropriate databases accessible through the MCN. This participation information may be provided in a real-time or through a batch process. In a particular embodiment, a participating merchant may associate a new consumer's merchant membership to the consumer's existing CID at the time of assignment of the membership at the POS. Alternatively, the consumer may associate the consumer's various memberships through the MCN administrative management entity, e.g., through a designated website, or the consumer may request a search for all of the consumer's merchant memberships and association with the consumer's CID.
By way of particular example, a consumer attempts to purchase his morning coffee and muffin at his local Starbuck's Coffee shop. The consumer is carrying his OD, which is his credit card number. The consumer has a stored value account with Starbuck's and has a balance of $25.00 in his account. The consumer's account at Starbuck's has been associated with the consumer's CID. When the Starbuck's clerk reads the CID at the POS, the CID, along with Starbuck's merchant ID information from the merchant-side software, is sent over the MCN for (a) verification of the consumer through the CID and (b) recording of the purchase amount in that consumer's Starbucks loyalty account. In parallel, the stored value account is debited for purchase amount via the normal process for Starbucks transactions (not impacted by (a) and (b)).
Although the embodiments presented herein have been described separately in order to highlight different functionalities, one skilled in the art recognizes that the RMN and MCN can be the same network that incorporates, inter alia, the receipt management and membership consolidation functionalities described herein. For example, utilizing the CIDs, the consolidation of the functionalities into a single network facilitates, in addition to receipt management, the tracking of loyalty applications and updating of such applications and rewards based on information mined from a consumer's receipts. Both consumers and merchants are able to access the network to view, in addition to receipt data, the status of different loyalty accounts.
The embodiments presented herein are merely exemplary. One skilled in the art recognized the numerous variations of the presented embodiments that fall within the scope of the invention. Further, one skilled in the art recognizes the supporting frameworks and architecture that are usable with the embodiments presented herein and are presumed known at the time of the filing of this application.
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A system and method for associating consumers with their purchases so that consumer transactions can be tied back to a particular consumer is described. More particularly, a central transaction entity as part of a larger network collects, aggregates, manages and mines consumer transaction data from at least consumer and merchant members of the network for the purpose of routing electronic purchase history to consumers and allowing merchant analysis of consumer behavior in order to create consumer profiles to better service consumers and provide more personalized offers.
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BACKGROUND OF THE INVENTION
The invention relates generally to vehicle modifications and more particularly to a top conversion and boat combination assembly for a van, trailer or similar vehicle. Vehicles intended for recreational purposes are conventionally equipped with a trailer hitch and trailer upon which a boat is mounted and towed to a lake, bay or the ocean and then launched into the water. Such a configuration is both difficult to drive and potentially dangerous, particularly at speeds of 55 mph or greater. Boat trailers are usually flimsy structures which bounce at driving speeds. Accidental boat loss during travel is not uncommon. Once at the waterfront, the vacationer usually must wait an hour or two before being able to use the local boat ramp to launch his boat. Thereafter the vehicle and trailer must be parked elsewhere before the boat may be used. Before and after the trip, the vehicle and trailer must be attached together and separated, respectively. The nuisance of dealing with the trailer ball and hitch, brake and turn signal light connections, safety chain hookup and expense of fender mounted rear view mirrors makes the whole experience a less than desirable one.
Proposals have been advanced to mount a small boat directly on top of a vehicle by means of a supporting rack structure on the vehicle roof to thus dispense with the need for a trailer. However, as in the case of trailers, such structures tend to be rather flimsy and thus unsatisfactory. Additionally, the aerodynamics of such a combination, particularly at high speed road travel, are undesirable.
The prior, patented art includes several teachings of a vehicle-boat combination, none of which appear to have been met with acceptance in the market place. U.S. Pat. No. 2,598,458 discloses a trailer with a boat mounted on the top thereof, including a rail along the trailer top centerline and a grooved roller on the boat bow to assist placement of the boat on and removal from the trailer roof. However, the combination as taught appears incapable of single handed operation. Other teachings of vehicle roof and boat combinations are found in U.S. Pat. Nos. 2,310,431 and 3,324,487. Prior art teachings of the boat serving as the vehicle roof when the boat is not used are found in U.S. Pat. Nos. 1,455,994; 3,473,839; 3,955,731; 3,933,112; and 4,036,520.
What is not taught by the prior art is a vehicle top and boat combination as herein disclosed and claimed, including a groove formed in the vehicle top and a cooperating handle and roller assembly on the bow of the boat, the roller assembly and groove arranged so that the boat may be removed from and replaced on the vehicle top by one person. The boat is formed to fit symmetrically over the top to form a dead air, insulating space therebetween and both boat and top are designed for maximum aerodynamic efficiency.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the invention to provide a vehicle top and boat combination, such as a van top conversion with a mating, symmetrical boat thereon, which may be easily removed from and replaced on the top by a single person.
It is another object of the invention to provide a vehicle top and boat combination including a groove formed along the centerline of the top and a handle with a pair of rollers adapted to ride in the vehicle top groove to facilitate boat loading and removal.
It is a further object of the invention to provide a vehicle top and boat combination which may be locked easily and securely to the top for road travel and security when not attended.
Yet another object of the invention is to provide a vehicle top and boat combination which is readily adapted for installation on any conventional van type of vehicle.
Yet a further object of the invention is to provide a vehicle top and boat combination which are symmetrically formed to provide a dead air, insulating space therebetween when in assembly, the external configuration of the boat assuring maximum aerodynamic efficiency.
It is still another object of the invention to provide a vehicle top and boat combination, the boat being formed with elongate tubular stiffeners therein for added strength and flotation as well as to facilitate launching from a shoreline into the water by merely sliding the boat along to the water, the boat further having a pair or snap-fit removable seats which are each provided with additional flotation.
It is still a further object of the invention to provide a vehicle top and boat combination wherein the boat is provided with a pair of transom mounted handles in addition to a bow mounted handle to thereby provide a convenient 3 point lift attachment for conventionally hoisting the boat into the water.
Still another object of the invention is to provide a vehicle top and boat combination of enhanced versatility, wherein the boat may be partially removed from the top and pole supported between the ground and the boat transom, thereby providing a convenient canopy for the vehicle when camping.
Generally, the vehicle top and boat combination disclosed herein includes a van top convension in the form of a "bubble top" and a symmetrical boat fitted over the top. In a preferred embodiment, the combination is marketed as a van top conversion kit called a "Bubble Boat". The roof of a conventional van is entirely removed or a portion may be left to serve as a storage shelf. The top "Bubble Top" is then installed onto the van. The top includes a groove or depression formed exteriorally along the centerline thereof. The boat has a swivel handle and roller assembly mounted on the bow thereof to facilitate loading and unloading of the boat. The top has a peripheral skirt formed about the base thereof so that, in assembly, the boat and top form a smooth, uninterrupted, aerodynamically stable structure. The boat gunnels are provided with oarlock mounts which further serve to latch the boat to the top. The swivel handle is also used to lock the boat to the van. The boat is of flat bottom, step chined configuration, made of molded fiberglass with a series of tubular, longitudinal stiffeners therein for increased strength and flotation. The boat may have a pair of transom mounted handles to assist loading and unloading of the boat from the van. A pair of flush mounted rollers are located on the peripheral skirt of the top, one on either side thereof, to further aid boat loading and unloading. A pair of snap-fit, removable seats with additional flotation are provided for the boat. A pair of poles may be used to support the boat from the rear of the top so that the boat becomes a convenient canopy.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects of the invention will become readily apparent by reference to the following specification and drawings in which:
FIG. 1 is a perspective view of a preferred embodiment of the invention with the boat removed to reveal the van conversion top;
FIG. 2 is a front elevation view of the invention as shown in FIG. 1 with the boat elevated as indicated in phantom lines to reveal the van top therebeneath;
FIG. 3 is a perspective view of the boat and snap-fit seats for the boat;
FIG. 4 is a partial side elevation view of the invention, partly in section, illustrating loading and unloading of the boat;
FIG. 5 is an elevation view of a latch pin used to secure parts of the boat to the top;
FIG. 6 is a detail view of one flush mounted roller located along a side of the peripheral skirt of the top;
FIG. 7 is a view similar to FIG. 4 further illustrating loading and unloading of the boat from the top;
FIG. 8 is a front, elevation view of the swivel handle and roller assembly mounted on the bow of the boat; and
FIG. 9 is a detail, section view through a portion of the boat disclosing one of the tubular stiffeners molded therewithin.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings by reference character, and in particular to FIGS. 1 and 2 thereof, a conventional van 10 is illustrated, equipped with the van top conversion and boat combination of this invention, including a bubble top 12 and a boat 14, shown removed from the van 10 in FIG. 1 to more clearly reveal top 12. One or more windows 16 may be provided in top 12 as desired. As can be seen in FIGS. 2 and 4, the exterior of top 12 and the interior of boat 14 are symmetrically formed to provide a dead air space 18 (FIG. 4) therebetween. When boat 14 is in place on top 12, dead air space 18 provides a significant amount of insulation for van 10 as well as some soundproofing.
Bubble top 12 may be readily installed on a conventional van 10 either professionally or by a "do-it-yourselfer" with some knowledge of tools. In the preferred embodiment, top 12 is molded of fiberglass with a heavy, reinforced fiberglass peripheral skirt or flange 20 thereabout (FIG. 6). A peripheral shelf 22 is molded into top 12, concentrically inwardly of skirt 20 and slightly thereabove. Shelf 22 is dimensioned so that boat 14 and top 12 present a smooth uninterrupted profile in assembly, as shown in FIG. 4.
Modification of van 10 to receive bubble top 12 and attachment of top 12 to the van are accomplished by a rather conventional procedure. First, the existing roof of van 10 is cut out to an appropriate sized opening. If desired, a portion of the van roof may be left (not shown) to serve as a storage shelf for parts of the boat or other equipment. An intermediate gasket 24 of desired thickness (FIGS. 4 and 7) is coated on both sides with a silicone sealer or the like to assure watertight integrity of top 12 with van 10. Gasket 24 is placed about the opening whereafter the top 12 is placed over the opening with flange 20 resting on gasket 24. Flange 20 is secured firmly by a number of pop rivets 26 evenly spaced about flange 20.
A significant feature of top 12 is the provision of a groove or depression 28 running the full length of top 12, along the centerline thereof. Groove 28 provides a guide track for the rollers 30 of a swivel handle and roller assembly 32 mounted on the bow of boat 14 during boat loading and unloading. Further assistance for the operation is provided by a pair of flush mounted rollers 34 mounted within shelf 22 (FIG. 6) towards the rear of top 12 and van 10 (FIG. 4), one roller on each lateral side of top 12. A pair of handles 36 (one of which is shown in FIG. 4) provide convenient hand grips for boat loading and unloading.
In addition to rollers 30, swivel handle and roller assembly 32 includes a handle 38, an axle 40 with bushings 42 which are mounted within a notch formed in the bow of boat 14 (FIG. 7), a roller axle 44 for rollers 30 and a wheel strut and strut support 46 welded to the base of handle 38, all as shown in FIG. 8. As illustrated by phantom lines in FIG. 7, handle and roller assembly is locked in position for boat loading and unloading by a convenient snap pin 48 (FIG. 5) inserted through a bifurcated fitting 50 mounted on the bow of boat 14. Snap pin 48 is rather conventional in structure and includes ball snaps 52 which are retracted by depression of a push button 54.
As shown in full lines in FIG. 7, the bow of the boat may be securely locked to van 10 and top 12. With pin 48 removed, handle and roller assembly 32 is swiveled forwardly and downwardly so that handle 38 is located between the ears of a second bifurcated fitting 56 located on van 10. A padlock 58 engages handle 38 with fitting 56. Alternatively, the snap pin 48 may be used in place of padlock 48 if theft is not a worry. Similarly, padlock 58 may be used in place of pin 48 to locate handle and roller assembly 32 for loading and unloading of boat 14, as shown in phantom lines in FIGS. 4 and 7. If desired, pin 48 may be tethered to the bow of boat 14 by a short length of cord or brass link chain so that pin 48 will not be lost.
Further security of boat 14 on top 12 is assured by inserting additional snap pins 48 through oarlock mounts 60, on either side of boat rails 62 (FIGS. 3 and 4), into mating bores 64 formed in shelf 22 of top 12. Balls 52 of pin 48 engage a catch plate 66 molded within shelf 22 (FIG. 4).
Fittings 50 and 56, pins 48, handle 36, oarlock mounts 60 and appropriate components of handle and roller assembly 32 may be fabricated from stainless steel or other material having suitable strength and rust resistant properties.
As hereinbefore set forth, boat loading and unloading may be accomplished easily by one person and without need of any tools. First, pins 48 engaging oarlock mounts 60 with shelf 22 are removed by depressing button 54 of each pin 48 and lifting pin 48 out of its bore 64. Next, padlock 58 (or pin 48) is disengaged from handle 38 and fitting 56. Handle 38 is rotated upwardly and pin 48 (or padlock 58) is inserted through fitting 50 on boat 14 and handle 38. Then, handles 36 (FIG. 4) on the transom of boat 14 are grasped and pulled. Boat 14 moves easily upwardly and rearwardly as shown in phantom lines in FIG. 7. Additionally, the forward portion of groove 28 is gradually deepened towards its forward terminus, as shown at 68 in FIG. 7, not only to ease the boat unloading operation but also to provide room for rollers 30 when the boat is fully loaded, also as shown in FIG. 7. Also, flush mounted rollers 34 assist loading and unloading by providing a virtually friction free mounting of boat rails 62 on shelf 22 of top 12.
Boat 14 is pulled rearwardly with rollers 30 riding in groove 28. As the bow of boat 14 approaches the rear of top 12, the transom of the boat may be lowered to the ground and the boat stood upright as shown in FIG. 1. Boat 14 is then easily lowered to the ground. Reloading of the boat is accomplished by merely reversing the steps just outlined.
A preferred embodiment of the construction of boat 14 will now be discussed in detail. It is made of molded fiberglass employing techniques conventionally used with a few significant improvements. Of course, boat 14 is molded into the same general shape as its counterpart top 12. The boat design is a hard chine, flat bottom type with stepped gunnels or sides each being three in number as indicated at 70. The bow of the boat is spoon shaped not only to enhance stability when in water but also to create a streamlined laminar air flow thereby during road travel.
As is shown in FIG. 2, the bottom of the boat includes five, one-inch diameter aluminum tubing stiffeners 72 molded into the fiberglass; center stiffener 72a forms a keel for the boat. In the preferred embodiment, tubes 72 provide 1.6 cubic feet of trapped air space, thus increasing fresh water buoyancy by about 100 lbs. These five stiffeners 72 also facilitate sliding the boat over the ground and into the water after unloading from top 12.
A pair of removable seats 74 are provided, the ends of which are merely snap fit into molded in seat slots 76 having bights 78 to receive seats 74. Each seat 74 includes a block of flotation material 80 secured therebeneath for added flotation.
In a preferred embodiment, boat 14 is about 11 feet long, 5 feet wide and 1.5 feet deep. The boat alone weights but 130 lbs. and thus is easily handled by one person. The transom is sloped slightly (FIG. 4) for improved road travel aerodynamics. Color may be molded into both boat 14 and top 12 according to customer wishes. Both boat 14 and top 12 may be made in varying depths and heights, respectively, to suit customer preference.
Bow handle 38 and transom handles 36 also provide a convenient 3 point lift attachment for a three wire lift sling (not shown) when it is feasible to hoist the boat into the water. The boat may be used as a van canopy for camping and the like by merely partially unloading it from the van top and supporting the transom by simple poles equipped with snap hooks (not shown) engaging handles 36 in tripod fashion. Of course, handle 38 may be used to tie boat 14 to a dock piling or cleat (not shown).
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A van top conversion or "bubble" top in combination with a boat symmetrically fitted thereover. A handle has a roller assembly on the bow of the boat cooperating with a groove formed exteriorally along the centerline of the top conversion to permit single handed removal of the boat from the top and replacement thereon after use. Oarlock mountings on the boat gunnels and the bow handle have complementary fittings on the top to secure the boat for road travel. The boat is formed with tubular stiffeners for structural integrity and flotation and is equipped with a pair of snap fit, removal seats having additional flotation.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to displacement conversion mechanisms and, in particular, to the conversion of rotary to translational displacement and to actuators employing such mechanisms.
BACKGROUND OF THE INVENTION
[0002] Actuators for producing a mechanical displacement of a member to be driven are employed throughout industry in a wide variety of applications. These include machinery control mechanisms, including valves and linkages, robotics, prosthetics, camera optics, pumps, brakes and power tools to name but a few. The displacement required may be rotary, linear or other translational and of short or long stroke. It may be unidirectional, with a separate return mechanism such as a spring or bidirectional, including reciprocation. The choice of actuator for a particular application often depends on the environment in which it is to be used.
[0003] Many forms of actuator for producing linear or other translational displacement of a driven object are known in the prior art. These include straightforward pneumatic and hydraulic piston arrangements and more recently developed devices known as “air muscles” in which inflation of a bladder causes contraction of an outer metal sheath in a manner similar to living muscle contraction. Other forms of linear actuator are electromagnetic, such as the solenoid and the voice coil motor. Such devices have limited extension capabilities.
[0004] Electric motors, such as stepper or servo motors, are also convenient drivers for actuator devices but to produce linear displacements their rotary output must be transformed into a linear motion by a suitable conversion mechanism. Many such mechanisms have been employed for this purpose such as the rack and pinion mechanism and the lead screw. In the latter case, a short threaded nut is translated along a long threaded shaft rotated by the motor and is coupled to a member to be driven, such as a print carriage. By appropriate choice of thread pitch or use of additional gearing, the mechanical advantage of this type of mechanism can be increased to produce relatively large extensions for small rotations.
[0005] Cam shafts and followers, biased by a return spring, are also widely used, especially in conventional engines, for producing reciprocating linear motion and similar cam follower and spring arrangements are also used in power tools to produce a reciprocating action from a conventional electric motor drive shaft.
[0006] There is still scope however for a simple rotary to translational motion conversion mechanism, capable of producing large extensions for a limited angle of rotation and robust enough to be tolerant of hostile environments. The present invention offers such a mechanism.
[0007] Also known in the prior art are adjustable shims or spacer arrangements for producing a desired static linear displacement by relative rotation of complementarily shaped discoidal wedges or cams. Such arrangements are described in U.S. Pat. No. 4,433,879 (J. C. Morris) for an “Adjustable Extension-Cam Shim” and in GB published patent application 2331568 (A. Szmidla) for “Wedges and arrangements thereof”.
DISCLOSURE OF THE INVENTION
[0008] Accordingly, the invention provides a rotational to linear displacement conversion mechanism comprising: an assembly including a plurality of driver discoidal elements and a plurality of driven discoidal elements mounted alternately on a common central axis to form an interleaved stack, each discoidal element having a ramped surface, the ramped surfaces of adjacent elements being complementarily shaped and opposed so that, when in contact and completely interengaged, they form a stack of minimum length; coupling means for coupling the driver discoidal elements for rotation together about the axis by an externally applied force while permitting them to translate along the axis; said driven elements being mounted in such a way as to permit translation along the common axis while preventing rotation of the driven elements about the common axis, whereby a rotational displacement of the driver elements by such an externally applied force causes the elements to separate by camming action of their interengaged ramp surfaces so as to produce an extension of the stack corresponding to the cumulative separations of the driver and driven elements; and resilient bias means for restoring the assembly to its minimum length in the absence of the externally applied force.
[0009] Such devices are very compact and rugged and, in contrast to the prior art devices of U.S. Pat. No. 4,433,879 and GB 2331568 which are essentially static and have no guide system or return mechanism, are suitable for many dynamic precision applications such as positioning actuators or measured stroke fluid delivery devices, such as syringes for medication or for fuel dispensers. Reciprocation may also be produced by continuous rotation and used in pump applications.
[0010] Using a stack of elements allows for a much greater, cumulative extension for a given rotation and is made possible by the coupling of the driver elements for rotation while allowing their linear separation.
[0011] This is preferably implemented by providing at least the driven discoidal elements intermediate the ends of the stack with axially aligned bores, each driver element having a projection extending axially from one face which extends through the bore of its adjacent driven disc and locates in a recess in a proximate driver element in keyed, slideable engagement therewith so that rotational drive force can be transmitted between driver elements while allowing relative sliding motion in an axial direction.
[0012] Preferably each said driver element recess is part of a bore through the driver element and said projection is preferably part of at least one rib formed on the inner surface of the bore of its corresponding driver element, which rib projects outwardly from its driver element discoidal portion and engages at least one complementarily oriented rib portion in the bore of the proximate driver element to provide said keyed slideable engagement.
[0013] Although other arrangements would be possible, one preferred arrangement is for the bore in each intermediate driver element to be provided with two diametrically opposite ribs each extending over a 90 degree arc of the bore, said ribs being keyed into engagement with a similar pair of ribs in a proximate driver element oriented at 90 degrees to the first mentioned pair of ribs.
[0014] The preferred way of preventing rotation of the driven elements is to provide them each with a plurality of peripheral lugs, the mechanism further including grooved guide means surrounding the stack in which the lugs locate to prevent rotation.
[0015] Preferably, a driver element is located at one end of the stack and has an outer surface adapted to be coupled to an external drive and an inner ramped surface and a driven element is located at the opposite end of the stack and has an outer surface adapted to deliver a translational load force and an inner ramped surface, intermediate driver and driven elements having ramped surfaces on both sides. Preferably the end driver element is fixedly mounted on an outwardly extending axial shaft, threaded externally for coupling to the external drive.
[0016] In such an arrangement, it is preferred that the mechanism includes a housing assembly for the stack, comprising a cylindrical cover to one end of which the terminal driven element is fixed, the other end of the cover terminating in a slotted flange. The housing assembly further comprises a fixed cage structure surrounding the cylindrical cover and being formed with a plurality of guide legs extending in the axial direction and passing through the slots in the flange of the cylindrical cover to constrain it to linear movement. Additionally, the cylindrical cover is provided with external grooves and the guide legs are provided with internal grooves in both of which said peripheral lugs locate, in operation, to restrain the driven discs against rotation while permitting translation.
[0017] Another preferred feature is that the resilient bias means is a coil spring trapped between the flange of the cylindrical cover and an end of the cage.
[0018] Another preferred feature is that the driver and driven elements each have a plurality of ramps per ramped surface, distributed circumferentially at evenly spaced positions. This enables an even greater ratio of displacement to angle of rotation than would be the case with a single 360° ramp.
[0019] For a single stroke application, it is preferred that the camming ramp surfaces are planar, rising at a relatively shallow angle to the plane of the discoidal elements and alternating with relatively steep return surfaces.
[0020] For a continuously rotated application, both the rising and falling surfaces of the ramps could be at the same angle or the ramped surfaces are smoothly undulating in form without discontinuity at the peaks. The latter arrangement is the more compact, in its unextended state.
[0021] For single stroke applications, the mechanism may include a stop for preventing rotation of the driver element beyond the arc defined by the ramp surface.
[0022] When provided with a drive mechanism for rotatably driving such driver elements, the displacement conversion mechanism becomes an actuator. The drive mechanism may be a motor or a manually operated crank. A continuously rotated driver element will produce a reciprocating linear output.
[0023] Such an output from a displacement mechanism including a rotatable crank for rotatably driving the driver elements is eminently suitable for a hand pump application which would require a sealed casing for enclosing the mechanism and forming a pump chamber containing a one way inlet means for permitting fluid to be drawn into the pump chamber as the mechanism contracts and an outlet for enabling fluid to be expelled from the pump chamber as the mechanism extends one way, as the crank is rotated continuously.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will now be further described, by way of example only, with reference to preferred embodiments thereof as illustrated in the accompanying drawings, in which:
[0025] FIG. 1 is a side elevation of an unextended stepped disc stack illustrating the principles underlying a displacement mechanism according to the invention;
[0026] FIG. 2 is an end elevation of one of the discs making up the stack of FIG. 1 ;
[0027] FIG. 3 is a side elevation of the disc stack of FIG. 1 in a partially extended state;
[0028] FIG. 4 is a side elevation of the disc stack of FIG. 1 in a fully extended state;
[0029] FIG. 5 is an exploded view of an assembly of driver and driven stepped discs forming part of a displacement mechanism according to the invention;
[0030] FIG. 6 is an enlarged exploded view of two driver and one driven disc at one end of the assembly of FIG. 5 ;
[0031] FIG. 7 is an isometric perspective view of the assembly of FIG. 5 in its unextended state;
[0032] FIG. 8 is an isometric perspective view of the assembly of FIG. 5 in a partially extended state;
[0033] FIG. 9 is an isometric perspective view of the assembly of FIG. 5 in its fully extended state;
[0034] FIG. 10 is a side elevation of a portion of an unextended undulating disc stack illustrating the principles of an alternative displacement mechanism according to the invention;
[0035] FIG. 11 is an isometric perspective view of one of the undulating discs making up the stack of FIG. 10 ;
[0036] FIG. 12 is a side elevation of the stack of FIG. 10 in a partially extended state;
[0037] FIG. 13 is a side elevation of the stack of FIG. 10 in a fully extended state;
[0038] FIG. 14 is an exploded view of an assembly of driver and driven undulating discs forming part of a displacement mechanism according to the invention;
[0039] FIG. 15 is an enlarged exploded view of driver and driven discs at one end of the assembly of FIG. 14 ;
[0040] FIG. 16 is an isometric perspective view of the assembly of FIG. 14 in its unextended state;
[0041] FIG. 17 is an isometric perspective view of the assembly of FIG. 14 in a partially extended state;
[0042] FIG. 18 is an isometric perspective view of the assembly of FIG. 14 in its fully extended state;
[0043] FIG. 19 is an exploded perspective view of an actuator and displacement mechanism according to the invention including either the stepped disc assembly of FIGS. 5 to 9 or the undulating disc assembly of FIGS. 14 to 18 ;
[0044] FIG. 20 shows the actuator and displacement mechanism of FIG. 19 in its unextended state;
[0045] FIG. 21 shows the actuator and displacement mechanism of FIG. 19 in a partially extended state;
[0046] FIG. 22 shows the actuator and displacement mechanism of FIG. 19 in its fully extended state;
[0047] FIG. 23 is an exploded perspective view of a modification for a pump application of the actuator and displacement mechanism illustrated in FIG. 19 ;
[0048] FIG. 24 is an exploded view of a pump employing the assembly of FIGS. 14 to 18 ;
[0049] FIG. 25 shows the assembled pump of FIG. 24 on its inlet stroke; and
[0050] FIG. 26 shows the assembled pump of FIG. 24 on its outlet stroke.
DETAILED DESCRIPTION OF THE INVENTION
[0051] In FIGS. 1 to 14 , the principles of operation of one form of displacement mechanism according to the invention will now be described. This mechanism involves a stacked assembly 100 of discoidal elements, also referred to as discs, of which three, numbered 101 , 102 and 103 , are shown in FIG. 1 . The discs are not planar but are relieved to provide four planar ramp surfaces in four sectors on opposite sides, surrounding a central bore 104 , those on one side being offset by 45° from those on the other side. Four of the ramped surfaces 105 - 108 are seen in the end elevation of the mechanism from the left hand side, looking at disc 101 , as shown in FIG. 2 . The visible edges of the ramped surfaces on the assembly 100 are drawn as continuous lines in FIGS. 1 to 4 whereas the invisible edges are dashed. The edges of the discs nearest the viewer are hatched for illustrative purposes only. Each ramped surface terminates in a steep return step, such as steps 109 - 112 in the case of the outer face of disc 101 .
[0052] In FIG. 1 , the assembly 100 is in its unextended state and the ramped surfaces of the three discs are snugly interengaged in complementary fashion to take up the minimum space. If discs 101 and 103 are rotated in the direction of the arrow shown in FIG. 2 , while the intermediate disc 102 is restrained against rotation, the camming action of the opposed ramped surfaces forces the discs to separate, as shown in FIG. 3 . The maximum displacement is achieved, as shown in FIG. 4 , after a rotation of 45°, when the stepped return surfaces at the end of the opposed ramp surfaces coincide. The maximum displacement is equal to double the height of the ramps multiplied by the number of disc-to-disc interfaces and the rotation needed to achieve it depends on the number of sectors per disc. So in this example, four sectors require a rotation of 45° to achieve maximum displacement.
[0053] How this principle is applied to a practical mechanism is illustrated in FIGS. 5 to 9 . In FIGS. 1 to 4 , no distinction was made between the discs, except for the implied restraint against rotation of disc 102 . In a practical application, it is necessary to design driver and driven discs differently. In fact, in the assembly 120 of FIG. 5 , there are several types of each disc. These consist of an input driver disc 121 , identical intermediate driven discs 122 alternating with identical driver discs 123 and 124 , and terminating in an output driven disc 125 . The driver discs 123 and 124 are structurally identical but discs 123 are in a first orientation while discs 124 are oriented at 90° to discs 123 . All the discs are stacked together in engagement with each other on a common axis.
[0054] Torque to rotate the input driver disc 121 is provided by way of an integral threaded shaft 126 by means not shown in this drawing, such as a motor or a manual crank. In order for the mechanism to extend, the drive torque must be transmitted from input driver disc 121 to all of the driver discs 123 and 124 . Also the driven discs 122 must be restrained against rotation. This restraint is achieved by means of four projecting lugs 127 on each driven disc which can locate in an external spline or similar channels, not shown in this drawing.
[0055] The communication of the drive torque cannot be by fixed linkage because the separation between the driver discs increases as the assembly extends and they move outwardly along the axis. Communication of the torque from driver disc to driver disc is thus effected by a system of projecting ribs 128 , 129 which consist of internal raised portions, formed within keyhole bores 131 and 132 within central bosses 133 of the driver discs, and external prong-like portions. The external prongs pass through bores 130 in the driven discs and engage in the keyhole bores 131 , 132 of adjacent driver discs. The prongs 128 and bores 132 on driver discs 123 are identical to the prongs 129 and keyhole bores 131 on driver discs 124 , the only difference being their relative orientation of 90° to each other in the assembly stack.
[0056] Each projecting rib extends over 90° of arc so that its extending prong portions actually key into the spaces between the ribs in the central bore of the next driver disc. Thus the driver discs 123 , 124 are keyed for rotation together and with the input driver disc 121 by means of the engagement of the pronged extensions of ribs 128 , 129 with the internal portions of the ribs 128 , 129 within keyhole bores 131 , 132 of the next driver disc. At the same time, this arrangement of prongs and keyholes allows them to slide relative to each other in the axial direction, thereby enabling the assembly to extend.
[0057] FIGS. 7 , 8 and 9 show the assembly 120 in its unextended, partially extended and fully extended states, respectively, the fully extended state again being achieved after a rotation of 90°.
[0058] Another form of displacement mechanism according to the further aspect of the invention is illustrated in principle in FIGS. 10 to 13 and a practical implementation is shown in FIGS. 14 to 18 . FIGS. 10 , 12 and 13 show a stacked assembly 150 of three discoidal elements 151 , 152 and 153 . For clarity, the outer edges of the discs are shown cross hatched in FIGS. 10 , 12 and 13 . The operation of the mechanism is very similar to that of the mechanism of FIGS. 1 to 4 , the principal difference lying in the relief of the faces of the discoidal elements.
[0059] By way of example, one of the elements 152 is shown in perspective in FIG. 11 in the initial orientation that it has in FIG. 10 . It can be seen, by noting the intersection of the disc at various points with three dashed reference circles, that instead of a ramped surface, the disc has smooth out-of-plane undulations, surrounding a central bore, 154 . Looking at the visible face of disc 152 from the right in FIG. 11 , these undulations consist of three ridges, 155 , 156 and 157 , interspersed with three valleys, 158 , 159 and 160 . On the reverse face, the ridges become valleys and vice versa. It should be noted that, although, in FIG. 11 , the discs do not appear circular but waisted, this is an effect of the undulations on the perspective view and is caused by the fact that the ridges, such as 155 , are raised with respect to the neighbouring valleys, 158 and 160 . The vertical projection of a disc onto a plane is actually still a circle.
[0060] FIG. 10 shows the assembly in its unextended state with the discs 151 - 153 in a relative rotational orientation which takes up the minimum space. In this orientation, the discs interfit snugly with their undulating surfaces in full contact so that the ridges and valleys of each disc surface nestle in the valleys and ridges respectively of an adjacent disc surface. In this example, it is assumed that all the discs or at least discs 151 and 153 can move axially. It is further assumed that disc 152 can be rotated while discs 151 and 153 are restrained against rotation.
[0061] The effect of rotation of disc 152 , as shown in FIG. 12 is to drive the discs 151 and 153 away from disc 152 by camming action, as the rising slopes of the opposed surfaces bear on each other. Note the new position of ridge 155 of driver disc 152 , corresponding to a rotation of 30°. Ultimately, after a total rotation of 60°, as shown in FIG. 15 , the assembly is fully extended with the ridges of the undulating disc surfaces aligned.
[0062] A practical assembly 161 , operating according to the principles of FIGS. 10 to 13 is shown in exploded perspective view in FIG. 14 and a portion of the assembly is shown enlarged in FIG. 15 . Similarly to the stepped disc version, the undulating disc stack is made up of a unique input driver portion, connected directly to threaded input drive shaft 162 . The input driver portion is relieved on its inner face similarly to driver discs, 164
[0063] The driver discs 164 are all identical but have successively different orientations in the stack. Each drive has a central bore 165 . Identical driven discs 166 are located between each pair of driver discs. The stack terminates in a driven output disc 167 , seen on the right in FIG. 14 . This has a relieved inner face but a blank outer face for transmitting linear output force.
[0064] Drive is communicated from the input drive shaft 162 , via its driver portion to the driver discs 164 which are able to separate axially, by means of a system of prongs and keyholes similar to that of FIGS. 5 and 6 . However, because of the lack of depth of those discs, it is necessary to have 4 pairs of shorter prongs 169 instead of the two shown on the stepped type. These are shown schematically in dashed outline in FIGS. 14 and 15 . As can be seen from the orientation of the prongs in the drawing, successive driver discs are rotated by 90° with respect to the next driver disc. The prongs pass through central bores in the driven discs and key into correspondingly shaped recesses in the bores 165 of other driver discs and of the input driver portion on shaft 162 . Because the discs are so thin, the prongs actually pass through and key into more than a single neighbouring driver disc in the stack.
[0065] The driven discs 166 are each restrained against rotation by a system of four lugs 168 , located 90° apart on the circumference of the driven discs. These engage in splined external channels, not shown in this drawing. As the driver discs are rotated, the assembly expands owing to the camming action between driver and driven discs.
[0066] The assembly 161 is shown in FIGS. 16 , 17 and 18 in its unextended, partially extended and fully extended states, respectively. In comparison with the stepped disc assembly 120 of FIGS. 7 to 9 , the extension is the same for the same amount of relief but it will be noted that the discs of assembly 161 can be packed much more closely in their unextended state. Thus a much more compact actuator can be produced using the undulating discs or else a much greater extension can be used by packing more discs into the same initial length assembly. These illustrations show how fewer undulating discs achieve the same offset as the stepped version and could possibly achieve an offset of 200% of their initial unextended length.
[0067] Turning now to FIGS. 19 to 22 , the incorporation of the assemblies 120 or 161 into a complete rotary to linear displacement mechanism in an actuator will be described. FIG. 19 is an exploded view of the actuator, which has a common structure capable of accommodating either the stepped disc assembly 120 or the undulating disc assembly 161 , both of which are shown in their unextended state. In fully assembled form in FIGS. 20 to 22 , only the stepped disc version is shown but it will be understood that it is interchangeable with the undulating disc version. However, the following description will refer only to the stepped disc version, for brevity.
[0068] An annular base plate 170 supports the moveable portions of the actuator by means of two bearing races 171 and 172 in which the drive shaft 126 is mounted for rotation. A drive mechanism 173 comprises a hub 174 , threaded onto shaft 126 which hub is itself rotated by a crank 175 . The drive mechanism 173 could equally well be an electric motor such as a stepper motor or servo motor.
[0069] The assembly 120 is housed in a cylindrical piston-like cover 180 which is of the same length as the unextended assembly 120 . At its open end, the cover 180 terminates in a flange 181 , provided with four slots 182 . These slots locate slideably on the exterior of four guide legs 183 , secured to the base plate 170 at one end and bolted to a collar 184 at the other end to form a cage for the piston cover 180 . The cover 180 is free to move axially and to protrude through the collar 184 when driven by the expanded disc assembly. The other end of the piston cover is bolted to an end plate 185 , for delivering the output of the actuator. To restore the actuator to its original state, that is, with the assembly contracted, a return spring 190 is located between the piston cover flange 181 and the collar 184 to provide a resilient bias against expansion. The return spring is a compression spring and bears on the flange 181 and the collar 184 .
[0070] In order to prevent the driven discs of the disc assembly from rotating, the lugs 127 of the driven discs in assembly 120 locate in narrow channels 191 running along the piston cover 180 in an axial direction. Since, however, in its expanded state the disc assembly is much longer than the cover 180 , the guide legs 183 are also provided with further internal grooves 192 , aligned with grooves 191 on the piston cover. These grooves 191 and 192 ensure that the lugs 127 of driven discs 122 are always engaged to prevent rotation.
[0071] The operation of the actuator can be better understood by looking at FIGS. 20 to 22 . In FIG. 20 , the actuator is in its unextended state. Operation of the crank 175 in the direction of the arrow rotates the hub 174 and drive shaft 126 to cause expansion of the disc assembly 120 . This forces the piston cover 180 outwardly against the action of the return spring 190 , guided by guide legs 183 , as shown in FIG. 21 . In FIG. 22 , the piston 180 is fully extended.
[0072] If the described actuator is to be used in applications requiring a single stroke, such as precision positioning or dispensing of a measured volume of fluid, then it is desirable to limit the travel to prevent the discs overshooting their maximum displacement.
[0073] The displacement of the actuator of FIGS. 19 to 22 is limited by the action of the cover flange 181 fully compressing the spring 190 against the collar 184 as shown in FIG. 22 . This stops rotation of the stepped discs beyond their maximum displacement, which would result in an abrupt return as return steps 106 of adjacent discs slipped over each other. If the piston cover were slightly longer, it would be possible to drive the mechanism with a continuously rotating input and produce a reciprocating motion. Clearly, this would be smoother if the undulating disc assembly were used, as this has equally smooth stroke and return slopes but the return stroke is faster with the stepped version.
[0074] In comparing the two types of disc, the major advantage of the undulating version is that it is particularly compact when unextended and therefore is more suitable for applications having a limited space.
[0075] A variant of the assembly of FIGS. 19 to 22 which is more suitable for a pump application is shown in FIG. 23 . This is largely identical to FIG. 19 , identical parts being identically numbered, but includes a larger base plate 197 , a secondary piston cover 193 , in place of end cap 185 and an outer casing 194 in which sits an O-ring 195 . The secondary piston cover 193 slides up past the O-ring, secured in the recess at the end of the outer casing 194 and is restrained from over extension by a flange 196 at the foot of the outer piston cover. The secondary piston cover is thus able to pump fluid without leakage from the cylinder formed by the outer casing.
[0076] FIG. 24 illustrates the application of the undulating disc assembly as described in FIGS. 14 to 18 to a pump. The assembly 161 is mounted in a pump barrel 200 and driven against a compression spring 201 at the end of the barrel having an outlet valve 202 . The inside of the barrel is splined or grooved to constrain the driven discs of the assembly to linear movement only, by engagement of lugs 168 with the grooves.
[0077] The assembly is driven, in a similar manner to FIG. 19 by means of a crank handle 203 and hub 204 . The hub 204 and the input drive shaft 162 are mounted in bearings 205 located in a threaded end cap 206 at the opposite end of the barrel to the outlet valve. Because the barrel is long enough to permit the discs of assembly 161 to rotate continuously, the assembly expands and contracts in reciprocating fashion to produce the pumping action. A disc 207 acts as a one way seal to permit air or other pumped fluid to be drawn into the outlet end of the pump barrel.
[0078] Although the stepped disc mechanism could also be used, the undulating version offers a smoother reciprocating action, albeit with a slower return action.
[0079] FIG. 25 shows the assembled pump at one extreme of its inlet stroke, with the assembly 161 fully contracted. FIG. 26 shows the assembled pump at the extreme of its outlet stroke, with the assembly 161 fully extended.
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A rotational to linear displacement conversion mechanism comprises: an assembly including a plurality of driver discoidal elements and a plurality of driven discoidal elements mounted alternately on a common central axis to form an interleaved stack. Each discoidal element has a ramped surface, the ramped surfaces of adjacent elements being complementarily shaped and opposed so that, when in contact and completely interengaged, they form a stack of minimum length. A coupling means is provided for coupling the driver discoidal elements for rotation together about the axis by an externally applied force while permitting them to translate along the axis. The driven elements are mounted in such a way as to permit translation along the common axis while preventing rotation of the driven elements about the common axis. A rotational displacement of the driver elements by such an externally applied force causes the elements to separate by camming action of their interengaged ramp surfaces so as to produce an extension of the stack corresponding to the cumulative separations of the driver and driven elements. Finally, a resilient bias means is coupled to a driven element in such a way as to restore the assembly to its minimum length in the absence of the externally applied force.
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BACKGROUND OF THE INVENTION
This invention relates to a sewing machine and more particularly to a sewing machine in which the needle thread taking up lever is almost nested or housed unrevealedly within a housing defined by the end face of the usual arm and an end cover to be attached to the end face and further the path through which the needle travells is also unrevealedly nested within the arm as much length as possible for safety of the operator and neat appearance purpose.
For attaining such sewing machine, the thread guiding eye at the extremity of the usual needle thread taking up lever is preferred to be of the opened eye type rather than the known small hole type because of readiness in lacing the needle thread within the opened guiding eye and accordingly readiness in threading up the machine free from affection of unapproachableness of the nested lever.
However, a problem exists in providing the slot type guiding eye in the lever, particularly in preventing the needle thread from being fallen off such opened eye by virtue of a ballooning of the travelling needle thread when the lever is on its stroke to slacken the loop of the thread passing through the eye.
While various means have been provided to be fitted with the sewing machine of this character in order to prevent the thread from being fallen off the guiding eye of opened slot type, none of them have proven to be sufficient.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide a sewing machine having the needle thread taking up lever and the path through which the needle thread travels almost unrevealedly housed within a housing defined by the end face of the arm and a cover to be attached thereto for safety and neat appearance purpose.
Another object of the invention is to provide a sewing machine of this character which is free from affection of the unapproachably nested lever in lacing the needle thread within the thread guiding eye of the lever.
Still further object of the invention is to provide means for preventing the needle thread from being fallen off the eye of the lever on its loop slackening stroke.
Still yet further object of the invention is to provide a path for the needle thread unrevealedly defined as long length as allowable within the housing.
Still yet further object of the invention is to provide means to facilitate threading up of the machine by a series of sequent indications at the guiding eyes of the needle thread in accordance with advancement of the travelling needle thread.
With these objects and others in view, the present invention comprises generally a hollow arm extending from the usual known base upright and then horizontally, a needle bar vertically slidable at the end portion of the arm and carrying at the lower end thereof a thread carrying needle, a needle thread taking up lever having an opened type thread guiding eye, mechanisms for reciprocating vertically the needle bar and for swivelling the taking up lever in synchronism with the needle bar in formation of stitches in the fabric, an end cover to be attached to the end face of the arm for forming a housing therewith, a separator means for defining a space within the housing of suitable volume to allow the taking lever to swivel therewithin and also prevent the needle thread from being fallen off due to a ballooning of the thread passing through the guiding eye of the lever, and a guiding path means for the needle thread unrevealedly nested within the housing for the purpose of safety of the operator and a neat appearance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing in part a sewing machine according to the present invention,
FIG. 2 is a perspective view of parts and mechanisms within a housing formed by the cover and the arm of the sewing machine of FIG. 1,
FIG. 3 is an axial cross sectional view of the machine shown in FIG. 1,
FIG. 4 is a plan view showing in part of the machine shown in FIG. 1,
FIG. 5 is an elevational view showing in part the machine shown in FIG. 1, and
FIG. 6 is a perspective view similar to FIG. 1, showing another embodiment equipped with means to indicate sequence order of thread guiding eyes when the machine is threaded up by the operator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is illustrated in the drawings as embodied in the form it may take when applied to a well known and conventional sewing machine and described only insofar as it is believed to be necessary for an understanding of this invention.
Now referring to FIG. 1, such a sewing machine may include a base (not shown) having the usual hollow upright bracket (not shown) extending upwardly therefrom, the hollow arm 1 shown in part in FIG. 1 extends in substantially usual manner over the base to present the end portion or front upright immediately over the usual needle plate (not shown) provided in the base. The end portion of the arm may provide bores or other suitable guides in which may slide presser foot bar 4 and needle thread bar 5 (shown in part) other than means according to the invention. In arm 1 may be positioned a main shaft 6 (shown in part) from which, by the usual mechanism herein described, reciprocating motion is imparted to the needle bar 5. As usual, a pulley (not shown) is attached to the shaft 6 at the end thereof extending outwardly of the arm 1 for association therewith of a belt or other suitable means for driving the machine.
Turning to the mechanism that provides for the usual sewing function of the machine, a counter weight driving crank 7 driven by the rotary arm shaft or main shaft 6 is operatively connected to the needle-bar driving stud 8 by an arm 9. The stud 8 is fast on the needle bar 5 by a set screw 18. The main shaft 6 also drives a needle thread taking up lever 10 through means of a cam 11 secured thereto and adjacent to a lug 12 uprising from the internal face of the wall of the arm 1, for providing therein a bearing of the main shaft 6. The cam 11 is of the known cylinder or barrel type in the body of which is milled a continuous groove 13 being engaged engaged by a roll 14 of the follower lever 10.
Two lugs 15 and 16 uprise from the internal face of the arm 1 so as to secure a stud 17 thereto by means of a set screw 19 for providing the thread taking up lever 10 with a pivot about which may swivel the needle thread taking up lever 10, with its roller 14 engaging the groove 13 in the cam 11.
What has been thus far described is a sewing machine of previously provided structure, as commonly used in the art.
The sewing machine of the present invention is further characterized in that, a cover 20 is attached to the end face of the arm 1 in a manner such that the guide plate 3 (FIG. 2) and its associating parts are lamost housed unrevealedly therewithin, so that the needle thread taking up lever 10 is housed in the end cover except that the lever projects its extremity at its uppermost stroke end through a slot 21 in the cover 20 as shown in FIGS. 3 and 1.
As seen in FIG. 2, the guiding plate 3 has an upper thread guiding eye 22 and front guiding eye 23, each being of opened slot type so as to provide an entrance through which the needle thread T is laced within the eyes when the machine is threaded up by the operator, as shown in FIG. 2 in full line. The guiding plate 3 further has a third or middle guiding eye 24 also of opened slot type so as to lace the thread T therewithin. The eyes 22 and 23 either has their rims 25 and 26 protrude outwardly of the end cover 20 as seen in FIG. 1 in order to provide means for lacing the thread T into them when the machine is threaded up.
As will be seen in FIG. 2, the guiding plate 3 is of inverted U-shape and the internal vertical edge 27 is in sliding engagement with a collar 28 fast on the presser bar 4 by means of a set screw 29. A lifting up lever 30 is so pivoted to the guide plate 3 by means of a pin 32 that its cam portion 31 may be within an engagement reach of the collar 28. The presser bar 4 is normally urged downward by the usual spring (not shown) and the presser foot (not shown) carried by the bar at its lowermost end cooperates with usual feed dogs (not shown) to feed the fabric. Of course, the presser foot may be lifted free of the needle plate in the usual manner by upward swinging the lever 30 and cam and bar arrangement of this kind are self-locking against the reversal of the side thrust developed due to the profile of the cam portion 31 when the bar 4 is at the uppermost end of stroke.
As shown in FIG. 2, the guiding plate 3 has a right angled flange 33 at the front side thereof. Such provision is for the sake of mere separation of a space for the lever 10 from the remainder within the cover 20, so that the lever 10 and thread T may be prevented from any dirt.
Adjacent to the flange 33 is an elongated square hole or window 34 through which freely passes the needle thread taking up lever 10. The guide plate 3 is secured to the end face of the arm 1 by means of suitable number of holes 35 in the plate 3 and corresponding number of screws to be threaded into the end face of the arm 1. Ther peripheral profile of the guide plate 3 is identical with that of the end face of the arm 1 as well as the cross section of the cover 20 except that the rims 25 and 26 are slightly projcted outwardly of the end face profile as will be seen in FIG. 1. The guide plate 3 is further provided with a tension device generally designated in FIG. 2 by the numeral 36. The device is shown in this instance in the form of a pair of two washers 37 and threaded rod 38 projecting therethrough. A knurled handle 39 (FIG. 5) engages a nut member (not shown) meshing with the rod 38 and by screwing the nut member by rotating the handle 39 the thread nipping pressure of the washers 37 is determined through a usual coiled spring (not shown) around the rod 38.
The cover 20 is of a opened box form and provided with a separator within its internal space as seen in FIG. 3. The separator 40 is formed of a sheet metal projecting from the internal end face of the cover and an arcuate edge 41 generally concentric with the curvature of path of the eye 42 of the taking up lever 10. The arcuate path 42a of the eye 42 is concentric with and diametrically larger than the arcuate edge 41 of the separator 40 as seen in FIG. 3 so that the thread is prevented from being fallen off the eye 42 in the lowering stroke of the lever 10 by an ability of the separator 40 to limit a ballooning of the thread in cooperation with the front internal face of the cover 20. It has heretofore been known in the art that the thread loop is slackened owing to the abrupt lowering stroke of any thread taking up lever of the type, although the usual feed pick up spring is presented in the passageway to be passed by the thread. The slackened thread loop tends to be formed into a ballooning at the portion passing through the guiding eye of the needle thread taking up lever.
As shown in FIG. 2, the needle thread T is supplied from any suitable spool or other source of supply on a peg 47 which need not be specifically designated here through the upper guiding eye or slot 22, middle eye 24, tension device 36, front guide eye 23, slot type eye 42 at the extremity of the lever 10 to the eye of the thread carrying needle (not shown). As will be seen in FIG. 2, the thread runs along the left side face of the guide 3 between the upper eye 22 and middle eye 24 while running along the right hand side of the guide plate between the tension device 36 and the front eye 23 as shown in dotted line and thereafter restores the left-side location.
In order to allow such passageway of the needle thread T, three clearances are formed as designated by the numerals 44 to 46 respectively, in FIGS. 4 and 5. The upper clearance 44 is formed between the left side face of the guide plate 3 and the upper end face of the edge of the cover 20, and clearances 45 and 46 are provided at both sides of the guide plate 3 relative to the end face of the arm 1 and the front edge of the cover 20 respectively as best shown in FIG. 5. In order to ensure such clearances when the cover and guide plate 3 are installed, the end face of the arm 1 and edge of the cover 20 are formed correspondingly with indentations as will be seen in FIGS. 4 and 5.
In threading up the machine, the operator is merely required to have the thread from the supply source pass through the series of guiding eyes along a path shown in thicker full lines in FIGS. 1, 4 and 5 in exaggeratedly slackened condition of the thread, and then required to finally thread the thread carrying needle as usual. Thereafter, by once placing the thread under a sufficient tension, the needle thread is self lacing within all the clearances 44 to 46, so that the threading up of the machine is completed without any conscious effort by the operator.
Instead of the separator 40 of the cover 20, the flange 33 of the guide plate 3 may be enlarged as shown in phantom in FIG. 2 by the numeral 33' so that the needle thread may be prevented from being fallen off the eye 42 of the needle thread taking up lever 10 in the same manner as that practiced by the separator 40. In this embodiment, the vertical edge 33a of the flange 33' locates leftwardly of the path 42a of the eye 42 (FIG. 3) in order to limit the ballooning of the needle thread passing through the eye 42 when the lever 10 is on its slackening stroke.
In order to facilitate to thread up the machine, a series of continuing marks or symbols and the like are provided, in this instance, continuing numbers encircled as shown in FIG. 6, at positions in the face of the arm adjacent to the rod 47 and the three guide eyes 22 to 24.
As described in the foregoing, the machine according to the invention has three principal advantageous features. The first one is that the needle thread taking up lever 10 is unrevealedly nested within the cover 20 so that the operator is normally free from any injury as would otherwise be feared.
The second one is readiness of threading up the machine because of no closed small hole type guiding eye except the thread carrying needle.
The third one is that the threading up of the machine is enabled to be further ready for any one lacking experience by providing a series of sequent marks, such as for example, sequent numerals, at positions adjacent to the corresponding guiding eyes along the path to be traced by the ravelling needle thread.
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A sewing machine having the usual type needle thread taking up lever and the path through which the needle thread travels almost unrevealedly nested within a housing defined by the end face of the arm and a cover to be attached for safety purpose and additionally neat appearance purpose. The sewing machine is further characterized by provision of a separator within the housing in parallel with an internal front face of the cover so as to provide the lever with a space of suitable volume for preventing a loop passing through a thread guiding eye of the lever from being fallen off the eye when the lever is on its slackening stroke.
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[0001] This Application claims priority from Provisional Patent Serial No. 60/441,005 filed Jan. 17, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a method for the reduction of mercury emissions from coal gasification processes. More particularly, it refers to an improved method for removal of mercury through the use of alkali additives in coal gasification and staged coal combustion processes.
[0004] 2. Description of the Prior Art
[0005] The 1990 Clean Air Act Amendments identified 189 substances that were designated as hazardous air pollutants (air toxins). These substances are chemicals, including heavy metals and organic compounds in both solid and gaseous forms, known to pose a risk to human health. One metallic element, mercury, is getting much attention due to its quantity and toxicity.
[0006] Mercury emissions to the air and releases to water occur naturally and by human activities. According to a fairly recent emissions inventory (1994-1995), in the United States the major emitters of mercury to the atmosphere were electric utilities, municipal waste combustors, commercial and industrial boilers, medical waste incinerators, and chlor-alkali plants. Until the middle of the decade, municipal waste combustors, hazardous waste combustors, and medical waste incinerators were the leading emitting source category. The United States Environmental Protection Agency (hereinafter “EPA”) now regulates these industries, and the EPA estimates that emissions from municipal waste combustors and medical waste incinerators declined by 90% from 1990 to 2000. This currently makes coal-fired utilities the leading man-made source of air-borne mercury emissions in the U.S. Of the estimated 5,000 tons of global mercury emissions emitted to the atmosphere in 1994-95, U.S. coal-fired power plants contributed about 51 tons, or 1%. This rate of mercury emissions represented 33% of the 158 tons of mercury released in the U.S. for the same time period.
[0007] There are several methods for removing elemental mercury and its compounds from combustion/incineration flue gas. Elemental mercury removal is somewhat difficult because mercury remains in the vapor phase at very low temperatures ( boiling point at 674° F.) and does not condense on ash particles in the flue gas stream so that it may be removed with electrostatic precipitators. However, removal of mercury from combustion flue gas (U.S. Pat. No. 4,889,698 and U.S. Pat. No. 5,672,323)) using activated carbon adsorption is known in the prior art. There are also other methods of removal; they include the use of oxidizing agents that convert elemental mercury to its soluble compound forms (U.S. Pat. No.5,900,042) so that it may be scrubbed from the flue gas. Another method, U.S. Pat. No. 6,214,304, uses alkali sulfides to convert elemental mercury to mercury sulfide that is removed by particulate control devices. Another method uses alkali injection into the boiler furnace (U.S. Pat. No. 6,372,187); it has been shown to be somewhat effective in reducing mercury emissions. However, these methods, if highly effective (90% removal) like carbon adsorption are very expensive techniques (as high as $100,000/lb of removal). The oxidizing method (U.S. Pat. No. 5,900,042) and the alkali furnace injection method (U.S. Pat. No. 6,372,187) although less expensive, only remove 50 to 55% of the mercury.
[0008] It would therefore be advantageous to have an improved mercury capture technique that will reduce coal mercury emissions to the atmosphere and do so at a relatively low cost. The method of the present invention is inexpensive and is as effective if not more effective than the carbon adsorption method.
SUMMARY OF THE INVENTION
[0009] I have discovered a process employing a staged combustor to remove mercury in an alkaline molten slag. High levels of mercury capture were found to be an inherent feature of a staged combustor (see U.S. Pat. Nos. 4,395,975, 4,423,702 and 5,458,659) developed for the reduction of sulfur and nitrogen oxides to the atmosphere. Alkali compounds, such as limestone, lime, hydrated lime, dolomite, trona, nacholite or combinations thereof are added with the coal being fired in the first stage of the combustor, or are added separately into the first stage of combustion operating at 2400 to 2700° F. The first stage of combustion, in effect, is a coal gasifier operating at an air to fuel stoichiometric ratio of around 0.60. Sulfur and high levels of mercury capture are achieved through capture in the alkaline molten slag produced from the partial oxidation of any carbonaceous fuel, including coal, by incorporating a combustor design that yields a reducing condition in the alkaline molten slag sulfur capture zone. Nitrogen oxide emissions are also reduced by firing the coal in a substoichiometric air condition in the first stage that reduces NO x production from the oxidation of fuel bound nitrogen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A more complete understanding of the invention can be obtained by considering the following detailed description in conjunction with the accompanying drawings, wherein;
[0011] [0011]FIG. 1 shows a schematic of a staged combustion system applied to a coal-fired boiler; and
[0012] [0012]FIG. 2 shows the thermo chemical equilibrium for calcium and magnesium oxide reactions with carbon to form elemental calcium and magnesium.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] It is believed that the reaction mechanism for mercury capture in a molten slag bath gasifier involves the formation and capture of amalgams in complex mineral composites. Mercury will form amalgams with many alkali metals, alkaline earth metals, zinc, cadmium (Ca), arsenic, antimony, gold, silver and copper. Other metals like molybdenum, manganese, cobalt and particularly iron are nearly insoluble in mercury. It is believed that the high melting point alkaline earth metals Ca (melting point of 2192° F.) and Magnesium (Mg) (melting point of 2030° F.) that are combined with their oxide forms CaO (melting point of 4658° F.) and MgO (melting point of 5072° F.) are the alkaline earth metals that are forming amalgams with mercury. Under reducing conditions with carbon as the reducing agent for a gasifier temperature range of 2400 to 2700° F., both elemental calcium and magnesium can form; see the thermo chemical equilibrium coefficients for these reactions in FIG. 2. Although the equilibrium coefficients are low, still there would be orders of magnitude more concentration of elemental calcium and magnesium to react with all of the mercury in the coal. Since the coal is fired into the alkaline molten slag bath with enough force to swirl the slag, there should be plenty of carbon formed to create some quantity of elemental calcium and magnesium. Carbon monoxide will also react with the oxides of calcium and magnesium to form elemental calcium and magnesium but the reactions are not quite as favored as the reactions with carbon.
[0014] To achieve high mercury capture, the combustor is designed to provide for 1) intimate mixing of the carbonaceous fuel and its reactants with the reduced alkaline molten slag, and 2) intimate fuel/air mixing, done in such a way as to eliminate the formation of localized pockets of unreacted oxygen. By keeping the molten slag in a hot reducing condition (2200 to 2700° F.), carbon and carbon monoxide react with certain metals to convert a portion of those metals to their elemental form that will then combine with mercury to form an amalgam; for example:
CaO solid +C solid →Ca solid +CO gas
CaO solid +CO gas →Ca solid +CO 2 gas
[0015] Mercury (Hg) is easily converted from its oxide and sulfide (Cinnabar) forms to elemental mercury:
HgO solid +C solid →Hg vapor +CO gas
HgO solid +CO gas →Hg vapor +CO 2 gas
HgS solid +H 2 gas →Hg vapor +H 2 S gas
[0016] For example, the elemental calcium then will react with elemental mercury to produce an amalgam that is tied up in a complex mineral composite.
Ca solid +Hg vapor →Ca o Hg o solid amalgam
[0017] The conclusion that amalgam formation is probably the cause of the nearly quantitative capture of mercury in the alkaline molten slag comes from the work done by Sir Humphrey Davy. In the early 1800's, Davy attempted to decompose a mixture of lime and mercuric oxide by an electric current and an amalgam of calcium was obtained. The separation of the mercury from the calcium was then so difficult that Davy was not sure if he had obtained pure metallic calcium. Electrolysis of lime and calcium chloride in contact with mercury gave the same results.
[0018] Laboratory analysis for a three-stage combustor demonstration, wherein the first stage was operating at an air to fuel stoichiometric ratio that ranged from 0.58 of 0.77, firing an Illinois #5 coal with 3.39 wt % sulfur and with limestone being added at a Ca/S ratio of 0.85, showed the following results, see Table 1.
TABLE 1 Mercury Capture Rate, Hg, Capture, Material: lb/hr ppmw Hg, lb/hr % Input: Coal 1669.7 0.089 0.00014860 Limestone (as CaO/MgO) 96.5 0.030 0.00000289 Total 1766.2 0.00015149 Output: Slag 38.9 2.60 0.00010110 66.7 Fly Ash 156.5 0.26 0.00004069 26.9 Total 195.4 0.00014179 93.6
[0019] Although a stack test was not completed for mercury emissions from the staged combustion system, from the weight rates and analyses of the different streams, mercury capture in primarily the first stage (gasifier) molten slag exceeded 90%. Even more impressive is that when leaching procedure tests were completed on the first stage (gasifier) slag and the fly ash removed from the flue gas baghouse, there was no leaching of mercury. Both samples of leachate yielded 0.0000 mg/l of mercury.
[0020] Mercury analyses were also completed on the ash from a coal-fired chain grate stoker at the same facility, firing the same Illinois #5 coal. The mercury in the fly ash was 0.079 ppmw and the mercury in the grate bottom ash was 0.01 ppmw. This shows that mercury capture using a stoker is very low compared to the staged combustion system. This also indicates that for mercury capture to occur, a reducing condition must exist and limestone or some other alkali must be added. Data taken from a slagging cyclone boiler operation, firing Illinois coal wherein alkalis were not added that was operating under an overall oxidizing condition showed that about 8% of the mercury was captured in the bottom slag.
[0021] A typical example of the process of the present invention, preferably using the CAIRE™ staged combustor (U.S. Pat. Nos. 4,423,702 and 5,458,659), is shown schematically in FIG. 1. Certain variations from this schematic could be made with such variations still being within the context of this invention. It will be understood by those skilled in the art that certain variations from this schematic could be made with such variations still being within the context of the present invention. In the embodiment shown in FIG. 1, a first stage combustor 10 is located in front of the entries 12 into the furnace 13 . Openings 5 into each of the combustors receive a conventional fuel such as pulverized coal 2 , and an alkaline product such as lime or limestone 3 with the carrier primary air 1 and the preheated air or oxygen 4 . Alternatively, a coal water slurry pump could be used to convey pulverized coal to the combustor. Controlled partial oxidation of the coal takes place in the combustor by regulation of the preheated (400° to 700° F.) secondary air or oxygen flow 4 . The air (oxygen) to fuel stochiometric ratio (SR) in first stage combustor 10 is maintained at about 0.40 to 0.70 (SR 1 ) through control of the preheated air or oxygen flow 4 , and most for air preferably at about 0.60. With the first stage combustor 10 , the products of partial combustion in the form of a fuel gas and the molten slag from the ash portion of the coal plus the inorganic alkali compounds are separated in the first stage partial oxidation chamber 10 , and a molten slag eutectic 7 containing alkali compounds and coal ash exit through the bottom opening 8 of the first stage combustor 10 . The molten slag is quenched in a water quench sluice system 9 and the ash is sluiced to a collection tank from where it is pumped to a settling pond, or otherwise disposed of according to conventional known methods.
[0022] The staged combustor 10 has a partial oxidation zone where mixing at a temperature of about 2200° to 3000° F. provides intimate contact between the coal and air or oxygen. Through the use of a staged combustor 10 that has incorporated molten slag removal, a high percentage (75-90%) of the molten slag produced during partial oxidation of the coal is removed from the gas prior to entry into the furnace 14 , and prior to further partial oxidation at entry 12 .
[0023] Although certain embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alterations would be developed in light of the overall teaching of the disclosure. Accordingly, the particular embodiments and arrangements disclosed herein are intended to be illustrative only and not limiting as to the scope of the invention which should be awarded the full breadth of the following claims and in any and all equivalents thereof.
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Method for removing mercury emissions from the burning of coal or other carbonaceous fuels, such as in a power plant or from coal gasification. Alkali additives are introduced in the coal gasification and staged coal combustion processes to capture the mercury in an alkaline molten slag. The combustor is operated at a stoichiometric air or oxygen to fuel ratio of about 0.40 to 0.80 and a temperature range of about 2200°-3000° F. During the staged combustion process the molten slag containing combinations of alkali and mercury is removed and disposed of to minimize or prevent mercury from escaping in the flue gas.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a well bore cleaning tool for attachment to a well casing or the like. More particularly, it concerns a well bore cleaning tool for cleaning the walls of a well bore where there is very limited space or distance between these walls and the well casing, often referred to as "close tolerance" conditions.
2. Background of the Invention
In the drilling and completion of an oil and/or gas well, there are three basic types of cementing operations necessary. The first, termed "casing cementing", is done to seal an annular space between the well casing and the bore hole so that fluids in permeable layers may not migrate vertically in the annulus. This procedure, also referred to as "primary" cementing, involves pumping a desired volume of cement slurry down the casing and back up the annular space a required distance toward the surface. "Channeling" or partial by-passing of the cement slurry past the drilling mud media in the well bore often results in primary cement jobs of poor quality, requiring secondary or "squeeze cementing" if the primary cementing of the casing was inadequate in sealing or supporting the casing string. This second type of cementing operation in well drilling and completion requires pumping of a cement slurry under very high pressure through holes which must be perforated through the casing at precise levels. It can reduce the oil or gas producing capability of a well due to filling the permeable section of the reservoir rock with drilling mud and cement. It is also very costly from the standpoint of the additional time and expense of the extra operations required. It has been demonstrated and documented in both laboratory testing and field operations that rotation of the casing, while cementing, is one of the most important factors in obtaining successful primary cement jobs consistently. The number and size of casing strings required for a well depends on its planned depth and the pressures anticipated at the various sub-surface levels in the area. Typically, deeper wells require a number of concentric strings of casing to be run and cemented in progressively smaller hole sizes to line the newly drilled hole interval to contain the ever-increasing pressures which normally occur in deeper rock layers. For example, a bit which is used to start the well at the surface may be 26" in diameter to drill a 26" hole down to the first casing setting level, where a 20" O.D. casing is installed and cemented. The next bit would be 171/2" in diameter to drill that size hole down to the next required level, where a 133/8" O.D. casing is installed and cemented. The next bit would be 121/4" in diameter to drill down to the next critical level, where a 95/8" O.D. casing is installed and cemented. The next bit size would be 81/2" in diameter to drill the hole down to the next casing level, where a 75/8" O.D. casing is run and cemented, usually as a "liner", which is defined as a short casing string which covers only the open hole interval plus a small overlap into the bottom of the previous casing to save the expense of running the entire length of the 75/8" O.D. casing back to the surface. A 61/2" bit is then used to drill that size hole below the 75/8" casing liner down to the next critical level, where a 51/2" O.D. casing could also be run as a "liner". If the objective zone has still not been reached, a 45/8" bit is used to drill below the 51/2" O.D. casing liner in preparation for a well completion in a still smaller casing size. From this example, it becomes evident that the annular space available between the bore hole and the casing or casing liner in deep wells is very limited and a cleaning tool which can be used safely to aid in the successful primary cementation of casing under such limited clearance conditions is greatly needed in the oil and gas industry to improve the quality of well completions while reducing their ultimate cost.
The setting of "cement plugs" is the third type of cementing operation sometimes required in drilling of oil and/or gas wells. It consists of filling up the drilled borehole over a specified vertical interval, usually ranging from a few hundred feet to a thousand feet or more in length, with cement to effect a "cement plug", for the purpose of abandoning a well found to be dry or depleted of oil or gas, or to change the direction of drilling to drill around a section of drill pipe or casing which may have become "stuck" and prevented deeper drilling, or to direct the drilling of the borehole in a different direction to a more favorable subsurface position to find the oil or gas reservoir. In setting "cement plugs", it is desirable to do so with pipe smaller than the drill pipe, since its removal, after the cement slurry has been pumped into place, does less to disrupt the ability of the cement to form a solid barrier in the borehole.
Whether cementing casing or setting "cement plugs", it is desirable for the walls of the well bore to be mechanically cleaned of the uncirculatable mud media, sometimes called "mud-cake", using abrading devices of cable or wire, known as "scratchers", to prevent contamination of the cement slurry by the chemically treated drilling mud and permit better bonding of the cement to the cleaned bore hole.
One common type of well bore cleaner is one which comprises cable and collars, the collars fitting on a pipe casing, and a cable or cables connected between the collars. The collars are securely attached to the casing, such as by welding or using set screws. Once the collars are attached to the pipe casing, the pipe casing is inserted into the well bore and, depending upon the particular arrangement of the collars and cables, the pipe casing is either rotated or reciprocated (or both), during which process the cables frictionally contact the well bore walls and loosen up the mud cakes; at the same time, cement is pumped through the bottom end of the casing upward and displaces the drilling mud and the mud cakes, which are loosened by the well bore cleaners, from the annulus. In some cases, wire is tied or otherwise attached to the cables in order to aid in cleaning the bore walls, as can be seen in U.S. Pat. Nos. 2,868,298 and 2,868,299. The well bore cleaning tools disclosed in these patents comprise, as do all well bore hole cleaning tools comprising cables and collars with which the applicant is aware, either a plurality of cables, or a single cable which is twisted around the casing to form a helix.
The limitation of previous rotating type cleaning devices, known to the applicant as "scratchers", has been that their cleaning fingers or loops are mounted on longitudinal metal strips, usually five feet long. These have certain disadvantages when used in close tolerance annular conditions encountered in deeper wells; their installation without welding requires separate stop devices, the combination of which protrudes from the casing surface too far to be safely used; the protruding devices may contact a ledge and any minor slippage of one stop device will cause the longitudinal base strip to buckle or break off and jeopardize lowering the casing or liner further to the desired setting depth. Additionally, the void space under the longitudinal strip, between it and the casing surface, is difficult, if not possible, to fill with cement, leaving a new area in the annulus for undesirable vertical fluid migration.
The scratcher shown in the applicant's U.S. Pat. No. 4,159,742 cleans by either reciprocation or rotation of the pipe, but its design is for setting cement plugs using smaller diameter pipe (then the drill pipe) where annular tolerances are not close, plus its 360 degree wall abrading design could be detrimental when lowering the casing in a deep close tolerance hole where there is a delicate mud balance between losing mud (to formations) and having one or more of the uncased permeable zones in the well trying to flow.
For the above reasons, the cleaning tools known to the applicant cannot be used as safely or effectively in close tolerance annular conditions as the well bore cleaning tool of the present invention.
SUMMARY OF THE INVENTION
The present invention overcomes the above mentioned disadvantages in a bore hole wherein there is a limited clearance or amount of space in the annulus.
The present invention is a well bore cleaning tool which comprises a plurality of collars which slip onto a pipe casing without welding, and can be securely attached thereto using any conventional securing means, such as set screws, and a cable which is disposed longitudinally on one side of the casing, substantially in a straight line. The well bore cleaning tool of the present invention can be used in bore holes wherein the annulus is so small that it was impossible to successfully clean it with the devices known before to the applicant. Once inserted into the bore hole, the casing is rotated, causing the cable segments to frictionally contact the walls of the bore hole, thereby abrading and loosening the mud cake which accumulates on the walls of the hole, allowing same to flow with the rest of the drilling mud, resulting in good sealing contact between the cement and the newly cleaned bore hole walls.
The well bore cleaning tool of the present invention is adjustable. On sections of the casing which correspond to levels in the bore hole where the bore hole is of a relatively larger diameter due, for example, to a brittle or caving formation, the collars can be placed closer together such that when the casing is rotated, the cable segments will extend further from the casing in order that they may be able to frictionally contact the walls of the bore hole.
It is therefore an object of this invention to provide a close tolerance well bore cleaning tool that can be safely used in very close tolerance conditions as encountered in deeper wells where there is limited space between the casing and the wall of the well bore.
Another object of the invention is to provide such a tool that can be easily attached to a casing, without welding.
Still another object is to provide a cleaning tool that can be adapted to bore holes having varying inside diameters, which will effectively abrade and remove uncirculatable mud-cake when the casing is rotated.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature, advantages, and objects of the present invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings in which like parts are given like reference numerals and wherein:
FIG. 1 is a schematic illustration of a well bore cleaning tool of the present invention attached to a pipe casing and inserted into a bore hole.
FIG. 2 is a detailed view of the collar and a means to attach the cable to the collar in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the well bore cleaning tool of the present invention is shown to be mounted on a casing 11 within a well bore 10. The cleaning tool comprises a plurality of collars 12 to which a cable 13 is secured. The collars are slipped onto the casing 11 and are attached thereto. The casing 11 is then inserted into the bore hole 10. There is usually, in practice, only 1/2" to 3/4" clearance between the walls of the bore hole 10 and the surface of casing 11. It is in this very close area that the present invention is most useful.
The cable 13 may be secured by a suitable means to collars 12, for example, by being welded or by being inserted through a ring on the outer surface of the collar 12. Preferably, however, the cable is attached in a manner as will be described below. Collars 12 are securely attached to the casing 11 by any suitable means, such as, for example, set screws 14 inserted through apertures in each collar 12, preferably equidistantly from each other.
Tubes 20, which have an inside diameter just slightly greater than the outside diameter of the cable, are slipped onto the cable, spaced at approximately uniform intervals along the cable, and are then crimped to an L-shape to secure them to the cable. The tubes 20 are placed in L-shaped cut-outs 21 in collars 12 (similarly, L-shaped cavities could be formed in collars 12) and are tack-welded into place. Collars 12 can then be quickly and easily attached to casing 11 using set screws 14. The spacing of collars 12 is determined by the diameter of the hole which cable 13 must frictionally contact; for example, collars 12 are spaced closer together on sections of casing 11 which are intended to be in the area of the bore hole 10 with a relatively large diameter due to brittleness and/or caving of the rock strata. The distance between each successive collar 12 is selected so that the cable 13 extends a sufficient distance outwardly from the casing 11 to scratch the wall of the bore 10 (see closer collar spacing on upper end of FIG. 1 for enlarged bore hole interval). As can be seen in FIG. 1, collars 12 are mounted on the casing 11 in such a way that tubes 20 are lined up one above the other so that cable 13 extends in a single longitudinal direction vertically along the casing 11.
For convenience in installing the well bore cleaning tool of the present invention on the casing 11, it should be constructed to cover an 8 to 10 feet section of casing using 5 or 6 equally spaced collars 14 each. These individual cleaning tools should be installed in plurality, end to end, on the casing joints which will span and adequately overlap all potential oil and/or gas zones where good cement bonding is required in the annulus between the casing 11 and the walls of the well bore, allowing only enough space on each casing joint for a centralizer, and the casing handling and make-up tools. The centralizers, which may be of any suitable known construction, are used to keep the casing 11 in the center of the hole 10. Casing 11, with the tool of the present invention attached thereto, is inserted into the hole 10 and, while cement is being pumped through the bottom of the casing, is rotated. It is preferable to install the well bore cleaning tool on the casing so that the open ends of tube 20 are on the leading edge of the casing during rotation. In that manner, the resistance of the cable to bend away from the casing adds to frictional force with which the cable segments 13 contact the walls of the well bore 10. This additional force helps to assure that all caked mud will be removed from the walls of the well bore 10 with rotation of the casing 11.
Although the cable segments of the tool of the present invention have been described as being preferably aligned substantially in a straight line along the casing, it should be understood that aligning the cable segments such that they make less than 1/4 of a revolution around the casing would be an improvement over the devices known to the applicant; aligning the cable segments such that they make less than 1/2, less than 3/4, or less than 1 revolution around the casing is still superior to a tool in which the cable segments make a complete or more than one complete revolution around the casing.
In an actual trial operation of the preferred embodiment, it was found that having a single cable extending longitudinally along the side of the casing had many advantages, in contrast with any of the prior art device which include the spiraling cables or spiral brushes, etc. In particular, the longitudinally deployed cable had very little scarring effect on the bore hole wall during the lowering operation. Thus, the instant device is a safer device since it tends to dislodge much less of the wall cake or cause caving of rock strata while being deployed down the hole to the cementing location. Hence, there is less of a tendency for dislodged material to cause a constriction in the bore hole during this lowering operation.
Many changes and modifications in the above-described embodiment can be carried out without departing from the spirit or scope of the present invention. Accordingly, I pray that my rights to the present invention be limited only by the following claims.
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A well bore cleaning tool comprises a plurality of collars which slip onto a pipe casing without welding, and can be securedly attached thereto using any conventional securing means, such as set screws. The collars are interconnected with a cable, disposed longitudinally on one side of the casing, substantially in a straight line. The well bore cleaning tool has utility in bore holes wherein there is a limited clearance or amount of space in the annulus (that is, the region between the exterior of the casing and the wall of the bore hole).
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BACKGROUND OF THE INVENTION
The present invention relates to an operator unit for opening and closing a window and, more particularly, to a counterbalanced window operator.
Operators are known for moving a window between closed and open positions, for example, a window having a stationary main frame mounted in a roof of a house or other building, especially a sloped roof, and a sash hinged to the main frame at the top of the sash for pivoting toward and away from the main frame. Such operators are typically mounted on a bottom member of the main frame and connected to a bottom member of the sash for pushing the sash away from the main frame and drawing the sash into engagement with the main frame. When the window operator is actuated to move the window in an opening direction, it must overcome a component of the weight of the window, especially when the window is mounted in a roof. In order to overcome this difficulty, counterbalancing devices employing springs have been provided to counteract the weight component of the window and, thereby, reduce the force which must be applied to the operator, either by hand or by a power unit. Counterbalanced window operators are disclosed in U.S. Pat. Nos. 5,097,629 to Guhl et al. and 2,698,173 to Rydell.
SUMMARY OF THE INVENTION
The construction according to the present invention offers the advantage that a very compact design of high stability and functional reliability is obtained so that, in the closed condition of the window, the moving means of the operating member between the sash and the main frame may be completely accommodated in a fairly small housing mounted on the bottom of the main frame.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a first embodiment of a window operator according to the present invention;
FIG. 2 is a schematic view of a second embodiment of a window operator according to the present invention;
FIG. 3 is a schematic view of a third embodiment of a window operator according to the present invention;
FIG. 4 is a side schematic view of a fourth embodiment of a window operator according to the present invention;
FIG. 5 is a schematic view of a fifth embodiment of a window operator according to the present invention;
FIG. 6 is a cross section of a portion of a window sash to which the operator according to the present invention is connected;
FIG. 7 is a schematic view of a sixth embodiment of a window operator according to the present invention;
FIG. 8 is a right side view of the window operator of FIG. 7;
FIG. 9 is a schematic view of the window operator of FIG. 3 to which an electric drive unit, rather than a handle, is connected; and
FIG. 10 is a schematic view of a window having a rectangular main frame and a rectangular sash mounted for pivoting movement relative to the main frame and employing the window operator according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Common features of the embodiments of the counterbalanced window operator according to the present invention which are shown in FIGS. 1-5, 7 and 8 are that a connection between a sash of a window and an operator housing 1, 11, 21, respectively, which is mounted, e.g., at a bottom member of the main frame of the window, is provided by two pivoting arms 2-3, 12-13, 22-23, respectively, one end of each of which is pivotally journaled about a pivot point in the housing 1, 11, 21. The other end of each pivoting arm is pivotally connected with a bottom member S of the sash by means of slide shoes 2a-3a, 12a-13a, 22a-23a, respectively, slidably displaceable in the longitudinal direction of that member in tracks of a track member T secured on the bottom member S, as can be seen from FIG. 6.
The drive member for the opening movement is a non-rotatable nut member 4, 14, 24, respectively, engaged by the rotatable lead screw 5, 15, 25, respectively, operated by cranking the handle 6, 16, 26, respectively. A thrust bearing B1, B2, B3, respectively, is provided in the housing 1, 11, 21 to support the lead screw 5, 15, 25 for rotation and to withstand axial forces imposed on the lead screw. In the embodiment of FIGS. 7 and 8, thrust bearings B4 and B5 are used with a worm member 15a.
The connection between the nut member 4, 14, 24 and the pivotal arms 2-3, 12-13, 22-23 is provided by a symmetrical pair of links 7, 17, 27, respectively, having one end pivotally connected with the non-rotatable nut member 4, 14, 24 and another end pivotally connected with the respective arm 2-3, 12-13, 22-23 in a point 2b-3b, 12b-13b, 22b-23b, respectively, located at some distance from the end of the arm pivotally journaled in the housing 1, 11, 21. In the embodiment of FIGS. 7 and 8, a symmetrical pair of links 17a each has one end pivotally connected with a ratchet block 14a and another end connected with a respective arm 12-13 in a point 12b-13b located at some distance from the end of the arm pivotally journaled in the housing 11.
In each illustrated embodiment, a symmetrical arrangement of a counterbalancing spring mechanism is provided to facilitate the opening movement of the window by compensating for the weight of the window.
In FIG. 1, the counterbalancing mechanism comprises on each side a compression spring 8, such as a coil spring, pivotally connected at one end to the bottom member of the main frame outside the housing 1 and pivotally connected at an opposite end to the above-mentioned respective point 2b-3b at the respective arm 2-3 through a rigid bar member 9. Although a compression spring 8 is shown only on the right side of FIG. 1, it is understood that a like spring is connected to the rigid bar 9 on the left side of FIG. 1. As an alternative, tension springs can be used in place of the compression springs 8.
In the embodiment of FIG. 2, a tension spring 8a has been substituted for the compression spring 8. A similar tension spring (not illustrated) is connected to the rigid bar 9a on the left side of FIG. 2. The bracket member connected with the main frame of the window is located at the end of the spring 8a adjacent to the pivot arm 3, whereas the rigid bar 9a is connected with the opposite end of the spring 8a distal to the pivot arm 3.
In FIG. 3, the counterbalancing mechanism comprises a torsion spring 18 with two fingers 19 each curved around and engaging one of the pivoting arms 12-13, the torsion spring being mounted on a stationary pin 20 in the housing 11.
The embodiment of FIG. 4 is a modification of the embodiment of FIG. 3 in which links 17b between the non-rotatable nut member 14 and the arms 12, 13 allow the arms 12, 13 to pivot about an axis perpendicular to the axis of the rotatable lead screw 15. The connection between the links 17b and the pivot arms 12, 13, as well as between the links 17b and the non-rotatable nut member 14, comprise spherical joints, or ball-and-socket joints, 17c in the embodiment illustrated. Such joints permit the pivot arms 12, 13 to follow the opening movement of the bottom of the sash S as it pivots about the axis of the hinges at the top of the sash by which the sash is mounted on the main frame. The axis of the lead screw 15 is adjustable with respect to the main frame of the window by means of a slide member 20a, which is slidable in a curved slot 20b in a bracket 20c connected to the main frame and arrestable by means of arresting screws 20d.
In FIG. 5, the counterbalancing mechanism is provided by a laminated leaf spring 28 engaging and fixed at one wall 29 of the housing 21 and engaging the nut member 24.
As can be seen from FIGS. 7 and 8, which are views corresponding to the views of FIGS. 3 and 4, there is a different modification of the embodiment of FIGS. 3 and 4 by which the worm member 15a has been substituted for the threaded spindle or shaft 15 forming the screw member in FIG. 3. The non-rotatable nut member comprises in this case, not a head portion surrounding a threaded spindle, but rather two ratchet blocks 14a engaging the worm member 15a at diametrically opposite sides thereof. The ratchet blocks 14a are provided with tooth-like projections 14b engaging the worm member 15a. As can be seen in FIG. 8, this arrangement allows the axis of the screw member 15a to be inclined with respect to the ratchet blocks 14a, which are confined by guide members 14c, 14d to displacement in a plane parallel to the two arms 12, 13.
FIG. 9 shows an electric drive unit M connected to the lead screw 15 to drive the lead screw, instead of using the handle 16. The electric drive unit M can also be connected to the lead screws 5 and 25 of the other illustrated embodiments of the present invention rather than using the handles 6 and 26.
As can be seen from FIG. 10, the operator according to the present invention is for opening a window 30 having a generally rectangular main frame 32 and a generally rectangular sash 34 mounted for pivoting movement relative to the main frame about a pivot axis P generally parallel to a pair of opposed sides of the sash.
It will be apparent to those skilled in the art and it is contemplated that variations and/or changes in the embodiments illustrated and described herein may be made without departure from the present invention. For example, although the non-rotatable member has been described as a non-rotatable nut member 4, 14, 24, other members having threaded openings can be employed, and still other changes may be made. Accordingly, it is intended that the foregoing description is illustrative only, not limiting, and that the true spirit and scope of the present invention will be determined by the appended claims.
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A counterbalanced window operator includes a housing in which a rotatable lead screw, rotated by a crank handle or electric power unit, cooperates with a non-rotatable nut member to axially displace the nut member and move pivoting arms to open and close the window.
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TECHNICAL FIELD
The present invention relates to a technology for improving a fatigue strength of a cast iron material, in particular, a spherical graphite cast iron.
BACKGROUND ART
A conventional automobile transmission gear has been manufactured by carburizing and hardening a steel material after the steel material was gear cut. However, there was a problem of deformation of a member due to heat treatment strain.
By contrast, a spherical graphite cast iron can be readily manufactured. However, it has a disadvantage that it can not be used in an automobile transmission gear because of a low fatigue strength. Accordingly, it is desired for a cast iron material which was not carburized and not hardened so as to have a fatigue strength being the same as that of a carburized and hardened steel material.
A spherical graphite cast iron has a high mechanical strength in cast irons. As a technology for improving a fatigue strength of a spherical graphite cast iron, there is an austempering treatment applying to a spherical graphite cast iron containing, by weight ratio, 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu.
The bending fatigue strength at 10 7 cycles of a spherical graphite cast iron having such the composition is shown in FIG. 13 . As shown in a rotating bending test curve L of FIG. 13 where a stress (MPa) is shown in a vertical axis and the number of times of repetition of bending is shown in a horizontal axis, even a high tensile cast iron having a tensile strength such high as 1400 MPa only has a fatigue strength of about 200 MPa. This numerical value is comparable to that of a forged article, and the strength of 600 MPa or more being the same level as that of a carburized and hardened steel material is not obtained.
The fatigue strength of “about 200 MPa” can not be used in an automobile transmission gear.
As an another prior art, a technology is proposed, according to which a spherical graphite cast iron is cast to improve the fatigue strength thereof by means of adding an additive to a molten metal of a flake graphite cast iron (see Patent Document 1).
However, such the prior art intends to improve the fatigue strength by improving a casting step and can not improve the fatigue strength of a material after a cast iron material was mechanically machined.
PRIOR ART DOCUMENT
Patent Document
Patent Document 1: Japanese Patent Application Non-examined Publication No. 2005-8913
SUMMARY OF THE INVENTION
Problem that the Invention is to Solve
The present invention was proposed in view of problems of above-described prior arts, and intends to provide a method for improving a fatigue strength, which can improve the fatigue strength of a cast iron material, in particular, a spherical graphite cast iron to a value the same as that of a carbon steel that was carburized and hardened.
Means for Solving the Problems
A method for improving a fatigue strength of a cast iron material of the present invention, contains the steps of
Performing a first shot peening treatment with shots having the hardness of 600 Hv or more and a particle size (φ) of 0.5 to 0.8 mm (1 step),
performing a second shot peening treatment with shots having the hardness of 600 Hv or more and a particle size (φ) of 0.1 to 0.3 mm (2 step), and
performing a third shot peening treatment with shots having the hardness of 600 Hv or more and a particle size (φ) of 0.1 mm or less (3 step)
for each on spherical graphite cast iron on which quenching and tempering heat treatment or austempering heat treatment has been performed and tensile strength made to be 1200 MPa or more, the spherical graphite cast containing the following elements in the following mass percentages: C=2.0-4.0%, Si=1.5-4.5%, Mn=2.0% or less, P=0.08% or less, S=0.03% or less, Mg=0.02-0.1%, and Cu=1.8-4.0% Cu.
Upon applying the present invention, it is preferred that, after performing the first to third shot peening treatments, a shot peening treatment is performed with shots composed of tin or molybdenum to perform metal lubrication.
Advantages Effects of Invention
In result of an experiment being carried by the inventor, in a case that the first to third shot peening treatments are performed with respect to a spherical graphite cast iron that contains, by weight ratio, 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, quenching and tempering heat treatment has been performed to the spherical graphite cast iron and that the tensile strength made to be 1200 MPa or more, the fatigue strength of 350 MPa or more can be obtained, which strength is the bending fatigue strength being the same level as that of carburized and hardened steel material.
Also, in result of an experiment being carried by the inventor, in a case that the first to third shot peening treatments are performed with respect to a spherical graphite cast iron that contains, by weight ratio, 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, an austempering heat treatment has been performed to the spherical graphite cast iron and the tensile strength made to be 1200 MPa or more, the fatigue strength of 350 MPa or more can be obtained, which strength is the bending fatigue strength being the same level as that of carburized and hardened steel material.
According to the present invention, a compressive residual stress distribution about 600 MPa can be imparted for a range of 100 μm from a surface by performing the first to third shot peening treatments, generations of fine cracks on a surface of a spherical graphite cast iron and development of the cracks are retarded, and therefore, the fatigue strength is improved.
According to the present invention, by subjecting a predetermined machine process (for example, a gear-cutting process for an automobile transmission gear) to a spherical graphite cast iron, which contains, by weight ratio, 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, quenching and tempering heat treatment or austempering heat treatment has been performed and the tensile strength made to be 1200 MPa or more, and after, by performing the first to third shot peening treatments to the spherical graphite cast iron, the bending fatigue strength being the same level as that of a carburized and hardened steel material can be obtained, without performing a carburizing and hardening treatment.
Further, since it is not necessary to carry out a heat treatment after machine processing, the heat treatment strain can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing showing a procedure of a method for improving a fatigue strength of the present invention.
FIG. 2 is a drawing showing test results of a tensile test of test samples.
FIG. 3 is a depth from a material surface-residual stress line chart, which shows a residual stress distribution when each of the first to third shot peening treatments was conducted.
FIG. 4 is a drawing showing a distribution of compressive residual stresses after the first to third shot peening treatments were performed.
FIG. 5 is a drawing showing a test piece being used in bending fatigue tests.
FIG. 6 is a drawing showing test results of rotating bending fatigue tests in Experimental Example 1.
FIG. 7 is a drawing showing results of Experimental Example 2 as a table.
FIG. 8 is a drawing showing results of Experimental Example 3 as a table.
FIG. 9 is a drawing showing results of Experimental Example 4 as a table.
FIG. 10 is a drawing showing results of Experimental Example 5 as a table.
FIG. 11 is a drawing showing results of Experimental Example 6 as a table.
FIG. 12 is a drawing showing results of Experimental Example 7 as a table.
FIG. 13 is a fatigue strength line chart of a spherical graphite cast iron.
DESCRIPTION OF EMBODIMENTS
Hereinafter, with reference to accompanying drawings, an embodiment of the present invention will be described.
At first, with reference to FIG. 1 , a work procedure in an illustrated embodiment will be described.
In FIG. 1 , a spherical graphite cast iron, which contains 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, by weight ratio, is subjected to quenching and tempering heat treatment or austempering heat treatment so as to make the tensile strength to be 1200 MPa or more (step S 0 ).
Then, a shot peening treatment is performed (conducted) with shots having hardness of 600 Hv or more and a particle size φ of 0.5 to 0.8 mm (step S 1 : a step for performing a first shot peening treatment: first step).
Next, a shot peening treatment is performed with shots having hardness of 600 Hv or more and a particle size φ of 0.1 to 0.3 mm (step S 2 : a step for performing a second shot peening treatment: second step).
Then, a shot peening treatment is performed with shots having hardness of 600 Hv or more and a particle size φ of 0.1 mm or less (step S 3 : a step for performing a third shot peening treatment: third step).
Thereafter, with tin or molybdenum shots having an appropriate hardness and particle size, a shot peening treatment is performed (step S 4 : a step for performing a fourth shot peening treatment: fourth step).
According to the step S 4 , on a surface of a workpiece on which the first to third shot peening treatments were performed, metal lubrication can be performed.
In addition, the step S 4 may be omitted.
According to said step S 4 , an effect is advantageously imparted that a surface being flattened by the third shot peening treatment is further metal lubricated.
Said step S 4 is not an indispensable step and can be omitted in order to reduce steps and necessary time period of a whole process.
From a test sample being performed the first to third shot peening treatments (1 to 3 steps) thereon, a fatigue test sample shown in FIG. 3 was manufactured.
In an illustrated Embodiment, a shape of a test piece which is entirety shown by a character 12 comprises, for example, in a round bar 3 having an outer diameter of 12 mm, a recess 5 being a grooved in a sectional shape of character V and extending around an entire periphery in a circumference direction. At a bottom 5 a of a recess 5 , a diameter of a round bar 3 is 8 mm. Here, a test piece 12 shown in FIGS. 5( a ) and 5( b ) has a shape the same as that of a general test piece.
With such the test piece 13 , a rotating bending fatigue test was performed.
As below-mentioned in Experimental Example 1, the fatigue strength of a spherical graphite cast iron to which the shot peening treatments of steps S 1 to S 3 of FIG. 1 were performed has the bending fatigue strength (for example, about 350 MPa) the same as that of a carburized and hardened steel material.
The inventors have carried out experiments (Experimental Example 1 to Experimental Example 6) such as shown below with a spherical graphite cast iron, which contains 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, by weight ratio.
Experimental Example 1
By performing the quenching and tempering heat treatment to the above-mentioned spherical graphite cast iron, the tensile strength is made to be 1200 MPa or more.
Results of a tensile test of a test sample, in which samples the quenching and tempering heat treatment applies to the spherical graphite cast iron (the quenching and tempering heat treated spherical graphite cast iron), are shown with a characteristic curve FCD in FIG. 2 .
In FIG. 2 , a vertical axis indicates a tensile stress (MPa) and a horizontal axis indicates a tensile strain (ε). Three kinds of test pieces No. 1 to No. 3 all have the maximum tensile stresses of 1200 MPa or more. A characteristic curve FCA, that is shown as a reference, shows tensile stress (MPa)-tensile strain (ε) characteristics in a cast iron and the maximum tensile stress was 272.4 MPa.
Next, with shots having hardness of 600 Hv or more and a particle size (φ) of 0.5 to 0.8 mm, a first shot peening treatment was performed. Results of the first shot peening treatment are shown as a residual stress distribution curve A in FIG. 3 (a residual stress distribution curve after the first shot peening treatment: a characteristic curve having a plot of “□”).
According to a residual stress distribution curve A, until a depth of 150 μm from a test piece surface (0 μm), a residual stress has a nearly even numerical value of −800 (MPa) while slightly increasing.
In FIGS. 3 and 4 , a vertical axis shows a numerical value of the residual stress. Therefore, in FIGS. 3 and 4 , in a case that a numerical value of the compressive residual stress is high, it is shown in a lower part (on a side where a negative absolute value is large).
On a test piece differing to said test piece from which a residual stress distribution curve A in FIG. 3 has been obtained, a second shot peening treatment was performed with shots having a hardness of 600 Hv or more and a shot particle size (φ) of 0.1 to 0.3 mm. Results thereof are shown in FIG. 3 as a residual stress distribution curve B (a residual stress distribution curve after the second shot peening treatment: a characteristic curve having a plot of “O”).
In the residual stress distribution curve B, in an area (region) until a depth of 50 μm from a test piece surface (0 μm), a compressive residual stress rapidly increases, and in an area in a depth of 50 μm or more, a compressive residual stress slowly increases.
On a test piece further differing to said test piece from which a residual stress distribution curve A in FIG. 3 has been obtained or differing to said test piece from which a residual stress distribution curve B in FIG. 3 has been obtained, a third shot peening treatment was performed with shots having a hardness of 600 Hv or more and a shot particle size (φ) of 0.1 mm or less. Results thereof are shown in FIG. 3 as a residual stress distribution curve C (a residual stress distribution curve after the third shot peening treatment: a characteristic curve having a plot of “⋄”).
In a residual stress distribution curve C, in an area until a depth of 25 μm from a test piece surface (0 μm), a compressive residual stress rapidly increases, and in an area deeper from a surface than a depth of 25 μm, a compressive residual stress slowly increases.
A residual stress distribution thereof is shown in FIG. 4 which shows a result in a case that the first to third shot peening treatments have been performed to the same test piece.
In FIG. 4 , a residual stress distribution of a test piece before the first to third shot peening treatments is performed is shown with a residual stress distribution curve G.
On the other hand, a residual stress distribution of a test piece after the first to third shot peening treatments have been performed is shown with a residual stress distribution curve Sa.
As obvious in FIG. 4 , being compared with a residual stress of a test piece before the first to third shot peening treatments, a residual stress distribution of a test piece after the first to third shot peening treatments increases. Here, a gap (difference) between a residual stress distribution curve G and a residual stress distribution curve Sa corresponds to an increment of a compressive residual stress owing to the first to third shot peening treatments.
Refering to FIG. 4 , it can be understood that a test piece on which the first to third shot peening treatments have been performed has an increased compressive residual stress entirely in an area from a surface to 150 μm inside, compared with compressive residual stress of a test piece on which the first to third shot peening treatments have not been performed. In FIG. 4 , a gap (difference) between a residual stress distribution curve G and a residual stress distribution curve Sa corresponds to an increment of compressive residual stress.
A residual stress is such large as 1000 MPa at a surface 0 μm and as about 700 MPa in an area from 25 μm to 100 μm. Also in an area (region) more inside than 100 μm, a test piece on which the first to third shot peening treatments have been performed has an increased compressive residual stress, compared with compressive residual stress of a test piece on which the first to third shot peening treatments have not been performed.
In Experimental Example 1, the first to third shot peening treatments were performed on the same test piece, a fatigue test piece shown in FIGS. 5( a ) and 5( b ) was manufactured from the material (the test piece), and the rotating bending fatigue test (JIS Z 2274) was performed thereon. Results of such the fatigue test are shown in FIG. 6 . In FIG. 6 , a vertical axis indicates (shows) a bending stress (σ: MPa), and a horizontal axis indicates the number of times of repetition (N).
A mark H in FIG. 6 shows a characteristics curve of the bending fatigue strength of a test piece to which the first to third shot peening treatments were performed in Experimental Example 1.
It was found in FIG. 6 that a test piece according to Experimental Example 1 has a bending fatigue strength the same as that of a carburizing and quenching steel (about 350 MPa).
A bending fatigue curve J in FIG. 6 shows a bending fatigue curve of a high tensile cast iron of FCDI 1400 MPa on which a shot peening treatment has not been performed. Said bending fatigue curve J is shown also in FIG. 13 .
In Experimental Example 1, from results shown in FIG. 6 , it was found that the bending fatigue strength being generally the same as that (about 350 MPa) of a carburized and hardened low carbon steel material can be obtained, by applying quenching and tempering heat treatment to the spherical graphite cast iron, which contains 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, by weight ratio, so as to impart the tensile strength of 1200 MPa or more, and then, performing the first to third shot peening treatments thereto.
Further, from a compressive residual stress distribution shown in FIG. 3 , it was found that
when the first shot peening treatment is omitted, a compressive residual stress is decreased in an area deeper by 25 μm or more from a surface decreases, and
when the second shot peening treatment is omitted, a compressive residual stress in an area until 25 μm from a surface is decreases.
Experimental Example 2
In Experimental Example 2, a test material that was obtained by applying said spherical graphite cast iron to an austempering heat treatment to be made a tensile strength to be 1200 MPa or more was used.
With respect to such the test materials, in a manner the same as that of Experimental Example 1, a first shot peening treatment was performed with shots having a hardness of 600 Hv or more and with a shot particle size (φ) of 0.5 to 0.8 mm, to one test material,
a second shot peening treatment was performed with shots having a hardness of 600 Hv or more and with a shot particle size (φ) of 0.1 to 0.3 mm, to the other test material, and
a third shot peening treatment has been performed with shots having a hardness of 600 Hv or more and a shot particle size (φ) of 0.1 mm or less, to the further other test material.
Results of the above-mentioned Experimental Example 2 are the same as that shown in FIG. 3 in Example 1.
Further, with respect to the same test material, the first to third shot peening treatments have been performed and a compressive residual stress distribution in said test piece was examined. Results of said examination were the same as the results of FIG. 4 in Example 1.
With a test material on which the first to third shot peening treatments have been performed, a fatigue test piece the same as that of Example 1 was prepared, and a rotating bending fatigue test was carried out.
Results of such the fatigue test are shown in FIG. 7 . In FIG. 7 , a vertical axis shows a bending stress (σ) and a horizontal axis shows the number of times of repetition (N).
In FIG. 7 , a fatigue curve K shows a bending fatigue strength of a test piece being performed Experimental Example 2.
As obvious from results of Experimental Example 2, it was found that when an austempering treatment is performed with respect to a spherical graphite cast iron that contains, by mass percentage, C=2.0 to 4.0%, Si=1.5 to 4.5%, Mn=2.0% or less, P=0.08% or less, S=0.03% or less, Mg=0.02 to 0.1%, and Cu=1.8 to 4.0% to impart a tensile strength of 1200 MPa or more, and the first to third shot peening treatments are performed, a bending fatigue strength being the same as that (about 350 MPa) of a carburizing and quenching steel material can be obtained.
Experimental Example 3
When a first shot peening treatment is performed with respect to a test piece used in Experimental Example 1 (the spherical graphite cast iron, which contains 2.0 to 4.0% C, 1.5 to 4.5% Si, 2.0% or less Mn, 0.08% or less P, 0.03% or less S, 0.02 to 0.1% Mg, and 1.8 to 4.0% Cu, by weight ratio, and was applied quenching and tempering heat treatment thereto), a fatigue test of bending fatigue strength was performed to test pieces, which is manufactured in a manner the same as that of Experimental Example 1, except that shots having a particle size larger than 0.8 mm (particle size: 0.9 mm, 1.0 mm, and 1.1 mm) were used.
In FIG. 8 , results of the fatigue test when a first shot peening treatment was performed with shots having a particle size of 0.8 mm, 0.9 mm, 1.0 mm or 1.1 mm are shown. In FIG. 8 , “◯” shows that the fatigue strength being the same level as 350 MPa was obtained, and “X” shows that the fatigue strength did not reach about 350 MPa.
Although in a case that a shot particle size is 0.8 mm, the fatigue strength the same as that (about 600 MPa) of a carburized and hardened steel material was obtained (“◯” in FIG. 8 ), in an other case that a shot particle size is 0.9 mm, 1.0 mm or 1.1 mm, the bending fatigue strength was 350 MPa or less (“X” in FIG. 6 ).
From FIG. 8 , it was found that in the first shot peening treatment, a shot particle size should be set to 0.8 mm or less.
When the shot particle size is larger than 0.8 mm in the first shot peening treatment, it is considered that shots are not conveyed by an air flow when shots are blasted off, and therefore, sufficient impacts can not be imparted to the test piece.
Experimental Example 4
In a manner being similar to that of Experimental Example 1, except that shots having a particle size of 0.5 mm or smaller (particle size: 0.5 mm, 0.4 mm, 0.3 mm) were used in a first shot peening treatment, the fatigue test was performed relating to the bending fatigue strength.
In FIG. 9 , “◯” shows that the fatigue strength being the same level as about 350 MPa was obtained, and “X” shows that the fatigue strength did not reach about 350 MPa.
As shown in FIG. 9 , in a case that a shot particle size is 0.5 mm, the fatigue strength being the same level as that (about 350 MPa) of a carburized and hardened steel material could be obtained (“◯” of FIG. 9 ), however, in an another case that a shot particle size is 0.4 mm or 0.3 mm, the bending fatigue strength was 350 MPa or smaller (“X” of FIG. 9 ).
From FIG. 9 , it was found that in the first shot peening treatment, a shot particle size should be set to 0.5 mm or larger.
It is considered in a case that a shot particle size is smaller than 0.5 mm in the first shot peening treatment, although the compressive stress on a surface side of a steel material becomes larger, the compressive stress inside the steel material becomes smaller.
Experimental Example 5
In a manner similar to that of Experimental Example 1, except that shots having a particle size of 0.3 mm or larger (particle size: 0.3 mm, 0.4 mm, 0.5 mm) were used in a second shot peening treatment, the fatigue test was performed relating to the bending fatigue strength.
In FIG. 10 , “◯” shows that the fatigue strength being the same level as about 350 MPa was obtained, and “X” shows that the fatigue strength did not reach about 350 MPa.
As shown in FIG. 10 , in a case that a shot particle size is 0.3 mm, the fatigue strength being the same level as that (about 350 MPa) of a carburized and hardened steel material could be obtained (“◯” of FIG. 8 ), however, in an another case that a particle size is 0.4 mm or 0.5 mm, the bending fatigue strength was 350 MPa or smaller (“X” of FIG. 10 ).
From results of FIG. 10 , it was found that in the second shot peening treatment, a shot particle size should be set to 0.3 mm or smaller.
Although the second shot peening treatment is a treatment for improving the compressive residual stress of the outermost surface (a region where a distance from a surface is 50 μm) of a cast iron test piece, it is assumed that a peak of the compressive residual stress is not generated on the most surface and the fatigue strength was not improved, in a case that a shot particle size is larger than 0.3 mm.
Experimental Example 6
In a manner similar to that of Experimental Example 1, except that shots having a particle size of 0.1 mm or smaller (particle size: 0.1 mm, 0.07 mm, 0.01 mm) were used in a second shot peening treatment, the fatigue test was performed relating to the bending fatigue strength.
In FIG. 11 , “◯” shows that the fatigue strength of about 350 MPa could be obtained, and “X” shows that the fatigue strength did not reach about 350 MPa.
As shown in FIG. 11 , in a case that a shot particle size is 0.1 mm, the fatigue strength being the same level as that (about 350 MPa) of a carburized and hardened steel material could be obtained (“◯” of FIG. 9 ), however, in an another case that a particle size is 0.07 mm or 0.01 mm, the bending fatigue strength was 350 MPa or smaller (“X” of FIG. 11 ).
From FIG. 11 , it was found that in the second shot peening treatment, a shot particle size should be set to 0.1 mm or larger.
It is assumed that when a particle size of shots used in the second shot peening treatment is small, a surface of a cast iron is smoothened merely, the compressive residual stress of the outermost surface of a steel material was not generated, and the fatigue strength could not be improved.
Experimental Example 7
Gears (gears on which the first to third shot peening treatments were performed) Z being manufactured with a test material of Experimental Example 1 and gears Y being manufactured with a test material to which the third shot peening treatment was not applied, were prepared.
As to gears (gears on which the first to third shot peening treatments were performed) Z being manufactured with a test material of Experimental Example 1, the sliding properties of an engagement surface were good.
By contrast, as to gears Y being manufactured with a test material to which the third shot peening treatment was not applied, the sliding properties of an engagement surface showed abnormality.
In more detail, in FIG. 12 , the gears Z were good in touch and sliding properties between engagement gear surfaces and were cleared the predetermined endurance test (shown by “◯” in FIG. 12 ).
By contrast, the gears Y were not good in touch and sliding properties between engagement gear surfaces, generated fine cracks on a gear surface, and could not clear the predetermined endurance test (shown by “X” in FIG. 12 ).
From FIG. 12 , it was found that the third shot peening treatment should not be omitted.
According to the third shot peening treatment, a surface being roughened by the first and second shot peening treatments is smoothened, and an irregularity of a gear surface becomes smaller; accordingly, in fine irregularity, oil stays therein to exert a lubrication operation.
It is assumed that the test material, to which the third shot peening was not applied, could not exert such the lubrication operation and that sliding abnormality was generated on an engagement surface.
Illustrated embodiments are merely examples and do not intend to limit a technical range of the present invention.
For example, illustrated embodiments can be applied to a cum of a valve operating system, con rod, and various kinds of pumps for supplying a gear high pressure oil.
EXPLANATION OF REFERENCE NUMERALS
5 ROUND BAR PORTION
6 R CURVE
7 SMALL RADIUS PORTION
13 BENDING TEST PIECE
Y GEAR PREPARED WITH MATERIAL OBTAINED BY OMITTING THIRD STEP
Z GEAR PREPARED WITH MATERIAL AFTER EXPERIMENT 1
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The purpose of the present invention is to provide a method for improving fatigue strength that is capable of improving the fatigue strength of cast iron, specifically spherical graphite cast iron, to the same level as that of carbon steel subjected 10 carburizing and quenching. To this end, this method contains a step for performing first, second and third shot peenings using shot of a prescribed diameter for each on spherical graphite cast iron on which a quenching and tempering heat treatment or austempering heat treatment has been performed and tensile strength made to be 1200 MPa or more, the spherical graphite cast iron containing the following elements in the following mass percentages: C=2.0-4.0%, Si=1.5-4.5%, Mn=2.0% or less, P=O.08% or less, 8=0.03% or less, Mg=0.02-0.1%, and Cu=1.8-4.0%.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is in the field of wide flat belts or webs that run over pulleys. The pulley is the element in the system that both drives the belt and causes it to run in the desired direction, and such a pulley is the subject of the invention.
Wide, flat belts find many industrial applications throughout industry, usually for the transfer of materials. In most common usage the belt is endless and is generally trained over two or more pulleys which lead it in the desired loop path. For satisfactory operation it is required that the belt remain running on the pulleys without walking off in either the left or right direction to the point where it will become damaged by contact with stationary frame members. Unfortunately, due to practical considerations in the manufacture of both belts and pulleys, dimensional inaccuracies are almost always present. Such imperfections that may go unnoticed in an open ended system become important when the error is repeated endlessly in the same direction, as in a cycling system of which the pulley/belt is an example.
Thus in any real system the pulleys will require periodic adjustment in order to prevent offrunning of the belt, with subsequent belt damage. Contact with frame members will not only damage the belt but may overload the drive system elements to the point of failure.
In spite of the difficulty in using wide and short belts they are indispensable in industry finding wide application in such diverse uses as belt sanders, material conveyors, and treadmills. Because of these commercial uses many devices have been introduced to assist in assuring that these wide belts run satisfactorily.
2. Prior Art
One way to prevent a wide belt from walking completely off one side of a pulley is to add an edge flange to the pulley. As long as the flange is high enough that the running belt cannot climb over it, then this means is effective in keeping the belt on the pulley. However the belt will be gradually damaged on the rubbing edge due to high force contact with the flange.
`V` belts, which run in deep grooves, track without problems, therefore a common practice is to attach a `V` belt to the pulley side of a wide flat belt running in a mating `V` groove in the pulley. This means takes advantage of the fact that the `V` belt is locked firmly in its groove. A common result however, is that the sideways movement of the wide flat belt is so powerful that it drags hard against the `V` belt either breaking the bond, or fracturing the flat belt in the process. When the belt is long enough rollers are sometimes used on the lower slack side to guide the belt into the desired path by bearing against the belt edges. Again, damage to the belt can and does result.
Belt training pulleys are often made with raised helical lands on the surface which appear to act on the belt by collapsing toward the pulley centerline under the belt load, thereby carrying the belt in the flexing direction toward the running centerline. To permit the device to work in both directions one half of the pulley has lands helical in one direction and the other half in the opposite. Thus the centering force is expected to be higher on the side of runoff, thereby urging the belt back toward the centerline. However the force is weak when compared to runoff forces and rarely assures proper tracking.
In cases where the belt is long when compared to its width satisfactory belt tracking is often accomplished by crowning one or both of the end pulleys upon which the belt runs. Crowning presents an angled support surface to the belt as it wanders off either to the right or left. The length and narrowness of the belt allow it to turn and meet the angled pulley surface. When this occurs the belt experiences a drag force which moves the belt back toward the running centerline of the pulley. In the case where the belt is wide when compared to its length, such turning across the width does not occur and the belt will continue to run toward one side or the other, as dictated by the belt dimensions and pulley orientation.
OBJECTS OF INVENTION
1. The first object of the invention is to provide a pulley that will exert a sideways force on a belt running over the pulley to cause it to move axially of the pulley in either a left or right hand direction as desired.
2. A second object is to incorporate a means in the pulley structure to respond to an undesired offcentered position of the belt upon the pulley and change the pulley orientation to cause axial movement of the belt away from the pulley edges and toward the pulley centerline.
3. A third object is to provide a belt steering means that will move a belt in a desired direction by providing force across its entire width rather than bearing against the edge of the belt which will cause damage to the belt because of the localized contact.
4. A fourth object is to provide a belt steering means that fits readily within the web, the pulley, and its mounting structure without protruding operating elements.
5. A fifth object is to provide a belt steering roller that in one mode can operate automatically in response to a misposition of the belt without external operating means.
6. A sixth object is to provide a belt steering means that can function to train the running web toward the pulley centerline when commanded by a signal from a position sensor that perceives the belt edge.
7. A seventh object is to utilize the unique construction of the pully of the invention to provide a means that can move a running belt axially of the training pully in both left and right directions simultaneously, thereby stretching the web incrementally across its width and with the degree of stretch under outside rota motion control.
SUMMARY
The present invention presents a method of manipulating the direction of a be as it runs over the partial perpheral surface of a guiding pully.
In its form the invention is a pully comprised of a series of similar diameter and similar thickness annular discs grouped together in a stacked array to make up the cylindrical body of a roller or pully around which a traveling belt is looped. Each of the annular discs is provided with its own axis of rotation w is different from the general rotational axis of the assembled pully. A special control means is provided so that if the belt has moved away from the centerline and toward an edge of the pully the array of discs can be reangled so as to urge the belt back toward the centerline of the system. The belt is thereby prevented from continuing to run off the pulley edge and perhaps suffering damage from contact with stationary supports.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the invention shown in contact with a driver pulley and looped belt and angle control means.
FIG. 2 is an illustration of the pully showing the multi-axis multi-disc construction, each disc having anti-friction bearings, with friction actuated directional control means.
FIG. 3 is an end view of the pulley in FIG. 2 from the left side.
FIG. 4 is an end view of the pulley in FIG. 2 taken from the right side.
FIG.5 is the same annular pulley with each disc of the pully running about its individual axis, this time using bearing bushings, and having latching control means.
FIG. 6 is an exploded view of the latch mechanism of FIG. 5.
FIG. 7 is a left hand end view of the pulley of FIG. 5.
FIG. 8 is a right hand end view of the pulley in FIG. 5.
FIG. 9 illustrates the multi-axis pulley equipped with a belt sensing means coupled to a tracking control means, also showing discs with interlocking teeth.
FIGS. 9a and 9b show the relative locations of a signaling member and a pair of sensors.
FIG. 10 is a plan view of a controlled position multi-axis pulley with each disc running in slightly different directions for use in the special situation of belt stretching to eliminate running creases, disc angles being controlled as before.
FIG 11 is an end view of the pulley in FIG. 12 showing a motorized means of adjusting the disc angles which control the degree of stretch.
DESCRIPTION OF THE INVENTION
Structure
A combination of two pulleys and a single looped belt as shown in FIG. 1, comprise a simple running belt system. The head pulley 1 may be supported on internal bearings, or on a rotating shaft. If the head is the driver pulley then it may be internally motorized or may be connected to an external power source through a drive chain. The belt 2, the working member of the group, runs around both pulleys in a looped path that is defined by the pulleys. The belt may be used to transport materials along its length, or in the proportions shown it may be used as a carrier of abrasives for use in sanding. A second pulley 3, which is the subject of this invention, completes the system. As shown, the head pulley 1, is supported in an external bearing. The tail or steering pulley 3, is supported through a selectively rotated shaft in an outer frame member, with each of its annular individually rotating discs 3, being supported by control shaft 5, and each running on individual bearings. The controlled angle multi-disc construction of the pulley which may be used to control the belt path is the subject matter of the present invention.
As defined by this invention, pulley 3 is made up of many similarly shaped annular discs with parallel sides, all being stacked together in an adjacent array to form a cylindrical pulley of the width required to support the belt. Each disc in the array is supported on its own angled carrier, the group of carriers being rotatable to govern the direction of the discs with respect to the running belt.
Friction directional control means
Now referring to FIG. 2, the sketch shows an end-on view with the belt approaching at the bottom and receding at the top. The belt 2 is shown cut through at the targent point of contact with the pulley to reveal the pulley structure. The multiple annular discs which make up the pulley structure are also shown in a section view. All of the discs in this embodiment are positioned at the same angle with respect to an overall pulley axis perpendicular to the direction of belt travel.
For structural reasons each disc 6, is pressed onto a ball type bearing 7. In turn, each bearing is pressed onto a carrier 8 which has a square or otherwise keyed hole broached through at an angle to the bearing bore. The faces of the carriers are ground perpendicular to the bore. All carriers with bearings and annular discs in place are pressed onto a mating square or keyed support member 9, in suffifient number to form the complete web carrying pulley. Note that the bearings must be narrower than the carrier width to prevent interference with neighboring bearings. At each end of the assembled discs, drag-plates, 10 and 11, are mounted on the same square or keyed shaft 9, each located axially on the throughgoing support member by a pin 12.
In FIG. 3 drag-plate 10 has a raised land 65 on its periphery. Drag-plate 11, FIG. 4, also has a raised land 66 on its perphery. The land are just high enough to be contacted by the belt without protruding excessively in a manner which might damage the belt. The land on dragplate 10 is 180 degrees displaced around the connector shaft from the land on dragplate 11 and each land occupies approximately one quarter of the circumference. Each drag-plate is shaped to lie snugly against the side of the adjacent disc carrier 8, while allowing the disc 6 to rotate freely. Contrast between the adjacent carries determines the axial spacing of all elements.
The support member 9 has cylindrical extensions 13 at each end. Each extension is carried in a bearing 14, which is in turn carried in a suitable frame member such as 15.
To locate the drag plate and its assembled carries in a generally correct position with respect to the running belt, a detent device such as 42, have a locating ball or roller 43, is used. The ball cooperates with a cavity 44 in the drag plate. Instead of a detent, a brake and pad device could be used since an exact position is not required for satisfactory operation. Use of an adjusting screw 30 permits a level of holding force to be applied that will resist the frictional drag of the bearings 7, yet will break free when the belt wraps over either of the drag plate lands 65 or 66.
Operation
The pulley as heretofore described is used in the context of a belt and pulley system as illustrated in FIG. 1. FIG. 2 shows a conventional arrangement where the belt arrives at the pully at its lower surface at the point shown by the head-on arrow. The belt moves onto the pulley surface which is primarily moving in the belt direction and at belt speed. Because of their angled orientation the surface of each of the discs comprising the pulley moves laterally through a small dimension over the 180 degrees during which the belt is in contact. Thus the belt is laterally distorted by the discs so that it leaves the pulley at the point shown by the tail-on arrow slightly displaced laterally from its incoming position. The angle has been greatly exaggerated to clarify the function.
After many revolutions of the pulleys the belt will creep far enough to the side, in the direction set by the angled carriers, so that it will contact the raised surface 65 of the dragplate 10. The dragplate and connected shaft are free to rotate in the bearings 14. As the dragplate becomes driven by the belt it rotates all carriers 8 together through the keying action of the pin 12 and the square support member 9. All discs follow their carriers and move such that the angle of each disc from the true perpendicular on that portion of the periphery contacted by the belt will diminish and the belt will not be carried as positively toward the side as in the previous condition. As the belt continues to rotate the dragplate its raised surface passes out from under the impelling belt. When the shaft reaches this point, all carriers will be turned through 180 degrees and therefore all discs will be inclined in the opposite direction and thus the belt will be slowly carried to the opposite side of the pulley where the raised land 66 of dragplate 11 is now in position to be contacted by the belt when it arrives. While exact positioning of the assembly is not necessary the dragplate should turn through approximately 180 degrees for best operation. The brake or detent system is sufficient to overcome bearing friction and stops the dragplate after this angle of motion.
Latching Directional Means--Structure
In some cases the belt is made of a material, such as steel, that cannot accommodate the slight stretch required to flex over the raised surface of the endplate as just described. In this case the raised actuating surface can be depressed by the overriding belt in order to obviate the need for stretch. FIGS. 5, 6, 7, and 8, illustrate such a construction. Each of the discs 16 is carried with a press fit on a bearing made from any long-wearing material such as bronze or plastic 17. As in the previous construction the bearing 17 is a slip fit on the carrier 8 through which a center square hole has been broached. The carrier determines the angle from the perpendicular at which the disc is caused to run. All carriers and discs are assembled in close proximity onto a square sectioned support member 19. The last carrier may be made integral with, or otherwise connected to, a dragplate 23 carrying an operating member. On either end of the through support member are mounted latch members 18. Each latch member 18 carries a latch plate 20 which consists of a smooth almost cylindrical surface depressed in one area to form a latch 21. An integral extension of latch member 18 is shaped into a second square extention 26, which is mounted into a matching square hole in the support structure 22. The relationship of support member 19, dragplate 23, carriers 8, and latch member 18 are shown in FIG. 6. On the opposite end of the support member, latch member 18 is made in the reverse image. Corresponding latches on either end are spaced 180 degrees apart around support member 19. Dragplates 23, FIGS. 7 and 8, which are carried at each end of the cylindrical assembled pulley structure, each contain a sliding release plate 24 that surrounds the almost circular surface 20 of the latch member 18, and carries a mating pawl 68 which cooperates with the latch 21. The end of the release plate 24 opposite the pawl 68 is raised slightly above the pulley surface in a position to be intercepted by the belt as it moves too far toward the pulley edge. The release plate travel is defined by the surface 20 and by a spring 25 which impels the release plate into contact with the latch member, engaging the cooperating pawl and latch.
Operation
As the multi-axis steering pulley is driven by the belt, the frictional drag exhibited by the bearings 17 rotates the carrier, through support member 19, and dragplates 23 until one of the pawls 68 in one of the dragplates meets its mating latch 21 in latch member 18. The dragplate 23, support member 19 and all carriers then stop rotating and the belt bearing discs 16 rotate normally about their individual bearings 17.
With a particular latch engaged, the discs are consequently inclined at an angle to cause the belt to move toward that engaged side. As it runs about the pulley system the belt will slowly migrate toward that side which has the engaged latch. After the belt has moved far enough to move over the top of the endplate 23 the sliding release plate 24 becomes depressed by the belt releasing the latch from the pawl.
With the latch released the frictional drag of the bearings then rotates the entire pulley structure within the latch members 18 until after 180 degrees of travel the latch and pawl on the opposite side engage and stops dragplate, support member, and carrier rotation. In this new position the belt bearing discs are inclined opposite to their previous direction which, in consequence, causes the belt to move across the pulley in the opposite direction. Movement is always toward the engaged latch. Thus, as the belt is running, it moves cyclically from side to side on the multi-disc pulley with a frequency of cycling governed by the angle chosen for the carriers. When the belt is of low quality, with poorly controlled dimensions, the carrier angles will need to be relatively large and the belt will cycle rapidly. When the belt is of good quality with more carefully controlled dimensions then the angle may be small and the belt will cycle more slowly.
Remote control system
The previous paragraphs have discussed constructions of the multi-disc pulley which are self-controling. However it is also likely that a user might choose to operate a system wherein the lateral direction of travel of the belt is under remote control. FIG. 9 illustrates a typical arrangement that might be chosen from among the many schemes available for the purpose. The belt and pulley system is similar to that of previous embodiments with a driven head pulley 1, a belt 2, and a multi-axis tail pulley 3. An additional difference in this case is that for illustrative purposes the driving head pulley has been combined with the guidance pulley--a combination which will be discussed in a following paragraph.
Drive is from an outside drive motor 39 receiving power from a mains supply and transferring continuous rotary motion through a belt and sheave arrangement 38. A simple photocell 28 is used to signal the presence or absence of the belt at a given position. The photocell signal is received by a control system 29 also powered from a mains supply. The controller drives a positioning motor 40 whenever a change in the direction of lateral progression of the belt is required. The positioning motor 40 is coupled to the multi-axis pulley through a belt and sheave drive system 41. Two proximity sensors 32 and 34 FIGS. 9a and 9b, are located on the frame at 180 degree intervals about the multi-disc pulley endplate 71. A raised ring segment 33 is mounted on the endplate 71, to cause operation of the sensors. In cooperation with the photocell these sensors start or stop motion of the positioning drive 40 as the location of a gap in the ring segment 33 on the pulley endplate is sensed. Location of the gap in ring segment 33 opposite either sensor 32 or 34, signals to the controller the direction in which the annular discs 6 are angled.
In operation the multi-axis pulley will be in some position with the belt running about the path defining pulleys 1 and 2, with drive from motor 39 being delivered through drive train 38. The controller will seek the belt position as signaled by sensor 28. Either the belt sensor will find that the belt is within its perview or it will not. If the belt is present then the controller will initiate rotation of the multi-axis pulley together with its endplate 71, and with it all the disc carriers 8 to bring the gap in ring segment 33 to the position where all axes are angled appropriately to move the belt axially to uncover the sensor 28. When either sensor 32 or sensor 34 finds the gap in ring segment 33, the motor 40 is turned off and rotation of the carriers stops. In the new disc position as defined by the carriers, the discs will carry the belt laterally away from the belt sensor position. When the belt has moved far enough so that sensor 28 finds that the belt is not present, then motor 40 is started and rotation of the pulley core through 180 degrees is repeated. As before when the gap in ring segment 33 is located by sensors 32 or 34, rotation is stopped. The opposite direction of the discs will now carry the belt back to its original position. The system cycles periodically at a frequency depending on the angular inclination chosen for the disc array. A manual override may be provided to ensure that cycling is appropriately phased.
Many commercial controls will accomplish this relatively simple task, and are not part of this invention.
Use as a driven pulley
In some circumstances it may be required that either the head or the tail pulley combine the functions of being both the drive and the tracking pulley. Such a requirement is anticipated by the arrangement of FIG. 9. Each of the discs 6 is furnished with teeth 35 cut along radial lines which cooperate with similar teeth 36 in its neighbor disc. Sufficient clearance must exist between teeth to permit the angled discs to lie parallel to each other. The teeth will be in contact on the sides of the angled discs only, and spaced apart on the top and bottom of the discs where the belt makes its tangential contact. The endplate on one side 37 is also furnished with similarly cut cooperating teeth. Since the annular discs 6 are at a slight angle with respect to the support member 9, and since the face of drive plate 37 is exactly perpendicular to support member 9, full tooth engagement between the outer of the discs 6 and the end plate 37 will occur at only one point on the disc perimeters. The end plate 37 is coupled through a drive system 38 to a drive motor 39. When motor 39 turns, all discs rotate in unison, generally about the system centerline, but specifically about axes as determined by the bearing carriers 8. The angular position of the multi-discs, whether to the left or the right, is determined by a positioning motor 40 with a control system as previously described. The angular location of the contact point between end plate 37 and first carrier disc 6, will vary depending on the orientation chosen for support member 9.
Note that the interlocking teeth also serve to prevent belt fibers from pulling down between discs and tend to make the pulley surface continuous.
Multi-direction multi-axis discs
FIG. 10 illustrates a variation in the manner of construction of the multi-axis pulley in which the discs rotate about axes that are not only not parallel to the aggregate pulley axis, but are also not parallel to each other.
Each disc 54 is supported on its individual carrier 55 by means of a low friction bearing, as in previous examples of the multi-axis pulley. In turn each individual carrier is mounted on a square section or otherwise keyed cross-member 58. This cross-member shaft 58 is supported in a sleeve 67 which has a square inner hole to engage the crossmember and a circular outer surface to run against the bearing 59 in a rotatable manner. Each of the internal carriers is angled somewhat differently from its neighbor. Thus each of the discs will be rotating in a slightly different direction from that of its neighbors.
An application for this version of the pulley lies in the control of webs which need to be stretched in a crosswise manner, as referred to the web direction, to a variable degree. In this case the center disc 54 will have its particular rotating axis perpendicular to the web travel direction. The neighbor discs on either side 56, and 57, will have their respective axes angled one to the right and one to the left, each by a small degree. Other discs laying yet further from the center disc will have axes that are progressively slightly more angled. In this manner the full width of the web is placed in tension. By means of this cross web tension, creases may be ironed out of the web, as in running newsprint. In another use the web may be stretched to a thinner thickness dimension as in the case of continuously stretching a deformable plastic web material.
Referring to FIG. 11, it will be seen that in this application the web 58 is not expected to wrap around the pulley to a significant degree-probably not more than 60 degrees. Because of this narrow zone of contact it is possible to modify the individual angles through which each of the discs contacts the web by rotating the core shaft 58. In this way the degree to which the web is laterally stretched may be modified by rotating the assembly of discs. Thus, referring to FIG. 10, the square or keyed center crossmember 58 is passed through one of the wall support bearings 59 to a drive gear 60. This gear may be driven by a meshing spiral gear 61 attached to the shaft of a reversible motor 62. Chain or belt drives, or even air driven rack and gear arrangements, are also available to accomplish the same result. In use the operator may observe the web condition and drive the motor in one direction through a control switch 63 to increase the apparent stretch in the web, or drive the motor in a reverse direction through switch 64 in order to decrease the degree of apparent stretch. With a photoelectric scanner to monitor the web width the action can be automatic and capable of fast response to accommodate high web travel speeds.
CONCLUSION
It will be evident from a reading of the preceding specification that a means of constructing a web guiding pulley has been presented that achieves the result of tracking a belt in the desired path without allowing contact with any stationary supporting structure, which action can result in the eventual destruction of the belt itself. This is accomplished without causing unequal stress to be produced across the width, which can also result in belt failure. The combination of independently running stacked discs each mounted on a rotatable angled core piece, to reverse the tracking direction, has been shown to be amenable to several types of control means, some self-contained, some remote.
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A cylindrical pulley over which a belt or web is looped is composed of a series of flat, annular discs, each of which rotates about its own individual axis, all discs closely adjacent to its neighbors so that the aggregate of discs forms the cylindrical pulley. All rotating disc axes are parallel and all are inclined at a chosen angle to the aggregate pulley axis creating a belt contact surface that moves laterally as well as peripherally. All discs revolve about bearing carriers that are rotated together in outboard bearings to change the orientation of the angled discs with respect to the traveling belt. Thus a belt wrapped about the pulley can be made to move in a direction perpendicular to its travel direction at a rate defined by the degree to which the individual discs deviate from the aggregate pulley axis. More importantly the belt can be made to reverse its direction of lateral travel by opposite positioning of the disc carrier group for which purpose several operating means are shown.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the preparation of silane, and, more especially, to the preparation of silane by the hydrogenation of chlorosilanes in a bath of molten salts.
2. Description of the Prior Art
The preparation of silane, SiH 4 , by reacting chlorosilanes, SiH 4-x Cl x , with lithium hydride is known to this art. This reaction can be carried out in a bath of molten salts, consisting, in particular, of a eutectic mixture of lithium chloride and potassium chloride, which melts at about 360° C. The reaction can be represented as follows:
4LiH+SiCl.sub.4 →SiH.sub.4 +4LiCl.
The silane (SiH 4 ) produced is gaseous and it is removed continuously. The lithium chloride thus formed enriches the bath, and such bath can be diverted to a zone of electrolysis zone into which hydrogen is introduced to re-form lithium hydride such that the aforesaid reaction scheme can continue to proceed.
Practically, however, the noted process has a significant disadvantage.
Indeed, the reaction of chlorosilanes with lithium hydride is highly exothermic, with the result that the silane formed partially decomposes in the bath of molten salts, according to the reaction:
SiH.sub.4 →Si+2H.sub.2
This reaction becomes substantial at about 400°-450° C.
Consequently, the yields of SiH 4 are never quantitative and range from 40 to 80% at most.
SUMMARY OF THE INVENTION
Accordingly, a major object of the present invention is the provision of an improved process for the preparation of silane by hydrogenation of chlorosilanes in a bath of molten salts, which process is characterized by marked reduction of the aforesaid competing silane cracking reaction and which enables the essentially quantitative production of silane.
Briefly, it has now surprisingly and unexpectedly been determined that the utilization of certain, specific baths of certain molten salts minimizes to a marked extent the aforenoted objectionable silane cracking reaction.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE of Drawing is a graph plotting the yields of silane (ordinate) as a function of the temperature of the bath of molten salts (abscissa), for three different baths.
DETAILED DESCRIPTION OF THE INVENTION
More particularly according to this invention, featured is the preparation of silane by hydrogenation of chlorosilanes in a bath of molten salts, with such bath necessarily comprising a ternary mixture of lithium chloride and two other chlorides of either two alkaline earth metals, or of one alkaline earth metal and one alkali metal, respectively, or of two alkali metals, and said ternary mixture having a melting point not in excess of about 400° C.
According to a preferred embodiment of the invention, potassium chloride and barium chloride are employed in the bath of salts as the "other" two chlorides referred to above.
According to another preferred embodiment of the invention, potassium chloride and calcium chloride are employed in the bath of salts as the other two chlorides referred to above.
The use of the ternary mixtures according to the invention as the baths of molten salts is notably advantageous because it appears that the cracking of the silane only takes place at a considerably higher temperature, on the order of about one hundred degrees higher, than that at which it takes place with the conventional binary mixture LiCl/KCl, namely, in this case, at about 400° C.-450° C. as above shown. It has therefore been found that the mixtures according to the invention dramatically increase the stability of SiH 4 .
Moreover, the use of the baths of salts consistent with this invention results in a certain economic advantage because the lithium chloride, which is an expensive product, is used in smaller amounts than in the case of the conventional binary mixture, LiCl/KCl.
Other characteristics and advantages of the invention will become more apparent from the description which follows, in reference to the attached FIGURE of Drawing, in which:
the single graph FIGURE corresponds to three curves plotting the yield of SiH 4 (on the ordinate) as a function of the temperature θ (on the abscissa) of the mixture of molten salts, for three different baths.
The baths according to the invention necessarily all contain lithium chloride. The other constituents will be selected essentially according to the temperature which must be attained in order to maintain the mixture in molten state, in particular according to the eutectic point which this mixture can have. This temperature must not be above that at which the cracking of the silane is likely to take place, namely, must not be above about 400° C.
Furthermore, in practice, it is preferred to carry out the reaction at a temperature which is about 50° to 100° C. above the temperature required to maintain the mixture in the molten state, such as to provide a mixture of good fluidity and to improved the transfer of materials.
Thus, the mixtures which preferably are selected are those which, taking account of the operating condition mentioned above, have a melting point which is about 50° to 100° C. below the above-mentioned silane cracking temperature, i.e., a melting point of 300° C. to 350° C.
The following are particularly representative of suitable ternary mixtures within the scope of the invention, other than those already specified above: LiCl/KCl/NaCl; LiCl/KCl/RbCl; LiCl/KCl/SrCl 2 ; LiCl/KCl/MgCl 2 ; LiCl/BaCl 2 /CaCl 2 ; LiCl/CsCl/SrCl 2 .
The reaction is preferably carried out with eutectic mixtures or mixtures which are approximately eutectic. However, it can indeed be carried out with mixtures which vary further from the eutectic, insofar as the melting point of the bath remains below about 400° C.
In order to further illustrate the present invention and the advantages thereof, the following specific examples are given, it being understood that same are intended only as illustrative and in nowise limitative.
EXAMPLE 1
A gaseous mixture containing 6% of SiCl 4 in hydrogen was introduced into a stainless steel reactor containing the molten eutectic mixture CaCl 2 /KCl/LiCl (8/42/50 mol %) melting at about 335° C., to which lithium hydride had been added (about 1 mol/kg). The residence time of the gas in the molten mixture was on the order of 1 second.
The peak of the SiH 4 formed was determined by infrared analysis, at 2,100 cm -1 , of the gaseous mixture exiting the reactor, as a function of the temperature of the bath of molten salts.
The results are plotted as curve 1 of the FIGURE of Drawing. It will be seen that the cracking of SiH 4 only occurs at about 480° C. and that, up to this temperature, the yield of silane is virtually equal to 100%.
EXAMPLE 2
The eutectic mixture BaCl 2 /KCl/LiCl (6/40/54 mol %) melting at 320° C. was employed. The operating conditions and conditions of analysis were the same as in the previous example. The results are plotted as curve 2 of the FIGURE of Drawing. It will be seen that the cracking of SiH 4 only occurs at about 500° C. and that, up to this temperature, the yield of silane is virtually equal to 100%.
COMPARATIVE EXAMPLE
A eutectic binary mixture LiCl/KCl (58.8/41.2 mol %) was employed under the same conditions as in the previous examples. The results are plotted as curve 3 of the FIGURE of Drawing. It will be seen that, above 400° C., the yield of SiH 4 is considerably less than 100%.
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims.
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Silane, a useful intermediate in the production of silicon, is facilely quantitatively prepared by hydrogenating chlorosilanes in a bath of molten salts, said molten bath comprising a ternary mixture of lithium chloride and two other metal chlorides, such two other metal chlorides being either two different alkaline earth metal chlorides, or one alkaline earth metal chloride and one alkali metal chloride, or two different alkali metal chlorides, and said ternary mixture having a melting point not in excess of about 400° C.
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BACKGROUND
Several individual filters as well as several individual chip detectors for use in hydraulic systems, especially in those carrying engine lubricating oils are known in this art. Whereas each of those respective units performs its function commensurate with its specifications, it requires one unit of each kind to effect a concurrent chip detection and filtering operation. This obvious disadvantage results further in the following undesirable characteristics:
(a) Two basic installation procedures are required instead of only one for the combined unit;
(b) Two generic component parts have to be inventoried instead of one;
Contrariwise, units are known which contain both a chip detector and a filter element within one envelope, thereby reducing the parts inventory and both the installation and removal operations, and precluding a failure of installing, or replacing, one of the two required elements.
Devices of the foregoing variety, although performing adequately within their parameters, present, however, the following disadvantages over the subject improvement:
(a) The chip detecting means are usually inside of the filtering means or in another close physical and operational affinity with the latter resulting in possible ill-effects to each other should one of the two elements be filled to capacity with foreign particles, or fail for another reason.
(b) The restoring of the device after a failure requires the negotiation of both the filter and the chip detector, even though only one of the two component parts may have suffered damage.
Teachings of prior art exhibiting one or more of respective aforementioned characteristics include, but may not be limited to, the following, believed to be typical examples:
______________________________________Botstiber 3,186,549 June 1, 1965Botstiber 3,317,042 May 2, 1967Botstiber, et al. 3,325,009 June 13, 1967______________________________________
Each of the referenced art allows for the entering of, in those cases, a lubricant into both a chamber formed by each said unit and, not necessarily in this order, the space enveloped by a filtering screen inside of which the chip-detector unit is positioned. This arrangement requires the complete, often cumbersome, disassembly of each entire device for the inspection, servicing and replacement of component parts. It does not allow for ready access to either or both these parts, causing possible premature, unnecessary servicing and operational outages.
SUMMARY OF INVENTION
The subject invention relates to the joint operation among a chip detector and a standard filter element within one envelope. The advantages of this design approach include the ability of automatically providing chip detection in a full-flow configuration within a standardized filter housing environment. This obviates the need for additional hardware to be mounted on the customer's/user's engine to provide this joint function. Further, the now built-in ability to collect ferromagnetic debris reduces the tendency of the filter to clog in operation or between scheduled inspection intervals.
The invention further includes the following features as shown and described herein:
(a) A standard filter element for placing into a housing which includes an automatic by-pass and/or pop button type by-pass indication;
(b) A concentrically arranged set of at least two axially spaced annular, permanent and preferably ceramic magnets forming a lateral chip retention gap along their peripheries which equal the periphery dimension of the filter assembly at its oil-flow entrance end;
(c) A means utilizing the metallic filter element sleeve as one conductor and the outer housing as another conductor to establish an electric circuit from the chip retention and detection gap to the filter installation mounting surface where a connector is provided for the external connection of the chip detector gap to an indicating or alarm system.
It should be noted that in place of the aforementioned permanent ceramic magnets ferrous and electromagnets may be used, respectively. Further, auxiliary functions such as that covered by the trade name "Zapper" can be incorporated, if required. Also various other supplemental accessories used in this art may be included in the subject configuration to attain an even more universally acting failure prevention device, so long as the believed to be unique feature of a single-structure chip detection and filter unit is maintained.
Moreover, the novel axial arrangement of the chip detector unit to the filter element results in a compact joint design allowing for the replacement of present filters with chip detector equipped filters occupying essentially the same total volume.
Further advantages of the subject improvement per se and over prior art will become more apparent from the following description and the accompanying drawing.
In the drawing, forming a part of this application:
FIG. 1 is an exploded view in front elevation and partly in cross-section of the subject filter and chip detector arrangement;
FIG. 2 is a top view of the magnetic chip detector assembly;
FIG. 3 is a cross-section in the plane III--III through a typical permanent-magnet type chip detector unit as installed at the oil flow entrance of the filter illustrated in the respective detail and installation fragments.
DETAILED DESCRIPTION
Referring now to the drawing, wherein like reference numerals designate like or corresponding parts and, more particularly, to FIG. 1, the joint chip detector-filter arrangement 10 consists of the, in this case, electrically grounded, partly cylindrical housing 12, the filter element 14, the, in this case, permanent-magnet type chip detector 16 and the coupling nut 18 securing the entire assembly. The housing 12 is equipped with an automatic bypass and/or a so-called pop button type by-pass indicator 22, provided at the lower extension 24 of the housing 12. An electric connector 26 is mounted at another location of the grounded housing bottom. A cylindrical stem 28 having a thread 30 formed at its top end and various offset shoulders and threads formed at its bottom end (not shown) is positioned axially within the cylindrical portion of the housing 12. Said cylindrical stem 28 may be electrically insulated from said grounded housing 12 through the application of bushings made from electrically insulating materials in a manner well known in this art and fastened together and to said housing 12 with traditional hardware (not shown). In this example, the electric connector has two terminal pins, one of which is connected to the grounded housing 12, the other to, say, said cylindrical stem 28. Obviously, other electric connection choices are available without affecting this description or the described functions.
The filter element 14 is positioned concentrically with said cylindrical stem 28, and lodged within the upwardly open, cylindrical cavity 32 of the housing 12. Preformed seals 34 are provided at mating filter terminations.
The filter element 14 consists of a cylindrical metal cage 36, serving as the structural frame, having passage holes 38 formed therein and an annular channel 40 formed radially at each of its two ends, within which a cylindrical filter screen 41 of any required type and fineness is positioned.
The chip detector 16, constituting the salient component of the assembly by virtue of its novel form and function, is composed of a cylindrical permanent magnet 42 (FIG. 3), of, in this case, the ferrous or the ceramic type, a washer 44 of an electrically nonconductive material positioned at each annular face of said magnet 42, another, substantially cylindrical member 46 of an electrically nonconductive material having a "T"-shaped cross section placed around the lateral outside of said permanent magnet 42, one annular, offset-shaped magnetic electrode 48 of a magnetically and electrically conductive material placed on each outside face of the aforementioned washer 44 so as to project the offset edges 50 of said magnetic electrodes 48 toward the outside of the so far described assembly of the chip detector 16, separated by the lateral surface 46A of the "T"-shaped part 46, providing an electrically and magnetically nonconductive debris gap spacer 46A and an annular member 54 of an electrically conductive material having an "L"-shaped cross-section is placed at the top of the chip detector parts, providing both electric debris shields and container means for the actual chip detector.
A bushing 56 (FIG. 1), of an electrically nonconductive material has a cross-section to accommodate the aforementioned chip detector parts.
A wavy washer 58 (FIG. 1), acting as a conductivity enhancer, is inserted between said annular member 54 and the nearest annular radial plane 60 (FIG. 3), of said bushing 56, thereby taking up all tolerance differentials.
An annular member 62 (FIG. 3) of any suitable metal and having a substantially "L"-shaped cross-section is arranged, partly, at the bottom of the chip detector assembly, partly along the lower lateral inside of said bushing 56 and spun about the latter to complete the chip detector assembly, under pressure of the now compressed wavy washer 58.
A hole 64 (FIG. 1), is formed in the bottom of the offset-shaped member 52 allowing for the chip detector installation on said stem 28, by means of the coupling nut 18, whereby said member 52 is abutting a preformed annular seal 66 (FIG. 3), and, conversely, the top of the annular channel 40 of the filter 14.
The entire assembly, described in the foregoing, is suitable for mounting on a vessel through its flanges 68, after the application of a downwardly open enclosure (not shown) mating with the "O"-ring 70, having the required inlet(s) and outlet(s) for the connection with a hydraulic system.
The internal electric signal or alarm circuit extends from one of the two terminal pins of the connector 26 to the grounded magnetic electrode 48A and debris shield 54 and past the electrically nonconductive debris gap spacer 46A from the ungrounded magnetic electrode 48 and debris shield 52 to the second terminal pin of the connector 26. The external signal circuit consists of a power source 72, arbitrarily of the d.c. kind, and, say, an indicating lamp 74 connected in series across those two terminal pins of the connector 26.
The significant operational phases of this filter and chip detector assembly are as follows:
The flow of, for example, lubricating oil occurs from the top of the chip detector 16, over its upper surface and past its periphery where the magnetic electrodes 48 and their faces 50 are exposed so as to arrest any ferrous particles floating in the passing oil stream and that before the stream enters the filter structure 14 for its processing of the fluid and eventual leaving the device for its own intended function.
When the quantity of ferrous chips collected is enough to bridge the exposed surface of the debris gap spacer 46A, the aforementioned electric circuit becomes closed and activates, for example, the indicating lamp 74, alerting personnel for the taking of remedial actions.
Depending on a considerable choice of circumstances, the filter 14 and the chip detector 16 may be used concurrently as suggested and described in this application, or individually within the basic structure of the housing 12. Comparable options are available concerning the inspection, servicing and replacement, respectively, of both the filter 14 and the chip detector 16 simultaneously or separately or of both together with the housing 12. It is also evident that the device shown and described herein in possible operational connection with lubricating fluids and systems, can readily be employed for numerous additional media, e.g. transmission and hydraulic fluids, and their dispositions.
Thus the invention includes an apparatus for the successive action of a chip detector and a filter in a liquid system in which a discrete chip detector is upstream with respect to a discrete filter unit and both are arranged within an enclosure. The chip detector has operationally active physical dimensions substantially identical with those of the filter. The apparatus includes a filter and chip detector assembly which attracts, retains, and indicates ferrous chips suspend in a liquid and for the successive filtering of the liquid. The assembly includes housing having means for mounting to a vessel and connection with a liquid system. The housing also has means for the installation of discrete operational units including a filter and a chip detector within its interior. An electric connector is included and means are provided for the wiring of one of the operational units with the connector. A discrete, cylindrical chip detector has a debris gap spacer mounted as the first element in the direction of the stream of the liquid through the housing. The debris gap spaces and the magnetic electrodes together can constitute the chip collection elements and are provided along the lateral surface of the cylindrical chip detector. Further the diameter of the cylindrical chip detector unit is at least as large as the diameter of the cylindrical filter element.
The chip detector can comprise an annular, permanent ferrous magnet having two pole faces and generating a magnetic field across the faces. At each face of the permanent ferrous magnet can be placed a magnetically and electrically nonconductive washer. A magnetic electrode can be incorporated so that its end face is placed at each pole face. The end face of each magnetic electrode can be spaced apart across a debris gap. Occupying the debris gas and separating the magnetic poles can be an annular electronically nonconductive member separator. One of the magnetic electrodes is connected e.g. by wiring, to the housing whereas the other magnetic electrode is connected, e.g. by wiring, to one of two connector terminals. A preferred embodiment is wherein a ceramic permanent magnet is in intimate contact with the magnetic electrodes.
The filtered and chip detector assembly can further include a discrete cylindrical filter mounted successively in the direction of the stream of the liquid through the housing. Also included is an electric alarm circuit adapted to become activated upon the collection of specific chip quantity across the debris gap spacer of the chip detector.
It is further understood that the herein shown and described embodiments, apparatus and units of the subject invention are but illustrative and that variations, modifications and alterations are feasible within the frame of these teachings.
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An arrangement of a standardized filter element for placing into a housing which is provided with an automatic bypass and with a pop-up botton type by-pass differential pressure indicator, selectively, and a set of at least two annular magnets positioned so as to form at the liquid flow entrance a chip arresting and detention gap among them and along their own peripheries and followed by the action along that of the filter element. One of the filter element sleeves and the grounded housing are utilized as conductors for the chip retention gap, leading to an electric connector for external wiring to a power source and indicating means.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0123019 filed Dec. 3, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to a hydraulic pump system for an automatic transmission that is configured to minimize a power loss caused by a hydraulic pump.
2. Description of Related Art
For example, a hydraulic pump that is operated by an engine has a suction hole that is connected to an oil fan to supply a discharge hole with pumped oil in a hydraulic pump system for an automatic transmission.
The discharge hole is connected to a high pressure portion (for example, clutch) through a high pressure passage, and a high pressure regulating valve is disposed on a high pressure passage. The high pressure passage supplies a high hydraulic pressure to the high pressure portion. Also, a pressure reduction valve is interposed on the high pressure passage to be connected to a low pressure passage. The low pressure passage supplies a low pressure portion to a low pressure portion (for example, lubrication portion).
The high pressure regulating valve and the pressure reduction valve set a high pressure and a low pressure to recirculate remained oil to a suction hole of the hydraulic pump. Generally, the low pressure portion is used to lubricate an automatic transmission and therefore large amount of oil is necessary and the high pressure portion is used to control a clutch and therefore small amount of oil is necessary.
However, the hydraulic pump pumps entire oil flux base on the high pressure portion and therefore an excessive load is applied to the pump. A durability is deteriorated, a power is lost, and noise and pressure vibration are generated thereby.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY OF INVENTION
Various aspects of the present invention provide for a hydraulic pump system for an automatic transmission having advantages of preventing excessive power loss and durability deterioration.
Various aspects of the present invention provide for a hydraulic pump system for an automatic transmission having advantages of pumping entire oil flux by a low pressure portion and discharging a necessary oil flux by a high pressure portion to reduce noise and pressure vibration of a hydraulic pump.
A hydraulic pump system for an automatic transmission according to various aspects of the present invention may include a first hydraulic pump that generates a first hydraulic pressure to supply a low pressure portion with the first hydraulic pump, a second hydraulic pump that receives the first hydraulic pressure to generate a second hydraulic pressure higher than the first hydraulic pressure and supplies a high pressure portion with the second hydraulic pressure, and a drive portion that rotates a drive shaft that integrally connects the first hydraulic pump with the second hydraulic pump.
The first hydraulic pump may be connected to an oil fan through a first suction hole to suck in oil and is connected to a low pressure portion through the first discharge hole to discharge the first hydraulic pressure, and the second hydraulic pump may suck the first hydraulic pressure through a connection passage that connects the first discharge hole with a second suction hole and is connected to the high pressure portion through the second discharge hole to discharge the second hydraulic pressure.
The first discharge hole may be connected to the low pressure portion through a low pressure passage and the second discharge hole may be connected to the high pressure portion through a high pressure passage.
A low pressure regulating valve that is connected to the low pressure passage may set the first hydraulic pressure to return remained oil to the oil fan.
The first switch valve that is connected to the high pressure passage may control a oil that is diverged from the second hydraulic pressure, and a high pressure regulating valve that is connected to the first switch valve may control oil passing the first switch valve that is turned on to set the second hydraulic pressure and recirculates remained oil to the second suction hole.
A second switch valve that is disposed on the high pressure passage may control the second hydraulic pressure that is supplied to the high pressure portion, supplies the high pressure portion with the second hydraulic pressure that is discharged from the second discharge hole by an operation of the first switch valve, and recirculates the first hydraulic pressure that is discharged from the second discharge hole by an disoperation of the first switch valve to the second suction hole.
The first switch valve and the second switch valve may be connected to a solenoid valve to be on/off controlled.
The hydraulic pump system for an automatic transmission may further include a first check valve that is disposed between the high pressure passage and the low pressure passage, and a second check valve that is disposed on the high pressure passage between the second switch valve and the high pressure portion.
The drive portion may include an engine or a motor.
A first oil flux of the first hydraulic pump may be larger than that of the second hydraulic pump.
In various embodiments of the present invention as described above, the first hydraulic pump discharges an entire oil flux based on a low pressure and the second hydraulic pump discharges a necessary high pressure such that an excessive load is not applied to the hydraulic pump to prevent a power loss and durability thereof. Also, noise and pressure vibration of the hydraulic pump can be reduced.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a hydraulic circuit diagram showing a condition that a high pressure portion of an exemplary hydraulic pump system for an automatic transmission is operated according to the present invention.
FIG. 2 is a schematic diagram of a hydraulic pump that is applied to FIG. 1 .
FIG. 3 is a hydraulic circuit diagram showing a condition that a high pressure portion of an exemplary hydraulic pump system for an automatic transmission is not operated according to the present invention.
DETAILED DESCRIPTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
FIG. 1 is a hydraulic circuit diagram showing a condition that a high pressure portion of a hydraulic pump system for an automatic transmission (hereinafter, it is referred to as “hydraulic pump system”) is operated according to various embodiments of the present invention. That is, the hydraulic pump system supplies a high pressure portion (for example, clutch) (C) with a high hydraulic pressure and supplies the low pressure portion (for example, lubrication portion) (L) with a low hydraulic pressure.
Referring to FIG. 1 , the hydraulic pump system according to various embodiments includes a first hydraulic pump 10 that generates a first hydraulic pressure (hereinafter, it is referred to as a “low pressure”), a second hydraulic pump 20 that generates a second hydraulic pressure (hereinafter, it is referred to as a “high pressure”), and a drive portion 40 that drives a drive shaft 31 of the first and second hydraulic pump 10 and 20 .
The low hydraulic pressure is supplied to the low pressure portion (L) of the automatic transmission to have a low pressure suitable to lubrication. The high hydraulic pressure is supplied to the high pressure portion (C) of the automatic transmission to have a high pressure suitable to effectively operate the clutch.
The drive portion 40 includes an engine or a motor to drive the drive shaft 31 such that the first and second hydraulic pump 10 and 20 are operated together. In this case, the first hydraulic pump 10 discharges a low hydraulic pressure to supply low pressure portion (L) with this and the second hydraulic pump 20 raises the low hydraulic pressure of the first hydraulic pump 10 to the high hydraulic pressure to supply the high pressure portion (C) with this.
FIG. 2 is a schematic diagram of a hydraulic pump that is applied to FIG. 1 . Referring to FIG. 2 , a first suction hole 11 is connected to an oil fan 50 , the first hydraulic pump 10 sucks oil through the first suction hole 11 , and the first discharge hole 12 is connected to the low pressure portion (L) to discharge a low hydraulic pressure to the first discharge hole 12 .
The second suction hole 21 is connected to the first discharge hole 12 through a connection passage 23 , the second hydraulic pump 20 sucks a low hydraulic pressure through the second suction hole 21 , and the second discharge hole 22 is connected to a high pressure portion (C) to supply a high hydraulic pressure.
The first and second hydraulic pump 10 and 20 is operated by a drive shaft 31 that is integrally formed to be built in a pump body. Accordingly, the connection passage 23 is formed between the first and second hydraulic pump 10 and 20 in the pump body 32 to connect the first discharge hole 12 with the second suction hole 21 . Accordingly, an equal hydraulic pressure i.e. a low pressure is applied to the first discharge hole 12 and the second suction hole 21 .
The oil of a low hydraulic pressure that is discharged by the first hydraulic pump 10 is larger than that of a high hydraulic pressure that is discharged from the second hydraulic pump 20 . The first hydraulic pump 10 discharges a total oil based on a low pressure, and the second hydraulic pump 20 boosts a pressure to discharge as much as it needs. Accordingly, a power loss for the hydraulic pump is minimized, durability is improved, and noise and pressure vibration of the hydraulic pump is reduced.
Referring to FIG. 1 , the first suction hole 11 of the first hydraulic pump 10 is connected to the oil fan 50 through the suction passage 13 and the first discharge hole 12 is connected to a low pressure portion (L) through the low pressure passage 61 . The second discharge hole 22 of the second hydraulic pump 20 is connected to the high pressure portion (C) through the high pressure passage 62 .
A low pressure regulating valve 14 is connected to a oil passage diverged from the low pressure passage 61 to be connected to the oil fan 50 through a recirculation passage 15 . Accordingly, the low pressure regulating valve 14 sets an oil of a low hydraulic pressure that is supplied to the low pressure passage 61 and recirculates a remained oil to the oil fan 50 through the recirculation passage 15 . That is, a predetermined oil of low pressure is formed in the low pressure passage 61 according to the oil that is recirculated to the oil fan 50 from the low pressure regulating valve 14 .
The first switch valve 71 is connected to an oil passage that is diverged from the high pressure passage 62 and is on/off controlled by a solenoid valve 51 to regulate an oil of the high pressure passage 62 .
That is, while the first switch valve 71 is turned on (refers to FIG. 1 ), a high hydraulic pressure of the high pressure passage 62 is transferred from an inflow port 711 to an outflow port 712 , and while the first switch valve 71 is turned off (refers to FIG. 3 ), a low hydraulic pressure of the high pressure passage 62 is disconnected between the inflow port 711 and the outflow port 712 .
The high pressure regulating valve 24 is connected to an outflow port 712 of the first switch valve 71 to be connected to the second suction hole 21 of the second hydraulic pump 20 through a recirculation passage 25 . Also, the high pressure regulating valve 24 controls an oil of high pressure during an ‘ON’ of the first switch valve 71 and stops its operating during an ‘OFF’ thereof.
Accordingly, the high pressure regulating valve 24 sets a hydraulic pressure passing the first switch valve 71 to set an oil flux that is supplied to the high pressure passage 62 and recirculates a remained oil to the second suction hole 21 of the second hydraulic pump 20 . That is, an oil of a predetermined high pressure is formed in the high pressure passage 62 according to an oil that is recirculated to the second suction hole 21 of the second hydraulic pump 20 through the high pressure regulating valve 24 .
The second switch valve 72 is disposed on the high pressure passage 62 and is turned off or on by the solenoid valve 51 to regulate a high hydraulic pressure supplied to the high pressure portion (C).
That is, while the first switch valve 71 is turned on, the second switch valve 72 supplies an oil of high hydraulic pressure discharged from the second discharge hole 22 to the high pressure portion (C) (refers to FIG. 1 ), and while the first switch valve 71 is turned off, the second switch valve 72 recirculates an oil of low hydraulic pressure discharged from the second discharge hole 22 to the second suction hole 21 (refers to FIG. 3 ).
Also, a first check valve 81 is disposed between the high pressure passage 62 and the low pressure passage 61 to supply the high pressure portion (C) with a low hydraulic pressure from the low pressure passage 61 to lubricate the high pressure portion (C) that is not operated, while a high hydraulic pressure is not supplied to the high pressure passage 62 .
The second check valve 82 is disposed between the second switch valve 72 and the high pressure portion (C) on the high pressure passage 62 to prevent a low hydraulic pressure supplied to the high pressure portion (C) from being supplied to the second switch valve 72 .
Overall operations of a hydraulic pump system according to various embodiments will be described. Referring to FIG. 1 , the first and second hydraulic pump 10 and 20 are operated by the drive shaft 31 that is rotated by the drive portion 40 .
A high hydraulic pressure that is discharged from the first hydraulic pump 10 to be controlled by the low pressure regulating valve 14 is supplied to the low pressure portion (L) through the low pressure passage 61 to lubricate the low pressure portion (L).
A low hydraulic pressure that is supplied from the first hydraulic pump 10 to the second hydraulic pump 20 through the connection passage 23 is boosted by the second hydraulic pump 20 . The boosted high hydraulic pressure is supplied to the high pressure portion (C) through the high pressure passage 62 to operate this. The second switch valve 72 cuts off the second suction hole 21 of the second hydraulic pump 20 from the high pressure passage 62 . This case includes a condition that the high pressure portion (C) i.e. the clutch is operated while the vehicle accelerates or travels a slant road.
That is, the solenoid valve 51 is turned off and the first and second switch valve 71 and 72 are turned on. A high hydraulic pressure supplied to the high pressure passage 62 passes the first switch valve 71 and is controlled by the high pressure regulating valve 24 to have a predetermined high pressure. A high hydraulic pressure passes the second switch valve 72 turned on to be supplied to the high pressure portion (C).
FIG. 3 is a hydraulic circuit diagram showing a condition that a high pressure portion of a hydraulic pump system for an automatic transmission is not operated according to various embodiments of the present invention. Referring to FIG. 3 , a low hydraulic pressure that is discharged from the first hydraulic pump 10 to be controlled by the low pressure regulating valve 14 is supplied to the low pressure portion (L) through the low pressure passage 61 to lubricate this.
Also, a low hydraulic pressure that is supplied to the high pressure passage 62 from the low pressure passage 61 through the first check valve 81 is supplied to the high pressure portion (C) to lubricate the high pressure portion (C).
A low hydraulic pressure that is supplied to the second hydraulic pump 20 from the first hydraulic pump 10 through the connection passage 23 is discharged from the second hydraulic pump 20 . A low hydraulic pressure is recirculated to the second hydraulic pump 20 through the high pressure passage 62 . In this case, the second switch valve 72 connects the second suction hole 21 of the second hydraulic pump 20 with the high pressure passage 62 . This case includes a condition that the high pressure portion (C) i.e. a clutch is not operated while the vehicle travels a flat road.
That is, the solenoid valve 51 is controlled to be turned on and the first and second switch valve 71 and 72 are controlled to be turned off. A low hydraulic pressure supplied to the high pressure passage 62 is cut off by the first switch valve 71 that is turned off to not be boosted and passes the second switch valve 72 that is turned off to be recirculated to the second hydraulic pump 20 .
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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A hydraulic pump system for an automatic transmission has the advantages of preventing excessive power loss and durability deterioration. The hydraulic pump system may include a first hydraulic pump that generates a first hydraulic pressure to supply a low pressure portion with the first hydraulic pump, a second hydraulic pump that receives the first hydraulic pressure to generate a second hydraulic pressure higher than the first hydraulic pressure and supplies a high pressure portion with the second hydraulic pressure, and a drive portion that rotates a drive shaft that integrally connects the first hydraulic pump with the second hydraulic pump.
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BACKGROUND OF THE INVENTION
This invention relates generally to a snow guard for mounting on a raised seam roof and, more particularly, to a mounting bracket that engages the raised seam portion of a roof structure to support a snow guard thereon.
Raised seam roofs are formed with panels manufactured from sheet metal or other suitable building materials with a flat panel that runs from the peak of the roof to the lower edge thereof. These panels are joined together by a formed edges that projects upwardly above the flat surface of the panel. The formed edges of adjacent panels are interlocked to fix the panels together in a sealed seam that is raised above the otherwise planar surface of the panels. Clips can be connected to the raised seams to tie into the frame structure of the building immediately beneath the seams, thereby fixing the roofing material which the panels form to the building. The sealed seams and the lower planar surfaces of the panels provide a watertight barrier against moisture provided that the panels, including the raised seams, are not punctured. Attaching devices to a raised seam roof without puncturing the panels or the sealed raised seams is a problem that has been appreciated for many years.
Raised seam roofs with the planar surfaces running from the roof peak to the roof edge do not retain snow on the roof surface as any accumulated snow tends to slide downwardly along the planar surfaces, particularly after the snow has partially melted to form a moisture layer between the roof panels and the accumulated snow. One of the most frequently needed devices to be attached to raised seam roofs is a snow guard which is operable to restrict the movement of accumulated snow off the roof panels. Other devices are often needed to be mounted on the roof, such as lightening rods, antennas, or support structures for both people and other apparatus such as air conditioners, etc. A device that can engage the raised seam roof to permit such devices to be mounted thereon without causing the roof or the raised seam thereof to be perforated has been contemplated for many years.
One of the early mechanisms for mounting devices on raised seam roofs can be found in U.S. Pat. No. 1,330,309, issued to R. T. Dixon on Feb. 10, 1920. The Dixon mechanism includes an elongated channel member having a cavity formed therein to receive the raised seam portion of the roof panel structure. A mounting bolt is received within a transverse threaded bore to engage the raised seam portion within the cavity of the channel member to deform the raised seam into a formed pocket, thereby affixing the channel member to the raised seam portion of the roof. A board rest member is formed as part of the channel member to permit the detachable mounting of devices, such as a snow guard, to the channel member.
A number of patents, including U.S. Pat. No. 5,228,248; U.S. Pat. No. 5,483,772; U.S. Pat. No. 5,491,931; U.S. Pat. No. 5,983,588; and U.S. Pat. No. 6,164,033 were issued to Robert M. M. Haddock for a mounting member that, like the Dixon patent, is affixed to the raised seam portion of a roof structure without puncturing the surface of the roof panels by a fastener that engages and deforms the raised seam portion. The Haddock mounting members typically require two fasteners for stability and are formed with cavities extending through the body of the mounting member to attach devices, such as a snow fence or decorative attachments, to the mounting member.
U.S. Pat. No. 5,282,340; U.S. Pat. No. D364,338; U.S. Pat. No. D372,421; and U.S. Pat. No. 5,522,185 were issued to Roger M. Cline, et al. for various configurations of snow guards which are formed to be mounted on the raised seam portion of a roof structure. Like the Dixon and Haddock patents, the mounting of the snow guard involves the utilization of a fastener that is threaded into a body portion of the snow guard to engage and deform the raised seam portion of the roof structure to affix the snow guard to the roof. The snow guard structure includes a transversely extending body manufactured in a formed shape to present an esthetically pleasing device to be exposed on the surface of the roof.
U.S. Pat. No. 884,850, issued on Apr. 14, 1908, to F. A. Peter, is directed to a snow guard having a body member that straddles a raised seam portion of a roof to mount the snow guard without piercing the surface of the roof or the seam structure. The body member is formed in two opposing halves and is clamped onto the raised seam by a bolt that passes above the seam to interengage the opposing sides of the body member and effect a clamping action on the seam structure. While the Peter mechanism does not cause a deformation of the raised seam structure of the roof, the clamping action is indirect and does not provide a substantial affixation of the snow guard to the roof structure.
Accordingly, it would be desirable to provide a mounting bracket and associated snow guard therefor that would effectively mount on a raised seam roof structure without causing a deformation of the raised seam portion of the roof.
Furthermore, the raised seam portion of such roofs are formed with different shapes and sizes, which is not contemplated by most of the aforementioned prior art snow guard mounting members. Accordingly, it would be desirable to provide an apparatus for mounting devices to a raised seam roof that would be at least somewhat universal in application to accommodate different sizes and shapes of the raised seam portions.
SUMMARY OF THE INVENTION
It is an object of this invention to overcome the disadvantages of the prior art by providing a bracket for mounting a snow guard on a raised seam roof.
It is another object of this invention to provide a mounting bracket for attaching devices to a raised seam roof structure without deforming the raised seam structure.
It is a feature of this invention that the mounting bracket clamps onto the raised seam portion of a roof structure without deforming or penetrating the structure of the roof.
It is an advantage of this invention that the clamping action of the mounting bracket incorporating the principles of the instant invention is effected through manipulation of a single bolt.
It is another advantage of this invention that the mounting bracket utilizes a pair of opposing clamping jaws to grip the raised seam portion of a roof structure.
It is another feature of this invention that one of the clamping jaws of the mounting bracket is fixed to a body member.
It is still another feature of this invention that a second clamping jaw is movable in conjunction with a threaded bolt to advance toward the fixed clamping jaw to grip a raised seam structure between the two opposing clamping jaws.
It is still another advantage of this invention that the clamping jaws are removable from the body member of the mounting bracket to provide flexibility in accommodating different sizes and shapes of raised seam structures.
It is still another object of this invention to provide a mounting bracket that has a universal nature in accommodating a variety of sizes and shapes of raised seam roof structures.
It is yet another feature of this invention that the body member defines a large cavity within which the clamping jaws operate to provide a wide opening for receiving the raised seam structure.
It is yet another object of this invention that the mounting bracket incorporates a quick attach implement mounting system for receiving devices to be mounted on a raised seam roof.
It is further feature of this invention that the implement mounting system is formed with a wedge-shaped opening and a fastener that locks an implement to the top of the mounting bracket.
It is a still another advantage of this invention that the implement or device to be mounted on top of the mounting bracket can be quickly and easily replaced.
It is a further object of this invention to provide a snow guard device that can be attached to a mounting bracket to retain snow on the surface of an inclined raised roof structure.
It is still a further object of this invention to provide a mounting bracket for mounting devices to the surface of a raised seam roof structure, which is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.
These and other objects, features and advantages are accomplished according to the instant invention by providing a mounting bracket for attaching implements and other devices to the top surface of an inclined raised seam roof structure. The mounting bracket is formed with a body portion defining a wide cavity between opposing side walls to accommodate a variety of different sizes and shapes of raised seam configurations. A pair of opposing clamping jaws are disposed within the body cavity. One clamping jaw is fixed to a side of the body member, while the other clamping jaw is movably mounted to a threaded fastener that advances the movable clamping jaw toward the fixed clamping jaw and grip a raised seam structure therebetween. The body portion has a wedge-shaped receptacle on the top surface to mount devices such as a snow guard, which can be locked into place on the mounting bracket by a threaded fastener.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a side elevational view of a first embodiment of a mounting bracket incorporating the principles of the instant invention, the movement of the movable clamping jaw and associated fastener being shown in dotted lines;
FIG. 2 is a top plan view of the mounting bracket depicted in FIG. 1 showing the wedge-shaped implement mounting receptacle;
FIG. 3 is a side elevational view of the mounting bracket of FIG. 1 ;
FIG. 4 is an enlarged detail view of the actuating fastener associated with the movable clamping jaw, as depicted in FIG. 1 ;
FIG. 4A is an enlarged detail view of an alternative fastener assembly associated with the movable clamping jaw;
FIG. 5 is a side elevational view of an alternative embodiment of a body member of a mounting bracket incorporating the principles of the instant invention;
FIG. 6 is a side elevational view of the mounting bracket body member depicted in FIG. 5 taken perpendicularly to the view of FIG. 5 ;
FIG. 7 is a bottom plan view of the mounting bracket body member depicted in FIG. 5 ;
FIG. 8 is an enlarged side elevational view of the fixed clamping jaw for the mounting bracket body member depicted in FIG. 5 ;
FIG. 8A is an enlarged side elevational view of the fixed clamping jaw corresponding to lines 8 A— 8 A of FIG. 8 ;
FIG. 9 is an enlarged side elevational view of the movable clamping jaw for the mounting bracket body member depicted in FIG. 5 ;
FIG. 10 is an enlarged side elevational view of the movable clamping jaw corresponding to lines 10 — 10 of FIG. 9 ;
FIG. 11 is an elevational view of the snow guard attachment for mounting in the mounting receptacle of the mounting bracket;
FIG. 12 is a bottom plan view of the snow guard attachment of FIG. 11 ;
FIG. 13 is a side elevational view of the snow guard attachment orthogonal to the view of FIG. 11 and corresponding to lines 13 — 13 of FIG. 14 ;
FIG. 14 is a rear elevational view of the snow guard attachment looking perpendicularly to the body portion of the attachment, corresponding to lines 14 — 14 of FIG. 13 ;
FIG. 15 is an elevational view of the alternative embodiment of the mounting bracket assembly with the snow guard attachment mounted thereon, the fastener assembly of FIG. 4A being used to mount and adjustably move the movable clamping jaw;
FIG. 16 is a side elevational view of the mounting bracket assembly perpendicular to the view of FIG. 15 and corresponding to lines 16 — 16 of FIG. 15 ; and
FIG. 17 is a side elevational view of the mounting bracket assembly opposite to that of FIG. 16 and corresponding to lines 17 — 17 of FIG. 15 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1–3 , a first embodiment of a mounting bracket incorporating the principles of the instant invention can best be seen. In the embodiment of FIGS. 1–3 , the mounting bracket 10 has an inverted U-shaped body member 111 that defines a cavity 13 between the two opposing side walls 14 a , 14 b . The width and height of the cavity 13 is sufficient to receive substantially all sizes and configurations of raised seam portions of roofs. Supported on the adjacent side walls 14 are clamping jaws 15 , 20 that physically engage the raised seam portion (not shown) of the roof to affix the mounting bracket 10 to the roof structure.
The fixed clamping jaw 15 is preferably formed with a serrated gripping surface 16 and is supported in the side wall 14 by a pin member 17 that extends into a hole 39 formed in the side wall 14 a . In addition, the side wall 14 a may be formed with a serrated portion 18 that interacts with corresponding serrations on the adjacent side of the fixed clamping jaw 15 to further support the fixed clamping jaw 15 on the body member 11 and restrict generally vertical movement of the fixed clamping jaw 15 relative to the side wall 14 a , particularly when mounted on a raised roof seam (not shown). One skilled in the art will recognize that the fixed clamping jaw 15 can be sized, particularly with respect to the depth to which the fixed clamping jaw 15 extends into the cavity 13 from the side wall 14 a , to conform to the specific shape and size of the raised roof seam (not shown) that will be engaged by the fixed clamping jaw 15 . Furthermore, the shape of the fixed clamping jaw 15 can be varied to conform to the shape of the raised roof seam to be engaged. The fixed clamping jaw 15 is also preferably formed with a support leg 19 that underlies the side wall 14 a to further stabilize the position of the fixed clamping jaw 15 on the side wall 14 a.
On the opposing side wall 14 b , a movable clamping jaw 20 is mounted. Similar to the fixed clamping jaw 15 , the movable clamping jaw 20 is preferably formed with a serrated gripping surface 22 for engagement with the raised roof seam (not shown) to which the mounting bracket 10 is to be affixed. Further like the fixed clamping jaw 15 , the movable clamping jaw 20 can be formed in an appropriate size and shape to conform to the configuration of the raised roof seam to be engaged. The movable clamping jaw 20 is also formed with a support leg 24 underlying the side wall 14 b to provide stabilizing support for the movable clamping jaw 20 . The movable clamping jaw 20 is operatively engaged with a threaded fastener 25 , best seen in FIG. 4 , or alternatively in FIG. 4A , to effect movement relative to the side wall 14 b toward or away from the fixed clamping jaw 15 . The fastener 25 is threaded into a hole 21 formed in the side wall 14 b to permit translational movement of the fastener 25 within the side wall 14 b.
Referring now to FIG. 4 , the fastener 25 is formed with a smooth surfaced pin portion 27 that projects into an opening 23 in the movable clamping jaw 20 . The pin portion 27 has a smaller diameter than the threaded portion 28 of the fastener 25 , thus forming a shoulder 29 against which the movable clamping jaw 20 can be engaged by the fastener 25 . Therefore, the manipulation of the hex head 26 of the fastener 25 to effect rotation thereof within the threaded opening within the side wall 14 b will cause translational movement of the fastener 25 through the side wall 14 b to force the shoulder 29 against the movable clamping jaw 20 . This movement will push the movable clamping jaw 20 toward the fixed clamping jaw 15 to trap a raised roof seam (not shown) therebetween, as is depicted in phantom in FIG. 1 .
The top surface 12 of the U-shaped body member 11 is formed with an attachment receptacle 30 for mounting implements and/or attachments to the mounting bracket 10 . The attachment receptacle 30 is formed as a relief depression 31 into the top surface 12 . The depression 31 preferably extends across the entire top surface 12 from side wall 14 a to side wall 14 b and has a first generally vertical edge 32 and an inwardly beveled wedging edge 33 opposite to the vertical edge 32 . The depression 31 is operable to receive an attachment formed with a correspondingly matched base member, as will be described in greater detail below. An aperture 34 extending vertically through the top surface 12 of the body member 11 will permit a locking fastener 50 to engage the attachment seated within the depression 31 to lock the attachment to the mounting bracket 10 , as will also be described in greater detail below.
An alternative configuration of the mounting bracket 10 is depicted in FIGS. 5–10 . Compared to the configuration described above with respect to FIGS. 1–3 , the body member 11 has a slightly different shape. As seen in FIG. 5 , the side wall 14 a corresponding to the fixed clamping jaw 15 is formed with a notch 35 on the interior surface thereof to engage a correspondingly shaped node 37 on the fixed clamping jaw 15 , which is depicted in FIGS. 7 , 8 and 8 A. The interengagement between the node 37 and the notch 35 restricts vertical movement of the fixed clamping jaw 15 relative to the side wall 14 a to provide stability to the assembled mounting bracket 10 . The opening 39 in the side wall 14 a is preferably aligned with a threaded opening 38 in the fixed clamping jaw 15 so that a set screw (not shown) can engage the fixed clamping jaw 15 for affixation to the body member 11 . A receptor 37 a is formed on the node 37 to engage the threaded opening 38 and receive the set screw (not shown).
The dimensions of the body member 11 , i.e. the thicknesses of the top surface 12 and the side walls 14 a , 14 b , are greater than in the configuration depicted in FIGS. 1–3 to provide greater strength in mounting attachments to the receptacle 30 on the top surface 12 and to resist deformation of the body member 11 when placing a clamping load on the clamping jaws 15 , 20 to affix the mounting bracket 10 to a raised roof seam (not shown). The aperture 34 can be formed with a countersink relief 34 a defining a shoulder against which the fastener 50 can lock the attachment to the receptacle 30 . The relief 34 a can be shaped and sized deep enough to countersink the head of the locking fastener 50 within the body member 11 so that the head would not protrude into the cavity 13 formed by the body member 11 and interfere with the reception of the raised roof seam.
Both the fixed and movable clamping jaws 15 , 20 depicted in FIGS. 7–10 reflect the differences in shape and/or size of the clamping jaws 15 , 20 that can be provided to accommodate different raised seam configurations. The upper portion of the structure of both the fixed and movable clamping jaws 15 , 20 have been eliminated with a arcuate surface that will deflect moisture downwardly to the surface of the roof. The elimination of this part of the clamping jaws 15 , 20 , as compared with the shape of the clamping jaws 15 , 20 depicted in FIG. 1 , permits an even greater range of raised seam configurations to be accommodated within the cavity 13 . Still other sizes and shapes of the clamping jaws 15 , 20 are within the scope of the instant invention.
The movable clamping jaw 20 is best seen in FIGS. 9 and 10 . The opening 23 passing through the movable clamping jaw 20 is sized to receive a fastener assembly 60 , which is best seen in FIG. 4A . The opening 23 is not threaded and has a first countersink relief opening 23 a to receive the head 62 of the fastener 61 , as will be described in greater detail below. The movable jaw 20 is also preferably formed with a receiving shoulder 23 b that can be depressed into the body of the movable clamping jaw 20 and positioned concentric with the opening 23 . This configuration of the opening 23 conforms with the configuration of the alternative fastener assembly 60 shown in FIG. 4A .
The fastener assembly 60 shown in FIG. 4A has a threaded member 65 that engages the threaded hole 21 in the side wall 14 b and projects into and engages the receiving shoulder 23 b in the movable clamping jaw 20 . The threaded member has a hex depression 66 to receive an Allen wrench or other similar tool to effect rotation of the threaded portion 65 . The fastener 61 is engagable with a threaded opening 67 in the opposing end of the threaded member from the hex depression 66 . The head 62 of the fastener 61 is received in the countersink relief 23 a to lock the movable clamping jaw 20 to the threaded member 65 . Since the fastener 61 is not threadably engaged with the movable clamping jaw 20 , the rotation of the fastener assembly 60 to effect a translational movement of the threaded member 65 relative to the side wall 14 b will not cause a corresponding rotation of the movable clamping jaw 20 , particularly since the support leg 24 is positioned beneath the side wall 14 b.
To effect movement of the movable clamping jaw 20 , the tool is inserted into the hex depression 66 to effect rotation of the threaded member 65 . The threaded member 65 pushes against the receiving shoulder 23 b to move the movable clamping jaw 20 toward the fixed clamping jaw 15 until the raised seam of the roof (not shown) is firmly engaged between the two clamping jaws 15 , 20 . To release the movable clamping jaw 20 from the raised seam of the roof, the tool is inserted into the hex depression 66 to rotate the threaded member 65 in the opposite direction. Since the head 62 of the fastener 61 clamps the movable clamping jaw 20 onto the threaded member 65 by the engagement with the countersink relief 23 a , the movable clamping jaw 20 will be retracted back toward the side wall 14 b.
A representative attachment in the form of a snow guard 40 can be seen in FIGS. 11–14 . The snow guard 40 is formed in a transversely extending body 42 having a shape that extends laterally of the mounting bracket 10 and projects downwardly to come into close proximity or into engagement with the flat surface (not shown) of the roof panel to either side of the mounting bracket 10 to which the snow guard 40 is to be mounted. In the configuration depicted in FIGS. 11–17 , the transversely extending body 42 of the snow guard 40 is shaped like a bird whose wings 43 extend downwardly, as will be described in greater detail below. The body 42 is integrally formed with a base member 45 that is configured to be received within the receptacle 30 on the top surface 11 of the mounting bracket 10 . The base member 45 is formed with a first generally perpendicular edge 46 that corresponds to the vertical edge 32 of the receptacle depression 31 on the top surface 12 of the body member 11 , and with a beveled edge 47 that corresponds to the wedging edge 33 .
The body 42 is angled preferably at about 60 degrees to the base member 45 , as is best seen in FIG. 13 , to orient the body 42 in a more perpendicular orientation with respect to the plane of the roof when attached to a mounting bracket 10 affixed to a raised roof seam. If, for example, the roof was pitched at a 30 degree angle, the body 42 would then be literally perpendicular to the plane of the roof to provide resistance to the movement of snow downwardly over the surface of the roof. To resist the bending forces that are exerted on the body 42 of the snow guard 40 , integral braces 48 extend fore-and-aft between the body 42 and the base member 45 . The brace 48 on the uphill side of the snow guard 40 will receive a threaded passage 49 that is alignable with the aperture 34 in the top surface 12 of the body member 11 to permit engagement with the locking fastener 50 that fixes the attachment 40 to the body member 11 .
One skilled in the art will readily recognize that many different attachments can be formed with a base member 45 that can be received by the attachment receptacle 30 . Snow guards 40 can be formed in many different shapes and sizes for mounting on the mounting bracket 10 . A snow fence (not shown), which would be equipped with a plurality of base members 45 that would be received with a corresponding number of mounting brackets 10 mounted generally parallel to the peak of the roof structure, would be an alternative example of a snow guard. Other attachments can be antennas, display signs, air conditioning units, ladders and walk ways. All such configured attachments can be quickly and easily attached to the mounting bracket by receiving the base member into the attachment receptacle 30 and connecting the locking fastener 50 to fix the base member 45 to the top surface 12 of the body member 11 .
Referring now to FIGS. 15–17 , an assembled snow guard 40 on a mounting bracket 10 can best be seen. The mounting bracket 10 is of the configuration depicted in FIGS. 5–10 , utilizing the fastener assembly 60 of FIG. 4A , and is mounted on a representative raised seam portion 55 of a roof structure that projects vertically above the flat surface 57 of the roof panels 59 . The snow guard 40 is mounted in the attachment receptacle 30 with the wings 43 extending downwardly to a position just above the flat surface 57 . The transversely extending body 42 of the snow guard 40 presents a barrier to the movement of snow over the flat surface 57 of the roof panel 59 .
The snow guard 40 is attached to the mounting bracket 10 by slipping the base member 45 into the depression 31 on the top surface 12 of the body member 11 of the mounting bracket 10 with the beveled edge 47 positioned underneath the wedging edge 33 . The locking fastener 50 is then inserted from within the cavity 13 through the aperture 34 into the threaded passage 49 in the base member 45 of the snow guard 40 , thus fixing the base member 45 to the top surface 12 of the body member 11 . One skilled in the art will readily recognize that a different form of attachment could utilize a locking fastener 50 that is inserted through the attachment from above the mounting bracket 10 and engaged into the aperture 34 which would be threaded to engage the locking fastener 50 . In such a configuration, however, the locking fastener 50 would not be protected from beneath the top surface 12 of the body member 11 .
The mounting bracket 10 with the snow guard 40 mounted thereon is then positioned over top of the raised seam portion 55 with the fixed clamping jaw 15 on one side of the raised seam 55 and the movable clamping jaw 20 on the opposing side of the raised seam 55 . The threaded fastener assembly 60 , which is threadably received in the side wall 14 b , is then rotated to push the movable jaw 20 inwardly toward the raised seam 55 until the raised seam 55 is firmly clamped between the two opposing clamping jaws 15 , 20 , thus fixing the mounting bracket 10 and attachment 40 on the raised seam 55 with the manipulation of only a single fastener assembly 60 . The clamping forces asserted by the movable clamping jaw 20 manipulated through the single fastener assembly 60 are spread across the entire length of the clamping jaws 15 , 20 to prevent tipping or other movement of the mounting bracket 10 relative to the raised seam 55 .
To remove the mounting bracket 10 from the raised seam 55 , or to detach the snow guard 40 of the configuration shown in FIGS. 15–17 , the fastener assembly 60 is manipulated to withdraw from the side wall 14 b , thus drawing the movable clamping jaw 20 by the fastener 61 away from the raised seam and releasing the clamping forces exerted on the raised seam 55 , until the movable clamping jaw 20 can be disengaged from the raised seam 55 . The mounting bracket 10 can then be removed from the raised seam 55 so that the locking fastener 50 can be accessed. A removal of the locking fastener 50 will permit the snow guard attachment 40 to be released from the attachment receptacle, thus permitting the installation of another attachment or the replacement of the snow guard 40 .
It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention.
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A mounting bracket attaches implements and other devices to the top surface of an inclined raised seam roof structure. The mounting bracket is formed with a body portion defining a wide cavity between opposing side walls to accommodate a variety of different sizes and shapes of raised seam configurations. A pair of opposing clamping jaws are disposed within the body cavity. One clamping jaw is fixed to a side of the body member, while the other clamping jaw is movably mounted to a threaded fastener that advances the movable clamping jaw toward the fixed clamping jaw and grip a raised seam structure therebetween. The body portion has a wedge-shaped receptacle on the top surface to mount devices such as a snow guard, which can be locked into place on the mounting bracket by a threaded fastener.
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BACKGROUND OF THE INVENTION
This invention relates to electronic timepieces, and in particular, to electronic timepieces provided with a digital time indication formed from a liquid crystal display, a light emitting diode display or the like.
In the art, separate correcting switches are generally provided for each digit to be corrected, an arrangement which occupies a great deal of the limited space available in a small electronic timepiece such as a wrist watch, as well as being costly. By providing an arrangement wherein a plurality of digits of time display may be corrected by means of two switches, the foregoing deficiencies are avoided.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the invention, an electronic timepiece having a multi-digit digital display of time is provided with time correcting circuit means including a manually operable selecting switch and a manually operable correcting switch. Said circuit means is adapted to select at least one of said digits of time for correction in response to the operation of said selecting switch and to correct the selected digit by the operation of said correcting switch. Said circuit means further includes means for selectively actuating the selected digits so as to provide a visual indication of selection. Said visual indication of selection may constitute the flickering of the digits to be corrected.
Accordingly, it is an object of this invention to provide a time correcting apparatus for an electronic timepiece which is simple in structure and of high reliability, and whereby time correction can be readily achieved.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and drawings.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a top plan view of an electronic timepiece in accordance with the invention;
FIG. 2 is a circuit diagram of the electronic timepiece of FIG. 1;
FIG. 3 is a circuit diagram of the control circuit of FIG. 2; and
FIG. 4 is a timing chart of the circuit of FIGS. 2 and 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the electronic wrist watch depicted is provided for purposes of illustration with a liquid crystal display adapted to display date, day, hour, minute and second it being understood that such display could include light emitting diodes or the like. Two push buttons are mounted on the front of the case of the watch, the first, push button S S is a selecting switch for selecting the digit to be corrected. As used herein, a digit can refer to one of the two digits representative of each of the second, minute, hour and day displays, or to both of the respective digits. Further, it can refer to one of the seven days of the week, or to all of the seven days of the week. The second push button S A is a correcting switch for correcting the selected digit. Thus, in the watch of FIG. 1, the minutes digit reads "34." If the minute digit is selected by selecting switch S S , the digit starts flickering or blinking. With each depression of correcting switch S A , the number appearing in the minute display is indexed so as to increase by one to effect time correction. By operating selector switch S S , each of the other digits of time can be selected for correction.
The watch is provided with a crown S L on the side thereof which constitutes a safety watch. When said crown is pushed in, a safety circuit is actuated and push buttons S S and S A are deactivated and will not function even if pushed. In order to render the push buttons operative, the safety circuit must be released by pulling out crown S L .
The circuit of the electronic timepiece in accordance with the invention is shown in the block diagram of FIG. 2, wherein the high frequency time standard signal of a crystal oscillator X (for example 16,384 Hz) is divided by a counter chain consisting of six stages 1-6. Counter 1 divides the high frequency timing signal into a 1-second signal. Counter 2 divides the 1-second signal into a 1-minute signal, counting 60 seconds. Counter 3 divides the 1-minute signal into a 1-hour signal, counting 60 minutes. Counter 4 divides the 1-hour signal into a 1-day signal, counting 24 hours. Counter 5 divides the 1-day signal into a 1-month signal by counting 31 days. The counter 6 likewise divides the 1-day signal, but to produce a 1-week signal, counting the 7 days of the week.
A decoder 7-11 is connected to receive the BCD output signal of each of counters 2-6 to transform the BCD code signal outputs of said counters into a decimal signal DEC for actuating the corresponding liquid crystal displays representative of second (L S ), minute (L M ), hour (L H ), date (L D ) and day of the week (L W ). Each decoder is connected to its respective liquid crystal display through a NAND gate circuit, the other input to each of said NAND gates being from control circuit 12. Thus, output S b of control circuit 12 is coupled to the NAND gate associated with the second liquid crystal display L S . In like manner, control circuit 12 outputs M b , H b , D b , W b are respectively connected to the NAND gate associated with minute liquid crystal display L M , hour liquid crystal display L H day liquid crystal display L D and day of the week liquid crystal display L W . During normal operation of the watch, the outputs S b , M b , H b , D b and W b are at a high state and the liquid crystal displays are driven normally by the decimal outputs of the respective decoders 7-11.
When safety switch S L is pulled out to permit time correction, a low frequency signal F of a frequency from 20 Hz to several Hz from counter 1 is applied through control circuit 12 to the digit selected for correction through one of output S b , M b , H b , D b or W b . For example, if the minute digit is to be corrected, the low frequency signal F is applied through circuit M b to the NAND gate between decoder 8 and liquid crystal display L M so that said liquid crystal display is switched on and off at the frequency of low frequency signal F. Since the frequency of signal F is selected so that the rate of switching of the selected liquid crystal display elements can be detected by the user's eyes, the selected display is flickered and can clearly be distinguished from the other displays which are continuously displayed.
Also during time correction, the signal applied by correcting switch S A is applied through control circuit 12 to the selected one of outputs S a , M a , H a , D a and W a which are respectively connected to the correcting terminal ADJ of one of counters 2-6 for the selective correction of the setting of the selected digit.
Referring to FIGS. 3 and 4, we find a circuit diagram for control circuit 12 and a timing chart for certain of the signals thereof.
Control circuit 12 includes three D-type flip-flops FF 1 , FF 2 and FF 3 connected to form a hexadic Johnson counter. Safety switch S L is connected to the reset terminal R of the three flip-flops.
Selection switch S S is connected to input terminal CL of the three flip-flops. The outputs Q and Q of the three flip-flops are directly coupled to NOR gates N 1 through N 5 . The output of NOR gates N 1 through N 5 are coupled to a control terminal of NAND gates G 1 through G 10 in the manner depicted. The NAND gates circuits are conventional NAND gates having the following truth tables: ##STR1## As is understood, A is a signal for controlling the gate. B is a signal passing through the gate. As is further depicted in the second Table above, when A is 0 (zero), the gate is closed and when A is 1 the gate is open. As is further noted, when the signal B passes through the gate, a signal having the opposite phase B is obtained.
Similar NOR gates N 1 through N 5 are conventional NOR gates having a truth table as follows: ##STR2##
Finally, a D-type flip-flop is depicted in FIG. 3 has the following truth table: ##STR3## It is noted that when CL is changed from 0 to 1, the signal applied to the D terminal is written in by Q and the complement thereof D becomes the output signal of Q. Similarly, when CL is changed from 1 to 0, Q and Q are not changed.
In operation when safety switch S L is pushed in, a positive potential illustrated as t1 and t3 in FIG. 4, is applied to reset terminal R to thereby reset the flip-flops. Accordingly, NAND gates G 1 , G 2 , . . . G 10 are all closed, and correcting switch S A and selecting switch S S cannot be actuated. As is depicted in FIG. 4, even if S A and S S are actuated (signals s 9 and s 10 ), no changes will occur. When the crown representing safety switch S L is pulled out, a negative electrical potential is applied to reset switch R and the Johnson counter circuit is actuated, to thereby actuate selecting switch S S and to advance, the Johnson counter by one count so that one of the pairs of NAND gates G 1 and G 2 , G 3 and G 4 , and G 5 and G 6 , G 7 and G 8 , or G 9 and G 10 are opened while the other four pairs of NAND gates remain closed. For example, if selecting switch S S has indexed the Johnson counter so that gates g 3 and g 4 are open, the second digits are selected, in the following manner.
Switch S S is closed thus applying a pulse (s 1 ) to all three flip-flops to actuate the same and effect an opening of NAND gates G 3 and G 4 by the generating of a 1 condition at NOR gate N 1 . The opening of NAND gates G 3 and G 4 allows signal F supplied from counter 1 to become output S b (s 2 ) of NAND gate G 4 and is therefore applied to display element L S causing the same to flicker. Since only display element L S is flickering, the operator can easily discern that the seconds digit is being corrected. Then, upon closing switch S A a pulse (s 3 ) is supplied by opened NAND gate G 3 and becomes correction signal S a (s 4 ) which is applied to the seconds counter 2 to correct the seconds time display. If it is then desired to correct the hours digit, selector switch S S is closed twice to apply two pulses (s 5 ) to the flip-flop circuits, to thereby change the state of the counter. NOR gate N 3 is opened, thus making the output thereof a 1 hence opening NAND gates G 1 and G 2 . The opening of gate G 2 allows signal F to be applied through the control circuit to the digital display element L H as signal H b to effect a flickering of said display elements. Thus, a correction signal (s 8 ) is applied by correction switch S A through gate G 1 to hours counter 4 to thereby effect correction of the hours display. It is understood that as the selection switch S L is closed, and a pulse is applied to said control circuit 12, the digit to be corrected and the flickering of such digit is effected in the following sequence; second, minute, hour, date, day of the week, and seconds again.
By the foregoing arrangement, two switches permit the selective correction of any digit of time indication, including second, minute, hour, day and date of a digital display such as a liquid crystal display or a light emitting diode display. This structure eliminates the necessity of separate switches for each digit, thereby permitting the production of a compact electronic timepice such as a wrist watch capable of displaying a wide range of information.
While in the timepiece depicted, the liquid crystal display is driven by a DC signal, an AC signal may also be utilized to drive a liquid crystal display. In such an arrangement, the digit to be corrected would be indicated by changing the driving frequency of the digit to be corrected, for example, by providing two AC driving steps, 32 Hz and 8 Hz.
It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
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A time correcting apparatus for an electronic time-piece having a digital time display including a selecting switch for selecting the digit of the display to be corrected, which digit is visually identified, and a correcting switch for correcting that digit. Time correction is achieved by the combined operation of the two switches.
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BACKGROUND OF THE INVENTION
As the years go by and the price of fuel becomes higher and higher, it becomes more important that the heat loss by convection and radiation through the windows of buildings be reduced. This is particularly true in the case of residential buildings, where there is a greater likelihood of the windows being ill-fitted and loose. In the past, it has been common practice to provide heavy, insulated drapes over large windows in homes, whereby a certain amount of radiant and convective heat loss is prevented. The ideal system is to have a dead air space between the interior and the exterior of the house in the windowspace. It has been a common but expensive practice to provide double-thickness glass in the lights of residential windows, but this still does not prevent leakage around the window and through cracks. While metal shades have the effect of reducing the radiation to and from a room (therefore preventing heat loss in the winter), they have little effect on convection loss. Various means, such as covering the interior of the window frame with a clear plastic film and cementing it in place suggest themselves, but most of these arrangements are either unsightly or are not easily removed and stored when it is desirable for aesthetic purposes and otherwise to expose the window.
These and other difficulties experienced with the prior art devices have been obviated by the apparatus disclosed in my prior U.S. Pat. No. 4,083,148 issued Apr. 11, 1978 entitled "Window Insulating Apparatus". The apparatus described in this patent consists of a plurality of panels formed of heat-insulating material arranged in side-by-side vertical planes and slidable from a side-by-side storage position at the top of the window to an operative position in which the panels are arranged in a step fashion. An extruded element is applied to the upper and lower edges of each panel, each element having a sealing surface which mates with a similar sealing surface on a similar extruded element applied to the immediately adjacent panel. A similar extruded element lies along each vertical edge of each panel, the sealing surface of each vertical extruded element engaging a similar sealing surface on an immediately-adjacent vertical extruded element.
It is a principal object of the present invention to provide an improved window insulating apparatus which has all of the advantages of the apparatus disclosed in my prior U.S. patent, supra, with improved thermal insulating properties and improved adjusting means for each of installation and compensation for wear.
Another object of this invention is the provision of improved window insulating apparatus which is simple in design, and easy to manufacture and install.
A further object of the present invention is the provision of improved window insulating apparatus comprising laminated insulating panels having superior thermal insulating properties.
It is another object of the invention to provide an optional transparent sealing means for the top window.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended thereto.
SUMMARY OF THE INVENTION
In general, the present invention consists of a window insulating apparatus consisting of a plurality of panels formed of insulating material, the sum of the areas of the panels being approximately equal to that of the window opening. An extruded element is applied to the upper and lower edges of each panel, each element having a sealing surface which mates with a sealing surface on a similar extruded element applied to the immediately-adjacent panel.
More specifically, each panel is generally rectangular and arranged with its length extending horizontally across the window. The panels arranged in spaced, parallel vertical planes and are slidable vertical from a side-by-side storage position (at the top of the window) to an operative position in which the panels are distributed in a step fashion over the entire window. A plurality of spaced, parallel vertical strips of low-heat-transfer elastomeric material are mounted on the inner side surfaces of the window frame and form grooves therebetween for guiding the vertical edges of the panels. The panels are constructed of laminations of different materials which guard against convective and radiant heat loss. One such product is manufactured by The Appropriate Technology Corporation of Brattleboro, VT and consists of a sheet of nylon between two fiberfilled layers of fabric. Another is manufactured by SECO Company of Valley Forge, PA and consists of a polystyrene foam core between layers of highly reflective white pigmented polyvinyl chloride. Means is provided for adjusting the panel guiding elements in directions parallel with the transverse to the board planes of the panels. When the invention is used with a double window, consisting of an upper and lower window, a plate of transparent material is provided between the upper sash of the lower window and the bottom of the uppermost panel to provide additional insulation without sacrificing the utilitarian function of the upper window of permitting light to enter the building.
BRIEF DESCRIPTION OF THE DRAWINGS
The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:
FIG. 1 is a perspective view of a window insulating apparatus embodying the principles of the present invention and shown in use with a window,
FIG. 2 is a front elevational view of the apparatus,
FIG. 3 is a vertical sectional view on an enlarged scale of the apparatus, taken on the line III--III of FIG. 2, and
FIG. 4 is a horizontal sectional view of a portion of the invention taken on the line IV--IV of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1, 2, and 3, wherein are best shown the general features of the invention, the window insulating apparatus, indicated generally by the reference numeral 10, is shown in use with a conventional double-hung residential window 11. The apparatus is shown as consisting of five panels 12, 13, 14, 15, and 16, the sum of whose areas is slightly more than the total area of the window opening. Each panel is generally rectangular in shape and is arranged with its long dimension extending horizontally. The panels are arranged in side-by-side planes and are slidable vertically in the window frame from an upper storage position (where panels lie side-by-side) to a lower operative position (where the panels extend from top to bottom in a step-like condition, as shown in FIG. 3).
Referring to FIGS. 2 and 3, it can be seen that the upper and lower edges of each panel are provided with an extruded element. The upper edge of the panel 12 is provided with the extruded element 17, the upper edge of the panel 13 is provided with the extruded element 18, the upper edge of the panel 14 is provided with the extruded element 19, the upper edge of the panel 15 is provided with an extruded element 20, and the upper edge of the panel 16 is provided with an extruded element 21. The extruded elements 22, 23, 24, 25, and 26 on the lower edges of each of the panels 12, 13, 14, 15, and 16, respectively, are shown in FIG. 3.
The inner sides of a pair of side frame members 28 of the casing are provided with spaced vertical grooves 30. One side frame member 28 is shown in detail in FIG. 4, the opposite member 28 being identical in every respect but of opposite hand. Vertical guide strips 32, rectangular in cross section, are located within grooves 30 and extend beyond the inside surface of side frame member 28 to form vertical grooves 34 therebetween. Strips 32 are preferably held in place by means of adhesive and are constructed of a low-heat-transfer elastomeric material, preferably of foamed plastic having the general properties of felt.
As shown in FIG. 4, the vertical ends of the panels 12-16 are guided for vertical movement within the grooves 34 and form with the strips 32 a continuous vertical wall of low heat-transfer material across the window space when the panels are in the closed position as shown in FIG. 3.
The innermost guide strip 32' extends along the inner side of side frame member 28 between the side frame member and the windows and is constructed of a material similar to that of strips 32.
Side frame members 28 are movably mounted toward and away from each other. The relative position of each side frame member is determined by first adjusting means comprising a layer of elastomeric material 36 such as rubber or foamed plastic extending between the side frame member and the adjacent vertical window casing member 37, and screws 38. The shanks of the screws 38 extend freely through bores 39 and 40 in side frame member 28 and the layer of elastomeric material 36, respectively, and are threaded into the vertical casing member 37. The heads of the screws, indicated at 41, are larger than bores 39 and extend into countersunk portions 42 of bores 39. During installation of the window insulating apparatus, the screws 38 are threaded into side casing member 37, thereby drawing side frame member 28 toward the casing member and compressing the layer of elastomeric material 36. After the panels are positioned within grooves 34, screws 38 are backed off until the side frame member 28 is positioned so as to produce the desired sliding characteristics between the panel elements and guiding elements of the frame member. The screws 38 can be backed off additional amounts to compensate for wear of the various sliding components during subsequent use of the window insulating apparatus.
As shown in FIG. 4, the guiding elements for the outermost panel 16 comprise on each side thereof a vertically-extending guide rail 44 and a plastic extrusion strip 46 fastened to the vertical edge of the outermost panel 16 and slidably mounted on guide rail 44. Extrusion member 46 is H-shaped in horizontal cross-section and comprises pairs of oppositely-directed vertical flanges 47 and 48 for straddling rail 44 and panel 16, respectively.
Each rail 44 is adjustably mounted by a second adjusting means generally indicated by the reference numeral 50, which comprises a spacer element 52 extending vertically between the rail 44 and the forward side of the side frame member 28 and adjusting screws 54, the shanks of which extend freely through apertures 55 and 56 in rail 44 and the layer 52, respectively, and are threaded into the side frame member 28. The outer members of the flanges 47 and 48 are in frictional contact with layer 52 and the amount of friction can be varied by tightening or loosening the adjusting screws 54. The remaining space between layer 52 and rail 44 not occupied by the flanges of member 46 is filled by a plastic strip 58 extending out to the vertical casing member 37. Element 46 and strip 58 are preferably made of flexible vinyl plastic material and layer 52 is preferably made of the same material as strips 32. Strip 58 is made wide enough to extend beyond the vertical window casing 37 or to fold inward toward the casing 37 as shown in FIG. 4, depending on the depth of the casing. Apertures 55 in guide rail 44 are greatly oversized to allow for additional adjustment of the rail toward and away from the edge of the front panel 16 independently of side frame member 28. In this way, the front panel 16 can always be maintained in a tight sliding relationship with its associated guide elements, so that the entire panel assembly can be maintained in the upper closed position when it is desired to do so regarless of the looseness between the remaining panels and their associated guiding elements as a result of subsequent wear. In addition, the guiding elements for the front panel function as a locating point for the entire panel structure allowing the window insulating apparatus to be properly located and to function properly, regardless of size variations of the various components due to normal manufacturing tolerances.
The panels 12-16 are laminated structures, see panel 13 in FIG. 4, comprising a central relatively rigid layer 60 and two outer layers 62. The central layer 60 is preferably made of plastic material coated on at least one side with a radiant heat-reflective material. The two outer layers 62 are preferably made of relatively soft low thermal conductive material, as for example, plastic foam having the same felt-like characteristics as guide strips 32. In this way, the panels provide protection against heat loss in the form of both convection heat and radiant heat.
Referring particularly to FIG. 3, there is shown an optional feature for providing additional insulation to the upper portion of window 11 and is generally indicated by the reference numeral 64. Optional feature 64 comprises a removable bracket 66 mounted to a stationary bracket 67 fixed to the upper sash 68 of the lower window. Bracket 66 extends rearwardly below the upper rear panel 12 and includes a horizontal groove 70 facing the bottom of panel 12. Bracket 66 has a downwardly extending lip 69 fits into a groove 71 in bracket 67. Bracket 66 will thereby be held in place on bracket 67 provided there is sufficient downward pressure on bracket 66. A plate 72 of transparent material is mounted in groove 70 and extends upwardly into a layer of elastomeric material 74 attached to the lower extruded element 22 of panel 12. Layer 74 is preferably constructed of a soft plastic foam material. Plate 72 may be made of glass or rigid clear plastic material. It is preferred that bracket 66 to be made of a flexible plastic material to enable plate 72 to be snapped into and out of position as desired. Transparent plate 72 extends between side frame members 28 within the rearmost grooves 34 with a slight clearance between the plate and the side frame members 28.
An elastomeric plastic foam pad 76 is mounted on the underside of the top casing member 77 for engagement with the upper extruded element 17 of the upper rear panel 12 and a similar elastomeric plastic foam element 78 is mounted on the lower window sill 79 for engagement with the lower extruded element 26 of the forward panel 16 when the panels are in the closed position as shown in FIG. 3.
Extruded elements 17-21 are provided with inclined lower surfaces 80 which engage upper inclined surfaces of the lower extruded elements 22-26 to interlock the panels 12-16, as shown in FIG. 3 when the panels are extended to their fully closed position. However, there is a slight clearance between each extruded element and the adjacent panel.
The operation of the invention will now be readily understood in view of the above description. In the drawings, the panels are shown as in their operative position in which the passage of heat outwardly through the window is inhibited. In this position, as is evident in FIGS. 1 and 2, the panels 12, 13, 14, 15, and 16 completely cover the window opening. When the weather is such that the heat saving features is not needed, the panels are moved up into vertical position coextensive with the panel 12 (which never moves), so that four-fifths of the window is available for the admission of light, the five panels occupying only the upper one-fifth.
As is evident in FIG. 3, when the panels are moved to their downward position, the sealing surfaces are in firm engagement. The sealing surface of the upper horizontal extruded element of the lower panel tightly engages the sealing surface of the lower extruded element of the upper panel. The first and second adjusting means maintain the panels snugly pressed against the side frame members guiding elements along the sides of the panels.
The advantages of the present invention can be readily understood in view of the above description. The present invention involves an attachment for conventional windows which can be easily applied by a homeowner, or at least applied with a minimum of labor by the employees of a business organization selling the apparatus. The device presents a pleasing appearance when in its upper stored position; most people use shades on windows and the shades are normally set at one-quarter distance at the upper part of the window in any case. In other words, it will give the appearance of a partially-drawn shade when in the storage position. When in the lower, operative position, of course, the surfaces of the panels can be decorated as appears to be necessary and even supplied with an imaginary scene of what might exist outside the window. In any case, in the operative lower position, the important criterion is the saving of heat and, particularly during the winter months, the outer appearance of the landscape is not as important as the saving heat and the expense of fuel. The size of the extruded elements and the panels on which they are fitted can, of course, be varied to suit the particular climate involved. The thickness of the insulated panel may be greater in a colder climate, but, of course, this thickness is limited by the depth of the window casing available. Furthermore, the present design lends itself very readily to sale in "kit" form in which the homeowner can cut his panels to suit his particular window size and in which the standard extruded elements can easily be cut and cemented in place. The installation of the present invention will pay for itself in a very short time. It is a positively-working shade, it reduces air draft around the lower window tracks and joints, it traps dead air for insulation purposes, and the panels provide additional insulation. Particularly, when storm windows are not closed or are loose fitting, the present invention will slow down the heat loss on colder nights. It will help to retain sunny weather heat and it acts as an indoor temperature regulator, particularly in the springtime and in fall. Also, when the apparatus is in closed or operative position, it will tend to reduce outside noise. It will lower the cost of air conditioning, not only at nighttime, but in the daytime also when in operative position, because it will reflect a degree of radiant heat from the sun. It will prevent some of the heat from entering the room and will shade the room. It is the intent of the present invention to provide a durable, adjustable construction with a minimum of friction which is intended to last for a considerable period of time and to save on the cost of heating and air conditioning in such a manner as to pay for itself in a short time. It is an attempt to approach the heat transfer coefficient, K, of an insulated exterior wall when used with storm windows and ordinary inside windows, using double-hung single glass glazing. It contemplates an installation in 10 to 15 minutes by unskilled labor and it has various built-in features for wear adjustment. The rearmost vertical guide strip contacts the lower window and allows the movement of the lower window undue wear on the inside window frame surface. The cushioned edges of the weather seal foam at the top and the bottom allow a close-fit interlock go occur between the bottom and the top edges of the panels. The guide strips at the edges of the panels provides a positive vertical tracking for all panels and allows a "light touch", even friction between the strips and panels.
It is contemplated that each guide strip 32 and spacer element 52 could be made of rigid material enclosed in a flexible vinyl sleeve having the same softness of the paneling material. The vinyl sleeve will provide protection against ultra-violet rays and moisture.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.
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Window insulating apparatus consisting of a plurality of low thermal conductivity panels slidably carried in a conventional window frame.
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BACKGROUND OF THE INVENTION
The present invention relates to a control for operation of an electrically powered lift truck.
Such lift trucks normally use hydraulically actuated rams to lift the fork carriage, to tilt the mast, and to operate a variety of attachments such as sideshifters, clamps, rotators and the like. The hydraulic system for the rams normally uses a single hydraulic pump of the fixed-displacement type driven by an electric motor using the truck battery as its power source.
The various hydraulic functions require widely differing rates of hydraulic fluid flow. The tilt and attachments require relatively low rates of flow, while the lift function requires a much higher flow rate. The tilt and attachment flow requirements have remained relatively constant over the years, whereas the lift speed has increased considerably over recent years, thus increasing the range of flow rate required for operation.
The motor and pump must, of course, be designed to supply the maximum flow required for the lift function. If the motor is connected directly across the battery, as is often the case, excess fluid flow is produced when the tilt and attachment rams are operated. The excess fluid flow has to be dumped back to the supply tank at a high relief pressure which represents a considerable waste of energy and which causes an undesirable heating of the fluid. A similar situation occurs when the lift is operated at less than full speed except that in this case the excess oil is passed back to the supply tank at system pressure.
Electronic controls have been developed for electric motors wherein the motor is connected to the battery through an electronic switch means, typically a thyristor in the form of a silicon-controlled rectifier. The switch means is repeatedly closed and opened, with the ratio of closed to open time being controllable to regulate the average voltage delivered to the motor from the battery so that the speed thereof can be controlled.
SUMMARY OF THE INVENTION
The present invention utilizes an electronic switch means to control the speed of the motor and pump, and therefore provide different rates of fluid flow in the hydraulic system of a lift truck. A signal is generated for each selected hydraulic function, the signal being used to control operation of the motor and pump so that the pump will produce the proper fluid flow for the selected function.
In more particular, a plurality of voltage dividers are provided, one for each hydraulic function. Selection of one function will cause the voltage output of one, and only one, voltage divider, namely the one associated with that function, to be applied to the motor control so that the proper speed is produced. Each voltage divider has a variable resistor therein and the voltage divider circuits are independent of each other so that the voltage outputs can be adjusted to match the motor and pump speed to the particular function that is selected.
Normally, the tilt and attachment functions can operate efficiently with constant flow at the appropriate rate. For such functions, fixedly adjustable variable resistors are used to provide constant flow at the rate required for the selected function. However, when the lift function is selected, it is desirable to have the lift speed vary in accordance with the degree of movement of the lift lever from neutral position. In order to provide such variable speed of operation, the variable resistor of the voltage divider for the lift function is coupled to the lift lever so that the pump speed can be smoothly varied as the lift lever is moved away from and back to neutral.
Other aspects of the invention are set forth in the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, forming a part of this application, and in which like parts are designated by like reference numerals throughout the same,
FIG. 1 is a generally schematic illustration of the invention;
FIG. 2 is a perspective view of the lever and variable resistor mounting;
FIG. 3 is a diagram of the motor control of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein a preferred embodiment of the invention is shown, FIG. 1 discloses a system for moving the lift forks of a lift truck in a plurality of directions. Such system includes a plurality of hydraulically operable rams 11, 12, 13 and 14 which are mounted on the lift truck in a conventional manner to cause the forks to move as desired. For example, ram 14 is usable to lift the fork carriage while ram 13 is usable to tilt the mast. Rams 11 and 12 may be used for additional functions, such as side shifters, clamps, rotators or the like. Although four rams are shown, more or less may be used depending on the number of functions desired.
The hydraulic system for ram operation includes a pump 15, driven by electric motor 16, which draws hydraulic fluid from supply tank 17 and forces it under pressure through conduit 18 to the serially connected control valves 19, 20, 21 and 22 which are used to communicate the fluid to the various rams.
Valves 19-22 are conventional, and may be in the form generally shown in the drawing. Fluid under pressure enters inlet passage 26 and passes to the lands 23b and 23c of valve spool 23. If the spool is in the illustrated neutral position the fluid will flow out through outlet passage 29. Movement of the spool upwardly causes land 23c to block outlet 29 and open a chamber 24 to inlet 26 so that pressure fluid will flow through passage 31 and conduit 32 to the head end of ram 14. Ram 14 is a single acting device, thus there is no fluid connection between valve 22 and the rod end of the ram. Movement of the spool 23 downwardly permits the head end of ram 14 to exhaust via passage 31 past land 23d to outlet passage 25. Outlet 29 is blocked at this time by land 23b, but the pump does not run when spool 23 is in this position.
Valves 19-22 are identical and are connected so that the inlet passage 26 of each valve is connected to the outlet passage 29 of the preceding valve. In this manner whenever one of the valves is actuated to cause operation of the ram associated therewith, it will cut off pump pressure to the succeeding valves so that the succeeding rams will not operate even if their spools are moved from neutral with the exception of lift ram 14 which can permit lowering of the fork carriage by gravity when spool 23 is moved to the downward or lower position. Passages 33 and 34 are used when a control valve is required to establish fluid communication with both the head and rod ends of a ram such as 11, 12, 13 which are double acting in the arrangement of FIG. 1.
Movement of spool 23 is caused by a manually operable lever 41 which extends generally radially from support shaft 42 and is pivotal about the axis of such shaft. Link 43 connects between lever 41 and spool 23 for movement of the spool in either direction from neutral upon movement of the lever 41 from its illustrated neutral position. Valves 19, 20 and 21 are similarly operated by manually operable levers 46, 47 and 48.
Spool 23 includes a projection 49 that is profiled such that an associated microswitch 54 remains unoperated in the neutral and lower positions of the spool but is operated when the lever 41 is moved in the raise direction. The spools in valve sections 19, 20, 21 include similar projections profiled such that associated microswitches 51, 52, 53 remain unoperated in the neutral positions but will be operated when respective levers 46, 47 or 48 are moved in either direction from the neutral position. Lever 41, used to control operation of the lift ram 14, also actuates variable resistor 56 which is secured to support shaft 42 in a manner and for a purpose to be hereinafter described.
Referring now to FIG. 2, support shaft 42 is journaled in bearings 57 and 58 for rotation about its axis, the bearings being integral with frame bracket 59 which is rigidly securable to the frame of the lift truck. Lever 41 is mounted on shaft 42 by means of collar 61 which is secured to the shaft, as by set screw 62, so that pivotal movement of lever 41 causes rotation of shaft 42.
Variable resistor 56 includes a housing 63 and an axially extending rotatable adjustment shaft 64. The adjustment shaft fits within the bore of support shaft 42, coaxially therewith and is rigidly secured thereto by set screw 66 for unitary rotation. Plate 67 fits onto the threaded mount 68 of the resistor housing with housing prong 69 being received in hole 70 of plate 67 so that when nut 71 is screwed into place on the mount, plate 67 will be rigidly secured to the housing and held against rotary movement relative thereto. Plate 67 is slotted to provide opposed guide surfaces 72 and 73 spaced outwardly from the axis of shaft 64. A roll pin 74 is fixed to frame bracket 59 and extends parallel to the shafts 42 and 64, and through the slot of plate 67, pin 74 having guide surfaces 76 and 77 on opposite sides thereof which are in sliding engagement with guide surfaces 72 and 73 respectively of plate 67.
The interengagement of the pin 74 and plate 67 restrains any rotative movement of resistor housing 63 about the axis of its shaft 64. As a consequence, any rotation of shaft 42, by movement of lever 41, will cause a corresponding and accurate adjustment of the resistance of the resistor. In the event of endwise movement of shaft 42, which frequently occurs, the sliding interengagement of pin 74 and plate 67 will allow the resistor housing to move in a translatory manner with the shaft 42. As a result, endwise movement of shaft 42 places no strain on the resistor and does not affect its setting. In addition, this construction eliminates any possibility of side load on the potentiometer bearings which might otherwise occur due to eccentricity between shafts 42 and 64.
Levers 46, 47 and 48 may also be mounted on support shaft 42. However, their bearing collars are not clamped to the shaft, so that pivotal movement of these levers will not cause rotative movement of shaft 42 or vice versa.
The motor control 80 of FIG. 1 is illustrated in greater detail in FIG. 3. The main power circuit includes, in series, battery 81, main contactor contacts 82, the field F and armature A of motor 16 and an electronic switch means 83 which closes and opens to control the average voltage applied to the motor and thereby control the speed of the motor. The switch means preferably comprises a thyristor 84 through which the motor current flows when the thyristor has been gated into conduction. The operation of the thyristor can be controlled in any conventional manner. As, for example, a fixed-frequency "on" oscillator 86 may be used to generate a gate pulse once for each cycle of oscillation, the gate pulse being applied to the gate of thyristor 84 to gate it into conduction. When thyristor 84 switches on, an inhibit signal supplied via conductor 119 will be removed and the "off" oscillator 88 will generate a commutating pulse at a predetermined time after the thyristor 84 switches on. The commutating pulse is used, in a conventional manner to commutate thyristor 84 and thereby disconnect motor 16 from the battery. In such a system motor control is achieved by using the signal-responsive time delay means 87 to vary the time delay between the firing and commutation in response to the magnitude of the control signal applied to the control input 89 of the time delay. In this manner the magnitude of the control signal will control the on/off ratio of thyristor conduction for each cycle of operation and will thereby control the average voltage applied to the motor.
If desired, motor voltage can also be controlled by using a variable frequency "on" oscillator and an "off" oscillator which pulses at a constant time after the gate pulse from the "on" oscillator. In such case, the "on" oscillator conventionally includes a signal-responsive circuit wherein the frequency of oscillation is varied in response to the magnitude of a control signal. The on/off ratio of conduction of the main thyristor for each cycle of oscillation will again be determined by the magnitude of the control signal.
Microswitches 51, 52, 53 and 54 are shown on FIG. 3 in their normal position, i.e., their position when the valve and lever associated therewith are in neutral position. Each microswitch has a normally-closed contact 91 and a normally open contact 92. Movement of a valve and lever from neutral position will cause the movable switch member 93 to disengage from contact 91 and close against contact 92. The switches are connected in series with each other and through key switch 94 to battery tap 96, which may be at 36 volts. Battery tap voltage is applied to the switch member 93 of microswitch 51 through the key switch 94 and is applied to the switch members 93 of succeeding switches 52, 53, 54 through the normally closed contact 91 of the preceding switch and the serial connection of the switches is in the same order as the serial connection of control valves 19-22. It should be noted that in the case of the lift lever 41, the movable switch member 93 will disengage from contact 91 and close against contact 92 only when lever 41 is moved in the lift direction. By virtue of this arrangement, closure of the normally-open contacts of any one switch will apply battery tap voltage to its contact 92, provided all of the normally-closed contacts of the preceding switches are still closed. Contrarily stated, opening of the normally-closed contacts of any one switch will prevent battery tap voltage from being applied to any succeeding switch.
Closure of key switch 94 will allow current flow through resistor 96 and zener diodes 97 and 98 so that regulated voltages, less than battery tap voltage and, for example, 11.2 and 5.6 volts, will appear at junctions 100 and 101. Current can flow from junction 100 through resistor 102, diodes 103 and 104 and resistor 105, producing a voltage at junction 106 of about 5 volts. The acceleration capacitor 107 will consequently be discharged at this time. The voltage at the junction 108 between diodes 103 and 104 controls the time delay. The 5-volt signal at junction 106 will establish a minimum on-off ratio of conduction of thyristor 84.
If one of the control valves is moved from its neutral position, e.g., valve 19, its microswitch 51 will apply battery tap voltage to its contact 92. Current may now flow through one of the isolation diodes 109 and contactor coil 111 to cause contacts 82 to close. Battery voltage is applied through conductor 120 to the "on" oscillator 86 to start it into operation.
Current also flows through resistor 113, variable resistor 114 and resistor 105. Diode 116 clamps the voltage across the voltage divider comprising resistors 114 and 105 to the 11.2 volts at junction 100. Variable resistor 114 may be fixedly adjusted so that the voltage at the junction 106 will be at any desired value between 5.6 and 11.2 volts. This signal is then applied to the signal-responsive means 87 via diode 104 so that the on-off ratio of conduction of thyristor 84 is increased to the value at which the motor 16 will drive pump 15 to supply ram 11 with hydraulic oil of the desired amount.
Acceleration capacitor 107 will charge through resistor 102 and will provide a gradual increase of the voltage at junction 108 as it rises to the value determined by the setting of variable resistor 114.
In like manner, if microswitch 52 is actuated in response to movement of valve 20 and lever 47 from neutral position, contactor coil 111 and the "on" oscillator will be energized and the voltage divider comprised of variable resistor 117 and common resistor 105 will have a regulated 11.2-volt potential clamped thereacross. This in turn will cause voltage-output junction 106 to go to a level determined by the setting of variable resistor 117, so that the motor will drive pump 15 at the proper speed to supply ram 12. Likewise, the adjustment of variable resistor 118 will determine the pump speed for supplying ram 13.
The same occurrence happens when valve 22 and lever 41 are moved from neutral position to actuate the lift ram 14. However, in this instance the variable resistor 56 forming part of the voltage divider circuit is not fixedly adjustable but instead is associated with valve 22 and handle 41 so that its resistance will vary in proportion to the magnitude of movement of valve 22 and lever 41 from neutral position. This enables the operator to control motor speed and pump flow by lever 41 with the speed and flow increasing smoothly as the lever is moved progressively further from neutral position.
The present system thus provides a simple control whereby the motor can be separately and independently set to operate at a predetermined speed for each function desired and wherein the pump speed can be smoothly and continuously varied by the operator when the lift ram is in operation. By the serial connection of the control valves and microswitches, if the operator moves two levers from neutral position at the same time, the most upstream valve will control as to which function will be performed and the microswitch associated with that valve will ensure that the motor and pump operate at the proper speed for that function.
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An electronic control for hydraulic operation of forks on a lift truck wherein in the motor and pump speed can be matched to the particular flow requirements of each hydraulic ram and wherein a smoothly variable speed of the motor and pump is obtained for operation of the lift ram by the degree of manipulation of the lift lever.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of co-pending U.S. Application Ser. No. 184,536, filed Sept. 5, 1980 now abandoned; and a continuation-in-part of U.S. Application Ser. No. 190,372, filed Sept. 24, 1980, now U.S. Pat. No. 4,374,121, which is a continuation-in-part of U.S. Application Ser. No. 74,738, filed Sept. 12, 1979, now U.S. Pat. No. 4,279,812, issued July 21, 1981.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to collagen, and more particularly, to a collagen sponge formed of natural insoluble collagen.
2. Description of the Prior Art
"Natural insoluble collagen" as used herein means and refers to collagen which cannot be dissolved in an aqueous alkaline or in any inorganic salt solution without chemical modification, and includes hides, splits and other mammalian or reptilian coverings. More particularly, "natural insoluble collagen" means and refers to the corium which is the intermediate layer of a bovine hide between the grain and the flesh sides.
In young animals there is little intermolecular and interfibrillar crosslinking which provides for some degree of solubility of the collagen. However, during the aging process both intermolecular and interfibrillar crosslinking occurs, thus making the collagen insoluble.
The use of collagen in substantially pure form has been proposed for many uses, including for burn dressings as disclosed in U.S. Pat. Nos. 3,939,831 and 3,514,518, and similar medical applications as disclosed in U.S. Pat. Nos. 3,157,524 and 3,628,974.
U.S. Pat. No. 3,637,642 is exemplary of a process for dissolving insoluble collagen and regenerating the fiber.
Further methods have been proposed for solubilizing and reconstituting collagen with the use of enzymes to sever intra and interfibrillar bonds, such as is disclosed in U.S. Pat. No. 3,034,852, and other processes have been proposed for converting collagen fibrous masses to sheet-like material, such as in U.S. Pat. Nos. 2,934,447 and 2,934,446.
Further, according to U.S. Pat. Nos. 3,939,831 and 3,742,955, medicinal dressings can be prepared from collagen having dispersed therein antibiotics and the like to aid in the healing of skin which has been burned.
Also, according to U.S. Pat. No. 3,742,955, fibrous collagen has been proposed which has hemostatic and wound binding properties. The collagen is in the form of a fluffy fibrous product which may be converted into nonwoven webs or mats by mechanical techniques.
In accordance with the present invention, a collagen sponge is provided which derives its integrity through chemical bonding of the particulate native collagen. Further, the collagen sponge in accordance with the present invention has wound healing properties and hemostatic properties.
BRIEF DESCRIPTION OF THE INVENTION
A process for preparing a coherent porous collagen sheet material is comprised of forming natural insoluble particulate collagen in substantially pure form and suspending the particulate collagen in a weak aqueous organic acid solution while maintaining the collagen in particulate form. The suspension is freeze-dried to form a coherent porous native collagen sheet material which is useful as a wound dressing, burn dressing, hemostatic sheet or the like.
DETAILED DESCRIPTION OF THE INVENTION
The natural insoluble particulate collagen in accordance with the invention is preferably derived from a bovine hide which has been dehaired by liming, degreased to produce substantially pure native insoluble collagen fibers, and granulated to a particle size of less than 1 millimeter, and preferably less than 0.5 millimeter. The degreasing and granulation can be accomplished with materials, apparatus and methods known to those skilled in the art. It is important that the final particulate native collagen used to prepare the sponge in accordance with the invention retain its crosslinkages, i.e. insolubility in water, aqueous acid, aqueous base or salt, but yet remain substantially pure so as to maintain the nonantigenic and nonallergenic characteristics recognized in the native collagen.
After forming the particulate native collagen in substantially pure form, the particulate collagen is dispersed in a weak aqueous organic acid solution. The aqueous organic acid solution contains up to about 5 percent by weight of the collagen, and preferably up to 3 percent by weight of the collagen in particulate form. The acids useful for forming the aqueous acid solution are the weak organic acids, such as acetic, citric, lactic, ascorbic, tartaric and the like. Preferably, the pH of the aqueous acid solution is adjusted to below 4 in order to obtain good particulate collagen dispersion and, in the case of ascorbic acid, a 1 percent solution is sufficient; whereas acetic or tartaric acid requires a 0.5 percent acid solution. Preferably, the pH of the aqueous solution should be about 3 to 4.
After forming the solution, the solution is frozen with a temperature reduction rate of about -18° to -24° C./hour so that the ice crystals formed are extremely small and do not sever the crosslinkages or collagen chains, thus retaining the nativity and natural insoluble characteristics of the particulate collagen. To obtain the desired rate of freezing, the collagen dispersion is placed in a freezer at -60° to -70° C.
The frozen dispersion, at an initial temperature of -60° to -70° C., is then placed in a freeze-dryer and vacuum sublimated at 10 -3 to 10 -5 torr. The freeze-drying process requires about 12 to 24 hours with a final temperature of about 30° C.
Although there is a prevention of the destruction of the chemical bonds in the collagen by freezing, there is a minor amount of cryogenic destruction. This cryogenic destruction provides locations on the collagen product for reactive and associative sites which, throughout the freeze-drying process, provides reactivity and thus binds the individual collagen fibers to each other to form the coherent sheet in accordance with the invention.
Thus, although reactive sites are formed, the collagen retains its native characteristics typically maintaining the triple helical configuration of the fibrils, with the fibrils retaining their alignment with an axial periodicity of about 640 angstroms.
Thus, the collagen sponge prepared in accordance with the invention derives its integrity from the specific freeze-drying process while maintaining its nativity.
Typically, the collagen sponge prepared in accordance with the invention has a bulk density of 0.005 to 0.0065 gr/cm 3 and is at a preferred thickness of 5 to 7 millimeters.
It must be understood that the purity and nativity of the particulate collagen used to form the dispersion must be maintained throughout the process.
The collagen sponge prepared in accordance with the present invention has substantial advantages when used for medical applications.
The collagen sponge in accordance with the invention dessicates the wound and coagulates secretions while maintaining its capillary and hydrophilic action, even after plasma and secretion incorporation. Thus, the collagen sponge behaves as a dry, nonretentive eschar allowing for quick drainage, thus providing drying of the wound through its coagulant power, yet easily removable from the wound without pain to the patient. It has been found that the collagen sponge in accordance with the invention does not adhere to the wound lining tissue, nor is the tissue negatively influenced by the collagen sponge.
Additionally, the collagen sponge is compatible with most medications, such as antibiotics and the like, so long as the pores are not clogged, and is in fact usable in combination with other dressings. Additionally, the sponge provides protection to the wound against mechanical trauma.
Because of the high degree of purity of the native collagen used to prepare the sponge and the purity of the resultant native collagen sponge, the sponge is nonallergenic and nonantigenic. Further, the collagen sponge in accordance with the invention provides a number of physical advantages since it is easily stored and handled by treating personnel while also being easily supported by the patient without the discomfort normally associated with large gauze dressings.
The process and product of the invention will be more fully described with reference to the following examples.
EXAMPLE I
Two hundred pounds of lime split bovine fresh hide were processed in a wooden drum containing 600 pounds of water at 20° C. and 6 pounds of 37 percent hydrochloric acid. After charging the splits, the water and the acid, the drum was rotated for 4 hours. This initial process was conducted in order to remove residual lime from the collagen. After deliming, the splits were washed with water for 3 hours in the wooden drum at a float of 300 percent, and the water was changed after each hour. The washed splits were then treated with a degreasing agent, and in this example, of 3 percent solution of a nonionic surfactant sold under the trade name Triton X-114. The washing of the splits was done at a float of 200 percent for 5 hours at room temperature in a wooden drum. The degreased splits were washed with water for 4 hours at room temperature at a float of 300 percent, changing water after each hour. The splits were dried by toggling in extended form so that excess grease was removed. The toggling was conducted for 16 hours at 140° F. After drying, the collagen was in relatively pure form and was immersed in an organic solvent, and in this example, petroleum ether at a float of 300 percent for 2 hours. The splits were dried and cut into square pieces of 15×15 inches. The pieces were pulverized to a particle size of 0.032 to 0.4 millimeter and the powder was extracted with petroleum ether and again dried to remove any residual oils, fats or like soluble hide constituents. The dry particulate native collagen had the following chemical analysis:
% Protein--90.7
% Salt Concentration (as NaCl)--0.2
Acidity, milliequivalents/gr.--68.7
% Hydroxyproline--10.36
pH (1% aqueous dispersion)--3.5
The physicochemical characteristics of the particulate collagen were as follows:
β/α chain ratio of collagen--34/66
Molecular weight (avg.)--140,000
Temperature range to denaturation--31.7° to 59.2° C.
EXAMPLE II
The natural insoluble collagen in particulate form prepared in accordance with Example I was dispersed in a 0.5 percent by weight aqueous solution of acetic acid. The dispersion was 3 percent by weight of the particulate collagen of Example I. The pH of the particulate collagen dispersion was about 3.5.
The collagen dispersion was charged to a tray having a thickness of 10 millimeters and dimensions of 20 centimeters by 20 centimeters.
The collagen dispersion on the tray was placed in a freezer at about -65° C. and frozen at a temperature reduction rate of -18° to -24° C./hour until it had a final temperature of -60° to -70° C. The frozen solution on the tray was placed in a freeze-dryer and a vacuum was applied thereto of 10 -3 to 10 -5 torr for 16 hours. The collagen solution had an initial temperature of -65° C. and a final temperature of 30° C. after the 16 hour vacuum sublimation process.
Thus, upon reaching the final temperature of 30° C., the collagen sponge was a coherent open-celled sheet having hemostatic properties as well as being capable of transporting wound secretion through the sponge thickness while maintaining its capillary and hydrophilic action. The collagen sponge in accordance with ExampleII had a bulk density of 0.005 gr/cm 3 and a thickness of 5 millimeters.
Although the invention has been described with reference to particular processes and particular materials, the invention is only to be limited so far as is set forth in the accompanying claims.
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A process for preparing a coherent porous collagen sheet material is comprised of forming natural insoluble particulate collagen in substantially pure form and suspending the particulate collagen in a weak aqueous organic acid solution while maintaining the collagen in particulate form. The suspension is freeze-dried to form a coherent porous native collagen sheet material which is useful as a wound dressing, burn dressing, hemostatic sheet or the like.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Continuation Application from U.S. patent application Ser. No. 11/844,746, filed Aug. 24, 2007, which is a Continuation Application from U.S. patent application Ser. No. 11/295,492 filed on Dec. 7, 2005, now U.S. Pat. No. 7,277,334, which is a Continuation Application from U.S. Pat. No. 7,042,771 filed on Sep. 22, 2004, which is a Continuation Application from U.S. patent application Ser. No. 10/337,972, now U.S. Pat. No. 6,873,568 filed on Jan. 7, 2003, which is a Continuation of Application No. PCT/CA01/00990, filed Jul. 6, 2001, which claims priority from Canadian Application Serial No. 2,313,949, filed Jul. 7, 2000, and U.S. Application Ser. No. 60/216,682, filed Jul. 7, 2000.
FIELD OF THE INVENTION
The present invention relates generally to synchronization of row and column access operations in semiconductor memory devices, and specifically to row and column access operations in a high-speed dynamic random access memory.
BACKGROUND OF THE INVENTION
Semiconductor memory integrated circuits have traditionally utilized an internal architecture defined in an array having rows and columns, with the row-column address intersections defining individual data storage locations or memory cells. Typically, these intersections are addressed through an internal address bus, and the data to be stored or read from the locations is transferred to an internal input/output bus. Groups of data storage locations are normally coupled together along word lines. Semiconductor configurations utilizing this basic architecture include dynamic random access memory (DRAM), static random access memory (SRAM), electrically programmable read only memory (EPROM), erasable EPROM (EEPROM), as well as “flash” memory.
One of the more important measures of performance for such memory devices is the total usable data bandwidth. The main type of timing delay affecting the data bandwidth is referred to as access time. Access time is defined as the delay between the arrival of new address information at the address bus and the availability of the accessed data on the input/output bus.
In order to either read data from or write data to a DRAM memory array, a number of sequential operations are performed. Initially, bit line pairs are equalized and pre-charged. Next, a selected word line is asserted in order to read out the charge state of an addressed memory cell onto the bit lines. Bit line sense amplifiers are then activated for amplifying a voltage difference across the bit line pairs to full logic levels. Column access transistors, which are typically n-channel pass transistors, are then enabled to either couple the bit line state to DRAM read data amplifiers and outputs, or to over-write the bit line state with new values from DRAM write data inputs.
In nearly all DRAM architectures, the two dimensional nature of the memory array addressing is directly accessible to the external memory controller. In asynchronous DRAM architectures, separate control signals are used for controlling the row (or x-address) and column (or y-address) access operations. In synchronous DRAM architectures, it is also possible to use separate row and column control signals as described above. Furthermore, for synchronous DRAM architectures it is possible to employ a single command path for both row and column control signals.
In these cases, bit line sense amplifier activation is usually performed as the last stage of a self-timed sequence of DRAM operations initiated by a row activation command. Column access transistors are controlled by the y-address decoding logic and are enabled by the control signals associated with individual read and write commands.
However, for both asynchronous and synchronous DRAM architectures, the ability to minimize the timing margin between bit line sensing and the enabling of the column access transistors is limited by the timing variability between the separate control paths for row access and column access operations. Even in synchronous designs, the x-address and y-address decoding logic paths are quite distinct. The timing variability between the completion of bit line sensing and the commencement of column access transistor activation comprises the sum of the variability between the x and y address decoding paths, the variability of the self-timed chain that activates the bit line sense amplifiers, and the time of flight differences in control signals. That is, the control signals arrive at a given memory array from row and column control logic located in separate regions of the memory device and therefore may have different activation timing.
In order to reduce DRAM access times and increase the rate at which read and write operations can be performed it is important to attempt to reduce the time needed for each of the previously mentioned sequential operations necessary for the functioning of a DRAM. Furthermore, equally important is the need to initiate each successive DRAM access function as soon as possible after the previous operation.
Specifically, the delay between bit line restoration and the enabling of the column activation device is critical for both correct DRAM operation and achieving low access latency. If the column access transistor is enabled too soon, the memory cell read out on to the bit lines may be corrupted. The corruption can occur directly from noise on the bit lines coupled through the column access transistors or indirectly through capacitive coupling between a bit line driven through the column access transistor and an adjacent unselected bit line. Since the data is read destructively, if it is corrupted, it cannot be retrieved. On the other hand, if the column access transistor is enabled too late, unnecessary delay is added to memory access latency. Furthermore, the equalization and pre-charge of the bit lines in preparation for a subsequent access operation may effectively be unable to proceed until the column access transistors are turned off.
Therefore, there is a need for a memory device that can initiate successive DRAM access functions with little or no unnecessary delay without corrupting memory cell data. Accordingly, it is an object of the present invention to obviate or mitigate at least some of the above mentioned disadvantages.
SUMMARY OF THE INVENTION
In accordance with an embodiment of the present invention there is provided a semiconductor memory having a Dynamic Random Access Memory (DRAM) with an array of bit line pairs, word lines, memory cells, sense amplifiers, and a sense amplifier power supply circuit for powering said sense amplifiers. The circuit comprises a word line timing pulse for activating of at least one of the word lines, a first delay circuit coupled with the word line timing pulse for delaying the word line timing pulse by a first predetermined period, and a first logic circuit for logically combining the word line timing pulse and the word line timing pulse delayed by the first delay circuit. The output of the first logic circuit provides a sense amplifier enable signal for enabling the sense amplifier power supply circuit. The circuit further comprises a second delay circuit coupled with the word line timing pulse for delaying the word line timing pulse by a second predetermined period. The circuit further comprises a second logic circuit for logically combining the word line timing pulse and the word line timing pulse delayed by the second delay circuit for providing a column select enable signal. The column select enable signal enables selected ones of a plurality of column access devices, which are activated a predetermined time period after the sense amplifier power supply circuit is enabled.
There is also provided a method for synchronizing row and column access operations in a semiconductor memory. A Dynamic Random Access Memory (DRAM) having an array of bit line pairs, word lines, memory cells, sense amplifiers, and a sense amplifier power supply circuit for powering said sense amplifiers is provided. The method comprises the steps of generating a word line timing pulse for activating of at least one of the word lines, delaying the word line timing pulse by a first predetermined time, and logically combining the word line timing pulse and the first delayed word line timing pulse for providing a sense amplifier enable signal. The sense enable signal enables the sense amplifier power supply circuit. The method further comprises the steps of delaying the word line timing pulse by a second predetermined time and logically combining the word line timing pulse and the second delayed word line timing pulse for providing a column select enable signal. The column select enable signal enables selected ones of a plurality of column access devices wherein the selected ones of a plurality of column access devices are activated a predetermined time period after the sense amplifier power supply circuit is enabled.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described by way of example only with reference to the following drawings in which:
FIG. 1 is a schematic drawing of an asynchronous DRAM architecture (prior art);
FIG. 2 is a schematic drawing of a synchronous DRAM architecture with a common command and address path (prior art);
FIG. 3 is a schematic drawing of a DRAM architecture according to an embodiment of the present invention;
FIG. 4 is a timing diagram for the DRAM architecture illustrated in the FIG. 3 ;
FIG. 5 is an alternative embodiment of the schematic diagram illustrated in FIG. 3 ; and
FIG. 6 is yet an alternate embodiment of the schematic diagram illustrated in FIG. 3 .
DETAILED DESCRIPTION
For convenience, like numerals in the description refer to like structures in the drawings. Referring to FIG. 1 , a prior art implementation of an asynchronous DRAM architecture using separate control signals for controlling the row and column access operations is shown generally by numeral 100 . All bit line pairs are (BLT and BLC) precharged and equalized prior to an active cycle. An external memory controller 102 transmits row control signals 104 to a row control logic device 106 . The external memory controller 102 sends column control signals 108 to a column control logic device 110 . The external memory controller 102 also sends an address signal 112 to both the row control logic device 106 and the column control logic device 110 .
In response to an activation signal, the row control logic device 106 asserts word line 114 via an x-address decoder in accordance with decoding of the address signal 112 . The charge state of memory cell 113 is read on to a pair of complementary bit lines 116 . A sense amplifier 115 amplifies the voltage across the bit lines 116 . The column control logic 110 then asserts column select signal 117 via a y-address decoder in accordance with decoding of the address signal 112 . The column select signal enables the column access devices (transistors) 119 . The intersection of word line 114 and bit lines 116 is an address specified by the address signal 112 . The address is to be read from the memory array datalines via a data bus sense amplifier 118 a and subsequently an output buffer 118 b or written to the memory array from port DQ via an input buffer 118 c and subsequently a write buffer 118 d.
Referring to FIG. 2 , a prior art implementation of a synchronous DRAM architecture having a single command path for both row and column access operations is illustrated generally by numeral 200 . The external memory controller 102 sends an address signal 112 and a command signal 202 to a synchronous front end 204 . The synchronous front end 204 provides the address signal 112 to a row control logic device 106 as well as a column control logic device 110 . Further, the synchronous front end 204 provides row control signal(s) 104 to the row control logic device 106 and column control signal(s) 108 to the column control logic device 110 .
The row control logic device 106 and the column control logic device 110 assert word line 114 and column select signal 117 in a similar fashion to that described above with reference to FIG. 1 . An input/output path 206 functions similarly to the input/output path 118 illustrated in FIG. 1 with the exception that input/output path 206 also contains input and output data latches 208 a and 208 b respectively for providing synchronous transfer of data. Both of the synchronous front end 204 and the latches 208 are clocked by the same clock 210 .
Both the implementations described with reference to FIG. 1 and FIG. 2 suffer from the timing uncertainty and variability between bit line sensing and column access transistor activation. One method for reducing timing uncertainty and variability between bit line sensing and column access transistor activation comprises synchronizing the two operations locally within the peripheral region of the selected memory array. By combining the activation of column access transistors with a control signal generated based on bit line sense amplifier activation, it is possible to greatly reduce the unnecessary delay between bit line sensing and column access. This allows memory access latency to be reduced and memory operations to be performed at a faster rate.
Referring to FIG. 3 , a DRAM architecture in accordance with an embodiment of the present invention is illustrated generally by numeral 300 . A word line timing pulse signal WTP is coupled to the input of a first delay element D 1 . The output of the first delay element D 1 is coupled to the input of an AND gate A 1 . The word line timing pulse WTP is a second input to the AND gate A 1 . The output of AND gate A 1 is a sense amplifier enable signal SAEN, which is the input to a bit line sense amplifier power supply circuit 302 . The bit line sense amplifier power supply circuit 302 powers the sense amplifiers 304 for amplifying the voltage across bit line pairs 306 . Power is provided by selectively coupling p-channel supply signal SAP and n-channel supply signal SAN to the positive supply voltage V DD and ground supply voltage V SS respectively during an active sensing cycle, and to bit line precharge voltage V BLP during a precharge cycle.
The output of the first delay element D 1 is further coupled to the input of a second delay element D 2 . The output of the second delay element D 2 is coupled to the input of a second AND gate A 2 . The word line timing pulse WTP is a second input to the AND gate A 2 . The output of the AND gate A 2 is a column select enable signal CSE. The CSE signal is combined with global column select signals GCSL J comprised of predecoded column address signals via AND gates 312 (only two of which are shown for simplicity) which generate local column select signals LCSL J . Local column select signals LCSL J in turn enable the appropriate column to be accessed. The word line timing pulse WTP is also coupled to an associated word line 308 via a plurality of AND gates 314 (only one of which is shown for simplicity) for enabling the appropriate word line as selected by a pre-decoded x-address.
Referring to FIG. 4 , a timing diagram for the above-described circuit is shown. The operation of the circuit will be described with reference to FIGS. 3 and 4 and will refer to a read operation although a write operation will be apparent to a person skilled in the art once the read operation has been described. In response to a rising edge of the word line timing pulse WTP, a selected word line rises, turning on the access transistor for that memory cell. The data stored in the selected cell is dumped on to the bit line and charge sharing between the cell and bit line capacitance occurs. After a delay T 1 (generated by delay element D 1 ) from receiving a rising edge of the word line timing pulse WTP, the bit line sense amplifiers 304 are enabled by the assertion of the sense amplifier enable signal SAEN. Asserting the sense amplifier enable signal SAEN causes the sense amplifier power supply circuit 302 to drive the voltage on the sense amplifier power supply rails SAP and SAN from the bit line pre-charged voltage V BLP to the positive supply voltage V DD and ground supply voltage V SS respectively. Once the sense amplifier has been enabled, the data on the bit line is amplified to full swing levels.
After a delay of T 2 (generated by the delay element D 2 ) from the assertion of the sense amplifier enable signal, the column select enable signal CSE is asserted. The column select enable signal CSE is used to qualify a set of global column select signals GCSL J generated by the y-address decode logic for local column selection. Column select signals LCSL J local to the individual DRAM array, are generated by AND-ing the column select enable CSE signal with the global column select signals GCSL J . Therefore, when the column select enable signal CSE is asserted and a global column select signal GCSL J is asserted, a corresponding local column select signal LCSL J is enabled. The local column select signal LCSL J , in turn, enables the column access transistor 310 which couples the local bit lines to the data buses. Thus, referring again to FIG. 4 , a local column select signal LCSL 1 is generated after a delay of T 1 and T 2 . The local column select signal LCSL 1 enables a first column access transistor 310 a . During a second read cycle initiated by the next rising edge of the of the word line timing pulse WTP, a second local control signal LCSL 2 is enabled after a delay of T 1 and T 2 . The second local column select signal LCSL 2 enables a second column access transistor 310 b . In the present embodiment, LCSL 2 is implied to be different to LCSL 1 for illustrative purposes although this need not be the case.
The local column select enable signal LCSL J is activated after a delay of T 1 and T 2 from the rising edge of the word line timing pulse WTP and is deactivated by the falling edge of the column select enable signal CSE. The sense amplifiers are powered by the bit line sense amplifier power supply circuit 302 after a delay of T 1 from the rising edge of the word line timing pulse WTP and are deactivated by the falling edge of the SAEN signal. The AND gates A 1 and A 2 ensure that both the sense amplifier enable signal SAEN and the column select enable signal CSE are disabled immediately in response to the falling edge of the word line timing pulse WTP. The word line 308 is enabled as long as the word line timing pulse WTP is active.
Therefore, synchronization of the enabling of column access transistors within an individual DRAM array to a predetermined time period after the activation of the bit line sense amplifiers associated with that array is achieved. It should be noted that the predetermined delay between the sense amplifiers can be selectively programmed to achieve optimum read and write performance.
Referring to FIG. 5 , an alternate embodiment to that described in FIG. 3 is illustrated generally by numeral 500 . The bit line sense amplifier power supply circuit 302 is enabled by AND-ing the timing control signal WTP with a delayed version of the timing control signal WTP, as was described in the previous embodiment. However, in the present embodiment, the column select enable signal CSE is a result of AND-ing the timing control signal WTP with the output of a comparator 502 .
The comparator 502 compares the level of either one of the p-channel or n-channel supply signals SAP and SAN respectively with a predetermined threshold voltage V SW . In FIG. 5 , the comparator compares the p-channel supply signal SAP with the threshold voltage V SW , which is set to have a value between V BLP and V DD . As soon as SAP rises above the threshold voltage V SW , the comparator asserts a corresponding output, thereby enabling the column select enable signal CSE via and gate A 2 . The column select enable signal CSE is used for enabling the column select signals (not shown) as described in the previous embodiment.
In yet an alternate embodiment, instead of receiving the p-channel supply signal SAP, the comparator receives the n-channel supply signal SAN and the threshold voltage V SW is set to a value between V BLP and V SS . Therefore, once the n-channel supply signal SAN voltage is below the predefined threshold value V SW , the output of the comparator will be such that the column select enable signal CSE is enabled. The column select enable signal CSE is used for enabling the column select signals as described in the first embodiment. Optionally, for either of the above-mentioned embodiments, a further delay element 504 may be added for providing a delay before enabling the column select enabling signal CSE.
Yet an alternate embodiment is illustrated in FIG. 6 and represented generally by numeral 600 . As in the previous embodiments, the sense amplifier enable signal SAEN is generated as a result of AND-ing the word line timing pulse WTP with a delayed version of the word line timing pulse WTP. However, in the present embodiment the column select enable signal is a result of AND-ing the word line timing pulse WTP with a delayed version of the word line timing pulse WTP. A second delay element D 3 delays the word line timing pulse WTP by a combined time delay of T 1 and T 2 . Therefore, unlike the first embodiment, the word line timing pulse WTP is presented directly at the input of the second delay element D 3 .
The time between the negation of the word line timing pulse WTP and the disabling of the bit line sense amplification power supply circuit 302 can be adjusted by inserting a delay element between the word line timing pulse WTP and the input of the AND gate A 1 . Similarly, the time between the negation of the word line timing pulse WTP and the negation of the column select enable signal CSE can be adjusted by inserting a delay element between the word line timing pulse WTP and the input of AND gate A 2 .
Since more precise control of the timing between bit line sensing and column access is achieved by all of the previous embodiments, it is also possible to initiate column access while bit line sensing is only partially complete for further accelerating read and write operations.
Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. Furthermore, the invention may be applicable to any type of electronic memory organized in array and addressed using distinct and sequential x and y addressing phases. These include SRAM and various non-volatile memories such EPROM, EEPROM, flash EPROM, and FRAM.
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A circuit for synchronizing row and column access operations in a semiconductor memory having an array of bit line pairs, word lines, memory cells, sense amplifiers, and a sense amplifier power supply circuit for powering the sense amplifiers, the circuit comprising, a first delay circuit for delaying a word line timing pulse by a first predetermined period, a first logic circuit for logically combining the word line timing pulse and the delayed word line timing pulse to produce a sense amplifier enable signal, for enabling a sense amplifier power supply circuit, a second delay circuit for delaying the word line timing pulse by a second predetermined period, and a second logic circuit for logically combining the word line timing pulse and the second delayed word line timing pulse to produce a column select enable signal, for enabling selected ones of a plurality of column access devices wherein the second predetermined time period is selected so that ones of a plurality of column access devices are activated after the sense amplifier power supply circuit is enabled.
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[0001] This application claims the benefit of the Korean Application No. P2001-0058017 filed on Sep. 19, 2001, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a washing and drying machine and a method for controlling the same, and more particularly to a washing and drying machine and a method for controlling a drying process thereof, which can minimize cause of environmental problem while a drying performance is improved.
[0004] 2. Background of the Related Art
[0005] Of the washing machine, removing contaminants from laundry by applying an energy, such as impact and the like, there are a pulsator type washing machine, a drum type washing machine, and an agitator type washing machine depending on a type of energy application to the laundry. That is, the washing is done by applying impacts to the laundry by means of a pulsator, or an agitator, or by dropping the laundry by rotating a drum. Moreover, an action of detergent is added thereto, to make the washing done.
[0006] In general, the foregoing washing machines only have a washing function for washing laundry, such as clothes, to require taking out the laundry from the washing machine and drying under the sun.
[0007] Recently, owing to the wide spread apartment living, and change of living patterns, artificial fast drying of washed laundry is required, and to meet such a requirement, dryers are developed. The development of dryer facilitates convenient, and fast dry of the washed laundry.
[0008] However, in general, since the dryer has a size similar to the washing machine, installation of the washing machine and the dryer separately requires much space, and inconvenient in that the laundry, once washed, is required to be taken out of the washing machine and put into the dryer, again.
[0009] According to this, development of a washing machine having a drying function has been required. Eventually, in a drum type washing machine, a washing machine having a drying function is suggested, in which the laundry is dried in the drum in situ without transferring the laundry after completion of washing. However, the pulsator type or the agitator type washing machine, which in general has a better washing performance, has had no drying function. Accordingly, development of a pulsator type washing machine with a good washing performance and a drying function has been required.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention is directed to a washing and drying machine and a method for controlling a drying process thereof that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
[0011] An object of the present invention is to provide a pulsator type washing and drying machine which can wash and dry laundry.
[0012] Another object of the present invention is to provide a method for controlling a drying process of a washing and drying machine, which can improve a drying function and reduce occurrence of environmental problem.
[0013] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0014] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the method for controlling a drying process of a washing and drying machine includes a preheating step for tightly closing and heating an inner tub for preparing an environment favorable for vaporization of water by elevating a temperature of the inner tub within a short time period, and a drying step for supplying heated air to the inner tub, to make heat exchange between the heated air and laundry, for drying the laundry.
[0015] Preferably, the washing and drying machine includes a circulation duct for circulating air in the inner tub, a drain duct for draining washing water in the inner tub, and an air discharge duct for discharging excessively humid air in the inner tub, and the drying step includes a circulating type drying step for closing the drain duct to circulate the air from the inner tub to the inner tub again to dry laundry, and, on the same time, removing water vapor contained in the circulating air.
[0016] Preferably, the drying step further includes an excessively humid air discharge step for discharging a portion of the excessively humid air from the inner tub to outside through the air discharge duct at fixed intervals. Preferably, the excessively humid air discharge step includes the step of dropping a temperature and a humidity of the excessively humid air to be discharged.
[0017] Preferably, the drying step further includes a condensed water draining step for opening the drain duct at fixed intervals for draining condensed water produced in the drying step to outside.
[0018] Preferably, the drying step further includes an air discharge drying step for receiving external air through the circulation duct, and discharging the received air to outside of the washing machine through the inner tub directly.
[0019] The preheating step preferably includes a low speed rotating step for rotating the inner tub at a low speed, a high speed rotating step for rotating the inner tub at a high speed, and a stirring step for rotating the inner tub, periodically. The high speed rotating step more preferably includes the step of opening the drain duct.
[0020] The drying step includes the steps of circulating a portion of air from the inner tub to the inner tub again for drying the laundry, and discharging a portion of the air in the inner tub to an outside of the washing machine.
[0021] The air to be discharge to an outside of the washing machine is preferably subjected to regulation of a temperature and a humidity thereof. The regulation of a temperature and a humidity is preferably made by using external air introduced thereto, and the regulation of a temperature and a humidity is more preferably made by using cooling water introduced thereto.
[0022] Preferably, the drying step further includes an air discharge drying step for receiving external air, and discharging the received air to outside of the washing machine through the inner tub, directly. Preferably, no air is heated in the air discharge drying step.
[0023] The preheating step preferably includes a low speed rotating step for rotating the inner tub at a low speed, a high speed rotating step for rotating the inner tub at a high speed, and a stirring step for rotating the inner tub, periodically. The high speed rotating step more preferably includes the step of opening the drain duct.
[0024] In another aspect of the present invention, there is provided a washing and drying machine of a pulsator type including a drain duct connected to an underside of an outer tub, a circulation duct having one end positioned in the vicinity of an upper part of the outer tub, and the other end connected to the drain duct, a heater fitted to a predetermined location of the circulation duct for heating air flowing through the circulating duct, an air discharge duct having one end located in the vicinity of the upper part of the outer tub, and the other end connected to the drain duct, a fan fitted to a predetermined location of the air discharge duct for forced circulation of air, and temperature/humidity regulating means fitted to the air discharge duct for regulating temperature/humidity of the air flowing through the air discharge duct.
[0025] Thus, the present invention can improve a drying performance, and minimize an influence to an external environment.
[0026] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention:
[0028] In the drawings:
[0029] [0029]FIG. 1 illustrates a section of a washing and drying machine in accordance with a preferred embodiment of the present invention, schematically;
[0030] FIGS. 2 A- 2 C illustrate graphs showing a principle of a method for controlling a drying process of a washing and drying machine of the present invention;
[0031] [0031]FIG. 3 illustrates a graph showing a principle of a method for controlling a drying process of a washing and drying machine in accordance with a preferred embodiment of the present invention;
[0032] [0032]FIG. 4 illustrates a section of a washing and drying machine in accordance with another preferred embodiment of the present invention, schematically;
[0033] [0033]FIG. 5 illustrate a graph showing an exemplary method for controlling a drying process of a washing and drying machine in FIG. 4; and
[0034] [0034]FIG. 6 illustrates a graph showing a pre-heating step in a drying process of a washing and drying machine of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The washing and drying machine will be explained, with reference to FIG. 1.
[0036] At first, components for washing laundry will be explained.
[0037] There are an outer tub 3 inside of a washing machine case 1 for storage of washing water, an inner tub 5 having a plurality of through holes 5 a rotatably fitted inside of the outer tub 3 , and a pulsator 7 rotatably fitted inside of the inner tub 5 . The inner tub 5 and the pulsator 7 are rotated by driving means 9 fitted to a bottom of the outer tub 3 .
[0038] In the meantime, there is a water supply valve 10 in an upper part of the case 1 for supplying water for washing and rinsing, to which a water supply duct (not shown) for supplying water to the inner tub 5 is connected. There is a drain duct 11 connected to an underside of the outer tub 3 for draining dirty water to an outside of the washing machine after washing is finished. There is a drain valve 13 fitted to the drain duct 11 . An unexplained reference symbol 1 a denotes a washing machine cover.
[0039] Next, components for drying the laundry will be explained.
[0040] There is a circulation duct 20 between an upper part and a lower part of the outer tub 3 for supplying heated air into the inner tub 5 for drying laundry. Of course, there are a heater 15 for heating air, and a blower 22 for forced circulation of the air, fitted to the circulation duct 20 .
[0041] In the meantime, there is a closable inner cover 3 an air tightly fitted to a top of the outer tub 3 for prevention of air leakage. It is preferable that a fore end of the circulation duct 20 is connected to the inner cover 3 a , and a lower end of the circulation duct 20 is connected to a side surface of the outer tub 3 . Of course, the lower end of the circulation duct 20 may be connected to an underside of the outer tub 3 , when it is preferable that a connection duct (not shown) is fitted between a lower part of the circulation duct 20 and the drain duct 11 for smooth flow of water condensed from the circulation duct 20 to the drain duct 11 .
[0042] There are a first external air duct 30 connected to the circulation duct 20 for supplying external air, and a first external air fan 32 at an inlet of the first external air duct 30 for generating a suction force for drawing external air, and a suction valve 34 fitted to the first external air duct 30 for cutting off air flow, selectively.
[0043] Since the air discharged to the circulation duct 20 after drying the laundry in the inner tub 5 is hot and humid, it is preferable that the moist contained in the air is removed because circulation of such hot and humid air as it is drops a drying efficiency. Therefore, it is preferable that there is dehumidifying means fitted to the circulation duct 20 . As the dehumidifying means, there may be an air cooling type dehumidifying means in which cooling fins are fitted to an outer surface of the circulation duct 20 for removal of the moist, or water cooling type dehumidifying means in which cooling water is supplied to the circulation duct 20 for removal of the moist. Or alternatively, the external air from the first external air fan 32 is supplied to the circulation duct 20 , for heat exchange between the external air at a relatively low temperature and the hot and humid circulation air, for removal of the moist.
[0044] For smooth dry, it is preferable that a portion of excessively humid vapor formed at a top part of the inner tub 5 is discharged. Accordingly, to do this, there is an air discharge duct 40 fitted to the top part of the outer tub 3 . That is, one end of the air discharge duct 40 is connected to the inner cover 3 a , and the other end of the air discharge duct 40 is preferably connected to the drain duct 11 , though the other end may be opened to the air, directly. In this instance, the air discharge duct 40 also serves as a drain for discharging overflowing washing water during washing.
[0045] Moreover, since it is not desirable that the excessively humid air is discharged to the air as it is through the air discharge duct 40 , a temperature and a humidity of the excessively humid air are dropped to some extents before the excessively humid air is discharged to the air. Accordingly, there is a second external air duct 50 connected to the air discharge duct 40 for drawing in external air, preferably with a second external air fan 52 fitted to an inlet to the second external air duct 50 .
[0046] Also, in view of a structure, though only a portion of the air flows from the inner tub to the air discharge duct 40 if the first external air fan 32 is not operative, a supplementary valve 41 may be fitted to the air discharge duct 40 for perfect open/close of the air discharge duct 40 , if necessary.
[0047] The operation of the foregoing washing and drying machine will be explained, briefly. At first, a washing process will be explained.
[0048] The washing process is identical to the related art washing machine, actually. That is, washing, rinsing, and spinning are carried out in succession, for washing the laundry. Upon completion of the washing and spinning, a drying process is started.
[0049] In the drying process, the heater 15 and the blower 22 are put into operation, to heat air and supply to the inner tub 5 . The heated air 5 introduced into the inner tub 5 makes heat exchange with the laundry, to dry the laundry.
[0050] The drying process will be explained in detail with reference to FIG. 1.
[0051] The drying process is a step in which the heater 15 and the blower 22 are put into operation, to supply heated air to the inner tub 5 for drying the laundry, actually. There may be a variety of drying processes, which will be explained.
[0052] A method may be used, in which ducts connected to the outer tub 3 are left open actually, and heated air is supplied to the inner tub 5 . (hereafter called as “exhaust type drying”). That is, in the exhaust type drying, the suction valve 34 and the drain valve 13 are opened, to open the first external air duct 30 and the drain duct 11 respectively, and the first external air fan 32 fitted to the first external air duct 30 is driven, for supplying the heated air to the inner tub 5 . This type has a problem of causing an environmental problem since high temperature, and highly humid air is discharged to outside of the washing machine as it is.
[0053] Next, a method may be used; in which heated air is circulated to the inner tub 5 through the circulation duct 20 , continuously (circulation type drying). That is, in the circulation type drying, the first external air duct 30 and the drain duct 11 are closed, in the air circulation. It is preferable that air is removed therefrom, appropriately. Though this type of drying method can reduce the environmental problem to some extent, this type of drying method has a slow drying speed.
[0054] Next, a method may be taken into consideration, in which the circulation type drying and the exhaust type drying are mixed in a sequence. That is, the drying process period is divided, to progress the circulation type drying at first, and the exhaust type drying at the next. Though this type of drying method can reduce the environmental problem, this type of drying method has a disadvantage of a slow drying rate as before because the circulation type drying that has a low drying rate is employed in a period the drying efficiency is the best.
[0055] A method for controlling a drying process in accordance with a preferred embodiment of the present invention will be explained, with reference to FIG. 3.
[0056] The drying process in accordance with a preferred embodiment of the present invention includes an aging step and a drying step in which the laundry is dried. It is preferable that, in the drying step, a mixed type drying is employed in which other drying methods are mixed with the circulation type drying method.
[0057] The aging step is a step in which the inner tub 5 is substantially enclosed and heated for elevating an inner tub 5 temperature and a laundry temperature in the inner tub 5 within a short time period. The aging step provides an environment favorable for evaporation of water vapor at actual starting the drying step because the elevated laundry and inner tub 5 temperatures cause greater amounts of evaporation and inner saturation vapor.
[0058] In the mixed type drying, the drying is substantially progressed by the circulation type drying, but a process for discharging excessively humid vapor and a process for discharging condensed water are carried out during the drying at fixed intervals.
[0059] In detail, the first external air duct 30 and the drain duct 11 are closed, for circulating air in the inner tub 5 to the inner tub 5 again, for drying the laundry, and, on the same time, the vapor is removed from the circulating air.
[0060] That is, the circulating type drying is carried out substantially, except that the process for discharging excessively humid air is carried out in which the first external air duct 30 is opened, and the drain duct 11 is closed, at fixed intervals during the circulation type drying, for discharging a portion of excessively humid air in the inner tub 5 through the air discharge duct 40 . It is preferable that the process for discharging excessively humid air is carried out at 3-10 minute intervals for approx. 30-60 seconds. It is more preferable that the second external air fan 52 is put into operation during the process for discharging excessively humid air, for introducing external air into the air discharge duct 40 , for causing heat exchange between the external air and the excessively humid air, to drop a temperature and a humidity of the discharged excessively humid air.
[0061] The water vapor in the air introduced into the circulation duct 20 is removed by means of an appropriate humidity removing means, to form condensed water. Therefore, a process for draining condensed water is carried out in which the drain duct 11 is opened at fixed intervals, for draining the condensed water formed in the drying step. It is preferable that the process for draining condensed water is carried out at 10-15 minute intervals for approx. 10-30 seconds.
[0062] In the meantime, after the mixed type drying is finished, it is preferable that the exhaust type drying is carried out. That is, the first external air duct 30 and the drain duct 11 are opened, and the first external air fan 32 is put into operation.
[0063] A washing and drying machine in accordance with another preferred embodiment of the present invention will be explained, with reference to FIG. 4. In explaining this embodiment, parts the same with the foregoing embodiment will be given the same names and reference symbols, and detailed explanation of which will be omitted. The washing and drying machine of this embodiment is the same with the foregoing embodiment washing and drying machine, substantially. Differences of this embodiment from the foregoing embodiment will be explained.
[0064] The circulation duct 20 is connected to the drain duct 11 , directly. It is preferable that the drain valve 13 a is fitted to a location in rear of a part the circulation duct 20 and the drain duct 11 are crossed. The first external duct in the foregoing embodiment may not be provided. It is preferable that an air circulation valve 41 a is fitted to the drain duct 40 .
[0065] In the foregoing embodiment, the temperature and humidity of the high temperature, and highly humid vapor is regulated by air cooling method before being discharged to outside. That is, external air is received, and heat exchange between the received external air and the water vapor is made, for regulating the temperature and humidity of the discharged air. In the present embodiment, water cooling and air cooling are combined for a more effective regulation of the temperature and the humidity of the discharged water vapor. Of course, water cooling may only be employed. In detail, there is a water cooling valve 60 at a top of the air discharge duct 40 for selective regulation of water supply. Of course, it is preferable that the water cooling valve 60 is connected to the water supply valve 10 . Though the water cooling valve 60 may be connected to the air discharge duct 40 directly, it is preferable that a separate water cooling duct 62 is provided, and the water cooling valve 60 is connected to the water cooling duct 62 . That is, one end of the water cooling duct 62 is connected to a lower part of the outer tub, and the other end of the water cooling duct 62 is connected to the air discharge duct 40 . it is more preferable that a filter 70 is fitted to a connection part of the air discharge duct 40 and the water cooling duct 62 .
[0066] In the meantime, it is preferable that a fan 22 a is fitted to the air discharge duct 40 for smooth discharge of water vapor. If the circulation duct 20 is directly connected to the drain duct 11 the same as this embodiment, no fan may be fitted to the circulation duct 20 , because the air in the inner tub can be circulated through the circulation duct 20 even if the fan 22 a is fitted only to the air discharge duct 40 as the circulation duct 20 is connected to the air discharge duct 40 through the drain duct 11 .
[0067] A method for controlling a drying process of a washing and drying machine in accordance with a preferred embodiment of the present invention will be explained, with reference to FIGS. 4 to 6 . The drying process includes a preheating step and a drying step.
[0068] Referring to FIG. 6, the preheating step will be explained in more detail.
[0069] As explained, the preheating step is a step for elevating a temperature of the inner tub 5 within a short time period in an initial stage of the drying process. Therefore, it is preferable that the inner tub 5 is rotated at an appropriate speed in the preheating step. That is, in an initial stage of the preheating, the inner tub 5 is rotated at a slow speed for a time period P 1 , and, next, the inner tub 5 is rotated at a fast speed P 2 for a time period. Then, stopping and rotating of the inner tub 5 is repeated, for stirring the laundry P 3 . As explained in the foregoing embodiment, it is preferable that all valves are turned off actually for minimizing heat loss in the preheating step. For an example, in this embodiment, the air circulation valve 41 a and the water cooling valve 60 are turned off in the preheating step. However, though the drain valve 13 a may be turned off, since there may be water from the laundry in the step the inner tub 5 rotates at a fast speed, it is preferable that the drain valve 13 a is turned on for draining the water from the laundry to outside of the washing machine.
[0070] Next, the drying step will be explained.
[0071] The drying step in this embodiment may also employ the mixed type drying explained in the foregoing embodiment. That is, in the mixed type drying, though the drying is actually carried out by the circulation type drying, excessively humid vapor is discharged to outside at fixed intervals, and the condensed water may also be discharged during drying.
[0072] However, in this embodiment, the foregoing mixed type drying is varied slightly. In detail, in the drying step, a portion of air heat exchanged with the laundry in the inner tub 5 is circulated through the inner tub 5 again, for drying the laundry, and a portion of the air in the inner tub 5 is discharged to outside of the washing machine. That is, in this embodiment, since, of the air heat exchanged with the laundry in the inner tub 5 , a portion is circulated, and a portion is discharged, it is preferable that the drain valve 13 a is opened in the drying step. Of course, a separate discharge air passage may be provided, to open the passage while the drain valve 13 a is turned off.
[0073] In the meantime, it is preferable that a temperature and a humidity of the air discharged to an outside are regulated, appropriately. The regulation of the temperature and the humidity of the air may be made by means of appropriate temperature/humidity regulating means. Air cooling, or water cooling may be used, or the air cooling and the water cooling may be carried out in parallel.
[0074] In this embodiment, the air circulation valve 41 a is turned on/off periodically, so that the excessively humid air is discharged to outside with the temperature and the humidity regulated. For more effective regulation of the temperature and humidity of the excessively humid air, the water cooling valve 60 is turned on/off periodically. The turn on/off period of the water cooling valve 60 may be made to be the same with the turn on/off period of the air circulation valve 41 a , it is preferable that the air circulation valve 41 a and the water circulation valve 60 are opened on the same time only in a period the temperature and the humidity of the discharge vapor are high. Therefore, it is preferable that only the air circulation valve 41 a is opened in a certain period T 1 , for regulating the temperature/humidity of the air discharged to outside by the air cooling method, and the air circulation valve 41 a and the water cooling valve 60 are opened in a certain period T 2 , for regulating the temperature/humidity of the air discharged to outside more effectively by the air cooling method and the water cooling method.
[0075] In the meantime, it is required that condensed water formed in the process the temperature and humidity of the air discharged to outside are regulated is drained to outside of the washing machine. That is, it is required that the drain valve 13 a is opened appropriately, for draining the condensed water to outside through the drain duct 11 . Though intermittent opening of the drain valve 13 a is possible, it is preferable that the drain valve 13 a is opened, continuously.
[0076] In the meantime, it is preferable that all valves are opened in an end stage of the drying process, i.e., in the air discharging drying step, to discharge air in the inner tub 5 to outside. In this time, it is more preferable that the heater 15 is not put into operation.
[0077] The method for controlling a drying process of a washing and drying machine of the present invention is applicable, not limited to the washing and drying machine explained in the specification, but to other washing and drying machine.
[0078] The method for controlling a drying process of a washing and drying machine of the present invention has the following advantages.
[0079] Advantages of the method for controlling a drying process of a washing and drying machine of the present invention will be explained.
[0080] The preheating of the laundry and the inner tub before a drying process is started improves a drying performance. Moreover, the taking of an optimum drying step permits to speed up the drying, and the discharge of water vapor to outside in a state a temperature/a humidity thereof are dropped reduces environmental problems.
[0081] It will be apparent to those skilled in the art that various modifications and variations can be made in the washing and drying machine and a method for controlling a drying process thereof of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Method for controlling a drying process of a washing and drying machine including a preheating step for tightly closing and heating an inner tub for preparing an environment favorable for vaporization of water by elevating a temperature of the inner tub within a short time period, and a drying step for supplying heated air to the inner tub, to make heat exchange between the heated air and laundry, for drying the laundry, whereby improving a drying performance and reducing occurrence of environmental problem.
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TECHNICAL FIELD
This invention is concerned with the measurement of one or more of the physical characteristics, attributes and/or properties of semiconductor materials in real time as they are grown, such measurement commonly currently being conducted using a technique known as in-situ reflectometry.
More specifically, the invention is concerned with the improvement of in-situ reflectometry techniques as they are applied to the measurement of Ga—N and Ga—Al —N semiconductor materials which have recently been more widely adopted in the semiconductor industry. However, those skilled in the art will appreciate that this invention is not restricted to such semiconductor materials, and indeed the invention may have application beyond traditional and more modern semiconductor materials. Moreover, from the following, it will be appreciated that the invention may improve in-situ reflectometry for any material which may be grown using any of a number of deposition techniques, such as Chemical Vapour Deposition (CVD), Metal Organic Vapour Phase Epitaxy (MOVPE), Molecular Beam Epitaxy (MBE) and the like.
BACKGROUND OF THE INVENTION
A modern reflectometry technique is usefully described in an article entitled “In-Situ Characterization During MOVPE Growth of III-Nitrides using Reflectometry” by Christoph Kirchner and Matthias Seyboth, working in the Department of Optoelectronics in the University of Ulm.
In this article, the authors describe an in-situ reflectometry technique during low pressure Metal Organic Vapor Phase Epitaxy (MOVPE) growth of GaN using a commercial fiber reflectometer.
Nitride based materials comprise today's fastest developing III-V compound semiconductor (In—Al—G a—N) technology. Excellent optical and electrical properties, a wide and direct bandgap in combination with high thermal, mechanical, and chemical robustness make GaN and its alloys a well suited material system for optoelectronic devices in the UV to visible frequency range (e.g. light emitting diodes (LEDs), laser, photodetectors).
Successful epitaxial growth of such multilayered device structures requires precise control of the growth parameters (temperatures, flows, pressures) to achieve reproducible results. In particular, the heteroepitaxial GaN growth on highly mismatched substrates requires a two-step growth process consisting of
i. nucleation at low temperature to provide a nucleation semiconductor layer and annealing this layer, and then ii. subsequent semiconductor growth to achieve high quality epitaxial GaN layers.
Deposition and subsequent annealing of the nucleation layer is a critical, highly sensitive process, and reproducibility is a pervasive problem due to the fact that small variations of substrate temperature and slightly different morphologies of the sapphires of which the substrates are commonly constituted strongly influence properties of the nucleation layer and subsequent GaN growth. In-situ characterization methods would therefore be very helpful in controlling the initial growth stages of GaN as this could result in a more uniform, less flawed and more consistent semi-conductor material.
It is worth mentioning that one real-time semiconductor property characterization method in current use is known as reflection high electron energy deflection (RHEED), and this method is widely used in molecular beam epitaxy (MBE) to control two-dimensional growth, growth rates and composition of ternary layers. However, CVD does not involve high vacuum conditions and therefore RHEED cannot be applied.
In gas phase epitaxy (GPE) processes, or other semiconductor layering, deposition and growth techniques which are conducted in aggressive environments, in-situ reflectometry can provide similar access to the growth process.
The most common methods of growing GaN and like semiconductors is a process known as Gas Phase Epitaxy (GPE) or MOVPE, and such process is most commonly carried out using a piece of apparatus known as a reactor. Such reactors are manufactured by companies like Aixtron, Veeco, and EMF Limited. A specific example of a reactor, and one which is currently popular in the industry is an Aixtron AIX 200 RF. Essentially, the reactor is a horizontally orientated cylindrical chamber through which gas vapour is allowed to flow and which is radio-frequency heated and comprises a water cooled quartz reaction chamber operated at low pressure. Typically, Trimethylgallium (TMGa), Trimethylindium (TMIn), Trimethylaluminum (TMAl) and ammonia are used as group III and group V precursors respectively and these are caused to pass over a substrate material, which is commonly sapphire (Al 2 O 3 ).
Referring firstly to FIG. 1 provided herewith, the MOVPE system was equipped with a commercially available reflectometer schematically indicated at 2 consisting of a white light source 4 and a CCD spectrometer 6 (Filmetrics F 30). The spectrometer is a 512-element photodiode array with a spectral range of 400 nm-1100 nm and a resolution of 2 nm. The spectrometer is controlled by a computer 8 and the spectrometer software allows calculation of semiconductor physical characteristics such as deposition rate, the refractive index n, the extinction coefficient k and reflectivity. For these purposes, material data libraries are contained in the software.
As will be appreciated from FIG. 1 , an optical access to the substrate with the nitride layer growing thereon in the MOVPE reactor is mandatory.
Accordingly, the reactor 10 comprises a liner tube 12 made of quartz glass. To the outside of the reactor, there is provided a water-cooled jacket 14 , and to the outside of said jacket there is provided a radio-frequency heating coil 16 which acts to direct high intensity RF energy onto a susceptor 18 on top of which is positioned a substrate 20 which is most commonly made of sapphire. During use, a source of mixed metal organic gases passes into the chamber through an inlet 22 and as a result of the controlled conditions within the reactor and the composition of the inlet gas, semiconductor material begins firstly to nucleate on the substrate, and subsequently grow thereon. A source of purging gas is also provided which flows around the liner tube and whose flow ultimately aids in the expulsion of the metal organic gas stream from the reactor in general. It is to be understood that the nature of the gaseous flows used in such reactors is often exceptionally toxic to humans, and that great care must be taken in how such gases are handled.
In use, due to the horizontal configuration of the reactor, the ceiling of the liner gets coated with Nitride deposits during semiconductor growth, rendering it opaque to at least some extent. Therefore, a 5 mm diameter hole is drilled in the liner ceiling. The liner is located inside a quartz cylinder (outer reactor tube), which is surrounded by the water cooling jacket made of quartz, too. The reflectometer is mounted directly above the zenith of the usually cylindrical liner in which the hole is drilled so that, except for variations in the surface profile of the semiconductor, light incident thereon from the reflectometer is reflected directly back towards the source of the light as generally indicated at 26 . Both the incident and reflected light has to pass through all the quartz walls and the cooling water. Disturbing reflections from the quartz walls can be eliminated by reference measurements as in generally the oscillatory characteristics of the quartz is not affected by reaction conditions.
The spectrometer and the light source are connected to the lens system 28 by optical fibers of a coaxial type, outer strands of which are intended to carry reflected light back to the spectrometer, and the inner strands of which are intended to carry white light from the white light source of the reflectometer. The reflectance of the sample surface, recorded during the growth process, is continuously monitored and recorded. After loading the substrate into the reactor, substrates are typically heated up to 950° C. under a steady flow of a nitrogen/hydrogen mixture. Following this sapphire surface cleaning step, the substrate temperature is lowered to 520° C. for the deposition of the low temperature nucleation layer. After the nucleation layer is deposited, reactor temperature is increased to 1050° C. for growth of undoped bulk GaN.
Reflectance profiles obtained with the above mentioned setup from MOVPE GaN growth processes on sapphire are shown in FIG. 2 . The two curves were recorded during GaN growth on sapphire substrates with slightly different polishing delivered from different manufacturers. The deposition of the nucleation layer causes the first increase in reflectivity. During the following annealing step, while the polycrystalline nucleation layer is partially crystallizing, the reflection increases slightly and then drops. At this point the main GaN layer growth is started, revealing small oscillations with increasing amplitude due to decreasing surface roughness. In spite of the fact, that all growth parameters were kept constant, in the initial stages of GaN growth, the course of oscillations amplitudes in the two curves is totally different. While in the upper curve, the maximum amplitude is reached after two oscillations, the lower curve reaches maximum after four oscillations. This confirms, that heteroepitaxial GaN growth processes are very sensitive against every small variation of sapphire substrate properties. Development of the surface morphology is indicated by the course of amplitudes in the reflectance spectrum. After a few oscillation periods, the growth conditions are stabilized. The shown oscillations of the GaN growth correspond to a growth rate of 2 μm/hr. The thickness of the GaN which is grown during one oscillation can be approximately calculated using the following equation:
D GaN [nm]=λ m /2 n
where λ m is the measuring wavelength of the spectrometer in nm and n is the refractive index of GaN at the measuring wavelength. The oscillations are resonances of the layer system, where the resonator is formed by the GaN layer and the refractive index steps of the transitions GaN/sapphire and GaN/gas phase, respectively. In FIG. 2 , one oscillation corresponds to a GaN layer thickness of around 118 nm, according to the above equation. The refractive index of GaN at the spectrometer wavelength of 580 nm is 2.45 and does not change much with temperature. Thus the values for thickness calculated during growth (hot substrate) agree well with data measured at room temperature using Scanning Electron Microscopy (SEM).
During ternary layer growth (InGaN, AlGaN), prereactions in the reactor between the different group III molecules and ammonia can occur, strongly affecting growth rates and composition. The intensity of the prereactions is dependent on pressure and temperature in the reactor during growth and the type and amount of group III molecules (e. g. TMGa, TEGa, TMAl). In-situ reflectometry provides direct information on any change of growth parameters (pressure, temperature, fluxes) affecting either growth rate (change of oscillation width) and/or surface roughness (change of oscillation amplitude).
Other technical articles, specifically one mentioning one of the inventors herefor, namely that published in the Journal of Crystal Growth 248 (2003) 533-536, clearly demonstrate the strong interaction between growth conditions, the substrate surface preparation, and the physical properties of GaN epilayers.
It is also to be noted that other characterisation methods for determining physical properties of semiconductors are available, such as transmission or scanning electron microscopy (T/SEM), high resolution X-ray diffraction (HR-XRD), photoluminescence (PL) and capacitance-voltage (C-V), but such are not suited or indeed impossible to conduct in real-time during the semi-conductor growth process due to the aggressive ambient conditions within the reactor.
There are a number of difficulties associated with the above described in-situ reflectometry technique. Firstly, the coaxial structure of the coaxial fiber optic cable used in the reflectometer, necessitates expensive focussing and light reception optics.
Secondly, the operating temperature of the reactor is commonly in excess of 1000° C., and to ensure that the water does not boil in the cooling jacket, it must be pumped therefore at a sufficient flow rate so that the heat of the reactor can be safely transmitted to the water and thus removed. The difficulty with this is arrangement is that the pumping of water through an essentially annular passageway at a substantial flow rate and pressure necessarily causes some degree of turbulence in the fluid. As a result, the effective refractive index of the fluid through which both the incident and reflected light must pass is slightly altered. It is also to be mentioned that the transfer of heat to the cooling water can also cause some slight change in the refractive index, and therefore any measurements taken from the reflectometer need to take account of this. A useful parallel the these phenomena is the twinkling of stars in a night sky, which is caused by exactly the same dynamic alteration in the refractive indices of space and the earth's atmosphere.
Indeed, the refractive indices of all the various fluids and solids through which the incident and reflected light pass needs to be taken into account in preparing useful data for analysis, and which might ultimately be used to determine the physical characteristics of the semiconductor under test.
It is an object of the following invention to provide an improved means for real-time monitoring of semiconductor characteristics during growth which overcomes the above problems, and provides improved data for analysis.
BRIEF SUMMARY OF THE DISCLOSURE
According to the invention there is provided a reflectometery technique for gathering meaningful reflectance data indicative of one or more characteristics of a substance being grown within a reaction chamber at the time of measurement, said technique including the steps of directing light from a light source of known characteristics into a reaction chamber towards the surface of the substance being grown therein, and collecting the light reflecting from said surface at a detector whereat the received light is converted into electrical signals which are subsequently subjected to computer processing, characterised in that the angle of incidence, and thus the angle of reflection of the light with the surface of the substance being grown is acute.
Preferably, the angle of incidence and reflection with the substance being grown is 46°.
Most preferably, the reaction chamber cross-sectional shape is polygonal, and apertures, preferably in the form of circular holes or cuts, are provided at suitable locations both axially of said reaction chamber and transversely of the cross-section such that the light from the source may pass into the reaction chamber to one side of the substrate on which substance growth occurs and emerge after being reflected from the surface of the substance being grown to a substantially opposite side of the cross-section of said reaction chamber. Most preferably, the substrate on which substance growth occurs is provided substantially centrally of the cross-section of said reaction chamber.
Most preferably, the reaction chamber is polygonal with at least two of the vertices of said polygon being disposed on either side of the substance being grown therein.
Most preferably, cuts or holes are provided in a first and second vertex of said polygon, said first and second vertices being a suitable distance axially of said reaction chamber to allow light from the light source to pass unimpeded through the first vertex to then impinge on the surface of the substance being grown, and subsequently be reflected therefrom through the cut or hole in the second vertex and subsequently towards the detector disposed to the alternate side of the reaction chamber from the light source.
Most preferably, the technique includes the further step of providing an outer jacket to the reaction chamber, and furthermore water cooling said outer jacket. Preferably the outer jacket is of a quartz material through which light may pass. It is to be mentioned that the outer jacket of the reaction chamber is generally continuous and forms part of a sealed system which is continuously purged. As mentioned above, the gases used in semiconductor growing techniques are noxious and highly toxic, and therefore despite the provision of apertures in the reaction chamber in accordance with the invention, none of the gases can actually escape from the system as a whole.
Most preferably the technique includes the steps of filtering the light incident on the detector according to its polarisation, in particular by applying a polarising filter to the detector to eliminate any unwanted polarity components of the light incident thereon.
It is worth mentioning that the polarity of the incident light is very important as far as obtaining meaningful reflectance data is concerned because certain components of the light are absorbed more than others on incidence with the surface of the substance being grown. Off-angle reflectance causes phase shifts (the basis of reflectometry) in the wavelength, and as such it is important to isolate only a single component of the light—the mathematical analysis of the data gained from this is complex and not relevant here, except to say that additional processing must be completed for off-angle reflectance data received.
According to a second aspect of the invention there is provided reflectometry apparatus for gathering meaningful reflectance data indicative of one or more characteristics of a substance being grown within a reaction chamber in real time during growth, said apparatus including a light source disposed to the outside of said reaction chamber which includes a substantially horizontal substrate on which the substance growth occurs, and a detector also disposed to the outside of the reaction chamber but on the opposite side of the reaction chamber to that at which the light source is disposed, said detector being capable of converting light into electrical signals which are subsequently subjected to computer processing, characterised in that the light source is disposed to one side of the reaction chamber so as to direct light thereinto such that it impinges on the surface of the substrate, or the surface of the substance being grown thereon, at an acute angle and is reflected away therefrom at a similarly acute angle to the detector, which is disposed to the alternate side of the reaction chamber from that of the light source when said reaction chamber is viewed in end elevation.
Most preferably, the reaction chamber cross-sectional shape is polygonal, with at least two of the vertices of said polygon being disposed on either side of the substance being grown therein, each of said two vertices having apertures provided therein at a suitable distance axially of said reaction chamber to allow light from the light source to pass unimpeded therethrough, said light subsequently reflecting off the surface of the substance being grown and thence through the second cut in the second vertex and subsequently towards the detector.
Preferably the reactor chamber is rectangular or square in cross-section, and the substrate on which substance growth occurs is disposed substantially centrally of the cross-sectional area.
Most preferably, the reaction chamber forms part of a known piece of reflectometry apparatus, such as the Aixtron Aix 200. Specifically, it is preferred that a substantially cylindrical water cooled out jacket is provided surrounding the reaction chamber, preferably of a quartz material, and that the light source and the detector are mounted proximate or adjacent the outside surface of the water cooled jacket.
Further preferably the reaction chamber is provided with a susceptor material which is excited to a desired temperature by one or more radio-frequency coils disposed around the outer or inner surface of the water-cooled outer jacket.
The reaction chamber is one in which semiconductor material is most expediently grown on the substrate, which is preferably of a sapphire material.
In a yet further aspect of the invention there is provided a reaction chamber in which there is disposed a susceptor block atop of which is disposed a substrate suitable for the growing of semiconductor materials, said chamber being elongate and substantially tubular such that gaseous semiconductor precursor material might be caused to flow therethrough, characterised in that a pair of apertures is provided to one side of a first imaginary line drawn through the geometric centre of the cross-sectional shape, a first of said apertures being disposed to one side of a second imaginary line perpendicular to the first, and the second of said apertures being provided to the other side of said second imaginary line.
Preferably the cross section of the reaction chamber is polygonal having a first vertex and a second vertex disposed on opposite sides of the second imaginary line, said apertures being coincident with said vertices.
Most preferably the cross-section of the reaction chamber is rectangular or square, and the apertures, in the form of cuts are provided in the vertices on either side of one of the faces of said chamber, said cuts or holes being deep enough to create apertures through the walls of said chamber.
The applicant herefor has found that despite the need for significantly more complex processing algorithms in the PC attached to the detector which processes signals received therefrom on account of the off-angle reflectance data being received, the resulting measurement, calculation and determination of physical characteristics is markedly improved when conducting reflectometry in the manner described.
A further advantage is that the quantity of gas escaping through the cuts or holes in the vertices of the rectangular chamber is practically nil, and this further improves the technique because it results in lower quantities of deposits on the inside surface of the outer, water cooled jacket, which in turn further diminishes the amount of light ultimately received at the detector and thus compromises the quality of measurement.
An additional advantage, and one which concerns semiconductor material manufacturers, is that the drilling of holes or making of cuts in the reactor compromises the quality of the material being grown therein, particularly when the hole is provided directly above the substrate. In the present invention, the applicants have not encountered any reduction or compromise in the material quality, and they perceive this as significant, particularly as there is belief that an aperture or hole drilled in the reactor immediately above the growing substrate does indeed have a prejudicial impact on the quality of the resulting semiconductor.
Although not described in great detail in this specification, the software loaded on the PC which is used to analyse the data received from the detector conducts a number of different processes. Firstly, the software includes algorithms which reduce beam twinkle. Secondly, a smoothing function is applied to the data received, and thirdly, and perhaps most importantly, the software includes algorithms which perform matrix transformations on the data to account for the fact that the data is received from light incident on and reflected from the semiconductor material in so-called “off-angle” manner, i.e. at an acute angle. The reader should be aware of a publication by John Lekner in this regard, entitled “Theory of reflection of electromagnetic and particle waves”, Nijhoff/Kluwer (1987), ISBN 90-247 3418-5.
By using the apparatus and method described above, it is possible to grow semiconductor materials in a much improved and more expedient manner, in particular by drastically reducing spin-up time, improving semiconductor recipes, and avoiding semiconductor growth wastage.
Importantly, the provision of apertures in the corners of the reaction chamber does not appear to materially affect the growth characteristics of the semiconductor, which is not believed to be the case for normal reflectometery where a 5 mm aperture is cut in the reaction chamber immediately above the substrate and growing semiconductor.
A specific embodiment of the invention will now be provided by way of example with reference to the following drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of the prior art, in particular of an Aixtron AIX 200 RF horizontal MOVPE reactor,
FIG. 2 shows a graph of in-situ reflectance spectra obtained during MOVPE growth of GaN-the two curves represent different sapphire substrates and therefore indicate strong differences in the initial stages of growth.
FIG. 3 shows a schematic perspective view of the apparatus according to the invention,
FIG. 3A shows an enlarged perspective view of the reaction chamber of the apparatus of FIG. 3 ,
FIG. 4 shows a graph of data points obtained during a particular semiconductor growth run,
FIG. 5 shows the graph of data points of FIG. 4 after having been subjected to a simple filtering routing,
FIG. 6 shows the data of FIG. 5 after having been subjected to processing analysis,
FIG. 7 shows a theoretical interferogram generated from GaN on sapphire with a light composed of 50% p- and 50% s- polarised light, and
FIG. 8 shows a second interferogram generated from data collected during AlGaN on GaN growth on sapphire, after filtering and processing analysis, and after having data spikes removed.
DETAILED DESCRIPTION
Referring to FIG. 3 , there is shown a schematic view of a semiconductor growing apparatus 30 according to the invention having a reaction chamber 32 of rectangular cross-section, and outer jacket 34 which is water cooled, possibly by means of this outer jacket being constituted of two concentric glass cylinders having a gap therebetween through which water can be pumped.
To the outside of the outer jacket there is provided one or more radio-frequency heating coils 36 which provide a source of intense RF energy to the susceptor block indicated generally at 38 and disposed on the inside of the reaction chamber 32 . A substrate, typically of sapphire, is positioned on said block 38 , and it is on this substrate which semiconductor growth occurs.
In use, a source of semiconductor pre-cursor material is cause to flow (under entirely hermetic conditions, given its toxicity) through the inside of the reaction chamber, as shown at 35 , over the substrate and expelled under controlled conditions as indicated at 37 . This gas, and subsequent metal organic gases which may be used during the growth process, may be heated strongly to over 500° C., and in certain instances to over 1000° C. It has long been known that semiconductor growth is highly susceptible to changes in pressure and temperature, and it is important to achieve relatively stable pressure and temperature inside the reaction chamber if uniform and useful growth is to be achieved.
In accordance with the invention, there is provided a source of light 40 , which is preferably a laser, and a detector 42 covered at the light receiving end thereof with a polaroid filter 44 which eliminates unwanted components of the reflected laser light. A computer 46 is connected to the detector to analyse and process the data received. In use, the metal organic gas flows over the heated substrate and after a first initial nucleation stage during which the semiconductor material is first nucleated on the substrate, additional molecules of semiconductor are grown on the first layer. The laser light is directed from one side of the reaction chamber and from the outside of the water cooled outer jacket into the reaction chamber through a first aperture 48 provided at a suitable location in one corner of the reaction chamber at a suitable location axially thereof, onto the growing semiconductor material, and then out through a second aperture 50 provided in the opposite corner and in the same region axially of the reaction chamber.
A typical growth run involves heating the susceptor to 1150° C. This creates a very significant amount of turbulence in the cooling water. In turn, this turbulence can cause the laser beam reflected from the substrate to move randomly by an estimated 1-2 mm. The physics behind this phenomenon is exactly the same as that behind the twinkling of distant street lights or of stars—the changes in density of the fluid through which the light passes results in subtle change in the refractive index of the fluid and hence in the optical path of the light. The consequence of twinkling in our application is that the laser beam can be deflected away from the second aperture in the reaction chamber, resulting in reduced intensity spikes in the data. This is clearly demonstrated in FIG. 4 which is a sample of raw data as collected during a particular growth run. After a simple filtering and spike removal routine is conducted on this data, a clearer set of data is obtained, as can be seen in FIG. 5 .
This data can then be analysed using the proprietary R-Fit v2.1 Software program, which results in the data presented in FIG. 6 .
Apart from the noise spikes which are largely removed, the data also has a substantial amount of high frequency, low-level random noise. This could be due to either;
a) A small but noticeable fluctuation in the transmission characteristics of the cooling water due to thermal effects or b) The laser beam diameter being very close to the width of the exit slit in the inner liner. When this occurs, any slight movement in the reflected beam due to substrate wobble, twinkling or particles in the cooling water can cause it to graze against the exit slit and so reduce the light intensity arriving at the detector, i.e. marginal diffraction.
If the low-level noise is due to (a), then the most effective solution is to mathematically smooth the data. If the low-level noise is due to (b), then the best way to remove it is to reduce the diameter of the laser beam and/or increase the width of the exit slit. During this experiment the laser beam diameter was approximately 1.5 mm; it is possible to reduce it to less than 0.5 mm.
The main features to observe from the interferogram of FIG. 6 are;
a) the refractive index of GaN is too small and b) the intensity of the oscillations falls off with time.
The refractive index of GaN should be around 2.19 whereas in order to achieve a fit, a value around 1.83 had to be used in the software. The reason for this discrepancy is that the reflectance system used under experimental conditions does not take into account the mixed polarisation of the laser beam. The mathematical model behind the R-Fit v2.1 software is based on p-polarised light only and the laser source used provided a mixed s- and p-polarised beam. This situation can be simulated by generating a theoretical interferogram from a layer of GaN on sapphire when it is illuminated with light composed of 50% s- and 50% p- polarisation, as shown in FIG. 7 . In this case, the refractive index of GaN necessary to achieve a good fit is 1.86, less than the true value of 2.19 and close to the value of 1.83 used in the real data presented in FIG. 6 .
It is for this reason that the polaroid filter 44 is employed to allow only p- polarised light through to the detector.
The reduction in the intensity of the oscillations is typical of a layer that is roughening and indeed a roughening factor is necessary in order to achieve the fit shown in FIG. 7 . This was confirmed when the sample was removed from the reactor and subsequently analysed. It transpires that the roughnesses was a consequence of performing the growth with a recently cleaned liner and not as a result of introducing the two cuts in the inner liner since subsequent growths resulted in significantly smoother layers; see FIG. 8 .
In a second growth run conducted using the experimental apparatus, a layer of GaN was deposited followed by a thinner layer of AlGaN. The interferogram recorded from this run is displayed in FIG. 8 . This also demonstrated the effects of twinkling which resulted in data spikes which were removed using the same mathematical filtering routine as above. Likewise, the data has a certain degree of low-level high frequency random noise; most likely due to the closeness between the diameter of the laser beam and width of the exit slit. If this is the case then it can be removed by adjusting the laser beam diameter.
The main features to note from the interferogram of FIG. 8 are:
a) the oscillations reduce in intensity only slightly and b) after the third maxima, the rate of change of intensity is greatly reduced.
The smaller change in peak intensities is characteristic of a layer that is roughening slightly as it evolves. Again, a roughening factor had to be employed to achieve a good fit, but in this case the final rms roughness was less than half that necessary in the first growth run. Again, this was confirmed with post growth analysis; the layer looked to be as smooth as previous ‘good’ layers.
The change from GaN to AlGaN is very clear. At the boundary, there is a period of 107 s between the termination of the GaN layer and the beginning of the AlGaN layer. From the analysis presented in FIG. 8 , it looks likely that during this time interval there was no significant loss of GaN due to sublimation—the substrate is still at 1150° C. at this stage and it is possible to inadvertently remove GaN during such pauses in growth.
The refractive index necessary to fit the AlGaN layer is less than that necessary for the GaN, entirely consistent with the known refractive index of this alloy, although because of the uncontrolled polarisation of the detected beam, the absolute value is inaccurate.
The rate of evolution of the AlGaN layer is significantly lower than was observed in the GaN case. From the analysis it looks to be between 15% 20% of the rate measured for GaN. Again, the polarisation effect prevents us from quantifying with any degree of accuracy the rate of film evolution and the film thickness, but it is possible to estimate that the AlGaN layer is approximately ⅛th the thickness of the GaN layer.
This it can be seen from this experimental data above that the procedure and apparatus according to the invention are of great advantage in determining various growth and physical characteristics of the semi-conductor being grown.
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A reflectometry method and apparatus for gathering reflectance data indicative of one or more characteristics of a semiconductor substance being grown on a substrate within a reaction chamber. The method includes directing light of known characteristics from a light source into the reaction chamber towards the surface of the semiconductor at an acute angle, preferably 46°, and collecting the light reflected from the surface at a detector located on the other side of the chamber. The received light is then converted into electrical signals which are subsequently subjected to computer processing. The reaction chamber can have a rectangular cross-sectional shape with apertures cut in the two vertices of the reaction chamber located above the substance to thereby allow the light to pass into the reaction chamber at the acute angle and out again after having been reflected from the surface of the semiconductor.
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FIELD OF THE INVENTION
The present invention relates to a method and a device for automatically preventing unnecessary alerts produced by the anticollision systems carried onboard airplanes, upon a change of altitude, as well as an airplane provided with such a device.
BACKROUND OF THE INVENTION
It is known that most airliners are equipped with anticollision systems (generally called TCAS systems for Traffic Collision Avoidance Systems) which make it possible to ensure the safety of air traffic by preventing the risks of in-flight collision.
Thus, when two airplanes are converging toward one another, their anticollision systems calculate an estimate of the collision time and emit an alert informing the crews of each airplane of a possible future collision: such an alert is generally called “traffic advisory” or “TA alert”. If appropriate, said anticollision systems emit moreover, for the attention of the crew, an order regarding an avoidance maneuver in the vertical plane so as to get out of the situation in which a collision is possible: such an avoidance maneuver order is generally called “resolution advisory” or “RA alert”. The TA and RA alerts are manifested through voice messages and through the displaying of information in flight decks.
In practice, an onboard anticollision system calculates a collision time in the horizontal plane (ratio of the horizontal distance of the two airplanes to their relative horizontal speed) and a collision time in the vertical plane (ratio of the vertical distance of the two airplanes to their relative vertical speed). Said collision times thus calculated are compared with predetermined thresholds for the TA alerts and for the RA alerts (said predetermined thresholds being moreover dependent on the altitude) and said alerts are triggered when said calculated collision times are less than the corresponding predetermined thresholds.
Moreover, it is known that frequently an airplane has to capture (while climbing or descending) a stabilized altitude level neighboring another altitude level allocated to another airplane and that, according to the rules of air navigation, two neighboring stabilized altitude levels are separated by only 300 m (1000 feet).
Hence, because of this small difference in altitude between stabilized altitude levels, the high vertical speed of modern airplanes and the weight of air traffic, said anticollision systems produce numerous TA and RA alerts, even though the airplane, shifting vertically so as to change altitude, is maneuvering correctly without any risk of collision with another airplane. These alerts induce a great deal of stress and are deemed operationally unnecessary by pilots, since the change-of-altitude maneuver is correct and their consideration leads to traffic disruption in most cases.
Moreover, the RA alerts during the altitude capture phases are very numerous and it is estimated that they currently represent more than 50% of the total of these alerts in European space, this percentage being apt to increase in the future owing to the expansion of air traffic.
SUMMARY OF THE INVENTION
The object of the present invention is to remedy this drawback.
To this end, by virtue of the invention, the method for limiting the number of alerts emitted by an anticollision system on board an airplane which performs a change-of-altitude maneuver comprising a phase of capture of a setpoint altitude, said anticollision system being able to detect an intruder aircraft situated in the aerial environment of said airplane, to calculate a theoretical collision time between said airplane and said intruder aircraft and to emit at least one alert when this theoretical collision time is less than a predetermined threshold, is noteworthy in that, when said airplane is close to said setpoint altitude and air traffic exists in the environment of said airplane, the duration of said capture phase is adjusted so that said theoretical collision time is greater than said predetermined threshold.
Thus, by keeping the theoretical collision time greater than said predetermined threshold by adjusting the duration of the capture phase, the untimely triggering of unnecessary, or indeed even detrimental, alerts is avoided, without however endangering the safety of said airplane and of the intruder aircraft.
The duration of said capture phase can be adjusted by controlling the vertical speed of said airplane. Such control can for example consist in keeping said vertical speed below a speed threshold, thereby making it possible in this case to lengthen the duration of the capture phase.
As a variant or supplement, the duration of said capture phase can also be adjusted through advanced commencement of the latter.
According to the invention, said airplane can be considered to be close to said setpoint altitude when the absolute value of the difference of said setpoint altitude and of the current altitude of said airplane is less than a height threshold representative of the zone of occurrence of said alert.
Furthermore, according to the invention, air traffic is considered to exist in the environment of said airplane when:
either the configuration of capture of said setpoint altitude by the airplane is similar to a reference capture configuration liable to trigger at least one unnecessary alert; or said theoretical collision time is less than said predetermined threshold increased by a temporal margin. Thus, it is possible to advance the triggering of an alert with the margin on the predetermined threshold. This condition can optionally be combined with the previous one; or at least one alert is emitted by said anticollision system of the airplane, this condition possibly being combined with the first.
Moreover, the invention relates to a device for the implementation of the method described above making it possible to limit the number of alerts emitted by an anticollision system on board an airplane which performs a change-of-altitude maneuver comprising a phase of capture of a setpoint altitude, said anticollision system being able to detect an intruder aircraft situated in the aerial environment of said airplane, to calculate a theoretical collision time between said airplane and said intruder aircraft and to emit at least one alert when this theoretical collision time is less than a predetermined threshold.
According to the invention, the device comprises:
activatable control means for automatically adjusting the duration of the capture phase so that said theoretical collision time is greater than said predetermined threshold; and activation means able to automatically receive information from said anticollision system and to activate said control means when said airplane is close to said setpoint altitude and air traffic exists in the environment of said airplane.
Furthermore, the control means for adjusting the duration of the capture phase can for example establish a vertical speed order intended for a flight computer of the airplane controlling its longitudinal-control surfaces and/or its engines, and/or trigger in advance the setpoint altitude capture phase, thereby increasing the setpoint altitude capture time.
The invention also relates to an aircraft provided with a device such as mentioned above.
The figures of the appended drawing will elucidate the manner in which the invention may be embodied. In these figures, identical references denote similar elements.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a device in accordance with the invention making it possible to limit the alerts emitted by an anticollision system on board an airplane AC.
FIGS. 2A and 2B represent in schematic form the airplane AC during a change-of-altitude maneuver with a setpoint altitude capture, respectively in the descent phase ( FIG. 2A ) and in the climb phase ( FIG. 2B ).
FIGS. 3 and 4 each illustrate, in a schematic manner, an example of a reference configuration of capture of the setpoint altitude by the airplane AC in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Represented in schematic form in FIG. 1 is a device 1 , in accordance with the invention, carried onboard an airplane AC. Such a device 1 is intended to limit the number of alerts emitted by a TCAS anticollision system 2 on board the airplane AC, when the latter performs a change-of-altitude maneuver to capture a setpoint altitude Zc. In this figure, the device 1 , the anticollision system 2 and a flight computer 5 are represented outside the airplane AC, although, in reality, they are on board the latter.
In a customary manner, the anticollision system 2 is able to detect an intruder aircraft in the environment of said airplane AC, to calculate a theoretical time for collision t col between the latter and said intruder aircraft and to emit an alert for the attention of the crew of the airplane AC in the case where said theoretical collision time is less than a predetermined threshold.
As shown by FIG. 1 , such a device 1 comprises:
activation means 3 , connected to the anticollision system 2 of the airplane AC by way respectively of the link L 1 . These activation means 3 thus receive information relating to the intruder aircraft (for example its altitude). They also receive, by way of the link L 2 , information relating to the airplane AC (for example its vertical speed, its altitude, etc.) originating from its various onboard measurement instruments (not represented). When engagement conditions (detailed subsequently) are met, the activation means 3 are able to automatically activate control means 4 ; and the control means 4 , which are connected to the activation means 3 by way of the link L 3 . They receive, by way of the link L 4 , data representative of the state of said airplane AC. When they are activated by the activation means 3 , the control means 4 can determine a vertical speed order (in the manner described hereinafter) to be applied to the airplane AC so as to avoid the triggering of an alert and can transmit it to the flight computer 5 of the airplane AC. As a variant or supplement, after having been activated by the activation means 3 , the control means 4 can trigger in an advanced manner the setpoint altitude Zc capture phase.
The flight computer 5 , connected in particular to the control means 4 by way of the link L 5 , is able to deliver control orders, by way of the links L 6 , for example to the actuators of the surfaces 6 allowing the longitudinal control of the airplane AC (elevators, airbrakes) and/or to the engines 7 of said airplane, so as to apply the vertical speed order determined by the control means 4 .
Schematically represented in FIGS. 2A and 2B is the airplane AC in the course of a change-of-altitude maneuver with capture of a setpoint altitude Zc, respectively while descending ( FIG. 2A ) and climbing ( FIG. 2B ). As represented, such a change-of-altitude maneuver comprises the following three successive phases:
a descent (or climb) phase, in the course of which the approach trajectory 8 of the airplane AC is substantially rectilinear and is traveled at a substantially constant vertical speed up to a point 9 situated at a height h above (or below) the setpoint altitude Zc to be attained; an altitude capture phase, in the course of which the capture trajectory 10 of the airplane AC is rounded out, for example parabolic, and becomes tangential at 11 to the setpoint altitude Zc; and a stabilization phase, in the course of which the trajectory 12 of the airplane AC follows said setpoint altitude Zc.
The altitude capture time t cap corresponds to the flight time of the airplane AC on the trajectory 10 , between the points 9 and 11 . It is determined by the altitude capture law automatically piloting the maneuver.
Although the airplane AC correctly executes its setpoint altitude Zc capture and there is no risk of collision with an intruder aircraft Al, it is possible that the anticollision system 2 of said airplane AC may emit an alert, for example because it has detected such an intruder aircraft Al beyond the setpoint altitude Zc. Such an alert is therefore unnecessary, and even detrimental and the object of the present invention is therefore to eliminate it. Accordingly, said airplane AC is slowed down in its setpoint altitude Zc capture, for example by acting on the longitudinal control surfaces and/or the speed of the engines of said airplane AC.
By assuming, as is represented in FIGS. 2A and 2B , that:
the airplane AC is situated at a point Mo of the capture trajectory 10 corresponding to an altitude Zo, which differs from the setpoint altitude Zc by a height ΔZ, the vertical speed of said airplane AC being equal to Vzo at the point Mo; the altitude of the intruder aircraft Al is equal to Zi; and the predetermined threshold of the anticollision system of the airplane AC (for example the RA alert threshold) is then denoted by S,
the prevention of an alert will be achieved if the absolute value of the ratio |(Zi−Zo)/Vzo)| is greater than said threshold S (i.e. |(Zi−Zo)/Vzo)|>S), that is to say if Vzo is less than the ratio |Zi−Zo|/S (i.e. Vzo<|Zi−Zo|/S).
Thus, the vertical speed Vzo of the airplane AC, making it possible to prevent anticollision alerts, can be estimated at each instant as a function of the altitude Zo of the airplane AC (known by the onboard altimeters), of the altitude Zi of the intruder aircraft Al (determined by the anticollision system of the airplane AC) and of said threshold S of said anticollision system.
If, in accordance with the aerial separation rules in force, the altitude Zi of the intruder aircraft Al is separated by 300 m (1000 feet) from the setpoint altitude Zc, the vertical speed Vzo of the airplane AC must be less than (ΔZ+300)/S (i.e. Vzo<(ΔZ+300)/S).
As a variant of or supplement to the foregoing, and as also represented in FIGS. 2A and 2B , a slowing down of the airplane AC in its capture of the setpoint altitude Zc can moreover be obtained by advancing the capture of the setpoint altitude Zc, that is to say by triggering the phase of capturing the altitude Zc at a point 9 ′ of the approach trajectory 8 of height h+dh greater than the height h of the point 9 . The capture time is then increased by dt cap with respect to the capture time t cap .
After such an advance, the vertical speed Vzo of the airplane AC can be limited in the manner described above.
It will be noted that, though the method in accordance with the present invention described with regard to FIGS. 2A and 2B makes it possible to eliminate unnecessary alerts, on the other hand it considerably lengthens the time required by the airplane AC to attain the setpoint altitude Zc.
Hence, according to another aspect of the present invention, the process for slowing down said airplane AC is limited to engagement conditions that are judiciously defined so as to avoid the systematic lengthening of all the altitude capture maneuvers.
Thus, according to a preferred embodiment of the invention, the process for slowing down the airplane AC is implemented when the following engagement conditions are simultaneously met:
a first condition relating to the proximity of the airplane AC in relation to the setpoint altitude Zc to be attained. Assuming that, at an instant t, the airplane AC is situated at a current altitude Z(t) and is following the approach trajectory 8 (climb or descent phase preceding the capture phase) or else the capture trajectory 10 , the first condition is met when the absolute value of the difference of the setpoint altitude Zc and of the current altitude Z(t) of the airplane Z(t) is less than a height threshold S h (i.e. |Zc−Z(t)|<S h ), the height threshold S h being representative of the zone of occurrence of the TA and RA alerts during a descent (or climb) phase preceding the altitude Zc capture phase or during the capture phase itself. Thus, this first condition makes it possible to restrict the engagement of the slowdown process to the aforesaid phases, in the course of which it is preferable to reduce the vertical speed of the airplane AC because said speed could potentially generate TA or RA alerts; and a second condition relating to air traffic in a predetermined zone surrounding said airplane AC. This second condition makes it possible to restrict the engagement of the process for slowing down said airplane AC solely when the proximity with an intruder aircraft Al justifies a vertical speed reduction. It may involve various items of information provided by the TCAS anticollision system (TA alert and RA alert, data relating to the intruder aircraft Al).
Thus, in a first exemplary embodiment, the TCAS anticollision system determines the following information:
the presence or otherwise of an intruder aircraft Al in a predetermined detection zone, for example a rectangular zone centered on the airplane AC and defined by a vertical side of 3600 m (18000 feet) and a horizontal side of 55 km (30 nautical miles); and, should an intruder aircraft Al be detected in said detection zone, parameters associated with said intruder aircraft Al (relative altitude, vertical speed, etc.)
The analysis of the aforesaid information provided by the anticollision system 2 makes it possible to characterize the configuration of capture of the setpoint altitude Zc by the airplane AC as a function of the intruder aircraft. This capture configuration is then compared with reference capture configurations, which require the triggering of the process for slowing down said airplane AC to prevent unnecessary TA alerts (and a fortiori RA alerts).
Thus, in this first exemplary embodiment, the second condition is satisfied when the configuration of capture of the setpoint altitude Zc by the airplane AC is similar to one of the aforesaid reference configurations.
As shown by FIG. 3 , a reference configuration can be characterized by:
an intruder aircraft Al in level flight at a stabilized altitude level Zi; the airplane AC in the climb phase (or descent phase in a variant of this configuration, not represented in FIG. 3 ) converging towards this intruder aircraft Al; and the setpoint altitude Zc situated 300 m (1000 feet) below (or above in the variant) the stabilized altitude level Zi.
Furthermore, in FIG. 4 , another reference configuration has been represented which can be characterized by:
an intruder aircraft Al in the climb phase (or descent phase in a variant of this configuration, not represented in FIG. 4 ); the airplane AC in the descent phase (or climb phase in the variant) converging towards the intruder aircraft Al; the setpoint altitude Zc situated between the airplane AC and the intruder aircraft Al; and the setpoint altitude Zi of the aircraft Al situated 300 m (1000 feet) below (or above in the variant) the setpoint altitude level Zc.
As a variant or supplement, in a second exemplary embodiment, the second condition is satisfied when the theoretical collision time t col (described above) is less than the threshold S (for example the TA alert threshold) increased by a margin T (i.e. t col <(S+T)). Thus, it is possible to advance a TA alert with a margin T on the alert threshold S.
Of course, it is conceivable to combine the second conditions of the first and of the second exemplary embodiments, so as to form a new second condition that is met when the configuration of capture of the airplane AC is similar to a reference configuration and the theoretical collision time t col is such that t col <(S+T).
Moreover, in a variant of the preferred embodiment, the second condition relating to the air traffic is satisfied as soon as a TA alert is emitted by the anticollision system 2 , thereby making it possible only to prevent the emission of RA alerts.
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The invention relates to a method and device for limiting the number of alarms generated by an anticollision system on board an airplane according to which the duration of a phase of capture of a setpoint altitude by the airplane is adjusted so that a theoretical time for collision with an intruder aircraft is greater than a predetermined threshold, when the airplane is close to said setpoint altitude and air traffic exists in the environment of said airplane.
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FIELD OF THE INVENTION
[0001] The invention relates to load bearing lifting belts, in particular, to a tensile load sensing lifting belt for connecting to a circuit for detecting a strain change in a tensile member.
BACKGROUND OF THE INVENTION
[0002] Lifting belts generally comprise a tensile member contained within an elastomeric outer covering. The belt tensile member is for the most part used solely to provide the means of supporting the weight to be lifted.
[0003] Prior art wire ropes are available that combine a sensor and load bearing capability. These use the wire rope tensile members as strained elements in combination with a voltage bridge for measuring a strain in the tensile member. However, these wire ropes are not continuous and comprise a plurality of parallel conductors that are connected to attachment ends of the rope. They also comprise connectors at each end whereby the rope is connected to a load.
[0004] Representative of the art is U.S. Pat. No. 3,958,455 (1976) to Russell which discloses a transducer of the resistance wire rope type wherein strained resistance wires are adapted to function both as a sensor and load bearing member.
[0005] Also representative of the art is U.S. Pat. No. 3,950,984 (1976) to Russell which discloses a transducer of the resistance wire rope type wherein strained resistance wires are adapted to function both as a sensor and load bearing member.
[0006] What is needed is a lifting belt having a tensile member having a resistance used as a sensor and load bearing member enclosed in a dielectric elastomeric body. The present invention meets this need.
SUMMARY OF THE INVENTION
[0007] The primary aspect of the invention is to provide a lifting belt having a tensile member having a resistance used as a sensor and load bearing member enclosed in a dielectric elastomeric body.
[0008] Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.
[0009] The invention comprises a lifting belt having at least one tensile member adapted to function as a sensor and a load bearing member. The tensile member has a predetermined resistance. The belt comprises an electrically insulating elastomeric body in which the tensile member is enclosed. The tensile member comprises a portion of a series electrical circuit connected to a bridge circuit for detecting resistance changes in the tensile member caused by a strain in the tensile member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a schematic view of the inventive system.
[0011] [0011]FIG. 2 is a cross-sectional view of the belt.
[0012] [0012]FIG. 3 is a cross-sectional view at line 3 - 3 in FIG. 1.
[0013] [0013]FIG. 4 is a graph of the resistance of a tensile member versus belt tension.
[0014] [0014]FIG. 5 is a sectional perspective view of an alternate embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] [0015]FIG. 1 is a schematic view of the inventive system. Belt 100 comprises tensile cords running the full length of the belt along a major axis. Tensile cords 10 are embedded in elastomeric material 11 in such a way so as to prevent contact between adjacent cords 10 along the length of the belt.
[0016] Each tensile cord is connected in series to the next cord at alternate ends of the belt to form a series circuit. Leads 201 and 202 extend from an end of belt 100 for connecting to a Wheatstone bridge 200 or other four arm or two arm voltage/resistance bridge. A meter or other appropriate output display 300 can be connected across the bridge to provide a visual reading of a voltage across the bridge and thereby across the tensile member.
[0017] Tensile cords 10 comprise metallic wires or cords that bear and support a load. Cords 10 are electrically conductive.
[0018] Alternatively, a single conductive tensile cord 10 may extend along the length of the belt to which leads 200 and 201 are connected at each end in the manner described herein. The single conductive tensile cord would be used in conjunction with other conductive or non-conductive tensile cords, depending on the load bearing requirements of the belt.
[0019] Elastomeric 11 may comprise any one of a number of known elastomer compositions known in the art including but not limited to chloroprene rubber or EPDM. Elastomeric 11 is dielectric in order to electrically insulate each tensile cord from the others along the length of the belt body. A dielectric constant, ε r , for the elastomeric is in the range of 1.5 to 10.0.
[0020] Resistors R 2 , R 3 , and R 4 have known resistance values and R 1 is a resistance of the tensile cord series circuit. A change in the tension/strain or a break in the tensile cord circuit will affect R 1 , thereby changing a voltage V across the bridge. The change would register on display 300 .
[0021] The magnitude of R 1 is first measured in the unstressed or unloaded condition. R 4 is then adjusted to balance the bridge in the unstressed condition. Then, as the belt is loaded, the strain changes the resistivity of the tensile cords, causing a voltage V to change. The voltage change may include registration of strain up to and including total failure of one or all of the tensile cords. One can appreciate that failure of a single tensile cord on the circuit will cause resistance R 1 to approach ∞ ω. This will result in a marked change in voltage V across the bridge, alerting a user who can then take the equipment out of service or make repairs.
[0022] In service, belt 100 is clamped at each end by mounting bracket M 1 and M 2 . Each mounting bracket grips the belt body, thereby affixing it to a cable drum or elevator car or other piece of equipment. In the preferred embodiment the belt has discrete ends to which the mounting brackets are clamped, such as in the case of a rope, as opposed to an endless belt.
[0023] In an alternate embodiment the belt comprises an endless or continuous member, also operating in a lifting capacity. In the alternate embodiment leads 201 and 202 project from a side of the belt body, or the leads extend along a side of the continuous belt as shown in FIG. 5. The tensile cords 10 are connected in series as described herein with the side leads 500 , 501 located on the sides of the belt, 507 , 508 respectively, for connecting the belt to the bridge circuit. Leads 500 , 501 contact a conductor for receiving a voltage signal, such as conductive pulley flanges (not shown) during operation. The leads 500 , 501 would be operationally similar to electric motor brushes in this way, electrically connecting to the pulley flanges during each pass through a pulley. Leads 500 , 501 may also extend or project along sides 505 and 506 . The belt leads would again comprise any electrically conductive material suited for the use, such as steel or carbon materials. This alternate embodiment may be used to indicate changes in belt tension caused by load changes or by normal wear, allowing adjustment thereof by use of a tensioning idler.
[0024] The preferred belt has an overall length sufficient for service in an elevator system or for use on forklifts. The strain gage aspect of the belt would alert a user to an overload condition through high strain or to potential degradation of condition of the tensile member, for example, failure of strands within a stranded tensile member.
[0025] [0025]FIG. 2 is a cross-sectional view of the belt. Belt 100 has an overall width w and an overall height h. The aspect ratio w/h of the preferred embodiment is generally in the range of 1 to 30, but may comprise any suited to the particular application. Tensile cords 10 are substantially parallel to each other along a length of the belt.
[0026] Jumpers 12 are shown between adjacent tensile members 10 . Jumpers 12 comprise conductors and are a portion of the series circuit between the tensile members. The jumpers are embedded within the belt body 11 and are located at each end of the belt. A like set of jumpers (not shown) is present on the opposing end of the belt, also comprising a portion of the series circuit, see FIG. 1.
[0027] [0027]FIG. 3 is a cross-sectional view at line 3 - 3 in FIG. 1. Clamp M 2 engages an end of the belt 100 adjacent to protrusions 13 , 14 . In the preferred embodiment, protrusions 13 , 14 extend across a width w of the belt. A single protrusion may also be used, for example, protrusion 13 . Protrusions 13 , 14 provide a positive mechanical engagement for the clamp to the belt to prevent the belt from being pulled through the clamp when it is under load L. Protrusions may also be used at the other end of the belt (not shown) in a like manner as shown in FIG. 3.
[0028] [0028]FIG. 4 is a graph of the resistance of a tensile member versus belt tension. The example depicted in the graph comprises a belt having ten steel cords 10 that are serially connected. The y-axis depicts the increase in resistance over a given base value for R 1 . The base value for R 1 is measured in the unstressed condition. One can see that the resistance increases generally linearly with the increase in tension or load. One can appreciate that the resistance would continue to increase with load until one or all of the tensile cords fails. Upon failure of a tensile cord the resistance goes to ∞ ω.
[0029] Compilation of the resistance readings over time would be a helpful tool in identifying belt maintenance intervals or to predict failures.
[0030] Although a form of the invention has been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein.
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The invention comprises a lifting belt having at least one tensile member adapted to function as a sensor and a load bearing member. The belt comprises an insulating elastomeric body in which the tensile member is enclosed. The tensile member comprises a series electrical circuit connected to a bridge circuit for detecting resistance changes in the tensile member caused by a strain in the tensile member.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/846,185 entitled ESTIMATION OF NOx GENERATION IN A COMMERCIAL PULVERIZED COAL BURNER USING A DYNAMIC CHEMICAL REACTORS NETWORK MODEL, filed on Jul. 15, 2013, which is incorporated herein by reference in its entirety and to which this application claims the benefit of priority.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to the mathematical modeling of chemical processes. More particularly, the invention relates to the modeling of a coal burning process in order to predict concentrations of nitrogen oxide (NOx) gases in the process effluent.
[0004] 2. Description of the Prior Art
[0005] Pulverized coal furnaces are presently in wide use. NOx emissions from coal furnaces largely originate from oxidation of the nitrogen atoms in the fuel itself, as opposed to atmospheric nitrogen. Pulverized coal burners of advanced design may reduce emissions of nitrogen oxides by a factor of 2 to 3 from uncontrolled combustion systems by staging the addition of oxygen to produce an initially fuel-rich regime in which the bound nitrogen is partially converted to N2.
[0006] The capability to predict and estimate effluent components has become critical in the design and operation of those coal furnaces. One important problem is the monitoring of NOx formation during the combustion process inside the furnace. It is currently not possible to measure temperature and NOx concentration inside the furnace during the combustion reactions. Indirect methods are therefore used. For example, computational fluid dynamics (CFD) simulation may be used to model the combustion reactions. That technique is typically too time-consuming to be practical in real applications.
[0007] Another technique for monitoring temperature and NOx concentration is the use of a chemical reactor network (CRN) to model the reaction. The creation of a CRN, often guided by CFD, gives insight into the complex phenomena that occur within the combustion chamber and are otherwise not measurable. A CRN model is constructed as a series of ideal reactors, connected with each other according to certain split ratios and flow rates. Currently, those parameters connecting one reactor to the others are determined by users' experience. The results are therefore dependent in large measure on the estimation of the algorithm parameters that are used.
[0008] Thus, a need exists in the art for a technique for accurately monitoring temperature and NOx concentration within a pulverized coal furnace.
[0009] An additional need exists for a useable procedure for building a chemical reactor network for use in accurately monitoring temperature and NOx concentration within a pulverized coal furnace.
[0010] Another need exists in the art for building a chemical reactor network including ideal reactors interconnected by tunable parameters that are established without reliance on the expertise of the users.
SUMMARY OF THE INVENTION
[0011] An object of embodiments of the invention is to accurately and efficiently monitor temperature and NOx concentration within a pulverized coal furnace without the time-consuming process of building a complete CFD model. Another object is to build a chemical reactor network for monitoring NOx concentration without relying on the expertise of the users for the determination of tunable parameters interconnecting the ideal reactor modules.
[0012] An additional object of the present disclosure is the creation of a chemical reactor network for monitoring NOx concentration that includes a tunable mapping model with parameters that are learned by comparing a model output with measurements of actual furnace conditions.
[0013] These and other objects are achieved in one or more embodiments of the invention in which a machine learning algorithm is used to learn the mapping model between the tunable parameters and the status of each point inside the furnace. The model is used to tune the parameters with existing measurements to predict furnace status using customers' input values. By using the machine learning model instead of the traditional CFD and CRN models, the temperature and NOx concentration inside the furnace is monitored and predicted more accurately and efficiently.
[0014] In embodiments of the present disclosure, a method is provided for estimating NOx generation in a coal burning furnace. The method includes measuring actual furnace outputs of the coal burning furnace, including NOx generation, for a known set of actual furnace inputs. A chemical reactor network is then constructed. The network comprises a plurality of ideal reactor modules, an input matrix defining chemical reactor network inputs, and a tunable parameter matrix defining split ratios and flow rates among the plurality of ideal reactor modules. The chemical reactor network, including an initially populated tunable parameter matrix, is then applied to a populated input matrix representing the known set of actual furnace inputs, to create an output matrix including an estimate of NOx generation. The actual furnace outputs are compared with the output matrix, and, based on the comparison, an adjusted tunable parameter matrix is created.
[0015] In other embodiments, the chemical reactor network inputs include concentrations of compositions in coal. In other embodiments, the chemical reactor network inputs include input air temperature and flow rate. In further embodiments, the output matrix further includes volumetric flow rate and temperature. In certain embodiments, the tunable parameter matrix further defines volumes of the ideal reactor modules.
[0016] In some embodiments, adjusting the tunable parameter matrix comprises grid searching for a best tunable parameter matrix. The best tunable parameter matrix may be a tunable parameter matrix yielding an output matrix having a smallest least squared error in comparison to the actual furnace outputs.
[0017] Some embodiments include repeating the operation of applying the chemical reactor network using the adjusted tunable parameter matrix. Constructing a chemical reactor network may be performed under an assumption that coal devolatilization depends only on coal composition and heating rate, and that coal distributions are equal for a given set of gas burners, and that air is distributed equally among a given set of air ports.
[0018] In other embodiments, a system is provided for estimating NOx generation in a coal burning furnace. The system includes a processor and an interface connected to the processor and connected to receive measurements of actual furnace outputs of the coal burning furnace, including NOx generation, for a known set of actual furnace inputs. The system additionally includes computer readable media containing computer readable instructions that, when executed by the processor, cause the processor to perform a number of operations. Those operations include constructing a chemical reactor network comprising a plurality of ideal reactor modules, an input matrix defining chemical reactor network inputs, and a tunable parameter matrix defining split ratios and flow rates among the plurality of ideal reactor modules. The operations further include applying the chemical reactor network, including an initially populated tunable parameter matrix, to a populated input matrix representing the known set of actual furnace inputs, to create an output matrix including an estimate of NOx generation; making a comparison of the actual furnace outputs with the output matrix; and, based on the comparison, creating an adjusted tunable parameter matrix.
[0019] The respective objects and features of the present invention may be applied jointly or severally in any combination or sub-combination by those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
[0021] FIG. 1 is a diagrammatic illustration of an effluent and temperature estimation technique, in accordance with embodiments of the invention;
[0022] FIG. 2 is a symbolic representation of an example chemical reactor network, in accordance with embodiments of the invention;
[0023] FIG. 3 is a schematic diagram of a pulverized coal furnace to be monitored in accordance with aspects of the invention.
[0024] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
DETAILED DESCRIPTION
[0025] Presently disclosed is a machine-learning-based solution to monitor and predict the temperature and NOx concentration inside a pulverized coal furnace. The disclosed technique is very efficient, quickly generating the predicted values of temperature and concentration of selected species (specifically NOx). The technique furthermore is adaptable to various inputs, including variability in the coal supply over time. Details of the structure of the model and operations in creating the model and predicting algorithm are set forth below.
[0026] An overview of the disclosed effluent and temperature estimation technique, shown as a diagrammatic representation 100 in FIG. 1 , includes a modeling stage 110 and a learning stage 150 . To create the initial model, a customer 112 initially provides technical specifications 114 such as boiler specifications and furnace specifications. The specifications may include furnace geometry, burner locations and various operating parameters of the furnace. A computer modeling technician 116 then formulates a furnace simulator 120 using chemical reactor network techniques 118 . The simulator includes a plurality of ideal chemical reactor modules, including plug flow reactors and perfectly stirred reactors, interconnected by tunable parameters. The computer modeling technician may be guided by a CFD analysis of the furnace based on the specifications. The CRN furnace simulator 120 provides a detailed representation of the emissions formation pathways, and may take into account mixing patterns that were discovered using the CFD analysis of the furnace.
[0027] The chemical reactor network methodology simulates complex chemical mechanisms with a network of ideal reactor models. It can provide significant insight into pollutant formation pathways. Because of its small computational cost, the CRN can be used as tool for analysis of combustion systems by coupling with a flow pattern obtained either from CFD simulation or direct measurement.
[0028] In the learning stage 150 , the furnace simulator 120 is run using a known set of input data and an initial set of tunable parameters 154 . Output from the simulator, including NOx predictions, are input to a machine learning algorithm 156 , together with the input data and the initial set of tunable parameters. The machine learning algorithm compares the simulator output with measured benchmarks resulting from the real inputs represented by the known set of input data. The furnace simulator is then tuned 160 by adjusting the tunable parameters to match the simulator output with the benchmark measurements.
[0029] The resulting system simulates the furnace status more accurately and efficiently than the traditional CRN model. The effectiveness of any CRN model in simulating the temperature and species concentrations inside the furnace is strongly tied to how the ideal reactors in CRN are connected. Those connections have, in the past, been based primarily on technicians' intuition and experience. The presently disclosed technique uses a machine learning approach to tune the connection parameters to improve the estimates made by the network. With that machine learning approach, the CRN model is tuned and available for accurately predicting furnace status output based on customers' input values in a few seconds instead of a few hours for a traditional CRN and a few days for a CFD.
[0030] An example 200 of a CRN model for a natural gas furnace is shown in FIG. 2 . The model comprises several ideal reactor models, including plug flow reactor models 210 , 220 and perfectly stirred reactor models 230 , 240 , 250 . A plug flow reactor model describes a chemical reaction in a continuous, flowing system having a cylindrical geometry. A perfectly stirred reactor model assumes perfect mixing and the contents are assumed to be nearly spatially uniform due to high diffusion rates. The rate of conversion of reactants to products in a perfectly stirred reactor model is controlled by chemical reaction rates and not by mixing processes.
[0031] The plug flow reactor models 210 , 220 and perfectly stirred reactor models 230 , 240 , 250 are interconnected by a plurality of tunable parameters including split ratios and flow rates. For example, the output flow rate m 4 from the perfectly stirred reactor 230 is split according to a split ratio 231 into flows m 4a and m 4b . The tunable parameters are stored in a tunable parameter matrix Z.
[0032] A typical pulverized coal furnace, such as the furnace 300 shown in FIG. 3 , includes one or more coal burners 330 fed by a coal source 310 through a pulverizer 312 . One or more primary air ports 335 provide oxygen at the flame location from a blower or compressor 314 . The furnace may also have one or more secondary air ports such as port 340 supplied by blower 316 . Heat from the burners superheats steam in a heater arrangement 320 .
[0033] Inputs to the CRN model 200 ( FIG. 2 ) include inputs at each coal burner and inputs at each air port. Inputs to the CRN model that can be measured or determined at each coal burner include the volumetric flow rate of the air/fuel mixture, the temperature and the concentration of major compositions in the coal. Inputs to the CRN model that can be measured or determined at each air port include the volumetric flow rate and the temperature of the air.
[0034] The example CRN model 200 therefore also includes a fuel/air input having a flow rate m 1 and a secondary air input having a flow rate m 6 . An input table containing such variables is denoted as a matrix X. Input variables may be included in the input table as follows:
[0000]
At each Coal
At each Air
Input
Burner
Port
Volumetric
Yes
Yes
flow rate
Temperature
Yes
Yes
Concentration
Yes
NA
of major
compositions
of the coal
[0035] The example CRN model 200 further includes an output 270 to the environment. An output table containing output variables is denoted as a matrix Y. The variables may include the following:
[0000]
At each grid
throughout the
Output
furnace
Volumetric flow rate
Yes
Temperature
Yes
Concentration of CO
Yes
and NO x
[0036] The focus of the present disclosure is on a tunable parameter matrix Z, which is the collection of split ratios and flow rates among ideal reactors in the chemical reactor network. The matrix Z may also include tunable volumes of the individual ideal reactors. Based on the variables defined above, several assumptions regarding the reaction simulation system may be made:
1. Coal devolatilization depends on coal composition and heating rate only. 2. Coal distributions are equal for a given set of gas burners. 3. Air is distributed equally among a given set of air ports.
[0040] After generating the furnace status output using the user's input and algorithm parameters using CRN model, a learning algorithm is used to teach the model to map this relationship. With the above assumptions and set-up, the machine learning model predicts the output variables at each grid point in the furnace based on the input variables:
[0000] Y=f ( X, Z )+ε
[0000] The error ε accounts for noise in the system, including measurement errors and process variability. After learning the CRN simulated result, it is possible to find the model f ( ) that maps the furnace input and tunable parameters in the system with the output. The fixed mapping model f ( ) is then used to tune the parameters in Z to match the output result to real measurements. That is to say, find Z* that makes Y*=f (X, Z*), Y* being the benchmark values measured by analysis of the actual process effluent, such as by using a laser spectroscopic device.
[0041] Since the tunable parameters in Z are mostly split ratios in the range of [0, 1] and flow rates and reactor volumes in proper ranges, grid-searching is an effective technique for finding Z*. Grid-searching is an exhaustive searching method in which each dimension of the parameter space is divided into a number of segments. In the presently described application of grid searching, the possible ranges for each split ratio, each flow rate and each reactor volume are divided into segments. Every combination of the parameter values in the given ranges is then tried, to find the combination that has the smallest mean squared error as compared with the benchmark measurement.
[0042] While grid searching has been found to perform well in the presently described technique, it is an exhaustive and therefore potentially expensive method. Alternatives may be employed in cases with particularly complicated chemical reactor networks. For example, a randomized search may be used that randomly samples parameter settings a fixed number of times.
[0043] The process may be repeated, using the tuned parameter matrix Z*, to further refine the results. With the tuned parameter matrix Z*, the CRN model simulates the combustion process in coal furnace more accurately and efficiently than prior CRN models.
[0044] Although various embodiments that incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings. The invention is not limited in its application to the exemplary embodiment details of construction and the arrangement of components set forth in the description or illustrated in the drawings. The exemplary CRN model is are shown by way of illustration and not by way of limitation, to clearly describe certain features and aspects of the present invention set out in greater detail herein. However, the various aspects of the present invention described more fully herein may be applied to various combustion engines to monitor and/or detect the occurrence of combustion anomalies. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
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NOx generation in a coal burning furnace is estimating using a chemical reactor network model. The model is constructed with ideal chemical reactor modules, an input matrix and a tunable parameter matrix defining split ratios and flow rates among the ideal chemical reactor modules. Values in the tunable parameter matrix are learned by first measuring actual furnace outputs of the coal burning furnace for a known set of actual furnace inputs, and then applying the chemical reactor network, including an initially populated tunable parameter matrix, to a populated input matrix representing the known set of actual furnace inputs. The actual furnace outputs are compared with the output matrix, and the tunable parameter matrix is adjusted based on the comparison.
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RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. application Ser. No. 11/847,192, filed Aug. 29, 2007 (now pending), which in turn is a divisional of U.S. application Ser. No. 10/837,525, filed Apr. 29, 2004 (now U.S. Pat. No. 7,279,451), which in turn is a continuation in part of each of U.S. application Ser. No. 10/694,272, filed Oct. 27, 2003 (now U.S. Pat. No. 7,230,146) and U.S. patent application Ser. No. 10/694,273, filed Oct. 27, 2003 (now U.S. Pat. No. 7,534,366), which in turn is related to and claims the priority benefit of U.S. Provisional Application Nos. 60/421,263 and 60/421,435, each of which was filed on Oct. 25, 2002. U.S. patent application Ser. No. 10/837,525, filed Apr. 29, 2004 is also a continuation-in-part of U.S. patent application Ser. No. 10/694,272, filed Oct. 27, 2003 (now U.S. Pat. No. 7,230,146). The disclosure of each of the patent applications and patents identified in the preceding sentence is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to compositions having utility in numerous applications, including particularly refrigeration systems, and to methods and systems utilizing such compositions. In preferred aspects, the present invention is directed to refrigerant compositions comprising at least one multi-fluorinated olefin of the present invention.
BACKGROUND OF THE INVENTION
[0003] Fluorocarbon based fluids have found widespread use in many commercial and industrial applications. For example, fluorocarbon based fluids are frequently used as a working fluid in systems such as air conditioning, heat pump and refrigeration applications. The vapor compression cycle is one of the most commonly used type methods to accomplish cooling or heating in a refrigeration system. The vapor compression cycle usually involves the phase change of the refrigerant from the liquid to the vapor phase through heat absorption at a relatively low pressure and then from the vapor to the liquid phase through heat removal at a relatively low pressure and temperature, compressing the vapor to a relatively elevated pressure, condensing the vapor to the liquid phase through heat removal at this relatively elevated pressure and temperature, and then reducing the pressure to start the cycle over again.
[0004] While the primary purpose of refrigeration is to remove heat from an object or other fluid at a relatively low temperature, the primary purpose of a heat pump is to add heat at a higher temperature relative to the environment.
[0005] Certain fluorocarbons have been a preferred component in many heat exchange fluids, such as refrigerants, for many years in many applications. For, example, fluoroalkanes, such as chlorofluoromethane and chlorofluoroethane derivatives, have gained widespread use as refrigerants in applications including air conditioning and heat pump applications owing to their unique combination of chemical and physical properties. Many of the refrigerants commonly utilized in vapor compression systems are either single components fluids or azeotropic mixtures.
[0006] Concern has increased in recent years about potential damage to the earth's atmosphere and climate, and certain chlorine-based compounds have been identified as particularly problematic in this regard. The use of chlorine-containing compositions (such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and the like) as refrigerants in air-conditioning and refrigeration systems has become disfavored because of the ozone-depleting properties associated with many of such compounds. There has thus been an increasing need for new fluorocarbon and hydrofluorocarbon compounds and compositions that offer alternatives for refrigeration and heat pump applications. For example, it has become desirable to retrofit chlorine-containing refrigeration systems by replacing chlorine-containing refrigerants with non-chlorine-containing refrigerant compounds that will not deplete the ozone layer, such as hydrofluorocarbons (HFCs).
[0007] It is generally considered important, however, that any potential substitute refrigerant must also possess those properties present in many of the most widely used fluids, such as excellent heat transfer properties, chemical stability, low- or no- toxicity, non-flammability and lubricant compatibility, among others.
[0008] Applicants have come to appreciate that lubricant compatibility is of particular importance in many of applications. More particularly, it is highly desirably for refrigeration fluids to be compatible with the lubricant utilized in the compressor unit, used in most refrigeration systems. Unfortunately, many non-chlorine-containing refrigeration fluids, including HFCs, are relatively insoluble and/or immiscible in the types of lubricants used traditionally with CFC's and HFCs, including, for example, mineral oils, alkylbenzenes or poly(alpha-olefins). In order for a refrigeration fluid-lubricant combination to work at a desirable level of efficiently within a compression refrigeration, air-conditioning and/or heat pump system, the lubricant should be sufficiently soluble in the refrigeration liquid over a wide range of operating temperatures. Such solubility lowers the viscosity of the lubricant and allows it to flow more easily throughout the system. In the absence of such solubility, lubricants tend to become lodged in the coils of the evaporator of the refrigeration, air-conditioning or heat pump system, as well as other parts of the system, and thus reduce the system efficiency.
[0009] With regard to efficiency in use, it is important to note that a loss in refrigerant thermodynamic performance or energy efficiency may have secondary environmental impacts through increased fossil fuel usage arising from an increased demand for electrical energy.
[0010] Furthermore, it is generally considered desirably for CFC refrigerant substitutes to be effective without major engineering changes to conventional vapor compression technology currently used with CFC refrigerants.
[0011] Flammability is another important property for many applications. That is, it is considered either important or essential in many applications, including particularly in heat transfer applications, to use compositions, which are non-flammable. Thus, it is frequently beneficial to use in such compositions compounds, which are nonflammable. As used herein, the term “nonflammable” refers to compounds or compositions, which are determined to be nonflammable as determined in accordance with ASTM standard E-681, dated 2002, which is incorporated herein by reference. Unfortunately, many HFCs, which might otherwise be desirable for used in refrigerant compositions are not nonflammable. For example, the fluoroalkane difluoroethane (HFC-152a) and the fluoroalkene 1,1,1-trifluoropropene (HFO-1243zf) are each flammable and therefore not viable for use in many applications.
[0012] Higher fluoroalkenes, that is fluorine-substituted alkenes having at least five carbon atoms, have been suggested for use as refrigerants. U.S. Pat. No. 4,788,352 —Smutny is directed to production of fluorinated C 5 to C 8 compounds having at least some degree of unsaturation. The Smutny patent identifies such higher olefins as being known to have utility as refrigerants, pesticides, dielectric fluids, heat transfer fluids, solvents, and intermediates in various chemical reactions. (See column 1, lines 11-22).
[0013] While the fluorinated olefins described in Smutny may have some level of effectiveness in heat transfer applications, it is believed that such compounds may also have certain disadvantages. For example, some of these compounds may tend to attack substrates, particularly general-purpose plastics such as acrylic resins and ABS resins. Furthermore, the higher olefinic compounds described in Smutny may also be undesirable in certain applications because of the potential level of toxicity of such compounds which may arise as a result of pesticide activity noted in Smutny. Also, such compounds may have a boiling point, which is too high to make them useful as a refrigerant in certain applications.
[0014] Bromofluoromethane and bromochlorofluoromethane derivatives, particularly bromotrifluoromethane (Halon 1301) and bromochlorodifluoromethane (Halon 1211) have gained widespread use as fire extinguishing agents in enclosed areas such as airplane cabins and computer rooms. However, the use of various halons is being phased out due to their high ozone depletion. Moreover, as halons are frequently used in areas where humans are present, suitable replacements must also be safe to humans at concentrations necessary to suppress or extinguish fire.
[0015] Applicants have thus come to appreciate a need for compositions, and particularly heat transfer compositions, fire extinguishing/suppression compositions, blowing agents, solvent compositions, and compatabilizing agents, that are potentially useful in numerous applications, including vapor compression heating and cooling systems and methods, while avoiding one or more of the disadvantages noted above.
SUMMARY
[0016] Applicants have found that the above-noted need, and other needs, can be satisfied by compositions comprising one or more C3 or C4 fluoroalkenes, preferably compounds having Formula I as follows:
XCF z R 3-z (I)
where X is a C 2 or a C 3 unsaturated, substituted or unsubstituted, alkyl radical, each R is independently Cl, F, Br, I or H, and z is 1 to 3. Highly preferred among the compounds of Formula I are the cis- and trans- isomers of 1, 3, 3, 3-tetrafluoropropene (HFO-1234ze)
[0018] The present invention provides also methods and systems which utilize the compositions of the present invention, including methods and systems for heat transfer, foam blowing, solvating, flavor and fragrance extraction and/or delivery, and aerosol generation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] The Compositions
[0020] The present invention is directed to compositions comprising at least one fluoroalkene containing from 3 to 4 carbon atoms, preferably three carbon atoms, and at least one carbon-carbon double bond. The fluoroalkene compounds of the present invention are sometimes referred to herein for the purpose of convenience as hydrofluoro-olefins or “HFOs” if they contain at least one hydrogen. Although it is contemplated that the HFOs of the present invention may contain two carbon -- carbon double bonds, such compounds at the present time are not considered to be preferred.
[0021] As mentioned above, the present compositions comprise one or more compounds in accordance with Formula I. In preferred embodiments, the compositions include compounds of Formula II below:
[0000]
[0000] where each R is independently Cl, F, Br, I or H
R′ is (CR 2 ) n Y, Y is CRF 2 and n is 0 or 1.
[0025] In highly preferred embodiments, Y is CF 3 , n is 0 and at least one of the remaining Rs is F.
[0026] Applicants believe that, in general, the compounds of the above identified Formulas I and II are generally effective and exhibit utility in refrigerant compositions, blowing agent compositions, compatibilizers, aerosols, propellants, fragrances, flavor formulations, and solvent compositions of the present invention. However, applicants have surprisingly and unexpectedly found that certain of the compounds having a structure in accordance with the formulas described above exhibit a highly desirable low level of toxicity compared to other of such compounds. As can be readily appreciated, this discovery is of potentially enormous advantage and benefit for the formulation of not only refrigerant compositions, but also any and all compositions, which would otherwise contain relatively toxic compounds satisfying the formulas described above. More particularly, applicants believe that a relatively low toxicity level is associated with compounds of Formula II, preferably wherein Y is CF 3 , wherein at least one R on the unsaturated terminal carbon is H, and at least one of the remaining Rs is F. Applicants believe also that all structural, geometric and stereoisomers of such compounds are effective and of beneficially low toxicity.
[0027] In highly preferred embodiments, especially embodiments comprising the low toxicity compounds described above, n is zero. In certain highly preferred embodiments the compositions of the present invention comprise one or more tetrafluoropropenes. The term “HFO-1234” is used herein to refer to all tetrafluoropropenes. Among the tetrafluoropropenes, both cis- and trans-1, 3, 3, 3-tetrafluoropropene (HFO-1234ze) are particularly preferred. The term HFO-1234ze is used herein generically to refer to 1, 3, 3, 3-tetrafluoropropene, independent of whether it is the cis- or trans- form. The terms “cisHFO-1234ze” and “transHFO-1234ze” are used herein to describe the cis- and trans- forms of 1, 3, 3, 3-tetrafluoropropene respectively. The term “HFO-1234ze” therefore includes within its scope cisHFO-1234ze, transHFO-1234ze, and all combinations and mixtures of these.
[0028] Although the properties of cisHFO-1234ze and transHFO-1234ze differ in at least some respects, it is contemplated that each of these compounds is adaptable for use, either alone or together with other compounds including its stereoisomer, in connection with each of the applications, methods and systems described herein. For example, while transHFO-1234ze may be preferred for use in certain refrigeration systems because of its relatively low boiling point (−19° C.), it is nevertheless contemplated that cisHFO-1234ze, with a boiling point of +9° C., also has utility in certain refrigeration systems of the present invention. Accordingly, it is to be understood that the terms “HFO-1234ze” and 1, 3, 3, 3-tetrafluoropropene refer to both stereo isomers, and the use of this term is intended to indicate that each of the cis-and trans- forms applies and/or is useful for the stated purpose unless otherwise indicated.
[0029] HFO-1234 compounds are known materials and are listed in Chemical Abstracts databases. The production of fluoropropenes such as CF 3 CH=CH 2 by catalytic vapor phase fluorination of various saturated and unsaturated halogen-containing C 3 compounds is described in U.S. Pat. Nos. 2,889,379; 4,798,818 and 4,465,786, each of which is incorporated herein by reference. EP 974,571, also incorporated herein by reference, discloses the preparation of 1,1,1,3-tetrafluoropropene by contacting 1,1,1,3,3-pentafluoropropane (HFC-245fa) in the vapor phase with a chromium-based catalyst at elevated temperature, or in the liquid phase with an alcoholic solution of KOH, NaOH, Ca(OH) 2 or Mg(OH) 2 . In addition, methods for producing compounds in accordance with the present invention are described generally in connection with pending United States Patent Application entitled “Process for Producing Fluoropropenes” bearing attorney docket number (H0003789 (26267)), which is also incorporated herein by reference.
[0030] The present compositions, particularly those comprising HFO-1234ze, are believed to possess properties that are advantageous for a number of important reasons. For example, applicants believe, based at least in part on mathematical modeling, that the fluoroolefins of the present invention will not have a substantial negative affect on atmospheric chemistry, being negligible contributors to ozone depletion in comparison to some other halogenated species. The preferred compositions of the present invention thus have the advantage of not contributing substantially to ozone depletion. The preferred compositions also do not contribute substantially to global warming compared to many of the hydrofluoroalkanes presently in use.
[0031] In certain preferred forms, compositions of the present invention have a Global Warming Potential (GWP) of not greater than about 1000, more preferably not greater than about 500, and even more preferably not greater than about 150. In certain embodiments, the GWP of the present compositions is not greater than about 100 and even more preferably not greater than about 75. As used herein, “GWP” is measured relative to that of carbon dioxide and over a 100-year time horizon, as defined in “The Scientific Assessment of Ozone Depletion, 2002, a report of the World Meteorological Association's Global Ozone Research and Monitoring Project,” which is incorporated herein by reference.
[0032] In certain preferred forms, the present compositions also preferably have an Ozone Depletion Potential (ODP) of not greater than 0.05, more preferably not greater than 0.02 and even more preferably about zero. As used herein, “ODP” is as defined in “The Scientific Assessment of Ozone Depletion, 2002, A report of the World Meteorological Association's Global Ozone Research and Monitoring Project,” which is incorporated herein by reference.
[0033] The amount of the Formula I compounds, particularly HFO-1234, contained in the present compositions can vary widely, depending the particular application, and compositions containing more than trace amounts and less than 100% of the compound are within broad the scope of the present invention. Moreover, the compositions of the present invention can be azeotropic, azeotrope-like or non-azeotropic. In preferred embodiments, the present compositions comprise HFO-1234, preferably HFO-1234ze, in amounts from about 5% by weight to about 99% by weight, and even more preferably from about 5% to about 95%. Many additional compounds may be included in the present compositions, and the presence of all such compounds is within the broad scope of the invention. In certain preferred embodiments, the present compositions include, in addition to HFO-1234ze, one or more of the following:
Difluoromethane (HFC-32) Pentafluoroethane (HFC-125) 1,1,2,2-tetrafluoroethane (HFC-134) 1,1,1,2-Tetrafluoroethane (HFC-134a) Difluoroethane (HFC-152a) 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea) 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) 1,1,1,3,3-pentafluoropropane (HFC-245fa) 1,1,1,3,3-pentafluorobutane (HFC-365mfc) water CO 2
The relative amount of any of the above noted components, as well as any additional components which may be included in present compositions, can vary widely within the general broad scope of the present invention according to the particular application for the composition, and all such relative amounts are considered to be within the scope hereof.
[0045] Heat Transfer Compositions
[0046] Although it is contemplated that the compositions of the present invention may include the compounds of the present invention in widely ranging amounts, it is generally preferred that refrigerant compositions of the present invention comprise compound(s) in accordance with Formula I, more preferably in accordance with Formula II, and even more preferably HFO-1234ze, in an amount that is at least about 50% by weight, and even more preferably at least about 70% by weight, of the composition. In many embodiments, it is preferred that the heat transfer compositions of the present invention comprise transHFO-1234ze. In certain preferred embodiments, the heat transfer compositions of the present invention comprise a combination of cisHFO-1234ze and transHFO1234ze in a cis:trans weight ratio of from about 1:99 to about 10:99, more preferably from about 1:99 to about 5:95, and even more preferably from about 1:99 to about 3:97.
[0047] The compositions of the present invention may include other components for the purpose of enhancing or providing certain functionality to the composition, or in some cases to reduce the cost of the composition. For example, refrigerant compositions according to the present invention, especially those used in vapor compression systems, include a lubricant, generally in amounts of from about 30 to about 50 percent by weight of the composition. Furthermore, the present compositions may also include a compatibilizer, such as propane, for the purpose of aiding compatibility and/or solubility of the lubricant. Such compatibilizers, including propane, butanes and pentanes, are preferably present in amounts of from about 0.5 to about 5 percent by weight of the composition. Combinations of surfactants and solubilizing agents may also be added to the present compositions to aid oil solubility, as disclosed by U.S. Pat. No. 6,516,837, the disclosure of which is incorporated by reference. Commonly used refrigeration lubricants such as Polyol Esters (POEs) and Poly Alkylene Glycols (PAGs), silicone oil, mineral oil, alkyl benzenes (ABs) and poly(alpha-olefin) (PAO) that are used in refrigeration machinery with hydrofluorocarbon (HFC) refrigerants may be used with the refrigerant compositions of the present invention.
[0048] Many existing refrigeration systems are currently adapted for use in connection with existing refrigerants, and the compositions of the present invention are believed to be adaptable for use in many of such systems, either with or without system modification. In many applications the compositions of the present invention may provide an advantage as a replacement in systems, which are currently based on refrigerants having a relatively high capacity. Furthermore, in embodiments where it is desired to use a lower capacity refrigerant composition of the present invention, for reasons of cost for example, to replace a refrigerant of higher capacity, such embodiments of the present compositions provide a potential advantage. Thus, It is preferred in certain embodiments to use compositions of the present invention, particularly compositions comprising a substantial proportion of, and in some embodiments consisting essentially of transHFO-1234ze, as a replacement for existing refrigerants, such as HFC-134a. In certain applications, the refrigerants of the present invention potentially permit the beneficial use of larger displacement compressors, thereby resulting in better energy efficiency than other refrigerants, such as HFC-134a. Therefore the refrigerant compositions of the present invention, particularly compositions comprising transHFP-1234ze, provide the possibility of achieving a competitive advantage on an energy basis for refrigerant replacement applications.
[0049] It is contemplated that the compositions of the present, including particularly those comprising HFO-1234ze, also have advantage (either in original systems or when used as a replacement for refrigerants such as R-12 and R-500), in chillers typically used in connection with commercial air conditioning systems. In certain of such embodiments it is preferred to including in the present HFO-1234ze compositions from about 0.5 to about 5% of a flammability suppressant, such as CF3I.
[0050] The present methods, systems and compositions are thus adaptable for use in connection with automotive air conditioning systems and devices, commercial refrigeration systems and devices, chillers, residential refrigerator and freezers, general air conditioning systems, heat pumps, and the like.
[0051] Blowing Agents, Foams and Foamable Compositions
[0052] Blowing agents may also comprise or constitute one or more of the present compositions. As mentioned above, the compositions of the present invention may include the compounds of the present invention in widely ranging amounts. It is generally preferred, however, that for preferred compositions for use as blowing agents in accordance with the present invention, compound(s) in accordance with Formula I, and even more preferably Formula II, are present in an amount that is at least about 5 by weight, and even more preferably at least about 15% by weight, of the composition. In certain preferred embodiments, the blowing agent compositions of the present invention and include, in addition to HFO-1234 (preferably HFO-1234ze) one or more of the following components as a co-blowing agent, filler, vapor pressure modifier, or for any other purpose:
Difluoromethane (HFC-32) Pentafluoroethane (HFC-125) 1,1,2,2-tetrafluoroethane (HFC-134) 1,1,1,2-Tetrafluoroethane (HFC-134a) Difluoroethane (HFC-152a) 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea) 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) 1,1,1,3,3-pentafluoropropane (HFC-245fa) 1,1,1,3,3-pentafluorobutane (HFC-365mfc) water CO 2
it is contemplated that the blowing agent compositions of the present invention may comprise cisHFO-1234ze, transHFO1234ze or combinations thereof. In certain preferred embodiments, the blowing agent composition of the present invention comprise his a combination of cisHFO-1234ze and transHFO1234ze in a cis:trans weight ratio of from about 1:99 to about 10:99, and even more preferably from about 1:99 to about 5:95.
[0064] In other embodiments, the invention provides foamable compositions, and preferably polyurethane, polyisocyanurate and extruded thermoplastic foam compositions, prepared using the compositions of the present invention. In such foam embodiments, one or more of the present compositions are included as or part of a blowing agent in a foamable composition, which composition preferably includes one or more additional components capable of reacting and/or foaming under the proper conditions to form a foam or cellular structure, as is well known in the art. The invention also relates to foam, and preferably closed cell foam, prepared from a polymer foam formulation containing a blowing agent comprising the compositions of the invention. In yet other embodiments, the invention provides foamable compositions comprising thermoplastic or polyolefin foams, such as polystyrene (PS), polyethylene (PE), polypropylene (PP) and polyethyleneterpthalate (PET) foams, preferably low-density foams.
[0065] In certain preferred embodiments, dispersing agents, cell stabilizers, surfactants and other additives may also be incorporated into the blowing agent compositions of the present invention. Surfactants are optionally but preferably added to serve as cell stabilizers. Some representative materials are sold under the names of DC-193, B-8404, and L-5340 which are, generally, polysiloxane polyoxyalkylene block co-polymers such as those disclosed in U.S. Pat. Nos. 2,834,748, 2,917,480, and 2,846,458, each of which is incorporated herein by reference. Other optional additives for the blowing agent mixture may include flame retardants such as tri(2-chloroethyl)phosphate, tri(2-chloropropyl)phosphate, tri(2,3-dibromopropyl)-phosphate, tri(1,3-dichloropropyl) phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, and the like.
[0066] Propellant and Aerosol Compositions
[0067] In another aspect, the present invention provides propellant compositions comprising or consisting essentially of a composition of the present invention, such propellant composition preferably being a sprayable composition. The propellant compositions of the present invention preferably comprise a material to be sprayed and a propellant comprising, consisting essentially of, or consisting of a composition in accordance with the present invention. Inert ingredients, solvents, and other materials may also be present in the sprayable mixture. Preferably, the sprayable composition is an aerosol. Suitable materials to be sprayed include, without limitation, cosmetic materials such as deodorants, perfumes, hair sprays, cleansers, and polishing agents as well as medicinal materials such as anti-asthma components, anti-halitosis components and any other medication or the like, including preferably any other medicament or agent intended to be inhaled. The medicament or other therapeutic agent is preferably present in the composition in a therapeutic amount, with a substantial portion of the balance of the composition comprising a compound of Formula I of the present invention, preferably HFO-1234, and even more preferably HFO-1234ze.
[0068] Aerosol products for industrial, consumer or medical use typically contain one or more propellants along with one or more active ingredients, inert ingredients or solvents. The propellant provides the force that expels the product in aerosolized form. While some aerosol products are propelled with compressed gases like carbon dioxide, nitrogen, nitrous oxide and even air, most commercial aerosols use liquefied gas propellants. The most commonly used liquefied gas propellants are hydrocarbons such as butane, isobutane, and propane. Dimethyl ether and HFC-152a (1, 1-difluoroethane) are also used, either alone or in blends with the hydrocarbon propellants. Unfortunately, all of these liquefied gas propellants are highly flammable and their incorporation into aerosol formulations will often result in flammable aerosol products.
[0069] Applicants have come to appreciate the continuing need for nonflammable, liquefied gas propellants with which to formulate aerosol products. The present invention provides compositions of the present invention, particularly and preferably compositions comprising HFO-1234, and even more preferably HFO-1234ze, for use in certain industrial aerosol products, including for example spray cleaners, lubricants, and the like, and in medicinal aerosols, including for example to deliver medications to the lungs or mucosal membranes. Examples of this includes metered dose inhalers (MDIs) for the treatment of asthma and other chronic obstructive pulmonary diseases and for delivery of medicaments to accessible mucous membranes or intranasally. The present invention thus includes methods for treating ailments, diseases and similar health related problems of an organism (such as a human or animal) comprising applying a composition of the present invention containing a medicament or other therapeutic component to the organism in need of treatment. In certain preferred embodiments, the step of applying the present composition comprises providing a MDI containing the composition of the present invention (for example, introducing the composition into the MDI) and then discharging the present composition from the MDI.
[0070] The compositions of the present invention, particularly compositions comprising or consisting essentially of HFO-1234ze, are capable of providing nonflammable, liquefied gas propellant and aerosols that do not contribute substantially to global warming. The present compositions can be used to formulate a variety of industrial aerosols or other sprayable compositions such as contact cleaners, dusters, lubricant sprays, and the like, and consumer aerosols such as personal care products, household products and automotive products. HFO-1234ze is particularly preferred for use as an important component of propellant compositions for in medicinal aerosols such as metered dose inhalers. The medicinal aerosol and/or propellant and/or sprayable compositions of the present invention in many applications include, in addition to compound of formula (I) or (II) (preferably HFO-1234ze), a medicament such as a beta-agonist, a corticosteroid or other medicament, and, optionally, other ingredients, such as surfactants, solvents, other propellants, flavorants and other excipients. The compositions of the present invention, unlike many compositions previously used in these applications, have good environmental properties and are not considered to be potential contributors to global warming. The present compositions therefore provide in certain preferred embodiments substantially nonflammable, liquefied gas propellants having very low Global Warming potentials.
[0071] Flavorants and Fragrances
[0072] The compositions of the present invention also provide advantage when used as part of, and in particular as a carrier for, flavor formulations and fragrance formulations. The suitability of the present compositions for this purpose is demonstrated by a test procedure in which 0.39 grams of Jasmone were put into a heavy walled glass tube. 1.73 grams of R-1234ze were added to the glass tube. The tube was then frozen and sealed. Upon thawing the tube, it was found that the mixture had one liquid phase. The solution contained 20 wt. % Jasome and 80 wt. % R-1234ze, thus establishing its favorable use as a carrier or part of delivery system for flavor formulations, in aerosol and other formulations. It also establishes its potential as an extractant of fragrances, including from plant matter.
[0073] Methods and Systems
[0074] The compositions of the present invention are useful in connection with numerous methods and systems, including as heat transfer fluids in methods and systems for transferring heat, such as refrigerants used in refrigeration, air conditioning and heat pump systems. The present compositions are also advantageous for in use in systems and methods of generating aerosols, preferably comprising or consisting of the aerosol propellant in such systems and methods. Methods of forming foams and methods of extinguishing and suppressing fire are also included in certain aspects of the present invention. The present invention also provides in certain aspects methods of removing residue from articles in which the present compositions are used as solvent compositions in such methods and systems.
[0075] Heat Transfer Methods
[0076] The preferred heat transfer methods generally comprise providing a composition of the present invention and causing heat to be transferred to or from the composition changing the phase of the composition. For example, the present methods provide cooling by absorbing heat from a fluid or article, preferably by evaporating the present refrigerant composition in the vicinity of the body or fluid to be cooled to produce vapor comprising the present composition. Preferably the methods include the further step of compressing the refrigerant vapor, usually with a compressor or similar equipment to produce vapor of the present composition at a relatively elevated pressure. Generally, the step of compressing the vapor results in the addition of heat to the vapor, thus causing an increase in the temperature of the relatively high-pressure vapor. Preferably, the present methods include removing from this relatively high temperature, high pressure vapor at least a portion of the heat added by the evaporation and compression steps. The heat removal step preferably includes condensing the high temperature, high-pressure vapor while the vapor is in a relatively high-pressure condition to produce a relatively high-pressure liquid comprising a composition of the present invention. This relatively high-pressure liquid preferably then undergoes a nominally isoenthalpic reduction in pressure to produce a relatively low temperature, low-pressure liquid. In such embodiments, it is this reduced temperature refrigerant liquid which is then vaporized by heat transferred from the body or fluid to be cooled.
[0077] In another process embodiment of the invention, the compositions of the invention may be used in a method for producing heating which comprises condensing a refrigerant comprising the compositions in the vicinity of a liquid or body to be heated. Such methods, as mentioned hereinbefore, frequently are reverse cycles to the refrigeration cycle described above.
[0078] Foam Blowing Methods
[0079] One embodiment of the present invention relates to methods of forming foams, and preferably polyurethane and polyisocyanurate foams. The methods generally comprise providing a blowing agent composition of the present inventions, adding (directly or indirectly) the blowing agent composition to a foamable composition, and reacting the foamable composition under the conditions effective to form a foam or cellular structure, as is well known in the art. Any of the methods well known in the art, such as those described in “Polyurethanes Chemistry and Technology,” Volumes I and II, Saunders and Frisch, 1962, John Wiley and Sons, New York, N.Y., which is incorporated herein by reference, may be used or adapted for use in accordance with the foam embodiments of the present invention. In general, such preferred methods comprise preparing polyurethane or polyisocyanurate foams by combining an isocyanate, a polyol or mixture of polyols, a blowing agent or mixture of blowing agents comprising one or more of the present compositions, and other materials such as catalysts, surfactants, and optionally, flame retardants, colorants, or other additives.
[0080] It is convenient in many applications to provide the components for polyurethane or polyisocyanurate foams in pre-blended formulations. Most typically, the foam formulation is pre-blended into two components. The isocyanate and optionally certain surfactants and blowing agents comprise the first component, commonly referred to as the “A” component. The polyol or polyol mixture, surfactant, catalysts, blowing agents, flame retardant, and other isocyanate reactive components comprise the second component, commonly referred to as the “B” component. Accordingly, polyurethane or polyisocyanurate foams are readily prepared by bringing together the A and B side components either by hand mix for small preparations and, preferably, machine mix techniques to form blocks, slabs, laminates, pour-in-place panels and other items, spray applied foams, froths, and the like. Optionally, other ingredients such as fire retardants, colorants, auxiliary blowing agents, and even other polyols can be added as a third stream to the mix head or reaction site. Most preferably, however, they are all incorporated into one B-component as described above.
[0081] It is also possible to produce thermoplastic foams using the compositions of the invention. For example, conventional polystyrene and polyethylene formulations may be combined with the compositions in a conventional manner to produce rigid foams.
[0082] Cleaning Methods
[0083] The present invention also provides methods of removing containments from a product, part, component, substrate, or any other article or portion thereof by applying to the article a composition of the present invention. For the purposes of convenience, the term “article” is used herein to refer to all such products, parts, components, substrates, and the like and is further intended to refer to any surface or portion thereof. Furthermore, the term “contaminant” is intended to refer to any unwanted material or substance present on the article, even if such substance is placed on the article intentionally. For example, in the manufacture of semiconductor devices it is common to deposit a photoresist material onto a substrate to form a mask for the etching operation and to subsequently remove the photoresist material from the substrate. The term “contaminant” as used herein is intended to cover and encompass such a photo resist material.
[0084] Preferred methods of the present invention comprise applying the present composition to the article. Although it is contemplated that numerous and varied cleaning techniques can employ the compositions of the present invention to good advantage, it is considered to be particularly advantageous to use the present compositions in connection with supercritical cleaning techniques. Supercritical cleaning is disclosed in U.S. Pat. No. 6,589,355, which is assigned to the assignee of the present invention and incorporated herein by reference. For supercritical cleaning applications, is preferred in certain embodiments to include in the present cleaning compositions, in addition to the HFO-1234 (preferably HFO-1234ze), one or more additional components, such as CO 2 and other additional components known for use in connection with supercritical cleaning applications. It may also be possible and desirable in certain embodiments to use the present cleaning compositions in connection with particular vapor degreasing and solvent cleaning methods.
[0085] Flammability Reduction Methods
[0086] According to certain other preferred embodiments, the present invention provides methods for reducing the flammability of fluids, said methods comprising adding a compound or composition of the present invention to said fluid. The flammability associated with any of a wide range of otherwise flammable fluids may be reduced according to the present invention. For example, the flammability associated with fluids such as ethylene oxide, flammable hydrofluorocarbons and hydrocarbons, including: HFC-152a, 1,1,1-trifluoroethane (HFC-143a), difluoromethane (HFC-32), propane, hexane, octane, and the like can be reduced according to the present invention. For the purposes of the present invention, a flammable fluid may be any fluid exhibiting flammability ranges in air as measured via any standard conventional test method, such as ASTM E-681, and the like.
[0087] Any suitable amounts of the present compounds or compositions may be added to reduce flammability of a fluid according to the present invention. As will be recognized by those of skill in the art, the amount added will depend, at least in part, on the degree to which the subject fluid is flammable and the degree to which it is desired to reduce the flammability thereof. In certain preferred embodiments, the amount of compound or composition added to the flammable fluid is effective to render the resulting fluid substantially non-flammable.
[0088] Flame Suppression Methods
[0089] The present invention further provides methods of suppressing a flame, said methods comprising contacting a flame with a fluid comprising a compound or composition of the present invention. Any suitable methods for contacting the flame with the present composition may be used. For example, a composition of the present invention may be sprayed, poured, and the like onto the flame, or at least a portion of the flame may be immersed in the composition. In light of the teachings herein, those of skill in the art will be readily able to adapt a variety of conventional apparatus and methods of flame suppression for use in the present invention.
[0090] Sterilization Methods
[0091] Many articles, devices and materials, particularly for use in the medical field, must be sterilized prior to use for the health and safety reasons, such as the health and safety of patients and hospital staff. The present invention provides methods of sterilizing comprising contacting the articles, devices or material to be sterilized with a compound or composition of the present invention comprising a compound of Formula I, preferably HFO-1234, and even more preferably HFO-1234ze, in combination with one or more sterilizing agents. While many sterilizing agents are known in the art and are considered to be adaptable for use in connection with the present invention, in certain preferred embodiments sterilizing agent comprises ethylene oxide, formaldehyde, hydrogen peroxide, chlorine dioxide, ozone and combinations of these. In certain embodiments, ethylene oxide is the preferred sterilizing agent. Those skilled in the art, in view of the teachings contained herein, will be able to readily determine the relative proportions of sterilizing agent and the present compound(s) to be used in connection with the present sterilizing compositions and methods, and all such ranges are within the broad scope hereof. As is known to those skilled in the art, certain sterilizing agents, such as ethylene oxide, are relatively flammable components, and the compound(s) in accordance with the present invention are included in the present compositions in amounts effective, together with other components present in the composition, to reduce the flammability of the sterilizing composition to acceptable levels.
[0092] The sterilization methods of the present invention may be either high or low-temperature sterilization of the present invention involves the use of a compound or composition of the present invention at a temperature of from about 250° F. to about 270° F., preferably in a substantially sealed chamber. The process can be completed usually in less than about 2 hours. However, some articles, such as plastic articles and electrical components, cannot withstand such high temperatures and require low-temperature sterilization. In low temperature sterilization methods, the article to be sterilized is exposed to a fluid comprising a composition of the present invention at a temperature of from about room temperature to about 200° F., more preferably at a temperature of from about room temperature to about 100° F.
[0093] The low-temperature sterilization of the present invention is preferably at least a two-step process performed in a substantially sealed, preferably air tight, chamber. In the first step (the sterilization step), the articles having been cleaned and wrapped in gas permeable bags are placed in the chamber. Air is then evacuated from the chamber by pulling a vacuum and perhaps by displacing the air with steam. In certain embodiments, it is preferable to inject steam into the chamber to achieve a relative humidity that ranges preferably from about 30% to about 70%. Such humidities may maximize the sterilizing effectiveness of the sterilant, which is introduced into the chamber after the desired relative humidity is achieved. After a period of time sufficient for the sterilant to permeate the wrapping and reach the interstices of the article, the sterilant and steam are evacuated from the chamber.
[0094] In the preferred second step of the process (the aeration step), the articles are aerated to remove sterilant residues. Removing such residues is particularly important in the case of toxic sterilants, although it is optional in those cases in which the substantially non-toxic compounds of the present invention are used. Typical aeration processes include air washes, continuous aeration, and a combination of the two. An air wash is a batch process and usually comprises evacuating the chamber for a relatively short period, for example, 12 minutes, and then introducing air at atmospheric pressure or higher into the chamber. This cycle is repeated any number of times until the desired removal of sterilant is achieved. Continuous aeration typically involves introducing air through an inlet at one side of the chamber and then drawing it out through an outlet on the other side of the chamber by applying a slight vacuum to the outlet. Frequently, the two approaches are combined. For example, a common approach involves performing air washes and then an aeration cycle.
EXAMPLES
[0095] The following examples are provided for the purpose of illustrating the present invention but without limiting the scope thereof.
EXAMPLE 1
[0096] The coefficient of performance (COP) is a universally accepted measure of refrigerant performance, especially useful in representing the relative thermodynamic efficiency of a refrigerant in a specific heating or cooling cycle involving evaporation or condensation of the refrigerant. In refrigeration engineering, this term expresses the ratio of useful refrigeration to the energy applied by the compressor in compressing the vapor. The capacity of a refrigerant represents the amount of cooling or heating it provides and provides some measure of the capability of a compressor to pump quantities of heat for a given volumetric flow rate of refrigerant. In other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling or heating power. One means for estimating COP of a refrigerant at specific operating conditions is from the thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques (see for example, R. C. Downing, FLUOROCARBON REFRIGERANTS HANDBOOK, Chapter 3, Prentice-Hall, 1988).
[0097] A refrigeration/air conditioning cycle system is provided where the condenser temperature is about 150° F. and the evaporator temperature is about −35° F. under nominally isentropic compression with a compressor inlet temperature of about 50° F. COP is determined for several compositions of the present invention over a range of condenser and evaporator temperatures and reported in Table I below, based upon HFC-134a having a COP value of 1.00, a capacity value of 1.00 and a discharge temperature of 175° F.
[0000]
TABLE I
DISCHARGE
REFRIGERANT
Relative
TEMPERATURE
COMPOSITION
Relative COP
CAPACITY
(° F.)
HFO 1225ye
1.02
0.76
158
HFO trans-1234ze
1.04
0.70
165
HFO cis-1234ze
1.13
0.36
155
HFO 1234yf
0.98
1.10
168
[0098] This example shows that certain of the preferred compounds for use with the present compositions each have a better energy efficiency than HFC-134a (1.02, 1.04 and 1.13 compared to 1.00) and the compressor using the present refrigerant compositions will produce discharge temperatures (158, 165 and 155 compared to 175), which is advantageous since such result will likely leading to reduced maintenance problems.
Example 2
[0099] The miscibility of HFO-1225ye and HFO-1234ze with various refrigeration lubricants is tested. The lubricants tested are mineral oil (C3), alkyl benzene (Zerol 150), ester oil (Mobil EAL 22 cc and Solest 120), polyalkylene glycol (PAG) oil (Goodwrench Refrigeration Oil for 134a systems), and a poly(alpha-olefin) oil (CP-6005-100). For each refrigerant/oil combination, three compositions are tested, namely 5, 20 and 50 weight percent of lubricant, with the balance of each being the compound of the present invention being tested
[0100] The lubricant compositions are placed in heavy-walled glass tubes. The tubes are evacuated, the refrigerant compound in accordance with the present invention is added, and the tubes are then sealed. The tubes are then put into an air bath environmental chamber, the temperature of which is varied from about −50° C. to 70° C. At roughly 10° C. intervals, visual observations of the tube contents are made for the existence of one or more liquid phases. In a case where more than one liquid phase is observed, the mixture is reported to be immiscible. In a case where there is only one liquid phase observed, the mixture is reported to be miscible. In those cases where two liquid phases were observed, but with one of the liquid phases occupying only a very small volume, the mixture is reported to be partially miscible.
[0101] The polyalkylene glycol and ester oil lubricants were judged to be miscible in all tested proportions over the entire temperature range, except that for the HFO-1225ye mixtures with polyalkylene glycol, the refrigerant mixture was found to be immiscible over the temperature range of −50° C. to −30° C. and to be partially miscible over from −20 to 50° C. At 50 weight percent concentration of the PAG in refrigerant and at 60° , the refrigerant/PAG mixture was miscible. At 70° C., it was miscible from 5 weight percent lubricant in refrigerant to 50 weight percent lubricant in refrigerant.
Example 3
[0102] The compatibility of the refrigerant compounds and compositions of the present invention with PAG lubricating oils while in contact with metals used in refrigeration and air conditioning systems is tested at 350° C., representing conditions much more severe than are found in many refrigeration and air conditioning applications.
[0103] Aluminum, copper and steel coupons are added to heavy walled glass tubes. Two grams of oil are added to the tubes. The tubes are then evacuated and one gram of refrigerant is added. The tubes are put into an oven at 350° F. for one week and visual observations are made. At the end of the exposure period, the tubes are removed.
[0104] This procedure was done for the following combinations of oil and the compound of the present invention:
a) HFO-1234ze and GM Goodwrench PAG oil b) HFO1243 zf and GM Goodwrench oil PAG oil c) HFO-1234ze and MOPAR-56 PAG oil d) HFO-1243 zf and MOPAR-56 PAG oil e) HFO-1225 ye and MOPAR-56 PAG oil.
[0110] In all cases, there is minimal change in the appearance of the contents of the tube. This indicates that the refrigerant compounds and compositions of the present invention are stable in contact with aluminum, steel and copper found in refrigeration and air conditioning systems, and the types of lubricating oils that are likely to be included in such compositions or used with such compositions in these types of systems.
Comparative Example
[0111] Aluminum, copper and steel coupons are added to a heavy walled glass tube with mineral oil and CFC-12 and heated for one week at 350° C., as in Example 3. At the end of the exposure period, the tube is removed and visual observations are made. The liquid contents are observed to turn black, indicating there is severe decomposition of the contents of the tube.
[0112] CFC-12 and mineral oil have heretofore been the combination of choice in many refrigerant systems and methods. Thus, the refrigerant compounds and compositions of the present invention possess significantly better stability with many commonly used lubricating oils than the widely used prior art refrigerant-lubricating oil combination.
Example 4
[0113] Polyol Foam
[0114] This example illustrates the use of blowing agent in accordance with one of the preferred embodiments of the present invention, namely the use of HFO-1234ze, and the production of polyol foams in accordance with the present invention. The components of a polyol foam formulation are prepared in accordance with the following table:
[0000]
PBW
Polyol Component *
Voranol 490
50
Voranol 391
50
Water
0.5
B-8462 (surfactant)
2.0
Polycat 8
0.3
Polycat 41
3.0
HFO-1234ze
35
Total
140.8
Isocyanate
M-20S
123.8 Index 1.10
* Voranol 490 is a sucrose-based polyol and Voranol 391 is a toluene diamine based polyol, and each are from Dow Chemical. B-8462 is a surfactant available from Degussa-Goldschmidt. Polycat catalysts are tertiary amine based and are available from Air Products. Isocyanate M-20S is a product of Bayer LLC.
[0115] The foam is prepared by first mixing the ingredients thereof, but without the addition of blowing agent. Two Fisher-Porter tubes are each filled with about 52.6 grams of the polyol mixture (without blowing agent) and sealed and placed in a refrigerator to cool and form a slight vacuum. Using gas burets, about 17.4 grams of HFO-1234ze are added to each tube, and the tubes are then placed in an ultrasound bath in warm water and allowed to sit for 30 minutes. The solution produced is hazy, a vapor pressure measurement at room temperature indicates a vapor pressure of about 70 psig, indicating that the blowing agent is not in solution. The tubes are then placed in a freezer at 27° F. for 2 hours. The vapor pressure was again measured and found to be 14-psig. The isocyanate mixture, about 87.9 grams, is placed into a metal container and placed in a refrigerator and allowed to cool to about 50° F. The polyol tubes were then opened and weighed into a metal mixing container (about 100 grams of polyol blend are used). The isocyanate from the cooled metal container is then immediately poured into the polyol and mixed with an air mixer with double propellers at 3000 RPM's for 10 seconds. The blend immediately begins to froth with the agitation and is then poured into an 8×8×4 inch box and allowed to foam. Because of the froth, a cream time cannot be measured. The foam has a 4-minute gel time and a 5-minute tack free time. The foam is then allowed to cure for two days at room temperature. The foam is then cut to samples suitable for measuring physical properties and is found to have a density of 2.14 pcf. K-factors are measured and found to be as follows:
[0000]
Temperature
K, BTU In/Ft 2 h ° F.
40° F.
.1464
75° F.
.1640
110°
.1808
Example 5
[0116] Polystyrene Foam
[0117] This example illustrates the use of blowing agent in accordance with two preferred embodiments of the present invention, namely the use of HFO-1234ze and HFO-1234-yf, and the production of polystyrene foam. A testing apparatus and protocol has been established as an aid to determining whether a specific blowing agent and polymer are capable of producing a foam and the quality of the foam. Ground polymer (Dow Polystyrene 685D) and blowing agent consisting essentially of HFO-1234ze are combined in a vessel. A sketch of the vessel is illustrated below. The vessel volume is 200 cm 3 and it is made from two pipe flanges and a section of 2-inch diameter schedule 40 stainless steel pipe 4 inches long (see FIG. 1). The vessel is placed in an oven, with temperature set at from about 190° F. to about 285° F., preferably for polystyrene at 265° F., and remains there until temperature equilibrium is reached.
[0118] The pressure in the vessel is then released, quickly producing a foamed polymer. The blowing agent plasticizes the polymer as it dissolves into it. The resulting density of the two foams thus produced using this method are given in Table 1 and graphed in FIG. 1 as the density of the foams produced using trans-HFO-1234ze and HFO-1234yf. The data show that foam polystyrene is obtainable in accordance with the present invention. The die temperature for R1234ze with polystyrene is about 250° F.
[0000]
TABLE 1
Dow polystyrene 685D
Foam density (lb/ft 3 )
T ° F.
transHFO-1234ze
HFO-1234yf
275
55.15
260
22.14
14.27
250
7.28
24.17
240
16.93
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Disclosed are the use of fluorine substituted olefins, including tetra- and penta-fluoropropenes, in a variety of applications, including in methods of depositing catalyst on a solid support, methods of sterilizing articles, cleaning methods and compositions, methods of applying medicaments, fire extinguishing/suppression compositions and methods, flavor formulations, fragrance formulations and inflating agents.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/833,432 filed Jul. 26, 2006.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
[0002] (Not Applicable)
REFERENCE TO AN APPENDIX
[0003] (Not Applicable)
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates generally to a method of improving the behavior of a person or persons, and more particularly a card game used in a method of improving the behavior of a child or group of children.
[0006] 2. Description of the Related Art
[0007] It is well known that children need to be taught acceptable behavior in different circumstances, but that children often do not respond well to the lecture method of teaching. On the other hand, children enjoy games, especially those with clearly defined rules that they can understand. Therefore, there is a need for a behavior-teaching game that children enjoy.
BRIEF SUMMARY OF THE INVENTION
[0008] It is an object of an exemplary embodiment of the present invention to provide a method of encouraging desirable behavior in a learning person, such as a child or adult with behavioral problems. The method comprises the step of a first person giving at least one card to the learning person. The card bears at least one indicium of a reward and the card contains at least one indicium of the number of points required for receiving the reward. In a preferred embodiment, the indicium of the reward is text and/or graphics, and the indicium of the number of points required is text. The first person awards at least one point for desirable behavior by the learning person, such as cleaning up his or her room. The number of points is not critical, but the progress toward the reward is important. A plurality of points, awarded for desirable behavior, is summed, such as by the first person. The first person awards to the learning person the reward represented by said at least one indicium when the sum of the plurality of points is at least as great as said at least one indicium of the number of points required. Thus, when the learning person earns the prescribed number of points, he receives the reward indicated by the indicium on the card.
[0009] In a preferred embodiment, the first person, who is preferably a parent or guardian, indicates the awarded points on the card, such as by writing indicia in a predetermined region of the card, by stamping indicia in the predetermined region or by punching a hole in the predetermined region. Preferably, the learning person turns the card over to the first person when the reward is given. Most preferably, there are indicia on the card indicating positive awards for good behavior and negative awards for bad behavior.
[0010] Thus, using the method, a parent can encourage the desirable behavior and discourage the negative behavior. Additionally, the method provides flexibility for the parent to tailor the method to the particular desires and personality traits of the child.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] FIG. 1 is a front view illustrating a preferred card used in an embodiment of the present invention.
[0012] FIG. 2 is a rear view illustrating a preferred card used in an embodiment of the present invention.
[0013] In describing the preferred embodiment of the invention, which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. They are not limited to direct connection, but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The invention uses cards that can easily be held in the hands of the average child 3 years through 12 years old, as well as the average adult. An acceptable size is the size of conventional playing cards or baseball cards. The cards preferably have the appearance of trading or playing cards, inasmuch as they are similar in size, and preferably have a durable finish and construction. In a preferred embodiment, the cards have pictures, such as drawings, photographs, printed words or other graphical indicia indicating one or more rewards that can be obtained. The cards also have textual indicia printed thereon.
[0015] An example is shown in the card 10 of FIG. 1 . The card 10 has indicia including the text “playtime outside with daddy”, which indicates to the child that he will, upon attaining the required number of points, receive the sole attention of his father outdoors for a period of time. An alternative reward is “30 minutes on the computer”, in which the child would receive time on the computer for playing games, sending and receiving email, operating educational software, etc. Any positive outcome can be considered a reward. Thus, each card indicates a reward for the child's appropriate behavior. It is contemplated to have punishment cards that show a negative result for undesirable behavior. Such punishment cards are essentially identical to the reward cards shown and described herein, but have negative consequences for points awarded for negative behavior.
[0016] As noted above, the card 10 has the reward pictured or described on at least one side using images and/or other indicia, such as the text and graphics 12 shown in FIG. 1 . Additionally, each card is assigned a number of points that the child needs to attain in order to receive the reward, and the number of points can be indicated on the card, such as by the indicium 14 , or there can be a legend associated with the cards that associates each card with a particular number of points.
[0017] During the playing of the game, the parent or guardian initials or otherwise indicates on the card, such as in the region 16 in FIG. 1 , that one or more points have been earned for good behavior. This can be accomplished on the card by writing or otherwise indicating that one or more points have been earned. The award of points is indicated on the card immediately after the appropriate behavior in order to reward the child immediately for the desired behavior. When all of the points required for a particular reward have been earned, the child can redeem the card with the parent for the reward pictured and/or described.
[0018] In the method of the invention, one or more cards are awarded to one or more children to start the game, or as a result of the child or children engaging in desirable behavior. The parent or guardian determines which step works best for the particular child. For example, if the child picked up her toys without being asked, the father rewards the child with a card that has an illustration of the sun and a heading “Playtime outside with daddy!” In an alternative embodiment, the card or cards are given as an incentive to engage in desirable behavior in exchange for the reward on the card or cards.
[0019] In either case, the card or cards communicate that the reward indicated will be given upon the earning of “25 Points”. Of course, any number of points can be assigned to a reward, and the number is not a critical feature of the invention. The critical feature is the clear communication on the card or on a closely related source of information (placard, game box, legend, poster, etc.) of the number of points that are required in order to receive the reward.
[0020] Each time the child engages in behavior, which includes positive acts (e.g., cleaning up) and the omission of negative acts (e.g., not spilling food), that the parent wants to reward, one or more points can be given as an incentive. The number of points awarded is not a critical feature of the invention, as this will be determined by the parent or guardian. However the game can include guidelines for the award of points. The number of points should be in proportion to the desirability of the behavior. Therefore, for example, if a child picks up his toys after being instructed to do so by a parent, the number of points should be smaller than if the child did so without prompting.
[0021] In the preferred embodiment, the parent notes the award of points on the card itself, such as by writing on the card. Any means by which the number of points is indicated on the card is contemplated, including, but not limited to, writing, stamping, tearing off a portion of the card, and punching the card with a unique hole punch.
[0022] In one embodiment, the backs of the cards feature suggested good behavior to teach the children manners, respect, obedience, etc. For example, the back of the card 10 , shown in FIG. 2 , contains a list of good behavior awards and bad behavior awards. The method teaches children that they are rewarded for good behavior and punished for bad behavior. It also teaches them that some things, such as the promised rewards, are worth saving for by behaving well over a long period of time to earn points toward an eventual reward.
[0023] The first step in the method is the provision of one or more cards to a child. The cards have indicia indicating a reward and the number of points required to receive the reward. The second step is the awarding of points, noted by marking on the card, for desirable acts by the child. These acts result in one or more points toward the reward. Finally, upon receiving all of the points required, the child redeems the card for the reward indicated.
[0024] This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.
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A game that teaches learning children rewards for desirable behavior and punishments for undesirable behavior. One or more cards are given to a child or other learning person. The cards have indicia indicating a reward and the number of points required to receive the reward. Points are awarded, and preferably noted on the card, for desirable acts by the child. Finally, upon receiving all of the points required, the child redeems the card for the reward indicated. The invention teaches learners to behave appropriately to receive a reward, and avoid inappropriate behavior to avoid losing a reward.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/US2013/050031, filed Jul. 11, 2013, designating the United States and published in English on Jan. 15, 2015 as WO 2015/005921 A1, and which is incorporated in its entirety by reference herein.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a hydrogen reactor, and, more particularly to a multifactorial hydrogen reactor for use in the internal combustion engines for improving the fuel efficiency and performance thereof and production of the electricity.
[0004] 2. Description of the Related Art
[0005] Hydrogen is the most promising energy source first of all, because it is the most abundant element in the universe. Furthermore, as is known, the combustion of hydrogen produces water again.
[0006] The problem of decomposition of water molecules to produce hydrogen for use as a substitute for fossil fuels and for the following transformation to all existing forms of energy: mechanical, electrical, light, electromagnetic, which is the main source of existence of our civilization for more than a few decades, is a focus of the world of science.
[0007] In order to break the hydrogen bonds in water and aqueous solutions, researchers are using all kinds of physical and chemical processes. In our opinion, the most accessible and popular ways to produce hydrogen are electrolysis and oxidation of reactive metals.
[0008] For all its merits electrolysis has one major drawback—it is a relatively high energy-consuming process. As is known, the mass of one gram equivalent of hydrogen—1 g (½ mole) corresponds to the volume of 11.2 liters (STP). The weight of one gram equivalent of oxygen—8 grams (¼ mole) corresponds to the volume of 5.6 liters (STP). Consequently, the passage of 96485 C charge is allocated 11.2 liters+5.6 L=16.8 liters of Brown's gas, and thus to obtain it, the unit cost of electricity (charge) will be 96485 C: 16.8 liters=5743 C/l.
[0009] Many researchers have tried to solve the task of reducing energy costs:
EP0103656A3, Resonant Cavity for Hydrogen Generator, Inventors: Stenley Meyer; Publication date: Aug. 22, 1984. U.S. Pat. No. 5,089,107 Bi-polar autoelectric hydrogen generator; Inventors: Francisco Pacheco; Publication date: Feb. 18, 1992. WO2012054842 A2, Enhanced water electrolysis apparatus and methods for hydrogen generation and other applications; Inventors: Michael Lockhart; Publication date: Apr. 26, 2012.
[0013] In an effort to increase efficiency in the production of hydrogen, electrolysis cells have been used a variety of approaches, where the relative success was achieved either through design changes, or due to a combination of electrolysis with other methods of exposure to hydrogen bonds.
[0014] However, until now, results obtained in the aforementioned patents are not widespread, because they are energy-intensive and failed to become a model for the industrial mass production of hydrogen:
U.S. Pat. No. 8,075,748 B2, Electrolytic cell and method of use thereof; Inventors: Roy E. McAlister; Publication date: Dec. 13, 2011, proposed an electrolytic cell, comprising a tight vessel, electrodes, electric current source in electrical contact with the electrodes, electrolyte, and gas. Wherein this gas is formed during the electrolysis at or near the first electrode, the cell is provided with a separator, which has an inclined surface, and includes an electrode to be able to direct the flow of the electrolyte and the gas by the difference between the density of the electrolyte and the total density of the electrolyte and the gas, so that the gas is moved toward the second electrode. U.S. Pat. No. 7,922,878 B2, Electrohydrogenic reactor for hydrogen gas production; Inventors: Bruce Logan; Publication date: Apr. 12, 2011. US 2006/0011491 A1, Bio-electrochemically assisted microbial reactor that generates hydrogen gas and methods of generating hydrogen gas. Inventors: Stephen Grot, Bruce Logan; Publication date: Jan. 19, 2006.
[0018] The process of oxidation of reactive metals, particularly relatively cheap aluminum devoted subject of hundreds of studies. Among them, the most interesting patents and scientific papers:
EP 1301433 A1, Hydrogen production from aluminum water and sodium hydroxide. Inventor: Andersen Erling Reidar; Apr. 16, 2003; Hydrogen Generation by Accelerating Aluminum Corrosion in Water with Alumina, World Academy of Science, Engineering and Technology 55, 2011, Inventors: J. Skrovan, A. Alfantazi, and T. Troczynski. Activation of aluminum metal to evolve hydrogen from water, Int. J. Hydrogen Energy, 33 (2008) 3073-3076, Inventors: A. V. Parmuzina and O. V. Kravchenko.
[0022] None of the methods proposed in the aforementioned patents and scientific papers, including all known chemical dissolution reaction of the oxide film, make a continuous oxidation reaction of hydrogen. Production of hydrogen by aluminum would help revolutionize the energy sector, if the oxidation process was not so brief and not stopped at the appearance of the oxide film on the surface of reagent. For the oxide film to be removed continuously, until the total oxidation of aluminum participating in the reaction, in practice, the oxide film is removed by amalgamation or hot solutions of alkali. However, the chemical process can be interrupted or can use other reagents in the oxidation of aluminum, which are often highly toxic such as mercury chloride.
[0023] We conducted a patent search to a depth of 50 years and unfortunately found no methods or devices that would make the process of hydrogen production cost and scale that can be the foundation of future hydrogen energy. However, this search has allowed us to define the priorities in choosing the physical and chemical processes that, while the impact on the water molecules will be able to break the hydrogen bonds splitting “H 2 O” on the “H 2 ” and “O”, necessary to humanity.
[0024] Here is a list of physical processes that we are interested in, and links to scientific papers and patents that study these processes:
[0025] Electrolysis
[0026] Electrolysis of water is the most well-known and well-researched method of hydrogen production. It provides the pure product (99.6-99.9% H 2 ) in one process step. However, the cost of electricity for production of hydrogen is approximately 85.5%; thus making existing methods for producing hydrogen via electrolysis uneconomical.
U.S. Pat. No. 8,308,918 B2, Hydrogen generator; Inventors: Jae Hyoung Gil Jae Hyuk Jang Chang Ryul JUNG. US 20080245673 A1; Hydrogen generation system; Inventors: Asoke Chandra Das Chaklader, Debabrata Ghosh, Zhaolin Tang, Zhong Xia. U.S. Pat. No. 8,282,812 B2; Apparatus for producing hydrogen from salt water by electrolysis; Inventor: John Christopher Burtch. U.S. Pat. No. 7,922,781 B2, Hydrogen generation apparatus and method for using same; Inventors: Anand S. Chellappa, Michael Roy Powell, Charles J. Call. U.S. Pat. No. 8,075,958 B2; Methods for providing thin hydrogen separation membranes and associated uses; Inventors: Anand Chellappa, Thomas R. Vencill, W. Doyle Miller. US 20130105307 A1; Hydrogen and oxygen generator; Inventors: Dejan Pavlovic and Nenad Pavlovic, Oct. 31, 2012.
[0033] None of the above works were able to make production of hydrogen be cost-effective i.e. recommended for industrial production.
[0034] Production of Hydrogen with Aluminum
[0035] Production of hydrogen from water can be considered a method of “crowding out” of hydrogen from water by active metals and alloys. Among the most promising of these metals is aluminum which is capable of radically solving this problem.
U.S. Pat. No. 6,440,385; Hydrogen generation from water split reaction; Aug. 27, 2002; Inventors: Asok C. D. Chaklader; Assignee: The University of British Columbia, discloses an attempt to generate hydrogen from water on demand by water decomposition reaction which has been partly successful in some newer developments. Aluminum was used to generate hydrogen from water, but is not very efficient, as this method requires large concentration of other materials in the aluminum to accomplish the water split reaction. U.S. Pat. No. 4,308,248; Material and method to dissociate water; Dec. 29, 1981; Inventor: Eugene R. Anderson; Assignee: Horizon Manufacturing Corporation. U.S. Pat. No. 7,144,567; Renewable energy carrier system and method; Dec. 5, 2006; Inventor: Erling Jim Andersen.
[0039] Aluminum is a very promising raw material for the production of hydrogen: it is cheap, very common on the planet and is very active oxidized in water. However, as discussed above, the oxidation process is stopped once the appearance of the oxide film on the aluminum surface, which makes it possible to use aluminum for food dishes but makes aluminum unsuitable for continuous hydrogen production. None of the foregoing patents disclose that anyone in the world succeeded with minimal cost (less than 1 kW/h) in making the oxidation of aluminum continuous.
[0040] Cavitation
[0041] Cavitation is the formation of cavities in the liquid (cavitation bubbles) filled with gas, vapor or a mixture thereof. Cavitation is the result of local reduction of pressure in the fluid, which can occur either by increasing its velocity (hydrodynamic cavitation), or in the passage of acoustic waves of high intensity during the half-life (acoustic cavitation).
U.S. Pat. No. 6,719,817 B1; Cavitation hydrogen generator; Apr. 13, 2004, Inventor: Daniel J Marin. US 20120058405 A1; Cavitation assisted sonochemical hydrogen production system; Mar. 8, 2012, Inventors: Jenifer Jeong, et al. Laborde J L (1998), Acoustic cavitation field prediction at low and high frequency ultrasounds.
[0045] The patents cited above strongly support effectiveness of the impact of acoustic cavitation process for hydrogen production. However, it requires energy to power the generator producing electrical impulses applied to the acoustic transducers (piezoelectric or magnetostrictive).
[0046] Sound Vibrations: Sound, Infrasound, Ultrasound, Hypersound
[0047] A person's hearing can perceive frequencies 16-18,000 Hz, which are called sound. But the world around us is filled with the sounds that lie above and below this range—infrastructure and ultrasounds. The lower boundary of the ultrasonic range is called the elastic vibrations of a frequency of 18 kHz. The upper limit is determined by the nature of elastic ultrasonic waves which can propagate only on the condition that the wavelength is much greater than the mean free path of the molecules (in gases) and interatomic distances (in liquids and gases). In gases, the upper limit is 106 kHz, and in liquids and solids, the upper limit is 1010 kHz. Typically, ultrasound is at a frequency of 106 kHz and higher frequencies are called hypersound. In many universities in the world, sound, in all its ranges of frequency, is a main tool in the study of liquid systems, including the process of rupture of hydrogen bonds.
U.S. Pat. No. 5,404,754: An ultrasonic detection of high temperature hydrogen attack; Inventor: Weicheng D. Wang.
[0049] Ionization
[0050] The ionization of water located in the cells that produce hydrogen is due to the pulsed discharge of electric current, supplied to the electrodes.
U.S. Pat. No. 5,149,407A; Process and apparatus for the production of fuel gas and the enhanced release of thermal energy from such gas; Inventor: Stanley A. Meyer; Publication date Sep. 22, 1992. U.S. Pat. No. 5,616,221A; Electrolytic ionized water producing apparatus: Inventors: Hidemitsu Aoki, et al.
[0053] The Thermal Energy
[0054] The decomposition of water molecules in the hydrogen generator is most often due to an increase in rotational kinetic energy of the molecules and the energy of their oscillations. Thermal energy is just the kinetic energy of a molecular scale. Charging energy to increase the kinetic energy of the molecules is a micro hydraulic shocks sent into the liquid medium of the hydrogen reactor.
EP 2433902 A1; Method and device for producing combustible gas, heat energy, hydrogen and oxygen; Inventors: Partnou Yauheni Viktorovich; Publication date Mar. 28, 2012.
[0056] Plasma
[0057] The concept has emerged in the process of our research involves extensive ionization of hydrogen gas in the reactor, and in combination with high pressure and temperature identification with the plasma. Therefore, the works associated with the use of plasma for the decomposition of water molecules were at the center of our attention.
US 20090035619 A1; Methods and systems of producing molecular hydrogen using a plasma system in combination with an electrical swing adsorption separation system; Inventors: Charles Terrel Adams; Publication date Feb. 5, 2009, which is certainly of scientific interest, though created in the “low-temperature plasma” raises questions. Furthermore, unlike the hydrogen reactor, great advantage of which is the fact that its production is a completely environmentally friendly product, in this patent, the plasma system produces molecular hydrogen in the gas stream along with hydrogen and carbon monoxide. U.S. Pat. No. 6,806,651 B1; High-density plasma source; Inventor: Roman Chistyakov; Pub: Oct. 19, 2004.
[0060] Membrane Technology
[0061] Assuming though that the gas mixture obtained at the decomposition of water may have a different purpose, we have provided methods for advanced separation and purification of gases, including gas mixture separation technology based on the action of a special kind of barriers (membranes) with selective permeability of the gas mixture components. In the broadest sense, the membrane should be understood as a non-equilibrium system open at the boundaries of different compositions which are supported shared mixtures under the influence of various factors (temperature, pressure, gravity or the magnetic field, centrifugal force). Separating capacity of the system depends on the properties of the membrane and separated mixture component properties as well as their interaction.
US 20060147763A1; Upflow microbial fuel cell (UMFC); Inventors: Largus Angenent, Zhen He; Publication date is Jul. 6, 2006. U.S. Pat. No. 7,922,781 B2; Hydrogen generation apparatus and method for using same; Inventors: Anand S. Chellappa, Michael Roy Powell, Charles J. Call; Publication date: Apr. 12, 2011.
[0064] Catalyst
[0065] Most processes in the chemical industry today run using heterogeneous catalysts. Catalyst is a substance that accelerates the rate of a chemical reaction without entering it. In fact, among these substances may occur many chemical reactions. As a rule, a catalyst system “tuned” only for one of them. That is, each particular catalyst can accelerate only a single process.
EP 2571805 A1; A process for the production of hydrogen, the sequestration of carbon dioxide and the production of building materials starting from slags and/or industrial ashes; Inventors: Paolo Plescia, Enrico Barbarese, Maurizio Pinna; Publication date: Mar. 27, 2013.
[0067] Turbulence
[0068] Cause of turbulence in a hydrogen generator may be virtually any external influence directed to the liquid in the cell box.
[0069] Each of the frontal water waves propagating inside the hydrogen reactor during the motion loses energy, including passing through holes in electrodes turning in a relatively slow flow of water with a twist, which can be considered the turbulence, which helps to remove the gas bubbles from the surface of the electrodes.
RU2357109C1; Apparatus and method for influencing the vortex structures in turbulent air stream; Inventor: Ostrikov Nicholas; 07.11.2007.
SUMMARY
[0071] It is an object of the present invention to provide an improved apparatus for decomposition of water into hydrogen and oxygen for use in internal combustion engines and production of the electricity.
[0072] It is another object of this invention to create a device that would provide humanity with a sufficient amount of low-cost and environmentally friendly fuel.
[0073] The present invention provides a multifactorial hydrogen reactor with elevated hydrogen production (e.g., over the proposed electrolytic cell of U.S. Pat. No. 8,075,748), due to complex set of the following sixteen (16) physical and chemical processes, acting simultaneously on the hydrogen bonds in aqueous solutions of electrolytes and accelerating the hydrogen production process:
Electrolysis. Only the hydrogen reactor described herein is able to solve the problem of the cost of hydrogen generation using electrolysis, by the combination of new methods and technology solutions. Production of hydrogen with aluminum. Aluminum has become the primary active metal in our hydrogen reactor. In a hydrogen reactor, the oxide film on aluminum is continuously removed under the action of a series of electro-hydraulic shocks. An advantage of our hydrogen reactor compared with U.S. Pat. No. 6,440,385 is that in our reactor, there are no other reactants and reaction products, but only hydrogen and oxygen. For the first time in the world, continuous hydrogen production was achieved in our hydrogen reactor. Cavitation. Cavitation process in this hydrogen reactor occurs when the frontline or frontal water wave of the electro-hydraulic shock waves passes through the holes in the electrolyzer's electrodes. An advantage of our hydrogen reactor is that cavitation therein is a byproduct of the electro-hydraulic shock aimed at removing the oxide film and the effect of the shock wave, which passes through the holes of the electrodes creates a powerful cavitation effect. Sound vibrations as sound perceived by humans. In the hydrogen reactor, sound in a wide frequency range occurs when a shock wave passes through the holes in the electrodes forming gas bubbles. In this hydrogen reactor, acoustic vibrations of different frequencies: infrasound, sound, ultrasound, hypersound, caused by the passage of the frontline water wave through the holes in the electrolyzer's electrodes. Ionization. The ionization of water located in the cells that produce hydrogen is due to the pulsed discharge of electric current, supplied to the electrodes. The thermal energy. The decomposition of water molecules in the hydrogen generator is most often due to an increase in rotational kinetic energy of the molecules and the energy of their oscillations. Thermal energy—it's just the kinetic energy of a molecular scale. Charging energy to increase the kinetic energy of the molecules is a electro-hydraulic shocks sent into the liquid medium of the hydrogen reactor. Plasma. In our hydrogen reactor, the impact of electro-hydraulic shock in distributed microscopic fluid generates powerful light emission, the pressure in the tens of thousands of atmospheres and temperatures of several thousand degrees, all of this is certainly a cause and a consequence of plasma formation under the influence of electro-hydraulic shock. Membrane Technology. Assuming though that the gas mixture obtained at the decomposition of water may have a different purpose, we have provided methods and advanced separation and purification of gases including mixtures of gas separation technology based on the action of a special kind of barriers (membranes) with the selective property permeability gas mixture components. In the broadest sense, the membrane should be understood a non-equilibrium system open at the boundaries of different compositions which are supported shared mixture under the influence of various factors (temperature, pressure, gravity or the magnetic field, centrifugal force). Separating capacity of the system depends on the properties of the membrane and separated mixture component properties as well as their interaction. Catalysis. Most processes in the chemical industry today run using heterogeneous catalysts. Catalyst—a substance that accelerates the rate of a chemical reaction without entering it. In fact, among these substances may occur many chemical reactions. As a rule, a catalyst system “tuned” only for one of them. That is, each particular catalyst can accelerate only a single process. During the development of our hydrogen reactor, a variety of catalysts have been used, including coverage of the platinum group metals, and various composite materials, but titanium was preferred. Turbulence. Each of the microwave fronts propagating inside the hydrogen reactor during the motion loses energy, including passing through cavitators turning in a relatively slow flow of water with a twist, which can be considered the turbulence, which helps to remove the gas bubbles from the surface of the electrodes. The electrostatic field. The electrostatic field inside our hydrogen reactor is created by potential difference voltage (10-12 volts) supplied to the vessel, where the minus applied to body container and the plus to the lid of the body, which is insulated from the container. The negatively charged hydrogen ions will move toward the positively charged cover, where there is an outlet for hydrogen. Electromagnetic field. In the hydrogen reactor, under the influence of electro-hydraulic shock occurs the excitation of the weak quasi-static and low-frequency electromagnetic fields. Their nature is so far poorly understood, but neglecting their influence on the decomposition of water molecules would be unwise. The light energy. Well-known fact in science is that the light energy is an effective tool for the decomposition of water molecules. Accordingly, in our hydrogen reactor, the light energy of the plasma arising due to electro-hydraulic shock makes a significant contribution to the production of hydrogen.
[0087] This hydrogen reactor, in which energy costs for electrolysis compensated by a parallel reaction can solve the problem of an unlimited hydrogen production at a price of 90 cents per 1 kg, which is 3-4 times lower than existing today in the world prices for hydrogen. When used for industrial production of hydrogen, our hydrogen reactor can guarantee global transition to “green” energy technologies.
[0088] In order to reduce energy costs in our reactor we merged two chemical reactions—exothermic and endothermic—the products of which are hydrogen.
[0089] These reactions are:
[0000] Al+2H 2 O- Al—OOH+3/2H 2 +Q 1 .
[0000] 2H 2 O- 2H 2 +2O−Q 2 .
[0000] In these reactions, Q 1 and Q 2 have the same magnitude and substantially cancel each other.
[0090] The heat required for the electrolysis reaction: 2H 2 O->>2H 2 +2O−Q 2 is obtained by the reaction of the oxidation of aluminum: Al+2H 2 O->>Al—OOH+3/2H 2 +Q 1 .
[0091] The heat required for the electrolysis reaction, which is coming from the oxidation of aluminum is continuously supplied as aluminum oxide film continues to be destroyed by the electro-hydraulic shock.
[0092] The oxidation of aluminum in the water would already ensure the production of hydrogen in virtually unlimited quantities, but the oxide film formed on the surface making this route unprofitable.
[0093] We have fully solved this problem. The method we used is the electro-hydraulic shock effect which occurs in liquids such as water, with electric discharge therein, and is an electric explosion in the liquid with substantially instantaneous release of energy at a given point. Number and rate of allocated kinetic and thermal energy in the electric discharge area depend on many factors, including the parameters of the electrical discharge and fluid properties. Electro-hydraulic effect generates shock waves in the liquid at breakdown. Electro-hydraulic shock is a complex set of phenomena. In its first step, lasting microseconds, a plasma channel is formed at a temperature of 40,000° C. The plasma expands at a speed commensurate with the speed of sound in water (1410 m/sec).
[0094] This forms the first shock wave and the cavity is filled with hot steam and gas, which gradually completes its expansion, then begins to throb and eventually collapses. As a result, decomposition and ionization of molecules occurs in the resulting plasma along with concomitant light radiation, shock waves, intense sound waves in a wide frequency range, as well as cavitation and pulsed electromagnetic fields.
[0095] In our reactor electro-hydraulic shock is used to remove oxidation film from the aluminum making oxidation of aluminum and production of the hydrogen uninterrupted until all aluminum is oxidized by transforming this momentum into a sequence of low-power pulses distributed to 42 electrodes.
[0096] Due to this effect in the hydrogen reactor electro-hydraulic shock on the water molecules is carried out not by the entire volume of the device but in each individual “point.” This means that the device creates the so-called local centers of the decomposition of water molecules.
[0097] In our hydrogen generator, the local energy centers affect micro-volumes that allow the temperature to rise, or more precisely, to increase the kinetic energy of the molecules exclusively in the particular microscopic volumes, in which an avalanche process of decomposition occurs due to the ultra-high pressure and temperature.
[0098] In general, the phase transition of water is characterized by the formation of local centers of a new phase in the initial phase. For example, the transition of liquid water to ice is proceeded by the formation of ice nucleation as local centers of crystallization.
[0099] For the first time in one device—our hydrogen reactor, we were able to combine sixteen different physical-chemical means to affect hydrogen bonding of water molecules. FIG. 11 presents the physical and chemical processes that affect hydrogen bonding of water molecules in a hydrogen reactor created by us.
[0100] Thus in the hydrogen reactor we were able to replace energy “swapping” of all the above mention processes with the single pulses, with help of the set of “converters” placed in the reactor to convert mechanical, sound, light, electricity and electromagnetic energy.
[0101] A special role is played here by the electrostatic field that will cause the dipoles of water molecules to rotate in the direction of the electrodes by its poles.
[0102] Calculations show that for the production of 1 kg of hydrogen requires oxidizing of 9 kg aluminum. Therefore to simplify the calculations of performance reactors, cartridges of hydrogen reactor designed to produce different amounts of hydrogen must have a weight of multiples of 9 kg (9, 18, 27, 36, 45, etc.) kg.
[0103] In our hydrogen reactor, electro-hydraulic shock is implemented through electrodes. In order to avoid “run-off” charge, the ends of the electrodes have the shape of a hemisphere.
[0104] A petrol engine with 180 hp (134) kW fueled part of the oxygen-hydrogen mixture produced in the hydrogen reactor has a volume of 8 liters per minute in the overall performance of the prototype 30-32 liters per minute.
[0105] Pure hydrogen at (22-25) liters per minute passed through membrane filters and was stored with a further compression for the intended use. The rotary movement of the cardan shaft of the engine transmitted an electric power capacity of 120 kW to the rotor.
[0106] Electricity produced can be redistributed between the consumer and the power system of the hydrogen reactor at a ratio of 11:1 i.e. 110 kW received the consumer, and spent 10 kW to power the pulse generator designed for the implementation of the electro-hydraulic shock and charging the battery supply of electrolyzer chain.
[0107] Testing of the hydrogen reactor was carried out over several series of 10 hours. The products of each series were 1,200 kW/h of electricity and 18,000 liters of pure (99.9%) of hydrogen under normal conditions. The average value of the costs of the entire series of tests was 2 gallons of gasoline, or about $8, the cost of 20 pounds of aluminum is $0.78×20=$15.6. Thus the production of 1,200 kW/h of electricity and 18,000 liters of pure (99.9%) of hydrogen under normal conditions cost $23.6. Since one liter of hydrogen weighs 0.0899 grams, the total weight of hydrogen produced was 1618.2 grams. Consequently, even a prototype hydrogen reactor can produce hydrogen at $0.9 per kilogram and electricity at $0.0183 i.e. by 1.9 percent.
[0108] Serial produced hydrogen reactors still will be able to reduce the above-mentioned prices by a factor of 10.
[0109] The oxidation of aluminum, produced in the hydrogen reactor, i.e., production of hydrogen, may be 10-20% greater when bauxite or alum earth are used as reagents.
[0110] The big advantage of the hydrogen generator is the fact that produced hydrogen can help store energy generated by power plants at night and on weekends, as well as renewable energy sources (solar, wind).
BRIEF DESCRIPTION OF THE DRAWINGS
[0111] The forgoing aspects and many of the attendant advantages of this invention will become more appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0112] FIG. 1 is a schematic top view of the housing body/corpus of the multifunctional hydrogen reactor in accordance with the present invention;
[0113] FIG. 2 shows a schematic view of the first electrolyzer's electrode;
[0114] FIG. 3 shows a schematic view of the second electrolyzer's electrode;
[0115] FIG. 4 shows a schematic view of the one of the proposed shapes of gaskets, which space apart the two electrodes of the FIG. 2 and FIG. 3 ;
[0116] FIG. 5 is a schematic view of the cartridge 5 ;
[0117] FIG. 6 is a schematic side view of electro-hydraulic electrodes holder 6 ;
[0118] FIG. 7 is a schematic side view of the lid/cover of electro-hydraulic electrodes holder 6 ;
[0119] FIG. 8 is a schematic side view of the lid of the multifactorial hydrogen reactor in accordance with the present invention;
[0120] FIG. 9 is a schematic view of the system of the multifactorial hydrogen reactor in accordance with the present invention.
[0121] FIG. 10 is a schematic view of the negative and positive charges of power connected to the electrolyzer's electrodes through housing/corpus of the reactor.
[0122] FIG. 11 presents the physical and chemical processes that affect hydrogen bonding of water molecules.
DETAILED DESCRIPTION
[0123] It should be understood that these embodiments are only examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others. In general, unless otherwise indicated, singular elements may be in the plural and vice versa with no loss of generality.
[0124] Expecting that the gas mixture obtained in dissociation of water may have different purposes, we provide modern methods of separation and purification of gases, including mixtures of gas separation technology, based on the action of a special kind of barriers (membranes) possessing selective permeability properties of the gas mixture components.
[0125] As described herein, the hydrogen reactor combines two processes each of which produces hydrogen: (i) electrolysis producing a hydrogen-oxygen mixture (Brown's Gas) and (ii) oxidation reaction. Therefore, there are two types of consumers—diesel or petrol engine, for which gas mixture and storage are preferable, which for technological and safety reasons requires pure hydrogen.
[0126] The Use of Hydrogen Reactor
[0127] The hydrogen reactor of this invention can be used in two main areas:
[0000] 1. For hydrogen production, followed by compression, storage and transport to the place of consumption in vehicles or pipelines.
2. For the production of electricity with a further transformation in all possible forms of energy (mechanical, electromagnetic, sound, light and chemical).
[0128] In this case, the source of energy is close to the consumer, allowing the user to save enormous material resources by eliminating the need for costly transmission lines, as well as raising and lowering transformer substations.
[0129] Hydrogen produced by the hydrogen reactor can be used as basic fuel for the newly constructed facilities, and optionally for the existing ones using fossil fuels (oil, natural gas, coal) for processes requiring heat.
[0130] In this case, the hydrogen can provide (80-90) % saving of primary fuel and can dramatically alter the ecological situation in the region by reducing harmful emissions into the atmosphere.
[0131] One of the important advantages of hydrogen energetics is that it provides savings using the existing energy infrastructure facilities.
[0132] Thus hydrogen, either in pure form or mixed with other fuels, can be effectively used in nuclear power plants, solar plants, nuclear aircraft carriers, nuclear-powered ships (civilian or military), nuclear submarines, coal-fired power plants, power plants using natural gas, on diesel power generation plants, biofuels, waste incineration plants, in all the modes of transport: water, rail, road, including freight etc.
[0133] The market volume of world hydrogen production is estimated at 53-55 million tons in 2013. Asia and the Pacific region is the largest producer of about 40% of world production of hydrogen. The region produces about 20-21,000,000 tons of hydrogen per year. In addition, Asia and Pacific region are the largest market customers of hydrogen. Europe and Eurasia is the second largest producer, followed by North America, which comes third.
[0134] Major benefits of the hydrogen reactor of this invention:
[0000] 1. The main obvious advantage of a hydrogen reactor is hybrid conversion in internal combustion engines to save on gas.
2. Unlike fossil fuels, hydrogen is produced in a hydrogen reactor from water.
3. It lowers the consumption and saves on combustion of fuel.
4. Hydrogen produced by a hydrogen reactor doesn't require any storage.
5. It does not require any contained pressure in heavy cylinders like compressed natural gas (CNG).
6. If a hydrogen reactor is used on trucks and small vehicles, there will be a huge increase in fuel savings and fewer trips to gas station.
7. Burning garbage or unburned leftovers of garbage has always been a problem for industrial or municipal incinerators. The specific heat of hydrogen can lower the moisture content from 50% to 30% of unburned garbage because hydrogen burns faster and hotter which helps to boost combustion of garbage completely.
8. If a hydrogen reactor is coupled with solar, it will increase the efficiency of production of hydrogen.
9. A hydrogen reactor is 100% carbon free technology.
10. A hydrogen reactor solves and lowers hazardous air pollutants and gas emissions of particulates related to coal and diesel.
11. A hydrogen reactor can work with all types of fuel including gasoline, propane, natural gas, coal, clean coal, diesel, biofuel, bio diesel, biomass, ethanol, solar, etc.
12. The following fields and sectors could extremely benefit from using a hydrogen reactor: energy sector, automotive industry, home appliances, waste treatment, environment, health, safety, community development etc.
13. The produced hydrogen from a hydrogen reactor will boost internal combustion engine's performance while preventing smog and damage on the engine.
14. People can benefit from the tax refunds owed to them by law for using green technology.
15. Multi-process hydrogen reactor development will bring new discoveries, new products and services to the market.
[0135] FIG. 1 shows a general view of a working prototype of a multifactorial hydrogen reactor. The reactor housing/corpus 1 is a closed vessel. It is shaped like a parallelepiped with sides of 24″×12″×9″. If necessary, frame size can be increased proportionally. The reactor housing is made of titanium sheet 3-5 mm thick, and can also be made of nickel, titanium and platinum group metals (PGMs). Its inner walls serve as catalysts in the chemical reactions occurring in the reactor. Dielectric isolation gasket 2 made of teflon thickness min. ¼″; it covers the entire bottom of the device; it can sustain high temperature and is not involved in the process of reaction of the device.
[0136] With reference to FIG. 1 and FIG. 8 , the major parts of the hydrogen reactor are power supply, electrolyzer's system including electrodes 3 & 4 , which can have the form of rectangular serpentine springs, perforated aluminum plates 7 and water, cartridges 5 holding perforated aluminum plates, and electro-hydraulic electrodes holder 6 . The electro-hydraulic electrodes holder 6 has vertical openings/ports and a parallelepiped shaped technological rectangular cavity hollowed out along the diagonal of the body or at an angle of 45 degrees to the bottom surface of the housing. The hydrogen reactor also has high voltage multipin connectors 13 , dielectric isolation gasket 2 covering entire floor of the reactor, means for electrically connecting the positive and negative electrodes to the power source, corpus lid 27 , closure 28 , the thermometer and pressure sensor—tridicator boiler gauges 22 located on the surface of the lid 27 , high pressure release valve 23 for adjusting the pressure inside of hydrogen reactor, exhaust pipe or tube 24 through which hydrogen is supplied to the consumer, and an electro-impulse dispenser 26 which transmits impulses to the electrolyzer's electrodes synchronously through high voltage multipin connectors.
[0137] Electrolyzer's electrodes 3 & 4 and perforated aluminum plates 7 accelerate the oxidation of aluminum, where the electrodes 3 & 4 convert the electro-hydraulic shock waves into the sound vibrations over a wide frequency range.
[0138] Electrolyzer's electrodes 3 and 4 , FIG. 2 and FIG. 3 accordingly, at the same time are titanium catalysts and cavitators in the cavitation reaction. The electrolyzer comprises electrodes 3 and 4 put together with gaskets 30 , FIG. 4 submerged in the water. Electrodes 3 and 4 made of perforated titanium sheet, and can also be made of nickel, titanium and platinum group metals (PGMs). Power is supplied to the electrodes 3 and 4 by power wires, where one of the electrodes is the anode and the other one of the electrodes is the cathode. The intensity of the process, according to the laws of Faraday, is directly proportional to the amount of electrical charge passing through the electrolyte as electrical current in the circuit. The chosen configuration of electrodes 3 & 4 , which consists of seven sections and the series connections of these sections in accordance with Ohm's law, allows all the electrodes to have the maximum current from the power source. The configuration or the geometric shape of the anodes and cathodes are in the shape of a rectangular serpentine spring.
[0139] Hydrodynamic cavitation occurs during the passage of the shock wave through the holes of electrolyzer's electrodes 3 & 4 , providing additional energy, said energy contributes to the breaking of hydrogen bonds, wherein said electrodes 3 & 4 are also cavitators in cavitation process.
[0140] The cavitation effect was achieved through the holes in the electrodes, with these holes covering the entire surface of the electrodes 3 & 4 . The holes are made in three different diameters: 4, 6 and 8 mm alternately, covering the entire surface of the electrodes 3 & 4 (see 29 , FIG. 2 ). Prerequisite for intensive decomposition of water molecules is also the clearances between the electrodes 3 & 4 . But the process of cavitation occurs due to the main cartridge 5 , FIG. 5 . Seven cartridges 5 inserted into the cells/openings formed by the shape of electrodes 3 & 4 .
[0141] FIG. 10 shows a schematic view of the negative and positive charges of power connected to the electrolyzer's electrodes through housing/corpus of the reactor. Positive voltage is applied on the rod 133 , therefore, it must be insulated from the housing/corpus of the reactor; it only contacts the electrode 4 —anode. The rod 133 also passes through the corpus/housing of the reactor without touching it using the dielectric sleeve 134 , which is located within the housing. Two nuts 135 fix sleeve 134 from different angles or directions. The diameter of nut 135 is greater than the diameter of sleeve 134 . Nuts 135 are made from dielectric material. Metal nuts 136 attach wire to the anode (positive). 131 and 132 are the bolts with the nuts. A bolt 132 passes through an opening in the housing; where the bolt head is located inside the reactor; where the bolt head size is 2.5 cm and the entire length of the bolt with its head is 3.6 cm or 7.6 cm. Bolt 132 does not touch electrode 4 —anode. An electric current is provided to a bolt 132 on the outside of the reactor housing via negative wire. Bolt 132 supplies a negative charge of electricity to the body of the reactor; a negative charge of electricity is supplied to the bolt 131 from the body, which passes through the opening in the housing of the reactor; bolt 131 is in contact with the housing of the reactor and is in direct contact with the electrolyzer's electrode 3 —cathode. Thus, electrode 3 has a negative charge of electricity and is the cathode.
[0142] The advantage of our hydrogen reactor is that cavitation therein is a byproduct of the electro-hydraulic shock waves aimed at removing the aluminum oxide film and which pass through the holes of the electrodes 3 & 4 creating a powerful cavitation effect. In this hydrogen reactor, acoustic vibrations of different frequencies (infrasound, sound, ultrasound, hypersound) are caused by the passage of the frontline water wave through the holes in the electrolyzer's electrodes 3 & 4 , said holes covering the entire surface of the electrodes and having three different diameters: 4, 6 and 8 mm respectively.
[0143] Sound in a wide frequency range occurs when the electro-hydraulic shock waves pass through the holes of the electrodes forming gas bubbles. This is achieved due to the process, which takes place in forty two (42−x) distributed volumes of the hydrogen reactor under the effect of the electro-hydraulic shocks, forming local micro-cavities with pressures in the hundreds of thousands of atmospheres and a temperature of several thousand degrees (plasma).
[0144] The formation of all processes in the hydrogen reactor due to the electro-hydraulic shocks include the fact that frontline water wave pressure occurs in forty two (42) distributed micro-volumes of the electro-hydraulic electrodes holder 6 .
[0145] Forty-two distributed micro-volumes are achieved by multiplying seven electro-hydraulic electrodes holders 6 by six electrodes 42 - 47 inserted into the vertical openings or ports 10 A, FIG. 6 in each of said frames.
[0146] Frontline water wave pressure passing through holes in the electrodes—cavitators 3 and 4 creates a microenvironment of subsonic, sonic and ultrasonic vibrations, heat, ultrasound, hydrodynamic cavitation, turbulence, high-pressure, chemical catalysts, light energy, electrostatic and electromagnetic fields, i.e. instantaneous release of energy in the empty cavity of electro-hydraulic electrodes holder 6 . This process creates these effects using an electronic impulse distributor 26 , FIG. 8 , where the electrodes create an electro-hydraulic shock. It causes a complex set of phenomena, which lasts for a microsecond, to form plasma, light emission, shock waves, sound waves, as well as cavitation and pulsed electromagnetic fields.
[0147] Infrasonic, sonic, and ultrasonic vibrations that, along with the heat, ultrasound and hydrodynamic cavitation, turbulence, high-pressure, chemical catalysts, light energy, electrostatic and electromagnetic fields, dramatically increases the process decomposition of water molecules.
[0148] One of the major works performed by the electro-hydraulic shocks is that the oxide film covering the aluminum plates 7 , FIG. 5 , is broken by electro-hydraulic shock. Formation of an oxide film on the aluminum surface is a natural process. Thus, the electro-hydraulic shocks disrupt the oxide film allowing continuing uninterrupted oxidation reaction of reactive metals, in this case aluminum. The oxidation of aluminum does not stop or interrupt due to the disruption of the oxide film by electro-hydraulic shocks and therefore, the process continues until the complete oxidation of the full volume of the aluminum of the cartridge and thus until the complete release of hydrogen.
[0149] Our hydrogen reactor combines two chemical reactions: exothermic and endothermic, the products of which are hydrogen.
[0150] All the processes occurring in this reactor: the allocation of light energy, heat, high pressure, ionization of the liquid, the acoustic effect, and cavitation, etc. occurring simultaneously results in intensive breaking of hydrogen bonds.
[0151] Parallel exothermic and endothermic reactions occurred in the process of electrolysis. The heat required for the electrolysis reaction: 2H 2 O->>2H 2 +2O−Q 2 is obtained by the reaction of the oxidation of aluminum: Al+2H 2 O->>Al—OOH+3/2H 2 +Q 1 . The heat required for the electrolysis reaction, which is coming from the oxidation of aluminum is continuously supplied as aluminum oxide film continues to be destroyed by the electro-hydraulic shock.
[0152] FIG. 2 shows electrode 3 , made of perforated titanium, with thickness 1.5-2 mm. FIG. 3 shows electrode 4 , made of perforated titanium, with thickness 1.5-2 mm. Electrode 3 is the anode, the other electrode 4 is the cathode. The configuration or the geometric shape of the anode and cathode is made in the shape of a rectangular serpentine spring. Titanium catalyst electrode 3 at the same time is the catalyst; it is made of titanium sheet. The cavitation effect is achieved by holes 29 , made in three different diameters: 4, 6 and 8 mm alternately, covering the entire surface of the electrodes 3 & 4 . A chosen configuration of electrodes 3 & 4 comprises seven sections and the series electrical connection of these sections. Size and shape of electrodes 4 are made accordingly to be inserted into electrode 3 . Distance between electrodes 3 & 4 is 1.5 mm, which is achieved by gasket 30 , FIG. 4 . Gasket 30 prevents contact between electrodes 3 & 4 and is made of dielectric material. FIG. 4 shows one suggested shape of gasket 30 , but gasket 30 may have any shape. Its thickness is 1.5 mm, and it could be made of teflon, ceramic, porcelain, etc. Each section of the cartridge may contain minimum four gaskets. Voltage is supplied to electrodes 3 and 4 . Electrolyzer is composed of electrodes 3 and 4 , together with gaskets 30 , submerged in the water, where electrode 3 is the anode, and electrode 4 is the cathode. Electrodes 3 and 4 are also catalysts. Hydrodynamic cavitation occurs during the passage of the shock wave through the holes of electrolyzer's electrodes providing additional energy which contributes to the breaking of hydrogen bonds, wherein said electrodes are also cavitators in the cavitation reaction. Thus, the hydrogen reactor implements electro-hydraulic shock waves through electrodes 3 & 4 .
[0153] Configuration of electrolyzer's electrodes 3 & 4 was determined based on the functional requirements laid down in the hydrogen reactor; electrodes 3 & 4 are made of titanium and perform the functions of actual electrodes, catalysts and cavitators.
[0154] As is known electrolysis is a redox process. Electrolysis in our reactor takes place at the electrodes using the flow of direct electrical current through the electrolyte solution or the molten electrolyte.
[0155] FIG. 5 shows the frame 12 of the cartridge 5 made of a dielectric material. The process of cavitation occurs due to the main cartridge 5 . This reactor has seven cartridges 5 . Frame of the cartridge 5 has 3 sections/chambers: 39 , 40 and 41 . Each section/chamber carries out its function. Ledges 16 and 48 together create cavities which include perforated aluminum plates 7 , which are parallel to each other. Sections/chambers 39 and 41 have four plates 7 each, therefore, each cartridge 5 having eight aluminum plates 7 . Four plates 7 to the left and four plates 7 to the right of the electro-hydraulic electrodes holder 6 . Six ports/opening 10 A with inserted electrodes 42 - 47 multiplied by seven sections of electrode 4 inserted into electrode 3 , FIGS. 2 & 3 create forty-two (42) micro-volumes. Electro-hydraulic electrodes holder 6 is inserted in the section/chamber 40 of the cartridge 5 and is located in the middle of the frame 12 .
[0156] FIG. 6 shows a six-discharge electrode assembly in the electro-hydraulic electrodes holder 6 for alternately inducing electro-hydraulic percussion or shock. This reactor has seven electro-hydraulic electrodes holders 6 . Electro-hydraulic electrodes holder 6 is made of a dielectric material. It is in the form of a parallelepiped. It has technological rectangular cavity 11 , which extends across three quarters of the electro-hydraulic electrodes holder 6 . Technological rectangular cavity 11 is hollowed out along the diagonal of the body 8 or at an angle of 45 degrees to the bottom surface of the housing 8 . In the body 8 of electro-hydraulic electrodes holder 6 six vertical ports 10 A are arranged uniformly from the top of the frame, where vertical ports 10 B are arranged uniformly from the bottom. They serve as nests for electrodes with six electrodes inserted at the top and six electrodes at the bottom in each of seven electro-hydraulic electrodes holders 6 . Then, all the electrodes are inserted through the lid 31 , (see FIG. 7 ), which is top part of the electro-hydraulic electrodes holder 6 .
[0157] Synchronicity of the impulse is according to the number of electrodes 42 - 47 , FIG. 6 . The whole process continues without interruption because aluminum plates 7 are not covered by the oxidation film due to oxidation film being continuously broken by electro-hydraulic shock. That is, the oxidation process of aluminum occurs but the oxide film formed on the aluminum plates 7 gets broken by electro-hydraulic shocks and the plates continue to displace hydrogen from water. The ends of the electrodes 42 - 47 working in the hollow cavity 11 should have hemispherical shapes so that the charges would not discharge. In this hydrogen reactor electrohydraulic percussions implemented through electrodes 42 - 47 .
[0158] Process continues without interruption due to the fact that the aluminum plates 7 are not covered by the oxidation film. Ports 10 A and 10 B are for electrodes. Length of them changed proportionally along the line of the rectangular cavity 11 . Depending on the angle of the rectangular cavity 11 , length of the ports 10 A, ports 10 B and electrodes 42 - 47 changes. The interelectrode distance (the distance between the heads-up of electrodes) in the center of the rectangular cavity 11 is 1.5-2 mm. Electrode heads must be semi spherical. Negative wire 21 is connected to all six electrodes installed at the bottom of electro-hydraulic electrodes holder 6 in sequence.
[0159] Due to the electro hydraulic shock formed when submitting an electrical pulse to the electrodes 42 - 47 and 52 - 57 of electro-hydraulic frame 6 , there is electro-hydraulic effect that accompanied by the formation of plasma and release of light energy, heat, high pressure and ionization of the liquid.
[0160] This powerful electro-hydraulic shock distributed by forty two (42) electrodes powered by a pulse generator.
[0161] FIG. 7 shows the cover/lid 31 . It is connected to the body 8 (see FIG. 6 ). It also has six vertical ports/openings 10 C; they are parallel to the openings/ports 10 A of the body 8 . Electrodes are inserted into these ports. Positive wires 14 - 19 connected to the electrodes 42 - 47 (see FIG. 6 ) and to the bottom pats of the High Voltage Multipin Connector 13 . High Voltage Multipin Connector 13 is located in the middle of the cover/lid 31 and serves as high voltage impulse to the electrodes in several microseconds. The electrodes must be made of conductive material.
[0162] FIG. 8 shows the cover 27 of the reactor's housing/corpus 1 (see FIG. 1 ). Since a positive charge is applied to the lid/cover of reactor and negative charge is applied on the housing/corpus of the reactor, thus an electro-static field occurs, which orders the process of movement of positively and negatively charged ions in different directions. The electromagnetic field is the result of an orderly movement of positively and negatively charged ions.
[0163] Between the housing/corpus 1 and the lid 27 fitted gas-tight gaskets 100 . The thermometer and pressure sensor-tridicator boiler gauges 22 are located on the surface of the cover 27 . A high pressure release valve 23 adjusts the pressure inside of the hydrogen reactor. An exhaust pipe 24 is a tube through which hydrogen is supplied to the consumer. Seven top parts of high voltage multipin connectors 13 are placed on the surface of the cover 27 . Said top parts of the high voltage multi pin connectors of the lid/cover of the reactor are connected to the bottom parts of high voltage multipin connectors located on the lid of the electro-hydraulic electrodes holder. An electro-impulse dispenser 26 is situated on the cover 27 , which transmits impulses to the electrolyzer's electrodes synchronously through high voltage multipin connectors 13 . Impulses are supplied simultaneously to all the first electrodes of all seven electro-hydraulic electrodes holders 6 ; then, to all second and so on until the last electrode. 28 is reactor's closure/latch to seal reactor tightly. The electro-impulse dispenser 26 creates powerful shocks by affecting the electrodes. The female part of the connector 13 is attached to the lid 27 of reactor; and the male part of the connector 13 is attached to the electro-hydraulic electrodes holder 6 . Contact wires 32 - 38 connected to the electro-impulse dispenser 26 .
[0164] FIG. 9 shows is a schematic view of the system of the multifunctional hydrogen reactor in accordance with the present invention.
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The present application provides a device for generating hydrogen gas having a plurality of discharge electrode pairs, at least a first oxidation element and a second oxidation element, and at least one electrolysis electrode pair. The at least one electrolysis electrode pair is configured to perform electrolysis by flowing an electric current through the water and using heat generated by the oxidation of the first and second oxidation elements.
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FIELD OF THE INVENTION
This invention relates to amide analogs of calcitonin having biological activity and particularly having extended duration of activity.
BACKGROUND OF THE INVENTION
All known natural calcitonin peptides contain an amino acid sequence of 32 amino acids. Salmon calcitonin, for example, has the following formula: ##STR1##
In U.S. Pat. Nos. 3,926,938, 4,062,815, 3,929,758, 4,033,940 and 4,217,268 are disclosed improved syntheses of calcitonins including the salmon calcitonin referred to above.
The natural calcitonins include the salmon, eel, bovine, porcine, ovine and human calcitonins. For exemplification of the structures of the various calcitonins, see U.S. Pat. No. 4,422,967, Col. 3, which is hereby incorporated by reference.
SUMMARY OF THE INVENTION
We have discovered that amide analogs of calcitonin have biological activity of the same type as known calcitonins but with extended duration of activity.
Amide analogs of salmon calcitonin: ##STR2## wherein X and Y are as defined below.
Amide analogs of eel calcitonin: ##STR3## wherein X and Y are as defined below.
Amide analogs of human calcitonin: ##STR4## wherein X is H or a branched or linear alkanoyl having 2-20 carbon atoms, wherein the alkyl of alkanoyl may be substituted with a phenyl or hydroxy group and wherein
Y is defined as X with the proviso that if all other X substitutions are H, Y is C 8 -C 20 alkanoyl, wherein the alkyl of alkanoyl may be substituted with a phenyl or hydroxy group.
Including within the present invention are also the corresponding bovine, porcine, ovine and rat calcitonin analogs.
Monikawa et al. [Experientia, 32(9), 1104-1106 (1976)] showed that synthetic eel calcitonin has a hypocalcemic potency around 4300 Iu/mg., while the synthetic analog (1,7-α-L-aminosuberic acid)eel calcitonin has a hypocalcemic potency of about 3400 Iu/mg.
Therefore, we also include within the present invention the 32 amino acid analogs of salmon and eel calcitonin in which the first and seventh cysteines are replaced by α-L-aminosuberic acid and the amino groups have been acylated individually, severally or totally.
In addition, we also include analogs of all the aforementioned calcitonins where the L-lysine residues have been replaced by D-lysine, individually or totally and similar acylated or partially acylated compounds.
Orlowski, et al. (U.S. Pat. No. 4,469,632) has shown that if Arg (24) of salmon calcitonin is replaced by D-Arg, there is no significant loss of activity; the hypocalcemic potency is 5000 IU/mg. Therefore, we also include similar analogs of salmon or eel calcitonin to those already described where Arg (24) is replaced by D-Arg (24).
Approved human medical uses for salmon calcitonin include treatment of Paget's disease and osteoporosis.
DETAILED DESCRIPTION OF THE INVENTION
As may be seen from the formula given above, 32 amino acids are involved and in this formula the positions are numbered according to the accepted procedure beginning at position 1 for the Cys on one end of the chain, and ending with Pro at position 32 at the other end of the chain. For clarity of description, this same numbering system will be followed in referring to the cycles of the synthesis. The assembly of the amino acids begins with cycle 32 which involves the coupling of proline and continues with cycle 31 which involves the coupling of threonine, etc.
The amide analogs of calcitonin are formed at the peptide positions having a lysine or arginine, or at the cysteine at position one.
In salmon and eel calcitonin, lysines are at the 11 and the 18 positions and arginine is at the 24 position. Therefore, various mono, di, tri and tetra amides are possible.
In human calcitonin, lysine is only in the 18 position. Therefore, various mono and di amides are possible.
The alkanoyl of X may be straight-chained or branched and include acetyl, propanoyl, butanoyl, isobutanoyl, tertbutanoyl, 2,2-dimethylpropanoyl, dimethylbutanoyl, 2,5-dimethyloctanoyl, 2,2,6,6-tetramethyldecanoyl, 2,isopropylpentanoyl, 3,3-dimethylheptanoyl, dodecanoyl, 2,4-diethylundecanoyl, 2,2-dimethylpentanoyl, decanoyl, and pivalyl.
The alkyl of the alkanoyl may be substituted with a phenyl or hydroxy group.
Y is defined as X is above except if the other X substitutions are H when Y has a C 8 -C 20 alkanoyl. The alkyl of this alkanoyl may also be substituted with a phenyl or hydroxy group.
Preferred compounds include:
N(α)-decanoyl-Cys(1) salmon calcitonin;
N(ε)-decanoyl-Lys(18) salmon calcitonin;
N(α)-decanoyl-Cys(1)-N(ε)-decanoyl-Lys(11)-N(ε)-decanoyl-Lys(18) salmon calcitonin;
N(α)-pivalyl-Cys(1)-N(ε)-pivalyl-Lys(11)-N(ε)-pivalyl-Lys(18) salmon calcitonin.
N(α)-decanoyl-Cys(1)-N(ε)-decanoyl-Lys(11)-N(ε)-decanoyl-Lys(18)-N(ω)-decanoyl-Arg(24) salmon calcitonin
N(α)-pivalyl-Cys(1)-N(ε)-pivalyl-Lys(11)-N(ε)-pivalyl-Lys(18)-N(ω)-pivalyl-Arg(24) salmon calcitonin
Resin Peptide Synthesis
The amino acid chain sequence may be assembled by use of classical synthesis techniques or by solid phase techniques. For exemplification, the salmon calcitonin structure is used. However, these procedures can also be used for eel, human, bovine, porcine, ovine or any analogs of calcitonin.
Preferably, the peptide is assembled using solid phase synthesis. One can start with a resin called benzhydryl amine resin (BHA resin). This resin is derived from a cross-linked polystyrene bead resin manufactured by copolymerization of styrene and divinylbenzene. Resin of this type is known and its preparation is further demonstrated by Pietta et al. [Pietta, P. S. and Marshall, G. R., Chem. Commun., 650 (1970)], and Orlowski et al., [J. Org. Chem., 41, 3701 (1976)]. The cross-linked polystyrene BHA resin is available from chemical supply houses. The designation ##STR5## represents the BHA resin in which ○P is the polystyrene portion of the resin.
Alternatively, one can start from a resin which is an amino-methyl resin instead of a BHA resin.
The assembly of the resin-peptide from amino-methyl resin preferably includes a step in which a "handle" of the type described by Gaehde and Matsueda (Int. J. Peptide Protein Res. 18, 451-458 (1981)) is incorporated between the resin and the terminal amino acid of the polypeptide. More preferably, norleucine is incorporated between the resin and the "handle" as an internal reference standard.
Thus, BOC-Nle is reacted with the resin in the presence of dicyclohexylcarbonyldiimide (DCCI) and hydroxybenzotriazole (HOBT) to form ##STR6## The BOC group is removed by adding acid to this product (such as HCl in dioxane or trifluoroacetic acid in toluene or in methylene chloride) and then neutralizing with e.g. diisopropylamine. Then the BOC-protected "handle", ##STR7## DCCI and HOBT are added to couple the BOC-handle to the deprotected norleucine residue. Following removal of the BOC group from the handle, by acidification and neutralization, cycle 32 begins in which BOC-proline is coupled to the deprotected nitrogen of the "handle".
In general, each amino acid is reacted with the resin peptide in a suitable solvent such as toluene, chloroform, methylene chloride, or dimethyl formamide, in the presence of a coupling agent, and subsequently deprotected with acid followed by a neutralizing step; then the next amino acid is added, and so forth.
The amino acids are added one at a time to the insoluble resin until the total peptide sequence has been built up on the resin. The functional groups of the amino acids are protected by blocking groups. The α-amino group of the amino acids is protected by a tertiary butyloxycarbonyl group or an equivalent thereof. This α-tertiary butyloxycarbonyl group we designate as BOC. The hydroxyl functions of serine and threonine are protected by a benzyl or benzyl derivative group such as 4-methoxybenzyl, 4-methylbenzyl, 3,4-dimethylbenzyl, 4-chlorobenzyl, 2,6-dichlorobenzyl, 4-nitrobenzyl, benzhydryl or an equivalent thereof. We use the term Bzl to represent the benzyl or benzyl derivative group.
The hydroxyl function of tyrosine may be unprotected, may be protected by a benzyl or benzyl derivative group as described above, as a Bzl group, or may be protected by a benzyloxycarbonyl or a benzyloxycarbonyl derivative such as 2-chlorobenzyloxycarbonyl or 2-bromobenzyloxycarbonyl group or equivalent thereof.
The thiol function of cysteine may be protected by benzyl or benzyl derivative protective groups described above and designated Bzl, and preferably p-methylbenzyl or p-methoxybenzyl; or by an alkylthio group such as methylthio, ethylthio, n-propylthio, n-butylthio, t-butylthio or equivalents thereof or another cysteine group. One cysteine, preferably Cys(7), is protected by Bzl and the other, preferably Cys(1), is protected by an alkylthio group. The guanidine function of arginine may be protected by a nitro group, a tosyl group or an equivalent thereof. The ε-amino function of lysine may be protected preferably by FMOC (9-fluorenylmethyloxycarbonyl) or by a benzyloxycarbonyl group or a benzyloxycarbonyl derivative such as a 2-chlorobenzyloxycarbonyl, 3,4-dimethylbenzyloxycarbonyl, or equivalents thereof. The protective groups used on the imidazole nitrogen of histidine are tosyl, benzyloxymethyl, or benzyloxycarbonyl. The γ-carboxylic acid group of glutamic acid is protected by a benzyl or benzyl derivative group such as described for the protection hydroxyl function of serine and threonine.
The invention will be described herein with particular reference to the synthesis of derivatives of salmon calcitonin.
As may be seen from the formula given above for salmon calcitonin, 35 amino acids are involved and in this formula the positions are numbered according to the accepted procedure beginning at position 1 for the Cys on one end of the chain, and ending with Pro at position 32 at the other end of the chain. For clarity of description, this same numbering system will be followed in referring to the cycles of the synthesis. The assembly of the amino acids of salmon calcitonin begins with cycle 32 which involves the coupling of proline and continues with cycle 31 which involves the coupling of threonine, etc.
Preferred amino acid reactants for use in each of the 32 cycles of the synthesis of salmon calcitonin derivatives of the present invention (used for exemplification only) are given in the following Table I:
TABLE I______________________________________Cycle-Num-ber Amino Acid Reactant______________________________________32 BOC-- .sub.--L-proline31 BOC--O--benzyl- .sub.--L-threonine30 BOC--glycine29 BOC--O--benzyl- .sub.--L-serine28 BOC--glycine27 BOC--O--benzyl- .sub.--L-threonine26 BOC-- .sub.--L-asparagine25 BOC--O--benzyl- .sub.--L-threonine24 BOC--ω-tosyl- .sub.--L-arginine23 BOC-- .sub.--L-proline22 BOC--O--bromobenzyloxycarbonyl- .sub.--L-tyrosine21 BOC--O--benzyl- .sub.--L-threonine20 BOC-- .sub.--L-glutamine19 BOC-- .sub.--L-leucine18 BOC--ε-2-chlorobenzyloxycarbonyl- .sub.--L-lysine or BOC--ε-decanoyl- .sub.--L-lysine or BOC--ε-9-fluorenylmethyloxycarbonyl- .sub.--L-lysine17 BOC--N(im)-CBZ--7 .sub.--L-histidine16 BOC-- .sub.--L-alanine15 BOC-- .sub.--L-glutamic acid γ-benzyl ester14 BOC-- .sub.--L-glutamine13 BOC--O--benzyl- .sub.--L-serine12 BOC-- .sub.--L-leucine11 BOC--ε-2-chlorobenzyloxycarbonyl- .sub.--L-lysine or BOC--ε-decanoyl- .sub.--L-lysine or BOC--ε-9-fluorenylmethyloxycarbonyl- .sub.--L-lysine10 BOC--glycine 9 BOC-- .sub.--L-leucine 8 BOC-- .sub.--L-valine 7 BOC--S--p-methoxybenzyl- .sub.--L-cysteine, BOC--S--3,4- dimethylbenzyl- .sub.--L-cysteine or BOC--S--p- methylbenzyl- .sub.--L-cysteine 6 BOC--O--benzyl- .sub.--L-threonine 5 BOC--O--benzyl- .sub.--L-serine 4 BOC-- .sub.--L-leucine 3 BOC-- .sub.--L-asparagine 2 BOC--O--benzyl- .sub.--L-serine 1 BOC--S--ethylthio- .sub.--L-cysteine, BOC--S--methylthio- .sub.--L cysteine, BOC--S--n-propylthio- .sub.--L-cysteine or BOC--S-- n-butylthio- .sub.--L-cysteine______________________________________
Each of the amino acid derivatives mentioned in Table I may be purchased from supply houses with the exception of BOC-ε-decanoyl-L-lysine.
A process for making BOC-ε-decanoyl-L-lysine is as follows:
Preparation of Succinimidyl n-Decanoate
n-Decanoyl chloride, 13.4 g, 70 mmoles was dissolved in methylene chloride, 350 ml. The mixture was chilled to -5°-0° C. in a salt-ice bath. With concomitant stirring and cooling, the potassium salt of N-hydroxipuccinimide, 15.3 g, 100 mmoles was added to the solution in portions such that the temperature did not exceed 5° C. The mixture was stirred at room temperature for a further two hours, after which the insoluble potassium chloride was filtered off. The filtrate was evaporated to dryness and the residue dissolved in ethyl acetate. The solution was washed with water, dried over magnesium sulfate and evaporated. Trituration of the residue with ether afforded a white crystalline solid, 21.7 g (90% of theory), m.p. 63° C. The NMR and mass spectra were consistent with the structure.
Preparation of BOC ε-decanoyl-L-lysine
BOC-L-Lysine, 2.46 g, 10 mmoles was suspended in DMF, 50 ml. To this was added tetramethylguanidine, 3.5 ml and the whole mixture was heated to 40°-50° C. until a homogeneous solution was obtained. Succinimidyl n-decanoate, 4 g, 15 mmoles, was added portionwise such that the temperature did not exceed 50° C. The solution was left overnight at room temperature. The DMF was removed in vacuo and the residue was partitioned between ethyl acetate and 0.5N sulfuric acid. The organic extract was washed successively with 0.5N sulfuric acid and water, dried (MgSO 4 ) and evaporated to give a yellowish oil.
This oil was dissolved in methylene chloride, 10 ml. To this was added N sodium hydroxide solution, 15 ml, plus water, 10 ml. After shaking vigorously, the organic layer was separated and discarded. The aqueous layer was washed with methylene chloride and then was acidified with 0.5N sulfuric acid. The desired product separated as an oil. This was extracted into ethyl acetate, washed successively with water and saturated sodium chloride solution, dried (MgSO 4 ) and evaporated to a colorless oil, which slowly crystallized when triturated with hexane. The crude solid was recrystallized from ether-hexane to afford 3.63 g product, 91% of theory, m.p. 73° C. The NMR and mass spectra were consistent with the structure.
EXAMPLE 1
N(α)decanoyl-Lys(18) salmon calcitonin
Neutralization of Amino-methyl resin
An 11.0 g sample of aminomethyl resin hydrochloride, corresponding to approximately 10 mmoles amine groups (i.e. with a substitution of 0.9 milliequivalents of amine groups per gram of resin) was placed in the reaction vessel of a Vega Model 50 Peptide Synthesizer (Vega Biochemicals, Division of Vega Laboratories Inc., P.O. Box 11648, Tucson, Ariz. 85734). The resin was swollen by shaking in methanol (150 ml) for five minutes and then was washed with methylene chloride (3×150 ml, 1 minute each) and with 15% methanol in methylene chloride (150 ml) for one minute. It was treated with 5% di-isopropylamine (DIA) in methylene chloride (150 ml) for 1 minute. It was washed once with 15% methanol in methylene chloride (150 ml, 1 minute) then retreated with 5% DIA in methylene chloride (150 ml, 1 minute). This washing and base treatment was repeated and then the resin was washed six times with methylene chloride (150 ml, 1 minute each).
Removal of α-BOC Group
This was performed using 50% v/v trifluoroacetic acid in methylene chloride, preferably in the presence of 2% v/v 2-mercaptoethanol.
The BOC-protected resin is treated as follows:
______________________________________Methylene chloride + 2% v/v 2- 3 × 150 ml 1 minutemercaptoethanol50% v/v TFA in methylene chloride 2 × 150 ml 1 × 1 min.,+ 2% v/v 2-mercaptoethanol 1 × 30 min.Methylene chloride + 2% v/v 2- 3 × 150 ml 1 minutemercaptoethanolMethanol (15% v/v) in methylene 6 × 150 ml 1 minutechlorideDi-isopropylamine (5% v/v) in 2 × 150 ml 1 minutemethylene chlorideMethanol (15% v/v) in 3 × 150 ml 1 minuteMethylene ChlorideDi-isopropylamine (5% v/v) in 1 × 150 ml 1 minutemethylene chlorideMethylene Chloride 6 × 150 ml 1 minute______________________________________
Addition of N-Boc-p-(α-aminophenylmethyl)phenoxyacetic acid, the "handle"
To the neutralized resin, containing 10 mmoles amino groups, was added the acylating solution containing 20 mmoles of the title compound. This acylating solution was prepared by dissolving the title compound (7.14 g, 20 mmoles) and 1-hydroxybenzotriazole, HOBT, (3.9 g, 25 mmoles) in dimethyl acetamide, 45 ml. To this was added methylene chloride, 100 ml, and the solution was cooled to 0°-5° C. 10 ml of a solution of 2M dicyclohexylcarbodiimide, DCCI, in toluene were added and the mixture was kept at room temperature for 30 minutes. Dicyclohexylurea was filtered off and the filtrate added to the resin.
The mixture was shaken overnight for convenience, although a coupling time as short as one hour would be adequate. The resin was drained and washed for one minute each time with three 150 ml portions of methylene chloride, six 150 ml portions of methanol and six 150 ml portions of methylene chloride. A ninhydrin test [Kaiser et al, Anal. Biochem. 34, 595-8 (1969)] was performed and on all but one occasion was found to be negative. If it should have been even slightly positive, recoupling would have been performed or the resin would have been acetylated. On the occasion that one bead was dark, acetic anhydride, 15 ml, pyridine, 15 ml and methylene chloride, 150 ml, were shaken with the resin for fifteen minutes. The resin was washed as just described for the coupling reaction.
Addition of Pro 32, Thr 31, Gly 30, Ser 29, Gly 28, Thr 27, Asn 26, Thr 25, Arg 24
In general, each of these residues was incorporated as described for the "handle" and the BOC groups were removed similarly using TFA.
Completeness of coupling of Thr (31) to Pro (32) and of Tyr (22) to Pro (23) was monitored by the isatin test (Kaiser E., Bossinger C. D., Colescott, R. L. and Olsen, D. B., Analytica Chimica Acta., 118, 149 (1980)).
Addition of Pro (23), Tyr (22), Thr (21), Gln (20), Leu (19), Lys (18)
In general, each of these residues was incorporated as described for the "handle" except that dimethyl formamide was used for the coupling solvent. The BOC group was removed using TFA.
Addition His (17)
The acylating solution was prepared as for the "handle" but using dimethyl formamide as solvent. However, after adding the solution of DCCI in toluene, the cold solution was added immediately to the resin.
Addition of all other residues
In general, each of these residues is incorporated as described for the "handle" except that dimethyl formamide is used for the coupling solvent. After Cys(7) is added, it is essential that 2-mercaptoethanol be present during acid deblocking treatments.
In the above, Lys (18) is protected with decanoyl and Lys (11) with the ε-2-chloro-benzyloxycarbonyl group.
After incorporation of Cys (1), the BOC group is not removed, but is left on to be removed during HF cleavage.
Addition of Lys (11) using ε-FMOC and all subsequent residues
Acylating solutions are prepared as described for the "handle" but dimethyl acetamide is preferred as coupling solvent.
The preferred method for deblocking is to use TFA and for neutralization, all di-isopropylamine in methylene chloride treatments were replaced by 5% v/v triethylamine in methylene chloride treatments, and each of these were for only ten seconds.
After incorporation of Cys (1), the BOC group is not removed with TFA but is left on, to be removed during the HF cleavage. As FMOC is being used, this must be removed before HF cleavage, for instance using this procedure:
Treat the resin as follows:
______________________________________wash with DMF 3 × 1 min. × 150 ml10% Piperidine in DMF 1 × 1 min., 1 × 15 min. 200 ml eachDMF 3 × 1 min. × 150 mlCH.sub.2 Cl.sub.2 6 × 1 min. × 150 ml______________________________________
Cleavage of Resin Peptide with Hydrogen Fluoride
The dried resin peptide (2 g.) and 2 ml. of m-cresol and 2 ml of 1,2-ethanedithiol were placed in a Teflon reaction vessel. The vessel equipped with a Teflon-coated magnet stirrer was placed in a liquid nitrogen or dry ice-acetone bath and 10 ml. of hydrogen fluoride gas was condensed into the vessel. This mixture was stirred at 0 degrees centigrade in an ice bath for 1 hour. The hydrogen fluoride was removed by evaporation at reduced pressure. The residue was triturated with six 25 ml. portions of ethyl acetate. The residue was dried in vacuo.
Cyclization of the Peptide
The resin peptide mixture obtained from hydrogen fluoride cleavage was mixed with 1000 ml of distilled water. The pH of the solution was adjusted to 8.5 by the addition of concentrated ammonium hydroxide. The solution was stirred in a closed vessel under a stream of nitrogen for 20 hours. At this time no ethyl mercaptan could be detected in the emerging nitrogen stream. The ethyl mercaptan content of the nitrogen stream was measured by passing the stream through a solution of Ellman's reagent [Ellman, G. L., Arch. Biochem. Biophys., 82, 70-7 (1969)]. The pH of the reaction mixture was adjusted to 4.0 by addition of glacial acetic acid and freeze-dried affording a fluffy solid.
Purification of the Crude ε-decanoyl-Lys(18)-SCT
The fluffy solid from the above synthesis was dissolved in a small amount of 0.5N acetic acid and purified by passing through a Sephadex G-25 (fine) gel-filtration column and eluting with 0.5 molar aqueous acetic acid solution. The decanoyl-Lys(18)-SCT fraction from this column was freeze-dried and the resulting fluffy solid dissolved in ammonium acetate solution. This solution was further purified by ion-exchange chromatography using a Whatman CM-52 column eluted with ammonium acetate buffer. The peptide fraction was collected and freeze-dried. The product was further purified by preparative isocratic high performance liquid chromatography using a Zorbax C 8 column and the solvent system: 0.1% of trifluoroacetic acid in H 2 O/acetonitrile (50/50, v/v). The fractions containing the product were combined and the acetonitride moved by evaporation. The product was recovered by lyophilization.
The product was obtained as a fluffy white solid and proved to be over 95% homogeneous by both molecular exclusion and reverse phase HPLC methods.
EXAMPLE 2
Preparation of N(α)-Decanoyl-Cys(1)-N(ε)-Decanoyl-Lys(11)-N(ε)-Decanoyl-Lys(18)-Lys(11)-N(ε)-Decanoyl-Lys(18)-Salmon Calcitonin
Salmon calcitonin, 100 mg, (approx. 0.03 mM) was dissolved in 5 ml of water and the pH was adjusted to 7.0 with phosphate buffer. This solution was chilled to 0°-5° C. in an ice-bath. To this solution was added a solution of 80 mg (0.3 mM) of N-hydroxysuccininide n-decanoate in 2 ml of tetrahydrofuran. The mixture was kept stirring at 0° C. for 20 hours and at room temperature for an additional 5 hours. A small amount of solid sodium bicarbonate was added to maintain the pH of the mixture at 7-8. At the end of this period, no starting salmon calcitonin could be detected by T.L.C., and the mixture was freeze-dried. The residue was taken up in 5 ml of 25% acetic acid and purified by passing through a Sephadex G-25 (fine) column eluting with 25% aqueous acetic acid. The peptide fractions were combined and freeze-dried. The product was obtained as a fluffy white solid.
EXAMPLE 3
Preparation of N(α)-Decanoyl-Cys(1)-Salmon Calcitonin
This compound was prepared by solid phase peptide synthesis using methods similar to N(ε)-decanoyl-Lys(18)-SCT, but using ε-2-chlorobenzyloxycarbonyl for protection of Lys(18). After completion of the peptide sequence, the BOC group was removed from Cys(1). n-Decanoic acid was coupled onto Cys(1) in the standard way using DCCI/HOBT. The subsequent HF-cleavage, cyclization and purification, were also performed as described in the previous sections for N(ε)-decanoyl-Lys(18)-SCT.
EXAMPLE 4
Preparation of N(ε)-Pivalyl-Cys(1)-N(ε)-Pivalyl-Lys(11)-N(ε)-Pivalyl(18)-Salmon Calcitonin
This compound was prepared as for the corresponding tridecanoyl substituted salmon calcitonin except that N-hydroxysuccinimide pivalate was utilized as acylating agent. Purification was performed by gel-filtration on Sephadex G-25 exactly as for the tridecanoyl analog.
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New peptides are disclosed which have biological activity of the same type as known calcitonins and which are amide analogs of natural calcitonins.
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TECHNICAL FIELD
The present invention relates to a multi-issue processor comprising: a plurality of issue slots, each one of the plurality of issue slots comprising a plurality of functional units and a plurality of holdable registers, the plurality of issue slots comprising a first set of issue slots and a second set of issue slots; and a register file accessible by the plurality of issue slots.
BACKGROUND ART
Multi-issue processors exhibit a lot of parallel hardware to enable the concurrent execution of multiple operations in a single processor cycle and thus exploiting instruction-level parallelism in programs. Examples of multi-issue processors are VLIW (Very Large Instruction Word) processors and superscalar processors. In case of a VLIW processor, the software program contains full information regarding which operations should be executed in parallel and these operations are packed into one very long instruction. The compiler ensures that all dependencies between operations are respected and that no resource conflicts can occur. Apart from this program information the hardware does not require any additional information to correctly execute the program, which results in relatively simple hardware. In case of a superscalar processor the software to be executed is presented as a program composed of a sequential series of operations. The processor hardware itself determines at runtime which operation dependencies exist and decides which operations to execute in parallel based on these dependencies, while ensuring that no resource conflicts will occur. A relatively simple compiler suffices for translating a high-level programming language to sequential code, but the processor hardware is very complex.
In multi-issue processors, the parallel hardware responsible for executing these operations is organized in issue slots. Each issue slot contains one or more functional units that perform the actual operations. Commonly, in every processor cycle a single operation is started on one functional unit in every issue slot. In some processors more than one functional unit is put in an issue slot as a trade-off between maximum available parallelism and instruction width cost, in case of a VLIW processor, or hardware complexity, in case of a superscalar processor.
Since in each clock cycle at most one operation can be started on one functional unit in each issue slot, power may be wasted by functional units in that issue slot that are not being used in a given processor cycle. If the input of these functional units changes during the time that they are not used they will still consume comparable power to when they are being used, even though their output is irrelevant.
This waste of power can be eliminated by putting holdable registers, i.e. a register, the state of which remains unchanged in case of a different input, at the inputs of all functional units within an issue slot. These holdable registers will leave the inputs of the functional units unchanged, when these functional units are not being used. Since the inputs of these functional units remain unchanged, no combinatorial gates are switched and no dynamic power dissipation occurs. These holdable registers can be implemented, for example, by means of clock gating. Another advantage of these registers is that the additional pipeline stage they are forming allows running the processor at a higher clock frequency. A disadvantage of adding registers to all inputs of functional unit inputs is that it increases the amount of state that must be saved during interrupts. An interrupt allows a processor to quickly respond to external events and it causes the processor to temporarily postpone the further execution of the current program trace and instead perform another trace. The state of the postponed trace must be saved such that, when the interrupt has been serviced, the processor can restore its original state and can correctly proceed with the original trace. In order to obtain a predictable and short interrupt latency, it must always be possible to interrupt the processor whenever desired. This is especially important in real-time applications. Interrupting a processor at an arbitrary point in the program can imply that a significant amount of state must be saved.
The non-prepublished European patent application 00203591.3 [attorneys' docket PHNL000576], filed on 18 Oct. 2000, provides a solution for decreasing the amount of state that must be saved during interrupts. A second compact instruction set is applied, that is used in an interrupt service routine and only uses a limited set of processor resources. In case of an interrupt, it is sufficient to save the state of only the limited set of processor resources used by the second compact instruction set, while simply freezing the state in all other resources. However, the resources used by the second compact instruction set still have a considerable amount of state that must be saved and restored during interrupts, when registers are put at all the inputs of each functional unit in this limited set of resources.
DISCLOSURE OF INVENTION
An object of this invention is to provide a solution to further reduce the amount of state that must be saved during interrupt handling for multi-issue processors, while maintaining a significant reduction in power consumption and improved performance.
This object is achieved with a multi-issue processor of the kind set forth characterized in that a location of at least a part of the plurality of holdable registers in the first set of issue slots is different from a location of at least a corresponding part of the plurality of holdable registers in the second set of issue slots.
Ideally, the holdable registers are put at all inputs of each functional unit within an issue slot. In that case it is guaranteed that each input of a functional unit, that is not being used, will remain unchanged and no unnecessary power dissipation will occur. However, this increases the amount of state that has to be saved during interrupt handling. By varying the position of the holdable registers for different issue slots, and not putting a holdable register in front of all inputs of every functional unit, less state saving is required during interrupt handling. This may result in a lower reduction of the power consumption or a reduced increase in performance. Depending on the type of application an optimal choice between these demands can be made.
An embodiment of the invention is characterized in that the multi-issue processor further comprises a first instruction set means having access to the first set of issue slots and a second instruction set means having access to the second set of issue slots. An advantage of this embodiment is that the location of the holdable registers in an issue slot can be made dependent of the instruction set means that controls this issue slot. If the second instruction set means is used in an interrupt service routine, the holdable registers in the second set of issue slots can be positioned to optimally reduce the amount of state that must be saved during interrupt handling. However, this solution is not optimal for reduction of the power consumption. The positioning of the holdable registers still creates an additional pipeline stage enabling an increase in the clock frequency of the processor. Many interrupts require very simple interrupt service routines and therefore a compact second instruction set using a limited set of issue slots is sufficient. Therefore the non-optimal reduction in power consumption only holds for a small set of issue slots within the multi-issue processor. The first set of issue slots is not used during interrupt handling and as a result their state does not have to be saved. The holdable registers can be placed to optimally reduce the power consumption and increasing the clock frequency by creating an additional pipeline stage. For the overall processor this results in a well-balanced consideration between increasing performance, decreasing power consumption and reducing state saving overhead.
An embodiment of the invention is characterized in that in the first set of issue slots the location of the plurality of holdable data registers is at individual data inputs of the functional units, while in the second set of issue slots the location of the plurality of holdable data registers is at common data inputs of the functional units. An advantage of this embodiment is that the amount of state that has to be saved during interrupt handling is strongly reduced, since the holdable registers are not positioned at all individual inputs of the functional units of the second set of issue slots, but only at their common inputs. However, the use of one functional unit of an issue slot of the second set of issue slots results in changing inputs at the other functional units of that issue slot and therefore causes unnecessary power dissipation. In case that entire issue slot is not being used, the functional units will consume no power. In the first set of issue slots the holdable registers are positioned at all inputs of the functional units to optimally reduce power consumption, resulting in a significant overall reduction in the power consumption. Furthermore, the holdable registers in the first and second set of issue slots form an additional pipeline stage in the architecture, allowing the processor to run at a higher clock frequency. As a result, a good compromise is obtained between reduction in power consumption, increase in performance and reduction in the amount of state that has to be saved during interrupt handling.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the described embodiments will be further elucidated and described with reference to the drawings:
FIG. 1 is a schematic diagram of a VLIW processor.
FIG. 2 is a schematic diagram of issue slot UC 1 , UC 2 and UC 3 only used by a first instruction set.
FIG. 3 is a schematic diagram of issue slot UC 0 used by a second instruction set, during interrupt handling.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 , a schematic block diagram illustrates a VLIW processor comprising a plurality of issue slots, including issue slots, UC 0 , UC 1 , UC 2 and UC 3 , and a distributed register file including register file segments RF 0 and RF 1 . The processor has a controller SQ and a connection network CN for coupling the register file segments RF 0 and RF 1 , and the issue slots UC 0 , UC 1 , UC 2 and UC 3 . The issue slots UC 0 , UC 1 , UC 2 and UC 3 are used by a first instruction set and this first instruction set includes the normal VLIW instructions. The issue slot UC 0 is the only issue slot that is used by a second instruction set. This second instruction set is used in an interrupt service routine.
Referring to FIG. 2 , a schematic block diagram illustrates issue slots UC 1 , UC 2 and UC 3 . Referring to FIG. 3 , a schematic block diagram illustrates issue slot UC 0 . Referring now to both FIG. 2 and FIG. 3 , each issue slot comprises a decoder DEC, a time shape controller TSC, an input routing network IRN, an output routing network ORN, and a plurality of functional units, including functional units FU 0 , FU 1 and FU 2 . The decoder DEC is coupled to the time shape controller TSC and to the functional units FU 0 , FU 1 and FU 2 . The input routing network IRN is coupled to the functional units FU 0 , FU 1 and FU 2 . The output routing network ORN is also coupled to the functional units FU 0 , FU 1 and FU 2 . The decoder DEC decodes the operation O applied to the issue slot in each clock cycle. Results of the decoding step are operand register indices ORI and the decoder DEC passes these indices to the connection network CN, shown in FIG. 1 . Further results of the decoding step are result file indices RFI and register indices RI. The decoder DEC passes these indices to the time shape controller TSC. The time shape controller TSC delays the result file indices RFI and the register indices RI by the proper amount, according to the input/output behavior of the functional unit on which the operation must be executed. Subsequently, the time shape controller TSC passes the result file indices RFI and the register indices RI to the connection network CN, shown in FIG. 1 . The decoder DEC also selects one of the functional units FU 0 , FU 1 and FU 2 to perform an operation, using the coupling SEL. Furthermore, the decoder DEC passes information on the type of operation that has to be performed to the functional units FU 0 , FU 1 and FU 2 , using the coupling OPT. The input routing network IRN passes the operand data OD for the issue slot UC 1 , UC 2 and UC 3 to the inputs of functional units FU 0 , FU 1 and FU 2 . The functional units FU 0 , FU 1 and FU 2 pass their output data to the output routing network ORN and subsequently the output routing network ORN passes the result data RD to the communication network CN, see FIG. 1 .
Referring to FIG. 2 , holdable registers 1 - 27 are provided directly at the data and control inputs of the functional units FU 0 , FU 1 and FU 2 . Holdable registers 1 - 5 , 11 - 15 , 21 and 23 are referred to as holdable data registers, since they are positioned at the data inputs of the functional units FU 0 , FU 1 and FU 2 . The holdable registers 1 - 27 will leave the inputs of the functional units FU 0 , FU 1 and FU 2 unchanged when a functional unit is not being used. As a result, no combinatorial gates are switched and no power dissipation occurs. Furthermore, to prevent result file indices RFI and register indices RI from changing unnecessarily, and thereby causing unnecessary power dissipation, holdable registers 29 , 31 and 33 are placed directly after the time shape controller TSC. An advantage of this embodiment is that it reduces the power consumption. In each clock cycle at most one operation can be started on one of the functional units FU 0 , FU 1 and FU 2 , and most functional units finish their operation in a single processor cycle. If the inputs of the functional units, that are not being used, change due to data passed via the input routing network IRN or the decoder DEC, these functional units will consume comparable power to when they are not being used, even though their output is irrelevant. Adding the holdable registers 1 - 33 creates additional state, but that is irrelevant for the issue slots UC 1 , UC 2 and UC 3 . During interrupts, their state only has to be frozen. The holdable registers 1 - 33 do only incur additional area. These registers do not waste additional power due to using clock gating to hold the registers in their inactive state in case the corresponding functional unit is not being used.
Referring to FIG. 3 , issue slot UC 0 is the only issue slot that is used by the second instruction set, used in an interrupt service routine. In order to guarantee a fast interrupt response, it is crucial to minimize the amount of state that has to be saved during interrupt handling. This can be achieved by positioning the holdable registers at common inputs of the functional units FU 0 , FU 1 and FU 2 . Therefore, holdable registers 101 , 103 and 105 are put directly at the input of the issue slot UC 0 instead of at the data inputs of each functional unit FU 0 , FU 1 and FU 2 in issue slot UC 0 . Furthermore, a holdable register 117 is put at the output of the decoder DEC for passing information of the type of operation OPT that has to be performed, instead of at the input of each functional unit FU 0 , FU 1 and FU 2 in issue slot UC 0 . At the result file index input and register index input terminals of the time shape controller TSC holdable registers 113 and 115 are positioned as well, instead of at their outputs, saving one holdable register. The positioning of the holdable registers 107 , 109 and 111 at the input of each functional unit FU 0 , FU 1 and FU 2 remains unchanged, since these functional unit inputs are not coupled to a common output of the decoder DEC.
An advantage of the positioning of the holdable registers in issue slot UC 0 , is that the amount of state that has to be saved during an interrupt is strongly reduced, when compared to the amount of state present due to the holdable registers in the issue slots UC 1 , UC 2 and UC 3 . The use of one functional unit FU 0 , FU 1 and FU 2 in the issue slot UC 0 , results in changing inputs at the other functional units of issue slot UC 0 and therefore causes unnecessary power dissipation in this issue slot. In case the entire issue slot is not being used, the holdable registers 101 - 111 and 117 will prevent power consumption by the functional units FU 0 , FU 1 and FU 2 of issue slot UC 0 .
For the issue slots UC 0 , UC 1 , UC 2 and UC 3 , the location of the holdable registers results in a well balanced consideration between increasing performance, decreasing power consumption and reducing state overhead. Many interrupts require very simple interrupt service routines and therefore only require a compact second instruction set that uses a limited second set of issue slots. In a large subset of the issue slots the holdable registers can be positioned as indicated in FIG. 2 to optimally reduce the power consumption, resulting in a significant overall reduction of the power consumption. The amount of state that has to be saved during interrupt handling is strongly reduced by positioning the holdable registers in the issue slots, used by the second instruction set, as indicated in FIG. 3 . Furthermore, the holdable registers added to the issue slots UC 0 , UC 1 , UC 2 and UC 3 form an additional pipeline stage in the architecture, allowing the processor to run at a higher clock frequency. Referring again to FIG. 1 , the holdable registers positioned in issue slots UC 0 , UC 1 , UC 2 and UC 3 divide the existing data path into two parts, decreasing the time needed to execute one part of the data path and allowing to increase the clock frequency of the processor.
A superscalar processor also comprises multiple issue slots that can perform multiple operations in parallel, as in case of a VLIW processor. The principles of the embodiments for a VLIW processor, described in this section, therefore also apply for a superscalar processor. In general, a VLIW processor may have more issue slots when compared to a superscalar processor. The hardware of a VLIW processor is less complicated when compared to a superscalar processor, which results in a better scalable architecture. The number of issue slots and the number of functional units in each issue slot, among other things, will determine the relative decrease in power consumption due to the present invention.
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually dependant claims does not indicate that a combination of these measures cannot be used to advantage.
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A multi-issue processor includes a register file and a plurality of issue slots, each one of the plurality of issue slots having a plurality of functional units and a plurality of holdable registers. The plurality of issue slots include a first set of issue slots and a second set of issue slots, and the register file is accessible by the plurality of issue slots. A location of at least a part of the plurality of holdable registers in the first set of issue slots is different from a location of at least a corresponding part of the plurality of holdable registers in the second set of issue slots.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to DNA size standards, and in particular, to a method of preparing a DNA size standard comprising a mixture of DNA fragments formed from a varying number of copies of a nucleotide motif sequence.
[0003] 2. Background of the Invention
[0004] DNA size standards are used in genetic studies and forensic applications to determine the relative sizes of nucleic acid fragments in a sample. Typically, commercially available DNA standards include DNA fragments of varying lengths (i.e., number of nucleotide bases). For example, a DNA standard may include fragments that differ by ten nucleotides from 70 to 100 nucleotides (e.g., 70, 80, etc.) and then differ by 20 nucleotides up to 400 nucleotides (e.g., 120, 140, etc).
[0005] The DNA size standards typically migrate at a rate corresponding to their size when electrophoresed through a gel matrix. However, secondary structure (i.e. the structure resulting from folding and/or bonding of the nucleotides with each other in a DNA fragment) of the respective DNA fragments will affect the rate at which the fragments migrate. If the DNA size standards fragments include secondary structure, these fragments will migrate aberrantly through an electrophoretic gel.
[0006] One disadvantage of currently available commercial DNA size standards is that the DNA size standards do not provide a narrow enough size difference between the DNA fragments to be fully useful in population genetic studies. In population genetic studies, the sizes (i.e., lengths) of different alleles are compared with one another. The size between alleles may differ by as few as one or two nucleotides. In order to properly compare alleles, an accurate relative allele size must be determined. Therefore, it is advantageous to use a DNA size standard with a narrow size difference between fragments. However, as indicated above, typical DNA size standards comprise DNA fragments differing by between 10 to 20 nucleotides in length. Consequently, these DNA size fragments fail to provide the accuracy necessary to size and compare nucleic acid samples (e.g., alleles) which may vary from each other by as few as one or two nucleotides.
[0007] A second disadvantage with commercially available size DNA standards is that several fragments typically migrate aberrantly. The aberrant migration of various fragments hampers accurate sizing of nucleic acid samples. One possible explanation for the aberrant migration of the DNA fragments is that the aberration may be due to secondary structure of the respective DNA fragments.
BRIEF SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, a method is provided for preparing DNA sizing standards which produces a mixture of DNA fragments of varying lengths and being formed of a varying number of copies of a nucleotide motif sequence. The motif sequence may be of any sequence and length, but typically the motif sequence is two to six nucleotides in length and includes one unique nucleotide. For example, the motif sequences may include CA, GTA, AACT, or AATA.
[0009] The fragments are synthesized from a dideoxy sequencing reaction using a DNA template which comprises multiple copies of the nucleotide motif sequence. The dideoxy sequencing reaction includes one dideoxy nucleotide terminator. The result of the dideoxy sequencing reaction is a DNA size standard formed of a mixture of DNA fragments of a varying number of copies of the nucleotide motif sequence.
[0010] The mixture of DNA fragments provide a nucleotide ladder with the size difference between bands being equal to that of the motif sequence length. For example, if the nucleotide motif sequence is two nucleotides long, a two nucleotide ladder will be formed. However, if the nucleotide motif sequence is three nucleotides in length, a three nucleotide ladder will be synthesized.
[0011] According to one aspect of the present invention, a method of producing a DNA size standard comprises providing a DNA template having multiple copies of a nucleotide motif sequence. A dideoxy sequencing reaction is prepared using the DNA template and one dideoxy nucleotide terminator. In one embodiment, the dideoxy nucleotide is selected from the group consisting of dideoxy ATP, dideoxy GTP, dideoxy CTP and dideoxy TTP.
[0012] According to another aspect of the invention, a DNA size standard comprises a mixture of DNA fragments in which each DNA fragment is formed of a primer, 5′ sequence and a respective number of copies of a nucleotide motif. In one embodiment, the DNA fragments vary in length from a next shorter DNA fragment or a next longer DNA fragment by one copy of the motif.
[0013] An advantage of the present invention is a DNA size standard comprising fragments which differ in length equal to the length of the motif sequence. For example, if the motif sequence is two nucleotides long, the DNA fragments will differ by two nucleotides.
[0014] An additional advantage of the present invention is a DNA size standard which provides for a more accurate measurement of DNA samples. The size of the motif sequence can be selected to produce DNA fragments that differ in length by as little as one or two nucleotide bases. A DNA standard with fragments that differ by a small number of bases, (e.g., one or two nucleotides), results is a higher resolution (i.e. more precise) measuring of the size of a DNA sample, as compared with a DNA standard having a larger difference between DNA fragments. The enhanced resolution is due to more DNA fragments within a given DNA size range from which to measure a DNA sample.
[0015] For example, if the DNA size range is between 70 to 80 nucleotide bases and the motif sequence chosen is two nucleotides long, the DNA size standard will include DNA fragments within the 70 to 80 nucleotide range of 70, 72, 74, 76, 78, and 80 nucleotide bases. A DNA size standard having fragments every two bases provides higher resolution and more accurate DNA sample measurement than a DNA size standard having fragments with larger difference, e.g., 10 to 20 bases.
[0016] An additional advantage of the present invention is DNA size standard fragments which lack secondary structure. Motifs may be selected which will not result in secondary structure. As a result, when these DNA fragments are run in an electrophoretic gel, the DNA fragments will migrate at a rate inversely proportional to their respective sizes. Consequently, the DNA size standard of the present invention provides accurate and consistent sizing of DNA samples that can be used to compare sizes of various DNA samples across gels and across platforms.
[0017] An object of the present invention is to use a DNA template formed of multiple copies of a nucleotide motif to synthesize a DNA size standard.
[0018] An additional object of the present invention is to use microsatellite loci as DNA templates to synthesize DNA size standards.
[0019] Another object of the present invention is to provide a DNA size standard formed of DNA fragments which lack secondary structure.
[0020] Yet another object of the present invention is to provide a DNA size standard of fragments that differ in length by one copy of the motif sequence.
BRIEF DESCRIPTION OF THE DRAWING
[0021] [0021]FIG. 1 illustratively depicts a dideoxy sequencing reaction according to the present invention;
[0022] [0022]FIG. 2 illustratively depicts a DNA size standard formed of DNA fragments run on an electrophoresis gel according to the present invention; and
[0023] [0023]FIG. 3 illustratively depicts another DNA size standard formed of DNA fragments run on an electrophoresis gel according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Referring now to FIG. 1, a double standard DNA sequence, denoted 10 , is show which comprises a microsatellite locus 12 . DNA sequence 10 is a basic sequence used for illustrative purposes and is used to simplify the explanation of the present invention.
[0025] Microsatellite locus 12 is composed of five copies of CA nucleotide motif sequence 14 . Unique DNA sequences (i.e. non-motif, repeating sequences) flank both the 5′ and 3′ ends of the microsatellite locus 12 . In the example illustrated, DNA sequence TCGAGGGTATCATGTT flanks the 5′ end and DNA sequence GTTAGGG flanks the 3′ end of microsatellite locus 12 .
[0026] While microsatellite locus 12 includes only five copies of a two nucleotide motif sequence, the microsatellite locus may include hundreds of copies of a 2 to 6 nucleotide motif, and it is preferable that the microsatellite locus have between 20 and 150 copies of a motif having between 2 and 6 nucleotides.
[0027] In general, DNA is composed of two antiparallel complementary strands. During DNA synthesis primed by primer 9 in this example, the upper strand is displaced and the lower strand is used as template with the complement (C pairs with G; A with T) of each base of the lower strand being sequentially added thereby synthesizing a new upper strand in the 5′ to 3′ direction. A dideoxy DNA sequencing reaction is prepared using DNA template 10 . The sequencing reaction includes a primer, and the four deoxynucleotide triphosphates, dATP, dCTP, dGTP, and dTTP. In addition, the sequencing reaction includes dideoxy ATP (ddATP). The primer is labeled with a fluorescent tag, but could also be labeled by other means (e.g., radioactive tag, IR tag, etc.). The sequencing reaction is allowed to proceed (as indicated by arrow 16 ) to synthesize a two nucleotide ladder DNA size standard denoted 18 .
[0028] During the sequencing reaction, DNA template 10 will be primed with primer 9 and a nascent DNA fragment will be synthesized, one nucleotide at a time, using the four deoxy nucleotides, dATP, dCTP, dGTP, and dTTP, and the dideoxy nucleotide, ddATP present in the sequencing reaction. Appropriate nucleotides will be added, one base at a time, to the last nucleotide (3′end) of a nascent DNA sequence and proceeds in the direction indicated by arrow 8 .
[0029] When the appropriate nucleotide to be inserted is A (adenine), either dATP or ddATP will be added. More correctly, either dATP or ddATP will enter the synthesis reaction resulting in either dAMP (deoxyadenine monophosphate) or ddAMP being introduced into the elongating DNA chain. If dAMP is inserted, the chain can be further elongated by adding another nucleotide (e.g., cytosine). However, if a ddAMP is inserted, no additional nucleotides may be added. Therefore, elongation of the nascent DNA fragment terminates upon addition of ddATP.
[0030] The sequencing reaction proceeds on multiple copies of the DNA template, microsatellite locus 12 . Randomly, a dideoxy ATP will be added to nascent DNA fragments at one of the A positions, thereby terminating the respective nascent fragment. Consequently, the nascent DNA fragments will have different lengths depending on the A position at which the dideoxy ATP was added.
[0031] At the conclusion of the DNA sequencing reaction, DNA size standard 18 is produced. DNA size standard 18 comprises five DNA fragments 20 , 22 , 24 , 26 and 28 formed of the primer, 5′ flanking sequences and two to five copies of motif sequence 14 , respectively. As shown, DNA fragments 20 , 22 , 24 , 26 and 28 are 18, 20, 22, 24, and 26 nucleotides in length, respectively.
[0032] When a dideoxy ATP is randomly inserted at the first A of microsatellite locus 12 , DNA fragment 20 is produced. Further, when a dideoxy ATP is randomly inserted at the second A, DNA fragment 22 is produced; similarly, at the third A, DNA fragment 24 is produced; at the fourth A, DNA fragment 26 is produced; and at the fifth A, DNA fragment 28 is produced.
[0033] In accordance with an important aspect of the invention, the microsatellite locus 12 with nucleotide motif sequence 14 is selected such that DNA fragments 20 , 22 , 24 , 26 , 28 do not form a respective secondary structure. The presence or lack of secondary structure can be determined empirically by analyzing the DNA sequence data using any of a number of techniques and computer software programs. For example, the Shareware program FOLD is one such program which analyzes a nucleotide sequence for secondary structure. Although FOLD was developed to calculate secondary structure of RNA molecules, it is used here as a method to approximate the relative amount of secondary structure in DNA. The FOLD program assigns energy values to the most stable intra-molecular species that can potentially form based upon the primary nucleotide sequence. Values, calculated at 50 degrees C., of −15 and smaller would indicate the presence of a secondary structure whereas values of −8.5 and larger would indicate the lack of a secondary structure. A further discussion on the FOLD program is provided by M. Zuker, “On Finding All Suboptimal Foldings of an RNA Molecule,” Science, 244, 48-52, (1989); J. A. Jaeger, D. H. Turner and M. Zuker, “Improved Predictions of Secondary Structures for RNA. Proc. Natl. Acad. Sci.,” USA, Biochemistry, 86, 7706-7710, (1989); and J. A. Jaeger, D. H. Turner and M. Zuker, “Predicting Optimal and Suboptimal Secondary Structure for RNA in “Molecular Evolution: Computer Analysis of Protein and Nucleic Acid Sequences,” R. F. Doolittle ed. Methods in Enzymology, 183, 281-306 (1989), all herein incorporated by reference.
[0034] The presence of secondary structure affects how a DNA fragment will migrate through an electrophoresis gel. By selecting a DNA template which lacks secondary structure, an accurate and consistent size standard can be provided which can be used to compare sizes and fragments across gels.
[0035] Referring now to FIG. 2, DNA size standard 18 is run through electrophoresis gel 29 . The DNA fragments migrate according to their respective sizes. The DNA fragments 20 , 22 , 24 , 26 and 28 migrate at uniform but different rates through electrophoresis gel 29 . The rate of migration is inversely proportional to the fragment length since the fragments do not contain secondary structure. The distance DNA fragments migrate is inversely proportional to the length of the respective DNA fragments 20 , 22 , 24 , 26 , and 28 with shorter fragments migrating farther than longer fragments.
[0036] The present method may be modified in order to provide a DNA size standard with an alternate size difference between DNA fragments. For example, a three nucleotide motif sequence may be used to provide a three nucleotide DNA ladder. As such, the nucleotide DNA would have a three nucleotide difference between DNA fragments.
[0037] Further, the present method may be modified by choosing a microsatellite locus having more copies of the motif sequence. The resulting ladder will produce larger DNA fragments, which differ by the number of copies of the motif sequence size, up to the length of the microsatellite locus selected.
EXAMPLE
[0038] In one example, chum salmon microsatellite clone C97 is used as a DNA template. C97 contains a microsatellite locus region having 60 copies of two nucleotide motif sequence CA.
[0039] A DNA size standard was produced using SequiTherm EXCEL II DNA sequencing kit (Epicentre, Madison, Wis.), using clone C97 DNA as the template, and a ddA (dideoxy ATP) terminator. The DNA template was primed using KS primer (Stratagene, San Diego, Calif.) that was labeled with a florescent tag (HEX).
[0040] Referring now to FIG. 3, a two nucleotide ladder 32 , produced by the sequencing reaction on C97, is shown which was run on gel 39 . Two nucleotide ladder 32 provides a functional DNA size standard between a 71 nucleotide DNA fragment 34 and a 191 nucleotide DNA fragment 36 , having fragments differing in length by two nucleotides.
[0041] DNA fragments having sizes larger than 191 nucleotides did not result in adequate visualization on gel 39 . Although the spacing of DNA fragments smaller than 71 nucleotides is not 2 nucleotides, they can be used for sizing smaller fragments. However, other ladders that span smaller and larger size ranges can be synthesized to size smaller or larger fragments. Consequently, ladder 32 may be used to size DNA samples between 71 and 191 nucleotides long.
[0042] Although the invention has been described above in relation to preferred embodiments thereof, it will be understood by those skilled in the art that variations and modifications can be effected in these preferred embodiments without departing from the scope and spirit of the invention.
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A method for producing DNA size standards includes using a DNA template having multiple copies of a nucleotide motif sequence. A dideoxy sequencing reaction is prepared which uses the DNA template. In the sequencing reaction, one dideoxy nucleotide terminator is included. The synthesized DNA size standard comprises a mixture of DNA fragments. Each DNA fragment is formed of a respective number of copies of the nucleotide motif. In one further embodiment, each DNA fragment varies in length, from a next shorter or a next longer DNA fragment, by the length of one nucleotide motif sequence.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to composite polymers containing nanometer-sized metal particles and manufacturing method thereof, and more particularly, to composite polymers containing nanometer-sized metal particles and manufacturing method thereof, which nanometer-sized metal particles are uniformly dispersed into the polymers, thereby allowing the use thereof as optical, electrical and magnetic materials.
[0003] 2. Description of the Related Art
[0004] In general, nanometer-sized metal or semiconductor particles, i.e., nano-particles, have a nonlinear optical effect. Therefore, composite polymers having the nano-particles dispersed on polymers or glass matrices have attracted people's attentions in optical materials. Moreover, the nano-particles having a magnetic property are applicable in various ways, for example, a use for an electromagnetism storage medium.
[0005] In manufacturing the composite polymers, the nano-particles, which are manufactured by the process of vacuum deposit, sputtering, CVD or sol-gel process, mixed with polymer melt in a high temperature or polymer solution dissolved in a proper solvent and dispersed well in a polymer matrix.
[0006] A conventional composite polymers obtained by a conventional method by dispersing nano-particles into the polymer matrix, cannot show satisfactory composite material characteristics because a state of the nano-particles is changed due to a high surface energy of the nano-particles and the nano-particles may easily form agglomeration when dispersed on a matrix, i.e., cause a light scattering in using for nonlinear optics.
[0007] Nanometer sized particles, which have a finite size effect, have characteristics different from a bulk state. Various attempts have been tried to manufacture metal particles of nanometer size through various physical and chemical processes that has been known to be reliable, in a monodispersion, and have valence of zero, for manufacturing such fine particles.
[0008] Such attempts include the steps of sputtering, metal deposition, abrasion, metallic salt reduction, and neutral organometallic precursor decomposition.
[0009] Transition metal particles, such as gold (Au), silver (Ag), palladium (Pd) and Platinum (Pt), manufactured as conventional methods are in the form of aggregated powder state or are sensitive to air and tend to be agglomerated irreversibly.
[0010] Such an air sensitivity raises a problem in connection with stability when the metal particles present in a large amount. Moreover, the air sensitivity has another problem that the metal particles are collapsed due to oxidation if the final products are not sealed under a high-priced air blocking state during the manufacturing process.
[0011] The irreversible agglomeration of the particles needs a separation process which causes a problem in controlling the particle size distribution in a desired range and prevents formation of a soft and thin film, which is essential for a magnetic recording application field. The agglomeration reduces a surface area, which is chemically active for catalytic action, and largely restricts solubility, which is essential for biochemical label, separation and chemical transmission application field.
[0012] With the reasons, to exactly adjust a particle size or to manufacture nano-particles having a mono-dispersion phase is an important object in a technical application field of the nano-materials. Therefore, the nano-particles have been manufactured by physical methods such as mechanical abrasion, metal deposition condensation, laser ablation and electrical spark corrosion, and by chemical methods such as reduction of metallic salt in a solution state, pyrolysis of metal carbonyl precursor and electrochemical plating of metals.
[0013] Since several physical or chemical methods cause incompatibility and a permanent agglomeration when metal particles accumulated from a vapor state under appropriate stabilizer transfer fluid or transfer fluid containing the appropriate stabilizer. It is impossible to improve the general process of direct dispersion of nanoparticles into the matrices.
[0014] Furthermore, even though the metal particles are manufactured in a mono-dispersion phase state, the particles are agglomerated and not dispersed well due to the heat or pressure generated during the process of dispersing the metal particles in the polymer matrix, the metal particles are not compatible with the polymer matrix and defects are generated on the interface.
SUMMARY OF THE INVENTION
[0015] It is, therefore, an object of the present invention to provide composite polymers containing nanometer-sized metal particles and manufacturing method thereof, which can keep nanometer-sized metal particles in a well dispersion state in a matrix without a permanent agglomeration.
[0016] It is another object of the present invention to provide a simple method, which is capable of easily manufacturing composite polymers in such a manner that the manufacture of nanometer-sized particles and the separate process for composition are performed in-situ.
[0017] It is a further object of the present invention to provide a method, which is capable of overcoming a limitation of the amount of metal particles in conventional composite polymers and adjusting the amount of the metal particles in the matrix in a molecule level.
[0018] To achieve the object, the present invention provides a method for manufacturing composite polymers containing nanometer-sized metal particles, the method including the steps of: dispersing at least one metal precursor into a matrix made of polymers in a molecule level; and irradiating rays of light on the matrix containing the metal precursors dispersed in the molecular level and reducing and fixing the metal precursors into metals inside of matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
[0020] [0020]FIG. 1 shows a transmission electron micrograph (TEM) picture of composite polymers of nano-particles formed in a polymer matrix obtained in a thirteenth preferred embodiment of the present invention;
[0021] [0021]FIG. 2 shows a spectrum of plasmon peaks detected by nanometer-sized Ag particles in the polymer matrix containing nanometer-sized Ag particles manufactured in first to fourth preferred embodiments of the present invention;
[0022] [0022]FIG. 3 shows a spectrum of plasmon peaks detected by nanometer-sized Ag particles in the polymer matrix containing nanometer-sized Ag particles manufactured in fifth and sixth preferred embodiments of the present invention; and
[0023] [0023]FIG. 4 shows a spectrum of plasmon peaks detected by nanometer-sized Au particles in the polymer matrix containing nanometer-sized Au particles manufactured in a twenty-second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings.
[0025] Metal precursors selected from a group consisting of Au, Pt, Pd, Cu, Ag, Co, Fe, Ni, Mn, Sm, Nd, Pr, Gd, Ti, Zr, Si and In elements, intermetallic compound of the elements, binary alloy of the elements, ternary alloy of the elements, and Fe oxide, besides barium ferrite and strontium ferrite, additionally containing at least one of the elements are dispersed well in a molecular level by an attractive force to the matrix by using a solvent or as a melt and kept in an in-situ state.
[0026] The matrix used in the present invention contains polymers having functional groups capable of Π→Π* transition or Π→Π* transition by electron excitation or inorganic materials compatible with the polymers by receiving light having visible (40˜70 kcal/mole) and ultraviolet (70˜300 kcal/mole) range of energies.
[0027] For more detailed description, electrons on double or triple bond or conjugate bonds electrons having the double and triple bonds together absorb a wavelength energy of 200˜750 nm range, the Π→Π* transition is caused or the functional groups having electron lone-pair such as oxygen of carbonyl group cause the Π→Π* transition.
[0028] If the light is irradiated and the electron transition is caused, the conformation is changed or the bonding is broken. In the following table 1, functional groups and wave length, λ max leading to the transition are presented, but the present invention is not restricted to the following table.
TABLE 1 Compound λ max Compound λ max CH 2 ═CHCH═CH 2 217 CH 3 —CO—CH 3 (n → π*) 270 CH 2 ═CHCHO 218 CH 3 —CO—CH 3 (π→ π*) 187 CH 3 CH═CHCHO 220 CH 3 COCH═CH 2 (n → π*) 324 CH 3 CH═CHCH═CHCHO 270 CH 3 COCH═CH 2 (π→ π*) 219 CH 3 (CH═CH) 3 CHO 312 CH 2 ═CHCOCH 3 219 CH 3 (CH═CH) 4 CHO 343 CH 3 CH═CHCOCH 3 224 CH 3 (CH═CH) 5 CHO 370 (CH 3 ) 2 C═CHCOCH 3 235 CH 3 (CH═CH) 6 CHO 393 CH 2 ═C(CH 3 )CH═CH 2 220 CH 3 (CH═CH) 7 CHO 415 CH 3 CH═CHCH═CH 2 223.5 CH 2 ═C(CH 3 )C(CH 3 )═CH 2 226 CH 3 CH═CHCH═CHCH 3 227 Ph-CH═CH-Ph(trans) 295 Ph-CH═CH-Ph(cis) 280 Styrene 244, 282 Sulfide ˜210, 230 C═O in carboylic 200˜210 Acid chloride 235 acid Nitrile 160 Alkyl bromide, 250˜260 iodides
[0029] If the electrons are excited by the light and broken in the bonding, radical is generated. The radical gives electron to metal ion, and thereby the metal ion is reduced to metal.
[0030] The matrix used in the present invention is selected from a group consisting of polypropylene, biaxial orientation polypropylene, polyethylene, polystyrene, polymethyl methacrylate, polyamide 6, polyethylene terephthalate, poly-4-methyl-pentene, polybutylene, polypentadiene, polyvinyl chloride, polycarbonate, polybutylene terephthalate, polydimethylsiloxane, polysulfone, polyimide, cellulose, cellulose acetate, ethylene-propylene copolymer, ethylene-butene-propylene terpolymer, polyoxazoline, polyethylene oxide, polypropylene oxide, polyvinylpyrrolidone, or derivative of them.
[0031] Moreover, the polymers used for matrix materials may have one or more functional groups forming radical by absorbing the light in the range of ultraviolet-visible (UV-VIS) ray area and exciting the electrons to break the bonding. However, it is most preferable to have carbonyl group and group having electron lone-pair atoms.
[0032] The polymer has a molecular structure, such as linear, nonlinear, dendrimer or hyperbranch polymer structures. Alternatively, blend polymer mixing two or more type polymers having different structures mentioned above may be used.
[0033] In the present invention, the amount of the metal precursors is indicated as a molar ratio of a basic functional group unit of the used polymer matrix, and has the molar ratio of metal to matrix functional group in the range from 1:100 to 2:1. If the molar ratio is less than 1:100, the properties of the metal-polymer are not desirable because the amount of metal particles contained in the polymer matrix is very little. If the molar ratio is more than 2:1, the matrix cannot form a free-standing film because the amount of the metal particles is very much.
[0034] The structure of the composite material shown in FIG. 1 is of a film type, in which Ag particles are well dispersed in the polymer matrix, but suitable matrices may be selected according to the usages.
[0035] The matrix in FIG. 1 is polyvinyl pyrrolidone. AgBF 4 is used as metal precursor, and nano-particles in the range of several to several tens of nanometers are formed.
[0036] The composite material shown in FIG. 1 can be manufactured as follows.
[0037] First, the matrix is dissolved in a solvent, and metallic salt is dissolved or dispersed in the solution to an appropriate ratio.
[0038] The solution, in which the matrix and the metallic salt are dispersed well, is cast on a supporter (in this case, a glass plate) to form a film. After evaporating the solvent, the free-standing film is obtained, ultraviolet ray is irradiated on the obtained film and the metallic precursor is reduced into metal.
[0039] The obtained composite film having uniform sized metal paticles which are well dispersed in molecular level can be obtained because the polymer matrix prevents the metallic agglomerating.
[0040] A conventional composite material in which nanometer-sized metals are dispersed is obtained by a method of dispersing metal particles in the matrix after obtaining the nanometer-sized metal particles by a separate process.
[0041] In the conventional method, even though the nano-particles are obtained in a uniform distribution, the particles are not well dispersed and agglomerated together because of an attractive force between the particles, incompatibility to the matrix, or by pressure or heat produced during the process.
[0042] However, the composite material according to the present invention has nonlinear optical characteristics by the presence of the metallic nano-particles and can be used as elements for control the phase, strength and frequency of light. Moreover, sensitivity of optical material is increased because the composite material has a high metallic nano-particle content. It has been well known as the characteristics of metallic nano-hybrid polymers without having agglomeration.
[0043] With the advantage of forming films having different amount of the nano-particles may be manufactured, if a thickness of a film containing the nano-particles of an appropriate amount and a distance between adjacent metallic nano-particles are adjusted suitably, then the film can be used as a diffraction grating to radiations having wave range of X-rays from far ultraviolet rays. Furthermore, the film may be used as a data storage media using a magnetic property of the metal.
[0044] Additionally, the film may be used for various application fields using the nonlinear optical effects of the metallic nano-particles and the characteristics of the matrix (for example, electric conductivity), by regulating the properties of the matrix. If the metallic nano-particles have a catalytic activity, the composite polymers may be used as a catalyst, in which catalytic elements are supported by a heat-resistant matrix.
[0045] Hereinafter, the present invention will be described in the following embodiments in detail.
[0046] Embodiments 1 to 4
[0047] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution.
[0048] AgCF 3 SO 3 was added to the resulting solution to have a molar ratio of carbonyl as the unit of POZ to silver trifluoro methanesulfonate being 1:1, and dispersed in a molecule level. The manufactured polymer-silver trifluoro methanesulfonate solution was cast on the glass plate in a thickness of 200 μm. The solvent was evaporated to produce a polymer-silver trifluoro methanesulfonate film.
[0049] An ultraviolet lamp irradiated ultraviolet rays on the film in the air. The following table 2 shows values of electric surface conductivity, and plasmon peaks detected due to the silver metal particles and measured using ultraviolet-visible (UV-VIS) spectrometer to each sample.
TABLE 2 Ultraviolet irradiation Surface ion time (hr) conductivity (Ω/cm) Comparative 0 0 example 1 Embodiment 2 0.007 1 Embodiment 3 0.007 2 Embodiment 5 0.008 3 Embodiment 7 0.01 4
[0050] Embodiments 5 and 6
[0051] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgCF 3 SO 3 was added into the resulting solution to have a molar ratio of carbonyl as the unit of POZ to silver trifluoro methanesulfonate being 1:1, and dispersed in a molecular level.
[0052] The manufactured polymer-silver trifluoro methanesulfonate solution was cast on the glass plate in the thickness of 200 μm. The solvent was evaporated to produce a polymer-silver trifluoro methanesulfonate film.
[0053] An ultraviolet lamp irradiated ultraviolet rays on the manufactured film under nitrogen. The following table 3 shows values of electric surface conductivity to each sample, and plasmon peaks detected due to the silver metal particles and measured using ultraviolet-visible (UV-VIS) ray spectrometer.
TABLE 3 Ultraviolet irradiation Surface ion time (hr) conductivity (Ω/cm) Comparative 0 0 example 1 Embodiment 5 3 0.006 Embodiment 6 7 0.008
[0054] Embodiment 7
[0055] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgCF 3 SO 3 was added into the resulting solution to have a molar ratio of carbonyl to silver trifluoro methanesulfonate being 10:1, and dispersed in a molecular level.
[0056] The manufactured polymer-silver trifluoro methanesulfonate solution was cast on the glass plate in the thickness of 200 μm. The solvent was evaporated to produce a polymer-silver trifluoro methanesulfonate film. An ultraviolet lamp irradiated ultraviolet rays on the manufactured polymer-silver film in the air, and then a composite thin film was manufactured.
[0057] Embodiment 8
[0058] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgCF 3 SO 3 was added into the resulting solution to have a molar ratio of carbonyl as the unit of POZ to silver trifluoro methanesulfonate being 4:1, and dispersed in a molecule level.
[0059] In the same way as the embodiment 1, the composite thin film was manufactured using the polymer-trifluoro methanesulfonate solution. The size of silvers manufactured in the polymer matrix was 10 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0060] Embodiment 9
[0061] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgBF 4 was added into the resulting solution to have a molar ratio of carbonyl to silver tetraflouroborate being 1:1, and dispersed in a molecular level.
[0062] In the same way as the embodiment 1, the composite thin film was manufactured using the polymer-silver tetraflouroborate solution. The size of silvers manufactured in the polymer matrix was 9 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0063] Embodiment 10
[0064] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgNO 3 was added into the resulting solution to have a molar ratio of carbonyl to silver nitrate being 1:1, and dispersed in a molecular level.
[0065] In the same way as the embodiment 1, the composite thin film was manufactured using the polymer-silver nitrate solution. The size of silvers manufactured in the polymer matrix was 10 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0066] Embodiment 11
[0067] Poly(2-ethyl-2-oxazoline) (POZ; a molecular weight is 5×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgClO 4 was added to the resulting solution to have a molar ratio of carbonyl to silver perchlorate being 1:1, and dispersed in a molecular level.
[0068] In the same way as the embodiment 1, the composite thin film was manufactured using the polymer-silver perchlorate solution. The size of silvers manufactured in the polymer matrix was 9.5 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0069] Embodiment 12
[0070] Poly vinyl pyrrolidone (PVP; a molecular weight is 1×10 6 , manufactured by the Polyscience company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgCF 3 SO 3 was added to the resulting solution to have a molar ratio of carbonyl to silver trifluoro methanesulfonate being 1:1, and dispersed in a molecule level.
[0071] In the same way as the embodiment 1, the composite thin film was manufactured on the glass plate using the polymer-silver trifluoro methanesulfonate solution.
[0072] Embodiment 13
[0073] Poly vinyl pyrrolidone (PVP; a molecular weight is 1×10 6 , manufactured by the Polyscience company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgBF 4 was added to the resulting solution to have a molar ratio of carbonyl to silver tetraflouroborate being 1:1, and dispersed in a molecular level.
[0074] In the same way as the embodiment 1, the composite thin film was manufactured on the glass plate using the polymer-silver tetraflouroborate solution. The size of silvers manufactured in the polymer matrix was 9.5 nm on the average, and the silver nanoparticles were dispersed well without agglomeration. As the result, the structure of composite thin film is shown in FIG. 1.
[0075] Embodiments 14 to 17
[0076] Poly vinyl pyrrolidone (PVP; a molecular weight is 1×10 6 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgBF 4 was added to the resulting solution to have a molar ratio of carbonyl to silver tetraflouroborate being 2:1, and dispersed in a molecular level.
[0077] The manufactured polymer-silver tetraflouroborate solution was cast on the glass plate and ultraviolet ray was irradiated by an hour in the same way as the embodiment 1, to manufacture composite thin film. The size of silver nanoparticles manufactured in the polymer matrix was 9.5 nm on the average, and the silvers were dispersed well without agglomeration. The following table 4 shows values of electric surface conductivity to each sample.
TABLE 4 Ultraviolet irradiation Surface ion time (hr) conductivity (Ω/cm) Comparative 0 0 example 2 Embodiment 14 0.17 9 × 10 −3 Embodiment 15 0.5 5 × 10 −4 Embodiment 16 1.75 2.37 × 10 −3 Embodiment 17 4 3.37 × 10 −3
[0078] Embodiment 18
[0079] Poly vinyl pyrrolidone (PVP; a molecular weight is 1×10 5 , manufactured by the Aldrich company) was dissolved in water of 20% by weight to manufacture a polymer solution. AgBF 4 was added to the resulting solution to have a molar ratio of carbonyl to silver tetraflouroborate being 4:1, and dispersed in a molecular level.
[0080] In the same way as the embodiment 1, the composite thin film was manufactured on the glass plate using the polymer-silver tetraflouroborate solution. The size of silver nanoparticles manufactured in the polymer matrix was 10 nm on the average, and the silvers were dispersed well without agglomeration.
[0081] Embodiment 19
[0082] Poly ethylene oxide (a molecular weight is 1×10 6 , manufactured by the Aldrich company) was dissolved in water of 2% by weight to manufacture a polymer solution. AgBF 4 was added to the resulting solution to have a molar ratio of oxygen as the unit of the polymer to silver tetraflouroborate being 1:1, and dispersed in a molecular level.
[0083] In the same way as the embodiment 1, the composite thin film was manufactured on the glass plate using the polymer-silver tetraflouroborate solution. The size of silver nanoparticles manufactured in the polymer matrix was 10 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0084] Embodiment 20
[0085] Poly ethylene oxide (a molecular weight is 1×10 6 , manufactured by the Aldrich company) was dissolved in water of 2% by weight to manufacture a polymer solution. AgBF 4 was added to the resulting solution to have a molar ratio of carbonyl to silver tetraflouroborate being 4:1, and dispersed in a molecular level.
[0086] In the same way as the embodiment 1, the composite thin film was manufactured on the glass plate using the polymer-silver tetraflouroborate solution. The size of silver nanoparticles manufactured in the polymer matrix was 12 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0087] Embodiment 21
[0088] Poly ethylene oxide (a molecular weight is 1×10 6 , manufactured by the Aldrich company) was dissolved in water of 2% by weight to manufacture a polymer solution. AgCF 3 SO 3 was added to the resulting solution to have a molar ratio of carbonyl to silver trifluoro methanesulfonate being 1:1, and dispersed in a molecular level.
[0089] In the same way as the embodiment 1, the composite thin film was manufactured on the glass plate using the polymer-silver trifluoro methanesulfonate solution. The size of silver nanoparticles manufactured in the polymer matrix was 10 nm on the average, and the silver nanoparticles were dispersed well without agglomeration.
[0090] Embodiment 22
[0091] HAuCl 4 aqueous solution was made in a molar ratio of 8:1 on the basis of terminal amine group using a third generation Starburst, TM, dendrimer (Polyamidoamine; a molecular weight is 6909, manufactured by the Aldrich company). The aqueous solution was mixed with polyvinyl pyrrolidone solution of 20% by weight so that HAuCl 4 permeated into the dendrimers and mixed well with the polymers. In the same way as the embodiment 1, the film was manufactured and ultraviolet rays were irradiated, and then composite metal-polymers were manufactured.
[0092] The auric ions permeated into the dendrimers were reduced. The golds were wrapped with the dendrimers without agglomeration, and thus composite material having a uniform size distribution and good dispersion were obtained.
[0093] The size of the gold particles in the dendrimers measured through the TEM was 4 nm on the average and the golds were dispersed well without agglomeration.
[0094] Embodiment 23
[0095] HAuCl 4 was made into aqueous solution in a molar ratio of 8:1 on the basis of terminal amine group using a fourth generation Starburst, TM, dendrimer (Polyamidoamine; a molecular weight is 14279, manufactured by the Aldrich company). The aqueous solution was mixed with polyvinyl pyrrolidone solution of 20% by weight. HAuCl 4 permeated into the dendrimers and mixed well with the polymers. In the same way as the embodiment 1, the film was manufactured and ultraviolet rays were irradiated, and then composite metal-polymers were manufactured.
[0096] Auric ions permeated into the dendrimers were reduced and wrapped with the dendrimers without agglomeration among the metals, as a result of which a composite material having a uniform size distribution and good dispersion was obtained.
[0097] The size of the gold particles in the dendrimers measured through the TEM was 5 nm on the average and the golds were dispersed well without agglomeration. To indicate the formation of gold, a result that plasmon peaks of golds were measured with ultraviolet-visible (UV-VIS) ray absorption spectrum is shown in FIG. 4.
[0098] Embodiment 24
[0099] In the same way as the embodiment 1, the composite material was manufactured using HAuCl 4 as the metal precursor. The size of the gold particles in the dendrimers measured through the TEM was 10 nm on the average and the gold particles were dispersed well without agglomeration.
[0100] Embodiment 25
[0101] In the same way as the embodiment 1, the composite material was manufactured using metal salts in which HAuCl 4 and AgBF 4 were mixed in a molar ratio of 1:1 as the metal precursor.
[0102] Embodiment 26
[0103] In the same way as the embodiment 1, the composite material was manufactured by using FeCl 2 as the metal precursor.
[0104] Embodiment 27
[0105] In the same way as the embodiment 1, the composite material was manufactured using CoCl 2 as the metal precursor.
[0106] As described above, according to the present invention, the process of manufacturing metallic nano-particles and of dispersing the nano-particles into the matrix is simplified. Moreover, the problem of the conventional composite material, i.e., the formation of agglomeration between the nano-particles, can be solved in such a manner that the precursors of the metal particles are dispersed well in the matrix in the molecular level and manufactured in the final type (mainly, a film type), and the metal is reduced in-situ by the light, and thereby the size of the particles can be adjusted according to the matrix and the composite material without agglomeration can be manufactured.
[0107] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
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The present invention relates to composite polymers containing nanometer-sized metal particles and manufacturing method thereof, which can be uniformly dispersed nanometer-sized metal particles into polymers, thereby allowing the use thereof as optically, electrically and magnetically functional materials. The method for manufacturing composite polymers containing nanometer-sized metal particles includes the steps of: dispersing at least one metal precursor into a matrix made of polymers in a molecule level; and irradiating rays of light on the matrix containing the metal precursors dispersed in the molecule level and reducing the metal precursors into metals and fixing nanometer sized metal particles inside of matrix.
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RELATED APPLICATION
This application is a continuation-in-part application of my application Ser. No. 146,658, filed May 5, 1980, and entitled "Rotary Device", now abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to a rotary device or unit, and more particularly, to an improved rotary device having means facilitating an increased power shaft diameter.
Rotary expansion engines or power units of the type having a housing defining an epitrochoidal cavity, a planetating rotor element movable within such cavity and an eccentric or lobe means integrally formed with the power shaft on which the rotor rotates are well known in the art. It is also well known that the expansion force in these rotary expansion devices can be provided either by pressured expansion fluid or by internal combustion means and that certain of these expansion devices, particularly the devices utilizing pressurized expansion fluid, can also function equally well as a compression device, such as an air compressor. Thus, although the description of the present invention is directed primarily to a rotary expansion device utilizing pressurized expansion fluid, it is understood that the inventive principles apply to rotary expansion devices utilizing internal combustion means and rotary compression devices as well. In the conventional rotary device, the rotation of the rotor about the eccentric or lobe portion and the revolution of the radial center of the rotor about the center line of the power shaft are controlled by what are known in the art as phasing gears. These phasing gears include an internal ring gear formed within, and rotatable with, a portion of the rotor and an external pinion or stationary gear fixed with respect to the device housing. As a result of engagement between the ring and pinion gears, the rotor is caused to rotate about the eccentric or lobe portion during its revolution about the axis of the power shaft. The relationship between the ring and pinion gears is such as to insure continuous contact between each of the apices of the rotor element and the inner wall of the epitrochoidal cavity. These rotary engines or power units also include appropriate seals and valving means for selectively directing expansion fluid, in the case of a rotary expansion device utilizing this type of expansion force into the plurality of expansion chambers defined by the engine housing and the outer surfaces of the rotor. A typical rotary expansion unit of this type is described in Hoffmann U.S. Pat. No. 4,047,856.
Rotary devices or units have several design variables. One such variable is the number of lobes in the epitrochoidal cavity, and thus the number of apices on the rotor. A rotary device or unit of common construction is one having an epitrochoidal cavity with two opposing lobes and a planetating rotor with three apices. This is the type of unit described and illustrated in U.S. Pat. No. 4,047,856. In rotary expansion engines of this type, it is axiomatic that the ratio between the internal ring gear in the rotor and the external stationary or pinion gear fixed to the housing must be 3:2. In other words, the pitch diameter of the ring gear must be one and one half times greater than the pitch diameter of the pinion gear. Accordingly, the internal ring gear has one and one half times as many teeth as the external pinion gear. A further relationship necessary in this type of unit is that the pitch diameter of the internal ring gear must be exactly six times the rotor eccentricity, which is the distance between the axial center line of the power shaft and the axial center line of the rotor, and the pitch diameter of the pinion gear must be exactly four times this same eccentricity. Thus, the sizes of the ring gear and pinion gear for a given eccentricity are specified and thus limited. Because one end of the power shaft must pass through the center of this pinion gear, the diameter of such shaft is also necessarily limited. Clearly, it can be no greater than the pitch diameter of the pinion gear less the necessary radial material needed to support the gear teeth. In a conventional rotary unit as described above having a two lobe epitrochoidal cavity, the pitch diameter of the pinion gear is four times the eccentricity. In a rotary device characterized by an "inner envelope" shaped rotor, an epitrochoidal cavity having M lobes will have a rotor with M+1 faces or apices. In the specific case of Hoffmann U.S. Pat. No. 4,047,856, M=2, thus M+1=3. It thus follows that in the general case, the fixed pinion gear in an "inner envelope" shaped rotor will always be related to the ring gear in the ratio of M/(M+1) with respect to the tooth ratio and the pitch diameters.
The limitation of power shaft diameter resulting from the heretofore necessary relationship between the pitch diameters of the ring and pinion gears and the eccentricity leads to several disadvantages or limitations of conventional rotary units. First, the power shaft is limited to how much torque it can carry. Secondly, the power shaft is known to bend due to the radial forces imposed on the rotor, thus imposing undesirable vibrations on the mechanism. Thirdly, the bending of the power shaft as mentioned above sometimes causes the pinion gear to break and may cause wear in the pinion gear bearing of a "bell mouth" pattern. Fourthly, the conventional power shaft results in a journal bearing which may be of inadequate area to carry the load imposed by the rotor.
Because of the above limitations, there is a need in the art for a rotary expansion or compression device capable of facilitating a power shaft with an increased diameter which has heretofore been limited because of design constraints dictated by the relationships between ring and pinion gear pitch diameters and rotor eccentricity.
SUMMARY OF THE INVENTION
In a first embodiment or concept, the rotary device or unit of the present invention allows for what is known in the art as the pinion or stationary gear to be increased in diameter significantly without affecting the operability of such unit, thus removing entirely the previously accepted requirement in a rotary unit having two epitrochoidal lobes that the pitch diameter of the pinion gear be four times the rotor eccentricity. In this first embodiment, the rotary unit still contemplates a ring gear-pinion gear pitch diameter ratio of 3:2, but eliminates the necessity for the pitch diameter of the pinion gear to be four times the rotor eccentricity and thus also eliminates the necessity for the pitch diameter of the ring gear to be six times the rotor eccentricity. This is accomplished by mounting this enlarged pinion gear on its own eccentricity and appropriately planetating it about the power shaft axis. The rotor size, however, is still specified and limited by the rotor eccentricity e and the parameter R (where R/e=K which together mathematically specify the size and shape of the rotor and the epitrochoidal bore. Thus, in a system incorporating this first embodiment, the ring gear which may be fit into the limiting profile of the rotor, and thus the pinion gear, is limited in part by the permissible size of the rotor.
A second embodiment or concept of the present invention enables a still larger possible power shaft for the same rotor size or profile. In this second embodiment, the 3:2 relationship between the ring gear and pinion gear pitch diameter in a rotary power unit with two epitrochoidal lobes is no longer necessary. For example, the pinion gear in this second embodiment is increased further without any corresponding increase in the ring gear diameter. With this increase in pinion gear size relative to the ring gear, however, the effect is for the rotor to rotate slower than it should. Thus, means must be provided to speed up or compensate for this insufficient rotational speed of the rotor. This correcting rotation is accomplished by a second ring and pinion gear assembly operatively connected with the enlarged first ring and pinion gear assembly.
The ability to enlarge the pinion gear, and thus increase the power shaft diameter, as described above allows for a structure with several advantages not found in conventional rotary power units. First, the increased power shaft diameter results in significant increase in its maximum torsional strength, with increases of at least two times for K factors of 7.5 and increases of at least ten times for K factors of 11. Secondly, this ability to increase the pinion gear diameter allows for multiple rotor engines to be built for larger horse powers without having to split the ring gear as shown in U.S. Pat. No. 3,062,435, since the diameter of the shaft where it passes through the pinion gear can now be larger than adjacent portions of the main power take-off shaft. Thirdly, the larger and more rigid power shaft will not bend as much, and thus not adversely affect its main bearings such as to wear the pinion gear bearing in a "bell mouth" pattern as suggested in U.S. Pat. No. 3,881,847. Fourthly, an increase in the power shaft diameter will reduce the radial pressure on the bearings and thus increase the bearing life.
The summary of the invention as described above and the description of the preferred embodiments as described below is directed primarily to a rotary power unit having an epitrochoidal cavity with two lobes and a planetating rotor with three apices. It is contemplated, however, that the concepts of the present invention are equally applicable to epitrochoidal cavities with K number of lobes and planetating rotors with K+1 apices, in the case of "inner envelope" rotors; thus, the scope of the present invention is intended to cover these. It is also contemplated that the benefits and advantages of the present invention can be realized for rotary devices characterized as epitrochoids with "outer envelopes" in which the rotor is an epitrochoid and the housing is an outer envelope of the epitrochoid. In such a configuration most elements are reversed insofar as the epitrochoidal rotor carries a pinion gear, not a ring gear, and the meshing gear is a ring gear, not a pinion gear, fastened to the stationary housing. It is also likely that all seals, both apex, arcuate, and face, would be mounted in the stationary housing rather than the moving rotor.
Accordingly, an object of the present invention is to provide a rotary device having means facilitating an increased crankshaft diameter.
Another object of the present invention is to provide a rotary device having means for increasing the pitch diameter of both the pinion and ring gears without affecting the size or operating characteristics of such device or rotor profile, thereby facilitating an increased crankshaft diameter.
Another object of the present invention is to provide in a rotary device a means for still further increasing the pitch diameter of the pinion gear, and thus facilitating a further increase in power shaft diameter, of a rotary expansion or compression device, by eliminating the need for the heretofore required ring gear-pinion gear pitch diameter ratio.
These and other objects of the present invention will become apparent with reference to the drawings, the description of the preferred embodiment and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a first embodiment of the improved rotary unit of the present invention.
FIG. 2 is a sectional view of the embodiment of FIG. 1 as viewed along the section line 2--2 of FIG. 1.
FIG. 3 is a pictorial, broken apart view showing the ring and pinion gear assembly and associated gear rotational means structure of the embodiment of FIGS. 1 and 2.
FIG. 4 is a sectional view showing a second embodiment of the improved rotary unit of the present invention.
FIG. 5 is a sectional view of the embodiment of FIG. 4 as viewed along the section line 5--5 of FIG. 4.
FIG. 6 is a further sectional view of the embodiment of FIG. 4 as viewed along the section line 6--6 of FIG. 4.
FIG. 7 is a pictorial, broken apart view showing the ring and pinion gear assembly and associated gear rotational means structure of the embodiment of FIGS. 4, 5 and 6.
FIG. 8 is a schematic diagram showing the manner by which correcting gears are determined for the second embodiment of the present invention.
FIG. 9 is a sectional view of an outer envelope type rotary unit constructed in accordance with the second embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1, 2 and 3 show a first embodiment of a rotary device of the present invention, while FIGS. 4, 5, 6 and 7 illustrate a second embodiment of a rotary device. The first embodiment shows a rotary expansion power unit having an epitrochoidal cavity with two lobes in which the conventional 3:2 ratio between the pitch diameters of the ring and pinion gears is maintained, but the conventional 6:1 and 4:1 ratios of ring gear pitch diameter to rotor eccentricity and pinion gear pitch diameter to rotor eccentricity, respectively, is altered. The second embodiment shows a rotary expansion power unit having an epitrochoidal cavity with two lobes in which neither the 3:2 ratio of ring gear pitch diameter to pinion gear pitch diameter nor the 6:1 and 4:1 ratios of ring gear pitch diameter to rotor eccentricity and pinion gear pitch diameter to rotor eccentricity are maintained.
With reference to FIGS. 1 and 2, the rotary device of the present invention comprises a housing identified by the general reference numeral 11, a rotor 12 and a crankshaft or power shaft 13. The housing 11 includes a pair of opposite end walls 14 and 15 which are axially spaced from each other along the center axis 16 of the power shaft 13. The housing 11 also includes a peripheral wall 17 positioned between the sidewalls 14 and 15 at their outer edges to define an epitrochoidal cavity 20 which is symmetrical with respect to the axis 16. As illustrated best in FIG. 2, the cavity 20 includes a pair of epitrochoidal lobes 21 and 22 which intersect at a pair of lobe junctions 23 and 24 to define the minor axis of the housing. A pair of "o" rings 62, 62 (FIG. 1) or other sealing means such as a gasket are disposed between the housing sidewalls 14 and 15 and the edges of the peripheral wall 17 to seal the cavity 20. The power shaft 13 is rotatably mounted at one end in the bearing insert or housing end plate 19 which in turn is secured to the sidewall 15 by a plurality of bolts 18 or other appropriate connecting means. A bearing sleeve 51 is disposed between the rotating power shaft 13 and the stationary housing end plate 19. The other end of the power shaft 13 is rotatably mounted with respect to a portion of the sidewall 14 by the sleeve bearing 50.
The power shaft 13 includes a first eccentric member or lobe 25 having a generally cylindrical outer surface 48. The lobe 25 is circular in transverse section and is concentric about a second axis 28 parallel to and spaced from the center crankshaft axis 16 by the distance "e". In the art, this distance "e" is referred to as the eccentricity of the rotor. The rotor 12 is rotatably mounted relative to the outer cylindrical surface 48 via the annular sleeve bearing 26. The rotor 12 is symmetrical about the axis 28 of the eccentric lobe 25; hence, the rotor 12 and the eccentric lobe 25 are concentric with their center axis being radially displaced from the center axis 16 of the power shaft 13 by the eccentricity "e".
The rotor 12 includes a pair of opposite outer sidewall surfaces 30 and 31 which are adjacent and in slightly spaced relation to the inner surfaces of the housing sidewalls 14 and 15, respectively. The sidewall surfaces 30 and 31 are connected by a plurality of smooth epitrochoidal flank surfaces 32, 33 and 34 which intersect at apices 35, 36 and 37 (FIG. 2). The apices 35, 36 and 37 define a plurality of fluid expansion (or compression as the case may be) chambers 56, 57 and 58 (FIG. 2). An interior cylindrical surface of the rotor supports the sleeve bearing member 26 for rotational connection with the outer cylindrical surface 48 of the eccentric lobe 25.
As illustrated best in FIG. 1, the side surfaces 30 and 31 of the rotor provide a supporting surface for the plurality of seal members 55 and 54, respectively. These seal members 55 and 54, together with the apices 35, 36 and 37 define a plurality of expansion fluid cavities for the introduction of expansion fluid into the various expansion chambers of the power unit as fully understood in the prior art and as particularly shown in U.S. Pat. No. 4,047,856. The housing is provided with appropriate steam or expansion fluid passages to provide expansion fluid to the expansion cavities or chambers 56, 57 and 58. The rotary power unit also includes appropriate valving means to direct the expansion fluid from the passages into the expansion fluid chambers 56, 57 and 58 in a manner conventional in the art.
In conventional prior art rotary expansion power units such as the one illustrated in U.S. Pat. No. 4,047,856, a pair of phasing gears are provided to properly position the rotor 12 within the epitrochoidal cavity 20 during rotation of the power shaft 13. These prior art phasing gears, one of which is an internal ring gear connected with the planetating rotor and the other of which is an external pinion or stationary gear connected with an end wall of the housing, function to insure that the apices 35, 36 and 37 (FIG. 2) of the rotor are in contact with a portion of the surface of the epitrochoidal cavity 20 at all times during operation of the unit. To maintain such contact, these phasing gears must have a specific relationship to one another and a specific relationship to the eccentricity of the rotor. This relationship which is accepted in the prior art for an epitrochoidal cavity with two lobes and a rotor with three apices requires the pitch diameter of the internal ring gear to be six times the eccentricity "e" of the rotor and the pitch diameter of the pinion or stationary gear to be four times the rotor eccentricity "e". Because of the above necessary relationship, the ratio of the pitch diameter of the ring gear to the pitch diameter of the pinion or stationary gear must be 3:2. In other words, the ring gear pitch diameter must be one and one half times larger than the pinion gear pitch diameter and must include one and one half times as many gear teeth. Because the power shaft of rotary expansion power units must pass through the inside of the pinion gear, these prior art rotary units are limited to having a power shaft with a diameter less than the pitch diameter of the pinion gear. As set forth in the Background of Invention section, this limitation on the diameter of the power shaft leads to several limitations and disadvantages with regard to prior rotary power units. With the structure of the present invention, the pitch diameter of the pinion gear can be significantly increased without regard to the 3:2 ring gear-pinion gear ratio and without regard to the 6:1 and 4:1 ratios of the ring gear to eccentricity and pinion gear to eccentricity. Because of this permitted increase in pinion gear diameter, the power shaft diameter can also be increased.
One embodiment of the ring and pinion gear assembly to permit such enlargement of the pinion gear is illustrated in FIGS. 1-3. As shown, such embodiment includes an internal ring gear 41 with a plurality of internal gear teeth connected with the rotor 12 and an external pinion gear 42 with a plurality of external gear teeth adapted for appropriate meshing with the teeth of the ring gear 41. In this embodiment, the pitch diameter PD 1 of the pinion gear 42 is greater than the normally accepted four times the rotor eccentricity and the pitch diameter RD 1 of the ring gear 41 is greater than the normally accepted six times the rotor eccenticity "e". The ratio between the pitch diameters of the ring gear 41 and the pinion gear 42, however, is maintained at 3:2. Because the ring gear 41 and pinion gear 42 are no longer related to the eccentricity with the conventional relationship, it is necessary to compensate for this variance. Such compensation is accomplished by mounting the pinion gear 42 on its own eccentricity and appropriately planetating it about the center shaft axis 16. As illustrated, the pinion gear 42 is supported in rotational relationship with respect to a second eccentric portion or lobe 38 integrally formed with the power shaft 13. A cylindrical sleeve bearing 40 is disposed between the inner cylindrical surface of the pinion gear 42 and the outer cylindrical surface 39 of the lobe 38 to rotatably mount the gear 42. The eccentric lobe 38 has its axial center along a third axis 44 which is parallel to and spaced from the center line 16 of the power shaft 13 by the distance "d".
Mounting the enlarged pinion gear 42 eccentrically with regard to the center line 16 only partially compensates for the deviation from the necessary 6:1 and 4:1 relationships between the ring gear pitch diameter RD 1 and rotor eccentricity "e" and between the pinion gear pitch diameter PD 1 and rotor eccentricity "e". To fully compensate for this deviation, the enlarged pinion gear 42 must also be planetated on its axis 44 about axis 16. In the embodiment of FIGS. 1-3, means must be provided for causing such movement of the gear 42 about its axis 44 at the rate of one rotation per revolution. With such a structure, the gear 42 will revolve about the axis 16, but will not rotate with respect to that same axis.
As shown in FIGS. 1 and 3 and particularly in FIG. 3, the pinion gear 42 includes an enlarged mating disc 45 integrally joined via the intermediate section 46 with the portion of the gear 42 which meshes with the ring gear 41. The mating disc 45 includes a pair of female key slots 47, 47 diametrically opposed to each other about the periphery of the disc 45. These key slots 47,47 are generally rectangular recessed portions disposed near the outer periphery of the plate 45 and on the side opposite the gear 42. As shown, the slots 47, 47 are open at the outer periphery of the plate 45 and extend in a generally radial direction toward the center axis 44 of the gear 42.
An annular intermediate disc or rotational movement control means 49 is positioned adjacent to the mating disc 45 in generally face-to-face relationship. The disc 49 is generally annular in shape and includes a first pair of diametrically opposed male key portions 53,53 disposed near its outer periphery. These key portions 53,53 extend in a generally radial direction toward the center of the disc 49 and are adapted for operative engagement with the key slots 47,47 in the mating disc 45. As shown, the slots 47,47 must be long enough to accommodate the sliding movement of the key portions 53,53 therein during revolution of the gear 42 about the power shaft axis 16. Thus, the slots 47, 47 and keys 53,53 permit limited relative movement between the discs 45 and 49 in a radial direction parallel to the elements 47,47 and 53, 53 but precludes relative rotational movement between the discs 45 and 49.
The side of the intermediate disc 49 opposite the key portions 53, 53 is provided with a pair of diametrically opposed male key elements 52,52 also disposed at the periphery of the disc 49. These elements 52,52 are similar to the elements 53, 53, but are rotationally displaced therefrom by an angle of 90°. The key elements 52, 52 are adapted for engagement with a pair of female slot portions 54, 54 formed in a rotational movement control portion of the end housing 19. The slots 54,54 and the key elements 52, 52 permit limited movement between the plate 49 and the stationary end housing 19 in a radial direction parallel to the elements 52, 52 and 54, 54, but precludes relative movement between the plate 49 and end housing 19. The end housing 19 includes a generally cylindrical portion 55 in which the slots 54, 54 are disposed and a flange portion 56 with a plurality of holes 58 for connection with the main housing of the unit.
As the shaft 13 rotates, the pinion gear 42 revolves about the center 16. However, because of the engagement between the slots 47,47 and keys 53,53 and engagement between the slots 54,54 and keys 52,52, rotational movement of the pinion gear 42 with respect to the crankshaft axis 16 is prevented.
In designing and constructing the ring and pinion gear assembly of FIGS. 1-3 as described above, it can be shown that the amount of eccentricity "d" of the pinion gear 42 must always be equal to the following:
d=r/2-e, where:
d=eccentricity of the pinion gear 42
r=pitch radius of the pinion gear 42
e=rotor eccentricity
As illustrated in the preferred embodiment of FIGS. 1-3, it can be seen that the eccentricity "d" of the pinion gear 42 is exactly 180° opposite the rotor eccentricity "e".
Reference is next made to FIGS. 4-7 which illustrate the second embodiment of the present invention. As discussed previously, the embodiment of FIGS. 1, 2 and 3 provides compensation means for a structure in which the ring gear and pinion gear pitch diameter ratio of 3:2 is maintained, but the 6:1 and 4:1 ratios of the ring gear pitch diameter to rotor eccentricity and pinion gear pitch diameter to rotor eccentricity is altered. According to the embodiment of FIGS. 4-7, it is possible to gain a still larger possible power shaft for the same rotor profile or outer limit by increasing still further the already enlarged pinion gear.
The general structure of the rotary device illustrated in FIGS. 4 through 7 is similar to the structure illustrated in FIGS. 1-3. Thus, similar elements are identified by the same reference numerals. The embodiment of FIGS. 4-7 includes a housing 11 having a pair of housing ends 14 and 15 and a peripheral housing section 17 connected at its edges to the inner surfaces of the housing side members 14 and 15. A pair of "o" rings 62,62 or other suitable sealing members are provided between the housing members 14, 15 and 17 to provide an effective seal. The power shaft 13 extends through the central portion of the housing and is supported for rotation within the housing by the bearing sleeve members 50 and 51. The sleeve bearing 50 is supported by the housing side member 14 while the sleeve bearing member 51 is supported by the end housing member 19. The end housing member 19 is secured to the housing side member 15 by a plurality of threaded bolts 18. The embodiment of FIGS. 4-7 further includes a rotor 12 and appropriate seal members 54 and 55 disposed between the rotor 12 and the inner surfaces of the housing side members 14 and 15. The seal members 54 and 55, together with the apex seals 35, 36 and 37, define a plurality of expansion chambers within the housing 11 in a manner conventional in the art. Appropriate means are also provided for controlling the supply of expansion fluid to such chambers in a manner conventional in the art. The rotor 12 is rotatably supported with respect to the eccentric lobe portion 25 integrally formed with the power shaft 13. The eccentric lobe 25 includes an outer cylindrical surface 48 which supports the rotor 12 in rotational relationship via the sleeve bearing member 26. As with the structure illustrated in FIGS. 1-3, the center axis 28 of the lobe 25 is displaced from the center line 16 of the power shaft 13 by the eccentricity "e".
The embodiment of FIGS. 4-7 further includes first and second gear means comprising an internal ring gear 59 having a plurality of internal gear teeth and an external pinion gear portion 60 having a plurality of external gear teeth adapted for engagement with the teeth of the internal ring gear 59. The ring gear 59 is fixed with respect to the rotor 12 and thus rotates and revolves therewith. The pinion gear portion 60, unlike the prior art structures, is rotatably mounted on a second eccentric lobe portion 61 integrally formed with the power shaft 13. A sleeve bearing 64 is provided between the outer cylindrical surface of the lobe 61 and the inner cylindrical surface of the pinion gear portion 60 to facilitate such relative rotational movement. The center line 44 of the lobe 61 and thus also the pinion gear portion 60 is offset from the power shaft centerline 16 by the distance "d". This eccentricity of the gear portion 60 compensates for the fact that the 6:1 and 4:1 ratios of ring gear 59 pitch diameter to rotate eccentricity "e" and pinion gear 60 pitch diameter to rotor eccentricity "e", respectively, is not maintained. For example, the pitch diameter RD 2 of the ring gear 59 is approximately fourteen times the rotor eccentricity "e" while the pitch diameter PD 2 of the pinion gear portion 60 is over ten times the rotor eccentricity "e".
In the embodiment of FIGS. 4-7, the pinion gear portion 60 is enlarged so that the ratio between the pitch diameters of the ring gear 59 and pinion gear portion 60 is less than 3:2. Because the 3:2 relationship no longer exists, due to the pinion gear portion 60 being larger than normal, the pinion gear portion 60 tends to rotate the ring gear 59 and rotor 12 slower than it should. Thus, it is necessary to rotate the pinion gear portion 60 slightly during each revolution of the power shaft 13 in order that the intentional "error in rotation" EIR is corrected by an appropriate rotation in the opposite direction. In the preferred embodiment of FIGS. 4-7, this correcting rotation is accomplished by third and fourth correcting gear means comprising the internal ring gear portion 68 with a plurality of internal gear teeth and the external pinion gear 69 with a plurality of external gear teeth.
As mentioned above, the pitch diameter RD 2 of the ring gear 59 is approximately fourteen times the rotor eccentricity "e" and the pitch diameter PD 2 of the pinion gear 60 is over ten times the rotor eccentricity "e". With these dimensions neither the 3:2 relationship between the pitch diameters RD 2 and PD 2 nor the 6:1 and 4:1 ratios between the ring gear pitch diameter RD 2 and rotor eccentricity and pinion gear pitch diameter PD 2 and rotor eccentricity are maintained. To compensate for these alterations, the pinion gear 60 must be mounted on an eccentric relative to the center line 16 of the power shaft 13 as described above. In addition, unlike the structure of FIGS. 1-3 in which it was necessary only to prevent the pinion gear from rotating as it revolved about the power shaft axis 16, the structure of FIGS. 4-7 requires that a certain relative rotation be imparted to the pinion gear 60 during its revolution about the axis 16. This rotation is necessary to compensate for the tendency of the larger pinion gear 60 to cause the ring gear 59, and thus the rotor 12, to move slower than it should.
To accomplish this correcting rotation, the pinion gear portion 60 is integrally joined with the ring gear portion 68 via the intermediate sections 65 and 66. This ring gear portion 68 is concentric with respect to the pinion gear portion 60 and is centered about the axis 44. The gear portion 68 includes a plurality of internal teeth adapted for meshing engagement with the external teeth of the pinion or stationary gear 69. The gear 69 is mounted in a fixed position within a portion of the end housing 19 by appropriate means. By varying the size relationship between the pitch diameters RD 3 and PD 3 of the ring gear portion 68 and the pinion or stationary gear 69, the amount which the ring gear 68, and thus the internal pinion gear 60, rotates during each revolution of the power shaft 13 can be controlled.
The following formula is used to calculate the pitch diameters RD 3 and PD 3 of the ring gear 68 and pinion gear 69, respectively: ##EQU1## and D=C-2d, where:
A=pitch diameter RD 2 of the ring gear 59
B=pitch diameter PD 2 of the pinion gear 60
C=pitch diameter RD 3 of the ring gear 68
D=pitch diameter PD 3 of the pinion gear 69
e=rotor eccentricity
d=eccentricity of pinion gear 60 and ring gear 68
or ##EQU2##
In all cases involving epitrochoids with inner envelopes, the pitch diameters must satisfy the following equation: ##EQU3## Where: Z=the number of segments of the inner envelope.
Thus, in the specific case of a structure having an epitrochoidal cavity with two lobes and an inner envelope rotor with three segments or apices, Z=3, and thus the following formula applies: ##EQU4## d=eccentricity of pinion gear 60 and ring gear 68
For purposes of illustration, the eccentricity d of the second eccentric lobe 61 is 180° opposite the rotor eccentricity e in FIGS. 4-7. However, it is also within the contemplation of the present invention to set the second eccentric d at any angle less than 180° with respect to the rotor eccentric e. If the angular spacing between the eccentrics is 180°, then values for RD 3 and PD 3 leave little room for choice, which can result in undesirably large pitch diameters for the correction gears 68 and 69. If, on the other hand, the angular spacing is less than 180°, more choices become available for the correcting gear pitch diameters and there is a better likelihood that practical gear diameters can be found for 68 and 69.
For example, FIG. 8 illustrates a determination of the pitch diameters for inner envelope devices correcting gears 68 and 69 when the angular spacing γ between the rotor eccentric e and the secondary eccentric d is less than 180°. Let e=1/2" and Z=3, such that the epitrochoidal cavity has two lobes and the inner envelope profile of the rotor has three apices. Conventionally, the gear ratio for the normal phasing gears would be 3:2; however, in accordance with the present invention, let RD 2 =6" and PD 2 =5", for a ratio of 6÷5=1.2 rather than 1.5. The following procedure is used to calculate the pitch diameters RD 3 and PD 3 of gears 68 and 69, where:
A=6=pitch diameter of the gear coaxial with the envelope profile=pitch diameter RD 2 of ring gear 59
B=5=pitch diameter of secondary eccentric gear engaging with gear A=pitch diameter PD 2 of pinion gear 60
C=pitch diameter of secondary eccentric gear engaging with gear D=pitch diameter RD 3 of ring gear 68
D=pitch diameter of the gear coaxial with the trochoidal profile=pitch diameter PD 3 of pinion gear 69
EIR=error in rotation of the gear coaxial with the trochoid envelope profile, 59
Z=3=a non-dimensional parameter corresponding to the number of envelope apices
e=1/2=rotary eccentricity
d=eccentricity of the secondary eccentric, 61
The following formulas apply:
If EIR is greater than 0 (gear A is a ring gear and gear B is an external pinion) then A-B=2d. If EIR is less than 0 (gear A is an external pinion and gear B is a ring gear) then B-A=2d ##EQU5##
For this example, EIR is greater than 0 and the value D/C is 0.8. Depending on the wishes of the designer and the minimum acceptable dimensions allowing the necessary meshing of the ring and pinion correction gears given a particular tooth pitch value, any values may be selected for D and C satisfying the D/C ratio determined above. As illustrated in FIG. 8, values D=4" and C=5" have been selected for gears. Further solving, d=1/2" and, using the law of cosines, γ=30°.
This approach for varying the conventional ratio of the phasing gears to permit enlargement of the crankshaft and for providing a secondary eccentric and corrective gears is the same in the case of other inner envelope trochoidal devices, such as hypotrochoids. The approach is also the same in the case of outer envelope trochoidal devices; however, as those skilled in the art will appreciate, the sequence of timing gears is the reverse of the sequence described above in connection with an inner envelope device. This is illustrated in FIG. 9 which shows an outer envelope epitrochoidal device based on the epitrochoid used to generate the profiles of the working members in the device of FIGS. 4-7. FIG. 9 shows the inventive rotor movement control arrangement whereby the sequence of timing gears is the reverse of the sequence used in the inner envelope device.
Although various minor modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
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An improved rotary device having means facilitating an increased power shaft diameter. This means includes a pair of gear elements which are not related to the eccentricity of the device or to each other in the conventional manner known in the prior art. To compensate for these discrepancies in such relationships, additional gear rotational means is needed to control the rotation and revolution of the altered gear structure to compensate for the failure to maintain the heretofore required relationships with the eccentricity and with each other. One embodiment of the invention utilizes a plurality of movement control discs to accomplish this gear compensating motion, while a second embodiment utilizes a plurality of compensating gears.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/942,518 filed Jun. 7, 2007 entitled “Flexible Power Transmission Cable for Driving a Dental Handpiece”.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a power transmission device, specifically a power transmission device having a flexible power transmission cable for driving a dental handpiece.
[0003] Dental practitioners use a variety of tools for dental treatments such as drilling, grinding, polishing, scaling and other periodontal treatments, root canal therapy and the like. A dental practitioner often uses a variety of tools for a single procedure. A drilling tool, a light source, chip air and water are often needed to perform a single procedure. Since a mouth is a small space in which to work and children or those suffering from trismus or an otherwise limited ability to open their mouth, it is often difficult to see well and operate equipment in all regions of the mouth. When a dental practitioner cannot see clearly in the field of work or reach a tooth or gum section at a particular angle, it is more likely that a painful slip can occur or the procedure is otherwise limited. Additionally, more than one hand and or person is needed to operate air, water, light and drilling devices simultaneously or seamlessly.
[0004] Dental drills are typically pneumatically or electrically driven with the motor coupled directly to a removable handpiece. Pneumatic drills are useful in high speed configurations but are difficult to accurately control with a foot pedal and often do not provide sufficient torque. Electrically driven drills provide for increased control and torque but results in a larger and much heavier handpiece due to the use of an electric motor and corresponding components proximate the handpiece. The larger size and weight of the electrically driven handpiece hinders dexterity, tires the dental practitioner faster and obstructs the mouth opening and view of the practitioner.
[0005] What is therefore needed is a dental tool that has a handpiece having characteristics of a pneumatic drill with the increased torque and precision speed of an electric motor.
BRIEF SUMMARY OF THE INVENTION
[0006] Briefly stated, the present invention is directed to an elongated flexible power transmission cable for coupling an electric motor within a control unit with a dental handpiece. The handpiece has a rotatable tool used for performing dental work within a patient's mouth. The power transmission device comprises a generally flexible and elongated cover having a proximal attachment end, a distal attachment end and a longitudinal axis that extends between the proximal and distal attachment ends. The proximal attachment end is mountable to the control unit and the distal attachment end is mountable to the dental handpiece. A generally flexible and elongated driving cable is rotatably positioned within the cover. The driving cable is generally rotatable about the longitudinal axis and has a proximal end for coupling with the electric motor and a distal end for coupling with and driving the dental handpiece. The driving cable transmits torque from the electric motor to the dental handpiece
[0007] In another aspect, the invention is directed to a power transmission device for driving a dental handpiece that has a rotatable tool for performing dental work within a patient's mouth. The power transmission device comprises a control unit housing an electric motor and a flexible power transmission cable. The flexible power transmission cable includes a generally flexible and elongated cover that has a proximal attachment end, a distal attachment end and a longitudinal axis that extends between the proximal and distal attachment ends. The proximal attachment end is mounted to the control unit and the distal attachment end is mountable to the dental handpiece. A generally flexible and elongated driving cable rotatably positioned within the cover. The driving cable is generally rotatable about the longitudinal axis and has a proximal end coupled with the electric motor and a distal end for coupling with and driving the dental handpiece such that torque is transmitted from the electric motor to the dental handpiece.
[0008] In another aspect, the invention is directed to a power transmission device for driving a dental handpiece that has a rotatable tool for performing dental work within a patient's mouth. The power transmission device comprises a control unit that houses an electric motor. The control unit has a display screen and at least one control button. A flexible power transmission cable includes a generally flexible and elongated cover that has a proximal attachment end, a distal attachment end and a longitudinal axis extending between the proximal and distal attachment ends. The proximal attachment end has a threaded collar that is removably mounted to the control unit and the distal attachment end is removably mountable to the dental handpiece. A generally flexible and elongated driving cable is rotatably positioned within the cover. The driving cable is generally rotatable about the longitudinal axis and has a proximal end coupled with the electric motor and a distal end coupled with and driving the dental handpiece such that torque is transmitted from the electric motor to the dental handpiece. A water line extends from the control unit through the flexible power transmission cable to the dental handpiece. An air line extends from the control unit through the flexible power transmission cable. A delivery system connected to the control unit delivers air and water to the air and water lines respectively. A foot pedal that controls the speed of the electric motor is connected to the delivery system.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] The foregoing summary, as well as the following detailed description of a preferred embodiment of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings an embodiment which is presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0010] In the drawings:
[0011] FIG. 1 is a perspective view of a power transmissions device having a control unit and flexible power transmission cable in accordance with a preferred embodiment of the present invention connected to a dental handpiece and schematically connected to a delivery system and foot pedal;
[0012] FIG. 2 is a left side elevational view of the flexible power transmission cable shown in FIG. 1 ;
[0013] FIG. 3 is a cross sectional view, partially broken, of the cable shown in FIG. 2 taken along line 3 - 3 in FIG. 2 ;
[0014] FIG. 4 is a left side elevational view of a handpiece coupler shown in FIG. 1 ;
[0015] FIG. 5 is a right side elevational view of the flexible power transmission cable shown in FIG. 1 ; and
[0016] FIG. 6 is a cross sectional view of the handpiece coupler shown in FIG. 5 taken along line 6 - 6 of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
[0017] Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, “left”, “lower” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of a power transmission device for driving a dental handpiece in accordance with the present invention, and designated parts thereof. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. The terminology includes the words noted above, derivatives thereof and words of similar import.
[0018] Referring to the drawings, wherein like numerals indicate like elements throughout, there is shown in FIGS. 1-6 a power transmission device, generally designated 10 , for driving a dental handpiece (handpiece) 12 . The power transmission device 10 includes a flexible power transmission cable 14 that couples a control unit 16 to a detachable drill or other handpiece 12 . The handpiece 12 is similar to those known in the art that are removably latched or coupled to the driving end of a pneumatic or electric motor. The handpiece 12 is for performing dental work on a tooth or related area as discussed in further detail below.
[0019] The control unit 16 houses electrical components and an electric motor 18 for powering and driving the handpiece 12 . The control unit 16 includes a plurality of inlet ports, partially shown at 26 , for supplying water and air for use in the handpiece 12 . The control unit 16 is operatively connected to a delivery system 20 (shown schematically) proximate a dental chair (not shown) and a foot pedal 22 (shown schematically) that is connected to the delivery system 20 . The foot pedal 22 controls the speed of the electric motor 18 . The foot pedal 22 is placed on the floor proximate the dental chair to allow the dental practitioner to control the speed of the handpiece 12 with his or her foot. The control unit 16 preferably includes a display screen 28 . The display screen 28 is preferably an LCD or similar electronic screen for displaying settings and operating conditions of the control unit 16 . The control unit 16 also preferably includes at least one control button or switch 30 for controlling various settings of the control unit 16 . Alternatively, the control buttons 30 may be positioned remotely from the control unit 16 such as on the dental chair, the delivery system 20 , the foot pedal 22 or on the flexible power transmission cable 14 proximate to the handpiece 12 . The speed of the electric motor 18 may be displayed on the display screen 28 . The control buttons 30 allow a user to set torque and speed limits of the flexible power transmission cable 14 . Other settings include but are not limited to turning on a light 66 (described further below), setting auto-reverse on, programming what specific attachment or handpiece 12 is being used and also various other pre-sets for the power transmission device 10 . The control unit 16 is preferably powered by a power supply 24 . However, the control unit 16 may alternatively be powered through the delivery system 20 .
[0020] Referring to FIGS. 1-3 , the flexible power transmission device 10 includes a proximal attachment end 32 and a distal attachment end 34 . A longitudinal axis 36 ( FIG. 3 ) extends between the proximal and distal attachment ends 32 , 34 . The flexible power transmission cable 14 includes a driving cable 38 which is generally rotatable about the longitudinal axis 36 . The driving cable 38 is preferably a braided or winding type metallic cable but the driving cable 38 may be comprised of nearly any material and configuration such that the driving cable 38 has the thinnest cross section strong enough to withstand the torque needed to the drive the dental handpiece 12 . The driving cable 38 includes a keyed proximal end 38 a that is sized and shaped to fit within or to be otherwise secured to the output shaft (not shown) of the electric motor 18 . Alternatively, the proximal end 38 a may included a threaded collar (not shown) that is threadably attached to the output shaft of the electric motor 18 . The distal end of the driving cable 38 is attached to and drives an output shaft 44 . The driving cable 38 is preferably fixedly attached to the output shaft 44 (see FIG. 6 ) but the driving cable 38 and the output shaft 44 may be integrally formed.
[0021] The flexible power transmission device 10 includes a flexible and elongated cable covering or cover 40 . The cover 40 is a flexible outer covering to protect the driving cable 38 and air and water lines 42 . The cable covering 36 is preferably constructed of a polymeric material specifically a PEEK covering. However, the cable covering 36 may be constructed of any suitable material such as a wound metal covering to provide a flexible, lightweight and durable protective cover. The cover 40 is preferably mounted or attached to the driving cable 38 at the proximal and distal attachment ends 32 , 34 of the flexible power transmission cable 14 . The cover 40 is preferably attached to the driving cable 38 by a ball bearing ring 68 or any suitable connector such that the driving cable 38 may rotate relative to the cover 40 .
[0022] The proximal attachment end 32 of the flexible power transmission cable 14 is preferably removably mounted to the control unit 16 though the power transmission cable 14 may be fixedly attached to the control unit 16 . The proximal attachment end 32 of the flexible power transmission cable 14 preferably includes a threaded collar 46 that is rotatably mounted to the proximal attachment end 32 of the flexible power transmission cable 14 and threadingly attaches to the control unit 16 . The proximal attachment end 32 of the flexible power transmission cable 14 also preferably includes a backshell 48 . The collar 46 is rotatably mounted over the backshell 48 . Tightening the collar 48 in the appropriate direction draws the proximal attachment end 32 of the flexible power transmission cable 14 toward the control unit 16 and engages the driving cable 38 with the electric motor 18 .
[0023] Referring to FIGS. 2 , 3 and 4 , the proximal attachment end 32 of the flexible power transmission cable 14 preferably includes at least one and preferably two spaced apart pins 50 for insertion within and electrical connection to the control unit 16 . The pins 50 are used to establish an electrical connection for any of the electrical components of the handpiece 12 . The proximal attachment end 32 also preferably includes a plurality of ports 42 a for connecting to the air and water lines 42 . The ports 42 a are preferably fluidly engaged with a corresponding plurality of air and water lines 42 within the control unit 16 . The ports 42 a and corresponding air and water lines 42 are preferably arranged to at least provide an air port for cooling the light 66 and other components and a port 42 c for providing chip water. The air and water lines 42 run along side of and are preferably radially outwardly spaced from the driving cable 38 and are preferably circumferentially spaced from each other within the cover 40 .
[0024] Referring to FIGS. 3 and 6 , the output shaft 44 is housed within a handpiece coupler 52 at the distal attachment end 34 of the flexible power transmission cable 14 . The output shaft 44 has a t-shaped distal end 44 a . The handpiece coupler 52 includes a coupler backshell 54 that preferably fixedly extends partially over the distal end of the cover 40 . A handpiece plug (plug) 56 extends from the distal end of the handpiece coupler 52 and preferably covers the output shaft 44 to protect users from the output shaft 44 when the handpiece 12 is removed. The handpiece 12 receives the plug 56 and snap fits into releasble engagement with the handpiece coupler 52 . A spring biased releasable catch 58 is preferably disposed within the handpiece coupler 52 . When the handpiece 12 is pulled away from the handpiece coupler 52 with a sufficient force, the catch 58 radially releases the handpiece 12 from the handpiece coupler 52 . An end cap 70 is preferably mounted to the distal end of the handpiece coupler 52 and held in place by a plurality of screws 72 ( FIG. 5 ).
[0025] The distal end 44 a of the output shaft 44 engages with a drive shaft 60 within the handpiece 12 . The drive shaft 60 drives a gear train 62 for powering a rotating tool such as a drill bit 64 . The water line 42 connects with the water line 42 c in the handpiece 12 . The water is sprayed from a nozzle 68 in the handpiece 12 and is used to clear and cool the drill bit 64 and clear or clean the work area. The light bulb 66 , positioned toward the distal end of the handpiece coupler 52 emits light from the end of the nozzle 68 in the proximity of the drill bit 64 and the work area to enable a better view when working inside the mouth. The light from the light bulb 66 is brought through the handpiece 14 to the work area through a lumen 66 b . The light bulb 66 is connected to power wires 66 a inside the cover 40 by crimped AMP or other connectors (not shown).
[0026] It will be appreciated by those skilled in the art that changes could be made to the embodiment described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiment disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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An elongated flexible power transmission cable couples an electric motor within a control unit with a dental handpiece. The handpiece has a rotatable tool used for performing dental work within a patient's mouth. The power transmission device comprises a generally flexible and elongated cover having a proximal attachment end, a distal attachment end and a longitudinal axis that extends between the proximal and distal attachment ends. The proximal attachment end is mountable to the control unit and the distal attachment end is mountable to the dental handpiece. A generally flexible and elongated driving cable is rotatably positioned within the cover. The driving cable is generally rotatable about the longitudinal axis and has a proximal end for coupling with the electric motor and a distal end for coupling with and driving the dental handpiece. The driving cable transmitting torque from the electric motor to the dental handpiece
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BACKGROUND OF THE INVENTION
Certain embodiments of the present invention generally relate to a lever-based connection assembly for engaging resisting components. More particularly, certain embodiments of the present invention relate to a mate assist assembly for connecting electrical contacts contained in separate housings.
In certain applications, electronic components require the mating of several electrical contacts, such as in automotive electrical components. The electronic component includes a connector housing that holds several electrical contacts, while a mating connector housing holds an equal number of electrical contacts. One connector housing includes male electrical contacts, while the other connector housing includes female electrical contacts. As the number of electrical contacts to be mated increases, it becomes difficult to fully join the mating connector housings because of friction between the mating electrical contacts. The connector housings are formed with a mate assist assembly that includes a lever-and-gear system to pull together the connector housings in order to overcome the frictional resistance created by the mating electrical contacts.
A mate assist assembly is described in U.S. Pat. No. 6,099,330 issued to Gundermann that includes a lever, and first and second connector housings. Each connector housing includes electrical contacts, and the first connector housing is configured to be positioned inside the second connector housing. The lever has a handle and two arms. The arms extend from, and may be rotated alongside, end walls of the second connector housing. The arms include lever surfaces that are positioned on the end walls. The second connector housing, with the handle positioned proximate a top end, may be slid over the first connector housing to a point where the electrical contacts resist further insertion. The lever then is rotated downward along a back wall of the second connector housing which causes the lever surfaces to engage cam surfaces located on end walls of the first connector housing. As the lever surfaces engage, and are resisted by, the cam surfaces, the second connector housing is pulled further downward over the first connector housing until the electrical contacts are fully mated.
Another mate assist assembly is described in U.S. Pat. No. 5,833,484 issued to Post that is similar to the '330 patent, except that the second connector housing and arms of the lever are positioned on the first connector housing. Each arm includes a pinion with gears. The first connector housing includes racks situated on the first connector housing with each rack corresponding to the gear teeth of one of the pinions. As the handle is rotated upward, the racks and pinions engage and pull the second connector housing downward into the first connector housing.
However, conventional mate assist assemblies suffer from a number of drawbacks. First, the arms of the lever extend out from the end walls of the connector housings and the handle extends across the top of the connector housings to the arms. The levers are therefore wide and bulky and may be difficult to rotate. Also, the levers interfere with electrical wire extending from the connector housings, and may prevent the mate assist assemblies from being used with certain space-confined electronic components. Secondly, the mate assist assemblies are time-consuming to assemble and install. The arms are pulled apart and slid along the end walls of the second connector housing. Then each arm is individually positioned into a retention cavity or aperture.
Thus a need remains for a mate assist assembly that overcomes the above mated problems and addresses other concerns experienced in the prior art.
BRIEF SUMMARY OF THE INVENTION
Certain embodiments provide an electrical connector that includes a first housing and a second housing having rear ends configured to receive first and second sets of electrical contacts. The first and second housings also include front ends that are matable with one another to join corresponding contacts from the first and second sets of electrical contacts. The first and second housings are movable between initial and final positions, at which the first and second sets of contacts partially and fully mate, respectively. The electrical connector includes a lever member that engages the first and second housings and moves the first and second housings between the initial and final positions as the lever member is rotated through a range of motion. The lever member includes a cam arm that has a first retention element provided on at least one side of the cam arm to engage the first housing and a second retention element provided on a peripheral surface of the cam arm to engage the second housing. The electrical connector includes a lever retention block provided within an interior region of the first housing. The lever retention block has a pivot chamber that retains the first retention element while permitting rotation of the first retention element within the pivot chamber as the lever member rotates through the range of motion.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 illustrates an isometric view of a mating assist assembly according to an embodiment of the present invention.
FIG. 2 illustrates an exploded isometric view of the mating assist assembly of FIG. 1 .
FIG. 3 illustrates an isometric view of the harness connector of FIG. 1 .
FIG. 4 illustrates an isometric view of a lever member for the mating assist assembly according to an embodiment of the present invention.
FIG. 5 illustrates an exploded isometric view of the lever member and the harness connector of FIG. 1 .
FIG. 6 illustrates a cutaway side view of the lever member of FIG. 1 positioned within the harness connector of FIG. 1 .
FIG. 7 illustrates an isometric view of the module connector of FIG. 1 .
FIG. 8 illustrates a cutaway side view of the mating assist assembly of FIG. 1 in the initial staging position.
FIG. 9 illustrates a side cutaway view of the mating assist assembly of FIG. 1 in the final mated position.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an isometric view of a mating assist assembly 10 according to an embodiment of the present invention. The mating assist assembly 10 includes a lever member 15 , a harness connector 20 , and a module connector 25 aligned along a vertical axis 26 . The harness connector 20 contains contact pockets 110 configured to receive packets that hold groups of electrical contacts. The module connector 25 holds electrical contacts configured to mate with electrical contacts in the harness connector 20 . FIG. 1 illustrates the harness connector 20 partially inserted within the module connector 25 to an initial staging position. The lever member 15 is held within, and engages, the harness connector 20 and the module connector 25 . The lever member 15 is rotatable in the direction of arrow A from the initial staging position to a final mating position (FIG. 9 ). As the level member 15 is rotated, it presses the harness connector 20 downward into the module connector 25 and fully mates the electrical contacts of the harness connector 20 and the module connector 25 with each other.
FIG. 2 illustrates an exploded isometric view of the mating assist assembly 10 of FIG. 1 . The lever member 15 includes a cam arm 185 and pivot posts 190 on opposite sides of the cam arm 185 . The harness connector 20 includes a lever retention block 82 formed in the center thereof. The module connector 25 includes a mating post 267 formed in the center thereof. The mating post 267 includes catch notches 325 . The lever member 15 is removably inserted downward in the direction of arrow I into the harness connector 20 with the cam arm 185 and the pivot posts 190 positioned within the lever retention block 82 . The lever member 15 is then rotated in the direction of arrow P about a rotational axis 27 to a top surface 50 . The harness connector 20 is then removably inserted in the direction of arrow I into the module connector 25 to the initial staging position shown in FIG. 1, at which the mating post 267 projects up into the lever retention block 82 and the cam arm 185 situated within the catch notches 325 .
FIG. 3 illustrates an isometric view of the harness connector 20 of FIG. 1 . The harness connector 20 is box shaped and includes opposing side walls 30 and opposing end walls 35 . By way of example only, the side walls 30 are formed integral with, and are perpendicular to, the end walls 35 . A perimeter around the exterior of the harness connector 20 is smaller than an interior perimeter of the module connector 25 of FIG. 1, in order that the harness connector 20 may be positioned within the module connector 25 . The harness connector 20 is symmetrical, so that the harness connector 20 may be positioned inside the module connector 25 of FIG. 1 in one of two different alignments turned 180 degrees.
The side and end walls 30 and 35 each include a rectangular recessed portion 60 that is centered in the corresponding side and end walls 30 and 35 , and that extends from a bottom surface 55 to the top surface 50 . The recessed portions 60 of the side walls 30 each include two square shaped retention protrusions 65 that extend outward. The recessed portions 60 of the end walls 35 each include a rectangular shaped retention protrusion 70 that extends outward. The retention protrusions 65 and 70 engage interior surfaces 275 (FIG. 7) of the module connector 25 as the harness connector 20 is slidably inserted into the module connector 25 and retain the harness connector 20 in the initial staging position within the module connector 25 (as explained below in more detail in connection with FIG. 7 ).
The side and end walls 30 and 35 are formed integral with thin rectangular support walls 74 and 75 , respectively, that are centered along interior surfaces of the side walls 30 and 35 . The support walls 74 and 75 extend perpendicularly inward from the side and end walls 30 and 35 , respectively. The support walls 74 and 75 are formed integral with the lever retention block 82 to hold the lever retention block 82 in a desired position. The lever retention block 82 is formed with interior side walls 80 and interior end walls 85 that define and enclose a rectangular cavity 90 . The interior side and end walls 80 and 85 include top surfaces 105 . The lever retention block 82 receives, within the cavity 90 , the mating post 267 on the module connector 25 of FIG. 2 . The side and end walls 30 and 35 , the support walls 75 , and the interior side and end walls 80 and 85 form the contact pockets 110 that extend through the harness connector 20 between the top and bottom surfaces 50 and 55 . By way of example, only the contact pockets 110 are L-shaped. The contact pockets 110 are configured to receive one or more contacts that mate with corresponding contacts in the module connector 25 . Electrical contacts (not shown) are loaded through each of the four contact pockets 110 from one end of the harness connector 20 toward a second end of the harness connector 20 . When the bottom surface 55 of the harness connector 20 is slidably inserted into the module connector 25 , the electrical contacts engage electrical contacts (not shown) situated in the module connector 25 .
The interior side walls 80 include J-shaped ribs 120 and gearing ribs 125 formed thereon. The J-shaped ribs 120 extend inward from the interior side walls 80 and are aligned opposite each other across the cavity 90 . Likewise, the gearing ribs 125 extend inward from the interior side walls 80 and are aligned opposite each other across the cavity 90 . The J-shaped ribs 120 and gearing ribs 125 that are provided on the same interior side wall 80 include lead ends that are separated by an insertion gap 170 and body sections that define a pivot chamber 171 .
The J-shaped ribs 120 include rear and front surfaces 135 and 140 that extend downward parallel to each other from the top surface 105 and curve inward toward the gearing ribs 125 to form the J shape. Side surfaces 145 of the J-shaped ribs 120 are perpendicular to the rear and front surfaces 135 and 140 and face inward toward each other across the cavity 90 .
The gearing ribs 125 include rear and front surfaces 155 and 160 that extend downward parallel to each other from the top surface 105 and curve semi-circularly and concentrically away from the front surfaces 140 of the J-shaped ribs 120 . Side surfaces 165 of the gearing ribs 125 are perpendicular to the rear and front surfaces 155 and 160 and face inward toward each other across the cavity 90 .
In operation, the lever member 15 is inserted into the cavity 90 with the pivot posts 190 of the lever member 15 (FIG. 4) sliding into the insertion gaps 170 until the pivot posts 190 are positioned in the pivot chambers 171 on top of the front surfaces 140 of the J-shaped ribs 120 and underneath and behind the rear surfaces 155 of the gearing ribs 125 . The pivot posts 190 are rectangular and thus are only insertable into the insertion gaps 170 when aligned along the vertical axis 26 . The pivot posts 190 are rotatable within the pivot chambers 171 .
The harness connector 20 is then slidably inserted into the module connector 25 . When the harness connector 20 is fully inserted into the module connector 25 , the mating post 267 (FIG. 2) of the module connector 25 extends upward through the cavity 90 between the J-shaped ribs 120 and the interior end walls 85 and between the gearing ribs 125 and the interior end walls 85 . The mating post 267 of the module connector 25 positioned within the cavity 90 of the lever retention block 82 catches the lever member 15 as the lever member 15 is rotated in the pivot chambers 171 , causing the harness connector 20 to be pulled into the module connector 25 .
FIG. 4 illustrates an isometric view of the lever member 15 for the mating assist assembly 10 according to an embodiment of the present invention. The lever member 15 includes a cylindrical handle 175 , a rectangular shaft 180 , the elbow shaped cam arm 185 , and the two rectangular pivot posts 190 . The handle 175 is formed integral with, and extends perpendicularly from, a first end of the shaft 180 to form a T-shape. The cam arm 185 is formed integral with, and extends outward from a second end of the shaft 180 . The shaft 180 includes a back surface 200 . The shaft 180 and the cam arm 185 share exterior side surfaces 195 . The shaft 180 and the handle 175 may be used to position the lever member 15 So that the pivot posts 190 rotate within the pivot chambers 171 of FIG. 2 and cause the cam arm 185 to catch or release the module connector 25 of FIG. 1 .
The cam arm 185 also includes a curved first contact wall 225 , a curved second contact wall 230 , and a curved retention wall 235 . The first contact wall 225 curves out from a back surface 220 of the cam arm 185 toward the back surface 200 of the shaft 180 to join the retention wall 235 . The retention wall 235 extends upward at an acute angle to a bottom surface 222 of the cam arm 185 to join the second contact wall 230 . The second contact wall 230 curves upward and out from the retention wall 235 to a top surface 210 of the cam arm 185 . The first contact wall 225 catches the mating post 267 of FIG. 2 and pulls the harness connector 20 of FIG. 2 down into the module connector 25 of FIG. 2 when the pivot posts 190 are rotated in the direction of arrow B about the rotational axis 27 within the pivot chambers 171 shown in FIG. 3 . The second contact wall 230 catches the mating post 267 and pushes the harness connector 20 up and out of the module connector 25 when the pivot posts 190 are rotated in the direction of arrow C about the rotational axis 27 within the pivot chambers 171 . The retention wall 235 holds and retains a front portion 380 (FIG. 7) of the mating post 267 that the first and second contact walls 225 and 230 catch.
The pivot posts 190 are aligned with each other on the opposite side surfaces 195 of the cam arm 185 and extend outward and perpendicularly away from the side surfaces 195 . The pivot posts 190 include flat side walls 240 , rounded top walls 245 , rounded bottom walls 247 , and flat exterior surfaces 250 . The side walls 240 are situated at an acute angle to the bottom surface 222 of the cam arm 185 . The side walls 240 , top walls 245 , and bottom walls 247 engage the J-shaped ribs 120 and the gearing ribs 125 when the pivot posts 190 are positioned in the pivot chambers 171 .
FIG. 5 illustrates an exploded isometric view of the lever member 15 and the harness connector 20 of FIG. 1 . In operation, the lever member 15 is oriented so that the side walls 240 of the pivot posts 190 are parallel to the vertical axis 26 . The lever member 15 may then be inserted downward in the direction of arrow D into the cavity 90 with a front surface 215 of the cam arm 185 facing toward an inner surface 121 . The lever member 15 is fully inserted in the cavity 90 with the exterior side surfaces 195 of the cam arm 185 positioned between and contacting the side surfaces 145 and 165 of the opposite J-shaped ribs 120 and the opposite gearing ribs 125 , respectively, and with the pivot posts 190 positioned within the pivot chambers 171 and resting on the J-shaped ribs 120 . When the side walls 240 of the pivot posts 190 are parallel to the vertical axis 26 , the bottom walls 247 of the pivot posts 190 contact the front surfaces 140 of the J-shaped ribs 120 and the exterior surfaces 250 of the pivot posts 190 contact the interior side walls 80 of the harness connector 20 . The lever member 15 is then rotated in the direction of arrow E about the rotational axis 27 until the back surface 200 of the shaft 180 rests on the top surface 50 of one of the end walls 35 .
FIG. 6 illustrates a cutaway side view of the lever member 15 of FIG. 1 positioned within the harness connector 20 of FIG. 1 . One side wall 240 of the pivot post 190 rests upon the front surface 140 of the J-shaped rib 120 and the other side wall 240 and the top wall 245 engage the rear surface 155 of the gearing rib 125 . The first contact wall 225 thus faces one of the interior end walls 85 and the second contact wall 230 faces downward in the direction of arrow F.
FIG. 7 illustrates an isometric view of the module connector 25 . Two side walls 260 are formed integral with, and are aligned perpendicular to, end walls 265 . A base 255 is formed integral with, and extends outward from, the side and end walls 260 and 265 . The base 255 is mounted to an electronic component (not shown), such as a radio, with the side and end walls 260 and 265 extending outward from the electronic component. The mating post 267 is also mounted to the electronic component and centered between the side and end walls 260 and 265 . Electrical contacts (not shown) extend from the electronic component through the module connector 25 around the mating post 267 and between the side and end walls 260 and 265 . The module connector 25 is symmetrical throughout, so the module connector 25 may be mounted on the electronic component in one of two different alignments turned 180 degrees.
Each side and end wall 260 and 265 includes two upper protrusions 290 and two lower protrusions 295 that are generally centered on, and extend inward from, the interior surface 275 . The upper protrusions 290 are aligned next to each other along a top surface 280 , and the lower protrusions 295 are aligned next to each other and are below the upper protrusions 290 to form a retention gap 300 between the upper protrusions 290 and the lower protrusions 295 . The retention gap 300 is generally similar in size to the retention protrusions 65 and 70 of the harness connector 20 of FIG. 3 . Therefore, when the harness connector 20 is initially positioned into the initial staging position inside the module connector 25 , the retention protrusions 65 and 70 engage and slide past the upper protrusions 290 , and are retained in the retention gap 300 . When the lever member 15 is rotated upward in the direction of arrow G (FIG. 8) about the rotational axis 27 and the harness connector 20 is pulled further downward in the direction of arrow L (FIG. 8) to connect the electrical contacts, the retention protrusions 65 and 70 of the harness connector 20 of FIG. 3 slide out of the retention gap 300 over the lower protrusions 295 to a resting position below the lower protrusions 295 . The retention, lower, and upper protrusions 65 , 70 , 295 , and 290 thus engage each other to retain the harness connector 20 in the staging position in the module connector 25 .
The mating post 267 includes opposed parallel side walls 305 , and opposed parallel end walls 310 extending upward through an interior region of the module connector 25 . The side walls 305 include the opposed U-shaped catch notches 325 , which are defined by flat inner walls 340 and a concave bottom wall 345 . The side walls 305 may be formed integral with, and aligned perpendicular to, the end walls 310 . The side and end walls 305 and 310 engage and slide along the interior side and end walls 80 and 85 , respectively, when the harness connector 20 is inserted into the module connector 25 .
The mating post 267 includes resistance portions 320 that each have three sloped walls 355 and a top surface 360 . Two of the sloped walls 355 extend upward toward each other at an obtuse angle from exterior surfaces 330 of the side walls 305 , and one of the sloped walls 355 extends upward at an obtuse angle from the exterior surface 330 of one of the end walls 310 . All three sloped walls 355 are joined to the top surface 360 above the side and end walls 305 and 310 . The shaft 180 of FIG. 4 is positioned horizontally on top of one of the top surfaces 360 perpendicular to the vertical axis 26 when the harness connector 20 is in the staging position within the module connector 25 . Each resistance portion 320 also includes a resistance wall 365 that extends vertically downward from the top surface 360 between, and perpendicular to, the side walls 305 to a camming tooth 315 . The resistance walls 365 are positioned to engage and resist the shaft 180 as the shaft 180 is moved from a horizontal position on top of one of the top surfaces 360 upward to a position at an acute angle to the vertical axis 26 .
The camming teeth 315 are situated between the side walls 305 and include ridged top portions 370 , ridged bottom portions 375 , and the flat front portions 380 . Each front portion 380 is perpendicular to, and aligned on a plane with, the inner walls 340 of one of the catch notches 325 . Each top portion 370 extends upward toward one of the resistance walls 365 at an obtuse angle to the front portion 380 and each bottom portion 375 extends downward toward one of the resistance walls 365 at an obtuse angle to the front portion 380 .
FIG. 8 illustrates a cutaway side view of the mating assist assembly 10 of FIG. 1 in the staging position. The upper and lower protrusions 290 and 295 of the module connector 25 engage the protrusions 65 of the harness connector 20 . The first contact wall 225 is positioned proximate the bottom portion 375 of one of the camming teeth 315 , and the second contact wall 230 is positioned above the top portion 370 of the camming tooth 315 . The handle 175 is then used to rotate the shaft 180 upward in the direction of arrow G about the rotational axis 27 . As the shaft 180 is rotated, the pivot posts 190 rotate in the direction of arrow G about the rotational axis 27 within the pivot chambers 171 causing the first contact wall 225 to move upward in the direction of arrow N and catch the bottom portion 375 of the camming tooth 315 . As the first contact wall 225 pushes against, and is resisted by, the bottom portion 375 , the pivot posts 190 are pushed downward in the direction of arrow L against the J-shaped ribs 120 and thus position the harness connector 20 further downward into the module connector 25 .
FIG. 9 illustrates a side cutaway view of the mating assist assembly 10 of FIG. 1 in the final position. When the harness connector 20 has been fully inserted into the module connector 25 , the shaft 180 is positioned at an angle, generally 60 degrees, to the top surface 50 , and the top walls 245 of the pivot posts 190 engage the rear surfaces 155 of the gearing ribs 125 and the bottom walls 247 of the pivot posts 190 engage the front surfaces 140 of the J-shaped ribs 120 . The mating post 267 extends through the cavity 90 of the lever retention block 82 of FIG. 2 . The J-shaped ribs 120 and gearing ribs 125 are positioned in the catch notches 325 above the bottom walls 345 and between the inner walls 340 of the mating post 267 . The harness connector 20 may be removed from the module connector 25 by rotating the lever member 15 back downward in the direction of arrow J about the rotational axis 27 until the shaft 180 is positioned on top of the top surface 50 . As the lever member 15 is rotated in the direction of arrow J about the rotational axis 27 , the second contact wall 230 engages the top portion 370 of the camming tooth 315 and pushes downward in the direction of arrow K against the top portion 370 . The rear surfaces 155 of the gearing ribs 125 push downward in the direction of arrow K against the pivot posts 190 and retain the pivot posts within the pivot chambers 171 . Therefore, as the second contact wall 230 pushes downward in the direction of arrow K against the top portion 370 of the camming tooth 315 , the pivot posts 190 are pulled upward in the direction of arrow M and likewise pull upward in the direction of arrow M the J-shaped ribs 120 and gearing ribs 125 , and thus lift the harness connector 20 partially out of the module connector 25 . The harness connector 20 may then be fully removed from the module connector 25 by hand or a tool.
In an alternative embodiment, the cam arm 185 , pivot posts 190 , and mating post 267 may be oriented so that the shaft 180 of the lever member 15 may be positioned upright at a 90 degree angle to the top surfaces 50 when the harness connector 20 is fully inserted into the module conductor 25 . Similarly, the cam arm 185 , pivot posts 190 , and the mating post 267 may be oriented so that the shaft 180 of the lever member 15 is vertically upright and parallel with the vertical axis 26 when the harness connector 20 is initially inserted into the module connector 25 to the staging position. The lever member 15 may then be rotated downward in the direction of arrow J (FIG. 9) about the rotational axis 27 (FIG. 9) until the shaft 180 is horizontal and resting upon the top surface 50 of an end wall 35 to fully insert the harness connector 20 into the module connector 25 .
The mating assist assembly 10 takes up less space and thus may be used with a greater variety of electronic components. Also, the mating assist assembly 10 is easily assembled by lowering the lever member 15 within the pivot chambers 171 of the harness connector 20 and then positioning the harness connector 20 within the module connector 25 . Thus, assembling and implementing the mating assist assembly 10 may require limited time and effort.
While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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An electrical connector is provided including first and second housings having rear ends configured to receive first and second sets of electrical contacts. The first and second housings have front ends that are matable with one another to join corresponding contacts from the first and second sets. The first and second housings are movable between initial and final positions. The electrical connector includes a lever member engaging the first and second housings and moving the first and second housings between the initial and final positions as the lever member is rotated through a range of motion. The lever member includes a cam arm having a first retention element and a second retention element. The electrical connector includes a lever retention block within an interior region of the first housing that has a pivot chamber that retains, and permits the rotation of, the first retention element within the pivot chamber.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a retainer for detachably securing a web-like material, such as a table skirt to a flat surface or table. More particularly, the invention relates to a flexible retainer capable of being attached to table top edges, wherein a table skirt is secured to the retainer using hook and loop fasteners.
[0003] This application claims the benefit of U.S. Provisional Application No. 60/250,451 entitled “PLASTIC RETAINER,” filed on Dec. 1, 2000.
[0004] 2. Description of the Prior Art
[0005] Table skirts are commonly placed around the periphery of various types of tables in order to improve the appearance of the tables. The table skirts must be attached to the tables in such a manner that they resist falling or shifting when exposed to various conditions, such as wind or frequent contact by people. On the other hand, it often becomes necessary to remove a table skirt from a table for cleaning or pressing when the table skirt becomes soiled or wrinkled. As such, various fastening devices have been employed to hold the table skirts in place during use and also to allow easy removal of the table skirts from the tables.
[0006] Conventionally, a table skirt is attached to a table top using snap buttons. The male components of the snap buttons are sewn to a strip of material that is secured to the table edge by, e.g., an adhesive. The female components of the snap buttons are sewn along an edge of the table skirt. The female components may then be snapped into the male components to retain the table skirt around the table edge. The table skirt may be detached from the table edge by simply unsnapping the buttons. Unfortunately, attachment of the table skirt to the table top using such buttons may be time consuming since each button must be snapped on individually.
[0007] More recently, plastic retainers have been used to hold table skirts around the periphery of table tops. FIG. 1 depicts one prior art type of plastic retainer 110 , which includes a planar primary member 120 , an upper member 140 and a lower member 160 . Primary member 120 is typically square or rectangular in shape, and includes a hook portion 180 , of a hook and loop type fastener, on its back surface. This hook portion may be extruded as part of the manufacture of the retainer or may be attached, such as through adhesion.
[0008] Still referring to FIG. 1, the prior art retainer is typically attached to the edge of a table top by engaging the upper surface of the table top with upper member 140 , and by engaging the lower surface of the table top with lower member 160 . A common flaw with this type of retainer is the manner in which it engages a flat surface, such as a table. As the lower member is biased against the edge of the flat surface, the leg deforms. In order to maintain the retainer in place upper member 140 exerts pressure against one side of the flat surface, while the lower member 160 exerts pressure to the opposite side of the flat surface. Due to the design of the prior art retainers, this pressure is not evenly distributed, and the retainers have a tendency to disengage, through slippage, from the flat surface. The lack of proper pressure distribution is due to the upper member 140 not having its flat surface engaging portion directly above the lower member's 160 flat surface engaging portion. The predetermined spacing d 10 of the prior art determines to which sized tables retainer 110 may be attached. The predetermined spacing is most commonly ¾ inch or ⅜ inch and pertains to the height of the edge of the table top. After the prior art retainer is secured to a table top in this manner, hook portion 180 remains exposed so that a loop portion (not shown) attached to a table skirt (also not shown) may engage hook portion 180 . Generally, a plurality of retainers are secured around one or more sides of the table top, and then the table skirt is attached to the plurality of retainers. The table skirt may be removed from the table top by separating the hooks and loops.
[0009] Upper member 140 of the prior art retainer typically extends perpendicularly from primary member 120 . Lower member 160 extends from the lower end of the primary member. Still referring to FIG. 1, first leg 162 of the lower member is typically much shorter than second leg 164 , and typically slants away from the table, and toward the table skirt, when the retainer is engaged with a table. Thus, a skirt using the prior art retainer does not lay flat along a vertical plane. This can result in an undesired appearance of the table skirt and/or a “bunching up” of the table skirt due to the outward slant of the lower member. Finally, the conventional prior art plastic retainers are relatively rigid, while there is a need for flexibility to easily secure the retainer to, and remove the retainer from, the table top edge. In particular, primary member 120 typically consists of a unitary (fingerless and notchless) rectangular piece of plastic, and therefore, is relatively rigid. Moreover, leg 162 , being short relative to leg 164 , further contributes to the retainer's rigidity.
[0010] Guebert et al., U.S. Pat. No. 4,237,958, disclose a draper connector assembly. Guebert et al. show a retainer protruding backwardly (away from the plane of the primary member in a direction opposite the upper member). Furthermore, Guebert et al. disclose a primary member without any hook mountable flexibility-contributing fingers and, therefore, does not teach the invention as claimed.
[0011] Ehrlich, U.S. Pat. No. 5,060,712, discloses a table skirt-attaching method. Ehrlich shows a notchless and fingerless (albeit perforated) rectangular, vertically-oriented primary member that is relatively rigid, and that would necessarily bow (or spring) outward upon engagement of the retainer with a table edge. Thus, Ehrlich does not teach the invention as claimed.
SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention is directed to a flexible retainer for detachably securing a web-like material, such as a table skirt to a flat surface or table, where the retainer substantially obviates one or more of the problems that are due to the limitations and disadvantages of the related art described above.
[0013] The retainer comprises a primary member having an upper end, a lower end, a front surface and a back surface. The retainer further comprises an upper member that extends from the upper end of the front surface of the primary member. The retainer further comprises a lower member that extends from the lower end of the primary member. The lower member is substantially U-shaped having first and second legs. The first leg extends downward, and away from the major plane of the primary member in the same direction as the upper member—that is, frontwardly. The retainer is attachable to the edge of a table top by engaging an upper surface of the table top with the upper member and a lower surface of the table top with the lower member.
[0014] Extending upward from the lower end of the primary member are a plurality of slots, which define outside fingers of the primary member. Preferably, there are two slots, and therefore two fingers. The distance between these slots define the width of the lower member. The purpose of these slots is to improve the flexibility of the retainer, while maintaining the primary member's surface area for disposition of the hook fasteners. Further contributing to the flexibility of the retainer, first and second legs of the lower member are substantially equal in length. In the preferred embodiment, there is a hook portion positioned on the back surface of the primary member that is capable of engaging a loop portion positioned on a table skirt. The hook portion comprises a plurality of hook patches, preferably integral with the primary member. The upper member may comprise a variety of shapes, including substantially triangular or substantially bell-shaped. The retainer is preferably made from a substantially transparent plastic, such as polyolefin, polycarbonate, nylon or the like.
[0015] The first leg necessarily extends frontwardly (towards the table), in either a slant or in a serpentine, S-shaped bend—which serves as a convenient axis of rotation for the lower member as the retainer is biased into or out of engagement with a table edge, whereas the frontward extension eliminates any protrusion of the retainer through the vertical plane of the table skirt.
[0016] The present invention is further directed towards a method of securing web-like materials, such as skirting, to a flat surface, such as the edge of a table top. The retainers comprise a primary member with an upper end, a lower end, a front surface facing frontwardly, a back surface opposite the front surface, and a hook portion of a hook and loop type fastener formed on the back surface. The retainer further includes a frontwardly extending upper member, a substantially U-shaped lower member having a first leg extending frontwardly from the lower end, and a second leg extending from the first leg. A plurality of the retainers are then attached to the edges of a flat surface, such as a table top, by engaging the upper surface of the flat surface with the upper member, and by engaging the lower surface of the flat surface with the lower member. The hook portion of the retainer is then engaged by the loop portion of the web-like material, thereby providing skirting to flat surfaces, such as tables.
[0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings are included to provide a further understanding of the invention and are incorporated as part of this specification. The drawings illustrate two embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0019] [0019]FIG. 1 is a side elevation view of a prior art retainer for securing a table skirt to a table top;
[0020] [0020]FIG. 2 is a front perspective view of one embodiment of a retainer of the present invention;
[0021] [0021]FIG. 3 is a rear perspective view of the retainer of FIG. 2;
[0022] [0022]FIG. 4 is a side elevation view of the retainer of FIG. 2;
[0023] [0023]FIG. 5 is a front elevation view of the retainer of FIG. 2;
[0024] [0024]FIG. 6 is a side view of the retainer of FIG. 2;
[0025] [0025]FIG. 7 is a top plan view of the retainer of FIG. 2;
[0026] [0026]FIG. 8 is a bottom plan view of the retainer of FIG. 2;
[0027] [0027]FIG. 9 is a front perspective view of a 2 nd embodiment of the present invention;
[0028] [0028]FIG. 10 is a rear perspective view of the retainer of FIG. 9;
[0029] [0029]FIG. 11 is a rear elevation view of the retainer of FIG. 9;
[0030] [0030]FIG. 12 is a front elevation view of the retainer of FIG. 9;
[0031] [0031]FIG. 13 is a side elevation view of the retainer of FIG. 9;
[0032] [0032]FIG. 14 is a top plan view of the retainer of FIG. 9; and
[0033] [0033]FIG. 15 is a bottom plan view of the retainer of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0035] [0035]FIGS. 2 through 8 illustrate one embodiment of a retainer of the present invention, while FIGS. 9 through 15 illustrate another embodiment of a retainer of the present invention. The different embodiments are directed to retainers for detachably securing web-like materials, such as table skirts, and having slightly different structural features serving slightly different purposes. In particular, FIGS. 2 through 8 are directed to a table top having an edge with a height of about ⅜ inch, while FIGS. 9 through 15 are directed to a table top having an edge with a height of about ¾ inch. The present invention, however, is not limited to these particular table sizes, and may comprise various dimensions to fit other size heights of table top edges.
[0036] As shown in FIGS. 2 through 15, the retainer of the present invention is somewhat similar in shape to conventional retainers (see FIG. 1). However, the retainer of the present invention includes certain features to overcome the disadvantages and limitations of conventional retainers. As shown in FIGS. 2 through 8, retainer 10 of the present invention includes a primary planar member 20 , an upper member 40 , and a lower member 60 . The primary member 20 is substantially square or rectangular in shape, and has an upper end 22 , a lower end 24 , a front surface 26 and a back surface 28 . The terms “upper,” “lower,” “front,” and “back” are relative to the table top to which a retainer is secured. Thus, when retainer 10 is secured to the table top, upper end 22 is positioned above lower end 24 , front surface 26 faces toward the table top, and back surface 28 faces the direction opposite front surface 26 , i.e., towards the table skirt. Primary member 20 also includes two substantially identical slots 30 , 32 , which extend upward from lower end 24 . Slots 30 , 32 define a section 34 of primary member 20 from which lower member 60 extends downward.
[0037] A hook portion 80 is positioned on back surface 28 of primary member 20 . Hook portion 80 preferably includes a plurality of hooks 82 of the hook and loop type fastener. Hooks 82 are generally positioned over a substantial portion of the area of back surface 28 of primary member 20 . In one embodiment, as shown in FIGS. 3 and 4, hooks 82 are positioned in three separate hook areas 84 , 86 , and 88 , with two hook-free areas 90 , 92 . In particular, hook-free area 90 is positioned between the hook areas 84 and 86 , while hook-free area 92 is positioned between hook areas 86 and 88 .
[0038] Upper member 40 of retainer 10 extends perpendicularly from primary member 20 at or near upper end 22 of primary member 20 , and is substantially horizontal. Upper member 40 extends outward from front surface 26 of primary member 20 , in the direction toward the table top (not shown) when retainer 10 is secured to a table top. Upper member 40 may comprise a wide variety of shapes and sizes, including, but not limited to, circular, half-circular, triangular, substantially triangular, bell-shaped, and the like. In the embodiment shown in FIGS. 2 through 8, upper member 40 is substantially triangular in shape, with a rounded front edge 42 .
[0039] As shown in FIGS. 2, 3 and 6 , lower member 60 is substantially U-shaped, beginning from section 34 , at the lower end of primary member 20 . The substantially U-shaped lower member 60 is comprised of a first leg 62 extending downward from section 34 , and a second leg 64 extending from leg 62 upward toward upper member 40 . First leg 62 slants downward from primary member 20 , and frontwardly, meaning in the same direction from the major plane of primary member 20 that upper member 40 extends, or more plainly, towards the table.
[0040] Upper end 66 of leg 64 of lower member 60 is spaced a distance below upper member 40 . In use, the retainer 10 is attached to the edge of a table top (not shown) by engaging the upper surface of the table top with upper member 40 and the lower surface of the table top with lower member 60 . More particularly, the upper surface of the table top engages with the lower surface 44 of upper member 40 , and the lower surface of the table top engages with upper end 66 of leg 64 of the lower member.
[0041] Upper end 66 of leg 64 preferably includes a chamfered portion 68 to help engage it with the lower surface of a table top. As shown in FIGS. 2, 3 and 6 , in one embodiment, portion 68 is curved or arc-shaped. Portion 68 is not limited to being curved, but may comprise any shape and size that aids in engaging the lower surface of a table top. As shown in FIG. 6, portion 68 is generally positioned directly beneath front edge 42 of upper member 40 . Preferably, portion 68 does not extend beyond front edge 42 . In addition, preferably, an engagement surface 43 on upper member 40 is positioned directly below an engagement surface 65 on lower member 60 . This arrangement allows for the even distribution of pressure to the engagement surfaces, thereby preventing disengagement through slippage.
[0042] The distance d 1 between the upper surface of portion 68 and the lower surface of upper member 40 determines the particular table top to which a retainer may be secured. In particular, in the embodiment shown in FIGS. 2 through 8, the distance d 1 is about ⅜ inch and, thus, as stated above, retainer 10 may be secured to those tables having a table top with an edge height of about ⅜ inch.
[0043] As shown most clearly in FIGS. 2, 3 and 6 , legs 62 and 64 of lower member 60 are substantially the same length when measuring leg 62 from lower end 24 of primary member 20 to juncture 63 (bottom point) of legs 62 and 64 , and when measuring leg 64 from juncture 63 of legs 62 and 64 to curved portion 68 . In particular, legs 62 , 64 may be about 13 mm to about 30 mm in length. Legs 62 and 64 may also be a length of about 25.5 mm.
[0044] While legs 62 and 64 are preferably substantially the same length, leg 62 of the present invention is relatively long in comparison to conventional retainers. In addition, primary member 20 is preferably shorter in length (i.e., from lower end 24 to upper end 22 ) than conventional retainers. Because the length of leg 62 in the present invention is extended, the distance between lower end 24 of primary member 20 and the bottom of the U-shape of lower member 60 (i.e., juncture 63 ) is also greater. This greater distance results in greater flexibility for the retainer of the present invention. As stated above, the retainer must be sufficiently flexible in order to easily secure the retainer to a table top edge and to easily remove the retainer from the table top edge. Primary member 20 , as a square or rectangular member typically made of a plastic material, is otherwise rigid and relatively inflexible. Thus, the greater the relative length of leg 62 , the more flexible is retainer 10 .
[0045] In addition, the flexibility of retainer 10 of the present invention is enhanced because of the presence of two, preferably continuous slots 30 and 32 formed through primary member 20 . However, there could just as easily be one continuous slot. In particular, slots 30 and 32 define finger 31 and finger 33 of primary member 20 . Slots 30 and 32 are continuous from the interior of primary member 20 to a lower edge of primary member 20 so as to define the side edges of leg 62 . Fingers 31 and 33 generally correspond to hook areas 88 and 84 , respectively. Fingers 31 and 33 are useful because they enable primary member 20 to have a larger surface area for attachment of hook areas 88 and 84 , while providing retainer 20 with the same flexibility that a retainer would have if fingers 31 and 33 were severed at their upper end and removed. Moreover, leg 62 angles downward from primary member 20 in the direction towards the table top, and not towards the table skirt. This angle or slant of leg 62 is such that a table skirt secured to retainer 10 may lay flat in the downward direction, and will not slant outward from the table, as may occur with the conventional retainers previously discussed. Note that even a perfectly vertical primary member will still slant outward when the retainer is biased when capturing the edge of a table top.
[0046] The flexibility of lower member 60 is enhanced because of two radius portions present in lower member 60 . The first radius portion 77 is formed at the intersection of lower member 60 and primary member 40 . The second radius portion is at juncture 63 .
[0047] [0047]FIGS. 9 through 15 illustrate an alternative embodiment of the retainer of the present invention. This retainer is for securing to those table tops having an edge with a height of about ¾ inch. The retainer 10 ′ shown in FIGS. 9 through 15 is similar to retainer 10 shown in FIGS. 2 through 8. In particular, retainer 10 ′ includes a primary member 20 ′, an upper member 40 ′, a lower member 60 ' and a hook portion 80 ′.
[0048] Primary member 20 ′ includes an upper end 22 ′, a lower end 24 ′, a front surface 26 ′ and a back surface 28 ′, along with slots 30 ′, 32 ′ that extend upward from the lower end 24 ′. Slots 30 ′, 32 ′ define a section 34 ′ of primary member 20 ′ from which lower member 60 ′ extends. In addition, a hook portion 80 ′ is positioned over substantially the entire back surface 28 ′ of primary member 20 ′. Hook portion 80 ′ includes a plurality of hooks 82 ′ for engagement with loops of a hook and loop type fastener that are positioned on a table skirt. Preferably, hooks 82 ′ comprise three hook areas 84 ′, 86 ′ and 88 ′, with hook-free areas 90 ′, 92 ′ there between.
[0049] Upper member 40 ′ extends frontwardly, as previously defined, from upper end 22 ′, and is preferably perpendicular to the major plane of primary member 20 ′ when retainer 10 ′ is secured to the table. In this embodiment, as shown most clearly in FIGS. 9, 10 and 14 , upper member 40 ′ is bell-shaped with a rounded front edge 42 ′. Again, however, upper member 40 ′ may comprise a wide variety of shapes, as discussed above.
[0050] Lower member 60 ′ is substantially U-shaped, having two legs 62 ′ and 64 ′. The first leg 62 ′ extends in a serpentine pattern downward and frontwardly from primary member 20 ′, again, frontwardly meaning in the same direction from the major plane of primary member 20 ′ that upper member 40 ′ extends, or more plainly, towards the table about which the skirting is being secured.
[0051] Leg 64 ′ is preferably a substantially vertical member extending upward toward upper member 40 ′. In this embodiment, leg 62 ′ preferably includes a first bend 76 . An upper end 66 ′ of leg 64 ′ of lower member 60 ′ is spaced a distance below upper member 40 ′. In use, retainer 10 ′ is attached to the edge of a table top (not shown) by engaging the upper surface of the table top with upper member 40 ′ and the lower surface of the table top with lower member 60 ′. More particularly, the upper surface of the table top engages the lower surface 44 ′ of upper member 40 ′, and the lower surface of the table top engages upper end 66 ′ of leg 64 ′.
[0052] The lower surface of the table top engages portion 68 ′, as follows: Upper end 66 ′ of leg 64 ′ preferably includes a camming portion 68 ′ to more easily engage the lower surface of a table top. In this embodiment, as shown in FIGS. 9, 10 and 13 , portion 68 ′ is a substantially planar portion 70 including a top surface 72 that may have an outward curve 74 . Again, portion 68 ′ is not limited to having a curved surface, but may comprise any shape and size that aids in engaging the lower surface of a table top. As shown in FIG. 13, portion 68 ′ of upper end 66 ′ is generally positioned directly beneath front edge 42 ′ of upper member 40 ′. Preferably, curve 74 is directly below the middle of the bottom surface 44 ′ of upper member 40 ′. This allows for engagement of a flat surface, such as a table top, by curve 74 and surface 44 ′. These two points on the retainer members are in a substantially vertical axis, and prevent disengagement of the retainer due to slippage. In addition, preferably, an engagement surface 43 ′ on upper member 40 ′ is positioned directly above an engagement surface 65 ′ on lower member 60 ′.
[0053] Upper end 66 ′ of lower member 60 ′ is spaced a distance below upper member 40 ′, thereby defining a predetermined spacing d 1 between the upper and lower members 40 ′, and 60 ′, respectively. As with the previous embodiment, this distance d 1 ' determines the particular table top to which a retainer may be secured. In the embodiment shown in FIGS. 6 through 15, the distance d 1 is preferably about ¾ inch and, thus, this retainer may be secured to those tables having a table top with a height of about ¾ inch.
[0054] As shown most clearly in FIGS. 9, 10 and 13 , in this embodiment, legs 62 ′ and 64 ′ of lower member 60 ′ are substantially the same length when measuring leg 62 ′ from lower end 24 ′ of primary member 20 ′ to the juncture 63 ′ of legs 62 ′, 64 ′ and measuring leg 64 ′ from juncture 63 ′ of legs 62 ′, 64 ′ to the substantially planar portion 70 ′. In particular, legs 62 ′, 64 ′ may be about 13 mm to about 30 mm in length. In one embodiment, legs 62 ′, 64 ′ are about 22 mm in length.
[0055] As with the previous embodiment, leg 62 ′ of retainer 10 ′ is relatively long in comparison to conventional retainers. Also, primary member 20 ′ is preferably shorter in height (i.e., from lower end 24 ′ to upper end 22 ′) than conventional retainers. In addition, the flexibility of retainer 10 ′ of the present invention is enhanced because of the presence of slots 30 ′ and 32 ′ in primary member 20 ′. In particular, slots 30 ′ and 32 ′ define finger 31 ′ and finger 33 ′ of primary member 20 . Slots 30 ′ and 32 ′ are continuous from the interior of primary member 20 ′ to the lower edge of primary member 20 ′ so as to define the side edges of leg 62 .′ Fingers 31 ′ and 33 ′ generally correspond to hook areas 88 ′ and 84 '. Fingers 31 ′ and 33 ′ are useful because they enable primary member 20 ′ to have a larger surface area, due to the inclusion of hook areas 88 ′ and 84 ′, while providing retainer 20 ′ with the same flexibility that a retainer would have if fingers 31 ′ and 33 ′ were severed at their upper end and removed.
[0056] Moreover, as shown most clearly in FIGS. 9, 10 and 13 , leg 62 ′ slants in the direction toward the table when engagement surface 65 ′ is biased, as retainer 10 ′ is secured to a table edge. The presence of bend 76 in leg 62 ′ is preferred to ensure the structural integrity of lower member 60 ′ and to allow retainer 10 ′ to flex more readily. As discussed above, because leg 62 ′ slants towards the table when retainer 10 ′ is secured to a table, a table skirt attached to a plurality of retainers 10 ′ may lay flat in the downward direction, and will generally not lay at a slant outward from the table, as may occur with conventional retainers, as discussed above.
[0057] The flexibility of lower member 60 ′ is enhanced because of three radius portions present in S-shaped lower member 60 ′. The first, radius portion 77 ′ is formed at the juncture of lower member 60 ′ and primary member 20 ′. The second radius portion, bend 76 , essentially serves as a fulcrum point for retainer 10 ′. The third radius portion is at the bottom of the U-shaped lower member—i.e., at juncture 63 ′.
[0058] It is preferred that the retainer of the second embodiment also be fabricated using an extrudable plastic material such as polyolefin, polycarbonate, nylon, or the like. In addition, in both of the embodiments described above, the parts of the retainers are preferably made from a transparent plastic so that they can be discerned only upon close inspection. Such retainers thus do not draw attention away from the table skirt held in place around the edge of a table top. Preferably, polyolefin is used because of its flexibility and its transparent-like qualities. The hooks are preferably extruded from the same material as the primary member and are integral with the primary member. This avoids the time and cost of attaching a separate strip of material containing hooks to the back surface of the primary member. In the alternative, however, separate strips of hook-containing material may be used with this invention by attaching the separate strips, e.g., by adhesive, to the back surface of the primary member.
[0059] In both embodiments described above, the retainer may be attached to the edge of a table top by engaging the upper surface of the table top with the upper member and the lower surface of the table top with the lower member. Preferably, a plurality of retainers are first placed at intervals around the edge of one or more sides of the periphery of the table top such that the hook portion faces outward. For releasable engagement of the hook portion, the loop portion (not shown) is attached to the periphery of the table skirt (not shown) and includes a plurality of loops. To hang a table skirt from the table top, the table skirt is pressed against the individual retainers around one or more sides of the table. The table skirt is pressed against the individual retainers while aligning the loop portions of the table skirt to the hooking portions of the retainers. Pressing the loop portions of the table skirt against the hooking portions of the retainers allows the hooks and loops to engage and form mechanical bonds. Once it is desired to remove the table skirt, the mechanical bonds between the hooks on the retainers and the loops on the table skirt may be broken by peeling the loops from the hooks.
[0060] It will be apparent to those skilled in the art that various modifications and variations can be made in the method of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.
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A flexible retainer for securing a web-like material, such as a table skirt, to a flat surface or table. The retainer has a frontwardly extending upper member, a substantially U-shaped lower member having a frontwardly extending first leg, and a primary member connecting the upper member to the lower member. The structure of the retainer and the configuration of its elements help to mask its appearance when used to retain a table skirt. In addition, extending into the lower end of the primary member are one or more vertical slots, which define one or more fingers. The configuration of the slots serve to improve the flexibility of the retainer, while maintaining the primary member's surface area for disposition of fasteners.
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BACKGROUND OF THE INVENTION
This invention relates to flash suppression devices for firearm muzzles.
When a firearm is discharged, the propellant gases that were generated by the combustion of the propellant powder exit the muzzle in the wake of the projectile. This instantaneous discharge of hot propellant gas mixes vigorously with the ambient atmosphere, and certain chemical moieties in the propellant gases have a propensity to ignite by combining with atmospheric oxygen and producing a reaction which results in the release of a certain amount of energy. This energy release is accompanied by an increase in muzzle blast and the emittance of visible light. In conditions of low ambient light, e.g., at night, this flash not only discloses the location of the firer, but also destroys his night vision, especially if his eyesight had been accommodated to low light level prior to the discharge.
The jet of propellant gases also contributes materially to the recoil of the firearm, as the momentum of both projectile and propellant is imparted to the firearm. Because the velocity of the propellant gas jet is typically much higher than that of the projectile, the powder gases contribute a large fraction of the recoil energy to the firearm.
Prior art has repeatedly addressed the management of the energy of the escaping propellant gases. It has long been the practice for both small arms and cannon to equip the barrel with a muzzle brake which diverts part of the propellant gases rearward or at right angles to the muzzle exit, thus eliminating that portion of the recoil. Small arms, particularly assault rifles, submachine guns, and machine guns, are ordinarily equipped with muzzle devices intended to suppress the flash which would usually be expected upon discharge. On occasion, muzzle devices having the dual purpose of reducing both flash and recoil are fitted.
In the prior art, flash suppression has been sought in three different ways: (1) Chemical constituents are incorporated into the propellant powder so that the reaction between the powder gases and atmospheric oxygen is impeded; (2) A shroud is fitted to the muzzle to simply hide the flash; and (3) The powder gases are vented in such a way as to mix them with the atmosphere so that the conditions to initiate and support combustion are not attained. Method (1) is independent of the firearm, and most modern propellants incorporate a flash suppression additive.
In contrast, recoil reduction has always been addressed from the single approach of diverting the powder gases so that a smaller component of the recoil force is along the axis of the barrel.
It is an objective of this invention to eliminate the visible flash from the muzzle of a firearm when discharged in an environment of low ambient illumination. It is an additional objective to reduce to perceived recoil of weapons that incorporate this device, so that the effectiveness of the weapon is improved, as well as its controllability, in fully automatic fire.
It is another objective to accomplish this with a muzzle device which is similar in weight and bulk to those in contemporary usage.
SUMMARY OF THE INVENTION
The purpose of the expanding inner bore in the device is to present greatly varying wall pressure to the longitudinal slots, which are cut through the body of the device from its Exit Plane and communicate between the inner bore and the outside of the device. These slots, by regulating the venting of powder gases laterally out of the device, (1) break up and interfere with the formation of the otherwise symmetrical structure of the "shock bottle", and (2) create multiple reflections of the shock waves in the emerging propellant gases. These propellant gases are then presented to the atmosphere at an increased volume and a lower pressure. Conditions are thus created that when the gases are mixed with the atmospheric air, the temperatures are such that ignition cannot occur.
The processes by which the powder gases are introduced and mixed are essentially different from the processes taught by the prior art or the processes that occur when no muzzle device is fitted to the barrel.
THE DRAWINGS
FIG. 1 is a perspective view of the flash suppressor of the invention showing it attached to a barrel of a gun;
FIG. 2, a side elevational view of one embodiment of the flash suppressor;
FIG. 3, a side elevational sectional view of an embodiment of the flash suppressor;
FIG. 4, a side elevational sectional view of another embodiment of the flash suppressor;
FIG. 5, a side elevational sectional view of another embodiment of the flash suppressor;
FIG. 6, a side elevational sectional view of another embodiment of the flash suppressor;
FIG. 7, a side elevational sectional view of another embodiment of the flash suppressor;
FIG. 8, a side elevational sectional view of another embodiment of the flash suppressor;
FIG. 9, an end elevational view of an embodiment of the flash suppressor;
FIG. 10, an end elevational view of another embodiment of the flash suppressor;
FIG. 11, an end elevational view of another embodiment of the flash suppressor;
FIG. 12, an end elevational view of another embodiment of the flash suppressor;
FIG. 13, an end elevational view of another embodiment of the flash suppressor;
FIG. 14, an end elevational view of another embodiment of the flash suppressor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, as illustrated in FIGS. 1 and 2, an exit bore flash suppressor 1 of the invention is attached to the barrel 2 of a firearm by means of a threaded connection 3. A plurality of slots 4 extend from the barrel muzzle to the exit plane 5 of exit bore device 1. These slots total at least two, are parallel to the axis of the bore, and are preferably 6-9 times caliber length.
The exit bore device 1 reduces and eliminates flash by a combination of these two major parameters: the contour of the inner bore and the number, size and placement of the slots. The internal geometry of the exit bore device 1 is best illustrated by longitudinal section views (FIGS. 3, 4, 5, 6, 7, 8) and the slots are best shown by end views (FIGS. 9, 10, 11, 12, 13, 14).
FIGS. 3-8 depict several acceptable geometries of the inner bore 6. The devices have a threaded section 3 for attachment to a gun barrel 2 or a smooth bore. FIG. 3 shows an attachment whereby the base of the device 1 butts firmly against the muzzle 7. If the threads of the device and muzzle are not synchronized for the preferred slot orientation, the device must be rotated to accomplish this. FIG. 4 illustrates this case, and the gap 8 that results. It has been found that this has negligible effect on flash.
The device depicted in FIG. 3 approximates the optimal inner geometry of the exit bore device 1. Exit bore device 1 begins with a short cylindrical section 9 of approximately 1/2 caliber in length with an A/A* of 1.6. A/A* is defined as the area of the inner bore at a specific point divided by the area of the barrel bore. This short initial section 9 regulates the nature of the flash and is beneficial on some exit bores devices, dependent upon slot width and barrel length. However, it is not essential and has been omitted from FIGS. 5 and 6.
The main cylindrical section 10 follows next which can have an A/A* ratio from 2 to 4, but preferably about 2.6. A tapered section also known as an exit bore tapered section then extends to the exit plane 5 of the device. This exit bore tapered section preferably has an A/A* ratio of from about 4 to about 14.7 at the outward end. This taper is preferably uniform, but can be non-uniform and is from about 2 to about 10 degrees. The taper can also be from 6 to 10 degrees. Seven to nine degrees has been found to be the preferred range of exit bore taper sections with an A/A* at the exit plane of between 7 to 9.5.
The degree of taper and point of origination is important in reducing flash. Varying these dimensions determines wall pressure on the slots, which in turn determines how much gas is allowed to escape through the slots versus how much gas is directed forward. A proper balance must be achieved here. If too much gas escapes through the slots, flash will extend radially around the device. If too much gas is directed forward, a flash will be created in front of the device.
Similarly, the length of the slots determines how much gas is released through the slots versus that portion which is expelled forward. As the length of the slots increase, a greater percentage of the propellant gases exit through the slots, and the pressures in the inner bore decrease. This gradual introduction of these propellant gases to the atmosphere results in the gradual imparting of the momentum of these gases to the weapon and, hence, increased controllability in automatic fire.
FIG. 4 shows essentially the same structure as FIG. 3, except that the exit bore tapered section 11 consists of two intersecting tapers 12. It is further contemplated that a device could work with numerous tapers of increasing degree or a smoothly expanding curve. FIG. 5 illustrates a device with only the one main cylindrical section 10 which then enters into a uniform taper 13 of more gradual degree than illustrated in FIG. 3. FIG. 6 shows a device of even less taper 14 which originates at the muzzle and smoothly increases to the exit plane 5. FIG. 7 shows an exit bore of short cylindrical sections 15 of increasing diameters.
FIG. 8 depicts a device wherein the outer surface 16 of the end of device has a smaller diameter. The purpose here is to communicate from the inner bore to the atmosphere sooner.
FIGS. 9, 10, 11, 12, 13 and 14 illustrate end views of the exit bore devices with varying numbers and placement of slots. The innermost circle 17 represents the first short cylindrical section; the second circle 18 represents the main cylindrical section which then tapers outwardly to the exit plane or exit bore opening 19. The outermost circle 20 delineates the outside cylindrical shell. The slots originate from the main cylindrical section. The slot width may increase until such point that the slots expand the geometry of the inner bore. It has been found that a slot width which approaches the maximum allowable reduces flash most effectively due to an increased volume of correspondingly lower pressure gases being presented to the atmosphere.
FIG. 9 shows the preferred slot orientation for a four slotted device. The slots 21 are oriented in this fashion to conceal the primary flash that originates at the muzzle from an observer at the same elevation, and to reduce the amount of dust that is raised from the ground. In addition, any smoke from the slots will not obscure the line of sight of the shooter.
FIG. 10 illustrates an end view of a four slotted device except here, two opposing slots 22 are offset slightly from the centerline bore. The purpose of this arrangement is to change the natural acoustic frequency of the bars and reduce the ringing sound emitted.
FIG. 11 shows the preferred slot orientation for a three slotted 23 device with 120° spacing. This configuration reduces dust and conceals any primary flash.
FIG. 12 illustrates the uneven spacing of a three slotted device whereby one slot 24 is oriented in the vertical and the other two 25 are placed approximately 100° from the vertical. This orientation both reduces muzzle climb and flash by introducing even more asymmetry in the shock structure. FIG. 13 shows the even spacing of a six slotted device 26. Due to the multitude of slots orientation is not important with respect to concealability or dust.
FIG. 14 illustrates an end view of the device shown in FIG. 8. The dotted line 27 represents the smaller diameter of the outside shell of device. This arrangement results in the gases communicating with the atmosphere sooner.
More specifically, the following dimensions are for an exit bore device that has been optimized for the 5.56 MM military rifle cartridge. It is emphasized that these dimensions are not the only combination that will give satisfactory results; there are many such combinations that work well if the elements described above are incorporated. It is also emphasized that different cartridges, barrel lengths, gas regulatory systems, propellants, primers, and/or projectiles may require a different optimized geometry as noted herein.
EXAMPLE #1
Optimum Exit Bore
______________________________________Overall length 2.655 in.Exit bore length 2.060 in.Thread depth 0.595 in.Exit Bore diameter .359 in.Exit Bore taper 8 degreesDiameter of exit bore opening 0.610 in.Number of slots 4Width of slots 7/32 in.Total slot width 7/8 in1st cylindrical section 0.150 in. long 0.2812 in. diameterA/A* for main cylindrical section 2.56A/A* at exit plane of device 7.41______________________________________
A/A* is defined in the cross-sectional area of the inner bore at a specific location divided by the cross-sectional area of the barrel bore. Exit bore diameter is the diameter of the main cylindrical section.
However, experimentations have shown the variations around these dimensions have also proven workable. The following table shows the approximate limits of acceptable performance.
TABLE I______________________________________Exit bore length: 1.670 to 2.060 in.Exit bore diameter 0.348 to 0.391 in.Exit bore taper 2 to 10 degreesDiameter of exit bore opening .680 to .580 in.Number of slots 3 to 6Width of slots 3/16 to 5/16 in.Total slot width 9/16 to 11/8 in.______________________________________
More specifically, the following are examples of devices that have proven to be acceptable:
TABLE II______________________________________ 1 2 3______________________________________Exit bore length 2.060 in. 1.860 in. 1.670 in.Exit bore diameter .359 in. .359 in. .359 in.Exit bore taper 8° 8° 9°Number of slots 3 3 3Width of slots 3/16-1/4in. 1/4-5/16 in. 5/16 in.______________________________________ 4 5 6______________________________________Exit bore length 1.860 in. 1.860 in. 2.060 in.Exit bore diameter .359 in. 0.359 in. .359 in.Exit bore taper 4° 8° 2°Number of slots 3 3 6Width of slots 5/16 in. 5/16 in. 3/16 in.______________________________________
It is apparent from the above examples that as one deviates from the #1, the optimum #3 bar suppressor, the slot width or total slot width must be increased to produce acceptable results.
Other configurations include devices in which:
(A) said inner bore has, in sequence, an abrupt expansion section to a cylindrical section, a second abrupt expansion section to a cylindrical section, and followed by a uniform outward tapered to the exit plane of the device;
(B) said inner bore has in sequence an abrupt expansion section to a cylindrical secton and then followed by a uniform tapered section to the exit plane of the device;
(C) the first short cylindrical section is less than 2 calibers in length and has a ratio of approximately 1.6 for the cross-sectional area of the cylindrical section of the inner bore divided by the cross-sectional area of the barrel bore of the gun barrel;
(D) the outer surface of the outer end of said shell has a reduced diameter from the diameter of the opposite end;
(E) the center of said slots are non-intersecting with the extension of the bore axis;
(F) said slots are from 6 to 10 calibers in length;
(G) the device is made integral with the barrel;
(H) the slots are unevenly spaced;
(I) the inner bore has a non-uniform taper;
(J) the inner bore comprises a series of cylindrical sections of increasing diameter; and
(K) said slots originate ahead of the firearm barrel muzzle.
While this invention has been described and illustrated herein with respect to several preferred embodiments, it is understood that alternative embodiments and substantial equivalents are included within the scope of the invention as defined by the appended claims.
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The inventive device is composed of a cylindrical body with a specifically shaped expanding inner bore which is mounted on the barrel of the firearm. This expanding bore constantly increases from the interface with the muzzle of the firearm to the exit plane of the device. Longitudinal slots, parallel to the bore axis, are cut through the body of the device from the outside to the inner bore.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for releasing a fishing line and for retrieving a major portion thereof, when the line's terminal end is caught, snagged or is otherwise inaccessible to a person who is fishing.. The novel features and principles of the present invention while particularly applicable to the fishing art may be extended to other fields of art having a need for the retrieval of similarly situated cables, wires, ropes, optical fibers and the like.
2. Description of the Related Art
Eons ago, when some coastal caveman figured that there were more fish on or near the bottom than there were at the surface, he tied a rock to his primitive line and began to fish the depths of the oceans, lakes and other such bodies of water.
It is likely that this caveman had several size rocks and lines handy, in case the line and rock became lost in a struggle with a fish or to the bottom as a result of a hopeless snag. Indeed this later scenario is likely, in view of several ingeniously shaped stones, fashioned for fishing weights, that have been found among artifacts in waters proximate to ancient Inca and pre-Inca civilizations in South America. As civilization progressed through the passage of time, fishing weights and tackle were improved, but the basic problems associated with retrieving a line which has been snagged beneath a body of water still persist today.
Accordingly, it is a general proposition well recognized in the fishing art that most bodies of fishable waters are infested with ensnarling vegetation, debris, coral shipwrecks and other obstructions upon which hooks, lures, plugs and other tackle may, from time to time become embedded or snagged during the fishing process.
Traditionally accepted methods for releasing snagged fishing tackle include: cutting the line at the end nearest to the angler and taking one's losses; or the futile expenditure of time, patience and effort in an attempt to free the snagged lure and associated tackle. While this latter course of action is somewhat frustrating, it is the alternative which a great majority of anglers elect to take although it bears certain disadvantages, including the risk of loss or damage to a major portion of the snagged line.
More specifically, attempts at retrieving a snagged line often involve the relocation of the boat or angler to a location behind the point of ensnarement. Once so positioned, the angler exerts tension on the line by pulling and jerking the line. If the angler is lucky, the line and tackle will come free, otherwise the line breaks or remains snagged. More often than not, when the line cuts or breaks or comes free, it does so abruptly, which can be dangerous. In those instances where the line does come free it has often been twisted and stretched, thereby, reducing its strength and utility for further fishing.
A further disadvantage of pulling and jerking the line is that the angler has no control of where the line will break, if it indeed breaks at all. If the line breaks near the angler, then the angler would have been better off to have cut the line,either way, the angler looses out. Even more importantly, the environment ultimately suffers as a result of the lost line. More particularly, fishing line, which is normally composed of nylon monofilament degrades quite slowly and the tangle of the line stripped off a reel clutters fishing grounds for years. This lost line has the disadvantage of creating an eyesore and a nuisance which can foul up a fishing area and provide a lethal trap for birds, fish and other wildlife.
Many devices have heretofore, been devised in order to retrieve line lures, hooks, plugs, and associated tackle. These devices have been comprised of various geometric configurations, sizes and clamping means to fasten to the fishing line. Many, if not all of these devices have met with only limited degrees of success. By and large, they have been impractical or unsatisfactory because their weight, size and/or complexity made them to cumbersome to store and handle in an ordinary tackle box. Additionally, many of the related art devices were difficult and time consuming to apply and release as well as being generally inefficient for their intended purpose.
Exposed cutting surfaces on some related art devices further complicated use by compromising user safety for functional design inadequacy. More often than not anglers, not only experienced the unnecessary loss of valuable fishing line and tackle but also incurred loss of the lure retriever as well. On some occasions the cost of a lost retrieving device was far in excess of the lost lure and associated tackle.
Experience indicated that the majority of these related art devices were often incapable of rendering the desired performance because of inadequate design, complexity of component parts, operator error or simple ineffectiveness. Oftentimes, these devices were not free to travel in tight spaces, lacked mobility, and became entangled upon their control lines, utilized unreliable dissolving tabltts to control their mechanisms, and/or required a multiplicity of hands to be applied, operated and released.
To further complicate matters, many related art devices were overly aggressive in their goals, attempting to recover both the line and the associated tackle connected thereto. While these goals are admirable it is not yet believed that this can be done reliably under constantly changing and therefore unknown conditions.
More exactly, the major failing of these all encompassing retrieving devices is that they assume a particular condition of ensnarement and generally are specifically designed for retrieval under such a given situation. In practice, however, an angler is generally unaware of exactly what circumstances have caused the line and associated tackle to become snagged. Accordingly, an angler would not know which prior art device to use in a given situation. Guess work led to frustration and losses of both the line and retrievers.
From the foregoing, the need should be appreciated for a safe to use, environmentally beneficial, small, reusable, inexpensive, reliable and easy to handle line saving device that operates effectively under myriad situations. Accordingly, a fuller understanding of the invention may be obtained by referring to the SUMMARY OF THE INVENTION, and the DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT, in addition to the scope of the invention as defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
This invention resides in certain novel features of construction, combination and arrangement of elements and portions as will hereinafter be described with specificity in the detailed description of the preferred embodiments, as particularly pointed out in the appended claims, and illustrated in the accompanying drawings.
For the purpose of summarizing the invention, the invention comprises a line retrieving apparatus and method. In its preferred form the apparatus includes a hollow, streamlined, bifrucated body member, a line guide means, a line clamping means, a line cutting means and a triggering means. The line clamping means, line cutting means and triggering means are supported and disposed inside of the aforementioned body member. The line guide means is integrally formed as part of the bifrucated body member.
In actual use, when an angler encounters a snag, he or she positions themself as near as possible to a point over the snag. Once so positioned, slack is taken up in the snagged line and the triggering means disposed with the body member is armed by the inward compression of both ends of the bifrucated body member. Once armed, the body member is then placed on the snagged line, via the line guide means.
The line guide means functions to support a snagged line in a manner so as to permit vertical movement of the body member along a snagged liee to the vicinity of a hook, swivel, weight, or the like which is snagged or otherwise unretrievable from a body of water. Not only does the line guide means permit the aforementioned vertical movement but it also automatically positions the snagged line in a desired position, inside the body member, with respect to the line clamping, line cutting and triggering means.
Once the apparatus has been so placed on the line, it is released and allowed to descend via gravity to a location proximate to the ensnarement. The angler then moderately tugs the snagged line, thereby, initiating the triggering means. Once triggered, the line is clamped by the line clamping means and almost instanaaneously the line comes into contact with the line cutting means. A subsequent, second tug or a continued pull on the snagged line cuts the line, freeing it from its ensnarement allowing the angler to retrieve a major portion of the snagged line along with the device, both for subsequent reuse.
It is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the related art methods and devices while providing a significant contribution to the advancement of the art.
Another object of this invention is to provide a device and method for the purposes of retrieving the line portion only of a fishing line which has become entangled with submerged rocks, coral, roots or the like at a point distant from the angler, hereinafter referred to as "Expected Purposes".
It is yet another object of the instant invention to provide an inexpensive device which has no objetionable characteristics, but which has the essential features of compactness.
It is an advantage of the instant invention to provide a device simple in construction and operation which is efficient, lightweight, reusable and durable for the purpose of retrieving the major portion of an ensnarled line in a quick, easy and rliable manner.
It is an object of the subject invention is to provide a reliable device and method for severing a line proximate to the point of ensnarement so that the device itself may be retrieved along with a major portion of line, for inspection repair and subsequent reuse.
Still another object of the present invention is to provide a device having a dependable service life which can be utilized in frequent applications of the same device without necessitating the purchase of new devices except in cases of extended use, abuse or unavoidable accident.
It is an advantage of this invention to provide a device for the "Expected Purposes" which does not require special tools, procedures, mechanical skills, aptitudes or abilities to apply and practice.
It is a feature of the instant apparatus to provide a hydro-dynamically shaped device for the "Expected Purposes" which enhances its descent and retrieval through varying under water currents and debris.
It is also a feature of the present invention to provide a device for the "Expected Purposes" that has a mass great enough to sink but that will not exert an undue stress on terminal tackle and the like.
It is an object of this invention to provide an apparatus and method that accomplishes the "Expected Purposes" which utilizes the snagged line itself for the control and retrieval of the device, thereby eliminating the need for separate control lines, dissolving tablets and the like.
Yet another object of this invention is to provide a device for the "Expected Purposes" which reduces the possibility of loss by automaticall preventing loading onto a snagged line unless such invention is properly armed.
Yet, another advantage of this invention is to provide a device for the "Expected Purposes" which is safe to use by providing a totally enclosed line cutting mechanism.
A further feature of the invention is to provide a device for the "Expected Purposes" that avoids excess pulling and stretching of ensnarled lines, thereby not damaging the line and accordingly, avoiding abrupt breakage and corresponding accidents.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the present invention will become apparent as the following DESCRIPTION OF THE PREFERRED EMBODIMENT proceeds taken inconjunction with the accompanying drawings in which:
FIG. 1 is a perspectvve view of a preferred embodiment of the retrieving device being lowered along a snagged line toward the point of ensnarement.
FIG. 2 is a perspective view of a preferred embodiment of the invention illustrated in an unarmed/uncompressed condition.
FIG. 2a is a front elevational view of the invention illustrated in FIG. 2.
FIG. 2b is a right elevational view of the invention illustrated in FIG. 2.
FIG. 2c is a rear elevational view of the invention as illustrated in FIG. 2.
FIG. 2d is a left side elevational view of the invention as illustrated in FIG. 2.
FIG. 2e is a rear elevational view of the invention illustrated in FIG. 2, but shown in a separated state.
FIG. 3 is a perspective view of a preferred embodiment of the invention illustrated in an armed/compressed position. This figure additionally shows a portion of a line inserted within the retrieving device.
FIG. 3a is a front elevational view of the invention illustrated in FIG. 3.
FIG. 3b is a right side elevational view of the invention illustated in FIG. 3.
FIG. 3c is a rear elevational view of the invention illustraed in FIG. 3.
FIG. 3d i a left side elevational view of the invention illustrated in FIG. 3.
FIG. 4 is a bottom plan view of the invention as illustrated in FIGS. 2 and 3. (Note: line insertion not illustrated)
FIG. 5 is a top plan view of the invention as illustrated in FIGS. 2 and 3. (Note: line insertion not illustrated)
FIG. 6 is a perspective, partially sectioned view of the invention illustrating a line guide means of the preferred embodiment of the invention.
FIG. 6a is a diagramatic functional illustration of line guides 44 and 46 as shown in FIG. 6.
FIG. 7 is a longitudal cross-section taken along line 7--7 of FIG. 2.
FIG. 8 is a longitudal cross-section taken along line 8--8 of FIG. 3.
FIG. 9 is a transitional, longitudal, cross-sectional view of a preferred embodiment of the invention taken along line 8--8 of FIG. 3 illustrating the clamping and severing of a line.
FIG. 10 is an enlarged perspective view of a trigger assembly utilized in a preferred embodiment of the invention.
FIG. 11 is an enlarged prospective view of a cam utilized in a preferred embodiment of the invention.
FIG. 12 is an enlarged perspective view of the internal line guide 86 utilized in a preferred embodiment of the invention.
FIG. 13 is a sectional view taken along line 12--12 of FIG. 11, illustrating a coarse cam surface.
FIG. 14 is another sectional view similar to that taken along line 12--12 of FIG. 11 illustrating a grooved surface embodiment of the cam as illustrated in FIG. 11.
FIG. 15 is a cross-sectional view taken along line 15--15 of FIG. 7.
FIG. 16 is a cross-sectional view taken along line 16--16 of FIG. 7.
FIG. 17 is a cross-sectional view taken along line 17--17 of FIG. 7.
FIG. 18 is a cross-sectional view taken along line 18--18 of FIG. 7.
FIG. 19 is a partial cross-sectional view taken along line 19--19 of FIG. 7.
FIG. 20 is a perspective view of a roll pin use with a preferred embodiment of the invention.
Similar reference characters and numerals refer to similar parts throughout the several views of the drawings.
DRAWING REFERENCE NUMERALS:
10 Line retrieving apparatus
12 angler
14 point of fishing line 20 ensnarement
15 underwater debris
16 body of water
17 boat
18 surface of 16
20 fishing line
22 contoured leading edge of 30
24 contoured middle surface of 28
26 contoured trailing edge of 28
28 upper assembly of 10
30 lower assembly of 10
32 line channel of 28
34 line channel of 30
36 reference point illustrating alignment of channels 32 and 34
38 reference point illustrating non-alignment of channels 32 and 34
40 lower casing of 30
42 upper casing of 28
44 line guide of 28
46 line guide of 30
48 concentrically aligned guide hole of 46
50 concentrically aligned guide hole of 44
51 semicircular member of 46
52 semicircular member of 46
53 semicircular member of 44
54 semicircular member of 44
56 cutout of 44
57 cutout of 44
58 cutout of 46
59 cutout of 46
60 severed terminal portion of 20
62 trigger pivot arm of 80
64 shank portion of 80
66 top end of 64
68 inside surface of 42
70 longitudal axis of 10
72 trigger assembly
74 cam assembly
76 line cutting assembly
78 trigger spring of 72
80 trigger lever of 72
81 lower end portion of 64
82 left cam of 74
84 right cam of 74
86 line positioning arm
88 reference point to windings of trigger spring 78
90 foot portion of 80
92 end portion of 78
93 trigger spring retention slot of 42
94 casing grip portion of 78
98 V groove of 80
100 longitudinal axis of 62
101 vertical axis of 80
102 blade
104 cutting surface of 102
106 longitudinal axis of 64
108 trigger stop 108
110 left cam positioning rib of 40
112 right cam positioning rib of 40
114 leading edge of 40
116 cam spring of 74
118 reference numeral illustrating cutting of line 20
120 arrow indicating direction of force on line 20
122 first body rib of 42
124 second body rib of 42
126 cam retaining rings
128 retention ring of 86
130 cam ledge 130 of 42
132 cam pin of 84
134 cam pin of 82
136 cam arm of 8
138 cam arm of 84
140 cam post of 84
142 cam post of 82
144 mounting plate of 86
146 hole of 144
148 left cam pin fitting hole of 82
152 support rib for 102
154 support rib for 102
156 protrusion of 152
158 protrusion of 154
160 compression spring of 28
162 spring cavity of 42
164 roll pin hole of 42
166 roll pin hole of 130
168 roll pin cutout of 40
170 roll pin
172 weight
174 cam washers
176 support ribs of 130
178 mounting holes of 82
179 mounting holes of 82
180 ramped surface for 80
182 gritty cam surface
184 grooved errated cam surface
190 heads of fastening screws for 116
192 bevelled surface of 90
DESCRIPTION OF THE PREFERRED EMBODIMENT
The use of a preferred embodiment of the invention will be explored initially as a backdrop for an improved understanding of the invention which follows. Accordingly, referring to the drawings and particularly to FIG. 1, there is shown a perspective view of the invention 10 being utilized by an angler 12.
The invention 10 is illustrated in four representative physical positions A, B, C and D with respect to the angler 12 and with respect to the poit of ensnarement 14 of the fishing line 20. Positions B, C and D of the device 10 are illustrated in phantom to depict the movement of the device 10 through the water 16.
The scene portrayed by FIG. 1 is an all to common one where the angler 12 has snagged a line 20 on some type of underwater debris 55. When line 20 has become snagged, angler 12 relocates the boat 17 to a point as close as possible over the point of ensnarement 14. Next, the angler arms the invention 10 by compressing the invention 10 inwaddly from each of its ends. A complete discussion of the mechanics of arming and placing the dvice 10 onto a fishing line will be eplored infra.
Once the invention 10 has been armed, the angler 12 then takes up any slack in the snagged line 20 and places invention 10 onto the snagged line 20. A complete discussion of such placement will also follow infra. Position A illustrates angler 12 placing invention 10 onto fishing line 20.
Once the invention 10 has been placed on the fishing line 20, the angler 12 releases the invention 10. The invention 10 then descends, via the force of gravity down fishing line 20, through the water 16 to the point of ensnarement 14.
As previously mentioned, the travel of the device 10 down fishing line 20 is illustrated, in FIG. 1, at four representative positions A, B, C and D. Position A represents the point of release of the device 10 by the angler 12. The angler 12 is shown using the invention 10 from a boat 17. It is to be appreciated that the device 10 may be used from any number of locations including but not limited to bridges, piers, cliffs and the like, wtthout affecting the operation and function of the invention 10.
The point of contact of the device 10 with the surface 18 of the water 16 is illustrated at position B of FIG. 1. It is at this point in which the device 10 penetrates the surface 18 of the water 16 along its travel to the ensnarement 14.
Referring now to FIGS. 1-4, it can be appreciated that the contoured shape of the leading edge 22 of the device 10 allows for the ease of entry into the water 16 and especially functions to reduce the force of impact of device 10 with the surface 18 of the water 16. This cushioning effect is especially important when the device 10 is released at great distances above the surface 18 of the water 16, such as from a bridge or fishing pier as previously mentioned. It is noted that contoured surfaces 24 and 26 (see FIGS. 2-5) are also hydrodynamically shaped to further enhance the movement of device 10 down through the water 16 to the point of ensnarement 14 and backup through the water 16 to the surface 18.
Position C, in FIG. 1, depicts the device 10 as being somewhere halfway between the surface 18 of the water 16 an the ensnarement 14. It is at this position C where underwater currents and debris are typically but not always present. The hydrodynamic shape of the device 10 not only functions to reduce the impact of the device 10 with surface 18 but also is helpful in penetrating semi-boyant, subsurface floating seaweed layers, debris and the like. More particularly the shape of device 10 reduces the likelihood of snags or hangpps. Furthermore, the hydrodynamically shaped device 10 ameliorates the effect of underwater currents on th decent and ascent of the device 10. It is also apparent from FIG. 1, position C, that trapped air within the device 10 escapes upon the device 10's descent, thereby reducing the buoyancy of device 10, which further facilitates the descent of device 10.
After a period of time, as judged by the experience of the angler, the device 10 will travel to and reach the point of ensnarement 14. The length of time required for the completion of the device 10's travel is dependent upon the depth of the ensnarement 14 with respect to the surface 18 of the body of water 16 and upon other environmental variables such as water current strength. It is noted, however, that the time for decent of the device 10 to the point of ensnarement is generally no greater than two (2) minutes.
After the device 10 has traveled to position D, as shown in FIG. 1, the angler 12 lightly tugs and maintains tension on the snagged fishing line 20. This force or tug is typically no greater than five (5) lbs. The angler's 12 tugging on the snagged line 20 functions to trigger or otherwise active device 10. Once triggered, the device 10, aided by the tension forces placed on the line 20, clamps and severs the fishing line 20.
Upon completion of the aforementioned clamping and cutting of line 20 the angler 12 will experience a noticeable relaxation in the tension of the snagged fishing line 20. At this juncture, the major portion of the fishing line 20 along with the device 10 may be reeled in or otherwise retrieved. Once the major portion of the fishing line 20 has been recovered along with device 10, the device 10 is removed from the terminal end of the severed fishing line 20, so that the device 10 may be stored and used again when needed.
It is to be appreciated that the use of the invention 10 just described is just one example of an application of the invention 10. Other embodiments, using the principles and teachings of the invention 10, may be extended to several applications including oil drilling, exploration and to the retrieval of ship anchors and the like. Indeed, the principles and teachings of the instant invention 10, may be employed for the retrieval of cables, wires, ropes, bouyline, diving markers, optical fibers and other similar materials. The teachings of this invention may also be extended to use in outerppace or to other environments where an absence of gravity exists.
Now that an exemplary use of the invention 10 has been described the mechanism, structure and mechanics of operation of a preferred embodiment of the invention 10 will be explored. FIGS. 2, 2-a2d illustrate various views of the invention 10 in an unarmed/uncompressed condition. The invention 10 as illustrated in FIG. 2 comprises an upper assembly 28 and a lower assembly 30. The lower assembly 30 has an outside diameter slightly smaller than the inside diameter of the upper assembly 28. This structure, allows the lower assembly 30 to loosely fit within the upper assembly 28, thereby forming a hollow body member which houses the mechanisss of the invention 10.
The preferred embodiment of invention 10 is designed to accommodate a fishing line only when the device 10 is placed into an armed/compressed position as those in FIG. 3 and FIGS. 3a-3d. More particularly, line channels 32 and 34 come into alignment with each other when the lower assembly 30 slides inwardly into the upper assembly 28. This alignment is specifically shown by reference numeral 36 in FIGS. 3 and 3a.
When the invention 10 is an unarmed/uncompressed condition as best shown in FIGS. 2 and 2a, channels 32 and 34 are out of alignment. When channels 32 and 34 are out of alignment the device 10 cannot be loaded onto a line. Reference numeral 38 in FIGS. 2 and 2a specifically illustrates this aforementioned non-alignment of the line channels 32 and 34. The alignment/non-alignment feature ensures that the device 10 is armed prior to its use, thereby avoiding accidental loss due to misuse of device 10 by the operator.
The line channels 32 and 34 are constructed and formed as an integral part of the invention 10 casings 40 and 42. The positioning of the line channels 32 and 34 insures that during the placement of the device 10 onto any given snagged line 20 that line 20 is positioned correctly with respect to the invention 10's internal mechanisms, such mechanisms to be described in detail infra.
The configuration of the line channels 32 and 34 may be more fully appreciated by reference to FIG. 2 and FIGS. 2a-2d. These figures illustrate line channels 32 and 34 as they extend in a circulate fashion between line guide members 44 and 46 respectively. The rationale and functionality for the positioning of channels 32 and 34 will become apparent, infra, as the detailed description focuses on the internal mechanisms of the device 10.
FIG. 6 is a perspective, partially sectioned view of the invention 10, illustrating in particular line guides 44 and 46. These line guides are integrally formed as a part of the upper and lower portions of casings 42 and 40 respectively. This one piece, integral construction eliminates additional parts and reduces manufacturing cost and reduces the possibility of snags or hang ups which often result when separately attached line guide mechanisms are used.
Line guides 44 and 46 operate in conjunction with each other to slideably support and maintain the invention 10 on a line. This support is accomplished by the concentric alignment of guide holes 48 and 50 along the longitudinal axis 70 of invention 10. More specifically, guide holes 48 and 50 are formed as a result of the spacing and construction of semi-circular members 53, 54 and 51, 52 respectively.
This spacing and construction of line guides 44 and 46 is best appreciated by reference to FIG. 6 in conjunction with FIG. 6a. FIG. 6a diagramatically illustrates the functional structure of line guides 44 and 46 respectfully. As can be seen in these figures, guide holes 48 and 50 are formed by the spacial intersection of cut outs 56, 57 an 58, 59 in semiccircular members 53, 54 and 51, 52 respectively.
More particularly, members 51 and 52, as are members 53 and 54, are spaced apart from and parallel to each other (this spacing is clearly shown in FIG. 6). The spacing between members 51 and 52 and between 53 and 54, respectively, is preferably 0.16 inches, or at least as far apart as the diameter of the thickest line contemplated to be recovered with any particular embodiment of the invention 10. In other words, the distance between members 51 and 52 and between 53 and 54 respectfully, must at least wide enough to accommodate loading of the device 10 on to a snagged line to be retrieved. Member 54 is spaced parallel and beneath member 53. Member 51 is similarly situated beneath member 52.
Upon further inspection of FIGS. 6 and 6a it can be seen that semi-circular member 53 is slotted by cutout 56. Cutout 56 extends from the periphery of semi-circular member 53 inward to the longitudinal axis 70. Similarly, cutout 57 (shown in phantom lines) extends inwardly from the periphery of semi-circular member 54 to the longitudinal axis 70. The intersection of the cutouts 56 and 57 in the spacially separated semi-circular members 53 and 54 form guide hole 50. Cutouts 56 and 57 are preferably oriented 180 degrees with respect to each other, and 90 degrees with respect to the longitudinal axis 70.
The configuration and formation of guide hole 48 of line guide 46 is likewise realized by cutouts 58 and 59. Of particular import is the reversed orientation of cutouts 56 and 58, and of cutouts 54 and 59. This orientation is preferred for enhanced stabilization of the device 10 onto the line 20.
Turning now to FIG. 7, a lngitudinal cross-section of the invention 10 taken along line 7--7 of FIG. 2 can be seen. This longitudinal cross-section illustrates a preferred embodiment of the invention 10 in an unarmed/uncompressed condition. From this view a majority of the internal mechanisms of the invention 10 may be fully appreciated. An inspection of FIG. 7 reveals trigger assembly 72, cam assembly 74 and a line cutting assembly 76.
The trigger assembly 72, cam assembly 74 and line cutting assembly 76 work in concert with each other to effect the invention 10's intended purposes. This coordinated action can be better appreciated as each respective assembly is further described herein.
Accordingly, the trigger assembly 72 further comprises a trigger spring 78 and a trigger lever 80. FIG. 10 illustrates an enlarged perspective view of the trigger lever 80. It may be appreciated from this figure that the trigger lever 80 comprises a V-groove 98 and a trigger foot portion 90. Also shown is a trigger pivot arm 62. The trigger lever 80 is preferably formed as sown in FIG. 10. More exactly, the shank portion 64 is formed approximately 20° degrees with respect to the axis 101. The vertical length of shank portion 64 is selected so as to leave approximately 0.10 inch clearance between the top end 66 of the trigger lever 80 and the inside surface 68 (see FIG. 7) of upper casing 42. As previously mentioned, the shank portion 64, is further formed into a V-groove 98 at the top at the top end 66 of shank 64. The V-groove 98 functions to maintain a line 20 on the trigger lever 80, during loading of device 10 onto a line 20 and during device 10's operation.
The lower end portion 81 of the shank portion 64 is characterized by an inward and then an outward bend. This configuration facilitates the positioning of V-groove 98 just below line channel 32. The aforementioned inward bend is typically formed parallel to axis 100 (shown in pantom lines in FIG. 10) and then protrudes outwardly as shown along axis 106 (also shown in phantom in FIG. 10), perpendicular to or 90° degrees with respect to axis 100. The shank portion 64 takes one more, bend as shown in FIG. 10, downward and parallel to axis 101, and 90° degrees with respect to axis 106. This latter bend formation is referred to herein as the trigger foot portion 90.
A trigger pivot arm 62, as shown in FIG. 10 positioned along axis 100, is affixed to shank portion 64, perpendicular to axis 106 and to axis 101. Pivot arm 62 not only functions to pivotally maintain the trigger lever 80 in place with the upper casing 42 (see FIG. 7) but also serves to support a trigger spring 78 (Also, see FIG. 7).
Reference is now made to FIG. 10 in conjunction with FIG. 15 so that a more complete appreciation of the construction and positioning of trigger assembly 72 within upper casing 42 may be had. FIG. 15 is a cross-sectional view taken along line 15--15 of FIG. 7, illustrating such positioning. V-groove 98 is clearly shown positioned just beneath the (opening) line channel 32 and inside surface 68 of upper casing 42. Trigger pivot arm 62 is shown inserted and held in place by body ribs 122 and 124. Body ribs 122 and 124 are preferably molded as an integral part of the upper casing 42. Such integral molding reduces the total number of parts, assembly time and increases strength and stability of body ribs 122 and 124.
Trigger spring 78 is shown in FIG. 15 coiled about pivot arm 62 at the point shown by reference number 88. Spring end portion 92 is shown engaged about shank portion 64. The casing grip portion 94 of trigger spring 78 is maintained in trigger spring retention slot 93 (retention slot 93 best shown in FIGS. 7-9). The trigger spring retention slot 93 is essentially a small cut out portion in the upper casing 42 which can also be visualized with reference to FIGS. 2d and 3d. It may be appreciated further from these later figures that the casing grip portion 94 fits flush with and does not protrude out from casing 42.
The aforementioned positioning of the casing grip portion 94 maintains trigger lever 80 in place within body ribs 122 and 124. The number of turns in trigger spring 78 at point 88 in conjunction with the gauge of the wire, comprising trigger spring 78 determines th force required to be applied by angler 12 to a snagged line in order to activate/trigger the device. Experience has shown that approximately five (5) lbs. of force is desirable. The mechanics of such activation/triggering will be described infra.
Reference is now made to FIG. 7 and 11 for the appreciation of the cam assembly 74. FIG. 11 is an enlarged perspective view of left cam 82. The primary components of cam assembly 74 comprise a left cam 82, right cam 84, line guide arm 86 and cam spring 116. Each cam's construction is essentially a mirror image of the other.
Cam 82 and 84 are further characterized by cam arms 136 and 138 respectively. Briefly, these cam arms cooperate with cam positioning ribs 110 and 112 during arming of the device 10 to spread apart cams 82 and 84.
More specifically, as alluded to above it must be appreciated that the basic structure of cam 82 as illustrated in FIGS. 7 and 11 is identical to the structure of right cam 84. This symmetrical construction reduces costly tooling and simplifies assembly of the device 10. This is because the symmetrical cam design allows for the interchangeability of the cams during assembly. During assembly of device 10, however, only one of the cams, i.e., the right cam 84 is assembled with a line positioning arm 86. The assembly of the right cam 84 is accomplished by the placement and fixation of internal line guide 86 onto the right cam 84 via cam post 140.
Reference is now made to FIG. 12, in addition to FIGS. 11 and 7, to further clarify the preferred construction of line positioning arm 86. FIG. 12 is an enlarged perspective view of line positioning arm 86 utilized in a preferred embodiment of the invention 10. The line positioning arm 86 is preferably formed out of a stiff wire (bent as shown) in FIG. 12. Such wire is secured to plate 144 by means well known in the art. Hole 146 in mounting plate 144 is specificaly designed for the placement of line positioning arm 86 onto right cam 84 (see FIG. 7). The fixation of plate 144 to the right cam 84 is preferably accomplished via the use of a retention ring 128 (as best shown in FIG. 8), which fits around post 140, snugly against mounting plate 144. Cam post 142 of the left cam 82 remains unused.
Further inspection of cam 82, in FIG. 11, reveals cam pin fitting hole 148, which penetrates the width of cam 82. This penetration may be appreciated by the hidden lines in FIG. 11. Right cam 84 has a similar cam pin fitting hole (not shown). Left cam pin fitting hole 148 and its identical counter part in the right cam 84 allow for the placement of the cam assembly 74 on or about cam pins 132 and 134 respectively.
More particularly, cam pins 132 and 144 protrude from cam ledge 130 as shown in FIGS. 7 and 17. The cam pins 132 and 134 are preferably ultrasonically affixed to said cam ledge 130. However, gluing, screw attachment, or the like are acceptable alternative means of construction fully within the spirit and scope of this invention. It is also noted that cam pins 132 and 134 are long enough to provide for adequate insertion within cam ledge 130 while being long enough to protrude slightly above cams 82 and 84. The slight protrusions allow for the placement of retaining rings 126 on to cam pins 132 and 134, over installed cams 82 and 84, to loosely but affirmatively maintain cams 82 and 84 on cam pins 134 and 132 respectively. Cam washers 174, as shown in FIG. 17, can be used to reduce friction between cams 82 and 84 and cam ledge 130, thereby enhancing the cams freedom of movement. Support ribs 176 add strength and butress cam ledge 130 against the forces exerted thereupon by cams 82 and 84 during clamping and cutting.
Returning now, to FIG. 11 it can be seen that left cam 82 further comprises mounting holes 178 and 179. Similar mounting holes (not shown) are provided in the symetrically constructed right cam 84. The mounting holes do not completely penetrate the left cam 82 or the right cam 84 but rather penetrate each cam approximately one-quarter (1/4) of the width of each respective cam. This may be visualized by reference to FIG. 11, wherein dotted lines illustrate the relative depth of penetration of mounting holes 178 and 179. Again the symmetrical construction of the cams facilitates the interchangeability of the cams during assembly and reduces the requirement for additional tooling.
Monting holes 178 or 179 are used for securing the cam spring 116 between the cams 82 and 84. This securement may be best appreciated by reference to FIG. 17. FIG. 17 is a cross-sectional view taken along line 17--17 of FIG. 7. Typically, a screw is used to secure the ends of cam spring 116 to each of the cams 82 and 84 respectively. The end portions of the spring 116 (end portions not shown) are preferably circularly looped in shape so that the head 190 of each fastening screws are of sufficient diameter so as to affirmatively clamp the circular end portions of the cam spring 116 to the cams.
Reference is now made to FIGS. 7 and 18 for discussion of the line cutting assembly 76. FIG. 18 is a cross-sectional view taken along line 18--18 of FIG. 7 illustrating the line cutting assebbly 76. Line cutting assembly 76 comprises a blade 102 and support ribs 152 and 154. Blade 10 is preferably a single edged blade formed out of stainless steel to reduce rusting and concomitant dulling of blade cutting surface 104. Blade 102 has two mounting holes therein (not specifically shown) for the mounting of blade 102 onto protrusions 156 and 158 of support ribs 152 and 154 respectively. It is noted that support ribs 152 and 154 are preferably formed as an integral part of the lower casing 40 of the invention 10.
During assembly the mounting holes of blade 102 are aligned with protrusions 156 and 158. Blade 102 is then placed down over the protrusions 156 and 158 so that the cutting surface 104 is positioned toward line channel 34. Once blade 102 has been so placed, protrusions 156 and 158 are preferably heat welded to secure blade 102 firmly against ribs 152 and 154.
Reference is now made to FIG. 2e to appreciate the joining of the upper and lower casings 42 and 40 respectively. FIG. 2e is a rear elevational view of the invention as illustrated in FIG. 2, but shown with upper assembly 28 separated from lower assembly 30. Once the trigger assembly 72, cam assembly 74 and line cutting assembly 76 are in place within their respective casings 40 and 42; then the upper and lower assembly 28 and 30 are joined together. The lower assembly 28 and 30 are joined by the lignment of lower casing 40 with upper casing 42 so that roll pin hole 164 in the upper casing 42 aligns with roll pin cutout 168 of the lower casing 40.
Once the aforementioned alignment is effected then the lower assembly 30 is inserted within the upper assembly 28. The inner diameter of casing 42 is large enough to accommodate the outer diameter of the casing 40. This configuration specifically facilitates the free sliding movement of assembly 30 within assembly 28.
The lower assembly 30 is then held in place with respect to the upper assembly 28 via a roll pin 170 as shown in FIG. 20, and FIGS. 7-9. More particularly, the joining of the upper assembly 28 and the lower assembly 30 is accomplished by inserting roll pin 170 through hole 164, and through cutout 168. Roll pin 170 also extends through a roll pin hole 166 of ledge 130 (as best shown in FIG. 16) to complete the joining of the upper and lower assemblies 28 and 30 respectively. It is noted that the roll pin cutout 168 allows for the movement of lower assembly 30 within the confines of upper assembly 28 so that cam assembly 74, trigger assembly 72, and line cutting assembly 76 will properly operate as now described.
Reference is now made to FIGS. 3 and 8 in order to more fully appreciate the operation of invention 10. FIG. 8 illustrates a longitudinal cross-section taken along line 8--8 of FIG. 3. As previously mentioned, FIG. 3 is a perspective view of a preferred embodiment of the invention, illustrated in an armed/compressed position. The armed/compressed position is the configuration in which the invention 10 is placed onto a snagged line to be retrieved.
The acts of an angler compressing the lower casing 40 into the upper casing 42 brings the ribs 110 and 112 into contact with cam arms 136 and 138 respectively. Continued compression by the angler causes ribs 110 and 112 to further interact with cam arms 136 and 138 to open cams 82 and 84.
The angler's compression stores energy in cam spring 116 and compression spring 160. More exactly, the movement of lower casing 40 into upper casing 42, causes the leading edge 114 of lower casing 40 to compress spring 160 into spring cavity 162. Compression spring 160 maintains tension on trigger assembly 72 and exerts a decompressing force on the upper end lower casings 42 ad 40 respectively. Cam spring 116 exerts a spring force on cams 82 and 84 urging such cams to close.
During compression, as lower casing 40 slides into upper casing 42, foot portion 90 of trigger lever 80 slides up a ramped surface 180 (see FIG. 19) and engages the lower casing via trigger stop 108. The slope of ramped surface 180 in conjunction with the bevelled portion 192 (see also FIG. 16) of foot 90 facilitate this sliding movement. Trigger stop 108 is preferably a circular hole which is positioned, as shown in FIG. 8, in lower casing 40. Trigger stop 108 does not protrude into the upper casing 42. The inner surface of upper casing 42 functions to add support to the trigger foot 90.
The combined fores stored in spring 160 and in the trigger spring 78 maintain device 10 in a compressed state for the use of device 10. This armed/compressed state is apparent in FIG. 8 by making reference to the visible compression of spring 160 and by the opened position of cams 82 and 84.
The armed device 10 is placed onto line 20 by manipulating device 10 so that line 20 enters the device through line guide 44 and through line channels 32 and 34, and so that the line 20 exits the device through line guide 46. Hence, device 10 is circularly manipulated about a line 20 to cause such line 20 to enter the device through line guide 44, line channels 32 and 34 and exit through line guide 46. This manipulation can be easily accomplished with one hand.
The positioning of channels 32 and 34, as briefly described, supra, may now be fully appreciated from inspection of FIGS. 3a-3d in conjunction with FIG. 8. The location of the line chances, as illustrated, faciltate the automatic positioning of line 20 within the device 10. A fishing line 20 is shown in FIG. 8, entering invention 10 through opening 50 in line guide 44. Line 20 passes over V-groove 98 of trigger lever 80 and between the opened cams 82 and 84. The line continues its path internal to the invention 10 over line positioning arm 86 and then exits the lower casing 40 via opening 48 of line guide 46.
Once device 10 is armed/compressed and loaded onto line 20, device 10 is released, thereby, allowing it to descend through water via the force of gravity to a point proximate the snag. Weight 172, typically 1.75 ounces or more of lead metal, is used within device 10 to facilitate the descent of the device. Weight 172 has been illustrated by way of example, in FIG. 8, as being located internal to the upper casing 42. The positioning, however, of weight 172 is not critical in so far as it does not interfere with the internal mechanisms of the device 10 or obstruct line channels 32 or 34. In some embodiments, the mass of the device 0 itself may alleviate the necessity or desirability of adding additional weight. As the device 10 descends trapped air escapes via line channels 32 and 34, line guides 44 and 46, and via trigger spring retention slot 93. As the trapped air escapes, invention 10 fills up with water and becomes non-buoyant which functions to further assist the invention 10's descent.
Upon the completion of the invention 10's descent, a tug or slight pulling is applied to line 20 in order to activate/trigger the device 10. FIG. 9 is a transitional, longitudinal, cross-sectioaal view of a preferred embodiment of the invention illustrating the clamping and severing of a line 20. As can be seen in FIG. 9, tension via the anglers tug or pulling, eliminates the slack in line 20 and exerts pressure on the trigger assembly 72. Arrow 120 indicates the direction of pulling force on line 20. More particularly, as line 20 exerts force to trigger lever 80, trigger lever 80 transfers such force to spring 78. When the force on line 20 approximates or exceeds five (5) lbs., end portion 92 of trigger spring 78 collapses in the direction of the casing grip portion 94 of the trigger spring 78. This movement results the trigger lever 80's movement, thereby causing trigger foot 90 to retract form trigger stop 108.
This action has the effect of allowing compression spring 160 to expand against surface 114 of the lower casing 40, thereby forcing lower casing 40 out of its compressed position within the upper casing 42. It may also be appreciatedfrom FIG. 9, that once device 10 is so triggered, that the movement of the lower casing 40 out from upper casing 42, also removes the contact of body ribs 110 and 112 from cam arms 136 and 138 respectively. This movement allows the stored force in spring 116 to rapidly urge cams 82 and 84 to a closed position about line 20 as shown in FIG. 9.
Cams 82 and 84 not only clamp line 20 but also continue to tighten onto the line as a result of continued pulling on line 20 after device 10 has been triggered. The movement of the cams from an open to a closed position also moves the line positioning arm 86 to a point which no longer functions to positively maintain line 20 away from blade 102.
The contact of line 20 with blade 102 is clearly shown in FIG. 9. Continued pulling on line 20 by an angler functions to severe line 20 as shown at point 118 via phantom lines. More importantly, the positioning of blade 102 with respect to cams 82 and 84 and with respect to line guide 46 forces line 20 over the blade in a pyramidal fashion. The harder an angler pulls on line 20 the more the line is forced directly into the cutting surface 102.
Once line 20 is severed, the device 10 is raised to the surface via the major portion of line 20, which is firmly affixed between cams 82 and 84. It is noted that at the moment line 20 is severed the cams tighten further due to inertia forces. The served, terminal portion 60 of line 20 exits device 10 via guide 46. Depending upon the nature and type of line to be retrieved, cams 82 and 84 may be varied. FIGS. 13 and 14 illustrate sectional views taken alone line 13--13 of FIG. 11 depicting a course/gritty surface 182 (FIG. 13) and a grooved/serrated surface 184 (FIG. 14) respectively. A course/gritty surface is often preferred for use with smooth mono-filament lines, especially such lines having a low test per square inch. A groove/serrated surface provides excellent gripping results with lines comprising materials such as cotton and/or DACRON. The embodiment of the cam illustrated in FIG. 13 and FIG. 11 further comprises a grip mounting surface 186 which is indented sightly for the application of an adhesive backed gripping surface. The indentation allows for the flush contact between the cams, after the gripping surface has been affixed to the cams.
Once the angler has retrieve the major portion of line 20 along with device 10, the angler removes device 10 from line 20. This removal is accomplished by compressing the device inwardly which as described previously causes cams 82 and 84 to open thereby allowing the retrieved line 20 to be removed from the invention 10. The invention 10 may then b conveniently stored for subsequent use.
Without departing from the spirit and scope of this invention, it is to be noted that the preferred embodiment of the invention 10 as illustrated in the drawings and as described herein, is only one particular embodiment of the invention 10 which may be utilized in conjunction with the teachings outlined herein. For example, other embodiments of the invention need not be hollow to necessarily enclose its mechanisms in order to function properly within the spirit and scope of the invention. Further, other embodiments can be so constructed by one of ordinary skill in the art to include propulsion apparatus such as gas propellants, compressed air, motorized engines and the like to propel the invention 10 in the direction of a snag regardless of the presence rr absence of gravitational forces.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form ha been made only by way of example and that numerous changes in the details of construction and combination and arrangement of parts, in addition to numerous changes in the methods of use thereof, may be resorted to with out departing from the spirit and scope of the invention.
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An apparatus and method for retrieving lines, ropes, wires, optical fibres and the like from otherwise inaccessable locations, without the need for separate control lines, dissolving tables and the like. The apparatus comprises a line guide assembly, line clamping assembly, a line cutting assembly and a triggering mechanism for the activation of the aforementioned assemblies. The triggering mechanism is activated by the application of force to the line to be retrieved.
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This application claims priority under 35 U.S.C. § 119 (e) (1) of provisional application number 60/046,446 filed May 14, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to digital pulse width modulated (PWM) display systems, more particularly to those digital PWM systems that receive display data with varying frame rates and that store PWM sequences in memory for each frame rate.
2. Background of the Invention
Digital PWM systems typically display data in the format of one sample of data per picture element (pixel) on the final image. The PWM scheme is dependent upon how many bits per pixel are generated for the given image. For example, a 4-bit system would display the most significant bit (MSB) for 8/15 the frame time, the next MSB for 4/15 the frame time, the next to least significant bit (LSB) for 2/15 the frame time, and the LSB for 1/15 the frame time. It should be noted that the LSB time is equal to 1 divided by 2'-1 where i is the number of bits per sample. This is referred to as the LSB time, and the higher order bit times are typically discussed as multiples of this LSB time, with the MSB have 8 LSB times, etc. The exact order and duration of PWM bits is called a PWM sequence.
As can be seen from the above discussion, the LSB time is tightly coupled with the frame time, as it depends upon the frame time for determining its length. In order for a display system to handle a range of frame rates, several PWM sequences must be stored and interpreted in real time to initiate data transfer to the display system with the correct timing. PWM sequences could be used that were not adapted for the varying frame rates. However, more tightly coupled sequences are more efficient because more of the available time can be used for light output.
The storing of several of these sequences in memory increases the need for memory and thereby increases the cost for the system. Therefore, a method is needed that allows for tight coupling between the PWM sequence and the frame rate, yet does not require large amounts of memory.
SUMMARY OF THE INVENTION
One aspect of the invention is a method for expanding the PWM sequence time for a display system having a varying frame rate. The time between each two events in a PWM sequence is set to be a predetermined number of clock cycles of a sequencer clock. A drop count is calculated by the system processor and sent to a counter. When the counter counts down from or up to that count, a signal is sent which causes the sequencer clock to drop a count. This increases the sequence time by causing the sequencer clock to reach the predetermined number of cycles in a longer amount of time than previously.
A second aspect of the invention is a logic circuit which enables the system processor to cause the sequencer clock to drop a count. The circuit includes a register which receives the count and an enabling signal. The enabling signal controls whether the clock dropping operation is enabled or disabled. When a predetermined number is reached, the counter sends a signal to a logic circuit. When clock dropping is enabled, the logic circuit causes the sequencer clock to miss a cycle, thereby causing it to take longer to reach the predetermined number of cycles per frame.
It is an aspect of the invention that the expansion method reduces the number of PWM sequences that need to be stored in memory.
It is a further advantage of the invention in that it does not contribute a significant amount of circuitry to the overall system, thereby minimizing additional cost.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further advantages thereof, reference is now made to the following Detailed Description taken in conjunction with the accompanying Drawings in which:
FIG. 1 shows an embodiment of a clock dropping circuit for use in a PWM display system.
FIG. 2 shows one example of a timing diagram for a clock dropping PWM display system.
FIG. 3 shows an embodiment of a clock dropping circuit with other system circuitry to enable clock dropping in a display system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Most pulse width modulated display systems rely upon the length of the display frame time to determine the necessary brightness for a given pixel in the final image. Variations in the frame must be accounted for in the PWM sequence to maintain the efficiency of the system, where efficiency is defined as using more time for light output.
PWM systems typically store the sequences in some type of memory such as programmable read-only memory (PROM). Sequence control hardware is used to interpret these sequences and control the data transfer to the display device. The size of these sequences and the number necessary to maintain system efficiency can be rather large.
One example of a display device using PWM is a spatial light modulator array. The array typically comprises individual elements in an x-y grid, with each element or a predefined number of elements corresponding to one pixel on the final image. For ease of discussion, examples will be limited to those which have one element per pixel, with no intention of limiting the scope of this invention to that embodiment.
Data is displayed by the PWM data being loaded into the control circuitry for each element. The PWM sequence determines how much light is sent to the display surface for each bit of the data for that pixel. At the predetermined intervals within the sequence, new data for the next bit is sent to the control circuitry and the elements are "reset" to accept this new data. When all of the elements are reset at the same time, it will be referred to as global reset.
An alternative to global reset is phased, or divided, reset. The array of elements on the modulator are divided into reset groups and handled separately, the PWM sequence contains more instruction and therefore requires more memory. Phased reset provides several advantages, however, such as brightness enhancement and artifact mitigation.
A typical global reset device may have 200 sequences stored in memory. A phased reset device may require as many as 20 times the instructions of a global reset device. Therefore, a phased reset device may result in 20 times more memory required to operate.
Presently, most of the sequences generated fall into a families of sequences, where each sequence in a family is related to a base sequence, with several families existing. The sequences within a family are the family base sequence expanded in time by varying factors. These could be generated dynamically by slowing down the sequencer clock so that the actual sequence time matches the frame rate. The sequencer clock is a stable clock input that is counted. When the count is reached that has been predetermined to equal the frame time, without taking into account any variations in the frame time, the next frame of data is processed, which requires the PWM sequence to start over.
One approach is to use a phase locked loop (PLL) anchored to the frame period. Only the base sequences would then be stored in memory. This relieves the system of providing a much larger memory but adds the cost associated with PLL circuitry. As mentioned above, one of the problems with storing more than the base sequences in memory is the added cost. The PLL approach does not solve this problem satisfactorily.
One embodiment of the invention is the addition of a minimal amount of logic circuitry as shown in FIG. 1. The circuitry is limited to a counter and some logic circuitry. This will not increase the cost of the system in any significant way and therefore overcomes the problems associated with the PLL approach.
The counter 14 has a down counter as shown, however, an up counter could be used as well. The counter is loaded with a count from a register and when the counter reaches zero, it sends a signal to the logic circuitry 20. The logic circuitry 20 is connected directly to the clock coming into the control circuitry of the system.
As discussed above, the sequence time equals the amount of time it takes for the clock to cycle a predetermined number of times. When the logic circuitry receives the proper signals the sequencer clock "drops" or misses a cycle. This lengthens the time the clock takes to reach its predetermined count, thereby lengthening the sequence time. The derivation of these signals will be discussed in more detail later.
The number of times the clock is dropped then determines the amount of time by which the sequence time is increased. The proper number of dropped counts for each variation in the frame time can then be determined. The time expansion factor for a sequence executed with a drop count of N is given by: ##EQU1## The factor, F N , can be used to find the effective sequence rate, f N , or period, P N , by: ##EQU2## where f b and P b are the base sequence frequency and period, or sequence time, respectively.
The maximum drop count required determines the number of bits needed for the counter. This is determined by: ##EQU3## over all valid combinations of i and j where P i is a frame period required for the system and D j is a time difference allowed between sequence lengths.
The usable frame frequency range covered by each base sequence depends on the maximum time difference, D, allowed between sequence lengths which will be referred to as the spacing. The minimum usable drop count, N min , for a base sequence period, P b , is given by: ##EQU4##
The minimum number of base sequences required in a video system can be determined by starting with the maximum frame rate. For an example, the maximum frame rate of a system will be assumed to be 76 Hz. Since frequency and period are inverses of each other, this sets the period at 0.0131579 seconds, or 13157.9 μsecs. Assuming further that the system has a maximum allowable spacing of 50 μsecs, which is D, equation 5 can then be used to determine the minimum drop count, N min . Using the above numbers in the present example, N min is the ceiling of 15.729. The ceiling function in equation 5 finds the next highest integer of the number upon which it operates, which would result in a drop count of 16.
The range of that particular base sequence is found using either equations 1 and 2, or 1 and 3. In the tables below f end could also be defined as f Nmin . Using equations 1 and 2, f N =76/(17/16)=71.529 Hz, with the period P end being 13980.3 μsecs. The next base sequence is found by using as the base sequence period, P end +D, which in this case is 13980.3+50=14030.3 μsecs. The next base sequence rate is 71.275 Hz. This process is then repeated for this base sequence and continued until the entire system frequency range has been covered.
The following tables show these calculations for three different systems. The first system has a frame rate range of 76 to 49 Hz and the second with a frame rate range of 63 to 48 Hz. Both of these systems have 50 μsec spacing. A third example is shown with a frame rate range of 74.82 to 18 Hz with 150 μsec spacing.
System 1: 76-49 Hz, 50 μsec spacing
______________________________________ f.sub.b P.sub.b Min drop P.sub.ens f.sub.endBase No. (Hz) (μsecs) count (μsecs) (Hz)______________________________________1 76.000 13157.9 16 13980.3 71.5292 71.275 14030.3 17 14855.6 67.3153 67.089 14905.6 17 15782.4 63.3624 63.132 15832.4 18 16711.9 59.8375 59.659 16761.9 18 17693.2 56.5196 56.360 17743.2 19 18677.0 53.5427 53.399 18727.0 19 19712.6 50.7298 50.601 19762.9 20 20750.8 48.191______________________________________
System 2: 63-48 Hz, 50 μsec spacing
______________________________________ f.sub.b P.sub.b Min drop P.sub.end f.sub.endBase No. (Hz) (μsecs) count (μsecs) (Hz)______________________________________1 63.000 15873.0 18 16754.9 59.6842 59.507 16804.9 18 17738.5 56.3753 56.216 17788.5 19 18724.7 53.4054 53.263 18774.7 19 19762.8 50.6005 50.472 19812.8 20 20803.5 48.0696 47.954 20835.5 20 21896.1 45.670______________________________________
System 3: 74.82-18 Hz with 150 μsec spacing
______________________________________ f.sub.b P.sub.b Min drop P.sub.ens f.sub.endBase No. (Hz) (μsecs) count (μsecs) (Hz)______________________________________1 74.820 13365.4 9 14850.5 67.3382 66.665 15000.5 10 16500.5 60.6043 60.058 16650.5 11 18164.2 55.0534 54.602 18314.2 11 19979.1 50.0525 49.679 20129.1 12 21806.5 45.8586 45.545 21956.5 12 23786.2 42.0417 41.778 23936.2 13 25777.5 38.7948 38.569 25927.5 13 27921.9 35.8149 35.623 28071.9 14 30077.1 33.24810 33.083 30227.1 14 32386.1 30.87711 30.735 32536.1 15 34705.2 28.81412 28.690 34855.2 15 37178.9 26.89713 26.789 37328.9 16 39664.9 25.21314 25.118 39811.9 16 42300.2 23.64115 23.557 42450.2 17 44947.3 22.24816 22.174 45097.3 17 47750.0 20.94217 20.877 47900.0 18 50561.2 19.77818 19.720 50711.2 18 53528.4 18.68219 18.629 53678.4 19 56503.6 17.698______________________________________
These tables are only intended as examples and are in no way intended to limit the range of frame rates or the spacing. More base sequences could be added to take advantage of breakpoints specific to a given PWM scheme.
The determination of inputs to the clock dropping circuit would be done as often as necessary to match changes in frame rate within a specified system tolerance. Once the length of the frame is determined, either by measurement or from a system command, a system control circuit 22 as shown in FIG. 3 generates the DROP ENABLE and DROP COUNT signals and causes them to be stored in register 12 by activating the DROP STORE signal. The system control circuit will perform the measurement if necessary, or receive the command that determines the frame time.
The first step in generating the clock dropping control signals is to select the base sequence that most closely matches the frame period. This base sequence is the one with the longest base period that is less than or equal to the frame period. The system control circuit performs the necessary calculations and selects the correct base sequence. The system control circuit sends the selected base sequence number to the PWM sequencer 26 so that the correct sequence program can be retrieved from the sequence store 28, which may be a PROM.
The DROP COUNT can then be calculated to match the sequence period to the frame period, P f , by: ##EQU5## where P b is the base sequence period. If P f =P b or if DROP COUNT is too large for the implemented counter, then DROP ENABLE is set to disable clock dropping and cause no sequence expansion. Otherwise, DROP ENABLE is set to enable clock dropping. In either case, the control signals are latched in register 12.
As an example for System 1 in the tables above, suppose that the frame rate is 60 Hz yielding a frame period of 16666.7 μsecs. The optimum base sequence from the table is number 4 with a base period of 15832.4 μsecs. The system control circuit commands the PWM sequencer to retrieve sequence number 4 from the sequence PROM. The DROP COUNT is calculated from equation 6 to be 19. The system control circuit finally sets DROP ENABLE to enable clock dropping and sends the commands to the clock dropping circuit 10. The resulting sequencer clock is sent to the PWM sequencer 26 which generates the appropriate timing signals for the display device.
These calculations would typically be done by the ALU of the system processor. Alternatively, the clock dropping controls could be precalculated and stored in a lookup table. Note that the register in FIG. 1 is shown as a flip/flop, but could be any type of register that transmits the signals required when indicated by the system processor.
When the count on counter 14 equals zero, the logic circuitry 20 would, if enabled, then cause the sequencer clock to drop a clock, resulting in the expansion of the sequence time. When the count equals zero, the LOAD signal on the down counter would cause the count to be reloaded so it could start counting down to the next dropped clock. The counter could also count up to a predetermined number, rather than down. The down counter shown is only shown as an example.
The clock dropping circuit is therefore used to increase the range of frame rates to which the PWM sequences can be coupled. Meanwhile, the amount of extra hardware needed is minimized, in addition to the limit on the memory discussed above.
Thus, although there has been described to this point a particular embodiment for a method and structure for time expanded pulse width modulation, it is not intended that such specific references be considered as limitations upon the scope of this invention except in-so-far as set forth in the following claims.
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A method for expanding pulse width modulation sequences that control a display system to adapt to varying video frame times. A minimal amount of extra circuitry (10) is provided that regulates a sequencer (26). After calculating the appropriate expansion factor needed to stretch a base sequence, the system control circuit (22) sends that information to the circuitry (10). The circuitry (10) includes a counter (14) that repetitively counts down a number of clock cycles and causes the clock to drop a cycle. This dropping of clock cycles causes the sequence time to be expanded, as it takes the system longer to reach the necessary number of clock cycles that determine a sequence. Several base pulse width modulation sequences could be stored in memory, each of which can be used for a range of frame times, eliminating the need for one sequence for every possible variation in the frame time.
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FIELD OF THE INVENTION
The present invention relates to the management of calls over a computer network, and in particular the merging and splitting of such calls.
BACKGROUND OF THE INVENTION
Telephone conference calls are well-known in the art. Such calls are arranged so that a new party can be added to the conference by an existing person dialing out, and any of the existing parties can leave by hanging up. Some systems allow a new party to dial in to a call, but do not allow two existing multi-way calls to be merged into one, nor allow a single existing multi-way call to be split into two. These restrictions are partly due to the nature of existing PSTN equipment, and in particular the very limited degree of control information that can be exchanged with a conventional telephone. Furthermore merging and splitting have to be very carefully coordinated across the various nodes if they are to be successful.
More recently, multi-media conferencing facilities have been developed, which provide both video and voice connections (see, e.g. "Distributed Multiparty Desktop Conferencing System: MERMAID", by K. Watabe, S. Sakata, K. Maeno, H. Fukuoka, T. Ohmori, in "CSCW '90: Proceedings of the Conference on Computer-Supported Cooperative Work", 1990). A CCITT proposal (part of the T.12x draft standards) for a Multi-media Control Unit to handle multi-media conferencing imposes many of the same restrictions as currently exist for telephone conferences. This is partly due to the adoption of a relatively fixed, hierarchical structure, which centralizes control at a single node. A need exists for a call management system which does not suffer from such limitations.
SUMMARY OF THE INVENTION
Accordingly, the invention provides a method of splitting an initial call that exists across an initial set of nodes into first and second calls across two disjoint subsets of the initial set, each node comprising a computer workstation in a computer network and including means responsive to messages from other computers in the network to join or leave a call, and each node maintaining a list of calls in which that node is participating, an entry in the list for a call including the identities of all the other nodes in that call, the method comprising the steps of:
producing at one node in said initial set a list of the subset of nodes to be included in said first call, whereby the second call is to be between nodes in the initial set but not in said subset;
said one node sending a message to each node in said subset of nodes including instructions to leave said initial call and join said first call;
each node upon receipt of said message performing the necessary actions to leave the initial call and join the first call.
Effectively the call is divided into two groups by splitting off a subset into a new call, with the remnant of the original call becoming the second group. Note that in this context "network" refers to a logical grouping of computer workstations, which may be represented by one or more physical networks. In other words, the network may extend across (parts of) one or more LANs, linked for example by an ISDN connection.
In a preferred embodiment, each call has a name, and no node may participate in two calls laving the same name, and the method further comprises the steps of producing at said one node a name for said first call, and including the name for said first call in the message sent to each node of said subset. Preferably the name of the initial call is included in the message sent to each node in said subset. In some circumstances it may be possible that not all the nodes that split off into the new group correctly interpret the instructions as also requiring them to leave the original call. However, the practical effects of this are likely to be minimal since the newly split off group at least will contain only the correct participants.
It is also advantageous if, as each node of said subset receives said message from said one node, it sends back a confirmation message to said one node, which then forwards the message to the other nodes that have so far joined said subset. This exchange of messages allows each node to update its record of the current particants in each call, thereby ensuring that future actions (e.g. such as further splitting) can be accomplished correctly.
The invention also provides a method of merging first and second calls that exist across first and second initial sets of nodes into a single call across a superset of said first and second initial sets, each node comprising a computer workstation in a computer network and including means responsive to messages from other computers in the network to join or leave a call, and each node maintaining a list of calls in which that node is participating, an entry in the list for a call including the identities of all the other nodes in that call, the method comprising the steps of:
one node sending a message to each node in said first initial set of nodes including instructions to leave said first call and join said single call;
said one node sending a message to each node in said second initial set of nodes including instructions to leave said second call and join said single call;
each node upon receipt of said message performing the necessary actions to leave the first or second initial call as appropriate and join the single call.
Merging is therefore achieved by setting up a completely new call containing all the participants of the two original calls. An alternative strategy would be to invite all those nodes in, for example, the second call to join the first call. However, this can be disadvantageous in some special circumstances, in that the lack of symmetry may result in some inequality between old and new members of the call (this may surface, for example, in resource allocation in a token passing environment).
In a preferred embodiment, each call has a name, and no node may participate in two calls having the same name, and the method further comprises the steps of producing at said one node a name for said single call, and including the name for said single call in the messages sent to each node in said first and second sets. Preferably the name of the first call is included in the message sent to each node in said first set, and the name of the second call is included in the message sent to each node in said second set. Again, in some cases it may be that a node does not recognize that not only must it join the new, unified call, but that it must also leave its original call. In practice however, this is of little importance, since the original calls become defunct or dormant. The only disadvantage of not withdrawing from the original call is therefore the existence of (relatively small) continued overheads associated with maintaining these original calls.
Sometimes an initial step will be performed, which involves selecting said one node, and if the selected node is not already included in both the first and second calls, adding said one node to the first or second call as appropriate. This process ensures that the one node is inside both calls before it attempts to control their merger, rendering the performance of future actions simpler.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described by way of example, with reference to the following drawings:
FIG. 1 is a simple diagram of a computer network;
FIG. 2 is a schematic diagram depicting the main components of a typical computer workstation forming a node in the network of FIG. 1;
FIG. 3 illustrates the main software components running on the computer workstation of FIG. 2;
FIG. 4 is a simplified flow chart of the procedure for merging two calls together; and
FIG. 5 is a simplified flow chart of the procedure for splitting a single call into two separate calls.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a network of computers connected by a variety of links: for example nodes A-F are part of a first LAN 10, nodes G-I are part of a second LAN 20, with nodes F and G being connected by an ISDN link 25. Messages can be exchanged between these computers over the LAN or ISDN connections in accordance with appropriate protocols. At this level the arrangement of FIG. 1 is completely conventional: the communications protocols are well-known in the art and are typically the subject of international CCITT or IEEE standards, so that they will not be described further.
A highly simplified schematic diagram of a conventional computer workstation is shown in FIG. 2, such as may form a typical node in the network of FIG. 1. The workstation includes a system unit 40, keyboard 42 and mouse 44 for input, a computer screen for display 46, and a hard disk drive 48 for data storage. The system unit includes a bus 60 to which is connected the central microprocessor 50 which controls the workstation, semi-conductor memory (ROM/RAM) 52, and I/O support devices 54 for the keyboard, display, etc. Also included in the system unit is an adapter card 62 containing appropriate hardware and software to allow the workstation to be attached to a LAN 64. The computer workstation of FIG. 2 may be further equipped with other devices (not shown), such as a microphone or video camera to allow sound and/or video input. Typically such extra devices will have their own adapter cards. The computer workstation may also include additional adapter cards (not shown) to support other modes of communication, such as ISDN. The computer workstation of FIG. 2 may for example be an IBM® PS/2® computer fitted with a Token Ring adapter card (also available from IBM).
FIG. 3 shows more detail of the software components running in the workstation of FIG. 2. The central component is a communications control layer (CCL) 70 which is responsible for managing at a logical level the connections and data flow across the network. Below the CCL are the device drivers 74, which are pieces of code used to directly control hardware attachments, such as displays or communications adapters, plus other associated code. Each adapter card or I/O device has its own device driver. When the CCL wishes to send a message to another node in the network, it passes the message together with appropriate information (including the target node) to the device driver associated with the communication adapter card for the selected link (ISDN, LAN or whatever). Device drivers and message transmission protocols are very well-known in the art, and so will not be described further.
The CCL also has access to operating system services 72 and, via suitable bridge code (not shown), to various data files 76, which can be used for example to store detailed addresses of network users, and various operating system services. Also depicted in FIG. 3 are the applications 78, 80, 82, which are responsible for providing the required functions for the user (typical applications might represent video conferencing, electronic mail, collaborative working, and so on). Modern applications utilize operating system services to provide a graphical user interface (GUI), whereby the user moves a mouse to locate a cursor on the screen over an icon or menu item representing the desired selection, and then clicks on the mouse to activate that selection.
One particularly important application shown in FIG. 3 is the Call Manager 78, which plays a central role in initiating and controlling calls to and from other nodes in the network. The CCL will recognize only one Call Manager at a node at any given time. It is possible for the user to select another application to perform the functions of the Call Manager, in which case the CCL must be informed accordingly.
The Call Manager interacts with the CCL to commence a call to another node, normally as a result of direct user control of the Call Manager, although sometimes an application may pass an appropriate request to the Call Manager to set up a call on its behalf. It is possible for an application to interact directly with the CCL to instigate a call, but in this case the CCL first notifies the Call Manager of the request. Typically the Call Manager would then obtain confirmation from the user of the intended communication in order to prevent unwanted applications such as viruses from propagating over the network. The Call Manager is also notified of all incoming calls to a node, and is responsible for deciding whether or not to accept such a call (normally it will ask the user to make this decision). Further aspects of Call Manager operation are explained in more detail below.
With regards to actual communications between the Call Manager (or any other application) and the CCL, the latter has a set of function calls which can be invoked by the Call Manager when required. In order for the CCL to initiate the flow of information in the reverse direction (i.e. back to an application), such as to notify the Call Manager that a call has arrived, a call-back function is supplied by each application interacting with the CCL. A call-back function is a standard programming technique which provides the address of a routine in the calling application. The CCL effectively calls this function to write a message from the CCL to the application into a particular memory area belonging to the application.
From the perspective of time user, communications with other machines (or possibly between two applications running on the same machine) are represented by calls between applications. However, at the CCL, everything is handled via two related calls, "share" and "unshare", which are used to add or remove applications from a "sharing set". These calls are passed from an application such as the Call Manager to the CCL. The syntax of these two calls is:
share.sub.-- app(X, A, Y, B, N, U)
unshare.sub.-- app(X, A, N, U)
where X and Y are nodes, A and B are applications running on nodes X and Y respectively, N is the name of a sharing set of applications to which A already belongs, and U represents user information that may be utilized for a variety of purposes (other parameters not necessary to an understanding of the present invention may also be included). Note that Y may be identical to X, in which case the two applications are running on the same machine.
The share command can be issued by an application other than A, for example by the Call Manager at node X, or even from another machine. Likewise, the unshare command may also be issued by an application other than A, although in this case, only from another application on the same machine. For the share command, application B will generally be specified by name, in which case assuming that the call is to be accepted, the Call Manager at node Y will either complete the share with an existing instance of application B at node Y, or launch a new version of that application. If N (identifying the sharing set) is NULL for the share command, then B is being asked to select which of B's sharing sets A can join. If N is null for the unshare command, then application A is removed from all its sharing sets.
The process of setting up a simple two-way call will now be described. As mentioned above, the user may initiate such a call either from the Call Manager, or from another application. In the latter case, the application may pass the share command directly to the CCL itself, or may go through the Call Manager. In order to start such a call, the user is typically presented with a directory of names and a class of service. The class of service represents the type of communication that will be performed, e.g. video, data transfer, and voice, and allows the CCL to ensure that the desired communication will be physically possible (e.g. that sufficient bandwidth can be obtained). The class of service effectively represents a further parameter to the share command in addition to those listed above. Typically the name will be some alias or other shortened form of address; in such a case, the full address can be accessed from stored data files, which may or may not be maintained at that particular node.
Once the user has selected the person to communicate with and the necessary class of service, a share command is issued to the CCL with the following structure:
share(X, NULL, Y, NULL, "callid1", NULL)
where "NULL" is taken as referring to the Call Manager. Thus this call establishes a sharing set, named as "callid1", between the Call Manager at node X and the Call Manager at node Y. Under the current protocol, when two applications wish to share, the normal procedure is to form a sharing set including the two Call Managers from the respective nodes, which effectively controls communications between the two nodes (this is not necessary if the two Call Managers are already in a suitable sharing set). The applications then establish a parallel sharing set between themselves. The name of the node Y represents the identity of the person to be called. Note that "callid1" must be chosen to avoid any ambiguity. One relatively straightforward way of achieving this is to combine the node name (X in this case), which is guaranteed to be globally unique, with a number that is incremented each time a new call is made.
The exact response of the CCL to the share request will vary according to the current status and physical configuration of the network. In some cases, such as when X and Y are connected by an ISDN line, it is normally necessary to explicitly set up a call from node X to node Y. Sometimes the new call can be multiplexed onto an existing link, but depending on class of service, this may not always be possible. Of course, the CCL may not know full details of the route from X to Y, but only know the first staging post (messaging and routing are very well understood in the art). Irrespective of the exact procedure used, the result is that a share request is sent from node X to node Y. The Call Manager at Y can then decide whether or not to accept the share, and if so respond accordingly to the Call Manager at X. Assuming that the response is positive, the Call Managers at nodes X and Y are now in a sharing set together.
Extending a call from a two-way call to a multi-party call is a logical extension of the above process. For example, suppose X and Y are already in a call, X01, and Y wants to add in node Z. This can be achieved by the Call Manager at Y issuing the following request;
share.sub.-- app(Y, NULL, Z, NULL, "X01", NULL)
This results in a share request being sent from Y to Z as described for a two-party call, with Z then having the ability to accept or decline the call. Assuming the latter, then Z sends a share -- confirm message back to Y, who then forwards this message onto all the other nodes in the sharing set "X01". In this way the other nodes learn about the addition of a new member to the sharing set. These nodes, in turn, send a share -- confirm message to node Z, thereby informing Z of the other nodes in the sharing set. This sequence of messages ensures that no confusion arises even if nodes are added simultaneously to different nodes within the same sharing set.
A slightly different process is required if a party outside a call, Z, wishes to join an existing call, X01, between parties X and Y, on its own initiative. In this case an application at Z (e.g. the Call Manager) sends the following command to the CCL:
share.sub.-- app(Z, NULL, Y, NULL, NULL, NULL)
which results in the CCL sending a share request to node Y. This is received by the Call Manager at Y since no application is explicitly specified. Because the call id field is also null, there are two possible courses of action for the Call Manager to adopt: it can either treat the message as a request to start a new call, or as a request to join an existing call. Typically the Call Manager will refer this choice to the user to select which option to follow. The first option leads to the establishment of a new call (say "Y01"), whilst the second leads to the inclusion of Z in call id X01, which now involves all three nodes X, Y, and Z.
It is possible to help the decision at Y by using the facility to incorporate user information into a share request. Thus Z could make the following call to the CCL:
share.sub.-- app(Z, NULL, Y, NULL, NULL, "JOIN X01")
When this gets sent to Y, the Call Manager can interpret this as a request from Z to join into call X01 (as opposed to setting up a new call). Of course in order for this approach to be possible, Z must have a knowledge of call X01; this might be obtained for example if call X01 represented a pre-arranged fixture.
If a node, Z, wishes to leave a call, the Call Manager passes the following unshare command to the CCL:
unshare.sub.-- app(Z, NULL, "X01", NULL)
which indicates that the Call Manager at node Z is to be removed from the sharing set having the id "X01" (again, "NULL" is used in place of an application name to indicate tile Call Manager). The CCL then sends appropriate notification to the other applications in the sharing set "X01". Note that the unshare command can only be issued by an application at the node to be disconnected, so that it is not possible to remotely drop a third party from a call.
Using the basic mechanisms described above, it is now possible to develop more sophisticated procedures to handle complex call operations. Considering first call merging, it is assumed for the time being that call id's are generated as described above, i.e. by taking the node name as the root, and adding a number which is incremented for each call originated by that node. This ensures that the call id will be unique across the network, so that if two calls are to be merged, they will initially have different call id's (this depends, in turn, of course, on the ability to provide each node with a unique identifier: there are many ways of doing this, such as incorporating the identifier into each copy of the software, or each machine unit, or having some form of registration procedure).
Since there is no facility for changing the name of a sharing set, an alternative process must be employed in order to merge two calls together. This can be achieved by having a node that is a participant in both calls, X say, invite each member of the two existing calls to join a third call (if there is no common member, this can be arranged by using the call joining procedure described above). The user information parameter can then be used to indicate that the new call is a merger of the previous two calls. Thus assuming X is currently in calls Y02 and Z03, it issues the following command to the CCL:
share.sub.-- app(X, NULL, Y, NULL, "X02", "MERGE Y02 Z03")
Analogous commands can be provided for all the other nodes in the calls Y02 and Z03. These other nodes such as Y can then interpret the user information as an instruction to unshare from call Y02 and Z03 once they have joined the new call X02. Note that even if their Call Managers do not recognize this aspect of the user information, the only result will be that they fail to leave the old call--they will still respond to the share to join the new merged call. It should also be appreciated that since it is not possible to issue a remote "unshare" on behalf of another node, the user information string is the only available mechanism for instructing (or requesting) other nodes to leave a specified call.
This procedure is illustrated by the flow chart of FIG. 4: a node Z is located which is in both calls (X1 and Y1) (step 100). If no such common node already exists, then it is normally necessary for a node from one call to join the other call in order to produce such a common node. The common node then sends out messages to all the nodes in call X1 to leave this call and join a new call Z1 (step 110). Note that the name of the new call has been generated using the convention discussed above, by appending a number to the name or id of the node setting up the call. In this way, the call can be guaranteed to have a unique name (it is assumed that each node maintains a record of the calls that it has initiated, and so will not use the same number twice). On receipt of these messages the nodes in call X1 act accordingly (step 120). An analogous process occurs for the nodes in call Y1; node Z sends out messages instructing them to leave this call and join new call Z1 (step 130), and the nodes act accordingly on receipt of the message (step 140). Note that steps 110 and 120 may occur in parallel with steps 130 and 140 i.e. the nodes in both calls may be processed simultaneously.
If it is desired to split a call into two, then again this must be accomplished by using the share and unshare commands described above. One node must take responsibility for initiating the split. This node then sends a series of share calls to all the nodes that are to be part of the second (split call). Thus, if a node Y, for example wants to split off from existing call X02, and start a new call Y01, it achieves this by issuing the following command to the CC1,
share.sub.-- app(Y, NULL, Z, NULL, "Y01", SPLIT X02")
This results in a share message being sent to node Z to join the new call "Y01". Analogous messages are sent to all the other nodes that are to be included in the new split call. Furthermore, these nodes interpret the user information "SPLIT X02" as an indication that at the same time as joining the new call Y01, they should also issue an unshare command to disconnect themselves from the call X02.
This procedure is illustrated by the flow chart of FIG. 5. Node Y, which is in an existing call, produces a list of nodes, currently in the existing call, which are to be split off into a new call Y1 (step 200). Generally Y will wish to be included itself in call Y1. Node Y then sends messages to all the nodes in the list to join the new call Y1, and to leave the existing call (step 210). The nodes that receive such a message act accordingly (step 220), resulting in a new call containing a break-away subset of the original call, which now only contains the remainder of nodes (ie those nodes which have not joined new call Y1).
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A network comprises a set of nodes, each comprising a computer workstation in a computer network and including means responsive to messages from other computers in the network to join or leave a call. Each node maintains a list of calls in which that node is participating, an entry in the list for a call including the identities of all the other nodes in that call. In order to split a single call one node sends messages to a subset of nodes to join a second call, and leave the original call. The remaining parties in the original call then continue in a call of reduced scope. In order to merge two calls together, a node that is common to both calls sends messages to all the nodes in both calls, instructing them to leave the existing call and join a new call.
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RELATED PATENT, AND APPLICATION
[0001] The present invention is related to U.S. Pat. No. 7,207,141, entitled “Sliding Door Insert for Portable Pet Portal,” issued on Apr. 24, 2007. The present invention also takes priority from co-pending Provisional Application No. 61/204,872, filed on Jan. 12, 2009. The teachings of the related Patent, and co-pending Provisional Application, are incorporated herein by reference to the extent that they do not conflict herewith.
FIELD OF THE INVENTION
[0002] The present invention relates generally to building access, and more particularly to a storm window and window screen for a window module.
BACKGROUND OF THE INVENTION
[0003] When a pet door panel is inserted in a sliding patio door the ability to utilize the screen door feature of the sliding patio door to ventilate the room to outside air is restricted since doing so would make the pet portal unusable as the screen door would block ingress and egress from and to the outside of the room. For example, the pet door panel, as described in U.S. Pat. No. 7,207,141, consists of three modules that are assembled to form the pet door panel for a sliding patio door. The bottom module contains the pet portal while the center and top modules are essentially solid filler pieces.
[0004] The current state of the art pet door panels for sliding patio doors do not have any ventilation feature and must be removed from the sliding patio door in order to close the screen to ventilate the room while keeping insects out or sliding the screen door closed over the pet door panel preventing ingress and egress of a pet through the pet portal. An aftermarket filler strip is available that may permit the screen door to be closed to the edge of the pet door panel leaving the portal free for pet use. However, in this configuration the screen door cannot be locked to prevent passage of a person.
[0005] Accordingly, there is a need for a pet door panel adapted to permit ventilation to the outside air directly through the sliding door insert for portable pet portal while providing a double pane clear polymer storm window for protection in foul weather and/or insulation in cold weather. There is a further need for a pet door panel wherein the center and top modules have openings housing a ventilation screen and storm window. In this manner, the storm window can be removed allowing outside air to infiltrate into the interior of the room containing the patio door and pet door panel without the need to remove the pet door panel and close the sliding patio door screen. There is a further need for a pet door panel whereby the screens are an integral part of the pet door and as such permit ventilation with the pet door panel installed and the sliding patio door locked preventing the unwanted passage of a person.
SUMMARY OF THE INVENTION
[0006] The present invention relates generally to a pet door panel adapted to permit ventilation to the outside air directly through the sliding door insert for portable pet portal while providing a double pane clear polymer storm window for protection in foul weather and/or insulation in cold weather. The pet door panel includes center and top modules having openings housing a ventilation screen and storm window. In this manner, the storm window can be removed allowing outside air to infiltrate into the interior of the room containing the patio door and pet door panel without the need to remove the pet door panel and close the sliding patio door screen. The pet door panel includes screens, which permit ventilation while the pet door panel is installed and the sliding patio door is locked, thereby preventing the unwanted passage of a person.
[0007] The present invention is operatively associated with a modular component pet access door designed for use in sliding glass patio doors. The modular construction permits the apparatus to be packaged and stored in a portable compact container when in a disassembled state. The compact size of the disassembled unit minimizes storage space requirements while facilitating transportation opportunities by the retailer and consumer. Modular construction and the design of components permit the invention to be changed in the field to accommodate a variety of styles and sizes of sliding glass patio doors. The universal nature of the modular construction and component system enhances the portability of the apparatus and permits the pet access door to be adjusted in the field to accommodate a growing pet or a new pet.
[0008] The present invention requires no tools to install nor does it require modification to any component of an existing sliding glass patio door. When assembled the modules and components create a sliding glass patio door pet access door panel.
[0009] The present invention is designed for simple assembly in the field by the consumer. Once assembled the panel may be installed and removed as one piece. The leading edge of the panel is designed to fit into the moveable sliding door side of the patio doorframe to create a secure fit and effective weather seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following drawings are illustrative of embodiments of the present invention and are not intended to limit the invention as encompassed by the claims forming part of the application, wherein like items are identified by the same reference designations:
[0011] FIG. 1 is a front or interior elevational view of the pet access door installed in a sliding glass patio door with the moveable sliding door in a closed position, providing partial access through the sliding glass door when the moveable sliding door is moved to an open position, for various embodiments of the invention absent a storm window.
[0012] FIG. 2 is a back or exterior elevational view of the pet access door of FIG. 1 installed in a sliding glass patio door with the moveable sliding door in a closed position, providing partial access through the sliding glass door when the moveable sliding door is moved to an open position.
[0013] FIGS. 3A-3C show front elevational assembly views of the five primary modules and components comprising the pet access door panel of FIG. 1 , and illustrate how the modules and components slide together to assemble the pet access door.
[0014] FIG. 3D is a perspective view illustrating the initiation of installation of the pet access door of FIG. 1 into a sliding glass patio door.
[0015] FIG. 3E is a partial perspective and elevational view illustrating a step in the installation of the pet access door of FIG. 1 into a sliding glass patio door.
[0016] FIG. 3F is an elevational view illustrating a step in the installation of the pet access door of FIG. 1 into a sliding glass patio door.
[0017] FIG. 4A is a front elevational view of a center module of the pet access door panel of FIG. 1 further including an opening, a ventilation screen, and a storm window in position for one embodiment of the present invention;
[0018] FIG. 4B is a top cross sectional view of the center module taken along 4 B- 4 B of FIG. 4A in accordance with the present invention;
[0019] FIG. 4C is a trailing edge view of the center module of FIG. 4A in accordance with the present invention;
[0020] FIG. 5A is an interior side elevational view of a center module half in one embodiment of the present invention;
[0021] FIG. 5B is a top cross sectional view of the center module half taken along 5 B- 5 B of FIG. 5A in accordance with the present invention;
[0022] FIG. 5C is a bottom view of the center module half of FIG. 5A in accordance with the present invention;
[0023] FIG. 6A is an interior side elevational view of a left side center module half in one embodiment of the present invention;
[0024] FIG. 6B is an interior side elevational view of a right side center module half in one embodiment of the present invention;
[0025] FIG. 6C is a cross sectional view of the right side and left side center module halves of FIGS. 6D and 6E joined along the interior sides to form the center module in accordance with the present invention;
[0026] FIG. 6D is a cross sectional view of the left side center half taken along 6 D- 6 D of FIG. 6A in accordance with the present invention;
[0027] FIG. 6E is a cross sectional view of the right side center module half taken along 6 E- 6 E of FIG. 6B in accordance with the present invention;
[0028] FIG. 7A is a front elevational view of a ventilation screen of the center module for one embodiment of the present invention;
[0029] FIG. 7B is a right side elevational view of the ventilation screen of FIG. 7A with the left side elevational view being substantially the same in accordance with the present invention;
[0030] FIG. 7C is a cross sectional view of the ventilation screen along 7 C- 7 C of FIG. 7A in accordance with the present invention;
[0031] FIG. 7D is a top plan view of the ventilation screen of FIG. 7A with the bottom plan view being substantially the same in accordance with the present invention;
[0032] FIG. 8A is a front elevational view of a storm window of the center module for one embodiment of the present invention;
[0033] FIG. 8B is a right side elevational view of the storm window of FIG. 8A in accordance with the present invention;
[0034] FIG. 8C is a left side elevational view of the storm window of FIG. 8A in accordance with the present invention;
[0035] FIG. 8D is a top plan view of the storm window of FIG. 8A , the bottom plan view being substantially the same in accordance with the present invention;
[0036] FIGS. 9A , 9 B and 9 C, in combination, show an exploded assembly view of the center module in one embodiment of the present invention;
[0037] FIG. 9D is a cross sectional view of the storm window taken along 9 D- 9 D of FIG. 9A in accordance with the present invention;
[0038] FIG. 9E is a cross sectional view of the ventilation screen taken along 9 E- 9 E of FIG. 9B in accordance with the present invention;
[0039] FIG. 9F is a cross sectional view of the joined module halves taken along lines 9 F- 9 F of FIG. 9C in accordance with the present invention;
[0040] FIG. 10A is a partially assembled view of the center module having the storm window partially inserted over the ventilation screen with the storm window and ventilation screen assembly partially mounted into the module in one embodiment of the present invention; and
[0041] FIG. 10B is a cross sectional view of the center module taken along 10 B- 10 B of FIG. 10A in accordance with the present invention.
[0042] FIG. 11 is a front or interior elevational view of the pet door panel shown in FIG. 1 , but with the addition of a storm window and screen in each of the upper two modules.
DETAILED DESCRIPTION OF THE INVENTION
[0043] As shown in FIGS. 1-3A to 3 F, the preferred embodiment of the invention, pet door panel 25 , is installed between the sliding door frame 11 , and the leading side of frame 15 on movable sliding door 21 , to provide a means of ingress and egress for a pet. Drop lock security lock 6 is installed on the interior side of stationary sliding door 21 , between sliding door frame 11 , and the trailing side of frame 15 on movable sliding door 21 , to secure pet door panel 25 between sliding door frame 11 and the leading side of frame 15 on movable siding door 21 , to prevent movable sliding door 21 from being opened with pet door panel 25 installed. Sliding door frame 11 is typically secured to a building structure 23 , such as a home or office. For illustrative purposes all elevational views, except as noted, depict the sliding glass patio door in a right opening configuration. Therefore, when describing various elements of the invention reference made to right and left side views pertains to installation of the invention in a right opening sliding glass door configuration. However, since the invention may be installed in either a right or left opening sliding glass patio door configuration the term left or right is relative, therefore, the terms leading, trailing, interior and exterior are used in combination or in place of the terms right and left side and front and back views where referenced.
[0044] The sliding door frame 11 has a lower track portion 29 and an upper track portion 27 . The lower track portion 29 slideably receives at least one sliding door member 21 therein. A complementary upper track portion 27 is typically positioned on the upper side of the siding glass door frame 11 , in alignment with the lower track portion 29 , enabling the sliding door member 21 to be slideably moved between open and closed positions within the sliding door frame 11 .
[0045] The preferred embodiment of the invention consists of a pet door panel 25 with pet portal 146 , drop lock security lock 6 with locking bracket 202 , and storage bracket 208 . As shown in FIG. 3A , pet door panel 25 is an assembly consisting of five primary components; top module weather seal 1 , top module 2 , center module 3 , bottom module 4 with pet portal 146 and bottom module weather seal 5 . In this embodiment, the modules 2 and 3 are shown as being solid, without storm windows or screens, for the preferred embodiment to be described in detail below. Top module weather seal 1 , top module 2 , center module 3 , bottom module 4 with pet portal 146 , and bottom module weather seal 5 are slideably attached to one another for assembly, disassembly, or replacement, as shown in FIG. 3B , via an interlocking tongue and groove system integral to each component. More particularly, interlocking groove 85 , located in the lowermost portion of top module weather seal 1 , is slideably attached to interlocking tongue 9 located on the uppermost portion of top module 2 , as indicated by directional arrow(s) 35 and/or 350 . Interlocking tongue 9 , located on the lowermost portion of top module 2 , is slideably attached to interlocking groove 22 located on the uppermost portion of center module 3 , as indicated by directional arrows 35 and/or 350 . Interlocking groove 22 located in the lowermost portion of center module 3 is slideably attached to interlocking tongue 19 located in the uppermost portion of bottom module 4 as indicated by directional arrows 35 and/or 350 . Interlocking tongue 19 located in the lowermost portion of bottom module 4 is slideably attached to interlocking groove 96 located in the uppermost portion of bottom module weather seal 5 as indicated by directional arrows 35 and/or 350 .
[0046] FIG. 3C shows assembled pet door panel 25 with pet portal 146 . Top module weather seal 1 is attached to top module 2 at seam 37 , top module 2 is attached to center module 3 at seam 39 , center module 3 with pet portal 146 is attached to bottom module 4 at seam 41 , and bottom module 4 with pet portal 146 is attached to bottom module weather seal 5 at seam 43 .
[0047] FIGS. 3D-3F show installation of the assembled pet door panel 25 with pet portal 146 into an existing sliding glass door assembly. Although assembled pet door panel 25 may be assembled in place within sliding door frame 11 , the preferred method of assembly is accomplished on a flat surface such as a floor or table top. When assembled outside of sliding door frame 11 , the inventive assembled pet door panel 25 is brought to sliding door frame 11 as shown in FIG. 3D . FIG. 3E shows movable sliding glass door 21 being pulled away from sliding door frame 11 to open movable sliding glass door 21 as indicated by directional arrow 45 , to permit pet door panel 25 to be installed. The top module weather seal 1 component located on the uppermost portion of assembled pet door panel 25 is lifted up into a recess of upper track portion 27 of sliding door frame 11 , as shown in by directional arrow 47 , and then rotated into alignment with the upper track portion 27 and a recess of lower track portion 29 of sliding door frame 11 . The top module weather seal 1 is constructed to allow a spring loaded flexible sleeve to compress in order to fit pet door panel 25 between upper track portion 27 and lower track portion 29 of sliding door frame 11 . When in alignment with upper track portion 27 and lower track portion 29 of sliding door frame 11 , the bottom module weather seal 5 component located on the lowermost portion of assembled pet door panel 25 is lowered into the recessed lower track portion 29 of sliding door frame 11 . As shown in FIG. 3F , after assembled pet door panel 25 is in place in upper track portion 27 and lower track portion 29 of sliding door frame 11 , between the leading side of frame 15 on movable sliding glass door 21 and sliding door frame 11 , movable sliding glass door 21 is pulled closed against assembled pet door panel 25 as indicated by directional arrow 49 . In turn, assembled pet door panel 25 is pulled against sliding door frame 11 as indicated by directional arrow 51 restricting access through movable sliding glass door 21 , while providing egress and ingress for pets through pet portal 146 . Frame 15 of movable sliding glass door 21 abuts the trailing side of assembled door panel 25 within a channel formed by trailing side weather seal shims (not shown) in top module 2 and bottom module 4 , and weather seal shims (not shown) in center module 3 , that comprise assembled pet door panel 25 , with assembled pet door panel 25 installed and movable sliding glass door 21 in a closed position. When installed, the leading side of assembled pet door panel 25 abuts sliding door frame 11 .
[0048] After installation of assembled pet door panel 25 as described above, drop lock security lock 6 is installed between the trailing side of frame 15 on movable sliding glass door 21 by drop lock security lock 6 handlebar 180 and sliding door frame 11 , as shown in FIG. 1 . Drop lock security lock 6 consists of an adjustable lower housing assembly that sits in lower track portion 29 of sliding door frame 11 between the trailing side of frame 15 on movable sliding door 21 and sliding door frame 11 with assembled pet door panel 25 installed. Drop lock security lock 6 is attached to the trailing side of frame 15 on movable sliding door 21 by handlebar 180 , and locking bracket 202 which is mounted on the trailing side of frame 15 of movable sliding door 21 . Drop lock security lock 6 can be installed in any sliding glass door between the trailing side of frame 15 on movable sliding glass door 21 and sliding door frame 11 , with or without assembled pet door panel 25 installed to prevent forced entry from the exterior or unintentional opening from the interior of the structure.
[0049] In another embodiment of the invention, drop lock security lock 6 is the primary means of locking movable sliding glass door 21 with assembled pet door panel 25 installed. In order to open movable sliding glass door 21 , the handlebar 180 is rotated out of a locked position in locking bracket 202 and lifted to storage bracket 208 also located on the trailing side of frame 15 on movable sliding glass door 21 . In so doing, security lock 6 is lifted out of lower track portion 29 of sliding door frame 11 allowing movable sliding glass door 21 to be pulled opened for passage or installation or removal of assembled pet door panel 25 .
[0050] Top module 2 , center module 3 , and bottom module 4 are designed to be of an injection molded or injection blow molded polymer construction with a rigid insulation core. This type of construction provides privacy while providing insulation quality superior to prior art. All three modules are designed to fit a variety of sliding glass patio door heights and door thicknesses through an adjustable top module weather seal 1 and left or trailing side and right or leading side weather seal shims 12 or 13 , and 8 , respectively.
[0051] FIGS. 4A , 4 B and 4 C show details of front elevational, top cross sectional trailing edge, and trailing edge views, respectively, of the center module 3 with a window opening 78 having a circumferential channel 80 in which a ventilation screen 102 and storm window 104 are installed. The top module 2 ventilation screen storm window configuration is identical, other than possible dimensional differences, and the use of a top module weather seal 1 , as described above.
[0052] In one embodiment of the invention all three modules 2 , 3 , and 4 comprising the pet door panel 25 are of a two-piece construction consisting of two halves that are joined together to form a single module. This type of construction permits the formation of recesses 90 , 92 , 94 , and 96 on the interior sides of module halves 100 and 101 , respectively, for the top module 2 and center module 3 . These recesses 90 , 92 , 94 , and 96 form the ventilation screen 102 and storm window 104 channels within the module 3 , when the halves 100 and 101 are joined. FIGS. 5A , 5 B, and 5 C show a center module half 100 in three views, interior side elevational, top cross sectional, and bottom, respectively, the window opening 78 , ventilation screen recess 92 , and storm window recess 90 . FIGS. 6A , 6 B, 6 C, 6 D, and 6 E depict both center module 3 halves 100 , 101 each shown in interior views ( FIGS. 6A , 6 B), respectively, trailing edge cross sectional views ( FIGS. 6D , 6 E), respectively, and as joined ( FIG. 6C ) showing ventilation screen and storm window channels formed by the recesses 92 , 96 , and 90 , 94 , respectively, with the halves 100 , 101 being joined to complete the module 3 , in this example.
[0053] The ventilation screen 102 is shown in FIGS. 7A through 7D in front elevational, left side, cross sectional side view taken along 7 C- 7 C, and a top plan view. Note that the screen 102 is encased in a polymer frame 108 with molded in or added soft rubber gaskets 109 on the outside and inside perimeters of the frame that are designed to seal the ventilation screen against the channel within the module formed by the recesses 92 , 96 in the joined halves of the module 3 , and to seal against the interior of the double pane storm window 104 when inserted over the ventilation screen frame 108 . The rubber gasket 109 around the perimeter of the ventilation screen seals against the module halves 100 , 101 to prevent air infiltration, while the inside perimeter gasket seals 110 against the inside of the double pane storm window to enhance the insulation quality of the storm window.
[0054] In FIGS. 8A through 8D , the storm window 104 is a “U” shaped clear tempered glass or clear polymer panel formed to create two panes 112 , 113 with a closed end 114 , permitting storm window 104 to be inserted over the ventilation screen 102 and into the storm window channel in the module 3 formed by the recesses 92 , 96 with the halves 100 , 101 joined. FIGS. 9A through 9C , in combination, show an exploded assembly view of the module 3 components, including storm window 104 , and ventilation screen 102 . FIGS. 9D through 9F show top cross sectional views of the module 3 components 102 , 104 of FIGS. 9A through 9C , respectively. The ventilation screen 102 is inserted into the module 3 by sliding the screen 102 into the channel created by recesses 92 , 96 for that purpose in the trailing edge of the module 3 . The storm window 104 is then inserted by sliding it over the ventilation screen 102 and inside the channel created by recesses 90 , 94 for that purpose in the module. FIGS. 10A and 10B further illustrate the process of inserting the ventilation screen 102 into the module 3 , followed by inserting the storm window 104 over the ventilation screen 102 and into the module 3 .
[0055] In inclement or cold weather the double pane storm window 104 when installed, permits light to pass through but prevents outside cold air from infiltrating. When exposure to outside air is desired, the sliding patio door 21 is moved back away from the trailing edge of the pet door panel 25 . Next, the storm windows 104 in the top and center modules 2 , 3 , respectively, of the pet door panel 25 are removed by pulling them back and sliding them out of the associated channels. The sliding patio door 21 is then closed against the trailing edge of the pet door panel 25 , and secured to prevent unwanted passage of people, animals, insects, etc. FIG. 11 shows the pet door panel 25 of FIG. 1 , but having screens 102 and storm windows 104 installed in each of the top and center modules 2 , 3 , respectively.
[0056] The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying claims, that various changes, modifications, and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
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A pet door panel or module is configured to include a pocket window opening having an open side portion to permit a ventilation screen to be slid into the pocket on centrally located tracks to provide ventilation means, and to further permit dual panel storm window means to be slid into the pocket via tracks on either side of the centrally located track to enclose the screen between the window panes to prevent air from flowing through the window opening to protect from foul weather and insulate from cold outside temperatures.
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[0001] The present invention pertains to a filtering face-piece respirator that uses an exhalation valve that is integrally secured to the mask body support structure.
BACKGROUND
[0002] Respirators are commonly worn over the breathing passages of a person for at least one of two common purposes: (1) to prevent impurities or contaminants from entering the wearer's breathing track; and (2) to protect other persons or things from being exposed to pathogens and other contaminants exhaled by the wearer. In the first situation, the respirator is worn in an environment where the air contains particles that are harmful to the wearer, for example, in an auto body shop. In the second situation, the respirator is worn in an environment where there is risk of contamination to other persons or things, for example, in an operating room or clean room.
[0003] Some respirators are categorized as being “filtering face-pieces” because the mask body itself functions as the filtering mechanism. Unlike respirators that use rubber or elastomeric mask bodies in conjunction with attachable filter cartridges (see, e.g., U.S. Pat. No. RE39,493 to Yuschak et al.) or insert-molded filter elements (see, e.g., U.S. Pat. No. 4,790,306 to Braun), filtering face-piece respirators have the filter media comprise much of the whole mask body so that there is no need for installing or replacing a filter cartridge. As such, filtering face-piece respirators are relatively light in weight and easy to use. Examples of patents that disclose filtering face-piece respirators include U.S. Pat. No. 7,131,442 to Kronzer et al, U.S. Pat. Nos. 6,923,182 and 6,041,782 to Angadjivand et al. U.S. Pat. Nos. 6,568,392 and 6,484,722 to Bostock et al., U.S. Pat. No. 6,394,090 to Chen, and U.S. Pat. No. 4,873,972 to Magidson et al.
[0004] To provide a filtering face-piece respirator that has a permanent cup-shaped configuration, the mask body is typically provided with a molded shaping layer. Molded shaping layers have been made from thermally bonded fibers or open-work filamentary meshes, which are molded into the cup-shaped configuration—see, for example, U.S. Pat. No. 4,850,347 to Skov, U.S. Pat. No. 4,807,619 to Dyrud et al., U.S. Pat. No. 4,536,440 to Berg, and U.S. Pat. No. Des. 285,374 to Huber et al. The shaping layers regularly support a filtering structure that may include an electrically-charged, nonwoven web of microfibers.
[0005] To improve wearer comfort, filtering face-piece respirators sometimes have an exhalation valve mounted to the mask body to rapidly purge the wearer's exhaled air from the mask interior; see U.S. Pat. Nos. 7,028,689, 7,188,622, and 7,013,895 to Martin et al. and U.S. Pat. Nos. 7,117,868, 6,854,463, and 6,843,248 to Japuntich et al., and U.S. Pat. No. RE37,974 to Bowers. The quick removal of exhaled air from the mask interior improves wearer comfort.
[0006] Exhalation valves have been mounted to respirator mask bodies using a variety of techniques. In some respirators, the valve is welded directly to the various layers that comprise the mask body. In other constructions, the valve seat is clamped to the mask body; see U.S. Pat. Nos. 7,069,931, 7,007,695, 6,959,709, and 6,604,524 to Curran et al. Additionally, a printed patch of adhesive has been used to secure the exhalation valve to the mask body; see U.S. Pat. No. 6,125,849 to Williams et al. In each of these various techniques, the valve is made separately from the mask body and is subsequently attached to the fibrous media and/or open-work filamentary mesh that comprises the mask body.
SUMMARY OF THE INVENTION
[0007] The present invention provides a new construction for securing an exhalation valve to the mask body of a filtering face-piece respirator. In so doing, the present invention provides a filtering face-piece respirator that comprises: (a) a harness; (b) a mask body that comprises: (i) a filtering structure; (ii) a support structure; and (c) an exhalation valve that comprises a valve seat that is integral to the support structure.
[0008] As indicated above, conventional filtering face-piece respirators have secured the separately-constructed exhalation valve directly to the fibrous and open-work plastic structures of the mask body. The present invention makes the exhalation valve seat at the same time as the support structure and, as such, eliminates these additional manufacturing steps. In the present invention, there is no need to separately manufacture the valve seat or to mount the valve seat to the mask body.
[0009] Because mask bodies for conventional filtering face-piece respirators have regularly used shaping layers that comprised molded nonwoven webs of thermally-bonded fibers or an open-work filamentary mesh to provide structural integrity to the mask body, the ability to provide an exhalation valve integral to the mask body was lacking In one embodiment, the present invention provides a mask body support structure that has one or more cross members that allow the valve seat to be firmly part of the mask body. The valve seat can be integrally attached to one or more cross members to provide a new and improved support structure.
GLOSSARY
[0010] The terms set forth below will have the meanings as defined:
[0011] “bisect(s)” means to divide into two generally equal parts;
[0012] “centrally spaced” means separated significantly from one another along a line or plane that bisects the mask body;
[0013] “comprises (or comprising)” means its definition as is standard in patent terminology, being an open-ended term that is generally synonymous with “includes”, “having”, or “containing” Although “comprises”, “includes”, “having”, and “containing” and variations thereof are commonly-used, open-ended terms, this invention also may be suitably described using narrower terms such as “consists essentially of”, which is semi open-ended term in that it excludes only those things or elements that would have a deleterious effect on the performance of the inventive respirator in serving its intended function;
[0014] “clean air” means a volume of atmospheric ambient air that has been filtered to remove contaminants;
[0015] “contaminants” means particles (including dusts, mists, and fumes) and/or other substances that generally may not be considered to be particles (e.g., organic vapors, bacteria, et cetera) but which may be suspended in air, including air in an exhale flow stream;
[0016] “cross member” means a solid part that extends at least partially across (transversely (side-to-side) or longitudinally (vertically))the mask body;
[0017] “crosswise dimension” is the dimension that extends laterally across the respirator from side-to-side when the respirator is viewed from the front;
[0018] “exhalation valve” means a valve that opens to allow exhaled air to exit a filtering face mask's interior gas space;
[0019] “exterior gas space” means the ambient atmospheric gas space into which exhaled gas enters after passing through and beyond the mask body and/or exhalation valve;
[0020] “filtering face-piece” means that the mask body itself is designed to filter air that passes through it; there are no separately identifiable filter cartridges or inserted-molded filter elements attached to or molded into the mask body to achieve this purpose;
[0021] “filter” or “filtration layer” means one or more layers of air-permeable material, which layer(s) is adapted for the primary purpose of removing contaminants from an air stream that passes through it;
[0022] “filtering structure” means a construction that is designed primarily for filtering air;
[0023] “first side” means an area of the mask body that is laterally distanced from a plane that bisects the mask vertically and that would reside in the region of a wearer's cheek and/or jaw when the respirator is being donned;
[0024] “flexible flap” means a sheet-like article that is capable of bending or flexing in response to a force exerted from an exhale gas stream;
[0025] “harness” means a structure or combination of parts that assists in supporting the mask body on a wearer's face;
[0026] “hinder movement” means to deprive of significant movement when exposed to forces that exist under normal use conditions;
[0027] “integral” means being manufactured together at the same time—that is, being made together as one part and not two separately manufactured parts that are subsequently joined together;
[0028] “interior gas space” means the space between a mask body and a person's face;
[0029] “line of demarcation” means a fold, seam, weld line, bond line, stitch line, hinge line, and/or any combination thereof;
[0030] “living hinge” means a mechanism that allows members that extend therefrom to generally pivot thereabout in a rotational-type manner with such ease that damage is not caused to the members or to the hinge joint under normal use;
[0031] “mask body” means an air-permeable structure that is designed to fit over the nose and mouth of a person and that helps define an interior gas space separated from an exterior gas space;
[0032] “perimeter” means the outer edge of the mask body, which outer edge would be disposed generally proximate to a wearer's face when the respirator is being donned by a person;
[0033] “pleat” means a portion that is designed to be folded back upon itself;
[0034] “pleated” means being folded back upon itself;
[0035] “polymeric” and “plastic” each mean a material that mainly includes one or more polymers and may contain other ingredients as well;
[0036] “plurality” means two or more;
[0037] “respirator” means an air filtration device that is worn by a person to provide the wearer with clean air to breathe;
[0038] “rigid” means the part does not readily deform substantially and easily in response to mere pressure from a person's finger.
[0039] “seal surface” means a surface onto which the flexible flap makes contact when the valve is in its closed position;
[0040] “second side” means an area of the mask body that is distanced from a plane line that bisects the mask vertically (the second side being opposite the first side) and that would reside in the region of a wearer's cheek and/or jaw when the respirator is being donned;
[0041] “support structure” means a construction that is designed to have sufficient structural integrity to retain its desired shape and to help retain the intended shape of the filtering structure that is supported by it, under normal handling;
[0042] “spaced” means physically separated or having measurable distance therebetween;
[0043] “transversely extending” means extending generally in the crosswise dimension;
[0044] “valve base” means the portion of the exhalation valve that includes the seal surface and that is joined to the mask body; and
[0045] “valve seat” means the portion of the exhalation valve that includes the seal surface and the valve base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 shows a front perspective view of a filtering face-piece respirator 10 , in accordance with the present invention, being worn on a person's face;
[0047] FIGS. 2 a and 2 b are cross-sectional views of an exhalation valve 28 integrally secured to a support structure 16 in accordance with the present invention;
[0048] FIG. 3 is a front view of a mask body 12 that has a valve seat 38 integral to a support structure 16 in accordance with the present invention;
[0049] FIG. 4 is a front view of a mask body 12 that has an exhalation valve 28 integrally joined to the support structure 16 at the valve seat 38 ;
[0050] FIG. 5 is a cross-sectional view taken along lines 5 - 5 of FIG. 2 b through the filtering structure 18 , which may be used in a mask body 12 of the present invention.
[0051] FIG. 6 is a perspective view of a filtering structure 18 that may be used in a mask body of the present invention; and
[0052] FIG. 7 is a plan view of a blank that may be used to form the filtering structure 18 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0053] In practicing the present invention, a filtering face-piece respirator is provided that has an exhalation valve seat that is integral to the support structure of the mask body. Rather than mount the valve seat to a shaping layer that comprises thermally-bonded fibers or an open-work plastic mesh, the present invention integrally joins the valve seat to the support structure itself. When the valve seat is integrally joined to the support structure, there is no need to separately manufacture the valve seat or to mechanically secure it to the mask body.
[0054] FIG. 1 shows an example of a shaped filtering face-piece respirator 10 that may be used in accordance with the present invention. As illustrated, the filtering face-piece respirator 10 includes a mask body 12 and a harness 14 . The mask body 12 has a support structure 16 and a filtering structure 18 . The support structure 16 includes a perimeter 20 , a first side 22 , and an opposing second side 24 . The perimeter 20 of the support structure 16 may, but not necessarily, contact the wearer's face when the respirator 10 is being donned. The perimeter 20 may comprise a member, or combination of members, that extend 360° continuously about, and adjacent to, the periphery of the mask body 12 . Typically, the wearer's face will contact only the inner surface or periphery of the filtering structure 18 —or an additional face seal material—so that a comfortable fit is achieved. Thus, the peripheral edge of the filtering structure 18 may extend slightly radially beyond the support structure perimeter 20 . The mask body 12 also may include cross members 25 and 27 that transversely extend across the mask body 12 . As illustrated, these transversely-extending cross members 25 and 27 extend from a first side 22 of the respirator to a second side 24 . The invention, however, contemplates embodiments where the cross members do not need to extend fully across the mask body 12 but extend only partially across it. The use of cross members that extend from a first side 22 to a second side 24 may provide a support structure 16 that has very good structural stability and therefore may be preferred in conjunction with the present invention but may not be necessary for providing a structure onto which an exhalation valve 28 may be integrally secured. The cross members also could, for example, extend partially or fully across the mask body 12 in the longitudinal direction. To readily fashion the valve 28 or portions thereof at the same time as, or “integral” with, the support structure 16 , the support structure 16 may comprise a plurality of cross members that help define the mask body shape, while at the same time support the valve 28 and the filtering structure 18 .
[0055] The support structure 16 also may include a longitudinally-movable, transversely-extending member 30 . This longitudinally-movable, transversely-extending member 30 can extend from a first side 22 of the mask body 12 to a second side 24 , preferably without being joined together between sides 22 and 24 by any longitudinally-extending member(s) that could hinder movement of the transversely-extending members 30 in a longitudinal direction. That is, there preferably is no structural member that joins member 30 to member 27 so as to restrict member 30 from moving away from member 27 when the wearer expands their jaw or opens their mouth. When viewing the respirator as projected onto a plane from the front, the transverse direction is the direction that extends across the respirator in the general “x” direction, and the longitudinal direction is the dimension that extends between the bottom and top of the respirator 10 in the general “y” direction. When viewed through such a planar projection, the transversely-extending member 30 can move towards and away from member 27 in the general “y” direction. The use of a longitudinally-movable member 30 may allow the mask body 12 to expand to better accommodate wearer jaw movement and various sized faces—see U.S. Patent Application Ser. No. 60/974,025 (attorney docket number 63165US002) entitled Filtering Face-Piece Respirator That Has Expandable Mask Body, filed on Sep. 20, 2007.
[0056] The respirator 10 is supported on the face of the wearer by a harness 14 that may include first and second straps 32 a and 32 b. These straps 32 a, 32 b may be adjusted in length by one or more buckles 34 . The buckles 34 may be secured to the mask body 12 at the first and second sides 22 , 24 at harness-securement flange members 36 a, 36 b using a variety of methods, including stapling, adhesive bonding, welding, and the like. The buckles 34 also may be integrally molded into the support structure 16 ; see, U.S. Patent Application U.S. Ser. No. 60/974,031 (attorney docket number 63355US002) entitled Filtering Face-Piece Respirator Having Buckles Integral To The Mask Body, filed on Sep. 20, 2007. The thickness of the harness flanges 36 a, 36 b typically may be about 2 to 3 mm.
[0057] FIGS. 2 a and 2 b show the exhalation valve 28 secured to the support structure 16 at the valve seat 38 in cross-section. The valve seat 38 includes a valve base 40 that is integrally joined to the support structure 16 at cross members 25 and 27 . The exhalation valve 28 also has a valve cover 42 that resides over the valve seat 38 to define an air chamber 43 through which exhaled air passes before exiting the valve 28 at valve cover opening(s) 44 . The exhalation valve 28 also has a flexible flap 46 that lifts from a seal surface 48 in response to exhalation pressure generated by a respirator wearer during an exhalation. In FIG. 2 a, the valve seat has a curved seal surface 48 , whereas in FIG. 2 b the seal surface is generally planar when viewed from the side. The flap may be made from known flexible materials (see, e.g., U.S. Pat. No. 6,854,463 to Japuntich et al. and U.S. Pat. No. 7,028,689 to Martin et al.) and may take on a variety of sheet-like shapes (see, e.g., U.S. Pat. No. 6,883,518 to Mittelstadt et al.).
[0058] FIG. 3 shows a front view of a mask body 12 where the valve cover ( 42 , FIGS. 2 a and 2 b ) and the flexible flap ( 46 , FIGS. 2 a and 2 b ) have been removed so that the valve seat 38 is more visible. As shown, the valve seat 38 includes a seal surface 48 and an aperture 50 . Although the seal surface 48 and aperture 50 are both illustrated as being circular, they may independently take on a variety of other configurations including rectangular, elliptical, etc. The aperture 50 allows exhaled air to pass from the interior gas space through the valve to ultimately enter the exterior gas space. When viewed from the front as shown in FIG. 3 , the seal surface 48 surrounds the aperture 50 . One or more orifice dividers 52 may be employed within the aperture 50 to provide a plurality of openings 54 within the whole aperture 50 . One or more valve posts 56 or other means may be provided in the valve seat 38 to allow for the proper alignment of the flexible flap ( 46 , FIGS. 2 a and 2 b ) when secured to the valve seat 38 .
[0059] Exhalation valves that are integrally attached to the support structure in accordance with the present invention may have a construction similar to the unidirectional valves described in U.S. Pat. Nos. 7,188,622, 7,028,689, and 7,013,895 to Martin et al.; U.S. Pat. Nos 7,117,868, 6,854,463, 6,843,248, and 5,325,892 to Japuntich et al.; U.S. Pat. No. 6,883,518 to Mittelstadt et al.; and U.S. Pat. No. RE37,974 to Bowers. A valve cover also can be molded integral to the valve seat in a hinged manner such that it only needs to be rotated into engagement with the valve seat to be fully secured thereto by frictional and/or mechanical or adhesive fasteners—see U.S. Pat. No. 6,047,698. Examples of valve cover designs are shown in U.S. Pat. Nos Des. 347,298 to Japuntich et al. and U.S. Pat. No. Des. 347,299 to Bryant et al. Essentially any exhalation valve that provides a suitable pressure drop and that can be integrally secured to the support structure may be used in connection with the present invention.
[0060] The valve base typically is sized to encompass an area (measured from its outer dimensions), when viewed from the front, that is less than about 25 square centimeters (cm 2 ). More typically, the base is sized to encompass an area typically less than about 16 cm 2 . When a flapper or cantilevered-style valve is used (see, for example, U.S. Pat. No. 5,509,436 to Japuntich et al., and U.S. Pat. No. 6,047,698 to Magidson et al.), the valve base may be longer in the longitudinal dimension than in the cross-wise dimension. Typically, the members that comprise the base are less than 1 cm thick. The thickness of the base member(s) typically is greater than 2 mm and is less than 5 mm. More typically, the thickness of the base member(s) is about 2 to 4 mm. The valve base typically occupies an area of about 2 to 10 cm 2 , more typically about 3 to 7 cm 2 . The base preferably extends continuously 360° about an opening in the mask body. The mask body opening, and hence the valve seat, preferably are located directly in front of where the wearer's mouth would be when the respirator is being donned. The thickness of the cross-members of the support structure may be about 0.25 to 5 mm, more typically about 1 to 3 mm. The thickness of the harness flanges 36 a, 36 b typically may be about 2 to 3 mm.
[0061] The valve seat and/or support structure may be made by known techniques such as injection molding. Known plastics such as olefins including, polyethylene, polypropylene, polybutylene, and polymethyl(pentene); plastomers; thermoplastics; thermoplastic elastomers; and blends thereof may be used to make the frame and/or support structure. Additives such as pigments, UV stabilizers, anti-block agents, nucleating agents, fungicides, and bactericides also may be added to the composition that forms the frame and/or support structure. The plastic typically exhibits a stiffness in flexure of about 75 to 300 Mega Pascals (MPa), more typically about 100 to 250 MPa, and still typically about 175 to 225 MPa. A metal or ceramic material also may be used in lieu of plastic to construct the valve seat and/or support structure, although a plastic may be preferred for disposal/cost/flexibility reasons.
[0062] A plastic used for the valve seat and/or support structure can be selected to exhibit resilience, shape memory, and resistance to flexural fatigue so that the support structure can be deformed many times (i.e. greater than 100), particularly at any hinge points, and return to its original position. The plastic selected should be able to withstand an indefinite number of deformations so that the support structure exhibits a greater service life than the filter structure. The support structure is a part or assembly that is not integral to (or made together with) the filtering structure and comprises members that are sized to be larger than the fibers used in the filtering structure. The support structure members may be rectangular, circular, triangular, elliptical, trapezoidal, etc., when viewed in cross-section. The valve seat preferably is rigid in structure so that the seal surface maintains its desired configuration. Although the valve seat desirously is rigid in structure, the cross members onto which the valve seat is joined may be sufficiently flexible to enable the mask body to conform to the wearer's face and to allow it to return to its desired configuration when deformed from, for example, striking another object during use.
[0063] FIG. 4 shows that a valve cover 42 may be placed over the valve seat 38 . The valve cover 42 may be integrally joined to the valve seat along one edge in a hinged manner or may be glued, welded, mechanically joined, or secured thereto by a combination of such means. The valve cover and the valve seat therefore may be made as a single part. Examples of valve covers that may be used are shown in U.S. Pat. Nos. Des. 347,298 and Des. 347,299. The valve cover may include one or more surfaces that mechanically secure the flexible flap to the valve seat 38 . The valve cover may be made from similar or different materials than the valve seat but typically will be made from the same rigid plastic.
[0064] FIG. 5 shows a cross-section of an example of a filtering structure 18 that may be used in connection with the present invention. As illustrated, the filtering structure 18 may include one or more cover webs 70 a and 70 b and a filtration layer 72 . The cover webs 70 a and 70 b may be located on opposing sides of the filtration layer 72 to capture any fibers that could come loose therefrom. Typically, the cover webs 70 a and 70 b are made from a selection of fibers that provide a comfortable feel, particularly on the side of the filtering structure 18 that makes contact with the wearer's face. The construction of various filter layers and cover webs that may be used in conjunction with the support structure of the present invention are described below in more detail.
[0065] FIG. 6 shows a perspective view of one example of a filtering structure 18 that can be used in a respirator of the present invention. The filtering structure 18 may include a first and second transversely-extending lines of demarcation 74 a and 74 b. These lines of demarcation 74 a, 74 b may be substantially spaced from one another in the central portion of the filtering structure 18 but may converge towards each other, moving laterally in the direction of the sides 76 and 78 . The lines of demarcation 74 a, 74 b may comprise a fold, weld line, stitch line, bond line, hinge line, or combination thereof. Generally, the first and second lines of demarcation 74 a and 74 b correspond to the location of certain cross members on the support structure. When the first and second lines of demarcation 74 a, 74 b define a pleat 80 that may be formed therebetween, the first and second lines of demarcation 74 a, 74 b preferably are secured to transversely-extending members 27 and 30 , respectively, thereby allowing the filtering structure to open and close in an accordion-like manner about the pleat 80 that is located therebetween. The filtering structure 18 also includes a generally vertical line of demarcation 82 that may be provided in the nose region of the filtering structure to eliminate excess material that would otherwise accumulate in the nose region during the manufacturing process. Although the filtering structure 18 has been illustrated with only a single pleat 80 , the filtering structure 18 may include two or more of such pleats in the cross-wise dimension. Under such circumstances, it is preferable to provide a support structure that has multiple living hinges where the movable transversely-extending members meet. To improve fit and wearer comfort, an elastomeric face seal can be secured to the perimeter 86 of the filtering structure 18 . Such a face seal may extend radially inward to contact the wearer's face when the respirator is being donned. The face seal may be made from a thermoplastic elastomer. Examples of face seals are described in U.S. Pat. No. 6,568,392 to Bostock et al., U.S. Pat. No. 5,617,849 to Springett et al., U.S. Pat. No. 4,600,002 to Maryyanek et al., and in Canadian Patent 1,296,487 to Yard.
[0066] The filtering structure may take on a variety of different shapes and configurations. The filtering structure typically is adapted so that it properly fits against or within the support structure. Generally the shape and configuration of the filtering structure corresponds to the general shape of the support structure. The filtering structure may be disposed radially inward from the support structure, it may be disposed radially outward from the support structure, or it may be disposed between various members that comprise the support structure. Although a filtering structure has been illustrated with multiple layers that include a filtration layer and two cover webs, the filtering structure may simply comprise a filtration layer or a combination of filtration layers. For example, a pre-filter may be disposed upstream to a more refined and selective downstream filtration layer. Additionally, sorptive materials such as activated carbon may be disposed between the fibers and/or various layers that comprise the filtering structure. Further, separate particulate filtration layers may be used in conjunction with sorptive layers to provide filtration for both particulates and vapors. The filtering structure may include one or more stiffening layers that allow such a cup-shaped configuration to be maintained. Alternatively, the filtering structure could have one or more horizontal and/or vertical lines of demarcation that contribute to its structural integrity to help maintain the cup-shaped configuration.
[0067] The filtering structure that is used in a mask body of the invention can be of a particle capture or gas and vapor type filter. The filtering structure also may be a barrier layer that prevents the transfer of liquid from one side of the filter layer to another to prevent, for instance, liquid aerosols or liquid splashes from penetrating the filter layer.
[0068] Multiple layers of similar or dissimilar filter media may be used to construct the filtering structure of the invention as the application requires. Filters that may be beneficially employed in a layered mask body of the invention are generally low in pressure drop (for example, less than about 195 to 295 Pascals at a face velocity of 13.8 centimeters per second) to minimize the breathing work of the mask wearer. Filtration layers additionally are flexible and have sufficient shear strength so that they generally retain their structure under expected use conditions. Examples of particle capture filters include one or more webs of fine inorganic fibers (such as fiberglass) or polymeric synthetic fibers. Synthetic fiber webs may include electret charged polymeric microfibers that are produced from processes such as meltblowing. Polyolefin microfibers formed from polypropylene that has been electrically charged provide particular utility for particulate capture applications. An alternate filter layer may comprise a sorbent component for removing hazardous or odorous gases from the breathing air. Sorbents may include powders or granules that are bound in a filter layer by adhesives, binders, or fibrous structures—see U.S. Pat. No. 3,971,373 to Braun. A sorbent layer can be formed by coating a substrate, such as fibrous or reticulated foam, to form a thin coherent layer. Sorbent materials may include activated carbons that are chemically treated or not, porous alumina-silica catalyst substrates, and alumina particles. An example of a sorptive filtration structure that may be conformed into various configurations is described in U.S. Pat. No. 6,391,429 to Senkus et al.
[0069] The filtration layer is typically chosen to achieve a desired filtering effect and, generally, removes a high percentage of particles and/or or other contaminants from the gaseous stream that passes through it. For fibrous filter layers, the fibers selected depend upon the kind of substance to be filtered and, typically, are chosen so that they do not become bonded together during the molding operation. As indicated, the filtration layer may come in a variety of shapes and forms and typically has a thickness of about 0.2 millimeters (mm) to 1 centimeter (cm), more typically about 0.3 mm to 0.5 cm, and it could be a generally planar web or it could be corrugated to provide an expanded surface area—see, for example, U.S. Pat. Nos. 5,804,295 and 5,656,368 to Braun et al. The filtration layer also may include multiple filtration layers joined together by an adhesive or any other means. Essentially any suitable material that is known (or later developed) for forming a filtering layer may be used for the filtering material. Webs of melt-blown fibers, such as those taught in Wente, Van A., Superfine Thermoplastic Fibers, 48 Indus. Engn. Chem., 1342 et seq. (1956), especially when in a persistent electrically charged (electret) form are especially useful (see, for example, U.S. Pat. No. 4,215,682 to Kubik et al.). These melt-blown fibers may be microfibers that have an effective fiber diameter less than about 20 micrometers (μm) (referred to as BMF for “blown microfiber”), typically about 1 to 12 μm. Effective fiber diameter may be determined according to Davies, C. N., The Separation Of Airborne Dust Particles, Institution Of Mechanical Engineers, London, Proceedings 1B, 1952. Particularly preferred are BMF webs that contain fibers formed from polypropylene, poly(4-methyl-1-pentene), and combinations thereof. Electrically charged fibrillated-film fibers as taught in van Turnhout, U.S. Pat. No. Re. 31,285, may also be suitable, as well as rosin-wool fibrous webs and webs of glass fibers or solution-blown, or electrostatically sprayed fibers, especially in microfilm form. Electric charge can be imparted to the fibers by contacting the fibers with water as disclosed in U.S. Pat. No. 6,824,718 to Eitzman et al., U.S. Pat. No. 6,783,574 to Angadjivand et al., U.S. Pat. No. 6,743,464 to Insley et al., U.S. Pat. Nos. 6,454,986 and 6,406,657 to Eitzman et al., and U.S. Pat. Nos. 6,375,886 and 5,496,507 to Angadjivand et al. Electric charge also may be imparted to the fibers by corona charging as disclosed in U.S. Pat. No. 4,588,537 to Klasse et al. or by tribocharging as disclosed in U.S. Pat. No. 4,798,850 to Brown. Also, additives can be included in the fibers to enhance the filtration performance of webs produced through the hydro-charging process (see U.S. Pat. No. 5,908,598 to Rousseau et al.). Fluorine atoms, in particular, can be disposed at the surface of the fibers in the filter layer to improve filtration performance in an oily mist environment—see U.S. Pat. Nos. 6,398,847 B1, 6,397,458 B1, and 6,409,806 B1 to Jones et al. Typical basis weights for electret BMF filtration layers are about 10 to 100 grams per square meter. When electrically charged according to techniques described in, for example, the '507 patent, and when including fluorine atoms as mentioned in the Jones et al. patents, the basis weight may be about 20 to 40 g/m 2 and about 10 to 30 g/m 2 , respectively.
[0070] An inner cover web can be used to provide a smooth surface for contacting the wearer's face, and an outer cover web can be used to entrap loose fibers in the mask body or for aesthetic reasons. The cover web typically does not provide any substantial filtering benefits to the filtering structure, although it can act as a pre-filter when disposed on the exterior (or upstream to) the filtration layer. To obtain a suitable degree of comfort, an inner cover web preferably has a comparatively low basis weight and is formed from comparatively fine fibers. More particularly, the cover web may be fashioned to have a basis weight of about 5 to 50 g/m 2 (typically 10 to 30 g/m 2 ), and the fibers are less than 3.5 denier (typically less than 2 denier, and more typically less than 1 denier but greater than 0.1). Fibers used in the cover web often have an average fiber diameter of about 5 to 24 micrometers, typically of about 7 to 18 micrometers, and more typically of about 8 to 12 micrometers. The cover web material may have a degree of elasticity (typically, but not necessarily, 100 to 200% at break) and may be plastically deformable.
[0071] Suitable materials for the cover web are blown microfiber (BMF) materials, particularly polyolefin BMF materials, for example polypropylene BMF materials (including polypropylene blends and also blends of polypropylene and polyethylene). A suitable process for producing BMF materials for a cover web is described in U.S. Pat. No. 4,013,816 to Sabee et al. The web may be formed by collecting the fibers on a smooth surface, typically a smooth-surfaced drum. Spun-bond fibers also may be used.
[0072] A typical cover web may be made from polypropylene or a polypropylene/polyolefin blend that contains 50 weight percent or more polypropylene. These materials have been found to offer high degrees of softness and comfort to the wearer and also, when the filter material is a polypropylene BMF material, to remain secured to the filter material without requiring an adhesive between the layers. Polyolefin materials that are suitable for use in a cover web may include, for example, a single polypropylene, blends of two polypropylenes, and blends of polypropylene and polyethylene, blends of polypropylene and poly(4-methyl-1-pentene), and/or blends of polypropylene and polybutylene. One example of a fiber for the cover web is a polypropylene BMF made from the polypropylene resin “Escorene 3505G” from Exxon Corporation, providing a basis weight of about 25 g/m 2 and having a fiber denier in the range 0.2 to 3.1 (with an average, measured over 100 fibers of about 0.8). Another suitable fiber is a polypropylene/polyethylene BMF (produced from a mixture comprising 85 percent of the resin “Escorene 3505G” and 15 percent of the ethylene/alpha-olefin copolymer “Exact 4023” also from Exxon Corporation) providing a basis weight of about 25 g/m 2 and having an average fiber denier of about 0.8. Suitable spunbond materials are available, under the trade designations “Corosoft Plus 20”, “Corosoft Classic 20” and “Corovin PP-S-14”, from Corovin GmbH of Peine, Germany, and a carded polypropylene/viscose material available, under the trade designation “370/15”, from J. W. Suominen OY of Nakila, Finland.
[0073] Cover webs that are used in the invention preferably have very few fibers protruding from the web surface after processing and therefore have a smooth outer surface. Examples of cover webs that may be used in the present invention are disclosed, for example, in U.S. Pat. No. 6,041,782 to Angadjivand, U.S. Pat. No. 6,123,077 to Bostock et al., and WO 96/28216A to Bostock et al.
EXAMPLE
Test Methods
1. Stiffness in Flexure Test (SFT)
[0074] The stiffness in flexure of material used to make the support structure was measured according to ASTM D 5342-97 section 12.1 to 12.7. In so doing, six test specimens were cut from a blank film into rectangular pieces that were about 25.4 mm wide by about 70 mm long. The specimens were prepared as described below. Taber V-5 Stiffener tester Model 150-E (from Taber Corporation, 455 Bryant Street, North Tonawanda, N.Y., 14120) was used in 10-100 Taber stiffness unit configurations to measure the test specimens. The Taber Stiffness readings were recorded from the equipment display at the end of the test, and the stiffness in flexure was calculated using the following equation:
[0000]
Stiffness
in
Flexure
(
Pa
)
=
7
,
492
Ncm
4
M
2
(
Tabar
Stiffness
Width
*
thickness
3
)
Taber Stiffness=recorded material resistance to bending measured according to ASTM D5342-97 section 12.1 to 12.7.
Width=width of test film specimen in cm, which was 2.54 cm.
Thickness=average thickness of test specimen in cm measured using standard digital caliper at five equally-spaced locations along the length, of the material.
The stiffness in flexure from the six samples were averaged to give the Stiffness in Flexure.
Sample Preparation
[0078] 1. Stiffness in Flexure Test Specimen
[0079] Test specimens for the Stiffness in Flexure Test can be prepared from the same compounded polymer ingredients that can be blended together to make the respirator support structure. See Table 2 for an example of the polymeric composition of the support structure. Forty (40) grams of the compound were used to make a circular film that was 114 mm in radius and 0.51 to 0.64 mm thick. The first 40 grams of the compounded material was poured into a twin screw roller blade Type Six BRABENDER mixer (from C.W. Brabender instruments Inc., 50 East Wesley Street, P.O. Box 2127, South Hackensack, N.J., 07606). The mixer was operating at 75 revolutions per minute (RPM) and at a temperature of 185° C. After blending the molten compound for about 10 minutes, the mixture was pressed under 44.5 kilonewtons (KN) of force to make the 0.51 to 0.64 mm thick flat circular film that was 114 mm in diameter. The compression was conducted using a hot platen set at 149 ° C. The hot platen was a Genesis 30 ton Compression molding press from WABASH Equipments 1569 Morris Street, P.O. Box 298, Wabash, Ind. 46992. Before testing for stiffness in flexure, the films were cut to the required test specimen sizes of 25.4 mm wide by 70 mm long.
[0080] 2. Respirator Support Structure Manufacture
[0081] Samples of the respirator support structure can be made using a standard injection molding process. Single cavity male and female molds, generally matching the geometry of the support structure shown in FIGS. 1 , 3 , and 4 can be made at a tool manufacturer. At a relaxed state, or while the support structure is still on the mold, the support structure can measure 115 mm, top to bottom, and 120 mm from side to side. The measurement can be made along a direct line between the highest and lowest points on the perimeter and two living hinge points, respectively while the respirator is in an unstressed state. The targeted thickness of the members that comprise the support structure is about 2.5 millimeters. The transversely-extending members may be given a trapezoidal cross-section to allow the support structure to be more easily removed from the mold. The cross-sectional area of the transversely-extending members may range from about 7.5 to 12 mm 2 . The valve seat can be integrally joined to the support structure at the centrally-located cross members through use of a mold that makes the support structure and valve seat contemporaneously.
[0082] A 110 Ton Toshiba VIS-6 molding press can be used during the injection molding process to make the support structure under the conditions and set points shown in Table 1:
[0000]
TABLE 1
Respirator Support Structure Injection Molding Conditions
Process Condition
Set Point
Unit
Cycle time
40
Sec
Injection time
3
Sec
Fill Time
0.86
Sec
Charge Time
1-2
Sec
Cooling Time
12
Sec
Injection Pressure
276
MPa
Barrel temperature
204
Degree C.
(nozzle, front, center and
rear)
[0083] A compounding of polymers listed in Table 2 below at the specified weight percentages can be mixed to obtain the desired physical properties of the support structure.
[0000]
TABLE 2
Support Structure Composition
Weight %
Tradename
Material Type
Supplier
39.72%
Engage 8490
Polyolefin
Dupont Dow Elastomers L.L.C.,
Elastomer:
Bellvue Park Corporate Center,
ethylene-octene
300 Bellevue Parkway,
copolymer
Wilmington, DE 19809
39.72%
Hypel PELLD 20
Linear Low
Entec Polymers L.L.C., 2301
Density
Maitland Center Parkway, Suite
Polyethylene
240, Maitland, FL 32751
14.02%
Kraton G1657
Thermoplastic
Kraton Polymers LLC, 700
Elastomer:
Milma, North Tower, 13 th Floor,
styrene-ethylene-
Houston, TX 77002
butylene-styrene
block copolymer
0.93%
Atmer 1753
Erucamide
Unichema North America, 4650
South Racine Avenue, Chicago,
IL 60609-3321
5.61%
Silver Pigment
Pigment
Clariant Masterbatches, 9101
International Parkway,
Minneapolis, MN 55428
UN 5001
Pigment
Clariant Masterbatches, 17
Omnicolor Blue Dye*
Holden Industrial park
Holden, MA 01520
*Comprised less than 1 wt. % of the total composition.
[0084] 3. Respirator Filtering Structure Manufacture
[0085] Respirator filtering structures were formed from two layers of nonwoven fibrous electret filter material that was 254 mm wide, laminated between one 50 grams per square meter (gsm) outer layer of white nonwoven fibrous spunbond material and one 22 gsm inner layer of white nonwoven fibrous spunbond material having the same width. Both layers of the nonwoven fibrous spunbond materials were made of polypropylene. The electret filter material was the standard filter material that is used in a 3M 8511 N95 respirator. The laminated web blank was cut into the 254 mm long pieces to form a square before being formed into a cup formation that had a three-dimension (3D) pleat extending transversely across the filtering structure.
[0086] As shown in FIG. 7 , where the dotted lines represent fold lines and the solid lines represent weld (or the lines of demarcation 74 a and 74 b in FIG. 7 ), the complex 3D pleat ( 80 , FIG. 6 ) was formed by ultrasonically welding two curves 74 a, 74 b of same radius of curvature (258.5 mm radius). The distance between the highest points on each curve was 40 mm, and the two ends of the curves met at left and right end points, which were about 202 mm apart. The first curve 74 b was created by folding the laminated filter media along the first fold line 90 at least 76 mm away from one edge of laminated web. The second curve 74 a was formed by welding along the secondary curve line by folding the laminated web at a secondary fold line 92 , which is located 62 mm from the first fold line 90 . Once the two curves that make the 3D pleat are formed, excess material outside of the curve lines was removed. The layered material was then folded along the vertical center line 94 and a line of demarcation 82 ( FIG. 6 ) was welded, starting 51 mm away from the center of the second curve line as shown in FIG. 7 . This step removes any excess material and forms a cup that properly fits in the respirator support structure. An ultrasonic welding process was used to make the welds. Branson 2000ae Ultrasonic welding equipment and power supply was used at a peak power mode, 100% amplitude and air pressure of 483 MPa.
[0087] 4. Other Respirator Components
[0088] Face seal: Standard 3M 4000 Series respirator face seal.
[0089] Nose clip: Standard 3M 8210 Plus N 95 Respirator nose clip.
[0090] Headband: Standard 3M 8210 Plus N 95 Respirator headband material but white in color. The Yellow pigment for 3M 8210 Plus respirator headband was removed.
[0091] Buckle: A buckle similar to a back-pack buckle with flexible hinge to allow comfortable adjustment of headband material was used.
[0092] Exhalation Valve Cover: 3M Cool Flow™ valve cover from 8511 Respirator.
[0093] Exhalation Valve Flap: 3M Cool Flow™ flexible flap from an 8511 Respirator.
[0094] 5. Respirator Assembly
[0095] The face seal material was cut to pieces that were about 140 mm by 180 mm. A die cut tool was then used to create an oval opening that was 125 mm by 70 mm and was located in the center of the face seal. The face seal with the central cut out opening was attached to respirator filtering structure made as described above. The same equipment that was used to ultrasonically weld the filtering element structure was used to secure the face seal to the filtering structure under similar process conditions. The welding anvil had an oval shape of about 168 mm wide and 114 mm long. After the face seal was joined to the filtering structure, excess material outside of the weld line was removed. The nose clip was adhered to the outside of the assembled filtering structure crosswise over the nose area. Then the pre-assembled filtering element was inserted into the support structure in its desired orientation. The complex 3D pleat was strategically located between transversely extending members 27 and 30 shown in FIGS. 3 and 4 . A handheld Branson E-150 Ultrasonic welding equipment, at 100% output and 1.0 second weld time, was used to create attachment points between the support structure and the filtering structure at an interval of 20 to 25 mm along each transversely extending member. Four headband buckles were stapled to the harness flanges 36 a, 36 b using 12.7 mm Heavy Duty STANLEY staple wire on both sides of the support structure above and below the living hinge 96 . A 450 mm long braided headband material was threaded through the buckles to complete the respirator assembly process. The flexible flap was placed on the valve seat, and the valve cover was placed on top of the seat such that the flap became pressed between a flap-retaining surface on the valve seat and an opposing surface on the valve cover.
Stiffness in Flexure Test Results
[0096] The compounded ingredients listed in Table 2 were selected to match desired structural and flexibility properties needed for the support structure. The calculated stiffness in flexure for the support structure material is listed in Table 3 below:
[0000]
TABLE 3
Respirator Support Structure Material Stiffness in Flexure
Taber
Stiffness
Thickness
Stiffness
in Flexure
Specimen
(cm)
(g · cm)
(MPa)
1
0.0627
14.5
173
2
0.0594
16.9
230
3
0.0561
11.9
199
4
0.0508
9.3
209
5
0.0546
11.3
205
6
0.0541
10.7
196
Average
0.0563
12.4
202
Std
0.042
2.8
18.7
Deviation
[0097] The data set forth in Table 3 show that the Stiffness in Flexure of the support structure materials is about 200 MPa.
[0098] This invention may take on various modifications and alterations without departing from its spirit and scope. Accordingly, this invention is not limited to the above-described but is to be controlled by the limitations set forth in the following claims and any equivalents thereof.
[0099] This invention also may be suitably practiced in the absence of any element not specifically disclosed herein.
[0100] All patents and patent applications cited above, including those in the Background section, are incorporated by reference into this document in total. To the extent that there is a conflict or discrepancy between the disclosure in the incorporated document and the above specification, the above specification will control.
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A filtering face-piece respirator that has a harness and a mask body where the mask body includes a filtering structure and a support structure. An exhalation valve is attached to the mask body and includes a valve seat that is integral to the mask body. The present invention is beneficial in that it eliminates the need to separately manufacture some or all of the non-dynamic parts of the exhalation valve. There also is no need to subsequently attach the valve seat to the mask body.
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GOVERNMENT SUPPORT NOTICE
This invention was made with government support under Contract No. W56HZV-05-C-0724 and Subcontract No. 5EC8377H, awarded by the U.S. Army. The government has certain rights in the invention.
COPYRIGHT NOTICE
Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND
In remote teleoperation of unmanned ground vehicles (UGVs), an operator uses a joystick to point sensors and steer the vehicle. Commands from these joysticks and other control devices are communicated to the UGV via radio waves or other systems generally known in the art. These control signals are received by the UGV and used to control the UGV and/or its sensors and payloads, generally referred to herein as “onboard subsystems.” Very often the onboard subsystem sampling rates required are greater than the sample rates that can be sent over a data link, and it is therefore necessary to perform a sample rate conversion. One typical application of sample rate conversion (SRC) may be performed (for example) onboard the UGV, as shown in FIG. 1 . Operator 110 uses controller 120 to control UGV 130 via a wired tether or other means 140 , including wireless communications systems known to one of ordinary skill in the art. Anti-aliasing filter 150 samples joystick 155 data at a sample rate of F in and communicates the position input data to UGV 130 over link 140 . Sample rate F in is up-converted to the UGV's required sample rate F out in converter 160 to control the onboard subsystems.
Sample rate conversions (SRC) of this sort are well known, as (for example) described in Schafer (Ronald W. Schafer and Lawrence R. Rabiner, “A Digital Signal Processing Approach to Interpolation,” Proceedings of the IEEE, vol. 61, no. 6, June 1973, pp. 692-702). Schafer considered the case of two-point linear interpolation and showed that the digital FIR implementation of the SRC has a triangular impulse response. Schafer also considered the general Lagrange interpolator and noted that for odd degree the filter was not linear phase. The Schafer reference, however, did not present a compact and configurable implementation for any of general Lagrange interpolations. Similarly, Ramstad (Tor A. Ramstad, “Digital Methods for Conversion Between Arbitrary Sampling Frequencies,” IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-32, no. 3, June 1984, pp. 577-591 has noted that when the SRC rate is rational, the coefficients required are periodic and can be precomputed. But this paper does not present any method for the generation of the coefficients.
In most cases of sample rate conversion, the group delay of the filter is less important than signal fidelity. However, in remote teleoperation it is desirable to keep the loop delay to a minimum to insure that the vehicle remains controllable, and the SRC filter group delay should also be made as small as possible.
One problem seen in the prior art is that as sensors and payloads change and evolve, different sample rate conversions are required. Not only do the input sample rates change as controllers evolve, but the requirements on F out vary widely as different sensors or other payloads are incorporated on the UGV. Currently, the control software on the UGV is implemented monolithically as dedicated block of code including the SRC computation algorithms. SRC parameters are typically hard coded into the software. This necessitates re-writing and re-compiling the controller code every time the SRC needs to be changed. What is needed is a rapidly reconfigurable sample rate conversion method that allows rapid changes to the SRC parameters without requiring recompiling the control software.
SUMMARY
Presently described is a configurable architecture for a variable parameter sample rate conversion (SRC) system that allows for easy and rapid re-parameterization of the interpolation algorithms without requiring software recompilation. This architecture allows the system operators to reconfigure payload and onboard sensor subsystems of a remote device, such as an unmanned ground vehicle (UGV) or other teleoperated device, without having to re-write and recompile any control software. Changes to the SRC parameters, even to the point of selecting different-order Lagrange interpolations, may be accomplished solely by commanding the use of one of a plurality of pre-defined configuration files stored in the remote device.
Architectures constructed according to the systems, methods, and principles of this disclosure can change the relative sample rate ratio and/or the interpolation algorithms by choosing from among a plurality of pre-defined configuration files. A control program operating on and in a controller reads the parameters particular to the subsystem of interest from the configuration file and uses them to interpolate the output samples. The interpolation is performed according to the selected Lagrange algorithm (or method) on each sample.
In some embodiments, when an onboard sensor or other subsystem is changed or adjusted, the operators need only generate a new configuration file from the desired sample rate parameters (i.e., the input and output sample rates and the interpolation algorithm appropriate to the onboard subsystem and data rates) and upload it to the remote device's onboard controller. Since the algorithms for generating the configuration file are designed to minimize the group delay for the given sample rate ratio, this architecture provides a flexible and reconfigurable solution for the SRC problem without having to recompile the control software on the remote device.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is a block diagram of a prior art sample rate conversion (SRC) system.
FIG. 2 is a block diagram of a prior art fractional rate SRC.
FIG. 3 is an interpolation timing diagram for a sample and hold interpolation algorithm, according to one embodiment of the present invention.
FIG. 4 is plot of a 5 Hz control signal showing input samples at 50 Hz (circles) and output samples at 120 Hz (crosses) for a sample and hold interpolator operating at rate 12/5 SRC, according to one embodiment of the present invention.
FIG. 5 is an interpolation timing diagram for a two-point linear interpolation algorithm for the case when L=12 and M=5, according to one embodiment of the present invention.
FIG. 6 is a plot of a 5 Hz control signal showing input samples at 50 Hz (circles) and output samples at 120 Hz (crosses) for two-point linear interpolation in a rate 12/5 SRC, according to one embodiment of the present invention.
FIG. 7 is an interpolation timing diagram for a quadratic interpolation algorithm for the case when L=12 and M=5, according to one embodiment of the present invention.
FIG. 8 is a plot of a 5 Hz control signal showing input samples at 50 Hz (circles) and output samples at 120 Hz (crosses) for quadratic interpolation in a rate 12/5 SRC, according to one embodiment of the present invention.
FIG. 9 is a flowchart of a high-level SRC process according to one embodiment of the present invention.
FIG. 10 is a flowchart of the interpolation step 940 of the illustrated in FIG. 9 .
FIG. 11 is a block diagram of a UGV system configured to perform SRC according to one embodiment of the present invention.
FIG. 12 is a block diagram of a vehicle platform blade (i.e., the SRC processor) according to one embodiment of the present invention.
DETAILED DESCRIPTION
In this disclosure, we present an efficient and easily configurable method for sample rate conversion (SRC) using Lagrange interpolation algorithms for arbitrary rational sample rate ratios where the group delay is maintained as small as possible. In some representative embodiments, the SRC is accomplished using data stored in one or more of a plurality of candidate configuration files, where different configuration files may be used to provide SRC at different F out /F in ratios and using different interpolation algorithms. (The ratio F out /F in is also referred to herein as the conversion rate.) In other embodiments, a single file with multiple sections (each comprising the filter or interpolation coefficients needed for a particular interpolation algorithm and conversion ratio) may be used.
Such configuration files may contain the interpolation or filter coefficients and the interpolation algorithm to apply for each sample rate conversion ratio needed. Hence, any change in F in or F out can be accommodated by changing the configuration file. Similarly, any change in the anti-imaging performance required by the SRC can also be realized by changing the configuration file. The fractional rate interpolation algorithms considered herein include a sample and hold, two-point linear interpolation (i.e. 1 st order Lagrange), and parabolic (i.e. 2 nd order Lagrange) interpolation, but the method is easily extended to any higher order Lagrange interpolator. Accordingly, although specific interpolators and interpolation algorithms are described, those skilled in the art will realize that interpolators and/or interpolation algorithms other than sample and hold, two-point linear, or higher order Lagrange-type methods can also be used. Accordingly, the concepts, systems, and techniques described herein are not limited to use with any particular type of interpolator.
Embodiments of the present apparatus and method are directed to techniques for SRC that reduce or in some cases even minimize group delay in associated filters while permitting rapid selection of alternate sample rates and/or interpolation algorithms using pre-determined configuration data files stored in a memory. Using an interpolation factor L and a decimation factor M as parameters and an operator-selected Lagrange interpolation appropriate to the application, this architecture provides for embodiments that can generate configuration files containing key lookup parameters for use in the rapid interpolation of output samples.
As noted above, in most SRC implementations, filter group delay is less important than signal fidelity. However, in remote teleoperation in particular, the loop delay between an operator/controller and an unmanned ground vehicle (UGV) should be minimized to insure that the vehicle remains controllable, and in these situations, the SRC filter group delay should be made as small as possible. The factors are determined in part by the types of sensors or payloads being commanded, the input control devices, and the type of interpolation algorithm selected. The sample image rejection needed by the operator also affects these choices, but the proper calculation of the configuration parameters used by the below-described architecture ensures that group delay is kept as small as possible.
To illustrate a typical implementation of sample rate conversion (as, for example but not by way of limitation, in a UGV application), consider a general sample rate conversion (SRC) where the input and output rates are not related by an integer. When the input X N sample rate is 50 Hz and the required output sample rate is 120 Hz, the fractional conversion rate is L/M=12/5. Referring to FIG. 2 , such an SRC may be implemented with system 200 . System 200 consists of up-sampler 210 operating at integer rate L. The up-sampled signal is filtered by filter 220 (for example, a FIR filter). The filtered output is then down-sampled at integer rate M by decimator 230 to produce output signal Y k .
An efficient and configurable SRC implementation is described below for three types of Lagrange interpolations: sample and hold, two-point linear interpolation, and quadratic interpolation. In each case considered below, it is shown that the group delay of the SRC filter is equal to one-half the input sample period.
The sample and hold interpolation algorithm holds and repeats the most recent input sample to obtain the higher output sample rate. Referring to FIG. 3 , for input sample rate F in and output sample rate F out , it is possible to calculate the times at which each input sample must be repeated. FIG. 3 represents the input and output sample timing by slicing time (the horizontal axis) into frames 305 A through 305 E. Circles 310 A, 310 B, . . . , 310 E represent input samples, i.e., the command signals from the controller arriving at rate F in . Circles 320 A, 320 B, . . . , 320 M represent output samples that are sent to the sensor/payload at rate F out . Note that the most recent input sample 310 is used repeatedly, until a new input sample arrives. So, for example, input sample 310 A is sent out ( 320 A) at time zero, time 1/F out ( 320 B), and time 2/F out ( 320 C); input sample 310 B (X 1 ) at time 3/F out ( 320 D) and time 4/F out ( 320 E); and sample 310 C goes at time 5/F out ( 320 F), time 6/F out ( 320 G), and time 7/F out ( 320 H), and so on. At time 5/Fin, the pattern repeats, since this is an example of sample conversion rate of 12/5; output sample 320 M is therefore the first sample of the next five frames.
In each frame, the next input sample (e.g., 310 F, 310 G, . . . 310 J on the far right of each row) has not yet arrived.
The time t in FIG. 3 between the current input sample and the output sample in the n th frame is given by:
t = m - 1 F out - n F i n
as shown in Table 1 for F in =50 Hz and F out =120 Hz, where m is the output frame index and n is the input frame index.
TABLE 1
Lookup table for sample and hold
output times for rate 12/5 SRC.
m
n
t (sec)
1
0
0.000000
2
0
0.008333
3
0
0.016667
4
1
0.005000
5
1
0.013333
6
2
0.001667
7
2
0.010000
8
2
0.018333
9
3
0.006667
10
3
0.015000
11
4
0.003333
12
4
0.011667
The m and n values from this lookup table may then be incorporated in a configuration file used to produce an output sequence of samples at the desired output rate from input samples with the sample and hold method. In one exemplary embodiment, only the n column is included in the configuration file because the m column is functioning as a counter. Thus the configuration file contains at least column n and an identifier of the interpolation algorithm. For sample and hold, the interpolation coefficients are all equal to unity because the sample is being held and not modified.
The software code of Table 2 is an exemplar MATLAB implementation for performing sample and hold interpolation SRC at a rate ratio of 12/5. The values for TOUT are generated based on the output sample rate.
Although a software implementation of this method (and other variations, discussed below) is described in MATLAB, those skilled in the art will realize that other implementations, in other software languages and in hardware, software, or a combination thereof can also be used. Accordingly, the concepts, systems, and techniques described herein are not limited to any particular software language or even to a software-only implementation.
TABLE 2
MATLAB implementation of rate 12/5
SRC for sample and hold interpolation
%-- copyright © 2010 Raytheon Company
tout = 1/Fout;
L = 12;
M = 5;
k = 1;
for n=0:length(yin)−1
if n>0,
nn = mod(n−1,M);
out = [ ];
while (k<=L)&(config(k,1)==nn)
x0 = yin(n);
YOUT = [YOUT x0];
dum = TOUT(end);
TOUT = [TOUT dum+tout];
k = k + 1;
end
if k==L+1, k = 1; end
end
end
The sample and hold interpolation output is shown in FIG. 4 for an exemplar 5 Hz control signal (solid curve). The input sample rate is 50 Hz; the input samples are represented by circles 410 . The output sample rate is 120 Hz; crosses 420 represent the output samples. Although a particular control signal and sampling rates are described, those skilled in the art will realize that various sampling rates and representative control signals other than those illustrated may be used. Accordingly, the concepts, systems, and techniques described herein are not limited to any particular control signal, input, and/or output sample rates. (For clarity in the drawing, not all output samples are visible because all samples within each frame have the same magnitude.)
In the two-point linear interpolation algorithm, one needs to consider an input sample rate F in and an output sample rate F out such that
F out F i n = L M
such that L and M are relatively prime integers. It follows that
L F out = M F i n
and the M th input sample occurs at the same time as the L th output sample. This is shown in FIG. 5 for two-point linear interpolation where the circles 510 A, 510 B, . . . , 510 E represent input samples and circles 520 A, 520 B, 520 C, etc., represent output samples. In general, there will be M frames in two-point linear interpolation and L rows in the interpolation table.
To see how many rows in the interpolation table are generated in each frame, note that we are looking for the indices l such that
m - 1 F i n ≤ l F out < m F i n
in frame m. From this relation it follows that
L ( m - 1 ) M ≤ l < L m M
from which
l = ceil ( L ( m - 1 ) M ) , L , floor ( Lm M )
where ceil(x) is the nearest integer greater than or equal to x and floor(x) is the nearest integer less than or equal to x. The interpolated output sample is given by
y l =aX m +bX m+1
where l is the output sample index and m is the input frame index. To determine the coefficients a and b in the interpolation table for row l in frame m note that, by similar triangles,
y l - X m - 1 X m - X m - 1 = l F out - m - 1 F i n 1 F i n
from which
y
l
=
[
1
-
(
M
l
L
-
(
m
-
1
)
)
]
X
m
-
1
+
[
M
l
L
-
(
m
-
1
)
]
X
m
.
Hence,
b = [ M l L - ( m - 1 ) ]
and a=1−b. Note that the indexing on l starts at 0.
An exemplar MATLAB script to generate a configuration file (also referred to herein as a lookup table) for two-point linear interpolation is shown in Table 3. Examples of the output parameters a and b (the interpolation coefficients) for various SRC rate conversions are shown in Tables 4, 5, and 6. Note that the exemplar code for generating the configuration files in all cases (see, e.g., MATLAB scripts in Tables 3 and 8) is designed to minimize the group delay by interpolating the output samples between the two most recent input samples, resulting in a group delay equal to half of the input sample rate.
TABLE 3
MATLAB script to generate lookup tables for
two-point linear interpolation
%-- copyright © 2010 Raytheon Company
%-- generate config file for rate L/M
%-- there are L rows and M “frames” where a “frame” consists of
%-- all the output samples bracketed by 2 adjacent input samples
L = 8;
M = 3;
for m=1:M %--loop on frame number
upper = floor(L*m/M);
if upper==(L*m/M), upper = upper−1; end
for l=ceil(L*(m−1)/M):upper
b = (M*l/L)−m+1;
a = 1−b;
if l<L, fprintf(1, ′ %d\t%f\t%f\t%d\n′,l+1,m−1,a,b); end
end
end
TABLE 4
Example for rate 12/5 (50 Hz to 120 Hz)
m
n
a
b
1
0
1.000000
0.000000
2
0
0.583333
0.416667
3
0
0.166667
0.833333
4
1
0.750000
0.250000
5
1
0.333333
0.666667
6
2
0.916667
0.083333
7
2
0.500000
0.500000
8
2
0.083333
0.916667
9
3
0.666667
0.333333
10
3
0.250000
0.750000
11
4
0.833333
0.166667
12
4
0.416667
0.583333
TABLE 5
Example for rate 3/1 (40 Hz to 120 Hz)
m
n
a
b
1
0
1.000000
0.000000
2
0
0.666667
0.333333
3
0
0.333333
0.666667
TABLE 6
Example for rate 8/3 (45 Hz to 120 Hz)
m
n
a
b
1
0
1.000000
0.000000
2
0
0.625000
0.375000
3
0
0.250000
0.750000
4
1
0.875000
0.125000
5
1
0.500000
0.500000
6
1
0.125000
0.875000
7
2
0.750000
0.250000
8
2
0.375000
0.625000
An exemplar MATLAB code fragment that generates the output sequence from the input samples is shown in Table 7 where the “config” array consists of the “a,” “b,” and “n” columns in the lookup tables.
TABLE 7
MATLAB implementation of rate L/M SRC
for two-point linear interpolation.
%-- copyright © 2010 Raytheon Company
tout = 1/Fout;
k = 1;
for n=0:length(yin)−1
if n>0,
nn = mod(n−1,M);
out = [ ];
while (k<=L)&(config(k,1)==nn)
a = config(k,2); b = config(k,3);
x0 = yin(n); x1 = yin(n+1);
YOUT = [YOUT a*x0+b*x1];
dum = TOUT (end);
TOUT = [TOUT dum+tout];
k = k + 1;
end
if k==L+1, k = 1; end
end
end
Note that the implementation presented in FIG. 6 for two-point linear interpolation is easily generalized for the sample and hold or parabolic interpolation by adjusting the number of coefficient columns. An example of this table for the sample and hold is given in Table 1. An example input and output of the two-point linear interpolation SRC implementation is shown in FIG. 6 .
In the quadratic interpolation algorithm, the most recent three samples are fit to a quadratic, and the output samples that lie between the most recent two samples are obtained from this fit, as shown in FIG. 7 .
Consequently, the output sample times used for the sample and hold or the two-point linear interpolation cases are unchanged. Making use of the 2 nd order Lagrange interpolator described by Schafer and Rabiner (cited above) and Hamming (R. W. Hamming, Numerical Methods for Scientists and Engineers , New York, McGraw-Hill, 1962, p. 235, (incorporated herein by reference in its entirety), the l th output sample is given by
y l =aX m−1 +bX m +cX m+1
where l is the output sample index, m is the input frame index, and
a
=
d
(
d
-
1
)
/
2
b
=
-
(
d
+
1
)
(
d
-
1
)
c
=
d
(
d
+
1
)
/
2
d
=
(
M
l
L
)
-
m
An exemplar MATLAB script to generate the configuration table for the quadratic interpolation algorithm is shown in Table 8. An example of the output for a rate 12/5 SRC is given in Table 9.
TABLE 8
MATLAB script to generate lookup tables
for quadratic interpolation
%-- copyright © 2010 Raytheon Company
%-- generate quadratic interpolation config file for rate L/M
%-- there are L rows and M “frames”
%-- where a “frame” consists of all the output samples
%-- bracketed by 2 adjacent input samples
L = 12;
M = 5;
for m=1:M %--loop on frame number
mm = m−1;
upper = floor(L*m/M);
if upper==(L*m/M), upper = upper−1; end
for l=ceil(L*(m−1)/M):upper
d = (M*l/L)−mm;
a = d*(d−1)/2;
b = −(d+1)*(d−1);
c = d*(d+1)/2;
if l<L, fprintf(1, ′ %d\t%f\t%f\t%f\t%d\n′,l+1,mm,a,b,c); end
end
end
TABLE 9
Example for rate 12/5 (50 Hz to 120 Hz)
m
n
a
b
c
1
0
−0.000000
1.000000
0.000000
2
0
−0.121528
0.826389
0.295139
3
0
−0.069444
0.305556
0.763889
4
1
−0.093750
0.937500
0.156250
5
1
−0.111111
0.555556
0.555556
6
2
−0.038194
0.993056
0.045139
7
2
−0.125000
0.750000
0.375000
8
2
−0.038194
0.159722
0.878472
9
3
−0.111111
0.888889
0.222222
10
3
−0.093750
0.437500
0.656250
11
4
−0.069444
0.972222
0.097222
12
4
−0.121528
0.659722
0.461806
An exemplar of the MATLAB code that generates the quadratic interpolation from the configuration table is shown in Table 10. Note that the code structures in Tables 10, 7, and 2 are the same. The difference between them is the calculation of the output sample within the “While” loop. Hence, the same code may be used for any of the interpolation algorithms considered where the method to be applied is selected within the “While” loop by a configuration file parameter.
TABLE 10
MATLAB implementation of rate L/M SRC
for quadratic interpolation.
%-- copyright © 2010 Raytheon Company
tout = 1/Fout;
k = 1;
for n=0:length(yin)−1
if n>1,
nn = mod(n−2,M);
while (k<=L)&(config(k,1)==nn)
a = config(k,2); b = config(k,3); c = config(k,4);
xm1 = yin(n−1); x0 = yin(n); xp1 = yin(n+1);
YOUT = [YOUT a*xm1+b*x0+c*xp1];
dum = TOUT(end);
TOUT = [TOUT dum+tout];
k = k + 1;
end
if k==L+1, k = 1; end
end
end
An example input and output of the quadratic interpolation SRC implementation is shown in FIG. 8 .
The process by which configuration files are generated and then employed to change the SRC method as sensors and/or payloads are changed is illustrated in FIG. 9 . In some embodiments, the present system is employed in the remote operation of a device, such as an unmanned ground vehicle (UGV). For each control operation, such as commanding a turn, a control signal is generated in the remote controller. In step 910 , that control signal is sampled, generating an input signal at a first sample rate. The input signal is then transmitted, step 920 , to the UGV.
The input signal is received by the UGV in step 930 . The onboard controller of the UGV then converts the input signal at the first sample rate to the output signal at a second sample rate in step 940 . (This step is further detailed below.) The UGV onboard controller then distributes the output signal to the actuator affected, in this example the steering subsystem, in step 950 . In general, and without limiting the scope of the present disclosure, the sampled output sample is sent to whichever sensor or payload is being commanded remotely.
FIG. 10 illustrates the operation of step 940 in detail. In some embodiments, the conversion process begins by computing one or more configuration files specific to the first and second sample rates in step 1010 . The operator may also select the interpolation algorithm (e.g., but not by way of limitation, sample and hold, two-point linear, quadratic Lagrange, higher order Lagrange, etc.) in step 1015 as an input to step 1010 . The configuration file(s) are then stored in the onboard controller of the UGV in step 1020 .
In other embodiments, steps 1010 , 1015 , and 1020 may be performed before the UGV is operational, or at least before remote commanding begins. In such embodiments, step 940 begins with the reception of the input signal, step 1030 . The onboard controller of the UGV then determines the input signal sample rate (step 1040 ) and uses that information to select the proper configuration file. In step 1050 , the onboard controller uses the coefficients and other parameters stored in the configuration file to interpolate the output samples at the desired output sample rate.
It should be noted that the order in which the steps of the present method are performed is purely illustrative in nature. In fact, the steps can be performed in any order or in parallel, unless otherwise indicated by the present disclosure.
The method of the present invention may be performed in hardware, software, or any combination thereof, as those terms are currently known in the art. In particular, the present method may be carried out by software, firmware, and/or microcode operating on a computer or computers of any type. Additionally, software embodying the present invention may comprise computer instructions in any form (e.g., source code, object code, and/or interpreted code, etc.) stored in any computer-readable medium (e.g., ROM, RAM, magnetic media, punched tape or card, compact disc (CD), and/or digital versatile disc (DVD), etc.). Furthermore, such software may also be in the form of a computer data signal embodied in a carrier wave, such as that found within the well-known Web pages transferred among devices connected to and with computer networks, such as the Internet. Accordingly, the concepts, systems, and techniques described herein are not limited to any particular platform, unless specifically stated otherwise in the present disclosure.
For example, the present architecture may be implemented in a UGV system 1100 exemplified by FIG. 11 . Here, an operator (or remote driver, in the UGV scenario) 1110 controls the remote device (e.g., a UGV) 1120 using a controller blade 1130 having a non-real time operating system (non-RTOS).
The control signals at rate F in are sent from controller 1130 over the RF link 1135 and routed to a non-RTOS platform services blade 1140 . Sample rate conversion (to F out ) is performed in platform services blade 1140 . After conversion, the interpolated samples are routed over vehicle LAN 1145 to vehicle management RTOS blade 1150 . In some embodiments, switches 1146 and 1147 may be employed in LAN 1145 . Vehicle management RTOS blade 1150 then interfaces with and provides control signals to UGV 1120 .
Although both RTOS and non-RTOS blades 1130 , 1140 , and 1150 are described, those skilled in the art will realize that processors and controllers other than blades can be used and that both real time and non-real time operating systems may be employed in each processor. Accordingly, the concepts, systems, and techniques described herein are not limited to any particular type of processor. Indeed, in some embodiments, each blade 1130 , 1140 , and/or 1150 may be a personal computer, a workstation, or other stand-alone computer. In other embodiments, each of blades 1130 , 1140 , and/or 1150 may be implemented in a combination of software and hardware in a distributed computing environment, such as but not limited to a client/server system employing blade servers.
A portion of the internal architecture of platform services blade 1140 , in one exemplary embodiment, is illustrated in FIG. 12 . In the context of the UGV example, this implementation may be embodied within blade 1140 . However, in the general sense, FIG. 12 illustrates the functions of an SRC processor according to some embodiments of the present invention. Here, the input signal arrives from vehicle LAN 1145 on port 1210 for processing by input facility 1220 , which senses rate F in .
The input signal is passed to sample rate conversion (SRC) processor 1230 , which retrieves and reads the appropriate configuration file (or files) from data store 1240 . In some exemplary embodiments, data store 1240 is a memory. Alternatively, data store 1240 may be a storage device, such as but not limited to a hard disk drive, a solid-state drive, a flash drive, or any other type of electronic data storage system known in the art.
Sample rate conversion processor 1230 interpolates the output samples from the input signal and passes the output samples to output facility 1250 . Output facility 1250 , in turn, sends, forwards, or otherwise communicates the output signal (at F out ) to vehicle LAN 1145 .
Input facility 1220 and output facility 1250 may each be implemented as software threads operating within platform services blade 1140 . Alternatively, these facilities may be implemented in hardware within blade 1140 or in a combination of software and hardware, such as but not limited to a digital signal processor and associated microcode or other operational software. Furthermore, the implementation of one facility does not depend on the other. Accordingly, the internal configuration of blade 1140 is not limited to any particular processing architecture, but encompasses all architectures known to those of skill in the relevant arts.
While particular embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes and modifications in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims. Accordingly, the appended claims encompass within their scope all such changes and modifications. Each references cited herein is hereby incorporated herein by reference in its entirety.
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Disclosed is an efficient and configurable apparatus and method for sample rate conversion using interpolation. The apparatus and method employ a configuration file to change the conversion coefficients, sampling rate, and interpolation algorithm without having to recompile control software and/or reprogram the controlled device. In some embodiments, the interpolation employs polynomial interpolation, which may include Lagrange interpolation. In some embodiments, the interpolation method is selected to minimize the loop delay in teleoperation applications.
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CROSS-REFERENCES TO RELATED APPLICATION
This is a continuation-in-part application of our application Ser. No. 532,315 filed Dec. 13, 1974, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to an improved building material, and more particularly to a wall and ceiling covering with the appearance of a sprayed on acoustical pattern for use in mobile homes and the like, and a method for its production.
2. Prior Art
Through the years, manufacturers of mobile homes have tried to develop construction methods and materials which would give the mobile home the appearance of an "on site built home", and which would be able to withstand the physical stresses of moving the home from one site to another. For example, manufacturers have tried to duplicate the interior of a mobile home to look like the interior of any other on site built home especially in the areas of the wall and ceiling. Many have been successful in duplicating the appearance of a house except that the walls and ceiling of the mobile home had grooves or molding where the material used to form the walls or ceiling was joined. This detracts from the ability of the mobile home to give the impression that one is in an on site built home.
Many on site built homes have seamless ceilings and walls which have a pattern on them. One such pattern is sprayed on the ceiling with a pebbled appearance resembling plaster and is referred to in the trade as a "sprayed on acoustical pattern". Many attempts to produce this sprayed on acoustical pattern in mobile homes have been attempted without success. When a sprayed on acoustical ceiling of plaster has been applied in a mobile home, the desired seamless appearance is produced, but as soon as the mobile home was moved, the ceiling cracked which necessitated the replacement of the entire ceiling after each move.
Some manufacturers of modular homes (a home usually moved only once on a flatbed truck) have used a liquid plastic film material containing plastic chips to obtain a flexible seamless wall and ceiling covering. Because this system requires very expensive special preparation of the surface over which it is to be applied and considerable skill for its installation, it is not well suited for the mobile home industry. Another disadvantage is that the ceiling produced is not sufficiently resistant to the stresses which are inherent in moving a mobile home from place to place. Thus, cracks and seams would appear after a move which detracts from the appearance of the walls and ceiling.
Another prior art covering consists of a thin plastic film coated on one side with adhesive. The exposed side of the film has an appearance which approximates a shot acoustical ceiling. The covering is supplied in 12 foot wide continuous rolls and which enables a seamless appearance to be achieved. The film, however, lacks any appreciable "self-leveling" capacity and requires extensive preparation of the wall or ceiling prior to its application. All irregularites in the wall or ceiling, e.g., seams, cracks, etc., have to be puttied, taped, and sanded to provide a smooth surface. Any flaw in the covered surface would "telegraph through" the film. For example, each ceiling panel to be covered is required to be perfectly level with the adjacent panel as the film possess no self-leveling characteristics. A film is self-leveling when the surface of the film bonded to the wall or ceiling is able to deform sufficiently to prevent certain surface irregularities in the wall or ceiling from appearing on the exposed surface. Appearance of the flaw seen as an irregularity in the surface of the film is often described as "telegraph through" the film. Another major disadvantage of this material is that it cannot be repaired in a manner that the repair is undetectable.
As will be seen, the present invention is an improved building material and method which overcomes these prior art deficiencies.
SUMMARY OF THE INVENTION
The building material of the present invention comprises certain elastomeric coatings disposed on a urethane foam substrate. This invention relates to a method for producing the building material and the building material thus produced. More particularly, the method relates to the coating of a urethane foam substrate with an elastomeric material so that a durable, uniform, building material with the continuously textured appearance similar to that of an acoustical shot ceiling is produced. Thus, it is the object of this invention to provide a method for the production of a building material which is seamless, easily repairable, and damage resistant. A further object of this invention is to produce a building material which has the appearance of an acoustical shot ceiling. Yet, a further object of this invention is to provide a building material which may be used as an acoustical ceiling material in mobile homes and which is insulative, has good acoustical properties and is not subject to vibrational damages. Other objects and advantages of the instant invention will be readily apparent from the following descriptions and appendant claims.
Any ceiling or wall material when used in a mobile home, should have the following characteristics and properties: it should be easily repairable and the repairs should be undetectable; it should be resistant to weather damage and have good heat and light stability; it should have good acoustical and insulative properties as well as be aesthetically pleasing; and, finally, it should be flexible (so that it can be moved from place to place without cracking), easily installable and inexpensive.
The subject of this invention results from the unique combination of two types of materials, namely double cell, urethane foam and foamed emulsions of elastomeric resins (such as, acrylic polymers; styrene-butadiene copolymers; nitrile rubber (e.g., acrylonitrile-butadiene-styrene); vinyl chloride-acrylic copolymers; vinylidene chloride-vinyl chloride copolymers; neoprene; and natural rubber) to produce a novel building material with all the aforementioned properties.
The manufacture of urethane foams and elastomeric coating per se are well-known in the art, as are their respective individual properties. Elastomeric materials are typically not self-leveling, nor are they particularly good insulative materials. Urethane foams are self-leveling, have good sound absorption properties, but tend to discolor from sunlight, are non-washable and difficult to color. Certain preferred elastomeric materials on the other hand (preferably acrylic materials) are light resistant and easily colorable. The specific combination of these different types of materials (i.e., double cell urethane foam and elastomeric coating) by the process hereinafter described, produces a novel composite building material with more advantages and features than are attributable to either material alone.
The preferred process for producing the invented building material, having properties and an appearance similar to that of a shot acoustical pattern, comprises; (a) depositing on a cellular urethane foam substrate, a desired thickness of an elastomeric foam coating which is produced by beating an emulsion of the elastomeric resin (with suitable additives) with air until it forms a froth that has the general appearance and spreading properties similar to that obtained in shaving cream dispensed from an aerosol container; (b) controlling the desired thickness and uniformity of the elastomeric coating to allow the formation of a textured surface after crushing; (c) drying the elastomeric coating without causing the elastomeric material to become fully cured or fully cross-linked; (d) crushing the dried elastomeric coated substrate, thereby forcing the elastomeric coating into the cells and pores on the adjacent surface of the urethane foam substrate. The crushing densifies the elastomeric coating into the cells and pores on the adjacent surface of the urethane foam substrate and causes partial compression or distortion of the substrate to produce a composite material which is pliable and which has a textured surface which is similar to that of an on site built shot acoustical ceiling.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objectives and advantages thereof, will be better understood from the following description considered in connection with accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the preferred method by which the composite material of the present invention is made;
FIG. 2 is a perspective view of the composite material of the present invention after it has been crushed to achieve the shot acoustical pattern;
FIG. 3 is an enlarged cross-sectional view of the composite material taken along line 3--3 of FIG. 2 showing the cell structure of the substrate material and the acrylic coating locked therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Broadly, this invention relates to a method for producing a building material which has desirable acoustical properties and has a continuously textured surface, and the products produced therefrom. In FIG. 1 there is shown a schematic diagram which illustrates the method steps performed in the production of the composite material in the presently preferred embodiment.
Referring to FIG. 1, a self-supporting resilient cellular urethane foam substrate 10 is placed on conveyor means 20. The conveyor means is any well-known conventional conveyor system, for example, a continuous wide belt system for moving sheet type materials. The conveyor means is activated by conventional motor means 25 which causes rolls 21 to revolve. The rolls have sufficient friction on the belt to cause the belt to be driven forward. The conveyor means 20 carries the urethane foam substrate 10 under a foamed elastomeric material dispensing means 11 which forms a foamed elastomeric coating 12. In the presently preferred embodiment the dispensing means (e.g. a nozzle or the like) traverses the substrate and applies a stream of a foamed elastomeric emulsion composition thereto. The preferred technique involves dispensing the foamed elastomeric emulsion on the urethane substrate and then controlling the thickness of the foamed elastomeric material as it continues along the conveyor by passing the coated substrate under a skimming means. The skimming means may be a "doctor blade", or metal plate, such that as the substrate and elastomeric foam pass through it, the foam is spread out or removed so as to achieve a desired predetermined thickness which will produce the desired texture after the coated substrate is fully processed. It is possible that the rate of traverse of the dispensing nozzle and the rate of foamed elastomeric material dispensed from the nozzle can be sufficiently controlled so that the desired thickness of coating 12 can be achieved without further skimming. Also, the elastomeric emulsion can be directly sprayed onto the urethane substrate 10 in a uniform desired thickness using a conventional commercial spraying apparatus.
The coated substrate thus formed is shown as composite material 17 in FIG. 1, which is then passed through a dryer means 14 to remove moisture from the composite material and allow partial cross-linking to occur. The presently preferred dryer means is a conventional hot air oven which allows the material on the conveyor to pass through it at a predetermined speed.
The composite material 17 then travels through roller means 15 and is crushed. The presently preferred roller means is a smooth cylindrical roller which can be adjusted to apply the required pressure to the composite material. The composite material is crushed so that the partially cured layer is densified and caused to be interlocked into the adjacent cells on the urethane substrate surface which cells have been distorted by the crushing, the resultant partial compression and distortion of the elastomeric foam creating a continuous texture on the exposed surface thereof. A composite building material 19 with the desired shot acoustical pattern is, thus, formed from the smooth roller means 15. Without further treatment, the material can normally be stored in a relatively dry area for about 10 days to 3 weeks to allow the elastomeric coating to fully cross-link and cure in the pattern obtained after crushing. Optionally, material 19 may be passed through additional heating means 16 to further cure and cross-link the elastomeric coating. The formed material is then rolled and stored in a relatively dry area.
FIG. 2 is a perspective view of the presently preferred embodiment of the invention showing the building material 19. The foamed elastomeric coating 12 has been crushed into some of the adjacent surface cells of the urethane substrate 10. The deformation of the cells in the surface "locks" the acrylic resin to the substrate and produces a textured material that has the desired shot acoustical appearance.
FIG. 3 is an enlarged partial cross-sectional view of the building material 19. One can see that the foamed elastomeric coating 12 has formed a laminate layer or film on the urethane substrate 10, and has been forced into the cellular structure of the urethane. Cell 40 is a typical cell showing the interlocking action of the cell on the elastomeric coating that is achieved by crushing the coated substrate 17 as shown in FIG. 1 with the roller means 15. FIG. 3 illustrates the need for accurate cure and cross-linking control. If the foamed acrylic coating is completely cured prior to crushing, the desired interlocking effect shown by cell 40 will not be achieved. If the coating is insufficiently cured and then crushed, the effect can be a delamination of the elastomeric coating 12 from the substrate 10 when the curing is completed.
The specific polyurethane foam substrate 10, useful in the present invention, may be any self-supporting resilient double cell urethane foam (known in the prior art) which, when the foamed elastomeric coating 12 is crushed into the substrate, the elastomeric coating will form a continuous textured and discrete coating on the adjacent surface of the urethane substrate and will not detach therefrom. The thickness of the elastomeric material should be selected so that after crushing the cellular pattern of the adjacent substrate surface will cause the desired textured appearance on the exposed surface of the elastomeric layer. The texture obtained approximates the random cellular structure of the underlying surface of the substrate material. The term "urethane foam" substrate in the present invention is meant to include various known homopolymers and copolymers crosslinked with organic polyisocyanates forming urethane.
The presently preferred urethane foam substrate has a density of approximately 1-2.6 lbs. per cubic foot and is approximately 1/8 to 3/4 inches thick. The substrate materials which have been found to yield the desired texture are, or resemble what is referred to in the trade as "sea sponge" foams or "double cell" foams and typically contain a major portion of cells which measures up to about 0.75 inches in their greatest dimension. The cells in the urethane substrate are of various sizes and shapes and randomly dispersed. The "larger" cells, i.e. cells greater than about 0.1 inches in the greatest dimension, occupy about 80% or more of the total volume of the substrate. The term "double cell" foam is often also referred to as "buckshot" foam and generally defines the presence of scattered cells in a urethane foam which are about two to four times larger than the typical uniform background cell diameter (see, "A Glossary of Urethane Industry Terms" by S. Alan Stewart and published by the Martin Sweets Company, Inc.). Typical formulations for the manufacture of sea sponge urethane foam having double cell structure, and the properties of such sea sponge foam, are known in the trade and are described, for example, in the "Journal of Cellular Plastics", Volume 11, No. 3, May/June 1975.
If necessary, in some instances the urethane substrate 10 may be cut to expose more of the interior cells enabling better contact between the foam coating and the cells in the substrate to achieve the desired textured pattern.
Various elastomeric materials have been found which achieve the desired result. The presently preferred elastomeric material is an acrylic coating which has the basic formulation set forth below in Example I:
EXAMPLE I______________________________________ACRYLIC LATEX Parts Parts by Weight SolidsComponents Weight % Content*______________________________________A polymeric emulsioncomposition in water basedon ethyl acrylate,acrylonitrile andmethylolacrylamide (for 100 43.02 55.0example, RHOPLEX TR-621,manufactured by Rohm andHaas Company)Sodium salts of acopolymer of maleicanhydride and diisobutylene(for example, TAMOL 731, 1.6 0.7 0.4manufactured by Rohm andHass Company)Titanium dioxide (rutile)for example, TITANOX RA-45from Titanium Pigments 12.5 5.38 12.5Corp. of AmericaAluminum hydrate 55 23.67 55.0Melamine formaldehyde resin(for example, AEROTEX M-3manufactured by American 2.3 0.99 1.8Cyanamid)Emulsion copolymer ofethyl acrylate andmethacrylic acid (forexample ACRYSOL ASE-60 2.9 1.25 0.8manufactured by Rohm andHaas Company)Ammonium hydroxide(28%) 2.0 0.86 --Ammonium stearate 7.0 3.01 2.3Water 49.1 21.12 --______________________________________Total 232.4 100.00 127.8______________________________________ *Water and the ammonia (NH.sub.3) gas given off by the ammonium hydroxide constitute all the non-solid portion of the above formulation of Example I.
In the above-described preferred emulsion formulation, the sodium salts of the copolymer of maleic anhydride and diisobutylene are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; aluminum hydrate is primarily for flame retardance; the melamine formaldehyde resin is a cross-linker for the polymeric composition; the emulsion copolymer of ethyl acrylate and methacrylic acid is a thickener; the ammonium hydroxide is used primarily for pH adjustment (i.e. above 9.5); and the ammonium stearate helps soften and stabilize the foam while acting as a foaming agent.
Other foamed acrylic resins may be used. Suitable acrylic resins for the coating may be formed from resins having about 0.3-1.5% itaconic acid; 40-70% ethyl acrylate; 2-6% butyl acrylate and 0- 7% acylonitrile. However, the preferred composition, recited above, when used on the preferred sea sponge type foam substrate previously discussed, yields a product with excellent over-all properties and a textured finish which has the appearance of a sprayed on acoustical pattern.
In addition to the preferred acrylic elastomeric resins, the following alternate elastomeric resin materials may also be used with satisfactory results: styrene-butadiene copolymer; acrylonitrile-butadiene-styrene terpolymer; vinyl chloride-acrylic copolymer; vinylidne chloride - vinyl chloride copolymer; neoprene (e.g. of copolymer of chloroprene and methacrylic acid or a homopolymer of chloroprene); and, a natural rubber. Examples II - VIII, below set forth certain preferred alternate formulations using various elastomeric resin materials and suitable additives which can be used as a coating in the invented process to obtain the desired textured composite material.
The term "elastomeric" as it is used herein refers to a natural or synthetic high polymer having unique properties of deformation (elongation or yield under strain) and elastic recovery after cross-linking or vulcanization which, when used with the above-described urethane substrate in the presently described process, will provide the desired continuously textured finish and a flexible or yielding composite material that will not crack or peel when rolled for storage or when subjected to moving conditions such as when the material is used as a ceiling or wall material in a mobile or modular home.
The following are the presently preferred alternate elastomeric material formulations:
EXAMPLE II______________________________________Styrene - Butadiene CopolymerLatex (SBR or S Type Elastomer)______________________________________ Parts Parts by Weight SolidsComponents Weight % Content*______________________________________A polymeric emulsioncomposition in waterbased on styrene andbutadiene. The ratioof these would benominally 45% styreneand 55% butadiene. 100.0 50.67 50.00(for example, XD-3004.200latex manufactured by DowChemical Co.)Sodium salts of acopolymer of maleicanhydride anddiisobutylene (for 3.00 1.52 .75example, Tamol 731,manufactured by Rohm& Haas Co.)Titanium dioxide (forExample, Titanox R900from E. I. Dupont) 14.00 7.09 14.00Aluminum trihydrate 33.35 16.90 33.35Melamine formaldehyderesin (for example,Aerotex M-3, manu-factured by AmericanCyanamid) 4.00 2.03 3.20Emulsion copolymer ofethyl acrylate and methacrylicacid (for example, AcrysolASE60 manufactured byRohm & Haas Co.) 1.50 .76 .42Ammonium stearate 10.00 5.07 3.00Water 31.50 15.96 0______________________________________Total 197.35 100.00 104.72______________________________________ *Water constitutes all the non-solid portion of the above formulation of Example II.
In the above-described preferred emulsion formulation, the sodium salt of the copolymer of maleic anhydride and diisobutylene are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; aluminum trihydrate is primarily for flame retardance; the melamine formaldehyde resin is a cross-linker for the polymeric composition; the emulsion copolymer of ethyl acrylate and methacrylic acid is a thickener; and the ammonium stearate helps soften and stabilize the foam while acting as a foaming agent.
EXAMPLE III______________________________________Acrylonitrile - Butadiene - StyreneTerpolymer: (Nitrile Rubber)______________________________________ Parts Parts by Weight SolidsComponents Weight % Content*______________________________________A polymeric emulsioncomposition in waterbased on acrylonitrile,butadiene and styrene.The polymer compositionis nominally styrene 7%,acrylonitrile 30%, 100.00 45.45 50.00butadiene 62% (forexample, Hycar 1572 × 45Latex, manufactured byB.F. Goodrich ChemicalCo.)Sodium salts of acopolymer of maleicanhydride anddiisobutylene (forexample, Tamol 731, 3.00 1.37 .75manufactured by Rohm& Haas Co.)Titanium dioxide (rutile)(for example, TitanoxRA-45 from TitaniumPigments Corp. of America 14.00 6.36 14.00Aluminum Trihydrate 55.00 25.00 55.00Melamine formaldehyderesin (for example,Aerotex M-3 manufactured 6.00 2.73 4.80by American Cyanamid)Emulsion copolymer ofethyl acrylate andmethacrylic acid (forexample, Acrysol ASE-60 3.00 1.36 .84manufactured by Rohm &Haas Co.)Ammonium stearate 6.00 2.73 1.80Water 33.00 15.00 0______________________________________Total 220.00 100.00 127.19______________________________________ *Water constitutes all the non-solid portion of the above formulation of Example III.
In the above-described preferred emulsion formulation, the sodium salts of the copolymer of maleic anhydride and diisobutylene are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; aluminum trihydrate is primarily for flame retardance; the melamine formaldehyde resin is a cross-linker for the polymeric composition; the emulsion copolymer of ethyl acrylate and methacrylic acid is a thickener; and the ammonium stearate helps soften and stabilize the foam while acting as a foaming agent.
EXAMPLE IV______________________________________Vinyl Chloride - Acrylic Copolymer______________________________________ Parts Parts by Weight SolidsComponents Weight % Content*______________________________________A copolymer emulsioncomposition in waterof vinyl chloride andacrylic latex of approx-imately 50% vinyl 100.00 62.50 50.00chloride and 50%acrylic., (for example,Geon 460 × 1 Latex manu-factured by B.F. GoodrichChemical Co.)Sodium salts of copolymerof maleic anhydride anddiisobutylene (for example,Tamol 731 manufactured 3.00 1.88 .75by Rohm & Haas Co.)Titanium dioxide, (rutile)(for example, Titanox 14.00 8.74 14.00R900 from E. I. DuPont Co.)Emulsion copolymer of ethylacrylate and methacrylicacid (for example, 3.00 1.88 .84Acrysol ASE-60 manufac-tured by Rohm & Haas Co.)Ammonium hydroxide 4.00 2.50 --Ammonium Stearate 6.00 3.75 1.80Water 30.00 18.75 0______________________________________Total 160.00 100.00 67.39______________________________________ *Water and the ammonia (NH.sub.3) gas given off by the ammonium hydroxide constitute all the non-solid portion of the above formulation of Example IV.
In the above-described preferred emulsion formulation, the sodium salt of the copolymer of maleic anhydride and diisobutylene are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; the emulsion copolymer of ethyl acrylate and methcrylic acid is a thickener; the ammonium hydroxide is used primarily for pH adjustment (i.e., above 9.5); and the ammonium stearate helps soften and stabilize the foam while acting as a foaming agent.
EXAMPLE V______________________________________Vinylidene Chloride - Vinyl Chloride Copolymer:______________________________________ Parts Parts by Weight SolidComponents Weight % Content*______________________________________A copolymer emulsioncomposition in waterof vinylidene chloride andvinyl chloride latex.The nominal composition is90% vinylidene chloride,10% vinyl chloride.(for example, Geon 100.00 62.50 51.00660 × 1 Latex manufac-tured by B.F. GoodrichChemical Co.)Sodium salts of acopolymer of maleicanhydride anddiisobutylene (forexample, Tamol 731,manufactured by 3.00 1.88 .75Rohm & Haas Co,)Titanium dioxide (rutile)(for example, TitanoxR900 manufactured 14.00 8.75 14.00by E. I. DuPont Co.)Emulsion copolymer of ethylacrylate and methacrylicacid (for exampleAcrysol ASE-60 manu-factured by Rohm &Haas Co.) 3.00 1.88 .84Ammonium stearate 6.00 3.74 1.80Ammonium hydroxide 4.00 2.50 --Water 30.00 18.75 0______________________________________Total 160.00 100.00 68.39______________________________________ *Water and the ammonia (NH.sub.3) gas given off by the ammonium hydroxide constitute all the non-solid portion of the above formulation of Example V.
In the above-described preferred formulation, the sodium salt of the copolymer of maleic anhydride and diisobutylene are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; the emulsion copolymer of ethyl acrylate and methacrylic acid is a thickener; the ammonium hydroxide is used primarily for pH adjustment (i.e., above 9.5); and the ammonium stearate helps soften and stabilize the foam while acting as a foaming agent.
EXAMPLE VI______________________________________Neoprene Latex (Copolymer ofChloroprene and Methacrylic Acid)______________________________________ Parts Parts by Weight SolidsComponent Weight % Content*______________________________________Copolymer emulsion in waterof chloroprene andmethacrylic acid latex. (forexample Neoprene Latex 101manufactured by E. I. 100.00 57.55 46.00by DuPont Co.)Malamine formaldehyde resin(for example Aerotex M-3manufactured by American 5.00 2.88 4.00Cyanamid)Aluminum trihydrate 25.00 14.39 25.00Tricresyl Phosphate 5.00 2.88 5.00Sodium sulfate of higherfatty alcohols (for example,Auqarex WAQ manufacturedby E. I. DuPont Co.) 3.00 1.72 .30Disodium N-octodecylsulfosuccinamate, 35%active, (for example, 2.50 1.44 .88Aerosl 18 manufacturedby American Cyanamid)Sodium salt of polyacrylicacid, 12-13% active, (forexample, acrysol GS 5.00 2.88 .62manufactured by Rohm &Haas Co.)PIGMENT DISPERSIONZinc oxide 2.50 2.50Antimony oxide 2.00 2.00Hindered phenol (orparaphenylenediamine)(for example, WINGSTAY-Lmanufactured by GoodyearTire and Rubber Co.) 1.20 1.20Sodium salts of copolymerof maleic anhydride anddiisobutylene (for example,TAMOL 73 manufactured byRohm & Haas Co.) 2.40 .60Titanium dioxide 5.00 5.00Water 15.15 0______________________________________Pigment DispersionTotal 28.25 16.26 11.30______________________________________Total 173.75 100.00 93.10______________________________________ *Water constitutes all the non-solid portion of the above formulation of Example VI.
In the above-described preferred emulsion formulation, the sodium salts of the copolymer of maleic anhydride and diisobutylene and the sodium sulfate of the higher fatty alcohols are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; aluminum trihydrate is primarily for flame retardance; the melamine formaldehyde resin is a cross linker for the polymeric composition; tricresyl phosphate reduces the flammability and softens the film; the sodium salt of polyacrylic acid is a thickening agent; disodium N-octodecyl sulfosuccinamate is a foaming acid; zinc oxide is an accelerator of cure; antimony oxide also reduces flammability; and hindered alcohol (or paraphenylenediamine) improves the aging properties of the finished product.
EXAMPLE VII______________________________________Neoprene Latex - Homopolymer of Chloroprene______________________________________ Parts Parts by Weight SolidComponents Weight % Content______________________________________Homopolymer emulsion inwater of chloropene (forexample, Neoprene Latex 357manufactured by E. I.DuPont Co.) 100.00 48.77 61.00Aluminum trihydrate 25.00 12.19 25.00Sodium sulfate of higherfatty alcohol (for example,Aquarex WAQ manufacturedby E. I. DuPont Co.) 3.00 1.46 .30Disodium N-octodecylsulfosuccinamate, 35%active, (for example, 3.00 1.46 1.05Aerosol 18 manufacturedby American Cyanamid)Sodium salt of polyacrylicacid, 12-13% active, (forexample, Acrysol GS 6.00 2.93 .75manufactured by Rohm & HaasCo.)Water 30.00 14.63 0PIGMENT DISPERSIONZinc oxide 3.00 3.00Antimony oxide 2.50 2.50Hindered phenol (orparaphenylenediamine)(for example, WINGSTAY-Lmanufactured by GoodyearTire and Rubber Co.) 1.50 1.50Sodium salts of copolymerof maleic anhydride anddiisobutylene (for example,TAMOL 73 manufactured byRohm & Haas Co.) 4.00 1.00Titanium oxide 6.00 6.00Thiocarbanilide or N,N'diphenylthiourea, 33%active (for example,available from MonsantoChemical Co.) 3.69 1.22Water 17.36 0______________________________________Pigment DispersionTotal 38.05 18.56 15.22______________________________________Total 205.05 100.00 103.32______________________________________ *Water constitutes all the non-solid portion of the above formulation of Example VII.
In the above-described preferred emulsion formulation, the sodium salts of the copolymer of maleic anhydride and diisobutylene and the sodium sulfate of higher fatty alcohol are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; aluminum trihydrate is primarily for flame retardance; tricresyl phosphate improves the flammability and softens the polymer; disodium N-octodecyl sulfosuccinamate stabilizes the foam while acting as a foaming agent; the sodium salt of polyacrylic acid is a thickening agent; antimony oxide reduces flammability; the hindered alcohol (or paraphenylenediamine) improves the aging properties of the finished product; and thiocarbanilide is a cross-linking accelerator.
EXAMPLE VIII______________________________________Natural Rubber Latex______________________________________ Parts Parts by Weight SolidComponents Weight % Content*______________________________________Centrifuged Natural RubberLatex, 62% solids 100.00 47.25 62.00Aluminum trihydrate 60.00 33.52 60.00Sodium sulfate of higherfatty alcohol (for example,Aquarex WAQ manufacturedby E. I. DuPont Co.) 5.00 2.36 5.00Disodium N-octodecylsulfosuccinamate, 35%active, (for example, 4.00 1.90 1.40Aerosol 18 manufacturedby American Cyanamid)Methylcellulose 10.00 4.73 .50PIGMENT DISPERSIONZinc oxide .60 .60Antimony oxide 2.50 2.50zinc dibutyl-dithiocarbamatefor example, availableas Butyl Zimate fromR. T. Vanderbilt Co.,Inc.) .10 .10SulfurHindered phenol or 1.10 1.10parapheynylenediamine(for example, Wingstay-Lmanufactured by GoodyearTire and Rubber Co.) 1.50 1.50Sodium salts of copolymerof maleic anhydride anddiisobutylene (for example,TAMOL 73 manufactured byRohm & Haas Co.) 5.00 1.25Titanium Dioxide 6.00 6.00______________________________________Pigment DispersionTotal 32.62 15.41 13.05______________________________________Total 211.62 100.00 141.95______________________________________ *Water constitutes all the non-solid portion of the above formulation of Example VIII.
In the above-described preferred latex formulation, the sodium salts of the copolymer of maleic anhydride and diisobutylene and the sodium sulfate of higher fatty alcohol are dispersants for the pigment; titanium dioxide is a pigment to give opacity and whiteness; aluminum trihydrate is primarily for flame retardance; disodium N-octodecyl sulfosuccinamate is a wetting agent which stabilizes and aid in the foaming; antimony oxide reduces the flammability; zinc dibutyldithiocarbamate and Zinc oxide speed the cure of the system; sulfur is a cross-linking agent; hindered phenol improves the long term aging properties of the product; and methylcellulose is a thickener.
It should be understood that the above-described preferred compositions could contain pigment colors (other than white) and other additives could be added to or substituted to obtain the desired properties. In general the elastomeric compositions used have about 40% to 55% solids content by weight.
The method of making the invented composite material using the above-described elastomeric coatings will now be described in further detail.
The selected elastomeric resin composition is vigorously mixed or beaten until a foam or froth is produced which has the appearance and spreading properties much like that of an aerosol shaving cream. The elastomeric foam may be sprayed, or otherwise deposited on substrate 10 by a conventional foam dispensing means 11. In the preferred embodiment, the dispensing means travels back and forth across the substrate as it lays down the foamed elastomeric resin composition. To form a discrete coating of uniform height, it is usually desirable to skim the foam and spread it to a desired predetermined thickness by skimming means 13. The thickness is such as to permit the irregular cell structure of the underlying sea sponge substrate to affect the exposed surface of the foamed elastomeric layer in the subsequent crushing step so that after the coated substrate 17 is fully processed a continuous texture is formed on the exposed surface of the elastomeric foam layer. It has been found that a foamed elastomeric coating having a thickness of about 1/64 inch to 1/16 inch yields excellent results. In the presently preferred embodiment, a doctor blade 13 is set at the desired height across the conveyor. As the substrate proceeds beneath the blade, the foam 12 is spread out and forms a uniform coating on the substrate. The coated substrate thus formed, shown as component 17 in FIG. 1, comprises the double cell urethane substrate 10 and the foamed elastomeric composition 12 evenly distributed across the top of the urethane. If desired, an evenly distributed elastomeric foam coating can be obtained without skimming by controlled spraying of the coating onto the substrate or by carefully controlling the rate of traverse of the dispensing means and the quantity of foam dispensed. In any event, at the this stage, the elastomeric material on the substrate is still uncured and in its foamy, shaving cream-like state.
The coated substrate is then placed in dryer 14. The presently preferred equipment is a conventional hot air oven dryer utilizing medium velocity heated air of about 220° F. to 300° F. The oven dryer may also be such that separate heating zones within the dryer are maintained within the range of about 220° to 300° F. The speed of the composite 17 through the dryer can vary and the selected speed is dependent on the temperature of the oven and the ambient conditions. It has been determined that in an 80 foot long tunnel oven, a speed of about 4 ft/min at 220° F.; to 5 to 6 ft/min at 260° to 270° F.; and 10 ft/min at 300° F. yield excellent results for the materials described in Examples I to VIII. However, depending on the temperature, length of the oven, ambient conditions, and the speed of the material, it has been found that the composite material can remain in the above-described oven between about 4 to 25 minutes to obtain the desired curing conditions. If the composite passes through the dryer too quickly, the elastomeric material will be too soft and will not have the proper texture for the crushing step. If the composite is over-dried, the elastomeric material may become over cured. This latter condition will prevent proper embedding of the foamed acrylic in the urethane substrate during the crushing step. The time duration of the component in the oven and the oven temperature is, therefore, controlled such that only the desired degree of curing or cross-linking of the acrylic resin takes place. The oven temperature and speed of the coated material is also controlled to prevent the elastomeric foam from having excess moisture when it leaves the drying oven. The elastomeric material should retain sufficient malleability and tact, after drying, to enable the elastomeric foam to be embedded into the irregular double cell structure of the urethane foam substrate after it passes through the rollers 15. It has been found that the elastomeric coating must also hold the urethane substrate in a partial compression or distortion, at the same time permitting a certain amount of post crush substrate recovery in order to produce the overall desired continuous texture and appearance.
After the coated product is dried in drying means 14, it is cooled to about 60° F. to 110° F. prior to crushing. The cooled product is then set between a pair of crushing means 15 which densify the foamed elastomeric coating into the adjacent cells in the surface of the urethane substrate, which cells have been previously filled with the elastomeric froth. The presently preferred roller pressure is at least about 75 to 80 pli (pounds per linear inch). The units "pli" are commonly used in the industry to define the force per linear dimension exerted on the material to be crushed or calendared between two rollers along the line defining the points of greatest compression of the material. Under the above-described conditions, there is sufficient force to distort the cells of the urethane substrate, and to densify the predetermined thickness of elastomeric material thereby producing the desired textured effect. Using the above-described sea sponge substrate, there is usually enough cell wall thickness to hold the cell in a permanent distortion after crushing. It is the present understanding of the inventors that the malleable elastomeric material is physically interlocked into the urethane foam cells on the surface of the urethane substrate as the cells are deformed by the crushing means 15. The interlocking results in the cells holding the elastomeric material in partial compression and distortion which gives the exposed surface of the elastomeric material the desired texture. When the partially cured elastomeric layer is crushed, it also deforms the cells of the underlying urethane and becomes interlocked therein to prevent delamination of the elastomeric layer from the substrate. Other bonding between the substrate 10 and the elastomeric material 12 may also take place (e.g. dipole, Van de Waals, etc.) to some extent.
After crushing, the final composite building material 19 is produced except for the post-crushing cure or final cross-linking of the elastomeric material which can be accelerated somewhat, if desired, by placing the material 19 in an optional heating means, such as an oven 16. The finished material is then rolled into bales. If an oven 16 is not used for the final cure, the composite material 19 should be kept in a dry place for about 10 days to 2 weeks before usage to allow the elastomeric coating to adequately cure and permanently hold the continuous textured pattern formed in conjunction with the substrate 10.
Application of the building material 19 to a surface such as the inside of a mobile or modular home, is easily achieved. The wall or ceiling is cleaned and freed of any dirt or oil; an adhesive is applied thereto, followed by application of the building material 19. The elastomeric coating 12, thus, becomes the exposed or exterior surface, while the urethane substrate 10 is bonded directly to the wall or ceiling. The prior art problem of slight irregularities telegraphing through the covering is prevented as the urethane foam substrate is sufficiently flexible and resilient to cover the irregularities without any noticable effect seen in the exposed textured elastomeric coating 12. The underlying urethane substrate 10 acts as a compressible insulation material while the elastomeric coating provides the user with the desired exterior shot acoustical pattern effect.
The building material thus produced, will not crack, chip or peel. It can be painted if desired, with conventional latex paints and washed. The material is also odorless, non-deteriorating, and resists fungus, mildew and insects. Minor rips, cuts or tears, or the like, can be patched or repaired by applying small amounts of their elastomeric material to the areas to be patched and then allowing such patched areas to cure. Because of the continuous textured surface such minor tears rips and cuts are not normally detectable and, therefore, the material can be easily repaired without detracting from the over-all desired appearance.
It should be understood that the final cure or cross-linking of the elastomeric coating should not take place until after the crushing step has taken place since it has been found there will be some tendency for the fully cured elastomeric material to leave the exterior of the cells of the urethane foam after crushing, thus, destroying the desired shot acoustical pattern and texture described above. Also, the finished composite material should not be exposed to excessive moisture prior to the final cure or cross-linking step since there is also a tendency for such moisture to cause the uncured or partially cured acrylic coating to leave the contour of the cells of the urethane foam substrate.
It should also be understood that while the application described in the preferred embodiment deals with a suitable material for mobile and modular homes and the like, the invented method and products have other applications as a building, construction or decorative material and the applications described herein are merely exemplary.
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A textured building material, suited for use as an acoustical wall and ceiling covering, comprising a cellular urethane foam substrate and an elastomeric coating and a method for its production is disclosed. The building material is flexible and damage resistant, which makes it especially useful in mobile vehicles and homes. The process consists of applying a foamed elastomeric resin emulsion onto a urethane substrate to a desired thickness; drying the coated substrate thus formed; and thereafter crushing the dried elastomeric coated substrate to form a composite textured material.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending International Application No. PCT/GB2004/001949 filed May 6, 2004 which designates the United States, and claims priority to Great Britain application no. 0310916.2 filed May 13, 2003 and Great Britain application no. 0327976.7 filed Dec. 2, 2003.
FIELD OF THE INVENTION
[0002] The present invention relates to flooring, and in particular to flooring of the pre-stressed deck construction.
BACKGROUND
[0003] Many buildings, particularly industrial and high-rise buildings are constructed by erecting a steel girder framework with the above-ground floors consisting of steel decking supported by the beams of the girder framework and the decking itself supporting a concrete floor. The floor spans are limited by the bending stresses in the decking due to the weight of the concrete floor, and the deflection of the decking and concrete floor. In order to increase the floor span, it is known to prop the decking at mid-span until the concrete floor has set and reached adequate strength. However, this strength achieving time can be of the order of four weeks, and meanwhile the presence of the props restricts further construction activity. In addition, the props are costly and there is the additional time and cost of fitting and removal. Alternatively, the decking may be supported by means of additional “secondary beams” secured to the beams of the girder framework, but again these are an additional expense. Furthermore, the presence of the secondary beams restricts the passage of services, e.g. gas, water and electricity pipes and cables, through the floor space. As a further alternative, the flooring may be formed of pre-stressed concrete, but this is very costly to produce and transport to the site. In addition, large capacity lifting gear is required to position the flooring.
[0004] To avoid or minimise these disadvantages for large floor spans, it is known, for example in U.S. Pat. No. 3,712,010, to introduce an upward camber, and hence a positive bending moment, in the decking prior to pouring the concrete floor thereon. This arrangement is intended to counteract the downward deflection and negative bending moment in the decking due to the weight of the concrete floor, to allow a larger floor span to be used without the stress and deflection limits being exceeded. U.S. Pat. No. 3,712,010 discloses two methods of achieving this initial upward camber and positive bending moment. In the first method, embodied as shown in FIGS. 1 to 8 and 13 to 17 , there is a tension rod or tendon extending between the ends of the decking. This tension rod is located in an upwardly facing channel of the decking, which is shaped to be symmetrical about a central horizontal plane, the neutral axis of the decking. The tension rod is secured to brackets attached to the ends, or upwardly bent ends, of the decking, so that it is only at the centre of the span that the tension rod is significantly below the neutral axis of the decking. In consequence, the positive bending moment induced in the decking when the tension rod is tightened will be very small, and the stress in the rod has to be substantial to achieve the desired effect, thereby requiring high-grade steel. Furthermore, since the load induced on the ends of the decking through the brackets or bent ends is wholly or largely on the bottom surface of the decking, there will be a negative bending stress induced at the ends of the decking. This further reduces the positive bending stress induced at the centre of the decking span. There is the additional time consuming and costly operation of welding the tension rod to the centre of the decking in the embodiment of FIGS. 5 to 8 and 13 to 17 . In the embodiment shown in FIGS. 9 to 12 the tension rod is located in the downwardly facing channel of the decking. Even in this case the tension rod is attached to the decking above the neutral axis (see FIG. 12 in particular), in order to maximise the inclination of the tension rod, generating some negative bending stresses at the ends of the decking as in the above described embodiments. Furthermore, this embodiment introduces the complexity of the centrally disposed post to form the upward camber in the decking, and effectively requires independently applying tension to both ends of the tension rod. The assembly of the post to the decking is a time consuming and costly operation, and exposes the construction to the risk of fire. In addition, this construction may interfere with the passage of services through the floor space. WO 88/01330 discloses a floor channel and tension rod disposed beneath the neutral axis of the channel. However, the neutral axis of the channel is below the central plane, and this low neutral axis, will cause undesirable higher bending stress in the upper horizontal part and lower stresses in the bottom part of the section.
[0005] It is an object of the present invention to provide flooring of pre-stressed deck construction that overcomes, at least to a substantial extent, the disadvantages of the known constructions.
SUMMARY
[0006] The invention provides flooring of pre-stressed deck construction comprising an elongate decking having an upwardly facing channel formation extending therealong, having a tension rod extending between the ends of the decking and located in the channel below the neutral axis of the decking along the length of the decking, wherein the formation is asymmetrically profiled whereby the neutral axis is above a central horizontal plane.
[0007] Preferably, the flooring comprises a stressing bracket secured to each end of the decking, the tension rod being connected to each stressing bracket. Each stressing bracket may be secured to the decking above the tension rod. The stressing brackets may be secured to upwardly extending sidewalls of the channel. The tension rod may extend through a loading bush located in each stressing bracket. Each stressing bracket may be formed of sheet material bent to provide a load face and upper, lower and two opposed side flanges, each flange extending substantially perpendicular to the load face. The loading bush may be located in an aperture in the load face.
[0008] Connection means may connect the tension rod to the decking at a mid location therealong.
[0009] The connection means may be a support clip, which may be of a resilient material. The support clip may be of spring steel. Heat insulation material may be disposed between the tension rod and the decking. The insulation material may be polypropylene, or preferably porous mineral fibre.
[0010] The decking may have upper flanges extending laterally of the channel, and the flanges may have interlocking formations extending along their longitudinal edges, whereby a decking may be mutually engaged in side-by-side disposition with an adjacent decking. The decking may have a male formation extending along the edge of one upper flange and a female formation extending along the edge of the other upper flange and adapted to receive a male formation of another decking.
[0011] The flooring may comprise a supporting girder framework with the decking being attached to the girder framework. In this case, the stressing bracket may be attached to the girder framework. The girder framework may comprise an I-beam having upper and lower flanges, in which case the stressing bracket may be secured to the upper flange of the I-beam, and may be secured to the underside of the upper flange. The stressing bracket may be secured to the flange of the I-beam by means of screwed studs. The screwed studs may bear on the flange through a countersunk collar. The studs may extend upwardly of the upper flange of the I-beam and into a concrete floor supported by the decking.
[0012] The flooring may comprise lateral rods extending transversely of the decking. The lateral rods may be supported above the decking by spacer blocks. The lateral rods may be connected to the decking and may be connected to the interlocking formations of the decking. The lateral rods may be connected to the interlocking formations by means of connecting clips. The connecting clips may be of a resilient material, and may be of spring steel.
[0013] The concrete floor may have at least one cavity therein. The cavity may be lined with a waterproof material, which may be a plastics material. The cavity lining may contain water, which may be heated or cooled. The cavity lining may have a plug in an aperture therein, the plug being of a material adapted to melt in the event of a fire in the proximity of the flooring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention will now be described with reference to the accompanying drawings in which:
[0015] FIG. 1 is a perspective view of a length of decking,
[0016] FIGS. 2 and 3 show respectively the development and folded stressing bracket,
[0017] FIG. 4 is a longitudinal section through the end of a decking attached to the girder framework,
[0018] FIG. 5 is a lateral centre-span section through two adjacent deckings,
[0019] FIG. 6 is an end view of two adjacent deckings,
[0020] FIG. 7 shows a support clip of FIG. 5 to an enlarged scale,
[0021] FIG. 8 shows a connecting clip of FIG. 5 to an enlarged scale,
[0022] FIG. 9 shows stacked units during transportation, and
[0023] FIGS. 10 and 11 are side and plan views respectively of an alternative support clip.
DETAILED DESCRIPTION
[0024] Referring now to FIG. 1 , there is shown a length of decking 10 . The decking 10 has, in use, an upwardly facing channel 11 formed by a base 12 and sidewalls 13 . Ribs 14 are formed in the base 12 and sidewalls 13 for stiffening purposes. In addition, the decking 10 is formed with upper flanges 15 that are also provided with stiffening ribs 14 . The channel 11 tapers downwardly, and the upper flanges 15 are considerably larger than the base 12 . In consequence of this profile of the decking 10 , the neutral axis is as high as is practicably possible above the centre line of the section, as shown. This maximises the dimension between the neutral axis and the applied tension. One upper flange 15 is formed with a female interlocking formation 16 along its free edge, which is adapted to receive a male interlocking formation 17 formed along the free edge of the other upper flange 15 . By this means adjacent deckings 10 may be attached to each other as shown in FIGS. 5 and 6 . This construction provides a vertical shear interlock and lateral thrust load transfer between adjacent deckings 10 that assists inter-decking load sharing in either direction;
[0025] At each end of decking 10 there is provided a stressing bracket 20 as shown in developed and folded configurations in FIGS. 2 and 3 . The stressing bracket 20 is formed of sheet material, preferably steel, bent to provide a load face 21 and upper, lower and two opposed side flanges 22 , 23 , and 24 respectively. When the stressing bracket 20 is bent into shape, each flange 22 , 23 , 24 extends substantially perpendicular to the load face 21 . In addition, side flanges 24 are further bent to form top flanges 25 . An aperture 26 is provided in the load face 21 , holes 27 are provided in side flanges 24 , and holes 28 are provided in top flanges 25 for purposes to be described below. A torsion plate 29 may be provided, for example at mid-span, as a precautionary strengthening of the decking 10 . This would abate possible twist distortion during transportation.
[0026] Referring now to FIG. 4 there is shown a stressing bracket 20 secured to the end of a decking 10 . The side flanges 24 of the stressing bracket 20 are secured by means of bolts or rivets through the holes 27 to the sidewalls 13 of the decking 10 . With these bolts or rivets being in a near-vertical sidewall 13 of the decking 10 , shear loads from the decking 10 are transferred effectively to the stressing bracket 20 . As a more economical alternative for factory prepared units, the stressing bracket 20 may be resistance spot welded. The stressing bracket 20 effectively bears onto a stiffened compression zone at the end of the decking 10 beneath the neutral axis. Pure axial compression stress can be developed in this zone. The end of span shear forces associated with the weight of the decking 10 are taken through the near vertical sidewalls 13 of the decking 10 , and transferred via the bolts, rivets or welding to the bracket 20 . This arrangement minimises combined stress effects in the compression zone and the shear sidewalls 13 . A tension rod 40 passes through a loading bush 41 located in the aperture 26 in the load face 21 stressing bracket 20 . Nut 42 on the end of tension rod 40 is tightened to tension the rod 40 and apply a bending stress to the decking 10 . Since the tension rod 40 is below the neutral axis of the decking 10 , the bending stress applied to the decking 10 is positive, causing upward arching of the decking 10 . Also, since the attachment of the stressing bracket 20 to the decking 10 is above the tension rod 40 , there is no negative bending stress applied to the ends of the decking 10 . In fact, the positive bending stress applied is enhanced by this configuration.
[0027] The stressing bracket 20 is secured to the top flange 43 of an I-beam 44 forming part of the girder framework of the building. For this purpose, shear studs 45 pass through countersunk holes in the top flange 43 and through the holes 28 in top flanges 25 of the stressing bracket 20 . A nut 46 on the bottom of the shear stud 45 secures the stressing bracket 20 and the I-beam 44 together. In known constructions, the shear studs are welded to the flange of the girder framework, but this is a time consuming and expensive operation. With the present arrangement, the shear studs 45 bear on the flange 25 through a countersunk collar 47 , and assembly of the decking 10 to the girder framework 44 is simplified and less costly than was the case previously. Furthermore, this attachment of the stressing brackets 20 to the I-beams 44 using the shear studs 45 creates a rigid structure providing lateral restraint to the girder 44 to prevent lateral deflection under load.
[0028] Referring now to FIGS. 5 to 8 , there is shown adjacent deckings 10 attached to each other by means of the male interlocking formation 17 of one decking 10 being received in a female interlocking formation 16 of the adjacent decking 10 . At the centre of the span, each tension rod 40 is connected to the decking 10 by means of a spring steel support clip 50 . This provides additional central support for the decking 10 to counteract the bending stresses induced in and mid-span deflection of the decking 10 caused by the weight of the concrete floor 53 . However, unlike the previously known welding attachment, such attachment does not facilitate the transfer of heat through the floor 53 and tension rod 40 to the decking 10 . In addition, heat insulation material 51 , for example polypropylene or porous mineral fibre quilting, is disposed between the tension rod 40 and the decking 10 for the purpose of resisting the spread of fire. For the purpose of preventing, or at least minimising the risk of, shrinkage cracks in the concrete floor 53 , lateral rods 52 are located above the decking 10 . The lateral rods 52 are connected to the decking 10 at suitable intervals by means of spring steel connecting clips 54 . The connecting clips 54 clip to the interlocking formations 16 , 17 of the decking 10 . By this means, relative longitudinal movement between adjacent deckings 10 is resisted, thereby resisting vertical shear in the concrete floor 53 and providing longitudinal restraint to the girder 44 . A services aperture 48 is shown in the girder 44 . Lightweight spacer blocks 57 of a plastics material, e.g. dense polystyrene, are provided (only one is shown in FIG. 5 ) to act as a support for the lateral rods 52 . This enables the lateral rods 52 to be located at the optimum height for concrete shrinkage crack control in the floor 53 . In addition, the spacer blocks 57 ensure that the lateral rods 42 are not in damaging contact with the decking 10 . Use of the spacer blocks 57 as a packing/spacer during transportation of the deckings 10 is shown in FIG. 9 .
[0029] After such assembly, and after tensioning the tension rods 40 to the required upward deflection and stress in the deckings 10 , the concrete floor 53 is poured onto the deckings 10 . As the decking 10 is loaded by the concrete flooring 53 , the pre-camber introduced into the decking 10 by tensioning of the rod 40 will straighten out, followed by sagging to the permissible centre deflection. This creates an end rotation of the decking 10 that will increase the tension in the tension rod 40 and hence reduction of the negative bending stress on the decking 10 caused by the weight of the concrete flooring 53 , Le. the arrangement is partially self-stress relieving. As shown in FIG. 6 , from which the I-beam 44 has been removed for clarity, the concrete floor 53 envelops the longitudinally grooved shear studs 45 to resist shear in the floor 53 across the I-beam 44 . The countersunk collars 47 reduce the risk of slip between the shear studs 45 and the flange 43 . The floor 53 also envelops the lateral rods 52 , again to resist shear in the floor 53 . To reduce the weight of the floor 53 , and therefore the negative bending stresses induced in the decking 10 by the weight of the concrete floor 53 , voids 55 are created in the floor 53 . The spacer blocks 57 also locate the lateral rods 52 to allow the maximum size of the voids 55 , and in themselves form light voids to reduce the weight of the floor 53 . The voids 55 are lined with a non-degradable material, for example of a plastics material, and filled with water or other fire preventing fluid, e.g. an inert gas such as carbon dioxide. The lining of voids 53 is suspended from the lateral rods 52 . A tube 56 extends from the lined void 55 to the insulation blanket 51 . A plug (not shown) of a material that will readily melt in the event of a fire, is disposed in the tube 56 to allow the water or other fluid to escape in the event of a fire. The water or other fluid may be heated or cooled to provide underfloor heating/cooling if desired.
[0030] Instead of the connecting clips 54 , an alternative form of connecting clip 58 is shown in FIGS. 10 and 11 . This clip 58 is preferably of resilient steel wire, and has the advantages that it does not project into the concrete floor 53 , it supports the lateral rods 52 at a complimentary level to the spacer blocks 57 and could be of differing sizes to vary the depth of support to the lateral rods 52 for differing ponding depths of concrete floor 53 .
[0031] By means of the invention, a flooring of pre-stressed deck construction is provided that allows for larger spans than was possible heretofore without exceeding stress and deflection limits. For a given dimensional arrangement, because of lower bending stress levels and centre-span deflection, lower grades of steel for the decking and tension rods can be used, thereby resulting in a cheaper construction. The present construction also provides enhanced lateral stiffness and resistance to shear and lateral deflection, resulting in a more efficient supporting girder through the restraint to the compression flange and reduced tendency to cracking of the concrete floor. In addition, the present construction provides greater resistance to heat transfer through the floor and increased safety in fire situations.
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A flooring of pre-stressed deck construction having an elongate decking extending along the flooring is provided. The decking has an upwardly facing asymmetrically profiled channel formation whereby the neutral axis is above a central horizontal plane. A tension rod extends between stressing brackets secured to each end of the decking and is located below the neutral axis of the decking along the length of the decking. Each stressing bracket is secured to upwardly extending sidewalls of the channel above the tension rod. The decking is attached to the girder framework of a building.
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TECHNICAL FIELD
The present invention relates to the field of floating wind turbines and, in particular, to a method and apparatus for moving an offshore floating wind turbine.
BACKGROUND OF THE INVENTION
As used herein, the term “floating wind turbine” means a wind turbine structure of the kind that is designed to float in a body of water when in use. Conventional floating wind turbines comprise a buoyant body having at its upper end a nacelle, which contains an electrical generator and other components, and a rotor. The body is generally long and approximately cylindrical in shape.
Offshore floating wind turbines are very large structures, the body being typically 100-200 meters in length and the rotor blades in the range of 40-70 meters long. They are assembled on shore or in protected waters and it is a significant challenge to move them to their desired location out at sea.
One approach is to tow them out to their installation sites through the water, whilst floating in the same, generally vertical, position in which they are used. This prevents the generator from being submerged under water or splashed, which could damage its components.
With this method, the choice of an installation site for the wind turbine and the possible routes thereto are therefore limited by the depth of the water through which the wind turbine must pass. If the water in a region is too shallow, the floating wind turbine cannot be towed through that region making some installation sites unreachable, or only reachable via an indirect, longer route.
As an alternative, methods of transporting wind turbines in an essentially horizontal position are known. However, these methods require a large vessel on which the wind turbine is supported in order to keep the delicate rotor and generator components away from the water. For example, GB 2423108 discloses mounting structures, such as offshore wind turbines, using socket foundations. The mounting structure is transported to the socket in an essentially horizontal (reclined) position, on board another vessel. In another example, GB 2344843 discloses a gravity securing system for offshore generating equipment. The generating equipment is towed to the installation site in an essentially horizontal (reclined) position, again on board another vessel. It will be appreciated that the use of such vessels increases the cost of transporting the wind turbine and their size may also restrict the choice of route or installation location.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of moving a floating wind turbine relative to a body of water, the floating wind turbine having a buoyant body with a nacelle at the upper end thereof, the method comprising floating the floating wind turbine in the body of water and towing the floating wind turbine whilst holding the buoyant body in an inclined position whereby the nacelle is held clear of the water.
Thus, the inventors have recognised that it is possible to float a wind turbine while it is transported in such a way that its draught can be significantly reduced whilst keeping the delicate components within the nacelle clear of the water. It can then be placed into the conventional vertical configuration prior to use. In this way it can pass through shallower water than if it were towed in a vertical position, and the number of possible installation sites is thereby increased. At the same time, the need for a vessel large enough to carry an entire wind turbine is avoided.
The angle of inclination to the surface of the water should be significant in order to provide a useful reduction in draught. The precise angle of inclination (from the surface) can vary depending on the circumstances and may be in the range of 20 to 60°. Usually 30 to 50° will be appropriate in order to achieve a useful reduction in draught whilst keeping the turbine clear of water. These angles represent the average angle. It will be apparent that there will be some degree of oscillation about the average due to the effect of waves and wind.
The body of the wind turbine forms its support structure. The support structure typically comprises a lower support structure, which, when installed, is generally mostly submerged, and a tower, which, when installed, is generally above the water line.
In the present invention, in order to position a floating wind turbine in an inclined position, a floating member may be attached to the lower support structure. The floating member enables the wind turbine system to be positioned and held in an inclined position by exerting an upward force on the lower support structure. The floating member could be any suitable buoyant structure, for example a buoyancy tank. When the wind turbine reaches the installation site, the floating member may be removed and the wind turbine can assume an essentially vertical position, suitable for operation. The floating member is therefore preferably detachable, although it could remain in place and be ballasted, e.g. by flooding it with water
It is preferred that whilst the floating wind turbine is inclined, the force from the floating member may be adjusted so as to keep the wind turbine in static equilibrium. The force may be adjusted by the floating member, for example with water.
Additionally or alternatively to the floating member, a weight may be attached to the tower to further enable the positioning and holding of the wind turbine system in a desired inclined position by exerting a downward force on the tower. If a weight is attached, preferably it should be attached to the tower just above the water line in order to minimise the bending moments exerted on the support structure, which, if excessive, could lead to structural damage. However, it is most preferred that no such weight should be added, in order to avoid the wind turbine system becoming too submerged, which would risk damage to the wind turbine generator. If a weight is added, for the reasons discussed above in relation to the floating member, it is preferred that the weight should be detachable.
The floating member may be attached to the support structure by a line, for example a wire, chain or cable. In order to move the wind turbine from a vertical position to an inclined position, the length of the line may be reduced, for example by winching it into the floating member or the support structure.
In addition, a pair of almost horizontal forces (i.e. a couple) may be applied to the system in order to overcome the righting moment of the wind turbine whilst it is positioned at intermediate inclination angles. Such almost horizontal forces may be applied, for example, by a tug or (when close to the shore) by a winch with a wire fixed on land. In this discussion, an “almost horizontal force” means a force with an horizontal component that is significantly greater than its vertical component.
As noted previously, a wind turbine generator typically comprises a nacelle and a rotor The combined centre of gravity of these components is generally offset from the longitudinal axis of the support structure. As the centres of gravity and buoyancy of the support structure are located close to the longitudinal axis of the support structure, the inclined wind turbine may be in an unstable equilibrium and may tend to rotate about the longitudinal axis of the support structure. This can be a problem as it is important to keep the wind turbine generator out of the water to avoid damaging it.
In order to address this problem, a “crow foot” or “bridle” arrangement of lines may be used to attach the line from the floating member to the support structure. This may be formed of two lines, for example lengths of wire or cable, that connect either side of the support structure to the line from the floating member to form a Y-shaped arrangement of lines. This will help to ensure rotational stability of the system about the longitudinal axis of the support structure.
During tow-out of the wind turbine system, waves may excite the system and cause it to oscillate. It is desirable to minimise or eliminate any excitation of the system to prevent water damage to the generator.
The most energetic waves generally have a period of around 5 to 20 seconds. Therefore, in order to reduce or eliminate excitation of the system due to heave (almost purely vertical displacement of the system), the natural periods of oscillation of the inclined system should preferably be outside of the range of approximately 5 to 20 seconds, i.e. not equal to the period of the most energetic waves. Preferably, the natural periods of the system should be greater than 20 seconds. However, in some cases, such as where the stiffness of the system is too great for this to be a practical choice, some of the natural periods of the system could be less than 5 seconds.
In order to achieve such natural periods of the system and minimize the dynamic interaction between heave and pitch motions, the distance from the centre of gravity to the waterline around the support structure should ideally be approximately equal to the distance from the centre of gravity to the point of attachment of the buoyancy tank.
In order to reduce or eliminate excitation of the system due to pitch (rotation of the system about its centre of gravity), the centre of buoyancy of the system should ideally be close to its centre of gravity.
Thus, it will be seen that the invention in its broadest sense relates to the provision of a floating wind turbine in an inclined position whereby it can be towed through water with a lesser draught than if it were in the vertical configuration in which it is used, whilst the nacelle remains clear of the water.
The invention also extends to a floating wind turbine in such a configuration and to one that is adapted to be held in such a configuration by the provision of one or more float(s) and optionally one or more weight(s). Furthermore, the invention extends to a method of installing an offshore floating wind turbine comprising constructing the offshore floating wind turbine, transporting it to its installation site according to the method previously described, placing the floating wind turbine into its vertical configuration and installing it. The last step generally comprises tethering or mooring the structure to the seabed.
These and other features and improvements of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described by way of example only and with reference to the following drawings in which:
FIG. 1 illustrates the forces acting on a preferred embodiment of a floating wind turbine in an inclined position;
FIG. 2 illustrates the forces acting on a preferred embodiment of a floating wind turbine with a floating member attached thereto;
FIG. 3 illustrates the forces acting on a preferred embodiment of a floating wind turbine with a floating member attached thereto and almost horizontal forces being applied to the system;
FIG. 4 shows the location of the centre of gravity of the system in a lengthwise vertical cross section of the tower;
FIG. 5 is another vertical cross section through a tower, with a crows foot device attached thereto, in a plane orthogonal to that shown in FIG. 4 .
DETAILED DESCRIPTION
FIG. 1 shows the forces acting on a preferred embodiment of a floating wind turbine (hereafter “wind turbine”) 1 in an inclined position. The wind turbine 1 comprises a support structure 2 and a wind turbine generator 3 . The support structure 2 comprises a lower support structure 4 and a tower 5 . The wind turbine generator 3 comprises a nacelle 10 and a rotor 11 . F G is the weight of the wind turbine 1 . F B is the buoyancy force of the wind turbine 1 .
In order to keep the wind turbine 1 in an inclined position, an upwardly directed force F 1 is required. As illustrated in FIG. 1 , F 1 should act from a position on the lower support structure 4 that is below the centre of gravity of the wind turbine 1 . Optionally, a downwardly directed force F 2 acting above the centre of buoyancy may also be applied to the wind turbine 1 .
The inclined floating position of the wind turbine 1 should be stable. This requires a stable equilibrium of forces and moments in the vertical plane through the longitudinal axis of the support structure 2 . Considering the forces indicated in FIG. 1 , this means that:
F B +F 1 −F G −F 2 =0 (1)
and
F 1 x 1 −F G x G +F B x B −F 2 x 2 =0 (2)
where F B , F 1 , F G and F 2 are defined above and in FIG. 1 , and x 1 , x G , x B and x 2 are the horizontal coordinates of where the forces F 1 , F G , F B and F 2 , respectively, act on the wind turbine 1 .
The forces F 1 and F 2 could be applied to the wind turbine 1 by, for example, a buoyancy tank 6 attached to the lower support structure 4 , as shown in FIG. 2 , and a clump weight (not shown) attached to the tower 5 close to the water line 12 , respectively. If the clump weight were attached higher up the tower 5 , it would contribute more effectively with respect to inclining the wind turbine but it could introduce large bending moments in the tower 5 , which could bend or damage the structure of the tower 5 .
A further problem associated with applying an external force F 2 to the wind turbine 1 , is that it can result in an undesirable greater submergence of the wind turbine 1 (unless further modifications to its buoyancy are made). It is therefore preferred that in most cases F 2 should be set equal to zero and no clump weight or similar should be attached.
Ideally, the wind turbine 1 should (for this part of the operation) be designed such that its centre of gravity G should be as close to the centre of buoyancy B as practically possible (see FIG. 2 ). By positioning G and B as close together as possible, this reduces the required magnitude of F 1 . The required magnitude of F 1 can also be reduced by making F 1 act on the wind turbine 1 as far down the lower support structure 4 as possible, as shown in FIG. 1 .
As shown in FIG. 2 , the buoyancy tank 6 may contain ballast 7 , such as water. By altering the amount of ballast 7 in the buoyancy tank 6 , the magnitude of force F 1 may be adjusted. The buoyancy tank 6 may include any type of conventional access for adding or removing water therefrom via a pump and the like. This may also be achieved by adjusting the length L 1 of a line 8 shown in FIG. 2 .
The buoyancy tank 6 is a floating member that is connected to the lower support structure 2 via the line 8 . The length of the line 8 may be shortened or lengthened via a winch 17 attached to either the buoyancy tank 6 or the lower support structure 4 . By winching the line 8 in or out, the depth L 1 of the end of the lower support structure 2 beneath the water line 12 can be varied.
The wind turbine 1 can be placed in an inclined position by adjusting the length of the line 8 to vary the depth L 1 until the wind turbine 1 has the desired inclination angle α, as shown in FIG. 2 .
In order to move the wind turbine 1 from an initial vertical position to an inclined position for towing, the line 8 is initially relatively long. The depth L 1 is then reduced by winching in the line 8 . Simultaneously, as shown in FIG. 3 , a pair of almost horizontal forces F H1 and F H2 are applied to the wind turbine 1 in order to overcome the righting moment of the wind turbine 1 in the intermediate inclination angles, while it is being moved from a substantially vertical position, to a stable inclined position.
The pair of almost horizontal forces F H1 and F H2 can be applied by using a tug or a winch together with a wire fixed on land, for example. The required magnitude of these forces F H1 and F H2 may be determined by considering the static equilibrium of the wind turbine 1 in all inclination angles from 90 degrees to the actual inclined position. FIG. 3 shows the pair of almost horizontal forces F H1 and F H2 applied by a line 18 and a line 19 . The lines 18 , 19 may be in communication with a winch 20 fixed on land or elsewhere.
The actual inclination angle α is chosen with consideration given to the depth of the water through which the wind turbine 1 is to be towed, the length of the wind turbine 1 below the water line 12 and the height of the nacelle 10 and rotor 11 of the wind turbine generator 3 above the water line 12 . Ideally, the wind turbine 1 should be in an inclined position such that there is simultaneously sufficient clearance above the water line 12 for the nacelle 10 and rotor 11 so that they do not get wet and a sufficient reduction in draft.
The inclined wind turbine 1 should ideally also be stable with respect to rotation about its longitudinal axis.
FIGS. 2 and 3 show towing the wind turbine 1 whilst holding the support structure 2 as a buoyant body 21 in an inclined position by repositioned line 19 . If the wind turbine 1 is towed in the inclined position as illustrated in FIG. 1 , the combined centre of gravity of the nacelle 10 and rotor 11 in most cases will be located above the longitudinal axis 13 of the support structure 2 . The centre of gravity of the support structure 2 is usually located close to the longitudinal axis 13 . The centre of buoyancy of the support structure 2 is also usually located close to the longitudinal axis 13 . However, as the combined centre of gravity of the nacelle 10 and rotor 11 is usually located above the longitudinal axis 13 , the centre of gravity G of the whole wind turbine 1 is thus also located slightly above the longitudinal axis 13 , as shown in FIG. 4 . Therefore, any slight movement of the wind turbine 1 about the longitudinal axis 13 will thus tend to cause rotation of the wind turbine 2 about the longitudinal axis 13 . Due to this unstable equilibrium, the wind turbine 1 would tend to end up in a floating position with the rotor 11 located beneath the longitudinal axis 13 and therefore closer to the water line 12 , where it may be more likely to be splashed by waves, or possibly even submerged.
In order to avoid this happening, the buoyancy tank 6 can be used to introduce a sufficient righting moment to compensate for the moment introduced by the asymmetry of the weight distribution of the wind turbine 1 about the longitudinal axis 13 .
As illustrated in FIG. 4 , the centre of buoyancy B of the wind turbine 1 is located approximately on the longitudinal axis 13 and the centre of gravity G of the wind turbine 1 is located a distance y G from the axis 13 . When the support structure 2 is inclined at an angle α to the horizontal, there is a moment M G from the weight of the wind turbine 1 about the axis 13 , which can be written as follows:
M G =−θmgy G cos α (3)
where m is the mass of the wind turbine 1 , g is the acceleration due to gravity and θ is the angle of rotation about the axis 13 . θ is assumed to be small in the stability considerations. The negative sign indicates that the moment M G is destabilising.
The moment M G may be compensated for by a moment from the buoyancy force F 1 (and possibly the weight F 2 , if present). The buoyancy tank 6 can be connected to the support structure by a single line 8 at a distance y F from the axis 13 . The righting moment M F1 from the buoyancy force F 1 can then be written as follows:
M F 1 =θF 1 y F cos α. (4)
In order for the system to be stable with respect to rotation about the axis 13 , this therefore requires that:
M F 1 +M G >0 (5)
and
F 1 y F >mgy G . (6)
In most cases mg>>F 1 . Therefore, according to requirement (6), it should be required that y F >>y G in order to ensure stability. If y F is not sufficiently large, it may be increased by using a crow foot 9 at the end of the line 8 between the buoyancy tank 6 and the support structure 2 , as shown in FIG. 5 .
When a crow foot 9 is used, the moment M F1 about the axis 13 from the buoyancy force F 1 can be written as follows:
M F 1 =θF 1 r cos α (7)
where r is the vertical distance from the axis 13 of the support structure 2 to the top point 14 of the crow foot 9 . As r>y F , the rotational stability of the system about the axis 13 is increased by using the crow foot 9 .
Equation (7) is valid when θ cos α<tan β (assuming small rotation angles θ), where β is half of the angle between the two lines 15 of the crow foot 9 , as indicated in FIG. 5 . If the rotation angle θ exceeds tan β/cos α, then one of the lines 15 of the crow foot 9 will become slack and the effect of the crow foot 9 will disappear. However, as the rotation angle θ is generally small, the crow foot 9 can be an effective means for achieving the required stability in relation to, rotation about the axis 13 of the support structure 2 .
Stability may also be obtained or improved by adjusting the position of internal ballast contained within the support structure 2 . In this way, y G <0 (i.e. the centre of gravity being located beneath the longitudinal axis 13 of the support structure 2 ) may be obtained.
As well as the static stability of the system, it is also important to consider its dynamic stability. Waves can be the most important sources of dynamic excitation during tow-out of a wind turbine 1 . The dynamic response of the wind turbine 1 should ideally be limited as much as possible in order to avoid possible wetting of the nacelle 10 and rotor 11 and in order to limit the possible dynamic load on the tower 5 and lower support structure 4 .
A full assessment of the dynamic loads on the system caused by waves requires a coupled dynamic analysis, where the effect of the wind turbine 1 itself, the buoyancy tank 6 and possible clump weight, as well as all wire arrangements including the towing wire are included in the analysis. The wave forces, hydrodynamic mass and damping should also be considered.
However, in general, it is important for the natural periods of the system to be outside of the range of periods of the most energetic waves, i.e. outside of the range of approximately 5 to 20 seconds.
An initial estimate of the system's natural periods can be obtained by considering an uncoupled system. The parameters of the buoyancy tank 6 and its location can then be adjusted so that requirements for both static and dynamic equilibrium are fulfilled.
Heave motion is an almost entirely vertical displacement of the system. The inertia M 33 involved in such an oscillation can be written as follows:
M 33 =m+A 33 ≅m+ρV cos 2 α (8)
where M 33 is the effective mass for vertical heave oscillations, m is the total dry mass of the system (including the buoyancy tank 6 and possible clump weight), A 33 is the hydrodynamic mass in heave of the support structure 2 and ρV is the mass of the displaced water. For simplicity, it is assumed that the displacement and added mass of the buoyancy tank and possible clump weight are much less than the corresponding values for the wind turbine 1 .
The restoring force coefficient C 33 in the heave direction can be determined from the water plane area of the inclined support structure 2 and the buoyancy tank 6 as follows:
C 33 = ρ g ( π R 2 cos α + A 1 ) ( 9 )
where R is the radius of the support structure 2 (which, for simplicity, is assumed here to have a circular cross section) and A 1 is the water plane area of the buoyancy tank 6 .
The natural period T 3 of the system for a pure, un-damped heave motion can then be written as follows:
T
3
≅
2
π
M
33
C
33
.
(
10
)
In order to avoid the range of periods of the most energetic waves (i.e. from about 5 to 20 seconds), T 3 should ideally be greater than about 20 seconds.
In order to avoid too strong coupling between heave and pitch, the two terms in equation (9) for C 33 should be approximately equal. Moreover, the distance from centre of gravity G to the water line 12 of the support structure 2 should be approximately equal to the distance from centre of gravity G to the point of attachment of the buoyancy tank 6 to the support structure 2 . In other words, as shown in FIG. 3 , the centre of gravity G should be about halfway between the point of attachment of the buoyancy tank 6 to the support structure 2 and the point where the support structure 2 passes through the water line 12 .
It is also important to consider pitch. M 55 is the contribution to the inertia of the system due to pitch rotation around the centre of gravity G of the wind turbine 1 and it can be written as follows:
M 55 = I 55 + A 55 ≅ I 55 + 1 12 ρπ R 2 L 3 + ρπ R 2 L ( ξ G - ξ B ) 2 ( 11 )
where I 55 is the moment of inertia of the wind turbine 1 about the centre of gravity G and A 55 is the hydrodynamic inertia of the submerged part of the support structure 2 . The approximate expression given in the second part of equation (11) is obtained by assuming the support structure 2 is a long, slender cylinder with a constant radius. The coordinate ξ is measured along the axis 13 of the support structure 2 such that x=ξ cos α. L is the length of the submerged part of the support structure 2 .
In a similar way, the pitch restoring coefficient C 55 can be written as follows:
C 55 = ρ gA 1 ( x G - x F 1 ) 2 + ρ g π R 2 cos α ( x G - x WL ) 2 ( 12 )
where x WL is the x-coordinate of the centre of the water plane area of the support structure 2 .
The natural period of the system in pitch T 5 can then be written as follows:
T
5
≅
2
π
M
55
C
55
.
(
13
)
If the system is not approximately symmetric about the centre of gravity G of the wind turbine 1 , the coupled heave-pitch equations of the system should be solved. This would involve coupled inertia and restoring terms of the form M 35 and C 35 .
As with the case for heave, and for the same reasons, ideally T 5 >20 seconds. However, in certain cases, for example where the stiffness of the system is particularly large, T 5 <5 seconds would be a more practical choice.
From equation (12), it can be seen that the symmetry of the system would be improved if:
A 1 ≅ π R 2 cos α . ( 14 )
Furthermore, the moment of inertia I 55 in equation (11) should have a minimum value close to centre of gravity G. This requirement is generally fulfilled for the contribution related to the dry mass of the system. It will also be approximately fulfilled for the hydrodynamic mass of the system if the centre of buoyancy B is close to the centre of gravity G.
A further type of motion that should be considered is roll. Roll about the axis 13 of the support structure 2 is generally only weakly coupled to the other modes of motion (heave and pitch). The inertia in roll generally has only an insignificant contribution from hydrodynamic effects. This means that roll inertia M 44 can be written as follows:
M 44 =I 44 +A 44 ≅I 44 (15)
The restoring effects against roll come from the possible clump weight and the buoyancy tank 6 , as discussed above. For small roll angles it can be assumed that the buoyancy force F 1 remains approximately constant. (The same is also true for F 2 ).
Considering only the buoyancy tank 6 , and not a possible clump weight, the roll restoring force C 44 can be written as follows:
C 44 =−mgy G +F 1 r cos α (16)
and the natural period in roll T 4 can then be written as follows:
T
4
≅
2
π
M
44
C
44
.
(
17
)
It should be apparent that the foregoing relates only to the preferred embodiments of the present application and that numerous changes and modification may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.
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A method of moving a floating wind turbine relative to a body of water, the floating wind turbine having a buoyant body with a nacelle at the upper end thereof, including the steps of floating the floating wind turbine in the body of water, and towing the floating wind turbine while holding the buoyant body in an inclined position, whereby the nacelle is held clear of the water. As the wind turbine is held in an inclined position, it can be towed through regions of shallower water than if it were in a vertical position.
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INCORPORATION BY REFERENCE
The present application claims priority from Japanese patent application Ser. No. 2008-240157 filed on Sep. 19, 2008, the content of which is hereby incorporated by reference into this application.
TECHNICAL FIELD
The present invention relates to a low alloy steel for generator rotor shafts, which has excellent magnetic properties.
BACKGROUND ART
There have been known materials for rotor shafts, on which a magnetic field winding is mounted, such steels as shown in JP-B-47-25248 and JP-B-50-7530. In particular, as a generator shaft material necessitating not lower than 700 MPa of tensile strength at room temperature, a steel containing not less than 3.0% nickel and not more than 2.0% chromium as disclosed in ASTM Standard A469 has generally been used.
BRIEF SUMMARY OF THE INVENTION
Conventionally, as a rotor shaft material for a comparatively large size generator driven by a gas turbine or a steam turbine, a low alloy steel containing not less than 3.0% nickel has been used. However, such low alloy steel for generator rotor shafts containing the above range of nickel is inferior in magnetic properties. As a result, the efficiency of the generator decreases. On the other hand, since nickel is an essential component for improving the low alloy steel in hardenability although deteriorating magnetic properties, it has been difficult to reduce the nickel amount.
Accordingly, an object of the present invention is to provide a low alloy steel for generator rotor shafts, which low alloy steel contains a lower amount of nickel than those in conventional low alloy steels, and has improved magnetic properties and realizable hardenability.
Another object of the present invention is to provide a low alloy steel for generator rotor shafts, which low alloy steel has not lower than 700 MPa of tensile strength at room temperature, not higher than 275 AT/m of magnetizing force at room temperature, and not higher than 7° C. of FAIT.
Under the above objects, there is provided a low alloy steel for generator rotor shafts, which low alloy steel contains a reduced amount of nickel, an increased amount of chromium, and additive copper.
Specifically the low alloy steel contains, by mass percent, a primary component of Fe, 1.3 to 2.0% Ni, 2.1 to 3.0% Cr, and 0.15 to 0.35% Cu.
More specifically the low alloy steel consists essentially of, by mass percent, 0.15 to 0.35% carbon, 0.01 to 0.10% Si, 0.10 to 0.50% Mn, 1.3 to 2.0% Ni, 2.1 to 3.0% Cr, 0.20 to 0.50% Mo, 0.15 to 0.35% Cu, 0.06 to 0.14% V, and the balance of Fe and unavoidable impurities.
Using a low alloy steel according to the invention for generator rotor shafts, it is possible to reduce a field current being allowed to pass in a coil of a generator rotor since the low alloy steel is excellent in magnetic properties, so that the loss of the generator decreases thereby enabling the generation efficiency to be improved.
DETAILED DESCRIPTION OF THE INVENTION
If the nickel amount of the low alloy steels for generator rotor shafts is reduced, their hardenability will be deteriorated. Thus, a low alloy steel containing not less than 3.0% nickel has been used. The present inventors made researches on the hardenability of low alloy steels, and found that in the case where the nickel amount of those is reduced to a specific range, they can have a quench effect equivalent to that of a low alloy steel containing not less than 3.0% nickel by adding proper amounts of chromium and copper. Further, the inventors found that by manufacturing a generator with use of a generator rotor shaft material of a thus obtained alloy in which the nickel amount is made lower than that of conventional materials, the magnetic properties of the generator are improved as compared with conventional generators thereby improving the generation efficiency.
Hereinbelow, there will be provided a description of functions of the additive elements in the alloy of rotor shafts and reasons why the composition ranges of the elements are preferred.
Carbon is an indispensable element in order to improve hardenability and strength of the generator rotor shaft material, so that the low alloy steel needs it in an amount of not less than 0.15%. However, if the carbon amount exceeds 0.35%, toughness of the generator rotor shaft material is deteriorated. Therefore, the carbon amount is set to be 0.15 to 0.35%, preferably 0.20 to 0.30%.
Silicon has a deoxidizing effect, so that it has been added to generator rotor shaft materials as an element for improving the cleanliness of thereof. In recent years, by virtue of the progress of steel manufacturing technique such as the carbon deoxidation method under vacuum, a sound generator rotor shaft material can be produced by melting without additive silicon. From the viewpoint of prevention of temper embrittlement, the silicon amount should be a lower level, that is, within the range of 0.01 to 0.10%.
Manganese is an indispensable element in order to improve hardenability and toughness of the generator rotor shaft material, so that the material needs it in an amount of not less than 0.10%. However, if the manganese amount exceeds 0.50%, there will occur temper embrittlement of the generator rotor shaft material. Therefore, the manganese amount is set to be 0.10 to 0.50%, preferably 0.20 to 0.45%.
Nickel is an indispensable element in order to improve the generator rotor shaft material in hardenability, toughness of a central section of the material, and magnetic properties, so that the material needs it in an amount of not less than 1.3%. However, if the nickel amount exceeds 2.0%, the magnetic properties of the generator rotor shaft material are deteriorated. Therefore, the nickel amount is set to be 1.3 to 2.0%, preferably 1.4 to 1.8%.
Chromium is an indispensable element in order to improve hardenability and strength, and toughness of the central section of the generator rotor shaft material, so that the material needs not less than 2.1% of chromium. However, if the nickel amount exceeds 3.0%, the generator rotor shaft material is deteriorated in strength. Therefore, the chromium amount is set to be 2.1 to 3.0%, preferably 2.3 to 2.8%.
Molybdenum is an indispensable element in order to improve the generator rotor shaft material in hardenability, and toughness of the central portion of the material, and to alleviate temper embrittlement, so that the material needs not less than 0.20% of molybdenum. However, if the molybdenum amount exceeds 0.50%, the generator rotor shaft material is deteriorated in magnetic properties. Therefore, the molybdenum amount is set to be 0.20 to 0.50%, preferably 0.30 to 0.40%.
Copper is an indispensable element in order to improve hardenability, and toughness of the central section of the generator rotor shaft material, so that the material needs not less than 0.15% of copper. However, if the copper amount exceeds 0.35%, the generator rotor shaft material is deteriorated in forgeability. Therefore, the copper amount is set to be 0.15 to 0.35%, preferably 0.20 to 0.30%.
Vanadium heightens yield stress of the generator rotor shaft material by forming carbide particles to cause fine crystal grains, so that the material needs not less than 0.06% of vanadium. However, if the vanadium amount exceeds 0.14%, the generator rotor shaft material is deteriorated in toughness. Therefore, the vanadium amount is set to be 0.06 to 0.14%, preferably 0.08 to 0.12%.
The unavoidable impurities may be Al, P, S, Sn, Sb, As, and so on. The Al amount should be a lower level because aluminum deteriorates the material in toughness. The Al amount is preferably not more than 0.012%. The sulfur amount should be a lower level because sulfur forms inclusion MnS to deteriorate the material in toughness. The sulfur amount is preferably not more than 0.015%. The amounts of P, Sn, Sb, As and so on should be lower because these elements are liable to generate temper embrittlement of the material. Preferably, the P amount is not more than 0.020%, the Sn amount is not more than 0.015%, the Sb amount is not more than 0.004%, and the As amount is not more than 0.015%.
The invention low alloy steel material for generator rotor shafts may be produced by the following process:
(1) A melt of the material prepared by means of an electric furnace, and thereafter the melt is refined by a vacuum degassing process, a carbon deoxidation process under vacuum or an electroslag remelting process;
(2) the thus produced melt is cast into a die to produce an ingot;
(3) the ingot is subjected to hot forging at a temperature of not lower than 1150° C., subsequent normalizing at a temperature of not lower than 840° C., and subsequent tempering at a temperature of not lower than 600° C. to make fine crystal grains; and
(4) subsequently the thus obtained material is subjected to austenitizing at a temperature of 860 to 900° C., subsequent quenching, such as water cooling, water jet cooling or water spray cooling, and subsequent tempering at a temperature of 560 to 660° C. to adjust mechanical properties of the material.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a graph showing the relationship between the nickel amount and the magnetizing force;
FIG. 2 is a graph showing the relationship between the chromium amount and the tensile strength;
FIG. 3 shows a generator rotor shaft as one embodiment of the present invention; and
FIG. 4 is a general view of a generator which includes a generator rotor shaft with use of the invention material.
Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
Embodiments
Hereinbelow, there will be provided a description of embodiments of the invention low alloy steel material for generator rotor shafts. Table 1 shows the chemical compositions (mass %) of specimen steels. Specimen steel Nos. 3 to 7 and 9 to 14 are of embodiments of the present invention. Specimen steel Nos. 1, 2 and 8 are of comparative materials produced through melting for the purpose of comparison. Specimen No. 1 corresponds to Class 7 of ASTM Standard A469 concerning generator rotor shaft materials.
TABLE 1
Specimen
Steel No.
Fe
C
Si
Mn
Ni
Cr
Mo
V
Cu
Al
P
S
Sn
Sb
As
Comparative
1
Balance
0.22
0.05
0.29
3.47
1.67
0.39
0.10
0.02
0.002
0.005
0.001
0.0025
0.0009
0.0030
material
Comparative
2
Balance
0.27
0.04
0.26
1.16
3.12
0.36
0.09
0.20
0.005
0.007
0.004
material
Invention
3
Balance
0.28
0.07
0.27
1.30
2.64
0.37
0.10
0.21
0.004
0.011
0.003
material
Invention
4
Balance
0.30
0.03
0.26
1.43
2.62
0.38
0.11
0.25
0.005
0.014
0.004
material
Invention
5
Balance
0.26
0.03
0.29
1.67
2.56
0.35
0.10
0.27
0.006
0.013
0.007
0.0060
0.0012
0.0061
material
Invention
6
Balance
0.24
0.04
0.28
1.79
2.52
0.34
0.12
0.26
0.003
0.021
0.006
material
Invention
7
Balance
0.26
0.01
0.27
1.98
2.50
0.36
0.11
0.28
0.004
0.009
0.005
material
Comparative
8
Balance
0.21
0.02
0.22
2.26
2.01
0.35
0.10
0.30
0.005
0.007
0.003
material
Invention
9
Balance
0.22
0.05
0.36
1.65
2.11
0.31
0.12
0.27
0.007
0.008
0.006
material
Invention
10
Balance
0.20
0.04
0.45
1.68
2.21
0.34
0.12
0.25
0.009
0.007
0.004
material
Invention
11
Balance
0.24
0.09
0.32
1.60
2.41
0.30
0.11
0.23
0.006
0.006
0.005
0.0036
0.0013
0.0083
material
Invention
12
Balance
0.21
0.07
0.28
1.62
2.69
0.34
0.08
0.24
0.005
0.008
0.003
material
Invention
13
Balance
0.26
0.10
0.20
1.64
2.79
0.40
0.09
0.27
0.007
0.006
0.006
material
Invention
14
Balance
0.26
0.06
0.24
1.67
2.97
0.36
0.09
0.26
0.003
0.009
0.004
material
Each of the specimen steels was prepared by the following process:
(1) A 20 kg ingot was produced by casting a melt of steel prepared by a melting furnace.
(2) The ingot was subjected to hot forging at a temperature of 1150 to 1250° C. to make a product having a thickness of 30 mm and a width of 90 mm.
(3) The product was subjected to a heat treatment simulating a cooling rate of a central section of a rotor shaft body in a large size generator, which heat treatment included normalizing at a temperature of 900° C., heating the work up to 880° C. for austenitizing, quenching the work from the temperature of 880° C. at a cooling rate of 200° C./hour, tempering at a temperature of 600 to 640° C. for 33 hours, and cooling to room temperature at a cooing rate of 30° C./hour in this order, wherein the tempering treatment was conducted by selecting a temperature such that obtained tensile strength of the work was within a range of not lower than 700 MPa for each specimen steel.
Each of the specimen steels subjected to the above heat treatment was subjected to a tensile test, a 2 mm V-notch Charpy impact test, and a DC magnetic property test. The tensile test was conducted at room temperature with use of a reduced size (5 mm diameter) No. 4 test piece of JIS Z 2201. The 2 mm V-notch Charpy impact test was conducted in a temperature range of −80 to +40° C. with use of a V-notch test piece of JIS Z 2202. The DC magnetic property test was conducted at room temperature with use of a test piece having a diameter of 200 mm and a length of 45 mm by the method specified in JIS C 2501 (a closed magnetic circuit is formed by an electromagnet and a test piece). The test results are shown in Table 2. FATT denotes a transition temperature through which there arises a transformation between a ductile fracture surface and a brittle fracture surface obtained by the impact test. The lower the value of FATT temperature, the higher the toughness of steel. In the DC magnetic property test, a magnetizing force was determined when a magnetic flux density reaches 21.2 kG (kilogauss). As the value of magnetizing force increases, the steel is excellent in magnetic property.
TABLE 2
Specimen
Tensile strength
0.02% proof stress
Reduction of
Magnetizing
Steel No.
(MPa)
(MPa)
Elongation (%)
area (%)
FATT (° C.)
force (AT/cm)
Comparative
1
879
716
21
64
−20
351
material
Comparative
2
745
588
23
61
10
297
material
Invention
3
748
590
22
63
4
267
material
Invention
4
750
592
24
62
−1
251
material
Invention
5
753
595
23
65
−5
248
material
Invention
6
755
596
23
63
−8
254
material
Invention
7
757
598
22
62
−12
267
material
Comparative
8
761
600
23
64
−15
286
material
Invention
9
701
554
22
61
12
247
material
Invention
10
726
574
21
63
7
245
material
Invention
11
751
593
22
60
−3
249
material
Invention
12
746
589
23
64
−17
247
material
Invention
13
735
581
21
63
−22
246
material
Invention
14
704
556
22
62
−32
248
material
As will be appreciated from Table 2, the invention specimens, having preferable alloy compositions, have not lower than 700 MPa of tensile strength, not higher than 275 AT/m of a magnetizing force, and not higher than 7° C. of the FATT. Since generator rotor shafts rotate at 3000 to 3600 rpm, and repeats start and stop everyday, especially a slot section must be designed so as to withstand tensile stress incurred by a rotation centrifugal force. If the tensile stress exceeds the 0.02% proof stress in the slot section of a generator rotor shaft, there will arise problems such that plastic deformation is liable to occur, and fatigue fracture is liable to occur due to repeating stress fluctuation. Also, in the case where the values of elongation and reduction of area are low, the fracture toughness is low, and the fatigue fracture is liable to occur.
FIG. 1 shows an influence of nickel amount on the magnetizing force when the magnetic flux density reaches 21.2 kG. As shown in FIG. 1 , the magnetizing force is low when the nickel amount is in the range of 1.3 to 2.0%. Therefore, the nickel amount should be in the range of 1.3 to 2.0%. FIG. 2 shows an influence of chromium amount on tensile strength at room temperature. As shown in FIG. 2 , not lower than 700 MPa of tensile strength at room temperature is attained when the chromium amount is in the range of 2.1 to 3.0%. Therefore, the chromium amount should be in the range of 2.1 to 3.0%. As shown in Table 2, the invention specimen steels have not higher than 7° C. of FATT, so that the toughness of the central section is also excellent.
FIG. 3 is a perspective view showing one example of a generator rotor shaft. The rotor shaft shown in FIG. 3 has a magnetic pole 1 , a coupling 2 , fan mounting rings 3 , centering rings 4 , slots 5 , and teeth 6 . The invention material is most suitably applied to the magnetic pole 1 , the coupling 2 , and the teeth 6 , for example.
FIG. 4 is a general view of a generator. The whole of the generator shown in FIG. 4 has a generator rotor shaft 7 , a rotor coil 8 , a retaining ring 9 , a collector ring brush 10 , a fan 11 , a bearing 12 , a stator coil 13 , an iron core 14 , a stator frame 15 , and a high-voltage bushing 16 .
It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.
The invention low alloy steel for generator rotor shafts is used as a generator rotor shaft material which is driven by a gas turbine or a steam turbine. In particular, it is used as a rotor shaft material having a tensile strength not lower than 700 MPa at room temperature.
DESCRIPTION OF REFERENCE NUMERALS
1 . . . a magnetic pole
2 . . . a coupling
3 . . . fan mounting rings
4 . . . centering rings
5 . . . slots
6 . . . tooth
7 . . . a generator rotor shaft
8 . . . a rotor coil
9 . . . a retaining ring
10 . . . a collector ring brush
11 . . . a fan
12 . . . a bearing
13 . . . a stator coil
14 . . . an iron core
15 . . . a stator frame
16 . . . a high-voltage bushing
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Disclosed is a low alloy steel material for generator rotor shafts, which has tensile strength of not less than 700 MPa at room temperature. Preferably the low alloy steel material consists of, by mass percent, 0.15 to 0.35% carbon, 0.01 to 0.10% Si, 0.10 to 0.50% Mn, 1.3 to 2.0% Ni, 2.1 to 3.0% Cr, 0.20 to 0.50% Mo, 0.15 to 0.35% Cu, 0.06 to 0.14% V, and the balance of Fe and unavoidable impurities.
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FIELD
This invention relates to the field of irons.
BACKGROUND
Clothing irons, also known as flatirons or merely irons, are devices used to press clothing to remove wrinkles and creases. Such irons were originally heated using hot coals, but are now more commonly heated using electricity.
But the process of using a household iron is time-consuming, requiring one to remove clothing from its hanger, locate an ironing-board, position the clothing with the portion to be ironed on a flat portion of the board, and finally iron the clothing. This is time-consuming at home, only made worse when traveling. Furthermore, a typical iron requires a large heated plate because a small plate does not provide a stable base for the iron.
The result is that ironing specific sections of an article of clothing is difficult, often requiring the use of different parts of the ironing board to iron different sections of an article of clothing.
What is needed is a low-weight iron that can be used on clothing while it remains hanging, allowing a user to iron specific parts of the clothing without creating creases in unwanted parts.
SUMMARY
The hand-held clothing iron solves the problems of the prior art by providing a clamping iron that is used on an article of clothing while it remains hanging.
Furthermore, the hand-held iron is not limited to applying a single level of heat across its entire surface, but is rather divided into zones.
The first zone is the gather-gap, where clothing is gathered/folded to allow the hand-held iron to reach sections of the article of clothing that are further away than its throat is long.
Past the gather-gap, the pairs of plates are divided into two or more zones, allowing for two or more levels of heating to be applied to the article of clothing. The plates are separated from one another by an insulating material, such as a ceramic. Or the plates are separated merely by an air-gap, the air-gap being of sufficient width to minimize heat transfer. The result of the insulator is to minimize heat transfer between the neighboring plates.
While the use of two pairs of plates is discussed herein, the use of three or more pairs of plates is anticipated.
The benefits of the gather-gap and the multi-zone heating are numerous.
First, the hand-held iron can reach sections of the article of clothing that are further away than the hand-held iron is long, without applying heat to the near portions. The result is fewer creases, without requiring a very long hand-held iron.
Second, the hand-held iron can iron disparate adjacent materials, applying the appropriate level of heat for each material. For example, a high-temperature setting for cotton and a low-temperature setting for synthetic material. Example heat settings include:
Linen: 445° F. Cotton: 400° F. Wool: 300° F. Polyester: 300° F. Silk: 300° F. Lycra/Spandex: 275° F.
Third, if the gather-gap is full of material, and the material to be ironed is still outside of the reach of the near pair of plates, the hand-held iron can still iron distant material without creating creases by leaving the plates adjacent to the gather-gap at ambient temperature, only heating a further set of plates. Such a set-up creates additional reach for the hand-held iron.
The plates are made of a material with a high coefficient of heat transfer, e.g., steel, copper, aluminum, and optionally coated with an anti-static material and/or anti-friction coating, such as Teflon.
The dials used to choose from the multiplicity of heat settings include indications of which heat settings are appropriate for which materials. For example, indications of a heat setting of 1 for synthetics, 2 for silk/wool, and 3 for linen/cotton.
The housing is constructed of a material with a low coefficient of heat transfer to prevent the hot plates from warming the housing and burning the user.
The hand-held iron is anticipated to be powered by household current, although it is anticipated that battery power is possible. If powered by household current, the electrical cord is mounted to the hand-held iron by a swivel, resulting in a cord that is unlikely to tangle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a top view of a first embodiment.
FIG. 2 illustrates a side view of the first embodiment.
FIG. 3 illustrates a view illustrating the first embodiment ironing an exemplary hanging garment.
DETAILED DESCRIPTION
Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.
Referring to FIG. 1 , a top view of the first embodiment of the hand-held iron 1 is shown. The hand-held iron 1 includes a first housing member 2 and a second housing member 4 , each made of a material with a low coefficient of heat transfer to maintain a cool housing.
First plate pair 10 is shown separated from second plate pair 16 by first insulator 20 . First indicator light 30 is lit when first plate pair 10 is energized, and second indicator light 32 is lit when second plate pair 16 is energized.
Alternatively, the indicator lights 30 / 32 may be lit depending not on whether the plates are energized, but whether the plates are above a specified temperature. For example, if the plates 10 / 16 are hot enough to burn the user.
First temperature control 34 sets the temperature for first plate pair 10 , and second temperature control 36 sets the temperature for second plate pair 16 .
First power switch 38 energizes first plate pair 10 , and second power switch 40 energizes second plate pair 16 .
Referring to FIG. 2 , a side view of the first embodiment of the hand-held iron is shown. Here, it is shown that first plate pair 10 is made of two separate plates, Plate- 1 a 11 and Plate- 1 b 12 . Furthermore, second plate pair 16 is shown as made of two separate plates, Plate- 2 a 17 and Plate- 2 b 18 . Plate- 1 a 11 is separated from Plate- 2 a by first insulator 20 . Plate- 1 b 11 is separated from Plate- 2 b by second insulator 20 .
There is no requirement of limiting the plates to only two pairs. Additional pairs may be added, either increasing the length of the hand-held iron, changing the relative length of one pair of plates as compared to another, or increasing the quantity of divisions.
Gathering gap 24 is shown, and as indicated is between the plates 11 / 12 / 17 / 18 and the hinge 26 . The hinge 26 allows the plates to be separated for the introduction of material, and subsequently closed upon the material.
While ironing a garment, it is helpful to identify to the user the location of the respective plates. Thus, a plate separation indicator 50 is provided on the first housing member 2 , and optionally on the second housing member 4 . The plate separation indicator may be raised portion of the housing member 2 / 4 , an applied label, a disparate color of material, a light, or other type of indicator. The intention is to allow the user to visually identify the location of insulators 20 / 22 without requiring rotation of the hand-held iron 1 to view it from the side.
Similarly, it may be helpful to the user to identify which plates 10 / 16 are heated. This is accomplished through the optional first auxiliary indicator light 52 and second auxiliary indicator light 54 . First auxiliary indicator light 50 is lit when first plate pair 10 is energized, and second auxiliary indicator light 52 is lit when second plate pair 16 is energized.
All indicator lights 30 / 32 / 52 / 54 may be of multiple types: simple on/off; color-switching (e.g., red for off and green for on); or color changing (e.g., blue for cool, yellow for warm, orange for warmer, red for hot).
Referring to FIG. 3 , an exemplary view of the first embodiment of the hand-held iron pressing an exemplary hanging garment is shown.
A discussion of specific uses for the hand-held iron 1 illuminates its versatility. An exemplary blouse 60 is shown. The hand-held iron 1 is small enough to be used on the collar 62 of the blouse 60 without needing to remove the blouse 60 from its hanger. Ruffles 64 can be ironed without having to unbutton the blouse 60 , or to lay it on a flat surface, as can cuffs 66 . A user may even reach through the separates created by buttons 72 and iron two disparate materials, such as first material 68 and second material 70 . In the process the hand-held iron allows for the application of the ideal amount of heat for each material, all without requiring an ironing board, or an iron to heat up/cool down when moving from one material to another.
Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.
It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.
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A hand-held clothing iron that solves the problems of the prior art by providing a clamping iron that is used on an article of clothing while it remains hanging, including the ability to apply disparate levels of heat to different sections of the clothing to provide the ideal temperature for each section.
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This application is a continuation-in-part of the application having Ser. No. 202,200 filed June 3, 1988 now abandoned.
DESCRIPTION
The present invention is in a process of analyzing metal particles for their chemical composition and for generating a sorting signal, so the particles are partly vaporized to form a plasma and the spectral lines of the plasma are analyzed for an identification of the composition of the metal particles.
The known laser-induced breakdown spectroscopy (LIBS) processes are based on the classical spectroscopic process developed by Fraunhofer. In the known processes an electric arc is struck between the material to be analyzed and an electrode, sample material is vaporized and the resulting white light is dispersed by diffraction in a grating. A comparison of the spectrum formed by diffraction with reference spectra and/or a measurement of the wavelength and intensity of individual spectral lines may then be utilized for a qualitative and quantitative determination of the elements contained in the inspected sample. Such a determination can take from minutes to hours depending on the information sought.
In the known LIBS processes a laser beam rather than an electric arc is used and the spectrum, or part of the spectrum, formed by diffraction is detected by a diode array, the output of which is utilized in a multi-channel analyzer. (See also Loree, T. R., Radziemski, L. J.: The identification of impurities in metals by laser-induced breakdown spectroscopy", Proc. Tech. Program-Electro-Opt./Laser Conf. Expo 1081, 28-33).
In that process an analysis can be performed within 1 to 2 seconds, which is sufficiently fast for numerous applications but is too slow for a sorting at a high throughput rate, for instance, in the sorting of shredder scrap. In that case the ferromagnetic fraction is removed by magnetic separation, the non-metallic fraction is separated by sink-float processes and residual scrap is left, which consists of lumps and is composed of about one half of aluminum with the remainder being substantially of zinc, copper, lead and special steel. That unsorted residual scrap has a value from 700.- to 800 DM (Deutschmarks) per 1000 kg and about 2000 DM per 1000 kg when sorted. Since about 170,000 metric tons of such residual scrap are recovered per year in the Federal Republic of Germany alone, the value which can be added by separating the scrap into its individual components or into reusable groups of components is of an order of 200 million DM per year.
Various separating processes have already been proposed in efforts to permit realization of this added value. However, none of these processes has thus far been technologically and economically successful.
It is an object of the invention to improve the process defined first hereinbefore so that it can be used for a sorting at a high throughput rate, e.g., in the sorting of residual scrap outlined hereinbefore. In that case, particles having an average size of from 15 to 65 mm must be separated at a rate of at least 30 particles per second and the cost of the analysis of each particle must be distinctly lower than the value which can be added per particle.
SUMMARY OF THE INVENTION
The above objects and others are obtained by the process of the invention.
In the process of the invention the surface of the metal particles is partly cleaned by laser irradiation and a laser pulse is directed to the purified area to produce a plasma which is characteristic of the composition of the metal particle. Predetermined, selectable wavelengths are filtered from the total radiation of the plasma. Numerical ratios are derived from the radiation intensities of the filtered wavelengths, and a sorting signal is generated in dependence on the comparison of said ratios with adjustable limiting values.
In accordance with further features of the invention, predetermined narrow wavelength ranges rather than individual wavelengths are filtered and/or the radiation of the plasma is used for the analysis only for a predetermined time. The vaporization products formed by the laser irradiation effected for cleaning are suitably removed before the laser is fired to produce a characteristic plasma. More than one ratio may be derived and a plurality of predetermined limiting values may be used for the comparison.
For an analysis of metal particles which differ in size and shape, it is desirable to use a laser optical system which is so designed that the result of the measurement is independent of the distance between the laser source and the particle surface if that distance varies within a defined range. The pulsed laser beam may be initiated by a trigger signal which is generated in response to the entrance of the metal particle into the inspection path. The metal particles may be caused to traverse more than one inspection path in succession.
The evaluation of all measured values and obtained data and the generation of the desired sorting signal are preferably electronically performed. Finally, the process is preferably carried out in such a manner that the plasma radiation generated by the first laser pulse is directed to a metal particle to clean the same and is examined for wavelengths characteristic of aluminum. If the presence of aluminum is detected, the metal particle is not subjected to further laser pulses.
The present invention is also in an apparatus for carrying out the process of the invention and includes means for transporting the singled metal particles along an inspection path; a trigger signal generator comprising a trigger detector and trigger electronics for generating a trigger signal in response to the entrance of a particle into the inspection path; means for partly cleaning the surface of the metal particles by laser beams; a laser for generating pulsed laser beams; one or more spectral filters and spectral detectors associated with the respective filters; electronic circuitry for evaluating and comparing the spectral intensities which have been obtained; and a computer for processing the measured values and data which have been obtained and for generating a sorting signal.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification for a better understanding of the invention, its operating advantages and specific objects obtained by its use, reference should be had to the accompanying drawing and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE FIGURE
FIG. 1 shows an arrangement of apparatus for carrying out the process of the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIG. 1, a belt conveyor 2 moves metal particles 1 along an inspection path which runs perpendicular to the plane of the FIGURE. A trigger laser 3 is provided with a trigger detector 4 and electronic trigger circuitry 5 for detecting the arrival of a metal particle and generating a start signal. A pulsed laser 6 generates a laser beam. The generated laser beam partially cleans the sample material. The beam is directed onto the metal particles 1 by a mirror 8, a focusing lens 9 and mirror 10. The beam is also used for analysis of the sample.
The apparatus also includes a spectral detector 12, which is provided with a pre-arranged spectral filter 11 and an electronic detector circuitry 13. The electronic detector circuitry 13 controls the measuring intervals of the spectral detector 12 and obtains computer-readable measured value data. An evaluating computer 14 derives the ratios of the measured values and compares the derived ratios with predetermined limiting values and generates one or more signals for the control of a sorting apparatus.
There is also an orienting laser 7, which emits a visible laser beam. The beam is focused on the same inspection point as the laser beam of the pulsed laser 6. Alternatively, a second pulse laser may be provided for partly cleaning the metal particles by means of laser pulses.
By an apparatus, not shown, for singling the metal particles 1 the belt conveyor 2 is fed with particles at an average rate of 30 particles per second. The belt 2 feeds the metal particles 1 at a corresponding velocity along the inspection path. When a metal particle enters the optical path of the trigger laser 3, the trigger detector 4 responds by causing the electronic trigger circuitry to generate a start signal for firing the pulsed laser 6. The laser 6 generates a beam which causes the metal particle 1 to be partly cleaned in that it is partly vaporized to form a plasma by means of a predetermined number of laser pulses. A predetermined number of additional laser pulses generates a plasma which is analyzed to determine the metal particle composition. The radiation emitted by that plasma is detected by the spectral detector 12 after a major part of the radiation from the plasma has been eliminated by the spectral filter 11, which transmits only a defined narrow wavelength range. The electronic detector circuit 13 causes the spectral detector 12 to detect the radiation from the plasma only for defined intervals of time so that the background noise of the radiation from the plasma will be minimized and the spectra can be more accurately identified.
If an interval amounting to one-thousandth of a second is available for each inspection, that time interval is utilized approximately as follows in the process in accordance with the invention.
About 5 × 10 -5 seconds pass from the entrance of the metal particle into the beam of the trigger laser until the "shot" of the pulsed laser. Since the laser shot takes only about 1 × 10 -8 seconds, the "cleaning" is completed after about 5 × 10 -5 seconds. The time required for the laser shots used for the analysis is also virtually negligible. The succeeding waiting time before the spectral detector is enabled amounts to about 5 × 10 -7 seconds. 5 × 10 -6 seconds are available for the measuring operation proper. The total time required for the operations described thus far does not exceed 0.6 × 10 -4 seconds so that 9.4 × 10 -4 seconds are available for the computer evaluation. That time is more than sufficient for an evaluation.
The process also provides a time allowance for an operation in which the time interval between consecutive metal particles is distinctly less than 0.03 seconds because a much higher throughput rate is required.
For a better understanding of the timing which has been explained, it may be assumed that the theoretical inspection time interval of 10 -3 seconds corresponds to a distance of 1 meter or 1000 millimeters. In that case a distance of 50 mm would correspond to the time from the entrance of the particle into the beam of the trigger laser and the laser shot. The shot time corresponds to a distance of only 0.1 mm, the waiting time to a distance of 0.5 mm and the measuring time to a distance of 5 mm. About 940 mm are then available for an evaluation.
In view of these short measuring times the result of the measurement is not affected by the movement of the metal particle during the analysis. In the selected arrangement the result of the measurement will also remain unaffected by the fact that the distances between the metal particles being inspected and the laser optical system are different because the metal particles differ in size within limits determined by a classification.
The pulsed laser 6 is preferably a UV-gas-laser. UV-gas-lasers produce plasma from the metal particles on which the pulses are focused, but do not produce plasma from the ambient air. This nearly completely avoids the influence on the analysis of elements not belonging to the sample.
Moreover, only UV-gas-lasers are able to produce spots of equal intensity and extension (of area) independently of repetition time. As the scrap particles are of different size (normally within the range of 15 to 65 mm) small pieces can and must be analyzed faster than larger ones. Therefore, repetition time from piece to piece is not constant but varies continuously and the laser has to be started (by a trigger signal) at different intervals. Other lasers may be started as fast as the UV-laser. However, spot intensity and extension cannot be kept constant, and the result is that the analyzing system receives signals which cannot be used for comparison with given standards. Only UV-gas lasers are able to give more than 10 shots/sec with a repetition time, which is necessary for scrap particles varying of different size. This permits a throughput of the apparatus of 30 metal particles per second.
Another important aspects of the invention is that the plasma of the leaning shot is removed prior to the start of the analyzing shot by application of an air jet. The velocity of the air jet is preferably at least about 10 m/sec. Without this, the analyzing shot would ignite the plasma cloud created by the cleaning shot, and would not produce a plasma of the cleaned metal surface of the particle.
It will be understood that the specification and examples are illustrative but not limitative of the present invention and that other embodiments within the spirit and scope of the invention will suggest themselves to those skilled in the art.
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Disclosed is a process and apparatus to analyze metal particles to determine their composition and to generate a sorting signal. The particles are exposed to a pulsed laser beam by which they are partly vaporized to form a plasma so that the particles are cleaned and the cleaned area is subsequently partially vaporized by a pulsed laser beam to form a plasma. The spectral lines of the plasma are inspected for an identification of the composition of the metal particles. The required inspection rate of 30 particles per second can readily be achieved or even exceeded if a defined narrow wavelength range or a defined wavelength is filtered from the total radiation that is emitted by the plasma and the intensities of the filtered partial radiations are related to each other to obtain ratios, which are compared with adjustable limiting values. A sorting signal is derived from the result of said comparison. The inspection rate can be improved in that the partial radiation is subjected to a comparison only for a defined interval of time.
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CROSS REFERENCE TO RELATED APPLICATIONS
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
BACKGROUND OF THE INVENTION
The present invention relates to industrial control systems, and in particular to industrial control systems where blocks of data are transferred between a central processor and one or more independent input/output (I/O) modules.
Industrial controllers are special purpose computers used for controlling industrial processes for manufacturing equipment. Under the direction of a stored program, the industrial controller examines a series of inputs reflecting the status of the controlled process and changes outputs affecting the control of the process. The inputs and outputs are most simply binary, that is "on" or "off", however, analog inputs and outputs, taking on values in a continuous range are also used. The binary inputs and outputs may be represented by single bits of data, the analog inputs and outputs may be represented by multiple bit data words.
In one common architecture for industrial controllers, a central processor executes a control program during which it reads and writes input and output values from and to an I/O image table. The I/O image table is a local memory that collects the values of all inputs and outputs of the control system and which may be rapidly accessed without the complex communication protocols needed to exchange large blocks of data directly with the I/O modules. Normally, separate circuitry, operating asynchronously to the processor refreshes the I/O image table by communicating with one or more I/O modules in a scanning process. Thus, the I/O image table simplifies and speeds the execution of the control program by the processor.
Most advanced industrial processors also include a provision for the block transfer of data which may or may not be I/O data. In a block transfer, the processor may halt further execution of the control program while a multi-word block of data is transferred to or from one or more I/O modules. Generally the block of data is received or transmitted at a time asynchronous to the execution of the internal program of the I/O modules. For this reason, the I/O modules may read from the area of memory receiving the transferred block of data prior to the transfer being complete. Similarly, in the case of data being transmitted from the I/O module, the I/O module may write to the area of memory from which the block of data is being transmitted, changing portions of that data not yet transmitted while failing to change data already transmitted in the block transfer.
Generally this is not a problem when the block of data represents I/O values which change relatively slowly relative to the block transfer rate and whose values have significance independently. The changing or premature use of such block data, however, can be a significant problem when the data represents configuration data such as, for example, the parameters used in a Proportional/Integral/Derivative control loop ("PID") in an I/O module. Such data if read prematurely (i.e., "new data" overwriting "old data" before the old data is utilized) could cause the I/O module to operate unpredictably.
It is known to use handshaking protocols so that two communicating devices can indicate whether a complete transfer of data has occurred. Unfortunately, such handshaking normally requires specialized circuitry supporting a handshaking communication protocol. Such a protocol can be time consuming when applied to all data in a high speed industrial controller intended for use in real-time control. Further, such circuitry is not provided in many controllers.
What is needed is a block transfer method that ensures the data is not used or changed during the transfer and that can be used with existing controllers without hardware modification.
SUMMARY OF THE INVENTION
The present invention provides a method of transferring blocks of data in an industrial controller without the need for specialized handshaking circuitry yet which ensures that the integrity of the data is preserved. The method uses "dummy" I/O image table values to signal completion of the data transfer. For data to be transmitted by the processor to an I/O module, the processor signals a "download request" with a dummy I/O image table value which is sent to the I/O module according to normal operation. Asynchronously, the I/O module responds by setting a "download acknowledge" dummy I/O image table value which, when asynchronously read by the processor, initiates the transfer. At the conclusion of the transfer the "download request", value is reset which when read by the I/O module indicates that the transfer is complete.
In this way separate handshaking circuitry and specialized bit sequences for handshaking signals are not required.
Specifically the method includes a writing by the processor to the I/O image table of a predetermined data request value under the control of a user written control program and the asynchronous transmission of the predetermined data request value to the I/O module. The I/O module responds to the predetermined data request value by writing to local I/O memory a predetermined data acknowledgment value and asynchronously transmitting the predetermined data acknowledgment value to the I/O image table of the processor. The processor further responds to the predetermined data acknowledgment value by performing a multi-word transmission under the control of the control program to the I/O module and then resets the predetermined data request value which is asynchronously transmitted to the I/O module. The I/O module responds to the resetting of the data request value by resetting the data acknowledgment value in local I/O memory.
Thus, it is one object of the invention to provide integrity in the transmission of multi-word data in an industrial controller without handshaking circuitry and without changing the controller hardware or the processor firmware. The steps performed by the processor may be realized completely in the control program normally written by the end user of the industrial controller. Only small changes in the firmware of the I/O module are required.
It is another object of the invention to add the overhead of handshaking only when needed and not during normal high speed operation of the controller. By implementing the handshaking in the control program itself, it need only be invoked when necessary.
It is yet another object of the invention to provide the necessary signals for handshaking through the use of dummy I/O values which are user accessible. By using I/O values in the I/O image table, special firmware and hardware protocols can be avoided.
The foregoing and other objects and advantages of the invention will appear from the following description. In this description, references are made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration the preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference must be made therefore to the claims for interpreting the scope of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is perspective view of an industrial controller in which various modules including a processor module and at least one I/O module are interconnected in a rack having a common back plane, and showing one I/O module connected to a motor for PID type feedback control;
FIG. 2 is a block diagram of the elements of the processor and I/O module of FIG. 1 showing an I/O image table used by the processor and a portion of that I/O image table used by the present invention and further showing other memory space allocated for a user program;
FIG. 3 is a fragment of a user program written in relay ladder logic as would be written by the user of the industrial controller of FIG. 1 to provide for a block transfer from the processor of FIG. 2 to the I/O module of FIG. 2 per the present invention;
FIG. 4 is a figure similar to that of FIG. 3 showing a user program written to transfer a block of data from the I/O module of FIG. 2 to the processor module of FIG. 2 per the present invention;
FIG. 5 is a of flowcharts showing programs concurrently executed in the processor module in the I/O module of FIG. 2 using the programs of FIG. 3 to download data per the present invention; and
FIG. 6 is a of flowcharts showing programs concurrently executed in the processor module in the I/O module of FIG. 2 using the programs of FIG. 4 to upload data per the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, an industrial control system 10 includes a set of independent modules 12 received by a rack 14 and interconnected by a common backplane 16 according to methods well known in the art. One module 12 is a processor module 18 executing a control program to control an industrial process 20 indicated for clarity as a single motor 22, via an I/O module 24. The I/O module 24 receives electrical inputs from the process 20 and providing electrical outputs to the process 20 via I/O lines 26. The rack 14 may include a power supply and other modules as are well known in the art. Such industrial controllers 10 are available commercially from the Rockwell Automation Division of Rockwell under the trade name 1746SLC Industrial Controller.
Referring now to FIG. 2, the processor module 18 includes a microprocessor 28 communicating on an internal bus 30 with the backplane 16 via communication circuitry (not shown) and with memory including a program memory holding a user written program 32 typically written in relay logic language, a general purpose memory 34 and a I/O image table 36. As is known in the art, the I/O image table 36 provides a mapping of all input and output to the industrial controller 10 from and to its various I/O modules 24 for use by the microprocessor 28 in executing the user written program 32. The I/O image table 36 is updated asynchronously and "invisibly" to the microprocessor 28 by scanning circuitry 31.
The I/O module 24 includes a microprocessor 38 communicating on an internal data bus 40 with the backplane 16 via interface circuitry (not shown) and with memories including a general purpose memory 42 holding input and output values unique to the I/O module 24 and a program memory holding the internal program 44 of the I/O module 24 in "firmware". This latter memory is typically non-volatile read-only memory and is programmed at the factory.
The I/O lines 26 from the controlled process 20 are received by I/O interface circuitry 46 in the I/O module as is well known in the art, and communicated along the bus 40 for storage in the general purpose memory 42 and/or processing by the microprocessor 38. Scanning circuitry 39 operating in response to the operation of the scanning circuitry 31 in the processor module 18, exchanges data between the general purpose memory 42 to the I/O image table 36 of the processor module 18 asynchronously to the operation of the I/O module 24 microprocessor 38 to update the I/O image table 36 with input data or download output data to the general purpose memory 42.
Referring still to FIG. 2, normally the I/O image table 36 holds data reflecting the actual state of the controlled process 20 as may be reflected in electrical signals on I/O lines 26. In the present invention, however, four dummy I/O values 48 are reserved within the I/O image table 36 for use in transferring data between the processor module 18 and the I/O module 24. These values are termed "dummy" values because they do not correspond to any actual I/O value. Nevertheless, these dummy I/O values 48 may be manipulated by the user written program 32 like any other I/O value and are automatically asynchronously transferred along the backplane 16 between the I/O image table 36 and the general purpose memory 42 of the various I/O modules. Similarly, the microprocessor 38 of the I/O module 24 may read and manipulate these dummy I/O values 48 as if they were actual I/O values.
The I/O image table 36 is generally divided into input values received from the I/O modules 24 indicating electrical signals received from the controlled process 20 and output values transmitted to the I/O modules 24 to provide electrical signals to the control process 20. In the present invention, two dummy I/O values 48 are provided in the output portion of the I/O image table 36 abbreviated as DN LD REQ (meaning "down load request") and UP LD REQ (meaning "up load request"). In addition, two input dummy I/O values 48 are used in the present invention DN LD ACK (meaning "down load acknowledge") and UP LD ACK (meaning "up load acknowledge").
Referring now to FIGS. 2, 3 and 5, a portion of the present invention is implemented by the user written program 32 executed by the processor 18 and a portion of the present invention is implemented by the firmware program 44 running in the I/O module 22.
When it is desired to download a block of data from the processor 18 to the I/O module 24, the dummy values of DN LD REQ and DN LD ACK are used. Alternatively, when it is desired to up load a block of data from the processor 18 to the I/O module 24, the dummy values of UP LD REQ and UP LD ACK are used. FIGS. 3 and 5 are applicable to uploading and FIGS. 4 and 6 are applicable to downloading.
Considering first a downloading, in a first step of a portion of the user written program 32 used for this purpose, shown in FIG. 3, a predicate condition 50 to the block/file transfer must be true (as indicated by process block 52 of FIG. 5). This predicate condition is determined by the user according to the purpose for which the data will be downloaded but may be, for example, an indication that initialization of the I/O modules 24 is required, such as providing to I/O module 24 its operating parameters of PID gains in a conventional PID control loop. The predicate condition 50 will consist of one or more contacts in a relay ladder rung. The determination of the satisfaction of the predicate condition 50 is indicated by decision block 52.
When the predicate condition 50 is true, the DN LD REQ value of the dummy I/O values 48 is set as indicated by the latching relay symbol in the first line of the relay ladder code of FIG. 3 and process block 54 in FIG. 5. This setting operation changes the value of the DN LD REQ output value in the I/O image table 36 whose contents are asynchronously transmitted 56 over the backplane from the I/O image table 36 to general purpose memory 42 of the I/O module 24.
Sometime later, as determined by the normal execution of program 44 by microprocessor 38 in I/O module 24, the setting of the DN LD REQ bit it detected is indicated by decision block 58 of FIG. 5. The following decision block 57 detects the setting of the DN LD REQ bit and causes the program 32 to branch around remaining blocks 61, 62, and 66 as will be described only if the DN LD REQ bit is not set.
If the DN LD REQ output value is detected at decision block 58, the program 44 of the I/O module 24 proceeds to process block 60 and in the general purpose memory 42 the DN LD ACK input value is set. The program 44 also causes and data in the general purpose memory 42 susceptible to the block/file transfer to be locked, meaning that it is neither used by other parts of the program 44 as indicated by the branching around process block 63 to be described below.
Data that may be subject to the block/file transfer of the present invention is in a defined memory location of general purpose memory 42 to be recognized by the program 44 and typically unique to the I/O module 24. For example, a special area of general purpose memory 42 for the operating parameters of the PID loop may be designated at the time of manufacture of the I/O module 24 and the address range of this area programmed into program 44.
The setting of the DN LD ACK input value is asynchronously transmitted 59 to the I/O image table 36 with all other input data as part of the scanning process where it is detected by the processor module 18 as indicated by decision block 61 immediately following decision block 57.
Referring to FIG. 3, this detection is better understood at the second rung of the ladder logic program of FIG. 3 where the first contact is closed as a result of the setting of the DN LD REQ output value but the entire rung is not true until the setting of the DN LD ACK input value. The program proceeds to the third rung until the DN LD ACK input value is set.
Once the DN LD ACK input value is set, both contacts in series on the second rung of FIG. 3 are closed and the block/file transfer routine executes as indicated by process block 62, following process block 61 in FIG. 5. This block/file transfer routine is preprogrammed into most commercial industrial controllers. During the execution of the block/file transfer, further scanning of the rungs of FIG. 3 ceases.
Upon completion of the block/file transfer, the program 32 resumes execution at the third rung of FIG. 3. Here because the DN LD ACK input value and DN LD REQ output value are set, the rung executes and the DN LD REQ output value is reset as indicated by process block 66 of FIG. 5.
This reset value is transmitted 68 to the I/O image table 36 to general purpose memory 42 of the I/O module 24 where it is detected by decision block 58 causing the program to advance to decision block 68 where the value of DN LD ACK is checked. If DN LD ACK is set, the I/O module 24 effectively unlocks the data in general purpose memory 42 as indicated by process block 63 which permits processing of the affected data normally. Sometime later at process block 74, the I/O module resets the DN LD ACK input value thus completing the transfer process. This value is transmitted 75 to be detected at process block 61 of program 32.
As can be seen, the communication 56, 59, 64, 68 and 75 need not be synchronized to the operation of the I/O module 24 yet ensures that the I/O module 24 does not prematurely use or change the data being transferred.
Referring now to FIG. 4, the same procedure may be used for a processor 18 initiated uploading of data with the use of the UP LD REQ output value and UP LD ACK input value instead of the DN LD REQ output value and DN LD ACK input value. The program 32 at the processor is exactly analogous with blocks 52', 54', 57', 61', 62', and 66' corresponding to blocks 52, 54, 57, 61, 62, and 66 previously described. In the program 44 blocks 58', 60' 70', 72', and 74' are analogous to blocks 58, 60 70, 72, and 74 with the following exceptions: at process block 74' UP LD REQ is reset and at process block 60' UP LD ACK is set and at decision block 58' a branch is made to process block 74' only if UP LD REW is set and otherwise the program 44 proceeds to decision block 70'.
The block/file transfer predicate condition 76 shown in FIG. 4 as contact 76 triggers a setting of the UP LD REQ output value when an acknowledgment through the UP LD ACK input value is received. Then at the second rung of FIG. 4, the block/file transfer (this time from the I/O module 24 to the processor 18) is initiated. Upon completion of that transfer, with the UP LD ACK and UP LD REQ values set, the UP LD REQ output value may be reset as indicated by the third rung of FIG. 4.
The above description has been that of a preferred embodiment of the present invention. It will occur to those who practice the art that many modifications may be made without departing from the spirit and scope of the invention. In order to apprise the public of the various embodiments that may fall within the scope of the invention the following claims are made.
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A communication protocol employing dummy input and output values is used in communicating blocks of data between an industrial controller and its I/O modules while preventing premature use of partially transmitted data by the I/O modules yet without the need for special handshaking type circuitry or the continuous overhead of such handshaking protocols.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/758,349, filed on Apr. 12, 2010, entitled, “Emotivity and Vocality Measurement,” which claims priority from U.S. Provisional Pat. App. Ser. No. 61/168,618, filed on Apr. 12, 2009, entitled “Emotivity and Vocality Measurement,” both of which are hereby incorporated by reference herein.
BACKGROUND
[0002] All businesses desire to increase the loyalty of their customers because it is well-recognized that increasing loyalty leads to increased profits. Most businesses, however, find increased customer loyalty to be an elusive goal. It is difficult to increase loyalty in a business or other relationship not only because it can be challenging to identify the concrete actions that need to be taken to increase such loyalty, but also because it can be difficult even to measure the current loyalty of a customer or other party to the relationship. Failure to obtain a concrete and objective measurement of current loyalty will almost certainly lead to an inability to identify those concrete actions which are likely to increase such loyalty most efficiently.
[0003] Prior art techniques for measuring loyalty often require information about existing business relationships to be provided in the form of structured quantitative data, such as numerical answers to predetermined survey questions. Such techniques have limited usefulness, however, because it can be difficult and time-consuming to obtain such structured quantitative data from partners to a relationship. What is needed, therefore, are techniques for measuring loyalty based on unstructured and/or non-quantitative data, such as letters, email messages, blog entries, and other documents written by partners to a relationship.
SUMMARY
[0004] One embodiment of the present invention is directed to a computer-implemented system that analyzes free-form text comments provided by a user (such as a customer of a company) and draws conclusions about the tone of the user's feedback, such as whether the user's feedback is positive, negative, angry, critical, or congratulatory. Such conclusions may be reflected in a single numerical value referred to herein as “emotivity.” A customer's emotivity score may be used for various purposes, such as determining whether the customer is likely to provide a positive testimonial for the company, or whether a follow-up phone call should be made to the customer to improve the company's relationship with the customer. Furthermore, a measurement of the customer's loyalty to the company may be modified based on the user's measured emotivity.
[0005] In another embodiment of the present invention, a computer-implemented system analyzes free-form text comments provided by a user (such as a customer of a company) and draws conclusions about the opinions of the user based on the number of words in the user's comments, measured either as an absolute quantity or relative to a baseline, such as the average number of words in comments received from a plurality of users. A visual indication of the user's vocality may be displayed, such as a bullhorn with lines emanating from it, where the number of lines corresponds to the user's vocality. Furthermore, a measurement of the user's loyalty may be modified based on the user's vocality.
[0006] Measures of vocality and emotivity may be presented relative to each other. For example, if the user's input indicates that he has a negative opinion of the other party to the relationship, then the user may be deemed a “detractor” of the other party. Conversely, if the user's input indicates that he has a positive opinion of the other party to the relationship, then the user may be deemed an “advocate” of the other party. Such conclusions about the user may be combined with the user's vocality score to produce labels for the user such as “Non-Vocal,” “Vocal” (e.g., if the user's input contains a large number of words that do not indicate either a positive or negative opinion of the other party), “Vocal Detractor” (if the user's input contains a large number of words indicating a negative opinion of the other party) and “Vocal Advocate” (if the user's input contains a large number of words indicating a positive opinion of the other party).
[0007] For example, one embodiment of the present invention is directed to a computer-implemented method comprising: (A) providing a survey to a plurality of people, the survey comprising a plurality of questions; (B) receiving, from the plurality of people, a plurality of sets of answers to the plurality of questions; (C) identifying a plurality of loyalty indices of the plurality of people based on the plurality of sets of answers; (D) for each of the plurality of people U: (D) (1) identifying text input T associated with person U; (D)(2) identifying a count E of words in text input T which are in a set of words representing strong emotions; (D)(3) identifying a count P of words in text input T which are in a set of words representing positive emotions; (D)(4) identifying a count N of words in text input T which are in a set of words representing negative emotions; and (E) selecting values of coefficients A, B, and C that maximize a value of R 2 between the plurality of loyalty indices and values of a variable Emo for the plurality of people, wherein Emo=A*E+B*P+C*N.
[0008] Another embodiment of the present invention is directed to a computer-implemented method comprising: (A) identifying a plurality of loyalty levels of a plurality of people; (B) identifying a plurality of text inputs provided by the plurality of people; (C) identifying a first subset of the plurality of people having loyalty levels satisfying a high loyalty level criterion; (D) identifying a second subset of the plurality of people having loyalty levels satisfying a low loyalty level criterion; (E) identifying a third subset of the plurality of people having loyalty levels not satisfying the high loyalty level criterion or the low loyalty level criterion; (F) identifying a first subset of the plurality of text inputs comprising text inputs provided by the first subset of the plurality of people and text inputs provided by the second subset of the plurality of people; (G) identifying a second subset of the plurality of text inputs comprising text inputs provided by the second subset of the plurality of people; and (H) identifying a third subset of the plurality of text inputs comprising the relative complement of the second subset of the plurality of text inputs relative to the first subset of the plurality of text inputs.
[0009] Yet another embodiment of the present invention is directed to a computer-implemented method comprising: (A) identifying a set of words representing strong emotions; (B) identifying a set of words representing positive emotions; (C) identifying a set of words representing negative emotions; (D) identifying first text input T 1 associated with a person; (E) identifying a first count E 1 of the strong emotion words in text input I 1 ; (F) identifying a first count P 1 of the positive emotion words in text input I 1 ; (F) identifying a first count N 1 of the negative emotion words in text input I 1 ; and (G) identifying a first value V 1 representing an emotional content of text input I 1 based on E 1 , P 1 , and N 1 .
[0010] Yet a further embodiment of the present invention is directed to a computer-implemented method comprising: (A) receiving, from a plurality of people, a plurality of text inputs having a plurality of sizes; (B) identifying a statistic derived from the plurality of sizes; (C) selecting one of the plurality of text inputs I 1 from one of the plurality of people P; (D) identifying a size of text input I 1 ; and (E) selecting a measurement V 1 associated with person P based on the size of text input I 1 and the statistic derived from the plurality of sizes.
[0011] Another embodiment of the present invention is directed to a computer-implemented method comprising: (A) identifying text input T associated with a person; (B) counting a number of words W in the text input T; (C) providing, on an output device, a visual representation of W, comprising: (C)(1) identifying a range of values encompassing W; and (C)(2) identifying a visual representation corresponding to the range of values.
[0012] Other features and advantages of various aspects and embodiments of the present invention will become apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a dataflow diagram of a system for calibrating a system for identifying the emotivity of a user according to one embodiment of the present invention;
[0014] FIG. 2 is a flowchart of a method performed by the system of FIG. 1 according to one embodiment of the present invention;
[0015] FIG. 3 is a dataflow diagram of a system for generating a list of words connoting strong emotions according to one embodiment of the present invention;
[0016] FIG. 4 is a flowchart of a method performed by the system of FIG. 3 according to one embodiment of the present invention;
[0017] FIG. 5 is a dataflow diagram of a system for generating an emotivity score of a user according to one embodiment of the present invention;
[0018] FIG. 6 is a flowchart of a method performed by the system of FIG. 5 according to one embodiment of the present invention;
[0019] FIG. 7 is a dataflow diagram of a system for generating vocality scores for a plurality of users according to one embodiment of the present invention;
[0020] FIGS. 8A-8C are flowcharts of methods performed by the system of FIG. 7 according to various embodiments of the present invention;
[0021] FIGS. 9A-9D are illustrations of icons representing vocality levels according to embodiments of the present invention; and
[0022] FIG. 10 is a flowchart of a method for identifying trends in loyalty of a user over time according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0023] Certain embodiments of the present invention are directed to techniques for identifying a measure of emotion, referred to herein as “emotivity,” associated with text associated with a first person. For example, the first person may be a customer of a company. The customer may provide text related to the customer's relationship to the company in any of a variety of ways. For example, the customer may provide free-form text responses to a survey about the customer's relationship to the company. As other examples, embodiments of the invention may capture text from email messages, blog entries, word processing documents, or other text written by the user, whether or not such text was written with the intent that is be used by embodiments of the present invention. The text obtained by the system, whatever the source of that text may be, may be analyzed to measure the emotivity of the customer in relation to the company. The customer's emotivity may, for example, be used in measuring the customer's loyalty to the company.
[0024] In one embodiment of the present invention, a single value representing the person's emotivity, referred to herein using the variable “Emotivity,” is calculated using a formula of the form represented by Equation 1:
[0000] Emotivity= A*E count+ B*P count+ C*N count Equation 1
[0025] In Equation 1, the variables A, B, and C are coefficients whose values must be initialized. Referring to FIG. 1 , a dataflow diagram is shown of a system 100 that is used in one embodiment of the present invention to automatically generate values for coefficients A, B, and C. Referring to FIG. 2 , a flowchart is shown of a method 200 that is performed by the system 100 of FIG. 1 according to one embodiment of the present invention. A survey engine 102 provides a survey 104 , containing questions 104 relating to the practices and perceptions of partners to a relationship (such as business partners), to a plurality of users 106 ( FIG. 2 , step 202 ). The users 106 may, for example, be customers of a particular company.
[0026] The survey 104 may include two kinds of questions: (1) questions 104 N calling for numeric responses, and (2) questions 104 T calling for free-text responses. Examples of techniques for providing surveys calling for numeric responses are disclosed in above-referenced patent application Ser. No. 61/168,618. As disclosed therein, the questions 104 N calling for numeric responses may, for example, each provide a statement and prompt the users 106 to provide a number indicating their degree of agreement with the statement. For example, a response of “1” may represent “Strongly Disagree,” while a response of “5” may represent “Strongly Agree.” The questions 104 N may be divided into groups of questions corresponding to different dimensions of loyalty, as disclosed in the above-referenced patent application.
[0027] The questions 104 T calling for free-text responses may be provided within the survey 104 in any of a variety of ways. For example, each of the numeric questions 104 N may be followed by a prompt, such as “Comments:” or “Other:”, which calls for the users 106 to provide free-text input relating to the immediately-preceding numeric question. As another example, each group within the numeric questions (corresponding to a loyalty dimension) may be followed by a prompt which calls for the users 106 to provide free-text input relating to the immediately-preceding group of questions. These are merely examples of ways in which the free-text questions 104 T may be provided and do not constitute limitations of the present invention.
[0028] The users 106 provide answers 108 to the surveys 104 . The answers 108 include both numeric answers 106 N and textual answers 106 T of the kinds described above. The answers 108 are received by a loyalty measurement engine 110 (step 204 ), which generates loyalty indices 112 for the users 106 based on the survey answers 108 (step 206 ). Examples of techniques that the loyalty measurement engine 110 may use to generate the loyalty indices 112 are described in the above-referenced patent application. In the particular embodiment illustrated in FIG. 1 , the loyalty measurement engine 110 generates the loyalty indices 112 based solely on the numeric responses 108 N, although this is not a limitation of the present invention.
[0029] A word count engine 114 counts, for each user, the total number of words in the user's answers, as well as the number of occurrences of words representing strong emotions (whether positive, negative, or otherwise), words representing positive emotions, and words representing negative emotions in each of the sets of survey answers 108 to produce words counts 116 a , 116 b , 116 c , and 116 d , respectively (step 208 ). Word counts 116 a include, for each of the users 106 , a count of “strong emotion” words used by that user, referred to herein by the variable Ecount. Similarly, word counts 116 b include, for each of the users 106 , a count of “positive emotion” words used by that user, referred to herein by the variable Pcount. Word counts 116 c include, for each of the users 106 , a count of “negative emotion” words used by that user, referred to herein by the variable Ncount. Word counts 116 d include, for each of the users 106 , a count of the total number of words used by that user.
[0030] The word count engine 114 may generate the word counts 116 by entering a loop over each user U (step 210 ) and identifying text T associated with user U (step 212 ). The text T identified in step 212 may, for example, be the set of all textual responses provided by user U to the survey 104 (i.e., the portion of textual responses 108 T provided by user U) and/or otherwise captured by the system 100 (e.g., from blogs, word processing documents, and email messages). The word count engine 114 may then count, within text T, the total number of words used by user U (step 213 ). The word count engine 114 may then count, within text T, the number of words representing strong emotions to generate a value of Ecount for user U (step 214 ). The word count engine 114 may, for example, determine whether any particular word in text T represents a strong emotion by determining whether the word is contained within a predetermined list 122 a (referred to herein as the “Emo list”) of words representing strong emotions.
[0031] Similarly, the word count engine 114 may count, within text T, the number of words representing positive emotions to generate a value of Pcount for user U (step 216 ). The word count engine 114 may, for example, determine whether any particular word in text T represents a positive emotion by determining whether the word is contained within a predetermined list 122 b (referred to herein as the “Positive list”) of words representing positive emotions. Finally, the word count engine 114 may count, within text T, the number of words representing negative emotions to generate a value of Ncount for user U (step 218 ). The word count engine 114 may, for example, determine whether any particular word in text T represents a negative emotion by determining whether the word is contained within a predetermined list 122 c (referred to herein as the “Negative list”) of words representing negative emotions. The word count engine 114 may repeat steps 212 - 218 for the remaining users to complete the generation of counts 116 a , 116 b , and 116 c (step 220 ).
[0032] The system 100 includes a calibration engine 118 which assigns values to a set of emotivity calibration parameters 120 based on the values of the word counts 116 (step 222 ). The calibration parameters 120 may include, for example, the coefficients A, B, and C of Equation 1 (represented in FIG. 1 by elements 120 a , 120 b , and 120 c ). In one embodiment, the calibration engine 120 assigns values to coefficients 120 a , 120 b , and 120 c that maximize the R 2 in a multivariate regression of the plurality of loyalty indices 112 against the values of Emotivity (calculated using Equation 1) for all users 106 .
[0033] As described above, the method 200 of FIG. 2 counts the number of occurrences of words that represent strong emotions, positive emotions, and negative emotions. As further described above, the method 200 may perform this function by using predetermined lists 122 a , 122 b , and 122 c of words representing strong, positive, and negative emotions, respectively. Referring to FIG. 3 , a dataflow diagram is shown of a system 300 that is used in one embodiment of the present invention to generate the Emo list 122 a . Referring to FIG. 4 , a flowchart is shown of a method 400 that is performed by the system 300 of FIG. 3 according to one embodiment of the present invention.
[0034] A loyalty level engine 306 identifies loyalty levels 308 of a plurality of users 302 based on input 304 provided by the users 302 ( FIG. 4 , step 402 ). Note that the users 302 in FIG. 3 may be, but need not be, the same users 106 as those shown in FIG. 1 . Furthermore, the input 304 in FIG. 3 may be, but need not be, the survey responses 108 shown in FIG. 1 . In the embodiment illustrated in FIG. 3 , the input 304 includes both numeric input 304 a and textual input 304 b , which may correspond to the numeric responses 108 N and the textual responses 108 T, respectively, shown in FIG. 1 . Note, however, that the textual input 304 b may come from sources in addition to or instead of the textual survey responses 108 T. For example, the textual input 304 b may include word processing documents, email messages, web pages, or any other text created by or otherwise associated with the users 302 . Furthermore, the textual input 304 b need not be provided by the users 302 at the same time as the non-textual input 304 a . For example, the users 302 may first provide the non-textual input 304 a , and later provide the textual input 304 b . Furthermore, the users 302 may provide different parts of the textual input 304 b at different times.
[0035] The loyalty level engine 306 may, for example, identify the loyalty levels 308 based solely on the numeric input 304 a . Examples of techniques that may be used by the loyalty level engine 306 to generate the loyalty levels 308 are disclosed in the above-referenced patent application Ser. No. 12/535,682. Furthermore, although the present discussion refers to loyalty levels, the techniques of FIGS. 3 and 4 may be applied to loyalty indices, such as the kind disclosed in patent application Ser. No. 12/535,682.
[0036] A loyalty level filter 310 identifies a set of loyalty levels 312 a satisfying a predetermined high-loyalty level condition (step 404 ). For example, assume for purposes of the following discussion that the loyalty-level numbering scheme disclosed in the above-referenced patent application is used, in which there are four loyalty levels representing increasing degrees of loyalty in the following sequence: −1, 1, 2, and 3. In step 404 , users having a loyalty level of 3, for example, may be identified as the high-loyalty users 312 a.
[0037] The loyalty level filter 310 also identifies a set of loyalty levels 312 b satisfying a predetermined low-loyalty level condition (step 406 ). For example, users having a loyalty level of −1 according to the labeling scheme described above may be identified in step 406 as the low-loyalty users 312 b.
[0038] The loyalty level filter 312 also identifies a set of loyalty levels 312 c which do not satisfy either the high-loyalty or low-loyalty conditions (step 408 ). For example, users having a loyalty level of 1 or 2 according to the labeling scheme described above may be identified in step 408 as the “remainder” or “non-emotive” users 312 c.
[0039] The system 300 identifies “emotive” users 316 as the union 314 of the high-loyalty level users 312 a and low-loyalty level users 312 b (step 410 ).
[0040] Note that the loyalty levels 308 may include pointers (not shown) back to the text input 304 b provided by the corresponding one of the users 302 . As a result, the various filtered loyalty levels 312 a - c may be used to identify the corresponding text inputs 304 b of the users having those loyalty levels. A text identifier 318 identifies a set of “emotive” text 320 a as the set of all text input (in text input 304 b ) provided by users in the set of emotive users 316 (step 412 ). The text identifier identifies a set of “non-emotive” text 320 b as the set of all text input (in text input 304 b ) provided by users in the set of non-emotive users 312 c (step 414 ).
[0041] The “Emo list” 122 a is identified as the set of text which occurs in the emotive text 320 a but not in the non-emotive text 320 b , in other words, as the relative complement 322 of the non-emotive text 320 b in the emotive text 320 a (step 416 ).
[0042] The positive list 122 b and negative list 122 c ( FIG. 1 ) may also be generated in any of a variety of ways. For example, the positive list 122 b may be generated by selecting an initial set of words (e.g., from a dictionary) representing positive emotions, and then expanding the initial list to create the positive list 122 b by adding synonyms (e.g., from a thesaurus) of the initial set of positive words. Similarly, the negative list 122 c may be generated by selecting an initial set of words (e.g., from a dictionary) representing negative emotions, and then expanding the initial list to create the negative list 122 c by adding synonyms (e.g., from a thesaurus) of the initial set of negative words. The positive list 122 b and/or negative list 122 c may be customized in a variety of ways, such as by tailoring them to a particular industry and/or company.
[0043] As mentioned above, various embodiments of the present invention may be used to generate an emotivity score for a user based on textual input provided by the user. For example, Equation 1 may be used to generate an emotivity score, represented by the value of the variable Emotivity, for a user based on the values of the coefficients A, B, and C, and the word counts ECount, PCount, and Ncount for that user. Referring to FIG. 5 , a dataflow diagram is shown of a system 500 for generating an emotivity score 512 for a user 502 in this manner according to one embodiment of the present invention. Referring to FIG. 6 , a flowchart is shown of a method 600 performed by the system 500 of FIG. 5 according to one embodiment of the present invention.
[0044] A user 502 provides textual input 504 to the system 500 ( FIG. 6 , step 602 ). The textual input 504 may take any form, such as free-form text responses to a survey, email messages, web pages, word processing documents, or any combination thereof. Note that if the textual input 504 is part of the free-text survey responses 108 T shown in FIG. 1 , the calibration process illustrated in FIGS. 1 and 2 may be integrated with the emotivity score generation process illustrated in FIGS. 5 and 6 , such that the same set of user inputs 108 is used both to calibrate the system 100 and to generate emotivity scores for the users 106 of the system 100 .
[0045] Note, however, that the user 502 need not have provided any of the survey responses 108 shown in FIG. 1 . Furthermore, the emotivity score 512 of the user 502 may be identified using the system 500 of FIG. 5 even if the loyalty level and/or loyalty index of the user 502 is unknown. All that is required from the user 502 to identify the user's emotivity score 512 is the user's textual input 504 .
[0046] A word count engine 506 produces a count 508 a of emotive words (step 604 a ), positive words (step 604 b ) and negative words (step 604 c ) in the users' input 504 . The word count engine 506 may produce the word counts 508 a - c by, for example, counting the frequencies of occurrence of words in the emo list 122 a , positive list 122 b , and negative list 122 c , respectively, in the user's textual input 504 .
[0047] An emotivity engine 510 generates the emotivity score 512 for the user 502 based on the word counts 508 a - c and the emotivity calibration parameters 120 shown in FIG. 1 (step 606 ). As described above, the emotivity calibration parameters 120 may, for example, be the coefficients A, B, and C in Equation 1. Furthermore, the counts 508 a , 508 b , and 508 c may be the variables Ecount, PCount, and NCount in Equation 1. Therefore, the emotivity engine 510 may generate the emotivity score 512 for the user 502 by calculating Equation 1, which applies a linear weighting of the counts 508 a - c , using coefficients A, B, and C as weights.
[0048] Various embodiments of the present invention may be used to measure the “vocality” of a user. The term “vocality,” as used herein, refers generally to the absolute and/or relative size of the input provided by the user, such as the number of words, characters, or sentences provided by the user in response to a survey. The user may, for example, provide such input in the form of typed free-form text, such as text provided in response to survey questions. The user may, however, provide such input in other ways, such as by selecting pre-written sentences or paragraphs from a library of text responses.
[0049] The vocality of a particular user may, for example, be represented as a single number V, such as the number of words W in the user's input. A user's vocality may, however, be a function of W and/or other values derived from input provided by the user and/or other users. For example, once the number of words W provided by the user has been counted, the user's vocality V may be obtained as a function of W. Such a function may take any of a variety of forms. For example, the function may map some fixed number of non-overlapping ranges of W to the same number of vocality values. For example, the ranges W<10, 10<=W<50, 50<=W<500, and 500<=W may be mapped to four distinct values of V. Such vocality values may take any form, such as whole numbers (e.g., 1, 2, 3, and 4, respectively) or text labels, such as “Non-Vocal,” “Mildly Vocal,” “Very Vocal,” and “Extremely Vocal.” The user's vocality may be absolute or relative. For example, it may represent the absolute number of words in the user's input, or a relationship of the number of words in the user's input to a baseline, such as the average number of words in input received from a plurality of users. In the latter case, the user's vocality score may be represented in any of a variety of ways, such as a value representing the number of words (positive or negative) by which the number of words used by the user deviates from the baseline, the percentage (positive or negative) by which the number of words used by the user deviates from the baseline, or a range within which the user's vocality falls relative to the baseline (e.g., low, medium, or high).
[0050] A user's vocality score may be combined with analysis of the content of the user's input. For example, if the user's input indicates that he has a negative opinion of the other party to the relationship, then the user may be deemed a “detractor” of the other party. Conversely, if the user's input indicates that he has a positive opinion of the other party to the relationship, then the user may be deemed an “advocate” of the other party. Such conclusions about the user may be combined with the user's vocality score to produce labels for the user such as “Non-Vocal,” “Vocal” (e.g., if the user's input contains a large number of words that do not indicate either a positive or negative opinion of the other party), “Vocal Detractor” (if the user's input contains a large number of words indicating a negative opinion of the other party) and “Vocal Advocate” (if the user's input contains a large number of words indicating a positive opinion of the other party).
[0051] A user interface may be provided which displays information representing the user's vocality score. The visual display of the user's vocality score may take any of a variety of forms, such as the user's raw or normalized vocality score itself, the text label corresponding to the user's vocality score (e.g., “Vocal Advocate”), or a graphical icon representing the user's vocality score. For example, the graphical icon may be a megaphone from which zero or more lines emanate, where the number, size, or shape of the lines emanating from the megaphone correspond to the user's vocality score. Such an icon provides a visual indication of the user's vocality score that can be understood at a glance.
[0052] Having described the concept of vocality generally, various techniques for measuring the vocality of one or more users will now be described according to embodiments of the present invention. For example, referring to FIG. 7 , a dataflow diagram is shown of a system 700 for measuring the vocality of a plurality of users 702 according to one embodiment of the present invention. Referring to FIGS. 8A-8B , flowcharts are shown of a method 800 performed by the system 700 of FIG. 7 according to one embodiment of the present invention.
[0053] The users 702 provide textual input 704 to the system 700 ( FIG. 8A , step 802 ). The textual input 704 may take any form, such as free-form text (such as responses to a survey), email messages, web pages, word processing documents, or any combination thereof. The textual input 704 may, for example, be part of the free-text survey responses 108 T shown in FIG. 1 , in which case the vocality measurement process 800 illustrated in FIGS. 7 and 8 A- 8 C may be integrated with the calibration process 100 illustrated in FIGS. 1 and 2 , and/or with the emotivity score generation process 600 illustrated in FIGS. 5 and 6 , such that the same set of user inputs 108 is used to calibrate the system 100 of FIG. 1 , to generate emotivity scores, and to generate vocality scores.
[0054] Note, however, that the users 702 shown in FIG. 7 need not have provided any of the survey responses 108 shown in FIG. 1 . Furthermore, although the vocality scores 712 shown in FIG. 7 are generated using information in addition to the users' textual input 704 , this is not a requirement of the present invention. Rather, all that is required from the users 702 to identify the users' vocality scores 712 are the users' textual input 704 .
[0055] A word count engine 706 produces various counts 708 a - d of words in the users' textual input 704 . More specifically, in the particular example illustrated in FIGS. 7 and 8 A- 8 C, the word count engine 706 counts the number of words provided by each of the users 702 in response to one or more questions which prompted the users 702 to describe positive aspects of the users' relationship partners (step 804 a ). For example, consider a survey question such as, “What does your partner do well, that you would like him or her to continue to do?” Such a question solicits positive information about the user's relationship partner. In step 804 a , the word count engine 706 may count the number of words in the textual input 704 provided by each of the users 702 in response to such a question, to produce what are referred to herein as a count of the “best” words for each of the users 702 . If the survey includes multiple such questions, then each user's “best count” may be equal to the aggregate number of words provided by the user in response to all such questions.
[0056] Similarly, the word count engine 706 counts the number of words provided by each of the users 702 in response to one or more questions which prompted the users 702 to describe negative aspects of the users' relationship partners (step 804 b ). For example, consider a survey question such as, “What does your partner not do well, that you would like him or her to improve?” Such a question solicits negative information about the user's relationship partner. In step 804 b , the word count engine 706 may count the number of words in the textual input 704 provided by each of the users 702 in response to such a question, to produce what are referred to herein as a count of the “worst” words for each of the users 702 . If the survey includes multiple such questions, then each user's “worst count” may be equal to the aggregate number of words provided by the user in response to all such questions.
[0057] Similarly, the word count engine 706 counts the number of words provided by each of the users 702 in response to one or more open-ended questions (step 804 c ). For example, consider a survey question such as, “Is there any other information you would like to provide about your relationship partner?” Such a question solicits open-ended information about the user's relationship partner. In step 804 c , the word count engine 706 may count the number of words in the textual input 704 provided by each of the users 702 in response to such a question, to produce what are referred to herein as a count of the “open” words for each of the users 702 . If the survey includes multiple such questions, then each user's “open count” may be equal to the aggregate number of words provided by the user in response to all such questions.
[0058] Input may be identified as being associated with positive, negative, or open-ended information even if such information was not provided in response to survey questions. Rather, any technique may be used to identify input from the users 702 as providing positive, negative, or open-ended information and to count the number of words in such input. For example, the input that is used in steps 804 a - c above may be drawn from email messages, word processing documents, web pages, or other data created by the users 702 . Furthermore, the word count engine 706 may count any subset of the input provided by the users 702 . For example, if the users' input 704 is a set of survey responses which include both multiple-choice responses and free text responses, the word count engine 506 may be configured only to count words in the user's free text responses.
[0059] The word count engine 706 sums the positive, negative, and open-ended word counts 708 a - c to produce net word counts 708 d for each of the users 702 (step 804 d ). Note that although in the embodiment illustrated in FIGS. 7 and 8 A- 8 C, the net word count 708 d for a particular user is the sum of three other word counts 708 a - c , this is merely an example and does not constitute a limitation of the present invention. Rather, the net word count 708 d may be a sum of any number of other word counts. Furthermore, the component word counts need not represent positive, negative, and open-ended information. Rather, each of the component word counts may be defined to correspond to any desired kind of information.
[0060] The users' vocality scores 712 may be derived from the word counts 708 a - d and, optionally, from loyalty levels 716 produced by the loyalty level engine 306 based on input 714 provided by the users 714 in the manner described above with respect to FIGS. 3 and 4 (step 806 ). The input 714 that is used to identify the users' loyalty levels 716 may be, but need not be, the same as the input 704 provided to the word count engine 706 . For example, the users 702 may be provided with a set of surveys, the answers to which may be used to derive the users' loyalty levels 716 , emotivity scores 512 , and vocality scores 712 . Alternatively, however, the loyalty levels 716 , emotivity scores 512 , and vocality scores 712 may be derived from separate sets of inputs. For example, the loyalty levels 716 may be derived from answers to surveys, while the emotivity scores 512 and vocality scores 712 may be derived from free-text in email messages, word processing documents, and blog entries.
[0061] A statistics engine 718 generates, for each loyalty level, statistics 720 a - d derived from the word counts 708 a - d (step 808 ). In the example shown in FIG. 7 , the statistics 720 a - d include, for each loyalty level, the means and standard deviations of the corresponding word counts 708 a - d . For example, statistics 720 a include means 722 a and 722 d , derived from the “best” word counts 708 a . Assuming that there are four loyalty levels, means 722 a include four means: the mean of the best word counts for users with loyalty levels of −1, 1, 2, and 3, respectively. Similarly, standard deviations 722 b include four standard deviations: the standard deviations of the best word counts for users with loyalty levels of −1, 1, 2, and 3, respectively.
[0062] Similarly, statistics 720 b include means 726 a and standard deviations 726 b , derived from “worst” word counts 708 b ; statistics 720 c include means 730 a and standard deviations 730 b , derived from “open” word counts 708 c ; and statistics 720 c include means 734 a and 734 b , derived from “open” word counts 708 c . The statistics engine 718 also identifies statistics 720 e (including means 738 a and standard deviations 738 b ) of the net word counts 708 d across all users 702 (step 810 ). Note that all of these statistics 720 a - e are merely examples and do not constitute limitations of the present invention; other statistics may be used to perform the functions described herein as being performed by the statistics 720 a - e.
[0063] Referring to FIG. 8B , a vocality engine 740 generates vocality scores 712 for the users 702 as follows (step 812 ). For each user (step 814 ), the vocality engine 740 identifies the user's loyalty level (step 815 ). The method 800 then identifies the user's vocality score based on the user's loyalty level (step 816 ). Examples of techniques that may be used to compute the user's vocality score are described below with respect to FIGS. 8B and 8C . The vocality scores for the remaining users may be computed by repeating steps 815 - 816 (step 817 ).
[0064] Referring to FIG. 8B , a flowchart is shown of one method that may be used to identify a user's vocality score, assuming that the user's loyalty level is known. If the user's loyalty level is −1 (step 818 ), then: (1) if the user's worst word count 708 b is one standard deviation 726 b or more above the mean 726 a for users having a loyalty level of −1 (step 820 ), then a vocality score of “Vocal Detractor” is assigned to the user (step 822 ); (2) otherwise, if the user's net word count 708 d is one standard deviation 734 b or more above the mean 734 a for users having a loyalty level of −1 (step 824 ), then a vocality score of “Vocal” is assigned to the user (step 826 ); (3) otherwise, a vocality score of “Non-Vocal” is assigned to the user (step 828 ).
[0065] If the user's loyalty level is 3 (step 830 ), then: (1) if the user's best word count 708 a is one standard deviation 728 b or more above the mean 728 a for users having a loyalty level of 3 (step 832 ), then a vocality score of “Vocal Advocate” is assigned to the user (step 834 ); (2) otherwise, if the user's net word count 708 d is one standard deviation 734 b or more above the mean 734 a for users having a loyalty level of 3 (step 836 ), then a vocality score of “Vocal” is assigned to the user (step 838 ); (3) otherwise, a score of “Non-Vocal” is assigned to the user (step 840 ).
[0066] If the user's loyalty level is 1 or 2 (step 842 ), then: (1) if the user's net word count 708 d is one standard deviation 738 b or more above the mean 738 a for all users (step 844 ), then a vocality score of “Vocal” is assigned to the user (step 846 ); (2) otherwise, a vocality score of “Non-Vocal” is assigned to the user (step 848 ).
[0067] Once the users' vocality scores 712 have been identified, a vocality rendering engine 742 may produce output 744 which represents the vocality scores 712 in any of a variety of ways (step 850 ). For example, when the profile for a particular user is displayed, the profile may display information such as the user's name, title, email address, and loyalty level. The display may also include an icon, such as a megaphone, which graphically represents the user's vocality score. For example, the bullhorn may have zero or more lines emanating from it, where the number, shape, and/or size of the lines corresponds to the user's vocality score. For example, a “Non-Vocal” user's megaphone may have no lines emanating from it ( FIG. 9A ), a “Vocal” user's megaphone may have several lines emanating from it ( FIG. 9B ), a “Vocal Advocate” user's megaphone may have lines with plus signs emanating from it ( FIG. 9C ), and a “Vocal Detractor” user's megaphone may have lines with minus signs emanating from it ( FIG. 9D ). Clicking on the megaphone may cause the system 700 to display the user's textual input 704 , or other data created by the user which resulted in the user's vocality score.
[0068] The techniques described above with respect to FIGS. 7 and 8 A- 8 C are merely one example of how vocality may be measured, and do not constitute a limitation of the present invention. For example, the distinction in FIGS. 7 and 8 A- 8 C between “Detractors” and “Advocates” may be ignored when measuring users' vocality, so that users are merely labeled “Vocal” or “Non-Vocal” depending on the numbers of words in their input. Such a technique may be applied in FIG. 8B , for example, by labeling users as “Vocal” in step 822 (instead of “Vocal Detractors”) and in step 834 (instead of “Vocal Advocates”).
[0069] Furthermore, although in the example just described, users are classified either as “Vocal” or “Non-Vocal,” users' degrees of vocality may be divided into more than two categories. Rather, any number of values of any kind may be used to represent users' degrees of vocality.
[0070] Furthermore, in the example illustrated in FIGS. 7 and 8 A- 8 C, any given user is classified as “Vocal” or “Non-Vocal” based on the number of words in that user's input relative to the numbers of words used by other users in their input. Although using statistical measures of the numbers of words used by a population of users to draw the dividing line between “Vocal” and “Non-Vocal” users may be useful, it is not a requirement of the present invention. Rather, breakpoints between “Vocal” and “Non-Vocal” users (and between any other values used to represent vocality) may be absolute values, chosen in any manner, rather than values chosen relative to the input of a population of users. More generally, such breakpoints may be chosen in any manner and may change over time.
[0071] As yet another example of how vocality may be measured, consider an embodiment of the present invention which uses three vocality values, referred to herein as “Non-Vocal,” “Vocal Advocate,” and “Vocal Detractor.” In this embodiment, whether a particular user is Vocal (whether Advocate or Detractor) rather than Non-Vocal may be determined in the manner described above with respect to FIGS. 7 and 8 A- 8 B, namely by determining whether the number of words used by the user is more than one standard of deviation greater than the mean for users having the same loyalty level. In this embodiment, however, whether the user is considered an Advocate or a Detractor is based not on the user's loyalty level, but rather on the ratio of the user's “best” word count to the user's “worst” word count.
[0072] More specifically, once the user's loyalty level is known ( FIG. 8A , step 815 ), then the method shown in FIG. 8C may be used to compute the user's vocality score. If the user's net word count 708 d is one standard deviation 734 b or more above the mean 734 a for users having the same loyalty level (step 862 ), then a vocality score of “Vocal” is assigned to the user (step 864 ). Otherwise, the user is assigned a vocality score of “Non-Vocal” (step 866 ).
[0073] If the user is labeled as Vocal (step 864 ), then the method computes the ratio of the user's best word count 708 a to the user's worst word count 708 b (step 868 ). The method may add a nominal value, such as 0.1, to the user's worst word count in step 868 to avoid division by zero. The method then determines whether the ratio is greater than some predetermined threshold, such as 0.66 (step 870 ). If the ratio exceeds the threshold, the user is assigned a vocality score of “Vocal Advocate” (step 872 ). Otherwise, the user is assigned a vocality score of “Vocal Detractor” (step 874 ).
[0074] Note that the method of FIG. 8C may result in users with low (e.g., −1) loyalty levels being labeled as Vocal Advocates, and users with high (e.g., 3) loyalty levels being labeled as Vocal Detractors. This is surprising, since one would expect users with low loyalty levels to be detractors and users with high loyalty levels to be advocates. Special attention should be paid to Advocates with low loyalty levels and Detractors with high loyalty levels, because by focusing on these customers, both the Loyalty and Vocality of the customer base can be increased. Alternatively, the loyalty levels of conflicted respondents may be modified so that their loyalty levels match their status as Advocates or Detractors, as indicated by their vocality. More specifically, if a user's vocality indicates that he or she is an Advocate, then the user's loyalty level may be incremented or changed to the maximum loyalty level. Conversely, if the user's vocality indicates that he or she is a Detractor, then the user's loyalty level may be decremented or changed to the minimum loyalty level.
[0075] The techniques described above are examples of ways in which the emotivity and/or vocality of text may be measured. Although it may be useful to measure the emotivity and/or vocality of a particular text written by a particular user, it may also be useful to measure the emotivity and/or vocality of: (1) a particular user over time, and/or (2) a collection of users over time. Such measurements may be used to identify trends in emotivity and/or vocality, and thereby to identify trends in loyalty, over time.
[0076] For example, referring to FIG. 10 , a flowchart is shown of a method 1000 performed in one embodiment of the present invention to identify trends in loyalty of a single user over time. The method 1000 receives text input from one or more users (step 1002 ). The method 1000 then identifies a vocality score (step 1004 a ) and/or an emotivity score (step 1004 b ) for each of the users, based on the received text input. The vocality scores may, for example, be identified in the manner disclosed herein in connection with FIGS. 7 and 8 A- 8 C, or in any other way. Similarly, the emotivity scores may, for example, be identified in the manner disclosed herein in connection with FIGS. 5-6 , or in any other manner.
[0077] Note that the method 1000 may generate only vocality scores, only emotivity scores, or both vocality scores and emotivity scores for each of the users. Furthermore, the emotivity scores are merely one example of measurements that may be generated using latent semantic analysis. Therefore, other forms of latent semantic analysis may be applied to the input text to produce measurements other than emotivity scores.
[0078] The method 1000 may then identify one or more measurements of velocity in: the vocality scores (step 1006 a ), the latent semantic analysis (e.g., emotivity) scores (step 1006 b ), and the combination of the vocality and latent semantic analysis scores (step 1006 c ). In general, the “velocity” of a set of scores over time refers to the rate of change of the scores over time. Such velocity may be measured, for example, using any known techniques for measuring velocity, where the series of scores is treated as a series of positions, each of which is associated with a particular time. For example, if a first score S 1 occurs at time T 1 , and a second score S 2 occurs at time T 2 , the velocity V for this pair of scores may be computed as (S 2 −S 1 )/(T 2 −T 1 ).
[0079] The “time” values associated with scores may be identified in any of a variety of ways. For example, the time value of a particular score may be equal to or derived from the creation time of the user input (e.g., survey answers) from which the score was produced. As another example, each input (e.g., set of survey responses) received from a particular user with respect to a particular relationship partner of that user may be assigned sequential “time” values, e.g., 1, 2, 3, 4, independent of the chronological times at which those inputs were created or received.
[0080] Velocity may, however, be computed in other ways. For example, in some situations one may only be interested in whether a velocity is non-zero. In such a case, any non-zero velocity may be converted to a normalized value, such as 1. As another example, in some situations one may only be interested in whether a velocity is negative, zero, or positive. In such a case, negative velocities may be converted to a normalized value such as −1, zero velocities may remain zero, and positive velocities may be converted to a normalized value such as 1. These are merely examples of ways in which velocities may be computed.
[0081] Furthermore, any derivative of velocity, such as acceleration, may be computed based on the vocality/semantic analysis scores, and/or directly based on velocity or other derivatives of velocity. Therefore, any discussion of “velocity” herein should be understood to refer not only to velocity but also to acceleration and other derivates of velocity.
[0082] The method 1000 may, for example, identify for each user any one or more of the following: (1) a vocality velocity measurement based on the set of vocality scores for that user over time; (2) a latent semantic analysis velocity measurement based on the set of latent semantic analysis (e.g., emotivity) scores for that user over time; and (3) a combined velocity measurement based on both the vocality measurements and the latent semantic analysis measurements for that user over time. The combined velocity measurement may be calculated in any way, such as an average or weighted sum of the user's vocality velocity measurement and latent semantic analysis velocity measurement.
[0083] As another example, each of the user's vocality and latent semantic analysis measurements for a particular text may be combined together to produce a combined content measurement. The user's combined velocity measurement may then be calculated as the velocity of the user's combined content measurements.
[0084] The velocity measurement(s) associated with a particular user may be used for a variety of purposes. For example, a company or other relationship partner may be interested in knowing the velocities of the company's customers, so that the company may identify customers in need of attention.
[0085] For example, referring again to FIG. 10 , the method 1000 may enter a loop over all user's U (step 1008 ). Assume for purposes of the following example that user U is a company. The method 1000 then enters a loop over each partner P of user U (step 1010 ). Assume for purposes of the following example that the partners P are customers of company U.
[0086] The method 1000 identifies a velocity of customer P with respect to company U (step 1012 ). The velocity identified in step 1012 may, for example, be any of the velocities described above with respect to steps 1006 a - c.
[0087] If the velocity identified in step 1012 exceeds a predetermined threshold (step 1014 ), the method 1000 notifies company U of customer P's velocity (step 1016 ). Note that the threshold may be applied to the absolute value of the velocity, so that the company is notified of both large positive and large negative velocities. Furthermore, a function other than a simple threshold may be applied to the velocity to determine whether to notify the company of the velocity.
[0088] Alternatively, for example, the method 1000 may notify company U of the velocity of all customers, not just those customers whose velocities exceed a predetermined value. Furthermore, the notification performed in step 1016 may take any form. For example, it may include the value of customer P's velocity, or simply be a warning to company U that customer P requires attention.
[0089] Furthermore, the method 1000 may take into account the value of customer P's velocity when deciding which kind of notification to provide and/or which kind of action to take. For example, a customer whose vocality has a very high velocity may require more immediate attention than a customer with a lower velocity. The method 1000 may take this into account by prioritizing the customers P according to their velocities or functions thereof. For example, the method 1000 may instruct company U to attend to customer P within an amount of time that is derived from customer P's velocity, where larger velocities result in shorter amounts of time.
[0090] The method 1000 may repeat the process described above for the remaining customers of company U (step 1018 ) and for other companies (step 1020 ).
[0091] The techniques disclosed herein for measuring emotivity and vocality have a variety of advantages. For example, purely quantitative survey responses—such as “Rate your business partner on responsiveness on a scale of 1 through 5”—provide only limited information about the “loyalty climate” that characterizes the relationship between the survey respondent and the subject of the survey. A customer who responds with a value of 5 (highly satisfied) may still have little or no emotional attachment to his business partner. In fact, a respondent who responds with a value of 4 may feel more strongly about the business partner than someone who responds with a value of 5, yet such purely numerical responses fail to capture such subtle but important differences in loyalty climate.
[0092] The techniques disclosed herein can fill this gap in understanding by providing meaningful quantitative measures of respondents' feelings about their relationship partners, in the form of emotivity and vocality measurements. These measurements may be based on free text input provided by the respondents, and may therefore capture information which would otherwise go unrecognized solely by analyzing the respondents' numerical survey answers.
[0093] Although emotivity and vocality both measure intensity of feeling in some sense, they provide such measures in different ways that complement each other. Emotivity is based on semantic analysis of the words used by respondents, and therefore can capture very strong feelings expressed even in very few words. Vocality is based on the number of words used by respondents, and therefore can recognize strong feelings in respondents' responsive even when the individual words used by the respondents do not clearly indicate such feelings. Vocality is particularly useful as a complement to emotivity in light of the difficulty of performing semantic analysis of natural languages both automatically and accurately.
[0094] Identifying how strongly one partner to a relationship feels about the other partner is important because identification of such strength of feeling can be used as part of an overall process of identifying the loyalty of the first partner to the second partner. For example, the above-referenced patent application entitled, “Loyalty Measurement” discloses a system for calculating a loyalty index for a user based on a plurality of loyalty dimensions. Emotivity and vocality may be added as additional dimensions within such a system. Once emotivity scores are calculated for a population of users, the emotivity scores may be normalized to fit within the same range as scores in the other dimensions. The emotivity scores may then be weighted by a regression coefficient in the same manner as the other dimensions. Vocality may be integrated within the system in the same manner. Use of emotivity and/or vocality in this way may provide all of the benefits described in the “Loyalty Measurement” patent application.
[0095] One potential drawback of attempting to identify a person's strength of feeling, whether measured in terms of emotivity or vocality, based on textual input is that providing such textual input can be time-consuming. As a result, it may be difficult to obtain cooperation from users in providing such input. One advantage of embodiments of the present invention in this respect is that the textual input that is used to identify a user's emotivity and vocality scores may take the form of email messages, word processing documents, web pages, blogs, text messages, comment forms, transcribed phone conversations (such as customer service calls) and voicemail messages, and other text that the user has already written for other purposes. In other words, a user's emotivity and vocality scores may be calculated without requiring the user to write any additional text specifically for use in the emotivity and vocality measurements. The ability to calculate a user's emotivity and vocality scores based on existing documents also expands the amount of textual input that may be used to calculate such scores and thereby increases the accuracy of those scores.
[0096] Another benefit of certain embodiments of the present invention is that the “Emo list” 122 a , which includes words representing strong emotions, is not selected arbitrarily or by reference to any predetermined source of words (such as a dictionary or thesaurus), but rather is selected by identifying words used by users having very high and very low loyalty levels. As a result, the Emo list may contain words which reflect strong emotions, but which may not have dictionary definitions representing strong emotions, or which would not otherwise have been identified as “strong emotion” words. Since a word will be included on the Emo list if that word is used by high-loyalty and low-loyalty users, but not by middle-loyalty users, the Emo list is likely to include the words used by passionate users within a particular community. As a result, calculating each user's emotivity score based at least in part on the contents of the Emo list enables the emotivity score to reflect more accurately how emotive each user is in relation to other members of the community, not just in relation to predetermined (and possibly incorrect) notions of which words reflect strong emotions.
[0097] At the same time, the use of both the Emo list—which is generated based on words used within the community—and the positive and negative lists—which are generated based on dictionary definitions of words—ensures that the emotivity score is not unduly influenced either by unusual usages of words within the community or by predetermined notions of which words reflect strong emotions. Furthermore, the relative influence of the words in the Emo list 122 a , positive list 122 b , and negative list 122 c need not be determined arbitrarily. Rather, the techniques disclosed above with respect to FIGS. 1 and 2 may be used to assign weights A, B, and C in Equation 1 based on input provided by users 106 . In this way, the weights A, B, and C may be chosen to reflect the actual relationship between strong-emotion words, positive-emotion words, and negative-emotion words, respectively, on loyalty. For example, based on one set of data we have identified the values of 10, 1, and −15 for coefficients A, B, and C, respectively, reflecting the strong relationship between the use of negative words on loyalty. Calibrating the emotivity coefficients based on statistical analysis of empirical data in this way enables the emotivity scores generated by embodiments of the present invention to more accurately reflect users' emotivity.
[0098] Another benefit of certain embodiments of the present invention is that they may be used to identify the velocity of user's vocalities. It may be useful to identify such velocities because the raw vocality of a user, while helpful, may provide limited information about the user. For example, if a particular user's baseline vocality is relatively high and then begins to drop over time to lower and lower values, this downward trend may be evidence that the user's loyalty is decreasing, or that the user is otherwise in need of attention. The user's new, lower, vocality scores, however, may still be relatively high compared to the vocality scores of other users or compared to some other baseline value. Merely analyzing individual vocality scores of the user, therefore, may fail to indicate that the user is in need of attention. In contrast, analyzing a sequence of the user's vocality scores over time and identifying the velocity of such scores may enable the system to draw conclusions and take actions, regardless of the absolute values of such scores.
[0099] It is to be understood that although the invention has been described above in terms of particular embodiments, the foregoing embodiments are provided as illustrative only, and do not limit or define the scope of the invention. Various other embodiments, including but not limited to the following, are also within the scope of the claims. For example, elements and components described herein may be further divided into additional components or joined together to form fewer components for performing the same functions.
[0100] Although in certain embodiments disclosed herein, both emotivity and vocality are represented as single numbers (such as the emotivity score 512 n FIG. 5 and the vocality score 712 in FIG. 7 ), this is not a limitation of the present invention. Rather, emotivity and vocality may be represented in other ways, such as by multiple values.
[0101] Although particular techniques are disclosed herein for generating the Emo list 122 a , positive list 122 b , and negative list 122 c , such lists may be generated in other ways. Furthermore, such lists 122 a - c may be updated over time. For example, the Emo list 122 a may be updated as additional free-text responses are received from users who loyalty levels are already known. For example, if text is received from a person having a loyalty level of −1 or 3, then any words used by that person may be added to the Emo list 122 a , so long as those words are not in the “non-emotive” list 320 b . As another example, the system 100 may scan emails within a corporation and continuously update the Emo list 122 a based on words within emails sent by senders whose loyalty levels are already known.
[0102] Although in the example illustrated in FIGS. 7 and 8 A- 8 C, the statistics 720 a - 720 e are means and standard deviations, other statistics may be used in the process of measuring vocality. For example, other kinds of averages, such as modes or medians, may be used. Furthermore, in FIGS. 8A-8C , a single standard deviation serves as the breakpoint between different vocality levels. This is merely one example, however, and does not constitute a limitation of the present invention. Any breakpoint(s) between different vocality levels may be used.
[0103] The techniques described above may be implemented, for example, in hardware, software tangibly embodied in a computer-readable medium, firmware, or any combination thereof. The techniques described above may be implemented in one or more computer programs executing on a programmable computer including a processor, a storage medium readable by the processor (including, for example, volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. Program code may be applied to input entered using the input device to perform the functions described and to generate output. The output may be provided to one or more output devices.
[0104] Each computer program within the scope of the claims below may be implemented in any programming language, such as assembly language, machine language, a high-level procedural programming language, or an object-oriented programming language. The programming language may, for example, be a compiled or interpreted programming language.
[0105] Each such computer program may be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a computer processor. Method steps of the invention may be performed by a computer processor executing a program tangibly embodied on a computer-readable medium to perform functions of the invention by operating on input and generating output. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, the processor receives instructions and data from a read-only memory and/or a random access memory. Storage devices suitable for tangibly embodying computer program instructions include, for example, all forms of non-volatile memory, such as semiconductor memory devices, including EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROMs. Any of the foregoing may be supplemented by, or incorporated in, specially-designed ASICs (application-specific integrated circuits) or FPGAs (Field-Programmable Gate Arrays). A computer can generally also receive programs and data from a storage medium such as an internal disk (not shown) or a removable disk. These elements will also be found in a conventional desktop or workstation computer as well as other computers suitable for executing computer programs implementing the methods described herein, which may be used in conjunction with any digital print engine or marking engine, display monitor, or other raster output device capable of producing color or gray scale pixels on paper, film, display screen, or other output medium.
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One embodiment of the present invention is directed to a computer-implemented system that analyzes free-form text comments provided by a user (such as a customer of a company) and draws conclusions about the tone of the user's feedback, such as whether the user's feedback is positive, negative, angry, critical, or congratulatory. Such conclusions may be reflected in a single numerical value referred to herein as “emotivity.” A customer's emotivity score may be used for various purposes, such as determining whether the customer is likely to provide a positive testimonial for the company, or whether a follow-up phone call should be made to the customer to improve the company's relationship with the customer. Furthermore, a measurement of the customer's loyalty to the company may be modified based on the user's measured emotivity.
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TECHNICAL FIELD
The present invention relates to dispensing cartons and, more particularly, to a carton for containing materials requiring barrier protection wherein the carton is formed from a single piece blank and includes an easily openable and recloseable pouring spout.
BACKGROUND ART
Foldable, erectable paperboard cartons or containers have long been recognized as an inexpensive and efficient way to contain many materials for many purposes. Over the years, cartons have been provided with specific features depending on the use of the carton, both in terms of the material to be contained therein and in terms of handling the carton itself.
One area of prior work has been the development of cartons and material for forming cartons for containing hygroscopic material or other materials requiring a high degree of barrier, such as various soap powders, sweeteners or pancake mixes. This type of container is particularly adapted to prevent the absorption of moisture by the material contained in the carton and also to prevent leakage of the material, by having, for example, double thickness walls or films or other coatings applied to or integrated with the carton walls. Leakage can be a particular problem, because the materials are typically in powder or fine granulated form and as such, easily penetrate unsealed seams or perforated lines provided on the carton having cuts that penetrate completely through carton walls.
There have been attempts in the prior art to provide a container that addresses the above concerns. U.S. Pat. No. 4,732,315 discloses a recloseable dispensing package that has a plastic fitment mounted over a cutout area in one flap and an overlying closure flap. Another structure for forming a recloseable opening in a carton for containing a hygroscopic material is present in U.S. Pat. No. 4,718,557, wherein an outside panel may be opened to expose a weakened region that may be partially or fully severed from an inside panel. Also representative of the prior art is U.S. Pat. No. 1,303,138, which discloses a carton with a hinged flap that overlies pouring perforations in an inner flap.
U.S. Pat. No. 3,346,165 discloses an easy opening recloseable container including a dispenser for dispensing the contents. In particular, a portion of the container, severable along perforated lines to form a hinged flap, overlies an opening.
U.S. Pat. No. 2,819,832 discloses a leakproof carton having superimposed inside and outside spout openings. However, one problem unaddressed by this patent, as with other prior art cartons providing protection for material contained therein, is that a consumer has difficulty opening the carton because of the double, reinforced flap structures and the need to remove perforated material from two openings. Moreover, when double perforated flap structures are used, the material contained in the carton may still leak out and moisture may easily penetrate the carton, leading to contaminated contents, when the perforations are through cuts and cuts in separate layers are adjacent or superimposed. Thus, such prior art structures lack desired barrier qualities.
A carton having a double panel end closure with an opening flap in the outer panel providing access to a dispensing aperture in an inner panel is shown in U.S. Pat. No. 4,909,395. The opening structure includes a partially pre-cut bridge in the adhesive area for securing the outer flap to the inner panel. One problem with opening features of the type shown in the '165 and '395 patents is that coating materials or adhesives used between inner and outer panels may penetrate the perforations or scores or be inaccurately applied, thereby interfering with opening the carton. Also, cuts that run from the carton exterior to the inner opening can provide a path for moisture entry.
The use of paired, partial cuts, with one cut partially penetrating the package material from the inside and the other cut partially penetrating from the outside, is known as a means for forming frangible opening structures that have barrier qualities until torn. U.S. Pat. No. 4,809,853, discloses a package for containing dry, frangible products with a reclosable pouring opening. The opening/closure flap is defined by such paired, partial cuts into the material from which the carton is made. U.S. Pat. Nos. 4,886,170 and 4,919,785 disclose other cartons (not made to dispense materials by pouring) that include tear lines defined by cuts that partially penetrate the inner and outer surfaces of a top panel to define a delaminating tear area therebetween.
Despite the above-cited prior art, there remains a need for a carton for packaging powdered materials that prevents leakage and provides barrier protection for the material contained in the carton, while at the same time providing a pour spout that is easy for a consumer to open.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an opening structure for a carton containing products requiring a high degree of barrier protection from moisture and other contaminants, yet which enables a consumer to have easy access to the product and to reclose the carton after the initial opening.
The carton incorporating the inventive opening structure is generally tubular, having a material receiving central cavity formed by side and end walls. One set of end walls has an inner end wall panel having a spout hole opening precut into that panel and also includes an overlying outer end wall panel having a plurality of superficial, parallel, partial cut lines in the inside and outside surfaces thereof. The cut lines define tear areas for a cover flap having a leader portion so the consumer may easily grasp the cover flap to pull the flap away from the inner end panel with the hole, thereby exposing the hole so that the material may be dispensed therethrough. After use, the leader portion of the cover flap conveniently and securely may be used to lock the cover flap over the spout hole. The invention also encompasses a flat, die cut blank for forming into the package.
An object of the present invention is to provide a package, and a blank for forming the package, whereby materials susceptible to contamination may be contained therein with little danger of becoming contaminated, yet a purchaser can easily manipulate the package opening structure to dispense the contents and conveniently and easily reclose the package.
Other objects of the present invention are: to provide an easily openable container for powdered materials that avoids perforated score lines where leakage of the material might occur; to provide a package wherein complicated, difficult to manipulate, expensive films or inserts for closing the container or sealing the opening in the container to maintain product integrity are not required; to provide a two-layer wall panel structure containing a tearable opening structure; and to provide a container that does not require multiple steps for opening.
Important advantages of the present invention are that it combines specific shipping and packaging advantages, such as reduced contamination and leakage of material contained therein, with specific point of use advantages, such as enhanced ease of opening and closing.
Other objects and advantages of the present invention will become more fully apparent and understood with reference to the following specification and to the appended drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the outside surface of the blank from which the carton of the present invention is formed and shows the die cut profile thereof.
FIG. 2 is a top plan view of the inside surface of the blank from which the carton of the present invention is formed and shows the die cut profile thereof.
FIG. 3 is a perspective view depicting partial erection of the carton.
FIG. 4 is a perspective view of an erected carton showing the spoutbearing end just before final closure and showing how the bottom end portion of the carton is configured after the carton is filled.
FIG. 5 is a fragmentary perspective view of the spout bearing end of a fully erected and filled carton.
FIG. 6 is a fragmentary perspective view of the present invention partially opened.
FIG. 7 is a fragmentary perspective view of the present invention as it might appear after being fully opened by a consumer.
FIG. 8 is a fragmentary perspective view of the spout-bearing end of the present invention as it may appear following the reclosing of the spout.
FIG. 9 is a fragmentary perspective view of the spout-bearing end of the present invention showing an alternative location of the cuts forming the cover flap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 depicts the outside surface of a blank 10 for forming, in accordance with the present invention, a carton 11 as depicted in FIGS. 3 and 4. The carton 11 comprises a generally tubular body defining a cavity therein, the body being formed by opposed, parallel front and rear panels 16, 18; opposed, parallel side panels 20, 22; and top and bottom end-closure walls, each made from a set of cooperating overlapping end panels.
The blank is formed by die cutting and scoring paperboard or other similar sheet material. In the drawings, the double lines indicate fold score lines, usually provided to foldably interconnect various panels. Single, unbroken lines depict cuts that extend through or partially through the panels or depict free edges of the panels. Single, broken lines depict perforated score lines.
As best seen in FIG. 1, the side panels 20, 22 and front and rear panels 16, 18 are joined at parallel main body fold lines. A glue flap 24 is provided at a further parallel main body fold line along one edge of front panel 16 to secure the carton 11 in its generally tubular erected configuration.
Major bottom end panels 26, 28 and minor bottom end panels 30, 32 are joined to the lower edges of panels 16, 20, 18 and 22 as shown in FIG. 1. Major top end panels 34 (inner panel), 36 (outer panel) and minor top end panels 38, 40 are joined to the upper edges of panels 16, 20, 18 and 22 as shown in FIG. 1. The fold lines joining bottom end panels 26, 30, 28, 32 to panels 16, 20, 18 and 22 are parallel to the main body fold lines joining top end panels 34, 38, 36 and 40 and perpendicular to the fold lines joining panels 16, 20, 18 and 22. It should be appreciated that, as depicted in FIGS. 1 and 2, the major top end panels 36, 34 have free outside edges 37, 35, respectively, opposite and parallel to the fold lines attaching these panels to panels 18, 16, respectively. Major top end panels 34, 36 also have free front edges 33, 39, respectively.
The major top inner panel 34 is provided with a spout hole or opening 42. The spout hole 42 is generally centered on the central longitudinal axis A of the panel 34 (see FIG. 1) and closer to one end of the panel 34 than the other. The spout hole 42 has a rear edge 44, a front edge 46 opposite the rear edge, and opposed side edges 48. As best seen in FIG. 1, between the front edge 33 of the panel 34 and the front edge 46 of the hole 42, the outside surface of panel 34 has a plurality of transverse parallel, superficial incisions 50. The incisions penetrate 30% to 60% of the panel thickness and form a lead delamination area 51 lying between front edges 33 and 46 and comprising a plurality of delamination ribs 55 between the incisions 50. The side edges 48 of the spout hole 42 taper or angle inwardly toward one another near the front edge 46 of the hole 42 and the delamination area 51, thereby forming opposed support corners 53. It should be noted that the cut line 47 at front edge 46 extends for a short distance into each of the tapered areas near the front edge 46, so that the length of the cut line 47 at the front edge 46 is approximately equal to the width of the hole 42 away from the tapered area.
Further reference to FIG. 1 indicates that the major top outer end panel 36 includes a first transverse fold score line 54. The line 54 extends substantially across the surface of panel 36 perpendicular to edge 37. A cover flap 56 is provided between the front edge 39 of panel 36 and the first transverse fold score line 54. The cover flap 56 has a leader tab 68 at front edge 39 separated from the remainder of the cover flap 56 by a second transverse fold score line 66. The longitudinal edges of cover flap 56 (edges perpendicular to first and second transverse fold score lines 54, 66) are defined by two parallel tear areas 58 extending approximately from the second transverse fold line 66 to the first transverse fold line 54.
As seen in FIG. 1, the outer boundary of tear area 58 on one side of the cover flap 56 is formed primarily by the outside free edge 37 and the outer boundary of tear area 58 on the other side is formed by a cut line 59. The cut line 59 is a cut that partially (30% to 60%) penetrates the blank 10 along the fold line connecting the panel 36 to the side panel 18. A tapering of the tear areas 58 is created where a pair of cut lines 64, also partially penetrating the blank 10, angle or converge toward one another, one line 64 extending from the free edge 37 and the other from cut line 59. Between the tips of the tapered portions of tear areas 58 on the cover flap 56, the second transverse fold score line 66 is located.
As noted previously, the second fold score line 66 defines one boundary of a leader tab 68. Two parallel side edges of the leader tab 68 are defined by parallel, perforated tear lines 70 that extend at right angles from the second fold score line 66 in the direction of front edge 39. At the front edge 39 the leader tab 68 extends outwardly beyond what would otherwise be a straight front edge of panel 36, thereby forming a finger edge or lifting extension 72. (Alternatively, finger edge/lifting extension 72 can be formed by making front edge 39 straight and recessing front edge 33 slightly, so that when the carton 11 is erected as in FIG. 4, the front edge 39 extends out over edge 33.)
FIG. 2 depicts a plan view of the inside surface of the blank 10 and has reference characters in common with FIG. 1. FIG. 2 also presents additional details regarding the major top end panels 34, 36. Specifically, glue areas 76 are indicated at both the front edge 33 and the opposed rear edge 43 of major top inner end panel 34. The major top outer end panel 36 has glue area 78, which, in the preferred embodiment, extends substantially continuously around the panel 36 just inside the perimeter thereof.
The inside surface of the major top outer end panel 36 is provided with a pair of parallel, partial (30% to 60% of panel thickness) cuts or incisions 80. The cuts 80 define on the inside surface of the panel 36 the inner boundaries of the tear areas 58 on either side of the cover flap 56. The area 82 within these inner boundaries has substantially the same width as the spout hole 42 in the major top inner end panel 34. The partial cut lines or incisions 80, 80 extend from the first transverse score line 54 toward the front edge 39 (where that edge forms the finger edge or lifting extension 72), stopping at the second transverse fold line 66 near where lines 64 converge at the same score line 66; the lines/incisions 80, 80 also lie inside and spaced from the free edge 37 and cut line 59 of the major top outer end panel 36. Each line/incision 80 is substantially collinear with one of the perforated tear lines 70 defining the side edges of leader tab 68.
While FIGS. 1 and 2 show a preferred configuration, if a different size dispensing opening for a carton is desired, the size of the spout hole 42 may be reduced or enlarged. Partial cuts/incisions 80, 80 in the inside of panel 36 and the partial cuts 59, 64, 64 on the outside of the panel 36 may be moved inwardly toward or outwardly away from one another to correlate to the width of the hole 42.
FIGS. 3, 4 and 5 are commonly numbered with FIGS. 1 and 2 and depict the carton 11 of the present invention in various stages of erection. Specifically, in FIG. 3, the carton 11 has been formed into its generally tubular erected shape and the glue flap 24 has been glued to the inside of side panel 22. The minor top end panels 38, 40 have been folded inwardly and glue is applied to glue areas 76, 76, 78 on the panels 34, 36. (In this condition it can be seen that the length of minor top end panel 38 is such that it extends under the delamination area 51 but will reach no further than front edge 46.) In FIG. 4, the major top inner end panel 34 has been folded inwardly and the major top outer end panel 36 is ready to be folded inwardly and downwardly (as indicated by arrow B) to overlie the major top inner end panel 34, whereby the cover flap 56 and, specifically, the area 82 between tear areas 58 is brought into alignment with the spout hole 42. The carton 11 may be filled from the open top end depicted in FIG. 3 before inward folding of panels 34, 36. If this is done, the major bottom end panels 26, 28 will have been folded inwardly onto the previously inwardly folded minor bottom end panels 30, 32, with all panels secured in place by suitable glue or adhesive. Alternatively, the carton 11 may be filled from the open bottom end (as depicted in FIG. 3) if the top end is closed and sealed first.
FIG. 5 shows a detailed view of the opening structure of the present invention when panel 36 has been affixed on top of panel 34. As can be seen, the cover flap 56, including leader tab 68, extends from finger edge or lifting extension 72, which extends outward from side panel 20, back to first transverse fold score line 54. Spout hole 42 is covered and sealed, in that it is surrounded by adhesive 78 and no through-cut path exists to provide access to hole 42. The through cuts in perforated tear lines 70, 70 lead only to the surface of delamination ribs 55 in the delamination area 51. The incisions 50 forming the ribs 55 are transverse, aligned approximately parallel to the adjacent lead edge 46 of the hole 42, and do not lead from finger edge 72 to the spout hole 42, nor do they extend through the panel 34 to the interior of the carton 11. In an alternative embodiment, the bead of adhesive running along the fold line 31 at the edge of the panel 36 opposite edge 37 is omitted. While this bead of adhesive helps "caulk" the edge 35 when the panel 36 is folded onto panel 34, where a lesser degree of barrier can be tolerated, the combination of a U-shaped glue bead and the carton material at the fold line 31 between the panels 18 and 36 is sufficient barrier.
FIGS. 6, 7 and 8 depict the carton 11 in various conditions during opening and use by a consumer. FIG. 6 illustrates how the finger edge 72 and leader tab 68, subjected to an upward force, indicated by line or arrow L, are used to begin a tearing or severing along perforated tear lines 70. At this point, the carton 11 is still sealed, because a portion of the glue area 78 still overlies the incisions 50; however, part of delamination ribs 55 of the major top inner end panel 34 has started to tear away, beginning delamination in the delamination area 51.
FIG. 7 depicts the effect of continued lifting force (in the direction of the arrow L) exerted by the user on leader tab 68. The delamination area 51 is now fully delaminated; all ribs 55 adjacent the front transverse score line 54 are removed and remain attached to the inner surface of leader tab 68 as a result of serial or sequential delamination of the ribs 55 between the transverse incisions 50. Along the pair of parallel tear areas 58,58 of cover flap 56, defined in part by the partial cuts 80 on the inside of the major top outer end panel 36, the continued lifting of the leader tab 68 results in parallel delamination regions adjacent and above the side edges 48 of the spout hole 42. Support corners 53 are uncovered. They provide a narrowing of the spout hole 42 whereby the flow of product 86 may be more easily directed by the consumer as pouring takes place. The first transverse fold score line 54 aids folding the cover flap 56 back upon the panel 36 so that it will not interfere with the dispensing of the product 86.
FIG. 8 depicts reclosure of the cover flap 56 following dispensing of product 86 by the consumer. Specifically, a special function of the leader tab 68 is shown. From the position shown in FIG. 7, for reclosure the leader tab 68 is folded and rotated downwardly along the second transverse fold score line 66 and directed into the full cut 47 extending along the front edge 46 of spout hole 42 between the support corners 53 at one edge of the delamination area 51. Continued force (in the direction of arrow M) rotates the cover flap 56 about the first transverse fold score line 54 until the surfaces separated by delamination in the tear areas 58 of panel 36 are back in contact with each other, thereby reclosing the container 11. It should be noted that the distance between the first and second transverse score fold lines 54, 66 is slightly greater than the distance between the second transverse score fold line 54 and the full cut 47 at edge 46. Accordingly, the leader tab 68 has to be inserted at an acute angle relative to the remainder of cover flap 56. Thus, upon insertion of the leader tab 68 for reclosure, a recess area 88 is formed just below the second transverse fold line 66, so that a user may easily insert a finger into the recess 88 to reopen the carton.
A number of variations of the present invention can be made. For example, the size of the spout hole 42 may be changed and the superficial or penetrating cuts on the inside and outside of the major top outer panel 36 and the outside of major top inner panel 34 may be adjusted accordingly so that any size dispensing spout may be provided. Thus, as depicted in the drawings, the fold score line connecting panel 36 to side panel 18 may incorporate the partially penetrating cut line 59, with free edge 37 forming the corresponding outer boundary of the tear area 58 of the other side of the cover flap 56. Alternatively, as seen in FIG. 9, the tear areas 58 of cover flap 56 may be located inwardly of the side edges of the panel 36 by moving cut line 59 inward to line 59' and placing a corresponding cut line 59" inboard of edge 37. While the position of the spout for the carton 11 has been depicted at or near one end of the top wall of rectangular carton 11, the spout might be located where convenient elsewhere on the same top end-closure wall, or on another wall having a closure structure using two overlapping panels or on a nonrectangular carton having a closure structure having two overlapping panels. While the spout hole 42 is shown as a generally rectangular hole, it is within the scope of the present invention that the spout hole 42 might be round or oblong or have another shape.
The material from which the present invention is fabricated may be of paperboard or any suitable stiff but still flexible sheet material and, in fact, the carton 11 may be formed from sheet plastics or other similar materials. Additionally, any paperboard used may be coated with various substances to impart desirable characteristics thereto such as greater resistance to liquids. The present invention is particularly advantageous in these coated paperboard situations, because manipulation of the cover flap 56 causes delamination in areas 51 and 58 to occur based on pre-cut lines. Thus, a user is not required to tear through coating material. For further sealing, the carton 11 may be overwrapped with any thermoplastic film or other suitable material. Both the interior and the exterior of the carton 11 may be marked with appropriate indicia and may be provided with other features to facilitate the handling, transportation and retailing of the carton and the product therein.
It should be understood that as an alternative to assembling the carton 11 as shown in FIG. 3, the producer of the carton may provide the carton 11 in blank 10 form, in a completely flat, unerected condition. Thus, the purchaser of the carton 11 of the present invention has the option of how to purchase; if the blank 10 is purchased in a flat condition, instructions may be provided about how to form the carton 11 for receiving contents.
Although the description of the preferred embodiment has been presented, it is contemplated that various changes, including those mentioned above, could be made without deviating from the spirit of the present invention. It is desired, therefore, that the present embodiment be considered in all respects as illustrative, not restrictive, and that reference be made to the appended claims rather than the foregoing description to indicate the scope of the invention.
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A carton for containing and protecting hygroscopic materials is provided and includes an integral pouring spout. The carton includes overlying end closure panels each having an array of partially penetrating cut lines on its inner and outer surfaces and cooperating perforations with through-cuts. A leader tab is provided on an outer end panel and an inner panel has a spout hole therein. The array of cut lines on the panels enables areas of delamination to be created, to lift a cover panel and expose the spout hole when the leader tab is pulled. The cover panel, the leader tab and a cut along the lead edge of the spout hole provide convenient reclosing of the carton. A flat blank for forming into the carton is also encompassed.
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BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for a machine which is to handle packs of newspapers, weekly journals and the like, hereinafter designated signatures, lying loosely one on top of the other, and particularly intended for loading such packs on a pallet in a predetermined pattern, tightly adjacent to and on top of each other.
Loading loose signature packs on a pallet has so far been done manually or with aid of complicated and expensive machines, and in the case of the latter the whole pallet has been moved into different positions as the packs have been deposited, until a desired number of pack layers or courses have been built up on the pallet. Since a loose pack of signatures is very difficult to handle during loading without the signatures being displaced relative to each other so that the sides of the pack become uneven, it is also common to bundle each pack in film, or to band the pack before loading it onto a pallet.
SUMMARY OF THE INVENTION
The present invention therefore is to provide an arrangement for a machine of the type mentioned in the introduction, by means of which positive deposition and course formation in the loading of signature packs on a pallet are ensured, and in which the drawbacks to be found with the machines and modes of procedure mentioned above are entirely eliminated. This is obtained with a machine of the kind in question which, in accordance with the invention, comprises an industrial robot known per se, with an arm which is swivelable, raisable and lowerable and which can carry out a reciprocating movement. The arm has at its free end a rotation unit on which a gripping means is mounted, the gripping means comprising a support plate with at least two carrying rods at a predetermined spacing apart. The rods are axially movable from an inner position to an outer position and vice versa. At least one pressure plate is disposed above the carrying rods, the pressure plate being vertically movable in a direction towards the rods and being adapted for pressing together and retaining the pack against the rods in their outer position, when moving a pack of signatures. The plate maintains its pressure against the upper side of the pack until the pack engages against the pallet or against a pack previously deposited thereon, when the pack is deposited to form part of the load on the pallet and after rapid withdrawal of the rods from the underside of the pack to their inner position.
By virtue of the invention there is now obtained a structure which admirably fulfils its objects, but which is simultaneously simple and cheap to manufacture. By means of the firm grip in which each signature pack is kept by the gripping means while being taken from a conveyor, e.g. a belt conveyor, for deposit on the pallet load being formed, the risk of mutual displacement of the newspapers is completely eliminated. At the instant of deposition itself, the relative mutual positions of the newspapers in the pack remain as desired, since the pressure plate accompanies and presses down the pack with a force exceeding that of gravity on the pack itself in the small drop occuring when the carrying rods are snatched back, whereby possible tipping or separation cannot occur. During removal of the gripping means, the pressure plate is pressed against the upper side of the pack until its piston rod has reached its furthermost extended position, at which the gripping means itself is moved upwards sufficiently far from the deposited pack so that there is no possibility of the pack catching when the gripping means swings away. The pressure plate then moves back to its completely retracted initial position. The air is pressed out of the signatures by the pressure plate pressing the pack against the carrying rods, friction between the signatures thus increased, which being further ensures that the pack remains intact during handling. As a result of the robot's programability, exact paths for the signature packs can be prescribed from picking up at the conveyor to deposition in the desired pattern on the load being built up on the pallet, without needing to move the pallet. Keeping the pallet stationary during palletization has been found to result in great economies in space and labor.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic side view of the arrangement and machine in accordance with the invention.
FIG. 2 illustrates on a larger scale a view from above of a preferred embodiment of the gripping means.
FIG. 3 illustrates on an enlarged scale another embodiment of the gripping means seen from one side.
FIG. 4 is a view of the gripping means illustrated in FIG. 2, seen from the side from which a signature pack is gripped.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As will be seen from FIG. 1, the arrangement and machine in accordance with the invention comprises an industrial robot or an automatic control and manipulation unit 1 with a portion 2 which is swivelably, as well as raisably and lowerably attached to the body 3 of the robot 1 via a shaft structure 4. An arm 5 is extendably and retractably mounted in the portion 2. The robot 1, of known construction, is programable by means of a commercially available programming unit and memory unit, neither of which is illustrated in the drawing, whereby desired movement can be programmed directly into the memory unit in conjunction with manual maneuvering of the robot arm 5. At its free end, the arm 5 is provided with a rotation unit 6, on which a gripping means 7 is mounted. The gripping means 7 comprises a support plate 8, which at its lower end is provided with at least two carrying rods 9, 10, arranged parallel and at a predetermined spacing from each other, and intended to carry a signature pack 11, which is conveyed by a conveyer 12 to within the reach of the arm 5 with gripping means 7. The conveying element of the conveyor 12 can comprise a plurality of bands within the area the packs 11 arrive at before the lifting operation, to enable the insertion of the carrying rods 9, 10 under the respective pack 11. The carrying rods 9,10 preferably comprise hardened and ground steel shafts, for obtaining the low friction required to maintain the sheet of paper nearest the rods in undamaged condition when the rods 9,10 are snatched away. The rods 9,10 are mounted by means of mountings 13, e.g. ball bushings, in the support plate 8. In FIGS. 1, 2 and 4 the carrying rods 9,10 consist of the piston rods to compressed air cylinders 14, 15, which are mutually parallel and are attached to the lower edge of the support plate 8 on the side thereof facing towards the rotation unit 6. In their retracted position, the ends of carrying rods 9,10 are somewhat inside or are flush with the surface of the support plate 8 against which a side surface of a signature pack 11 is intended to bear (the right hand surface in FIGS. 1-3). The other, extended position of the carrying rods 9, 10 is variable in response to the shape of the pack 11 to be lifted. To enable rapid withdrawal of the carrying rods 9, 10 in conjunction with deposition of a pack 11, the cylinders 14, 15 for operating rods 9,10 are provided with rapid bleed air valves 16.
In the embodiment illustrated in FIG. 3, the carrying rods 9, 10 are made with teeth 17 to form a rack on their undersides. The teeth 17 co-act with a driven shaft 18 between the rotation unit 6 and support plate 8 for displacing the rods 9, 10 between their retracted and extended positions.
A pressure plate 19 is disposed above the carrying rods 9, 10 and spaced from the upper portion of the support plate 8 for movement in a direction substantially at right angles to the carrying rods 9, 10. The pressure plate 19 is provided with a friction plate 20 so as not to glide on the upper side of the signature pack 11. Air in the pack 11 which is to be handled is removed with the aid of compression from the pressure plate 19, so that friction between the signatures increases. In the embodiment illustrated in FIGS. 1, 2 and 4, the pressure plate is actuated by a piston rod 21 associated with a vertically adjustable compressed air cylinder 22, fixed to the upper portion of the support plate 8, the spacing between the piston rod 21 and the support plate 8 being adjustable to suit the shape of the signature packs 11 which are to be handled. The spacing of the piston rod center from the support plate 8 should preferably be 2/5 of the pack dimension at right angles to the support plate 8. Apart from the piston rod 21, the pressure plate 19 is supported or guided by a guide rod 24, glidable in a guiding bush 23 co-acting with the support means of the cylinder 22.
As will be seen from FIG. 3, the pressure plate 19 can also be pivotably attached to a telescopic swinging arm 25, which is unrotatably attached to a rotation motor 26 at the upper portion of the support plate 8, for providing the compressive force against a signature pack 11.
After the robot has been programmed with the desired motion pattern, the pallet loading machine functions in the following way: The gripping means 7 swings into position in front of a signature pack 11 in the outmost position on the conveyor 12 such that the carrying rods 9, 10, which are in the extended position, come under the pack. The end portion of the conveyor 12 and its conveying element are formed to allow the rods 9, 10 to come into position under the pack 11. The gripping means 7 is taken in towards the pack 11 such that the support plate 8 bears against the face of the pack 11 presented to it. The robot arm 5 subsequently moves upwards simultaneously as the pressure plate 19 presses the signatures forming the pack 11 against the carrying rods 9, 10. The arm 5 now swings into its programmed position above the place on the pallet load being built up, whereafter it sinks to a level just above the deposition surface thereon. The carrying rods 9, 10 are snatched away very quickly, causing the pack to fall down simultaneously as the pressure plate 19 guides it in an exact path by pressing against the pack 11 with a force greater than the normal gravitational acceleration of the pack 11, thus preventing the pack from tipping or separating. By means of the long stroke of the compression plate 19, relatively large variations in the level of the surface on which the pack 11 is to be deposited can be accommodated. The arm 5 then goes upwards with its gripping means 7 and the pressure plate 19 first releases its pressure on the pack 11 when in its furthermost extended position, whereby knocking against the deposited pack 11 during the removal of the gripping means 7 does not disturb the pack 11. When the pack 11 has come into place on the pallet, both its upper and lower signatures thereof are completely undamaged. The pressure plate 19 is first withdrawn to its uppermost retracted position when the gripping means 7 has moved a safe distance from the already deposited signature packs 11. The arm 5 with gripping means 7 then returns to the conveyor 12 to collect the next pack 11, and this is repeated the number of times which has been programmed in the memory, e.g. until the pallet is loaded to the desired height. In the depositifng operation, the packs are turned so that the spines of the signatures therein conform to a programmed pattern, ensuring that the load on the pallet doesn't disintegrate. The signals for the functions of the pressure plate and carrying rods are also programmed into the memory, whereby the machine can load a pallet to capacity completely automatically without any manual work needing to be performed.
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According to the invention, a machine is disclosed for handling and preferably loading loose signature packs onto a pallet. In a preferred embodiment, the machine comprises an industrial robot known per se, which has an arm movable in all planes. This arm is provided with a rotation device on which is mounted a gripping device incuding at least two horizontal, reciprocally movable carrying rods co-acting with a support plate and at least one vertical pressure plate movable toward and away from the carrying rods for gripping and conveying a pack of loose signatures from a conveyor and depositing them in a programmed pattern for building a load on a pallet.
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BACKGROUND OF THE INVENTION
Halogen substituted((phenylamino)carbonyl)-benzamides are known in the art as, for example, in U.S. Pat. No. 3,748,356; U.S. Pat. No. 3,450,747, and Belgian Pat. No. 833,288.
DESCRIPTION OF THE INVENTION
The novel compounds of this invention are of the formula ##STR1## wherein each X substituent is individually chosen from the group consisting of H, Cl, F, Br, .[.CR 3 '.]. .Iadd.CR' 3 .Iaddend. and .[.OCR 3 '.]. .Iadd.OCR' 3 .Iaddend., wherein each R' substituent is individually, either R" or H, with R" being selected from the group consisting of F, Cl and Br, with the proviso that both X substituents are not H;
each A substituent is individually chosen from the group consisting of CH 3 and H, with the proviso that both A substituents are not CH 3 ;
Y represents S or O; and
R represents a halogenated alkyl group having up to 3 carbon atoms.
The term "active ingredients" is at times used hereinafter in this specification to broadly describe the compounds of the present invention.
The active ingredients of the present invention are normally crystalline solids which are of low solubility in water and of moderate solubility in many organic solvents. These active ingredients have low phytotoxicity to plants and have exceptional activity in the kill and control of such insects as the cabbage looper, beet army worm, and the larvae of mosquitoes, hornflies and houseflies. These active ingredients may be formulated with the usual insecticide carriers, well known to those skilled in the art, to provide insecticidal compositions.
The compounds of the present invention may be prepared via several methods hereinafter set forth. One common method is to react an appropriate benzoyl isocyanate derivative with an appropriate anisidine or phenetidine derivative in the presence of an organic solvent. The following reaction scheme illustrates this method of preparing the compounds of the present invention: ##STR2## wherein X, A, Y and R are as set forth above.
The reaction is carried out by contacting the reactants together in equimolar proportions in the presence of a solvent at a reaction temperature which, at atmospheric pressure, may vary from 0° C. to the boiling point of the solvent used. Examples of suitable solvents are aromatic hydrocarbons such as benzene or xylene, chlorinated hydrocarbons such as chloroform, methylene chloride or ethylene chloride or other inert solvents such as acetonitrile.
Following the completion of the reaction (generally lasting from about 0.5 to about 24 hours), the mixture is cooled and the precipitated product is collected by filtration or other suitable techniques. This product usually is washed with a solvent such as hexane and dried. The resulting crude product may be further purified, if desired, by recrystallization from a solvent such as aqueous acetic acid or by other purification procedures.
Compounds of the present invention may also be produced by:
Method B
Reacting a compound of the formula ##STR3## where X and A have the aforementioned meanings, with a compound of the formula ##STR4## where R and Y have the aforementioned meanings, preferably in equimolar proportions in a reaction mixture containing pyridine and sodium in a suitable solvent so as to obtain the corresponding compound of the present invention.
Method C
Reacting a compound of the formula ##STR5## where X has the aforementioned meaning, with a compound of the formula ##STR6## where A, Y, and R have the aforementioned meanings, in the presence of a solvent such as benzene or toluene and a base (such as triethylamine or 3,4-dichloroaniline) capable of binding the hydrogen chloride evolved so as to obtain an intermediate compound of the formula ##STR7## which is hydrolyzed such as by agitation in water so as to obtain the corresponding compound of the present invention.
Method D
Reacting a compound of the formula ##STR8## where R" is an alkyl group having from about 1 to about 4 carbon atoms and A and X have the aforementioned meanings, with a compound of the formula ##STR9## where R, Y and A have the aforementioned meanings, in the presence of an inert solvent such as xylene or chlorobenzene so as to obtain the corresponding compound of the present invention.
Method E
Reacting a compound of the formula ##STR10## where X, R" and A have the aforementioned meanings, with a compound of the formula ##STR11## where A, Y and R have the aforementioned meanings, in equimolar proportions in the presence of a solvent such as toluene so as to obtain the corresponding compound of the present invention.
DESCRIPTION OF SOME PREFERRED EMBODIMENTS
The following examples illustrate the present invention and the manner by which it can be practiced but as such should not be construed as limitations upon the overall scope of the same. The product compounds are identified by elemental analysis and/or nuclear magnetic resonance spectroscopy.
EXAMPLE 1--Preparation of .Badd..[.2,6-Dichloro-N-(((4-trifluoromethoxy)phenyl)amino)carbonyl)-benzamide.]..Baddend. .Iadd.2,6-Dichloro-N-(((4-(trifluoromethoxy)phenyl)amino)carbonyl)-benzamide .Iaddend.
Five grams (0.03 mole) of α,α,α-trifluoro-p-anisidine and 6.5 grams (0.03 mole) of 2,6-dichlorobenzoyl isocyanate were added to 100 milliliters of benzene and heated under reflux with stirring for 1 hour. The benzene was removed by evaporation. The solid residue was slurried in 100 milliliters of cold hexane. The residual material was collected by filtration, washed with hexane and dried, leaving a crude product which was a white solid melting at 170°-180° C. This was purified by recrystallization from 60 milliliters of 85 percent of aqueous acetic acid. The yield was 7 grams (61 percent of theoretical) of a white solid melting at 188°-190° C.
The structure of the product was confirmed by nuclear magnetic resonance spectroscopy (NMR) as being ##STR12##
Elemental Analysis--Theory: C, 45.82%; H, 2.31%; N, 7.13%. Found: C, 45.60%; H, 2.41%; N, 7.24%.
EXAMPLE 2--Preparation of 2,6-Dichloro-N-(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)amino)carbonyl)-benzamide
In 200 milliliters of xylene, 11.5 grams (0.04 mole) of β,β-dichloro-α,α-difluoro-p-phenetidine.HCl and 3.6 grams (0.04 mole) of 2,6-dichlorobenzoyl isocyanate were refluxed with stirring for two hours. The xylene was thereafter removed by vacuum distillation. The residue which remained was mixed with 200 milliliters of hexane and a crystalline solid precipitated. This precipitated material was collected by suction filtration, washed with hexane and dried. The dried crude product was a light tan gummy solid melting at 160°-185° C. This crude product was purified by recrystallization from 60 milliliters of 83 percent aqueous acetic acid, leaving 85 grams of a white solid melting at 211°-213° C. (56 percent of theoretical). Nuclear magnetic resonance spectroscopy confirmed the structure as being ##STR13##
Elemental Analysis--Theory: C, 41.95%; H, 2.20%, N, 6.12%. Found: C, 41.8%; H, 2.17%; N, 6.33%.
Using methods in accordance with those detailed above, the compounds of Examples 3-27 were prepared. These compounds and their melting points are set forth in Table 1.
TABLE 1__________________________________________________________________________ExampleCompound Melting pt. (°C.)__________________________________________________________________________ 3 2-Chloro-N--(((4-(trifluoromethoxy)phenyl)amino)carbonyl)-benzo- 188-190mide 4 2-Trifluoromethyl-N--(4-(trifluoromethoxy)phenyl)amino)carbonyl)- 157-159benzamide 5 2,6-Dichloro-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)car- 187-189bonyl)-benzamide 6 2,6-Difluoro-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)car- 212-215bonyl)-benzamide 7 2,6-Difluoro-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 216-218amino)carbonyl)-benzamide 8 2,6-Difluoro-N--(((4-(trifluoromethoxy)phenyl)amino)carbonyl)- 220-222benzamide 9 2,6-Difluoro-N--(((2-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 161-164amino)carbonyl)-benzamide10 2,6-Difluoro-N--(((4-((2,2-dichloro-1,1-difluoroethyl)thio)phenyl)- 197-199amino)carbonyl)-benzamide11 2,6-Dimethoxy-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)car- 151.154bonyl)-benzamide12 2,6-Dichloro-N--(((2-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 206-208amino)carbonyl)benzamide13 2,6-Dichloro-N--(((4-((2,2-dichloro-1,1-difluoroethyl)thio)phenyl)- 208-211amino)carbonyl)-benzamide14 2-Chloro-N--(((2-(2,2-dichloro-1,1-difluoroethoxy)phenyl)amino)car- 152-154.Iadd.bonyl)-benzamide.Iaddend.15 2-Chloro-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)amino)- 142-145carbonyl)-benzamide16 2-Chloro-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)carbonyl)- 192-194benzamide17 2-Chloro-N--(4-(((2,2-dichloro-1,1-difluoroethylthio)phenyl)amino)- 150-153carbonyl)-benzamide18 2,6-Dichloro-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 120-124amino)carbonyl)-N --methylbenzamide19 2,6-Dichloro-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 159-163methylamino)carbonyl)-benzamide20 2,6-Difluoro-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 98-100methylamino)carbonyl)-benzamide21 2,6-Dibromo-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)car- 197-199bonyl)-benzamide22 2-Bromo-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)carbonyl)- 184-186benzamide23 2-Chloro-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)methyl- 99-103amino)carbonyl)-benzamide24 2-Fluoro-N--(((4-(1,1,2,2-tetrafluoroethoxy)phenyl)amino)carbonyl)- 182-184benzamide25 2-Trifluoromethyl-N--(((4-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 100-102methylamino)carbonyl)-benzamide26 2,6-Difluoro-N--(((3-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 177-179amino)carbonyl)-benzamide27 2,6-Dichloro-N--(((3-(2,2-dichloro-1,1-difluoroethoxy)phenyl)- 188-192amino)carbonyl)-benzamide28 2,6-Difluoro-N--(((4-((1,1,2,2-tetrafluoroethyl)thio)phenyl)- 198-200amino)carbonyl)-benzamide29 2,6-Dichloro-N--(((4-(1,1,2,2-tetrafluoroethyl)thio)phenyl)- 219-221.5amino)carbonyl)-benzamide__________________________________________________________________________
The isocyanate starting material for Method A is synthesized by treating the corresponding benzamide with oxalyl chloride in the presence of a solvent such as a chlorinated hydrocarbon.
The anisidine starting material of Method A is known in the prior art and may be made by the procedure delineated in C.A.51:15518C. Phenetidine starting materials can be prepared by the procedure set forth in C.A.76:P722169 (Ger. Offen. No. 2,029,556).
Examples of other methods of making the starting material for Method A are shown in U.S. Pat. No. 3,748,356.
The compounds of the present invention have been found to be useful in methods for the killing and control of various undesirable agricultural and household insects such as cabbage looper, beet army worm and the larvae of mosquitoes, hornflies and houseflies. The compounds are highly active and can be employed to both kill insects outright and/or to prevent adult emergence from juvenile forms of the insect. In such applications, the insect to be controlled and/or its habitat is contacted or treated with an insecticidal amount of one or more of the compounds of the present invention.
For all such uses, these compounds can be employed in unmodified form. However, the present invention embraces the use of an insecticidally-effective amount of the active ingredients in composition form with a material known in the art as an adjuvant or carrier.
Thus, for example, compositions employing one or a combination of these active ingredients can be in the form of a liquid or a dust; and the adjuvant employed can be any one of a plurality of materials including aromatic solvents, petroleum distillates, water or other liquid carriers, propellant substances, surface-active dispersing agents, light absorbers and finely-divided carrier solids.
The exact concentration of one or a combination of the compounds of the present invention in a composition thereof with an adjuvant therefor can vary; it is only necessary that one or a combination of the compounds be present in a sufficient amount so as to make possible the application of an insecticidally-effective or inactivating dosage.
Suitable adjuvants of the foregoing type are well known to those skilled in the art. The methods of applying the solid or liquid insecticidal formulations are similarly well known in the art.
The insecticidally-effective dosage desirable for effective use of preparations containing active compounds will naturally depend on various factors such as the active ingredient or ingredients chosen and the form of preparation. Moreover, the activities of the compounds of the present invention against different insects will vary from compound to compound. Generally, for practical applications, one or a combination of these active ingredients can be broadly applied to the insect larvae or their habitat in compositions containing from about 0.0001 percent to about 98 percent by weight of the compounds.
In the preparation of dust compositions, these compounds can be compounded with any of the finely-divided carrier solids such as pyrophyllite, diatomaceous earth, gypsum and the like. In such operations, the finely-divided carrier is ground or mixed with one or a combination of the compounds, as active agent(s), or wetted with a solution of the active agent(s) in a volatile organic solvent. Similarly, dust compositions can be compounded with various solid dispersing agents, such as fuller's earth, attapulgite and other clays. These dust compositions can be employed as treating compositions or can be employed as concentrates and subsequently diluted with additional solid dispersing agents or with pyrophyllite, diatomaceous earth, gypsum and the like to obtain the desired amount of active agent in a treating composition. Also, such dust compositions can be dispersed in water, with or without the aid of a surfactant, to form spray mixtures.
Furthermore, one or a combination of the compounds or a dust concentrate composition containing such compound(s) can be incorporated in intimate admixture with surface-active dispersing agents such as ionic and nonionic emulsifying agents to form spray concentrates. Such concentrates are readily dispersible in liquid carriers to form sprays containing the toxicant(s) in any desired amount. The choice of the dispersing agent and amount thereof employed are determined by the ability of the agent to facilitate the dispersion of the concentrate in the liquid carrier to produce the desired spray composition.
In the preparation of liquid compositions, one or a combination of the products can be compounded with a suitable water-immiscible organic liquid and surface-active dispersing agent to produce an emulsifiable liquid concentrate which can be further diluted with water and oil to form spray mixtures in the form of oil-in-water emulsions. In such compositions, the carrier comprises an aqueous emulsion, that is, a mixture of water-immiscible solvent, emulsifying agent and water. Preferred dispersing agents to be employed in these compositions are oil soluble and include the nonionic emulsifiers such as the polyoxyethylene derivatives of sorbitan esters, complex ether alcohols and the like. However, soil-soluble-ionic emulsifying agents such as mahogany soaps can also be used. Suitable organic liquids to be employed in the compositions include petroleum oils and distillates, toluene, liquid halohydrocarbons and synthetic organic oils.
An aerosol preparation according to the invention is obtained in the usual manner by incorporating the active substance and a solvent in a volatile liquid suitable for use as a propellant, such as the mixture of chlorine and fluorine derivatives of methane and ethane commercially available under the trademark FREON®.
Fumigating candles or fumigating powders, i.e., preparations which when burning are capable of emitting a pesticidal smoke, are obtained by taking up the active substance in a combustible mixture which may contain: (a) a sugar or a wood, preferably in ground form, as a fuel; (b) a substance to maintain combustion such as, for example, ammonium nitrate or potassium chlorate and (c) a substance to retard the combustion such as, for example, kaolin, bentonite and/or colloidal silicic acid.
When utilizing the active ingredients of the present invention as insecticides, one or a combination of the active ingredients or a composition containing such is applied to the insects or insect larvae directly, or by means of application to their habitat in any convenient manner, for example, by means of hand dusters or sprayers or by simple mixing with the food to be ingested by the insects or larvae. Application to the foliage of plants is conveniently carried out with power dusters, broom sprayers and fog sprayers. In such foliar applications, the compositions to be employed should not contain any appreciable amounts of any phytotoxic diluents. In large scale operations, dusts or low volume sprays can be applied from an airplane.
In representative activity tests, compounds of the present invention were formulated into emulsifiable solutions and added to cups containing water to thereby produce various concentrations of the compounds as the active toxicant in the water. Twenty third-stage larvae of the southern house mosquito, Culex quinquefasciatus Say, were added to the water in each cup and incubated at 80° F. until all adults had sufficient time to hatch. An untreated control was also incubated. After one week, all larvae in the control cup had hatched into normal adult mosquitoes. Table 2 sets forth the lowest concentration of each active compound which achieved 100% kill and control of the larvae directly or of the pupae as they began their moult into adults.
The compounds are referred to by their Example number.
TABLE 2__________________________________________________________________________Compound of Example Number 2 4 5 7 8 10 11 13 15 17 26__________________________________________________________________________Lowest Concentration Achieving 0.005 1 0.1 0.1 0.00025 0.0025 1.0 0.01 0.1 0.1 0.1100% Kill and Control (ppm)__________________________________________________________________________
In additional representative activity tests, selected compounds of the present invention were formulated into emulsifiable solutions which were added to cups containing 200 grams of fresh cow manure. The compounds were added to the manure in 5 cubic centimeters of water and stirred thoroughly with a handheld electric mixer. The samples were seeded with 200 housefly eggs and allowed to incubate until all flies had completed their development and had emerged as adults. Percent control was determined by comparison with untreated samples and active compounds were retested at lower doses until a break point was found. Table 3 sets forth the lowest concentration of each active compound which achieved 100% kill and control of the larvae directly or of the pupae as they began their moult into adults.
TABLE 3______________________________________Compound of Example Number 5 6 10 13 16 17______________________________________Concentration (ppm) 50 10 50 50 10 25______________________________________
The compounds set forth below were separately made into a water emulsion and mixed into 200 grams fresh cow manure. Approximately 500 hornfly eggs collected from colony flies were placed in the manure. The samples were allowed to incubate until all flies had completed their development and were emerging as adults. Percent control was determined by comparison with untreated samples and active compounds were related until a break point was found. Table 4 sets forth the lowest concentration of each active compound which achieved 100% kill and control of the larvae directly or of the pupae as they began their moult into adults.
TABLE 4__________________________________________________________________________Compound of Example Number 5 6 7 10 11 13 15 16 17 22 24 28 29__________________________________________________________________________Concentration (ppm) 50 <0.1 1.0 0.5 10 10 25 10 1.0 10 25 <25 <1.0__________________________________________________________________________
In an additional operation, a representative compound of the present invention was tested for insecticidal performance against the cabbage looper in standard greenhouse and field testing procedures. The results of the operation are set forth in Table 5.
TABLE 5______________________________________ Percent Larvae MortalityCompound of Active Ingredient Cabbage LooperExample Number (Kilogram/Hectare) GHT FT______________________________________1 0.2 83 981 0.05 55 82______________________________________ GHT = Greenhouse Test FT = Field Test
In additional representative activity tests, compositions containing selected active ingredients of the present invention were applied to the habitat of beet army worm larvae (Spodoptera exigera). Table 6 sets forth the lowest concentration of each active ingredient, referred to by example number, which achieved 90% kill and control (LC 90 ) of the larvae.
TABLE 6__________________________________________________________________________Compound of Example Number 1 2 5 6 7 8 13 15 17 18 19 28 29__________________________________________________________________________Lowest Concentration 5 8 7 67 102 10 19 100 62 11 75 46 13Achieving 90% Kill and Control__________________________________________________________________________
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Novel alkoxy or alkylthio substituted(((phenyl)amino)carbonyl)-benzamides are disclosed. The compounds of the instant invention are useful as insecticides and can be formulated to provide insecticidal compositions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 13/906,603 filed May 31, 2013, which, claims priority to European Patent Application No. 12177731.2 filed Jul. 24, 2012, the disclosure of which is incorporated in its entirety by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to a method of mounting a carrier of a disc brake to a mount, and/or a carrier and mount assembly.
BACKGROUND
[0003] Disc brakes, for example air actuated disc brakes are commonly used for braking heavy vehicles such as trucks, buses and coaches. There are many types of disc brakes available. An example of one of the many types of pneumatic disc brakes is shown in FIG. 1 .
[0004] Referring to FIG. 1 , the disc brake 110 has a carrier 112 that carries a caliper 114 . The carrier also carries friction elements 122 such that one friction element is positioned on each side of a rotor 116 of the disc brake 110 . An air actuator is provided for moving an inboard friction element into frictional contact with the rotor 116 via an actuator mechanism (not shown). The rotor 116 is fixed in an inboard-outboard direction, so that when the inboard friction element is pushed towards and contacts the rotor 116 , further pushing of the inboard friction element towards the rotor 116 causes the caliper 114 to move inboard. As the caliper 114 moves inboard it moves the outboard friction element towards the rotor 116 clamping the rotor 116 between the outboard and the inboard friction elements 122 and thereby effecting braking by frictionally inhibiting rotation of the rotor 116 .
[0005] In use, the disc brake is mounted to an axle of a vehicle. This may be achieved by connecting the carrier to a mount on the axle, typically via a bracket welded to the axle. Bolts arranged parallel to an axis of rotation of the rotor secure the carrier to the mount.
[0006] Alternatively, for example where an axle has a flange for connection to a drum brake, the carrier is generally attached to a separate mount, often referred to as an adapter plate, and the separate mount is connected to the flange. Axial mounting may result in difficulty in accessing bolts to assemble/disassemble the brake, as well as increase the weight of the brake due to the material doubling at the interface between the mount and carrier. Accordingly, tangential mounting may be used, i.e. the carrier is mounted to the mount via fasteners (e.g. bolts) that extend in a direction tangential to the rotor and substantially perpendicular to the axis of rotation of the rotor.
[0007] Features of the carrier and mount generally enable the carrier to be accurately mounted to the axle in a direction A parallel to an axis of rotation of the rotor 116 . However, there may be difficulties aligning the carrier with respect to a rotor of a disc brake. Referring to FIG. 2 , misalignment of the carrier can result in the rotor 116 and friction element 122 being misaligned, such that the friction element 122 is spaced from the rotor by a greater distance 121 at one side of the friction element than at an opposite side of the friction element. This misalignment can result in taper (i.e. uneven) pad wear and/or non-uniform loading of the caliper mechanism and components. This may be particularly problematic in brakes where bolts secure the carrier to the mount in a tangential or chordal direction (so-called tangential mount carriers), as there may be no overlap of faces of the carrier and mount in the axial direction to aid alignment. This problem is particularly problematic in heavy vehicles rather than lighter vehicles because the larger dimensions of heavy vehicle brakes tend to amplify the effects of any misalignment.
SUMMARY
[0008] The present invention seeks to alleviate problems associated with the prior art.
[0009] In a first aspect of the invention there is provided a carrier and mount assembly for a heavy vehicle disc brake, the assembly comprising: a carrier having a first location formation formed therein, a mount having a second location formation formed therein, wherein the second location formation is aligned with the first location formation, and wherein the carrier is mounted to the mount via two or more fasteners that extend in a direction substantially parallel to a direction of insertion or removal of a friction element into or from the carrier; and a locator positioned in the first and second location formations to enable the carrier and mount to be assembled in the correct position, wherein the locator is at least a close fit to the first and second location formations.
[0010] The mounting assembly of the first aspect has been found to ease alignment of the carrier to the mount so as to ensure correct alignment of the carrier to the rotor.
[0011] A close fit may be a transitional fit or an interference fit. For example, when the close fit is a transitional fit, the fit may have a clearance of between 0 mm to 0.04 mm.
[0012] The carrier may be seated on the mount such that planar contacting surfaces of the carrier and mount extend in a plane substantially perpendicular to a plane of a rotor and parallel to an axis of rotation of a rotor of a disc brake.
[0013] The first location formation and the second location formation may be positioned to extend in a direction substantially parallel to a direction of insertion or removal of a friction element into or from the carrier.
[0014] Only one locator may be provided in the carrier and mount assembly. Provision of only one locator has been found to ease assembly whilst sufficiently permitting correct alignment of the carrier and mount to reduce taper pad wear.
[0015] The first location formation is a hole formed in the carrier and the second location formation is a hole formed in the mount, and the locator is positioned in the first location formation and the second location formation.
[0016] In the present application a hole defines an enclosed channel that extends fully or partially through a component. For example, a hole may have a circular or oval cross section.
[0017] The carrier may comprise two holes arranged such that one hole is positioned on either side of a plane defined by an axis extending substantially parallel to a direction of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The mount may comprise two holes positioned to be substantially coaxial with the two holes of the carrier. One of the two or more fasteners may extend through each of the holes for mounting the carrier to the mount. For example, the fasteners may be threaded bolts and the two holes may be threaded to mate with the threaded bolt.
[0018] The carrier may comprise two further holes arranged such that one further hole is positioned on either side of a plane defined by an axis extending substantially parallel to a direction of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The mount may comprise two further holes positioned to be substantially coaxial with the two further holes of the carrier. One of the two or more fasteners may extend through each of the further holes for mounting the carrier to the mount. For example, the fasteners may be threaded bolts and the two further holes may be threaded to mate with the threaded bolt.
[0019] The two holes, the two further holes, and the first and second location formations may be arranged in line in a direction substantially perpendicular to an axis of rotation of a rotor of a disc brake, and substantially perpendicular to a direction substantially parallel to a direction of insertion or removal of a friction element into or from the carrier.
[0020] The first location formation and the second location formation may be positioned between one of the holes and one of the further holes.
[0021] The carrier and mount assembly may comprise a location hole formed in the carrier and a location hole formed in the mount. The location hole in the carrier and the location hole in the mount may have similar dimensions to the first and second location formation. The location hole may be on an opposite side to the first and second location formations of a plane defined by an axis extending substantially parallel to a direction of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake.
[0022] The locator may be a bush. The bush may extend at least partially through the first and second location formations. The bush may be a split bush. Use of a split bush eases assembly. An end of the bush that may be received in the mount may have a chamfered outer edge. Provision of a chamfered edge also eases assembly.
[0023] The carrier may comprise two holes arranged such that one hole is positioned on either side of a plane defined by an axis extending substantially parallel to a direction of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The mount may comprise two holes positioned to be substantially coaxial with the two holes of the carrier. One of the two or more fasteners may extend through each of the holes for mounting the carrier to the mount. For example, the fasteners may be threaded bolts and the two holes may be threaded to mate with the threaded bolt.
[0024] The first location formation may be integrally formed with one of the holes in the carrier and the second location formation may be integrally formed with one of the holes in the mount.
[0025] The first location formation may be a portion of one of the holes and the second location formation may be a portion of one of the holes, and the first and second location formations may have a larger diameter than the remainder of the holes.
[0026] The two holes may be threaded to receive a threaded fastener along the length thereof, excluding the first and second location formations.
[0027] The carrier and mount assembly may comprise a further bush positioned to extend at least partially through the other of the two holes formed in the carrier and mount. The further bush may be a loose fit to the hole in the mount. A loose fit may be a fit having a clearance greater than 0.04 mm.
[0028] The carrier and the mount may include two further holes positioned such that one further hole is positioned on either side of a plane defined by an axis extending substantially parallel to a direction of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The mount may comprise two further holes positioned to be substantially coaxial with the two further holes of the carrier. The bushes may be located in the holes nearest an axis of rotation of a rotor.
[0029] In a second aspect the invention provides a method of mounting a carrier of a disc brake to a mount, the method comprising: providing a carrier to be mounted having a first location formation; providing a mount having a second location formation alignable with the first location formation; positioning a locator in the first and second location formation to support the carrier in alignment with respect to the mount so as to correctly position the carrier with respect to the mount; and mounting the carrier to the mount using fasteners that in a mounted position extend in a direction substantially parallel to a direction of insertion or removal of a friction element into or from the carrier; wherein the first and second location formations are formed to be a close fit with the locator.
[0030] The first location formation may be a hole in the carrier and the second location formation may be a hole in the mount, and the first and second location formations may be positioned to be coaxial when the carrier is mounted to the mount. The locator may be a peg, and the method may comprise positioning the peg in the hole in the carrier, and then mounting the carrier with the peg to the mount.
[0031] Two holes may be provided in the carrier and mount positioned to be on either side of a rotor, and the two holes may be dimensioned for receipt of the locator. The method may comprise positioning the locator in only one of the two holes of the carrier and mount, and then mounting the carrier to the mount.
[0032] Wherein the carrier is mounted to the mount via a fastener at a position near the locator and a position further from the locator. The step of mounting the carrier to the mount may comprise fastening the carrier to the mount at a position further from the locator, and subsequently at a position near the locator.
[0033] The carrier, mount and locator may be the carrier, mount and locator of the carrier and mount assembly of the first aspect.
[0034] In a third aspect of the present invention there is provided a method of mounting a carrier of a disc brake to a mount, the method comprising: providing a carrier or caliper to be mounted having a first location formation; providing a mount having a second location formation alignable with the first location formation; positioning a locator in the first and second location formation to support the carrier or caliper in alignment with respect to the mount so as to correctly position the carrier or caliper with respect to the mount; mounting the carrier or caliper to the mount; and removing the locator from the location formation for normal use of the disc brake.
[0035] The method of the present invention permits the carrier to be correctly positioned with respect to the mount in both a direction parallel to an axis of rotation of a rotor of a disc brake and in a plane parallel to a plane of a rotor of a disc brake. This means that when the disc brake having said mount and carrier are mounted to an axle of a vehicle, friction elements of the disc brake are substantially aligned with the rotor alleviating the above described problem of taper pad wear and non-uniform loading of the caliper mechanism and components.
[0036] Throughout the present application directions of features of the mount and/or carrier are referred to with respect to a rotor of a disc brake of which the carrier may be a component thereof. The directions are shown by arrows in FIG. 1 and later described FIG. 3 . Direction A is a direction through an axis of rotation of a rotor of a disc brake and is substantially perpendicular to a plane substantially parallel to a planar face of the rotor; a direction T is a direction tangential to a to a circle described by rotation of a rotor of a disc brake and generally parallel or aligned with a direction of insertion or removal of a friction element into or from the carrier; and a direction R is a direction substantially perpendicular to both of the axes defined by direction A and direction T respectively (i.e. is generally aligned with a width of the carrier).
[0037] The first location formation may be positioned in alignment with the second location formation, and then the locator may be positioned in the first and second location formation. Alternatively, the first and second location formations may be positioned in substantial alignment, and the step of positioning the locator in the first and second location formation may correctly align the first and second location formations.
[0038] The mount may be directly connected to an axle, for example by welding, or may be connected to a flange of an axle, for example using bolts. Alternatively, the mount may be part of a steering knuckle on a steered axle.
[0039] The locator may be a single locator positionable in both the first and the second location formations. The locator may be a dowel.
[0040] The location formations may be locator channels. The location formations may comprise a non-threaded surface. For example, the location formations may comprise a substantially smooth surface.
[0041] The first and/or second location formation may be provided on a surface of the carrier and/or mount, respectively. The first and/or second location formation may be provided entirely on a surface of the carrier and/or mount, respectively.
[0042] The first and second location formations may be positioned in co-axial alignment. Such alignment permits a locator such as a dowel to be more easily positioned in both the first and second location formation.
[0043] The carrier may be attached to the mount using two or more fasteners. Alternatively, the carrier may be attached to the mount by welding.
[0044] The first or second location formation may be a groove formed in a respective surface of the carrier and/or mount. The first and/or second location formations may be linear grooves. The groove may have a substantially semi-circular cross section.
[0045] The first location formation may be a groove positioned to be aligned and in opposition to the second location formation to form a conjoined location formation, to receive the locator. The locator may be a dowel, and the dowel may have a similar cross-section to the cross-section of the conjoined location formation. The first and second location formations may be provided to be in a direction in the plane of rotation of a rotor of the disc brake and substantially perpendicular to an axis through a center of rotation of a rotor and substantially perpendicular to a direction tangential to a rotation of a rotor. The method may comprise providing a first seat adjacent one or more sides of the first location formation and a second seat adjacent one or more sides of the second location formation, and positioning the first and second seats in opposition and abutment. The seats may be formed by machining a surface of the mount and carrier. The seat can further improve the accuracy with which the carrier can be positioned with respect to the mount.
[0046] The seats may be in a plane defined by directions A and T, i.e. they may be chordal with respect to a circle described by rotation of the rotor, and may further be provided either side of an axle, and may be co-planar
[0047] The locator may be a component of a clamping device.
[0048] Alternatively, the first location formation may be a hole formed in the carrier and the second location formation may be a hole formed in the mount.
[0049] The first and/or second location formation may have a non-circular cross-section. In exemplary embodiments, the first and/or second location formation may have a directional component in a direction corresponding to a plane of rotation of a rotor of the disc brake.
[0050] The method may comprise coaxially aligning a bore formed in the carrier and the mount for receiving a fastener for mounting, with the first and/or second location formation. The first and/or second location formation may comprise a slot having a directional component in a direction corresponding to a plane of rotation of a rotor of the disc brake. For example, the slot may be rectangular or oval. In such embodiments, the locator may be a dowel having a rectangular or oval cross section. Alternatively, the locator may be a dowel having a cross section substantially similar to the cross section of the hole.
[0051] The first location formation may extend partially through the carrier and the second location formation may extend entirely through the mount, or the second location formation may extend partially through the carrier and the first location formation may extend entirely through the mount. Alternatively, the first location formation may extend entirely through the carrier and the second location formation may extend entirely through the mount.
[0052] The step of mounting the carrier to the mount may use a fastener. In such embodiments, the method may comprise the step of using the fastener to drive the locator through the hole as the fastener is fastened to the mount and carrier. The step of mounting the carrier to the mount may comprise using two or more fasteners, for example four fasteners.
[0053] In exemplary embodiments, the hole may be dimensioned to be a close fit with the locator. The locator may be a pin. The locator may be a bolt. In such embodiments, the method may comprise screwing the bolt into the first and second location formations.
[0054] A hole may define the first and/or second location formation. The hole defining the first location formation may extend entirely through the carrier, and/or the hole defining the second location formation may extend entirely through the mount.
[0055] The first and second location formations may be positioned to be in a direction tangential to a direction of rotation of a rotor of a disc brake and generally aligned with the abutments on the carrier to support end faces of the friction elements. Alternatively, the first and second location formations may be positioned to be in a tangential direction of rotation of a rotor and parallel to a plane defined by a face of a rotor of a disc brake, but normal abutments on the carrier to support end faces of the friction elements.
[0056] The first and second location formations may be formed by milling or broaching.
[0057] In a fourth aspect of the present invention there is provided a method of mounting a carrier of a disc brake to a mount, the method comprising: providing a carrier to be mounted having a first location formation; providing a mount having a second location formation alignable with the first location formation; positioning a locator in the first and second location formation to support the carrier in alignment with respect to the mount so as to correctly position the carrier with respect to the mount; and mounting the carrier to the mount; wherein the first and the second location formations are axial channels and are positioned to be in a direction parallel to a plane of rotation of a rotor of the disc brake and transverse to a direction tangential to a rotation of the rotor.
[0058] The first and second location formations may be positioned to be substantially perpendicular to a direction tangential to a rotation of the rotor.
[0059] The locator may remain positioned in the first and/or second location formation during normal use of the disc brake. Alternatively, the locator may be removed from the first and/or second location formation for normal use.
[0060] As will be appreciated by a person skilled in the art, many of the optional features of the third aspect may be used in combination with the method of the fourth aspect.
[0061] In a fifth aspect of the present invention there is provided a method of mounting a carrier of a disc brake to a mount, the method comprising: providing a carrier to be mounted having a first location formation; providing a mount having a second location formation alignable with the first location formation; positioning a locator in the first and second location formation to support the carrier in alignment with respect to the mount so as to correctly position the carrier with respect to the mount; and mounting the carrier to the mount using two or more fasteners; wherein the first and second location formations are formed coaxially with a bore for receiving the two or more fasteners.
[0062] The locator may remain positioned in the first and/or second location formation during normal use of the disc brake. Alternatively, the locator may be removed from the first and/or second location formation for normal use.
[0063] As will be appreciated by a person skilled in the art, many of the optional features of the third aspect may be used in combination with the method of the fifth aspect.
[0064] In a sixth aspect of the present invention there is provided a method of mounting a carrier of a disc brake to a mount, the method comprising: providing a carrier to be mounted having a first location formation; providing a mount having a second location formation alignable with the first location formation; positioning a locator in the first and second location formation to support the carrier in alignment with respect to the mount so as to correctly position the carrier with respect to the mount; and mounting the carrier to the mount; wherein the first and second location formations are formed to be a close fit with the locator.
[0065] The locator may remain positioned in the first and/or second location formation during normal use of the disc brake. Alternatively, the locator may be removed from the first and/or second location formation for normal use.
[0066] As will be appreciated by a person skilled in the art, many of the optional features of the third aspect may be used in combination with the method of the sixth aspect.
[0067] In a seventh aspect of the present invention there is provided a carrier or caliper and a mount assembly, the carrier or caliper having a first location formation formed therein, and the mount having a second location formation formed therein, the first and second location formations being alignable such that during assembly of the carrier or caliper and mount a locator can be positioned in the first and second location formation to enable the carrier or caliper and mount to be assembled in the correct position, and the locator can be removed from the assembly during normal use.
[0068] As will be appreciated by a person skilled in the art, many of the optional features of the method of the third aspect where applicable can be combined with the assembly of the seventh aspect.
[0069] In an eighth aspect of the present invention there is provided a carrier or caliper and a mount assembly, the carrier or caliper having a first location formation formed therein, and the mount having a second location formation formed therein, the first and second location formations being alignable such that during assembly of the carrier or caliper and mount a locator can be positioned in the first and second location formation to enable the carrier or caliper and mount to be assembled in the correct position, wherein the first and the second location formations are axial channels and are positioned to be in a direction parallel to a plane of rotation of a rotor of the disc brake and transverse to a direction tangential to a rotation of the rotor.
[0070] As will be appreciated by a person skilled in the art, many of the optional features of the method of the fourth aspect where applicable can be combined with the assembly of the eighth aspect.
[0071] In a ninth aspect of the present invention there is provided a carrier and a mount assembly, the carrier having a first location formation formed therein, and the mount having a second location formation formed therein, the first and second location formations being alignable such that during assembly of the carrier and mount a locator can be positioned in the first and second location formation to enable the carrier and mount to be assembled in the correct position; and the assembly comprising two or more fasteners attaching the carrier to the mount, and wherein the first and second location formations are formed coaxially with a bore for receiving the two or more fasteners.
[0072] As will be appreciated by a person skilled in the art, many of the optional features of the method of the fifth aspect where applicable can be combined with the assembly of the ninth aspect.
[0073] In a tenth aspect of the present invention there is provided a carrier and a mount assembly, the carrier having a first location formation formed therein, and the mount having a second location formation formed therein, the first and second location formations being alignable such that during assembly of the carrier and mount a locator can be positioned in the first and second location formation to enable the carrier and mount to be assembled in the correct position, and wherein the first and second location formations are formed to be a close fit with the locator.
[0074] As will be appreciated by a person skilled in the art, many of the optional features of the method of the sixth aspect where applicable can be combined with the assembly of the tenth aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] Embodiments of the present invention will now be described with reference to the accompanying drawings in which:
[0076] FIG. 1 shows a perspective view of a disc brake of the prior art;
[0077] FIG. 2 shows a schematic plan view of a rotor and friction element of a disc brake of the prior art;
[0078] FIG. 3 shows a partial perspective view of a carrier and mount assembly according to an embodiment of the present invention;
[0079] FIG. 4 shows a carrier and mount assembly according to another embodiment of the present invention;
[0080] FIG. 5 shows a carrier and mount assembly according to a further embodiment of the present invention;
[0081] FIG. 6 shows the carrier and mount assembly of claim 6 at an intermediate step in a method of assembly according to an embodiment of the present invention;
[0082] FIG. 7 shows a front view of a carrier and mount assembly according to an embodiment of the present invention;
[0083] FIG. 8 shows a perspective view of the carrier and mount assembly of FIG. 7 ;
[0084] FIG. 9 shows a plan view of a carrier and mount assembly of a further embodiment of the present invention;
[0085] FIG. 10 shows a partial perspective view of the carrier and mount shown in FIG. 9 ;
[0086] FIG. 11 shows a partially sectioned perspective view of a carrier and mount according to an alternative embodiment;
[0087] FIG. 12 shows a perspective view of a carrier of the carrier shown in FIG. 11 ;
[0088] FIG. 13 shows a perspective view of a mount shown in FIG. 11 ;
[0089] FIG. 14 shows a perspective view of the carrier and mount of FIG. 11 partially assembled;
[0090] FIG. 15 shows a partially sectioned carrier and mount according to a further alternative embodiment;
[0091] FIG. 16 shows a front view of a locator of the carrier and mount of FIG. 15 ; and
[0092] FIG. 17 shows a perspective view of a carrier and mount of FIG. 15 in a non-mounted state.
DETAILED DESCRIPTION
[0093] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0094] Referring to FIG. 3 , a carrier and mount assembly of a disc brake according to an embodiment of the present invention is indicated generally at 10 a . Like parts are labeled by like numerals in the description below, but with differing suffix letters.
[0095] A carrier 12 a is positioned on a mount 24 a . In this embodiment the mount is an adapter plate of the type for mounting to a drum brake. A mount of this type (mount 24 d ) is shown more clearly in another embodiment illustrated in FIGS. 8 and 9 . The mount 24 a /d has a circular central section 50 a /d with holes 52 a /d spaced circumferentially around the central section. The holes 52 a /d can receive bolts (not shown) to bolt the mount to a mounting for a drum brake. An upper end of the mount 24 a /d (as viewed in the figures) is provided with a support 54 a /d that extends chordally each side of the central section for supporting a carrier 12 a /d.
[0096] The support 54 d comprises a planar surface 28 a that abuts a planar surface 26 a of the carrier. The planar surfaces 26 a and 28 a are positioned on either side of the carrier 12 a and the mount 24 a , i.e. chordally either side of an axle, and are coplanar. However, in alternative embodiments the planar surfaces 26 a , 28 a on each side of the carrier 12 a and mount 24 a may be angled with respect to each other. In such embodiments the planar surfaces 26 a , 28 a at one side may be substantially perpendicular to a planar surfaces 26 a , 28 a at the other side of the carrier 12 a and mount 24 a.
[0097] Referring to FIGS. 3 to 10 , throughout the present detailed description directions of features of the mount 24 a , 24 b , 24 c , 24 d , 24 e and/or carrier 12 a , 12 b , 12 c , 12 d , 12 e are referred to with respect to a rotor of a disc brake, of which the carrier may be a component thereof. Direction A is a direction through an axis of rotation of a rotor of a disc brake and is substantially perpendicular to a plane substantially parallel to a planar face of the rotor, referring to FIG. 8 , in this embodiment the rotor (not shown) of a disc brake will be positioned to be in a plane substantially parallel to the plane defined by the circular central section 50 d . Direction T is a direction tangential to a circle described by rotation of a rotor of a disc brake (which in the embodiment shown in FIG. 8 is also tangential to the central circular section 50 d ) and generally parallel or aligned with a direction of insertion or removal of a friction element into or from the carrier.
[0098] Referring to FIGS. 7 and 8 , one friction element is inserted into one of an upper rectangular receiving region or window 56 d on each axial side of the carrier, and the direction of insertion or removal of a friction element is, in this embodiment, aligned with two opposing sides 58 d of the rectangular receiving region 56 d and is indicated in FIG. 8 by arrow I. Direction R is a direction substantially perpendicular to both of the axes defined by direction A and direction T respectively (i.e. is generally aligned with a width of the carrier).
[0099] A location formation, in this embodiment a groove 32 a , is formed in the planar surface 26 a of the carrier and a location formation, in this embodiment a groove 30 a is formed in the planar surface 28 a of the mount 24 a . The grooves 30 a , 32 a are linear, longitudinal grooves each with a semi-circular cross section. The grooves 30 a , 32 a extend in the direction R. In this embodiment, the groove 30 a , 32 a in the carrier and the mount are positioned such that when the carrier is correctly positioned with respect to the mount the grooves are coaxially aligned and form a conjoined location formation. In this embodiment, the conjoined location formation is a channel with a circular cross section.
[0100] A seat 34 a is machined on either side of the groove 30 a and the groove 32 a . Such a machined seat 34 a provides a surface profile and roughness correct for more accurate alignment of the two grooves 30 a and 32 a , and consequently more accurate alignment of the carrier with respect to the mount.
[0101] To attach the carrier 12 a to the mount 24 a , the carrier is correctly positioned with respect to the mount, such that the groove 30 a of the mount is aligned with the groove 32 a of the carrier. A locator, in this embodiment a dowel (not shown in FIG. 3 ), is then positioned in the conjoined locator channel 31 a . The dowel is a close fit to the locator channel 31 a , a close fit may equate to a maximum clearance of 0.1 mm. The carrier is then attached to the mount using fasteners (not shown in FIG. 3 ), where in this embodiment the fasteners are bolts. The bolts screw from underneath the mount, with respect to the orientation of the carrier and mount assembly 10 a shown in FIG. 3 , into the carrier. In alternative embodiments, any other suitable method of attaching the carrier to the mount may be used, for example welding.
[0102] During the step of screwing the bolts into the mount 24 a and carrier 12 a , the dowel maintains the carrier and mount in correct alignment in both the direction T and the direction R. In this embodiment, the dowel is removed from the assembly ready for normal use of the carrier and mount, i.e. mounted to an axle of a vehicle. However, in alternative embodiments the dowel may remain positioned in the conjoined channel 31 a during normal use.
[0103] Alternative embodiments are shown in FIGS. 4 to 6 . In these figures the carrier and mount assemblies 10 b , 10 c are viewed from below the assembly, with respect to the positioning of the embodiment shown in FIG. 3 . In these embodiments, the carrier 12 b , 12 c is positioned on a mount 24 b , 24 c . A planar surface of the carrier abuts a planar surface of the mount 24 b , 24 c (the planar surfaces are not visible in the Figures, but the positioning of the carrier and mount is similar to that shown in FIG. 3 ).
[0104] Four bores 36 b , 36 c (only two of which are visible) are formed in the mount 24 b , 24 c and the carrier 12 b , 12 c each for receiving a bolt to attach the carrier to the mount. Two of the bores 36 b , 36 c are positioned at one side of the assembly 10 b , 10 c and the other two bores (not shown in FIGS. 6 to 8 ) are spaced from said two bores to be positioned at an opposite side of the assembly 10 b , 10 c (i.e. an opposite side of an axle when the mount is attached thereto). The bores 36 b , 36 c longitudinally extend through the mount and carrier in the direction T. In this embodiment, the bores 36 b , 36 c extend entirely through the mount 24 b , 24 c and the carrier 12 b , 12 c . When the carrier 12 b , 12 c is positioned correctly with respect to the mount 24 b , 24 c the bore formed in the carrier is coaxially aligned with the bore formed in the mount.
[0105] Two location formations (only one is shown in the figures), in these embodiments a slot 30 b , 30 c , is formed in the mount 24 b , 24 c and the carrier 12 b , 12 c . In these embodiments, the slot 30 b , 30 c extends through both the mount 24 b , 24 c and the carrier 12 b , 12 c . Each slot 30 b , 30 c is coaxially aligned with one of the four bores 36 b , 36 c . In this embodiment, the bore 36 b , 36 c is threaded for engagement with a fastener, but there is no thread provided on the slot 30 b , 30 c.
[0106] In the embodiment shown in FIG. 4 the slot 30 b is substantially oval in shape and has a greater diameter than the bore 36 b in the direction R, such that the slot protrudes from the profile of the bore at each side of the bore in the direction R.
[0107] In the embodiment shown in FIGS. 5 and 6 , the slot 30 c is substantially rectangular in shape and has a greater length than the diameter of the bore 36 c in the direction R, such that the slot 30 c protrudes from the profile of the bore 36 c at each side of the bore in the direction R.
[0108] In alternative embodiments the slot may have any suitable shape that has a directional component in a direction parallel to the plane of the rotor.
[0109] Referring to FIG. 6 , to mount the carrier 12 c to the mount 24 c , a dowel 38 c is positioned in the slot 30 c . The dowel 38 c is a close fit to the slot 30 c . In this embodiment the dowel 38 c has a rectangular cross section, but in alternative embodiments the cross section of the dowel may be selected to correspond to the cross-section of the slot 30 c.
[0110] In this embodiment, the dowel 38 c is driven through the slot 30 c as the bolt (not shown in FIG. 6 ) is screwed into the bore 36 c , and exits through the opposite side of a slot 30 c formed by the slot in the mount and the slot in the carrier. However, in alternative embodiments the dowel 38 c may remain in a portion (e.g. an end portion) of the slot 30 c . In such embodiments, the slot 30 c may not extend entirely through the mount 24 c and the carrier 12 c , and instead extend entirely through one of the mount 24 c or carrier 12 c and only partially through one of the carrier 12 c or mount 24 c , respectively.
[0111] To attach the carrier to the mount, the carrier is positioned on the mount. The dowel is then positioned in the slot, to ensure correct alignment. A bolt is then screwed into the adjacent, slot-free bore. Subsequently, a bolt is screwed into the bore coaxial with the slot. As the bolt is tightened the dowel is driven through the slot. In alternative embodiments, the bolts may be tightened in a different order or simultaneously.
[0112] A further alternative embodiment of a carrier and mount assembly of a disc brake is indicated generally at 10 d in FIGS. 7 and 8 . A carrier 12 d is positioned on a mount 24 d . A planar surface of the carrier 12 d abuts a planar surface of the mount 24 d (the planar surfaces are not visible in FIGS. 7 and 8 , but the positioning of the mount with respect to the carrier is similar to that shown in FIG. 3 ).
[0113] A location formation, in this embodiment a hole 30 d extends entirely through the mount 24 d and a hole 32 d extends partially through the carrier 12 d . The holes 30 d , 32 d are linear holes positioned to have a longitudinal length in the direction T. In this embodiment a hole 30 d , 32 d is positioned on either side (i.e. each side of an axle when attached to an axle) of the mount and the carrier. In this embodiment the hole 30 d , 32 d is threaded, but in alternative embodiments the holes 30 d , 32 d do not have a threaded surface. When the carrier 12 d is correctly positioned on the mount 24 d the hole 30 d of the mount 24 d is coaxially aligned with the hole 32 d of the carrier 12 d . In alternative embodiments, the hole 30 d may extend partially through the mount 24 d and the hole 32 d may extend entirely through the carrier 12 d.
[0114] To mount the carrier 12 d to the mount 24 d , a locator, in this embodiment a bolt 38 d is screwed into each of the holes 30 d , 32 d . The bolt 38 d is a close fit to the holes 30 d , 32 d . The bolts or pins may be plain or doppler (also known as “quick release”) bolts or pins that utilize e.g. retractable ball bearing detents to releasably hold them in place, an example of a suitable pin is available from Speciality Fasteners and Components Limited of Totnes, Devon, UK, and is of the 420, 425, 620, 625, 13270 or 13275 series.
[0115] Four fasteners, in this embodiment bolts 40 d are then screwed into the mount 24 d and carrier 12 d to attach the carrier 12 d to the mount 24 d . In this embodiment, the bolt 38 d is then removed, but in alternative embodiments the bolt 38 d may remain in position during use. In such embodiments the bolt provided would be shorter in length than the bolt shown in FIGS. 7 and 8 .
[0116] A further embodiment is shown in FIGS. 9 and 10 . In this embodiment, a carrier 12 e is positioned on a mount 24 e , such that a planar surface of the carrier is seated on a planar surface of the mount 24 e (the positioning of the carrier, mount and planar surfaces is similar to that shown in FIG. 3 so will not be explained further here).
[0117] A location formation, in this embodiment a groove 30 e is positioned on two sides of the mount 24 e . The two said sides of the mount 24 e are orientated in a plane having axes parallel to an axis of rotation of a rotor of a disc brake and parallel to a direction tangential to a rotation of the rotor of a disc brake. A groove 32 e is positioned on two sides of the carrier.
[0118] The grooves 30 e and 32 e are linear grooves having a longitudinal length generally in a direction T tangential to a direction of rotation of a rotor of a disc brake. In this embodiment the grooves have a semi-circular cross section, but any appropriate cross section may be provided. In this embodiment the grooves are formed by milling.
[0119] To mount the carrier 12 e to the mount 24 e the groove 32 e of the carrier 12 e is positioned in coaxial alignment with the groove 30 e of the mount 24 e . A clamp having a locator component is positioned such that the locator component is positioned in the grooves 30 e , 32 e , and the carrier 12 e is clamped to the mount 24 e . Whilst the carrier 12 e is clamped to the mount 24 e , the carrier 12 e is attached to the mount 24 e , for example using fasteners such as bolts.
[0120] In this embodiment, the clamp applies the clamping force in a direction substantially perpendicular to the location formations and substantially perpendicular to an axis of rotation of the rotor, i.e. in the direction R.
[0121] A further embodiment is shown in FIGS. 11 to 14 . In this embodiment, a carrier 12 f is positioned on a mount 24 f , such that a planar surface of the carrier is seated on a planar surface of the mount 24 f (the positioning of the carrier, mount and planar surfaces is similar to that shown in FIG. 3 so will not be explained further here).
[0122] The mount 24 f includes four through holes 72 f , 74 f , 76 f , 78 f , and the carrier 12 f includes four through holes 80 f , 82 f , 84 f and 86 f . When the carrier 12 f is mounted to the mount 24 f the through holes of the mount are coaxial with the through holes of a carrier to receive a fastener (not shown in FIGS. 11 to 14 ). The four holes 72 f , 76 f , 74 f , 78 f of the mount are arranged so that two holes are on either side of a plane defined by an axis extending substantially parallel to a direction T of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The four holes of the carrier 80 f , 82 f , 84 f , 86 f are similarly arranged.
[0123] The holes 72 f , 74 f in the mount nearest an axis of rotation of a rotor (for use with the carrier) include a section 66 f , 30 f having an enlarged diameter, and the holes 80 f , 84 f in the carrier nearest the axis of rotation of the rotor included a section 68 f , 32 f having an enlarged diameter. The section of the carrier having the enlarged diameter is positioned adjacent the section of the mount having an enlarged diameter when the carrier is mounted to the mount. One or more of the narrower section of the holes 72 f , 74 f , 80 f , 82 f is threaded to mate with a fastener, which in this embodiment is a threaded bolt. The enlarged diameter section is free from thread.
[0124] A bush 68 f is positioned in the enlarged sections 68 f , 66 f on a leading side of the rotor (with respect to the usual direction of rotation of the rotor during use), and the bush 38 f is positioned in the enlarged sections 32 f , 30 f on the on a trailing side of the rotor (with respect to the usual direction of rotation of the rotor during use). The bushes 38 f , 68 f are split bushes include a chamfered end nearest the mount, i.e. a leading end during assembly. The split bushes are made from spring steel.
[0125] The bush 38 f forms a locator and the enlarged sections 30 f and 32 f form location formations. As such, the bush 38 f is formed to be a transitional fit to the enlarged sections 30 f and 32 f . In the present embodiment, the outer diameter of the bush 38 f is substantially equal to the outer diameter of the enlarged section 30 f , 32 f , but in alternative embodiments alternative transitional fits may be used, or the bush may have a relaxed outer diameter greater than the enlarged section 30 f , 32 f . A transitional fit may be a fit having a clearance of between 0 mm and 0.04 mm.
[0126] The bush 68 f is a transitional fit to the enlarged section 68 f of the carrier, but is a loose fit to the enlarged section 66 f of the mount 24 f . In this embodiment, there is a clearance between the bush 68 f and the enlarged section 66 f of the mount of approximately 0.07 mm, but in alternative embodiments the clearance may be greater or less than this. For example, a loose fit may refer to a fit having a clearance greater than 0.04 mm.
[0127] To mount the carrier 12 f to the mount 24 f , the bushes 38 f , 68 f are positioned in the enlarged sections 32 f , 68 f of the holes 82 f , 80 f . The carrier 12 f is then seated on the mount and the bushes 38 f , 68 f are positioned in the enlarged sections 30 f , 66 f of the holes 74 f , 72 f of the mount 24 f . The chamfer on the leading end of the bushes 38 f , 68 f eases insertion of the bushes into the enlarged sections of the mount. In the case of the bush 38 f , the chamfer on the leading end provides a lead in to the hole that eases compression of the split bush 38 f so that the bush can be more easily inserted into the enlarged section 30 f . When in the enlarged section 30 f , the split bush expands to have an outer diameter substantially equal to the outer diameter of the enlarged section 32 f of the carrier and/or of the enlarged section 30 f of the carrier.
[0128] Fasteners (not shown), in the present embodiment bolts, are then fastened through the holes 72 f , 74 f , 76 f , 78 f , 80 f 82 f , 84 f , 86 f in the carrier 12 f and mount 24 f to secure the carrier 12 f to the mount 24 f.
[0129] Advantageously, providing one bush that is a transitional or tight fit to the mount and one bush that is a loose fit to the mount eases assembly of the carrier and mount assembly 10 f because alignment of the carrier to the mount is simplified. Assembly can be further simplified when the bush 38 f is a transitional fit rather than the bush having a relaxed diameter greater than the diameter of the enlarged section.
[0130] A further embodiment is shown in FIGS. 15 to 17 . In this embodiment, a carrier 12 g is positioned on a mount 24 g , such that a planar surface of the carrier is seated on a planar surface of the mount 24 g (the positioning of the carrier, mount and planar surfaces is similar to that shown in FIG. 3 so will not be explained further here).
[0131] A location formation, in this embodiment a hole 30 g is positioned on one side of the mount 24 g , i.e. to one side of a plane defined by an axis extending substantially parallel to a direction T of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The hole 30 g extends partially through the mount 24 g . A location formation, in this embodiment a hole 32 g is positioned to be coaxial with hole 30 g of the mount 24 g , when the carrier 12 g is mounted to the mount 24 g.
[0132] A locator, in this embodiment a peg 38 g is positioned to extend into the holes 30 g and 32 g . The diameter of the peg 38 g , and the diameter of the hole 32 g in the carrier 12 g and the diameter of the hole 30 g in the mount 24 g is such that the peg 38 g is a transitional fit to the carrier and mount when positioned in the holes 30 g and 32 g . The peg 38 g is positioned on a trailing side of the rotor.
[0133] The peg 38 g is shown in more detail in FIG. 16 . The peg 38 g is substantially cylindrical. In the present embodiment, the peg 38 g has a knurled portion 60 g extending circumferentially around the peg. In the present embodiment, the knurled portion 60 g is positioned in the hole 32 g of the carrier 12 g , but in alternative embodiments the knurled portion 60 g may be positioned in the hole 30 g of the mount 24 g . The knurled portion 60 g and the hole 32 g of the carrier 12 g are dimensioned such that the knurled portion is an interference fit with the carrier 12 g when inserted in the hole 32 g . The peg 38 g includes a chamfered edge 62 g , 64 g at each axial extent thereof to ease positioning of the peg 38 g in the holes 30 g and 32 g.
[0134] A hole 66 g is formed in the mount 24 g and is positioned on the opposite side to the hole 30 g of a plane defined by an axis extending substantially parallel to a direction T of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. A hole 68 g is formed in the carrier 12 g and is positioned on an opposite side to the hole 32 g of a plane defined by an axis extending substantially parallel to a direction of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The holes 66 g and 68 g are dimensioned to be substantially the same size as the holes 30 g and 32 g . This means that either hole 30 g and 32 g or holes 66 g and 68 g can be used as location formations dependent upon which side of an axle the brake is mounted.
[0135] To mount the carrier 12 g to the mount 24 g , the peg 38 g is positioned in the hole of the 32 g of the carrier 12 g . The carrier 12 g is then seated on the mount and the peg 38 g is positioned in the hole 30 g of the mount 24 g . A fastener is then engaged with the threaded holes 78 g and 86 g positioned on an opposite side to the locator of a plane defined by an axis extending substantially parallel to a direction T of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake, and spaced furthest from said plane. A further fastener is then engaged with the threaded holes 74 g and 82 g on an opposite side to the locator of a plane defined by an axis extending substantially parallel to a direction T of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake, and spaced nearest to said plane. Then a fastener is engaged with the holes 80 g , 72 g , 74 g , 76 g on the same side as the locator of a plane defined by an axis extending substantially parallel to a direction T of insertion or removal of a friction element into or from the carrier, and an axis of rotation of a rotor of a disc brake. The described method of mounting the carrier to the mount has been found to be preferred for reducing taper pad wear. However, in alternative embodiments the fasteners may be fastened in an alternative order.
[0136] Advantageously, only providing a locator on one side of the carrier and mount assembly means that assembly is eased because there is no need to align two tight fitting locators. It has been found that the provision of only one locator is sufficient to correctly align the mount and carrier.
[0137] Advantageously all of the above described embodiments permit the carrier to be correctly positioned with respect to the mount in both a direction parallel to an axis of rotation of a rotor of a disc brake and in a plane parallel to a plane of a rotor of a disc brake. This means that when the disc brake having said mount and carrier are mounted to an axle of a vehicle, friction elements of the disc brake are substantially aligned with the rotor alleviating the problem of taper pad wear associated with disc brakes of the prior art.
[0138] In embodiments where the locator is removed, removal of the locator for normal use can reduce the weight of the disc brake in normal use.
[0139] Furthermore, the location formations are easily machined and formed.
[0140] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims. For example, the grooves or holes may have any appropriate cross section. Alternatively or additionally, the grooves may have a curved or stepped profile in a longitudinal direction.
[0141] In other embodiments, the mount may be a bracket secured by welding to an axle. In alternative embodiments, the mount may be part of a steering knuckle on a steered axle. The carrier is shown in this embodiment as not having a beam connecting the opposing sides 58 d of the rectangular receiving region, but in other embodiments such a beam may be provided.
[0142] In further alternative embodiments the locator is tapered. For example, the locator may be a dowel having tapered side walls. In some embodiments the dowel may be conical in shape. In such embodiments the location formations may also be tapered to accommodate the tapered locator. Advantageously, a taper can guide the locator into correct position in the location formation, which can guide the carrier into correct alignment with the mount. Although the present invention is primarily applicable to the mounting of carriers the applicant has recognized that the arrangements described in each of the embodiments may also be applicable to the mounting of calipers directly to mounts if such calipers are fixed (e.g. in conjunction with an axially sliding rotor).
[0143] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
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A carrier and mount assembly for a heavy vehicle disc brake. The assembly includes a carrier having a first location formation formed therein, a mount having a second location formation formed therein, wherein the second location formation is aligned with the first location formation, and wherein the carrier is mounted to the mount via two or more fasteners that extend in a direction substantially parallel to a direction of insertion or removal of a friction element into or from the carrier. There is also a locator positioned in the first and second location formations to enable the carrier and mount to be assembled in the correct position, wherein the locator is at least a close fit to the first and second location formations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process and apparatus plant for treating food products with ozone, aiming especially to bleach or decolorize, sanitize and deodorize the products thus treated.
2. Description of the Related Art
The literature relating to the ozone treatment of food products, in particular in the field of seafood (fish, crustacea, etc.) is known to be very extensive, and the reader may be referred for instance to documents FR-385,815, EP-294,502, FR-797,928 or else U.S. Pat. No. 4,559,902.
The use of ozone has thus been most particularly described in the case of the treatment of fish meat with the objective of sterilizing and deodorizing the meat, the treated fish meat coming from the recovery of the residues remaining on the bones and the head after filleting the fish, from fillet cutting scraps or even from actual fillets, the meat in question being eventually used as raw material for the manufacture of various products, such as surimi seafood products or other fish pastes, terrines or steaks.
A typical apparatus for the recovery and treatment of such fish meat for producing what those skilled in the art call "base surimi" seafood therefore comprises the following steps:
a step of separating the meat from the bones and heads (resulting in a first crude pulp, which is ready to use if necessary);
one or more operations of washing in water which optionally is slightly acidified, each washing operation being followed by a draining step (resulting in a washed pulp ready to use for some applications);
a refining step making it possible, by passing the material over a screen, to separate the proteins from the impurities (skin residues, etc.);
a final operation of mechanical water/meat separation carried out by centrifugal sedimentation or screw pressing, resulting in washed and refined fish meat ready to use (base surimi seafood).
The results of animal meat bleaching are commonly monitored by industrial sites by color measurements, called colorimetry, with readings of the brightness or whiteness, of the red/blue index and the yellow/green index, for example using the conventional L*/a*/b* system (CIE 1976 reference), the factor L being expressed in %.
For reasons of simplification, throughout the following text reference will be made, indiscriminately, to the L/a/b or L,a,b system or to their results, clearly keeping in mind that such references pertain to the abovementioned evaluation system.
The desired objectives, in terms of colorimetry, throughout the various washing operations carried out, are generally (depending on the product in question) an increase in the whiteness, a decrease in the redness and the absence of any change in yellows/browns or even a reduction in the latter.
The aforementioned document EP-A-284,502 describes in particular an apparatus for treating animal meat, consisting of a shell in which a hollow tube provided with a helical partition rotates, the whole assembly constituting a transverse screw, the free volume existing between the internal walls of the outer shell and the external helical partition of the hollow tube constituting a splashing chamber through which the meat/water mixture to be treated travels, the gas mixture containing ozone being injected into the hollow tube and diffusing outward into the splashing chamber through a plurality of diffusers located along the transfer screw.
The example provided by the document indicates a meat transfer rate inside the system of about 1 cm/s, which gives, taking into account the geometrical characteristics of the apparatus, a meat output of about 1 liter/minute.
Apart from the complexity of the system described in that document, work successfully carried out by the Applicants has allowed them to show that, because of the dynamics created in such an apparatus, the performance in terms of contact between the fish meat and the dissolved ozone is insufficient (no intimate mixing between the meat and the gas), leading to solid/gas demixing, but also, as a consequence, a lack of effectiveness over the entire diameter of the screw.
It may also be added that the use of gas injection pores for injecting the gas seems not to be very compatible with the cleanability requirements commonly practiced in the food industry (zones of the screw that are difficult to reach by a cleaning agent and potential blocking of the porous injectors with food material).
SUMMARY AND OBJECTS OF THE INVENTION
The present invention aims especially to remedy the abovementioned technical problems. It aims in particular to provide a process and apparatus for treating food products with ozone, making it possible:
to improve the productivity of ozone-treated food products;
to improve the quality of the transfer of ozone to the food product to be treated (it is known in practice that at the present time only 15 to 60%--depending on the plants available--of the ozone injected is actually transferred to the food product in question);
to avoid, nevertheless, the risk of impairing the product (by way of illustration, mention may be made here of the risk of impairing fish meat by turning it brown because of local overdosing);
to reduce overall the number of washing steps carried out in the user treatment chain;
to achieve higher quality in the product.
To do this, the process for treating a food product according to the invention, of the type which comprises making the product come into contact with ozone, the product having been premixed in order to form an initial solution which, in addition to the product, contains water, is characterized by the combined implementation of the following steps:
a) a supply of the initial solution containing the product is used;
b) a pumping device is used which allows the initial solution to be taken under pressure to a contactor;
c) an ozone-containing treatment gas mixture is injected into the initial solution, the injection taking place at one or simultaneously at several of the following locations:
between the initial supply and the pumping device;
between the pumping device and the contactor;
at one or more points in the contactor.
The "contactor" according to the invention is capable of allowing a sufficient time for contact between the product and the ozone injected into the solution in order to allow the required treatment, without the occurrence of liquid/gas demixing.
As will be clearly apparent to those skilled in the art, the "food products" intended by the present invention may be extremely varied, these comprising, by way of illustration, animal meat such as fish pulps but also other seafood such as mollusks or crustacea, butcher meats (beef, port, mutton, etc.), other food products such as the flesh of fruits or vegetables or purees thereof, or else products which may be termed "blood" products or other "blood-based" derivatives of the food industry. In particular, it is known that such blood derivatives are commonly recovered and reprocessed (especially for the purpose of separating the plasma from red proteinaceous bi-products) for the purpose of reusing them, not only for animal feed but also for human consumption, for example in the delicatessen field.
It will also be understood that ozone "treatment" according to the invention is intended, depending on the food product in question but also depending on the specification desired by each particular user site, for carrying out one or more of the following actions: bleaching or decoloration, disinfection, or else deoderization of the product.
Thus, by way of illustration, in order to exemplify the notion of "sufficient product/ozone contact time" according to the invention, we may consider the example of fish meat which is recovered from fish bones and heads resulting from filleting operations and is treated for the subsequent manufacture of "surimi"-type products; since the quality of this fish meat is evaluated, after treatment, according to the colorimetry method using the L/a/b system, a given user site will consider, for example, a sufficient contact time as being that to obtain a meat whiteness of up to at least 60% or even 70% on the L scale.
The "initial solution" according to the invention should be understood to mean a homogeneous or heterogeneous solid/liquid mixture.
As mentioned previously, the "initial solution" to be treated according to the invention may comprise one or more food products of extremely varied type.
Moreover, it will be understood that, depending on the application in question, the initial solution, which therefore includes the food product and water, may furthermore include additives, such as acids or bases, the role of which may especially be to adjust the pH of the medium in order to allow the water retention by the animal proteins to be controlled so as subsequently to make them easy to rinse and drain, or else antioxidants, such as ascorbic acid, or else stabilizers, such as EDTA, or even enzymes, or else polyphosphates or other sodium or calcium salts.
According to one of the ways of implementing the invention which is advantageous, the initial solution to be treated includes a compound of the peroxide family, such as hydrogen peroxide.
According to another of the ways of implementing the invention which is advantageous, the initial solution to be treated includes a compound of the organic-acid family, such as citric acid, acetic acid, succinic acid or lactic acid.
Without the Applicant being able at any moment to be bound by the explanation given below, it may be suggested that the presence of an organic acid in the initial solution facilitates, in the subsequent presence of ozone, the formation of very active peroxyacids (for example peracetic acid or else, by way of example, monopercitric or dipercitric acid).
According to another of the ways of implementing the invention which is advantageous, the initial solution to be treated includes a compound of the inorganic-acid family, such as nitric acid.
According to the invention, the "initial solution", which includes the product to be treated, entering the contactor is "under pressure", which should be understood to mean a pressure greater than atmospheric pressure, advantageously of between 0.1 and 10 bar relative but preferably of 0.2 to 2 bar relative.
The role of the contactor is to carry out what may be termed intimate mixing between the product to be treated and the ozone; it therefore makes it possible, on the one hand, to dissolve some or all of the ozone in the water and, on the other hand, to ensure that there is sufficient time for contact between the product and the dissolved ozone without the occurrence of demixing, this contact time having to be long enough to obtain the required level of treatment.
According to one of the embodiments of the invention, the contactor may be in the form of a tube reactor, such as one consisting of a pipe following a non-straight path, the tube reactor being provided with an inlet, allowing the solution coming from the pumping device to enter, and with an outlet capable of being connected downstream, for example to a device for storing the solution or else to an apparatus in which the solution may undergo an operation after the treatment.
By way of example of a "non-straight path", the pipe may advantageously have, over all or part of the portion lying between the inlet and outlet of the contactor, a structure consisting of one or more turns of circular or helical shape.
Again by way of illustration, the liquid/gas contactor according to the invention may also consist of a static mixer, such as those sold by the company SULZER.
According to one of the ways of implementing the invention, the product forming part of the composition of the initial solution is fish meat such as that obtained after an operation of separating the meat from the bones and/or the meat from the heads.
According to another of the ways of implementing the invention, the product forming part of the composition of the initial solution has, prior to said mixing, undergone one or more washing operations in an aqueous medium, this being, as required, slightly acidified (a draining step being inserted between two washing operations).
According to one of the ways of implementing the invention, after the treatment, the solution resulting from the treatment undergoes a draining step followed by one or more operations of washing the product in an aqueous medium, this being, if required, slightly acidified.
Moreover, the process according to the invention may have one or more of the following characteristics:
the ozone dose used for the treatment, expressed in grams of ozone per kilo of treated product, lies within the range going from 0.2 to 2 g/kg (taking into account not only the specificity of the treated product and of the desired treatment, but also, for example, the national legislation governing each user site).
The ozone dose will preferably lie within the range going from 0.3 to 1 g/kilo of product, and even more preferably within the range going from 0.4 to 0.9 g/kilo of treated product.
The ozone content in the treatment gas mixture lies within the range going from 10 to 200 g/m 3 , preferably lies within the range going from 20 to 120 g/m 3 and more preferably within the range going from 40 to 100 g/m 3 of mixture.
The composition of the initial solution treated satisfies a degree of dilution corresponding to 1 volume of product per 0.5 to 10 volumes of water, but preferably to a degree of dilution corresponding to 1 volume of product per 1 to 5 volumes of water and even more preferably to a degree of dilution corresponding to 1 volume of product per 3 to 5 volumes of water.
The invention also relates to an apparatus for treating a food product, allowing the product to be brought into contact with the ozone, the product having been premixed in order to form an initial solution which contains, in addition to the product, water, the plant comprising:
a) a supply of the initial solution to be treated;
b) a pumping device suitable for the initial solution to be taken under pressure to a contactor;
c) a supply of a treatment gas mixture which contains ozone;
d) means for injecting the treatment gas mixture into the solution, allowing the mixture to be injected at one or simultaneously at several of the following locations:
between the initial supply and the pumping device;
between the pumping device and the contactor;
at one or more points in the contactor.
Further features and advantages of the present invention will appear more clearly in the following description, given by way of illustration but in no way implying any limitation, together with the appended drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an apparatus for treating small quantities of food products with ozone according to the prior art;
FIG. 2 is a diagrammatic representation of another apparatus for treating food products with ozone according to the prior art, employing injection into the bottom of a mixer;
FIG. 3 is a diagrammatic representation of an apparatus for treating food products with ozone according to the invention, employing a contactor having a single series of circular turns;
FIG. 4 is a diagrammatic representation of another apparatus for treating food products with ozone according to the invention, employing three series of circular turns;
FIG. 5 shows results of measurements of L/a/b calorimetric parameters after ozone treatment according to the invention carried out on meat of fresh coalfish which has undergone, after the step of separating the meat from the bones, an operation of washing in an aqueous medium;
FIG. 6 gives other results of measurements of L/a/b calorimetric parameters after ozone treatment according to the invention carried out on meat of coalfish which has undergone, after the step of separating the meat from the bones, two successive operations of washing in an aqueous medium which come before and after an intermediate draining step (these tests have especially varied, in combination, the ozone dose, the parameter governing the presence/absence of citric acid in the solution, or the degree of dilution of the initial solution);
FIG. 7 shows other results of measuring calorimetric parameters of specimens of coalfish treated according to the invention, as a function of the degree of dilution of the initial solution;
FIG. 8 gives results of measuring calorimetric parameters on specimens of salmon treated with ozone according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate two diagrammatic representations of apparatuses forming part of the prior art, which give poor results that may be regarded as being insufficient in terms of the degree to which the injected ozone in the process is transferred into the food product to be treated.
By way of illustration, the apparatus in FIG. 1 is suitable for treating very small amounts of fish meat with ozone.
This figure shows a supply 1 of a gas mixture containing oxygen, for example air, or even of pure oxygen, this being sent to an ozonizer 2, the treatment gas mixture obtained on leaving the ozonizer 2, containing ozone (and also oxygen) and being analyzed (3) before being sent to the reactor 4 which contains the fish meat to be treated in aqueous solution.
The ozone-containing treatment gas mixture, coming from the analyzer 3, is injected into the aqueous solution containing the fish meat via a single injector, this being a simple tube pierced with holes or else, as is the case in FIG. 1, a porous disk 27 at the bottom of the reactor 4.
In the case of the embodiment shown in the context of this FIG. 1, the initial solution containing fish meat is not stirred in the reactor 4.
In order to determine and monitor the degree of transfer of ozone into the solution, the apparatus has a recovery line 26 going from the cloud of gas present in the reactor above the solution, allowing this cloud of gas to be analyzed in an ozone analyzer 6 (after the recovered gas has passed through a purging bottle 5), the gas after analysis then being discharged into the external atmosphere after passing over a detoxifying catalyst unit 7.
In terms of the degree of transfer of injected ozone into the solution (which degree is known to depend on many parameters, including the ozone content of the gas injected, the acidity of the solution to be treated, its degree of dilution or else the charge of product to be treated), such a plant does not easily allow degrees of transfer exceeding 15 to 20% of the ozone initially present in the starting gas mixture to be achieved.
As regards FIG. 2, this illustrates an apparatus allowing larger quantities of fish meat to be treated, the apparatus combining a mixer 8 of the type commonly used in the food industry.
The solution to be treated, which contains the fish meat and water, is therefore in this case regularly stirred within the mixer 8.
As previously, discussed this figure again shows the supply 1 of oxygen-containing gas mixture which feeds the ozonizer 2, the treatment gas mixture coming from the ozonizer 2 and containing ozone (and oxygen) being sent toward the bottom of the mixer 8.
In order to know the flow rate, the ozone-containing treatment gas mixture is in this case analyzed by means of a branch line 28 tapped off the output of the ozonizer 2.
Here too, the gas cloud in the top of the mixer 8 is analyzed by means of the line 26, which includes the purging bottle 5, the analyzer 6 and the detoxifying catalyst unit 7.
The results obtained using such an apparatus show that the ozone transfer is still insufficient, this reaching, depending on the situation, 20 to 60% of the ozone initially present in the starting gas mixture.
FIG. 3 illustrates an apparatus for treating a food product with ozone according to the invention, which incorporates the combination of a pumping device 10 and a contactor 11 consisting of a set of circular turns.
In this figure may again be seen the supply 1 of oxygen-containing gas mixture (for example air or even pure oxygen) which feeds an ozonizer 2, producing as its output the treatment gas mixture which contains ozone (and therefore also oxygen, or even oxygen and nitrogen), as well as the tap-off line 28 allowing the treatment gas mixture leaving the ozonizer 2 to be analyzed.
The initial solution, which apart from the product contains water, is, in the embodiment shown, stored in a buffer tank 14, the product to be treated coming in the figure from a apparatus 15 which, depending on the application in question, may represent a very variable point in the manufacturing chain of the user site. By way of illustration, considering the case of the treatment of fish meat, the following examples may be mentioned:
the apparatus 15 may represent a separator (often called a "pulper") which separates the fish meat from the bones or heads after a filleting operation;
the apparatus 15 may also represent a draining step, this taking place after the meat previously separated from the bones and the head has been washed a first time in an aqueous solution;
the apparatus 15 may also represent a draining step taking place after an operation of washing in an aqueous solution of the meat initially separated;
still by way of illustration, the apparatus 15 may represent a refiner, which separates the meat from impurities (pieces of skin, etc.) remaining after the washing operation.
The initial solution to be treated which is in the buffer tank 14 is sent to the pumping device 10 and then to the contactor 11, the ozone-containing treatment gas mixture in this case being injected into the line going from the buffer tank 14 to the pumping device 10.
The initial solution resulting from the treatment in the contactor 11 is, depending on the case, directed by an advantageous system of valves 17, 18 and 19 to a centrifugal separator 20, which allows separation of the water from the meat thus treated, or else to a degassing column 12, from which the solution is extracted in order to be fed back into the buffer tank 14 via the line 13.
It will be noted that the valve 19 allows the treated solution coming from the contactor 11 to be sampled for the purpose of analyzing it, for example by colorimetry.
Here too, the gas cloud in the column 12 is analyzed via the line 26.
Depending on the case, the product may thus undergo one or more treatment operations in the loop which contains the tank 14, the contactor 11 and the recycling line containing the degassing column 12.
As regards the line 16, this is a line for extracting the gas phase present in the tank 14, this being extremely useful in the case of complete or partial recirculation of the initial solution after ozone treatment in the contactor 11.
As indicated previously, the ozone-containing treatment gas mixture, such as coming from the ozonizer, is injected here at the point 9 in the line connecting the buffer tank 14 to the pumping device 10 but, as explained in detail above, the injection of the treatment gas mixture could also take place at one or several of the locations lying between the tank 14 and the pumping device 10, between the pumping device 10 and the contactor 11, or even at several points in the contactor 11.
It should be noted that although all the turns of the contactor 11 have been shown in this figure in a horizontal situation, the plane of the turns could also lie in another position, for example in the vertical plane.
FIG. 4 illustrates another apparatus for treating food products with ozone according to the invention, this being very similar to the apparatus previously described in the context of FIG. 3, the apparatus here differing by the structure of the contactor 11 which, in the embodiment shown, has a structure consisting of three series of circular turns.
Moreover, the apparatus allows the treatment gas mixture coming from the ozonizer 2 to be injected, via the system of valves 22, 23, 24 and 25, into one or more of the following locations: between the buffer tank 14 and the pumping device 10 (22), between the pumping device 10 and the first series of turns of the contactor 11 (23), between the two first series of turns (24) or else between the last two series of turns of the contactor 11 (25).
A device 21 for controlling the gas flow rate then allows one or more of the valves 22 to 25 to be selectively opened and allows the flow rate of mixture reaching each injection point to be controlled and regulated.
An apparatus such as that shown in FIGS. 3 and 4 has resulted in degrees of ozone transfer of at least 80%, or even of more than 90%.
An apparatus such as that described in the context of FIG. 4 was used to produce examples of implementation for the purpose of treating various categories of fish or poultry meat with ozone.
The results obtained after treatment are shown in the context of FIGS. 5 to 8 in terms of the variation in the calorimetric parameters L,a,b.
The colorimetric measurements were made using a MINOLTA CR210 system.
Each figure No. X shows the results of tests called XA, XB, XC, etc., respectively, the results of each test being given in terms of L,a,b colorimetry in the following manner: the L measurement (representative of the whiteness) is shown as a continuous line, the a measurement (representative of the red) is shown by a dashed line while the b measurement (representative of the yellow/brown) is represented by a dash-dot line.
By way of characteristics common to all the related tests below for ozone treatment according to the invention, the following elements may be noted:
the ozone-containing treatment atmospheres were obtained as output by an ozonizer of the OZONIA (type CF1) brand;
the initial solutions treated were conveyed to the contactor at a pressure of about 1 bar relative;
the particle size of the treated products (whether fish meat or poultry meat) was between 1 and 2 mm.
Moreover, it will be noted that, under the same conditions, slightly different results may be given in the appended figures, which will not be surprising to those skilled in the art who are familiar with the fact that the calorimetric results obtained after such treatment and washing operations are very sensitive to the initial state (especially in terms of freshness) of the batch of fish in question.
Let us now examine below the content of each of FIGS. 5 to 8.
FIG. 5 relates to the variation in the L/a/b calorimetric parameters for fresh coalfish meat, the 8 tests 5A to 5H having been respectively obtained under the following conditions:
the measurements for Test 5A were obtained on coalfish meat obtained directly from the operation of separating the meat from the bones (this coalfish meat therefore not having undergone any operation of washing in water and no operation of ozone treatment according to the invention);
the results of Test 5B were obtained on coalfish meat having undergone, after the operation of separating the meat from the bones, a step of washing in water slightly acidified with citric acid (citric acid content of the washing solution approximately 0.2% of the mass of meat diluted--this fish meat therefore underwent this step of washing in water but was not treated with ozone by the process according to the invention);
the results of Test 5C were obtained on a coalfish meat which was subjected, after the operation of separating the meat from the bones, two steps of washing in water slightly acidified with citric acid, a draining step having been interposed between the two washing operations (citric acid content of the washing solution approximately 0.2% of the mass of meat diluted--this fish meat therefore underwent these steps of washing in water but was not treated with ozone by the process according to the invention);
the results of Tests 5D to 5H were obtained after ozone treatment according to the invention on the fish meat coming from the washing step mentioned above in the context of Test 5B, the ozone dose used for the treatment being respectively, in the case of each of the 5 tests, 0.2 g/kg of fish meat; 0.5 g/kg; 0.9 g/kg; 1.8 g/kg; and in the case of the last test 2 g/kg of meat.
In all these cases, the initial solution containing the fish meat is water slightly acidified with citric acid (citric acid content about 0.2% of the mass of treated meat diluted) and corresponds to a degree of dilution of 1 volume of product per 3 volumes of water.
The ozone-containing treatment gas mixture was in all these cases injected at a single point located between the buffer tank 14 and the pumping device 10.
The results given in FIG. 5 illustrate, for this batch of coalfish, the spectacular effect obtained by the ozone treatment according to the invention (the optimum being without doubt obtained here in the case of an ozone dose of about 0.9 g/kg of meat), giving rise to a marked increase in the whiteness (L) but, above all, to a very marked reduction in redness (a) while at the same time maintaining the factor (b) almost unchanged.
Moreover, it will be noted that coalfish meat has the reputation, for those skilled in this art, of being very difficult to bleach, particularly depending on the initial state of freshness of the product.
Two conclusions may be drawn from this first series of results:
on the one hand, it is possible, in order for this user site to economize on the additional washing steps normally involved after the first washing of the meat in aqueous medium which follows the step of separating it from the bones. It may in fact be seen that the results obtained by virtue of the invention are much better than those obtained after a first washing (5B) and even after a second conventional washing (5C);
on the other hand, it may be noted that a final product is obtained which is qualitatively different (spectacularly better) than that obtained from a conventional chain: in fact an optimum value of about 4 is obtained for the "a" factor, a value never obtained by this user site using the conventional washing/draining procedures which did not allow this "a" factor to be reduced below 8 or 9, whatever the number of washing steps carried out.
These results are confirmed by those given in FIG. 6, which again illustrates comparative results obtained on fresh coalfish meat which has undergone, after the step of separating the meat from the bones, not one but two successive operations of washing in an aqueous medium (with a draining step in between). Moreover, the following parameters were studied here: depending on whether or not the initial solution to be treated contains citric acid, for various degrees of dilution of the meat in the water of the initial solution, as well as for increasing ozone doses in the treatment atmosphere.
The various Tests 6A to 6G relating to this FIG. 6 were then obtained under the following conditions:
here again, the results of Test 6A were obtained on the coalfish meat resulting directly from the step of separating the meat from the bones (the meat tested here was therefore subjected neither to the operation of washing in water nor of the ozone treatment according to the invention);
here again, the result of Test 6B was obtained on a coalfish meat which had undergone, after the operation of separating the meat from the bones, a step of washing in water slightly acidified with citric acid (citric acid content approximately 0.2% of the mass of treated meat diluted--the meat tested here by colorimetry therefore underwent a step of washing in water but no operation of ozone treatment according to the invention);
the results of Test 6C were obtained on a coalfish meat which had undergone not only a first operation of washing in slightly acidified water but subsequently, after draining, a second operation of washing in water slightly acidified with citric acid (the meat tested here therefore underwent two successive steps--before and after a draining operation--of washing in water, but no operation of ozone treatment according to the invention);
the results of Test 6D were obtained by treating coalfish meat, such as that resulting from the abovementioned second operation of washing in water in Test 6C, with ozone, the initial solution containing this fish meat in this case not containing citric acid, and being characterized by a degree of dilution corresponding to one volume of meat per three volumes of water.
The ozone dose applied in this Test 6D is equal to 0.8 g/kg of treated meat (for an ozone content of the treatment gas mixture of approximately 80 g/m 3 of gas), the ozone-containing treatment gas mixture being injected at a single point located between the buffer tank 14 and the pumping device 10.
The results of Tests 6E and 6F were also obtained by treating the fish meat resulting from the abovementioned two first steps of washing in water, in this case also for a degree of dilution of the meat in the water of the initial solution equal to one volume of meat per three volumes of solution, the initial solution in this case containing, in contrast, a low citric acid dose.
Here, Tests 6E and 6F have used an ozone dose of 0.87 g/kg of meat and 1.2 g/kg of treated meat respectively (in the case of an ozone content of the treatment gas mixture of approximately 80 g/m 3 of gas) the ozone-containing treatment gas mixture here again being injected at a single point located between the buffer tank 14 and the pumping device 10.
The results of Test 6G were obtained by treatment according to the invention of the coalfish meat coming from the first two abovementioned steps of washing in water, the initial solution, which here also contains a small concentration of citric acid, and corresponds, on the other hand, to a degree of dilution of 1 volume of meat per 2 volumes of water.
The ozone dose applied in the case of this Test 6G is 0.92 g/kilo of treated meat (for an ozone content of the treatment gas mixture of approximately 80 g/m 3 of gas), again injected at a single point located between the buffer tank 14 and the pumping device 10.
These results, which are given in the context of FIG. 6, therefore confirm the spectacular effect obtained both in terms of whiteness and in reduction in red (with an optimum lying in the region of 0.9 to 1.2 g/kg of meat in the case of this batch which had undergone beforehand two steps of washing in water.
It will be noted that although the second washing (6C) by itself improves the whiteness, it leaves the a factor almost unchanged and, in all cases, the overall results obtained by virtue of this second washing remain inferior to those obtained according to the invention in the context of Tests 6D, 6E, 6F.
FIG. 7 illustrates the calorimetric variation of coalfish meat specimens for varying degrees of dilution of the initial solution.
Tests 7A to 7E given in this FIG. 7 were then obtained under the following conditions:
here again, the results of Test 7A were obtained on a coalfish meat which had undergone, after the operation of separating the meat from the bones, a single step of washing in water slightly acidified with citric acid (the specimen tested in terms of colorimetry in the context of this Test 7A therefore underwent only an operation of washing in water but no operation of ozone treatment according to the invention);
The results of Tests 7B to 7E were obtained after ozone treatment according to the invention of specimens of coalfish meat as obtained after two operations of washing in water slightly acidified with citric acid (the fish meat specimens treated here according to the invention therefore result, after separation from the bones and from the head, from two successive operations of washing in water acidified with citric acid).
Tests 7B to 7E were all obtained under ozone dose conditions corresponding to 0.4 grams of ozone per kilo of treated meat (for an ozone content of the treatment gas mixture of approximately 40 g/m 3 of gas), the treatment atmosphere being always injected at a single point located between the buffer tank 14 and the pumping device 10.
The initial solution for these four tests was slightly acidified with citric acid (citric acid content approximately 0.2% of the mass of treated meat diluted).
The meat/water degree of dilution of the initial solution was, in each of the four cases, 1 volume of meat per 1 volume of water, 1 per 2, 1 per 3 and 1 per 5, respectively.
These results therefore show, for the batch of coalfish treated, results that are already excellent as from 0.4 g of ozone per kg of treated meat, with an optimum degree of dilution of the initial solution lying, as previously, approximately from 1 per 3 to 1 per 2.
As regards FIG. 8, this illustrates the variation in the calorimetric parameters on salmon specimens, the five tests shown in FIG. 8 having been obtained respectively under the following conditions:
The results of Test 8A were obtained on a salmon meat such as that obtained directly after the operation of separating the meat from the bones (the measured specimens here therefore had not undergone either an operation of washing in water or an operation of ozone treatment according to the invention);
The results of Test 8B were obtained on a salmon meat which had undergone, after the operation of separating the meat from the bones, an operation of washing in water (the specimens measured here therefore had been subjected to a single operation of washing in nonacidified water and no operation of ozone treatment according to the invention);
The results of Test 8C were obtained on a salmon meat which had undergone, after the operation of separating the meat from the bones, an operation of washing in water, this time slightly acidified with citric acid (the measured specimens here had therefore been subjected to a single operation of washing in acidified water and no operation of ozone treatment according to the invention);
The results of Tests 8D and 8E were obtained after ozone treatment according to the invention of salmon specimens such as those coming from the operation of washing in water mentioned previously in the case of Test 8B.
In both cases, the ozone dose applied was 0.6 grams of ozone per kilo of salmon meat treated and the degree of dilution of the initial solution was 1 per 2.
On the other hand, the initial solution treated, in the case of Test 8D, contained no citric acid, whereas the initial solution treated in the case of Test 8E was slightly acidified with citric acid.
It may firstly be observed from reading these results that the step of washing the salmon pulp in water alone (8B) already improves the whiteness L, but leaves the measurement of the redness, a, more or less unchanged, whereas the washing in acidified water of Test 8C further improves these results somewhat.
As regards the ozone treatment (8D) according to the invention, this makes it possible not only to improve the whiteness appearance but above all it allows a spectacular red reduction, while even improving here the b factor.
Finally, it will be noted that the addition of citric acid to the initial solution treated in the case of Test 8E improves the results obtained compared with Test 8D (i.e. compared with a nonacidified initial solution) essentially with respect to the L factor.
Apart from the tests given in the context of FIGS. 5 to 8, complementary tests were carried out in order to characterize the advantage, in certain cases, of using not a single injection of the treatment gas mixture upstream of the pumping device but a multiple injection.
By way of illustration, three types of whiting specimen were tested by colorimetry:
a first type of whiting meat specimen having undergone, after the operation of separating the meat from the bones, three steps of washing in water slightly acidified with citric acid--these steps being separated by a draining step--(the meat tested here by colorimetry has therefore undergone operations of washing in slightly acidified water but no operation of ozone treatment according to the invention);
a second type of whiting meat specimen having undergone, after the operation of separating the meat from the bones and then the three steps of washing in water slightly acidified with citric acid that was mentioned previously--these steps being separated by a draining step--, an ozone treatment according to the invention (the ozone dose used for the treatment is approximately 0.6 g/kg of fish meat and the initial solution containing the fish meat and water slightly acidified with citric acid corresponds to a degree of dilution of 1 per 5, the ozone-containing treatment gas mixture here being injected at a single point located between the buffer tank 14 and the pumping device 10);
a third type of whiting meat specimen having undergone, after the operation of separating the meat from the bones and then the three steps of washing in water slightly acidified with citric acid that was mentioned above--these steps being separated by a draining step--, an ozone treatment according to the invention (the ozone dose used for the treatment here is again approximately 0.6 g/kg of fish meat and the initial solution containing the fish meat and water slightly acidified with citric acid also corresponds here to a degree of dilution of 1 per 5, but, on the other hand, the ozone-containing treatment gas mixture here is injected simultaneously at two points (half the amount between the buffer tank 14 and the pumping device 10 via the valve 22 and the other half of the amount between the two first series of turns of the contactor via the valve 24).
The results obtained for these three types of whiting specimen confirm the effectiveness of the ozone treatment according to the invention as soon as there is one injection (whiteness greater than 60%, "a" factor approximately 3 and "b" factor approximately 12) but show that, by implementing a double injection of the mixture (22/24), although the "L" and "a" factors remain relatively unchanged compared with the single injection, the "b" factor in this case is markedly reduced by approximately 1/6th.
Without the Applicant being at any time bound by the explanation given above of the phenomena observed, it may be suggested that the results observed here in the context of multiple injection are without doubt linked to a marked reduction in the risk of excessive local oxidation of the color pigments of the meat treated.
It is known that poorly controlled oxidation of the product can give rise to a product of degraded (for example "burnt") appearance which cannot easily be used, the more so because the phenomenon is irreversible.
Moreover, tests were made in which the ozone-containing treatment mixture is injected at three points, via the valves 22, 23 and 24, into tuna meat, or even poultry meat.
These tests show spectacular results in terms of whiteness (L coefficients ranging from 64 to 70%) compared with the same meat treated by the user site according to its normal multiple washing/draining process, while still resulting in a red reduction of approximately 50% and leaving the b factor unchanged, or even reduced.
Moreover the tuna or poultry meat thus tested was evaluated, after treatment according to the invention, from a microbiological standpoint. The results obtained show a very significant gain from a health standpoint, with a total flora reduction having a value of one log or even up to 1.6 log. The poultry-meat handling industry is aware of the importance of this microbiological aspect and is constantly preoccupied with it.
The poultry or fish meat thus treated therefore exhibits a very attractive microbiological balance, and yet no denaturing of the functional properties of the proteins (for example, their gelling power) is observed.
Just as in the case of certain results commented upon previously in the case of fish meat, it should be emphasized that such a final poultry meat quality, especially in terms of the "a" factor, could not previously be obtained by the user site in question on its conventional treatment line, even after a very large number of washing/draining operations.
Although the present invention has been described with regard to particular embodiments, it is not thereby limited to them but, on the contrary, is capable of any modification and variation that might occur to those skilled in the art. Thus, although the invention has more particularly been exemplified in its performance and advantages in the case of fish and poultry meat, it will be understood in light of all the spectacular results described above that it will be applicable in many other fields of food products such as, for example, crustacea and other shell fish, or even butcher meat or fruit or vegetable pulp.
Likewise, although tube contactors, having one or more series of turns (for example circular or even helical turns), have more particularly been described throughout the foregoing, other types of contactors, for example those consisting of one or more static mixers in series (such as those sold by the company SULZER), may be envisaged, the key principle being in fact to achieve, by means of this device, what may be termed intimate mixing between the product to be treated and the ozone; it therefore makes it possible, on the one hand, to partially or completely dissolve the ozone in water and, on the other hand, to allow sufficient time for contact between the product and the dissolved ozone without any demixing occurring, this contact time having to be sufficient to obtain the required level of treatment.
It will therefore be understood that such a device makes it possible to create over the flow of initial solution passing through it a certain pressure drop, which it is possible to control, favoring exchange, while still ensuring that there are dynamic flow conditions avoiding dead volume regions or zero-velocity regions.
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A process for decolorizing, sanitizing and deodorizing a food product with ozone. The food product and water are mixed to form an initial solution and supplied to a pumping device to pressurize the solution. An ozone containing gas is injected into the initial solution in order to allow the treatment of the food product, without the occurrence of liquid/gas demixing. The apparatus includes a pumping device for pressurizing the solution, a contactor into which the pressurized solution is fed, a source of ozone, and at least one injector for injecting ozone into the solution.
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FIELD OF THE INVENTION
The invention relates to the art of moulding plastic parts with a resilient projection, such as connectors for corrugated tubing. More specifically, the invention relates to a solid core with a self-acting cam to facilitate the withdrawal of a solidified plastic part when the moulding cycle is completed. The invention also extends to an improved shaping mould, a moulding process and the product obtained thereby.
BACKGROUND OF THE INVENTION
Corrugated plastic conduit has started to replace electrical metallic conduit as a raceway for insulated conductors. In order to attach the electrical conduit to an enclosure or to connect the two ends of the conduit together, connectors are used which can either be glued or attached mechanically to a plastic corrugated conduit. Connectors of the type disclosed in applicant's U.S. Pat. No. 4,575,133, issued on Mar. 11, 1986, have found good market acceptance because of the ease of installation. Such a connector comprises a cavity receiving the extremity of the conduit, in which protrude one or more resilient tongues. Each tongue has an oblique camming surface facing the conduit entry end of the cavity and an opposite vertical locking face. In order to attach the connector to the conduit, the electrician has only to cut the conduit to the required length and insert it into the cavity of the connector. During the insertion operation, the ribs on the conduit cam the tongues out of the way allowing the conduit to slide easily past the tongues. Once fully inserted, the conduit is prevented from being pulled out of the connector by virtue of the interference created between the locking faces of the resilient tongues and a conduit corrugation.
The connectors for a corrugated conduit are normally manufactured by the well known injection moulding process. A typical set-up used for this purpose comprises a solid core positioned into the shaping mould to form the conduit receiving cavity of the connector. On the core is machined a recess to form the resilient tongue of the connector. At the end of the moulding cycle, after the part is cooled and the plastic material has solidified, the mould opens apart along the parting line and the connector is stripped of the core using an ejector assembly. A difficulty arises because of the interference created between the locking face of the tongue and the recess on the core. Should one try to eject the connector, the projection will likely be sheared off.
One method to solve this problem is to use a collapsible core of the type described in the U.S. Pat. Nos. 3,247,548 and 3,660,001. This core, although commercially produced, is expensive and difficult to maintain as the plastic material in fluid state may enter the core joints and cause a malfunction. In addition, the moulding operation is slowed down because of poor heat transfer between the cooling medium, the core and the moulded part.
Another approach is to use a two part connector of the type commercialized under the trademark KWIKON. One part of the connector contains the holding tongues and the other part is an outer ring pressed on the connector body. The tongues are very flexible in order to allow the removal from the core and by themselves they have no power to prevent the forceful removal of the conduit from the connector. The ring, when pressed on the connector, holds the tongues more rigidly in place. This type of connector operates well, however, the production methods are fairly costly as the two parts have to be moulded separately and then assembled.
OBJECT AND STATEMENT OF THE INVENTION
An object of the present invention is an improved process and apparatus for moulding a part of plastic material with a resilient projection such as a connector for corrugated conduit (hereinafter the term "connector" is intended to encompass a device used to join two sections of corrugated conduit as well as a device to couple a section of corrugated conduit to another component), allowing to easily free the solidified part from the moulding equipment.
In accordance with the invention, there is provided a process for moulding a part of plastic material with a resilient projection, comprising the steps of flowing fluid plastic material around a solid core provided with a recess to mould the resilient tongue, camming the tongue out of the core recess after the plastic material has solidified, and separating the solidified part from the core.
In a preferred embodiment, two cooperating cores are provided to carry out the molding process, namely a first core member comprising a tongue moulding recess with a camming surface therein, which assists to raise the resilient tongue out of the recess during the stripping operation, and a second core member which fits into the recess during the moulding cycle to form a barrier isolating the camming surface from the flow of plastic material at the mould filling stage, thus preventing the camming surface to alter the shape of the locking tongue. After the mass of plastic material has solidified, the second core member is removed from the recess and the stripping operation is carried out normally, the camming surface smoothly raising the tongue from the recess to prevent any damage. This embodiment is highly advantageous because it allows to mould the resilient tongue with a relatively wide locking face with no reduction in its holding power and, at the same time, allowing to greatly ease the stripping operation.
In a variant, no barrier element is used in association with the camming surface in the recess, whereby the camming surface leaves an impression on the resilient tongue. It will be appreciated that this arrangement provides two camming surfaces on the resilient tongue, namely a primary camming surface for retracting the tongue during the insertion of the corrugated conduit in the connector, and a secondary camming surface used to raise the tongue out of the core recess at the end of the moulding cycle.
In a first embodiment under the variant, the secondary camming surface is provided on the side of the tongue necessitating a rotational movement between the solidified connector and the core to cam the resilient tongue out of the core recess. This embodiment has a disadvantage in that it requires a more complex moulding equipment required to rotate the core contributing to an increase of the manufacturing costs of the mould.
In a second embodiment under the variant, the secondary camming surface is provided on the locking face of the resilient tongue. Although this embodiment allows to use a standard stripping technique, it reduces the effective area of the locking face, thus degrading the tongue holding power.
In addition to the core construction described above, the invention also extends to the mould assembly for carrying out the moulding process and to a connector for a corrugated conduit. It should also be appreciated that the invention is not limited to the manufacture of such connectors, but may also be applied for moulding other plastic parts having a resilient tongue.
In summary, the present invention comprises in a general aspect a process to produce a part of plastic material having a resilient tongue, the process comprising the steps of:
providing a core with a recess;
flowing plastic material in a fluid state around the core and within the recess, when solidifying the plastic material forms the part with the resilient tongue received in the recess;
camming the resilient tongue out of the core recess; and
separating the solidified part from the core.
Further, the invention comprehends a solid core for use with a shaping mould to produce a part of plastic material having a resilient tongue, the solid core comprising:
a body;
a recess in the body to receive a mass of plastic material in fluid state which solidifies to form the tongue;
a camming surface in the recess to raise the tongue out of the recess as a result of a sliding contact between the tongue and the core.
The invention also extends to a connector for connecting a section of a corrugated conduit to another component, the corrugated conduit being of the type having longitudinally spaced apart circular ribs, the coupling comprising:
a generally cylindrical body-portion having an extremity defining a conduit entry end;
a resilient finger mounted to the body-portion, the resilient finger including a locking tongue extending radially with respect to the body-portion for engagement with a rib of the section of corrugated conduit; and
two camming surfaces on the tongue to communicate a yielding motion to the resilient finger as a result of the sliding contact between the tongue and a member moving in either of two different directions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view of a conventional moulding assembly for manufacturing connectors for corrugated tubing;
FIG. 2 is a cross-sectional view taken along the symmetry axis of a conduit manufactured by the set-up depicted in FIG. 1;
FIG. 2A is a cross-sectional view taken along lines 2a--2a in the FIG. 2;
FIG. 2B is a cross-sectional view of the resilient tongue of the connector shown in FIG. 2;
FIG. 3 is a schematical view of a core assembly used in the moulding assembly of FIG. 1;
FIG. 3A is a sectional view taken along lines 3a--3a in FIG. 3;
FIG. 4 is a schematical view of a core assembly in accordance with the invention;
FIG. 4A is a cross-sectional view taken along lines 4a--4a in FIG. 4;
FIG. 4B is an enlarged view depicting the inter-relation between the cores shown schematically in FIG. 4;
FIG. 5 is a cross-sectional view of a core assembly for moulding a connector with two resilient projections for joining two corrugated conduits together;
FIG. 6 is a schematical view of a core assembly in accordance with a first variant;
FIG. 6A is a cross-sectional view taken along lines 6a--6a in FIG. 6;
FIG. 6B is an enlarged view of the core assembly shown in FIG. 6, depicting the camming action of the inner core to raise the resilient tonque of the connector from the recess on the inner core;
FIG. 7 is a schematical view of a core assembly in accordance with a second variant;
FIG. 7A is a cross-sectional view taken along lines 7a--7a in FIG. 7;
FIG. 7B is a cross-sectional view taken along lines 7b--7b in FIG. 7; and
FIG. 7C is a cross-sectional view of the resilient tongue of the connector manufactured by the set-up illustrated in FIG. 7.
Throughout the drawings, analogous elements are designated by the same reference numerals.
DESCRIPTION OF PREFERRED EMBODIMENTS
A conventional moulding assembly for producing connectors for corrugated tubing is schematically depicted in FIG. 1. The moulding assembly 10 comprises mould halves 12 and 14 moveable one with respect to the other and meeting along a parting line. A core assembly comprising an inner core 16 and an outer core 18 defines with the mould halves 12 and 14 a moulding cavity which is filled with plastic material through an injection channel 20. The outer core 18 is fixed on the mould half 12 and moves in unison therewith relatively to the inner core 16.
The assembly 10 also comprises an ejector assembly 19 for extracting the connector from the inner core 16 when the moulding cycle is completed.
The structure of the connector manufactured by the moulding assembly 10 is illustrated in greater detail in FIGS. 2, 2A, 2B, 3 and 3A. The connector 22 has a generally circular body defining a sleeve 23 for receiving an extremity of a section of corrugated tubing. A resilient finger 24 carries a tongue 26 projecting radially inwardly in the cavity of the sleeve 23. The tongue 26 comprises an oblique comming surface 28 facing towards the tubing entry end of the sleeve 23 and an opposite vertical flat locking surface 30.
To form the tongue 26, a recess 32 is machined on the inner core 16, comprising a slanted surface 34 forming the camming surface 28 of the tongue 26, and a vertical face 36 forming the locking surface 30.
The outer core 18 which comes in contact with the inner core 16 during the moulding cycle is used to free the resilient finger 24 on its three sides. The outer core 18 has a U-shaped structure in cross-section, including two parallel end flanges positioned at a right angle with respect to an intermediate flange. The intermediate flange and one of the end flanges are shown in FIG. 3 and are designated by the numerals 38 and 40 respectively. (See, also, FIG. 3A.)
A major drawback of the moulding assembly 10 resides in the interference created between the locking surface 30 of the tongue 26 and the conforming surface 36 in the recess 32. If one tries to strip the solidified connector from the inner core 16 using the ejector assembly 19, the tongue 26 will likely be sheared off.
To address this problem, the invention provides an improved core assembly illustrated in FIGS. 4 to 7C. A preferred embodiment of the core assembly is illustrated in FIGS. 4, 4A and 4B, comprising an inner cylindrical core 42 comprising a tongue forming recess 44, provided with a camming surface 46, and a slanted surface 34, extending generally in a circumferential direction with respect to the body of the core 42.
The outer core designated by the numeral 48 is also modified by comparison to the outer core 18 previously described. More particularly, the intermediate flange 50 of the outer core 48 comprises sidewalls 52 and 54 and a slanted bottom wall 56 mating with the camming surface 46 in the recess 44 of the inner core 42.
During the moulding cycle, the position of the cores 48 and 42 is as shown in FIG. 4B. It will be appreciated that the outer core 48 partially blocks off the recess 44 in the inner core 42, acting as a barrier element preventing the plastic material to flow in contact with the camming surface 46. It will further be appreciated that the cooperation of the cores 42 and 48 provides a tongue forming recess 44 which is identical in shape to the recess 32 used in conjunction with the prior art moulding assembly 10. Therefore, the arrangement shown in FIGS. 4, 4A and 4B will produce a locking tongue having a shape identical to the locking tongue 26 illustrated in FIG. 2B.
When the moulding cycle is completed, the outer core 48 is moved away from the inner core 42. When the ejector assembly pushes the solidified connector 22 out of the inner core 42, the camming surface 46 will smoothly raise the resilient tongue from the recess 44, allowing to free the connector 22 without any damage thereto.
The same inventive concept may be applied for the construction of a mould to produce a connector with two resilient tongues spaced apart along the centerline of the connector, as illustrated in FIG. 5. Such an arrangement comprises two cores 42 movable toward and away from each other along the common centerline 58, each core 42 being associated with an outer core 48 received into a respective tongue forming recess 44. The operation of the inner and the outer cores 48 and 42 is identical to the previously described embodiment.
A variant of the core assembly according to the invention is illustrated in FIGS. 6, 6A and 6B. The inner core designated by the reference 60 is provided with a tongue forming recess 61 comprising the oblique surface 34 and a camming surface 62 generally transversal to the oblique surface 34. Contrary to the previously described embodiment, the camming surface 62 is not shielded during the mould filling stage, therefore it will produce an impression on the locking tongue 66. The impression is in the form of a slant designated by the numeral 64.
In order to cam the resilient tongue 66 out of the recess 61, the inner core 60 must be rotated in a clockwise direction as shown by the arrow 68. When the inner core 60 has reached a predetermined angular position and the tongue 66 has been raised from the core 60, as shown in FIG. 6b, a standard ejector assembly may be used to slide the solidified connector off the inner core 60.
This embodiment allows to produce a connector with a locking tongue slightly narrower by comparison to the previous embodiment, yet effective for holding onto the corrugated tubing. However, the mould construction, because of the rotation of the inner core 60, is complicated, especially on multi-cavity moulds. This raises the original cost of the mould and also increases the mould maintenance costs.
A further variant of the invention is illustrated in FIGS. 7, 7A, 7B and 7C.
The cylindrical inner core 70 is provided with a tongue forming recess 72 in which is machined a narrow camming face 74 extending in a generally circumferential direction with respect to the body of the inner core 70. At the level of the camming face 74, the recess 72 is V-shaped in cross-section.
An outer core 76 used to free the resilient tongue on three sides enters the recess 72. The outer core 76 is provided with a notch 78 to clear the camming surface 74.
This arrangement produces a locking tongue 80 provided with a narrow camming face 82 on the locking face 84 of the tongue 80.
At the end of the moulding cycle, once the mass of plastic material has solidified, the mould is opened and the outer core 76 is removed. At that time, a standard ejector is able to strip the connector off the inner core 70 because, while the connector moves forward, the cooperating cam faces 74 and 82 in the recess 72 and on the tongue 80 respectively, raise the tongue out of the recess 72. This method if effective, however, it reduces the width of the locking surface of the tongue, therefore making it the least effective in holding onto the corrugated tubing among all embodiments described herein.
It should be understood that the above description of preferred embodiments of the invention should not be interpreted in any limiting manner since they may be refined in various ways without departing from the spirit of the invention. The scope of the invention is defined in the annexed claims.
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Apparatus for producing plastic parts with a resilient projection, such as connectors for corrugated tubing. The apparatus includes means for flowing plastic material on a core provided with a recess to mould the resilient projection, plural core cam surfaces to extract the resilient projection out of the recess, after the mass of plastic material is solidified and extract the solidified part from the core.
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BACKGROUND
1. Technical Field
The present disclosure relates to apparatus and methods for joining tissue portions and occluding vessels.
2. Background of Related Art
Ligation devices are used to join tissue portions and to occlude vessels. When tissue is held together by ligation devices that penetrate the body, the risk of foreign matter entering the site of a surgical wound is increased. To reduce the risk of infection, ligation devices can be coated with an antimicrobial or antibiotic material.
Once inserted into the body, ligation devices will remain in place unless they are either physically removed or dissolved in the body. The physical removal of non-resorbable ligation devices is a complicated surgical procedure typically involving the use of specially designed instruments.
SUMMARY
The present disclosure describes various methods and devices for tissue ligation and/or vessel occlusion. A device for delivering a localized antimicrobial solution or a biomechanical medium is described.
A ligation device may include a fastener member having a backspan and at least two prongs generally perpendicular to the backspan, a retainer portion having a connector and at least two columnar members attached to the connector, each columnar member having an aperture to receive and to retain the prongs, and a reservoir located within at least one of the columnar members. In another embodiment, the ligation device may include a fastener member having a backspan and legs generally perpendicular to the backspan with at least one leg housing a reservoir, and a retainer portion with a connector and at least two columnar members attached to the connector, each columnar member having an aperture to receive and retain the legs. The ligation device may also include a locking surface extending from at least one prong that is removably attached to a locking surface extending from at least one aperture.
Within the reservoir, a fluid such as an antimicrobial medium or solution may be stored. To facilitate storage of the fluid, a membrane seal may be positioned at the opening of the reservoir. Dispersion of the fluid may be facilitated by puncturing the membrane seal upon insertion of the fastener member into the retainer portion. The prongs of the fastener member may include a sharp distal tip to facilitate the opening of the membrane seal. A groove may be located on an inner surface of the retainer portion to facilitate dispersion of the fluid.
The various aspects of the present disclosure will be more readily understood from the following description when read in conjunction with the appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of description only, embodiments of the disclosure will be described with reference to the accompanying drawings, in which:
FIG. 1 is a side cross-sectional view showing a ligation device according to one embodiment of the present disclosure;
FIG. 2 is a side cross-sectional view of the ligation device of FIG. 1 showing a distal portion of an upper clip inserted into a cavity of a lower leg;
FIG. 3 is a side cross-sectional view of the ligation device of FIG. 2 showing the upper leg engaged in the cavity of the lower leg;
FIG. 4 is a front view of a ligation device according to an embodiment of the present disclosure; and
DETAILED DESCRIPTION
Particular embodiments of the present disclosure will be described herein with reference to the accompanying drawings. As shown in the drawings and as described throughout the following descriptions, and is traditional when referring to relative positioning on an object, the term “proximal” refers to the end of the apparatus that is closer to the user and the term “distal” refers to the end of the apparatus that is further from the user. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.
As seen in FIG. 1 , a ligation device 100 is shown including a fastener member 10 and a retainer portion 11 . The fastener member 10 includes a backspan 7 and at least two prongs or legs 18 that are generally perpendicular to the backspan 7 . The retainer portion 11 includes a connector 6 and at least two columnar members 5 configured and adapted to receive the prongs 18 of the fastener member 10 therein. The connector 6 is a generally U-shaped member. The connector 6 may be resilient or flexible. As such, the connector 6 allows the columnar members 5 to move towards each other and away from each other. Similarly, the backspan 7 may be resilient or flexible, thereby allowing the fastener member 10 to match the spacing between the columnar members 5 of the retainer portion 11 . At least one of the columnar members 5 is configured and adapted to store a fluid 15 within a reservoir 14 within the columnar member 6 . A membrane seal 16 may be positioned on or within the retainer portion 11 to facilitate storage of the fluid 15 within the reservoir 14 . The fluid 15 is released from the reservoir 14 upon insertion of the fastener member 10 into the retainer portion 11 . To facilitate release of the fluid 15 upon insertion of the fastener member 10 into the retainer portion 11 , prongs 18 may include a sharp distal tip 9 that is configured and adapted to puncture the membrane seal 16 . Dispersion of the fluid 15 may be facilitated by a groove 8 , as shown in FIG. 1 , positioned on the inner profile of the retainer portion 11 . In an alternative embodiment, the groove 8 may be positioned on the inner profile of the fastener member 10 .
As seen in FIGS. 1-3 , prong 18 is shown having a recess 12 that is engagable with a protrusion 13 within the columnar member 8 . Variations of this structure that are in the spirit of this disclosure will be apparent to those skilled in the art. For example, the prong 18 may have a protrusion that is engagable with a recess within the columnar member 8 . FIG. 3 shows the recess 12 engaged with the protrusion 13 , thereby locking the fastener member 10 to the retainer portion 11 . As shown in FIG. 3 , the recess 12 can be disengaged form the protrusion 13 by sliding the retainer portion 11 apart from the fastener member 10 in the direction of arrow A. To facilitate movement of the fastener member 10 and the retainer portion 11 apart from each other, the fastener member 10 and the retainer portion 11 may be formed from a material capable or small defections, e.g., an elastic and/or resilient material.
In an alternative embodiment, as seen in FIG. 4 , ligation device 200 includes an upper clip 20 and a lower clip 23 . The upper clip 20 includes a leg 20 a including a reservoir 24 that is sealed by a membrane 21 . The lower clip 23 includes a cutting element 22 extending from columnar member 23 a that is capable of puncturing the membrane 21 . Fluid 15 can be stored within the reservoir 24 .
Fluid 15 may be for example, but is not limited to being, an antiseptic or an antimicrobial solution, a biomechanical medium, and/or a wound treatment material. Examples of antimicrobial agents include but are not limited to β-Lactam agents, such as penicillins, and cephalosporins. By way of example only, the fluid 15 may include an antimicrobial hydrogel and may be in the form of a thixotropic, non-cytotoxic hydrogel. Preferably, the fluid 15 will facilitate healing by decreasing the likelihood of infection while not inhibiting healing of the surgical site.
The ligation devices disclosed herein may be made from natural or synthetic bioabsorbable materials, including but not limited to, alloys and polymers. Examples of families of bioabsorbable polymers include polymers having glycolic and ester linkages, including but not limited to polyesters, poly (amino acids), polyanhydrides, polyortho-esters, polyurethanes, polycarbonates, poly(dioxanone) (PDO), polyethylene glycol (hydrogels, polylactides (PLA), polyglycolides (PGA), polycaprolactone (PCL), and their copolymers. Some of the polymers, such as hydrogels, are hydrophilic. Others, such as PCL, are hydrophobic. The bioabsorbable polymers may be prepared by copolymerization of various monomers to modify and improve their properties as applications demand, e.g., poly (lactide-co-glycolide) copolymers. Because these polymers degrade by hydrolysis, the type of polymer and its physical form used in a particular application has an effect in defining the degradation period. Mechanical blending, as opposed to copolymerization, can also further enhance their properties.
Biocompatible, solid-solution strengthened alloys such as iron-based alloys, cobalt-based alloys and titanium-based alloys as well as refractory metals and refractory-based alloys may be utilized in the manufacture of such implantable medical devices. For example, traditional stainless steel alloys such as 316L, i.e., UNS S31603, may be utilized as an implantable, biocompatible device material. Depending upon the material selected, degradation of the material may be accelerated after exposing the material to radiation, including but not limited to gamma radiation.
Additionally, the ligation device 100 may also be made from materials impregnated or coated with substances known to have antimicrobial properties, such as silver or an antimicrobial medium. For example, oligodynamic metals including silver, copper, iron, zinc, bismuth, gold, aluminum, and other metals are known to have antimicrobial properties.
It will be understood by those skilled in the art that various modifications and changes in form and detail may be made therein without departing from the scope and spirit of the present disclosure. Accordingly, modifications such as those suggested above, but not limited thereto, are to be considered within the scope of the disclosure.
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A ligation device is disclosed that is capable of containing a fluid, e.g., a biomechanical medium or an antimicrobial solution. The ligation device comprises an upper clip and a lower clip, each having a locking feature that enables the upper clip and the lower clip to be movably attached to each other.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuing application, filed under 35 U.S.C. section 111(a), of International Application PCT/JP2004/016051, filed Oct. 28, 2004.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to an analysis technique for responses in a computer system.
BACKGROUND OF THE INVENTION
[0003] Along with development of a network service, a system to provide the service becomes complicated and large-scale. A lot of services have come to be provided by combining many servers. In such a system, it becomes very difficult to grasp how the utilization state of the resources of each server influences the response to the user.
[0004] Conventionally, following two methods are known in order to investigate what ratio the delay in each server of a system having plural servers occupies for a response time the user feels. Namely, (1) a special identification tag is attached to messages transmitted and received between servers, and the delay is measured by using the tag. (2) Messages transmitted and received between servers are captured by the packet capture to analyze such information.
[0005] However, the method (1) has to change the existing system and the service, and the introduction of this function is not easy. In addition, the method (2) requires an expensive equipment and a storage having a large capacity for the packet capture. Furthermore, in view of the security, the packet capture is not preferable.
[0006] In addition, US-2003/0236878-A1 discloses a technique to effectively evaluate, by the limited number of experiment times, the response capability of each application under various utilization states for one or plural applications operating on an information system. More specifically, when the load injection experiment corresponding to various utilization states of the application is carried out plural times, the quantity concerning the utilization state of the application, the quantity concerning the response capability of the application, the quantity concerning the utilization state of the hardware resource and the quantity of the response capability of the hardware resource are obtained, and by creating estimate equations describing the dependence relation between the quantities, the evaluation of the response capability of the application, by using the estimate equations, is enabled. However, this technique needs the “experiment”, and the analysis cannot be carried out while carrying out a regular processing.
SUMMARY OF THE INVENTION
[0007] Therefore, an object of this invention is to provide a technique for carrying out an analysis concerning the response of a computer system by using information that can be easily obtained from the computer system to be analyzed (hereinafter, to be monitored).
[0008] An analysis method according to this invention is an analysis method for carrying out an analysis for responses of a computer system including a plurality of servers. The analysis method includes: obtaining data concerning a CPU utilization ratio of each of the plurality of servers from the computer system, and storing the data concerning the CPU utilization ratio into a CPU utilization ratio storage; obtaining processing history data generated in the computer system, generating data of a request frequency by users of the computer system, and storing the data of the request frequency into a request frequency data storage; and estimating an average delay time in each server by using the CPU utilization ratio of each server, which is stored in the CPU utilization ratio storage, and the request frequency stored in the request frequency data storage, and storing the estimated average delay time into a server delay time storage.
[0009] Thus, because the processing is carried out by using data that can be easily obtained such as the CPU utilization ratio and the processing history data, the analysis processing can be carried out while reducing the introduction cost, and without causing any problem on the security.
[0010] Furthermore, the aforementioned estimating may include: estimating an average consumed CPU time per one request for each server by using the CPU utilization ratio of each server, which is stored in the CPU utilization ratio storage and the request frequency stored in the request frequency data storage, and storing the average consumed CPU time into a consumed CPU time storage; and estimating an average delay time in each server by using the average consumed CPU time per one request for each server, which is stored in the consumed CPU time storage, and the CPU utilization ratio of each server, which is stored in the CPU utilization ratio storage, and storing the average delay time in each server into a server delay time storage.
[0011] In addition, in the aforementioned estimating the average consumed CPU time, the average consumed CPU time per one request for each server may be estimated by carrying out a regression analysis by using the CPU utilization ratio of each server in a predesignated time range and the request frequency. Thus, by limiting to the predesignated time range, it is possible to exclude the time range when the request by the user is not processed so much and to improve the calculation accuracy.
[0012] Furthermore, in the aforementioned estimating the average delay time, a pertinent coefficient value representing a relation between the average consumed CPU time per one request for the server and the average delay time in the server may be read out by referring to a matrix storage storing said coefficient values for each predetermined unit of the CPU utilization ratio, which is an element to determine the coefficient value and for each number of CPUs, and the average delay time in the server may be calculated from the coefficient value and the average consumed CPU time per one request for the server. Because the coefficient value is a function of the CPU utilization ratio and the number of CPUs, the coefficient value can be calculated each time. However, because the calculation amount is actually increased, the coefficient values may be stored in the aforementioned matrix storage in order to enhance the processing speed.
[0013] In addition, this invention may further include, when the plurality of servers included in the computer system are categorized according to job types to be executed, estimating the average delay time for each category. For example, in a computer in which layers are defined, the average delay time may be calculated for each layer as the category. For example, it is to extract a problem for each job.
[0014] Furthermore, this invention may further include estimating an average delay time for the entire computer system by using the data stored in the server delay time storage, and storing the average delay time for the entire computer system into a system delay time storage.
[0015] In addition, this invention may further include: obtaining an average actual measurement value of a response time for a request by a user, and storing the average actual measurement value into an average actual measurement value storage; and estimating a delay time, which occurs in a portion other than the servers, by a difference between the average actual measurement value stored in the average actual measurement value storage and the average delay time of the entire computer system, which is stored in the system delay time storage. When the delay time, which occurs in the portion other than the server is shorter than the average delay time of the entire computer system, the estimation is improper because of any reasons, and it also becomes possible to detect such a case.
[0016] Furthermore, this invention may further include: calculating, for each category, a correlation coefficient between a total sum of the average consumed CPU times and the request frequency, determining a confidence degree of the average delay time for each category based on the correlation coefficient, and storing the confidence degree into a confidence degree data storage; and correcting the average delay time for each category based on the confidence degree of the average delay time for each category, which is stored in the confidence degree data storage, and storing the corrected average delay time into a storage device. For example, as for the average delay time whose confidence degree is high, the average delay time is used as it is, and as for the average delay time whose confidence degree is low, the average delay time is largely corrected.
[0017] Furthermore, the aforementioned correcting may include: sorting the average delay times in descending order of the confidence degree; accumulating the average delay times for each category in the descending order of the confidence degree, and identifying an order of the confidence degree at which the accumulated average delay time becomes the maximum value less than the delay actual measurement value; and correcting the delay time in a next order of the identified order of the confidence degree to a difference between the delay actual measurement value and a value obtained by accumulating the average delay times for each category in the descending order of the confidence degree up to the identified order of the confidence degree.
[0018] In addition, this invention may further include: when the request frequency is experimentally changed, for example, changing the CPU utilization ratio of each server according to the changed request frequency, and storing the changed CPU utilization ratio into the storage device; estimating the average delay time for each server by using the changed CPU utilization ratio for each server, which is stored in the storage device, and storing the estimated average delay time into the storage device; and outputting the average delay time for each server before and after the change, which are stored in the server delay time storage and the storage device, in a comparable manner. It is possible to know how the delay time is changed for the change of the request frequency.
[0019] In addition, this invention may further include: when the number of CPUs is experimentally changed, for example, changing the CPU utilization ratio of each server according to the changed number of CPUs, and storing the changed CPU utilization ratio into the storage device; estimating the average delay time in each server by using the changed CPU utilization ratio of each server, which is stored in the storage device, and the changed number of CPUs, and storing the estimated average delay time into the storage device; and outputting the average delay times of each server after and before the change, which are stored in the server delay time storage and the storage device, in a comparable manner. When increasing the number of CPUs, for example, it is possible to try how much the delay time is decreased, and the reasonability of the investment can be judged from the effect.
[0020] This invention may further include: when the number of servers is changed, calculating an average consumed CPU time per one request for each server according to the changed number of servers, and storing the calculated average consumed CPU time into the storage device; calculating a CPU utilization ratio for each server after the change by using the number of CPUs and the average consumed CPU time per one request for each server after the change, which is stored in the storage device, and storing the calculated CPU utilization ratio into the storage device; and estimating an average delay time for each server after the change by using the average consumed CPU time per one request for each server after the change, which is stored in the storage device, and the CPU utilization ratio for each server after the change, and storing the estimated average delay time into the storage device. When the number of servers is increased, for example, it is possible to try how much the delay time is decreased, and the reasonability of the investment can be judged from the effect.
[0021] Furthermore, this invention may further include estimating an average delay time for each category defined by classifying the plurality of servers in the computer system according to a job type to be executed by using the average delay time for each server after the change, which is stored in the storage device, and the changed number of servers, and storing the estimated average delay time into the storage device.
[0022] Incidentally, it is possible to create a program for causing a computer to execute the aforementioned analysis method. The program is stored into a storage medium or a storage device such as a flexible disk, a CD-ROM, a magneto-optical disk, a semiconductor memory, or a hard disk. In addition, the program may be distributed as digital signals over a network in some cases. Incidentally, data under processing is temporarily stored in the storage device such as a computer memory.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a diagram showing the principle of this invention;
[0024] FIG. 2 is a diagram showing the principle of this invention;
[0025] FIG. 3 is a diagram to explain the entire system in an embodiment of this invention;
[0026] FIG. 4A is a functional block diagram of a delay time analysis apparatus in the embodiment of this invention;
[0027] FIG. 4B is a functional block diagram of the delay time analysis apparatus in the embodiment of this invention;
[0028] FIG. 5 is a diagram showing a main processing flow of the embodiment of this invention;
[0029] FIG. 6 is a diagram showing an example of obtained data;
[0030] FIGS. 7A and 7B are diagrams to explain regression calculation;
[0031] FIG. 8 is a diagram to explain the reason to limit objects of the regression calculation to the business time;
[0032] FIG. 9 is a diagram showing a processing flow of a confidence degree calculation processing;
[0033] FIG. 10 is a diagram showing a processing flow of a correction processing of the delay time according to the confidence degree;
[0034] FIGS. 11A to 11 C are diagrams to explain a specific example of the correction processing of the delay time according to the confidence degree;
[0035] FIG. 12 is a diagram showing a processing flow of an estimation processing of the delay time change at the request frequency change;
[0036] FIG. 13 is a diagram showing a processing of an estimation processing of the delay time change at change of the number of CPUs;
[0037] FIG. 14 is a diagram showing a processing flow of an estimation processing of the delay time change at change of the number of servers;
[0038] FIG. 15 is a diagram showing an example of a processing result tabulation;
[0039] FIG. 16 is a diagram showing an example of a processing result graphing; and
[0040] FIG. 17 is a functional block diagram of a computer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0000] [Principle of this Invention]
[0000] A. Derivation of a Theoretical Value Xˆ (a Symbol That ˆ is Attached on the Top of X is Also Indicated as “Xˆ”) of an Average Delay Time in a Web System Model
[0000] A-1. Modeling of the Delay Time of a Single Server
[0041] First, by using FIG. 1 , it is considered that the average delay time in the single server S having plural CPUs is derived. The server S shown in FIG. 1 has C CPUs from CPU_ 1 to CPU_C, and requests input from the outside at the request frequency λ (req/sec) are input into a queue Sw and then processed by C CPUs. At this time, the utilization ratio of the CPU is represented as ρ(%). Then, from an analysis result of the M/M/s queue mode, an average stay time T (C, λ, ρ) is as follows:
T ( C , λ , ρ ) = F ( C , λ , ρ ) G ( C , ρ ) ( 1 ) F ( C , λ , ρ ) = C ρ λ ( 2 ) G ( C , ρ ) = ( C ( 1 - ρ C C ρ C C ! ∑ r = 0 C - 1 C r ρ r i ! + 1 ) ( 1 - ρ ) ) - 1 + 1 ( 3 )
[0042] From the expressions (1) to (3), the average stay time T(C, λ, ρ) in the server S satisfies the following relation. Incidentally, α represents a ratio of requests that reach the server S.
T ( C , α λ , ρ ) = 1 α T ( C , λ , ρ ) ( 4 )
A-2. Modeling of the Delay Time in the N-Th Server Layer
[0043] Here, by using a delay model in the single server, an average delay time of the requests in a specific single layer of plural layers is calculated. FIG. 2 shows a system model as an assumption. In the first layer, M 1 servers S (1,1) , S (1,2) , . . . S (1,M1) exist, in the second layer, M 2 servers S (2,1) , S (2,2) , . . . S (2,M2) exist, and further in the n-th layer, M N servers S (N,1) , S (N,2) , . . . s (n, MN) exist. In addition, α n represents a ratio of requests that reach the n-th layer, and when the requests are evenly assigned to servers in each layer, and the requests are input at the request frequency λ all (req/sec) to this system, λ all /M 1 requests are input into each server in the first layer, the requests leaving from the first layer is (1−α 2 )λ all , α 2 λ all /M 2 requests are input to each server of the second layer, the requests leaving from the second layer is (α 2 -α 3 ) λ all , the request leaving from the (N-1)-th layer is (α N-1 -α N ) λ 11 , α N λ all /M N requests are input to each server of the N-th layer, and the requests output from the N-th layer are α N λ all . Incidentally, 1≦n≦N, and 1≦m≦M n .
[0044] Different roles such as a Web server used as a front end for the user, an application server for dynamically processing the requests and the like are respectively assigned to each layer.
[0045] Then, when the request frequency to the n-th layer server S (n,m) is λ (n,m) , the average delay time in the server S (n,m) can be represented by T(C (n,m) , λ (n,m) , ρ (n,m) . In addition, when the total sum of the requests input into the n-th layer is α n λ all , and those are evenly assigned to M n servers, the following expressions are satisfied.
λ ( n , m ) = α n M n λ all
[0046] Because the requests are evenly assigned to each server, the average delay time W, of all the requests in the n-th layer is an average of the average delay times of all the servers existing in the n-th layer.
W n = 1 M n ∑ i = 1 M n T ( C ( n , i ) , λ ( n , i ) , ρ ( n , i ) ) ( 5 )
[0047] Here, W n is represented by using the expressions (1) to (4) as follows:
W n = 1 M n ∑ i = 1 M n T ( C ( n , i ) , λ ( n , i ) , ρ ( n , i ) ) = 1 M n ∑ i = 1 M n T ( C ( n , i ) , α n M n λ all , ρ ( n , i ) ) = 1 α n ∑ i = 1 M n T ( C ( n , i ) , λ all , ρ ( n , i ) ) . ( 6 )
[0048] Here, in order to simplify the notation, H n is defined as follows:
H n = ∑ i = 1 M n T ( C ( n , i ) , λ all , ρ ( n , i ) ) ( 7 )
A-3. Modeling of the Delay Time in the Entire System
[0049] Here, by using the delay model in each layer, the modeling of the delay time in the entire system is carried out. After the servers from the first layer to the n-th layer are used, the number R n of requests leaving from the system among all the requests is as follows:
R n =(α n -α n+1 )λ all (α 1 =1 , α N+1 =0) (8)
[0050] In addition, after the servers from the first layer to the n-th layer are used, the average delay L n of the requests leaving from the system is as follows:
L n = ∑ i = 1 n W i ( 9 )
[0051] In addition, the following relation is satisfied from the definition.
L n −L n−1 =W n (10)
[0052] Because the average delay time Xˆ per one request is represented by the product of the delay for requests leaving from the system after the servers from the first layer to the i-th layer are used and a ratio of the requests for all the requests, the average delay time Xˆ is represented as follows:
X ^ = 1 λ all ∑ i = 1 N R i L i = ∑ i = 1 N ( α i - α i + 1 ) L i = ( α 1 - α 2 ) L 1 + ( α 2 - α 3 ) L 2 + … + ( α N - α N + 1 ) L N = α 1 L 1 + α 2 ( L 2 - L 1 ) + … + α N ( L N - L N - 1 ) - α N + 1 L N = α 1 W 1 + α 2 W 2 + … + α N W N = ∑ n = 1 N H n ( 11 )
[0053] As the aforementioned results, when considering the average delay time of all the requests, H, represents the delay, which occurs in each layer, and it can be said that its total sum Xˆ represents the average delay time in the entire system for all the requests.
[0000] [Specific Processing]
[0054] FIG. 3 shows an outline of a system including a monitor target system 100 and a delay analysis apparatus 120 . The monitor target system 100 is connected with a network, and has an n-layer configuration (in FIG. 3 , two layers to simplify the explanation) as shown in FIG. 2 . In each layer, load distribution apparatuses 101 and 102 are provided, and the load distribution apparatuses almost evenly assign the requests to servers S (1,1) , S (1,2) and S (1,M1) and servers S (N,2) and S (N, MN) in each layer. For the servers of the first layers, a server log 111 a is provided, the log data generated when the processing for the request is carried out is stored. In addition, in each server, Central Processing Unit (CPU) utilization ratio obtaining units 112 a and 112 b are provided, and in this embodiment, the CPU utilization ratio is obtained by % unit. These CPU utilization ratio obtaining units 112 a and 112 b are general tools executed by a command such as sar, mpstat and iostat in UNIX (Registered Trade Mark) Operating System (OS) and the like, and a lot of recent OS have the similar function.
[0055] The delay analysis apparatus 120 is connected with the monitor target system 100 , and carries out a processing by using the log data stored in the server log 111 a and the CPU utilization ratio. Thus, different from the conventional arts, because there is no need to install any special mechanism into the monitor target system 100 , the introduction of the delay analysis apparatus 120 is easy, and furthermore, because all the packets processed in the monitor target system 100 do not have to be analyzed, there is no need to use a storage having a large capacity, and the problem on the security does not occurs easily. The delay analysis apparatus 120 is connected to an input/output unit 121 such as a display device, mouse, keyboard and the like.
[0056] FIGS. 4A and 4B show functional block diagrams of the delay analysis apparatus 120 . The delay analysis apparatus 120 has a request frequency obtaining unit 1201 , a CPU utilization ratio obtaining unit 1202 , a log data storage 1203 , a request frequency storage 1204 , a delay actual measurement value storage 1205 , a CPU utilization ratio storage 1206 , a system configuration data storage 1207 , a CPU time calculator 1208 , a CPU time storage 1209 , a performance prediction processor 1213 , a server delay time calculator 1210 , a G table storage 1211 , a server delay time storage 1214 , a layer delay time calculator 1215 , a layer delay time storage 1216 , a system delay time calculator 1217 , a system delay time storage 1218 , a remaining delay time calculator 1219 , a remaining delay time storage 1220 , a confidence degree calculator 1221 , a confidence degree storage 1222 , a delay time corrector 1223 , and a corrected delay time storage 1224 .
[0057] The request frequency obtaining unit 1201 receives the log data from the server log 111 a of the monitor target system 100 , and stores the log data into the log data storage 1203 , and processes the log data stored in the log data storage 1203 to calculate a request frequency (req/sec), and stores the request frequency into the request frequency storage 1204 . In addition, the request frequency obtaining unit 1201 processes the log data stored in the log data storage 1203 to calculate an average delay actual measurement value, and stores the average delay actual measurement value into the delay actual measurement value storage 1205 . The CPU utilization obtaining unit 1202 obtains data of a CPU utilization ratio from the CPU utilization ratio obtaining unit 112 of the monitor target system 100 r and stores the data into the CPU utilization ratio storage 1206 .
[0058] The CPU time calculator 1208 refers to the request frequency storage 1204 , the CPU utilization ratio storage 1206 and the system configuration data storage 1207 to calculate a consumed CPU time per one request, and stores the calculated data into the CPU time storage 1209 . The server delay time calculator 1210 refers to the CPU time storage 1209 , the G table storage 1211 and the CPU utilization ratio storage 1206 to calculate a delay time for each server, and stores the calculated data into the server delay time storage 1214 . Incidentally, the server delay time calculator 1210 may refer to the request frequency storage 1204 and the system configuration storage 1207 when the G table storage 1211 is not referenced.
[0059] Furthermore, the layer delay time calculator 1215 refers to the server delay time storage 1214 and the system configuration data storage 1207 to calculate the delay time for each layer, and stores the calculated data into the layer delay time storage 1216 . The system delay time calculator 1217 refers to the layer delay time storage 1216 and the system configuration data storage 1207 to calculate the delay time of the entire system, and stores the calculated data into the system delay time storage 1218 . The remaining delay time calculator 1219 refers to the delay actual measurement value storage 1205 and the system delay time storage 1218 to calculate a remaining delay time consumed by other apparatuses other than the servers, and stores the calculated data into the remaining delay time storage 1220 .
[0060] In addition, the confidence degree calculator 1221 refers to the remaining delay time storage 1220 , the system configuration data storage 1207 , the delay actual measurement value storage 1206 , the request frequency storage 1204 , the CPU utilization ratio storage 1206 and the layer delay time storage 1216 , and when the remaining delay time consumed by other apparatuses other than the servers is less than 0, the confidence degree calculator 1221 calculates a confidence degree for the delay time of each layer, and stores the calculated confidence degree data into the confidence degree storage 1222 . The delay time corrector 1223 refers to the layer delay time storage 1216 and the confidence degree storage 1222 to correct the delay time for each layer, and stores data of the corrected delay time into the corrected delay time storage 1224 .
[0061] The performance prediction processor 1213 carries out a processing by using the CPU utilization ratio storage 1206 , the system configuration data storage 1207 , the CPU time storage 1209 and the request frequency storage 1204 .
[0062] Incidentally, the input/output unit 121 can output the data in the respective storages in the delay analysis apparatus 120 to the display device or the like.
[0063] Next, the processing content of the system shown in FIGS. 3, 4A and 4 B will be explained with reference to FIGS. 5 to 16 . First, the request frequency obtaining unit 1201 obtains the log data from the server log 111 a of the monitor target system 100 , and stores the log data into the log data storage 1203 , and the CPU utilization ratio obtaining unit 1202 obtains data of the CPU utilization ratio from the CPU utilization ratio obtaining unit 112 of the monitor target system 100 , and stores the data of the CPU utilization ratio into the CPU utilization ratio storage 1206 ( FIG. 5 : step S 1 ).
[0064] An example of the log data stored in the log data storage 1203 is shown below.
[0000] “192.168.164.108−−[14/Sep/2004:12:27:50+0900] “GET/˜hoge/SSSS/SSSS — 20040816.pdfHTTP/1.1” 200 147067 “−” “Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322)” 0.053”(Windows is the Registered Trade Mark.)
[0065] This is an example of a log picked in a custom log format in the Apache Web server. Generally, the logs are stored as the server log 111 a under a directory /var/log/httpd/ of the Web server included in the monitor target system 100 or the like. This first section “192.168.164.108” represents an IP address of an access source client. The second and third sections are omitted. The fourth section “[14/Sep/2004:12:27:50+0900]” represents an access time. The fifth section “GET/˜hoge/SSSS/SSSS_ 20040817 .pdf HTTP/1.1” represents an access content. The sixth section “200” represents the status (here, normal). The seventh section “147067” represents the number of transmitted and received bytes. The eighth section “−” represents a URL path requested. The ninth section “Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322)” represents a browser used in the access source client. The tenth section “0.053” represents a time (sec) consumed to handle the request.
[0066] Next, the input/output unit 121 accepts setting inputs of a period to be analyzed and a business time range, and stores the setting inputs into a storage device such as a main memory (step S 3 ). The business time range means that a time range that the CPU time the server consumes for a processing other than requests from the users is few. By designating the business time range, it is possible to reduce an estimation error caused by consuming, by the server, the large CPU time when the request is few such as night.
[0067] Then, the request frequency obtaining unit 1201 reads out the log data in the designated period to be analyzed and the business time range from the log data storage 1203 , and counts the requests processed for each one hour, for example, and divides the count value by 3600 seconds (=one hour) to calculate the request frequency λ per one second (req/sec), and stores the request frequency into the request frequency storage 1204 . In addition, the request frequency obtaining unit 1201 adds the time consumed to handle all the requests every one hour, for example, and divides the added time by the number of requests to calculate an average delay actual measurement value, and stores the average delay actual measurement value into the delay actual measurement value storage 1205 . Furthermore, the CPU utilization ratio calculator 1208 calculates an average CPU utilization ratio ρ i (n,m) of each server S (n,m) for each one hour based on data of the CPU utilization ratio stored in the CPU utilization ratio storage 1206 , and stores the average CPU utilization ratio ρ i (n,m) into the CPU utilization ratio storage 1206 (step S 5 ). When one server has plural CPUs, an average CPU utilization ratio of the plural CPUs is calculated to obtain the CPU utilization ratio of the server. Incidentally, i in the average CPU utilization ratio ρ i (n,m) represents the i-th unit time (here, for each one hour). In addition, hereinafter, the word “average” may be omitted.
[0068] When the processing result until here is summarized, it is as shown in FIG. 6 , for example. In an example of FIG. 6 , for each time range, the unit time number i, the request frequency λ i (req/sec), the delay actual measurement value A i , the CPU utilization ratio ρ i (1,1) , ρ i (1,2) , ρ i (2,1) and ρ i (3,1) are shown.
[0069] Next, the CPU time calculator 1208 refers to the request frequency storage 1204 , the CPU utilization ratio storage 1206 and the system configuration data storage 1207 to calculate a consumed CPU time per one request, and stores the consumed CPU time into the CPU time storage 1209 (step S 7 ). In order to calculate the delay time, which occurs in each server, first, it is necessary to calculate how long the CPU time per one request is consumed in each server for the request frequency λ i (req/sec) input from the outside to the entire system. However, when the average consumed CPU time per one request is calculated, as a following expression, by simply dividing the product of the CPU utilization ratio ρ i (n,m) of the server S (n,m) in the unit time i and the number C (n,m) of CPUs by request frequency λ i , the following problem occurs.
F ( C ( n , m ) , λ i , ρ ( n , m ) i ) = C ( n , m ) ρ ( n , m ) i λ i ( 12 )
That is, in the server, generally, a few CPU time other than the processing of the request is consumed by the maintenance and the like of the system. When the request frequency is extremely small, because the ratio of such a CPU time becomes relatively large, the consumed CPU time per one request is estimated to be large and an error may be caused. That is, when, as shown in FIG. 7A , the horizontal axis represents the request frequency, and the vertical axis represents the CPU utilization ratio, and the expression (12) is interpreted as it is, the CPU utilization ratio must be “0” when there is no request. Then, when the inclination of the straight line connecting the origin with each measurement point is handled as the consumed CPU time per one request, the large difference occurs.
[0070] In order to solve this problem, it is supposed that the consumed CPU time per one request 1/μ (n,m) is represented as follows:
ρ ( n , m ) i C ( n , m ) = 1 μ ( n , m ) λ i + α ( n , m ) ( 13 )
Then, the consumed CPU time per one request 1/μ (n,m) is calculated by the regression analysis, and the approximation is carried out by the following expression.
F ( C ( n , m ) , λ i , ρ ( n , m ) i ) ≈ 1 μ ( n , m )
[0071] As shown in FIG. 7B , when the regression calculation is carried out, it is possible to calculate the inclination of the regression straight line connecting each measurement point as the consumed CPU time per one request, and obtain an actually closer value.
[0072] Incidentally, when the regression calculation is carried out, only data within the business time range designated by the user is used. In a case where all data in the period to be analyzed is used, when the batch processing or the like is carried out during the night in which the number of requests is small, and a phenomenon that a large CPU time is consumed occurs, a phenomenon that the CPU utilization ratio in a case where the number of requests is small is higher than one in a case where the number of requests is large occurs. Then, there is possibility that a large error in the estimation of the consumed CPU time per one request by using the regression calculation is caused. As shown in FIG. 8 , when measurement points by the night batch processing are represented by black circles, the black circles are plotted in an upper area of the vertical axis because the CPU utilization ratio becomes high though the request frequency is small. Therefore, when the regression calculation is carried out together with the measurement points (represented by white circles) for a daytime request processing, there is a case where the regression straight line like a solid line is obtained. On the other hand, when only the measurement points for the daytime request processing are used, a proper regression straight line whose inclination is positive like a dotted line is obtained. Therefore, the data should be narrowed to the business time range.
[0073] The aforementioned regression calculation is described in detail. When drawing a straight line like an expression (13) for data (CPU utilization ratio ρ (n,m) , the number C (n,m) of CPUs, which is the system configuration data, and the request frequency λ i ) in the business time range designated by the user among data in the period to be analyzed, the inclination 1/μ (n,m) and an intercept α (n,m) are calculated by the least-square method so that the deviation becomes the least, and stored into the CPU time storage 1209 . However, when α (n,m) becomes negative, because the possibility that the inclination is excessively estimated is high, the intercept is set to “0”, and 1/μ (n,m) is calculated by carrying out the regression analysis as the following straight line again.
ρ ( n , m ) i C ( n , m ) = 1 μ ( n , m ) λ i
[0074] In addition, when the inclination 1/μ (n,m) becomes negative, it is judged that the average delay time per one request in the server cannot be analyzed, and a code representing it cannot be analyzed is stored into the CPU time storage 1209 . When such a code is stored, the average delay time, which occurs in the layer in which the server is included, cannot be also analyzed.
[0075] Returning to the explanation of FIG. 5 , next, the server delay time calculator 1210 refers to the CPU utilization ratio storage 1206 , the system configuration data storage 1207 , the CPU time storage 1209 and the G table storage 1211 to calculate an average delay time per one request, which occurs in each server, and stores the calculated value into the server delay time storage 1214 (step S 9 ). In the i-th unit time, the average delay time T i (n,m) per one request, which occurs in each server, is given by the following expression.
T ( n , m ) i = T ( C ( n , m ) , λ i , ρ ( n , m ) i ) ≈ 1 μ ( n , m ) G ( C ( n , m ) , ρ ( n , m ) i ) ( 14 )
However, when ρ=0, G(C, 0)=1.
[0076] Here, although 1/μ (n,m) represents the consumed CPU time per one request, this is equal to the average delay time, which occurs when the load is 0%. Then, when the load is p, it means that the delay becomes G(C, ρ) times of a case when the load is 0%.
[0077] G(C, ρ) is calculated by the number of CPUs and the CPU utilization ratio of the server, as shown in the expression (3). However, because it takes relatively long time to calculate the expression (3) as it is, when the grain size of the analysis has been determined, it is possible to calculate G(C, ρ) in advance by changing the number of CPUs and the CPU utilization ratio of the server. For example, when the grain size of the analysis is enough in 1% unit for the CPU utilization ratio and the assumed number of CPUs per one server is equal to or less than 50, G(C, ρ) is calculated in advance in respective cases of the CPU utilization ratio from 0 to 99% (1% interval) and the number of CPUs in the server from 1 to 50, and they are stored in the G table storage 1211 as a matrix 100×50. Then, when obtaining the number of CPUs from the system configuration data storage 1207 , and obtaining the CPU utilization ratio from the CPU utilization ratio storage 1206 , a value of G(C, ρ) can be obtained from the G table storage 1211 .
[0078] Finally, the average delay time T i (n,m) per one request, which occurs in each server, (hereinafter, also called as the average delay time of each server, simply) is calculated according to the expression (14), and stored into the server delay time storage 1214 .
[0079] Next, the layer delay time calculator 1215 refers to the server delay time storage 1214 and the system configuration data storage 1207 to calculate the delay time L i n in each layer, and stores the delay time into the layer delay time storage 1216 (step S 11 ). The delay time L i n , in each layer is the sum of the average delay times of the servers for each layer. M n is obtained from the system configuration data storage 1207 .
L n i = ∑ m = 1 M n T ( n , m ) i
[0080] Then, the system delay time calculator 1217 refers to the layer delay time storage 1216 and the system configuration data storage 1207 to calculate the delay time D i of the entire system, and stores the delay time into the system delay time storage 1218 (step S 13 ). The delay time D i of the entire system is the sum of the delay times L i n in each layer n, and is represented as follows:
N is obtained from the system configuration data storage 1207 .
D i = ∑ n = 1 N L n i
[0081] After that, the remaining delay time calculator 1219 refers to the delay actual measurement value storage 1205 and the system delay time storage 1218 to calculate the delay time E i consumed in the portion other than the server, and stores the delay time into the remaining delay time storage 1220 (step S 15 ). The delay time E i is a difference between the delay time D i of the entire system and the delay actual measurement value A i , and is calculated as follows:
E i = { A i - D i ( A i ≥ D i ) 0 ( A i < D i )
[0082] A i <D i means that the aforementioned estimation result is not proper, and in such a case, E i =0 is set.
[0083] Then, in order to correct the delay time mainly in a case of E i =0, the confidence degree calculator 1221 refers to the remaining delay time storage 1220 , the layer delay time storage 1216 , the system configuration data storage 1207 , the request frequency storage 1204 , the CPU utilization ratio storage 1206 and the delay actual measurement value storage 1205 to carry out a calculation processing of the confidence degree of the average delay time for each layer, and stores the processing result into the confidence degree storage 1222 (step S 17 ). This processing is explained by using FIG. 9 . First, the confidence degree calculator 1221 calculates a correlation coefficient between the total sum ρ of the consumed CPU times of the n-th layer and the request frequency λ as an initial confidence degree R i n of the average delay time of each layer n, and stores the correlation coefficient into the confidence degree storage 1222 (step S 31 ). When a function to calculate the correlation coefficient is represented by “correl”, the confidence degree R i n is calculated according to the following expression.
R n i = correl ( ∑ m = 1 M n C ( n , m ) ρ ( n , m ) , λ ) ( 15 )
The first item of the correl function in the expression (15) is the total sum of the consumed CPU time in the n-th layer. Incidentally, because the correlation coefficient is also used for the later calculation, that is held for each layer.
[0084] Then, the confidence degree calculator 1221 judges whether or not the correlation coefficient R i n is negative (step S 33 ). In a case of the correlation coefficient <0, the confidence degree calculator 1221 sets the confidence degree R i n =0 (step S 37 ). This is because it is assumed that the positive correlation exists between the consumed CPU time and the request frequency, and there is no meaning for the negative correlation. On the other hand, in a case of the correlation coefficient ≧0, the confidence degree calculator 1221 judges whether or not the estimated delay time D i of the entire system is longer than the average delay actual measurement value A i (step S 35 ). When D i >A i is satisfied, the processing shifts to step S 37 because impossible estimation is made and the calculated delay time itself has the low confidence. That is, the confidence degree calculator 1221 sets the confidence degree R i n =0. On the other hand, in a case of D i ≦A i , the correlation coefficient calculated at the step S 31 is used as the confidence degree as it is.
[0085] Returning to the explanation of FIG. 5 , the delay time corrector 1223 refers to the confidence degree storage 1222 and the layer delay time storage 1216 to correct the delay time according to the confidence degree, and stores the corrected delay time into the corrected delay time storage 1224 (step S 19 ). Incidentally, in a case of A i ≧D i , this step is skipped. This processing will be explained by using FIG. 10 . First, the delay time corrector 1223 refers to the layer delay time storage 1215 and the confidence degree storage 1222 to sort the delay time of each layer in descending order of the confidence degree, and stores the sorting result into the correct delay time storage 1224 (step S 41 ). Incidentally, when plural layers whose confidence degree is “0” exist, the delay time is sorted in descending order of those correlation coefficients.
[0086] Then, the delay time corrector 1223 adds the delay time of the layer in descending order of the confidence degree according to the sorting result, and identifies an order B of the confidence degree at which the added value becomes the maximum value less than the average delay actual measurement value (step S 43 ). Here, it is assumed that P x =n represents the order of the confidence degree R i n of the n-th layer is the x-th from the top. Then, R i Px >R i Px+1 is always satisfied. Then, at the step S 43 , the maximum y satisfying the following expression is calculated. This is B.
A i > ∑ x = 1 y L P x i
[0087] It is unnecessary to correct the delay time of the layer whose confidence degree is one of 1st to B-th, which was calculated as described above. Therefore, the delay time corrector 1223 corrects the delay time of the layer whose confidence degree is the (B+1)-th as follows: (step S 45 ). That is, the estimated delay time L i Px+1 of the (P B+1 )-th layer is corrected, and the result is L′ i Px+1 . The correction result and the delay times of the layers, which is unnecessary to correct (layers whose confidence degree is one of 1st to B-th), are stored into the corrected delay time storage 1224 .
L P B + 1 ′ i = A i - ∑ x = 1 B L P x i
This expression represents that the delay time of the layer whose confidence degree is the (B+1)-th so that the delay actual measurement value is equal to the total sum of the delay times (estimated average value) from the top of the confidence degree to the (B+1)-th among the confidence degree of each layer.
[0088] In addition, the delay time corrector 1223 corrects the confidence degree of the layer whose confidence degree is the (B+1)-th as follows (step S 47 ). That is, the delay time corrector 1223 corrects the confidence degree R i Px+1 of the (P B+1 )-th layer, and uses the result as R′ i Px+1 . The correction result and the confidence degree data of the layers, which are unnecessary to correct, (layers whose confidence degree is one of 1st to B-th) is stored into the corrected delay time storage 1224 .
R B + 1 ′ i = L P B + 1 ′ i L P B + 1 i
This expression represents that the confidence degree is corrected so that the smaller the difference between the delay time before the correction and the delay time after the correction is, the higher the confidence degree becomes.
[0089] Furthermore, the delay time corrector 1223 corrects the delay time and the confidence degree of the layer whose confidence degree is the (B+2)-th or the subsequent as follows (step S 49 ). The correction result is stored into the corrected delay time storage 1224 .
L′ i Pn =0 ( n>B+ 1)
R′ i Pn =0 ( n>B+ 1)
[0090] A specific example of this correction processing will be explained by using FIGS. 11A to 11 C. First, FIG. 11A indicates the delay time estimation result and the actual measurement result. The first layer of the monitor target system 100 in this example is a Web server, and the second layer is an application server, and the third layer is a DB server. Here, the estimated delay time of the first layer is 150 m seconds, the correlation coefficient is 0.9, and the confidence degree is 0. The estimated delay time of the second layer is 60 m seconds, the correlation coefficient is 0.85, and the confidence degree is 0.85. The estimated delay time of the second layer is 30 m seconds, the correlation coefficient is 0.6, and the confidence degree is 0.6. Incidentally, the average delay actual measurement value is 100 m seconds.
[0091] Then, when the sorting is carried out at the step 541 , as shown in FIG. 11B , the layers are arranged in order of the second layer, the third layer and the first layer, the delay time of the entire system apparently exceeds the average delay actual measurement value, and the estimated delay time of the entire system exceeds on the way of the first layer.
[0092] Therefore, as shown in FIG. 11C , as for the second and third layers, the delay times and the confidence degrees are used as they are, and the estimated delay time of the first layer is decreased to the difference between the average delay actual measurement value and the sum of the delay times of the second and third layers, and 10 m seconds is obtained. Moreover, the confidence degree is also corrected to 0.06(=10/150).
[0093] By carrying out such a processing, the correction so as to fit the estimated value to the actual measurement value is carried out.
[0094] Returning to the explanation of FIG. 5 , the input/output unit 121 carries out an output processing (step S 21 ). Data the input/output unit 121 outputs includes (1) the estimated value T i (n,m) of the delay time, which occurs in each server, (2) the estimated value L i n of the delay time, which occurs in each layer, (3) the estimated value D i of the delay time, which occurs in the entire system, (4) the delay time E i of the portion other than the servers, (5) the confidence degree of the delay time of each layer and the like. In a case of the confidence degree, the value itself may be output, and the confidence degree R i n may be categorized into three levels described below, for example, and the categorization result may be output. That is, if R i n >0.7, the confidence degree is “high”, if 0.7≧R i n >0.3, the confidence degree is “middle”, and if 0.3≧R i n , the confidence degree is “low”.
[0095] The categorization of the confidence degree such as “high”, “middle” and “low”, which is described above, is based on values generally used for the judgment of the correlation strength in the correlation coefficient. That is, generally, when the absolute value of the correlation coefficient is equal to or greater than 0.7, it is judged that there is strong correlation between two parameters, when it is within a range from 0.3 to 0.7, it is judged that there is weak correlation, and when it is equal to or less than 0.3, it is judged that there is almost no correlation. This is because the square of the correlation coefficient is an explanatory rate of the variance. Then, when the correlation coefficient is 0.7, the explanatory rate is 0.49 (about 50%). That is, about a half of the variance of the dependent variable can be explained by the explanatory variable. In addition, when the correlation coefficient is 0.3, the explanatory rate is 0.1 (about 10%), and because the variance caused by the explanatory variable among the variance of the dependent variable is only about 10%, it is judged that there is almost no correlation between the explanatory variable and the dependent variable.
[0096] Similarly considering in this embodiment, when the correlation coefficient is equal to or greater than 0.7, there is enough correlation between the CPU utilization ratio and the request frequency, and because the consumed CPU time per one request can be appropriately estimated, it is considered that the confidence degree becomes high. In addition, when the guidance of the relation between this confidence degree and the prediction error is obtained from the experimental result in the experiment environment, the possibility is high in which the prediction error is about within ±50% in a case of the confidence degree “high”, the prediction error is about within ±100% in a case of the confidence degree “middle”, and the prediction error is greater than ±100% in a case of the confidence degree “low”. However, this result is mere guidance based on the experimental result after all, and the aforementioned accuracy (error range) is not secured.
[0097] By carrying out such a processing as described above, it becomes possible to calculate the delay times of each server, each layer and the entire system by using the elements, which already exist in the monitor target system 100 . In addition, it is possible to correct the delay time from the relation with the delay actual measurement value, and further present the confidence degree for the user.
[0098] Next, the performance prediction using the aforementioned model will be explained.
[0099] First, the estimation of the delay time change at the request frequency change will be explained by using FIG. 12 . Here, it is assumed that at a certain time i, the request frequency is λ, and the estimated average delay time will be calculated when the request frequency changes from λto λ′. Namely, λ′ is input from the input/output unit 121 , and the performance prediction processor 1213 of the delay analysis apparatus 120 accepts the input (step S 50 ). Then, the performance prediction processor 1213 changes the CPU utilization ratio ρ for all the servers S (n,m) according to the request frequency change, and stores the changed CPU utilization ratio into the CPU utilization ratio storage 1206 (step S 51 ). The CPU utilization ratio ρis changed to ρ′ described below. In addition, the server delay time calculator 1210 calculates the delay time T′ i (n,m) of each server after the change by using the CPU utilization ratio ρ′ after the change, and stores the calculated delay time into the server delay time storage 1214 (step S 53 ). The calculations at the steps S 51 and S 53 are as follows:
ρ ( n , m ) ′ i = ρ ( n , m ) i + λ ′ - λ μ ( n , m ) C ( n , m )
T ( n , m ) ′ i = 1 μ ( n , m ) G ( C ( n , m ) , ρ ( n , m ) ′ i )
[0100] Then, the layer delay time calculator 1215 calculates the delay time in each layer after the change by using the delay time T′ i (n,m) of each server after the change, which is stored in the server delay time storage 1214 , and stores the calculated delay time into the layer delay time storage 1216 (step S 55 ). Furthermore, the system delay time calculator 1217 calculates the delay time of the entire system after the change by using the delay time in each layer after the change, which is stored in the layer delay time storage 1216 , and stores the calculated delay time into the system delay time storage 1218 (step S 57 ).
[0101] After that, the input/output unit 121 outputs each delay time and the like before and after the change (step 559 ). Thus, the user can investigate the change of the delay time according the change of the request frequency.
[0102] Next, the performance prediction at the change of the number of CPUs will be explained by using FIG. 13 . Here, the number of CPUs of the server S (n,m) is changed from C (n,m) to C′ (n,m) . Therefore, the number C′ (n,m) of CPUs is input from the input/output unit 121 , and the performance prediction processor 1213 of the delay analysis apparatus 120 accepts the input (step S 61 ). Then, the performance prediction processor 1213 changes the CPU utilization ratio ρ according to the change of the number of CPUs, and stores the changed CPU utilization ratio into the CPU utilization ratio storage 1206 (step S 63 ). The CPU utilization ratio ρ is changed only for the server in which the number of CPUs is changed, as follows. In addition, the server delay time calculator 1210 calculates the delay time T′ i (n,m) of each server in which the number of CPUs is changed by using the CPU utilization ratio ρ′after the change, and stores the delay time into the server delay time storage 1214 (step S 65 ). The calculations at the steps S 63 and S 65 are as follows:
ρ ( n , m ) ′ i = C ( n , m ) C ( n , m ) ′ ρ ( n , m ) i
T ( n , m ) ′ i = 1 μ ( n , m ) G ( C ( n , m ) ′ , ρ ( n , m ) ′ i )
[0103] Then, the layer delay time calculator 1215 calculates the delay time in the layer relating to the change by using the delay time T′ i (n,m) of the server after the changer which is stored in the server delay time storage 1214 , and stores the calculated delay time into the layer delay time storage 1216 (step S 67 ). Furthermore, the system delay time calculator 1217 calculates the delay time of the entire system after the change by using the delay time in each layer, which is stored in the layer delay time storage 1216 , and stores the calculated delay time into the system delay time storage 1218 (step S 68 ).
[0104] After that, the input/output unit 121 outputs each delay time before and after the change (step S 69 ). Thus, the user can consider the change of the delay time according to the change of the number of CPUs. For example, by using this result, he or she investigates the effect in a case where the number of CPUs is increased.
[0105] Next, the performance prediction at the number of servers will be explained by using FIG. 14 . Here, it is assumed that the estimated delay time when the number of servers in the n-th layer is changed from M n to M′ n is calculated. Therefore, the number M′ n of servers in the n-th layer is input from the input/output unit 121 , and the performance prediction processor 1213 of the delay analysis apparatus 120 accepts the input (step S 71 ). Then, the performance prediction processor 1213 corrects the consumed CPU time per one request according to the change of the number of servers, and stores the corrected consumed CPU time into the CPU time storage 1209 (step S 73 ) The consumed CPU time 1/μ (n,m) per one request is changed to 1/μ′ (n,m) as follows. In addition, the performance prediction processor 1213 corrects the CPU utilization ratio ρ according to the correction of the consumed CPU time per one request, and stores the corrected CPU utilization ratio into the CPU utilization ratio storage 1206 (step S 75 ). The CPU utilization ratio ρ is changed to ρ′ as follows:
1 μ ( n , m ) ′ = M n M n ′ 1 μ ( n , m )
ρ ( n , m ) ′ i = 1 C ( n , m ) ( 1 μ ( n , m ) ′ λ i + α ( n , m ) ) ( 16 )
Incidentally, α (n,m) is an intercept obtained when 1/μ (n,m) is calculated, and is stored in the CPU time storage 1209 . Therefore, this value is used.
[0106] Next, the server delay time calculator 1210 calculates the server delay time after the change by using the CPU utilization ratio ρ′ after the change, which is stored in the CPU utilization ratio storage 1206 , and the consumed CPU time 1/μ′ (n,m) per one request after the change, which is stored in the CPU time storage 1209 , and stores the calculated server delay time into the server delay time storage 1214 (step S 77 ). The server delay time T′ i (n,m) after the change is represented as follows:
T ( n , m ) ′ i = 1 μ ( n , m ) ′ F ( C ( n , m ) , ρ ( n , m ) ′ i )
[0107] Then, the layer delay time calculator 1215 calculates the delay time in each layer by using the server delay time T′ i (n,m) after the change, which is stored in the server delay time storage 1214 , and stores the calculated delay time into the layer delay time storage 1216 (step S 79 ). Incidentally, also at this step, M i n from the performance prediction processor 1213 is used for the following calculation.
L n ′ i = M n ′ M n ∑ m = 1 M n T ( n , m ) ′ i
[0108] Incidentally, L′ i n is represented from the expression (16) as follows:
L n ′ i = M n ′ M n ∑ m = 1 M n T ( n , m ) ′ i = M n ′ M n ∑ m = 1 M n M n M n ′ 1 μ ( n , m ) G ( C ( n , m ) , ρ ( n , m ) ′ i ) = ∑ m = 1 M n 1 μ ( n , m ) G ( C ( n , m ) , ρ ( n , m ) ′ i )
[0109] Furthermore, the system delay time calculator 1217 calculates the delay time of the entire system after the change by using the delay time in each layer, which is stored in the layer delay time storage 1216 , and stores the calculated delay time into the system delay time storage 1218 (step S 81 ).
[0110] After that, the input/output unit 121 outputs each delay time before and after the change (step S 83 ). Thus, the user can consider the change of the delay time according to the change of the number of servers. For example, by using this result, he or she investigates the effect when the number of servers is increased.
[0111] Although the embodiment of this invention is described above, this invention is not limited to this. For example, the functional block diagrams shown in FIGS. 4A and 4B are mere examples, and the actual program configuration does not always correspond. As for the output processing, not only the values are displayed as they are, but also the table as shown in FIG. 15 (table to display, for each unit time i, the consumed CPU time per one request, the CPU utilization ratio, the average delay time for each server, the average delay time for each layer, the delay actual measurement value, the estimated delay time other than the server and the confidence degree of the delay time for each layer) and the graph as shown in FIG. 16 (graph in which the horizontal axis represents time, and the vertical axis represents the delay time, and which represents the time change of the delay times of the Web server (the first layer), the application server (the second layer), the DB server (the third layer) and other) may be generated and displayed. Incidentally, when watching the graph of FIG. 16 , it becomes possible to judge that during the normal time from 9 to 12 o'clock, the delay of the Web server almost occupies the half and more (portion A of FIG. 16 ), from 12 to 15 o'clock, because of the temporal load increase of the DB server, the response is extremely lowered (portion B of FIG. 16 ), since 18 o'clock, the delay time other than the server increases and any problem may occur (portion C of FIG. 16 ).
[0112] Incidentally, the aforementioned delay analysis apparatus 120 is a computer device as shown in FIG. 17 . That is, a memory 2501 (storage device), a CPU 2503 (processor), a hard disk drive (HDD) 2505 , a display controller 2507 connected to a display device 2509 , a drive device 2513 for a removal disk 2511 , an input device 2515 , and a communication controller 2517 for connection with a network are connected through a bus 2519 as shown in FIG. 28 . An operating system (OS) and an application program for carrying out the foregoing processing in the embodiment, are stored in the HDD 2505 , and when executed by the CPU 2503 , they are read out from the HDD 2505 to the memory 2501 . As the need arises, the CPU 2503 controls the display controller 2507 , the communication controller 2517 , and the drive device 2513 , and causes them to perform necessary operations. Besides, intermediate processing data is stored in the memory 2501 , and if necessary, it is stored in the HDD 2505 . In this embodiment of this invention, the application program to realize the aforementioned functions is stored in the removal disk 2511 and distributed, and then it is installed into the HDD 2505 from the drive device 2513 . It may be installed into the HDD 2505 via the network such as the Internet and the communication controller 2517 . In the computer as stated above, the hardware such as the CPU 2503 and the memory 2501 , the OS and the necessary application program are systematically cooperated with each other, so that various functions as described above in details are realized.
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An analysis method for carrying out an analysis for responses of a computer system including a plurality of servers, includes: obtaining data concerning a CPU utilization ratio of each of the plurality of servers from the computer system, and storing the data concerning the CPU utilization ratio into a CPU utilization ratio storage; obtaining processing history data generated in the computer system, generating data of a request frequency by users of the computer system, and storing the processing history data into a request frequency data storage; and estimating an average delay time in each server by using the CPU utilization ratio of each server, which is stored in the CPU utilization ratio storage, and the request frequency stored in the request frequency data storage, and storing the estimated average delay time into a server delay time storage. By carrying out such a processing, the analysis can be carried out without changing the computer system to be analyzed and any additional cost.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Continuation Application of PCT application Ser. No. PCT/JP03/03729, filed Mar. 26, 2003, which was published under PCT Article 21(2) in Japanese.
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2002-245811, filed Aug. 26, 2002, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a probe device and a method of controlling the device. More specifically, the present invention relates to a technique of carrying out: evaluation of local electrical conductivity of a nano-electric device surface; evaluation of an electrode of a nano-scale biological chip; research of a nano-region surface electrical conductivity; measurement of single molecule electrical conductivity; measurement of electrical conductivity of a single micro-crystal; evaluation of electrical conductivity of a domain critical interface; evaluation of electrical conductivity of a self-organized film; measurement of electrical conductivity of a single cell; and the like.
2. Description of the Related Art
Conventionally, evaluation of a local structure or electrical conductivity of a sample has been carried out by using a contact mode atomic force microscope which uses an electrically conducting probe (hereinafter, referred to as a “probe”). In this method, since the sample is scanned while the probe and the sample come into contact with each other, a certain degree of breakage occurs with both of the sample and probe. In a sample having a nano-scale structure, this breakage is fatal. Therefore, this contact mode measuring method cannot be applied to the sample having the nano-scale structure.
On the other hand, a tapping mode measurement is prevailingly known as a technique of evaluating only a structure. By means of this measuring method, measurement at a nano-scale resolution has been easily carried out. In this method, a cantilever is vibrated, thus making it possible to significantly reduce interaction between the probe and the sample, and further, measurement can be carried out without breaking the probe and the sample. In this method, however, a sufficient electrical contact cannot be obtained as compared with the contact mode measuring method. Therefore, this method cannot be used for evaluation of electrical conductivity in nano-scale.
Based on these restrictions, evaluation of local electrical conductivity in nano-scale is carried out as follows. First, structural measurement is carried out at a high resolution by using a tapping mode. Then, based on an image obtained by tapping mode measurement, the probe is moved to a predetermined position, the probe is pressed against the sample surface, and a current-voltage characteristic at the position is measured in a point contact condition. In this method, however, an intended position and a measuring point are shifted by a piezoelectric drift, thus making it impossible to precisely know a relationship between the structure and conductivity.
As has been described above, there has been no method for reliably measuring and evaluating local electrical conductivity of a sample having a nano-scale structure, and there has been a demand for an invention of a novel method.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a technique for reliably measuring and evaluating local electrical conductivity of a sample having a nano-scale structure.
In the gist of the invention, advantages of currently widely prevailing tapping mode measurement and a current-voltage measurement in accordance with a point contact mode are combined with each other so as to induce a common advantage of these measurements. A specific description will be given below.
Tapping mode measurement and point contact measurement are alternately carried out in advance while these measurements are switched every predetermined time in pixels specified by software. In this manner, while the damage of the sample and probe is minimized and a high resolution is maintained, an electrical contact sufficient to measurement of electrical characteristics can be obtained. As described above, according to the present invention, a local electrical characteristic of such a surface including an insulator can be imaged at a nano-scale resolution. In addition, an effect of drift can be avoided, thus making it possible to investigate a correlation between a nano-structure and an electrical characteristic without any error. Such a function is effective for evaluation of electrical characteristics of a nano-scale electronic device such as a semiconductor integrated circuit, a biological sensor, or a molecular device.
As has been described above, in order to switch the tapping mode and the point contact mode within a predetermined time, in the invention, an excitation signal or a feedback system of cantilever vibration and a Z-piezoelectric position etc. are dynamically controlled in synchronism with probe scanning. According to the invention, a topography, a current distribution image at an arbitrary voltage, and a current-voltage curve in 16,000 or more locations can be acquired altogether in a short time, about 10 minutes.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a diagram showing a general configuration of a probe device according to an embodiment of the present invention.
FIGS. 2A and 2B are views each showing a measuring method according to an embodiment of the invention, wherein FIG. 2A is a view showing an appearance in the case where a tapping mode is switched to a point contact mode; and FIG. 2B is a chart showing a signal waveform in the case where the tapping mode (period I in the figure) and the point contact mode (period II in the figure) are alternately switched to each other every predetermined period, thereby carrying out measurement.
FIGS. 3A to 3D are views each showing a measurement result in the case where the present invention is applied, wherein FIG. 3A shows a topography obtained by tapping mode measurement; FIG. 3B shows a topography obtained by point-contact current-imaging atomic force microscopy; FIG. 3C shows a current image measured at the same time when the measurement of FIG. 3B is carried out; and FIG. 3D is a view showing a relationship between a current and a distance from an electrode on a carbon nanotube.
FIGS. 4A and 4B are views each showing another measurement result in the case where the present invention is applied, wherein FIG. 4A shows a topography, and FIG. 4B shows a current image measured at the same time when the measurement of FIG. 4A is carried out.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing a general configuration of a probe device according to an embodiment of the present invention. In the following description, a probe device will be described by way of example of a generally used atomic force microscope.
As an atomic force microscope (AFM), there is utilized an AFM using an electrically conducting cantilever 10 having a probe 10 a . As shown in FIG. 1 , at a position opposed to the probe 10 a , a sample 20 is allocated on a piezoelectric scanner 21 so as to be movable on three axes. In addition, a desired voltage can be applied between the sample 20 and the probe 10 a by means of a bias 25 at which the applied voltage is variable.
The piezoelectric scanner 21 can move a sample along an X-Y plane by an X-Y scanning signal (not shown). In this manner, it becomes possible to measure a surface properties at a desired position. Further, the piezoelectric scanner 21 can be moved in a Z direction by inputting a Z signal from a feedback circuit 35 and a second signal generator 43 described later in detail.
A specific observing method will be described with reference to FIGS. 2A and 2B . FIG. 2A is a view showing an appearance in the case where a tapping mode is switched to a point contact mode. FIG. 2B is a chart showing a signal waveform in the case where the tapping mode (period I in the figure) and the point contact mode (period II in the figure) are alternately switched to each other every predetermined period (for example, every 10 ms to 20 ms, i.e., period of 20 ms to 40 ms), thereby carrying out measurement. In the invention, as shown in FIGS. 2A and 2B , the tapping mode and the point contact mode are alternately switched to each other every predetermined time, thereby carrying out sample measurement. First, a control in the tapping mode will be described here. In the following description, it is assumed that the tapping mode is entered when a feedback control signal is “High”, and the point contact mode is entered when the feedback control signal is “Low”.
A CPU 40 supplies a command to a CITS mode unit 41 so as to operate in the tapping mode. The CITS mode unit 41 supplies a command to a first signal generator 42 and a second signal generator 43 so as to make an operation in the tapping mode. At this time, the CPU 40 makes a control so that a feedback control becomes “High”. In this case, a superimpose signal and a bias voltage for feedback which controls the Z axis (distance between the probe and the sample) are set to zero.
The first signal generator 42 outputs an excitation signal for vibrating a cantilever 10 to a driver (for example, a piezoelectric element), although not shown, of the cantilever 10 during the tapping mode (( 2 ) of FIG. 2B ). In addition, at this time, the second signal generator 43 becomes “Low” (( 3 ) of FIG. 2B ). The vibration of the cantilever 10 is detected by a light source 30 and an optical detector 31 , and the detection result is outputted to a preamplifier 32 . A signal relating to the vibration of the cantilever 10 amplified by the preamplifier 32 is converted into a direct current signal by an RMS-DC converter 33 . Then, the converted signal is compared with a reference signal by an error amplifier 34 , and the related difference signal is outputted to a feedback circuit 35 . An output from the feedback circuit 35 is inputted to the piezoelectric scanner 21 and an A/D converter 36 . The A/D converter 36 converts the inputted signal into a digital signal, and outputs the converted digital signal as a sample surface image signal to the CPU 40 .
Further, the CPU 40 supplies a command for generating a reference signal to a reference signal generator 44 . In accordance with this command, the reference signal generator 44 outputs the reference signal to the error amplifier 34 .
After elapse of a predetermined time, the vibration of the cantilever 10 is stopped (that is, the tapping mode is stopped) without changing the position of the sample, the cantilever 10 is pushed against the sample 20 (that is, the sample is protruded in predetermined amounting the Z-axis direction, and the cantilever is set in a predetermined load state), and the probe 10 a and the sample 20 are brought into point contact with each other, thereby carrying out measurement in accordance with the point contact mode. At this time, an output from the first signal generator 42 is set to “0”, and the cantilever 10 does not vibrate. When the tapping mode measurement is switched to the point contact measurement, it is preferable that the vibration of the cantilever 10 be stopped speedily. Thus, a signal in a reversed phase from an excitation signal of the cantilever 10 is supplied from the first signal generator 42 , whereby the vibration of the cantilever 10 may be forcibly stopped. In addition, the second signal generator 43 outputs a DC signal so as to be superimposed on a feedback signal from the feedback circuit 35 , thereby specifying a distance between the sample 20 and the probe 10 a in this point contact mode. A relationship between the cantilever 10 and the sample 20 is set in such a state, a bias is swept between the probe 10 a and the sample 20 , and a current-voltage characteristic is measured. It is preferable that, when the tapping mode is switched to the point contact mode, a feedback loop is “frozen” and a value before freezing the feedback loop is stored, and that, when the point contact mode is switched to the tapping mode again, tapping mode measurement be restarted by using the stored value.
The above-described tapping mode measurement result and point contact mode measurement result are stored in a memory or a hard disk connected to the CPU 40 (or a recording medium such as an optical disk), although not shown. Then, these measurement results are outputted as a current image in a predetermined bias as required or in a real time, together with a topography. In this case, any recording medium may be used as long as it can store a measurement result without being limited to the memory or hard disk described above. In addition, the output of the results may be displayed on, for example, a display. Further, the output means includes printout to a printer or the like; writing on an external device; or transmission via a network.
The measurement results obtained by applying the present invention will be shown in FIGS. 3A to 3D . FIGS. 3A to 3D are views each showing a measurement result obtained by applying the invention to a single-layered carbon nanotube dispersed on a mica and connected to a gold metal electrode. FIG. 3A shows an AFM image obtained by general tapping mode measurement indicating a sample state. It is found that the gold metal electrode exists on the left, and the single-layered carbon nanotube extends therefrom. The technique according to the invention is applied to the vicinity of the center of this image. FIGS. 3B and 3C are views showing the measurement results, the views showing a topography and a current image measured at the same time by switching a mode, respectively. As shown in FIG. 3C , it is found that the current image is obtained at a high resolution.
From the topography of FIG. 3B , it is found that a current is reduced as the current image of FIG. 3C goes to the right side, despite a nanotube contrast is substantially constant. In addition, a portion which is not electrically connected cannot be seen in the current image. FIG. 3D is a view showing a result obtained by plotting the current distribution on the nanotube at point (A) to point (B) along the nanotube. According to FIG. 3D , the current distribution is obtained as graphically depicted, and a decreased current value can be traced as a distance from the gold metal electrode becomes long.
As has been described above, according to the measurement examples of FIGS. 3A to 3D , it is found that electrical characteristics of a nano-scale circuit configured on an insulation substrate can be evaluated.
FIGS. 4A and 4B are views each showing a measurement result in the case where the technique according to the invention is applied to a DNA network in atmosphere having a humidity of 60%. This DNA network is formed on a mica, and one end of the network is connected to the gold metal electrode. A current image has been monitored at a portion along the DNA network. Since the image does not appear as long as a bias current is speedily swept, the current image is obtained as a displaced current which exists at the position of a DNA chain rather than a direct current-like current which flows the DNA chain. This current image is monitored only when a humidity is high, and thus, it can be estimated that an ion or an electrical double layer are associated with this displacement.
Therefore, according to the measurement examples of FIGS. 4A and 4B , it is possible to measure an electrical characteristic at a nano-scale resolution with respect to a system which includes an electrochemical phenomenon such as a biological chip.
The present invention is not limited to the above-described embodiment of the invention. Of course, various modifications can occur without departing from the spirit of the invention.
According to the invention, a current distribution image in an arbitrary bias can be obtained at a nano-scale resolution at the same time when a topography is obtained. In addition, a current-voltage characteristic at each point can be acquired by a single scan. Further, the invention can be applied even if an insulator exists partly of a sample.
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A probe device including a cantilever. A probe is attached to the cantilever and is allocated to be opposed to a surface of a sample attached thereto. An apparatus is provided with the probe device, which is capable of carrying out measurement of the sample while switching at a predetermined period two operating modes, a tapping mode for measuring a surface structure of the sample while vibrating the cantilever and a point contact mode for measuring an electrical characteristic of the sample while bringing the probe into contact with the sample.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to refrigerant cycles incorporating a reheat coil, and wherein a tandem compressor arrangement is utilized. The resulting cycles provide an enhanced control over both humidity and temperature in the conditioned space as well as improve efficiency, reliability and life-cycle cost of the equipment.
[0002] Refrigerant cycles are utilized to change the temperature and humidity, or otherwise control the environment, in the conditioned space. In particular, a refrigerant cycle will typically include a compressor delivering a compressed refrigerant to a condenser, and from the condenser to an expansion device. The refrigerant exchanges heat with an outdoor environment at the condenser, and is expanded in the expansion device to a lower pressure and temperature. From the expansion device, the refrigerant continues to an evaporator at which it exchanges heat with an indoor environment, or an environment to be conditioned. From the evaporator, the refrigerant returns to the compressor.
[0003] The amount of cooling that can be supplied by a refrigerant cycle is known as its “capacity.” There are numerous ways to provide control over the capacity for a refrigerant cycle. One way is to substitute multiple compressors acting in tandem for a single compressor. In such an arrangement, the compressors can be selectively operated or shut down in response to an external heat load demand. Also, tandem compressors of different sizes can be utilized such that the various steps in the total capacity can be achieved. Moreover, both economized and conventional compressors can be employed in the tandem configuration, allowing for switching between various compressor modes of operation and further increasing a number of the unloading steps. Lastly, the tandem compressor configuration can be selectively chosen for any of the independent circuits of a multi-circuit system.
[0004] Another way of controlling an environment in the conditioned space with a refrigerant cycle is the incorporation of a reheat coil. Typically, a reheat coil is provided in the path of air that has been blown over the evaporator. The air passes over the reheat coil to regain heat from a refrigerant that is at a temperature hotter than the temperature of air leaving the evaporator. The reheat coil is thus able to raise the temperature of the air leaving the evaporator. Hence, the air dehumidified and overcooled in the evaporator is reheated back to a comfortable temperature level in the reheat coil. In other words, in the system with the reheat coil, the humidity in the conditioned space is mainly controlled by the evaporator and its temperature—by the reheat coil.
[0005] The reheat coil has not been utilized in a combination with tandem compressors, however. Thus, the refrigerant cycles with tandem compressors have not had as complete control over temperature and humidity levels as may be desired. It has to be noted that this invention is not related to any particular reheat concept or tandem compressor configuration, but rather provides advantages, that could not be obtained before for a refrigerant system, by integrating both design features in a single cycle. Consequently, a system with any reheat schematic or tandem compressor configuration can take advantages from the invention.
SUMMARY OF THE INVENTION
[0006] In disclosed embodiments of this invention, a refrigerant system incorporates tandem compressors. At least two compressors each separately compress a refrigerant and deliver it into the refrigerant cycle. A reheat coil is also incorporated into the refrigerant system, and receives air having passed over the evaporator to reheat the air to a desired temperature when required. In one embodiment, the reheat coil is positioned in the refrigerant cycle to receive a hot gas. Other embodiments may position the reheat coil such that it utilizes a two-phase mixture of refrigerant, or a liquid refrigerant. Also, some embodiments allow the condenser to be bypassed by at least a portion of refrigerant flow, when desired. Further, the reheat cycle may be incorporated in a system utilizing either economized or conventional tandem compressors, or a combination of both, in other embodiments. Also, in one embodiment, at least one compressor may be unloaded to provide even greater capacity control.
[0007] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a first embodiment of the present invention.
[0009] FIG. 2 shows a second embodiment of the present invention.
[0010] FIG. 3 shows a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] FIG. 1 shows a refrigerant system 20 incorporating a pair of conventional tandem compressors 22 and 24 for compressing a refrigerant and passing the refrigerant downstream to a discharge manifold 30 , and then to condenser 36 . The compressors 22 and 24 may or may not have oil equalization line 12 and pressure equalization line 13 connecting the two compressors for the purpose of potentially improving the oil management in the connected compressors. Furthermore, compressors 22 and 24 can be of different sizes and may have shutoff or check valves 32 located on the compressor discharge line to enhance system performance upon shutdown of one of the compressors.
[0012] A three-way valve 34 selectively communicates at least a portion of the refrigerant to a reheat coil 44 . The valve 34 can be of a fixed orifice design, a regulating device, or can be substituted by a pair of solenoid valves. The refrigerant passes to a line 39 downstream of the reheat coil 44 through the check valve 46 , and rejoins the main refrigerant circuit at point 41 . Point 41 is upstream of condenser 36 . A main expansion device 38 , and an evaporator 40 are downstream of condenser 36 . Thus, refrigerant flows from the main expansion device 38 to the evaporator 40 , and then is returned to a suction manifold 26 , communicating through lines 28 to the suction port of each compressor 22 and 24 .
[0013] As is known, an indoor airflow 45 is driven over the evaporator 40 . As the air is cooled, the moisture content in the air stream is typically reduced, and, thus, the air supplied to the conditioned space has been dehumidified. If the temperature of air leaving the evaporator is lower than desired for the conditioned space, reheat coil 44 is utilized to reheat the air stream 45 to a required temperature level. As shown, air moving device 42 drives air stream 45 .
[0014] A control 19 for the refrigerant system 20 can operate the system to achieve various goals. In particular, one or both of the compressors 22 and 24 can be operated by controlling motors and closing shut-off valves 32 . Thus, the total amount of refrigerant being compressed and circulated throughout the refrigerant system can be controlled to achieve different capacity levels. Moreover, the three-way valve 34 may be controlled to direct at least a portion of refrigerant into the reheat coil 44 . Under many conditions it is not necessary to circulate refrigerant through the reheat coil. However, when it is desirable to achieve dehumidification to the extent that the air stream 45 would otherwise be cooled below the desired temperature, then circulating at least some refrigerant through the reheat coil 44 will allow the temperature of the air stream 45 to be raised to a comfortable level, while the moisture content had been reduced in the evaporator 40 . Thus, system sensible and latent capacity can be controlled in both cooling and dehumidification modes of operation to a much greater extent by selectively operating tandem compressors 22 and 24 .
[0015] As known, each of the tandem compressors 22 and 24 may be provided with a means of unloading, where part of the compressed refrigerant is by-passed back to the compressor suction (internal or external of compressor) and allow for additional steps in capacity control. This is particularly true when the capacities of the two compressors are selected to be different. Control 19 can close either shut-off valve 32 or leave both valves open (in conjunction to controlling the respective compressor motor shutdowns) to achieve several capacity steps. Further, at each capacity step, there is greater humidification control by selectively opening valve 34 , utilizing the reheat coil 44 .
[0016] Also, more than two compressors can be configured into a tandem arrangement offering multiple steps of unloading and control over various system operation parameters.
[0017] FIG. 2 shows another embodiment 50 . There are tandem economized compressors 22 and 24 delivering refrigerant to a discharge manifold 30 . Downstream of this manifold is a condenser 36 , a main expansion device 38 , and an evaporator 40 . An air moving device 42 blows air over evaporator 40 . Refrigerant is returned to a suction manifold 26 , and through lines 28 back to the individual suction ports of compressors 22 and 24 . Compressors 22 and 24 also have intermediate pressure, or economizer, ports communicating through lines 61 and economizer manifold 57 to the refrigerant system. Economizer lines 61 may incorporate shutoff valves 59 in order to switch between economizer and conventional modes of operation for each individual compressor. Bypass valves 51 allow the compressors to be unloaded, such that either or both of the compressors can be operated at a reduced capacity.
[0018] An economizer loop is incorporated in the refrigerant system 50 downstream of the condenser 36 . In the economizer cycle, an economizer heat exchanger 52 receives a tapped refrigerant flow 54 , and a main refrigerant flow 55 . As can be seen, the tapped refrigerant flow in this embodiment is tapped from the main refrigerant flow 55 downstream of condenser 36 . The tapped refrigerant passes through an economizer expansion device 56 . After having passed through the economizer expansion device 56 , the tapped refrigerant is at a lower pressure and temperature, and is able to cool the main refrigerant flow 55 in the economizer heat exchanger 52 . In a preferred embodiment, the flow of the tapped refrigerant through the economizer heat exchanger 52 is preferably in the reverse direction to that illustrated (that is in the opposed direction to the flow 55 ). However, the flows are illustrated in the same direction to simplify the drawing.
[0019] The tapped refrigerant is typically returned as a vapor to be injected into the compressors 22 and 24 through the economizer manifold 57 communicating with separate economizer return lines 61 , each having a shut off valve 59 .
[0020] In this embodiment, the control 19 has the ability to open the valves 59 and adjust expansion device 56 to control the economizer loop. This control strategy is employed in combination with the abovementioned control methodology for operating the valves 32 to utilize either or both of the compressors. In addition, the bypass or unloader valves 51 provide further ability to reduce the refrigerant flow into the cycle. A worker of ordinary skill in the art would recognize the times when a controller would like to utilize each of these options. Valves 32 , 51 and 59 may be either shutoff valves or regulating flow control devices, allowing for more flexibility in the refrigerant flow control.
[0021] The economizer loop may or may not be engaged. To turn off the economizer loop, the economizer expansion device 56 may be closed down such that no refrigerant is tapped. Furthermore, to disengage an economizer cycle for each individual compressor, a respective valve 59 needs to be closed. Similarly, to turn off the reheat coil 60 , which is now positioned downstream of the condenser 36 and utilizes a two-phase mixture or liquid refrigerant for the reheat purpose, the three-way valve 58 may be moved to such a position that no refrigerant is tapped through the reheat coil 38 . It has to be noted, that the illustrated position of the reheat coil 60 and the economizer heat exchanger 52 is not critical to take advantage of the invention benefits, and various possible arrangements become obvious to a person ordinarily skilled in the art.
[0022] Further, as is shown, a bypass line 64 with a valve 65 selectively bypasses refrigerant around the condenser 36 . The valve 65 preferably allows a metering of flow around the condenser 36 . Now, when the system is utilized under conditions such that humidity control is desirable, but no significant temperature change is necessary, a significant portion of the refrigerant may be bypassed through line 64 , through valve 65 , and around the condenser 36 . This refrigerant is not cooled in the condenser 36 , and when mixed with the refrigerant passing through the condenser has more heating capacity to be realized in the reheat coil 60 , reheating refrigerant overcooled in the evaporator 40 . On the other hand, if greater temperature reduction is desired, then more or most of the refrigerant passes through the condenser 36 , and the system operates as in a standard cooling and dehumidification cycle, utilizing liquid refrigerant in the reheat coil 60 . Thus, any of these reheat loop controls may be employed independent of each other, in combination with the economizer loop controls and tandem compressor control strategy, or none of them need be used. The present invention is mainly directed to providing the ability to use all techniques in combination with each other, while providing better control over the humidity and temperature, while enhancing system efficiency by matching latent and sensible load demands more closely and improving component reliability by reducing a number of start-stop cycles. Also, it has to be understood that the three-way valve 58 can be substituted by a pair of conventional valves. If the expansion device 56 is of such a type that it cannot be closed down completely, an additional shutoff valve may be placed on the tap line 54 .
[0023] When relatively low humidity and temperature levels are desired in the air stream 45 , or the capability to provide a significant amount of sensible and latent capacity is required, both economizer expansion device 56 and the three-way valve 58 are moved to an open position to operate both the economizer heat exchanger 56 and the reheat coil 60 and both tandem compressors 22 and 24 are controlled to provide maximum refrigerant flow with valves 32 and 59 in open positions and valves 51 closed. Refrigerant passing through the main line 55 will be subcooled by the refrigerant from the tap 54 . Thus, that refrigerant will have a higher cooling capacity (both sensible and latent) when reaching the evaporator 40 . Consequently an air stream 45 leaving evaporator 40 can be cooled to a lower temperature. At this lower temperature, more moisture can be removed from the air. Then, refrigerant in the refrigerant cycle 50 passes through the reheat coil 60 , where its temperature is reduced further during the heat transfer interaction with the indoor air stream 46 leaving the evaporator 40 . As a result, the refrigerant cooling capacity is boosted even further, allowing for even more dehumidification in the evaporator 40 . This drier air then passes over the reheat coil 60 , which will have a higher temperature refrigerant, as it is positioned upstream of the main expansion device 38 . An air moving device 42 , shown schematically, drives air over the evaporator 40 and reheat coil 60 . This hotter refrigerant in the reheat coil will reheat the air stream 45 such that the desired temperature is reached. Moisture has already been removed from this air stream in the evaporator 40 . Thus, by utilizing the combination of the economizer cycle, tandem compressor configuration and the reheat coil, a refrigerant system designer is able to achieve both desired temperature and humidity levels, especially in hot and humid environments. Moreover, the higher efficiency levels are achieved due to implementation of the economizer cycle concept. Obviously, other external load demand scenarios can be considered along with corresponding control strategies for the refrigerant cycle 50 . These scenarios are well known to a person ordinarily skilled in the art.
[0024] Furthermore, this invention offers additional steps of unloading. Turning a tapped refrigerant flow in the economizer heat exchanger 26 on and off, the system capacity can be correspondingly increased or decreased, depending on the external load requirements. Also, one or both compressors 22 and 24 can be operated in the conventional, economized or unloaded modes. Again, this provides several distinct capacity control steps. This will allow matching the desired temperature and humidity levels with a greater precision as well as improve system reliability through the reduction of the start-stop cycles. Also it has to be understood that various configurations of this embodiment are possible including (but not limited to) more than two compressors, and more than one economizer heat exchanger.
[0025] FIG. 3 shows yet another embodiment 70 . In embodiment 70 , the reheat coil 74 communicates with the main cycle refrigerant by means of a three-way valve 72 downstream of the economizer heat exchanger 52 . Thus, there would be a warm liquid refrigerant circulated through the reheat coil. Further, the compressors 22 and 24 are provided with a bypass line through valve 51 on only one of the two compressors (here compressor 24 ). Further, the economizer fluid is returned through line 28 to only one of the two compressors (here compressor 24 as well). While this embodiment does not provide the extreme number of steps of control provided by FIG. 2 embodiment, it does provide additional control when compared to a system that does not have tandem compressors, an economizer cycle or a reheat coil. The two tandem compressors 24 and 22 can still be operated independently, or in combination. The economizer cycle would only be utilized in combination with operation of compressor 24 . Any number of economized and conventional compressors can be employed in this embodiment and will function and communicated to the refrigerant system 70 in the manner described above.
[0026] It should be understood that a refrigerant cycle designer would be able to identify many different options that would flow from the several embodiments in this invention. Additionally, an equivalent approach can be applied to each independent circuit of a multi-circuit system to obtain similar benefits.
[0027] Thus, the invention presents a significantly enhanced control over temperature and humidity precisely satisfying latent and sensible capacity demands, while reaching superior efficiency and reliability levels and reducing life-cycle cost of equipment.
[0028] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
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A refrigerant system incorporates at least two compressors that act in tandem to provide variable control over the refrigerant system performance. The tandem compressors can be of conventional or economized type and are configured for maximum performance utilization. Further, a reheat circuit can be incorporated into the refrigerant system at several different locations. The reheat cycle provides additional control over sensible and latent capacity of the refrigerant system, and is particularly advantageous when utilized in combination with the tandem compressors. As a result, multiple steps of unloading can be implemented in all operation regimes, the external load demands are satisfied with much greater precision, eliminating undesirable variations in temperature and humidity, system efficiency and reliability are augmented and equipment life-cycle cost is reduced.
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FIELD OF THE INVENTION
This invention generally relates to miscible blends of polyketones and phenolic novolacs. More particularly, this invention relates to blends of polyketone and phenolic novolacs which have good water vapor transport properties.
BACKGROUND OF THE INVENTION
Polymers of carbon monoxide and olefins generally referred to as polyketones are well known in the art.
Within this general class of polyketone polymers, this invention is particularly concerned with the sub-class comprising linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon. This type of polyketone polymer is disclosed in for example, U.S. Pat. No. 4,880,865, which is herein incorporated by reference.
Phenolic resins are very well known in the art. These are thermoset resins which are used in high-temperature electrical applications such as ovens and toasters, and as engineering materials.
Blends of polyketone with other polymeric materials such as polyamide (nylon), polycarbonate, polyester, and polyacetal are known in the art. Generally, these blends are immiscible polymer mixtures, which may in certain cases exhibit utility as a result of specific property advantages. Miscible blends between polyketone and poly(vinyl phenol) are also known in the art. The present invention involves polyketones and phenolic novolacs which also comprise a fully miscible blend system.
The present invention specifically relates to the use of polyketone/novolac blends in the preparation of materials having reduced permeability to water vapor. It is known in the art that polyketones possess properties set conducive to applications in packaging for food and drink. However, some applications in this area are limited by polyketone's excessive permeability to water vapor. One approach to improve polyketone's water barrier properties while experiencing minimal sacrifice in other important properties is by strategic blending with other polymers.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a miscible polyketone blend of polyketone and phenolic resins.
It is a particular object of the invention to provide a miscible blend of polyketone and novolac polymers which have and exhibit improved water vapor transport properties.
Accordingly, it is now provided a miscible polymer blend comprising a linear alternating terpolymer of carbon monoxide, ethylene, and at least one ethylenically unsaturated hydrocarbon of at least 3 carbon atoms, and a phenolic-based novolac polymer, having and exhibiting improved water vapor transport properties.
DETAILED DESCRIPTION OF THE INVENTION
Generally speaking, the materials needed to practice this invention include a linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon (hereinafter sometimes simply referred to as polyketone) and a phenolic-based novolac polymer (hereinafter sometimes simply referred to as novolac). Still generally speaking, the practice of this invention involves the admixing of the suitable quantities of these materials under conditions that result in the formation of a blend which has improved water vapor transport properties. The term improved water vapor transport properties as used herein means that in comparison to pure polyketone, the blend has superior or better water barrier properties i.e. reduced rate of water transport.
The useful materials and the practice of this invention are further disclosed in more detail in subsequent portions of this specification.
A prudent strategy for improving the barrier properties of a given polymer is to blend that polymer with another polymer which possesses superior barrier properties. If the blend is a compatible one, then a useful material may result. However, the above strategy is not the one employed in the present invention. The novolacs of the present invention are strongly hydrophilic materials, and thus would not be expected to improve the water barrier characteristics of polyketone. The improvement which is observed is therefore highly unexpected. To rationalize the observed phenomena, it is offered as one plausible explanation that the hydrogen bonding equilibria between water and each of the two blend components govern the barrier characteristics of the blend. In the blends of the invention, the two components, polyketone and novolac, hydrogen bonds so strongly with each other that the affinity that the resultant blend has for (hydrogen bonding with) water is reduced in comparison to that of each component in its pure state.
THE POLYKETONE POLYMER
The polyketone polymers of the invention are of a linear alternating structure and contain substantially one molecule of carbon monoxide for each molecule of unsaturated hydrocarbon. Hereinafter, these polymers may sometimes be simply referred to as polyketones. Suitable ethylenically unsaturated hydrocarbons for use as precursors of the polyketone polymers have up to 20 carbon atoms inclusive, preferably up to 10 carbon atoms, and are aliphatic such as ethylene and other α-olefins including propylene, 1-butene, isobutylene, 1-hexene, 1-octene and 1-dodecene, or are arylaliphatic containing an aryl substituent on an otherwise aliphatic molecule, particularly an aryl substituent on a carbon atom of the ethylenic unsaturation. Illustrative of this latter class of ethylenically unsaturated hydrocarbons are styrene, p-methylstyrene, p-ethylstyrene and m-isopropylstyrene. The preferred polyketone polymers are copolymers of carbon monoxide and ethylene or terpolymers of carbon monoxide, ethylene and a second ethylenically unsaturated hydrocarbon of at least 3 carbon atoms, particularly an α-olefin such as propylene.
When the preferred polyketone terpolymers are employed as the major polymeric component of the blends of the invention, there will be within the terpolymer at least about 2 units incorporating a moiety of ethylene for each unit incorporating a moiety of the second hydrocarbon. Preferably, there will be from about 10 units to about 100 units incorporating a moiety of the second hydrocarbon. The polymer chain of the preferred polyketone polymers is therefore represented by the repeating formula
--CO--CH.sub.2 --CH.sub.2 ].sub.x [CO--G].sub.y
wherein G is the moiety of ethylenically unsaturated hydrocarbon of at least 3 carbon atoms polymerized through the ethylenic unsaturation and the ratio of y:x is no more than about 0.5. When copolymers of carbon monoxide and ethylene are employed in the blends of the invention, there will be no second hydrocarbon present and the copolymers are represented by the above formula wherein y is zero. When y is other than zero, i.e., terpolymers are employed, the --CO--CH 2 CH 2 -- units and the --CO--G-- units are found randomly throughout the polymer chain, and preferred ratios of y:x are from about 0.01 to about 0.1. The end groups or "caps" of the polymer chain will depend upon what materials were present during the production of the polymer and whether or how the polymer was purified. The precise nature of the end groups does not appear to influence the properties of the polymer to any considerable extent so that the polymers are fairly represented by the formula for the polymer chain as depicted above.
Of particular interest are the polyketone polymers of number average molecular weight from about 1000 to about 200,000, particularly those of number average molecular weight from about 20,000 to about 90,000 as determined by gel permeation chromatography. The physical properties of the polymer will depend in part upon the molecular weight, whether the polymer is a copolymer or a terpolymer and, in the case of terpolymers, the nature of the proportion of the second hydrocarbon present. Typical melting points for the polymers are from about 175° C. to about 300° C., more typically from about 210° C. to about 270° C. The polymers have a limiting viscosity number (LVN), measured in m-cresol at 60° C. in a standard capillary viscosity measuring device, from about 0.5 dl/g to about 10 dl/g, more frequently from about 0.8 dl/g to about 4 dl/g.
A preferred method for the production of the polyketone polymers is illustrated by U.S. Pat. No. 4,843,144 (Van Broekhoven et al.). The carbon monoxide and hydrocarbon monomer(s) are contacted under polymerization conditions in the presence of a catalyst composition formed from a compound of palladium, the anion of a non-hydrohalogenic acid having a pKa (measured in water at 18° C.) of below about 6, preferably below 2, and a bidentate ligand of phosphorus. The scope of the polymerization is extensive but, without wishing to be limited, a preferred palladium compound is a palladium carboxylate, particularly palladium acetate, a preferred anion is the anion of trifluoroacetic acid or p-toluenesulfonic acid and a preferred bidentate ligand of phosphorus is 1,3-bis(diphenylphosphino)propane or 1,3-bis[di(2-methoxyphenyl)phosphino]-propane.
The polymerization to produce the polyketone polymer is conducted in an inert reaction diluent, preferably an alkanolic diluent, and methanol is preferred. The reactants, catalyst composition and reaction diluent are contacted by conventional methods such as shaking, stirring or refluxing in a suitable reaction vessel. Typical polymerization conditions include a reaction temperature from about 20° C. to about 150° C., preferably from about 50° C. to about 135° C. The reaction pressure is suitably from about 1 atmosphere to about 200 atmospheres but pressures from about 10 atmospheres to about 100 atmospheres are preferred. Subsequent to polymerization, the reaction is terminated as by cooling the reactor and contents and releasing the pressure. The polyketone polymer is typically obtained as a product substantially insoluble in the reaction diluent and the product is recovered by conventional methods such as filtration or decantation. The polyketone polymer is used as recovered or the polymer is purified as by contact with a solvent or extraction agent which is selective for catalyst residues.
PHENOLIC-BASED NOVOLAC POLYMERS
These are generally referred to as two-step phenolics and are produced when a less-than-stochiometric amount of formaldehyde is reacted with phenol in an acidic solution to form a solid product that cannot react to completion without additional formaldehyde. The novolacs so formed are thermoplastic polyphenols. Thermoset characteristics can be imparted to these thermoplastics phenols by the addition of hexamethylenetramine (hexa), a catalyst which acts as a source of formaldehyde. Additional information on phenolic-based novolac polymers, can be obtained from the following references: Textbook of Polymer Science (3ed) by Fred W. Billmeyer, Jr., Pages 436-440; and Modern Plastic Encyclopedia, 1988 (ed) Pages 114-116. The relevant portions of these references are herein incorporated by reference.
The novolac polymers useful herein can be approximately represented by the general formula: ##STR1## wherein R 1 is H, OH, or any alkyl group containing 8 carbon atoms or less and R 2 is H, or any alkyl group containing 8 carbon atoms or less.
These novolac polymers are exemplified by phenol-formaldehyde, resorcinol-formaldehyde, resorcinol-formaldehyde, p-butyl phenol-formaldehyde, p-ethyl-phenol-formaldehyde, p-hexyl phenol-formaldehyde, p-propyl phenol-formaldehyde, p-pentyl-phenol-formaldehyde, p-octyl-phenol-formaldehyde, p-heptyl phenol-formaldehyde and p-nonyl-phenol-formaldehyde. These various novolac polymers differ in their R 1 and R 2 substituents, melting points, viscosities, and other properties. Recommended commercial sources for obtaining these compounds include Schenectady Chemicals Company and Georgia Pacific Company.
Table A further details the various novolacs and their properties.
TABLE A__________________________________________________________________________Novolac Polymers UsedDesignation Description R.sub.1 R.sub.2__________________________________________________________________________HRJ 2190 (A) Phenol-Formaldehyde Novolac --H --H Viscosity.sup.(1), 4000 cp M.P. 110° C..sup.(2)HRJ 1166 (B) Phenol-Formaldehyde Novolac --H --H Viscosity.sup.(1), 1100 cp M.P. 84° C..sup.(2)SRF 1501 (C) Resorcinol-Formaldehyde --OH --H M.P. 105° C.HRJ 2901 (D) Cresol-Formaldehyde --CH.sub.3 H melting point 190° C.HRJ-2355 (E) p-butyl Phenol-Formaldehyde --H --(CH.sub.2 --) .sub.3 CH.sub.3 melting point 116° C.SP-1090 (F) p-nonyl Phenol-Formaldehyde --H --(CH.sub.2 --) .sub.8 CH.sub.3 melting point 93° C.GP-2074 (G) Phenol-Formaldehyde Novolac --H --H__________________________________________________________________________ .sup.(1) Viscosity of Novolacs from cone and plate as determined by ASTM D4287-83 .sup.(2) Melting point of Novolacs were determined by ASTM E2867
CONVENTIONAL ADDITIVES
These additives generally include plasticizers, antioxidants, mold release agents and pigments. These additives can be added by conventional methods prior to, together with or subsequent to admixing the polymer and the mineral filler(s).
The following illustrative examples and table further detail the various aspects of this invention.
EXAMPLE 1
Preparation of Polyketone Polymer
A terpolymer of carbon monoxide, ethylene and propylene was produced in the presence of a catalyst composition formed from palladium acetate, trifluoracetic acid and 1,3-bis[di(2-methoxyphenyl)-phosphino]propane.
The terpolymer had a melting point of 220° C. and an LVN, measured in m-cresol at 60° C., of 1.75 dl/g.
EXAMPLE 2
A polyketone control (P-1000/2, MP 220C, LVN 1.75) was compression molded at 245° C. for 90 seconds and subsequently cooled to room temperature between aluminum plates to produce a 4"×4" plaque which was 0.030" in thickness.
A blend containing 90 wt % of the above polyketone and 10 wt % of a phenolic novolac (HRJ 2190 from Schenectady Chemical) was melt compounded in a Haake 30 mm co-rotating twin screw extruder operating at 250° C. and 200 RPM. The extrudate was cooled in a water bath and passed through a pelletizer. The pellets were dried under vacuum at 60° C. for 16 hrs and subsequently compression molded as described above.
The permeability of the materials to water vapor was determined using a Mocon cell with a modulated infared sensor according to the method of ASTM F 1249. Permeability was measured at 100° F. and 90% relative humidity. The results are shown in Table 1. Under these conditions, the water vapor permeability of the material is reduced by a factor of approximately four by virtue of blending with 10% HRJ 2190.
TABLE I______________________________________Water Vapor Permeability ResultsMaterial Permeability (g-mil/100 in.sup.2-day)______________________________________Polyketone Control 13.690/10 PK/Nov Blend 3.6______________________________________
EXAMPLE 3
Blends were prepared between a polyketone polymer 90/064 (MP 220C, LVN 1.1) and three novolac materials-HRJ 2190, HRJ 2355, and SP 1090. These novolacs are described in Table A. The blending was performed as described in Example 2. The compounded blends were injection molded in 7.5 oz. cups using a Krauss-Maffei 100-ton injection molding machine. The cups processed an average wall thickness of 0.027" and a surface area for permeation of 28.3 in 2 .
The cups were filled with water, double-seamed with an aluminum lid, maintained in a 50% relative humidity environment, and weighed periodically to determine water loss over time. Some of the samples were also subjected to a retort (sterilization) cycle in a Barnstead benchtop sterilization unit with 15 psig overpressure. The retort temperature was increased until the internal temperature reached 260° F., at which point the container was slowly cooled to 150° F. The total cycle required about three hours. The water transmission rate for these containers are shown in Table 2. The transmission rate is expressed in terms of the rate at which the containers lose weight through water transport in units of percent weight lost per year.
TABLE 2______________________________________WVTR rate reduction of polyketone polymer/novolac blends.Measurement conducted on 27 mil wall thickness cups.MATERIAL Control HRJ-2190 HRJ-2355 SP-1090______________________________________WVTR BEFORE RETORT (Percent/Year)Polyketone 7.890/0641% novolac 6.4 7.2 7.52% novolac 5.5 6.6 7.75% novolac 4.0 5.5 7.210% novolac 2.5 4.5 7.1WVTR AFTER RETORT (Percent/Year)Polyketone 10.890/0641% novolac 8.8 9.4 10.22% novolac 7.5 8.6 10.45% novolac 5.2 7.2 9.610% novolac 3.2 6.7 9.3______________________________________
Table 2 demonstrates that the phenol-based novolac (HRJ 2190 ) is very effective with regard to reducing the rate of water transport through the container. A significant reduction in transport rate in comparison to the control is observed with only 1 wt % added novolac. At 10% novolac the rate is reduced by a factor greater than three. The butyl phenol-based novolac is someehat less efficient. At 10% modifier, the transport ratae is about 60% that of the control. The nonyl phenol novolac provided only a marginal improvement in the water transport rate. These differences in effectiveness are attributable to differences in the strength of interaction of the novolacs with the polyketone. This interaction strength decreases as the size of the alkyl group on the novolac increases, such that the nonyl novolac forms an imiscible blend with polyketone (and hence is less effective at reducing water transport rate) whereas the other novolac blends are fully miscible.
In all cases, subjecting the containers to a retort cycle causes the rate of water loss to increase. This in an effect know as "retort shock". The blends are more effective at reducing water transport after retort.
EXAMPLE 4
A polyketone polymer (91/026, MP 220° C., LVN 1.3) was blended with two different novolac resins, HRJ 2190 from Schenectady Chemical, and GP 2074 from Georgia-Pacific at levels of 5 to 15 wt %. The blends were prepared using the procedures of Example 2 and containers were fabricated and tested using the procedures of Example 3. The results are shown in Tables 3 and 4.
TABLE 3______________________________________Water Vapor Rate of polyketone/novolac blends.Composition Novolac WVTR (before retort) WVTR (after(PK/Nov) Type (%/yr) retort) (%/yr)______________________________________100/0 -- 7.10 9.6595/5 GP 2074 4.29 6.1390/10 GP 2074 3.21 4.1285/15 GP 2074 2.65 3.3990/10 HRJ 3.08 4.06 2190______________________________________
TABLE 4______________________________________Falling dart impact properties of polyketone/novolac containers.Composition Novolac Maximum Load Energy at Max Load(PK/Nov) Type (lbs) (in-lb)______________________________________100/0 -- 89.9 1.3295/5 GP 2074 102.8 1.3590/10 GP 2074 124.2 1.6585/15 GP 2074 137.0 1.8690/10 HRJ 112.1 1.42 2190______________________________________
Table 3 provides the water vapor transport data for these containers. The data in this table provide further confirmation that the rate of weight loss through water permeation is greatly diminished by virtue of blending the polyketone with minor amounts of novolac resin.
The containers could be molded without difficulty, had a good appearance and maintained good mechanical integrity. Room temperature impact resistance of polyketone polymer/novolac blends was measured on injection molded cups (0.027 inch thick) using a Dynatup 8250 impact machine. The cups were rigidly fixed in a jig such that the falling dart penetrated the bottom center of the cup. A weight of 6.23 pounds was dropped freely (no pneumatic assistance) from 3.0 feet using a tup of 0.625 inch diameter. Load as a function of time was measured and converted to load versus displacement by multiplying by the impact velocity. Impact energy was calculated from the integral of the load versus displacement curve. Both total impact energy and maximum load experienced during fracture of the cups are considered to be indicative of the relative impact resistance of the polymer blends.
Table 4 gives the force and energy required to puncture the bottom of the containers. The data show that the addition of novolac actually increases the force and energy required to puncture the containers relative to the pure polyketone control.
The combined data in Tables 3 and 4 demonstrate that the addition of novolac in relatively low amounts (up to about 15%) provides a container having improved water barrier (by a factor of 3-4) with undiminished processing characteristics and mechanical properties.
TABLE 5__________________________________________________________________________Immersion ControlTime 91026 10% HRJ2190 5% GP2074 10% GP2074 15% GP2074(days) Wt (gms) % Chg. Wt (gms) % Chg. Wt (gms) % Chg. Wt (gms) % Chg. Wt (gms) % Chg.__________________________________________________________________________0 3.888 0 3.801 0 3.775 0 3.895 0 3.739 02 3.969 2.086 3.870 1.818 3.849 1.955 3.974 2.023 3.815 2.0303 3.969 2.089 3.872 1.871 3.853 2.066 3.975 2.056 3.817 2.0814 3.971 2.143 3.872 1.876 3.851 2.002 3.975 2.051 3.817 2.0868 3.973 2.184 3.872 1.865 3.850 1.987 3.974 2.010 3.815 2.03026 3.978 2.328 3.870 1.823 3.853 2.058 3.973 1.995 3.814 1.99241 3.981 2.405 3.868 1.768 3.854 2.093 3.971 1.951 3.811 1.92057 3.987 2.552 3.868 1.771 3.853 2.066 3.970 1.913 3.811 1.918__________________________________________________________________________
Pieces of the molded containers of Example 4 were immersed in distilled water at room temperature for approximately two months. Table 5 shows the weight changes which the various materials experienced as a result of water absorption. Table 5 demonstrates that after several weeks of immersion, the blends absorb less water than the neat polyketone control. This is surprising since novolacs are known to be hydrophilic and absorb 10% or more of their weight in water (in the uncrosslinked state). This unexpected observation of reduced water absorption in the present blends is useful in itself and is related to the blends reduced water transport. It is also consistent with our hypothesis that strong hydrogen bonding between the polyketone and novolac constituents reduces the materials affinity for water.
While this invention has been described in detail for purposes of illustration, it is not to be construed as limited thereby but is intended to cover all changes and modifications within the spirit and scope thereof.
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A miscible polymer blend comprising polyketone and phenolic-based novolac polymers is provided. These blends have and exhibit improved water vapor transport properties. A process for producing these blends and articles of manufacture produced therefrom are also disclosed.
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BACKGROUND
[0001] Rotary earth drills are commonly used in drilling operations, especially for drilling holes and conducting subsurface soil testing. These drills utilize drill bits to cut away soil and rock which is then removed from the drilling area up the shaft. Frequently, drill bits break, or lose their edge with age and use, and when they cease to be effective in removing soil or rock, the drilling operation must be stopped, the drill removed and the bits replaced. Therefore, it is desirable to utilize drill bits that retain their edge for the longest possible duration to reduce the occurrence of bit replacement.
[0002] Additionally, after drill bits have been used in drilling operations, it is often difficult to remove them from the heads. This is especially true because it is desirable to perform replacements on site, which is typically in a remote area with limited resources. Some mounting methods have been used that simplify replacement, but result in an increased incident of drill bits coming detached from the head during drilling operations.
[0003] Accordingly, a continuing search has been directed to the development of tools that are more rugged and durable that need to be replaced less frequently, drill earth with greater efficiency, and that can be replaced easily on site, when necessary.
SUMMARY
[0004] The present invention is directed to a rotary earth auger that utilizes drill bit assemblies to which both blades and finger bits are attached. The configuration and arrangement of the bits improves cutting efficiency, increases wear life and reduces the likelihood of the bits breaking during operation.
[0005] The individual drill bit assemblies have a self-locking hook configuration and are retained on the auger head by means of a unique sandwich mechanism to reduce incidents of the drill bit assembly becoming detached from the auger during drilling operations. Additionally, the drill bit assemblies are attached to the auger using an attachment method that resists rusting when the drill is in use, which makes the drill bit assemblies easier to remove from the drill when it is necessary to replace the bits.
[0006] The invention is a hollow auger head assembly for penetrating geological formations, comprising a hollow auger head configured such that it can be secured to a conventional auger used for drilling, and at least two drill bit assemblies secured to the hollow auger head. Each drill bit assembly comprises a drill bit body having a means of attachment, at least one finger bit secured to the underside of the drill bit body, and at least one blade secured to the front edge of the drill bit body.
[0007] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0009] [0009]FIG. 1 is a bottom elevation view of a hollow auger head assembly embodying features of the present invention;
[0010] [0010]FIG. 2 is a partially exploded view showing assembly of the parts of a hollow auger head assembly of the present invention;
[0011] [0011]FIG. 3 is a partially exploded view showing assembly of the parts of a hollow auger head of the present invention;
[0012] [0012]FIG. 4 is a view of the underside of a drill bit assembly of the present invention; and
[0013] [0013]FIG. 5 is a detailed view of a drill bit assembly of the present invention.
DETAILED DESCRIPTION
[0014] In the discussion of the FIGURES the same reference numerals will be used throughout to refer to the same or similar components. In the interest of conciseness, various other components known to the art, such as drilling components and the like have not been shown or discussed. Numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details.
[0015] Referring to FIG. 1 of the drawings, the reference numeral 100 generally designates the hollow auger head assembly of the present invention. The assembly 100 includes a hollow auger head 10 , and one or more drill bit assemblies 50 .
[0016] [0016]FIG. 2 shows the assembly of the parts that comprise the hollow auger head assembly 100 of the present invention. Each drill bit assembly 50 is secured to the hollow auger head 10 . In a preferred embodiment of the present invention, the securing method comprises a rust-resistant bolt 2 and a rust-resistant nut 4 , made of a material such as stainless steel. It will be obvious to those skilled in the art that the securing method can be other than a nut 4 and bolt 2 ; however, it is desirable to use a securing method that will keep the pieces securely together during use. Similarly, while the securing method can be made of any material, it is desirable to use materials that resist rusting so the drill bit assembly 50 can be easily detached from the hollow auger head assembly 100 after it has been in use in subterranean conditions.
[0017] [0017]FIG. 3 shows the parts of the hollow auger head assembly 100 . The hollow auger head 10 comes in various sizes that correspond with standard size augers used in drilling operations so the hollow auger head assembly 100 can be used with standard drilling equipment. The number of drill bit assemblies 50 that will be used in a particular hollow auger head assembly 100 depends on, among other things, the size of the auger being used. Typically, at least two drill bit assemblies 50 are used on a hollow auger head assembly 100 .
[0018] The hollow auger head 10 consists of an auger pin 12 to which two or more brackets, or sets of brackets 20 , have been cast, or welded, soldered, or otherwise secured, depending on the number of drill bit assemblies 50 that will be used on that hollow auger head assembly 100 . The sets of brackets 20 are positioned equidistant from each other around the circumference of the auger pin 12 . The auger pin 12 is configured with through-material holes 13 and keyway grooves 14 such that it can be connected with conventional augers, and an auger key will fit into a keyway 14 on the auger pin 12 .
[0019] In a preferred embodiment of the present invention, a set of brackets 20 is used to secure each drill bit assembly 50 to the auger pin 12 . Each bracket set 20 consists of a top bracket 22 , a lower bracket 24 and a back bracket 26 , each of which is cast, or soldered or welded to the auger pin 12 along one side such that a gap exists between the top bracket 22 and lower bracket 24 of a size such that the drill bit assembly 50 can be inserted between the top bracket 22 and lower bracket 24 . By positioning the drill bit assembly 50 between a top bracket 22 and a lower bracket 24 , the drill bit assembly 50 is given greater security and is therefore less likely to break or become disconnected during use.
[0020] The drill bit assembly 50 is inserted into the gap between the top bracket 22 and lower bracket 24 and the holes in the brackets 22 , 24 and drill bit assembly 50 are aligned. In a preferred embodiment, a bolt 2 is inserted through the holes in the brackets 22 , 24 and drill bit assembly 50 , and secured with a nut 4 .
[0021] When the drill bit assembly 50 is properly positioned between the upper bracket 22 and lower bracket 24 , the rear edge of the drill bit assembly 50 should be close to the back bracket 26 . The back bracket 26 provides lateral stability for the drill bit assembly 50 when the hollow auger head assembly 100 is in use. This reduces the likelihood of the drill bit assembly 50 moving relative to the brackets such that the bolt 2 could become loose, or be subject to shear pressure such that it would break.
[0022] As shown in FIG. 2, the top bracket 22 has a front edge that has a sinusoidal shape comprising a protruding finger 21 and a recessed curved slot 23 . The front edge of the top bracket 22 forms an interlock with the mirror image sinusoidal shape of the upper edge of the drill bit assembly 50 . The finger 21 on the top bracket 22 fits snugly into the receptacle on 51 on the drill bit assembly 50 , while the finger 53 on the drill bit assembly 50 fits into the receptacle 23 on the top bracket 22 . Even if the bolt 2 were to become loose or break, this self-locking interlock would help ensure the drill bit assembly 50 stayed securely positioned in the top bracket 22 .
[0023] [0023]FIG. 2 also shows the positioning of the bracket sets 20 on the hollow auger head 10 , relative to the auger pin 12 and each other. The positioning of the bracket sets 20 , and as a result the drill bit assemblies 50 , on the hollow auger head 10 relative to each other is an important consideration in the functionality of the hollow auger head assembly 100 . The arrangement of the drill bit assemblies 50 on the hollow auger head assembly 100 is such that the finger bit or bits 60 on a drill bit assembly 50 loosens material and feeds it to the blade 56 on the next drill bit assembly 50 on the auger head assembly 100 for further processing. Proper positioning of the drill bracket sets 20 on the hollow auger head 10 ensures that the drill bit assemblies 50 are properly positioned so that the loosened material is delivered to the blade 56 of the next drill bit head assembly 50 in an efficient manner.
[0024] In alternative arrangements of the present invention, a different number of brackets can be used to secure the drill bit assembly 50 to the hollow auger head 10 . Similarly, brackets of a different shape can be used to secure the drill bit assembly 50 to the auger pin 12 .
[0025] The underside of a drill bit assembly 50 is shown in detail in FIG. 4. The hole 52 for securing the drill bit assembly 50 to the bracket set 20 can be clearly seen. The drill bit assembly 50 shown has one conical finger bit 60 on the underside. However, depending on the particular configuration of the auger head assembly 100 being used, more than one finger bit 60 can be used. The finger bits 60 are designed so that when they are mounted on the drill bit assembly 50 , the cutting edge of the finger bit 60 has a negative rake, or angle, relative to the movement of the hollow auger head assembly 100 .
[0026] Because the cutting portion of the finger bit 60 contacts the geological material which it is drilling into at a negative angle, the cutting edge of the finger bit 60 is protected from excessive wear and cracking that would reduce the life of the finger bit 60 . The negative angle relative to the geological material also reduces the impact between the finger bit 60 and the geological material, which reduces the wear on the finger bit 60 and the likelihood of damage to the finger bit 60 .
[0027] Additionally, a layer of high-quality, wear-resistant metal, such as tungsten carbide or carbide coated metals may be bonded to at least the cutting edge of the finger bit 60 to increase the life of the finger bit 60 . The layer of wear-resistant material may be secured to the finger bit 60 by means such as brazing or use of a bonding material, which bonds the finger bit 60 and wear-resistant materials together when heated.
[0028] In alternate arrangements of the hollow auger head assembly 100 , finger bits 60 that are of a shape other than conical can also be used. The shape, number and position of the finger bits 60 used depends on the exact configuration and intended usage for the hollow auger head assembly 100 .
[0029] [0029]FIG. 5 shows a detailed view of a drill bit assembly 50 of the present invention. The drill bit assembly 50 comprises a drill bit body 54 , one or more finger bits 60 , and a blade 56 secured along the front of the drill bit body. A hole 52 has been cut, reamed or drilled through the drill bit body 54 to allow insertion of a fastening mechanism so the drill bit assembly 50 can be secured to a bracket set 20 .
[0030] The drill bit body 54 is shaped to have an inward facing receptacle 51 and a finger 53 along the top of the drill bit body 54 . The finger 53 on the drill bit body 54 fits snugly into the receptacle 23 on the top bracket 22 of the hollow auger head 10 , while a finger 21 on the top bracket 22 fits snugly into the receptacle on 51 on the drill bit body 54 . The drill bit body 54 has a downward slope 55 from the receptacle 51 and finger 53 to the front edge of the drill bit body 54 where the blade 56 is secured. This slope 55 is useful in channeling processed geological material away from the blade 56 and up and out the auger.
[0031] The blade 56 is comprised of one or more pieces of hardened, wear-resistant material secured along the front edge or edges of the drill bit body 54 . The blade 56 is usually made of wear-resistant metal, such as tungsten carbide or carbide coated metals which may be secured to the drill bit by means such as brazing or use of a bonding material which bonds the drill bit body 54 and blade 56 together when heated. The material can be sharpened as needed, and will retain the sharpened edge for an extended period of time. In some configurations of the drill bit assembly 50 , hardened material is also placed along the front slope 55 of the drill bit body 54 . In some configurations of the drill bit assembly 50 , hardened material is also placed along the outer edge of the drill bit body 54 for cutting and processing of geological materials which come in contact with that edge of the drill bit assembly 50 . The exact position and number of pieces of material on the drill bit body 54 depends on the specific arrangement and use of the hollow auger head assembly 100 .
[0032] In operation, the hollow auger head assembly 100 is secured to an auger and used to drill into geological formations. The drill bit assemblies 50 are positioned around the hollow auger head 10 an appropriate distance from each other and in a proper alignment relative to each other. As the auger is rotated, the finger bits 60 on the drill bit assemblies 50 break up the geological material with which they come in contact. The negative angle of each finger bit 60 is such that the geological material it has broken up is fed back and up to the blade 56 of the next drill bit assembly 50 on the hollow auger head assembly 100 . That blade 56 , further processes and breaks up the geological material, and then feeds it up over the front slope 55 of the drill bit assembly 50 , and subsequently up the auger and out of the drilling area.
[0033] Because a finger bit 60 on a drill bit assembly 50 feeds the blade 56 of the next drill bit assembly 50 on the hollow auger head assembly 100 , positioning of the drill bit assemblies 50 on the hollow auger head assembly 100 relative to each other is critical. Further, the combination of finger bits 60 and blades 56 in a single assembly increases efficiency of breaking up and moving away of geological materials in the drilling operation.
[0034] It is understood that the present invention can take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention. For example, the position, shape and number of finger bits 60 on a drill bit assembly can be varied. As another example, pieces of hardened material can be attached to the outside edge of the drill bit assembly by a variety of methods. These pieces of hardened material can assist in the breaking up of the geological formation being processed. The position, shape and number of pieces of hardened material can vary, and still be within the scope of the present invention. Yet another example is the number of pieces, shape and size of the pieces of hardened material affixed to the front of the drill bit assembly, which can be varied, but still fall within the scope of the present invention.
[0035] Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A hollow auger head assembly for penetrating geological formations that utilizes drill bit assemblies to which both blades and finger bits are attached. The method of securing the individual drill bit assemblies to the auger head reduces incidents of the drill bit assembly becoming detached from the auger head during drilling operations. Additionally, a rust-resistant attachment mechanism is used attach the drill bit assemblies to the auger head, which makes the drill bit assemblies easier to remove and replace. The configuration and arrangement of the bits improves cutting efficiency, increases wear life and reduces the likelihood of the bits breaking during operation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to cellular communications systems and, more particularly, to a frequency reuse plan therefor.
2. Description of the Related Art
Frequency reuse is the use of radio channels on the same carrier frequency for the coverage of geographically different areas and is necessary in order to construct practical, high-capacity cellular systems in traffic-dense areas, such as big cities. Needless to say, these geographically different areas which include the same radio carrier frequencies must be far enough apart to ensure that co-channel interference either does not arise or does not arise to an objectional level.
An important measurable characteristic of frequency reuse schemes is carrier-to-interference ratio ("C/I ratio"). The C/I ratio is defined to be the ratio of the level of the received desired signal to the level of the received undesired signal. Because of irregular terrain and the various shapes, types and numbers of local scatterers, the C/I ratio is dependent upon the instantaneous position of a mobile moving through a cell. Other factors such as antenna type, directivity and height, site elevations and positions, and the number of local interferers also affect the C/I ratio at various locations within a system.
The desired distribution of the C/I ratio in a system determines the number of frequency groups, F, which may be used. If the total allocation of N channels is partitioned into F groups, then each group will contain N/F channels. Since the total number of N channels is fixed, for example, there are 312 voice channels in the F.C.C. Standard A Band, a smaller number of F frequency groups would result in more channels per set and per cell site. Therefore, a reduction in the number of frequency groups would allow each site to carry more traffic, reducing the total number of sites needed for a given traffic load. However, decreasing the number of frequency groups and reducing the co-channel reuse distance results in a lower C/I distribution in the system.
FIGS. 1-3 are schematic illustrations of various prior art frequency reuse plans. In viewing these depictions, as well as all other illustrated frequency reuse plans, it should be appreciated that the illustrated cells are shown to have certain shapes. While in theory, cells may be envisioned as having any regular polygon shape, the important point is that the array of cells covers a plane without gaps or overlaps. Similarly, cell boundaries may be conceptually defined as lines at which the respective signal strengths of neighboring cells are equal. In reality, of course, because of such factors as random propagation effects, real cells only roughly approximate ideal cell shapes with ideal boundaries therebetween.
In considering the frequency reuse plans shown herein, it should be appreciated that equivalent site coverage areas, the same site locations, and 312 available voice channels are assumed in each plan. This reflects reality and allows fair comparisons to be made among the various plans.
Referring now to FIG. 1, there is shown a diagram of a 7/21 Cloverleaf Cell Plan as has heretofore been implemented by Ericsson, the assignee of the present invention. If may be seen that this plan employs a number of sites 2, each site serving three cells (or "sectors") 4. Each cell 4 contains a dedicated antenna system, a control channel, a signal strength receiver, and voice channels. In FIG. 1, certain groups of co-channel cells, i.e., cells employing the same frequencies, are shown cross-hatched, e.g., cells 4A and 4B. Using the same terminology, sites 2A and 2B should be appreciated to be co-channel sites.
Further with respect to FIG. 1, it may be seen that site 2A is centrally located within the illustrated system and that the outlying sites are all shifted two (2) units in a first ("i t h") direction and one (1) unit in a second ("j th ") direction from the central site. Defining i and j as shift parameters, the illustrated plan may be considered to have shift parameters of two (2) and one (1) respectively. Shift parameters are important characteristics of frequency reuse plans and will therefore be discussed with respect to each plan described herein.
Recalling that there are 312 available voice channels in the F.C.C. Standard A Band, the 7/21 Cloverleaf Cell Plan shown in FIG. 1 uses some 21 frequency groups in its seven repeating sites with approximately (although averaging somewhat less) 15 channels per group.
Supporting the three cell configurations shown in FIG. 1, each cell has antenna pointing azimuths separated by some 120°. More specifically, in practice, each cell uses 60° transmit antennas and two (2) 60° diversity receive antennas with the same pointing azimuths.
Referring now to FIG. 2, shown therein is a Three Rhomb Cell Plan as has heretofore been implemented by numerous operators, including the companies of the Bell System. Sites, cells and shift paraments are similarly marked in FIG. 2 as they were in FIG. 1. Examining FIG. 2, it should be appreciated that the Bell 7/21 Three Rhomb Cell Plan uses 21 Frequency groups in a seven site reuse pattern with approximately 15 channels per group. As with the Ericsson 7/21 Cloverleaf Cell Plan, the shift parameters, i and j, are two (2) and one (1) respectively. Site geometry in the Bell plan involves three cells 4 or sectors at each site 2. The antenna pointing azimuths of each cell are separated by 120°. Each cell uses 120° transmit antennas and two (2) 120° diversity receive antennas with the same pointing azimuths. Additionally, each cell is approximated by the shape of a rhomboid.
Referring now to FIG. 3, shown therein is a 4/24 Six Triangle Cell Plan as has heretofore been implemented by Motorola. This plan uses 24 frequency groups in a four site reuse pattern with 13 channels per group. The corresponding shift parameters i and j are two (2) and zero (0), respectively. The site geometry involves six cells 4 at each site 2 with antenna pointing azimuths separated by 60°. Each cell uses one (1) 60° antenna with the transmit and receive functions duplexed. Additionally, each cell is approximated by the shape of an equilateral triangle.
Further details regarding each of the above plans will be set forth below in various comparisons with the plan according to the present invention. In general however, it may be noted and should be appreciated by those skilled in the art that each of the prior art systems possesses shortcomings in that a number of important system characteristics; e.g., C/I performance, capacity, utilization, and site position tolerance, could be improved.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a frequency reuse plan having improved C/I, capacity, utilization, and site performance tolerance than prior art plans.
To fulfill the above and other objects, and to overcome the shortcomings and deficiencies of the prior art, the present invention provides a cellular radio communications system including a plurality of sites wherein groups of four sites reuse frequencies. The system includes means for implementing twelve groups of frequencies among the plurality of sites with each of the twelve groups of frequencies including twenty-six channels.
Embodiments of the frequency reuse plan according to the teachings of the present invention has shift parameters, i and j, of two (2) and zero (0), respectively.
Embodiments of the plan of the present invention may further include groups of three cells which surround each site. These cells may be hexagon-shaped and, further, may be arranged in a cloverleaf fashion.
Still further, in other embodiments of the present invention each cell may have antenna pointing azimuths, each of which may be separated by approximately 120°. Yet still further, each cell may include 60° transmit antennas and two diversity receive antennas with the same pointing azimuths.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 depicts a prior art Ericsson 7/21 Cloverleaf Cell Plan, previously discussed;
FIG. 2 depicts a prior art Bell 7/21 "Three Rhomb" Cell Plan, previously discussed;
FIG. 3 depicts a prior art Motorola 4/24 "Six Triangle" Cell Plan, previously discussed;
FIG. 4 depicts a frequency reuse plan according to the teachings of the present invention;
FIG. 5 is a graph comparing channel utilization of the four frequency reuse plans discussed herein;
FIG. 6 is a graph comparing C/I performance of the four frequency reuse plans discussed herein;
FIG. 7 illustrates C/I predictions for the Ericsson 7/21 Cloverleaf Cell Plan, which predictions were used to generate the graph shown in FIG. 6;
FIG. 8 illustrates C/I predictions for the Ericsson 4/12 Cloverleaf Cell Plan according to the teachings of the present invention, which predictions were used to generate the graph shown in FIG. 6;
FIG. 9 illustrates C/I predictions for the Bell 7/21 "Three Rhomb" Cell Plan, which predictions were used to generate the graph shown in FIG. 6;
FIG. 10 illustrates C/I predictions for the Motorola 4/24 "Six Triangle" Cell Plan, which predictions were used to generate the graph shown in FIG. 6;
FIG. 11 depicts data relating to cell-site position tolerance of the Bell 7/21 "Three Rhomb" Cell Plan;
FIG. 12 depicts data relating to cell-site position tolerance of the Ericsson 4/12 Cloverleaf Cell Plan, an embodiment of the present invention;
FIG. 13 depicts comparison data relating to cell-site position tolerance of the Bell 7/21 "Three Rhomb" Cell Plan and the Ericsson 4/12 Cloverleaf Cell Plan;
FIG. 14 shows the cell geometry and relative receive antenna gain for incident angles of 0°, 30°, and 60° for the Ericsson system;
FIG. 15 shows the cell geometry and relative receive antenna gain for incident angles of 0°, 30°, and 60° for the Bell System;
FIG. 16 shows the cell geometry and relative receive antenna gain for incident angles of 0°, 30°, and 60° for the Motorola system;
FIG. 17 is a top view of the antenna mounting arrangement used by the Ericsson and Bell systems;
FIG. 18 is a top view of the antenna mounting arrangement used by the Motorola system;
FIG. 19 illustrates transposition of frequency groups to avoid circumstances in which the received level of an adjacent channel may greatly exceed that of the desired channel in embodiments of the present invention;
FIG. 20 illustrates a pattern assignment for the allocation of frequency groups in a 4/12 cell plan utilizing a 1:3 cell splitting scheme;
FIG. 21 illustrates channel group subdivisions and overlay cell coverage restrictions for a 4/12 underlay-4/12 overlay cell pattern with multiple cell sizes;
FIG. 22 illustrates a 7/21 underlay-4/12 overlay cell pattern utilizing reuse partitioning;
FIG. 23 illustrates a control channel allocation plan which has no adjacent control channel frequencies in neighbor cells;
FIG. 24 illustrates a pattern assignment for the allocation of control channels in a 4/12 cell plan utilizing a 1:3 cell splitting scheme;
FIGS. 25-27 show the simulated evolution of a system which initially uses only the standard FCC A Band; and
FIGS. 28-30 illustrate various cell splitting relationships.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 4, a frequency reuse plan according to the teachings of the present invention is shown therein. This plan uses twelve (12) frequency groups in a four (4) site reuse pattern with twenty-six (26) channels per group. The corresponding shift parameters may be seen to be two (2) and zero (0), respectively. Three (3) cells are at each site. The antenna pointing azimuths of each cell are separated by 120° and the cells are arranged in a cloverleaf fashion. Each cell uses 60° transmit antennas and two (2) 60° diversity receive antennas with the same pointing azimuths. Each cell is approximated by the shape of a hexagon.
Because of the use of twelve (12) frequency groups in a four (4) site reuse pattern and because of the cloverleaf arrangement of the cells, the plan according to the present invention and shown in FIG. 4 will, and for clarity and convenience, hereafter be identified as a 4/12 Cloverleaf Cell Plan.
To fully understand the capabilities of the present invention and the advantages it offers over the prior art, it is useful to consider traffic capacity, carrier-to-interference performance, and uplink system gain, each of which will be discussed below.
The three major blocking formulas, Poisson, Erlang B and Erlang C, differ in the basic assumptions made with regard to the behavior of calls failing to find an idle channel. With specific reference to the Poisson blocking formula, calls are willing to wait no longer than their intended or average holding times. If a channel becomes idle before the holding time expires, the call will seize it and use it for the remaining part or duration of its holding time. With respect to the Erlang B blocking formula, blocked calls which fail to find an idle channel immediately are not willing to wait and abandon the call immediately. Finally, with respect to the Erlang C blocking formula, blocked calls are willing to wait an indefinite period to obtain an idle channel.
It is common practice in the cellular industry to assume a loss system, that is, all blocked calls are cleared, when dimensioning the number of channels required per cell in a system. Therefore, the Erlang B blocking formula with a designed channel blocking probability of 2% is used as the standard.
With the above understandings, Table 1 below illustrates the traffic capacity per site for the frequency reuse plans discussed in the description of related art section as well as the reuse plan according to the present invention. The comparison illustrated in Table 1 assumes use of the Erlang B blocking formula with a blocking probability of 2%, 312 available voice channels, equivalent site coverage areas of 31.2 square kilometers, ideal site locations, and ideal cell boundaries.
TABLE 1__________________________________________________________________________FREQUENCY FREQUENCY CHANNELS CAPACITY/SITE CAPACITY/SITEPLAN GROUPS PER SITE (ERLANGS) (ERLANGS/SQ KM)__________________________________________________________________________ERICSSON 7/21 21 44.6(3 × 14.9) 26.7 0.86ERICSSON 4/12 12 78.0(3 × 26) 55.2 1.77BELL 7/21 21 44.6(3 × 14.9) 26.7 0.86MOTOROLA 4/24 24 78.0(6 × 13) 44.4 1.42__________________________________________________________________________
From Table 1 above it may be noted that the Ericsson 4/12 Cloverleaf Cell Plan provides an increase in traffic capacity per site of 106% over both the Bell and Ericsson 7/21 cell plans and 24.4% over the Motorola 4/24 cell plan. In reading the chart it should be noted, however, that a cell must have an integer number of voice channels. Because it is not possible to divide 312 voice channels into an integer number between 21 cells, the 7/21 cell plans in the comparison uses an average number of voice channels per call.
Based on the foregoing, it should be appreciated that the reuse plan according to the present invention offers tremendous advantages over prior art systems with respect to traffic capacity and therefore the number of sites required to serve a system.
Considering channel utilization of the respective systems, the relationship of channel group size vs. channel utilization for the different frequency reuse plans is shown in FIG. 5. The channel utilization shown in FIG. 5 has been calculated using the formula: "channel utilization (%)" equals "traffic capacity per cell" divided by "number of channels per call".
Examining FIG. 5, it may be noted that the channel utilization of the Ericsson 4/12 cell plan exceeds that of the Bell and Motorola cell plans by 10% and 13%, respectively. This increase is accomplished by utilizing a more efficient channel allocation scheme, that is, a larger number of voice channels per frequency group. Thus, with respect to channel utilization, the frequency reuse plan according to the teachings of the present invention constitutes a marked improvement in the art.
Carrier-to-Interference performance will now be considered. Co-channel interference and a multi-path fading environment has been evaluated heretofore in at least one subjective testing program. The results of this program showed that a majority of the listeners consider the transmission quality of the voice channel to be good or excellent at a C/I of 17 dB. At 17 dB C/I, an optimized cellular system will provide voice quality equal to that of a toll call off the public telephone network.
A goal, therefore, of cellular network system designers is to provide acceptable voice quality uniformly throughout the service area. Due to the direct relationship between C/I performance, system capacity and system cost, a system operator usually specifies a required transmission quality for X percent of the subscribers rating the call quality good or better for Y percent of the coverage area.
It may be noted that a C/I ratio of greater than 12 dB is considered to be required for both quality voice conversation as well as bit error rate ("BER") performance within data transmission, synchronization and recognition for frequency modulated systems which use companders, limiters, and base station receive diversity.
A comparison of the C/I performance of the prior art reuse plans and the reuse plan according to the present invention are shown in FIG. 6 which illustrates accumulative probability distribution curves. The evaluation of the C/I performance for the different frequency reuse plans assumes antennas of 120° for Bell and 60° for the two Ericsson and one Motorola systems. Antenna heights in all cases are assumed to be 50 meters. The propagation model employed in the Okamura/Hada, flat earth with no effect from the radio horizon. Site positions are assumed to be ideal as are the cell boundaries. The number of interferers was in all cases six (6). Finally, the effective radiated power was assumed to be equal for both the target and interfering cells.
The distribution curves illustrated in FIG. 6 were generated from the data illustrated in FIGS. 7-10 which show the position and level distribution of the predicted C/I values in the respective cells.
In examining FIG. 6, as well as FIGS. 7-10, it should be noted that the probability distribution curves and C/I predictions are predicted averages and do not include the effect of log-normal fading on the radio signal.
With respect to cell-site position tolerance, the level and distribution of the C/I ratio desired in a cellular system impacts on the position tolerance for locating cell sites. The Ericsson 7/21 cell plan design, for example, permits the cell site to be positioned up to one quarter of the nominal cell radius (15% of the site-to-site distance) from the ideal site location.
The assignee of the present invention has made a limited analysis of the cell-site position tolerance for the cell plan according to the present invention. The results of this analysis are shown in FIGS. 11-13. This analysis focused on the position tolerance which would provide an equivalent C/I distribution to the Bell 7/21 cell plan with an object site located 15% of the site-to-site distance from the nominal site position. The cell-site position tolerance was found to be more than 25% of the site-to-site distance in the 4/12 cell plan for equivalent C/I performance to the reference Bell 7/21 cell plan. However, the C/I distribution for a cell site in the 4/12 cell pattern located 25% of the site-to-site distance off grid is marginal. Therefore, a more conserative site position tolerance of 15% of the site-to-site distance is recommended for inclusion in preferred embodiments of the present invention. Adherence to this position tolerance will provide for a more favorable C/I distribution in the system. In considering the data shown in FIGS. 11-13, it may be noted that the site-to-site distance was used in the analysis due to the differing cell radii for the Bell 7/21 and Ericsson 4/12 cell plans.
Based on the foregoing, it should be appreciated that the cell plan according to the teachings of the present invention offers significant advantages relating to traffic capacity and C/I performance. It also offers significant advantages with respect to uplink system gain, as is discussed immediately below.
The uplink system gain is defined as the sum of the base station receive antenna gain, the diversity gain, and the relative distance gain in the mobile-to-base path. The diversity gain is a function of the incidence angle and the correlation coefficient of the signal received at the base station. That is: (Uplink Gain)=(Antenna Gain)+(Diversity Gain)+(Distance Gain).
The comparison of the four frequency reuse plans discussed herein has been undertaken. Before discussing the results of this comparison, it is important to note a number of assumptions that were made. A first assumption was that path loss is proportional to 39 log r, where r is the distance from the base station to the mobile. A second assumption was that the mobile involved in the comparison is located at the relevant cell boundary at an incidence angle to the base station of 0° to 60°. Third, with respect to the Ericsson and Motorola cell plans, the receive antenna gain for the 60° antennas is 17 dB, and further, the insertion loss (1 dB) associated with the use of duplex filters in the Motorola cell plan is subtracted from the receive antenna gain. It was also assumed that the receive antenna gain for the 120° antennas used in the Bell cell plan is 14 dB. Additionally, theoretical diversity gain for the Ericsson and Bell cell plans was assumed. Theoretical diversity gain for the Motorola cell plan minus the effect of unequal gain branches due to the 60° offset of receive antenna pointing azimuths, and a higher correlation of received signals due to a reduced antenna separation (see FIGS. 17 and 18) was assumed. Finally, a 30 meter tower with a triangular mounting platform which has standard 5 meter faces was also assumed. The antenna mounting arrangements for each cell plan shown and discussed above are shown in FIGS. 17 and 18. It should be noted that the distance gain for each cell plan is a relative value. The value is referenced to the Ericsson cell plan for a mobile located at the cell boundary with an incidence angle of 0°.
FIGS. 14 through 16 show the cell geometry and relative receive antenna gain for incidence angles of 0°, 30°, and 60° for the Ericsson, Bell and Motorola cell plans, respectively.
Based on the foregoing, an uplink system gain comparison was made and the results of that comparison are shown in Table 2 below.
TABLE 2__________________________________________________________________________CELL INCIDENCE GAIN(Db) GAIN(dB) GAIN(dB) GAIN(dB)PLAN ANGLE ANTENNA DIVERSITY DISTANCE TOTAL__________________________________________________________________________ERICSSON 0° 17 10 0 27 30° 14 10 2 26 60° 8 9 11 28BELL 0° 14 8 2 24 30° 13 8 4 25 60° 11 7 2 20MOTOROLA 0° 16 7 4 27 30° 13 10 2 25 60° 16 7 4 24__________________________________________________________________________
It should now be appreciated that the frequency reuse plan according to the present invention offers excellent traffic capacity, carrier-to-interference performance, and uplink system gain characteristics. It is now appropriate to discuss implementation of an Ericsson 4/12 Cell Plan. Such implementation is discussed immediately below with special reference to frequency planning aspects, voice channel assignment aspects, control channel assignment aspects, retune scheme aspects, and cell splitting aspects, each which topic is appropriately headed.
IMPLEMENTATION OF AN ERICSSON 4/12 CELL PLAN
The Ericsson 4/12 cell plan may be implemented in an existing system and frequency plan or during the initial system planning and design of a new system.
Frequency Planning
Optimal frequency planning requires that channel assignment and channel deployment in cells be based upon required cell capacity and C/I considerations. The degree of foresight with which the channel sets are defined and used can affect the system's transmission quality, cost, and ease of adaptation of growth.
Voice Channel Assignment
The Ericsson 4/12 cell plan uses four (4) repeated cell designators, with each designator divided into three (3) frequency groups. These three (3) frequency groups, each assigned to an appropriate sector at a site, may contain 1/12 of the total number of a system's allocated voice channel frequencies. The 4/12 frequency groups are illustrated in Table 3 for the standard FCC a Band. The frequency group allocation for the FCC Extended Band and TACS may be derived in a similar manner as outlined in Table 3 below:
TABLE 3__________________________________________________________________________A1 B1 C1 D1 A2 B2 C2 D2 A3 B3 C3 D3__________________________________________________________________________312 311 310 309 308 307 306 305 304 303 302 301300 299 298 297 296 295 294 293 292 291 290 289288 287 286 285 284 283 282 281 280 279 278 277276 275 274 273 272 271 270 269 268 267 266 265264 263 262 261 260 259 258 257 256 255 254 253252 251 250 249 248 247 246 245 244 243 242 241240 239 238 237 236 235 234 233 232 231 230 229228 227 226 225 224 223 222 221 220 219 218 217216 215 214 213 212 211 210 209 208 207 206 205204 203 202 201 200 199 198 197 196 195 194 193192 191 190 189 188 187 186 185 184 183 182 181180 179 178 177 176 175 174 173 172 171 170 169168 167 166 165 164 163 162 161 160 159 158 157156 155 154 153 152 151 150 149 148 147 146 145144 143 142 141 140 139 138 137 136 135 134 133132 131 130 129 128 127 126 125 124 123 122 121120 119 118 117 116 115 114 113 112 111 110 109108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1__________________________________________________________________________
Through design of a mobile telephone system must include measures to limit not only co-channel interference, but adjacent channel interference as well. Although receive filters at both the cell site and mobile unit significantly attenuate adjacent channel signals, it is advisable to avoid circumstances in which the received level of an adjacent channel may greatly exceed that of the desired channel. This design goal is accomplished in the Ericsson 4/12 cell plan by eliminating the use of adjacent frequencies in neighbor cells by transposing the D2 and D3 frequency groups in the voice channel allocation plan as shown in FIG. 19.
Voice Channel Assignments For Split Cell Sites
The pattern assignment for the allocation of frequency groups in a 4/12 cell plan utilizing a 1:3 cell splitting scheme discussed further below is shown in FIG. 20.
Underlay-Overlay Cell Concept--Multiple Cell Sizes
The underlay-overlay cell concept states that in a region where cells of multiple cell sizes are present, the cellular pattern may be viewed as the superimposition of a small-cell (overlay) pattern on top of a large-cell (underlay) pattern. The channel group assigned to any cell must be subdivided into a large-cell (underlay) group and a small-cell (overlay) group to meet the required C/I objectives in the system. The subdivision of a channel group into large and small-cell groups is governed by the channel requirements of each cell to meet traffic requirements.
The coverage area of the small-cells resident at the sites also servicing a large-cell coverage area must be restricted to ensure an appropriate small-cell reuse distance. This small-cell coverage restriction will maintain the D/R reuse distance in the system, thus allowing the use and deployment of additional voice channels in the large-cell pattern to increase traffic capacity.
FIG. 21 illustrates channel group subdivisions and overlay cell coverage restrictions for a 4/12 underlay-4/12 overlay cell pattern with multiple cell sizes.
Underlay-Overlay Cell Concept--Reuse Partitioning
The frequency planning technique of reuse partitioning is defined to be the coexistence of two reuse patterns, operational on a per cell basis, in a system.
Given that the overlay cell has a reduced cell radius, its assigned frequency group may have a reduced co-channel reuse distance and still maintain an equal D/R ratio to that of the underlay cell pattern. The voice channels allocated to the overlay cells may then be rearranged into channel groups which conform to the overlay cell reuse pattern. Thus, a two tier reuse scheme is produced and the C/I performance of the underlay cell pattern is still maintained throughout the system.
FIG. 22 illustrates a 7/21 underlay-4/12 overlay cell pattern utilizing reuse partitioning.
Supervisory Audio Tone
AMPS and TACS system employ a continuous out-of-band modulated audio tone known as the supervisory audio tone (SAT) for call supervision purposes.
The optimal allocation of the three (3) SATs at 5970, 6000, and 6030 Hz, will multiply the reuse distance ratio for supervision by the square root of 3.
This allocation scheme provides for an increased supervision reliability by reducing the probability of misinterpreted interference (co-channel or adjacent channel) both in the land-to-mobile and mobile-to-land path.
The pattern assignment for the supervisory audio tone in the Ericsson 4/12 cell plan is shown in FIG. 19. The co-channel reuse distance ratio multiplier of square root of 3 times D for supervision is also shown.
Control Channel Assignment
Control channels in the Ericsson 4/12 cell plan are assigned in a standard 7/21 cell pattern. This pattern assignment ensures system reliability during system access. FIG. 23 illustrates a control channel allocation plan which has no adjacent control channel frequencies in neighbor cells. It should be noted that the channel spacing between voice and control channels should be maintained at a frequency separation compatible with the combining equipment being used. This separation should be verified on a per cell basis because of the use of a 7/21 cell pattern for control channels and a 4/12 cell pattern for voice channels.
Control Channel Assignments for Split Cell Sites
The pattern assignment for the allocation of control channels in a 4/12 cell plan utilizing a 1:3 cell splitting scheme discussed further below is shown in FIG. 24.
Digital Color Code
Cellular systems use a digitally coded forward control channel message format which contains a digital color code (DCC). This DCC is contained in the overhead system parameter words which are transmitted on the forward control channel. The DCC must be verified from the reverse control channel message transmitted by the mobile.
The four (4) DCCs multiply the reuse distance for system access supervision by two (2).
The pattern assignment for the digital color code in the Ericsson 4/12 cell pattern is shown in FIG. 23. The reuse distance ratio multiplier of 2D for DCC assignments is also shown.
Retune Scheme
A retune scheme involves an orderly and sequential process which minimizes intra-system interference during the transition stages of converting from a 7/21 cell plan to a 4/12 cell plan. The retune scheme specifies the order in which the radios at each affected site will be retuned beginning with the core area. Temporary voice channel frequencies will be assigned or appropriate channels will be blocked in the transition region until all sites may be tuned to their final 4/12 frequency assignments. This interim procedure is necessary to ensure an acceptable level of system performance during the retune.
Frequency Plan Evolution
The evolution of existing cellular systems from a 7/21 cell plan to a 4/12 cell plan may be implemented in an orderly fashion by utilizing the underlay-overlay cell concept with the frequency planning technique of reuse partitioning. The coverage radius of the overlay cells will be controlled by software parameters and ERP restrictions to 75% of the underlay cells' radii. The use of the underlay-overlay concept will thus allow the operator to increase capacity globally in the system while still maintaining the C/I performance and reuse distance of a 7/21 cell plan.
The simulated evolution of a system which initially uses only the standard FCC A Band is shown in FIGS. 25-27. The required rearrangement and assignment of voice channels into 7/21 and 4/12 frequency groups which use the FCC extended A Band is shown in Tables 4 to 7 immediately below:
TABLE 4__________________________________________________________________________7/21 FREQUENCY ASSIGNMENTSFrequency GroupA.sub.1 B.sub.1 C.sub.1 D.sub.1 E.sub.1 F.sub.1 G.sub.1 A.sub.2 B.sub.2 C.sub.2 D.sub.2 E.sub.2 F.sub.2 G.sub.2 A.sub.3 B.sub.3 C.sub.3 D.sub.3 E.sub.3 F.sub.3 G.sub.3__________________________________________________________________________352 311 310 309 308 307 306 305 304 303 302 301 300 299 298 297 296 295 294 293 292291 290 289 288 287 286 285 284 283 282 281 280 279 278 277 276 275 274 273 272 271270 269 268 267 266 265 264 263 262 261 260 259 258 257 256 255 254 253 252 251 250249 248 247 246 245 244 243 242 241 240 239 238 237 236 235 234 233 232 231 230 229228 227 226 225 224 223 222 221 220 219 218 217 216 215 214 213 212 211 210 209 208207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192 191 190 189 188 187186 185 184 183 182 181 180 179 178 177 176 175 174 173 172 171 170 169 168 167 166165 164 163 162 161 160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 . . .__________________________________________________________________________
TABLE 5__________________________________________________________________________7/21 UNDERLAY CELL FREQUENCY ASSIGNMENTS WITH REUSE PARTITIONINGFrequency Group7A.sub.1 7B.sub.1 7C.sub.1 7D.sub.1 7E.sub.1 7F.sub.1 7G.sub.1 7A.sub.2 7B.sub.2 7C.sub.2 7D.sub.2 7E.sub.2 7F.sub.2 7G.sub.2 7A.sub.3 7B.sub.3 7C.sub.3 7D.sub.3 7E.sub.3 7F.sub.3 7G.sub.3__________________________________________________________________________312 311 310 309 308 307 306 305 304 303 302 301 300 299 298 297 296 295 294 293 292291 290 289 288 287 286 285 284 283 282 281 280 279 278 277 276 275 274 273 272 271270 269 268 267 266 265 264 263 262 261 260 259 258 257 256 255 254 253 252 251 250249 248 247 246 245 244 243 242 241 240 239 238 237 236 235 234 233 232 231 230 229228 227 226 225 224 223 222 221 220 219 218 217 216 215 214 213 212 211 210 209 208207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192 191 190 189 188 187186 185 184 183 182 181 180 179 178 177 176 175 174 173 172 171 170 169 168 167 166165 164 163 162 161 160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 61716 715 714 713 712 711 710 709 708 707 706 705 704 703 702 701 700 699 698 697 696695 694 693 692 691 690 689 688 687 686 685 684 683 682 681 680 679 678 677 676 675674 673 672 671 670 669 668 667 . . . . . . . . . . . . .__________________________________________________________________________
TABLE 6__________________________________________________________________________4/12 OVERLAY CELL FREQUENCY ASSIGNMENTS WITH REUSE PARTITIONINGFrequency Group4A.sub.1 4B.sub.1 4C.sub.1 4D.sub.1 4A.sub.2 4B.sub.2 4C.sub.2 4D.sub.2 4A.sub.3 4B.sub.3 4C.sub.3 4D.sub.3__________________________________________________________________________ 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 11023 1022 1021 1020 1019 1018 1017 1016 1015 1014 1013 10121011 1010 1009 1008 1007 1006 1005 1004 1003 1002 1001 1000999 998 997 996 995 994 993 992 991 . . .__________________________________________________________________________
TABLE 7__________________________________________________________________________4/12 FREQUENCY ASSIGNMENTSFrequency GroupA1 B1 C1 D1 A2 B2 C2 D2 A3 B3 C3 D3__________________________________________________________________________312 311 310 309 308 307 306 305 304 303 302 301300 299 298 297 296 295 294 293 292 291 290 289288 287 286 285 284 283 282 281 280 279 278 277276 275 274 273 272 271 270 269 268 267 266 265264 263 262 261 260 259 258 257 256 255 254 553252 251 250 249 248 247 246 245 244 243 242 241240 239 238 237 236 235 234 233 232 231 230 229228 227 226 225 224 223 222 221 220 219 218 217216 215 214 213 212 211 210 209 208 207 206 205204 203 202 201 200 199 198 197 196 195 194 193192 191 190 189 188 187 186 185 184 183 182 181180 179 178 177 176 175 174 173 172 171 170 169168 167 166 165 164 163 162 161 160 159 158 157156 155 154 153 152 151 150 149 148 147 146 145144 143 142 141 140 139 138 137 136 135 134 133132 131 130 129 128 127 126 125 124 123 122 121120 119 118 117 116 115 114 113 112 111 110 109108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 11023 1022 1021 1020 1019 1018 1017 1016 1015 1014 1013 10121011 1010 1009 1008 1007 1006 1005 1004 1003 1002 1001 1000999 998 997 996 995 994 993 992 991 716 715 714713 712 711 710 709 708 707 706 705 704 703 702701 700 699 698 697 696 695 694 693 692 691 690689 688 687 686 685 684 683 682 681 680 679 678677 676 675 674 673 672 671 670 669 668 667 .__________________________________________________________________________
The retune necessary to implement the simulated 7/21 underlay-4/12 overlay cell pattern with reuse partitioning from the initial system configuration will involve an initial retune of a maximum of three (3) voice channels in the 7/21 underlay cell pattern. This retune will be essential at all cell sites which use the overlay cell frequencies and are within one (1) reuse distance of the overlay cell. The control channel assignments will not be effected by the retune.
Once the capacity of the 7/21 underlay-4/12 overlay cell plan is exhausted, the system operator may then choose to introduce a cell pattern utilizing a 4/12 reuse scheme.
Cell Splitting
Eventually the traffic demand in some cell of a system will reach the cell's traffic-carrying capacity. The process called cell splitting implies the introduction and insertion of new cell sites between existing sites in the cell pattern. The cell splitting process revises cell boundaries so that the area formerly regarded as a single cell can now contain several cells. By reducing the area of each cell, cell splitting allows the system to adjust to a growing traffic demand density without any increase in spectrum allocation.
There are two (2) cell splitting plans currently used in the cellular industry, a 1:3 and a 1:4 cell split. Both of these cell splitting plans may be used in an Ericsson 4/12 cell plan.
1:3 Cell Split
In a 1:3 cell splitting plan, the new sites are located midway between three (3) existing sites. The cell site density is increased by a factor of three (3) by reducing to one-third the nominal area previously covered by each of the existing sites. Each stage of cell splitting requires the channel assignments and antennas in the cell split cluster to be rotated by 30°. This rotation is necessary in order to provide coverage without any gaps or overlaps and consistent C/I performance in the cell split cluster. These relationships are shown in FIGS. 28-30. Utilizing a 1:3 cell splitting scheme will not alter channel assignments at the existing cell sites in the Ericsson 4/12 cell plan.
1:4 Cell Split
In a 1:4 cell splitting plan, the new sites are located midway between two (2) existing sites. The cell site density is increased by a factor of four (4) by reducing to one-fourth the nominal area previously covered by each of the existing sites. Each stage of cell splitting will not require a rotation of antennas. However, each cell split will alter the channel assignments at the existing cell sites.
Based upon all of the foregoing, it should now be clear that the frequency reuse cell plan according to the teachings of the present invention offers tremendous advantages over prior art plans. It should also be clear that a plan according to the present invention may be relatively easy to implement.
It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. While the embodiments shown and described have been characterized as preferred, it will be obvious that various changes and modifications therein without departing from the spirit and scope of the invention.
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A frequency reuse plan for a cellular radio communications system includes a plurality of antenna sites which implement twelve groups of frequencies among four antenna sites. The same frequencies are reused by other groups of four antenna sites. Each antenna site serves three hexagon shaped cells arranged in a clover-leaf shaped pattern by three groups of antennas, each of which group is separated by a pointing angle of 120 degrees.
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This application is related to application Ser. No. 11/215,276, filed on Aug. 30, 2005, now issued as U.S. Pat. No. 7,265,404, which is herein incorporated, by reference, in its entirety.
FIELD OF THE INVENTION
The invention relates to the general field of magnetic tunnel junctions (MTJs) with particular reference to the bottom electrode located between them and the inter-layer dielectric (ILD) of an integrated circuit.
BACKGROUND OF THE INVENTION
Magnetoresistive Random Access Memory (MRAM), based on the integration of silicon CMOS with Magnetic Tunnel Junction (MTJ)s, is a major emerging technology, highly competitive with existing semiconductor memories (SRAM, DRAM, Flash etc). The MTJ consists of two ferromagnetic layers separated by a thin dielectric layer. Magnetization of the two ferromagnetic layers can be arranged to be in either parallel (low resistance) or anti-parallel (high resistance) magnetization states, representing “1” and “0” respectively,
The MTJ memory cells are usually inserted at the back end of a standard CMOS process. The high-speed version of MRAM architecture consists of a cell with an access transistor and a MTJ (1T1MTJ) in the array. The MTJ element is formed on top of the bottom conductor line, which is used to connect the base of the MTJ to the access transistor. Switching of the free layer magnetization in the MTJ device is accomplished by applying currents to orthogonal conductor lines.
The conductors are arranged in a cross-point architecture that provides the field for selectively switching each bit. One line (bit line) provides the field parallel to the easy axis of the bit, while another line (write word line) provides the perpendicular (hard axis) component of the field. The intersection of the lines generates a peak field that is engineered to be just above the switching threshold of that MTJ. For high performance MTJ devices, the separation between the write word line (bit line) and MTJ free layer is made as small as possible.
In a read operation, the read word line (RWL) is selected, and the transistor is turned on. This causes the MTJ device to be connected to ground. At this time, a sense current passes through the BL-MTJ-BE and to ground. The resistance of the MTJ device is low when the MTJ is storing a 1 and high when it is storing a 0.
Referring now to FIG. 1 a , shown there is tantalum hard mask 15 which will be used to separate MTJ sheet stack 16 into individual devices, each resting on a bottom electrode that comprises material from layer 17 which rests on SiN ILD 11 . Also seen (though not relevant to the invention) are vias 18 . In FIG. 1 b , layer 16 has been patterned into individual MTJ devices 4 , with Ta mask 15 having been partly consumed during the etch operation. In FIG. 1 c bottom electrode layer 17 has also been patterned into individual electrodes. However, in the course of making certain that said electrodes are truly electrically isolated one from another, ILD layer has been over etched so that its top surface has been partly eroded, as symbolized by its being shown as a broken line in the figure.
Reactive ion etching (RIE) has been preferred over IBE (ion beam etching) as the method for etching layer 17 . However, vertical features created by IBE always have an extended slope on the edge, which not only could creates electrical shorting problems but also limits further reduction of line width and make it impossible to make very high density IC device. In general, RIE is considered a better approach to creating well-defined three dimensional micro-features but there are several major problems currently associated with the RIE process:
(I) The uncontrollable over etch mentioned above is due to the lack of etching selectivity between the bottom electrode and the ILD. FIG. 2 illustrates the structure of layer 17 in greater detail—immediately on ILD 11 is TaN layer 12 on which is alpha tantalum layer 13 . Layer 14 comprises a second TaN layer.
(2) This etching process always results in a large amount of re-deposition all over the surface of the device due to the non-volatility of the reaction products.
(3) The MTJ will experience two etching processes (first in its own etch and then during the BE etch). This not only affects the MTJ's overall dimensions, but also results in serious damage to the edge of the MTJ's tunnel barrier layer.
A routine search of the prior art was performed with the following references of interest being found:
U.S. Pat. No. 6,974,708 (Horng et al) discloses OSL on top of the bottom electrode.
U.S. Pat. No. 6,703,654 (Horng et al) teaches a NiCr/Ru bottom electrode.
U.S. Pat. No. 6,960,48 (Horng et al) discloses a bottom electrode of /NiCr/Ru/α-Ta.
U.S. Patent Application 2005/0254293 (Horng et al) teaches layers comprising NiCr/Ru/αTa.
U.S. Patent Application 2005/0016957 (Kodaira et al), the Anelva Co., shows dry etching using CH 3 OH.
U.S. Patent Application 2006/0002184 (Hong et al) teaches bottom electrodes of NiCr/Ru/Ta or NiCr/Ru/α-TaN.
Other references, supplied by the inventor, are:
1. S. Tehrani et. al. “Magnetoresistive Random Access Memory using Magnetic tunnel junction” Proceeding of the IEEE. Vol. 91, p 703-712, 2003.
2. C. Horng et. al. HTO3-022 “A novel structure/method to fabricate a high performance magnetic tunneling junction MRAM”. Magic touch and NiCr/Ru/alpha-Ta.
3. “Nanoscale MRAM elements” (including an extensive review of RIE), —S. J. Peraton and J. R. Childress (IBM and U of F).
SUMMARY OF THE INVENTION
It has been an object of at least one embodiment of the present invention to provide a process for forming a bottom electrode for an MTJ stack on a silicon nitride substrate in such a way as to minimize any possible surface damage to said substrate.
A further object of at least one embodiment of the present invention has been that said substrate also serve as an ILD of an associated integrated circuit and that said ILD have a thickness no greater than about 500 Å thereby facilitating it proximity to a word line of said integrated circuit.
Another object of at least one embodiment of the present invention has been that said bottom electrode have good electrical conductance.
Still another object of at least one embodiment of the present invention has been that said MTJ stack have vertical, or near vertical, sidewalls and be spaced no more than about 0.3 microns from neighboring MTJ stacks.
Yet another object of at least one embodiment of the present invention has been that said process not damage the edges of the tunnel barriers of said MTJ stacks.
These objects have been achieved by including a layer of ruthenium as one of the layers that make up the bottom electrode. The ruthenium serves two purposes. First, it is a good electrical conductor. Second, it responds differently from Ta and TaN to certain etchants that may be used to perform RIE. Specifically, ruthenium etches much more slowly than Ta or TaN when exposed to CF 4 while the reverse is true when CH 3 OH is used. Furthermore, silicon nitride is largely immune to corrosion by CH 3 OH, so removal of a ruthenium layer at, or near, the silicon nitride surface can be safely performed.
This differential etch behavior allows an included layer of ruthenium to be used as an etch stop layer during the etching of Ta and/or TaN while the latter materials may be used to form a hard mask for etching the ruthenium.
A problem of the prior art has been the relatively poor adhesion of ruthenium to silicon nitride. This problem has been overcome by inserting a bilayer of NiCr on TaN as the ‘glue’ between the Ru and the SiN.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a - 1 c show the prior art process for forming a bottom electrode for an MTJ stack.
FIG. 2 illustrates the layer structure of an MTJ bottom electrode of the prior art.
FIG. 3 illustrates the layer structure of an MTJ bottom electrode as used in the first embodiment of the present invention.
FIG. 4 shows the structure seen in FIG. 3 after CF 4 etching during which the Ru layer acts as an etch stop.
FIG. 5 shows the structure seen in FIG. 4 after CH 3 OH etching to remove Ru with minimum corrosion of the SiN substrate.
FIG. 6 shows the starting point for the process of the second embodiment of the invention.
FIG. 7 illustrates a key feature of the second embodiment, namely a protective coating that is partly consumed during etching of the alpha tantalum portion of the bottom electrode,
FIG. 8 illustrates the patterning of the protective coating prior to etching down to the level of the ruthenium.
FIGS. 9 and 10 show the final process steps whereby the SiN substrate on which the bottom electrodes lies suffers minimal corrosion after it is exposed and, furthermore, an amount of the protective coating is still present and is thus able to provide permanent protection to the structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention discloses a novel bottom conductor layer structure that is smooth, flat, and has low resistance. In the first embodiment, the bottom conductor layer structure is NiCr30/Ru20/α-Ta120/TaN150. In the second embodiment, the bottom conductor layer structures is typically TaN/NiCr3/Ru30/α-Ta120/TaN150. The total thickness of these bottom conductor structures is 300 Å (as in the prior art). RIE of these bottom conductor layers is first achieved using an etchant of the CF 4 type to remove the top TaN/Ta layer, which is followed by an etchant of the CH 3 OH type to etch the ruthenium.
In MTJ structures, topological roughness of the magnetic layers causes ferromagnetic coupling (Neel coupling) to shift the hysteresis loop. To minimize this inter-layer coupling effect, it is critical to form the MTJ stack on a flat/smooth bottom conductor. An example of a MTJ configuration that results in a high performance MTJ is:
SiN/TaN/NiCr45/Ru100/Ta150/S.E./NiCr5O/MnPt150/CoFe20/Ru7.5/CoFeB21/AlOx(10-15)/NiFe35/CAP.
|<BE<∥<MTJ stack>|
where S.E.=sputter etch
It is known that Ta formed on top of Ru grows in its a low resistance alpha-Ta phase. The high performance MTJ is formed on top of NiCr50/Ru100/Ta150 bottom conductor. The disclosed NiCr30/Ru20/Ta100/TaN150 bottom conductor of this invention is very flat and smooth (typically having a roughness value less than about 2 Å). The TaN150 cap is used here to protect Ta from oxidation. For the process to yield a high performance MTJ, this TaN cap is sputter-etched to a 30 Å thickness of the exposed TaN top layer.
When using a photoresist mask, the etching selectivity for Ta (TaN)/Ru by CF 4 -RIE is around 10. Thus in the process of using RIE to pattern the NiCr30/Ru30/Ta100/TaN150 bottom conductor, the top Ta/TaN is subjected to CF 4 gas chemistry which is largely ineffective at the Ru surface. After photoresist strip, the etchant is then changed to CH 3 OH to etch the remaining Ru/NiCr. Ru etch rate is about same as SiN and NiCr etch rate is about 0.5 of SiN. Since the NiCr/Ru seed layer is much thinner than ILD SiN (50 Å vs 300 Å), even with a 100% over-etch of the Ru30/NiCr30 layers, over-etching into the SiN would amount to less than 50 Å. In contrast, for CF 4 -RIE of the TaN501Ta100/TaN150 (as used in the prior art), a 100% over-etch would result in the removal of over 300 Å of the SiN ILD.
For the first embodiment, as an alternative to the use of NiCr as a ‘glue’ layer, a special treatment of the SiN substrate surface may be used instead:
Sputter-clean SiN/OSL/Ru30/α-Ta120/TaN150
where OSL stands for oxygen surfactant layer. When OSL is used to treat the SiN surface, SiOxyNitride/RuO is formed at the SiN/Ru interface which then promotes good adhesion.
We now provide a description of the processes used to manufacture the two embodiments of the invention:
1 st Embodiment
Referring now to FIG. 3 , the process starts with sputter cleaning of the surface of substrate layer 11 , followed by depositing thereon layer of NiCr 10 onto which is deposited ruthenium layer 31 to a thickness between about 20 and 30 Angstroms. This is followed by the deposition, to a thickness between about 100 and 200 Angstroms, of alpha tantalum layer 32 (on ruthenium layer 31 ). Next, tantalum nitride layer 12 is deposited on layer of alpha tantalum 32 (to a thickness between about 100 and 150 Angstroms).
Now follows a key feature of the invention which is the process used to etch the bottom electrode sheet (layers 12 / 32 / 31 / 11 ) into individual bottom electrodes without, at the same time, significantly penetrating silicon nitride substrate 11 . This is accomplished in two main steps, as follows:
Referring now to FIG. 4 , photoresist mask 41 , that defines the required multiple electrode shapes, is formed on the upper surface of layer 12 . Then, a first reactive ion etching step is performed, using as the etchant one of several possible gaseous compounds of carbon and fluorine, such as CF4, CHF 3 etc., with CF 4 being preferred. Etching of all unprotected areas now proceeds at a rate of about 80 nm/min. and layers 12 , and 32 are successively removed (where there is no photoresist). When however, layer 31 of ruthenium becomes exposed, the etch rate falls off substantially—typically by a factor of about one 10 th , at which point reactive ion etching may be terminated “at leisure” with no danger of etching through ruthenium layer 31 and penetrating silicon nitride substrate 11 . The appearance of the structure is now as shown in FIG. 4 with arrow 42 pointing to the region of separation between two individual bottom electrodes.
Now moving to FIG. 5 , all remaining photoresist has been removed. At this point a second reactive ion etching process is initiated. In this case the etchant used is one of several possible gaseous compounds of carbon, oxygen, and hydrogen, such as CH 3 OH, CO+NH 3 , C 2 H 5 OH, etc., with CH 3 OH being preferred. No additional photoresist is required. Instead the previously etched layer 12 acts as a hard mask during the etching of layers 31 and 10 . Etching of all exposed ruthenium surfaces now proceeds at a rate of about 8 nm/min. until silicon nitride layer 11 is exposed, at which point the second reactive ion etching process may be terminated, also “at leisure”, with no danger of penetrating silicon nitride substrate 11 by more than about 60 Angstroms. The appearance of the structure is now as shown in FIG. 5 .
2 nd Embodiment
Referring now to FIG. 6 , the process of the 2 nd embodiment starts with sputter cleaning of the surface of SiN substrate layer 11 onto which is deposited layer of tantalum nitride 61 to a thickness between about 20 and 30 Angstroms. This is immediately followed by the deposition (onto the top surface of 61 ) of layer 62 of NiCr to a thickness between about 20 and 30 Angstroms. Note that it is critical for the effectiveness of this embodiment that layers 61 and 62 always be used together. The motivation for this is the excellent adhesion of TaN to SiN, the excellent adhesion of NiCr to TaN, and the excellent adhesion of Ru to NiCr. Furthermore, NiCr is an effective seed layer for Ru so it also serves to minimize the resistivity of Ru layer 63 .
Next, layer 63 of ruthenium is deposited on layer 62 and then alpha tantalum layer 64 is deposited on ruthenium layer 63 . Layers 61 - 64 now constitute a base layer on which MTJ devices can be formed. Seen in FIG. 6 are pinned layer sub-stack 65 , insulator tunneling layer 66 and free layer/capping layers 67 . The individual MTJ devices are formed by etching layers 65 - 67 (under a tantalum hard mask) by means of CF 4 —CH 3 OH, which etching process stops when alpha tantalum layer 64 is reached. The appearance of the structure after the individual MTJ devices have been formed is as illustrated in FIG. 6 .
Referring next to FIG. 7 , following the formation of the MTJ devices they are coated with conformal continuous layer 71 of a material known to protect the MTJ junction during the bottom electrode etch that follows. Suitable materials for this layer include SiO 2 , SiN, and SiN/SiO 2 , with SiO 2 being preferred. Moving on to FIG. 8 , once layer 71 is in place, photoresist layer 81 is applied over the entire surface and patterned so as to define the individual bottom electrodes, following which this pattern is transferred to layer 71 by etching its unprotected areas.
As shown in FIG. 9 , once all photoresist has been removed layer 71 becomes a hard mask suitable for etching alpha tantalum layer 64 . This is accomplished by means of a first RIE process based on one of several possible gaseous compounds of carbon and fluorine, such as CF 4 and CHF 3 , with CF 4 being preferred. It is important to note that the initial thickness of layer 71 is critical as it should be thin enough to provide good spatial resolution of the etched parts but thick enough so that there is always present a sufficient thickness to protect the areas that underlie it. This minimum remaining thickness should be about 600 Angstroms.
When layer 63 of ruthenium becomes exposed, the etch rate falls off substantially—typically by a factor of about 10, at which point first reactive ion etching may be terminated “at leisure” with no danger of etching through ruthenium layer 63 and penetrating silicon nitride substrate 11 . The appearance of the structure is now as shown in FIG. 9 with arrow 92 pointing to the region of separation between two individual bottom electrodes
The remains of layers 64 and 71 now serve as a hard mask for the removal of unprotected areas of ruthenium layer 63 , as well as layers 62 and 61 , by means of a second RIE process. The etchant used in the second reactive ion etching process is one of several possible gaseous compounds of carbon, oxygen, and hydrogen such as CO+NH 3 , CH 3 OH, and C 2 H 5 OH, with CH 3 OH being preferred. Once all exposed ruthenium has been removed, the etch rate drops by a factor of about ⅔ when silicon nitride substrate 11 becomes exposed, at which point the second reactive ion etching process may be terminated with minimal penetration of the silicon nitride substrate and with a non-zero thickness of conformal continuous layer 91 still present. This remnant of layer 91 can now serve as a protective layer for the structure.
In summary, the advantages of the invention include:
(a) It results in a well defined vertical profile for each MTJ
(b) It avoids re-deposition of etching by-products on the device surface
(c) It avoids any extensive over etching of the underlying thin SiN ILD.
(d) it avoids possible exposure of the underlying Cu word line, thereby avoiding Cu corrosion by the etching chemicals
(e) It provides an easily controlled manufacturing scheme for the bottom electrode layer of an MRAM device.
(f) It solves the problem of weak adhesion between the BE and ILD
(g) It provides a BE with good electrical conduction
(h) It protects the exposed MTJ junction during BE etch.
|
Formation of a bottom electrode for an MTJ device on a silicon nitride substrate is facilitated by including a layer of ruthenium near the silicon nitride surface. The ruthenium is a good electrical conductor and it responds differently from Ta and TaN to certain etchants. Adhesion to SiN is enhanced by using a TaN/NiCr bilayer as “glue”. Thus, said included layer of ruthenium may be used as an etch stop layer during the etching of Ta and/or TaN while the latter materials may be used to form a hard mask for etching the ruthenium without significant corrosion of the silicon nitride surface.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a system, method an program product for optimising computer software by the technique of procedure cloning. The term “program product” here means a body of computer code stored by a machine readable storage medium such as a CD Rom or one or more floppy discs, or made available for downloading from a remote computer site. The computer code may be integrated within a compiler and be operable for optimising object or intermediate code formed by the compiler.
2. Related Art
A computer program may comprise a call statement for calling a procedure, function or sub-routine (each referred to hereinafter as a “procedure”) included in the program itself or provided in a separate library of procedures or as a respective separate object file. Often a particular procedure is called several or even many times by statements at respective different “call-sites” within the program.
In most cases, the procedures will be provided with parameters or arguments supplied by the call site.
In order to optimise a computer program under development, the technique known as procedure cloning may be useful. This known technique involves the creation of copies of procedures with specialised values of parameters passed to them at a specific site. For example, given a procedure
void proc(int a, int b);
and a call-site that calls this procedure as:
proc(10,b);
the procedure might be cloned as:
void proc — 1(int b)
where the procedure body is re-computed by setting a=10 at the beginning of the procedure, and propagating this value in the procedure body. The original call then will be replaced as a call to this cloned procedure:
proc — 1(b)
The advantages of procedure cloning is that the cloned specialised procedure may be more efficient and sometimes it may be integrated into the computer code at the relevant call site. In some cases, the specialised procedure may turn out to be a NULL item which is never executed at that call site or it may return a parameter which is a constant. Then, of course, the call statement could be removed.
Another technique useful for software optimisation in conjunction with procedure cloning relates to call graphs. In computer science a graph consists of a collection of vertices or “nodes” joined by lines called ‘edges’. A graph may be used to represent many different situations or problems. A control flow graph is a way of representing the dependencies between items of control flow code in a computer program and code branches to which program flow is directed by the control flow code. Such a graph is formed with a series of branching nodes representing items of control flow code and further nodes for the code branches. Arrows are drawn identifying “edges” or the interfaces between the nodes. The call parameters, i.e. the variables passed to the code branches by the control flow code are often also shown adjacent the arrows. U.S. Pat. No. 5,812,855 to Hiranandani et al discloses a system and method for use in the inter-procedural optimisation of computer software where such call graphs or control flow graphs are used. As disclosed by Hiranandani et al, the use of control flow graphs in conjunction with procedure cloning can assist optimising processes. In particular, the construction of a control flow graph can help to identify a procedure which it would be useful to clone. Thus, in Hiranandani et al, cloning is done by reference to whether a particular node receives calls from an “unknown” call site, i.e. whether the node may be called by a previously compiled item of object code and which is hence unamenable to optimisation.
Even so, it remains the case that procedure calls present a difficult barrier for accurate analysis and optimisation of code. Without care, much information may be lost at a call-site regarding the possible behaviour and values of variables and the object of the invention is to provide a means for ensuring that such loss is minimized whilst enhancing the possibility of creating and using specialised versions of procedure bodies.
SUMMARY OF THE INVENTION
According to the invention, there is provided a method and/or a system for optimising computer software that includes one or more call statements and a procedure which is callable by the or each call statement and which has two or more code branches and control flow code for directing program flow to the code branches. The method comprises the steps of analysing the procedure to identify said control flow code and said code branches, identifying for each said code branch a new procedure containing the respective code branch, recording a list of data entries corresponding to the respective new procedures, each entry comprising a data item identifying the respective new procedure and a data item representative of the branch conditions under which said control flow code directs program flow to the associated code branch, and for the or each call statement, scanning the entries in said list to determine one for which there is correspondence between said branch conditions and call parameters directed to said control flow code by the call statement and modifying the call statement to replace the call to the original procedure by a call to the corresponding new procedure. Similarly the system of the invention comprises respective means for carrying out the steps of the method.
A preferred implementation of the invention is in the form of a program product comprising object code stored on a media such as a CD Rom or a set of floppy discs, or made available for downloading from another computer such as a computer operating as a Website.
Preferably, step (a) of the method comprises constructing a control flow graph for the procedure, the control flow graph comprising a branching node representative of said control flow code and further nodes representing respective ones of said code branches.
Thus, in the description to follow, there is disclosed a technique for cloning procedures based on the control-flow information of the procedure body. The procedure body is analysed and specialised versions of the procedure are created. Then, for each such version, there is stored the conditions on the parameters and global variables that would lead to this specialised version being executed. The <condition, specialised version> pairs are stored as a list. At specific call-sites, the list is scanned in order to determine the strongest of these conditions which can be proved to hold at the call-site. If there is such a condition, the call to the original procedure is replaced by a call to the associated specialised version. A given specialised version can have a NULL body, in which case, the call can be avoided altogether.
This technique breaks down a generalised procedure body into specialised versions, each to be executed under specific circumstances. In addition to the traditional procedure cloning technique, which clones a procedure based on specific parameter values, here cloning can be done on more general conditions (even symbolic).
Specialised versions of procedure bodies may facilitate further analysis and optimisation, as the effect of a call to a specialised procedure clone may be more straightforward to compute than the call to the original version.
Also, creation of smaller procedure bodies can facilitate procedure inlining which might trigger off further optimisation, like constant propagation, elimination of redundant conditional tests, and such.
A possible disadvantage of the technique is the need to beware of code-explosion, since so many copies of the same procedure are created, but this can be dealt with in the same way as code-explosion by inlining is controlled—by defining cost conditions which should be satisfied before a specialisation can be performed.
DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described by reference to the accompanying drawings. In these drawings:—
FIG. 1 is a block diagram of an exemplary computer environment;
FIGS. 2A and 2B are consecutive sections of a flow chart for explaining a method in accordance with this invention; and
FIGS. 3 to 7 are respective program control flow diagrams relating to the FIG. 2 method.
DETAILED DESCRIPTION
FIG. 1 shows one embodiment of a computing environment in which the method of the present invention may be carried out and implementations of the system and program product of the invention.
This embodiment comprises a so-called stand alone computer 1 , i.e. one which is not permanently linked to a network, including a display monitor 2 , a keyboard 3 , a microprocessor—based central processing unit 4 , a hard-disc drive 5 and a random access memory 6 all coupled one to another by a connection bus 7 . The keyboard 3 is operable for enabling the user to enter commands into the computer along with user data. As well as keyboard 3 , the computer may comprise a mouse or tracker ball (not shown) for entering user commands especially if the computer is controlled by an operating system with a graphical user interface.
To introduce program instructions into the computer 1 , i.e. to load them into the memory 6 and/or store them onto the disc drive 5 so that the computer begins to operate, and/or is made able to operate when commanded, in accordance with the present invention the computer 1 comprises a CD-ROM drive 8 for receiving a CD-ROM 9 .
The program instructions are stored on the CD-ROM 9 from which they are read by the drive 8 . However, as will be well understood by those skilled in the art, the instructions as read by the drive 8 may not be usable directly from the CD-ROM 9 but rather may be loaded into the memory 6 and stored in the hard disc drive 5 and used by the computer 1 from there. Also, the instructions may need to be decompressed from the CD-ROM using appropriate decompression software on the CD-ROM or in the memory 6 and may, in any case, be received and stored by the computer 1 in a sequence different to that in which they are stored on the CD-ROM.
In addition to the CD-ROM drive 8 , or instead of it, any other suitable input means could be provided, for example a floppy-disc drive or a tape drive or a wireless communication device, such as an infra-red receiver (none of these devices being shown).
Finally, the computer 1 also comprises a telephone modem 10 through which the computer is able temporarily to link up to the Internet via telephone line 11 , a modem 12 located at the premises of an Internet service provider (ISP), and the ISP's computer 13 .
Thus, a program product according to this invention may comprise a storage medium such as the CD-ROM 9 this having stored a body of computer code for causing the computer 1 to carry out the inventive method. Alternatively, the program product may be implemented as a body of computer code made available for downloading to computer 1 from a computer 14 by a supplier operating or using that computer.
The computer 1 does not have to be in a stand along environment. Instead, it could form part of a network (not shown) along with other computers to which it is connected on a permanent basis. It could also be permanently coupled to or have a temporary link to a so-called intranet, i.e. a group of data holding sites similar to Internet sites or URL's and arranged in the same way as the Internet but accessible only to particular users, for example the employees of a particular company. Instead of modem 10 , the computer 1 could have a digital hard-wired link to the ISP's computer 13 or the computer 1 could itself comprise a permanently connected Internet site (URL) whether or not acting as an ISP for other remote users. In other words, instead of the invention being usable only through the local keyboard 3 , it may be available to remote users working through temporary or permanent links to computer 1 acting as ISP or simply as an Internet site.
The computer software to be optimised could be source code which has been entered into the computer via the keyboard 3 , perhaps over a long period, and stored on the hard disc drive 5 or on another CD-ROM entered in the drive 8 , assuming the drive and the other CD-ROM are capable of re-writing data to the CD-ROM, or on the aforementioned optional floppy disc—disc or tape drive, or on a file server (not shown) forming part of the aforementioned network, or from storage sites within the Internet or the aforementioned intranet.
The optimisation method will now be described first generally and then as a specific algorithm but, in either case, in the form of comments plus some pseudo-code and/or C/C++ language statements. It will be appreciated however that the use of C/C++ language statements is not intended to limit the scope of the invention to that language since the algorithm is readily transferable to other computer languages.
Consider a procedure
int getsomevalue(POINTER*p)
{
int ch;
if(p= =NULL)
ch = 0;
else
{
ELSE_BODY;
}
return ch;
}
consider the following code fragment at the call-site;
if(p==NULL)
{
A;
}
else
{
B;
}
val = getsomevalue(
. . .
. . . some use of the variable val . . .
The method creates two versions of the code:
int getsomevalue_0()//to be called when p == 0
{
return 0;
}
int getsomevalue_1(POINTER(*p)//to be called when p !=NULL
{
ELSEBODY;
Return ch;
}
At the call-site, we can replace the call to the procedure as
if(p==NULL)
{
A;
}
else
{
B;
}
if(p==NULL)
val = getsomevalue_0();
else
val = getsomevalue_1();
. . .
. . . some use of the variable val . . .
Applying the technique of replicating code for eliminating redundant branching, we get:
if(p==NULL)
{
A;
val = 0;//inlining . . .
. . . some use of the variable val, where we can propagate the
value 0 . . .
}
else
{
B;
val = getsomevalue_1();
. . . some use of the variable val . . .
}
Note that in this example we substituted
getsomevalue(p)
with
if(p==NULL)
val = getsomevalue_0();
else
val = getsomevalue_1();
In this specific example, this substitution resulted in further optimisation of the branches; in a case where no benefit is gained by such substitution, we may retain the original version.
The basic steps of the algorithm required for implementing this technique will now be described with references to the flow chart of FIGS. 2A and 2B . The numbered steps refer to the items in the flow chart. FIGS. 2A and 2B relate respectively to the creation of the procedure clones and activities at the call sites.
Creation of Procedure Clones ( FIG. 2A )
Step 1 Construct the control flow graph CFG of the procedure. In addition to the usual fields that the CFG nodes have, we will also maintain a field BRANCH_COND. The reference herein to “construct” in relation to a control flow graph does not necessarily mean forming or displaying an actual visual representation of such a graph. As well known, the graph may be “constructed” in terms of data stored in a computer, for example a series of objects representing respective nodes and edges, or as linked lists, arrays and matrices. Step 2 Set PROCEDURE_CLONE_LIST(P) = NULL; Step 3 Perform a Depth First traversal of the CFG. A DFS, “depth first search”, is well known in computer science in relation to graph analysis. Step 4 While traversing a node N, Perform the cost-analysis to determine whether to proceed producing clones. Step 5 If N is a branch-node and C is the corresponding branch condition. Step 6 If C can be represented as a function only of the formal parameters and the Global variables (value of global vars at the beginning of the procedure call)(this can be determined by data-flow analysis, also performing value-propagations where necessary) - the emphasis is “initial value” Step 7 Emit a new subroutine containing all the nodes in the path from the procedure entry to N, and retaining the remaining portion of the CFG as it is. This procedure would be similar in spirit to creating procedure clones, wherein obvious formal parameters and global values may be suppressed. Step 8 If BRANCH_COND(PARENT(N))=> BRANCH_COND(N)) Take only the “then” portion of the branch Step 9 If (BRANCH_COND(PARENT(N))=>~ BRANCH_COND(N)) Take only the “else” portion of the branch Step 10 BRANCH_COND(N) = BRANCH_COND(PARENT(N).AND. BRANCH_COND(N). Step 11 Create a new <condition, pointer to specialised procedure body> pair and add it to the PROCEDURE_CLONE_LIST Step 12 During this process, obvious optimisations regarding control flow are applied, e.g. if a branch B1 implies a descendent branch B2, then if B2 is in the TRUE arm of B1, we need to traverse only the TRUE arm of B2.
At the Call-Sites ( FIG. 2B )
Step 13
For a given call statement S to a procedure P,
Set CURRENT_CONDITION =
TRUE; CURRENT_INDEX = 1;
Step 14
Scan the PROCEDURE-CLONE_LIST(P) and for each entry
<Ci, Pi>, where Ci is a condition and Pi denotes a pointer to a
specialised procedure body of P,
Step 15
Prove whether Ci holds true in the context of the given call-site
Step 16
If so, verify whether CURRENT_CONDITION implies Ci;
Step 17
If not, set CURRENT_CONDITION = Ci and
CURRENT_INDEX = I;
(basically, find out the strongest condition that holds at this site,
e.g. if both (n<2) and (n<10) hold at a given call-site, we want to
substitute the call to the procedure body corresponding to the
condition n<2.
Step 18
If(CURRENT_INDEX = −1) replace the call to the procedure
P by the version Pi that corresponds to the CURRENT_INDEX
using the standard techniques for replacing call-statements
with calls to clones.
Step 19
Check whether the new procedure can be inlined at the call-site.
A similar algorithm is carried out for the case when a condition is known to be false.
The algorithm will now be described in terms of an example for which FIG. 3 illustrates a control-flow graph. The basic blocks are labelled as Ni,Bi, where Ni represents the node, and Bi represents the branch condition at that node. The left branches are taken when a Bi evaluates to TRUE.
In this example, it is assumed that Node N 2 contains code of the type scanf(“%d”\n”) for a local variable n; and the branch condition B 2 is “if(n>0)”. Hence, no more splitting of the graph can occur in this branch beyond node N 2 .
It is also assumed that the cost-analysis heuristic prohibits the splitting of nodes beyond node N 8 in that branch.
As shown in FIGS. 4 to 7 , the resultant specialised procedures will be:
1. <C 1 , P 1 >
2. <C 2 , P 2 >
3. <C 3 , P 3 >
4. >C 4 , P 4 >
where the Ci's and Pi's are as defined in the respective Figures.
The method described above helps to optimise the way programmers write procedures. It is a common practice for programmers to first check minor conditions on the parameters and then write the bigger procedure body. The method would eliminate calls to these procedures at call-sites, if the required conditions can be proved at the call-site itself. Elimination of a call-site can lead to major optimisations because all the pessimistic assumptions about the aliases in the program created by a procedure call are eliminated as well. Also, elimination of a call-site is beneficial at run-time, since if the procedure had to return without performing any task, the procedure need not be called at all.
For example, for a procedure
void do_something(int m, int n) { if(m<n)return; if(m==n) SLIGHTLY_BIGGER_PROCEDURE_BODY else VERY_BIG_PROCEDURE_BODY }
by applying this technique, if (m<n) can be proved at the call-site during compilation, the call to this function would be eliminated.
If (m==n) can be proved at call-site, we will have a procedure with a small procedure body that can even be inlined.
Also such a step might further benefit the analysis of later parts of the program. An analysis of benchmark routines have shown that a large number of optimisations can be made after applying this step.
Whilst particular preferred embodiments of the invention have been shown and described herein by way of example, it will be understood by persons skilled in the art that modifications, developments and other changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims and equivalents thereof.
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A method, system and program product for optimizing software in which procedure clones are created based on the control flow information for the procedure body. In an example, a control flow graph for a called procedure is constructed and, for a branching node which can direct program flow to two or more code branches of the procedure, respective clones or new procedures are formed one for each code branch. A list containing pointers to the clones and the respective branch conditions for those clones is formed. Then, for each call site, the list is scanned to see if a particular call could be replaced by a call to a clone. Meanwhile, each clone is optimized and this may lead to removal of dead code or the replacement of a particular call statement by a constant.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and hereby claims priority to German Application No. 10 2006 029 926.4 filed on Jun. 29, 2006 and International PCT Application No. PCT/EP2007/055601 filed on Jun. 6, 2007, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an arrangement and a method for identifying persons by recognizing detectable body features. The arrangement is intended to be usable portably.
[0003] Determining the identity of a person, or confirming the claimed identity, is one of the most important security tasks in an information technology context. The intention is to be able to distinguish authorized persons from unauthorized persons. The authenticity of persons, and therefore correspondence of a claimed identity with the real identity, must be verifiable. Besides the authentication of persons with the aid of knowledge, for example of a secret number, or possession, for example of a card, i.e. a temporary mechanism, a person is also intended to be assigned so-called attribute features such as physical properties or behavior patterns, which are directly and in general permanently associated with a person. These attribute features may be examined and determined by biometric methods and systems. So-called biometric recognition is carried out with the aid of measurable body features which are assigned to a particular individual. These features are inseparably associated with a person and do not first need to be assigned to them; they cannot be lost and the person does not need to be able to remember them (like a secret number) and they cannot in general be kept secret i.e. these features are apparent, for example face, fingers. Since these features are not transferable, the identity can be assigned uniquely to a person who has been determined correctly by a biometric method.
[0004] The demand for reliable person identifications is currently increasing significantly. The problem of person identification is occurring ever more frequently in the field of for example e-commerce, in access control systems, in counter-terrorism etc. Although identification by possession, for example of a pass, still serves its purpose, it is however becoming less important in the modern world with its frequent electronic communication. Biometry has for this reason been gaining importance, particularly in recent times, since it relates the person identification to an individual's features which are unique and to some extent unchangeable, or are stable over a long period of time.
[0005] Growing and more complex technologies increasingly require accurate and automated person identification. Access to particular objects can be regulated by particular rights with the aid of person identification. Anyone who has been identified successfully, and therefore accepted, receives the predetermined privileges. When such a method is simpler but also a more reliable, the quality of the person recognition is commensurately better and the acceptance of the biometric method is therefore greater.
[0006] A large number of biometric methods are known, the following currently being the methods discussed most
fingerprint recognition face recognition iris recognition.
[0010] Fingerprint Method:
[0011] This method has been available for about 100 years for identifying persons. It is used predominantly in the field of criminal prosecution. In the IT-based (information technology) automated form, the digital fingerprint method is a biometric method with high recognition power. For recording the fingerprint in automatic fingerprint recognition, special sensors of optical, capacitive, semiconductor-based, thermal or direct optical technology are used. For example, attempts are being made to measure skin impedances with ultrasound sensors.
[0012] Regardless of the nature of the fingerprint recording, the method is always provided with a grayscale image of the finger, i.e. the fingerprint. This image is processed further so that correct matching results (correspondence) can be achieved with the enhanced image. The image processing steps involve for instance reducing the image noise, enhancing the image and detecting the features. The extraction of characteristic traits from the image may be carried out with the aid of various methods. It is possible to record either the entire image, as in global pattern matching, relevant parts thereof or the minutiae of type, position and direction. Comparison of these measured characteristic traits with stored setpoint values shows whether the prints come from the same finger and therefore from one person in particular.
[0013] Face Recognition:
[0014] In biometric face recognition, a person's face is recorded using a camera and compared with one or more previously stored face images. The image is initially digitized, for example in a PC. The recognition software then locates the face and calculates its characteristic properties. The result of this calculation, the so-called template, is compared with the templates (patterns, models) of the stored face images. The exception to this is when the original image is used as a reference image, which is compared against a current original image for the recognition process.
[0015] There are different types of approaches for face recognition, with particular key elements being used. In most face recognition methods, the characteristic features of the facial appearance are determined with the aid of a digitized image. Above all, those features of the face are used which do not change constantly owing to the facial expression, i.e. upper edges of the eye sockets, the regions around the cheekbones and the side parts of the mouth. In principle, comparison of the characteristic facial features with the corresponding reference features is carried out by classical image processing and image analysis methods, for instance, after locating the eyes, calculating the facial features with the aid of a grid network which is placed over the face. One subgroup of biometric face recognition is the so-called eigenface method, which is used above all in the field of person identification. Lastly, there are initial approaches to 3D face recognition.
[0016] Iris Recognition:
[0017] Between the iris (pigmented tissue) and the cornea of the human eye, there are complex connective tissue structures resembling bands and combs. These structures are different in each individual. They even differ in identical twins. Furthermore, they vary little during a lifetime in a healthy eye. The image of the iris, recorded externally by a conventional camera (for example a CCD camera) allows the structures to be recognized and is therefore suitable as a unique recognition feature.
[0018] In individuals with dark eye coloration, however, the structures can be recognized only with difficulty in visible light. Biometric iris recognition systems therefore illuminate the iris from a distance of about one meter with light in the near infrared range, which is virtually invisible to the eye. This penetrates through the “pigment” of the human eye (melanin) better than visible light. A recording of the iris structures can therefore be made for all humans with healthy eyes, without dazzling. From the recorded images, by mathematical methods developed specially for this purpose, a unique data set is formed which serves as a so-called “template” for the biometric recognition.
[0019] The other biometric methods include signature recognition, speech or voice recognition, hand geometry or recognition of the typing behavior on a keyboard.
SUMMARY
[0020] It is one potential object to provide a biosensor and a corresponding method, so that identification features of persons can be recorded rapidly and reproducibly and a simple check can be carried out which is convenient for the person to be tested. The intention is to provide a simple and mobile design, which is inexpensive.
[0021] The inventors realized that person identification can be carried out simply with a sensor which is supplied with exhaled air or with condensate of exhaled air, so-called breath condensate, or with saliva from persons, as a source of identity features or cell material as a measurable sample, and which carries out a DNA analysis, the sensor with its peripherals being mobile. In the sample, there are cells or cell fragments which contain the DNA of the corresponding persons. Analysis of this DNA can be used for identification and recognition of the corresponding person. It is thus possible to ascertain the identity of a person by determination of the DNA from the human cells in the exhaled air condensate of the persons to be verified. This may be subdivided into collection with optional delivery to a biosensor unit, analysis with corresponding comparison with a database and displaying the result. A method for operating the arrangement is likewise provided. The collection of the sample is carried out very simply by blowing into a sample reception system. To this end, a subject is made to blow into a sampler (for example a collection tube with a cold trap) until a sufficient amount of cell material has accumulated.
[0022] The DNA analysis system may be an optical, electrical or microgravimetric DNA biosensor. Depending on the way in which the DNA sensor is equipped, the subsequent cell disruption, the PCR (polymerase chain reaction), hybridization and the detection by fragment analysis of the DNA may be carried out directly on a chip or chip card (i.e. on a so-called “lab on a chip”). On the other hand, these various steps may also be performed outside the detection system—in separate steps, so that only the detection step is carried out with the DNA analysis system. Evaluation electronics are provided, for example in the form of a microcontroller or PDA (personal digital assistant), which carries out both the measurement process control and the evaluation of the sensor data, so that the results can then be delivered directly for visualization.
[0023] DNA fragment analysis may be carried out by capillary electrophoresis or by Southern blot analysis.
[0024] After the DNA fragment analysis, a comparison of the personal data thus obtained is made with an existing database. Person identification can thereby be carried out.
[0025] The advantage of such a method is that it can be constructed simply, and can therefore be implemented as an inexpensive and mobile DNA sensor system. This person identification system can thus be set up very simply at various places, operated in situ and made available to a large group of people.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
[0027] The FIGURE shows a schematic representation of a variant of a person identification system, in which cell material in the exhaled air or in the saliva is analyzed by DNA analytics.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawing, wherein like reference numerals refer to like elements throughout.
[0029] Cell material, which has accumulated on the walls or at the bottom of the sampler by respiratory air and respiratory aerosols condensing out, is removed from the sampler by flushing the system or by suction of the sample and, after cell disruption and the PCR, is delivered directly to the DNA analysis system. Reagents may already be added to the sample. The sample reception system may be used independently of the DNA analysis system, or may be coupled directly to the analysis system.
[0030] The person identification system described above has the following advantages:
very high reliability by DNA analysis, non-invasive method, which is straightforward to handle, high acceptance when using exhaled air or saliva for the examination, in contrast for example to blood samples and swabs, improvement of the person identification in respect of security by DNA analysis, simple compact mobile sensor system, improvement in the practicability of such an examination since it can be carried out rapidly, inexpensive method when using electrical biosensors.
[0038] The persons to be identified 1 blow into a flexible sampling system 2 in order to collect the required cell material from the exhaled air 7 . By continuously blowing, cells or cell fragments are also exhaled by breath aerosols besides or in biological components of the exhaled air 7 . These are deposited on the walls of the sampling system by condensation of the respired air. The blowing into the sampling system must be configured so that the exhalate or saliva contains the required number of cells. This may optionally be done using a controller which determines the collection time or the collection volume. One possible configuration of the sampling system may be a collection tube with a cold trap 3 , so that the exhaled air condensate is already pre-collected, or only a simple small tube without a cold trap. Either this sampling system is flexible and independent of the DNA sensor system, and can therefore be used in a mobile fashion and directly in situ, or it is connected directly to the sensor system 4 .
[0039] After the sampling, the sampling system is coupled to the DNA analysis system and the sample is delivered to the analysis system by flushing or suction. If the sampling system is already coupled to the DNA sensor system 4 in a fixed fashion, the delivery of the sample is carried out by a connected pump or suction device. During the sample transfer 9 , the sample may already be supplemented with reagents which are required for the DNA analysis (for example cell lysis medium).
[0040] The DNA analysis is then carried out by the DNA sensor system. Optical DNA sensors, for example using fluorescence, chemiluminescence, SPR (surface plasmon resonance) or electrical DNA sensors, for example amperometric, potentiometric, or microgravimetric DNA sensors (piezoelectric, quartz micro-balances) may be used for the DNA analytics. A simple and economical configuration of the sensor system can be achieved by employing electrochemical DNA chips. By integrating the complete system, i.e. cell disruption and sample purification, PCR (polymerase chain reaction), fragment analysis, hybridization and signal readout on a so-called “lab on a chip”, a very easily handleable mobile instrument is made available and usable.
[0041] The DNA data thus obtained from the DNA fragment analysis are subsequently compared 10 with a DNA database 5 in order to carry out the identification of the person. Depending on the application range, this database may contain only the DNA data of a selected group of people, or it may be linked with a central database when general person identification is required, for example in security checks at airports. The local database is conventionally stored in the instrument, while access to a central database takes place via a radio connection or via a wired network, for example the Internet. Security of the data matching must be ensured by IT security management, likewise the data protection of the persons. In the drawings, reference numeral 6 represents an output or display.
[0042] The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004).
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A method for identifying people involves breathing respired air into a collector unit, trapping condensate from the respired air in the collector unit, introduction of the condensate by a same introduction to a DNA sensor unit, analysis of the condensate after a cell disruption, comparison of the result the data from a databank and output of the comparison result with analysis of the identity of a person.
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PRIORITY CLAIM
This application is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 13/156,892, filed on Jun. 9, 2011, now abandoned, which is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 11/678,837, filed on Feb. 26, 2007, which issued as U.S. Pat. No. 8,061,913 on Nov. 22, 2011, which is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 11/448,605 filed on Jun. 6, 2006, now abandoned, which is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 10/654,521, filed on Sep. 2, 2003, which issued as U.S. Pat. No. 7,132,206 on Mar. 20, 2007, the entire contents of each of which are incorporated herein by reference.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to the following commonly-owned co-pending patent applications: “BEZEL INTERFACE FOR A CARD LOADING SYSTEM,” U.S. patent application Ser. No. 11/983,771, “CARD LOADING SYSTEM FOR A DATA CARD UNIT,” U.S. patent application Ser. No. 11/983,772, “MACHINE HAVING A CARD PROCESSING ASSEMBLY,” U.S. patent application Ser. No. 13/287,638, and “GAMING DEVICE INCLUDING A CARD PROCESSING ASSEMBLY HAVING VERTICALLY-STACKED CARD HOLDERS OPERABLE WITH THERMALLY-PRINTABLE DATA CARDS AND PORTABLE CARD CHANGEOVER MACHINES,” U.S. patent application Ser. No. 13/290,475.
BACKGROUND
This invention relates generally to gaming printers and more specifically to printers for use in cashless gaming machines that use rewritable cards.
The gaming machine manufacturing industry provides a variety of gaming machines for the amusement of gaming machine players. An exemplary gaming machine is a slot machine. A slot machine is an electro-mechanical game wherein chance or the skill of a player determines the outcome of the game. Slot machines are usually found in casinos or other more informal gaming establishments.
Gaming machine manufacturers have more recently introduced cashless enabled games to the market and these have begun to find wide acceptance in the gaming industry. Cashless enabled games are so named because they can conduct financial exchanges using a mixture of traditional currencies and rewritable cards. Typically, a cashless enabled game has a gaming printer to produce rewritable cards and a rewritable card reader that supports automatic reading of rewritable cards. To coordinate the activities of multiple cashless enabled games, one or more cashless enabled games may be electronically coupled to a cashless enabled game system that controls the cashless operations of a cashless enabled game.
When a player cashes out using a cashless enabled game coupled to a cashless enabled game system, the cashless enabled game signals the system and the system may determine the type of pay out presented to the player. Depending on the size of the pay out, the cashless enabled game system may cause the cashless enabled game to present coins in the traditional method of a slot machine, or the cashless enabled game system may cause a gaming printer in the cashless enabled game to produce a rewritable card for the value of the pay out. The rewritable card may then be redeemed in a variety of ways. For example, the rewritable card may be redeemed for cash at a cashier's cage or used with another cashless enabled game. In order to use the rewritable card in a cashless enabled game, the rewritable card is inserted into a rewritable card reader of another cashless enabled game at a participating casino and the cashless enabled game system recognizes the rewritable card, redeems the rewritable card, places an appropriate amount of playing credits on the cashless enabled game.
Cashless enabled games have found an increasing acceptance and use in the gaming industry, both with players who enjoy the speed of play and ease of transporting their winnings around the casino and casinos who have realized significant labor savings in the form of reduced coin hopper reloads in the games, and an increase in revenue because of the speed of play. Practical field experience with printers used in cashless enabled games has illustrated that there are areas for improvement in the current printer designs and implementation. These areas in need of improvement include methods and means for using rewritable card media for printing of vouchers.
SUMMARY
A rewritable card printer useful as a gaming machine printer for printing vouchers is provided. The rewritable card printer includes a print module coupled to one or more separate card magazines, each having independent card drives. The operations of the print module and one or more card magazines is controlled by a printer controller. Cards may be exchanged between multiple card magazines so that cards can be escrowed, exchanged, or selectively located and retrieved.
The print module may receive as well as dispense cards from and to an external card source so that the card magazines may be replenished without opening up a gaming machine hosting the rewritable card printer. The print module may further include a security device reader that is used to read security features embedded in the cards. The security features may be used to track individual card use and to guard against card duplication and fraud.
In another aspect of the invention, a rewritable card printer includes a print module having a print card drive and a print head with the print module mechanically coupled to a base. The rewritable card printer further includes a card magazine having a card storage location and a magazine card drive with the card magazine coupled to the base such that the magazine card drive and the print card drive may exchange cards. The rewritable card printer has a printer controller electronically coupled to the print module and the card magazine. The printer controller includes a processor and a memory coupled to the processor. The memory has program instructions stored therein, the program instructions for operation by the printer controller of the print module and the card magazine.
In another aspect of the invention, the program instructions further include receiving card information for printing onto a card, generating printable indicia using the card information, and printing onto a rewritable card the printable indicia using the print head.
In another aspect of the invention, the rewritable card printer further includes an erase head with the program instructions further including instructions for erasing the rewritable card using the erase head.
In another aspect of the invention, the rewritable card printer further includes a security feature reader, the program instructions further including reading a security signature from the rewritable card using the security feature reader.
In another aspect of the invention, the rewritable card printer may be removably coupled to an external card magazine for dispensing and receiving cards.
In another aspect of the invention, the rewritable card printer may be programmed using a rewritable card or an external controller.
In another aspect of the invention, the rewritable card printer further includes encryption/decryption means coupled to the printer controller.
In another aspect of the invention, the rewritable card printer further includes a display device coupled to the printer controller.
In another aspect of the invention, the rewritable card printer further includes a card cleaning device coupled to the input module.
In another aspect of the invention, the input module further includes a magnetic strip read/write head. In another aspect of the invention, the input module further includes an optical scanning device.
In another aspect of the invention, the input module further includes means for coupling to a static memory in a rewritable card.
In another aspect of the invention, the program instructions further include: receiving a card for storage; reading card information from the card; erasing the card; storing the card information in a static memory; and storing the card in the card magazine.
In another aspect of the invention, the card magazine further includes the static memory for storage of the card information.
In another aspect of the invention, the base is slidably coupled to a base plate fixedly coupled to a gaming machine.
In another aspect of the invention, the card magazine is slidably coupled to the base.
In another aspect of the invention, the print module is removably coupled to the base by mechanical quick disconnect means and removably coupled to the printer controller by electrical quick disconnect means.
In another aspect of the invention, the card magazine is removably coupled to the base by mechanical quick disconnect means and removably coupled to the printer controller by electrical quick disconnect means.
In another aspect of the invention, the rewritable card further comprises a second card magazine coupled to the base such that the second card magazine's magazine card drive is in communication with the first of the card magazine's magazine card drive.
In another aspect of the invention, the program instructions further include: receiving a request for a card located in the first card magazine; determining the location of the requested card located in the first card magazine; and moving cards from the first card magazine to the second card magazine until the location of the requested card is reached.
In another aspect of the invention, the rewritable card printer further includes an additional card magazine coupled to the base such that the second card magazine's magazine card drive is in communication with the print module's print card drive.
In another aspect of the invention, the program instructions further include instructions for escrowing a card or exchanging a card for another card.
In another aspect of the invention, the print module further includes an embossing detector.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
FIG. 1 is a block diagram of a cashless gaming machine and system in accordance with an exemplary embodiment of the present invention;
FIG. 2 a is an illustration of a rewritable card in accordance with an exemplary embodiment of the present invention;
FIG. 2 b is an illustration of another portion of a rewritable card in accordance with an exemplary embodiment of the present invention;
FIG. 2 c is an illustration of another portion of a rewritable card having a memory in accordance with an exemplary embodiment of the present invention;
FIG. 3 is a block diagram illustrating a security feature employing capacitive inks in accordance with an exemplary embodiment of the present invention;
FIG. 4 is a block diagram of a security feature utilizing an optical signature in accordance with an exemplary embodiment of the present invention;
FIG. 5 is a block diagram of a security feature using randomly deposited radio sensitive fibers embedded in a rewritable card in accordance with an exemplary embodiment of the present invention;
FIG. 6 is a block diagram of the operation of a rewritable card printer in accordance with an exemplary embodiment of the present invention;
FIG. 7 a is a block diagram of a rewritable card printer in accordance with an exemplary embodiment of the present invention;
FIG. 7 b is an architecture diagram of a rewritable card printer employing components having integral controllers in accordance with an exemplary embodiment of the present invention;
FIG. 8 is an isometric view of a rewritable card printer in accordance with an exemplary embodiment of the present invention;
FIG. 9 is an isometric view of a rewritable card printer with the card magazine opened in accordance with an exemplary embodiment of the present invention;
FIG. 10 is a top plan view of a rewritable card printer in accordance with an exemplary embodiment of the present invention;
FIG. 11 a is side elevation view of a rewritable card printer in accordance with an exemplary embodiment of the present invention;
FIG. 11 b is side elevation view of a rewritable card charging process accordance with an exemplary embodiment of the present invention;
FIG. 11 e is a side elevation view of a rewritable card printer with a card magazine having two independent magazine card drives in accordance with an exemplary embodiment of the present invention;
FIG. 11 d is a side elevation view of a card magazine having a plurality of card storage locations serviced by a single card magazine drive in accordance with an exemplary embodiment of the present invention;
FIG. 11 e is side elevation view of a rewritable card printer slidably coupled to a gaming machine in accordance with an exemplary embodiment of the present invention;
FIG. 12 is a process flow diagram of a rewritable card printing process in accordance with an exemplary embodiment of the present invention;
FIG. 13 is a process flow diagram of a card escrowing process used by a rewritable card printer in accordance with an exemplary embodiment of the present invention;
FIG. 14 is a card retrieval process used by a rewritable card printer having companion magazines in accordance with an exemplary embodiment of the present invention;
FIG. 15 is a process flow diagram of a card location process used by a rewritable card printer having multiple card magazines in accordance with an exemplary embodiment of the present invention;
FIG. 16 is a process flow diagram of a card replacement process in accordance with the present invention;
FIG. 17 is a process flow diagram of a programming process using a rewritable card in accordance with an exemplary embodiment of the present invention;
FIG. 18 is a process flow diagram of a card information storage process in accordance with an exemplary embodiment of the present invention;
FIG. 19 is a process flow diagram of a card information retrieval process in accordance with an exemplary embodiment of the present invention; and
FIG. 20 is a stored card status printing process in accordance with an exemplary embodiment of the present invention.
FIG. 21 is a block diagram showing an example external card magazine of the present disclosure communicating with a gaming machine via an external controller.
DETAILED DESCRIPTION
FIG. 1 is a block diagram of a cashless enabled gaming machine coupled to a rewritable card printer in accordance with an exemplary embodiment of the present invention. A cashless gaming system includes a cashless gaming system controller 100 hosted by a system host 102 coupled 104 to one or more cashless enabled games 106 . A cashless enabled game includes a game controller 108 that controls the operation of the cashless enabled game. The game controller is coupled to a rewritable card printer 110 . The cashless enabled game uses the rewritable card printer to write rewritable card media such as rewritable card 114 . The rewritable card printer includes card identification and printing algorithms 113 used in conjunction with rewritable cards. The rewritable card includes the cash-out information for a player.
The rewritable card printer may also be coupled ( 112 ) to the host system and cashless gaming controller. The rewritable card may be redeemed ( 116 ) in a variety of ways. The rewritable card may be redeemed by a human cashier or card reader 122 at a game table 124 , or a human cashier or card reader 126 at a cashier's cage or kiosk 128 , or by a card reader 118 at another cashless enabled game 120 . Redemption is only possible after the rewritable card passes a verification of account information 130 and validation using security features 132 included in the rewritable card.
FIG. 2 a is an illustration of a rewritable card in accordance with an exemplary embodiment of the present invention. The rewritable card shown is produced from commands issued by the cashless enabled game to the gaming printer in response to a player's request to cash-out. The rewritable card 114 includes features such as a validation number, printed in both a human readable form such as a character string 200 and in a machine-readable form such as a bar code 202 , time and date stamps 204 , cash-out amount 206 , casino location information 208 , cashless enabled game identifier 210 , and an indication of an expiration date 212 . Included in the card is a security feature 132 that may take one or more forms as discussed below.
In one rewriteable card media in accordance with an exemplary embodiment of the present invention, one face of the rewriteable card includes a layer of writable and erasable thermally sensitive film. The thermal film becomes opaque at one temperature level but becomes transparent at another temperature. This effect can be used to create a thermally rewritable card.
FIG. 2 b is an illustration of another side of a rewriteable card in accordance with an exemplary embodiment of the present invention. The rewriteable card 114 may also include a read/write magnetic strip 214 for encoding of any of the information described above.
In addition, the magnetic strip may be used to transmit information to the rewritable card printer. For example, the magnetic strip may encode instructions such as configuration flags or programming instructions used to reconfigure or reprogram a rewritable card printer.
FIG. 2 c is an illustration of another portion of a rewriteable card having a static memory in accordance with an exemplary embodiment of the present invention. The rewriteable card 114 may also include a static memory 216 embedded in the rewritable card so that the rewritable card can be used as a “smart” card for encoding of any of the information described above.
In addition, the static memory may be used to transmit information to the rewritable card printer. For example, the static memory may encode instructions such as configuration flags or programming instructions used to reconfigure or reprogram a rewritable card printer.
FIG. 3 is a block diagram illustrating a security feature employing capacitive inks in accordance with an exemplary embodiment of the present invention. A rewritable card 114 may be imprinted with metallic inks to create one or more capacitors in the rewriteable card, The one or more capacitors may be used to create a security feature in the form of a capacitor structure 300 whose capacitance may be detected by a capacitance sensor 302 coupled to the rewritable card. As the card moves across the sensor (as indicated by arrow 304 ) the sensor senses changes in the localized capacitance of the card and generates ( 306 ) a security signature signal 308 corresponding to the structure of the capacitor structure 300 in the rewritable card. This security signature signal may be used to identify each rewritable card used in a cashless enabled gaming system.
FIG. 4 is a block diagram of a security feature utilizing an optical signature in accordance with an exemplary embodiment of the present invention. To use this security feature, a rewritable card 114 includes a structure 400 having a variable optical density or optical reflectivity that is not apparent under normal lighting conditions. However, when a high intensity light, such as a laser beam 402 generated by a laser diode 404 or other laser beam generating device, is transmitted through the rewritable card, a light sensor 406 may detect fluctuations in the intensity of the transmitted or reflected laser beam caused by the structure. If the card is moved past the laser beam (as indicated by arrow 408 ) the moving structure generates a changing light signal that is received by the light sensor. In response to the changing light signal, the light sensor generates ( 410 ) a time varying security signature signal 412 that may be used as a signature to uniquely identify each rewritable card used in a cashless gaming system.
FIG. 5 is a block diagram of a security feature using randomly deposited radio sensitive fibers or inks embedded in a rewritable card in accordance with an exemplary embodiment of the present invention. A rewritable card 114 may include a layer of randomly deposited radio sensitive fibers 500 embedded within the card. An excitor 502 is used to transmit short pulses of radio waves 504 into the layer of fibers. In response to the radio waves, the fibers generate a resultant radio frequency signal 506 that may be detected by a sensor 508 . If the rewritable card is moving (as indicated by direction arrow 509 ) as the fibers are being excited, the sensor receives a time varying radio frequency signal generated by the excited and moving fibers. In response to the time varying radio frequency signal, the sensor generates ( 510 ) a time varying security signature signal 512 that may be used to uniquely identify each rewritable card in a cashless gaming system.
FIG. 6 is a block diagram of the operation of a rewritable card printer in accordance with an exemplary embodiment of the present invention. A rewritable card printer includes a security feature reader 600 for reading a security feature embedded in a rewritable card 114 . The type of security feature reader is dependent on the type of security features used with the rewritable card. The security feature reader supplies the appropriate excitation energy and sensor to generate a security signature signal as previously described.
The rewritable card printer also includes an erase head 602 for erasing a rewritable card prior to printing on the rewritable card. The erase head raises the temperature of the rewritable thermal film to the erasing temperature and any images previously written to the rewritable card are erased.
The rewritable card printer also includes a print head 604 for printing on the rewritable card. The print head raises the temperature of the thermal film on the rewritable card to the writing temperature and indicia are printed onto the rewritable card as a result.
The rewritable card printer also includes an optical scanning device 605 for reading the printed indicia on the rewritable card. The operation of such a device is more fully detailed in U.S. patent application Ser. No. 10/136,897, filed Apr. 30, 2002, the contents of which are hereby incorporated by reference as if stated herein in full.
The rewritable card printer also includes a magnetic strip read/write head 607 for reading from, and writing to a magnetic strip 214 (of FIG. 2 ) on the rewritable card.
The rewritable card printer includes a printer controller 606 operably coupled to the security feature reader. The security feature reader generates a security signature signal 608 that is transmitted to the printer controller.
The printer controller is also coupled to the erase head. The printer controller generates an erase control signal 612 that is transmitted to the erase head. In response to the erase head signal, the erase head heats the rewritable card until all indicia are erased from the rewritable card.
The printer controller is also coupled to the print head. The printer controller transmits print head control signals 616 to the print head. In response to the print head control signals, the print head heats a thermal element for each dot that is to be imaged on the rewritable card. The print head typically creates dot images to a granularity of 12 dots per millimeter, each dot image using a separate thermal element to create a dot image.
The printer controller is also coupled to the optical scanner 605 . As the optical scanner scans the printed indicia on the rewritable card, the optical scanner transmits scanned signals 617 to the printer controller.
The printer controller is also coupled to the magnetic strip read/write. head 607 . The printer controller transmits magnetic strip write signals and receives magnetic strip read signals to and from ( 619 ) the magnetic strip read/write head.
The printer controller may also be coupled to a static memory read/write connector 622 . The printer controller transmits static memory write signals and receives static memory read signals to and from ( 624 ) the static memory read/write head.
In one embodiment of a rewritable card printer in accordance with the present invention, a game controller 108 is operably coupled to the printer controller, The printer controller receives printer control instructions 614 , including card information for writing to the rewritable card, from the game controller. The printer controller may also transmit printer status and card identification signals 610 to the game controller.
FIG. 7 a is a block diagram of a rewritable card printer in accordance with an exemplary embodiment of the present invention. A rewritable card printer 110 includes a printer controller 606 , a print module 702 , and one or more card magazines 704 .
The print module includes a print card drive 706 that moves cards through the print module. The print card drive is reversible such that a card may be fed through the print module in more than one direction by the print card drive. The print card drive includes a card motion sensor 707 for sensing card movement within the print card drive. A more detailed discussion of printer media motion detection within a printer is presented in U.S. patent application entitled “PAPER MOTION DETECTOR IN A GAMING MACHINE”, attorney docket number 50820/FLC/F392 filed Aug. 12, 2003, the contents of which are hereby incorporated by reference as if stated herein in full. The print drive further includes an embossing detector 709 that may be used to sense when an embossed item, such as a conventional credit card, is inserted into the print module. The embossing detector may be a mechanical device, such as a limit switch, that contacts an inserted card and detects any embossing. If an embossed card is inserted into the rewritable card printer, the rewritable card printer may not attempt to write to the card, only read the card.
The print module further includes a security feature reading device 600 for reading any security features included in the card. The print module further includes a print head 604 for writing indicia to the rewritable card and an erase head 602 for erasing the indicia from the rewritable card.
The print module further includes an optical scanning device 605 for scanning the indicia printed onto a rewritable card. The print module further includes a magnetic strip read/write head 607 used to read and write from and to a rewritable card's magnetic strip. The print module is removably and electronically coupled to the printer controller and removably and mechanically coupled to the card magazine.
In operation, the print module receives printer control signals from the printer controller. In response to the printer control signals, the print module scans rewritable cards for the presence and value of any security feature in the rewritable card. As the print module scans the rewritable card, the security feature reading device generates a previously described security signature signal that is transmitted to the printer controller. In addition, the print module thermally prints on the rewritable cards, and thermally erases the rewritable cards, under the control of the printer controller. The print module may also receive a rewritable card from a player and transmit a rewritable card detection signal to the printer controller.
The print module may also include a static memory read/write connector 622 for coupling to a “smart” card having a readable/writable static memory. The printer controller transmits static memory write signals and receives static memory read signals to and from the static memory read/write head.
The one or more of card independently controlled card magazines store rewritable cards and provide the rewritable cards to the printer module on command from the printer controller. Each card magazine may includes one or more magazine card drives 710 for moving cards into and out of the magazine. Each card magazine also includes a card storage area 712 for storage of rewritable cards. In operation, the card magazine receives card magazine control signals from the printer controller. In response to the control signals, the card magazine feeds cards to the printer from the card storage area using the magazine card drive. In response to the card magazine control signals, the card magazine may also receive rewritable cards from the print module and store the rewritable cards in the card storage area. The card magazine may also include one or more card sensors 714 used to detect the number of cards stored in the card storage area. The card sensors sense the quantity of cards stored in the card storage area and transmit card count signals to the printer controller for further processing. The card magazine may also include a read/write static memory 715 for semi-permanent storage stored in the card magazine.
The printer controller include to a main memory 718 by a system information about cards a processor 716 coupled bus 720 . The printer controller also includes a storage memory 722 coupled to the processor by the bus. The storage memory stores programming instructions 113 , executable by the processor to implement the features of a rewritable card printer. The storage memory also includes printer and card information 724 stored and used by the processor. The printer and card information includes information received by the printer controller about the status of the print module and card magazine and also about the status and identity of any cards stored in the card magazines or being operated on by the print module. The types of status information may include an image of a last printed rewritable card as scanned by the optical scanning device and the current status, such as millimeters of advancement, of a card currently in the print module.
The printer controller also includes an Input/Output (I/O) device 726 coupled to the processor by the system bus. The I/O device is used by the printer controller to transmit control signals to the print module and the card magazine. The I/O device may also be used by the printer controller to receive security feature and status signals from the print module and card magazine.
One or more communications devices 728 may be coupled to the system bus for use by the printer controller to communicate with a cashless gaming system host 102 or a game controller 108 (both of FIG. 1 ). The printer controller uses the communication devices to receive commands, program instructions, and card information from the external devices.
In addition, the printer controller may use the communication devices to transmit printer status information to the external devices. Other communication devices may also be used by the printer controller to couple in a secure fashion over a local area network 732 for administrative or other purposes.
Additional communication devices and channels may be provided for communication with other peripheral devices as needed. For example, one communication device may be provided with a local communications port, accessible from an exterior of a gaming machine hosting the rewritable card printer, that a technician may use to communicate with the printer controller during servicing using an external controller 730 . The external controller may communicate with the printer controller using an infrared link, other short-range wireless communication link, are a hard link with an external connector in a secure manner.
The processor may be further coupled to an encryption/decryption module 740 that may be used to encrypt and decrypt messages encoded using the an encryption standard. This enables the printer controller to engage in secure transactions with external devices. The processor may access the display device either as a component through the bus as shown or as an external device through a communications device using a high level communications protocol. In addition, the printer controller may also include program instructions to perform encryption/decryption services as well.
The processor may be further coupled to a display device 742 that may be used to display printer status information or card information. For example, the display may used to display an “as-scanned” version of the most recently printed and scanned card. The processor may access the display device either as a component through the I/O device or as an external device through a communications device.
In operation, the processor loads the programming instructions into the main memory and executes the programming instructions to implement the features of a rewritable card printer as described herein.
As illustrated, the printer controller is shown as being electronically coupled to the print module and card magazine without any mechanically coupling. The printer controller may be mounted in a variety of ways and may be incorporated into various components of either the rewritable card printer or the game hosting the rewritable card printer. For example, the printer controller may be attached to and supported by the print module, the card magazine, or the host game as may be required to mechanically integrate the rewritable card printer into the host game.
FIG. 7 b is an architecture diagram of a rewritable card printer employing components having integral controllers in accordance with an exemplary embodiment of the present invention. A rewritable card printer 110 may be composed of a printer controller 606 that communicates with components and modules of the rewritable card printer using a communications link 749 . The communications link may use either serial or parallel communications protocols to communicate with the components of the rewritable card printer. In this embodiment a print module 750 includes a print module controller 752 coupled to the printer controller. To control the operations of the print module, the printer controller transmits high level commands and status requests to the print module. In response, the print module performs the commands and transmits the requested information.
One or more card magazines 754 may also have integral card magazine controllers that are coupled to the printer controller via the communications link. To control the operations of the card magazine, the printer controller transmits high level commands and status requests to the card magazine. In response, the card magazine performs the commands and transmits the requested information to the printer controller.
The internal architecture of the rewritable card printer may be extended to external devices 758 as well, each having its own internal controller 760 . In this embodiment, the printer controller communicates with the external device using high level commands. In response, the external device performs the commands and transmits any requested information to the printer controller. An example of an external device having its own internal controller includes an external card magazine or cassette used to load cards into, or retrieve cards from, the rewritable card printer.
FIG. 8 is an isometric view of a rewritable card printer in accordance with an exemplary embodiment of the present invention. As illustrated, the rewritable card printer 110 includes a print module 702 and one or more card magazines 704 mechanically coupled on a base 800 . The rewritable card printer includes a front bezel 802 through which a rewritable card 114 may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer as previously described. The card magazine is positioned on the base such that the card magazine's magazine card drive 710 may feed rewritable cards to and receive rewritable cards from the print module as previously described. The print module and the magazine drive are separately mounted to the base and each may separately serviced in the field without affecting the operation of the other. In addition, each component may be removed from the rewritable card printer and replaced without removing the power to the rewritable card printer.
As the print module and card magazine are separately mounted and controllable, the orientation of the print module and card magazine may be altered as needed to suit the mechanical requirements of a host game. For example the distance between the print module and the card magazine may be altered in order to accommodate a shorter printer bay included in a host game.
In one card magazine in accordance with an exemplary embodiment of the present invention, the cards are stored in the card magazine at an angle, up to 90 degrees, relative to the orientation to a card as it is fed into or out of a print module. This allows the card magazine to accommodate a larger number of cards in a given space, thus enhancing the card magazine's storage capabilities. In operation, the magazine card drive receives the card from the print module or another card magazine and tilts the card as it is added to the card storage area. When a card is retrieved from the card magazine, the magazine card drive reorients the card into a proper position for presentation to the print module.
FIG. 9 is an isometric view of a rewritable card printer with the card magazine opened in accordance with an exemplary embodiment of the present invention. As illustrated, the rewritable card printer 110 includes a print module 702 and one or more card magazines 704 mechanically coupled on a base 800 . The rewritable card printer includes a front bezel 802 through which a rewritable card 114 may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer, as previously described. The card magazine is positioned on the base such that the card magazine's magazine card drive 710 may feed rewritable cards to and receive rewritable cards from the print module as previously described. The magazine card drive is removably coupled to the card storage area 712 by a hinge 900 such that the magazine may be opened to allow access to the card storage area.
A cleaning device 902 (shown through a cutaway in the front bezel 802 ) is attached to the print module such that incoming rewritable cards are cleaned before they enter the print module. The cleaning device may include flexible solid or bristled wiper elements that contact the card as it is taken into the print module. The wiper elements may be conductive so as to remove static surface charges from the card as it moves in the card printer. The wiper elements may also be charged so as to electrically attract and collect particles of dust and dirt from the card. As the print module's print card drive is reversible, the incoming card may be passed repeatedly, back and forth, through the cleaning element as needed.
In other print modules in accordance with other exemplary embodiments of the present invention, the cleaning device may be located within the print module, within the card magazine, or between the print module and a card magazine. In other rewritable card printers in accordance with exemplary embodiments of the present invention, the cleaning device is a separate device and not integrated with either a print module or a card magazine. Instead, the cleaning device is a separate motorized device similar to a card magazine and is electronically coupled to a printer controller.
FIG. 10 is a top plan view of a rewritable card printer in accordance with an exemplary embodiment of the present invention. The rewritable card printer 110 includes a print module 702 and one or more card magazines 704 a , 704 b , and 704 c that are mechanically coupled on a base 800 . The rewritable card printer includes a front bezel 802 through which a rewritable card 114 may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer, as previously described. The plan view also illustrates a possible relative position of a security feature reading device 600 , a print head 604 , and an erase head 602 within the print module. Card magazine 704 a is positioned on the base such that the card magazine's magazine card drive 710 a may feed rewritable cards to and receive rewritable cards from the print module as previously described.
In the top view, additional positions for card magazines are illustrated. These additional card magazine positions may be used to mount one or more card magazines in various relationships to the print module as may be dictated by an existing printer bay in a host game. In one possible configuration, a card magazine 704 a is located to the side of the print module. In another configuration, two card magazines, 704 b and 704 c , are mounted such that the card magazines may feed and receive rewritable cards to and from each other as companions. As illustrated, card magazine 704 b is the primary card magazine and may feed cards into and receive cards from the print module. Card magazine 704 c is a secondary card magazine that may feed cards to and receive cards from the primary card magazine.
Card magazines configured so as to allow movement of cards between the card magazines are herein termed “companion” magazines. Companion card magazines may be used to move rewritable cards around such that individual rewritable cards may be identified and retrieved from storage. This is because a card magazine with a single magazine card drive may be used as a Last In First Out (LIFO) rewritable card “memory” where the last rewritable card placed into the card magazine will be the first rewritable card retrieved from the card magazine when a rewritable card is requested. Through the use of multiple magazine drives serving a single rewritable card storage location, different styles of rewritable card memories may be implemented such as a First In First Out (FIFO) memory.
Companion card magazines may also be used to store different kinds of rewritable cards for use by the rewritable card printer. For example, the rewritable cards may have different permanent graphics imprinted on them indicating different user affiliations such as affiliations to different loyalty reward programs. In this way, a user may “upgrade” their affiliations by inserting a first style of rewritable card into the rewritable card printer and exchange it for a second style of rewritable card.
FIG. 11 a is side elevation view of a rewritable card printer in accordance with an exemplary embodiment of the present invention. The rewritable card printer 110 includes a print module 702 and one or more card magazines 704 d and 704 e mechanically coupled to a base 800 . The rewritable card printer includes a front bezel 802 through which a rewritable card may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer as previously described. Card magazine 704 d is positioned on the base such that the card magazine's magazine card drive 710 d may feed rewritable cards to and receive rewritable cards from the print module as previously described.
In the side view, an additional position for a card magazine is shown as card magazine 704 e located beneath card magazine 704 d . This position may be used to mount a card magazine as either a previously described primary or secondary card magazine. In addition, card magazine 704 e may be replaced by a larger card storage area for card magazine 704 d that extends through the base.
FIG. 11 b is side elevation view of a rewritable card charging and retrieval process in accordance with an exemplary embodiment of the present invention. The rewritable card printer 110 includes a print module 702 and a card magazine 704 mechanically coupled to a base 800 . The rewritable card printer includes a front bezel 802 (or mouth 802 ) through which a rewritable card may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer as previously described. Card magazine 704 is positioned on the base such that the card magazine's magazine card drive 710 may feed rewritable cards to and receive rewritable cards from the print module as previously described.
A technician may use an external card magazine 1112 having a mating member (or a mouth) removable and mechanically coupled to the front bezel 802 (or mouth 802 ) of the rewritable card printer to load rewritable cards into and retrieve cards, such as escrowed cards, from the rewritable card printer. This may be done without opening a cabinet in a game hosting the rewritable card printer. To load cards into the rewritable card printer, the technician couples an external controller 730 , which includes a processor and which is configured to be electronically coupled to the rewritable card printer 110 of the game machine and to the external card magazine 1112 , to the external card magazine and to the rewritable card printer. FIG. 21 illustrates an example in which the external card magazine 1112 is coupled to a gaming machine 10 via the external controller 730 . The technician then uses the external controller to send a card load signal to the rewritable card printer and the external card magazine. In response to the card load signal, the external card magazine dispenses cards into the rewritable card printer print module. In response to the card load signal, the print module accepts the dispensed cards and forwards them to an appropriate internal card magazine in the rewritable card printer.
To retrieve cards from the rewritable card printer, the technician couples the external controller and external card magazine to the rewritable card printer. In response to the card retrieval signal, the rewritable card printer retrieves cards from the rewritable card printer's one or more internal card magazines and dispenses the cards using the printer module. In response to the card retrieval signal, the external card magazine receives the dispensed cards from the rewritable card printer and stores them.
Optionally, the external print controller may store the number of rewritable cards loaded into the rewritable card printer, an identification of each of the rewritable cards loaded into the rewritable card printer, and an identifier of the rewritable card printer.
To keep track of the rewritable cards held by the rewritable card printer, the rewritable card printer may receive from the external controller a rewritable card identifier for each card dispensed by the external card magazine. The rewritable card printer may also scan each rewritable card for its identifier as each rewritable card is dispensed into the rewritable card printer.
In one rewritable card printer in accordance with an exemplary embodiment of the present invention, the rewritable card printer's printer controller contains all of the program instructions necessary to perform card loading and retrieval operations. In this embodiment, the external card magazine couples electronically with the rewritable card printer's printer controller and the rewritable card printer's printer controller commands the external card magazine to dispense and receive cards. The external controller may also communicate directly to the host game 106 or the system host 102 .
An external controller may be implemented in a variety of different external devices. For example, the external controller may be a purpose-built controller. Other external controllers may be implemented in a programmable device such a Personal Digital Assistant (PDA) or a portable or “laptop” computer.
FIG. 11 c is a side elevation view of a rewritable card printer with a card magazine having two independent magazine card drives in accordance with an exemplary embodiment of the present invention. The rewritable card printer 110 includes a print module 702 and a card magazine 1100 mechanically coupled to a base 800 . The rewritable card printer includes a front bezel 802 through which a-rewritable card may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer as previously described.
Card magazine 1100 includes a first magazine card drive 1102 and a second magazine card drive 1104 . The card is positioned on the base such that the card magazine's magazine card drives may feed rewritable cards, 114 a and 114 b , to and receive rewritable cards from the print module using the same card storage area 1106 . The first magazine card drive receives and dispenses cards from a first end 1108 of the card storage location, The second card magazine drive receives and dispenses cards from a second end 1110 of the card storage location. In this way, the card magazine may be used as a LIFO card storage device or a FIFO card storage device depending on whether two drives or one drive are employed. In addition, the magazine card drives may be used to store cards in the card storage location at an angle, such as at a 90 degree angle, relative to the orientation of the card while the card is being operated on by the printer module.
FIG. 11 d is a side elevation view of the external card magazine 1112 having a plurality of card storage locations serviced by a single card magazine drive 1118 . The external card magazine 1112 may have a plurality of card storage locations, such as card storage locations 1114 and 1116 . The single magazine card drive 1118 may service both card storage locations. In this way, a single card magazine drive 1118 may be used to shuffle cards to locate specific cards or rotate cards in storage to even out erase and write cycles performed on the cards.
FIG. 11 e is side elevation view of a rewritable card printer slidably coupled to a gaming machine in accordance with an exemplary embodiment of the present invention. The rewritable card printer 110 includes a print module 702 and a card magazine 704 mechanically coupled to a printer base 1150 .
The rewritable card printer includes a front bezel 802 through which a rewritable card may be fed by the print module's print card drive 706 , either into or out of the rewritable card printer as previously described. Card magazine 704 is positioned on the base such that the card magazine's magazine card drive 710 may feed rewritable cards 114 to and receive rewritable cards from the print module as previously described.
The printer base is further slidably coupled to a base plate 1152 that is fixedly coupled to a portion 1154 of a gaming machine hosting the printer. The rewritable card printer may be accessed while still in the gaming machine by sliding the rewritable card printer out of the gaming machine.
The card magazine may be mechanically coupled to the printer base by a quick disconnect 1156 so that the card magazine may be easily removed. To facilitate easy removal, the card magazine may be coupled to the printer controller 606 (of FIG. 7 a ) by a quick disconnect electrical connector 1157 that allows the card magazine to be installed, removed, or exchanged without removing the power to the gaming machine or rewritable card printer.
The print module may be mechanically coupled to the printer base by a quick disconnect 1158 so that the print module may be easily removed. To further facilitate easy removal, the print magazine may be coupled to the printer controller 606 (of FIG. 7 a ) by a quick disconnect electrical connector 1160 that allows the print module to be installed, removed, or exchanged without removing the power to the gaming machine or rewritable card printer.
In one embodiment of a card magazine, the card magazine is slidably coupled to the printer base separately from the print module. In this embodiment, the card magazine may accessed by sliding the card magazine past the print module so that the card magazine may be separately serviced.
FIG. 12 is a process flow diagram of a rewritable card printing process in accordance with an exemplary embodiment of the present invention. During a printing process 1200 , a rewritable card printer receives ( 1202 ) rewritable card information such as cash-out value or images to print onto the rewritable card. The rewritable card printer reads ( 1204 ) any security feature embedded in the rewritable card, storing the resultant security signature signal in temporary memory. The rewritable card printer generates ( 1206 ) indicia to print onto the rewritable card using the rewritable card values or images. Additionally, the rewritable card printer may incorporate all or a portion of security signature signal into the printed indicia as either a clearly readable value or an encoded value. The rewritable card printer then optionally erases ( 1208 ) the rewritable card and then prints the indicia onto the rewritable card prior to dispensing the rewritable card. The rewritable card printer may then transmit ( 1210 ) the security signature signal, either as an encoded value or as a clearly readable value, to a game host or cashless enabled system host.
FIG. 13 is a process flow diagram of a card escrowing process used by a rewritable card printer in accordance with an exemplary embodiment of the present invention. In a card escrowing process 1300 , a rewritable card printer determines if a card should be removed from service. A card may be removed from service for a variety of reasons. Rewritable cards have a finite number of erase and write cycles and so must be removed from service as they age. A card may become damaged so that it is no longer operable within rewritable card printer or the rewritable card's security feature is no longer readable. Cards may also have physical features such as embossing that may require the card to be handled in a special manner. As the rewritable card printer includes an optical scanner and can verify if a card was printed properly immediately after printing the card, the rewritable card printer may determine that a card was printed in error and may escrow the card. In addition, the rewritable card printer may receive an identifier for a rewritable card to be removed from service. In which case, the security feature in the rewritable card may be readable but correspond to a card to be removed from service. Another reason a card may be escrowed is that the user is exchanging one kind of rewritable card for another kind of rewritable card.
Cards may be removed from service by moving the card into an escrow location within the rewritable card printer by either a magazine card drive or by a print card drive. In the escrow process, the rewritable card determines ( 1302 ) if a card should be removed from service. If the rewritable card printer determines that the card should remain in service ( 1304 ), the rewritable card continues processing ( 1306 ) the rewritable card. Otherwise, the rewritable card printer moves ( 1306 ) the rewritable card to an escrow location 1307 within the rewritable card printer and obtains ( 1308 ) a replacement card from a card magazine 1310 and continues processing ( 1312 ) the newly obtained rewritable card.
FIG. 14 is a card retrieval process used by a rewritable card printer having companion magazines in accordance with an exemplary embodiment of the present invention. As noted previously, a card magazine having a single magazine card drive may be considered as being similar to a LIFO memory device. As previously noted, a rewritable printer controller may store information about cards stored in the card magazines. This information may include where in a card magazine a particular rewritable card is stored. In this case, a specific card stored in the card magazines may be retrieved using the following process. In a card retrieval process 1400 , a rewritable card printer receives a request for a specific rewritable card from an external host or a game controller. The rewritable card printer receives ( 1402 ) the request and determines ( 1404 ) where in the storage areas of the card magazines that the specific card is located using previously stored card information 704 . For the number of cards on top of the request card, the rewritable card moves (as indicated by loop structure 1406 , to 1410 ) all of the cards on top of the requested card into a companion card magazine's storage area 1409 . The rewritable card printer then dispenses ( 1412 ) the located card. Optionally, the rewritable card printer may replace all of the moved cards from the companion card magazine (as indicated by loop structure 1414 , 1416 , and 1418 ).
FIG. 15 is a process flow diagram of a card location process used by a rewritable card printer having multiple card magazines in accordance with an exemplary embodiment of the present invention. This card location process, 1500 , may be used when the rewritable card printer does not keep an accounting of each writeable card stored in the rewritable card printer's memory. The rewritable card printer receives ( 1502 ) an identifier for a card to be located. For each rewritable card stored by the rewritable card printer in a card magazine (as indicated by the loop structure 1504 to 1514 ), the rewritable card printer moves ( 1506 ) a rewritable card from a card magazine 1507 into a read portion of the print module 702 (of FIG. 7 ) and reads ( 1508 ) an identifier, such as a previously described security feature, from the rewritable card. The rewritable card printer then compares ( 1510 ) the read identifier to the received identifier. If the comparison indicates that the requested rewritable card is located, the rewritable card printer dispenses ( 1516 ) the located card. If the comparison indicates that the retrieved rewritable card is not the requested rewritable card, the rewritable card printer moves the card into a companion card magazine's storage location 1409 and continues processing rewritable card until either the requested card is located or the last of the stored rewritable cards is retrieved.
Optionally, the rewritable card printer may put all of the moved rewritable cards back into their original locations within a card magazine. For each of the moved cards (as indicated by the loop structure 1518 to 1522 ) the rewritable card printer retrieves ( 1520 ) a moved card out of the companion storage location and places it back into the card magazine 1507 .
FIG. 16 is a process flow diagram of a card replacement process in accordance with an exemplary embodiment of the present invention. A rewritable card printer may include two or more card magazines as previously discussed. This feature allows a gaming machine to be used for more sophisticated transactions than merely accepting wagers, playing games, and printing cash-out cards. Using multiple card magazines allows a gaming machine to also function as a customer service kiosk for several types of operations wherein a player may exchange one type of rewritable card for another during a transaction. An example of such a transaction is when a player wants to join a loyalty program.
In a card replacement process 1600 , a rewritable card printer receives ( 1602 ) a card from a user for imprinting.
The rewritable card printer moves ( 1604 ) the received card into a first card magazine 1606 for storage and possible reuse. The rewritable card printer then retrieves ( 1608 ) a replacement card from a second card magazine 1610 . The rewritable card printer continues processing ( 1612 ) the replacement card such as by printing on the card as previously described. The rewritable card printer dispenses ( 1614 ) the imprinted replacement card to the user whereby the user's original card has been replaced with another type of card.
Although this invention has been described in certain specific embodiments, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than as specifically described. Thus, the present embodiments of the invention should be considered in all respects as illustrative and not restrictive, the scope of the invention to be determined by any claims supported by this application and the claims' equivalents rather than the foregoing description.
FIG. 17 is a process flow diagram of a programming process using a rewritable card in accordance with an exemplary embodiment of the present invention. A rewritable card printer may use a rewritable card to load programming instructions into memory. The rewritable card may include programming instructions in a magnetic strip readable by the rewritable card's magnetic strip read/write head, or programming instructions may be included in the printed indicia on the card and read by an optical scanning device.
In a programming process 1700 , a rewritable card printer receives ( 1702 ) a card and determines ( 1704 ) if the card includes programming instructions. A rewritable card printer may make the determination by either scanning the card and parsing the information found on the card or may be signaled by an external device that the inserted card includes programming instructions. If the card does have programming instructions, the rewritable card printer reads ( 1706 ) the programming instructions and stores the programming instructions 113 in the rewritable card printer's memory 722 .
After reading the card, the rewritable card printer dispenses the card 724 . In addition to reading rewritable cards to obtain additional programming instructions, the rewritable card printer may receive programming instructions from an external device, such as external controller 730 (of FIG. 7 a ).
FIG. 18 is a process flow diagram of a card information storage process in accordance with an exemplary embodiment of the present invention. A rewritable card printer receives ( 1802 ) a card 1804 for storage into a card magazine. The rewritable card printer reads ( 1806 ) card information from the card. The card information may include the number of erase/write cycles that the card has gone through and the unique signature of the card. The rewritable card printer stores ( 1808 ) the card information in static memory 1810 . The static memory may be on the card itself, in a card magazine, or in a static memory location in the printer controller. Once the card information has been stored, the writable card printer erases ( 1812 ) the card and stores ( 1814 ) the erased card in a card magazine 1816 .
FIG. 19 is a process flow diagram of a card information retrieval process in accordance with an exemplary embodiment of the present invention. A card retrieval process 1900 is used by a rewritable card printer to initiate writing on to an erased card. The card's information, including information about how many read/write cycles the card has gone through, is stored in static memory 1810 as previously described. This enables a rewritable card printer to safely store rewritable cards in an erased mode and still track card usage in order to determine when a card should be removed from service.
The rewritable card printer retrieves ( 1902 ) a card from a card magazine 1816 . The rewritable card printer reads ( 1904 ) the cards signature and uses ( 1906 ) the card's signature to retrieve card information from the static memory. The rewritable card printer then continues ( 1908 ) processing the rewritable card using the retrieved card information. This may include incrementing the number of erase/write cycles that the card has gone through onto the card before dispensing the card. This processing may also include removing the card from service.
FIG. 20 is a stored card status printing process in accordance with an exemplary embodiment of the present invention. A rewritable card printer uses a stored card status printing process 2000 to report on a rewritable card the status of the rewritable card printer, game host, and rewritable cards stored by the rewritable card printer. The rewritable card printer receives 2002 a request for printing a status card. The in response to the request, the rewritable card printer retrieves ( 2004 ) a card from the card magazine 1816 . The rewritable card printer retrieves ( 2006 ) card information stored in static memory 1810 about the cards stored by the rewritable card printer. The rewritable card 20 printer then uses the card information to generate printable indicia for printing ( 2008 ) on the card and prints the indicia on the card before dispensing it.
Although this invention has been described in certain specific embodiments, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than as specifically described. Thus, the present embodiments of the invention should be considered in all respects as illustrative and not restrictive, the scope of the invention to be determined by any claims supported by this application and the claims' equivalents rather than the foregoing description.
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A machine having a card processing assembly. The card processing assembly has a card drive and a heating device. The heating device is operable to cause a human-readable symbol to be viewable on a data card.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the national stage entry under 35 USC 371 for: PCT/EP2009/061683, filed on Sep. 9, 2009, which claims the benefit of the Sep. 19, 2008 priority date of French application FR0805148. The contents of both the foregoing applications are incorporated herein by reference.
FIELD OF THE INVENTION
The invention pertains to a machine and a method for machining a part by micro-electrical discharge machining.
BACKGROUND OF THE INVENTION
Electrical discharge machining is generally also known by the acronym EDM. Its miniaturization (micro-EDM or μEDM) has different variants depending on the shape of the etching electrode (which here below will also be called here a micro-electrode). These variants are the following:
Die-sinking micro-electrical discharge machining in which a microelectrode with a shape complementary to the shape to be machined is sunken into the part. Wire micro-electrical discharge machining with a conductive wire circulating or driven by an alternating motion. The drilling of holes by micro-electrical discharge machining with a tip electrode or a tube electrode. Milling micro-electrical discharge machining better known as milling EDM.
Milling micro-electrical discharge machining does not necessarily imply a rotational motion of the microelectrode or machined part.
Here below in this description, whenever “micro-electrical discharge machining” is mentioned, reference is being made to a technology corresponding to milling micro-electrical discharge machining.
The present filing party knows machines for machining a part by micro-electrical discharge machining having a machining configuration in which a tip of an etching electrode is plunged into a bath of (insulating) dielectric fluid bathing one face to be machined of the part in order to carry out a machining of this part by micro-electrical discharge machining. This tip is small enough to enable the etching of grooves in the face whose cross-width is greater than 10 μm.
For machining complex shapes, the electrode describes a three-dimensional path in gradually removing material from the part, as would be done by a micro-mill in a chip-removal method. The difference is that the elementary action of removing material is not a mechanical action but a thermal action produced by an electrical arc. The cutting action is swift. The cooling is obtained by the dielectric fluid bath filling the space crossed by the electrical arc between the etching electrode and the part to be machined. This space is called a “gap”.
Micro-electrical discharge machining can be used to machine all conductive materials (steel, titanium etc) and semi-conductive materials (silicone, silicone carbide etc). It enables especially the machining of hard metals which cannot be machined by classic methods. Indeed, there is no mechanical contact between the electrode and the part to be machined.
Micro-electrical discharge machining can be distinguished from prior-art electrochemical corrosion methods known as electrochemical machining (ECM) by the need to create a major difference in potential between the etching electrode and the part to be machined. To create this difference in potential, the dielectric fluid has to fill the gap. Conversely, electrochemical machining is based on an oxidation reaction prompted by a current flowing between the etching electrode and the part to be machined. In order that the current may be set up, the etching electrode and the part to be machined are plunged into an electrolyte bath, i.e. a bath of a conductive fluid. The electrochemical corrosion can be produced by a current which flows between the etching electrode and the part to be machined or by discharges of current between these two elements. During the machining of a part by electrochemical corrosion, the wearing out of the electrode is often negligible. This is not the case in the electrical discharge machining method where it can happen that the wearing out of the electrode is not negligible.
In the case of milling by micro-electrical discharge machining, the electrode follows a machining path to machine the face of a part. The great value of this method is that the machining path may have several variations in height relatively to the face of the part to be machined or may even vary continuously. When this machining path has several variations in height relatively to the face of the part to be machined, it is said here that the machining is three-dimensional machining. Three-dimensional machining is done by making imprints, holes or non-through grooves the depths of which relatively to the face of the part vary in stages. This can be obtained directly from a digital definition obtained by computer-assisted design, thus preventing the manufacture of complex and costly toolings (which is the case for example with die sinking micro-electrical discharge machining). In general, high shape factors (ratio of the drilling depth to the drilling diameter) can be obtained by this method, giving typically shape factors of more than 10 or 100.
As shall be seen here below, the manufacture of electrodes limits the development of this method while potential applications are very great. Indeed, by principle, micro-electrical discharge milling makes it possible to envisage for example:
the machining of toolings:
hard-steel molds for microplasturgy master models for microstamping metal imprints by hot embossing or micro-hot-embossing.
machining of micro-parts:
micro-turbines made out of very hard materials, micro-heat-exchangers, medical parts made of titanium (for example microstents) diesel injection nozzles etc.
Specifically, in the field of micro-nanotechnologies, milling micro-electrical machining is used to machine materials little used in this field (titanium, SiC, diamond etc) with very high resolution, and at low cost. Furthermore, it is very difficult by classic techniques of microtechnology (FIB, RIE etc) to machine semi-conductive materials with a high shape factor, the main technique used in this case being designated by the acronym LIGA (Lithografie Galvanoformung Abformung or Lithography Electroplating and Molding) which is very costly. It is even impossible with these techniques to carry out machining with a continuous variation in depth (the number of photolithography masks is always limited in microtechnology). Thus, even silicon machining could derive benefit from milling micro-electrical discharge machining provided that it is easy to use electrodes with sufficiently fine tips, i.e. with diameters of less than 10 μm.
Now, in the prior art, electrodes for milling by micro-electrical discharge machining are wires, tips or tubes with a diameter of over 20-40 μm. Indeed, these microelectrodes are made finer by mechanical machining (polishing for example) by reverse electrical discharge machining or again by wire micro-electrical discharge machining with a circulating wire electrode. Specifically, in the case of the piercing of holes by micro-electrical discharge machining, demonstrations of principle have been made with 5 μm electrodes but this principle has not been extended to the machining of complex shapes. Finally, in the case of wire micro-electrical discharge machining, the diameter of the wire is limited in practice to 20 μm because of problems of mechanical strength.
The etching electrodes used for carrying out micro-electrical discharge machining are very small. These electrodes get worn out during micro-electrical discharge machining. They therefore need to be frequently replaced. This replacement of electrodes is a complicated task because of the small size and brittleness of these electrodes. For example, this replacing of electrodes is done by hand after each machining operation. These difficult operations for replacing electrodes therefore limit the productivity of current machining toolings using micro-electrical discharge machining.
The present invention generally seeks to mitigate the defects of the prior art by proposing a machining tool with a resolution of less than 10 μm and increased productivity.
SUMMARY OF THE INVENTION
An object of the invention therefore is a machine for micro-electrical discharge machining in which the machine has a mechanism for modifying the configuration of the machine to make it pass alternately and reversibly from the machining configuration to a sharpening configuration in which the tip of the same etching electrode and another electrode are plunged into a electrolyte bath to carry out a sharpening of the tip of the etching electrode by electrochemical machining.
In the above machine, the electrode is replaced less frequently because it is re-sharpened without any need to dismount it from the micro-electrical discharge machining machine. This feature therefore limits operations for replacing the etching electrode, thus increasing the productivity of this machine.
Furthermore, sharpening by electrochemical machining gives tips with diameters ranging from 10 nm to 10 μm, typically 100 nm to 1 μm. Thus, machining with a resolution of less than 10 μm is possible.
The embodiments of this machine may comprise one or more of the following characteristics:
the machine has a first recipient containing the dielectric fluid bath and a second recipient containing the electrolyte bath, and the mechanism is capable of transporting the etching electrode between the first and second recipients to pass from the machining configuration to the sharpening configuration and vice versa; the machine has a first recipient containing the dielectric fluid bath and a second recipient containing the electrolyte fluid bath and the mechanism is capable of shifting the first and second recipients relatively to the etching electrode to pass from the machining configuration to the sharpening configuration and vice versa; the machine has a same recipient containing baths of dielectric fluid and electrolyte at the same time, these baths having different mass densities and being non-miscible so that these baths can be superimposed, one above the other; the machine has an actuator capable, in the machining configuration, of shifting the etching electrode perpendicularly to the face to be machined of the part in order to adjust the width of a gap between the tip of this electrode and this face to be machined and the same actuator is capable, in the sharpening configuration, of shifting the etching electrode perpendicularly to the surface of the electrolyte bath; the machine comprises:
a controllable actuator capable, in the machining configuration, of shifting the etching electrode perpendicularly to the face to be machined of the part to adjust the width of a gap between the tip of this electrode and this face to be machined, a sensor of the shape of this tip, and a control unit capable of:
determining the wearing out of the tip from the measurements of the shape sensor, and controlling the actuator to adjust the width of the gap as a function of the determined wear.
These embodiments of the micro-electrical discharge machining tool furthermore have the following advantages:
the use of a mechanism for conveying the etching electrode between a dielectric fluid bath and an electrolyte bath makes it possible to modify the configuration of the machine in a simple way, shifting the dielectric and electrolyte fluid baths relatively to the electrode, makes it possible also to modify the configuration of the machine in a simple way, using dielectric and electrolyte fluid baths superimposed on each other in a same recipient simplifies the mechanism for passing from the machining configuration to the sharpening configuration and vice versa, using the same actuator to adjust the width of the gap during the machining and to shift the electrode relatively to the surface of the electrolyte bath decreases the cost of making this machine, adjusting the width of the gap to the wear of the electrode tip improves the precision of three-dimensional machining.
An object of the invention is also a method for machining a part by micro-electrical discharge machining by means of a configurable machine for micro-electrical discharge machining. This method includes the actuation of a mechanism for modifying the configuration of a machine to pass alternately and reversibly between:
a machining configuration in which a tip of an etching electrode is plunged into a bath of dielectric fluid that bathes a face to be machined in order to perform a machining of this part by electrical discharge machining, this tip being small enough to enable the etching of grooves in the face whose cross-width is less than 10 μm, and a sharpening configuration in which the tip of the same etching electrode and another electrode are plunged into an electrolyte bath to carry out a sharpening of the tip of the etching electrode by electrochemical machining.
The embodiments of this method may include one or more of the following characteristics:
the method comprises:
measuring the shape of the tip, determining the wear of the tip from these measurements, and activating the automatic passage from the machining configuration to the sharpening configuration as soon as the determined wear crosses a predetermined threshold;
before passing to the machining configuration, the method comprises:
measuring the shape of the tip comparing the measured shape with a predetermined template, and permitting the passage to the machining configuration if the shape is included in the predetermined template and, if not, inhibiting the passage to the machining configuration;
the method comprises:
measuring the shape of the tip, determining the wear of the tip from measurements of its shape, and adjusting the width of a gap between the tip and the face to be machined as a function of the determined wear.
The embodiments of this micro-electrical discharge machining method furthermore have the following advantages:
verifying the wear of the electrode at least once during the machining process and, advantageously, doing this verification several times prevents the use of a defective electrode for machining a part. activating the sharpening of the tip of the electrode as a function of the determined wear of this tip enables the re-sharpening of this tip only when necessary, permitting the passage to the machining configuration only if the shape of the tip is within a predetermined template prevents the machining of a part with a defective electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be understood more clearly from the following description, given purely by way of a non-exhaustive example and made with reference to the appended drawings, of which:
FIG. 1 is a schematic illustration in perspective of a machine for micro-electrical discharge machining,
FIG. 2 is a flowchart of a method of micro-electrical discharge machining by means of the machine of FIG. 1 ,
FIGS. 3 to 8 are schematic illustrations of the different stages in the sharpening of an etching electrode of the machine of FIG. 1 ,
FIG. 9 is a schematic illustration of a three-dimensional machining carried out by means of the machine of FIG. 1 ,
FIG. 10 is a schematic and partial illustration of another embodiment of a machine for micro-electrical discharge machining.
DETAILED DESCRIPTION
In these figures, the same references are used to designate the same elements.
Here below in this description, the characteristics and functions well known to those skilled in the art are not described in detail.
FIG. 1 shows a machine 2 for the micro-electrical discharge machining of a part 4 . This machine 2 is configurable. It can pass from a machining configuration to a sharpening configuration and vice versa. In the machining configuration, the machine can be used to machine the part 4 . In the sharpening configuration, the machine 2 can be used to sharpen an etching electrode. In this embodiment, to pass from the machining configuration to the sharpening configuration, an etching electrode can be transported from a machining station to a sharpening station. In FIG. 1 , the machine is shown in its machining configuration.
Here, the part 4 is a parallelepiped substrate made out of a semi-conductive or conductive material. For example, the semi-conductive material may be silicon or indium phosphide (InP) or the like. The conductive material may be steel, silicon carbide, titanium or the like.
The part 4 has a horizontal upper face 5 to be machined.
The part 4 is attached without any degree of freedom to a mobile substrate-holder 10 . For example, the part 4 is wedged between stops 6 and 8 which hold it on the substrate-holder 10 .
The substrate-holder 10 can be shifted horizontally relatively to a horizontal 20 worktop 12 . To this end, the machine 2 has translational motion motors, for example piezoelectric actuators 14 and 16 capable of shifting the substrate-holder 10 respectively in two directions X and Y, which are horizontal and perpendicular directions. These actuators 14 and 16 are controllable. Here, the piezoelectrical actuators 14 and 16 have a resolution of less than or equal to 3 nm. They have a position sensor to control the absolute position of the substrate-holder 10 to within 6 nm.
To simplify the description, our main example will be that of piezoelectric actuators based on piezoelectric ceramic stacks with or without mechanical amplification. These piezoelectric actuators are described for example in the technical documentation of the manufacturer Physik Instruments (http://www.physikinstrumente.com/).
The part 4 is plunged into a bath 19 ( FIG. 9 ) of dielectric fluid contained in a recipient 18 . The vertical walls of the recipient 18 surround the part 4 so that the face 5 is bathed in the bath 19 . In FIG. 1 , for the part 4 to be visible, only the vertical walls of the recipient 18 situated behind the part 4 have been shown.
The dielectric fluid contained in the recipient 18 is an insulating fluid, i.e. its resistivity must be great. “Great resistivity” designates resistivity of over 0.1 MΩ.cm and preferably greater than 1 MΩ.cm. For example, the dielectric fluid here is deionized water with a resistivity of over 1 MΩ.cm as described in the following article:
Do Kwan Chung, Bo Hyun Kim and Chong Nam Chu, “Micro-electrical Discharge Milling using Deionized Water as a Dielectric Fluid”, Journal of Micromechanics and Microengineering , vol 17 (2007) 867-874.
Preferably, the electrical resistivity of the dielectric fluid will be as great as possible. Indeed, the greater the electrical resistivity, the smaller the gap between an etching electrode and the face 5 and the more precise the machining.
The machine 2 has an etching electrode 20 . This electrode 20 has a tip 22 on its free-end side.
When the machine 2 is in its machining configuration as shown in FIG. 1 , the end of the tip 22 is separated from the upper face of the part 4 by a gap with a width L. This gap should be wide enough to electrically insulate the tip 22 of the face 5 . This gap should also be small enough so that when a different of potential is applied between the electrode 20 and the part 4 , an electrical arc can arise in this gap. The electrode 20 is used here to carry out three-dimensional machining by electrical discharge machining in the face 5 . To this end, the electrode 20 follows a machining path represented on the face 5 by a line of dashes 24 .
FIG. 1 also shows a groove 26 already etched in the face 5 by means of the electrode 20 . This groove may have continuous or discontinuous variations in height. FIG. 9 shows continuous variations in height. The path may also have discontinuous variations, for example a vertical hole, possibly opening out on the other side of the part, which could be added after the machining of the groove 26 .
The tip 22 has a high shape factor, i.e. a factor of more than 10. The term “shape factor” herein designates the ratio between the length of the tip 22 and its width in the vicinity of its free end. The length is measured starting from the distal end 25 of the tip 22 in going towards the opposite end. This length is measured by allowing a variation of 10% in the diameter of the tip. In general, this shape factor ranges from 10 to 100. A high shape factor of the tip also enables the part 4 to be etched with patterns having a high shape factor. The entire length included within the criterion of variation of 10% could be used for the machining.
Here, the electrode 20 is designed to be capable of etching grooves in the part 4 , the cross-thickness of which ranges from 10 nm and 10 μm, typically between 100 nm and 1 μm. The width of the smallest groove to be etched determines the diameter of the tip 22 . Indeed, this diameter must be smaller than the cross-width of the smallest groove to be etched.
Here, the part of the electrode 20 opposite the tip is generally cylindrical. For example, the diameter of this part ranges between 100 and 500 μm, typically 250 μm so that the entire tip has sufficient mechanical worthiness. It is quite clear that the diameter of the electrode diminishes when moving from this part towards the sharpened part, with a transition zone that will be used neither for the sharpening nor for the machining. For example, the total length of the electrode 20 is 1 cm.
Ideally, the end of the tip 22 has only a few atoms of thickness. To this end, the method described in FIGS. 3 to 8 is used. For greater information on this sharpening method, reference may be made to the following document which belongs to a remote technical field, i.e. that of atomic force microscopes or scanning tunnel microscopes:
J. P. Ibe, J. P. P. Bey, S. L. Brandow, R. A. Brizzolara, N. A. Burnham, D. P., DiLella, K. P. Lee, C. R. K. Marrian, and R. J. Colton, “On the electrochemical etching of tips for scanning tunneling microscopy,” Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films , vol. 8, pp. 3570-3575, 1990.
The electrode 20 is for example made out of platinum-iridium (Ptlr) or tungsten (W).
Each time that an electrical arc occurs between the tip 22 and the face 5 , small particles of material are liberated from the part 4 . During the machining process, particles of matter can remain in the gap. Now, these particles are made out of the same material as the part 4 , i.e. a semi-conductive or conductive material. They can therefore locally modify the conductivity of the dielectric fluid between the tip 22 and the face 5 .
To reduce this phenomenon, it is necessary to renew the dielectric fluid. To this end, the machine 2 has an apparatus 30 for ejecting dielectric fluid in the vicinity of the gap. This ejection device is used to discharge the semi-conductive or conductive particles present in this gap. This ejection device 30 therefore enables the restoration, at least in part, of the low conductivity of the dielectric fluid present in this gap. For example, to put it very broadly, the ejection device 30 may be formed by a controllable pump 32 and a tube 34 capable of ejecting the dielectric fluid pumped by the pump 32 towards the gap.
The end of the electrode 20 opposite the tip 22 is kept vertical and without any degree of freedom in a mandrel 36 . The mandrel 36 is fixedly joined to a plate 38 . The plate 38 can be shifted solely in a direction Z vertical and perpendicular to the X and Y axes. To this end, for example, one end of the plate 38 is mounted so as to be sliding in a vertical slideway 40 made in a vertical structural section 42 .
A controllable actuator 44 , fixedly joined to the structural section 42 , is used to shift the plate 38 from top to bottom. For example, the actuator 44 is a piezoelectric actuator whose resolution is smaller than or equal to 3 nm.
Actuators 39 are also used to adjust the tilt and orientation of the electrode 20 by rotation θ x , θ y , θ z respectively about axes X, Y and Z of the XYZ referential system. For example, these actuators are housed between the plate 38 and the mandrel 36 .
To make the machine 2 go from its machining configuration to its sharpening configuration, it has a mechanism for conveying the electrode 20 from the machining station to the sharpening station without its being necessary to dismount this electrode. Furthermore, here, this mechanism also enables the electrode to be carried into a metrology unit.
It is the machining station that has been described up to now. The sharpening and metrology units are described here below.
The mechanism used to modify the configuration of the machine 2 includes a base 45 mounted rotationally about a vertical axis 46 and fixedly joined to the worktop 12 . The structural section 42 is fixed without any degree of freedom to the base 45 . Furthermore, the rotation of the base 45 about the axis 46 is herein commanded by a controllable actuator 48 .
Thus, when the base 45 pivots about the axis 46 , the electrode 20 describes a horizontal arc of a circle 50 . The arc of the circle 50 is schematically shown in the worktop 12 .
Here, when the electrode 20 shifts along the arc 50 in going from right to left, the electrode 20 first of all encounters the metrology station and then the sharpening station.
The metrology station has been shown between the machining station and the sharpening station only to simplify the illustration of FIG. 1 . Advantageously, this metrology station is situated above the machining station so that the passage from the machining station to the metrology station and vice versa is done solely by means of the actuator 44 .
The metrology station includes sensors of position, orientation and shape of the tip 22 . The term “shape sensor” herein designates a sensor capable of measuring at least one physical quantity representing a geometrical characteristic of the tip used to determine the wear on this tip. Advantageously, the shape sensor could also measure the diameter of the tip 22 , its shape factor and the height of the transition zone. The orientation sensor is used to determine the tilt of the electrode relatively to 25 the axes of the XYZ referential system of the part to be machined and relatively to the free surface of the electrolyte. The position sensor is used to localize the position of the most distal end of the tip 22 in the XYZ referential system.
Here, these three sensors are made with a single camera 54 with very high resolution. The term “very high resolution” herein designates a camera for which the 30 pixels have a size of less than 0.5 μm and preferably less than 0.3 μm. This camera 54 has an objective 56 positioned in the vicinity of the arc 50 so that it can film the tip 22 when the electrode 20 is inside the metrology station. The position of this camera in a XYZ referential system fixedly joined to the worktop 12 is fixed and known. Thus, the coordinates of each pixel of an image filmed by the camera 54 can be expressed in the XYZ referential system. The working of this camera 54 is described in greater detail with reference to FIG. 2 .
The sharpening station enables an electrode with a diameter of 10 nm to 10 μm, typically 100 nm to 1 μm, to be prepared speedily, i.e. in less than 30 minutes, and automatically and at low cost.
To this end, the sharpening station comprises:
a recipient 60 containing an electrolyte bath 62 , and an electrode 64 bathing in the bath 62 .
For example, this bath 62 is a saltwater (NaCl) bath.
The machine 2 also has a power source 66 that is entirely controllable and common to the machining and sharpening stations. For example, this power supply source 66 is capable of behaving:
in the sharpening configuration, as a DC or non-DC current generator in an adjustable voltage range to effect the circulation of an electrical current between the electrodes 20 and 64 when these electrodes are dipped in the bath 62 , and in the machining configuration, as a DC or non-DC voltage generator in an adjustable range of current, to produce a difference in potentials that is sufficient to activate the appearance of an electrical arc between the tip 22 and the face 5 when the electrode 20 is dipped in the bath 19 .
To this end, the electrodes 20 and 64 and the part 4 are electrically connected to this power supply source 66 . To simplify FIG. 1 , the electrical connection between the electrode 20 and the power supply source 66 has been omitted.
The power supply source 66 is also capable of measuring the difference in potential and the intensity of the current between the electrode 20 and the part 4 and, alternately, between the electrodes 20 and 64 .
Finally, the machine 2 has a control unit 70 to command the actuators 14 , 16 , 19 , 39 , 44 and 48 . This unit 70 is also capable of commanding the source 66 and acquiring the information measured by the camera 54 . To simplify FIG. 1 , the connections between the units 70 and the different controlled elements have not all been shown.
The unit 70 is made by means of a programmable electronic computer capable of executing instructions recorded on an information-recording medium. For example, to this end, the unit 70 is connected to a memory 72 containing the different instructions needed for executing the method of FIG. 2 . Furthermore, here the memory 72 contains a file storing the predetermined path of the electrode 20 to obtain the desired three-dimensional machining of the part 4 .
For example, the electronic computer is herein a computer equipped with a central processing unit 74 and a man/machine interface formed by a screen 76 and a keyboard 78 .
The working of the machine shall now be described with reference to the method represented in FIG. 2 .
We take D to be the initial length of the electrode with an initial diameter φ. For example D=1 cm and φ=250 μm. Initially, the machine 2 is brought to its sharpening configuration. For example, in a step 90 , the unit 70 commands the actuators 44 and 48 to convey the electrode 20 up to the sharpening station. Then, these actuators are commanded to make the free end of the electrode 20 dip into the bath 62 so that a first segment with a height δ of the electrode is in contact with the electrolyte. The segment with a height δ corresponds to the part of the electrode which will cover the future tip, the transition zone of the electrode leading to the diameter δ and a margin of safety. For example, for a future tip diameter of 1 μm, the height δ is of the order of 50 to 100 μm. When the free end of the electrode 20 is dipped in the bath 62 , the machine 2 is considered to be in its sharpening configuration.
Once the machine 2 is in the sharpening configuration, it performs a step 92 for sharpening the electrode 20 . Here below, we shall describe the sharpening method known as the “drop off” method as reported especially in:
A. J. Melmed, “The art and science and other aspects of making sharp tips,” J. Vac. Sci. Technol. B, vol. 9, pp. 601-608, 1991.
Thus, for example, during an operation 94 , the unit 70 commands the power supply source 66 to apply a current between the electrode 64 and the electrode 20 . Thus, a thinning down of the electrode 20 occurs preferably at the level of a meniscus 96 (see FIGS. 3 to 8 ) formed by the bath 62 around the electrode 20 .
Various successive stages of thinning down the segment with a height δ during the operation 94 are shown in FIGS. 3 to 8 . The electrochemical machining due to the circulation of current between the electrodes 20 and 64 sharpens the electrode 20 more swiftly at the meniscus 96 than elsewhere. Thus, the electrochemical machining gradually eats into the electrode 20 at this meniscus 96 until the most distal end of the segment with a height δ gets detached from its main part ( FIG. 8 ). After this detachment, the lower end of the electrode 20 is shaped to form a tip. This tip is very thin and may have a width of only a few atoms at its distal end. The tip 22 is thus made.
If necessary, along with the operation 94 , during an operation 98 , the actuator 44 is commanded so as to gradually shift the electrode 20 upwards. This operation 98 gives a more elongated tip 22 . Further details on the way to command the actuator 94 to elongate the tip 22 are for example given in the following article:
S. H. Choi S. H. Ryu D. K. Choi C. N. Chu, <<Fabrication of WC micro-shaft by using electromechanical etching>>, Int. J. Adv. Manuf. Technol (2007), pages 682-687.
Once the sharpening step 92 has been completed, at a step 100 , the actuators 44 and 48 are commanded to move the tip 22 up to the metrology station.
When the tip 22 is at the metrology station, in a step 102 , the shape, position and tilt of this tip 22 are measured. For example, during an operation 104 , the actuators 44 and 48 are commanded to place the tip 22 so as to be exactly facing the objective 56 . Then during the operation 104 , the camera films the tip 22 , in making the tip move if necessary, and transmits the filmed images to the unit 70 . Each image is a measurement of the shape, position and orientation of the tip 22 .
Then, during an operation 106 , the unit 70 optionally corrects the spatial orientation of the electrode in commanding the actuators 39 .
During an operation 107 , it determines the spatial relationship linking the position of the most distal end of the tip 22 to the position of the mandrel 36 . For example, should the electrode 20 be perfectly vertical, this spatial relationship can be reduced to a length l 0 between the reference point on the mandrel 20 and the most distal end of the tip 22 . During the operation 107 , this length is very precisely measured. During the operation 107 , the received images are also processed to determine the contour of the tip 22 . The position of the reference point on the mandrel in the XYZ referential system is also taken. The position of the reference point is obtained for example from the state of the actuators 44 and 48 .
Then, during an operation 110 , the unit 70 compares the determined contour of the tip 22 with one or more predetermined templates. If the determined contour is outside the predetermined templates, then the method returns to the step 90 . For, this means that a defect in sharpening the electrode 20 has occurred during the step 92 so much so that this electrode is incapable of accurately machining the part 4 . In this case, the electrode is plunged for example into an additional segment of height δ in the electrolyte. Thus, D/δ operations of re-sharpening operations can be performed without the machine operator having to manipulate the electrode.
If the contour of the electrode corresponds to the template, then the method is continued with a step 112 for commanding the actuators 44 and 48 to make the machine 2 go into a machining configuration. In the machining configuration, the tip 22 gets dipped in the bath 19 of dielectric fluid of the machining station.
Once the machine is in this machining configuration, a machining step 114 starts.
For example, during an operation 116 , the actuators 14 , 16 , 44 and 48 are commanded to position the tip 22 above the starting point of the machining path of the part 4 .
Then, during an operation 118 , a potential difference is applied between the electrode 20 and the piece 44 . Preferably, the electrode 20 is grounded and a positive potential is applied to the part 4 . This potential difference can be obtained directly with a generator driven by transistors (with a finite output resistance, advantageously adjusted so as to limit and control the intensity). It can also be done indirectly by means of a capacitor in a device known as a relaxation generator. Combined devices are also possible. Typically the difference in working potential is experimentally adjusted between 0.1 and 200 V, especially as a function of the nature of the electrode, the diameter of the tip, its exact shape (radius of curvature), the value of the gap, nature of the dielectric, its conductivity if it varies during the machining and the nature of the part to be machined (physical nature, thermal conductivity, calorific capacity, electrical conductivity etc). For example, a difference in potential of 10 V makes it possible to machine silicon with a tungsten tip having a diameter of 1 μm (the dielectric is de-ionized water). To machine stainless steel with the same tip, it is advantageous to apply a voltage of 30 to 100 V.
Once the electrode 20 has been biased relatively to the part 4 , in an operation 120 , the actuator 44 is commanded to gradually bring the tip 22 closer to the face 5 . As and when the tip 22 approaches the face 5 , electrical arcs occur. The electrical characteristics of these electrical arcs are monitored to detect the first efficacious electrical arc to machine the face 5 of the part 4 .
An electrical arc is deemed to be efficacious when it enables the etching of the part in the vicinity of the gap. There are various means of speedily determining whether an electrical arc is efficacious (advantageously during operation so as not to interrupt the method and so as to be able to stabilize the machining). For example, when measuring the gap current, in the case of an electrical power supply driven by transistors or again when tracking the progress of the potential difference during the descent of the electrode in the case of a power supply based on the charge of a capacitor. In the latter case, any sudden variation in the potential difference often corresponds to a forceful transfer of energy leading to erosion. Other quantities can be used to qualify the electrical arcs (radio-electrical frequencies generated during the arc, light energy etc).
To put it explicitly, situations other than non-erosive discharges may correspond to a mechanical contact leading to a short circuit (which must imperatively be detected to prevent deterioration of the electrode tip), to an open circuit corresponding to an electrode that is far too distant from the part or again to an electrical leak in the gap that prevents the machining.
Be that as it may, when the first efficacious electrical arc is detected, the height z 1 of the most distal end of the tip 22 is recorded by the computer during an operation 122 , for example by noting the position of the electrode by means of a position sensor integrated into the actuator 44 . The height z 1 then serves as the point of origin for the vertical shifts of the electrode 20 .
Then, in an operation 124 , the machining proper of the part 4 starts. It is then necessary to:
continue to push in the electrode vertically, especially to compensate for the increase in the gap due to the erosion of the part and possibly the erosion of the electrode, shift the electrode laterally and/or vertically to machine the part in doing this while at the same time applying an ad hoc difference in potential.
For example, while applying a potential difference, the part 4 is shifted in the directions X or Y during an operation 124 so that the tip 22 follows the predetermined machining path. Simultaneously, during an operation 126 , the electrode 20 is shifted in the direction Z to machine the part to the desired depth. The machining depth is herein determined relatively to the position z 1 taken during the operation 122 .
To obtain accurate machining, it is necessary to adapt the rate of creation of discharges, the rate of renewal of the dielectric, the shifting speeds and the speed of penetration of the electrode and therefore especially the variation of the gap. To this end, the invention plays on the cycle for controlling the potential difference, especially the duration during which the potential difference is applied and the duration during which the system is at rest. This duration is often used to restore the dielectric conditions during an operation 128 . In this operation, the original dielectric properties of the dielectric fluid present in the gap are restored. Indeed, these dielectric properties deteriorate as and when the machining takes place given that, after each electrical arc, conductive or semi-conductive particles are released in the gap and therefore modify the electrical conductivity between the electrode 20 and the part 4 . Advantageously, to restore the original dielectric conditions, the electrode 20 is made to vibrate from top to bottom with an amplitude of some tens to some hundreds of nanometers. At the same time, advantageously, the part 4 is also made to vibrate. These vibrations of the part 4 are obtained by shifting it in a horizontal plane. Finally and also in parallel, a stream of dielectric fluid is ejected into the gap by means of the tube 34 to clean the conductive and semi-conductive particles that may be present in this gap.
Regularly, a step 136 is carried out to command the actuators 44 and 48 to bring the electrode 20 to the metrology station. Then, in a step 140 , the wear of the tip 22 is determined. For example, in an operation 142 , the shape of the tip 22 is again measured by means of the camera 54 . The images obtained are transmitted to the unit 70 .
During an operation 144 , the unit 70 then determines the new spatial relationship which links the position of the most distal end of the tip 22 and the position of the mandrel 36 . For example, the operation 144 is identical to the operation 104 . The length measured at the end of the operation 144 is denoted as I′ 0 .
Then, during an operation 148 , the wearing out of the tip is given by the following difference Δ:
Δ= l 0 −l′ 0
Then, in a step 150 , the unit 70 makes a check to find out whether or not the determined wear calls for a re-sharpening of the electrode 20 . For example, at the step 150 , the difference A representing the wear of the tip 22 is compared with a predetermined threshold S 1 . If this threshold S 1 is crossed, then the unit 70 automatically activates the modification of the configuration of the machine 2 and the passage to the sharpening configuration. This corresponds to a return to the step 90 .
If not, the method returns to the step 114 to machine a new part or a new portion of the face 5 of the part 4 . However, before returning to the step 114 , in a step 152 , the origin of the heights z 1 is modified as a function of the difference Δ. For example, a new starting point of the height z′ 1 defined by the following relationship is taken into account for the vertical displacements of the electrode 20 :
z′ 1 =z 1 −Δ
Thus, the width L of the gap is adjusted as a function of the difference A during 10 the next operation for machining the part 4 . This makes it possible to carry out the operation 124 directly without passing through the operations 116 to 122 .
It will be noted here that, when the method returns to the step 90 , the tip 22 is dipped in the bath 62 on a new height δ just above the former height. Thus, during the re-sharpening operation, the electrochemical etching finally separates the tip 22 from the main part of the electrode 20 revealing an entirely new tip which will be used for the next machining operation.
The machining step 114 stops after the entire path has been travelled.
FIG. 9 shows an example of three-dimensional machining performed by means of the machine 2 . In this example, the vertical section of the shape to be machined has two stages, respectively at depths h 1 and h 2 . The depths h 1 and h 2 are measured in the direction Z relatively to the face 5 . To machine the stage at a depth h 1 , the unit 70 commands the actuator 44 to stop the machining when the tip 22 is situated at the height z 1 −h 1 . Similarly, the step at the depth h 2 is obtained by stopping the etching of the face 5 when the electrode 20 is at the height z 1 -h 2 . The height z′ 1 is used instead of z 1 during subsequent machining operations and so long as the wearing out of the tip does not go beyond the threshold S 1 .
FIG. 10 shows the machine 170 for micro-electrical discharge machining. To simplify FIG. 10 , only one portion of the machining and sharpening stations has been shown.
The machine 170 is identical to the machine 2 except that to pass from the machining configuration to the sharpening configuration and vice versa, only one vertical displacement in the direction Z is necessary. To this end, the recipient 18 is replaced by a recipient 171 containing a bath 172 of dielectric fluid as well as an electrolyte bath 174 . The mass density of the bath 172 is different from the mass density of the bath 174 . Furthermore, the baths 172 and 174 used are non-miscible. For example, in FIG. 10 , the density of the bath 172 is greater than the density of the bath 174 . In these conditions, the bath 174 is situated above and directly in contact with the bath 172 . The part 4 and especially the face 5 of this part 4 bathe in the bath 172 .
The mode of operation of the machine 170 is similar to that of the machine 2 . More specifically, during the machining of the face 5 with the electrode 20 , the tip 22 gets dipped in the bath 172 . When the tip 22 needs to be re-sharpened, the mandrel 36 is shifted vertically upwards to bring the tip 22 into the bath 174 . The re-sharpening by electrochemical corrosion of the electrode 20 can then take place.
In the machine 170 , it is not necessary for the structure 42 to be mounted rotationally on the worktop. The actuator 48 can be omitted. Similarly, the recipient 60 is eliminated.
Many other embodiments are possible. For example, the dielectric fluid may be a gas and not a liquid. The dielectric fluid may also be pure water or water mixed with alcohol. The dielectric fluid may also be any other dielectric used in electrical discharge machining, especially a hydrocarbon.
In the embodiment of FIG. 10 , the density of the dielectric fluid can be smaller than that of the electrolyte so that the electrolyte bath is situated beneath the dielectric fluid bath.
The measurement of the shape, position and orientation of the tip 22 can be done by apparatuses independent of one another. These apparatuses may furthermore be partially or totally integrated either into the machining station or into the sharpening station. The measurements can therefore be done without using cameras and metrology stations and the metrology station can be omitted. For example, the shape and position can be measured by mechanical or electrical contact between the tip 22 and a reference face. Advantageously, the position and shape of the tip 22 can also be measured by bringing the tip 22 very gradually closer to a conductive reference face until a tunnel effect occurs. When the tunnel effect occurs, although the tip 22 does not touch the conductive face, a current flows between these two elements. The electrical characteristics and especially the intensity of this current enable the position of the tip relative to the conductive face to be estimated without there being any contact between these two elements. Preferably, in these latter embodiments, the power supply source 66 delivers a very weak, non-erosive and/or non-sharpening electrical signal, enabling the detection of a mechanical contact by electrical detection (or an approach by tunnel effect) between the electrode and the part to be machined and/or the surface of the electrolyte.
An additional camera with a line of sight parallel to the axis Z can also be used to film the tip 22 from beneath. Thus, a longitudinal translational motion of the electrode is expressed by a horizontal shift of the tip if the electrode 20 is tilted. The amplitude of this horizontal shift is proportional to the tilt of the electrode 20 .
Other methods for the contactless measuring of the shape of the tip 22 can be implemented such as for example the method described in the following article:
H. S. Lim, S. M. Son, Y. S. Wong, M. Rahman, <<Development and Evaluation of an on-machine optical measurement device>>, International Journal of Machine Tools and Manufacture 47 (2007), pages 1 556-1 562.
Other sharpening methods are possible, all based on electrochemical etching (the use of a non-DC power supply source with different levels of electrical signals, ramps, pulses with different cycle ratios etc).
During a new sharpening of the tip 22 , it is also possible to dip only the most distal end of the tip so that it is re-sharpened.
The machines described here are not limited to three-dimensional machining. The machines may also be specifically adapted to the performance of simpler machining operations such as making via holes through a plate. In this case, the machine can be simplified. Indeed, determining the wear of the tip is no longer necessary and can be omitted.
There are many other possible embodiments of the mechanism for modifying the configuration of the machining machine. For example, it is possible to shift the baths of dielectric fluid and electrolyte relatively to a fixed electrode in the XYZ reference system. For example, in this embodiment, the recipients 18 and 60 are mounted on a tray rotating about the axis 46 and the structural section 42 is fixed without any degree of freedom in rotation about the working worktop 12 . Thus, in this embodiment, it is no longer the electrode 20 that moves but the different stations namely the machining station, the metrology station and the sharpening station. The relative motion of the electrode with respect to the machining and sharpening stations can be linear and not circular.
In another variant, the machine has only one recipient capable of alternately receiving the baths of dielectric fluid and electrolyte fluid. To this end, this recipient is provided with a controllable valve enabling firstly the draining out of the fluid currently present in the recipient and secondly the refilling of the recipient by means of another bath. Thus, in this embodiment, in the machining configuration, the recipient contains a bath of dielectric fluid. In the sharpening configuration, the same recipient contains an electrolyte bath.
Again, in another embodiment, the mechanism enabling the passage from the machining configuration to the sharpening configuration and vice versa consists in ejecting a dielectric gas towards the gap in a sufficiently forceful manner to flush out the electrolyte bath under the effect of the pressure of this gas. When this gas stream is interrupted, the electrolyte bath re-occupies the gap so that a sharpening by electrochemical etching can take place.
Instead of the stacked piezoelectric actuators, other piezoelectric actuators can be envisaged, for example those based on a stick slip type operation. Indeed, these devices whose actuation principle is based on the jerky motion observed during the relative sliding of two objects are a compromise between cost, shifting precision and travel. When the machining resolution sought does not reach 10 nm, especially when the resolution ranges from 100 nm to 1 μm, other variants are possible. For example it is possible, on a same translational axis, to have a piezoelectric actuator and an electrical motor so as to combine the movements with the advantages of obtaining substantial values of travel (typically 10 to 100 nm) with high resolution. It is advantageous to plan for a sensor of movement such as a capacitive sensor or a strain gauge in the case of a purely piezoelectric axis or an optical rule in general.
The renewal of the dielectric fluid between the tip 22 and the face 5 can be obtained by other methods. For example, the following methods can be used alone or in combination:
making the etching electrode rotate, for example by means of a rotating mandrel, making the etching electrode vibrate, for example by means of a piezoelectric actuator, total renewal of the fluid in the recipient 18 .
By way of an illustration, these methods are described in the following document:
L. Bianchi and E. Rigal, “Usinage par électro-érosion,” (Electrical Discharge Machining) in Techniques de l'Ingénieur, vol. B7310. Paris, 1987, pp. 24.
The use of the determined wear to adjust the width of the gap between the tip 22 and the face 5 can be implemented independently of the mechanism for passing from the machining configuration to the sharpening configuration. In particular, such a method of adjusting the width of the gap can be implemented in machines for electrical discharge machining without such a mechanism for modifying the configuration of the machine.
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The invention relates to a machine for machining a part by micro-electrical discharge machining, said machine comprising a mechanism ( 44, 45, 46, 48 ) for modifying the configuration of the machine so as to alternatively and reversibly switch from a machining configuration to a sharpening configuration in which the tip of a same etching electrode ( 20 ) and another electrode ( 64 ) are dipped in an electrolyte bath in order to sharpen the tip of the etching electrode by electrochemnical corrosion.
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FIELD OF THE INVENTION
The present invention relates generally to information acquisition and product reviews, and more specifically, to a computer-based method for providing customized text content ratings and/or recommendations.
BACKGROUND OF THE INVENTION
Many methods and systems for providing information, ratings and/or recommendations on text or written materials, such as books, involve computer-based environments and access to databases storing information on such written materials. In many such networked computer environments, the requirements for providing useful information, ratings or recommendations can vary greatly in response to input from or information regarding the subject user (or “customer” hereinafter). For example, in situations where a customer desires book information or recommendations via the World Wide Web (i.e., a book shopping search, such as on Amazon.com®), knowledge of parameters such as what types of books the customer enjoys as well as which books the customer has already read are required to provide the most useful results. Not only do these parameters vary greatly from customer to customer, but they can also include information as to how the tastes of one customer correspond to those of another. One method of generating such personalized recommendation is known as collaborative filtering.
Collaborative filtering methods in this field operate at the most basic level by asking each customer to rate books or other written matter that the customer is familiar with. These ratings are then analyzed and used to correlate and divulge various specific characteristics or commonalities from the totality of ratings data. A profile may be derived for each customer, and comparison of one customer's profile with similar profiles can be done to identify items of potential interest.
Regardless of the specific parameters or filtering method involved, however, the information, ratings and/or recommendations must be useful to the customer and helpful for the task at hand to ensure continued popularity and success of that network environment. For example, current methods of providing book ratings or recommendations are frequently unsatisfactory due to the lack of information provided, lack of more appropriate information, and/or the inefficient or otherwise problematic functionality of acquiring information. Particularly with regard to the provision of book-related systems over networked computer environments, a customer is frequently given ratings or recommendations that are only based on information on what other people thought about the written material in general. However, for ratings or recommendations that require more useful and/or individual-specific response, current methods of book or text content related assistance and interaction have significant drawbacks.
One problem with current methods of providing such text content-related assistance over a network is that the procedures undertaken to determine the ratings or recommendations do not take into account information relating to the current customer's profile, likes and/or dislikes. For text content-related assistance that involves some analysis of the current customer's preferences to provide useful information for more helpful ratings and recommendations, this presents a burden in the provision of effective assistance.
A drawback with some current collaborative methods of providing text content-related assistance over a network is that the procedures undertaken to acquire and populate a database with current customer preference data frequently present a complex, large or frustrating burden to customers, particularly new users, of the system. For systems that otherwise derive advantage from ease-of-use and/or other such characteristics of attractiveness to a customer, this again presents a burden in acquiring appropriate results and presenting helpful information.
Another drawback is that current methods of such ratings or recommendations typically use static or overly simplistic algorithms for determining potential books for a customer. This approach often leads to non-dynamic results and misses the objective of obtaining information that is as useful as possible.
Therefore, current systems and methods of rating or recommendation are generally unable to provide the usefulness, flexibility, and customer-specific objectives required to efficiently and effectively provide the satisfactory results necessary for meaningful identification, rating or recommendation of text content, such as books.
SUMMARY OF THE INVENTION
A system and computer-based method for providing, in a network environment, customized text content ratings and/or recommendations based on certain information, such as information concerning the text content that a customer has read. The system includes a first (or book) database, a customer database, a database server for searching, retrieving and comparing data from the databases, a web server to connect the database server to the network, and a customer connected to the database server over a network. In one embodiment, the customer performs a book registration function followed by a book rating function. In the registration function, information regarding the books and other periodicals that have been read by the customer is acquired, compiled by the database server, and stored in the customer database. One book registration method done prior to any rating function includes the generation of a search result list (based on criteria entered by the customer), from which the customer can then select one or more books to register. In the book rating function, a customer establishes a book that he is considering, and the web server requests the database server to search keyword data of the customer database based on keywords associated with the chosen book. Then, the database server: (1) determines one or more books having the most matching keywords and grades the books according to a calculated similarity rate, and (2) presents similarity information and a rating (for the chosen book) keyed to the closest book the customer has read.
In another embodiment, there is no initial book registration function as described above. The database server first provides (via keyword matching) a list of books related to a chosen book, allowing the customer to then select and register any books he has read from the list. Yet another embodiment employs a second algorithm to provide a different result; wherein data on related books is retrieved, sorted according to sales, keywords and other factors, and presented on a result list. An unsuitable result list can yield a new search based on different factors.
Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which:
FIG. 1 illustrates a block diagram of a computer network environment that implements embodiments of the present invention;
FIG. 2 illustrates an exemplary database server web page output for the book registration function, showing a preliminary input/request page to be filled in by the customer, according to one embodiment of the present invention;
FIG. 3 illustrates an exemplary database server web page output for the book registration function, showing a list of potential books for customer selection, according to one embodiment of the present invention;
FIG. 4 illustrates an exemplary database server web page output for the book rating function, showing a preliminary input/request page to be filled in by the customer, according to one embodiment of the present invention;
FIG. 5 illustrates an exemplary database server web page output for the book rating function, showing a list of results from the customer's search request (ideally including the intended book), according to one embodiment of the present invention;
FIG. 6 illustrates an exemplary database server web page output for the book estimating function, showing the chosen book and its correlation to the closest registered book, according to one embodiment of the present invention; and
FIG. 7 is a graph illustrating the range of keyword matching that corresponds to an acceptable range in an alternate algorithm used to provide a desirable search results, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In a network environment, a system and computer-based method for providing book ratings and/or recommendations that are customized based on user profiles and/or other information is described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one of ordinary skill in the art, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate explanation. The description of preferred embodiments is not intended to limit the scope of the claims appended hereto.
Hardware Overview
Aspects of the present invention may be implemented on one or more computers executing software instructions. According to one embodiment of the present invention, server and client (or customer) computer systems transmit and receive data over a computer network or standard telephone line. Internet-based communication via bi-directional networks is the preferred embodiment, although wireless and other data transmission systems not requiring a persistent cable connection are also contemplated. The steps of accessing, downloading, and manipulating the data, as well as other aspects of the present invention are implemented by central processing units (CPU) in the server and client computers executing sequences of instructions stored in a memory. The memory may be a random access memory (RAM), read-only memory (ROM), a persistent store, such as a mass storage device, or any combination of these devices. Execution of the sequences of instructions causes the CPU to perform steps according to embodiments of the present invention.
The instructions may be loaded into the memory of the server or client computers from a storage device or from one or more other computer systems over a network connection. For example, a client computer may transmit a sequence of instructions to the server computer in response to a message transmitted to the client over a network by the server. As the server receives the instructions over the network connection, it stores the instructions in memory. The server may store the instructions for later execution, or it may execute the instructions as they arrive over the network connection. In some cases, the downloaded instructions may be directly supported by the CPU. In other cases, the instructions may not be directly executable by the CPU, and may instead be executed by an interpreter that interprets the instructions. In other embodiments, hardwired circuitry may be used in place of, or in combination with, software instructions to implement the present invention. Thus, the present invention is not limited to any specific combination of hardware circuitry and software, nor to any particular source for the instructions executed by the server or client computers.
Additionally, although the embodiments of the present invention are described in relation to the rating and review of books, it should be understood that such embodiments are also directed to the revue of other types of written text-based, or graphical material, such as magazines, computer generated text, illustrations, and other types of written or graphical material.
Book Rating & Recommendation System
FIG. 1 is a block diagram of a computer network system that can be used to provide book ratings and/or recommendations that can be tailored to an individual customer and to other information, according to embodiments of the present invention. The book rating and recommendation system 100 of FIG. 1 enables book ratings and recommendations to be customized based on books that the customer has read, and more specifically, based on keywords or other information related to and/or representative of books that have been read by the customer and registered in the customer database 170 .
With regard to the system configuration, as seen in FIG. 1 , the book rating and recommendation system 100 can be discussed in terms of a server side having a database server 110 , a book database 160 , a customer database 170 , and a web server 120 that connects the database server 110 to a bidirectional network 130 . The database server 110 is shown connected directly to the databases 160 , 170 in this embodiment, however server connection to these or comparable databases can be made over any type of network as well. Data and information covering all books within the scope of the system are stored in the book database 160 . The customer database 170 contains data and information about the books that each individual customer or customer has read. In this embodiment, the database server 110 , the book database 160 and the customer database 170 may be addressed as a single unit and referred to as the rating/database system 150 , as seen in FIG. 1 . On the server side, many hardware configurations are possible; the web server 120 and the database server 110 can be the same computer, or the database server 110 and one of the databases can be one computer, etc. Essentially, these hardware components can be arranged in any functioning variation.
The database server 110 is a server system that is set up to handle book-related search requests from a customer. Access to the database server 110 , which may comprise one of several servers, is facilitated through web server 120 and a typical device known as a router (not shown) on the network 130 . The web server 120 and then the database server 110 interact with and/or receive interactive data from a customer, and they execute different server functionality, such as the database server 110 procedure of accessing requested book data/information from the book database 160 , as detailed below. Along with handling such requests for access of book data and information, the database server 110 also processes the customer's book data from the customer database 170 . All of the necessary data and information handled by both the web server 120 and the database server 110 , then, is generally transmitted by the web server 120 via the network by means of a known networking protocol standard, such as ftp (file transfer protocol).
As seen in FIG. 1 , the client side configuration includes a client 140 and an associated web browser process 142 . The client 140 can be a personal computer, a set top box, a computer/gaming device such as a Sony® PlayStation®2, a computing device of comparable capabilities, or any terminal device providing access to the system. The web browser process 142 is complimentary to a web server process 122 (executed by the web server 120 ) on the other side of the network 130 . In the presently preferred embodiment, the web server 120 is a World-Wide Web (WWW) server that stores data in the form of ‘web pages’ and transmits these pages as Hypertext Markup Language (HTML) files over the network 130 (preferably the Internet) to one or more of the client computers 140 . For this embodiment, the client computer 140 runs the “web browser” process 142 to access the web pages served by web server 120 . Additional web based content can be provided to client computer 140 by separate content providers, such as a supplemental server (not shown).
In other embodiments, the network 130 may be a Wide Area Network (WAN), a Local Area Network (LAN), or any combination of these and/or the Internet. The network is normally a bi-directional digital communications network that connects a client's terminal hardware with the web server 120 . With current technologies, a CATV (cable television) bi-directional network, ISDN (Integrated Services Digital Network), DSL (Digital Subscriber Line), or xDSL high-speed networks are examples of existing network infrastructures enabling the necessary network connections for implementing embodiments of the present invention, though they are not intended to be exclusive as to the types of networks capable of practicing the present invention.
In one embodiment of the present invention, the book rating and recommendation system of the currently preferred embodiment is realized by means of a graphical user interface (GUI) displayed on applicable computers or devices participating over the network. A primary objective of the invention is to supply a customer with the power of interactive capabilities, such as interactive means to register the books he or she has read. In general a web server, such as web server 120 in FIG. 1 , handles all of the initial functionality surrounding the GUI and associated interactivity of the customer.
There are multiple graphical user interfaces showing input and display information for the book registration and evaluation or rating functionalities, according to one or more embodiments of the present invention. As used herein, the term evaluation most properly includes both the rating and similarity data or estimates provided for a search item (i.e., book), although the term rating may also be used in this broad fashion to cover both rating and similarity data or estimates). In one embodiment, a customer initially registers books he has read. A customer then interacts with the rating functionality to produce a recommendation or estimate of interest. Preliminary and subsequent graphical user interfaces that provide interactive registration options and functionality for display at the client 140 are shown in FIGS. 2 and 3 . Three stages of graphical user interfaces that provide interactive rating and estimate functionality or options for display at the client 140 are shown in FIGS. 4 , 5 and 6 .
Book Registration Process
A graphical user interface displaying an exemplary web page output for book registration, provided to the client by the web server and showing a preliminary input/request page to be filled in by the customer, according to one embodiment of the present invention is shown in FIG. 2 . The preliminary registration GUI 200 of FIG. 2 is comprised of a header field 202 , an instruction field 204 , a book title section 206 , a book genre section 208 , a book author section 210 , a date of publication section 212 , a search button 214 , and a reset button 216 . The header field 202 recites “Registration of books you have read,” outlining the purpose of these two GUIs ( FIGS. 2 and 3 ) and the registration function in general. The instruction field 204 recites “Please enter at least one item and click on the ‘search’ button,” indicating the instruction for using the next four search fields to locate or identify books that the customer has read or has potentially read.
The four fields of FIG. 2 are the book title field 206 , the book genre field 208 , the book author field 210 , and the date of publication field 212 . Each of these four fields is comprised of a header line (stating ‘title,’ ‘genre,’ ‘author’ and ‘date of publication,’ respectively), and a text entry box, as is well known in the field of interactive web-based search environments. The reset button 216 is provided to clear unwanted entries from the text entry boxes of each of the above four fields. As one of the last steps of the customer registration process, the search button 214 can be selected to execute a search of the book database for books that satisfy the one or more criteria entered in the fields above.
In the preferred embodiment of the registration process, the search criteria is transmitted from the client 140 , over the World Wide Web, to the web server 120 ; the web server 120 then transmits the search criteria to the database server 110 . The database server 110 searches the book database 160 and retrieves information associated with the book(s) that the customer is attempting to register.
The book database 160 stores all of the various data for each of the books within the scope of the system. This book data includes at least a book identification category, a title category and a keyword category for rating, and may optionally include an author category, a summary category, a contents category, a publisher category, sales information, publication date, an evaluation by other customers category and/or any other book-related categories such as those currently being utilized by Amazon.com®. Once the database server locates one or more matching books from the book database 160 , information on these one or more matching books is transmitted to the web server for transmission over the network to the client.
A graphical user interface displaying an exemplary web page output for book registration provided to the client by the web server, showing the subsequent (to FIG. 2 ) input/request page to be addressed by the customer, according to one embodiment of the present invention is shown in FIG. 3 . The subsequent registration GUI 300 of FIG. 3 is comprised of a header field 302 , an instruction field 304 , a results list header box 306 , a results list 320 , one or more ‘more detail’ buttons 322 , and a registration button 330 . The header field 302 recites “Registration of books you have read,” outlining the purpose of these two GUIs and the registration function in general. The instruction field 304 recites “Please choose the book(s) you have read and click on the ‘registration’ button,” indicating the instruction for commencing the population of the customer database with the books that the customer has read.
Below the instruction field 304 , as seen in FIG. 3 , is the results list 320 and the results list header box 306 . The results list header box 306 contains the column headings of the particular categories, for the items in the result list, that are desired to communicate the potential books that the customer may have read. In the embodiment shown in FIG. 3 , the results list header box includes title and author headers of the potential books, as well as a check box column-header. The corresponding results list 320 contains the titles of the potential books (here, ABC and XYZ) as well as the authors of the potential books (here, Jeff Richards and Tom Bednash). The registration result list can contain a single book or a plurality of books. The result list 320 also contains check boxes selectable with a cursor/mouse that will flag that entry for registration into the customer database. All of the flagged potential book entries are then registered into the customer database when the registration button 330 is selected.
The above registration methodology lends itself well to preliminary search techniques that allow a customer to search a book database based on one or more fields, and then choose any books he has read from the potential books in the result list. With regard to the sequence of network environment steps, first the web server sends information regarding the preliminary registration GUI to the client 140 . The client 140 then displays this information, as seen in FIG. 2 . After input by the customer and transmission over the network, then, the web server 120 requests the database server 110 to search the book database 160 based on the inputted information. Next, the database server 110 searches the book database and sends the search results to the web server 120 . According to these results, the web server 110 generates a result list of books and sends it to the client 140 , who displays the list as seen in FIG. 3 . Once the customer selects the applicable books and clicks the ‘registration’ button, the selected book data is sent to the web server 120 . The web server 120 then requests the database server 110 to store the assigned book identification in the customer database 170 , associated with the customer ID or customer profile.
As used throughout this disclosure, the step of registering can consist of simply storing the information in question, or it can also include additional methodology such as that detailed throughout the specification and figures. A customer may also register books that he or she has read in a variety of other fashions, many of which are well known. The customer might simply be able to enter the book ISBN (International Standard Book Number), or if the books are present, the customer can use a barcode reader to scan the books in. Additionally, books may be registered by the recordation and transfer of such book information from purchase records. Such a purchase record cannot only be imported from online purchases, but also from offline purchases using any sort of identification record (i.e., credit card, etc.). In addition to registering books purchased at either conventional or online stores, a customer can also register any magazines that the customer has read or receives regularly.
Book Evaluation (Rating, Similarity and Estimation) Processes
A graphical user interface displaying an exemplary web page output for the book rating function, showing a preliminary input/request page to be filled in by the customer, according to one embodiment of the present invention, is shown in FIG. 4 . The preliminary rating GUI 400 of FIG. 4 is comprised of a header field 402 , a first instruction field 404 , a second instruction field 406 , a book title section 408 , a book genre section 410 , a book author section 412 , a date of publication section 414 , a search button 416 and a rest button 418 . The header field 402 recites “Rating the book for you,” outlining the purpose of this GUI, and also the rating function, in general. The first instruction field 404 of FIG. 4 delineates the first (preliminary) step of the rating function, reciting “Search for the book you are considering.” The second instruction field 406 of FIG. 4 provides specific instruction for the first step in the rating function, as outlined in the first instruction field 404 ; the specific instruction is “Please enter at least one item and click on the ‘search’ button.” The second instruction field 406 , then, indicates instruction for using the next four search fields to locate or identify books that the customer wishes to get an estimate for. The items to be entered in the search fields are detailed below.
The four search fields of FIG. 4 are the book title field 408 , the book genre field 410 , the book author field 412 , and the date of publication field 414 . Each of these four fields is comprised of a header line (stating ‘title,’ ‘genre,’ ‘author’ and ‘date of publication,’ respectively), and a text entry box, as is well known in the field of interactive web-based search environments. The reset button 418 is provided to clear unwanted entries from the text entry boxes of each of the above four fields. Finally, the search button 416 is provided to execute a search of the book database for books that satisfy the one or more criteria entered in the fields above.
A graphical user interface displaying an exemplary web page output for the book rating function, provided to the client by the web server and showing a subsequent input/request page to be filled in by the customer, according to one embodiment of the present invention, is shown in FIG. 5 . The subsequent rating GUI 500 of FIG. 5 has a header field 502 , a first instruction field 504 , a second instruction field 506 , a results list header box 508 , a results list 520 , one or more ‘more detail’ buttons 528 , and a ‘get estimate’ button 530 . The header field 502 recites “Rating the book for you,” as with FIG. 4 . The first instruction field 504 of FIG. 5 delineates the second (subsequent) step of the rating function, reciting “Identify the book.” The second instruction field 506 of FIG. 5 provides specific instruction for this second step in the rating function (per first intruction field 504 of FIG. 5 ); the specific instruction is “Please choose the book you are looking for and click on the ‘get estimate’ button. The second instruction field 506 , then, indicates instruction for selecting one or more of the books from the results list 520 , which is described in detailed below.
The results list 520 and the results list header box 508 are located below the second instruction field 506 in the embodiment of FIG. 5 . The results list header box 508 of FIG. 5 contains the column headings of the particular categories, for the items in the result list 520 , that are desired to communicate the potential books that the customer might consider receiving a rating on. In the embodiment shown in FIG. 5 , the results list header box includes title and author headers of the potential books, as well as a check box column-header. The corresponding results list 520 contains the titles of the potential books (here, ABC and XYZ) as well as the authors of the potential books (here, Jeff Richards and Tom Bednash). The result list 520 also contains check boxes selectable with a cursor/mouse that will flag that entry for getting an estimate or rating. When the ‘get estimate’ button 590 is selected, the flagged book entry is then processed by the database server to determine an estimate or rating according to the respective algorithm. The resultant estimate or rating is then displayed to the customer, as shown in FIG. 6 and described next.
According to one embodiment of the present invention, a graphical user interface that shows an exemplary web page output displaying of an estimate or rating of the book that has been determined (by the database server) to be an appropriate result for the book the customer has selected, is shown in FIG. 6 . The estimate GUI 600 of FIG. 6 is comprised of a header field 602 , a book identifier field 604 , a book information field 606 , a first ‘more detail’ button 608 , a value field 612 , a similarity field 614 , and a second ‘more detail’ button 620 . The header field 602 recites “Estimate of the book for you,” explaining that the information below describes, with respect to the book selected by the customer, an estimate keyed to the most appropriate book registered by the customer. Field headings such as ‘title’ and ‘author’ are contained in the book identifier field 604 for the purpose of indicating the corresponding information in the book information field 606 . Data corresponding to these field headings are then located in the book information field 606 (i.e., ‘xyz’ and ‘Tom Bednash’ in FIG. 6 ). The first ‘more detail’ button 608 may be selected by a customer to show further details of the prospective book, such as publication information, a book summary or the like.
The value field 612 and the similarity field 614 are located below these book-related fields on the estimate GUI 600 . The value field 612 supplies the customer with an overall rating of the estimated book; the gauge on the right side of this field (i.e., 0–5 stars, etc.) provides the customer with some sort of general value of reading the book, as determined by empirical techniques such as collaborative filtering. The similarity field 614 is also located below the book-related fields, and provides a measure of how closely the estimated book matches the chosen book. According to the method used, the magnitude of this measure correlates to how closely the estimated book matched the chosen book, and can be expressed in simple percentages. The second ‘more detail’ button 620 can be located in the lower right hand corner, near to the similarity field 614 , and is selected by a customer to provide further detail with regard to the book upon which the estimate has been keyed.
There are usually six steps in the preferred rating/estimate functionality associated with FIGS. 4–6 . A customer first enters information concerning a book, about which the customer is wondering whether he or she should read. This information is entered at the client via the interactive GUI of FIG. 4 . Next, the web server requests the database server to search the book database based on the information sent by the customer. These search results are then sent to the web server, and the web server sends corresponding GUI information to the client. According to this GUI information, the client displays the subsequent rating GUI 500 shown in FIG. 5 . From the subsequent rating GUI 500 screen, the customer chooses or confirms the book that he or she is considering.
By using this chosen book identity, then, the web server requests the database server to search all keyword data of the customer database based on the keywords of the chosen book data. Then the database server finds a book that has the most keywords in common to the chosen book keywords. The database server can also calculate the similarity rate of the keywords, and grades the chosen book according to the rate.
Instantaneous Registration of Relevant Books, and Algorithms
According to an alternate embodiment of the present invention, a customer does not have to register the books that he or she has read in advance of the book rating process. In the above-discussed rating/estimate process, the database server first finds the books that are related to the chosen book according to the keywords of the chosen (to be estimated) book. The list of the related books is then displayed. From this display, the customer checks all of the books he or she has read off of the list. After this alternate registration process, the rating and estimate processes are identical to the previous embodiment described above. For this alternative registration process, the checked books may be registered in the customer database so that the customer does not have to input the same books. When the list of related books is displayed the next time, the registered books should be checked before the customer's input (checking).
Another alternate embodiment of the present invention contemplates the scenario in which a customer has not identified a particular book for rating and estimation. In this situation, the rating algorithm is different from the algorithm used in the preferred embodiment above. A four-step algorithm is used to find a book that suits a customer's taste. In the first step, the database server narrows the object field based on keywords or natural language inputted by a customer, and then the data of the books that the customer is interested in is extracted from the book database. In the second step, the data is sorted according to sales.
In the third step, book data having both too many and too few keywords equal to the keywords in the customer's book data are eliminated by use of the keyword matching. FIG. 7 shows a keyword-match graph 700 illustrating a representative bell curve 706 associated with such keyword search results, according to this embodiment. Graph 700 has, as its x-axis, the ‘matching rate’ 704 or quantity of keywords that match, with the greatest number of matches extending to the right. The y-axis of keyword-match graph 700 reflects the ‘result rate’ 702 or the quantity of books that satisfy the corresponding rate (x-axis) value of matched keywords. For example, books within the acceptable range 708 of matched keywords share a certain percentage of the sought keywords, with this range being reflected on the x-axis (i.e., perhaps a range of approximately 60–75%, as seen in FIG. 7 ). As described above, the algorithm rejects books sharing too few keywords 710 as well as books sharing too many keywords 712 , leaving books within the acceptable range 708 . The matching rate of keywords (x-axis), then, relates to the result rate or quantity of books by a bell curve relationship 706 . This is simply to say that a greater number of results or books will share a middle range of keyword with the chosen book, as seen in the center (highest point) of the curve, with the number of results or books tapering off as the matching rate either increases or decreases.
The fourth step is essentially a reiteration of the first three steps if the particular results are found to be unacceptable. If the results of step three are not suitable, the keywords are exchanged to another data type (i.e., author, publisher, etc.) and the matching procedure is executed again.
In the foregoing, a system has been described for providing book ratings and/or recommendations that can be customized based on customer profiles or other criteria. Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
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A system for providing customized text content ratings and recommendations based on information concerning the text content that a customer has previously read. The system includes a book database, a customer database, a database server, and a web server. The customer performs a book registration function followed by a book rating function. In the registration function, information regarding texts that the customer has previously read is compiled and stored in the customer database. In the rating function, the customer establishes text product that he is considering buying. The server searches keyword data of the customer database based on keywords associated with the chosen product. The database server determines one or more books or other text product having the most matching keywords and ranks the products according to a scale, and presents a rating information for the chosen text product keyed to the closest text the customer has read.
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[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/706,134 filed Aug. 4, 20005.
BACKGROUND OF THE INVENTION
[0002] 1 . Field of the Invention
[0003] The present invention relates to processes for dewaxing hydrocarbon feedstocks employing a combination of zeolites MTT and GON as a catalyst.
[0004] 2. State of the Art
[0005] Because of their unique sieving characteristics, as well as their catalytic properties, crystalline molecular sieves and zeolites are especially useful in applications such as hydrocarbon conversion, including dewaxing of hydrocarbon feedstocks. Zeolites may also be used for reducing the haze point in feedstocks such as bright stock. (See, for example, U.S. Pat. No. 6,051,129, issued Apr. 18, 2000 to Harris et al., in which zeolite EU-1 in combination with ZSM-48 and/or SSZ-32 is used to reduce haze in bright stock. This patent is incorporated by reference herein in its entirety.) Although many different crystalline molecular sieves have been disclosed, there is a continuing need for new zeolites with desirable properties for hydrocarbon and chemical conversions, and other applications.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, there is provided a dewaxing process comprising contacting a hydrocarbon feedstock under dewaxing conditions with a catalyst comprising a combination of zeolites having the MTT and GON framework topologies defined by the connectivity of their tetrahedral atoms (referred to herein simply as MTT and GON). The MTT and GON zeolites are preferably predominantly in the hydrogen form.
[0007] The present invention also includes a process for improving the viscosity index of a dewaxed product of waxy hydrocarbon feeds comprising contacting the waxy hydrocarbon feed under isomerization dewaxing conditions with a catalyst comprising a combination of zeolites MTT and GON, preferably predominantly in the hydrogen form.
[0008] The present invention further includes a process for producing a C 20+ lube oil from a C 20+ olefin feed comprising isomerizing said olefin feed under isomerization conditions over a catalyst comprising at least one Group VIII metal and a combination of zeolites MTT and GON. The zeolites may be predominantly in the hydrogen form.
[0009] In accordance with this invention, there is also provided a process for catalytically dewaxing a hydrocarbon oil feedstock boiling above about 350° F. and containing straight chain and slightly branched chain hydrocarbons comprising contacting said hydrocarbon oil feedstock in the presence of added hydrogen gas at a hydrogen pressure of about 15-3000 psi with a catalyst comprising at least one Group VIII metal and a combination of zeolites MTT and GON, preferably predominantly in the hydrogen form.
[0010] Further included in this invention is a process for isomerization dewaxing a raffinate comprising contacting said raffinate in the presence of added hydrogen with a catalyst comprising at least one Group VIII metal and a combination of zeolites MTT and GON. The raffinate may be bright stock, and the zeolites may be predominantly in the hydrogen form.
[0011] The present invention also provides a process for reducing the cloud point of a hydrocarbon feed comprising contacting a hydrocarbon oil feedstock which has a major portion boiling over 100° F. (538° C.) with a catalyst system comprising a combination of a zeolite having MTT topology and a zeolite having GON topology, wherein at least a portion of said feedstock is converted.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In hydrodewaxing, one target is to hydroconvert the longest hydrocarbons in the feed. If these are left unconverted, they can cause haze in the product. The haze is quantified by cloud point.
[0013] The Gibbs free energy of adsorption for n-alkanes quantifies the ability of a particular zeolite structure for selectively absorbing and converting n-alkanes. In order to reduce the cloud point, it is advantageous to employ zeolites that impose a significantly lower Gibbs free energy of adsorption on a long as opposed to short n-alkane.
[0014] Gibbs free energies of adsorption can be determined with consistency and accuracy. Examples of these determinations are presented in “Journal of Physical Chemistry B” (2004), 108(33), 12301-12313. These determinations indicate that the difference between absorbing and converting a long n-alkane and a short n-alkane is only minimally different for MTT-type zeolites. The GON-type zeolites exhibit the maximum difference in Gibbs free energy of adsorption between long and short n-alkanes. It is surprising the Gibbs free energies of adsorption of these zeolites demonstrate such a markedly different response to the variation in n-alkane chain length. By employing GON-type zeolites in addition to MTT-type zeolites, the conversion of heavy wax (long n-alkanes) can be significantly increased, thereby lowering the cloud point of the product.
[0015] Zeolites having the MTT framework topology are known. For example, the zeolite designated “SSZ-32” and methods for making it are disclosed in U.S. Pat. No. 5,053,373, issued Oct. 1, 1991 to Zones. This patent discloses the preparation of zeolite SSZ-32 using an N-lower alkyl-N′-isopropylimidazolium cation as an organic structure directing agent (SDA), sometimes called a templating agent. U.S. Pat. No. 4,076,842, issued Feb. 28, 1978 to Plank et al., discloses the preparation of the zeolite designated “ZSM-23”, a zeolite with a structure similar to SSZ-32, using a cation derived from pyrrolidine as the SDA. Zeolites SSZ-32 and ZSM-23 are commonly referred to as having the MTT framework topology. Both of the aforementioned patents are incorporated herein by reference in their entirety. In addition, R. Szostak, Handbook of Molecular Sieves, 1992 lists zeolites designated ISI-4 and KZ-1 as having the MTT topology. The zeolite designated EU-13 is described in C. Baerlocher et al., Atlas of Zeolite Framework Types, 5 th Revised Edition, 2001, International Zeolite Association as having the MTT topology.
[0016] Dewaxing processes using MTT zeolites are known. For example, U.S. Pat. No. 4,222,855, issued Sept. 16, 1980 to Pelrine et al., discloses a dewaxing process using ZSM-23 or ZSM-35. Likewise, U.S. Pat. No. 5,376,260, issued Dec. 27, 1994 to Santilli et al., discloses a dewaxing process using a catalyst containing SSZ-32. U.S. Pat. No. 6,663,768, issued Dec. 16, 2003 to Miller, also discloses a dewaxing process which uses ZSM-23 or SSZ-32 in the catalyst. U.S. Pat. No. 4,601,993, issued Jul. 22, 1986 to Chu et al., discloses a dewaxing process using a combination of ZSM-23 and zeolite Beta.
[0017] Zeolites having the GON topology are also known. For example, the zeolite designated “GUS-1” and a method of making it is disclosed in Plevert et al., “GUS-1: a mordenite-like molecular sieve with the 12-ring channel of ZSM-12”, Chem. Commun., 2000, pp. 2363-2364 which in incorporated herein by reference in its entirety. GON-type zeolites are 12 ring/8 ring zeolites with uni-dimensional channels.
[0018] The MTT and GON zeolites are used in the present invention in combination. As used herein, the term “combination” includes mixtures of the zeolites, layers of the zeolites, or any other configuration in which the feed comes in contact with both zeolites. For example, the combination may be a graduated mixture in which the feed initially contacts a portion of the mixture which comprises essentially all one of the zeolites. The concentration of the second zeolite can be gradually increased, and the concentration of the first zeolite gradually decreased, in successive portions of the mixture until the mixture becomes essentially all second zeolite. Depending on the feed, reaction conditions, and desired product, the combination may be such that the feed initially contacts the MTT zeolite first or the GON zeolite first.
[0019] The combination of MTT and GON zeolites may also be used in layers. The use of catalyst layers is disclosed in U.S. Pat. No. 5,149,421, issued Sept. 22, 1992 to Miller, which is incorporated by reference herein its entirety. The order of the layers may be MTT in a first layer and GON in a subsequent layer, or vice versa.
[0020] Depending upon the nature of the feed and the desired products, the MTT and GON zeolites can be employed over a wide range of concentrations. The catalyst combination may comprise 1-99 weight percent MTT zeolite and 99-1 weight percent GON zeolite. Preferably, the crystal size of the zeolites is less than 0.1 micron, i.e., the longest dimension of the crystal is less than 0.1 micron.
[0021] The crystalline MTT and GON can be used as-synthesized, but preferably will be thermally treated (calcined). Usually, it is desirable to remove the alkali metal cation by ion exchange and replace it with hydrogen, ammonium, or any desired metal ion. The zeolite can be leached with chelating agents, e.g., EDTA or dilute acid solutions, to increase the silica to alumina mole ratio. The zeolite can also be steamed; steaming helps stabilize the crystalline lattice to attack from acids.
[0022] The zeolite can be used in intimate combination with hydrogenating components, such as tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese or a noble metal, such as palladium or platinum.
[0023] Metals may also be introduced into the zeolite by replacing some of the cations in the zeolite with metal cations via standard ion exchange techniques (see, for example, U.S. Pat. No. 3,140,249 issued Jul. 7, 1964 to Plank et al.; U.S. Pat. No. 3,140,251 issued Jul. 7, 1964 to Plank et al.; and U.S. Pat. No. 3,140,253 issued Jul. 7, 1964 to Plank et al.). Typical replacing cations can include metal cations, e.g., rare earth, Group IA, Group IIA and Group VIII metals, as well as their mixtures. Of the replacing metallic cations, cations of metals such as rare earth, Mn, Ca, Mg, Zn, Cd, Pt, Pd, Ni, Co, Ti, Al, Sn and Fe are particularly preferred.
[0024] The hydrogen, ammonium and metal components can be ion-exchanged into the zeolites. The zeolites can also be impregnated with the metals, or the metals can be physically and intimately admixed with the zeolites using standard methods known to the art.
[0025] Typical ion-exchange techniques involve contacting the zeolites with a solution containing a salt of the desired replacing cation or cations. Although a wide variety of salts can be employed, chlorides and other halides, acetates, nitrates and sulfates are particularly preferred. The zeolites are usually calcined prior to the ion-exchange procedure to remove the organic matter in the channels and on the surface, since this results in a more effective ion exchange. Representative ion exchange techniques are disclosed in a wide variety of patents including U.S. Pat. No. 3,140,249 issued Jul. 7, 1964 to Plank et al.; U.S. Pat. No. 3,140,251 issued Jul. 7, 1964 to Plank et al. and U.S. Pat. No. 3,140,253 issued on Jul. 7, 1964 to Plank et al.
[0026] Following contact with the salt solution of the desired replacing cation, the zeolites are typically washed with water and dried at temperatures ranging from 65° C. to about 200° C. After washing, the zeolites can be calcined in air or inert gas at temperatures ranging from about 200° C. to about 800° C. for periods of time ranging from 1 to 48 hours, or more, to produce a catalytically active product especially useful in hydrocarbon conversion processes.
[0027] The zeolites can be formed into a wide variety of physical shapes. Generally speaking, the zeolite can be in the form of a powder, a granule or a molded product, such as extrudate having a particle size sufficient to pass through a 2-mesh (Tyler) screen and be retained on a 400-mesh (Tyler) screen. In cases where the catalyst is molded, such as by extrusion with an organic binder, the zeolite can be extruded before drying, or dried or partially dried and then extruded.
[0028] The zeolites can be composited with other materials resistant to the temperatures and other conditions employed in organic conversion processes. Such matrix materials include active and inactive materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and metal oxides. Examples of such materials and the manner in which they can be used are disclosed in U.S. Pat. No. 4,910,006, issued May 20, 1990 to Zones et al. and U.S. Pat. No. 5,316,753, issued May 31, 1994 to Nakagawa, both of which are incorporated by reference herein in their entirety.
[0029] The MTT and GON zeolites are used in dewaxing hydrocarbonaceous feedstocks. Hydrocarbonaceous feedstocks contain carbon compounds and can be from many different sources, such as virgin petroleum fractions, recycle petroleum fractions, shale oil, liquefied coal, tar sand oil, synthetic paraffins from NAO, recycled plastic feedstocks, bright stock, Fischer-Tropsch waxes (i.e., synthetic waxes derived from a Fischer Tropsch process, preferably an oxygenate-containing Fischer Tropsch process, boiling below about 700° F. (371° C.)) and, in general, can be any carbon containing feedstock susceptible to zeolitic catalytic dewaxing reactions. Depending on the type of processing the hydrocarbonaceous feed is to undergo, the feed can contain metal or be free of metals. It can also have high or low nitrogen or sulfur impurities. It can be appreciated, however, that in general processing will be more efficient (and the catalyst more active) the lower the metal, nitrogen, and sulfur content of the feedstock. Preferably, after treating the feedstock in accordance with the present invention, the cloud point of the feedstock (depending on its original composition) is reduced to not more than 10° C.
[0030] The dewaxing of hydrocarbonaceous feeds can take place in any convenient mode, for example, in fluidized bed, moving bed, or fixed bed reactors depending on the types of process desired. The formulation of the catalyst particles will vary depending on the conversion process and method of operation.
[0031] Typical dewaxing reaction conditions which may be employed when using catalysts comprising a combination of zeolites MTT and GON in the dewaxing reactions of this invention include a temperature of about 200-475° C., preferably about 250-450° C., a pressure of about 15-3000 psig, preferably about 200-3000 psig, and a LHSV of about 0.1-20, preferably 0.2-10.
[0032] The MTT and GON combination, preferably predominantly in the hydrogen form, can be used to dewax hydrocarbonaceous feeds by selectively removing straight chain paraffins. Typically, the viscosity index of the dewaxed product is improved (compared to the waxy feed) when the waxy feed is contacted with a combination of zeolites MTT and GON under isomerization dewaxing conditions.
[0033] The catalytic dewaxing conditions are dependent in large measure on the feed used and upon the desired pour point. Hydrogen is preferably present in the reaction zone during the catalytic dewaxing process. The hydrogen to feed ratio is typically between about 500 and about 30,000 SCF/bbl (standard cubic feet per barrel), preferably about 1000 to about 20,000 SCF/bbl. Generally, hydrogen will be separated from the product and recycled to the reaction zone. Typical feedstocks include light gas oil, heavy gas oils and reduced crudes boiling above about 350° F. (177° C.).
[0034] A typical dewaxing process is the catalytic dewaxing of a hydrocarbon oil feedstock boiling above about 350° F. (177° C.) and containing straight chain and slightly branched chain hydrocarbons by contacting the hydrocarbon oil feedstock in the presence of added hydrogen gas at a hydrogen pressure of about 15-3000 psi with a catalyst comprising a combination of zeolites MTT and GON and at least one Group VIII metal.
[0035] The hydrodewaxing catalyst may optionally contain a hydrogenation component of the type commonly employed in dewaxing catalysts. See the aforementioned U.S. Pat. No. 4,910,006 and U.S. Pat. No. 5,316,753 for examples of these hydrogenation components.
[0036] The hydrogenation component is present in an effective amount to provide an effective hydrodewaxing and hydroisomerization catalyst preferably in the range of from about 0.05 to 5% by weight. The catalyst may be run in such a mode to increase isodewaxing at the expense of cracking reactions.
[0037] The feed may be hydrocracked, followed by dewaxing. This type of two stage process and typical hydrocracking conditions are described in U.S. Pat. No. 4,921,594, issued May 1, 1990 to Miller, which is incorporated herein by reference in its entirety.
[0038] The combination of MTT and GON may also be used to dewax raffinates, including bright stock, under conditions such as those disclosed in U.S. Pat. No. 4,181,598, issued Jan. 1, 1980 to Gillespie et al., which is incorporated by reference herein in its entirety.
[0039] It is often desirable to use mild hydrogenation (sometimes referred to as hydrofinishing) to produce more stable dewaxed products. The hydrofinishing step can be performed either before or after the dewaxing step, and preferably after. Hydrofinishing is typically conducted at temperatures ranging from about 190° C. to about 340° C. at pressures from about 400 psig to about 3000 psig at space velocities (LHSV) between about 0.1 and 20 and a hydrogen recycle rate of about 400 to 1500 SCF/bbl. The hydrogenation catalyst employed must be active enough not only to hydrogenate the olefins, diolefins and color bodies which may be present, but also to reduce the aromatic content. Suitable hydrogenation catalyst are disclosed in U.S. Pat. No. 4,921,594, issued May 1, 1990 to Miller, which is incorporated by reference herein in its entirety. The hydrofinishing step is beneficial in preparing an acceptably stable product (e.g., a lubricating oil) since dewaxed products prepared from hydrocracked stocks tend to be unstable to air and light and tend to form sludges spontaneously and quickly.
[0040] Lube oil may be prepared using a combination of zeolites MTT and GON. For example, a C 20+ lube oil may be made by isomerizing a C 20+ olefin feed over a catalyst comprising a combination of zeolites MTT and GON, preferably predominantly in the hydrogen form, and at least one Group VIII metal. Alternatively, the lubricating oil may be made by hydrocracking in a hydrocracking zone a hydrocarbonaceous feedstock to obtain an effluent comprising a hydrocracked oil, and catalytically dewaxing the effluent at a temperature of at least about 400° F. (204° C.) and at a pressure of from about 15 psig to about 3000 psig in the presence of added hydrogen gas with a catalyst comprising a combination of zeolites MTT and GON, preferably predominantly in the hydrogen form, and at least one Group VIII metal.
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The present invention relates to the use of a combination of zeolites having the MTT and GON framework topologies defined by the connectivity of their tetrahedral atoms as a catalyst in a process for dewaxing hydrocarbon feedstocks.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to craft hoops, and, more particularly, to a craft hoop clamp.
2. Description of the Related Art
Craft hoops also known as embroidery hoops or knitting rings, generally include concentric inner and outer hoops. The inner hoop has a fixed diameter and the outer hoop has an adjustable diameter. Material, such as fabric, is placed upon the inner hoop while the outer hoop is placed over the fabric and around the inner hoop. The outer hoop is then adjusted such that the outer hoop fits snugly against the material and the inner hoop so as to hold the material between the inner and outer hoops. Craft work is then undertaken on the fabric held between the inner hoop and outer hoop.
Embroidery has been traditionally used to decorate clothing and household furnishings including such items as table linens, towels, bedding and decorative items. Most embroidered products are assembled from several individual pieces of fabric. Prior to assembling each piece of fabric, upon which an embroidered design or logo is to be placed, the fabric is inserted into an embroidery hoop and secured to the hoop. The hoop is then embroidered either by hand or with an embroidery machine.
Embroidery hoops have been known and used in both home and in factories for many years. Spring type embroidery hoops are used for hand and machine operations. Spring type hoops tension the outer hoop entirely by the resilience of the spring. More commonly, embroidery hoops such as circular or oval shaped units have an outer threaded fastener that traverses the split in the outer hoop for tightening the outer hoop against the inner hoop.
The problem with conventional embroidery hoops or craft hoops has been the difficulties with the tensioning mechanism. The screw type tensioning mechanism generally requires the use of two hands to position and tighten the threaded bolt with a wing nut. The disadvantage of the spring type embroidery hoop is that the tension is related only to the spring force and the force from the spring decreases as the hoop is drawn together.
What is needed in the art is a tensioning device which is easily operable with one hand and adjustable to provide variable tension on a craft hoop.
SUMMARY OF THE INVENTION
The present invention provides an adjustable tensioning device for a craft hoop assembly.
The invention comprises, in one form thereof, a craft hoop assembly including a split hoop having a first end and a second end and a clamping mechanism connected to the first end, the clamping mechanism having a first pivot point and a second pivot point, the first pivot point associated with the first end, the second pivot point associated with the second end.
An advantage of the present invention is that a split craft hoop can be secured around an inner hoop using only one hand.
Another advantage is that a conventional outer hoop can be retrofitted with a kit of the present invention.
Yet another advantage is that the craft hoop clamping method provides an adjustable over-center type mechanism for tensioning the outer hoop.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of an embodiment of a craft hoop clamping apparatus of the present invention;
FIG. 2 is an exploded perspective view of the craft hoop clamping apparatus shown in FIG. 1;
FIG. 3 is a partially sectionalized view of the craft hoop clamping apparatus shown in FIGS. 1 and 2;
FIG. 4 is a partially sectionalized view of the craft hoop clamping apparatus shown in FIGS. 1-3;
FIG. 5 is a partially sectionalized side view of the craft hoop clamping apparatus of FIGS. 1-4; and
FIG. 6 is a view of another embodiment of the clamping apparatus in the form of a kit for a conventional craft hoop assembly.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and, more particularly to FIGS. 1 and 2, there is shown an embodiment of a craft hoop clamping apparatus 10 of the present invention, which generally includes split hoop 12 and over-center clamp mechanism 14 .
Split hoop 12 is a generally circular hoop that has a split 16 along the circumference thereof. Split hoop 12 may be made from a variety of materials such as wood, plastic or carbon fiber. The inner surface, although shown as smooth in FIG. 1, may include ridges to better grip a fabric. Although split hoop 12 is shown as a circular hoop other shapes such as elliptical or quasi-rectangular may be incorporated as a part of craft hoop clamping apparatus 10 . Alternatively, more than one over-center clamp mechanism 14 may be applied along the circumference of a split hoop.
Over-center clamp mechanism 14 includes retaining block 18 , recessed block 20 , over-center tensioner 22 , tensioning rod retainer 24 , tensioning rod 26 , rod spring 28 and expansion spring 30 . Retaining block 18 is attached to one end of split hoop 12 and retaining block 18 is aligned with recessed block 20 . Retaining block 18 includes an opening 36 through which tensioning rod 26 is disposed. Tensioning rod 26 is retained by retaining block 18 to thereby provide tension on split hoop 12 . Recessed block 20 is attached to another end of split hoop 12 and is aligned with retaining block 18 . Recessed block 20 includes elongated opening 38 through which tensioning rod 26 is disposed and recess 40 which serves as a bearing surface for tensioner 22 .
Over-center tensioner 22 includes bearing surface 42 , handle 44 and slot 48 . Axis A and axis B denote two pivot points about which portions of over-center tensioner 22 rotate. Bearing surface 42 contacts recess 40 to provide pressure against recessed block 20 , thereby placing tension on split hoop 12 . Bearing surface 42 is part of a circumference of a substantially circular portion of over-center tensioner 22 that rotates about axis A. Handle 44 provides a mechanical advantage to over-center tensioner 22 and allows an operator to thereby put pressure on tensioning rod 26 . In a preferred embodiment of the present invention handle 44 exceeds two inches in length. Threaded portion 46 of tensioning rod retainer 24 engages tensioning rod 26 in an adjustable manner. Tensioning rod retainer 24 is retained in over-center tensioner 22 by the connection with tensioning rod 26 . Tensioning rod retainer 24 rotates about axis B such that when handle 44 is moved to a position adjacent to recessed block 20 , that tensioning rod 26 crosses axis A, thereby biasing handle 44 to remain adjacent to recessed block 20 . Such an arrangement is known as an over-center condition. Slot 48 allows space for tensioning rod 26 to travel when over-center tensioner 22 is rotated. Tensioning rod retainer 24 is positioned off center relative to bearing surface 42 to provide a camming type action as over-center tensioner 22 is rotated. Over-center tensioner 22 can be in the form of a cam clamp or a toggle clamp.
Tensioning rod 26 includes a retaining end 32 in the form of a ball 32 on one end thereof and a threaded end 34 on an opposite end thereof. Retaining end 32 has a retaining surface for rod spring 28 to rest against. The portion of retaining end 32 directed away from tensioning rod 26 may include a tab that protrudes or a slot therein, thereby accommodating a rotational adjustment of tensioning rod 26 . Rod spring 28 is positioned on tensioning rod 26 prior to tensioning rod 26 being inserted into retaining block 18 . Rod spring 28 comes into contact with a surface of retaining block 18 and provides tension within over-center clamp mechanism 14 while it is unlatched. Tensioning rod 26 traverses the inner diameter of expansion spring 30 , which is positioned between retaining block 18 and recessed block 20 . Expansion spring 30 is positioned to cause split hoop 12 to part along split 16 when tension on tensioning rod 26 is released. Tensioning rod 26 also is disposed through elongated opening 38 of recessed block 20 . Threaded end 34 adjustably engages threaded portion 46 of tensioning rod retainer 24 . Tensioning rod 26 , also known as tensioning member 26 , may be embodied as a flexible member such as a cable with retaining end 32 connected thereto.
Alternatively, over-center clamp mechanism 14 may be configured to provide a compressive force on an inner split hoop. The compressive force is exerted against an outer hoop.
Now, additionally referring to FIGS. 3-5, there is shown the operation of craft hoop clamping apparatus 10 . In FIG. 3 there is shown inner hoop 50 surrounded with craft hoop assembly 10 in an unlatched position. As handle 44 of over-center tensioner 22 is rotated in direction R tensioning rod 26 is drawn against retaining block 18 causing split 16 to narrow. As over-center tensioner 22 is rotated tensioning rod 26 , as shown in FIG. 4, is angularly offset. As shown in FIG. 5 over-center tensioner 22 is in a latched position, with tensioning rod 26 being slightly above centerline A thereby keeping over-center tensioner 22 in the latched position. Split 16 is substantially reduced in width when over-center clamp mechanism 14 is in the latched position, thereby causing split hoop 12 to be drawn tight against inner hoop 50 .
Craft hoop assembly 10 is operated by placing over-center tensioner 22 in an unlatched position. Fabric is placed over inner hoop 50 and arranged as required by the user who may be an embroiderer or quilter. Outer hoop 12 is then placed over the fabric locating outer hoop 12 substantially concentric with inner hoop 50 . Over-center tensioner 22 is then rotated, thereby placing tension on tensioning rod 26 , causing split hoop 12 to close split 16 and securing tension against the fabric placed over inner hoop 50 . Over-center tensioner 22 is rotated until it is in a latched position to securely hold the fabric placed over inner hoop 50 . Retaining rod 26 is adjustable within tensioning rod retainer 24 thereby providing an adjustable amount of tension on split hoop 12 .
Now, additionally referring to FIG. 6, there is illustrated another embodiment of the present invention in the form of a craft hoop clamping kit 110 shown with a conventional craft hoop. A conventional craft hoop includes outer split hoop 112 , protrusion 122 , protrusion 124 and a bolt with wing nut 126 . Protrusions 122 and 124 are respectively connected to an end of split hoop 112 and bolt/wing nut 126 is disposed therethrough, the combination thereby accommodating the tensioning of split hoop 112 . Craft hoop clamping kit 110 , which is substantially similar to over-center clamp mechanism 14 , is installed by first removing winged bolt 126 from protrusions 122 and 124 . Retaining rod 26 is unscrewed from tensioning rod retainer 24 . Tensioning rod 26 is then routed through protrusions 122 and 124 where bolt 126 had been and tensioning rod 26 is then re-threaded into tensioning rod retainer 24 . Retaining block 118 and recessed block 120 are shortened versions of retaining block 18 and recessed block 20 of the previous embodiment. The surface of recess block 120 that bears upon protrusion 124 is slidingly engaged to allow tensioner 22 to operate in a camming type manner.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
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A craft hoop assembly including a split hoop having a first end and a second end and a clamping mechanism connected to the first end, the clamping mechanism having a first pivot point and a second pivot point, the first pivot point associated with the first end, the second pivot point associated with the second end.
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FIELD OF THE INVENTION
The present invention relates generally to aqueous solutions to stabilize proteins and peptides. In particular this invention relates to aqueous calibrator and control solutions for diagnostic assays for proteins and peptides, particularly: troponin, myoglobin, CK, CK isoenzymes, LD, LD isoenzymes and myosin, and fragments thereof and most particularly troponin and troponin fragments including synthetic and recombinant peptides of troponin.
BACKGROUND OF THE INVENTION
A number of physiological conditions and states are associated with increased levels of CK-MB, myoglobin, myosin and troponin. Elevated levels generally are associated with myocardial infarction and other conditions which result in myocardial injury.
Principally because of the association of increased levels of these proteins with acute myocardial infarction, tests for acute myocardial infarction (AMI) have been or are being devised to determine the level of these proteins in bodily fluids. Thus, these proteins have become known as cardiac markers.
Acute myocardial infarction continues to be a major cause of illness and death, particularly in the United States. An estimated 1.5 million admissions to hospitals can be attributed to suspected myocardial infarction or related cardiac disease. Of these patients, only roughly 25% are actually suffering an AMI while another 30% are admitted with unstable angina, 20% have stable coronary artery disease (CA), and the remaining 25% have no CAD. Differentiation of those patients who require immediate care and hospitalization from those who are not in danger is of great value in providing effective medical care, reducing hospitalization costs, and effectively managing hospital facilities. Current studies indicate that early intervention is critical for optimum therapeutic measures.
These therapeutic measures have the potential to restore blood flow to the damaged myocardium, limit the size of the infarct, and thus preserve cardiac function. New therapeutic intervention mechanisms, specifically thrombolytic agents such as streptokinase and tissue plasminogen activator are available to restore coronary artery blood flow and reduce the incidence of morbidity. Most clinicians believe that intervention must take place as soon as possible and should be well within the first four hours after the onset of chest pain.
Thus, an ideal cardiac marker or combination of markers should be cardiac tissue specific, it should be diagnostic within four hours after the onset of AMI, it should remain somewhat elevated for at least seven days after AMI but it should detect reinfarction even during the first few days of the first AMI.
Diagnosis of AMI is now based on an abnormal electrocardiogram (ECG), clinical symptoms and history, and elevated cardiac enzyme levels. Currently, CKMB is often used as the "definitive" serum marker for AMI.
However, often the ECG and clinical presentation give inconclusive or conflicting predictions of cardiac trauma. CK-MB testing has some limitations in contributing to final diagnosis. Skeletal muscle damage and strenuous exercise can artificially elevate CK-MB levels and confuse the clinical picture. In addition, CK-MB does not become diagnostically elevated until 4-6 hours after AMI. In addition, CK-MB levels become non-diagnostic 48-72 hours after AMI.
CK-MB has been prepared in a control solution to monitor diagnostic measurements of this analyte, however CK-MB is an enzyme which has limited stability in human serum and common buffered aqueous solutions. U.S. Pat. No. 4,994,375 discloses a stable reconstituted aqueous based control. Currently there are immunoassay kits, such as the DADE® STATUS® CK-MB Fluorometric Enzyme Immunoassay Kit available on the market for the determination of CK-MB levels. Many of these kits include calibrators. Control solutions containing CK-MB, such as the DADE® CK-MB/Myoglobin Immunoassay Control, are also commercially available.
Myoglobin is a marker present in both skeletal and cardiac muscle. Myoglobin levels are elevated within 2 hours of AMI. The serum level peaks in 6-8 hours but returns to non-diagnostic levels after 24-36 hours. However, serum myoglobin levels are also increased after skeletal muscle injury. There are a few immunoassay kits, such as the DADE® STRATUS® Myoglobin Fluorometric Enzyme Immunoassay Kit for the determination of myoglobin levels, that are commercially available. Myoglobin containing control solutions have been prepared and are commercially available from such sources as DADE® CK-MB/Myoglobin Immunoassay Control.
Troponin is a protein complex having a molecular weight of about 85 kD that performs the regulatory function of the contractile mechanism of the muscle tissue. The amino acid sequences of subunits which comprise the troponin complex has been determined. See, for instance, Vallins W. J. et al., Molecular cloning of human cardiac troponin I using polymerase chain reaction, FEBS LETTERS :Vol. 270, number 1, 2 Sep. 1990. Troponin is composed of three subunits of similar molecular weight, which, in the presence of calcium, cooperate to control either the contraction or relaxation of the muscle. The three subunits are designated troponin T, C, and I. Both the T and I molecules contained in heart muscle have amino acid sequences which are cardiac specific. Thus, both troponin T and troponin I have potential for superior specificity in testing for damage of myocardial origin. Damage to cardiac tissue causes these contractile proteins to be released into circulation fairly rapidly after injury providing the potential for sensitivity as well. Troponin is diagnostic 4-6 hours after AMI and remains elevated for 4-14 days.
Proteins of the contractile apparatus such as troponin are part of an insoluble protein complex. Thus, when purified troponin is placed in serum it is difficult to solubilize. In addition, purified preparations of troponin tend to be very labile and apparent changes in its conformation and/or adhesion to container surfaces tend to complicate quantification of the molecule. Thus, it is very difficult to design an aqueous solution which stabilizes troponin. Currently commercially available calibrators and controls used for diagnostic assays for troponin have very limited stability in liquid form.
Thus a need exists for aqueous solutions useful for solubilizing and stabilizing troponin. Such solutions can function as a diagnostic control or calibrator matrix for troponin and other cardiac markers or other proteins that are difficult to solubilize and/or stabilize. In addition, the matrix is useful for storing the protein(s).
Several criteria need to be met when formulating a calibrator or control base for troponin or other proteins that have stability or solubility issues similar to troponin. Stability issues are of primary concern. Liquid products are preferred for reproducibility and ease of use and should be stable. However if the product is lyophilized, it should be stable after reconstitution. Previous troponin calibrators are based on human serum derived products and contribute very little to the stability of the composition. For instance, the published "dating" of human serum based lyophilized troponin T calibrators and controls of the Boehringer Mannheim ELISA-TEST® Troponin T after reconstitution is only 6 hours at 2 to 8 C and 3 months when aliquoted and stored at -20 C. A matrix which increases the stability of the product is highly desirable.
Moreover, use of normal or processed human serum presents health issues to both clinicians and manufacturers. Thus, a matrix which lowers health risks is also highly desirable.
The calibrators in a synthetic matrix must mimic the shape of a response curve using normal human serum. This is important to ensure that results read off a standard curve generated with the matrix are accurate when comparing the results to the actual biological milieu.
In a diagnostic assay, non-specific binding of the analyte to the test surface (e.g. solid support such as test tubes, paper, slides etc.) must be minimized in order to keep calibration accurate and eliminate any risks of "discrepant" results. Thus, the non-specific binding of the analyte in a matrix must be minimized and must be similar to the non-specific binding of samples. It is also important that during storage, the protein or protein fragment does not appreciably bind to the storage container.
There are instances when an analyte analogue may be more desirable than the actual analyte. If an analyte analogue is used instead of the analyte, the binding of the analogue must mimic the binding of the analyte. Particular care must be used when selecting analogues for proteins because the immunobinding of the analogue must mimic that of the protein. Thus, any conformational dependence of the protein for the binding site must be maintained in the analogue. In addition, stability of the analogue should be the same or greater than that of the analyte. Again, the stability of the protein analyte may be related to its conformation. Finally, if an analogue is substituted for an analyte, it is desirable that the analogue be more readily available than the analyte.
SUMMARY OF THE INVENTION
This invention provides a stabilized clinical laboratory non-human serum derived control and/or calibrator matrix to be used in performing calibration curves for diagnostic assays and for monitoring the precision and accuracy of diagnostic assays for certain unstable and/or less soluble proteins such as cardiac markers. In particular, the stabilized matrix is useful for solubilizing and/or stabilizing troponin I, troponin T, CK-MB, myoglobin, myosin and fragments of these proteins or analytes.
The matrix uses a novel mixture of constituents to impart a stability to the analyte that is at least equivalent and preferably better than the stability of the analyte in normal human serum. In particular, an aqueous based mixture of a buffer, albumin, gelatin, chelating agent, reducing agent and salts, all at a slightly acidic to mildly alkaline pH is used to stabilize and solubilize the analyte or analyte analogue.
Also disclosed are methods to prepare the matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a comparison of the stability at 2-8 C of recombinant full length troponin I in various matrices.
FIG. 2 shows a comparison of the stability at 2-8 C of a recombinantly produced 80 amino acid peptide in various matrices.
FIG. 3 shows a comparison of the stability at 2-8 C of a 10 ng/mL calibrator of a synthetic peptide of troponin I in various matrices.
FIG. 4 shows a comparison of the stability at 2-8 C of a 50 ng/mL calibrator of a synthetic peptide of troponin I in various matrices.
FIG. 5 shows a comparison of the stability at 37 C of a synthetic peptide of troponin I in various matrices.
FIG. 6 shows a comparison of the stability at 37 C of a synthetic peptide of troponin I in various matrices where all of the matrices include a protease inhibitor.
FIG. 7 shows a calibration curve of different levels of a synthetic peptide of troponin I in a matrix of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The stabilized clinical laboratory non-human serum derived control and/or calibrator matrix for cardiac markers and other unstable proteins comprises an aqueous solution of a buffer, a stabilizing protein such as albumin, ovalbumin, casein and the like, a chelating agent, a reducing agent and a salt, all at a slightly acidic to mildly alkaline pH.
The matrix can contain a blocking agent such as gelatin, detergents and protease inhibitors. A preservative may be added to prevent microbial growth. An analyte or analyte analogue such as cardiac markers or other unstable or relatively insoluble proteins or fragments thereof are also added. If the calibrator or control will be lyophilized or frozen, sugars or other bulking agents are added.
The preferred buffers include buffers such as TRIS buffers and phosphate buffers. Other buffers include: 3-(N-Morpholino) propane sulfonic acid (MOPS), N-Tris-hydroxymethyl methyl-2-aminoethane sulfonic acid (TES), 3-[N-bis (hydroxyethyl)-amino]-2-hydroxypropane sulfonic acid (DIPSO), Piperazine-N, N'Bis(2)-hydroxypropane sulfonic acid (HEPPSO), Tris-(hydroxymethyl) aminoethane, N-2-Hydroxyehtylpiperazine-N'-2-aminoethane sulfonic acid (HEPES), 3-[N-(Tris-hydroxymethyl) methylamino] -2-hydroxypropane sulfonic acid (TAPSO), and (2 p[2-Amino-2-oxoethyl) - amino] ethanesulfonic acid (ACES). The most preferred buffer is a phosphate such as sodium phosphate.
The concentration of the buffer may be from about 10 mM to 200 mM. Preferably the concentration is about 25 mM to 100 mM. Most preferably the concentration is about 50 mM.
The stabilizing protein may be albumin, ovalbumin, casein or the like. The stabilizing protein, as with the other ingredients, should be essentially free of contaminants that interfere with the stability of the analyte in the matrix. Substances that may destabilize or destroy protein structure such as proteases are examples of such contaminants. Albumin is a preferred stabilizing protein. The source of the albumin is not critical. The albumin may be native or recombinant in origin. The most available source of native albumin is of bovine origin. It is most preferred that the albumin be essentially protease-free if the protein analyte or analogue is susceptible to protease degradation. Alternatively, protease inhibitors can be added. The preferred concentration of albumin is from 5-20%, 8-12% and most preferably at about 10%.
Although not wishing to be bound by any particular theory, it is believed that the protein stabilizer functions to provide a protective effect to the analyte or analyte analogue.
A blocking agent (i.e. an agent to minimize the non specific binding of the analyte or analyte analogue to surfaces) such as gelatin, casein, ovalbumin and the like may be added. Gelatin is the preferred blocking agent. The gelatin, if of bovine origin, is added at a concentration of about 0.01 to 0.15%, most preferably 0.1%. If the gelatin is of a different origin (e.g. fish) the concentration is adjusted appropriately.
A chelating agent is also added. The preferred chelating agents are ethylenebis (oxyethylene nitrilio)tetraacetic acid (EGTA) and ethylene diamine tetracetic acid (EDTA), sodium citrate, or oxalate salts such as sodium, potassium, ammonnium or lithium oxalte. The most preferred chelating agent is EDTA. The concentration of chelating agents may be from 1 mM to 15 mM and most preferably is from 5 to 10 mM.
The preferred reducing agent is N-acetyl-cysteine (NAC). Examples of other reducing agents which may be used include 2-aminoethanethiol, 2-mercaptoethanol, 2-mercaptoethylanine and dithiothreitol.
The concentration of reducing agent may be from about 0 to 5 mM, preferably the reducing agent is about 2 mM to 3.5 mM, and most preferably about 2.6 mM.
The pH may be from about 5.0 to 8.0. Slightly acidic pH values lower the non-specific binding of the troponin. The preferred range of pH is about 5 to 7.5 and most preferably about 7.0.
The preferred salt is sodium chloride. Many other salts may be substituted. Examples of other salts include potassium salts, ammonium salts, and lithium salts.
If a protease inhibitor is added, aprotinin and "Protease Inhibitor" (Sigma) are effective and may be used at the manufacturer's recommended concentration. Examples of other protease inhibitors include (2S, 3R)-3-Amino-2-hydroxy-5-methylhexanoyl]-Val-Val-Asp (Amastatin-Sigma), [2S,3R]-3-Amino-2-hydroxy-4-[4-nitrophenyl]-butanoyl-L-leucine, Antipain, [2S,3R]-3-Amino-2-hydroxy-5-methylhexanoyl]-Val-Val-Asp (Epiamastatin-Sigma), ([2R,3R]-3-Amino-2-hydroxy-4-phenylbutanoyl)-L-leucine (Epibestatin-Sigma), Foroxymithine, Acetyl-Leu-Leu-Arg-al (Leupeptin-Sigma), 4-Amino-3-hydroxy-6-methyl-heptanoic acid, 4-Amino-3-hydroxy-6-methylheptanoic acid, N-(α-Rhamnopyranosyloxy-hydroxyphosphinyl)-Leu-Trp and phenyl methane sulfonyl fluoride (PMSF).
The preferred detergents, if added, are SDS and Triton X-100. Other detergents include Tween-20, Brij, Sorbitin, Tergital and Nonidet. The concentration of detergents may be from 0.05% to 0.3%. The preferred range is from about 0.05% and 0.2%. The most preferred concentration is 0.1%.
The preservative may be added to prevent microbial and fungal growth. The preservatives may be clotrimazole of at least 0.03%, chloramphenicol of at least 0.017%, or sodium azide of at least 0.05%. Other preservatives include gentamicin, mycostatin, thimerasol and Kathon at an effective concentration.
To prepare the matrix, plastics such as polypropylene should be used. This minimizes loss of proteins to glass due to non specific binding to glass. Alternatively, glass based labware can be utilized but should be siliconized prior to use.
If the calibrator or control matrix is to be lyophilized or frozen, bulking agents are added. The preferred bulking agents are trehalose at 3 to 10% and sucrose at about 100 mM. The most preferred concentration of trehalose is about 5-10%. Other bulking agents include glucose, sucrose, galactose, manose, maltose, lactose, isomaltose, cellobiose, mannobiose, melbiose, maltotriose, nystose, maltotetraose, maltopentaose, maltohexaose, and maltoheptaose.
One liter of the matrix may be prepared by dissolving about 30 grams of BSA, about one gram of gelatin, about 15 grams of sodium chloride, 3 grams of EDTA, about 50 grams of trehalose, a preservative and a clinically appropriate level of the analyte or analyte analogue in 700 ml of 0.50 mM sodium phosphate buffer. After all ingredients are dissolved the pH is adjusted to 7.0 and then a sufficient volume of a buffer, such as sodium phosphate, is added to bring the volume to 1.0 L. The solution is sterile filled in suitable containers and lyophilized. The lyophilized analyte containing matrix is reconstituted by adding one liter of a diluent containing 65 grams of BSA, 25 grams of NaCl, protease inhibitor, and about 0.4 grams of NAC.
Alternatively, one liter of the matrix may be prepared by dissolving about 100 grams of BSA, about one gram of gelatin, about 40 grams of sodium chloride, 3 grams of EDTA, a preservative, and 0.4 grams of NAC and a clinically appropriate level of the analyte or analyte analogue in 700 ml of 0.50 m sodium phosphate. After all ingredients are dissolved the pH is adjusted to 7.0 and then a sufficient volume of a buffer, such as sodium phosphate is added to bring the volume to 1.0 L. The liquid may be aliquoted and stored refrigerated or frozen. If the liquid is to be frozen, bulking agents are also added.
Surprisingly for the troponin I analyte, troponin I fragments also have increased stability. This is surprising because the stability of the troponin I fragments was found to be less than that of the full length troponin I when the matrix is normal human serum. In addition, certain troponin I fragments had similar binding to the anti-troponin antibody used in the assay when compared with the full length troponin I molecule.
Thus, the present invention has many advantages over the prior art. The matrix is non-human serum derived which prevents the user (and manufacturing personnel) from exposure to many of the diseases which can be spread by contact with human blood products. The matrix is also able to keep the analyte stable in liquid form for an extended period of time. Current formulations can also be lyophilized or frozen and can be reliably reconstituted or thawed for up to at least nine months shelf storage with very little variation in calibration. After reconstitution or thawing, the analyte is stable for up to three weeks at 2-8C. Spiking of the analyte into the matrix yields a calibration curve which closely parallels a human serum curve. Non-specific binding levels in the "synthetic" matrix also closely parallel the levels seen in normal human serum. Moreover, fragments such as recombinantly or synthetically produced peptide fragments of proteins can be utilized instead of full length proteins. Indeed these fragments are preferred because of their stability in the matrix coupled with the availability and reproducibility of the recombinantly or synthetically produced fragments. The analyte analogue (e.g. the fragment) should have binding characteristics similar to that of the full length marker. Methods to determine and map epitope sites are known to those skilled in the art as is the art of producing antibodies against a specific antigen.
It is to be understood that the matrix of the present invention can be used for many analytes but it is particularly useful when the analyte is an unstable and/or relatively insoluble protein such as the cardiac markers, in particular troponin and CK-MB.
EXAMPLE 1
Preparation of a Calibrator/Control Matrix
To about seven hundred milliliters of purified water was added with stirring about three grams of EDTA (stirred until dissolved), then about 40.0 grams of sodium chloride, about 6.9 grams of sodium phosphate, monobasic, about 0.424 mgs of NAC, about 50 grams of trehalose, about 3.3 milliliters of a stock solution of chloramphenicol to provide a final concentration of 165 mg/mL, about 0.75 milliliters of a stock solution of clortrimazole to provide a final concentration of 3 ppms, about 10 milliliters of a 1% aqueous solution of gelatin, then stirring slowly, about 95 grams of protease free bovine serum albumin until dissolved), and 2 milliliters of a 25% solution of sodium azide. The pH was adjusted to 7.3 and the total volume was adjusted to 1 liter with purified water. The final matrix may be sterile filtered.
EXAMPLE 2
Preparation of a Lyophilized Calibrator/Control Matrix
To about seven hundred milliliters of purified water is added about three grams of EDTA, about 15 grams of sodium chloride, about 7 grams of sodium phosphate, monobasic, about 50 grams of trehalose, about 3.3 milliliters of a stock solution of chloramphenicol to provide a final concentration of 165 mg/mL, about 0.75 milliliters of a stock solution of clortrimazole to provide a final concentration of 3 ppms, about 10 milliliters of a 1% aqueous solution of gelatin, and about 30 grams of bovine serum albumin. The pH is adjusted to 5.5 and the total volume is adjusted to 1 liter with purified water. The final matrix is sterile filtered and lyophilized. A reconstitution diluent of one liter is prepared by combining in aqueous solution about 65 grams of albumin, 25 grams of sodium chloride and 0.4 grams of NAC, protease inhibitor and about 2 milliliters of a 25% solution of sodium azide.
EXAMPLE 3
Preparation of a Calibrator/Control Matrix
To about seven hundred milliliters of purified water is added about five grams of EDTA, about 50 grams of sodium chloride, about 7 grams of sodium phosphate, monobasic, about 0.4 mgs of NAC, about 3.3 milliliters of a stock solution of chloramphenicol to provide a final concentration of 165 mg/mL, about 0.75 milliliters of a stock solution of clortrimazole to provide a final concentration of 3 ppms, about 10 milliliters of a I% aqueous solution of gelatin, and about 95 grams of protease free bovine serum albumin. The pH is adjusted to 6.5 and the total volume is adjusted to 1 liter with purified water. The final matrix may be sterile filtered.
EXAMPLE 4
Preparation of Calibrators using a recombinant protein
A stock solution of human recombinant troponin I was prepared in polypropylene labware by adding a sufficient amount of recombinant troponin I so that calibrators or controls can be made that have concentrations ranging from about 0 to 100 ng/mL of troponin I.
In one experiment solutions of troponin I were prepared by adding a sufficient amount of an unpurified solution of recombinant troponin I at 100 ug/mL to the following matrices:
Normal human serum, plasma, and a matrix similar to that described in Example 1. For each matrix the final volume was 15 milliliters of a 100 ng/mL solution of recombinant troponin I. The recombinant troponin I had the following sequence:
Met Ala Asp Gly Ser Ser Asp Ala Ala Arg Glu Pro Arg Pro Ala Pro Ala Pro Ile Arg Arg Arg Ser Ser Asn Tyr Arg Ala Tyr Ala Thr Glu Pro His Ala Lys Lys Lys Ser Lys Ile Ser Ala Ser Arg Lys Leu Gln Leu Lys Thr Leu Leu Leu Gln Ile Ala Lys Gln Glu Leu Glu Arg Glu Ala Glu Glu Arg Arg Gly Glu Lys Gly Arg Ala Leu Ser Thr Arg Cys Gln Pro Leu Glu Leu Ala Gly Leu Gly Phe Ala Glu Leu Gln Asp Leu Cys Arg Gln Leu His Ala Arg Val Asp Lys Val Asp Glu Glu Arg Tyr Asp Ile Glu Ala Lys Val Thr Lys Asn Ile Thr Glu Ile Ala Asp Leu Thr Gln Lys Ile Phe Asp Leu Arg Gly Lys Phe Lys Arg Pro Thr Leu Arg Arg Val Arg Ile Ser Ala Asp Ala Met Met Gln Ala Leu Leu Gly Ala Arg Ala Lys Glu Ser Leu Asp Leu Arg Ala His Leu Lys Gln Val Lys Lys Glu Asp Thr Glu Lys Glu Asn Arg Glu Val Gly Asp Trp Arg Lys Asn Ile Asp Ala Leu Ser Gly Met Glu Gly Arg Lys Lys Lys Phe Glu Ser
and included a 6 His carboxy terminus tail and a seven amino acid sequence from the phage T7 Gene 10 leader sequence at the amino terminus. See, also Vallins W. J. et al., Molecular cloning of human cardiac troponin I using polymerase chain reaction, FEBS LETTERS :Vol. 270, number 1, 2 Sep. 1990.
Aliquots of each of the three troponin I solutions were stored at 2-8 C and evaluated for stability. On each day of the evaluation an aliquot of each troponin I solution was analyzed on a Stratus II Fluorometric Analyzer. The Stratus II Fluorometric Analyzer is sold by Dade International Inc. For principles of operation of the analyzer and immunoassay see for instance U.S. Pat. No. 4,517,288 incorporated herein by reference and Giegle et al. Clinical Chemistry 28:1894-1898 (1982). The analyzer measures the rate of change of a fluorescent signal. Generally, an antibody to an analyte, such as troponin I, is pre-immobilized on a solid phase of glass fiber filter paper. For troponin I, an aliquot of each troponin I solution is applied to the antibody and immunologically binds to the antibody to form a reaction zone. Next, a conjugate of alkaline phosphatase-anti-troponin I antibody is added to the reaction zone. The conjugate binds to the troponin I. A substrate wash solution containing 4 methyl umbelliferyl phosphate is applied to the reaction zone. A front surface fluorometer measures the rate of change of fluorescence in rate units designated as millivolts per minute (mvm).
The results of the evaluation can be seen in FIG. 1. As can be seen from FIG. 1, the matrix of the present invention provided more stability to the troponin-I analyte than normal human serum or plasma.
EXAMPLE 5
Preparation of Calibrators using a recombinantly produced peptide
A stock solution of human recombinant troponin I peptide is prepared in polypropylene labware by adding a sufficient amount of a recombinant troponin I peptide so that calibrators or controls can be made that have concentrations ranging from about 0 to 100 ng/mL of troponin I.
In one experiment solutions of troponin I were prepared by adding a sufficient amount of a recombinant 80 amino acid peptide of recombinant troponin I having the sequence
Ala Asp Gly Ser Ser Asp Ala Ala Arg Glu Pro Arg Pro Ala Pro Ala Pro Ile Arg Arg Arg Ser Ser Asn Tyr Arg Ala Tyr Ala Thr Glu Pro His Ala Lys Lys Lys Ser Lys Ile Ser Ala Ser Arg Lys Leu Gln Leu Lys Thr Leu Leu Leu Gln Ile Ala Lys Gln Glu Leu Glu Arg Glu Ala Glu Glu Arg Arg Gly Glu Lys Gly Arg Ala Leu Ser Thr Arg Cys Gln
also having a six histidine tail at the carboxy terminus and seven amino acids from the phage T7 Gene 10 leader sequence at the amino terminus (see, also Vallins W. J. et al., Molecular cloning of human cardiac troponin I using polymerase chain reaction, FEBS LETTERS :Vol. 270, number 1, 2 Sep. 1990) at 7500 ng/mL to the following matrices:
Normal human serum, processed human plasma, plasma, and a matrix similar to that described in Example 1 to provide a 100 ng/mL solution of recombinant troponin I peptide in each matrix.
Aliquots of each of the four troponin I solutions were stored at 2-8 C and evaluated for stability. On each day of the evaluation an aliquot of each troponin I solution was analyzed on a Stratus II Fluorometric Analyzer. The Stratus II Fluorometric Analyzer is sold by Dade International Inc. For principles of operation of the analyzer and immunoassay see for instance U.S. Pat. No. 4,517,288 incorporated herein by reference and Giegle et al. Clinical Chemistry 28:1894-1898 (1982). The analyzer measures the rate of change of a fluorescent signal. Generally, an antibody to an analyte, such as troponin I, is pre-immobilized on a solid phase of glass fiber filter paper. For troponin I, an aliquot of each troponin I solution is applied to the antibody and immunologically binds to the antibody to form a reaction zone. Next, a conjugate of alkaline phosphatase-anti-troponin I antibody is added to the reaction zone. The conjugate binds to the troponin I. A substrate wash solution containing 4 methyl umbelliferyl phosphate is applied to the reaction zone. A front surface fluorometer measures the rate of change of fluorescence in rate units designated as millivolts per minute (mvm).
The results of the evaluation can be seen in FIG. 2. As can be seen from FIG. 2, the matrix of the present invention provided more stability to the troponin-I analyte than normal human serum, processed human plasma (PHP) or plasma.
EXAMPLE 6
Preparation of Calibrators using a synthetic peptide
A stock solution of a synthetic peptide of troponin I is prepared in polypropylene labware by adding a sufficient amount of the peptide so that calibrators or controls can be made that have concentrations ranging from about 0 to 50 ng/mL of troponin I.
In one experiment solutions of troponin I were prepared by adding a sufficient amount of a synthetic peptide of troponin I having the sequence
Arg Ala Tyr Ala Thr Glu Pro His Ala Lys Lys Lys Ser Lys Ile Ser Ala Ser Arg Lys Leu Gln Leu Lys Thr Leu Leu Leu Gln Ile Ala Lys Gln Glu Leu
at a stock concentration (in purified water) of 1.4 mg/mL to the following matrices:
Normal human serum, plasma, processed human plasma, a synthetic matrix at pH 7.6 containing 100 mM Tris, 150 mM NaCl, 0.1% Gelatin, 2% BSA, 0.1% Sodium Azide, and 0.1% Zonyl fluorosurfactant (DXMC)and a matrix similar to that described in Example 1 to provide 50 ng/mL solution of troponin I in each matrix and a 10 ng/mL solution of troponin I.
Aliquots of each of the four troponin I solutions were stored at 2-8 C and evaluated for stability. On each day of the evaluation an aliquot of each troponin I solution was analyzed on a Stratus II Fluorometric Analyzer. The Stratus II Fluorometric Analyzer is sold by Dade International Inc. For principles of operation of the analyzer and immunoassay see for instance U.S. Pat. No. 4,517,288 incorporated herein by reference and Giegle et al. Clinical Chemistry 28:1894-1898 (1982). The analyzer measures the rate of change of a fluorescent signal. Generally, an antibody to an analyte, such as troponin I, is pre-immobilized on a solid phase of glass fiber filter paper. For troponin I, an aliquot of each troponin I solution is applied to the antibody and immunologically binds to the antibody to form a reaction zone. Next, a conjugate of alkaline phosphatase-anti-troponin I antibody is added to the reaction zone. The conjugate binds to the troponin I. A substrate wash solution containing 4 methyl umbelliferyl phosphate is applied to the reaction zone. A front surface fluorometer measures the rate of change of fluorescence.
The results of the evaluation can be seen in FIGS. 3 and 4. As can be seen from FIGS. 3 and 4, the matrix of the present invention provided more stability to the troponin-I analyte analogue than normal human serum, processed human plasma (PHP), the synthetic base DXMC, or plasma.
EXAMPLE 7
Preparation of Calibrators using a synthetic peptide
A stock solution of a synthetic peptide of troponin I is prepared in polypropylene labware by adding a sufficient amount of the peptide so that calibrators or controls can be made that have concentrations ranging from about 0 to 100 ng/mL of troponin I.
In one experiment solutions of 40 ug/mL troponin I were prepared by adding a sufficient amount of a synthetic peptide of troponin I having the sequence
Arg Ala Tyr Ala Thr Glu Pro His Ala Lys Lys Lys Ser Lys Ile Ser Ala Ser Arg Lys Leu Gln Leu Lys Thr Leu Leu Leu Gln Ile Ala Lys Gln Glu Leu
to the following matrices:
Normal human serum, plasma, and a matrix similar to that described in Example 1 (except that the pH of the synthetic matrix was adjusted to 5.5) to provide 3.0 milliliters of a 100 ng/mL solution of troponin I in each matrix. In addition, EDTA was added to each matrix at about 3.5 mg/mL.
A second set of solutions was prepared as above, except that the solutions also contained a protease inhibitor cocktail of PEPSTATIN at 680 ng/mL and aminoethylbenzenesulfonyl fluoride at 208 ug/mL.
Aliquots of each of the six troponin I solution were stored at 37 C and evaluated for stability. On each day of the evaluation an aliquot of each troponin I solution was analyzed on a Stratus II Fluorometric Analyzer. The Stratus II Fluorometric Analyzer is sold by Dade International Inc. For principles of operation of the analyzer and immunoassay see for instance U.S. Pat. No. 4,517,288 incorporated herein by reference and Giegle et al. Clinical Chemistry 28:1894-1898 (1982). The analyzer measures the rate of change of a fluorescent signal. Generally, an antibody to an analyte, such as troponin I, is pre-immobilized on a solid phase of glass fiber filter paper. For troponin I, an aliquot of each troponin I solution is applied to the antibody and immunologically binds to the antibody to form a reaction zone. Next, a conjugate of alkaline phosphatase-anti-troponin I antibody is added to the reaction zone. The conjugate binds to the troponin I. A substrate wash solution containing 4 methyl umbelliferyl phosphate is applied to the reaction zone. A front surface fluorometer measures the rate of change of fluorescence in rate units designated as millivolts per minute (mvm).
The results of the evaluation can be seen corresponding to FIGS. 5 and 6. As can be seen from FIGS. 5 and 6, the matrix of the present invention provided more stability to the troponin-I analyte analogue than normal human serum, or plasma with or without the protease inhibitors.
EXAMPLE 8
Performing an Immunoassay using Troponin I Calibrators and Controls
A stock solution of a synthetic peptide of troponin I is prepared in polypropylene labware by adding a sufficient amount of the peptide so that calibrators or controls can be made that have concentrations ranging from about 0 to 50 ng/mL of troponin I.
In one experiment solutions of troponin I were prepared by adding a sufficient amount of a synthetic peptide of troponin I having the sequence
Arg Ala Tyr Ala Thr Glu Pro His Ala Lys Lys Lys Ser Lys Ile Ser Ala Ser Arg Lys Leu Gln Leu Lys Thr Leu Leu Leu Gln Ile Ala Lys Gln Glu Leu
at a stock concentration of 1.4 mg/mL to a matrix similar to that described in Example 1 to provide calibrator solutions of troponin I having the following concentrations: 0 ng/mL, 2 ng/mL, 8 ng/mL, 15 ng/mL, 25 ng/mL and 50 ng/mL. Controls were prepared in a similar fashion to provide control solutions at about 4 ng/mL , 20 ng/mL and 35 ng/mL.
Aliquots of each of the troponin I solutions were stored frozen. Frozen solutions were thawed and a calibration curve was generated. The controls prepared as discussed above and controls prepared from normal human serum were also evaluated. The range for the normal human serum controls was 2.1-2.9 ng/mL for the low control and 15.9-21.5 for the high control. Duplicate samples of each troponin I solution was analyzed on a Stratus II Fluorometric Analyzer and a calibration curve was generated. The Stratus II Fluorometric Analyzer is sold by Dade International Inc. For principles of operation of the analyzer and immunoassay see for instance U.S. Pat. No. 4,517,288 incorporated herein by reference and Giegle et al. Clinical Chemistry 28:1894-1898 (1982). The analyzer measures the rate of change of a fluorescent signal. An antibody to an analyte, such as troponin I, is pre-immobilized on a solid phase of glass fiber filter paper. An aliquot of each troponin I solution is applied to the antibody and immunologically binds to the antibody to form a reaction zone. Next, a conjugate of alkaline phosphatase-anti-troponin I antibody is added to the reaction zone. The conjugate binds to the troponin I. A substrate wash solution containing 4 methyl umbelliferyl phosphate is applied to the reaction zone. A front surface fluorometer measures the rate of change of fluorescence in rate units designated as millivolts per minute (mvm).
The results of the calibration in millivolts per minute (mvm) can be seen in Table 1 and the calibration curve is presented graphically in FIG. 6.
TABLE 1______________________________________Calibrator Rate 1 Rate 2 Mean Level (mvm) (mvm) (mvm)______________________________________0 171.5 180.4 176.0 2 463.7 464.5 464.1 8 1287.5 1208.5 1248.0 15 2487.6 2481.9 2484.8 25 3926.6 3826.6 3876.6 50 7668.0 6767.0 7217.5______________________________________
Control recoveries are presented in Table 2.
TABLE 2______________________________________ Rep. 1 Rep. 2 Rep. 3 Rep. 4 Mean Control (ng/mL) (ng/mL) (ng/mL) (ng/mL) (ng/mL)______________________________________Syn. Low 3.7 3.6 3.7 Syn. Mid 17.1 16.3 16.7 Syn. Hi 32.6 32.8 32.7 Serum Lo 2.6 2.5 2.5 2.3 2.5 Serum Hi 18.2 18.7 19.7 18.0 18.7______________________________________
EXAMPLE 9
Preparing CK-MB Calibrators/Controls
A stock solution of CK-MB is prepared by adding a sufficient amount of the CK-MB so that calibrators or controls can be made that have concentrations ranging from about 0 to 125 ng/mL of CK-MB.
Solutions of CK-MB are prepared by adding a sufficient amount of CK-MB to a matrix similar to that described in Example 1 to provide calibrator solutions of CK-MB having the following concentrations: 0, 4, 10, 25, 60 and 125 ng/mL. Controls are prepared in a similar fashion
EXAMPLE 10
Preparing Troponin T Calibrators/Controls
A stock solution of Troponin T is prepared by adding a sufficient amount of the Troponin T so that calibrators or controls can be made that have concentrations ranging from about 0 to 12 ng/mL of Troponin T.
Solutions of Troponin T are prepared by adding a sufficient amount of Troponin T to a matrix similar to that described in Example 1 to provide calibrator solutions of Troponin T having the following concentrations: 0, 1, 2, 4, 8, and 12 ng/mL. Controls are prepared in a similar fashion
EXAMPLE 11
Stability of Calibrators at 4C
A study was conducted to determine the stability of calibrators prepared similarly to the calibrators prepared in Example 6. Immunoassay kits, which included calibrators, were prepared and stored at about 4 C and evaluated on a Stratus II Fluorometric Analyzer. On each day of the evaluation calibration curves were generated using unopened vials of calibrators and controls and a patient pool to determine if the controls and patient pool (both stored at -70 C and freshly thawed prior to use) recovered within the expected ranges. The ranges of the controls and patient pool had been previously established by obtaining at least 80 replicates of each control level and patient pool. The control limits were set at ±2 standard deviations or 15% of the mean, whichever was larger. All of the assay components, thus the calibrators, were determined to be acceptable if the duplicates of each control and patient pool were within 12% of and if the mean of the duplicates fell within the calculated range. The assay kit, thus the calibrators, were found to be acceptable for at least 60 days. A second study conducted similarly confirmed the results.
EXAMPLE 12
Stability of Calibrators at 25C
Two studies were conducted similarly to that described in Example 11, except that the kit reagents were stored at 25C instead of 4C. The kits, thus the calibrators, were found to be stable for at least about 7-14 days.
EXAMPLE 13
Stability of Calibrators at 2 to 8C/-70 C
A study was conducted similarly to that described in Example 11, except that the calibrators at 2 ng/mL and 25 ng/mL were also stored at -70C. The recovery of the frozen calibrators was determined and compared to calibrators stored at 4C. A ratio of the 2-8 C/-70 C was determined. The calibrators at -70 C, were found to be stable for at least 60 days. A second study conducted similarly confirmed the results.
In another study, the recovery of a patient pool (stored and used as described above in Example 11 with an established recovery range also as described above in Example 11) against a calibration curve generated from calibrators stored at -70 C was determined. The calibrators were found to be stable for at least 100 days.
__________________________________________________________________________# SEQUENCE LISTING - - - - (1) GENERAL INFORMATION: - - (iii) NUMBER OF SEQUENCES: 3 - - - - (2) INFORMATION FOR SEQ ID NO:1: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 210 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: peptide - - (x) PUBLICATION INFORMATION: (A) AUTHORS: VALLINS, W - #ILLIAM J. BRAND, NI - #GEL J. DABHADE, - #NINA BUTLER-BROWN - #E, GILLIAN YACOUB, M - #AGDI H. BARTON, P - #AUL J.R. (B) TITLE: MOLECULAR CL - #ONING OF HUMAN CARDIAC TROPONIN I USING POL - #YMERASE CHAIN RECTION (C) JOURNAL: FEBS Lett. (D) VOLUME: 270 (E) ISSUE: 1,2 (F) PAGES: 57-61 (G) DATE: SEPTEMBER-1990 (K) RELEVANT RESIDUES I - #N SEQ ID NO:1: FROM 1 TO 212 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: - - Met Ala Asp Gly Ser Ser Asp Ala Ala Arg Gl - #u Pro Arg Pro Ala Pro 1 5 - # 10 - # 15 - - Ala Pro Ile Arg Arg Arg Ser Ser Asn Tyr Ar - #g Ala Tyr Ala Thr Glu 20 - # 25 - # 30 - - Pro His Ala Lys Lys Lys Ser Lys Ile Ser Al - #a Ser Arg Lys Leu Gln 35 - # 40 - # 45 - - Leu Lys Thr Leu Leu Leu Gln Ile Ala Lys Gl - #n Glu Leu Glu Arg Glu50 - # 55 - # 60 - - Ala Glu Glu Arg Arg Gly Glu Lys Gly Arg Al - #a Leu Ser Thr Arg Cys 65 - #70 - #75 - #80 - - Gln Pro Leu Glu Leu Ala Gly Leu Gly Phe Al - #a Glu Leu Gln Asp Leu 85 - # 90 - # 95 - - Cys Arg Gln Leu His Ala Arg Val Asp Lys Va - #l Asp Glu Glu Arg Tyr 100 - # 105 - # 110 - - Asp Ile Glu Ala Lys Val Thr Lys Asn Ile Th - #r Glu Ile Ala Asp Leu 115 - # 120 - # 125 - - Thr Gln Lys Ile Phe Asp Leu Arg Gly Lys Ph - #e Lys Arg Pro Thr Leu130 - # 135 - # 140 - - Arg Arg Val Arg Ile Ser Ala Asp Ala Met Me - #t Gln Ala Leu Leu Gly 145 1 - #50 1 - #55 1 -#60 - - Ala Arg Ala Lys Glu Ser Leu Asp Leu Arg Al - #a His Leu Lys GlnVal 165 - # 170 - # 175 - - Lys Lys Glu Asp Thr Glu Lys Glu Asn Arg Gl - #u Val Gly Asp Trp Arg 180 - # 185 - # 190 - - Lys Asn Ile Asp Ala Leu Ser Gly Met Glu Gl - #y Arg Lys Lys Lys Phe 195 - # 200 - # 205 - - Glu Ser210 - - - - (2) INFORMATION FOR SEQ ID NO:2: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 80 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: peptide - - (x) PUBLICATION INFORMATION: (A) AUTHORS: VALLINS, W - #ILLIAM J. BRAND, NI - #GEL J. DABHADE, - #NINA BUTLER-BROWN - #E, GILLIAN YACOUB, M - #AGDI H. BARTON, P - #AUL J.R. (B) TITLE: MOLECULAR CL - #ONING OF HUMAN CARDIAC TROPONIN I USING POL - #YMERASE CHAIN RECTION (C) JOURNAL: FEBS Lett. (D) VOLUME: 270 (E) ISSUE: 1,2 (F) PAGES: 57-61 (G) DATE: SEPTEMBER-1990 (K) RELEVANT RESIDUES I - #N SEQ ID NO:2: FROM 1 TO 80 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: - - Ala Asp Gly Ser Ser Asp Ala Ala Arg Glu Pr - #o Arg Pro Ala Pro Ala 1 5 - # 10 - # 15 - - Pro Ile Arg Arg Arg Ser Ser Asn Tyr Arg Al - #a Tyr Ala Thr Glu Pro 20 - # 25 - # 30 - - His Ala Lys Lys Lys Ser Lys Ile Ser Ala Se - #r Arg Lys Leu Gln Leu 35 - # 40 - # 45 - - Lys Thr Leu Leu Leu Gln Ile Ala Lys Gln Gl - #u Leu Glu Arg Glu Ala50 - # 55 - # 60 - - Glu Glu Arg Arg Gly Glu Lys Gly Arg Ala Le - #u Ser Thr Arg Cys Gln 65 - #70 - #75 - #80 - - - - (2) INFORMATION FOR SEQ ID NO:3: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 35 amino - #acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: peptide - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: - - Arg Ala Tyr Ala Thr Glu Pro His Ala Lys Ly - #s Lys Ser Lys Ile Ser 1 5 - # 10 - # 15 - - Ala Ser Arg Lys Leu Gln Leu Lys Thr Leu Le - #u Leu Gln Ile Ala Lys 20 - # 25 - # 30 - - Gln Glu Leu 35__________________________________________________________________________
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Disclosed are compositions for stabilizing proteins and fragments of the proteins. The composition contains buffer, salt, reducing agents, chelating agents and stabilizing proteins. The composition may be used to prepare highly stable diagnostic calibrators or controls and is particularly useful for calibrators or controls for cardiac markers such as troponin.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the editing of printer output data into an output format, and more particularly to a printer that edits line printer output data into a page printer output format and outputs the data.
2. Description of the Related Art
Japanese Patent Laid-Open Publication No. Hei 5-201077 and Japanese Patent Laid-Open Publication No. Hei 10-329369, in which the prior art is disclosed, will be described. The print control method and the print controller disclosed in Japanese Patent Laid-Open Publication No. Hei 5-201077 will be described with reference to FIG. 12 . Referring to FIG. 12 , a print controller Al, which receives data from a host computer A 10 , processes received data with a master processor module A 100 , a slave processor module A 110 , and a slave processor module A 120 , one page at a time. The commands transferred between the host computer A 10 and the print controller A 1 are classified into two types, constraint commands A 11 A 1 and non-constraint commands A 11 A 2 , as shown in FIG. 13 . Referring to FIG. 14 , the constraint command A 11 A 1 is composed of a command A 92 which defines parameters effective for all pages of a document, a reset command BA 93 , a command string A 94 composed of drawing attribute parameter setting commands and drawing commands, a reset command BA 96 , and a page change A 95 or a page change A 98 which is always added as a page delimiter. Therefore, even if the processors A 100 , A 110 , and A 120 perform processing in parallel, one page at a time, there is no effect on the print result because there is no format information effective across pages and therefore. However, this print control method and the print controller have the following problems.
The first problem is that, when a non-constraint command A 11 A 2 is executed on a printer controller A 11 for printing at a high speed as shown in FIG. 13 , the host computer A 10 must always convert (A 11 B) the non-constraint command to a constraint command. In other words, when the type of the host computer A 10 changes, conversion A 11 B from a non-constraint command to a constraint command is necessary.
The second problem is that, when a non-constraint command A 11 A 2 is printed without being converted to a constraint command A 11 A 1 , it is judged that the page delimiter is issued only when the specification, such as the paper size or the number of copies which are specified for a page only once, is changed at the start of a page. Therefore, when the character size or the line feeding amount is changed while a page is output and, as a result, the number of lines exceeds the page length, the print result is not output correctly.
Next, the printer disclosed in Japanese Patent Laid-Open Publication No. Hei 10-329369 will be described with reference to FIG. 15. A printer B 1 shown in FIG. 15 receives data B 21 from a host computer into the receiving buffer via an interface controller B 4 of a master board B 2 . Format information that is searched for is stored in a format information storage unit B 6 or B 11 . Editing units B 7 and B 12 each reference the received data B 21 and the format information storage unit B 6 or B 11 to start editing. Edited and updated format information and page change information are stored in the format information storage unit B 6 or B 11 . Drawing units B 8 and B 13 process the edited data B 21 and B 25 and generate video output data as drawn data B 26 . A printing unit B 9 receives the drawn data B 26 , manages page numbers, and outputs the video output data to an engine in the DMA output mode. The operation will be described with reference to the timing chart shown in FIG. 16 . In FIG. 16 , when the master board B 2 starts the editing processing of the first page, a slave board B 3 starts the pre-editing processing of the first page. Next, when the master board B 2 starts drawing processing, the slave board B 3 starts editing processing. After the editing processing is completed, changed information is written back into the format information storage unit B 6 or B 11 and the editing processing of the next page starts by referring to that information. Thus, the print result is always valid even for data whose page change code is not definite. However, a processor must wait during editing processing until the editing processing of the preceding page is completed. Therefore, at the time the pre-editing processing is completed, only the editing of the preceding page is completed. The detection of format information and the detection of the page delimiter, performed during the pre-editing processing, become meaningless. The result is that, after pre-editing processing, only the format information set up for the preceding page is copied into the format information storage area. In addition, when data requires much editing time, performance is significantly reduced.
As described above, the problem with the technology disclosed in the former publication is as follows. When a non-constraint command A 11 A 2 is executed on a printer controller A 11 for printing at a high speed, the host computer A 10 must always convert (A 11 B) the non-constraint command to a constraint command. In other words, when the type of the host computer A 10 changes, conversion A 11 B from a non-constraint command to a constraint command for a new computer is necessary. In addition, when a non-constraint command is printed without being converted to a constraint command, it is judged that the page delimiter is issued only when the specification, such as the paper size or the number of copies which are specified for a page only once, is changed at the start of a page. Therefore, when the character size or the line feeding amount is changed while a page is output and, as a result, the number of lines exceeds the page length, the print result is not output correctly.
The problem with the technology disclosed in the latter publication is as follows. After the editing processing is completed, changed information is written back into the format information storage unit B 6 or B 11 and the editing processing of the next page starts by referring to that information. Thus, the print result is always valid even for data whose page change code is not definite. However, a processor must wait during editing processing until the editing processing of the preceding page is completed. Therefore, at the time the pre-editing processing is completed, only the editing of the preceding page is completed. The detection of format information and the detection of the page delimiter, performed during the pre-editing processing, become meaningless. The result is that, after pre-editing processing, only the format information set up for the preceding page is copied into the format information storage area. In addition, when data requires much editing time, performance is significantly reduced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a quick and correct print result for existing data created by non-constraint commands.
It is another object of the present invention to allow a printer to start editing the next page without waiting for the completion of the editing processing of the preceding page in order to increase performance.
To achieve the above objects, the present invention provides a printer which draws page data for outputting one page at a time, the page data being edited from line printer output format to a page format based on format information. The printer comprises one master board and one or more slave boards each executing pre-editing processing in which a temporary page change position delimiting pages is calculated with the data unedited; editing processing in which data in a next page following the temporary page change position is edited based on the format information to define an actual page change position and the temporary page change position is corrected by the actual page change position to define the page data of the next page; and drawing processing in which the page data is drawn, wherein the master board and slave boards execute the pre-editing processing of the data before the editing processing and the drawing processing.
In addition, the master board comprises a basic unit transferring the data and control information to or from processing units and to or from the slave boards, wherein the processing units, all connected to the basic unit, include a receiver which receives the data from a host computer; a receiving buffer in which the data is stored; a pre-editing unit which acquires data from the receiving buffer and calculates the temporary page change position; a second format information storage unit in which format information on a next page following the temporary page change position is stored; a first format information storage unit in which format information common to edited pages is accumulated by obtaining the format information on the edited pages from the second format information storage unit; an editing unit which edits the next page following the temporary page change position defined by the pre-editing unit to define the actual page change position based on the format information stored in the first and second format information storage units, corrects the temporary page change position with the actual page change position, and defines the page data of the next page; a drawing unit which generates drawing data from the page data; a print controller which converts the drawing data into video output data; an output controller which transfers the video output data sent from the print controller and from a print controller of the slave boards to a printer engine to manage a page of the video output data; and a user interface which sends or receives operation information to or from an operator panel operated by a user.
In addition, each of the slave boards comprises a basic unit transferring the data and control information to or from processing units and to or from the master board, wherein the processing units, all connected to the basic unit, include a pre-editing unit which calculates the temporary page change position of data acquired from a receiving buffer; a second format information storage unit in which format information on a next page following the temporary page change position is stored; an editing unit which edits the next page to define the actual page change position based on the format information stored in a first format storage unit in which common format information is stored and in the second format information storage unit, corrects the temporary page change position with the actual page change position, and defines the page data of the next page; a drawing unit which generates drawing data from the page data; and a print controller which converts the drawing data into video output data.
In addition, the receiving buffer cyclically uses a buffer area in which data from the host computer is stored and an area which is used for the editing processing and, when the buffer becomes full before the page change position is detected during the editing processing, stops receiving the data and synchronizes the format information by distributing the so-far received data among the master board and the slave board to avoid a buffer overflow and to continue processing.
In addition, the pre-editing unit checks whether or not statements coded in a page printer description language are present and, when statements coded in the page printer description language are found, defines a position defined by page change information as the page change position and, when there is no statement coded in the page printer description language, calculates the temporary page change position from a number of characters and a number of lines, the temporary page change position delimiting pages.
In addition, the common format information, which is the format information passed across edited paged, includes character pitch information, character size information, left margin information, right margin information, horizontal tab information, vertical tab information, line feeding information, font information, character decoration information, paper size information, print orientation information, number-of-copies information, form information, external character definition information, and page change information.
Also, the printer according to the present invention comprises two or more boards, each comprising a pre-editing unit which performs pre-editing processing in which, in order to delimit received data into pages, format information is extracted from a start of non-delimited data beginning with the start of the received data and a temporary page change position is calculated, the temporary page change position being a trailing end of a page whose leading end is the start of the non-delimited data; an editing unit which performs editing processing in which data following the temporary page change position is edited and an actual page change position is calculated to output editing data of a page, the actual page change position being an actual trailing end of the page whose leading end is the temporary page change position; and a drawing unit which performs drawing processing in which the edited data is drawn and video output data is generated, wherein, when a pre-editing unit of a first board completes first pre-editing processing, a pre-editing unit of a second board where none of pre-editing processing, editing processing, and drawing processing is performed starts pre-editing processing in which, even if the first editing processing calculating an actual page change position of a page whose temporary page change position was calculated by the first pre-editing processing is not yet completed, a temporary page change position of a page beginning with the temporary page change position calculated by the first pre-editing processing is calculated.
According to the present invention, when a pre-editing unit of a board completes pre-editing processing, some other board on which none of pre-editing processing, editing processing, and drawing processing is performed, starts pre-editing processing for calculating a temporary page change position of the next page even if editing processing calculating an actual page change position of the page, for which the temporary page change was calculated by the pre-editing processing, is not yet completed. Therefore, the printer according to the present invention eliminates the need for replacing, via the printer driver or the data filter, existing line-printer user data with data coded in page printer description language, enabling a page printer to print data quickly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the configuration of a printer in a first embodiment of the present invention.
FIG. 2 is a diagram showing format information stored in the format information storage unit shown in FIG. 1 .
FIG. 3 is a diagram showing the timing chart of the printer shown in FIG. 1 .
FIGS. 4A , 4 B, and 4 C are diagrams showing the management of the receiving buffer of the printer shown in FIG. 1 .
FIG. 5 is a diagram showing data acquisition requests issued to the receiving buffer of the printer shown in FIG. 1 .
FIG. 6 is a diagram showing the timing chart when a receiving buffer full condition occurs on the printer shown in FIG. 1 .
FIG. 7 is a diagram showing the configuration of a printer in a second embodiment of the present invention.
FIG. 8 is a diagram showing the timing chart of the printer shown in FIG. 7 .
FIG. 9 is a diagram showing data acquisition requests issued to the receiving buffer of the printer shown in FIG. 7 .
FIG. 10 is a diagram showing the timing chart when a receiving buffer full condition occurs on the printer shown in FIG. 7 .
FIGS. 11A and 11B are diagrams showing examples of printer configurations.
FIG. 12 is a diagram showing the configuration of a print controller in the prior art.
FIG. 13 is a diagram showing the command system of the print controller shown in FIG. 12 .
FIG. 14 is a diagram showing the details of command data of the print controller shown in FIG. 12 .
FIG. 15 is a diagram showing the configuration of a printer in the prior art.
FIG. 16 is a diagram showing the timing chart of the printer shown in FIG. 15 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , a printer 1 used in a first embodiment of the present invention is shown.
As shown in FIG. 1 , the printer 1 comprises a master board 2 and a slave board 3 .
In response to a data send request from a host computer 17 , a receiver 4 of the master board 2 stores data, received from the host computer 17 , into a receiving buffer 20 acquired from a basic unit 7 in advance.
A pre-editing unit 8 issues a data acquisition request to the receiver 4 via the basic unit 7 .
Similarly, the slave board 3 issues a data acquisition request to the receiver 4 via the basic unit 7 connected to a basic unit 12 .
The basic units 7 and 12 provide other processing units with printer internal resources available only to the master board 2 as if those resources were connected to any processor. The printer internal resources available only to the master board 2 include a printer engine 19 , an operator panel 18 , auxiliary storage media not shown in the figure such as a non-volatile memory, a hard disk, and a floppy disk, and a receiving interface.
The receiver 4 receives all data requests from the boards on which processors are mounted. If there is data to be sent, the receiver 4 sends data to the pre-editing unit 8 or 13 . When sending data, the receiver 4 sends the start address and the size of data, not actual data, in order to reduce the overhead time required for copying data between boards.
The pre-editing unit 8 or 13 performs one of two types of processing according to the state of its own processor.
The first processing is performed when its own processor is executing pre-editing processing. In this case, as shown in FIG. 2 , the pre-editing unit 8 or 13 stores format information, which is contained in the pages up to the page immediately preceding the page to be processed by its own processor, from a format information storage unit 21 into a format information storage unit 22 or 23 . The pre-editing unit then detects the page delimiter in the format information, writes back the format information into the format information storage unit 21 via the basic unit 7 or 12 , and informs the receiver 4 that the format information has been written.
The second processing is performed when its own processor is executing editing processing. In this case, the pre-editing unit 8 or 13 sends format information from the format information storage unit 22 or 23 to an editing unit 9 or 14 and edits actual data.
The editing unit 9 or 14 edits actual data based on the format information detected by the pre-editing unit 8 or 13 . When the format information is updated, the editing unit 9 or 14 writes back the format information into the format information storage unit 21 .
A drawing unit 10 or 15 receives edited page data from the editing unit 9 or 13 , generates drawing data, and passes it to a print controller 11 or 16 .
The print controller 11 or 16 generates video output data from the drawing data and passes it to the output controller 6 .
The output controller 6 manages pages, which are output one page at a time, and starts video DMA operation for the printer engine 19 .
Referring to FIG. 2 , page delimiter calculation processing performed by the pre-editing unit 8 or 13 shown in FIG. 1 and the configuration of format information stored in the format information storage units 21 , 22 , and 23 for use by the pre-editing unit 8 or 13 are shown.
The master board 2 has the format information storage unit 22 that is used for the processing of its own processor and the format information storage unit 21 that is shared by the master board 2 and the slave board 3 . On the other hand, the slave board 3 has only the format information storage unit 23 used for the processing of its own processor.
Before pre-editing processing, the common format information stored in the format information storage unit 21 , which is shared by the master board 2 and the slave board 3 , is read into the format information storage unit 22 or 23 used for the processing of its own processor. When pre-editing processing is completed or if a mismatch is found in the format information after editing processing, the format information is written back into the format information storage unit 21 . As a result, the format information storage unit 21 shared by the master board 2 and the slave board 3 stores therein format information common to the pages immediately preceding the page that is to be processed.
The common format information refers to information passed from page to page, that is, format information of the immediately preceding page or format information set up not for the immediately preceding page but for the pages preceding the immediately preceding page. More specifically, the common format information includes character pitch information 211 , character size information 212 , left margin information 213 , right margin information 214 , horizontal tab information 215 , vertical tab information 216 , line feeding width information 217 , font information 218 , character decoration information 219 (reverse print, underline, italic, bold), paper size information 220 , print orientation information 221 (portrait, landscape), form information 222 , external character definition information 223 , number-of-copies information 224 , and page change information 225 .
The pre-editing unit 8 or 13 first checks if there are statements coded in the page printer description language. If there are statements coded in the page printer description language, the pre-editing unit 8 or 13 stores format information existing before the page change information into the format information storage unit 22 or 23 ( 20201 , 20202 , 20203 ). The offset from the start address of the data received from the receiver 4 is stored in the pointer format.
If there is no statement coded in the page printer description language, the pre-editing unit 8 or 13 calculates the page delimiter position from the number of characters and the number of lines and, as with the statements coded in the page printer description language, stores format information existing before the page change information into the format information storage unit 22 or 23 ( 209 ).
A check is made for the number of characters per line considering the fact that the number of lines increases when a right margin overflow is caused by an automatic page change because of too many characters. The format information which may be involved in a right margin overflow includes the character pitch information 211 , character size information 212 , left margin information 213 , right margin information 214 , horizontal tab information 215 , font information 218 , paper size information 220 , and print orientation information (portrait, landscape) 221 .
A check is made for the number of lines considering the fact that a bottom margin overflow may cause an automatic page change. The format information which maybe involved in a bottom margin overflow includes vertical tab information 216 , line feeding width information 217 , and paper size information 220 . In addition, a right margin overflow, which generates the number of lines exceeding the number of lines per page, also causes a bottom margin overflow.
It should be noted that, even if a page delimiter position is detected considering the format information, actual editing processing is not performed. The delimiter position value, which is a calculated value, may include an error. The pre-editing unit 8 or 13 would perform the same processing as the editing unit in order to eliminate this error, meaning that there is no meaning in performing pre-editing processing. Therefore, when an error is generated, the editing unit 9 or 14 changes the page change position 209 calculated during pre-editing processing to the page change position 206 generated as a result of editing processing and stores the corrected value in the format information storage units 21 , and 22 or 23 to allow correct format information to be passed from page to page. ( 206 )
Another function of the pre-editing unit 8 or 13 is to copy all data from the receiving buffer 20 to a local memory of each processor, not shown in the figure, when the receiving buffer 20 becomes full. Because the pre-editing unit 8 or 13 does not release data acquired from the receiver 4 until the page delimiter is detected, this copy operation forces the receiving buffer 20 to be released for continued processing.
Next, the operation of the printer 1 shown in FIG. 1 will be described with reference to the timing chart shown in FIG. 3 while referring to the timing chart, shown in FIG. 5 , of a data acquisition request issued to the receiving buffer 20 . In the example shown in FIG. 3 , the first page 2001 of data 200 stored in the receiving buffer 20 contains double-sided printing data which takes long in drawing. The page change position of each page is not definite, and six pages of print data, page 2001 to page 2006, will be printed beginning with the master board 2 .
First, for the received data 200 stored into the receiving buffer 20 by the receiver 4 shown in FIG. 1 , the same data (start address of the receiving buffer and the size) is sent ( 53 and 54 in FIG. 5 ) in response to a data acquisition request ( 51 in FIG. 5 ) from the pre-editing unit 13 and a data acquisition request ( 52 in FIG. 5 ) from the pre-editing unit 8 . However, because neither the pre-editing unit 8 nor the pre-editing unit 13 has no means for determining which will perform editing processing for the first page, the receiver 4 notifies that editing processing will be performed by the master board 2 and that pre-editing processing will be performed by the slave board 3 .
Because there is no preceding page data, the pre-editing unit 8 of the master board 2 performs no processing but passes actual data to the editing unit 9 for editing processing.
The pre-editing unit 13 of the slave board 3 searches the format information on the first page 2001 for the page change position, stores the format information into the format information storage unit 23 , and updates the format information in the format information storage unit 21 of the master board 2 . The pre-editing unit also updates the read pointer of the receiving buffer 20 and informs the receiver 4 that the pre-editing processing of the first page 2001 has finished ( 58 in FIG. 5 ).
When pre-editing processing 20011 of the first page 2001 is completed, the editing unit 14 starts editing processing 20022 of the second page 2002 without waiting for the completion of the editing processing 20012 of the first page 2001.
When the editing processing 20012 on the master board 2 is completed, the page change position of the first page 2001 detected by the pre-editing unit 13 of the slave board 3 is compared with the page change position detected by the editing unit 9 to check if they are the same.
One of the reasons for a mismatch in the page change position is a character size change during processing of a line. A character size change causes a line pitch change which, in turn, causes a bottom margin overflow and an automatic page change. Also, a character pitch change causes a right margin overflow and an automatic page change, which may increase the number of lines and generate a bottom margin overflow and an automatic page change. If the pre-editing unit 8 or 13 must detect these factors, they would have to perform the same processing as the editing unit 9 or 14 . In this case, the pre-editing unit 8 or 13 according to the present invention, which quickly detects the format information and a page change position and passes them to the next page, becomes meaningless.
When the page change positions ( 200 n 1 and 200 n 2 in FIG. 2 ) differ and the page change position detected by the pre-editing unit 13 is nearer to the start of the acquired received data, information from the page change position detected by the pre-editing unit 13 to the page change position detected by the editing unit 9 is passed to the editing unit 14 .
Because the editing unit 14 performs extra editing, the editing data received from the editing unit 9 is deleted. Conversely, when the page change position detected by the editing unit 9 is nearer to the start of the receiving buffer, the editing unit 9 performs the editing processing of data from the page change position ( 200 n 2 in FIG. 2 ) detected by the editing unit 9 to the page change position ( 200 n 1 in FIG. 2 ) detected by the pre-editing unit 13 and passes the result to the editing unit 14 of the slave board 3 .
In this way, by adjusting editing data with the other processor after completion of the editing processing, the page change position can be detected correctly although the immediately preceding page and the currently-editing page are asynchronous and, at the same time, the correct format information can be passed.
After that, the master board 2 and the slave board 3 perform the drawing processing via the drawing unit 10 or 15 to generate video output data.
The slave board 3 which has completed processing earlier, the print controller 16 passes the pointer to the video output data to the output controller 6 of the master board 2 . At this time, because the master board 2 has not yet completed the drawing processing of the first page ( 20013 in FIG. 3 ), the processing 2003 of the third page is performed again by the slave board 3 .
The slave board 3 references the format information storage unit 21 of the master board 2 , checks that the page change position information has been updated (pre-editing processing 20011 of the first page 2001 in FIG. 3 is completed), and then causes the pre-editing unit 13 to start the pre-editing processing of the second page 2002. When the pre-editing processing 20021 is completed, the editing unit 14 starts editing processing 20032 of the third page 2003 .
When the editing processing 20032 is completed, the page change position 209 detected by the pre-editing unit 13 and the page change position 206 detected by the editing unit 14 are compared. In the example shown in FIG. 3 , there should be no mismatch because the editing processing 20022 of the second page 2002 is already completed. The pre-editing unit 8 of the master board 2 checks that the pre-editing processing 20021 of the second page 2002 is completed and starts pre-editing processing 20031 of the third page.
In this way, instead of alternating processing between the master board 2 and the slave board 3 , one of the two boards whose processor is free can start processing. In addition, when the pages are not delimited definitely, processing across two pages allows editing to be performed quickly with no need for synchronizing editing processing.
As shown in FIGS. 4A , 4 B, and 4 C, the receiving buffer 20 is managed in the ring buffer mode. The write pointer is updated by the receiver 4 , while the read pointer is updated by the pre-editing unit 8 or 13 and by the editing unit 9 or 14 of each processor. The receiver 4 references these pointers to determine which area is being used for editing and into which area data can be received.
In FIG. 4A , a write pointer 401 and a read pointer 402 point to the same position. This state indicates that data in the receiving buffer is not used for editing and that data can be received in any area in the buffer.
In FIGS. 4B and 4C , write pointers 404 and 405 and read pointers 403 , 406 , 407 , and 408 point to different positions. In addition, there are a plurality of read pointers 403 , 407 , 406 , and 408 .
In this case, a search is made for a read pointer in the high-order physical address direction beginning with the position pointed to by the write pointer 404 or 405 . If the read pointer is not found until the end address of the receiving buffer is reached, a search is made again beginning with the start address of the receiving buffer. Data are received into an area from the position pointed to by the write pointer to the position immediately preceding the position pointed to by the read pointer that is found first.
Conversely, an area being used for editing or an area whose data is not yet sent by the receiver 4 for editing begins with the position pointed to by the read pointer 403 or 406 that is detected first and ends with the position immediately preceding the position pointed to by the write pointer. 404 or 405 that is found by making a search in the high-order address direction.
As described above, even when there are a plurality of processors and therefore there are a plurality of read pointers, the receiver 4 checks the write pointer and sends data, which is stored in the positions preceding the position pointed to by the write pointer, to the boards for processing. This prevents editing processing from being performed on data beyond the position pointed to by the write pointer. Therefore, an area from the position pointed to by the lowest-address read pointer to the address pointed to by the write pointer is a memory area which is being used for editing or into which data has been received. This is an area from which the receiver 4 has not yet send data to the boards for editing.
Next, referring to FIG. 6 , the following describes how processing is continued when a large amount of form data or external-character data is received and the receiving buffer becomes full.
When the receiver 4 of the master board 2 receives a large amount of form data or external-character data and a receiving buffer full condition occurs in which no free area is found in the receiving buffer 20 , the receiver stops receiving data. At this time, the editing unit 9 of the master board 2 sends a data acquisition request 52 to the receiver 4 to perform editing processing for the nth page.
On the other hand, the pre-editing unit 13 of the slave board 3 sends a data acquisition request 51 for the nth page to the receiver 4 to perform pre-editing processing for the (n+1)th page.
In response to the data acquisition requests 51 and 52 from all processors, the receiver 4 performs data sending services 53 and 54 for the editing unit 9 of the master board 2 and for the pre-editing unit 13 of the slave board 3 .
Next, the pre-editing unit 13 of the slave board 3 adds a receiving-buffer full parameter to a pre-editing end notification 58 and sends it to the receiver 4 . At this time, the read pointer is not updated.
The pre-editing unit 13 of the slave board 3 , which has not yet detected the page change position, sends a data acquisition request 57 to the receiver 4 again.
However, the receiver 4 which has no data to send cannot perform data sending service for the data acquisition request 57 received from the pre-editing unit 13 of the slave board 3 .
After that, the editing unit 9 of the master board 2 sends an editing end notification 56 to the receiver 4 and updates the read pointer. Then, the editing unit sends a data acquisition request 55 to the receiver because one page of editing processing is not yet completed.
In response to the buffer full notification, the receiver 4 checks that data acquisition requests, 55 and 57 , have been received from all processors. The receiver checks those requests to confirm that all processors has no received data to edit.
After confirming the requests from all processors, the receiver 4 issues a receiving-buffer data copy request to all processors, except the one that is performing editing processing, as a parameter of a data sending service 59 to ask each processor to receive data from the receiving buffer into the local memory of the processor. The receiver does not pass data to a processor which is performing editing processing because data is already copied into the local memory and there is no need to copy data any more. Upon receiving the request, the pre-editing unit 13 stores data into the local memory, informs the receiver 4 , through a parameter of a pre-editing end notification 60 , that the restoration of the receiving-buffer full condition is completed, and then updates the read pointer.
The receiver 4 , which has confirmed the notifications from all processors, resumes data reception and performs data sending services 61 and 62 , each of which is not yet completed for a page, for the editing unit 9 of the master board 2 and the pre-editing unit 13 of the slave board 3 .
The problem with a prior-art printer is that, when the page delimiter cannot be detected because the pre-editing unit 8 or 13 has not yet completed one page of pre-editing processing, subsequent editing processing cannot be performed. The printer described above prevents this condition from occurring.
As a second embodiment of the present invention, a printer 100 with a plurality of slave boards 3 will be described. FIG. 7 shows the configuration of the printer 100 with four slave boards 30 , 31 , 32 , and 33 . The operation will be described by referring to the timing chart shown in FIG. 8 and the data acquisition requests shown FIG. 9 . In the example shown in FIG. 8 , the first page 2001 contains double-sided printing data which takes long in drawing. The page change position of each page is not definite, and six pages of print data, page 2001 to page 2006, will be printed beginning with the master board 2 .
The receiver 4 shown in FIG. 7 stores data 200 in the receiving buffer 20 .
The pre-editing units of the master board 2 and all slave boards 30 , 31 , 32 , and 33 send data acquisition requests 301 , 302 , 303 , 304 , and 305 to the receiver 4 .
Upon recognizing the data acquisition requests from all processors, the receiver 4 performs the data sending services 311 and 312 to send the same data (start address of the receiving buffer and the size) to the pre-editing unit 8 of the master board 2 and the pre-editing unit 13 of the slave board 30 . Because there is no means for the pre-editing units to know which processor is to perform editing processing for the first page 2001, the receiver 4 notifies that editing processing will be performed by the master board 2 and that pre-editing processing will be performed by the slave board 30 .
Because there is no data preceding the first page 2001, the pre-editing unit 8 of the master board 2 performs no processing but passes actual data to the editing unit 9 for performing editing processing.
The pre-editing unit 13 of the slave board 30 searches the format information on the first page 2001 for the page change position, stores the format information into the format information storage unit 23 , and updates the format information in the format information storage unit 21 of the master board 2 . The pre-editing unit also updates the read pointer of the receiving buffer 20 and informs the receiver 4 that the pre-editing processing of the first page 2001 has finished ( 321 ).
When the pre-editing processing of the first page 2001 in FIG. 8 is completed ( 321 ), the pre-editing unit 13 of the slave board 30 issues a data acquisition request 306 again as an editing request.
The receiver 4 allows the editing unit 14 of the slave board 30 to start the editing processing of the second page 2002 without waiting for the completion of the editing processing of the first page 2001.
In addition, the receiver 4 sends ( 340 ) data stored in the position pointed to by the updated read pointer and in the following positions to the pre-editing unit 13 of the slave board 30 as the pre-editing data of the second page 2002.
When the editing processing on the master board 2 is completed ( 331 ), the page change position detected by the pre-editing unit 13 of the slave board 30 is compared with the page change position detected by the editing unit 9 to check if they are the same. When the page change positions differ and the page change position detected by the pre-editing unit 13 is nearer to the start of the acquired received data, information from the page change position detected by the pre-editing unit 13 to the page change position detected by the editing unit 9 is passed to the editing unit 14 . Because the editing unit 14 performs extra editing, the editing data received from the editing unit 9 is deleted. Conversely, when the page change position detected by the editing unit 9 is nearer to the start of the receiving buffer, the editing unit 9 performs the editing processing of data from the page change position detected by the editing unit 9 to the page change position detected by the pre-editing unit 13 and passes the result to the editing unit 14 of the slave board 30 .
In this way, by adjusting editing data with the other processor after completion of the editing processing, the page change position can be detected correctly although the immediately-preceding page and the currently-editing page are asynchronous and, at the same time, the correct format information can be passed.
Similarly, on the slave board 31 , the editing data of the second page 2002 processed by the slave board 30 is compared with the page delimiter position detected by the pre-editing unit of the slave board 31 for corrected editing processing. In this manner, even when the slave boards 30 , 31 , 32 , and 33 are used, the operation is performed in the same manner as when the master board 2 and one slave board are used. Added processors reduce the load of each processor, thus improving performance.
In addition, referring to FIG. 10 , the following describes how processing is continued when a large amount of form data or external-character data is received and the receiving buffer becomes full.
When the receiver 4 of the master board 2 receives a large amount of form data or external-character data and a receiving buffer full condition occurs in which no free area is found in the receiving buffer 20 , the receiver stops receiving data. At this time, the editing unit 9 of the master board 2 sends a data acquisition request 301 to the receiver 4 to perform editing processing for the mth page.
The pre-editing unit 13 of the slave board 30 sends a data acquisition request 302 for the mth page to the receiver 4 to perform pre-editing processing for the editing processing of (m+1)th page. In response to the data acquisition requests 301 - 305 from all processors, including the data acquisition requests 303 - 305 from the slave boards 31 - 33 which have already issued data acquisition requests, the receiver 4 performs data sending services 311 and 312 for the editing unit 9 of the master board 2 and for the pre-editing unit 13 of the slave board 30 .
Next, the pre-editing unit 13 of the slave board 3 adds a receiving-buffer full parameter to a pre-editing end notification 321 and sends it to the receiver 4 . At this time, the read pointer is not updated.
The pre-editing unit 13 of the slave board 3 , which has not yet detected the page change position, sends a data acquisition request 306 to the receiver 4 again. However, the receiver 4 which has no data to send cannot perform data sending service for the data acquisition request 306 received from the pre-editing unit 13 of the slave board 30 .
After that, the editing unit 9 of the master board 2 sends an editing end notification 331 to the receiver 4 and updates the read pointer. Then, the editing unit sends a data acquisition request 307 to the receiver because one page of editing processing is not yet completed.
In response to the buffer full notification, the receiver 4 checks that data acquisition requests 307 , 306 , 303 , 304 , and 305 have been received from all processors. The receiver checks those requests to confirm that all processors has no received data to edit.
After confirming the requests from all processors, the receiver 4 issues receiving-buffer data copy requests 313 , 314 , 315 , and 316 to all processors, except the one that is performing editing processing, as a parameter of data sending services 313 , 314 , 315 , and 316 to ask each processor to receive data from the receiving buffer 20 into the local memory of the processor. The receiver does not pass data to a processor which is performing editing processing because data is already copied into the local memory and there is no need to copy data any more.
Upon receiving the request, the pre-editing unit 13 of the slave board 30 , the pre-editing unit (not shown) of the slave board 31 , the pre-editing unit (not shown) of the slave board 32 , and the pre-editing unit (not shown) of the slave board 33 store data into the local memory, inform the receiver 4 , through a parameter of pre-editing end notifications 322 , 323 , 324 , and 325 , that the restoration of the receiving-buffer full condition is completed, and then updates the read pointer.
The receiver 4 , which has confirmed the notifications from all processors, resumes data reception and performs data sending service 317 , which is not yet completed for one full page, for the editing unit 9 of the master board 2 and the pre-editing unit 13 of the slave board 30 .
As described above, reception processing and video output processing are executed in the DMA mode. Therefore, the page-basis parallel processing, from editing to drawing, is performed in parallel, and most of the processing time is used for parallel processing. This means that performance increases as more slave boards are used. Therefore, the number of slave boards should be decreased for low-speed engines, and increased for high-speed engines, to enable the same algorithm to cover a wide range of printers, from low-speed to high-speed.
In addition, the programmable configuration of a user interface 5 and the output controller 6 shown in FIG. 1 and the definite definition of an interface (data exchange protocol) between the basic unit 7 and the processing unit allow the same algorithm to implement the function by simply changing the user interface 5 and the output controller 6 with no effect on other processing units even when the specifications of the operator panel 18 and the printer engine 19 are changed.
The operation of the output controller 6 in the printer configuration shown in FIGS. 11A and 11B will be described. Each of the two printer engines in this example has its own print order during double-sided printing. FIG. 11A shows printer A with a printer engine whose paper transport path is short. The printer transports two pieces of paper at a time. In this printer A, the first paper is supplied and print data is fixed on the face of the first paper transported in the direction of arrow 501 , and the paper is transported in the direction of arrow 502 . Next, the second paper is supplied in the direction of arrow 501 , print data is fixed on the face of the second paper, and the paper is transported in the direction of arrow 502 . After that, the first paper is transported in the direction of arrow 503 , print data is fixed on the reverse of the first paper, and the paper is ejected in the direction of arrow 504 . Finally, print data is fixed on the reverse of the second paper, and the paper is ejected in the direction of arrow 504 . In this way, the print order is the face of the first paper, the face of the second paper, the reverse of the first paper, the reverse of the second paper, the face of the third paper, and so on.
FIG. 11B shows printer B with a printer engine whose paper transport path is long. This printer transports three pieces of paper at a time. In this printer B, the first paper is supplied, print data is fixed on the face of the first paper transported in the direction of arrow 601 , and the paper is transported in the direction of arrow 602 . Next, the second paper is supplied in the direction of arrow 601 , print data is fixed on the face of the second paper, and the paper is transported in the direction of arrow 602 . At this time, the first paper is transported in the direction of arrow 603 . Then, the third paper is supplied in the direction of arrow 601 . After that, the transportation operations of the three pieces of paper in printer B are interrelated. That is, when the first paper is supplied in the direction of arrow 604 , the second paper is transported in the direction of arrow 603 , the third paper is transported in the direction of arrow 602 , and print data is fixed on the reverse of each paper. After printed data is fixed, the papers are transported in the direction of arrows 605 and 606 and reverse-ejected. In this case, the print order is the reverse of the first paper, the reverse of the second paper, the reverse of the third paper, the face of the first paper, the face of the second paper, the face of the third paper, the reverse of the fourth paper, and so on. For a printer engine with a feature that does not reverse-eject papers to increase print performance (paper is transported in the direction of arrow 607 ), the print order is the face of the first paper, the face of the second paper, the face of the third paper, the reverse of the first paper, the reverse of the second paper, the reverse of the third paper, the face of the fourth paper, and so on. The print order is one of control methods for maximizing the print performance of the printer. For data requiring long in editing or drawing such as the one shown in FIG. 4 or FIG. 8 or for two pages of data (one piece of paper), another control method may be used. Considering all these cases, print data is queued on a page basis with the print order controlled by pointers. This allows pages to be re-ordered simply by changing the queue (pointers), making the management easy.
A plurality of programs may be prepared for the user interface 5 and the output controller 6 to allow a program best suited for the device configuration to be selected.
As described above, the printer according to the present invention eliminates the need for replacing, via the printer driver or the data filter, existing line-printer user data with data coded in page printer description language, enabling a page printer to print data quickly and correctly. In addition, even when a large amount of form data or external character data exceeding the receiving buffer size is received, the printer may continue printing without having to check whether editing is completed for one full page.
While this invention has been described in conjunction with the preferred embodiments described above, it will now be possible for those skilled in the art to put this invention into practice in various other manners.
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A printer has two or more boards. Each board comprises a pre-editing unit which extracts format information from the start of non-delimited received data to sequentially delimit the data into pages beginning with the start of the received data and calculates a temporary page change position that is the trailing end of one page whose start is the leading end of the non-delimited data, an editing unit which edits data following the temporary page change position, calculates an actual page change position that is the trailing end of one page whose leading end is the temporary page change position, and outputs the editing data of the page, and a drawing unit which performs drawing processing in which the editing data is drawn and video output data is output. In addition, when the pre-editing unit of a board completes pre-editing processing, the pre-editing unit of some other board, on which none of pre-editing processing, editing processing, and drawing processing is performed, starts pre-editing processing for calculating a temporary page change position of the next page even if editing processing calculating an actual page change position of the page, for which the temporary page change was calculated by the pre-editing processing, is not yet completed.
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RELATED APPLICATION
[0001] This application incorporates in full and claims the full benefit of Provisional Patent Application No. 60/373,413 filed Apr. 17, 2002.
TECHNICAL FIELD
[0002] This invention pertains the use of particular heat transfer fluids to maintain desired densities and temperatures in combustion air for a gas turbine.
BACKGROUND OF THE INVENTION
[0003] It is known to cool or heat the inlet combustion air to gas turbines to obtain a desired enthalpy. An excellent explanation of the relationships of relative humidity, wet and dry bulb temperature, and specific volume of air as they affect enthalpy is provided in Smith, McCloskey and Cates U.S. Pat. No. 5,390,505, which is incorporated herein by reference in its entirety. See particularly the psychrometric chart of FIG. 9.
[0004] In addition, the combustion air consumed by a gas turbine may require heating to prevent ice formation as a function of dew point at ambient temperatures below about 43 degrees F. It is also known that, where ambient temperatures are above about 43 degrees F., cooling the combustion air going to a gas turbine will result in increased power output of the gas turbine. Temperature affects air density, and turbine efficiency is in turn affected by the density of the intake air. It is desirable to control the temperature of the heat exchange fluid in the coils of a turbine which contact the incoming air, to achieve greater power output and efficiency and at the same time prevent icing on the outside of a heat exchange coil. Icing on the outside of the coils is quite undesirable, mostly because ice formation can damage the gas turbine if ingested but also because it decreases the heat exchange in the areas affected, and also impedes the flow of air through the intake. The temperature control can be programmed to take into account the factors which affect the desired outcome. As is known in the art, in many cases it may not be necessary to heat the air to a temperature above 32° F.; indeed in many cases (because of the moisture content of the air at the ambient temperature and density) one need only heat the incoming air from −20°, for example, to −110° F., in order to inhibit icing on the outside of the coil.
[0005] As illustrated in the above referenced U.S. Pat. No. 5,390,505, the efficiency of the gas turbine may be enhanced by either increasing or decreasing the temperature of the intake air under various circumstances. The air density may vary as a function of the air temperature: “Provision of reduced temperature or increased density air rather than ambient air to a gas turbine-generator generally provides an increase in turbine efficiency and output capacity or generator KW”. Column 7, lines 58-61. The improvement in turbine-generator efficiency is illustrated In FIG. 10 of that patent, where water vapor concentration is considered also as a factor in plotting enthalpy.
[0006] Fluid heat transfer coils have been successfully used to cool the intake air, using heat exchange fluids such as water, ethylene glycol solution, propylene glycol solution or alcohol brines in direct or indirect contact with the combustion air. But many of the fluids used in the past, such as ethylene glycol or propylene glycol, are hazardous pollutants and have regulatory classifications. Moreover, many cooling fluids conventionally used in gas turbines, such as the glycols, tend to become very viscous as the working temperature is reduced, which is counterproductive to the purpose of improving heat transfer efficiency for lowering the temperature of the air to increase its density. A highly viscous heat exchange fluid will tend to have a low Reynolds Number—that is, its flow will tend to be laminar rather than turbulent, thus decreasing its heat transfer efficiency. And, more energy will be required to pump it. While plain water has good heat transfer efficiency and viscosity characteristics, its freeze point clearly limits its low temperature acceptability.
[0007] DeVault, in U.S. Pat. No. 5,555,738, teaches use of an ammonia water refrigeration system to cool the inlet air of a gas turbine for improved efficiency. Lewis et al, in U.S. Pat. No. 6,195,997, disclose an energy recovery system using a refrigeration loop to cool the inlet air for a gas turbine.
[0008] Hallman et al SPE paper # 65616 teaches use of aqueous formates to improve thermal performance of line heaters in gas production and transmission systems. See also Smith et al U.S. patent application Ser. No. 09/788,115 filed Feb. 16, 2001.
[0009] It would be desirable to control the temperature of the incoming combustion air in a gas turbine to obtain an optimum power output and efficiency, using a fluid having good heat exchange properties and also a low viscosity at low temperatures.
SUMMARY OF THE INVENTION
[0010] Our invention includes a method of enhancing the efficiency of a gas turbine having a heat exchanger for intake air, the heat exchanger including a heat exchange fluid, comprising (a) determining a desired air temperature range for the intake air, and (b) using as the heat exchange medium a fluid, preferably an aqueous alkali metal formate (more preferably sodium or potassium formate or a mixture thereof) solution, having a concentration and viscosity within ranges known to provide a desired heat exchange rate to achieve at least one temperature within the desired air temperature range in the heat exchanger. More preferably the heat exchange fluid will comprise an aqueous solution of potassium formate. Preferably also the solution will be chosen for its heat exchange efficiency, its freezing point, and its heat capacity—that is, the benefits of a viscosity within the desired range and the benefits of heat exchange efficiency and heat capacity for a range of concentrations of alkali metal formate, with or without other constituents in the solution, will be balanced to achieve an optimum overall efficiency. Persons skilled in the art may wish to consult site-specific minimum design ambient freezing temperatures published by the National Oceanographic and Seismic Association—that is, the solution will be designed to have a freeze point at least as low as the site-specific minimum design freezing temperature. The cooling solution formulation will, in addition, desirably have a viscosity in a low range of solutions meeting such freeze point criteria. The alkali metal formate solution will desirably include a corrosion inhibitor.
[0011] Our invention also includes a method of enhancing the power output and efficiency of a gas turbine having an air inlet comprising regulating the temperature of the air in the air inlet to a temperature calculated to provide a desired air density, the regulation of air temperature brought about at least partially by a heat exchange fluid comprising an alkali metal formate, preferably potassium formate.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Aqueous solutions of potassium and other alkali metal formate have lower freeze points and lower viscosities than comparable (having equal concentrations) ethylene or propylene glycol heat exchange fluids, and, unlike the glycols, have no notably harmful environmental effects. Aqueous potassium formate solutions are not flammable, are non-toxic to humans and other species, and are biodegradable, having a very low Biochemical Oxygen Demand (BOD), which reduces the risk of fish kills compared with ethylene or propylene glycol solutions.
[0013] An aqueous solution of 27 percent by weight potassium formate has a density of 10.04 pounds per gallon (1.205 SG); its coefficient of expansion is 2.25×10 −4 , and a freeze point of about −10° F. Other characteristics of a 27% potassium formate solution are as follows:
Thermal conductivity, expressed as BTU/(hrs · ft 2 )(° F./ft): Temp (° F.) 7 32 73.4 141.8 165.2 .252 .259 .273 .299 .308 Specific Heat, (BTU/lb · ° F.) Temp (° F.) 1.4 14 32 50 68 86 104 122 140 158 176 .717 .722 .728 .733 .739 .743 .749 .752 .755 .758 .761 Temp (° F.) −5 0 10 20 30 45 70 133 197 Viscos, cp 6.01 5.00 3.96 3.35 2.81 2.21 1.78 0.905 0.618
[0014] A comparison of the physical properties of solutions of Potassium formate to ethylene glycol and propylene glycol is shown in Table 1.
TABLE 1 50 wt % 50 Wt % 27 Wt % Ethylene Propylene Potassium Fluid Condition Glycol (1) Glycol (2 Formate Freeze Point −29 −28 −10 Deg F. Heat Capacity @20 F. 0.759 0.820 0 724 (BTU/lb F.) @120 F. 0.811 0.871 0.752 Viscosity (Cp) @20 F. 10.85 27.83 3.35 @120 F. 1.82 2.36 1.01 Thermal @20 F. 0.207 0.199 0.255 Conductivity @120 F. 0.230 0.217 (BTU/ hr-ft-F-ft) Regulatory Toxic Hazardous Air None Classification Chemical (S) Pollutants (C) Hazardous Air Pollutants (C) Oral Toxicity 786 ml Not applicable Not Human applicable (mg/kg) Bio- >40% >40% 96% degradation-% degraded in 28 days 5 Day 780 1120 91 (3) Biochemical Oxygen Demand (mg O 2 / g product Theoretical 1290 1680 95 (3) Oxygen Demand (mg O 2 / g product)
EXAMPLE 1
[0015] A gas turbine inlet air thrust augmentation cooling system was used to demonstrate the invention. Heat exchange fluids were compared in the same heat exchange system, a GE PG-7241(FA) gas under ambient air conditions of 96° F. Dry Bulb, 780 F Wet Bulb, and sea level elevation. The Indirect heat exchangers had the following characteristics: total cross section of 1798 square foot face area, fin pitch of 1.5″×1.75″ triangular, (96) 0.011″ thick flat plate aluminum fins, 0.625″ nominal diameter 0.024″ thick copper tubes, and 4 fluid pass circuitry. The exchanger performance was calculated based on an Industrial Heat Transfer, Inc. proprietary sizing program (“Techdat 1”) but the performance estimated is similar to other coil manufacturers programs and believed to be representative of the results, which would be obtained with other similar coil sizing programs from other manufacturers. Using a constant 36° F. entering fluid temperature and 8000 GPM total fluid flowrate, different heat exchange fluids in the same heat exchanger will cool the gas turbine inlet air stream to different temperatures and the gas turbine will achieve different power outputs. As shown in Table 2, in the case of the ethylene glycol circulating stream, the air to the gas turbine is cooled to 49.7 F and the turbine produces a maximum of 174,350 Kw power with a heat rate of 9324 BTU/kWh LHV (lower heating value). In the case of the propylene glycol circulating stream, the air to the gas turbine is cooled to 55.2 F and the turbine produces a maximum of 171,630 Kw power with a heat rate of 9361 BTU/kW LHV. With the preferred Potassium formate circulating stream, the air to the gas turbine is cooled to 45.5 F and the turbine produces a maximum of 176,330 Kw power with a heat rate of 9305 BTU/kWh LHV. In addition, additional efficiency savings will be realized in the refrigeration system supplying the chilled 36 F circulating stream because the heat transfer exchanger in this system will be more thermally efficient with reduced approach temperature for a given heat transfer surface with the Potassium formate working fluid. Chiller power consumption may be reduced, and the capacity of this system is increased by the use of the potassium formate heat exchange fluid.
TABLE 2 50% 50% 38% Ethylene Propylene Potassium Fluid Glycol Glycol Formate Entering Fluid Temperature (F.) 36 36 36 Leaving Fluid Temperature (F.) 58.3 53.4 58.4 Air to Gas Turbine (F.) 49.7 55.2 45.5 Total Fluid Flowrate (GPM) 8000 8000 8000 Fluid Pressure Drop thru Coil 37 44 27.8 (PSI) Turbine Power Output (Kw) 174,350 171,630 176,330 Turb. Heat Rate BTU/kWh LHV 9324 9361 9305
[0016] A perspective of the effect of viscosity of the heat exchange fluid in a turbine may be seen from Table 3. For heat exchange fluids having the same freeze points, here shown at −20° F., 0° F., and 8° F., the alkali metal formates at all levels of concentrations have significantly lower viscosities and accordingly are not only more efficiently circulated, but provide superior heat exchange because of their comparitively turbulent contate with the heat exchange surface.
TABLE 3 30% Potas- 45% 21% 35% 22% 30% sium Ethylene potassium ethylene sodium propylene Formate glycol formate glycol formate glycol Freeze −20° F. −20° F. 0° F. 0° F. 8° F. 8° F. point Vis- cosity at 20° F. 3.6Cp 9.75 3.1 6.75 5.8 15.5 30° F. 2.9 6.9 2.6 4.95 4.5 7.1 40° F. 2.6 5.9 2.3 4.1 3.8 5.7 50° F. 2.3 4.8 2 3.5 3.1 4.5 60° F. 2 4.1 1.7 3.1 2.6 3.6
[0017] It is clear from the above that the heat exchange properties and viscosities of alkali metal formate solutions at low temperatures enable one to regulate the temperature of the intake air to achieve a high degree of power generation efficiency. One may also use the same fluid to heat the air inhibiting the formation of ice on the heat exchange coils. Thus, it may be said that our invention is a method of regulating the power output and efficiency of a gas turbine having an air inlet comprising selecting a desired temperature range for air in the air inlet to achieve an air density to provide a range of power output and efficiency for the gas turbine and regulating the temperature of air in the air inlet to a temperature within the desired temperature range with a heat exchange fluid comprising alkali metal formate. Preferably, the heat exchange fluid is an aqueous solution 5-70% by weight potassium formate, which may include 1-60% by weight of a glycol having up to six carbon atoms. In another aspect, our invention comprises a method of enhancing the power output and efficiency of a gas turbine having a heat exchanger for intake air, the heat exchanger including a heat exchange fluid and a heat exchange surface in contact with the intake air and the heat exchange fluid, comprising (a) determining a desired air temperature range for the intake air taking into account the ambient density of the air, (b) determining a desired viscosity range for the heat exchange fluid in the heat exchanger to efficiently achieve the desired air temperature range, (c) using as the heat exchange fluid an aqueous solution comprising an alkali metal formate, the aqueous alkali metal formate solution having a viscosity within said desired viscosity range. In another aspect, our invention includes a method of inhibiting ice formation on the heat exchange surfaces of an air intake for a combustion turbine, wherein the ambient air temperature of air approaching said air intake is below 43° F., and wherein said heat exchange surfaces are contacted by a heat exchange fluid, comprising utilizing as said heat exchange fluid an aqueous solution comprising potassium formate or sodium formate. A similar solution may be used when the ambient air temperature is less than 32° F., 20° F., or 0° F. In each case, a solution comprising potassium formate, preferably between 5% and 70% by weight, is preferred.
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Air intake temperature in a gas turbine is regulated by a heat exchange fluid having a low viscosity at low temperatures. The circulated heat transfer fluid preferably comprises an alkali metal formate, most preferably potassium formate. The potassium formate may be blended with other alkali metal formate(s), with alcohol, glycols, salt brines, or any combination of glycols, alcohols, Sodium Nitrite, Sodium Nitrates, Potassium Chloride, Sodium Chloride, water and/or or other salt brines.
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This application is a continuation-in-part of application Ser. No. 08/413,224, filed Mar. 30, 1995, now U.S. Pat. No. 5,596,055.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing a styrenic polymer. More particularly, it pertains to a process for producing a styrenic polymer having a high degree of syndiotactic configuration efficiently and inexpensively.
2. Description of the Related Arts
In recent years, a process for producing a styrenic polymer having a syndiotactic configuration (hereinafter sometimes referred to as "SPS") by polymerizing a styrenic monomer by means of a catalyst comprising a transition metal compound as a primary ingredient, especially a titanium compound and methylaluminoxane (refer to Japanese Patent Application Laid-Open No. 187708/1987) has been proposed.
There has also been proposed a process for efficiently producing such a styrenic polymer (SPS) by the use of a catalyst comprising a coordination complex compound composed of an anion in which a plurality of radicals are bonded to a metal and a cation, while dispensing with an aluminoxane which is expensive and is to be used in a large amount (refer to Japanese Patent Application Laid-Open Nos. 415573/1990, 415574/1990, etc.)
In the case of polymerizing a styrenic monomer by the use of the above-mentioned catalyst, there has heretofore been employed an alkylaluminum as a chain transfer agent for the purpose of modifying the molecular weight of the objective polymer. However, this method involves the problems that the catalytic activity deteriorates resulting in an increase in the amounts of residual metals contained in the styrenic polymer thus produced, allowing the decomposed product of an alkylaluminum to remain in the objective polymer. Even in the case of raising the polymerization temperature, the deterioration of the catalytic activity increases the amount of residual metals in the objective polymer. The aforesaid situation calls for the development of a process capable of producing a styrenic polymer of high performance at a low cost, while enabling a decrease in the molecular weight of the resultant polymer and simplifying the process itself without deteriorating the catalytic activity.
As a result of intensive research and investigation made by the present inventors under such circumstances, it has been found that in the case of polymerizing a styrenic monomer by the use of a transition metal compound, a coordination complex compound composed of an anion in which a plurality of radicals are bonded to a metal and a cation, or methylaluminoxane, and an alkylating agent as principal components, the use of a reaction product between a straight-chain alkylaluminum having at least two carbon atoms and water can lower the molecular weight of the resultant polymer without deteriorating the catalytic activity. The present invention has been accomplished on the basis of the above-mentioned finding and information.
SUMMARY OF THE INVENTION
Specifically, the present invention provides a process for producing a styrenic polymer which comprises polymerizing a styrenic monomer by the use of (a) a transition metal compound, (b) a coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a cation, or methylaluminoxane, (c) an alkylating agent and (d) a reaction product between a straight chain alkylaluminum having at least two carbon atoms and water.
DESCRIPTION OF PREFERRED EMBODIMENT
As an (a) transition metal compound usable in the process of the present invention, mention may be made of a variety of compounds, usually the compound represented by the general formula (I) or (II)
MR.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c R.sup.4.sub.4-(a+b+c)(I)
MR.sup.1.sub.d R.sup.2.sub.e R.sup.3.sub.3-(d+e) (II)
wherein M is a metal belonging to any of the groups 3 to 6 of the Periodic Table or a lanthanum series metal; R 1 , R 2 , R 3 and R 4 are each an alkyl group, an alkoxyl group, an aryl group, a cyclopentadienyl group, an alkylthio group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a fluorenyl group, a halogen atom or a chelating agent; a, b and c are each an integer of from 0 to 4; d and e are each an integer of from 0 to 3; and any two of R 1 to R 4 may form a complex which is crosslinked with CH 2 , Si(CH 3 ) 2 or the like.
As a metal belonging to any of the groups 3 to 6 of the Periodic Table or a lanthanum series metal as indicated by M, there are preferably employed the group 4 metals, especially titanium, zirconium, hafnium and the like.
Various titanium compounds can be used and a preferred example is at least one compound selected from the group consisting of titanium compounds and titanium chelate compounds represented by the general formula (III) or (IV):
TiR.sup.5.sub.e R.sup.6.sub.f R.sup.7.sub.g R.sup.8.sub.4-(a+b+c)(III)
TiR.sup.5.sub.h R.sup.6.sub.i R.sup.7.sub.3-(d+e) (IV)
wherein R 5 , R 6 , R 7 and R 8 are each a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, an arylalkyl group, an acyloxyl group having 1 to 20 carbon atoms, a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a fluorenyl group, an alkylthio group, an arylthio group, a chelating agent, an amino group, an amide group, a phosphorus-containing group or a halogen atom; a, b and c are each an integer from 0 to 4; a and e are each an integer from 0 to 3; and any two of R 5 to R 8 may form a complex which is crosslinked with CH 2 , Si(CH 3 ) 2 or the like.
R 5 , R 6 , R 7 and R 8 in the general formulae (III) and (IV) each represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (specifically, methyl group, ethyl group, propyl group, butyl group, amyl group, isoamyl group, isobutyl group, octyl group and 2-ethylhexyl group), an alkoxyl group having 1 to 20 carbon atoms (specifically, methoxyl group, ethoxyl group, propoxyl group, butoxyl group, amyloxyl group, hexyloxyl group, and 2-ethylhexyloxyl group), an aryl group having 6 to 20 carbon atoms, an alkylaryl group, an arylalkyl group (specifically, phenyl group, tolyl group, xylyl group and benzyl group), an acyloxyl group having 1 to 20 carbon atoms (specifically, heptadecylcarbonyloxy group), a cyclopentadienyl group, a substituted cyclopentadienyl group (specifically, methylcyclopentadienyl group, 1,2-dimethylcyclopentadienyl group, pentamethylcyclopentadienyl group and 4,5,6,7-tetrahydro-1,2,3-trimethylindenyl group), an indenyl group, a substituted indenyl group (specifically, methylindenyl group, dimethylindenyl group, tetramethylindenyl group and hexamethylindenyl group), a fluorenyl group, (specifically, methylfluorenyl group, dimethylfluorenylgroup, tetramethylfluorenyl group and octamethylfluorenyl group), an alkylthio group (specifically, methylthio group, ethylthio group, butylthio group, amylthio group, isoamylthio group, isobutylthio group, octylthio group and 2-ethylhexylthio group), an arylthio group (specifically, phenylthio group, p-methylphenylthio group and p-methoxyphenylthio group), a chelating agent (specifically, 2,21-thiobis (4-methyl-6-tert-butylphenyl) group, or a halogen atom (specifically, chlorine, bromine, iodine and fluorine). These R 5 , R 6 , R 7 , R 8 may be the same as or different from each other.
More desirable titanium compounds include a titanium compound represented by the formula (V)
TiRXYZ (V)
wherein R represents a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a fluorenyl group, or the like; X, Y, and Z, independently of one another, are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxyl group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, an alkyl- or arylamide group having 1 to 40 carbon atoms or a halogen atom. Here, any one of X, Y and Z and R may form a compound which is crosslinked with CH 2 , SiR 2 or the like.
The substituted cyclopentadienyl group represented by R in the above formula is, for example, a cyclopentadienyl group substituted by at least one of an alkyl group having 1 to 6 carbon atoms, more specifically, methylcyclopentadienyl group, 1,2-dimethylcyclopentadienyl group, 1,2,4-trimethylcyclopentadienyl group, 1,2,3,4-tetramethylcyclopentadienyl group, trimethylsilylcyclopentadienyl group, 1,3-di(trimethylsilyl) cyclopentadienyl group, tert-butylcyclopentadienyl group, 1,3-di(tert-butyl)cyclopentadienyl group, pentamethylcyclopentadienyl group or the like. In addition, X, Y, and Z are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (specifically, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, octyl group and 2-ethylhexyl group), an alkoxyl group having 1 to 12 carbon atoms (specifically, methoxyl group, ethoxyl group, propoxyl group, butoxyl group, amyloxyl group, hexyloxyl group, octyloxyl group and 2-ethylhexyloxyl group), an aryl group having 6 to 20 carbon atoms (specifically, phenyl group and naphthyl group), an aryloxyl group having 6 to 20 carbon atoms (specifically, phenoxyl group), an arylalkyl group having 6 to 20 carbon atoms (specifically, benzyl group), an alkyl-or-arylamide group having 1 to 40 carbon atoms (specifically, dimethylamide group, diethylamide group, diphenylamide group and methylphenylamide group) or a halogen atom (specifically, chlorine, bromine, iodine and fluorine).
Specific examples of the titanium compound represented by the general formula (V) include cyclopentadienyltrimethyltitanium, cyclopentadienyltriethyltitanium, cyclopentadienyltripropyltitanium, cyclopentadienyltributyltitanium, methylcyclopentadienyltrimethyltitanium, 1,2-dimethylcyclopentadienyltrimethyltitanium, 1,2,4-trimethylcyclopentadienyltrimethyltitaniam, 1,2,3,4-tetramethylcyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltriethyltitanium, pentamethylcyclopentadienyltripropyltitanium, pentamethylcyclopentadienyltributyltitanium, cyclopentadienylmethyltitanium dichloride, cyclopentadienylethyltitanium dichloride, pentamethylcyclopentadienylmethyltitanium dichloride, pentamethylcyclopentadienylethyltitanium dichloride, cyclopentadienyldimethyltitanium monochloride, cyclopentadienyldiethyltitanium monochloride, cyclopentadienyltitanium trimethoxide, cyclopentadienyltitanium triethoxide, cyclopentadienyltitanium tripropoxide, cyclopentadienyltitanium triphenoxide, pentamethylcyclopentadienyltitanium trimethoxide, pentamethylcyclopentadienyltitanium triethoxide, pentamethylcyclopentadienyltitanium tripropoxide, pentamethylcyclopentadienyltitanium tributoxide, pentamethylcyclopentadienyltitanium triphenoxide, cyclopentadienyltitanium trichloride, pentamethylcyclopentadienyltitanium trichloride, cyclopentadienylmethoxyltitanium dichloride, cyclopentadienyldimethoxytitanium chloride, pentamethylcyclopentadienylmethoxytitanium dichloride, cyclopentadienyltribenzyltitanium, pentamethylcyclopentadienylmethyldiethoxytitanium, indenyltitanium trichloride, indenyltitanium trimethoxide, indenyltitanium triethoxide, indenyltrimethyltitanium, indenyltribenzyltitanium, (tert-butylamide)dimethyl(tetramethyl η 5 -cyclopentadienyl)silanetitanium dichloride, (tert-butylamide)dimethyl(tetramethyl η 5 -cyclopentadienyl)silanetitanium and (tert-butylamide)dimethyl(tetramethyl η 5 -cyclopentadienyl)silanetitanium dimethoxide.
Of these titanium compounds, a compound not containing a halogen atom is preferred and a titanium compound having one π electron type ligand is particularly desirable.
Furthermore, a condensed titanium compound represented by the general formula (VI) may be used as the titanium compound. ##STR1## wherein R 9 and R 10 each represent a halogen atom, an alkoxyl group having 1 to 20 carbon atoms or an acyloxyl group; and k is an integer from 2 to 20.
Furthermore, the above titanium compounds may be used in the form of a complex formed with an ester, an ether or the like.
The trivalent titanium compound represented by the formula (VI) typically includes a trihalogenated titanium such as titanium trichloride; and a cyclopentadienyltitanium compound such as cyclopentadienyltitanium dichloride, and also those obtained by reducing a tetravalent titanium compound. These trivalent titanium compounds may be used in the form of a complex formed with an ester, an ether or the like.
In addition, examples of the zirconium compound used as the transition metal compound include tetrabenzylzirconium, zirconium tetraethoxide, zirconium tetrabutoxide, bisindenylzirconium dichloride, triisopropoxyzirconium chloride, zirconium benzyldichloride and tributoxyzirconium chloride. Examples of the hafnium compound include tetrabenzylhafnium, hafnium tetraethoxide and hafnium tetrabutoxide. Examples of the vanadium compound include vanadyl bisacetylacetonato, vanadyl triacetylacetonato, vanadyl triethoxide and vanadyl tripropoxide. Of these transition metal compounds, the titanium compounds are particularly suitable.
Aside from the foregoing, the transition metal compounds constituting the component (a) include the transition metal compound with two ligands having conjugated π electrons, for example, at least one compound selected from the group consisting of the transition metal compounds represented by the general formula:
M.sup.1 R.sup.11 R.sup.12 R.sup.13 R.sup.14 (VII)
wherein M 1 is titanium, zirconium or hafnium; R 11 and R 12 are each a cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group or fluorenyl group and R 13 and R 14 are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, an amino group or thioalkoxyl group having 1 to 20 carbon atoms, but R 11 and R 12 may be each crosslinked by a hydrocarbon group having 1 to 5 carbon atoms, alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms or germanium-containing hydrocarbon group having 1 to 20 carbon atoms and 1 to 5 germanium atoms.
In more detail, each of R 11 and R 12 in the general formula (VII) designates a cyclopentadienyl group, substituted cyclopentadienyl group, more specifically, methylcyclopentadienyl group; 1,3-dimethylcyclopentadienyl group; 1,2,4-trimethylcyclopentadienyl group; 1,2,3,4-tetramethylcyclopentadienyl group; pentamethylcyclopentadienyl group; trimethylsilylcyclopentadienyl group; 1,3-di(trimethylsilyl)cyclopentadienyl group; 1,2,4-tri(trimethylsilyl)cyclopentadienyl group; tert-butylcyclopentadienyl group; 1,3-di(tert-butyl)cyclopentadienyl group; 1,2,4-tri(tert-butyl)cyclopentadienyl group or the like, indenyl group, substituted indenyl group, more specifically, methylindenyl group; dimethylindenyl group; trimethylindenyl group or the like, fluorenyl group, or substituted fluorenyl group such as methylfluorenyl group, and may be the same or different and crosslinked by an alkylidene group having 1 to 5 carbon atoms, more specifically, methine group; ethylidene group; propylidene group; dimethylcarbyl group or the like, or an alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms, more specifically, dimethylsilyl group; diethylsilyl group; dibenzylsilyl group or the like. Each of R 13 and R 14 independently indicates, as described above but more specifically, a hydrogen atom; an alkyl group having 1 to 20 carbon atoms such as methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, octyl group or 2-ethylhexyl group; an aryl group having 6 to 20 carbon atoms such as phenyl group or naphthyl group; an arylalkyl group having 7 to 20 carbon atoms such as benzyl group; an alkoxyl group having 1 to 20 carbon atoms such as methoxyl group, ethoxyl group, propoxyl group, butoxyl group, amyloxyl group, hexyloxyl group, octyloxyl group or 2-ethylhexyloxyl group; an aryloxyl group having 6 to 20 carbon atoms such as phenoxyl group; an amino group; or a thioalkoxyl group having 1 to 20 carbon atoms.
Specific examples of the transition metal compounds represented by the general formula (VII) wherein M 1 is titanium include bis(cyclopentadienyl)dimethyltitanium; bis(cyclopentadienyl)diethyltitanium; bis(cyclopentadienyl)dipropyltitanium; bis(cyclopentadienyl)dibutyltitanium; bis(methylcyclopentadienyl)dimethyltitanium; bis(tert-butylcyclopentadienyl)dimethyltitanium; bis(1,3-dimethylcyclopentadienyl)dimethyltitanium; bis(1,3-di-tert-butylcyclopentadienyl)dimethyltitanium; bis(1,2,4-trimethylcyclopentadienyl)dimethyltitanium; bis(1,2,3,4-tetramethylcyclopentadienyl)dimethyltitanium; bis(cyclopentadienyl)dimethyltitanium; bis(trimethylsilylcyclopentadienyl)dimethyltitanium; bis(1,3-di(trimethylsilyl)cyclopentadienyl)dimethyltitanium; bis(1,2,4-tris(trimethylsilyl)cyclopentadienyl)dimethyltitanium; bis(indenyl)dimethyltitanium; bis(fluorenyl)dimethyltitanium; methylenebis(cyclopentadienyl)dimethyltitanium; ethylidenebis(cyclopentadienyl)dimethyltitanium; methylenebis(2,3,4,5-tetramethylcyclopentadienyl)dimethyltitanium; ethylidenebis(2,3,4,5-tetramethylcyclopentadienyl)dimethyltitanium; dimethylsilylbis(2,3,4,5-tetramethylcyclopentadienyl)dimethyltitanium; methylenebisindenyldimethyltitanium; ethylidenebisindenyldimethyltitanium; dimethylsilylbisindenyldimethyltitanium; methylenebisfluorenyldimethyltitanium; ethylidenebisfluorenyldimethyltitanium; dimethylsilylbisfluorenyldimethyltitanium; methylene(tert-butylcyclopentadienyl)(cyclopentadienyl)dimethyltitanium; methylene(cyclopentadienyl)(indenyl)dimethyltitanium; ethylidene(cyclopentadienyl)(indenyl)dimethyltitanium; dimethylsilyl(cyclopentadienyl)(indenyl)dimethyltitanium; methylene(cyclopentadienyl)(fluorenyl)dimethyltitanium; ethylidene(cyclopentadienyl)(fluorenyl)dimethyltitanium; dimethylsilyl(cyclopentadienyl)(fluorenyl)dimethyltitanium; methylene(indenyl)(fluorenyl)dimethyltitanium; ethylidene(indenyl)(fluorenyl)dimethyltitanium; dimethylsilyl(indenyl)(fluorenyl)dimethyltitanium; bis(cyclopentadienyl)dibenzyltitanium; bis(tert-butylcyclopentadienyl)dibenzyltitanium; bis(methylcyclopentadienyl)dibenzyltitanium; bis(1,3-dimethylcyclopentadienyl)dibenzyltitanium; bis(1,2,4-trimethylcyclopentadienyl)dibenzyltitanium; bis(1,2,3,4-tetramethylcyclopentadienyl)dibenzyltitanium; bis(pentamethylcyclopentadienyl)dibenzyltitanium; bis(trimethylsilylcyclopentadienyl)dibenzyltitanium; bis 1,3-di-(trimethylsilyl)cyclopentadienyl!dibenzyltitanium; bis 1,2,4-tris(trimethylsilyl)cyclopentadienyl!dibenzyltitanium; bis(indenyl)dibenzyltitanium; bis(fluorenyl)dibenzyltitanium; methylenebis(cyclopentadienyl)dibenzyltitanium; ethylidenebis(cyclopentadienyl)dibenzyltitanium; methylenebis(2,3,4,5-tetramethylcyclopentadienyl)dibenzyltitanium; ethylidenebis(2,3,4,5-tetramethylcyclopentadienyl)dibenzyltitanium; dimethylsilylbis(2,3,4,5-tetramethylcyclopentadienyl)dibenzyltitanium; methylenebis(indenyl)dibenzyltitanium; ethylidenebis(indenyl)dibenzyltitanium; dimethylsilylbis(indenyl)dibenzyltitanium; methylenebis(fluorenyl)dibenzyltitanium; ethylidenebis(fluorenyl)dibenzyltitanium; dimethylsilylbis(fluorenyl)dibenzyltitanium; methylene(cyclopentadienyl)(indenyl)dibenzyltitanium; ethylidene(cyclopentadienyl)(indenyl)dibenzyltitanium; dimethylsilyl(cyclopentadienyl)(indenyl)dibenzyltitanium; methylene(cyclopentadienyl)(fluorenyl)dibenzyltitanium; ethylidene(cyclopentadienyl)(fluorenyl)dibenzyltitanium; dimethylsilyl(cyclopentadienyl)(fluorenyl)dibenzyltitanium; methylene(indenyl)(fluorenyl)dibenzyltitanium; ethylidene(indenyl)(fluorenyl)dibenzyltitanium; dimethylsilyl(indenyl)(fluorenyl)dibenzyltitanium; biscyclopentadienyltitanium dimethoxide; biscyclopentadienyltitanium diethoxide; biscyclopentadienyltitanium dipropoxide; biscyclopentadienyltitanium dibutoxide; biscyclopentadienyltitanium dipheoxide; bis(methylcyclopentadienyl)titanium dimethoxide; bis(1,3-dimethylcyclopentadienyl)titanium dimethoxide; bis(1,2,4-trimethylcyclopentadienyl)titanium dimethoxide; bis(1,2,3,4-tetramethylcyclopentadienyl)titanium dimethoxide; bispentamethylcyclopentadienyltitanium dimethoxide; bis(trimethylsilylcyclopentadienyl)titanium dimethoxide; bis- 1,3-di(trimethylsilyl)cyclopentadienyl!titanium dimethoxide; bis 1,2,4-tri(trimethylsilyl)cyclopentadienyl! titanium dimethoxide; bisindenyltitanium dimethoxide; bisfluorenyltitanium dimethoxide; methylenebiscyclopentadienyltitanium dimethoxide; ethylidenebiscyclopentadienyltitanium dimethoxide; methylenebis(2,3,4,5-tetramethylcyclopentadienyl)titanium dimethoxide; ethylidenebis(2,3,4,5-tetramethylcyclopentadienyl)titanium dimethoxide; dimethylsilylenebis(2,3,4,5-tetramethylcyclopentadienyl)titanium dimethoxide; methylenebisindenyltitanium dimethoxide; methylenebis(methylindenyl)titanium dimethoxide; ethylidenebisindenyltitanium dimethoxide; dimethylsilylbisindenyltitanium dimethoxide; methylenebisfluorenyltitanium dimethoxide; methylenebis(methylfluorenyl)titanium dimethoxide; ethylidenebisfluorenyltitanium dimethoxide; dimethylsilylbisfluorenyltitanium dimethoxide; methylene(cyclopentadienyl)(indenyl)titanium dimethoxide; ethylidene(cyclopentadienyl)(indenyl)titanium dimethoxide; dimethylsilyl(cyclopentadienyl)(indenyl)titanium dimethoxide; methylene(cyclopentadienyl)(fluorenyl)titanium dimethoxide; ethylidene(cyclopentadienyl)(fluorenyl)titanium dimethoxide; dimethylsilyl(cyclopentadienyl)(fluorenyl)titanium dimethoxide; methylene(indenyl)(fluorenyl)titanium dimethoxide; ethylidene(indenyl)(fluorenyl)titanium dimethoxide; and dimethylsilyl(indenyl)(fluorenyl)titanium dimethoxide.
Examples of the transition metal compounds represented by the formula (VII) wherein M 1 is zirconium include ethylidenebiscyclopentadienylzirconium dimethoxide and dimethylsilylbiscyclopentadienylzirconium dimethoxide. Examples of the hafnium compounds according to the general formula (VII) include ethylidenebiscyclopentadienylhafnium dimethoxide, dimethylsilylbiscyclopentadienylhafnium dimethoxide, etc. Particularly desirable transition metal compounds among them are titanium compounds. In addition to the combinations of the above, the compound may be a bidentate coordination complex compound such as 2,2'-thiobis-(4-methyl-6-tert-butylphenyl)titanium diisopropoxide; 2,2'-thiobis(4-methyl-6-tert-butylphenyl)titanium dimethoxide or the like.
As the transition metal compound of the component (a) usable in the present invention, there is available at least one compound selected from the group consisting of the transition metal compounds having the constitution represented by the general formula (VIII)
R'MX'.sub.p-1 L.sup.1.sub.q (VIII)
wherein R is, as a π ligand, a fused polycyclic cyclopentadienyl group wherein at least one of many-membered rings to which cyclopentadienyl groups are fusedly bonded is a saturated ring, M is as previously defined, X' is a σ ligand, a plurality of X' may be the same or different and bonded to each other through an arbitrary group, L 1 is a Lewis base, p is the valency of M, q is 0, 1 or 2 and when L 1 is plural, each L 1 may be the same or different. The above-mentioned fused polycyclic cyclopentadienyl group is exemplified by that selected from those represented by any one of the general formulae (IX) to (XI) ##STR2## wherein R 15 , R 16 and R 17 are each a hydrogen atom, a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, an aryloxyl group having 6 to 20 carbon atoms, a thioalkoxyl group having 1 to 20 carbon atoms, a thioaryloxyl group having 6 to 20 carbon atoms, an amino group, an amide group, a carboxyl group or an alkylsilyl group and may be the same as or different from each other; and w, x, y and z are each an integer of 1 or greater. Of these, 4,5,6,7-tetrahydroindenyl group is preferable from the viewpoint of catalytic activity and the ease of its synthesis.
Specific examples of R' include 4,5,6,7-tetrahydroindenyl group; 1-methyl-4,5,6,7-tetrahydroindenyl group; 2-methyl-4,5,6,7-tetrahydroindenyl group; 1,2-dimethyl-4,5,6,7-tetrahydroindenyl group; 1,3-dimethyl-4,5,6,7-tetrahydroindenyl group; 1,2,3-trimethyl-4,5,6,7-tetrahydroindenyl group; 1,2,3,4,5,6,7-heptamethyl-4,5,6,7-tetrahydroindenyl group; 1,2,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyl group; 1,3,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyl group; octahydrofluorenyl group; 1,2,3,4-tetrahydrofluorenyl group; 9-methyl-1,2,3,4-tetrahydrofluorenyl group; and 9-methyl-octahydrofluorenyl group.
M is a Group 3 to 6 metal or a lanthanoids metal and exemplified by titanium, zirconium, hafnium, lanthanoids, niobium and tantalum. Of these titanium is preferable from the viewpoint of catalytic activity. X' is a σ ligand and is exemplified by a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, an aryloxyl group having 6 to 20 carbon atoms, a thioalkoxyl group having 1 to 20 carbon atoms, a thioaryloxyl group having 6 to 20 carbon atoms, an amino group, an amide group, a carboxyl group or an alkylsilyl group, and a plurality of X' may be the same or different and bonded to each other through an arbitrary group. Further, X' is specifically exemplified by hydrogen atom, chlorine atom, bromine atom, iodine atom, methyl group, benzyl group, phenyl group, trimethylsilylmethyl group, methoxy group, ethoxy group, phenoxy group, thiomethoxy group, thiophenoxy group, dimethylamino group and diisopropylamino group. L 1 is a Lewis base, p is the valency of M and q is 0, 1 or 2.
As the transition metal compound represented by the general formula (VIII), there can preferably be employed a compound comprising R' and X' each arbitrarily selected from the above-exemplified groups.
The transition metal compound represented by the general formula (I) is specifically exemplified by but not limited to 4,5,6,7-tetrahydroindenyltitanium trichloride; 4,5,6,7-tetrahydroindenyltrimethyltitanium; 4,5,6,7-tetrahydroindenyltribenzyltitanium; 4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1-methyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 1-methyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1-methyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1-methyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 2-methyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 2-methyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 2-methyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 2-methyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1,2-dimethyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 1,2-dimethyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1,2-dimethyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1,2-dimethyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1,3-dimethyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 1,3-dimethyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1,3-dimethyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1,3-dimethyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1,2,3-trimethyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 1,2,3-trimethyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1,2,3-trimethyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1,2,3-trimethyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1,2,3,4,5,6,7-heptamethyl-4,5,6,7-tetrahydroindenyltitanium trichlorde; 1,2,3,4,5,6,7-heptamethyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1,2,3,4,5,6,7-heptamethyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1,2,3,4,5,6,7-heptamethyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1,2,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltitanium trichlorde; 1,2,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1,2,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1,2,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; 1,3,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 1,3,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltitanium trichloride; 1,3,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltrimethyltitanium; 1,3,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltribenzyltitanium; 1,3,4,5,6,7-hexamethyl-4,5,6,7-tetrahydroindenyltitanium trimethoxide; octahydrofluorenyltitanium trichloride; octahydrofluorenyltrimethyltitanium; octahydrofluorenyltribenzyltitanium; octahydrofluorenyltitanium trimethoxide; 1,2,3,4-tetrahydrofluorenyltitanium trichloride; 1,2,3,4-tetrahydrofluorenyltrimethyltitanium; 1,2,3,4-tetrahydrofluorenyltribenzyltitanium; 1,2,3,4-tetrahydrofluorenyltitanium trimethoxide; 9-methyl-1,2,3,4-tetrahydrofluorenyltitanium trichloride; 9-methyl-1,2,3,4-tetrahydrofluorenyltrimethyltitanium; 9-methyl-1,2,3,4-tetrahydrofluorenyltribenzyltitanium; 9-methyl-1,2,3,4-tetrahydrofluorenyltitanium trimethoxide; 9-methyl octahydrofluorenyltitanium trichloride; 9-methyloctahydrofluorenyltrimethyltitanium; 9-methyloctahydrofluorenyltribenzyltitanium; 9-methyloctahydrofluorenyltitanium trimethoxide; any of the above-mentioned compounds in which the titanium is replaced with zirconium or hafnium and a similar compound in which the transition metal element belongs to an other series or lanthnoids. Of these the titanium compounds are preferable from the viewpoint of catalytic activity.
There are available various coordination complex compounds comprising an anion in which a plurality of radicals are bonded to a metal to be used as the component (b) in the present invention, and there is preferably usable such a coordination complex compound as represented by the following general formula (XII) or (XIII):
( L.sup.1 --H!.sup.g+).sub.h ( M.sup.2 X.sup.1 X.sup.2 - - - X.sup.n !.sup.(n-m)-).sub.i (XII)
or
( L.sup.2 !.sup.g+).sub.q ( M.sup.3 X.sup.1 X.sup.2 - - - X.sup.n !.sup.(n-m)-).sub.i (XIII)
wherein L 2 is M 4 , R 18 R 19 M 5 or R 20 3 C as hereinafter described; L 1 is a Lewis base; M 2 and M 3 are each a metal selected from Groups 5 to 15 of the Periodic Table; M 4 is a metal selected from Groups 8 to 12 of the Periodic Table; M 5 is a metal selected from Groups 8 to 10 of the Periodic Table; X 1 to X n are each a hydrogen atom, a dialkylamino group, an alkoxyl group, an aryloxyl group, an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkylaryl group or an arylalkyl group, each having 6 to 20 carbon atoms, a substituted alkyl group, an organometalloid group or a halogen atom; R 18 and R 19 are each a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a fluorenyl group; R 20 is an alkyl group; m is the valency of each of M 2 and M 3 , indicating an integer of 1 to 7; n is an integer of 2 to 8; g is the ion valency of each of L 1 --H! and L 2 !, indicating an integer of 1 to 7; h is an integer of 1 or more; and j=h×g/(n-m).
Specific examples of M 2 and M 3 include B, Al, Si, P, As, Sb, etc. in the form of atom; those of M 4 include Ag, Cu, etc. in the form of atom; and those of M 5 include Fe, Co, Ni, etc. in the form of atom. Specific examples of X 1 to X n include a dialkylamino group such as dimethylamino and diethylamino; an alkoxyl group such as methoxyl, ethoxyl and n-butoxyl; an aryloxyl group such as phenoxyl, 2,6-dimethylphenoxyl and naphthyloxyl; an alkyl group having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, n-octyl and 2-ethylhexyl; an aryl group, an alkylaryl group or an arylalkyl group each having 6 to 20 carbon atoms, such as phenyl, p-tolyl, benzyl, pentafluorophenyl, 3,5-di(trifluoromethyl)phenyl, 4-tertbutylphenyl, 2,6-dimethylphenyl, 3,5-dimethylphenyl, 2,4dimethylphenyl and 1,2-dimethylphenyl; a halogen atom such as F, Cl, Br and I; and an organometalloid such as pentamethylantimony group, trimethylsilyl group, trimethylgermyl group, diphenylarsine group, dicyclohexylantimony group and diphenylboron group. Specific examples of substituted cyclopentadienyl group represented by any of R 18 and R 19 include methylcyclopentadienyl, butylcyclopentadienyl and pentamethylcyclopentadienyl.
Specific examples of the anion in which a plurality of radicals are bonded to a metal include B(C 6 F 5 ) 4 - , B(C 6 HF 4 ) 4 - , B(C 6 H 2 F 3 ) 4 - , B(C 6 H 3 F 2 ) 4 - , B(C 6 H 4 F) 4 - , B(C 6 CF 3 F 4 ) 4 - , B(C 6 F 5 ) 4 - , BF 4 - , PF 6 - , P(C 6 F 5 ) 6 - and Al(C 6 HF 4 ) 4 -.
Specific examples of the metallic cation include CpFe + , (MeCp) 2 Fe + , (tBuCp) 2 Fe + , (Me 2 Cp) 2 Fe + , (Me 3 CP) 2 Fe + , (Me 4 Cp) 2 Fe + , (Me 5 Cp) 2 Fe + , Ag + , Na + and Li + , a nitrogen atom-containing compound such as pyridinium, 2,4-dinitro-N,N-diethylanilinium, diphenylammonium, p-nitroanilinium, 2,5-dichloroaniline, p-nitro-N,N-dimethylanilinum, quinolinium, N,N-dimethylanilinum and N,N-diethylanilinium; a carbenium compound such as triphenylcarbenium, tri(4-methylphenyl)carbenium and tri(4-methoxyphenyl)carbenium; an alkylphosphonium ion such as CH 3 PH 3 + , C 2 H 5 PH 3 + , C 3 H 7 PH 3 + , (CH 3 ) 2 PH 2 + , (C 2 H 5 ) 2 PH 2 + , (C 3 H 7 ) 2 PH 2 + , (CH 3 ) 3 PH + , (C 2 H 5 ) 3 PH + , (C 3 H 7 ) 3 PH + , (CF 3 ) 3 PH + , (CH 3 ) 4 P + , (C 2 H 5 ) 4 P + and (C 3 H 7 ) 4 P + ; and an arylphosphonium ion such as C 6 H 5 PH 3 + , (C 6 H 5 ) 2 PH 2 + , (C 6 H 5 ) 3 PH + , (C 6 H 5 ) 4 P + , (C 2 H 5 ) 2 (C 6 H 5 )PH + , (CH 3 )(C 6 H 5 )PH 2 + , (CH 3 ) 2 (C 6 H 5 )PH + and (C 2 H 5 ) 2 (C 6 H 5 ) 2 P + .
Among the compounds represented by the general formula (XII) or (XIII), specific examples of preferably usable compounds include, as the compound of the general formula (XII), triethylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, trimethylammonium tetraphenylborate, triethylammonium tetra(pentafluorophenyl)borate, tri(n-butyl)ammonium tetra(pentafluorophenyl)borate, triethylammonium hexafluoroarsenate, pyridinium tetra(pentafluorophenyl)borate, pyrrolinium tetra(pentafluorophenyl)borate, N,N-dimethylanilinium tetra(pentafluorophenyl)borate and methyldiphenylammonium tetra(pentafluorophenyl)borate, and as the compound of the general formula (XIII), ferrocenium tetraphenylborate, dimethylferrocenium tetra(pentafluorophenyl)borate, ferrocenium tetra(pentafluorophenyl)borate, decamethylferrocenium tetra(pentafluorophenyl)borate, acetylferrocenium tetra(pentafluorophenyl)borate, formylferrocenium tetra(pentafluorophenyl)borate, cyanoferrocenium tetra(pentafluorophenyl)borate, silver tetraphenylborate, silver tetra(pentafluorophenyl)borate, trityl tetraphenylborate, trityl tetra(pentafluorophenyl)borate, silver hexafluoroarsenate, silver hexafluoroantimonate and silver tetrafluoroborate.
Methylaluminoxane may be used as the component (b) in addition to or in place of the coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a cation.
There are available various alkylating agents as the component (c), which are exemplified by the aluminum compound having an alkyl group represented by the general formula (XV)
R.sup.21.sub.m' Al (OR.sup.22).sub.n' X.sub.3-m'-n' (XV)
wherein R 21 and R 22 are each an alkyl group having 1 to 8, preferably 1 to 4 carbon atoms, X is a hydrogen atom or a halogen atom, m' satisfies the relation 0<m'≦3, desirably m'=2 or 3, most desirably m'=3, and n' satisfies the relation 0≦n'<3, desirably n'=0 or 1; the magnesium compound having an alkyl group represented by the general formula (XVI)
R.sup.21.sub.2 Mg (XVI)
wherein R 21 is as previously defined;
the zinc compound having an alkyl group represented by the general formula (XVII)
R.sup.21.sub.2 Zn (XVII)
wherein R 21 is as previously defined; and the like.
The aforesaid compounds each having an alkyl group are preferably aluminum compounds each having an alkyl group, more desirably trialkylaluminum compounds and dialkylaluminum compounds, and specifically exemplified by trialkylaluminum such as trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum and tri-tert-butylaluminum; dialkylaluminum halide such as dimethylaluminum chloride, diethylaluminum chloride, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, diisobutylaluminum chloride and di-tert-butylaluminum chloride; dialkylaluminum alkoxide such as dimethylaluminum methoxide and dimethylaluminum ethoxide; dialkylaluminum hydride such as dimethylaluminum hydride, diethylaluminum hydride and diisobutylaluminum hydride, dialkylmagnesium such as dimethylmagnesium, diethylmagnesium, di-n-propylmagnesium and diisopropylmagnesium; and dialkylzinc such as dimethylzinc, diethylzinc, di-n-propylethylzinc and diisopropylzinc, and the like.
As described hereinbefore, the process according to the present invention comprises polymerizing a styrenic monomer by the use of the catalyst composed of the components (a), (b) and (c) and incorporating in the polymerization system, a (d) reaction product between a straight chain alkylaluminum having at least two carbon atoms in the alkyl group as represented by the general formula (XVIII) and water.
R.sup.0.sub.3 Al (XVIII)
wherein R 0 is a straight chain alkyl group having 2 to 10, preferably 2 to 6 carbon atoms. Specific examples of such alkylaluminum include triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, tri-n-pentylaluminum, tri-n-hexylaluminum and tri-n-heptylaluminum.
The water to be reacted with the straight chain alkylaluminum may be any of ice, water, steam, an organic solvent saturated with water and water of crystallization.
The reaction product between such a straight chain alkylaluminum and water to be used in the present invention is obtained by reacting the above-mentioned straight chain alkylaluminum with water in a molar ratio of 1:(1 to 2) at a temperature of -78° to 100° C. in a organic solvent without active hydrogen atom, and is represented by the general formula (XIX) or (XX) ##STR3## wherein R 0 is as previously defined and n is an integer from 1 to 20. Specific examples of these compounds include ethylaluminoxane, propylaluminoxane, butylaluminoxane, pentylaluminoxane, hexylaluminoxane and heptylaluminoxane.
The above-mentioned compound represented by the general formula (XIX) or (XX) has preferably n of 1 to 5 and may be used alone or in combination with at least one other one.
In the case of carrying out the process of the present invention, the aforesaid components (a), (b), (c) and (d) may be added, separately one by one, to the monomer to be polymerized, or may be premixed with a solvent (aromatic hydrocarbon such as toluene, and ethylbenzene or aliphatic hydrocarbon such as hexane and heptane) prior to mixing with the monomer, in which the components (c) and (d) may totally or partly be added to the monomer.
The addition of the aforesaid components (a), (b), (c) and (d) to the monomer can be carried out at a temperature of 0° to 100° C., needless to say, at a polymerization temperature.
The above-described catalyst along with the chain transfer agent exhibit a high activity in the production of a styrenic polymer having a high degree of syndiotactic configuration.
The molecular weight of the resultant polymer can be lowered by the addition of the component (d), but the amount thereof to be added is not specifically limited, since it varies depending on the type of each of the components (a), (b), (c) and (d), the monomer species and polymerization conditions such as polymerization temperature.
In the production of a styrenic polymer by the process according to the present invention, a styrenic monomer or monomers or a styrenic derivative or derivatives is homopolymerized or are copolymerized in the present of a catalyst composed mainly of the components (a), (b) and (c) and chain transfer agent of the component (d).
As the styrenic monomer, there is preferably used a compound represented by the general formula (XXI) ##STR4## wherein R 23 is hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms, m' is an integer from 1 to 3 and, when m' is 2 or greater, a plurality of R 23 may be the same or different.
Examples of the compound of the general formula (XXI) include styrene; alkylstyrenes such as p-methylstyrene; m-methylstyrene; o-methylstyrene; 2,4-dimethylstyrene; 2,5-dimethylstyrene; 3,4-dimethylstyrene; 3,5-dimethylstyrene; and p-tertiary-butylstyrene; polyvinylbenzenes such as p-divinylbenzene; m-divinylbenzene; and trivinylbenzene; halogenated styrenes such as p-chlorostyrene; m-chlorostyrene; o-chlorostyrene; p-bromostyrene; m-bromostyrene; o-bromostyrene; p-fluorostyrene; m-fluorostyrene; o-fluorostyrene and o-methyl-p-fluorostyrene; alkoxystyrenes such as methoxystyrene; ethoxystyrene; and tert-butoxystyrene; and a mixture of at least two of them.
The polymerization of the styrenic monomer or monomers may be carried out by means of bulk polymerization or solution polymerization by the use of an aliphatic hydrocarbon solvent such as pentane, hexane or heptane, an alicyclic hydrocarbon solvent such as cyclohexane or an aromatic hydrocarbon solvent such as benzene, toluene or xylene. The polymerization temperature is not specifically limited, but is usually in the range of 20° to 120° C., preferably 20° to 90° C. In addition, the polymerization reaction may be carried out in the presence of hydrogen in order to modify the molecular weight of the styrenic polymer to be produced.
The styrenic polymer thus obtained possesses a high degree of syndiotactic configuration in its polymerization chain of the styrenic monomer. Here, the styrenic polymer having a high degree of syndiotactic configuration in its polymerization chain of the styrenic monomer means that its stereochemical structure is mainly of syndiotactic configuration, i.e. the stereostructure in which phenyl groups or substituted phenyl group as side chains are located alternately at opposite directions relative to the main chain consisting of carbon-carbon bonds. Tacticity is quantitatively determined by the nuclear magnetic resonance method ( 13 C-NMR method) using carbon isotope. The tacticity as determined by the 13 C-NMR method can be indicated in terms of proportions of structural units continuously connected to each other, i.e., a diad in which two structural units are connected to each other, a triad in which three structural units are connected to each other and a pentad in which five structural unit are connected to each other. "-The styrenic polymers having a high degree of syndiotactic configuration" as mentioned in the present invention means polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(alkoxystyrene), poly(vinylbenzoate), the mixtures thereof, and copolymers containing the above polymers as main components, having such a syndiotacticity that the proportion of racemic diad is at least 75%, preferably at least 85%, or the proportion of racemic pentad is at least 30%, preferably at least 50%. The poly(alkylstyrene) includes poly(methylstyrene), poly(ethylstyrene) poly(isopropylstyrene), poly(tert-butylstyrene), etc., poly(halogenated styrene) includes poly(chlorostyrene), poly(bromostyrene), and poly(fluorostyrene), etc. The poly(alkoxystyrene) includes poly(methoxystyrene), poly(ethoxystyrene), etc. The most desirable styrenic polymers are polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene), and the copolymer of styrene and p-methylstyrene.
As described hereinbefore, the process according to the present invention makes it possible to attain a high activity in the production of a styrenic polymer having a high degree of syndiotactic configuration, decrease the amount of the residual metals in the resultant styrenic polymer without deterioration of the catalytic activity by the use of a reaction product between the specific straight chain alkylaluminum and water, and at the same time, to simplify the production process of the styrenic polymer and curtail the production cost thereof.
In the following, the present invention will be described in more detail with reference to comparative examples and examples, which however, shall not be construed to limit the present invention thereto.
EXAMPLE 1
(1) Synthesis of ethylaluminoxane
In a 5 liter (hereinafter abbreviated to "L") vessel which had been dried and purged with nitrogen was placed 178 milliliter (hereinafter abbreviated to "mL") of 0.5 mol/L solution of triethylaluminum in 112 mL of toluene. To the resultant mixture was gradually added dropwise under sufficient stirring at room temperature, 1.67 L solution in toluene (H 2 O; 430.7×10 -6 g/mL) which had been adjusted in water content by means of ion-exchanged water. After the completion of the dropwise addition, the toluene was distilled away to form 8.5 g of product.
(2) Polymerization of styrene
In a 50 mL vessel which had been dried and purged with nitrogen were successively placed 0.4 mL of 2 moles/L of triisobutylaluminum in 39.3 mL of toluene, 64 mg of dimethylanilinium tetra(pentafluorophenyl)borate, and 0.32 mL of 250 mmol of pentamethylcyclopentadienyltitanium trimethoxide to prepare a preliminary mixed catalyst. In a 30 mL vessel which had been dried and purged with nitrogen were placed 10 mL of styrene and 45 μL of 0.28 mol/L of ethylaluminoxane with heating to 70° C. and 250 μL of the preliminary mixed catalyst as prepared above to polymerize the styrene for 1 hour. After the completion of the reaction, the reaction product was dried to afford 2.99 g of a polymer. The resultant polymer was cut into slices of at most 1 mm in thickness, which were subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP (MEK-insoluble portion). As a result, objective SPS having a molecular weight of 310,000 was obtained in a yield of 2.83 g with a raffinate (MIP) rate of 94.8% and an activity for SPS of 118 kg/g-Ti.
EXAMPLE 2
The procedure in Example 1 (2) was repeated to obtain 2.87 g of a polymer except that the addition amount of 0.28 mol/L of ethylaluminoxane was set on 90 μL in place of 45 μL. The resultant polymer was subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP. As a result, objective SPS having a molecular weight of 240,000 was obtained in a yield of 2.80 g with a raffinate (MIP) rate of 97.6% and an activity for SPS of 117 kg/g-Ti.
EXAMPLE 3
The procedure in Example 1 (2) was repeated to obtain 2.87 g of a polymer except that there was used n-butylaluminoxane which had been prepared in the same manner as in Example 1 (1) in place of ethylaluminoxane. The resultant polymer was subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP. As a result, objective SPS having a molecular weight of 350,000 was obtained in a yield of 2.81 g with a raffinate (MIP) rate of 97.9% and an activity for SPS of 117 kg/g-Ti.
EXAMPLE 4
The procedure in Example 1 (2) was repeated to obtain a polymer except that there was used n-propylaluminoxane which had been prepared in the same manner as in Example 1 (1) in place of ethylaluminoxane. The resultant polymer was subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP. As a result, objective SPS having a molecular weight of 340,000 was obtained with a raffinate (MIP) rate of 95% and an activity for SPS of 120 kg/g-Ti.
EXAMPLE 5
The procedure in Example 1 (2) was repeated to obtain a polymer except that there was used ferrocenium tetra(pentafluorenyl)borate in place of dimethylanilinium tetra(pentafluorenyl)borate. The resultant polymer was subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP. As a result, objective SPS having a molecular weight of 320,000 was obtained with a raffinate (MIP) rate of 95% and an activity for SPS of 122 kg/g-Ti.
EXAMPLE 6
The procedure in Example 1 (2) was repeated to obtain a polymer except that there was used tri-n-butylaluminum in place of triisobutylaluminum. The resultant polymer was subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP. As a result, objective SPS having a molecular weight of 310,000 was obtained with a raffinate (MIP) rate of 95% and an activity for SPS of 119 kg/g-Ti.
Comparative Example 1
The procedure in Example 1 (2) was repeated to obtain a polymer except that ethylaluminoxane was not used. The resultant polymer was subjected to Soxhlet extraction for 6 hours by the use of methyl ethyl ketone (MEK) as the solvent to produce MIP. As a result, objective SPS having a molecular weight of 871,000 was obtained in a yield of 2.69 g with a raffinate (MIP) rate of 95.5% and an activity for SPS of 112 kg/g-Ti.
Example A
The procedure in Example 1 (2) was repeated except that 4.0 mL of 1.6 mol/L of methylaluminoxane solution was used in place of 64 mg of dimethylanilinium tetra(pentafluorophenyl)borate. As a result, objective SPS having a molecular weight of 340,000 was obtained in a yield of 3.25 g with a raffinate (MIP) rate of 96.4% and an activity for SPS of 138 kg/g-Ti.
Example B
The procedure in Example 1 (2) was repeated except that 0.5 mmol of butylethylmagnesium was used in place of 0.4 mL of 2 mol/L of triisobutylaluminum and 4.0 mL of 1.6 mol/L of methylaluminoxane solution was used in place of 64 mg of dimethylanilinium tetra(pentafluorophenyl)borate. As a result, objective SPS having a molecular weight of 370,000 was obtained in a yield of 2.25 g with a raffinate (MIP) rate of 94.4% and an activity for SPS of 93 kg/g-Ti.
Comparative Example A
The procedure in Example 1 (2) was repeated except that 1.0 mL of 2.0 mol/L of trimethylaluminum solution was used in place of 64 mg of dimethylanilinium tetra (pentafluorophenyl)borate. As a result, objective SPS having a molecular weight of 270,000 was obtained in a yield of 0.95 g with a raffinate (MIP) rate of 90.5% and an activity for SPS of 38 kg/g-Ti.
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There is disclosed a process for producing a styrenic polymer, especially, syndiotactic polystyrene, which comprises polymerizing a styrenic monomer by the use of (a) a transition metal compound, (b) a coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a cation or methylaluminoxane, (c) an alkylating agent (alkyl group-containing aluminum, magnesium or zinc compound) and (d) a reaction product between a straight-chain alkylaluminum having at least two carbon atoms and water (alkylaluminoxane). The above process is capable of simplifying the production process and producing high-performance styrenic polymer having a high degree of syndiotactic configuration in high catalytic activity without deteriorating the catalyst activity, increasing the amounts of residual metals in the objective polymer or leaving the decomposition products of the alkylaluminum therein, thereby curtailing the production cost of the objective polymer.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for preparing biuret polyisocyanate.
BACKGROUND OF THE INVENTION
[0002] Biuret polyisocyanate is widely used in the production of coatings, adhesives, sealants, waterproofing agents, foams, elastomers, fiber processing agents and so on. The preparation method of the aliphatic polyisocyanates having biuret structures has been disclosed in the patent document DE 1101394B published in 1958. Other possible preparation methods are disclosed in the review paper “The synthesis of Aliphatic Polyisocyanates Containing Biuret, isocyanurate or uretdione backbones for use in coating”, J.prakt. Chem, 336, 1994, 185-200, and the advantages and drawbacks of these methods are discussed in the review paper.
[0003] The preparation methods of biuret polyisocyanate can be mainly divided into two categories: the first is a water method, in which urea is produced by the reaction of diisocyanate and excess water or water donors (for example tertiary monoalcohols, formic acid, crystalline hydrate etc.) and carbon dioxide is produced simultaneously, then biuret polyisocyanate is produced by the reaction of urea and excess diisocyanate; the second is a diisocyanate/diamine method, in which urea is produced directly by diisocyanate and insufficient amount of amine (for example primary amine and/or secondary amine), then biuret polyisocyanate is produced by the reaction of urea and excess diisocyanate. As stated in the above mentioned review paper (J.prakt. Chem, 336, 1994, 185-200), a variety of modifications of the above two methods have been developed and described.
[0004] Biuret polyisocyanates prepared by the water method have great monomer stability, i.e. they are hard to break into free diisocyanates, and good tolerance of dilution, i.e. the solution formed by said biuret polyisocyanates and diluents are not likely to be cloudy and generate sediments; and the condition of the preparation process of the water method is relatively mild, and the color number of the obtained products is relative low, thus the method is widely used in manufacturing.
[0005] However, in the preparation of the water method, solid state polyurea is very likely to be produced during the reaction process because of the poor compatibility and the insufficient contact of liquid water and diisocyanates; furthermore, the tail gas produced during the reaction still contains a certain amount of diisocyanates and water vapour, and the water vapour can be reacted with a part of diisocyanate gas, solid state polyurea is also easily produced by such reaction, resulting in the blocking of condensers and exhaust pipes and a loss of a part of diisocyanate materials; when solvents are used in the preparation method, polyurea in the condensate of the tail gas will be condensed and refluxed to the products with the solvents. Thus the products will contain polyurea, which will result in poor homogeneity, high cloudiness and white appearance of the products, thus influencing the property of the products, for example the anti-corrosion of the coatings prepared by such products and so on.
[0006] In the US patent document U.S. Pat. No. 4,028,392A, it is disclosed that in the presence of hydrophilic organic solvents such as trialkyl phosphate and ethylene glycol methyl ether acetate, diisocyanate is reacted with water to produce biuret polyisocyanates. In European patent document EP0259233A, it is disclosed that in the presence of at least one carboxylic acid and/or carboxylic acid anhydride as catalysts, diisocyanate is reacted with water; in said method, it is also disclosed that methyl phosphate and/or ethyl phosphate and alkoxyl alkyl carboxylate can be used simultaneously as solubilizers, to increase the solubility of water in the solution of diisocyanate and the catalyst. In the above two preparation methods, due to the use of a necessary amount of solvents or solvent mixtures, a relative low biuret polyisocyanate space-time yield is obtained compared with the condition that no solvents are used, and the polyurea produced in a tail gas is condensed and refluxed to the products with solvents, resulting in a cloudy product with white appearance obtained after separation. Moreover, devices and energy-consumption are increased and a more complex operation is required due to the use of solvents, thus more complex distillation operation is required to separate solvents.
[0007] In German patent document DE2918739A1, it is disclosed a method for preparing polyisocyanate having biuret structure by the reaction of hexamethylene diisocyanate (HDI) and water, wherein water is mixed with air and/or inert gas in the form of vapour and then is added to the mixed solution of HDI and a catalyst with the temperature of 110-130° C., the reaction is carried out under 150-170° C. The drawback of said method is, as a single reactor is used for the operation of mixing of gas and liquid, the conversion rate of water vapour is not high enough, the tail gas generated during the reaction process produce a large amount of solid polyurea, resulting in the blocking of the device parts, especially the tail gas pipes; meanwhile, the tail gas is not treated, resulting in a great loss of diisocyanate materials.
[0008] In the Chinese patent document CN101475680A, it is disclosed a method of synthesizing hexamethylene diisocyanate biuret by spraying, wherein biuret polyiscyanate is prepared by the reaction of hexamethylene diisocyanate and water that is in the form of fogdrop achieved by the use of high pressure. As water cannot be dispersed timely and sufficiently when liquid drop-like water is reacted with hexamethylene diisocyanate, polyurea is formed unavoidably, thus resulting in highly cloudy products with white appearance obtained after separation.
[0009] In the Chinese patent document CN101072805A, it is disclosed a method for preparing a storage-stable colorless polyisocyanates having biuret groups. A single reactor is used in said method, and water participated in the reaction is in the form of water vapour to solve the problem of water dispersing. Meanwhile, cold hexamethylene diisocyanate is used to wash tail gas, thus decreasing the loss of the material, hexamethylene diisocyanate. However, as a single reactor is used in operation in said method, the conversion rate of water is not high enough, resulting in a large amount of water left in the returning condensate, these water are reacted with diisocyanate to produce polyurea, leading to products with high cloudiness obtained after separation.
[0010] Because the current biuret polyisocyanate preparation methods have many drawbacks, a new biuret polyisocyanate preparation method that will not cause the blocking of the exhaust pipes of condensers during the reaction process and has a low diisocyanate material loss and will produce products with low cloudiness and transparent appearance is required.
SUMMARY OF THE INVENTION
[0011] The present invention aims at overcoming the drawbacks of the prior art technology, and providing a method of producing biuret polyisocyanate that does not cause the blocking of the exhaust pipes of condensers, and has a low diisocyanate material loss and obtains products with low cloudiness, transparent appearance and great application performances.
[0012] In order to achieve the above purpose, the present invention adopt the following technical solutions:
[0013] A method for continuously preparing biuret polyisocyanate, comprising:
[0014] a) a mixed solution of a diisocyanate and a catalyst, and water vapour, in an aerosol form, are continuously reacted in a first reactor; wherein the continuous phase of the aerosol is the water vapour, the dispersed phase is the mixed solution of the diisocyanate and the catalyst;
[0015] b) the product obtained in step a) is brought into a second reactor for a further reaction; a tail gas from the second reactor is condensed and refluxed, and the non-condensable gas is brought into a tail gas treatment system;
[0016] c) the reaction liquid obtained in step b) is further reacted in a third reactor;
[0017] d) a separation of the reaction liquid obtained in step c) is performed for removing monomers, so as to obtain biuret polyisocyanate.
[0018] In the method of the present invention, said diisocyanate is an aliphatic and/or alicyclic diisocyanate, and/or aromatic diisocyanate, i.e. said diisocyanate can be any one of aliphatic, alicyclic or aromatic diisocyanates or the combination thereof.
[0019] Said alicyclic diisocyanate is a diisocyanate comprising at least one alicyclic ring system.
[0020] Said aliphatic diisocycante is a diisocyanate that only comprises straight-chains or branched chains, i.e. compounds without rings, i.e. a diisocyanate without ring structure.
[0021] Suitable diisocyanates are preferably aliphatic and/or alicyclic diioscyanates with 4-20 carbon atoms, or diphenylmethane diisocyanate or toluene diisocyanate.
[0022] One or two or more of tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), octamethylene diiscoyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, derivatives of lysine diisocyanate, tetramethylbenzene dimethylene diisocyanate, 4,4′- or 2,4′-di(cyclohexyl isocyanate)methane (H 12 MDI) and 3-isocyanatomethyl-3,5,5,-trimethylcyclohexy isocyanate (isophorone diisocyanate) are more preferred, one or two or more of HDI, H 12 MDI and isophorone diisocyanate are especially preferred.
[0023] In the method of the present invention, the reaction is carried out preferably under the presence of at least one catalyst.
[0024] Said catalyst can be the OH-acidic compound such as disclosed in the German patent document DE4443885A1. The advantages of these catalysts are their low volatility and thus can be filtered out as salts from reaction mixtures or can be kept in the final products as noninterfering compounds. Another advantage of these compounds is the great catalytic activity of the acids. The OH-acidic compounds that are suitable for the present invention are especially Brnsted acids. Said OH-acidic compounds can be preferably chosen among the following compounds, one or mixtures of more of phosphoric acid, monoalkyl phosphate, dialkyl phosphate, monoaryl phosphate, diaryl phosphate, monocarboxylic acid and dicarboxylic acid. Preferably, said monoalkyl phosphate, dialkyl phosphate, monoaryl phosphate or diaryl phosphate are the aliphatic, branched aliphatic or araliphatic groups there of with 1-30, preferably 4-20 carbon atoms, for example, methyl phosphate, ethyl phosphate, dibutyl phosphate, dihexyl phosphate, 2-ethyl hexyl phosphate, isooctyl phosphate, n-dodecyl phosphate, diethyl phosphate, di-n-propyl phophsate, di-n-butyl phosphate, diisoamyl phosphate, di-n-decyl phosphate, diphenyl phosphate and mixtures thereof. Suitable monocarboxylic acids and dicarboxylic acids are, for example formic acid, acetic acid, propionic acid, butyric acid, neopentanoic acid, stearic acid, naphthenic acid, oxalic acid, malonic acid, succinic acid, adipic acid, benzoic acid, phthalic acid etc. and mixtures thereof. One or two of dibutyl phosphate and propionic acid are more preferred.
[0025] The amount of said catalyst is 0.1-3.0 wt % based on the total amount of the used diisocyanates, the catalysts can be added to the diisocyanates after being dissolved by suitable solvents or after being dispersed or can be added directly to the diisocyanates. It is preferred to add the catalyst directly to the diisocyanates.
[0026] In the method of the present invention, the continuous phase of the aerosol form is the water vapour, the dispersed phase is the mixed solution of the diisocyanate and the catalyst. The droplet size of the dispersed phase in the aerosol form is 0.01-50 μm, preferably 0.5-20 μm, especially preferably 1-5 μm. Said aerosol can be prepared by a mechanical spraying device or an ultrasonic dispersing device.
[0027] It is required for the dispersed phase of the aerosol to possess droplet size that are relatively small and a uniform droplet size distribution, the smaller the droplet size is, the higher the energy of dispersion is required. Too small droplet size is not suitable from an economical prospect; but too large droplet size will cause an unstable colloid, and the specific surface of the liquid droplet will be smaller, the conversion rate of the water vapour will be lower. Upon repeated experiments, it is discovered by the inventor that, within the droplet size range provided in the present invention, the aerosol is relatively stable, and the conversion rate of the water vapour is high and the consumption of energy is relatively low.
[0028] It is suitable to preheat the mixed solution of the diisocyanate and the catalyst to the temperature of 100-160° C. before the formation of the aerosol.
[0029] Preferably, the temperature of the water vapour used to form the aerosol is 100-160° C.
[0030] In order to ensure the stability of the prepared aerosol, preferably, the difference of the temperature of the mixed solution of the diisocyanate and the catalyst and the temperature of the water vapour is no more than 10° C., preferably no more than 2° C.
[0031] In the method of the present invention, the molar ratio of the diisocyanate and the water vapour is 3:1-15:1, preferably 5:1-12:1.
[0032] In the method of the present invention, the water vapour can form an aerosol with the mixed solution of the diisocyanate and the catalyst directly to carry out a reaction; it is also possible to dilute the water vapour by an inert gas then allow the diluted water vapour to form aerosol to carry out a reaction. Preferably, the water vapour is not diluted by inert gas but is reacted directly.
[0033] When water vapour is diluted by an inert gas, the continuous phase of the aerosol formed in step a) is the mixed gas of the water vapour and the inert gas. Said inert gas should not be reacted with diisocyanate and the catalyst under reaction condition. Said inert gas is for example carbon dioxide, carbon monoxide, nitrogen, helium, argon, hydrocarbons such as methane and so on and mixtures thereof, preferably carbon dioxide and/or nitrogen, especially preferably nitrogen.
[0034] The molar ratio of said inert gas and the water vapour is 0:100-1:0.1, especially preferably 0:20-1:1, more preferably 0-1000:100, more preferably 0-100:100.
[0035] Solvents cannot be added or can be added to the mixed solution of the diisocyanate and the catalyst for dilution.
[0036] Preferably, no solvents are added to the mixed solution of the diisocyanate and the catalyst for dilution.
[0037] When solvents are added to the mixed solution of the diisocyanate and the catalyst, the dispersed phase of the aerosol formed in step a) is the mixed solution of the diisocyanate, the catalyst and the solvents. Suitable solvents are for example: butyl acetate, ethyl acetate, tetrahydrofuran, propylene glycol methyl ether acetate, dimethylbenzene, propylene glycol diacetate, butanone, methyl isoamyl ketone, cyclohexanone, hexane, toluene, dimethylbenzene, benzene, chlorobenzene, o-dichlorobenzene, hydrocarbon mixtures, dichloromethane and/or trialkyl phosphate, preferably propylene glycol methyl ether acetate, triethylphosphate, tri-n-butyl phosphate, trimethyl phophate and or mixtures of these compounds in any proportion. Solvents are selected to be added to somehow inhibit the formation of polyurea, meanwhile, adding solvents will decrease the space-time yield of the reaction.
[0038] Preferably , no solvents are added to the mixed solution of the diisocyanate and the catalyst in the method of the present invention.
[0039] In the method of the present invention, the conversion rate of water vapour in the first reactor is 80-95%, preferably 85-92%, based on the water vapour enter into the first reactor.
[0040] More preferably, the total conversion rate of water vapour after step b) is larger than 95%, preferably larger than 99%, based on the water vapour enter into the first reactor.
[0041] It is revealed by studying that it is only when the conversion rate of the water vapour in the first reactor is larger than 80%, the total conversion rate of the water vapour of the second reactor can be guaranteed to be larger or equal to 95%; when the conversion rate of the first reactor is larger than 95%, the volume of the reaction device will increase dramatically, too large device will result in a huge investment and the device will be difficult to be processed. The total conversion rate of the second reactor can be guaranteed to be above 95% or even above 99% by strictly controlling the conversion rate of water vapour of the first reactor. Because of the high conversion rate of water vapour, there's very little water in the second reactor after condensation, thus there's little chance for the liquid water to form polyurea with diisocyanate, there's no solid polyurea or very little polyurea formed in the condenser tube, thus solving the problem of the blocking by polyurea in condenser tubes and tail gas exhaust pipes, which greatly decrease the frequency of cleaning the pipes; diisocyanate gas will not react or will seldom be reacted to form polyurea and will return to the second reactor after condensation, thus the loss rate is very low; the polyurea content in the biuret polyisocyanate products obtained finally is very low, allowing to produce products with great homogeneity, high gloss and transparent appearance, when used to prepare coatings, the prepared coatings will have very excellent performances such as anti-corrosion.
[0042] During the preparation process, the conversion rate of water vapour can be adjusted comprehensively by the temperature and pressure of the first and the second reactor and the residence time of the aerosol in the first and the second reactor. The conversion rate of water vapour can be determined by extracting the aerosol in the first reactor, measuring the content of carbon dioxide in said reactor and then converting the measurement.
[0043] Preferably, the residence time of aerosol in the first reactor is 10-60 min, preferably 20-40 min.
[0044] In the method of the present invention, the absolute pressure in the first reactor is 0.1-1 Mpa, preferably 0.11-0.15 Mpa, the temperature in the reactor is 100-160° C. When the above pressure and temperature are used, the conversion rate of water vapour in the first reactor can be guaranteed within the above suitable range.
[0045] As the device for the reaction of the aerosol formed by the mixed solution of the diisocyanate and the catalyst and the water vapour, said first reactor can be a vertical tubular reactor, a tower reactor or a tank reactor with high height-to-diameter ratio, preferably a tower reactor.
[0046] In one embodiment of the present invention, said first reactor can be a device group composed of two or more of the above reactors that are vertically connected in series.
[0047] After the reaction of the aerosol formed by the mixed solution of the diisocyanate and the catalyst and water vapour in the first reactor, the obtained reaction mixture is still in the form of aerosol, said reaction mixture can be provided from the top or bottom of the first reactor, preferably from the top of the first reactor. It's important to note that in “the product obtained in step a) is brought into a second reactor for a further reaction” described in the above step b), the “product” actually means the reaction mixture in the aerosol form that includes the produced biuret polyisocyanate, carbon dioxide, unreacted diisocyanate and water vapour etc., which can be easily understood by those skilled in the art.
[0048] The outlet of the first reactor and the inlet of the second reactor can be connected by an insert tube. In order for the mixture in the second reactor to disperse more homogeneously, preferably, the end of the insert tube that is connected to the second reactor is equipped with a porous dispersion device.
[0049] The reaction of the aerosol formed by the mixed solution of the diisocyanate and the catalyst and water vapour in the first reactor lasts until the conversion rate of water vapour reaches 80-95%, then the aerosol enters into the second reactor under pressure. On top of the second reactor, it is provided a condensation reflux device and a tail gas exhaust pipe, said tail gas exhaust pipe is connected to the tail gas processing system. Said tail gas processing system can be a solvent-absorbing system or a waste oil- washing system, to absorb the diisocyanate component left in tail gas and thus to avoid pollution in air.
[0050] The average residence time of water vapour in the second reactor is 20-200 min, preferably 30-120 min.
[0051] The reaction pressure in the second reactor is atmospheric pressure, the temperature of the reactor is 120-160° C.
[0052] The reaction carried out in the second reactor is mainly the reaction of the mixed solution of a diisocyanate and a catalyst with water vapour, in the state of aerosol. The separation of gas and liquid is achieved after the reaction, wherein the liquid components are mainly the produced biuret polyisocyanate and the unreacted diisocyanate raw material, and the gas components are mainly the produced carbon dioxide and trace of water vapour and diisocyanate gas.
[0053] Suitable reactor for the second reactor can be a tank reactor or a tower reactor, preferably a tank reactor.
[0054] Based on the water vapour entered into the first reactor, the total conversion rate of the water vapour in the second reactor is larger than or equal to 95%, preferably the total conversion rate of water vapour is larger than or equal to 99%. The total conversion rate of water vapour can be determined by measuring the carbon dioxide content in tail gas. When the reaction in the second reactor reaches the above conversion rate of water vapour, the liquid mixture in the second reactor is pumped into the third reactor.
[0055] It is important to note that in “the reaction liquid obtained in step b) is further reacted in a third reactor” described in the above step c), the “reaction liquid” means the liquid reaction mixture obtained after the reaction in the second reactor.
[0056] In the method of the present invention, the reaction temperature of the third reactor is 130-180° C., the reaction pressure is atmospheric pressure, the average residence time is 20-200 min, preferably 60-120 min.
[0057] The maturing in the third reactor is mainly the reaction of the produced biuret polyisocyanates with diisocyanate raw materials to produce biuret polyisocyanates with higher functionality. The products produced after maturing have great monomer stability i.e. are unlikely to break into free diisocyanates. The materials and the products in the third reactor are all liquid.
[0058] Said third reactor can be a tubular reactor, a tank reactor etc., preferably a tubular reactor. It is revealed that continuously maturing in tubular reactors can significantly improve the stability of the products.
[0059] In the method of the present invention, separation devices are used to perform the separation of the reaction liquid obtained in step c) for removing monomers to separate biuret polyisocyanate from the unreacted excess diisocyanate raw materials. Said separation devices can be a film evaporator and/or a short-path evaporator. A two-stage separation device can be used in said step, the separation device for the first stage is preferably a film evaporator, the temperature for the separation of the materials is 130-170° C., the absolute pressure is 50-300 Pa; The separation device for the second stage is preferably a short-path evaporator, the separation temperature of the materials is 140-180° C., the absolute pressure is 5-30 pa. The diisocyanate monomer content in the product obtained by the separation using the above separation devices and conditions can be lower than 0.5 wt %, even lower than 0.3 wt %, the quality of the product is great.
[0060] The biuret polyisocyanate product obtained by separation can be diluted by solvents, it can be diluted by one or two of propylene glycol methyl ether acetate, butyl acetate, ethyl acetate, dimethylbenzene, the content of biuret polyisocyanate in the diluted solution is 75±1 wt %.
[0061] The “OH-acidic compound” in the present invention is the —OH-containing compounds that can dissociate H + .
[0062] The “average residence time” in the present invention is the average time for the reaction materials from entering into the reactor to leaving the reactor.
[0063] The “space-time yield” in the present invention is the mass of product obtained in unit time for a unit volume or unit area of reactor device.
[0064] The “water vapour conversion rate” or the “conversion rate of water vapour” is the mass ratio of the water vapour participates in the reaction in the reactor and the water vapour enters into the reactor.
[0065] The “biuret polyisocyanates” and the “ polyisocyanates comprising biuret structures” in the present invention means the same.
[0000] Compared with the prior art technology, the advantages of the present invention lie in:
[0066] 1. The reaction materials in the present invention are mixed and reacted in the form of aerosol, which largely increase the contact area of water vapour and the mixed solution of the diisocyanate and the catalyst, and significantly increase the conversion rate of water vapour, avoiding the problem of forming a large amount of solid polyurea caused by the reaction of liquid water or water vapour with diisocyanate in the prior art technology.
[0067] 2. In the present invention, the total conversion rate of the water vapour can reach to above 95% by reasonably adjusting the conversion rate of the water vapour in the first and second reactors, which largely decrease the amount of free water or water vapour. When tail gas is condensed through the condenser, there's very little solid polyurea generated in the tail gas exhaust pipe or the condenser, the loss of diisocyanate material is significantly decreased, and the problem of the blocking of the condenser and the tail gas exhaust pipe is solved.
[0068] 3. The content of solid polyurea is very low in the product, the content of diisocyanate monomer is also very low, the product possess high homogeneity, good gloss, great application performances. Especially when the obtained products are used to prepare coatings, the prepared coatings possess very excellent anti-corrosion property.
DETAILED DESCRIPTION OF THE INVENTION
[0069] The present invention will be further illustrated by the following examples, it should be noted that the examples are not the limitations for the extent of protection of the present invention.
[0070] The test method of the content of diisocyanate monomers in the examples and the comparative examples:
[0071] About 1 g (exact value 0.0001 g) biuret polyisocyanate sample is weighed and placed in 25 ml volumetric flask, about 10 ml dichloromethane is added to dissolve and mix homogeneously, then about 5 ml dibutylamine and two drops of dibutyltin dilaurate are added, and dichloromethane is added until the scale mark of the volumetric flask is tangent with the lowest position of the liquid level. The volumetric flask is placed into oven at 50° C. for 3 hours, then it is taken out and cooled, then dichloromethane is added until the scale mark of the volumetric flask is tangent with the lowest position of the liquid level, after the filtration by 0.45 μm filter membrane, the solution is injected into a liquid chromatograph for analysis, the injection volume is 10 μL. Then a standard curve is made by the corresponding diisocyanate, and the content of monomers is obtained by quantifying with an external-standard calibration curve method.
[0072] Liquid chromatographic analysis: Shimadzu LC-20AT, with SIL-20A autosampler, CTO-10AS column incubator, SPD-20A tester, the conditions of chromatography: chromatographic column: Wondasil C18 5 μm (4.6 mm×250 mm), gradient elution: water:methano 1 =67:33, column temperature 40° C., flow rate: 1.0 ml/min, detection wavelength: 258 nm, quantitative method: external standard method.
Example 1
[0073] The mixed solution of hexamethylene diisocyanate and the catalyst, dibutyl phosphate was prepared, wherein the amount of dibutyl phosphate was 0.2 wt % of the mass of hexamethylene diisocyanate, said mixed solution was pumped continuously into the preheater for preheating to 155° C.; water vapour was preheated to 155° C. in another preheater, then the mixed solution and the water vapour were added to the device for preparing aerosol, the flow rate of the mixed solution of hexamethylene diisocyaante and the catalyst was 15 kg/h, the feeding rate of water vapour was 0.15 kg/h, the mixed solution and the water vapour were dispersed to prepare aerosol, in the aerosol, the continuous phase was the water vapour, the dispersed phase was the mixed solution of hexamethylene diisocyanate and dibutyl phosphate, the average droplet size in the dispersed phase in the aerosol was 3 μm. The obtained aerosol entered into the first reactor through the top of the first reactor, a vertical tower reactor for a reaction, the pressure in the first reactor was 0.25 MPa, the temperature was 155-160° C., the average residence time of aerosol in the first reactor was 25 min, the conversion rate of the water vapour was 90% (based on the water vapour enter into the first reactor), then the mixture in the aerosol form entered into the second reactor which is a stirring tank reactor from the first reactor through the insert tube. The top of the second reactor was provided a condenser with circulating water for cooling and refluxing. The temperature in the second reactor was 155-160° C., the average residence time of the reaction liquid in the second reactor was 50 min, the total conversion rate of water vapour was 99.5% (based on the water vapour entered into the first reactor). The separation of the gas and the liquid was achieved substantially after the reaction of the reaction mixture in the second reactor, wherein the gas was condensed and refluxed with the condenser, the temperature of the condensed water was 25-35° C., the mixed liquid entered into the third reactor, a tubular reactor. The temperature in the third reactor was 155-160° C., the average residence time of the reaction liquid in the third reactor was 100 min, the obtained reaction liquid was separated by a two-stage film evaporator to remove monomers, the diisocyanate monomers contained were removed to obtain products with 100% solid content of biuret. In the two-stage film evaporator, the separation temperature of the first-stage film evaporator was 130° C., the absolute pressure was 50 pa; the separation temperature of the second film evaporator was 140° C., the absolute pressure was 5 pa, biuret products was obtained by separation. The loss of hexamethylene diisocyanate was 0.11 wt % (based on the hexamethylene diisocyanate added in the first reactor). The content of the diisocyanate monomers in the product was 0.15 wt % (liquid chromatographic analysis, the same as below), the color number was 5# (Pt—Co color), the product was very transparent, and the frequency for cleaning the tail gas pipe was once/12 months.
Example 2
[0074] The mixed solution of H 12 MDI and the catalyst, propanoic acid was prepared, wherein the amount of propanoic acid was 1 wt % of the mass of H 12 MDI, said mixed solution was pumped continuously into the preheater for preheating to 130° C.; water vapour was preheated to 130° C. in another preheater, then the mixed solution and the water vapour were added to the device for preparing aerosol, the flow rate of the mixed solution of H 12 MDI and propanoic acid was 15 kg/h, the feeding rate of water vapour was 0.34 kg/h, the mixed solution and the propanoic acid were dispersed to prepare aerosol, in the aerosol, the continuous phase was the water vapour, the dispersed phase was the mixed solution of H 12 MDI and propanoic acid, the average droplet size in the dispersed phase in the aerosol was 50 μm. The obtained aerosol entered into the first reactor through the top of the first reactor, a vertical tower reactor for a reaction, the pressure in the first reactor was 0.45 MPa, the temperature was 130-135° C., the average residence time of aerosol in the first reactor was 10 min, the conversion rate of the water vapour was 80% (based on the water vapour enter into the first reactor), then the mixture in the aerosol form entered into the second reactor which is a stirring tank reactor from the first reactor through the insert tube. The top of the second reactor was provided a condenser with circulating water for cooling and refluxing. The temperature in the second reactor was 135-140° C., the average residence time of the reaction liquid in the second reactor was 110 min, the total conversion rate of water vapour was 98.5% (based on the water vapour entered into the first reactor). The separation of the gas and the liquid was achieved substantially after the reaction of the reaction mixture in the second reactor, wherein the gas was condensed and refluxed with the condenser, the temperature of the condensed water was 25-35° C., the mixed liquid entered into the third reactor, a tubular reactor. The temperature in the third reactor was 135-140° C., the average residence time of the reaction liquid in the third reactor was 35 min, the obtained reaction liquid was separated by a two-stage film evaporator to remove monomers, the diisocyanate monomers contained were removed to obtain products with 100% solid content of biuret. In the two-stage film evaporator, the separation temperature of the first-stage film evaporator was 150° C., the absolute pressure was 150 pa; the separation temperature of the second film evaporator was 160° C., the absolute pressure was 25 pa, biuret products was obtained by separation. The loss of H 12 MDI was 0.15 wt % (based on the H 12 MDI added in the first reactor). The content of the diisocyanate monomers in the product was 0.35 wt %, the color number was 5# (Pt—Co Color), the product was transparent, and the frequency for cleaning the tail gas pipe was once/5 months.
Example 3
[0075] The mixed solution of isophorone diisocyanate and the catalyst, dibutyl phosphate was prepared, wherein the amount of dibutyl phosphate was 0.2 wt % of the mass of isophorone diisocyanate, said mixed solution was pumped continuously into the preheater for preheating to 110° C.; water vapour was preheated to 110° C. in another preheater, then the mixed solution and the water vapour were added to the device for preparing aerosol, the flow rates of isophorone diisocyanate and dibutyl phosphate were 15 kg/h, the feeding rate of water vapour was 0.21 kg/h, the mixed solution and the dibutyl phosphate were dispersed to prepare aerosol, in the aerosol, the continuous phase was the water vapour, the dispersed phase was isophorone diisocyanate and dibutyl phosphate, the average droplet size in the dispersed phase in the aerosol was 38 μm. The obtained aerosol entered into the first reactor through the top of the first reactor, a vertical tower reactor for a reaction, the pressure in the first reactor was 0.85 MPa, the temperature was 110-115° C., the average residence time of the aerosol in the first reactor was 40 min, the conversion rate of the water vapour was 92% (based on the water vapour enter into the first reactor), then the mixture in the aerosol form entered into the second reactor which is a stirring tank reactor from the first reactor through the insert tube. The top of the second reactor was provided a condenser with circulating water for cooling and refluxing. The temperature in the second reactor was 120-125° C., the average residence time of the reaction liquid in the second reactor was 30 min, the total conversion rate of water vapour was 95.5% (based on the water vapour entered into the first reactor). The separation of the gas and the liquid was achieved substantially after the reaction of the reaction mixture in the second reactor, wherein the gas was condensed and refluxed with the condenser, the temperature of the condensed water was 25-35° C., the mixed liquid entered into the third reactor, a tubular reactor. The temperature in the third reactor was 130-135° C., the average residence time of the reaction liquid in the third reactor was 180 min, the obtained reaction liquid was separated by a two-stage film evaporator to remove monomers, the diisocyanate monomers contained were removed to obtain products with 100% solid content of biuret. In the two-stage film evaporator, the separation temperature of the first-stage film evaporator was 170° C., the absolute pressure was 300 pa; the separation temperature of the second film evaporator was 180° C., the absolute pressure was 30 pa, biuret products was obtained by separation. The loss of isophorone diisocyanate was 0.13 wt % (based on the isophorone diisocyanate added in the first reactor). The content of the diisocyanate monomers in the product was 0.46 wt %, the color number was 7.5# (Pt—Co color), the product was transparent, and the frequency for cleaning the tail gas pipe was once/4 months.
Comparative Example 1
[0076] In the three tank reactors that are connected in series, hexamethylene diisocyanate and water vapour were inlet into the first reactor tank, the temperature of the first reactor was 130-140° C., the flow rate of hexamethylene diisocyanate was 15 kg/h, the catalyst was dibutyl phosphate, the dibutyl phosphate was 0.2 wt % of the mass of the hexamethylene diisocyanate, the feeding rate of the water vapour was 0.3 kg/h, the average residence time of hexamethylene diisocyanate was 30 min, the tail gas of the reactor was cooled and refluxed by circulating water, the temperature of the circulating water was 25-35° C., after condensation, the tail gas entered into a waste liquid tank. The reaction liquid overflew to the second reactor, the average residence time of hexamethylene diisocyanate was 60 min, then the reaction liquid overflew to the third reaction tank, the average residence time of hexamethylene diisocyanate was 160 min. The temperature of the second and the third reaction tanks for producing products were maintained at 140-145° C., the obtained reaction liquid was separated by a two-stage film evaporator to obtain biuret polyisocyanate products, the separation conditions are the same as that of example 1, the color number of the product was 7.5# (Pt—Co color), the content of monomers was 0.17 wt %, the product was white, the loss of hexamethylene diisocyanate was 4.17% (based on the hexamethylene diisocyanate added to the first reactor), and the frequency for cleaning the tail gas pipe was once/1 month.
Comparative Example 2
[0077] In the three tank reactors that are connected in series, H 12 MDI and water vapour were inlet into the first reactor tank, the temperature of the first reactor was 135-140° C., the flow rate of H 12 MDI solution was 15 kg/h, said solution contains 1 wt % catalyst, propanoic acid, 5 wt% propylene glycol methyl ether acetate, the flow rate of water vapour is 0.27 kg/h, the average residence time of H 12 MDI in the first reactor is 30 min, the reaction tail gas refluxed directly after being condensed. The reaction liquid overflew to the second reactor, the average residence time of H 12 MDI was 60 min, then the reaction liquid overflew to the third reaction tank, the average residence time of H 12 MDI was 170 min. The temperature of the second and the third reaction tanks for producing products were maintained at 135-140° C., the tail gas of the first, second and third reactors were cooled and refluxed by circulating water, the temperature of the circulating water was 25-35° C.; the mixed solution was filtered by 1 μm filter cloth, the reaction liquid obtained by a two-stage separation after filtration was separated by a two-stage film evaporator to obtain biuret polyisocyanate product, the separation conditions are the same as that of example 2. The color number of the obtained product was 17# (Pt—Co color), the product was white, the content of monomers was 0.42 wt %, the loss of H 12 MDI was 0.21%, the loss of solvent was 3.5%, and the frequency for cleaning the tail gas pipe was once/4 months.
[0078] It can be seen that with the method of the present invention, very little amount of polyurea will be generated in the tail gas pipe, and high quality products can still be obtained under longer cleaning cycle. For example, the frequencies for cleaning in examples 1-3 are once/12 months, once/5 months, once/4 months respectively, the color numbers of the prepared products are 5#, 5#, 7.5# respectively, while in comparative example 1 , only when the frequency for cleaning is once/1 month, the product of color number 7.5# will be obtained. In comparative example 2, when the adopted frequency for cleaning is the same as that of example 3, the color number is 17#, the product is obviously white.
[0079] In addition, with the method of the present invention, the tail gas can return to the reaction mixture after condensation while the quality of the products are still guaranteed, which decrease the loss rate of diisocyanate raw materials and save the materials. For example, the loss rate of diisocyanate in examples 1-3 are all below 0.15%, although the product of color number 7.5# can be obtained in comparative example 1, but the tail gas in the comparative example 1 entered directly into a waste liquid tank after condensation, the loss rate of diisocyanate materials is up to 4.17%; however, the tail gas in comparative example 2 returned to the reaction mixture after condensation, although the loss rate of diisocyanate was low, only 0.21%, but the color number of the product was 17#, the product was white.
[0080] Furthermore, from the comparison between the present examples and the comparative examples, when the same kind of diisocyanates was used as raw materials, the content of diisocyanate monomers in the products obtained according to the method of the present invention was low, and the quality of the products obtained according to the method of the present invention was better.
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A method for continuously preparing biuret polyisocyanate, comprising: a mixed solution of a diisocyanate and a catalyst with water vapour, in an aerosol form, are continuously reacted in a first reactor; the product obtained therefrom is brought into a second reactor for a further reaction; a tail gas from the second reactor is condensed and refluxed, and the non-condensable gas is brought into a tail gas treatment system; a reaction liquid obtained in the second reactor is further reacted in a third reactor; and then separation is performed for removing monomers, so as to obtain biuret polyisocyanate.
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FIELD OF THE INVENTION
This invention relates to closures of the type designed to be received by the water outlets of sanitary flush tanks. More particularly, the invention is directed to a universal flapper valve which is provided in a kit and designed to fit most current flush commodes.
BACKGROUND OF THE INVENTION
Ordinarily, water outlets of most American sanitary flush tanks comprise either a flapper valve of known construction or a tank ball-valve. Both are designed to effect a delayed sealing of the water outlet of the sanitary flush tank in which they are installed. By closing this water outlet, the outflow of water from the tank to the toilet bowl ceases and the tank is allowed to refill to its desired level. Flow of water into the tank is then terminated in a known fashion. Existing valves are generally composed of either vinyl or rubber formed in various shapes.
It has been learned from research that 45% of water use in the average living environment is in the washroom, and a large percentage of that use is through sanitary fixtures and constitutes flush water. Data which has been gathered indicates that 15% to 30% of this total water use is lost due to leaky flapper valves or faulty ball-cocks (fill valves) ball-valves installed in the flush tanks. Such leakage is usually caused either by improper seating of the valve-stop on the water outlet or by deterioration of the sealing material, although there are, of course, other causes. Research has also ascertained that water lost through faulty ball-cocks causes approximately 15% of the total loss, whereas approximately 85% is due to faulty flapper valves. Based on such estimates, the water lost caused by faulty flapper valves alone amounts to 12% to 25% of the total water use in the average American household or business.
Materials used to effect the seal of the ball-valve or flapper valve against the water outlet are of considerable importance. The material selected should be both durable and flexible and should retain its flexibility over long periods of time while it is immersed in water. Generally either rubber or vinyl are currently used for stop valves which are commercially available. However, research suggests that valve stops constructed of such materials begin to leak silently and undetectably to the average homeowner in a surprisingly short period of time.
A vexing problem that faces the consumer who seeks to replace a system previously or originally installed in a flush tank is the wide variety of devices which are commercially available, each having been designed with a specific system in mind. There is an enormous diversity among marketed devices whereby prospective buyers are faced with the unfortunate and undesirable problem of determining the optimal system for their particular flush tanks to be selected from among many varieties of competing systems, any one of which may be unsuitable for their particular flush tanks. There is a need for a stop valve system which has universal or almost universal adaptability to be received by most flush tank systems currently installed in American homes, offices and factories. Moreover, there is a need that such a universal system provide a dependable closure of the flush water outlet and not be such that it commences to leak silently and undetectably shortly after installation.
SUMMARY OF THE INVENTION
The instant invention is essentially a kit having specific parts which permit it to be assembled and used with all or almost all known commercial types of commodes regardless of age. To accomplish this, a donut or ring-shaped seal is used which is received in a peripheral circular slot to provide an essentially flat-shaped seal member in one configuration, and which also can be received in a further circular peripheral slot to assume a conical shape in a different arrangement. An important object of the present invention is to provide a valve-stop system which can be received and installed without undue difficulty in most water tanks found in bathrooms of American homes, offices, businesses and factories, while, at the same time, overcoming the other problems of material deterioration and improper seating.
It has been found that this can be accomplished in the combination disclosed by the use of a relatively thin gasket ring or donut-shaped member composed of silicone RTV. Such gasket ring may be successfully employed as a valve-stop for most currently installed sanitary flush tanks and a support body may be provided which supports the gasket in at least two optional arrangements so as to be a suitable replacement for both flapper valves and ball-valves valve stops which are standard in most flush tanks.
In addition, the plastic molded flapper body has an extremely long life (greater than 15 years) so that only the gasket material will need to be replaced periodically. This is a simple and inexpensive task.
Other objects, adaptabilities and capabilities of the invention will appear and be appreciated by those skilled in the art as the description progresses, of references being had to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the invention in partial section showing the ring valve in a first arrangement;
FIG. 2 is a front elevational view and partial section similar to FIG. 1 which shows the ring valve part in a second arrangement;
FIG. 3A is a top plan view of the valve support body in accordance with the invention;
FIG. 3B is a side elevational view of the valve support body shown in FIG. 3A;
FIG. 3C is a bottom view of the same support body;
FIG. 3D is a sectional view taken across the center line shown in FIG. 3A;
FIG. 3E is a detailed enlarged view of the main outwardly projecting ring and the shorter outwardly extending rings which form a groove for the ring valve member;
FIG. 3F is a detailed view illustrating how a chain link is snapped on a hook projecting upwardly from the surface of the main ring;
FIG. 4A is a top plan view of a stopper yoke which is utilized to connect to a further hook on the main ring of the valve support body;
FIG. 4B is a front view of the yoke shown in FIG. 4A;
FIG. 4C is a back view of such yoke;
FIG. 4D is a side elevational view of the same yoke;
FIG. 4E is an enlarged view in partial section taken on section lines A--A of 4A;
FIG. 5A is a plan view of a hinge collar to which the stopper yoke is connected and which embraces the overflow pipe of the flush tank;
FIG. 5B is a side elevational view of the hinge collar shown in FIG. 5A;
FIG. 5C shows the other side of the hinge collar;
FIG. 5D is a rear view of the hinge collar;
FIG. 6A is a top plan view of a gasket adaptor for the ring valve;
FIG. 6B is a side view of the adaptor shown in FIG. 6A;
FIG. 6C is a bottom view of the same adaptor;
FIG. 6D is a sectional side elevational view of the adaptor through its diameter;
FIG. 6E is an enlarged view of one edge of the adaptor as shown in FIG. 6D;
FIG. 7A is a plan view of the bottom plug which is affixed to the bottom of the valve support body;
FIG. 7B is a side view of the plug shown in FIG. 7A;
FIG. 7C is a sectional view of the same plug through the diameter thereof;
FIG. 8A is a side elevational view of a clip-on axle for American Standard flush commodes;
FIG. 8B is a plan view of the clip-on axle shown in FIG. 8A;
FIG. 8C is a sectional view of the clip-on axle taken through section lines A--A of FIG. 8A;
FIG. 8D is a further sectional view taken through the section lines B--B of FIG. 8B;
FIGS. 9A through 9G illustrate the parts which are included in a kit in accordance with the invention;
FIG. 10A is a perspective view showing the configuration of the invention in a usual or normal type of installation;
FIG. 10B is a perspective view which illustrates the parts as assembled for an American Standard flush commode;
FIG. 10C is a figure similar to FIGS. 10A and 10B for installations of Crane and other manufacturers;
FIG. 10D is a similar perspective assembly view wherein a rod rather than a chain and hook are used such as for Eljer and other types of flush commodes;
FIG. 10E is a similar perspective assembled view of the parts required for installation in a further type of flush commode; and
FIG. 11 is a perspective exploded view illustrating the assembly of the various components for an American Standard installation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, and particularly FIG. 1, the valve support body is referred to generally by reference numeral 1 and comprises a one-piece injected molded body of plastic material, preferably Lexan, a thermoplastic carbonate-lined polymer, which may be either crystal-clear or color coated, depending upon sales and distribution requirements. Body 1 includes an outwardly projecting rib or ring 3 which is generally a flat configuration and is integral and formed so as to be of one piece with the upper section 2 of body 1. Projecting from the upper surface of ring 3 and at diametrically opposite sides thereof are two hook-like projections 4 and 5. Projection 4 is designed to engage an operating chain (not shown) and hook-like projection 5 engages the stopper yoke 10. Situated below ring 3 and projecting outwardly from section 2 and part of the same one-piece construction are two further ribs or rings 6, only the lower ring 6 being shown in FIG. 1. However, as seen in FIG. 3D, rings 6 are spaced apart from each other to define a cavity 9 which encircles section 2. It will be noticed that rings 6 are of a substantially less radial dimension than ring 3. They serve as supports to engage the flat donut-shaped gasket or ring valve 30 in a snug, water-tight relationship between the side walls of ring 6 and within cavity 9. Although gasket 30 may be constructed of any durable, water resistant material, preferably it is silicone RTV.
Although the preferred material for the gasket is RTV, a silicone rubber purchased as a silicone sheeting inasmuch as impurities in water very considerably geographically there are other materials which may be preferable for certain locations. A very good gasket material is available under the trademark "Viton"which is a fluoroelastomer. It is highly resistant to corrosive liquids. A terpolymer elastomer made from ethylene-propylene diene monomer (EPDM) may also be used. The material selected preferably has a hardness factor in the range of 50 to 70 durometers and preferably 60 durometers.
Valve support body 1 with gasket 30 arranged as shown in FIG. 1, when in closed position, engages the water outlet 25 of the flush tank in a water-tight relationship, the gasket 30 as shown in FIG. 1 is securely pressed by the water pressure in the tank against ring 3 and has a shallow frusco-conical shape.
The lower end of section 2 terminates at an opening 7 which snugly and in a water-tight fashion receives plug 35 which is preferably affixed thereto. As shown in FIG. 3D, the upper side of section 2 includes a bore 8 which is threaded and so dimensioned to receive the bottom portion of a standard rod 40 of a type well known for prior art valves in a threaded engagement. Bore 8 is of sufficient depth to ensure that rod 40 and section 2 are firmly secured together when rod 40 is threadably received in bore 8.
The stopper yoke 10 is shown in detail in FIGS. 4A through 4E. It comprises two arms 11 which terminate in snap-clamps 12. A space 14 of semi-circular configuration is defined by two smaller resilient arms 13 which extend towards each other. On the opposite side of yoke 10 are two projecting arms 15 which are joined by an intermediate pivot member 16. These projecting arms 15 engage hook 5 to function as a pivot for yoke 10, allowing a small amount of play between the body 1 and yoke 10. Arms 13 are adapted so that they can snap into either existing, standard fittings for flapper valves such as those which are frequently installed in sanitary flush tanks, or alternatively into pivot extensions 17 of hinge collar 18 which is shown in detail in FIGS. 5A through 5D. Hinge collar 18 is used when either no flapper valve had been previously installed in the sanitary flush tank, or a flapper valve had been previously installed but was found to be dimensionally incompatible with the valves of the instant invention. In the event hinge collar 18 is installed, arms 19 are snapped around the existing overflow tube 26 or a support for same such as the rectangular amount used by Crane commodes. Valve seat 25 is shown as horizontally disposed in FIG. 1. However, it is often tilted at about 15° away from overflow tube 26.
Referring now to FIG. 2 and FIGS. 6A-6E, the adaptor 20 shown therein forms an important aspect of the invention. Adaptor 20 is preferably of one piece construction and comprises a flat, cylindrical body, with one end closed by wall 21. Wall 21 together with a further circular wall 22 define a cylindrical cavity 23. Projecting outwardly from wall 22 are two circular ribs or rings 24 of similar dimensions which together define a circular groove 25. Cavity 23 is of an appropriate size and configuration so that it fits snugly over the opening 7 in the lower part of section 2, thereby closing section 2 and trapping air therein not already trapped by plug 35. When adaptor 20 is so attached to section 2, it will be seen that wall 22 along with rings 24 and groove 25 extend outwardly beyond the radial dimensions of rings 6. Therefore when gasket 30 is fitted in its lower opening onto adaptor 20 between walls 24 and into groove 25, gasket 30 is stretched approximately 18% more than its configuration when received in cavity 9. This stretched arrangement and configuration of gasket 30 assumes the shape of a truncated cone as seen in FIG. 2 which closely matches the contour of existing ball-flappers.
The clip-on axle as shown in FIGS. 8A-8B is designed in particular to adapt the invention for insulation on American Standard flush mechanisms as installed in their toilet tanks.
When a kit containing the parts described above is utilized in a mechanism for tank flushing that uses a regular flapper valve, then the parts used are those shown in FIG. 1. However, when a ball-valve is to be replaced, then the parts used will often conform to those shown in FIG. 2. With American Standard, then the part 27 illustrated in FIGS. 8A-8D is employed together with the valve support body 1, the adaptor 20, and the yoke 10. For replacement of the Crane flapper valve, hinge collar 18 will also be required. In addition to the parts illustrated and described, the kit also includes a chain and a hook for the chain.
The parts ordinarily provided in a kit in accordance with the invention are illustrated by FIGS. 9A, 9B, 9C, 9D, 9E, 9F and 9G, which are respectively, gasket 30, yoke 10, body 1, hook and chain 34, adaptor 20, clamp 18 and axle 27. FIGS. 10A, 10B, 10C, 10D and 10E illustrate various assemblies which can be constructed from the kit, thus 10A shows a normal or usual configuration which is frequently found in flush tanks and includes gasket 20, yoke 10, body I, and the hook and chain combination 34. For many American Standard tanks, the assembly shown in FIG. 10B is used which includes, yoke 10, axle 27, body 1, hook and chain combination 34, adaptor 20, and gasket 30.
An assembly for Crane flush tanks and others is shown in FIG. 10C, which includes a clamp 18, yoke 10, body 1, together with gasket 30, and the hook and chain combination 34.
In FIG. 10D for Elger flush tanks and others, there is a body 10, which includes a bore 8 for receiving a rod 40 (not shown in FIG. 10D), an adaptor 20 and gasket 30.
The parts for a further type of flush tank are shown in FIG. 10E and are the same as for the normal configuration except that there is an adaptor 20 to assume the frusco-conical shape.
In each of FIGS. 10A through 10E, the gasket 30 is illustrated somewhat lower than its actual position relative to body 1.
An assembly drawing, with the parts exploded, is shown in FIG. 11, which includes the yoke 10, axle 27, body 1, hook and chain combination 34, adaptor 20 and gasket 30.
From the foregoing, it will be appreciated by those skilled in the art that with the seven parts provided as shown in FIGS. 9A through 9G, the kit can be used in a simple manner to construct an advantageous replacement valve part for almost all commercial flush tanks which are normally found in this country.
In addition, suitable directions are, of course, included with the kit for the various adaptations thereof.
It is to be understood that although the preferred embodiments of the invention have been disclosed herein, it is capable of other adaptations and modifications within the scope of the following claims:
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A kit that includes a universal flapper and water saver valve stop for the fluid outlet of sanitary flush tanks utilizing a flat, thin, doughnut shaped gasket mounted on alternate supports, wherein the use of one support allows the doughnut shaped gasket to maintain its relatively flat configuration as in standard flapper valves, and the use of the alternate support stretches the doughnut shaped gasket to form a truncated cone, the dimensions of which closely follow those of standard ball valves, and the support structure for the valve stop includes at least two connecting devices for alternately connecting the valve stop to the different types of connecting assemblies found in standard flush tanks.
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RELATED APPLICATIONS
[0001] This application claims priority to Korean Patent Application No. 2001-0044782, filed on Jul. 25, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to a piling apparatus and a process for the purpose of improvement of soft-ground earth in which buildings and marine structures are built thereon.
DESCRIPTION OF THE PRIOR ART
[0003] In the prior art, there has been provided injection holes having a desired diameter and depth for constructing a reinforced bar concrete pile in the earth. The purpose of which is to improve the existing soft-ground. In this case, reinforced bars are charged into concrete injection holes, and concrete is injected, filled, and stamped. Finally, through curing, the reinforced bar concrete pile is constructed.
[0004] Until now, Pedestal pile, Franki pile, Beneto pile, Calweld, Reverse circulation method, etc., have been used for forming injection holes for concrete.
[0005] However, there have been problems such as unevenness of an inner peripheral surface of the concrete injection holes, which causes a position of the reinforced bars that are inserted or arranged therein to become irregular and uneven resulting in very low reliability of strength of the concrete pile deposited therein. For this reason, secure and reliable methods and devices for piling construction have been requested.
[0006] Therefore, there is a need in the art to provide a method and an apparatus for reinforcing concrete pile structures in which the reinforced bar is evenly sunk in the soft-ground earth.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0007] The pile apparatus of the present invention basically comprises a tube rod having duplicated tubes of concentric circles of large and small diameters, and a conical bit on which diamond shaped projections are formed. The above bit is vertically penetrated in the earth with vibration which is exerted during the concerned piling works. Reinforced concrete bars bundled into a desired shape, is charged into the earth through the space of the smaller diameter inner tube and kneaded concrete is supplied through an injection hose in the desired spot of the earth by vibration. Then, the above pile apparatus is drawn up slowly with vibration, and concrete, injected through the injection hose, fills up spaces and clearances between the projections and inner wall of the pile apparatus. Then, finally the reinforced bar inserted and charged into the earth, is evenly surrounded with homogeneous concrete, and finally it is planted in the solidified concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a perspective view of an embodiment of an concrete pile apparatus in accordance with the invention.
[0009] [0009]FIG. 2 is a cross sectional view of the concrete pile constructed in the earth, after solidification of concrete injected through an concrete injection hose of the invention.
[0010] [0010]FIG. 3 is a partial view of an opened state of triangle segments each having a triangular shape in the lowest end of the concrete pile apparatus in accordance with the invention.
[0011] [0011]FIG. 4 illustrates conically closing the bit and an end part of each segment which is engaged in the groove formed in the metallic weight at the lowest position of the bit.
[0012] [0012]FIG. 5 is a schematic sectional view of the inside of the bit of the present invention for explaining that each segment can be pivotally jointed and moved in the directions shown, and the reinforced bar is descended to the earth, and thereafter, concrete is injected through the injection hose into the soft ground earth.
[0013] [0013]FIG. 6 is a longitudinal section view of the concrete pile apparatus of the present invention, sunk by vibration of vibrators provided in the projections of the bit, which exerts vibrations successively during the work. This shows that the bit of the pile apparatus is in a closed state in the lowest position.
[0014] [0014]FIG. 7 is a schematic longitudinal section view prior to injection of the concrete through the injection hose. In this case, reinforced bars are inserted in the inner tube fixed in the inner wall of the outer tube of the tube rod, and also are penetrated in the soft-ground earth with vibration.
[0015] [0015]FIG. 8 is a schematic longitudinal section view which shows injecting and filling the concrete to spaces formed in the earth. Then, the apparatus is drawn up slowly soon after the injection of the concrete.
[0016] [0016]FIG. 9 is a schematic and longitudinal section view which shows that the pile apparatus is completely drawn up, and the reinforced bar remains in the solidified pile of the concrete formed in the earth.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The present invention is described in detail hereunder, referring to the embodiments illustrated in the attached drawings.
[0018] The present invention provides a reinforced bar concrete pile construction apparatus 1 that includes a tube rod 10 and a bit 30 as in FIG. 1, for forming a reinforced bar concrete pile CP. The apparatus will be herein referred to as simply the pile apparatus 1 . The bit 30 includes projections 32 that are radially protruding therefrom. The pile apparatus 1 includes a hollow spaced tube rod 10 on which a grooved channel 12 is inwardly and longitudinally formed along with the outer wall surface thereof. An inner tube 17 is concentrically fixed to an outer tube 11 of the same length, having lattices 18 connected and welded thereto. A concrete injection hose 13 is inserted in the grooved channel 12 and is movable upward and downward in the grooved channel 12 . A door plate 14 is pivotally hinge-jointed 15 for covering the grooved channel 12 and for retaining the injection hose 13 . Latches 16 are attached at the left side of the tip portion of the grooved channel 12 for opening and closing the door plate 14 over the channel 12 . The pile apparatus includes a hanger retaining channel tube 22 disposed between said tube rod 10 and said inner tube 17 inside which a hanger chain 2 a is connected to a coil spring 23 and a hook 24 . The hanger chain 2 a is moved like a rope up and down therein. The pile apparatus includes flanges 19 , 19 a having a plurality of through-holes (not shown) therein for bolting or securing the tube rod 10 and the bit 30 . An upper metal sheet cover 21 having pitted grooves 20 , and an inclined surface extends from the outer wall of the tube rod 10 . A lower metal sheet cover 21 a having pitted grooves 20 a and inclined surfaces extends from the outer wall 31 of the bit 30 .
[0019] The bit 30 defines a hollow space 30 a . The bit 30 on which the projections 32 are formed is to be assembled to the tube rod 10 by the flange fixing means previously described.
[0020] The projections 32 have inclined surfaces that create a symmetrically formed diamond-shape. The projections are positioned on the bit 30 and are symmetrically formed about the bit 30 . Vibrators 33 are included in an inner space of the projections 32 .
[0021] Triangle segments 34 have a triangular shape and are pivotally mounted to the outer wall 31 of the bit 30 by being hinge-jointed to the outer wall 31 of the bit 30 . The triangle segments 34 are attached adjacent to a lower peripheral portion 31 a of the bit 30 .
[0022] A metal weight 36 includes grooves 37 that are formed in the outer peripheral surface thereof. The metal weight 36 is connected to the hanger chain 2 a extending to the spring 23 of the hook 24 , for engaging and moving the above said triangle segments 34 at lower end portions of the triangle segments 34 .
[0023] As described above, the concrete pile apparatus 1 includes the hollow tube rod 10 as an upper part and the bit 30 as a lower part, and these parts are fastened and assembled by fastening means such as bolts 3 fastening the flanges 19 , 19 a of the tube rod 10 and the bit 30 .
[0024] The above tube rod 10 , as in FIG. 1 has the grooved channel 12 which is shaped and formed by drawing and shaping longitudinally, inwardly along with the outer peripheral wall of the tube rod 10 .
[0025] This grooved channel 12 securely embraces the concrete injection hose 13 as in FIG. 1 and FIG. 8. As in FIG. 1, the door plates 14 are placed on the outer peripheral wall of the tube rod 10 at left and right sides of a tip portion of the grooved channel 12 for covering the grooved channel 12 . The door plates 14 include hinge-joints 15 and latches 16 attached at right and left sides of the tip portion respectively and the door plates 14 are opened or closed by the latches 16 thereon. Inside the tube rod 10 , inner tube 17 having a small diameter than that of the outer tube 11 , and having both ends open, is concentrically fixed by the lattices 18 welded to the inner wall of the outer tube 11 of the tube rod 10 .
[0026] On the outer peripheral wall of the lowest portion of the tube rod, the flange 19 having through-holes for fastening the bolts 3 therein, is provided with the pitted grooves 20 in which a spanner for fastening the bolts, can be used. The upper steel cover 21 is attached with some gradient, to the tube rod 10 , and an end portion of the flange 19 a secured to flange 19 is fixed and engaged with that of the bit 30 .
[0027] On the outer peripheral wall 31 of the bit 30 , projections 32 (there are four projections as an example in FIG. 1) having four inclined surfaces, like diamond-shapes, on the outer wall of the bit, are formed. Each projection 32 thereon is radially protruded for forming a homogeneous structure of the concrete pile in the earth 41 . This pile apparatus in which the bit 30 is installed in the lower end of the tube rod 10 , is descended and piled in the earth, by vibration generated by the vibrators 33 .
[0028] A reinforced concrete bar structure 40 is descended through the inner tube 17 of the pile apparatus 1 , settled in the earth and then, concrete is injected through an injection hose 13 accompanied by continuous vibration, so that concrete is homogeneously mixed and filled in the space of the soft-ground earth created by exertion of the projections 32 having vibrators 33 therein, then the pile apparatus 1 is drawn up from the earth.
[0029] At a lower tip portion of the bit 30 , the triangle segments 34 are positioned in a closed state as shown in FIG. 6 and FIG. 7 when the lower end portions of the triangle segments 34 are engaged in the grooves 37 of the metallic weight 36 thereby forming a conical shaped lower tip portion. The triangle segments 34 can also be positioned in an opened state as shown in FIG. 5 and FIG. 8 when released from the grooves 37 of the metallic weight 36 .
[0030] Each triangle segment 34 that is hinge-jointed to the outer wall 31 of the bit 30 and engaged in the grooves 37 of the metallic weight 36 in the closed state, pivotally moves when opened to the opened state. The triangle segments 34 are released from the metallic weight 36 and swing toward a side wall of the bit 30 when the reinforced bar structure 40 descends downward and engages the triangle segments 34 and the hanging hook 24 is removed from the tube rod 10 . This action releases the tension from the hanging chain 2 a.
[0031] The triangle segments 34 can be released from the grooves 37 of the metallic weight 36 in a number of ways. The hanger chain 2 a is connected to the metallic weight 36 . Therefore, it is important to release the tension in the hanger chain 2 a or force the triangle segments 34 from the grooves 37 to release the triangle segments 34 from the metallic weight 36 . In another manner, the reinforced bar structure 40 could be lowered and load the triangle segments 34 thereby pulling the hanger chain 2 a downward until the triangle segments 34 are released without removing the hanging hook 24 . The reinforced bar structure 40 could also be in place and the triangle segments 34 released as the pile apparatus 1 is ascended upward in much the same manner as previously described. Furthermore, the hanging hook 24 can be removed from the tube rod 10 and slack provided in the hanger chain 2 a such that when the pile apparatus 1 ascends, the triangle segments 34 are released by gravity and pivot toward the side. In addition, it should be appreciated that any combination or variation of these methods could be used and the manner in which the metallic weight 36 is not intended to limit the present invention.
[0032] Here, after release of the triangle segments 34 , each segment 34 moves to the side wall in the direction shown in FIG. 5 and the hanging hook 24 is moved upward again for its hanging in the upper end of the tube rod 10 , and the metallic weight 36 is engaged upward in the end of the channel tube 22 , by restored elastic power of the coil spring connected to the hanger chain 2 a . Thus, the overall structure of the preferred embodiment of the concrete pile apparatus for movement of the soft-ground earth is described.
[0033] Before practicing concrete pile construction work by the pile apparatus 1 of the present invention, the bit 30 is selected for its diameter and assembled to the tube rod 10 which is suspended by a hanger 2 connected crane, which is done by matching the lower flange 19 a of the bit 30 and the upper flange 19 of the tube rod 10 by bolting in the pitted grooves 20 , 20 a.
[0034] The above pile apparatus 1 is to be fully penetrated in the soft-ground earth by driving or descending the pile apparatus 1 to a target level. When it penetrates down to the target level, then the reinforced bar structure 40 of which the bars are bundled with the same length to that of the concrete pile, is charged into the inner tube 17 . Then, it is to be positioned at the bottom of the soft-ground earth from the inner peripheral surface of the inner tube 17 .
[0035] After settlement of the reinforced concrete bar, then concrete is injected with vibration of vibrator 33 and successive vibration is offered on the tube rod 10 and on the bit 30 , and continues when drawing up the apparatus. In this case, the triangle segments 34 are rotatably moved sideward prior to the above operation, and the hanger chain 2 a is drawn upward through the hanger retaining tube 22 and also the metallic weight 36 is drawn up, as shown in FIG. 8.
[0036] After drawing up the pile apparatus, the hanging hook 24 is manually released from the upper end of the tube rod 10 and the hanger chain 2 a is drawn downward and the triangle segments 34 are again engaged in the grooves 37 of the metallic weight 36 to be ready to start piling work.
[0037] When the triangle segments 34 are moved from the closed state to the opened state, concrete is discharged through the injection hose 13 and filled in spaces of the soft-ground created by the diamond-shaped projections 32 formed on the outer peripheral surface of the bit 30 and connected to an inner space of the earth created by the remaining portions of the piling apparatus 1 .
[0038] The tube rod 10 of the pile apparatus 1 , inner tube 17 and the bit 30 , is then ascended or drawn upward, and the reinforced bar structure 40 in the inner tube 17 , remains in the inner space of the earth. The concrete C is then discharged from the bit, filled and stamped with vibration in the spaces in the soft-ground earth. In this manner, as illustrated in FIG. 9, the pile apparatus 1 which slowly ascends upward creates a homogeneous concrete pile in which the reinforced bar remains. After the pile apparatus 1 is removed, the reinforced bar concrete pile CP thus formed includes a circular column 40 , and multiple columns of radial protrusions which have smooth and homogeneous load distribution in the pile structure.
[0039] According to the present invention, very homogeneous, secure and strong concrete pile structures, may be obtained and constructed with secured reinforced bars, and stamping of the concrete effected by vibration, may minimize gap and offer fineness and finally enable a strong pile structure.
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The present invention relates to a concrete pile construction method and an apparatus used for improving soft earth ground by constructing reinforced bar concrete pile structures in the earth. The purpose of the present invention is to provide a process for securing firm concrete piles having a reinforced bar core with uniform concrete by means of a pile apparatus in which projections are radially formed and a conical-shaped bit is formed pointedly on said pile apparatus.
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BACKGROUND OF THE INVENTION
This invention relates to a synergistic surfactant composition formed by combining an alkylbenzenesulfonate anionic surfactant with at least one organic zwitterionic functional silicone zwitterionic surfactant represented by the formula:
Me.sub.3 SiO[SiMe.sub.2 O].sub.x [SiMeR.sup.1 O].sub.y SiMe.sub.3
and wherein:
Me=methyl;
R 1 =CH 2 CH 2 CH 2 N + (R 2 ) 2 (CH 2 ) z SO 3 - ;
R 2 =methyl or ethyl;
x=0-3;
y=1-2; and
z=3-4.
More particularly, the zwitterionic surfactants are represented by the following formulas: ##STR2##
A surfactant is a compound that reduces surface tension when dissolved in a liquid decreasing the attractive force exerted by molecules below the surface of the liquid upon those molecules at the surface of the liquid enabling the liquid to flow more readily. Liquids with low surface tensions flow more readily than water, while mercury with the highest surface tension of any liquid does not flow but disintegrates into droplets.
Surfactants exhibit combinations of cleaning, detergency, foaming, wetting, emulsifying, solubilizing, and dispersing properties. They are classified depending upon the charge of the surface active moiety, usually the larger part of the molecule. In anionic surfactants, the moiety carries a negative charge as in soap. In cationic surfactants, the charge is positive. In non-ionic surfactants, there is no charge on the molecule, and in amphoteric surfactants, solubilization is provided by the presence of positive and negative charges in the molecule.
Zwitterionic surfactants of the type disclosed herein are generally considered specialty surfactants. They do not irritate skin and eyes, and exhibit good surfactant properties over a wide pH range. This category of surfactant is compatible with anionic, cationic, and nonionic surfactants, and the use of these amphoteric surfactants ranges from detergents, emulsifiers, wetting and hair conditioning agents, foaming agents, fabric softeners, to anti-static agents. In cosmetic formulations, certain specialized zwitterionic surfactants reduce eye irritation caused by sulfate and sulfonate surfactants present in such products.
In U.S. Pat. No. 3,562,786, issued Feb. 9, 1971, to Bailey et al, there is disclosed the broad concept of blending organic surfactants with silicone-glycol type surfactants in order to achieve a synergy. The surfactants in Bailey et al, however, are generally considered to be of the standard non-ionic silicone type, rather than amphoteric, as in the present invention. Thus, in contrast to Bailey et al, the present invention blends organic surfactants with a new class of silicone sulfobetaine zwitterionic surfactants in order to achieve a synergistic effect. The sulfobetaine surfactants of the present invention, because they are a new class of silicone surfactant, possess advantages not inherent in Bailey et al. For example, one would not expect a zwitterionic surfactant to perform in the same fashion as a non-ionic surfactant as in Bailey et al because of the differences in the charged natures of the two categories of surfactants. Further, the zwitterionic surfactants of the present invention are solids and have a low water solubility in comparison to the Bailey et al liquid surfactants which are very water soluble. In addition, the zwitterionic surfactants of the present invention possess much lower critical micelle concentrations than the non-ionic surfactants in Bailey et al.
Such disadvantages of the prior art are overcome with the present invention wherein not only is a new class of silicone surfactant disclosed but a surfactant that possesses synergistic properties when combined with organic surfactants.
SUMMARY OF THE INVENTION
This invention relates to a synergistic surfactant composition comprising an alkylbenzenesulfonate anionic surfactant and at least one zwitterionic organofunctional siloxane zwitterionic surfactant.
This invention also relates to a synergistic surfactant compositions comprising a linear alkylate sulfonate anionic surfactant and at least one silicone sulfobetaine zwitterionic surfactant.
This invention further relates to a synergistic surfactant composition comprising an alkylbenzenesulfonate anionic surfactant and at least one organic zwitterionic functional silicone-zwitterionic surfactant represented by the formula:
Me.sub.3 SiO[SiMe.sub.2 O].sub.x [SiMeR.sup.1 O].sub.y SiMe.sub.3
and wherein:
Me=methyl;
R 1 =CH 2 CH 2 CH 2 N(R 2 ) 2 (CH 2 ) z SO 3 - ;
R 2 =methyl or ethyl;
x=0-3;
y=1-2; and
z=3-4.
This invention still further relates to a synergistic surfactant composition comprising sodium dodecylbenzenesulfonate anionic surfactant and at least one organic zwitterionic functional silicone zwitterionic surfactant represented by the formula:
Me.sub.3 SiO[SiMe.sub.2 O].sub.x [SiMeR.sup.1 O].sub.y SiMe.sub.3
and wherein:
Me=methyl;
R 1 =CH 2 CH 2 CH 2 N(R 2 ) 2 (CH 2 ) z SO 3 -1 ;
R 2 =methyl or ethyl;
x=0-3;
y=1-2; and
z=3-4.
The zwitterionic surfactant is a compound having the formula: ##STR3##
It is therefore an object of the present invention to provide a synergistic surfactant composition comprising an alkylbenzenesulfonate anionic surfactant and at least one organic zwitterionic functional silicone zwitterionic surfactant represented by the formula:
Me.sub.3 SiO[SiMe.sub.2 O].sub.x [SiMeR.sup.1 O].sub.y SiMe.sub.3
and wherein:
Me=methyl;
R 1 =CH 2 CH 2 CH 2 N(R 2 ) 2 (CH 2 ) z SO 3 - ;
R 2 =methyl or ethyl;
x=0-3;
y=1-2; and
z=3-4
and wherein the zwitterionic surfactants are represented by the following formulas: ##STR4##
It is another object of the present invention to provide a method of reducing the surface tension of an aqueous solution by adding to the aqueous solution an effective amount of a synergistic surfactant composition comprising sodium dodecylbenzenesulfonate anionic surfactant and at least one organic zwitterionic functional silicone zwitterionic surfactant represented by the formula:
Me.sub.3 SiO[SiMe.sub.2 O].sub.x [SiMeR.sup.1 O].sub.y SiMe.sub.3
and wherein:
Me=methyl;
R 1 =CH 2 CH 2 CH 2 N(R 2 ) 2 (CH 2 ) z SO 3 -1 ;
R 2 =methyl or ethyl;
x=0-3;
y=1-2; and
z=3-4
whereby the surface tension of the aqueous solution is lower than if either of the anionic surfactant and the zwitterionic surfactant were present in the aqueous solution individually.
These and other features, objects, and advantages of the present invention will become apparent from the following detailed description wherein reference is made to the several figures in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical representation illustrating the effects on equilibrium surface tension of combining one of the zwitterionic surfactants of the present invention with an anionic surfactant.
FIG. 2 is another graphical representation illustrating the effects on equilibrium surface tension of combining another of the zwitterionic surfactants of the present invention with an anionic surfactant.
FIG. 3 is a graphical representation illustrating the effects on dynamic surface tension of combining the zwitterionic surfactant of FIG. 1 with an anionic surfactant at a slow bubble evolution, and
FIG. 4 is a graphical representation illustrating the effects on dynamic surface tension of combining the zwitterionic surfactant of FIG. 1 with an anionic surfactant at a fast bubble evolution.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, silicone sulfobetaine surfactants have been found to behave synergistically in terms of surface tension reduction when used in combination with an alkylbenzenesulfonate such as sodium dodecylbenzenesulfonate. It has been determined experimentally, that the surface tension of an aqueous solution containing a silicone sulfobetaine surfactant together with the alkylbenzenesulfonate is lower than if the aqueous solution contained only one of the ingredients individually. Data were obtained relating to both the equilibrium surface tension as well as the dynamic surface tension. A DuNouy ring tensiometer was used to generate equilibrium surface tension data, whereas the dynamic surface tension data were obtained by a procedure which is a refinement of the standard maximum bubble pressure method with the aid of a SensaDyne 5000 surface tensiometer manufactured by CHEM-DYNE Research Corporation, Madison, Wis.
The experimental data has been set forth graphically in the form of FIGS. 1-4 as seen in the accompanying drawings in order to better facilitate an understanding of the present invention. It should be noted that FIGS. 1, 3, and 4, pertain to the zwitterionic surfactant represented by Formula 1, whereas FIG. 2 pertains to the zwitterionic surfactant represented by Formula 2. Further, FIGS. 1 and 2 portray equilibrium surface tension data, whereas FIGS. 3 and 4 portray dynamic surface tension data.
Specifically, FIG. 1 shows the effects of blending the surfactant represented by Formula 1 with linear sodium dodecylbenzenesulfonate. This figure depicts the relationship between equilibrium surface tension and a series of blends of the Formula 1 surfactant with the sulfonate surfactant. The blends range from pure sodium dodecylbenzenesulfonate anionic surfactant to pure zwitterionic surfactant represented by Formula 1. As noted above, the equilibrium surface tension data were generated by employing a DuNouy ring tensiometer in accordance with the method described in ASTM D1331-54-T.
The surface tension data for the various blends were obtained by utilizing solutions containing 0.1% of the blend of the anionic and zwitterionic surfactants. Hence, a 0.0% silicone sample was in actuality a 0.1% solution of the anionic surfactant. A 50% silicone sample contained 0.05% of the zwitterionic surfactant and 0.05% of the anionic surfactant. The 100% silicone sample was equivalent to 0.1% zwitterionic surfactant. FIG. 1 therefore shows the relationship that exists between the surface tension versus the percentage of silicone in the blend. The figure in addition illustrates what the surface tension would be in the event that only the individual surfactants were present at the effective concentrations of the blend.
An examination of FIG. 1 reveals that a synergistic effect is achieved by blending the linear sodium dodecylbenzenesulfonate anionic surfactant with the silicone sulfobetaine zwitterionic surfactant represented by Formula 1. It should be noted that throughout the range, the surface tension of the blend is lower than the surface tension exhibited by either of the two components individually. For example, the surface tension of a 0.1% solution of a 10/90 blend of the two surfactants can be seen to be 28.34 dynes/cm. The effective concentration of silicone sulfobetaine zwitterionic surfactant in such blend (0.01%) yields a surface tension value of 38.73 dynes/cm. Similarly, the effective concentration of the anionic surfactant (0.09%) provides a surface tension value of 43 dynes/cm. A synergy of 10.39 dyne/cm was therefore achieved by employing a blending of each of the two materials rather than using them individually. The synergistic effect, it should be noted, begins to diminish in the event that the blend of the anionic surfactant and the zwitterionic surfactant contains less than about 5% and more than about 15% silicone sulfobetaine zwitterionic surfactant.
FIG. 2 is similar to FIG. 1 except that the zwitterionic surfactant represented by Formula 2 was employed, otherwise the procedures noted above with respect to FIG. 1 are the same in FIG. 2. In FIG. 2, the synergistic effect is not as pronounced as is illustrated in FIG. 1, yet the synergistic effect in FIG. 2 is still apparent. Thus, a 0.1% solution of a 5/95 blend of the anionic surfactant with the zwitterionic surfactant represented by Formula 2 yielded a surface tension of 37.64 dynes/cm. By way of comparison, the effective concentration employing the zwitterionic surfactant alone yielded a surface tension of about 52 dynes/cm, whereas the effective concentration utilizing only the anionic surfactant provided a surface tension of 41.5 dynes/cm. Thus, there can be seen a synergistic effect in the amount of 3.86 dynes/cm.
With reference to FIGS. 3 and 4, there is illustrated therein the response of the surfactants of the present invention to dynamic surface tension measurements. Dynamic surface tension is a second measure of surface activity, and measures the surface energy of the test fluid and the speed of surfactant migration. As noted above, dynamic surface tension is measured utilizing the maximum bubble pressure method with a SensaDyne 5000 surface tensiometer. This instrument measures surface tension by determining the force required to blow bubbles from an orifice and into the test solution. Thus, a low surface energy fluid requires less energy to force a bubble out of the orifice than does a fluid of high surface energy. The speed of surfactant migration, however, is determined by changing the speed of the evolution of the bubbles. With a slow bubble rate, the surfactants have more time to reach the bubble-liquid interface and to orient in order to reduce the surface energy at the interface. With a fast bubble rate, the surfactants have less time to reach the newly formed bubble before the bubble is forced from the orifice. Hence, the surface energy for the fast rate is higher than the surface energy for the slow rate. In the instrument itself, a process gas such as dry nitrogen or clean dry air, is bubbled through two tubes of different diameter that are immersed in the fluid being tested. At each orifice, a bubble is formed in a controlled manner until the bubble reaches a maximum value where it breaks off rising to the surface of the test fluid. Since the two orifices differ in diameter, the two bubbles differ in maximum size and in the maximum pressure required to expand each bubble. This differential pressure is sensed by a transducer and the resulting output signal is used to measure dynamic surface tension directly.
The foregoing technique was used in order to determine the dynamic surface tension of blends of the zwitterionic surfactant represented by Formula 1 and the anionic surfactant sodium dodecylbenzenesulfonate, and the results are graphically represented in FIGS. 3 and 4. Blends were prepared of the anionic and the zwitterionic surfactants ranging from 100% of sodium dodecylbenzenesulfonate to 100% of the silicone sulfobetaine surfactant represented by Formula 1. The various blends were tested at concentrations of 0.1%. Evaluations of the blends was made on the SensaDyne 5000 tensiometer, with such evaluations being conducted at a low bubble speed and at a high bubble speed. Data from the tests was then plotted graphically and represented as FIGS. 3 and 4 in order to show the synergistic effects of employing both materials in comparison to using either individually.
Specifically, in FIG. 3 there will be seen the relationship between surface tension and percentage of silicone in the blend, and at a slow bubble evolution rate. The concentation of the blends evaluated was 0.1%, and the surface tension of the various blends was compared to the surface tension of the individual components at the effective concentration of the blend. FIG. 3 clearly reveals that the combination of the two surfactants is far superior to either of the surfactants when employed individually. Thus, the surface tension of the blend is lower than the surface tension of the individual components at any blend ratio. FIG. 4 covers the same concept as FIG. 3 except that in FIG. 4 the surface tension was measured at a fast bubble rate of evolution. The effect of the fast bubble rate in FIG. 4 in comparison to the slow bubble rate in FIG. 3 is that the surface tension values in FIG. 4 are higher than the surface tension values computed for FIG. 3. However, even at the fast bubble rate in FIG. 4, the synergistic effect is still apparent at blend ratios greater than 10/90. Therefore, the foregoing data is represented by FIGS. 1-4 clearly shows that blends of silicone sulfobetaines with linear dodecylbenzenesulfonates exhibit properties superior than if either material was used individually. The synergistic effect is also apparent for both the equilibrium surface tension as well as the dynamic surface tension measured.
The compounds of the present invention, more particularly the zwitterionic organofunctional siloxanes represented by Formulas 1 and 2, for example, are prepared by the quaternization of precursor aminofunctional siloxanes with either cyclic propane sultone or cyclic butane sultone. Specifically, these silicone sulfobetaines are prepared by a two-step process as set forth below: ##STR5## where Me=methyl;
x=0-3;
y=1, 2;
R=methyl or ethyl; and
n=3, 4.
These types of compounds are colorless solids and are non-toxic and useful as organic surfactant enhancers. They have been found to be particularly useful in order to enhance detergent surfactants, in liquid detergents, cleaners, automatic dishwashing detergents, and in powdered detergents for washing machines. Details of the synthesis of these materials are set forth in a copending U.S. patent application Ser. No. 07-004,734, of William N. Fenton et al, filed Jan. 20, 1987, and assigned to the same assignee as the present case, and reference may be had thereto.
It will be apparent from the foregoing that many other variations and modifications may be made in the structures, compounds, compositions, and methods described herein without departing substantially from the essential concepts of the present invention. Accordingly, it should be clearly understood that the forms of the invention described herein and depicted in the accompanying drawings are exemplary only and are not intended as limitations on the scope of the present invention.
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A synergistic surfactant composition comprising an alkylbenzenesulfonate anionic surfactant and at least one organic zwitterionic functional silicone zwitterionic surfactant represented by the formula:
Me.sub.3 SiO[SiMe.sub.2 O].sub.x [SiMeR.sup.1 O].sub.y SiMe.sub.3
and wherein:
R 1 =CH 2 CH 2 CH 2 N(R 2 ) 2 (CH 2 ) z SO 3 -
R 2 =methyl or ethyl
x=0-3
Y=1-2, and
z=3-4.
The particular zwitterionic surfactants are represented by the following formulas: ##STR1##
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TECHNICAL FIELD
[0001] The present invention relates to portable electric lamps, and in particular to a headlamp having an improved control of the geometry of the light beam.
BACKGROUND
[0002] The Applicant of the present application has contributed significantly to the development of new portable lamps, improving comfort and lighting of their users in all is kind of sports situations (caving, climbing, jogging, etc...) or professional (rescue, pruning, mine etc . . . )
[0003] In French patent application FR2893811 filed Nov. 21, 2005, the Applicant has proposed a portable electric lamp as shown in FIG. 1 , including at least two light sources with distinct beams—respectively narrow/long and wide/short—respectively generated by a central light source 1 d and an annular light source 1e. Combining their respective beams by means of a single control allows the generation of an effect of “zooming.” This effect of “zoom” remains fairly limited with a relative variation of the beam angle. Furthermore , this embodiment requires two separate sources of light, which can significantly increase the manufacturing costs and also the size of the light source. Finally, and this was not the least annoying inconvenience, in order to have a homogeneous light output , it is necessary that the light sources are perfectly matched, which can be difficult. And even more, when considering that, in general, LEDs have different aging profiles causing very quickly a loss of homogeneity in the production of the respective luminous fluxes of the two (or more) LED lamps, thus reducing the effectiveness of the “zooming” effect being searched.
SUMMARY
[0004] The invention solves a number of problems. One solved problem is the opportunity to integrate the zoom effect in the “dynamic” or “reactive” lighting invented by the Applicant of the present application. Indeed, in application WO2009/133309, the Applicant has invented the so-called concept of “dynamic lighting” or “reactive lighting” which, briefly and as shown in FIG. 2 , is based on a headlamp comprising at least one light emitting diode 11 (LED) and an optical sensor 14 located in its vicinity for sensing a signal representative of the light reflected by the surface of an object 16 being illuminated by the lamp. A control circuit 13 processes this signal so as to automatically control the power of the LED according to a predetermined threshold. In this manner, automatic control of the light beam emitted by the lamp is achieved is without further manual action so as to adjust the lighting to the environment, while also optimizing the power consumption and the life of the battery. If the principle of this “dynamic” lighting undeniably is a significant advance in the field of headlamps and more generally of the portable lighting, however, it remains necessary to combine this light with a powerful zoom effect, allowing constant effective and flexible adaptation of the illumination in accordance with the lighting conditions.
[0005] Moreover finally, in the international patent application WO2012/119756, the Applicant has introduced a headlamp with a variable geometry beam device controlled by an analysis of an image generated by an image sensor. For such a highly sophisticated lamp, it also appears desirable to have a “zoom” allowing the control of the geometry of the light beam that is particularly efficient and flexible to greatly benefit the possibilities offered by this new lamp technology .
[0006] It can thus be seen that there is still a wish for an effective and flexible mechanism for controlling the beam geometry and which allows easy and effective integration into the latest portable lamp technologies, and especially the so-called “dynamic” lighting lamp. In addition, it is desirable to provide an effective solution to problems of space, cost and finally the problem of aging of the light sources.
[0007] The present invention proposes to significantly improve this situation by achieving a new device for controlling the geometry of the beam which is perfectly suited to the new requirements introduced with the new facilities offered by modern headlamps.
[0008] It is an object of the present invention to carry out a portable lamp structure, such as a headlamp, allowing easier control of the geometry of the light beam.
[0009] It is another object of the present invention to provide a device for controlling the geometry of the beam generated by a portable lamp, reducing manufacturing costs but also the lamp clutter.
[0010] It is still another object of the present invention to provide a portable lamp device enabling fine control of the geometry of the beam and adapted to dynamic lighting.
[0011] The invention achieves these objects by means of a portable electric lamp, such as a headlamp, comprising:
a light source generating at least one light beam generates a narrow beam; a panel arranged in front of said light source, said panel having an electric-optical diffusion device controlled by an electric signal for producing an electrically adjustable diffusion,
[0014] so as to generate a light beam of variable geometry from the single narrow beam.
[0015] The electro-optical device may be a liquid crystal diffuser controlled either by a current or by a control voltage.
[0016] In one embodiment, the panel consists of a Diffusion Polymer Liquid Cristal (DPLC) film through which passes said narrow beam, the DPLC film comprising biasing electrodes for receiving a control voltage for controlling the transparency of said film.
[0017] Preferably, the portable lamp includes:
a light source comprising at least one LED generating a narrow beam; a source of power for powering the LEDs; a control unit for generating a control potential for controlling the transparency of said DPLC film.
[0021] In a particular embodiment, the control voltage is generated from a manually controlled actuator.
[0022] Alternatively, the control voltage is generated from an information generated by a sensor sensing a fraction of the light being reflected on an object illuminated by the beam.
[0023] Alternatively, the control voltage is generated from an information generated by an accelerometer sensor, allowing the control of lamp lighting as the user is running or jogging.
[0024] In a particular embodiment, the control voltage is generated from an information generated by an image sensor.
[0025] More specifically, the portable lamp comprises communication means for receiving a control information which can be used for deriving the adjustable transparency control potential. This information can come from either another lamp—being interconnected and which may be configured in master mode—or from a data processing device such as a mobile phone, tablet etc .. which may also be used for controlling the features of the portable lamp.
[0026] In a specific embodiment, the portable lamp is particularly suitable for producing a headlamp.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Other features of one or more embodiments of the invention will appear from the following description of embodiments of the invention, with reference being made to the accompanying drawings.
[0028] FIG. 1 illustrates the principle of a conventional lamp fitted with an “electric zoom” facility.
[0029] FIG. 2 represents the general principle of a conventional lamp fitted with the so-called “dynamic lighting”.
[0030] FIG. 3 illustrates a first preferred embodiment of a portable lamp comprising is an electrically adjustable transparent glazing.
[0031] FIG. 4 illustrates a second embodiment combining an electro-optical diffuser with dynamic lighting lamp.
[0032] FIG. 5 illustrates a third embodiment of a portable lamp comprising an accelerometer used for generating the control potential of the electro-optical diffuser.
[0033] FIG. 6 shows a fourth embodiment of a portable lamp comprising an image sensor and an image processor for generating a control information for generating the control potential of the electric optical diffuser .
[0034] FIG. 7 shows a fifth embodiment of a portable lamp comprising communication means for receiving information for generating the control potential of the electro-optical diffuser.
DESCRIPTION
[0035] There will now be described, in relation to FIG. 3 , a particular embodiment of a lamp, such as a headlamp generating a light beam, and provided with an improved device for controlling the geometry of the light beam.
[0036] The lamp includes a light source 31 which produces a light beam 31 generated for example by means of one or more LED(s). The light source 31 may be provided with a primary optics for providing first collimating so as to allow the formation of a rather narrow beam.
[0037] Optionally, a secondary optics 32 may be provided to improve, as necessary, the collimation of the source and thus increase, as appropriate, the narrow beam geometry.
[0038] The lamp furthermore has an electro-optical device 33 disposed in front of the light source, such as an electro-optical diffuser allowing electrical control transparency/opacity, so as to control the geometry of the light beam generated by the LED or (s).
[0039] Preferably the electro-optical device 33 is made of a panel of Diffusion Polymer
[0040] Liquid Cristal (DPLC) film (Liquid crystals dispersed in polymer or polymer dispersive liquid crystal) which, as known by a skilled man, consists of a particular implementation of crystals liquid heterogeneous dispersion in a polymer matrix.
[0041] This DPLC film may advantageously replace the glass conventionally disposed in front of the light source and protecting the latter, and which comprises two biasing terminals 34 and 35 receiving a control signal, for example a control voltage Vc generated by a control unit 36 .
[0042] Thus, one can achieve an advantageous combination of a specifically narrow light source and an electro-optical DPLC diffuser which can be electrically controlled so as to generate light beams various shapes of light beams, since the narrowest beam (when the film DPLC is completely transparent) to a maximum diffusion providing light scattering in all directions, as illustrated in FIG. 3 .
[0043] With this particularly advantageous arrangement, it is thus possible to generate, by means of a single narrow beam light source, for example less than 10 degrees, a large variety of angles or beamwidths. The portable lamp can therefore ensure new features (floodlight—lantern—dawn simulator alarm).
[0044] And these new features will be permitted while significantly reducing the size of the lamp since, in the best case, only one single LED will be required to produce a wide variety of light beams.
[0045] Furthermore, the problem of matching the LEDs and their profiles aging is also solved since one single LED can be used for generating a plurality of beams which always present an homogenous color.
[0046] The invention can thus be used for effectively solving quite a number of problems arising in the development of an ‘electrically controlled zoom’.
[0047] One can further note an aesthetic advantage since, in the absence of any control voltage Vc and when the lamp is switched off, the latter is fully grained and has, therefore, quite a nice appearance.
[0048] In one particularly simple embodiment, the control voltage Vc is controlled via a switch or a manual actuator which can be operated by the lamp user, which may thus set—as desired—the angle of the generated beam.
[0049] Alternatively—and this shows the great flexibility of the device being described—it will automatically adjust the potential Vc from various information data.
[0050] FIG. 4 illustrates a second embodiment of a lamp 100 , assumed to be a headlamp, which advantageously combines the use of an electro-optical diffuser in a “dynamic” or “reactive” type lamp.
[0051] The lamp 100 includes a power module 450 associated with a control module 400 and a light source 460 having one or more LED (s) which has/have, when appropriate, its/their own focal system (not shown in the figure).
[0052] In the example in FIG. 4 , one shows, for the sake of simplification, a single LED 460 which is powered by leads 461 being connected to power module 450 , which clearly represents the most compact embodiment.
[0053] However, where the compactness is critical, one can consider, particularly for the purpose of increasing the brightness of the lamp, to use several diodes into a single focal optical system, or even multiply the number of optical systems so as to increase the possibilities of use of the lamp. In particular, one can consider theh use of more imposing LEDs, for instance of the multi-chip type (Creates XLM 2 ) combined with the most impressive optics, enabling a more sophisticated embodiment.
[0054] In a specific embodiment, the powering of LED diode 460 —via leads 461 —is carried out under the control information or a control signal 401 generated by the control module 400 .
[0055] Power module 450 specifically includes all components that are conventionally found in an LED illumination lamp for producing a light beam of high intensity, and in general based on Pulse Width Modulation PWM, well known to the skilled man and similar to that known and used in class audio circuits D. The PWM modulation is controlled by the control signal 401 . Generally speaking, the term “signal” mentioned above refers to an electrical quantity—current or voltage—that can cause control of the power module 450 , including the PWM modulation used to supply power to the LED 460 . This is only one particular embodiment, with the understanding that it will be possible to substitute to “control signal 401 ” any “control information” such a logical information stored in a register and transmitted by any appropriate means to power module 450 in order to control the transmission power of the light beam. In one particular embodiment, we can even consider the two control modules 400 and power 450 are integrated within the same integrated circuit.
[0056] A skilled person can therefore easily understand that that when we refer to a “control signal 401 ” is indiscriminately encompasses embodiments using an electrical quantity control—current or voltage—and the embodiments in which the command is effected by means of a logic information transmitted within the power module 450 . For this reason, one will hereinafter indiscriminately use the wordings “control signal” or “control information”.
[0057] In general, switches and switching components that constitute power module 450 —which can be either bipolar transistors, FETs (Field Effect Transistor) or MOS (Metal Oxide Semiconductor) or MOSFET—are well known to a skilled man and the presentation will be deliberately reduced in this regard for brevity. Likewise, we invite the reader to refer to the general literature on various aspect of the PWM modulation.
[0058] As seen in FIG. 4 , control module 400 particularly comprises a sensor 410 having its own focal optical module, which is used for sensing a portion of the light being reflected on the illuminated object or zone, so as to generate an useful information for carrying out the so-called “dynamic” or “reactive” lighting .
[0059] The information produced by sensor 410 is processed by control module 400 so as to derive a control voltage Vc by means of appropriate logic and analog circuits. This control voltage Vc is transmitted via appropriate leads 471 to a DPLC film 470 so as to control the diffusion of the light beam passing through the latter.
[0060] More specifically, the diffusion control is such that, in the absence of any control voltage Vc, the diffusion of the DPLC film 470 is maximum, thus producing the light rays in all directions (shown by the beam 473 in FIG. 4 ). On the contrary, when control module 400 generates a significant control voltage Vc—in the order of 75 volts today but with the aim of lowering in the value of 24 volts—the DPLC film will show a perfect or almost full transparency, so that only a narrow beam 472 will be generated by the portable lamp.
[0061] With such a device, one can therefore automatically control the coefficient of diffusion of the DPLC film via control voltage Vc, and such control is derived from the reflection of light on an illuminated object sensed by sensor 410 .
[0062] One thus significantly improves the conventional “dynamic” or “reactive” lamp by integrating in the latter an electrically controllable DPLC film. More specifically, the io possibility of electrically controlling the electro-optical diffuser greatly simplifies the feedback loop allowing the control of the diffusion based on the light sensed by the sensor 410 .
[0063] This makes lamp 100 of FIG. 4 particularly flexible for quite a large number of control loops which can be used.
[0064] But this certainly does not exhaust the possibilities of the described embodiment, which can allow a wide variety of different controls, as this is illustrated in FIG. 5 , wherein all components identical to those of FIG. 4 retain their references. This device of FIG. 5 further includes a speed sensor or accelerometer sensor 420 which can be added, or substituted to sensor 410 . Such acceleromter sensor is particularly useful for detecting a situation where the lamp user makes significant moves, for instance if he is running, in which case, it can be useful to automatically control, through the control unit 400 , the generation of a narrower and stronger beam.
[0065] FIG. 6 shows another example of a more sophisticated embodiment in which the lamp includes an image processor 435 such as that described in patent application WO 2012/119756 dated Mar. 6, 2012, and allowing control of the geometry the beam from an image analysis performed by an image processor 435 shown in FIG. 6 . Such analysis of the image sensed leads, thanks to an appropriate image processing, to the generation of an control voltage Vc which can be used for controlling the diffusion factor of the DPLC film 470 . The reader is particularly invited to refer to the developments described in this patent application for carrying out such a particular portable lamp incorporating an image sensor.
[0066] FIG. 7 shows another embodiment wherein one adds, to the elements described in the embodiment of FIG. 4 , and which—for the sake of brevity—shall keep their reference numerals, a wireless communication unit 440 , and particularly transmission/reception circuits for receiving a control information from a device being external to the lamp, said information being used for generating the control voltage Vc for controlling the diffusion of the electro-optical diffusion device.
[0067] In a particular embodiment, the communication circuits may be Bluetooth or equivalent type and allow an exchange of information between two portable lamps so that a type of master/slave control between the two lamps.
[0068] It is thus possible, thanks to this arrangement to produce centralized control of the diffusion of the DPLC film.
[0069] Alternatively, the wireless communication circuits 440 are used for the exchange of data between the portable lamp and an external data processing device, such as a mobile phone or a touch pad 500 that will thus be able to take advantage of all the processing power available in these external devices, but also their communication capabilities. This allows control of the brightness of the beam but also its geometry thanks to the DPLC film 470 .
[0070] This arrangement can be particularly advantageous as it will become possible to use the computing power which is available in these external devices, as well as the extended communication facilities which are thus permitted, so as to achieve a fine and effective tuning of the beam geometry.
[0071] With this communication capability, quite a number of new facilities and possibilities may be considered for the headlamp.
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The invention relates to a portable electric lamp with a light source generating at least one light beam; and a pane of glass arranged in front of the light source. The pane of glass has an electro-optical diffusion device controlled by an electrical signal in order to generate electrically adjustable diffusion. This diffusion generates a light beam with variable geometry from the single narrow beam. This results in headlamps with improved control of the geometry of its lightbeams.
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FIELD OF THE INVENTION
This invention relates to a method of repairing potholes in road surfaces.
BACKGROUND OF THE INVENTION
Potholes are well known to those who travel paved roadways. Moreover, the unavoidable appearance of potholes in paved road surfaces is a continuous problem to those responsible for the maintenance of the nation's roadways. Potholes most commonly appear during the winter months and are caused by rapid changes in the temperature of the pavement which lead to the cracking of the road surfaces. The crack in the road surface then lends itself to the entry of water, which upon freezing results in the loss of hunks of pavement leaving potholes.
Potholes present a definite hazard. They frequently cause vehicles to swerve from their intended path when attempting to avoid them, and when a vehicle strikes a pothole, it may be deflected, causing the driver to lose control of his vehicle. Tire and automobile frame damage may be the costly result to car and truck owners when potholes are struck. Finally, the cost incurred by municipal, state or federal agencies in repairing potholes and maintaining a smooth road surface is significant. Considerable economic drain is imposed on the agencies responsible as a result of the costs they must pay in repairing potholes wherever paved roads are maintained. In fact, with the tightening of federal, state and local budgets, the coats for the prompt and permanent repair of potholes are becoming increasingly prohibitive.
The current methods for the permanent repair of potholes are expensive, time consuming and frequently result in traffic delays. In an attempt to minimize traffic delays and cost, most pothole repairs are temporary and involve no more than pouring a heated bituminous material into the pothole and compacting it down to a smooth surface.
One generally accepted method for the temporary filling of potholes comprises filling the pothole with an asphalt-concrete mix. The hole must be dried before the addition of the filler, and the asphalt-concrete mix subsequent to being applied to the pothole must be thoroughly compacted with either a pneumatic compactor, a vibratory plate compactor or a roller. This procedure is relatively expensive since it utilizes an expensive asphalt-concrete mixture which in turn requires expensive equipment to apply it. Moreover, there is a considerable amount of human labor associated with the repair of potholes by this method which further increases the cost of repair. In making a repair utilizing an asphalt-concrete filler a three-man crew is required--namely, a compactor operator, truck driver and a laborer to add the filler to the hole.
The prior art does not disclose a method of repairing potholes in road surfaces utilizing a relatively inexpensive material, which requires little or no preparation prior to use and requires a minimum of time and human labor to effectuate a road repair utilizing it.
The method of this invention employs a self-hardening mixture of fly ash and water to fill crevices or potholes in road surfaces. Fly ash is plentiful and cheap. In fact, fly ash is often viewed as an undesirable waste product resulting from the combustion of coal or other solid fossil fuels by electric utility plants.
In the past, attempts have been made to find commercial applications for fly ash. For example, fly ash has been used in the construction of highway embankments, roads, or as a component in concrete or asphalt formulations. In addition, fly ash has been utilized in the form of a grout to fill an abandoned sewer. See "Ash at Work--Process and Technical Data" NAA Summary Report (May-October 1975); Professional Engineer, pp. 18-22, July 1974; "How Fly Ash Improves Concrete Blocks, Ready-Mix Concrete, Concrete Pipe," Concrete Industries Year Book, pp. 1-6 (1970-1977). However, fly ash has not been utilized to fill potholes which result from the deterioration of conventional road surfaces comprised of, for example, asphalt, concrete, macadam or the like.
It is an object of this invention to provide a simple, quick and inexpensive method of filling potholes to restore a safe and long-lasting road surface.
It is a further object of this invention to provide a method of filling crevices in road surfaces employing a relatively inexpensive by-product material which, unlike conventional road fill materials, requires little or no preparation prior to use, and a minimum of human labor to effectuate road repairs utilizing it.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the foregoing objectives, the present invention provides a method for quickly and inexpensively filling a pothole. The method of this invention requires a minimum of human labor, and utilizes fly ash, a material which is generally viewed as a waste product, as the essential ingredient employed to repair the pothole. The pothole repair method of this invention comprises the steps of: (a) adding fly ash to a pothole which is filled with water, said fly ash being added in an amount sufficient to fill said pothole to a level which about equals the outermost surface of said road, and (b) said fly ash and water comprising a self-hardening mixture which upon drying hardens into a compact mass filling said pothole.
In another embodiment the present invention comprises a method for repairing potholes utilizing the fly ash by-product from a coal burning utility plant. The method comprises the steps of: (a) collecting fly ash produced by a coal burning utility plant in a container, wherein said fly ash is drawn into said container by vacuum means associated with said container, and wherein said container also has means for exhausting said fly ash from said container, (b) transporting said container to a pothole which is filled with water and exhausting said fly ash from said container and into said pothole, (c) said fly ash being added in an amount sufficient to fill said pothole to a level which about equals to the outermost surface of said road, and (d) said fly ash and water comprising a self-hardening mixture which upon drying hardens into a compact mass filling said pothole.
DETAILED DESCRIPTION OF THE INVENTION
Fly ash is a by-product material which is produced as a result of the combustion of a solid fuel. In particular, fly ash is the fine non-combustible particles of ash carried out of the solid fuel bed when it is combusted. The solid non-combustible material which remains in the fuel bed is referred to as bottom ash. One of the most common sources of fly ash is utility plants which burn powdered coal to produce electrical energy. After the coal has been combusted, there generally remains a 6% by weight ash residue of which 2% is bottom ash and 4% is fly ash. As an example, a 650 mgw plant at full load burns 600 tons of coal per hour, producing 24 tons of fly ash per hour.
Chemically, fly ash is a finely divided mineral product high in silica, aluminum and iron and significantly deficient in lime. Fly ash resulting from the combustion of one batch of coal or other solid fuel may differ in chemical composition from the fly ash produced from the combustion of a different batch of solid fuel. Thus detailed chemical analysis has shown that the fly ash by-product from one power station may differ in chemical composition from the fly ash produced at a different power plant. See P. T. Sherwood, M. D. Ryley, "The Use of Stabilized Pulverized Fuel Ash in Road Construction," Crowthorne Road Research Laboratory, RRL Report No. 49 (1966). However, chemical analysis shows the presence of the following metal oxides in the fly ash samples tested: SiO 2 , Al 2 O 3 , Fe 2 O 3 , CaO, MgO, K 2 O, Na 2 O and SO 3 .
A mixture of fly ash and water is known to harden into a solidified rock-hard mass. The ratio of water to fly ash in the mix is not critical since regardless of the quantity of water present, upon eavporization the component fly ash mass is produced. However, not all fly ash and water mixtures have the ability to self-harden into a solidified mass. The fly ash and water mixtures employed by this invention, however, are self-hardening mixtures which solidify upon drying.
The selection of a suitable fly ash is readily accomplished by testing the fly ash-water mixture for its ability to self-harden upon drying into a compact mass. This may be simply done by placing an approximately 1:1 mixture of fly ash and water in a glass vessel and allowing the mix to air dry. Fly ash suitable for use in this invention will harden into a solid mass. On the other hand, fly ash-water mixtures which do not self-harden upon evaporation of the water component are unsuitable for use in accordance with this invention.
As a further aid in selecting a fly ash sample to use, the hardened mass formed from the mix may be subjected to testing to determine its compressive strength in pounds per square inch. Preferably, the solidified fly ash employed has a compressive strength in the range of from about 2,050 to about 2,530 pounds per square inch.
Potholes frequently have a jagged interior structure of crevices and the like which may extend deep into the road bed, and even underneath the surface of the remaining portions of the road surface area about the pothole. As these underground crevices expand due to deterioration by water, ice, and the like, additional portions of the road surface about the pothole may cave in, and as a result the size of the pothole increases. Therefore, in order to properly fill a pothole, all crevices which extend from the pothole and under existing road surface areas should be filled.
Under the microscope most of the particles of fly ash are seen to be spherical in shape and glassy in appearance. When fly ash is introduced into a pothole which is filled with water, the fly ash material acts like minute ball bearings and flows into every interior crevice of the pothole. Thus, by the introduction of the fly ash into the pothole not only is the road crevice filled, but the danger of further road deterioration is also substantially reduced or eliminated. The ability of fly ash to flow like ball bearings into all of the internal crevices of a pothole contrasts sharply with other road fill materials such as the commonly used bituminous materials which are less malleable and which may leave sub-surface cavities within the pothole.
In accordance with one embodiment of the present invention fly ash is added to a pothole which is filled with water. As dry fly ash enters standing water, the particles flow very quickly downwardly eventually completely filling the pothole. A sufficient amount of fly ash is added to fill the pothole to the top of the hole and about even with the uppermost surface of the road. There is no need for the precise measurement of the mix. The excess water simply runs off as the fly ash reaches the top of the hole. As the wet fly ash reaches the level of the road surface, it may be desirable to mechanically smooth over the top layer of the fly ash fill with a trowel or shovel to insure a smooth road surface in the area of the repair.
While the hardening time may vary from fly ash sample to fly ash sample, fly ash has been observed to harden to a mass capable of supporting vehicular traffic within about fifteen minutes. Although a sufficient load bearing strength may be reached within about fifteen minutes, depending upon the size of the fly ash mass, the drying through of the water-fly ash mixture may continue for hours. Throughout the drying period traffic may proceed over the fly ash fill. Moreover, during the drying process, the surface of the fly ash will be compressed to a smooth top surface by the passage of vehicular traffic over it.
The water employed in combination with the fly ash may be the water which is frequently found, and naturally present in potholes. Alternatively water may be added to a dry pothole, or to supplement the water already in the pothole prior to the introduction of the dry fly ash. In any case the fly ash is preferably added to a pothole which is completely filled with water. The presence of excess water on top of the fly ash mass does not affect the hardening process.
An advantage associated with this method is the speed and simplicity with which a pothole repair can be accomplished. Equipment and personnel are required only for inserting the water (where necessary) and dry fly ash into the pothole, thereby eliminating the necessity for heating equipment, compaction equipment, etc., and the personnel to operate such equipment.
The method of this invention may be implemented using commonly available equipment. For example, a conventional truck or other vehicle may be employed to transport a drum or bag of dry fly ash as well as a shovel or other implement for introducing the fly ash into the pothole. The fly ash, of course, should be transported in a container which maintains it in a dry state. In addition, a water container having a hose or other means for introducing water, where necessary, into the pothole may be a necessary piece of equipment to complete the road repair. With this simple equipment, a single repairman can repair a pothole by adding water and fly ash to the pothole. As a final step in the repair process, the repairman may employ a shovel or trowel to smooth over the surface of the filled pothole. The entire repair can be completed within minutes.
In order to accomplish the rapid repair of a large number of potholes on a deteriorating road surface, a more automated method of repair may be employed. For this purpose a truck carrying a reversible vacuum container may be employed. Trucks having reversible vaccum containers are commercially available from W. W. Andress Co., Bergenfield, N.J.; and a trailer which carries a reversible vacuum container is commercially available from the D. P. Way Corp., Milwaukee, Wis.
More specifically, the truck first travels to the fly ash storage site, such as a coal burning utility plant, to receive a charge of dry fly ash which is stored in a containerized drum carried by the truck. The containerized drum should be equipped with a hose, and a reversible vaccum. At the fly ash storage site the vacuum is actuated to draw a charge of fly ash into the containerized drum carried by the truck. The truck then travels to the pothole site. If the pothole is already filled with water, the operator simply exhausts an amount of fly ash into the pothole sufficient to completely fill the pothole with fly ash. The operator may then smooth over the surface of the fly-ash-filled hole with a shovel or trowel, and quickly move onto the next pothole.
On the other hand if the pothole is not filled with water, the operator may employ a water supply carried by the repair vehicle to fill the pothole with water prior to the addition of the fly ash.
As an alternative to adding fly ash to a pothole to which water has been previously added, the fly ash and water may be added simultaneously to the pothole, or the fly ash may be added first and then the water. For example, in the repair vehicle described above, the water hose and the hose line which exhausts the fly ash may be joined by a Y-shaped joint such that a mixture of fly ash and water is simultaneously discharged by the vehicle.
Finally, the fly ash water mixture may be employed to partially or substantially fill the pothole, and a second road fill material may be employed to complete the repair. For example, the pothole may be filled to within about 21/2 inches of the uppermost road surface, and the repair may be completed by applying a top road surface of a conventional repair material such as asphalt, a concrete-asphalt mix, or the like.
EXAMPLE
Fly ash was obtained from a coal burning utility plant and one-inch cubes of the solidified fly ash and water mix were prepared. The compressive strength of the five samples was tested by a standard laboratory procedure employing a Baldwin-Emery Universal Testing Machine. The following results were obtained:
______________________________________Compressive Strength Compressive Area of Sample Breaking Load StrengthSample sq. in. lbs. (psi)______________________________________1 1.071 2,600 2,4302 1.107 2,800 2,5303 1.081 2,220 2,0504 1.009 2,400 2,3805 1.113 2,280 2,050Average 2,290______________________________________
The fly ash sample tested above to have an average compressive strength of 2,290 psi was employed to repair a pothole. As a first step, water was added to the pothole so as to completely fill the pothole with water. Dry fly ash was then added to the water in the pothole. The water flowed through the fly ash and filled every crevice in the pothole. Excess water and fly ash which overflowed the pothole was smoothed over with a shovel. Within fifteen minutes a smooth road surface in the area of the pothole was provided.
This invention has been described in terms of specific embodiments set forth in detail herein. It should be understood, however, that these are by way of illustration only and that the invention is not necessarily limited thereto. Modifications and variations will be apparent from this disclosure and may be resorted to without departing from the spirit of this invention, as those skilled in the art will readily understand. Accordingly, such variations and modifications of the disclosed embodiments are considered to be within the scope of this invention and the following claims.
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This application relates to a method for quickly and efficiently filling a pothole in a road surface, utilizing a mixture of fly ash and water which hardens into a compact mass capable of supporting vehicular traffic.
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[0001] This application claims priority from U.S. provisional patent application Ser. No. 60/852,863, entitled “Methods and Apparatus for Making Coatings Using. Ultrasonic Spray Deposition,” and filed on Oct. 19, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to methods and apparatus for making coatings and articles from various material compositions involving use of ultrasonic spray as the core method of coating deposition. Ultrasonic spray deposition produces coatings that are more dense, more uniform, and thinner than coatings produced using other methods. These coatings may be used for a variety of applications, including for example coatings for cutting tools where toughness and wear resistance are important and thing coatings are necessary, coatings for biomedical implants, and other applications where thin and niform coatings are needed.
SUMMARY OF THE INVENTION
[0003] In one embodiment of the present invention, ultrasonic spray deposition (USD) is used to deposit a base layer on the substrate, followed by chemical vapor infiltration (CVI) to introduce a binder phase that creates a composite coating with good adherence of the binder to the initial phase particles and adherence of the composite coating to the substrate. U.S. Pat. No. 6,607,782 issued Aug. 19, 2003 to Ajay P. Malshe, et al., disclosed a method that used electrostatic spray coating (ESC) to deposit the initial base layer, followed by CVI as the second step. The present invention, which uses USD followed by CVI as one embodiment, provides important advantages over the previously disclosed method, including:
Ability to produce more dense coatings—when the particles are dispersed in a liquid and sprayed using USD, with subsequent evaporation of the liquid, we have found that a much higher density of particles can be deposited on the substrate as compared to dry powder ESC; Greater uniformity and reduced surface roughness of the coatings—because nanoparticles dispersed in a properly-chosen liquid have a much reduced tendency to agglomerate, and because the USD process creates very small droplets of liquid dispersion that evaporate quickly during and following deposition, we found that the resulting coating exhibits much less agglomeration, and thus surface smoothness and uniformity of the coating are greatly enhanced; Ability to deposit thinner uniform coatings—with dry powder ESC, the minimum coating thickness tends to be in the range of 10 microns, while USD can produce uniform coatings that are as thin as one micron; and Ability to coat substrates that are not conductive (ESC requires that the surface of the substrate have a certain level of electrical conductivity—USD does not).
[0008] We have used this process to create coatings consisting of cubic boron nitride (cBN), deposited using USD, and titanium nitride (TiN) applied using CVI in various embodiments. This process can be used with many materials not usable with other processes, including nitrides, carbides, carbonitrides, borides, oxides, sulphides and silicides.
[0009] In addition, other binding or post-deposition treatment processes can be applied as alternatives to CVI, depending on the substrate, the coating materials, and the application requirements of the coating, in various embodiments. This invention is directed in various embodiments to multiple methods for creating coatings, comprised of a single material or multiple materials in combination, using USD as the process for initial deposition of a base or green coating. Coatings can be applied to a variety of substrates including those with complex geometries. The application also describes apparatus or equipment designs used to perform ultrasonic spray deposition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 illustrates the two-step coating process according to a preferred embodiment of the present invention, including an initial deposition of a base- or green-coating layer, followed by a post-deposition treatment step.
[0011] FIG. 2 shows the case in which a pre-deposition treatment is applied to the coating materials prior to deposition.
[0012] FIG. 3 illustrates an ultrasonic spray deposition process.
[0013] FIG. 4 shows ultrasonic spray deposition in combination with electrostatic charging.
[0014] FIG. 5 illustrates an ultrasonic tank used in feeding coating materials dispersed in a liquid to the ultrasonic deposition system.
[0015] FIG. 6 shows the deposition chamber used to contain the materials being deposited, preventing unacceptable release to the environment, allow for adjustment of spray nozzle to substrate distance, and capture and recycle unused coating materials.
[0016] FIG. 7 illustrates a rotating stage used to ensure uniform deposition of the coating on the substrate.
[0017] FIG. 8 shows the integrated ultrasonic spray deposition system including the ultrasonic pressure delivery system, and the deposition system including the chamber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Disclosed herein are methods and apparatus for producing a coating on a substrate, beginning with ultrasonic spray deposition to deposit a base coating layer.
Two-Step Coating Processes—Overview
[0019] FIG. 1 illustrates a two-step process for producing a coating on a substrate. The substrate 170 is placed in a deposition system 200 . One or more coating materials 150 are introduced into the deposition system 200 . These coating materials may be in dry powder or liquid suspension form, and may contain nano- or micro-sized particles or a combination of the two. Multiple materials may be combined together or introduced separately into the deposition system 200 . A variety of materials can be used, including nitrides, carbides, carbonitrides, borides, oxides, sulphides and silicides.
[0020] The deposition system 200 may use any of several methods to produce an initial coating or base layer on the substrate. One such deposition method is ultrasonic spray deposition (USD), described further below.
[0021] After the initial deposition step, dry solid particles of the coating material(s) are in contact with the substrate. The substrate with deposition 270 is the output of the deposition step 200 as illustrated in FIG. 1 .
[0022] The substrate 270 with deposition of a base layer then undergoes a post-deposition treatment step 300 . Post-deposition treatment is used to bind the deposited dry particles to one another and to the substrate. Suitable treatment methods include:
Chemical vapor infiltration (CVI), which is similar to chemical vapor deposition (CVD) but using a slower reaction rate such that the binder infiltrates the porous dry powder deposition, coming into contact with both the substrate and the dry particles Sintering, using any of several alternative sintering methods, singly or in combination, including:
Microwave sintering Laser sintering Infrared sintering
[0028] Each of these methods applies one or more short bursts of high energy (microwave, laser, infrared, or high temperature and high pressure) to sinter the particles of the initial coating deposition, binding them to each other and to the substrate. These methods can allow binding of the green coating to the substrate with less exposure of the substrate to high temperatures for long periods of time.
[0029] Another binding method is use of high temperature—high pressure (HT-HP), a process that is currently used for a variety of purposes including fabrication of polycrystalline cubic boron nitride (PCBN) solid compacts. In this invention, HT-HP is used as a post-deposition binding step to bind the deposited particles to each other and to the substrate.
[0030] In some embodiments, an additional treatment step (not shown in the figures) is applied after the post-deposition treatment step 300 , to add an additional phase to the coating. One example of this is the use of electrostatic spray coating or ultrasonic spray deposition as a final step, after deposition and sintering of a base coating, for the purpose of applying active biological agents to the base coating. As a more specific example, a dental implant or other biomedical device, possibly with a porous surface layer, can be coated using ESC or USD followed by microwave sintering of the base coating. Then in an additional post-sintering deposition step, an active agent can be applied, such as a biocidal or anti-bacterial agent, other active agents such as bone-morphogenic proteins, or particles carrying drugs for drug delivery at the surface of the device after implantation. These are just examples of how a post-processing step can be used to apply additional components to a base coating for specific purposes.
[0031] Other additional treatment steps (not shown in the figures) that can be applied after post-deposition treatment 300 can be used to enhance the binding of the coating and to reduce or eliminate defects and non-uniformities in the coating. For example, suitable treatments for hard coatings such as those used for cutting tools include high temperature—high pressure (HT-HP) and infrared sintering (pulsed infrared radiation). Other methods using transient energy sources also may be used to enhance the characteristics of the final coating on the substrate.
[0032] As shown in FIG. 2 , some embodiments of the invention include an optional pre-deposition treatment step 100 . Untreated coating materials 50 are treated prior to being passed as treated coating materials 150 to the deposition system 200 . For example, particles of coating material may be pre-treated for the purpose of functionalization (providing specific functionality desired for a specific application), or over-coating of particles for any of a number of purposes (e.g., protection of particles from high temperatures involved in the coating process).
Methods and Apparatus for Coating Deposition
[0033] FIG. 3 illustrates a method of deposition 200 that uses ultrasonic atomization and spray of a liquid dispersion to deposit materials on a substrate. Coating materials 150 , which may optionally have been pre-treated as discussed above, are introduced to a pressure delivery system 220 . A dispersant 215 also is introduced to the pressure delivery system, in which the coating materials are dispersed in the liquid dispersant. The pressure delivery system 220 maintains the materials in dispersion and pressurizes the dispersion, feeding it to an ultrasonic atomizer 235 .
[0034] The liquid used to create the dispersion can be chosen from among a number of suitable candidates, including methanol, ethanol, and the like. For ultrasonic spray of cubic boron nitride (cBN), we have used ethanol (C 2 H 5 OH) as the liquid. Ethanol has hydrophilic molecules or polar molecules, which helps to attach cBN particles with hygroscopic characteristics and to keep the particles suspended in the liquid. Other dispersants that are of polar characteristics can also be applied, or applied in combination with surfactants for further uniform dispersion.
[0035] An ultrasonic signal generator 240 is connected to a piezoelectric element within the atomizer 235 . The piezoelectric element converts the ultrasonic signal into mechanical action that atomizes the liquid dispersion into droplets, which are fed to a nozzle 245 . By adjusting the frequency of the ultrasonic signal, the size of the resulting droplets can be adjusted. Higher frequencies produce smaller droplets. For example, in one embodiment a frequency of 125 KHz is used, which produces droplets that have a median size of about 20 microns.
[0036] The nozzle directs the droplets toward the substrate or part to be coated, 170 . The liquid in the droplets evaporates, either in transit toward the substrate or after deposition on the substrate or a combination of the two. The result is a dry powder deposition of coating material(s) on the substrate. As an option, a gas flow (using air, nitrogen, or other suitable gas) may be introduced around the exit of the nozzle to further direct the droplet spray toward the surface. This can improve the speed of deposition as well as increase the efficiency of material deposition (fraction of material that is deposited on the substrate). The gas may be heated to speed up evaporation of the liquid.
[0037] Ultrasonic spray deposition (USD) offers several advantages over electrostatic spray coating (ESC) that make USD more suitable for some applications. Compared to ESC, USD can be used to create thinner coatings. Also, because the coating material is dispersed in a liquid that tends to de-agglomerate the material, and the ultrasonic atomization process itself tends to break up agglomerates, the resulting deposition is more uniform with a smoother surface. We also have found that we are able to create higher density coatings with USD, i.e., the volumetric fraction of coating material in the coating preform can be made higher with USD than with ESC.
[0038] FIG. 4 illustrates yet another method of deposition 200 that combines ultrasonic spray deposition with electrostatic charging. Again, coating materials 150 (untreated or pre-treated) and a liquid dispersant 215 are introduced to a pressure delivery system 220 . The combination of the ultrasonic atomizer 235 , ultrasonic signal generator 240 , and nozzle 245 create a spray with droplets of controlled size that are directed toward the substrate 170 . As discussed previously, a gas flow also may be introduced to further direct the droplet spray and increase speed and efficiency of deposition.
[0039] In this embodiment, the droplets are given an electrostatic charge by positioning one or more conducting electrodes 265 near the exit of the ultrasonic spray nozzle 245 . By applying a high voltage to the electrode(s), using an adjustable high voltage generator 260 , and grounding the substrate 170 (the substrate must have a surface with a certain conductivity), the droplets exiting the ultrasonic nozzle are charged and follow the electric field lines to the substrate. A variety of shapes and configurations can be used for the electrode, including a circular or elliptical collar, as well as one or more point electrodes arranged near the nozzle exit.
[0040] By adjusting the positioning of the nozzle 245 , electrode 265 and substrate 170 and adjusting the voltage, electrode-substrate distance, ultrasonic frequency (influencing droplet size) and spray pressure from the pressure delivery system 220 , the balance between electrostatic influence and the ultrasonic spray of the droplets can be altered to provide the characteristics needed for a given coating application. Adjusting the voltage level and the distance between the spray nozzle and the substrate can modify the transit time for droplets between nozzle and substrate. As an option, the carrier gas can be heated, affecting the rate at which droplets evaporate during transit. These various adjustments can be used to optimize the process such that the desired balance is achieved between dry deposition (droplets have evaporated prior to reaching the substrate) and wet deposition (droplets are still liquid when they deposit on the surface), allowing all dry, all wet, or hybrid wet/dry deposition to be used depending on what is best for the application.
[0041] This approach combines the positive aspects of both ultrasonic spray deposition (USD) and electrostatic charging, which provides several advantages:
Addition of electrostatic forces to the USD process can help coat 3 D surfaces conformally, placing less reliance on line of sight between nozzle and substrate surface; Addition of electrostatic forces improves the deposition rate compared to USD alone; Electrostatic forces also increase transfer efficiency (fraction of material sprayed that is deposited on the substrate), which increases productivity of deposition and reduces potential environmental effects of undeposited material; Electrostatic forces improve coverage of sharp edges, because the electric field lines tend to converge at the edges causing greater buildup of droplets/particles there; and Compared to electrostatic spray coating (ESC) alone (see U.S. Pat. No. 6,544,599, incorporated herein by reference), combining USD and electrostatic charging provides several of the advantages noted above for ultrasonic spray, namely the ability to create thinner, more dense and more uniform coatings.
[0047] A key part of the pressure delivery system for ultrasonic spray deposition is an ultrasonic tank, which maintains a suspension of particles within a dispersant for delivery to the ultrasonic spray system. FIG. 5 illustrates the ultrasonic tank apparatus. A pressure vessel ( 3 ) stores the particle suspension ( 4 ). An opening with suitable pressure seal (not shown in the figure) is used for initially filling the vessel manually. The vessel also can be filled automatically by providing appropriate feed lines/inlets for liquid dispersant and powder particles, along with suitable metering and automatic controls.
[0048] The vessel is pressurized using compressed air, nitrogen or other suitable gas under pressure, which enters the vessel at the compressed air inlet ( 5 ). For some applications, maintaining control of the humidity level or dew point of the gas may be required. As an option, the gas can be pre-heated to speed up the removal of the dispersant in the course of deposition. A pressure relief valve ( 7 ) is provided as a safety measure to prevent the vessel or other parts of the pressurized assembly from being over-pressurized and potentially leaking or rupturing.
[0049] The particle suspension exits the pressure vessel through a fluid pickup tube ( 6 ). The distance between the bottom of the fluid pickup tube and the bottom of the pressure vessel can be adjusted to ensure that fluid is drawn from a location within the pressure vessel that has consistent particle density and good suspension. Liquid level indication (not shown in the figure) is provided external to the pressure vessel.
[0050] As an option, the ultrasonic tank can employ any of a variety of means for maintaining a uniform dispersion of the particles. For example, in one embodiment shown in the figure, a commercial ultrasonic water bath ( 1 ) is used to surround the pressure vessel with sonicated water ( 2 ), which imparts ultrasonic vibrations to the pressure vessel and the suspension within. Other examples include use of mechanical vibrators attached to a surrounding bath or to the pressure vessel, an ultrasonic vibrator stick or similar device immersed in the suspension inside the vessel, mechanical stirrers, and other vibration or sonication means.
[0051] FIG. 6 illustrates a deposition chamber that can be used for electrostatic spray coating (ESC), ultrasonic spray deposition (USD), or USD plus electrostatic charging. A spray nozzle assembly ( 1 ) is mounted such that it sprays coating material (dry powder or liquid suspension containing particles) into the coating chamber ( 2 ). The spray nozzle assembly may employ electrostatic, ultrasonic, or ultrasonic plus electrostatic deposition means. The substrate(s) or part(s) to be coated are placed on a stage ( 4 ) that is suspended in the chamber using a stage suspension assembly ( 3 ). The orientation of the stage may be fixed or, as an option, a rotating stage may be used as described further herein. The distance between the stage and the spray nozzle can be adjusted.
[0052] The chamber is sealed so as to prevent egress of the coating material or ingress of contaminants. Material that is not deposited on the substrate(s) is collected in a powder recycling collector ( 5 ) so that material may be recycled. In the preferred embodiment, the unused material exits the sealed chamber via a liquid bath or by other filtering mean so that the material is captured for re-use and is prevented from being released to the environment.
[0053] In a preferred embodiment, the adjustments provided on the stage suspension assembly ( 3 ) are located external to the chamber by extending the assembly through the top of the chamber through openings that are sealed using O-ring type seals or other sealing means. With this design, adjustments in stage-to-nozzle distance can be made without opening the chamber.
[0054] FIG. 7 illustrates the rotating stage that is used as an option to improve uniformity of deposition across the surface of the substrate. The rotating stage can be used with electrostatic spray, ultrasonic spray, ultrasonic spray with electrostatic charging, and other deposition methods. An electric motor ( 1 ) drives the apparatus through a reduction gear ( 2 ), causing the center shaft ( 6 ) to rotate. A sun plate ( 7 ) is attached to the center shaft ( 6 ) and rotates with the shaft. A number of planetary gears ( 5 ) are mounted to the sun plate ( 7 ) using planetary shafts ( 8 ). The planetary gears mesh with an internal ring gear ( 4 ) that is mounted to the fixed mounting base ( 3 ). In one embodiment shown in the figure, six planetary gears are used.
[0055] As the sun plate rotates, the planetary gears move around the central axis of the assembly and, due to their interaction with the internal ring gear, the planetary gears also rotate on their own axes. Substrates are mounted on the individual planetary gear stages. The dual rotation action enhances the uniformity of the deposition on the substrate by ensuring that all points on the surface of the substrate are exposed equally to the material spray.
[0056] The planetary and ring gears can mesh using conventional gear teeth, or the planetary gears can be made as rollers that are pressed outward (e.g., by springs) such that the outer edge of each roller contacts the surface of the internal ring gear and friction causes the planetary gears to rotate.
[0057] For any type of electrostatic deposition, the planetary gears must be grounded in order to ground the substrate that is mounted on them. This requires that a means be provided to electrically connect the planetary gears to a grounded member. In one embodiment in which the planetary gears are rollers, the springs that press against the planetary gear shafts and hold the planetary gears against the internal ring gear also act as brushes to make an electrical connection between the planetary gears and the rest of the grounded rotating stage assembly.
[0058] The speed of the electric motor can be adjusted to ensure that the substrate to be coated is exposed to all parts of the deposition spray pattern equally in order to achieve the desired uniformity of coating. The speed can be adjusted by changing the power input (voltage) to the DC motor. In the specific embodiment shown in the figure, the ratio of the rotational speed of the planetary gears to that of the overall sun plate is fixed by the gear ratio. However, in alternative embodiments one or more additional motors or other means can be provided such that the two speeds can be adjusted independently.
[0059] The rotating stage also can be translated by mounting it on an appropriate platform that is moved laterally in either the x or the y direction, and the stage also can be translated in the z-axis direction (vertical direction in the figure), moving the rotating stage closer to or further away from the spray source.
[0060] FIG. 8 illustrates an integrated ultrasonic spray deposition system. Compressed air, nitrogen or other suitable gas is provided to the pressure delivery system through pressure control valves. One of these valves controls the pressure of gas that is sent to the ultrasonic tank. A liquid suspension of particles exits the pressurized ultrasonic tank and is sent to the ultrasonic spray nozzle assembly. As an option, a second valve is used to control the pressure of gas that is fed to the ultrasonic spray nozzle assembly to further direct the ultrasonic spray to the substrate. The ultrasonic spray nozzle assembly is mounted to the deposition chamber, which is described separately herein.
[0061] The same arrangement is used for ultrasonic spray deposition with electrostatic charging. In that case, an electrode and adjustable voltage source are provided and the substrate is grounded to provide electric field-assisted ultrasonic deposition. A commercial high-voltage generator available for ESC systems can be used; however, we have found that some modification is required for this application, namely modifying the voltage generator so that it can be applied to dispersants that have widely different dielectric constants.
[0062] Other optional features that can be included in the system described here are:
Pre-heating of the carrier gas or liquid, when desired for specific applications; Automation of the material feeds, gas and liquid dispersion flows, temperatures, and rotation/translation of the substrate, and automatic measurements of feed and deposition rates, temperatures and other key variables; Additional translation (in the x, y and/or z directions) of the substrate or ultrasonic nozzle (with or without electrostatic charging) or both, to allow deposition on large surfaces; and Use of multiple nozzles to allow coating large surfaces or complex geometries.
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Ultrasonic spray deposition (USD) used to deposit a base layer on the substrate, followed by chemical vapor infiltration (CVI) to introduce a binder phase that creates a composite coating with good adherence of the binder to the initial phase particles and adherence of the composite coating to the substrate, is disclosed. We have used this process to create coatings consisting of cubic boron nitride (cBN), deposited using USD, and titanium nitride (TiN) applied using CVI in various embodiments. This process can be used with many materials not usable with other processes, including nitrides, carbides, carbonitrides, borides, oxides, sulphides and silicides. In addition, other binding or post-deposition treatment processes can be applied as alternatives to CVI, depending on the substrate, the coating materials, and the application requirements of the coating. Coatings can be applied to a variety of substrates including those with complex geometries. The application also describes apparatus or equipment designs used to perform ultrasonic spray deposition.
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BACKGROUND OF INVENTION
This invention is directed to a method of polymerization and/or copolymerization of diolefins selected from the group of monomers consisting of trans-1,3-pentadiene and isoprene. It is also directed to catalyst systems used in these polymerizations. The products of these polymerizations have properties ranging from rubbers to plastics and thereby find utility in the preparation of vulcanized rubber products and plastics. The polymers which have glass transition temperatures (Tg's) which are relatively low may be utilized in tire carcass stocks while those with high Tg's may be used in tread stocks.
More specifically, this invention is directed to the use of a tertiary catalyst system comprising (A) an organometallic compound selected from the group consisting of trialkylaluminums, dialkylaluminum hydrides, dialkylmagnesiums, and dialkylzincs, (B) a soluble chromium compound selected from the group consisting of chromium salts of organic acids containing from 2 to 20 carbon atoms, organic complex compounds of chromium containing tridentate organic ligands, and π-bonded organochromium compounds, and (C) a member selected from tris(2-chloroethyl)phosphite, dialkyl hydrogen phosphites and diaryl hydrogen phosphites, to polymerize and copolymerize diolefins selected from the group of trans-1,3-pentadiene and isoprene.
Belgian Patent Nos. 530,617 and 535,082 and U.S. Pat. No. 2,825,721 were among the first to describe a partially reduced or partially oxidized chromium oxide supported on silica alumina cracking catalyst for the polymerization of ethylene.
U.S. Pat. No. 3,114,743 reported that butadiene was polymerized to a trans-1,4-polybutadiene using either CrCl 3 and diethylaluminum hydride or chromium acetylacetonate and triethylaluminum; the same catalyst polymerized isoprene but the polymer was not described. However, Belgian Patent No. 543,292 indicates that when diisobutylaluminum hydride-CrCl 3 were used to polymerize isoprene, a 1,4-polyisoprene was obtained.
Italian Patent No. 538,453 and British Patent No. 835,752 indicate that a binary catalyst system of chromium acetylacetonate and triethylaluminum polymerizes butadiene to a prevailingly 1,2-enchained linear polybutadiene and isoprene to prevailingly 3,4-polyisoprene.
Polyisoprenes prepared with a binary catalyst system such as chromium acetylacetonate plus triethylaluminum or tris(π-allyl)chromium plus a Lewis acid were generally low molecular weight liquids which had intrinsic viscosities of about 0.2 dl/g. This is reported in J. Polym. Sci., Chem. Ed 11, 2489 (1973).
In Proc. Acad. Sci. USSR 169, 790 (1966) it is reported that the presence of oxygen with tris(crotyl)chromium during the polymerization of butadiene caused almost complete inversion of the polymer microstructure from normally about 83 percent 1,2- to about 95 percent trans-1,4-polybutadiene. It has been reported in Bull. Acad. Sci. USSR, Div. Chem. Sci., 2059 (1967) that trichloroacetic acid with tris(crotyl)chromium polymerized butadiene to 93 percent cis-1,4-polybutadiene.
Polymers having high 1,4-trans-enchainments of isoprene and butadiene have been prepared using a chromia supported on silica-alumina, as reported in Dokl. Akad. Nauk. USSR 124, 595 (1959) and Polym. Sci. USSR 9, 1802 (1968).
Chem. Abs. 80, 109590 v (1974) reports the preparation of 1,2-polybutadiene by polymerizing butadiene in the presence of hydrogen using chromium acetylacetonate, dibutylphosphonate and triisobutylaluminum.
Chem. Abs. 80, 4644 n. (1974) reports that a polymer analyzing 95 percent 1,2-polybutadiene was prepared using a chromium compound, an organoaluminum compound and phosphoric acid ester catalyst system.
It has been reported in Kobunshi Ronbunshu 31, 754 (1974) that a binary catalyst system comprised of chromocene (dibenzene chromium) and an organic halide polymerized butadiene to a polymer having a microstructure very similar to that produced by radical initiators, that is, about 67% trans-1,4; 15% cis-1,4- and 18% 1,2-polybutadiene.
In U.S. Pat. Nos. 3,429,940 and 3,804,913 there is reported that a ternary catalyst system comprising chromium acetylacetonate, triethylaluminum and an aliphatic halide, such as t-butyl chloride, oligomerized conjugated diolefins such as butadiene, isoprene and piperylene, to large ring cyclic trimers such as trimethyl cyclododecatriene.
There is reported in U.S. Pat. No. 3,754,048 that another ternary catalyst system using chromium acetylacetonate, triethylaluminum and a nitrogen containing compound, such as α-(2-pyridyl)benzylidine-p-toluidine produced oligomers of butadiene, isoprene or piperylene. It is reported therein that the polybutadienes having molecular weights between about 300 and about 1400 were prepared and recovered in about 90 percent yield; less than 10 percent of the polybutadiene had a molecular weight between 1400 and 5500.
Therefore, to summarize, there has been no catalyst system containing chromium which has been previously used to prepare solid elastomers of trans-1,3-pentadiene and isoprene.
SUMMARY OF THE INVENTION
The invention consists of the polymerization and copolymerization of at least one diolefin selected from the group consisting of trans-1,3-pentadiene and isoprene employing as a catalyst a mixture of (A) at least one organometallic compound selected from the group consisting of aluminum trialkyls, magnesium dialkyls and zinc dialkyls, (B) at least one soluble chromium compound selected from the group consisting of chromium salts of organic acids containing from 2 to 20 carbon atoms, organic complex compounds of chromium containing tridentate ligands and π-bonded organo chromium compounds and (C) at least one member selected from tris(2-chloroethyl)phosphite, dialkyl hydrogen phosphites and diaryl hydrogen phosphites.
DETAILED DESCRIPTION OF INVENTION
The soluble chromium compounds employed in the practice of this invention may be chromium salts of carboxylic acids containing from 2 to 20 carbon atoms. The organic complex compounds of chromium containing tridentate organic ligands are also suitable. Tridentate organic ligands have three positions to which a covalent or coordinate bond with the metal may be formed. Representative of such a chromium containing tridentate compound is chromium acetylacetonate. The π-bonded organochromium compounds may be represented by tris(allyl)chromium, tris(methylallyl)chromium, tris(crotyl)chromium, π-cyclopentadiene chromium tricarbonyl and π-phenyl chromium tricarbonyl.
The preferred soluble chromium compounds useful in this invention are the chromium salts of organic acids and may be represented by chromium octanoate, chromium benzoate, chromium neo-decanoate, chromium benzoate, chromium neo-decanoate, chromium naphthenate, chromium oxalate and chromium stearate. Of all the soluble chromium compounds, the most preferred are chromium naphthenate, chromium neo-decanoate, and chromium octanoate.
The organometallic compounds employed in this invention are aluminum trialkyls or dialkylaluminum hydrides, representative examples of which are aluminum trimethyl, aluminum triethyl, aluminum tri-n-propyl, aluminum tri-n-butyl, aluminum triisobutyl, aluminum tripentyl, aluminum trihexyl, aluminum trioctyl, diethyl-aluminum hydride and diisobutylaluminum hydride and the like.
The dialkyl magnesium compounds useful in this invention may be represented by di-n-hexylmagnesium and n-butylethylmagnesium and the like.
The dialkyl zinc compounds may be represented by diethylzinc and dibutylzinc and the like.
The dialkyl hydrogen phosphites may be represented by the tautomeric structures: ##STR1## where R and R' indicate alkyl groups which may or may not be identical. The dialkyl phosphites exist substantially in the keto form (shown on the left) and are associated in dimeric or trimeric groupings by hydrogen bonding. The nomenclature dialkyl hydrogen phosphite, if applied strictly, describes only the keto tautomer, but it commonly is applied to both tautomeric forms and that it is the intent herein. The phosphites of this invention may be described further as having at least one phosphinic hydrogen atom.
The dialkyl hydrogen phosphites useful in the preparation of the catalyst of this invention are those containing from 1 to 20 carbon atoms in the alkyl groups. They may be represented by dimethyl hydrogen phosphite, diethyl hydrogen phosphite, diisopropyl hydrogen phosphite, dibutyl hydrogen phosphite, bis(2-ethylhexyl)hydrogen phosphite or dioctyl hydrogen phosphite, didodecyl hydrogen phosphite, dioctadecyl hydrogen phosphite, ethyl butyl hydrogen phosphite, methyl hexyl hydrogen phosphite and the like.
Diaryl hydrogen phosphites containing from 6 to 12 carbon atoms in the aryl groups may also be employed in the practice of this invention. They may be represented by dibenzyl hydrogen phosphite and diphenyl hydrogen phosphite. Cycloalkyl hydrogen phosphites, such as dicyclohexyl hydrogen phosphite, also may be used; and a monoalkyl-, monoaryl hydrogen phosphite, such as ethyl phenyl hydrogen phosphite and butyl benzyl hydrogen phosphite may also be utilized.
Tris(2-chloroethyl)phosphite is also useful in the invention.
The dialkyl hydrogen phosphites containing from 1 to 8 carbon atoms per alkyl group are the preferred phosphite containing compounds.
The catalyst system of the present invention has polymerization activity over a wide range of total catalyst concentration and catalyst component ratios. Catalyst components apparently interreact to form the active catalyst species. As a result, the optimum concentration for any one catalyst component is dependent upon the concentrations of the other catalyst components. While polymerizations will occur over a wide range of catalyst concentrations and ratios, the polymers having the most desirable properties are obtained within a narrower mole ratios range.
The molar ratio of the organometallic compound to the chromium compound (Me/Cr) can be varied from about 20/1 to about 2/1. However, a more preferred range of Me/Cr is from about 8/1 to about 4/1.
The molar ratio of the tris(2-chloroethyl)phosphite, dialkyl or diaryl hydrogen phosphite to chromium compound (P/Cr) may be varied from about 0.2/1 to about 10/1, with a more preferred range of P/Cr being from about 0.5/1 to about 3/1.
Catalyst components may be charged to the polymerization system as separate catalyst components in either a step-wise or simultaneous manner, usually called the in situ preparation. The catalyst components may also be preformed by premixing the three components outside of the polymerization system. The resulting premixed catalyst components then may be added to the polymerization systems.
The amount of total catalyst employed depends on such factors as purity of the components, polymerization rate desired, and the temperature. Therefore, specific total concentrations of catalyst cannot be set forth except to say that catalytic amounts should be employed. Successful polymerizations have been made using molar ratios of monomer to the chromium component in the ternary catalyst system ranging between about 300/1 to about 4,000/1. The preferred monomer to chromium concentration generally is between 600/1 and 2,000/1. Certain specific total catalyst concentration and catalyst component ratios which produce polymers having desired properties are illustrated in the examples elsewhere in the specification.
In general, the polymerizations of this invention are carried out in inert solvent systems and are, thus, considered to be solution polymerizations. By the term "inert solvent" is meant the solvent or diluent employed does not enter into the polymer structure nor does it have an adverse effect on the catalyst activity. Examples of such solvents are usually aliphatic, aromatic or cycloaliphatic hydrocarbons. The preferred solvents are hexane, pentane, benzene, toluene and cyclohexane. The solvent/monomer volume ratio may be varied over a wide range. Up to 20 or more/1 volume ratio of solvent to monomer may be employed. It is usually preferred to employ a solvent/monomer volume ratio of about 3/1 to about 6/1. It is possible to employ a suspension polymerization system in the practice of this invention. This may be done by choosing a solvent or diluent in which the polymer formed is insoluble.
It is usually desirable for best results to conduct polymerizations of this invention by employing air-free and moisture-free techniques.
Temperatures employed in the practice of this invention are not critical and may vary widely from a low temperature, for example, such as -10° C. or below to a high temperature of 100° C. or above. However, it is usually desirable to employ a more convenient temperature between about 20° C. and about 90° C.
The practice of the invention is further illustrated by reference to the following examples which are intended to be representative rather than restrictive of the scope of the invention. Unless otherwise noted, all parts and percentages are by weight. The dilute solution viscosities (DSV) which are reported in deciliters per gram were determined in toluene at 30° C. The glass transition temperatures (Tg) were determined using Du Pont's model 900 Differential Thermal Analyzer (DTA). The microstructures of the polypiperylenes were determined by a combination of Nuclear Magnetic Resonance (NMR), using a Varian A-60 spectrometer, and Infrared (IR) techniques, as described by D. H. Beebe, et al, in J. Polym. Sci., Part A-1 (in press). The microstructures of other polymers were determined by either NMR or IR methods.
EXAMPLE I
A premix containing a solution of transpiperylene in hexane at a concentration of 10 grams of monomer per hundred milliliters of total solution was charged to a series of 4-oz bottles. The catalyst components were charged by the in situ addition technique in the following order: The organometallic compound was charged first, followed by the chromium compound, followed by a dialkyl phosphite compound. The specific catalyst compounds in millimoles per hundred grams of monomer (mhm) are identified in Table 1 below. The bottles were placed in a water bath and maintained at 50° C. and tumbled end-over-end to provide agitation. The polymerizations were terminated by the addition of one milliliter of methanol plus one part/100 g. monomer of dibutylpara-cresol, and the polymers were isolated by drying under vacuum. Additional polymerization conditions and results are set forth in Table 1. The X-ray diffraction spectra of the polymers prepared in Runs 1 and 4 showed diffuse scattering which indicated that they were amorphous. The polymers had excellent resistance to oxidation. In an accelerated aging test in which the raw polymers are heated in a pure oxygen atmosphere at 90° C., Polymer No. 6 absorbed one weight percent of oxygen in 756 hours (anytime beyond 400 hours at 90° C. is considered very good).
Table 1__________________________________________________________________________ Pzn Polymer PolypentadieneRun catalyst, mhm Time, Yield DSV, Microstructure, %# TEAL Cr Naph (RO).sub.2 HPO Hours Wt % dl/g cis-1,4- tr-1,2- 3,4- Tg, ° C.__________________________________________________________________________1 10 2 1 Me.sup.a 18 74 2.5 71 24 5 -472 10 2 2 Me.sup.a 5 85 2.6 NA.sup.b NA.sup.b NA.sup.b -473 10 2 2 Bu.sup.a 1 99 3.4 NA.sup.b NA.sup.b NA.sup.b NA.sup.b4 5 1 1 Bu.sup.a 2 77 4.9 75 21 4 -485 10 2 2 Oct.sup.a 2 100 3.5 NA.sup.b NA.sup.b NA.sup.b NA.sup.b6 5 1 1 Oct.sup.a 4 84 4.6 74 20 6 -47 (Cl EtO).sub.3 P7 10 2 2 21 33 1.0 NA.sup.b NA.sup.b NA.sup.b -48__________________________________________________________________________ .sup.a Me = methyl; Bu = butyl; Oct = octyl .sup.b NA = not analyzed .sup.c mhm = millimoles per 100 g of monomer TEAL = triethylaluminum Cr Naph = chromium naphthenate (ClEtO).sub.3 P = tris(2-chloroethyl)phosphite
EXAMPLE II
The procedure in this example was similar to that in Example I except that chromium salts of different carboxylic acids and chromium acetylacetonate were utilized as the chromium catalyst component. Results are shown in Table 2.
Table 2__________________________________________________________________________ Pzn. PolypiperyleneRun catalyst, mhm Time, Yield, Microstructure, %# TEAL Cr.sup.1 (BuO).sub.2 HPO Hours Wt. % dl/g. cis-1,4 tr-1,2- 3,4- Tg,° C.__________________________________________________________________________1 12 2 Naph 2 0.5 100 3.6 75 21 4 -452 12 2 Dec 2 0l.5 98 4.4 74 21 4 ND3 15 2 Oct 2 0.5 100 3.8 75 21 4 -444 10 2 AcAc 2 2.0 85 3.0 ND ND ND ND5 5 1 AcAc 1 18.0 80 3.6 72 22 6 -44__________________________________________________________________________ .sup.1 Naph = Naphthenate Dec = neo-Decanoate Oct = Octanoate AcAc = Acetylacetonate ND = not determined.
EXAMPLE III
The procedure in this example was similar to that utilized in Example I except that different organoaluminum compounds were used, and in one instance, no phosphite compound was added in order to illustrate its importance to produce solid, moderately high cis-1,4-polypiperylene elastomers. Results are presented in Table III.
Table 3__________________________________________________________________________ Pzn.Run Catalyst, mhm Time, Yield, DSV,Microstructure, %# R.sub.1 R.sub.2 Al.sup.1 CrNaph (BuO).sub.2 HOP Hours Wt % dl/g cis-1,4 tr-1,2 3,4- Tg, ° C.__________________________________________________________________________1 10 TIBAL 2 2 2 69 3.8 72 23 5 -452 10 DIBAH 2 2 18 22 3.5 76 20 4 -483 10 TEAL 2 2 1 85 3.6 ND ND ND ND4 10 TEAL 2 0 18 90 0.1 15 47 10.sup.a NA__________________________________________________________________________ .sup.1 TIBAL = triisobutylaluminum DIBA-H = diisobutylaluminum hydride .sup.2 ND = not determined .sup.a Polymer No. 4 also contained 5 percent cis-1,2- and 23 percent trans-1,4-polypiperylene.
EXAMPLE IV
The procedure followed in this example was the same as that used in Example I except that different amounts of triethylaluminum (TEAL) were added in each experiment. Results are shown in Table 4.
Table 4______________________________________ Pzn.Run Catalyst, mhm Time, Yield, DSV# TEAL CrNaph (RO).sub.2 HPO.sup.1 Hours Wt. % dl/g______________________________________1 20 2 5 Me 5.0 99 2.52 15 2 2 Bu 0.5 100 3.43 12 2 2 Bu 0.5 100 3.64 10 2 2 Bu 0.5 97 4.15 8 2 2 Bu 21.0 41 4.2______________________________________ Me = methyl Bu = butyl
EXAMPLE V
The procedure used in this example was similar to that in Example I except that either two or all three of the catalyst components were premixed instead of adding them "in situ" to the piperylene in hexane solution. The premixed catalysts stood for 0.5 hour after mixing before injection into the premix. Results are illustrated in Table 5.
Table 5__________________________________________________________________________Catalyst, Pzn. PolymerMethod of Catalyst, mhm Time, Yield, DSV, Tg,Addition TEAL CrNaph (BuO).sub.2 HPO Hours Wt. % dl/g ° C.__________________________________________________________________________1. In situ 15 2 2 1 100 3.4 -44Premixed2. 2-components = Al/Cr 15 + 3 3 2 55 3.8 -473. 3-components = Al/Cr/P 15 + 3 + 3 18 46 3.3 ND__________________________________________________________________________
EXAMPLE VI
A distillate analyzed as set forth--68.5 percent trans-piperylene; 15.4 percent cyclopentene, 7.6 percent 2-methyl-2-butene, 4.0 percent cis-piperylene and about 5.5 percent of other olefinic hydrocarbons including 140 parts per million (ppm) of 1,3-cyclopentadiene and 240 ppm of 3-penten-1-yne. A solution of 4,270 grams of this distillate in 11,730 g of industrial grade hexane was passed through a silica gel column, and charged into a ten-gallon stirred reactor. Nitrogen was bubbled through the solution for two minutes and vented to remove any dissolved air. The temperature of the premix was raised to 50° C.
The catalyst components were added "in situ" as follows: (a) injected 106 milliliters of 1.8 molar triethylaluminum solution, (b) syringed in 40 mls of 0.75 M chromium naphthenate solution (=4 weight percent Cr), and (c) injected 32 ml of 1.2 M dibutyl hydrogen phosphite. There was a strong exotherm which raised the temperature in the reactor from 53° to 71° C. within about seven minutes. The temperature was restored to 50° C. after about 20 minutes with brine cooling in the jacket surrounding the reactor.
A sample of polymer cement was withdrawn from the reactor after one hour, and it had a solids content of 9.8 wt %, indicating about 54 percent conversion. After three hours, the solids content was 10.8 percent. The polymerization was terminated by adding 100 ml of a 34 percent aqueous solution of a 90 percent solution of tetrasodium salt of ethylenediaminetetraacetic acid and 23 grams of dibutyl-para-cresol dissolved in 400 mls benzene and 100 mls of methanol. The polymer cement was dried in trays at 40° C. under vacuum, and 1786 grams of dry polymer were recovered.
The microstructure of the polymer was 75 percent cis-1,4-, 21 percent trans-1,2- and 4 percent 3,4-polypiperylene. Its Mooney viscosity (ML-4 at 212° F.) was 63 and its DSV was 2.8 dl/g. The Tg was -44° C.
Thirty parts of the polymer were blended with seventy parts of natural rubber and it was evaluated in a radial tire carcass formulation. Some of its physical properties are as follows:
______________________________________Tensile strength 15.4 MPa300% Modulus 9.5 MPaElongation 465 percentHot Rebound 83 percent______________________________________
EXAMPLE VII
Seventy-five milliliters of a purified premix containing 20 volume percent of isoprene in hexane was charged to each of a series of 4-oz bottles. The isoprene contained 197 ppm of 1-penten-4-yne and 32 ppm of 1-pentyne as impurities according to gas-liquid chromatographic analysis. The catalyst components were charged by the in situ addition technique in the following order: The organometallic compound was charged first, followed by the chromium compound, followed by the dialkyl phosphite compound. The specific catalyst compounds in millimoles per hundred grams (mhm) of monomer are identified in Table VI:
Table 6__________________________________________________________________________ Pzn. Polymer PolyisopreneRun Catalyst, mhm Time Yield, DSV, Microstructure Tg,# TIBAL CrNaph (RO).sub.2 HPO Hours Wt % dl/g 1,4- 1,2- 3,4- ° C.__________________________________________________________________________1 10 2 2 Me 2 77 2.2 51 6 43 -322 10 2 2 Bu 2.7 92 3.6 NA NA3 10 2 2 Oct 18 99 4.0 56 5 38 -254 10.sup.a 2 2 Bu 2 84 2.6 56 5 39 -265 5 1 1 Bu 18 78 4.5 47 9 44 -25__________________________________________________________________________ R = Alkyl groups; Me = methyl; Bu = butyl; Oct = octyl TIBAL = triisobutylaluminum TEAL = triethylaluminum CrNaph = chromium naphthenate NA = not analyzed. .sup.a = TEAL used instead of TIBAL
EXAMPLE VIII
A purified solution of trans-piperylene in n-pentane containing 10 g of piperylene per 100 ml of solution was prepared. A second purified solution in pentane containing 10 g of isoprene per 100 ml of solution also was prepared. Aliquots of these solutions were measured into a series of 4-ounce bottles to prepare premixes containing a total of 10 grams of the two monomers in various ratios ranging between 90:10 and 25:75 trans-piperylene:isoprene. The monomers then were copolymerized using the experimental procedure outlined in Example I. The catalyst charged to each bottle in this series was TEAL:Cr Octoate:(BuO) 2 HPO=10:2:2 millimoles/100 grams of total monomer. The results are summarized in Table 7.
Table 7______________________________________ Pzn. PolymerRun Time Yield, DSV, Tg.sup.2No. t-PD.sup.1 IP Hours wt. % dl/g ° C.______________________________________1 100 0 1.5 100 3.8 -442 90 10 3 90 2.3 -423 75 25 3 73 1.6 -404 50 50 20 76 1.3 -375 25 75 20 83 1.2 -306 0 100 20 93 2.8 -23______________________________________ .sup.1 t-PD = trans-1,3-pentadiene IP = isoprene .sup.2 Tg's determined using a DuPont Model 990 Thermal analyzer.
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.
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There is disclosed a method for the polymerization and copolymerization of diolefins selected from the group of monomers consisting of trans-1,3-pentadiene and isoprene employing as a catalyst a mixture of (A) an organometallic compound selected from the group consisting of aluminum trialkyls, magnesium dialkyls and zinc dialkyls, (B) a soluble chromium compound selected from the group consisting of chromium salts of organic acids containing from 2 to 20 carbon atoms, organic complex compounds of chromium containing tridentate ligands and π-bonded organochromium compounds, and (C) a member selected from dialkyl hydrogen phosphites, diaryl hydrogen phosphites and tris(2-chloroethyl)phosphite.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the National Stage of International Application No. PCT/GB2004/005217, filed on Dec. 17, 2004, which claims priority to GB Application No. 0329351.1, filed on Dec. 18, 2003, and GB Application No. 0423172.6, filed on Oct. 19, 2004, the contents of which is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to semiconductor packages, mounting assemblies therefor and methods of manufacture thereof, and more particularly but not solely to, micro mounting packages that have an integrated heatsink and electromagnetic shield.
BACKGROUND OF THE INVENTION
The objective of any electronics package is to protect sensitive integrated circuits from harsh environments without inhibiting electrical performance. The package is used to electrically and mechanically attach a chip to an intended device. One popular family of electronics package is the Micro Leadframe Packaging (MLP) also known as Quad-Flat-No-Lead (QFN) or Dual-Flat-No-Lead (DFN). MLP is based upon a patterned and etched metal mounting commonly with a central pad, onto which a single or multiple semiconductor chips or dies are mounted, connected with wirebonds to isolated package pins, then encapsulated in a plastic sealing material. The sealing material is applied around the metal of the mounting and the integrated circuit with wirebonds to form a hard, protective plastic body.
Further information relative to mounting technology may be found in Chapter 8 of the book Micro Electronics Packaging Handbook, (1989), edited by R. Tummala and E. Rymaszewski, incorporated by reference herein. This book is published by Van Nostrand Reinhold, 115 Fifth Avenue, New York, N.Y.
Generally, manufacture is completed using an array of multiple MLP mountings. After encapsulation a mounting is separated from any supporting peripheral mounting structures and neighbouring packages by a punch or a saw.
It may be stated generally that there is a desire in the electronics packaging industry to reduce size and cost whilst at the same time as integrating more functionality. One proven route to increase functionality is to include several integrated circuits in the same MLP. Modern assembly techniques allow dies to be stacked or flip mounted (i.e. mounted in an inverted orientation) known as “flip-chip” mounting, ensuring a minimal final package size.
There are additional problems to be solved in the electronics packaging industry. One such problem is that many types of integrated circuit produce high levels of unwanted thermal energy, even when in normal operation. These circuits still require integration. Thermal design is also important and a method of dissipating heat to maintain electrical and mechanical stability has been sought.
Another such problem is that many electronics products need to operate in an electrically noisy environment. A method of protecting a sensitive integrated circuit within the package from unwanted electrical interference has also been sought.
A further such problem is that many electronics products require direct electrical connection to the system ground potential to obtain optimum performance. If this connection is electrically impaired (e.g. by resistive or inductive impairment) many integrated circuits particularly operating at intermediate and high frequencies or with high electrical currents may be adversely affected. A method of providing a low resistance, low inductance path to system ground has been sought.
SUMMARY OF THE INVENTION
The present invention relates to a semiconductor package, a mounting assembly therefor and a method of manufacture, and more particularly but not limited to, a micro mounting package that has an integrated heatsink and electromagnetic shield.
According to a first aspect of the invention there is provided a mounting for a semiconductor assembly including a first portion for mounting at least one semiconductor device, a second portion and a connecting portion joining the first and second portions and arranged to allow folding of the second portion over the semiconductor device.
The connecting portion may provide thermal and electrical communication between the first and second portions of the mounting.
The first portion of the mounting may comprise a formation of leadframe package connectors.
The first portion of the mounting may further comprise a base support for at least one semiconductor device.
The second portion may comprise a cover having a semiconductor assembly-facing surface and an opposed heat-radiating surface.
The electrical connectors of the mounting are in a spaced relationship with the base support and are linked electrically with the semiconductor assembly.
The cover is arranged to be in a spaced parallel relationship with the base support.
The cover may further comprise at least one additional edge portion arranged to extend when the mounting is folded beyond at least one edge of the first portion of the mounting. Such an edge portion can be folded to form a sidewall.
The mounting is preferably formed from a single sheet of electrically and thermally conducting material, which is preferably a metal, more preferably copper.
The mounting may be part of an array of a plurality of mountings.
The mounting is preferably provided with folding means to enable it to be bent such that the cover can be arranged to be in a spaced parallel relationship to the first portion. The folding means is preferably a weakened line, such as a scored line or an etched line in the mounting having a thickness that is less than that of the rest of the mounting.
Preferably the mounting includes two weakened lines, one between the first portion and the connecting portion and one between the second portion and the connecting portion.
The cover of the mounting is arranged to be mechanically and electrically connected to the base support and the base support is normally connected to System Ground potential (GND) on the final product printed circuit board. The particularly advantageous feature of the present invention is the cover which provides three functions (a) a simple heatsink (b) a low resistance, low inductive path to electrical Ground (GND) and (c) to act as a local electromagnetic shield protecting sensitive functions within, or without, from unwanted electromagnetic interference.
The semiconductor chip may be electrically connected to a portion of the mounting by wirebonding. Alternatively, the chip may be mounted using flip-chip mounting, such as bump soldering.
The new mounting package can be used for single or multiple chip applications. Where multiple chips are integrated it is often beneficial to “flip” smaller (daughter) chips onto a larger (mother) die. The new package facilitates connection to a simple heatsink and electromagnetic shield and System Ground (GND). Through modern assembly techniques the present invention reduces cost and area usage on a printed circuit board whilst improving thermal and electrical performance.
The semiconductor assembly is preferably attached to the base support and/or the cover. Where the assembly comprises two or more semiconductor chips, it is preferably attached to the base support and the cover. This enables a daughter semiconductor chip to be connected more directly to system ground. The assembly is preferably electrically attached to the base support and/or cover, more preferably by conductive wire or conductive epoxy or solder material.
A semiconductor package incorporating the mounting preferably comprises a sealing material at least partially encapsulating the mounting and the semiconductor assembly. This is in order to protect and support the contents of the package. At least part of the printed circuit board facing surfaces of the package connectors and base support or the heat radiating surface of the cover may not be covered by the sealing material, being left exposed to aid the dissipation of heat.
The mounting preferably further comprises heat dissipation means to provide a low thermally resistive path between a mounted semiconductor assembly and the cover of the package.
The mounting may be provided with a third portion and second folding portion arranged to allow folding of the third portion over the semiconductor device. The third portion is in a spaced parallel relationship with the base support and second portion.
The mounting may further comprise means for mounting surface mount technology (SMT) components. Such components may comprise passive components, for example resistors, capacitors, or inductors.
Such means may comprise recesses in the mounting cover to mount SMT components.
The cover of the mounting may be patterned to function as a passive component. For example, the top cover may be formed as a serpentine inductor.
Other passive components can be integrated. The cover may be patterned as an interdigitated or parallel plate capacitor. The cover may also be patterned to integrate other components such as antenna, microstrip couplers and filters.
The mounting preferably further comprises an EMI enhanced package wherein the cover is fabricated with additional fold means to enable the cover to be bent to define walls in relationship with the semiconductor assembly.
The mounting may further comprise means adapted for mounting sensor semiconductor chips.
The cover of the mounting may be adapted to provide direct access to the semiconductor assembly. Such means may comprise an aperture in the package mounting cover. The mounting may be further adapted to mount optical components in relationship to an image sensor semiconductor chips.
The aperture may be further defined by having recesses about its perimeter. The recesses may face towards, or away from, a mounted semiconductor device. The aperture and the recesses can be used to locate further components for use in the semiconductor assembly.
The mounting may be further adapted to provide for mounting biometric semiconductor chips.
The mounting may be further adapted to provide for mounting pressure sensor semiconductor chips.
The mounting according to the invention preferably further comprises one or more recesses formed within the cover into which mould material can flow to secure the cover in the package.
The mounting according to the invention preferably further comprises means to permit coupling of selected frequencies of electromagnetic radiation through the leadframe. Such means may comprise apertures in the cover of the mounting of appropriate dimension to permit coupling at a selected frequency.
In another aspect of the invention there is provided a method of manufacturing a semiconductor assembly comprising the steps of:
preparing a mounting for a semiconductor device; mounting a semiconductor chip on the mounting; electrically connecting the semiconductor chip to the mounting; and folding a portion of the mounting over the semiconductor assembly.
The step of preparing the mounting may further comprise forming functional features in the mountings. The features may be formed by, for example, cutting, scribing, stamping or etching.
The step of preparing a mounting may further comprise forming fold lines into the mountings.
The folded portion may be folded through a total of 180°, for example by being folded through 90° along each of two fold lines. The folded portion can then be in a spaced parallel relationship with the portion the semiconductor chip is mounted on.
The method may further comprise folding a further portion of the mounting over the semiconductor assembly.
The method may further comprise folding additional portions of the mounting to form, for example, sidewalls in the mounting.
The functional features may further include heatsinks. Passive components can also be formed in portions of the mounting.
The method may further comprise the step of sealing said mounting. Any suitable sealant could be used for this purpose, for example, a dielectric sealant.
The method further comprises forming an aperture in a portion of the mounting. Recesses can be defined about the perimeter of the aperture. The recesses may face towards, or away from, a mounted semiconductor device.
The method may further include mounting and aligning components for use in the semiconductor assembly. Such further components include optical components, such as lenses or filters.
The components may be mounted on the mounting before it is folded such that folding the mounting brings the component into the desired final position in the assembly.
The method may further comprise electrically connecting the semiconductor chip to using wirebonding.
The semiconductor chip may be flip-chip mounted.
The method further comprises mounting further semiconductor chips on the same mounting. The further chips can be mounted using adjacent or stacked wirebond and/or flip-chip mounting. The mounted chips can be connected to a common mounting and/or each other.
The mounting may be one of an array of such mountings.
The mounting can be separated from the array by, for example, cutting, punching or sawing.
In another aspect of the invention there is provided a method of manufacturing a semiconductor mounting wherein individual mountings are patterned on a sheet of conducting material, wherein the individual mountings are defined with a first portion for mounting at least one semiconductor device, a second portion and a connecting portion joining the first and second portions and arranged to allow folding of the second option over the semiconductor device.
The mountings may be patterned by casting, etching or stamping.
The sheet may be a suitable metal, for example, copper.
The individual mountings may be part of an array of such mountings. The method further includes the step of separating individual mountings from the array.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated with reference to the following Figures of the drawings wherein:
FIG. 1 shows a side elevation, cross-sectional view of a known MLP-type semiconductor package;
FIG. 2 shows a side elevation, cross-sectional view of an MLP-type semiconductor package according to the invention with a formed upper pad;
FIG. 3 shows a top plan view of an MLP-type semiconductor package according to the invention;
FIG. 4 shows a bottom plan view of an MLP-type semiconductor package according to the invention;
FIG. 5 shows a plan view of a known MLP-type semiconductor mounting;
FIG. 6 shows a plan view of an MLP-type semiconductor mounting according to the invention, laid flat and showing formed upper pad prior to bend;
FIG. 7 shows a plan view of a manufacturing array of mountings according to the present invention;
FIG. 8 shows a plan view of a laid flat MLP-type semiconductor mounting according to the present invention wherein the mounting has no package connectors on the edge adjacent the cover to maximise the area of the connecting formation;
FIG. 9 shows a plan view of a laid flat MLP-type semiconductor mounting according to the present invention having a cover which is defined with apertures;
FIG. 10 shows a plan view of a laid flat MLP-type semiconductor mounting according to the present invention having four package connectors on the side adjacent the cover;
FIG. 11 shows a side elevation, cross-sectional view of a second embodiment of a semiconductor package according to the present invention;
FIG. 12 shows a side elevation, cross-sectional view of a third embodiment of a semiconductor package constructed in accordance with the principles of the present invention;
FIG. 13 shows a side elevation, cross-sectional view of the construction of a single bend point;
FIG. 14 shows how a pair of bend points may be used to construct the connecting formation used in the present invention;
FIG. 15 shows a side-elevation, cross-sectional view of the second embodiment of the present invention mounted on a printed circuit board.
FIG. 16 shows a side elevation, cross-sectional view of a known flip-chip onto leadframe MLP-type package;
FIG. 17 shows a top plan view of a mounting used to make the package of FIG. 16 ;
FIG. 18 shows a side elevation, cross-sectional view of a flip-chip onto leadframe MLP-type package according to the invention with a formed upper pad;
FIG. 19 shows a top plan view of a mounting used to make the package of FIG. 18 ;
FIG. 20 shows a side elevation, cross-sectional view of a flip-chip onto leadframe MLP-type package according to the invention with a formed upper pad and base pad;
FIG. 21 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with heatsink die enhanced feature;
FIG. 22 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with stacked die;
FIG. 23 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with integrated surface mounted (SMT) passive components;
FIG. 24 shows a top plan view of a mounting used to make the package of FIG. 23 ;
FIG. 25 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with enhanced EMI shielding;
FIG. 26 shows a top plan view of a mounting used to make the package of FIG. 25 ;
FIG. 27 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with an aperture feature;
FIG. 28 shows a top plan view of a mounting used to make the package of FIG. 27 ;
FIG. 29 shows a top plan view of a mounting according to the invention used to make an MLP-type package with a circular aperture feature;
FIG. 30 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with an aperture feature fitted with a lens, made using the mounting of FIG. 29 ;
FIG. 31 shows a top plan view of a mounting according to the invention used to make an MLP-type package with a double pad feature and aperture feature;
FIG. 32 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with a double pad feature and aperture feature fitted with a lens, made using the mounting of FIG. 31 ;
FIG. 33 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with a double pad feature and aperture feature fitted with a lens;
FIG. 34 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with exposed die feature;
FIG. 35 shows a side elevation, cross-sectional view of a further embodiment of an MLP-type package according to the invention with exposed die feature;
FIG. 36 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with exposed die feature and gel-filled cavity;
FIG. 37 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with an entirely encapsulated, non-exposed cover pad;
FIG. 38 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with a partially exposed top metal pad;
FIG. 39 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with a patterned underside of the top metal pad;
FIG. 40 shows a side elevation, cross-sectional view of an MLP-type package according to the invention showing a dielectric fill material dispensed over the die surface; and
FIG. 41 shows a mounting for making an MLP-type package according to the invention with electromagnetic coupling apertures;
FIG. 42 shows a section through an MLP-type package according to the invention;
FIG. 43 shows a section through a further MLP-type package according to the invention;
FIG. 44 shows a mounting for making an MLP package according to the invention with a cover pad including the definition of a serpentine inductor with a semiconductor chip shown mounted to the base with wirebonds connecting to the perimeter connectors and to the inductor;
FIG. 45 shows a mounting for making a package according to the invention with a top cover pad in addition to a defined serpentine inductor; and
FIGS. 46 to 48 show the results of modelling packages according to the invention.
Before discussing the embodiments of the present invention, the prior art MLP-type semiconductor package is discussed below in order to provide background information regarding the techniques of construction of MLP-type semiconductor packaging.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In reference to FIG. 1 , there is shown a side-elevation, cross-sectional view of a known MLP-type semiconductor package 40 . The semiconductor package contains a mounting 47 consisting of a base support (also referred to as a paddle or base mounting pad) 42 , a plurality of package connectors (also referred to as package pins) 44 , a single semiconductor chip 41 connected to the base 42 by bonding layer 48 and a plurality of wires (also referred to as wirebonds) 43 which link the chip 41 to the package connectors 44 . The complete assembly is enclosed in a nonconductive sealing material 45 . Sealing material 45 may be a thermoplastic or thermoset resin (including an epoxy, phenolic and/or silicone resin).
Numerous techniques for secure attachment of a semiconductor chip 41 to the base 42 are in practice, including conductive and/or nonconductive epoxy or solder 48 . The top surface of the semiconductor chip 41 , usually has, at its periphery, a plurality of connecting pads 46 . A plurality of package connectors 44 surround the mounted semiconductor chip 41 and base 42 . Wires 43 electrically connect to the semiconductor die connecting pads 46 and the package connectors 44 . The package base support 42 and connectors 44 are rectangular in cross-section but may be etched to improve fixing to sealing material 45 . The pluralities of package connectors 44 are commonly located at the periphery of the semiconductor package 40 . The base support 42 is generally located centrally to the package base. Package connectors 44 and base support 42 are used to connect to a printed circuit board (PCB), not shown.
An MLP-type semiconductor package aids dissipation of heat generated from the operation of the semiconductor chip 41 via the lower exposed surface of the base support 42 and the lower and lateral exposed surfaces of the package connectors 44 . Some heat is also dissipated from the upper surface, to air surrounding the semiconductor package 40 . However the sealing material 45 tends to prevent this by insulating the semiconductor chip 41 .
Semiconductor chips 41 are designed for many different applications and markets. Often there is an advantage in providing an electromagnetic shield over and in close proximity to the semiconductor chip 41 . Such a shield may protect the semiconductor chip from unwanted interference from external radio signals and propagated waves but also protect the external system from signals generated from semiconductor chip 41 under its own operation.
The prior art package has no externally exposed top metal pad to aid additional thermal dissipation or to give electromagnetic shielding protection to the semiconductor chip 41 or external system by presenting a shield or barrier to radio signals. The prior art package does not allow direct connection to the rear face of a stacked (flip-chip) mounted daughter die when mounted to the upper surface of the semiconductor die 41 on the base 42 .
FIGS. 2 to 4 and 6 to 14 illustrate aspects of the invention. In these Figures, like features are indicated by like identification numbers.
Referring to FIG. 2 , here shown is a side-elevation, cross-sectional view of semiconductor package 50 . This is the first embodiment of a semiconductor package according to the present invention. The semiconductor package contains a mounting 57 consisting of a base support 52 , a cover 60 , connecting formation 59 , a plurality of package connectors 54 , a single semiconductor chip 51 and a plurality of wires 53 . The complete assembly is enclosed in a nonconductive sealing material 55 . Sealing material 55 may be a thermoplastic or thermoset resin (including an epoxy, phenolic and/or silicone resin). FIG. 2 shows a semiconductor chip 51 mounted to the base support 52 . Numerous techniques of secure attachment are in practice, including conductive and nonconductive epoxies, or solder 58 . The top surface of the semiconductor chip 51 , usually has, at its periphery, a plurality of connecting pads 56 . A plurality of package connectors 54 surround the mounted semiconductor chip 51 and base support 52 . Wires 53 electrically connect to the semiconductor die connecting pads 56 and the package connectors 54 . The pluralities of package connectors 54 are located at the periphery of the semiconductor package 50 . The base support 52 is generally located centrally to the package base. Package connectors 54 and base support 52 are used to connect to a printed circuit board (not shown).
The connecting formation 59 connects the base support 52 and cover 60 . The connecting formation 59 provides a low resistance, low inductance thermally efficient path from the cover 60 to the base mounting pad 52 and to the external printed circuit board (not shown). The base support 52 and cover 60 , the connecting formation 59 and package connectors 54 are secured to a mounting foil via mounting supporting structures or tie-bars (not shown). Tie bars and other supporting structures are trimmed off at the package dicing stage of manufacture.
The mounting 57 may be etched to provide additional locking strength between the mounting 57 and the sealing material 55 . The connecting 30 formation 59 has a weakened fold line in the form of a lateral etch, cut or scribe used at each end of the connecting formation 59 to define bend points 70 for the formation of the cover 60 of the package. The top side of the base support 52 is attached to the semiconductor chip while the bottom side of the base mounting pad 52 is exposed to the outside of the semiconductor package 50 . The bottom side of the base support 52 and the upper side of the cover 60 are electroplated with a corrosion-minimizing material such as tin, gold, tin lead, tin bismuth, nickel palladium or other suitable alloy. The bottom side of the base support 52 will be mounted to the printed circuit board (not shown). The topside of the cover 60 is exposed to the outside of the semiconductor package 50 and is generally centrally located in the top surface of the package.
The mounting 57 is fabricated from a sheet of electrically and heat conducting material such as copper. Heat generated from the operation of the semiconductor chip 51 is dissipated throughout the semiconductor package and through the bottom of the base mounting pad 52 to the printed circuit board. The exposed cover 60 will aid heat dissipation. Heat will also be dissipated through the plurality of package connectors 54 . The plurality of package connectors 54 does not normally touch the base mounting pad 52 .
Still referring to FIG. 2 , semiconductor package 50 has a semiconductor chip 51 attached to the base support 52 via an adhesive or suitable solder material 58 . The plurality of package connectors 54 electrically connect to the semiconductor chip 51 through a plurality of wires 53 . Each wire 53 has a first end electrically connected to one of the bond pads 56 on the top side of the semiconductor chip 51 and a second end connected to the lower portion of one of the package connectors 54 . Wires can be made of any electrically conductive material; gold aluminium or silver are common choices.
Sealing material 55 preserves the spatial relationship between the cover 60 and the base support 52 , the connecting formation 59 , wires 53 , mounted semiconductor chip 51 , and semiconductor package connectors 54 . The sealing material 55 forms a rigid structure to maintain protection and form to the semiconductor package 50 and its component parts. After sealing only the areas of the base support 52 and cover 60 , lower and outer edges of the package pins 54 remain exposed allowing connection to a printed circuit board.
FIG. 3 shows a top plan view of semiconductor package 50 . The cover 60 is located generally to the middle of the semiconductor package 50 . At the four edges of the semiconductor package 50 sealing material 55 is shown defining the outer edge. The sealing material 55 ensures an interlocking structure with the cover 60 . Only the upper portion of the cover 60 is exposed.
FIG. 4 shows a bottom plan view of the semiconductor package 50 . As shown the base support 52 is located, generally, to the middle of the semiconductor package 50 , surrounded on four sides by a plurality of package connectors 54 . At the four edges of the semiconductor package 50 , sealing material 55 defines the outer edge. The sealing material 55 ensures an interlocking structure with the base support 52 and package connectors 54 . Only the lower exposed and plated portion of the package connectors 54 and base support 52 are visible.
FIG. 5 shows a top plan view of a known MLP-type package 47 for a semiconductor package 40 . As shown the base support 42 is located generally to the middle of the semiconductor package 40 , surrounded on four sides by a plurality of package connectors 44 .
FIG. 6 shows a plan view of a mounting 57 for a semiconductor package 50 according to the present invention shown in its basic state prior to bending. Support structures 74 for mounting definition are shown for two pins on the package near to where the connecting formation 59 is defined. Other tie-bars and support structures for mounting manufacture are not shown, however the plurality of package connectors 54 are shown interconnected as the case may be before trimming. Etched or scribed bend points 70 (dotted) are positioned to define the connecting formation 59 . A dashed line is shown intersecting each about the plurality of package connectors 54 . The dashed line indicates the package outer dimension after dicing.
FIG. 7 shows a plan view of an array 77 of multiple individual mountings 57 for semiconductor package 50 to show how an individual mounting 57 may be manufactured from a larger area of metal material. The array 77 can be initially manufactured by a variety of process, for example, casting, etching or stamping.
The array layout allows for the simple assembly of a semiconductor package. Using the array shown in FIG. 7 as an example, a semiconductor chip 51 can be mounted on individual MLP mountings 57 as shown. Semiconductor chips can be placed on each mounting using standard techniques, for example, processing the array to fix and solder the components on the mount. The processing can include solder bumping, epoxying and wire connecting. The packages can be further processed, for example using such techniques as solder reflow, injection of dielectric 55 onto the mount, semiconductor-mounting binder curing and so forth.
The individual mounts are then folded through 90° along each of the fold lines 70 so that the cover 60 extends over the chip 51 , parallel to the base 52 and connectors 54 . The sealing material 55 is then injected between the cover and the chip 51 . Mountings can be separated from any supporting peripheral mounting structures and neighbouring packages by, for example, a punch or a saw that cuts along the dashed lines of FIG. 6 . Since the fold lines 70 are within the dashed lines after folding, the connecting portion 59 remains in place after cleaving. Alternatively, the individual MLPs can be cut and processed individually.
FIG. 8 shows a plan view of a variation of the mounting 57 shown in FIG. 6 for a semiconductor package 50 . In the mounting shown in FIG. 8 , there are no pins on side adjacent the connecting formation 59 . Tie-bars and support structures for mounting manufacture are omitted, however the plurality of package connectors 54 for the other three sides are shown interconnected as the case may be before trimming. A semiconductor package using this type of amounting can be assembled using the same techniques described above.
FIG. 9 shows a plan view of a variation of the mounting 57 for semiconductor package 50 shown in FIG. 6 . The cover 60 forms a plurality of apertures. An example, arbitrary, pattern is shown though an alternative pattern could be used. The apertures can be made in the cover 60 as and when required during the assembly process described above by cutting, etching or punching the desired pattern in the cover. The apertures could be made, for example, while the mounting is in an array of the sort shown in FIG. 7 , or afterwards, when it has been separated.
FIG. 10 shows a plan view of a variation of the mounting 57 shown in FIG. 6 . In this example, there are four pins on the package side where the connecting formation 59 is defined.
FIG. 11 shows a side-elevation, cross-sectional view of a second embodiment of a semiconductor package 50 according to the invention. In this embodiment, multiple semiconductor chips are integrated. There is a single mother semiconductor chip 61 and two inverted chips 62 , 63 mounted on the mother semiconductor chip 61 . The larger mother semiconductor chip 61 may be mounted first to the base support 52 . The top surface of the semiconductor chip 61 , is specifically designed to have corresponding connection pads 64 upon which to mount a plurality of smaller daughter chips 62 , 63 .
Modern “flip-chip” assembly techniques are used to mount the daughter chips 62 , 63 upon the upper surface of the mother semiconductor chip 61 .
The daughter semiconductor chips 62 , 63 are pre-thinned and prefabricated, perhaps at wafer level, with materials to form a plurality of “bumps” to facilitate the flip-chip connection. Singular bumps 66 are positioned at each of the connection pads 65 of the daughter die 62 , 63 . Popular methods of bumping semiconductor chips are, solder deposition/reflow or gold stud. Alternative attachment materials include anisotropic conducting materials.
Under-fill material 67 may be added between the mother and daughter chips to improve reliability and thermal performance of the flip-chip bonds 66 . Some types of under-fill material 67 can be applied to the flip-chip stack either before or after the placement is made.
The direct connection of electrical, and mechanical path from the daughter chips 62 , 63 to the cover 60 will aid thermal and electrical performance. The exposed cover 60 will aid heat dissipation.
In this example the mother chip 61 is mounted on the base 52 using the techniques described above. Additional connection pads 64 can be fixed at the desired points on the mother chip 61 and solder bumped chips can be located on the mother chip and reflow soldered. The assembly can be cleaned if necessary to remove any debris from the reflow process. If desired, the space between the daughter chips 62 and the mother chip 61 can be filled using standard underfill techniques and materials.
Alternative flip-chip techniques can be employed, such as thermocompression bonding, thermosonic bonding and using conductive adhesives.
An alternative substrate material such as flex, pcb, ceramic or glass may also be used in place of the described mother semiconductor chip 61 .
FIG. 12 shows a side-elevation, cross-sectional view of a third embodiment of a semiconductor package 50 . In this embodiment, as in the second embodiment shown in FIG. 11 , multiple semiconductor chips are integrated. The plurality of wires 53 in the second embodiment are replaced with through-hole vias 68 in the mother semiconductor chip 61 .
The mother semiconductor chip 61 is designed with through-hole vias 68 with upper and lower capture pads 75 , which facilitate a vertical connection through to the base of the chip 61 . The through-hole via 68 and capture pads 75 may be designed to align and allow connection directly with the package connectors 54 and/or base support 52 . Multiple through-hole vias 68 may be arrayed to improve electrical connection or thermal relief. Conductive epoxy or solder material 58 is pre-deposited upon the plurality of package connectors 54 . This deposition of a conductive layer or solder 58 is made at the same time as the deposition of epoxy or solder material on the base support 52 . Upon placement of the mother semiconductor chip 61 a desired electrical connection between the underside of the mother semiconductor chip 61 and package connectors 54 and/or base support 52 is formed.
An alternative substrate material such as flex, pcb, ceramic or glass may also be used in place of the described mother semiconductor chip 61 .
FIG. 13( a ) shows a side-elevation, cross-sectional view of a defined bend line 70 in the mounting metal foil. Processes of etching and scribing are used to define a particular cross-section within the mounting metal foil which will provide a repeatable, reliable and robust mechanism for bending of the mounting to form the connecting formation 59 and cover 60 .
FIG. 13( b ) shows a side-elevation, cross-sectional view of the same single defined bend line 70 in the mounting metal foil after being formed to an angle of 90 degrees.
FIG. 14( a ) shows a side-elevation, cross-sectional view of two defined bend line 70 in the mounting metal foil. The bend points 70 are defined at a distance specific and relating to the desired height of connecting formation 59 and separation from base support 52 and cover 60 . Processes of etching and/or scribing are used to define a particular cross-section within the mounting metal foil which will provide a repeatable, reliable and robust mechanism for bending of the mounting to form the connecting formation 59 and cover 60 .
FIG. 14( b ) shows a side-elevation, cross-sectional view of same two defined bend line 70 in the mounting metal foil after each is bent through to an angle of 90 degrees.
FIGS. 13( b ) and 14 ( b ) show the bend line feature formed by the removal of material from the outer side of the bend. There are advantages to methods of bending with the etched or scribed line 70 on the inner side of the bend. One advantage of this is that it allows greater control over the bending action. This is because the two sides of the etched or scribed line come into contact at a predetermined bending angle and stop the bending at that angle. Angles other than 90 degrees can be used. For example three bends of 60 degrees each could be used.
FIG. 15 shows a side-elevation, cross-sectional view of the second embodiment of the present invention, a semiconductor package 50 mounted to a printed circuit board 73 . A thermally conductive material 71 is deposited upon the top surface (cover 60 ) of the package and used to dissipate heat. The thermally conductive material 71 is shown deposited so that it makes contact to a suitable casing or body 72 of the final product. Open arrows depict the general dissipation of heat energy away from the package.
Further embodiments of the invention use flip-chip bonding techniques. Before discussing these further embodiments in detail, the prior art flip-chip-onto-leadframe-pin MLP-type semiconductor package is discussed below.
FIG. 16 shows a cross-sectional view of a known flip-chip-onto-leadframe-pin MLP package. A top plan view of the same prior art mounting or leadframe for a flip-chip-onto-leadframe-pin QFN package is shown in FIG. 17 .
With reference to FIG. 16 , here the semiconductor die has been “bumped” using standard techniques to provide physical and electrically conductive connection to each of its signal pads. As previously mentioned above, popular methods of implementing the conductive bumps 66 are by gold stud, deposited and reflowed solder or deposited conductive column structures. The die has then been flipped over and mounted directly to the leadframe package pins using recognised methods. The package is moulded and diced using standard processes.
With reference to FIG. 17 , the mounting 7 is designed with elongated peripheral pins making the desired connection from package edge to underneath the semiconductor die.
In this type of “flip-chip-onto-leadframe-pin” MLP package, the base die mounting pad used in wirebonded QFN packages is often removed to allow the inward extension of the peripheral package signal pads under the die. This also improves access for mould material.
Although not shown, it is also possible to have a base pad present allowing multiple connections under the chip. Thermal performance is improved through such an array of bumps connecting to this pad.
FIGS. 18 to 22 illustrate further aspects of the invention applied particularly to flip-chip mounting in packages. Like numerals refer to like features.
With reference to FIG. 18 , here is shown a cross-sectional view of an embodiment of a flip-chip-onto leadframe-pin MLP package, according to the invention. A plan view of the mounting design for the embodiment of FIG. 18 is shown in FIG. 19 .
Referring to FIG. 18 , here, as with the prior art, a pre-bumped semiconductor die 41 has been flipped and mounted onto the base mounting pins 44 . Here the embodiment improves upon the prior art by providing an additional, exposed top pad heatsink and EMI shield. The top metal pad 60 is formed and attached to the back of the die 41 using standard materials such as solder paste or conductive adhesives. The side view of a half-etched support structure 72 is shown extending and anchoring the top pad and pins. This can be seen more clearly in FIG. 19 .
Referring to FIG. 19 , the mounting design for the embodiment is shown with the top die pad 60 lying flat. The top pad and bend structures 74 are mechanically supported by mounting material structures.
FIG. 20 shows a further embodiment of a flip-chip-onto-leadframe-pin package, where a base pad 52 is present thus enabling multiple die connections under the chip 51 . Thermal performance is improved through the flip-chip bumps connecting to this pad.
FIG. 21 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with a heatsink die. This embodiment is intended for use where extra thermal dissipation is required.
The embodiment shown in FIG. 21 has an additional “die” 80 of thermally conductive material mounted upon the surface of the semiconductor die 51 . A thermally conductive adhesive can be used to fix the thermally conductive material to the surface of the semiconductor chip 51 . The thermally conductive material could be a diced piece of metal, such as copper, or a non-electrically conducting elastomeric material. The thermally conductive material may also be placed upon the upper face of the top pad, while flat and prior to leadframe bending. A half-etch recess (not shown) may also be defined to aid alignment of the thermally conductive die.
In the example shown, the process for assembling the package is substantially the same as described for other embodiments, but with the additional step of placing the die 80 onto the chip 51 before the cover is folded over. Thermal performance is thereby improved by providing a low thermally resistive path to the top and bottom package boundaries.
This method is particularly suitable for medium to large sized die where there is sufficient surface area to safely mount the die of thermally conductive material without disrupting peripheral wirebonds.
As previously shown in and discussed for FIG. 11 , die may be stacked. FIG. 22 shows a further embodiment of the invention where multiple (four-shown) semiconductor die 51 a - d have been stacked using a combination of standard assembly techniques such as flip-chip and wirebond. FIG. 22 shows a cross-section dissecting the package centre. The package provides both a thermally enhanced and EMI screened MLP packaging solution for multiple chips. The top die 51 d (flip-chip mounted) has a direct connection the package's top metal pad thus providing an excellent route to dissipate heat away from the die stack.
This type of package can be assembled in the same manner as for a single chip package but with the following additional steps. After the first chip 51 a has been mounted a variety of techniques can be used to mount the other chips, including thinned die, thinned die attach and spacing methods, and low-profile wire bonding techniques. The additional chips can stacked face up and wire bonded, as for 51 b and 51 c . The chips can also be flip-chip mounted as detailed above. The chips may be wire bonded onto a common package, as shown here, or wire bonded die-to-die. Edge connectors (not shown) can also be used to connect multiple dies to a common mounting. Vias in the chips could also be used to provide interconnection.
The finished leadframe package can itself be stacked.
Further aspects of the invention incorporate surface mount technology (SMT) and passive components into the MLP package.
FIG. 23 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with integrated SMT passive components, in this example a leadframe based System-in-Package (SiP) solution. As discussed above the MLP package can be equipped with a top metal pad cover 60 . Recesses 84 , here indicated by a dotted line, can be defined in the cover. The recess can extend the cover to provide a connection to the SMP passive
The package is assembled in the manner described above. Discrete components such as surface mount capacitors or resistors are arranged to fit within these recesses. These components may be supportive to the correct function of the semiconductor die. Integrated passive networks can be deployed using, for example, ceramic substrate, GaAs or silicon thin film technology. Such integrated passive networks are often used in filter circuits and other RF applications.
The profile of the recesses 84 cut in the top pad can be varied to provide sufficient depth for the passive components to be fixed in place.
FIG. 24 , for example, shows how a recess 84 has been cut in the package's top metal pad, adapting it to give sufficient clearance to allow the larger support components and secondary die to retain the accepted standard height. The embodiment shown can be further modified to form a simultaneous electrical connection to both the package top pad and a bottom signal pin enhancing thermal performance and EMI protection.
Further embodiments of the invention incorporate enhanced EMI features into the MLP package.
A cross-sectional and plan view of an EMI enhanced package and its mounting are shown respectively in FIGS. 25 and 26 . In these examples, the top metal pad 60 has been enlarged and fabricated with additional fold lines 86 using the same process as that used to define the bend points discussed previously, for example for FIGS. 9 and 10 .
The fold lines define sidewalls 88 . In the embodiment shown in FIGS. 25 and 26 , the leadframe top metal pad 60 , while still flat, can be shaped by various means, for example a mechanical stamp tool, to form the sides and the base of an up-turned open box. After subassembly, the formed box could, as with the principal embodiment's top metal pad, be bent up and over the mounted die subassembly. The combined box shape and interconnecting vertical structure equipped with the key bend points act as an electrically grounded EMI shield. As shown in FIG. 26 , the boxed sidewalls 88 could be designed to maintain clearance or, where contact is required, provide a good electrical connection to the perimeter or centre ground pads of the leadframe base.
With reference to FIG. 26 , the larger top pad with defined fold lines is shown lying flat. The final package dimension is indicated by dashed lines. Defined bend points are indicated by dotted lines. Perimeter cut-outs or reliefs can be designed to optimise space around sensitive electrical pins. The top metal pad is equipped with sidewalls 88 which are arranged to allow sufficient access for the plastic mould material.
The assembly of the enhanced EMI protection package shown in FIGS. 25 and 26 follows the same steps as the other packages described above but with an additional step of bending the cover 60 at bend lines 88 to form the sidewalls 88 .
FIGS. 27 to 36 illustrate further aspects of the invention featuring an aperture in the MLP package, where it is advantageous to gain access by various means to the surface of the semiconductor chip.
In particular, FIGS. 27 to 34 show embodiments for the packaging of image sensor semiconductor chips 91 for use in imaging systems, for example digital camera applications. Such devices require a window 96 in the package allowing light to fall onto the chip surface. Image sensor chips are equipped with arrays of receptors capable of capturing the light and passing this information as an electrical signal to the system.
The cover 98 is equipped with an aperture to provide a semi-rigid frame or support for the holding and mounting of the glass and/or lens. The package offers an optimised, cheap and low profile solution overcoming many of the assembly issues reported by image sensor manufacturers. For example, correct alignment of components such as lenses in optical systems is important to quality control. Furthermore, assembly of the different components needed to make such an optical system can be intricate and time consuming, increasing manufacturing costs.
FIG. 27 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with an aperture feature. In this example, a “die” 100 of transparent material has been fixed upon the surface of the semiconductor chip using standard assembly techniques. Here a half-etch recess 102 has been used to aid glass die alignment and adhesion. The transparent material could be a cut piece of glass, a pre-shaped lens, a combination of both of these. The package body mould material could also be transparent.
FIGS. 28 and 29 respectively show a square or round “window” 96 could be defined in the top metal pad. If a square glass die (for example IR filter, Borosilicate, or pre-shaped lens) is used it may be placed upon the upper or lower face of the top pad, while flat, and prior to leadframe bending, thus simplifying the assembly process for this type of device.
This type of package construction is particularly suitable for medium-larger sized die where there is sufficient chip area to safely mount the glass die without disrupting peripheral wirebonds.
A transparent epoxy of a similar refractive index to the glass is recommended for fixing the glass to the semiconductor and leadframe surfaces.
FIG. 30 shows a side elevation, cross-sectional view of an MLP-type package according to the invention with an aperture feature fitted with a lens 104 . In this example, showing the cross-sectional ellipse of a lens made of transparent material, the lens has been fixed to the outer surface of the top metal pad using standard assembly techniques. A half-etch recess 106 around the aperture has been used to aid lens alignment and adhesion. The space between the lens underside and semiconductor chip surface is filled with a transparent material 108 such as an epoxy.
The semiconductor and lens package can be assembled from a mounting with an aperture in the top pad as follows. A semiconductor chip 91 can be placed on a mounting using the standard techniques described before. The individual mounts are then folded through a nominal angle of 90° along each of the fold lines 70 so that the cover 98 extends over the chip 91 , parallel to the base 52 and connectors 54 . The transparent material, 108 can be injected to fill the void between the chip 91 and aperture 96 .
Alternatively it can be applied to the chip 91 before folding of the mounting. The sealing material 55 is then injected between the cover and the chip 91 . The lens 104 is then fixed to the assembly, using the recess 106 to align the lens correctly to the chip 91 .
FIG. 31 shows a top plan view of a round “window” 96 can be defined in a double metal pad 110 arrangement. FIGS. 32 and 33 shows how this double pad 110 in the leadframe can be alternatively formed to hold a square glass die 98 and/or pre-shaped (round) lens 102 . This general method and form for holding a single square glass die and/or pre-shaped lens may be extended to provide a structure to hold multiple lenses or die. This type of assembly can be used where there is a need for a complex lens/optical system assembly, for example, combining lenses with optical filters.
The packages shown in FIGS. 32 and 33 offer an improved method of assembly. As before, beginning from a flat mounting, for example that shown in FIG. 31 , the chip is fixed and connected to the mounting and the square die attached to the chip 91 . The lens 102 is placed on the double pad 110 , on the round aperture 92 . The lens can be secured into place using the recess 106 for alignment. The double pad is folded along fold lines 70 as before, bending a first pad over the chip 91 and die 98 as previously described. The portion holding the lens 102 is then bent back over the first pad such that the lens is held between the first and second top pads. The two apertures in the pad are aligned such that the edges of the aperture of the lower top pad form lower edges to align the lens. This procedure allows the lens assembly to be easily assembled and correctly aligned.
Furthermore, the open aperture type of MLP package can be deployed in sensor applications, for example for use in biometrics applications.
FIGS. 34 and 35 show two such embodiments of the invention for biometrics systems. In FIG. 35 the top metal pad is attached directly to the chip 111 using standard materials and techniques. The top surface 112 of the chip is exposed.
In many biometrics applications the top surface 112 of a protective coated semiconductor chip 111 needs to be exposed to allow an interface with the “real world”. An example is a fingerprint identification chip where the user's finger is placed upon the surface of the die.
The frame is designed to fully expose the semiconductor die sensor array without causing disruption to the peripheral wirebonds.
An alternative sensor embodiment is shown in FIG. 36 . This figure shows a side elevation, cross-sectional view of an MLP-type package with exposed die feature and gel-filled cavity 116 . This configuration can be used in, for example, pressure sensing applications. In such a pressure sensor the interface gel material 116 acts as a medium to track environmental pressure changes to the surface of the semiconductor chip. The gel material also acts to protect the sensitive die surface.
The inventions top metal pad is used to provide a supportive frame and desired opening allowing accurate forming of the gel material 116 .
The sensor package may be pre or post-moulded using the techniques previously described. The frame and gel window is configured to allow sufficient gel material to access the semiconductor die pressure sensor.
In a further embodiment, the cover of a chip package can be tailored to specific applications and needs, as illustrated in FIGS. 37 to 43 .
For example, FIG. 37 shows the further embodiment where the package is equipped with an internal top metal pad 60 acting as an EMI shield. The top metal pad structure 60 is surrounded by the mould material 55 and no external exposure of the top pad is provided. The mould material defines the outer boundary of the top of the package.
FIG. 38 shows a side elevation, cross-sectional view of an MLP-type package with a partially exposed top metal pad EMI shield.
In this example the package is equipped with a partially exposed top metal pad 60 . The top metal pad 60 provides a combined EMI shield and heat sink, shown here patterned with trenches 112 using the standard leadframe half-etch processes. The pattern formed by the trenches found in its outer surface 112 is designed to allow a controlled mould material ingress, improving manufacturability, and reliability by retaining the cover in place in the package. The patterned surface allows for improved interlocking of the pad 60 and mould material 55 .
The highest points of the patterned top pad can be arranged to remain exposed after moulding. A partial external exposure of the top pad is therefore provided. The top pad pattern may be designed to still provide sufficient exposed metal for access to the top metal pad. The mould material partially defines the outer boundary of the top of the package. Package reliability is enhanced through the use of the extra anchor points provided at the patterned upper side of the top metal pad.
FIG. 39 shows the cross-section of a package with the patterned trenches 126 underside of the top metal pad 60 . Reliability of the package structure may be enhanced through the use of a patterned underside of the top metal pad, allowing improved integrity of the mould and frame structure. The pattern could be designed as a combined series of half-etch channels, fully etched holes or full thickness recesses. The design of the pattern can optimised for mould access and flow and to avoid air/gas bubbles.
Other materials can also be combined in the MLP assembly. For example, FIG. 40 shows how a glob-top 130 or other suitable dielectric fill material may be dispensed over the active die surface and other subassembly structures (for example, wirebonds), prior to bending the top metal pad. This provides additional structural protection for the chips mounted in the package.
The electromagnetic coupling capabilities of the MLP package can also be further enhanced. For example, FIG. 41 shows how apertures or slots 130 are formed within the top metal pad to permit the electromagnetic coupling of waves of a certain frequency (wavelength) through the top metal pad. This structure may be of advantage for the mounting for a radio system's antenna or electromagnetic coupling to other popular microwave components such as filters and waveguides.
FIGS. 42 and 43 show how further stack constructions can be used to optimise thermal, electrical and EMI shielding in a multiple die stack. Here two chips 132 are shown mounted conventionally and a third chip 134 is flip-chip mounted and connected to them. The basic design of having a top metal pad is unchanged.
In FIG. 42 the base die attach pad has been etched to a partial thickness using the techniques already discussed and FIG. 43 shows how solder spheres may be used to connect a mother die to the peripheral package pads.
The EMI shielding discussed above can be adapted to meet the appropriate government regulations and to further meet the operating requirements of the mounted semiconductor assembly, for example to provide immunity from other interfering RF signals or allow operation of RF circuitry within the package. The package and mounting can be adapted to meet appropriate regulations for various and known wireless standards. Furthermore, such RF SiP solutions as discussed above can provide for integrated antenna means in the cover 60 .
The MLP packaging described above can be further adapted to include useful structures and functions.
For example, FIG. 44 shows how the top metal pad 60 can be defined with apertures to provide an inductive element 154 . In this example, a semiconductor chip 150 is shown mounted with its wirebonds 152 connecting the chip to peripheral base pins. The top pad structure 60 is etched in a serpentine pattern 154 to form a serpentine inductor. The inductor is formed about the two connecting formations 59 equipped with defined bend points 70 , (indicated by dotted lines) and thus sits above the mounted semiconductor once the package has been assembled as described above.
The example shown in FIG. 44 shows how the continuous serpentine path of the top metal pad 60 is designed to electrically and physically connect to peripheral or package base pins through two connecting formations 59 equipped with defined bend points. This connecting method provides a robust, reliable and low resistance connection to the inductive element 150 the two connecting formations may also be used to define the final package height.
Situating the inductive element in a parallel, upper plain above the semiconductor chip assembly and base/peripheral package pins further reduces the component package area.
The package design in the example shown in FIG. 44 also shows how wirebonds, or alternatively flip-chip connections, can be used to electrically connect the semiconductor chip to the peripheral package pins and base pads for connection to the inductive element.
When connected to a system neutral RF, for example, Ground or direct current Voltage Supply, the upper plain inductive element has the additional advantage of functioning as an integrated EMI shield and heatsink/heatspreader, as previously described above.
It is further possible to combine the inductive element with a further metal pad, as shown in FIG. 45 . In this example a second top metal pad 160 may be formed to fit over the semiconductor chip assembly and the inductive element. Electrical and physical isolation between the inductor and shield would be maintained. The separation between bend points in the single connecting formation connecting the top metal pad to the semiconductor ship die attach pad is greater than between those on the connecting formations for the inductor to provide sufficient final package height and to ensure that the cover is spaced from the inductor.
This approach to integrating inductive elements into the package can also be used for integrating other passive components such as capacitors, for example interdigitated capacitors. It would also be possible to extend the approach to help integrate other components such as microstrip couplers and filters.
FIG. 46 is a table of results of electromagnetic interference simulations for the package design shown in FIG. 2 . A series of comparative simulations were conducted on a standard package with no top metal pad and the improved package with the top metal pad 60 acting as a shield. Using recognised methods of emission type EMI simulation, monitor points were distributed at representative positions surrounding the package.
The packages shown in the above examples can be demonstrated to provide a local EMI shield. The simulations show improvements in shield effectiveness of approximately 10 dB at application frequencies of up to 10 GHz for the E field, and of approximately 20 dB for the H field. Effective EMI shielding is important for meeting regulations on electromagnetic emissions, especially considering the higher frequencies at which modern electronics equipment operates. It will be appreciated that several design factors, such as the spacing between the cover or top pad and the semiconductor chip, and the overhang of the top pad, can be optimized to improve shielding effectiveness. Further simulated results for larger packages have shown improved results for shield effectiveness up to 40 dB at frequencies of up to 10 GHz.
Computer simulations of thermal dissipation in the package show improvements over conventional packages. The structure and immediate environment of the package was simulated using computational fluid dynamics software. The die sizes, materials and constant power dissipations assumed are given in the table of FIG. 47 .
FIG. 48 is a table of results of thermal simulations for the multiple stacked die in a package as shown in FIG. 11 . In this example two daughter die are flip-chip mounted onto a third mother die. In such a package the top metal pad would be attached to the rear top side of the daughter die using conductive epoxy and the mother die would be attached to the package using conductive epoxy.
As can be seen from the table, the heat dissipation simulations show improvements in heat dissipation of approximately 21 degrees C., an improvement of 22%, in the daughter chips 62 , 63 compared to standard packaging configurations. The thermal energy produced by the daughter die is dissipated through the packages internal structure to the printed circuit board.
By improving the thermal dissipation qualities of the packaging it is possible to mount more semiconductor chips that consume more power and therefore generate more heat. For example, it would be possible to drive semiconductor chips at higher speeds without failure due to overheating.
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The invention provides a mounting for a printed circuit board which mounting is suitable for receiving a semiconductor assembly wherein the mounting comprises: a base support having a semiconductor assembly facing surface, and an opposed printed surface board facing surface; a cover having a semiconductor assembly facing surface, an opposed heat radiating surface; a connecting formation which joins the cover to the base support and provides an electrical and thermal communication between the cover and the base support wherein the connecting formation has a semiconductor assembly facing surface, an outer opposed surface and a thickness between the two surfaces; and a plurality of package connectors extending from the base support each of which package connectors have a printed surface board facing surface; an array of mountings; and a semiconductor package comprising a semiconductor assembly having one or more semiconductor chips, which assembly is mounted on the mounting wherein the package connectors of the mounting are in a spaced relationship with the base support and are linked electrically with the semiconductor assembly and the cover is arranged to be in a spaced parallel relationship with the base support.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 09/878,438 filed Jun. 11, 2001, now U.S. Pat. No. 6,440,953, which in turn is a continuation-in-part of U.S. patent application Ser. No. 09/657,828 filed Sep. 8, 2000, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to vitamin D compounds, and more particularly to 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol and its pharmaceutical uses.
The natural hormone, 1α,25-dihydroxyvitamin D 3 and its analog in ergosterol series, i.e. 1α,25-dihydroxyvitamin D 2 are known to be highly potent regulators of calcium homeostasis in animals and humans, and their activity in cellular differentiation has also been established, Ostrem et al., Proc. Natl. Acad. Sci. USA, 84, 2610 (1987). Many structural analogs of these metabolites have been prepared and tested, including 1α-hydroxyvitamin D 3 , 1α-hydroxyvitamin D 2 , various side chain homologated vitamins and fluorinated analogs. Some of these compounds exhibit an interesting separation of activities in cell differentiation and calcium regulation. This difference in activity may be useful in the treatment of a variety of diseases as renal osteodystrophy, vitamin D-resistant rickets, osteoporosis, psoriasis, and certain malignancies.
Recently, a new class of vitamin D analogs has been discovered, i.e. the so called 19-nor-vitamin D compounds, which are characterized by the replacement of the A-ring exocyclic methylene group (carbon 19), typical of the vitamin D system, by two hydrogen atoms. Biological testing of such 19-nor-analogs (e.g., 1α,25-dihydroxy-19-nor-vitamin D 3 ) revealed a selective activity profile with high potency in inducing cellular differentiation, and very low calcium mobilizing activity. Thus, these compounds are potentially useful as therapeutic agents for the treatment of malignancies, or the treatment of various skin disorders. Two different methods of synthesis of such 19-nor-vitamin D analogs have been described (Perlman et al., Tetrahedron Lett. 31, 1823 (1990); Perlman et al., Tetrahedron Lett. 32, 7663 (1991), and DeLuca et al., U.S. Pat. No. 5,086,191).
In U.S. Pat. No. 4,666,634, 2β-hydroxy and alkoxy (e.g., ED-71) analogs of 1α,25-dihydroxyvitamin D 3 have been described and examined by Chugai group as potential drugs for osteoporosis and as antitumor agents. See also Okano et al., Biochem. Biophys. Res. Commun. 163, 1444 (1989). Other 2-substituted (with hydroxyalkyl, e.g., ED-120, and fluoroalkyl groups) A-ring analogs of 1α,25-dihydroxyvitamin D 3 have also been prepared and tested (Miyamoto et al., Chem. Pharm. Bull. 41, 1111 (1993); Nishii et al., Osteoporosis Int. Suppl. 1, 190 (1993); Posner et al., J. Org. Chem. 59, 7855 (1994), and J. Org. Chem. 60, 4617 (1995)).
Recently, 2-substituted analogs of 1α,25-dihydroxy-19-nor-vitamin D 3 have also been synthesized, i.e. compounds substituted at 2-position with hydroxy or alkoxy groups (DeLuca et al., U.S. Pat. No. 5,536,713), with 2-alkyl groups (DeLuca et al U.S. Pat. No. 5,945,410), and with 2-alkylidene groups (DeLuca et al U.S. Pat. No. 5,843,928), which exhibit interesting and selective activity profiles. All these studies indicate that binding sites in vitamin D receptors can accommodate different substituents at C-2 in the synthesized vitamin D analogs.
In a continuing effort to explore the 19-nor class of pharmacologically important vitamin D compounds, an analog which is characterized by the presence of a methylene substituent at the carbon 2 (C-2) has been synthesized and tested. Of particular interest is the analog which is characterized by a hydroxyl group at carbon 1 and a shortened side chain attached to carbon 20, i.e. 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol. This vitamin D analogs seemed an interesting target because the relatively small methylene group at C-2 should not interfere with the vitamin D receptor. Moreover, molecular mechanics studies performed on the model 1α-hydroxy-2-methylene-19-nor-vitamins indicate that such molecular modification does not change substantially the conformation of the cyclohexanediol ring A. However, introduction of the 2-methylene group into 19-nor-vitamin D carbon skeleton changes the character of its 1α- and 3β-A-ring hydroxyls. They are both now in the allylic positions, similarly, as 1α-hydroxyl group (crucial for biological activity) in the molecule of the natural hormone, 1α,25-(OH) 2 D 3 .
SUMMARY OF THE INVENTION
The present invention is directed toward 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol, its biological activity, and various pharmaceutical uses for this compound.
Structurally this 19-nor analog is characterized by the general formula I shown below:
The above compound exhibits a desired, and highly advantageous, pattern of biological activity. This compound is characterized by relatively high binding to vitamin D receptors, but very low intestinal calcium transport activity, as compared to that of 1α,25-dihydroxyvitamin D 3 , and has very low ability to mobilize calcium from bone, as compared to 1α,25-dihydroxyvitamin D 3 . Hence, this compound can be characterized as having little, if any, calcemic activity. However, its apparent ability to also suppress production of parathyroid hormone (PTH) makes this compound an ideal candidate for use as a therapeutic agent for the treatment of renal osteodystrophy.
The compound of the invention has also been discovered to be especially suited for treatment and prophylaxis of human disorders which are characterized by an imbalance in the immune system, e.g. in autoimmune diseases, including multiple sclerosis, lupis, diabetes mellitus, host versus graft reaction, and rejection of organ transplants; and additionally for the treatment of inflammatory diseases, such as rheumatoid arthritis, asthma, and inflammatory bowel diseases such as celiac disease and croans disease, as well as the improvement of bone fracture healing and improved bone grafts. Acne, alopecia and hypertension are other conditions which may be treated with the compound of the invention.
The above compound is also characterized by relatively high cell differentiation activity. Thus, this compound also provides a therapeutic agent for the treatment of psoriasis, or as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer and prostate cancer. In addition, due to its relatively high cell differentiation activity, this compound provides a therapeutic agent for the treatment of various skin conditions including wrinkles, lack of adequate dermal hydration, i.e. dry skin, lack of adequate skin firmness, i.e. slack skin, and insufficient sebum secretion. Use of this compound thus not only results in moisturizing of skin but also improves the barrier function of skin.
The compound may be present in a composition to treat the above-noted diseases and disorders in an amount from about 0.01 μg/gm to about 100 μg/gm of the composition, and may be administered topically, transdermally, orally or parenterally in dosages of from about 0.01 μg/day to about 100 μg/day.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the relative activity of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol and 1α,25-dihydroxyvitamin D 3 to compete for binding of [ 3 H]-1,25-(OH) 2 -D 3 to the vitamin D pig intestinal nuclear receptor;
FIG. 2 is a graph illustrating the intestinal calcium transport activity of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol as compared to 1α,25-dihydroxyvitamin D 3 ;
FIG. 3 is a graph illustrating the bone calcium mobilization activity of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol as compared to 1α,25-dihydroxyvitamin D 3 ;
FIG. 4 is a graph illustrating the percent HL-60 cell differentiation as a function of the concentration of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol and of 1α,25-dihydroxyvitamin D 3 ;
FIG. 5 is a graph illustrating the transcriptional activity in bone cells of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol as compared to 2-methylene-19-nor-20(S)-1α,25-dihydroxyvitamin D 3 and to 1α,25-dihydroxyvitamin D 3 ;
FIG. 6 is a graph illustrating the transcriptional activity in kidney cells of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol as compared to 2-methylene-19-nor-20(S)-1α,25-dihydroxyvitamin D 3 and to 1α,25-dihydroxyvitamin D 3 ; and
FIG. 7 is a bar graph illustrating blood serum calcium levels in male rats after treatment with a single dose of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol as compared to 1α,25-dihydroxyvitamin D 3 and to 2-methylene-19-nor-20(S)-1α,25-dihydroxyvitamin D 3 .
DETAILED DESCRIPTION OF THE INVENTION
1α-hydroxy-2-methylene-19-nor-homopregnacalciferol (referred to herein as 2 MHP) was synthesized and tested. Structurally, this 19-nor analog is characterized by the general formula I previously illustrated herein.
The preparation of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol having the basic structure I can be accomplished by a common general method, i.e. the condensation of a bicyclic Windaus-Grundmann type ketone 11 with the allylic phosphine oxide III to the corresponding 2-methylene-19-nor-vitamin D analog IV followed by deprotection at C-1 and C-3 in the latter compound:
In the structures II, III, and IV groups Y 1 and Y 2 are hydroxy-protecting groups, it being also understood that any functionalities that might be sensitive, or that interfere with the condensation reaction, be suitably protected as is well-known in the art. The process shown above represents an application of the convergent synthesis concept, which has been applied effectively for the preparation of vitamin D compounds [e.g. Lythgoe et al., J. Chem. Soc. Perkin Trans. I, 590 (1978); Lythgoe, Chem. Soc. Rev. 9, 449 (1983); Toh et al., J. Org. Chem. 48, 1414 (1983); Baggiolini et al., J. Org. Chem. 51, 3098 (1986); Sardina et al., J. Org. Chem. 51, 1264 (1986); J. Org. Chem. 51, 1269 (1986); DeLuca et al., U.S. Pat. No. 5,086,191; DeLuca et al., U.S. Pat. No. 5,536,713].
Hydrindanones of the general structure 11 are known, or can be prepared by known methods.
For the preparation of the required phosphine oxides of general structure III, a new synthetic route has been developed starting from a methyl quinicate derivative which is easily obtained from commercial (1R,3R,4S,5R)-(−)-quinic acid as described by Perlman et al., Tetrahedron Lett. 32, 7663 (1991) and DeLuca et al., U.S. Pat. No. 5,086,191.
The overall process of the synthesis of compound I is illustrated and described more completely in U.S. application Ser. No. 09/370,966 filed Aug. 10, 1999 entitled “2-Alkylidene-19-Nor-Vitamin D Compounds” the specification of which is specifically incorporated herein by reference.
Biological Activity of 1α-Hydroxy-2-Methylene-19-nor-Homopregnacalciferol
The introduction of a methylene group to the 2-position of 1α-hydroxy-19-nor-homopregnacalciferol had little or no effect on binding to the porcine intestinal vitamin D receptor, as compared to 1α,25-dihydroxyvitamin D 3 . This compound bound equally well to the porcine receptor as compared to the standard 1,25-(OH) 2 D 3 (FIG. 1 ). It might be expected from these results that this compound would have equivalent biological activity. Surprisingly, however, the 2 methylene substitution produced a highly selective analog with unique biological activity.
Table 1 and FIG. 2 show that 2 MHP has very little activity as compared to that of 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ), the natural hormone, in stimulating intestinal calcium transport.
Table 1 and FIG. 3 demonstrate that 2 MHP has very little bone calcium mobilization activity, as compared to 1,25(OH) 2 D 3 .
FIGS. 2 and 3 thus illustrate that 2 MHP may be characterized as having little, if any, calcemic activity.
FIG. 4 illustrates that 2 MHP is almost as potent as 1,25(OH) 2 D 3 on HL-60 differentiation, making it an excellent candidate for the treatment of psoriasis and cancer, especially against leukemia, colon cancer, breast cancer and prostate cancer. In addition, due to its relatively high cell differentiation activity, this compound provides a therapeutic agent for the treatment of various skin conditions including wrinkles, lack of adequate dermal hydration, i.e. dry skin, lack of adequate skin firmness, i.e. slack skin, and insufficient sebum secretion. Use of this compound thus not only results in moisturizing of skin but also improves the barrier function of skin.
FIG. 5 illustrates that 2 MHP has transcriptional activity in bone cells while FIG. 6 illustrates 2 MHP has transcriptional activity in kidney cells. These data provide further support for the VDR binding data in FIG. 1 . Transcriptional activity was measured in two different cell lines. ROS 17/2.8 (bone) or LLC (kidney) cells were stably transfected with a 24-hydroxylase (240Hase) gene promoter upstream of a luciferase reporter gene (Arbour et al, 1998). Cells were given a range of doses. Sixteen hours after dosing the cells were harvested and luciferase activities were measured using a luminometer. The EC 50 of 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol is about 10 times lower in bone cells than kidney cells. In kidney cells, 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol is greater than or equivalent to 1,25(OH) 2 D 3 . The graphs of FIGS. 5 and 6 are representative of 4 to 5 independent experiments. In FIGS. 5 and 6, RLU means relative luciferase units.
Table 2 and FIG. 7 show an analysis of serum calcium in rats both before and after administration of a single dose of 2 MHP. These data provide further support for the data in FIG. 3 .
Competitive binding of the analogs to the porcine intestinal receptor was carried out by the method described by Dame et al (Biochemistry 25, 4523-4534, 1986).
The differentiation of HL-60 promyelocytic into monocytes was determined as described by Ostrem et al (J. Biol. Chem. 262, 14164-14171, 1987).
Interpretation of Data
The in vivo tests to determine serum calcium of rats on a zero calcium diet provides an insight to osteoblastic or bone activity of 2 MHP. The dose response curves show that 2 MHP is significantly less potent than 1,25(OH) 2 D 3 in raising calcium in the plasma via the stimulation of the osteoblasts (FIG. 3 and FIG. 7 ). At the same time, the activity of 2 MHP on intestinal calcium transport is also significantly less than that of 1,25-(OH) 2 D 3 (FIG. 2 ). Therefore, these data show 2 MHP to have little, if any, activity on bone. 2 MHP is slightly less active than 1,25(OH) 2 D 3 in binding to the vitamin D receptor (FIG. 1 ), and has significant transcriptional activity in both bone cells (FIG. 5) and kidney cells (FIG. 6 ). However, it is also only slightly less active than 1,25-(OH) 2 D 3 in causing differentiation of the promyelocyte, HL-60, into the monocyte (FIG. 4 ). This result suggests that 2 MHP will be very effective in psoriasis because it has direct cellular activity in causing cell differentiation and in suppressing cell growth. It also indicates that it will have significant activity as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer and prostate cancer, as well as against skin conditions such as dry skin (lack of dermal hydration), undue skin slackness (insufficient skin firmness), insufficient sebum secretion and wrinkles.
These results illustrate that 2 MHP is an excellent candidate for numerous human therapies and that it may be useful in a number of circumstances such as autoimmune diseases, cancer, and psoriasis. Since 2 MHP has significant binding activity to the vitamin D receptor, but has little ability to raise blood serum calcium, and yet has the ability to suppress PTH production, it may also be useful for the treatment of renal osteodystrophy.
Male, weanling Sprague-Dawley rats were placed on Diet 11 (0.47% Ca) diet+AEK for 11 days, followed by Diet 11 (0.02% Ca)+AEK for 31 days. Dosing (i.p.) began 7 days prior to sacrifice. Doses were given on a daily basis, 24 hours apart. The first 10 cm of the intestine was collected for gut transport studies and serum was collected for bone Ca mobilization analysis. The results are reported in Table 1 and illustrated in the graph of FIG. 2 .
TABLE 1
Response of Intestinal Calcium Transport and Serum Calcium (Bone
Calcium Mobilization) Activity to Chronic Doses of 1,25(OH) 2 D 3
and 2MHP
Intestinal Calcium
Serum
Dose
Transport*
Calcium*
Group
(pmol/day/7 days)
(S/M)
(mg/100 ml)
Vitamin D Deficient
Vehicle
3.28 ± 0.64
3.72 ± 0.32
1,25-(OH) 2 D 3
250
5.21 ± 0.73
7.40 ± 0.47
1,25-(OH) 2 D 3
500
6.85 ± 0.79
7.20 ± 0.33
2MHP
250
3.22 ± 0.14
4.84 ± 0.37
2MHP
500
3.90 ± 0.38
3.96 ± 0.19
*The above data are the average and standard error (SE) from 5 animals.
Weanling, male Sprague-Dawley rats (6/group) were placed on a vitamin D-deficient diet for a total of 5 weeks. During the first three weeks, the animals were fed a normal calcium diet (Diet 11+0.47% Ca+AEK supplement) and the last two weeks they were fed a low calcium diet (Diet 11+0.02% Ca+AEK supplement). Approximately 24 hours prior to sacrifice, animals were tail bled and then dosed with 1 nmol of the respective compounds. The doses were delivered orally in 100 microliters of vegetable oil by gavage. Serum was collected approximately 24 hour post-dose and it, along with the pre-dose serum, were subjected to total calcium analysis using atomic absorption spectrometry. These data are reported below in Table 2 and illustrated in the graph of FIG. 7 .
TABLE 2
Pre-Dose and Post-Dose Response of Serum Calcium
(Bone Mobilization) Activity to a Single Dose of 1,25(OH) 2 D 3
and of 2MHP and of 2-Methylene-19-Nor-20(S)-1,25(OH) 2 D 3
Treatment
Pre-Dose*
SE
Post-Dose*
SE
Vehicle
4.70
0.08
4.64
0.12
1,25(OH) 2 D 3
4.51
0.05
5.42
0.09
1α-hydroxy-2-methylene-19-
4.86
0.13
4.36
0.16
nor-homopregnacalciferol
(20S)-1α,25(OH) 2 -2-methylene-
4.45
0.06
7.33
0.15
19-nor-vitamin D 3
*The above are the average and standard error (SE) from 6 animals.
For treatment purposes, the compound of this invention defined by formula I may be formulated for pharmaceutical applications as a solution in innocuous solvents, or as an emulsion, suspension or dispersion in suitable solvents or carriers, or as pills, tablets or capsules, together with solid carriers, according to conventional methods known in the art. Any such formulations may also contain other pharmaceutically-acceptable and non-toxic excipients such as stabilizers, anti-oxidants, binders, coloring agents or emulsifying or taste-modifying agents.
The compound may be administered orally, topically, parenterally or transdermally. The compound is advantageously administered by injection or by intravenous infusion or suitable sterile solutions, or in the form of liquid or solid doses via the alimentary canal, or in the form of creams, ointments, patches, or similar vehicles suitable for transdermal applications. Doses of from 0.01 μg to 100 μg per day of the compounds are appropriate for treatment purposes, such doses being adjusted according to the disease to be treated, its severity and the response of the subject as is well understood in the art. Since the compound exhibits specificity of action, each may be suitably administered alone, or together with graded doses of another active vitamin D compound—e.g. 1α-hydroxyvitamin D 2 or D 3 , or 1α,25-dihydroxyvitamin D 3 —in situations where different degrees of bone mineral mobilization and calcium transport stimulation is found to be advantageous.
Compositions for use in the above-mentioned treatments comprise an effective amount of the 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol as defined by the above formula I as the active ingredient, and a suitable carrier. An effective amount of such compound for use in accordance with this invention is from about 0.01 μg to about 100 g per gm of composition, and may be administered topically, transdermally, orally or parenterally in dosages of from about 0.01 μg/day to about 100 μg/day.
The compound may be formulated as creams, lotions, ointments, topical patches, pills, capsules or tablets, or in liquid form as solutions, emulsions, dispersions, or suspensions in pharmaceutically innocuous and acceptable solvent or oils, and such preparations may contain in addition other pharmaceutically innocuous or beneficial components, such as stabilizers, antioxidants, emulsifiers, coloring agents, binders or taste-modifying agents.
The compound is advantageously administered in amounts sufficient to effect the differentiation of promyelocytes to normal macrophages. Dosages as described above are suitable, it being understood that the amounts given are to be adjusted in accordance with the severity of the disease, and the condition and response of the subject as is well understood in the art.
The formulations of the present invention comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredients. The carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof.
Formulations of the present invention suitable for oral administration may be in the form of discrete units as capsules, sachets, tablets or lozenges, each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution or a suspension in an aqueous liquid or non-aqueous liquid; or in the form of an oil-in-water emulsion or a water-in-oil emulsion.
Formulations for rectal administration may be in the form of a suppository incorporating the active ingredient and carrier such as cocoa butter, or in the form of an enema.
Formulations suitable for parenteral administration conveniently comprise a sterile oily or aqueous preparation of the active ingredient which is preferably isotonic with the blood of the recipient.
Formulations suitable for topical administration include liquid or semi-liquid preparations such as liniments, lotions, applicants, oil-in-water or water-in-oil emulsions such as creams, ointments or pastes; or solutions or suspensions such as drops; or as sprays.
For asthma treatment, inhalation of powder, self-propelling or spray formulations, dispensed with a spray can, a nebulizer or an atomizer can be used. The formulations, when dispensed, preferably have a particle size in the range of 10 to 100μ.
The formulations may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. By the term “dosage unit” is meant a unitary, i.e. a single dose which is capable of being administered to a patient as a physically and chemically stable unit dose comprising either the active ingredient as such or a mixture of it with solid or liquid pharmaceutical diluents or carriers.
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This invention discloses 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol and pharmaceutical uses therefor. This compound exhibits pronounced activity in arresting the proliferation of undifferentiated cells and inducing their differentiation to the monocyte thus evidencing use as an anti-cancer agent and for the treatment of skin diseases such as psoriasis as well as skin conditions such as wrinkles, slack skin, dry skin and insufficient sebum secretion. This compound also has little, if any, calcemic activity and therefore may be used to treat immune disorders in humans as well as renal osteodystrophy.
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TECHNICAL FIELD OF APPLICATION
[0001] The invention relates to a radar sensor, a radar sensor system and to a method for determining the position of an object.
[0002] Millimetre wave radar sensors, e.g. for automotive and aeronautical applications, should exhibit a compact and inexpensive construction.
[0003] If the detection is restricted to just one plane (mostly the horizontal plane), as is the case with most automotive radar sensors, this can take place inexpensively by using planar antennas and a number of receivers. The beam formation and control take place here by the principle of “digital beamforming”.
[0004] However, for some applications precise vertical and horizontal position determination are required. This applies, for example, to a sensor system for monitoring the door area of motor vehicles of which the doors can open automatically. Here the sensor must detect potential obstacles so that any collision with the opening door is avoided. These obstacles can be positioned anywhere within the range of the vehicle height.
[0005] Another application is so-called parking assistance with which, for example, a distinction must be made between potentially colliding objects and low curbstones.
[0006] A distinction can essentially be made between the reflection behaviour of planar and of punctiform reflectors in that planar surfaces only exhibit significant reflection when the incident radar beam is vertical, whereas with punctiform reflectors this incident beam can also be at other angles. This fact may lead to the contour of extensive planar surfaces not being recognised, and a collision may occur, in particular, with automatically opening doors.
PRIOR ART
[0007] From the dissertation of Dr. Winfried Mayer entitled “Imaging radar sensor with group antenna connected on the transmitting side”, Cuvillier Verlag, Gottingen 2008, ISBN 978-3-86727-565-1/1/a method and an apparatus are known which monitor an area by the technique of digital beam formation in which an antenna array with a number of transmitters and a number of receivers is used.
[0008] In DE 10 2008 052 246 A1 a sensor system with an adjustable elevation beam direction for determining the vertical position of objects is described. The adjustment takes place here by the mechanical movement of a reflector.
[0009] In PCT/EP2012/003702 an imaging radar sensor with synthetic enlargement of the antenna aperture and two-dimensional beam scanning is described. The two-dimensional beam scanning takes place here in the horizontal by digital beam formation from a number of reception channels, and in the vertical by comparing the amplitudes of two received signals which are generated by two transmitters which have an antenna diagram tilted towards one another in the vertical. However, in practice this method is associated with the disadvantage that the amplitude characteristics of the antenna diagrams are distorted by structures upstream of the sensor such as radomes, plastic bumpers or door sills. This means that depending on the barrier, calibration of the radar sensor is to be performed in order to detect these distortions metrologically and to compensate for them.
DESCRIPTION OF THE INVENTION
[0010] The object of the invention is to make available an apparatus, a method and a radar system by means of which the disadvantages described above are avoided. Furthermore, it is the object of the invention to make available a radar sensor and a radar sensor system and an apparatus and a method by means of which a vertical position of an object can be determined and with the aid of which classification distinguishing between punctiform and flat objects can be performed.
[0011] According to the apparatus the object is achieved with the features of Claim 1 or 13 , and according to the method with the features of Claim 18 or 19 .
[0012] The following possible solutions are relevant to the invention, for example by means of an
A. apparatus for determining the position of an object three-dimensionally, comprising at least two radar transmitting/receiving devices, each device having at least 4 receivers and one or two transmitters, with an antenna array for horizontal beam scanning and which has a fan-shaped beam in the vertical, and an antenna array for vertical beam scanning, the individual emitting elements of which have wide directional characteristics in the vertical and in the horizontal, B. an apparatus for determining the position of an object three-dimensionally, comprising a row of transmitting antennas and a row of receiving antennas, characterised in that the two rows of antennas are arranged orthogonally to one another, an evaluation unit which generates a virtual array from the sequential received signals from the individual transmitters, the antenna beam of which can be controlled electronically both in the vertical and in the horizontal,
or a
C. radar system for the use of an apparatus for determining a position of an object three-dimensionally in accordance with A and B, consisting of two transmitting/receiving devices that are independent of one another for horizontal and vertical beam scanning, D. a radar system for the use of an apparatus for determining a position of an object three-dimensionally in accordance with B, consisting of at least 4 transmitters and 8 receivers which are synchronised with one another and so allow two-dimensional beam scanning of an individual antenna beam,
and furthermore
E. a radar system wherein the individual beam elements are arranged within the transmitter and the receiver at an angle of 45 degrees and so both the transmitter and the receiver have the same polarisation; F. a radar sensor arrangement for distinguishing between punctiform and flat reflectors, characterised in that the detection ranges of the two sensors overlap, and that the sensors are arranged lying opposite one another, preferably with a
[0021] G. method for determining a position of an object that comprises the procedural steps:
transmitting and receiving signals with the aid of antennas with an antenna beam in the form of a fan in the vertical direction, combining the received signals by the method of digital beam formation to form a number of bundled antenna beams in the horizontal direction, transmitting and receiving signals with wide antenna beams in the vertical and the horizontal direction, the antennas being arranged orthogonally to the antennas with a fan-shaped beam, combining these signals by the method of digital beam formation to form a number of bundled antenna beams in the vertical direction, displaying the horizontal and the vertical position of the object and/or a H. method for determining a position of an object with an apparatus according to Claim 2 , comprising the procedural steps:
sequentially transmitting signals with a row of transmitters, and simultaneously receiving the beams reflected on objects with a row of receivers, combining the received signals by the method of two-dimensional digital beam formation to form a number of bundled antenna beams in the horizontal and the vertical direction, displaying the horizontal and the vertical position of the object.
[0031] By using a second radar sensor, among other things a corrective is provided which is arranged offset with respect to the first in the direction of travel. The sensors are linked to one another, and the information that is collected is evaluated by one of the two sensors by the master/slave principle.
[0032] Further configurations of the present invention are the subject matter of the sub-claims.
[0033] Advantageous configurations are illustrated by the following figures.
[0034] FIG. 1 shows the sensor arrangement on the vehicle with a horizontal field of vision for monitoring the opening range of the doors. The sensors are each fitted tilted by approx. 30 degrees and have a field of vision of approx. 110 degrees. At least 2 sensors are to be fitted on each side of the vehicle in order to cover the opening range of the doors optimally.
[0035] FIG. 2 shows the vertical field of vision of the sensors and the range of potential obstacles.
[0036] The arrangement of the sensors has been chosen so that on the one hand the opening range of the doors is covered maximally, and on the other hand so that punctiform reflectors can be distinguished from flat reflectors. Overlapping of the fields of vision of the sensors is required for this purpose.
[0037] With punctiform objects the door may open up to the object, whereas with flat obstacles, such as for example walls or vehicles parked adjacent, the door may only open to the potentially extended surface.
[0038] In FIG. 3 the detection of a punctiform reflector, and in FIG. 4 the detection of a planar, flat object is sketched.
[0039] The distance and the angle of the punctiform object is detected by both sensors. However, with flat, planar objects only reflections occur with a perpendicular angle of incidence. Neither of the sensors is capable of detecting one and the same reflection point. The radar sensors detect the radial distance and the angle in relation to the point of reflection. If one now forms the orthogonals to the beam directions of the individual sensors, the latter run approximately parallel with a surface target and cross with a point target. With the point target the doors may be opened up to its position, and with a surface target only up to the extended orthogonal. The doors are thus prevented from touching the wall when opened, even though the reflection point is further away than the collision point.
[0040] FIG. 5 shows the millimetre wave module of an individual radar sensor with an antenna arrangement. The sensor consists of a transmitting/receiving device ( 1 ) for the vertical scan and a transmitting/receiving device ( 2 ) for the horizontal scan. Every transmitting/receiving device consists of at least 4 receivers ( 3 a , 3 b ) and one or two transmitters ( 4 a , 4 b ). Since the required detection rate for the door monitoring is low in comparison to the measuring rate of the sensor, the sensor system can perform the vertical detection and the horizontal detection one after the other chronologically. This reduces costs because only one signal processing unit is required. Furthermore, the transmitting/receiving units are prevented from disrupting one another.
[0041] FIG. 6 shows the functional block diagram of the radar sensor. It consists of two highly integrated radar front ends, each with two transmitters and four receivers. Analogue to digital converters are already integrated into the receivers so that the latter can be connected directly to the signal processing unit—a multicore digital signal processor. The signal processor additionally performs the task of controlling the transmitting/receiving modules and operates the communication interface with the outside world, e.g. with the control electronics of the automatic door.
[0042] Preferably with the digital beam formation described in/1/with two transmitters and a number of receivers, the vertical and the horizontal angular position of the object to be detected is now determined and the distance from the object is measured. The individual transmitters of a pair of transmitters are operated one after the other chronologically here. The bringing together of the information from the two detection processes corresponds to the detection with just one transmitter and reception with a virtual array ( 3 a ′, 3 b ′) which is twice as great as the real array. The angle measuring accuracy can thus be increased by a factor of 2. If this is not required, the detection can also be operated with just one transmitter.
[0043] FIG. 7 shows the time diagram and the modulation form of an individual transmitting/receiving unit.
[0044] Here the frequency of the two transmitters is modulated alternately, linearly and in the form of saw teeth. This cycle is repeated n times. The distance from the object is determined from the sets of data of the individual modulation ramps with the aid of a Fast Fourier Transform (FFT). Afterwards these sets of data are arranged to form a spectrogram and a second FFT is calculated by means of the columns of the spectrogram matrix. The line position of this so-called range-Doppler matrix corresponds to the speed of the object, and the column position corresponds to the radial distance. The modulation frequency fm is greater than the maximum Doppler frequency that occurs, and so an independent and clear distance and speed measurement can be taken.
[0045] Horizontal Scan:
[0046] In order to cover the field of vision illustrated in FIGS. 1 and 2 an antenna line has been chosen which has the vertical diagram shown in FIG. 8 . The arrangement and dimensioning of the individual emitter elements of the antenna line has not been optimised here to the maximum beam bundling as is otherwise normal, but is designed so that an upwardly directed fan-shaped beam is formed. This fan-shaped beam ensures that reflections of objects which are suppressed when they lie beneath the door sill and the sensor can also still detect objects with high vertical angles. The gain of this type of antenna line corresponds approximately to only that of an individual emitter. However, the distance from the objects is so small that the radar sensor is still sufficiently sensitive.
[0047] The horizontal diagram of this antenna line is illustrated in FIG. 9 . It has a very large 3 dB beam width in order to illuminate the required wide range of vision of 110°. After the digital beam formation the array diagram shown in FIG. 10 is produced which can be swivelled by up to +50° without so-called grating lobes being produced which could lead to dummy targets.
[0048] Vertical Scan:
[0049] Here, it is not antenna lines, but rather just a single emitter element—a so-called microstrip patch emitter—that is used. This emitter has a large opening angle in both the vertical and the horizontal (see FIG. 11 ). The digital beam scanning is restricted here to the angle range of-70° to 0°. At −70° dummy targets occur in the opposite direction. However, these would lie physically beneath the surface of the road, and so can be eliminated by a simple plausibility test. Up to a swivel angle of −60° the detection is free from grating lobes, and so from dummy targets.
[0050] The door opening range is therefore monitored two-dimensionally by the alternately horizontal and vertical scan, and so protruding obstacles such as loading ramps, handrails or exterior mirrors of adjacent vehicles can also be recognised as obstacles.
[0051] Two-Dimensional Scan:
[0052] An alternative to a radar sensor with horizontal and vertical scan is a radar sensor with a two-dimensional scan with which a high bundling beam can be controlled in two spatial directions. FIG. 12 shows the millimetre wave module with two transmitting/receiving modules which make available 4 transmitters and 8 receivers. Here the transmitting antennas are arranged in a row orthogonal to the row of receiving antennas. The transmitting antennas should have the same polarisation direction here as the receiving antenna in order to guarantee the maximum system sensitivity. When the antennas are fed on the same level, as can be seen for example in FIG. 5 , with the necessary spacing of the transmitting/emitting elements a line run feeding the emitting elements would not be possible. In order to implement this the emitter elements have been tilted by 45° on the transmitter as well as on the receiver.
[0053] As an extension to the know method described, for example, in/1/, one can therefore generate the virtual reception array that is shown so that an array of 4×8 individual emitters is available for the signal processing. Within the framework of the signal evaluation the phase and the amplitude of each of these individual emitters can be regulated so that beam scanning is possible in the vertical as well as in the horizontal direction.
[0054] FIG. 13 shows the controllable diagram of the array with a 3 dB beam width of 16 degrees in the horizontal and 29 degrees in the vertical.
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A radar sensor for a vehicle includes a control unit and an antenna array. The radar sensor is configured to perform a three-dimensional scan to determine a vertical and a horizontal position of an object in order to assist with distinguishing the geometrical nature of the object.
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TECHNICAL FIELD
[0001] The present disclosure relates to a gate drive device of a pixel array and a drive method thereof.
BACKGROUND
[0002] A liquid crystal display belongs to a display product of dynamic scanning type. When displaying one-frame picture, the liquid crystal display scans pixels one row by one row, and enables human eyes to feel a displayed one-frame picture by utilizing human eyes' visual residual effect, so as to realize displaying of the entire picture. Therefore, in the process of normal display of the liquid crystal display, at each time point, a gate line signal of only one gate line is a scanning signal (for example, high voltage) to scan its corresponding pixel row, while gate line signals of remaining gate lines are non-scanning signals (for example, low voltage).
[0003] However, when the liquid crystal display is started up, it needs to initialize a gate line signal of each gate line to a low voltage (VGL) so as to initialize all the pixel rows to a non-scanning state, which thus cause that the current of a power supply voltage terminal providing a low voltage becomes very large in a moment; on the other hand, when the liquid crystal is shut down, for the reasons of eliminating shut-down image sticking and protecting the liquid crystal display and so on, it requires to put a gate line signal of each gate line at a high voltage (VGH), such that all the pixel rows are in a scanned state so as to realize quick discharging of all the pixels. At this time, it would result in that the current of the power supply voltage terminal providing a high voltage becomes very large in a moment.
[0004] Since the liquid crystal display causes the output current of the power supply voltage terminal that provides the low voltage (VGL) or the high voltage (VGH) to become very large when being started up or shut down, it then results in that a load of a power supply chip that provides the low voltage (VGL) or the high voltage (VGH) becomes very large in a moment, and also makes that the input current received by a power supply input terminal of the power supply chip from an external power supply becomes large in a moment, which is easy to cause the power supply chip damaged, a connection wire between a power supply input terminal of a power supply chip on the liquid crystal display panel and an external power supply burned out, and a fuse wire on the liquid crystal display panel damaged.
[0005] Therefore, a gate drive device which is capable of reducing current impact when the liquid crystal display is started up or shut down is needed.
SUMMARY
[0006] In order to solve the above technical problem, there is provided a gate drive device, which reduces the current impact when a liquid crystal display is started up or shut down by dividing all gate lines of the liquid crystal display into a plurality of groups, staggering the initialization operation of each group of gate lines for a period of time when the liquid crystal display is started up, and staggering discharging operation of each group of gate lines for a period of time when the liquid crystal display is shut down.
[0007] According to one aspect of the present disclosure, there is provided a gate drive device of a pixel array, the pixel array comprising N gate lines, the gate drive device comprising: a plurality of gate drivers, in which the N gate lines are divided into a plurality of groups, each of which comprises a plurality of gate lines, the plurality of gate drivers and the plurality of groups are in one-to-one correspondence, and each gate driver is used for generating gate drive signals for a plurality of gate lines in the group corresponding to the gate driver, where N is an integer greater than or equal to 4; a driver control module, configured to generate multiple driver control signals, the multiple driver control signals and the plurality of gate drivers are in one-to-one correspondence, and state switches of any two driver control signals in the multiple driver control signals differs at least a first time, wherein the plurality of gate drivers switch from a first state to a second state sequentially under control of the multiple driver control signals, and each of the gate drivers generates gate drive signals with an identical phase for a plurality of gate lines in its corresponding group in the second state.
[0008] According to an embodiment of the present disclosure, the first state is a normal operation state, and the second state is a shut-down transient state. In the first state, at any moment, only one gate drive signal of the plurality of gate drive signals generated by one gate driver of the plurality of gate drivers for the plurality of gate lines in a group corresponding to the gate driver is in a valid drive level while remaining gate drive signals are in an invalid drive level, and gate drive signals generated by remaining gate drivers in the plurality of gate drivers are in an invalid drive level; when one gate driver of the gate drivers switches from the first state to the second state, the gate driver simultaneously generates gate drive signals being in a valid drive level for a plurality of gate lines in the group corresponding to the gate driver.
[0009] According to the embodiment of the present disclosure, the first state is a shut-down state, and each of the gate drivers does not output a gate drive signal in the first state; the second state is a start-up transient state, and when one gate driver of the gate drivers switches from the first state to the second state, the gate driver simultaneously generates gate drive signals being in an invalid drive level for a plurality of gate lines in the group corresponding to the gate driver.
[0010] According to an embodiment of the present disclosure, the driver control module comprises: a plurality of control signal generating modules, each of which comprises: a control voltage generating module configured to generate a control voltage; and an output module, whose first input terminal receivers the control voltage generated by the control voltage generating module, second input terminal receives a reference voltage, and output terminal is taken as an output terminal of the control signal generating module, and configured to generate one driver control signal based on the control voltage and the reference voltage, the driver control signal is a first level when the control voltage and the reference voltage satisfy a first relationship, while the driver control signal is a second level when the control voltage and the reference voltage do not satisfy the first relationship.
[0011] According to an embodiment of the present disclosure, the driver control module comprises: a first control signal generating module, and a plurality of delay units; the first control signal generating module is configured to a first driver control signal, and comprises: a control voltage generating module configured to generate a control voltage; and an output module, whose first input terminal receives the control voltage generated by the control voltage generating module, second input terminal receives a reference voltage, and output terminal is taken as an output terminal of the first control signal generating module, configured to generate the first driver control signal based on the control voltage and the reference voltage, wherein the first driver control signal is the first level when the control voltage and the reference voltage satisfy the first relationship, while the first driver control signal is the second level when the control voltage and the reference voltage do not satisfy the first relationship; the plurality of delay units are configured to generate driver control signals other than the first driver control signal in the multiple driver control signals.
[0012] According to another aspect of the present disclosure, there is provided a drive method of the gate drive device as described above, comprising: generating, by a driver control module, multiple driver control signals sequentially, the multiple driver control signals and a plurality of gate drivers are in one-to-one correspondence, and state switching of any two driver control signals of the multiple driver control signals having a difference of at least a first time; and switching, by the plurality of gate drivers, from a first state to a second state sequentially under control of the multiple driver control signals respectively, and generating, by each of the gate drivers, gate drive signals with an identical phase for the plurality of gate lines in the group corresponding to the gate driver under a second state.
[0013] According to an embodiment of the present disclosure, reference voltages of respective control signal generating modules in the plurality of control signal generating modules are the same with each other, and an output module of each of the plurality of control signal generating modules is made to generate sequentially the multiple driver control signals corresponding one-to-one with the plurality of gate drivers by controlling control voltages of respective control signal generating modules in the plurality of control signal generating modules.
[0014] According to an embodiment of the present disclosure, the control voltages of respective control signal generating modules in the plurality of control signal generating modules are the same with each other, and the output module of respective control signal generating modules in the plurality of control signal generating modules are made to generate sequentially the multiple driver control signals corresponding one-to-one with the plurality of gate drivers by controlling the reference voltages of respective control signal generating modules in the plurality of control signal generating modules.
[0015] According to the embodiment of the present disclosure, the output modules of respective control signal generating modules in the plurality of control signal generating module are made to generate sequentially the plurality of controller control signals corresponding one-to-one with the plurality of gate drivers by controlling the reference voltages and the control voltages of respective control signal generating modules in the plurality of control signal generating modules.
[0016] According to an embodiments of the present disclosure, generating multiple driver control signals by the driver control module comprises: generating a first driver control signal; and delaying a j-th driver control signal at least a first time to obtain a (j+1)-th driver control signal, where j=1, . . . , n-1, n is a number of gate drivers in the gate drive device.
[0017] According to another aspect of the present disclosure, there is provided a display panel, comprising a pixel array, a source drive device, and a gate drive device according to embodiments of the present disclosure.
[0018] On one hand, by adopting the gate drive device according to the embodiments of the present disclosure, and by utilizing multiple control signals having a time delay between each other to control a plurality of gate drivers, the turn-on time of respective gate drivers can be made staggered when it is started up, such that impact current generated when the respective gate drivers are turned on are staggered from each other and not overlapped when it is started up, which reduces total impact currents (total impact currents of the power supply voltage terminal that provides the low voltage) when it is started up. On the other hand, by adopting the gate drive device according to the embodiments of the present disclosure, the turn-off time of respective gate drivers can be made staggered when it is shut down, such that impact current generated when the respective gate drivers are turned off are staggered from each other and not overlapped when it is shut down, which reduces total impact currents (total impact currents of the power supply voltage terminal that provides the high voltage) when it is shut down.
[0019] Other characteristics and advantages of the present disclosure will be described in the subsequent specification, and would be obvious partly from the specification, or would be understood through implementation of the present disclosure. Purposes and other advantages of the present disclosure can be realized and obtained through structures specifically indicated in the specification, Claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above and other purposes, characteristics and advantages of the present disclosure will become more evident by describing in detail the embodiments of the present disclosure in combination with figures. Drawings are used to provide further understanding of the embodiments of the present disclosure, form a part of the specification, are used to explain the present disclosure together with the embodiments of the present disclosure, and do not form a limitation to the present disclosure. In the figures, same reference marks represent generally same means or steps.
[0021] FIG. 1A shows a schematic diagram of a gate driver being controlled by a driver control signal when a present thin film transistor liquid crystal display is started up or shut down;
[0022] FIG. 1B shows a circuit diagram of a driver control signal generating module;
[0023] FIG. 2 shows a schematic block diagram of a gate drive device of an pixel array according to an embodiment of the present disclosure;
[0024] FIG. 3 shows a schematic block diagram of a driver control module according to a first embodiment of the present disclosure;
[0025] FIG. 4 shows a schematic block diagram of a control signal generating module according to a first embodiment of the present disclosure;
[0026] FIG. 5A shows a first schematic circuit diagram of a control signal generating module according to a first embodiment of the present d disclosure;
[0027] FIG. 5B shows a second schematic circuit diagram of a control signal generating module according to a first embodiment of the present disclosure;
[0028] FIG. 6 shows a schematic circuit diagram of a driver control module according to a first embodiment of the present disclosure;
[0029] FIG. 7 shows one schematic specific implementation of a driver control module according to a first embodiment of the present disclosure;
[0030] FIG. 8 shows another schematic specific implementation of a driver control module according to a first embodiment of the present disclosure;
[0031] FIG. 9 shows a variation situation of a voltage of a first power supply voltage terminal in a process from start-up to shut-down of a liquid crystal display;
[0032] FIG. 10 shows a schematic block diagram of a driver control module according to a second embodiment of the present disclosure;
[0033] FIG. 11 shows a schematic circuit diagram of a driver control module according to a second embodiment of the present disclosure; and
[0034] FIG. 12 shows a display panel according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0035] In order to make purposes, technical solutions and advantages of embodiments of the present disclosure more evident, exemplary embodiments of the present disclosure will be described in detail by referring to accompanying drawings. Obviously, the exemplary embodiments described below are just a part of embodiments of the present disclosure, but not all the embodiments of the present disclosure. All the other embodiments obtained by those skilled in the art without any inventive work shall fall into the protection scope of the present disclosure.
[0036] Herein, it should be noted that in the figures, the same reference numerals are basically given to components having the same or similar structures and functions, and their repeated description will be omitted.
[0037] As shown in FIG. 1A , when a present thin film transistor liquid crystal display (TFT-LCD) is started up or shut down, a gate driver GOA is controlled by a driver control signal XON. When the display is started up, the signal XON jumps from low level to high level, and all output terminals G 1 , G 2 , . . . , G(N- 1 ) , and GN of the gate driver are pulled down to a low voltage VGL, when the display is shut down, the signal XON jumps from high level to low level, and all the output terminals G 1 , G 2 , . . . , G(N-l), and GN of the gate driver are pulled up to a high voltage VGH. Generally, the high voltage VGH is a positive voltage, and the low voltage VGL is a negative voltage.
[0038] As shown in FIG. 1B , it shows a driver control signal XON generating module. The XON generating module comprises a comparator P and a switch transistor M. An inverting input terminal (“-”) of the comparator P is connected to a connecting point O between voltage dividing resistors R 1 and R 2 , a non-inverting input terminal (“+”) thereof is connected to a reference voltage terminal REF, and an output terminal thereof is connected to a gate of the switch transistor M; a drain of the switch transistor M is connected to a high voltage terminal VHH via a pull-up resistor R 3 , and a source thereof is connected to a low voltage terminal VSS. For example, the high voltage terminal VHH can provide a high voltage of 3.3V, and the low voltage terminal VSS can be a ground and can provide a low voltage of 0V. For example, the reference voltage provided by the reference voltage terminal REF is higher than 0V and lower than a dividing voltage generated at the connecting point O when a power supply voltage VDD/VIN is applied to the voltage dividing resistors R 1 and R 2 .
[0039] When the liquid crystal display is started up, the power supply voltage VDD/VIN is applied to the voltage dividing resistors R 1 and R 2 , and a voltage of the non-inverting input terminal of the comparator P in the XON generating module becomes lower than a voltage of the inverting input terminal thereof. Therefore, the output terminal of the comparator P outputs the low level, the switch transistor M in the XON generating module is switched off, and at this time the XON signal raises from low level to high level. On the other hand, when the liquid crystal display is shut down, since the power supply voltage VDD/VIN is not applied to the voltage dividing resistors R 1 and R 2 , the voltage of the non-inverting input terminal of the comparator P in the XON generating module would become higher than the voltage of the inverting input terminal. Therefore, the output terminal of the comparator P outputs high level, the switch transistor M in the XON generating module is switched on, and the XON signal is pulled down from high level to low level.
[0040] As shown in FIG. 2 , it shows a schematic block diagram of a gate drive device 200 of a pixel array according to an embodiment of the present disclosure. According to the embodiment of the present disclosure, the gate drive device 200 comprises a plurality of gate drivers 221 , 222 , . . . , 22 ( n - 1 ), 22 n and a driver control module 210 .
[0041] The pixel array comprises N gate lines which are divided into a plurality of groups, for example, n groups, each of which comprises a plurality of gate lines, where n is an integer greater than or equal to 2 , and N is an integer greater than or equal to 4.
[0042] The plurality of gate drivers and the plurality of groups are in one-to-one correspondence, i.e., a first gate driver 221 corresponding to a first group of gate lines, a second gate driver 222 corresponding to a second group of gate lines, and so forth, a (n- 1 )-th gate driver 22 ( n - 1 ) corresponding to a (n- 1 )-th group of gate lines, and a n-th gate driver 22 n corresponding to a n-th group of gate lines. Each gate driver 22 i is used to generate a gate drive signal for a plurality of gate lines in its corresponding i-th group, where i=1, . . . , n. Optionally, each group of gate lines can comprise gate lines with a same number. For example, each group of gate lines comprises M gate lines.
[0043] The driver control module 210 is configured to generate multiple driver control signals XON 1 , XON 2 , . . . , XON(n- 1 ), XONn, and the multiple driver control signals XON 1 , XON 2 , . . . , XON(n- 1 ), XONn and the plurality of gate drivers 221 , 222 , . . . , 22 ( n - 1 ), 22 n are in one-to-one correspondence. State switching of any two driver control signals of the multiple driver control signals XON 1 , XON 2 , . . . , XON(n- 1 ), XONn differs at least a first time. The state switching of the driver control signal can comprise at least one of: the driver control signal switches from the high level to the low level, the driver control signal switches from the low level to the high level, and the first time can be for example duration of current impact generated for each gate driver.
[0044] Under control of the multiple driver control signals XON 1 , XON 2 , . . . , XON(n- 1 ), and XONn, the plurality of gate drivers 221 , 222 , . . . , 22 ( n - 1 ), 22 n switch from the first state to the second state sequentially, and each gate driver 22 i generates a gate drive signal with the same phase for a plurality of gate lines in an i-th group corresponding to the gate driver 22 i under the second state.
[0045] According to the embodiment of the present disclosure, in the process of start-up of the display, the first state is a shut-down state, and the second state is a start-up transient state. Under the first state, each gate driver does not output a gate driving signal. Under control of a driver control signal XONi corresponding to the i-th gate driver 22 i in the plurality of gate drivers, when being switched from the first state (shut-down state) to the second state (start-up transient state), the i-th gate driver 22 i generates a gate drive signal of an invalid drive level for the plurality of gate lines in its corresponding i-th group.
[0046] According to the embodiment of the present disclosure, in the process of shut-down of the display, the first state is a normal operation state, and the second state is a shut-down transient state. In the first state, at any moment, only one gate drive signal of the plurality of gate drive signals generated by one gate driver of the plurality of gate drivers for the plurality of gate lines in a group corresponding to the gate driver is in a valid drive level, while the remaining gate drive signals are in the inactive drive level, and gate drive signals generated by the remaining gate drivers in the plurality of gate drivers are all in the inactive drive level. Under control the driver control signal XONi corresponding to the i-th gate driver 22 i in the gate drivers, when being switched from the first state (normal operation state) to the second state (shut-down transient state), the i-th gate driver 22 i generates a gate drive signal of the active drive level for the plurality of gate lines in the i-th group corresponding to the gate driver 22 i.
First Embodiment
[0047] FIG. 3 shows a schematic block diagram of a driver control module according to a first embodiment of the present disclosure.
[0048] As shown in FIG. 3 , the driver control module 210 comprises a plurality of control signal generating modules 211 , 212 , . . . , 21 ( n - 1 ), 21 n. The plurality of control signal generating modules 211 , 212 , . . . , 21 ( n - 1 ), 21 n and the plurality of gate drivers 221 , 222 , . . . , 22 ( n - 1 ), 22 n are in one-to-one correspondence. Each control signal generating module 21 i generates a driver control signal XONi for the i-th gate driver 22 i corresponding to the control signal generating module 21 i. For example, a first control signal generating module 211 is corresponding to the first gate driver 221 , and generates the driver control signal XON 1 for the first gate driver 221 ; a second control signal generating module 212 is corresponding to the second gate driver 222 , and generates the driver control signal XON 2 for the second gate driver 222 ; and so on and so forth; a (n- 1 )-th control signal generating module 21 ( n - 1 ) is corresponding to the (n- 1 )-th gate driver 22 ( n - 1 ), and generates the driver control signal XON(n- 1 ) for the (n- 1 )-th gate driver 22 ( n - 1 ); a n-th control signal generating module 21 n is corresponding to the n-th gate driver 22 n, and generates the driver control signal XONn for the n-th gate driver 22 n.
[0049] FIG. 4 shows a schematic block diagram of a control signal generating module according to an embodiment of the present disclosure.
[0050] Each control signal generating module can comprise a control voltage generating module 410 and an output module 420 .
[0051] The control voltage generating module 410 is configured to generate a control voltage applicable to the control signal generating module.
[0052] A first input terminal of the output module 420 receives the control voltage generated by the control voltage generating module 410 , a second input terminal thereof is connected to a reference voltage terminal REF and receives a reference voltage Vref from the reference voltage terminal REF, and an output terminal thereof is taken as an output terminal of the control signal generating module.
[0053] The output module 420 is configured to generate a driver control signal based on the control voltage Vo generated by the control voltage generating module 410 and the reference voltage Vref received from the reference voltage terminal REF. In particular, when the control voltage Vo and the reference voltage Vref satisfy a first relationship, the driver control signal is a first level; and when the control voltage V O and the reference voltage Vref do not satisfy the first relationship, the driver control signal is a second level. For example, when the control voltage V O is higher than the reference voltage Vref, the driver control signal XON is a high level; and when the control voltage V O is not higher than the reference voltage Vref, the driver control signal XON is low level.
[0054] FIG. 5A shows a first schematic circuit diagram of a control signal generating module according to an embodiment of the present disclosure.
[0055] The control voltage generating module 410 comprises a first resistor R 1 and the second resistor R 2 . A first terminal of the first resistor R 1 is connected to a first power supply voltage terminal VDD, a second terminal of the first resistor R 1 is connected to a first terminal of the second resistor R 2 , a second terminal of the second resistor R 2 is connected to a second power supply voltage terminal VGG, and a connecting point O between the second terminal of the first resistor R 1 and the first terminal of the second resistor R 2 is taken as the output terminal of the control voltage generating module 410 .
[0056] The output module 420 comprises a comparator 421 , a switch transistor 422 , and a third resistor R 3 . An inverting input terminal (“-”) of the comparator 421 is taken as the first input terminal of the output module 420 and connected to the output terminal of the control voltage generating module 410 , a non-inverting input terminal (“+”) thereof is taken as the second input terminal of the output module 420 and connected to the reference voltage terminal, and an output terminal thereof is taken as the output terminal of the output module 420 and connected to a gate of the switch transistor 422 . A first electrode of the switch transistor 422 is taken as the output terminal of the output module 420 and is connected to a third power supply voltage terminal VHH via the third resistor R 3 , and a second electrode thereof is connected to a fourth power supply voltage terminal VSS.
[0057] In the circuit diagram as shown in FIG. 5A , the first power supply voltage terminal VDD and the third power supply voltage terminal VHH can be a same power supply voltage terminal and can both provide a voltage of 3.3V; and the second power supply voltage terminal VGG and the fourth power supply voltage terminal VSS can be a same power supply voltage terminal and can be a ground. Additionally, in the circuit diagram as shown in FIG. 5A , the switch transistor 422 is a N channel enhancement switch transistor, a first electrode of the switch transistor 422 is a drain, and a second electrode thereof is a source.
[0058] In the process of start-up of the liquid crystal display, the first power supply voltage VDD of the first power supply voltage terminal VDD is applied to the first resistor R 1 and the second resistor R 2 , and an output voltage at point O can be calculated according to a resistor voltage dividing formula:
[0000] V O =( R 2 /( R 1 +R 2 ))*V DD (1)
[0000] where R 1 is a resistance value of the first resistor R 1 , R 2 is a resistance value of the second resistor R 2 , and VO is an output voltage at point O. When VO rises to be higher than the reference voltage Vref of the reference voltage terminal REF, an output of the comparator 421 switches from high level to low level, the switch transistor 422 changes from turn-on into turn-off, and the XON signal output by the output module 420 jumps from low level to high level.
[0059] On the other hand, in the process of shut-down of the liquid crystal display, the first power supply voltage V DD of the first power supply voltage terminal VDD is not applied to the first resistor R 1 and the second resistor R 2 , and the output voltage VO at the point O is 0V. It is apparent that at this time the output voltage VO at the point O is lower than the reference voltage Vref of the reference voltage terminal REF, the output of the comparator 421 switches from low level to high level, the switch transistor 422 changes from turn-off into turn-on, and the XON signal output by the output module 420 jumps from high level to low level.
[0060] FIG. 5B shows a second schematic circuit diagram of a control signal generating module according to an embodiment of the present disclosure.
[0061] The output module 420 comprises a comparator 521 , a switch transistor 522 and a third resistor R 3 . An inverting input terminal (“-”) of the comparator 521 is connected to the reference voltage terminal REF, a non-inverting input terminal (“+”) thereof is connected to the output terminal of the control voltage generating module 410 , and an output terminal thereof is connected to a gate of the switch transistor 522 . A first electrode of the switch transistor 522 is connected to a third power supply voltage terminal via the third resistor R 3 , and a second electrode thereof is connected to a fourth power supply voltage terminal.
[0062] In the circuit diagram as shown in FIG. 5B , the first power supply voltage terminal VDD and the third power supply voltage terminal VHH can be a same power supply voltage terminal and can provide a voltage of 3.3V; and the second power supply voltage terminal VGG and the fourth power supply voltage terminal VSS can be a same power supply voltage terminal and can be a ground. Additionally, in the circuit diagram as shown in FIG. 5B , the switch transistor 522 is a P channel enhancement switch transistor, a first electrode of the switch transistor 522 is a source, and a second electrode thereof is a drain.
[0063] In the process of start-up of the liquid crystal display, the first power supply voltage V DD of the first power supply voltage terminal VDD is applied to the first resistor R 1 and the second resistor R 2 . When the output voltage VO at point O rises to be higher than the reference voltage Vref of the reference voltage terminal REF, an output of the comparator 521 switches from low level to high level, the switch transistor 522 changes from turn-on into turn-off, and the XON signal output by the output module 420 jumps from low level to high level.
[0064] On the other hand, in the process of shut-down of the liquid crystal display, the first power supply voltage V DD of the first power supply voltage terminal VDD is not applied to the first resistor R 1 and the second resistor R 2 , and the output voltage V O at the point O is 0V. Obviously, the reference voltage Vref of the reference voltage terminal REF is higher than the output voltage VO at the point O at this time, the output of the comparator 521 switches from high level to low level, the switch transistor 522 changes from turn-off into turn-on, and the XON signal output by the output module 420 jumps from high level to low level.
[0065] In FIG. 6 , the schematic circuit diagram of driver control module 210 is shown by taking the control voltage generating module as shown in FIG. 5A as an example and taking the driver control module 210 comprising three control signal generating module as an example.
[0066] A control voltage generating module of the first control signal generating module 211 comprises a resistor R 11 and a resistor R 12 , and an output module thereof comprises a first comparator P 1 , a first switch transistor Ml and a resistor R 13 .
[0067] A control voltage of the second control signal generating module 212 comprises a resistor R 21 and a resistor R 22 , and an output module thereof comprises a second comparator P 2 , a second switch transistor M 2 and a resistor R 23 .
[0068] A control voltage generating module of the third control signal generating module 213 comprises a resistor R 31 and a resistor R 32 , and an output module thereof comprises third comparator P 3 , a third switch transistor M 3 and a resistor R 33 .
[0069] In the process of start-up of the liquid crystal display, the first power supply voltage of the first power supply voltage terminal is applied to the resistors R 11 and R 12 of the first control signal generating module 211 , to the resistors R 21 and R 22 of the second control signal generating module 212 , and to the resistors R 31 and R 32 of the third control signal generating module 213 . At this time, an output voltage of an output terminal O 1 in the first control signal generating module 211 , an output voltage of an output terminal O 2 in the second control signal generating module 212 , and an output voltage of an output terminal O 3 in the third control signal generating module 213 can be represented as:
[0000] V O1 =( R 12 /( R 11 +R 12 ))*V DD
[0000] V O2 =( R 22 /( R 21 +R 22 ))*V DD
[0000] V O3 =( R 32 /( R 31 +R 32 ))*V DD
[0070] When V O1 rises to be higher than a first reference voltage Vref 1 of a first reference voltage terminal REF 1 , the XOR 1 signal output by the first control signal generating module jumps from low level to high level; when V O2 rises to be higher than a second reference voltage Vref 2 of a second reference voltage terminal REF 2 , the XOR 2 signal output by the second control signal generating module 212 jumps from low level to high level; and when V O3 rises to be higher than a third reference voltage Vref 3 of a third reference voltage terminal REF 3 , the XOR 3 signal output by the third control signal generating module 213 jumps from low level to high level.
[0071] On the other hand, in the process of shut-down of the liquid crystal display, the first power supply voltage V DD of the first power supply voltage terminal VDD is not applied to the resistors R 11 and R 12 of the first control signal generating module 211 , to the resistors R 1 and R 22 of the second control signal generating module 212 , and to the resistors R 31 and R 32 of the third control signal generating module 213 . When V O1 decreases to be lower than a first reference voltage Vref 1 of the first reference voltage terminal REF 1 , the XOR 1 signal output by the first control signal generating module 211 jumps from high level to low level; when O2 decreases to be lower than a second reference voltage Vref 2 of a second reference voltage terminal REF 2 , the XOR 2 signal output by the second control signal generating module 212 jumps from high level to low level; and when V O3 decreases to be lower than a third reference voltage Vref 3 of a third reference voltage terminal REF 3 , the XOR 3 signal output by the third control signal generating module 213 jumps from high level to low level.
[0072] By appropriately setting a time of V O1 rising to be higher than Vref 1 , a time of V O2 rising to be higher than Vref 2 , and a time of V O3 rising to be higher than Vref 3 in the process of start-up, a time that the XOR 1 signal generated by the first control signal generating module 211 jumps from low level to high level, a time that the XOR 2 signal generated by the second control signal generating module 212 jumps from low level to high level, and a time that the XOR 3 signal generated by the first control signal generating module 213 jumps from low level to high level can be controlled. In other words, a time that the first gate driver 221 corresponding to the first control signal generating module 211 outputs a gate drive signal of low level at all output terminals thereof, a time that the second gate driver 222 corresponding to the second control signal generating module 212 outputs a gate drive signal of low level at all output terminals thereof, and a time that the third gate driver 223 corresponding to the third control signal generating module 213 outputs a gate drive signal of low level at all output terminals thereof can be controlled.
[0073] For example, reference voltages of respective control signal generating modules in the plurality of control signal generating modules can be the same with each other, and control voltages of the respective control signal generating modules in the plurality of control signal generating modules can be different from each other. By adjusting amplitudes of the control voltages of the respective control signal generating module, state switching time of driver control signals generated by the respective control signal generating modules can be adjusted, so that start-up time and shut-down time of the respective gate drivers can be adjusted correspondingly.
[0074] For example, reference voltages of respective control signal generating modules in the plurality of control signal generating modules can be different from each other, and control voltages of the respective control signal generating modules in the plurality of control signal generating modules can be the same with each other. By adjusting amplitudes of the reference voltages of the respective control signal generating module, state switching time of driver control signals generated by the respective control signal generating modules can be adjusted, so that start-up time and shut-down time of the respective gate drivers can be adjusted correspondingly.
[0075] For another example, reference voltages of respective control signal generating modules in the plurality of control signal generating modules can be different from each other, and control voltages of the respective control signal generating modules in the plurality of control signal generating modules can also be different each other. By adjusting amplitudes of the control voltages and the reference voltages of the respective control signal generating module, state switching time of driver control signals generated by the respective control signal generating modules can be adjusted, so that start-up time and shut-down time of the respective gate drivers can be adjusted correspondingly.
[0076] FIG. 7 shows a schematic specific implementation of a driver control module 210 according to an embodiment of the present disclosure. In this specific implementation, reference voltages of respective control signal generating modules in the plurality of control signal generating modules are the same with each other, and control voltages of the respective control signal generating modules in the plurality of control signal generating modules are different from each other. By controlling control voltages of the respective control signal generating modules in the plurality of control signal generating modules, it makes that output modules of the respective control signal generating modules in the plurality of control signal generating modules generate the multiple driver control signals corresponding to the plurality of gate drivers one-to-one sequentially.
[0077] In FIG. 7 , a resistance ratio of the resistor R 11 and the resistor R 12 in the first control signal generating module 211 is a first resistance ratio, a resistance ratio of the resistor R 21 and the resistor R 22 in the second control signal generating module 212 is a second resistance ratio, and a resistance ratio of the resistor R 31 and the resistor R 32 in the third control signal generating module 213 is a third resistance ratio, and the first resistance ratio is lower than the second resistance ratio, the second resistance ratio is lower than the third resistance ratio. In addition, the first reference voltage terminal of the first control signal generating module 211 , the second reference voltage terminal o the second control signal generating module 212 , and the third reference voltage terminal of the third control signal generating module 213 provide a same reference voltage and can be a same reference voltage terminal.
[0078] By appropriately setting the first resistance ratio, the second resistance ratio, and the third resistance ratio, the time that the output signal of the first comparator P 1 switches from high level to low level, the time that the output signal of the second comparator P 2 switches from high level to low level, and the time that the output signal of the third comparator P 3 switches from high level to low level can be controlled. That is, the time that the XOR 1 signal generated by the first control signal generating module 211 jumps from low level to high level, the time that the XOR 2 signal generated by the second control signal generating module 212 jumps from low level to high level, and the time that the XOR 3 signal generated by the third control signal generating module 213 jumps from low level to high level can be controlled.
[0079] FIG. 9 shows a variation situation of the first power supply voltage V DD of the first power voltage terminal VDD in a process from start-up to shut-down of a liquid crystal display. In FIG. 9 , in order to describe the embodiment of the present disclosure more clearly, the variation period of time of the first power supply voltage V DD of the first power voltage terminal VDD is enlarged.
[0080] As shown in FIG. 9 , in the process of start-up of the liquid crystal display, a voltage rising slope exists in the process of the first power supply voltage V DD rising from a zero voltage to a predetermined high voltage (for example, 3.3V), and the voltage rising time can be approximate to a level of millisecond, for example, hundreds of microseconds, several milliseconds, dozens of milliseconds, or even hundreds of milliseconds. Likewise, in the process of shut-down of the liquid crystal display, a voltage decreasing slope exists in the process of the first power supply voltage V DD decreasing from a predetermined high voltage to a zero voltage, and also the voltage decreasing time can be approximate to a level of millisecond, for example, hundreds of microseconds, several milliseconds, dozens of milliseconds, or even hundreds of milliseconds.
[0081] Returning to FIG. 7 , the reference voltage is for example 1.25V, the first resistance ratio is for example 0.36, the second resistance ratio is for example 0.68, and the third resistance ratio is for example 1. Therefore, the output voltage of the output terminal O 1 of the first control signal generating module 211 , the output voltage of the output terminal O 2 of the second control signal generating module 212 , and the output voltage of the output terminal O 3 of the third control signal generating module 213 can be represented as:
[0000] V O1 =(1/(0.36+1))*V DD =(1/1.36)*V DD
[0000] V O2 =(1/(0.68+1))*V DD =(1/1.68)*V DD
[0000] V O3 =(1/(1+1))*V DD =(1/2)*V DD
[0082] Therefore, for a same V DD rising curve, V O1 reaches Vref at the earliest time, then V O2 reaches Vref, and finally V O3 reaches Vref. A time that V O2 reaches Vref lags a first lagging time than a time that V O1 reaches Vref, a time that V O3 reaches Vref lags a second lagging time than a time that V 2 reaches Vref, and the first lagging time and the second lagging time can be several microseconds to several milliseconds. Correspondingly, the time that the XOR 2 signal output by the second control signal generating module 212 jumps from low level to high level lags the first lagging time than the time that the XOR 1 signal output by the first control signal generating module 211 jumps from low level to high level, and the time that the XOR 3 signal output by the third control signal generating module 213 jumps from low level to high level lags the second lagging time than the time that the XOR 2 signal output by the second control signal generating module 212 jumps from low level to high level.
[0083] Finally, the time that the second gate driver 222 outputs a gate drive signal of low level at all output terminals thereof lags the first lagging time than the time that the first gate driver 221 outputs the gate drive signal of low level at all output terminals thereof, and the time that the third gate driver 223 outputs a gate drive signal of low level at all output terminals thereof lags the second lagging time than the time that the second gate driver 222 outputs the gate drive signal of low level at all output terminals thereof.
[0084] Thus, in the process of start-up of the liquid crystal display, the start-up times of different gate drivers are staggered, that is, the times at which different gate drivers output gate drive signals of low level at all output terminals thereof are staggered, such that the times at which different gate drivers generate current impact are staggered, which avoids the phenomenon that different gate drivers generate current impact at the same time and the current impacts generated by the respective gate drivers at the same time are overlapped to generate large current impact which results in damage of power supply chip, burn-out of power supply leads, and burn-out of fuse wires.
[0085] In the process of shut-down of the liquid crystal display, for a same V DD decreasing curve, V O3 decreases from V DD to Vref at the earliest time, then V O2 decreases from V DD to Vref, and finally V O1 decreases from V DD to Vref. The time that V O2 decreases from V DD to Vref lags a third lagging time than the time that V O3 decreases from V DD to Vref, the time that V O1 decreases from V DD to Vref lags a fourth lagging time than the time that V O2 decreases from V DD to Vref, and the third lagging time and the fourth lagging time can be several microseconds to several milliseconds. Correspondingly, the time that the XOR 2 signal output by the second control signal generating module 212 jumps from high level to low level lags the third lagging time than the time that the XOR 3 signal output by the third control signal generating module 213 jumps from high level to low level, and the time that the XOR 1 signal output by the first control signal generating module 211 jumps from high level to low level lags the fourth lagging time than the time that the XOR 2 signal output by the second control signal generating module 212 jumps from high level to low level.
[0086] Finally, the time that the second gate driver 222 outputs a gate drive signal of high level at all output terminals thereof lags the third lagging time than the time that the third gate driver 223 outputs the gate drive signal of high level at all output terminals of the third gate driver 223 , and the time that the first gate driver 221 outputs a gate drive signal of high level at all output terminals thereof lags the fourth lagging time than the time that the second gate driver 222 outputs the gate drive signal of high level at all output terminals thereof.
[0087] Thus, in the process of shut-down of the liquid crystal display, the shut-down times of different gate drivers are staggered, that is, the times at which different gate drivers output gate drive signals of high level at all output terminals thereof are staggered, such that the times at which different gate drivers generate current impact at a high level output terminal are staggered, which avoids the phenomenon that different gate drivers generate current impact at the same time and the current impacts generated by the respective gate drivers at the same time are overlapped to generate large current impact which results in damage of power supply chip, burn-out of power supply leads, and burn-out of fuse wires.
[0088] FIG. 8 shows another schematic specific implementation of a driver control module 210 according to an embodiment of the present disclosure. In this specific implementation, reference voltages of respective control signal generating modules in the plurality of control signal generating modules are different from each other, and control voltages of the respective control signal generating modules in the plurality of control signal generating modules are the same with each other. By controlling the reference voltages of the respective control signal generating modules in the plurality of control signal generating modules, it makes that output modules of the respective control signal generating modules in the plurality of control signal generating modules generate sequentially the multiple driver control signals corresponding one-to-one with the plurality of gate drivers.
[0089] In FIG. 8 , the first resistance ratio of the resistor R 11 and the resistor R 12 in the first control signal generating module 211 , the second resistance ratio of the resistor R 21 and the resistor R 22 in the second control signal generating module 212 , and the third resistance ratio of the resistor R 31 and the resistor R 32 in the third control signal generating module 213 are the same. In addition, the first reference voltage terminal in the first control signal generating module 211 provides a first reference voltage, the second reference voltage terminal in the second control signal generating module 212 provides a second reference voltage, and the third reference voltage in the third control signal generating module 213 provides a third reference voltage, and the first reference voltage is lower than the second reference voltage, the second reference voltage is lower than the third reference voltage.
[0090] For example, the first resistance ratio, the second resistance ration, and the third resistance ratio can be 1, and the first reference voltage, the second reference voltage and the third reference voltage can be 1.2V, 1.4V, and 1.6V sequentially.
[0091] In the process of start-up of the liquid crystal display, rising speeds of V O1 , V O2 , and V O3 are the same. Therefore, V O1 reaches Vref 1 (1.2V) at the earliest time, then V O2 reaches Vref 2 (1.4V), and finally V O3 reaches Vref 3 (1.6V). the time that V O2 reaches Vref 2 lags a fifth lagging time than a time that V O1 reaches Vref 1 , the time that V O3 reaches Vref 3 lags a sixth lagging time than a time that V O2 reaches Vref 2 , and the fifth lagging time and the sixth lagging time can be several microseconds to several milliseconds. Correspondingly, the time that the XOR 2 signal output by the second control signal generating module 212 jumps from low level to high level lags the fifth lagging time than the time that the XOR 1 signal output by the first control signal generating module 211 jumps from low level to high level, and the time that the XOR 3 signal output by the third control signal generating module 213 jumps from low level to high level lags the sixth lagging time than the time that the XOR 2 signal output by the second control signal generating module 212 jumps from low level to high level.
[0092] Finally, the time that the second gate driver 222 outputs a gate drive signal of low level at all output terminals thereof lags the fifth lagging time than the time that the first gate driver 221 outputs the gate drive signal of low level at all output terminals thereof, and the time that the third gate driver 223 outputs a gate drive signal of low level at all output terminals thereof lags the sixth lagging time than the time that the second gate driver 222 outputs the gate drive signal of low level at all output terminals thereof.
[0093] Thus, in the process of start-up of the liquid crystal display, the start-up times of different gate drivers are staggered, that is, the times at which different gate drivers output gate drive signals of low level at all output terminals thereof are staggered, such that the times that different gate drivers generate current impact are staggered, which avoids the phenomenon that different gate drivers generate current impact at the same time and the current impacts generated by the respective gate drivers at the same time are overlapped to generate large current impact which results in damage of power supply chip, burn-out of power supply leads, and burn-out of fuse wires.
[0094] In the process of shut-down of the liquid crystal display, decreasing speeds of V O1 , V O2 , and V O3 are the same. V O3 decreases from V DD to Vref 3 at the earliest time, then V O2 decreases from V DD to Vref 2 , and finally V O1 decreases from V DD to Vref 1 . The time that V O2 decreases from V DD to Vref lags a seventh lagging time than the time that V O3 decreases from V DD to Vref 3 , the time that V O1 decreases from V DD to Vref 1 lags an eighth lagging time than the time that V O2 decreases from V DD to Vref 2 , and the seventh lagging time and the eighth lagging time can be several microseconds to several milliseconds. Correspondingly, the time that the XOR 2 signal output by the second control signal generating module 212 jumps from high level to low level lags the seventh lagging time than the time that the XOR 3 signal output by the third control signal generating module 213 jumps from high level to low level, and the time that the XOR 1 signal output by the first control signal generating module 211 jumps from high level to low level lags the eighth lagging time than the time that the XOR 2 signal output by the second control signal generating module 212 jumps from high level to low level.
[0095] Finally, the time that the second gate driver 222 outputs a gate drive signal of high level at all output terminals thereof lags the seventh lagging time than the time that the third gate driver 223 outputs the gate drive signal of high level at all output terminals thereof, and the time that the first gate driver 221 outputs a gate drive signal of high level at all output terminals thereof lags the eighth lagging time than the time that the second gate driver 222 outputs the gate drive signal of high level at all output terminals thereof.
[0096] Thus, in the process of shut-down of the liquid crystal display, the shut-down times of different gate drivers are staggered, that is, the time that different gate drivers output gate drive signals of high level at all output terminals thereof are staggered, such that the times that different gate drivers generate current impact at a high level output terminal are staggered, which avoids the phenomenon that different gate drivers generate current impact at the same time and the current impacts generated by the respective gate drivers at the same time are overlapped to generate large current impact which results in damage of power supply chip, burn-out of power supply leads, and burn-out of fuse wires.
Second Embodiment
[0097] FIG. 10 shows a schematic block diagram of a driver control module according to a second embodiment of the present disclosure.
[0098] The driver control module 210 comprises a first control signal generating module 2101 , and a plurality of delay units 2102 , . . . , 210 ( n - 1 ), 210 n. The first control signal generating module 2101 is corresponding to a first gate driver 221 , and generates a first driver control signal for the first gate driver 221 . A first delay unit 2102 in the plurality of delay units is corresponding to a second gate driver 222 , and generates a second driver control signal for the second gate driver 222 , a second delay unit 2103 is corresponding to a third gate driver 223 , and generates a third driver control signal for the third gate driver 223 , and so on and so forth, a (n- 2 )-th delay unit 210 ( n - 1 ) is corresponding to a (n- 1 )-th gate driver 22 ( n - 1 ), and generates a (n- 1 )-th driver control signal for the (n- 1 )-th gate driver 22 ( n - 1 ), and a (n- 1 )-th delay unit 210 n is corresponding to a n-th gate driver 22 n, and generates a n-th driver control signal for the n-th gate driver 22 n.
[0099] The first control signal generating module 2101 is configured to generate a first driver control signal, which is used to control the first gate driver 221 . The first control signal generating module 2101 can adopt the circuit structure as shown in FIG. 5A or FIG. 5B , and thus no further description is given herein.
[0100] The plurality of delay units are configured to generate driver control signals other than the first driver control signal in the multiple driver control signals based on the first driver control signal.
[0101] In specific implementation, the first delay unit can receive a first driver control signal XON 1 output by the first control signal generating module 2101 , delay the received first driver control signal XON 1 a predetermined time to obtain a second driver control signal XON 2 , and output the second driver control signal XON 2 , and so on and so forth. The (n- 2 )-th delay unit can receive a (n- 2 )-th driver control signal XON(n- 2 ) output by a (n- 3 )-th delay unit, delay the received (n- 2 )-th driver control signal XON(n- 1 ) a predetermined time to obtain a (n- 1 )-th driver control signal XON(n- 1 ), and output (n- 1 )-th driver control signal XON(n- 1 ); the (n- 1 )-th delay unit can receive a (n- 1 )-th driver control signal XON(n- 1 ) output by a (n- 2 )-th delay unit, delay the received (n- 1 )-th driver control signal XON(n- 1 ) a predetermined time to obtain a n-th driver control signal XONn, and output n-th driver control signal XONn.
[0102] In the specific implementation, each delay unit can comprise a fourth resistor and a capacitor. More specifically, in the first delay unit, a first terminal of the fourth resistor is connected to an output terminal of the first control signal generating module, and a second terminal of the fourth resistor is connected to a first capacitor of the capacitor, a second terminal of the capacitor is connected to a fourth power supply voltage terminal VSS, and a connecting point of the second terminal of the fourth resistor and the first terminal of the capacitor is taken as the output terminal of the delay unit to output a second driver control signal. In each of remaining delay units other than the first delay unit, the first terminal of the fourth resistor is connected to an output terminal of a previous delay unit, the second terminal of the fourth resistor is connected to the first terminal of the capacitor, the second terminal of the capacitor is connected to the fourth power supply voltage terminal VSS, and the connecting point of the second terminal of the fourth resistor and the first terminal of the capacitor is taken as the output terminal of the delay unit to output a driver control signal delayed relative to a driver control signal output by the previous delay unit.
[0103] Alternatively, in another specific implementation, the first delay unit can receive the first driver control signal XON 1 output by the first control signal generating module, delay the received first driver control signal XON 1 a first time to obtain the second driver control signal XON 2 , and output the second driver control signal XON 2 . Likewise, the (n- 2 )-th delay unit can receive the first driver control signal XON 1 output by the first control signal generating module, delay the received first driver control signal XON 1 a (n- 2 )-th time to obtain the (n- 1 )-th driver control signal XON(n- 1 ), and output the (n- 1 )-th driver control signal XON(n- 1 ); the (n- 1 )-th delay unit can receive the first driver control signal XON 1 output by the first control signal generating module, delay the received first driver control signal XON 1 the (n- 1 )-th time to obtain the n-th driver control signal XONn, and output the n-th driver control signal XONn. The (n- 1 )-th time can be (n- 1 ) times of the first time, the n-th time can be n times of the first time.
[0104] In FIG. 11 , the schematic circuit diagram of the driver control module 210 is shown by taking the control voltage generating module as shown in FIG. 5A as an example and by taking the driver control module 210 comprising two delay units as an example.
[0105] The control voltage generating module of the first control signal generating module 2101 comprises a first resistor R 111 and a second resistor R 112 , and the output module thereof comprises a comparator P, a switch transistor M, and a third resistor R 113 .
[0106] The first delay unit comprises a resistor R 114 and a capacitor C 1 . A first terminal of the resistor R 114 is connected to the output terminal of the first control signal generating module to receive the first driver control signal XON 1 generated by the first control signal generating module, a second terminal of the resistor R 114 is connected to a first terminal of the capacitor C 11 , a second terminal of the capacitor C 1 is connected to the fourth power supply voltage terminal VSS, and a connecting point between the second terminal of the resistor R 114 and the first terminal of the capacitor C 1 is taken as an output terminal of the first delay unit to output the second driver control signal XON 2 .
[0107] The second delay unit comprises a resistor R 115 and a capacitor C 2 . A first terminal of the resistor R 115 is connected to the output terminal of the first delay unit to receive the second driver control signal XON 2 , a second terminal of the resistor R 115 is connected to a first terminal of the capacitor C 2 , and a second terminal of the capacitor C 2 is connected to the fourth power supply voltage terminal VSS, and a connecting point between the second terminal of the resistor R 115 and the first terminal of the capacitor C 2 is taken as an output terminal of the second delay unit to output the third driver control signal XON 3 .
[0108] In the process of start-up of the liquid crystal display, the first power supply voltage V DD of the first power supply voltage terminal VDD is applied to the resistors R 111 and R 112 of the first control signal generating module. When the voltage V O at point O rises to be higher than the reference voltage Vref of the reference voltage terminal REF, output of the comparator P jumps from high level to low level, the switch transistor M changes from turn-on into turn-off, and the first driver control signal XON 1 changes from low level into high level; after the XON 1 changes from low level into high level, the capacitor C 1 is charged by a RC circuit constituted of the resistor R 114 and the capacitor C 1 , and the second driver control signal XON 2 reaches a high level after the first delay time; after the XON 2 reaches the high level, the capacitor C 2 is charged by a RC circuit constituted of the resistor R 115 and the capacitor C 2 , and the third drive control signal XON 3 reaches high level after the second delay time.
[0109] The first delay time is decided by a resistance value R 114 of the resistor R 114 and a capacitance value C 1 of the capacitor C 1 , and the second delay time is decided by a resistance value R 115 of the resistor R 115 and a capacitance value C 2 of the capacitor C 2 . Specifically, the first delay time t XON2 =R 114 *C 1 , and the second delay time t XON3 =R 115 *C 2 .
[0110] In other words, a start-up time of the second gate driver 222 lags the first delay time t XON2 than a start-up time of the first gate driver 221 , and a start-up time of the third gate driver 223 lags the second delay time t XON3 than a start-up time of the second gate driver 222 . The first delay time t XON2 and the second delay time t XON3 are greater than a duration of current impact generated when each gate driver simultaneously outputs gate drive signals of low level at the output terminal of the gate driver. The first delay time t XON2 and the second delay time t XON3 can be several microseconds to several milliseconds. Optionally, the first delay time t XON2 is equal to the second delay time t XON3 .
[0111] In the process of shut-down of the liquid crystal display, the first power supply voltage V DD of the first power supply voltage terminal VDD is not applied to the resistors R 111 and R 112 of the first control signal generating module again. When the voltage V O at point O decreases to be lower than the reference voltage Vref of the reference voltage terminal REF, the output of the comparator P jumps from low level to high level, the switch transistor M changes from turn-off into turn-on, and the first driver control signal XON 1 changes from high level into low level; after the XON 1 changes from high level into low level, the capacitor C 1 is discharged by the RC circuit constituted of the resistor R 114 and the capacitor C 1 , and the second driver control signal XON 2 changes into the low level after the third delay time; after the XON 2 changes into the low level, the capacitor C 2 is discharged by a RC circuit constituted of the resistor R 115 and the capacitor C 2 , and the second drive control signal XON 3 changes into the low level after the fourth delay time. The third delay time is decided by the resistance value R 114 of the resistor R 114 and the capacitance value C 1 of the capacitor C 1 , and the fourth delay time is decided by the resistance value R 114 of the resistor R 114 , the resistance value R 115 of the resistor R 115 and the capacitance value C 2 of the capacitor C 2 .
[0112] Therefore, the shut-down time of the second gate driver 222 lags the third delay time than the shut-down time of the first gate driver 221 , the shut-down time of the third gate driver 223 lags the fourth delay time than the shut-down time of the second gate driver 222 . The third delay time and the fourth delay time are greater than a duration of current impact generated when each gate driver simultaneously outputs gate drive signals of low level at the output terminal of the gate driver. The third delay time and the fourth delay time can be several microseconds to several milliseconds.
[0113] It shall be understood that in the case that the gate drive device comprises n gate drivers, the gate drive device can comprises (n- 1 ) delay units. A j-th delay unit delays a j-th driver control signal to obtain a (j+1)-th driver control signal, and a j-th driver control signal is used to control a j-th gate driver, where j=1, . . . , n- 1 , and n is an integer greater than or equal to 2.
[0114] FIG. 12 shows a display panel according to an embodiment of the present disclosure, comprising an array, a source drive device, and a gate drive device according to the embodiments of the present disclosure.
[0115] According to the embodiments of the present disclosure, since the duration of the impact current generated when each gate driver is stared up (shut down) is generally several microseconds, the start-up (shut-down) times of respective gate drivers can be staggered efficiently by controlling the first through eighth lagging times to be longer than the duration of the impact current, controlling the first time to be longer than the duration of the impact current, and controlling the first through fourth delay times to be longer than the duration of the impact current.
[0116] According to the embodiments of the present disclosure, by utilizing multiple driver control signals having a time delay between each other to control a plurality of gate drivers, the turn-on time of respective gate drivers can be staggered when it is started up, such that impact currents generated when the respective gate drivers are turned on are staggered from each other and not overlapped when it is started up, which reduces total impact currents (total impact currents of the power supply voltage terminal that provides the low voltage) when it is started up. On the other hand, by adopting the gate drive device according to the embodiments of the present disclosure, the turn-off time of respective gate drivers can be staggered when it is shut down, such that impact currents generated when the respective gate drivers are turned off are staggered from each other and not overlapped when it is shut down, which reduces total impact currents (total impact currents of the power supply voltage terminal that provides the high voltage) when it is shut down, which avoids the phenomenon that different gate drivers generate current impact at the same time and the current impacts generated by the respective gate drivers at the same time are overlapped to generate large current impact which results in damage of power supply chip, burn-out of power supply leads, and burn-out of fuse wires.
[0117] Respective embodiments of the present disclosure are described in detail above. However, those skilled in the art shall understand that various amendments, combination or sub-combination can be made to these embodiments without departing from the principle and sprit of the present disclosure, and these amendments shall fall into the scope of the present disclosure.
[0118] The present application claims the priority of a Chinese patent application No. 201510645169.7 filed on Oct. 8, 2015, with an invention title of “GATE DRIVE DEVICE OF PIXEL ARRAY AND DRIVE METHOD THEREOF”. Herein, the content disclosed by the Chinese patent application is incorporated in full by reference as a part of the present disclosure.
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Disclosed are a gate driving apparatus for a pixel array and a driving method therefor. The pixel array includes N gate lines. The gate driving apparatus includes: a plurality of gate drivers, wherein the N gate lines are divided into a plurality of groups, each group includes a plurality of gate lines, each gate driver corresponds to the plurality of groups on a one-to-one basis, and is used for generating a gate driving signal for the plurality of gate lines in the group corresponding thereto; and a driver control module which is used for generating a plurality of driver control signals corresponding to the plurality of gate drivers on a one-to-one basis, and state switching between any two driver control signals has at least a difference of first time, wherein under control of the driver control signals, the gate drivers are switched from first state to second state in sequence.
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[0001] The priority application Number 2007-207282, upon which this patent application is based, is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to imaging devices equipped with an imaging function, such as electronic cameras e.g. digital cameras, and particularly to imaging devices which control data communication with external recording devices connected thereto.
[0004] 2. Description of Related Art
[0005] When connecting a typical electronic camera and the like to other devices, it is usually connected through a USB (Universal Serial Bus) interface. According to the USB standard, a host which has a host controller polls (queries) a device connected to the host, thereby performing the communication between the host and the device. All the communications are controlled by the host and thus the devices cannot poll the host.
[0006] Generally, when transferring imaging data obtained by an imaging operation of an electronic camera to an external recording device through a USB cable, the electronic camera is connected to a personal computer (PC) which is connected to the external recording device and then the imaging data is transferred to the external device via the PC. Therefore, the PC is the host and the electronic camera and the external recording device are the devices. The PC controls all the communications and transfers the imaging data from the electronic camera to the external recording device. Thus, transferring imaging data taken with an electronic camera to an external recording device always needs the intermediary of PC, which requires vexatiousness of starting PC and the like.
[0007] There has been proposed an imaging device capable of performing data communication with an external device without the intermediary of PC.
[0008] Generally, when a host equipment and a device equipment are connected to each other through a USB interface, the host equipment and the device equipment send a query command and a reply command to each other in conformity with the USB standard to thereby establish the connection therebetween. Also, when the connection between the host equipment and the device equipment is canceled, the host equipment and the device equipment send a query command and a reply command to each other in conformity with the USB standard to thereby cancel the connection therebetween. Thus, in the case where an external recording device as the device equipment is connected to the host equipment, and the connection is established between the both equipments, if the user unplugs a USB connector from one of the equipments in error and thereby physically disconnects the equipments, then the stored data recorded in the external recording device can be destroyed.
[0009] However, in the conventional imaging device capable of performing data communication with an external device without the intermediary of PC, no countermeasures are taken to prevent stored data recorded in the device equipment from being destroyed by physical disconnection in the connection established status as described above.
SUMMARY OF THE INVENTION
[0010] Hence an object of the present invention is to provide an imaging device which can prevent problems such as destruction of stored data recorded in an external recording device connected thereto.
[0011] An imaging device according to the present invention comprises:
[0012] an interface for connecting an external recording device;
[0013] a control circuit for controlling data communication with the external recording device connected to the interface; and
[0014] an information storage for storing data management information of the data recorded in the external recording device.
[0015] The control circuit comprises:
[0016] a connection establisher for realizing a connection established status by performing a connecting process to establish connection with the external recording device;
[0017] an information acquirer for acquiring the data management information from the external recording device to store the data management information in the information storage in the connection established status;
[0018] an information supplier for supplying the data management information stored in the information storage to the external recording device in the connection established status;
[0019] an electric power saving mode setter for setting the device main body to an electric power saving mode in which operation of part of the device main body stops; and
[0020] a connection canceller for canceling the connection established status before or at the time of setting the device main body to the electric power saving mode after making the information supplier execute the data management information supply operation or after completion of the data management information supply operation by the information supplier.
[0021] In particular, the connection canceller cancels the connection established status after making the information supplier execute the data management information supply operation if it has not executed, or after completion of the data management information supply operation if it is in execution.
[0022] In the imaging device according to the present invention, before or at the time of setting the device main body to the electric power saving mode, after the latest data management information is surely supplied, the connection established status is canceled. Therefore, while the device main body is in the electric power saving mode, even if the user unplugs the cable mistaking the electric power saving mode for the power source OFF status, the stored data recorded in the external recording device will not be destroyed.
[0023] More particularly, the control circuit has an electric power saving mode canceller for canceling the electric power saving mode, and the connection establisher executes the connecting process when the electric power saving mode is canceled by the electric power saving mode canceller.
[0024] According to the particular structure described above, when the electric power saving mode is canceled, the device main body automatically returns to the connection established status. Thus, no operation for returning the device main body to the connection established status is required.
[0025] As described above, according to the imaging device of the present invention, when an external recording device is connected to the imaging device, problems such as destruction of stored data recorded in the external recording device can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an outline view showing an imaging device of the present invention with a hard disk device and a TV monitor connected thereto;
[0027] FIG. 2 is a block diagram illustrating the structure of the imaging device;
[0028] FIG. 3 is a block diagram illustrating the structure of the hard disk device;
[0029] FIG. 4 is a flow chart showing the procedure performed in an electronic camera which constitutes the imaging device with the power source set to ON;
[0030] FIG. 5 is a flow chart showing the practical procedure in the host mode process by the electronic camera; and
[0031] FIG. 6 is a flow chart showing the procedure performed in the connection established status in the electronic camera; and
[0032] FIG. 7 is a flow chart showing the practical procedure performed in the hard disk device.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0033] In this embodiment, as an example of the imaging device, an imaging device including an electronic camera and a cradle is described.
[0034] FIG. 1 shows an imaging device according to the present invention provided with a hard disk device 80 and a TV monitor 60 connected thereto. The imaging device according to the present invention includes an electronic camera 10 and a cradle 50 to put the electronic camera thereon as shown in the figure, and the electronic camera 10 transmits and receives data to and from the hard disk device 80 and the TV monitor 60 via the cradle 50 .
[0035] FIG. 2 is a block diagram illustrating the structure of the electronic camera 10 and the cradle 50 . Details of the electronic camera 10 and the cradle 50 are described below with reference to FIG. 2 . The electronic camera 10 is provided with an imaging lens 2 , a CMOS image sensor 4 , an imaging processing section 6 , a CPU 8 , a USB terminal 10 a, an image output terminal 10 b, a power source switch terminal 10 c, an operation section 12 , a remote control light receiving section 14 , an SDRAM 16 , a compression/decompression processing section 18 , a USB host controller 20 , a USB device controller 22 , a USB interface 24 , a card control section 26 , an external memory card 28 , a video encoder 30 and a monitor 32 .
[0036] The imaging lens 2 provides an image of an optical image of an object on an imaging area of the CMOS image sensor 4 which is an imaging element. An analog imaging signal outputted from the CMOS image sensor 4 is subjected to imaging processing by the imaging processing section 6 and then converted into a Y signal which is a luminance signal and U and V signals which are color difference signals. The location of the imaging lens 2 in the direction of light axis is adjusted based on the output signals of the CMOS image sensor 4 .
[0037] The CPU 8 is connected to the imaging processing section 6 , the operation section 12 , the remote control light receiving section 14 , the SDRAM 16 , the compression/decompression processing section 18 , the USB host controller 20 , the USB device controller 22 , the card control section 26 , the video encoder 30 and the power source switch terminal 10 c. The CPU 8 controls the imaging processing section 6 , the SDRAM 16 , the compression/decompression processing section 18 , the USB host controller 20 , the USB device controller 22 , the card control section 26 and the video encoder 30 in accordance with a program stored in an internal memory which is not shown in the figures. A timer 8 a built in the CPU 8 counts time and sets a time-out flag which shows a time out status when counting a predetermined time is completed.
[0038] An imaging process and a reproduction process by the CPU 8 are executed in response to a predetermined operation to the operation section 12 . For more particular description of the imaging process, the CPU 8 compresses a taken movie and picture by means of the compression/decompression processing section 18 , and then records the compressed movie data and picture data as a movie file and picture file in the external memory card 28 . For more particular description of the reproduction process, the CPU 8 decompresses the movie file and picture file recorded in the external memory card 28 by means of the compression/decompression processing section 18 , and then converts them into analog image signals such as NTSC signals by means of the video encoder 30 to output them to the monitor 32 or the image output terminal 10 b. The SDRAM 16 is used for temporary storage of data in such an imaging process and a reproduction process.
[0039] The USB terminal 10 a, the image output terminal 10 b and the power source switch terminal 10 c that are provided in the electronic camera 10 can be connected to the cradle 50 . The USB terminal 10 a is connected to the USB interface 24 in the electronic camera 10 , while the USB host controller 20 and the USB device controller 22 are connected to the USB interface 24 in parallel.
[0040] The cradle 50 is provided with a USB terminal 50 a, an image input terminal 50 b and a power source switch terminal 50 c to be connected to the USB terminal 10 a, the image output terminal 10 b and the power source switch terminal 10 c respectively, and a host connector 54 and a device connector 56 are connected to the USB terminal 50 a in parallel. A power source switch 52 and an AV connector 58 are connected to the image input terminal 50 b and the power source switch terminal 50 c respectively.
[0041] The host connector 54 can have an external recording device equipped with a device function such as the hard disk device 80 connected thereto through a USB cable. When the hard disk device 80 is connected to the host connector 54 , the movie file and picture file can be recorded in the hard disk device 80 via the cradle 50 . The device connector 56 can have a personal computer (PC) equipped with a host function connected thereto. The AV connector 58 can have the TV monitor 60 connected thereto. When the TV monitor 60 is connected to the AV connector 58 , the movie file and picture file recorded in the external memory card 28 can be outputted to the TV monitor 60 via the cradle 50 to display the movie and picture. In particular, in the reproduction process described above, the analog image signals outputted from the image output terminal 10 b are supplied to the AV connector 58 to be outputted to the TV monitor 60 .
[0042] Now referring to FIG. 3 , the hard disk device 80 is described below. FIG. 3 is a block diagram illustrating the structure of the hard disk device 80 . The hard disk device 80 is provided with a USB terminal 80 a, a USB interface 82 , a CPU 84 , an HD controller 86 and an HD drive 88 . The USB interface 82 and the HD controller 86 are connected to the CPU 84 , which controls the USB interface 82 and the HD controller 86 in accordance with a program stored in a memory which is not shown in the figure.
[0043] After putting the electronic camera 10 on the cradle 50 connected to the hard disk device 80 with the power source of the camera set to OFF as shown in FIG. 1 , upon operation of the power source switch 52 on the cradle 50 , the power source of the camera is set to ON and then the connection establishing process is executed to establish the connection between the electronic camera 10 and the hard disk device 80 .
[0044] To be specific, when the power source switch 52 is operated, the CPU 8 shown in FIG. 2 detects the operation and sets the power source of the camera to ON. When the power source of the camera main body is set to ON, the CPU 8 detects a voltage applied to the host connector 54 via the USB interface 24 , thereby detecting that the device equipment (the hard disk device 80 ) is connected to the host connector 54 . At the same time, the device equipment (the hard disk device 80 ) detects the voltage via the USB interface 82 , thereby detecting that the electronic camera 10 which is the host equipment is connected thereto.
[0045] And then, the CPU 8 controls the USB host controller 20 and sends a query command to the connected device equipment (the hard disk device 80 ) to inquire what kind of driver the equipment is controlled by. The device equipment (the hard disk device 80 ) sends a reply command to the electronic camera 10 in response to the query command replying that the equipment is controlled by the driver of the hard disk device 80 . Thus the electronic camera 10 recognizes what kind of driver the device equipment (the hard disk device 80 ) is communicable with and establishes connection with the hard disk device 80 . Once the connection is established, all the data communications between the electronic camera 10 and the hard disk device 80 is controlled by the electronic camera 10 . The electronic camera 10 according to this embodiment is provided with the driver of the hard disk device 80 . In this embodiment, the host mode process described above is executed. The establishment of connection between the host equipment and device equipment is in conformity with the USB standard and therefore not described here in detail.
[0046] In data transmitting and receiving process between the electronic camera 10 and the hard disk device 80 between which the connection is established, the CPU 8 of the electronic camera 10 controls the USB host controller 20 and sends a request command to the hard disk device 80 requesting transfer of FAT (File Allocation Tables) information recorded in a hard disk (not shown). The hard disk device 80 receives the request command through the USB interface 82 and the CPU 84 analyzes the request command and then controls the HD controller 86 to read out the FAT information from the hard disk by means of the HD drive 88 , and sends a reply command including the read FAT information to the electronic camera 10 . The FAT information is then stored in the SDRAM 16 , whereby the electronic camera 10 can manage data of the hard disk device 80 .
[0047] Operations of the electronic camera 10 and the hard disk device 80 in recording in the hard disk device 80 via the cradle 50 the movie file and picture file recorded in the external memory card 28 are described below. The CPU 8 of the electronic camera 10 first analyzes the FAT information of the hard disk device 80 stored in the SDRAM 16 . And then after determining how to write data in the hard disk of the hard disk device 80 , the CPU 8 controls the card control section 26 to read out the movie file or picture file from the external memory card 28 . Subsequently the CPU 8 controls the USB host controller 20 to output the movie file or picture file to the USB terminal 10 a from the USB interface 24 and to supply the movie file or picture file from the host connector 54 to the hard disk device 80 via the USB terminal 50 a of the cradle 50 . During this process, a request command and a reply command transmission and reception are conducted in conformity with the USB standard between the electronic camera 10 and the hard disk device 80 . Then, by updating the FAT information stored in the SDRAM 16 and controlling the USB host controller 20 , the updated FAT information is supplied to the hard disk device 80 . The HD drive 88 of the hard disk device 80 shown in FIG. 3 records the supplied movie file or picture file in the hard disk and then writes and records the supplied FAT information over the FAT information previously recorded in the hard disk.
[0048] The electronic camera 10 can output the movie file and picture file recorded in the external memory card 28 to the PC connected to the device connector 56 of the cradle 50 . In such a case, in establishing connection between the host equipment and the device equipment, the PC is the host equipment and the electronic camera is the device equipment. In the electronic camera 10 , when a transfer request of the file recorded in the external memory card 28 from the PC equipped with a host function is received by the USB device controller 22 , the CPU 8 controls the card control section 26 in accordance with the content of the received request, reads out the movie file or picture file recorded in the external memory card 28 , and controls the USB device controller 22 , thereby outputting the movie file or picture file from the USB interface 24 to the USB terminal 10 a. The outputted file is supplied to the PC via the cradle 50 and the device connector 56 . In this embodiment, the device mode process described above is executed.
[0049] When the power source OFF operation of the electronic camera 10 is executed, the CPU 8 controls the USB host controller 20 to execute the connection established status canceling process and then sets the power source of the device main body to OFF. When the connection established status with the hard disk device 80 is canceled, the CPU 8 erases the FAT information of the hard disk device 80 stored in the SDRAM 16 .
[0050] The electronic camera 10 can set an electric power saving mode in which operation of part of the circuits constituting the camera main body stops. In the connection established status between the hard disk device 80 and the electronic camera 10 , when the CPU 8 determines no operation is made to the operation section 12 or no remote controller signal is received by the remote control light receiving section 14 within the predetermined time with which the built-in timer 8 a times out, it executes the process for canceling the connection established status between the hard disk device 80 and the electronic camera 10 and then shifts the camera main body from the usual operation mode to the electric power saving mode.
[0051] The connection canceling process between the hard disk device 80 and the camera is executed before the camera is shifted to the electric power saving mode for the following reasons. When the electronic camera 10 is in the electric power saving mode, the display on the monitor 32 of FIG. 1 is not shown, therefore, it is difficult for the user to find out whether the camera main body is in the electric power saving mode or the power source is set to OFF. Therefore, even though the electronic camera 10 is in the electric power saving mode, it can be mistaken for the power source OFF status and the electronic camera 10 can be removed from the cradle 50 mistakenly by the user. Thus, when connection is established between the electronic camera 10 which is the host equipment and the hard disk device 80 which is the device equipment, forceful cancellation of the connection established status between the equipments can lead failure of operation of supplying the latest FAT information stored in the SDRAM 16 of the electronic camera 10 to the hard disk device 80 or interruption thereof, which can result in destruction of the stored data, for example, the data stored in the hard disk device 80 becoming unreadable.
[0052] The electronic camera 10 according to this embodiment therefore executes the connection canceling process with the hard disk device 80 before the camera main body is shifted to the electric power saving mode. In the connection canceling process, the CPU 8 disconnects the hard disk device 80 after the USB host controller 20 executes a FAT information supply operation if the USB host controller 20 has not supplied the latest FAT information to the hard disk device 80 , or after a FAT information supply operation is completed if the USB host controller 20 is in the process of the FAT information supply operation.
[0053] Now referring to the flowcharts of FIGS. 4 to 6 , an operation of the CPU 8 of the electronic camera 10 in this embodiment is described below.
[0054] FIG. 4 illustrates a procedure performed by the CPU 8 with the power source of the camera main body set to ON. When the power source of the camera main body is set to ON in response to a power source ON operation to the operation section 12 , reception of a power source ON signal by the remote control light receiving section 14 , or an operation to the power source switch 52 with the camera put on the cradle 50 , first, an initial check is performed as to the remaining battery level, remaining capacity of the external memory card 28 and the like in step S 1 . And then, proceeding to step S 3 , the CPU 8 determines whether or not a voltage is applied to the USB host connector 54 or the device connector 56 through the USB interface 24 . When it determines NO in the step S 3 , it further proceeds to step S 5 and performs a process in a usual electronic camera such as imaging and reproduction as described above.
[0055] When it determines YES in the step S 3 , it further proceeds to step S 7 and determines which of the host connector 54 or the device connector 56 the voltage is applied to. When it determines that the voltage is applied to the device connector 56 , it further proceeds to step S 11 and performs the device mode process described above, while it proceeds to step S 9 and performs the host mode process to be described below when it determines that the voltage is applied to the host connector 54 .
[0056] Referring to FIG. 5 , an operation of the CPU 8 in the host mode process is described below. First, in step S 13 , the CPU 8 performs the connection establishing process with the hard disk device 80 . And then proceeding to step S 15 , it resets the timer 8 a in the CPU 8 and then starts the timer. Then proceeding to step S 17 , it determines whether or not there is an operation to the operation section 18 or a receipt of a remote control signal by the remote control light receiving section 14 . When it determines YES in step S 17 , it proceeds to step S 19 and performs the process in response to the operation to the operation section 18 or the received remote control operation signal, followed by proceeding to step S 21 . When it determines NO in step S 17 , it proceeds to step S 21 bypassing step S 19 .
[0057] In step S 21 , it determines whether or not the timer 8 a is in a time out status. When it determines NO, it returns to step S 17 and repeats the processes of steps S 17 to S 21 until it determines YES in step S 21 . Once it determines YES in step S 21 , it proceeds to step S 23 and performs the connection canceling process for canceling the connection established status with the hard disk device 80 , followed by proceeding to step S 25 to shift the camera main body from the usual operation status to the electric power saving mode.
[0058] Subsequently, it proceeds to step S 27 and determines whether or not an operation for canceling the electric power saving mode is performed. To be specific, it determines whether or not there is an operation to the operation section 18 or a receipt of a remote control operation signal by the remote control light receiving section 14 . It repeats the process of step S 27 until it determines that an operation for canceling the electric power saving mode is performed. When it determines YES in step S 27 , it returns to step S 1 of FIG. 4 and then performs the connection establishing process in step S 13 of FIG. 5 . Thereby when the electric power saving mode is canceled, the device main body automatically goes back to the connection established status.
[0059] In the host mode process, when the connection establishing process is performed in step S 13 , a connection canceling process by a power source OFF operation shown in FIG. 6 is performed in parallel. First, it determines whether or not a power source OFF operation is performed in step S 29 . When it determines YES in this step, it proceeds to step S 31 and performs the connection canceling process. Subsequently, proceeding to step S 33 , it sets the power source of the camera main body to OFF and completes the procedure. When a power source OFF operation is performed during the process of steps S 15 to S 27 of FIG. 5 , the connection canceling process is performed preferentially to set the power source of the camera main body to OFF.
[0060] Referring to FIG. 7 now, an operation of the CPU 84 of the hard disk device 80 of this embodiment is described below. First, in step S 35 , it determines whether or not a voltage is applied via the USB interface 82 . When it determines YES in step S 35 , it proceeds to step S 37 and determines whether or not a query command or the like from the electronic camera 10 for the connection establishment between the both devices is received. When it determines YES in step S 37 , it proceeds to step S 39 and performs a process for establishing connection with the electronic camera 10 described above.
[0061] Subsequently, proceeding to step S 41 , it determines whether or not a request command from the electronic camera 10 such as a command to request transferring the FAT information or stored data and a command to request connection canceling is received. When it determines YES in this step, it proceeds to step S 43 and determines whether or not the received request command is a request command for connection canceling. When the received request command is for transfer of the FAT information or stored data and it determines NO in step S 43 , it proceeds to step S 47 and performs a process in response to the request command, followed by returning to the step S 41 . In contrast, when the received request command is for connection canceling and it determines YES in step S 43 , it proceeds to step S 45 and performs the connection canceling process to complete the procedure.
[0062] As described above, in the imaging device according to this embodiment, before the electronic camera 10 shifts to the electric power saving mode, the latest FAT information is surely supplied from the electronic camera 10 to the hard disk device 80 and then the connection established status is canceled. Therefore, even if the user unplugs a USB cable from the cradle 50 or the hard disk device 80 when the electronic camera 10 is set to the electric power saving mode, mistaking it for the power source OFF status, the stored data recorded in the hard disk device 80 will not be destroyed.
[0063] Although the present invention is implemented in an imaging device including the electronic camera 10 and the cradle 50 in the embodiment described above, it is also possible to implement the present invention in an imaging device consisting of only an electronic camera. In an embodiment of the present invention with an imaging device consisting of only an electronic camera, the electronic camera and an external recording device such as a hard disk device are connected to each other through a USB cable.
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An imaging device comprises an interface for connecting an external recording device, a control circuit for controlling data communication with the external recording device connected to the interface, and an information storage. The control circuit comprises a connection establisher for realizing a connection established status with the external recording device, an information supplier for supplying the data management information stored in the information storage to the external recording device, and a connection canceller for canceling the connection established status before or at the time of setting the device main body to the electric power saving mode, after making the information supplier execute the data management information supply operation or after completion of the data management information supply operation by the information supplier.
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FIELD OF THE INVENTION
The present invention relates to a process for preparing a toner which includes silicone-containing organic resin microparticles, and the resulting toner.
BACKGROUND OF THE INVENTION
In electrophotography, a toner to which an electric charge has been given by rubbing with carrier particles is moved onto an electrostatic latent image with the opposite electric charge on a photosensitive member, and the imaged toner is then transferred onto a substrate like paper to realize the image. The substrate is then contacted with a heat roll to fix the image on the substrate. The heat roll is made from a material to which the toner does not adhere, but there is still a problem that a portion of the toner is adhered on the heat roll and will leave a thin image on the next substrate, which is called "off set".
In order to avoid the off set, Japanese Kokai Publication 106073/1989 proposes that silicone-containing polymer microparticles be mixed with a toner mixture. However, it takes a long period of time to form a uniform mixture of the silicone-containing polymer microparticles and the toner mixture. The resulting toner mixture may often cause blocking of toner particles. If carrier particles are also mixed in the toner mixture, the silicone-containing polymer microparticles are adhered onto the carrier particles and adversely affect the charge properties of the carrier particles.
Japanese Kokai Publication 137264/1989 discloses that a toner is prepared by a suspension-polymerization in the presence of a remover polymer, such as silicone oil, mineral oil and the like. In this technique, however, the remover polymer is unstable in a polymerization system and therefore adversely affects the blocking properties of the toner. The amount of the remover polymer introduced has a certain limitation, or is insufficient.
SUMMARY OF THE INVENTION
The present invention provides a toner which substantially excludes the off set and the blocking of the toner, and a process for preparing the toner. The toner is prepared by dispersion-polymerizing a vinyl monomer in the presence of a dispersion polymerization stabilizer, a polymerization initiator and silicone-containing organic resin microparticles in a dispersion medium which dissolves said vinyl monomer, dispersion polymerization stabilizer and polymerization initiator and which does not dissolve said silicone-containing organic resin microparticles and resulting toner particles.
DETAILED DESCRIPTION OF THE INVENTION
The silicone-containing organic resin microparticles can be any organic resin microparticles in which silicone is present. The silicone may exist in the particles in any form, such as absorption, chemical bond and the like. The resin microparticles may be prepared by any method, for example, a method wherein silicone is absorbed in organic resin microparticles, a method wherein a silicone emulsion is employed as a seed and an emulsion polymerization of an acryl monomer is conducted thereon, a method as shown in Japanese Kokai Publications 106614/1986, 81412/1987 and 98609/1989 wherein silicone is grafted with acryl polymer. It is preferred that the silicone has a viscosity of 10 to 10,000 cp, more preferably 50 to 2,000 cp, and includes various types of commercially available silicone oil. When the viscosity is less than 10 cp, it is difficult to incorporate the silicone into toner particles and the silicone present inside the particles is easily moved onto the surface of the particles and deteriorates blocking properties. When the viscosity is more than 10,000 cp, the silicone is hardly moved onto the surface and therefore can not inhibit the off set. The silicone may be branched, but if it is highly branched the silicone becomes difficult to move onto the surface and has poor inhibition of off set. The silicone may be modified with an acid, an amine and the like. The weight ratio of the silicone/organic resin microparticles is preferably within the range of 80/20 to 5/95.
The silicone-containing organic resin microparticles preferably have an average particle size of 0.03 to 1.0 micron, more preferably 0.07 to 0.5 micron. When the average particle size is less than 0.03 micron, it is difficult to produce such small microparticles and to incorporate small microparticles into the toner particles. When the average particle size is more than 1.0 micron, the silicone is not uniformly present in the toner particles and is easily moved onto the surface, which causes poor blocking properties. It is required that the silicone-containing organic resin microparticles be insoluble in the dispersion medium. The silicone-containing resin microparticles are present in an amount of 0.1 to 30.0% by weight (i.e. 0.005 to 24.0% by weight calculated in terms of the silicone) based on an amount of the vinyl monomer. Amounts of less than 0.1% by weight often cause problems of off set and amounts of more than 30.0% by weight provide poor blocking properties.
The vinyl monomer employed in the present invention can be anyone which is used for toner, and preferably includes styrene and other monomers. Examples of the other monomers are alkyl (meth)acrylates, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and the like; hydroxyl group-containing monomers, such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, allyl alcohol, methallyl alcohol and the like; carboxyl group-containing monomers, such as (meth)acrylic acid and the like; polymerizable amides, such as (meth)acrylamide and the like; polymerizable nitriles, such as (meth)acrylonitrile and the like; glycidyl (meth)acrylate; polyfunctional monomers, such as divinylbenzene, divinyl ether, ethyleneglycol dimethacrylate, polyethyleneglycol dimethacrylate, neopentylglycol dimethacrylate, trimethylolpropane trimethacrylate, diallyl phthalate and the like.
The polymerization initiator of the present invention can be one which is known to the art, including peroxides, such as benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, t-butylperoxy-2-ethyl hexanoate and the like; azo compounds, such as azobisisobutylonitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobutylate and the like; and a mixture thereof. The amount of the initiator is within the range of 0.1 to 15% by weight, preferably 0.5 to 1% by weight based on the amount of the vinyl monomer.
The dispersion polymerization stabilizer of the present invention can be anyone which is soluble in the dispersion medium, including celluloses, such as hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate butylate, hydroxybutylmethyl cellulose, hydroxypropylmethyl cellulose, propionic cellulose and the like; polyvinyl alcohols, such as polyvinyl acetate, ethylene-vinyl alcohol copolymer, vinyl alcohol-vinyl acetate copolymer and the like; other polymers, such as polyvinyl pyrrolidone, polyacrylic acid, polyvinyl methyl ether, acrylic acid, styrene-acrylic resin and the like; condensed polymers, such as polyester resin, polyethyleneimine and the like; and a mixture thereof. Amphoteric ion-containing resin as described in Japanese Kokai Publications 151727/1981 and 40522/1982 can also be employed in the present invention. In order to narrow the particle size distribution of the toner particles, the stabilizer may contain radical polymerizable groups or chain transfer groups if necessary (see Japanese Kokai Publication 304002/1988). The dispersion polymerization stabilizer may preferably be present in an amount of 3 to 30% by weight based on the total amount of the vinyl monomer, but amounts outside the range can also be used.
The dispersion polymerization in the present invention can be carried out in a dispersion medium which dissolves the vinyl monomer, the dispersion polymerization stabilizer and the polymerization initiator and which does not dissolve the silicone-containing organic resin microparticles and the resulting toner particles. Examples of the dispersion mediums are alcohols, such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, n-hexanol, cyclohexanol, ethylene glycol, propylene glycol and dipropylene glycol; ether alcohols, such as ethyleneglycol monomethyl ether, ethyleneglycol monoethyl ether, ethyleneglycol monobutyl ether, propyleneglycol monomethyl ether, propyleneglycol monoethyl ether, propyleneglycol monobutyl ether, diethyleneglycol monomethyl ether, diethyleneglycol monoethyl ether, diethyleneglycol monobutyl ether, dipropyleneglycol monomethyl ether and dipropyleneglycol monoethyl ether; a mixture thereof; and the like. Water may be added to the above medium up to 50 parts by weight based on 100 parts by weight of the medium.
In the dispersion polymerization, a coloring agent and other additives (e.g. magnetic powder (magnetite), polyethylene wax, polypropylene wax, silicon compounds) may be added. Typical examples of the coloring agents are inorganic pigments, organic pigments and dyes, including carbon black, Cinquacia red, disazo yellow, Carmine 6B direct yellow, direct blue and the like. The coloring agent and the additives are formulated into the reaction system in an amount of 3 to 50% by weight. It is preferred that the surface of the inorganic pigments is subjected to polymer grafting to stably disperse the pigments. The method of the polymer grafting is known to the art, for example in Japanese Kokai Publication 23133/1980.
The dispersion polymerization may be carried out at a temperature of 5° to 150° C. under a nitrogen atmosphere for 5 to 25 hours, but those conditions do not limit the present invention.
According to the present invention, since the dispersion polymerization is carried out in the presence of the silicone-containing organic resin microparticles, the silicone is included in the toner in the form of microparticles and the amount of the silicone in the toner can be widely varied. The silicone is uniformly contained in the toner and effectively prevents blocking. The toner of the present invention is very useful for electrophotography and effectively prevents off set without other removers.
EXAMPLES
The present invention is illustrated by the following Examples which, however, are not to be construed as limiting the present invention to their details.
PRODUCTION EXAMPLE 1
Synthesis of silicone-containing acryl microparticles (I)
A two liter flask was charged with 800 parts by weight of deionized water and 8 parts by weight of dodecylbenzenesulfonic acid, and heated to 85° C. with stirring. Next, 400 parts by weight of octamethylcylclotetrasiloxane, 8 parts by weight of Perex SS-L (sodium alkyl diphenyl ether disulfonate surfactant available from Kao Corp.) and 400 parts by weight of deionized water were mixed to form an emulsion which was added dropwise to the flask for 2 hours. After reacting 5 hours, it was cooled and neutralized with a 2N sodium carbonate solution.
An emulsion was prepared by mixing, using a homogenizer, 304 parts by weight of the resulting silicone seed emulsion, 105 parts by weight of styrene, 45 parts by weight of n-butyl methacrylate, 10 parts by weight of ethyleneglycol dimethacrylate, 40 parts by weight of 2-hydroxyethyl methacrylate and 414 parts by weight of deionized water, and then charged in a two liter flask, which was heated to 80° C. A solution of one part by weight of potassium persulfate and 150 parts by weight of deionized water was added dropwise for one hour and reacted for 3 hours and cooled. The emulsion had a nonvolatile content of 26.0% and contained silicone-containing acryl microparticles (I) having an average particle size of 80 nm which was determined by a light scattering method.
PRODUCTION EXAMPLE 2
Synthesis of silicone-containing acryl microparticles (II)
An emulsion was prepared by mixing, using a homogenizer, 809 parts by weight of the silicone seed emulsion of Production Example 1, 33.6 parts by weight of styrene, 14.4 parts by weight of n-butyl methacrylate, 3 parts by weight of ethyleneglycol dimethacrylate, 9 parts by weight of 2-hydroxyethyl methacrylate, 91 parts by weight of deionized water and 0.3 parts by weight of potassium persulfate, and then charged in a two liter flask, which was heated to 80° C. with stirring. After reacting for 4 hours, the resulting emulsion had a nonvolatile content of 26.3% and contained silicone-containing acryl microparticles (II) having an average particle size of 110 nm which was determined by the light scattering method.
PRODUCTION EXAMPLE 3
Synthesis of acryl microparticles
A one liter flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen introducing tube was charged with 280 parts by weight of deionized water, to which 35 parts by weight of styrene, 18 parts by weight of methyl methacrylate, 18 parts by weight of n-butyl methacrylate, 16 parts by weight of ethyleneglycol dimethacrylate and 3 parts by weight of sodium dodecylbenzenefulfonate were added dropwise at 80° C. for 2 hours. One part by weight of 4,4'-azobis-4-cyanovaleric acid was neutralized with an alkali and dissolved in 20 parts by weight of deionized water, which was added to the flask simultaneously with the monomer mixture to conduct an emulsion polymerization.
The reaction product had a nonvolatile content of 25.0% and had an average particle size of 260 nm which was determined by the light scattering method. It was then dried to obtain acryl microparticles.
PRODUCTION EXAMPLE 4
Preparation of carbon black paste
A pigment paste was prepared by grinding for 3 hours in an SG mil 100 parts by weight of carbon black, 600 parts by weight of styrene, 200 parts by weight of n-butyl methacrylate, 20 parts by weight of a carbon grinding resin having an amine equivalent of 1 mmol/g and an average molecular weight 12,000 (available from Nippon Paint Co., Ltd.) and 1,000 parts by weight of glass beads and then removing the glass beads.
EXAMPLE 1
A one liter flask equipped with a stirrer, a thermometer, a temperature controlling bar and a condenser was charged with 45 parts by weight of the emulsion of the silicone-containing acryl microparticles (I) of Production Example 1, 320 parts by weight of n-propyl alcohol, 47 parts by weight of deionized water, 15 parts by weight of a partially saponified polyvinyl acetate and 90 parts by weight of the carbon black paste of Production Example 4, and heated to 85° C. To the contents, a mixture of 4 parts by weight of lauroyl peroxide, 4 parts by weight of 1,1'-azobis(cyclohexane-1-carbonitrile) and 20 parts by weight of styrene was added and reacted at 85° C. for 18 hours.
The resulting mixture was centrifuged and the sediment was rinsed with methanol and dried to form a toner having an average particle size of 7 microns which contained silicone.
EXAMPLE 2
A silicone-containing toner having an average particle size of 8.2 microns was prepared as generally described in Example 1, with the exception that the amount of the silicone-containing acryl microparticles of Production Example 1 was changed to 67.5 parts by weight and the amount of deionized water was changed to 30 parts by weight.
EXAMPLE 3
A silicone-containing toner having an average particle size of 5.7 microns was prepared as generally described in Example 1, with the exception that the silicone-containing acryl microparticles of Production Example 1 was changed to that of Production Example 2.
EXAMPLE 4
A silicone-containing toner having an average particle size of 6.8 microns was prepared as generally described in Example 1, with the exception that the silicon-containing acryl microparticles of Production Example 1 was changed to 30 parts by weight of that of Production Example 2 and the amount of deionized water was changed to 57.9 parts by weight.
EXAMPLE 5
One hundred parts by weight of the acryl microparticles obtained in Production Example 3 was mixed with 30 parts by weight of a silicone having a viscosity of 100 cp (available from Shin-Etsu Chemical Co., Ltd. as KF-96) to absorb the silicone into the microparticles.
A pigment paste was prepared by grinding for 1 hour in an SG mil 130 parts by weight of the above obtained silicone-containing microparticles, 100 parts by weight of carbon black, 100 parts by weight of styrene, 200 parts by weight of n-butyl methacrylate, 30 parts by weight of a carbon grinding resin having an amine equivalent of 1 mmol/g and an average molecular weight 12,000 (available from Nippon Paint Co., Ltd.) and 1,000 parts by weight of glass beads and then removing the glass beads.
A silicone-containing toner having an average particle size of 7.3 microns was prepared as generally described in Example 1, with the exception that 100 parts by weight of the above obtained silicone-containing acryl microparticles was employed instead of the carbon black paste of Production Example 4.
EXPERIMENT 1
Spherical ferites having an average particle size of 70 micrometers were covered with styrene-methyl methacrylate copolymer to obtain a carrier. A developer was prepared by mixing 100 parts by weight of the carrier and 2.5 parts by weight of each one of the toners of Examples 1 to 5. An off set test was conducted using a copy machine (available from Sharp Corporation as SF-8800 and the results are shown in Table 1.
For comparison, a ground toner which contained 3% by weight of silicone was employed and the same test was conducted.
TABLE 1______________________________________ Off set.sup.1 Blocking properties.sup.2______________________________________Examples1 Good Very good2 Very good Very good3 Very good Good4 Very good Good5 Good GoodControl Good Poor______________________________________ .sup.1 Very good shows no off set and Very bad shows that a copy paper wa never removed. Good and poor are somewhere therebetween. .sup.2 Ten grams of a toner was stored at 40° C. for 3 days in a 5 ml sample bottle and then the toner was taken out. Very good shows no hea blocking and very poor shows that the toner was never taken out from the bottle even when the bottle was turned over and the bottom was tapped by fingers. Good and poor shows somewhere therebetween.
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The present invention provides a toner which substantially excludes off set and blocking of the toner particles, and a process for preparing the toner. The toner is prepared by dispersion-polymerizing a vinyl monomer in the presence of a dispersion polymerization stabilizer, a polymerization initiator and silicone-containing organic resin microparticles in a dispersion medium which dissolves said vinyl monomer, dispersion polymerization stabilizer and polymerization initiator and which does not dissolve said silicone-containing organic resin microparticles and resulting toner particles.
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Background
[0001] 1. Field of the Invention
[0002] The invention relates to systems and methods for forming flexible conduits that utilize interlocking links that are individually adjustable to allow a user to modify the tension between the links and thereby fine-tune the ability of the conduit to flex to a desired position, but also provide enough rigidity for the conduit to support other system components to which the conduit is connected.
[0003] 2. Related Art
[0004] Various modular conduit systems are known. These conduits are used for purposes such as protecting electrical, hydraulic or other lines that are positioned within the modular conduits. For instance, U.S. Pat. No. 394,695 to Shutz, U.S. Pat. No. 1,822,624 to Hoeftmann, and U.S. Pat. No. 5,986,215 to Watanabe disclose modular conduit systems for protecting cables in potentially harsh environments such as the sea floor. The modular conduits may also be used as structural components in a system, where the conduit provides a flexible means to position and support other components of the system. For example, U.S. Pat. No. 5,197,767 to Kimura discloses an articulable supporting sheath. Modular conduits may also be used to form or connect pipes, as in the examples of U.S. Pat. No. 1,284,099 to Harris and U.S. Pat. No. 4,856,822 to Parker.
[0005] One conventional modular conduit is marketed and sold under the name “Loc-Line”. This product has a series of components or links that are interconnected by ball-and-socket joints (a ball at the end of one component fits into a socket of an adjacent component. The ball pivots within the socket to allow the relative positions of the components to be adjusted. The links can be moved so that the entire conduit is flexed. The friction between the links normally holds the conduit in a desired position. The links can be male-female (ball on one end, socket on the other), male-male (ball on both ends), female-female (sockets on both ends), or male/female on one end and a non-ball-and-socket termination on the other end. The links can be straight, angled, curved, etc. and can be made in various sizes.
[0006] There are several problems with modular conduits such as this. For example, the links are typically connected by pushing the ball of one link into the socket of another link. This makes the links easy to assemble, but it also causes the links to easily become disconnected as well. Additionally, as the links wear, they become looser and move more freely with respect to each other. As a result, the conduit formed by the links is less likely to maintain a desired position. Still further, because the links are intended to be easily repositioned, the conduit formed by the links typically cannot hold much weight.
SUMMARY OF THE INVENTION
[0007] The various embodiments of the invention may solve one or more of these problems by providing means to adjust the tension of each link. In other words, each link can be tightened to increase the friction between links, thereby making the links hold their respective positions better. Alternatively, each link can be loosened to decrease the friction between links, thereby making the links move more freely with respect to each other. The individual links can be individually tightened or loosened so that portions of the conduit are more rigid and support more weight, while other portions are more easily repositioned.
[0008] One embodiment comprises a modular conduit system that includes a plurality of tubular link components which are interconnected to form a continuous conduit. Each adjacent pair of tubular link components has a ball-and-socket joint that enables the pair of tubular link components to be pivoted with respect to each other. The ball-and-socket joint consists of a ball attached to a first one of the pair of adjacent tubular link components and a socket attached to a second one of the pair of adjacent tubular link components, where the ball is positioned within the socket. The amount of friction between the ball and the socket is adjustable, so that the amount of force required to pivot the pair of tubular link components with respect to each other, which is dependent upon the amount of friction between the ball and the socket, is variable.
[0009] In one embodiment, each tubular link component is split into two halves. The opposing halves are secured to each other by means such as screws that can provide an adjustable securing force. The halves of each of the tubular link components may be substantially identical to facilitate manufacturing and to reduce costs. The tubular link components may be designed to leave a gap between the halves to allow them to be drawn toward each other, thereby increasing the amount of friction in the ball-and-socket joint.
[0010] The modular conduit system may include a base component which is connected to a first end of the conduit, as well as a head component which is connected to a second end of the conduit. The conduit is supported by the base component, and the head component is supported by the conduit. The base component may include, for example, a rechargeable battery, while the head component may include a light that is powered by the battery. Electrical and control lines may be coupled between the base component and the head component. These lines may be positioned within the conduit formed by the plurality of tubular link components.
[0011] Another embodiment may comprise a first tubular link for use in a modular conduit. The tubular link has a tubular member with a first, male end and a second, female end. The male end has a spherical outer surface has the same radius of curvature a spherical inner surface of the female end so that a series of the tubular links can be joined together (each having its male end inserted into the female end of an adjacent link) to form a flexible modular conduit. The tubular member is divided longitudinally into two separable halves that are adjustably secured together. The amount of force that is applied by the halves at the female end to a male end of an adjacent tubular link is adjustable to modify the amount of friction between the tubular links and thereby control the flexibility or rigidity of the joint between the tubular links. The separable halves of the tubular link may be substantially identical, and may be secured to each other with screws. When the two halves are secured to each other, a gap may be left between the halves, so that the two halves can be drawn toward each other, to increase the amount of friction between the female end of the tubular link and the male end of the adjacent tubular link.
[0012] Numerous other embodiments are also possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Other objects and advantages of the invention may become apparent upon reading the following detailed description and upon reference to the accompanying drawings.
[0014] FIGS. 1A-1D are a set of diagrams illustrating an exemplary modular conduit link in accordance with one embodiment.
[0015] FIG. 2 is a diagram illustrating a link that has two female ends in accordance with one embodiment.
[0016] FIG. 3 is a diagram illustrating a link that has a first end that is male and a second end that has a threaded connection in accordance with one embodiment.
[0017] FIG. 4 is a diagram illustrating a link that forms an elbow in accordance with one embodiment.
[0018] FIG. 5 is a diagram illustrating an assembled modular conduit having multiple links in accordance with one embodiment.
[0019] FIG. 6 is a diagram illustrating an exemplary tool utilizing a modular conduit in accordance with one embodiment.
[0020] While the invention is subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and the accompanying detailed description. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiment which is described. This disclosure is instead intended to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims. Further, the drawings may not be to scale, and may exaggerate one or more components in order to facilitate an understanding of the various features described herein.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0021] One or more embodiments of the invention are described below. It should be noted that these and any other embodiments described below are exemplary and are intended to be illustrative of the invention rather than limiting.
[0022] In one embodiment, interlocking links are used to form a flexible conduit. Each link has a male end and a female end, where the male end of one link is sized to fit within the female end of another link. The links are individually adjustable to control the friction between them, thereby controlling the amount of force that is required to move the links with respect to each other. A greater amount of friction makes the links more difficult to move, while less friction allows the links to move more freely.
[0023] In one embodiment, the modular conduit can be used as a flexible support for a tool such as a portable lighting unit. In this embodiment, the conduit extends from a base that houses a rechargeable battery to a lighting head that is powered by the battery. Electrical lines from the battery to the lighting head are enclosed within the conduit to protect them. The links that form the conduit may be tightened as needed to ensure that the conduit is sufficiently rigid to support the lighting head on the base, while maintaining a desired amount of flexibility to enable the lighting head to be properly positioned with respect to the base. As the individual links wear and become looser, they can be re-tightened to ensure that the conduit provides the desired support and flexibility.
[0024] The invention therefore provides several advantages. For instance, after the links are assembled to form a conduit, the links can be tightened to prevent the links from being disconnected from each other, which can be a problem in conventional modular conduits. Another advantage is that the links can be tightened to hold more weight, or loosened to make the conduit more easily flexible. Further, the links can be tightened to account for wear. In other words, as the conduit is used and the joints become looser and less capable of supporting a desired weight, the links can be tightened so they become stiffer, so the conduit remains useful for a longer period of time. Yet another advantage is that the links can be independently adjusted. It may be desirable for some portions of the modular conduit to be stiffer while others are more flexible. Individual links of the present modular conduit can be adjusted to achieve the desired characteristics in different parts of the conduit.
[0025] Referring to FIGS. 1A-1D , a set of diagrams illustrating an exemplary modular conduit link is shown. The term “link” may be used herein to refer alternately to the link of the modular conduit and to the component that forms half of the link (specifically as depicted in FIGS. 1A-1D . FIG. 1A shows a perspective view of one of the halves of the link. FIG. 1B shows a top view of the link. FIG. 1C shows an end view of the link. FIG. 1D shows a cross-section of the link.
[0026] The component 100 shown in FIGS. 1A-1D has a first, male end 110 and a second, female end 120 . Each of these ends has a generally spherical shape. The outer diameter of male end 110 has substantially the same radius (R) as the inner diameter of female end 120 , so that the male end will fit within the female and maintain contact over a substantial portion of the respective surfaces (male outer diameter and female inner diameter). Each half-link component 100 has a flat surface 140 that can be positioned against (or nearly against) the corresponding surface of another half-link. When two of half-links 100 are positioned in this manner, they form a link that is generally symmetric about axis 150 .
[0027] A pair of protrusions 130 and 131 extend outward from the female end 120 of component 100 . Each of protrusions 130 and 131 has a hole therethrough to accommodate a screw (or bolt). The screws secure the protrusions of one half-link to the protrusions of the other half-link. A tab 160 on each half-link is provided to fit within a corresponding recess in the other half-link to help align the two. It is noted that the use of two identical half-links to form the modular conduit link may reduce manufacturing costs (as compared to manufacturing two different halves that are not identical).
[0028] As noted above, two half-links 100 are secured to each other to form a link. Multiple links are then assembled to form a conduit. After several of the links are constructed from the half-links, the male end of a first link is inserted into the female end of a second link. It may be helpful to loosen the screws that secure the halves of the second link at its female end, allowing the halves to move apart slightly. After the male end of the first link is inserted into the female end of the second link, the screws may be tightened to draw the halves together, thereby retaining the male end of the first link in the female end of the second link. This process is repeated with as many links as desired to form a conduit.
[0029] Because the ends of each link are spherical, the links can pivot with respect to each other. The screws at the female end of each link can be tightened or loosened to provide the desired amount of friction at the joint between the links. As explained above, the more the screws are tightened, the more friction there is between the links, and the harder it is to move the links at the joint. While this makes the joint more difficult to flex, it enables the joint to support more weight.
[0030] Conventional modular conduits, on the other hand, are typically one-piece links that are snapped together and are not adjustable in this manner. If there is wear between the links of a conventional modular conduit, the joint becomes looser, and the weight that can be supported by the joint is reduced. At some point, the conventional modular conduit may not be able to support the weight for which it was originally designed, and it may simply have to be replaced. The adjustability of the present modular conduit allows it to be adjusted for wear, thereby extending the useful life of the conduit.
[0031] It should be noted that some conventional modular conduits use a two-piece design rather than a one piece design. These conventional two-piece designs, however, do not provide means to adjust the friction at each joint, and consequently do not allow the flexibility and support provided at each joint to be modified.
[0032] In one embodiment, the half-links may be sized so that the flat surfaces ( 140 ) of the two half-links may not quite touch each other when they are assembled into a conduit. This gap between the half-links may facilitate the adjustment of the friction at the joint by allowing the spacing between the halves of the female end to be changed. In other words, if the halves are already touching, the tightening of the screws may not bring the halves closer together and consequently may not increase the friction at the joint. The gap may allow the halves of the female end to better clamp down on the male end of the other link. It should be noted that the desirability of the gap between the half-links may not be necessary in all embodiments.
[0033] While the body of the present modular conduit may be formed primarily be links as described above and shown in FIGS. 1A-1D , it may be desirable to include other types of links in the conduit as well. Several examples of these alternative types of links are shown in FIGS. 2-4 . FIG. 2 shows a link that has two female ends (a female-female link). Each of the female ends is as described above. This link is designed to be coupled to the male end of an adjoining link so that the conduit terminates with a female end rather than a male end. A male-male link may alternatively be used to change the end of the conduit from female to male. A conduit could also be formed using alternating male-male and female-female links.
[0034] FIG. 3 shows a link that has a first end that is male (as described above) and a second end that has a threaded connection. This link may be used, for example, to convert the end of a conduit from a female termination to a threaded termination. The male-threaded link may be used to enable the conduit to be coupled to a system component that accepts the threaded connection. In one embodiment, the threaded end of the link is screwed into a base that supports the conduit, or a head component that is itself supported by the conduit.
[0035] FIG. 4 shows a link that forms an elbow. This link may be useful when it is necessary for the conduit to make a sharper bend than is possible with a joint between male and female ends. The link depicted in FIG. 4 has a 90-degree bend, but alternative links could have angles that are greater than 90 degrees or less than 90 degrees.
[0036] Still other alternative types of links that are not shown in FIGS. 2-4 may also be used.
[0037] Referring to FIG. 5 , an assembled modular conduit having multiple links is shown. As depicted in this figure, conduit 500 has a threaded connector (male-threaded link) coupled to a series of male-female links (e.g., 520 ). The male-female links are coupled to an elbow link 530 , and a female-female link 540 is coupled to the other end of the elbow link. A second threaded connector 550 is coupled to female-female link 540 to terminate the modular conduit. Conduit 500 provides a means to adjustably connect and support components that are coupled to the ends of the conduit. Modular conduit 500 also provides a means to protect electrical and control lines between the components by running these lines through the hollow conduit.
[0038] Referring to FIG. 6 , a diagram illustrating an exemplary tool utilizing the present modular conduit is shown. In this example, the tool is a portable lighting system 600 . Lighting system 600 includes a base 610 , and modular conduit 620 and a light head 630 . Base 610 includes a rechargeable battery and has a flat bottom surface that allows tha base to be placed on a work surface such as the floor. The base may also provide alternative means to position the system, such as a suction cup that may be used to mount the base on a workpiece.
[0039] Conduit 620 is coupled to base 610 by means of a threaded connector 623 similar to link 510 in FIG. 5 . This connector is screwed into a corresponding set of female threads in the top of base 610 . Modular conduit 620 also includes a series of male-female links (e.g., 621 ), a female-female elbow ( 622 ) and a second threaded connector 624 . Second threaded connector 624 screws into a corresponding threaded socket in the back of light head 630 , so that the light head is adjustably supported by conduit 620 , which is in turn supported by base 610 . Electrical lines (wires) connected to the battery in base 610 are run through modular conduit 620 and are connected to light head 630 to provide power for the light. One or more control lines may also be run through the conduit to enable the functions of the light head to be controlled from switches on base 610 .
[0040] The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the claims. As used herein, the terms “comprises,” “comprising,” or any other variations thereof, are intended to be interpreted as non-exclusively including the elements or limitations which follow those terms. Accordingly, a system, method, or other embodiment that comprises a set of elements is not limited to only those elements, and may include other elements not expressly listed or inherent to the claimed embodiment.
[0041] While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention as detailed within the following claims.
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Modular conduit systems in which a plurality of tubular link components are interconnected to form a continuous conduit. Each adjacent pair of tubular link components has a ball-and-socket joint that enables the pair of tubular link components to be pivoted with respect to each other. The ball-and-socket joint consists of a ball attached to a first one of the pair of adjacent tubular link components and a socket attached to a second one of the pair of adjacent tubular link components, where the ball is positioned within the socket. The amount of friction between the ball and the socket is adjustable, so that the amount of force required to pivot the pair of tubular link components with respect to each other, which is dependent upon the amount of friction between the ball and the socket, is variable.
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This is a Divisional patent application of U.S. Ser. No. 08/937,730, filed Sep. 25, 1997, now abandoned, which is a Continuation of U.S. Ser. No. 08/486,649, filled Jun. 7, 1995, now U.S. Pat. No. 5,672,975.
BACKGROUND OF THE INVENTION
The present invention relates to level measurement in industrial processes. More specifically, the present invention relates to measurement of product level height in a storage tank of the type used in industrial applications using a microwave level gauge.
Instrumentation for the measurement of product level (either liquids or solids) in storage vessels is evolving from contact measurement techniques, such as tape and float, to non-contact techniques. One technology that holds considerable promise is based on the use of microwaves. The basic premise involves transmitting microwaves towards the product surface and receiving reflected microwave energy from the surface. The reflected microwaves are analyzed to determine the distance that they have traveled. Knowledge of the distance traveled and storage vessel height allows determination of product level. Since it is known that microwaves travel at the speed of light, the distance that a microwave travels can be determined if the time of travel is known. The time of travel can be determined by measuring the phase of the return wave and knowing the frequency of the microwave that was transmitted. Further, the time of travel can be measured using well-known digital sampling techniques.
One standard in the process control industry is the use of 4-20 mA process control loops. Under this standard, a 4 mA signal represents a zero reading and a 20 mA signal represents a full scale reading. Further, if a transmitter in the field has sufficiently low power requirements, it is possible to power the transmitter using current from the two-wire loop. However, microwave level transmitters in the process control industry have always required a separate power source. The level transmitters were large and their operation required more power than could be delivered using the 4-20 mA industry standard. Thus, typical prior art microwave level transmitters required additional wiring into the field to provide power to the unit. This additional wiring was not only expensive but also was a source of potential failure.
SUMMARY OF THE INVENTION
A level transmitter measures height of product in a tank such as those used in industrial process applications. The level transmitter is coupled to a two-wire process control loop which is used for both transmitting level information provided by the level transmitter and for providing power to the level transmitter. The level transmitter includes a microwave antenna directed into the tank. A low power microwave source sends a microwave signal through the antenna into the tank. A low power microwave receiver receives a reflected microwave signal. Measurement circuitry coupled to the low power microwave source and to the low power microwave receiver initiates transmitting of the microwave signal and determines product height based upon the reflected signal received by the receiver. Output circuitry coupled to the two-wire process control loop transmits information related to product height over the loop. Power supply circuitry coupled to the two-wire process control loop receives power from the loop to power the level transmitter.
In one embodiment, the measurement circuitry includes a first clock coupled to the source for periodically initiating the microwave signal at a first clock rate. A second clock coupled to the receiver periodically gates the received signal at a second clock rate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a microwave level transmitter in accordance with the invention.
FIG. 2 is a block diagram showing electrical circuitry of the level transmitter of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a diagram which shows microwave level transmitter 10 operably coupled to storage tank 12 . Storage tank 12 is the type typically used in process application and contains fluid (product) 14 . As used herein, product can be a liquid, a solid or a combination of both. Level transmitter 10 includes housing 16 and feedhorn 18 . Transmitter 10 is coupled to two-wire loop 20 . Two-wire loop 20 is a 4-20 mA process control loop. In accordance with the invention, transmitter 10 transmits information related to product 14 height over loop 20 . Further, transmitter 10 is completely powered by power received over loop 20 . In some installations, transmitter 10 meets intrinsic safety requirements and is capable of operating in a potentially explosive environment without danger of causing an ignition. For example, housing 16 is tightly sealed to contain any ignition, and circuitry in housing 16 is designed to reduce stored energy, thereby reducing potential ignition.
FIG. 2 is a block diagram of level transmitter 10 coupled to a process control room 30 over two-wire process control loop 20 . Control room 30 is modeled as resistor 32 and voltage source 34 . Transmitter 10 controls the current I flowing through loop 20 in response to height of product 14 in tank 12 .
Electric circuitry carried in housing 16 of transmitter 10 includes voltage regulator 40 , microprocessor 42 , memory 44 , digital-to-analog converter 46 coupled to analog output circuitry 48 , system clock 50 and reset circuitry 52 . Microprocessor 42 is connected to UART 54 which controls digital I/O circuit 56 and is coupled to current loop 20 through DC blocking capacitors 58 . UART 54 can also be a part of microprocessor 42 . Microprocessor 42 is also coupled to display module 60 for providing a display output and to transceiver circuitry 70 .
Transmitter housing 16 includes microwave transceiver circuitry 70 which includes clock- 1 72 and clock- 2 74 . The output of clock- 1 72 is coupled to step generator 76 which provides an input signal to microwave circulator 78 . Microwave circulator 78 is coupled to antenna 18 and provides an input to impulse receiver 80 . Impulse receiver 80 also receives an input from clock- 2 74 and provides an output to analog-to-digital converter 82 .
In operation, transmitter 10 is in communication with control room 30 over loop 20 and receives power over loop 20 . Voltage regulator 40 provides regulated voltage outputs to electronic circuitry in transmitter 10 . Transmitter 10 operates in accordance with instructions stored in memory 44 under the control of microprocessor 42 at a clock rate determined by system clock 50 . A reset and watchdog circuit 52 monitors the supply voltage to the microprocessor and memory. During power on, circuit 52 provides a reset signal to microprocessor 42 once the supply voltage has reached a sufficient level to allow operation of microprocessor 42 . Additionally, microprocessor 42 periodically ides a “kick” signal to watchdog circuit 52 . If these kick pulses are not received by circuit 52 , circuit 52 provides a reset input to microprocessor 42 to thereby restart microprocessor 42 .
Microprocessor 42 receives data from circuitry 70 through analog-to-digital converter 82 to determine product level height. Clock- 1 72 operates at a first clock frequency f 1 and clock- 2 74 operates at a second frequency f 2 . Clock- 1 72 acts as a “start transmit” clock and clock- 2 74 operates as a “gate receiver” clock, and the clocks are slightly offset in frequency. That is, f 2 =f 1 +Δf. This provides a digital sampling technique described in the ISA paper entitled “Smart Transmitter Using Microwave Pulses to Measure The Level Of Liquids And Solids In Process Applications,” by Hugo Lang and Wolfgang Lubcke of Endress and Hauser GmbH and Company, Maulburg, Germany. Product height is calculated by determining which cycle of clock- 2 74 coincides with a received microwave pulse. In one embodiment, clock- 1 72 is set for a frequency of between 1 MHz and 4 MHz, depending upon such condition at the installation as the maximum distance to be measured and current consumption requirements of the circuitry. Clock- 2 74 is synchronized to clock- 1 72 , but varies in frequency by between about 10 Hz and 40 Hz. The difference in frequency (Δf which provides a difference in clock rates) between clocks 72 and 74 determines the update rate of transmitter 10 . It is possible to obtain a higher received signal level by integrating received pulses over several cycles at the expense of reduced update rates.
The signal of clock- 2 74 provides a gating window which sweeps through the incoming signal at a rate determined by Δf. Impulse receiver 80 gates the incoming microwave signal using the f 2 signal from clock- 2 74 . The output of impulse receiver 80 is a series of pulses. These pulses will vary in amplitude dependent upon the noise or spurious reflections contained in the received signal. When the receipt of the microwave echo from the product surface is coincident with the gate pulse from clock- 2 74 , a larger output pulse results, and is converted to a larger value by analog-to-digital converter 82 . Microprocessor 42 calculates distance by determining which cycle of clock- 2 74 provided the largest output pulse from receiver 80 . Microprocessor 42 determines distance by knowing which gate pulse caused the largest output pulses from impulse receiver 80 as determined by analog-to-digital converter 82 . Product height is determined by the equation:
Level−Tank Height−Distance of Pulse Travel Eq. 1
Level
=
Tank
Height
-
R
·
Δ
f
f
1
·
C
2
·
f
1
Eq
.
2
One
Way
Distance
of
Pulse
Travel
=
R
·
Δ
f
f
1
·
C
2
·
f
1
Eq
.
3
where:
f 1 =clock 1 frequency
f 2 =clock 2 frequency
Δf=f 2 −f 1
R=Receive sample pulse which detected return to echo (R=O to f 1 /Δf)
Analog-to-digital converter 82 should have a fairly fast conversion rate, for example 0.5 μs, when the transmit rate (clock 1 ) is 2 MHz since a sample must be taken after every transmit pulse to see if an echo is present, converter 82 should have a sampling rate which must at least equal the frequency of clock- 1 72 . One example of such an analog-to-digital converter is the sigma-delta converter described in co-pending U.S. patent application Ser. No. 08/060,448 entitled SIGMA DELTA CONVERTER FOR VORTEX FLOWMETER. The resolution of analog-to-digital converter 82 is not particularly critical because only the presence or absence of a pulse is significant.
To further improve performance of transmitter 10 , the receive and transmit circuits in circuitry 70 are electrically isolated from each other. This is important so that transmit pulses are not incorrectly detected by the receiver as the echo pulse. The use of microwave circulator 78 permits accurate control of the source impedance and the receive impedance. The microwave circulator provides isolation between transmit and receive circuitry. Further, circulator 78 prevents the transmit pulse from causing the received circuit to ring. One example circulator is a three-port device which only allows signals from the transmit circuit (step generator 76 ) to reach antenna 18 and incoming signals from antenna 18 to reach receive circuitry 80 . Electrical isolation between transmit and receive circuits may be obtained by other techniques known to those skilled in the art. For example, circulator 78 may be removed and a separate transmit and receive antenna implemented. Further, circuit isolation techniques may be employed which provide isolation between transmit and receive circuits along with a delay circuit such that a received pulse was not received until after any “ringing” from the transmit pulse had faded. In another embodiment, microwave antenna 18 is replaced by a probe which extends into tank 12 shown in FIG. 1 . This embodiment may also include a circulator.
Based upon the detection of an echo pulse by microprocessor 42 through analog-to-digital converter 82 , microprocessor 42 determines the height of product 14 in tank 12 . This information can be transmitted digitally over two-wire loop 20 using digital circuit 56 under the control of UART 54 . Alternatively, microprocessor 42 can control the current level (between, for example, 4 and 20 mA) using digital-to-analog converter 46 to control output circuit 48 and thereby transmit information over two-wire loop 20 . In one embodiment, microprocessor 42 can be set to provide a high output (for example 16 mA) on loop 20 if the product level is either above or below a threshold level stored in memory 44 .
In one preferred embodiment, microprocessor 42 comprises a Motorola 68HC11. This is a low power microprocessor which also provides high speed operation. Another suitable microprocessor is the Intel 80C51. Low power memory devices are preferred. In one embodiment, a 24 Kbyte EPROM is used for program memory, 1 Kbyte RAM is used for working memory and a 256 byte EEPROM non-volatile memory is provided. A typical system clock for a microprocessor is between about 2 MHz and 4 MHz. However, a slower clock requires less power but also yields a slower update rate. Typically, power supply 40 provides efficient conversion of power from the control loop into a supply voltage. For example, if the input power supply is 12 volts and the level gauge electronics require 4 mA, the power supply must efficiently convert this 48 mwatts into a usable supply voltage, such as 5 volts.
The invention provides a number of significant advancements over the art. For example, transmitter 10 is completely powered by power received over two-wire current loop 20 . This reduces the amount of wiring required to place transmitter 10 at a remote location. Microprocessor 42 is also capable of receiving commands over two-wire current loop 20 sent from control room 30 . This is according to a digital communications protocol, for example the HART® communication protocol or, preferably, a digital communications protocol having a dc voltage averaging zero.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A level transmitter for use in a process application measures height of a product in a tank. The level transmitter includes a microwave antenna directed into the tank. A low power microwave source sends a microwave signal through the microwave antenna. A low power microwave receiver receives a reflected microwave signal. Measurement circuitry coupled to the source and receiver initiates transmitting of the microwave signal and determines product height based upon the received, reflected signal. Output circuitry coupled to a two-wire process control loop transmits information related to product height over the loop. Power supply circuitry in the level transmitter coupled to the two-wire process control loop receives power from the loop which powers the level transmitter including the microwave source and the microwave receiver.
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RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/395,358, filed 12 May 2010.
BACKGROUND OF THE INVENTION
The present invention relates generally to firearms, but more particularly to systems and methods regarding firearm trigger assemblies.
Generally, consistency and accuracy are understandably important in the art of firearms, especially in the field of competitive marksmanship. Regarding firearm trigger assemblies, inconsistency and inaccuracy may be attributed to at least two factors: friction and foreign particulates.
In the art of firearms, trigger assemblies may generally be coarsely divided into two types: direct-pull and override. Each trigger assembly type includes a sear pin which is adapted to abut a firing pin in the associated firearm. However, the two types of trigger assemblies differ in the way that the sear pin maintains the firing pin in a retracted, pre-firing state. A direct-pull trigger assembly generally includes a sear pin that travels generally in a linear path, which is substantially perpendicular to and intersects the path of travel of the firing pin. The sear pin included in an override trigger assembly, on the other hand, is adapted to rotate away from the firing pin, where such rotation is caused by the force of the firing pin acting on the sear pin. The sear pin may be spring biased towards the firing pin, but when the trigger is pulled, the firing pin force is allowed to overcome the sear pin spring bias force, thus allowing the firing pin to contact the ammunition round placed in the firearm.
As previously mentioned, two factors can contribute to undesirable inaccuracy and inconsistency in firearm trigger assemblies: friction and foreign particulates. Friction is of particular concern in direct-pull trigger assembly configurations. When in a cocked or pre-firing state, the direct-pull sear pin is in direct mechanical, frictional contact with a rear portion of the firing pin. To withdraw the sear pin and allow the firing pin to discharge the ammunition, the surface of the sear pin must be drawn across the surface of the portion of the firing pin, while the portion of the firing pin is biased towards the sear pin by a significant amount of force largely perpendicular to the direction of travel of the sear pin. Such interface creates a point of high frictional contact between the sear pin and the portion of the firing pin. Repeated firing actions begin to wear down both the sear pin and the portion of the firing pin, thereby altering the performance of the trigger assembly over time.
Foreign particulates, such as oil, cleaning solutions, dust and dirt, can also affect accuracy and consistency. In an attempt to shield trigger assemblies from foreign particulates, prior after-market or replacement override trigger assembly designs were provided as closed design, or housed, triggers, some of which include small springs, screws and ball bearings in an effort to provide adequate functionality. The theory of such closed designs is believed to rest on the basis that the moving parts of the trigger assembly should be shielded from dust. However, it has been discovered that, contrary to the conventional wisdom that shielding moving parts from dust should improve functionality, the housing, or closed design, actually impedes functionality over time by allowing foreign particulates to accumulate therein. In turn, the closed design or housed trigger assemblies must be disassembled to be cleaned, such as by removing cover plates. Unfortunately, such disassembly creates the risk that the small springs, screws and ball bearings will be lost or damaged. Additionally, foreign particulates may extend what would otherwise be considered a normal lock time. A lock time is the amount of time that passes from the time the trigger mechanism is actuated until the time the firing pin strikes the primer of the ammunition round. Generally, the shorter the lock time, the better. Normal lock times for, e.g., a bolt action rifle such as the Mauser M98, range from about four to about seven milliseconds, with newer models ranging from 2.5 to about seven milliseconds.
Accordingly, the art of firearm trigger assemblies would be enhanced by systems and methods suited to overcome at least the two mentioned causes of inconsistency and inaccuracy, while maintaining or reducing lock time.
SUMMARY OF THE INVENTION
The present invention provides embodiments of systems and methods related to firearm trigger assemblies, which overcome one or more of the above mentioned drawbacks. In general, trigger assemblies according to the present invention will assist in preventing the accumulation of dust and other particulates within the assembly, and will assist in providing easy cleaning access in the event that any foreign particulates do interfere with operation.
A first embodiment of a trigger assembly according to the present invention provides an override trigger assembly that may be adapted to replace a removed trigger assembly in a firearm. The override trigger assembly is preferably provided in an open design configuration.
A first embodiment of a method according to the present invention comprises the steps of removing a direct pull trigger assembly from a firearm and coupling to the firearm an override trigger assembly, which may be an open design assembly. The firearm may be a bolt action rifle.
A second embodiment of a method according to the present invention comprises the steps of removing a closed design override trigger assembly from a firearm and coupling to the firearm an open design override trigger assembly. The firearm may be a bolt action rifle.
An embodiment of a firearm trigger assembly according to the present invention includes three levers, a first lever, a second lever, and a third lever. The first lever extends between a first lever first end and a first lever second end and includes a second-lever engagement means, which may comprise a notch and may be located closer to the first lever first end than to the first lever second end. The first lever is pivotable about a first lever axis and the first lever is biased in a first rotational direction about the first lever axis, which may be located closer to the first lever second end than to the first lever first end. The second lever extends between a second lever first end and a second lever second end and includes a protrusion, such as a wedge, formed thereon. The second lever is pivotable about a second lever axis and the second lever is biased in a second rotational direction about the second lever axis, which is at least substantially parallel with the first lever axis. The third lever extends between a third lever first end and a third lever second end and including a lower rocker surface and an upper pin surface, wherein the third lever is pivotable about a third lever axis, which is at least substantially parallel to the first lever axis. The levers generally cooperate in such a way to maintain a firearm firing pin in a cocked position. The second-lever engagement means rests in contact with the protrusion to prevent rotation of the second lever opposite the second and the third lever is prevented from rotating in a third rotational direction about the third lever axis by the contact of the lower rocker surface with the second lever.
According to one aspect of an embodiment of a firearm trigger assembly according to the present invention, the first lever axis and the second lever axis may lie in a first plane, and the first lever axis and the third lever axis may lie in a second plane, which may be different from the first plane. The first plane and second plane may be arranged perpendicular to each other.
According to another aspect of an embodiment of a firearm trigger assembly according to the present invention, the assembly may further comprise a support bracket, wherein one or more of the levers are pivotably mounted to the support bracket by a bearing disposed coaxial with the associated lever axis. The support bracket may further comprise a mounting structure to assist in coupling the bracket to a firearm, wherein the mounting structure may comprise a mounting yoke.
According to yet another aspect of an embodiment of a firearm trigger assembly according to the present invention, one or more of the second rotational direction and the third rotational direction is/are eccentric to and opposite of the first rotational direction.
According to still another aspect of an embodiment of a firearm trigger assembly according to the present invention, the first lever may be biased in the first rotational direction about the first lever axis by a spring. Additionally or alternatively, the second lever may be biased in the second rotational direction about the second lever axis by a spring acting on a surface of the second lever located between the second lever axis and the second lever second end.
An embodiment of a method according to the present invention comprises the steps of providing a firearm having a firing pin and a first trigger assembly configured to cooperate with the firing pin to maintain the firing pin in a cocked position, removing the first trigger assembly from the firearm, and installing a second trigger assembly on the firearm. Embodiments of the second trigger assembly are described above and hereafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of a trigger assembly according to the present invention.
FIG. 2 is a left side elevation view of the embodiment of FIG. 1 .
FIG. 3 is a right side elevation view of the embodiment of FIG. 1 .
FIG. 4 is a left side elevation view of a prior direct-pull trigger assembly installed in a firearm.
FIG. 5 is a second left side elevation view of the assembly of FIG. 4 in a pulled orientation.
FIG. 6 is a left side elevation view of a prior closed design, or housed, trigger assembly.
FIG. 7 is a left side elevation view of the embodiment of FIG. 1 , in a cocked position, installed on the same firearm depicted in FIG. 4 after the direct-pull trigger was removed.
FIG. 8 is the same view as FIG. 7 , except that the trigger has been pulled.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
Turning now to the figures, FIGS. 1-3 depict a first embodiment 100 of a trigger assembly according to the present invention. The trigger assembly 100 generally includes a support bracket 110 , a trigger lever 150 , a transfer lever 170 , and a sear lever 190 . The support bracket 110 extends longitudinally throughout a bracket length 112 from a first bracket end 114 to a second bracket end 116 . The support bracket 110 has a top side 118 and a bottom side 120 coupled together by lateral sides 122 , which extend between the first bracket end 114 and the second bracket end 116 . Formed along at least a portion of the bracket length 112 and extending through the top side 118 and bottom side 120 is a sear channel 124 . Depending downward from and forming a part of the bracket bottom side 120 is a first bearing yoke 126 and a second bearing yoke 128 . Extending upward from and forming a part of the bracket top side 118 is a mounting yoke 130 . Extending through the bracket top side 118 , between the mounting yoke 130 and the first bracket end 114 is a stabilizing screw 140 , which is threadably engaged with the mounting bracket 110 .
The trigger lever 150 generally extends from a first free end 152 to a second end 154 , and includes an upper transfer surface 156 extending therebetween. Disposed on the upper transfer surface 156 , closer to the first free end 152 than the second end 154 is at least one transfer lever engagement means 158 , such as a notch 159 . Extending upward from and forming part of the upper transfer surface 156 , closer to the second end 154 than the first free end 152 , is a mounting shank 160 . Extending from the trigger lever 150 , preferably between the mounting shank 160 and the second end 154 , is a trigger travel limiter 162 , which in one embodiment may be a hex screw 163 extending through and threadably engaged with the trigger lever 150 . Also provided is a trigger lever bias means 164 , which is preferably a coiled trigger bias spring 165 having a desirable spring constant. The trigger bias spring 165 may be sleeved over the travel limiting screw 163 , and may engage a bias adjustment nut 166 , which is threadably engaged with the screw 163 . Thus, as the nut 166 is threadably adjusted away from the trigger lever 150 , the spring 165 is compressed so as to increase the bias force of the trigger lever 150 in a trigger bias direction 167 . Extending downward from the trigger lever 150 is a preferably concave trigger engagement surface 168 extending from the trigger lever 150 to a free trigger end 169 .
The transfer lever 170 generally extends from a free end 172 to a bias end 174 , and includes an upper sear interface surface 176 extending therebetween. The sear interface surface 176 extends generally planarly from the free end 172 towards the bias end 174 . The sear interface surface 176 is preferably generally smooth so as to provide a minimal frictional interface between the transfer lever 170 and the sear lever 190 . However, extending upward from and forming part of the sear interface surface 176 , preferably closer to the second end 174 than the first end 172 , is a mounting shank 178 . Extending downward from the transfer lever 170 , opposite the sear interface surface 176 , is a transfer wedge 180 , including a distal edge 182 , which may be peaked or slightly rounded. Extending from the transfer lever 170 , preferably between the mounting shank 178 and the bias end 174 , is a transfer lever bias means 184 , which is preferably a coiled transfer lever bias spring 185 having a desirable spring constant.
The sear lever 190 generally extends from a free end 191 to a mounting end 192 , and includes an upper pin surface 193 and a lower rocker surface 194 . Extending upward from the upper pin surface 193 is a sear pin 195 . The sear pin 195 is preferably generally a parallelepiped, including a sloped, preferably planar safety surface 196 disposed between a front surface 197 and a rear firing pin engagement surface 198 . The safety surface 196 is preferably formed such that when the trigger assembly 100 is in its cocked position, the safety surface 196 is disposed at a desirable angle α with respect to the direction of travel of a firing pin 502 . A desirable angle α may be between five and sixty degrees, but a more preferred angle α is between ten and twenty degrees, with about fourteen degrees being most preferred. The lower rocker surface 194 is formed at a desired radius, preferably between about 0.100 inches and about 0.400 inches, with about 0.200 inches being preferred.
Generally, the transfer lever 170 is pivotally mounted to the first bearing yoke 126 by a transfer bearing 171 , the trigger lever 150 is pivotally mounted to the second bearing yoke 128 by a trigger bearing 151 , and the sear lever 190 is situated at least partially within the sear channel 124 and is pivotally mounted to the support bracket 110 by a sear bearing 199 . The bearings 151 , 171 , 199 are preferably coaxially disposed with associated lever axes 151 a , 171 a , 199 a about which each respective lever 150 , 170 , 190 is pivotable.
FIGS. 4 and 5 depict a prior art direct pull trigger assembly 600 installed on a firearm action 500 . The prior assembly 600 includes a support bracket 610 and a trigger lever 650 pivotally connected thereto. The support bracket 610 includes a mounting yoke 630 , which is adapted to be pivotally mounted to the housing 504 of the firearm action 500 . Towards a free end 612 of the support bracket 610 , and extending upward therefrom, is a sear pin 690 , which extends into the firearm action 500 and is adapted to restrain the firing pin (not shown) when the action 500 is in a cocked position. At the top of the trigger lever 650 , there is formed a cam surface 652 . The cam surface 652 is adapted, when the trigger lever 650 is pulled in a first direction 520 , to rock against the housing 504 of the firearm action 500 . Such motion forces the support bracket 610 , and in turn the sear pin 690 , also to move in a second direction 522 , which allows the firing pin (not shown) to be released and to strike an ammunition round (not shown) loaded into the firearm action 500 . As the sear pin 690 is lowered in the second direction 522 , however, the top of the sear pin 690 is actually moving against the bias force of the firing pin (not shown), thereby increasing frictional forces, which may result in decreased performance over time.
FIG. 6 shows a prior art closed design, or housed, override trigger assembly 700 installed on a firearm action 500 . The prior assembly 700 includes support plates 710 , which obscure and house the override trigger actuation mechanism. Indeed, the entire trigger action of the assembly 700 , except of course a trigger lever 750 , is obscured. The trigger lever 750 extends from between the plates 710 to allow for actuation. The trigger assembly 700 is mounted to the firearm action 500 by a mounting yoke 730 , and held stationary to the action 500 by a threaded stabilizing screw 740 . While the housed trigger assembly 700 may be disassembled to be serviced or cleaned, such as by removing, e.g., retaining rings 780 , such disassembly is accompanied by the high risk of component damage, loss, or misplacement. Another disadvantage of this design is an increased lock time over prior direct pull triggers. The cause of an increased lock time is thought to be the use of a relatively strong counterbalance spring that is used to decrease wear of the trigger action.
FIG. 7 shows an embodiment 100 of a trigger assembly according to the present invention installed on a firearm action 500 , the trigger assembly 100 shown in a cocked position. After a factory or prior after-market trigger assembly is removed from the firearm as is known, the assembly 100 is installed by coupling the mounting yoke 130 to the firearm action 500 with a mounting pin 111 , and securing the assembly in place by tightening the stabilizing screw 140 against the firearm action 500 . Thus, a method according to the present invention includes the steps of removing a direct pull trigger assembly, such as the trigger assembly 600 shown in FIG. 5 , from a firearm, such as a bolt action rifle, and installing an open design trigger assembly according to the present invention, thereby replacing the removed direct pull trigger assembly. A second method according to the present invention includes the steps of removing a closed design, or housed, override trigger assembly, such as the trigger assembly 700 of FIG. 6 , from a firearm, such as a bolt action rifle, and installing an open design trigger assembly according to the present invention, thereby replacing the removed closed design, or housed, override trigger assembly. The method of removal of an extant direct pull or closed design override trigger assembly is generally within the skill of ordinary artisans in the trade.
As can be seen, an open design assembly may provide access to substantially the entire trigger assembly from both lateral sides thereof. Preferably, such access is provided upon simple removal or separation from a firearm without further disassembly. In the depicted three-lever embodiment, there is a first contact point 301 between the transfer lever 170 and the trigger lever 150 . There is a second contact point 302 between the transfer lever 170 and the sear lever 190 . While the support bracket 110 has been shown manufactured in a way to allow access to both contact points 301 , 302 in both the cocked and pulled states, it is to be understood that the support bracket 110 may slightly cover one or both points. In this cocked state, the firing pin (not shown) has been automatically or manually retracted to allow the transfer bias means 184 to bias both the transfer lever 170 and the sear lever 190 upwards. The distal edge 182 of the transfer wedge 180 is then nestled into the transfer lever engagement means 158 so as to generally lock the assembly in the cocked position. The firing pin (not shown) is then automatically or manually allowed to rest against the sear pin 190 , and the weapon is ready for firing.
FIG. 8 shows the trigger assembly 100 after the pulling of the trigger lever 150 in the first direction 520 . The force in such first direction 520 needs to overcome the biasing force of the trigger lever biasing means 164 , thus compressing 525 the trigger bias spring 165 . The travel of the trigger lever 150 , which may be limited by the trigger travel limit screw 163 , releases the distal edge 182 of the transfer wedge 180 from the transfer lever engagement means 158 . The bias force of the firing pin (not shown) is thus allowed to overcome the retention force supplied to the sear pin 190 by the transfer lever bias spring 185 , thus causing the sear lever to rotate in a third direction 526 , which in turn causes the transfer lever 170 to rotate in a fourth direction 527 , compressing 528 the transfer lever bias spring 185 . The trigger assembly 100 may be returned to the cocked position of FIG. 7 by automatically or manually drawing the firing pin rearward to allow the biasing mechanisms 164 , 184 to bias the sear pin 195 upward to engage a portion of the firing pin.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. For instance, while the design shown has been adapted and sized to cooperate with an M98 bolt action rifle available from Mauser Jagdwaffen GmbH of Isny, Germany, the general design of the support bracket 110 , including the bracket length 112 and mounting yoke 130 can be modified as required to accommodate the mounting mechanism included on other firearms, such as Springfield and Enfield bolt action rifles, onto which an embodiment according to the present invention may be installed. Such modification to the support bracket 110 is considered to be within the skill of the art, including various machining and casting techniques.
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Provided are systems and methods related to firearm trigger assemblies. An open design trigger assembly is provided to allow easier access to the trigger action. The trigger assembly is preferably an override trigger assembly, which may include adjustable trigger travel limiter and trigger bias force. Methods according to the present invention include a first step of removing either a direct-pull or a closed design trigger assembly from a firearm and replacing such removed assembly with an open design override trigger assembly.
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