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BACKGROUND OF THE INVENTION
This invention relates to pressure seals and more particularly to the gasketing of joints in high pressure equipment with ring-type gaskets.
In the melt spinning of polymers it is customary to force the molten polymer under high pressure through a filter to remove particles which might clog the spinneret or impair the quality of the yarn. At these high pressures difficulty has been encountered in finding adequate means for sealing the filter assembly to prevent polymer leaks.
Gill et al. in their U.S. Pat. No. 2,980,284 propose the use of a band-type gasket which requires very little compressive force for a satisfactory seal. As they state, gaskets which seal by being compressed between two parts are not satisfactory because at high polymer pressures the degree of compression required to hold the gasket in place is excessive and even with higher compressive force these gaskets frequently fail.
SUMMARY OF THE INVENTION
An effective compression ring-type gasket has been provided to overcome this problem. The gasket is made of cold-flowable material and has an inner peripheral surface that includes a circumferential groove. This structural arrangement facilitates the outward diametrical expansion of the ring as it is being compressed between the two parts forming the seal.
In the preferred embodiment of the invention the circumferential groove has a semicircular cross section and the ring gasket is tetra-sided.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a top view of a preferred gasket of this invention.
FIG. 2 is a cross sectional view taken along line 2--2 of FIG. 1.
FIG. 3 illustrates the functioning of the gasket of this invention in a container.
FIG. 4 shows the position of the gasket in the container groove after closing the container but before the application of compression force to the gasket.
FIG. 5 shows the position of the gasket of FIG. 4 and its extent of outward diametrical expansion after a compressive force is applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, the gasket 10 of this invention is shown to be in the form of a continuous ring of metal that will cold flow when compressed. Suitable metals are aluminum, copper, and bronze. The height of this particular gasket is indicated by (h) and the cross sectional thickness by (t). The gasket has four sides and the side forming the inner peripheral surface 12 has a circumferential groove 14 formed therein.
FIGS. 3-5 illustrates the functioning of this gasket in a container designed for filtering polymer preparatory to spinning the polymer into fibers. The container 16 comprises a body 18 and a lid 20 which is releasably joined to the body by threaded bolts 22. In this application of the container the body cavity contains sand as a filter medium. Polymer is admitted to the container through conduit 13 and emitted through conduits 15. Screen 17 prevents entrainment of sand. There are matching annular V-shaped grooves 19,21 in the juncture surfaces of the body and lid respectively which form a chamber for the gasket 10.
It is essential that the gasket height h be greater than the combined depth of V-shaped grooves 19,21 to permit compression of the gasket before the lid and body juncture surfaces meet. Referring to FIGS. 4 and 5 it can be seen that as the ring gasket 10 is compressed between lid 20 and body 18 outward diametrical expansion of gasket 10 increases the thickness t to t' while reducing the height h to h'. The groove 14 facilitates outward diametrical expansion of the ring gasket 10 and as the gasket is deformed it is wedged into the triangular chamber formed by V-shaped grooves 19,21 in the lid and the body of the container increasing the sealing contact area of the gasket.
The pressure seal of this invention is particularly effective in the melt spinning of polymers, but it may be used to advantage in many applications where sealing at high pressures and temperatures is required.
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The addition of a circumferential groove in the inner peripheral surface of the ring gasket made of cold-flowable metal induces diametrical expansion of the gasket during compression.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus for organic synthesis and reactions and, more particularly, to an apparatus which is used for organic synthesis and reactions and permits analysis of reaction mechanisms and reaction intermediate structures.
[0003] 2. Description of Related Art
[0004] A technique for causing plural substances to mix and react with each other in a quite small space is known as microchip technology or microreactor technology and expected to be put into practical use to provide increased chemical reaction rates and improved efficiencies.
[0005] Microchip reactors for chemical synthesis are often made of glass because of their excellent chemical resistance. Since it is difficult to directly connect a tube, which is used to introduce a synthesis reagent, with a microchannel in a microchip made of glass, it is customary to connect the tube with a holder via a connector after the microchip reactor is held with the holder.
[0006] At tube joints, O-rings are often used to prevent liquid leakage. Therefore, eluates from rubber members and dead volume often present problems. In one available method, a tube is adhesively fixed to the surface of a glass reactor. However, depending on the used solvent, there is the possibility that the adhesive dissolves out. Furthermore, it is possible to machine a threaded structure into a glass material, the structure being used for connection of tubes of liquid chromatographs. Nonetheless, a high level of technique is required to machine the structure, and high cost is necessary.
[0007] Furthermore, a reagent solution having high viscosity may be used depending on the kind of synthesis reaction. The reagent may clog up the channel after introduction of the reagent. Especially, the channel tends to be clogged up near tube joints.
[0008] Microreactor products used for chemical synthesis have already been sold from some manufacturers. The microreactors are chiefly made of glass. A digital representation of a commercially available microreactor for mixing of two reagents is shown in FIG. 7 . The glass microreactor is composed of two plates. A microchannel is formed in one of the plates. A fluid inlet hole and a fluid exit hole are formed in the other. The two plates are bonded together by thermocompression.
[0009] This microreactor is held to a holder. Tubes for introduction of reagents are connected with the microreactor using connectors. The tubes are connected with syringe pumps. Reagent solutions are introduced into the microreactor by the syringe pumps. The introduced reagents are made to meet at the Y-shaped portion of the channel and mixed. The reagents are made to react with each other in the downstream channel, thus producing reaction products.
[0010] A well-known on-line method of detecting reaction products is a thermal lens microscope technique. Where a measurement is performed using a mass spectrometer (MS) or nuclear magnetic resonance spectrometer (NMR) to make structural analysis of reaction products, it is required that the reaction products be collected at the exit of the microreactor and that the sample be introduced into the MS or NMR off-line.
[0011] Vigorous research is now underway to connect a microchip reactor or microreactor having various functions with an MS or NMR having high qualitative analysis capabilities in an on-line manner to perform analyses. See Japanese Utility Model No. S57-75558 and Published Technical Report No. 2004-502547 of the Japan Institute of Invention and Innovation. There are the following research reports:
[0012] (1) Microchip-NMR
[0013] A monograph has been published describing research in which a circular liquid reservoir is formed in a channel within a microchip reactor as shown in FIG. 8 , a microcoil is brought close to the reservoir, and a trace amount of sample is investigated. J. H. Walton et al., Analytical Chemistry, Vol. 75, pp. 5030-5036 (2003). Microcoils or probes dedicated for microchip reactors are at a research stage. There are almost no applications to chemical synthesis.
[0014] (2) Flow NMR
[0015] Reaction reagents are mixed and reacted with each other using a static mixer. The reaction liquid is guided into a probe for flow NMR via a line, and an NMR measurement is performed. This research is at a practical level. The experiment needs a flow NMR probe. Furthermore, there is a drawback that the distance from the reaction portion to the position in the NMR magnet irradiated with an RF magnetic field is long.
[0016] (3) Microchip-MS
[0017] As shown in FIG. 9 , when a microchip reactor is fabricated, a nanoelectrospray nozzle is integrated with the microchip reactor. J. Kameoka et al., Analytical Chemistry, Vol. 74, pp. 5897-5901 (2002). Mass analysis is enabled by applying a high voltage to the nozzle. There are more applications in the biological field than in synthetic chemistry.
[0018] Microchip reactors and microreactors for chemical analysis have the following problems.
[0019] (1) Since the microreactor is of the integrated construction, parts cannot be replaced. Therefore, if the channel or a tube joint is clogged up, the whole microreactor must be replaced. If the microreactor is made of glass, the running cost is high.
[0020] (2) Eluates from the material of the connector and dead volume present problems.
[0021] (3) When reaction products are detected on-line, usable detectors are limited to those using absorption of light.
[0022] (4) When structural analysis of reaction products is performed using an analytical instrument, it is normally necessary to introduce a sample in an off-line manner.
[0023] Where on-line detection using a combination of a microchip reactor and an analytical instrument consisting of an NMR is performed, there are the following problems:
[0024] (1) It is necessary to design and develop a dedicated NMR probe. This needs an exorbitant amount of initial investment.
[0025] (2) Since the design of the microchip reactor is dedicated for NMR, it is difficult to connect the reactor directly with other detectors.
[0026] Where on-line detection using a combination of a microchip reactor and an analytical instrument consisting of a flow NMR spectrometer is performed, there are the following problems.
[0027] (1) It is necessary to design and develop a dedicated flow probe. This necessitates a huge amount of initial investment.
[0028] (2) It is difficult to place the reaction portion into the probe. Normally, the reaction portion is placed outside the magnet. Consequently, there is a time lag from reaction to detection.
[0029] Where on-line detection using a combination of a microchip reactor and an analytical instrument consisting of an MS is performed, there are the following problems:
[0030] (1) There are only few examples of application to chemical synthesis.
[0031] (2) The design of the microchip reactor is dedicated for MS. It is difficult to connect the microchip reactor directly with other detectors.
SUMMARY OF THE INVENTION
[0032] The present invention has been made in view of the foregoing problems. It is an object of the present invention to provide a microchip reactor which is for use in organic synthesis and which can be used in combination with many analytical instruments.
[0033] This object is achieved in accordance with the teachings of the present invention by an organic synthesis reactor in which fluids are mixed in a very narrow space and reacted in multiple stages. The reactor has an introduction portion for introducing plural reagents from plural channels and a reaction portion disconnectably connected with the introduction portion. Where needed, the introduction portion mixes the introduced reagents and causes them to react with each other. In the reaction portion, a reagent or reaction liquid introduced from the introduction portion is mixed and reacted with other reagents. The introduction portion has an inlet channel for introducing a reagent, introduced from the outside, into the reaction portion and a first discharge channel for discharging the reaction liquid, discharged from the reaction portion, to the outside. The reaction portion has a reaction channel in communication with the inlet channel and a second discharge channel. The reaction channel causes plural reagents sent in from the inlet channel to mix and react. The second discharge channel places the reaction channel into communication with the first discharge channel to return the reaction liquid produced in the reaction channel to the introduction portion.
[0034] In one feature of the present invention, the introduction portion is a microchip having a substrate made of a resin having chemical resistance. The substrate is provided with a microchannel. The reaction portion is a microchip having a substrate made of glass or quartz, the substrate being provided with a microchannel.
[0035] In another feature of the present invention, the introduction portion has an inlet hole for introducing a reagent and a discharge hole for discharging the reaction liquid. The inlet hole and the discharge hole are flush with each other.
[0036] In a further feature of the present invention, the microchannels are formed on both surfaces of the substrate made of glass or quartz by wet etching or drilling. Then, the substrate having the microchannels is sandwiched between two plates of glass or quartz. The substrate and the plates are bonded together by thermocompression, thus completing the reactor.
[0037] In yet another feature of the present invention, the substrate has a thickness of 1 to 5 mm.
[0038] In an additional feature of the present invention, the reaction portion has been finished in a cylindrical or prismatic form having a length of 50 to 300 mm and a maximum width of 2 to 10 mm.
[0039] In still another feature of the present invention, the microchannels have a width and a depth of 50 to 500 μm.
[0040] In yet an additional feature of the present invention, the reaction portion has a detection portion used in combination with an analytical instrument for analyzing the reaction liquid.
[0041] In still a further feature of the present invention, the analytical instrument is at least one of NMR, ESR, and thermal lens microscope.
[0042] In an additional feature of the present invention, an electrospray nozzle for use in combination with a mass spectrometer (MS) for analyzing the reaction liquid is mounted in the discharge hole in the introduction portion for discharging the reaction liquid.
[0043] Because the organic synthesis reactor according to an embodiment of the present invention is designed as described above, the reactor can be fabricated in a microchip form capable of being used in combination with many analytical instruments.
[0044] Other objects and features of the invention will appear in the course of the description thereof, which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIGS. 1A, 1B and 1 C schematically show an organic synthesis reactor according to one embodiment of the present invention;
[0046] FIGS. 2A, 2B and 2 C schematically show an organic synthesis reactor according to another embodiment of the present invention;
[0047] FIGS. 3A and 3B schematically show an organic synthesis reactor according to a further embodiment of the present invention;
[0048] FIG. 4 is a cross-sectional view of a thermal lens microscope that embodies an organic synthesis reactor according to an embodiment of the present invention;
[0049] FIG. 5 is a cross-sectional view of an NMR spectrometer that embodies an organic synthesis reactor according to an embodiment of the present invention;
[0050] FIG. 6 is a cross-sectional view of a mass spectrometer that embodies an organic synthesis reactor according to an embodiment of the present invention;
[0051] FIG. 7 shows a commercially available microchip;
[0052] FIG. 8 shows a related-art technique in which a microchip is applied to an NMR spectrometer; and
[0053] FIG. 9 shows another related-art technique in which a microchip is applied to a mass spectrometer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Embodiments of the present invention are hereinafter described with reference to the accompanying drawings.
FIRST EMBODIMENT
[0055] Referring to FIGS. 1A, 1B and 1 C, there is shown an organic synthesis reactor according to one embodiment of the present invention. The reactor has a reagent introduction-and-reaction portion 2 that is connected at a contact portion 4 with an extensional reaction portion 1 via a connector jig 3 .
[0056] The extensional reaction portion 1 is made of a glass substrate having a thickness of 1 to 5 mm. Microchannels are formed on both surfaces of the glass substrate by wet etching or drilling. The glass substrate 1 a is provided with a through-hole 12 to permit a reagent solution to flow from the channel in the front surface to the channel in the rear surface.
[0057] The width and depth of the channels are 50 to 500 μm. The design of the channels and machining method can be modified according to the purpose of use.
[0058] The glass substrate having the microchannels are then held between two glass plates. The glass substrate 1 a and glass plates 1 b , 1 c are bonded together by thermocompression. The whole assembly is finished in a cylindrical or prismatic form by a cutting technique. Alternatively, a glass stock may be machined into a semicylindrical form, and microchannels may be formed in this semicylindrical form. Preferably, the length of the extensional reaction portion 1 is 50 to 300 mm. The diameter of the cylindrical form or the maximum width of the prismatic form is 2 to 10 mm.
[0059] Screw holes are formed in the reagent introduction-and-reaction portion 2 to permit connection of tubes. Also, channels are formed in this portion 2 . When the extensional reaction portion 1 and the reagent introduction-and-reaction portion 2 have been connected, their channels are aligned. Consequently, a reagent solution can be passed through the channels.
[0060] The connector jig 3 has guide portions to facilitate aligning the extensional reaction portion 1 and reagent introduction-and-reaction portion 2 . The contact portion 4 is surface-treated or used in combination with a sealant to prevent liquid leakage.
[0061] Three reagent inlet holes 5 are formed in the reagent introduction-and-reaction portion 2 . Two of the three inlet holes 5 meet each other and are combined into one conduit immediately ahead of a first reaction portion 7 formed within the reagent introduction-and-reaction portion 2 . The conduit passes through the first reaction portion 7 of the bent (e.g., serpentine) channel, where a first reaction between reagents is produced. The conduit is in communication with a first reaction liquid channel 8 formed in the extensional reaction portion 1 .
[0062] A reagent inlet channel 6 extends from the remaining one of the reagent inlet holes 5 and meets the first reaction liquid channel 8 in a second reaction-and-mixture portion 9 formed in the extensional reaction portion 1 , thus forming one conduit. This conduit is in communication with a second reaction portion 10 of the bent (e.g., serpentine) channel, where a second reaction between the reagents is induced.
[0063] The second reaction portion 10 is in communication with a detection channel 11 of the bent (e.g., serpentine) channel. The second reaction portion 10 passes through a through-hole 12 and reaches the rear side of the extensional reaction portion 1 , the through-hole 12 being formed in the vertical direction. The second reaction portion 10 then passes into the reaction liquid discharge hole 14 through a reaction liquid discharge channel 13 . The three reagent inlet holes 5 and reaction liquid discharge hole 14 are formed in the same side surface of the reagent introduction-and-reaction portion 2 .
[0064] In this way, in the present embodiment, the microchannels in the microchip are formed in both top surface side and bottom surface side of the reagent introduction-and-reaction portion 2 and extensional reaction portion 1 . That is, the present embodiment is characterized in that there are two layers of channels.
[0065] Preferably, the material of the organic synthesis reactor is so selected that the reactor can be used in a temperature range from −70° C. to +200° C. To permit mass production using a molding technique, the reagent introduction-and-reaction portion 2 is preferably made of a chemical-resistant resin, such as PEEK (polyetheretherketone), Teflon™, or Diflon. Preferably, the extensional reaction portion 1 is made of glass or quartz.
[0066] Where viscous reagents are used, the channels inside the reagent introduction-and-reaction portion 2 tend to be clogged up especially easily. Consequently, it can be anticipated that the running cost of the reactor in operation will be reduced by designing this portion tending to be clogged up as a replaceable external part attached to the extensional reaction portion 1 .
SECOND EMBODIMENT
[0067] FIGS. 2A, 2B and 2 C show an organic synthesis reactor according to another embodiment of the present invention. The reactor has a reagent inlet portion 22 that is connected at a contact portion 24 with a reagent reaction portion 21 via a connector jig 23 .
[0068] The reagent reaction portion 21 is made of a glass substrate having a thickness of 1 to 5 mm. Microchannels are formed on both surfaces of the glass substrate by wet etching or drilling. The glass substrate is provided with a through-hole 33 to permit a reagent solution to flow from the channel in the front surface to the channel in the rear surface.
[0069] The width and depth of the channels are 50 to 500 μm. The design of the channels and machining method can be modified according to the purpose of use.
[0070] The glass substrate having the microchannels is then held between two glass plates. The glass substrate and glass plates are bonded together by thermocompression. The whole assembly is finished in a cylindrical or prismatic form by a cutting technique. Alternatively, a glass stock may be machined into a semicylindrical form, and microchannels may be formed in this semicylindrical form. Preferably, the length of the reagent reaction portion 21 is 50 to 300 mm. The diameter of the cylindrical form or the maximum width of the prismatic form is 2 to 10 mm.
[0071] Screw holes are formed in the reagent inlet portion 22 to permit connection of tubes. Also, channels are formed in the inlet portion 22 . When the reagent reaction portion 21 and the reagent inlet portion 22 have been connected, their channels are aligned. Consequently, a reagent solution can be passed through the channels.
[0072] The connector jig 23 has guide portions to facilitate aligning the reagent reaction portion 21 and reagent inlet portion 22 . The contact portion 24 is surface-treated or used in combination with a sealant to prevent liquid leakage.
[0073] Three reagent inlet holes 25 are formed in the reagent inlet portion 22 and are in communication with three reaction liquid channels 27 , respectively, formed in the reagent reaction portion 21 .
[0074] Two of the three inlet holes 25 meet each other and are combined into one conduit in the first reaction-and-mixture portion 28 . The conduit is in communication with the first reaction portion 29 of the bent (e.g., serpentine) channel, where a first reaction between reagents is produced. The conduit then meets another reaction liquid channel 27 in the second reaction-and-mixture portion 30 to form one conduit which is in communication with the second reaction portion 31 of the bent (e.g., serpentine) channel, where a second reaction between the reagents is induced.
[0075] The second reaction portion 31 is in communication with a detection channel 32 of the bent (e.g., serpentine) channel. The detection channel 32 passes through a through-hole 33 and reaches the rear side of the reagent reaction portion 21 , the through-hole 33 being formed in the vertical direction. The second reaction liquid then passes into the reaction liquid discharge hole 35 through a reaction liquid discharge channel 34 . The three reagent inlet holes 25 and reaction liquid discharge hole 35 are formed in the same side surface of the reagent inlet portion 22 .
[0076] In this way, in the present embodiment, the microchannels in the microchip are formed in both top surface side and bottom surface side of the reagent inlet portion 22 and reagent reaction portion 21 . That is, the present embodiment is characterized in that there are two layers of channels.
[0077] Preferably, the material of the organic synthesis reactor is so selected that the reactor can be used in a temperature range from −70° C. to +200° C. To permit mass production using a molding technique, the reagent inlet portion 22 is preferably made of a chemical-resistant resin, such as PEEK (polyetheretherketone), Teflon™, or Diflon. Preferably, the reagent reaction portion 21 is made of glass or quartz.
[0078] Where viscous reagents are used, the channels inside the reagent inlet portion 22 tend to be clogged up especially easily. Consequently, it can be anticipated that the running cost of the reactor in operation will be reduced by designing this portion tending to be clogged up as a replaceable external part attached to the reagent reaction portion 21 .
THIRD EMBODIMENT
[0079] FIGS. 3A and 3B show an organic synthesis reactor according to a further embodiment of the present invention. The reactor has a reagent inlet portion 52 that is connected at a contact portion 54 with a reagent reaction portion 51 via a connector jig 53 and using screws 55 .
[0080] The reagent reaction portion 51 is made of a glass substrate having a thickness of 1 to 5 mm. Microchannels are formed on both surfaces of the glass substrate by wet etching or drilling. The glass substrate is provided with a through-hole 64 to permit a reagent solution to flow from the channel in the front surface to the channel in the rear surface.
[0081] The width and depth of the channels are 50 to 500 μm. The design of the channels and machining method can be modified according to the purpose of use.
[0082] The glass substrate having the microchannels is then held between two glass plates. These glass substrate and glass plates are bonded together by thermocompression. One end portion of the assembly is cut into an elongated T-shaped form. The end portion of the reagent reaction portion 51 is shaped like the letter T to press and join the reagent inlet portion 52 by the connector jig 53 . The T-shaped end portion of the reagent reaction portion 51 is made asymmetrical right and left to prevent the senses of the reagent reaction portion 51 and reagent inlet portion 52 from being confused when they are connected. The connector jig 53 has a structure for recognizing the asymmetrical portion or an asymmetrical fitting portion.
[0083] Screw holes are formed in the reagent inlet portion 52 to permit connection of tubes. Also, channels are formed in the inlet portion 52 . When the reagent reaction portion 51 and the reagent inlet portion 52 have been connected, their channels are aligned. Consequently, a reagent solution can be passed through the channels. The contact portion 54 is surface-treated or used in combination with a sealant to prevent liquid leakage.
[0084] Three reagent inlet holes 56 are formed in the reagent inlet portion 52 and are in communication via three reagent inlet channels 57 , respectively, with three reaction liquid channels 58 , respectively, formed in the reagent reaction portion 51 .
[0085] Two of the three inlet holes 56 meet each other and are combined into one conduit in the first reaction-and-mixture portion 59 . The conduit is in communication with the first reaction portion 60 of the bent (e.g., serpentine) channel, where a first reaction between reagents is produced. The conduit then meets another reaction liquid channel in the second reaction-and-mixture portion 61 to form one conduit which is in communication with the second reaction portion 62 of the bent channel, where a second reaction between the reagents is induced.
[0086] The second reaction portion 62 is in communication with a detection channel 63 of the bent channel. The second reaction liquid passes through a through-hole 64 and reaches the rear side of the second reagent reaction portion 62 , the through-hole 64 being formed in the vertical direction. The second reaction liquid then passes into the reaction liquid discharge hole 66 through a reaction liquid discharge channel 65 . The three reagent inlet holes 56 and reaction liquid discharge hole 66 are formed in the same side surface of the reagent inlet portion 52 .
[0087] In this way, in the present embodiment, the microchannels in the microchip are formed in both top surface side and bottom surface side of the reagent inlet portion 52 and reagent reaction portion 51 . That is, the present embodiment is characterized in that there are two layers of channels.
[0088] Preferably, the material of the organic synthesis reactor is so selected that the reactor can be used in a temperature range from −70° C. to +200° C. To permit mass production using a molding technique, the reagent inlet portion 52 is preferably made of a chemical-resistant resin, such as PEEK (polyetheretherketone), Teflon™, or Diflon. Preferably, the reagent reaction portion 51 is made of glass or quartz.
[0089] Where viscous reagents are used, the channels inside the reagent inlet portion 52 tend to be clogged up especially easily. Consequently, it can be anticipated that the running cost of the reactor in operation will be reduced by designing this portion tending to be clogged up as a replaceable external part attached to the reagent reaction portion 51 .
FOURTH EMBODIMENT
[0090] FIG. 4 shows one embodiment of the present invention in which such an organic synthesis reactor is mounted in various analytical instruments. Liquid delivery modules 36 , 37 , and 38 , such as syringe pumps, are connected with the organic synthesis reactor by tubes, such as capillaries.
[0091] Reagent solutions sent out from the liquid delivery modules 36 and 37 are mixed by a mixing portion 28 where channels intersect. The solutions are reacted in a first reaction portion 29 . The reagent solutions reacted in the first reaction portion are mixed with a reagent introduced from the liquid delivery module 38 in a mixing portion 30 located immediately behind the first reaction portion 29 . Thus, a second stage of reaction is induced in a second reaction portion 31 . Instead of the reagent, a reaction inhibitor or diluting solvent may be introduced from the liquid delivery module 38 . The reaction liquid obtained in the second reaction portion 31 is introduced into a detection channel 32 , where the reaction products are detected by a thermal lens microscope 39 . Then, the reaction liquid is discharged out of the organic synthesis reactor from a reaction liquid discharge hole 35 through a through-hole 33 and through a reaction liquid discharge channel 34 in the rear surface. The liquid is then recovered.
FIFTH EMBODIMENT
[0092] FIG. 5 shows an embodiment of the present invention in which the organic synthesis reactor is mounted in an NMR spectrometer. The organic synthesis reactor can be directly attached to the NMR spectrometer 40 of normal construction. The reactor and liquid delivery modules are connected by tubes, such as capillaries. The reactor is mounted to an NMR sample tube holder having a diameter of 5 mm and to a rotor and inserted into an NMR probe having a diameter of 5 mm (finding the widest use). Under this condition, the reactor is used instead of an NMR sample tube. The organic synthesis reactor may also be combined with an electron spin resonance (ESR) spectrometer by a similar method.
SIXTH EMBODIMENT
[0093] FIG. 6 shows an embodiment of the present invention in which the organic synthesis reactor is mounted in a mass spectrometer (MS). With the organic synthesis reactor, MS detection can be easily performed simply by connecting a nano-electrospray nozzle 41 to a reaction liquid discharge hole 35 . The operation regarding introduction of reagents is the same as in the third and fourth embodiments. In this embodiment, the reaction liquid is discharged from the nano-electrospray nozzle 41 . Mass spectra of the reaction products within the reaction liquid can be measured by electrospray ionization caused by application of a high voltage.
[0094] The present invention can find wide application in research into organic synthesis and reactions.
[0095] Having thus described our invention with the detail and particularity required by the Patent Laws, what is desired protected by Letters Patent is set forth in the following claims.
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An organic synthesis microreactor mixes fluids in a very narrow space and causes the fluids to react in multiple stages. The reactor consists of an introduction portion and a reaction portion disconnectably connected. The introduction portion introduces reagents from channels and, if necessary, mixes and reacts the reagents. The reaction portion accepts a reagent or reaction liquid from the introduction portion and mixes and reacts the reagent or reaction liquid with other reagent.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This technology relates generally to well drilling. In particular, this technology relates to a shear ram assembly for a blowout preventer (“BOP”) that has wear plates designed to adjust the relative position of ram blocks so that blades of the ram blocks can better shear ductile items, such as wireline, coiled tubings, etc.
[0003] 2. Brief Description of Related Art
[0004] Offshore drilling rigs typically employ a riser to connect the subsea wellhead with the drilling rig. A BOP is located at a lower end of the riser. Land rigs also use BOPs. A BOP is a large assembly having many features for closing around a drill pipe and/or casing in the event that high pressure in the wellbore begins pushing the drilling mud upward. Those features include an annular assembly that seals around the pipe, regardless of the diameter. In addition, the BOP has pipe shear ram assemblies that will shear a drill pipe string or a production tubing string in the event of an emergency.
[0005] Pipe shear ram assemblies typically have two rams, each of which has a blade mounted to it. Pistons move the rams toward each other to shear pipe and other items extending through the BOP. Generally, one blade is located at a higher elevation than the other, and the higher blade slides over the lower blade when the shear rams close. This difference in elevation creates a gap between the blades.
[0006] One problem with known shear ram assemblies is that the blades may not shear everything in the well bore. For example, because there is a gap between the blades, items that are ductile or flexible may simply bend between the blades, rather than cut. Thus, even after the ram blocks are closed and the blades have deployed, ductile items like wiring or flexible tubing may still be intact.
SUMMARY OF THE INVENTION
[0007] Disclosed herein is a pipe shear ram assembly for use in a BOP that in one example includes upper and lower ram blocks having blades. The ram blocks are designed to be positioned on opposite sides of a well bore so that the pipe string, and other more ductile items, such as wiring, pass between the blades of the ram blocks. In the event of an emergency, the ram blocks close by moving toward one another so that the blades pass over one another. As the blades pass over one another, they shear the pipe string and other items in the wellbore, and then seal the wellbore. Generally, as the blades of the upper and lower ram blocks pass over one another, there is a vertical gap between the blades.
[0008] In an example embodiment, the pipe shear ram assembly disclosed herein includes a pair of pipe guide arms that are mounted to the upper ram block and are positioned to enter corresponding recesses in the lower ram block as the ram blocks close. In this example, the pipe shear arms are located in an outboard position relative to the blades and have a wedge-shaped inboard profile. One purpose of the pipe guide arms is to direct piping or other items located on the edges of the wellbore into the path of the blades to be cut.
[0009] Wear plates may be attached to the upper surfaces of the pipe guide arms. The wear plates are positioned so that their top surfaces are higher than the tops of the recesses on the lower ram block. As the rams blocks close, therefore, and the pipe guide arms, along with the wear plates, enter the recesses, the lower ram block is forced to rise so that the recesses can accept the wear plates. As the lower ram block rises, so does the blade attached to the lower ram block. Thus, the gap between the blades of the upper and lower ram blades is reduced. The edges of either the recesses or the wear plates may be chamfered to allow entry of the wear plates into the recesses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will be better understood on reading the following detailed description of nonlimiting embodiments thereof and on examining the accompanying drawings, in which:
[0011] FIG. 1 is a perspective view of the ram blocks of a shear ram assembly in accordance with this disclosure;
[0012] FIG. 1A is a perspective view of the ram blocks of FIG. 1 , with the ram blocks substantially dosed around pipe and ductile items;
[0013] FIG. 2 is a side view of the ram blocks of FIG. 1 ;
[0014] FIG. 3 is a bottom perspective view of the ram blocks of FIG. 1 ;
[0015] FIG. 4 is a front view of the upper ram Hock of FIG. 1 ;
[0016] FIG. 5 is a top view of the upper ram block of FIG. 1 ; and
[0017] FIG. 6 is a perspective view of the ram blocks of FIG. 1 installed within a subsea BOP assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The foregoing aspects, features, and advantages of the present invention will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawings, wherein like reference numerals represent like elements. In describing the preferred embodiments of the invention illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
[0019] Referring to FIG. 1 , shear rams 10 are shown removed from the housing or bonnet (not shown) in which they are located. Shear rams 10 are part of a ram BOP assembly that is part of a stack assembly. In the case of offshore drilling, the stack assembly is located at the lower end of a riser extending downward from a drilling vessel. The lower end of the BOP stack assembly will normally also contain pipe rams, variable bore rams, and a quick disconnect mechanism for disconnecting from the riser in an emergency. When actuated, shear rams 10 will close the through bore and also shear pipe and other items in the well, such as, for example, drill pipe, tubing, casing, or wiring.
[0020] In the example of FIG. 1 , shear rams 10 include a generally planar upper ram block 12 having a lateral surface that defines a face or forward end 14 . A semicircular groove 16 is located on the upper side of upper ram block 12 for receiving a portion of an elastomeric seal. An upper shearing blade 18 mounts to forward end 14 , by any appropriate means, such as, for example, by fasteners 74 . Upper blade 18 has a forward face 20 with an upper edge 22 and a lower edge 24 . For purposes of this disclosure, the term forward, with reference to the ram blocks and associated components, shall mean in a lateral direction from face 20 and away from end 14 . In the example of FIG. 1 , the lower edge 24 extends farther forward from forward end 18 than upper edge 22 , resulting in face 20 inclining relative to forward end 14 . Face 20 is also generally concave or converging, resulting in the center of face 20 between its outboard ends 26 being recessed relative to the more forward portions of face 20 at outboard ends 26 . A variety of different shapes for upper blade 18 may be employed.
[0021] Pipe guide arms 28 are elongate members shown located on the outboard sides of upper ram block forward end 14 and projecting generally forward away from end 14 . In one embodiment; the pipe guide arms 28 are similar to those disclosed in U.S. patent application Ser. No. 13/339,519, which is hereby incorporated herein by reference. Each arm 28 can be formed integrally with upper ram block 12 , or can be otherwise attached, such as by welding or fasteners. Each arm 28 has a vertically oriented inboard side 30 extending forward from a base 32 of each arm 28 . Base 32 is where arm 28 joins forward end 14 . Each arm 28 also has a wedge surface 34 that extends from a junction with a forward end of inboard side 30 to a tip 38 , and an upper surface 36 . The wedge surface 34 depends laterally inward with distance away from the tip 38 . As shown in FIG. 2 , upper surface 36 is spaced at a lower elevation on upper ram block forward end 14 than upper blade lower edge 24 . Upper surface 36 is not located directly under upper blade 18 in this example because inboard side 30 of each arm 28 is approximately the same outboard distance as one of the upper blade outboard ends 26 , as shown, e.g., in FIG. 5 . Also, FIGS. 2 and 5 illustrate that tip 38 extends forwardly more than upper blade 18 from forward end 14 . The junction of inboard side 30 with wedge surface 34 is approximately in vertical alignment with the junction of upper shear blade upper edge 22 and outboard end 26 . One purpose of the arms 28 is to guide a pipe (not shown) and other, more ductile items, in an inboard direction toward the blades. A wear plate 52 is optionally attached to the top surface of each arm 28 , as discussed in greater detail below.
[0022] Referring again to FIG. 1 , a substantially planar lower ram block 40 is illustrated in horizontal alignment with upper ram block 12 . Lower ram block 40 has a forward end 42 that is parallel to forward end 14 of upper ram block 12 . A top seal groove 44 in the upper side of lower ram block 40 receives an elastomeric seal and aligns with seal groove 16 to form a continuous seal when ram blocks 12 , 40 are in abutment with each other. The seal is not necessarily circular. On its upper surface, lower ram block 40 has a sheared pipe end recess 46 for receiving the lower end of well pipe and ductile items after shearing. Sheared pipe end recess 46 has a curved rear wall portion 48 that blends with two straight side wall portions 50 . Other shapes are feasible.
[0023] A lower blade 54 is attached to forward end 42 of lower ram block 40 . Lower blade 54 is at a lower elevation than upper blade 18 , as illustrated in FIG. 2 . Lower blade 54 slides under upper blade 18 when shearing. An upper edge 56 of lower blade 54 is at a slightly lower elevation than lower edge 24 of upper blade 18 . Lower blade 54 has a lower edge 58 that is closer to lower block forward end 42 than the upper edge 56 . A face 60 extends between lower edge 58 and upper edge 56 and is thus inclined relative to forward end 42 . As illustrated in FIG. 2 , in this example, the inclination of lower blade face 60 is the same as the inclination of upper blade face 20 . Lower blade face 60 also recesses or converges to a central area that is closer to lower block forward end 42 that the outboard ends 62 of lower blade 54 , as shown in FIG. 1 . The length of lower blade 54 from one outboard end 62 to the other is the same as the length of upper blade 18 from one outboard end 26 to the other.
[0024] Referring to FIG. 3 , which shows the bottom of shear rams 10 , a recess 64 is located on lower shear block 40 along each outboard side outward and rearward from lower blade outboard ends 62 . Each recess 64 has a space or clearance provided along an outboard side to receive one of the arms 28 when ram blocks 12 , 40 are closed. Each recess 64 is defined by a downward-facing upper side wall 66 and an inboard sidewall 68 , sidewalk 66 and 68 being flat and perpendicular in this example. Each recess 64 is aligned with one of the arms 28 to receive the arm when in the dosed, or sheared position. Each recess 64 has a greater longitudinal length than the length of each arm 28 . Also, upper side wall 66 has a greater width than that of each arm 28 , and inboard side wall 68 has a greater height than the height of each arm 28 . Recess 64 need not be a closed cavity, and in the example shown has no outboard side wall or bottom side wall.
[0025] Referring to FIGS. 1 and 2 , the wear plates 52 may be attached to the arms 28 in any appropriate manner, such as, for example, by welding, adhesive, or mechanical fasteners. In an alternative embodiment, the wear plates 52 may be formed integral with the arms 28 . Each wear plate 52 has a thickness sufficient that the top 70 of each wear plate 52 is slightly higher than the upper side wall 66 of the recesses 64 when the ram blocks 12 , 40 are open. Thus, when the ram blocks 12 , 40 close, the wear plate 52 comes into contact with the upper side wall 66 of the recess 64 and forces the lower ram block 40 to raise. As the lower ram block 40 raises, the lower blade 54 raises relative to the upper blade 18 , so that the vertical gap between the blades 18 , 54 is reduced. A forward edge 72 of the recess 64 is chamfered (as shown in FIGS. 2 and 3 ) to enable the wear plate 52 to slide into recess 64 as the ram blocks 12 , 40 close. Alternatively, the forward edge of the wear plate may be chamfered for the same purpose. In yet another embodiment, the arms 28 may be positioned so that the upper surface 36 of the arms 28 themselves contact the upper side wall 66 of the recess 64 , thereby forcing the ram block 40 to raise. In such an embodiment, wear plates 52 may not be necessary.
[0026] FIG. 1A shows the upper and lower ram blocks 12 , 40 in a substantially closed position around pipe 100 and ductile items 102 , such as, for example, flexible tubing or wiring. Arms 28 , including wear plates 52 , are shown partially engaged with recess 64 . As can be seen, upper and lower blades 18 , 54 have substantially passed over, each other, shearing both the pipe 100 and the ductile items 102 .
[0027] One advantage to the use of wear plates 52 to narrow the gap between the upper and lower blades 18 , 54 is that, as shown in FIG. 1A , the rams 12 , 40 are able to better shear ductile items. For example, in embodiments that do not include the wear plates 52 , the vertical offset between the upper end 56 of the lower blade 54 and the lower end 24 of the upper blade 20 may be great enough that ductile items will not sever, but will merely bend, or flex, in the gap between the blades as the blades close. However, with the wear plates 52 in place, such as shown in FIG. 1A , the gap between the blades is substantially decreased so that even ductile items will be severed, having no room to bend. In one example embodiment, the vertical distance between the upper end 56 of the lower blade 54 and the lower end 24 of the upper blade 20 when the wear plates 52 are not in place is about 0.020 inch. Conversely, in embodiments with the wear plates 52 , the vertical offset between the blades is reduced to a range of less than about 0.020 inch, and in the range of about 0.003 inch or less to about 0.008 inch.
[0028] FIG. 4 is a front view of the upper ram 12 according to an embodiment of the present technology. In particular, FIG. 4 shows wear plates 52 attached to the upper surface 36 of each arm 28 . FIG. 5 similarly shows a top view of the upper ram 12 having wear plates 52 attached to the arms 28 , FIGS. 4 and 5 also show the position of the arms 28 relative to the blade 18 of the upper ram 12 . For example, FIGS. 4 and 5 show that the wear plates 52 are positioned lateral to the upper ram blade 18 so that they do not interfere with the path of the blade 18 as the rams 12 , 40 close. Although the wear plates 52 are shown to be rectangular in shape, they may alternatively be a different shape, as long as the top 70 of each wear plate 52 is configured to contact the upper side wall 66 of the recess 64 and raise the lower ram block 40 relative to the upper ram block 12 , as described above.
[0029] Referring to FIG. 6 , shear rams 10 are shown installed in a typical subsea BOP assembly. The BOP assembly has a BOP stack 76 that includes a frame 78 with a wellhead connector 80 at the lower end for connecting to a subsea wellhead assembly (not shown). Shear rams 10 are normally located above pipe rams, which in this example include pipe rams 82 , 84 , and 86 . Each pipe ram 82 , 84 , and 86 has rams with semi-cylindrical recesses on the mating faces for closing around a different size range of pipe. When closed, shear rams 10 will seal off the bore and if pipe and/or other items are present, will shear the pipe and other items.
[0030] A lower marine riser package (LMRP) 88 connects to the upper end of BOP stack 76 . An annular BOP 90 may be located at the lower end of LMRP 88 . Annular BOP 90 will close around any size of pipe and seal the annulus between the pipe and the side wall of the bore. Annular BOP 90 will also seal fully even if a pipe is not present. A flex joint 92 is located at the upper end of LMRP 88 to allow flexing of a lower end of a riser string 94 connected to flex joint 92 . Choke and kill lines 96 extend from below annular blowout preventer 90 to alongside riser 94 for pumping fluid into the well. In the event of an emergency, LMRP 88 and riser 94 can be detached from BOP stack 76 . Redundant control pods 98 mount LMRP 88 and contain hydraulic and electrical circuitry for controlling movement of the various rams 10 , 82 , 84 , 86 , the annular BOP 90 , and other equipment. Control pods 98 are retrievable from LMRP 88 and are connected to an umbilical (not shown) leading to the drilling vessel at the surface.
[0031] While the technology has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the technology. Furthermore, it is to be understood that the above disclosed embodiments are merely illustrative of the principles and applications of the present technology. Accordingly, numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present technology as defined by the appended claims.
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A shear ram assembly including upper and lower ram blocks having blades positioned on opposing sides of pipe and other, more ductile items, and arranged to close around and shear the pipe and the more ductile items. The shear ram assembly includes pipe guide arms attached to the upper ram block and configured to guide pipe and other items into the path of the blades, and to be received by recesses in the lower ram block. Also included are wear plates mounted on top of the pipe guide arms and positioned to force the lower ram block to rise as the arms enter the recesses, thereby causing the gap between the blades to decrease so that the blades can better shear the more ductile items.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an electric power supply system in which an electric power supply device is contained in a container box, and more particularly to adjustment of the temperature of the electric power supply device.
[0003] 2. Description of the Related Art
[0004] Vehicle-driving electric power supplies (e.g., secondary batteries, or fuel cells) mounted in hybrid electric motor vehicles, electric motor vehicles, fuel cell motor vehicles, etc. need to be cooled since a battery element thereof produces a gas if a proper temperature is exceeded.
[0005] As a cooling technology of this kind, a construction shown in FIG. 5 is disclosed in Japanese Patent Application Publication No. 2003-346924 (JP-A-2003-346924). In this drawing, a battery assembly 101 is contained in a box 102. This box 102 is filled with a cooling liquid. The box 102 is provided with a circulation passageway 103 that causes a cooling liquid to flow into the box 102 and that causes the cooling liquid to flow out from the box 102.
[0006] The circulation passageway 103 is provided with a circulation pump 104 for forcing the cooling liquid to circulate, and with a radiator 105 for cooling the cooling liquid that flows out from the box 102.
[0007] According to the foregoing construction, the cooling water whose temperature has risen due to the cooling of the battery assembly 101 can be cooled by the radiator 105, and can be sent into the box 102 again. Therefore, the battery assembly 101 can be efficiently cooled.
[0008] By increasing the flow rate of the cooling liquid that flows through the box 102, the cooling rate of the battery assembly 101 can be raised. Related technologies are also disclosed in Japanese Patent Application Publication No. 11-238530 (JP-A-11-238530), Japanese Patent No. 2746751, and the Japanese Patent Application Publication No. 2006-127921 (JP-A-2006-127921).
[0009] However, in order to increase the flow rate of the cooling liquid, it is necessary to heighten the pressure of the circulation pump 104, which involves the possibility of a size increase of the pump 104.
[0010] In particular, in battery assemblies for vehicles, since it is necessary to juxtapose a plurality of batteries in a limited space, the intervals between adjacent batteries need to be set small. However, reduced intervals between adjacent batteries cause a decline in the flow rate of the cooling liquid that flows along battery surfaces due to pressure loss, thus giving rise to a possibility of the cooling of the battery assembly 101 becoming insufficient. Therefore, in order to heighten the cooling capability, the pressure of circulation pump 104 needs to be heightened by increasing the size thereof.
SUMMARY OF THE INVENTION
[0011] Accordingly, it is an object of the invention to reduce the size of an electric power supply system that has a heat-exchange fluid that undergoes heat exchange with an electric power supply device.
[0012] A first aspect of the invention is an electric power supply system in which an electric power supply device is contained in a container box, the system being characterized by including: a first heat-exchange fluid that is contained in the container box and that undergoes heat exchange with the electric power supply device; and an introduction device that introduces a second heat-exchange fluid lighter in specific gravity than the first heat-exchange fluid into the first heat-exchange fluid.
[0013] In this aspect, the first heat-exchange fluid may be a liquid, and the second heat-exchange fluid may be a liquid or a gas.
[0014] Besides, the introduction device may include a circulation passageway that returns the second heat-exchange fluid separated from the first heat-exchange fluid by a specific gravity difference into the first heat-exchange fluid.
[0015] Besides, the circulation passageway may be provided with a circulation pump that forces the second heat-exchange fluid to circulate.
[0016] Besides, the electric power supply system may further include a cooling device that cools the second heat-exchange fluid that is introduced into the first heat-exchange fluid via the circulation passageway.
[0017] Besides, the electric power supply system may further include a heating device that heats the second heat-exchange fluid that is introduced into the first heat-exchange fluid via the circulation passageway.
[0018] As a material of the second heat-exchange fluid, air, nitrogen an AT fluid or a silicon oil may be used.
[0019] According to the first aspect of the invention, the first heat-exchange fluid can be caused to flow by causing the second heat-exchange fluid to move in the first heat-exchange fluid due to a specific gravity difference. Therefore, even in the case where the flow rate of the second heat-exchange fluid when it is introduced into the first heat-exchange fluid is set relatively low, decline in the cooling capability can be curved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of a battery assembly;
[0021] FIG. 2 is a sectional view of a battery system;
[0022] FIG. 3 is a plan view of the battery system;
[0023] FIG. 4 is a sectional view of a battery system in accordance with a second embodiment; and
[0024] FIG. 5 is a schematic diagram of a related-art battery system.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] Embodiments of the invention will be described hereinafter with reference to the drawings. A first embodiment of the invention will be described below. FIG. 1 is a perspective view of a battery assembly 1 as an electric power supply device. FIG. 2 is a sectional view of a cylindrical battery of a battery system taken along a direction orthogonal to a lengthwise direction thereof. FIG. 3 is a sectional view of the cylindrical battery of the battery system taken along the lengthwise direction thereof.
[0026] Firstly, an overall construction of the battery system of the first embodiment will be described. In the battery system 4 of the first embodiment, a cooling liquid (first heat-exchange fluid) 51 is contained within a battery box 3 that contains the battery assembly 1 . The battery system 4 also has a circulation passageway 21 for introducing a cooling gas (second heat-exchange fluid) 52 that is lighter in specific gravity than the cooling liquid 51 into the cooling liquid 51 , and for returning the cooling gas 52 separated from the cooling liquid 51 due to the difference in specific gravity into the cooling liquid 51 after cooling the cooling gas 52 via a cooler 22 .
[0027] By causing the cooling gas 52 to float up within the cooling liquid 51 , the cooling liquid 51 can be stirred. This stirring action increases the flow rate of the cooling liquid 51 flowing along the surfaces of the cylindrical batteries 11 , and therefore can raise the cooling rate of the battery assembly 1 .
[0028] Besides, since the cooling gas 52 naturally floats up in the cooling liquid 51 due to the specific gravity difference therebetween, the pressure of a circulation pump (circulation device) 23 for sending the cooling gas 52 into the cooling liquid 51 can be set low. Therefore, the circulation pump 23 can be reduced in size.
[0029] Next, with reference to FIG. 1 , the construction of the battery assembly 1 will be described in detail. The battery assembly 1 is constructed of a plurality of cylindrical batteries 11 extending between a pair of battery folders 12 a , 12 b that are disposed facing each other. Each cylindrical battery 11 is constructed of a lithium-ion battery. Two opposite ends of each cylindrical battery 11 are provided with positive and negative threaded shaft portions 13 , 14 , respectively, each of which has on its outer peripheral surface a thread-grooved portion 13 a , 14 a.
[0030] In each of the battery folders 12 a , 12 b , a plurality of insertion hole portions 121 a , 121 b (the insertion hole portions 121 b are not shown) for inserting the positive and negative threaded shaft portions 13 , 14 of the cylindrical batteries 11 are formed. In a mounted state, the positive and negative threaded shaft portions 13 , 14 are protruded outward from the battery folder 12 through insertion hole portions 11 a , 11 b.
[0031] Adjacent cylindrical batteries 11 are disposed in opposite directions along the direction of an arrow Y (i.e., the orientations of the positive electrode and the negative electrode are set so as to oppose each other in the direction Y). Adjacent cylindrical batteries 11 are serially connected by bus bars 15 .
[0032] The bus bars 15 are inserted on to the positive and negative threaded shaft portions 13 , 14 of the cylindrical batteries 11 . Fastening nuts 16 are placed over the bus bars 15 and are fastened to the positive and negative threaded shaft portions 13 , 14 , so that the cylindrical batteries 11 are fixed to the battery folders 12 .
[0033] Next, with reference to FIGS. 2 and 3 , the construction of the battery system 4 (the electric power supply system) will be described in detail.
[0034] The battery folders 12 a , 12 b of the battery assembly 1 are fixed to a bottom surface of the battery box 3 , and the cylindrical batteries 11 are disposed in a direction parallel to the bottom surface of the battery box 3 (i.e., in a direction in an XY plane).
[0035] The battery box 3 contains the cooling liquid 51 , in which the battery assembly 1 is submerged. Examples of the material of the cooling liquid 51 include a fluorine-based inert liquid that is high in heat conductivity and excellent in insulation characteristic.
[0036] Within the battery box 3 , a space portion 3 a is formed between a ceiling portion of the battery box 3 and the cooling liquid 51 . The circulation passageway 21 , linked to the space portion 3 a in communication, has an extension pipe portion 21 ′ that extends between the battery assembly 1 and the bottom surface of the battery box 3 .
[0037] The extension pipe portion 21 ′ is provided in a region immediately under central portions of the cylindrical batteries 11 in the lengthwise direction, and extends in the direction of the X-axis (the direction orthogonal to the lengthwise direction of the cylindrical battery 11 and parallel to the bottom surface of the battery box 3 ).
[0038] Besides, the extension pipe portion 21 ′ has a plurality of coolant discharge opening portions 21 ′ a that are aligned in the direction of the passageway. The pitch of the coolant discharge opening portions 21 ′ a is set substantially equal to the pitch of the cylindrical batteries 11 in the direction of an arrow X (the direction of the passageway).
[0039] The circulation passageway 21 is provided with the circulation pump 23 for forcing the cooling gas 52 into the extension pipe portion 21 ′, and the cooler (cooling device) 22 for cooling the cooling gas 52 that flows thereinto from the space portion 3 a.
[0040] Examples of the material of the cooling gas 52 include air and nitrogen. Incidentally, the circulation passageway 21 and the circulation pump 23 constitute an introduction device described in the appended claims.
[0041] Next, the cooling operation of the battery system 4 performed to cool the battery assembly 1 will be described.
[0042] When the temperature of the battery assembly 1 heated due to the charging or discharging of electricity exceeds a threshold value (e.g., 60° C.), the circulation pump 23 and the cooler 22 are driven. The battery assembly 1 is provided with a temperature detection sensor. The circulation pump 23 and the cooler 22 are driven on the basis of the temperature information from the temperature detection sensor.
[0043] Due to the cooling of the heated battery assembly 1 , the temperature of the cooling liquid 51 (in particular, of regions around cylindrical batteries 11 , and an upper-side region of the cooling liquid 51 ) is higher than before the circulation pump 23 is started to drive. In other words, after the circulation pump 23 is started to drive, heat transfers efficiently from the heated battery assembly 1 to the cooling liquid 51 .
[0044] The cooling gas 52 sent out into the extension pipe portion 21 ′ due to the pressure action of the circulation pump 23 is discharged from the coolant discharge opening portions 21 ′ a into the cooling liquid 51 , in the form of bubbles.
[0045] Bubbles of the cooling gas 52 float up in the cooling liquid 51 due to the specific gravity difference, and reach the space portion 3 a.
[0046] As the cooling gas 52 floats up in the cooling liquid 51 , heat transfers from the cooling liquid 51 to the cooling gas 52 , so that the cooling liquid 51 is cooled. Therefore, the cooling rate of the battery assembly 1 can be raised.
[0047] Besides, the cooling gas 52 floating up in the cooling liquid 51 stirs the cooling liquid 51 . Therefore, the flow rate of the cooling liquid 51 flowing along the surfaces of the cylindrical batteries 11 increases, so that the cooling rate of the battery assembly 1 will be raised.
[0048] Besides, since the cooling gas 52 floats up in the cooling liquid 51 due to the specific gravity difference, there is no need to heighten the pressure of the circulation pump 23 in order to cause the cooling gas 52 to float up. Therefore, the circulation pump 23 can be reduced in size.
[0049] The cooling gas 52 released into the space portion 3 a flows into the circulation passageway 21 , and is cooled by the cooling action of the cooler 22 , and then is introduced into the cooling liquid 51 again by the circulation pump 23 .
[0050] Thus, in the first embodiment, an end of the circulation passageway 21 is linked to the space portion 3 a of the battery box 3 in communication, and the other end of the circulation passageway 21 extends in a region below the battery assembly 1 within the battery box 3 , and the circulation passageway 21 can be made as a closed system. Therefore, it becomes possible to stop the entrance of an undesired substance from outside the circulation passageway 21 , and to prevent the impairment of the insulation property of the cooling liquid 51 and the cooling gas 52 .
[0051] Modifications of the first embodiment will be described below. Instead of the cooling gas 52 , a cooling liquid lighter in specific gravity than the cooling liquid 51 (e.g., AT fluid or silicon oil) can be used.
[0052] Furthermore, it is also permissible to employ a construction in which cool air is led into the cooling liquid 51 from a radiator that cools the battery box 3 from outside. This allows the cooler 22 to be omitted, and therefore allows a cost reduction.
[0053] Furthermore, although the extension pipe portion 21 ′ is formed by one pipe, a plurality of pipes may be employed. Due to the provision of a plurality of extension pipe portions 21 ′, the cooling gas 52 can be uniformly discharged into the cooling liquid 51 . Therefore, the cooling rate of the battery assembly 1 can be further improved.
[0054] Furthermore, although in the foregoing embodiment, the coolant discharge opening portions 21 ′ a formed in the extension pipe portion 21 ′ are equally pitched, the pitch of the coolant discharge opening portions 21 ′ a may be set in accordance with the temperature distribution in the battery assembly 1 . For example, in the case where there is a high-temperature region in the battery assembly 1 in which the temperature is higher than in other regions, the coolant discharge opening portions 21 ′ a may be formed so that the cooling gas 52 is discharged concentratedly to the high-temperature region.
[0055] Furthermore, since the cooling liquid 51 having higher temperature moves to an upper side, it is also permissible to employ a construction in which the extension pipe portion 21 ′ is disposed at a position higher than in the first embodiment, so that an upper-side portion of the cooling liquid 51 is concentratedly cooled.
[0056] A second embodiment of the invention will be described.
[0057] An overall construction of a battery system of the second embodiment will be described. In the battery system 5 of the second embodiment, a heat-exchange liquid (first heat-exchange fluid) 53 is contained within a battery box 3 that contains a battery assembly 1 . The battery system 5 also has a circulation passageway 21 for introducing a heat-exchange gas (second heat-exchange fluid) 54 that is lighter in specific gravity than the heat-exchange liquid 53 into the heat-exchange liquid 53 , and for returning the heat-exchange gas 54 separated from the heat-exchange liquid 53 due to the difference in specific gravity into the heat-exchange liquid 53 after cooling or heating the heat-exchange gas 54 via a cooler 22 .
[0058] By causing the heated heat-exchange gas 54 to float up in the heat-exchange liquid 53 , the heat-exchange liquid 53 can be stirred. This stirring action increases the flow rate of the heat-exchange liquid 53 flowing along the surfaces of the cylindrical batteries 11 , therefore can quickly raise the temperature of the battery assembly 1 to a proper temperature if the battery assembly 1 has low temperature (e.g., −10° C.).
[0059] Besides, since the heat-exchange gas 54 naturally rises in the heat-exchange liquid 53 due to the specific gravity difference therebetween, the pressure of the circulation pump 23 for sending the heat-exchange gas 54 into the heat-exchange liquid 53 can be set low. Therefore, the circulation pump 23 can be reduced in size.
[0060] In the case where the cooled heat-exchange gas 54 is introduced into the heat-exchange liquid 53 , substantially the same effect as in the first embodiment can be achieved. In addition, as the heat-exchange liquid 53 , the same material as used for the cooling liquid 51 in the first embodiment can be used.
[0061] Besides, as the heat-exchange gas 54 , the same material as used for the cooling gas 52 in the first embodiment may be used, and may be a liquid, for example, an AT fluid, a silicon oil, etc., that is lighter in specific gravity than a fluorine-based inert liquid.
[0062] Next, with reference to FIG. 4 , the construction of the battery system 5 of the second embodiment will be described in detail. FIG. 4 is a sectional view of the battery system 5 of the second embodiment. The same component elements as those in the first embodiment will be suffixed with the same reference characters, and the detailed description thereof will be omitted.
[0063] The circulation passageway 21 linked to a space portion 3 a in communication is provided with the cooler (cooling device) 22 , a heater (heating device) 24 and the circulation pump 23 . The cooler 22 cools the heat-exchange gas 54 that flows in from the space portion 3 a . The heater 24 heats the heat-exchange gas 54 that flows in from the space portion 3 a.
[0064] The battery assembly 1 is provided with a temperature detection sensor (not shown). The cooler 22 , the heater 24 and the circulation pump 23 are driven on the basis of the temperature information from the temperature detection sensor. Incidentally, the cooler 22 , the heater 24 and the circulation pump 23 are driven by a control circuit (not shown).
[0065] Next, the cooling operation of the battery system 5 performed to cool the battery assembly 1 will be described. If the control circuit determines that the temperature of the battery assembly 1 is lower than the proper temperature (e.g., −10° C. to 60° C.) on the basis of the temperature information from the temperature detection sensor, the control circuit drives the heater 24 and the circulation pump 23 .
[0066] The heat-exchange gas 54 sent out into the extension pipe portion 21 ′ due to the pressure action of the circulation pump 23 is discharged from the heat-exchange discharge opening portions 21 ′ b into the heat-exchange liquid 53 in the form of bubbles.
[0067] Bubbles of the heat-exchange gas 54 float up in the heat-exchange liquid 53 due to the specific gravity difference, and reach the space portion 3 a.
[0068] As the heat-exchange gas 54 floats up in the heat-exchange liquid 53 , heat transfers from the heat-exchange gas 54 to the heat-exchange liquid 53 , so that the heat-exchange liquid 53 is heated. Therefore, the temperature of the battery assembly 1 can be quickly raised to a proper temperature.
[0069] Besides, the heat-exchange gas 54 floating up in the heat-exchange liquid 53 stirs the heat-exchange liquid 53 . Therefore, the flow rate of the heat-exchange liquid 53 flowing along the surfaces of the cylindrical batteries 11 increases, so that the cooling rate of the battery assembly 1 will be raised.
[0070] Besides, since the heat-exchange gas 54 floats up in the heat-exchange liquid 53 due to the specific gravity difference, there is no need to heighten the pressure of the circulation pump 23 in order to cause the heat-exchange gas 54 to float up. Therefore, the circulation pump 23 can be reduced in size.
[0071] The heat-exchange gas 54 released into the space portion 3 a flows into the circulation passageway 21 , and is heated by the heating action of the heater 24 , and then is introduced into the heat-exchange liquid 53 by the circulation pump 23 again.
[0072] Thus, in the second embodiment, an end of the circulation passageway 21 is linked to the space portion 3 a of the battery box 3 in communication, and the other end of the circulation passageway 21 extends in a region below the battery assembly 1 within the battery box 3 , and the circulation passageway 21 can be made as a closed system. Therefore, it becomes possible to stop the entrance of an undesired substance from outside the circulation passageway 21 into the heat-exchange liquid 53 and the heat-exchange gas 54 , and to prevent the impairment of the insulation property of the heat-exchange liquid 53 and the heat-exchange gas 54 .
[0073] If the temperature of the battery assembly 1 is beyond the proper temperature, the cooler 22 and the circulation pump 23 are driven to quickly cool the battery assembly 1 as in the first embodiment.
[0074] Although in the second embodiment, the heat-exchange gas 54 cooled by the heat-exchange liquid 53 is heated by the heater 24 , it is also permissible to employ a construction in which, for example, a portion of the exhaust gas from the vehicle or a portion of hot air jetted from the airconditioner provided in the cabin is introduced into the heat-exchange liquid 53 . This allows the heater 24 to be omitted, and therefore allows a cost reduction of the battery system 5 .
[0075] Although in the foregoing first and second embodiments, the cylindrical batteries 11 are lithium-ion batteries, it is also permissible to use other types of secondary batteries (electric power supply device), capacitors (electric power supply device), and a fuel cell (electric power supply device).
[0076] These electric power supply devices can be used as an electric power supply for driving a motor in, for example, in the electric motor vehicles (EV), hybrid electric motor vehicles (HEV), and fuel cell vehicles (FCV).
[0077] While the invention has been described with reference to the example embodiment thereof, it is to be understood that the invention is not limited to the example embodiment and construction. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the example embodiment are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the sprit and scope of the invention.
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A battery system having a cooling liquid that undergoes heat exchange with a battery assembly is reduced in size. The battery system in which a battery assembly is contained in a battery box is characterized by including the cooling liquid that is contained in the battery box and that undergoes heat exchange with the battery assembly, and a circulation passageway and a circulation pump that introduce a cooling gas lighter in specific gravity than the cooling liquid into the cooling liquid. The cooling gas floating up in the cooling liquid stirs the cooling liquid. This stirring action increases the flow rate of the cooling liquid, and therefore makes it possible to obtain high cooling capability even in a construction that employs a small-size circulation pump.
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BACKGROUND OF THE INVENTION
The United States Government may have rights in this patent because of relevant developmental work supported by research grant no. DMB-8701379 from the NSF and grant no. GM24365 from the NIH.
Electrophoresis refers to the migration of charged solutes or particles in an electric field. Electrophoresis for macromolecule fractionation has been a valuable separation and quantitation technique in both the clinical and investigative laboratory. Electrophoresis can separate each type of molecule by zone. The zones are usually revealed by staining. Each zone appears as a visible band. One technique for electrophoretic separation is to pass a current through a buffer contained in a solid support medium. The support medium is typically constructed of cellulose, paper, cellulose acetate, starch gel, cross-linked dextran, polyacrylamide gel, or agarose gel. Molecules carrying an electric charge will move either to the cathode or to the anode of the electrophoretic system, depending on the nature of the charge of the molecule. The rate of movement of individual molecules is determined by: (1) net electric charge per surface area of the molecule; (2) size and shape of the molecule; (3) electric field strength; (4) nature and concentration of the supporting medium; and (5) the temperature of operation. For example, the speed of migration of a molecule increases as its average electrical surface charge density increases in magnitude (Shaw, D.J. (1969). Electrophoresis, Academic Press, London) and decreases as the molecules' motion is increasingly resisted by the support medium (reviewed in: Serwer, P. (1987). Biophysical characterization by agarose gel electrophoresis. In: New Directions in Electrophoretic Methods (Jorgenson, J.W. and Phillips, M., Ed.), Amer. Chem. Soc., Washington, D.C., pp. 158-166.). After electrophoresis, the current is terminated and the support medium is removed from the electrophoresis apparatus. The support medium may then be placed in a dye solution to stain the bands of solute macromolecules which have migrated into the support medium. The excess stain is then rinsed away. Quantitation of the solute macromolecule bands is generally achieved by using a densitometer. This instrument measures either the intensity of the light reflected from the dyed fraction (stained bands of solute macromolecules) or the amount of light transmitted through the support medium.
The basic method of electrophoresis, as set forth above, has been modified by investigators to suit particular purposes. For example, there are now specialized electrophoretic techniques, e.g., moving boundary electrophoresis, zone electrophoresis, immunoelectrophoresis, and isoelectric focusing electrophoresis. Each of these techniques is specifically designed to facilitate a desired type of separation. The present invention is directed toward the technique of using a porous support medium for the selective retardation during, for example, diffusion or electrophoretic migration, of solute macromolecules.
The capacity of certain porous support media to cause selective retardation based on either size or shape is well known. Such sieving media are used to separate biological macromolecules, i.e., proteins, DNA, RNA polysaccharides and the like. Such sieving media are characterized by the presence of a microporous structure which exerts a selective action on the migrating solute macromolecules, restricting passage of larger particles more than that of the smaller particles. Thus, the utility of sieving lies in the capacity of the sieving medium (support medium) to distinguish between molecules of different sizes and shapes. The porous support medium (sieving medium) is chosen to have a pore size appropriate for accomplishing the desired separation.
During electrophoresis, separations based on sieving have been achieved by using several sieving media including starch gel, cross-linked dextran, polyacrylamide gel, porous glass, agar gel, and agarose gel. It is known in the art that agarose forms gels useful in electrophoresis. Agarose gel electrophoresis has been successfully applied to the analysis of numerous biological macromolecules, for example, serum proteins, hemoglobin, lactate dehydrogenases, isoenzymes, lipoproteins, polynucleotides and the like. The versatility and convenience of agarose gels has made agarose the support medium of choice in some clinical and investigative laboratory settings.
The utility of agarose gels for either electrophoresis or other molecular sieving techniques, depends in part on the pore sizes achievable. According to U.S. Pat. No. 3,527,712, the pore size of agarose gel is dependent on the concentration of agarose in the gel. U.S. Pat. No. 3,527,712, states that gels with agarose concentrations greater than 5% have a porosity roughly comparable to that provided by cross-linked dextrans or polyacrylamide gels, in that while separation of smaller molecules can be achieved, it is not possible to effect separation between molecules of molecular weights greater than 200,000. However, it is known in the art that as the concentration of the agarose is decreased, the effective pore size of the gel is increased, and depending on a particular concentration of agarose, it becomes possible to effect molecular sorting of molecules having molecular weights greater than 200,000. The effective pore radius of agarose gels can be varied from 5 nm to 1-2 um (micrometers). The smaller radii are useful for procedures such as:
1. Sieving monomeric proteins (Easom, R.A., DeBuysere, M.S., Olson, M.S. and Serwer, P. [1989]; and
2. Size determination of multienzyme complexes using two-dimensional agarose gel electrophoresis (Proteins: Structure, Function and Genetics, 5, 224-232).
Gels with the larger pore radii are useful for procedures such as:
1. Sieving intact bacterial cells (Serwer, P., Moreno, E.T. and Griess, G.A. [1988];and
2. Agarose gel electrophoresis of particles larger than 100 nm: Fractionation of intact Escherichia coli. (Electrophoresis '88, Schafer-Nielsen, C., Ed. pp. 216-222).
This ability to control the pore size of agarose gels is greater than anything known with gels of other compounds.
Typically, molecular sieving media, as discussed above, have a uniform mean pore size throughout. However, it becomes apparent that a sieving medium having a plurality of pore sizes, arranged in a gradient, could effectively: (a) fractionate particles with a greater range of sizes, (b) sharpen the bands formed by particles of unique size, and (c) cause effective cessation of motion based on pore size. Thus, other investigators in the art have attempted to manufacture sieving media having a gradient of pore size, for example, polyacrylamide and agarose gels.
With respect to polyacrylamide gels, a pore size gradient was created by pouring a concentration gradient of acrylamide before polymerization and subsequent gelation of the acrylamide (Rodbard, D., Kapadia, G. and Chrambach, A. (1971). Pore gradient electrophoresis. Anal. Biochem. 40, 135-157. Bothe, D., Simonis, M., and von Dorhen, H. (1985), A sodium dodecyl sulfate-gradient gel electrophoresis system that separates polypeptides in the molecular weight range of 1500 to 100,000. Anal. Biochem. 151, 49-54. Fawcett, J.S., Sullivan, J.V. and Chrambach, A. (1989). Toward a steady-state pore limit electrophoresis dimension for native proteins in two-dimensional polyacrylamide gel electrophoresis. Electrophoresis 10, 182-185.). The pore size decreases as the concentration of gel increases. The pore size gradient has the largest pores at the origin of electrophoresis. This procedure usually requires about an hour per gradient pouring. In addition, reproducing defect-free gradients is difficult, in part because of the difficulty in reproducing pouring conditions. Because agarose must be maintained at 50 to 60° C., the concentration gradients are more difficult to pour than concentration gradients of other gel-forming compounds. However, the many advantages and uses of agarose gels having a gradient of pore size have provided a strong incentive to develop new and
x improved methods for producing them. For e ample, the use of agarose gels having a pore size gradient is desirable for: (a) increasing the sharpness of bands, (b) extending the range of molecules separated; and (c) performing steric exclusion electrophoresis by pore size exclusion.
Waki et al. (Biopolymers 21 1909-1926, 1982) have studied agarose gel structure by electron microscopy of freeze-fractured surfaces and noted that gels set in the presence of salt have larger interfiber spaces and greater pore size. This larger pore size was confirmed by electrophoretic measurements of relative migration rates for plasmid DNA molecules of varying conformations. Peats et al. (Biophysical Journal 49 91a, 1986) reported finding that agarose gelled in the presence of borate had an increase in sieving power.
Accordingly it would be advantageous to develop a agarose gel having a gradient of pore size without the expense and problems typically associated with prior attempts based on agarose concentration gradients. Moreover, it would be advantageous to produce an agarose gel having a gradient pore size which could be simply and inexpensively manufactured for use in clinical and investigative laboratories. For maintaining uniformity of thickness during post-electrophoresis drying, a pore gradient formed at uniform gel concentration is superior to a pore gradient formed by varying the gel concentration. Drying is performed for autoradiography and fluorography. Thus, the methods of the present invention are particularly directed to agarose gels having a uniform agarose concentration and a pore-size gradient, pore size decreasing with increasing distance from the origin of electrophoresis, as well as methods for producing such agarose gels. The present inventors have determined that the pore size of an agarose gel may be effectively controlled by varying the composition of the buffer during gelation. Thus, unlike the prior art in this field, the present invention demonstrates production of an agarose gel having a pore size gradient, not by varying the concentration of the agarose in the gel, but by varying, during gelation, the buffer (or non-buffering ion) composition in different regions of the gel.
SUMMARY OF THE INVENTION
The present invention demonstrates herein that the pore size of an agarose gel can be directed by controlling the buffer or salt concentration of an agarose solution during gelation.
An important aspect of the present invention is directed toward a method for controlling the pore size of an agarose gel. In one embodiment, this method includes the steps of:
(a) preparing aqueous solutions of agarose having different salt and/or buffer concentrations; and
(b) gelling said solutions in proximity to each other.
The present invention is also directed to agarose gels which may have a uniform agarose concentration and a pore size gradient and processes for producing such agarose gels. Both vertical and horizontal gel molds may be utilized in separate aspects of the invention.
In a vertical gel mold, a preferred process comprises the steps of:
(a) preparing a plurality of buffered aqueous agarose solutions, each solution including an identical concentration of agarose and a different molar concentration of a buffer or salt, said molar concentration of said buffer or salt determining the pore size of the gelled agarose; and
(b) adding, sequentially, in order of decreasing buffer or salt molar concentration, the aqueous agarose solutions to said vertical gel mold prior to gelation. It should be noted that the agarose concentrations may be the same but need not be to form a pore gradient.
In a horizontal gel mold, a preferred process comprises the steps of:
(a) dividing said horizontal gel mold into a first and second compartment by dividing means;
(b) preparing a first aqueous agarose solution having a first buffer or salt concentration;
(c) pouring this aqueous agarose solution into the first compartment;
(d) removing, said dividing means after gelation of the first aqueous agarose solution.
(e) preparing a second aqueous agarose solution, this solution having a second buffer or salt concentrations being lower than the first;
(f) pouring said second aqueous agarose solution into the second compartment;
(g) keeping the second agarose gel above the gelation temperature until diffusion of salt or buffer has formed a salt or buffer gradient; and
(h) lowering temperature to allow gelation of the second solution.
The agarose gels of the present invention are useful in separating, by means of sieving (hydrodynamic or steric), molecules by size, shape or molecular weight. Typically, these molecules are molecules such as: endo-nuclease-resisted DNA and RNA fragments, proteins, multimolecular protein complexes and the like. Several techniques based on sieving may be utilized in conjunction with the agarose gels of the present invention, for example, gel electrophoresis, and molecular sieve chromatography.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a horizontal gel mold in which the first and second compartments are identified; the first compartment for containing a first aqueous agarose solution; the second compartment for containing a second aqueous agarose solution.
FIG. 2 illustrates the diffusion of the buffer throughout the aqueous non-buffered agarose solution. FIG. 2 also illustrates the resultant gradient of buffer concentration.
FIG. 3 is a photograph of an agarose gel having a gradient of pore size after horizontal electrophoresis of latex spheres was completed. The latex spheres electrophoresed moved from top to bottom. The buffer concentration during gelation increased from left to right.
FIG. 4 is a graphic representation of increasing pore size (Pe) as the concentration of buffer increases. These sizes were determined by the procedure of G. A. Griess, 28, 1475-1484.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a process for producing novel agarose gels which may have a uniform concentration of agarose and do have a pore size gradient. The agarose gels of the present invention are useful for several sieving-based techniques, i.e., electrophoresis, chromatography and the like. The agarose gels of the present invention may be used, for example, to detect, fractionate, concentrate, quantify and qualify samples, specimens or complex proteins of biological or commercial origin. Such studies include those directed to complex mixtures, including: lesions of atherosclerosis; sera; cellular extracts; nuclear extracts (chromosomal DNAs). The sensitivity of detection of such isolates beyond that achievable by prior art techniques represents a significant advantage of the present invention.
One embodiment of the invention is directed toward a process for controlling the pore size of an agarose gel. This process includes several steps. One step of the inventive process is the preparation of an aqueous solution of agarose. According to one preferred embodiment, from about 0.5 to about 5% agarose is boiled in water.
Another step in the inventive process is adding to the aqueous agarose solution prior to gelation a sufficient amount of either a buffer or a non-buffering salt to achieve a predetermined molar concentration. One may dissolve the agarose in a pre-selected buffer or salt solution if desired. It has been determined that the concentration of the buffer or salt in the agarose solution determines the pore size of the gelled agarose. According to one preferred embodiment, the concentration of salt and/or buffer is from about 0.00 M to about 0.5 M. However, most preferably, the molar concentration is from about 0.01 M to about 0.20 M. The buffer or salt of the present invention is preferably at least one selected from the group consisting of potassium dihydrogen phosphate, disodium hydrogen phosphate, tris(hydroxymethyl)aminomethane, sodium bicarbonate, sodium acetate, and sodium tetraborate although many other buffers may be used. However, it should be noted that any buffer which disassociates at a pH of from about 6.0 to about 8.0 and does not precipitate with agarose may be utilized in the practice of the present invention. Examples of salts known to be usable include sodium chloride potassium chloride and calcium chloride but many other salts may be utilized.
It has been determined that as the molar concentration of the buffer increases, the pore size progressively increases. This phenomenon continues, until, at one point, a high enough buffer concentration will either not effect pore size or will actually begin decreasing pore size. According to one experiment conducted by the present inventors, pore size progressively increased as the concentration of a phosphate buffer (pH 7.4) increased until it reached 0.15 M. It was also noted that as phosphate buffer concentrations increased above 0.15 M, pore size decreased. This phenomenon is also demonstrated in FIG. 4. FIG. 4 shows that as the concentration of salt (NaCl) decreased below 0.15 M, the agarose gel pore size decreased.
Another embodiment of the present invention is directed to a process for producing an agarose gel in a vertical gel mold having a uniform agarose concentration and a pore size gradient. The process includes several steps. One step is preparing a plurality of buffered aqueous agarose solutions. Each of the solutions includes an identical concentration of agarose and a different molar concentration of buffer.
According to one preferred embodiment, a plurality of buffered agarose solutions is prepared by a process including the steps of: (a) preparing an aqueous agarose solution; (b) subdividing the aqueous agarose solution into a plurality of containers; (c) adding, prior to gelation, a different molar concentration of a buffer to each container of aqueous agarose solution. Any desired number of buffered aqueous agarose solutions may be prepared in this manner.
The concentrations of agarose included in the buffered aqueous agarose solutions is preferably from about 0.5% to about 5% (w/v), and most preferably from about 1% to about 3% (w/v). The concentration of buffer and/or salt added to each aqueous solution of agarose may generally be from about 0.000 M to about 0.5 M, and most preferably from about 0.01 M to about 0.05 M.
According to this embodiment, another step in the inventive process is adding, sequentially, in order of decreasing buffer or salt concentration, the agarose aqueous solutions to a vertical gel mold prior to gelation. According to one preferred embodiment, each buffered aqueous agarose solution is added only after the previously added solution has gelled in the vertical gel mold. When adding in order of decreasing salt or buffer concentration, the ultimate gel pore size decreases as buffer concentration decreases so that the gels would be eventually inverted for sample application. The differences among the specific gravities of the agarose solutions must be sufficient to prevent convective disturbance.
The pore size gradiated agarose gels of the present invention are useful for several sieving-based techniques. An agarose gel having a gradient of pore size (Pe or PE) may be utilized in a technique to separate molecules by molecular weight. Accordingly, molecules of various molecular weights would be added to the agarose gel at the site of greatest pore size. The molecules are driven through the agarose gel. Ultimately, the differing molecules are restricted by the pore size of the gel. Once the motion of the molecules through the agarose gel is complete, or after a predetermined amount of time, separation of the molecules is concluded.
Another embodiment of the present invention is directed to a process for producing an agarose gel having a uniform agarose concentration and a pore size gradient in a horizontal gel mold. The process includes several steps. One step is dividing the horizontal gel mold into a first and second compartment. This may be accomplished in any manner which substantially divides the horizontal gel mold into at least two compartments. Most preferably, the compartment which will later contain the agarose solution at a higher buffer concentration is the smaller of the two compartments.
According to a preferred aspect of the present invention, an agarose gel of the present invention having a pore size gradient is utilized for an electrophoresis technique. After formation of a gel with a pore size gradient by gelation at varying buffer/salt concentrations, the buffer and/or salt may preferably be removed and replaced by a selected buffer appropriate for the electrophoresis process. Accordingly, particles of various weights, sizes, charges and/or shapes are added to the agarose gel at a site of greatest pore size and electrophoresis is then performed. During electrophoresis, the molecules migrate through the gel, progressively slowing as pore size decreases. The pore size gradient thus sharpens the bands formed by particles that have given characteristics of size, charge and shape. It also increases the range of particles that can be separated on one gel. The particles can be any charged particle of appropriate size, including protein, DNA and RNA.
In this aspect of the present invention a non-buffered aqueous agarose solution may be used in combination with a buffered agarose solution. The non-buffered aqueous agarose solution is prepared in substantially the same manner as set forth above in previous embodiments of the present invention. The non-buffered aqueous agarose solution is then poured into the remaining compartment of the horizontal gel mold prior to gelation. It should be noted that the dividing means may be left in place until the non-buffered aqueous agarose solution has been added and then removed. Once the non-buffered aqueous agarose solution is in contact with the gelled buffered aqueous agarose gel, the buffer will diffuse throughout the non-buffered aqueous agarose solution, and upon gelation the non-buffered aqueous agarose solution will contain a buffer concentration gradient. The buffer concentration decreases as the distance from the buffered aqueous agarose gel increases. Thus, upon gelation of the non-buffered aqueous agarose solution, pore size will decrease as the distance from the buffered-aqueous gel increases. Accordingly, a gradient of pore size is created.
The following example is presented to describe preferred embodiments and utilities of the present invention and is not meant to limit the present invention unless otherwise stated in the claims appended hereto.
EXAMPLE
A horizontal pore gradient gel that has the same concentration of agarose throughout was prepared by the following procedure:
A strip of agarose was cast in comparatively high ionic strength buffer, 0.5 M NaCl (salt) in one compartment (high salt) of a horizontal electrophoresis apparatus strip was restricted in width by a PLEXIGLAS bar placed in the gel bed to divide the high salt from the no salt compartment.
The bar was removed after the buffered agarose had gelled. A sample well-forming comb was placed in the gel bed, as is conventionally done. An aqueous agarose solution was prepared. The aqueous agarose solution included 1% agarose, and was prepared in water having a temperature of 60° C. The aqueous agarose solution was then, prior to gelation, poured into the remaining compartment (no salt) of the gel bed. At one end, the molten NaCl. During its gelation, the molten unbuffered aqueous agarose developed a horizontal NaCl gradient because of the diffusion of NaCl from the gelled agarose. When the molten aqueous agarose solution gelled, the NaCl gradient produce a Pe (pore size) gradient (data in FIG. 4). FIG. 4 shows how (Pe) decreased as buffer concentration decreased below 0.15 M. It should alwo be noted that pore size begins to decrease above about 0.15 M. This phenomenon could lead to pore size gradients formed with pore sizes decreasing as salt or buffer concentrations increase above about 0.15 M. agarose (LE 62677) by the following procedure. Agarose in 0.4 M NaCl was placed in lane 1 and allowed to gel. The rest of the mold was then filled with 1% agarose free of buffer and salt. Gelation of the latter agarose was extended for about one hour by exposure to a heat lamp, during which salt from the first gel diffused across. A set of sample wells was formed across the gradient from right to left with a comb at one end of the gel bed (See FIG. 3). Negatively charged latex spheres (11 micron diameter) were loaded in the sample wells (the wells all had the same sample of latex spheres). The gel was soaked overnight in 0.0253 M sodium phosphate, pH 7.4, 0.0013 M MgCl 2 and 0.5% TRITON X-100 before use. The TRITON X-100 is a non-ionic detergent present to prevent sticking of the latex spheres to the gel. Electrophoresis was performed in 0.025 M sodium phosphate, pH 7.4, 0.001 M MgCl 2 , 0.5% TRITON X-100. After electrophoresis, the latex spheres were detected by their light scattering and found to migrate a distance that decreased with distance from the position of the original contact with the NaClcontaining gel (FIG. 3). This contact is indicated in FIG. 3 as contact line (1→>). The spheres migrated from top to bottom. In FIG. 3 the spheres nearest the line of contract, migrated the furthest, as predicted from the expected finding of the highest Pe nearest the line of contact. That is, during gelation the highest salt concentration was located near the line of contact. This experiment demonstrates validity of the present invention. It should be noted, however, that in most instances the direction of electrophoresis would be along the gradient rather than across it as shown here.
The references cited in the above text are incorporated in pertinent part herein for the reasons cited.
Changes may be made in the components and assemblies described herein or in the steps or the sequence of steps of the method described herein without departing from the concept and scope of the invention as defined in the following claims.
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Provided are agarose gels and processes for producing agarose gels having a uniform concentration of agarose and a pore size gradient. These gels are prepared by allowing gelation in a salt or buffer gradient. The agarose gels are suitable for the purposes of sieving based electrophoretic separations or other sieving-based separations, such as, chromatography.
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BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates to a system for timing the opening and closing of switching arrangements used in high power electrical transmission systems. More specifically, the invention relates to such a system which takes into account conditions of temperature surrounding the switching arrangements as well as the mechanical displacement time of the electrical contacts of the switching arrangements.
2. Description of Prior Art
Switching arrangements, for example, circuit breakers, are used in electrical transmission lines or distribution lines to redirect power, or are used to connect the lines to reactive elements to correct power factor. Such breakers, because of the large amounts of power they must handle, are very large (approximately the size of a small house on each phase) and are very costly.
Associated with such breakers are resistive elements, which are connected in parallel to the breakers just before the opening and closing of the breakers, to absorb the "overvoltages" which accompany the opening and closing of the breakers to thereby protect the switching elements of the breakers as well as the reactive elements. The resistive elements are also large and expensive.
It is a well known fact in the art that the temperature surrounding the breaker has an effect on the speed of operation of the breakers. Generally speaking, the lower the temperature, the greater amount of time needed to open or close the breakers and vice-versa.
SUMMARY OF INVENTION
It is an object of the invention to provide a system for timing the opening and closing of switching arrangements which obviates the needs for resistive elements.
It is a more specific object of the invention to provide such a timing system which will open and close the breakers at such a time in the cycle of the transmitted signal whereby to minimize the overvoltage due to the opening and closing of the breaker.
In accordance with a particular embodiment of the invention there is provided a system for timing the opening and closing of a switching arrangement used in high power electrical transmission systems which transmit at least one phase of a power signal having a sinusoidal variation, comprising:
switch means for providing an OPEN/CLOSE initiating signal for initiating the opening/closing of said switch arrangement;
zero crossing detector means for detecting zero crossings of said power signal and for providing a zero crossing signal upon detection of a zero crossing;
processor means;
controller means;
analog-to-digital converter means;
temperature sensing means for sensing the temperature of said switching arrangement;
first conductor means connecting said power signal to a first input of said analog-to-digital converter means when said switching arrangement is open;
second conductor means connecting said power signal to a second input of said analog-to-digital converter means when said switching arrangement is closed;
third conductor means connecting said power signal to a first input of said zero crossing detector when said switching arrangement is open;
fourth conductor means connecting said power signal to a second input of said zero crossing detector means when said switching arrangement is closed;
fifth conductor means connecting said temperature sensing means to a third input of said analog-to-digital converter means;
said analog-to-digital converter means being connected to a first input of said processor means;
said zero crossing detector being connected to a second input of said processor means;
said switch means being connected to a third input of said processor;
said processor means being connected to an input of said controller means;
whereby, upon detection of an initiating signal, said processor, after receiving a zero crossing signal, causes said controller to carry out a series of predetermined steps to open/close said switching arrangement.
From a different aspect and in accordance with a particular embodiment of the invention there is provided a method for timing the opening and closing of a switching arrangement used in high power electrical transmission systems which transmit at least one phase of a power signal having a sinusoidal variation, comprising:
providing an OPEN/CLOSE initiating signal to a processor to initiate the opening/closing of said switching arrangement;
detecting a zero crossing of said power signal and providing a zero crossing signal to said processor upon detection of said zero crossing;
said processor, upon detection of a first zero crossing signal after an opening/closing signal, causing a controller to carry out a series of predetermined steps.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be better understood by an examination of the following description, together with the accompanying drawings, in which:
FIG. 1 is a block diagram of the system;
FIG. 2A illustrates the number of integral cycles in which the complete opening procedure is performed in the preferred embodiment;
FIG. 2B illustrates the first phase power signal;
FIG. 2C illustrates the initiating signal;
FIG. 2D illustrates the phase indication signal according to the preferred embodiment;
FIG. 2E illustrates the breaker activation signal according to the preferred embodiment;
FIG. 2F illustrates the state of the breaker; and
FIGS. 3A through 3F correspond to FIGS. 2A through 2F for the equivalent sequence of events during closing of the breaker according to the preferred embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, a circuit breaker, illustrated schematically at 1, and having coil means represented schematically at 1A and electrode means represented schematically at 1B and 1C, is connected between the three phases, A, B and C, of transmitted power, and a reactive element illustrated schematically at 3. When the breaker is opened, the measured tension of one of the phases, in the illustrated embodiment phase A, is connected to an analog-to-digital (A/D) converter 5 by conductor D. The magnitude, frequency and other characteristics of the phase A signal are translated from an analog value to a digital value in A/D converter 5, and the digital signal is then fed to a microprocessor 7. In addition, the phase A signal is fed to zero detector 9 wherein the zero crossings of the phase A signal are detected. When a phase A zero crossing is detected, a pulse or other indication is fed to the microprocessor 7. As will be apparent, the zero crossings of phase A are used for synchronization purposes.
A thermometer, illustrated schematically at 10, measures the temperature surrounding the circuit breaker. An electrical analog of the temperature is then fed to the A/D (analog to digital) converter 5, and the digital conversion of the temperature is also fed to the microprocessor 7.
When the breaker is closed, phase A, B and C signals are fed along conductors X, Y and Z, and the phases A, B and C measured currents are fed to the A/D converter 5 as shown in FIG. 1. Once again, the analog signals are converted to digital signals and the digital signals are fed to the microprocessor 7. The signal of the phase A is also fed to the zero detector 9, and, once again, a pulse or other indication is fed to the processor 7 when a zero crossing is detected.
The currents on phases A, B and C are monitored in order to detect any restrike that might occur when the circuit breaker opens or high inrush current when the circuit breaker closes.
Alarm signals are generated when a restrike or a high inrush current occurs on any of the three phases.
The opening or closing of the breaker is initiated by ON/OFF switch 11. The signal from the ON/OFF switch is, once again, fed to the microprocessor 7.
The output of the microprocessor 7 is fed to a controller 13 which will either open or close the breakers, associated with the A, B or C phases under the control of the microprocessor 7, by carrying out a series of predetermined, timed, steps as described below. If the system cannot operate to open or close the breaker under the control of the controller 13, an emergency override 15 is provided to open or close the breakers, once again, under control of the microprocessor 7.
A keyboard 17 is provided for the purpose of programming the microprocessor 7, as is well known in the art, and a display unit 19 is provided for examining various parameters and alarm signals, once again, as is well known in the art.
To understand the operation of the system, reference is had to FIG. 2, for an understanding of the opening operation, and to FIG. 3 for an understanding of the closing operation. Generally, the system is either in a waiting mode, that is, when an opening or closing has not been commanded, or an active mode in which the breaker is either being opened or closed. In the waiting mode, temperature readings are taken at predetermined intervals by the thermometer 10, and an electrical analog of the temperature is provided to the A/D converter 5. The digital representation of the temperature is then provided to the processor 7.
At the same time, during the waiting mode, the functionality of the system is verified by means well known in the art. Parameters are also calculated taking into account the changing temperature.
Turning now to FIG. 2, in accordance with the invention, the complete opening procedure, t o , is performed during an integral number of cycles, i.e. in a time n (t cycle ), where t cycle =period of a cycle and n=a predetermined integer. As illustrated in FIG. 2A, the number of integral cycles in which the complete opening procedure is performed in one particular embodiment is 3. As illustrated in FIG. 2B, the transmitted signal is a sinusoid. In North America, the frequency of the transmitted signal is, of course, 60 Hz so that t cycle =16.67 msec..
The signal for opening the breaker (separating the electrodes of the breakers from each other: the signal is initiated by pressing the ON button in the switch 11 in FIG. 1) is given at the beginning of a period t co . The signal t co is illustrated in FIG. 2C and is the time duration during which the opening signal remains high. As can be seen in FIG. 2C, t co remains high during the entire opening procedure and stays open until a closing signal is initiated.
The high level at the onset of t co is fed to the microprocessor 7 and the microprocessor 7 then seeks a zero of the sinusoid at the first zero crossing after the initiation of t co . As seen in FIGS. 2B and 2D, this occurs at the beginning of the period t y in FIG. 2D.
It is only after the waiting period t y , that is, at the beginning of the period t mo , (see FIG. 2D) that power is applied to the coil of the circuit breaker to initiate the movement for the physical separation of the electrodes of the breaker as shown in FIG. 2E.
As seen in FIGS. 2F and 2D, the contacts separate at the conclusion of the period t mo , that is, at a period t arc before the next zero crossing.
When the electrodes of the breakers are physically separated, an arc is formed between the electrodes. The arc is extinguished when the current reaches the zero level, that is, at the conclusion of the period t arc .
To prevent restrikes inside the breaker after the current goes to zero, the duration of the arc, identified as t arc in FIG. 2D, should be greater than 3 milliseconds. If it is less than this, then the current will pass through zero and increase (in either a positive or negative direction) while the arc is still strong enough to restrike. Accordingly, t arc should be a minimum of 3 milliseconds.
In addition, to guard against the uncontrollable variation in the amount of time that it takes for the physical separation of the electrodes to occur (t mo ), which variation could be of the order of 2 milliseconds, it is preferable that the period t arc should be of the order of 5 milliseconds.
The actual magnitude t arc is entered into microprocessor 7 by keyboard 17. The period t mo is determined by a calibration procedure at a standard temperature, for example, 20° C.
It will then be observed that
t.sub.o =t.sub.y +t.sub.mo +t.sub.arc (1)
As t o is known (in the present example, t o =3 cycles. In the North American case, each cycle is equal to 16.6 msec so that t o =50 msec) and t arc is selected to be of the order of 5 milliseconds. The value of t mo is determined, at the standard temperature, by calibration, and the value of t y is calculated by the microprocessor 7.
In order to determine the values of the above periods at temperatures other than 20° C., the opening time t mo2 at temperature T 2 is calculated using the relationship
t.sub.mo2 =t.sub.mo1 -a.sub.o (T.sub.2 -T.sub.1) (2)
where
a o is a value which is indicative of the sensitivity of the breaker to temperature and is given by the breaker manufacturer
T 2 is equal to the temperature of interest
T 1 is equal to the standard temperature is equal to, in a particular embodiment, 20° C.
t mo1 is equal to the switch opening time at 20° C.
t mo2 is equal to the switch opening time at T 2 .
The value of t mo2 is calculated with equation (2), and the value of t y is calculated using the programmed value of t arc and the calculated value of t mo2 applied in equation (1) above.
With the above calculation, the parameters for opening the breaker are determined. The processor 7 sends out signals to the controller 13 which initiates appropriate action (e.g. applying an opening signal to the coil of the breaker) to affect the opening in accordance with the calculated timing.
As seen from FIG. 1, the zero crossing is determined only for phase A. However, as phases B and C have a known phase relationship to phase A (e.g. phase B is separated from phase A by angle P a and phase C is separated from phase B by angle P b ), timing for these phases is determined in a straightforward manner. Specifically, the zero crossing occurs at P a /360 (t cycle ) msec after the zero crossing for phase A. In a like manner, the zero crossing for phase C occurs at p b /360 (t cycle ) after the zero crossing for phase A.
In practice, temperature readings are taken at predetermined intervals and the value for t mo is calculated whenever a temperature reading is taken. When an actuating signal is received, the value of the last calculated t mo is used.
In addition, the t mo of phase A may not be identical with the t mo of phase B or of phase C. Accordingly, separate calculations have to be made at each temperature for the value t mo of each phase. Further, the value a o may also be different from each phase. The values for a o for each phase are stored in the processor 7 and are identified as such to perform appropriate calculations.
As is also well known, it is not possible to continuously convert the analog signal to a digital value. Instead, samples have to be taken. In accordance with a particular embodiment of the invention, 32 samples are taken during each cycle of the voltage/current.
The parameters for determining the closing times for the breakers are illustrated in FIG. 3. As seen in FIG. 3A, the total closing time t c is once again equal to an integral number of cycles. Once again, the number of cycles illustrated in FIG. 3 is 3.
The closing signal is, as seen in FIG. 3C, initiated at the beginning of the time period t cc . Once again, the computer monitors for the first zero crossing, illustrated in FIGS. 3B and 3D as appearing at the beginning of the time period t x . t x is a waiting period and a closing signal is applied to the coil of the breaker at the expiration of the period t x . As seen in FIGS. 3D and 3E, this occurs at the beginning of the period t mc . The period t mc , that is, the time that it takes the contacts to move from an open to a closed position, is once again a function of the particular breaker and is once again calibrated at a standard temperature, for example, 20° C. In order to determine the period t mc2 for a temperature T 2 , different from 20° C., use is made of the relationship
t.sub.mc2 =t.sub.mc1 -a.sub.c (T.sub.2 -T.sub.1) (3)
where
a c is once again given by the manufacture of the breakers.
It can also be seen from FIG. 3 that
t.sub.c =t.sub.x +t.sub.mc +8.33 msec-t.sub.del (4)
As t c and t mc are already known, and as t del is selected to enable the exact point of initiation (the onset of the period t mc ) to be fixed with exactness, the period t del is also known, and the period t x can be determined from equation (4).
By definition, t del is the time delay between the last zero crossing of the phase voltage before the mechanical closure of the circuit breaker contacts and the actual contact closure. When the circuit breaker is used with an inductance or with a transformer, t del should be set around 2 ms in order to avoid the high inrush currents which can cause high electrodynamic stresses on the windings. High inrush currents occur when the breaker contacts close near zero phase voltage i.e. when t del is close to zero. Conversely, when the circuit breaker is used with a capacitor bank, t del should be close to zero in order to prevent high inrush currents which would stress the capacitors and damage the contacts of the circuit breaker.
As seen in FIG. 3F, the contacts move from an open to a closed position upon termination of the period t mc . Once again, the timing of phases B and C are determined knowing the relationship between the signals on phases A, B and C. In addition, the value t mc2 must be separately calculated for each phase A, B or C taking into account the value of a c and of T 2 .
Although a particular embodiment has been described, this was for the purpose of illustrating, but not limiting, the invention. Various modifications, which will come readily to the mind of one skilled in the art, are within the scope of the invention as defined in the appended claims.
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The system for timing the opening and closing of a high power switching arrangement breaker used in an electrical transmission system measures the temperature of the breaker and the phase of the power signal being switched. A control circuit provides a control signal for opening and closing the breaker in response to an initiating signal, the control signal being timed as a function of the temperature and the phase angle to make sure that contact is either made or broken at an appropriate time to reduce arcing. By taking into consideration temperature and its effects on the response of the breaker, arcing is significantly reduced.
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BACKGROUND OF THE INVENTION
The field of the invention relates to a boat and more particularly concerns a boat with a hull including a pad bottom.
Observation and experience has shown that the traditional boats with pad bottom hulls are typically very light and travel at high speeds and many require a great deal of skill to pilot. These traditional pad bottom hulls are very inefficient when the boat is loaded for tournament fishing and a great amount of speed is lost.
An example of a prior pad is disclosed in U.S. Pat. No. 4,584,959. The pad is generally rectangular and it gradually changes in shape as shown in FIG. 13. The rectangular pad includes two horizontal strakes along its edges.
SUMMARY OF THE INVENTION
In the present invention the intent is to provide a pad surface having a flat wide portion for maximum boat lift and include in a pad profile hydrodynamic features to maximize the stability of the boat; to retain a soft ride of the boat; and to reduce the normal drag resulting from the prior boats having rectangular pad configurations.
In one feature of the preferred embodiment the pad surface has a width at the stern which is appropriate for the size and weight of the boat. The pad surface then transitions narrower as it progresses forward to meet the bow of the boat. This results in reduced drag and retains a soft ride for the boat.
In other features of the preferred embodiment additional surfaces are blended to both edges of the pad surface to form a pad. One other feature is a negative V surface which is blended to both edges of the pad surface adjacent the stern of the boat. These negative V surfaces form reverse wedge surfaces. Another feature is a positive deadrise surface which is blended to both edges of the pad surface forward of the reverse wedge surfaces and which extends towards the bow of the boat. The reverse wedge surfaces and the deadrise surfaces on both sides of the pad surface meet at an intersection between the negative surface of the reverse wedge surface and the positive surface of the deadrise surface. These reverse wedge surfaces and positive deadrise surfaces provide multiple benefits in the operation of the boat. First, this shaping of the outer edge of the pad improves the stability of the boat. This stability is believed to be improved by the forces created by the resultant direction of the water flow at the intersection of these surfaces since the two directions of water flow meet at this intersection. This water flow edge loading is believed to make the boat more stable; as if it had outriggers. Second, the intersection of the two directions of water flow is believed to result in the retention of more of the kinetic energy as the force of the water flow is no longer being lost in spray thrown out along the side of the boat.
In still another feature of the preferred embodiment the pad surface at the stern of the boat is altered relative to the boat bottom. The rear of the pad surface at the stern is tipped upwardly. By tipping the rear of the pad surface upward the boat increases its trim angle without requiring the propeller to generate lift. This particularly improves the hull efficiency and the runing attitude of the boat.
An alternative embodiment of a different boat which includes the features of the preferred embodiment is also disclosed.
All the pad features of the preferred and alternative embodiment maximize the flow of water past the boat in a rearward direction while retaining the ability of the boat to encounter changing wave patterns without a pounding of the boat.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a boat.
FIG. 2 is a top plan view of the boat of FIG. 1.
FIG. 3 is a bottom plan view of the hull for the boat of FIG. 1.
FIG. 4 is a partial broken away view of a portion of the hull of the boat shown in FIG. 1 particularly showing the bottom pad.
FIG. 5 is an end elevation view showing the transom of the boat of FIG. 1.
FIG. 6a through 6g are a series of partial profiles along the boat of FIG. 1 particularly showing a portion of the hull and the bottom pad.
FIG. 7 is a side elevation view of an alternate embodiment of a boat.
FIG. 8 is a top plan view of the boat of FIG. 7.
FIG. 9 is a bottom plan view of the hull for the boat of FIG. 7.
FIG. 10 is a partial broken away view of a portion of the hull of the boat shown in FIG. 7 particularly showing the bottom pad.
FIG. 11 is an end elevation view showing the transom of the boat of FIG. 7.
FIG. 12a through 12g are a series of partial profiles along the boat of FIG. 7 particularly showing a portion of the hull and the bottom pad.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A planing boat 10 is shown in FIGS. 1 through 4. The boat 10 includes an outboard motor 12 and a drivers console 14. The boat has a bow 16, a stern 18, a port side 20, a starboard side 22 and a top deck 24. The boat 10 which is preferably formed of reinforced fiberglass includes a planing hull 26 having a bottom planing surface and transom 30. An well or notch 32 is formed at the transom 30 to mount the outboard motor 12. The bottom planing surface includes a bottom pad planing surface or pad 34
The pad 34 is the primary feature of the preferred embodiment. The pad 34 is generally centered on the boat center line 36 at the lower portion of the bottom planing surface 28. The pad 34 is best shown in FIGS. 3, 4 and 5. Referring to FIG. 3, the pad 34 is symmetrical to the bottom planing surface 28 and contains a first pad surface 38, a second pad surface 40 and a third pad surface 42.
The pad 34 extends from the transom 30 towards the bow 16 as shown in FIGS. 3 and 4. The pad 34 at the stern 18 is selected to have a width proportional for the size and weight of the boat. For a Procraft Model SP 180 manufactured by Brunswick Marine the pad width 44a of the first pad surface 38 of the pad 34 at the stern 18 is about 9 inches. The pad surface 38 is transitioned to narrow as it traverses towards the bow 16.
The shape of the pad 34 at the stern is best shown in FIG. 6a. FIG. 6a is the pad profile at the beginning of the pad 34 at the stern 18 and FIG. 6g is the pad profile at about the end of the pad 34 in the direction of the bow 16. The width 44g of the first pad surface 38 of the pad profile in FIG. 6g is about 0 inches. In other words, the pad profile at FIG. 6g is at about the end of the first pad surface 38.
FIGS. 6b through 6f are intermediate pad profiles at 18 inch increments along the pad 34. The width 44b in FIG. 6b is about 71/4 inches. The width 44c in FIG. 6c is about 6 inches. The width 44d in FIG. 6d is about 43/8 inches. The width 44e in FIG. 6e is about 2 inches. The width 44f in FIG. 6f is about 3/8 inch.
Another feature of the preferred embodiment are reverse wedges 46a and 46b. The reverse wedges 46a and 46b are blended to the edges 48a and 48b of the first pad surface 38 of the pad 34 for a portion of the pad 34 between the profile at FIG. 6a and the profile at FIG. 6b. The reverse wedges 46a and 46b form the second pad surface 40. In FIG. 6a the reverse wedges 46a and 46b each have a width 50 of about 2 inches.
The pad 34 also includes deadrise surfaces 52a and 52b which are blended with the edges 48c and 48d of the first pad surface 38 of the pad 34 for a portion of the pad 34 between the profile shown in FIG. 6c and the profile shown in FIG. 6g and extending to the intersection of the two dead rise surfaces 52a and 52b at about a point 54 on the centerline 36. The deadrise surfaces 52a and 52b form the third pad surface 42.
The reverse wedge 46a blends and intersects at a line or plane 56a with the deadrise surface 52a. The reverse wedge 46b blends and intersects at a line or plane 56b with the deadrise surface 52b. These intersections 56a and 56b direct the flow of water past the hull 26 towards the stern 18 of the boat 10.
FIG. 6b shows a point 56 at the intersection 56a of the reverse wedge 46a and the deadrise surface 52a. FIG. 6b also shows a point 56 at the intersection 56b of the reverse wedge 46b and the deadrise surface 52a. FIG. 6c also shows a point 56 at the intersection 56a of the reverse wedge 46a and the deadrise surface 52a. FIG. 6c also shows a point 56 at the intersection 56b of the reverse wedge 46b and the deadrise surface 52a.
FIG. 6d through 6g no longer show the reverse wedges 46a and 46b since they have ended prior to these profiles. FIGS. 6d through 6g show a gradual change in the deadrise surfaces 52a and 52b as they transition towards the point 54 at the bow 16.
The total width 58a of the pad 34 at the profile of FIG. 6a is about 13 inches. The total width 58b of the pad 34 at the profile of FIG. 6b is about 123/4 inches. This includes a portion of about 11/2 in wide 60a for each of the deadrise surfaces 52a and 52b and a portion of about 11/4 inch wide 62a for each of the reverse wedges 46a and 46b.
The total width 58c of the pad 34 at the profile of FIG. 6c is about 121/2 inches. This includes a portion of about 21/2 in wide 60b for each of the deadrise surfaces 52a and 52b and a portion of about 3/4 inch wide 62b for each of the reverse wedges 46a and 46b.
The total width 58d of the pad 34 at the profile of FIG. 6d is about 123/8 inches. The total width 58e of the pad 34 at the profile of FIG. 6e is about 121/4 inches. The total width 58f of the pad 34 at the profile of FIG. 6f is about 121/8 inches. The total width 58g of the pad 34 at the profile of FIG. 6g is about 12 inches.
The entire pad 34 is stepped down or away from the remaining portion of the planing hull 26 with a step 64 of about 1 to 11/2 inches as shown in FIGS. 6a through 6g.
The acute angle 66a from the horizontal between the first planing surface 38 and each of the reverse wedges 46a and 46b in FIG. 6a is about minus 1 degree. This results in a trough or tunnel 68 of about 1/8 inch deep within the pad 34. The combination of the flat surface of the first planing surface 38b and the reverse or negative 1 degree surface of the reverse wedges 46a and 46b permits the boat 10 to carry the weight of additional people while at the same time reducing the friction of these surfaces as the weight of the boat is increased.
The acute angle 66b from the horizontal of each of the reverse wedges 46a and 46b in FIG. 6b is also about minus 1 degree and the acute angle 70b from the horizontal of each of the deadrise surfaces 52a and 52b is about 8 degrees. The acute angle 66c from the horizontal of each of the reverse wedges 46a and 46b in FIG. 6c is also about minus 1 degree and the acute angle 70c from the horizontal of each of the deadrise surfaces 52a and 52b is about 91/2 degree. The acute angle 70d from the horizontal of each of the deadrise surfaces 52a and 52b in FIG. 6d is about 10 degrees. The acute angle 70e from the horizontal of each of the deadrise surfaces 52a and 52b in FIG. 6e is about 15 degrees. The acute angle 70f from the horizontal of each of the deadrise surfaces 52b in FIG. 6f is about 22 degrees. The acute angle 70g from the horizontal of each of the deadrise surfaces 52a and 52b in FIG. 6g is about 28 degrees.
It can therefore be seen that the acute angle from the horizontal of the deadrise surfaces 52a and 52b increases from the stern 18 towards the bow 16. This increasing angle helps lower the drag of the boat 10 allowing faster planing of the boat 10.
An additional feature of the preferred embodiment is the altering of the pad 34 relative to the boat 10. The rear portion 72 of the pad 35 is tipped upward towards the stern 18 of the boat 10. By tipping the the rear of the pad 34 upward the boat 10 increases its trim angle without requiring the propeller to generate lift. The propeller trim angle can be adjusted to utilize the maximum thrust in moving the boat forward and to eliminate the loss of thrust from the propeller generating lift to the boat 10. The tipping line 74 through the pad 34 is identified in the Figures to be at plane 0--0. At the tipping line 74 the rear of the pad 34 for a distance 76 of about 42 inches is tipped upward at an angle 78 of about 3/4 degrees. The preferred tipping angle is in the range of 1/2 to 3 degrees for a length of about 36 inches to 60 inches depending on the weight and the length of the boat 10. The tipping of the rear portion 72 of the pad 34 improves the efficiency of the planing hull 26 and improves the running attitude of the boat 10.
An alternative embodiment of the invention is shown in FIGS. 7 through 12. The feature of the pad and the alternative features of the reverse wedges and the tipped rear portion of the pad are similar to that described for the preferred embodiment described above and shown for boat 10, but are modified for the alternative embodiment shown and described for boat 110.
In the alternative embodiment, a planing boat 110 is shown in FIGS. 7 through 10. The boat 110 includes an outboard motor 112 and a drivers console 114. The boat has a bow 115, a stern 118, a port side 120, a starboard side 122 and a top deck 124. The boat 110 which is preferably formed of reinforced fiberglass includes a planing hull 126 having a bottom planing surface and transom 130. An well or notch 132 is formed at the transom 130 to mount the outboard motor 112. The bottom planing surface includes a bottom pad planing surface or pad 134
The pad 134 is the primary feature of the alternative embodiment. The pad 134 is generally centered on the boat center line 136 at the lower portion of the bottom planing surface 128. The pad 134 is best shown in FIGS. 9, 10 and 11. Referring to FIG. 9, the pad 134 is a symmetrical to the bottom planing surface 128 and contains a first pad surface 138, a second pad surface 140 and a third pad surface 142.
The pad 134 extends from the transom 130 towards the bow 116 as shown in FIGS. 9 and 10. The pad 134 at the stern 118 is selected to have a width 144 proportional for the size and weight of the boat. For a Procraft Model PF 1700 manufactured by Brunswick Marine the pad width 144a of the pad 134 at the stern 118 is about 8 inches. The pad 34 is transitioned to narrow as it traverses towards the bow 116.
The shape of the pad 134 at the stern is best shown in FIG. 12a. FIG. 12a is the pad profile at the beginning of the pad 134 at the stern 118 and FIG. 12g is the pad profile at about the end of the pad 134 in the direction of the bow 116. The width 144g of the first pad surface 138 of the pad profile in FIG. 12g is about 1 inches. In other words, the pad profile at FIG. 12g is very close to the end of the first pad surface 138.
FIGS. 12b through 12f are intermediate pad profiles at 18 inch increments along the pad 134. The width 144b in FIG. 12b is about 6 inches. The width 144c in FIG. 12c is about 5 inches. The width 144d in FIG. 12d is about 4 inches. The width 144e in FIG. 12e is about 3 inches. The width in FIG. 12f is about 11/2 inches.
Another feature of the alternative embodiment are reverse wedges 146a and 146b. The reverse wedges 146a and 146b are blended with the edges 148a and 148b of the first pad surface 138 of the pad 134 for a portion of the pad 134 between the profile at FIG. 12a and the profile at FIG. 12e. The reverse wedges 146a and 146b form the second pad surface 140. In FIG. 12a the reverse wedges 146a and 146b each have a width 150 of about 21/2 inches.
The pad 134 also includes deadrise surfaces 152a and 152b which are blended with the edges 148c and 148d of the first pad surface 138 of the pad 134 for a portion of the pad 134 from the profile shown in FIG. 12a and extending to the intersection of the two deadrise surfaces 152a and 152b at about a point 154 on the centerline 136. The deadrise surfaces 152a and 152b form the third pad surface 142.
The reverse wedge 146a blends and intersects at a line or plane 156a with the deadrise surface 152a. The reverse wedge 146b blends and intersects at a line or plane 156b with the deadrise surface 152b. These intersections 156a and 156b direct the flow of water past the hull 156 towards the stern 118 of the boat 110.
FIGS. 12b through 12e show a point 156 at the intersection 156a of the reverse wedge 146a and the deadrise surface 152a. FIG. 12b through 12e also show a point 156 at the intersection 156b of the reverse wedge 146b and the deadrise surface 152a. FIG. 12f and 12g no longer show the reverse wedges 146a and 146b since they have ended prior to these profiles. FIGS. 12a through 12g show a gradual change in the deadrise surfaces 152a and 152b as they transition towards the point 154 at the bow 116.
The total width 158a of the pad 134 at the profile of FIG. 12a is about 13 inches. The total width 158b of the pad 134 at the profile of FIG. 12b is about 13 inches. This includes a portion of about 21/4 in wide 160a for each of the dead rise surfaces 152a and 152b and a portion of about 11/4 inch wide 162a for each of the reverse wedges 146a and 146b.
The total width 158c of the pad 134 at the profile of FIG. 12c is about 13 inches. This includes a portion of about 21/2 in wide 160b for each of the deadrise surfaces 152a and 152b and a portion of about 11/2 inch wide 162b for each of the reverse wedges 146a and 146b.
The total width 158d of the pad 134 at the profile of FIG. 12d is about 13 inches. This includes a portion of about 31/2 inches wide 160b for each of the deadrise surfaces 152a and 152b and a portion of about 1 inch wide for each of the reverse wedges 146a and 146b. The total width 158e of the pad 134 at the profile of FIG. 12e is about 13 inches. This includes a portion of about 4 inches wide 160b for each of the deadrise surfaces 152a and 152b and a portion 1 inch wide for each of the reverse wedges 146a and 146b. The total width 158f of the pad 134 at the profile of FIG. 12f is about 13 inches. The total width 158g of the pad 134 at the profile of FIG. 12g is about 13 inches.
The entire pad 134 is stepped down or away from the remaining portion of the planing hull 126 with a step 164 between about 0 and about 11/2 inches as shown in the profiles of FIGS. 12a through 12g.
The acute angle 166a from the horizontal between the first planing surface 138 and each of the reverse wedges 146a and 146b in FIG. 12a is about minus 1 degree. This results in a trough or tunnel 168 about 1/8 inch deep within the pad 134. The combination of the flat surface of the first planing surface 138b and the reverse or negative 1 degree surface of the reverse wedges 46a and 46b permits the boat 10 to carry the weight of additional people while at the same time reducing the fiction of these surfaces as the weight is increased.
The acute angle 166b from the horizontal of each of the reverse wedges 146a and 146b in FIG. 12b through FIG. 12e are also at about minus 1 degree. The acute angles 170b through 170g respectively from the horizontal of each of the deadrise surfaces 152a and 152b in FIG. 12b is about 8 degrees; in FIG. 12c is about 13 degrees; in FIG. 12d is about 14 degrees; in FIG. 12 is about 15 degrees; in FIG. 12f is about 20 degrees; and, in FIG. 12f is about 21 degrees.
It can therefore be seen that the acute angle from the horizontal of the deadrise surfaces 152a and 152b increases from the stern 118 towards the bow 116. This increasing angle helps lower the drag of the boat 110 allowing faster planing of the boat 110.
An additional feature of the preferred embodiment is the altering of the pad 134 relative to the boat 110. The rear portion 172 of the pad 135 is tipped upward towards the stern 118 of the boat 110. By tipping the the rear of the pad 134 upward the boat 110 increases its trim angle without requiring the propeller to generate lift. The propeller trim angle can be adjusted to utilize the maximum thrust in moving the boat forward and to eliminate the loss of thrust from the propeller generating lift to the boat 110. The tipping line 174 on the pad 134 is identified in the Figures to be at plane 0--0. At the tipping line 174 the rear of the pad 134 for a distance 176 of about 42 inches is tipped upward at an angle 178 of about 3/4 degrees. The preferred tipping angle is in the range of 1/2 to 3 degrees for a length of about 36 inches to 60 inches depending on the weight and the length of the boat 110. The tipping of the rear portion 172 of the pad 134 improves the efficiency of the planing hull 126 and improves the running attitude of the boat 110.
While embodiments and application of the invention or inventions have been shown and described, it would be apparent to those skilled in the art that modifications are possible without departing from the inventive concepts herein. Therefore, the invention is not to be restricted other than by the scope and equivalency of the following claims.
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A planing boat having a stern and a bow includes a hull having a generally flat central bottom surface forming a portion of a pad with the surface tapering from a specified width at the stern towards the bow. Reverse wedge surfaces blended with the central bottom surface at the stern and deadrise surfaces blended with the central bottom surface and intersecting with the reverse wedge surfaces continue forward towards the bow. The rear portion of the flat bottom surface is tipped upwardly towards the stern.
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CROSS-REFERENCE TO RELATED CASES
This application is a continuation-in-part application of application Ser. No. 210,264, filed Jun. 23, 1988, and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to livestock feeders and in particular to livestock feeders adapted to be used on the ground or mounted off the ground in stalls or on fences.
2. Related Art
Livestock feeders used on the ground are usually designed with a special shape, such as bucket-shaped, that are adapted to sit on the ground or to be mounted within old auto tires to keep the livestock, such as horses, from tipping over the feeder. Livestock feeders have also been rectangularly or square-shaped to sit directly on the ground and which provide inadequate drainage after a rain. Typically, known livestock feeders have smooth inside walls that slope outwardly enabling the livestock, and in particular horses, to rake the feed out with their nose. Such feeders are also susceptible to being overturned by the hooves of the livestock.
Stall type livestock feeders are adapted to be hung from brackets or otherwise suspended by hooks or snaps connecting through I-bolts or U-bolts in the feeding trough. Wire brackets or plastic rings are mounted around the top rim of the feeders to keep the livestock from scooping grain over the side of the feeder. However, such wire brackets or plastic rings are very dangerous as haltered livestock, and in particular horses, can become hung on the feeder by the halter snagging the brackets or plastic rings. Moreover, should the livestock succeed in getting a hoof over the rim of the bracket, injury may result to the hooves or legs when the animal attempts to extract itself from the feeder.
U.S. Pat. No. 439,298 (Hutter) discloses a manger A which can be mounted on two vertically spaced apart support plates D mounted in a corner between two walls B and C, the manger including a diagonal side 4 that extends between the two sides 2 and 3 and two vertically spaced apart fingers F which are attached to the diagonal side 4 and are respectively mountable on the support plates D.
U.S. Pat. No. 1,102,371 (Warren) discloses a rectangular feed box which is pivotally mounted within a supporting frame that can be mounted in a corner between two walls.
U.S. Pat. No. 1,259,790 (Shirley) discloses a generally rectangular feed manger which is pivotally mountable within a frame which can be attached to a wall.
U.S. Pat. No. 2,658,709 (Kendall) discloses a bowl-shaped animal feeder which uses tapered ribs 2 on its inner surfaces to prevent loss of feed due to "nosing" by the feeding animal.
U.S. Pat. No. 3,205,861 (Moore) discloses a feed tub 10 which can be mounted on two converging wood beams 18 and 19 by bolts 15, 16 and 17 which also retain a feed saver ring 30 in the tub.
U.S. Pat. No. 3,329,321 discloses a watering pail 10 which can be mounted in a corner between two walls by a bail 20 that is attached to both walls.
SUMMARY OF THE INVENTION
The ground and stall feeding stations of the present invention are preferably formed of high molecular weight polyethylene copolymer. The ground feeding station is designed with a flanged bottom to resist tilting, with the outer rim of the flange ridged to help maintain the bottom of the trough portion of the feeding station off the ground, thereby enabling water to drain from the trough after a rain. Raised deflectors extending from the inside walls of the feeding station prevent the livestock from raking grain out, as the nose of the livestock hits the raised deflectors and the feed grain falls back into the trough of the feeding station. The feeding station is formed without sharp corners or projections, thereby preventing injury to the livestock contacting the feeding station.
The stall type feeding station is designed to be mounted in a corner of the stall with either a single wall bracket and a spring-loaded snap tight lock in each diametrically opposed corner of the trough, or conventional U-bolts. The inside walls of the trough portion of the feeding station also include similar nose deflectors as in the ground type feeding station, thereby eliminating the need for the potentially dangerous rings and wire brackets. The top rim of the stall type feeding station may extend downwardly approximately 11/2 inches to strengthen and stabilize the trough in the corners, to eliminate any sharp edges and provide a bumper for the feeding station.
While the preferred method of construction of the feeding stations is to use a vacuum formation process using high molecular weight polyethylene copolymer, injection molding processes using other types of plastics could also be used.
The nose deflectors should preferably be rounded or V-shaped to provide strength and to prevent injury to the nose of the livestock.
The shape of the feeding station can be altered to accommodate mounting on a fence or the flat wall of a stall.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, features, objects and advantages of the invention are readily apparent from a consideration of the following description of the best mode of carrying out the invention when taken in conjunction with the figures, wherein:
FIG. 1 shows a perspective view of a ground type livestock feeding station in accordance with the invention;
FIG. 2 is a perspective view of a stall type livestock feeding station in accordance with the invention;
FIG. 3 is a top view of the ground type livestock feeding station;
FIG. 4 is a section of the ground type livestock feeding station taken along lines 4--4 of FIG. 3.
FIG. 5a shows the bracket mounted to a corner of a stall and the corner feed station in position to be mounted to the wall bracket;
FIG. 5b shows the corner feed station mounted to the wall of the stall;
FIG. 6 is a detail view of the spring-loaded snap locks used to retain the corner feeding station on the wall bracket; and
FIG. 7 shows a corner feed station with U-bolts mounted for attachment to the corner of a stall.
DETAILED DESCRIPTION
The perspective view of the ground type livestock feeding station shown in FIG. 1 shows the raised ridge portion 10 having an edge portion 12 for contact with the ground. The raised ridge 10 holds the bottom of the feeding station off the ground thereby enabling water to drain from the feeding station. Raised ridge portion is somewhat flexible to also assist in resisting tilting of the feeding station. The trough 14 is formed within a raised portion 16 and includes a plurality of nose deflectors 18 extending around the inner periphery of the trough. Top rim portion 20 is designed to prevent the livestock from gripping with their teeth. The side walls 22 forming trough portion 16 are sloped to resist tilting of the feeding station. The bottom portion 24 of trough portion 16 is rounded and somewhat flexible to absorb shocks to the feeding station when it is struck by the hooves of livestock and also to aid in resisting the tendency of the feeding station to tilt.
A hole 26 is drilled in the bottom 28 of trough 16 to enable drainage of water and moisture from the feeding station. Drainage of water may be aided by bottom 28 having a slight downward slope towards drainage hole 26.
FIG. 2 illustrates a perspective view of a preferred embodiment of a stall type livestock feeding station having the same general characteristics as the ground type livestock feeding station shown in FIG. 1. However, the trough portion is inverted and includes a top portion having a rounded front section 48 and sloping side sections 42 and 44 terminating in a truncated back section 46. Front portion 48 and side portions 42 and 44 have a flange extending approximately 11/2 inches downwardly as illustrated in FIG. 2 to aid in strengthening the feeding station and to provide a bumper for livestock butting up against the feeding station.
The trough portion extends downwardly from the top portion and includes a plurality of equally spaced deflector members extending substantially the entire depth of the trough portion. The truncated back section or portion can further include a projecting member extending outwardly for engagement with a mounting bracket and each respective front corner can include a mounting means.
The top view of the feeding station shown in FIG. 3 illustrates the general shape of the plurality of nose deflectors 18 that are equally spaced around the inner periphery of the trough portion of the feeding station. In a preferred embodiment of the ground type feeding station, the nose deflectors 18 are each approximately 11/4 inch wide and approximately 21/2 inches long and extend approximately from the top rim 20 to the bottom of the trough portion of the feeding station. In the embodiment shown in FIG. 3 there are thirteen nose deflectors 18 formed around the inner periphery of the trough portion.
Typical dimensions of a preferred embodiment of the ground type feeding station are a 29 inch diameter base, 7 inch deep trough 16, a 19 inch diameter at the top rim portion 20 and a 161/2 inch inner diameter of trough portion 16. The above dimensions provide approximately a four gallon capacity.
The cross-sectional view of the ground type feeding station shown in FIG. 4 serves to illustrate the general overall shape of the feeding station for both the ground and stall types. The wall thickness of the feeding station may vary from 1/8 inch to 1/4 inch with the former dimension preferably occurring at and between ridge portions 10 and 24 and the latter dimension existing in the bottom 26 of the trough portion of the feeding station. Sides 22 are preferably sloped at approximately 10 degrees as shown in FIG. 4 with the inner wall sloped inwardly and the outer wall sloped outwardly. The inner wall 30 of the trough may also be sloped at approximately 10 degrees, or as illustrated in the right side of FIG. 4, such inner wall may also be essentially vertical as shown at 30'.
Ridge 10 is preferably formed with a 1/8 inch radius; ridge 24 with a 1/2 inch radius and the inner rounded portion 32 of the trough with a 2 inch radius.
In addition to providing a virtually tip-resistant feeding station that is rugged and designed to provide injury-proof use for livestock, the feeding station of the present invention also helps prevent sand colic and saves feed by preventing deflection of feed from the feeding station by the specially designed nose deflectors.
FIG. 5a shows bracket 50 screwed or nailed in a corner formed by walls 49a and 49b. Bracket 50 also includes respective arms 51 and 52 with mounting hole 57 located in truncated portion 54 at the junction of the arms 51 and 52, and respective mounting holes 59 and 60 at each respective end of the feeding station 40. Mounting holes 59 and 60 are formed in each of inwardly directed projections 59' and 60' of the mounting bracket 50. Corner feed station 40 includes a projection 54 mounted in the approximate center of truncated back section 46 as well as a single snap type spring-loaded pin lock mounted respectively at positions 55 and 56 of feeding station 40.
FIG. 5b shows the corner feeding station of FIG. 5a mounted to wall bracket 50 by the insertion of projecting guide pin 54 in the hole 58 of bracket 50, and the respective projection of each of the snap locks positioned at locations 55, 56 within respective holes 59, 60 of the wall bracket. The corner feed station can be removed from wall bracket 50 simply by withdrawing the projections of each of snap locks 55 and 56 against their spring bias from the respective hole 59 and 60 of the wall bracket and also withdrawing pin 54 from hole 57 of the wall bracket.
The above mounting of the feeding station is very simple, leaving no outwardly extending projections that might cause injury to the livestock as the locking members at each corner of the feeding station are not exposed and projection 54 at the back extends toward the corner between walls 51 and 52.
FIG. 6 illustrates the construction of a snap lock 70 including projection 72 ring handle 74 and spring 75 between legs 76 and 78. Projection 72 is normally biased by spring 75 as shown in FIG. 6. projection 72 can be withdrawn by pulling on ring handle 74, thereby disengaging projection 72 of the spring lock from a mounting hole in the bracket as described above.
FIG. 7 shows a corner type feeding station 40 including U-bolts 54', 55' and 56" for attachment to the wall of a stall in a conventional manner.
The above description of preferred embodiments of a feeding station is not to be taken as limiting the scope of the invention, as those skilled in the livestock feeding station art will readily perceive various modifications of the feeding station. The scope of the invention is intended to be limited only by the accompanying claims and the equivalents of the various components recited therein.
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A livestock feeding station has a feeding trough with a series of spaced deflector members extending substantially the entire depth of the trough. The upper edge of the trough has a rounded section to prevent livestock from gripping with their teeth. The station can be ground mounted or removably attached to a stall with attachments.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S. Provisional Application Ser. No. 60/160,506 filed on Oct. 20, 1999, and entitled “Impacted Orthopedic Bone Implant,” which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention concerns a device for implantation into bone tissues, a method of manufacturing such a device, and a method of orthopedic treatment. More specifically, this invention is directed to an orthopedic mesh implant for implantation into bone cavities to support bone tissue adjacent to the cavity. The invention is also specifically directed to methods of manufacturing a mesh implant and to methods for treating patients using the mesh implant.
[0003] The repair and reconstruction of bone structures having a defect, such as a cavity, crack or chip, can be accomplished by directly fixing bone structures adjacent a defect to each other, such as by plate(s) and screw(s). In other instances an osteogenic material, i.e. a bone growth inducing material, can be introduced into the bone defect to promote bone growth to fuse the bone structures together. Implantation of bone growth material can be particularly advantageous where the bone includes a cavity because a portion of the bone structure or adjoining structure is missing. Cavities can be formed naturally, by trauma, or because of intentional harvesting of bone grafts for implantation into other bone structures.
[0004] While implants are known that may provide stability between adjacent bony structures, the effectiveness, as well as the cost of manufacture and availability of such implants, limits the advantages that may be realized.
[0005] In light of the above-described problems, there is a continuing need for advancements in devices and methods relating to orthopedic treatment of bone defects and diseases to reduce the treatment risks and enhance the patency bone fusion devices.
[0006] The present invention is such an advancement and provides a wide variety of benefits and advantages.
SUMMARY OF THE INVENTION
[0007] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated herein and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described processes, systems or devices, and any further applications of the principles of the invention as described herein, are contemplated as would normally occur to one skilled in the art to which the invention relates.
[0008] According to one form of the invention, there is provided an implant for insertion into bone structures. The implant comprises a hollow body having an interior chamber, a first and second end for bearing against bone tissue and each end having an opening providing communication with the interior chamber. The hollow body is formed to include one or more mesh sides having a grid work of openings into the interior chamber. Thus, the invention provides a device that is implantable into bone structures and provides a depot for deposition of bone growth inducing material to promote bone growth and to provide support for weak bone structures.
[0009] In another form, the invention provides an implant for supporting weak bone tissue. The implant comprises a mesh body having an interior chamber and a passageway therethrough and defining a longitudinal axis substantially parallel to the passageway; the body includes a first end and a second end, each end positioned substantially transverse to the longitudinal axis and each end having a supporting portion positioned about the perimeter of the respective ends. The mesh body also includes a central portion having a longitudinal wall extending from the first end to the second end and having formed therein a grid work of openings providing communication into the interior chamber. In preferred embodiments, the supporting portions include an uninterrupted support band positioned about the periphery of each of the first and second end. In other preferred embodiments, the implant includes at least one tool-engaging portion provided in the longitudinal wall. In still other preferred embodiments, the implant is formed as a one-piece unitary body.
[0010] It is one object of the present invention to provide an orthopedic bone support implant to facilitate reconstruction and/or repair of bone structures.
[0011] Further objects, features, aspects, forms, advantages and benefits shall become apparent from the description and drawings contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of one embodiment of an implant according to the present invention.
[0013] FIG. 2 is a top plan view in partial section of the implant depicted in FIG. 1 .
[0014] FIG. 3 is an end elevation view in partial section of the implant depicted in FIG. 1 .
[0015] FIG. 4A is a side elevation view in partial section of the implant depicted in FIG. 1 .
[0016] FIG. 4B is a side elevation view in partial section of an implant similar in configuration to the implant depicted in FIG. 1 , but having a shorter length.
[0017] FIG. 5 is a perspective view of one embodiment of a cylindrical implant according to the present invention.
[0018] FIG. 6 is an end elevation view in partial section of the implant depicted in FIG. 5 .
[0019] FIG. 7 is side elevation view in partial section of the implant depicted in FIG. 5 .
[0020] FIG. 8 is a side elevation view in partial section of an alternative embodiment of an implant according to the present invention.
[0021] FIG. 9 is a top elevation view in partial section of the implant depicted in FIG. 8 .
[0022] FIG. 10 is an end elevation view in partial section of the implant depicted in FIG. 8 .
[0023] FIG. 11 is an illustration of cutting a bone graft from the iliac crest.
[0024] FIG. 12 is an illustration of harvesting the cut bone graft from the iliac crest.
[0025] FIG. 13 is a side elevation view of an implant holder and an implant according to the present invention.
[0026] FIG. 14 is an illustration of impacting an implant of the present invention into bone tissue.
DETAILED DESCRIPTION OF THE INVENTION
[0027] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated herein and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described processes, systems or devices, and any further applications of the principles of the invention as described herein, are contemplated as would normally occur to one skilled in the art to which the invention relates.
[0028] The present invention contemplates an implant for insertion into bone structures. In one aspect of the invention, the implant provides a device for supporting weak bone structures. In other aspects, the implant provides a receptacle for deposition of bone growth material. In still other aspects the implant of this invention is intended to replace current mesh or cage-type devices for engagement with bone structures. The implant of this invention is provided to be implanted into bone structures. The phrase “implanted into bone structures” is not intended to limit this invention to implantation into a single bone structure. Therefore, it is also within the scope of this invention to provide implants that can be implanted between adjacent bone structures, for example, in an intervertebral space between adjacent vertebrae.
[0029] FIGS. 1-4A and 4 B illustrate one embodiment of a mesh bone implant 10 according to the present invention. Bone implant 10 includes a body 12 having an interior chamber 11 . Implant 10 also includes a first end 18 and opposite second end 20 and a central portion 22 extending from first end 18 to second end 20 . Central portion 22 includes a first longitudinal wall 13 having a first longitudinal wall portion 30 and a second longitudinal wall portion 32 and passageway 14 therethrough defining a longitudinal axis 16 .
[0030] First end 18 includes a support portion 24 positioned about its perimeter. In one form, support portion 24 includes an integrally formed support band 26 positioned circumferentially about longitudinal axis 16 . Band 26 is adapted to withstand impaction forces to seat impact implant 10 into a defect or a prepared cavity in the bone structure. In one form, band 26 is an uninterrupted band and can be provided as an integrally formed band having a cross section thicker than the cross section of other wall portions, i.e. walls 30 and 32 , of body 10 . Preferably, band 26 does not extend beyond either wall 30 or wall 32 in a direction orthogonal to and away from longitudinal axis 16 . In this form, wall portions 30 and 32 define a substantially planar surface extending from first end 18 to second end 20 . Band 26 can taper uniformly in a direction towards interior chamber 11 ; gradually increasing in width to a maximum width proximate to first end 18 . Extension of band 26 internally serves to provide a thickened portion to enhance the load-bearing capabilities of implant 10 . Further, internal projections of band 26 also provide a retaining ring about the perimeter of first end 18 . Ring 27 provides containment of osteogenic material deposited in internal chamber 11 and facilitates greater packing density of the osteogenic material by inhibiting the escape of the packed osteogenic material from the implant. In other forms, band 26 can be provided as a lip or abutment extending from the perimeter of first end 18 toward the interior chamber 11 proximate to first end 18 .
[0031] Band 26 includes an exterior bearing surface 42 . Preferably, first surface 42 defines a substantially planar surface positioned substantially to lie in a plane generally perpendicular to longitudinal axis 16 . Further, first surface 42 is adapted to engage an adjacent facing surface of a bone defect or bone cavity. In one form, the first surface is a roughened or knurled surface to secure implant 10 to the adjacent bone surfaces. First end 18 also includes an opening 21 into interior chamber 11 . In the preferred form of the illustrated embodiment in FIGS. 1-4 , interior perimeter of band 26 defines opening 21 .
[0032] Second end 20 is opposite central portion 22 from first end 18 . Second end 20 includes a second support portion 25 . Second support portion 25 can be provided as is substantially described for first support portion 24 and can include a second support band 27 . Further, second end 20 also includes an opening into interior cavity 11 as described for first end 18 .
[0033] In one embodiment, first end 18 and second end 20 are separated by a distance, d 1 . Distance d 1 is selected so that implant 10 is matingly received within a cavity or other defect in a bone structure. When d1 is properly selected, first end 18 and second end 20 each can bear against respective facing bone tissue of a cavity or other defect and provide support and strength to the bone structure. As an example of implants having varying d1 distances, an implant similar in configuration to implant 10 is illustrated in FIG. 4B . Implant 10 ′ is selected to have a shorter longitudinal length, d 1 , implant 10 .
[0034] It is also intended to include within the scope of this invention a series of implants, each having a configuration as described for implant 10 , but differing in length d 1 .
[0035] Central portion 22 extends from first end 18 to second end 20 and includes a longitudinal wall 13 . Longitudinal wall 13 includes a plurality of openings 31 providing communication with the interior chamber 11 . In one form, the plurality of openings 31 define a grid pattern or grid work on first wall 30 . Each of the plurality of openings 31 can be formed in a variety of configurations, including triangular, square, rectangular, and polyhedron. In a preferred form, the intersecting bars define a pattern of equilateral triangles or isosceles triangles. In another form, the gridwork or grid pattern is formed by a plurality of intersecting elongate bars. In a preferred form, the plurality of intersecting elongate bars include a first group of elongate bars have a longitudinal bar axis arranged perpendicular to longitudinal axis 16 and a second group of elongate bars having a longitudinal bar axis arranged non-perpendicular relative to longitudinal axis 16 . A plurality of joints are formed by the intersections of the elongate bars, each joint defining a corner of an opening into interior chamber 11 .
[0036] The elongate bars can define a repeating pattern of triangles on wall sections 30 and 32 , preferably isosceles triangles; more preferably, equilateral triangles. When equilateral triangles are used, the wall portions can have a maximum amount of open areas, while still retaining the requisite strength to support adjacent bone structures. The trim open area is intended to mean the sum of the area of the plurality of open portions 31 in walls portions 30 and 32 , respectively.
[0037] Preferably, the ratio of open area to the total surface area defined by either wall portion 30 (or wall portions 32 ) is greater than about 1:2; more preferably greater than about 3:4. That is, at least 50% of the exterior surface area of either wall portion 30 or 32 is open area.
[0038] Longitudinal wall 13 can include a first wall section 30 and an opposing second wall section 32 . First wall 30 extends from first end 18 to second end 20 and defines a plane that is substantially parallel with longitudinal axis 16 . Second wall 32 , similar to first wall 30 , extends from first end 18 to second end 20 and defines a plane that is also substantially parallel with longitudinal axis 16 . Thus in one form, first wall portion 30 and second wall portion 32 are positioned to lie substantial parallel to each other.
[0039] Longitudinal wall 13 also includes a tool insertion end 28 . Tool insertion end 28 is positioned substantially orthogonal to first wall portion 30 and extends in a direction substantially parallel to longitudinal axis 16 . Tool insertion end 28 includes the tool-engaging portion 34 . Tool-engaging portion 34 can be provided in a variety of features adapted to engage an insertion tool for insertion of implant 10 into a prepared bone tissue. For example, tool-engaging portion 34 can include a variety of indents and openings, which may or may not be threaded, to engage corresponding configured features on an insertion manipulation accessory (not shown) to facilitate implantation of implant 10 into bone tissue. In a preferred embodiment of FIGS. 1-4 , tool-engaging portion 34 includes a longitudinally extending threaded bore 35 and a driving indent 36 .
[0040] Tool insertion end 28 defines an exterior surface 37 . In one form, surface 35 is curved in a direction transverse to longitudinal axis 16 from wall portion 30 to wall portion 32 . In another form, the exterior surface defines an arcuate surface in a direction along axis 16 and extending from the first end.
[0041] Referring now to FIG. 5-7 , there is depicted another embodiment of a mesh bone implant according to the present invention for supporting bone structures. In the preferred form of the illustrated embodiment, mesh implant 110 includes a cylindrical body 112 having a mesh wall 113 defining an interior chamber 111 therein. Body 112 includes a passageway 114 therethrough defining a longitudinal axis 116 . Preferably, cylindrical wall 113 extends circumferentially about longitudinal axis 116 . In the illustrated embodiment, cylindrical wall 113 is formed in the shape of a cylinder. However, it is understood that the mesh wall 113 can define a variety of shapes, including shapes having at least one flat surface.
[0042] Body 112 includes a first end 118 and an opposite second end 120 . First end 118 and second end 120 each include a support portion 124 and 125 , respectively. In one form, support portions 124 and 125 each include a support band, 126 and 127 respectively, positioned circumferentially about longitudinal axis 116 . Support bands 126 and 127 can be provided as an uninterrupted band about the perimeter of first end 118 and second end 120 , respectively. Support band 126 includes an exterior surface 142 that is provided as a substantially smooth surface and defining a plane generally transverse to longitudinal axis 116 . Similarly, support band 127 includes an exterior surface 144 that is provided as a substantially smooth surface and defining a plane generally transverse to longitudinal axis 116 . The substantially smooth planar surfaces 142 and 144 of support band 126 and 127 , respectively, facilitate implantation of implant 110 into bone structures. These surfaces provide particular advantages when implant 110 is inserted into a prepared cavity in a bone structure and engage the walls of the cavity to provide additional support to the bone structure.
[0043] Support portions 124 and 125 are provided to withstand the requisite impulsion force to seat implant 110 into a bone defect or a prepared cavity. The support portions 124 , 125 can be formed from wall section having a thicker cross section then other wall sections of body 112 . Thus, the support bands 124 and 125 can be provided in a form as described above for support portions 24 and 25 .
[0044] First end 118 and second end 120 are separated by a distance, d 2 . Distance d 2 is selected so that implant 110 is matingly received within a prepared cavity or other defect in a bone structure. When d2 is properly selected, first end 118 and second end 120 each can bear against respective facing bone tissue of a cavity, bone defect or opposing faces of adjacent bone structures and provide additional strength to the bone structure(s).
[0045] First end 118 and second end 120 each include an opening, 121 into the interior chamber 111 . Opening 121 provides communication with passageway 114 through body 112 . In the preferred form of the illustrated embodiment in FIGS. 5-7 , the interior perimeter of bands 126 and 127 each define an opening 121 .
[0046] Mesh implant 110 , similar to mesh implant 10 , includes a central portion 122 extending from first end 118 to second end 120 . In one aspect, cylindrical mesh wall 113 defines central portion 122 . Cylindrical mesh wall 113 also includes a plurality of openings 131 . Openings 131 can be provided in a variety of patterns, including triangular (equilateral or isosceles), square, rectangular, and polyhedron, thereby forming a mesh wall. Preferably, outer peripheral wall 130 includes a uniform grid of a plurality of openings 131 . In another form, cylindrical mesh wall 113 can be formed by a plurality of intersecting elongate bars. The plurality of intersecting elongate bars include a first group of elongate bars have a longitudinal bar axis arranged perpendicular to longitudinal axis 116 and a second group of elongate bars having a longitudinal bar axis arranged non-perpendicular relative to longitudinal axis 116 . A plurality of joints are formed by the intersections of the elongate bars of the first and second groups, each joint forming an apex that defines a corner of one of the openings of the plurality of openings 131 into interior chamber 111 . In another form, cylindrical wall 113 is defined by a plurality of intersecting elongate bars including a first group of bars defining a plane perpendicular to longitudinal axis 116 . A second group of bars having an elongate axis arranged non-perpendicular to longitudinal axis 116 intersects the bars in the first group of bars. Again, a plurality of apexes are formed by the intersection of the first group of bars and the second group of bars. The apexes form one of the corners of the openings 131 in cylindrical wall 113 . Cylindrical wall 113 can be provided substantially as described for wall 13 .
[0047] Cylindrical wall 113 includes a tool engagement portion 134 . Tool engagement portion 134 can be provided as described for tool engagement portion 34 , and can include a threaded bore 135 and a driving indent 136 .
[0048] Another form of the invention is illustrated in FIGS. 8-10 . Mesh implant 210 is depicted generally as a rectangular prism body 212 having a central portion 222 and an interior chamber 211 formed therein. Body 212 includes a passageway 214 therethrough defining a longitudinal axis 216 . Body 212 includes a first transverse wall 240 , an opposite second transverse wall 246 , and a central portion 222 extending from first end 118 to second end 220 .
[0049] First end 218 includes an opening 221 extending into interior chamber 211 . Similarly, second end 220 includes a second opening extending into interior chamber 211 . First end 218 also includes a support portion 224 extending about the perimeter of first end 218 . Similarly, second end 220 includes support portion 225 extending about its perimeter. Support portions 224 and 225 each include a support band 226 and 227 , respectively, positioned generally circumferentially about longitudinal axis 216 . Bands 226 and 227 are adapted to withstand forces needed to impact implant 210 into a prepared cavity in a bone structure or between adjacent bone structures. In one form, bands 226 and 227 can be provided as integrally formed bands having a cross section thicker than the cross section of other wall portions, particularly mesh walls 230 and 232 , of body 210 . In other forms, band 226 (or 227 ) can be provided as an abutment or a lip extending from the perimeter of first end 218 (or second end 220 ) toward the interior chamber 211 substantially as has been described for bands 26 , 27 , 126 and 127 .
[0050] In a preferred form of the illustrated embodiment of implant 210 , first end 218 and second end 220 are provided as arcuate surfaces 252 and 254 , respectively, along a transverse axis 256 positioned to be substantially orthogonal to longitudinal axis 216 . Arcuate surfaces 252 and 254 each have a maximum height positioned between first transverse wall 240 and second transverse wall 246 . In use, at least a portion of arcuate surfaces 252 and 254 can extend into bone tissue, such as cancellous tissue underlying the endplates of vertebral bodies. Arcuate surfaces 252 and 254 inhibit expulsion of the implant from the bone cavity by providing an implant that has a maximum height that is greater than height of a surgically prepared bone cavity, for example, in an intervertebral space between adjacent vertebrae.
[0051] Central portion 222 also includes first longitudinal wall 230 and second longitudinal wall 232 . At least one, and preferably both, of longitudinal mesh walls 230 and 233 are positioned to define a plane that is generally parallel to longitudinal axis 216 . Further, first wall 230 and second wall 232 are provided with a plurality of openings 231 into interior chamber 211 . Preferably, first wall 230 and second wall 232 are provided with a pattern of substantially uniform apertures forming a mesh. The apertures can be provided in a variety of configurations, including circular, square, rectangular, polyhedron, and the like. A plurality of openings 231 , similar to the openings 11 described for implant 10 , can be formed into walls 230 and 232 . In a preferred form, the apertures are provided in a form of an equilateral or isosceles triangle. Further, first wall 230 and second wall 232 can be defined by a plurality of intersecting elongate bars as described for cylindrical wall 113 for implant 110 and wall 13 of implant 10 .
[0052] In one form, implant 210 can be inserted in a defect or a prepared cavity between two bone structures to provide support and strengthen the adjacent bone structures. Therefore, body 212 can include a first transverse wall 240 extending between first end 218 and second end 220 and positioned generally orthogonal to longitudinal wall 230 , and an opposing transverse wall 246 also extending between first end 218 and second end 220 and positioned generally orthogonal to longitudinal wall 230 .
[0053] Transverse wall 240 can include a first bearing surface 242 , an opposite second bearing surface 244 , and a transverse face 247 therebetween. Preferably, first bearing surface 242 and second bearing surface 244 include substantially planar surfaces 243 and 245 , respectively, adapted to engage adjacent surfaces of the prepared bone cavity or bone defect. When inserted into the prepared cavity or bone defect, at least one of first bearing surface 242 or second bearing surface 244 bear against the adjacent bone tissue.
[0054] In one embodiment, first bearing surface 242 and second bearing surface 244 are separated by a distance d 3 selected to engage first bearing surface 242 and second bearing surface 244 with corresponding opposing adjacent bone structures in the prepared cavity or bone defect. Further, in a preferred aspect, first bearing surface 242 and second bearing surface 244 are substantially planar surfaces extending generally parallel to transverse axis 256 .
[0055] First transverse wall 240 includes a tool-engaging portion 234 . Tool-engaging portion 234 can be configured as described for tool-engaging portion 34 of implant 10 , including a threaded bore 235 and driving indent 236 .
[0056] In the preferred embodiments, first and/or second bearing surfaces 242 and 244 include anti-expulsion features 249 , for example, ridges, teeth, and other projections, adapted to inhibit the expulsion of implant 210 from the prepared cavity or bone defect. In the preferred form, the anti-expulsion features are adapted to minimize the force needed to insert implant 210 into the prepared space or bone defect, yet inhibit expulsion of implant 210 . Examples of such preferred forms include: at least one ridge transverse to longitudinal axis 216 , a plurality of ridges, teeth, or spikes. In a preferred form, the anti-expulsion features are adapted to minimize the force needed to insert implant 210 into prepared intervertebral space, yet inhibit expulsion of implant 210 . Examples of such preferred forms include ratchet-shaped ridges or teeth that have an apex pointing toward the first terminal end. When thus configured, the ratchet-shaped ridges or teeth chisel deeper into the cortical bone tissue in response to an expulsive force.
[0057] Body 212 also includes a second transverse wall 246 opposite the first bearing wall 240 . Second transverse wall 246 can include a third bearing surface 248 , an opposing fourth bearing surface 250 , and a face extending therebetween. Third and fourth bearing surfaces 248 and 250 , respectively, are separated by distance d 4 . In one preferred embodiment, distance d 4 is selectively greater than distance d 3 to conform to the desired prepared cavity in the bone structure, for example, in the intervertebral space between adjacent vertebrae. While third and fourth bearing surfaces 248 and 250 are shown as curved surfaces, it is understood that these bearing surfaces can be provided in a variety of shapes, including convex or ogival, in either the horizontal or vertical plane, or both, or substantially planar as depicted with the first and second bearing surfaces 242 and 244 , respectively. Further, third and fourth bearing surfaces 248 and 250 can include anti-expulsion features as described for the first and second bearing surfaces 242 and 246 .
[0058] Further, transverse wall 246 can include a tool-engaging portion as described for transverse wall 240 , including a threaded bore and a driving indent.
[0059] Reference will now be made to use of mesh implants 10 , 110 , and 210 to support adjacent weak bony structures. Typically, mesh implants 10 , 110 , and 210 can be inserted into a bone structure after preparation of a suitable bone cavity. For example, implants can be inserted into the cavity resulting from harvesting an autograft from the iliac crest. Often, harvesting autografts leads to significant post-operative pain and lengthy recovery time. Use of the implants disclosed in this invention facilitates reconstruction of the cavity and accommodates a quicker recovery time, often with less pain to the patient.
[0060] Referring now to FIGS. 11-14 , a selected portion of the iliac crest 260 is removed using a surgical cutting device, such as, for example, a chisel 262 , or a bone saw. After the selected region 264 of the iliac crest has been cut, the cut bone autograft 266 is removed from the residual bone structure 260 ′ of the patient as depicted in FIG. 12 . An implant as described in the present invention is selected for cavity 268 and to matingly engage in the adjacent bone structures 270 and 272 , respectively. The selected implant 274 is releasably attached to an implant holder 280 , preferably of a known variety. Preferably, implant holder 280 includes an implant insertion portion that is configured to matingly engage in tool-receiving portion 34 , 134 , and 234 of the selected implants. In preferred embodiments, the insertion portion includes a threaded shaft 284 to readily engage in a threaded bore in the implant. The implant insertion portion can also include a driving blade (not shown) to engage in a driving indent on the implant. In other embodiments, implant tool 280 can include a handle 288 , which may or may not include an impaction tool, such as a slap hammer, to impact the implant into the prepared bone cavity or bone defect.
[0061] Preferably, implants 10 , 110 , and 210 are made of a single, integral piece. The implants may be prepared from physiologically acceptable material having a requisite strength to withstand the compressive force exerted on the spinal column during normal activity. Examples of such acceptable material include: titanium, composites (carbon fiber or glass fiber composites), ceramics, bone, stainless steel, and surgical steel. Preferably, implants 10 , 110 , and 210 are prepared of metal such as titanium or surgical steel.
[0062] In the preferred manufacturing procedure, implants according to the present invention are made by an extrusion of a tube or hollow construct. The tube or hollow construct may or may not be substantially cylindrical. Preferably, the extruded tube may include end walls with increased thickness compared to sidewalls. After extrusion of the tube, the desired surface features, such as the support bands, anti-expulsion portions, tool-engaging portions, and the mesh configuration, may be defined or cut into the implant using a laser techniques well known in the art or any other suitable method. It will be understood that mesh implants created from extruded tube may be formed faster and with less waste than conventional milling of implants from solid blocks. The extruded implant preferably has already formed therein the cavity for receipt of the bone growth material or osteogenic material. After extrusion and laser cutting of the desired surface features, the implant can be machined to prepare implants having the desired size for uses in a variety of ages of patients and bone structures.
[0063] The present invention contemplates modifications in the porous bone implant as would occur to those skilled in the art. It is also contemplated that processes embodied in the present invention can be altered, rearranged, substituted, deleted, duplicated, combined, or added to other processes as would occur to those skilled in the art without departing from the spirit of the present invention. In addition, the various stages, steps, procedures, techniques, phases, and operations within these processes may be altered, rearranged, substituted, deleted, duplicated, or combined as would occur to those skilled in the art. Further, any theory of operation, proof, or finding stated herein is meant to further enhance understanding of the present invention and is not intended to make the scope of the present invention dependent upon such theory, proof, or finding.
[0064] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is considered to be illustrative and not restrictive in character, it is understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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This invention relates to a porous bone implant ( 10, 110 , and 210 ), a method of manufacturing the implant and a method of orthopedic treatment. The mesh implant can be manufactured using extrusion techniques and a variety of cutting and machining processes to provide the implant with the desired structural features and in the required dimensions to be matingly received within the bone defect or cavity. The implant can be used to strengthen bone structures and support bone tissue adjacent to a defect of cavity. Thus, the implant can be used to provide improved treatment of patients having bone defects or diseases with decreased postoperative pain and a shorter recovery time.
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SUMMARY OF THE INVENTION
This invention relates generally to a magneto-optical recording system employing near-field optics and more particularly to a magneto-optical recording system which employs cross-tapered rectangular optical waveguides each terminating in a narrow tip to direct light waves to the narrow tip where evanescent optical fields are coupled to an associated magnetic film and for transmitting light from the film reflected into the narrow tip.
BACKGROUND OF THE INVENTION
In magneto-optic recording systems, digital information is stored in a thin magnetic storage medium by locally magnetized regions or domains. The regions are magnetized to represent either ones or zeros. The information is written into the magnetic storage medium by raising the temperature of localized small regions of the magnetic medium to the Curie point temperature of the medium at the localized regions. This lowers the coercivity to a point which enables orientation of the magnetic domain by an external magnetic field. The size of the regions or domains determine the density of the digital information. The size of the localized region is limited by diffraction and is marginally improved by use of shorter wavelengths of light and higher numerical aperture lens. Stored information is read by Kerr or Faraday rotation of a polarized light beam incident on the magnetic medium by the magnetic fields at the magnetized regions or domains. The shift in polarization is in the order of 1 degree. This shift is employed to detect ones and zeros. Systems for reading out these small rotational changes are well established in the optical storage industry. Optical recording and the design of conventional read/write heads is described in the book entitled "Optical Recording" authored by Alan B. Marchant, Addison-Wesley Publishing, 1990.
Betzig and others have overcome the diffraction limitation definition by employing near-field optics. They have demonstrated orders of twenty nm or better for the magnetized regions or domains. (E. Betzig, J. K. Trautman, R. Wolfe, P. L. Finn, M. H. Kryder and C. H. Chang, "Near-Field Magneto-Optics and Hi-Density Data Storage", Appl. Phys. Lett. 61, 142-144, (1992)). The basic idea of near-field optics is to pass an optical beam into a metal covered optical fiber which is tapered down to a small size with a pinhole at its end. If this pinhole is placed close to the object being illuminated or imaged, in this instance the magnetic media, the definition is controlled by the size of the pinhole, rather by diffraction limits.
The problem with the use of a tapered fiber is that it does not propagate waves in the region where the diameter of the fiber is less than approximately 0.3 wavelengths of the light. Propagation through wave guide in this region is cut off and the loss of energy is extremely high, of the order of 30 dBs. Thus the amount of light energy which is applied to the medium is limited and heating of the medium to the Curie temperature requires a finite time. This makes it impractical for use with high speed storage systems. For example, with light penetration into the magnetic media of about 15 nm and an illumination wavelength of 546 nm, using quartz with fiber reflective index of 1.5, the minimum effective size of the beam in the propagating region of the quartz fiber is 140 nm. If the fiber is tapered to a size much smaller than this amount, the attenuation in the cutoff region is very high. Because of this high attenuation, the technique is unsuitable for optical storage at high data rates.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a magneto-optic recording system having an improved optical head for providing high intensity evanescent optical fields to a magnetic recording media.
It is another object of the present invention to provide an optical head which employs crossed tapered rectangular optical waveguides for transmitting light to a recording medium and for receiving light reflected therefrom.
It is a further object of the present invention to provide a magneto-optic recording system which employs crossed tapered rectangular optical waveguides which provide high intensity evanescent fields which heat the magnetic material at the intersection of the waveguides.
The foregoing and other objects of the invention are achieved by a magneto-optic recording system employing near-field optics including a read/write head assembly, for reading or writing information on a magnetic recording medium which includes crossed tapered optical waveguides, each terminating in a slit to couple light waves between the waveguide and magnetic medium.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects of the invention will be more clearly understood from the following description when read in conjunction with the following drawings.
FIG. 1 is an perspective view of tapered rectangular optical waveguide.
FIG. 2 shows a tapered rectangular optical waveguide formed in a silicon wafer.
FIGS. 3A and 3B are sectional views take along line 3--3 of FIG. 2 showing the angles of inclination of the tapered waveguide and an impinging focused light beams having different convergence angles.
FIG. 4 shows a magneto-optic recording system employing tapered crossed waveguides in accordance with the present invention.
FIG. 5 is an enlarged view in more detail of the portion 5--5 of the recording system.
FIG. 6 shows the relative output of a rectangular waveguide as a function of the waveguide thickness and width.
FIG. 7 is a perspective view of the crossed tapered optical waveguides of FIGS. 4 and 5.
FIG. 8 is a bottom view of the crossed tapered optical waveguides of FIG. 7 illustrating the E-fields.
FIG. 9 shows the glass fiber thickness and an outside which is roughly circular but is tapered. The inner cross is shown as a dashed line.
FIG. 10 shows a magneto-optic recording system employing the crossed tapered waveguides of FIG. 9.
FIG. 11 shows a magneto-optic recording system employing crossed tapered waveguides with the light provided by a flexible optical fiber waveguide.
DESCRIPTION OF PREFERRED EMBODIMENT
In accordance with the present invention, a tapered rectangular or elliptical optical waveguide which terminates in a narrow slit is used instead of a tapered optical waveguide which terminates in a round aperture. Referring to FIG. 1, the rectangular waveguide 11 transmits the TE 10 mode with the E-fields 12 directed normal to the upper and lower metal surfaces 13 and 14. As is well known, the waveguide can be tapered to a narrow slit "b" without cutting off the E-fields 12 if the width of the guide, width "a", is greater than 1/2 the wavelength of the light waves in the material filling the guide (S. Ramo, J. R. Whinnery and T. VanDuzer, "Fields and Waves in Communication Electronics", 3rd edition, chapter 8, Wiley 1994). It will be apparent to one skilled in the art that the waveguide may be elliptical and have rounded ends as long as the width is greater than approximately 1/2 the wavelength of the light in the medium filling the guide. Thus, unlike the prior art near field probes described above, all light impinging in the waveguide propagates to the end of the probe and high illumination efficiency and strong evanescent fields in the region beyond where the guide ends are obtained.
Referring to FIG. 2, a tapered waveguide 16 is shown formed in a silicon wafer 17. The tapered opening is formed by conventional masking and etching techniques. The walls of the tapered slit or waveguide 16 are metalized to minimize optical losses. The silicon wafer is made thin to minimize losses in the waveguide. As will be described, the silicon substrate is made part of a flying head so that it floats on the rotating magnetic disk. The angle of the beam impinging in the slit is made approximately equal to the taper angle of the slit and the beam is made slightly smaller than the receiving end of the waveguide so that the beam does not impinge on the walls of the slit until the width decreases no further because of diffraction. Ideally, a large aperture lens is used so that the beam tapers down to a small size before hitting the edges of the waveguide or slit. With the use of silicon, it is convenient to etch with KOH, from the <100> surface, to form <111> planes, 18, at an angle of 36° to the vertical, shown in FIG. 3a. In this case, it is not desirable to make the convergence angle of the beam greater than 36° from the vertical, for there will then be shadowing of the beam by the silicon taper, as shown in FIG. 3b, as well as multiple reflections of the beam at the taper 18c. The minimum size of the beam without the taper present would then be λ/2n sin(36°), where n is the refractive index of the medium. However, with the taper present, the beam can be made much smaller, provided that the inside of the taper is coated with metal and the fields are polarized across the taper. As noted above, the slit must be at least a half wavelength long for the media field filling the slit. For 546 nm wavelength light and an air filled slit, the length of the slit would be about 273 nm. With a longer slit, several tracks could be detected. For instance, with a 820 nm long slit facing the disk, one can detect three tracks. On the other hand, the slit can be tapered down to a fraction of a wavelength in the track direction without suffering much loss. For example, the slit might be in the order of 50 nm wide. Ideally, the slit or waveguide would be filled with silicon nitride to decrease the effective wavelength by a factor of two. Alternatively, a plastic with a refractive index of 1.5 can be used. This would enable one to decrease all dimensions by a factor of 2 or 1.5 and thereby provide an even narrower slit.
This is merely one example of how the slit can be made. Another possibility is to fill the silicon tapered slit with silicon nitride and etch the silicon away leaving a silicon nitride probe which can be covered with metal except on its bottom surface.
A magneto-optic recording system employing an optical head in accordance with the present invention is schematically illustrated in FIGS. 4 and 5. Data is recorded on and read from a magneto-optical disk 21. The disk may for example, have a magneto-optic film deposited on its front surface with a silicon nitride layer typically of the order of 50 nm thick laid down on top of the magnetic layer for protection and for optimizing the field distribution. Typically, the magneto-optic film may have a silicon nitride backing on aluminum. As with more conventional systems, a good example of a suitable magneto-optic material would be TbFeCo.
The optical head includes a focusing lens 22 which focuses light 23 into crossed tapered optical slit or waveguide 17 of the type described with reference to FIGS. 2 and 3. As described above, the length of the slit is greater than 1/2 wavelength in the material filling the guide, however, the width can be much smaller. A crossed waveguide wafer 17 is shown in FIGS. 7 and 8. It should be realized that the slits and waveguides are magnified. The light source excites a TE 01 mode on the vertical slit 16b with its long axis in the track direction, the direction of the magnetic tracks, with the principle E-field in the cross track direction. As described above, the guide can be tapered down in the cross track direction without the mode being cut-off providing that its length in the track direction is greater than a half wavelength in the material filling the guide. The second waveguide with its long axis 16a in the cross track direction will support a TE 10 mode with the principal E-field in the track direction. When information is to be stored or written on the magneto-optic material, both slits are illuminated so that the near fields at the crossing of the waveguides is of sufficient intensity to raise the temperature of the magneto-optic material above the Curie temperature. This can be done either by rotating the polarizer 26 in front of the light source laser 27 or by inserting a half waveplate 28 with its principle axis at 45 degrees with respect to the input polarization of the laser so that the polarization is rotated 45 degrees and both slits are excited. If the laser is unpolarized, then removing the polarizer and quarter wavelength would do just as well. The input power from the laser must be carefully controlled so that the beam through one slit alone does not provide evanescent (near) fields having sufficient intensity to heat the magneto-optic material to its Curie point. However, the light at the crossover region (the spot) has double the intensity and raises the temperature above the Curie point. The applied magnetic field will then form a well defined magnetic domain. It is clear that the crossover area may be fractions of a wavelength in area. Data is recorded by modulating the laser as the disk rotates.
FIG. 5 is an enlarged view of the magneto-optical disk and the recording head assembly. The silicon member 17 is carried on a suspension 31 from a cantilevered head actuator (not shown). The focusing lens 22 is held by support 33 and positioned by an electromagnetic assembly 32 including permanent magnets 34 and coils 35 to maintain its focus in the waveguides. Operation of the focusing of the magnetic head and the positioning of the head are well known and will not be further described.
In order to read the recorded data stored as magnetic domains, the polarizer is rotated to provide polarized light which excites the cross track waveguide 16a to provide E-fields 36, FIG. 8, in the track direction. A magnetic domain on the magneto-optical disk rotates the plane of polarization of the reflected wave. The E-field 37 in the cross track direction is picked up by the vertical slit 16b. Furthermore, the tapered slit 16a in the cross track direction can detect the directly reflected light component for tracking and locating the recording head.
The definition of the system both for recording and reading is dictated by the area of the crossover of the two slits. Slit lengths should be kept as small as possible for the sensitivity depends on the ratio of this area to the area of one slit. That is, if "a", FIGS. 1 and 2 is the length of the slit and "b" is its width, its sensitivity is reduced by approximately b/a or more exactly by 0.5 b/a+sin(πb/a)/π! since the variation in the fields along the length of the slit is sinusoidal. This function is plotted in FIG. 6.
In the receiving mode, the receiving slit or waveguide is aligned to receive the rotated polarized light. The light travels back through the objective lens 22 and is deflected by the beam splitter 37. If the directly reflected signal is of amplitude A, and the rotated component of value B, by using a half wave phase plate 38 followed by a polarizing beam splitter 39, signals are provided to detectors 1 and 2. The values of the signals are (A+B) 2 and (A-B) 2 . The difference of these signals is proportional to 2AB and thus proportional to the amplitude of the rotated component. Since A 2 >>B 2 , the sum of the two signals would be essentially A 2 . One of the detectors can have two or more photo-transducers and can be used for tracking and focusing.
The crossed waveguides described above are formed in a semiconductor wafer by masking and etching the wafer. They need not necessarily be of the same length. For instance, in FIG. 7, the vertical guide 16b needs only to be a half wavelength long while the horizontal guide 16a may be longer for tracking purposes. These lengths may be controlled by suitable masking of the silicon before etching with an anisotropic KOH etch. It is apparent that the tapered waveguides would be formed by shaping an optical fiber. Referring to FIG. 9, a tapered shaped optical fiber 40 is shown with a shaped core 41. The optical fiber core 41 is shaped in the form of a cross to terminate in crossed narrow slits 42 and 43. Each of the slits is fed by a tapered waveguide 46 and 47 respectively. The width of the waveguide defined by the ribs is greater than 1/2 wavelength in the material filling the guide at the operating wavelength. The thickness can be fractions of a wavelength whereby the crossing area 51 can be very small.
The fiber optic waveguide can be used in place of the wafer 17. Its end is supported by a support 52 which forms a floating support. The lens 22 illuminates the large end of the fiber optic waveguide. Other than the above substitution, the magneto-optic recording system operates as described with reference to FIGS. 4 and 5 and like reference numerals have been applied.
The light can be applied to the crossed tapered waveguides by a fiber optic cable. Referring to FIG. 11, a fiber optic cable 53 receives light from focusing lens 54 and applies the transmitted light to the crossed tapered waveguides carried by floating head 56. The other optical components comprising the light source, beam splitters, polarizers, half wave plates, etc., are located remote from the floating head 56, represented by the box 57. The floating head can be very light presenting low inertia positioning by the actuator 58. The optical components and their operation is described above and is also well known. Alignment of the system is now easy, since standard fiber-optic components can be used to insert the light into the fiber, and the taper is used to make the beam as small as is required, with metal coating on the fiber. Note that just as with the silicon taper, the input beam may be circular, but smaller in diameter than the length of the input slot. Tapering of the slot length and width can then be used to shape the beam. The use of the flexible cable greatly simplifies the construction of the magneto-optic recording system.
Thus, there has been provided a high density magneto-optical recording system in which the size of the magnetic domains is not diffraction limited.
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A magneto-optic recording system employing near-field optics which includes a read/write head having a pair of crossed tapered optical waveguides closely adjacent to the recording medium to provide light coupling between the tapered ends of the waveguides and the recording medium. The length of the waveguides being greater than one-half the wavelength of the light transmitted by the waveguides to transmit all light entering the waveguide to the tapered end and the width being a fraction of a wavelength of the light.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention pertains generally to consumer transaction cards and, more particularly, to the construction of a unitary, self-contained consumer transaction card.
2. Discussion of the Background of the Invention
The use of consumer transaction cards has increased greatly in the past few years. Such transaction cards have been employed as credit cards, debit cards, access control cards to control security by limiting access to designated areas, identification cards, automatic teller machine cards for obtaining money from currency dispensing machines, and the like. An example of such a card is presented in "A Unitary, Self-Contained Card Verification and Validation System and Method", Ser. No. 671,748, filed Nov. 15, 1984 issued on Sept. 30, 1986, as U.S. Pat. No. 4,614,861 and commonly assigned with the present invention. A number of prior art patented approaches are set forth and discussed in that application.
A number of calculators have been recently constructed that are approximately the same size as a credit card, but of greater thickness than a credit card. The K-MART (Model KMC 3) and IMA calculators (Models LC-672 and LC-682) utilize a metal center support having a rectangular frame and internal partitions to support and shield the calculator electronics and a metallized (or metal) rear layer to provide electrostatic shielding. The metal and plastic supports are in addition to the printed circuit card holding the display and electronics. Likewise, the EPSON and Radio Shack (Casio SL-750) calculators have a plastic center support having a rectangular frame and internal partitions for supporting and shielding the electronics with a metallize layer for shielding. The IMA models further use a separate outer frame around the periphery of the calculator.
The present invention improves upon the above approaches and provides a card construction for unitary, self-contained transaction cards of the type disclosed in the above-identified application and may have application to other consumer transaction cards.
SUMMARY OF THE INVENTION
The problems encountered in designing consumer transaction cards are to provide sufficient rigidity to the card while at the same time providing a simplified construction that is enduring and does not pose an inconvenience to consumers. Additionally, the elimination of layers such as the metallized layer or the frames with internal supports would greatly reduce the cost of construction and of thickness to the card. Since the various layers of such a card may be glued or otherwise affixed together, it is desirable to provide a card construction that minimizes the movement of the adhesive to the edges of the card. Such movement of adhesive is an undesirable characteristic of the card since consumers do not like a sticky substance around the cards and, more particularly, since adhesive may pick up lint or other undesirable materials.
The present invention overcomes the problems associated with unitary, self-contained card constructions, such as represented by the prior art calculators, by providing an outer support frame which surrounds the various layers of the card, a centrally located printed circuit board carrying the display, the keypad, and the necessary electronics for operating the card, top and bottom label sheets having the edges heat sealed to the outer support frame, and adhesive sheets for affixing the top and bottom label sheets to the printed circuit board.
Current consumer transaction cards such as credit and debit cards provide embossed consumer information by impressing the entire thickness of the card with the consumer information. Since the entire card is impressed, the conventional embossed information is structurally strong enough to withstand use in the retailer imprint machines and devices without destruction of the information. Embossing the entire consumer transaction card containing electronics may damage the electronics and, therefore, a problem exists for providing structural strength to this embossed information. In order to provide enduring support to the embossed consumer information located on the bottom label sheet, the embossed areas are limited only to the bottom label sheet and are backfilled to provide structural strength to the embossed consumer information.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded perspective view illustrating the various layers of the unitary, self-contained consumer transaction card of the present invention;
FIG. 2 is a cutaway-cross sectional view of the assembled consumer transaction card of the present invention;
FIG. 3 is the top planar view of the top label sheet of the present invention;
FIG. 4 is the bottom planar view of the top label sheet of the present invention;
FIG. 5 is an enlarged detail of the individual conductive carbon pads and epoxy spacer dots of the present invention;
FIG. 6 is a side cross sectional view of an individual keypad area of FIG. 4;
FIG. 7 is the top planar view of the adhesive web sheet located between the top label sheet and the printed circuit board of the present invention;
FIG. 8 is the top planar view of the printed circuit board of the present invention;
FIG. 9 is a top planar view of the outer support frame of the present invention;
FIG. 10 is a bottom planar view of the bottom label sheet of the present invention; and
FIG. 11 is a cross sectional view of the bottom label sheet of FIG. 10 showing the backfill of the embossed consumer information.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the various layers of the unitary, self-contained card of the present invention to include a support frame 100, a printed circuit board 110, an adhesive web sheet 120, a top layer sheet 130, a bottom label sheet 140, and an adhesive sheet 150. Each of these sheets will be discussed in the ensuing paragraphs.
The sheets are assembled as shown in FIG. 2 into a self-contained, unitary, consumer transaction card 10. The outer frame 100 provides structural support to the card 10. The printed circuit board 110 press-fittingly engages an inner support lip 112 of the outer support frame 100. The top label sheet 130 is heat-sealed at area 200 to the upper surface of the support lip 112 so that the upper surface 132 of the top label sheet lies in substantially the same plane as the upper surface 114. The adhesive web 120 holds the upper support sheet 130 to the printed circuit card 110. Likewise, the lower label sheet 140 is heat-sealed to the support frame 100 in the area shown as 210 so that the outer surface 142 of the lower label sheet 140 lies in substantially the same plane as the lower surface 116 of the support frame 100. The embossed consumer information 220 is backfilled with a material 230 to provide structural support to the embossed information 220 when used by consumers to minimize breakdown of the embossed information. An adhesive sheet 150 firmly holds the bottom label 140 to the printed circuit board 110.
Structural strength to the card 10 is provided by the printed circuit board 110 in combination with the support frame 100. Structural strength is also provided to the raised embossed consumer information 200 by the backfill material 230. The movement of the adhesive contained on sheets 120 and 150 towards the edges of the card 10 is prevented by the support frame 100 and the heat-sealing of the top label sheet 130 and the bottom label sheet 140 in areas 200 and 210. Furthermore, enough tolerance is provided in area 200 between the dimensions of the uPper label 130 and the support frame 100 to provide venting to the keypad area, as will be explained more fully.
In FIGS. 3 through 6, the details of the top label sheet 130 are set forth. The top label sheet 130 is preferably made from a polyester material and is approximately 2"×3" in dimension being approximately 3 mils thick. A rectangular shaped clear window 300 is provided against a colored background 310. Formed on the colored background are a plurality of keypad designations 320.
The obverse side of the top label sheet 130 is shown in FIG. 4. On the backside of the top label sheet 130 are deposited a plurality of epoxy spacer dots 400 formed around the border of each keypad 320. Centrally disposed in the plurality of epoxy spacer dots 400 are conductive carbon ink elliptically shaped pads 410. The details of the spacer dots 400 and the conductive pads 410 are shown in FIGS. 5 and 6. Each spacer dot is approximately 0.03 inches in diameter and approximately 0.0016 inches high. The conductive pad is a 0.1875 inch by 60 degree ellipse being 0.0004 inches high. The graphics 310 are first printed on the rear side of the card 130 followed by the screening of the carbon ink pads 410 and the epoxy spacer dots 400.
In FIG. 7, the details of the adhesive web 120 are set forth. The adhesive web sheet 120 is mounted on a poly-paper liner 700 for protection. The liner 700 is removed and discarded when assembled. The clear acrylic adhesive 710 is located on one side of the liner 700. The adhesive area 710 has downwardly extending fingers 720 which are designed to adhere to the top label sheet 130 and the printed circuit board 110 between the rows of the keypads 320. The adhesive fingers 720 are opened at the end 730 to provide a vent path to atmosphere. A cut-out 740 is provided in the adhesive 700 to provide a see-through for the display. An open border 750 and 760 is provided around the window 740 and around the periphery of the top label and does not contain the adhesive material 710. The adhesive material 710 is designed not to come into contact with the carbon pad 410 or the spacer dots 400. Typically, the adhesive web sheet 120 is 0.0015 to 0.002 inches in thickness.
In FIG. 8 is set forth the details of the printed circuit board of the present invention which is preferably made from a fiber glass laminate number 14 core having an underwriters laboratories rating of FR-4. The thickness of this board is preferably 0.014 inches. In FIG. 8, a window 800 is provided for mounting the display circuitry, a window 810 is provided for mounting the battery assembly, and a window 820 is provided for mounting the microprocessor. The keypad traces 830 are indicated as well as windows for discrete surface mount devices 840. The actual construction of this card 110 will vary from electronic arrangement to electronic arrangement and the present invention is not to be limited to the structure shown in FIG. 8. Such a printed circuit board 110 may, for example, contain the display, the keypad, and the associated electronics as shown in FIG. 3 of the above-identified pending application.
In FIGS. 2 and 9, the details of the support frame 100 are set forth. Support frame 100 contains an inwardly directed support lip 112 centrally located on the inner surface 900 of the 05 support frame 100. The support frame 100 is preferably made from a polycarbonate material and is injection molded as one piece. Typically, the thickness of the outer edge 910 of the support frame 100 is 0.030 inches and the thickness of the inner edge 920 of the support lip 112 is approximately 0.02 inches.
In FIG. 10, the details of the thin bottom label sheet 140 are set forth to include the conventional magnetic stripe 1000, the conventional signature panel 1010, and the conventional embossed consumer information 1020. This embossed consumer information 1020 may include, for example, an OCR number 1020a, an expiration date 1020b, bank information 1020c, and the name of the consumer 1020d. The bottom label 140 is typically 0.005 inches thick, but with the embossed consumer information 1020 that portion of the card can be as much as 0.025 inches thick. The sheet 140 is preferably made from a polycarbonate, aluminum or polyester material. Because of the thinness of the rear or exterior label sheet 140, a backfill material is provided for structural support. For example, in FIG. 11, the rear label sheet 140 is shown with two embossments 1020a and 1020b having the backfill material 230 inserted into the cavities created by the embossments 1020a and 1020b and rising to approximately 0.020 inches above the surface of the sheet 140. The backfill material 230 is preferably an ultraviolet adhesive which is viscous enough to be rolled into the embossed cavities as shown in FIG. 11. When the adhesive 230 is cured in an ultraviolet oven or the like, it provides structural support and strength to the embossed areas 1020. This differs substantially from conventional practice where the embossed consumer information on debit and credit cards is impressed after the cards are constructed. Of necessity, under the teachings of the present invention, the embossing takes place as the cards are constructed.
The unitary, self-contained consumer transaction card of the present invention is assembled in the following fashion. The top label sheet 130 is printed with suitable graphics. The epoxy spacers 400 and the conductive carbon ink pads 410 are screened onto the rear side of the top label 130 then the adhesive web 120 is placed on next. The frame 100 is then mounted in a suitable jig and the printed circuit board 110 is press-fittingly inserted into the frame 110 to engage the inner surface 920 of the support lip 112. Adhesive web 120 on the rear of the top label 130 is then placed over the printed circuit board 110 so that the edges of sheet 130 are carried on support lip 112. The top label sheet 130 is then heat-sealed to the support frame 100 in area 200. The partially assembled consumer transaction card 10 is then turned over and the battery and the display is inserted into the printed circuit board 110. Any necessary programming to the associated electronics occurs at this stage. The rear adhesive sheet 150 is then applied over the printed circuit board 110. The embossed rear label which, as previously discussed, is backfilled with material 230, cured and then applied over the adhesive sheet 150 and the edges of the bottom label sheet 140 are heat-sealed to the frame 100.
It is to be expressly understood that the unitary, self-contained consumer transaction card of the present invention is constructed according to ANSI specifications which are detailed in:
ANSI×4.16--1983
ANSI×4.13--1983
ANSI×9.1--1984
ANSI--AMERICAN NATIONAL STANDARDS INSTITUTE, INC.
and according to ISO standards which are detailed in
ISO 3554--1976 E
ISO 4909--1978 E
ISO 2894--1980 E
ISO--INTERNATIONAL STANDARD ORGANIZATION
While the present invention has been disclosed in a preferred embodiment, it is to be expressly understood that changes and modifications may be made thereto as set forth in the following claims. Further, while the invention has been disclosed for a unitary, self-contained consumer transaction card, it is to be expressly understood that its teachings apply to other types of transaction cards.
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An improved unitary, self-contained consumer transaction card having an outer support frame, an internally positioned printed circuit board, and top and bottom label sheets. The outer support frame provides structural support to the card and minimizes the flow of adhesives located under the top and bottom sheets out from the card. Backfill material inserted on the underside of the bottom label sheet and into the embossed consumer information provides structural strength to the embossed consumer information to prevent damage when the card is used.
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RELATED APPLICATIONS
[0001] This application is related to each of the following applications: “Graphical Calculator User Interface for Function Drawing” (HP Docket No.: 200310007-1); “Function Drawing in Polar Plan Using a Calculator” (HP Docket No.: 200310008-1); “Previous Calculation Reuse in a Calculator” (HP Docket No.: 200310016-1); and “Graphical Calculator” (HP Docket No.: 200310014-1), each assigned to the present assignee, all of which are hereby incorporated by reference in their entirety, and all of which are being filed concurrently herewith.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of and apparatus for input and evaluation of fractions using a calculator.
BACKGROUND
[0003] A hand-held calculator is an important and useful device. Similar to a computer, the hand-held calculator has a processor, a memory, a display, and an input device; however, there are important distinguishing differences between the hand-held calculator and the computer.
[0004] The hand-held calculator is a specialized device and not a general purpose device, as is true of a computer. Because of this specialization, typically the hand-held calculator costs less, has a longer useful lifespan, and is more reliable and more portable than the computer.
[0005] Whereas a general purpose computer is capable of executing many different programs, a hand-held calculator typically executes a single program and less frequently supports execution of user-created programs. Normally, a hand-held calculator supports addition, subtraction, multiplication, and division of numbers, either integer-based or decimal-based, entered by a user and displays the results on a built-in display.
[0006] A graphical calculator is a further specialized version of a hand-held calculator having a display which is typically larger than a regular hand-held calculator display in order to enable graph output. In many instances, graphical calculator displays are liquid crystal displays for more accurate representation and enhanced readability of a graph output.
[0007] A graphical calculator is able to display a graph of a specific expression, e.g. a sine wave representing a sinusoidal function, entered by a user. Disadvantageously, graphical capabilities on hand-held calculators are only available as part of expensive and complex, “high end” scientific calculators. These graphical calculators are more expensive than other calculators, typically costing hundreds of dollars. These graphical calculators are more complicated to operate than other calculators because of the large amount of functionality incorporated therein.
[0008] The increased functionality has required a corresponding increase in the number of keys required for manipulating and using the calculator. For example, currently available graphical calculators have approximately fifty (50) keys including two (2) shift or modifier keys for a user to manipulate, e.g. a Texas Instruments (TI) 83 plus calculator has 51 keys and two (2) shift keys which can be used concurrently, enabling up to four functions to be assigned per the 51 remaining keys, and a Hewlett-Packard (HP) 48G+/GX calculator has 49 keys and three (3) shift keys, enabling up to six functions to be assigned per the remaining 49 keys.
[0009] Additionally, and in conjunction with the larger number of keys present, a user must contend with different modes of operation of the current graphical calculator. Different modes of operation, accessible via specific keys and/or key sequences, must be utilized in order to access specific calculator functionality, e.g. a graphical calculator may include a fraction mode, a decimal mode, a binary mode, a hexadecimal mode, a finance mode, a statistics mode, and a graph mode.
[0010] Further, expression input requires increasingly complicated key manipulations and combinations. For example, in order to graph an expression, there are typically three combinations to be entered: a mode specifying combination, an expression entry combination, and a completion combination. The mode specifying combination may include manipulation of a graph key to instruct the calculator to graph the following expression entry. The expression entry combination may include manipulation of multiple keys to input the expression to be graphed and the completion combination includes manipulation of a key, e.g. an enter key, to instruct the calculator to perform the preceding operations, i.e. graph the entered expression.
[0011] Requiring a user to manipulate multiple keys increases the need for learning, the possibility of error and may lead to frustration on the part of the user. Also, requiring additional key presses by a user requires more time and slows the entry and use of the calculator by the user. The addition of multiple modes, complicated expression input combinations, and ever-increasing numbers of keys results in a very complicated device.
[0012] As further evidence of increasing complexity, the user manual for a currently available hand-held graphical calculator has dramatically increased in size in order to fully explain the use of the calculator. For example, the above-cited TI-83 plus calculator manual includes 269 pages and the HP 48G+/GX calculator manual includes 506 pages. These are very long documents which are typically not read by users. Further, users are likely to be deterred from reading the manual because of the imposing size of the manual.
[0013] Graphical calculators are very popular and effective educational aides. School students using graphical calculators can easily visualize complex functions; however, the complexity and cost of currently available graphical calculators deters many students and schools from making a purchase. Purchasers are dissuaded by the size of the manual, multiple modes of operation, and the number of keys and key combinations required for inputting expressions.
[0014] Prior hand-held calculators of which the inventor is aware, enable a user to input fractions, i.e. fractional numbers or numbers having a fractional component such as ⅔ or 3⅔; however, the prior calculators rely on one of two approaches. Prior approaches for calculators receiving fraction input include a fraction mode and designation of a fraction key.
[0015] Using a fraction mode and designating a fraction key both require a user to manipulate a designated key on the calculator thereby providing input to the calculator indicating that the subsequently entered expression is to be evaluated as a fraction. Disadvantageously, the user is required to learn and memorize an additional calculator mode and corresponding activation key, and manipulate additional keys for expression entry. Problematically, the user is more likely to mis-key either the designated fraction mode key or the expression and, at a minimum, additional keystrokes are required to input the fraction. Additional keystrokes necessitates more complexity, more time for input, and increased chance of an input error and frustration for the user.
[0016] Further disadvantageously, the use of a designated fraction key is expensive in terms of cost and keyboard area for implementation. Additionally, the increased calculator complexity requires a corresponding increase in the size of the user manual needed to describe operation of the calculator to the user.
[0017] There is a need in the art for a method of and apparatus for input and evaluation of fractions using a hand-held calculator.
SUMMARY
[0018] It is therefore an object of the present invention to provide a method of and apparatus for input and evaluation of fractions using a hand-held calculator.
[0019] The present invention provides a method of and apparatus for input and evaluation of fractions using a hand-held calculator.
[0020] A method aspect of input and evaluation of fractions using a calculator includes receiving a user-entered expression including a fraction where the fraction is entered using a division key. The user-entered expression causes the calculator to evaluate the user-entered expression and display the evaluated user-entered expression.
[0021] An apparatus aspect includes a calculator enabling input and evaluation of fractions having means for receiving and displaying a user-entered expression including a fraction entered using a division key. The calculator further includes a processor for evaluating the user-entered expression. An attached calculator display displays the evaluated user-entered expression.
[0022] Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention.
DESCRIPTION OF THE DRAWINGS
[0023] The present invention is illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:
[0024] FIG. 1 is a front face view of a graphical calculator according to an embodiment of the present invention;
[0025] FIG. 2 is a high level block diagram of a graphical calculator according to an embodiment of the present invention;
[0026] FIGS. 3 a and 3 b are depictions of a calculator display during operation of a calculator according to an embodiment of the present invention;
[0027] FIGS. 4 a and 4 b are depictions of a calculator display during another operation of a calculator according to an embodiment of the present invention; and
[0028] FIGS. 5 a and 5 b are depictions of a calculator display during another operation of a calculator according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0029] FIG. 1 is a front face view of a graphical calculator 100 according to an embodiment of the present invention.
[0030] Calculator 100 includes a display 102 and a primarily key-based input area 104 set in a front face 106 . Although front face 106 is depicted as a rounded rectangle, it is to be understood that the front face may be manufactured to be any of a number of different shapes. Further, although a specific number, type and configuration of input mechanisms are described below, it is to be understood that variations in the number, type, and configuration of input mechanisms may be found in different embodiments of the present invention.
[0031] Display 102 is a rectangular liquid crystal display (LCD) which is 96 pixels wide and 64 pixels in height. As shown in FIG. 1 , display 102 displays a sine wave 102 A on a graph having an X axis 102 B and a Y axis 102 C. Input area 104 includes four keys and one directional input device 108 in a row 110 and 16 keys arranged in a four by four grid 112 . Although a four by four grid is depicted and described, it is to be understood that the input area keys may be arranged in different configurations.
[0032] Directional input device 108 is used to navigate menus and perform information input, recall, and editing. Directional input device 108 may be manipulated by the user to input at least four directions, i.e. up, down, left, and right to calculator 100 . Input of the left arrow of directional input device 108 inputs a move left command to processor 204 thereby moving the current cursor position on display 102 to the left one position. Input of the right arrow of directional input device 108 inputs a move right command to processor 204 thereby moving the current cursor position on display 102 to the right one position.
[0033] A secondary function of directional input device 108 , accessible via use of shift key 114 as described below, is editing an expression on display 102 . The input of shift key 114 in conjunction with or prior to left arrow of directional input device 108 inputs a backspace command to processor 204 thereby deleting the character to the left of the current cursor position on display 102 . The input of shift key 114 in conjunction with or prior to right arrow of directional input device 108 inputs a delete command to processor 204 thereby deleting the character to the right of the current cursor position on display 102 .
[0034] The four remaining keys in row 110 are shift key 114 , open parenthesis key 116 , close parenthesis key 118 , and power key 120 .
[0035] Shift key 114 is used to access a second set of functions, i.e. secondary functions, assigned to the remaining keys on calculator 100 . For example, user activating power key 120 turns on calculator 100 ; however, activation of power key 120 subsequent to activation of shift key 114 turns off the calculator. In a similar fashion, each of the remaining keys of calculator 100 has an assigned secondary function.
[0036] Open parenthesis key 116 inputs a beginning parenthesis in a user-entered expression. The secondary function of open parenthesis key 116 is to input a command causing calculator 100 to split a graphical output on display 102 such that one half of the display is a graph and the other half is numerical information related to the graph displayed.
[0037] Close parenthesis key 118 inputs an ending parenthesis in a user-entered expression. The secondary function of close parenthesis key 118 is to input a T variable in a user-entered expression.
[0038] Power key 120 turns on calculator 100 and, as described above, the secondary function of power key 120 is to turn off calculator 100 . Additionally, power key 120 operates as a clear key after calculator 100 is turned on, i.e. the power key may be used to clear the displayed expression on display 102 . Manipulation of shift key 114 followed by right arrow of directional input device 108 deletes input characters to the right of the current input position and manipulation of shift key 114 followed by left arrow of directional input device 108 deletes input characters to the left of the current input position.
[0039] Beginning in the upper left corner of four by four grid 112 , the description of the remaining keys is now provided in a row, column order.
[0040] Row 1, column 1 key 122 , i.e. the seven key, inputs a seven (7) value in a user-entered expression and has a secondary function of inputting a sin function in a user-entered expression. Row 1, column 2 key 124 , i.e. the eight key, inputs an eight (8) value in a user-entered expression and has a secondary function of inputting a cos function in a user-entered expression. Row 1, column 3 key 126 , i.e. the nine key, inputs a nine (9) value in a user-entered expression and has a secondary function of inputting a tan function in a user-entered expression. Row 1, column 4 key 128 , i.e. the division key, inputs a division (/) function in a user-entered expression and has a secondary function of inputting a theta (θ) variable in a user-entered expression. Further, as described in detail below, the division key 128 is used to input a fractional value to calculator 100 . Division key 128 is input between input of the digits of the numerator and denominator of a fraction.
[0041] Row 2, column 1 key 130 , i.e. the four key, inputs a four (4) value in a user-entered expression and has a secondary function of inputting a square root function in a user-entered expression. Row 2, column 2 key 132 , i.e. the five key, inputs a five-(5) value in a user entered expression and has a secondary function of inputting a squared function, i.e. raising a value to the second power, in a user-entered expression. Row 2, column 3 key 134 , i.e. the six key, inputs a six (6) value in a user-entered expression and has a secondary function of inputting a value raised to the power of a subsequently entered value function, i.e. X raised to the power of Y, in a user-entered expression. Row 2, column 4 key 136 , i.e. the multiplication key, inputs a multiplication (*) function in a user-entered expression and has a secondary function of inputting an X variable in a user-entered expression.
[0042] Row 3, column 1 key 138 , i.e. the one key, inputs a one (1) value in a user-entered expression and has a secondary function of inputting an absolute value function in a user-entered expression. Row 3, column 2 key 140 , i.e. the 2 key, inputs a two (2) value in a user-entered expression and has a secondary function of inputting a natural logarithm function in a user-entered expression. Row 3, column 3 key 142 , i.e. the three key, inputs a three (3) value in a user-entered expression and has a secondary function of in putting eight logarithm function in a user-entered expression. Row 3, column 4 key 144 , i.e. the minus key, inputs a subtraction (−) function in a user-entered expression and has a secondary function of inputting a NOT function in a user-entered expression.
[0043] Row 4, column 1 key 146 , i.e. the execute key, inputs an execute command to calculator 100 and has a secondary function of inputting a menu command to the calculator. Row 4, column 2 key 148 , i.e. the zero key, inputs a zero (0) value in a user-entered expression and has a secondary function of inputting an e value in a user-entered expression. Row 4, column 3 key 150 , i.e. the dot key, inputs a decimal point in a value entry and has a secondary function of in putting a pi constant value in a user-entered expression. Row 4, column 4 key 152 , of i.e. the plus key, inputs an addition (+) function in a user-entered expression and has a secondary function of in putting a times ten to the power of a subsequently entered value, i.e. “10{circumflex over ( )}Y”, in a user-entered expression.
[0044] FIG. 2 is a block diagram illustrating an exemplary calculator 100 upon which an embodiment of the invention may be implemented.
[0045] Calculator 100 includes a bus 202 or other communication mechanism for communicating information, and a processor 204 coupled with the bus 202 for processing information. In one particular embodiment, processor 204 is a 16 bit processor. Calculator 100 also includes a main memory 206 , such as a random access memory (RAM) or other dynamic storage device, coupled to the bus 202 for storing data and expressions according to an embodiment of the present invention and instructions to be executed by processor 204 . Main memory 206 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 204 . In one particular embodiment, main memory 206 is an 8 Kilobyte RAM. Further, it is to be understood that in alternate embodiments, the components of calculator 100 may be combined onto a single integrated circuit, e.g. processor 204 and main memory 206 may be combined on a single “system on a chip.”
[0046] Calculator 100 further includes a read only memory (ROM) 208 or other static storage device coupled to the bus 202 for storing static information and instructions for the processor 204 . In one particular embodiment, ROM 208 is a 128 Kilobyte ROM.
[0047] Calculator 100 may be coupled via the bus 202 to a display 102 , such as the above-described 96 * 64 pixel LCD, for displaying an interface to a user. An input area 104 , as described above with reference to FIG. 1 , is coupled to the bus 202 for communicating information, e.g. user-entered expressions and values, and command inputs to the processor 204 . An input device 108 , as described above with respect to FIG. 1 , is part of input area 104 and communicates direction information and command selections to processor 204 and controls cursor movement on the display 102 . This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y) allowing the device to specify positions in a plane.
[0048] The invention is related to the use of calculator 100 , such as the depicted calculator of FIG. 2 , to input and apply operations, e.g. expressions, to data and graph the results of operations by driving display 102 . According to one embodiment of the invention, data is stored and accessed from main memory 206 by calculator 200 in response to processor 204 executing sequences of instructions contained in main memory 206 in response to input received via input area 104 . A user interacts with the calculator 100 via a user interface displayed (as described below) on display 102 .
[0049] Execution of the sequences of instructions contained in the main memory 206 causes the processor 204 to perform the process steps described below. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with computer software instructions to implement the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.
[0050] According to an embodiment of the present invention, a user is able to input and evaluate fractions as user-entered expressions using a calculator. A user using calculator 100 manipulates number keys, i.e. 0-9 keys 122 , 124 , 126 , 130 , 132 , 134 , 138 , 140 , 142 , and 148 , to input one or more digits representative of the numerator for a fraction to be evaluated by processor 204 . The user then manipulates division key 128 to input a division symbol to processor 204 . After entering the division symbol, the user manipulates the number keys again to input one or more digits representative of the denominator for the fraction to be evaluated by processor 204 . Advantageously, fractions may be input in the same manner as written by a user on paper; thereby providing a more natural feel to the user using calculator 100 for fraction evaluation. Further, because fractions are input as written, users may more easily remember how to input fractions.
[0051] After input of the fraction is complete, the user manipulates execute key 146 to command processor 204 to evaluate the input fraction. After receipt of the evaluate command, processor 204 evaluates the fraction and determines if the fraction can be reduced or simplified, e.g. {fraction (4/8)}=½. If the fraction is reducible, processor 204 reduces the fraction and displays the reduced fraction to the user using display 102 . At the same time, processor 204 may also display the decimal equivalent of the fraction beside the fraction to the user using display 102 .
[0052] Calculator 100 will convert any user-entered expression using only integers, parenthesis, addition, subtraction, multiplication, and division into a fractional form. That is, 1+2/3(4+4/3) yields a fractional result of 41/9. It is to be understood that additional mathematical functions may be used in different embodiments.
[0053] Three examples are now provided to facilitate description of the operation of the calculator according to an embodiment of the present invention. With reference to FIG. 3 a, display 102 displays a user input of a fraction value 302 , i.e. “4/8”, by sequential manipulation of the four key 130 , the division key 128 , and the eight key 124 . The upright bar symbol, “|”, at the end of fraction value 302 indicates the cursor position to the user during editing/input of the user-entered expression, i.e. fraction value 302 .
[0054] After the user manipulates the execute key 146 , processor 204 evaluates the input fraction value 302 and drives display 102 to display the result 304 , i.e. “½=0.5”, to the user as depicted in FIG. 3 b. Result 304 includes a fraction version of the result separated by an equal sign from the decimal version of the result. It is to be understood that in alternate embodiments only one of the fraction and decimal version may be displayed.
[0055] With reference to FIG. 4 a, display 102 displays a user input of a compound fraction 306 , i.e. “2 and ⅔,” by sequential manipulation of the two key 140 , the addition key 152 , the two key, the division key 128 , and the three key 142 . The upright bar symbol, “|”, at the end of fraction value 306 indicates the cursor position to the user during editing/input of the user-entered expression, i.e. fraction value 306 .
[0056] After the user manipulates the execute key 146 , processor 204 evaluates the input fraction value 306 and drives display 102 to display the result 308 , i.e. “8/3=2.6666666666666”, to the user as depicted in FIG. 4 b. Result 308 includes a fraction version of the result separated by an equal sign from the decimal version of the result.
[0057] With reference to FIG. 5 a, display 102 displays a user input of fraction addition 310 , i.e. “⅘ plus ⅔,” by sequential manipulation of the four key 130 , the division key 128 , the five key 132 , the addition key 152 , the two key 140 , the division key 128 , and the three key 142 . The upright bar symbol, “|”, at the end of fraction addition 310 indicates the cursor position to the user during editing/input of the user-entered expression, i.e. fraction addition 310 .
[0058] After the user manipulates the execute key 146 , processor 204 evaluates the input fraction addition 310 and drives display 102 to display the result 312 , i.e. “22/15=1.46666666666”, to the user as depicted in FIG. 5 b. Result 312 includes a fraction version of the result separated by an equal sign from the decimal version of the result.
[0059] It is to be understood that in another embodiment, the fractional result may be displayed differently depending on if the value is greater than 1: (1) A/B or (2) A+B/C. For example, 2+4/5=14/5=2.8.
[0060] It will be readily seen by one of ordinary skill in the art that the present invention fulfills all of the objects set forth above. After reading the foregoing specification, one of ordinary skill will be able to affect various changes, substitutions of equivalents and various other aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by the definition contained in the appended claims and equivalents thereof.
[0061] For example, as depicted in FIGS. 1 and 3 - 5 , key labels may differ according to different embodiments, e.g. the division key 128 in FIG. 1 is represented by a slash mark whereas in FIGS. 3-5 the same key is represented by a ÷ symbol. The symbols are interchangeable and represent the same calculator functionality.
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A method of input and evaluation of fractions using a calculator is described. The calculator receives a user-entered expression including a fraction where the fraction is entered using a division key. The user-entered expression causes the calculator to evaluate the user-entered expression and display the evaluated user-entered expression. A calculator enabling input and evaluation of fractions includes means for receiving and displaying a user-entered expression including a fraction entered using a division key is described. The calculator further includes a processor for evaluating the user-entered expression using the means for evaluating the expression. The evaluated user-entered expression is displayed using a calculator display.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 753,743, filed July 10, 1985, now abandoned.
TECHNICAL FIELD
The present invention relates to the field of tubing manufacture and in particular to the field of automotive fuel and vapor transmission tubes.
BACKGROUND ART
Presently manufactured fuel lines for automobiles are made of relatively thick walled tubes of nylon 11 of 12. These materials provide the desired resistance to fuels such as gasoline, both leaded, unleaded and supra, diesel fuel, methanol, ethanol and sour gas. The nominal wall thickness of such tubes is approximately forty-thousandths of an inch (1 mm), since this provides the desired mechanical requirements of burst pressure (500 psig, minimum), sag resistance, kink resistance, cold impact resistance (at least 1 ft. lb. at minus 40° C.) and general handling durability. For fuel transport alone, however, a wall thickness of only one- to two-thousandths of an inch is actually necessary. The remainder of the wall thickness is necessary to protect and support the inner, fuel containing thickness, as well as to provide the necessary mechanical properties to the tube.
In order to properly route the fuel line throughout the vehicle, turns and bends are generally thermally preformed into the thick tube.
In the same manner, vapor tubes for recycling the fuel vapors in an automobile pollution control device must be resistant to the fuel as well as to combustion vapors. For this use, the tubing must be made of a fuel and combustion gas resistant material which, as with fuel lines, are generally thermally preformed.
One significant problem with the use of thermoplastic tubes (such as polyethylene, polypropylene, polyvinyl chloride or the like) is the relatively high gas vapor permeation of those materials. Therefore, in order to successfully transport fuel, tubes of those thermoplastic material must be surface treated to block or reduce such vapor transmission. Furthermore, no suitable method currently exists for surface coating the inner diameter of extruded thermoplastic tubing.
Also, for many applications, plastic tubing cannot prudently be used because of the work environment. Plastic tubing in the area of a welding operation is subject to rupture by weld splatter which may melt the tube wall. This occurrence could have disastrous effects if the tube is carrying a flammable substance, such as the fuel. Alternatively, to prevent against excessive abrasion or hot spots in localized areas, it is possible to provide this plastic tube with additional components, such as protective sleeves of rubber, metal or the like, in such localized areas. A disadvantage of this solution is that it is not always known where such problem areas will be encountered.
Therefore, thin walled metal tubing has been considered for this application, but it has not been found satisfactory due to its poor bending characteristics. A thin tube wall on an inner bend radius kinks very readily due to its inability to withstand a compressive load.
Flexible hose assemblies of plastic and metal for fuel lines are shown in the prior art. U.S. Pat. No. 2,787,289 to Press discloses a flexible line made of an extruded polytetrafluoroethylene tube which is surrounded by one or more layers of reinforcing wire braid of stainless steel and covered by a flexible tubular cover which is made of asbestos impregnated with a substantially oil proof material. This type of line, although flexible, is also resilient so that it is not capable of maintaining the shape into which it is bent. This is undesirable for many automotive applications since at least some type of semi-rigidity or shape holding property is necessary to maintain the line in the proper position.
In U.S. Pat. No. 4,327,248 to Campbell, there is disclosed a shielded electrical cable. The shield is made of a flexible metal tape with a coating of a copolymer of ethylene with a monomer having a reactive carboxyl group bonded to at least one of its sides. An adhesive is used to bond the coating to a flexible or semi-rigid non-olefinic polymeric material.
The present invention resolves the deficiencies of the prior art and provides a low cost plastic to metal bonded encasement which can be mechanically formed or bent to a predetermined configuration and which further can retain its shape after being formed or bent without kinking. Furthermore, this composite tube provides increased resistance to abrasion, hot spots and vapor permeation than those of the prior art, due to its ability to rapidly dissipate heat axially and radially along the composite tube.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to a bendable tubular article comprising a tubular liner made of petroleum resistant material in a sufficient thickness to contain fuel therein; a bendable metal strip surrounding the liner throughout its length in a sufficient thickness to form a bendable tubular composite having an unsupported self-sustaining shape when bent with sufficient heat dissipation capabilities to rapidly dissipate heat axially along the strip to prevent localized overheating of the article due to exposure to heat or sparks; an adhesive layer on at least one side of the metal strip; and a flexible jacket encasing the composite. The self-sustaining characteristic of the composite is greater than the flexibility of the liner or plastic jacket so that the article retains its shape after bending.
An alternate embodiment of the invention contemplates a tubular article comprising a liner made of petroleum resistant material of a thickness sufficient to contain petroleum fuel therein but less than about 0.5 mm; and an aluminum strip surrounding the liner throughout its length having a thickness of between about 0.2 and 0.4 mm and having at least two margins which meet to form a seam so as to form a bendable tubular composite having an unsupported, non-kinking self-sustaining shape when bent. This strip provides a fuel vapor permeation barrier as well as a thermal barrier which rapidly dissipates heat axially therealong. The article also includes an adhesive layer on at least the outer surface of the strip to adhere the margins forming the seam, and a plastic jacket encasing the aluminum strip and adhered thereto by the adhesive layer. The thickness ratio of the plastic jacket to the aluminum layer in the article is preferably between about 3.5:1 and 6.3:1.
The invention also relates to a bendable tubular article comprising a plastic liner made of petroleum resistant material; a bendable metal strip surrounding the liner throughout its length in a sufficient thickness for forming a bendable tubular composite having an unsupported, non-kinking self-sustaining shape when bent and to provide a barrier for protection against fuel vapor permeation and against heat due to the high heat capacity and thermal conductivity of the metal; an adhesive layer on each side of the metal strip; and a flexible plastic jacket encasing the composite and adhered thereto by the adhesive layer. Also, as above, the self sustaining characteristic of the composite is greater than the flexibility of the plastic jacket so that the article retains its shape when bent.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature, advantages, and various other additional features of the invention will appear more fully upon consideration of the illustrative embodiments now to be described in detail in connection with the accompanying drawing figures, where:
FIG. 1 is a partially cut-away perspective view of the fuel or vapor tube of the invention; and
FIG. 2 is a cross-sectional view of an embodiment of the invention having internal ribs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The tubing of the invention includes a thin metal barrier formed around a flexible nylon fuel or vapor tube component. A plastic jacket or casing, preferably polyethylene, may be used to surround the composite, which preferably has a thin metallic layer such as aluminum surrounding a thin petroleum resistant liner of nylon or the like. The metallic layer offers sufficient strength to dominate over the resiliency of the flexible liner and polyethylene jacket when the tubing is bent into a desired configuration. The tube thus has a formability characteristic and maintains the configuration into which it is formed. Also, the metal strip enables the liner to be bendable without kinking or buckling.
The presence of the plastic/metal covering over the actual conduit inner tube offers sufficient mechanical protection to safely allow a much smaller wall thickness of the inner liner. Thus, the inner liner can be made of an expensive engineering thermoplastic with the reduced wall thickness resulting in significant cost savings over comparable thick-walled tubing of the same material.
As shown in FIG. 1, the fuel or vapor tube includes on inner liner 1 made of any fuel resistant material. A preferred material is nylon 11 or 12, and is used in a thickness of approximately 0.05 to 0.5 mm (two to twenty mils). The liner 1 is cylindrical in shape. Longitudinally wrapped about the longitudinal axis of the liner is a metal strip 2 which forms a longitudinally extending lap joint 4. The metal strip 2, which is preferably made of aluminum, is approximately 0.2 to 0.4 (eight to sixteen mils) thick. Encasing the strip 2 is a flexible plastic casing 5. Extruded polyethylene or polypropylene or coatings of these materials are generally used, but flame retardant materials such as polyvinyl chloride, chlorinated polyethylene, or polychloroprene rubber can also be used for more critical applications.
The metal strip is preferred coated on both sides with an adhesive 3 capable of bonding to the outer jacket and, for some applications, the inner liner as well. When thermoplastic liner tubes and/or jackets are used, the adhesive is made from a copolymer of ethylene and a monomer having a reactive carboxyl group such as acrylic acid or an acrylic acid ester. An example of such a coated aluminum strip is currently manufactured under the "Zetabon" trademark by Dow Chemical Company. It is understood that the strip 2 is made of a sufficiently bendable metal which has the characteristic of staying in bent shape. Aluminum is preferred. Alternatively, the aluminum strip may be coated with adhesive 3 on one side only which would provide sufficient adhesion between the laps of the joint 4. A two-sided coating can be used, however, when adhesive bonds to the liner and jacket components are desired.
The adhesive is present at least on the outer surface of the tube formed by aluminum strip 2. However, the ethylene/acrylic copolymer described above does not bond to materials such as nylon as they are adhesively incompatible. Thus, when adhesion to a fuel tube of nylon is desired, a different adhesive layer must be used on the inner surface of the metal tube. The above adhesive, however, is compatible with polyethylene and is commercially available on an aluminum strip: therefore, an inner liner of polyethylene is preferred when bonding to the aluminum strip 2 through an adhesive 3 is desired. The casing is usually extruded onto the aluminum strip 2 after the strip is wrapped around the liner, but it can also be applied as a coating, if desired.
As shown in FIG. 2, the liner 1 may be provided with longitudinally extending ribs 6 for enhancing the rigidity and anti-buckling of the liner 1. The ribs 6 may extend longitudinally parallel to the axis of the liner or they may follow a helical path along the inner surface of the liner.
The tube is formed by continuously wrapping the adhesive coated aluminum strip around the extruded liner. The liner may be supplied from rolls or extruded as part of the manufacturing procedure. The aluminum strip has two longitudinal margins which overlap to form a longitudinally extending lap joint. The polyethylene casing is then extruded around the aluminum tube which has the liner already disposed within it. The heat of the extrusion process causes the polyethylene to bond to the adhesive and the adhesive in the lap joint to bond producing a securely attached aluminum tube and polyethylene jacket with a nylon liner disposed therein.
Alternately, the adhesive coated strip can be spirally wrapped around the liner before the casing is extruded or coated thereupon.
The liner tube of the invention has a significantly reduced wall thickness (at least 50% thinner, on the order of between about 2 and 20 thousandths or 0.05 to 0.5 mm) and is made of a fuel resistant plastic. This tube is encased with an adhesive coated aluminum tape, 0.2 to 0.4 mm thick. The metallic layer is then covered with an additional layer of plastic.
The invention has achieved the following characteristics at no significant cost change compared to 1 mm thick nylon 11 or 12 tubes:
______________________________________Burst Strength 30% improvement (typically, 1700 PSIG vs 1300 PSIG)Crush Resistance 95% improvement (typically, 72 lbs. vs 37 lbs.)Cold Impact Improved by approximately 20° F.Resistance to achieve a 1 ft. lb. valueSag Resistance Improved by a factor of at least 2.Kink Resistance Approximately the same______________________________________
It has also been determined that, with tubes of a 0.5 mm nylon 12 liner, 0.2 mm aluminum, and a polyethylene outer covering, the following plastic-to-metal ratios (i.e., for outer covering thickness to metal strip thickness) are highly desirable:
______________________________________Liner Tube I.D. Plastic-to-Metal Ratio______________________________________4.8 mm 3.5:1 to 4:16.3 mm 4.8:1 to 5.2:19.5 mm 5.6:1 to 6.3:1______________________________________
This ratio appears to give the optimum blend of bendability with kink resistance. It is also possible to utilize other plastic-to-metal ratios if the outer plastic jacket is made of a more elastomeric material or if the metal thickness is varied.
In another embodiment of the invention, the liner tube is made of an ordinary thermoplastic such as polyethylene polypropylene, polyvinyl chloride or the like. This construction allows both the inner tube and the outer jacket to bond to the adhesive coated tape and form an integral composite. This composite yields improved kink resistance if the same plastic-to-metal ratios decribed above are used or, if smaller ratios of plastic-to-metal are used, comparable kink resistance can be obtained, all while maintaining the mechanical bending, heat resistance and fuel transport characteristics of the composite tube.
The composite tube of the invention provides substantially superior resistance to heat and hot spots caused by weld spatter, sparks and the like. This is due to the thickness of the metal strip which rapidly transmits and dissipates heat axially along its length in both directions, thus quickly reducing and minimizing the size and intensity of any hot spots on the composite tube. This avoids rupture or failure of the plastic components of the tube by melting or burning in the areas of the hot spots.
Heat transfer per unit time is calculated using the following formula:
B.T.U./Hr.=KA(Δt/L
where
K=Materials thermal conductivity
A=Cross sectional area
Δt/L=Temperature gradient
The thermal conductivities of the composite tube materials are as follows:
K nylon =2.08
K polyethylene =3.42
K aluminum =1400
As can be seen with the magnitude of differences between the conductivities between the plastics and the aluminum, one can easily visualize what happens. As heat from an external source is transmitted through the outer layer of plastic, it confronts the aluminum layer. Due to its extremely high thermal conductivity, the aluminum transfers the heat very rapidly in axial directions. This rapid axial transfer spreads the heat over a greater area of the tube thus avoiding local hot spots which can burn or melt the plastic portions. This decreases the rate of actual temperature rise of any incremental point of the liner tube, thus increasing time to failure due to such hot spots. The heat transfer advantages are enhanced when fuel is flowing through the tube, since the moving fuel also helps to dissipate the heat.
While aluminum is the most preferred material for the metal strip, other metals such as copper, nickel, steel, stainless steel, and alloys thereof provide similar advantages in thermal conductivity compared to plastic.
The construction of the composite tube of the invention also allows other thermoplastics such as polyethylene, polypropylene, polyvinylchloride and the like to be used as the inner fuel-conducting tube. Polyethylene is a very desirable material for fuel delivery systems because it is lightweight, tough, chemically and environmentally resistant and inexpensive, but it is very poor regarding fuel vapor permeation. It has a permeation rate approximately 11000 to 12000 times greater than nylon. One variation of the plastic/metal composite fuel and vapor tube of this invention consists of the polyethylene liner tube embodiment. Since the metal layer of the invention totally encases the liner tube, all vapor permeation is blocked except for the minimal amount that can permeate through the overlap area of the wrap. This eliminates a secondary sulphonation or fluorination treatment of the surface of the polyethylene to reduce vapor permeation as is presently used with polyethylene fuel tanks.
The bonded, unitized construction of the plastic metal embodiment, when used in the proper ratios of plastic-to-metal as described above, achieves a tubular item that can be mechanically formed into the required three dimensional forms, in the same manner as with metallic tubing, while maintaining the necessary heat resistance, chemical corrosion and fuel resistance of plastic tubes.
While it is apparent that the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.
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A composite fuel and vapor tube having increased heat resistance with a composite wall having a relatively thin nylon liner, a metal strip about the liner and having a longitudinal seam, the tube being encased within a polyethylene jacket. The line thus formed has increased resistance to heat, abrasion and various fuels, is bendable and is capable of maintaining its shape after bending or forming operations.
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FIELD OF THE INVENTION
[0001] This invention relates to internal combustion engines. More particularly it relates to internal combustion engines with an opposed piston configuration.
BACKGROUND
[0002] WO2008/149061 (Cox Powertrain) describes a 2-cylinder 2-stroke direct injection internal combustion engine. The two cylinders are horizontally opposed and in each cylinder there are opposed, reciprocating pistons that form a combustion chamber between them. The pistons drive a central crankshaft between the two cylinders. The inner piston (i.e. the piston closer to the crankshaft) in each cylinder drives the crankshaft through a pair of parallel scotch yoke mechanisms. The outer piston in each cylinder drives the crankshaft through a third scotch yoke, nested between the two scotch yoke mechanisms of the inner piston, via a drive rod that passes through the centre of the inner piston. The drive rod has a hollow tubular form and fuel is injected into the combustion chamber by a fuel injector housed within the drive rod. The wall of the drive rod has a series of circumferentially spaced apertures through which the fuel is projected laterally outwardly into the combustion chamber.
SUMMARY
[0003] The present invention is generally concerned with opposed piston internal combustion engines having a fuel injector disposed in each cylinder to inject fuel directly into a combustion chamber formed between the two opposed, reciprocating pistons in the cylinder. The present invention is a development of the configuration of the engine described in WO2008/149061 and seeks to offer embodiments that retain the benefits of that earlier engine, namely a very compact and efficient engine with a high ratio of power output to weight, whilst offering yet further benefits.
[0004] In a first aspect, the present invention provides an internal combustion engine comprising at least one cylinder, a pair of opposed, reciprocating pistons within the cylinder forming a combustion chamber therebetween, and at least one fuel injector disposed at least partly within the cylinder, the fuel injector having a nozzle that is positioned within the combustion chamber and through which the fuel is expelled into the combustion chamber, wherein the nozzle is exposed directly within the combustion chamber.
[0005] By exposing the nozzle of the injector directly to the combustion chamber (i.e. physically locating the nozzle within the combustion chamber) at the point in time of injection, as opposed to the prior art arrangement discussed above in which the injector is housed within the central drive rod, the need to inject fuel through apertures in a wall is avoided. This leads to a simpler construction, improved fuel injection, air motion and combustion characteristics, and makes it possible to use more conventional injectors.
[0006] Especially in cases where only a single injector is employed, the injector is preferably at or close to the central axis of the cylinder/piston. The injector nozzle will typically be at one end of the injector (the end that projects into the cylinder).
[0007] The concepts of the invention are applicable to compression ignition (CI & HCCI) engines and also spark ignition (SI) and spark assisted ignition engines. In For a CI embodiment, the fuel will normally be injected into the combustion chamber at or close to the point in the engine cycle where the two pistons are at their closest and the combustion chamber volume is at its smallest. The nozzle of the injector will be positioned to be located within the combustion chamber at this point in the cycle. For HCCI and SI variants, injection is likely to be much earlier in the cycle and possibly as early as intake port opening.
[0008] The nozzle of the fuel injector preferably protrudes outwardly from an end face of a housing of the injector in the direction of the cylinder axis. The nozzle may have a series of apertures around its periphery from which the fuel is expelled generally radially into the combustion chamber. Preferably there is a valve (e.g. a needle valve) in the nozzle that is operable to control a pressurised supply of fuel to the apertures. The supply of fuel can be controlled in a conventional manner.
[0009] In some embodiments, the fuel injector is fixed at one end of the cylinder, typically to a fixed, structural component, and projects into the cylinder from that end, along or parallel to the central axis of the cylinder, to locate the injector nozzle in a fixed position that is within the combustion chamber throughout the engine cycle. In this case, the injector extends through the piston closest to the end of the cylinder from which the injector projects and this piston is configured to reciprocate along a housing of the injector.
[0010] In an alternative arrangement, the fuel injector moves with one of the pistons. It may be fixed to the piston to move with it through the whole stroke of the piston or, alternatively, may move with the piston for only part of its stroke.
[0011] Typically, the motion of the pistons will drive a crankshaft positioned at one end of the cylinder, the piston closest to the crankshaft end of the cylinder being designated the “inner piston” and the piston furthest from the crankshaft being designated the “outer piston”. The or each fuel injector may be associated with either the outer piston or the inner piston.
[0012] Especially in the case where the injector is fixed and the associated (e.g. outer) piston reciprocates along the injector housing, the injector is preferably cooled. Cooling can be provided, for example, by a supply of a cooling fluid (e.g. engine oil, engine cooling fluid, raw water cooling such as sea water, or fuel) to the interior of the injector housing.
[0013] In the case where one of the pistons reciprocates on the injector housing, the outer surface of the injector housing preferably provides a running surface along which the piston can slide. A sealing system, for example one or more sealing rings, is provided between the piston and the running surface of the injector housing to restrict the escape of combustion gases and the ingress of lubricating oil to the combustion chamber.
[0014] The injector may be fixed to an outer part of the engine structure by any suitable coupling. In some cases it may be desirable to use a coupling that allows the injector to self-align itself parallel to the centreline of the cylinder and to accommodate tolerances and thermal distortion of the piston it is associated with. For example, an Oldham coupling may be used (this type of coupling allows the injector to move in a plane perpendicular to its axis, to allow the desired alignment, whilst preventing movement along its axis).
[0015] In the case where the pistons drive a crankshaft, any suitable drive linkage may be used to translate the opposed reciprocating motion of the pistons into a rotary motion of the crankshaft. In preferred embodiments, however, scotch yoke mechanisms are used. Where scotch yoke mechanisms are used, as minimum it would be necessary to have at least one scotch yoke through which the inner piston (i.e. the piston closest to the crankshaft) drives the crankshaft and at least one scotch yoke through which the outer piston drives the crankshaft. However, to avoid undesirable unbalanced forces on the outer piston, whilst avoiding the need for a central drive rod through the cylinder, it is more preferable for the outer piston to drive the crankshaft through a pair of scotch yokes, one to either side of the cylinder connected to the outer piston by respective connection members on opposite sides of the cylinder. The connection members may, for example be rods or sleeve portions within the cylinder, at or close to the periphery of the cylinder. More preferably, the connection members are external to the cylinder. They may comprise, for example, one or more drive rods.
[0016] In a second aspect, the present invention provides an internal combustion engine comprising at least one cylinder, a pair of opposed, reciprocating pistons within the cylinder forming a combustion chamber therebetween, and at least one fuel injector disposed on or parallel with the central axis of the cylinder configured to inject fuel into the combustion chamber, wherein the pistons drive a crankshaft disposed at one end of the cylinder via respective drive linkages, the drive linkage for the piston furthest from the crankshaft (the ‘outer’ piston) being external to the cylinder.
[0017] By providing the linkage for the outer piston external to the cylinder, the need for any drive rods passing through the inner cylinder is avoided. The absence of a drive rod or rods passing through the combustion chamber also allows for a more straightforward, conventional combustion chamber design, simpler cooling of the inner piston, elimination of a blowby path to the crankcase and elimination of heat losses to the drive rod. The use of an external linkage also means that an injector can be located centrally with respect to the piston (or close to the centre of the piston) without obstruction.
[0018] As with embodiments of the first aspect above, any suitable drive linkage may be used to translate the opposed reciprocating motion of the pistons into a rotary motion of the crankshaft but scotch yoke mechanisms are preferred. For instance, the outer piston may drive the crankshaft through a pair of scotch yokes, one to either side of the cylinder, connected to the outer piston by the external drive linkage. The external drive linkage may comprise connection members to either side of the cylinder, for example one or more drive rods.
[0019] Whilst a single cylinder configuration is possible preferred engines in accordance with embodiments of the first and/or second aspects of the invention comprise multiple cylinders, for example two cylinders, four cylinders, six cylinders, eight cylinders or more.
[0020] Where multiple cylinders are used, various configurations are possible that may offer different benefits in terms of balance of forces, overall shape and size of the engine, etc. Exemplary configurations include (but are not limited to) coaxial opposed pairs of cylinders (e.g. ‘flat two’, ‘flat four’, etc), ‘straight’ configurations with all of the cylinders side-by-side, ‘U’ configurations with two straight banks of cylinders side-by-side (e.g. ‘square 4’), ‘V’ configurations and ‘W’ configurations (i.e. two adjacent banks of ‘V’ configured cylinders) and radial configurations. Depending on the configuration, the multiple cylinders may drive a single crankshaft or a plurality of crankshafts. Typically ‘flat’, ‘straight’, ‘V’ and radial configurations will have a single crankshaft, whereas ‘U’ and ‘W’ configurations will have two crankshafts, one for each bank of cylinders. In some embodiments of the invention it is possible to use two engine units (each with one or more cylinders) with contra-rotating crankshafts that drive a shared output shaft through a bevel gearbox. This arrangement has the advantage that torque recoil effects are balanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] An embodiment of the invention is now described by way of example, with reference to the accompanying drawings in which:
[0022] FIG. 1 is a cross-section through a flat four engine configuration according to an embodiment of the present invention;
[0023] FIG. 2 is a cross-section of the engine of FIG. 1 along line z-z in FIG. 1 ;
[0024] FIG. 3 is a cross-section of the engine of FIG. 1 along the centre line of the lowermost opposed pair of cylinders as shown in FIG. 1 ;
[0025] FIG. 4 is an isometric view of the engine of FIG. 1 ;
[0026] FIG. 5 is a simplified plan view of key components (in an assembled form) of the engine of FIG. 1 , including the crankshaft, scotch yokes, pistons, drive rods and fuel injectors;
[0027] FIG. 6 is a simplified isometric view of the key components shown in FIG. 5 ; and
[0028] FIGS. 7( a ) to 7 ( m ) show snapshots of the engine of FIG. 1 through one complete revolution of the crankshaft at 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 272°, 300°, 330°, 360° respectively, starting from the point in the cycle of minimum combustion chamber volume (referred to in the following for convenience as lop dead centre' or ‘TDC’—this terminology (TDC) is used because the skilled person will recognise that is the analogous point in the operating cycle for a more conventionally disposed engine) of the cylinder seen in the bottom left of the figure.
DETAILED DESCRIPTION
[0029] The embodiment used here to exemplify the invention is a 2-stroke, direct injection, four cylinder engine. The engine is configured with two horizontally opposed pairs of cylinders. One pair of cylinders is arranged alongside the other to give a ‘flat four’ configuration. As probably best seen in FIG. 4 , this configuration provides the engine with a low-profile overall envelope that will be advantageous for some applications, for example for use as an outboard marine engine. Engines in accordance with embodiments of the invention can also be used as propulsion or power generation units for other marine applications, as well as for land vehicles and aircraft.
[0030] In more detail, looking initially at FIGS. 1 to 3 , the engine 10 comprises comprises four cylinders 12 arranged about a central crankshaft 14 , mounted for rotation about axis z-z (see FIG. 1 ). The two cylinders, one either side of the crankshaft, to the bottom of FIG. 1 are one opposed pair of cylinders and the two other cylinders, towards the top of FIG. 1 are the other pair of opposed cylinders.
[0031] Within each cylinder there are two pistons, an inner piston 16 and an outer piston 18 . The two pistons in each cylinder are opposed to one another and reciprocate in opposite directions, in this example 180 degrees out of phase.
[0032] Each piston has a crown 20 , 22 , the crowns of the two pistons facing one another, and a skirt 24 , 26 depending from the crown. In this example, the crown 26 of the outer piston is substantially flat whereas the crown 24 of the inner piston has an annular depression with a generally tear-drop shaped cross-section. At top dead centre, when the piston crowns are closest to one another (and very nearly touching), the opposed crowns 24 , 26 define a toroidal combustion chamber 28 into which the fuel is injected.
[0033] As explained in more detail further below, when the pistons are at a position in their cycle where they are spaced furthest from one another to define a maximum contained volume within the cylinder (“bottom dead centre”), as seen for the top left and bottom right cylinders in FIG. 1 , the piston crowns are withdrawn sufficiently far to uncover intake ports 30 and exhaust ports 32 , towards the inner and outer ends of the cylinder respectively. As the pistons 16 , 18 move towards one another in the compression stroke of the cycle, the piston skirts cover and close the ports, the skirt 24 of the inner piston 16 closing the intake port 30 and the skirt 26 of the outer piston 18 closing the exhaust port 32 . As best seen in FIGS. 1 and 2 , the exhaust ports 32 have a greater axial extent (i.e. dimension in the direction of the longitudinal axis of the cylinder) than the intake ports so that the exhaust ports open sooner than and stay open longer than the intake ports, to aid scavenging of the cylinder.
[0034] Associated with each cylinder 12 is a fuel injector 34 . The fuel injector 34 has a cylindrical housing 36 with an injector nozzle 38 at one end. Fuel is supplied under pressure to the nozzle, through the injector housing, in a conventional manner. The nozzle 38 projects from an end face of the injector housing 36 , and has a series of apertures equally spaced around its periphery through which fuel is injected in a generally radial direction. The nozzle is opened and closed by a needle valve (not shown). When the needle valve is open fuel is injected under pressure through the apertures. The opening and closing of the needle valve can be controlled in a conventional manner. In use, the injector housing may be cooled by a supply of a coolant fluid, which may be the fuel itself or an engine coolant for example (although this may not be required in some cases).
[0035] The fuel injector 34 is mounted along the central axis of the cylinder 12 . In this example, an outer end of the injector 34 is fixed to a component 40 at the outer end of the cylinder (i.e. the end of the cylinder opposite the crankshaft 14 ). The injector 34 extends through a central opening 42 in the outer piston crown 22 to locate the inner end of the injector, from which the nozzle 38 projects, centrally in the cylinder 12 . More specifically, as seen in the bottom left and top right cylinders in FIG. 1 and the left hand cylinder in FIG. 2 , when the pistons 16 , 18 are at top dead centre, the nozzle 38 of the fuel injector 34 is directly within the toroidal combustion chamber 28 and fuel can be injected laterally from the nozzle 38 into the combustion chamber 28 .
[0036] In the central injector arrangement described here the injector 34 is fixed in position and, during operation of the engine 10 , the outer piston 18 travels along the outside of the injector housing 36 . Appropriate seals 44 are provided around the periphery of the opening 42 in the outer piston crown 22 to maintain a seal between the piston crown 22 and the injector housing 36 as the piston 18 reciprocates back and forth along the injector housing 36 , to avoid or at least minimise leakage of pressurised gases from within the cylinder and to prevent ingress of oil to the combustion chamber.
[0037] The fuel injectors 34 themselves can be of conventional construction, save that the outer surface of the injector housing is configured to allow sliding contact with the piston 18 . Typically the fuel spray will take the form of a plurality of radial jets spaced around a nozzle of the injector and controlled by a single valve arrangement (e.g. a needle valve arrangement comprising a needle and seat that the needle engages to close the valve). The fuel injector may, for example, be a conventional injector housed in a sleeve that provides the outer housing along which the piston slides. In this arrangement, the nozzle of the conventional injector would protrude from one end of the sleeve. The injector may be surrounded by a coolant within the sleeve, although this may not be required in some embodiments. Alternatively, a bespoke injector may be used, having a body that provides a running surface on its outside, and optionally cooling within, although in this case the internal components may still be conventional.
[0038] In this example, the pistons 16 , 18 drive the crankshaft 14 through four scotch yoke arrangements 50 , 52 , 54 , 56 , mounted on respective eccentrics 58 on the crankshaft 14 . The connections between the pistons 16 , 18 and the scotch yokes 50 , 52 , 54 , 56 , especially those for the outer pistons 18 , are best seen in FIGS. 5 and 6 . In this example, the scotch yokes are shared by multiple pistons, as explained in more detail below, to minimise the number of scotch yokes that and hence to minimise a required length of the crankshaft providing a more compact design.
[0039] The directions/relative positions (“upper”, “lower”, “left”, “right”, etc) used below and elsewhere herein refer to the relative positions of components as drawn and should not be taken to imply any particular orientation of the engine, or positions on the engine components in space.
[0040] Looking at FIG. 5 , the four scotch yokes 50 , 52 , 54 , 56 can be seen connected to the crankshaft 14 extending vertically through the middle of the figure.
[0041] A first scotch yoke 50 (at the top of FIG. 5 ) is connected adjacent one end of the crankshaft 14 . Drive rods 60 connect this yoke 50 to the outer pistons 18 a, 18 b of the two upper cylinders 12 a, 12 b (as seen in FIG. 5 ). As best seen in FIG. 6 , there are two drive rods 60 per outer piston 18 a, 18 b, secured to adjacent corners (the uppermost corners in FIG. 1 , towards the top end of the crankshaft) of a connection plate 72 a, 72 b that is itself secured to the piston 18 a, 18 b. The connection plate 72 a, 72 b extends beyond the outer circumference of the cylinder 12 so that the drive rods 60 extend from the corners of the plate 72 a, 72 b along the outside of the cylinders (i.e. externally).
[0042] A second scotch yoke 52 is positioned between the two upper cylinders 12 a, 12 b and is connected to the inner pistons 16 a, 16 b of these two cylinders by respective drive rods 62 (most clearly seen in FIG. 1 ). Drive rods 62 extend from the centres of the inner pistons 16 a, 16 b to their connections with the scotch yoke 52 . Advantageously, the second scotch yoke 52 is also connected to the lower pair of outer pistons 18 c, 18 d by drive rods 64 . Similarly to drive rods 60 discussed above, there are two of these rods 64 per piston that extend from adjacent corners of respective connection plates 72 c, 72 d (in this case the two corners that are closest to the mid-point of the crankshaft) that are secured to the outer ends of the outer pistons 18 c, 18 d.
[0043] A third scotch yoke 54 is positioned between the two lower cylinders 12 c, 12 d and is connected to the inner pistons 16 a, 16 b of these two cylinders by respective drive rods 66 (again, most clearly seen in FIG. 1 ). Drive rods 66 extend from the centres of the inner pistons 16 c, 16 d to their connections with the scotch yoke 54 . Similarly to the second scotch yoke 52 , this third scotch yoke is additionally connected to the upper pair of outer pistons 18 a, 18 b by drive rods 68 . There are two of these rods 68 per piston and they extend from the other two adjacent corners of connection plates 72 a, 72 b (opposite the corners from which the drive rods 60 extend, i.e. the two corners that are closest to the mid-point of the crankshaft).
[0044] The fourth scotch yoke 56 is shown at the lower end of the crankshaft 14 in FIG. 5 . This yoke 56 is connected to the lower pair of outer pistons 18 c, 18 d by another pair of drive rods 70 for each piston 18 c, 18 d. These rods are connected to respective lower corners (i.e. the corners opposite those to which the drive rods 64 are connected) of the connection plates 72 c, 72 d fixed to the lower pair of outer pistons 18 c, 18 d.
[0045] The connection plates 72 are shaped so that the drive rods connected to their corners closest to the mid-point of the crankshaft lie parallel and alongside one another without interfering with one another during motion of the pistons.
[0046] Thus, each of the upper outer pistons 18 a, 18 d is connected to the first scotch yoke 50 by a first pair of drive rods 60 and to the third scotch yoke 54 by a second pair of drive rods 68 . Each of the lower outer pistons 18 c, 18 d are connected to the fourth scotch yoke 56 by a first pair of drive rods 70 and to the second scotch yoke 52 by a second pair of drive rods 64 . The upper inner pistons 16 a, 16 b are connected to the second scotch yoke 52 by respective central drive rods 62 and the lower inner pistons 16 c, 16 d are connected to the third scotch yoke 54 by respective central drive rods 66 .
[0047] Put another way, the first scotch yoke 50 is driven by the upper outer pistons 18 a, 18 b, the second scotch yoke 52 is driven by the upper inner pistons 16 a, 16 b and the lower outer pistons 18 c, 18 d, the third scotch yoke 54 is driven by the lower inner pistons 16 c, 16 d and the upper outer pistons 18 a, 18 b and the fourth scotch yoke 56 is driven by the lower outer pistons 18 c, 18 d.
[0048] As noted above, this sharing of scotch yokes between inner and outer pistons reduces the number of scotch yokes that would otherwise be required, minimising the required length of the crankshaft.
[0049] The cross-linking, via the scotch yokes, of inner pistons in one opposed pair of cylinders with outer pistons in the other opposed pair of cylinders also helps to stabilise the pistons within the cylinders, resisting unwanted rotation of the pistons about axes perpendicular to the central axis of the cylinder. This arrangement in also serves to locate the yoke sliders, avoiding a requirement for other features (such as tracks or cylindrical running surfaces) to locate them.
Operation of the Engine
[0050] FIG. 7 illustrates the operation of the engine over one complete crankshaft rotation. Specifically, FIGS. 7( a ) to 7 ( m ) illustrate the piston positions at 30° increments.
[0051] FIG. 7( a ) at 0° ADC shows the engine at a crankshaft position of 0° (arbitrarily defined as TDC in the bottom left cylinder 12 c of FIG. 5) . At this position, the bottom left outer piston 18 c and the bottom left inner piston 16 c are at their point of closest approach. At approximately this angle of crankshaft rotation, in the exemplified direct-injection engine, a fuel charge would be injected into the bottom left cylinder and combustion would begin. At this point, the exhaust and intake ports 32 , 30 of the bottom left cylinder are completely closed by outer and inner pistons respectively.
[0052] In FIG. 7( b ) at 30° ADC, the inner and outer pistons of the bottom left cylinder are moving apart at the beginning of the power stroke.
[0053] In FIG. 7( c ) at 60° ADC, the bottom left cylinder continues its power stroke, with the two pistons equal but opposite velocities.
[0054] In FIG. 7( d ) at 90° ADC, the bottom left cylinder continues its power stroke.
[0055] In FIG. 7( e ) at 120° ADC, the outer piston of the bottom left cylinder has opened exhaust ports 32 , while the intake ports remain closed. In this “blowdown” condition, some of the kinetic energy of the expanding gases from the combustion chamber can be recovered externally if desired by a turbocharger (“pulse” turbocharging) e.g. for compressing the next.
[0056] In FIG. 7( f ) at 150° ADC, the inner piston of the bottom left cylinder has opened the intake ports 30 and the cylinder is being uniflow scavenged.
[0057] In FIG. 7( g ) at 180° ADC, the inner and outer pistons of the bottom left cylinder are causing both intake and exhaust ports 30 , 32 to remain open and uniflow scavenging continues. The pistons are at bottom dead centre.
[0058] In FIG. 7( h ) at 210° ADC, in the bottom left cylinder, both sets of ports 30 , 32 remain open and uniflow scavenging continue.
[0059] In FIG. 7( i ) at 240° ADC, in the bottom left cylinder, the inner piston has closed the intake ports 30 , while the exhaust ports 32 remain partially open. In other embodiments the exhaust port may open after and/or close before the inlet port opens/closes. It may also be desirable in some applications for the port timing to be asymmetric, for example by using a sleeve valve to control the opening and closing of the ports.
[0060] In FIG. 7( j ) at 270° ADC, in the bottom left cylinder, the outer piston has closed the exhaust ports 32 and the two pistons are moving towards each other, compressing the air between them.
[0061] In FIG. 7( k ) at 300° ADC, in the bottom left cylinder, the pistons continue the compression stroke.
[0062] In FIG. 7( l ) at 330° ADC, the bottom left cylinder is nearing the end of the compression stroke and the “squish” phase is beginning. This is where the outer, annular, opposite faces of the inner and outer pistons begin to expel air from between them.
[0063] In FIG. 7( m ) at 360° ADC, the position is the same as in FIG. 3( a ). The bottom left cylinder has reached the TDC position, where the pistons are at their position of closest approach. The “squish” phase continues, causing an intensifying “smoke ring” effect to be superimposed on the already existing cylinder axis swirl caused by partially tangential intake ports. These compound gas motions will be at their most intense at TDC when the combustion chamber most nearly resembles a toroid and is of minimum volume. At this point, multiple radial fuel sprays emanate from the central fuel injector, reaching almost all of the available air and causing very efficient combustion. Injection need not commence exactly at minimum volume and in some embodiments injection timing may change as a function of speed and/or load.
[0064] The specific angles and timings depend on the crankshaft geometries and port sizes and locations; the above description is intended solely to illustrate the concepts of the invention.
[0065] The skilled person will appreciate that various modification to the specifically described embodiment are possible without departing from the invention. The fuel injector might project from the inner end of the cylinder, with the inner piston sliding on the injector. In this case the combustion bowl would likely be formed in the outer piston. The skilled person will also appreciate that embodiments of the invention may be 2-stroke or 4-stroke and may be compression ignition or spark ignition.
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An internal combustion engine comprising at least one cylinder and a pair of opposed, reciprocating pistons within the cylinder forming a combustion chamber therebetween. The engine has at least one fuel injector disposed at least partly within the cylinder, the fuel injector having a nozzle that is positioned within the combustion chamber and through which the fuel is expelled into the combustion chamber, wherein the nozzle is exposed directly within the combustion chamber.
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This application is a continuation of application Ser. No. 08/089,591 filed Jul. 12, 1993 (now abandoned), which is a continuation of Ser. No. 07/808,809, filed Dec. 18, 1991, (now abandoned).
BACKGROUND OF THE INVENTION AND THE RELATED ART STATEMENT
The present invention relates to a rare earth oxide superconducting material and a process for producing said superconducting material. More particularly, the present invention relates to a rare earth oxide superconducting material which comprises grains of an oxide superconducting material represented by REBa 2 Cu 3 O y (RE is Y, Gd, Dy, Ho, Er or Yb) and at least one element selected from Rh and Pt, uniformly dispersed in said grain and which gives a high critical current density even in a highly magnetic field, as well as to a process for producing said superconducting material by melting the raw materials.
Oxide superconducting materials have high critical temperatures and vigorous researches are under way in order to put them into practical use. In obtaining an oxide superconducting material as a bulk material, sintering has heretofore been used generally. The oxide superconducting materials obtained by sintering have such a microstructure as the grains: are fine and a number of grain boundaries exist inside; when observed under an optical microscope, they show, in some cases, the presence of cracks along the grain boundaries and impurities at the grain boundaries. In these oxide superconducting materials obtained by sintering, the superconducting grains are combined with each other by a weak-link, and the critical current density (Jc) is controlled by the weak-link, making it impossible to obtain a high Jc.
Meanwhile, in superconducting materials of single crystal structure, it is known that no grain boundary problems as mentioned above exist and that a high Jc is obtained even in a highly magnetic field. Hence, it was investigated to allow the superconducting material of microstructure obtained by sintering to approximate a single crystal structure and it was proposed to disperse microstructure particles of superconducting phase in a single crystal phase to fix the magnetic flux line coming into, that is, to form pinning centers. For example, a melting process represented by a MTG process (a Melt Textured Growth process) was proposed. In the MTG process, a rare earth oxide superconducting material, for example, is slowly cooled generally from the lncongruent melting point of 123 phase [REBa 2 Cu 3 O y (RE is a rare earth element including Y)] to give rise to a peritectic reaction between 211 phase (RE 2 BaCuO 5 ) and liquid phase to cause crystal growth; the 211 phase exists inside the crystals because of incomplete reaction after growth and acts as pinning centers; as a result, the rare earth oxide superconducting material obtained shows a high Jc even in a magnetic field. The oxide superconducting material obtained by the MTG process, however, has various disadvantages in that the particles of the 211 phase are large and their distribution is non-uniform and that cracks exist along the direction of crystal growth.
Also, a CG process (a Quench and Melt Growth process) was proposed in Japanese Patent Application Laid-Open No. 153803/1990, as an improved process for the MTG process. In tile QMG process, raw materials for rare earth oxide superconducting material are subjected to melting, quenching and solidification to obtain an intermediate comprising a Ba-Cu oxide phase and an Y 2 O 3 phase or the like of 50 μm or less dispersed in said oxide phase, or Y 2 O 3 and a Ba-Cu oxide are mixed to obtain a plate-like material of 5 mm or less in thickness or a linear material; the intermediate or the plate-like or linear material is heated at the incongruent melting point of 123 phase to convert to a semi-molten state and then is cooled slowly from that temperature at a given cooling rate to give rise to a peritectic reaction between 211 phase and liquid phase to grow a 123 phase in which a 211 phase of 20 mm or less is finely and uniformly dispersed. According to the disclosure in the above document, the superconducting material obtained by the QMG process exhibits a very high pinning effect and gives an excellent Jc in a highly magnetic field. Further, a MPMG process (a melt powder and melt growth process) was proposed. In the MPMG process, a material obtained by melting, quenching and solidification according to the QMG process is ground for higher shapability and the obtained superconducting material is said to give the same high Jc as In the QMG process.
The QMG process and the MPMG process, as compared with the melt processing, can exhibit a high pinning effect and give an excellent Jc, but must conduct melting in two stages making the procedure complex.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a rare earth oxide superconducting material showing, similarly to the oxide superconducting materials obtained by the QMG process and tile MPMG process, a very high pinning effect and an excellent Jc in a highly magnetic field.
Another object of the present invention is to provide a process for producing a rare earth oxide superconducting material showing an excellent Jc, by a melt processing employing a simple procedure.
According to the present invention, there is provided a rare earth oxide superconducting material represented by REBa 2 Cu 3 O y (RE is Y, Gd, Dy, flo, Er or Yb), comprising oxide grains and at least one element selected from Rh and Pt, contained in said grains in a proportion of 0.01-5% by weight (in terms of element) based on the rare earth oxide superconducting material.
According to the present invention, there is also provided a process for producing a rare earth oxide superconducting material represented by REBa 2 Cu 3 O y (RE is Y, Gd, Dy, Ho, Er or Yb), comprising oxide grains and at least one element :selected from Rh and Pt, contained in said grains in a proportion of 0.01-5% by weight (in terms of element) based on tile rare earth oxide superconducting material, which process comprises adding, to powders containing RE. Ba and Cu [these powders are raw materials for REBa 2 Cu 3 O y , at least one element selected from Rh and Pt or at least one compound thereof so that the addition amount becomes 0.01-5% by weight (in terms of element) based on the rare earth oxide superconducting material to be finally obtained, shaping the resulting mixture, subjecting the shaped material to a heat treatment at a temperature equal to or higher than the lncongruent melting point of the REBa 2 Cu 3 O y oxide superconducting material, and subjecting the resulting material to slow cooling and a heat treatment.
In the present invention, at least one element selected from Rh and Pt or at least one compound thereof is added to raw materials for REBa 2 Cu 3 O y oxide superconducting material, whereby the resulting oxide superconducting material contains Rh and/or Pt in a uniformly dispersed state, shows a high Jc similarly to the oxide superconducting materials obtained by the QMG process and the MPMG process, and is uniform in every portion and exhibits excellent superconductivity.
The process for producing a rare earth superconducting material according to the present invention conducts melting in one stage as in the conventional melting process and can provide a rare earth oxide superconducting material having excellent superconductivity.
The REBa 2 Cu 3 O y oxide superconducting material according to the present invention can be obtained by adding given amount(s) of platinum group element(s) or compounds(s) thereof to raw material powders and then subjecting the resulting mixture to melting, slow cooling and heat treatment in substantially the same manners as in the conventional melt processing. The REBa 2 Cu 3 O y oxide superconducting material containing given amount(s) of platinum group element(s) in a uniformly dispersed state, obtained according to the present invention exhibits uniform superconductivity in every portion, as compared with the rare earth oxide superconducting materials lacking in overall uniformity, obtained by the conventional melt processing, and gives a high Jc even in a highly magnetic field similarly to the rare earth oxide superconducting materials obtained by the conventional melt processing. These features, although tile reasons are not clear, are brought about by the use of given amount(s) of platinum group element(s) or compound(s) thereof as a material and have been found by the present inventors for the first time.
BRIEF DESCRIPTION OF TIlE DRAWINGS
FIG. 1 is a microphotograph showing the microstructure of the crystals of an example of the rare earth oxide superconducting material of the present invention.
FIG. 2 is a microphotograph showing the microstructure of the crystals of a rare earth oxide superconducting material obtained by the conventional process.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is hereinafter described in detail.
The REBa 2 Cu 3 O y oxide superconducting material of the present invention has a multi-layered perovskite structure containing, as a rare earth element (RE), Y, Gd, Dy, Ho, Er or Yb and is represented by, for example, YBa 2 Cu 3O 7 .
The raw material powders containing RE, Ba ad Cu elements used for obtaining the REBa 2 Cu 3 O y oxide superconducting material have no particular restriction as long as they are a mixed oxide powder of an oxide of RE (i.e. Y, Gd, Dy, Ito, Er or Yb), a carbonate or oxide of Ba and an oxide of Cu, a calcined powder obtained from said mixed oxide powder, a frit powder obtained from said mixed oxide powder, or the like, in which powder the individual raw materials are contained so as to constitute, after firing, REBa 2 Cu 3 O 3 and RE 2 BaCuO 6 . The particle diameters of the raw material powders have no particular restriction, either, but is generally 2-20 μm.
In the present invention, at least one platinum group element selected from Rh and Pt or at least one compound thereof (e.g. PtO 2 ) is added to the above raw material powders in a proportion of 0.01-5% by weight (in terms of element) based on the REBa 2 O 3 O y oxide superconducting material to be obtained finally, to obtain a mixed powder. Addition of a single metal powder of Rh or Pt is generally preferred. When the platinum group element or compound thereof is added in a proportion less than 0.01% by weight (in terms of element) based on the REBa 2 O 3 O 6 oxide superconducting material to be obtained finally, no effect is obtained by the addition. When the addition proportion is more than 5% by weight, impurities appear in a larger amount and an undesirable effect is incurred. The platinum group element or compound thereof is added to the raw material powders for rare earth oxide superconducting material, preferably in the form of powder for easier mixing. Addition in a fine powder having particle diameters of about 20 μm or less is preferred generally. When the particle diameters are more than about 20 μm, the powder remains in the final product as agglomerates, reducing the homogeneity of the final product. The reduction in homogeneity causes fluctuation of superconductivity.
The mixed powder consisting of the raw material powders and tile platinum group element or compound thereof is thoroughly mixed to uniformly disperse the element or compound in the raw material powders; the resulting powder is shaped into a desired shape; the shaped material is heated to a temperature equal to or higher than the incongruent melting point of tile REBa 2 Cu 3 O y oxide superconducting material to be obtained finally; the resulting material is cooled slowly as in the known melting process and then subjected to a heat treatment in an oxygen atmosphere to obtain a rare earth oxide superconducting material of the present invention.
The shaping can be conducted according to a known method such as doctor blade method, press molding method, casting method or the like, to obtain a shaped material as a bulk material of rare earth oxide superconducting material. It is also possible to obtain a shaped material by spray- or powder-coating the above-mentioned mixed powder on a substrate made of a metal, a ceramic or the like to form a layer of rare earth oxide superconducting material on the substrate.
The temperature equal to or higher than the incongruent melting point of desired rare earth oxide superconducting material, used in the present invention varies depending upon the kind of the RE component (either of Y, Gd, Dy, Ho, Er or Yb) employed. Said temperature is about 1000°-1200° C. when the RE component is Y, about 1050°-1250° C. when the RE component is Gd, about 1000°-1200° C. when the RE component is Dy, about 1000°-11500° C. when the RE component is Ho, about 950°-11000° C. when the RE component is Er, and about 900°-1100° C. when the RE component is Yb. Said temperature can be appropriately selected within the above range, depending upon the kind of tile RE component used, the heating conditions employed, the size of the shaped material prepared, etc. The heating is conducted by keeping the shaped material in the above temperature range for a given length of time. The time is not particularly restricted and, similarly to the temperature range, can be appropriately selected depending upon the heating conditions employed, etc. The time is 20 minutes to 2 hours generally.
The material after heating is cooled slowly as in the conventional melting process and then subjected to a heat treatment in an oxygen atmosphere at a given temperature to obtain a REBa 2 Cu 3 O y oxide superconducting material. The cooling is conducted at a cooling rate of preferably about 1°-5° C./hr. The heat treatment is preferably conducted in an oxygen atmosphere generally at 650°-400° C. for about 10-50 hours.
EXAMPLES
The present invention is hereinafter described in more detail with reference to Examples. However, the present invention is by no means restricted by the following Examples.
Example 1
Powders of Y 2 O 3 , BaCO 3 and CuO were mixed so that the atomic ratio of Y, Ba and Cu became 1.50: 2.25: 3.25. The mixture was calcined at 800° C. for 10 hours. The calcined product was ground in lsopropyl alcohol in a rotary mill containing zirconia flint pebbles, for 15 hours to obtain a calcined powder having an average particle diameter of about 5 mm.
To the calcined powder was added a platinum (Pt) powder having an average particle diameter of about 3 μm, so that the fired body (oxide superconducting material) has the content of Pt in term of element as shown in Table 1; the mixture was made uniform in lsopropyl alcohol in the same rotary mill using zirconia flint pebbles.
Each of the resulting mixed powders was press-molded to obtain pellets of 7 mm in thickness and 20 mm in diameter.
The pellets were placed in an electric furnace containing the air and kept at 1150° C. for 1.5 hours to give rise to lncongruent melting point. Each of the resulting materials was cooled slowly from 1020° C. to 920° C. in 80 hours, and then heat-treated at 500° C. for 24 hours with the atmosphere in the furnace changed to oxygen to obtain oxide superconducting materials each in pellet form.
The oxide superconducting materials each in pellet form were polished and observed under an optical microscope. FIG. 1 is a microphotograph showing the microstructure of the crystals of the oxide superconducting material of sample No. 1-12, and FIG. 2 is a microphotograph showing the microstructure of tile crystals of the superconducting material of sample No. 1-1 containing no platinum powder. In FIG. 1, the white matrix is an YBa 2 Cu 3 O y superconducting material and the fine black spots dispersed in the matrix is an Y 2 BaCuO 5 non-superconducting material. Meanwhile, in FIG. 2, the black portions which are an Y 2 BaCuO 5 superconducting material have larger particle diameters than in FIG. 1 and are dispersed non-uniformly.
Five pellets were selected at random from each oxide superconducting material, and about 100 mg each was cut out from the pellets and measured for hysteresis of magnetization using a SQUID magnetometer. From the measurement was calculated a Jc (A/cm 2 ) at a magnetic field of 1T at a temperature of 77K. The calculation results of Jc and its ranges expressed in i are shown in Table 1
TABLE 1______________________________________ Content of PtSample No. (Wt. %) Jc (A/cm.sup.2)______________________________________1-1 0.0000 2800 ± 1501-2 0.0025 3300 ± 1701-3 0.0050 3200 ± 1401-4 0.0075 3200 ± 1101-5 0.0100 8700 ± 1801-6 0.0125 11000 ± 2501-7 0.0150 9200 ± 2301-8 0.0175 9800 ± 2301-9 0.02 10000 ± 3101-10 0.05 11000 ± 2001-11 0.10 12000 ± 1901-12 0.50 12000 ± 2301-13 1.00 14000 ± 4201-14 2.00 16000 ± 5001-15 3.00 11000 ± 2601-16 4.50 9900 ± 2701-17 4.75 9500 ± 2401-18 5.00 9000 ± 3201-19 5.25 3400 ± 2001-20 5.50 3300 ± 2101-21 5.75 3400 ± 2201-22 6.00 3100 ± 160______________________________________
Example 2
A calcined powder was obtained in the same manner as in Example 1 except that Gd 2 O 3 was used in place of Y 2 O 3 so that the atomic ratio of Gd, Ba and Cu became 1.3 : 2.0: 3.0.
To the calcined powder was added a rhodium (Rh) powder having an average particle diameter of 15 mm, so that the fired body (oxide superconducting material) has the content of Pt in term of element as shown in Table 2, and mixed powders were prepared in the same manner as in Example 1 and then shaped into pellets of 7 mm in thickness and 20 mm in diameter in the same manner as in Example 1.
The pellets were treated in the same manner as in Example 1 except that they were kept at 1120° C. for 1 hour to give rise to lncongruent melting point and then cooled slowly from 980° C. to 930° C. in 50 hours, whereby oxide superconducting materials in pellet form were obtained.
The microstructure of the crystal of the oxide superconducting material of sample No. 2-12 in pellet form was the same as that of FIG. 1 of Example 1.
In the same manner as in Example 1, five samples each were cut out from the pellets of the oxide superconducting materials and measured for hysteresis of magnetization to calculate the Jc (A/cm 2 ) of each oxide superconducting material at a magnetic field of 1T at a temperature of 77K. The calculation results of Jc and its ranges expressed in ± are shown in Table 2.
TABLE 2______________________________________ Content of RhSample No. (Wt. %) Jc (A/cm.sup.2)______________________________________2-1 0.0000 3600 ± 2602-2 0.0025 3200 ± 2702-3 0.0050 4000 ± 3402-4 0.0075 3000 ± 1502-5 0.0100 9000 ± 3802-6 0.0125 9100 ± 3302-7 0.0150 8900 ± 3102-8 0.0175 12000 ± 3502-9 0.02 11000 ± 3702-10 0.05 10000 ± 2402-11 0.10 10000 ± 2802-12 0.50 11000 ± 3302-13 1.00 10000 ± 4202-14 2.00 13000 ± 3602-15 3.00 8900 ± 3602-16 4.50 12000 ± 2702-17 4.75 9900 ± 4302-18 5.00 13000 ± 2602-19 5.25 2800 ± 3202-20 5.50 3700 ± 2502-21 5.75 2900 ± 3302-22 6.00 3000 ± 360______________________________________
Example 3
BaCO 3 and CuO powders were weighed so that the atomic ratio of Ba and Cu became 1 : 1, mixed and calcined in an oxygen flow at 1000° C. for 10 hours. The calcined product was ground in isopropyl alcohol in a rotary mill containing zirconia flint pebbles, for 10 hours to obtain a barium-copper oxide compound powder having an average particle diameter of about 5 mm.
To the powder were added copper oxide and, as a rare earth element oxide (RE 2 O 3 ), one of Dy 2 O 3 , Ho 2 O 3 , Er 2 O 3 and Yb 2 O 3 so that the atomic ratio of RE: Ba: Cu became 1.8: 2.4 : 3.4. To the resulting powder was added a platinum powder having an average particle diameter of about 1 μm, so that the fired body (oxide superconducting material) has the content of Pt in term of element as shown in Tables 3-6. They were mixed and press-molded to obtain pellets of 10 mm in thickness and 20 mm in diameter. The pellets were placed in an electric furnace containing the air, and kept for 30 minutes under the following temperature conditions which differed depending upon the kind of rare earth element.
1150° C. (Dy 2 O 3 , Ho 2 O 3 )
1100° C. (Er 2 O 3 )
1050° C. (Yb 2 O 3 )
The resulting pellets were cooled slowly for 100 hours in the following temperature range.
1000° C. to 900° C. (Dy 2 O 3 , Ho 2 O 3 )
950° C. to 850° C. (Er 2 O 3 )
900° C. to 800° C. (Yb 2 O 3 )
The pellets were further heat-treated at 500°-300° C. for 50 hours in the same furnace with the atmosphere changed to oxygen, to obtain oxide superconducting materials in pellet form.
In the same manner as in Example 1, 5 samples each were cut out from the pellets of the oxide superconducting materials and measured for hysteresis of magnetization to calculate the Jc (A/cm 2 ) of each oxide superconducting material at a magnetic field of 1T at a temperature of 77K. The calculation results of Jc and its ranges expressed in ±are shown in Tables 3-6.
TABLE 3______________________________________ Rare earth Content of PtSample No. element (Wt. %) Jc (A/cm.sup.2)______________________________________3-1 Dy 0.0000 4000 ± 2203-2 Dy 0.05 4400 ± 1803-3 Dy 0.1 9600 ± 3003-4 Dy 0.5 9500 ± 2603-5 Dy 2 9800 ± 3503-6 Dy 4 9500 ± 3203-7 Dy 5 9000 ± 1103-8 Dy 5.5 6600 ± 2703-9 Dy 6 5300 ± 310______________________________________
TABLE 4______________________________________ Rare earth Content of PtSample No. element (Wt. %) Jc (A/cm.sup.2)______________________________________4-1 Ho 0.0000 3800 ± 2604-2 Ho 0.05 4500 ± 3004-3 Ho 0.1 8900 ± 2404-4 Ho 0.5 9500 ± 3704-5 Ho 2 10000 ± 3104-6 Ho 4 11000 ± 2704-7 Ho 5 9000 ± 2504-8 Ho 5.5 6500 ± 1104-9 Ho 6 4200 ± 370______________________________________
TABLE 5______________________________________ Rare earth Content of PtSample No. element (Wt. %) Jc (A/cm.sup.2)______________________________________5-1 Er 0.0000 4500 ± 3305-2 Er 0.05 4300 ± 2105-3 Er 0.1 8800 ± 3205-4 Er 0.5 9000 ± 3805-5 Er 2 9200 ± 2005-6 Er 4 9300 ± 1905-7 Er 5 8500 ± 3005-8 Er 5.5 6400 ± 2705-9 Er 6 5200 ± 190______________________________________
TABLE 6______________________________________ Rare earth Content of PtSample No. element (Wt. %) Jc (A/cm.sup.2)______________________________________6-1 Yb 0.0000 3300 ± 1506-2 Yb 0.05 4100 ± 2606-3 Yb 0.1 8300 ± 3906-4 Yb 0.5 8800 ± 2306-5 Yb 2 8500 ± 1806-6 Yb 4 9000 ± 4106-7 Yb 5 8900 ± 370______________________________________
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A rare earth oxide superconducting material represented by REBa 2 2Cu 3 O y (RE is Y, Gd, Dy, Ito, Er or Yb), comprises oxide grains and at least one element selected from Rh and Pt, uniformly dispersed in the grain in a proportion of 0.01-5% by weight (in terms of element) based on the rare earth oxide superconducting material. The rare earth oxide superconducting material can be produced by a melt processing and gives a high critical current density even in a highly magnetic field.
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FIELD OF THE INVENTION
This invention relates to a closed loop combustible waste reduction process and apparatus which can utilize any type of combustion means for disposing of hazardous, as well as non-hazardous, burnable waste. Such wastes include toxic combustible liquids, oil slurries, soils contaminated with dioxin, PCBs, creosote, or any other potentially harmful or toxic combustible material. In particular, the present invention relates to a combustible waste reduction process and apparatus in which the operating pressure ranges from about 8.3 psia to about 15.0 psia and which employs no venting or stack discharge of pollutants whatsoever. In this process, the flue gas stream is scrubbed, enriched with oxygen and recycled to the combustion chamber.
BACKGROUND OF THE INVENTION
The disposal of hazardous waste is increasingly becoming a serious problem to industry as governmental regulations become more stringent. The disposal of hazardous waste is primarily accomplished through landfills and incineration. While the industry has historically preferred landfills over incineration, primarily because of cost, incineration has become a more competitive alternative due to the increased costs associated with the ever-expanding governmental regulations governing landfills. For example, a series of land disposal prohibitions covering specified classes of hazardous wastes took effect between 1986 and 1989. As the industry looks toward incineration as a primary means of disposing of hazardous waste, however, the growth of more stringent governmental restrictions continues to undermine the cost-effectiveness of incineration processes. For example, the destruction and removal efficiency (DRE) ratings for incineration are presently set at 99.99% for most hazardous waste, and 99.9999% for polychlorinated biphenyls (PCBs).
The incineration of hazardous waste is fraught with problems due to the fact that the waste must be rapidly disposed of before harm is done to the environment, but additionally, the destruction of any potentially toxic chemicals must be sufficiently complete so that the gases which evolve therefrom are non-hazardous. To completely decompose such chemicals, relatively highly efficient and high temperature combustion is required. Such high efficient and high temperature combustion is typically expensive to generate and maintain.
In addition, the discharge stack emissions from incineration are typically an important concern for several reasons. One reason is that the public views stack emission plumes with suspicion, and sometimes justifiable fears, that the incinerator operator is discharging hazardous, or toxic, gases into the atmosphere. Another reason is that federal and state authorities have implemented regulations governing stack emissions with regular monitoring, testing, and validation to insure that prescribed emission limits are not being exceeded.
There is a substantial need in the art, therefore, for improved combustible waste reduction processes and apparatus which are able to meet the present destruction and removal efficiency requirements, as well as requirements in the foreseen future.
It would be desirable to have a closed-loop combustible waste reduction process and apparatus in which no airborne emissions are released into the atmosphere and in which the solid byproducts from the process can be collected, tested, treated, and disposed of safely.
It would also be desirable to have a closed-loop combustible waste reduction process and apparatus capable of operating below atmospheric pressure to provide a faster burn rate which reduces combustible wastes more efficiently than traditional incinerator units.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an improved process and apparatus for combusting waste materials so that no gases or other byproducts of combustion are released into the atmosphere. The process comprises the steps of:
(a) loading combustible waste into an air-tight combustion chamber where the waste is combusted at a temperature from about 1800° F. to about 2000° F.;
(b) passing the resulting flue gas stream from the combustion chamber to a heat reduction chamber where the temperature of the flue gas stream is reduced to about 1100° F.;
(c) passing the flue gas stream from the heat reduction chamber to a heat exchanger where the temperature of the flue gas stream is further reduced;
(d) passing the flue gas stream from the heat exchanger through a particulate trap to remove particulates from the flue gas stream;
(e) passing the flue gas stream from the particulate trap to a gas cleaning chamber where acids within the flue gas stream are neutralized and additional particulates are removed;
(f) enriching the flue gas stream from the cleaning chamber with oxygen; and
(g) injecting the oxygen enriched flue gas stream into the combustion chamber in varying amounts in response to pressure and temperature measurements taken in the combustion chamber to maintain the pressure and temperature in the combustion chamber within pre-selected ranges until the combustion of the waste is completed.
The apparatus of the present invention used for the ventless combustion of waste material comprises an air-tight combustion chamber; a heat reduction chamber in air-flow communication with the combustion chamber; a heat exchanger in air-flow communication with the heat reduction chamber; a first fan for drawing flue gases through the apparatus disposed between the heat exchanger and a gas cleaning chamber; a second fan for drawing the flue gases from the gas cleaning chamber through a conduit back into the combustion chamber; an oxygen supply for enriching the flue gases in the conduit with oxygen to produce an oxygen enriched flue gas stream; a motorized gas supply valve disposed in the conduit; and control means for maintaining the pressure and temperature in the combustion chamber within pre-selected ranges set in the control means by varying the flow of the oxygen enriched flue gas stream through the gas supply valve into the combustion chamber in response to pressure and temperature measurements from the combustion chamber monitored by the control means.
Without a vent or stack, the system of the present invention is not an incinerator and should not be classified and regulated as such. Classification as an incinerator indicates a unit has a stack and vents emissions, in varying amounts, into the atmosphere. Emissions vented by an incinerator include the following: Polychlorinated--CDD/CDF; Carbon Monoxide--CO; Particulate Matter--PM; Hydrogen Chloride--HCl; and Sulfur Dioxide --SO2.
The stackless, combustible waste reduction process of the present invention removes the solid materials from the emission gases which are continually recycled back into the combustion chamber. Through the entire combustible waste reduction process of the present invention, no airborne emissions are vented into the atmosphere. Moreover, by running the gases through a heat reduction chamber and a heat exchanger to cool the gases prior to re-entering the combustion chamber, a faster and more efficient combustion of waste is obtained than can be obtained in traditional incinerator units. For example, the ventless process and apparatus of the present invention reduces combustible waste 93% to 96%. Furthermore, as oxygen is used and replenished, by injecting oxygen back into the combustion chamber of the closed loop system, the combustion fire will operate in a slight vacuum, i.e., at slightly below atmospheric pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, preferred embodiments of the invention and preferred methods of practicing the invention are illustrated in which:
FIG. 1 is a simplified flow diagram of a preferred embodiment of the ventless, combustible waste reduction process and apparatus of the present invention.
FIG. 2 is a cross-sectional view of an automated combustion chamber employed in a preferred embodiment of the ventless, combustible waste reduction process and apparatus of the present invention.
FIG. 3 is a cross-sectional view of a batch-type combustion chamber employed in a preferred embodiment of the ventless, combustible waste reduction process and apparatus of the present invention.
FIG. 4 is a cross-sectional view of an upper heat reduction chamber, a heat exchanger and a particulate trap employed in a preferred embodiment of the ventless, combustible waste reduction process and apparatus of the present invention.
FIG. 4A is a cross-sectional view of the lower section of the heat reduction chamber taken along Line 4--4 of FIG. 4.
FIG. 5 is an expanded cross-sectional view of a gas cleaning chamber employed in a preferred embodiment of the ventless, combustible waste reduction process and apparatus of the present invention.
FIG. 6 is an expanded cross-sectional view of the junction between the oxygen supply line and the lines which recycle the cleaned and oxygen enriched flue gases back into the combustion chamber employed in a preferred embodiment of the ventless, combustible waste reduction process and apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described with respect to the preferred physical embodiments constructed in accordance herewith. It will be apparent to those of ordinary skill in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not limited by the specific embodiments illustrated and described, but only by the scope of the appended claims, including all equivalents thereof.
The combustible waste reduction process and apparatus of the present invention can be best understood by reference to FIG. 1 which shows a preferred layout of the apparatus used to perform the combustible waste reduction process of the present invention. As described more fully below, the waste may be fed into the system in batches manually or automatically at pre-selected intervals depending, in part, on the amount of waste needed to be combusted.
In a preferred embodiment of the invention in which waste is fed automatically, the combustion chamber is preferably constructed as shown in FIG. 2. As shown therein, combustible waste is fed from a hopper (not shown) into the combustion chamber 2 via hopper door 1 which is activated by hydraulic cylinder 66. After falling from the hopper, the waste enters the first waste holding chamber 30 and the hopper door 1 is closed by the hydraulic cylinder 66. The loading door 1A is then opened by spaced hydraulic cylinders 64 and the first hydraulic transfer ram 34 is activated to transfer the waste into the second waste holding chamber 31. As shown schematically in FIG. 2, the transfer ram 34 is mounted on a side of the combustion chamber 2. After the transfer ram 34 has been retracted and the door 1A closed, door 1B is opened and hydraulic transfer ram 38, which is mounted on door 1A, is activated to transfer the waste into the combustion loading chamber 40. Transfer ram 38 is then retracted and door 1B is closed. Hydraulic cylinders 67 are used to moved door 1B up and down between its closed and open positions. At this point, the hydraulic fire door 1C is opened to provide access to the first combustion zone 70 of combustion chamber 2. The fire door 1C is articulated by hydraulic cylinders 68 and is preferably lined with refractory material on the side facing the first combustion zone 70. After the fire door 1C has been opened, the hydraulic transfer ram 42, which is mounted on door 1B, is activated to transfer the waste into the first combustion zone 70. Door 1C is then closed and combustion of the waste may be initiated if not already in progress. Using the above-described series of waste holding chambers and transfer rams, the waste material can be automatically loaded into the combustion zones 70 and 71 without venting any flue gases into the atmosphere.
Each of the doors 1A, 1B and 1C are gate-type doors that articulate within opposing guide frames mounted to the sides of the combustion chamber 2. Small hydraulic cylinders (not shown) are mounted in the frame members on both sides of each door. The cylinders on one side of the door operate to immobilize the door within the frame members by forcing the door against the opposing cylinders and vice versa.
The flue gas stream from the combustion chamber 2 is piped to an upper, heat reduction chamber 4 via transfer duct 3. The upper chamber 4 is also lined with insulation and refractory material, rated up to 2,400° F., to match the combustion chamber 2. The chamber 4 functions as a cool down chamber for the gases prior to entering the heat exchanger/boiler 6 via transfer duct 5. In the heat reduction chamber 4, the temperature of the flue gas stream is reduced from about 1800° F. to about 1100° F. Unlike a conventional incinerator's upper chamber that is a second stage combustion chamber, the upper chamber 4 is a cool down chamber. The process of the present invention does not require a second stage combustion chamber. As shown in FIG. 4, the upper, heat reduction chamber 4 is divided by horizontal wall 43 into upper and lower sections 44 and 45, respectively. As shown in FIG. 4A, deflectors 46 are staggered within the lower section 45 which trap a significant portion of the particles or fly ash carried by the flue gases passing therethrough. The particulates trapped by the deflectors 46 in the lower section 45 are periodically removed via domed doors 49.
If energy recovery is to be utilized, the heat exchanger/boiler 6 drops the temperature of the gases to 350° F. as they pass through. Over a period of time, the exhaust temperature of the heat exchanger 6 will continue to increase. Upon the exhaust temperature reaching 500° F., the heat exchanger 6 will then need to be cleaned.
An induction fan 10 pulls gases from the upper, heat reduction chamber 4 and the heat exchanger 6 through the transfer duct 7 into the particulate trap 8, which filters out additional large particulate matter. The flue gas stream is then passed through transfer duct 9, through the induction fan 10 and transfer duct 11 into the gas cleaning chamber 50 comprising a lime bath 12, a gas wash 13 and a charcoal chamber 19. As shown in FIGS. 1 and 5, the gas cleaning chamber 50 preferably comprises one vessel having three separate cleaning stages 12, 13 and 19. In operation, the induction fan 10 blows gases into the lime bath 12. The outlet 11A of transfer duct 11 is positioned so that the gases are released at a depth at least 30% below the upper surface of lime bath 12 which is covered by a perforated steel plate or screen 52. The gases pass through the lime bath 12, where certain acids are neutralized, into the second stage gas wash 13 where the gases pass through the lime water spray 48 emanating from nozzle 47. The lime water spray 48 acts to trap smaller particulate matter which has passed through the lower section 45 of the heat reduction chamber 4 and the particulate trap 8. The lime bath 12 and gas wash 13 with lime water spray 48 are replenished from the lime/water mixing tank 14. As shown in FIGS. 1 and 5, the mixing tank 14 includes a high pressure pump 15 and a supply pipe 16 for pumping the lime/water mixture into the gas wash 13 as the lime water spray 48. Lime is introduced into the mixing tank 14 via lime injection port 18. Return pipe 17 provides for the return of the lime water including solid materials from the lime bath 12 to the mixing tank 14 which incorporates a lower sludge basin 54 where some of the fly ash and other solid materials are separated from the lime water and removed from the system.
In the charcoal chamber 19, which comprises the third stage of the gas cleaning chamber 50, the gases pass through a filter 51 which comprises loosely packed activated charcoal supported on the perforated steel plate or screen 53. The charcoal filter 51 removes some of the metals from the flue gases to complete the cleaning process thereof.
After the gases exit the filter 51, they are drawn through duct 20 by the induction fan 21 into separate lines 22 and 24 which communicate with the first and second combustion zones 70 and 71, respectively. In lines 22 and 24, oxygen is mixed, at a 20% to 30% ratio, with the gases to raise the system pressure to five (5) psi over atmospheric pressure. Oxygen supply 60 comprises an oxygen generator 26, oxygen storage tank 27 and oxygen vaporizer 28 to supply oxygen via oxygen supply duct 29 to both the lines 22 and 24 via line 29A and to the combustion chamber 2 via line 29B. The oxygen enriched flue gas stream is then forced by the injection fan 21 into the combustion chamber 2 through injection supply lines 22 and 24 having injection ports 23 and 25, respectively, located on the ash rams 92 and 93 within the combustion chamber 2.
FIG. 6 illustrates in greater detail the juncture of oxygen supply line 29A with lines 22 and 24. As shown therein, the supply line 29A splits into a tee 80 for engagement with the respective lines 22 and 24. A pressure regulator 81 is located on the oxygen supply line 29A for regulating pressure in line 29A from about 2000 psi to about 14.7 psi or atmospheric pressure on the combustion chamber side of the regulator 81. Motorized mixing valves 82 are disposed in lines 22 and 24 at the points where those lines intersect with the tee 80 of the oxygen supply line 29A. The motorized mixing valves 82 are controlled by the controllers 83 which incorporate sensors 84 that measure the pressure differential delta P 1 across the mixing valves 82, i.e., between the oxygen supply line 29A which is regulated at about 14.7 psi and the lines 22 and 24. As the pressure differential delta P 1 increases or as the pressure in lines 22 and 24 drops below atmospheric due to the burning of the oxygen in the combustion chamber 2, the controllers 83 allow the motorized mixing valves 82 to open to allow oxygen to be mixed with the cleaned flue gases and the mixture is fed into the combustion chamber 2 via the injection ports 23 and 25.
The flow of the oxygen enriched flue gases into the combustion chamber 2 is further controlled by pressure regulated valves 65 located in lines 22 and 24 near the injection ports 23 and 25. The pressure regulator valves 65 are motorized and are connected to the controller of the system which activates the valves 65 in response to temperature and pressure measurements monitored by the controller. The process controller may comprise any suitable microprocessor or a basic programmable logic controller. Preferably, the valves 65 are Honeywell BG1600 gas supply valves which are knife-type valves, the openings of which can be varied between minimum and maximum settings.
As shown in FIG. 2, a thermocouple well 85 is disposed within the combustion chamber 2 for holding a thermocouple (not shown) for monitoring the temperature inside the combustion chamber 2. Other temperature control relays and pressure control relays may also be employed for monitoring the temperature and pressure throughout various parts of the system. In operation, the initial batch of waste is loaded and transferred to the first combustion zone 70 within the combustion chamber 2 as described above with reference to FIG. 2. The waste is then ignited by the ignitor 88 which ignites the mixture of oxygen gas and a flammable gas such as propane from lines 29B and 87, respectively. As shown in FIG. 2, lines 29B and 87 intersect near the ignitor 88 within the combustion chamber 2. After the waste has been ignited, the flow of oxygen from line 29B and flammable gas from line 87 is shut off. The flammable gas supply (not shown) preferably comprises a tank of liquified gas such as propane. In burning the waste, the controller maintains the temperature within the combustion chamber 2 at a predetermined value, preferably 1800° F. As the waste is burned, oxygen is consumed creating a negative pressure or slight vacuum within the combustion chamber 2. In order to keep the temperature in the combustion chamber 2 at the desired setting, the controller allows valves 65 to open to allow the oxygen enriched flue gases to enter the combustion chamber 2. If the temperature in the combustion chamber 2 starts to rise above the temperature setting in the controller, the controller either closes the valves 65 completely or reduces the openings therein to eliminate or reduce the flow of oxygen enriched gases into the combustion chamber 2. Likewise, if the pressure in the combustion chamber 2, which is air-tight, is below 14.7 psia and the temperature therein is at or below the preset value in the controller, the controller will open the valves 65 sufficiently to raise the temperature in the combustion chamber 2 to the preset value or to maintain the temperature at the preset value. The controller will close the valves 65 to shut off the flow of oxygen enriched flue gases to the combustion chamber 2 if the pressure therein drops to 8.3 psia or below to keep from creating too great a vacuum in the combustion chamber 2.
When the batch of waste is nearly consumed, the fire in the combustion chamber 2 will start to burn less vigorously as the waste fuel is depleted. At a certain point during such a "burn down," the pressure in the combustion chamber 2 is likely to reach 14.7 psia since less oxygen is being consumed than the amount entering the combustion chamber 2. When the pressure reaches 14.7 psia in the combustion chamber 2, the controller will close the valves 65 until the pressure drops below 14.7 psia, even though the temperature is below the preset value in the controller. Here, the response of the controller to the pressure measurement within the combustion chamber 2 takes precedence over the temperature measurement therefrom. Since at this point no oxygen enriched gas is entering the combustion chamber 2, the pressure therein will eventually drop back below 14.7 psia as long as the fire in the combustion chamber 2 continues to burn. When the pressure drops below 14.7 psia again in the combustion chamber 2, the controller will open the valves 65 until the pressure therein reaches 14.7 psia and then the valves 65 will again be closed. The system automatically modulates in this manner during the "burn down" until all the waste is combusted.
In the modular combustion chamber 2 shown in FIG. 2, once the waste and combustion zone 70 has burned sufficiently or after a predetermined period has elapsed (usually based on the characteristics of the waste being burned) another batch of waste which has been loaded and transferred into the combustion loading chamber 40 will be transferred by the combustion loading chamber hydraulic ram 42 into the combustion zone 70 as described above. As the ram 42 pushes the new batch of waste into the combustion zone 70, the waste then being combusted therein is pushed from the platform 70A down onto platform 71A. Each of the platforms 70A and 71A preferably is made from refractory bricks laid on top of the sheet metal housing 91 for the hydraulic combustion chamber rams 92 and 93. The bottom faces of the housings 91 are sealed with elastomeric gaskets (not shown) before being bolted onto the housings 91 to maintain the air-tightness of the combustion chamber 2. As each successive batch of waste is transferred into the combustion chamber 2, the combusted waste is transferred by the hydraulic rams 42, 92 and 93 towards the wet ash tank 95 having a water level indicated by 95A. The hydraulic rams 92 and 93 have guide rods 94 attached to the faces of the rams which prevent the ram faces from being twisted by the waste. The guide rods 94 run in and out of cylindrical conduits 96 disposed within the housings 91. In addition, compression seals are mounted between the cylinder and the face of the rams 92 and 93 to further seal the combustion chamber 2. A conventional type combustion chamber ram does not have a compression seal for the bore of the cylinder to run through. The combusted ashes ultimately are transferred into the wet ash tank 95 via conduit 97 where the ashes can be removed from the system without interrupting the operation thereof.
If the combustion chamber is of the batch-type, the system will shut down after all the waste fuel has been combusted. FIG. 3 illustrates a batch-type combustion chamber 75 which may also be used in accordance with the process of the present invention. The induction fans in the system remain in operation for up to eight hours after the "burn down" has been completed to clean the flue gases remaining in the system. A by-pass conduit may be used during this time to route the flue gases around the combustion chamber so that the gases do not pick up any of the fly ash in the combustion chamber. After the combustion chamber 75 cools down, the ashes may be removed through the dome door 89 which provides access to the interior of the combustion chamber for ash removal or for servicing the refractory therein. The dome door 89 is sealed with an high-temperature elastomeric gasket such as a rope gasket similar in type to those used on boiler doors. After the batch-type chamber 75 is cleaned, it may be then loaded again with waste through loading door 86. Once the waste is loaded, door locks 90 are employed to keep the loading door 86 secure and the combustion chamber 75 air-tight. The waste is then ignited and combusted as described above.
The stackless, combustible waste reduction process of the present invention operates continuously in the manner described above. The size of the combustion chambers 2 or 75, as with the entire system, is determined by the amount of waste to be reduced in an eight (8) to twenty four (24) hour period of time. The combustion chambers 2 and 75 are fabricated metal shells with a high temperature insulation applied to the inside of the shell. The insulation is covered by a high temperature refractory liner rated for temperatures up to 2,400° F. The operation temperature of the combustion chamber 2 is preferably from about 1,800° F. to about 2,000° F. As described above, the transfer rams are used to move the waste through the waste holding chambers of the combustion chamber 2 as the process of the present invention is carried out. If liquid waste is to be reduced, then the hydraulic transfer rams are not required.
Flow rates, fan sizes, and chamber sizes are also determined by the amount of combustible waste or liquid waste to be reduced over a specified period of time. The process of the present invention is capable of handling combustible waste in an operating range from one hundred (100) pounds to in excess of one thousand (1,000) tons in a twenty four (24) hour period of time, functioning within the preferred pressure ranges set forth above.
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those of ordinary skill in the art without departing from the spirit and scope of the invention as defined by the following claims, including all equivalents thereof.
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A ventless, combustible waste reduction process and apparatus which can utilize any type of combustion means for disposing of hazardous, as well as non-hazardous, burnable waste. Such wastes include toxic combustible liquids, oil slurries, soils contaminated with dioxin, PCBs, creosote, or any other potentially harmful or toxic combustible material. In particular, the present invention relates to a ventless, combustible waste reduction process in which the operating pressure is slightly below atmospheric pressure and which employs no venting or stack discharge of pollutants whatsoever. The entire flue gas stream is scrubbed, enriched with oxygen and recycled to the combustion chamber in varying amounts in response to pressure and temperature measurements taken in the combustion chamber to maintain the pressure and temperature in the combustion chamber within pre-selected ranges.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the field of environmental control systems and, in particular, to a process for determining the refrigerant charge level in a sophisticated aircraft environmental control system.
[0003] 2. Description of Related Art
[0004] Modern, lightweight vapor cycle systems sometimes have a shortcoming, which is that it is difficult to detect refrigerant over- and under-charges. Previous systems incorporated receivers and sight glasses, making charge detection possible although not reliable. An efficient, modern system may employ separately controlled compressor speed, evaporator expansion valve, surge control valve, flash sub-cooler expansion valve, and condenser flow control shutters. These many “moving parts” make charge detection by traditional methods (i.e. compressor inlet superheat or condenser outlet sub-cooling measurements) unsuitable. Mechanical charge level indication systems (sight glasses, liquid level indicator, float switch and receiver tank) all rely on measuring the proportion of a liquid versus saturated vapor in a container. This container is located at a position downstream of the condenser heat exchanger that will contain saturated refrigerant (liquid and vapor).
[0005] By design, sub-cooled refrigerant (no vapor content) exits the condenser heat exchanger of this vapor cycle system. A tank located at this spot would be full of liquid refrigerant, thus there would be no level to measure. In order to create a location in this system where saturated refrigerant, consisting of a mixture of vapor and liquid, would be present, the condenser heat exchanger would have to be replaced with a separate condenser and sub-cooler. A receiver could then be located between them.
[0006] The liquid level in the receiver could then be measured by mechanical means i.e. a sight gage/level switch. For a given charge level, the level in the receiver would vary, depending on ambient conditions and system load. The weight and volume penalty associated with such a design would be undesirable in most cases.
[0007] U.S. Pat. No. 5,253,482 Heat Pump Control System by E. Murway describes a scheme in which the receiver is mounted on a weight transducer, allowing the charge level to be monitored. U.S. Pat. No. 4,601,177 Refrigerant Over-Charging System Of Closed Circuit Refrigeration Air Cooling System By M. Taino, et al. describes a valve for charging a refrigeration system, which relies on sensing the liquid level in a receiver to close the valve when the desired liquid level is reached. This scheme prevents overcharging but does not detect undercharges.
[0008] Modern vapor cycle systems may incorporate a number of sensors and a microprocessor, which reads a number of system parameters, making some computation-based approaches possible. One such approach is described in U.S. Pat. No. 5,152,152. Method Of Determining Refrigerant Levels by L. R. Brickner, et al. Here, refrigerant charge level is determined by operating the system in a special mode, then comparing the time response of evaporator temperature to “model” responses, collected in controlled conditions with known charge levels.
[0009] Yet another system is disclosed in U.S. Pat. No. 5,860,286 System Monitoring Refrigeration Charge by S. Tulpule incorporates a neural network-based approach; this particular invention takes a two-step approach using four layers. The first step is a “Kohonen” type self-organizing network (although not stated as such) consisting of an input layer and a two dimensional “hidden layer” of 4×16 neurons. Individual training patterns are learned in a cluster of neurons surrounding a central neuron. The training methodology is sometimes referred to as “competitive learning” because node weight updating is based on a competition of equally spaced center neurons to see which is initially closest to the input training pattern. There is no activation function on any of these neurons. During operation an unknown input is applied to the net, which finds the three closest stored patterns, which are further processed in the “interpolation” layer, which consists of 16 neurons using a hyperbolic tangent activation. The final single output neuron also uses a hyperbolic tangent activation function.
[0010] Applicant's co-pending patent application Ser. No. ______ Process For Determining The Refrigerant Charge Level Using A Neural Net, filed _/, 2004, disclosed a process for determining the charge level of a vapor cycle environmental control system, having a condenser, evaporator, and an expansion valve. In detail, the invention includes the steps of providing a neural network having four input neurons, two hidden neurons and three output neurons; determining the number of degrees below the saturation temperature of the liquid refrigerant exiting the condenser and providing this measurement to the first input neuron; sensing the condenser sink temperature and providing the measurement to the second input neuron; sensing either the refrigerant outlet temperature from the condenser or the evaporator exhaust air temperature and providing the measurement to the third input neuron, sensing the evaporator inlet temperature and providing the measurement to the fourth input neuron; and using the trained neural network to monitor the charge level in the system. However, this invention could only indicate whether there was an over or under or normal charge. It could not indicate the amount of over or under charge.
[0011] Thus, it is a primary object of the invention to provide a process for monitoring the charge level of a vapor cycle environmental control system.
[0012] It is another primary object of the invention to provide a process for monitoring the charge level of a vapor cycle environmental control system using a back propagation neural net.
[0013] It is a further object of the invention to provide a process for monitoring the charge level of a vapor cycle environmental control system using a neural net having a minimum of input neurons.
[0014] It is a still further object of the invention to provide a process for monitoring the charge level of a vapor cycle environmental control system using a neural net having only one output neuron.
SUMMARY OF THE INVENTION
[0015] The invention is a process for determining the charge level of a vapor cycle environmental control system, having a condenser and evaporator. In detail, the process includes the steps of;
1. Providing a neural network having four input neurons, two hidden neurons and three output neurons; 2. Determining the number of degrees below the saturation temperature of the liquid refrigerant exiting the condenser and providing this measurement to the first input neuron; 3. Sensing the condenser sink temperature and providing the measurement to the second input neuron; 4. Sensing the refrigerant outlet temperature from the condenser and providing the measurement to the third input neuron, 5. Sensing the evaporator return air inlet temperature and providing the measurement to the fourth input neuron; training the neural net by providing under, over and Known refrigerant charge levels to the system and operating the system under varying operating conditions; such that weighting factors for the neural net and post-processing approach are determined; and 6. Using the trained neural network to monitor the charge level in the system.
[0022] Prior to processing by the neural net, the inputs are linearly scaled to the range 0.1-0.9, which improves training convergence. The hidden layer of 2 neurons, each having a logsig activation function and the output layer of just one neuron have a “purelin” activation function. There is no need for any additional layer to perform interpolation with this approach. The preferred training approach is a Levenberg-Marquardt training paradigm.
[0023] The value in each input neuron is multiplied by the “weight” of the connection between that input neuron and a hidden neuron and summed with similar weighted values from the other input neurons. A bias value associated with each hidden neuron is then added. The “logsig” function is then applied to the result for each hidden neuron. Similarly, the outputs of the hidden neurons are multiplied by the respective weights between the hidden and output neurons, summed and biases added. The “purlin” function is applied to the result to produce the output activation levels. Once the neural net has been “trained” it can be used to monitor charge level.
[0024] The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which the presently preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a simplified schematic of a vapor cycle environmental control system (air conditioning system).
[0026] FIG. 2 is a diagram of the neural net used to determine charge level.
[0027] FIG. 3 is a graph illustrating the logsig activation function for hidden layer and output layer neurons.
[0028] FIG. 4 is a graph illustrating the purelin activation function for the output neuron.
[0029] FIG. 5 is a flowchart for process of training the neural net.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] The vapor cycle system, illustrated in FIG. 1 , is a modern, compact system design. Such systems are typically installed in an aircraft and are used for forced air cooling of avionic equipment. During conditions requiring maximum cooling, the refrigerant enters the evaporator 12 as a low temperature mixture of liquid and vapor. In this low pressure side of the refrigeration loop, the pressure remains essentially constant as the refrigerant flows through the evaporator. In the evaporator 12 , the liquid portion of the refrigerant evaporates, absorbing heat from the air from the avionics compartment (not shown) pulled there through by the evaporator fan 14 . The refrigerant exits the evaporator 12 in line 15 as a superheated vapor and flows to the compressor 16 driven by motor 17 . The low pressure vapor enters the first stage 18 of the compressor 16 , where it is compressed to a pressure midway between the first stage inlet pressure and second stage 20 discharge pressure.
[0031] The hot vapor from compressor second stage 20 , now at its highest pressure, flows through line 22 . A by pass line 24 having a control valve 26 connects the output line 22 to the line 15 . The valve 26 is opened to bypass pressurized refrigerant to the inlet of the compressor to prevent compressor surge. The pressurized refrigerant in line 22 then travels to the condenser 30 where the refrigerant is fully condensed and sub-cooled, rejecting heat to the air drawn through by the condenser fan 32 . Note that in flight, the fan 32 is disabled, since ram air will flow through the condenser 30 . Notice that, since the refrigerant exits the condenser 30 as a sub-cooled liquid, there is no appropriate location for a receiver in this architecture. The lack of a receiver is one of the main reasons why some of the traditional charge-measuring schemes are not applicable to this system. The liquid refrigerant then exits the condenser 30 , via line 33 , and flows back toward the evaporator 12 .
[0032] The refrigerant enters a flash sub-cooler 34 and exits in line 35 . The high-pressure liquid refrigerant is further sub-cooled by expanding a small portion of the total flow and allowing it to flow through the cold side passages of the sub-cooler via line 36 . A valve 38 in line 36 controls this bypass flow. The expanded bypass flow absorbs heat and becomes a superheated gas. The low pressure vapor exiting the cold side of the sub-cooler 34 mixes with the compressor 16 first stage 18 discharge flow before entering the second stage 20 of the compressor 16 . Meanwhile, the sub-cooled liquid that rejected heat in the flash sub-cooler becomes further sub-cooled. Note that under moderate outside temperatures, the valve 38 is closed, and no refrigerant is diverted for flashing, and no further sub-cooling is accomplished in the sub-cooler 34 . The refrigerant continues to flow in line 35 to the expansion valve 42 , where it expands into a two-phase mixture, down to the low-pressure side of the refrigeration loop. This mixed-phase flow then enters the evaporator 12 , and the cycle repeats. This is a typical system and there are numerous variants, but all work on the same general principle.
[0033] The following sensors are used to monitor the system.
1. Sensor 46 monitors condenser refrigerant outlet temperature (T CDO ). 2. Sensor 48 monitors evaporator exhaust air temperature (T EFO ). 3. Sensor 54 monitors refrigerant pressure at the outlet of the compressor (P CPO ). 4. Sensor 56 monitors incoming hot air temperature from the avionics (T EVI ). 5. Sensor 58 monitors incoming cooling air temperature to the condenser (T CDRI ).
All the sensor outputs as well as all the valves and motor, etc. are fed to a system controller 60 , which automatically runs the system 10 . Another critical parameter is the condenser outlet sub-cooling. This parameter is calculated by the controller 60 , which uses the T CDO and P CPO and refrigerant property tables.
[0039] FIG. 2 is a schematic of the artificial neural net (ANN). The input layer 62 has four neurons, 62 A, 62 B, 62 C and 62 D. The hidden layer 64 has two neurons 64 A and 64 B, while the output layer 66 has one neuron 66 A, for indicating charge level in pounds. In order to determine the weights and biases associated with the ANN, it is necessary to create an appropriate training set. The training of ANN's is old in the art and need not be discussed in great detail. The training set was developed with the goal of duplicating and spanning the likely range of parameter boundary conditions in which the deployed ANN is expected to function. This will determine the ANN:
Input weights W IH11 , W IH12 , W IH21 , W IH22 , W IH31 , W IH32 , and W IH41 Output weights W HO11 , W HO12 , W HO13 W HO21 , W HO22 , and W HO23 Hidden layer biases B H1 , and B H2 Output layer biases B 01
[0044] The system is run through a matrix of load temperatures, sink temperatures, and an appropriate range of charge levels. In our case, we ran charge levels ranging from about 4 pounds below the bottom of the acceptable charge range up to 2 pounds above the top of the acceptable range, in 1 to 2 pound increments. Note that, in this vapor cycle system, the system controller will detect other, secondary faults will occur with extreme high & low charges (i.e. charges outside of our test range); so detection outside of our test range was not necessary or practical. The range of temperatures chosen for the evaporator and condenser air loops were limited to the range of temperatures that will be experienced when the aircraft systems are operated on the ground for maintenance, and further limited by a low temperature limit—our particular system enters a “cold start” state, in which only the evaporator fan and heater operate (i.e. the compressor doesn't start) until the load temperature reaches a prescribed threshold. We used 10 to 30 degree F. increments of temperature for both the load and sink loops.
[0045] The resulting data set will contain a number of transients, which may not be useful for training a successful ANN. In our case, the periods during which the 2 pound increments of charge were being added were eliminated, in addition to several minutes after each charge addition. The load and sink temperature increments also represent transients; therefore, we eliminated the data during these transitions, plus several minutes after each transition. The resulting data set was used for training, validating and test the ANN.
[0046] FIG. 3 presents a graph illustrating the logsig activation function for the hidden layer and output layer neurons. FIG. 4 represents a graph of the purelin type activation function used for the output layer neuron. Of course, other activation functions can be used.
[0047] The flow chart for the training process for the ANN is presented in FIG. 4 .
Step 70 Divide Test Data—The collected data (discussed previously) is divided into three separate sets for training, checking and testing. Approximately 20% of the data is used to build the training and checking sets and the remainder is used for blind testing of the trained net. The data used in the training and checking data sets is randomly sampled from all the data to insure that it is statistically representative of the overall population. The maximum and minimum value templates for each input parameter are included in the training set which guarantees that all the remaining checking and testing inputs will at worst be equal to the minimum and maximums of the training set. This implies the ANN will be interpolating answers as opposed to extrapolating answers outside its training data bounds. The training set input parameters are linearly scaled to the range (0.1-0.9) prior to training as opposed to the range (0-1). It has been shown in prior art that this scaling range leads to improved training convergence. The scaling factors derived from the training set are used to scale the checking and testing data sets. Step 72 Apply Training And Checking Data Sets—The training and checking data sets are applied to a neural net training paradigm, which repeatedly cycles through the training set. At each cycle (epoch) the set of neural net weights and biases is adjusted, according to the particular paradigm training law being used, to minimize the error between the actual and ANN estimated training set output. At each epoch, the checking set is applied to the current ANN and the error between the actual and ANN estimated checking output is computed. On average the training error decreases with each epoch; however at some point the checking error ceases to improve or begins to increase. Step 74 Determine Acceptable Checking Set Error—At this point, the training is halted to avoid over-training the ANN, which would cause poor generalization on untrained data. Many training paradigm algorithms have been developed which can compute the best ANN weights and bias for a given training set. Training algorithms like Conjugate Gradient and Quasi-Newton are just two examples. The Levenberg-Marquardt training algorithm was chosen for this effort because of its speed of convergence at the expense of more memory used, which was not an issue. If No back to Step 72 , if Yes then to Step 76 . Step 76 Apply Testing Data To Neural Net—The blind testing set is applied to the trained ANN. Step 78 Acceptable Test Set Error—If the resulting error is acceptable (Yes) then to Step 80 , If not acceptable (No) then to Step 81 Step 80 Save Final Weights And Biases Step 81 Re-train-Return to Step 72
[0055] During vapor cycle system operation, the system controller feeds the ANN all of the required parameters (sensed or calculated) at an appropriate sample rate (approximately 2 seconds apart, in our case). The ANN produces a “raw” charge state estimate for each of these snapshots. A first order low-pass filter (indicated in dotted lines and numeral 74 in FIG. 2 ) is then used to average and smooth output transients. The result is reported to the operator.
[0056] Thus it can be seen, that a simple trained neural net can be used to indicate charge levels (output from neuron 66 A) of refrigerant in a vapor cycle environmental control system.
[0057] While the invention has been described with reference to a particular embodiment, it should be understood that the embodiment is merely illustrative as there are numerous variations and modifications which may be made by those skilled in the art. Thus, the invention is to be construed as being limited only by the spirit and scope of the appended claims.
INDUSTRIAL APPLICABILITY
[0058] The invention has applicability to environmental control systems for stationary, automotive, and aerospace applications.
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The invention is a process for determining the charge level of a vapor cycle environmental control system, having a condenser, evaporator, and an expansion valve, comprising the steps of providing a neural network having four input neurons, two hidden neurons and one output neurons; determining the number of degrees below the saturation temperature of the liquid refrigerant exiting the condenser and providing this measurement to the first input neuron; sensing the condenser sink temperature and providing the measurement to the second input neuron; sensing either the refrigerant outlet temperature from the condenser or the evaporator exhaust air temperature and providing the measurement to the third input neuron, sensing the evaporator inlet temperature and providing the measurement to the fourth input neuron; and using the trained neural network to monitor the charge level in the system.
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TECHNICAL FIELD
The present invention relates to cleaning stations for use in electrophotographic print engines, and more particularly relates to an improved cleaning station having cleaning blades which are easily removed, cleaned, and replaced.
BACKGROUND OF THE INVENTION
Electrophotography refers to producing photographic images by electrical means, and xerography is a form of electrophotography for copying documents and other graphic matter. Xerographic copiers are extensively used in a variety of environments, such as offices, libraries, and educational institutions.
The basic elements of a xerographic copier are well known to those skilled in the art. A light source forms an electrostatic latent image of an original document on a photosensitive medium. The photosensitive medium, as it moves within the copier, travels adjacent a source of tiny plastic particles called toner. The electrostatic force of the latent image on the photosensitive medium attracts the toner, thereby providing a developed image of toner particles on the surface of the photosensitive medium. The toner image is transferred through electrostatic charges to an image receptor, which is normally a sheet of paper or plastic. The image receptor then passes through a heating device which melts the toner particles, thereby fixing or fusing the image of the original onto the image receptor.
After the toner image is transferred to the image receptor, some toner particles remain clinging to the surface of the photosensitive medium. Furthermore, toner is a fine powder and some toner particles become airborne within the xerographic copier and cling to the surface of the photosensitive medium as the copier operates. A cleaning station, set up adjacent to the photosensitive medium, removes the clinging toner before the next image is formed. Otherwise, the clinging toner would contaminate subsequent images formed on the photosensitive medium.
As is well known in the prior art, the cleaning station gradually becomes filled with toner and that toner must be removed. In order to remove the toner from a cleaning station, the cleaning station must be removed from the xerographic copier. In conventional xerographic copiers, access to the cleaning station is difficult. As a result, it is difficult to remove the cleaning station without spilling toner into the copier as the cleaning station is removed. The toner tends to become airborne when spilled, and this airborne toner settles throughout the copier, contaminating images formed on the photosensitive medium and causing abrasive damage to various moving parts.
As is also well known in the prior art, the cleaning element of the cleaning station gradually degrades and must be replaced. In conventional xerographic copiers, the cleaning station must be removed to replace the cleaning element. Therefore, the same problems discussed above are encountered when replacing the cleaning element.
More recently, laser printers have become popular office machines. As is known to those skilled in the art, laser printers are usually constructed with print engines which are similar to those used in xerographic copiers. A raster-scanned laser beam creates the latent image directly on the photosensitive medium in a laser printer. After the image is created on the photosensitive medium, the printing process is similar to that in a xerographic copier.
Therefore, there is a need in electrophotographic print engines or laser print engines for a cleaning station which is simpler to clean, remove, and replace without damaging other internal parts.
SUMMARY OF THE INVENTION
The present invention solves the above problems in the prior art in several significant aspects. Generally, the present invention includes an electrophotgraphic print engine comprising a first frame and a second frame connected to one another so that the print engine can be opened and closed. A photoreceptor medium housed in one of the first and second frames transfers toner and a cleaning element housed in the other frame cleans toner from the photoreceptor medium. The cleaning element is positioned next to the photoreceptor medium when the print engine is closed.
The novel construction of the present invention facilitates the removal of toner from the cleaning element and replacement of the cleaning element by allowing easy access to the interior of the electrophotographic print engine. To gain access to the cleaning element, the operator simply separates the first frame from the second frame. Because the photoreceptor medium is housed in one frame while the cleaning element is housed in the other frame, the photoreceptor medium separates from the cleaning element as the first and second frames are separated. Thus, the cleaning element is exposed and may be directly inspected, removed from the print engine, and then replaced. The ease of this operation allows sure handling of the cleaning element when removed from the print engine, thereby preventing the spillage of toner into the print engine. In addition, because the cleaning element is directly exposed, the toner removed by the cleaning element can be vacuumed with a conventional vacuum cleaner without removing the cleaning element from the print engine.
Stated somewhat more specifically, the first frame and second frame of the present invention are connected at one end by a hinge so the print engine may be opened by lifting one end of the first frame from the second frame and closed by pushing the same end of the first frame back down to the second frame. Also, the cleaning element is positioned in the print engine so that the cleaning blade initially contacts the flat outer surface of the photoreceptor medium at an angle substantially perpendicular to the outer surface when the print engine closes. This feature of the present invention reduces the wear on the photoreceptor medium caused by the cleaning blade striking the photoreceptor medium when the print engine closes. Because the cleaning blade strikes the flat surface of the photoreceptor medium at an angle substantially perpendicular to the photoreceptor medium, the resultant force of the contact is substantially perpendicular to the photoreceptor medium. Therefore, there is little or no side load on the cleaning blade at the point of initial contact, so the cleaning blade does not buckle under the photoreceptor medium nor does the cleaning blade stretch the flat surface of the photoreceptor medium.
Therefore, an object of the present invention is to provide an improved electrophotographic print engine.
Another object of the present invention is to provide an electrophotographic print engine wherein the cleaning elements are easily accessible for cleaning and replacement thereof.
Another object of the present invention is to provide an electrophotographic print engine wherein the damage to photoreceptor mediums caused by cleaning elements is reduced.
A further object of the present invention is to provide an electrophotographic print engine wherein used toner can be removed from cleaning elements and cleaning elements can be replaced with a minimum of toner dispersion.
Other objects, features, and advantages will become apparent from reading the following specification in conjunction with the accompanying drawings.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an open print engine, according to the preferred embodiment of the present invention.
FIG. 2 is a perspective view of a cleaning blade station, according to the preferred embodiment of the present invention. A fragmentary perspective view of a photoreceptor belt is shown in phantom.
FIG. 3 is a sectional side elevation view of the preferred embodiment of the cleaning blade station of the present invention illustrating the position of the cleaning blades and photoreceptor belt, a fragment of which is shown in phantom, when the print engine is open.
FIG. 4 is a fragmentary side elevation view of a cleaning blade initially contacting the photoreceptor belt as the print engine closes, according to the preferred embodiment of the present invention.
FIG. 5 is a sectional side elevation view of the preferred embodiment of the cleaning blade station of the present invention when the print engine is operating. A fragmentary elevation view of the photoreceptor belt is shown in phantom.
FIG. 6 is a sectional fragmentary perspective view of a cleaning blade station according to a preferred embodiment of the present invention enlarged to illustrate detail at one end of the cleaning blade and cleaning blade guide.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown generally in FIG. 1, the improved electrophotographic print engine 10 comprises an upper frame 12 and a lower frame 14 connected by a hinge 15 whereby the upper frame and lower frame can rotate relative to one another. This gives the print engine 10 a clam-shell like appearance and operation. The print engine 10 can be opened by applying an upward force to the end of the upper frame 12 opposite the hinge 15, thereby causing the upper frame to rotate about the hinge and lift from the lower frame 14. The print engine 10 can then be closed by applying a downward force to the end of the upper frame 12 opposite the hinge 15. The print engine 10 also includes a photoreceptor belt 18 which is positioned in the upper frame 12, so that the photoreceptor belt is exposed when the print engine is open. In addition, a photoreceptor belt cleaning station 20 is positioned in the lower frame 14 so that the cleaning blade station is exposed when the print engine 10 is open and is contacting the photoreceptor belt 18 when the print engine is closed.
Turning to FIGS. 2 and 3, the photoreceptor belt cleaning station 20 is shown generally comprising two cleaning blades 23 and 24 mounted on separate cleaning blade holders 26 and 27 contained in a cleaning blade housing 29. The cleaning blade housing 29 includes a rectangular flat bottom plate 32 (see FIG. 3) and two rectangular vertical plates 35 and 38 which extend upward from the opposite longitudinal edges of the flat bottom plates. A sloped edge 41 extends outwardly from the top longitudinal edge 42 of vertical plate 35. Another sloped edge 44 extends outwardly from the top longitudinal edge 45 of vertical plate 38. End plates 47 and 50 attached to the opposite ends of bottom plate 32 and the vertical plates 35 and 38 give the cleaning blade housing 29 a trough-like appearance.
The cleaning blade holders 26 and 27 each comprise a narrow rectangular member 53 which extends from end plate 47 to end plate 50. Each end 56 of the member 53 for each cleaning blade holder 26 and 27 fits intgrally within the rectangular cleaning blade guide channels 59 located in the end plates 47 (see FIG. 6) and 50. A narrow longitudinal rib 62 protrudes from one face of and runs the length of each cleaning blade holder 26 and 27, near the lower edge of each blade holder. Pegs 65 extend below the lower edge of each cleaning blade holder 26 and 27 at opposite ends of the cleaning blade holders. Each peg 65 fits into a corresponding spring 68 which rests on the bottom plate 32 of the cleaning blade housing. The springs 68 provide a positive force resiliently urging the cleaning blade holders 26 and 27 in the direction of the photoreceptor belt 18.
The cleaning blades 23 and 24 each comprise a flat and narrow rectangular strip of flexible material which extends along the length of the cleaning blade holders 26 and 27. The lower edge 74 of each cleaning blade 23 and 24 rests on top of the narrow rib 62 protruding from each corresponding cleaning blade holder 26 and 27, and the flat surface of each cleaning blade rests against the flat surface of the cleaning blade holder. The cleaning blades 23 and 24 are preferably secured to the cleaning blade holders 26 and 27 with an adhesive. The top edge 77 of each cleaning blade 23 and 24 extends above and beyond the top edge 80 of the respective cleaning blade holders 26 and 27 towards the photoreceptor belt 18 as shown in FIGS. 3 and 5.
The photoreceptor belt cleaning station 20 also includes an auger 83 which extends from end plate 47 to end plate 50 parallel and proximate to the cleaning blades 23 and 24. Rounded ends 86 extend from each end of the auger 83 and fit into holes 89 in the end plates 47 and 50. One auger end 86 engages a drive mechanism (not shown) which rotates the auger. A rounded auger dish 92 extends inwardly from the top edge 42 of the vertical plate 35 at one side of the cleaning blade housing 29. The inner surface of the auger dish 92 closely conforms to the surface of the auger 83 and extends below the auger (see FIGS. 3 and 5).
The cleaning blade housing 29 and the cleaning blade holders 26 and 27 preferably comprise a light metal, such as aluminum, or a plastic. Also, the cleaning blades 23 and 24 preferably comprise a flexible elastomeric material such as rubber.
When the print engine 10 is in operation, as shown in FIG. 5, the print engine is closed and therefore, the upper edges 77 of the cleaning blades 23 and 24 are in contact with the outer surface of the photoreceptor belt 18. As the print engine operates, the photoreceptor belt 18 travels in a clockwise direction, as seen in FIG. 5, and slides across the upper edge 77 of each of the cleaning blades 23 and 24. As a result, the residual toner 95 on the outer surface of the photoreceptor belt 18 is removed by the cleaning blades 23 and 24.
The majority of toner 95 removed from the photoreceptor belt 18 by the first cleaning blade 23 falls onto the auger 83 and into the rounded auger dish 92. As the auger 83 rotates, it carries the used toner 95 to an opening (not shown) in the rounded auger dish 92 where the used toner 95 falls into a receptable (not shown). The auger 83 thus removes most of the used toner 95 from the cleaning blade station 20; nevertheless, some toner 95 removed by the first cleaning blade 23 and all of the toner removed by the second cleaning blade 24 collects on the bottom plate 32 of the cleaning blade station.
Returning to FIG. 1, a particular advantage of the print engine 10 can be seen in that the photoreceptor belt cleaning station 20 is exposed and easily accessible when the print engine is open (see also FIG. 3). When the upper frame 12 is lifted from the lower frame 14, the photoreceptor belt is lifted as well while the photoreceptor belt cleaning station 20 remains in the lower frame. The cleaning blades 23 and 24 thus are directly exposed for inspection, removal, and/or replacement without removing the entire cleaning blade station 20 from the print engine 10. In addition, the used toner 95 caught in the cleaning blade housing 29 can be vacuumed without removing the cleaning blade station 20.
Turning to FIG. 4, another particular advantage of the print engine 10 can be seen. The cleaning blades 23 and 24, the cleaning blade holders 26 and 27, and the cleaning blade guides 59, are set an angle from the vertical; this angle is 15° in the preferred embodiment, although the exit angle is not critical. The upper frame 12 is positioned relative to lower frame 14 so that when the upper frame 12 of the print engine 10 is moved down toward the lower frame 14, the photoreceptor belt 18 initially contacts the upper edges 77 of the cleaning blades 23 and 24 at a substantially perpendicular angle (see FIG. 4). As a result, at the point of initial contact, the angle of force from the contact is parallel to the height of the cleaning blades 23 and 24 and the cleaning blade guides 59. Thereafter, as the upper frame 12 is further lowered and secured to the lower frame 14, the cleaning blades 23 and 24 retract (see figure 5), sliding down the cleaning blade guides 59 against the force of the springs 68 with a minimal side load exerted on the cleaning blades 23 and 24 and a minimal component of force in the direction parallel to the surface of the photoreceptor belt 18. As a result, the cleaning blades 23 and 24 are less likely to bind under the photoreceptor belt 18 and detach from the cleaning blade holders and are less likely to stretch and damage the surface of the photoreceptor belt.
It should be understood that the foregoing relates only to a preferred embodiment of the present invention, and that numerous changes and modifications therein may be made without departing from the spirit and scope of the invention as defined by the following claims.
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Improved cleaning stations for use in electrophotographic print engines having cleaning elements which are simple to inspect, remove, clean, and replace. The photoreceptor belt cleaning station is positioned in one frame of the print engine and the photoreceptor medium is positioned in the other frame of the print engine so that the cleaning station is directly accessible when the print engine is open. Also, when the print engine is closed, the photoreceptor medium contacts the cleaning elements at a substantially perpendicular angle resulting in minimum stress to both the photoreceptor medium and the cleaning elements.
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This application is a National Stage Entry of International Application No. PCT/US2008/011582, filed Oct, 8, 2008, and claims the benefit of Japanese Application No. 2007-271975, filed on Oct. 19, 2007, which is hereby incorporated by reference for all purposes as if fully set forth herein.
FIELD OF THE INVENTION
The present invention relates to a display panel with pixels arranged in a matrix shape, and to a pixel circuit for such a display panel.
BACKGROUND OF THE INVENTION
With a display device that uses current drive type light emitting elements, such as an OLED, power supply lines are normally arranged inside a pixel region, driving elements and elements to be driven, such as the OLED, are connected between the power supply lines, and a desired display image is obtained by controlling the conductance of the driving elements. In the case of using a transistor as a drive element (driving transistor), the source terminal of that driving transistor is connected to one power supply, and by applying a voltage corresponding to display data to the gate terminal of the driving transistor a current corresponding to the voltage across the gate and source of the driving transistor is supplied to the OLED, being a driven element, and a desired display image is obtained.
FIG. 1 shows the overall structure of a display device of the related art. Unit pixels (pixels) 2 are arranged in a matrix shape in a pixel region 1 . Scan lines 3 are arranged in correspondence with each row of pixels 2 , and signal lines 4 and power supply lines 5 are provided in correspondence with each column of unit pixels 2 . The scan lines 3 are driven by a scan line driving circuit 6 , the signal lines 4 are driven by a signal line driving circuit 7 , and the power supply lines 5 are driven by a power supply voltage circuit 8 .
In response to signals from a control circuit 9 the scan line drive circuit 6 selects one scan line, and the signal line drive circuit 7 supplies a signal for the pixel being selected to the signal line 4 . By repeating this, signals corresponding to each pixel are written. A power supply voltage is always supplied to the power supply lines 5 .
FIG. 2A shows a representative pixel circuit for the case of a P-type transistor as the driving transistor. One end of a switch SW 1 formed by a transistor is connected to the signal line 4 , and the other end of the switch SW 1 is connected to a gate terminal of a driving transistor T DR . The source of the driving transistor T DR is connected to a power supply line 5 that supplies a power supply voltage Vdd. Here, the resistor R L is the wiring resistance of the power supply line 5 . Also, a data holding capacitor Cs is connected between the source and gate of the driving transistor T DR , and the drain of the driving transistor T DR is connected to an anode of an OLED. The cathode of the OLED is connected to ground etc., being a low voltage power supply.
As a result, a voltage corresponding to Vdd−Vdata is written to the data holding capacitor Cs by turning the switch SW 1 on, a current corresponding to Vdata flows in the driving transistor T DR , and the OLED emits light using that current.
If the current flowing in the power supply line 5 is large, variation arises in the power supply voltage Vdd due to the resistance of the power supply line 5 . Since the voltage stored in the data holding capacitor Cs at this time is lowered, the emission brightness of the pixel is lower than the intended brightness. In order to deal with this type of problem, a conventional method has aimed to reduce variation in the voltage of the power supply line itself. In order to reduce voltage variation in the power supply line, it has been considered to lower the resistance of the power supply line itself (for example, JP 2007-241302), or to turn off the flow of current in the driving transistor in a pixel selection period (for example, U.S. Patent Application Publication No. 2007/0128583).
With the method of patent document 1 described above, there can be a limit to the lowering of the resistance value of the power supply line, which basically has no solution. Also, with the method of U.S. Patent Application Publication No. 2007/0128583, since the source electrode of the driving transistor is floating during the pixel selection period, it is difficult to accurately write a signal voltage across the gate and source of the driving transistor.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a display device that suppresses variation in pixel current due to potential variation in a power supply voltage, and has good display characteristics.
The present invention is directed to a display device in which a plurality of pixels are arranged in a matrix form corresponding to intersections of a plurality of data lines and a plurality of scan lines, wherein each pixel includes a light emitting element having a first electrode connected to a first power supply and which emits light according to a current that flows in an element, a driving transistor having a source electrode connected to a second power supply and which supplies a drain current to a second electrode of the light emitting element, a data storage capacitor having a first electrode connected to a gate electrode of the driving transistor, and a first switch which is switched ON during a pixel selection period so that data of a data line is written to the data storage capacitor, and wherein a potential of a second electrode of the data storage capacitor is changed between at least a partial period in a pixel selection period and at least a partial period in a pixel non-selection period.
Also, it is preferable to further have a second switch for controlling connection between the second power supply and the second electrode of the data storage capacitor, and for the second electrode of the data storage capacitor and a reference power supply that is different from the second power supply to be connected via a resistance.
Also, if a resistance between the data storage capacitor and the reference power supply is made R LR , an on resistance of the second switch is made Ron, and a number of pixels, in whichever of the horizontal or vertical direction of the display device has fewer pixels, is made M, to satisfy a relationship Ron<R LR ×M/40.
Further, it is preferable to further have a second switch for controlling connection between the second power supply and the second electrode of the data storage capacitor, and to have a third switch for controlling connection between the second electrode of the data storage capacitor and a reference power supply that is different from the second power supply.
Also, if on resistance/off resistance, being a ratio of the on resistance to the off resistance of the second switch, is made R 2 , and on resistance/off resistance, being a ratio of the on resistance to the off resistance of the third switch, is made R 3 , it is preferable to satisfy a relationship R 2 ×R 3 <0.01.
It is also preferable for the second switch and the third switch to be thin film transistors provided inside a pixel region.
It is also preferable for the second switch to be a thin film transistor provided inside a pixel region, and for the third switch to be a transistor provided outside a pixel region.
It is also preferable for a reference potential line, connecting the second electrode of the data storage capacitor and the reference voltage, to be orthogonal to the second power supply line.
It is also preferable for a reference potential line, connecting the second electrode of the data storage capacitor and the reference voltage, to be orthogonal to the scan direction of the scan lines.
It is also preferable for the data storage capacitance to be larger that a parasitic capacitance, which is a capacitance arising at the gate/source region of the driving capacitor excluding the data holding capacitance.
It is also preferable to compensate for the influence on the write voltage with the variation in power supply voltage by changing the potential of the second electrode of the data storage capacitor between at least a partial period in a pixel selection period and at least a partial period in a pixel non-selection period.
The present invention is also directed to a pixel circuit for a display device in which a plurality of pixels are arranged in a matrix form, including a light emitting element having a first electrode connected to a first power supply and which emits light according to a current flowing in an element, a driving transistor having a source electrode connected to a second power supply and which supplies a drain current to a second electrode of the light emitting element, a data storage capacitor having a first electrode connected to a gate electrode of the driving transistor, and a first switch which is switched ON during a pixel selection period so that data of a data line is written to the data storage capacitor, and wherein a potential of a second electrode of the data storage capacitor is changed between at least a partial period in a pixel selection period and at least a partial period in a pixel non-selection period.
According to the present invention, it is possible to write correct data to a data storage capacitor, even if there is a change in the potential of a second electrode of the data storage capacitor depending on the wiring resistance of power supply lines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing showing the overall structure of a display device of the related art;
FIG. 2A is a drawing showing the structure of a pixel circuit of an embodiment;
FIG. 2B is a waveform diagram and a timing chart for describing operation;
FIG. 3A is a drawing for describing operation at the time of scan line selection;
FIG. 3B is a drawing for describing operation at the time of scan line non-selection;
FIG. 4 is a drawing showing a pixel circuit of specific example 1;
FIG. 5 is a drawing showing the overall structure of specific example 2;
FIG. 6 is a drawing showing a pixel circuit of specific example 2; and
FIG. 7 is a drawing showing a pixel circuit of specific example 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A pixel circuit and a display device of embodiments of the present invention will now be described based on the drawings. A pixel circuit of this embodiment is shown in FIG. 2A . In FIG. 2A , a P-type driving transistor has been used, but an N-type driving transistor can also be adopted in exactly the same way in the present invention by simply reversing the polarities.
The pixel circuit of the present invention has a structure where a source electrode of the driving transistor T DR is connected to one power supply line (voltage Vdd), a switch SW 1 for data voltage writing, and on/off controlled by a scan line 3 , is connected to the gate electrode of the driving transistor T DR , and one electrode of a data storage capacitor Cs is connected to the gate electrode of the driving transistor T DR . The voltage across the gate and source of the driving transistor due to lowering of the power supply line voltage is then compensated for, and pixel current prevented from decreasing, by varying the potential of the other electrode voltage (reference electrode) of the data storage capacitor Cs in accordance with voltage drop of the power supply voltage, between a scan line select period and a scan line non-select period.
Specifically, the switch SW 2 is provided, by performing switching with this switch SW 2 so as to connect a reference electrode potential for the data storage capacitor Cs to a particular constant potential (in this example, a reference potential Vref of the reference potential line) during a scan line selection period, and connect to a power supply line 5 of lowered voltage (power supply line 5 of an appropriate pixel section lowered in voltage due to the wiring resistance R L ) in a scan line non-selection period, the gate electrode potential of the driving transistor T DR is varied in proportion to lowering of voltage due to the wiring resistance R L of the power supply line 5 , and the potential across the gate and source of the driving transistor T DR can be held at the intended voltage.
That is, as shown in FIG. 2B , when the switch SW 1 is turned on, data of the appropriate pixel is supplied as Vdata. At that time, the switch SW 2 selects the reference voltage Vref. Then, after the switch SW 1 is turned off, the switch SW 2 selects the power supply line 5 , namely, Vdd−ΔV.
The pixel control circuit has each pixel formed on a substrate, and the driving transistor T DR , switch SW 1 and switch SW 2 constructed using thin film transistors.
Next, operation of the circuit of FIG. 2 will be described in detail using FIG. 3A and FIG. 3B . In this embodiment also, a P-type driving transistor T DR is assumed, but in the case of an N-type driving transistor also operation becomes exactly the same simply by reversing the polarities.
Specifically, an N-type driving transistor would be arranged at the cathode side of the OLED, and it becomes possible to compensate for lowering of voltage due to the wiring resistance arising between the source electrode and ground of the driving transistor.
If a pixel is selected by a scan line 3 , as shown in FIG. 3A , the switch SW 1 is turned on and a data voltage Vdata is written to the gate (node a) of the driving transistor T DR . At that time, the switch SW 2 is connected to reference potential Vref, the potential Vb of the source (node b) of the driving transistor T DR becomes Vref, and a voltage (Vdata−Vref) is stored in the data storage capacitor Cs.
After the scan line 3 is de-selected and the switch SW 1 is turned off, if the switch SW 2 is switched to the power supply line 5 side, as shown in FIG. 3B , potential Vb becomes Vdd−ΔV by subtracting the extend of voltage lowering ΔV from the power supply voltage Vdd. If the overall capacitance around node a is made Call, then the potential Va of node a becomes Va=Vdata+Cs/Call×(Vdd−ΔV−Vref), while the voltage Vgs across the gate and source of the driving transistor T DR becomes Vgs=Vdata−Cs/Call×Vref−(1−CS/Call)×(Vdd−ΔV).
If the data storage capacitor Cs is sufficiently large compared to the parasitic capacitance around node a, it is possible to make Cs=Call, and as shown in FIG. 2B , Vgs becomes equal to Vdata−Vref, and Vgs becomes a value that does not depend on the extent of voltage drop ΔV of the power supply line 5 . The drain voltage of the driving transistor T DR is mainly determined by Vgs in the saturation region, which means that it is possible to supply a pixel current to the OLED that corresponds to the desired voltage and is not dependent on the extent of voltage drop ΔV.
The parasitic capacitance around node A cannot be ignored with respect to Cs, and for example, even with Cs about the same as the parasitic capacitance, if Cs=0.5×Call is assumed then Vgs=Vdata−0.5×(Vref+Vdd−ΔV), and the effect of being able to suppress the effect of the voltage drop of the power supply line to half can be expected.
Actually, the switch SW 2 does not have to be a physical switch, and various configuration can be considered, as shown in the following specific examples.
SPECIFIC EXAMPLE 1
FIG. 4 shows the structure of a pixel circuit of specific example 1, and control lines and power supply lines connected to this pixel circuit.
With specific example 1, as well as arranging reference potential lines 10 for supplying the reference voltage Vref to each pixel, scan lines 11 and switches SW 3 are also provided in addition to switches SW 2 . A scan line 11 is set to a select level (H level) at the time of non-selection of a scan line 3 (L level period), with the scan line 3 connected to the gate of switch SW 3 and the scan line 11 connected to the gate of switch SW 2 . In this way, the reference electrode potential for the data storage capacitor Cs is controlled to the reference voltage Vref at the time of data writing, and to the power supply potential Vdd of the power supply line 5 at the time of scan line non-selection. It is also preferable to use thin film transistors for the switches SW 2 and SW 3 .
In FIG. 4 , N-type TFTs have been used as the switches SW 2 and SW 3 , but it is also possible to use P-type or a combination of N-type and P-type transistors. Also, switching of the reference electrode potential for the data storage capacitor Cs is preferable carried out after completion of writing the data voltage Vdata to the data storage capacitor Cs.
The voltage Vgs across the gate and source of the driving transistor T DR becomes Vdata−Cs/(Cs+Cp)Vref−Cp/(Cs+Cp)×(Vdd−ΔV), and the effect of the voltage drop ΔV of the power supply line Vdd is reduced by a factor of Cp/(Cs+Cp). Incidentally, Cp is the parasitic capacitance around node a, and Call=Cs+Cp. Accordingly, a capacitance value of the data storage capacitor Cs is preferable made sufficiently large compared to the parasitic capacitance Cp connected around the gate node of the driving transistor.
SPECIFIC EXAMPLE 2
FIG. 5 is an overall structural drawing of a display device of specific example 2. FIG. 6 shows a circuit diagram, extracted from a pixel section of specific example 2 and related peripheral sections.
The overall structure of the display device is the same as FIG. 3 . The power supply lines Vdd are arranged in the signal line direction while the reference potential lines 10 are arranged in the scanning line direction, and the reference potential electrode of the data storage capacitor Cs is directly connected to the reference potential line 10 . The reference potential line 10 is connected via the switch SW 3 to the reference potential Vref outside the pixel region 1 . The power supply line Vdd and the reference potential line 10 are connected by the switch SW 2 inside each pixel.
At the time of data write the scan line 3 is selected, and at the same time the switch SW 3 is turned on. At this time switch SW 2 is off, and substantially no current flows in the reference potential line 10 . As a result, the reference electrode potential Vb of the data storage capacitor Cs is substantially the reference potential Vref(Vb=Vref). Next, after de-selection of the scan line 3 , the scan line 11 is selected and the switch SW 2 is turned on. The reference electrode potential Vb of the data storage capacitor CS becomes almost the same as the potential Vdd−ΔV of the power supply line Vdd at the pixel connection point, and the potential of the gate node a of the driving transistor T DR is also changed via the data storage capacitance. As a result, the potential Vgs across the gate and source of T DR becomes Vdata−Cs/(Cs+Cp)Vref−Cp/(Cs+Cp)×(Vdd−ΔV). Here, when the data storage capacitor Cs is sufficiently large compared to the parasitic capacitance Cp, the voltage Vgs across the gate and source of T DR becomes the voltage Vgs=Vdata−Vref that is not dependent on the voltage drop of in this pixel. Since the reference potential line 10 uses the power supply voltage Vdd at the time of selection of the scan line 11 , the reference potential Vref is preferably the same as the power supply voltage Vdd, or almost the same potential. When the on and off resistances of the switches SW 2 and SW 3 are respectively made r 2 on, r 2 off, r 3 on and r 3 off, they are preferably designed so as to give the following relationship:
r 2on× r 3on/ r 2off/ r 3off<0.01
Here, if a ratio of the on resistance and the off resistance (on resistance/off resistance) of the switch SW 2 is represented by R 2 , and a ratio of the on resistance and the off resistance (on resistance/off resistance) of the switch SW 3 is represented by R 3 , the above equation is represented by R 2 ×R 3 <0.01.
By setting the on and off resistances in this way, it is possible to set the potential of the reference electrode of the data storage capacitor Cs when the switch SW 2 is on to a voltage according to the power supply voltage Vdd, and when the switch SW 3 is on set the potential of the reference electrode of the data storage capacitor Cs to the reference potential Vref.
SPECIFIC EXAMPLE 3
FIG. 7 shows the structure of a pixel circuit, control lines and power supply lines of specific example 3. The overall structure of specific example 3 is the same as FIG. 5 . The switch SW 3 connecting the reference potential line 10 to the reference voltage Vref in specific example 2 has been removed, and the reference potential line 10 is directly connected to the reference potential Vref. This reference potential line 10 is connected to the reference power supply Vref via a resistance R LR . Accordingly, when the switch SW 2 is on, the power supply Vdd and the reference power supply Vref are connected via resistance R LR and the on resistance of switch SW 2 .
In this case, it is preferable to design so that the on resistance r 2 on of the switch SW 2 , with respect to the resistance R LR of the reference potential line 10 , becomes as follows:
r 2on< R LR ×M/ 10
Also, it is more preferable to further set so that r 2 on<R LR ×M/40. By setting these values in this way, it is possible to set so as to switch the potential of the reference electrode of the data storage capacitor Cs when the switch SW 2 is on to a voltage corresponding to the power supply voltage Vdd, and to the reference potential Vref. Here, M is the number of pixels in the horizontal direction. In the case of specific example 3, since the switches SW 2 are on for all pixels in the horizontal direction, and connected to power supply Vdd, then the resistance to the power supply Vdd becomes substantially smaller as the number of pixels increases. In the case of arranging the reference potential lines 10 in the vertical direction, it is preferable to adopt the number of pixels in the vertical direction for M, or to adopt the number of pixels in the direction having least pixels.
Parts List
1 pixel region 2 unit pixels 3 scan lines 4 signal lines 5 power supply lines 6 line driving circuit 7 line driving circuit 8 power supply voltage circuit 9 control circuit 10 reference potential lines 11 scan lines
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A display device in which a plurality of pixels are arranged in a matrix form, corresponding to intersections of a plurality of data lines and a plurality of scan lines, wherein each pixel includes a light emitting element having a first electrode connected to a first power supply and which emits light according to a current that flows; a driving transistor having a source electrode connected to a second power supply and which supplies a drain current to a second electrode of the light emitting element; a data storage capacitor having a first electrode connected to a gate electrode of the driving transistor; and a first switch which is switched ON during a pixel selection period so that data of a data line is written to the data storage capacitor, and wherein a potential of a second electrode of the data storage capacitor is changed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a filler applicable to degradable plastics considered to be available for the purpose of global environmental protection and a process for producing the same. More specifically, the filler is produced by using a filler, such as an extender pigment, e.g., calcium carbonate, and clay; an inorganic or organic pigment, e.g., titanium oxide, iron oxide, and phthalocyanine green, as a carrier material, adsorbing effective biodegradable and/or photodegradable component(s), such as starch, benzophenone, anthraquinone, transition metal salts, and oxidization accelerators, on the particle surface of the filler, as a uniform coating, via a surface treating agent, such as, a silane coupling agent, a fatty acid, a resin acid, or a salt thereof, after which the surface-treated filler is kneaded and filled in the plastics thereby uniformly dispersing the plastic-degradable effective component(s) in the plastics so as to be effectively put into practice.
2. Description of the Prior Art
Various environmental conditions on the earth are not permanent conditions imparted by humans, but are balanced in a closed ecological systems, "the earth", constructed and maintained as the result of life activities taking place over several billions of years since the beginning of life. For this reason, there never has been an inexhaustible capacity which admits all kinds of human activity which ignore the cartulary system. Consequently, essentially unlike naturally originating products such as wood and paper, having a cartulary cycle in the natural environment, artificial products, such as plastics, which are not part of the circulatory system in the environment, are impossible to assimilate into the environment after being diffused into the environment. Also, it is very difficult to carry out such activity as artificial treatments and recovery. These are the reasons why plastic degradation measures become a necessary proposition.
Recently, global environmental problems, such as atmospheric and ocean pollution, have been exposed. Measures for treating disposal products of plastics which are yearly produced in an amount of about one hundred million tons have been taken up globally. For these measures, filling up, burning up, recycling the disposal products, and other measures have been put into practice. However, these measures have not yet achieved essential settlement and, thus, for the moment, decrease in volume by the introduction of degradable plastics and apparent disappearance by their spontaneous purification have been attempted. In several countries, the examination has already been made to enforce rules and regulations, such as regulations for using non-degradable plastics and taxation of their use.
Plastics have excellent workabilities, and are suitable for mass production, are light, have high weather and chemical resistances, are easy to be colored, and have good decorative properties, in comparison with metals such as iron. Recently, plastics having improved in terms of physical/mechanical/thermal properties due to so-called engineering plastics have been developed. The total amount of plastic production in Japan has been increasing year by year and has now reached twelve million tons per year. Their application fields are very wide, i.e., they are used in industrial parts, automobiles, electrical household appliances, daily necessities, miscellaneous goods, and many other applications. Plastics are indispensable and useful for our lives as described above, but their non-degradability has been criticized not only as a source of environmental pollution but also as a major cause of global environmental problems. Accordingly, the development of degradable plastics have been strongly needed.
At present, degradable plastics have roughly been classified according to their degradation mechanism into biodegradable and photodegradable plastics. Furthermore, in the biodegradable plastics, degradable plastics in a narrow sense where polymers themselves are degraded by utilizing enzymes or microorganisms and biological breaking down plastics in which starch, etc. are incorporated in plastics and said starch, etc., are degraded to loose the forms of plastics themselves have been known. The term "photodegradable plastics" is intended to means plastics which are degraded by irradiating sun light, ultraviolet, etc. From the technical standpoint, those in which photodegradable groups, such as carbonyl, are introduced and those to which effective components, such as transition metal salts, oxidization accelerators, and photosensitizers, are added to impart photodegradabilities have been known. In any case, the most important problems are that these effective components are uniformly dispersed on the plastics.
In order to impart degradability to the plastics, in many cases, effective components are added in amounts ranging from 0.001 to 80 or 90 parts by weight based on the resin in spite of their degradation mechanism. Up to now, methods in which these components are kneaded separately from the fillers, such as a method involved in utilizing a master batch containing effective components, are applied as the addition method. However, conventional methods have poor operability, and are disadvantageous in that effective components can be uniformly mixed in products only with difficulty. Of these, since effective components cannot be uniformly mixed, these methods have serious problems that the effective components cannot be put into practice effectively, which leads to deteriorate quality such as deterioration in strength.
SUMMARY OF THE INVENTION
In light of the above-enumerated problems, the present invention has been made, the object of which is to simplify the production stages of degradable plastics and, at the same time, to stabilize the quality of plastic products. Thereby, the present invention proposes a technique notably important in measure for treating plastics which has brought on problems from the global environmental viewpoint. That is, according to the present invention, since a filler for degradable plastics with effective component(s) having plastic-degradabilities adsorbed on the surfaces of filler particles to uniformly disperse the filler on them are provided, the stages for producing degradable plastics can be simplified. What is more, since the effective component(s) can be uniformly dispersed, their plastic-degradabilities can be exhibited effectively, and the quality of the products are stabilized, making it possible to use smaller amounts of the effective component(s).
In order to attain the above-described object, the present filler for degradable plastics is comprised of a filler used for plastics and having biodegradable and/or photodegradable effective component(s) adsorbed on the particles of the filler via a surface treating agent. The significance of its construction and actions will clearly be understood by the following explanation.
That is, when an extender/color pigment, e.g., calcium carbonate, clay, talc, mica, titanium oxide, iron oxide, phthalocyanine green, ethylene tetrafluoride, carbon black, etc., is filled, an organic or inorganic surface treating agent, used for the purpose of improving the dispersibilities of the filler and the affinities between the degradable plastics and the filler, and plastic-degradable effective component(s), in order to uniformly disperse the components over the entire surfaces of the filler particles having extended surface areas, are added to the filler to produce a filler for degradable plastics. The present filler is then filled in the plastics, thereby making it possible to uniformly disperse the effective components which impart degradability to the plastic products. The details will be explained hereinbelow.
The filler to be used may be inorganic or organic, and are not specifically restricted. However, that in which the filler itself can easily be degraded in a normal environment is more preferable. For example, carbonate represented by calcium carbonate and magnesium carbonate; and hydroxide represented by aluminum hydroxide and magnesium hydroxide are easily degraded spontaneously in a normal environment, particularly an acidic environment, so they are the optimum fillers to be used for producing degradable plastics.
The kind of plastic degradable effective component is not specifically restricted but includes starch, powder of leather and vegetable fiber such as pulp which are used in the biodegradable plastics; ketone, such as benzophenone, and acetophenone, quinone, such as anthraquinone, transition metal salts such as cobalt naphthanate, oxidation accelerators, photosensitizers, which are added to photodegradable plastics; and the like. These effective components are utilized individually or in combination of two or more thereof. Usually, in order to enhance the affinity with plastics and to improve the dispersibility of the fillers, various surfactants inclusive of a silane coupling agent, a metal soap, a fatty acid or a resin acid are used to carry out surface treatment in either a dry or a wet process. Utilizing this stage, the above-described effective components which promote the decomposition of the plastics are added.
Concerning the amount of the component added, 10 to 200% by weight, preferably 30% by weight or more in order to obtain a sufficient effect, are added for starch, 0.1 to 10% by weight, usually 0.5 to 5% by weight for ketone such as benzophenone or quinone such as anthraquinone, or 0.01 to 40% by weight, usually 0.1 to 20% by weight for transition metal salts, oxidation accelerators, photosensitizers and so on. In the technique where these plastic degradable effective components are mixed in the surface treating agent in advance, and the surface treating agent containing the effective components are added to the filler or a suspension thereof at the stage of the surface treatment (1), or the surface treatment agent and the effective components may be added simultaneously (2), or the effective components are added before or after the surface treatment stage (3), for example, in the case of starch, the fillers and the starch are respectively coated with the same treating agent, whereby both of them are meaningfully mixed with each other. With respect to the effective components which are added in a relatively smaller amount, these effective components and the surface treating agent are uniformly adsorbed and dispersed on the surfaces of the filler particles. That is, in the present invention, since the plastic-degradable effective components are mixed with the filler during, before or after the surface treatment which has been carried out conventionally, the plastic-degradable effective components are uniformly adsorbed on the surfaces of the filler particles. Thereafter, the surface-treated filler is kneaded and filled in the plastics. This makes it possible to effectively utilize the plastic degradable effective components. Furthermore, as an additional method which can be anticipated to obtain a similar effect, a method in which the plastic degradable effective components are kneaded in plasticizers such as dioctylphthalate (DOP) can be considered.
In the filler for degradable plastics produced by the method of the present invention, the effective component which degrades plastics is uniformly adsorbed on the surface of the filler particles. When the fillers are used in the production of articles, degradability can be imparted to the plastics without requiring any special stage and, what is more, the effective component can be uniformly dispersed in the articles without unevenness. Consequently, the filler of the present invention possesses remarkable merits such as savings due to decreased amount of effective component added, which cannot be obtained by the conventional methods. Above all, calcium carbonate, which is relatively inexpensive and possesses an ability to neutralize acid, is also effective as a measure against acid rain and acidic soil.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Examples 1-22 describe the present invention. Comparative Examples 1-6 are examples of the prior art. Referential Examples 1-5 illustrate the degradation of specimens of the present invention as compared to specimens of the prior art.
EXAMPLE 1
To 20 kg of a wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight was added 1 kg of corn starch, and the mixture was thoroughly stirred and mixed. The slurry comprised of the colloidal calcium carbonate and corn starch was surface-treated by adding 600 g of a solution of 10% strength sodium salt of fatty acid, and it was dried and pulverized to produce a filler for degradable plastics.
EXAMPLE 2
To 20 kg of a wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight was added a mixture in which 1 kg of corn starch has been previously added to 600 g of a solution of 10% strength sodium salt of fatty acid, followed by stirring so as to carry out a surface treatment. This was dried and pulverized to produce a filler for degradable plastics.
EXAMPLE 3
To 20 kg of a slurry of phthalocyanine green with a specific surface area of 40 m 2 /g having a solid concentration of 10% by weight was added a mixture in which 1 kg of corn starch had been previously added to 500 g of a solution of 10% strength sodium salt of fatty acid, followed by stirring so as to carry out a surface treatment. This was dried and pulverized to produce a filler for degradable plastics.
EXAMPLE 4
Corn starch (0.75 kg) was added to 1.2 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g, and the mixture was then incorporated in a 10 l volume Henschel mixer to be mixed for 20 minutes. A sodium salt of fatty acid (29 g) was incorporated therein, and the mixture was again mixed in the Henschel mixer for another 10 minutes, to produce a filler for degradable plastics.
EXAMPLE 5
To 1.2 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g was added a mixture of 0.75 kg of corn starch and 29 g of sodium salt of fatty acid having been mixed and stirred previously. The mixture was incorporated in a 10 l volume Henschel mixer, and then mixed for 40 minutes, to produce a filler for degradable plastics.
EXAMPLE 6
A solution (1.2 kg) of 10% strength sodium salt of fatty acid was added to 20 kg with a wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight to carry out a surface treatment. It was filtered dried, pulverized, and 1 kg of corn starch was added thereto. The mixture was mixed in a Henschel mixer for 30 minutes, thereby to produce a filler for degradable plastics.
EXAMPLE 7
A sodium salt of fatty acid (54 g) was added to 1.2 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g, the mixture was then incorporated in a 10 l volume Henschel mixer to be mixed for 10 minutes to carry out surface treatment. Corn starch (0.75 kg) was incorporated therein, and the mixture was again mixed in the Henschel mixer for another 20 minutes, to produce a filler for degradable plastics.
EXAMPLE 8
A 10 l volume Henschel mixer was charged with 0.5 kg of corn starch and 15 g of sodium salt of fatty acid, and the contents were stirred and mixed for 30 minutes. Subsequently, 1.0 kg of talc having a specific surface area of 13 m 2 /g was added thereto, and the mixture was again stirred for another 10 minutes, to produce a filler for degradable plastics.
EXAMPLE 9
To 20 kg of a slurry containing aluminum hydroxide with an average particle size of 8 microns having a solid concentration of 10% by weight was added 1 kg of corn starch, and the mixture was stirred and mixed. Furthermore, 100 g of an aqueous 10% solution of a silane coupling agent was added the mixture and thoroughly stirred. The mixture was dried and pulverized, thereby producing a filler for degradable plastics.
EXAMPLE 10
To a mixture of 0.8 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g and 0.4 kg of aluminum hydroxide with a specific surface area of 7 m 2 /g was added 0.75 g of corn starch, and the mixture was incorporated in a 10 l volume Henschel mixer and mixed for 20 minutes. To this mixture were added 29 g of sodium salt of fatty acid, followed by stirring for 10 minutes in the mixer to carry out surface treatment, thereby producing a filler for degradable plastics.
EXAMPLE 11
To 20 kg of a wet synthesized slurry of colloidal calcium carbonate of a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight were continuously added 600 g of a solution of 10% strength sodium salt of fatty acid and 20 g of anthraquinone and 20 g of benzophenone to carry out surface treatment. Drying and pulverizing this gave a filler for degradable plastics.
EXAMPLE 12
To 20 kg of a wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight was added a mixture in which 40 g of anthraquinone had been previously added to 600 g of a solution of 10% strength sodium salt of fatty acid, followed by stirring so as to carry out a surface treatment to calcium carbonate particles. This was dried and pulverized to produce a filler for degradable plastics.
EXAMPLE 13
To 20 kg of a slurry of phthalocyanine green with a specific surface area of 40 m 2 /g having a solid concentration of 10% by weight was added a mixture in which 50 g of anthraquinone had been previously added to 0.5 kg of a solution of 10% strength sodium salt of fatty acid, followed by stirring so as to carry out a surface treatment. This was dried and pulverized to produce a filler for degradable plastics.
EXAMPLE 14
A 10 l volume of Henschel mixer was charged with 2.4 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g, 21 g of sodium salt of fatty acid, 30 g of anthraquinone, and 30 g of benzophenone, followed by mixing them for 10 minutes, to produce a filler for degradable plastics.
EXAMPLE 15
To 20 kg of wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid content of 8% by weight were added 600 g of a solution of sodium salt of 10% strength fatty acid, whereby the surface of the colloidal calcium carbonate was treated, followed by drying and grinding. Thereafter, 40 g of anthraquinone were added thereto, and the mixture was mixed in a Henschel mixer for 10 minutes, thereby to obtain a filler for degradable plastics.
EXAMPLE 16
2.4 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g and 48 g of sodium salt of fatty acid were incorporated in a 10 l volume Henschel mixer, and mixed for 15 minutes. To the ground calcium carbonate whose surface had been thus treated were added 30 g of anthraquinone and 30 g of benzophenone, and the mixture was again mixed in the Henschel mixer for another 10 minutes to produce a filler for degradable plastics.
EXAMPLE 17
To 20 kg of a slurry containing aluminum hydroxide with an average particle size of 8 microns having a solid concentration of 10% by weight were added 100 g of an aqueous 10% solution of a silane coupling agent, and the mixture was thoroughly mixed, followed by drying and pulverizing. The resulting aluminum hydroxide dried powder was incorporated in a 10 l volume Henschel mixer, and 50 g of anthraquinone was added, and the mixture was stirred and mixed for 15 minutes to produce a filler for degradable plastics.
EXAMPLE 18
To 20 kg of wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight was added a mixture in which 1 kg of corn starch and 40 g of anthraquinone were previously stirred into 600 g of a 10% solution of a sodium salt of fatty acid to carry out the surface treatment. Drying and pulverization gave a filler for degradable plastics.
EXAMPLE 19
1.2 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g and 0.75 kg of corn starch were incorporated in a 10 l volume Henschel mixer, and stirred and mixed for 20 minutes. To this were added 35 g of a sodium salt of fatty acid and 30 g of anthraquinone, and the mixture was again stirred for 10 minutes to carry out surface treatment, thereby producing a filler for degradable plastics.
EXAMPLE 20
To 20 kg of wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight was added 1 kg of corn starch followed by thoroughly stirring and mixing. To the slurry comprising colloidal calcium carbonate and corn starch was added a mixture in which 40 g of anthraquinone was previously stirred into 600 g of a 10% solution of a sodium salt of fatty acid to carry out the surface treatment. Drying and pulverization gave a filler for degradable plastics.
EXAMPLE 21
1.2 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g having 54 g of a sodium salt of fatty acid added thereto was incorporated in a 10 l volume Henschel mixer and mixed for 10 minutes to carry out surface treatment. Subsequently, 0.75 g of corn starch was added thereto, and mixed in the Henschel mixer for 20 minutes, after which 30 g of anthraquinone were added, and the mixture was again stirred and mixed in the Henschel mixer for 10 minutes, to produce a filler for degradable plastics.
EXAMPLE 22
1 kg of corn starch was incorporated in a 10 l volume Henschel mixer, stirred for 30 minutes, after which 20 g of a sodium salt of fatty acid was added, followed by stirring for another 10 minutes. The surface treated corn starch and DOP were thoroughly kneaded in a weight ratio of 3:5 to produce a plasticizer for degradable plastics containing the effective component.
COMPARATIVE EXAMPLE 1
A filler for plastics was produced by adding 600 g of a 10% sodium of a sodium salt of fatty acid for 20 kg of wet synthesized slurry of colloidal calcium carbonate with a specific surface area of 20 m 2 /g having a solid concentration of 8% by weight and by stirring them to carry out surface treatment, and pulverizing them.
COMPARATIVE EXAMPLE 2
2.4 kg of ground calcium carbonate with a specific surface area of 10 m 2 /g and 24 g of a sodium salt of fatty acid in a 10 l volume Henschel mixer were stirred and mixed for 20 minutes to carry out surface treatment. Drying and pulverization gave a filler for plastics.
COMPARATIVE EXAMPLE 3
Talc with a specific surface area of 13 m 2 /g was used as a filler for plastics as it was.
COMPARATIVE EXAMPLE 4
to 20 kg of slurry of aluminum hydroxide with an average particle size of 8 microns was added 100 g of an aqueous 10% solution of a silane coupling agent, followed by thoroughly stirring, drying, and pulverizing to produce an additive for plastics.
COMPARATIVE EXAMPLE 5
To 20 kg of an aqueous corn starch slurry having a solid concentration of 4% were added 300 g of a 10% strength solution of a sodium salt of fatty acid, and the mixture was stirred to carry out the surface treatment of the corn starch. Drying and pulverization gave an additive for degradable plastics.
COMPARATIVE EXAMPLE 6
A master batch was produced by kneading 2.5 parts by weight of anthraquinone with 100 parts by weight of polyethylene resin. This master batch was ready for use for degradable plastics.
REFERENTIAL EXAMPLE 1
100 parts by weight of PVC, 50 parts by weight of DOP, 3 parts by weight of tribasic lead sulfate, 3 parts by weight of Ca-Zn stabilizer, 3 parts by weight of epoxidized soybean oil, and 45 parts by weight of each filler produced in Examples 1-10, 18-21, and Comparative Examples 1-5 were mixed by means of mixing rolls and formed into a 1 mm thick plate. The plate was cut out into seven 10 cm square specimens in each case. These plates were embedded in soil 10 cm beneath the surface of the earth, and they were observed at intervals of 1 month, 3 months, 6 months, 9 months, 12 months, and 15 months. As a result, all the plates in which corn starch had been adsorbed via the surface treating agents in the respective Examples were almost completely degraded after 6 to 12 months, whereas in the plates from Comparative Example 5, though the degradation partially proceeded, the whole of degradation required over 15 months. With regards to the plates from Comparative Examples 1 to 4, no degradation sign was seen at all.
REFERENTIAL EXAMPLE 2
Resin pellets were prepared by kneading 100 parts by weight of polyethylene resin with 10 parts by weight of the fillers produced in Examples 11 to 21, and Comparative Examples 1 to 4, or with 10 parts by weight of the master batch of Comparative Example 6, respectively, and molded into 30 micron thick films by the T-die extrusion. These films were cut into 10 cm×20 cm specimens, and outdoor exposure tests were carried out for these specimens. As a result, the specimens from Examples 11 to 21 were degraded after 9 to 15 months, but in the specimens from Comparative Examples 1 to 4, no degradation signs were seen at all. With regard to the specimen from Comparative Example 6, while degradation was totally observed for 6 months, the specimen was not completely degraded, but portions which retained the shape was observed after 15 months.
REFERENTIAL EXAMPLE 3
100 parts by weight of PVC, 50 parts by weight of DOP, 3 parts by weight of tribase, 3 parts by weight of a Ca-Zn stabilizer, 3 parts by weight of epoxidized soybean oil, and 27.7 parts by weight of each filler produced in Comparative Examples 1-4 or 17.3 parts by weight of the additive produced in Comparative Example 5 were mixed by means of mixing rolls and formed into 1 mm thick plates. The soil embedding tests were conducted for these plate in the same manner as that in Referential Example 1. In each case, the plate was only partially degraded or parts of the pellets remained undegraded after 15 months.
REFERENTIAL EXAMPLE 4
10 parts by weight of fillers produced from Comparative Examples 1 to 4 respectively as well as 10 parts by weight of the masterbatch from Comparative Example 6 were kneaded with 90 parts by weight of polyethylene resin, to prepare pellets. The pellets were further molded into 30 micron thick films by the T-die extrusion. The exposure tests were conducted for these films as in Referential Example 2. As a result, in each case, part of the film remained undegraded after 15 months.
REFERENTIAL EXAMPLE 5
100 parts by weight of PVC, 80 parts by weight of the plasticizer containing the degradable effective component prepared in Example 22, 3 parts by weight of tribase, 3 parts by weight of a Ca-Zn stabilizer, 3 parts by weight of epoxylated soybean oil, and 15 parts by weight of the filler produced in Comparative Example 2 were mixed by means of mixing rolls and formed into a 1 mm thick plate. The soil embedding tests were conducted for the plate in the same manner as Referential Example 1. As a result, it was confirmed that almost the whole body was degraded for 9 months.
The results of Referential Examples 1 to 5 are shown in Table 1 all together.
In the table, the mark "⊚" represents "no change", "◯" represents "while opaque, change into yellow, and decrease in strength", "Δ" represents partial degradation and modification, and "×" represents total degradation and modification.
TABLE 1______________________________________Ref. Ex. Degradation conditions (months)Ex. Comp. Ex. 1 3 6 9 12 15______________________________________1 Ex. 1 ◯ ◯ Δ Δ X Ex. 2 ◯ Δ Δ X Ex. 3 ⊚ ◯ ◯ Δ X Ex. 4 ◯ ◯ Δ X Ex. 5 ◯ Δ X Ex. 6 ◯ ◯ Δ Δ X Ex. 7 ◯ ◯ Δ X Ex. 8 ◯ ◯ ◯ Δ X Ex. 9 ◯ ◯ Δ Δ X Ex. 10 ◯ ◯ Δ X Ex. 18 ◯ ◯ Δ X Ex. 19 ◯ Δ X Ex. 20 ◯ ◯ Δ Δ X Ex. 21 ◯ Δ Δ X Comp. 1 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 2 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 3 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 4 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 5 ◯ Δ Δ Δ Δ X2 Ex. 11 ◯ ◯ Δ Δ X Ex. 12 ◯ ◯ ◯ Δ Δ X Ex. 13 ⊚ ◯ Δ X Ex. 14 ◯ ◯ Δ Δ Δ X Ex. 15 ◯ ◯ Δ Δ X Ex. 16 ◯ ◯ Δ Δ X Ex. 17 ◯ ◯ Δ Δ X Ex. 18 ◯ ◯ ◯ Δ Δ X Ex. 19 ◯ ◯ Δ Δ X Ex. 20 ◯ ◯ Δ Δ Δ X Ex. 21 ◯ ◯ Δ Δ X Comp. 1 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 2 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 3 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 4 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Comp. 6 ◯ ◯ Δ Δ Δ Δ3 Comp. 1 ◯ ◯ Δ Δ Δ Δ Comp. 2 ◯ ◯ Δ Δ Δ Δ Comp. 3 ◯ ◯ ◯ Δ Δ Δ Comp. 4 ◯ ◯ Δ Δ Δ Δ4 Comp. 1 ◯ ◯ Δ Δ Δ Δ Comp. 2 ◯ ◯ ◯ Δ Δ Δ Comp. 3 ◯ ◯ ◯ Δ Δ Δ Comp. 4 ◯ ◯ Δ Δ Δ Δ5 Ex. 22 ◯ ◯ Δ X______________________________________
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In order to provide a filler for degradable plastics which can simplify the stages for producing a degradable plastic, give effective plastic-degradability, and stabilize the quality of the plastic article, the filler is used as a carrier substance and effective biodegradable and/or photodegradable components are adsorbed on the surfaces of the filler particles via a surface treating agent.
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PRIORITY
[0001] This application claims priority to an application entitled “NEW INPUT DEVICES FOR AUGMENTED REALITY APPLICATIONS” filed in the United States Patent and Trademark Office on May 31, 2001 and assigned Serial No. 60/294,850, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to augmented reality systems, and more particularly, to input devices and methods for user interaction with an augmented reality system.
[0004] 2. Description of the Related Art
[0005] Augmented reality is the technology in which a user's view of the real world is enhanced with additional information generated from a computer model, i.e., the virtual. The enhancements may include labels, 3D rendered models, or shading and illumination changes. Augmented reality allows a user to work with and examine the physical world, while receiving additional information about the objects in it. Some target application areas of augmented reality include computer-aided surgery, repair and maintenance, facilities modification and interior design.
[0006] In a typical augmented reality system, the view of a real scene is augmented by superimposing computer-generated graphics on this view such that the generated graphics are properly aligned with real-world objects as needed by the application. The graphics are generated from geometric models of both virtual objects and real objects in the environment. In order for the graphics and the real-world objects to align properly, the pose (i.e., position and orientation) and optical properties of the user and virtual cameras must be the same. The position and orientation of the real and virtual objects in some world coordinate system must also be known. The locations of the geometric models and virtual cameras within the augmented environment may be modified by moving its real counterpart. This is accomplished by tracking the location of the real objects and using this information to update the corresponding transformations of the geometric models within the virtual world. This tracking capability may also be used to manipulate purely virtual objects, ones with no real counterpart, and to locate real objects in the environment. Once these capabilities have been brought together, real objects and computer-generated graphics may be blended together, thus augmenting a dynamic real scene with information stored and processed on a computer.
[0007] Recent advances in both hardware and software have made it possible to build augmented reality (AR) systems that can run on regular desktop computers with off-the-shelf display and imaging devices. For example, the ARBrowser™ system, developed at Siemens Corporate Research, runs on a 400 MHz Pentium III machine. The system uses infrared video-based tracking technology, also developed at Siemens Corporate Research. This tracking technology considerably reduces the time required for tracking and pose estimation while maintaining the robustness and accuracy of the pose estimation. These advances allow the AR system to run on a regular computer without specialized display hardware at full frame rate, currently 30 frames per second (fps).
[0008] As the above-described advances in tracking speed and accuracy helped realize real-time augmentation, user interaction issues have become more visible. To fully realize the potential of AR systems, users need to interact with the systems and conventional methods, such as a keyboard and mouse, have proved to be very cumbersome. More advanced methods of interaction, i.e., speech driven methods, are hard to integrate with AR systems due to their inherent difficulties, such as “training” the speech driven system, and their large processing power requirements, which will hinder the running of the AR system resulting in lower frame rates and additional delays. Most augmented reality systems, currently being used and developed, are lacking easy-to-use, intuitive and effective means of interaction with the user.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to provide an interaction/input device for an augmented reality (AR) system.
[0010] It is another object of the present invention to provide an input device and method for use for an augmented reality (AR) system which is easy-to-use and intuitive for a user, thus enhancing the experience of the user with the system.
[0011] It is a further object of the present invention to provide an interaction device which requires minimal additional hardware and minimal additional processing power.
[0012] To achieve the above and other objects, a new interaction/input device for an augmented reality system is provided. By exploiting conventional tracking technology, the interaction/input device can be implemented with minimal additional hardware and minimal additional processing required by the augmented reality system. In an augmented reality system using infrared video-based tracking, the interaction/input device is employed by placing markers, e.g., small disks, at a predetermined location in a scene viewed by a user which are augmented to simulate physical buttons. These augmented markers, as viewed through the augmented reality system, can then be physically manipulated by the user. The user will put their fingers on one of these markers or disks, and in turn, the infrared video-based tracker will recognize this action and process it accordingly. The augmented reality system can also augment simulated menus in the user's view giving the user the necessary feedback for interaction.
[0013] According one aspect of the present invention, a system for augmenting a user's view of real-world objects with virtual objects to provide a composite augmented reality image is provided. The system including a display device for displaying the composite augmented reality image to the user; a video-based tracking system for locating real-world objects; a processor for determining the position and orientation of the user's view based on the location of the real-world objects and for projecting the virtual objects onto the display device; and an input device including at least one marker placed at a predetermined location in the real world, wherein the tracking system locates the input device and the processor determines its functionality based on its location.
[0014] According to another aspect of the present invention, in a system for augmenting a user's view of real-world objects with virtual objects to provide a composite augmented reality image, the system including a display device for displaying the composite augmented reality image to the user, a video-based tracking system for locating real-world objects, and a processor for determining the position and orientation of the user's view based on the location of the real-world objects and for projecting the virtual objects onto the display device, an input device is provided including at least one marker placed at a predetermined location in the real world, wherein the tracking system locates the input device and the processor determines its functionality based on its location.
[0015] According to a further aspect of the present invention, in a system for augmenting a user's view of real-world objects with virtual objects to provide a composite augmented reality image, the system including a display device for displaying the composite augmented reality image to the user, a video-based tracking system for locating real-world objects, and a processor for determining the position and orientation of the user's view based on the location of the real-world objects and for projecting the virtual objects onto the display device, a method for interacting with the system is provided. The method includes the steps of providing an input device including at least one marker placed at a predetermined location in the real world; capturing video of the real world by the video-based tracking system; analyzing the captured video to determine if the at least one marker is visible; if the at least one marker is visible, determining the real world location of the at least one marker; and loading the input device's functionality into the system to be available for the user to interact with the system. The method further includes the steps of determining if the at least one marker is not visible after entering an input mode; and if the at least one marker is not visible, performing a function associated with the at least one marker.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other objects, features, and advantages of the present invention will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:
[0017] [0017]FIG. 1A is a schematic diagram illustrating an augmented reality system with infrared video-based tracking in accordance with the present invention;
[0018] [0018]FIG. 1B is a perspective view of an infrared tracker camera with infrared illumination LEDs;
[0019] [0019]FIG. 2 is a flowchart illustrating a method of interacting with an augmented reality system employing an input device of the present invention; and
[0020] [0020]FIG. 3 illustrates several views of a user interacting with the augmented reality system in accordance with the present invention, where column 1 represents real-world views, column 2 represents views as seen from the infrared tracker camera and column 3 represents augmented views of a user.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Preferred embodiments of the present invention will be described hereinbelow with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the invention in unnecessary detail.
[0022] Generally, an augmented reality system includes a display device for presenting a user with an image of the real world augmented with virtual objects, a tracking system for locating real-world objects, and a processor, e.g., a computer, for determining the user's point of view and for projecting the virtual objects onto the display device in proper reference to the user's point of view.
[0023] Referring to FIG. 1A, an exemplary augmented reality (AR) system 10 to be used in conjunction with the present invention is illustrated. The AR system 10 includes a head-mounted display (HMD) 12 , an infrared video-based tracking system 14 and a processor 16 , here shown as a desktop computer. For the purposes of this illustration, the AR system 10 will be utilized in a specific workspace 18 which includes marker board 20 and an input device 22 of the present invention.
[0024] Referring to FIGS. 1A and 1B, the tracking system used in conjunction with marker board 20 determines the position and orientation of a user's head and subsequently a scene the user is viewing. Generally, the infrared video-based tracking system 14 includes a camera 24 with an infrared-filter lens 26 and a plurality of infrared illumination light-emitting diodes (LEDs) 28 mounted around the lens 24 ; a video capture board mounted in the processor 16 ; and a set of retroreflective markers, e.g., a circular disk or square tile. Video obtained from the camera 24 through the capture board is processed in the processor 16 to identify the images of the retroreflective markers. Because the video captured is filtered, the only visible items will be the ones corresponding to the retroreflective markers, i.e., items reflecting light in an infrared frequency. Since the location of the markers are known within a specific workspace, the processor can determine the pose of the user.
[0025] In the AR system of FIG. 1A, the marker board 20 is utilized for determining the pose of the user. The marker board 20 includes ten small retroreflective disks 30 surrounded by four thin retroreflective bands 32 . The exact configuration and location of the marker board 20 is stored in the processor so when the camera 24 of the tracking system 14 encounters the marker board 20 , the pose of the user can readily be determined. This pose estimation is used in turn for augmentation. The bands 32 surrounding the ten disks 30 robustify the tracking process and allow the addition of other retroreflective markers as input devices.
[0026] Once the marker board 20 is identified in the video as captured by camera 24 , the position of the input device 22 can be estimated in the video. The input device 22 is determined based on its physical location in the real world in relation to the physical location of the marker board 20 . Through the tracker and pose estimation as determined by the processor, the position of any world point in the user's view can be estimated. This means that the projection or position of the input device 22 in the user's view can be calculated, and thus, it can be determined if the input device is visible to the user. Once the input device becomes visible, the input device's functionality can be loaded and the AR system 10 can go into a menu/input mode and wait for the user's actions for some input events. The AR system 10 will determine if a user is interacting by determining if a marker of the input device 22 is visible or not. If the marker is not visible, e.g., by the action of the user covering the marker, the system will determine the marker is activated and perform an associated function.
[0027] It is to be understood the type and functionality of an input device of the present invention is determined by the processor based on the known specific locations of markers placed in the physical world in relation to the marker board. Therefore, once the position of the marker board 20 is estimated, any number of input devices can be realized by placing markers at known locations in relation to the marker board. For example, a single marker can be placed near the upper left hand corner of the marker board and can be augmented to represent an on/off button. Additionally, a 4×3 matrix of markers can be placed at a specific location in relation to the marker board to simulate a numerical keypad input device, like those used on a telephone. Furthermore, a combination of one or more input devices may be placed around the workspace at one time simulating different options to the users and making the AR system scalable.
[0028] An illustration of how a user interacts with an AR system employing an input device of the present invention will be described below in conjunction with FIGS. 2 and 3, where FIG. 2 is a flowchart illustrating a method of interacting with the augmented reality system employing an input device of the present invention and FIG. 3 illustrates several views of the user interacting with the augmented reality system in accordance with the present invention, where column 1 represents real world views, column 2 represents views as seen from the infrared tracker camera 24 and column 3 represents augmented views of the user and the rows of FIG. 3 represent different interactions of the user.
[0029] The first row in FIG. 3 shows the AR system entering a menu/input mode. The first view illustrates a real world view of the marker board 20 with input device 22 in close proximity at a specific, predetermined location in the real world (Step S 1 ). The second view of the first row is a view of the marker board 20 and input device 22 captured through the infrared-filtered camera 24 , wherein all retroreflective markers are visible (Step S 2 ). Through the use of the tracking system and processor, the AR system is able to determine the three markers 34 of the input device are outside the four bands of the marker board 20 and thus is the input device 22 and it is in the user's view (Step S 3 ). Once the pose of the user and input device is determined (Step S 4 ), the AR system will augment the user's view as in the third view of the first row. Here, as in Step S 5 , the three markers 34 are augmented with computer-generated graphics to simulate buttons or menus, e.g., the first markers reads “H” for help, the second marker reads “P” for previous page, and the third marker reads “N” for next page, and thus, the AR system enters the menu/input mode (Step S 6 ). Optionally, the AR system will overlay a graphic on the marker board 20 , such as a manual to assist the user in performing an operation to a piece of equipment in the user's view.
[0030] The second row of FIG. 3 shows the user choosing an action, i.e., requesting the next page of the manual. The first view of the second row shows the user's finger covering the third marker of the input device 22 . Camera 24 determines that the third marker is not visible, as shown in the second view of the second row and in Step S 7 , and the AR system realizes the user has prompted the system to go to the next page. The third view of the second row illustrates the user interacting with the system as seen through the HMD 12 , where the user initiates an action by “pressing” the “N” button and the system performs the associated function by going to Page 2 of the manual (Step S 8 ).
[0031] The third row of FIG. 3 illustrates the that the input device 22 can be augmented with menus in addition to buttons. In the first view of the third row, the user places their finger on the first marker which corresponds to the “H” or Help button. Once the AR system determines the user has requested help, the AR system will augment the user's view by inserting a graphic help menu with several help options, as shown in the third view of the third row. In addition, up and down arrows will be placed above the second and third markers during the help mode to assist the user in selecting the help option desired. It is to be understood that the up and down arrows are only augmented in the user's view during the help mode. It is also to be understood that whenever a single marker is activated the remaining two markers can be augmented to reveal other options of the activated marker.
[0032] New input devices and interaction methods for augmented reality applications that exploit the recent advances in augmented reality technologies have been described. In particular, for the augmented reality systems that use an infrared video-based tracking system, the interaction/input devices and methods of the present invention provide intuitive, easy-to-use means of interacting with the augmented reality system. The system gives the user visual feedback in forms of augmentation, e.g., menus, to facilitate the interaction.
[0033] The input devices of the present invention do not put any additional burden on the running or processing of the augmented reality application since the AR system is already determining locations of markers for tracking purposes. The tracking system intelligently can decide if the user is in the input/interaction mode by determining if the user is looking at the various menu markers in the scene. Furthermore, use of visual feedback assists the user and enhances his/her experience with the augmented reality system greatly.
[0034] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. For example, the input device can be employed in various types of AR systems, such as optical see-through or video see-through systems. Additionally, the input device of the present invention can be used in conjunction with different types of display devices, e.g., a computer monitor, video-capable mobile phone, personal digital assistant (PDA), etc.
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A new interaction/input device for an augmented reality system is provided. In an augmented reality system using infrared video-based tracking, the interaction/input device is employed by placing markers, e.g., small disks, at a predetermined location in a scene viewed by a user which are augmented to simulate physical buttons. These augmented markers, as viewed through the augmented reality system, can then be physically manipulated by the user. The user will put their fingers on one of these markers, and in turn, the infrared video-based tracker will recognize this action and process it accordingly. The augmented reality system can also augment simulated menus in the user's view giving the user the necessary feedback for interaction. By exploiting conventional tracking technology, the interaction/input device can be implemented with minimal additional hardware and minimal additional processing required by the augmented reality system.
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FIELD OF THE INVENTION
This invention relates to refrigeration systems such as air conditioning systems, and more specifically, to an integral receiver/condenser useful in such systems.
BACKGROUND OF THE INVENTION
Vapor compression refrigeration systems conventionally employ a condenser which receives a refrigerant in the vapor phase under relatively high pressure from a compressor. The condenser is operative to condense the refrigerant vapor to the liquid phase for ultimate transmittal to an evaporator whereat the refrigerant evaporates. Heat from the ambient is rejected to the refrigerant where it is absorbed as the latent heat of vaporization as the refrigerant evaporates. The now vaporized refrigerant is then directed to the compressor to be recycled through the system.
Conventionally such systems include a so-called receiver which is intended to receive liquid refrigerant from the condenser before it is transmitted to the evaporator. The primary purpose of the receiver is to assure that all refrigerant passed to an expansion device upstream of the evaporator is in the liquid phase. This means that the refrigerant quality is low and its enthalpy is also low to increase the evaporator's ability to absorb heat as the refrigerant evaporates. In this connection, the receiver acts as a reservoir for excess liquid refrigerant to assure that only liquid is fed to the expansion device in spite of system changes typically caused by the operation of the compressor. For example, in an automotive air conditioning system, the compressor is frequently stopped and started. Furthermore, when the engine to which the compressor is typically mechanically coupled is accelerating, compressor speed may also change, causing a change in the pressure at its inlet which in turn affects the flow rate of refrigerant in the system.
In addition, receivers may also be provided with a means for filtering the refrigerant as well as for drying the refrigerant to assure its purity, thereby avoiding inefficient operation.
It is desirable to integrate the receiver with the condenser in many instances. For example, in so-called parallel flow condensers of the multipass type, integration of the receiver with the condenser assures that only liquid refrigerant will be fed to the last pass of the condenser which then acts solely as a subcooling pass. When such is accomplished, the increased subcooling further lowers the refrigerant quality while reducing the enthalpy of the refrigerant delivered to the evaporator to achieve the efficiencies mentioned earlier. Moreover, integration of the receiver with the condenser eliminates the need for a separate receiver/dryer elsewhere in the system and has the ability to reduce the total cost of the system as well as the quantity of refrigerant that must be charged into the system.
In this latter respect, it is well known that certain refrigerants are not environmentally friendly. For example, CFC 12 is thought to degrade the protection ozone layer surrounding the earth. Other refrigerants such as HFC 134a, while less damaging of the ozone layer, are thought to contribute to the so-called greenhouse effect which may be responsible for global warming.
Because in automotive air conditioning systems, the compressor is driven by the vehicle engine, it cannot be hermetically sealed as in residential or commercial air conditioning units. As a consequence, there is the potential for escape of the refrigerant through compressor seals with the resulting deleterious effects on the environment. Thus, refrigerant charge volume is of substantial concern.
In U.S. Pat. No. 5,546,761 issued Aug. 20, 1996 to Matsuo et al, there is disclosed an integrated receiver/condenser. One difficulty with the type of system disclosed in that patent is that turbulence may be induced within the receiver. The turbulence may be induced by the incoming refrigerant which typically will be a mixture of vapor and liquid phase refrigerant. Another source of turbulence, particularly when the receiver/condenser is employed in a vehicular air conditioning system, is vehicular speed changes. As the vehicle accelerates or decelerates, liquid refrigerant within the receiver may undergo substantial shifts in its position in relation to the receiver outlet.
When such turbulence is present, it is possible for refrigerant as a mixture of liquid and vapor to reach the receiver outlet. When that occurs, the last pass of the condenser is no longer exclusively a subcooling pass. Rather, it will not only act to subcool that refrigerant that is in the liquid phase, but it will act to condense that refrigerant which is in the vapor phase. As a consequence, the optimal degree of subcooling cannot be achieved and system operation suffers.
The present invention is directed to overcoming one or more of the above problems.
SUMMARY OF THE INVENTION
It is a principal object of the invention to provide a new and improved integrated receiver/condenser for use in a refrigeration system. Typically, but not always, the improved receiver/condenser will be employed in an automotive air conditioning system.
According to the invention, a condenser for a refrigerant is provided and includes two spaced, non-horizontal, elongated headers. Tube slots are in the facing sides of the headers with the tube slots in one header being generally aligned with the tube slots in the other head. A plurality of tubes extend between the headers with their ends in corresponding ones of the slots to establish a plurality of hydraulically parallel flow paths between the headers. At least one partition is located at each of the headers for causing refrigerant to make at least two passes, including a first pass and a last pass, through the condenser. A refrigerant inlet is located in one of the headers and communicates with the first pass. A refrigerant outlet is also located in one of the headers and communicates with the last pass. An elongated receiver is mounted on one of the headers and has a longitudinal axis. The receiver has a lower liquid outlet connected to an upstream side of the last pass and an upper inlet connected to a downstream side of the first pass. The upper inlet and lower outlet, at their connections to the header on which the receiver is mounted, are separated by one of the partitions.
According to one facet of the invention, the upper inlet is canted with respect to the longitudinal axis of the receiver to induce a vortex flow of refrigerant in the receiver, while according to another embodiment of the invention, the upper inlet is also canted to one side of the longitudinal axis. In a highly preferred embodiment of the invention, the upper inlet is canted upwardly toward the longitudinal axis and is also canted to one side of the longitudinal axis.
As a result of this construction, a vortex flow of refrigerant occurs in the receiver which tends to cause a separation of the higher density liquid refrigerant from the lower density vaporous refrigerant. Gravity then causes the dense liquid refrigerant to move downwardly toward the lower outlet.
According to another embodiment of the invention, the condenser is provided with elongated headers, tube slots, a plurality of tubes, at least one partition in each header, a refrigerant inlet, a refrigerant outlet and an elongated receiver having an upper inlet and a lower outlet as before. In this embodiment of the invention, a perforate baffle is located within the receiver at a location between the upper inlet and the lower outlet and serves to maintain separation of liquid refrigerant from refrigerant in the vapor phase.
In one embodiment of the invention, a detachable cap is provided for the receiver so as to allow the installation of a filter and/or conventional drying material within the receiver.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of an integrated receiver/condenser made according to the invention;
FIG. 2 is a front elevation of the receiver/condenser;
FIG. 3 is a plan view of the receiver/condenser;
FIG. 4 is a side elevational view of the receiver/condenser;
FIG. 5 is a somewhat schematic elevational view of the receiver inlet;
FIG. 6 is a somewhat schematic plan view of the receiver inlet;
FIG. 7 illustrates one means for mounting the receiver on a condenser;
FIG. 8 illustrates another means of mounting the receiver on a condenser;
FIG. 9 illustrates still another means for mounting the receiver on a condenser and for directing incoming refrigerant in a desired path;
FIG. 10 is a perspective view of still another means for mounting the receiver on a condenser;
FIG. 11 is a perspective view of a mounting means similar to that shown in FIG. 10 but additional including means for directing the incoming refrigerant in a desired path;
FIG. 12 illustrates a baffle that may be employed in the receiver;
FIG. 13 illustrates another form of the baffle;
FIG. 14 illustrates still another form of a baffle;
FIG. 15 is a sectional view of still another form of a baffle;
FIG. 16 is a fragmentary perspective of refrigerant flow as it enters the receiver; and
FIG. 17 is a schematic illustrating a variety of positions in which the receiver may be mounted on the condenser.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary embodiments of an integrated receiver/condenser are illustrated in the drawings and with reference to FIGS. 1-4 inclusive, are seen to include a condenser, generally designated 20 and a receiver, generally designated 22 mounted thereon in substantial abutting relation therewith. The condenser includes tubular, elongated, vertically oriented headers 24. Each header 24 on its side facing the other includes a plurality of tube slots 26 which are aligned with the tube slots 26 in the opposite header. A plurality of multiport flattened tubes 28 extend between the headers 24 and have their ends 30 received in sealed relation in corresponding ones of the slots 26. In the usual case, the components will be made of aluminum and are bonded together as by brazing.
Serpentine fins 34, shown only schematically in the figures, extend between adjacent ones of the tubes 28 and, at the sides of the condenser 20, side plates 36.
The ends of the tubular headers 24 are sealed as by end plugs 40 which are typically brazed in place.
The embodiment illustrated is intended to be a two pass condenser and to this end, near its lower end, includes a double slot 42 which receives an imperforate partition or baffle 44. In a preferred embodiment, the slot 42 and baffle 44 are formed generally in the fashion shown in FIGS. 1-6 of commonly assigned U.S. Pat. No. 4,936,381 issued on Jun. 26, 1990 to Alley, the entire disclosure of which is herein incorporated by reference.
The opposite header 24 includes a similar slot 46 which receives a baffle 48 which is also generally the same as the baffle 44. In the embodiment illustrated, the slots 42 and 46 are at the same location on their respective headers.
The rightmost header 24 includes an inlet opening 50 to which an inlet fixture 52 is brazed. The fixture 52 serves as the point of connection of the condenser into the system and it will be seen that the same is above the baffle 44.
Below the baffle, the rightmost header 24 includes a second opening 54 which in turn receives an outlet fixture 56 which serves as the outlet from the receiver/condenser to the system.
If desired, a mounting fixture 58 may also be brazed to the rightmost header 24. A similar fixture 60 may be brazed to the leftmost header 24.
The receiver 22 is cylindrical and of generally the same length as the headers 24. It is of a larger diameter so as to provide sufficient volume to store the necessary amount of refrigerant as the system requires.
As its upper end, the receiver 22 is closed by a threaded cap 62. The cap 62 is thus removable and serves as a means whereby, after assembly of the receiver/condenser, a filter and/or a conventional drying material may be introduced into the receiver 22.
Near its lower end, the receiver 22 includes an upper refrigerant inlet 64 and a lower refrigerant outlet 66. As illustrated in FIG. 1, the upper inlet 64 and lower outlet 66 are in the form of nipples which may be sealingly received in aligned openings in the leftmost header 24. The arrangement is such that the upper inlet 64 will be above the partition 48 while the lower outlet 66 will be below the partition 48.
It will thus be appreciated that a two pass condenser is defined. Specifically, refrigerant may enter through the fixture 52 and be distributed by the header 24 to the tube ends 30 that are above the partition 44 to flow to the leftmost header. Once the refrigerant enters the leftmost header 24, it may exit the same via the upper inlet 64 to the receiver 22. After the mixture of liquid and vapor phase refrigerant is separated within the receiver 22, liquid refrigerant may exit the receiver 22 via the lower outlet to ultimately be returned to the rightmost header 24 via those tubes 28 that are located below the partitions 44 and 48. During this pass, the liquid will be subcooled as desired and ultimately will be returned to the system via the fitting 56. Of course, it should be understood that the invention is not limited to any specific number of passes although it will always be employed in a condenser having at least two passes.
Returning to the receiver 22, between the upper inlet 64 and the lower outlet 66, the same includes a baffle receiving slot 70 for purposes to be seen.
Turning now to FIGS. 5 and 6, the orientation of the upper inlet 64 and the receiver 22 will be described. A cylindrical tube defining the receiver 22 is shown at 72, albeit somewhat schematically and its longitudinal axis is designated 74. Referring to FIG. 5 specifically, it will be seen that the inlet 64 is canted at an acute angle α with respect to the longitudinal axis 74. In particular, the inlet 64 is canted upwardly with respect to the axis 74.
As seen in FIG. 6, the inlet 64 may be alternatively or additively canted to one side of the longitudinal axis 64 by an angle β. As will be seen in greater detail hereinafter, this configuration causes the generation of a vortex of the incoming mixed phase refrigerant. The vortex is much the same as that found in a cyclone separator with the higher density liquid refrigerant being centrifugally flung against the interior wall of the receiver 22 to drain under the influence of gravity toward the lower outlet 66. The lesser density vaporous refrigerant remains in the receiver 22 until it condenses as a result of heat exchange though the receiver wall or as a result of contact with incoming liquid refrigerant that may be partially subcooled.
FIG. 7 illustrates one form of a nipple that may be used in making one or both of the upper inlet 64 and lower outlet 66. Specifically, the same is no more than a short section of tube 80 with a peripheral rib 82 about its center. The rib 82 prevents either end of the tube 80 from extending too far into either the leftmost header 24 or the receiver 22.
As an alternative to the use of the tube, conventional T-drilling may be employed as illustrated in FIG. 8 to form a flange 84 extending outwardly from the header 24 to peripherally embrace a somewhat smaller flange 86 in the wall of the receiver 22. The flanges 84 and 86 are united and sealed during the brazing operation.
FIG. 9 illustrates still another form of means by which the receiver 22 may be mounted on the condenser 20. Like FIG. 7, a short section of tube 90 is employed and the same is provided with a generally central, peripheral rib 92 having the same function as the rib 82. However, on that end 94 of the tube 90 that is to enter the receiver 22, an upturned lip or projection 95 is provided. By suitably orienting the tube 90 at the time of initial assembly, the lip 95 may be made to direct incoming mixed refrigerant at the angle α or at the angle β, or both. Alternatively, when the using the tube 80, the same may simply be skewed somewhat to provide either or both of the angles α and β by appropriately directioning the bores in the receiver 22 and the header 24 in which the same is received.
FIG. 10 shows still another form of a means by which the receiver 22 may be mounted on the condenser 20. A saddle-like mounting block 96 is employed and the same includes first and second semicylindrical recesses 97 and 98. The recess 97 is of the same diameter as the outside diameter of the header 24 while the recess 98 is of the same diameter as the outside diameter of the receiver 22. Interconnecting recesses 98 and 97 is a bore 99. In this embodiment of the invention, the tube 80 may done away with entirely with the ends of the bore 99 respectively aligned with the openings in the receiver 22 and the header 24 that are normally occupied by the tube 80. When the assembly is brazed together, braze metal will provide a seal around the ends of the bore 99 to make the junction fluid tight.
FIG. 11 shows still another form of a means by which the receiver 22 may be mounted on the condenser. Again, a saddle like mounting block 100 is employed and again, the same has oppositely directed recesses 101 and 102 which are semicylindrical and which are dimensioned just as the recesses 97 and 98. A bore 103 connects the recesses 101 and 102 just as the bore 99. In this embodiment, however, a short length of tube 104 is inserted in the end of the bore 103 opening to the recess 102. The tube 104 is sized so as to enter the opening in the receiver 22 that would otherwise be occupied by the tube 80.
Whereas the bore 99 is generally formed to intersect the longitudinal axis 74 of the receiver 22 at mutually perpendicular right angles, that may or may not be true of the bore 103.
For example, the bore 103 may be angled such that the tube 104 will enter the receiver 22 at an angle canted with respect to the longitudinal axis 74, the angle being either the angle α (FIG. 5) or the angle β (FIG. 6) or both to provide a desired vortex action as explained previously.
Returning to FIG. 1, it will be recalled that a slot 70 is provided in the receiver 22. In fact, the slot 70 is a double slot much like that shown in the previously identified Alley patent and is intended to receive a baffle configured generally in the form illustrated by Alley.
FIG. 12 illustrates a preferred form of the baffle and the same is seen to include a generally circular plate 106 with opposed, L-shaped notches 108 in its opposite sides. Whereas the baffle disclosed by Alley spaces the notches 108 a distance approximately equal to the inside diameter of the tube, in the baffle illustrated in FIG. 12, the long sides 110 of the notches 108 are spaced a distance less than the internal diameter of the receiver 22 so as to leave a pair of elongated openings 112 between the inner tube wall 114 of the receiver 22 and the long sides 110. The openings 112 serve as drain holes whereby liquid refrigerant may drain from that part of the receiver 24 above the baffle 106 toward the lower outlet 66 while the main body of the baffle plate 106 serves to isolate any turbulence occurring in the vicinity of the upper inlet 64 from the liquid adjacent the lower outlet 66.
FIG. 13 illustrates another form of the baffle as being made of a generally circular plate 115 having two L-shaped notches 116 cut in the sides thereof for the purposes mentioned by Alley. The plate 115 is provided with a plurality of elongated slots 117 near its periphery. The slots 117 are arcuate. Just as in the FIG. 12 embodiment, they serve as drain holes whereby liquid refrigerant may drain from that part of the receiver 24 above the baffle 115 toward the lower outlet 66 while the main body of the baffle plate 115 serves to isolate any turbulence occurring in the vicinity of the upper inlet 64 from the liquid adjacent the lower outlet 66.
FIG. 14 illustrates another form of a baffle which again includes a generally circular plate 118 provided with L-shaped cutouts 119 in opposite sides for the same purpose as disclosed by Alley. A generally central, circular aperture 1 20 is provided to serve the same functions as the slots 117.
Still another form of the baffle received in the slot 70 is illustrated in FIG. 15. Again, a plate 121 is employed and is provided with L-shaped notches 122 like those illustrated at 116 and 119. In the center of the plate 121, a tab 124 is displaced from the body of the plate 121 to leave an opening 126. The opening 126 serves as a drain hole much like the slots 117 or the aperture 120. The tab 124 may be oriented to be in the path of the incoming stream, that is, in the discharge path of, for example, the opening defined by the flanges 84,86 or the end of the tube 80 within the receiver to provide a desired deflection of the incoming mixed refrigerant stream at the angles α or β or both.
Reference is made to FIG. 16. In this embodiment, the tube 80 is employed as the upper inlet 64 and as can be seen, is canted in the manner mentioned in connection with FIGS. 5 and 6. The vortex of the incoming refrigerant is illustrated by an upwardly spiraling arrow 130 which illustrates the path taken by the liquid refrigerant. Arrows 132 and dots 134 illustrate the path taken by the gaseous refrigerant.
As can be readily appreciated, the baffle 100 acts to effectively segregate any turbulence as a result of the incoming stream or that may be generated by movement of the receiver 22, as when in a vehicle, from the lower outlet 66.
In some instances, the baffle 100 may be omitted while in others, the baffle 100 may be retained and the canting of the upper inlet 64 omitted.
Still another advantage of the construction of the invention is illustrated in FIG. 17. It will be appreciated that by appropriately locating the holes or openings for the connection of the receiver 22 to the header 24, the receiver 22 may be located in any of a plurality of positions spaced as many as 180° about the header 24 as illustrated by the positions shown at 22, 22' or 22". Thus, depending upon the available space at a given installation, the position of the receiver with respect to the body of the condenser may be varied substantially to accommodate special spatial requirements.
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Loss of efficiency as a result of inadequate subcooling caused by the entry of gaseous refrigerant into the subcooling stage of a condenser (20) from a receiver (22) is avoided in a construction wherein an upper inlet (64) to the receiver (22) is canted at an angle (α,β) with respect to the longitudinal axis (74) of the receiver to induce a vortex flow (130) of refrigerant in the receiver (22). A baffle (106,115,118,121) may advantageously be located between the upper inlet (64) and a lower outlet (66) of the receiver (22) to isolate turbulence within the receiver (22) from the lower outlet (66).
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This is a continuation-in-part of application Ser. No. 349,300 filed Apr. 9, 1973 and now abandoned.
BACKGROUND OF THE INVENTION
The invention relates generally to an anti-burglary device and more particularly to an anti-burglary device which discharges a chemical irritant such as tear gas from a pressurized container, one type of which is an aerosol container, into a protected area upon activation by an unauthorized person, causing the protected area to be flooded with a chemical irritant and forcing evacuation of the protected area by the intruder; but the invention is not limited to the use of the aerosol type container.
Chemical weapons have been known in the art for many years. One type of chemical weapon is the conventional tear gas grenade in which the firing member is generally triggered manually and said grenade is manually hurled at a target area, causing the target area to be flooded with the chemical irritant.
In another type of chemical weapon, the chemical irritant is stored under pressure in an aerosol type container. The firing member is again generally triggered manually and the chemical irritant in the form of a spray is manually directed at a target.
A third type of chemical anti-burglary device discharges an explosive tear gas shell into the area but this type is both dangerous and very limited as to the amount of tear gas which is discharged into the area to be protected.
Thus what is needed in an anti-burglary device in the form of a chemical dispenser which can be discharged by relatively small amount of mechanical force or which can be triggered by an electrical signal from remote contacts or other type sensors, even though the chemical weapon employs a relatively heavy spring for actuating the discharging means with sufficient force to release the chemical from the pressurized container but is positively secured against accidental release until triggered by an intruder and which will then release a sufficient volume of chemical into the protected area to force evacuation by the intruder.
SUMMARY OF THE INVENTION
The principle object of the present invention is to provide an anti-burglary device of the chemical dispensing type which may be triggered either directly by a small amount of mechanical force or remotely from electrical sensors and a power source or by both electrical and mechanical means and yet is positively secured against accidental release.
A further object of the invention is to provide an anti-burglaary device of the chemical weapon type which is readily triggered by a cord connecting the device to a window, door or object which might be moved by an intruder, or by an intruder entering an unauthorized area.
Another object of the invention is to provide an improved means of discharging the chemical into the protected area in a minimum amount of time in order to force the intruder from the protected area and to prevent the intruder from re-entering the protected area for a reasonable amount of time.
A further object of the invention is to provide an anti-burglary device which can easly be activated yet when deactivated is virtually impossible for a small child to activate or virtually impossible to accidentally discharge.
A further object of the invention is to provide an anti-burglary device having means for reloading the device and resetting the weapon in its cocked position after the device has been triggered.
Another object of the present invention is to provide a directable emission of the chemical, such as by means of rotatably adjustable dispersing head, so that the invention might be located in a concealed place yet direct the chemical into the protected area.
According to the principle aspect of the present invention there is provided an improved means for releasably retaining a spring biased pressurized chemical container slidably mounted in a cavity containing a discharging means and passageway leading to a rotatably adjustable dispensing head with nozzle. A cord, cable, wire or the like connects the trigger element to a window, door or other object which might be moved by an unauthorized person entering a room or building, or across a walkway or other area from which it is desired to restrict unauthorized persons. The trigger element retains the slideably mounted spirng biased pressurized chemical container in shouldered engagement, thereby retaining the pressurized chemical container in its cocked position and requiring positive force for release. When the door or window associated with the device is opened by an unauthorized person or when the person enters the restricted area, the cord connected to the trigger element moves the latter from shouldered engagement, thereby releasing the slideably mounted pressurized chemical container and permitting the container to be thrust toward the passageway by the force of the spring associated with the said container and causing the said container to discharge the chemical through the passageway and rotatable dispensing head into the protected area.
Since the trigger element, which serves to retain the pressurized chemical container in its cocked position is slideably mounted; a relatively small amount of force is required to move the trigger element from shouldered engagement with the said container and discharge the container, even though a relatively strong spring is employed for activating the discharging means. As a consequence, the cord connected to the trigger element will not break in triggering the chemical weapon. The resistance to movement of the cord due to its connection to the trigger element is sufficiently low so as not to be observed by an intruder. Nevertheless, the trigger element serves to retain the container safely in its cocked position against accidental release.
Since the trigger element is slideably supported in a narrow slot and provided with a narrow opening to insert a cord with a narrow specially haped loop on it; it is virtually impossible for a small child to activate the device when the cord is removed. In addition, a safety pin is provided as an additional safegaurd against accidental discharge.
Alternatively, an electromechanical actuator may be used in releasable engagement with a self-camming trigger element such that the electromechanical actuator latch lever retains the trigger element which is shaped such as to be self-camming from the pressure exerted on the trigger element by the spring biased pressurized chemical container. When a contact or other electrical sensing element is operated by an unauthorized person entering a protected area, the solenoid is energized, operation the solenoid latch lever, freeing the self-caming trigger element which causes the spring biased container to activate the discharging means, discharging the chemical through the passageway and rotatable dispensing head into the protected area.
The self-camming trigger element is shaped so as to exert only a small amount of force on the solenoid latch lever and a relatively small low power solenoid may be used to allow operation from batteries in locations remote from ordinary power lines. The solenoid latch lever nevertheless can retain the trigger element safely against accidental release from mechanical or electrical transient shock.
An additional method of retaining the trigger element is to replace the solenoid latch with a fusable link such that the trigger element is held in position until a voltage is passed through the fusable link, thus releasing the container and discharging the irritant.
The anti-burglary device of the chemical weapon type of the present invention may be utilized in homes, factories, farms office buildings by connecting the cord attached to the trigger element of the device to doors, windows, machinery, appliances, etc., and may be used in connection with vehicles such as boats, trucks, airplanes, etc. The device may also be employed for any other application wherein it is desired to prevent unauthorized persons from moving certain objects. The device may further be utilized to prevent unauthorized persons from entering restricted areas by extending the cord connected to the trigger element a short distance above the ground across a walkway, entrance way, etc., into the area so that the intruder will strike the cord and thereby activate the mechanism and discharge the chemical irritant.
Alternatively any of the foregoing embodiments of the present invention may be accomplished by means of electrical contacts or other sensors similarly positioned and operated from ordinary power lines or from batteries internal or external from the items or area to be protected.
Once actuated, the spray cannot be turned off by the intruder and the entire amount of pressurized chemical irritant will be discharged into the protected area making it impossible for the intruder to remain in the protected area without having protective equipment.
Other objects, aspects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an elevational view of a wall of a room having one embodiment of the chemical dispensing anti-burglar device of the present invention secured to the wall and connected by means of a cord to the sash of a window in the wall.
FIG. 2 is an elevational similar to FIG. 1, but showing the window open and showing the device discharging.
FIG. 3 is a front elevational view of the chemical dispensing anti-burglar device.
FIG. 4 is a vertical section taken along line B--B of FIG. 3 showing the pressurized container in its cocked position displaced from the open entry section of fluid passageway.
FIG. 5 is a vertical section taken along line B--B of FIG. 3 similar to FIG. 4 but showing the container in its release position after the device has been triggered.
FIG. 6 is a partial horizontal section taken along line A--A of FIG. 3 with the trigger element cocked and locked by the safety pin.
FIG. 7 is a veritcal section similar to FIG. 4 but showing a second embodiment of the anti-burglar device containing a pressurized container of the aerosol type but with a recessed valve.
FIG. 8 is a vertical section similar to FIG. 4 but showing a third embodiment of the anti-burglar device containing a pressurized container of the type with a pierceable seal and a means for piercing the seal.
FIG. 9 is a front elevational view of the chemical dispensing device showing an alternate type construction and a slidable trigger.
FIG. 10 is a vertical section taken along line C--C of FIG. 9 showing the device in its cocked position.
FIG. 11 is a front elevational view similar to FIG. 3 but showing a fifth embodiment of the chemical dispensing anti-burglary device containing a pressurized container of the aerosol type with a projecting cap.
FIG. 12 is a vertical section taken along line D--D of FIG. 11 showing the pressurized container in a cocked position.
FIG. 13 is a horizontal section taken along line D--D of FIG. 11 but showing the pressurized container in its released position after the device has been triggered.
FIG. 14 is an elevational view of a wall of a room having the sixth embodiment of the chemical dispensing anti-burglary device of the present invention secured to a wall and electrically connected to a switch at the window.
FIG. 15 is an elevational view similar to FIG. 14 but showing the window open and showing the device discharging.
FIG. 16 is a front elevational view similar to FIG. 3 but showing a sixth embodiment of the anti-burglar device containing a pressurized container of the aerosol type with a projecting spout for electromechanical operation.
FIG. 17 is a vertical section taken along line E--E of FIG. 16 showing the pressurized container in a cocked position.
FIG. 18 is a vertical section taken along line E--E of FIG. 16 similar to FIG. 17 but showing the pressurized container in its released position after the device has been triggered.
FIG. 19 is a horizontal section taken along line F--F of FIG. 16 with the trigger element cocked and locked by the safety pin;
FIG. 20 is a partial horizontal sectional taken along line G--G of FIG. 17 showing the electromechanical actuator of the anti-burglar device wherein the trigger element is electromechanically controlled.
FIG. 21 is a partial horizontal sectional taken along line H--H of FIG. 18 showing the anti-burglary device in its discharging position.
FIG. 22 is a vertical section similar to FIG. 17 wherein the trigger element is held in shouldered engagement with the pressurized container by a movable object thereby retaining the trigger element in its actuation position.
FIG. 23 is a front elevational view similar to FIG. 3 but showing a seventh embodiment of the anti-burglar device containing a pressurized container of the aerosol type with a projecting spout wherein the trigger element is held in the actuation position with a fusible link.
FIG. 24 is a vertical section taken along line L--L of FIG. 23 showing the pressurized container in its cocked position.
FIG. 25 is a horizontal section taken along line M--M of FIG. 24 showing the fusible link holding the trigger element in its actuation position.
FIG. 26 is a front elevational view similar to FIG. 3 but showing an eighth embodiment of the anti-burglary device containing a pressurized container of the aerosol type with a projecting spout for positive release by electromechanical operation.
FIG. 27 is a vertical section taken along line N--N of FIG. 26 showing the pressurized container in a cocked position.
FIG. 28 is a horizontal section taken along line P--P of FIG. 27 showing the electromechanical actuator in its actuation position.
FIG. 29 is a horizontal section aken along line P--P of FIG. 27 similar to FIG. 28 but showing the electromechanical actuator in its release position.
FIG. 30 is a horizontal view showing the shape of the loop for insertion over the trigger element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in detail, wherein like reference characters designate like parts throughout the various views, there is shown in FIGS. 1-6, one form of the chemical dispensing anti-burglar device, called device hereafter, of the chemical weapon type according to the present invention, generally designated 6. The device 6 is secured to a wall 2 and connected by means of a cord 5 to a window sash 3 in the wall 2 so that upon opening of the window sash 3 by a burglar or intruder, the device 6 will be actuated to discharge a chemical 13 such as tear gas into the restricted area. The device 6 whose front is shown in FIG. 3 comprises of a pressurized chemical container 31, called pressurized container hereafter, mounted in a body member 11 comprising of a left body half 21 and a right body half 22. The body halves 21 and 22 when assembled provide three flat sides, other than the front, for mounting the device 6 to the wall 2 adjacent to the window frame 1 or elsewhere, as may be convenient, and the cord 5 connected from the device 6 to a wide variety of objects in many ways.
The coaxial cylindrical bores 32 and 39, as shown in FIGS. 4 and 5, are formed when the symetrically opposite body halves 21 and 22 are joined together as shown in FIGS. 3 and 6. The cylindrical bore generally designated 32 slideably mounts the pressurized container 31. The pressurized container 31 of which one type is sold by Defense Products Manufacturing Corporation, 1628 South Hanley Rd. St. Louis, Mo. identified as their "Paralyzer" and another type is sold by Penquin Industries, Inc., Parkesburg, Pa. identified as their "10-4 Chemical Billy" but the invention is not limited to the use of these containers. The pressurized container 31 comprises of a spring urged projecting dispensing spout 35 which when depressed discharges a chemical 13 through the center of the projecting dispensing spout 35.
The cylindrical bore generally designated 39 is coaxial with cylindrical bore 32 and provides a means for confining the spring 33. Spring 33 is mounted to urge the pressurized container 31 in the direction 12.
Now referring to FIGS. 4 and 5; the body member 11 comprising of the body halves 21 and 22 forms a fluid passageway 41 having an entry section 36 for engaging with the projecting dispensing spout 35 of container 31 on one end and a coaxial hole 42 for mounting a rotatable dispensing head 14 on the other end. The fluid passageway 41 and the dispensing head 14 provide a means for the chemical 13 to be discharged into and directed from when the projecting dispensing spout 35 of the container 31 is forced into the entry section 36 by the spring 33 acting to move the slideably mounted container 31 in the direction of arrow 12. The funnel shape of the entry section 36 engages the projecting dispensing spout 35, which is made of a relatively soft material and therefore provides an adequate seal at the entry section 36 to retain fluid flow in the passageway 41 at pressures normally used in the pressurized container 31.
The container 31 in the position illustrated in FIG. 4 is in its cocked position where the spring 33 is compressed and the spout 35 is coaxial but not seated into the entry section 36. The container 31 is releasably restrained in a cocked position by a trigger element 7. The trigger element 7 is generally a flat member and includes a shaped latch portion 29, holes 24 and 19 and a notch 20 and is best seen in FIGS. 4 and 5. The trigger element 7 is rotatably mounted on a pivot pin 23 and is slideably contained in slot 40 formed by the body halves 21 and 22. The shaped latch portion 29 engages the rim 38 of the container 31 when in the cocked position as shown in FIG. 4. The spring 33 urged container 31 causes trigger element 7 to rotate counterclockwise as shown in FIG. 4 around pivot pin 23 and therefore will be held against the interior surface of slot 40 formed by body halves 21 and 22, thus retaining the container 31 in its cocked position.
The container 31 may be locked in its cocked position and the trigger element 7 in its set position as shown in FIG. 4 by means of a safety pin 16 which passes through hole 17 in body half 21, next through hole 19 in trigger element 7 and hence through hole 18 in body half 22. Holes 17, 18, 19 are coaxial on assembly and cocking of trigger element 7 and are perpendicular to the plane of travel of the trigger element 7 such that when safety pin 16 is inserted through holes 17, 18 and 19 the trigger element 7 is restrained from moving, thereby, safely retaining the container 31 in its cocked position.
A notch, 20, is provided near the end of the trigger element 7. The looped cord 5 is connected at one end to the window sash 3 and at its other end to the trigger element 7 by being looped over trigger element 7 to engage notch 20. When it is desired to place the device in condition for firing upon opening of the window sash 3; the safety pin 16 is removed from holes 17, 18 and 19. If the window sash is opened by a burglar or other intruder, the cord 5 will be pulled in such a manner as to rotate the trigger element 7 moving the shaped latch portion 29 out of engagement from the rim 38 of the container 31 permitting said container 31 to be thrust in direction 12 and seating the container spout 35 into entry section 36. In such position, as shown in FIG. 5, the pressure from spring 33 acting on the container 31 causes the pressurized chemical irritant 13 to be discharged through the passageway 41 and dispensing head 14 into the protected area as shown in FIG. 2.
After the device has been fired in the manner described herein above, the body halves can be separated to replace the container 31, after restoring trigger element 7 to its cocked position as depicted in FIG. 4.
It is an important feature that the trigger element 7 be rotatable and that the shaped latch portion 29 thereof present a surface which will slide smoothly on the rim 38 of the container 31 when the trigger element 7 is pulled. As a consequence the trigger element 7 may be easily withdrawn from engagement without substantial force. Yet when the trigger element 7 is positioned in engagement with the rim 38 of the container 31, the trigger element 7 serves to positively retain container 31 in its cocked position. Hence substantially less force is required to trigger device 6 of the present invention than would be required if the container 31 were retained in its cocked position by means of a transversely extending trigger pin or the like, yet the container 31 is still safely retained in its locked position against accidental release by safety pin 16 passing through holes 17, 18 and 19.
Yet another important feature is that the dispensing head 14 is rotatable in socket hole 37 through a large angle up to 360 degrees so that the chemical irritant spray 13 may be directed into any area relative to the triggering object such as when it is desired to spray into the area after an unauthorized person moves a triggering object or entryway at a corner of the area to be protected.
Another important feature is that the spring 33 be of substantial force so that the projecting dispensing spout 35 will seat in the entry section 36 with sufficient force to release the pressurized chemical irritant through the passageway 41 and out the dispensing head 14.
If it is desired to utilize the chemical irritant anti-burglar device again, it is reset as illustrated in FIG. 1. If it is desired to render it temporarily inoperative, the safety pin 16 is inserted through the passages 17, 18 and 19 to lock the trigger element 7 and thence the container 31 in its cocked position.
Another important feature is that the slot 48 in body halves 21 and 22 for inserting the looped cord 5 be made with a minimum clearance for the looped portion of the cord 5. It is also important to keep the opening 10 of the loop 9 of cord 5, as shown in FIG. 30, just wide enough to slip over the end of trigger element 7. By keeping the loop 9 and the slot 48 in body halves 21 and 22 as narrow as possible; it becomes very difficult; if not impossible, to move the trigger element 7 without a specially shaped loop or hook placed in slot 20 of trigger element 7. This is necessary to keep small children from accidentally triggering the device.
Further security from accidental release is achieved by keeping the trigger element 7 flush with or recessed from the exterior surface of the body halves 21 and 22. By mounting the trigger element 7 in the body halves 21 and 22 in this manner, there is no surface of the trigger element 7 exposed to grip and therefore cannot be released.
It is also important in this embodiment that the discharging means comprises a valved pressurized container 31, having a projecting dispensing spout 35 which when depressed causes fluid discharge therethrough. The body member 11 contains a fluid passageway 41 having a funnel shaped entry section 36 against which the projecting dispensing spout 35 is depressed and forms a seal between the entry section 36 of the passageway 41 and the projecting dispensing spout 35 when the pressurized container 31 is released, thereby causing fluid discharge from pressurized container 31 through the passageway 41.
A second embodiment of the invention is illustrated in FIG. 7. In this embodiment the basic structure is as previously described and like numbers are used to indicate like or corresponding parts.
In this embodiment, the pressurized chemical irritant container 31, shown in FIG. 4 having a projecting dispensing spout 35, is replaced with a pressurized chemical irritant container 51, shown in FIG. 7, having a recessed valve. Pressurized containers of the aerosol type with a recessed dispensing valve are well known in the trade. In addition, the conical shape of the entry section 36 of the fluid passageway 41 of the first embodiment shown in FIG. 4 is replaced with projecting spout 54 depending from body halves 58 and 59, all of which are shown in FIG. 7.
In this embodiment, all elements function as described in the first embodiment with the following difference. The pressurized container 51 is discharged by the action of the coil spring 33 moving the pressurized container 51 such that the recessed valve of the pressurized container 51 is depressed through engagement with projecting spout 54 and thereby effects discharge.
The chemical irritant 13 is then discharged through the valve of the pressurized container 51, through the entry section 54 and passageway 55 and out the dispensing head 14, then into the area to be protected.
As shown in FIG. 7, when the cord 5 is pulled and the safety pin 16 removed, the trigger element 7 is rotated. This causes the shaped latch portion 29 to be moved from container rim 57 and permits the container 51 to be moved in direction 56, causing discharge through the action of the projecting dispensing spout 54 acting on the recessed valve of container 51. The fluid will then be forced up through passageway 55 and dispersed through orifice 15.
It is important in this embodiment that the discharging means comprises a valved pressurized container 31 having a recessed valve which when depressed causes discharge therethrough. The body member 11 contains a fluid passageway 55 having a projecting spout 54 depending from the body member 11 for engaging and activating the recessed valve of the pressurized container 31 when the pressurized container 31 is released thereby causing discharge.
A third embodiment of the invention is illustrated in FIG. 8. In this embodiment the structure is as previously described in the first embodiment and like numbers are used to indicate like or corresponding parts.
In this embodiment, the pressurized chemical irritant container 31, shown in FIG. 4 of the first embodiment and having a projecting dispensing spout 35, is replaced with a pressurized chemical irritant container 61 shown in FIG. 8, having a piercable seal 66. Pressurized containers having piercable seals are well known in the trade. In addition, the funnel shaped entry section 36 of the body halves 21 and 22 of the first embodiment shown in FIG. 4 are replaced with body halves 68 and 69 having a projecting section 63 shaped to pierce seal 66 and a means of making a fluid seal capable of withstanding the pressure required for effectively discharging the chemical irritant through the passageway 65 and into the restricted area.
Now referring to FIG. 8, FIG. 8 is an inverted embodiment of FIG. 4 of the first embodiment in which all elements function as described in the first embodiment with the following exceptions. The pressurized cylinder 61, when released by the trigger element 7, is forced by spring 33, into piercable engagement with the piercing projecting section 63. As the piercable seal 66 is pierced by the action of the projection forward section 63 of the body halves 68 and 69, the spring 33 continues to move the container 61, forming a seal by the action of the O-Ring 67 and its retaining seat 64 and the piercable seal 66 of the pressurized container 61. The chemical irritant 13 is then discharged through the pierced seal 66 of the pressurized container 61, through passageway 65, out the orifice 15, and then into the area to be protected. It is important in this embodiment that the discharge means comprises a pressurized container 61 having a pierceable seal 66 which when pierced will permit fluid discharge therethrough. The body member 11 contains a projecting piercing section 63 depending from the body member 11 set in a position to pierce the piercable seal 66 when the pressurized container 61 is moved toward it. It is also important that a seal 67 be made to prevent fluid leakage within the body member 11 after the pierceable seal 66 is pierced and fluid is discharged through passageway 65.
The preceding embodiments of the invention show the chemical dispensing anti-burglary device in its preferred embodiments containing a rotatable trigger element 7 but it is recognized that the trigger element 7 may be slidably mounted as shown in FIG. 9 and 10. In addition, the body member may be constructed in a different manner as shown in FIGS. 9 and 10.
Therefore, a fourth embodiment of the invention is illustrated in FIG. 9 and 10. In this embodiment, the basic structure is as previously described in the first embodiment and like numbers are used to indicate like or similar parts.
In this embodiment, as shown in FIGS. 9 an 10, the body member 94 is constructed of a lower body section 80 and an upper body section 81. The exterior of lower body section 80 is round in shape while the interior comprises of two coaxial cylindrical bores 82 and 83. The cylindrical bore 82 slideable supports the pressurized contaner 31 and the cylindrical bore 83 serves to mount the spring 33.
The upper body section 81 is rectangular in shape and contains a round bore 84 sized to receive the upper most portion 85 of the lower body section 80 as shown in FIG. 10. Adhesives are used to fasten the two body sections 80 and 81 after assembly.
A slot 86 is formed in the upper body section slideably mount a flat trigger element 87. It is important that the catch 88 on the trigger element 87 slide freely on the flange 38 of pressurized container 31 and also in the slot 86.
A cylindrical bore 89 must also be formed in the upper body section 81 to provide clearance for the pressurized container 31. A fluid passageway 41 and a funnel entry section 36 must also be formed in upper body section 81 which is coaxial with but displaced from the dispensing spout 35 of container 31.
A wide slot 90 is provided where the cord 5 is slipped over the slot 91 in the trigger element 87. It is important that this slot be no wider then required for the clearance of the cord 5 to prevent someone from accidently triggering the device when the cord is removed.
An additional safety is provided by a safety pin 16 which operates in a manner previously described.
When it is desired to activate this device, the cord 5 is connected in slot 91 of trigger element 87 and the safety pin 16 is removed as previously described. An intruder causing the cord 5 to be pulled will slide the trigger element 87 from engagement with the contaner 31. Thus permitting the spring 33 to move the container 31 in a manner to cause the dispensing spout 35 to move into engagement with the entry section 36 of the fluid passageway 41 and cause discharge in a manner previously described,
This type of trigger element does not have the mechanical advantage of the rotatable trigger element and requres more force to release the container but can be effectively used for many applications.
A fifth embodiment of the invention is illustrated in FIGS. 11, 12 and 13. In this embodiment, the structure is as previously described in the first embodiment and like numbers are used to indicate like or corresponding parts.
In this embodiment, the projecting dispensing spout 35 of pressurized chemical irritant contaner 31, shown in FIG. 4, is replaced with a projecting dispensing cap 73 shown in FIG. 11, 12 and 13. In addition, the fluid passageway 41 and the entry section 36 are replaced with an aperature 72.
Now referring to FIG. 12 and FIG. 13, the trigger element 7 and the spring 33 operate as before to move the pressurized container 31. In this embodiment, the spring 33 urged pressurized container 31 causes the projecting cap 73 to be depressed against the inside top portion 76 of body halves 70 and 71; thereby causing discharge through aperature 72. It is important in this embodiment that the discharging means comprises a valved pressurized container 31 having a projecting dispensing cap 73 which when depressed causes fluid discharge therethrough. The body member 11 contains an aperture 72 in communication with the projecting dispensing cap 73 to provide for fluid discharge from the body member 11. It is also important that a means be provided in the body member 11 to restrict the movement of the projecting dispensing cap 73 to provide a means to cause fluid discharge upon movement of the pressurized container 31. One means for restricting the movement of the dispensing cap 73 is to provide a surface 76 in body member 11 which will restrict the movement of the dispensing cap 73 when the pressurized container 31 is released. Fluid will be discharged from the pressurized container 31 through the dispensing cap 73 and aperture 72 when the dispensing cap 73 is moved against surface 76 through movement of pressurized container 31.
A sixth embodiment of the invention is illustrated in FIGS. 14-21. In this embodiment the basic structure is previously described in the first embodiment and like numbers are used to indicate like or corresponding parts.
In the anti-burglar device 6 previously described, the trigger element 7 is released when cord 5 is pulled. The trigger element 7 holds the pressurized container in a cocked position. In this embodiment, the trigger element 7 is replaced by a self-camming trigger element 107 as best seen in FIGS. 17 and 18 wherein a self-camming trigger element 107 will be forced to rotate in the direction of arrow 149 by the action of the flange 38 on the pressurized container 31 of the spring 33 urged pressurized container 31. The operation of this self-camming trigger element 107 will become apparent in the following description.
As shown in FIG. 14 and 15, the device 106 can be remotely mounted from a window or other object or entryway to be protected and connected by means of an electrical cable 105 to an electrical switch 110; and on-off switch 126 and a power source 109, so that upon opening the window sash 3 by an unauthorized person, the contacts of switch 110 will close as a result of switch activation pin 111 releasing contact lever 108 of switch 110 electromechanically causing the device 106 to discharge a chemical irritant 13 into the area to be protected. This embodiment of the device comprises of all the components previously described except for the change in the method of triggering previously described and an addition of an electromechanical actuator 141.
Now referring to FIGS. 16-21, an electromechanical actuator 141 is shown. The electromechanical actuator 141 comprises an electromagnetic coil 142, a solenoid latch lever 143, a lever pivot point 144 and a latch lever spring 146. The components of the electromechanical actuator 141 are arranged in a manner that when power is applied to the electromagnetic coil 142, a magnetic flux is generated, causing the latch lever 143 to be attracted toward the coil 142 and to rotate around pivot point 144. THe rotation of the latch lever 143 will be confined from further movement by the electromagnetic coil 142. The latch lever 143 is held in a normal rest position by the action of spring 146 exerting force on the latch lever 143 in direction opposite of arrow 147. This causes the catch 145 of latch lever 143 to move in the same direction and causes the latch lever 143 to rest against the self-camming trigger element 107 and prevent the self-camming trigger element 107 from rotating in the direction 149.
As can be best seen in FIG. 17, the rim 38 of the pressurized container 31 of the spring 33 urged pressurized container 31 engages with the latch portion 129 of the self-camming trigger element 107 causing it to rotate in the direction of arrow 149 about pivot pin 23. The self-camming trigger element 107 is releasably retained from rotating by the catch 145 of the latch lever 143 which is restrained from transverse movement by the pivot point 144.
When switch 110 is closed, electric power is applied to the electromagnetic coil 142, thus, energizing the electromagnetic coil 142. The solenoid latch lever 143 is pulled toward the electromagnetic coil 142 in direction 147 around pivot point 144 thereby moving the latch lever catch 145 away from engagement with the self-camming trigger element 107 at notch 120; whereupon the rim 38 of the pressurized container 31 of the spring 33 urged pressurized container 31 engaging with the latch portion 129 of the self-camming trigger element 107 causes the self-camming trigger element 107 to rotate in the direction of arrow 149. This permits the spring 33 urged pressurized container 31 to be moved in the direction of arrow 112 until the projecting dispensing spout 35 of the pressurized container 31 is in seated engagement with the entry section 36; further movement of the pressurized container 31 will depress the projecting dispensing spout 35 and cause the chemical irritant 13 to be released from the pressurized container 31; through the dispensing spout 35, the entry section 36, the fluid passageway 41 and the orifice 15 in dispensing head 14.
It is an important feature that the self-camming trigger element 107 be rotatable and that the catch 145 of the latch lever 143 slide freely on the notch 120 of the self-camming trigger element 107, hence a consistent release of the latch lever 143 may be obtained on a limited amount of electric power. Yet the self-camming trigger element 107 is positioned in its cocked position in engagement with the latch lever 143, the spring 33 urged pressurized container 31 is securely held in a cocked position safe against accidental release.
With the self-camming trigger element 107 in the cocked position shown in FIG. 19, the safety pin 16 may be inserted in holes 117 and 118 to safely lock the self-camming trigger element 107 from accidental discharge.
It is also an important feature that the catch 145 moves in a direction perpendicular to the plane of movement of self-camming trigger element 107 thereby requiring only a small movement of the latch lever 143 permitting the use of a smaller, lower powered electromechanical actuator 141 than would be required of a self-camming trigger element 107 was moved throughout its entire range by electromechanical action or then would be required by an electromechanical actuator acting transversly on the rim 38 of the pressurized container 31.
A seventh embodiment of the invention is illustrated in FIG. 22. In this embodiment the basic structure is previously described in the first embodiment and like numbers are used to indicate like or corresponding parts.
In this embodiment, the self-camming trigger element 107 is replaced by a self-camming trigger element 97 wherein the notch 120 is replaced with a projection 92. In addition, the electromechanical actuator 141 has been eliminated and the self-camming trigger element 97 is restrained by a movable object 93. This device 206 is identical to device 106 with the exception of the electromechanical actuator 141 and method of being triggered.
The releasably retaining means acting on the self-camming trigger element 97 is a movable object 93. Any movable object such as a window, door, TV set, Hi Fi set etc. can be mounted to retain the self-camming trigger element 97. If it is desired to move the protected object, the safety pin 16, previously described in inserted in a manner to engage hole 19 in self-camming trigger element 107 thus safely deactivating the device. However, if properly installed, the intruder will not notice the device 206 and move the protected object and cause discharge.
An eighth embodiment of the invention is illustrated in FIGS. 23-25. In this embodiment, the basic structure is as described in the sixth embodiment and like numbers are used to indicate like or corresponding parts. The chemical dispensing anti-burglary evice of this embodiment is generally noted device 306.
In this embodiment, the releasably retaining means acting on the self-camming trigger element 107, is a fusible link 325 which replaces the electromechanical actuator 141 of the sixth embodiment. The fusible link 325 will safely retain the self-camming trigger element 107 from rotation until an electric current is passed through the fusible link 325 in a manner previously described, in the sixth embodiment, causing fusible link 325 to melt and release the self-camming trigger element 107 which causes discharge. The fusible link 325 shown in FIGS. 23-25 may also replace the electromechanical actuator 141 in the sixth embodiment shown in FIGS. 16-21.
A ninth embodiment of the invention is illustrated in FIGS. 26-29. In this embodiment, the structure is as previously described in the first embodiment and like numbers are used to indicate like or corresponding parts.
In this embodiment, the trigger element 7 is replaced by a trigger element 407 wherein the notch 20 of trigger element 7 is replaced with an extension 171. In addition, the device 406 is equipped with an electromechanical actuator 172 of the solenoid push type wherein the solenoid plunger 173 is mounted to engage the extension 171 of trigger element 407.
The device 406 is installed in the manner described in the sixth embodiment and shown in FIGS. 14 and 15 wherein the device 106 is replaced by evice 406. As the window 3 is raised; the solenoid coil 172 is energized and the plunger 173 moves in the direction 153, pushing on extension 171 of trigger element 407. This releases the pressurized container 31, previously described and discharges the device.
The chemical dispensing anti-burglary device described herein in several embodiments was generally shown with a pressurized container 31 with a projecting dispensing spout 35 mounted to discharge into a funnel like entry section 36 of a fluid passageway 41 when the device is discharged. Alternately the device will also function with a pressurized container of the aerosol type with a recessed valve by providing a tubular member depending from the body member to cause discharge; in additon the devices can be used with a sealed pressurized container with a piercable seal; also the aerosol type container with a dispensing projecting cap wherein the projecting cap is depressed to cause discharge; but the invention is not limited to these type of containers.
Although I have herein shown and described the invention in what I have conceived to be the most practical and preferred embodiments, it is recognized that departure may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims so as to embrace any and all equivalent structures and devices.
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A chemical dispensing anti-burglary device is described in which a chemical irritant such as tear gas is discharged into the area to be protected when an intruder opens a window or opens a door or enters an unauthorized area with which the device is associated. The anti-burglary device employs a spring biased pressurized container for discharging a chemical through a passageway and nozzle. A mechanical trigger for releasably retaining the pressurized container in a cocked position, an improved mechanical and electromechanical trigger to release the chemical, and a built in safety to deactivate the device which makes it virtually impossible to accidentally discharge the device are described.
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FIELD OF THE INVENTION
The present invention relates to swimming pool cleaners and, more particularly, to automatic pool cleaners driven by the flow of water therethrough for purposes of cleaning. Still more particularly, the invention relates to wheeled automatic swimming pool cleaners.
BACKGROUND OF THE INVENTION
Automatic swimming pool cleaners of the type that move about the underwater surfaces of a swimming pool are driven by many different kinds of systems. A variety of different pool cleaner drive devices in one way or another harness the flow of water, as it is drawn (or in some cases pushed) through the pool cleaner by the pumping action of a remote pump for debris collection purposes, to create forward pool cleaner movement. Some of the many kinds of water-driven automatic pool cleaners are those driven in various ways by turbines, which translate water movement into rotational motion, and those driven in various ways by oscillators, which move back and back and forth by virtue of Bernoulli's principle, a motion which can be converted into intermittent unidirectional rotation and harnessed in various ways.
Various water-driven automatic pool cleaners of the prior art are four-wheel structures supported on underwater surfaces by wheels. Wheel rotation by linkage to a turbine or other drive mechanism causes propulsion in such prior art devices. Various problems and shortcoming exist in such prior devices.
Among the problems and shortcomings not adequately addressed are failures of certain kinds of cleaners to provide complete cleaning coverage. Obtaining complete coverage is particularly difficult or problematic for swimming pools having certain kinds of surfaces, surface shapes or obstacles. Complete coverage, and thus satisfactory cleaning, are difficult to obtain when the pumping pressure generated by the pump is weak, such that the driving force of a pool cleaner is seriously diminished. Various automatic pool cleaners of the prior art have insufficient speed and strength of movement, and this creates and exacerbates problems of weak cleaning ability. Some problems, failures or difficulties occur when pool cleaners get hung up or caught at an area where its driving wheels are unable to contact the underwater pool surfaces, or are at least unable to engage such surfaces with sufficient traction to allow movement of the pool cleaner. For some cleaners of the prior art, steering (that is, the motions taken by pool cleaners in order to change directions) can be problematic, particularly on certain kinds of surfaces and when speed is low and the steering and propulsion forces that are generated are low.
Various advances have been made over the years, but there remains a need for an automatic water-driven pool cleaner, particularly of wheeled kind, having improved function in movement and in cleaning ability.
OBJECTS OF THE INVENTION
It is an object of this invention to provide an improved automatic swimming pool cleaner, particularly of the water-driven type, overcoming some of the problems and shortcomings of the prior art.
Another object of this invention is to provide an improved wheeled automatic swimming pool cleaner of the water-driven type.
Another object is to provide an improved wheeled automatic swimming pool cleaner of the water-driven type has excellent driving force along underwater pool surfaces.
Another object of the invention is to provide an improved wheeled automatic swimming pool cleaner of the water-driven type which has excellent traction in a variety of situations.
Still another object of the invention is to provide an improved wheeled automatic swimming pool cleaner of the water-driven type which has excellent ability to traverse pool surfaces of different types and hard-to-reach pool areas.
Yet another object of the invention is to provide an improved automatic pool cleaner of the water-driven type exhibiting excellent cleaning ability.
Another object of the invention is to provide an improved wheeled automatic swimming pool cleaner of the water-driven type which generates good driving power even when used with pool pumping systems generating low pumping pressures.
Another object of the invention is to provide an improved wheeled automatic swimming pool cleaner which resists any tendency to become hung up and is capable of extracting itself from situations in which there is a lack of traction.
Still another object is to provide an improved automatic swimming pool cleaner with excellent speed and steering (direction-changing) capabilities.
These and other objects of the invention will be apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
This invention is an improved automatic swimming pool cleaner of the type motivated by water flow through it to move along a pool surface to be cleaned, and of the particular type having four wheels in contact with the underwater pool surfaces. The invention, including in its preferred embodiments, overcomes various problems and shortcomings of the prior art, including those referred to above.
The automatic swimming pool cleaner of this invention provides important advantages, including the following: excellent driving force along underwater surfaces; excellent traction in a variety of situations; an ability to traverse pool surfaces of different types and hard-to-reach pool areas; excellent cleaning coverage of underwater surfaces; effective pool cleaner operation at low pressure; good speed and power, even at low pressures; reliable take-up of debris; highly-reliable steering; an ability to avoid and/or escape situations involving hang-up of the pool cleaner; and good adaptability to desired variations in cleaner structure.
The inventive automatic pool cleaner includes: a body having a front, a rear and opposite sides; four wheels rotatably mounted with respect to the body and including first and second sets of two wheels each, each set having one wheel on each side of the body; a drive mechanism secured with respect to the body in position to be activated by the flow of water through the pool cleaner, the drive mechanism including a rotatable drive member; drive train from the drive member to the first set of wheels and to the second set of wheels, such that all four wheels are driven.
In preferred embodiments, the drive train includes a first drive-train portion from the drive member to the first set of wheels, a second drive-train portion from one wheel of the first set to one wheel of the second set, and a third drive-train portion from to the other wheel of the first set to the other wheel of the second set.
In preferred embodiments the drive mechanism is a turbine including a turbine rotor secured to the body in position to be rotated by the flow of water. The drive member is secured with respect to the rotor and is rotatable with the rotor.
Highly preferred embodiments of the type having turbines as drive mechanisms include: a turbine housing secured to the body and having a water-flow chamber formed by a chamber wall, the chamber having inlet and outlet ports; the turbine rotor being rotatably mounted in the chamber; and turbine vanes having proximal ends connected to the rotor and distal ends which are movable between extended positions adjacent to the wall and retracted positions spaced from the wall and closer to the rotor, in order to allow passage of debris pieces of substantial size through the turbine.
Preferably, the vanes are pivotably mounted with respect to the rotor. The vanes are preferably curved and the distal edges of the vanes are able to contact the chamber wall in at least some of their extended positions. In highly preferred embodiments of this type, the rotor has an exterior surface beneath which, for each vane, is a corresponding cavity which pivotably holds the proximal edge of the vane. The vanes preferably have enlargements at their proximal edges sized for free insertion into, and pivotable engagement in, the cavities.
These highly preferred forms of turbines are the subject of U.S. Pat. No. 6,292,970, entitled “Turbine-Driven Automatic Swimming Pool Cleaners,” filed by Dieter J. Rief and Manuela Rief, both inventors herein, and Rosemarie Rief, on May 23, 2000.
While the drive mechanism included in the pool cleaner of this invention is preferably a turbine, and most preferably a turbine having the preferred features just described, the drive mechanism can be other kinds of devices capable of rotating a drive member. For example, oscillating drive mechanisms which utilize Bernoulli's principle to establish and maintain oscillation of an oscillator may be used. As is known to those skilled in the art, oscillating rotation can be translated into intermittent unidirectional rotation by ratcheting devices or otherwise; thus, oscillators can drive the rotatable drive member referred to above.
Each of the four wheels, of course, has an inward side and an outward side depending upon how it is mounted on the pool cleaner. In preferred embodiments of this invention, the first wheel of the first set has radially-spaced primary and secondary wheelgears on its inward side, such wheelgears facing one another, and the second wheel of the first set has another primary wheelgear on its inward side, the primary wheelgears on the two wheels of the first set being similar to one another. Preferably, the drive train terminates at the first and second wheels of the first set in first and second drive pinions, respectively, each engaging the primary wheelgear of the respective wheel of such set; this serves to drive the wheels of the first set in the forward direction synchronously, in contact with the underwater pool surface.
In such embodiments, it is highly preferred that the wheelgears of the first wheel of the first set be concentric with one another, and integrally formed with the first wheel itself. The wheelgear of the second wheel of the first set is also preferably integrally formed with the second wheel. Most preferably, the first and second wheels of the first set are identical, and therefore interchangeable.
As used herein, the term “wheelgear” refers to any gear which is affixed on, or formed as part of, a swimming pool cleaner wheel which contacts the surface of the pool to propel the pool cleaner.
In preferred embodiments, each of the wheels of the second set of wheels has what is being called a “final” wheelgear on its outward side. In such embodiments, each of the second and third drive-train portions mentioned above includes a transfer shaft journaled with respect to the body, a first transfer pinion engaged with one of the primary wheelgears, and a second transfer pinion engaged with one of the final wheelgears. By virtue of these drive-train portions, the wheels of the first set impart their rotation of the wheels of the second set. Preferably, each transfer shaft itself forms the first and second transfer pinions at the opposite ends thereof.
It is preferred that all four wheels, including the second set each of which has a “final” wheelgear on it, have their wheelgears integrally formed with the wheel. Most preferably, all four wheels are identical and completely interchangeable.
In preferred embodiments, the drive member is a drive gear and the drive train includes first and second drive shafts which are journaled with respect to the body and which have proximal and distal ends. In such embodiments, the first and second drive pinions, mentioned above, are driven by the first and second drive shafts, respectively, and the drive train is a gear train from the drive gear to the first and second drive shafts. Preferably, the first and second drive shafts form the first and second drive pinions, respectively, at their distal ends.
The drive train preferably includes a coupler with opposite ends receiving the proximal ends of the first and second drive shafts. The proximal end of the first drive shaft is a ball joint which allows the first drive shaft to be pivoted off-axis. This allows the distal end of the first drive shaft to be moved fore-and-aft between a driving position, in which the first drive pinion engages the primary wheelgear of the first wheel of the first set, and a steering position, in which the first drive pinion engages the secondary wheelgear of such first wheel. This movement, from engagement with a wheelgear in the form of a ring gear (i.e., with radially inwardly-facing teeth) to engagement with a wheelgear having radially outwardly-facing teeth, causes the first wheel of the first set to change its direction of rotation—i.e., to rotate in a direction opposite that of the second wheel of the first set. This interrupts the synchronous rotation of the wheels on the pool surface, and causes turning of the pool cleaner.
Highly preferred embodiments include apparatus to achieve the fore-and-aft movement of the distal end of the first drive shaft. Such apparatus preferably includes: a shift bracket assembly which is slidably held by the body and has the first drive shaft journaled in it for distal-end movement between the driving and steering positions; a cam wheel rotatably secured with respect to the body and engaging the shift bracket assembly, the cam wheel having portions of greater and lesser radii; a reduction gear assembly secured to the body and linking the drive mechanism with the cam wheel such that rotation of the cam wheel is related to rotation of the drive member; and a spring which is positioned and supported to bias the shift bracket toward the cam wheel. By virtue of this apparatus the cam wheel, acting through the shift bracket assembly, alternately holds the distal end of the first drive shaft in the driving position and allows the distal end of the first drive shaft to move to the steering position.
In highly preferred embodiments, the wheels have treads with a multiplicity of outwardly extending radial fingers. It is most preferred that a small subset of the radial fingers (extending along a very small sector of the wheel) project radially farther than the other fingers. With this embodiment, if the pool cleaner for any reason is hung up on some obstruction or pool surface feature, the longer treads, when they come around, tend to provide traction for dislodgement purposes.
In certain preferred embodiments, the aforementioned water inlet faces the surface of the pool and the pool cleaner includes a skirt secured with respect to the body and extending toward the pool surface such that the skirt and the body, together with the pool surface, form a plenum from which water and debris are drawn into the inlet. The skirt is formed of at least one flap member which has upper and lower articulating portions, the upper articulating portion having a proximal end hinged to the body and a distal end hinged to the lower articulating portion. Most preferably, the skirt is segmented in that it is formed of a plurality of the articulated flap members in side-by-side arrangement, each having upper and lower articulating portions.
Such skirt, which is the subject of commonly-owned copending U.S. Pat. No. 6,131,227, entitled “Suction-Regulating Skirt for Automated Swimming Pool Cleaner Heads,” filed by Dieter J. Rief, an inventor herein, and Hans Raines Schlitzer on May 21, 1999, facilitates relative enclosure of the plenum despite encountered irregularities in the pool surface immediately under the pool cleaner. As water is drawn into the turbine chamber through the inlet, the skirt minimizes the openness between the pool cleaner body and the underwater surface of the pool, and this causes a speed-up in the linear flow of water immediately along the underwater surface of the pool, at positions under the pool cleaner. Such speed-up of linear flow improves the ability of the pool cleaner to ingest debris along with water, so that the debris tends to move easily into the turbine chamber, and from there through the outlet and into a bag or other collector.
In certain preferred forms, the inventive automatic pool cleaners are suction cleaners. In other preferred forms, the inventive automatic pool cleaners are pressure cleaners. Certain highly preferred forms of swimming pool pressure cleaners are the subjects of PCT Patent Application No. PCT/US00/14770, entitled “Swimming Pool Pressure Cleaner with Internal Steering Mechanism,” concurrently filed by the applicant herein on an invention of Dieter J. Rief and Manuela Rief, the inventors herein.
While the drive mechanism included in the pool cleaner of this invention is preferably a turbine, and most preferably a turbine having the particular features referred to above, the drive mechanism can be other kinds of devices which are capable of rotating a drive member. For example, oscillating drive mechanisms which utilize Bernoulli's principle to establish and maintain oscillation of an oscillator may be used. As is known to those skilled in the art, oscillating rotation can be translated into intermittent unidirectional rotation by ratcheting or other devices; thus, oscillators can drive the rotatable drive member referred to above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred automatic pool cleaner in accordance with this invention, taken generally from the rear. The device is a suction cleaner.
FIG. 2 is a front elevation of the device of FIG. 1 .
FIG. 3 is a left side elevation of the device of FIG. 1 .
FIG. 4 is a rear elevation of the device of FIG. 1 .
FIG. 5 is a top plan view of the device of FIG. 1 .
FIG. 6 is a detailed top sectional of the device of FIG. 1 .
FIG. 7 is a side sectional taken along stepped section 7 — 7 as indicated in FIG. 6 , but with certain parts and details not included to enhance clarity.
FIG. 8 is a perspective of one of the drive wheels, with its annular tread piece removed.
FIG. 9 is a perspective of the tread piece.
FIG. 10 is a schematic sectional side elevation illustrating portions of another embodiment of the invention, a swimming pool pressure cleaner.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1-9 illustrate a preferred automatic swimming pool cleaner 20 in accordance with this invention. Pool cleaner 20 has four identical drive wheels marked by numeral 22 , including left front drive wheel 22 a, right front drive wheel 22 b, and left and right rear drive wheels 22 c and 22 d. All four drive wheels are driven to provide forward movement of pool cleaner 20 . Rear drive wheels 22 c and 22 d are driven by separate linkages from front wheels 22 a and 22 b, respectively.
Left front drive wheel 22 a, which is normally driven in a forward direction, is periodically temporarily driven in a reverse direction. When this occurs, left rear drive wheel 22 c is also driven in a reverse direction by virtue of the linkage between drive wheels 22 a and 22 c. During such brief intermittent periods of reverse rotation, the direction of travel of pool cleaner 20 changes. This steering function, together with the power provided by four-wheel drive of this invention, provides excellent cleaning coverage of underwater pool surfaces.
Pool cleaner 20 includes a body 24 which is preferably formed of two or more plastic pieces designed to accommodate the parts and features of the invention. Front drive wheels 22 a and 22 b are rotatably mounted with respect to body 24 on wheel shafts 26 , as shown in FIG. 6 . Attached to body 24 are rear wheel supports 28 , and rear wheels 22 c and 22 d are rotatably mounted thereon by wheel shafts 30 . Front wheels 22 a and 22 b have gearing (hereafter described) on their inward surfaces, i.e., the surfaces facing each other. Rear wheels 22 c and 22 d have the same gearing on their outward surfaces. Drive wheels 22 a-d are identical to each other, and thus are interchangeable.
The gearing on wheels 22 a-d includes concentric radially-spaced primary and secondary wheelgears 32 and 34 . Primary and secondary wheelgears 32 and 34 are radially spaced from one another by a distance in excess of the diameter of a pinion gear (hereafter described) which alternately engages such gears on drive wheel 22 a. While all wheels are interchangeable, only drive wheel 22 a uses both wheelgears, on drive wheels 22 b-d, only wheelgear 32 is used.
Pool cleaner 20 includes a drive mechanism which utilizes the flow of water through the pool cleaner to create rotary motion which is transferred to the wheels by a drive train. More specifically, pool cleaner 20 includes a turbine 36 , part of which, notably turbine housing 38 , is secured to body 24 . (As used with respect to turbine housing 38 and body 24 , the term “secured to” includes having been formed together.)
Turbine housing 38 has a chamber 40 in it which is formed by a chamber wall 42 . Chamber 40 includes an inlet port 44 and an outlet port 46 . Turbine 36 also includes a rotor 48 , which is rotatably mounted within chamber 40 , and a number of turbine vanes 50 , each of which has proximal and distal edges 50 a and 50 b. Proximal edge 50 a of each vane 50 is generally cylindrical in shape and is loosely received within a generally cylindrical void in rotor 48 , formed just below the outer surface of the rotor. Thus, vanes 50 , which are of a curved configuration, freely move between fully extended positions in which they contact chamber wall 42 and retracted positions in which their distal edges 50 b are closer to rotor 48 and spaced from chamber wall 42 . This provides free adjustability of vanes 50 to allow large pieces of debris to pass through chamber 40 without interfering with operation of the turbine.
Turbine 36 , shown in FIG. 7 , serves two functions, providing power to drive wheels 22 a-d through linkages (hereafter described) and providing power for operation of a steering device (hereafter described), both of which occur as water and debris are drawn through it by the action of a remote pump. A flexible hose (not shown) is rotatably attached to hose coupling 52 (in known fashion) and draws water from beneath pool cleaner 20 through inlet port 44 , turbine 36 and outlet port 46 .
Beneath pool cleaner 20 , water inlet port 44 faces the pool surface 54 . Pool cleaner 20 includes a segmented skirt which has forward and rearward portions, each of which includes a number of flap members 56 arranged in side by side relationship. Together, flap members 56 and body 24 form a plenum 62 . Each flap member 56 includes an upper articulating portion 58 and a lower articulating portion 60 . Upper portion 58 has a proximal end 58 a which is hinged to body 24 and a distal end 58 b which is hinged to a proximal end 60 a of upper portion 60 . By virtue of this design, flap members 56 self-adjust to the contours of the pool surface 54 . Flap members 56 serve to keep plenum 62 substantially closed, which provides flow characteristics favorable for collection of debris from beneath pool cleaner 20 by the suction action.
While pool cleaner 20 is a suction cleaner, an alternative pool cleaner 63 , which is a pressure cleaner, is shown in FIG. 10 . Pressure cleaner 63 has a turbine 68 and related portions which differ from their counterparts in pool cleaner 20 . Pressure cleaner 63 , instead of operating by harnessing the suction of water through a pool cleaner, operates by harnessing a positive flow of water to a pool cleaner through a pool cleaner hose (not shown), which is attached to a swiveling hose coupling (not shown). The water from the hose flows through conduits 64 and conduit branches 64 a and 64 b, and ultimately through venturi jets 66 a and 66 b into turbine 68 . It should be remembered that FIG. 10 is schematic; it omits a number of parts and does not purport to show the location or the structure providing conduits for flow of water from the hose to the venturi jets.
As shown in FIG. 10 , turbine 68 has a larger inlet 70 facing the pool surface (not shown) than is used in pool cleaner 20 , described above. Venturi jets 66 a and 66 b are located at or near inlet 70 and are oriented to direct water upwardly into inlet 70 and toward outlet 72 . The venturi jets, particularly venturi jet 66 a, are located to cause rotation of the rotor of turbine 68 to provide driving and steering power for pressure cleaner 63 . A venturi action caused by venturi jets 66 a and 66 b draws water and debris from beneath pool cleaner 63 into inlet port 70 , and causes such water and debris to flow upwardly through turbine 68 and outlet port 72 into a collection bag 74 , which acts as a filter.
The venturi action is caused by the accelerated flow of water created by jets 66 a and 66 b. The accelerated flow of water creates a pressure differential which causes an upward suction of water and debris from adjacent on the pool surface into inlet 70 . Thus, the venturi jets serve two purposes—driving the turbine and creating an upward flow from beneath the pool cleaner for cleaning purposes. The size and orientation of venturi jets 66 a and 66 b not only cause these actions, but serve to facilitate an essentially quick straight-line movement of debris into collection bag 74 .
In every other respect, pressure cleaner 63 is like suction cleaner 20 .
Referring again to pool cleaner 20 of FIGS. 1-9 , the following is a description of the manner in which the rotation of rotor 48 is transmitted to drive wheels 22 a-d. FIG. 6 is particularly helpful in illustrating the drive train and its three different portions. The three different portions include: (1) a first portion which extends from a first drive gear 76 , affixed to rotor 48 , to left and right front wheels 22 a and 22 b; (2) a second portion which extends from front wheel 22 a to rear wheel 22 c; and (3) a third portion which extends from front wheel 22 b to rear wheel 22 d. (The second and third portions of the drive train are identical to each other.) All four wheels are driven by first drive gear 76 ; a second drive gear 78 , which is affixed to the opposite side of rotor 48 , is used to control the steering of pool cleaner 20 . (First and second drive gears 76 and 78 are integrally formed with rotor 48 and are affixed to a rotor shaft 79 which is rotatably mounted with respect to body 24 .)
The first drive train portion includes left and right drive shafts 80 and 82 , sometimes referred to herein as “first” and “second” drive shafts. Drive shafts 80 and 82 are aligned end-to-end. The first drive train portion also has a gear train including gears 84 a, 84 b and 84 c. Gear 84 c serves as a coupler to receive the proximal ends 80 a and 82 a of drive shafts 80 and 82 . (Proximal end 80 a of drive shaft 80 forms a balljoint coupling with coupling gear 84 c, for steering purposes described below.) Drive shafts 80 and 82 terminate at their distal ends in pinion gears 86 a and 86 b, which are integrally formed with the shafts. Gears 86 a and 86 b engage primary wheelgears 32 of drive train wheels 22 a and 22 b, respectively. Thus, the rotation of rotor 48 causes synchronous rotation of front drive wheels 22 a and 22 b, each in the same direction.
The rotation of front drive wheels 22 a and 22 b causes rotation of rear drive wheels 22 c and 22 d, by means of the second and third portions of the drive train, which will now be described. Each of these identical drive-train portions end up engaging primary (or final) wheelgear 32 of one of rear drive wheels 22 c and 22 d. Adjacent to each rear wheel is a transfer shaft 88 which is journaled in body 24 by means of appropriate bearings. The opposite ends of each transfer shaft 88 include pinion gears 90 a and 90 b, which are formed as part of transfer shaft 88 . Each pinion gear 90 a engages primary wheelgear 32 of one of front drive wheels 22 a or 22 b, at a position spaced about 180° from the point of engagement of pinion gear 86 a or 86 b therewith. Each pinion gear 90 b engages primary (or final) wheelgear 32 of one of rear drive wheels 22 c and 22 d.
The operation of the steering mechanism will now be described. Left drive shaft 80 , which is generally in exact axial alignment with right drive shaft 82 , can be moved off-axis by virtue of the ball-joint at its proximal end 80 a. More specifically, pinion gear 86 a, which is formed at the distal end of left drive shaft 80 , is movable in fore-and-aft directions depending upon forces applied to drive shaft 80 , as hereafter described. FIG. 7 shows an oblong opening 92 in a portion of body 24 which accommodates such movement of left drive shaft 80 .
Pool cleaner 20 includes a shift bracket assembly 94 which is slidably held within a cavity 96 formed in body 24 . Left drive shaft 80 is journaled by suitable bearing means in shift bracket assembly 94 . Shift bracket assembly 94 includes a roller 98 at its rearward end for engagement by a cam wheel 100 which serves the purpose of controlling the position of shift bracket assembly 94 , either fore or aft. A spring 102 is located within cavity 96 in a position between a fixed surface of body 24 and the forward end of shift bracket assembly 94 . Spring 102 biases shift bracket assembly 94 into firm engagement with cam wheel 100 .
Since left drive shaft 80 is journaled in shift bracket assembly 94 , the position of pinion gear 86 a is determined by the fore-or-aft position of shift bracket assembly 94 . In the forward position, pinion gear 86 a engages primary wheelgear 32 of left front wheel 22 a; in the rearward position, it engages secondary wheelgear 34 of left front wheel 22 a. Left front wheel 22 a moves in a forward direction when pinion gear 86 a engages primary wheelgear 32 ; however, since the reverse side of pinion gear 86 a is what engages secondary wheelgear 34 when pinion gear 86 a is in the aft position, such engagement results in reverse rotation of left front wheel 22 a. And, by virtue of the driving linkage between left front wheel 22 a and left rear wheel 22 c, the aft position of pinion gear 86 a also reverses the rotational direction of left rear drive wheel 22 c. In other words, the periodic movement of shift bracket assembly 94 moves left drive shaft 80 and its pinion gear 86 a to the aft position, and this interrupts the synchronous rotation of the drive wheels and causes turning of pool cleaner 20 .
A major portion of cam wheel 100 has a fixed radius sufficient to allows cam wheel 100 to hold shift bracket assembly 94 in a forward position. Cam wheel 100 also has one or more smaller portions of lesser radius which allow shift bracket assembly 94 to move to its aft position under the biasing force of spring 102 .
Cam wheel 100 is rotatably supported on an extension 104 of rotor shaft 79 at a position spaced from rotor 48 . Also rotatably supported on extension 104 are several gear members of a reduction gear assembly 106 , the purpose of which is to reduce rotational speed such that cam wheel 100 turns slowly—at a rate such that its portions of greater or lesser radial dimension dwell in contact with roller 98 of shift bracket assembly 94 for reasonable periods of time. More specifically, the gearing and cam design are such that the pool cleaner 20 will move in a forward position most of the time, and only intermittently change directions for short periods of time.
Primary and secondary wheelgears 32 and 34 are integrally formed with each of the drive wheels 22 a-d. FIG. 8 illustrates the main portion of one such drive wheel, with its tread piece removed.
FIG. 9 illustrates a resilient elastomeric tread element 108 which is shaped for firm engagement about the periphery of the main portion of each drive wheel and to provide good traction. Tread element 108 has many outwardly extending resilient radial fingers 110 . These tread features on the drive wheels of the present invention provide increased traction on slippery surfaces. This tread in combination with the large size of the drive wheels, which are essentially as large in diameter as the pool cleaner is high, allows the cleaner to ride over commonly encountered impediments and obstacles in the pool environment, including main drains, pool liner wrinkles, and uneven, convex and concave surfaces. Such drive wheels in the four-wheel-drive pool cleaner of this invention also allow the pool cleaner to navigate a vertical wall which joins a pool bottom surface without any curved transition (or “radius”).
While elastomeric flexible treads are normally best, in certain applications, notably involving submerged tile surfaces, it may be preferable to fit the drive wheels with synthetic foam treads. When foam tread is used, effective grip and suction can be maintained on even the most slippery submerged inclined and vertical tile surfaces.
As shown in FIG. 9 , three consecutive radial fingers 110 a-c project radially farther than the others. As explained above, this serves to provide additional traction for dislodgement of the pool cleaner 20 , if needed. Radial finger 110 b extends slightly farther than radial fingers 110 a and 110 c.
Most of the parts of the pool cleaners of this invention may be formed using rigid plastic parts, as is well known in the art. Suitable materials for all of the parts would be apparent to those skilled in the art who are made familiar with this invention.
While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.
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A four-wheel pool cleaner ( 20 ) motivated by water flow to move along a pool surface, and having: a body ( 24 ); the four wheels rotatably mounted thereon and including two sets of two wheels ( 22 ) each, one wheel of each set on each side; a drive mechanism ( 36 ) in position to be moved by water flow and having a rotatable drive member ( 76 ); a drive train extending to the first wheel set ( 22 a, b ) and to the second wheel set ( 22 c, d ), to drive all four wheels. Preferred embodiments include: wheel-to-wheel drive links ( 88 ) along the side; a turbine ( 36 ) as drive mechanism; a pair of spaced wheelgears ( 32, 34 ), preferably integrally formed with the wheel, facilitating drive linkages and steering; a pair of end-to-end drive shafts ( 80, 82 ) joined by a coupler ( 84 c ), one shaft end ( 80 a ) being a ball joint allowing fore-and-aft movement of a drive-shaft distal end; a spring ( 102 ) and cam ( 100 ) for alternately moving that distal end between a driving position engaging one of the spaced wheelgears ( 32 ), and a steering position engaging the other of the spaced wheelgears ( 34 ); wheel treads ( 108 ) with radial fingers ( 110 ), some ( 110 a-c ) of longer length; and a segmented articulated skirt ( 56 ) to help enclose a plenum beneath the pool cleaner.
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SUMMARY
The present invention is directed to the manufacture of phosphoric acid by the wet process. The hemihydrate, or as it is sometimes called the semihydrate, process is employed to produce wet process phosphoric acid from phosphate rock and sulfuric acid. Phosphate rock and phosphoric acid are added to a first reaction vessel which contains a first slurry comprising calcium sulfate hemihydrate, monocalcium phosphate, sulfuric acid and phosphoric acid. The phosphate rock is substantially converted into monocalcium phosphate, phosphoric acid and calcium sulfate hemihydrate in the first reaction vessel. The soluble sulfate content of the first slurry in the first reaction vessel is maintained at a concentration of about +0.7% to about -4%. Sulfuric acid is added to the second reaction vessel which contains a second slurry comprising calcium sulfate hemihydrate, monocalcium phosphate, sulfuric acid and phosphoric acid. The sulfuric acid reacts with the phosphate rock and the monocalcium phosphate producing calcium sulfate hemihydrate and phosphoric acid. The soluble sulfate concentration of the second slurry is maitained at a value of about +0.7% to about +4.5%; provided that the soluble sulfate content of the second slurry is about +1.0% or greater when the soluble sulfate content of the first slurry is +0.7%. Sulfuric acid is added in amounts such that the sulfate content of the added acid and the sulfate content of the added rock is equivalent to about 90% to about 100% of the stoichiometric amount of sulfate required to react with calcium added in the phosphate rock to form calcium sulfate hemihydrate. In order to maintain the desired soluble sulfate concentration in the first reaction vessel and in the second reaction vessel, circulation between the two reaction vessels is initiated. A first portion of the first slurry from the first reaction vessel is circulated through a first conduit into the second reaction vessel, and a first portion of the second slurry from the second reaction vessel is circulated through a second conduit into a first reaction vessel. This circulation is continuous. In order to better disperse the added phosphate rock and the added sulfuric acid within the slurry of the first and the second reaction vessels respectively and to better disperse the incoming slurry with the slurry present in the given reaction vessel, a second portion of the first slurry and a second portion of the second slurry is circulated within the first and second reaction vessels respectively each through its own draft tube at a rate equal to at least 50% of the volume of the slurry in a given reaction vessel per minute. This inter- and intra- vessel circulation disperses the reactants within the slurry in the respective reaction vessels. A third portion of the second slurry is removed from the reaction system so as to separate the liquid and solid components from the said slurry.
BACKGROUND
The present invention is directed to a process for the production of phosphoric acid by the wet process. The invention is directed to the production of phosphoric acid by the calcium sulfate hemihydrate or simply the hemihydrate process. The present invention is directed to the process in which the control of reactant concentrations is improved, a concentrated phosphoric acid (about 30% to about 55% P 2 O 5 ) is produced, a reduction in sulfuric acid usage is realized and a substantial reduction in electrical energy consumption is also realized.
Phosphoric acid has been prepared by the wet proess for many years. The wet process involves the reaction of phosphatic solid materials, hereinafter termed phosphte rock, with sulfuric acid. A slurry comprising calcium sulfate, monocalcium phosphate, phosphoric acid and sulfuric acid is the usual reaction media. The names of the three processes for the production of phosphoric acid by the wet process are based on the by-product calcium sulfate produced; namely, the gypsum or dihydrate process, the hemihydrate process, and the anhydrite process. The type of by-product is dependent upon the temperature of the system and the P 2 O 5 concentration of the liquid phase of the slurry. Other factors such as fluorine concentration, alumina concentration, and sulfuric acid concentration play a less important role.
Gypsum, CaSO 4 . 2H 2 O, is the by-product formed when the wet process is run at a temperature of 90° C. or less and a P 2 O 5 concentration of about 30% in the liquid portion of the slurry. Increasing the temperature to about 80°-120° C. and the P 2 O 5 concentration to about 40% in the liquid phase will yield hemihydrate, CaSO 4 . 1/2H 2 O. Adjusting the temperature and the concentraions, for instance, to 75° C. and 40% P 2 O 5 results in a mixture of gypsum and hemihydrate which is very unstable. An unstable system such as this causes trouble during filtration due to the hardening or setting up of the gypsum-hemihydrate solid on the filter. Care must be exercised in maintaining the proper temperature and P 2 O 5 concentrations in the process being run in order to avoid such problems. CaSO 4 anhydrite is produced at temperatures of about 130° C. and P 2 O 5 concentrations greater than 30%. This latter process is most difficult to run due to severe corrosion at the higher temperatures and the instability of the anhydrite during processing.
Several problems are inherent in the production of phosphoric acids by the wet process. The degree to which these problems affect the three process will vary due to the different operating conditions employed. Several problems which affect recovery and/or processing of the phosphate rock during the production of phosphoric acid are discussed below.
Phosphate values can be lost during processing of phosphate rock by several different mechanisms. The first consists of the coating of the phosphate rock with calcium sulfate. This impeeds and/or inhibits the recovery of the phosphate values from the rock, hence resulting in very low yields. The second consists of substitution of calcium phosphate within the calcium sulfate lattice. The substituted phosphate values cannot be recovered by washing during the separation stage and hence pass to waste. This again results in poor recovery from the phosphate rock. The third problem involves the rapid precipitation or crystallization of many very small crystals of calcium sulfate. This lads to very poor filtration and filterability. The conditions which are employed in the three wet processes are listed and their effects on the recovery of P 2 O 5 from the rock.
As the P 2 O 5 concentration of the liquid portion of the reaction slurry increases (about 28% P 2 O 5 for the dihydrate process; about 40% P 2 O 5 for the hemihydrate process and about 50% P 2 O 5 for the anhydrite process), there is a great tendency to increase the substitution of calcium phosphate within the calcium sulfate crystal lattice. This results from the increase in HPO 4 -2 concentration in the liquid portion of the slurry. In the same manner the increase in the P 2 O 5 concentration of the liquid portion of the slurry tends to increase the viscosity of the reaction media and hence also tends to increase the amount of substitution of the phosphate within the calcium sulfate crystal structure due to reduced diffusion of the HPO 4 -2 species within the slurry. If, however, the temperature is increased, as occurs from going from the dihydrate process to the hemihydrate process, the viscosity of the reaction media is lower and hence the degree of substitution of the calcium phosphate within the calcium sulfate crystal structure is decreased. It must be recognized, however, that there are temperature limitations which must be observed for the process under consideration.
Increasing the sulfate concentration in the liquid phase of the slurry results in a decrease in the calcium ion concentration, thus tending to decrease the amount of substitution of calcium phosphate within the sulfate crystal lattice. However, care must be exercised not to increase the sulfate concentration to such an extent that the dissolution or the recovery of phosphate values from phosphate rock is impeeded by the coating of the rock with a layer of calcium sulfate. Excess sulfate concentration in the presence of high localized concentrations of calcium ions results in the precipitation of many very small crystals of calcium sulfate, resulting in a slurry difficult to filter. Thus the sulfate concentration can act both to increase the recovery of phosphate from the phosphate rock, or it can result in reduced recoveries of phosphate from the phosphate rock with attendant reduced filtration rates.
An increase in solids in the slurry will tend, in general, to increase crystal growth of the calcium sulfate formed by the reaction of calcium ions with sulfate ions. This will tend to result in larger crystals which will be more easily filterable and washable. In general, the variation of the solids content results only in very small variations in the degree of substitution of calcium phosphate within the calcium sulfate crystal lattice. In addition, it is imperative not to increase the solids to such an extent that the viscosity of the slurry is increased to such an extent that mixing becomes very difficult and localized supersaturation occurs.
Thorough mixing is very desirable whether running the dihydrate, the hemihydrate or the anhydrite process. Good mixing will decrease the localized high concentration of the reactants; namely, the calcium phosphate and the sulfuric acid. Decreasing such localized concentrations, results in a lowering of the substitution losses, a lowering of losses due to coating the rock and an improvement in the crystallization conditions.
Thus, it is observed that a change of one variable may favorably affect the recovery of P 2 O 5 from phosphate rock employing one of the wet process methods and it may be detrimental to the recovery of P 2 O 5 employing a different process. Therefore it is necessary to choose the combination of process variables which will result in the best recovery of P 2 O 5 from the phosphate rock along with acceptable filterability of the resulting slurry for the process at hand.
The recovery of the phosphate values from the phosphate rock can be greatly increased if the agitation or mixing is maintained at a high level. Previous workers in the field have directed their energy to achieve maximum mixing in the wet process. As a result of this activity, today there are one vessel and multi- vessel systems in use for the production of phosphoric acid by the wet process. The purpose is to achieve maximum mixing so as to increase the recovery of the phosphate values from the phosphate rock and to have the best environment for dissolution of the rock and for crystallization of CaSO 4 .
In a one vessel process, the phosphate rock and the sulfuric acid are added to the slurry in one tank. Agitators, in union with baffles, are used to circulate the slurry into which the reactants (phosphate rock and sulfuric acid) are added. To the extent that the localized concentration differences are minimized, the slurry has only one sulfate level. This is undesirable, since the phosphate rock should preferably be dissolved at a low sulfate concentration whereas crystallization should occur at a high sulfate concentration.
A multi-vessel system can be of two types. Two or more compartments or cells can be constructed within one vessel, the compartments being interconnected in series. The reactants are added separately, that is, in different compartments in order to increase the dispersion of said reactant in the slurry prior to reacting with the other reactant. At the last compartment, some slurry is removed from the system for recovery of phosphoric acid; the major portion of the slurry being recycled to the first compartment.
Multi-vessel processes involve the use of two or more vessels connected in series, the reactants are added to the slurry in separate vessels so as to more completely disperse one reactant in the slurry before it is contacted by the later added reactant(s). Again the system is arranged so that a portion of the slurry is recycled from a later reactor back to the first reactor.
The reaction between sulfuric acid and phosphate rock is exothermic. In order to control the temperature of the reaction system, provisions must be made to remove this excess heat. Previously this has been accomplished by (1) blowing air through the slurry or (2) pumping a portion of the slurry to a vessel under vacuum or (3) conducting the operation in a vessel under vacuum.
The use of air as a coolant is not too desirable because it is necessary to scrub large amounts of air exiting the system to remove pollutants, mainly fluorine in the form of hydrogen fluoride or silicon tetrafluoride. The equipment required is quite expensive. When a portion of the hot slurry is removed from the main body of the slurry, and subjected to vacuum, cooling occurs by the evaporation of water (U.S. Pat. No. 2,699,985). The cooled slurry is then added to the main body of the hot slurry and moderates the temperature of the process.
The method of conducting the reaction under vacuum has many desirable features. The cooled slurry is immediately dispersed within the hot slurry and temperature differentials within the slurry areminimized. The slurry is concentrated by the removal of water, and the desired temperature is easily maintained. The above described multi- compartment and multi- vessel systems improved on dispersing the reactants to some extent, however, greater dispersion of the reactants is desirable in order to improve the dispersion of the reactants in a one vessel reactor. Caldwell, U.S. Pat. No. 3,415,889 and 3,939,248 and Bergstrom, U.S. Pat. No. 3,666,143 and 3,917,457 developed a combination reactor-cooler which is fitted with a draft tube. The vessel was maintained under a vacuum while the slurry was circulated within a vessel. Using the draft tube with an agitator it is possible to circulate the slurry at such a flow rate that upwards of 200% of the volume of the slurry is circulated through the draft tube per minute, constantly renewing the surface of the slurry exposed to the vacuum. With this type of circulation, dispersion of the reactants is improved over the conventional one vessel system. In addition to better dispersion of the reactants, the slurry on exposure of the vacuum at the surface is cooled by evaporation of water. The temperature differential within the system is minimized by the rapid flow rate realized. The cooled slurry is immediately mixed with the hot slurry minimizing the localized cooling affect.
Lopker, U.S. Pat. No. 3,522,003 and 3,522,004 describes a two vessel system for the production of phosphoric acid from phosphate rock and sulfuric acid. These processes involve passing a slurry of phosphoric acid and calcium sulfate through a circuit which contains two vessels in series, at least one of which is under vacuum. The vacuum applied to one vessel cools the slurry by evaporation of water. The cooled slurry is then rapidly dispersed within the system minimizing cooling effects and preventing supersaturation of the calcium sulfate due to reduced temperatures. The levels of the slurries within the two vessels are vertically offset.
Sulfuric acid, phosphoric acid, phosphate rock or a mixture of phosphoric acid-phosphate rock can be added to the slurry in different vessels. The reactants are mixed in the vessel and are circulated from one vessel to another. In this way localized high concentrations of the added reactants are minimized. Good recovery of P 2 O 5 values from the rock are realized. Better filtration rates are also obtainable due to the retardation of the formation of excessive number of very small calcium sulfate crystals resulting from supersaturation.
Processes for the production of phosphoric acid by the hemihydrate process are well known in the art. A. V. Slack, in "Phosphoric Acid" Part One, Marcel Dekker, Inc., New York, 1968, describes hemihydrate process. The problems encountered are observed in filtering the hemihydrate slurry and the high degree of substitution of phosphate in the calcium sulfate lattice. Attempts to overcome the deficiency in filtration rate and poor P 2 O 5 recoveries while maintaining the production of phosphoric acid containing about 40% P 2 O 5 , resulted in the development of a hemihydrate-dihydrate system. U.S. Pat. No. 3,472,619 and 3,552,918 are representative of the systems of the systems employed.
These patents describe the preparation of phosphoric acid by the hemihydrate process, recovering said phosphoric acid from the solid CaSO 4 . 1/2 H 2 O, recrystallization of CaSO 4 . 1/2H 2 O to CaSO 4 . 2H 2 O, and the recovery of phosphoric acid liberated during the recrystallization of CaSO 4 . 2H 2 O. Apparently, the best of both processes is achieved. High concentration, about 40% P 2 O 5 acid is recovered while low losses in the filter cake are observed as the result of the recrystallization of the CaSo 4 . 1/2 H 2 O.
Fitch (U.S. Pat. No. 3,552,918) describes a process for the production of concentrated phosphoric acid and gypsum including the acidulation of phosphate rock in a first zone in which the resulting slurry contains from about 1% (-2.45% SO 4 = ) to about 4.5% (-11% SO 4 = ) excess calcium. The slurry produced in the first zone is then transferred to a second zone in which an excess of sulfuric acid is present such that from about 3% to about 6% excess sulfuric acid is present in the slurry. Hemihydrate initially produced is converted to gypsum.
Long (U.S. Pat. No. 3,453,076), Peet (U.S. Pat. No. 2,885,264) and Robinson, (U.S. Pat. No. 3,418,077) described processes for the production of phosphoric acid by the hemihydrate process. No additional recrystallization of the CaSO 4 . 1/2H 2 O is required in these processes. In the Robinson process phosphoric acid containing from about 40% to about 55% P 2 O 5 by weight is produced. This process which comprises in a first stage reacting in the presence of excess calcium ions, phosphate rock with at least nine parts by weight of phosphoric acid for each part of calcium added, said phosphoric acid containing at least 37% by weight P 2 O 5 and 1% to 3% by weight dissolved sulfate whereby the phosphate rock is converted into a slurry comprising monocalcium phosphate, phosphoric acid, and calcium sulfate, the percentage of calcium ion precipitated as calcium sulfate being 10 to 60%, preferably 20-50% by weight of total calcium fed, in a second stage reacting the slurry from the first stage with sulfuric acid whereby phosphoric acid containing at least 40% P 2 O 5 by weight and calcium sulfate hemihydrate is formed, the sulfuric acid being used in an amount 0.5 to 2.0% by weight in excess of that required to convert the calcium content of the phosphate rock fed to the first stage into calcium sulfate, and in the third stage separating the phosphoric acid from the calcium sulfate and washing the crystals. The temperature of the first and second stages being in the range from 80 to 115° C., preferably from 90-110° C.
BRIEF DESCRIPTION OF THE DRAWINGS
In FIG. I, a schematic of the preferred embodiment of the process is shown;
In FIG. II, a schematic of another embodiment of the process is shown; and
In FIG. III, a schematic of the inter- and intra- vessel flow patterns are shown.
DETAILED DESCRIPTION
This invention is directed to a process for the production of phosphoric acid by the calcium sulfate hemihydrate process.
Phosphate rock, either calcined or uncalcined, and phosphoric acid are added to a first slurry of, calcium sulfate hemihydrate, monocalcium phosphate, phosphoric acid and sulfuric acid. Preferably, the phosphate rock is slurried in the phosphoric acid prior to the addition to the first slurry. Phosphate rock, about 95% of +100 mesh, containing at least 32% P 2 O 5 is the preferred source of phosphate for the process. Ground or unground rock can be used. However, phosphate rock of 95% of -200 mesh can be used. Rock containing less than 32% P 2 O 5 is acceptable, and can be employed in this process. High alumina phosphate pebble may also be used. The phosphate rock is slurried in phosphoric acid that contains from about 13% to about 47% P 2 O 5 . Phosphoric acid, recycled from the separation section, containing from about 13% to about 47% P 2 O 5 is usually used in the process. However, phosphoric acid from other sources, such as other phosphate plants, merchant grade acid may be used. When the phosphoric acid is recycled from the separation section it will usually contain from about 0.5% to about 3.5% sulfuric acid by weight.
The temperature of the phosphate rock-phosphoric acid mixture is maintained at about 50° C. to about 100° C., preferably from about 90° C. to about 100° C. The resulting mixture is from about 30% to about 40% solids by weight, about 33% being preferred. A defoamer is added if and when required. Various antifoam agents can be used, including tall oil fatty acids, oleic acid, sulfated tall oil fatty acids, sulfated oleic acid, silicones and reaction products of amines and carboxylic acids.
The phosphate rock-phosphoric acid mixture is added to a first slurry of, calcium sulfate hemihydrate, phosphoric acid monocalcium phosphate and sulfuric acid in a first reaction vessel. The phosphate rock and phosphoric acid may be added separately to the first slurry in the first reaction vessel. The phosphate rock-phosphoric acid mixture on being added to the first slurry in the first reaction vessel is immediately dispersed within the first slurry. A first portion of the first slurry is transferred to a second reaction vessel.
The first reaction vessel is fitted with a draft tube and an agitator. (The agitator consists of a shaft fitted with a propeller at the bottom thereof). The agitator is so located with respect to the draft tube that on activation of the agitator, a second portion of the first slurry is drawn from the bottom of the draft tube up through the draft tube and out the top of the draft tube. On exiting the draft tube said slurry passes in a downward direction in the space between the draft tube and the walls of the first reaction vessel. The direction of circulation through the draft may be reversed and is not critical. Circulation is thus established within the first reaction vessel. The rate at which said slurry is circulated is at least equal to about 50% of the volume of the slurry in the first reaction vessel per minute, preferably from about 50% to about 150% and most preferably about 100%. This circulation thoroughly disperses the phosphate rock-phosphoric acid mixture with the first slurry. The first slurry contains sulfuric acid which reacts exothermically with the phosphate rock being added. Dilution of the sulfuric acid also results in the evolution of heat. These exothermic reactions supply the heat required to maintain the temperature of the slurry in the first reaction vessel between about 66° C. to about 113° C. The soluble sulfate content of the of first slurry is maintained at about +0.7% to about -4%. [As measured, soluble sulfate values can be either positive or negative. Soluble sulfate values include not only the sulfuric acid present in the liquid component of the slurry but also the soluble calcium sulfate therepresent. Negative soluble sulfate values indicate that an excess of calcium ions are present in the solution as is usually observed in the phosphate rock-phosphoric acid mixture. Positive soluble sulfate values indicate that excess sulfate ions are present. A value of 0.0% indicates that the sulfate ions and the calcium ions are equivalent stoichiometrically within the limits of the analysis.] The residence time of the solids in the first reaction vesselis from about 2.0 hours to about 5.0 hours, preferably from about 2.5 hours to about 4.5 hours.
A first portion of the first slurry is transferred through a first conduit into a second reaction vessel. The second reaction vessel which can be subjected to a vacuum, is fitted with a draft tube, an agitator and a sulfuric acid inlet. The agitator consists of a shaft fitted with a propeller at the bottom thereof. The shaft and agitator are so located with respect to the draft tube that on actuation of the agitator a second portion of the second slurry is caused to flow from the bottom of the draft tube up through the draft tube and out the top of the draft tube. On exiting the draft tube, said second portion of the second slurry flows in a downward directionin a space between the draft tube and the inside walls of the second reaction vessel. The direction of the circulation can be reversed and is not critical. The rate at which the slurry is circulated is at least equal to about 50% of the volume of the slurry in the vessel per minute, preferably from about 50% to about 150% of the volume and most preferably about 100% of the volume. Sulfuric acid, preferably about 98%, is added through the sulfuric acid inlet into the second slurry either as is or mixed with phosphoric acid. The first portion of the first slurry is also added into the second slurry. A crystal modifier, usually a derivative of an organic sulfonic acid, can be added to the slurry in the second reaction vessel. The organic sulfonic acid can be an alkyl-, aryl- or an alkylaryl- sulfonic acid or a sulfated derivative of an carboxylic acid. For example, tetradecyl sulfonic acid, benzene-sulfonic acid, isooctylbenzene sulfonic acid and sulfated oleic acid may be used as crystal modifiers in this process. The crystal modifier is added for the purpose of increasing the growth of the hemihydrate crystals formed in the system. The flow of the second slurry within the second reaction vessel thoroughly disperses the first portion of the first slurry, the sulfuric acid and the crystal modifier within the second slurry. (The location of the sulfuric acid inlet in the second reaction vessel is not critical. It may be at the top, the middle, the bottom or at intermediate points of the second reaction vessel. The sulfuric acid conduit attached to the sulfuric acid inlet may enter the second reaction vessel from the top, the bottom, or points intermediate therein, the exact point of entrance into the vessel is not critical.) Phosphoric acid, if needed, can be added to the second slurry within the second reaction vessel. The surface of the second slurry in the second reaction vessel is exposed to a pressure of between about 2 to about 29 inches of mercury absolute, preferably from about 3 to about 20 inches mercury absolute. Water and volatile components added to or produced in both the first and second slurries can be removed from the second slurry causing a reduction in the temperature of the second slurry from which the volatiles are removed. The cooled second slurry is thoroughly mixed so that temperature differentials are minimized within the total volume of the second slurry. With this evaporative cooling, the temperature of the second slurry is maintained between about 66° C. to about 113° C. preferably from 80° C. to about 105° C. [The process can be run while maintaining both the first and second reaction vessels at atmospheric pressure.] Sulfuric acid which is added to the second slurry in the second reaction vessel through the sulfuric acid inlet can be from about 89% to 99% H 2 SO 4 or more, preferably about 98% H 2 SO 4 .
It has been determined that the total sulfate value added to the system is the sum of the sulfate values in sulfuric acid added plus the sulfate values added in the rock and this total is only about 90% to 100% of the stoichiometric amount of sulfate needed to convert the calcium added in the rock fed to the first reaction vessel into calcium sulfate hemihydrate. See Table 1 for the compilation of sulfuric acid usage. Listed are the tons per day (TPD) of phosphate rock fed, % CaO in the rock, % SO 4 = in the rock, CaO fed (TPD), stoichiometric sulfate for the calcium in the rock (TPD), sulfate in sulfuric acid fed to the unit (TPD), sulfate equivalent in the rock (TPD), the total sulfate used (TPD), and total sulfate used as a fraction of the stoichiometric amount of sulfate required for the calcium in the rock. The soluble sulfate content as measured in the second slurry should be from about +0.7% to about +4.5%, preferably from about 2.5% to about 3.5%; provided that when the soluble sulfate content of the first slurry is about +0.7% then the soluble sulfate content of the second slurry must be +1.0% or more. The specific gravity of the slurry in the second reaction vessel is about 1.80 ± 0.2 g/cc. The specific gravity of the liquid portion of the slurry is about 1.56 ± 0.20 g/cc. The liquid gravity corresponds to a phosphoric acid which contains about 42%± 12% P 2 O 5 . Residence time of the solids in the second reaction vessel is from about 0.6 hour to about
TABLE 1__________________________________________________________________________ Sulfate Total Present Sulfate SO.sub.4.sup.= Stoichiometric in 100% Equival- Total used as Sulfate (SO.sub.4.sup.=) H.sub.2 SO.sub.4 Fed ent in Sulfate a fraction ofRock Fed, CaO in Rock, SO.sub.4 in Rock CaO Fed, for CaO in Rock to Unit, Rock, Used, StoichiometricTPD % % TPD TPD TPD TPD TPD Amount__________________________________________________________________________1209.5 44.90 0.65 543.07 930.97 844.4 7.86 852.26 0.9151383.1 45.97 0.65 635.81 1089.4 1052.2 8.99 1061.2 0.9741381.6 46.76 0.65 646.04 1107.5 1024.7 8.98 1033.7 0.9331172.2 46.81 0.65 548.71 940.64 844.3 7.62 851.9 0.9061110.9 46.89 0.65 520.90 892.97 804.6 7.22 811.82 0.909__________________________________________________________________________
2.0 hours, preferably from about 0.7 hour to about 1.6 hours.
The excellent mixing obtained with this system is achieved using approximately 1/10 of the horsepower required for a comparable wet process phosphoric acid plant such as a Dorr-Oliver or a Prayon Plant.
A first portion of the second slurry flows from the second reaction vessel back to the first reaction vessel through a second conduit and is thoroughly dispersed within the first slurry. It is the flow of the second slurry to the first slurry which aids in controlling the temperature of the first slurry and adds sulfate values (sulfuric acid) and phosphoric acid values to the first slurry in order to dissolve the rock. Additional sulfate values are added to the first slurry in the first reaction vessel with the recycled phosphoric acid. Circulation between vessels and within vessel minimizes localized concentration of reactants of hot slurry and of cooled slurry thus resulting in a more easily controlled process than previously observed. A third portion of the second slurry is removed from the second reaction vessel and is transferred through a conduit to a reservoir. The third portion of the second slurry, on a weight basis, is approximately equal to the phosphate rock, the phosphoric acid, and the sulfuric acid added in the first and second reaction vessels respectively minus the volatiles (on a weight basis) removed from the second reaction vessel which can be subject to a vacuum. The third portion of the second slurry is constantly stirred in the third vessel to prevent separation of the solids from the liquid and is maintained at about 66° C. to about 113° C., preferably from about 70° C. to about 100° C. The residence time in the third vessel is relatively short, being from about 0.5 hour to about 1.5 hours, preferably from about 0.60 hour to about 1.25 hours. The soluble sulfate concentration of the slurry in the third vessel may change somewhat due to continued reaction of the soluble sulfate values with any calcium values therepresent. Sulfuric acid may be added to the third vessel to adjust the sulfate values.
From the third vessel, the slurry is transferred to the separation section in which the slurry is separated into its solid and liquid components using apparatus well known in the art.
Slurry samples are removed from the system at several locations. A sample port is placed in the first conduit at a location between the first and second vessels, the distance between the first and the second reaction vessel is not critical. Slurry removed from this sample port represents the first slurry. A sample port is located in the conduit between the second reaction vessel and the reservoir to which the third portion of the second slurry is pumped. The location of this sample port in terms of distance between the second reaction vessel and the reservoir is not critical. Slurry samples obtained from these two ports can be analyzed for soluble sulfate concentrations, specific gravities, and crystal size. The flow rates of the reactants and of the slurries are adjusted in accordance with the analytical values obtained in order to maintain the desired sulfate levels within the reaction system. It is to be understood that the system described can be run on a continuous basis, the reactants are continuously added and the third portion of the second slurry is continuously removed from the system prior to separation into phosphoric acid and calcium sulfate hemihydrate.
In FIG. I is shown a schematic of the process. Phosphoric acid at about 70° C. is added through conduit 6 and phosphate rock which is added through conduit 8 are slurried in vessel 2 which is fitted with an agitator 4. Defoamer can be added as needed through conduit 10. The temperature of slurry 11 so formed is about 92° C. and the solids content is about 30% to about 40% by weight. Slurry 11 is transferred through conduit 12 to vessel 16. Vessel 16 is fitted with an agitator (shaft 18 and propeller 21 attached to the bottom thereof), and a draft tube 20 which is secured to the inside wall of vessel 16 by braces (not shown). Slurry 11 flows into slurry 22 which is composed of calcium sulfate hemihydrate, monocalcium phosphate, phosphoric acid, and sulfuric acid. The propeller 21 of the agitator is so positioned with respect to the location of the draft tube 20 that on actuation of the shaft 18 and propeller 21 by a motor (not shown), a slurry 22 in vessel 16 will flow from the bottom portion of the draft tube 20 up through the draft tube. On exiting the top of the draft tube, slurry 22 will flow downwardly in the space between the draft tube 20 and the inside walls of vessel 16. A first portion of slurry 33 is transferred from vessel 28 through conduit 38 to vessel 16. The flow created within vessel 16 thoroughly mixes slurry 11 and slurry 33 within slurry 22. Slurry 22 is then transferred to vessel 28 through conduits 24 using pump 25. Vessel 28 may be vertically offset from vessel 16 or it may be on the same level as vessel 16. Samples for analysis of the first slurry are removed from sample port 25a. Slurry 22 is at a temperature of about 66° C. to about 113° C., and has a soluble sulfate value of about +0.7 to about -4%.
On entering vessel 28 which is equipped with an agitator (shaft 30 and propeller 31 attached to the bottom thereof), a draft tube 32 and a sulfuric acid inlet 34, slurry 22 is dispersed into slurry 33. Draft tube 32 is secured to the inside wall of vessel 28 by braces (not shown). Sulfuric acid is added from the sulfuric acid inlet 34 and is also thoroughly dispersed into slurry 33. Crystal modifier may be added to vessel 28 through an inlet not shown. Activation of the agitator (shaft 30 and propeller 31) by means of a motor (not shown) causes a flow of slurry 33 from the bottom of the draft tube 32 up through the draft tube and out the top portion of said draft tube. On exiting the top of the draft tube 32, the slurry flows downwardly in the space between the draft tube 32 and the inside walls of vessel 28. A circulation established within vessel 28 disperses slurry 22 and sulfuric acid into slurry 33, constantly renewing surface 36. Vessel 28 is subjected to a pressure of about 2 inches of mercury to about 29 inches of mercury absolute. Water is evaporated from the hot slurry thus cooling the slurry. In addition to water, other volatile materials produced by the reaction of sulfuric acid and phosphate rock are also removed. These materials include HF, SiF 4 , H 2 S, SO 2 , CO 2 and others. Because of the internal circulation of the slurry within vessel 28 temperature gradients are minimized. Slurry 33 maintained at a temperature of about 66° C. to about 113° C., preferably from about 80° C., to about 105° C., and having a sulfate content of about +0.7 to about +4.5% is recirculated back to vessel 16 through conduit 38. Slurry 33 is efficiently dispersed within slurry 22 in vessel 16 by means of the internal circulation within vessel 16. Thus a system has been developed in which both inter and intra-vessel circulation occur so as to better disperse the reactants being added to the slurries and to reduce temperature gradients within the vessels due to heating and cooling.
A portion of slurry 33 about equal to the amount of reactants added (phosphoric acid, phosphate rock and sulfuric acid), minus the amount of water and volatiles removed from the system is removed from vessel 28 through conduit 40. Samples for analysis of the second slurry are removed from sample port 41 located on conduit 40. The slurry is pumped (pump not shown) to reservoir 44 from which it flows to vessel 48 through conduit 46. Agitator 50 maintains the slurry in a dispersed condition in vessel 48. The slurry is pumped (pump not shown) from vessel 48 through conduit 52 to the separation section (not shown).
Reactants are continuously added to vessel 16 and 28 with water and volatiles and the product slurry constantly being withdrawn from vessel 28. In case of a separation apparatus breakdown the system can be placed on recycle. No reactants are added to the system. Intra-vessel circulation would continue and inter vessel circulation would be discontinued.
It is to be recognized that the elevation of vessels 2, 16, 28, 44 and 48 with respect to each other may be varied without affecting the instant invention. Likewise, the conduits connecting vessels 2, 16, 28, 44 and 48 may be rearranged, additional conduits added and/or existing conduits deleted without affecting the instant invention. For example, slurry 22 passing from vessel 16 to vessel 28 may be introduced into the top part of vessel 28 rather than the bottom part without affecting the instant invention.
Another embodiment of the claimed invention is shown in FIG. II. Instead of adding the reactants phosphoric acid, phosphate rock and if necessary, the defoamer to a preslurry vessel 2 as shown in FIG. I, the reactants are added directly to the first slurry 22 in vessel 16. The phosphoric acid is added through conduit 7 and the phosphate rock is added through conduit 9. The reactants are added in amounts such that the direct combination of the two results in a slurry containing between about 30% to about 40% solids by weight and an initial concentration of about 13% to about 47% P 2 O 5 in the liquid portion of the slurry. Defoamer is added through conduit 13, if, and when needed. Once the reactants are dispersed in the first slurry 22, the parameters such as temperatures, pressures, concentrations, and flows are the same as described above for the more preferred embodiment.
FIG. III shows the flow or circulation patterns of the slurry in the system of the instant invention. Slurry 60 flows from vessel 61 through conduit 62 into vessel 63. Vessel 63 is fitted with a draft tube 64 and an agitator 65. Slurry 65a flows within vessel 63 as shown by dotted lines 66. Conduits 67, 68, and 69 are used to circulate slurries, 65a and 72a between vessel 63 and 70 respectively. Slurry 65a flows through conduits 67 and 68 into vessel 70, said vessel being fitted with a draft tube 71 and an agitator 72 and a sulfuric acid inlet 74 for sulfuric acid introduction into slurry 72a. Slurry 72a flows within vessel 70 as shown by dotted lines 73. It should be recognized that the direction of flows shown by dotted lines 66 and 73 can be reversed without disrupting the process. A flow or circulation pattern is established between vessels 63 and 70 through conduits 67, 68 and 69 respectively. Of equal importance are the flow patterns established within vessel 63 and within vessel 70. The flow pattern of slurry within vessel superimposed upon the flow patterns of slurry between vessels results not only in excellent dispersion of reactants within the slurry but also maintenance of very low temperature differentials within a given vessel.
EXAMPLE
Vessels 16 and 28 and the accompanying connective means such as conduits, pumps, etc. of FIG. I are filled with a slurry consisting of calcium sulfate hemihydrate, monocalcium phosphate, phosphoric acid and sulfuric acid. The weight percent of the solids in the slurry is about 31%, the specific gravity of the slurry in vessel 28 is about 1.80 ± 0.07 g/cc and the specific gravity of the liquid portion of the slurry is about 1.53 ± 0.06 g/cc. P 2 O 5 concentration of the liquid portion of the slurry is about 42% by weight. The temperature of the slurry in vessel 16 is between about 88°-102° C. preferably between 92° C. and 105° C., whereas the temperature in vessel 28 is between 88° and 105° C., preferably between 92° C. and 105° C. Soluble sulfate concentration in vessel 16 is from about +0.7 to about -4% and the soluble sulfate concentration in vessel 28 is from about 0.7 % to about +4.5%.
A mixture of phosphate rock (typical analysis shown in Table 2) of a size distribution shown in Table 3, and phosphoric acid is prepared by adding phosphate rock to phosphoric acid in the ratio of about 1647 pounds of phosphate rock (about 31.2 P 2 O 5 and 45.6 CaO) to about 3700 pounds of phosphoric acid (about 32% P 2 O 5 ). The temperature of the mixture is about 90° C. A tall oil sulfonic acid defoaming agent is added as needed to reduce the foam caused by partial dissolution of the phosphate rock in phosphoric acid.
This phosphate rock-phosphoric acid mixture is added to the first slurry in vessel 16 at the rate of about 380 gpm (about 5350 pounds per minute). The incoming mixture is thoroughly mixed with the first slurry and a first portion of the second slurry from the second reaction vessel. Intra vessel mixing is accomplished by means of the draft tube and the agitator. The first slurry is pumped from the first reaction vessel 16 to the second reaction vessel 28 at the rate of about 1640 gallon per minute. The first slurry is thoroughly mixed with the second slurry and 98% sulfuric acid which is added to the second reaction vessel at about 87 gpm. An organic sulfonic acid derivative can be added to the second reaction vessel 28. This material is added to promote the growth of the hemihydrate crystals. The first slurry, the sulfuric acid and the crystal modifier are thoroughly dispersed into the second slurry in the second reaction vessel 28. The second slurry flows at the rate of aboue 1280 gallons per minute from vessel 28 into vessel 16 where it is thoroughly mixed with the first slurry.
About 45 gpm of water and volatile materials (HF, SiF 4 , H 2 S, CO 2 etc.) is vaporized from the second slurry in vessel 28. Vessel 28 is maintained under a vacuum of about 15 inches of mercury absolute. Approximately 400 gpm of slurry is withdrawn from the second reaction vessel and flows to vessel 48, the separator feed tank. Thus about 445 gpm of material (vaporized material and the slurry to the separator feed tank) is removed from the system. The removed slurry is then passed to the separation section where the solid and liquid portions of the slurry are separated.
At these rates, the plant will produce about 350 tons per day of P 2 O 5 of 35-44% P 2 O 5 phosphoric acid. The recovery data is summarized below.
______________________________________TOTAL LOSS IN FILTER CAKE % of P.sub.2 O.sub.5 fed in rock______________________________________Citrate insoluble (CI) 0.76Citrate soluble (CS) 4.64Water soluble (WS) 2.34Total loss 7.74Total Recovery 92.26______________________________________
A typical analysis of the phosphoric acid produced by this process is shown in Table 4. The total residence time, from entering vessel 16 to exiting vessel 48, is calculated at 7.9 hours. The volume of vessel 16 is about 120,000 gallons, the volume of vessel 28 is about 40,000 gallons to normal liquid level.
Phosphate rock is present in the first and in the second slurries in the first and second reaction vessels respectively. The amount present is quite small and will vary considerably. The value for the "Citrate Insoluble" loss of the filter cake is a rough measure of undissolved and unreacted phosphate rock.
Table 2______________________________________Typical Phosphate Rock AnalysisCompound % By Weight______________________________________P.sub.2 O.sub.5 31.2CaO 45.6Fe.sub.2 O.sub.3 1.4Al.sub.2 O.sub.3 1.2MgO 0.4SiO.sub.2 8.7F 3.7SO.sub.3 0.9CO.sub.2 3.6Organic 1.8H.sub.2 O 1.1Na.sub.2 O, K.sub.2 O 0.4______________________________________
Table 3______________________________________Typical Phosphate Rock Screen Analysis CummulativeMesh Percent______________________________________+14 0.4+24 2.6+28 9.3+35 26.6+48 64.1+65 86.4+100 97.7-100 2.3______________________________________
Table 4______________________________________Typical Phosphoric Acid AnalysisP.sub.2 O.sub.5 37.95SO.sub.4.sup.= 1.72CaO 1.04F.sup.- 1.27MgO 0.46Fe.sub.2 O.sub.3 0.97A1.sub.2 O.sub.3 0.91______________________________________
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Phosphate rock and sulfuric acid are reacted under conditions which result in the formation calcium sulfate hemihydrate and phosphoric acid of about 30% to about 55% P 2 O 5 . A two vessel reaction system is used in which the reaction slurry undergoes inter- and intra- vessel circulation. This results in excellent dispersion of reactants and minimization of temperature and concentration gradients throughout the slurry.
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TECHNICAL FIELD
[0001] The present invention relates to a method for protecting a copper surface, particularly in the manufacturing of electronic circuit boards.
BACKGROUND OF THE INVENTION
[0002] The use of tin base solder alloys is common in electronic applications, particularly in the manufacturing of printed circuit boards (PCB), for assembly of components onto the boards, providing mechanical and electrical connection. These tin solder alloys are useful in joining integrated circuit chips to chip carriers and substrates, joining chip carriers to substrates, and joining circuitization lands and pads in multilayer printed circuit boards.
[0003] In the manufacturing of a microelectronic package, it is common practice to attach a component onto a printed circuit board or the like, for example by surface mounting utilizing a solder connection. For this purpose, the board features a circuit trace including a pad that constitutes a first surface for the connection; similarly, the component includes a second surface, for example a contact.
[0004] The interconnection method comprises the steps of applying a solder alloy on the Cu substrate, typically onto the pad included in the printed circuit board.
[0005] The electronic components to be joined with the board are then brought into contact with the solder layer. The solder alloy is heated to cause the solder alloy to melt and reflow; heating may be by vapour phase reflow, infrared reflow, laser reflow, or the like. Upon cooling, the solder alloy resolidifies and bonds to the surfaces to complete the connection. The solder connection not only physically attaches the component to the board, but also electrically connects the trace on the board and the contact of the component to conduct electrical current to and from the component for processing.
[0006] The oxidation of a copper surface exposed to the air is a well known problem, not only in the manufacturing of electronic modules. The oxidation of copper pads of a PCB affects the solderability of the copper surface with the tin based alloy and this can cause problems in the assembly of the electronic module, particularly when the PCB is exposed to air for a prolonged period before being processed. For this reason the PCB is usually treated with chemical solutions which protect the copper from oxidation.
[0007] One of the known techniques used for protecting copper surfaces from corrosion, especially in the field of electronic circuit boards, is the Organic Solderability Preservative coating as described for example in “Corrosion Protection of Copper Using Organic Solderability Preservatives” by I. Artaki et al. Circuit World Vol., 19 No. 3, 1993, pages 40-45. These organic coatings are usually based on azole or its derivatives. Azoles react with metallic copper forming a film which helps to inhibit copper oxidation without compromising the solderability of the copper surface. U.S. Pat. No. 3,295,917 discloses inhibiting copper corrosion by coating with benzotriazole. U.S. Pat. No. 3,933,531 discloses a preservative treatment with 2-alkyl imidazoles. U.S. Pat. No. 4,373,656 discloses a method for preserving a copper surface by immersing in imidazole.
[0008] As mentioned above, it is known to bathe the PCB in a solution containing BenzoTriAzole (BTA). A commercially available BTA based product is, for example, Entek56 produced by Enthone-Omi Inc.
[0009] However the prior art treatments are not always satisfactory, especially during the soldering process when the PCB undergoes high temperature.
[0010] Therefore an improved treatment for the copper surface would be highly desirable.
[0011] It is an object of the present invention to provide a technique which alleviates the above drawbacks.
SUMMARY OF THE INVENTION
[0012] According to the present invention we provide a solution for preserving a copper surface of an electronic module, the solution containing at least one compound selected from the family of the azoles, characterized in that it further comprises a zinc salt.
[0013] Further, according to the present invention we provide a method for protecting a copper surface of an electronic module comprising the step of immersing the copper surface in a solution containing at least one compound selected from the family of the azoles, characterized in that it further comprises a zinc salt.
[0014] Also, according to the present invention, we provide a method for soldering a metallic component on a copper surface with a tin base alloy, the method comprising the step of pretreating the copper surface with a solution as described in claim 1 .
[0015] The addition of the zinc (Zn) salts in the pretreatment solution gives substantial improvements to the copper (Cu) surface characteristics. The Cu surface oxidation decreased, both during soldering and the exposure to atmosphere; the Cu surface wettability is substantially improved, even after long time at relatively high temperature; and the adhesion of the tin (Sn) solder alloy is increased.
[0016] The decrease of oxidation of the Cu surface with time and temperature could be interesting and appreciated in many other applications, in fields different from the electronics industry, e.g. the treatment of copper roofs and panels in the building industry for maintaining the original copper aspect; other possible applications cover sanitary or hydraulic uses for protecting copper pipes.
[0017] The present invention takes advantage of the fact that Zn forms a complex with BTA, in presence of Cu increasing the stability of layer adsorbed on the surface and giving to the interface the advantages described above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] According to the present invention the Zn salt is added to a treatment solution containing an organic substance for inhibiting copper oxidation (e.g. benzotriazole or benzimidazole) and adequately complexed. The pH of the solution can be varied in the range 5-8. According to a preferred embodiment a 7.5 pH has been reached by the addition of ammonia. The quantity of the components should be in the following ranges:
Zn salt 0.1-1 mol ETA 0.001-0.5 mol (molar ratio) amine/zinc salt 1-2 (molar ratio) organic acid/zinc salt 1-3 pH 5-8
[0019] According to a preferred embodiment the bath solution is prepared dissolving a Zn salt in water; then an amine and an organic acid are provided to complex the Zn salt and buffer the bath solution. The solution is then stabilized at 7.5 PH by the addition of ammonia. Finally BTA is added and the solution is stirred and heated. More specifically, as an example of a preferred embodiment, 45 g of zinc acetate Zn(CH 3 COO) 2 2H 2 O, is dissolved in 200 ml of water; the complexants used are 50 ml of TriEthanolAmine (TEA) and 25 ml of acetic acid CH 3 COOH. Then the BTA is added in the quantity of 0.1 g and the volume of the solution is increased to 500 ml by addition of water. The addition of BTA can be done by directly adding 0.1 g to the solution, add the water to reach the volume of 500ml and then stirring and heating (T=40-70° C.) until a limpid solution is obtained.
[0020] Alternatively the BTA can be previously dissolved in an alcoholic solution (5 g of BTA in 50 ml of ethanol) and then added to the above solution (1 ml of the alcoholic solution). In this way no heating is required and only a few minutes of stirring will give a limpid solution.
[0021] In order to increase the wettability of the copper surface to be treated with the above solution, a surfactant can be added. This is particularly useful for facilitating the wettability of “via holes” in a Printed Circuit Board. According to a preferred embodiment a commercially available product SANDOPAN ECO produced by CLARIANT has been used, but any other similar product can be used (e.g. TRITON DF16 produced by ROHM & HAAS).
[0022] By immersing a copper surface (e.g. a Printed Circuit Board with copper circuits) in the above described solution, Zn is deposited on the copper surface.
[0023] A copper surface treated with the preservative solution according to a preferred embodiment of the present invention has been compared with another surface treated with a prior art solution containing 0.2 g/l of BTA.
[0024] Then the copper surface specimens have been heated at 240° C. for 2 minutes and left exposed to the atmosphere at room temperature for 24 hours for simulating the actual conditions at which the PCB are exposed during the manufacturing processing (soldering cycles and storage).
[0025] We will refer to the solution according to a preferred embodiment of the present invention as ZAB (from Zn Added BTA) as opposed to simply BTA which is the prior art solution.
[0026] Laboratory tests have been performed using ESCA-XPS measurements with monochromatic Al Kalfa X-ray source (1486.67 eV); pass energy 29.35 eV, sputtering rate 2 nm/min, detector/sample angle 45.
[0027] The results obtained are as follows:
C N O Cu Zn ZAB treatment: surface 31 6 34 19 10 1.7 nm sputt. 5 3 12 71 9 5.1 nm sputt. 3 2 3 89 3 10 nm sputt. 2 2 — 95 1 BTA treatment: surface 36 7 32 25 1.7 nm sputt. 7 4 25 64 5.1 nm sputt. 9 4 9 78 10 nm sputt. — — — 100
[0028] From the tables above it is clear that the ZAB treatment caused a decrease of oxidation when the copper surface has been heated and exposed to air, which is the most critical condition for a Printed Circuit Board. Looking at the percentage of Oxygen at 1.7 nm depth it is half than in the case of prior art BTA treatment; at 5.1 nm it is one third.
[0029] As mentioned above, another advantage of using the pretreatment according to the present invention is the improvement of the copper surface wettability with a tin (Sn) solder alloy. Wettability is an indication of how completely and quickly the molten solder can cover a solid surface. Wettability tests by measuring the stripping force with a wetting balance have been performed. Two copper surfaces, one treated with the BTA prior art solution, the other with the ZAB solution described above, have been immersed in a liquid eutectic Sn—Pb alloy at 215 C. and fluxed with a suitable solution (Kester 450 33% in IPA). Then they have been heated at 240° C. for 2 minutes and kept exposed to the atmosphere for 24 hours. The results were as follows:
[0030] ZAB 3.4 mN after 2.3 sec 6.9 mN after 5.1 sec
[0031] BTA 1.1 mN after 3 sec 4.7 mN after 8.5 sec
[0032] The test shows, for the surface pretreated with the ZAB solution described above, according to a preferred embodiment of the present invention, a better wettability in a shorter time of immersion.
[0033] Another advantage of the pretreatment solution of the present invention is the increased adhesion of a solder alloy to the copper surface. This is particularly useful in case a Pb free alloy is to be used. Tin-lead (Sn—Pb) alloys have been used for most electronic soldering operations. These alloys have been selected because of their mechanical strength, low relative cost, electrical conductivity and excellent wetting characteristics. In addition, Sn—Pb alloys provide a low melting temperature, which is important in electronic applications because many components and printed circuit boards use materials that are easily damaged by exposure to high temperature during manufacture or assembly. However, lead has been recognized as a health hazard, being toxic for workers and for the environment; recently governments have begun to urge the electronic industry to find alternatives to lead in order to reduce electronic industry worker lead exposure and reduce the amount of lead waste going back into the environment. Lead presence in the soldering alloys is particularly critical in the case of application for manufacturing the most recent generation of C-MOS; in fact the details are so thin in this kind of board, that the emission of α particles from the emitting radioisotope present in the lead can provoke serious problems for the device. Lead-free solder alloys known in the art, however present some problems. They exhibit poor soldering and metallurgical properties, that is small peel strength and low creep resistance. Particularly, they have shown poor mechanical properties at temperatures of the type typically encountered by microelectronic packages during use.
[0034] For the above reason the increased adhesion provided by the pretreatment solution described by the present invention can be very useful particularly in the case of Pb free alloy, e.g. tin-bismuth (Sn—Bi) alloy.
[0035] Using a free wheeling rotary test fixture, the peeling strength of several different copper joints soldered with eutectic SnBi alloy has been measured. This kind of machine is well known by those skilled in the art for measuring the properties of the solder joints.
[0036] The joints were obtained by soldering at 250° C. in an industrial oven with N 2 (O 2 100 ppm) atmosphere; Sn alloy was deposited as paste on rectangular Cu foils 25 mm wide and 50 mm long, thickness >50μ, in contact with Sn coated rectangular Cu foils of 10 mm width. The deposition was carried out on a 20×20 mM 2 .
[0037] The machine parameters during the test run were:
[0038] sampling rate 10 points/sec
[0039] crosshead speed 5 mm/min
[0040] humidity 55%
[0041] temperature 21 C.
[0042] The peeling length was established according to the run, in the range corresponding to a constant peeling load.
[0043] The results obtained are as follows:
Average peeling strength Standard deviation ZAB pretreatment 1.10 N/mm ± 0.09 ETA pretreatment 0.87 N/mm ± 0.66
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A method of pretreating a copper surface for protecting the surface from oxidation, by immersing the surface in a solution containing organic solderabilty preservatives, such as BenzoTriAzole, with the addition of a zinc salt. The method is particularly useful in the manufacturing of electronic Printed Circuit Boards for protecting the copper surfaces during the solder processes when the PCB undergoes high temperature. The addition of the zinc salts also gives the additional advantage of increasing the solderabilty properties of the copper surface (i.e. wettability and adhesion).
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to the field of drilling Earth formations below the bottom of a body of water. More specifically, the invention relates to remotely operated drilling devices that are positioned on the sea floor.
2. Background Art
Drilling through Earth formations located below the bottom of a body of water generally require the use of drilling equipment deployed from a barge or ship, and in the case of deep water sites, from a drillship or semisubmersible floating drilling platform. Such drilling is a complicated and expensive operation, particularly in deep water where a drilling riser must be extended from the floating drilling structure to the sea floor to provide a return conduit for drilling fluid from the well as it is drilled. In addition to cost, drilling using such riser is not well suited to drilling tasks requiring precise control of bit weight, stability (motion compensation) of the drill string and exact positioning of tools within the borehole. Positioning of the surface vessel over the borehole on the seabed is of critical importance when a drilling riser is used. Multiple anchors or dynamic positioning are required to maintained the required degree of positional stability of the floating drilling platform. The in-water weight of the riser limits the water depth in which risers can be deployed. Floating drilling platforms capable of handling long risers for deep water are by necessity very large vessels.
In an attempt to minimize the above noted aspects of drilling in deep water, several seafloor based drilling systems have been developed and are in current operation. “BMS #1” and “BMS #2” are owned by JOGMEC (Japan), “PROD” is owned by Benthic Geotech Pty. Ltd. (Australia), “MeBo” is owned by the University of Bremen (Germany) and “RD2” is owned by the British Geologic Survey. The forgoing remotely operated systems have proven effective in drilling into the seabed, particularly in deep water. Because they all use a flexible umbilical rather than a drilling riser, the in-water weight of such systems is typically less than 20 tons and as a result drilling operations can be conducted from vessels as small as 50 m in length. Station keeping (positional stability) requirements for the vessel are much less stringent than for floating drilling platforms using riser, and an operational watch circle of about 20% of the water depth is adequate in most cases. Because the drilling systems are disposed on the water bottom while drilling and are necessarily heavy enough to provide sufficient reactive mass to advance the drill string, the stability of tools disposed within the borehole is excellent. Complete decoupling of drill string motion from ship motion is accomplished.
When used to drill core samples of the subsurface below the bottom of a body of water, all of such remotely operated water bottom drilling systems depend upon rod coring methodology. A core barrel is disposed at the bottom of a drill string. The core barrel is typically about the same length as one segment of drill pipe or string. As the borehole is extended by drilling, the core barrel is filled and then must be retrieved from the borehole to extract the core therein. Such methodology requires the retrieval of the entire drill string each time a core barrel is recovered. While the foregoing method operated from a water bottom disposed drilling unit eliminates the drill pipe riser extending from the floating drilling platform to the water bottom, the extensive tool handling required by such coring techniques results in a significant operational time to complete boreholes deeper than about 30 meters. A single 100 meter deep borehole using rod coring with standard 3 meter core barrels and drill rods requires more than two thousand tool handling operations and over one hundred hours complete. The extensive time on station and the large number of tool manipulations make rod core drilling impractical for all but shallow holes in deep water.
There exists a need for a water bottom based drilling unit that can obtain core samples with reduced tool handling an operating time.
SUMMARY OF THE INVENTION
A water bottom drilling system according to one aspect of the invention includes a frame configured to rest on the bottom of a body of water. A support structure is movably coupled to the frame. The support structure is configured to enable at least vertical movement of a drill head mounted on the support structure. A winch is movably coupled to the support structure and configured to enable lateral movement of the winch mounted on the support structure. The winch includes a cable thereon. An end of the cable includes a latching device thereon configured to latch onto an upper end of a core barrel disposed in the lower end of a drill string. A storage area is associated with the frame for drill rods and for core barrels. The core barrels each include a latch configured to releasably engage with a lowermost drill rod on a drill string. Each core barrel includes a latch configured to engage the latching device at the end of the cable. At least one clamp is associated with the frame and is arranged to fix a vertical position of a drill string over a drill hole.
A method for drilling formations below the bottom of a body of water includes disposing a drilling system on the bottom of the body of water. The formations are drilled by rotating a first drill rod having a first core barrel latched therein and advancing the drill rod longitudinally. At a selected longitudinal position, an upper end of the first drill rod is opened and a cable having a latching device at an end thereof is lowered into the first drill rod. The winch is retracted to retrieve the first core barrel. The first core barrel is laterally displaced from the first drill rod. A second core barrel is inserted into the first drill rod and latched therein. A second drill rod is affixed to the upper end of the first drill rod. Drilling the formation is then resumed by longitudinally advancing and rotating the first and second drill rods. The above procedure may be repeated by opening the upper end of the uppermost drill rod, retrieving the core barrel using the winch, displacing the retrieved core barrel, inserting a new core barrel in the drill string until it latches in the first drill rod, affixing a new drill rod to the upper end of the drill string, and resuming drilling.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a ship deploying a drilling system on the bottom of a body of water.
FIG. 2 shows a plan view of an example drilling system according to the invention.
FIG. 3 shows a side view of the drilling system shown in FIG. 2 .
FIG. 4 shows an end view of the drilling system shown in FIG. 2 .
FIGS. 5A through 5H show one example of a drilling method according to the invention.
FIG. 6 shows a cut away view of a core barrel latched inside a drill rod.
DETAILED DESCRIPTION
FIG. 1 shows a ship or vessel 2 having a winch 3 or similar spooling device thereon on the surface of a body of water 4 such as the ocean. The winch 3 can spool and unspool a deployment cable 6 and an umbilical cable 34 used to deploy a drilling system 10 on the bottom 11 of the body of water. The deployment cable 6 may nor may not be part of the same physical cable as the umbilical cable 34 . A water bottom based drilling system 10 is deployed using the cable 6 and is caused to rest on the bottom 11 of the body of water. After drilling operations are completed, the system 10 may be retrieved and returned to the vessel 2 .
A plan view of an example drilling system is shown in FIG. 2 . The system 10 is mounted on a frame 12 that provides support for the various components of the system 10 . The frame 12 may have support legs 14 disposed on two corners to maintain the frame 12 in suitable orientation when the system 10 is disposed on the bottom of a body of water. An adjustable height leveling leg 16 may be disposed on the opposite side of the frame. Alternatively, all the legs 14 , 16 may be adjustable height. An electrical and hydraulic power unit 30 may accept electrical and/or hydraulic power through the umbilical cable ( 34 in FIG. 1 ) that extends from the system 10 to the vessel ( 2 in FIG. 1 ) on the water surface. The frame 12 may include one or more features used to lower the system 10 through the water using the winch ( 3 in FIG. 1 ) or similar device deployed on the vessel ( 2 in FIG. 1 ). Deployment of the system can be similar to that using water bottom deployed drilling systems known in the art, and the manner of deployment of the system 10 is not intended to limit the scope of the invention. Electrical and/or hydraulic power supplied by and through the power unit 30 may operate the various devices disposed on the frame 12 as will be further explained below. The power unit 30 may include a fluid pump (not shown separately) to circulate flushing fluid for drilling operations.
The frame 12 may include a drill head support structure 18 . Such structure may include devices for vertically raising and lowering a drill head ( 32 in FIG. 3 ) and for moving the drill head laterally along the frame 12 so that the drill head may be coupled to a drill string, and may be moved out of the way of the drill string so that certain operations described below may be performed on and within the drill string.
The frame 12 also supports a wireline winch 20 . The winch may include a selected length of armored cable 22 thereon (see also 22 A in FIG. 5D ). The cable may or may not have one or more insulated electrical conductors therein. The cable 22 may also be slickline, wire rope or synthetic fiber line. The purpose for the winch 20 and cable 22 will be further explained below with reference to FIGS. 5A through 5H . The winch 20 may be mounted on a support structure 23 that enables the winch 20 to be moved laterally along the frame. Either or both support structures 18 , 23 may include devices such as hydraulic rams (not shown) to enable lateral movement of the drilling head and the winch, respectively. Other examples of devices to provide lateral movement capability may include a toothed rack and motor driven spur gear. The particular implementation used to laterally move either support structure 18 , 23 is not intended to limit the scope of the invention.
The frame 12 may also include storage area for drill rods 24 and for core barrels 26 , respectively. A tool handling gantry 28 may be coupled to the frame 12 and arranged to remove drill rods (see 60 in FIG. 5A ) from the storage area 24 or to replace drill rods in the storage area 24 . The tool handling gantry 28 may also be arranged to move core barrels (see 62 in FIG. 5A ) to and from the storage area. Typically the tool handing gantry 28 will move the drill rods or core barrels so that they can be retained by jaws or grippers on a tool handling arm ( 44 in FIG. 3 ) that grabs the respective core barrel or drill rod from its outer surface so that the interior of the respective core barrel or drill rod is accessible.
A side view of the system 10 is shown in FIG. 3 . A drill head 32 is shown in its rest position to enable operations within the interior of the drill string. The lower portion of the frame 12 supports an alignment clamp 48 , upper foot clamp 50 , lower foot clamp 52 and casing clamp 54 . The various clamps are used to lock in place elements of the drill string as additional drill rods are added thereto or removed therefrom. The tool handing gantry ( 28 in FIG. 1 ) may also include a grabber 42 for oversized drilling tools. The tool handing gantry 28 may also include a handling arm and jaw 44 as explained above. Drilling tools may be stored in a respective tool magazine 46 .
An end view of the system is shown in FIG. 4 .
Having explained the principal components of a water bottom disposed drilling system, a method of operating such system will now be explained with reference to FIGS. 5A through 5H . First referring to FIG. 5A , at the start of drilling operations, an assembly of a drill rod 60 and core barrel 62 latched inside the drill rod 60 is coupled to the drill head 32 and is suspended above the water bottom 11 . In some implementations the drill head 32 may include an hydraulically operated motor or electric motor (neither shown separately) to cause rotation of the drill rod 60 . The drill head 32 may also include an hydraulic swivel (not shown) to enable pumping of flush fluid through the interior of the drill rod 60 during drilling operations and in particular while the drill rod 60 is being rotated. Other implementations may include a means for rotating the drill rod 60 coupled to the frame proximate one or more of the clamps (see FIG. 3 ). The manner of rotating the drill rod 60 is left to the discretion of the system designer and is not intended to limit the scope of the invention. An annular opening core bit 63 may be disposed at the bottom of the drill rod 60 to drill the subsurface formations while enabling a substantially cylindrical core of such formations to be moved into the interior of the core barrel 62 as the drill string advances downwardly below the water bottom 11 . The beginning of such drilling a borehole 13 using the first assembly of drill rod 60 and core barrel is shown in FIG. 5B .
In FIG. 5C , the borehole 13 is drilled such that the first drill rod is moved to the lowermost possible position within the drilling system, and to continue extending the borehole 13 would require lengthening the drill string by coupling to an upper end thereof an additional drill rod 60 . In FIG. 5C , the drill string is raised so that the drill rod 60 may be securely locked in the foot clamp 50 . The drill head 32 may then be removed from the upper end of the drill rod 60 . Such removal may be performed by rotationally locking the drill rod and counter rotating the drill head 32 , or by rotationally locking the drill head 32 and rotating the drill rod 60 using a breakout device (not shown) in the foot clamp 50 . Alternatively, the drill head 32 may include a top drive having an hydraulic chuck. The manner of making and breaking connections between the drill head 32 and the drill rods 60 and between adjacent interconnected drill rods 60 is not intended to limit the scope of the invention. After the drill head 32 is uncoupled from the drill rod 60 , the drill head 32 may be laterally repositioned using, for example, the device shown at 18 in FIG. 1 . Laterally repositioning the drill head 32 enables moving devices inside the drill rod 60 and/or coupling additional drill rods to the drill rod 60 partially disposed in the borehole 13 . When one or more additional drill rods are coupled to the drill rod 60 disposed in the borehole 13 , the assembly is referred to as a “drill string.” As an alternative to lateral repositioning, the drill head 32 may be moved longitudinally to a height above the upper end of the drill rod 60 sufficient to enable moving the winch over the drill rod to provide access by cable 20 to the interior of the drill rod 60 .
In FIG. 5D , the winch 22 is laterally repositioned such that an end of the cable 22 A is disposed directly above the drill rod 60 locked in the foot clamp 50 . The winch 22 is then operated such that an overshot 56 of any type known in the art is lowered into the interior of the drill rod 60 and is then latched to a mating feature ( FIG. 6 ) in the upper end of the core barrel 62 . The core barrel 62 may then be removed from the interior of the drill rod 60 by unlatching by the action of the overshot 56 . The winch 22 may then be laterally repositioned such that the core barrel 62 previously retrieved from the inside of the drill rod 60 may be grabbed by the tool arm ( 44 in FIG. 3 ) and moved to be stored in the storage area ( 26 in FIG. 1 ).
In FIG. 5E , another core barrel 62 may be retrieved from the storage area ( 26 in FIG. 2 ) and coupled to the drill head 32 . Such coupling may be performed by using the tool handling device ( 28 in FIG. 2 ) to hold the core barrel in a lateral position above the drill rod 60 still in the borehole 13 and latching the drill head 32 to the upper end thereof. The drill head 32 may then be lowered such that the new core barrel 62 is inside the drill rod 60 . The new core barrel 62 may then be pumped to the bottom of the drill rod 60 and latched into position in the drill rod 60 .
In FIG. 5F , an additional drill rod 60 may be coupled to the drill head 32 , and the drill head 32 lowered so that the additional drill rod 60 is affixed to the drill rod 60 still locked in the foot clamp 50 . The foot clamp 50 may then be released, and as shown in FIG. 5G , drilling may resume by rotating and longitudinally advancing the drill string. Drilling continues typically until the uppermost drill rod reaches the lowest possible position in the system, as shown in FIG. 5H . At such time, the procedure explained with reference to FIGS. 5C through 5F can be repeated, and drilling may continue for each successive additional drill rod coupled to the drill string until the borehole 13 is extended to the intended depth.
By retrieving core barrels 62 from the lowermost drill rod 60 using the wireline overshot 56 as explained above, successive core samples may be withdrawn from the borehole 13 without the need to retrieve the entire drill string each time a core barrel is retrieved. Such capability substantially reduces the number of tool operations and amount of time needed to drill a borehole below the bottom of a body of water.
A cut away view of a drill rod 60 having a core barrel 62 therein is shown in FIG. 6 . The core barrel 62 may include a fishing neck 64 configured to engage the overshot ( 56 in FIG. 2 ). The core barrel 62 may include a latch 68 that can be released by the upward force exerted by the cable ( 22 in FIG. 1 ) when the core barrel 62 is to be retrieved from the drill rod 60 . A shoulder 66 inside the drill rod 60 may provide a seat to retain the core barrel 62 when it is pumped into the drill rod 60 .
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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A method for drilling formations below the bottom of a body of water includes disposing a drilling system on the bottom of the body of water. The formations are drilled by rotating a first drill rod having a first core barrel latched therein and advancing the drill rod longitudinally. At a selected longitudinal position, an upper end of the first drill rod is opened and a cable having a latching device at an end thereof is lowered into the first drill rod. The winch is retracted to retrieve the first core barrel. The first core barrel is laterally displaced from the first drill rod. A second core barrel is inserted into the first drill rod and latched therein. A second drill rod is affixed to the upper end of the first drill rod. Drilling the formation is then resumed by longitudinally advancing and rotating the first and second drill rods.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not Applicable
REFERENCE TO A MICROFICHE APPENDIX
[0005] Not Applicable
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Invention
[0007] The present invention relates to modified hydrophilic polymers such as hyaluronic acid, also known as hyaluronan and mixtures thereof, containing hydrophobic silicone groups prepared by reaction of the hydrophilic polymer with epoxy-functional-silicones, their preparation and compositions containing them.
[0008] 2. Description of Related Art
[0009] Relevant prior art includes the following references: U.S. Pat. No. 7,521,434 discloses cross-linked gels of hyaluronic acid with hydrophobic polymers and processes; Mensitieri et al. Journal of Material Science; Materials in Medicine (1994) pages 743-747; The rheological behavior of animal vitreus and its comparison with vitreal substitutes; and Schwarz, K. Proc Nat Acad Sci (1973) Vol 70 pp 1608-1612; A Bound form of Silicon in Glycosaminoglycans and Polyuronides.
[0010] Hyaluronic acid (HA) and its derivatives are important materials used in the medical and cosmetic industry. Their unique viscoelastic properties combined with their high water binding properties and exceptional biocompatibility have led to a wide variety of products in the ophthalmic, arthritis, wound healing, anti-adhesion, drug delivery, soft tissue augmentation, and burn management fields, as well as use in topical cosmetic moisturization. It is an excellent biomaterial for a variety of combined uses the medical field due to its viscoelastic and biocompatibility properties. The water binding and hydration properties of hyaluronic acid provide water to the skin. This moisturizing effect is widely used in the cosmetic industry.
[0011] Hyaluronic acid is a naturally occurring polysaccharide that consists of alternating N-acetyl-D-glucosamine and D-glucuronic acid monosaccharide units linked with alternating [beta] 1-3 glucoronidic and [beta] 1-4 glucosaminidic bonds. The molecular weight of hyaluronic acid is generally within the range of 50,000 up to more than 8,000,000
[0012] Hyaluronic acid is found in all vertebrates—in the skin, vitreous humor, the synovium, the cartilage, and the umbilical cord. It is not species specific and therefore highly biocompatible. It is known for its efficiency of hydration, it has a binding capacity of up to 20 times its weight in water and it is the natural moisturizer in the cell matrix of the skin. It typically exists at concentrations of 200 micrograms per gram of dermal tissue. Cross-linking of HA has been used to improve the physical properties of the molecule and to enhance its properties for various uses, or to immobilize the HA to various supports for medical purposes including the diagnosis of male infertility. Formulations of hyaluronic acid have been used by the cosmetic industry as skin moisturizers. One important use of hyaluronic acid and its derivatives is founded in its properties as a drug delivery vehicle. Various drug and other biological actives have been loaded into hydrogels of HA and its derivatives; however there are some limitations on the types of substances capable of being loaded based on their chemical nature. Hydrogels composed largely of water have difficulty accepting substances of hydrophobic nature. Some organic solvents used to solubilize a hydrophobic substance will dehydrate the hydrogel or precipitate the HA. Some methods have been developed to overcome this problem although there is still difficulty with some substances. Hyaluronic acid has been used for delivery of drugs such as diclofenac.
[0013] Silicones are also a very versatile class of compounds used for many applications in the medical field and cosmetic industry. Topical application of silicones have been used for wound healing, drug delivery and burn treatment and are also topically used in cosmetic formulations. Silicones are in general, hydrophobic and their moisturizing properties are due to their ability to provide a vapor barrier to the skin.
[0014] Silicone Gels are also used for delivery purposes in the medical field and the cosmetic industry. Their hydrophobic nature makes them excellent vehicles for incorporating hydrophobic substances. Silicone implants are used to deliver contraceptives and other hydrophobic drugs.
BRIEF SUMMARY OF THE INVENTION
[0015] The invention provides, in one aspect thereof, chemically modified products of hydrophilic polymers and one or more silicone containing compounds. The hydrophilic polymer may be a natural or synthetic polysaccharide, including heparin, heparin sulfate, chondroitin, chondroitin sulfate, hyaluronic acid, hydroxyethyl cellulose, carboxymethyl cellulose and an alginates. The compositions of the invention may also contain one or more hydrophobic substances, including oils, silicones, sun screens, antibiotics and steroids.
[0016] In another aspect, the invention provides methods for making the modified products by subjecting them to reaction with an epoxy functionalized silicone compound in an aqueous alkaline solution at a temperature of about 20° C. The HA concentration before reaction with the epoxy compound may range from 20% to 0.01%, preferably about 3%. The molar ratio of the epoxy silicone compound to HA may range from 1:20 to 4:1, and preferably about 2:1. It should be noted that excess epoxy silicone can be used to drive the reaction forward. By this is meant that even though at a given range of a 4:1, the molar ratio is actually in excess of the needs at reactive sites, one can continue to add more reactive epoxy which will affect of kinetics, i.e., driving the reaction forward, even though the amount of reactant that will react is limited.
[0017] The compositions of the present invention combine the advantages of both hyaluronic acid and silicone gels in that they contain both hydrophobic and hydrophilic moieties. The modified hyaluronic acid has the ability to incorporate both large volumes of water and hydrophilic substances as well as hydrophobic substances such as oils, sun screens, vitamins, antibiotics, steroids and other drugs. Thus, there is provided an improved drug delivery vehicle. The nature of the material also provides a composition which is hydrophobic in nature and is thus easier to formulate in a cosmetic composition.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention provides for the preparation of compositions of chemically modified polysaccharides prepared in the presence of an epoxy functionalized silicone compound, wherein the ratio of the silicone compound to the polysaccharide is 1:20 to 4:1, and the concentration of the polysaccharide in the aqueous solution is from 0.05 to 100 mg/ml.
[0019] The present invention relates to compositions prepared by the process of incorporating the silicone compound through an epoxy functionalized silicone compound and conducting a chemical reaction in the presence of the polysaccharide such as hyaluronan (HA).
[0020] The present invention provides compositions of polysaccharide products prepared with an epoxy functionalized silicone compound in the family of epoxy functionalized silicones such as 2 (3,4 epoxycyclohexyl)ethyltrimethoxysilane, epoxypropoxypropyl terminated polydimethylsiloxane, tris (glycidoxypropyldimethylsiloxy) phenylsilane, mono-(2,3-epoxy) propylether terminated polydimethylsiloxane-120 cSt, epoxycyclohexylethyl terminated polydimethylsiloxane, 25-35 cSt and glycidoxypropyltrimethoxysilane.
[0021] The products of the invention are prepared by reacting the epoxy silicone compound or compounds in the presence of the polysaccharide such as hyaluronan (HA) to obtain a modified polysaccharide. More than one epoxy functionalized silicone can be used, each having a variety of properties that contribute to the final product; for example by changing the hydrophobic-hydrophilic nature, contributing to the charge of the molecule, or the final viscosity of the product.
[0022] The silicon compound incorporated may also be a group capable of undergoing further polymerization or reactions with new functional groups such as trialkoxysilanes, dialkoxysilanes, monoalkoxysilanes, and vinyl groups, added, allowing further modification of the product.
[0023] The present invention provides for a material that can be used alone or with other substances which may be added to enhance the properties for a particular purpose. These products may be added or covalently bound substances that can be applied for numerous applications including, for the use in cosmetic, medical, and drug delivery fields.
[0024] The present invention provides for a biocompatible material, such materials which may be useful as a stable form of implants. HA implants have limited duration since natural mechanisms for the clearance from the body; a more resistant implant can improve the efficacy and durability of devices used for soft tissue augmentation, drug delivery, anti-adhesion, ophthalmic, and anti-arthritis.
[0025] The present invention provides for a topical composition with a hydrating effect on the skin. Hyaluronic acid provides a high water binding capacity, typically 20 grams of water per gram of hyaluronic acid, such a composition will provide a high degree of moisturization to the skin. Compositions of hyaluronic acid have been used to promote wound healing and reduce scaring. Silicone gels and semi-occlusive membranes are commercially available, e.g., Cica Care Silicone Gel Dressing Sheeting—by Cica Care, ScarAway Professional Grade Silicone Scar Treatment Sheets by Mitchell-Vance Laboratories and ScarErase by ScarErase. Inc. for the treatment of chalets and hypertrophic scars. It is believed that silicon membranes create a barrier impermeable to water thereby creating a moisturization effect reducing scarring.
[0026] The present invention is based on hyaluronic acid, a naturally occurring polysaccharide in the human body. It is a common constituent in the tissues and is highly biocompatible. Since the molecule is not species specific it is not antigenic and therefore non-immunogenic. The normal content of hyaluronic acid in the skin is 0.2 mg/gram of tissue, although since it is limited to the extracellular space the concentration of HA in the fluid of the extracellular space is actually about 2.5 mg/ml in concentration. It can therefore be appreciated that the present invention will be a non-inflammatory non-irritating biologically acceptable treatment.
[0027] The following examples will further illustrate the invention in more detail.
EXAMPLES
Example 1
[0028] 4.00 gms of sodium hyaluronate (HA from viable hemolytical streptococci, Molecular Weight 1.93 million.) were mixed for one day with 96 gms of deionized water to give a 4.0% solution of HA. 7.5 ml of 2.0 M NaOH were then added to the mixture and stirred on a Silverson High Shear Mixer, for 1 minute using a low-shear-head at 400 rpm. Then, 2.5 gms of 2(3,4 epoxycyclohexyl)ethyltrimethoxysilane were added. The sample was mixed for 1 minute using a low-shear-head at 400 rpm on a Silverson High Shear Mixer. The pH was adjusted to 12 by the addition of 2.0% HCl while mixing. The reaction was allowed to continue for four hours before neutralizing the reaction mixture by the addition of 70 ml 2.0% HCl. The final volume was 182.00 gms. The product was washed in dialysis tubing against 2 kg of distilled water, and the water was exchanged 5 times. 182.00 gms of a creamy white product were formed.
Example 2
[0029] 15 gms of sodium hyaluronate (HA from viable hemolytical streptococci, Molecular Weight 1.93 million.) were suspended in 150 ml of methanol. 225 ml of distilled water and 30 ml of 0.2 M NaOH were added to hydrate the HA. Then, 7.5 gms of 2(3,4 epoxycyclohexyl)ethyltrimethoxysilane were added and stirred for 15 minutes. 150 ml of 50% methanol in water were added and stirring continued. After 30 min the pH was reduced to 9 by the addition of 14 ml of 2% HCL. The reaction was continued for 2 hours. The reaction product was neutralized to pH 7 with 2% HCL, and the volume adjusted to 1500 ml by the addition of distilled water. The product was placed into dialysis vs 20 kg of distilled water. The wash water was exchanged 3 times over 2 days. 1626 gms of a creamy white product were formed.
Example 3
[0030] This example illustrates the preparation of a modified HA/silicone product prepared under aqueous conditions. 15.00 gms of sodium hyaluronate (Microbial Fermented HA, Molecular Weight 2.07 million.) were mixed for one day with 485 gms of deionized water and the HA was allowed to hydrate overnight to give a 3.0% solution of HA. 42.5 ml of 2.0 M NaOH were then added to the mixture and stirred with a kitchen aid mixer, for 10 minutes stirred at low speed until a smooth consistency was obtained. Then, 12.5 gms of mono-(2,3-epoxy) propylether terminated polydimethylsiloxane-120 cSt were added. The sample was mixed for 45 minutes using a kitchen aid mixer at low speed. The pH was adjusted to 12 by the addition of 2.0% HCl while mixing. The reaction was allowed to continue for two hours before neutralizing by the addition of 355 ml 2.0% HCl. The mixture was brought up to 1 kg with water and was washed in dialysis tubing against 20 L of distilled water. The wash water was exchanged 5 times over 2 days. 1565 gms of a creamy white product having a smooth and silky feel were formed.
Example 4
[0031] This example illustrates the preparation of a modified HA/silicone product prepared under aqueous conditions. 15.00 gms of sodium hyaluronate (Microbial Fermented HA, Molecular Weight 2.07 million.) were mixed for one day with 485 gm of deionized waters and allowed the HA to hydrate overnight to give a 3.0% solution of HA. 42.5 ml of 2.0 M NaOH were then added to the mixture and stirred with a kitchen aid mixer for 10 minutes stirred at low speed until a smooth consistency was obtained. Then, 12.5 gms of epoxycyclohexylethyl terminated polydimethylsiloxane, 25-35 cSt were added. The sample was mixed for 45 minute using a kitchen aid mixer at low speed. The pH was adjusted to 12 by the addition of 2.0% HCl while mixing. The reaction was allowed to continue for two hours before neutralizing by the addition of 355 ml 2.0% HCl. The mixture was brought up to 1 kg with water and was washed in dialysis tubing against 20 L of distilled water. The wash water was exchanged 5 times over 2 days. 1187 gms of a creamy white product having a smooth and silky feel was formed.
Example 5
[0032] This example illustrates the preparation of a modified HA/silicone product prepared under aqueous conditions. 3.00 gms of sodium hyaluronate (Microbial Fermented HA, Molecular Weight 2.07 million.) were mixed for one day with 97 gms of deionized water and the HA was allowed to hydrate overnight to give a 3.0% solution of HA. 14.5 ml of 0.2 M NaOH were then added to the mixture and stirred at 800 rpm with a Lightnin brand overhead mixer for 10 minutes, stirred at low speed until a smooth consistency was obtained. Then, 0.2 gram of glycidoxypropyltrimethoxysilane (Dow Corning Z-6040) was added. The sample was mixed for 45 minute at 800 rpm with a Lightnin overhead mixer. The pH was adjusted to 12 by the addition of 2.0% HCl while mixing. The reaction was allowed to continue for two hours before being neutralized by the addition of 8 ml 2.0% HCl. The mixture was brought up to 200 ml with water and 150 ml were washed in dialysis tubing against 10 L of distilled water. The wash water was exchanged 5 times over 2 days. 247 gms of a clear transparent product were formed.
Example 6
[0033] This example illustrates the preparation of a modified HA/silicone product prepared under aqueous conditions. 15.00 gms of sodium hyaluronate (Microbial Fermented HA, Molecular Weight 2.07 million.) were mixed for one day with 485 gms of deionized water and the HA was allowed to hydrate overnight to give a 3.0% solution of HA. 42.5 ml of 2.0 M NaOH were then added to the mixture and stirred with a kitchen aid mixer, for 10 minute stirred at low speed until a smooth consistency was obtained. Then, 12.5 gms of 2(3,4 epoxycyclohexyl)ethyltrimethoxysilane were added. The sample was mixed for 45 minute with a kitchen aid mixer at low speed. The pH was adjusted to 12 by the addition of 2.0% HCl while mixing. The reaction was allowed to continue for two hours before being neutralized by the addition of 355 ml 2.0% HCl. The mixture was brought up to 1 kg with water and was washed in dialysis tubing against 20 L of distilled water. The wash water was exchanged 5 times over 2 days. 1248 gms of a creamy white product having a smooth and silky feel were formed. The product was preserved with 6.25 gram of phenonip.
Example 7
[0034] Five glass vials filled with 20 ml of the sample prepared in Example 2, and placed in an incubator at 37° C. or stored in the dark at room temperature (22° C.). A vial was removed at each of 1, 5, 8, and 12 month time points to monitor changes in appearance, consistency, pH, and viscosity of the product. The viscosity was measured on a Brookfield DV II+ Pro viscometer, Spindle #25 with a small cup adapter and a shear rate of 13.2 sec-1, at 25° C.
[0035] No significant changes in the sample were noted over one year. Only a small decrease was noted in the viscosity, indicating that the product was stable.
[0000]
37° C. Stability Study
Time point
(months)
Appearance
Consistency
pH
Viscosity
% change
0
No change
No change
7.5
2362
0
1
No change
No change
7.5
2404
+1.8
5
No change
No change
7.5
2475
+4.8
8
No change
No change
7.5
2302
−2.5
12
No change
No change
7.5
2194
−7.1
[0000]
22° C. Stability Study
Time point
(months)
Appearance
Consistency
pH
Viscosity
% change
0
No change
No change
7.5
2362
0
1
No change
No change
7.5
2491
+5.5
5
No change
No change
7.5
2487
+5.3
8
No change
No change
7.5
2364
−0.2
12
No change
No change
7.5
2358
−7.1
Example 8
[0036] The product Example 6 was sent for a Human Repeat Insult Patch Test to an independent lab in order to determine if the material causes any irritation or allergic reaction. The skin of 50 subjects were tested, 24 hour exposures to the product made in Example 6 three times a week for three consecutive weeks. The skin was evaluated after each application. Following a 10-14 day rest, a retest/challenge dose was applied an evaluated after 48 and 96 hours. The test sites were scored according to standards set by The International Contact Dermatitis Research Group (ICDRG). No adverse reactions of any kind were reported. There were no signs or symptoms of sensitization (contact dermatitis).
Example 9
[0037] This example illustrates the preparation of a formulation with a product prepared in Example 2 plus hydrophobic compounds and 49.5% water.
[0000]
Percent
Grams
Part
Ingredient
by Weight
required
A
product in Example 2
44.0
44.0
Parsol MCX
2.5
2.5
Silicone Fluid 200
2.5
2.5
phenonip
0.5
0.5
water
49.5
49.5
B
Carbopol 934
0.5
0.5
C
Triethanolamine
0.5
0.5
[0038] 44 gms of the product prepared in example 2 were added to the remaining ingredients in part A. The mixture was stirred until completely mixed. Part A and Part B were mixed and placed on a shaker overnight. Triethanolamine was then added to create a thick cosmetic cream.
Example 10
[0039] This example illustrates the preparation of a formulation with a product prepared in Example 3 plus hydrophobic compounds and 49.5% water.
[0000]
Percent
Grams
Part
Ingredient
by Weight
required
A
product in Example 3
44.0
44.0
Parsol MCX
2.5
2.5
Silicone Fluid 200
2.5
2.5
phenonip
0.5
0.5
water
49.5
49.5
B
Carbopol 934
0.5
0.5
C
Triethanolamine
0.5
0.5
[0040] 44 gms of the product prepared in example 3 were added to the remaining ingredients in part A. The mixture was stirred until completely mixed. Part A and Part B were mixed and placed on a shaker overnight. Triethanolamine was then added to create a thick cosmetic cream.
Example 11
[0041] This example illustrates the preparation of a formulation with a product prepared in Example 2.
[0000]
Percent by
Grams
Part
Ingredient
Weight
required
A
product in
79.2
79.2
Example 2
Carbopol 934
0.5
0.5
B
Vitamin E
3.96
3.96
Parsol MCX
3.96
3.96
Silicon Quat
11.08
11.08
Microemultion
C
Triethanolamine
0.5
0.5
D
Roseoil W/S
0.3
0.3
Phenonip
0.5
0.5
[0042] 79.2 gms of the product prepared in example 2 were mixed with Carbopol 934 in part A The mixture was stirred until completely mixed. Part B was prepared by mixing the ingredients in Part B using a lab mixer. Part A and Part B were combined and mixed until uniform. Triethanolamine in Part C was then added to create a thick cosmetic cream. Roseoil W/S and Phenonip in Part D were added.
Example 12
[0043] This example illustrates the preparation of a formulation with a product prepared in Example 2 and 44.5% Petrolatum.
[0000]
Percent by
Grams
Part
Ingredient
Weight
required
1
product in
20
20
Example 2
water
20
20
2
Carbopol 934
0.3
0.3
3
Petrolatum
44.5
44.5
Vitamin E acetate
5.0
5.0
Parsol MCX
7.4
7.4
4
Triethanolamine
0.3
0.3
1% Sodium
2
2
Hyaluronate in
Water
5
phenonip
0.5
0.5
[0044] In part 1, 20 gms of the product prepared in example 2 were added to 20 gms of water and mixed until a uniform viscous solution formed. 0.3 gm of Carbopol 934 was added to the mixture in part 1 and mixed using a lab stirrer for 20 minutes until a uniform dispersion formed. 45 gms of petrolatum were mixed with 5 gms of Vitamin E acetate and 7.4 gms of Parsol MCX in part 3 and heated to 60° C. while mixing and continued until a clear mixture was obtained. The mixture obtained in Part 2 was heated to 60° C. The mixtures obtained in Part 2 and Part 3 were combined and cooled to 30° C. 1% Sodium Hyaluronate in water and triethanolamine in part 4 were mixed with the 30° C. mixture and stirred until thickened. Phenonip (0.5 gram) was added as a preservative.
Example 13
[0045] This example illustrates the preparation of a formulation with a product prepared in Example 2.
[0000]
Percent by
Grams
Part
Ingredient
Weight
required
A
Vitamin E
5.0
5.0
Robane
4.0
4.0
Silicon Quat
8.0
8.0
Microemultion
Parsol MCX
5.0
5.0
Triethanolamine
0.4
0.4
B
product in
64.4
64.4
Example 2
Carbopol 934
0.4
0.4
C
Water
10.0
10.0
Glycerol
2.0
2.0
D
phenonip
0.5
0.5
Rose Natural
0.3
0.3
water soluble
[0046] In part A 5 gms of Vitamin E, 4 gms of Robane, 8 gms of Quat silicone microemulsion, and 5 gms of Parsol MCX were combined and mixed until a uniform mixture was obtained. 0.4 gm of Triethanolamine was added and mixed thoroughly. The ingredients in Part B were mixed in a separate container, 0.4 gm of Carbopol 934 was dispersed into 64.4 gram of the product obtained in Example 2 and stirred until completely mixed. Water and Glycerol in Part C were mixed together then combined with Part B and thoroughly mixed. The mixture comprising Part B and Part C was Mixed with Part A and stirred until a thick uniform mixture was obtained. Phenonip (0.5 gram) was added as a preservative. Rose natural water soluble was added at the end.
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Disclosed are hydrophilic polymers such as polysaccharides, including hyaluronic acid of any origin, modified by reaction with epoxy-functional-silicones. Hydrophobic silicon, which contains chemically active groups covalently attach to the backbone of the hydrophilic polymer and gives these new, modified polymers the ability to dissolve hydrophobic compounds including oils, drugs, and vitamins, while maintaining the hydrophilic properties and benefits of the unmodified polymer. With respect to topical applications these polymers substantially increase the stability of formulations and provide for ease of preparation. The properties and advantages of the original polymer are maintained while other properties are augmented, namely the ability to combine with or dissolve hydrophobic and hydrophilic drugs. The products can be used alone or in combination with other substances for various applications including cosmetic, medical, and drug delivery applications. Also disclosed are methods for preparing them.
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BACKGROUND OF THE INVENTION
This invention relates to the field of hand knitting machines and more particularly to an improved carriage and cam control system for a knitting machine of this character capable of producing both Punch Lace and Fair Isle knitted patterns.
It is conventional to utilize with the needle bed of a hand knitting machine a carriage which mounts a plurality of cams on its underface so that when it is reciprocated along the slide rails of the bed the cam system operates upon the butts of the needles to effectuate the desired knitting pattern. As is well known, the carriage may be manually operable or it may be adapted for reciprocation under the influence of a motor drive.
Carriages presently in use are capable of producing various patterns of knitting. In order to provide such a capability the several cams are adjustable either through direct individual manipulation or indirectly through the actuation of a punch key and connecting lever. In the latter instances the customary construction links individual punch keys and levers with individual cams. Alternately, a selector dial may be rotated to a predetermined position in order to establish a specific cam raceway for production of a particular knitted pattern. Known carriages of this type generally employ escapement cams which are permanently biased and are, therefore, susceptible to spring failure. Also, such carriages are generally heavy and occupy a relatively large area of the needle bed, thereby increasing the possibility of needle jam-up beneath the carriage.
Further, it has been found desirable to provide a carriage with a capability for producing Punch Lace and Fair Isle knitting patterns. The Singer Model 2200 knitting machine permits the production of the latter pattern but does not enable the operator to produce Punch Lace (a simulated lace pattern), wherein a design of a chosen colored yarn is produced by means of knit stitches on needles selected to form the design. A fine yarn or thread is knit on every needle, thus forming a stocking stitch structure. If some (non-selected) needles form knit stitches with both colored yarn and fine thread, and the remainder of the needles form knit stitches using only the fine thread, a fabric is produced where the fine thread is nearly invisible and the design appearance is formed in colored yarn.
SUMMARY OF THE INVENTION
In view of the foregoing it is one object of this invention to provide a carriage for a hand knitting machine having the capability of producing Punch Lace and Fair Isle knitting patterns.
It is another object of this invention to provide a carriage for a hand knitting machine which is lightweight, occupies a relatively small area of the needle bed of the machine, and affords the operator the choice of a multiplicity of patterns through a simple punch key and interconnecting lever system.
Yet another object is the provision of a carriage for a hand knitting machine having a plurality of punch keys, each of such punch keys being operable to actuate at least one cam of the carriage with which such key is directly connected and at least one of such punch keys being operable to actuate additional cams with which such punch keys are indirectly connected.
According to the present invention there is provided in a carriage for a hand knitting machine having a plurality of cams that are sequentially arranged and adjustable between inoperative and operative positions to thereby define at least one raceway for the butts of needles and in which a plurality of said cams are operatively connectable to individually actuable lever means to be shifted between said inoperative and operative positions, the improvement which comprises means for interconnecting at least one of said lever means with at least one other of said lever means whereby actuation of one of said lever means simultaneously actuates at least one other of said lever means to thereby actuate predetermined combinations of said cams.
According to the present invention there is also provided in a carriage for a hand knitting machine having needle selecting, raise and stitch cams arranged sequentially at both ends thereof, at least one set of Jacquard cams positionable to produce patterned knitting, a cam positioning lever associated with each set of said Jacquard cams and a locking plate for locking said lever in predetermined position to thereby maintain the Jacquard cams associated therewith in the selected pattern, the improvement which comprises upper and lower sets of said Jacquard cams, first lever means operably associated with said upper Jacquard cams and actuable to engage said locking plate and effectuate a shifting of said upper Jacquard cams upwardly from a first position into a second operative position such that a first path is established whereby selected needles are directed over a first of said upper Jacquard cams and beneath the other of said upper Jacquard cams to a point along said path where a first yarn can be accepted and thence to the upper portion of one of said stitch cams and downwardly therealong and out of said carriage, said lower Jacquard cams remaining in a first position such that a second path is established whereby non-selected needles are directed across the top of said lower Jacquard cams to a point where said non-selected needles can accept said first yarn and a second yarn before being directed to substantially the same upper portion of said one stitch cam and downwardly thereof along the same path followed by said selected needles, second lever means operably associated with said lower Jacquard cams and actuable to engage said locking plate and effectuate a shifting of said lower Jacquard cams upwardly from said first position into a second operative position such that non-selected needles are directed over a first of said lower Jacquard cams and beneath the other of said lower Jacquard cams to a yarn-accepting level and thence to join selected needles at a lower region of said one stitch cam, engagement of said second lever means with said locking plate effecting, when said first lever means has already been actuated, sequentially an unlocking of said first lever means from said locking plate and then a relocking of said first lever means by said locking plate, whereby actuation of only said first lever means enables the production of Punch Lace and actuation of said second lever means enables the production of Fair Isle knitting.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more fully understood it will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a carriage embodying the invention;
FIG. 2 is a bottom plan view of the carriage of FIG. 1;
FIG. 3 is a perspective view, broken and partly in section, of the lever and locking plate construction of the carriage of FIGS. 1 and 2;
FIGS. 4a, b and c are plan stagewise views of first and second levers and of the locking plate during positioning of the upper Jacquard cams for production of Punch Lace;
FIGS. 5a, b and c are plan views similar to that of FIGS. 4a, b and c showing stagewise lever and cam settings for production of Fair Isle knitting;
FIG. 6 is a schematic layout of a cam raceway which enables the production of Punch Lace;
FIG. 7 is a view similar to that of FIG. 6 illustrating a cam raceway which enables the production of Fair Isle knitting; and
FIG. 8 is a plan view of the first and second levers according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, there is shown a carriage 10 for a hand knitting machine. The upper face 11 of the carriage is provided with a plurality of punch keys 12 which are connected, through a lever arrangement to be hereinafter described, to selected cams located on the underside 13 of the carriage. By manipulation of the keys the cams may be arranged in a predetermined manner so as to present to the knitting needles a raceway through the cam system 14 for the production of the desired pattern. In addition to the punch keys, the upper face of the carriage may be provided with a stitch size dial 15 by which the size of the knitted stitch may be regulated through control of the downward movement of the needles. Three-position needle return buttons 16 and 17 are shown and function in a manner well known to persons having a familiarity with hand knitting machines. A locking plate 18 is mounted on the underside of the carriage and is slidable laterally thereof. This plate 18 is spring biased by compression spring 55, trapped between the locking plate and a pin 56 projecting from the underside 13 of the carriage, so as to urge same towards an extreme lateral position when all of the punch keys are in a nonactuated condition. In such condition the carriage, upon reciprocation, will function in a non-stitching mode. In order to produce patterned knitting it is necessary to depress one or more of the punch keys and to set the three position needle return buttons 16 and 17 to prescribed positions, thereby so positioning the cams as to provide a specific cam raceway for selected and non-selected needles through the cam system.
As can be seen most clearly from FIG. 2, in order to provide the capability for production of Punch Lace and Fair Isle knitting, pairs of upper and lower Jacquard cams 19, 20 resepectively are pivotably mounted on the carriage biased towards their upper operative positions. As will be described hereinafter, with reference to FIGS. 6 and 7 of the drawings, only the upper Jacquard cams need be placed in their upper operative position to produce Punch Lace whereas both upper and lower Jacquard cams must be in their upper operative positions to produce Fair Isle knitting.
As viewed in FIG. 2, upper Jacquard cam control lever 21 is mounted on the underside of the carriage so as to be slidable in a plane below that in which locking plate 18 is adapted to slide and in a direction perpendicular to the direction of movement of the locking plate. Referring to FIG. 8, lever 21 is shown as being formed as a generally elongated member having a main body portion 22 and a shorter offset punch key-receiving shank 23. The main body portion is formed with a pair of longitudinally extending slots 24, 25 dimensioned to accept guide pins or studs 26, 27 which are formed on the carriage and project upwardly therefrom. In this manner the lever is capable of guided movement into engagement with the locking plate to be locked in position when, upon actuation, upper Jacquard cams 19 are moved to their upper operative position. The lever is provided on one side of its body portion, adjacent the end thereof which is remote from the offset shank 23, with a downwardly inclined ramp 28 and with a recess 29. The recess is located closely adjacent the terminus of ramp 28 for a purpose which will be subsequently described. Preferably, a land 30, which may be flat or slightly convex in configuration, connects the end of the ramp and the adjacent side wall of the recess. The free end of body 22 is formed with an upstanding retaining flange 31 which serves to urge upper Jacquard cams 19 into their lower position when the lever 21 is itself in a non-actuated position.
A lower Jacquard cam control lever 32 is mounted on the underside of the carriage and is positioned on studs 26, 27 overlying lever 21. Longitudinally extending slots 33, 34 are provided on the body portion 35 of lever 32, said slots being in longitudinal alignment with the underlying slots of lever 21. As previously described with reference to the upper Jacquard cam control lever 21, lever 32 is formed with a downwardly inclined ramp 36 and with a recess 37 whose adjacent sidewall is spaced from the terminus of ramp 36 by a land 38. This land is preferably given the same configuration as land 30. The body portion of lever 32 is also provided with a pair of wing projections 39, 40 offering lower cam-retaining shoulders 41, 42 by which the lower Jacquard cams may be urged into and maintained in their lower position. As with upper Jacquard cams 19, the lower Jacquard cams 20 are normally biased upwardly towards their upper operative position. The upper surface of the wing projections are desirably tapered to permit movement of the lever without interference with any of the adjacent elements of the carriage or cam-supporting structure. This lever, as with lever 21, is provided with a short offset shank portion 23' for reception of a punch key 12.
As stated previously, locking plate 18 is mounted on the underside of the carriage so as to be slidable laterally thereof. A plurality of ramps 43 are formed thereon at locations where they are respectively engageable by lug means 44 carried by each of the punch key-lever combinations. Thus, depression of any punch key will cause its associated lug to ride along the ramp of the locking plate with which it is engageable to thereby cause the locking plate to slide laterally. A recess 45 is provided on the locking plate at the end of each said ramp and is dimensioned to accept lug 44 of the respective punch key-lever combination. In known manner the punch key-lever is operatively connected with one or more cams such that when the punch key is actuated the cams operatively connected thereto are likewise moved between non-operative and operative positions. Since this aspect of the structure is known, for example from the carriage marketed by The Singer Company as part of their Model 2200 series of hand knitting machines, and is not critical to the present invention this specification will not be encumbered by a description of the details of such structure. Reference is also made to the disclosure of U.S. Pat. Nos. 3,103,110 and 3,120,114 issued Sept. 10, 1963 and Feb. 4, 1964 respectively for further examples of how punch key-lever combinations may be operatively connected to cams of a home knitting machine carriage. Locking plate 18 is also provided with an upstanding lug or ear 46 for disposition in either of recesses 29 or 37 of levers 21 or 32 depending upon which of the punch key-lever combinations is actuated.
Referring now to FIGS. 4 and 5, the operation of cam control levers 21 and 32 will be described. When the operator desires to produce Punch Lace, upper Jacquard cam control lever 21 is depressed. In their initial non-actuated positions levers 21 and 32 are under the influence of spring 50 which acts upon turned up ears 51 and 51' on the respective levers. The lever begins to move upwardly as depicted in FIG. 4a, ramp 28 engaging with lug 46 to urge locking plate 18 to the right against the force of its biasing spring 55. The lever 21 continues upwards until lug 46 reaches the lower terminus of ramp 28. This lug then rides downwardly along land 30 as shown in FIG. 4b until it snaps into recess 29 under the influence of the locking plate biasing spring 55 as depicted by FIG. 4c. In this condition the upper Jacquard cams 19, which are spring biased upwardly but are normally restrained in their lower position by retaining flange 31 of lever 21, are permitted to be spring-urged upwardly into their upper operative position. Since lever 32 has not been actuated, the lower Jacquard cams 20 are retained in their lower position by shoulders 41, 42 of lever 32. Stitch cams 48 and three-position cams 49 having been set as shown, a cam raceway for selected needles shown by arrows 47 is thus provided and a cam raceway identified by arrows 52 is provided for non-selected needles as may be observed from FIG. 6. The needles may, in an appropriate configuration, be selected by hand; or by cam as disclosed in the U.S. Pat. No. 3,063,270 of Schurich, Nov. 13, 1962; or by electromechanical means as taught in the U.S. Pat. No. 2,173,488 of Tandler, Sept. 19, 1939; or by a device having a memory means as disclosed in the U.S. Pat. No. 3,358,473 of Suzake, Dec. 19, 1967. The more exotic designs may be fashioned automatically with a device as disclosed by the latter patent, whereas a simple design may be easily implemented by hand, or by a cam 58 rotatable on stud 60, wherein every other needle is elevated by the lobes 59, of the cam as the carriage is moved across the needle bed, alternate needles passing between the lobes. It will be noted that the needles which follow the high path through the cam system are directed over the left-hand three-position cam 49, over the first of upper spring loaded Jacquard cams 19 and thence below the second upper Jacquard cam which guides the needles downwardly to a point at the top of the right-hand stitch cam 48, and thence out of the carriage. These selected needles will accept a thread, such as a nylon yarn, before they are guided downwardly by the right-hand stitch cam 48. Concurrently, the non-selected needles are guided over the left-hand stitch cam 48, which serves as a raise cam for the non-selected needles, and across the top of the lower Jacquard cams. These non-selected needles are raised to a level by the left-hand stitch cam 48 such that they accept a heavier yarn, preferably colored, and the aforementioned thread pulled down to a pickup position for the non-selected needles by selected needles already acted on by the right-hand stitch cam 48, before then joining the selected needles at approximately the same point on the right-hand stitch cam 48 where they are then guided downwardly to set the stitch before leaving the carriage the transfer of a yarn from the hook of a high level needle to one at a low level is best shown in U.S. Pat. No. 3,748,873 on page 7, lines 35-65, where the yarn guides 52 and 53 are located at different levels to selectively transfer thread to needles following high or low level paths, designated as C' and B' in FIG. 5 of the drawings. In the instant case the selected needle having picked up a thread from a higher level is brought to a lower position by the right hand stitch cam whereby the hook of the non-selected needle can catch this thread before it is acted on by the right hand stitch cam 48 and brought to a position where its latch is closed.
In order to rearrange the cams so that the operator may then produce Fair Isle knitting it is merely necessary to depress cam control lever 32. As shown by FIG. 5a, actuation of the lever 32 results in lever movement substantially the same as described previously with respect to lever 21. Thus, as lever 32 moves upwardly, ramp 36 engages with lug 46 on the locking plate and forces the locking plate to the right against the bias of the locking plate spring 55. Lug 46 is forced out of recess 29 of lever 21 --thereby unlocking lever 21. The lug then moves downwardly along ramp 36 of cam control lever 32 and into recess 37 thereof to lock both of cam control levers 21 and 32 into their upper operative positions and thereby permitting both of the upper and lower Jacquard cams 19 and 20 to shift upwards under the influence of their springs to adopt an upper operative locked position. When so positioned, as may be seen from FIG. 7, the selected needles follow the high path through the cam system as described in connection with the cam alignment for Punch Lace. However, the non-selected needles will follow the lower path over the left-hand stitch cam, which serves as a raise cam, over the left-hand lower Jacquard cam 20 and under the right-hand lower Jacquard cam 20 to be directed to a lower point on the right-hand stitch cam 48 than where the selected needles join said stitch cam. The non-selected and selected needles are then directed out of the carriage. In this Fair Isle cam configuration the high path needles will accept a first yarn before passing through the upper Jacquard cams 19 whereas the lower path needles will accept a second yarn before passing through the lower Jacquard cams 20.
In order to convert the cam system from the Fair Isle pattern configuration to an arrangement whereby a stocking knit can be produced, it is merely necessary to shift the three-position cams 49 to the appropriate position by a different setting of needle return buttons 16 and 17. There is no need to vary the position of either the upper or lower Jacquard cams 19 and 20. As is well known in the art the Jacquard cams are ineffective during a stocking knit since all needles are directed by the three position cams 49 into a path beneath the upper Jacquard cams 19. The lower Jacquard cams 20 are spring loaded as previously noted and are deflected away by needle passage thereby as is shown in FIG. 7. The upper Jacquard cams 19 are not utilized inasmuch as there in so requirement for high pass needles. Stocking knit refers to Jersey knit, i.e. a basic knit fabric. It will, of course, be appreciated that with levers 21 and 32 both in a non-actuated state it is simply necessary to actuate lever 32 in order to shift both sets of Jacquard cams to their upper positions to thereby produce Fair Isle knitting. In such event flange 31 of lever 21 is engaged by the upper terminus of lever 32 and lever 21 is thus actuated concomitantly with lever 32.
From the foregoing it will be seen that there has been provided an interconnected Jacquard cam control lever system whereby upper and lower Jacquard cams 19 and 20 can be selectively positioned to achieve either Punch Lace or Fair Isle knitting, and that without any modification of the position of either of the Jacquard cams the operator can convert to stocking knit by simply re-positioning the three-position cams 49.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
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A carriage for a hand knitting machine in which a plurality of cams, including upper and lower Jacquard cams, are sequentially arranged and are adjustable between inoperative and operative positions so as to define at least one raceway for the butts of needles reciprocable in the needle bed of the machine. At least the upper and lower Jacquard cams are actuable by individually operable lever means between said inoperative and operative positions. At least one of the lever means is interconnected with at least one of the other lever means such that actuation of one of the said lever means simultaneously actuates at least one of the other lever means to thereby actuate a predetermined combination of said cams.
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BACKGROUND OF THE INVENTION
The invention relates to fluorescence spectrophotometric equipment and methods, particularly for making high-precision measurements in the determination of specimen response to a chemical, biological or physical agent wherein evaluation is made for a "control" sample of the specimen in relation to an "experimental" sample of the specimen.
U.S. Pat. Nos. 4,795,256 and 5,039,219 are illustrative of state-of-the-art precision fluorescence spectrophotometric equipment in which instrument sensitivity (e.g., as defined by signal/noise ratio) is high and cuvette-based fluorescence experiments are conventionally made, using one sample at a time. However, high-precision measurements do not necessarily yield meaningful and accurate results, particularly when one is concerned with the accuracy with which weak external influences on real-time kinetics of samples of biological cells are to be determined by fluorimetry. The accuracy of any experimental evaluation is limited by repeatability, that is, the extent to which a measurement with the same initial conditions (e.g., including the same biological state of the sample) will produce the same result. For example, when data from two or more consecutive fluorescence recordings (i.e., "experimental" and "control") are compared, it is generally assumed that the quantitative biological response patterns (i.e., kinetics) are the same. However, this may not always be the case, in that the false assumption of a constant cell response will be reflected in erroneously interpreted results. In other words, two separate recordings will differ, not because of imprecise measurements, but because the response kinetics may have changed in one or more significant ways. If a change in response kinetics is not accounted for, the change will factor into a measured fluorescence change, consequently prompting an inaccurate interpretation of results.
BRIEF STATEMENT OF THE INVENTION
It is an object of the invention to provide an improved method and apparatus for fluorescent spectroscopic examination of a specimen, wherein the above-noted inaccuracy can be eliminated or at least very substantially reduced.
It is a specific object to meet the above object with methodology whereby two or more samples of virtually identical biological response patterns can be analyzed simultaneously, whereby to achieve results that can be compared on a real-time basis.
Another specific object is to meet the above objects for the case of a dual-fluorescence analysis.
A further specific object is to provide an improved method and apparatus for fluorescent spectroscopic analysis whereby to achieve substantially greater accuracy and reproducibility of observations, particularly for cases in which the experimental specimen is subjected to a relatively weak chemical, biological or physical agent, such as a weak electromagnetic field.
It is also a specific object in a dual-beam dual-wavelength fluorescence system to make instrumental time resolution independent of any switching of light paths that may be involved in the measurement process.
A general object is to meet the above objects with apparatus which involves relatively little departure from what is commercially available, and which is inherently capable of performing a vastly greater number of experiments in a given time, as compared to prior techniques.
The invention in a preferred mode meets the above objects with what I believe to be a new quantitative fluorescence technique which I term differential real-time fluorescence spectroscopy (DRFS), pursuant to which one can simultaneously make time-resolved measurement of fluorescence changes in two cuvette samples (e.g., experimental and control), wherein the fluorescence is induced by excitation light, and wherein both samples have been identically prepared with a selected ratiometric dye. The ratiometric dye may either be of excitation-shifted variety or of emission-shifted variety. With DRFS, it is possible to monitor the response of specimen cells to a chemical, biological or physical agent, in the absence and in the presence of a selected experimental variable, and to determine both of these responses in real time, i.e., at the same time as the measurements are being made. The invention is therefore ideally suited to monitor response from experimental stimuli that are expected to induce only relatively small cellular changes during the typical time course of a fluorescence measurement, namely, 20 minutes or less. The reason for this capability is that DRFS eliminates problems attributable to inherent biological variability associated with preparations of living cells, such as known and unknown (e.g., time-dependent) changes in base-line biological activity during the storage or handling of prepared cells, prior to and awaiting a particular experiment.
By way of illustration, actual use of the invention will be described for an investigation of the dose-dependent acute effects of an inhibiting drug on stimulus-induced increases in intracellular calcium levels [Ca 2+ ] i , in human leukemic T-lymphocyte cells.
DETAILED DESCRIPTION
Preferred and other embodiments of the invention will be described in detail, in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram schematically showing optical and electrical components of a preferred embodiment of the invention, for the case of using an excitation-shifted ratiometric dye in dual-wavelength excitation measurements;
FIG. 2A is graphical recording made in use of the embodiment of FIG. 1, showing, in real time, measured fluorescence for identical "control" and "experimental" specimens as a function of the same time scale, and for the illustrative case of subjecting the experimental specimen to a relatively weak concentration of an inhibitory drug;
FIG. 2B is a recording similar to that of FIG. 2A, for case of a doubled concentration of the inhibitory drug;
FIG. 3 is a diagram similar to FIG. 1, to illustrate application of the invention to real-time dual-wavelength fluorescence observation of a greater plurality of specimens;
FIG. 4 is a diagram similar to FIG. 1 for another embodiment of the invention, for the case of using an emission-shifted ratiometric dye for dual-wavelength emission measurements;
FIG. 5 is a diagram similar to FIG. 1 for a modification of FIG. 1, for making dual-wavelength excitation measurements using an excitation-shifted dye; and
FIG. 6 is a diagram similar to FIG. 5 for a modification wherein dual-wavelength emission measurements are made using an emission-shifted ratiometric dye.
Referring initially to FIG. 1, the invention is shown as a dual-wavelength fluorescence spectrophotometric system for concurrently comparatively analyzing two identical specimens, respectively contained and supported in identical cuvettes 10, 11 in separate chambers 12, 13. Preparation of the specimens will be understood to have included a ratiometric fluorescent dye that will have been selected for the purposes of a particular experiment. In the present illustrative situation, changes in intracellular calcium concentration [Ca 2+ ] i will be assumed to be important to the experiment, and the dye Fura-2 will be assumed to have been selected for the purpose. Fura-2 is a well-known excitation-shifted dye suitable for detection of calcium; it is commercially available from Molecular Probes, Inc., Eugene, Oreg. Fura-2 is one of a variety of excitation-shifted dyes; it has the property of responding to excitation in one or both of two spaced relatively narrow bandwidths that are respectively centered at 340-nm and 380-nm, with fluorescence emission at 510-nm.
The chambers 12 (13) are identical, each having an inlet-porting alignment for exposing its cuvette 10 (11) to excitation light from an optical-fiber cable 14 (15), and an outlet-porting alignment for delivery of resultant fluorescent light to a photon detection device 16 (17) to measure fluorescent output. The designations PMT at 16 (17) will be understood to apply for devices which measure fluorescent output in the exiting beam from each of the respective chambers. Further symbolism within chambers 12 (13) will be understood illustratively to include identical coils 18 (19) for generating magnetic fields, identical thermostatically controlled cooling/heating systems 20 (21), and identical optical systems such as concave mirrors 22 (23) for more efficient direction of fluorescent-light output to the respective PMT's at 16 (17). In the labeling of the PMT's, parenthetical reference at 16 to "control" and at 17 to "EXP." (meaning "experimental") will be understood to designate the respective functional purposes of the identically prepared specimens at cuvettes 10, 11.
In accordance with an important feature of the invention, the lines 14, 15 of optical-fiber connection to chambers 12, 13 are identical and are supplied with like shares of light at 340-nm and at 380-nm, in equally shared time-interlaced relation. As shown, such light originates with a source 25, which may be a Xenon-arc lamp, producing an output beam on an optical axis to a continuously rotated mirror chopper 26, for splitting the lamp beam into two beams 27, 28, in equally shared time-interlaced alternation. The chopped and unreflected light of beam 27 is shown restricted by a first filter F(340) to the Fura-2 excitation-wavelength band, centered at 340-nm, for delivery of the same via a first optical-fiber cable 29 to an optical device 30; and the chopped and reflected light of beam 28 is restricted by a second filter F(380) to the second Fura-2 excitation-wavelength band, centered at 380-nm, for delivery of the same via a second optical-fiber cable 31 to the optical device 30. Cables 29, 31 are preferably of equal length and contain identical quantities of like optical fibers; cables 29, 31 may be the two branches of a single bifurcated fiber-optics bundled assembly. Similarly, the optical-fiber cables 14, 15 which deliver excitation light to the respective specimens 10, 11 may be the two branches of another and identical bifurcated fiber-optics bundled assembly, in turn assembled back-to-back at 30 with the assembly for cables 29, 31. The function at optical connection 30 is to assure in each of the cables 14, 15 an equally divided share of excitation light from each of the cables 29, 31. Description of items related to excitation light in FIG. 1 is completed by identifying a light beam 32 between a local source and a photocell 33, with interruption by chopper 26, whereby, with suitable amplification at 34, a signal is available in a synchronizing line 35, for purposes to be described. And a shutter 25' is suggested at the exit of light from source 25 to prevent incidence of excitation light on specimens at 10, 11, unless and until an experiment is being run.
The "control" PMT 16 will be seen to respond, for a specific calcium concentration, with a greater signal level for the chopped intervals of 340-nm exposure, in time-interlaced relation with a lesser signal level for the intervening chopped intervals of 380-nm exposure; in this connection, signal-to-noise at the excitation-shifted fluorescence wavelength 510-nm is enhanced by a suitable filter F(510). These PMT signals are then supplied to signal-processing means, collectively designated 36 for the "control" side of the system. Identical processing will be understood to exist for identical excitation on the "exp." side of the system, for which identical, duplicate signal-processing means is collectively designated 36'. The only difference between signals detected at PMT 16, as compared with those detected at PMT 17, is the fact of a selected one or more chemical, biological, or physical stimuli for the experimental-cuvette contents of chamber 13, as compared with the control-cuvette contents of chamber 12.
As shown, "control" signal-processing means 36 comprises an electronic switch 37 operating from the chopper-synchronizing signal in line 35. Switch 37 separates the time-interlaced signals, supplying to a first processing circuit 38 the segregated 510-nm fluorescent response to 340-nm excitation, and supplying to a second processing circuit 39 the segregated 510-nm fluorescent response to 380-nm excitation; suitably and preferably, the processing at 38, 39 includes analog/digital conversion, so that ensuing functions can be digitally processed. Output of the respective circuits 38, 39 is connected to a quotient-determining circuit 40, whereby the ratio of the signal which reflects response to 340-nm excitation, in relation to the signal which reflects response to 380-nm excitation is available for recording of the indicated "control" ratio, as a function of time in the on-going course of a given experiment. Identical signal-processing components for the "experimental" signals detected by PMT 17 need no further description and are therefore given the same reference numbers, with primed notation; the net result is that an "experimental"-signal ratio output from circuit 40' which also reflects response to 340-nm excitation, in relation to the signal which reflects response to 380-nm excitation, is available for recording of the indicated "experimental" ratio, as a function of the same time scale as the "control" ratio, in the same on-going course of the experiment. In FIG. 1, a single display means 41 is shown connected for simultaneous display and/or storage of involved "control" and "experimental" ratio determinations in real time.
FIGS. 2A and 2B are illustrative recordings made simultaneously and on a real-time basis, for a "control" signal ratio (CTR) and an "experimental" signal ratio (EXP), wherein Fura-2 was the excitation-shifted dye used in the apparatus of FIG. 1, and wherein the traces shown in these FIGS. 2A and 2B are the raw-processed data available at the control/experimental display 41 of FIG. 1.
FIGS. 2A and 2B represent the time-evolution of the intracellular calcium concentration in Fura-2-loaded human leukemic T-lymphocyte cells (JURKAT-clone E6-1), wherein the displayed evolution proceeds in the time period 0 to 900 seconds, and wherein an increase in the ratio F340/F380 signifies an increase in intracellular calcium concentration in the T-lymphocyte cells, the same being suspended in a physiological buffer solution.
More specifically, in both FIGS. 2A and 2B, the time period 0 to 300 seconds reflects the base-line calcium levels in both the "experimental" and the "control" T-lymphocyte cell suspensions at cuvettes 10, 11, respectively. At time 300 seconds, a dose of a calcium-flux inhibitory drug, ECONAZOLE (0.25 μM in FIG. 2A, and 0.50 μM in FIG. 2B) was added, exclusively to the "experimental" cuvette sample 11; such doses will be observed not to lead to baseline deviations, as between the "experimental" and the "control" samples at 10 and 11. Then, at time 420 seconds, a "stimulus" applied equally to both the cell suspensions at 10, 11, was administered; the stimulus was "THAPSIGARGIN" at a concentration of 0.1 μM. This stimulus induced a rapid increase in intracellular calcium concentration in the involved cells, characterized by a peak at approximately 500 seconds, followed by a decline to essentially a plateau at about 900 seconds. FIGS. 2A and 2B illustrate the very noticeable difference in this peak attributable to the inhibitory drug, not only in the comparisons against the "control" response but also as a function of having doubled the drug concentration in the experiment of FIG. 2B. It is notable that even the influence of relatively weak drug administration on the stimulus-induced calcium-concentration rise (FIG. 2A) can be clearly discerned, by the dual-beam, dual-wavelength fluorescence spectrophotometric technique involved in a single experimental run with the apparatus of FIG. 1.
The system of FIG. 3 will be seen as having great similarity to FIG. 1, with the exception that FIG. 3 illustrates that the invention is equally applicable to simultaneous real-time observation and measurement of plural specimens when the plurality exceeds two. The only limitation to the number of simultaneously observed specimens is that sufficient excitation-light flux shall be available from source 25, after spectral restriction to F(340) and F(380) distribution, with equally shared fractions of F(340) and F(380) light, divided at optical connection 30' into each of a plurality of optical-fiber cable branches 14', 15' and 15", serving plural prepared specimens at cuvettes 10, 11' and 11" in chambers 12, 13' and 13". Legends at the single display means 41 indicate the capability of concurrently responding to the ratio output of signal-processing means 36 for the fluorescent output of the control specimen at 10, as well as (i) the ratio output of signal-processing means 36' for the fluorescent output of a first or Experiment-A specimen at 11', and (ii) the ratio output of signal-processing means 36" for the fluorescent output of a second or Experiment-B specimen at 11". In each of these three cases, the prepared specimens may illustratively have been identical, and the only difference in the course of a given run may, for example, be in the concentration of an added chemical agent, or the strength of an ambient electrical or magnetic field, as between Experiment A and Experiment B. A further reference numeral 15 n applied to a fragmentary phantom optical-fiber cable branch will be understood to indicate further equal sharing (at 30') of the time-interlaced dual-wavelength excitation light, to serve up to N experiments at a time, with processing identical to what has been described for Experiments A and B. And a legend applicable to an arrow in connection with display 41 is indicative of the fact that all processed experiments (A to N), plus the processed control signal can be presented comparatively, in real time and to the same time scale. As noted above, the limiting number of such further simultaneous experiments or measurements will depend upon whether the equal-sharing operation at 30' will deliver to each specimen sufficient light flux (at both of wavelengths 340-nm and 380-nm) to stimulate meaningful fluorescence at 510-nm (for each of the excitation wavelengths, 340-nm and 380-nm).
The system of FIG. 4 illustrates use of the invention in a mode wherein dual-wavelength fluorescence results from use of an emission-shifted dye, which may be Indo-1, for observation of intracellular calcium [Ca 2+ ] i in a biological specimen. In an emission-shifted dye for dual-wavelength emission measurements, and for the case of Indo-1 in particular, a single narrow band of excitation light (centered at 350-nm) will develop fluorescent emission at two spaced narrow bands (centered at 425-nm and at 490-nm, respectively). Functional components in FIG. 4 therefore utilize these wavelength numbers for Indo-1 to designate functional relation to one or more of these wavelengths in a typical use of a ratiometric emission-shifted dye for dual-wavelength emission measurements, which in the case of FIG. 4 (as in FIG. 1) result in real-time development and display and/or storage of "control" and "experimental" ratio signals.
In the emission-shifted situation of FIG. 4, source 25 is required, in connection with a single filter F(350), to deliver only a single narrow band of excitation light to a single bifurcated optical-fiber bundle 45, with provision for equally shared delivery via branches 46, 47 to "control" and to "experimental" specimens at cuvettes 10, 11, within chambers 12, 13 as described in connection with FIG. 1. This may be done by direct and continuous delivery of light from source 25, via filter F(350), to the inlet end of the bifurcated fiber bundle 45; but in the form shown, preference is indicated that this delivery be made via chopper 26, with which other switching means as at 26', are synchronized, for signal-to-noise enhancement purposes; in FIG. 4, the legends "sync." applied at 26 and 26' will be understood to symbolize such synchronism.
In view of the dual-wavelength emission nature of Indo-1 dye used in specimens at 10, 11 in FIG. 4, the exiting fluorescent beams 48, 49 which issue from chambers 12 and 13 are each characterized by the two narrow bands centered at 425-nm and at 490-nm, respectively. Beams 48, 49 are shown folded at mirrors 43, 44 and split at 50, 50' into two spaced axes for narrow-band filtering at F(425) and at F(490), prior to separate measurement at 51 (PMT 425) and 52 (PMT 490) of "control" specimen fluorescence, and prior to separate measurement at 51' (PMT 425) and 52' (PMT 490) of "experimental" specimen fluorescence. Gate-26' controlled signal processing at 53, 54 of the respective PMT 425 and PMT 490 detected "Control" outputs at 51, 52 sets the stage for development at 55 of a ratio signal reflecting the instantaneous relative magnitude of "control" specimen fluorescence at the dual wavelengths attributable to use of Indo-1, and the ratio signal for the "control" specimen is supplied directly and continuously to display/storage means 56. Concurrently, gate-26' controlled signal processing at 53', 54' of the respective PMT 425 and PMT 490 detected "experimental" outputs at 51', 52' sets the stage for development at 55' of a ratio signal reflecting the instantaneous relative magnitude of "experimental" specimen fluorescence at the dual wavelengths attributable to use of Indo-1, and the ratio signal for the "experimental" specimen is supplied directly and continuously to display/storage means 56, for display with the "control" ratio signal and to the same time scale. The plotted display at 56 will be like that of FIGS. 2A and 2B, all other conditions being analogous, except for the fact of using an emission-shifted dye in FIG. 4, in place of an excitation-shifted dye in FIG. 1.
The system of FIG. 5 will be recognized for its correspondence to that of FIG. 1, except for use in FIG. 5 of a single chamber 60 to contain two identical cuvette specimens at 61, 62, for concurrent exposure to time-interlaced delivery of 340-nm excitation light in alternation with 380-nm excitation light, all as described for FIG. 1. For this reason, the same reference numbers are adopted in FIG. 5 as in FIG. 1 and no further separate discussion is needed, beyond pointing out that in chamber 60 of FIG. 5 there are two spaced inlet ports and two spaced outlet ports, with a light barrier 63 between cuvette specimens, for assurance against internally scattered "cross-talk" between "control" specimen fluorescence and "experimental" specimen fluorescence. Finally, the rectangular outline 64 around both cuvette specimens will be understood to indicate provision for thermostatically controlled uniform thermal environmental conditions for both specimens.
The system of FIG. 6 illustrates that the single chamber 60 of FIG. 5, containing plural cuvette specimens at 61, 62, is equally adaptable to use with an emission-shifted ratiometric dye (such as Indo-1) as such a single chamber was described in FIG. 5 for use with an excitation-shifted dye. This being the case, it is suitable in FIG. 6 to borrow from FIG. 4 most of the components described and shown in connection with involved emission-shifted fluorescence. Accordingly, where appropriate, the same reference numbers are used in FIG. 6 for components and functions as in FIG. 4, and further discussion is unnecessary.
It will be seen that the presently described techniques and apparatus meet the above-stated objects and provide substantial advantages over past and present techniques; these advantages include but are not limited to the following:
1. Problems associated with sequential measurements on a given specimen are eliminated by the simultaneous nature and real-time analysis provided by the invention.
2. The invention significantly reduces the time required for analysis of the effect of a given agent on a specific specimen, thus vastly improving efficiency of the measurement process.
3. For many applications, e.g., not involving magnetic-field experiments, the invention can be fully served by plural cuvette samples in a single chamber; and the use of separate chambers, i.e., one cuvette sample in each chamber, enables the efficient real-time analysis and measurement of the effect of a magnetic field on a given sample, in real-time comparison to a "control" sample which is not exposed to a magnetic field.
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A quantitative fluorescence technique is presented as "differential real-time fluorescence spectroscopy" (DRFS), pursuant to which one can simultaneously make time-resolved measurement of fluorescence changes in two cuvette samples (e.g., experimental and control), wherein the fluorescence is induced by excitation light, and wherein both samples have been identically prepared with a selected ratiometric dye. The ratiometric dye may either be of excitation-shifted variety or of emission-shifted variety. With DRFS, it is possible to monitor the response of specimen cells to a chemical, biological or physical agent, in the absence and in the presence of a selected experimental variable, and to determine both of these responses in real time, i.e., at the same time as the measurements are being made. The invention is therefore ideally suited to monitor response from experimental stimuli that are expected to induce only relatively small cellular changes during the typical time course of a fluorescence measurement, namely, 20 minutes or less. The reason for this capability is that DRFS eliminates problems attributable to inherent biological variability associated with preparations of living cells, such as known and unknown (e.g., time-dependent) changes in base-line biological activity during the storage or handling of prepared cells, prior to and awaiting a particular experiment.
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FIELD OF THE INVENTION
[0001] The present invention relates to inventive branched blocky cationic organopolysiloxane compounds. It also relates to consumer product compositions comprising the inventive compounds and to methods of making and use.
BACKGROUND OF THE INVENTION
[0002] Cationic conditioning polymers meant for deposition onto negatively charged surfaces, such as fabric, skin, or hair, are included in many common consumer product compositions. Such products can provide consumer-desired benefits such as softness, lubricity, hand, anti-wrinkle, hair conditioning, frizz control, skin moisturization, and color protection. The effectiveness of any particular conditioning polymer depends not only upon the chemical and physical properties of the conditioning polymer itself, but also upon those of the targeted surface and the product formulation in which the conditioning polymer is delivered.
[0003] Many consumer products containing cationic conditioning polymers are in the form of aqueous-based rinse-off compositions, such as hair shampoos, body washes, laundry detergents, and fabric softeners. Despite the popularity of these rinse-off compositions, such product forms frequently experience difficulties effectively depositing these cationic conditioning polymers, which are typically hydrophobic, onto the target surfaces. Incorporating these conditioners into aqueous-based products often results in the conditioner being preferentially rinsed away from the intended site of deposition, rather than effectively deposited. This problem is particularly pronounced in the context of cleansing compositions containing surfactant, especially those containing anionic surfactant.
[0004] Anionic surfactants can interfere with deposition by forming complexes/precipitates with the cationic conditioning polymers. The higher the concentration of anionic surfactant, the more difficult it becomes to deposit cationic benefit actives. This leads to non-cost-effective use and waste of materials. Further, even if an acceptable level of deposition is attained, these formulations may lack shelf-stability due to flocculation and precipitation, making them unacceptable as consumer products.
[0005] Several materials exist in the art, but are not wholly satisfactory. For example, the material described by Ono (WO 99/32539) comprises functionalized end groups having heteroatoms such as oxygen, nitrogen, sulfur, or halogens. These functionalized end groups can lead to undesirable reactions that pose stability issues for compositions comprising these materials. For instance, Ono's silicones can react further through these end groups, leading to further condensation and/or polymerization of the silicones in the compositions during storage. Also known in the art are quaternized silicones that include alkylene oxide units, such as those described by Masschelein (U.S. Pat. No. 6,903,061). The quaternized silicones described by Masschelein may be too water soluble for a given application, and thus can have a reduced capacity as conditioning polymers, since these materials tend to partition into water at a higher than desired level rather than deposit on the target substrate. Further, when these materials are used as the conditioning active, they can have an undesirable feel because of their high permeability to water and water vapor. Additionally, because of the potential for variability in the alkylene oxide moiety, these materials can be difficult to formulate reproducibly. This can limit the desired degree of functionality in a silicone material. It would desirable to have a material the provides greater flexibility via the level of quaternization. Similarly, the ethoxylated quaternized silicone materials disclosed by Boutique (U.S. Pat. No. 6,833,344) suffer from many of the same inadequacies of those described by Masschelein.
[0006] There is still a need to provide cationic conditioning polymers that are suitable for use in a wide range of consumer product applications. The present invention provides cationic conditioning polymers and consumer product compositions comprising conditioning polymers that can effectively deposit and provide conditioning benefits to negatively charged substrates while avoiding the aforementioned disadvantages.
SUMMARY OF THE INVENTION
[0007] The present invention attempts to solve one or more of the aforementioned needs by providing, in one aspect, inventive branched blocky cationic organopolysiloxanes that are suitable for use in a wide range of consumer product compositions. The inventive compounds are functionalized to favorably interact with the targeted substrate and product composition to deliver desired deposition and conditioning benefits, as well as desired shelf-stability.
[0008] Without being bound by theory, when cationic charge that could otherwise facilitate hydrophobic benefit agent deposition is randomly distributed along the length of the benefit agent polymer, the charge can be too highly dispersed to adequately facilitate deposition. The inventive polymer's charge density can be custom-tailored (e.g., higher charge density) to enhance deposition and conditioning performance in different use environments. Further, by varying the inventive polymer's level of hydrophobic substitution and/or the degree of ethoxylation, propoxylation, and alkoxylation, the inventive polymer can be formulated into a desirably stable composition for a variety of use environments. By controlling charge density and hydrophobic substitution and/or degree of ethoxylation, propoxylation, and more generally alkoxylation, the inventive compounds can be custom-tailored for a variety of product formulations and uses.
[0009] The current invention further solves the aforementioned needs by providing branching in the cationic portion of the cationic organopolysiloxane polymer. Without being bound by theory it is felt that the branching in the cationic portion of the cationic organopolysiloxane provides for a further increase in the charge density of the cationic portions thereby increasing the deposition efficiency of the cationic organopolysiloxane.
DETAILED DESCRIPTION OF THE INVENTION
I. Definitions
[0010] As used herein, the “branched blocky cationic organopolysiloxane” may also be referred to as the “organopolysiloxane”.
[0011] As used herein “consumer product” means baby care, personal care, fabric & home care, family care (e.g., facial tissues, paper towels), feminine care, health care, beauty care and like products generally intended to be used or consumed in the form in which they are sold. Such products include but are not limited to diapers, bibs, and wipes; products for and/or methods relating to treating hair (human, dog, and/or cat), including, bleaching, coloring, dyeing, conditioning, shampooing, styling; deodorants and antiperspirants; personal cleansing; cosmetics; skin care including application of creams, lotions, and other topically applied products for consumer use including fine fragrances; and shaving products, products for and/or methods relating to treating fabrics, hard surfaces and any other surfaces in the area of fabric and home care, including: air care including air fresheners and scent delivery systems, car care, dishwashing, fabric conditioning (including softening and/or freshening), laundry detergency, laundry and rinse additive and/or care, hard surface cleaning and/or treatment including floor and toilet bowl cleaners, and other cleaning for consumer or institutional use; products and/or methods relating to bath tissue, facial tissue, paper handkerchiefs, and/or paper towels; tampons, feminine napkins; products and/or methods relating to oral care including toothpastes, tooth gels, tooth rinses, denture adhesives, and tooth whitening.
[0012] As used herein, the term “cleansing and/or treatment composition” is a subset of consumer products that includes, unless otherwise indicated, personal care, fabric care, and home care products. Such products include, but are not limited to, products for treating hair (human, dog, and/or cat), including, bleaching, coloring, dyeing, conditioning, shampooing, styling; deodorants and antiperspirants; personal cleansing; cosmetics; skin care including application of creams, lotions, and other topically applied products for consumer use including fine fragrances; and shaving products, products for treating fabrics, hard surfaces and any other surfaces in the area of fabric and home care, including: air care including air fresheners and scent delivery systems, car care, dishwashing, fabric conditioning (including softening and/or freshening), laundry detergency, laundry and rinse additive and/or care, hard surface cleaning and/or treatment including floor and toilet bowl cleaners, granular or powder-form all-purpose or “heavy-duty” washing agents, especially cleaning detergents; liquid, gel or paste-form all-purpose washing agents, especially the so-called heavy-duty liquid types; liquid fine-fabric detergents; hand dishwashing agents or light duty dishwashing agents, especially those of the high-foaming type; machine dishwashing agents, including the various tablet, granular, liquid and rinse-aid types for household and institutional use; liquid cleaning and disinfecting agents, including antibacterial hand-wash types, cleaning bars, mouthwashes, denture cleaners, dentifrice, car or carpet shampoos, bathroom cleaners including toilet bowl cleaners; hair shampoos and hair-rinses; shower gels, fine fragrances and foam baths and metal cleaners; as well as cleaning auxiliaries such as bleach additives and “stain-stick” or pre-treat types, substrate-laden products such as dryer added sheets, dry and wetted wipes and pads, nonwoven substrates, and sponges; as well as sprays and mists all for consumer or/and institutional use; and/or methods relating to oral care including toothpastes, tooth gels, tooth rinses, denture adhesives, tooth whitening. The care agents can advantageously be used in household polishes and cleaners for floors and countertops to provide benefits such as enhanced shine. Care agents in fabric softeners can help preserve “newness” because of their softening properties, and those having elasticity can help smooth out wrinkles. The care agents can also enhance shoe cleaning and polishing products.
[0013] As used herein, the term “personal care cleansing and/or treatment composition” is a subset of cleaning and treatment compositions that includes, unless otherwise indicated, products for treating hair, including, bleaching, coloring, dyeing, conditioning, shampooing, styling; deodorants and antiperspirants; personal cleansing; cosmetics; skin care including application of creams, lotions, and other topically applied products for consumer use including fine fragrances; and shaving products; liquid cleaning and disinfecting agents including antibacterial hand-wash types, cleaning bars, mouthwashes, denture cleaners, and dentifrice cleaners; hair shampoos and hair-rinses; shower gels, fine fragrances, and foam baths; substrate-laden products such as dry and wetted wipes and pads, nonwoven substrates, and sponges; as well as sprays and mists all for consumer or/and institutional use; and/or methods relating to oral care including toothpastes, tooth gels, tooth rinses, denture adhesives, and tooth whitening.
[0014] As used herein, the term “fabric and/or hard surface cleansing and/or treatment composition” is a subset of cleaning and treatment compositions that includes, unless otherwise indicated, granular or powder-form all-purpose or “heavy-duty” washing agents, especially cleaning detergents; liquid, gel or paste-form all-purpose washing agents, especially the so-called heavy-duty liquid types; liquid fine-fabric detergents; hand dishwashing agents or light duty dishwashing agents, especially those of the high-foaming type; machine dishwashing agents, including the various tablet, granular, liquid and rinse-aid types for household and institutional use; liquid cleaning and disinfecting agents, including antibacterial hand-wash types, cleaning bars, car or carpet shampoos, bathroom cleaners including toilet bowl cleaners; and metal cleaners, fabric conditioning products including softening and/or freshening that may be in liquid, solid and/or dryer sheet form; as well as cleaning auxiliaries such as bleach additives and “stain-stick” or pre-treat types, substrate-laden products such as dryer added sheets, dry and wetted wipes and pads, nonwoven substrates, and sponges; as well as sprays and mists. All of such products, as applicable, may be in standard, concentrated or even highly concentrated form even to the extent that such products may in certain aspects be non-aqueous.
[0015] As used herein, articles such as “a” and “an” are understood to mean one or more of what is claimed or described.
[0016] As used herein, the terms “include”, “contain”, and “have” are non-limiting and do not exclude other components or features beyond those expressly identified in the description or claims.
[0017] As used herein, the terms “treatment agent”, “benefit agent”, “active”, “active agent”, and/or “care agent” and the like are used interchangeably to mean materials that can impart desirable aesthetic and/or functional properties (e.g., conditioning benefits such as softening or freshening) to a substrate. For example, the inventive organopolysiloxane polymer of the present invention can be used as a conditioning agent to impart conditioning benefits to substrates.
[0018] As used herein, the terms “conditioning agent” and “conditioning aid” are used interchangeably to refer to a material that delivers desirable conditioning effects (e.g., benefits such as softening or freshening) to a substrate. Conditioning agents are a type of treatment agent.
[0019] As used herein, the term “conditioning polymer” means a polymer that delivers desirable conditioning effects (e.g., softening or freshening) to a substrate.
[0020] As used herein, the term “substrate” is synonymous and used interchangeably with the terms “situs” and “surface”. Non-limiting examples of substrates include paper products, fabrics, garments, hard surfaces, hair, and skin.
[0021] As used herein, “targeted substrate” means a substrate, or the relevant portion of a substrate, upon which deposition is intended.
[0022] As used herein, a “deposition aid” is a material that assists another material (e.g., a benefit agent) to deposit (e.g., adhere) to a targeted substrate. The term “deposition aid” is broad enough to encompass both polymeric deposition aids (i.e. “deposition polymer”) and non-polymeric deposition aids.
[0023] As used herein, “adjunct” means an optional material that can be added to a composition to complement the aesthetic and/or functional properties of the composition.
[0024] As used herein, “auxiliary composition” refers to one or more compositions that when combined with a benefit agent emulsion of the present invention, form a consumer product composition. The auxiliary composition may be in the form of one or more ingredients or ingredient combinations.
[0025] As used herein, “carrier” means an optional material, including but not limited to a solid or fluid, that can be combined with a benefit agent (e.g., conditioning polymers) to facilitate delivery and/or use of the benefit agent.
[0026] As used herein, the term “solid” includes granular, powder, bar and tablet product forms.
[0027] As used herein, the term “fluid” includes liquid, gel, paste and gas product forms including unitized-dose forms that generally include a fluid composition enclosed in a pouch or other delivery vehicle.
[0028] As used herein, the term “particle” includes solid and semi-solid particles, as well as emulsion droplets.
[0029] Unless otherwise indicated, all percentages and ratios herein are calculated based on weight.
[0030] All percentages and ratios are calculated based on weight of the total composition unless otherwise indicated.
[0031] Unless specified otherwise, all molecular weights are given in Daltons.
[0032] Unless otherwise indicated, all molecular weights are weight average molecular weights as determined by size exclusion chromatography using a MALS detector (SEC-MALS), as is commonly known by those skilled in the art. A MALS detector (Multi-Angle Light Scattering Detector, such as those manufactured by Malvern Instruments Ltd., Malvern, UK) determines absolute molecular weight, rather than relative molecular weight (i.e., determined relative to a standard).
[0033] Unless otherwise noted, all component (i.e., ingredient) or composition levels are in reference to the active portion of that component or composition, and are exclusive of impurities, for example, residual solvents or by-products, which may be present in commercially available sources of such components or compositions.
[0034] The term “charge density”, as used herein, refers to the ratio of the number of positive charges on a monomeric unit of which a polymer is comprised, to the molecular weight of said monomeric unit. The charge density multiplied by the polymer molecular weight determines the number of positively charged sites on a given polymer chain. The charge density calculation can also be expressed as:
[0000]
charge
density
=
(
moles
of
N
)
(
charge
per
N
)
(
moles
of
polymer
)
(
molecular
weight
of
the
polymer
)
×
100
[0035] As used herein, the term “hydrocarbon polymer radical” means a polymeric radical comprising only carbon and hydrogen.
[0036] As used herein, “ethylene moiety” means a divalent CH 2 CH 2 moiety.
[0037] As used herein, the term “siloxyl residue” means a polydialkylsiloxane moiety.
[0038] As used herein, the nomenclature SiO n/2 represents the ratio of oxygen and silicon atoms. For example, SiO 1/2 means that, on average, one oxygen atom is shared between two silicon atoms. Likewise SiO 2/2 means that, on average, two oxygen atoms are shared between two silicon atoms and SiO 3/2 means that, on average, three oxygen atoms are shared between two silicon atoms.
[0039] As used herein, the terms “substantially no”, “substantially free of”, and/or “substantially free from” mean that the indicated material is at the very minimum not deliberately added to the composition to form part of it, or, preferably, is not present at analytically detectable levels. It is meant to include compositions whereby the indicated material is present only as an impurity in one of the other materials deliberately included.
[0040] It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.
II. Branched Blocky Cationic Organopolysiloxane Polymers
[0041] The present invention provides a branched blocky cationic organopolysiloxane having the formula:
[0000]
M
w
D
x
T
y
Q
z
[0000] wherein:
M is selected from the group consisting of [SiR 1 R 2 R 3 O 1/2 ], [SiR 1 R 2 G 1 O 1/2 ], [SiR 1 G 1 G 2 O 1/2 ], [SiG 1 G 2 G 3 O 1/2 ], and combinations thereof; D is selected from the group consisting of [SiR 1 R 2 O 2/2 ], [SiR 1 G 1 O 2/2 ], [SiG 1 G 2 O 2/2 ], and combinations thereof; T is selected from the group consisting of [SiR 1 O 3/2 ], [SiG 1 O 3/2 ], and combinations thereof; Q=[SiO 4/2 ]; w is an integer from 1 to about (2+y+2z); x is an integer from about 5 to about 15,000; y is an integer from 0 to about 98; z is an integer from 0 to about 98; R 1 , R 2 and R 3 are each independently selected from the group consisting of H, OH, C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, C 6 -C 32 substituted alkylaryl, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy, C 1 -C 32 alkylamino, and C 1 -C 32 substituted alkylamino; and wherein at least one of M, D, and T incorporates at least one moiety G 1 , G 2 or G 3 and G 1 , G 2 , and G 3 are same or different moieties each of which has the formula:
[0000]
wherein:
N is a nitrogen atom; Each R 4 is independently selected from the group consisting of H,
[0000]
C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, and C 6 -C 32 substituted alkylaryl;
Each X comprises a divalent radical selected from the group consisting of C 1 -C 32 alkylene, C 1 -C 32 substituted alkylene, optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 5 -C 32 or C 6 -C 32 arylene, C 5 -C 32 or C 6 -C 32 substituted arylene, C 6 -C 32 arylalkylene, C 6 -C 32 substituted arylalkylene, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino, ring-opened epoxide and ring-opened glycidyl;
Each E comprises the same or different divalent radicals selected from the group consisting of C 1 -C 32 alkylene, C 1 -C 32 substituted alkylene, alkylene, optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 5 -C 32 or C 6 -C 32 arylene, C 5 -C 32 or C 6 -C 32 substituted arylene, C 6 -C 32 arylalkylene, C 6 -C 32 substituted arylalkylene, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino, ring-opened epoxide and ring-opened glycidyl;
Each R 5 is independently selected from the group consisting of H, C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, and C 6 -C 32 substituted alkylaryl;
With the proviso that at least one Nitrogen-atom within at least one moiety G 1 , G 2 or G 3 has at least 2 R 4 selected to be
[0000]
And wherein:
Each m is an integer independently selected from 2 to 100,
Each n is an integer independently selected from 1 or 2,
And when an organopolysiloxane portion of a moiety G 1 , G 2 , G 3 is positively charged, A −t is a suitable charge balancing anion or anions such that the total charge of all occurances of the charge-balancing anion or anions, A −t and kA −t , is equal to and opposite from the net charge on the organopolysiloxane portions of the moiety G 1 , G 2 or G 3 .
[0063] It would be appreciated by one of ordinary skill in the art that:
[0064] A is an anionic counter ion to the positively charge organopolysiloxane,
[0065] t is the charge on any individual counter ion, and
[0066] k is the coefficient of any such counterion
[0000] so that the net charge of the positively charge organopolysiloxane and the sum total of the counter ions is neutral.
[0067] In one aspect, the counter ion or ions A −t is selected from the group consisting of Cl—, Br—, I—, methylsulfate, toluene sulfonate, carboxylate, phosphate, hydroxide, acetate, formate, carbonate, nitrate, and combinations thereof.
In one aspect of the present invention, the at least one Nitrogen-atom within at least one moiety G 1 , G 2 or G 3 that has at least 2 R 4 selected to be
[0000]
[0000] is adjacent a moiety X.
In one aspect of the present invention, the at least one Nitrogen-atom within at least one moiety G 1 , G 2 or G 3 that has at least 2 R 4 selected to be
[0000]
[0000] is adjacent a moiety E.
In one embodiment, the branched blocky cationic organopolysiloxane has the formula:
[0000]
M
w
D
x
T
y
Q
z
M is [SiR 1 R 2 G 1 O 1/2 ],
D is [SiR 1 R 2 O 2/2 ],
w is 2,
x is an integer from about 40 to about 1000,
y and z are each 0,
R 1 , R 2 and are independently selected from the group consisting of H, OH, C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, C 6 -C 32 substituted alkylaryl, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy,
G 1 has the formula:
[0000]
wherein:
Each X comprises a divalent radical selected from the group consisting of C 1 -C 32 alkylene, C 1 -C 32 substituted alkylene, optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 5 -C 32 or C 6 -C 32 arylene, C 5 -C 32 or C 6 -C 32 substituted arylene, C 6 -C 32 arylalkylene, C 6 -C 32 substituted arylalkylene, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino, ring-opened epoxide and ring-opened glycidyl;
N is a nitrogen atom;
Each R 4 is independently selected from the group consisting of H,
[0000]
C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, and C 6 -C 32 substituted alkylaryl;
Each E comprises the same or different divalent radicals selected from the group consisting of C 1 -C 32 alkylene, C 1 -C 32 substituted alkylene, alkylene, optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 5 -C 32 or C 6 -C 32 arylene, C 5 -C 32 or C 6 -C 32 substituted arylene, C 6 -C 32 arylalkylene, C 6 -C 32 substituted arylalkylene, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino, ring-opened epoxide and ring-opened glycidyl;
Each R 5 is independently selected from the group consisting of H, C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, and C 6 -C 32 substituted alkylaryl;
With the proviso that at least one Nitrogen-atom within at least one moiety G 1 , G 2 or G 3 has at least 2 R 4 selected to be
[0000]
And wherein:
Each m is an integer independently selected from 2 to 100,
Each n is an integer independently selected from 1 or 2,
And when an organopolysiloxane portion of a moiety G 1 , G 2 , G 3 is positively charged, A −t is a suitable charge balancing anion or anions such that the total charge of all occurances of the charge-balancing anion or anions, A −t and kA −t , is equal to and opposite from the net charge on the organopolysiloxane portions of the moiety G 1 , G 2 or G 3
It would be appreciated by one of ordinary skill in the art that: A is an anionic counter ion to the positively charge organopolysiloxane, t is the charge on any individual counter ion, and k is the coefficient of any such counterion
so that the net charge of the positively charge organopolysiloxane and the sum total of the counter ions is neutral.
In one embodiment, the branched blocky cationic organopolysiloxane has the formula:
[0000]
M
w
D
x
T
y
Q
z
M is [SiR 1 R 2 O 1 O 1/2 ],
D is [SiR 1 R 2 O 2/2 ],
W is 2,
x is an integer from about 40 to about 1000,
y and z are each 0,
R 1 , R 2 and are each, independently, selected from the group consisting of H, OH, C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, C 6 -C 32 substituted alkylaryl, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy, G 1 has the formula:
[0000]
wherein
Each R 4 is independently selected from the group consisting of H,
[0000]
[0000] C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, and C 6 -C 32 substituted alkylaryl; wherein:
X comprises a divalent radical selected from the group consisting of C 1 -C 32 alkylene, C 1 -C 32 substituted alkylene, optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 5 -C 32 or C 6 -C 32 arylene, C 5 -C 32 or C 6 -C 32 substituted arylene, C 6 -C 32 arylalkylene, C 6 -C 32 substituted arylalkylene, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino, ring-opened epoxide and ring-opened glycidyl; N is a nitrogen atom; R 5 is selected from the group consisting of H, C 1 -C 32 alkyl, C 1 -C 32 substituted alkyl, C 5 -C 32 or C 6 -C 32 aryl, C 5 -C 32 or C 6 -C 32 substituted aryl, C 6 -C 32 alkylaryl, and C 6 -C 32 substituted alkylaryl optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino; Each E comprises same or different divalent radicals selected from the group consisting of C 1 -C 32 alkylene, C 1 -C 32 substituted alkylene, alkylene, optionally interrupted with a hetero atom selected from the group consisting of P, N and O, C 5 -C 32 or C 6 -C 32 arylene, C 5 -C 32 or C 6 -C 32 substituted arylene, C 6 -C 32 arylalkylene, C 6 -C 32 substituted arylalkylene, C 1 -C 32 alkoxy, C 1 -C 32 substituted alkoxy, C 1 -C 32 alkyleneamino, C 1 -C 32 substituted alkyleneamino, ring-opened epoxide and ring-opened glycidyl; With the proviso that at least one Nitrogen-atom within at least one moiety G 1 , G 2 or G 3 has at least 2 R 4 selected to be
[0000]
And wherein:
Each m is an integer independently selected from 2 to 100,
Each n is an integer independently selected from 1 or 2,
And when an organopolysiloxane portion of a moiety G 1 , G 2 , G 3 is positively charged, A −t is a suitable charge balancing anion or anions such that the total charge of all occurances of the charge-balancing anion or anions, A −t and kA −t , is equal to and opposite from the net charge on the organopolysiloxane portions of the moiety G 1 , G 2 or G 3 .
It would be appreciated by one of ordinary skill in the art that: A is an anionic counter ion to the positively charge organopolysiloxane, t is the charge on any individual counter ion, and k is the coefficient of any such counterion
so that the net charge of the positively charge organopolysiloxane and the sum total of the counter ions is neutral.
III. Methods of Making the Branched Blocky Cationic Organopolysiloxane
[0113] Embodiments of the present invention can be made as follows. An amount of functional silicone is added to a clean vessel under inert atmosphere. The functional silicone may be an amino functional silicone or a silicone with an organic group capable of reacting with an amino function, examples of organic groups capable of reacting with an amino function include halogen functional silicones or epoxy functional silicones. Optionally, a solvent such as isopropanol or tetrahydrofuran is added. The reaction is optionally mixed and quantities of diamine and difunctional organic compounds capable of reacting with the amino functions of the amine compounds are added, either simultaneously or sequentially. For example, the difunctional organic compound capable of reacting with the amino function may be added first and the diamine added second, to obtain the desired organopolysiloxane. Alternately, these reagents may be added in reverse order.
[0114] The reaction is run at a temperature appropriate for the reagents. For example, when the difunctional organic compound capable of reacting with the amino functions is a dichloride, the reaction may be run at relatively higher temperatures (typically above 60° C. and often above 80° C.). Alternately, when the difunctional organic compound capable of reacting with the amino functions is a dibromide, the reaction may be run at relatively lower temperatures, including at room temperature (e.g., 21° C.). Alternately, when the difunctional organic compound capable of reacting with the amino functions is an activated dichloride, the reaction may be run at relatively lower temperatures, including at room temperature (e.g., 21° C.). One of ordinary skill in the art would understand the reaction conditions suitable for the specific difunctional organic compound capable of reacting with the amino functions.
[0115] The above making process is also generally described by Lange (U.S. Pat. No. 7,563,856). One skilled in the art would understand how the general process disclosed in Lange can be reapplied to the present development in order to produce the organopolysiloxanes of the present invention.
[0116] In one embodiment, the reaction is run without the addition of solvent, resulting in a substantially solvent-free process for making the organopolysiloxane of the present invention.
[0117] In another embodiment, the reaction is run and subsequently excess amine is added. Without being bound by theory, it is believed that the excess amine will consume the reactive groups of any residual difunctional organic compounds capable of reacting with the amino functions.
[0118] In another embodiment, the reaction mixture is further reacted with an amine containing molecule. Non-limiting examples of such amines include ammonia, methylamine, dimethylamine, trimethylamine, triethylamine or ethanolamine or diethanolamine. Without being bound by theory it is believed that this further reaction caps un-reacted akyl-halide functionality.
[0119] In another embodiment, the reaction mixture is further reacted with a mono-functional organic species capable of reacting with the amine functionality of the organopolysiloxane. Non-limiting examples of such mono-functional organic species include: methyl bromide, methyl iodide, and ethylbromide. Without being bound by theory it is believed that this further reaction helps to quaternize any residual neutral amine groups of the organopolysiloxane, including the terminal amine functionality.
[0120] Without being bound by theory it is expected that primary and secondary amines can react multiple times to form secondary, tertiary and quaternized amines. This can lead to branching at the amine groups. It is also thought that the reaction conditions can be modified to increase the degree of branching. Reaction conditions involving an initial excess quantity of the groups capable of reacting with an amine over the concentration of the primary or secondary amines can lead to higher levels of branching. Subsequent addition of tertiary diamines can then lead to chain growth of the branched amines.
IV. Uses of the Organopolysiloxane Compositions
[0121] The organopolysiloxanes according to the present invention can be formulated into a variety of consumer product compositions that can be applied to substrates in order to impart consumer-desired benefits, such as conditioning. Such substrates can include fabric, non-woven materials, paper products, hard surface materials, and biological materials (e.g., keratinous materials such as hair or skin).
[0122] The consumer product compositions comprising the organopolysiloxane polymers of the present invention may be prepared by any suitable process, such as processes known by those skilled in the art. For example, the organopolysiloxane polymers can be incorporated directly into the composition's other ingredients without pre-emulsification and/or pre-mixing to form the finished products. Alternatively, the organopolysiloxane may be mixed with surfactants, solvents, suitable adjuncts, and/or any other suitable ingredients to prepare emulsions prior to compounding the finished products.
[0123] The consumer product composition can comprise one or more surfactants. The surfactants may comprise cationic, anionic, non-ionic, zwitterionic, and/or amphoteric surfactants. In one embodiment, at least one surfactant is anionic. Various forms of the consumer product composition can be aqueous or non-aqueous; in one embodiment, an aqueous composition has a pH greater than 3, or greater than 5.
[0124] The composition may also comprise at least one benefit agent. Benefit agents can be hydrophobic or hydrophilic. Useful hydrophobic benefit agents include silicones, vinyl polymers, polyethers, materials comprising a hydrocarbon wax, hydrocarbon liquids, fluid sugar polyesters, fluid sugar polyethers, and mixtures thereof. In one embodiment, the silicones that are useful as benefit agents are organosilicones. In another embodiment, the silicone benefit agent is selected from the group consisting of a polydimethylsiloxane, an aminosilicone, a cationic silicone, a silicone polyether, a cyclic silicone, a silicone resin, a fluorinated silicone, and mixtures thereof. In one embodiment, the benefit agent is a liquid at room temperature. In another embodiment, the benefit agent is a solid or semi-solid at room temperature. In one embodiment, the benefit agent is a perfume or a silicone. Further, the benefit agent may be encapsulated. In one embodiment, the benefit agent is an encapsulated perfume.
[0125] The organopolysiloxane may be pre-emulsified prior to compounding into a consumer product composition. In one embodiment, a benefit agent is included with the organopolysiloxane in the pre-emulsion. In one embodiment, the benefit agent and the organopolysiloxane mixture can form a particle in the pre-emulsion.
[0126] Materials which may be helpful in creating such emulsions include: Tergitol 15-S-5, Terigtol 15-S-12, and TMN-10. The suspensions can be made by mixing the components together using a variety of mixing devices. Examples of suitable overhead mixers include: IKA Labortechnik, and Janke & Kunkel IKA WERK, equipped with impeller blade Divtech Equipment R1342. In some cases, high shear processing is required to obtain a narrow particle size distribution. Example of a suitable high shear processing device is M-110P Microfluidizer from Microfluidics.
Examples
[0127] The following examples 1-10 further describe and demonstrate exemplary embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention since many variations thereof are possible without departing from the spirit and scope of the invention. Ingredients are identified by chemical name, or otherwise defined below.
[0128] To a clean vessel is added the quantity of silicones (available from Gelest Co., Morrisville, Pa.) shown in Table 1 and an amount of isopropanol (available from Sigma-Aldrich, Milwaukee, Wis.) equal to the amount of silicone. This is mixed by stirring the sample at 30 rpm for one hour and then the quantity of dihalide (available from Sigma-Aldrich, Milwaukee, Wis.) is added and mixed by stiffing at 30 rpm for 2 hours at 50° C. After two hours, the quantity of diamine (available from Sigma-Aldrich, Milwaukee, Wis.) shown in the table is added. This is followed by heating the sample at 50° C. for 16 hours.
[0000]
TABLE 1
Amino Silicone
Weight (g)
Molecular Weight
Weight (g)
Weight (g)
Example #
starting material 1
Silicone
(Daltons) Silicone
x
Dihalide
Dihalide
Diamine
1
DMS-A15
50 g
3000
40
16.27 g
Dibromo
11.47 g
Hexane
2
DMS-A15
25 g
3000
40
40.67 g
Dibromo
28.67 g
Hexane
3
DMS-A32
250 g
30000
400
8.13
Dibromo
5.74 g
Hexane
4
DMS-A32
100 g
30000
400
32.53 g
Dibromo
22.93 g
Hexane
5
DMS-A32
500 g
30000
400
21.87 g
Dibromo
11.47 g
Dodecane
6
DMS-A32
250 g
30000
400
7.20 g
Dibromo
5.73 g
Butane
7
DMS-A15
50 g
3000
40
41.67 g
1,4-dichloro-
28.67 g
2-butene
8
DMS-A32
50 g
30000
400
1.67 g
1,4-dichloro-
2.29 g
2-butene
9
DMS-A32
50 g
30000
400
4.17 g
1,4-dichloro-
5.73 g
2-butene
10
DMS-A32
100 g
30000
400
2.93 g
p-
1.55 g
dichloroxylene
1 = catalogue numbers of aminosilicone starting material, available from Gelest Company, Morrisville, PA)
End-Use Formulations:
[0129] Exemplary organopolysiloxanes of the present invention are formulated into different product chassis to make various consumer product formulations. In some embodiments, the organopolysiloxane is added to the ingredient mixture in the form of an emulsion.
Emulsion Preparation:
[0130] The following emulsions are prepared for use in the consumer product formulation examples set forth herein.
[0131] The organopolysiloxanes from Examples 1-10 above are used to make the emulsions used in making the consumer product formulation examples below.
[0132] The organopolysiloxanes from Examples 1-10 are first emulsified using a homogenizer at 3,500 rpm, and then microfluidized at 20,000 psi to obtain sub-micron size emulsions (mean particle size 250 nm, as measured using Horriba instrumentation as known in the art).
[0000]
TABLE 2
Material
%
Organopolysiloxane of Examples 1-10
20.00
Tergitol 15-S-5 1
3.00
Acetic Acid
0.60
Dilution Water
q.s. to 100%
1. 1 Available from Sigma Aldrich
Hair Care Compositions Comprising the Organopolysiloxanes:
[0133] Examples below list non-limiting examples of hair care shampoo and conditioner compositions comprising emulsions of the organopolysiloxane conditioning polymers of the present invention.
Shampoos are Prepared as Follows:
[0134]
[0000] Material % active in shampoo Deionized Water q.s. to 100% SLE1S 1 10.50% CMEA 2 0.85% Na 4 EDTA 0.14% NaBenzoate 0.25% Citric acid 0.22% SLS 3 1.50% CAPB 4 1.00% Kathon 0.03% Emulsion according to Table 2 5.00% C500 Guar 5 0.25% 1 Sodium Laureth Sulfate, 28% active, supplier: P&G 2 Cocoamide MEA available as Monamid CMA, 85% active, available from Goldschmidt Chemical 3 Sodium Lauryl Sulfate, 29% active from P&G 4 Cocoamidopropyl Betaine available as Tego ® betaine F-B, 30% active, available from Goldschmidt Chemicals 5 Jaguar ® C500, MW—500,000, CD = 0.7, available from Rhodia
Ingredients are combined and mixed by conventional means as known by one of ordinary skill in the art.
Hair Conditioners are Prepared as Follows:
[0135]
[0000]
Material
% active in conditioner
Cetyl Alcohol
1.21%
Stearyl Alcohol
3.00%
Behentrimonium methosulfate/IPA 1
2.47%
Benzyl Alcohol
0.43%
Deionized Water
q.s. to 100%
Perfume
0.59%
EDTA
0.15%
Emulsions according to Table 2
5.00%
1 Behentrimonium methosulfate/Isopropyl alcohol, available as Genamin BTMS from Clariant
[0136] Ingredients are combined and mixed by conventional means as known by one of ordinary skill in the art.
Top Sheets and Paper:
[0137] It can be appreciated by one of ordinary skill in the art that any of a number of means of applying the organopolysiloxane to the nonwoven can be utilized. The organopolysiloxane may be emulsified prior to application to the nonwoven, including emulsification into water or other primarily aqueous carrier. The organopolysiloxane may be dissolved in a suitable carrier prior to application to the nonwoven. The carrier may be volatile to facilitate removal of the carrier after treatment of the nonwoven. In one non-limiting example of the present invention, any of the organopolysiloxanes of Examples 1-10 is emulsified as described in Table 2 and air sprayed onto a 24 gsm (grams per square meter) non-woven top sheet to obtain a final coating of 5 gsm. Top sheets are air dried overnight and allowed to equilibrate in a controlled humidity room.
Fabric Care Compositions:
[0138] Examples below list non-limiting examples of Fabric Care composition comprising mulsions of the organopolysiloxane conditioning polymers of the present invention.
Heavy Duty Liquid (HDL) Laundry Detergent Formula are Prepared as Follows:
[0139]
[0000]
Material
% in HDL
HDL AE1.8S Paste 1
26.83
DTPA 50% ACTIVE 2
0.63
HDL Brightener 15 Premix 3
3.03
Monoethanolamine (MEA)
2.26
C 12 /C 14 AMINE OXIDE 4
1.69
Alkoxylated polyamine HOD Base 5
1.20
CAUSTIC SODA (NaOH)
0.53
Anionic Detergent Blend MVP-2 Paste 6
4.25
Borax Premix for HDL 7
6.06
C11.8 HLAS 8
4.19
CITRIC ACID SOLUTION 9
5.34
C12-18 FATTY ACID 10
1.42
CALCIUM FORMATE
0.84
Water
q.s. to 100%
Subtilisins (NFNA-HA Base ) 11 —(54.5 mg/g)
1.27
MANNANASE (25.6 mg/g)
0.06
NATALASE (29.26 mg/g)
0.31
Polyethyleneimine Ethoxylate PE-20 (ODD-Base) 12
1.89
Emulsions according to Table 2
20.00
1 Available from Shell Chemicals, Houston, TX
2 Diethylenetriaminepentaacetic acid, sodium salt
3 Available from The Procter & Gamble Company, Cincinnati, OH
4 Available from The Procter & Gamble Company, Cincinnati, OH
5 Available from BASF, AG, Ludwigshafen
6 Available from The Procter & Gamble Company, Cincinnati, OH
7 Available from Univar, Cincinnati, OH
8 Available from Huntsman Chemicals, Salt Lake City, UT
9 Available from Ciba Specialty Chemicals, High Point, NC
10 Available from Enencor International, South San Francisco, CA.
11 Available from Genencor, Rochester, NY
12 Available from BASF, AG, Ludwigshafen
[0140] Ingredients are combined and mixed by conventional means as known by one of ordinary skill in the art.
Fabric Softener Compositions are Prepared as Follows:
[0141]
[0000]
EXAMPLE COMPOSITION
78
Fabric Softener Active 1
11.0
Fabric Softener Active 2
—
Cationic Starch 3
—
Polyethylene imine 4
—
Quatemized polyacrylamide 5
0.2
Calcium chloride
0.15
Ammonium chloride
0.1
Suds Suppressor 6
—
Emulsions according to Table 2
15.0
Perfume
2.0
Perfume microcapsule 7
0.75
Water, suds suppressor, stabilizers, pH control agents,
q.s. to 100%
buffers, dyes & other optional ingredients
pH = 3.0
1 N,N di(tallowoyloxyethyl)-N,N dimethylammonium chloride available from Evonik Corporation, Hopewell, VA.
2 Reaction product of fatty acid with Methyldiethanolamine, quaternized with Methylchloride, resulting in a 2.5:1 molar mixture of N,N-di(tallowoyloxyethyl) N,N-dimethylammonium chloride and N-(tallowoyloxyethyl) N-hydroxyethyl N,N-dimethylammonium chloride available from Evonik Corporation, Hopewell, VA.
3 Cationic starch based on common maize starch or potato starch, containing 25% to 95% amylose and a degree of substitution of from 0.02 to 0.09, and having a viscosity measured as Water Fluidity having a value from 50 to 84. Available from National Starch, Bridgewater, NJ
4 Available from Nippon Shokubai Company, Tokyo, Japan under the trade name Epomin 1050.
5 Cationic polyacrylamide polymer such as a copolymer of acrylamide/[2-(acryloylamino)ethyl]tri-methylammonium chloride (quaternized dimethyl aminoethyl acrylate) available from BASF, AG, Ludwigshafen under the trade name Sedipur 544.
6 SILFOAM ® SE90 available from Wacker AG of Munich, Germany
7 Available from Appleton Paper of Appleton, WI
[0142] Ingredients are combined and mixed by conventional means as known by one of ordinary skill in the art.
[0143] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”
[0144] Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
[0145] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
|
Disclosed herein are inventive branched blocky cationic organopolysiloxanes and consumer product compositions comprising such organopolysiloxanes. Such compositions can deposit effectively onto target substrates to deliver consumer-desired benefits such as conditioning, anti-wrinkle, softness, and anti-static.
| 3
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FIELD OF THE INVENTION
The present invention pertains to pH control systems and more particularly to a control system adapted to the maintenance of solvent pH in an electrolytic conductivity detector apparatus.
BACKGROUND OF THE INVENTION
The electrolytic conductivity detector was originally reported by Piringer and Pascalau in the Journal of Chromatography, volume 8, p. 410, 1962. By combusting a sample in a furnace containing a CuO catalyst, that sample was converted to carbon dioxide. The carbon dioxide was subsequently dissolved in deionized water and the conductivity of the water was constantly monitored. Similarly, Coulson extended this theory of operation to include the selective detection of halogen, sulfur, and nitrogen containing compounds as described in the Journal of Gas Chromatography, volume 73, p. 19, 1972. Further improvements have been claimed in: Journal of Chromatography, volume 73, p. 19, 1972; Journal of Chromatographic Science, volume 12, p. 152, 1972; Analytical Chemistry, volume 46, p. 755, 1974; Analytic Chemistry, volume 46, p. 755, 1974; Analytic Chemistry, volume 47, p. 367, 1975; U.S. Pat. No. 3,934,193, 1976; U.S. Pat. No. 4,032,296, 1977; NTIS pp. 250 451/256, 1976; U.S. Pat. No. 4,555,383, 1985, U.S. Pat. No. 4,649,124, 1987. Electrolytic conductivity detectors in general are reviewed by Selucky in Chromatographia, volume 5, p. 359, 1972, and specifically for nitrogen detection by Hall in CRC Critical Reviews in Analytical Chemistry, p. 323, 1978.
The importance of proper solvent pH of electrolytic conductivity detectors has been documented by Patchett in Journal of Chromatographic Science, volume 8, p. 155, 1969; Coulson in the Journal of Gas Chromatography, p. 258, 1966; and Pape, et al. in The Journal of Chromatography, volume 134, p. 1, 1977. If, in the nitrogen mode, the pH of the electrolyte is below 7, a decrease in response, "w" shaped peaks, and negative peaks have been observed. For this reason, Selucy in Chromatographia, volume 5, p. 323, 1978, and Jones, et al. in the Journal of Chromatography, volume 73, p. 19, 1972, have claimed that the pH of the solvent should be maintained between 7.0 and 8.0.
Maintenance of solvent pH for the nitrogen mode is usually accomplished through mixed bed resins. Most often, a strong mixed resin bed is preceded by a small amount of a strong base resin of the amine or hydroxyl type. Pape, Rodgers, and Flynn, however, in The Journal of Chromatography, volume 134, p. 1, 1977, have suggested the introduction of nitrogen into the reaction gas stream by means of a mixing manifold as a means of controlling pH.
Mixed bed resins, while controlling the pH to some extent, optimizing peak shape and sensitivity, suffer in actual operation. The final pH of the solvent with these types of systems is highly dependent on flow rate through the bed. This property is used to advantage by Pape, Rodgers, and Flynn in The Journal of Chromatography, volume 134, pp. 1-24, 1977, who use this dependency as the controlling factor in pH adjustment. Having a set flow rate through the resin bed, however, reduces the flexibility in application to differing cell designs and operational techniques. Furthermore, the flow rate needed to maintain a specific pH is not constant over an extended period of time. Cox and Tanaka, in Analytical Chemistry, volume 57, p. 385, 1985, have shown that the ion exchange rate of a resin bed depends on both the ionic content of the incoming solvent and the degree of ionic depletion of the resin bed.
In addition, the two component resin system is harder to prepare than a single component resin system.
SUMMARY OF THE INVENTION
The invention is an improved solvent pH control system for electrolytic conductivity detection in gas chromatography. A simplified, single component resin bed is coupled with a permeation system.
The basic components are the ion exchange resin cartridge filled with a single component resin, the permeation tube, and the permeation bottle. The permeation bottle is filled with an ionic species, which, when added to the solvent through permeation, to the interior of the tubing (such as TEFLON brand), will result in the desired control of solvent pH and remove the necessity for multi-component resin configurations in the ion exchange resin cartridge. One example is the use of an ammonia mixture in the permeation bottle which shifts the pH upward, allowing proper operation with conventional single component resin mixtures in the ion exchange resin cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation in partial cross-section of a conventional ion exchange system used in electrolytic conductivity detectors;
FIG. 2 is a side elevation in partial cross-section of the improved ion exchange system and gas permeation apparatus of the present invention;
FIG. 3 is a chart illustrating how the permeation tube and bottle are utilized with the improved deionizing chamber in an electrolytic conductivity detector system;
FIGS. 4a-d illustrate in graphic form, the performance of the system, using an atrazine sample, and varying the concentration of the permeation liquid; and
FIGS. 5a-d illustrate in graphic form, the performance of the system using a more dilute atrazine sample, again varying the concentration of the permeation liquid.
DESCRIPTION OF THE INVENTION
FIG. 1 depicts a conventional ion exchange system 10. A chamber 11 has a column of resin 12 within. In the nitrogen mode a strong base resin 13 and strong mixed resin 14 are contained in the column by glass wool 15, 16. A filter disc 17 is used with the glass wool. Solvent enters the column at an inlet 18 exits at an outlet 19.
The permeation tube and bottle 20 of the present invention are utilized in an electrolytic conductivity detector as shown in FIG. 2. The permeation tube receives the output of a simplified and improved ion exchange system 30. Rather than a multi-component resin system, the present invention employs a simplified ion exchange column, in this instance a single component resin 31. Single component resin beds are inherently more stable in pH of fluid output irrespective of resin life or fluid flow rate. The output of solvent from the ion exchange system flows through a tube 21 made from TEFLON brand material. A length of this tube 22 is contained within the permeation bottle 23. The permeation bottle is filled with a chemical species which sets up an equilibrium between its ionic and gaseous forms. In the case of the nitrogen mode, an ammonium hydroxide solution is used, with the two species in equilibrium being NH 4 + and NH 3 . Because NH 3 is a dissolved gas, it permeates the tubing and acts on the solvent to effect a favorable regulation of the solvent pH.
From the output 24 of the permeation bottle, the pH-adjusted solvent enters the gas-liquid contactor 40, where the solvent is reacted with the output of the furnace 50 in the form of combustion products. A schematic of this combination is shown in FIG. 3.
Performance of the solvent pH control system was evaluated with the use of an O.I Corporation Model 4420 Electrolytic Conductivity Detector and a Hewlett Packard Model 5890 Gas Chromatograph. By injecting nitrogen-containing compounds directly onto a capillary column, peak shape and response as a function of solvent pH via permeation could be evaluated. A hexane solution containing 1000 parts per billion of atrazine was used for the peak shape evaluation. Atrazine, having the chemical formula C 8 H 14 ClN 5 , is considered typical of compounds containing organic nitrogen.
Response of the electrolytic conductivity detector to variations in permeation liquid concentration is shown in FIGS. 4a, 4b, 4c and 4d. In FIG. 4a, there was only water (with 2% hexyl alcohol added for surfactant) in the permeation bottle. Notice the characteristic "W" shaped peak indicating improper pH balance of the conductivity solvent. In FIG. 4b, a solution of ammonium hydroxide, prepared by mixing 0.5 ml of stock ammonia solution (assayed at 30% NH 3 ) to 100 ml of the water/hexyl alcohol solution, was used as the permeation liquid. There is a slight improvement in peak shape, baseline noise, and sensitivity. Further improvement was obtained with 1 ml/100 ml ammonia solution in FIG. 4c and with 1.5 ml/100 ml ammonia solution in FIG. 4d.
Dropping the analyte concentration injected to 0.1 parts per million atrazine, FIGS. 5a, 5b, 5c, and 5d show that further increases in ammonia concentration in the permeation fluid results in no further change in response. FIGS. 5a, 5b, 5c, and 5d illustrate the response of 0.1 parts per million atrazine to 2, 3, 4, and 5 ml/100 ml of this ammonia solution. The results illustrated in FIGS. 5a-d indicate that 2 ml/100 ml represents an optimum ammonia concentration in the nitrogen mode.
Just as the permeation system is benefical in the nitrogen mode, the principles of permeation pH control have applications to other solvent systems. For example, in the halogen mode, dilute weak acid replaces the dilute base as the permeation liquid.
While the principles of the present invention have been described in connection with specific process steps and apparatus, it is to be understood that this description is made only by way of example and not as a limitation to the scope of the invention as set forth in the accompanying claims.
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A simplified, single component resin bed is coupled with a permeation tube and bottle. The permeation bottle contains an ionic species and a dissolved gas. The apparatus makes unnecessary a multi-component resin ion exchange column for solvent pH control in electrolytic conductivity detection as applied to gas chromatography.
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FIELD OF THE INVENTION
This invention relates to a portable, contained, ready-to-use assembly which provides an instant campfire, fireplace burner, cooker or the like which does not require additional fuel nor mixing, pouring, priming, nor set up procedures and which can be lighted to provide relatively long lasting, contained, outdoor fire for heat and light with a minimum of hazards.
BACKGROUND OF THE INVENTION
Each year in the United States and other countries numerous forest fires are inadvertently set off by those who carelessly and improperly make, maintain, and extinguish campfires. Thus, a primary object of the present invention is to provide a campfire which is contained, does not emit dangerous sparks, provides desirable heat, and is readily extinguished.
In the prior art there are numerous portable devices and fuel compositions which are designed to provide a convenient fire without the problem of gathering wood or other fuel and continuously feeding it to the fire. One such fuel is the common firelog which typically is sawdust held together with a wax binder which is extruded and then wrapped in a paper starter. However, the typical firelog is heavy, inconvenient to transport, sometimes difficult to light, and requires a supporting grate or fire stand. It is, therefore, one object of the present invention to provide a relatively lightweight fire assembly which is easy to start and does not require any additional grates or stands or supporting structure.
Another common apparatus in the prior art for providing a portable, relatively quick means of providing a fire is a gas stove or burner. However, these require the transportation of a heavy "bottle" or tank of gas and burner or stove parts, and at least some time and effort in assembling and setting up the burners, tanks, and stove. In addition, besides being bulky, heavy, and time consuming these gas devices are relatively expensive and require regular maintenance to keep them operating satisfactorily. Accordingly, it is another object of the present invention to provide a campfire and cooker which is lightweight, requires no set-up, and is relatively inexpensive.
Another type of portable heat or fire device is the "canned heat" which is an alcohol gel in a can. These often are used as the heat source for chafing dishes or the like where heat with low ash and few obnoxious combustion products is desired within an enclosed area. However, while clean and portable, the alcohol gels do not produce the same heat output, intensity, and ability to remain lighted that is desirable for campfires or cookers. Thus, it is yet another object of the present invention to provide an assembly which produces a flame which has a relatively high heat output and satisfactorily maintains a flame under varied conditions. These and others objects are provided by the invention described below.
The process of making the aforementioned products and devices often requires numerous steps in the production process and expensive extrusion equipment. Therefore, still yet another object of the present invention is to provide a simple and economical method of producing the assembly of the present invention.
SUMMARY OF THE INVENTION
It has been surprisingly discovered that a novel combination of a fire resistant portable container filled with a unique combustible composition will accomplish the objects set forth above.
In one aspect, the invention is a portable, fueled, assembly for providing an instant and ready-to-use campfire, fireplace burner, or cooker which comprises a portable, heat and flame resistant container which has an upwardly facing open mouth that is configured so that it can be placed in a stable position on the ground or a base support surface or structure. The container is filled with a combustible composition which will support a flame for an extended period of time. In one embodiment, the composition is disposed in the container so that a sheet-like wick can be embedded in and extend above the upper surface of the composition. The composition preferably comprises about 5% to 15% by weight of mineral spirits, about 50% to 85% of paraffin wax, and up to 40% and preferably about 15% to 35% combustible cellulose filler so that when the wick is lighted by a match or other means a useful fire is produced across the surface of the composition which will give light and substantial warmth. Preferably the container is made of a fire and heat resistant metal and is provided with a handle or other carrying means. The wick preferably is a formed from a paper material such as kraft paper or it may be a woven material of cotton fiber or the like.
In another aspect, the container is of metal and is in an inverted truncated cone shape wherein the base is the smaller circular surface or side and the open mouth is the larger circular side. The container may be provided with a lower rim which extends below the closed bottom and provides support for the container. This lower portion may be provided with orifices for airflow. Such a configuration provides a stable support for the container on a wide variety of surfaces.
In yet another aspect, the present invention is a combustible fuel composition for portable campfire assemblies, fireplace burners, cookers, and the like which comprises a major portion of a paraffin wax which is present in about 50% to 80% by weight and minor portions comprise mineral spirits and cellulose filler. The mineral spirits are a combustible hydrocarbon napthenic solvent and comprise from about 5% to 15% by weight of the composition and the cellulose filler is preferably hardwood chips comprising from about 15% to 35% by weight. The hardwood chips may be hickory, oak, maple, cherry, pecan, walnut, or like chips which burn with a desirable heat intensity and emit a pleasant aroma. Soft wood chips may be also blended in with the cellulose fiber mix. Sawdust could be used but chips are preferable.
In yet another aspect, the present invention is a method of making a portable, fueled, assembly for an instant, contained campfire which comprises the steps of providing a container with an open upwardly facing mouth and placing wood chips in mulch form in the container and filling the container with a mix of melted paraffin wax and mineral spirits. The hardwood chips being lighter or less dense will float up into the melt before it solidifies, thus, eliminating the need for any mixing or stirring. The sheet-like wick material is inserted into the upper surface of the mix and becomes impregnated with the wax mixture before it solidifies. At least an edge of the mix is exposed so that it can be lighted.
In still another aspect, the present invention is a new and of a combination of ingredients to produce a novel, portable, ready-to-use campfire.
DESCRIPTION OF THE DRAWINGS
The invention set forth above and which will be described in greater detail hereinafter can be better appreciated by reference to the drawings in which:
FIG. 1 is a perspective view of a preferred container which contains a wick and the combustible composition of invention and which has been ignited;
FIG. 2 is a vertical cross-sectional view of the container of FIG. 1 showing the arrangement of the wick, composition, and container; and
FIG. 3 is a cross-sectional view similar to FIG. 2 except that the container is a right circular cylinder and the wick is placed in an alternate position and the bottom of the container is provided with an extended rim.
DETAILED DESCRIPTION
Turning now to FIG. 1, the portable assembly 1 of the present invention is shown in perspective and it comprises container 2 with carrying means or handle 7. The assembly which is the portable or ready-to-use, contained campfire is shown in FIG. 1 after it has been ignited so that flames 3 rise as composition 4 burns. A steady flame height from 8" to 12" or more can be achieved. In this embodiment of the invention, the container 2 is a truncated cone with the open mouth 8 being circular and having a diameter of about 7" in the preferred embodiment shown. This diameter may practically vary from as low as 4" or 5" to as wide as 12" to 15" or more. The limits on size are a matter of choice for the size of the fire and desired burning time. The support surface or support means 9 also being circular has a diameter in this preferred embodiment of about 4 1/2" although this can vary from 3" or lower to 12" or greater. The distance between the opening 8 and support surface 9 which represents the height of the container in this embodiment is about 4 3/4" but can be between 3" or lower to 8" to 12" or greater.
Looking now at FIG. 2, the vertical cross-section of the assembly is shown. The wick 5 is adjacent to the interior wall surface 6 and extends above and over the upper surface of the composition 4 and is partially embedded in the surface with at least an edge in a position where it may be readily lighted with a match. This wick 5 may be kraft paper or a woven fabric. The composition fills the container to within about 1" of the rim of the mouth 8 in the embodiment being described. This volume of the composition 4 will provide a useful fire for up to five hours. The sheet-like wick forms the function of lighting the composition across the entire upper surface of the composition.
In FIG. 3, an alternate positioning of the wick 15 is shown as alternate recessed bottom or alternate support means 19 carried by the support rim 12. This alternate embodiment shows the container 10 in the shape of a right circular cylinder. Other shapes can be made within the scope of the invention, namely, bowl shapes with legs, cylinders or truncated cone or bucket shapes, or rectangler parallelpiped forms. All then configurations are within the scope of the invention.
The process for making the assembly according to the present invention comprises the steps of providing a container which is flame and heat resistant. Typically metal is the most readily available and steel is generally the lowest cost suitable metallic material. Steel, the type that is commonly used in paint buckets, fruit juice and coffee cans and the like, is preferred because of its availability and low cost. This steel is usually low carbon type and its cost is such that the container can be readily disposed of after the composition has completely burned up. Disposal presents no environmental hazard and these containers may be placed in the trash disposal receptacles found in parks and other outdoor areas.
The next step in the process of making the ready-to-use campfire assembly of the present invention requires the preparation of the combustible composition. The composition comprises a major portion of the paraffin wax which is preferably a petroleum derived hydrocarbon wax which may be described as a white crude scale wax preferably having a melt temperature range from about 117° F. to about 130° F. A particularly suitable wax is 6433 wax from the National Wax Division of the Dussek Campbell Company.
The mineral spirits or naptha which is an aliphatic hydrocarbon fraction of petroleum evolved in the distillation range of about 150° C. to about 200° C. A particularly suitable form is the paraffinic napthlanic solvent sold by Lamplight Farms of Menomonee Falls, Wis. under the brand name "Lamplight Farms Lamp Oil" which has a specific gravity at 60° F. of about 0.806.
The third ingredient of the composition, which is preferred but may be optional, is wood chips which are preferably hardwood chips of oak, hickory, maple, cherry, walnut, or the like. Sawdust or mulch from any one of these woods can be used and also pine chips or pine sawdust or other soft wood could be used. The chips can be relatively fine ground or 1/16" to 2" to 3" in length, 1/16" to 1/2" in width, and 1/16" to 1 1/2" to 3" in height. While it is a desirable feature of the invention and within its scope, the composition of the invention will perform its function satisfactorily without wood chips and will burn with the mineral spirits/wax composition.
The step in the process which requires the positioning of the wick within the container can be accomplished in either before or after the melt is poured into the container. The wick is preferably sheet-like and in one embodiment is annular in shape so that it can line the walls of the container. As mentioned above, paper, such as kraft paper, may be used or a woven fabric of cotton or other natural fiber may be used for the wick. Once the annular wick is positioned in the container the composition is then poured in to fill the container to within about 1" of the upper rim of the container. Sufficient wick material is left so that it can be folded over the upper surface of the composition so that the edge of the wick can be readily lighted by a match. The wick can be located in other positions spaced apart from the wall surface 8 as shown in FIG. 3. The important function of the wick is that it lights the entire upper surface of the composition. A cord or string-like wick of the typical candle may have a tendency to burn only in a localized area around the string-like wick and not spread across the composition surface. Thus, while not as satisfactory, to light the composition without the use of a wick, crumpled paper may be pressed against the entire surface and lighted with a match to ignite the composition.
Continuing with the process, the paraffin wax is melted and the mineral spirits is blended there within a preferred ratio of about 1 ounce of mineral spirits to about 1 pound of wax or about 7% by volume. Since the densities or specific gravities are below 1.0 and not to different, volume and weight percentages tend to be relatively close with these materials. The wood chips can be preferably placed into the container prior to pouring the melt into the container or the chips can be mixed or stirred into the melt after pouring and before it solidifies. As mentioned above, it is desirable to have a sheet-like wick inserted which can be lighted from one edge above the surface of the composition so that the flame will spread evenly and burn evenly across the surface of the composition.
In the preferred method the chips in particulate or mulch form are first placed in the container and then the melted paraffin/mineral spirits blend is poured into the container. The wood chips are less dense than the blend and rise and float within the blend resulting in a substantially uniform distribution when the melt solidifies.
In an alternate process an annular wick can be provided which is in the form of an hollow cylinder which can be inserted into the container and lines the wall of the container prior to pouring in the paraffin wax or the annular wick can be inserted into the melt before it solidifies and be spaced apart from the walls.
In another alternate embodiment which is prepared by pouring the melt according to the foregoing description and inserting therein the an annular paper wick into the melt to a depth to 1" to 3" or 4" and then folding the portion which extends above the surface downwardly to impregnate at least a portion of the wick material with the melt. Thus, a substantial portion of the upper surface of the composition is covered by the sheet-like wick material. Lighting an edge of the wick then provides for a quick start-up of the fire where the flame covers the entire upper surface of the composition.
Best Mode
The best mode of the invention for which preferred embodiments have been presented above comprises a container of the shape shown in FIG. 2 having a mouth 8 diameter of 8", a height of about 7" of steel construction. The composition comprises 7% of the aforementioned "lamp oil", 65% of the aforementioned "scale wax", and 28% hardwood chips in mulch form, all percentages being by volume. The container is filled to the brim and has a kraft paper wick 5 as shown in FIG. 2 with the wick having been pressed into the surface before the composition has solidified so it has absorbed some of the composition. The container is filled about 1/4" below the brim and the assembly weighs approximately 5 1/2 pounds and will burn up to eight hours.
The campfire assembly, when lighted, provides a flame which will resist being blown out by moderate to even relatively strong winds. Also, the fire can be snuffed out by covering the mouth of the container with any relatively flame resistant material such as metal or wood sheet or wet canvas. The flame may be readily rekindled by crumpling a piece of paper, placing it on and pressing it against the composition surface and lighting it.
Many other embodiment configurations of the present invention will become apparent to those skilled in the art upon reading this disclosure. The scope of the invention is only limited by the claims appended here to.
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A portable, contained, fueled, ready-to-use campfire assembly having a fire resistant container with an upwardly facing mouth. The container is filled with a mixture of mineral spirits, paraffin wax and hardwood chips. No additional fuel, mixing, pouring, or lighting is required and a long lasting fire is provided that resists moderate winds, is readily extinguished and does not give out dangerous sparks.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for the formation of a siliceous coating film on the surface of a substrate. More particularly, the invention relates to a method for the formation of a siliceous coating film having high resistance against formation of cracks to serve as a planarizing layer or an insulating layer on the surface of a substrate such as a substrate material for the preparation of semiconductor devices, liquid crystal display panels and the like which can withstand a relatively high temperature of heat treatments.
By virtue of the excellent properties in respect of heat resistance, abrasion resistance, corrosion resistance and others, silica-based coating films are widely formed and employed in the manufacturing processes of electronic industries, for example, as a planarizing covering layer on a semiconductor substrate provided with a circuit wiring layer of a metal or other conductive materials forming level differences on the substrate surface, and as an electric insulating layer, in semiconductor devices, between the substrate surface and a metallic circuit wiring layer thereon and between two metallic circuit wiring layers or, in liquid crystal display panels, between the base glass plate and a transparent electrode layer of ITO (indium-tin oxide) or between the ITO layer and the oppositely facing electrode layer.
Several methods are known in the art and practiced in recent years for the formation of a silica-based coating film as mentioned above including a method in which a substrate surface is coated with a coating solution containing a polysilazane compound as a film-forming constituent followed by drying and a heat treatment to convert the polysilazane film into a silica-based film and a method in which the coating solution contains a polysilazane compound modified by a reaction with an alkyl amine or alkanol amine compound (see, for example, Japanese Patent Kokai 5-121572, 6-73340, 6-128529, 7-2511 and 9-157544).
Each of the above described methods is taught to be applicable to the surface of a substrate having a circuit wiring layer of a metal such as aluminum having relatively low heat resistance not to give a high reliability limiting temperature. In fact, the heat treatment for the formation of the silica-based coating film is conducted at a relatively low temperature of about 450 to 500° C. in consideration of the low heat resistance of the aluminum layer.
The above mentioned polysilazane-containing coating solution, which is used usually in a process involving a baking treatment at 450 to 500° C., is not suitable for the formation of a coating film of silica even by increasing the baking temperature to 550 to 800° C. due to the problem that the rate of oxidative conversion of the polysilazane layer into a silica film cannot be high enough sometimes resulting in an incompletely oxidized silica-based film leaving Si—H linkages and N—H linkages originating in the starting polysilazane compound not to exhibit high etching resistance.
It is also a known method disclosed in Japanese Patent Kokai 4-63833 that a coating solution, which contains a polysilazane compound modified or inactivated beforehand by the reaction with hexamethyl disilazane and the like to destroy the active hydrogen atoms bonded to the silicon atoms or nitrogen atoms in the polysilazane compound, is used for the formation of a coating layer. This method, however, is not without a problem, in particular, when applied to a surface having stepped level differences because, although the silica coating film formed from an inactivated polysilazane compound has high hardness and exhibits good etching resistance on the raised areas of the stepped substrate surface, the coating film formed on the recessed areas of the stepped substrate surface sometimes exhibits only poor etching resistance adversely affecting the performance of the semiconductor devices.
When the substrate, on which an insulating or planarizing layer of silica is to be formed, has high heat resistance to withstand a temperature of 800 to 1000° C. as is the case when the circuit wiring layer is formed from a more heat-resistant material such as polycrystalline silicon, it is an established prior art that a coating layer of phosphosilicate glass (PSG) is first formed on the substrate surface by the chemical vapor-phase deposition (CVD) method followed by a reflow heat treatment undertaken at about 1000° C. In addition to a disadvantage due to low productivity and high costs, a problem in this method is that, as a consequence of this high temperature for the reflow heat treatment, the performance of the semiconductor devices prepared by this method is adversely affected due to excessive diffusion of the dopant through the source layer and drain layer of the device.
As a method for the formation of a silica-based insulating or planarizing layer on a substrate surface without necessitating a heat treatment at such a high temperature mentioned above, the so-called SOG (spin-on-glass) method is proposed by using a coating solution. This method, however, cannot substitute the CVD method mentioned above because the silica-based coating film formed by this SOG method using a conventional coating solution cannot be thick enough without a trouble of crack formation, namely, with a low crack-forming thickness limit.
SUMMARY OF THE INVENTION
The present invention accordingly has an object to provide, in view of the above described problems and disadvantages in the prior art methods, a novel and improved method for the formation of a siliceous coating film having a high crack-forming thickness limit by using a coating solution without necessitating a high-temperature heat treatment as is essential in the CVD method applicable to a substrate of high-temperature resistance to be freed from the trouble due to excessive diffusion of the dopant in the source layer and drain layer.
Thus, the method of the invention for the formation of a siliceous coating film on the surface of a substrate comprises the steps of:
(a) coating the surface of the substrate with a coating solution containing a reaction product of a polysilazane compound and a dialkyl alkanol amine, referred to as the modified polysilazane hereinafter, to form a coating layer;
(b) drying the coating layer to form a dried coating layer;
(c) subjecting the dried coating layer of the modified polysilazane to a first heat treatment at a temperature in the range from 350 to 450° C. for a length of time in the range from 10 to 60 minutes; and
(d) subjecting the coating layer after the first heat treatment to a second heat treatment at a temperature in the range from 550 to 800° C. for a length of time in the range from 0.5 to 60 minutes.
In particular, the first heat treatment in step (c) is conducted under monitoring of the infrared absorption spectrum of the coating layer until substantially complete disappearance of the absorption bands at wave numbers in the vicinities of 800 to 880 cm −1 , 950 cm −1 and 2200 cm −1 .
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an infrared absorption spectrum of a coating film of the modified polysilazane compound prepared in Preparation 1.
FIG. 2 is an infrared absorption spectrum of a coating film of a polysilazane compound after an inactivation treatment with hexamethyl disilazane.
FIG. 3 shows infrared absorption spectra of the coating films in Example 1, Comparative Example 2 and Comparative Example 3 after the first heat treatment by the curves I, III and II, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is understood from the above given summarizing description, the characteristic features of the inventive method consist in the use of a very specific and unique coating solution and in the specific and unique conditions of heat treatment of the coating layer which is conducted in two steps.
Namely, the film-forming ingredient in the coating solution is a modified polysilazane compound which is a reaction product of a polysilazane compound and a dialkyl alkanol amine. In the formation of a silica coating film by a coating method with a polysilazane compound, it is a known method that the polysilazane compound is treated beforehand with hexamethyl disilazane and the like to inactivate the hydrogen atoms directly bonded to the silicon atoms and nitrogen atoms. A problem in this case is that the silica coating film thus formed sometimes has low etching resistance in the recessed areas of the substrate surface having stepwise level differences. In this regard, it is an object of the present invention to provide a novel process capable of dissolving the above mentioned disadvantage in the prior art method by using an inactivated polysilazane compound. The starting polysilazane compound, which is not particularly limitative and is used without any inactivation treatment, can be prepared, for example, from dichlorosilane and ammonia as the starting materials. As is known, this polysilazane compound has active hydrogen atoms or, namely, hydrogen atoms bonded to the silicon atoms and nitrogen atoms to be susceptible to a crosslinking reaction with an increase of the viscosity or gelation.
This trouble of viscosity increase or gelation is increased as the molecular weight of the polysilazane compound is increased and a high molecular weight polysilazane is undesirable also in view of obtaining an appropriate concentration of the modified polysilazane for the formation of a coating layer of a sufficiently large thickness by a single coating work and convenience of concentration adjustment. When the molecular weight of the polysilazane compound is too low, on the other hand, a decrease is caused in the crosslinkability of the polymer molecules resulting in appearance of an orange-peel defect on the surface of the coating layer and an increase is caused in the sublimation of the modified polysilazane in the course of the drying treatment resulting in a decrease in the thickness of the coating layer or formation of cracks therein. Accordingly, the starting polysilazane compound should have a weight-average molecular weight Mw in the range from 1500 to 5000 or, preferably, from 1700 to 3000 as determined by the gel permeation chromatographic (GPC) method by making reference to known polystyrene samples. The dispersion of the molecular weight as indicated by the ratio of Mw:Mn (Mn: number-average molecular weight) is also an important characterizing parameter of a polymeric compound and the polysilazane compound should have a Mw:Mn not exceeding 4.
The modified polysilazane as the film-forming ingredient in the coating solution used in the inventive method is prepared by reacting the above described polysilazane compound with a dialkyl alkanol amine compound exemplified by N,N-dimethyl ethanolamine, N,N-diethyl ethanolamine, N,N-dibutyl ethanolamine, N,N-dimethyl propanolamine, N,N-dimethyl butanolamine, N,N-dimethyl pentanolamine, N,N-dimethyl hexanolamine and N,N-dimethyl heptanolamine, of which dimethyl alkanol amines are preferable and N,N-dimethyl hexanolamine is more preferable, although any of these dialkyl alkanol amines can be used either singly or as a combination of two kinds or more according to need. Several grades of modified polysilazane products are available on the market and can be used as such in the present invention.
The reaction of a polysilazane compound with the above described dialkyl alkanol amine compound is conducted in an organic solvent to give a solution containing the modified polysilazane compound, for example, according to the procedure disclosed in Japanese Patent Kokai 6-128529. Namely, a starting polysilazane compound and a dialkyl alkanol amine compound are jointly dissolved in an organic solution in a molar ratio in the range from 99.9:0.1 to 50:50 to give a solution which is kept standing at a temperature in the range from 0° C. to the boiling point of the solvent so that the reaction proceeds between the reactants to give a modified polysilazane compound. If necessary, the concentration of the thus prepared solution is adjusted to have a concentration and viscosity suitable for the coating works therewith.
The organic solvent used in the preparation of the modified polysilazane solution is not particularly limitative provided that the reactants can be dissolved therein. Examples of suitable organic solvents include alcohols such as methyl and ethyl alcohols, ketones such as methyl isobutyl ketone, glycol ethers such as ethyleneglycol monomethyl ether, hydrocarbon compounds such as cyclohexane, toluene, xylene, mesitylene, cyclohexene, dimethyl cyclohexane, ethyl cyclohexane, p-menthane, Decalin, i.e. decahydronaphthalene, 2,2,5-trimethylhexane, dipentene, decane, isononane and octane, and ethers such as ethyl butyl ether, dibutyl ether, dioxane and tetrahydrofuran. These organic solvents can be used either singly or as a mixture of two kinds or more.
Though not particularly limitative, the concentration of the modified polysilazane compound in the coating solution used in the inventive method is in the range from 10 to 40% by weight or, preferably, from 15 to 25% by weight. When the concentration is too high, a decrease is caused in the storage stability of the coating solution along with a disadvantage of difficulty in the control of the thickness of the silica coating film formed by using the coating solution. When the concentration is too low, on the other hand, only a very limited thickness can be obtained of the coating film formed by a single coating work necessitating several times repetition of recoating until a silica coating film having a desired thickness could be obtained.
The method of the present invention is applicable to any substrate materials provided that the substrate material can withstand the temperature of the heat treatment in the inventive method. Since the heat treatment in step (d) of the inventive method is performed at a temperature of 550 to 800° C. for 0.5 to 60 minutes or, preferably, for 0.5 to 15 minutes, namely, the substrate material must withstand a heat treatment at 550° C. for 0.5 minute at the least. A semiconductor silicon wafer as such can of course be the substrate material for the application of the inventive method but, when the silicon wafer is provided with a circuit wiring layer, the material of the wiring layer cannot be a metallic element such as aluminum because the performance of a circuit wiring layer of aluminum is adversely affected by a treatment at a temperature exceeding 500° C. so that the temperature in the heat treatment for the formation of a silica-based coating film is limited to about 450 to 500° C. at the highest in order not to adversely affect the performance of the semiconductor device. In this regard, the method of the present invention is quite satisfactorily applicable to a substrate material having a heat-resistant circuit wiring layer which is formed usually from polycrystalline silicon on a silicon wafer.
In step (a) of the inventive method, a heat-resistant substrate material mentioned above is coated with the coating solution containing the modified polysilazane compound at room temperature or in the range from 20 to 25° C. by a known coating method such as spinner method, spray coating method and dip coating method to form a coating layer of the coating solution followed by a heat treatment in step (b) at 100 to 300° C. to evaporate the solvent in the coating layer giving a dried coating layer of the modified polysilazane compound.
In the next place, the thus dried coating film of the modified polysilazane compound is subjected in step (c) to a first baking treatment at a temperature in the range from about 350 to 450° C. for 10 to 60 minutes. This first baking treatment is performed in an atmosphere of an inert gas such as nitrogen or an oxidizing gas such as water vapor, of which an atmosphere of water vapor is preferable though dependent on the types of the substrate materials.
The length of time for this first baking treatment is selected by conducting the treatment under monitoring of the infrared absorption spectrum of the coating film until substantial disappearance of the absorption bands at wave number ranges in the vicinities of 800-880 cm −1 , 950 cm −1 and 2200 cm −1 assignable to the Si—H bond, Si—N bond and Si—H bond, respectively. When this first baking treatment is omitted and the dried coating film is directly subjected to the baking treatment at 550-800° C. , the Si—H and N—H bonds in the modified polysilazane compound cannot be fully decomposed to leave a substantial amount thereof in the coating film not to give desirable properties to the silica coating film.
The coating film after the above described first baking treatment is then subjected in step (d) of the inventive method to a second baking treatment at a temperature in the range from 550 to 800° C. for 0.5 to 60 minutes or, preferably, for 0.5 to 15 minutes although the length of time for this second baking treatment should be as short as possible, for example, in the range from 0.5 to 3 minutes in order not to adversely affect the performance of the semiconductor devices. This second baking treatment has an effect to densify the silica coating film so that the crack-forming limit thickness of the coating film can be increased to reach 1.2 μm or even larger along with increased etching resistance of the coating film.
In the following, the method of the present invention is described in more detail by way of examples, as preceded by a description of the preparation procedure of the coating solution, which, however, never limit the scope of the invention in any way.
Preparation 1.
A dibutyl ether solution containing 19% by weight of a modified polysilazane compound, referred to as the first coating solution hereinafter, for the formation of a silica coating film was prepared by the reaction of N,N-dimethyl hexanolamine with a polysilazane compound having a weight-average molecular weight of 2400 and a molecular weight dispersion Mw:Mn of 2.34 as synthesized by a conventional method from dichlorosilane and ammonia as the starting materials.
FIG. 1 of the accompanying drawing is an infrared absorption spectrum of a film prepared by drying the above prepared coating solution on a hot plate showing absence of absorption bands in the vicinities of wave numbers 3000 cm −1 and 1200 cm −1 assignable to —CH and Si—CH 3 , respectively.
Preparation 2.
A dibutyl ether solution containing 19% by weight of a polysilazane compound, referred to as the second coating solution hereinafter, for the formation of a silica coating film was prepared by dissolving a polysilazane compound having a weight-average molecular weight of 2400 and a molecular weight dispersion Mw:Mn of 2.34 as synthesized by a conventional method from dichlorosilane and ammonia as the starting materials.
Preparation 3.
A dibutyl ether solution containing 19% by weight of an inactivated polysilazane compound, referred to as the third coating solution hereinafter, for the formation of a silica coating film was prepared by admixing 1.0% by weight, based on the inactivated polysilazane compound, of tri-n-pentylamine to a solution obtained by the reaction of hexamethyl disilazane with a polysilazane compound having a weight-average molecular weight of 2400 and a molecular weight dispersion Mw:Mn of 2.34 as synthesized by a conventional method from dichlorosilane and ammonia as the starting materials.
FIG. 2 of the accompanying drawing is an infrared absorption spectrum of a film prepared by drying the above prepared coating solution on a hot plate showing occurrence of absorption bands in the vicinities of wave numbers 3000 cm −1 and 1200 cm −1 assignable to —CH and Si—CH 3 , respectively.
Preparation 4.
A coating solution, referred to as the fourth coating solution hereinafter, for the formation of a silica coating film was prepared in the following manner. Thus, 80.75 g (0.53 mole) of tetramethoxy silane were dissolved under agitation in 298 g (6.48 moles) of ethyl alcohol to give a solution to which 76.5 g (4.25 moles) of water containing 200 ppm by weight of nitric acid were added dropwise under agitation followed by further continued agitation for about 5 hours and standing as such at room temperature for 5 days to give a solution containing 8% by weight, calculated as SiO 2 , of the hydrolysis-condensation product of tetramethoxy silane. This solution was finally admixed with 1000 ppm by weight of a silicone-based surface active agent (SH 30PA, a product by Toray Silicone Co.).
EXAMPLE 1
A semiconductor silicon wafer having a patterned layer of polycrystalline silicon on the surface was coated on a spinner with the first coating solution prepared in Preparation 1 followed by drying of the coating layer on a hot plate at 250° C. for 3 minutes to give a dried coating layer.
In the next place, the dried coating layer on the substrate was subjected to a first baking treatment at 400° C. for 20 minutes in an atmosphere of nitrogen gas. An infrared absorption spectrum of the thus obtained coating film (FIG. 3, curve I) indicated disappearance of absorption bands in the vicinities of 800-880 cm −1 , 950 cm −1 and 2200 cm −1 assignable to Si—H, Si—N and Si—H, respectively.
Further, the coating layer after the first baking treatment was subjected to a second baking treatment at 800° C. for 1 minute to complete a silica coating film having a thickness of 800 nm, which was absolutely free from cracks as inspected by using a scanning electron microscope.
Pieces taken by cutting the above prepared substrate provided with the silica coating film were immersed at room temperature in an aqueous solution containing 0.5% by weight of hydrogen fluoride to examine the etching resistance of the cross sections in the raised and recessed areas to find no erosion in both areas. Further, the etching rate of the silica coating films before and after the second baking treatment was examined against the same hydrofluoric acid solution as used above to find that the etching rate was 40 nm/minute and 15 nm/minute, respectively.
EXAMPLE 2
A silica coating film on the same substrate having a thickness of 800 nm was formed in substantially the same manner as in Example 1 except that the atmosphere for the baking treatment was filled with moisture-containing oxygen gas in place of nitrogen gas.
The thus formed silica coating film was absolutely free from cracks as examined with a scanning electron microscope.
Pieces taken by cutting the above prepared substrate provided with the silica coating film were immersed at room temperature in an aqueous solution containing 0.5% by weight of hydrogen fluoride to examine the etching resistance of the cross sections in the raised and recessed areas to find no erosion in both areas. Further, the etching rate of the silica coating films before and after the second baking treatment was examined against the same hydrofluoric acid solution as used above to find that the etching rate was 20 nm/minute and 10 nm/minute, respectively.
COMPARATIVE EXAMPLE 1
The same substrate material as in Example 1 was coated with the second coating solution prepared in Preparation 2 in place of the first coating solution and subjected to the drying treatment in the same manner as in Example 1. The experimental treatment could no longer be continued due to remarkable sublimation from the coating layer leading to a conclusion of unacceptability of the coating solution.
COMPARATIVE EXAMPLE 2
The procedure down to the steps of coating, drying and first baking treatment was substantially the same as in Example 1 excepting for the replacement of the first coating solution with the third coating solution prepared in Preparation 3. Curve III of FIG. 3 is an infrared absorption spectrum of the thus formed coating layer indicating presence of the absorption bands in the vicinities of 800-880 cm −1 , 950 cm −1 and 2200 cm −1 assignable to Si—H, Si—N and Si—H, respectively.
The coating layer was further subjected to the second baking treatment in the same manner as in Example 1 to complete a silica coating film having a thickness of 800 nm, which was free from any cracks as examined on a scanning electron microscope.
Pieces taken by cutting the above prepared substrate provided with the silica coating film were immersed at room temperature in an aqueous solution containing 0.5% by weight of hydrogen fluoride to examine the etching resistance of the cross sections in the raised and recessed areas to find that no erosion occurred in the raised areas but the recessed areas were hollow by erosion.
COMPARATIVE EXAMPLE 3
The procedure down to the steps of coating, drying and first baking treatments was substantially the same as in Example 2 excepting for the replacement of the first coating solution with the third coating solution prepared in Preparation 3. Curve II of FIG. 3 is an infrared absorption spectrum of the thus formed coating layer indicating presence of the absorption bands in the vicinities of 800-880 cm −1 and 950 cm −1 assignable to Si—H and Si—N, respectively.
The coating layer was further subjected to the second baking treatment in the same manner as in Example 1 to complete a silica coating film having a thickness of 800 nm, which was free from any cracks as examined on a scanning electron microscope.
Pieces taken by cutting the above prepared substrate provided with the silica coating film were immersed at room temperature in an aqueous solution containing 0.5% by weight of hydrogen fluoride to examine the etching resistance of the cross sections in the raised and recessed areas to find that no erosion occurred in the raised areas but the recessed areas were hollow by erosion.
COMPARATIVE EXAMPLE 4
The procedure down to the steps of coating, drying and first baking treatments was substantially the same as in Example 1 excepting for the replacement of the first coating solution with the fourth coating solution prepared in Preparation 4 and extension of the time of the first baking treatment to 30 minutes. The thickness of the thus obtained film was 600 nm. Since occurrence of cracks was found already in the coating film after the first baking treatment, the second baking treatment was not undertaken.
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Disclosed is a method for the formation of a silica coating film having a remarkably high crack-forming thickness limit on the surface of a substrate which may be highly heat resistant, for example, having a circuit wiring layer of polycrystalline silicon to withstand a temperature higher than 500° C. without excessive diffusion of dopant through the source layer or drain layer of the semiconductor device. The method comprises the steps of: coating the substrate surface with a coating solution containing a modified polysilazane which is a reaction product of a polysilazane and a dialkyl alkanol amine, drying the coating layer, subjecting the coating layer to a first baking treatment at 350-450° C. for 10-60 minutes and subjecting the layer to a second baking treatment at 550-800° C. for 0.5-60 minutes.
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The present invention relates to a method and apparatus for determining the percentage oil content produced by an oil well.
BACKGROUND OF THE INVENTION
In the oil industry, there are two measurements which are of concern when attempting to determine oil produced by an oil well. The first being is the gross production of the oil well and the second is the percentage of oil content in gross production.
In order to determine gross production, it is conventional to employ a "paddle wheel" mechanism in the well production flow stream. The rotational velocity of the paddle is monitored and used in calculation to obtain a gross production figure.
In order to determine the percentage oil content from the gross production, it was conventional to manually sample the well production; however, in recent years automated systems have been developed to facilitate this process. Some known systems use a test vessel in which a constant volume of liquid is admitted and monitored by a float arrangement. The test vessel is mounted on a monitoring mechanism calibrated according to the density of water. The difference in output between a predetermined volume of water and an equal volume of well production is a measure of the percentage oil content of the well output. Other automated systems use a probe to detect the changes in the oil-water ratio by means of a "dielectric constant" effect.
Heavy oil has a solids content often in excess of 15% and is of a much greater viscosity than conventional oil. The above described measurement systems suffer from significant drawbacks. For example, the paddle wheel arrangement tends to become clogged with heavy oil. The constituent elements of the heavy oil tend to stratify in the sample container giving different results depending upon the depth from which a sample is taken. Further, all known automated systems require some form of solids filtration. It is not practical to filter solids out of heavy oil production, the heavy oil will either not flow through or will rapidly destroy any known filtration mechanism. In addition, the build up of solids upon any test probe or testing vessel used will, over time, inevitably result in a distortion of the data obtained.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a method and an apparatus which mitigate the drawbacks of the prior art.
Broadly, in accordance with one aspect of the present invention, there is provided a method of measuring the oil content in the gross oil production of an oil well in which the percentage of solids content thereof is known, the method comprising the steps of:
a. introducing a predetermined weight of well production into the vessel;
b. determining the time interval required to introduce the predetermined weight of well production into the vessel;
c. determining the total well production flow rate of the well production into the vessel during the time interval;
d. electromagnetically determining the percentage water content in the well production;
e. determining from the percentage water content the water flow rate into the vessel during the time interval;
f. determining from the known percentage solids content the solids flow rate into the vessel during the time interval; and
g. determining the percentage oil content in the well production by deducting the solids flow rate and the water flow rate from the total well production flow rate.
In accordance with another aspect of the present invention, there is provided an apparatus for measuring the production of oil in the gross production of an oil well where the percentage of solids content of the gross oil production of the well is known, the apparatus comprising a pressure vessel having a well production inlet adapted to be connected to a feeder pipeline originating from one or more oil wells and a well production outlet for discharging well production from the vessel, means for subjecting a sample of the contents in the vessel to a predetermined electromagnetic signal and producing an electrical output signal representative of the percentage water content of the contents of the vessel, means for admitting a predetermined weight of well production into the vessel and producing a signal representative of fluid flow rate of the predetermined weight of well production into the vessel, and means responsive to the signal representative of fluid flow rate, the electrical output signal representative of the percentage water content and a signal representative of the known percentage solids content for producing in output representative of the percentage oil content of oil in the contents of the vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, wherein:
FIG. 1 is a schematic representation of a preferred embodiment of the present invention;
FIG. 2 is a schematic drawing illustrating an electrical control system according to a preferred embodiment of the invention;
FIG. 3 is a perspective view of a pressure vessel and associated components for holding well production sample;
FIG. 4 is a schematic illustration of the pressure vessel illustrated in FIG. 3;
FIGS. 5, 6 and 7 are side, plan and right side views, respectively, of the pressure vessel and a skid assembly for supporting the pressure vessel and associated components;
FIG. 8A is a partially broken cross-sectional view of the upper end portion of the vessel illustrating means by which well production introduced into the vessel is degassed and agitated;
FIG. 8B is a detailed view of FIG. 8A.
FIG. 9 is a transverse cross-section view of the vessel illustrating the well production discharge head disposed within and secured to the vessel;
FIG. 10 is a partially broken cross-sectional view of the lower end portion of the vessel illustrating means for discharging well production from the vessel and means for flushing and desanding the vessel; and
FIGS. 11 and 12 are front and top views, respectively, of an apparatus, mounted on a skid assembly, for determining the percentage water content of a sample of the well production taken from the vessel.
FIG. 13 is a side elevation view of an apparatus, mounted on a skid assembly, for determining the percentage of water content of a sample of the well production taken from the vessel.
DESCRIPTION OF PREFERRED EMBODIMENT
With particular reference to FIG. 1 of the drawings, there is illustrated an apparatus 10 for determining the percentage oil content in the gross production of an oil well where the percentage of solids content of the gross oil production of the well is known. The apparatus comprises a pressure vessel 12 having a well production inlet 14 adapted to be connected to a feeder pipeline (not shown) originating from one or more oil wells and a well production outlet 16 for discharging well production from the vessel. The vessel also includes a sample outlet 18 and a sample return 20 for communicating a sample of the well production in the vessel to a means 22 which subjects the sample to an electromagnetic signal and produces an electrical output signal representative of the percentage water content of the contents of the vessel. A load cell 24 supports the vessel and produces an electrical output signal representative of the weight of the vessel and its contents. Control means 26 (FIG. 4), which includes a microprocessor or computer 28 and various electrically actuated valves described later, is responsive to the output of load cell 24, the electrical output signal representative of the percentage water content of means 22 and a signal representative of the known percentage solids content for producing an output representative of the percentage oil content of oil in the contents of the vessel.
With reference to FIGS. 3 to 7, vessel 12 is comprised of a cylindrical central portion 40, and spherical upper and lower end portions 42 and 44, respectively. Lower end portion 44 is seated upon load cell 24 in coaxial relation thereto while the load cell, inturn, is secured to a base 48 of a support or skid assembly 46. A pair of vertical supports 50 and 52 are secured to and extend vertically from the opposed ends of base 48.
Lower end portion 44 of the vessel is secured to the skid against radial movement but is permitted the limited axial displacement necessary to communicate changes in weight of the vessel to the load cell. To that end, there is provided a pair of lugs 54 secured to and extending vertically from base 48 on diametrically opposed sides of the vertical axis of the load cell with each lug 54 being formed with a vertical slot 56. An associated pair of skirt lugs 58 depend from lower end portion 44 of the vessel on diametrically opposed sides of the longitudinal axis of the vessel with each lug 58 being formed with a vertical slot 60. As shown, one of lugs 54 is associated with one of lugs 58 with their slots being alignable to receive a bolt and nut assembly generally designated by reference numeral 62.
Upper end portion 42 of the vessel is similarly secured to the skid against radial movement but is permitted limited axial displacement necessary to communicate changes in weight of the vessel to the load cell. To that end, there is provided a pair of spaced, suitably reinformed arms 64 extending horizontally from vertical support 50 toward support 52. The free ends of arms 64 are each formed with a vertical slot 66. Slots 66 are arranged to be disposed on diametrically opposed sides of the coaxial axes of vessel 12 and load cell 24. Lugs 68 extend upwardly from upper end portion 42 of the vessel on diametrically opposed sides the longitudinal axis of the vessel with each lug 68 being formed with a vertical slot 70. As shown, each lug 68 is associated with one of arms 64 with their respective slots 66 and 70 being aligned to receive a bolt and nut assembly generally designated by reference numeral 72.
Vessel 12 is pressurized with a suitable make-up gas and maintained at a pressure of about 175 psi in order to accommodate inconsistencies in the output of the well and, more specifically, to provide a means of discharging through outlet 16 excess well production received through inlet 14. Thus, with reference to FIGS. 3 to 5, vessel 12 is provided with a make-up gas inlet 80 communicating with a make-up gas line 82 having an axial flow valve 84 downstream of inlet 80. A burst plate outlet 86 and a pressure relief outlet 88 are provided in accordance with conventional practices to maintain the pressure within the vessel within predetermined, safe operating limits. With reference to FIG. 5, line 82 is arranged to be connected to a supply source of make-up gas (not shown) and includes a ball valve 90 to permit the manual activation of gas flow, a regulator 92 and a check valve 94 to control gas flow. Line 82 is connected to inlet 80 and back pressure line spool 96 at Tee joint 98. Axial flow valve 84 is provided with an independent source of make-up gas, in the form of a nitrogen cylinder 100, to supply gas under pressure to the vessel in the event that the main source of gas is interrupted for some reason.
A well production inlet and outlet valve assembly 110 is comprised of inlet piping spool 112 which is connected to production inlet 14, an outlet piping spool 114 which is connected to production outlet 16, and valve actuator 116. A flapper or check valve 118 is disposed between inlet piping spool 112 and production inlet 14 while a dump valve 120 is disposed between outlet piping spool 114 and production outlet 16. Valve actuator 116 controls valve 120. As best illustrated in FIG. 7, a subsidiary pressure line 122 extends from line 82 to pneumatic valve actuator 116. A pressure regulator 124 and solenoid controlled valve 126 are connected in series in line 122. The solenoid associated with valve 126 is connected with a suitable source of electrical energy via conductor 130 (FIG. 2) which is controlled by computer 28 and, thus, valve 126 permits valve actuator 116 to be controlled from a remote location by an operator or computer. Thus, when solenoid controlled valve 126 is opened, regulator 124 supplies gas under pressure to valve actuator 116, causing valve actuator 116 to operate valve 120. Outlet piping spool 114 is equipped with a back flow valve to prevent back flow into vessel 12. It will be noted from FIG. 2 that load cell 24 is electrically connected to computer 28 via conductor 132.
The internal construction of the vessel will now be described with reference to FIGS. 8A, 8B, 9 and 10. With reference firstly to FIGS. 8A, 8B and 9, a first internal conduit 140 extends radially inwardly of the vessel from inlet 14 to a vertical conduit 142 of enlarged diameter coaxially disposed within vessel 12. The bottom end 144 of conduit 142 is closed by a plate 146. Conduit 142 is secured to the interior walls of the vessel by three radially outwardly extending arms 148 formed of angle iron or other such suitable material. A cap 150 is secured to the upper end 152 of conduit 142 in axially spaced relation to outlet opening 154 thereof to permit well production to spill over the edges of the opening onto a series of trays described below. Conduit 142 is also perorated along its length to provide additional discharge openings 156 to enhance both degassing and mixing of the well production.
A plurality of inclined mixing trays 160 (three are shown) are secured to vertical conduit 142 in vertically spaced, staggered relation beneath cap 150 such that well production flowing over the supper edge 154 and through apertures 156 of conduit 142 flows into the uppermost tray and then cascades into each of the trays positioned therebeneath to further breakup, mix and degas the well production. Like conduit 142, the bottoms of trays 160 may be perforated to further enhance mixing and degassing. While the degree of inclination of mixing trays 160 is not critical, an inclination of 15 degrees has been found to be suitable.
With reference to FIG. 10, an internal discharge conduit 170 is formed with a radially inwardly extending portion 172 connected to well production outlet and an axially downwardly extending portion 174 extending into the lower end portion 44 of vessel 12. Thus, when discharge or dump valve 120 is opened, the pressure within vessel 12 forces well production within the vessel outwardly thereof through conduit 170. Since solids will, over a period of time come out of suspension and will accumulate at the bottom of the vessel, a drain 176 and flushing means 178 are provided for "desanding" the vessel. Flushing means 178 includes a circular fluid conduit or ring 180 concentrically disposed within the lower end portion of the vessel and connected to a source of water via conduit 182. The ring is provided with a plurality of equally angularly spaced, downwardly directed spray nozzles 184. Thus, water may be pumped through conduit 182 and into ring 180 and out nozzles 184 to flush accumulated solids out drain 176.
With reference to FIG. 9, sample outlet 18 is connected to a radially inwardly extending conduit 190 having a pair of arms 192, each having a first laterally outwardly extending portion 194 and a second portion 196 extending at a right angle to the first portion. Each portion 196 is provided with an elongated, downwardly directed intake opening 198.
The sample monitoring apparatus 22 will now be described with reference to FIGS. 1 and 11 to 12. This apparatus provides a means of electromagnetically determining the percentage water content of the well production. As best shown in FIG. 1, a sample flow path includes a first conduit 200 connecting sample outlet 18 and a pump 202 driven by a motor 204 which may be selectively controlled by computer 28 via control line 206 (FIG. 2) if so desired. The flow path further includes a return conduit 208 connecting the high pressure side of the pump to sample return inlet 20 of the vessel. Conduit 208 includes a vertically extending monitoring portion 210 in which the antenna of a suitable commercially available oil/water monitor 212 is disposed. The monitor emits an electromagnetic signal into the fluid stream and a sensor associated with the monitor receives the signal and produces an electrical output representative of the percentage water content of the sample in the flow path. This signal is communicated to computer 28 via conductor 214. Since oil and water normally differ in density, high water content, gravity and low fluid velocities may allow stratification or water to settle out in a horizontal pipe. To avoid inaccurate readings resulting from these factors, the probe is desirably installed in a vertical section of pipe and fluid velocities are maintained at a level which ensures turbulent flow and good mixing of the constituents of the sample.
A sample tap 216 may be provided to allow manual samples to be taken to confirm the accuracy of the results produced by the apparatus. In addition, a sample container 220 may be provided to store a small sample of well production from each of several cycles of operation to allow both manual sampling or the well production and confirming the results of the several cycles by circulating the contents of the sample container through the test loop. To that end, there is provided a first conduit 222 extending from the high pressure side of the pump 202 to container 200 and a second inlet conduit 224 in parellel with the first. The latter conduit is intended or maintenance purposes. The former is provided with a solenoid operated valve 206 having an electrical control line 228 under the control of the computer. A discharge conduit 230 connects container 220 to line 200. A shown in FIGS. 11, 12 and 13, the monitoring apparatus is mounted on a support skid 232.
OPERATION
It will be understood at the outset that the vessel is maintained at a predetermined operating pressure of 175 psi with overpressure conditions being eliminated by the burst plate and pressure relief valves. In addition, once energized, load cell 24 and oil/water monitor 212 continuously produce and transmit to the computer electrical output signals representative of the weight of the vessel and contents and the percentage water content, respectively. Still further pump 202 may operate continuously if so desired. Alternatively, motor 204 may be activated only in that portion of the operating cycle in which the oil/water monitor output is required.
The percentage solids content of each well to be monitored will have been predetermined and input into the computer and each such well will have been assigned a "bottom line" weight and a "top Line" weight. The "bottom line" weight is the weight at which the computer will activate a timer (not shown) while the "top line" weight is the weight at which the computer will stop the timer. Thus, since the difference between the bottom and top line weight will be known in advance for each well, the well flow rate of the well production into the vessel can be readily determined simply by dividing the difference by the time interval required for the weight of the vessel to go from the bottom line weight to the top line weight. Valves 118, 120 will be assumed to be initially closed an valve 226 open.
At an appropriate time, determined by initial conditions input into the computer, the computer will cause a signal to be transmitted to solenoid 126 via line 130 which will cause valve actuator 116 to open well production inlet valve 118. Well production will then enter production inlet 14, conduit 140 and 142, discharge onto trays 160, this serving to degas and agitate or mix the well production, and then fall under gravity to the bottom of the vessel. When the output of the load cell indicates a weight equal to the bottom line weight, the computer will activate a timer. During this time, valve 226 is open and therefore a sample of the well production is allowed to enter sample container 220. When the output of the load cell indicates a weight equal to the top line weight, the computer will deactivate the timer, store the elapsed time and cause a signal to be transmitted to solenoid 126 to close valve 118 and open dump valve 120 to discharge the vessel and a signal via line 228 to close solenoid operated valve 226.
While the vessel was being charged, a sample of the well production was drawn from the vessel via conduits 190 and 192 in the vessel, into the sample flow path by pump 202 and passed oil/monitor 212 whose output the computer read via line 214 and stored. Having thus determined the total well production flow rate, as discussed earlier, obtained a reading of the percentage water content from probe 212 and having in memory the percentage solids contents, it is a simple matter for the computer to convert the three factors to common units and determine the percentage oil content of the well being monitored.
The following example will illustrate the calculations involved. If the recorded flow rate of well production into vessel 12 was determined to be 1625 kilograms per hour, these units can be converted into "cubic meters per day" simply by multiplying 1625 kilograms per hour by 24 hours by 1000 kilograms per cubic meter to provide desired measurement units resulting in 39 cubic meters per day. If probe 212 senses a water content of 27% and the solids content has been predetermined to be 0.25%, the following calculations can be made based upon the previous determination of a flow rate of 39 cubic meters per day:
Daily water flow rate=
39 cubic meters/day×0.27 (%water)=10.53 cubic meters of water/day
Daily Solids flow rate=
39 cubic meters/day×0.025 (%solids)=0.097 cubic meters of sand/day
Daily Oil flow rate=
total daily production-production of water less daily production of solids: 39-10.53-0.097=28.373 cubic meters per day.
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A method of measuring the oil content in the gross oil production of an oil well in which the percentage of solids content thereof is known, comprises the steps of introducing a predetermined weight of well production into said vessel, determining the time interval required to introduce said predetermined weight of well production into said vessel, determining the total well production flow rate of said well production into said vessel during said time interval, electromagnetically determining the percentage water content in said well production, determining from said percentage water content the water flow rate into said vessel during said time interval, determining from said known percentage solids content the solids flow rate into said vessel during said time interval, and determining the percentage oil content in said well production by deducting said solids flow rate and said water flow rate from said total well production flow rate.
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BACKGROUND OF THE INVENTION
The present invention pertains to digital span data transmission circuitry and more particularly to a fault tolerant transmission circuit arrangement for use with a switching network in a CPU controlled telecommunications switching system.
Typically, circuits for transmitting unipolar switching network data to bipolar data compatible with use by modern digital span equipment is implemented using discrete components. These circuits are large in size and consume a relatively large amount of power.
Public policy requires that a telecommunications switching system provide virtually uninterrupted service to the public over long periods of time. Simple solutions to this problem include mere duplication of circuitry. Given the background of the present technology as being discrete components, as mentioned above, duplication of circuitry will lead to more size requirements and power consumption.
Accordingly, it is the object of the present invention to provide a fault tolerant transmission circuit arrangement, which is small in size and requires a small amount of power, for translating unipolar switching network data to data compatible with a digital span of a telecommunications switching system.
SUMMARY OF THE INVENTION
In a telecommunications switching system which has a CPU, a transmission circuit arrangement is connected between a digital span and a switching network of the switching system. The transmission circuit arrangement provides a fault tolerant method for converting unipolar switching network data to bipolar digital span data.
The transmission circuit arrangement includes first and second transmission circuit copies. In addition, first and second corresponding transformers are respectively connected between the first and second transmission circuit copies and the digital span. Each transmission circuit copy is respectively connected to the transformer by first and second output leads. The switching network is connected to each transmission circuit copy via corresponding first and second input leads. The switching network operates to alternately transmit first and second input signals of a first value via these leads to each transmission circuit copy.
Each transmission circuit copy has a first current controller which is connected to the first input lead and to the first and second output leads. The first current controller operates to connect the first input lead to the second output lead. The first current controller also operates to permit a predetermined current flow from the first to the second output lead via the corresponding transformer.
Each transmission circuit copy also includes a second current controller which is connected to the second input lead and to the first and second output leads. The second current controller operates to connect the second input lead to the first output lead. The second current controller also operates to permit a predetermined current flow from the first to the second output lead via the corresponding transformer.
Each transmission circuit copy also includes a voltage controller which is connected to the CPU, to a voltage source, and to the first and second current controllers. The voltage controller operates in response to the CPU to enable the first transmission circuit copy while simultaneously disabling the second transmission circuit copy. The voltage controller alternatively operates in response to the CPU to disable the first transmission circuit copy and simultaneously to enable the second transmission circuit copy.
Lastly, each transmission circuit copy includes an impedance controller which is connected to the CPU, to the corresponding transformer via a terminal lead and to the voltage controller. The impedance controller operates in response to the CPU to connect a high impedance to the terminal lead in order to disable the corresponding transmission circuit copy or alternatively the impedance controller operates in response to the CPU to connect a low impedance to the terminal lead to enable the corresponding transmission circuit copy.
The first and second current controllers of each transmission circuit copy are alternately operated to produce the required bipolar data for the digital span.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a telecommunications switching system embodying the present invention.
FIG. 2 is a block diagram of the transmission circuit of the present invention shown for simplex or duplex operation.
FIG. 3 is a schematic diagram of the transmit driver hybrid.
FIG. 4 is a schematic diagram of the analog switch hybrid.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a time-space-time digital switching network along with the corresponding common control is shown. Telephone subscribers, such as subscribers 1 and 2, are shown connected to analog line unit 13. Analog line unit 13 is connected to both copies of the analog control unit 14 and 14'. Originating time switches 20 and 20' are connected to duplex pair of space switch units 30 and 30' which are in turn connected to the terminating time switch 21 and 21'. Time switch and control units 21 and 21' are connected to analog control unit 14 and 14' and ultimately to the telephone subscribers 1 and 2 via analog line circuit 13.
Digital control units 15 and 15' connect the digital spans to the switching network. Digital span equipment may be implemented using a model 9004 T1 digital span manufactured by GTE Lenkurt Inc. Similarly, analog trunk unit 16 connects trunk circuits to the digital switching network via analog control units 17 and 17'.
A peripheral processor CPU 70 controls the digital switching network and digital and analog control units. Analog line unit 13 and a duplex pair of analog control units 14 and 14' interface to telephone subscribers directly. A duplicate pair of digital control units 15 and 15' control the incoming PCM data from the digital spans. Similarly, the analog trunk unit 16 and a duplex pair of analog control units 17 and 17' interface to trunk circuits. The analog and digital control units are each duplicated for reliability purposes.
Referring to FIG. 2, a transmit driver along with an analog switch and an equalization and padding network is shown. It is to be noted that although FIG. 2 depicts a single copy of each of the above mentioned devices, there may be duplex copies, copy 0 and copy 1, located in digital control units (DCUs) 15 and 15', respectively. These transmission circuit copies provide a duplex link between the switching network and each digital span.
Transmit driver 225 is connected to the switching network via the +DRV and D-DRV leads. These leads are driven by open collector peripheral drivers capable of handling 300 MA of current. Alternate logic ones appear on the +DRV and -DRV leads, connected to transmit driver 225.
Transmit driver 225 converts the unipolar signals of the switching network to bipolar signals required by the digital span. Transmit drive 225 is connected to an inductive-resistive network made up of inductor 229, resistor 250, resistor 251, and transformers 247 and 248. The output of this inductive-resistive network provides overshoot and undershoot on the rising and falling edges of the pulses from transmit driver 225. The voltage input to the inductive-resistive network is approximately 6 volts, whereas the pulses transmitted from the secondary winding of transformer 248 are approximately 12 volts.
A center tap connection of transformer 248 conducts the above mentioned output pulses to equalization and padding network 249. Equalization and padding network 249 provides an approximately 6 db attenuation for a 100 ohm load. This network provides for less attenuation at higher frequencies. The equalization and padding network 249 compensates for increased capacitive loading as cable distances between this circuit and the digital span cross-connect increase.
The output of equalization and padding network 249 is connected through transformer 228 to the digital span. For a simplex configuration, lead XFMS0 of transformer 228 would be connected directly to ground and the VC leads of transmit driver 225 would be connected directly to a voltage source. For the duplex configuration mentioned above, the XFMS0 lead of transformer 228 would be connected to analog switch 246. The VC lead of transmit driver 225 would also be connected to analog switch 246.
A peripheral processor (CPU) is connected to an analog switch 246 of each transmission circuit copy. The CPU operates the analog switches 246 of each copy, such that, one analog switch (and therefore transmission circuit) is active and operating and the other copy of the duplex pair is ready and standby. Analog switch 246 is connected to the CPU by the SBY lead. A logic 0 on the SBY lead indicates that the transmission circuit is in the operating and active state, whereas a logic 1 on the SBY lead indicates that it is in the ready and standby state. In the duplex configuration, analog switch 246 if enabled by the peripheral processor, produces a low impedance path to ground via the XFMS0 lead, which is connected to the center tap connection of transformer 248. For the condition in which this transmitter circuit is disabled, analog switch 246 provides a high impedance condition on the XFMS0 lead, which is connected to transformer 228, thereby disabling any transmission.
The transmit driver 225, the analog switch 246 and the equalization and padding network 249 may each comprise a thick film hybrid.
Referring to FIG. 3, a schematic diagram of the transmit driver of FIG. 2 is shown. When neither input +DRV or -DRV is being driven with data transmission from the switching network, resistor R7 will provide a 100 ohm termination to transformer 228. This condition is required for a digital span line that is not transmitting data. This condition is a switching industry standard.
For the condition that this transmission circuit is enabled by the peripheral processor, the VC leads will be at +12 volts. If no data is being transmitted via the +DRV lead, no current will flow through diode CR1 or resistor R5. Therefore, 200 ohm resistor R3 will pull the base of transistor Q1 to approximately +12 volts. This will turn off Q1. Although Q1 will not completely turn off, the current flow through it will be greatly reduced.
Similarly, if no data is being transmitted via the -DRV lead, no current will flow through diode CR3 or resistor R6. Therefore, 200 ohm resistor R4 will pull the base of transistor Q2 to approximately +12 volts. Since little current will flow through transistor Q2, Q2 will be essentially turned off.
Next, if data is transmitted from the switching network via the +DRV lead, the +DRV lead will be pulled to ground by a pulse. As a result, the T1 lead, which is connected ultimately to output transformer 228, will be connected to ground on the +DRV lead via diode CR2. Transistor Q2 remains turned off. Also, current will flow through resistor R3, resistor R5 and diode CR1. Resistors R3 and R5 form a voltage divider, which brings the base of transistor Q1 from its previous +12 volt level to approximately a +8 volt level. Therefore, transistor Q1 will be turned on and current will flow through resistor R1 (25 ohms), through the emitter and through the collector of transistor Q1.
As a result, transistor Q1 functions as a current source. Approximately, a voltage of +8.5 will appear at the emitter of transistor Q1. Resistor R1, nominally 25 ohms, is trimmed, such that when Q1 is turned on, approximately 120 MA of current will flow through resistor R1, through the emitter and out of the collector of transistor Q1. Approximately one-half of the 120 MA of current will flow out of the transmit driver circuit via the TO lead via transistor Q1. The other one-half of the 120 MA of current will flow through resistor R7 and out via the R lead. The current (60 MA) will be transmitted via the TO lead to transformer 248. Since the impedance of the line is essentially 100 ohm, a 6 volt pulse will be present at the input of transformer 248. The direction of the current flow is from transistor Q1 via the TO lead to transformer 248.
As previously mentioned, when the +DRV lead is not transmitting data, the base of transistor Q1 is at approximately +12 volts. This condition results from a small current flow through resistors R3 and R8 to ground. Therefore, the voltage at the base of transistor Q1 is in actuality approximately +11.2 volts. As a result, a small current flows through the base-emitter junction of transistor Q1 and Q1 is never completely turned off. The base-emitter capacitance of transistor Q1 is nearly charged in this condition and this allows transistor Q1 to turn on rapidly.
Next, if data is transmitted from the switching network via the -DRV lead, the -DRV lead will be pulled to ground by a pulse. As a result, the TO lead, which is ultimately connected to output transformer 288, will be connected to ground on the -DRV lead via diode CR4. Transistor Q1 remains turned off. Current will flow through resistors R4 and R6 and diode CR3. Resistors R4 and R6 form a voltage divider, similar to resistors R3 and R5, as mentioned above.
For data transmission on the -DRV lead, resistor R2 and transistor Q2 form a current source, similar to resistor R1 and Q1, as above. Current is now sourced from Q2 and out via the T1 lead, via transformer 247 to output transformer 228. Resistors R4 and R9 play similar functions to resistor R3 and R8, as mentioned above. Resistors R1, R3, R5 and R8 are analogous in function and value to resistors R2, R4, R6 and R9.
Since the current flow produced by transistors Q1 and Q2 is in opposite directions with respect to transformer 248, the current flow from transmitter Q1 will produce the required negative pulses and the current flow from transistor Q2 will produce the required positive pulses.
Referring to FIG. 4, a schematic diagram of the analog switch of FIG. 2 is shown. The SBY lead is connected to the peripheral processor (CPU). For a logic 0 on the SBY lead, the analog switch and consequentially the transmit driver is enabled to provide active transmission by grounding the output lead XFMS0. For a logic 1 on the SBY lead, the analog switch and the transmit driver are disabled from active transmission and remain in the ready and standby condition.
When the SBY lead is at logic 0, current will flow through resistor R12 and through the base of transistor Q12. As a result, transistor Q12 is turned on. The emitter of transistor Q12 is biased to +12 volts. Also, the collector of transistor Q12 will be at approximately 12 volts, and this voltage will be supplied to the transmit driver via the VC lead. In addition, current will flow through resistor R11 and turning on transistor Q11 as a result.
Now turning to an examination of the output XFMS0, which enables its associated transmit driver. For XFMS0 to be connected to ground, there must be a path through either Q11 or Q13 to ground. Since transistor Q12 is turned on and the XFMS0 lead is operating above ground potential, current will flow from the collector of transistor Q12, through resistor R14 and to the base of transistor Q13, turning it on. Therefore, current will flow from the XFMS0 lead through the collector-emitter junction of transistor Q13, through diode CR12 to the ground connection of diode CR12. As a result, a low impedance connection is provided to enable output transformer 228 via the XFMS0 lead.
In the situation when transistor Q12 is turned on and the XFMS0 lead is operating below ground potential, current must flow out of the XFMS0 lead. Current will flow out of the collector of transistor Q12, through resistor R11 to the base of transistor Q11, turning on transistor Q11. Current flows from the emitter of transistor Q11, through diode CR11 and out of the XFMS0 lead. Therefore, a low impedance path is provided regardless of whether current flow is outward or inward from the analog switch via the XFMS0 lead, corresponding to negative or positive pulses from the transmit driver.
Now, if the SBY lead is at logic 1, indicating the corresponding transmit driver is to be disabled and act as a ready and standby copy, no current will flow through transistor Q12. Resistors R12 and R13 and a pull-up resistor (not shown) will hold transistor Q12 turned off. With transistor Q12 turned off, pull-down resistor R15 will place approximately -12 volts on the VC lead. As a result, the -12 volts on the VC lead will disable the corresponding transmit driver.
In addition, a high impedance condition is required on the XFMS0 lead to disable the associated copy of the transmit driver from the digital span, that is, no current flowing via the XFMS0 lead. There must be no low impedance path for current flow in this case.
If a positive voltage is applied to the XFMS0 lead, causing current to attempt to flow into the analog switch, the collector of transistor Q13 will be reversed biased. Therefore, no current can flow through the transistor Q13 junction, since the breakdown voltage of the base-collector junction exceeds the reverse bias applied voltage.
No current can flow via the XFMS0 lead through transistor Q11, since CR11 prevents any current flow in this direction. Therefore, if the XFMS0 lead has a positive voltage, both possible current paths are blocked by diode CR11 and transistor Q13, respectively.
If a negative voltage is applied to the XFMS0 lead, any path for current to flow out of the analog switch via the XFMS0 must be blocked. For current to flow through the base-collector junction of transistor Q13, the current may come from two sources. First, the current may flow via resistor R14 to the base of transistor Q13 or second, current may flow through the emitter-collector junction of transistor Q13. Diode CR12 blocks any current flow through the emitter-collector junction of Q13. For the first case, resistor R14 is approximately 1400 ohms which creates a high impedance path. In addition, transistor Q12 is turned off, so no current may flow through resistor R14 from Q12. Vitually no current can flow through the path of resistors R15 and R14, since resistor R15 is approximately 16000 ohms, a high impedance.
No current can flow through resistor R1 via the emitter-base junction of transistor Q11 because of diode CR11. No current can flow through resistor R11 via the collector-base junction of transistor Q11 because that junction is reversed biased and the breakdown voltage will not be exceeded by the reverse bias. Therefore, there is no low impedance path for current to flow out of transistors Q13 via the XFMS0 lead.
If the negative voltage remains applied to the XFMS0 lead, no current path must also exist through transistor Q11. Since the voltage at the base of transistor Q11 is approximately at -12 volts due to resistor R15, the base-emitter junction of Q11 is reversed biased. Transistor Q11 is turned off and no current flows through the collector-emitter junction or through the base-emitter junction of Q11.
Therefore, if the SBY lead is at logic 1, the XFMS0 lead will always be a high impedance output.
Although the preferred embodiment of the invention has been illustrated, and that form described in detail, it will be readily apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.
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In a telecommunications switching system, a thick film digital span circuit arrangement is connected between a digital span and a switching network of the switching system. The transmission circuit arrangement converts unipolar switching network data to bipolar data for use by the digital span. The telecommunications switching system provides for duplicated data transmission to the digital span. Duplicated transmission circuits are arranged in an active/standby configuration under CPU control without affecting the overall impedance seen by the digital span.
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FIELD OF THE INVENTION
[0001] The present invention relates to automated biological testing systems and more particularly to a system for generating data for the analysis of the visual characteristics of cytological specimens, and in particular biological specimens obtained for Papanicolaou (Pap) testing and prepared as a monolayer specimen.
BACKGROUND OF THE INVENTION
[0002] In the art, there are known techniques for the machine-aided evaluation of biological or medical specimens. Many of these embody the application of optical decomposition for image evaluation.
[0003] Bacus, in U.S. Pat. No. 5,202,931, teaches an optical method and apparatus for protein quantification that utilizes two band-pass optical filters centred at 500 nm and 650 nm. The filters are optimized to produce maximal contrast between cellular nuclei with and without diaminobenzidine precipitate staining. While the Bacus invention is effective for application in a quantitative immunohistochemical assay, the Bacus method is not suitable to capture and exploit the crucial properties of a Papanicolaou (Pap) test for automated evaluation. Specifically, the Pap test evaluation does not reduce to a simple binary decision, i.e. either a “yes” or a “no” for the presence of a specific staining precipitate. The Pap test evaluation requires the synthesis of a highly-variable and wide-ranging set of visual and clinical circumstances in order to render a diagnostically reliable outcome. From the perspective of machine automation, these visual circumstances are the complete range of mathematical “features” which are raised as a consequence of the standardized staining protocol. Thus, any application of the image analysis techniques to the Pap test must be constrained to this stain and must extract the full range of features that replicate the appreciation gained through human visual evaluation.
[0004] In U.S. Pat. No. 4,191,940, Polcyn et al. discloses a technique for the use of a decomposed set of optical wavelengths for a multivariate analysis of cell identification. Though powerful in its own right, the Polcyn technique is limited to the separation of different categories of material based on simple absorption properties alone. As described above, the Pap test is much more subtle and complex. The optical absorption properties represent only the beginning of the chain of analysis that ultimately leads to a medical diagnosis. Given the complexity of the cervical cytology application it is usual to apply what is known as a “classical” image analysis consisting of segmentation, feature extraction and classification. In this way only is it possible to arrive at a precise and accurate classification of the myriad components that reside within a gynaecological specimen.
[0005] The complexity of the Pap test automation task is borne out in U.S. Pat. No. 5,287,272 by Rutenberg et al. Rutenberg et al. teaches a method and apparatus that draws a clear distinction between the conventional Pap smear and the thin layer or monolayer specimens that are the subject of the present invention. According to Rutenberg et al., the application of cytological image analysis is severely constrained by limitations the conventional Pap smear. Unlike the controlled monolayer specimen, the conventional smear is characterized by irregular cell groupings and distributions, thick, overlying cell clusters and occluding debris. By avoiding the monolayer preparation, Rutenberg et al. are restricted to a level of image analysis that is limited in its sensitivity and specificity.
[0006] The subject invention addresses the problems and limitations associated with the prior art. The present invention utilizes a monolayer specimen for automated cytological analysis and advantageously features a segmentation phase with improved accuracy and produces a complex and extensive range of extracted features. This allows a more refined approach to the problem of cytological classification and improves performance and provides cost savings. The image collection component of this invention also features the creation of a “pseudo-coloured” image that retains the bulk of the visual cues required by cyto-technologists for interactive review purposes.
[0007] Constrained by the nature of the preparation, the fixed protocol of the biological staining and the necessity to bridge the gap between machine processing and human evaluation, the present invention comprises a refined set of optical filters used in conjunction with a high-speed imaging system, processing hardware, discriminant-analysis techniques and mathematical measures to pre-process images for cellular identification. The images gathered generated according to the invention are also useful for human-interactive review, a further advantage of the system.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides an imaging system having the capability to simultaneously capture the same scene in multiple spectral bands, and comprises a system having an integrated optical system, image collection devices and a method for pre-processing and analyzing human cervical cytology specimens or samples. The system is particularly suited for specimens prepared in the form of thin-layers or monolayers. The image data produced by the system is suitable for automated eassessment of the clinically-relevant state of the specimen and also permits the use of human-expert review for confirmation or to establish diagnostic grade and clinical action.
[0009] The system according to the present invention comprises three principal components (a) optical hardware (b) electronic hardware and (c) measurement and analysis procedures and methods. The optical hardware provides for illumination of the specimen, magnifies the cellular components, separates the appropriate wavelengths and directs the separated wavelengths for electronic digitization. The electronic hardware provides for the translation of the optical images into digital information and for the overall control of the processing steps according to the invention. The measurement and analysis procedures preferably comprise processing steps embedded in hardware for pre-processing the information for classification.
[0010] This subject invention is intended to function with components described in co-pending patent applications entitled Automated Scanning of Microscope Slides International Patent Application No. CA96/00475 filed Jul. 18, 1996 and U.S. Pat. Application No. 60/001,220 filed Jul. 19, 1995, Pipeline Processor for Medical and Biological Applications U.S. patent application Ser. No. 08/683,440 filed Jul. 18, 1996 and U.S. Patent Application No. 60/001,219 filed Jul. 19, 1995, Multi-Spectral Segmentation International Patent Application No. CA96/00477 filed Jul. 18, 1996 and U.S. Patent Application No. 60/001,221 filed Jul. 19 , 1995 , Neural-Network Assisted Multi-Spectral Segmentation International Patent Application No. CA96/00619 filed Sep. 18, 1996 and U.S. Patent Application No. 60/003,964 filed Sep. 19, 1995, Automated Focus System International Patent Application No. CA96/00476 filed Jul. 18, 1996 and Window Texture Extraction International Patent Application No. CA96/00478 filed Jul. 18, 1996 and U.S. Patent Application No. 60/001,216 filed Jul. 19, 1995, all in the name of the common owner.
[0011] In a first aspect, the present invention provides an imaging system for capturing multi-spectral image data of a cytological specimen, said imaging system comprising: (a) an optical stage having a light source for illuminating the specimen, and optical means for producing images of the illuminated specimen in a plurality of spectral bands; (b) an image capture camera having means for simultaneously capturing said spectral images and generating corresponding electrical signals corresponding to said captured spectral images; (c) controller means for controlling the operation of said image capture camera and said light source, said controller means having means for converting said electrical signals corresponding to said captured spectral images into a data form suitable for further processing.
[0012] In another aspect, the present invention provides a method for generating multi-spectral image data for cytological specimen, said method comprising the steps of: (a) exposing said cytological specimen to a short burst of broad-band light; (b) separating said burst of broad-band light into a plurality of spectral bands; (c) simultaneously capturing an image for each of said spectral bands and generating electrical signals corresponding to each of said captured spectral images; (d) converting the electrical signals corresponding to said captured spectral images into a data form suitable for further processing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Reference will now be made, by way of example, to the accompanying drawings which show preferred embodiments of the present invention, and in which:
[0014] [0014]FIG. 1 shows in block diagram form a multi-spectral imaging system according to the present invention;
[0015] [0015]FIG. 2 shows in a diagrammatic form an optical pathway for the multi-spectral imaging system of FIG. 1;
[0016] [0016]FIG. 3 shows spectral bands for images captured;
[0017] [0017]FIG. 4 shows in block diagram form an electronic circuit for the multi-spectral imaging system according to the present invention; and
[0018] [0018]FIG. 5 shows in block diagram a camera for the multi-spectral imaging system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Reference is first made to FIG. 1 which shows in block diagram form a multi-spectral imaging system 1 according to the present invention. The multi-spectral imaging system 1 comprises an optical stage 3 , an image capture camera 5 , and a processing stage 7 and an electronic control system 8 .
[0020] As will be described, the multi-spectral imaging system 1 provides a method and apparatus for generating data representing the visual characteristics of a cytological specimen denoted by reference S in FIG. 1. According to one aspect of the invention, the data is generated in a form which facilitates further processing and analysis of the characteristics of the cytological specimen S and is particularly suited for monolayer specimens.
[0021] Reference is made to FIG. 2 which shows the optical stage 3 in more detail. The optical stage 3 provides the optical path for the system 1 . The optical stage 3 includes a high-intensity electrical discharge tube 11 , a condensing lens 13 , a fibre-optic bundle 15 , a small aperture 17 , an objection lens 19 , a telan lens 21 , and a prism assembly 23 . The prism assembly 23 includes an optical element 25 with filters 27 , 29 , 31 .
[0022] The electrical discharge tube 11 is operated as a stroboscopic lamp. Preferably, the discharge tube 11 produces a short intense pulse of light lasting less than 6 microseconds. The lamp 11 is selected to have a broad-band spectral output covering a range between 400 nm and 700 nm. As will be described, the optical filters 27 , 29 , 31 select the appropriate wavelengths for image formation from this broad range. The pulse of light must have sufficient intensity to accommodate losses from the intervening optics. A short light pulse is preferred because it allows the multi-spectral system 1 : (a) to isolate from the image mechanical vibrations that result in mechanical velocities of less than 0.08 meters per second at the microscope slide level, (b) to operate the CCD array cameras (see FIG. 4 below) without electronic or mechanical shutters thereby increasing the rate of image acquisition, and (c) to illuminate the sample without the photo-bleaching or heat damage effects associated with continuous illumination sources.
[0023] The light emitted by the strobe lamp 11 is coupled to the fibre-optic bundle 15 by the condensing lens 13 . The condensing lens 13 comprises a known optical element which functions to gather, concentrate, collimate and project the light emitted by the strobe lamp 11 onto the face of a fibre-optic bundle 15 . The fibre-optic bundle 15 preferably comprises a tightly-packed group of glass fibre-optic cables. The primary function of the fibre-optic bundle 15 is to couple the light from the lamp 11 to illuminate the specimen S. The use of a fibre-optic bundle 15 as a light guide is preferred because it allows the strobe lamp 11 to be operated at some distance from the object plane, i.e. specimen S, of the system 1 . Advantageously, this arrangement reduces the potential occurrence of electrical interference from the intense electrical discharges occurring at the lamp 11 . The flexibility of the fibre-optic bundle 15 also permits the use of indirect optical paths from the strobe lamp 11 to the object plane and thereby eases design considerations.
[0024] As shown in FIG. 2, the small aperture 17 is centred on the optical axis of the objective lens 19 at the exit face of the fibre-optic bundle 15 . This arrangement is preferred because it restricts the illumination to the region immediately surrounding the region of interest (denoted by 16 in FIG. 2) and advantageously reduces the contrast-reduction effects associated with internal reflections within the optical components and yields better-resolved images.
[0025] The light which passes through the specimen S is collected by an objective lens 19 . The objective lens 19 preferably comprises an infinite-conjugate optical system. The objective lens 19 preferably has moderate nominal magnification (×10 or ×20) and a numerical aperture of 0.4 NA-0.75 NA. The lens 19 is brought into the correct or optimal focus for the nuclear material contained in the specimen S within the field of view by means of an automatic focus module 20 . The automatic focus module 20 is preferably implemented as the apparatus and method as substantially described in co-pending PCT Patent Application No. CA96/00476 filed in the name of the common owner. The automatic focus techniques which control the focus mechanism are used in conjunction with a method of image formation by spectral separation as will be described below in further detail. As described in co-pending International Patent Application No. CA96/00476 (which is hereby incorporated by reference) the automatic focus module 20 comprises a servo-mechanical mechanism having a magnetically-suspended voice-coil actuator 47 (FIG. 4) which supports the objective lens 19 . The voice-coil actuator 47 receives motion control instructions from the electronic control system 8 based upon the mathematical calculations and process control steps as described in the co-pending application for an automated focus system.
[0026] The objective lens 19 preferably comprises an infinite-conjugate objective lens which produces a real image of the specimen S that is projected (theoretically) to an infinite distance. In the optical stage 3 the light emitted from the infinite-conjugate lens 19 is subsequently gathered by the telan lens 21 . The function of the telan lens 21 is to create and project a real image to a finite position within the prism assembly 23 . An infinite-conjugate system is preferred for the following reasons. First, the magnification is a function only of the ratio of the focal length of the objective lens 19 and the telan lens 21 . This means that the magnification is not sensitive to the relative displacement of the objective lens 19 and so the motion of the objective lens 19 during the automatic focusing will have negligible effect upon the optical magnification of the system 1 . This is in contrast to a conventional DIN microscope system in which the magnification is based on a specific tube length (e.g. 160 mm with 45 mm parfocal length). A second advantage of the present arrangement is that the light between the objective lens 19 and the telan lens 21 is collimated. Thus, it is possible to introduce additional optical elements, such as beam-splitters, without suffering or incurring spherical aberrations in the final image. Thirdly, the infinite-conjugate objective lens 19 allows the simple alteration of the magnification of the real image by a substitution of an objective lens of a different focal length. Unlike conventional finite tube length systems, the alteration of the arrangement shown in FIG. 2 would carry no penalty with respect to the quality of the image obtained from the specimen S.
[0027] The image re-formed by the telan lens 21 is projected into the prism assembly 23 . The prism assembly 23 comprises the internal optical prism element 25 with the three optical filters 27 , 29 , 31 which are optically coupled to respective faces of the prism assembly 23 . The function of the prism assembly 25 is to select a series of three narrow optical wavelength representations of the image. The three optical wavelengths are based in part on spectral decomposition principles as described by G. Coli et al. in Olivetti Research and Technology Review Vol. 8, No. 33 (1987).
[0028] The optical prism element 25 comprises a set of glass wedges coated with dielectric film stacks to create the interference band-pass optical filters 27 , 29 , 31 . By selecting wedge angles and dielectric film coatings the prism 23 will simultaneously produce three images from the same scene in each of three narrow optical regions. The width of each of these optical regions is preferably 10 nm with a transmission efficiency of at least 50% within the optical band. The three centre wavelengths for these bands are selected as 530 nm (I), 577 nm (II) and 630 nm (III) as shown in FIG. 3.
[0029] The arrangement according to this aspect of the invention has specific advantages for the acquisition and processing of images derived from Papanicolaou-stained human epithelial cells, such as those encountered in the Pap test. The prism assembly 23 features a compact and robust design with very high natural vibration frequencies. Thus the prism assembly 23 is immune from the much lower frequencies that typify ambient mechanical vibrations. Once assembled and aligned, the prism assembly 23 is highly stable against thermal or mechanical drift and as such reduces additional servicing over its useful lifetime.
[0030] In another aspect, the prism simultaneously produces three spectrally-selective images thus conferring a factor of three reduction in the acquisition time for images needed in the processing stages. In addition, the simultaneous capture is advantageous because it reduces the number of strobe flashes required of the lamp 11 by a factor of three. This, in turn, increases the operating life of the lamp 11 and also the lifetime of the stains that are present in the specimen S itself. The simultaneous image acquisition feature also reduces the possibility of image mis-alignment among the three images due to vibrations.
[0031] The three spectrally-selected images produced by the optical stage 3 are fed to the image capture camera 5 (FIG. 1). The image capture camera 5 comprises a CCD (Charge Coupled Device) camera which digitizes each of the three spectral images. The image capture camera 5 is described in greater detail below with reference to FIG. 5. The acquisition, digitization, storage and pre-processing of the three spectrally-selected images is controlled by an electronic control system 8 as shown in FIG. 4.
[0032] Reference is made to FIG. 4 which shows in block diagram the electronic control system 8 for the multi-spectral imaging system 1 . The electronic control system 8 comprises a control processor 33 , a pipeline processor 35 , a camera control subsystem 37 , and a strobe unit 39 . As shown in FIG. 4, the control processor 33 provides an interface to the mechanical subsystems 41 . The mechanical subsystems 41 comprise a slide loader 43 , a scanning table 45 and the voice-coil actuator 47 . Elements of the electronic control system 8 and the mechanical subsystems 41 are subjects of co-pending patent applications filed in the name of the common owner and referenced by International Patent Application No. CA96/00476 entitled Automatic Focus System, International Patent Application No. CA96/00475 entitled Spiral Scanner for Microscope Slides, and U.S. patent application Ser. No. 08/683,440 entitled Pipeline Processor for Medical/Biological Image Analysis.
[0033] Normal operation of the multi-spectral imaging system 1 is initiated by a call or request to the electronic control system 8 . The request is typically issued by a host/server 49 for image data and/or mathematical feature data which is derived from a captured image.
[0034] The request from the host/server is directed to the control processor 33 which is responsible for the overall control of the image acquisition systems comprising the camera 37 , strobe unit 39 and mechanical subsystems 41 . According to this aspect of the invention, the control processor 33 is suitably programmed to synchronize and integrate the operations of the mechanical subsystems 41 , camera control subsystem 37 and the pre-processing or pipeline processor 35 so as to comply and complete the request of the host/server.
[0035] In operation, the control processor 33 first determines the state of the slide loader 43 and scanning table 45 . (The operation of a preferred slide loader is described in co-pending PCT Patent Application No. CA96/00475 and U.S. Patent Application No. 60/001,220, and the operation of a preferred voice-coil actuator for an automatic focusing system is described in co-pending PCT Patent Application No. CA96/00476 and U.S. Patent Application No. 60/001,218.) The control processor 33 determines whether a slide carrying the specimen S is present in the scanning table 45 or whether a slide is being loaded or unloaded. The control processor 33 also receives signals with respect to the precise position of the slide on the scanning table 45 in relation to the optical axis of the system through a rotary encoding system (not shown). The control processor 33 then issues instructions to the voice-coil actuator 47 based on information provided by the pipeline processor 35 with respect into optimal focus position.
[0036] When the mechanical subsystems have been appropriately positioned, the control processor 33 instructs the camera subsystem 37 and the pipeline processor 35 . The camera subsystem 37 initiates capture of an image, and the captured image is then pre-processed by the pipeline processor 35 and the data generated is sent to the host/server 49 . For these functions, control preferably devolves to the local level of the control CPU in the pipeline processor 35 which is responsible for the image data requests and the pre-processing timing and synchronization.
[0037] The control CPU in the pipeline processor 35 determines the availability of memory, the timing conditions for the pipeline processor 35 and the status of the camera subsystem 37 . If the camera 37 and mechanical subsystems 41 are ready, the control CPU initiates a stroboscopic flash by means of a trigger command to the strobe unit 39 . Histogram processing in the pipeline processor 35 determines if the strobe unit 39 must adjust its intensity, and if necessary an analog signal is sent to the strobe unit 39 for such an adjustment before the flash is initiated. After the light pulse from the strobe lamp 11 is completed, the camera subsystem 37 converts the light signal into digital information.
[0038] According to this aspect, the camera subsystem 37 simultaneously digitizes the three images produced by the optical stage 3 (FIG. 2). After the digitization of the three spectrally-resolved images, all three digitized images are simultaneously transmitted from the camera subsystem 37 to the input stage of the pipeline processor 35 over three separate fibre-optic links (FIG. 5).
[0039] The pipeline processor 35 , under the control of the control processor 33 , performs the pre-processing steps required before classification procedures can be applied to the digitized images. The pre-processing operations include one of two types of segmentation procedures: (i) a multi-spectral segmentation operation, or (ii) a neural-network assisted multi-spectral segmentation operation. The multi-spectral segmentation process is described in co-pending PCT Application No. CA96/00477 and U.S. Patent Application No. 60/001,221, and the neural-network assisted multi-spectral segmentation process is described in copending PCT Application No. CA96/00619 and U.S. Patent Application No. 60/003,964. The pipeline processor is described in co-pending U.S. patent application Ser. No. 08/683,440 and U.S. Patent Application No. 60/001,219. The segmentation operation is followed by an extraction operation wherein a wide range of features from the segmented objects within the digitized images are extracted. The pipeline processor 35 is also responsible for image levelling routines, focus number calculations and histogram recalculations. The histogram calculations are used for proper light intensity control. When the segmentation and feature extraction operations are complete, the pipeline processor 35 sends the features to the host/server 49 along with the images (if requested by the host/server 49 ). The processed features are then. fed into a hierarchical classification system 51 . The principal function of the hierarchical classification system is to make decisions regarding the identity of the segmented objects, such as, identifying features or characteristics in the nuclei of cervical cells corresponding to medical prognosis.
[0040] As described above, a feature of the present invention is the simultaneous capture of three spectrally-resolved images of cellular matter and the subsequent digitization and processing of the image data. The image capture camera 5 is controlled by the camera control subsystem 37 (FIG. 4) as described above. The image capture camera 5 according to this aspect of the invention is shown in more detail in FIG. 5. The primary function of the image capture camera 5 is the digitization of the images for processing and analysis. Referring to FIG. 5, the image capture camera 5 comprises three image processing stages 101 , 102 , 103 , one for each spectral band. Each of the image processing stages 101 , 102 , 103 includes a Charge Coupled Device (CCD) array 105 , 107 , 109 . The first image processing stage 101 comprises the CCD array 105 , an analog-to-digital interface module 111 , and optic communication link 113 . The image processing stage 101 is controlled by signals generated by a control module 115 . Similarly, the second and third image processing stages 102 , 103 comprise respective analog-to-digital interface modules 117 , 119 , fibre-optic communication links 121 , 123 and control modules 125 , 27 . The Charge Coupled Device (CCD) arrays 105 , 107 , 109 are utilized for capturing three spectrally-resolved images. Charge Coupled Devices are preferred because they are stable, solid-state elements which have a linear response to visible light over a wide spectral range. The CCD arrays 105 , 107 , 109 provides a high rate of image capture in a digital format that is particularly suited to computer processing and display. Advantageously, the CCD arrays 105 , 107 , 109 permit the imaging system 1 to avoid complications associated with analogue cameras such as baseline drift, re-sampling errors and analogue noise. The CCD arrays 105 , 107 , 109 take the form of area (rather than linear) scan arrays of 512 vertical by 768 horizontal picture elements (“pixels”). By employing accurate timing of the scan lines, the images drawn from the CCD arrays utilize only 512 of the 768 pixels available in the horizontal dimension. This allows a shift of image position by up to 50% without the need to resort to mechanical adjustments.
[0041] According to the invention, the images of the cervical cells are simultaneously examined by three narrow (10 nm) interference band-pass filters 27 , 29 , 31 (FIG. 2). This allows a maximization of the image contrast between the nucleus and the cytoplasm in the specimen S and between the cytoplasm and the background.
[0042] The CCD arrays. 105 , 107 , 109 used in the image capture camera 5 preferably comprise the CCD array manufactured by Kodak under model number KAF-0400. The KAF-0400 model CCD array is a full-frame image sensor, i.e. the CCD device captures and transfers an entire video frame rather than using alternating image “fields” composed of odd and even rows (known in the art as the interline transfer technique). The use of a full-frame sensor is preferred because it simplifies the electronics while maintaining image resolution. The maximum data rate for the KAF0400 model CCD array device is 20 MHz which allows a theoretical image capture limit of 40 frames/sec. The picture elements of the CCD array are square (9 microns×9 microns). This feature eliminates the need for the aspect-ratio corrections as required in television receivers for example. In addition, the CCD array provides a 100% fill factor for the pixels. This means that a negligible amount of light is lost to the depletion regions that confine the photo-generated electrons to each individual pixel. The KAF-0400 CCD array does not have an electronic “shutter” which allows it to clear out and reset all the pixels between capturing and transferring images. However, as the illumination system consists of an arc-discharge strobe lamp 11 the integration of stray light between images does not pose a problem. In another aspect, each “line” of the CCD array 105 , 107 , 109 has a number of “black” reference level pixels that are completely shielded from light. The “black” pixels are measured to establish a baseline for the CCD array on a line-by-line basis. This allows an immediate adjustment for drifts in sensitivity due to temperature or electrical fluctuations in the CCD array.
[0043] Referring to FIG. 5, each CCD array 105 , 107 , 109 is coupled to the respective control module comprising a Field-Programmable Gate-Array (FPGA) 115 , 125 , 127 . The first FPGA 115 is also coupled to a command register 129 . The command register 129 comprises a shift register which receives instructions from an external source, in this case, the command register 129 receives control commands from the control CPU in the pipeline processor 35 . The commands issued by the pipeline processor 35 instruct the FPGA 115 to “take a picture”. The other two FPGA's 125 , 127 are coupled to the first FPGA 115 through a “daisy-chain” and also receive the command. The FPGA's 125 , 127 , 115 comprise digital logic circuits and are configured to issue control signals in response to commands received from the control CPU in the pipeline processor 35 for controlling the operation of the respective image processing/capture stage 101 , 102 , 103 . In particular, each FPGA 115 , 125 , 127 is programmed to synchronize the respective CCD array 105 , 107 , 109 and initiate the timing procedures for capturing and digitizing each of the spectrally-resolved images. In operation, each FPGA 115 , 125 , 127 synchronizes the respective CCD array 105 , 107 , 109 and initiates the timing procedures. The first FPGA 115 then sends a signal via the interface register 129 and pipeline processor 35 to the strobe unit 39 to initiate a flash and then the capture of the three spectrally-resolved images. After the flash is complete, the transfer and pre-processing of image data from the three CCD arrays 105 , 107 , 109 is commenced simultaneously.
[0044] Referring to FIG. 5, the contents of each pixel in the CCD array 105 , 107 , 109 are shifted out one-by-one to the respective analog-to-digital interface module 111 , 117 , 119 . The analog-to-digital interface modules 111 , 117 , 119 are preferably implemented using the single-channel analog-to-digital signal interface available from Philips Semiconductors under model number TDA-8786. The TDA-8786 analog-to-digital interface features a Correlated Double Sampling (CDS) circuit 131 , automatic gain control (AGC) 133 , a 10-bit analog-to-digital converter 135 , a reference voltage regulator 137 , and is fully programmable via a serial interface, as will be understood by one skilled in the art.
[0045] As shown in FIG. 5, the analog-to-digital interface modules accept and measure the electronic charge from the CCD camera arrays 105 , 107 , 109 using the internal correlated double sampling circuitry 131 . The output voltage is amplified within the analog-to-digital interface through an internal voltage-controlled voltage amplifier 133 . The gain of this voltage controlled voltage amplifier 133 is controlled by an on-chip digital-to-analog converter (not shown) that receives instructions via a serial interface coupled to the FPGA 115 , 125 , 127 . This arrangement allows the FPGA 115 , 125 , 127 to electronically adjust the gain of the video signal produced by the respective CCD array 105 , 107 , 109 .
[0046] The “optical black clamp” in the analog-to-digital interface 111 , 117 , 119 is timed to sense the output of the first “black” pixels mentioned above. The voltage values extracted from the “black” pixels are used to off-set the sample-and-hold circuit so as to compensate for drifts in the response of the CCD array 105 , 107 , 109 in a line-by-line fashion.
[0047] The output signals from the CCD arrays 105 , 107 , 109 , now converted to voltage values, are sent to the on-board analog-to-digital converter 135 . The analog-to-digital converter 135 is capable of 10 bits accuracy, but as will be understood by one skilled in the art the usable output will be limited by the bandwidth of the analog video signal received from the video differencing amplifiers 133 contained within the analog-to-digital signal interfaces 111 , 117 , 119 .
[0048] The digital video signal derived from the output for each CCD array 105 , 107 , 109 is transmitted via the respective fibre-optic link 113 , 121 , 123 to the computational sections of the pipeline processor 35 .
[0049] As described above, a feature of the multi-spectral imaging system 1 is the capability to simultaneously capture the same scene in each of three narrow optical bands, 530 nm, 577 nm and 630 nm.
[0050] The use of the spectrally-resolved images according to the present invention as described above permits a more refined and accurate measure of the relevant biological characteristics of the segmented objects such as DNA quantification, etc. In this aspect, the multi-spectral imaging technique both concentrates attention on the relevant biological measures and greatly multiplies the number of features available for the classification stage. This is an important advantage because it is usually not known at the outset which, if any, features will be of value to classification. Additional applications and techniques for feature extraction with these spectrally-resolved images may be found in the co-pending PCT Patent Application No. CA96/00478 for a Window Texture Extraction method. Another advantage of the multi-spectral imaging system is the reduction in the sensitivity to stain variations. The use of these three narrow optical bands reduces the sensitivity of the classification to variations in the quality and intensity of the Papanicolaou stain. The application of this stain protocol is very much site-dependent, and variations are typically only noticed when they begin to interfere with the human interpretation of the Pap tests. If an automated analysis system is to be commercially-viable then it must not be over-sensitive to these stain variations. The use of the three narrow optical bands allows the contraction of a set of stain-invariant, or at the very least, less stain-sensitive features based on the ratios of the three optical bands. This improves the versatility of the classification system and advantageously its commercial value.
[0051] The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the presently discussed embodiments are considered to be illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than 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 multi-spectral image system and method for cytology. The multi-spectral imaging system comprises an optical stage, an image capture camera, and a controller. The optical stage includes a light source for illuminating the cytological specimen and optical means for producing images of the illuminated specimen in a number of spectral bands. The image capture camera includes means for simultaneously capturing the spectral images and generating electrical signals corresponding to the captured images. The controller controls the operation of the image capture camera and the light source and includes means for converting the electrical signals into a data form suitable for further processing. The multi-spectral imaging system is particularly suited for specimens prepared in the form of thin-layers or monolayers. The image data produced by the relevant state of the specimen and also permits the use of human-expert review for confirmation.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Patent Application No. 10-2014-0179064, filed on Dec. 12, 2014, the disclosure of which is hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a forming apparatus for manufacturing a curved panel by shaping a flat metal sheet to be curved, and more particularly, to a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel, wherein both ends of a sheet are stretched to match to the shape of a curved panel by using a plurality of clamps each individually controlled.
2. Description of the Related Art
Generally, curved metal panels in various shapes are used for the hull of a ship, the fuselage of an airplane, the exterior panel of a building.
When a press die is used to mass-produce a curved panel in a typical shape which is a fixed curve shape, like a globular shape or an arc shape, it increases the improvement of workability and productivity.
However, in the case of a curved panel in an atypical shape having multi-dimensional curve shapes, it is very difficult to manufacture it using a press die. Further, when the demand for a particular curved panel is low, a production cost is high due to the die expense.
Patent document 1, below, discloses an apparatus for forming components for an airplane. This apparatus comprises: a top punching member positioned to move vertically by a hydraulic and/or pneumatic device; a bottom die having a processing surface with a number of flat sections, a number of protruding sections and a number of groove sections on its upper side, wherein a workpiece to be processed is positioned on the processing surface; and a number of pressing blocks for a secondary process, positioned on the workpiece so as to be positioned at the groove sections of the bottom die.
To form curved panels for an airplane by using a particular die, such as the apparatus for forming components for an airplane of patent document 1, many dies are needed to form the curved panels in various shapes. Accordingly, the apparatus for forming a curved panel like patent document 1 is not proper to form curved panels in a small quantity batch production.
Patent document 2, below, discloses a multipoint variable press-type apparatus for forming a curved panel. This apparatus comprises: a base with a forward and backward guide rail and a right and left guide rail positioned in the horizontal direction; a bottom punch module positioned on the base, with a number of punches to hold and support a curved panel; a top punch module with a number of punches vertically movable by a hydraulic system; a first supporting punch module positioned at one side of the top punch module, with a number of punches vertically movable by a hydraulic system; and second supporting punch modules positioned at right and left sides of the bottom punch module, with a number of punches vertically movable by a hydraulic system.
Patent document 3, below, discloses a multipoint stretch-type apparatus for forming a shape steel with a curved surface. This apparatus comprises: a stretching section applying tension in the state that both ends of the steel to be shaped are supported by clamps; a formation molding section applying a shear force to the steel under the stretching section; and a controlling section forming a curved surface of curvature being set at a yield point of the steel, by connectively controlling the stretching section and the formation molding section.
Patent document 4, below, discloses a method for manufacturing a panel having a multi-dimensionally curved surface. In this patent document, top and bottom dies are variably symmetrically set as a specific shape of a particular multi-dimensionally curved surface, using a number of multipoint molding pins. In the state that a metal sheet to form the multi-dimensionally curved surface is secured on the top surface of the bottom die forming the specific shape of the multi-dimensionally curved surface, a number of stretch forming apparatuses pull both ends of the metal sheet with a force exceeding a plastic point and a yield point of the metal sheet, to primarily form the multi-dimensionally curved surface in the same shape formed on the top surface of the bottom die. Then, the top die moves down to press the metal sheet stretched in the shape formed on the top die as the shape is.
All techniques disclosed in patent documents 2 through 4 are to efficiently form an atypical shape steel or atypically curved panel in small quantity, by using variable dies.
Patent document 5, below, discloses an elongating, forming and processing machine and method and patent document 6 discloses an apparatus and method for forming panels into complex curved shapes.
The apparatus disclosed in patent document 6, below, comprises a variable displacement tension bar including a number of pull tabs and enabling each pull tab to be independently controlled.
RELATED ART DOCUMENT
Patent Document
(Patent Document 1) Korean Patent Published Application No. 10-2006-0104167 (laid-open on Oct. 9, 2006)
(Patent Document 2) Korean U.M. Published Application No. 20-2011-0006710 (laid-open on Jul. 6, 2011)
(Patent Document 3) Korean Patent Publication No. 10-1301714 (published on Aug. 30, 2013)
(Patent Document 4) Korean Patent Publication No. 10-1030226 (published on Apr. 13, 2011)
(Patent Document 5) Korean Patent Published Application No. 10-2008-0085917 (laid-open on Sep. 24, 2008)
(Patent Document 6) U.S. Pat. No. 6,272,897 (published on Aug. 14, 2001)
However, since the multipoint variable press-type apparatus for forming a curved panel disclosed in patent document 2 simply presses a material sheet positioned on a bottom die, using a top die, formability is less than the press equipment using the particular die like patent document 1. Therefore, a post-process is required and it is difficult to form a curved panel having a complicated shape.
Further, the multipoint stretch-type apparatus for forming a shape steel having a curved surface in patent document 3 is to curve the shape steel in a pole or tube shape. Therefore, it cannot form a curved panel being atypically curved.
Further, in the multipoint stretch forming apparatus disclosed in relation to the method for manufacturing a panel having a multi-dimensionally curved surface, each part of both ends of a sheet is stretched by uniform pressure. Therefore, precise formation is difficult and the loss factor of material is high.
Further, in the apparatuses for forming panels into complex curved shapes disclosed in patent documents 5 and 6, it is impossible to adjust the distance between the stretching units, based on the size of a curved panel to be formed or the size of a punch module.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to solve the above problems and to provide a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel, to more precisely and promptly form an atypical curved panel by stretching each part of both ends of an original panel by using each different pressure based on the shape of a curve to be formed.
It is another object of the present invention to provide a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel, to lower the loss factor of material.
It is another object of the present invention to provide a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel, to adjust the distance between stretching units based on the size of a curved panel or the size of a punch module.
In accordance with an embodiment of the present invention, there is provided a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel, comprising: a supporting frame to support a bottom punch module, stretching units and a top punch module; the bottom punch module positioned in the center at a lower position of the supporting frame; a plurality of the stretching units positioned to be seriately arranged at both sides at the lower position of the supporting frame in forward and backward directions; the top punch module positioned in the center at an upper position of the supporting frame, to be vertically movable; a control unit to control the operation of the bottom punch module, the stretching units and the top punch module; a fixed casing fixedly positioned at one side at the lower position of the supporting frame, to support the stretching units positioned at the one side of the supporting frame; a movable casing positioned at the other side at the lower position of the supporting frame, to be movable in right and left directions and to support the stretching units positioned at the other side of the supporting frame; the moving cylinder positioned at the supporting frame between the fixed casing and the movable casing, to move the movable casing in the right and left directions; and a guide positioned between the fixed casing and the movable casing, to guide the movement of the movable casing in the right and left directions, wherein each of the stretching units is independently and individually controlled by the control unit so that each part of an original panel sheet C is stretched by a different pressure in accordance with a curve shape, and the moving cylinder is operated to adjust the distance between the right and left stretching units in accordance with the size of the bottom punch module and top punch module and the size of a curved panel C to be formed.
Preferably, the supporting frame may comprise: a horizontal supporting element to support the bottom punch module and the stretching units; and a vertical supporting element positioned in the middle of the horizontal supporting element, to support the vertical movement of the top punch module.
Preferably, the bottom punch module may comprise: a support block supported to the supporting frame; and a number of punches seriately arranged in forward and backward and right and left directions on the support block, wherein each of the punches of the bottom punch module is positioned on the support block so as to be movable vertically and is independently moved vertically by a lift actuator operated by a control signal of the control unit.
Preferably, each of the stretching units may comprise: a clamp including a receiving groove positioned inside and a clamping cylinder positioned above; a connecting member to connect the clamp and a stretching cylinder; and the stretching cylinder including a body connected to the supporting frame and an operating plunger connected to the connecting member by a hinge, to stretch the original panel sheet A clamped to the clamp by the control signal of the control unit.
Preferably, the top punch module may comprise: a support block supported to the supporting frame, to be movable vertically; a number of punches seriately arranged in forward and backward and right and left directions under the support block; and a lift cylinder positioned at the supporting frame and connected to the support block, wherein each of the punches of the top punch module is positioned on the support block so as to be movable vertically and is independently moved vertically by a lift actuator operated by a control signal of the control unit.
Preferably, the guide may comprise: a fixed sleeve fixedly positioned at the fixed casing; a movable sleeve fixedly positioned at the movable casing; and a guide shaft with one end fixed to the fixed sleeve and the other end passing through the movable sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail the preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a front view of the major parts of a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to an embodiment of the present invention;
FIG. 2 is an enlarged front view of the major parts of a stretching unit of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention;
FIG. 3 is a plan view of the major parts of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention;
FIG. 4 is a side view of the major parts of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention;
FIG. 5 is a perspective view of an atypically curved panel formed by the major parts of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention; and
FIGS. 6A and 6B are front views of major parts showing a replacement of a punch module in the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention.
DESCRIPTION OF NUMBERS FOR CONSTITUENTS IN DRAWINGS
100 : multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel
110 : supporting frame
120 : bottom punch module
130 : stretching unit
140 : top punch module
150 : control unit
160 : fixed casing
170 : movable casing
180 : moving cylinder
190 : guide
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown so that those of ordinary skill in the art can easily carry out the present invention.
It should be understood that, the terms of directional natures, “upward”, “downward”, “forward”, “backward”, etc., are defined based on the states illustrated in the drawings.
FIG. 1 is a front view of the major parts of a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to an embodiment of the present invention, and FIG. 2 is an enlarged front view of the major parts of a stretching unit of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention.
FIG. 3 is a plan view of the major parts of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, and FIG. 4 is a side view of the major parts of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention.
A multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to a preferred embodiment of the present invention comprises: a supporting frame 110 , a bottom punch module 120 , a stretching unit 130 , an top punch module 140 , a control unit 150 , a fixed casing 160 , an movable casing 170 , a moving cylinder 180 and a guide 190 .
The supporting frame 110 supports the bottom punch module 120 , the stretching unit 130 and the top punch module 140 .
The supporting frame 110 includes a horizontal supporting element 111 to support the bottom punch module 120 and the stretching unit 130 , and a vertical supporting element 112 positioned in the middle of the horizontal supporting element 111 , supporting the vertical movement of the top punch module 140 .
In the bottom punch module 120 , an original panel sheet A is to be formed into a curved panel C. The bottom punch module 120 is positioned at the middle on the horizontal supporting element 111 of the supporting frame 110 .
The bottom punch module 120 includes a support block 121 supported by the supporting frame 110 , and a number of punches 122 seriately arranged on the support block 121 in the forward and backward and right and left directions.
Each punch 122 of the bottom punch module 120 is positioned at the support block 121 to be vertically movable and independently moves vertically by an lift actuator (not shown) operated through a control signal of the control unit 150 .
The stretching unit 130 is to stretch both ends of the original panel sheet A positioned on the bottom punch module 120 by clamping. The stretching unit 130 is positioned at both sides on the vertical supporting element 111 of the supporting frame 110 .
The stretching unit 130 includes a clamp 131 , a connecting member 132 and a stretching cylinder 133 .
The clamp 131 to clamp the original panel sheet A includes a receiving groove 131 a positioned inside and a clamping cylinder 131 b positioned above.
The connecting member 131 is to connect the clamp 131 and the stretching cylinder 133 .
The stretching cylinder 133 is to stretch the original panel sheet A clamped by the clamp 131 based on a control signal of the control unit 150 . A body of the stretching cylinder 133 is connected to the supporting frame 110 by a hinge and an operating plunger is connected to the connecting member 132 by a hinge.
The stretching cylinder 133 includes a first stretching cylinder 133 a positioned at a titling angle which is close to the horizontal, a second stretching cylinder 133 b positioned at a tilting angle which is close to the vertical, and a third stretching cylinder 133 c positioned at a tilting angle which is the middle between the tilting angle of the first stretching cylinder 133 a and the tilting angle of the second stretching cylinder 133 b.
In the multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, a plurality of the stretching units 130 are positioned to be seriately arranged in the forward and backward directions and the stretching cylinder 133 of each stretching unit 130 is independently and individually controlled.
That is, in the multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, the plurality of the stretching units 130 stretch the original panel sheet A by using different stretching pressure, in accordance with the shape of a curved panel C to be formed.
The top punch module 140 is positioned at the vertical supporting element 112 of the supporting frame 110 , to be vertically movable.
The top punch module 140 includes a support block 141 supported by the supporting frame 110 to be vertically movably; a number of punches 142 seriately arranged under the support block 141 in the forward and backward right and left directions; and a lift cylinder 143 positioned on the vertical supporting element 112 of the supporting frame 110 and connected to the support block 141 .
Each punch 142 of the top punch module 140 is positioned at the support block 141 to be vertically movable and independently moves vertically by a lift actuator (not shown) operated through the control signal of the control unit 150 .
The control unit 150 controls the operations of the lift actuator of each of the top punch module 120 and the bottom punch module 140 , the stretching cylinder 133 of the stretching unit 130 , the lift cylinder 143 of the top punch module 140 and the moving cylinder 180 . The control unit 150 is positioned in front of the vertical supporting element 112 of the supporting frame 110 .
The control unit 150 adjusts the positions where the punches 122 , 142 of the bottom punch module 120 and top punch module 140 move vertically, based on the information of the curved panel being input, making the shape of the curved panel to be formed by the top surface of the bottom punch module 120 and the bottom surface of the top punch module 140 .
The fixed casing 160 is open at a top and left side. The fixed casing 160 is to support each stretching unit 130 stretching a right side of the original panel sheet A.
The fixed casing 160 is fixedly positioned on the left side of the horizontal supporting element 111 of the supporting frame 110 .
The movable casing 170 is open at a top and right side. The movable casing 170 is to support each stretching unit 130 stretching a left side of the original panel sheet A.
The movable casing 170 is positioned on the right side of the horizontal supporting element 111 of the supporting frame 110 , to be movable in the right and left directions.
The moving cylinder 180 is to move the movable casing 170 and the stretching units 130 supported by the movable casing 170 . The moving cylinder 180 is positioned on the horizontal supporting element 111 of the supporting frame 110 between the fixed casing 160 and the movable case 170 .
A body of the moving cylinder 180 is fixedly positioned on the horizontal supporting element 111 of the supporting frame 110 and an operating plunger is connected to the right side of the movable casing 170 .
Accordingly, when the operating plunger of the moving cylinder 180 is operated to be received toward the body, the movable casing 170 connected to the operating plunger and each stretching unit 130 supported by the movable casing 170 move towards the fixed casing 160 , so that the distance between the fixed casing 160 and the movable casing 170 and the distance between the right and left stretching units 130 are shortened.
On the contrary to this, when the operating plunger of the moving cylinder 180 is operated to be withdrawn from the body, the movable casing 170 and each stretching unit 130 supported by the movable casing 170 move in the opposite directions, so that the distance between the fixed casing 160 and the movable casing 170 and the distance between the right and left stretching units 130 are increased.
In the multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, a pair of the moving cylinder 180 is positioned in the front and back on the horizontal supporting element 111 of the supporting frame 110 between the fixed casing 160 and the movable casing 170 . However, the number and shape of the moving cylinders 180 to be installed may be modified within the range to be predicable.
The guide 190 is to guide the right and left movement of the movable casing 170 and the stretching unit 130 supported by the movable casing 170 . The guide 190 is positioned between the fixed casing 160 and the movable casing 170 .
The guide 190 includes a fixed sleeve 191 fixedly positioned at the fixed casing 160 ; a movable sleeve 192 fixedly positioned at the movable casing 170 ; and a guide shaft 193 with one end fixed to the fixed sleeve 191 and the other end passing through the movable sleeve 192 .
In the drawings, reference mark R not explained indicates a loading and unloading robot.
In the multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, after a primarily formation is performed by stretching the original panel sheet A positioned on the bottom punch module 120 by using the plurality of the stretching units 130 , a curved panel which is primarily formed is pressurized by using the top punch module 140 , to form the curve plate C.
Prior to the process of forming the curved panel, the control unit 150 adjusts each of the punches 122 , 142 to the shape of the curved panel C to be formed, by operating the lift actuators of the bottom punch module 120 and top punch module 140 , based on the information of the curved panel being previously input.
Further, in the process of stretching the original panel sheet A positioned on the bottom punch module 120 , the control unit 150 independently and individually controls the operation of the stretching cylinder 133 of each stretching unit 130 , according to the shape of the curved panel C, so that the original panel sheet A is formed to the curved panel C more precisely and promptly.
FIG. 5 is a perspective view of an atypical curved panel formed by the major parts of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention.
The atypical curved panel C shown in FIG. 5 is curved in the right and left directions and the upward and downward directions. In the case of forming the atypical curved panel C including the curved parts curved downward in the forward and backward directions as shown in FIG. 5 , when the original panel sheet A is stretched, the stretching unit 130 clamping the downwardly curved part, among the plurality of the stretching units 130 , is controlled to put the tensile force which is relatively higher than the stretching unit(s) 130 clamping the other part(s).
The outer part of the curved panel C finishing the above stretching formation and the pressing formation by the top punch module 140 is cut based on the dimensions being set, completing the final curved panel. The finished curved panel C is checked for accuracy through a measuring process and then shipped.
In the multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, the distance between the right and left stretching units 130 is properly adjusted, based on the size of the bottom punch module 120 and top punch module 140 and the size of the curved panel C to be formed.
That is, in the multipoint stretch forming apparatus 100 enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention, the movable casing 170 and the stretching unit 130 at one side supported by the movable casing 170 are movable in the right and left directions.
Therefore, since the distance between the right and left stretching units 130 is variably set, the curved panel C in a different size is precisely formed by replacing the bottom punch module 120 and top punch module 140 in a different size.
FIGS. 6A and 6B are front views of major parts showing a replacement of a punch module of the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the embodiment of the present invention.
In the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel according to the present invention, each part of the original panel sheet is efficiently stretched, based on the curve shape by a plurality of the stretching units which are seriately arranged in forward and backward directions and independently and individually controlled, thereby greatly improving the degree of formation precision and the productivity.
Further, according to the multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel of the present invention, the loss factor of the material is remarkably lowered, thereby increasing the reduction of production cost.
Further, it is possible to precisely set the distance between the left and right stretching units based on the right and left lengths of the punching modules and curved panel to be formed and it is possible to freely replace the punching modules in various sizes for use.
The invention has been described using preferred exemplary embodiments. However, it is to be understood that the scope of the invention is not limited to the disclosed embodiments. On the contrary, the scope of the invention is intended to include various modifications and alternative arrangements within the capabilities of persons skilled in the art using presently known or future technologies and equivalents. The scope of the claims, therefore, should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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Provided is a multipoint stretch forming apparatus enabling individual clamping control for manufacturing a curved panel, wherein a plurality of stretching units are positioned at both sides at a lower position of a supporting frame in forward and backward directions, and each of the stretching units is independently and individually controlled. Further, since the distance between the right and left stretching units is adjustable in accordance with the size of punch modules and the size of a curved panel to be formed, the precision formation of both wide and narrow curved panels/shapes is possible. Through this technical constitution, an atypical curved panel is formed more efficiently and the loss of panel material is remarkably reduced.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention is of a protective shield for a vessel having an engine with a transmission means having a portion extending exteriorly of the vessel, the protective shield being adapted to be positioned about .the interconnection of the out drive and the transmission means.
SUMMARY OF THE INVENTION
In the past, there has long been a problem of theft of out drives of vessels equipped with an inboard engine and a transmission means with a portion extending exteriorly of the vessel. Conventionally, the exteriorly extending portion of the transmission means includes an outboard bell housing. An out drive is secured by bolts to the bell housing. All that is required to quickly "snatch" an out drive is the removal of six bolts which conventionally fasten an out drive to the bell housing of the boat. Without protection, an out drive can be removed from a bell housing by simply removing those six bolts which requires in the order of about three to five minutes. Since out drives are relatively expensive, replacement cost being in the range of $2,000.00 to $3,000.00, it is important that the number of this type of quick "snatch" theft be reduced.
It is estimated that there are currently 50,000 thefts annually; and the attendant expense is apparent testifying to the need for such a device.
This invention is of a shield which protectively prohibits access to the bolts. The protective shield of the instant invention is adapted to be quickly and readily installed to protectively shield access to the bolts which secure an out drive to a bell housing, thereby deterring theft of the out drive.
The art is replete with numerous efforts by others to resolve this problem such as is exemplified by the patent to Brushaber, U.S. Pat. No. 4,736,603 which attempts to solve the problem by providing locks on each of the respective exteriorly accessible six bolts. Another representative effort to solve the problem is found in U.S. Pat. No. 4,502,306, which teaches a locking device for the out drive of a boat which completely enshrouds the stern of a vessel. Another representative patent is U.S. Pat. No. 4,325,701, dated Apr. 20, 1982 and issued to James K. Peters, II for a protective device which is in the form of a shield which includes an upper portion which cooperates with a replacement part for an engine. In this invention, the upper portion of the out drive, or its cap, must be removed, and replaced by a different cap having a protrusion with an eye to accommodate a padlock.
The present invention is of a device which is not invasive of the existing outboard structure but which, rather, is positioned about it, shielding the bolts so that access cannot be obtained to them without substantial difficulty thereby deterring a quick "snatch" of an out drive. Thus, a person who has his boat in a side yard or driveway, is not in fear that the out drive can be snatched readily by a thief.
This protective shield is particularly designed to be used in connection with the Alpha One Merc Cruiser out drive manufactured by Merc Cruiser Marine Company of Wisconsin. This popular out drive is characterized by a gear housing which includes six vulnerable bolts which are easily accessible. The six bolts attach the out drive to the bell housing of a fitting connected to the transom of a boat. An example of this common out drive connection is seen for example in U.S. Pat. No. 4,325,701 in FIG. 1. For purposes of reducing the amount of pages of this application, the Merc Cruiser out drive will not be described in detail. Suffice it to say that this invention shields the location of the six vulnerable bolts as described more fully hereinafter.
With further reference to U.S. Pat. No. 4,325,701, it provides a shield for the six bolts; however, the cap of the gear housing of the drive must be replaced in order to provide a different cap according to the patent, which has an eye structure to accommodate a padlock. It is not desirable that an out drive be modified in such a way because it violates the warranty of the manufacturer. This invention is of a device which attaches in a non-intrusive attachment manner about a Merc Cruiser out drive Alpha One Series. This invention does not require foreign parts to replace existing structure or parts of a standard Merc Cruiser out drive of the Alpha One Series. Rather, this invention, when installed, provides a protective shield, which is preferably of steel, and which can be installed without the need of tools which presents what appears to be a massive defense to deter theft of an out drive and is effective to thwart a "quick snatch" thief.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a side elevation view of the protective shield installed about an out drive and which is shown in dashed lines.
FIG. 2 is a side elevation view of the protective shield; the opposite side elevation view is a mirror image of this view.
FIG. 3 is a rear elevation view of the shield, that is, looking from the stern forward toward the vessel when installed.
FIG. 4 is a front elevation view, that is, looking at the protective shield from inside the vessel aft.
FIG. 5 is a top plan view of the protective shield.
FIG. 6 is a top plan view of a locking pin used in connection with the shield for securing it about the out drive, as described more fully hereinafter.
FIG. 7 is a side elevation view illustrating the protective pin with a padlock secured to it.
Like reference numerals refer to like parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before describing the protective shield 32 in detail, it is pointed out, on reference to FIG. 1, that the out drive there indicated has been elevated, that is to say it is not in the operative or down position. Only when in the elevated or up position indicated in FIG. 1, it is important to note that there is a space 30 which is created and which space is utilized for passage of a locking pin 34 which connects the shield in protective relation about the out drive housing denying access to the vulnerable bolts, such as 18, 20 and 22.
Referring to the drawings, and particularly to FIG. 1, the numeral 12 indicates, generally, the transom of a boat to which there is mounted a fitting 14 which includes a bell housing 16. Conventionally, an out drive generally designated by the numeral 17 is secured to the bell housing by means of six bolts which are designated by the numerals 18, 20, and 22. On the opposite side not shown in FIG. 1 there are similarly three bolts which also secure the out drive to the bell housing.
As will be appreciated by those in the field, in FIG. 1, the out drive is shown in an elevated or raised position. The out drive is raised by operation of pistons, one of which is designated by the numeral 19, there being a companionate piston on the opposite side of the out drive. The out drive may be moved to the in use or operating position by swinging it in the direction of the arrowed line 21, using the piston drive. When the out drive is in the lowered position, not shown, there is no space 30; however, when the out drive is in the raised attitude as shown in FIG. 1, there is a space generally designated by the numeral 30. This space is of significance in connection with the protective shield and its installation now to be described.
The protective shield, generally designated by the numeral 32, is secured by a pin 34 and padlock, not shown in FIG. 1, protectively about the connecting bolts of the out drive in a manner now to be described.
Referring first to the protective shield, as seen in FIGS. 2-5, it is seen that it includes a rear wall 37 and opposite side walls 39 and 41 which are in spaced relation with respect to one another, the wall 37 being sized and structured to be disposed in close proximity to the aft facing surface of the out drive housing. It will be seen in FIG. 1 that the walls 39 and 41 are of sufficient height at the rear wall 37 to cover at least two of the anchoring bolts on each side of the connection of the out drive to the bell housing, which are bolts 20 and 22 in FIG. 1 and the opposite side bolts, not shown. Preferably, the side walls 39 and 41 are disposed closely about the uppermost bolt 18 also, so as to interfere with ready manipulation of removal.
Thus, in the preferred embodiment of the shield, the top edge of the side walls, edges 42 and 44, see FIG. 5, converge from the rear wall 37 downwardly to the bottom edge of each of the side walls, the bottom edges being designated by the numerals 51 and 53, see FIG. 4. In the preferred embodiment, as seen best in FIGS. 3 and 4, the lower portion of the side walls is reversely bent in a U-shaped formation providing upwardly extending inner legs 55 and 57 for a purpose to be described. It is pointed out that the width of the drive at this lower location is somewhat narrower than in the upper zone.
For the purpose of securing the protective shield in covering relation of the out drive, as seen in FIG. 1, a locking pin, shown in FIGS. 6 and 7 and designated by the numeral 34, is provided. The locking pin is sized and configured for passage through the space 30 and through the aligned holes in the lower portion of the side walls 39 and 41 and legs 55 and 57 adjacent the lower edges, generally the holes are designated by the numerals 62 and 64. The locking pin is of steel, as is the shield proper, in the preferred embodiment.
Referring more particularly to FIGS. 6 and 7, in one preferred embodiment, the pin 34 has a central portion 70 which is of reduced diameter and through the center of which there is provided a hole 72. Once the pin is inserted so as to pass through the space 30 and the holes 62 and 64, it is of a length such that it extends outwardly from each hole. A padlock designated by the numeral 75 is secured to keep the pin in position, the locked position described. It will be appreciated that the length of the pin is about twice the length of the span between the inside confronting surfaces about the holes of the respective side walls so that upon shifting of the pin in one direction or the other, it cannot not be removed from the holes because the padlock will come in abutting contact with the shield walls serving as a stop against this shifting movement of removal. Also, because of the location of the padlock in the space 30 which is rather confined, the lock is substantially hidden and when discovered, is not readily accessible for tools which might be used in an attempt to break the lock and remove the pin and shield.
In operation, when the boat is not in use, the out drive is elevated to the position in FIG. 1, causing the space 30 to appear. At this point, the shield is fitted over the out drive housing in covering relation preferably of at least four of the bolts securing the out drive to the bell housing, as indicated in FIG. 1. It will be seen that the upper edge of the shield is closely adjacent the uppermost exposed bolts so that they cannot be easily manipulated. Thereafter, the pin 34 is inserted through the holes 62 and 64 of the side walls 39 and 41 and lower legs 55 and 57 and through the confined space 30 created which appears when the out drive is raised. Thereafter, a padlock 75 is secured through the hole 72 in the locking pin. It will be appreciated that various modifications can be made of the pin structure itself. For example, a pair of oppositely extending sleeves might be provided on the pin, which is not shown but which it is apparent would prevent shifting and accommodate a pin of reduced length.
In a preferred embodiment, the side walls are spaced so as to define an outer dimension of about 6-1/2" and a distance between the leg surfaces is about 5-1/2". The overall height of the shield is about 12". Preferably, the locking pin is of steel rod of 1" diameter and the walls are 1/4" thick steel, it being noted that the legs 55 and 57 provide reinforcement.
While this invention has been shown and described in a practical and preferred embodiment, it is recognized that departures may be made within the spirit and scope of this invention which, therefore, should not be limited except as set forth in the claims which follow and within the doctrine of equivalents.
Now that the invention has been described,
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The invention relates to a protective shield for a vessel having an engine with a transmission portion extending exteriorly of the vessel. The protective shield is designed to be positioned about the interconnection of the out drive and the transmission portion when the out drive is in an elevated position and effective to block access to the fasteners which secure the out drive to the transmission. The protective shield has a pair of spaced side walls converging downwardly and away from a rear wall and each side wall has a hole therethrough to accept a locking pin. The shield deters removal of the out drive by unauthorized persons.
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FIELD OF THE INVENTION
The invention relates to the field of electrochemical reactors such as fuel cells and storage batteries and more particularly the field of electrodes used in such cells. It relates more specifically to the deposition of catalyst particles constituting the active part of the electrodes of fuel cells, of the PEMFC (Proton Exchange Membrane Fuel Cell) type.
According to the invention, this deposition is carried out by the DLI-MOCVD (Direct Liquid Metal Organic Chemical Vapour Deposition) process, making it possible to immobilise the catalyst particles directly on the electron conductor support components (GDL for Gas Diffusion Layer), and thereby to optimise the use of the immobilised catalyst load and to favour the organisation of the catalyst layer for electrocatalysis.
This method, which serves to control the load of immobilised catalyst particles and the morphology of the particles, can be industrialised easily and developed for mass production of electrodes for fuel cells because it is compatible with continuous deposition processes.
The electrodes thereby obtained have a unique structure, the catalyst being in the form of nanoparticles directly dispersed on the diffusion layer.
Broadly speaking, the invention relates to any electrode material used for fuel cell and battery systems in power generation.
BACKGROUND OF THE INVENTION
The material constituting the electrodes of a fuel cell operating at low temperature (PEMFC, DMFC, alkaline solid membrane battery) is produced on a carbon support based on fabric, paper or felt, which plays the role of support for the diffusion layer and ensures the mechanical strength of the electrode.
The electron conducting properties of the electrode material and of the gas diffusion material derive from this support material and from the carbon inks or pastes introduced mechanically or sprayed on the surface of the support of the diffusion layer to form the charge percolation network.
FIG. 1 shows a schematic view of an assembly of an electrode of the type in question of the prior art. Microporous carbon 1 is generally sprayed on one of the faces of the diffusion layer to support the catalyst layer and to ensure good gas diffusion.
The catalyst layer is a fundamental element of the membrane-electrode assembly. Due to the presence of the catalyst particles 2 (platinum or other noble metals), the hydrogen oxidation and oxygen reduction reactions implemented in the fuel cells occur on either side of the proton conducting separating membrane 3 and thereby permit the generation of electrons.
The formulation of the catalyst layer with low loads of noble metals is one of the key factors in the development of PEMFC type fuel cell. In fact, several economic studies conducted in the early 2000 s have demonstrated that the platinum introduced in the catalyst layers and the forming thereof constituted the second most costly component in the cell. A knowledge of physicochemical and electrochemical transfers occurring in the electrode materials shows that the catalyst particle content in the cell can only be reduced by optimising the morphology of the catalyst zone.
The active layer forming methods most commonly reported in the literature are based on the principle of deposition, on the diffusion layer, of a spray of C/Pt particles placed in suspension in a light solvent, such as alcohol, and incorporating a polymer binder, the latter ensuring the mechanical strength and the water management. Over the last twenty years, a sharp decrease in platinum loads in the electrode material has been achieved.
This decrease was associated with the combination of platinum nanoparticles immobilised on carbon 5 and the use of a proton conducting impregnating film 4 . Thus, the catalytic site becomes active as it integrates the proton conduction network and the electron charge percolation network directly in contact with the particle. This zone is active to the extent of the accessibility of the fuel or the oxidising gas, that is, it is limited by the material input.
In present embodiments, as illustrated in FIG. 1 , the morphology of the active layer is unfortunately not optimal. In fact, only 50 to 75% of the platinum introduced into these active layers is recognised as electroactive. This loss of electroactivity is associated with the poor distribution of the catalyst. The various limitations have the following causes:
non-optimal electron charge transfer, the carbon percolation network then not being continuous from the C/Pt particle to the diffusion layer and through the diffusion layer to the bipolar plates; or by limiting material transport, the catalyst particle no longer being reached by the gas (if for example the platinum is located opposite the carbon particle); or by a proton conduction network (obtained by impregnation with a proton conducting solution or by contact of the electrode with the membrane) preventing access to the catalyst particle.
Optimal formulations of active layers on diffusion layer support have been described. More particularly, the formulation of E-Tek electrodes, sold by DeNora, is reported in documents EP-A-0 872 906 and EP-A-0 928 036.
The literature reports the possibility of improving the performance of the cells by adjusting the methods of incorporation of the proton conductor. By optimising the Nafion content incorporated in the active layer, the kinetic operating range of the fuel cell (low current density range) can be improved. However, for very low platinum loads, this improvement occurs to the detriment of the high current density range, with a limitation by mass transfer being reached more rapidly and an increase in electrode-membrane interface resistance.
The active layers have been the subject of several modelings aimed to determine their optimal organisation, by increasing the geometric surface area of the platinum developed and by minimising the resistance effects associated with the proton conductor and the carbon. Based on these modelings, new structures have been tested, either introducing multilayer structures (alternating catalyst layer and proton conducting film), or fibres impregnated with proton conductor, or porophores. The most satisfactory results were obtained by the introduction of porophoric systems into the active layers, as described in document US 2001/0031389. The mass transfer is improved, thereby serving to meet the demand for operating applications of the cells in air.
In conjunction with the idea of a more open active layer to avoid limiting material transport and to reinforce the electron charge percolation network, the possibility has been developed of directly immobilising the catalyst particles on the diffusion layer support.
This type of operation is reported in the literature with various techniques: pulsed electrodeposition, microemulsion, spray coating, vacuum deposition (EBPVD in document U.S. Pat. No. 6,610,436, CCVD described in document WO 03/015199). However, these various techniques have non-negligible drawbacks.
Microemulsion processes are not suitable for obtaining a controlled particle distribution if directly deposited on the diffusion layer.
In the case of deposits by electrodeposition, the particle size obtained is generally higher than 50 nm and therefore has low electroactivity.
For deposits by PVD, the limitation to this type of process resides in the difficulty of obtaining nanodispersions of catalyst nanoparticles and of locating the catalysts close to the membrane, without losing some depth in order to respond to a higher catalytic activity during power draws.
The ion-beam processes, as described in document U.S. Pat. No. 6,673,127, do not allow a dispersion in depth, in more than 5 nm of the thickness of the diffusion layer.
The standard CVD deposition process has a particle growth yield that is too low for the deposition temperatures required by electrode supports (T<350° C.), or requires the use of alycyclic platinum precursors (see document U.S. Pat. No. 6,162,712) which are unfortunately very unstable at high temperature and in air.
It therefore clearly appears that the catalyst layers currently present in PEMFC type fuel cells, shown in FIG. 1 , have the drawback of immobilising a high catalyst load which remains inaccessible to the proton conduction and gas diffusion network, or blocks the electron conduction.
An obvious need therefore exists to obtain novel catalyst layer structures not having all the above drawbacks and hence to identify a deposition technology suitable for producing such structures.
SUMMARY OF THE INVENTION
Thus, according to a first aspect, the invention relates to a method for fabricating electrodes of fuel cells.
Fuel cell electrodes are defined as the seat of electrochemical reactions (oxidation of the anode and reduction of the cathode), the said reactions only being possible in the presence of a catalyst. In practice, such electrodes comprise a support ensuring the mechanical strength, comprising at least one electron conducting microporous layer, also called diffusion layer, and covered with a catalyst layer and optionally in contact with a proton conducting film.
The method according to the invention is characterized in that the step of depositing the catalyst on the diffusion layer is carried out by DLI-MOCVD, and in that the said diffusion layer is made of porous carbon.
The implementation of the DLI-MOCVD process has certainly been reported in the journal Microelectronic Engineering (64 (2002) pp 457-463), but only for obtaining continuous platinum films for applications related to ferroelectricity.
On the other hand, and in the context of the invention, this technology generates catalyst nanoparticles in a nanometric dispersion and with a rapid growth rate, which prior deposition techniques did not serve to obtain. Accordingly, according to a second aspect, the invention also relates to electrodes for fuel cells having catalyst nanoparticles dispersed in direct contact with the diffusion layer.
In the context of the invention, the type of support on which these nanoparticles are formed is important for preventing the formation of a continuous film. More particularly, the microporosity of the surface layers of the gas diffusion electrodes must be taken into account for the final structure of the electrode material.
Thus, the porous carbon of the diffusion layer on which the deposition is carried out is made for example of carbon, graphite or nanotubes. The carbon may be of the Vulcan XC 72 or Shawanagan type.
To ensure good electrochemical operation, the proton conductor must also be brought into contact with the catalyst. In the prior art, to finalise the fabrication of the electrode material, the proton conductor is sprayed into an alcohol-containing solution thereby covering the catalyst particle distribution zones. According to the invention, the catalyst particles can be deposited on a microporous layer having a proton conductor. For example, platinum particles were deposited by DLI-MOCVD on a carbon layer having an equivalent Nafion® load of 0.4 mg/cm 2 via a Pt(COD) with a precursor diluted in a solvent (toluene) at a temperature of 210° C. This microporous layer can be deposited by spraying a solution of carbon particles mixed with a solubilised proton conductor. The film-forming proton conductor may or may not have the same structure as the separating membrane in the cell.
Conventionally, the catalyst is advantageously selected from the group of noble metals, preferably platinum (Pt). The catalyst particles deposited are preferably monometallic.
Furthermore, the immobilisation of platinum nanoparticles by the method of injecting organometallic liquid by CVD (DLI-MOCVD) can be carried out at high temperature, thereby providing a good bonding of the particles to the substrate. According to the invention, the deposition is therefore carried out at a temperature of preferably between 200 and 350° C.
In fact, for electrode materials, the problem arises of their aging and of the adhesion of the deposit. Studies have shown that the aging of the materials is reflected by a loss of catalyst by elution. The interface of the fuel cell electrodes being in contact with a water flow issuing either from the catalysis of the oxygen reduction, or the humidification of the gases, it is necessary to ensure the adhesion of the platinum particles. Since the production of active layers by spraying is carried out at fairly low temperatures (<200° C.), the adhesion of this type of structure is debatable despite the subsequent steps of hot pressing on the membrane. It is therefore justifiable to consider a method for producing particles at higher temperature on a structure having a good ex post facto cohesion without exceeding the limit temperature of the electrode support of about 350° C. The DLI-MOCVD technology is perfectly compatible with this temperature range.
The presence on the diffusion layer of a proton conductor, a material which has a well known sensitivity to temperature, implies that the method for immobilising the catalyst layer makes use of low temperature deposition, either by the use of specific low temperature precursors, or by the use of the plasma enhanced chemical vapour deposition (PECVD) process.
The principle of DLI-MOCVD is derived from conventional CVD systems. The reactive species are provided in liquid form and injected at high pressure by injectors. Thus, starting with a dilute precursor solution, the product consumption is reduced and can be controlled in volume or mass. This method therefore serves to control the morphology of the particles according to the preparation parameters (the mass of product injected, the injection frequency, the solvent of the precursor and the deposition time) and ensures a rapid and industrialisable production.
In practice, the catalyst nanoparticles are synthesised by DLI-MOCVD at atmospheric pressure or under vacuum (from 1000 Pa to 70 Pa in N 2 —O 2 or H 2 —N 2 mixture), with a deposition temperature of 500° C. or less, using a mixture of precursors such as organometallics (type β-diacetonates, carboxylates) soluble in a common solvent (acetyl acetone, THF, etc.), or using several independent sources of precursors, in the presence of a reaction gas mainly comprising an oxidising reactant gas (for example O 2 , CO 2 , etc.) or a reducing reactant gas (H 2 ).
To agree with the temperature behaviour properties of polymer compounds, low temperature precursors, such as organometallics, having COT or COD arene type groups (PtCOD, PtMe 2 Cp, etc.), are used at the average deposition temperatures (<350° C.).
As already mentioned, the fabrication method according to the invention serves to tend towards an ideal structure, in which the catalyst particles 2 are directly fixed on the electron conductor support which plays the role of a gas diffusion layer 1 ( FIG. 2 ). Thus, the catalysis zone effectively corresponds to the area called the “triple contact point”, where the electron exchanges, the consumption of a gas reactant and the transfer of ionic species take place.
This method serves to obtain a very specific organisation of the catalyst layer. The electrode has dispersed catalyst particles in direct contact with the diffusion layer.
More precisely and as shown in FIG. 3 , nanometer sized metal islands are observed (diameter lower than 50 nm, preferably between 1 and 20 nm), uniformly dispersed with an inter-particle distance of 2 to 30 nm at the surface of the microporous support formed by the diffusion layer.
The distribution of the catalyst particles is especially more advantageous when the proton conductor can be brought into contact with them. Thus and advantageously, the formulation of the microporous support for the deposition of the particles incorporates a certain content of proton conductor, preferably having the same composition as the one constituting the electrolyte membrane. To facilitate the seeding properties of the deposited particles, a plasma gas surface pre-treatment may be carried out.
The method of deposition by DLI-MOCVD serves to ensure good infiltration (above 5 μm of the particles deposited on micro- and nanoporous structures. Thus penetration depths of about 100 μm can be obtained using the method according to the invention, whereas the prior art methods only allowed for penetrations of a few microns, see for example the publication of Brault et al. in the Journal of Physics D: Applied Physics (37 (2004) pp 3419-23).
The penetration into the microporous support is distributed in a decreasing concentration gradient from the surface of the said layer, thereby meeting the various power draw conditions of the electrochemical reactor.
Due to the chemical nature of the deposited particles (noble metals or metal oxides) and the morphology of the deposits (a large number are very well dispersed nanometer sized active sites), the active layers used in the present invention appear to be highly efficient for the electrocatalysis of the reactions generated in fuel cells. This performance serves to obtain electrodes having catalyst loads, particularly of platinum, not exceeding 0.2 mg/cm 2 .
The fuel cells and storage batteries comprising such electrodes are also part of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and the advantages thereof will appear more clearly from the exemplary embodiments that follow, provided for information and non-limiting, in conjunction with the appended figures.
FIG. 1 is a schematic of the membrane/electrode assembly according to the prior art.
FIG. 2 is a schematic of a catalyst deposit according to the invention.
FIG. 3 is a micrograph of a catalyst deposit obtained according to the invention.
FIG. 4 shows bias curve obtained in the exemplary embodiment in H 2 —O 2 .
FIG. 5 shows bias curve obtained in the exemplary embodiment in H 2 — air (T=80° C.; P=4 bar absolute).
FIG. 6 shows platinum penetration profile in a porous carbon diffusion layer.
FIG. 7 shows platinum infiltration into microporous carbon, measured by X-ray analysis.
DETAILED DESCRIPTION OF THE INVENTION
The examples presented below were prepared using a vapour deposition device sold by JIPELEC under the name “Inject, Système d′ injection et d′évaporation de précurseurs liquides purs ou sous forme de solutions”, coupled with a chemical vapour deposition chamber.
The JIPELEC device comprises several parts: the storage tank for the chemical solution, an injector (petrol, diesel) connected to the liquid tank by a feed line and controlled by an electronic control device, a carrier gas feed line, and a vaporisation device (evaporator).
The deposition chamber, which contains the substrate to be coated, comprises a heating system, a gas feed and pumping and pressure control means. The deposition chamber and the substrate are heated to a temperature above that of the evaporator, in order to create a positive thermal gradient.
The chemical solution is introduced into the pressurised tank (2 bar in the present case), and sent via the injector or injectors by pressure differential into the evaporator.
The injection flow rate is controlled for frequency and opening time by the injector.
This type of installation can easily be inserted in a continuous production line for electrode materials.
The method used is suitable for forming large electrode surfaces (>2 500 cm 2 ).
In the deposition conditions stated below, the platinum (Pt) nanoparticles are prepared on a commercial diffusion layer substrate of the ELAT type (product E-Tek, sold by De Nora).
The chemical deposition solution comprises the organometallic Pt precursor (acetylacetonate), dissolved in a solvent (acetylacetone).
The temperatures of the evaporator and the substrate are set respectively at 220° C. and 340° C.
The other operating conditions of the two examples are given in Table I below:
TABLE I
Operating condition supplied for tests 1 and 2.
Injector
N 2 /O 2 flow
Injector
opening time
rates
Deposition
Concentration mol/l
frequency (Hz)
(ms)
(cc)
Pressure (Pa)
time (min)
Test 1
0.03
2
2
40/160
800
30
Test 2
0.03
2
2
40/160
800
20
The bias curves ( FIGS. 4 and 5 ), obtained in a cell test with assembly, concern electrodes according to the invention. These curves reveal an improvement in mass transports at high current densities under air pressure ( FIG. 5 ).
This behaviour is related to the more open structure of the electrode material having a thinner catalyst layer than the standard carbon-supported platinum deposits.
The electrode material according to the invention is suitable for operation in air.
Performance in pure oxygen ( FIG. 4 ) is similar to that of the commercial products using carbon-supported platinum catalysts. However, it is important to note that the platinum loads are 0.17 mg/cm 2 for deposition of 30 minutes and 0.11 mg/cm 2 for deposition of 20 minutes respectively.
In comparison with the commercial materials prepared with carbon-supported platinum (platinum load=0.35 mg/cm 2 ), the electroactive surface liberated with an electrode according to the invention is therefore 40% larger.
FIGS. 6 and 7 illustrate the platinum penetration profiles in a porous carbon diffusion layer.
More precisely, FIG. 7 shows an X-ray mapping of the platinum on microtomy section (magnification: ×1500). This is an electrode loaded with 0.15 mg/cm 2 of platinum. The deposition was carried out under the following conditions: 3.5 Hz; 30 minutes; Pt(COD) precursor=dimethyl 1−5 cyclooctadiene platinum (II) in xylene in a concentration of 0.025 mol/liter, with a substrate at 244° C. and under 1000 Pa. The infiltration of the catalyst into the microporous carbon is observed to reach a depth of about 100 microns. This considerable depth illustrates the advantage of the DLI-MOCVD technique compared to the other methods which only allow penetration of a few microns.
The method according to the invention and the electrodes described in the context of this invention therefore have substantial advantages. Among them, mention can be made of the following:
the fabrication of electrodes for PEMFC (Proton Exchange Membrane Fuel Cell) fuel cells with low catalyst load is suitable for reducing costs and for high electrocatalytic activity allowing improved performance; the possibility of industrialising a continuous fabrication method; the possibility of having a rapid and controllable growth rate in the context of such a device; elimination of the post-sintering or pressing steps, necessary in the prior art methods; improved mass transfer properties; formulation of the catalyst layer support incorporating the electron charge percolation network (carbon network) and the proton transport network; improved catalyst behaviour thanks to deposition at relatively high temperatures.
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A method for fabricating an electrode for electrochemical reactor is provided, wherein the electrode includes a porous carbon diffusion layer and a catalyst layer. The method includes a step of depositing the catalyst layer on the diffusion layer by a DLI-MOCVD process.
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FIELD OF THE INVENTION
[0001] The present invention relates to engine- and compression technique
TECHNICAL BACKGROUND
[0002] It is a lot of engine- and compression techniques today that's built on pressure and expansion of air by combustion, to run an engine, turbo and turbine. Common for them is low thermal-efficiency, as compression before expansion is energy demanding. There is also many movable parts, and other parts which have to be assembled in current engines and compressors making them complex, expensive with a low wear ability and running-stop. To avoid this, frequently maintenance has to be done.
[0003] The gas turbine is one of the most energy economical, and safe running engines today. But it is still a lot of resistance and energy loss in the compression process and the engine is complex and expensive, besides it is not energy economical when partially loaded, and therefore it is less suitable for instance as car engines.
SUMMARY OF THE INVENTION
[0004] It is an object of the invention to provide a rotating device producing pressure by centrifugal pressurized fluid (liquid, gas or plasma) that afterwards is expanded, and including a U-channel structure that includes an expansion point at the periphery of the rotating device, and which includes a sink channel in said U-channel structure, and said sink channel is a pressure channel for supply of pressurized fluid to said expansion point, and which include a rise channel in said U-channel structure for transport of said expanded fluid from said expansion point, to an outlet channel for said pressurized fluid to a regulation valve for supplying said fluid of high pressure into an outlet channel for said pressurized fluid to an energy utilizations device, and drive means to rotate said U-channel structure, wherein said sink channel and rise channel is connected together at the periphery and arranged radial on the shaft in said device, and said U-channel structure is connected to the shaft in balance with two or more U-channel structures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The invention will now be described in detail in reference to the appended drawings, in which:
[0006] FIG. 1 is a longitudinal principle sketch through the first embodiment of the invention,
[0007] FIG. 2 is a cross section of inlet side in sink channel through the embodiment shown in FIG. 1 ,
[0008] FIG. 3 is a cross section of outlet side in rise channel through the embodiment shown in FIG. 1 ,
[0009] FIG. 4 is a longitudinal principle sketch through another embodiment of the invention, with an example of connections to existing energy utilizations devices,
[0010] FIG. 5 is a cross section of inlet side in sink channel through the embodiment shown in FIG. 4 ,
[0011] FIG. 6 is a cross section of outlet side in rise channel through the embodiment shown in FIG. 4 ,
DETAILED DESCRIPTION
[0012] FIG. 1 shows the principal parts of the invention, namely a cylindrical drum or disc-like structure 120 with hollow shafts 121 , 122 . The shafts 121 , 122 are suspended in bearings and connected with drive means arranged to rotate the disc 120 (not shown). The structure includes an inlet channel 103 , in which fluid (example air) is supplied to compression and expansion. The inlet channel is placed in the centre of the shaft 121 , and branches out in a sink channel 104 . The fluid will be thrown outwards in the sink channel 104 due to centrifugal forces. The sink channel 104 may be realized as a flat disk-like chamber, possible with vanes, or as tubes or hollow spokes leading from the centre part of the disc to the periphery. In the embodiment shown in the figure, the vanes 123 will also act as support elements binding the structure together between the channel partition disk 109 , and outer part of the U-channel structure 120 and shaft 121 , 122 . At the periphery, the pressurized fluid will get in contact with propellant nozzle 106 and spark plugs 111 , respectively. The propellant nozzle 106 is supplying propellant in the propellant channel 102 from a drag chamber (not shown) arranged on the shaft 121 . The spark plug get high-voltage trough electrical conductor 101 from a slip ring on the shaft 121 and trough the disc structure 120 which is earthed (not shown).
[0013] The propellant nozzle 106 and the spark plug 111 are located at the periphery in said U-channel, so that propellant from propellant nozzle 106 will be mixed together with fluid. The mixture will ignite in expansion point 105 of the spark from the spark plug 111 , after the propellant nozzle 106 . The spark will stop after ignition. The expanding fluid will be pressed by the heavier fluid from sink channel 104 further over to the rise channel 107 , which may be a disc-like chamber with radial walls 123 , or a plurality of tubes or hollow spokes, similar to the input- 103 and sink channel 104 . The rise channel 107 is connected to an output channel 112 in the centre of the shaft 122 , and further to a regulation valve 110 which is adapted to regulate the fluid output at optimum pressure and mass. The regulation valve 110 can be closed 310 a, or open 310 b.
[0014] The present invention is a rotating device where it is arranged two or more U-like channels arranged radial 120 , and in balance on the shaft 121 , 122 with inlet- 103 and outlet channel 112 in, or around the shafts 121 , 122 . During high rotation, the fluid (example air) will because of its mass be pressed by centrifugal forces out towards the periphery of said U-channel. There fluid from inlet channel 103 is branched out in several sink channels 104 , and it is connected together with channels from periphery to outlet channel 112 with rise channel 107 . At high rotation, the fluid will be pressurized by its mass towards periphery in sink channel 104 . Then more fluid will flow into the sink channels 104 (when fluid are at compressible phase), and it will press the fluid further together. It will be a static-like high pressure of the fluid in the channels at periphery. In the invention, the pressure can be constant there in the process, when the rotation is constant. And at the beginning is the heavy-density in balance between sink channel 104 and rise channel 107 , but when influence on the fluid to lower heavy-density and then lower weight by expansion (example by said combustion) from expansion point 105 in the fluid channel at periphery and up rise channel 107 , some of the fluid will expand out through outlet channel 112 . Then it will be unbalance between the fluid in sink channel 104 and rise channel 107 causing the heavier (example colder) fluid from sink channel 104 to be pressed at the periphery over to rise channel 107 and pressing the fluid there further to outlet channel 112 . By the continuous influence to expand (example combustion) the fluid, when it continuous passes through the expansion point 105 at the periphery, it will form a continuous move towards outlet channel 112 . A pressure regulation valve (example adjustable stator blades) 310 in the outlet channel regulates the output pressure optimally, so that the fluid in said U-channel only moves itself towards the output channel. And due to the higher expansion (lower heavy-density) in rise channel 107 , the higher pressure out of the invention device after the pressure regulation valve 110 and by doubling the volume in rise channel 107 compared with sink channel 104 , the theoretical pressure out will be 50% of the pressure at periphery. By five times volume expansion, the pressure at the regulations valve in outlet will be 80% of the pressure for the fluid in the channel at the periphery and so on. The centers of gravity of the fluid in rise channels 107 will be nearer the shaft and the sum of the mass there will therefore experience a lower centrifugal force than the fluid in sink channels 104 where the centers of gravity are nearer the periphery, because of larger pressure difference from input to periphery (with compressible fluid), compared with rise channels 107 with less pressure difference between periphery and outlet channel, and therefore will said percent for pressure out be higher.
[0015] There are several methods to increase the density (reduce volume) of the mass in sink channel 104 and to reduce the density (increase volume) of the mass in rise channel 107 , like for example:
[0016] For sink channel 104 to expanding point 105 : n and/or before sink channel the fluid can be a liquid, or at gas phase and cooled for higher density, and/or the fluid can be pumped/pressurized to inlet channel 103 .
[0017] For rise channel 107 from expanding point 105 : The fluid can for instance be heated up within same phase, or over one or more phases, or be split for lower density with catalyzing and/or electrochemistry, or similar, or any combination of said examples.
The Advantage of the Invention
[0018] The advantage of the invention is that pressure regulation 110 of the fluid output creates a higher pressure out 112 than in 103 , in the device. The tangentially acceleration force on mass out towards periphery 104 will practically be returned by the tangentially retardation force of the same mass with transport from periphery, back to shaft in closed channels 107 . When the rotating device is arranged inside a evacuated housing (not shown), it will be minimal rotary resistance, noise and heat loss. The device is compact, and with few movable parts, which give less frequently maintenance. In the device, the produced output pressure can be used to produce energy.
[0019] The pressure from the inventive device can be conducted via energy utilization devices such as: -turbo generator, -turbo loader, -turbine generator, -pressure motor, nozzle or injector for propulsion, or similar, or to accumulate the pressurized fluid.
[0020] Said connected energy utilization devices can be adjusted optimum for a flow-through-velocity, in such a way that regulation valve 110 for optimum pressure out is less necessary, and will therefore get a better energy economy.
[0021] Said energy utilization devices such as: -turbo generator, -turbo loader, -turbine generator, -pressure motor, can be installed external with connected channels for fluid from the invention device. Or arranged on the same shaft as the inventive device. Using for instance an axial turbine on the same shaft, the inventive device will be like a centrifugal compressor-gas turbine/jet motor which is less energy economical than the current inventive device. For instance is the compression more energy demanding, for the tangential acceleration force (in sink channel 104 for the invention) will not be returned by the tangentially retardation force (in rise channel 107 for the invention) of the fluid, as in the invention. In addition, a centrifugal compressor-gas turbine will have much more friction tangentially. This will nearly not occur in the present invention, where the fluid practically have only friction axial and radial, which is relative low when the fluid move by itself in the closed channels 103 , 104 , 107 , 112 in the rotating device, and the outside of the channels rotates in vacuum. The fluid have relatively much higher periphery velocity then the flow through velocity in the channels, and when the fluid only are in contact with the s channel walls, which on the outside are in vacuum, and with that the current rotating device can have a very high and constant rotation, without worth mentioning rotation resistance, and at same density on the fluid in sink channel 104 and rise channel 107 , said fluid will not move in the channels, but when expansion in rise channel 107 , it will immediately move when during rotation and form a pressure out as said earlier for the present invention.
[0022] FIG. 2 is a cross section through the U-channel structure 220 shown in FIG. 1 , in area of propellant nozzle 206 and spark plug 211 . The fluid move into the device through inlet channel 203 in centre and is forced to out towards to the periphery, and tangentially accelerates along the shovel 223 . But the radial velocity can be constant when the fluid is pressurized in sink channel 204 where it get in contact with the propellant nozzle 206 which added in proper quantity propellant. The spark plug 211 form a spark between the propellant nozzle 206 that start expansion of the fluid in expanding point 205 , and then it will move first tangentially in the rotation direction, before it will be pressed further axially in to the periphery of rise channel 207 . The figure also shows propellant channel 202 , and the insulated conductor 201 for high voltage to spark plug 211 .
[0023] FIG. 3 is a cross section through the U-channel structure 320 shown in FIG. 1 , in the area of propellant nozzle 306 and spark plug 311 . The fluid will get in contact with the propellant nozzle 306 that add in proper quantity propellant. Then, the spark plug 311 form a spark between the propellant nozzle 306 which start expansion of the fluid in expansion point 305 , whereupon it will moves first tangentially in the rotation direction, before it will be pressed further axially in the periphery and then up along the shovels 323 and then tangential retards in rise channel 307 , and the radial velocity can be constant, and the fluid will be pressed further out in outlet channel 312 to regulation valve 310 which can be regulated between closed 310 a or open 310 b. The figure also show propellant channel 302 , and insulated conductor 301 for high voltage to spark plug 311 .
[0024] However, if the structure must be run at a lower temperature, for example because of the material at high rotation does not tolerate high temperature to expand the fluid, the energy supply can then be reduced and/or the heat can then be reduced on the U-channel structure with heat exchange channels which surround said fluid channels from inlet to outlet by supplying such as water or steam or other suitable cooling medium in said heat exchange channels in inlet, in proper quantity and pressure. Said heat exchange channels can be fitted with several longitudinal walls which are fastening to the outer side of the fluid channel and to the inner side of the heat exchange channels, both for better heat exchange and to strengthen the structure. The walls can be perforated with several adapted small holes, or fewer larger holes, which each have a sharp edge in the direction to the centre of the hole, to get less resistance. The holes are in equal distance both for lightening the weight and to equalize the pressure of the cooling medium between the walls. In the same way, it can be arranged corresponding longitudinal walls in the fluids sink channel, so the cooling medium can cool down the fluid there, for further compression of it, when it is compressible. The cooling medium, which can be water, will thereby be endothermic first from the compressed fluid and afterward from the energy supplied by the heat exchange from the expansion of the fluid. The heat exchanging changes the cooling medium up its rise channel to be over heated dry steam, which can be water steam, that have essential lower density then the water in heat exchanges sink channels, and a corresponding output pressure effect is achieved also in the heat exchange U-channel structure, like for the fluid channels U-channel structure.
[0025] FIG. 4 shows a principle sketch of another embodiment of the invention, in which four pipes form said U-channel structure 431 , and which is fastened radially and in balance towards the shaft which belongs to inlet- 405 and outlet channel 409 . The fluid channels is; Inlet channel 405 , sink channel 406 , rise channel 407 , and outlet channel 409 and they are surrounded by heat exchange channels; inlet channel 408 , sink channel 423 , rise channel 424 and outlet channel 417 .
[0026] The rotating pressure production unit is encapsulated and fitted in an anchored evacuated housing 413 with bearings and gaskets 414 around the inlet shaft, and only a bearing with inner gasket at outlet shaft 416 with possibility for a flow through round bearing house 416 . The evacuated housing is further fitted and tightened around the end of the turbine house 415 which does not rotate, and a vacuum is established inside the housing 413 by the vacuum pump 401 . The rotating unit starts the rotation with help from a pressure start motor 403 which receives supplied fluid (for instance air) from an accumulator tank 411 via its regulations valve 421 . By regulation of pressure fluid to the pressure start motor 403 , its drive wheel will be pushed in contact with the shaft in the invention. When the rotating speed has been established, the valve 421 will close and the start motor's drive wheel will retract and out of contact with drive wheel on the shaft, and a rotation maintenances motor 404 take over for constant rotation.
[0027] At the start of rotation, some water be pumped in to heat exchange channel 408 , such as the water level will be in proper distance from periphery in its sink channel 423 and rise channel 424 . At the same time the valve 419 will open for supply from accumulating tank 411 pressurized fluid to injector 422 which is fitted to pull with more fluid from the ambient (air), or from a channel to supply other fluid (not shown) and in to inlet channel 405 . Then the cooled fluid will be pressed to the sink channels 406 where the heavy density from the fluid will pressurized further by the centrifugal force through the periphery where its maximum pressurized, and where the fluid also gets in contact with the propellant nozzle 427 where an adapted amount propellant mixing together with the fluid, to be conducted further to the spark plug 428 (supply channel for propellant and the same for insulated conductor for high voltage to spark plug, is not shown, but can be as in FIG. 1 ) which ignite the propellant, so it will expand at constant pressure further over at periphery and up rise channel 407 , and out channel in shaft to fluid slip chamber 409 which not rotate, and is connect with channel to turbine 410 . From slip chamber 409 the expanded fluid can go in two directions. One of them is to turbine 410 , which inside can have regulated stator blades similar to 310 in FIG. 3 , or similar which in the start is closed, in such a way that the fluid will be conducted in other direction for recycle channel from slip chamber 409 to an heat exchanger and condenser 420 , where moisture in the fluid separates out 426 , so dry and cold fluid further will be pressed via regulation valve 419 which is accommodated for passage of accumulated fluid from accumulator tank 421 . The recycled fluid will be pressed further in accommodated amount to injector 422 which will pull more and new fluid into inlet. In this way, the pressure will build up in the device, and by accommodated pressure valve 419 to accumulation tank will be closed, when it is loaded up, causing new and partly recycled fluid to be conducted directly to injector 422 . Simultaneously, the regulated stator blades at turbine 410 will be opened, where some of the pressurized fluid can be energy utilized further, and the rest of the fluid recycle back in a proper amount to injector 422 to keep up the pressure in fluid to turbine 410 , or similar energy utilized device as said.
[0028] At the same time, the water in heat exchange channels sink channel 423 will be heated up from pressurized fluid in its sink channel 406 when fluid is at compressible phase, and the fluid will then also become thermally compressed, and then be compressed further of the centrifugal force, and the water will at periphery in its heat exchange channel 424 cool down the wall to rice channel 407 where the fluid expand during combustion, and then will the cool medium/water change to steam, and nearer shaft and out channel in shaft to slip chamber 417 and further till after steam turbine 418 will the steam be dry, before it condensing in the low pressure condenser 412 where the condenser can be supplied with more water 425 and/or the water is pumped (not shown) back to the heat exchange channels slip chamber 408 , and to a new cooling round.
[0029] The heating up of the cooling medium/water from the fluid in the U-channel structure, will at proper regulation out, the expanded steam press the water level out towards to the periphery at heat exchange rise channel 424 so that the water level get out to the periphery, but it is more favorable that the water level is higher up in heat exchange rise channel 424 . Something that can be carried out by increase the pump pressure to inlet channel 408 , or increase the rotation speed, or supply more water to increase the water level in heat exchange sink channel 423 when the water level from earlier is low there. And it is a valve at inlet (not shown) in the device which is accommodated to get out gas, when the sink channel is filled more up, and this is for all inlet channels when the medium is at liquid phase. At inlet to all channels in the rotation s device can it be nearly vacuum, with an accommodated pressure at outlet for each channel in the device and the pressure at periphery is more than twice as much as the pressure at inlet.
[0030] It is also possible to install a turbo charger (not shown) between slip chamber 409 and heat exchanger 420 and/or between steam slip chamber 417 and steam turbine 418 where pressurized fluid/steam in the turbo charger compressing new fluid which can be conducted via heat exchanger and condenser 420 where moisture in new fluid is separated out 426 , before dry and cold new fluid is pressed further either direct to inlet channel 405 trough a own slip chamber (not shown) or similar, or to injector nozzle 422 . Similarly it can be connected a fluid turbine charger/compressor on either axial turbine 410 , steam turbine 418 , or it can be connect to and from shafts inlet 405 then the last-said will be like a gas turbine, where the inventive device will be between the axial compressor and expanding turbine. The combustion chamber and expansion chamber will then be similarly as rise channel 407 .
[0031] Energy utilizations turbines 410 , 418 can be installed on the same outlet shaft (not shown) in the inventive device, with separated supply channels, and/or it can be a high pressure steam turbine on the shaft, and the steam after it can be leaded in a channel back by the rise channel (not shown) for after heating, Which can be in an own U-channel structure, which again increase both pressure and temperature, before the steam is leaded out 417 to an low pressure turbine which can be like 418 on FIG. 4 and further to a condenser 412 .
[0032] By adjusting to equally pressure between the fluid in rise channel 407 and steam in heat exchanger channel 424 is it with that possible to couple rise channel 407 and heat exchange channel 424 together to one common rise channel (not shown), from a adapted point between periphery and shaft. Then will steam and fluid mixed together be leaded out in a common outlet channel (not shown) to a common turbine similar to 418 ore fastened on shaft and/or direct to nozzle(s) for propelling. Or the water condenser out after turbine and cleans before it recycles back to the invention. Where the said rise channels are coupled together to one common channel, can the substances from the rise channels be leaded first in to a common circular-shaped channel a round shaft, where the rise channels with different substances are connected at the periphery of the circular-shaped channel which the common channels out are connected at inner side of the circular-shaped channel towards the shaft and out.
[0033] By supply of hydrocarbons (not shown) together with water/steam in rise cool channel 424 at proper amount, for instance 2 kg water/steam or more per 1 kg hydrocarbons, where water and hydrocarbons up in heat exchange rise channel 424 will indirectly be heated up and in addition directly by thermal beams, when the channel wall between is of a material which tolerate thermal beams to pass through. Then will the water/hydrocarbons convert into hydrocarbon-water-steam from the heat of the fluid in rise channel 407 , and in the heat exchange channel 424 will the most of the hydrocarbon-water-steam be split to hydrogen and CO by proper heating, and to pull out more hydrogen from the substance and as to convert CO to CO2 can it in the heat exchange channel 424 from a propitious point be fastened chrome-iron-oxide-catalyzers and/or nickel catalyzers (not shown) and in its outlet channel in shaft and inside in slip chamber 417 and channel to turbine 418 and the first stator blade an rotor blade there, can also be of said catalyzers or covered by nickel/chrome-iron-oxide, or alloy with this. Further in steam turbine 418 from a propitious point can stator blade and rotor blade be of, or covered with zinc, and from propitious point the rest inside the turbine and out can be of, or covered with copper, inside the turbine housing can it be placed said catalyzers at the same place. In this way it can with propitious temperature and pressure, formed a steam reforming system, which also catalyzing out hydrogen from the hydrocarbon-water-steam when it pressed out through said channels and turbine(s), and the gases condensates out and separates in the condenser 412 . The hydrocarbon-water-steam can also after outlet 417 pass through several propitious catalyzers chamber (not shown) in said order, where they inside are filled with said catalyzers with most possible surface area, and between the catalyzers chamber it is coupled turbines which adjusting the adiabatic temperature and pressure for optimum catalyzing. With said catalyzers chamber it is less need for said catalyzers in channels 424 , 417 and turbines 418 . With supplied more water than necessary in the hydrogen production process, will said water after the steam process and steam turbine 418 be condensed back to water in condenser 412 , or the water can condensate out in a condense chamber for water/steam between high pressure turbine and low pressure turbine. And if CO2 is influenced within critical temperature and pressure, can also CO2 be separated out on the same way in/or after the water condenser and possibly turbine. As a result, will practically clean hydrogen be leaded out, either via a turbine, where it at front edge can cool down the hydrogen, or the hydrogen leads direct to accumulation (not shown). Some of the produced hydrogen can be propellant for said fluid to expanding, and it will give a cleaner combustion which also produces water/steam. Or said steam reforming system is connected to one or more of said clean motor-/compressor units (not shown).
[0034] From above where an common rise channel (not shown) is said for fluid/steam, can this also be done for said steam reforming, but then the fluid in inlet 405 should be clean oxygen or mixed with other gas at adapted amount, density and pressure in proportionality to combustion of propellant for heating of said mix of water-hydrocarbon in heat exchange channel 424 .
[0035] FIG. 5 show a cross section through the U-channel structure 531 shown in FIG. 4 , in area of propellant nozzle 527 and spark plug 528 . The fluid move in to the device through inlet channel 505 in centre and are forced out towards to the periphery, and tangentially accelerates, but the radial velocity in the pipe can be constant when the fluid will be pressurized in sink channel 506 where it get in contact with the propellant nozzle 527 who added in proper quantity propellant, and the spark plug 528 form a spark between the propellant nozzle 527 which start expansion of the fluid, and then it will move first tangentially in the rotation direction, before it will be pressed further axially at the periphery into rise channel. The figure do not show propellant channel and insulated conductor for high voltage, but it can be like as in FIG. 2 but they only will be is leaded out into each U-channel structure 531 . Heat exchange inlet channel 508 for water leads further to heat exchange sink channel 523 which surround the fluids sink channel 506
[0036] FIG. 6 show a cross section through the U-channel structure 631 shown in FIG. 4 , in the area of propellant nozzle 627 and spark plug 628 . The fluid will get in contact with the propellant nozzle 627 who added in proper quantity propellant, and the spark plug 628 form a spark between the propellant nozzle 627 which start expansion of the fluid, which will move first tangentially in the rotation direction, before it will be pressed further axially in the periphery and then up into rise channel 607 and then tangential retards, and the radial velocity can be constant such as the sink channel. The fluid will be pressed further out in outlet channel 609 to regulation valve (not shown) which can be like 310 from FIG. 3 , which can be regulated between closed 310 a or open 310 b.
[0037] Whilst the embodiment of the invention shown in FIG. 4 have the U-channel structure two channels (heat exchange- and fluid channels), can the U-channel structure be fitted with more channels for supply in/out with various substances
[0038] The U-channel structures in the figures is shown in axially direction, but they can be placed in any kind of direction on the shaft from 0° as shown in the figures, and up to 180°, and in the area of last said degrees, will fluid from inlet to outlet pass through like in a loop via the U-channel structure. The U-channel structures may also be placed in area 90° one way on the shaft such as the fluid at the periphery moves in the channels there in the rotation direction, and when they is placed 180° of this, will the fluid at periphery move opposite of the rotation direction.
[0039] The U-channel structure from FIGS. 1 , 2 and 3 with disk-like structure, can be combined at periphery (not shown) where the U-channel structure is prolonged radial by pipes in combination with FIGS. 4 , 5 and 6 . Where the respectively channels is connect together for higher rotation and capacity. In the same way can the U-channel structure be as shown in FIGS. 4 , 5 and 6 , or the U-channels to disc-structure 120 connected at periphery with more conic-formed pipes, which is placed into each other, in an outer conic pipe, which is tightened at the end on the tip out at periphery. The interval inside between the pipes and channel in the innermost pipe is connected to theirs respectively in-/out channels by the periphery at the disk structure, and with two conic pipe including the outmost, where outmost as said are closed at periphery, and the innermost pipe are open at periphery. Then the innermost pipe channel can be either sink channel 104 or rise channel 107 , and the interval between the pipes must then be the opposite of what the innermost channel is. And the innermost is pipe must at periphery be placed/mounted on the inner side wall of the outer most pipe in rotation direction side, when the innermost pipe is rise channel 107 , because when the fluid is rise from periphery after expansion, it will try to keep its periphery velocity, so the fluid with that will try to moves tangentially in the rotation direction. When the innermost pipe is sink channel 104 , it then have to be placed/mounted on the inner side wall of the outer most pipe towards rotation direction side, accordingly opposite of, as said, for rise channel. The opening in the end of the innermost pipe at periphery, may be formed as a half-moon structure, where the outer convex is placed/mounted at the concave inside to the outermost pipe. Instead of the innermost pipe it may also be putted in at same length a partition wall, which is mounted and tightened towards inside of the pipe in a axial direction, where the sink channel 104 is at the back side of said plate/wall in the rotation direction, and the rise channel 107 is on the opposite side of said plate/wall, and the channels is connected to the disk-structure to theirs channels. Such can it be formed more U-channel structures along the periphery at the disk-structure, so that the conic pipes, or with a plate in the middle form a U-channel angle between the shafts in about 90°. Said conics pipes and plate can in the construction include heat exchange channels, which is connected at periphery to form a U-channel, which further is connected at periphery at the disk-structures sink-/rise heat exchange channel for in-/out supply of cooling medium. Propellant nozzle 106 and spark plug 111 can be connected to at the periphery of the conic pipes as in FIG. 1 .
[0040] It is propitious if the U-channels is completely or partly in radial length, is bended backwards in the rotation direction, for to utilize the resultant force between the centrifugal force and tangential force which increase the pressure at the periphery. It will simultaneous also lighten the fluid/medium up rise channel, since the resultant force from the tangential retardations force and the centrifugal force will act more towards the rise channel wall, than longitudinally the channel as the fluid/medium will be pressed upward in its rise channels.
[0041] At expanding point 105 and in periphery of sink channel, can it be arranged a combustion chamber (not shown) which can include least one propellant nozzle 106 and least one spark plug 111 at periphery of the said chamber.
[0042] When the present invention is like disk-structure 120 , can the combusting chamber lie/mounted along the periphery with same radius from shaft through all U-channels for fluid by the passage to periphery of rise channels 107 with same axially distance on the present circular combustion chamber channel, which at tangentially cross section can look like a U- or V-profile, where the tip lie radial outwards, and straight above periphery of rise channel 107 . The combustion chamber channel is at the outside fastened to the shovels 123 and with a passage channel in them, and in addition it is from the top (towards shaft) of the combustion chamber channel, is it mounted on the outer side several radial plates, similar to the shovels 123 which they also are axially parallels with. Between the inner walls on the rise channels 107 and outer wall on combustion chamber channel is it now passage for some of the fluid, which indirectly will heat exchange and reduce temperature on combustion chamber channel, and the other structure in the area. The rest of the fluid leads in to combustion chamber channel through a lot of fitted hole distributed proportionally in the combustion chamber channel wail, to cool it down, and for supply of optimum amount fluid (for instance air) to combustions the propellant which expand with the fluid, and when it is radial upstream it will move tangentially in the combustion chamber channel (will try to keep periphery velocity) before the combusting fluid afterwards will mix together with the rest of the fluid, and pressed afterwards up rise channel 107 and out. The pressure before the combustion chamber channel can be fitted such that it will be in completely or partly buoyant balance, so that it will float on flow trough of the fluid, that will give less possibility for deformation, especially at high temperature in the combustion chamber channel. Then the flow through will be at its maximum.
[0043] The spark plug 111 is so far explained that it is at the periphery of the U-channel structures, but least one or more can instead be placed at a propitious place between where the spark plug 111 is shown at the figure and outlet 112 . When spark plug is placed in said area, and the inventive device actuate for rotation, simultaneous as propellant is supplied to fluid from the propellant nozzle 106 at periphery, and fluid simultaneous pressed in to inlet 103 . Then will fluid mixed with propellant moves to outlet 112 , there the mix will be ignited by the spark plug 106 in said aria, whereupon regulation valve 110 regulates the outflow of fluid in such a way that the fluid mix between nozzle 106 and outlet 110 do not move faster than the flame velocity to propellant, like this can the flame get down to expanding point 105 at periphery, or to said combustion chamber channel, where the flame will be kept, however if flow through increase.
[0044] Propellant can also be combusted by spontaneous combustion, if compressions temperature is higher than the flame point for the propellant when the fluid is gas. If compression temperature for spontaneous combustion is not attainable at normal running, can the propellant be ignited by a adjusted shock pressure of fluid at inlet to achieve necessary spontaneous combustion at expanding point 105 , and the flame maintenance afterwards in said combustion chamber channel, where the flame will be kept. It will then be less necessary with spark plug, which can be omitted. Regulations valve 110 at outlet can temporary be completely or partly closed when said shock pressure runs.
[0045] Propellant nozzles 106 is so far explained placed at periphery of the U-channel structure, but least one or more can instead be placed at a propitious place between point as explained 106 and inlet 103 . By placing of the propellant nozzle(s) 106 in this area, must the flow through velocity for the fluid mixed with propellant, always be higher than the flame velocity with passing through expanding point 105 or said combustion chamber. At said spontaneous ignition from the compression heat, must the compression heat to achieve this be as near the periphery as possible, and the flow through in ignition area must be higher than the flame velocity, for to bring the expansions over to rise channel 107 , where the flow trough velocity can be lower and/or the fluid mix will be influenced to turbulence at for example said combustion chamber. Or the combustion ends in said combustion chamber as said for chock pressure when the compressions heat is lower than spontaneous ignition temperature at normal running.
[0046] Least 2 sink channels 104 and in balance, can it inside also be fluid mixed with adapted amount propellant which leads directly through channel to the bottom (periphery) and into combustion chamber, where the supply channel can be bended forward in rotation direction at bottom of combustion chamber, in such a way that the fluid mix will be given a tangential direction in rotation of the device in combustion chamber channel for better mixing with the other fluid.
[0047] All U-channels for fluid, cool medium or U-channels for other substances, may have one or more adapted outlet channels which is coupled with nozzles at periphery (not shown), where slag substances and some of the fluid, medium or other substances from the respectively U-channels leads via nozzles out at periphery and over to an adapted common spiral diffuser, which is fitted to the evacuated housing which not rotates, or one spiral diffuser for each U-channel and its fluid, medium, other substances and slag substances. At said outlet at periphery can it also be mounted valves which regulate the outlet when needed. In sink channels where the fluid may be at gas phase can it in inlet or through nozzles at propitious place in the sink channels, where it's needed, or continuous be supplied a adapted liquid-fluid (for instance water) with adapted amount, it will then be a dual-purpose of thermal compression in the gases and also clean the gas channels at periphery outside of combustion chamber, When the said liquid-fluid (e.g. water) partly will evaporate, and the mix of liquid-fluid-slag-substances is transported to the nozzles along the periphery and out to spiral diffuser. Said liquid-fluid can also cool down the inventive device for maintenance of the strength.
[0048] Said outlet nozzles at periphery can be arranged in such a way that they gives push force in the rotation direction. In such a way that they can completely-, or with a participations to give rotation velocity. In said spiral diffuser, must the substances from the nozzles be thrown outwards in the spiral, this dependent on the resultant direction between periphery velocity and the out blowing velocity and direction for the substances, which determines if the spiral have to be mounted opposite of-, or in the rotation direction. Said spiral diffusers can be adapted for injector effect, which will form a under pressure inside the evacuated housing.
[0049] The present invention is so far explained with two shafts ends 121 , 122 . With inlet- 103 and outlet channels 112 either inside or round the shafts ends. But the inlet shaft 121 can removes (not shown) so the inlet area 103 can be larger, and The U-channel structure 120 are then fastened and strengthened to the outlet shaft 122 , and on the opposite end of the outlet shaft 122 can it be mounted a corresponding U-channel structure 120 without inlet shaft 121 , so it also will be less resistance from axial forces, when the process is like in each U-channel structure 120 . The fluid from outlet channels 112 from each of the U-channel structures will then go towards each other, on the inside-, or round the shaft 122 in the outlet channel 112 , whereupon the fluid afterwards will be leaded radial outwards, between the U-channels structures, and further to utilization via own-, or one common channel or pipe. The bearings suspension can be on the shaft 122 with least 2 bearings, which each is placed as near as possible each U-channel structure. And/or at the both inlets openings 103 , can it be arranged a slide-conic-bearings, where it can be of a gas pressure type. The slide bearings at each inlet can at the end be mounted to the end of an anchored pipe/channel, that will be inlet channel 103 which not rotates, and it can be adjustable axially, at on adjustable unit which it is mounted to. This is for an optimum suspended bearing in both of the inlet, and for proper axially placing of the rotary device into said spiral diffusers inlet walls, where it can be little axially margin. At the end of this said inlet channels 103 can the channel/pipe at each inlet, be formed in the same conic shape as the bearings which is mounted on the outside, or the shape is more convergence, and there where it is most narrow inside the inlet channel 103 is the beginning on the rotations device, and where it is a smooth passage forward to the beginning at the sink channels, which also can be divergence from the narrow passage in inlet channel 103 and to the top (near rotation centre) of the sink channel structures 104 . Then can supersonic velocity be attainable, before sink channels 104 , which is favorable for a highest possible static like pressure, when the fluid retards to a normal flow through velocity in the U-channels, which can be relative low in conditions to in-/out flow velocity and the periphery velocity for the fluid. The rotation can be run by the outlet fluid, and when it will be pressed out round the shaft 122 , can it from rise channel 107 nearest shaft, be inside, or after the pass through channel from rise channel 107 to outlet channel 112 be adapted static-, or movable turbine like blades mounted to shaft or U-channel structures outlet side-wall. In this case, must the shaft be connected with the channel-partition-wall 109 . But to get back the most of the tangential-acceleration-force for the fluid in sink channel 104 , with the tangential-retardation-force up rise channel 107 will it therefore be more favorable to let outlet channel 112 be as near the centre of the shaft as possible, and outlet channel can be like as shown in FIG. 1 . The blades in regulations valve 110 can stop further rotation of fluid after the shovel 123 towards the centre of shaft; and further can the regulations valve 110 set its blades in a adapted direction, to get completely or partly rotation force in addition when fluid pass through. When the fluid is pressed further radial from outlet shaft 112 , from the U-channels structures 120 from each end of the shaft, can the radial outlet look like a shovel-turbine, with or without shovel-disks, which is mounted in or on the outlet shaft 122 , with backwards bended shovels in the rotation direction, they can be adjustable, and can then at the same time also act as pressure regulation valve 110 . The shovels can be adapted to give completely or partly rotation force and the fluid can afterwards be pressed outward in to a spiral-diffuser which have adapted direction and is fastened to the evacuated housing. Tightening between spiral diffuser and shaft can be with labyrinth-tightening and when the said shovels/shovel-disk from outlet shaft is adapted to the spiral diffusers opening at right clearance, will it be a under pressure there and to the labyrinth tightening round the shaft, when the fluid has high velocity from turbine through the diffuser-circular-split-opening at the spiral diffuser, and can also make under pressure inside the evacuated housing, when it is moderate tightening between the shafts and diffuser. The shovel turbine can be a commons, or one from each U-channel structures from each side, and in any case must the fluid from each side be hold away from each other by a partition wall, with a conic like tip towards moving direction for the fluid inside the outlet channels 112 and before the shovels turbines inlet. The shovel turbine is essential smaller radius in conditions to the U-channel structure. The evacuated housing can in this case be fastened and tightened between the inlet channels said adjusting unit at each side, in addition is the evacuated housing fastened to said spiral diffuser and is also noise-, shock absorbed and anchored.
[0050] At said suspended bearings can it in said glide bearings at said inlet without shaft, be installed on the outside of inlet channel a lines of labyrinth tightening, where it from the utmost labyrinth circles are a channel that leads to the inlets sides under-pressure side (after narrowing), and when the glide-/cool medium, which can be the current fluid either direct from the inlet or in a own channel, where the fluid will be pressed inside between the bearings-area in adapted amount and pressure, which afterwards will pass the labyrinths circles where the pressure will diminish after them, and the fluid will afterwards be leaded in said channels to the inlets under-pressures side. Similar can be done at all rotating contact areas in the device, where it is suitable and may be with actual fluid-/cool medium which is passing at said contact-/tight area.
[0051] Inlet channels can also be arranged on each side of one disk structure (not shown). Where inlet can be around the shaft ends, or without shaft ends. And instead with conic bearings as said on each side of the disk structure. The inlet channels is connect and branching outwards to each sink channel from each inlet side, and gathers in a common rise channel structure from periphery, where the rise channel structure will be between the two sink channel structures from periphery and to centre of the disk structure, there the rise channel is structure will branching together to each outlet channel in each shaft ends, or the outlet is only in one of the shaft ends. Instead of shaft ends, can it at the same place be an outlet channels/pipes and with shape of diffuser which not rotate, and is in contact with the disc structure at a similar way as said for inlet channels/pipes, but outlet opening have a small circular edge as outlet channel/pipe surrounds with small clearance, in such a way that when the fluid pass at high velocity it will create a under-pressure at the outside of said circular-formed-edge. And if it is a little leakage there, will it be a minor problem. Because the fluid in inlet will take the leakage with outwards sink channels to periphery and inwards in rise channels and out. When it is only one outlet channel at one side, can it on the other side be a similar channel for supply of other substances. Where the supply channels can be more than one and is arranged with pipes in same number as channels, where the innermost pipe is inside next pipe and so on for more pipes, and in the innermost pipe and the interval between the pipes, form the current supply channels, which is coupled further to the respectively channels in the rotation device. If outlet channels is leaded out at both sides, can said innermost pipe be outlet channel, and the interval on outside to next pipe can be inlet channel for cooling medium at one side of the rotation device, and on the other side at similar place is outlet channel for cooling medium. The cool channel pipe can further be surrounded by more pipes for inlet-/outlet channels for more substances as propellant and fluid. Or propellant is adapted mixed with fluid at inlet. Ignition by spark plug can be done as said at outlet, or with said shock pressure from inlet which pressure-ignite as said at periphery, and the sink channel structures on both side of the rise channel structures will cool it down.
[0052] Instead of glide bearings at said inlets, can it instead be mounted super conductive magnets (not shown) at a propitious way, and electric connected and controlled, in such a way that it can run the rotation and be suspended bearings at the same time. Cooling down for super conductive, can be done, or combined with said fluid, if it before said narrowing in inlet channel is cooled down, which after narrowing in inlet can have very low temperature, which dependent on gas type which then the fluid will be. Or it can with addition, or only be used cooled helium for this purpose, and it can be cooled again s through the U-channel structure in own channels, and before expansion at outlet, the helium have to be cooled down so condensing achieves after expanding at outlet. All the disc structure can be surrounded by super conductive magnets, and with space to the said in-/outlet channels/nozzles, and the magnets can execute suspended bearings, rotation, balancing and can at the same time counteract radial and axially forces which act on the disc structure when it rotates and from the processes inside it. Said magnets can also be fits to execute an induction heating towards the periphery at the rotary unit, or this can be executed with a magnetron. The U-channel structure can also at periphery in a adapted area be of a no inductive material, and when the structure-, fluid and other substances inside the channels is completely or partly induction able, can they be heated up directly from the inductions magnets and/or the magnetron.
[0053] The shovels 123 at inlet 103 can be axially outwards and adapted forward-bended in rotation direction in inlet. At outlet 112 can the shovels also be axially outwards, but backwards-bended in rotation direction. It can be least 2 shovels which form a U-channel structure, from nearest possible centre of inlet, via periphery to nearest possible centre of outlet. And it can between them be placed in balance and symmetrical, more and shorter U-channels with various lengths from periphery, there all U-channels have same radial distance. So they are in same circle at periphery. Out at periphery can all the shovels have adapted hole, or channel between U-channels with same substances/fluid, so the substances/fluid in the channels will be even between they in the respectively circular-channels, which then will be formed for each substances/fluid at periphery, which also can lead to said outlet nozzles/valves at periphery.
[0054] Inlet channels for propellant 102 , cooling medium 408 and possibly more channels for supply of more and other substances (not shown), can be leaded from a radial slip chamber which bear against and tight-fitted on outlet shaft 122 , or inlet shaft 121 which each is connected in channels into theirs respectively sink channels. In the slip chambers for each substance, is it inside radial turbines fastened to shaft and connected to said channels where the shovels, which can be regulate able from open to closed, and is forward-bended in rotation direction and will with that achieve a pump effect, in such a way that it's also will form a under pressure inside the slip chamber which also give less pressure and leakage between tightening at shaft. When the shovels are regulate able and at closed position, can it at the same time be a valve that will close for supply of substances to the current slip chambers. Least one of the supplied substances, that is supplied to the rotation device, can also be combined to be a glide-/cooling-medium for said bearings/tight-fitting on the rotating device, and then the said glide-/cooling-medium also be adapted pressurized before the bearings, and after that the glide-/cooling-medium will be leaded inside the rotating device for further use. Or an own glide-/cooling-medium will be used to that purpose in own channels to and from said bearings/tight-fitting on the rotating device.
[0055] The U-channel structure is so far explained and shown in the figures as if the sink- and rise Channels are in 90° on the rotation axis, but they can be mounted with strengthening in a smaller angle as said (stretched more longitudinally axially), for sink- and rise channel structure, or for one of the channel structure. The angel between sink channel structure and rise channel structure will then be larger at periphery.
[0056] The rotating device may also be self-balancing with different systems, and one may be: Two circular round pipes/channels, which each are fitted inside or outside the U-channels structures, outside at respectively inlet- and outlet side, in an adapted circle between rotation axis and periphery, where the pipes/channels is centered on rotations axis. The balancing pipes/channels may be half-filled with a adapted fluid, or half-filled with balancing-balls which can be similar as ball race balls, with less dimension that the cross section of the balance channels. With constant rotation will the balls be spreads in the balance channel, and gradually be placed and will stop in the channel at optimum balance. When unbalance, vibration or similar at rotation will the balancing balls be sets in motion and then it will completely or partly stop said unbalance, vibration or similar in all axis when the balance channels are placed at each side of the U-channel structure, an when it is on condition that the present invention is in the first place at balance in all axis round the rotation axis.
[0057] More U-channel structures can be connected together in a serial link either on same shaft, or only with channels, so the outlets products from one U-channel structure will be pressurized to next U-channel structure and so on. It may also be one or more heat exchangers in the serial link. Said return circulation of fluid and cool medium can be done between one or more link in the serial link, or between the end- and the beginning of the serial link.
[0058] So far is the U-channels structure explained with closed channels, but it can also be open at periphery (not shown), or the utmost part of the U-channel structure 120 form a disk-like chamber that not rotate and is not fastened to the shovels 123 which rotate and is distributed and fastened to each sink channel structure 104 and rise channel structure 107 , which further is fastened to the channel partition disk 109 with shaft 121 , 122 and suspended bearings on stator blade which is fastened to the outer most part of the prevailing and static disk-like chamber with a U-channel structure inside, and with inlet 103 and outlet 112 around shaft ends 121 , 122 , or with other bearings-system as said earlier. Those prevailing inlet shovel wheel 104 and outlet shovel wheel 107 which is fastened to each other, can be formed as said earlier, also outlet regulation valve 110 . On the outside of periphery on the static part of the U-channel structure can least one combustions chamber with a tangentially supply channel for supply of some of the fluid from sink channel structure 104 at adapted amount, and outlet channel from combustion chamber to periphery of rise channel 107 , where combustion outlet channel can be adapted formed with a increased cross section area towards periphery, so the fluid will accelerate to periphery of rise channel structure 107 , and some of the supplied fluid to combustion chamber can surround combustion chamber and its outlet channel in an own channel into periphery of sink channel. Combustion chamber includes propellant nozzle with supply channel for propellant, and ignitions mechanism for combustion of propellant. This U-channel structure device with a static outer housing will involve more friction and turbulence. But the shovel wheel can have higher rotation velocity which can give higher pressure towards periphery, which can compensate for friction and turbulence. With this shape it will be a condition for continuous and a minimum of flow through, to avoid overheating from friction/turbulence even without combustion. Heating can partly be done by said friction at periphery, which will form more expansion in rise channels when the fluid flows through the present invention. Heat exchange channels can be established as a U-channel structure inside the channel partition disk 109 with inlet/outlet as said earlier, and from the heat exchange sink-/rise channel can it be more axially channels with U-form inside the shovels.
[0059] The present invention can also be a heat- or cooling pump when the fluid is gas at outlet, where the pressurized gas will be leaded via a heat exchanger, which remove heat from the gas, which previously will expand trough a turbine or similar, so the gas can be much colder then the surroundings, where the coldness can be utilized. Similarly it can before inlet when the fluid is compressed, also be utilized heat from there via a heat exchanger.
[0060] At periphery of the device, can the fluid/substances expand in many more method as said combustion. As where expansion is a result from heat and for other chemicals, catalyzers, electrochemical reaction or other energy supply is a part of a productions process. Then this productions devices can be arranged at periphery where said reactions are executed inside a disk-like chamber which surround rotation axis, and fluid/substances leads in to the disk-like reaction chamber at its periphery, and pressurized fluid/substances from there will be leaded in channels to outlet from the innermost side towards rotation axis of said reaction chamber, and the pressurized fluid/substances energy utilized further from outlet channel. This current rotation-production-unit can in addition include solutions as said earlier.
[0061] The inventive device may also be a pump for liquid substance and it can with that also be for instance a steam-high-pressure-pump, where for instance water heats from periphery and upward rise channel, then will hot water/steam, which have lower density then cold water in sink channel, make unbalance between they so the water/steam will be high pressed out for utilizing.
[0062] Said rotations devices can be denominates as: Centrifugal-force-Difference Energy (ODE) devices
[0063] The inventive device has to be produced of material with the necessary strength to resist the forces which will arise at high rotation. The structure must have high strength in relation to its density to restrict said forces. The structure can be formed in metal, or from ceramic or composite materials, or nano technology materials, or a combination of these. The centrifugal force determines the rotation velocity and the diameter of the U-channel structure, which is adapted to the force which is tolerated for the used material.
[0064] The figures must be seen as schematic drawings illustrating the principles of the invention only, and not necessarily showing real world physical realizations of the invention. The invention may be realized using many different materials and arrangements of its components. Such realizations should be within the abilities of any person skilled in the art.
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A rotating device for producing pressure from a process substance by expansion, which device includes a U-channel structure ( 120 ) rotatably arranged on an axis ( 121, 122 ) including an expansion point ( 105 ) arranged at the periphery of the rotating device, a sinking channel ( 104 ) for delivery of compressed process substance to said expansion point ( 105 ), a rising channel ( 107 ) for delivery of expanded process substance from said expansion point ( 105 ) to a regulating valve ( 110 ) for delivery of said process substance under high pressure to an outlet channel ( 112 ) for said compressed process substance to an energy recovery device, driving devices in order to rotate said U-channel structure ( 120 ) around the axis ( 121, 122 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 10/356,665, filed Jan. 31, 2003, now U.S. Pat. No. 7,148,030, which claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/353,158, filed Feb. 1, 2002, under 35 U.S.C. § 119(e). The disclosures of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
Proteases constitute a large and important group of enzymes involved in diverse physiological processes such as blood coagulation, inflammation, reproduction, fibrinolysis, and the immune response. Numerous disease states are caused by, and can be characterized by, the alterations in the activity of specific proteases and their inhibitors. The ability to measure these proteases in research or clinically is significant to the investigation, treatment and management of disease states. For example, caspases 3 and 7 are members of the cysteine aspartyl-specific protease (also known as the aspartate specific-cysteine protease, “ASCP”) family and play key effector roles in apoptosis in mammalian cells (Thornberry et al., 1992; Nicholson et al., 1995; Tewari et al., 1995; and Fernandes-Alnemri et al., 1996).
Proteases, however, are not easy to assay with their naturally occurring substrates. Moreover, many currently available synthetic substrates are expensive, insensitive, and nonselective. Furthermore, the use of high concentrations of the target protease, with either the naturally occurring substrate or a synthetic substrate, may be required for the assay, which may result in the self destruction of the protease.
Numerous chromogenic and fluorogenic substrates have been used to measure proteases (Monsees et al., 1994; Monsees et al., 1995) and modified luciferins have provided alternatives to fluorescent indicators (U.S. Pat. Nos. 5,035,999 and 5,098,828). Methods for using modified luciferins with a recognition site for a hydrolase as a pro-substrate were first described by Miska and Geiger (1989). These heterogenous assays were conducted by incubating the modified luciferin with a hydrolase for a specified period of time, then transferring an aliquot of the mixture to a solution containing luciferase. Masuda-Nishimura et al. (2000) reported the use of a single tube (homogenous) assay which employed a galactosidase substrate-modified luciferin. A non-heterogeneous luminescent protease assay has not yet been shown.
While luminescent assays are commonly known for their sensitivity, their performance relative to fluorescent assays is difficult to predict due to fundamental differences in assay formats. Specifically, enzyme-linked luminescence assays yield light coupled to the instantaneous rate of catalysis. In contrast, enzyme-linked fluorescence assays yield light based on the cumulative catalytic activity measured over a period of time (a so-called “endpoint” assay based upon accumulation of fluorophore). By integrating the catalytic activity over a period of time that can extend from hours to days, the light signal from a fluorescent assay can be greatly increased. Similar integration over such long periods is not practical for luminescent assays.
Thus, what is needed is a method to monitor protease activity that is a rapid, single-tube, homogeneous, sensitive assay.
SUMMARY OF THE INVENTION
The invention provides a sensitive luminescent method to detect a protease, e.g., a caspase, trypsin or tryptase. For instance, the invention provides a luminescent assay method to detect one or more caspases. The method comprises contacting a sample suspected of having one or more caspases with a mixture comprising beetle luciferase and an amino-modified beetle aminoluciferin or a carboxy-terminal protected derivative thereof, wherein the amino group of aminoluciferin or the derivative thereof is modified so as to covalently link a substrate for the caspase via a peptide bond to aminoluciferin or the carboxy-terminal protected derivative thereof. If the sample comprises a caspase having a recognition site in the substrate, the substrate is cleaved at the peptide bond that links the substrate to aminoluciferin, yielding aminoluciferin, a substrate for the luciferase, in the mixture. Luminescence is then detected. The method further comprises correlating luminescence with protease concentration or activity, i.e., increased luminescence correlates with increased protease concentration or activity. Preferably, the luminescent assay is more sensitive than a corresponding assay with a conjugate comprising a fluorophore covalently linked via an amide bond to at least one substrate molecule or a functional equivalent thereof. Thus, a conjugate comprising a fluorophore may be covalently linked to one or more molecules of the substrate. In one embodiment of the invention, the luminescent assay is more sensitive than a corresponding assay which employs the fluorophore rhodamine-110, which can be modified via an amide bond to link two protease substrates to the fluorophore.
A “functional equivalent” of a reference substrate is a substrate having one or more amino acid substitutions relative to the sequence of the reference substrate, which functionally equivalent substrate is recognized and cleaved by the same protease at a substantially similar efficiency as the reference substrate. FIG. 13 shows exemplary functionally equivalent substrates for various caspases.
The increased assay sensitivity with methods employing the luminescent substrates of the invention is at least 2 times, more preferably 3, 4, 5, 6, 7, 8, 9, or 10, or even greater, for instance, at least 15, 20, 25, 30, 40, 50, 100, 200, 500, or 1000 times or more, greater than that of an assay employing a conjugate comprising a fluorophore covalently linked to at least one substrate molecule or a functional equivalent thereof. Thus, the methods of the invention may detect less than 5 μU, or less, e.g., less than 1 μU, 0.5 μU or 0.2 μU of caspase in a sample. As used herein, the limit of detection means 3 standard deviations above background noise (“noise” is 1 standard deviation of background and background is a control without caspase).
As described hereinbelow, using a substrate for caspase 3 and 7 that was linked to either aminoluciferin or rhodamine-110, it was found that the limit of detection for the aminoluciferin-based substrate was 0.2 to 0.5 μU of purified caspase while that for the rhodamine-110-based substrate was 10 μU. As also described herein, it was found that the limit of detection of caspase expressing cells with the aminoluciferin-based substrate was 15 cells at 1 hour while the limit of detection for the rhodamine-110-based substrate was 150 cells at 1 hour. Thus, the methods of the invention may be employed with a sample comprising purified or partially-purified preparations of enzyme, as well as a sample comprising a cell lysate or intact cells. Moreover, due to the increased sensitivity of the assay of the invention, accurate background levels of activity, e.g., in resting cells such as those in the absence of inducer or toxin, can be readily and accurately established.
The invention also provides a luminescent assay method to detect a protease that specifically cleaves a substrate comprising aspartate. The method comprises contacting a sample suspected of having one or more aspartate-specific proteases with a mixture comprising luciferase and an amino-modified aminoluciferin or a carboxy-terminal protected derivative thereof, wherein the amino group of aminoluciferin or the derivative thereof is modified so as to covalently link the substrate via a peptide bond to aminoluciferin or a carboxy-terminal protected derivative thereof. If the sample comprises a protease having aspartate as a recognition site, the substrate is cleaved at the peptide bond that links the substrate comprising aspartate to aminoluciferin, yielding aminoluciferin, a substrate for the luciferase in the mixture. Then luminescence is detected in the sample. Preferably, the luminescent assay is more sensitive than a corresponding assay with a conjugate comprising a fluorophore covalently linked to one or more molecules of the substrate or a functional equivalent thereof. Preferred proteases that specifically cleave a substrate comprising aspartate include but are not limited to caspases, e.g., any one of caspases 1-14. Preferred substrates comprise X 1 -X 2 -X 3 -D, (SEQ ID NO:19) wherein X 1 is Y, D, L, V, I, A, W, or P; X 2 is V or E; and X 3 is any amino acid, for instance, a substrate comprising DEVD (SEQ ID NO:1), WEHD (SEQ ID NO:9), VDVAD (SEQ ID NO:4), LEHD (SEQ ID NO:3), VEID (SEQ ID NO:5), VEVD (SEQ ID NO:15), VEHD (SEQ ID NO:11), IETD (SEQ ID NO:6), AEVD (SEQ ID NO:7), LEXD (SEQ ID NO:14), VEXD (SEQ ID NO:16), IEHD (SEQ ID NO:17), or PEHD (SEQ ID NO:18).
The invention also provides a luminescent assay method to detect trypsin or tryptase. The method comprises contacting a sample suspected of having trypsin or tryptase with a mixture comprising luciferase and an amino-modified aminoluciferase or a carboxy-terminal protected derivative thereof, wherein the amino group of aminoluciferin or the derivative thereof is modified so as to covalently link a substrate for trypsin or trytase via a peptide bond to aminoluciferin or a carboxy-terminal protected derivative thereof. Luminescence is then detected. Preferably, the luminescent assay is more sensitive than a corresponding assay with a conjugate comprising a fluorophore covalently linked to at least one substrate molecule or a functional equivalent thereof. For trypsin, arginine and lysine are functionally equivalent substrates as trypsin cleaves the peptide bond after those residues with substantially similar efficiencies. The increased assay sensitivity with methods employing the luminescent substrates of the invention for trypsin or tryptase is at least 2 times, more preferably 3, 4, 5, 6, 7, 8, 9, or 10, or even greater, for instance, at least 15, 20, 25, 30, 40, 50 or 100 times or more, greater than that of an assay employing a conjugate comprising a fluorophore covalently linked to at least one substrate molecule or a functional equivalent thereof. Using a substrate for trypsin, it was found that the limit of detection for a lysyl-aminoluciferin substrate was 3.0 pg while that for the arginine 2 -rhodamine-110-based substrate was 12 to 30 pg. Thus, a trypsin assay which employs an amino-modified aminoluciferin substrate is at least 4 times more sensitive than a corresponding assay with a conjugate comprising rhodamine-110 covalently linked to two functionally equivalent trypsin substrates.
Further provided is a luminescent assay method to detect a protease that specifically cleaves a substrate comprising arginine or lysine. The method comprises contacting a sample suspected of having one or more proteases specific for a substrate comprising arginine or lysine with a mixture comprising luciferase and an amino-modified aminoluciferase or a carboxy-terminal protected derivative thereof covalently linked via a peptide bond to a substrate comprising arginine or lysine. Luminescence in the sample is then detected. Preferably, the assay is more sensitive than a corresponding assay with a conjugate comprising a fluorophore covalently linked to the substrate or a functional equivalent of the substrate. As tryptase is released from activated mast cells in association with inflammatory conditions including allergic reactions such as anaphylactic reactions and allergic rhinitis, and trypsin in stool may be indicative of cystic fibrosis, the methods of the invention may be of diagnostic use, or to monitor a mammal subjected to therapy, e.g., anti-inflammatory therapy.
Also provided is a compound comprising aminoluciferin or a carboxy-terminal protected derivative thereof covalently linked via a peptide bond to a protease recognition site such as a caspase recognition site, a trypsin recognition site, or a tryptase recognition site.
The invention also provides synthetic processes and intermediates disclosed herein, which are useful for preparing compounds of the invention.
Kits useful in the methods of the invention are also envisioned. Such kits may comprise the amino-modified aminoluciferins or carboxy-terminal protected derivatives of the invention, and instructions for their use, optionally a luciferase, for instance a thermostable luciferase and also optionally a buffer for a luminescence reaction which may include a lysing agent.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 depicts relative light units (RLU) for luciferin or aminoluciferin as a substrate for a thermostable firefly luciferase in a luminescent reaction.
Aminoluciferin produces about 60% of the light output as luciferin under saturating conditions. The K m shifts from about 0.6 μM for luciferin to 2 μM for aminoluciferin.
FIG. 2 illustrates the elimination of background signal from free aminoluciferin in a homogeneous assay format. Free aminoluciferin can produce high background signal even in the absence of trypsin. This background signal decreases as the free aminoluciferin is consumed by luciferase. By combining the substrate with luciferase, ATP, and Mg+ prior to the exposure to protease, the signal to noise ratio is dramatically increased. Moreover, the presence of the protease did not interfere with the luciferase reaction.
FIG. 3A shows RLU from a trypsin titration with N-Lys-aminoluciferin over time. Substrate was combined with luciferase, ATP, and Mg+ in buffer and incubated overnight to eliminate free aminoluciferin. The substrate mixture was then added to the trypsin titrations.
FIG. 3B shows RLU (log) from a trypsin titration with N-Lys-aminoluciferin over an extended period of time.
FIG. 4 depicts relative fluorescent units (RFU) from a trypsin titration with Z-Arg-Rho110.
FIG. 5 shows RLU from a caspase titration with Z-DEVD-aminoluciferin over time. Luciferase, ATP, and Mg+ in buffer were added to the substrate.
FIG. 6 shows RFU from a caspase titration with Z-DEVD-Rho110. The fluorescent Z-DEVD-Rho110 substrate was provided in the Apo-ONE™ Homogeneous Caspase 3/7 Assay kit (Promega). The same buffer was used for the DEVD-Rho110 substrate as for the DEVD-aminoluciferin substrate (see FIG. 5 ).
FIG. 7 shows RFU (background subtracted) or RFU (log) for caspase and Z-DEVD-Rho110.
FIG. 8 shows RLU (background subtracted) or RLU (log) for caspase and Z-DEVD-aminoluciferin.
FIG. 9 is a comparison of RLU and RFU for trypsin with N-Lys-aminoluciferin or Z-Arg-Rho110 as a substrate. Trypsin titrations were set up as described above. The luminescent assay was more sensitive than a comparable fluorescent assay, e.g., the Lys-aminoluciferin substrate has a sensitivity 3-10 fold greater than the Arg-Rho110 depending on the time of the reading.
FIG. 10 is a comparison of RLU and RFU for caspase and Z-DEVD-aminoluciferin, Z-DEVD-AMC or Z-DEVD-Rho110 as a substrate. The Z-DEVD-Rho110 substrate and buffer used were the Apo-ONE™ (Promega) substrate and buffer. The same buffer was used for the DEVD-AMC substrate. The DEVD-aminoluciferin substrate had a sensitivity 50-300 fold greater than the Arg-Rho110 depending on the time of the readings.
FIG. 11 shows RLU or RFU obtained with Jurkat cells (induced or uninduced) and the caspase substrate Z-DEVD-aminoluciferin or Z-DEVD-Rho110. The Apo-ONE™ buffer and Z-DEVD-Rho110 substrate were used for the fluorescent caspase assay. The same buffer was used for the DEVD-aminoluciferin substrate with the addition of luciferase, ATP, and MgSO 4 . The DEVD-aminoluciferin substrate has a sensitivity 10-fold greater than the Arg-Rho110 at the 1 hour time point. At 4 hours, this decreased to about 2-fold.
FIG. 12 shows relative RLU or RFU results obtained using CHAPS or Apo-ONE™ buffer.
FIG. 13 illustrates recognition sites for various caspases (SEQ ID NO: 1-18; Thornberry et al., 1997; Garcia-Calvo et al., 1999).
DETAILED DESCRIPTION OF THE INVENTION
Rapid and sensitive assays of proteolytic activity are important for general characterization of proteases and high-throughput screening for protease inhibitors. However, the inherent background of fluorescence, particularly in cell-based systems, can limit assay sensitivity. Moreover, to achieve maximum sensitivity, lengthy incubations are often required for accumulating the fluorescent assay product. Luminescent assays can often provide greater sensitivity in less time.
Thus, the present invention provides an improved, sensitive method for monitoring protease activity in purified preparations comprising the protease, in cell lysates or cells, either prokaryotic or eukaryotic cells. Preferred eukaryotic cells include mammalian cells, for example, human, feline, bovine, canine, caprine, ovine, swine, equine, non-human primate, e.g., simian, avian, plant or insect cells.
The cells may be cells that have not been genetically modified via recombinant techniques (nonrecombinant cells), or recombinant cells, the genome of which is augmented with a recombinant DNA. The DNA may encode a protease to be detected by the methods of the invention, a molecule which alters the level or activity of the protease in the cell, and/or a molecule unrelated to the protease or molecules that alter the level or activity of the protease.
The protease is detected using an amino-modified aminoluciferin or a carboxy-terminal protected derivative thereof, which modification comprises a substrate for the protease. The substrate, which comprises one or more amino acid residues which include the recognition site for the protease, is covalently linked to the amino group of aminoluciferin or the carboxy-terminal modified derivative via a peptide bond. Preferably, the N-terminus of the substrate is modified to prevent degradation by aminopeptidases, e.g., using an amino-terminal protecting group.
In the absence of the appropriate enzyme, a mixture comprising a substrate and luciferase will generate minimal light as minimal aminoluciferin is present (a small amount of light may be generated due to spontaneous hydrolysis of the peptide bond). In the presence of the appropriate enzyme, the peptide bond linking the substrate and aminoluciferin (the bond immediately adjacent to the 6′ position on the luciferin core molecule) can be cleaved by the protease to yield aminoluciferin, a substrate for luciferase. Thus, in the presence of luciferase, for instance, a native, a recombinant or a mutant luciferase, light is generated, which is proportional to the amount or activity of the protease. Any beetle luciferase, preferably a thermostable luciferase, may be employed in the methods of the invention.
The aminoluciferin-based substrates of the invention are relatively inexpensive to synthesize and can be purified to high levels. Moreover, because they are extremely sensitive substrates, only very small amounts of a biological sample (e.g., cells, and physiological fluids, blood, urine, etc., which comprise cells) are required to perform the assay. Further, because the aminoluciferin-based substrates are extremely selective, little or no purification of the biological sample is required. For example, using such an assay, the activity of caspase 3, caspase 7 and trypsin was found to be below the level of detection of a corresponding assay using a Rhodamine-110 caspase substrate (Rhodamine-110 is likely one of the most sensitive indicators known). In particular, the sensitivity described herein for a caspase is superior to Apo-ONE™ (Promega, Madison, Wis.). Apo-ONE™ is a fluorescent based assay, which uses the fluorphore Rhodamine-110 conjugated to 2 recognition sequences for caspase 3/7.
Preferably, the methods of the invention are employed as a homogeneous assay for a protease, such as a caspase, tryptase or trypsin, i.e., the modified aminoluciferin, luciferase and additional components are mixed prior to adding the mixture to the sample. Results may be read without additional transfer of reagents.
A specific compound of the invention is a compound of formula (I):
wherein R is a peptide that is a substrate for caspase, trypsin and tryptase, which is linked to the remainder of the compound of formula (I) through its C-terminus forming a peptide (amide) bond; and R′ is H or a suitable carboxy protecting group (e.g. a (C 1 -C 6 )alkyl, phenyl or benzyl ester), or a suitable salt thereof.
Another specific compound of the invention is a compound of formula (I):
wherein R is a peptide that is linked to the remainder of the compound of formula (I) through an aspartate, lysine, or arginine group at the C-terminus of the peptide forming a peptide (amide) bond; and R′ is H or a suitable carboxy protecting group (e.g. a (C 1 -C 6 )alkyl, phenyl or benzyl ester), or a suitable salt thereof.
It will be appreciated that salts of the amino-modified aminoluciferin compounds or the carboxy-terminal protected derivatives thereof can also be used in the methods described herein, and also form part of the invention. Methods for preparing suitable salts are known in the art.
Compounds of the invention can be prepared using procedures that are generally known, or they can be prepared using the procedures described herein. For example, compounds of the invention can be prepared using standard solution phase chemistry. Accordingly, a peptide can be coupled to an amino-cyanobenzothiazole, followed by reaction with D-cysteine to provide a compound of the invention. Alternatively, amino-cyanobenzothiazole can first be reacted with D-cysteine to provide an intermediate amino compound, which can subsequently be conjugated to a peptide to provide a compound of the invention.
Compounds of the invention can also be prepared using conventional solid-phase peptide synthesis techniques. For example, an aminoluciferin labeling reagent in the form of an N-protected amino acid that is attached to a peptide synthesis resin via the carboxylic acid function, can be prepared using standard coupling reagents (e.g., EDAC, DCC, or HOBt). The N-protective group is preferably Fmoc or t-Boc, but can be any group that can be removed without deleterious effect on the chemical bond connecting the label to the resin. Once attached to the resin the N-protective group is removed and the peptide is built onto the N-terminus of the resin-bound label using standard peptide synthesis protocols. At the end of peptide synthesis the labeled peptide is cleaved from the resin using standard cleavage reagents to provide the carboxylic acid.
Accordingly, the invention provides aminoluciferin coupled via the free carboxyl group to a solid support for the purposes of peptide synthesis. Such a carboxy-terminal protected aminoluciferin is convenient for the synthesis of a conjugate comprising a peptide of interest conjugated to the amino group of aminoluciferin. Preferably, the amino group is protected with an Fmoc or a t-Boc group.
The invention also provides a method for preparing a compound of the invention comprising forming an amide bond between the amino group of a solid support bound aminoluciferin and a first amino acid or a first peptide; and optionally attaching one or more additional amino acids or peptides through peptide bonds to provide the compound. The solid support bound aminoluciferin can optionally be prepared by attaching an N-protected aminoluciferin to a solid support through the carboxy group; and deprotecting the aminoluciferin. The support bound compound can then be removed to provide the corresponding free carboxylic acid, which can optionally be protected to provide a carboxyterminal protected derivative.
A carboxy-protected derivative of the invention can be prepared from the corresponding carboxylic acid using standard techniques. Accordingly, the invention provides a method to prepare a carboxy-terminal protected derivative of aminoluciferin, comprising protecting the corresponding acid with a suitable carboxy-protecting group.
Suitable amino protecting groups (e.g. Fmoc or t-Boc), as well as suitable carboxy protecting groups (e.g. (C 1 -C 6 )alkyl, phenyl or benzyl esters or amides) that can be incorporated into the compounds of the invention, are well known to those skilled in the art (See for example, T. W. Greene, Protecting Groups In Organic Synthesis ; Wiley: New York, 1981, and references cited therein).
The invention will be further described by the following non-limiting examples.
EXAMPLE 1
To compare the limit of detection for a luminescence-based and a fluorescence-based assay for trypsin, two substrates, Lys-aminoluciferin (Cbz-modified lysinyl-aminoluciferin) and Arg-Rho-110 (Molecular Probes, Catalog no. R6501), were used. Substrate was resuspended in 100 mM Hepes, pH 7.9, at a concentration of 10 mM and stored at −20° C. The thawed Lys-aminoluciferin substrate, thermostable luciferase (5.2 mg/ml stock), and ATP (0.1 M stock) were diluted in buffer (50 mM HEPES, pH 7.9, 10 mM MgSO 4 , 1 mM EDTA, pH 8.2 and 0.1% prionex) to make a stock that was 10× the final concentration. The 10× stock was 200 μM Lys-aminoluciferin, 200 μg/ml luciferase, and 2.0 mM ATP. This 10× stock was incubated for at least 90 minutes to eliminate any free aminoluciferin.
Trypsin was prepared for titration as follows: 1 μg/μl stock solution was diluted to 10 ng/50 μl in the same buffer as above (50 mM HEPES, pH 7.9, 10 mM MgSO 4 , 1 mM EDTA, pH 8.2 and 0.1% prionex). This 10 ng/μl trypsin solution was serially diluted 5 fold to 2 ng, 0.4 ng, 0.08 ng, 0.016 ng, 3.2 pg, 0.64 pg, 0.128 pg, 0.0256 pg and 0.005 pg. The trypsin dilutions were added to two 96-well plates in replicates of 8 at 50 μl per well. Pipette tips were changed for each row to avoid enzyme carryover. Two columns (16 wells) contained buffer only without trypsin.
One of the two plates of the trypsin dilutions was then used to test the Lys-aminoluciferin substrate ( FIG. 3 ). Samples were tested in quadruplicate. The 10× substrate/luciferase/ATP mix was further diluted 5 fold in the above-described buffer to make a 2× stock. 50 μl of this 2× stock was added to each well containing 50 μl of the trypsin titration such that the final 100 μl volume contained 20 μM Lys-aminoluciferin, 200 μM ATP, and 20 μg/ml of thermostable luciferase in buffer (50 mM HEPES, pH 7.9, 10 mM MgSO 4 , 1 mM EDTA, pH 8.2 and 0.1% prionex). The substrate mix was also added to 12 of the 16 wells containing buffer only without trypsin. The remaining 4 wells were left with buffer only (no substrate mix). This plate was incubated at room temperature and read by luminometer at 45 minutes and 3 hours after adding the substrate mix to the trypsin.
The second plate of trypsin dilutions was used to test the Arg-Rho-110 substrate ( FIG. 4 ). The Arg-Rho-110 substrate was tested at final concentrations of 10 μM and 2.5 μM. 2× stocks of 20 μM and 5 μM were prepared by diluting the substrate in 50 mM HEPES, pH 7.9, 10 mM MgSO 4 , 1 mM EDTA, pH 8.2 and 0.1% prionex. To each well of the plate containing 50 μl of the trypsin titration was added 50 μl of either the 20 μM or 5 μM 2× stocks of Arg-Rho-110 substrate. The 20 μM stock was added to the first four rows (final concentration of 10 μM in rows A-D) and the 5 μM stock was added to the second four rows (final concentration of 2.5 μM in rows E-H). The substrate mix was also added to 12 of the 16 wells containing buffer only without trypsin. The remaining 4 wells were left with buffer only (no substrate mix). The Arg-Rho-110 plate was incubated at room temperature in the dark for 4.5 hours and read on a fluorimeter.
The signal to noise was calculated as signal-background (no trypsin)/S.D. of background. The limit of detection was determined as 3 S.D. above background noise.
Results
A homogeneous format was used for a trypsin assay. The results indicated that the limit of detection using the Lys-aminoluciferin substrate for trypsin is lower than the Arg-Rho-110 substrate. In particular, the Lys-aminoluciferin substrate has a sensitivity 3 to 10 fold greater depending on the time of the reading than the Arg-Rho-110 substrate ( FIG. 9 ). Moreover, the luminescent assay reached a maximum sensitivity in 30 minutes or less and was very stable for extended time periods.
EXAMPLE 2
To determine the effect of an overnight pre-incubation of substrate with luciferase, ATP and buffer prior to adding trypsin, a substrate/luciferase/ATP mix was incubated overnight in the dark, at room temperature. For the Lys-aminoluciferin substrate, the thawed Lys-aminoluciferin substrate (10 mM stock), thermostable luciferase (5.2 mg/ml stock), and ATP (0.1 M stock) were diluted in buffer (50 mM HEPES, pH 7.9, 10 mM MgSO 4 , 1 mM EDTA, pH 8.2 and 0.1% prionex) to make a stock that was 10× the final concentration. The 10× stock was 200 μM Lys-aminoluciferin, 200 μg/ml luciferase, and 2.0 mM ATP. After overnight incubation, the 10× stock was diluted in buffer to make a 2× stock (40 μM of substrate, 400 μM of ATP and 40 μg/ml of luciferase). The Arg-Rho-110 substrate was also prepared to a 2× working stock concentration of 40 μM from a 5 mM stock.
Trypsin dilutions were prepared from a 1 μg/μl stock and diluted to the same concentrations as in Example 1, and two different plates were set up with 4 wells for each concentration of trypsin, 50 μl per well. Two columns had buffer only without trypsin as a control. Then, 50 μl of the 2× Lys-aminoluciferin substrate mix was added to each well of one plate, and the results were read at several time points on a luminometer. To the second plate, 50 μl of the 2× Arg-Rho-110 stock was added to each well for a final concentration of 20 μM, as in Example 1.
The luminescence-based assay was able to detect as little as 3.0 pg of trypsin, while the fluorescence-based assay had a limit of detection of about 12-30 pg (4-10 times less enzyme).
EXAMPLE 3
To conduct a direct comparison between luminescent and fluorescent substrates for caspase 3, DEVD-Rho-110 and DEVD-aminoluciferin were employed. The DEVD-aminoluciferin substrate/luciferase/ATP mixture was prepared first and preincubated prior to the enzyme assay to eliminate free aminoluciferin. To 1.25 ml of Apo-ONE™ buffer (Promega) was added 10 μl of DEVD-luciferin (10 mM stock), 10 μl of ATP (0.1 M stock), 50 μl of MgSO 4 (1 M stock), 50 μl of prionex (10% stock), and 48 μl of luciferase (5.2 mg/ml stock). The volume was brought up to 2.5 ml with nanopure, autoclaved water to make a 2× stock of 40 μM DEVD-luciferin, 400 μM ATP, 0.2% prionex, and 100 μg/ml luciferase. This stock was incubated overnight at room temperature.
Caspase (Upstate Biotech, Cat. No. 14-264; approximately 10 mU/ng protein with >75% in active conformation) was diluted 550 fold in a 50/50 mixture of Apo-ONE™ buffer/RPMI-1640 culture media, from 1 U/μl to 1.8 mU/μl. 50 μl of Apo-One™ buffer/RPMI-1640 media was added to each well in two 96-well plates. Then, 5.5 μl of the caspase stock was added to the 50 μl of Apo-One™ buffer/RPMI-1640 media for a concentration of about 10 mU/50 μl. Ten serial dilutions of 10 fold each were carried out in the wells by serially transferring 5.5 μl of caspase solution into the 50 μl of the buffer/media mix. The final caspase concentrations were 10 mU, 1 mU, 0.1 mU, 0.01 mU, 0.001 mU, 0.1 μU, 0.01 μU, 0.001 μU, 0.1 nU, and 0.01 nU/well. The last two columns were buffer/media only without caspase.
To one plate of caspase dilutions, 50 μl of the DEVD-aminoluciferin substrate mixture was added to each well for final concentrations of 20 μM DEVD-aminoluciferin, 200 μM ATP, 10 mM MgSO 4 , 0.1% prionex, and 50 μg/ml luciferase. To the other plate, 50 μl of the DEVD-Rho-110 substrate was added to each well at the recommended final concentration of 50 μM. Readings were taken for each plate at 1 hour, 3 hours, and 5 hours on a luminometer and fluorimeter, respectively.
Signal to noise was calculated as above and the limit of detection was determined as 3 S.D. above the background noise.
As in the case of the trypsin-substrate modified luciferin, DEVD-aminoluciferin was 10-100 times more sensitive than DEVD-Rho-110 ( FIG. 10 ). The fluorescent ratio assay required several hours for maximum sensitivity and was always changing over time. Moreover, the fluorescent assay lost linearity at low caspase concentrations.
The luminescent assay is a rate assay that is not dependent on the accumulation of cleaved substrate. Therefore, steady-state (protease cleavage versus luciferase consumption of aminoluciferin) is reached rapidly and this steady-state is stable for several hours. Moreover, linearity is also maintained for several hours. The luminescent assay reached a maximum sensitivity in 30 minutes or less and was very stable for extended time periods. The luminescent assay was linear over 3-4 logs at low caspase concentration ( FIG. 8 ).
EXAMPLE 4
The DEVD-aminoluciferin caspase substrate and the DEVD-Rho-110 caspase substrate were used to measure caspase activity in Jurkat cells induced to undergo apoptosis with anti-FAS antibody. DEVD-luciferin and luciferase were prepared for pre-incubation prior to use in the assay. Substrate, ATP, MgSO 4 , prionex and luciferase were diluted from the same stock as in Example 3 to the same 2× concentration, except that the components were diluted in autoclaved water rather than Apo-ONE™. This mixture was incubated overnight in the dark (covered in foil).
The next day, Jurkat cells, grown in RPMI-1640 media with 10% Fetal Bovine Serum (FBS) to a density of 5×10 5 cells/ml, were treated with anti-FAS antibody. To one vial of 8 ml of media was added 1.6 μl of antibody (1:5000 dilution); a second vial contained 8 ml of media and no antibody. Cells were incubated for 4 hours at 37° C., in 5% CO 2 . Cells were then centrifuged and resuspended in 12.5 ml of RPMI-1640 to a density of 3.2×10 5 cells/ml, then diluted 1:1 with Apo-ONE™ buffer for 1.6×10 5 cells/ml, or 8,000 per 50 μl.
Two 96-well plates were prepared such that on each, the first column was left empty, and 50 μl of RPMI-1640:Apo-ONE™ solution was placed in each of the remaining wells. To the first four rows of each plate, 100 μl of the “induced” cell solution (8,000 cells) was added and the cells then serially diluted from 8,000 cells/well, to 4,000 cells/well and so on, down to 7.8 cells/well. The twelfth column was left without cells and with only 50 μl of RPMI-1640:Apo-ONE™ solution. The next four rows on each plate were likewise treated with 100 μl of the “uninduced” cell solution, and then likewise serially diluted to 7.8 cells/well. Again, the last column of those four rows was left with media alone (no cells).
Signal to noise was calculated (signal minus background (no cell control)/S.D. of background) and the limit of detection was determined as 3 S.D. above the background noise.
One of the two plates was treated with 50 μl of either DEVD-aminoluciferin/luciferase mix or with DEVD-Rho-110/Apo-ONE™ (Promega G778B and G777B). Each plate was mixed on a plate shaker for 30 seconds then incubated at room temperature and read on either a Dynex luminometer or Fluoroskan plate reader at 1 hour, 2 hours, 4 hours and one day later.
The aminoluciferin substrate assay showed that the assay detects caspase positive cells in a well having 15 cells in as little as 1 hour, and that the assay remains linear at the 4 hour time point ( FIG. 11 ). On the other hand, the DEVD-Rho-110 substrate assay had a limit of detection of 150 cells/well at 1 hour, and about 30 cells at 4 hours.
EXAMPLE 5
To evaluate different assay component formulations for caspase-3 activity and to compare sensitivities of DEVD-aminoluciferin to DEVD-Rho-110 in those formulations, two stock solutions were prepared. As above, the DEVD-aminoluciferin/luciferase mixture is prepared and allowed to incubate overnight. One stock solution included a 1% solution of CHAPS buffer (Sigma, Catalog No. C-5070) and the other a 1% solution of Thesit (Pragmatics, Inc., Catalog No. S-22#9). The buffer formulations were as follows: 100 μl of HEPES (1 M stock, 50 mM final concentration), 10 μl of CaCl 2 (1 M stock, 5 mM final concentration), 30 μl of MgSO 4 (1 M stock, 15 mM final concentration), 8 μl of ATP (0.1 M stock, 400 μM final concentration), 8 μl of DEVD-aminoluciferin (10 mM stock, 40 μM final concentration), 38.4 μl of luciferase (5.2 mg/ml stock, 100 μg/ml final concentration) and 20 μl of prionex (10% stock, 0.1% final concentration) were combined in each of 2 tubes. Finally, 200 μl of either CHAPS or Thesit (1% stock, 0.1% final concentration) was added to one of the tubes. This was incubated overnight. The next day, 40 μl of DTT (Promega, catalog no. V3151) (1 M stock, 20 mM final concentration) was added to each tube (CHAPS and Thesit). Finally, 1545.6 μl of pure, autoclaved water was added for a final volume of 2 ml per solution.
Caspase (Upstate Biotech, Cat. No. 14-264) was diluted from 1 U/μ1 stock to 1 mU per 50 μl, or 8 mU in 400 μl of buffer (see below). The caspase buffer was as follows: HEPES, CHAPS or Thesit, CaCl 2 , MgSO 4 , DTT and prionex, all in the same final concentrations as described above. The caspase was serially diluted by factors of 10, from 1 mU through 1×10 −8 mU to a final volume of 440 μl of each dilution. 50 μl of each of these dilute caspase solutions were added to each of 3 wells on each of two 96 well plates. Three columns of wells were left blank.
To one plate, 50 μl of DEVD-aminoluciferin/luciferase was added to each of the 6 wells containing each dilution (both CHAPS and Thesit treated). To the second plate, 50 μl of DEVD-Rho-110 substrate was added to each of the 6 wells containing each dilution (both CHAPS and Thesit treated). The plates were read at various times on a luminometer (Dynex) or a fluorimeter (Fluoroskan).
The limit of detection for the aminoluciferin was in the range of 0.2 μU of caspase in buffer containing either CHAPS or Thesit ( FIG. 12 ). On the other hand, the limit of detection using the rhodamine-based substrate was 2-6 μU (a factor of 10-30).
EXAMPLE 6
Representative compounds of the invention were prepared according to the following non-limiting examples.
General Synthetic Procedures
All reactions were run under positive pressure of dry nitrogen gas. Reactions requiring anhydrous conditions were performed in oven-dried glassware that was cooled under nitrogen gas or a dessicator. Anhydrous solvents and reagent solutions were transferred using oven-dried syringes. Tetrahydrofuran (THF), dichloromethane, pyridine, acetonitrile, and dimethylformamide (DMF) were obtained as anhydrous solvent and were used without further purification. Reagent grade solvents were used for chromatography without further purification.
TLC was performed on 0.2 mm EM Science precoated silica gel 60 F 254 TLC plates (5×20 cm aluminum sheets). Flash chromatography was performed using Selecto Scientific 32-63 μm silica gel (60 F 254 ).
Analytical Reverse-phase HPLC was performed using a Synergi 4μ Max-RP column, 4.6 mm×50 mm, on Beckman System Gold 126 pump systems equipped with a Model 168 diode-array detector and Model 507 autosampler. The solvents were: A—10 mM sodium phosphate buffer (pH 7.0) and B—methanol. All analytical reverse-phase chromatograms were monitored at 254 nm and 315 nm.
ESI Mass spectra were recorded on a FISONS VG Platform Electrospray Mass Spectrometer. The NMR spectra of all the compounds conformed to their respective structures.
Nmr spectra were obtained on a Varian 300 Mhz spectrometer.
EXAMPLE 7
Preparation of N-(Z-DEVD)-aminoluciferin
To a 25 mL flask containing N-[Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)]-aminoluciferin (20 mg, 0.019 mmol) was added 2 mL of a solution of 20% trifluoroacetic acid in dichloromethane. The reaction mixture was stirred at room temperature for 4 h. HPLC indicated the reaction was progressing slowly. Additional trifluoroacetic acid was added to make a 30% solution of trifluoroacetic acid in the reaction mixture and the reaction was left standing in a 5° C. refrigerator overnight. The next day HPLC analysis indicated the reaction was complete. The reaction mixture was concentrated to a creamy solid residue. The crude product was purified by HPLC chromatography on a Synergi 4 u Max-RP semi-preparative column using 20 mM ammonium acetate buffer (pH 6.5) and methanol. Fractions containing product were pooled and lyophilized to afford 10.3 mg (62%) of N-(Z-Asp-Glu-Val-Asp)-aminoluciferin as an off-white powder.
The intermediate N-[Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)]-aminoluciferin was prepared as follows.
a. Synthesis of Asp(OtBu)-OH. Fmoc-Asp(OtBu)-OH (500 mg, 1.2 mmole) was dissolved in a 9:1 mixture of dichloromethane-piperidine (5 mL) in a 25 mL round-bottomed flask. The reaction mixture was stirred overnight at room temperature. The next morning, TLC analysis indicated complete Fmoc deprotection. The reaction mixture was concentrated by rotoevaporation, coevaporated 2 times with toluene, and dried under vacuum to give a crude oil. This oil was purified by flash chromatography on silica gel (50 g) using a stepwise solvent gradient of 10%-50% methanol in dichloromethane to afford 250 mg (100%) of Asp(OtBu)-OH. b. Synthesis of Fmoc-Val-Asp(OtBu)-OH. Asp(OtBu)-OH (250mg, 1.3 mmol) was dissolved in 40 mL of a 1:1 mixture of dichloromethane and pyridine in a 100 mL round-bottomed flask with magnetic stirring. To this solution was added Fmoc-Val-OSu (690 mg, 1.58 mmole) and stirring continued overnight under nitrogen atmosphere at ambient temperature. The next morning the reaction was concentrated by rotoevaporation to a pale yellow oil, which was dissolved in dichloromethane and washed twice with 10% aqueous citric acid solution. The aqueous layer was extracted again with dichloromethane, and the combined organic layer was dried with anhydrous sodium sulfate and concentrated by rotoevaporation to give 820 mg of crude white foam. This material was purified by flash chromatography on silica gel using a step-wise solvent gradient of 3%-20% methanol in dichloromethane to afford 250 mg (38%) of Fmoc-Val-Asp(OtBu)-OH as an off-white solid. c. Synthesis of Val-Asp(OtBu)-OH. Fmoc-Val-Asp(OtBu)-OH (250 mg, 0.57 mmole) was dissolved in 10 mL of a 9:1 mixture of piperidine-dichloromethane in a 50 mL round-bottomed flask, and the reaction mixture was allowed to stand at ambient temperature. After 1 h TLC analysis indicated the reaction was complete. The reaction mixture was concentrated, coevaporated twice with 20 mL of toluene, and dried under vacuum to provide 250 mg of a crude white residue. This residue was purified by flash chromatography on silica gel (25 g) using a step-wise solvent gradient of 20%-75% methanol in dichloromethane to afford 120 mg (76%) of pure Val-Asp(OtBu)-OH. d. Synthesis of Z-Asp(OtBu)-Glu(OtBu)-OH. To a stirred suspension of Glu(OtBu)-OH in dichloromethane (5 mL) and pyridine (3 mL) in a 25 mL round-bottomed flask was added Z-Asp(OtBu)-Osu (530 mg, 1.26 mmol). The resulting mixture was stirred at room temperature for two days. The reaction mixture was concentrated by rotoevaporation and the residue was partitioned between ethyl acetate and 10% aqueous citric acid solution. The aqueous phase was extracted three times with ethyl acetate. Combined extracts were dried over sodium sulfate and concentrated by rotoevaporation to give a crude oil that was purified by flash chromatography on silica gel (75 g) using a stepwise solvent gradient of 2%-4% methanol in dichloromethane. Fractions containing product were pooled and concentrated by rotoevaporation to give 630 mg (98%) of Z-Asp(OtBu)-Glu(OtBu)-OH as an off-white solid foam. e. Synthesis of ZAsp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)-OH. To a stirred solution of Z-Asp(OtBu)-Glu(OtBu)-OH (245 mg, 0.48 mmol) in dichloromethane (20 mL) in a 100 mL round-bottomed flask was added N-hydroxysuccinimide (60.9 mg, 0.53 mmole) followed by dicyclohexylcarbodiimide (109.2 mg., 0.53 mmol), and the resulting cloudy mixture was allowed to stir for 1 h at ambient temperature under nitrogen atmosphere. After TLC analysis showed the reaction was complete, the dicyclohexylurea precipitate was removed by filtration and the filtrate was concentrated by rotoevaporation to about 7 mL, at which point some precipitation began to occur. This mixture was added to a stirred solution of Asp(OtBu)-Val-OH (120 mg., 0.437 mmol) in DMF (20 mL) in a 50 mL round-bottomed flask. After the reaction was stirred 2 h at ambient temperature, TLC analysis indicated the reaction was proceeding slowly, and the hazy mixture was then concentrated to about 15 mL and stirring was continued overnight. The next morning, TLC analysis showed the reaction was not yet complete. The reaction flask was fitted with a condenser and the mixture was then heated at 35-38° C. using a water bath for 1.5 h, during which time the mixture clarified somewhat. The reaction was cooled and concentrated by rotoevaporation to a residue, which was suspended in ethyl acetate (50 mL) and washed twice with 10 mL of 10% aqueous citric acid solution. The organic layer was then washed twice with 10 mL of water, and the water layer was back-extracted with ethyl acetate. The organic layers were combined, dried over anhydrous sodium sulfate, concentrated by rotoevaporation, and coevaporated twice with dichloromethane to afford 500 mg of crude off-white foam. This crude material was purified by flash chromatography on silica gel (25 g) using a step-wise solvent gradient of 5%-20% methanol in dichloromethane to provide 190 mg (56%) of Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)-OH as an off-white foam. f. Synthesis of 6-(Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)-amino-2-cyanobenzothiazole. To a stirred solution of of Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)-OH (95 mg, 0.112 mmol) in THF (5 mL) cooled in -10° C. bath (sodium chloride-ice) was added via syringe N-methylmorpholine (13.4 μL, 0.122 mmol) and then isobutyl chloroformate (16 μL, 0.122 mmol). The reaction mixture was stirred at −10° C. for 1h and then a solution of 6-amino-2-cyanobenzothiazole (27.9 mg, 0.159 mmol) in THF (2 mL) was added via pipet. The cooling bath was removed and the reaction mixture was allowed to warm to room temperature and stir for 2 days. TLC analysis indicated a new product was generated. The reaction mixture was concentrated by rotoevaporation to give a crude residue that was dissolved in ethyl acetate and washed twice with water. The aqueous phase was extracted again with ethyl acetate. Combined extracts were dried and concentrated to give 104 mg of crude yellow residue that was purifies by flash chromatography on silica gel (10 g) using a stepwise solvent gradient of 4%-7% acetone in dichloromethane to provide 44 mg (42%) of 6-(Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)-amino-2-cyanobenzothiazole as a yellow solid. g. Synthesis of N-[Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)]-aminoluciferin. To a 50 mL round-bottomed flask was added D-cysteine hydrochloride (997 mg, 5.68 mmol) and deionized water (14 mL, degassed with bubbling nitrogen for 15 min). The resulting mixture was magnetically stirred under nitrogen atmosphere until dissolution was achieved. To a separate 25 mL erlenmeyer flask was added anhydrous potassium carbonate (785 mg, 5.68 mmol) and degassed deionized water (14 mL). The resulting solution was added in portions via pasteur pipet to the flask containing the D-cysteine solution, with periodic addition of 6N hydrochloric acid as needed to maintain a pH less than 7.0. After addition of the potassium carbonate solution to the reaction flask was complete, a portion of the reaction mixture (0.24 mL, containing approximately 0.047 mmoles of D-cysteine) was measured (via pipet) and transferred to a separate 5 mL reaction vial. A solution of 6-(Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)-amino-2-cyanobenzothiazole (44 mg, 0.047) in methanol (1 mL) was then added to the 5 mL reaction vial, followed by addition of 0.1 M hydrochloric acid solution as needed to maintain the pH below 7.0. The reaction mixture was stirred at room temperature overnight. HPLC and TLC analysis indicated consumption of starting materials. The reaction mixture was concentrated by rotoevaporation and coevaporated with acetonitrile to give a solid residue. The crude product was chromatographed on silica gel (10 g) using a stepwise solvent gradient of 10%-12% methanol in dichloromethane to afford 20 mg (41%) of N-[Z-Asp(OtBu)-Glu(OtBu)-Val-Asp(OtBu)]-aminoluciferin as an off-white solid.
EXAMPLE 8
Preparation of racemic N-Fmoc-aminoluciferin
2- [6′-(9-fluorenylmethoxycarbonyl)amino-2′-benzothiazolyl]-Δ 2 -thiazoline-4-carboxylic acid (N-Fmoc-aminoluciferin). To a 100 mL round-bottomed flask were added N-trifluoroacetyl-aminoluciferin (660 mg, 1.76 mmol) and a solution of methanolic ammonia (30 mL of a 7 M solution, 210 mmol). The resulting mixture was left standing at room temperature for 4 days. The reaction mixture was concentrated by rotoevaporation and then coevaporated with dichloromethane to give 626 mg of a crude brown solid residue that was used in the next step without purification. A portion of the crude brown solid residue (391 mg) was dissolved in methanol (40 mL) and water (2 mL) in a 100 mL round-bottomed flask. To this solution was added Fmoc-Cl (435 mg, 1.68 mmol) and the reaction mixture was stirred at room temperature for 2 h. The reaction mixture was concentrated by rotoevaporation and coevaporated with acetonitrile and then dichloromethane to afford a brown foam after drying under vacuum. The product was purified by flash chromatography on 3 successive silica gel columns using 100 g for the first 2 columns and 150 g for the third. The eluting solvent for the first column was 98:2 dichloromethane-methanol. The eluting solvent for the second column was 93:7 dichloromethane-methanol. The eluting solvent for the third column was 97:3 dichloromethane-methanol. Fractions containing product were combined and concentrated to provide 280 mg of waxy product that was 95% pure and 320 mg of product that was 89% pure. The 280 mg of waxy material was re-purified on 25 g of silica gel using 4:1 dichloromethane-methanol to give 108 mg of dry pale yellow solid. The 320 mg portion of product was combined with 230 mg of material recovered from combined impure fractions from the 3 columns described above. This combined material (550 mg) was re-purified by flash chromatography on silica gel (50 g) using 78:22 dichloromethane-methanol to afford 223 mg of product. Total product thus obtained was 380 mg of amber solid that was 95% pure by HPLC analysis. MS (ESI − ) m/z 500 (M-H) − , 456 (M—H—CO 2 ) − .
The intermediate compound N-trifluoroacetyl-aminoluciferin was prepared as follows.
a. Preparation of 2-(6′-Trifluoroacetylamino-2′-benzothiazolyl)-Δ 2 -thiazoline-4-carboxylic acid (N-Trifluoroacetyl-aminoluciferin). To a 50-mL round-bottomed flask was added D, L-cysteine (688 mg, 5.68 mmol) and deionized water (14 mL, degassed with bubbling nitrogen for 15 min). The resulting mixture was magnetically stirred until dissolution was achieved. To a separate 25-mL erlenmeyer flask was added anhydrous potassium carbonate (785 mg, 5.68 mmol) and degassed deionized water (14 mL). The resulting solution was added in portions via pasteur pipet to the flask containing the D, L-cysteine solution, with periodic addition of 6N hydrochloric acid as needed to maintain a pH less than 7.5. After addition of the potassium carbonate solution to the reaction flask was complete, a portion of the reaction mixture (10.1 mL, containing approximately 2.04 mmoles of D, L-cysteine) was measured (via graduated cylinder) and transferred to a separate 50 mL erlenmeyer flask. This mixture was diluted with 15 mL of degassed methanol and the resulting solution was transferred to a 100 mL round-bottomed flask containing a solution of 2-cyano-6-trifluoroacetylaminobenzothiazole (White et al., 1966) (552 mg, 2.04 mmol) in degassed methanol (17 mL). The reaction mixture was magnetically stirred at room temperature and the reaction flask was covered with aluminum foil. After stirring for 1 h, TLC and HPLC analysis indicated only traces of starting material remaining. The reaction mixture was diluted with water (79 mL) and the pH was found to be ˜8.0. The reaction mixture was transferred to a separatory funnel (250 mL) and extracted with ethyl acetate (79 mL) to remove neutral organic compounds. The aqueous phase was acidified to pH 2 by addition of 6N hydrochloric acid, resulting in a sticky off-white precipitate that was stored overnight at 5° C. The suspension was transferred to 50-mL centrifuge tubes and centrifuged for about 3 min. The supernatant was decanted and the pellet was washed with cold water and centrifuged three times. The pellet was suspended in methanol and transferred to a 250 mL round-bottomed flask. The suspension was concentrated by rotoevaporation and then coevaporated with dichloromethane to afford a crude pale yellow solid. The crude product was purified by flash chromatography on 24 g of silica gel using 9:1 dichloromethane-methanol as eluting solvent. A second chromatography column was required and employed 100 g of silica gel and 9:1 dichloromethane-methanol as eluting solvent, providing 660 mg (86%) of a pale yellow solid. MS (ESI − ) m/z 375 (M-H) − .
REFERENCES
Fernandes-Alnemri et al., PNAS USA, 93: 7464 (1996).
Garcia-Calvo et al., Cell Death Diff., 6: 362 (1999).
Masuda-Nishimura et al., Letters in Applied Microbio., 30: 130 (2000).
Miska et al., Biol. Chem. Hoppe-Sexler, 369: 407 (1985).
Miska et al., J. Clin. Chem. Clin. Biochem., 25: 23 (1987).
Monsees et al., Anal. Biochem., 221: 329 (1994).
Monsees et al., J. Biolum. Chemilum., 10: 213 (1995).
Nicholson et al., Nature, 376: 37 (1995).
Tewari et al., Cell, 81: 801 (1995).
Thornberry et al., Nature, 356: 768 (1992).
Thornberry et al., J. Biol. Chem., 272: 17907 (1997).
White et al., J. Am. Chem. Soc., 88: 2015 (1966).
All publications, patents and patent applications are incorporated herein by reference. While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purposes of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein may be varied considerably without departing from the basic principles of the invention.
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A sensitive bioluminescent assay to detect proteases including caspases is provided which employs an aminoluciferin or a carboxy-terminal protected derivative thereof covalently linked via a peptide bond to a substrate for a caspase or an aminoluciferin or a carboxy-terminal protected derivative thereof covalently linked via a peptide bond to a peptide substrate comprising aspartate that is specifically cleaved by a protease specific for the substrate.
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FIELD
[0001] The present invention relates to building products and more particularly, to windows and window frames.
BACKGROUND
[0002] Some windows utilize vent surrounds and frames made from metal, e.g., aluminum alloy. Metal windows are in use in residential and commercial buildings, e.g., in storefronts and in curtain walls used on the façade of high-rise buildings. The energy transfer characteristics of windows are an important factor in the overall energy efficiency of a building and there is a continual search for building features and methods of construction that improve energy efficiency. Improved and/or alternative structures and methods for controlling the heat transfer characteristics of windows remain desirable.
SUMMARY
[0003] The disclosed subject matter relates to an access structure for an opening through a building envelope, including a frame structure coupled to the building, framing the opening and a spanning element spanning the frame structure, at least partially covering the opening. The spanning element has at least one panel and a surround embracing the periphery of the panel, the frame structure having a parallel portion extending parallel to the spanning element in a spanning direction and a perpendicular portion extending perpendicular to the spanning element relative to a spanning direction. At least one of the perpendicular portion of the frame structure and the surround being a composite of a metal portion and a non-metal portion, the non-metal portion having a lower thermal conductivity than the metal portion, the non-metal portion being exposed to a first environment on a first side of the building envelope and the metal portion being proximate a second environment on a second side of the building envelope.
[0004] In one approach, the access structure is a window providing access to light and the at least one panel is a glazing panel.
[0005] In one approach, the window has an opened and a closed position.
[0006] In one approach, the surround includes a box portion made from metal and the perpendicular portion includes a non-metallic ledge that attaches to the box portion.
[0007] In one approach, the box portion has an elongated channel and the non-metallic ledge has an L-shaped cross-sectional shape, the ledge having an insertion leg capable of being received in the elongated channel and forming a portion of the L-shape.
[0008] In one approach, the ledge has at least one finger extending therefrom in a direction opposite to the insertion leg for reducing airflow proximate the ledge.
[0009] In one approach, the insertion leg has a plurality of burrs having a directionality that promotes insertion of the insertion leg into the channel and opposes withdrawal therefrom.
[0010] In one approach, the ledge has a front-to-back slope capable of promoting water runoff.
[0011] In one approach, the ledge has a plateau at the base of the insertion leg that mates with a mating recess communicating with the channel to establish a given relative orientation.
[0012] In one approach, the perpendicular portion of the frame has a connection bead that is capable of snap-fitting to an adaptor, the adaptor being non-metallic.
[0013] In one approach, the adaptor, when in place on the connection bead is proximate at least one seal extending from the surround when the spanning element at least partially covers the opening.
[0014] In one approach, the connection bead has a bifurcated arrowhead cross-sectional shape having a pair of opposed lead-in surfaces that interact with corresponding sloped surfaces on opposed arms of the adaptor, which define a hollow there between having a shape complementary to the connection bead, the arms resiliently displacing when pushed against the lead-in surfaces and snapping to a closed position when pushed beyond the lead-in surfaces.
[0015] In one approach, the arrowhead cross-sectional shape has a recess at the tip to receive sealant.
[0016] In one approach, the window is fixed.
[0017] In one approach, the access structure is a door.
[0018] In one approach, the at least one of the composite frame structure and surround are composite via an interlocking interface, such that a plurality of interchangeable parts may be attached at the interface giving rise to modularity supporting use of the access structure for a plurality of different applications.
[0019] In one approach, both the frame structure and the surround are composite.
[0020] In one approach, the metal portion is formed from an aluminum alloy and the non-metallic portion is formed from a polymer.
[0021] In one approach, the first environment is the out-of-doors and the second environment is interior to the building envelope.
[0022] In one approach, both the frame structure and the surround are formed from a plurality of elongated elements attached together at the ends thereof.
[0023] In one approach, the adaptor has a raceway distal to the opposed arms for receiving a trim cover.
[0024] In one approach, a method for assembling a window for an opening through a building envelope, includes obtaining a plurality of elongated frame elements made from aluminum alloy extrusions and attaching them together at the ends thereof to form a frame structure; obtaining a plurality of elongated box sections made from aluminum alloy extrusions and having an outward facing channel; attaching the plurality of elongated box sections together at the ends thereof to form a first portion of a window surround; obtaining a glazing panel; obtaining a plurality of L-shaped ledge portions made from polymer and having insertion legs; inserting the insertion legs of the ledge portions into corresponding channels of the box sections to form a surround capable of embracing the periphery of the glazing panel and inserting the glazing panel into the surround to form a vent assembly; attaching the frame structure to the building, framing the opening; and attaching the vent assembly to the frame structure.
[0025] In one approach, a method for assembling a window for an opening through a building envelope, includes obtaining a plurality of elongated frame elements made from aluminum alloy extrusions and having an attachment bead disposed on a surface thereof; attaching the elongated frame elements together at the ends thereof to form a frame structure; obtaining a plurality of polymer adaptors having a coupling head; attaching the adaptors to corresponding ones of the frame elements by snap-fitting the coupling head over the attachment bead to form a frame assembly; obtaining a plurality of elongated vent surround sections made from aluminum alloy extrusions; attaching the plurality of elongated vent surround sections together at the ends thereof to form a vent surround; obtaining a glazing panel; inserting the glazing panel into the vent surround to form a vent assembly; attaching the frame structure to the building, framing the opening; and attaching the vent assembly to the frame structure.
[0026] In one approach, a vent surround, includes a box portion made from a plurality of metal sub-sections connected at the ends thereof and a non-metallic ledge with a plurality of sub-sections that attach to the sub-sections of the box portion, the sub-sections of the box portion each having an elongated channel and each of the sub-sections of the non-metallic ledge having an L-shaped cross-sectional shape with an insertion leg capable of being received in the elongated channel, the non-metallic ledge having a lower thermal conductivity than the metal box portion, the non-metallic ledge being proximate a first environment on a first side of the building envelope and the metal box portion being proximate a second environment on a second side of the building envelope.
[0027] In one approach, a frame structure couplable to a building to frame an opening through the building envelope includes a metallic base portion that couples to the building; a metallic extension portion extending perpendicular to the building envelope proximate the opening; a non-metallic adaptor capable of being coupled to the extension portion, the non-metallic adaptor having a lower thermal conductivity and position proximate a first environment on an exterior of the building envelope and the metallic base and extension portions having a higher thermal conductivity and positioned proximate a second environment on the interior of the building envelope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] For a more complete understanding of the present disclosure, reference is made to the following detailed description of exemplary embodiments considered in conjunction with the accompanying drawings.
[0029] FIG. 1 is elevational view of a fragment of a window system.
[0030] FIG. 2 is a cross-sectional view of a sill of the window system of FIG. 1 taken along section line 2 - 2 and looking in the direction of the arrows.
[0031] FIG. 3 is a cross-section like FIG. 2 , but of a window system in accordance with an embodiment of the present disclosure.
[0032] FIG. 4 is a perspective view of a ledge portion of a vent surround.
[0033] FIG. 5 is a side view of the ledge portion of FIG. 4 and alternative ledge portions.
[0034] FIG. 6 is a cross-section like FIG. 2 , but of a window system in accordance with another embodiment of the present disclosure.
[0035] FIG. 7 is an enlarged portion of FIG. 3 .
[0036] FIG. 8 is a perspective view of a frame adaptor in accordance with another embodiment of the present disclosure.
[0037] FIG. 9 is a series of cross-sectional views of frame adaptors in accordance with embodiments of the present disclosure.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0038] FIG. 1 shows a window system 10 , e.g., for a façade of a commercial building, such as a multi-story high rise building. Using conventional terminology, each window unit 12 of the window system 10 has a head 14 , a sill 16 and jambs 18 . The jambs 18 between adjacent window units 12 may be designated mullions. Some or all of the window units 12 may be hinged to be opened and closed for ventilation. For applications where there is no protective roof or awning overhang, the window unit would typically open at the sill 16 . In other applications, the window units 12 may open at the head 14 or at the jambs 18 .
[0039] FIG. 2 is a cross-sectional view of a window unit 12 of FIG. 1 at the sill 16 in accordance with the prior art. A compound structural beam 20 having an interior portion 20 I and an exterior portion 20 E separated by a thermal break 22 and bridged by a plate 24 is a component of the building structure, e.g., a storefront. The beam 20 is attached to the superstructure of the building and serves as the mounting surface for a window frame element 26 , which may be fastened to the beam 20 by screws 28 or other fasteners extending through a peripheral portion 26 P. A plurality of attached frame elements 26 , e.g., four (at the head, sill and jambs) may be used to define a rectangular frame for the window unit 12 . The frame elements 26 may be L shape in cross section, a limiting portion 26 L limiting the motion of a vent 30 in the direction of the interior I. The vent 30 is the portion of the window unit 12 that typically contains an optically transparent/translucent glazing unit 32 , e.g., one or more (e.g., double or triple glazed windows) glass or plastic panels 32 A, 32 B separated by an intermediate spacer 34 , defining a space 36 , which may contain air, an inert gas or radiation/convection barrier films. A peripheral setting block 38 is attached to the edge of the panels 32 A, 32 B to protect glazing unit 32 from being damaged by direct contact with vent surround ledge portion 40 L. The vent surround 40 may be made from a plurality of extrusions that are coupled together to embrace the glazing unit 32 at all sides thereof, e.g., four sides for rectangular glazing panels 32 A, 32 B. For example, the vent surround 40 may be formed from four aluminum alloy extrusions that are miter cut at the ends thereof and then assembled, by welding, staking and/or with brackets and/or fasteners. The vent surround 40 may have a boxed portion 40 B to impart structural rigidity and an integrally formed ledge portion 40 L that surrounds the glazing unit 32 . The glazing unit 32 may be secured to the vent surround 40 by the use of a silicone sealant 42 A, 42 B.
[0040] A first seal 44 , which may be formed from an elastomer is attached to the vent surround 40 and reduces weather infiltration between the window frame elements 26 and the vent surround 40 . A second seal 45 attached either to the frame elements 26 or the vent surround 40 (but not both) may aid in preventing weather intrusion into the interior I. The seals 44 and 45 allow the vent surround 40 to be moved relative to the frame elements 26 , such that the window unit 12 may be opened and closed, while decreasing weather (air and water) infiltration.
[0041] An aspect of the present disclosure is the recognition that the vent surround 40 is a conduit for heat transfer from the environment E exterior to the window unit 12 to an environment I interior to the window unit 12 (inside a building).
[0042] FIG. 3 is a cross-section of a window unit 112 in the sill 116 area like the window unit 12 of FIG.2 , but in accordance with an embodiment of the present disclosure. The window unit 112 features a composite vent surround 140 featuring a boxed portion 146 made, e.g., from aluminum alloy to impart structural rigidity, and an independently formed ledge portion 148 made, e.g., from a polymer, such as rigid PVC or glass reinforced nylon, having a lower heat conductivity than aluminum. Ledge portion 148 has an insertion leg 150 which may have a plurality of engagement ribs/barbs 152 (See FIGS. 4 and 5 ) that are disposed at an angle B relative to the insertion leg 150 , the angle facilitating insertion into and resisting removal from a channel 146 C in the box section 146 . The insertion leg 150 may be retained in the slot 146 C by friction fit, the action of the ribs/barbs 152 and/or an adhesive. As in the window unit 12 described above, a plurality, e.g., four, vent surrounds 140 with associated box portions 146 and ledge portion 148 may be assembled together to surround and retain the glazing unit 130 . The aluminum alloy boxed portions 146 may be connected by welding, brackets and fasteners, etc., thereby forming a rigid framework for mounting the ledge portions 148 , which may also be attached together, e.g., by screws or rivets. The glazing unit 130 may be adhered to the box section 146 by a sealant 142 A and the window unit may also feature a a peripheral setting block 142 B (shown in dashed lines tofor eas of illustration).
[0043] FIGS. 3 , 4 and 5 shows that the ledge portion 148 may be provided with a self-centering plateau 154 that matingly engages corresponding surfaces of the channel 146 C to automatically establish a pre-selected relative orientation between the ledge portion 148 and the box portion 146 . A hinge hardware locating nub 155 provides a reference surface for uniform and precise hinge hardware positioning when hinges are used and acts in conjunction with insertion stop 157 to limit insertion and stabilize the ledge portion 148 relative to the box portion 146 . The ledge portion 148 has a plurality of thermal barrier fingers 159 made, e.g., from high durometer, soft PVC or other flexible materials, that may bear against or pass close to an opposing surface to reduce the passage of air and consequent transfer of energy. As explained more fully below, the window unit 112 embodiment shown in FIG. 3 features a composite frame element 126 with a bifurcated coupling bead or barb 168 upon which a frame extension/adaptor 170 may be received and retained. The adaptor 170 abuts against (and displaces) the first finger 159 F to effect a weather seal. The fingers 159 may be spaced to minimize thermal conduction, as explained further below.
[0044] The ledge portion 148 , which may be considered a first ledge portion 148 , has an integrated screw port 156 for receiving screws S (one screw head shown diagrammatically in dotted lines) extending through an adjacent second ledge portion 148 to hold the adjacent second ledge portion to a first ledge portion 148 via a screw screwed through the second ledge portion and extending into the screw port 156 . For example, if a first ledge portion 148 (as depicted in FIG. 3 ) is disposed along the sill then a second ledge portion 148 disposed along the adjacent jamb may be tightly attached to the sill ledge portion 148 via a screw that extends through the jamb ledge portion 148 and into the screwport 156 of the sill ledge portion 148 . A flat offset area 158 allows the first and second ledge portions 148 to seat flush to one another and defines a ledge that prevents relative translational movement when the screw S is tightened.
[0045] An integral raceway 160 accommodates a variety of trim covers 162 or other modular parts in snap-fit relationship. The trim cover 162 covers the adjacent edge of the glazing unit 130 and also extends down to reduce weather infiltration. The box section 140 also features a raceway 164 for receiving a bead seal 166 that seals against limiting portion 126 L of window frame element 126 . The frame element 126 has a bifurcated coupling bead 168 at an end thereof for coupling to a selected adaptor 170 , as described more fully below. The adapter 170 may be selected to interact advantageously with a given window unit installation environment (to reduce heat transfer/weather infiltration) and also to accommodate different types of glazing units 130 , e.g., double and triple glazed. FIG. 4 shows that the ledge 148 may have a surface 148 S from which the fingers 159 extend with a front-to-back taper angle alpha of e.g., 1 degree. The taper angle may be used to shed water away from the window unit 112 when the ledge portion is used at the head 14 , i.e., with the fingers 159 pointed up. Alternatively, the extending portion 148 E may be molded at an angle less than 90 degrees relative to the insertion leg 150 .
[0046] FIG. 5 shows that different ledge portions 148 , 148 A, 148 B, 148 C with different dimensions and number of fingers 159 , 159 A, 159 B, 159 C may utilize the same features, e.g., insertion leg 150 , plateau 154 , hinge nub 155 and insertion stop 157 , that allow coupling the ledge portions 148 , 148 A, etc. to the same type of box portion 146 . In a similar manner, the box portion 146 may be varied in dimensions but have a consistently shaped and dimensioned channel 146 C that may couple in a consistent manner to one or more different ledge portions 148 . The consistent coupling features lead to modularity, i.e., multiple parts with variations optionally coupling to multiple parts with variations, in the same manner. Ledge portion 148 with fingers 159 (all in solid lines) is an example of a ledge portion 148 that may be suitable for use with a double glazed glazing unit 130 used in a storefront application. The dimensions of ledge portion 148 may be varied, e.g., to be suitable for use in a curtain wall application by extending the length of fingers 159 A, yielding a variant ledge portion 148 A. Ledge portion 148 B with fingers 159 B (in dashed lines) may be suitable for a triple glazed storefront window. For a curtain wall application, the fingers 159 B can be lengthened, as shown by 159 C to yield a variant ledge portion 148 C. Notwithstanding the variations in dimensions of the ledge portions 148 , 148 A, 148 B, the tooling used to process an elongated extrusion, e.g., eighteen feet in length, into assemblable portions of a given length for surrounding a given glazing unit 130 , may remain consistent. For example, a cutter (not shown) used to remove a length, e.g., 4.25 to 5.0 inches of the insertion leg 150 at either end of the horizontal lengths of the ledge portion 148 to permit mating with the vertical lengths, may be the same for each variant of the ledge portions 148 A, 148 B and 148 C. Similarly, tools for miter cutting, punching or drilling the holes for passing screws S, etc. may be standardized for a variety of ledge portions with different dimensions.
[0047] FIG. 6 is a cross-section of a window unit 112 in the sill 116 area like the window unit 12 of FIG. 3 , but with a different type of adaptor 270 . As before, the window unit 112 features a composite vent surround 140 featuring a boxed portion 146 made, e.g., from aluminum alloy to impart structural rigidity, and an independently formed ledge portion 148 made, e.g., from a polymer, such as rigid PVC or glass reinforced nylon, having a lower heat conductivity than aluminum. The composite frame element 126 has a bifurcated coupling bead or barb 168 upon which a frame extension/adaptor 270 may be received and retained. The adaptor 270 is made from a polymer, such as rigid PVC or glass reinforced nylon, having a lower heat conductivity than aluminum and abuts against (and displaces) the first finger 159 F to create a weather seal. An extension portion 270 E extends below and proximate to the ends of fingers 159 A, 159 B and trim cover 162 to further improve weather resistance. Optionally, the fingers 159 A, 159 B may contact the extension 270 E.
[0048] FIG. 7 shows the coupling bead/barb 168 with dual lead-in surfaces 168 A, 168 B that meet negatively cambered surfaces 168 C, 168 D at a cusp or point. The adaptor 170 has a coupling portion 171 having a pair of opposed arms 170 A 1 and 170 A 2 with complementary, mating surfaces, viz., sloped lead-in surfaces 170 B 1 , 170 B 2 that meet positively cambered surfaces 170 C, 170 D at a rounded point. The lead-in surfaces 168 A, 168 B and 170 B 1 , 170 B 2 facilitate inserting the barb 168 into the cavity 170 E of the coupling portion 171 , the adaptor 170 resiliently bending and then snapping back into a rest configuration when the barb 168 is fully inserted into the cavity 170 E in the engaged position. When in the engaged position, the surfaces 168 C, 168 D and mating surfaces 170 C, 170 D hinder dis-engagement and ensure a positive locking interaction with minimal rotation. Central recesses 168 F and 170 F accommodate a bead sealant (not shown) that is applied prior to assembly to aid in preventing water infiltration. Surfaces 170 B 1 , 170 B 2 closely parallel surfaces 168 G, 168 H when the adaptor 170 is coupled to the coupling bead 168 to aid in sealing the coupled adaptor 170 and coupling bead 168 .
[0049] FIG. 8 shows the adaptor 270 of FIG. 6 prior to connection to a coupling bead 168 of window frame element 126 . An extension portion 270 E extends from coupling portion 271 .
[0050] FIGS. 9A-9F show a series of frame adaptors 370 , 470 , 570 , 670 , 770 , 870 , e.g., that may be used in the context of a curtain wall window system. FIG. 9F shows a perspective view of the frame adaptor 870 . The adaptors 370 , 470 , 570 , 670 , 770 , 870 are varied in dimensions and have various extensions, e.g., 370 E, 470 E, 570 E, 670 E, 770 E, 870 E with different dimensions and features, e.g., the positioning of the screw ports 356 - 856 and wings 380 , 480 , 680 , 780 , but have a common configuration with respect to coupling portion 371 , 471 , 571 , etc., which have coupling arms, e.g., 370 A 1 , 370 A 2 , 470 A 1 , 470 A 2 , allowing the different adaptors to be attached to the same types of coupling bead 168 ( FIG. 7 ).
[0051] While the foregoing describes composite vent surrounds 140 and composite window frames 126 with metal and plastic components explained relative to use in a sill 116 , the head 14 , and jambs 18 may be similarly formed from composite elements to reduce heat transfer and weather infiltration.
[0052] It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the claimed subject matter. For example, while the present disclosure has been expressed relative to windows, the disclosed concepts could be applied to doors, non-window vents and other building structures. All such variations and modifications are intended to be included within the scope of the appended claims.
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A manufacture for reducing thermal transfer through windows has a composite metal/nonmetallic frame and/or a composite vent surround. The metallic and non-metallic components are modular and selectively coupled, such that a range of variations to accommodate different applications may be inter-coupled via common interfaces.
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This application is a division of application Ser. No. 08/171,387 filed Dec. 21, 1993, now U.S. Pat. No. 5,552,415.
BACKGROUND OF THE INVENTION
Alzheimer's Disease (AD) is a degenerative brain disorder characterized clinically by progressive loss of memory, cognition, reasoning, judgment and emotional stability that gradually leads to profound mental deterioration and ultimately death. AD is a common cause of progressive mental failure (dementia) in aged humans and is believed to represent the fourth most common medical cause of death in the United States. AD has been observed in varied races and ethnic groups worldwide and presents a major present and future public health problem. The disease is currently estimated to affect about two to three million individuals in the United States alone. To date, AD has proven to be incurable.
The brains of individuals with AD exhibit neuronal degeneration and characteristic lesions variously referred to as amyloidogenic plaques, vascular amyloid angiopathy, and neurofibrillary tangles. Large numbers of these lesions, particularly amyloidogenic plaques and neurofibrillary tangles, are generally found in several areas of the human brain important for memory and cognitive function in patients with AD. Smaller numbers of these lesions in a more restricted anatomical distribution are found in the brains of most aged humans who do not have clinical AD. Amyloidogenic plaques and vascular amyloid angiopathy also characterize the brains of individuals with Trisomy 21 (Down's Syndrome) and Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type (HCHWA-D). At present, a definitive diagnosis of AD usually requires observing the aforementioned lesions in the brain tissue of patients who have died with the disease or, rarely, in small biopsied samples of brain tissue taken during an invasive neurosurgical procedure.
Several lines of evidence indicate that progressive cerebral deposition of particular amyloidogenic proteins, β-amyloid proteins, (βAP), play a seminal role in the pathogenesis of AD and can precede cognitive symptoms by years or decades. See, Selkoe, (1991) Neuron 6:487. Recently, it has been shown that βAP is released from neuronal cells grown in culture and is present in cerebrospinal fluid (CSF) of both normal individuals and AD patients. See, Seubert et al., (1992) Nature 359:325-327.
A possible correlation to the plaque pathology has been developed by several groups demonstrating the direct βAP neurotoxicity toward, cultured neurons. Direct neurotoxicity of βAP was recently reported to be attenuated by co-treatment with TGF-β (Chao et al., Soc. Neurosci. Abs., 19:1251 (1993)).
More recently, in addition to the direct neurotoxicity, an inflammatory response in the AD brain, perhaps elicited by βAP, also contributes to the pathology of the disease. A limited clinical trial with the NSAID indomethacin exhibited a retardation in the progression of Alzheimer's dementia (Rogers et al., Science, 260:1719-1720 (1993)).
Despite the progress that has been made in understanding the underlying mechanisms of AD, there remains a need to develop compositions and methods for treatment of these diseases. Treatment methods could advantageously be based on drugs which are capable of increasing TGF-β expression in the brain, thus ameliorating the β-amyloid peptide mediated neurotoxicity and inflammatory response associated with AD.
SUMMARY OF THE INVENTION
This invention encompasses methods for the inhibition of Alzheimer's disease, which method comprises administering to a human in need thereof an effective amount of a compound of formula I ##STR3## wherein R 1 and R 3 are independently hydrogen, ##STR4## wherein Ar is optionally substituted phenyl; R 2 is selected from the group consisting of pyrrolidino, hexamethylenemino, and piperidino; or a pharmaceutically acceptable salt of solvate thereof.
The present invention also provides a method of increasing TGF-β expression in the brain, comprising administering to a human in need thereof an effective amount of a compound of formula 1.
The present invention also provides a method of inhibiting the β-amyloid peptide mediated neurotoxicity and inflammatory response associated with Alzheimer's Disease (AD) comprising administering to a human in need thereof an effective amount of a compound of formula 1.
DETAILED DESCRIPTION OF THE INVENTION
The current invention concerns the discovery that a select group of benzothiophenes, those of formula I, are useful for inhibiting the effects of Alzheimer's Disease, and in particular the compounds are believed to inhibit the inflammatory response associated with the disease by increasing TGF-β expression in the brain. The invention encompasses uses practiced by administering to a human in need thereof a dose of a compound of formula 1 or a pharmaceutically acceptable salt or solvate thereof effective to inhibit Alzheimer's Disease. The methods include both therapeutic and prophylactic administration.
The term "inhibit" includes its generally accepted meaning which includes prohibiting, preventing, restraining, and slowing, stopping, or reversing progression, severity, or a resultant symptom or effect.
The term "effective amount" means the amount of compound necessary to inhibit Alzheimer's Disease or any of its symptoms, inhibit β-amyloid peptide mediated neurotoxicity or the inflammatory response associated with Alzheimer's Disease, or increase TGF-β expression in the brain, as the case may be.
Generally, the compound is formulated with common excipients, diluents or carriers, and compressed into tablets, or formulated as elixirs or solutions for convenient oral administration, or administered by the intramuscular or intravenous routes. The compounds can be administered transdermally, and may be formulated as sustained release dosage forms and the like.
The compounds used in the methods of the current invention can be made according to established and analogous procedures, such as those detailed in U.S. Pat. Nos. 4,133,814, 4,418,068, and 4,380,635 all of which are incorporated by reference herein. In general, the process starts with a benzo[b]thiophene having a 6-hydroxyl group and a 2-(4-hydroxyphenyl) group. The starting compound is protected, alkylated or acylated, and deprotected to form the formula I compounds. Examples of the preparation of such compounds are provided in the U.S. patents discussed above, and in the examples in this application. Optionally substituted phenyl includes phenyl and phenyl substituted once or twice with C 1 -C 6 alkyl, C 1 -C 4 alkoxy, hydroxy, nitro, chloro, fluoro, or tri(chloro or fluoro)methyl.
Included in this invention is the compound raloxifene, below: ##STR5##
The compounds used in the methods of this invention form pharmaceutically acceptable acid and base addition salts with a wide variety of organic and inorganic acids and bases and include the physiologically acceptable salts which are often used in pharmaceutical chemistry. Such salts are also part of this invention. Typical inorganic acids used to form such salts include hydrochloric, hydrobromic, hydroiodic, nitric, sulfuric, phosphoric, hypophosphoric and the like. Salts derived from organic acids, such as aliphatic mono and dicarboxylic acids, phenyl substituted alkanoic acids, hydroxyalkanoic and hydroxyalkandioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, may also be used. Such pharmaceutically acceptable salts thus include acetate, phenylacetate, trifluoroacetate, acrylate, ascorbate, benzoate, chlorobenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, methylbenzoate, o-acetoxybenzoate, naphthalene-2-benzoate, bromide, isobutyrate, phenylbutyrate, β-hydroxybutyrate, butyne-1,4-dioate, hexyne-1,4-dioate, caprate, caprylate, chloride, cinnamate, citrate, formate, fumarate, glycollate, heptanoate, hippurate, lactate, malate, maleate, hydroxymaleate, malonate, mandelate, mesylate, nicotinate, isonicotinate, nitrate, oxalate, phthalate, teraphthalate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, propiolate, propionate, phenylpropionate, salicylate, sebacate, succinate, suberate, sulfate, bisulfate, pyrosulfate, sulfite, bisulfite, sulfonate, benzene-sulfonate, p-bromophenylsulfonate, chlorobenzenesulfonate, ethanesulfonate, 2-hydroxyethanesulfonate, methanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, p-toluenesulfonate, xylenesulfonate, tartarate, and the like. A preferable salt is the hydrochloride salt.
The pharmaceutically acceptable acid addition salts are typically formed by reacting a compound of formula I with an equimolar or excess amount of acid. The reactants are generally combined in a mutual solvent such as diethyl ether or benzene. The salt normally precipitates out of solution within about one hour to 10 days and can be isolated by filtration or the solvent can be stripped off by conventional means.
Bases commonly used for formation of salts include ammonium hydroxide and alkali and alkaline earth metal hydroxides and carbonates, as well as aliphatic and aromatic amines, aliphatic diamines and hydroxy alkylamines. Bases especially useful in the preparation of addition salts include ammonium hydroxide, potassium carbonate, sodium bicarbonate, calcium hydroxide, methylamine, diethylamine, ethylene diamine, cyclohexylamine and ethanolamine.
The pharmaceutically acceptable salts generally have enhanced solubility characteristics compared to the compound from which they are derived, and thus are often more amenable to formulation as liquids or emulsions.
Pharmaceutical formulations can be prepared by procedures known in the art. For example, the compounds can be formulated with common excipients, diluents, or carriers, and formed into tablets, capsules, suspensions, powders, and the like. Examples of excipients, diluents, and carriers that are suitable for such formulations include the following: fillers and extenders such as starch, sugars, mannitol, and silicic derivatives; binding agents such as carboxymethyl cellulose and other cellulose derivatives, alginates, gelatin, and polyvinyl pyrrolidone; moisturizing agents such as glycerol; disintegrating agents such as agaragar, calcium carbonate, and sodium bicarbonate; agents for retarding dissolution such as paraffin; resorption accelerators such as quaternary ammonium compounds; surface active agents such as cetyl alcohol, glycerol monostearate; adsorptive carriers such as kaolin and bentonite; and lubricants such as talc, calcium and magnesium stearate, and solid polyethyl glycols.
The compounds can also be formulated as elixirs or solutions for convenient oral administration or as solutions appropriate for parenteral administration, for instance by intramuscular, subcutaneous or intravenous routes. Additionally, the compounds are well suited to formulation as sustained release dosage forms and the like. The formulations can be so constituted that they release the active ingredient only or preferably in a particular part of the intestinal tract, possibly over a period of time. The coatings, envelopes, and protective matrices may be made, for example, from polymeric substances or waxes.
Compounds of Formula I can be administered for prophylactic and/or therapeutic treatment of Alzheimer's Disease. In therapeutic applications, the compounds are administered to a host already suffering from a disease.
For prophylactic applications, the compounds of formula I are administered to a host susceptible to Alzheimer's Disease, but not necessarily already suffering from such disease. Such hosts may be identified by genetic screening and clinical analysis, as described in the medical literature, see e.g., Goate, Nature, 349:704-706 (1991). A preferred group for receiving compounds of the invention, either for prophylactic or therapeutic reasons, are post-menopausal women. (see e.g., Paganini-Hill, Soc Neurosci Abs, 19, 1046).
The particular dosage of a compound of formula I according to this invention will depend upon the severity of the condition, the route of administration, and related factors that will be decided by the attending physician. Generally, accepted and effective daily doses will be from about 0.1 to about 1000 mg/day, and more typically from about 50 to about 200 mg/day. Such dosages will be administered to a subject in need of treatment from once to about three times each day, or more often as needed, for a period of time sufficient to inhibit the effects of Alzheimer's Disease or its symptoms.
Frequently, it will be desirable or necessary to introduce the pharmaceutical compositions directly or indirectly to the brain. Direct techniques usually involve placement of a drug delivery catheter into the host's ventricular system to bypass the blood-brain barrier. Indirect techniques, which are generally preferred, involve formulating the compositions to provide for drug latentiation by the conversion of hydrophilic drugs into lipid-soluble drugs. Latentiation is generally achieved through blocking of the hydroxyl, carboxyl, and primary amine groups present on the drug to render the drug more lipid soluble and amenable to transportation across the blood-brain barrier. Alternatively, the delivery of hydrophilic drugs can be enhanced by intra-arterial infusion of hypertonic solutions which can transiently open the blood-brain barrier.
It is usually preferred to administer a compound of formula I in the form of an acid addition salt, as is customary in the administration of pharmaceuticals bearing a basic group, such as the piperidino ring. For such purposes the following dosage forms are available.
FORMULATIONS
In the formulations which follow, "Active ingredient" means a compound of formula I.
______________________________________Formulation 1: Gelatin CapsulesHard gelatin capsules are prepared using the following:Ingredient Quantity (mg/capsule)______________________________________Active ingredient 0.1-1000Starch, NF 0-650Starch flowable powder 0-650Silicone fluid 350 centistokes 0-15______________________________________
The ingredients are blended, passed through a No. 45 mesh U.S. sieve, and filled into hard gelatin capsules.
Examples of specific capsule formulations of the compound raloxifene that have been made include those shown below:
______________________________________Formulation 2: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 1Starch, NF 112Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7______________________________________Formulation 3: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 5Starch, NF 108Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7______________________________________Formulation 4: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 10Starch, NF 103Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7______________________________________Formulation 5: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 50Starch, NF 150Starch flowable powder 397Silicone fluid 350 centistokes 3.0______________________________________
The specific formulations above may be changed in compliance with the reasonable variations provided.
A tablet formulation is prepared using the ingredients below:
______________________________________Formulation 6: TabletsIngredient Quantity (mg/tablet)______________________________________Active ingredient 0.1-1000Cellulose, microcrystalline 0-650Silicon dioxide, fumed 0-650Stearate acid 0-15______________________________________
The components are blended and compressed to form tablets.
Alternatively, tablets each containing 0.1-1000 mg of active ingredient are made up as follows:
______________________________________Formulation 7: TabletsIngredient Quantity (mg/tablet)______________________________________Active ingredient 0.1-1000Starch 45Cellulose, microcrystalline 35Polyvinylpyrrolidone 4(as 10% solution in water)Sodium carboxymethyl cellulose 4.5Magnesium stearate 0.5Talc 1______________________________________
The active ingredient, starch, and cellulose are passed through a No. 45 mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the resultant powders which are then passed through a No. 14 mesh U.S. sieve. The granules so produced are dried at 50°-60° C. and passed through a No. 18 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate, and talc, previously passed through a No. 60 U.S. sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets.
Suspensions each containing 0.1-1000 mg of medicament per 5 mL dose are made as follows:
______________________________________Formulation 8: Suspensions QuantityIngredient (mg/5 ml)______________________________________Active ingredient 0.1-1000 mgSodium carboxymethyl cellulose 50 mgSyrup 1.25 mgBenzoic acid solution 0.10 mLFlavor q.v.Color q.v.Purified water to 5 mL______________________________________
The medicament is passed through a No. 45 mesh U.S. sieve and mixed with the sodium carboxymethyl cellulose and syrup to form a smooth paste. The benzoic acid solution, flavor, and color are diluted with some of the water and added, with stirring. Sufficient water is then added to produce the required volume.
Assays
Experimental Design.
For Assay 1 and 2, the following experimental design is provided.
Amylins may be purchased from Bachem, Inc. (Torrance, Calif.), Peninsula Laboratories, Inc. (Belmont, Calif.), Sigma Chemicals (St. Louis, Mo.) or may be synthesized as described infra. Amyloid-β(1-40) and reverse β-amyloid peptide(40-1) may be purchased from Bachem, Inc. β 2 -microglobulin may be purchased from Sigma Chemicals (St. Louis, Mo.).
Stock solutions of peptides (1 mM) are freshly prepared in pyrogen-free sterile water and diluted to the indicated concentrations in defined culture media. Rat hippocampal cultures (10-14 days in vitro) are treated with peptides or vehicle for four days. The viability of the rat cortical cultures is visually assessed by phase contrast microscopy and quantified by measuring lactate dehydrogenase (LDH) released into the culture media.
Assay 1
Primary rat hippocampal neurons are cultured in vitro with standard cell culture techniques. Amyloid-beta (Aβ) peptide is added to cultured cells at a normally toxic concentration of 25-50 μM. After 4 days of treatment, viability is assessed by measurement of lactate dehydrogenase (LDH) released into culture medium. Lactate dehydrogenase (LDH) is measured in 20 μl aliquots of conditioned defined-DMEM using a standard 340 nm kinetic LDH assay (Sigma Catalog Number #228-20) in a 96 well format. Assays are performed at 37° C. in a PC-driven EL340 Microplate Biokinetics plate reader (Bio-Tek Instruments) using Delta Soft II software (v. 3.30B, BioMetallics, Inc.) for data analysis. Quality control standards containing normal and elevated levels of serum LDH (for example, Sigma Enzyme Controls 2N and 2E) are run with every assay. Results are expressed as units of LDH/L where 1 unit is defined as the amount of enzyme that will catalyze the formation of 1 micromole of nicotinamide adenine dinucleotide per minute under conditions of the assay. For protection studies, a compound of formula 1 is added to cultures prior to and/or concurrently with the amyloid-β treatment.
Activity of the compounds of formula 1 is illustrated by a decrease in LDH released into the media (a neurotoxic indicator), as compared to control.
Assay 2
Between five and fifty rats are subjected to 15 minutes of four vessel occlusion to induce global ischemia. A compound of the invention is administered to experimental and control animals prior to, concurrent with and/or up to several hours after 15 minutes of occlusion. Animals are sacrificed 3 days after the ischemic insult and neuronal damage in the hippocampus and striatum is then visually assessed by standard histologic techniques.
Activity of the compounds of formula 1 is illustrated by a decrease in neuronal damage.
Assay 3
Five to fifty women are selected for the clinical study. The women are post-menopausal, i.e., have ceased menstruating for between 6 and 12 months prior to the study's initiation, have been diagnosed with early stage Alzheimer's Disease (AD), are expected to have worsening symptoms of AD within the study period, but are in good general health otherwise. The study has a placebo control group, i.e., the women are divided into two groups, one of which receives the active agent of this invention and the other receives a placebo. The patients are benchmarked as to memory, cognition, reasoning, and other symptoms associated with AD. Women in the test group receive between 50-200 mg of the active agent per day by the oral route. They continue this therapy for 6-36 months. Accurate records are kept as to the benchmarked symptoms in both groups and at the end of the study these results are compared. The results are compared both between members of each group and also the results for each patient are compared to the symptoms reported by each patient before the study began. Activity of the test drug is illustrated by an attenuation of the typical cognitive decline and/or behavioral disruptions associated with AD.
Utility of the compounds of formula I is evidenced by activity in at least one of the above assays.
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This invention encompasses methods for the inhibition of Alzheimer's Disease comprising administering to a human in need thereof an effective amount of a compound of Formula I ##STR1## wherein R 1 and R 3 are independently hydrogen, ##STR2## wherein Ar is optionally substituted phenyl; R 2 is selected from the group consisting of pyrrolidine, hexamethylenemino, and piperidino; or a pharmaceutically acceptable salt of solvate thereof.
The present invention also provides methods of increasing TGF-β expression in the brain, comprising administering to a human in need thereof an effective amount of a compound of formula 1.
The present invention also provides methods of inhibiting the β-amyloid peptide mediated neurotoxicity or inflammatory response associated with Alzheimer's Disease (AD) comprising administering to a human in need thereof an effective amount of a compound of formula 1.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. application Ser. No. 13/255,356, filed Oct. 18, 2011, which is a national stage application under 35 U.S.C. §371 of International Application No. PCT/CN2010/070566, filed Feb. 8, 2010, which in turn claims the benefit of Chinese Applications No. 200910037736.5, filed on Mar. 10, 2009, No. 200910037739.9, filed on Mar. 10, 2009, and No. 200910039687.9, filed on May 22, 2009, the contents of each of which are incorporated to the present disclosure by reference in their entirety.
TECHNICAL FIELD
[0002] The invention is directed to artificial biofilms, in particular artificial dura maters, and to related manufacturing methodology.
BACKGROUND
[0003] Dural defect is a common problem during neurosurgery. Open craniocerebral injuries (industrial, traffic or war-related), tumor invasion, congenital meninges defects or other cranial diseases can lead to defects of the dura mater. Such defects of the dura mater need be repaired timely so as to prevent leakage of the cerebrospinal fluid, encephalocele, and stress from the barometric pressure. Otherwise, it can be life endangering.
[0004] Currently, although there are many dura substitutes, materials used in the substitutes can be generally classified into four types: autologous fascia, allograft, natural or synthetic substance, and xenograft. However, clinical application of these materials unavoidably leads to problems such as high infection rates. According to statistics, the infection rate for craniotomy is 4%; the dura mater made of pig's small intestine mucosa gives an infection rate of 3.4%; and the dura mater manufactured by collagen exhibits an infection rate at 3.8%. Because of the blood brain barrier, once intracranial infection occurs, the encephalic plasma concentration of anti-infection drugs can hardly reach the desired level and control of infection becomes difficult. Also, the existing artificial dura products do not have the capability of supplying medicines into the meninges. Therefore, post-operation infection control is often ineffective.
[0005] Moreover, one of the common reasons for dural repair with dura mater transplant is damages to the meninges due to tumor invasion. More than half of brain tumors cannot be completely removed by surgery and thus chemotherapy is necessary after the surgery. Many chemotherapeutic drugs are toxic and cannot pass the blood brain barrier, so that an effective concentration of the drugs cannot be reached resulting in diminished chemotherapy effects.
[0006] Current artificial dural substitute products usually do not contain therapeutic drugs of interest. For instance, due to the dense structures, the autologous fascia can not be loaded with drugs naturally, and it is difficult to load drugs into allograft or xenograft. However, due to their good malleability, synthetic material-based dural substitutes can be readily loaded with drugs. On the other hand, due to the limitation of loading methods of a drug, it is also not easy to load the drug onto artificial dura mater, and yet allow release of the drug upon transplantation to achieve therapeutic objectives. To date, the common way to load an anti-infection drug onto an artificial dura mater substitute is to soak the substitute with the drug. With this method, most of medicine remains on the surface of artificial dura mater, which is easily lost, making it difficult to achieve controlled release.
[0007] It is apparent, therefore, that current artificial dura mater substitutes have shortcomings Among these are a high infection rate, poor bio-compatibility, incomplete absorbability, and difficulty in loading medicine and controlling the effective release of the medicine.
SUMMARY OF THE INVENTION
[0008] In view of these disadvantages of conventional technology, the present invention provides an artificial dura mater that is characterized by excellent tissue compatibility, ideal anti-adhesion, complete absorption, good mechanical properties, a low infection rate, and a capability to load a variety of therapeutic substances. An artificial dura mater of the invention is comprised of electrospun layers, including at least one hydrophobic electrospun layer. The invention contemplates employing methodology that comprises elctrospinning to prepare such a layer with one or more hydrophobic polymers.
[0009] Suitable hydrophobic polymers can be selected for this purpose from the group consisting of hydrophobic aliphatic polyester, polyetherester, polyorthoester, polyurethane, polyanhydride, polyphosphazene, and polyamino acid, and copolymers and mixtures thereof. Thus, the hydrophobic aliphatic polyester can be at least one selected from the group consisting of polylactic acid, polyglycolide, polycaprolactone, and polyhydroxybutyrate (PHB). The polyetherester can be at least one selected from the group consisting of the polydioxanone (PDO), glycol/lactic acid copolymer, and glycol/butylenes terephthalate copolymer. The polyanhydride is at least one selected from the group consisting of poly(sebacic acid-hexadecanedioi acid anhydride), type-I polyanhydride, type-II polyanhydride, type-III polyanhydride and type-IV polyanhydride.
[0010] The hydrophobic layer-containing artificial dura mater has a strength similar to that of human dura mater. It can seal and protect a person's brain and prevent leakage of the cerebrospinal fluid before a person's own dura mater is regenerated. The hydrophobic layer does not allow cells' migration or attachment and thus can achieve an anti-adhesion effect. In practice, more than one hydrophobic layers can be included to provide different levels of strength
[0011] Furthermore, in the artificial dura mater according to the invention, at least a hydrophilic electrospun layer can be placed on the hydrophobic electrospun layer. The hydrophilic layer can be prepared by electrospinning with one or more types of hydrophilic polymers selected from the group consisting of chondroitine sulfate, heparin, agar, glucan, algin, cellulose, modified cellulose, alginate, starch, gelatin, fibrinogen, silk protein, elastin-mimicry peptide polymer, collagen, chitosan, modified chitosan, hydrophilic polyurethane, polyethylene glycol, polymethylmethacrylate, PHBV, PHBHHx, polyvinyl alcohol, and polylactide, and mixtures thereof.
[0012] When the dura mater is transplanted into the brain, the hydrophobic layer is placed proximate to the brain surface to take advantage of its anti-adhesion capability; whereas the hydrophilic layer, which serves as an excellent nanofiber scaffold for the adhesion, migration, proliferation, and differentiation of cells, is placed distant to the brain. As the hydrophilic layer is prepared with hydrophilic materials of good bio-compatibility, it can effectively enhance the migration and proliferation of stem cells and fibroblasts, and consequently promote the growth of autologous dura mater. In practice, the hydrophilic layer can include more than one layer, so as to satisfy different needs.
[0013] According to one embodiment of the invention, the artificial dura mater also can have a transition layer between the hydrophobic and hydrophilic layers. The transition layer is prepared by an electrospinning method comprising with one or more polymers, and it has hydrophilicity that gradually increases from the side proximate to the hydrophobic electrospun layer to the side proximate to the hydrophilic electrospun layer. The present of the transition layer can improve the affinity between the hydrophobic and hydrophilic layers.
[0014] According to another embodiment of the invention, any one or more of the hydrophobic layers, the hydrophilic layers, and the transition layers can be blended with a cytokine and/or a medicine. Such layers can allow release of the cytokine and/or the medicine into local brain tissue upon transplantation, along with the absorption of the polymers. The cytokine and/or the medicine released to the local brain tissue can then be useful in preventing local infection, adhesion, and/or tumor's recrudesce, or promoting the restoration of autologous dura mater.
[0015] According to yet another embodiment of the invention, the hydrophobic layer and/or the hydrophilic layer can be affixed with the cytokine and/or the medicine. In this regard, the cytokine can be an agent that plays a role in adhesion, migration, proliferation, and/or differentiation of fibroblast. Thus, it can be selected from the group consisting of interleukin, colony stimulating factor, tumor necrosis factor, platelet derived growth factor, basic fibroblast factor, and combinations thereof The cytokine can facilitate the recovery of the defective dura mater.
[0016] A medicine used in accordance with the invention can be one or more selected from the group consisting of antibiotic, hemostat, anti-adhesion agent, and tumor-resistance drug. These medicines can be placed onto the artificial dura mater, based on actual needs. Once the artificial dura mater is transplanted, the medicines are released gradually to local brain tissues, thereby bypassing the blood brain barrier, to achieve therapeutic effects during the degradation of the polymers and regeneration of the dural defect.
[0017] Furthermore, the cytokine and/or medicine can be enclosed in a hydrogel. With the adhesion and fixation effects of hydrogel, the medicine can, depending on the local situation, be uniformly or specifically released. The hydrogel can be prepared with one or more selected from the group consisting of polysaccharide polymer, polypeptide polymer, and synthetic hydrophilic high molecular polymer.
[0018] According to one embodiment of the invention, the hydrophobic electrospun layer of the artificial dura mater is comprised of fibers having a diameter of 50-1000 nM. According to one embodiment of the invention, the hydrophobic electrospun layer has pores of a size of less than 3 μM, whereas the fibers of the hydrophilic electrospun layer have a diameter of 5-200 μM, and a pore size of 20-200 μM. The pore size depends largely on the diameter of the fibers. When the diameter of fiber decreases, the pore size reduces. Thus, by controlling the fiber's diameter, one can control the pore size of the electrospun layer as well. The average diameter of a human cell is 10-50 μM. The meninges mainly consist of the fibroblasts and collagen fibers excreted from fibroblast. Most of the fibroblasts have a diameter of 20-30 μM. The pore size of the hydrophobic layer is less than 3 μM, which can therefore prevent the entry of cells and adhesion between dura mater and brain tissue. The hydrophilic layer has a pore size equal to or larger than the average diameter of cell, which can promote the entry and migration of cell.
[0019] According to further aspect of the invention, a method for preparing an artificial dura mater is also provided, comprising the following steps:
[0020] A) dissolving a hydrophobic polymer into a solvent to obtain a hydrophobic electrospinning solution, wherein the hydrophobic polymer is selected from the group consisting of hydrophobic aliphatic polyester, polyetherester, polyorthoester, polyurethane, polyanhydride, polyphosphazene, polyamino acid and copolymers and the mixtures thereof;
[0021] B) producing, by electrospinning, a film-like (or fleece-like) hydrophobic electrospun layer from the hydrophobic electrospinning solution, thereby preparing the artificial dura mater.
[0022] Further, the hydrophobic aliphatic polyester can be at least one selected from the group consisting of polylactic acid, polyglycolide, polycaprolactone and polyhydroxybutyrate. The polyetherester can be at least one selected from the group consisting of polydioxanone (PDO), glycol/lactic acid copolymer and glycol/butylenes terephthalate copolymer. The polyanhydride can be at least one selected from the group consisting of poly(sebacic acid-hexadecanedioi acid anhydride), type I polyanhydride, type II polyanhydride, type III polyanhydride and type IV polyanhydride.
[0023] The method, applying the principle of electrospinning, forms the artificial dura mater by using a particular polymer. The dura mater can effectively prevent it from adhering to brain tissue.
[0024] To further prevent the adhesion of artificial dura mater to brain tissue, the diameter of fibers can be controlled, such that the pore size of the scaffold is also controlled. In this respect, the artificial dura mater inhibits cell migration. The diameter of fibers of the hydrophobic electrospun layer can be controlled within 50-1000 nM. According to one embodiment of the invention, the pore size of hydrophobic electrospun layer is less than 3 μM.
[0025] In the method described above, at step B), the electrospinning is preformed with a micro-injection pump operated at a velocity of 0.1-5.0 milliliters/hour and a. high voltage generator operated at a voltage of 5-40 kilovolts and with a receiving distance of 5.0-30.0 centimeters.
[0026] To achieve a better effect in clinical therapy, the invention also provides a method, alike to electrospinning, to form a hydrophilic electrospun layer on the hydrophobic layer that comprising the steps of:
[0027] a′) Dissolving a hydrophilic polymer into solvent to obtain a hydrophilic electrospinning solution, wherein The hydrophilic polymer is selected from the group consisting of chondroitine sulfate, heparin, agar, glucan, algin, modified cellulose, alginate, starch, cellulose, gelatin, fibrinogen, silk protein, elastin-mimicry peptide polymer, collagen, chitosan, modified chitosan, hydrophilic polyurethane, polyethylene glycol, polymethylmethacrylate, PHBV, PHBHHx, polyvinyl alcohol polylactide.
[0028] b′) Placing the hydrophilic electrospinning solution, by electrospinning, on the hydrophobic layer to form the hydrophilic electrospun layer.
[0029] The hydrophilic electrospun layer is placed distant to the brain surface, in order to promote migration of cells and regeneration of dural mater. To facilitate the entry of cell, the hydrophilic electrospun layer has fibers with a diameter of 5-200 μM and pores of a size of 20-200 μM.
[0030] In step b′), the formation of hydrophilic electrospun layer, the electrospinning is preformed with a micro-injection pump operated at a velocity of 0.1-20.0 milliliters/hour and a high voltage generator operated at a voltage of 10-40 kilovolts and with a receiving distance of 5.0-30.0 centimeters.
[0031] In the process of electrospinning, generally, the hydrophobic and hydrophilic polymers should be dissolved into appropriate solvents respectively, to form electrospinning solutions. Often, the solvents are volatile organic solvents which include but not limited to methanoic acid, acetic acid, ethyl alcohol, acetone, dimethyl formamide, dimethyl acetamide, tetrahydrofuran, dimethyl sulfoxide, hexafluoro isopropyl alcohol, trifluoroethyl alcohol, dichloromethane, trichloromethane, methyl alcohol, ethyl alcohol, chloroform, dioxane, trifluoroethane, trifluoroacetic acid and mixtures thereof The volatile organic solvents will quickly volatilize during the process of forming electrospun layers, and the final electrospun layers will contain no or little residual organic solvent which can be removed in the later steps. In some cases, water can be used as solvent and removed by oven or natural dryness after the electrospun layers are formed.
[0032] Furthermore, the method for preparing an artificial dura mater provided in present invention further comprises, before the hydrophilic electrospun layer is prepared, forming a transition layer by electrospinning between the hydrophilic and hydrophobic layers, wherein the transition layer has hydrophilicity that gradually increase from the side proximate to the hydrophobic electrospun layer to the side proximate to the hydrophilic electrospun layer. The materials, solvents and electrospinning parameters for preparing the transition layer can be determined based on the actual situation and need. The present of the transition layer can improve the hydrophilicity between hydrophilic and hydrophobic layers.
[0033] In one embodiment of the invention, during the formation of each electrospun layer by electrostatic spinning, a cytokine and/or a medicine can be added to the corresponding electrospinning solutions. With the blending technique, the blended layers of polymers and a cytokine and/or a medicine have a better satisfaction for clinic application and a better therapeutic effect.
[0034] The method for preparing an artificial dura mater provided in present invention further comprises, by bio-printing, forming a distribution of a cytokine and/or a medicine on the hydrophobic electrospun layer and/or the hydrophilic electrospun layer. Bio-printing is a technology for printing a cytokine and/or a medicine onto bio-papers that comprising scaffolds of the hydrophobic electrospun layers and/or the hydrophilic electrospun layers.
[0035] To make the cytokine and/or medicine distribute evenly and point fixed onto the layers, the cytokine and/or medicine can be enclosed into a hydrogel.
[0036] Specifically, the bio-printing comprises the steps of:
[0037] a″) admixing a hydrogel solution with cytokine and/or medicine to form a solution;
[0038] and
[0039] b″) printing the solution onto the hydrophobic electrospun layers and/or hydrophilic electrospun layers using a bio-printing technology.
[0040] The hydrogel solution in the invention comprises the aqueous solutions of polysaccharide polymer, polypeptide polymer synthetic hydrophilic polymer or mixtures thereof Wherein the polysaccharide polymer includes but not limited to starch, cellulose, alginate, hyaluronic acid and chitosan. The polypeptide polymer includes but not limited to collagen, poly-L-lysine and PLGA. The synthetic hydrophilic polymer includes but not limited topolyacrylic acid, polymethacrylic acid, polyacrylamide and N-isopropyl acrylamide.
[0041] The hydrogel is liquid under normal circumstance. At appropriate temperature or under specific conditions, it can turn to gel for a short time by which it has a good adhesion. According to the invention, some hydrogels need a cross-linking agent in participation of reaction. Therefore, the method further comprises, before bio-printing, a pretreatment of the hydrophobic and/or hydrophilic layers with a solution comprising a cross-linking agent. With the pretreatment by the solution comprising a cross-linking, a cross-linking agent is adhere on the layer or layers. After that, a cytokine and/or a medicine will be added into a hydrogel solution, and the mixed solution will be placed into the printer head. While printing, when the hydrogel solution with cytokine and/or medicine reaches the electrospun layers, it solidifies and adheres to the layers.
[0042] In a uniform and stable printing the cytokine and/or medicine can be evenly released. While in a customized printing with varied speeds and locations for an individual case, the cytokine and/or medicine can be released in specific area. The selection of cross-linking agent is based on the type of hydrogel. For instance, while the hydrogel is sodium alginate, the cross-linking agent is calcium chloride; while the hydrogel is fibrinogen, the cross-linking agent is thrombin.
[0043] Compared with the prior arts, the invention exhibits the following advantages:
[0044] (1) Its mechanical properties satisfy the requirement for tensile strength and flexibility, and it is waterproof and anti-adhesion;
[0045] (2) The materials comprising of the membranes is free from poison and harmless to human body, have good compatibility, allow completely absorption after implantation, which avoids the occurrence of tumor or cancer;
[0046] (3) The membrane is not prepared with ingredients derived from biological sources, therefore it can avoid risks such as immune rejection, virus spreading and disease infectiousness;
[0047] (4) The designed double layers can prevent adhesion, promote the growth of autologous cells, which, enable an earlier restoration of dura mater;
[0048] (5) By incorporating the bio-printing technology, the therapeutic substances can be introduced into the membrane and can be released in a controlled manner after the implantation;
[0049] (6) The materials are abundant in source and, cheap in cost and convenient in transportation and store;
[0050] (7) The preparing method comprises easy procedures, costs low, and is easy for industrialized development; and
[0051] (8) The clinical application is simple, and a patient customized application is also available.
[0052] The additional aspects or advantages of the invention will be further given in the following descriptions, and part of them will become obvious through the following descriptions or be understood more easily through the practice.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The above and/or additional aspects and advantages or the additional aspects and advantages of the invention will be more obvious and easier for being understood through the following descriptions in conjunction with the drawings and embodiments, wherein:
[0054] FIG. 1 is an illustration of electrospinning process to prepare the artificial dura mater according to the invention.
[0055] FIG. 2 illustrates of the process for preparing the artificial dura mater according to the invention that combines electrospinning with bio-printing.
[0056] FIG. 3 is an illustration of the artificial dura mater according to the invention comprising the hydrophobic electrospun layer(s).
[0057] FIG. 4 is an illustration of the artificial dura mater according to the invention comprising the hydrophobic electrospun layer and the hydrophilic electrospun layer.
[0058] FIG. 5 is an illustration of the artificial dura mater according to the invention comprising hydrophobic layer, hydrophilic layer and transition layer.
[0059] FIG. 6A is an illustration of the blended artificial dura mater according to the invention comprising hydrophobic electrospun layer and hydrophilic electrospun layer
[0060] FIG. 6B is a magnified illustration of the Zone I of FIG. 6A .
[0061] FIG. 7A is an illustration of the blended artificial dura mater according to the invention comprising hydrophobic electrospun layer, hydrophilic electrospun layer and transition layer.
[0062] FIG. 7B is an enlarged illustration of Zone II of FIG. 7A .
[0063] FIG. 8A is an illustration of the artificial dura mater according to the invention obtained combining with bio-printing technology.
[0064] FIG. 8B is an enlarged illustration of Zone III in FIG. 8A .
[0065] In the figures, the numbers represent in this way.
[0066] 1. Electrospinning sprayer;
[0067] 2. Spinning fibers;
[0068] 3. High voltage power source;
[0069] 4. Receiving device;
[0070] 5. Bio-printer head;
[0071] 6. Vessel;
[0072] 7. Hydrophobic spinning thread;
[0073] 8. Medicine;
[0074] 9. Hydrophilic spinning fibers;
[0075] 10. Cytokine or medicine;
[0076] 11. Spinning fibers of transition layer;
[0077] A. Hydrophobic electrospun layer;
[0078] B. Hydrophilic electrospun layer;
[0079] C. Transition layer.
DETAILED DESCRIPTION
[0080] Now, examples of the invention will be explained in detail. The illustration of examples will be shown in the accompanying drawings, in which the same number represents the same or similar elements. The examples described with reference to the drawings are only illustrations, which intend for explaining the invention and do not limit the invention.
[0081] With reference to FIGS. 1 to 8 , the artificial dura mater and manufacturing methods therefor are described in details below.
[0082] An illustration of electrospinning process to prepare the artificial dura mater is shown in FIG. 1 , the electrospinning sprayer 1 contains the polymer solution, the high voltage power source 3 has its high voltage end connected to the sprayer 1 . The receiving device 4 is in cylinder shape, and can be moved leftwards and/or rightwards, along with the axis of cylinder or the long shaft direction of cylinder. The movement of receiving device 4 can be set with computer program, so that the formed electrospun layer will have equal thickness. In practice, the receiving device can be set as a level-off surface, and through the movement between left and right or fore-and-aft, an even reception can be realized. The receiving device 4 is connected with the low voltage end of high voltage power source 3 , so that there is a large voltage difference between the sprayer 1 and receiving device 4 .
[0083] Before the electrospinning starts, the proper polymer solution for electrospinning should be prepared.
[0084] It is an option to choose the solution of hydrophobic polymer for electrospinning, and such solution is prepared by dissolving a hydrophobic polymer into a solvent. Wherein the hydrophobic polymer includes but not limited to the hydrophobic aliphatic polyester (covering polylactic acid, polyglycolide, polycaprolactone, and polyhydroxybutyrate), polyetherester (such as polydioxanone), polyorthoester, polyurethane, polyanhydride (such as poly(sebacic acid-hexadecanedioi acid anhydride)), polyphosphazene, polyamino acid and mixtures thereof.
[0085] Depending on the design, if the hydrophilic electrospun layer is needed after the hydrophobic electrospun layer is finished, the solution of hydrophilic polymer for electrospinning should be prepared. Wherein the hydrophilic polymer includes but not limited to the chondroitine sulfate, heparin, agar, glucan, algin, modified cellulose, alginate, starch, cellulose, gelatin, fibrinogen, silk protein, elastin-mimicry peptide polymer, collagen, chitosan, modified chitosan, hydrophilic polyurethane, polyethylene glycol, polymethylmethacrylate, PHBV, PHBHHx, polyvinyl alcohol and polylactide. Based on the actual needs, multiple sprayers 1 may be set, in which the hydrophobic polymer solution and the hydrophilic polymer solution are placed respectively. Or, replace the solution in the sprayer 1 after the hydrophobic layer is made.
[0086] The solvent of the solution for electrospinning can be water or a volatile organic solvent which includes but not limited to methanoic acid, acetic acid, ethyl alcohol, acetone, dimethyl formamide, dimethyl acetamide, tetrahydrofuran, dimethyl sulfoxide, hexafluoro isopropyl alcohol, trifluoroethyl alcohol, dichloromethane, trichloromethane, methyl alcohol, ethyl alcohol, chloroform, dioxane, trifluoroethane, and trifluoroacetic acid.
[0087] Once the solution for electrospinning is ready, the parameters should be set. After that, the power is on, and the electrospinning device is activated. As the spinning fibers 2 is spun from the sprayer 1 , the receiving device 4 will move in prescribed procedures, so as to form the uniform electrospun membrane structure.
[0088] The parameters of the process to form the hydrophobic electrospun layer are set as follows: a micro-injection pump operated at a velocity of 0.1-5.0 milliliters/hour and a high voltage generator operated at a voltage of 5-40 kilovolts and with a receiving distance of 5.0-30.0 centimeters. The hydrophobic electrospun layer comprises fibers with a diameter, which can be controlled, ranging from 50 to 1000 μM, and pores of a size of less than 3 μM.
[0089] The parameters of the process to form the hydrophilic electrospun layer are set as follows: a micro-injection pump operated at a velocity of 0.1-20.0 milliliters/hour and a high voltage generator operated at a voltage of 10-45 Kilovolts and with a receiving distance of 5.0-30.0 centimeters. The hydrophilic electrospun layer comprises fibers with a diameter, which can be controlled, ranging from 5 to 200 μM and pores of a size of 20-200 μM.
[0090] In practice, the above procedures can be repeated, so as to form multiple hydrophobic layers and/or multiple hydrophilic layers, as shown in FIG. 3 and FIG. 4 .
[0091] FIG. 3 gives an artificial dura mater with three hydrophobic layers the strength of which is similar to the human's dura mater. As the layers are formed by hydrophobic materials, they are not good for the migration and attachment of cells. Together with the fact that the materials are safe, poison-free and absorbable for human body, they reach the goal of anti-adhesion.
[0092] FIG. 4 gives an artificial dura mater consisting of two hydrophobic layers (A) and three hydrophilic layers (B). When the dura mater is transplanted into brain, the anti-adhesive hydrophobic layers (A) are set near to the brain surface, while the hydrophilic layers (B) are set far from the brain surface, providing a fine nanofibrous scaffold for the adhesion, migration, proliferation and differentiation of cells. As the hydrophilic layers are prepared with hydrophilic materials that offers good bio-compatibility and have larger pore size, which is good for the migration of stem cells and fibroblast, consequently, which is favorable for the growth of autologous dura mater.
[0093] Once the electrospun layers are made, they will be dried in an oven or in natural manner, dependent on varied solution component. When the solvent of an electrospinning solution is a volatile organic solvent, such as hexafluoro isopropyl alcohol, the procedure for dryness can be omitted since the solvent has completely volatilized while the spinning fibers 2 are spun to the receiving device 4 along with a voltage difference.
[0094] As the hydrophobic layer is very different from the hydrophilic layer in the terms of hydrophilicity, the structural stability is not easy to be kept in the application. To solve such problem and increase the hydrophilicity between the two, a transition layer can be applied. t The transition layer has a hydrophilicity that gradually increases from the side proximate to the hydrophobic electrospun layer to the side proximate to the hydrophilic electrospun layer. In practice, the electrospinning solution of the transition layer can comprise one or more polymers and corresponding solvent which are determined based on the requirement of hydrophilicity. Then, the solution is placed into the sprayer, by the method the as above, to prepare the transition layer before the hydrophilic layer. The parameters of the process to form the transition layer are set as follows: a micro-injection pump operated at a velocity of 0.1-5.0 milliliters/hour and a high voltage generator operated at a voltage of 5-40 kilovolts and with a receiving distance of 5.0-30.0 centimeters.
[0095] The artificial dura mater with transition layer is illustrated in FIG. 5 . In the figure, the hydrophobic layer is of two layers, and the hydrophilic layer is of three layers. Between the hydrophobic layers (A) and the hydrophilic layers (B), there is a transition layer of two layers (C), the one, proximate to the hydrophobic layers (A) has a weaker hydrophilicity than the other proximate to the hydrophilic layers.
[0096] Furthermore, to realize the addition of cytokine and/or medicine into the artificial dura mater, a blending electrospinning can be adopted. Specifically, a cytokine and/or a medicine can be blended into any one or more layers of the hydrophobic, hydrophilic and transition layers. A cytokine and/or medicine should be put into a corresponding solution. After that, the electrospinning is made and the cytokine and/or medicine will be blended into the spinning fibers 2 as the spinning fibers are formed. The membrane structure will be formed on the receiving device 4 . Likewise, this procedure can be repeated. The cytokine and/or medicine added each time can be the same or different. The acquired artificial dura mater is shown in FIG. 6 . In FIG. 6A , a hydrophobic layer is of a two-layer structure and a hydrophilic layer is of a three-layer structure. In FIG. 6B , a hydrophobic spinning fiber 7 contains a medicine 8 , and a hydrophilic spinning fiber 9 is blended with a cytokine 10 .
[0097] FIG. 7A has two transition layers C based on FIG. 6 . One of them proximate to the hydrophobic layer A, has a weaker hydrophilicity than that proximate to the hydrophilic layer B. From FIG. 7B , the hydrophobic spinning fiber 7 is blended with a medicine 8 , and the hydrophilic spinning fiber 9 is blended with a cytokine 10 , the spinning fibers of two transition layers 11 is respectively blended with medicine 8 and cytokine 9 .
[0098] Besides, the invention provides a method that combines electrospinning and bio-printing to prepare artificial dura mater. The bio-printing is an emerging technology, and just have been developed and applied in biomedical fields in recent years. This technology utilizes a special cell solution or a biological active solution as the “bio-ink” and as designed, prints precisely on the spot of a specific substrate (termed as “bio-paper”) that can be degraded in the human body. After printing, the bio-papers will be stacked in certain sequence. As the printing technology is used, the bio-ink consisting of cells and/or cytokine can be precisely placed to the designed areas. The bio-papers, if stacked in particular way, will form the three dimensional structure.
[0099] The specific implementation is given in FIG. 2 . Based on the device given in FIG. 1 , the bio-printer head 5 is set, and such head can be obtained by modifying the present commercial inkjet printer as the method, for example, disclosed in U.S. Pat. No. 7,051,654. The head contains a cytokine and/or a medicine. The printing manner and printing position can be set through the computer program in advance. The specific printing procedures can base on the current technologies.
[0100] In accordance with one embodiment of the invention, the cytokine and/or medicine can be enclosed in hydrogel. The hydrogel solution can be aqueous solution of polysaccharide polymer, polypeptide polymer or synthetic hydrophilic polymer. The polysaccharide polymer includes but not limited to the starch, cellulose, alginate, hyaluronic acid and chitosan. The polypeptide polymer includes but not limited to the collagen, poly-L-lysine and PLGA. The synthetic, hydrophilic polymer includes but not limited to polyacrylic acid, polymethacrylic acid, polyacrylamide and N-isopropyl acrylamide. The hydrogel is liquid in normal circumstances and becomes gel at certain temperature or under specific conditions. With which, the hydrogel possesses good adhesion, which can make a cytokine and/or a medicine evenly or definitely distribute on the electrostatic spinning layer.
[0101] The procedures of bio-printing with hydrogel are as follows: 1) Put the cytokine and/or medicine, prepared and blended with liquid hydrogel, into the bio-printer head 5 . 2) after the electrospun layer is formed, Print on the electrospun layer with jet printer as per the preset program; based on the choice of hydrogel, apply proper conditions to make the hydrogel quickly become gel/jelly that, by offering good adhesion, adhere the cytokine and/or medicine enclosed to the electrospun layers. 3) Set even and uniform distribution of bio-ink and form the artificial dura mater as shown in FIG. 8A , in which, each of hydrophobic layers is printed with a layer of medicine and each of hydrophilic layers is printed with a layer of cytokine. As shown in enlarged FIG. 8B , the film prepared with bio-printing is different from that prepared with blending. A cytokine and/or a medicine are applied on the surface of layers that is formed by the hydrophobic spinning fiber 7 and/or the hydrophilic spinning fiber 9 . When such dura mater is transplanted into human body, the cytokine and/or medicine can be evenly released. 4) If necessary, set the concentrated distribution on certain points and make the cytokine and/or the medicine printed into particular areas. When such dura mater is transplanted to the human body, the cytokine and/or the medicine can be mostly released to the wanted specific areas.
[0102] The solidification of some hydrogels needs a cross-linking agent to assist. In this case, a bio-printing in the utilization of hydrogel has the following procedures: 1) Put a certain amount of cross-linking agent into the vessel 6 . Once the electrospinning starts, the receiving device 4 , moving along with the axis or between left and right, will contact the agent, and the formed electrospun layers will adhere with some cross-linking agent 2) Make the bio-printing as given above. When the liquid hydrogel inside the head 5 contacts the cross-linking agent on the electrospun layers, the hydrogel quickly turns to gel/jelly and enables the cytokine and/or medicine enclosed to adhere to the electrospun layers. The selection of cross-linking agent depends on the kind of hydrogel. For instance, when the hydrogel is sodium alginate, the cross-linking agent is calcium chloride; when the hydrogel is fibrinogen, the agent is thrombin.
[0103] According to the one embodiment of the invention, the solution of hydrophobic polymer can be hydrophobic poly(L-lactide) (PLLA) and ε-caprolactone dissolved to hexafluoro isopropyl alcohol or dichloromethane, the ratio of the two polymers can be 50:50, 30:70 or 70:30. As a copolymer, the number-average molecular weight is 150,000-500,000. When blending is needed, the hydrophobic solution can be added with 0.01-3% antibiotic solution and/or with 0.001-3% medicine for hemostasis and anti-adhesion. Together with the solution of poly(L-lactide) (PLLA) and ε-caprolactone, the final solution will be obtained.
[0104] According to another embodiment of the invention, the solution of hydrophilic polymer can choose hydrophilic polyurethane plus natural gelatin, chondroitine sulfate or polyethylene glycol as solvent(s). The mass ratio is 20-80:80-20. The spinning solution accounts for 3-15% of total weight. In blending, the solution of hydrophilic polymer can be added with a solution of basic fibroblast factor, and make the concentration of cytokine of 0.001-0.5%.
[0105] A medicine added in blending or bio-printing can choose, in accordance with the actual situation, antibiotic or drug for hemostasis or anti-adhesion. In the transplantation of dura mater due to tumor excision, the drugs for chemotherapy of brain tumor can be added.
[0106] An antibiotic includes but not limited to the cephalosporin, ampicillin, spiramycin, sulfonamides and quinolones. The first choice is ceftriaxone sodium. As meninges surgeries often need to open the skull and at present, the intracranial infection is often bacterial mainly comprising staphylococcus aureus, streptococcus, pneumococcus, escherichia coli, salmonella and pseudomonas aeruginosa. The commonest virus is staphylococcus aureus. According to the clinical reports, the ceftriaxone sodium offers better therapy effect.
[0107] The anti-tumor medicine includes but not limited to nimustine, semustine, liposome doxorubicin, dactinomycin D and vincristine. The vincristine is first choice.
[0108] A medicine for hemostasis or anti-adhesion can speed up the healing of wound and prevent the occurrence of adhesion. Such medicine includes but not limited to the hemostasis factor (which makes the material own the function of hemostasis), the inhibitor of collagen synthase (such as tranilast and pemirolast, which inhibit the revival of collagen), the anti-coagulation drug (such as dicoumarolum, ehparin sodium and hirudin), the anti-inflammatory drug (such as promethazine, dexamethasone, hydrocortisonum, prednisolone, ibuprofen and oxyphenbutazone), the calcium channel blocker (such as diltiazem hydrochloric, nifedipine and verapamil hydrochloride), the cell growth inhibitor (such as fluorouracil), the hydrolase (such as hyaluronidase, streptokinase, urokinase, pepsin and tPA) and the oxidation reductant (such as methylene blue).
[0109] According to an embodiment of the invention, in blending, the electrospinning solution is added with a cytokine and/or a medicine in this formula: the basic fibroblast growth factor accounting for 0.001-0.05% of electrospinning solution weight, the ampicillin accounting for 3% of electrospinning solution weight, the hemostasis factor accounting for 0.001-0.05% of electrospinning solution weight. In a meninges restoration operation due to brain tumor, the nimustine accounting for 0.01-5% of the weight can be added.
[0110] The obtained artificial dura mater should be rinsed, sterilized, packaged and stored.
EXAMPLE 1
[0111] Poly(L-lactide) (PLLA) and ε-caprolactone, in the mass ratio of 50:50 and with number-average molecular weight of 260,000, are dissolved into a solvent of hexafluoro isopropyl alcohol to form a hydrophobic electrospinning solution. Put the solution into the sprayer of electrospinning. The micro-injection pump is operated at a velocity of 5 milliliter/hour; the high voltage generator is is operated at a voltage of 30 kilovolts and a receiving distance of 20 centimeters. The fibers are received to form a membrane structure and have a diameter in the average of 300 nm. After the receiving process is completed, the spinning device is closed.
[0112] The artificial dura mater acquired is rinsed for five times with ethyl alcohol and distilled water. The dura mater, then, is packaged in vacuum after freeze dry. After sterilization with 25 kGy cobalt-60, the dura mater is stored at minus 20° C.
EXAMPLE 2
[0113] The preparing method is the same as which of the example 1.
[0114] The hydrophilic solution for electrospinning choose poly ethanedioic acid and chondroitine sulfate, in the mass ratio of 70:30 and the mass fraction of spinning liquid is 9%.
[0115] The electrospinning device is activated, and a hydrophilic electrospun layer is formed on the hydrophobic layer already formed in Embodiment 1. The receiving distance is 11 centimeters, the voltage is 20 kilovolts, and the acquired hydrophilic layer comprises fibers in the average with a diameter of 10 μm.
[0116] The rinse and store are the same as those in Embodiment 1.
EXAMPLE 3
[0117] The hydrophobic electrospun layer is prepared in the same manner with that in Embodiment 1.
[0118] The transition layer adopts a polymer solution of polyurethane and hyaluronic acid in the mass ratio of 70:30 and has a mass fraction of 10%. The spinning is activated with a receiving distance of 11 centimeters and a voltage of 20 kilovolts. The fibers have a diameter at average of 5 μm. On the hydrophobic layer, the transition layer is made.
[0119] Then, on the transition layer, the hydrophilic layer is spun, in the same manner as that in Example 4. After that, the spinning is stopped.
[0120] The rinse and store are the same as them in Example 1.
EXAMPLE 4
[0121] (1) prepare the hydrophobic electrospun layer: Choose the hydrophobic polycaprolactone and a mixed solvent of chloroform or methyl alcohol in a ratio of 1:1. Add with ceftriaxone sodium, at a concentration of 1%. Get the uniform solution.
[0122] Add the above solution into the sprayer for electrostatic spinning, and perform the electrospinning with a micro-injection pump operated at a velocity of 0.8 milliliters/hour and a high voltage generator operated at a voltage of 12 kilovolts and with a receiving distance of 15 centimeters. Obtain the fibers in membrane structure. The fibers of the hydrophobic electrospun layer have a diameter of 600 nanometers.
[0123] Close the spinning device.
[0124] (2) prepare the hydrophilic electrospun layer: Adopt the hydrophilic silk protein and natural gelatin in the ratio of 20-80:80-20 and have the mass fraction of spinning liquid at 9%.
[0125] Prepare the solution of basic fibroblast factor. Mix the solution with the above mentioned electrospinning solution evenly, and have the final concentration of cytokine to be 0.001%, the receiving distance to be 10 cm, and the voltage to be 20 KV. Start the electrospinning, and form the hydrophilic layer on the hydrophobic layer formed already. The average diameter of fibers from the hydrophilic layer is in the level of micron.
[0126] The rinse and store are the same as them in Example 1.
EXAMPLE 5
[0127] (1) prepare the hydrophobic electrospun layer: Select the hydrophobic polycaprolactone and a mixed solvent of chloroform and methyl alcohol in ratio of 1:1. Blend with vincristine at the concentration of 100 ng/ml, and get the uniform solution.
[0128] Add the above solution into the sprayer for electrospinning, adjust the velocity of micro-injection pump to be 0.8 ml per hour, the voltage of high voltage generator to be 12 KV, and the receiving distance of receiving device to be 15 cm, and obtain the fibers in membrane structure. The fibers of the hydrophobic electrospun layer have a diameter of 600 nanometers.
[0129] Close the spinning device.
[0130] (2) prepare the transition layer: Choose polyurethane and hyaluronic acid in the mass ratio of 70:30. Have the mass fraction of spinning solution at 10%. Blend with ampicillin at concentration of 3%. The uniform solution is form.
[0131] Start the spinning. Spin the transition layer on the hydrophobic layer already formed.
[0132] The receiving distance is 11 centimeters, the voltage is 20 kilovolts, and the average diameter of fibers is 5 μm.
[0133] Close the spinning device.
[0134] (3) prepare the hydrophilic electrospun layer: Adopt the hydrophilic silk protein and natural gelatin in the ratio of 20-80:80-20 and have the mass fraction of spinning solution at 9%. Blend with ampicillin solution at a final concentration of 3%.
[0135] Activate the spinning device, adjust the receiving distance to be 10 cm, and spin the hydrophilic layer on the transition layer already formed. The average diameter of fibers should be in the level of micron.
[0136] The rinse and store are the same as them in Example 1.
EXAMPLE 6
[0137] (1) prepare the hydrophobic electrospun layer with bio-printing:
[0138] The hydrophobic solution selects the hydrophobic poly(L-lactide) (PLLA) and ε-caprolactone, in a mass ratio of 50:50, as copolymer with a number-average molecular weight of 260000, dissolved into the hexafluoro isopropyl alcohol.
[0139] The cross-linking agent selects 0.1M calcium chloride solution.
[0140] The hydrogel containing a cytokine adopts an alginate solution of hemostasis factor. The hemostasis factor has a concentration of 10 ppm in mass in the cytokine alginate solution.
[0141] The solution with 0.1 M calcium chloride should be placed into the cell petri dish with a diameter of 150 mm. The co-receiver share by the spinning device and bio-printing is placed into the petri dish. In forming of an electrospun layer, the receiving device should contact with the solution in petri dish. The printer head is fixed below the electrospinning needle which is inside the spinning device box, which offers a function of fixed-point print on specific area with hemostasis factor. The prepared cytokine alginate solution is put into the cartridge of jet printer. In this embodiment, the cartridge is HP51626A.
[0142] The hydrophobic electrospinning solution is placed into the sprayer for spinning After that, adjust the velocity of micro-injection pump to be 5 milliliters/hour, the voltage of high voltage generator to be 30 kilovolts, and the receiving distance of receiving device to be 20 centimeters. The fiber is received in membrane structure. The spinning lasts for 20 minutes before the spinning device is closed.
[0143] The hydrogel solution containing the cytokine is printed on the nano-bionic scaffold with jet printer. Once the hydrogel is solidified, the hydrophobic electrospun layer with cytokine by bio-printing is acquired.
[0144] (2) prepare the hydrophilic electrospun layer with bio-printing:
[0145] An electrospinning solution, a hydrogel solution with medicine and the cross-linking agent solution are prepared.
[0146] Polyglycol and chondroitine sulfate, as hydrophilic materials, in the mass ratio of 70:30 are chosen. The spinning solution has the mass fraction of 9%. The cross-linking agent solution is the 0.1M calcium chloride solution.
[0147] The hydrogel solution containing a cytokine adopts the alginate solution with basic fibroblast factor. The basic alginate solution has the basic fibroblast factor at the concentration of 100 ppm.
[0148] The parameters are set as follows: Adjust the velocity of micro-injection pump to be 0.8 milliliters/hour, the voltage of high voltage generator to be 20 kilovolts and the receiving distance of receiving device to be 11 centimeters. Other preparing procedures are the same as those in first step above. After the hydrophilic fiber is received in membrane structure, by bio-printing, the hydrogel solution containing the basic fibroblast factor is printed to the nano-bionic scaffold. Once the hydrogel is solidified, the hydrophilic electrospun layer with cytokine by bio-printing is acquired.
[0149] The rinse and store are the same as those in Example 1.
EXAMPLE 7
[0150] (1) The preparation of hydrophobic electrospun layer with bio-printing is the same as described in Example 6.
[0151] (2) prepare the transition layer by bio-printing
[0152] The electrospinning liquid solution of transition layer is comprises the polyurethane and the hyaluronic acid in the mass ratio of 70:30. The mass fraction of the spinning solution is 10%. The blended ampicillin is in the concentration of 3%.
[0153] The cross-linking agent solution is the 0.1M calcium chloride solution.
[0154] The hydrogel solution with cytokine is an alginate solution of hemostasis factor, and the mass percentage of the hemostasis factor is 10 ppm.
[0155] The parameters are adjusted in this way as follows: The velocity of micro-injection pump is 4 milliliters/hour, the voltage of high voltage generator is 20 kilovolts, and the receiving distance is 11 centimeters. The other procedures are the same as the above procedures. The fiber is received in membrane structure. The hydrogel solution containing the cytokine will be printed on the transition layer. After the hydrogel is solidified, the hydrophobic electrospun layer with cytokine by bio-printing is obtained.
[0156] (3) The preparation of hydrophilic electrospun layer with bio-printing is the same as described in Example 6.
[0157] The rinse and store are the same as those described in Example 1.
EXPERIMENTAL EXAMPLE 1
[0158] The dura mater obtained from Example 1 is applied to dog for the animal experiment, while the control is a commercialized, clinical applicable heterogenic meninges repairing product. Three healthy dogs are chosen, either male or female, in the weight between 10 and 15 kg, and under observation for two to three months. The dogs chosen in the experiment are under general anesthesia. Their skulls are opened at both left and right sides. Their dura maters are surgically removed, and the defects of dura maters and injuries of brain tissue appear. Then, the dura maters obtained from the Embodiment 1 and the control, respectively, are implanted for repairing the dural defects at the left and right sides of the dog's brain. After operation, the dogs are feed normally as usual and observed periodically. The specimen is taken from the implanted area at the end of each observation period. In the end of the observation period, the skulls of the dogs are exposed by the way described above after general anesthesia. Expose and separate the outer surface of the repairing material. To retrieve the samples, these dogs are sacrificed by administration of an intravenous injection of air. The skulls are opened surgically. The implants and surrounding tissue are taken out. The retrieved samples are inspected carefully with details including the appearance, characters, its relation to the surroundings, cyst, callosity, as well as the adhesion between its inner surface and brain tissue. The specimen is stored in a bottle and treated and fixed with Formalin solution. Label the bottle. One week later, take out a local tissue; embed with paraffin section and histological stain with HE.
[0159] Several days after implantation, the three dogs recover well, and incisions are healed well with no obvious secretion. The dogs eat and drink normally as well as their outdoor activities are normal without any obvious movement malfunction. Three months post-implantation, the three dogs are sacrifice by an intravenous injection of air. After sacrifice, taking the surgical site as center, the specimen is cut from one centimeter outer the operation site, and it includes the repair material, the surrounding dura mater and part of brain tissue. After the specimen is taken, separate the skull and meninges in order. It is found that the meninges, where dura mater transplanted, are formed completely; the transplanted material has been replaced by fibrous tissue, and has connected tightly with the native meninges without border. The internal surface of the newly-formed meninges at transplantation site is free from adhesion with the brain tissue, and the surface of corresponding brain tissue is smooth and free from adhesion to the implant. While, in the implanted site of the control samples, the transplanted material has not yet degraded and exist a few of adhesion at the transplantation site to the internal surface of meninges.
EXPERIMENTAL EXAMPLE 2
[0160] The dura mater prepared in the Example 2 is now applied for the dog experiment. Five dogs are in weight of 15-20 kg, 1.5-2-year-old, and either male or female. They are in general anesthesia through the intramuscular injection of ketamine. After anesthesia and shave, the animals are placed on the operation table in lateroabdominal position. The disinfection is made with 2% iodine and 75% alcohol. The animals' heads are opened surgically in lengthwise direction. Stripper is used to separate the periosteum of the skull, and the two top skull plateaus are exposed. The high-speed driller is used to open the skull. The two skull windows at vertex are formed, and two rectangular dura maters in size of 3 cm×3 cm at the top of head are cut off with the scissors. Finally the top dura mater defects are made for the following implantation with artificial dural mater and control. On the exposed brain surface, the electrocoagulation is applied to make 6 injury points in the size of 1 mm×1 mm. Then, the artificial dura mater manufactured in Embodiment 2 is trimmed to the same shape and size as those of the dural defect and loaded into the defect. The hydrophobic layer is toward the brain surface, and the sutures is made with the 4/0 thread in the interval of 4 mm, to repair the dural defect of dogs. The round needle and 4/0 thread are used for suture of muscle. The commercialized, clinically applicable, animal material based dural repair product is applied as a control. After operation, the dogs are feed normally as usual and observed periodically. The animals recover well, and incisions are healed well. No obvious leakage of cerebrospinal fluid or occurrence of epilepsy is found. The dogs eat and drink normally as well as their outdoor activities are normal without any obvious movement malfunction, and they survive to the expected longevity.
[0161] Eighteen months post-implantation, the dogs are sacrificed and the specimen is taken at the surgical site, and it includes the artificial dura mater, the surrounding dura mater, and part of the surrounding brain tissue. After carefully observe the specimen, we can see that the connection between the artificial dura mater and native dura mater is tight and smooth, without clear boundary, healed well, besides, and with thread seen only. The native dura mater does not show any hyperaemia, hemorrhage or other rejection reaction. While, the results of the control show that the implant material is not yet degraded, and at the implanted site, the inner surface of meninges adheres to brain tissue to some degree.
EXPERIMENTAL EXAMPLE 3
[0162] The artificial dura mater obtained from Example 3 is now under the experiment with New Zealand rabbit.
[0163] The animals under experiment are opened in the skulls, and the defect of dura mater and injury of brain tissue are made surgically. Then, the artificial dura mater is used to repair the defect. After the operation, the rabbits are feed normally as usual and observed periodically. These animals recover well. Eighteen months post-implantation, the rabbits are sacrificed and the specimen is taken at the surgical site. The specimen includes the artificial dura mater, surrounding dura mater and part of the surrounding brain tissue. When observe the specimen carefully, it is seen that the epithelial cells cover the inner surface of the dura mater; under the epithelium, fibrous tissue is formed, fibroblast progenitor cells proliferate, and collagen fibers are increased. All of these result in the formation of new vascularized tissues, in-growth of native dura mater, degradation of the implant material, deduction of total mass of the implant, and generation of rich capillary networks. In the interface of old and new tissues, no neutrophil, lymphocyte or other cell reaction for inflammation is found, and no cyst wall is formed. The arachnoid mater and brain tissue are normal.
EXPERIMENTAL EXAMPLE 4
[0164] The dura mater obtained from Example 4 is now applied to the dog experiment, and the method is the same as Experimental example 2.
[0165] Fifteen months post-implantation, the dogs are sacrificed and the specimen is taken at the surgical site. The specimen includes the artificial dura mater, surrounding dura mater, and part of the surrounding brain tissue. After carefully observe the specimen, it is seen that the connection between the artificial dura mater and native dura mater is tight and smooth, without clear boundary, completed cured, and with thread seen only. The native dura mater does not show hyperaemia, hemorrhage or other rejection reaction.
EXPERIMENTAL EXAMPLE 5
[0166] The dura mater obtained from Example 5 is now applied to the New Zealand rabbit experiment, and the control is the commercialized, clinically applicable, animal materials based dura mater product as the repair material.
[0167] The method is the same as Experimental example 3. Fifteen months post-implantation, the rabbits are sacrificed and the specimen is taken at the surgical site. When observe the specimen carefully, it is seen that the epithelial cells cover the inner surface of the dura mater; under the epithelium, fibrous tissue is formed, fibroblast progenitor cells proliferate, and collagen fibers are produced. All of these result in the formation of new vascularized tissues, in-growth of native dura mater, degradation of the implant material, deduction of total mass of the implant, and generation of rich capillary networks. In the interface of old and new tissues, no neutrophil, lymphocyte or other cell reaction for inflammation is found, and no cyst wall is formed. The arachnoid mater and brain tissue are normal. While, the results with the control show that the implant material is not yet degraded, and at the implanted site, the inner surface of meninges adheres to brain tissue to some degree.
EXPERIMENTAL EXAMPLE 6
[0168] The dura mater obtained from Example 6 is now applied to the dog experiment, and the method is the same as Experimental example 2.
[0169] Twelve months post-implantation, the dogs are sacrificed and the specimen is taken at the surgical site. The specimen includes the artificial dura mater, surrounding dura mater, and part of the surrounding brain tissue. When observe the specimen carefully, it is seen that the connection between the artificial dura mater and native dura mater is tight and smooth, without clear boundary, completed cured, and with thread seen only. The native dura mater does not show hyperaemia, hemorrhage or other rejection reaction.
EXPERIMENTAL EXAMPLE 7
[0170] The dura mater obtained from Example 7 is now applied to the New Zealand rabbit experiment.
[0171] The method is the same as Experimental example 3. Twelve months post-implantation, the rabbits are sacrificed and the specimen is taken at the surgical site. When observe the specimen carefully, it is seen that the epithelial cells cover the inner surface of the dura mater; under the epithelium fibrous tissue is formed, fibroblast progenitor cells proliferate, and collagen fibers are increase. All of these result in the formation of new vascularized tissues, in-growth of native dura mater, degradation of the implant material, deduction of total mass of the implant, and generation of rich capillary networks. In the interface of old and new tissues, no neutrophil, lymphocyte or other cell reaction of inflammation is found, and no cyst wall is formed. The arachnoid mater and brain tissue are normal.
[0172] Notwithstanding the embodiments have been given and described, the person skilled in the field can, without deviation from the principle and theory, can make the variation, modification, replacement and change of these embodiments, as given in the invention scope and right claims.
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Disclosed are an artificial dura mater and manufacturing method thereof. The artificial dura mater includes electrospun layers prepared by electrostatic spinning, at least one of which is a hydrophobic electrospun layer. Further, above the hydrophobic electrospun layer, there can be at least one hydrophilic electrospun layer. A transition layer can be further included between the hydrophobic and the hydrophilic electrospun layers. Additionally, cytokines and/or medicines can be affixed to either or both of the hydrophobic and the hydrophilic electrospun layers, by way of bio-printing. The disclosed artificial dura mater shows good biocompatibility, enhances dural tissue regeneration, achieves excellent repairing effects, prevents adhesion, allows complete absorption, has good mechanical properties, ensures low infection rates, and can be loaded with therapeutic agents.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/381,632 filed Dec. 29, 2011, now allowed, which is a National Phase of PCT/US 09/052263 which claims benefit of U.S. Provisional Patent Application No. 61/084,827 filed Jul. 30, 2008, which are hereby incorporated by reference as part of the present disclosure.
FIELD OF THE INVENTION
The present invention relates to a method for non-invasively measuring intracranial pressure.
BACKGROUND OF THE INVENTION
Generally, mammals such as humans have a constant intracranial volume of blood and, therefore, a constant intracranial pressure (“ICP”). A variety of normal and pathological conditions, however, can produce changes in intracranial pressure. Elevated intracranial pressure can reduce blood flow to the brain and in some cases can cause the brain to become mechanically compressed, and ultimately herniate. The most common cause of elevated intracranial pressure is head trauma. Additional causes of elevated intracranial pressure include, but are not limited to shaken-baby syndrome, epidural hematoma, subdural hematoma, brain hemorrhage, meningitis, encephalitis, lead poisoning, Reye's syndrome, hypervitaminosis A, diabetic ketoacidosis, water intoxication, brain tumors, other masses or blood clots in the cranial cavity, brain abscesses, stroke, ADEM (“acute disseminated encephalomyelitis”), metabolic disorders, hydrocephalus, and dural sinus and venous thrombosis. Because changes in intracranial pressure require constant monitoring and possible surgical intervention, the development of techniques to monitor intracranial pressure remains an important goal in medicine. U.S. Pat. No. 6,875,176.
Conventional intracranial pressure monitoring devices include: epidural catheters; subarachnoid bolt/screws; ventriculostomy catheters; and fiberoptic catheters. All of these methods and systems are invasive, and require invasive surgical procedures by highly trained neurosurgeons. Moreover, none of these techniques are suited to rapid or regular monitoring of intracranial pressure. In addition, all of these conventional techniques measure ICP locally, and presumptions are made that the local ICP reflects the whole brain ICP. The teachings of U.S. Pat. No. 6,875,176 illustrate these limitations of the existing methods.
There are no widely accepted methods of non-invasively measuring ICP. Clinically, however, the development of an effective means of measuring ICP is very important as ICP can be predictive of clinical outcome, and can lead to altered, more effective therapy. For example, after traumatic brain injury, intracranial pressure tends to rise requiring both prompt recognition and treatment. Zanier et al. Critical Care 11:R7 (“2007”). The existing standards in measuring ICP require direct, invasive measurement involving the placement of epidural transducers or intraventricular or intraparenchymatous catheters. Frank et al. Zentralbl Neurochir 61(“4”): 177-80 (“2000”). The use of invasive methods increases the risk of injury from infection, bleeding or surgical mishap. Czosnyka et al. J. Neurol. Neurosurg. Psychiatry 75: 813-821 (“2004”).
A variety of different techniques for noninvasively measuring ICP have been explored, including, measuring otoacoustic emissions (“Frank et al. Zentralbl Neurochir 61(“4”): 177-80 (“2000”)”), and ultrasound with a transcranial Doppler (Ragauskas et al. Innovative non-invasive method for absolute intracranial pressure measurement [online], [retrieved on Jul. 30, 2008]. Retrieved from the Internet <URL: http://www.neurosonology.org/bern2002/abs_12.html>).
For example, U.S. Pat. No. 6,702,743 (“the '743 patent”) discloses a non-invasive means of measuring ICP. An ultrasound probe is placed on the head of a patient, and is then used to generate an ultrasound pulse which propagates through the skull and brain of the patient. The ultrasound pulse is reflected off of the skull and soft tissue lying in a path perpendicular to the ultrasound probe. A portion of a generated Echo EG signal is then selected, and the Echo EG signal is integrated over the selected portion to generate an echopulsograph (“EPG”) signal. However, in order to determine ICP using the methods of the '743 patent, the operator must manually select, or “gate” a portion of the EPG and then review the EPG waveforms at each gate to determine which provides the optimal EPG waveform for a site of interest in the brain.
We have developed a novel method to noninvasively measure ICP and more generally brain elasticity that requires no manual review of EPG waves by a technician. ICP is determined using an algorithm coupled on a simulated artificial neural network (“SANN”) that calculates ICP based on a determination of a set of interacted ultrasound signals (“IUSs”) generated from multiple ultrasound pulses. The methods and systems of the present invention are capable of rapidly determining ICP without manual review of EPG waves.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a non-invasive technique for measuring ICP based upon the analysis of reflected ultrasound signals represented in echopulsograph (“EPG”) form.
ICP is measured by first transmitting an ultrasound pulse of about at least 1 MHz into the cranium of a patient. This ultrasound pulse is then reflected by various structures in the cranium, including the walls of the third ventricle. The reflected signals are received by a transducer, and a package of information is generated.
The invention obtains multiple ultrasound signals of a patient. Since the state of the walls of the third ventricle are constantly changing due to blood flow into and out of the brain (“systole and diastole”), the computer is able to compare each signal to locate the region of the third ventricle based upon deviations in the respective waveforms.
Once the third ventricle is located, data points along the portion of the wave inside the third ventricle are used to calculate ICP. The ICP value is calculated from an algorithm that correlates the sampled values with ICP data derived from patients with known ICP values. The calculation is completed automatically by the computer once the system has been compared or trained by reference to known ICP values.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a block diagram of the preferred apparatus for transmitting and receiving ultrasound waves and training the artificial neural network.
FIG. 2 depicts a flow chart of the intracranial pressure monitoring system.
FIG. 3 depicts one full ultrasound reflected signal (“USRS”).
FIG. 4 depicts the correlation between parts of the USRS and the parts of brain.
FIG. 5 depicts flow chart of inputting the USRS data points into the neural network and the algorithm to obtain an ICP value.
FIG. 6 depicts examples of the specific EPG points used as input.
FIG. 7 is a side-by-side comparison a QRS complex and ultrasound signals.
FIG. 8 depicts a flow chart of the back propagation method used in the training process.
FIG. 9 depicts an example of how the training process creates the range of measurable ICP values.
FIG. 10 depicts an embodiment of the hardware for the training process.
DETAILED DESCRIPTION
The present invention is directed to a method for non-invasively measuring ICP and more generally the elasticity of tissues within or proximate to various organs or cavities within the body. In one embodiment, ICP is determined by insonating the cranial cavity using a transcranial Doppler signal. First, the position of the anterior and posterior walls of the third ventricle are identified, and an ICP wave plot established. The ICP is then calculated from the ICP wave using a neural network. More generally, the methods and systems of the present invention may be used for measuring tissue elasticity in a variety of different tissues.
In one embodiment of the invention, the methods and systems of the present invention use ultrasonic probes. Such probes may be constructed from one or more piezoelectric elements activated by electrodes, for example, from lead zirconate titanate (“PZT”), polyvinylidene diflouride (“PVDF”), PZT ceramic/polymer composite, and the like. The electrodes are connected to a voltage source, a voltage waveform is applied, and the piezoelectric elements change in size at a frequency corresponding to that of the applied voltage. When a voltage waveform is applied, the piezoelectric elements emit an ultrasonic wave into the media to which it is coupled at the frequencies contained in the excitation waveform. Conversely, when an ultrasonic wave strikes the piezoelectric element, the element produces a corresponding voltage across its electrodes. The invention may be practiced using any of numerous ultrasonic probes that are well known in the art.
FIG. 2 provides an overview of the methods of the invention. An ultrasound probe 1 , transmits an ultrasound wave into the cranial cavity. The ultrasound probe is placed on the head of a patient, and is then used to generate an ultrasound pulse which propagates through the skull and brain of the patient. The ultrasound pulse is reflected off of the occipital portion of the cranium 9 as well as off of other semi-rigid or rigid structures encountered during transit across the brain tissue 8 . One such structure that is encountered by the ultrasound pulse during transit is the third ventricle, including the anterior and posterior walls of the ventricle. The ultrasound pulse is reflected back to the ultrasound probe 1 to the ultrasound acquisition system 7 . Any commercially available ultrasound apparatus may be used with the methods and systems of the present invention (see, Advanced Transducer Services, Inc. [online], [retrieved on Jul. 30, 2008]. Retrieved from the Internet <URL: www.atsultrasound.com/>). The signal can be interpreted by the microprocessor system with a loaded algorithm 6 , which identifies the position of the third ventricular wall and correlates EPG points to an ICP value.
FIG. 1 represents one embodiment of the system that can be used to measure the ICP. The system includes any central processing unit (“CPU”) or microprocessor system, such as a laptop computer 6 , a universal serial bus (“USB”) interface 5 , a digital signal processor (“DSP”) 4 , an amplifier, an analog to digital converter (“ADC”) 3 , an ultrasound circuit 2 and an ultrasound probe 1 , having a transmitter, a receiver and a probe for generating the ultrasound pulse. The system is integrated with a means for measuring heart beats. It will be appreciated that the embodiment shown in FIG. 1 represents only one sample configuration of the system of the invention having a CPU 6 , an analog to digital converter 3 and an ultrasound probe 1 . All of these components are commercially available from standard electronic suppliers.
Standard, commercially available components may be used in system of the present invention. The following description of specific components is only exemplary, and the system of the present invention is not limited to these components. For example, the DSP 4 may be a C2000 DSC and TMS320C20x by Texas Instruments, a Canberra's 2060 model, CEVA-X1641, CEVA-X1622, CEVA-X1620, or the CEVA-TeakLite-III. The DSP 4 is responsible for generation of electrical pulses or signals with a frequency of at least 1 MHz via the probe 1 , detection of the reflected waves or echoes through the probe 1 , and processing of the detected digital signals. The ranges can be changed in the firmware of the DSP 4 according to the signal studied.
A measurement cycle is initiated when a start signal from the computer 6 is received by the DSP 4 . In response, the DSP 4 instructs the probe 1 to generate a series of ultrasound pulses. A commercially available ultrasound probe may be used with the methods and systems of the invention (see, Advanced Transducer Services, Inc. [online], [retrieved on Jul. 30, 2008]. Retrieved from the Internet <URL: www.atsultrasound.com/>). The ultrasound probe 1 should be capable of transmitting ultrasound waves at a frequency of at least about 1 MHz, and up to about 10 MHz.
Ultrasound sources and detectors may be employed in a transmission mode, or in a variety of reflection or scatter modes, including modes that examine the transference of pressure waves into shear waves, and vice versa. Ultrasound detection techniques may also be used to monitor the acoustic emission (“s”) from insonified tissue. Detection techniques involve measurement of changes in acoustic scatter such as backscatter, or changes in acoustic emission. Examples of acoustic scatter or emission data that are related to tissue properties include changes in the amplitude of acoustic signals, changes in phase of acoustic signals, changes in frequency of acoustic signals, changes in length of scattered or emitted signals relative to the interrogation signal, changes in the primary and/or other maxima and/or minima amplitudes of an acoustic signal within a cardiac and/or respiratory cycle; the ratio of the maximum and/or minimum amplitude to that of the mean or variance or distribution of subsequent oscillations within a cardiac cycle, changes in temporal or spatial variance of scattered or emitted signals at different times in the same location and/or at the same time in different locations, all possible rates of change of endogenous brain tissue displacement or relaxation, such as the velocity or acceleration of displacement, and the like. Multiple acoustic interrogation signals may be employed, at the same or different frequencies, pulse lengths, pulse repetition frequencies, intensities, and the multiple interrogation signals may be sent from the same location or multiple locations simultaneously and/or sequentially. Scatter or emission from single or multiple interrogation signals may be detected at single or at multiple frequencies, at single or multiple times, and at single or multiple locations.
FIG. 3 shows a single ultrasound reflected signal (“USRS”). Graphically, this ultrasound signal is referred to as an echopulsograph or EPG 10 . It is an interactive signal that indicates the anatomic position of the anterior and posterior cranial vaults and the intracranial contents in the path of the ultrasound pulse. The ultrasound signals that insonate the brain, including the third ventricle, possess a certain frequency characteristic. If the return signal is unchanged, the EPG is merely measuring anatomic structures and reflecting back the same wave form. However, if the insonated ultrasound signal interacts with everything in its path, particularly the third ventricle dynamics, the resulting waveform or EPG is interactive and can be filtered to obtain a set of reflected signals to calculate ICP. For example, FIG. 4 is a labeled interactive EPG. The recognizable portions of the waveform correspond to reflected signals (“a”) inside the probe 11 , (“b”) of the anterior cranial vault, dura and meninges 12 , (“c”) of the brain 13 , (“d”) of the third ventricle 14 , and (“e”) the reflected signal of dura and the posterior cranial vault 15 .
During any cardiac cycle (“systole and diastole”) multiple EPG measurements can be taken; FIG. 7 is a side-by-side comparison of EPGs and a QRS complex showing the relationship between the cardiac cycle and the brain. Walls of the third ventricle expand and contract during the cardiac cycle (“systole and diastole”). Therefore, the positions of the walls of the third ventricle vary relative to the ultrasound probe during the cardiac cycle.
In one embodiment of the invention, at least 10 EPGs measurements are made. In another embodiment, at least 25 EPGs are made. In a third embodiment, at least 50 EPGs are made. In a fourth embodiment, at least 100 EPGs are made. The EPG signals are each digitized and displayed on a display screen as a function of intensity and time. As shown in FIG. 5 , points from the third ventricle region of all the EPGs 16 - 19 created are inputted into an algorithm to calculate an ICP value. These points are represented more clearly in FIG. 6 , which depicts how the third ventricle region of an EPG is divided into insular points 21 - 35 over time (“t”).
These points represent the discrete bundles of digitized data points from the isolated portion of the EPG, which are then used to calculate ICP based on the equation:
ICP=Σ tan h (“Σ I×W+b ”) W+b
where I represents the input matrix of all the data points from the selected portion of the echopulsogram 21 - 35 , W is the weight matrix that is obtained through the training process, and b is a random bias constant assigned by the computer 6 .
The input matrix is a (“n by k”) mathematical matrix where n rows equals the number of samples; in one embodiment of this invention, this value is at least ten. The k columns equal the data points along the respective EPGs found between the ventricle walls. The matrix is calculated via known mathematical means.
The W value, or weight matrix, is obtained through the training or correlation process, which must be done once. The method of training the SANN is described in V. D. De Viterbo and J. C. Belchior, Artificial Neural Networks Applied for Studying Metallic Complexes, Journal of Computational Chemistry, vol. 22, no. 14, 1691-1701 (“2001”). The training process is a backpropagation algorithm that consists of repeatedly presenting the input and desired output sets to the network. The weights are gradually corrected until the desired error is achieved in the network. This method is depicted in FIG. 8 . In one embodiment of the invention, the backpropagation method is carried out according to
Δ W l ji =ηδ j l out i l−1 +μΔW ji l(previous) (1)
where ΔW l ji represents the correction to the weight between the jth element in the lth layer and ith element in the previous layer. The quantity out I l−1 contains the output result on the l−1 layer. The parameters η and μ are denominated the learning rate and the momentum constant, respectively. These constants determine the rate of convergence during the training procedure. Usually, these parameters are dynamically adjusted to obtain the best convergence rate. The errors introduced during the training stage are calculated as
δ i last =( y j −out j last )out j last (1−out j last ) (2)
and
δ j l =(Σ k=1 r δkl+ 1 Wkjl+ 1) out j l (1−out j l ) (3)
where y j is the output target that is compared with the output results of the out j l of the lth layer. The network error can be then calculated as
ε l =Σ j=1 n ( y j −out j l ) 2 (4)
For the learning procedure the neuron behavior was calculated through the sigmoid function for the intermediary layer and a linear function in the output layer.
For minimizing functions, one embodiment of the invention uses the robust method proposed by Levenberg and implemented by Marquardt (Marquardt et al. J Soc Ind Appl Math 11:431 (“1963”). It works through the dynamical adjustment of the Steepest Descent method and Newton's method. Its advantage is that it is much faster in the way of finding the minimum. According to the Levenberg-Marquardt method (LMM), the update matrix of the weights can be calculated as
W n+1 =W n −( H+BI ) −1 ∇ε 1 ( W n ) (5)
where H is the Hessian matrix and β is a variable parameter, and usually it starts as β=0.01. The latter is changed during the minimization search according to the estimation of the local error, and I is the identity matrix. The most difficult task when the LMM is used can be attributed to the calculation of H, and it is approached by
H=J T J (6)
where J is the Jacobian matrix and is given by
J = ∂ ɛ l ∂ out j 1 ( 7 )
where l is the relative error of all weights [eq. (4)]. This approximation for solving the Hessian matrix will avoid computation of second derivatives, which simplifies the calculations. Substituting the above approaches into eq. (5), one obtains
W n+1 =W n −[J T ( W n ) J ( W n )+β n I] −1 J T ( W n )ε 1 ( W n ) (8)
Equation (8) will approach to the pure Gauss-Newton method if β→0 or to the Steepest descent method when β→∞.
In accordance with the present invention, this means that, initially, an ICP value is calculated via the equation with a randomly assigned W value. The resulting ICP value is the test value. A reference ICP value is determined by a known invasive means of measuring ICP. Training then involves comparing that test ICP value to the reference ICP value obtained from a known invasive method. If the difference in ICP values is greater than an acceptable error, the random W value is adjusted. Upon adjusting the W value, a new test ICP value is calculated using the equation and this value is again compared to the reference ICP value. This training process of adjusting the weight value, calculating a new ICP value and comparing it to a reference point is repeated until the calculated ICP value from this process is within an acceptable range of error to the reference value. When this occurs, the W value is stored by the computer 6 and automatically correlated to that specific ICP value that was obtained as the test ICP value. In one embodiment of the invention, the algorithm to train the neural network is as follows:
BEGIN
WHILE START=ON
GET SAMPLES OF DIGITALIZED ECHO FROM ADC
STORE THE SAMPLES IN A FILE
PLOT THE SAMPLES
CHOOSE THE VALID WAVES (MANUAL PROCESS)
IF WAVES ARE VALID
START=OFF (MANUAL)
END IF
END WHILE
NUMBERS OF INPUT OF THE NEURAL NETWORK=306
NUMBERS OF HIDDEN NEURONS=2
W1(2×306)=RANDOM NUMBERS
W2(1×2)=RANDOM NUMBERS
WHILE(ERROR>0.001)
ICP_NON_INVASIVE=
W2*(TANH(W1*DIGITALIZED_ECHO))
ERROR=ICP_INVASIVE − ICP_NON_INVASIVE
CALCULATE THE NEW W1 AND W2 USING THE
LEVENBERG MARQUARDT METHOD
W1=W1+DW1
W2=W2+DW2
END WHILE
END BEGIN
This training process must be completed for each possible ICP value for the computer to create an index or database of weight values and corresponding ICP values. After the training, the computer 6 is able to calculate the ICP values automatically by corresponding the appropriate W value for each set of inputs and ICP value without an invasive procedure. FIG. 9 illustrates how the training process expands the range of possible measured ICP values. Obtaining the ICP values of 9 patients, 3 groups of 3, with 3 different ICP values and inputting their would be ultrasound data into the invention as an initial matter provides the invention with a baseline for comparison. The operating range of the invention would also be equal to the range of the known ICP values it was trained on.
The neural network is, therefore, an Algorithm for Correlation of Dynamic Properties of the Head (“ACDPH”) 20 . It creates ICP waves using the inputted data. Each point at time (“t”) along the EPG wave is then plotted across multiple EPG waves. As can be appreciated, up to (“n”) samples can be made from a single EPG wave. A graph is then prepared for each time (“t”) showing the amplitude of the EPG wave at each time (“t”) for multiple EPG waves. For structures, such as the occipital portion of the cranium, which do not vary over the cardiac cycle, the graph showing the sampling from multiple EPG waves at time (“t”) is a straight line. The same is not true of points along the third ventricle. Graphically, this is reflected by a change in amplitude in the EPG wave during the cycle. More specifically, this change is represented as an ICP wave with a sine wave pattern, reflecting the expansion and contraction of the wall over the cardiac cycle. The ADCPH 20 obtains the upper and lower boundaries of the inputted points and correlates that data with the value of patients' ICPs obtained from an invasive device through training. After training, the ADCPH is able to calculate the ICP of the patient automatically without using an invasive method. In one embodiment of the invention, the algorithm to obtain the ICP values is as follows:
BEGIN
WHILE START=ON
LOAD TRAINED NEURAL NETWORK W1 AND W2
GET SAMPLES OF DIGITALIZED ECHO FROM ADC
STORE THE SAMPLES IN A FILE
PLOT THE SAMPLES
CHOOSE THE VALID WAVES (MANUAL PROCESS)
IF WAVES ARE VALID (MANUAL PROCESS)
ICP_NON_INVASIVE=
W2*(TANH(W1*DIGITIZED_ECHO))
END IF
END WHILE
END BEGIN
FIG. 10 depicts one embodiment of the hardware for the instant training process. The data from the invasive ICP monitoring hardware, the data from the non-invasive ICP monitoring hardware, and the electrocardiogram (EKG) data are inputted into the DSP, which is then connected to a laptop computer through a USB interface. For data output, in one embodiment of the invention, a laptop computer displays on its monitor the EPG, the EKG, and the calculated non-invasive ICP values.
In contrast to the '743 patent, the present invention provides a more accurate ICP measurement because it takes into account the changes over time in the third ventricle. The '743 patent relies on a point in time at which the flow of blood through the brain tissue is primarily exiting the brain. Moreover, after generating an EPG from an Echo EG signal and an ECG, the prior art patent relies on the operator to select the portion of the EPG that corresponds to the ICP value. In the present invention, the computer program identifies the relevant portion of the graph, the third ventricle. Last, the '743 patent calculates ICP based on an equation, ICP=ρ(“t/T”)*[t/T]−β, that relies on four different equations to define p(“t/T”).
The scope of the present invention is not limited by what has been specifically shown and described hereinabove. Numerous references, including patents and various publications, are cited and discussed in the description of this invention. The citation and discussion of such references is provided merely to clarify the description of the present invention and is not an admission that any reference is prior art to the invention described herein. All references cited and discussed in this specification are incorporated herein by reference in their entirety. Variations, modifications and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and scope of the invention. While certain embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims.
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A novel method to noninvasively measure intracranial pressure (ICP) and more generally brain elasticity is disclosed. ICP is determined using an algorithm coupled on a simulated artificial neural network (SANN) that calculates ICP based on a determination of a set of interacted ultrasound signals (IUSs) generated from multiple ultrasound pulses. The methods and systems of the present invention are capable of rapidly determining ICP without manual review of EPG waves by a technician.
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BACKGROUND OF THE INVENTION
This invention deals generally with heat transfer and more particularly with a capillary loop evaporator that has full thermal contact of the wick with the heat input surface.
A capillary loop and a loop heat pipe are devices for transferring heat by the use of evaporation at the source of heat and condensation at the cooling location, and they eliminate some of the limitations of a simple heat pipe by separating the vapor and liquid movement into different conduits. Thus, liquid fed to an evaporator is evaporated and moves through a vapor transport line to the condenser, and condensate moves from the condenser to the evaporator through a liquid transport line. Typically, a liquid reservoir is constructed in close vicinity to the evaporator and a barrier wick separates the liquid in the reservoir from the vapor in the evaporator while moving liquid into the evaporator wick by capillary action.
Prior art capillary loop and loop heat pipe evaporators typically have vapor channels at the contact boundary between the evaporator wick and the heat input surface, which is the wall of the evaporator enclosure. The vapor channels are formed as grooves in the wick or the evaporator enclosure inner wall at the boundary, and the lands between the grooves are the only direct thermal path from the heat input surface to the liquid within the wick. From the wick the liquid is evaporated and fed into the vapor channels. The vapor channels then open into a vapor space that is available to the vapor transport line. Some such devices, such as that disclosed in U.S. Pat. No. 6,058,711 to Maciaszek et al, even have the vapor generating wick completely surrounded by the thermally insulating vapor space.
Basic limitations of the typical capillary loop evaporator are the limited direct contact between the wick and the heated surface, and the tendency of the vapor generated at the heat transfer surface to interfere with heat transfer into and through the wick. Another disadvantage of the conventional loop heat pipe evaporator is its proximity and thermal transfer to the reservoir. This phenomenon is referred to as parasitic heat loss or heat leakage, and it causes some heat to be transferred from the evaporator to the reservoir by means of heat conduction across the wick and two phase heat transfer in the central volume which the wick surrounds. Such heat is therefore not moved to the condenser for disposal. Still other problems arise in the difficulty of manufacturing capillary loop and loop heat pipe evaporators since they usually require cylindrical wicks with longitudinal grooves on the outer surface.
It would be very beneficial to have available a capillary loop evaporator that has improved heat transfer from the heat source to the evaporator wick, reduced parasitic heat leakage to the reservoir, and reduced manufacturing complexity.
SUMMARY OF THE INVENTION
The present invention is a capillary loop evaporator wick that has full contact at its outer boundary with the walls of the heated enclosure within which it is installed. In its simplest form the evaporator has a cup with sidewalls of wick material installed tightly against the inside walls of an enclosure of heat conductive material, and in most embodiments the cup has an integral end wall at one end extending across the entire enclosure and resembling a cup bottom. The end wall acts as a barrier between the vapor space in the center of the cup and the liquid reservoir on the other side of the end wall of the cup, and the barrier can be made of impervious material or porous capillary material.
The capillary pumping action of the barrier of wick material and the wick sidewalls of the cup deliver the liquid all along the boundary of the wick and the heated enclosure wall at which location it is vaporized. After the vapor is formed it moves across the wick sidewalls into the vapor space without significant interference from other vapor, and is replaced by other liquid within the wick. The open end of the wick cup is located near an end cap of the enclosure to which is attached the vapor line connecting the evaporator to the condenser.
Several structural variations can be added to enhance the performance of the simple cup of wick material. One such modification is selection of the sidewall wick thickness and pore size to accommodate different liquids within the capillary loop and different heat loads.
Another structure that can be used advantageously when the heat input is located in a specific area of the enclosure is wick sidewalls of varying thickness. In such a structure the sidewall adjacent to the heated area of the enclosure is formed with a thinner cross section to more easily permit the vapor to escape from the wick and thus maintain a lower evaporative temperature drop. Thicker sidewall sections are used adjacent to the enclosure wall where heat is not directly applied, so that the larger cross section is available for liquid transport, reducing the liquid pressure drop. Using a larger pore size wick in the thicker sidewalls can further enhance the characteristics of such a wick. The evaporative surface and the barrier wall are then made with finer pore sizes, and the finer evaporative pores draw liquid from the coarser wick, while the finer barrier wall wick allows operation against high gravitational or accelerational heads.
Another structure that reduces the liquid pressure drop is a web structure built into the interior of the cup. Such a structure extends longitudinally from the barrier wall toward the open end of the cup and across the interior between two or more sides. Such a web decreases the liquid pressure drop by increasing the wick cross section, delivers liquid to large portions of the heated wick, and permits heat input around the entire enclosure. The web's position in the interior of the cup and away from the heat input improves its liquid transport capability because very little of its volume is occupied by vapor. The web can also be constructed with a tunnel artery to further facilitate liquid distribution.
The ridge wick is a variation of the web structure that also provides increased wick cross section and allows more liquid flow into the wick sidewalls. Such a structure is essentially a partial web in that it extends longitudinally along the sidewall from the barrier wall, but it does not extend completely across the interior to another sidewall. Nevertheless, it furnishes liquid to much of the heated sidewall and is relatively vapor free.
The tunnel artery wick is an enhancement that immensely increases the liquid transport capability of ridge wicks and web structures. In such a configuration the ridges or webs of wick material include longitudinally extending tunnel arteries located inward, toward the center of the enclosure and away from the heated sidewall. The arteries are therefore somewhat isolated from the heat and the generated vapor. Such arteries extend through the barrier wick and directly into the reservoir of the capillary loop. Thus, liquid enters the arteries and moves directly into proximity with most of the length of the evaporator's wick. In effect the tunnel artery wick places parts of the liquid supplying reservoir adjacent to the very part of the evaporator wick that uses the liquid.
However, tunnel arteries have the risk of boiling and blockage of liquid flow by vapor if a heat source is too close to a tunnel. The present invention therefore includes several design enhancements to counteract this problem, the simplest of which is to simply modify the ridge into a higher ridge protruding farther inward toward the center of the evaporator. Locating the arteries in the part of the ridge nearest to the center of the evaporator reduces the heat flow into the artery and reduces the risk of boiling and vapor blockage.
Another approach to preventing boiling in the arteries is the use of isolating wicks of finer pore structure or lower thermal conductivity between the heat source and the artery. Such isolating wicks can be located at the artery as an artery wall structure, at the junction between the artery support ridge and the evaporative wick on the sidewalls of the enclosure, or anywhere between those locations. Such construction encourages vapor flow around rather than through the isolating wick and thus avoids accumulation of vapor in the arteries.
The arteries can also be constructed to include cable arteries. A cable artery is essentially a structure that has a multiple strand cable running through its length. The cable then pumps liquid along its length by capillary action between its strands, and has the advantage of allowing vapor to vent back into the reservoir in the annular space around the cable without blocking the liquid flow within the cable. Other high permeability arteries similar to cable arteries can also be constructed from mesh screen and metal felt. The added benefit of operation in a zero gravity environment can be attained by installing a reservoir wick on the interior walls of the reservoir and extending the high permeability arteries into contact with the reservoir wick. The reservoir wick then collects liquid in the reservoir and moves it into the evaporator through the high permeability arteries. This action can be enhanced even further by installing an additional wick structure in the reservoir, such as a web interconnecting opposite sidewalls, thereby capturing more liquid that is directed into the evaporator arteries.
Another way to feed liquid to the evaporator wick is the use of tubing extending from the reservoir into tunnels within the evaporator wick. The tubing extends well into each of the tunnels, and all the lengths of tubing are connected to a common liquid manifold within the reservoir. The liquid manifold is fed by the liquid return line from the condenser, and any vapor in the tunnel can escape back into the reservoir through the annular gap between the tubing and the tunnel wall. A reservoir wick then captures and returns liquid condensed from the escaped vapor back into the evaporator wick.
Cable and other high permeability arteries and tubing fed tunnels lend themselves to a structure that significantly simplifies the construction of an evaporator for a capillary loop. As previously described, the conventional evaporator has both an evaporator wick on the sidewalls of the enclosure and a barrier wick across the enclosure at one end of the evaporator wick. Not only is the junction of these two wicks a difficult construction problem, but any crack that occurs in the barrier wick will prevent the system from operating. Furthermore, the barrier wick must withstand the difference in pressure between the evaporator and the reservoir.
However, the use of either cable arteries or tubing fed tunnels permits the complete elimination of the barrier wick because liquid is fed to the evaporator wick by the cables or the tubing, and it also permits the separation of the evaporator and reservoir enclosures. When the evaporator and reservoir enclosures are separated, all that is needed is that the two enclosures have interconnecting pipes or tubing sealed to both enclosures through which excess vapor and the tunnel arteries, cable arteries, or artery feed tubes can pass.
The present invention thereby provides a capillary loop evaporator that has improved heat transfer from the heat source to the evaporator wick, reduced likelihood of vapor blockage of the liquid supply, and particularly with the separated evaporator and reservoir, reduced parasitic heat loss to the reservoir.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the typical capillary loop showing the location of the evaporator wick of the preferred embodiment.
FIG. 2 is a perspective cut away view showing the interior of the basic evaporator of the preferred embodiment of the invention
FIG. 3 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention with an evaporator wick of greater thickness and a strength enhancing barrier plate.
FIG. 4 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention with an evaporator wick with sidewalls of varying thicknesses.
FIG. 5 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention with an evaporator wick which includes a web wick structure across the interior of the evaporator.
FIG. 6 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention with an evaporator wick which includes a longitudinal ridge with a tunnel artery.
FIG. 7 is a cross section view across a cylindrical evaporator wick showing an alternate embodiment of the invention in which the evaporator wick includes high longitudinal ridges with tunnel arteries.
FIG. 8 is a cross section view across a cylindrical evaporator wick showing an alternate embodiment of the invention in which the evaporator wick includes high longitudinal ridges with tunnel arteries including artery walls with isolating wicks with pore structures that prevents vapor flow into the arteries.
FIG. 9 is a cross section view across a cylindrical evaporator wick showing an alternate embodiment of the invention in which the evaporator wick includes high longitudinal ridges with tunnel arteries and isolating wick structures within the ridges that have pore structures that prevent vapor flow into the arteries.
FIG. 10 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention which has an evaporator wick that includes longitudinal ridges with tunnels and cable arteries within the tunnels.
FIG. 11 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention with an evaporator wick which includes longitudinal ridges with tunnels and tubing that feeds liquid from a manifold in the reservoir into the tunnels.
FIG. 12 is a perspective cut away view showing the interior of an alternate embodiment of the evaporator of the invention with a detached and separated reservoir rather than an integrated reservoir.
FIG. 13 is a perspective cut away view showing the interior of an alternate embodiment of the evaporator of the invention with a barrier formed within an easily sintered combined evaporator wick and reservoir wick.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic diagram of typical capillary loop 10 showing evaporator wick 12 of the preferred embodiment of the invention within evaporator 14 . Evaporator wick 12 of FIG. 1 is a simple cup and is also shown in FIG. 2 in a perspective cut away view to better show the interior of evaporator 14 . The important characteristic of evaporator wick 12 is that all the outer surfaces of its sidewalls are in intimate contact with heated walls 16 of the enclosure forming evaporator 14 . This complete contact between evaporator wick 12 and heated enclosure walls 16 makes heat transfer and vaporization of the liquid within evaporator wick 12 much more effective, and the vapor generated moves through evaporator wick 12 into vapor space 13 .
When capillary loop 10 is in operation, heat enters evaporator 14 and travels through evaporator enclosure wall 16 into wick 12 which is saturated with liquid. The heat causes the liquid to vaporize, and the vapor pressure moves the vapor out of evaporator wick 12 , into vapor space 13 , to vapor line 18 , and then into condenser 20 . Since condenser 20 is cooled by fins 21 , the vapor within it condenses, and, driven by the vapor pressure generated in evaporator 14 , the condensate liquid moves into liquid line 22 and back to reservoir 24 within evaporator 14 . Barrier wick 26 , which is attached to evaporator wick 12 , separates the liquid in reservoir 24 from vapor space 13 and moves the liquid by capillary action from reservoir 24 into evaporator wick 12 , from where the continuous cycle is repeated.
Capillary loop 10 is shown in an orientation that is ideal for gravity aided operation, in which the condensate flows down liquid line 22 under the influence of gravity. However, loop 10 will also operate against gravity if it contains sufficient liquid, including liquid in vapor line 18 , to assure that evaporator wick 12 is wetted when heat is not being applied. In such a circumstance, when heat is applied the generated vapor will displace any liquid from vapor line 18 and the necessary part of condenser 20 , and when the loop is operating, the displaced liquid will be located in the internal volume of reservoir 24 .
FIGS. 3 through 6 are perspective cut away views of alternate embodiments of the invention showing the interior of evaporator 14 with evaporators of different construction. In each embodiment evaporator 14 is the same except for the specific structure of the evaporator wick.
FIG. 3 shows evaporator 14 with the sidewalls of evaporator wick 30 having greater thicknesses than evaporator wick 12 of FIG. 2 . This increase in thickness of evaporator wick 30 , and in fact any increase in thickness of the sidewalls of an evaporator wick, adds cross section area to the liquid flow path and thereby reduces the liquid pressure drop within the wick. This enhances the ability of the wick to furnish liquid for evaporation to its regions that are most remote from barrier wick 26 , which is the initial source of the liquid in the wick. Wick thickness, and the pore size within the wick, can also be used to better accommodate an evaporator to different liquids and different heat loads. FIG. 3 also shows strengthening plate 27 which is a solid plate bonded to or formed within barrier wick 26 . Strengthening plate 27 not only prevents cracks in barrier wick 26 but assures that a crack that occurs in barrier wick 26 will not prevent the system from operating, and plate 27 helps barrier wick 26 withstand the difference in pressure between the evaporator and the reservoir. Holes 29 in plate 27 provide access to barrier wick 26 so that liquid in reservoir 24 can enter barrier wick 26 .
FIG. 4 is a perspective cut away view showing the interior of an alternate embodiment of an evaporator of the invention with evaporator wick 32 having varying thicknesses. Thus, portion 34 of wick 32 has a greater thickness than portion 36 . Such a configuration is advantageous when the heat input into evaporator 14 is restricted to a specific area of the evaporator. In such an application thinner portion 36 is located adjacent to the heat input of evaporator 14 so that vapor formed in portion 36 has a shorter travel path to vapor space 13 , and vapor can more easily escape and thereby maintain a lower evaporative temperature drop. Thicker sidewall portion 34 , located where there is little or no heat input, furnishes a larger cross section, thus reducing the liquid pressure drop and furnishing more liquid to heated thinner portion 36 .
It should be appreciated that the very gradual transition from thinner to thicker wick portions on opposite sides of the evaporator as shown in FIG. 4 is not a requirement for the benefit to be derived, and it is also possible to have a relatively steep transition to a thicker portion of wick that occupies much more of the sidewalls of the evaporator. Furthermore, larger pore sizes within the thicker portion of the wick can also improve the action of the wick.
FIG. 5 is a perspective cut away view showing the interior of another alternate embodiment of an evaporator of the invention with evaporator wick 38 constructed to include wick web structure 40 across the interior of the evaporator. The benefit of web structure 40 is similar to that of a section of thicker wick sidewall in that it provides an increased cross section and multiple paths for feeding liquid to the heated portions of the wick. Web structure 40 extends longitudinally from barrier wick 26 toward the open end of the cup structure of evaporator wick 38 and across the interior between sidewalls of the cup. Although FIG. 5 suggests only a single web structure across the evaporator, a true web with multiple extensions across vapor space 13 is also possible. FIG. 5 also shows tunnel artery 41 located within web 40 . Tunnel arteries are discussed in greater detail in the following text, but it is important to appreciate that tunnel artery 41 passes through barrier wick 26 and opens into reservoir 24 , but is dosed off at the end of web 40 seen in FIG. 5 . It is also important to appreciate that such a tunnel artery can also include within it cable arteries as shown in FIG. 10 , other high permeability arteries, and feed tubes as shown in FIG. 11 .
FIG. 6 is a perspective cut away view showing the interior of another alternate embodiment of an evaporator of the invention in which evaporator wick 42 includes limited width longitudinal ridge 44 within which is tunnel artery 46 . Ridge 44 itself, even without a tunnel artery, provides the benefit of increased wick cross section to facilitate liquid transport to the sidewalls of the wick. The fact that ridge 44 protrudes radially inward toward the center of vapor space 13 makes it less likely to contain vapor that would block liquid flow. Tunnel artery 46 further enhances the ability of ridge 44 to transport liquid to heated portions of wick 42 , and this technique operates for an evaporator in which the entire evaporator is heated when multiple ridges 44 including arteries 46 are included around the evaporator. Tunnel artery 46 is located in the part of ridge 44 that is most remote from heated wall 16 to minimize vapor interference with the liquid flow, and tunnel artery 46 extends longitudinally over a large portion of evaporator wick 42 and opens directly into reservoir 24 . The effect of this structure is essentially to extend reservoir 24 and its liquid supply into close contact with the heated portions of evaporator wick 42 .
FIGS. 7-9 are cross section views across a cylindrical evaporator wick 48 showing alternate embodiments of the invention in which the evaporator wick 48 includes high longitudinal ridges 50 with tunnel arteries 52 protruding into vapor space 13 . These alternate embodiments reduce the risk of boiling within the arteries that is sometimes caused when a heat source is too close to the artery. Such boiling causes vapor blockage of the liquid flow in the artery.
FIG. 7 shows the basic structure of high ridges 50 within evaporator wick 48 . Arteries 52 are located in the parts of the ridges that are as remote as possible from the heat source located at the outer circumference of evaporator wick 48 , as shown in FIG. 1 .
FIG. 8 shows an enhanced structure for high ridges 50 of evaporator wick 48 . Tunnel arteries 52 of FIG. 8 are shown with walls that are constructed with isolating wicks 54 . Isolating wicks 54 have finer pore structures than the rest of the ridges. Isolating wicks 54 prevent vapor flow into the arteries because the vapor travels the path of least resistance and moves out of the ridges and into vapor space 13 rather than moving through the more restrictive fine pore structure of isolating wicks 54 .
FIG. 9 shows another location for isolating wick structures 56 within high ridges 50 of evaporator wick 48 . Isolating wick structures 56 are located within high ridges 50 and have the same fine pore structure as isolating wicks 54 of FIG. 8 that prevents vapor flow into the arteries. The essential difference of isolating wicks 56 is that they are located within ridges 50 rather than around the arteries as are isolating wicks 54 of FIG. 8 . Nevertheless, the action of isolating wicks 56 is the same as those of isolating wicks 54 because isolating wicks 56 span across the entire cross sections of high ridges 50 and therefore divert vapor into vapor space 13 to prevent the vapor from entering arteries 52 . It should be appreciated that isolating wicks can be located anywhere along the height of high ridges 50 .
FIG. 10 is a perspective cut away view showing the interior of an alternate embodiment of the invention that is an evaporator 58 with evaporator wick 60 and barrier wick 61 . Evaporator wick 60 includes longitudinal ridges 62 with tunnels 64 and cable arteries 66 within tunnels 64 . However, other high permeability arteries similar to cable arteries, such as those constructed from mesh screen and metal felt can also be used within tunnels 64 . Cable arteries 66 are essentially multiple strand cables running through the length of tunnels 64 . Cables 66 then pump liquid along their lengths by capillary action between the strands, and have the advantage of allowing vapor to vent back into reservoir 68 by means of the open volumes around cables 66 without blocking the liquid flow within the cables. The added benefit of operation in a zero gravity environment can be attained by installing reservoir wick 70 on the interior walls of reservoir 68 and extending cable arteries 66 into contact with reservoir wick 70 . Reservoir wick 70 then collects liquid in reservoir 68 and moves it into evaporator 60 through cable arteries 66 . This action can be enhanced even further by installing an additional wick structure in the reservoir, such as a web across reservoir 68 interconnecting opposite sidewalls, thereby capturing more liquid that can be directed into cable arteries 66 .
FIG. 11 is a perspective cut away view showing the interior of another alternate embodiment of the invention with evaporator 72 that has evaporator wick 60 and barrier wick 61 . Evaporator wick 60 includes longitudinal ridges 62 with tunnels 64 . To this extent the evaporator wick structure is the same as shown in FIG. 10 . However, instead of cable arteries within tunnels 64 , evaporator 72 has tubing 74 that feeds liquid into tunnels 64 . Tubing 74 extends well into each of the tunnels, and all the multiple lengths of tubing are connected to common liquid manifold 76 within reservoir 78 . Manifold 76 receives liquid directly from liquid return line 22 (see FIG. 1 ), and any vapor in tunnels 64 can escape back into reservoir 78 through the annular gap between tubing 74 and the walls of tunnels 64 . As in FIG. 10 , reservoir wick 70 then captures and returns liquid condensed from the escaped vapor back to the evaporator wick 60 . An additional wick can also be added to partially occupy the annular space between tubing 74 and tunnel walls and be in contact with reservoir wick 70 to return the reservoir condensed liquid to evaporator wick 60 .
FIG. 12 is a perspective cut away view showing the interior of evaporator 80 that is very similar to evaporator 72 of FIG. 11 except that it does not have a barrier wick or an integrated reservoir as in evaporator 72 of FIG. 11 . Instead of an integrated reservoir and a barrier wick at the end of evaporator wick 81 , evaporator 80 has sealed end plate 82 , and evaporator 80 is connected to detached and separated reservoir 84 by lengths of connecting tubing 86 .
The use of connecting tubing 86 to feed tunnels 64 permits the complete elimination of barrier wick 26 ( FIGS. 1-6 ) because liquid is fed to the evaporator wick through connecting tubing 86 . This structure permits the physical separation of the enclosures of evaporator 80 and reservoir 84 . When the evaporator and reservoir enclosures are separated, all that is needed is that the two enclosures have connecting tubing 86 sealed to both enclosures so that tunnels 64 are fed directly from connecting tubing 86 , and connecting tubing 86 acts as extensions of tunnels 64 . A further advantage of the structure shown in FIG. 12 is that connecting tubing 86 can also enclose high permeability arteries, cable arteries 66 as shown in FIG. 10 , or feed tubing 74 as shown in FIG. 11 , and with such a structure it is quite simple to make the connection between evaporator 80 and reservoir 84 flexible. As indicated by the break lines shown in FIG. 12 , connecting tubing 86 can span different distances which will essentially be determined by the liquid flow and vapor pressure characteristics of entire capillary loop 10 of FIG. 1 and the capillary capability of the artery.
FIG. 13 is a perspective cut away view showing the interior of an alternate embodiment of the invention with evaporator 90 and reservoir 91 . This embodiment includes barrier 92 formed between easily sintered continuous evaporator wick 94 and reservoir wick 96 . Evaporator wick 94 and reservoir wick 96 are formed as a continuous structure that includes ridges 98 , which also run continuously between evaporator wick 94 and reservoir wick 96 . Barrier 92 , including through passages 93 for wick material, is formed to mate with continuous evaporator wick 94 , reservoir wick 96 , and ridges 98 , so that the only paths available between evaporator wick 94 and reservoir wick 96 for liquid and vapor are within the wick material itself. Such a structure can be formed by sintering in one operation, but barrier 92 can be either capillary material or a previously constructed solid structure sintered in place. The sintering process permits many variations in the structures of barrier 92 and ridges 98 so that the shape of through passages 93 can include, among others, the rectangular slots shown or circular holes. Ridges 98 can also have various shapes and can include tunnel arteries as shown in FIG. 6 , cable arteries as shown in FIG. 10 , or feed tubes as shown in FIG. 11 . In some cases ridges 98 may not be needed with evaporator wick 96 and reservoir wick 96 having smooth inner surfaces. Furthermore, the shape of barrier 92 can be constructed to mate with any enclosure configuration.
The present invention thereby provides a capillary loop evaporator that has improved heat transfer from the heat source to the evaporator wick, reduced likelihood of vapor blockage of the liquid supply, and particularly with the separated evaporator and reservoir, reduced parasitic heat loss to the reservoir.
It is to be understood that the forms of this invention as shown are merely preferred embodiments. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims. For example, the evaporator and the evaporator wick structures need not be circular cylinders, but could be constructed with planar surfaces and also with a smaller space between two opposite sides to yield a slab-like structure.
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The apparatus is a capillary loop evaporator in which the vapor space is the internal volume of a cup shaped evaporator wick with sidewalls in full contact with the outer casing of the evaporator. Liquid is furnished to the wick through thicker wick wall sections, slabs protruding from the liquid-vapor barrier wick, eccentric wick cross sections, or tunnel arteries. The tunnel arteries can also be formed within heat flow reducing ridges protruding into the vapor space. The tunnel arteries can be fed liquid by bayonet tubes or cable arteries, and can be isolated from the heat source with regions of finer wick to impede vapor flow into the liquid. Tunnel arteries also enable separation of the evaporator and the reservoir for thermal isolation and structural flexibility. A wick within the reservoir aids collection of liquid in low gravity applications.
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BACKGROUND OF THE INVENTION
The present invention relates generally to optical scanners and, more particularly, to a modular light source for an optical scanner.
Optical imaging devices which utilize a chromatic beam splitter consisting of composited dichroic beam splitter plates which separate a light beam into parallel color component beams are disclosed in U.S. Pat. No. 4,709,144 of Kent J. Vincent; U.S. Pat. No. 4,806,750 of Kent J. Vincent and Hans D. Neuman; and U.S. patent application Ser. No. 383,463 filed 7/20/89 for OPTICAL SCANNER of David Wayne Boyd, now U.S. Pat. No. 4,926,041, which are all hereby specifically incorporated by reference for all that is disclosed therein.
Optical imaging devices require a light source for illuminating documents or other objects which are to be imaged. It is an object of the present invention to provide a light source for an optical imaging device which has a modular construction for enabling quick and easy replacement of the light source if it fails. It is another object of the present invention to provide a modular light source for an optical imaging device which may be used in association with a slit-type aperture. It is another object of the present invention to provide a modular light source for an optical imaging device which is relatively inexpensive to produce.
SUMMARY OF THE INVENTION
The present invention is directed to an aperture and light source assembly for defining an illuminated scan line which is imaged by an imaging lens assembly of an optical scanner.
The assembly comprises an elongate aperture plate which blocks light other than light from the illuminated scan line from entering the imaging lens assembly. The aperture plate includes a vertically disposed portion having a longitudinally extending, aperture defining slit at a top end thereof.
A light source assembly adapted for illuminating an object which is to be scanned is positioned above the elongate aperture plate. The light source assembly includes a first elongate bulb which is adapted to be positioned adjacent to one lateral side of the vertically disposed portion of the aperture plate and below the top end slit therein. A second elongate bulb is adapted to be positioned adjacent to a the other lateral side of the vertically disposed portion of the aperture plate and below the top end slit therein.
A connector and spacer assembly fixedly connects the first elongate bulb in spaced apart, parallel relationship with the second elongate bulb. An attachment device associated with the connector and spacer assembly enables removable attachment of the light source assembly to the optical scanner.
Thus, the first and second bulbs are installable and removable from said optical scanner as a modular unit.
The invention is also directed to a method of installing an optical scanner light source including the steps of coupling two florescent bulbs together in spaced apart parallel relationship and then mounting the coupled bulbs on an optical scanner with each bulb positioned adjacent to a different lateral side of a scan line defining aperture portion of the scanner.
BRIEF DESCRIPTION OF THE DRAWINGS
An illustrative and presently preferred embodiment of the invention is shown in the accompanying drawings in which:
FIG. 1 is a perspective view of an optical scanner.
FIG. 2 is a perspective view of an optical scanner with an upper panel removed.
FIG. 3 is a perspective view of an optical scanner carriage assembly with a modular light source and light slit assembly removed therefrom.
FIG. 4 is a perspective view of an optical scanner carriage assembly.
FIG. 5 is a perspective view of an optical scanner carriage assembly with a modular light source and light slit assembly removed therefrom, illustrating a fixed light path which extends from a light slit to a focusing lens.
FIG. 6 is a cross-sectional elevation view of an optical scanner carriage assembly illustrating a fixed light path extending from a light slit to a focusing lens.
FIG. 7 is an exploded perspective view of an optical scanner light source assembly.
FIG. 8 is an assembled perspective view of the optical scanner light source assembly of FIG. 7.
FIG. 9 is a perspective view of an optical scanner light slit assembly mounted on an optical scanner carriage.
FIG. 10 is a perspective view of an optical scanner carriage assembly including the light source assembly and light slit assembly of FIGS. 8 and 9.
FIG. 11 is a side elevation view of the optical scanner carriage assembly of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an optical scanner 100 of a type adapted to produce machine readable data representative of a color image of an object which is scanned. The machine readable data produced by the optical scanner 100 is adapted to be received and used by a digital computer in a conventional manner, e.g. the data may be stored on a computer memory device or may be used to produce a color display of the object on a CRT or a color electrostatic print, etc.
The optical scanner 100 comprises a scanner housing 102 having a forward end 101, a rear end 103 and a central longitudinal axis AA, FIGS. 1 and 2. The housing includes a relatively flat upper panel member 104 and a lower housing member 106, FIGS. 1 and 2. The upper panel member 104 comprises a transparent plate 108 which may be approximately laterally centered therein. The transparent plate 108 is positioned relatively nearer to the forward end 101 than the rear end 103 of the scanner housing. The forward edge of the transparent plate member 108 may be e.g. 72 mm from the forward terminal edge of the scanner housing. The rear edge of the transparent plate 108 may be e.g. 160 mm from the rear terminal edge of the scanner housing.
The lower housing member 106 comprises a generally rectangularly shaped bottom wall 110. A front wall 112, rear wall 114 and lateral sidewalls 116, 118 are integrally formed with the bottom wall 110 and project upwardly therefrom. Post members 111, 113 etc. are provided for attaching the upper panel member to the lower housing member. In one preferred embodiment of the invention the overall length of the housing is 575 mm, the lateral dimension of the housing is 408 mm and the distance from the bottom wall 110 to the upper panel member 104 is 105 mm.
As best illustrated in FIG. 2, a longitudinally extending shaft 120, which may be positioned e.g. 36 mm above the housing bottom wall 110 is supported at opposite ends thereof by brackets mounted on the front and rear housing walls 112, 114. Shaft 120 may be located 79 mm from lateral sidewall 118. A longitudinally extending riser 122, which may be integrally formed with the bottom wall 110 may be positioned e.g. 80 mm from lateral sidewall 116. The upper surface of the riser 122 may be positioned e.g. 37 mm above bottom wall 110.
As further illustrated in FIG. 2, an electrical power supply unit 123 is fixedly mounted to the lower housing member between sidewall 116 and riser 122. An electronic controller board 124 is fixedly mounted on bottom wall 110 at a rear end portion thereof. The controller board 124 receives power from power supply unit 123 through power cable 125. The controller board is electrically connected with a light processing assembly 162 mounted in a carriage assembly 140 through an electrical cable 126.
A reversible electric motor 130 which receives power through electrical supply cable 132 connected to controller board 124 is fixedly mounted the bottom wall at a location proximate lateral wall 118 at a rear end portion of the housing member. The reversible electric motor 130 has a vertical motor shaft 134 and is controlled by the controller board. A carriage assembly drive cable 136 has terminal ends thereof wound about vertical motor shaft 134. An intermediate portion of the cable 136 is received about a pulley 138 which is mounted proximate a forward end of the housing.
As best illustrated in FIG. 2, a scanner carriage assembly 140 is longitudinally displaceably mounted on shaft 120 and riser 122. The scanner carriage assembly 140 is attached to cable 136 which produces reciprocal, longitudinal movement thereof.
As best illustrated in FIG. 3, the scanner carriage assembly comprises a carriage body 142 which is preferably constructed from a rigid high strength material, such as aluminum, stainless steel or the like. The body comprises a bottom wall 144 having a two tier structure, including a forward upper tier 145 and rear lower tier 147, as illustrated in FIG. 6. The carriage has a vertical rear wall 146, a vertical first lateral sidewall 148 and a vertical second lateral sidewall 150, FIG. 3. The overall longitudinal dimension of carriage body 142 may be e.g. 146 mm. The maximum width of the carriage body 142 may be e.g. 244 mm.
First and second guide ring members 152, 154, FIGS. 2 and 3, are fixedly attached to the carriage body 142 and are adapted to slidingly receive longitudinally extending shaft 120. A vertically and longitudinally extending guide member 156, which may be integrally formed with lateral sidewall 150, is adapted to be positioned adjacent to an outboard portion of riser 122. The bottom wall 144 of the carriage body is slidingly supported on riser 122. Guide member 156 ensures proper longitudinal tracking of the carriage body 142 along the vertical riser 122.
A centrally mounted support block 160 is fixedly attached to bottom wall 144, FIG. 6. A light processing assembly 162 is fixedly attached to support block 160. The light processing assembly 162 in one preferred embodiment comprises a dual trichromatic beam splitter and photosensor assembly which may be identical to the type described in U.S. Pat. No. 4,806,750 of Kent D. Vincent, which is hereby specifically incorporated by reference for all that is disclosed therein. A double convex lens assembly 164 is adjustably mounted at a position directly forward of light processing assembly 162 by a tubular mounting assembly 166. In one preferred embodiment of the invention the double convex lens 164 assembly comprises a lens having a 31 mm diameter, a 42 mm focal length, and a magnification of 0.126.
As best illustrated by FIGS. 4 and 6, a modular light source and light slit or aperture assembly 170 is stationarily mounted at a forward location on the carriage body 140. In the preferred embodiment of the invention illustrated by the drawings, the lateral sidewalls 148, 150 each comprise a forward cut-out region therein which define horizontal surfaces 172, 174 adapted to support assembly 170. A locking assembly 171 is associated with each support surface 172, 174 and is adapted to cooperate with a catch assembly (not shown) provided on a lower surface of the modular light source and light slit assembly 170 to hold assembly 170 in stationary relationship with the carriage body at a predetermined location thereon.
The modular light source and light slit assembly 170 comprises an elongate member 176 having a generally W-shaped cross-section, as shown by FIG. 6. The elongate member 176 has a forward portion 178 having generally U-shaped cross-section which is adapted for supporting a first fluorescent bulb 180 which may have a diameter of 15.5 mm. The elongate member 176 also comprises a rear portion 182 having a generally U-shaped cross-section for supporting a second fluorescent bulb 184. The elongated member 176 has a central riser portion 186. A narrow light slit or aperture 188 is located at the top of riser portion 186 and extends substantially the full length thereof. The light slit 188 communicates with a generally inverted V-shaped cavity 190 within the central riser portion 186. The inverted V-shaped cavity 190 also extends substantially the full length of the riser. The narrow slit 188 may comprise a length, measured transversely with respect to the housing longitudinal axis AA, of 234 mm. The slit width, measured parallel to axis AA, may be e.g. 0.8 mm. The inverted V-shaped cavity may have a width at the upper end thereof of e.g. 0.8 mm and a width at the bottom end thereof of e.g. 7.5 mm and may have a height of e.g. 215 mm. The surface of the inverted V-shaped cavity 190 may have a generally inverted stair step shape, each inverted stair step having a height of e.g. 2 mm and a horizontal dimension of, e.g., 0.2 mm. An electrical socket member 194, FIG. 4, is fixedly attached to one end of elongate member 176 and comprises two conventional fluorescent bulb female sockets therein adapted to receive conventional male socket portions of fluorescent bulbs 180 and 184, respectively. A flexible power cable 196 is operably attached to socket member 194 for providing electrical current to bulbs 180, 184. Independent end sockets 198, 200 are provided at the end of each fluorescent bulb and make electrical contact with male socket portions thereof. Each socket 198, 200 is connected by a pair of lead wires 202, 204 to an associated portion of socket member 194. Shield members 193, 195 (shown in FIG. 6 only) may be provided to reflect light from the bulbs 180, 184 toward an object such as color document 208, which is to be scanned.
Light slit 188 passes light reflected from a narrow band region 206 of document 208 and blocks all other light reflected from the document, FIG. 6. The region 206 from which light is reflected of course changes as scanner carriage assembly 140 moves relative to document 208. However, for purposes of explaining image formation, etc., it is helpful to visualize the scanner carriage assembly 140 and narrow band region 206 in a static position. Narrow band region 206 is sometimes referred to herein as "scan line" or "scan object" 206.
As illustrated by FIG. 6, some of the light from fluorescent bulbs 180, 184, which is reflected from a narrow band scan region 206 of document 208 and which ultimately enters lens 165 travels along a light path 210 which passes through slit 188 and inverted V-shaped cavity 190. Light path 210 is thereafter "folded" by a first mirror 212, a second mirror 214 and a third mirror 216 before passing through focusing lens 165. Light path 210 thereafter passes through tubular member 166 into light processing assembly 162 and terminates at photosensor assembly 252 therein, FIG. 9. Each mirror 212, 214, 216 may have a width of e.g. 127 mm and is held in position by a pair of mounting assemblies, e.g. 220, 221, FIG. 5, which may comprise a bracket member 222 which is fixedly attached to an associated lateral sidewall of the carriage assembly and a clip member 224 which attaches an end portion of each mirror to the associated bracket members 222. In the case of mirror 214, a mirror angular adjustment assembly 226 is also provided for adjusting the relative angular position of mirror 214 about an axis extending perpendicularly of axis AA. The mirror mounting assemblies may be identical to those which are specifically described in U.S. patent application Ser. No. 345,384, filed May 1, 1989, of David Wayne Boyd, which is hereby specifically incorporated by reference for all that is disclosed therein.
As best illustrated in FIGS. 5 and 6, light path 210 comprises a first vertically downwardly extending light path portion 238 extending between scanned document 208 and light slit 188; a second vertically downwardly extending light path portion 240 extending from slit 188 to mirror 212; a third generally rearwardly and upwardly extending light path portion 242 extending between mirror 212 and mirror 214; a fourth generally downwardly and forwardly extending light path portion 244 extending between mirror 214 and mirror 216; and a fifth generally rearwardly extending light path portion 246 extending between mirror 216 and the forward surface of lens 165.
Another embodiment of an aperture and light source assembly 310 is illustrated in FIGS. 7-11. The aperture and light source assembly 310 is used in association with an optical scanner carriage 312 having a cover plate 314 thereon which may be similar or identical in construction to the carriage assembly 140 described above. As best illustrated in FIG. 9, the aperture and light source assembly comprises an elongate aperture plate 320 having a first horizontally extending portion 322, a second horizontally extending portion 324, a first upwardly projecting flange portion 326 integrally formed with the first horizontally extending portion 322, a second upwardly projecting flange portion 328 integrally formed with the second horizontally extending portion 324, and a central vertical portion 330 integrally formed with the horizontally extending portions 322, 324. The central vertical portion 330 comprises a generally inverted V-shaped interior cavity 322, which may be identical to cavity 190 described above, which is intersected by a longitudinally extending slit 334 provided at a top end portion 336 of the central vertical portion 330. The elongate aperture plate 320 may be supported on a recessed peripheral structure (not shown) provided on carriage 312 which enables drop-in mounting of the elongate plate on the carriage.
As best illustrated in FIGS. 7, 8 and 10, the aperture and light source assembly 310 also comprises a light source assembly 340 which includes first and second fluorescent bulbs 342, 352 which are adapted to be positioned adjacent first and second lateral sides 337, 338 of the central vertical portion 330 of the elongate aperture plate 320. The first fluorescent bulb 342 comprises a first end 344, a second end 346, and has a pair of first end male electrical terminals 348 and a pair of second end male electrical terminals 350 of conventional construction. The second fluorescent bulb similarly comprises a first end 354, a second end 356, and a first and second pair of male terminals 358, 360 thereon. Electrical lead cables 361-366 are soldered to each of the second end male terminals of each terminal pair 346, 356 and to one of the first end male terminals in each terminal pair 344, 354. A seventh electrical cable 368 is connected to one male electrical terminal of the first bulb first end terminal pair 348 and to one terminal on the second bulb first end terminal pair 358. By soldering the leads directly to the terminals in this fashion, the need for relatively expensive electrical sockets at each end of the bulbs is eliminated. The leads 361-364 attached to the second ends of the bulbs are looped back and extended parallel to and below each associated bulb in the direction of the first end and are thereafter grouped together with first end leads 365 and 366 and passed through a first ground strap 370. The leads 361-366 thereafter pass through a lead cable shield 372 which is attached to the first ground strap 370 by a first shield clip 374. The leads 361-366 thereafter pass through a second ground strap 376 which is attached to the second end of the lead cable shield 372 by a second shield clip 378. The six leads thereafter emerge from the ground strap 376 and are electrically attached to a conventional six-contact electrical connector 380 which is in turn connected to power supply 123, FIG. 2.
A first end connector and spacer assembly 382 comprising an upper portion 384 and a lower portion 386 defines a first bulb enclosure 388 and a second bulb enclosure 390 and a lead cable enclosure 392 which extends perpendicular to the first and second bulb enclosure 388, 390. First and second bulb enclosures are provided with channel recesses in lower portions thereof which allow cables 361-364 to be extended therethrough to lead cable enclosure 392. A screw hole 394 (only one shown) is provided in each of the upper and lower portions 384, 386 of the first end connector and spacer assembly and enables the connector and spacer assembly to be attached by means of a screw 396 to a threaded bore 418 in bracket portion 414 of carriage 312, FIG. 9. A second end connector and spacer assembly 402 having a unitary body construction defines a first enclosure 404 for accepting second end 346 of first bulb 342 therein and comprises a second enclosure 406 for accepting the second end 356 of second fluorescent bulb 352 therein. Recesses are provided in the lower portion of each of the enclosures 404, 406 for accommodating cables 361-364. A screw hole 408 is provided in second end connector and spacer assembly 402 for enabling attachment of the assembly to a carriage second end bracket 412 having a threaded bore 416 therein by means of threaded screw 410.
Screw 396 which attaches first connector and spacer assembly 382 to carriage bracket 412 also connects a screw receiving portion such as 379 of the first ground strap 370 to the carriage, thus grounding the end strap on the carriage. In a preferred embodiment of the invention, the first and second end connector and spacer assemblies 382, 402 are constructed from molded plastic, and the elongate aperture plate 320 is constructed from die case aluminum. The diameter of each of the bulbs 342, 352 is sufficiently small to prevent the bulbs from extending above the light slit 334. The dimensions of the first and second end connector and spacer assemblies 382 and 402 are such that each of the bulbs is positioned a small distance, e.g. 2.4 mm, above an associated horizontally extending portion 322, 324 of the elongate aperture plate 320. The spacing between the bulb and the aperture plate accommodates the extension of cables 361-364 therebetween.
While an illustrative and presently preferred embodiment of the invention has been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
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An aperture and light source assembly including an elongate aperture plate having a longitudinally extending, aperture defining slit at a top end thereof and a light source for illuminating an object to be scanned including a first elongate bulb and a second elongate bulb positioned adjacent opposite lateral sides of the vertically disposed portion of said aperture plate and below the top end slit therein; a connector and spacer assembly fixedly connecting the bulbs in spaced apart, parallel relationship; and an attachment assembly associated with the connector assembly removably attaching the light source to the optical scanner; and whereby the first and second bulbs are installable and removable from the optical scanner as a modular unit.
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BACKGROUND OF THE INVENTION
[0001] This invention generally relates to mosaic arrays of ultrasound transducer elements and to the use of micromachined ultrasonic transducers (MUTs) in arrays. One specific application for MUTs is in medical diagnostic ultrasound imaging systems.
[0002] Conventional ultrasound imaging systems comprise an array of ultrasonic transducers that are used to transmit an ultrasound beam and then receive the reflected beam from the object being studied. Such scanning comprises a series of measurements in which the focused ultrasonic wave is transmitted, the system switches to receive mode after a short time interval, and the reflected ultrasonic wave is received, beamformed and processed for display. Typically, transmission and reception are focused in the same direction during each measurement to acquire data from a series of points along an acoustic beam or scan line. The receiver is dynamically focused at a succession of ranges along the scan line as the reflected ultrasonic waves are received.
[0003] For ultrasound imaging, the array typically has a multiplicity of transducers arranged in one or more rows and driven with separate voltages. By selecting the time delay (or phase) and amplitude of the applied voltages, the individual transducers in a given row can be controlled to produce ultrasonic waves that combine to form a net ultrasonic wave that travels along a preferred vector direction and is focused in a selected zone along the beam.
[0004] The same principles apply when the transducer probe is employed to receive the reflected sound in a receive mode. The voltages produced at the receiving transducers are summed so that the net signal is indicative of the ultrasound reflected from a single focal zone in the object. As with the transmission mode, this focused reception of the ultrasonic energy is achieved by imparting separate time delay (and/or phase shifts) and gains to the signal from each receiving transducer. The time delays are adjusted with increasing depth of the returned signal to provide dynamic focusing on receive.
[0005] The quality or resolution of the image formed is partly a function of the number of transducers that respectively constitute the transmit and receive apertures of the transducer array. Accordingly, to achieve high image quality, a large number of transducers is desirable for both two- and three-dimensional imaging applications. The ultrasound transducers are typically located in a hand-held transducer probe that is connected by a flexible cable to an electronics unit that processes the transducer signals and generates ultrasound images. The transducer probe may carry both ultrasound transmit circuitry and ultrasound receive circuitry.
[0006] Recently semiconductor processes have been used to manufacture ultrasonic transducers of a type known as micromachined ultrasonic transducers (MUTs), which may be of the capacitive (MUT) or piezoelectric (pMUT) variety. MUTs are tiny diaphragm-like devices with electrodes that convert the sound vibration of a received ultrasound signal into a modulated capacitance. For transmission the capacitive charge is modulated to vibrate the diaphragm of the device and thereby transmit a sound wave.
[0007] One advantage of MUTs is that they can be made using semiconductor fabrication processes, such as microfabrication processes grouped under the heading “micromachining”. As explained in U.S. Pat. No. 6,359,367:
[0008] Micromachining is the formation of microscopic structures using a combination or subset of (A) Patterning tools (generally lithography such as projection-aligners or wafer-steppers), and (B) Deposition tools such as PVD (physical vapor deposition), CVD (chemical vapor deposition), LPCVD (low-pressure chemical vapor deposition), PECVD (plasma chemical vapor deposition), and (C) Etching tools such as wet-chemical etching, plasma-etching, ion-milling, sputter-etching or laser-etching. Micromachining is typically performed on substrates or wafers made of silicon, glass, sapphire or ceramic. Such substrates or wafers are generally very flat and smooth and have lateral dimensions in inches. They are usually processed as groups in cassettes as they travel from process tool to process tool. Each substrate can advantageously (but not necessarily) incorporate numerous copies of the product. There are two generic types of micromachining . . . 1) Bulk micromachining wherein the wafer or substrate has large portions of its thickness sculptured, and 2) Surface micromachining wherein the sculpturing is generally limited to the surface, and particularly to thin deposited films on the surface. The micromachining definition used herein includes the use of conventional or known micromachinable materials including silicon, sapphire, glass materials of all types, polymers (such as polyimide), polysilicon, silicon nitride, silicon oxynitride, thin film metals such as aluminum alloys, copper alloys and tungsten, spin-on-glasses (SOGs), implantable or diffused dopants and grown films such as silicon oxides and nitrides. The same definition of micromachining is adopted herein.
[0009] There is a continuing need for improvements in the design of ultrasound transducer arrays. The complexity of today's ultrasound imaging system has to be high in order to achieve excellent image quality. Conventional probes typically have 128 signal processing channels (and for arrays with electronic elevation focusing, an increase by a factor as high as five). Also, the potential for making the correct clinical diagnosis with most imaging modalities (including ultrasound) will benefit by a thinner slice thickness. The implementation of a dynamically focused beam both in elevation and azimuth is very complex and expensive, especially for general imaging (as opposed to echocardiac) applications. Also the volume and power consumed by the electronics is prohibitive to making such a system easily portable.
BRIEF DESCRIPTION OF THE INVENTION
[0010] The present invention employs the idea of dividing the active aperture of an ultrasound transducer into a mosaic of very small subelements and then forming elements from these subelements by interconnecting them with electronic switches. These elements can be “moved” electronically along the surface of the mosaic array to perform scanning by changing the switch configuration. Other element configurations permit beamsteering, which will provide the ability to acquire volumetric data sets. A configuration of multiple concentric annular elements provides optimal acoustic image quality by matching the element shapes to the acoustic phase fronts. One aspect of the invention is the reconfigurability of the resulting array.
[0011] It is these capabilities to both reconfigure elements and to have elements match phase fronts that significantly reduce the number of elements (or channels) needed to achieve high-end system image quality. With fewer channels the number of signals that need to be processed by beamforming electronics is also dramatically reduced. Therefore the volume and power consumption of system electronics for a mosaic array is compatible with highly portable ultrasound systems.
[0012] One aspect of the invention is a mosaic array comprising a multiplicity of subelements, each of the subelements comprising a respective multiplicity of micromachined ultrasound transducer (MUT) cells, and each MUT cell comprising a top electrode and a bottom electrode. The top electrodes of the MUT cells making up any particular subelement are hard-wired together, while the bottom electrodes of those same MUT cells are likewise hard-wired together.
[0013] Another aspect of the invention is an ultrasound transducer array comprising a multiplicity of subelements interconnected by a multiplicity of microelectronic switches, each subelement comprising a respective multiplicity of MUT cells, and each MUT cell within a particular subelement being hard-wired together.
[0014] A further aspect of the invention is a method of making an ultrasound transducer, comprising the following steps: fabricating a substrate having a multiplicity of microelectronic switches therein; and micromachining a multiplicity of MUT cells on the substrate, the MUT cells being interconnected in clusters, each cluster of interconnected MUT cells being connected to a respective one of the microelectronic switches.
[0015] Yet another aspect of the invention is an ultrasound transducer comprising: a multiplicity of MUT cells, each MUT cell comprising a respective top electrode and a respective bottom electrode, wherein the top electrodes of the MUT cells are hard-wired together and the bottom electrodes of the MUT cells are hard-wired together; a microelectronic switch having an output terminal connected to the interconnected top electrodes or to the interconnected bottom electrodes; and a driver circuit having an output terminal connected to an input terminal of the microelectronic switch for driving the multiplicity of MUT cells to generate ultrasound waves when the microelectronic switch is turned on.
[0016] Other aspects of the invention are disclosed and claimed below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a drawing showing a cross-sectional view of a typical cMUT cell.
[0018] [0018]FIG. 2 is a drawing showing a “daisy” subelement formed from seven hexagonal MUT cells having their top and bottom electrodes respectively hard-wired together.
[0019] [0019]FIG. 3 is a drawing showing a “hexagonal” subelement formed from 19 hexagonal MUT cells having their top and bottom electrodes respectively hard-wired together.
[0020] [0020]FIG. 4 is a drawing showing a sector of a mosaic array comprising four annular elements in accordance with one embodiment of the invention, each element consisting of a tessellation of “daisy” subelements configured to have approximately equal area per element.
[0021] [0021]FIG. 5 is a drawing showing a sector of a mosaic array comprising six annular elements in accordance with another embodiment of the invention, each element consisting of a tessellation of “daisy” subelements configured to have approximately equal area per element.
[0022] [0022]FIG. 6 is a drawing showing a sector of a mosaic array comprising four elements in accordance with yet another embodiment of the invention, each element consisting of a tessellation of “hexagonal” subelements.
[0023] [0023]FIG. 7 is a drawing showing a sector of a mosaic array comprising six elements in accordance with a further embodiment of the invention, each element consisting of a tessellation of “hexagonal” subelements.
[0024] [0024]FIG. 8 is a drawing showing a tessellation of “daisy” subelements separated by gaps for reduction of signal cross talk
[0025] [0025]FIG. 9 is a drawing showing a tessellation of “hexagonal” subelements separated by gaps for reduction of signal cross talk
[0026] [0026]FIG. 10 is a schematic of a cascade of high-voltage switching circuits for selectively driving ultrasound transducers of a mosaic array in accordance with one embodiment of the invention.
[0027] Reference will now be made to the drawings in which similar elements in different drawings bear the same reference numerals.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The innovation disclosed here is a unique method of implementing a mosaic array with micromachined ultrasound transducers (MUTs). For the purpose of illustration, various embodiments of the invention will be described that utilize capacitive micromachined ultrasonic transducers (cMUTs). However, it should be understood that the aspects of the invention disclosed herein are not limited to use of cMUTs, but rather may also employ pMUTs or even diced piezoceramic arrays where each of the diced subelements are connected by interconnect means to an underlying switching layer.
[0029] cMUTs are silicon-based devices that comprise small (e.g., 50 μm) capacitive “drumheads” or cells that can transmit and receive ultrasound energy. Referring to FIG. 1, a typical MUT transducer cell 2 is shown in cross section. An array of such MUT transducer cells is typically fabricated on a substrate 4 , such as a silicon wafer. For each MUT transducer cell, a thin membrane or diaphragm 8 , which may be made of silicon nitride, is suspended above the substrate 4 . The membrane 8 is supported on its periphery by an insulating support 6 , which may be made of silicon oxide or silicon nitride. The cavity 20 between the membrane 8 and the substrate 4 may be air- or gas-filled or wholly or partially evacuated. A film or layer of conductive material, such as aluminum alloy or other suitable conductive material, forms an electrode 12 on the membrane 8 , and another film or layer made of conductive material forms an electrode 10 on the substrate 4 . Alternatively, the electrode 10 can be embedded in the substrate 4 . Also the electrode 12 can be on top of membrane 8 rather than embedded within it as shown in FIG. 1.
[0030] The two electrodes 10 and 12 , separated by the cavity 20 , form a capacitance. When an impinging acoustic signal causes the membrane 8 to vibrate, the variation in the capacitance can be detected using associated electronics (not shown in FIG. 1), thereby transducing the acoustic signal into an electrical signal. Conversely, an AC signal applied to one of the electrodes will modulate the charge on the electrode, which in turn causes a modulation in the capacitive force between the electrodes, the latter causing the diaphragm to move and thereby transmit an acoustic signal.
[0031] In operation, the MUT cell typically has a dc bias voltage V bias that is significantly higher than the time-varying voltage v(t) applied across the electrodes. The bias attracts the top electrode toward the bottom through coulombic force. In this heavily biased case, the MUT drumheads experience a membrane displacement u given as follows:
u ( t ) ≈ ɛ d 2 * V bias * v ( t ) ( 1 )
[0032] where d is the distance between the electrodes or plates of the capacitor, and å is the effective dielectric constant of the cell. The sensitivity of the MUT cell has been found to be the greatest when the bias voltage is high and electrodes are closer together.
[0033] Due to the micron-size dimensions of a typical MUT, numerous MUT cells are typically fabricated in close proximity to form a single transducer element. The individual cells can have round, rectangular, hexagonal, or other peripheral shapes. Hexagonal shapes provide dense packing of the MUT cells of a transducer element. The MUT cells can have different dimensions so that the transducer element will have composite characteristics of the different cell sizes, giving the transducer a broadband characteristic.
[0034] MUT cells can be hard-wired together in the micromachining process to form subelements, i.e., clusters of individual MUT cells grouped in some presumably intelligent fashion (the term “subelement” will be used in the following to describe such a cluster). These subelements will be interconnected by microelectronic switches (as opposed to hard-wired) to form larger elements, such as annuli, by placing such switches within the silicon layer upon which the MUT subelements are built. This construction is based on semiconductor processes that can be done with low cost in high volume.
[0035] There are many methods of designing the mosaic to get the best acoustic performance. For example, one can match phase fronts on both transmit and receive; provide a gap between adjacent subelements to reduce element-to-element cross talk; choose various subelement patterns to form a tessellation of the mosaic grid; and choose various elemental patterns for transmit and receive for maximal acoustic performance in specific applications.
[0036] In accordance with the embodiments disclosed herein, the transducer is fabricated using an array of MUT subelements that can be interconnected in numerous ways to provide specific acoustic output with regards to beam direction, focal location, and minimal sidelobes and grating lobes.
[0037] For the purpose of illustration, FIG. 2 shows a “daisy” subelement 14 made up of seven hexagonal MUT cells 2 : a central cell surrounded by a ring of six cells, each cell in the ring being contiguous with a respective side of the central cell and the adjoining cells in the ring. The top electrodes of each cell are hardwired together. Similarly, the bottom electrodes of each cell are hardwired together, forming a seven-times-larger capacitive subelement.
[0038] An alternative “hexagonal” subelement 16 is shown in FIG. 3 and is made up of 19 MUT cells. The top electrodes of the cells in each group are hardwired together; similarly, the bottom electrodes of the cells in each group are connected, thus forming a larger capacitive subelement. Since the MUT cell can be made very small, it is possible to achieve very fine-pitch mosaic arrays.
[0039] There are numerous ways in which one can form transducer arrays using MUT cells and subelements that fall within the scope of the present invention. FIGS. 4 and 5 show examples of tessellations of subelements to form mosaic arrays. In the embodiment shown in FIG. 4, four approximately annular elements (referenced by numerals 22 , 24 , 26 and 28 respectively), each comprising a tessellation of “daisy” subelements (seven MUT cells hardwired together per subelement), are configured to have approximately equal area per element. In the embodiment shown in FIG. 5, six approximately annular elements (referenced by numerals 30 , 32 , 34 , 36 , 38 and 40 respectively), each comprising a tessellation of “daisy” subelements, are configured to have approximately equal area per element. The tessellation in each case can be made up of multiple subelement types. The array pattern need not be a tessellation, but can have areas without acoustical subelements. For instance, there could be vias to bring top electrode connections of the MUT subelement or cells below the array.
[0040] The configurations of the invention can be changed to optimize various acoustic parameters such as beamwidth, sidelobe level, or depth of focus. Alternatively, the subelements could be grouped to form one aperture for the transmit operation and immediately switched to another aperture for the receive portion. While FIGS. 4 and 5 show approximately annular elements, other configurations can be implemented, for example, non-continuous rings, octal rings, or arcs. The choice of pattern will depend on the application needs.
[0041] [0041]FIGS. 6 and 7 illustrate some examples of elemental patterns comprising a tessellation of “hexagonal” subelements. The embodiment shown in FIG. 6 has four elements (referenced by numerals 42 , 44 , 46 and 48 respectively), each element comprising a tessellation of “hexagonal” subelements (19 MUT cells hardwired together per subelement). The elements are not circular. In particular, the third element is a non-continuous ring or, more precisely, a plurality of “hexagonal” subelements circumferentially distributed at equal angular intervals. The embodiment shown in FIG. 7 has six elements (referenced by numerals 50 , 52 , 54 , 56 , 58 and 60 respectively), each element consisting of a tessellation of “hexagonal” subelements. In this embodiment, the fourth element is a non-continuous ring, while the first (i.e., central) element is hexagonal rather than circular.
[0042] It should be understood that the patterns shown in FIGS. 4-7 are for illustrative purposes only. Numerous other patterns can be defined and this disclosure is not intended to limit the innovation to the ones explicitly shown.
[0043] In the case of mosaic annular arrays, the annuli enable a dramatic reduction in the number of signals that have to be processed by the beamforming electronics. For example, if the cMUT cells are distributed into an eight-element annular array, this means that the beamforming electronics will have to deal only with the eight signals output by those annuli. This is in sharp contrast to the case of conventional probes in which the number of signal processing channels is typically 128 (and for arrays with electronic elevation focusing, that number multiplied by a factor of five).
[0044] In accordance with a further aspect of the invention, cross talk between elements in a reconfigurable array can be reduced by introducing a small gap between subelements. FIG. 8 shows a tessellation of “daisy” subelements 14 wherein each “daisy” subelement is separated from adjacent subelements by a gap 62 . FIG. 9 shows a tessellation of “hexagonal” subelements 16 wherein each “hexagonal” subelement is separated from adjacent subelements by a gap 64 . For further cross-talk reduction, a trench into the silicon substrate around each subelement could be implemented.
[0045] The subelements (“daisy”, “hexagonal”, or other shape) may be connected dynamically using switches beneath the array, making possible the formation of arbitrary elemental patterns or, in other words, a reconfigurable array. While these switches can be separately packaged components, it is possible to actually fabricate the switches within the same semiconductor substrate on which the MUT array is to be fabricated. The micromachining process used to form the MUT array will have no detrimental effect on the integrated electronics.
[0046] In accordance with one aspect of the invention, it is possible to reduce the number of high-voltage switches by using pulser circuits that may be made small due to the very limited current the high-impedance MUTs require.
[0047] Each MUT subelement may be driven by a high-voltage switching circuit comprising two DMOS FETs that are connected back to back (source nodes shorted together; see switches X 1 -X 3 in FIG. 10) to allow for bipolar operation. Such a switching circuit is disclosed in U.S. patent application Ser. No. 10/______ entitled “Integrated High-Voltage Switching Circuit for Ultrasound Transducer Array”. In that switching circuit, current flows through the switch terminals whenever both FETs are turned on. To turn on the switch, the gate voltage of these devices must be greater than their source voltage by a threshold voltage. Above the threshold voltage, switch on resistance varies inversely with the gate voltage. Since the source voltage will be close to the drain voltage (for low on resistance and low current), the source voltage will track the ultrasound transmit pulse voltage. In order for the gate-source voltage to remain constant, the gate voltage must also track the transmit pulse voltage. This can be achieved by isolating the source and gate from the switch control circuitry and providing a fixed potential at the gate with reference to the source. This is preferably achieved using dynamic level shifters.
[0048] U.S. patent application Ser. No. 10/______ discloses a turn-on circuit comprising a high-voltage PMOS transistor whose drain is connected to a common gate of the DMOS FETs via a diode. The gate of the PMOS transistor receives the switch gate turn-on voltage V p . The source of the PMOS transistor is biased at a global switch gate bias voltage (nominally 5 V). In order to turn on the switch, the gate voltage V p of the PMOS transistor is transitioned from high (5 V) to low (0 V), causing the global bias voltage to be applied through the PMOS transistor to the shared gate terminal of the DMOS FETs. The diode is provided to prevent the PMOS transistor from turning on when the switch gate voltage V p drifts above the global switch gate bias voltage. Once the switch gate voltage V p has reached the switch gate bias voltage, the parasitic gate capacitance of the DMOS FETs will retain this voltage. For this reason, once the gate voltage V p has stabilized, the PMOS transistor can be turned off to conserve power. The fact that the switch ON state is effectively stored on the switch gate capacitance means that the switch has its own memory.
[0049] This switching circuit can be used as part of a cascade of switches, as shown in FIG. 10 (taken from the above-cited patent application, Ser. No. 10/______). The exemplary cascade shown in FIG. 10 comprises three switches X 1 , X 2 and X 3 connected in series, although it should be understood that more than three switches can be cascaded in the manner shown. The states of the switches X 1 through X 3 are controlled by respective switch control circuits C 1 through C 3 . There is a digital circuit (not shown) that controls the gate turn-off voltage V N and the gate turn-on voltage V p . This digital circuit has local memory of the state of the switch. An external control system (programming circuit 68 in FIG. 10) programs all of the switch memories to be in either the ON, OFF or NO_CHANGE state. Then a global select line 70 (see FIG. 10) is used to apply the state to the actual switch control circuit. So until the select line is actuated, V N and V p are both zero. In this state the switch itself retains its last state. When the global select line 70 is actuated, the stored switch state is transferred to the switch itself by either bringing V N high (turn off the switch), V p low (turn on the switch), or V N and V p both low (no change to the switch state). The global switch gate bias voltage terminals of each switch X 1 -X 3 in FIG. 10 are connected to a bus 72 . The global select line 70 , in conjunction with the global switch gate bias voltage bus 72 , allow the turn-on voltage of each switch X 1 -X 3 to be programmed independently. More specifically, each switch can be programmed with its own unique gate turn-on voltage that can be used to adjust the switch-on resistances of all switches in the array to correct for variation due to processing.
[0050] Still referring to FIG. 10, a first ultrasound transducer U 1 can be driven by the ultrasound driver 66 when switch X 1 is turned on; a second ultrasound transducer U 2 can be driven by the ultrasound driver 10 when switches X 1 and X 2 are both turned on; and a third ultrasound transducer U 3 can be driven by the ultrasound driver 10 when switches X 1 , X 2 and X 3 are all turned on. Each ultrasound transducer can be a subelement of one of the types disclosed herein.
[0051] I. Applications for Reconfigurable MUT-Based Mosaic Array
[0052] The present invention exploits the concept of reconfigurability of arrays. The following examples are not intended to cover the entire set of possibilities that can be taken advantage of but rather are given for illustrative purposes.
[0053] a. Annular Arrays
[0054] With known non-mosaic annular arrays, the usual custom is to build them with an equal-area approximation in which the center element and the annuli all have an equal area. This approach forces the phase shift across each element to be constant. It also makes all the element impedances uniform, thereby giving equal loading to the circuitry driving and receiving from them. This helps the spectral content of each element to be nearly uniform and therefore maximizes the coherence of the transmit and receive beamformation processes.
[0055] However, computer simulations show that the equal-area approach limits the near-field performance of the array due to limited number of elements that come into play in the near field. One alternative design is called the constant f-number design, which is intended for flat (non-prefocused) annular arrays. With this approach there is an attempt to maintain a constant f-number over the range of interest until one runs out of aperture. These designs and other variants are readily implemented with the reconfigurable arrays of MUT subelements disclosed herein.
[0056] b. Non-Annular Arrays
[0057] It should be recognized that the reconfigurability of MUTs permits great generality in the shape and size of a mosaic array element. Certain clinical applications may call for other configurations such as elliptical designs (in case elevation lensing is used) or possible sparse array designs.
[0058] c. Different Configurations on Transmit Versus Receive
[0059] Integrated electronics within the MUT array substrate provide the capability to switch the array elemental pattern or configuration quickly. One advantage this brings to bear on acoustic performance is the ability to have a different aperture for transmit than for receive. On transmit the optimal aperture for a fixed focal depth can be configured, whereas on receive an aperture appropriate for a dynamically changing focus (or aperture or apodization) can be implemented. This is not limited to changing the size of the aperture (e.g., all system channels can be used on both transmit and receive).
[0060] d. Beam Steering
[0061] A reconfigurable array allows for the possibility of steering beams by grouping together those subelements that have similar delay values for the given beam. While a broadside beam will have groupings shaped like annular rings, beams steered away from the perpendicular have arc-shaped groupings.
[0062] The beam can be steered three-dimensionally, that is, in both the azimuthal and elevational directions. The added value of the reconfigurable design is that these steered beams can be accomplished with fewer system channels since a typical phased array heavily oversamples the acoustic field at shallow steering angles. Thus beam steering can be achieved with a limited number of channels by effectively grouping together elements in the mosaic design according to the time delay needed. The number of discrete delays needed is related to the level of sidelobes that arise as one increases the coarseness of the spatial sampling.
[0063] II. Acoustic Performance Enhancements
[0064] a. Subelement-to-Subelement Bias Voltage Variation
[0065] It is well known that abrupt changes in amplitude at the transmitting aperture generate higher-amplitude sidelobes via a Gibbs phenomenon-related process. With one-dimensional arrays, most manufacturers apply a weighting (or apodization) to reduce these sidelobes. With mosaic annular arrays that transmit in a perpendicular direction with respect to the surface of the array, apodization can be applied to the individual rings of the array. This is no longer possible with a beam-steered mosaic annular array since a constant amplitude would have to be applied to each of the arcs and these arcs end at the edges of the mosaic annular array aperture. To get around this problem, the bias voltage across the aperture can be modified to generate a spherical (or other shape) modulation across the MUT cells and thereby vary the beamformation process as desired. In general this will mean controlling the bias voltage across the active aperture. Once again, the discreteness of this control will be determined by the desired beam quality and the circuit complexity that can be tolerated. Using the bias voltage to establish the form of apodization, even if one is using annular rings, there is more control over the apodization because the shape of the apodizing function is determined by the subelements, not the annular rings.
[0066] Furthermore, due to process variations the acoustic sensitivity of subelements may not be uniform across the array. Because sensitivity is dependent on bias voltage, independently adjusting this voltage for each subelement can compensate for the sensitivity variation.
[0067] b. Adaptive Acoustics
[0068] The quality of the beam formation can be examined periodically by isolating the echoes received by any subelement (or group of subelements) in the array and comparing the temporal relation of the echoes with those of the sum from all the mosaic array elements (the beamsum). That subelement (or group) can then be reassigned to a different annulus or arc depending on its phase or time delay relation to the beamsum signal.
[0069] c. Harmonics
[0070] The mosaic arrays disclosed herein also provide the benefits of high bandwidth. It is expected that the use of mosaic arrays, especially in the mosaic annular configuration, will yield higher amounts of harmonic energy than achievable with rectangular apertures due to the greater control over the acoustic field that is possible. It is further anticipated that this additional harmonic energy will be more readily detected due to the wide bandwidth of MUTs.
[0071] With respect to broad bandwidth performance, the likelihood of third harmonic imaging is far superior with the mosaic array approach disclosed herein (current systems only use the second harmonic).
[0072] Moreover, the mosaic arrays disclosed herein provide beam shape advantages. Techniques such as tissue characterization will gain directly from the use of wide-bandwidth devices such as MUTs. This is because the tissue characteristics are better sampled due to the excellent resolution.
[0073] In summary, the invention disclosed herein provides superior beam performance, including reduced slice thickness, dynamically focused beams in elevation and reconfigurability of the array to improve acoustic performance or for specific clinical situations. The invention also reduces system complexity arising out of channel count decreases, leading to reduced power consumption, reduced cost and increased portability.
[0074] The combination of MUT technology with mosaic arrays provides the capability to reconfigure fine-pitch elements to match acoustic phase fronts necessary for excellent image quality across many different ultrasound applications. The MUT cells are also nonresonant structures. As a consequence, they are able to operate over a far wider frequency range than conventional piezoceramic arrays. The mosaic array technology will provide real-time two-dimensional and electronically driven three-dimensional imaging with much finer beam shaping and control than present state-of-the-art arrays.
[0075] While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the invention without departing from the essential scope thereof. Therefore it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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An ultrasound transducer array includes a multiplicity of subelements interconnected by a multiplicity of microelectronic switches, each subelement comprising a respective multiplicity of micromachined ultrasound transducer (MUT) cells. The MUT cells within a particular subelement are hard-wired together. The switches are used to configure the subelements to form multiple concentric annular elements. This design dramatically reduces complexity while enabling focusing in the elevation direction during ultrasonic image data acquisition.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 09/944,946, filed Aug. 31, 2001, which claims priority from Japanese Application No. 2000-300563, filed Sep. 28, 2000, both of which are fully incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a storage control apparatus, and more particularly to a technique for a load balance control system between a computer and the storage control apparatus performing I/O processing with that computer.
[0004] 2. Description of the Related Art
[0005] In recent computer systems, the overall performance can easily be limited by the I/O processing of the storage control apparatus. As a result, for I/O from a computer, the storage control apparatus must execute each I/O process at the maximum capacity possible with that storage control apparatus. Also, the storage control apparatus must simultaneously execute the I/O processing requests from a plurality of computers and through a plurality of paths.
[0006] In general, cache memory is used as means for improving the performance of a storage control apparatus. I/O processing performance can thereby be improved by leaving frequently accessed data in a cache as much as possible with a least recently used (LRU) algorithm control or the like. In some cases, however, the expected I/O processing performance is not attained because the data left in the cache is not necessarily frequently accessed data, and the cache hit rate does not rise due to the access data pattern in the I/O processing.
[0007] Means for resolving this type of problem include, for example, the technology disclosed in Japanese Patent Laid-open Publication No. H08-263380. In this approach, the access history from the host is recorded and analyzed and effective data is left in the cache for a long period, but data that is cached but judged to be meaningless is actively removed from the cache. The cache hit rate thereby increases and I/O processing performance improves.
BRIEF SUMMARY OF THE INVENTION
[0008] The technology disclosed in the above mentioned report is an effective measure, especially when usable cache memory resources are available. As the I/O processing load increases, however, waiting time for securing usable cache memory resources develops and the I/O processing throughput decreases because the above-mentioned cache memory resources are used over the above-mentioned plurality of paths. Also, waiting time for securing cache memory resources develops in the case where a plurality of computers require the same cache memory resources at the same time. In the case of competition for securing cache memory resources between high and low I/O processing priority computers at work, the processing of the lower I/O processing priority computer will negatively affect the processing of the higher I/O processing priority computer.
[0009] Also, as the percentage of cache memory used in the storage control apparatus as a whole increases, competition for securing cache memory resources develops. For example, relatively low processing priority I/O such as that performed in the background will negatively affect high processing priority I/O such as that executed online.
[0010] It is an object of the present invention to provide a storage control apparatus for processing I/O issued by a plurality of computers over a plurality of paths to a plurality of storage devices, wherein relatively low processing priority I/O does not affect high processing priority I/O and the processing performance of the storage control apparatus as a whole is sustained.
[0011] In order to achieve the above-mentioned object, shared processor memory established within the storage control apparatus is provided with priority channel port information for each channel port unit, defines target I/OPS (I/O per second) information for channel ports set as “priority,” and performs feedback control of I/O processes for channel ports that are not set as “priority” so that the target number of I/O processes for “priority” ports can reach the target I/OPS.
[0012] Also, the shared processor memory is provided with priority host information for each computer, defines the target I/OPS information for the computers set as “priority,” and performs feedback control of I/O processes for computers that are not set as “priority” so that the target number of I/O processes for “priority” computers can reach the target I/OPS.
[0013] Likewise, the shared processor memory is provided with priority device information for each device, defines the target I/OPS information for the devices set as “priority,” and performs feedback control of I/O processes for devices that are not set as “priority” so that the target number of I/O processes for “priority” devices reaches the target I/OPS.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a drawing showing a schematic of a computer system for performing I/O processing with a plurality of devices under the control of a storage control apparatus having a service processor and a plurality of processors that can communicate therewith;
[0015] FIG. 2 is a drawing showing a schematic of a computer system wherein a plurality of computers are connected on a single channel port and perform I/O processing with a plurality of storage devices under the control of a storage control apparatus;
[0016] FIG. 3 is a drawing showing a schematic of a computer system wherein a single computer performs I/O processing with a plurality of storage devices under the control of a storage control apparatus;
[0017] FIG. 4 is a table for managing and controlling the priority/non-priority settings of channel ports in the shared memory in the storage control apparatus;
[0018] FIG. 5 is a table for managing and controlling the priority/non-priority settings of hosts in the shared memory in the storage control apparatus;
[0019] FIG. 6 is a table for managing and controlling the priority/non-priority settings of storage devices in the shared memory in the storage control apparatus;
[0020] FIG. 7 is a flowchart showing the process for determining whether a channel port is priority/non-priority and checking whether a command can be started;
[0021] FIG. 8 is a flowchart showing the process for determining whether a host is priority/non-priority and checking whether a command can be started;
[0022] FIG. 9 is a flowchart showing the process for determining whether a storage device is priority/non-priority and checking whether a command can be started;
[0023] FIG. 10 is a flowchart showing the process for determining whether channel ports, hosts, and storage devices are priority/non-priority and checking whether a command can be started;
[0024] FIG. 11 is a flowchart showing the process for setting the channel port information to priority/non-priority from the service processor and, based on this information, adjusting the delay for I/O of channel ports set as “non-priority” based on the target value for channel ports set as “priority,” so as to minimize the influence on I/O processing of channel ports set as “priority”; and
[0025] FIG. 12 is a flowchart showing the process for setting the channel port information to priority/non-priority from the service processor and, based on this information, adjusting the delay for I/O of channel ports set as “non-priority” based on the maximum value for channel ports set as “non-priority,” so as to minimize the influence on I/O processing of channel ports set as “priority”.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The present invention is explained below with reference to the drawings.
[0027] FIG. 1 is a drawing showing an embodiment of a computer system relating to the present invention. In the computer system in FIG. 1 , the storage control apparatus 301 is connected to computers 101 through 104 through channel paths 201 through 204 and controls I/O processes requested for a plurality of storage devices 601 , 602 , 603 , 604 . The storage control apparatus 301 comprises channel ports 401 through 404 , I/O process controllers (processors) 501 through 504 , individual memory 506 through 509 provided for each controller, shared memory 505 which can be accessed from the I/O process controllers (processes) 501 through 504 , and cache memory 510 . The I/O process controllers 501 through 504 perform data input and output for the plurality of storage devices 601 individually. The shared memory 505 contains a channel port information management table 511 , a host information management table 521 , and a storage device information management table 531 for determining the priority of I/O processes when executing I/O process requests from the computers 101 through 104 . At the start of every I/O process, it is determined whether the I/O process can be started based on these tables. The I/O operations are controlled as follows. With the channel port information management table 511 , it is checked whether the I/O-object channel path for the process to be started is “priority”. If it is priority, the process continues without further changes; and if not priority, the I/O process is executed while I/O on that channel is suppressed to certain extent. Likewise, with the host information management table 521 , it is checked whether the I/O-object computer for the process to be started is “priority”. With the storage device information management table 531 , it is checked whether the I/O-object storage device for the process to be started is “priority”.
[0028] FIG. 2 shows a constitution wherein the computers 101 through 104 are all connected to the channel port 401 in the storage control apparatus 301 . In this case, because the I/O is concentrated in a single channel port, the priority computers are defined with the settings in the host information management table 521 , without any effect from the information in the cannel port information management table 511 , when it is desired to provide levels of priority among the computers 101 through 104 . The influence of other computers on I/O processing can be suppressed. In the case where the settings in the host information management table 521 are not by computer but by World Wide Name, the priority level can be provided to the path of the World Wide Name.
[0029] FIG. 3 shows a constitution wherein only a computer 101 is connected to a channel port 401 in the storage control apparatus 301 . In this case, the I/O is on only one cannel port and there are no other computers to affect the I/O. The priority storage devices are defined with the settings in the storage device information management table 531 and the influence of I/O processing of other storage devices can be suppressed, without any effect from the information in the channel port information management table 511 and the host information management table 521 , when it is desired to provide levels of priority among the storage devices 601 through 604 .
[0030] FIG. 4 is a drawing of the channel port information management table 511 stored in the common memory 505 . The channel port information management table 511 manages information for each channel port. The information is divided into priority channel port information 512 and non-priority channel port information 516 . The priority channel port information 512 comprises the following: priority channel port identification information Pc 513 for identifying whether a channel port is a priority channel port; IOPS threshold information It 514 for determining whether a non-priority channel port suppresses I/O processing; IOPS performance information Ie 515 for indicating the actual performance status of the channel port; and target IOPS information Io 519 for setting the I/O process performance that is the goal, when setting a channel port as a priority channel port. Specifically, the IOPS threshold information It 514 is compared with the IOPS performance information Ie 515 calculated from the number of current IO. When the IOPS performance information Ie 515 exceeds the IOPS threshold information It 514 , I/O processing will be suppressed for a channel port that is not set as “priority”.
[0031] Also, the non-priority channel port information 516 comprises the following: a delay setting value dt 517 for suppressing I/O processes in the case where the channel port is a non-priority channel port; a delay timer Dt 518 ; IOPS maximum number Iu 51 A for setting the maximum number of I/O processes; IOPS minimum number IL 51 B for setting the minimum number when suppressing I/O processes; and IOPS performance information Ie 51 C. Specifically, when the above-mentioned IOPS performance information Ie 514 exceeds the IOPS threshold information It 514 , the non-priority channel port information is used to delay the start of I/O processes received from a non-priority channel port by the delay setting value dt 517 put I/O processes on standby. The timer Dt 518 is a region for counting up the time of the delay setting value dt 517 ; the value is initialized and the count by the timer starts upon reception of the delay setting value from a non-priority channel port.
[0032] FIG. 5 is a drawing of the host information management table 521 stored in the common memory 505 . The host information management table 521 manages information for each host. This information is divided into priority host information 522 and non-priority host information 526 . The priority host information 522 comprises the following: priority host identification information Ph 523 for identifying whether a host is a priority host; IOPS threshold information It 524 for determining whether a non-priority host suppresses I/O processing; IOPS performance information Ie 525 for indicating the actual performance status of the host; and target IOPS information lo 529 for setting the I/O process performance that is the goal, when setting a host as a priority host. Also, the non-priority host information 526 comprises the following: a delay setting value dt 527 for suppressing I/O processes in the case where the host is a non-priority host; a delay timer Dt 528 ; IOPS maximum number Iu 52 A for setting the maximum number of I/O processes; IOPS minimum number IL 52 B for setting the minimum number when suppressing I/O processes; and IOPS performance information Ie 52 C.
[0033] FIG. 6 is a drawing of the storage device information management table 531 stored in the common memory 505 . The storage device information management table 531 manages information for each storage device. This information is divided into priority storage device information 532 and non-priority storage device information 536 . The priority storage device information 532 comprises the following: priority storage device identification information Pd 533 for identifying whether a storage device is a priority storage device; IOPS threshold information It 534 for determining whether a non-priority storage device suppresses I/O processing; IOPS performance information Ie 535 for indicating the actual performance status of the storage device; and target IOPS information lo 539 for setting the I/O process performance that is the goal, when setting a storage device as a priority storage device. Also, the non-priority storage device information 536 comprises the following: a delay setting value dt 537 for suppressing I/O processes in the case where the storage device is a non-priority storage device; a delay timer Dt 538 ; IOPS maximum number Iu 53 A for setting the maximum number of I/O processes; IOPS minimum number IL 53 B for setting the minimum number when suppressing I/O processes; and IOPS performance information Ie 53 C.
[0034] FIG. 7 is a drawing showing the flow for checking whether it is possible to start a command in an I/O process with the channel port as the parameter. In the flow in FIG. 7 , the priority channel port identification information Pc is fetched 801 . If the channel port is a priority channel port, the process ends with the command process OK 802 . If the channel port is not a priority channel port, it is checked whether a priority channel port is present among other ports. If a priority channel port is not present, the process ends with the command process OK 803 . If a priority channel port is present among other ports, the IOPS threshold information It and IOPS performance information Ie for the priority channel port are fetched 804 , 805 ; and the process ends with the command process OK if there is no port where It<Ie among the other channel ports 806 . When there is a port with It<Ie, the delay setting value dt and delay timer Dt of the channel port are fetched 807 , 808 . While Dt is updated until dt<Dt 811 , the command process is made NG 813 . When dt becomes less than Dt 809 , Dt is initialized 810 and the command process in made OK 812 . In this way, a non-priority channel port is prevented from influencing the I/O of a priority channel port by suppressing its own I/O.
[0035] FIG. 8 is a drawing showing the flow for checking whether it is possible to start a command in an I/O process with the host as the parameter. In the flow in FIG. 8 , the priority host identification information Ph is fetched 901 . If the host is a priority host, the process ends with the command process OK 902 . If the host is not a priority host, it is checked whether a priority host is present among other hosts. If a priority host is not present, the process ends with the command process OK 903 . If a priority host is present among other hosts, the IOPS threshold information It and IOPS performance information Ie for the priority host are fetched 904 , 905 ; and the process ends with the command process OK if there is no host where It<Ie among the other hosts 906 . When there is a host with It<Ie, the delay setting value dt and delay timer Dt of the host are fetched 907 , 908 . While Dt is updated until dt<Dt 911 , the command process is made NG 913 . When dt becomes less than Dt 909 , Dt is initialized 910 and the command process is made OK 912 . In this way, a non-priority host is prevented from influencing the I/O of a priority host by suppressing its own I/O.
[0036] Likewise, FIG. 9 is a drawing showing the flow for checking whether it is possible to start a command in an I/O process with the storage device as the parameter. In the flow in FIG. 9 , the priority storage device identification information Pd is fetched 1001 . If the storage device is a priority storage device, the process ends with the can mind process OK 1002 . If the storage device is not a priority storage device, it is checked whether a priority storage device is present among other storage devices. If a priority storage device is not present, the process ends with the command process OK 1003 . If a priority storage device is present among other storage devices, the IOPS threshold information It and IOPS performance information Ie for the priority storage device are fetched 1004 , 1005 ; and the process ends with the command process OK if there is no storage device where It<Ie among the other storage device 1006 . When there is a storage device with It<Ie, the delay setting value dt and delay timer Dt of the storage device are fetched 1007 , 1008 . While Dt is updated until dt<Dt 1011 , the command process is made NG 1013 . When dt becomes less than Dt 1009 , Dt is initialized 1010 and the command process is made OK 1012 . In this way, a non-priority storage device is prevented from influencing the I/O of a priority storage device by suppressing its own I/O. Furthermore, as in FIGS. 4 and 9 , other control methods divide areas within the storage devices into priority areas and non-priority areas and suppress the I/O processing for non-priority areas so as not to influence the I/O processing of areas set as “priority” within the same storage device.
[0037] FIG. 10 shows an example combining the command start check by channel port 814 , the command start check by host 914 , and the command start check by storage device 1014 . In the example in FIG. 10 , in the case where the channel port, host, and storage device are all set as “priority,” I/O processing is not suppressed except in the case where all parameters in the I/O processing satisfy “priority”. Other I/O processes are delayed in order to prevent effects on the above-mentioned I/O pressing. Also, in the command process 1104 , except for read or write processes according to the command, it is sometimes the case that the next I/O process is assumed and a pre-read process for other than the object reword is performed. For this type of process as well, however, the pre-read process will be suppressed unless the channel port, host, and storage device are all set as “priority”.
[0038] FIG. 11 is a drawing showing a flowchart wherein the IOPS of the priority channel port is controlled to approach most closely to the target IOPS by setting information from the service processor 701 connected with the storage control apparatus and adjusting the delay of the I/O process of the non-priority channel port. The following information is set from the service processor 701 : priority channel port identification information 513 , IOPS threshold information 514 , target IOPS information 519 , and IOPS maximum number 51 A and IOPS minimum number 51 B of the non-priority channel port. The value of the IOPS maximum number 51 A is set to an estimated value conforming to the actual environment because the extent of the influence on the I/O processing of the priority channel port is not known precisely. In the I/O process control portion, the set IOPS maximum number is fetched 1111 , the I/O process delay setting value dt 517 is calculated from the IOPS maximum number 1112 , and the I/O process is carried out for a standard time based on this value 1113 . After that, IOPS performance information Ie 515 and target IOPS information Io 519 of the priority channel port, and the IOPS minimum number IL 51 B of the non-priority channel port are fetched 1114 , 1115 . If there is no difference between Ie and lo (or when that difference is judged to be small enough to be ignored), the I/O processing capacity of the priority channel port is determined to have reached the target. The delay setting value dt 517 is not changed and the I/O process continues. Even if the I/O processing of the priority channel port could not reach the target, adjustment is judged to be impossible even in the case where the I/OPS of the port is no longer within the range of Iu and IL, the delay setting value dt 517 is not changed and the I/O process continues. In other cases, the delay setting value dt is reset based on the formula in the drawing and the process returns to step 1113 . The optimum delay setting value dt can be found by repeating these steps.
[0039] Information for priority/non-priority hosts and for priority/non-priority storage devices can be set in the same way as information for priority/non-priority channel ports.
[0040] FIG. 12 is a drawing showing a flowchart wherein the I/OPS of a priority channel port is made to approach most closely to the target I/OPS by adjusting the delay of the I/O processing of non-priority channel ports based on information set from the service processor 701 connected to the storage control apparatus, controlling the I/OPS of non-priority channel ports to approach the IOPS maximum number for non-priority channel ports; and controlling the I/O processing of non-priority channel ports. The following information is set from the service processor 701 : priority cannel port identification information 513 , IOPS threshold information 514 , and the IOPS maximum number Iu 51 A of the non-priority channel port. The value of the IOPS maximum number Iu 51 A is set to an estimated value conforming to the actual environment because the extent of the influence on the I/O processing of the priority channel port is not known precisely. In the I/O process control portion, the set IOPS maximum number is fetched 1121 , the I/O process delay setting value dt 517 is calculated from the IOPS maximum number 1122 , and the I/O process is carried out for a standard time based on this value 1123 . After that, IOPS performance information Ie 51 C of the priority channel port is fetched 1124 . If there is no difference between Ie and Iu (or when that difference is judged to be small enough to be ignored), the I/O processing capacity of the priority channel port is determined to have reached the target. The delay setting value dt 517 is not changed and the I/O process continues.
[0041] In other cases, the delay setting value dt is reset based on the formula in the drawing 1126 and the process returns to step 1123 . The optimum delay setting value dt can be found by repeating these steps. As a result, if the I/OPS of the priority channel port does not reach the value that is the goal, the optimum I/O process state is arrived at by repeatedly resetting the value of the I/OPS maximum number Iu 51 A from the service processor 701 . Information for priority/non-priority hosts and for priority/non-priority storage devices can be set in the same way as information for priority/non-priority channel ports.
[0042] With the above-mentioned system, it is possible to maximize the processing capacity of I/O to be performed at a high priority by carrying out the processing while restricting I/O for which priority levels can be dropped.
[0043] The present invention has the following effects as a system for sustaining the processing capacity of I/O to be performed at a high priority by processing while restricting I/O for which priority levels can be dropped:
(1) In the case of performing I/O processing with a plurality of channel ports, the channel port for which sustained capacity is desired is set as a priority channel port. Accordingly, it is possible for the channel ports set as a priority channel port to maintain a constant capacity even if I/O processing enters an overloaded state for the storage control apparatus as a whole. (2) In the case of a plurality of hosts concentrated at a single channel port, the host for which sustained capacity is desired is set as a priority host. Accordingly, it is possible for the host set as a priority host to maintain a constant capacity even if I/O processing enters an overloaded state for the storage control apparatus as a whole. (3) In the case where one host performs I/O processing for a plurality of storage devices, the storage device, for which priority is desired is set as a priority storage device. Accordingly, it is possible for I/O processing to the storage device set as a priority storage device to maintain a constant rapacity, even if I/O processing enters an overloaded state for the storage control apparatus as a whole. (4) By combining (1) through (3) above, it becomes possible to specify priority I/O processing conditions, such as sustaining the capacity of only I/O issued on a specific channel path from a specific host to a specific storage devices, and to construct a more finely controlled I/O processing environment.
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In response to requests for I/O processing sent from a computer, I/O which should be processed at a priority is enabled to be processed without being affected by other processing, by classifying I/O into those to be processed at a priority and those not to be processed at a priority. The storage control apparatus comprises an I/O processing controller with a memory that is common for the whole controller. The storage control apparatus manages information for dividing and controlling a plurality of I/O processes as priority and non-priority in that memory and operates while suppressing non-priority I/O processing on the basis of information in the memory.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 09/728946 entitled “Motorhome With Increased Interior Height” filed Dec. 1, 2000 and claims the benefit of U.S. Provisional Application No. (unknown, attorney docket ALFALE.045PR) filed Sep. 7, 2001 entitled “Motorhome HVAC System”.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to the field of vehicle heating, venting, and air conditioning (HVAC) systems and, in particular, to an HVAC system adapted for motorhomes in which the HVAC system is substantially positioned outside the living portion of the motorhome and employs a common air return system.
[0004] 2. Description of the Related Art
[0005] Motorhomes have become an increasingly popular and common means of recreation. Motorhomes are self-propelled vehicles that include a living space inside. Motorhomes typically provide sleeping areas, cooking facilities, and self-contained water supplies and toilet facilities. More elaborate motorhomes can include refrigerator/freezer units, showers and/or bathtubs, air conditioning, heaters, built in generators and/or power inverters, televisions, VCRs, and clothes washers and dryers. Motorhomes provide many of the amenities of a residential home while on the road away from home and are popular for this reason. Motorhome users will typically use the motorhome to travel to a recreational area and live in the motorhome for some period of time. It is not unusual for people, particularly retired persons, to use a motorhome as their primary residence. Motorhome users often have families with children and, as their trips are often of a recreational nature, will often invite friends or family along on the trip.
[0006] It can be understood that since a motorhome will often be used by a large number of people and often for an extended period of time, the motorhome manufacturers and customers will seek as many amenities and as much interior living space as possible. A major goal of motorhome manufacturers and their customers is to maximize the amount of usable living space inside their motorhomes. However, the overall size of an motorhome is limited both by vehicle code regulations and by practical limitations on what is reasonable to drive and maneuver. Vehicle codes restrict the maximum height, width, and length of vehicles that may be driven on public roads. Also, as a vehicle increases in size, it becomes increasingly difficult to drive and can become physically too large to pass through locations that the driver may wish to go. In addition, as the motorhome gets physically larger, more fuel is required to move it, which increases the cost of operation.
[0007] An additional design constraint on the construction and design of motorhomes is their overall weight. Since an motorhome is intended to be mobile, an integral power plant is provided and the engine and drive-train have an upper design limit on the weight each is capable of moving. In addition, the chassis, suspension, wheels, and brakes of a motorhome also have upper design limits as to how much weight they can safely accommodate. These weight limits are established after careful engineering analysis and the weight ratings are endorsed and enforced by responsible governmental agencies. Exceeding the established weight limits of a power-train or chassis component can lead to excessive wear and failure, unacceptable performance, and exposure to liability in case of an accident. It is also highly desirable that as much payload as possible is available to accommodate passengers and cargo, i.e. available weight load between the wet weight of the motorhome and the total maximum gross weight of the motorhome.
[0008] A particular issue with the weight of a motorhome is its distribution along a vertical axis. The distance of a vehicle's center of mass from the road surface has a dramatic effect on the handling characteristics of the vehicle. The closer the center of mass is to the road surface, the shorter the moment arm between the center of mass and the roll axis of the vehicle. The shorter the moment arm between the center of mass and the roll axis of the vehicle, the less tendency the vehicle will have to lean in turns. Leaning in turns is uncomfortable for the occupants and typically places uneven loads on the tires and suspensions, compromising turning ability. Motorhomes, typically being quite tall, often exhibit significant leaning in turns. To minimize this leaning, within the height available in a motorhome, the weight should be concentrated as low as possible. For this reason, heavy items, such as generators, storage and holding tanks for water and fuel, and the engine are optimally placed low in the chassis.
[0009] Since motorhomes are mobile structures, they are typically exposed to the stresses of driving over roads that are in places quite rough. In addition, an motorhome will often have to travel over some distance of dirt surface to reach a camping space. Since an motorhome is typically used outdoors, it is exposed to the stresses of inclement weather and high winds. It can be appreciated that structural integrity is highly desired in an motorhome. However, the weight and size limitations previously mentioned place a limit on the strength of an motorhome. Accordingly, motorhomes are constructed to be as strong, but as light as possible.
[0010] The chassis of a motorhome is typically constructed on a steel ladder frame chassis. The chassis is a partially complete vehicle and is generally procured from a manufacturer such as Freightliner or Ford Motor Company. The chassis typically consists of two parallel frame rails extending the length of the chassis and interconnected with several perpendicular cross-braces to form a ladder frame. An engine, transmission, and fuel tank(s) are generally placed between the frame rails near one end. Suspension, steering, brake, and road wheel assemblies are attached outboard of the frame rails.
[0011] The coach bodywork, which provides and encloses the living space of the motorhome, is typically made from a laminate that can include light gauge sheet metal, plywood, vinyl, and insulation. The laminate is built to be strong, lightweight, weather resistant, and durable. The coach bodywork may also include a supporting framework. The floor of the coach typically rests indirectly on the chassis frame and the vertical walls extend upwards from the floor. The roof of the coach rests on and depends on the vertical walls of the body for structural support.
[0012] A completed motorhome may be up to 45′ long and 13′ 6″ high in most states. The chassis is generally on the order of 1′ high and is elevated some distance above the ground by the suspension and wheels to provide ground clearance for suspension movement and clearing obstacles in the road. The interior flooring in current art motorhomes is typically elevated a significant amount above the upper face of the chassis in order to facilitate installing ancillary equipment. In addition, many prior art motorhomes route cooling or heating air ducts adjacent the roof structure or mount air-conditioning units on the roof. Under the overall height limit previously mentioned, these structures in or on the roof intrude into the available interior height envelope and limit the usable interior vertical space.
[0013] It is sometimes the practice in the art to place major components of an HVAC system, particularly air-conditioning (A/C) condensers and compressors, on the roof of the motorhome. Placement of these A/C components on the roof does not take up limited and valuable interior space inside the coach. Placement of these A/C components on the roof also exposes the condenser to fresh air which increases the efficiency of the heat transfer performed by the A/C system.
[0014] Placement of A/C systems and/or associated ducting in the roof does however create a difficulty with water condensation. As air conditioning units cool air to a temperature below the ambient temperature, it is understood that in many conditions the temperature of the air conditioning unit and ducting carrying the cooled air will be below the ambient dew point and thus liquid water will condense on the cool surfaces. If these cool surfaces are located above living areas of the motorhome, as is the case with many current designs, the liquid water can be readily drawn by gravity into the interior of the motorhome. It will be appreciated that liquid water intruding into the interior of the motorhome is an annoyance at best and can damage the structural integrity of interior structures as well as staining or warping interior finishings. Liquid water can also irreparably damage electronic equipment, such as laptop computers, televisions, and VCRs, such as would often be located in the interior of a motorhome. Therefore the condensed water is typically routed to run off the exterior surface of the RV. However this external draining tends to leave unsightly stains and can drip on persons underneath.
[0015] In an A/C system the evaporator is that portion of the system that absorbs heat from the ambient air thereby cooling the air and providing the air-conditioning effect. The evaporator portion of A/C system is thus preferably placed in proximity to the space to be air conditioned and the condenser and compressor portions can be readily placed elsewhere and joined to the evaporator by fluid lines. A heater or furnace in contrast does not typically comprise separate components that can be readily separated. Thus, the heater or furnace portion of a typical HVAC system is a unitized assembly, separate from the A/C system that is preferably also placed in the space to be heated, i.e. the interior of the motorhome coach. Disadvantageously, the combustion of fuels such as propane to heat air and the operation of fans to drive heated air into the interior of the coach tends to be noisy. Thus, placement of the furnace inside the coach, while better for heating efficiency, creates an annoyance for the occupants due to the noise of operation.
[0016] A further drawback to conventional HVAC systems known for motorhomes is that they have separate A/C and heating units with separate air ducting and filtering systems. Air is routed through the air conditioning unit through ducting and filtering members that are completely separate from the heating unit's ducting and filtering members. This ducting duplication results in additional separate heating and air-conditioning air filters that require periodic changing as well as additional interior space consumed by the ducting. As previously mentioned, interior space within the coach is highly valuable and preferably maximized for the occupants comfort and utility.
[0017] From the foregoing, it can be appreciated that there is a continuing need for a stronger motorhome coach construction that also provides increased interior living space. The structure should minimize weight to the motorhome and should also maintain as low a center of gravity as possible to benefit vehicle handling characteristics. There is also a need for a HVAC system that positions noisy components outside the interior of the coach and minimizes redundancies in ducting and filters to reduce costs and increase interior space and serviceability. The HVAC system preferably position the A/C condenser and ducting in such a way that water that condenses out during use does not intrude into the interior of the motorhome.
SUMMARY OF THE INVENTION
[0018] The aforementioned needs are satisfied by the present invention, which in one aspect is a
[0019] As stated, the heating component is positioned outside of the interior of the motorhome. It is understood that the heating component will make noise during operation, and that noise could potentially annoy occupants of the motorhome. By positioning the heating component on the outside of the motorhome, sound must travel through the coach body in order to reach the interior of the motorhome and any occupants therein. However, the coach body will have natural sound dampening characteristics, and additional sound insulation might be included inside the walls of the coach body, both of which will substantially dampen noise generated by the heating component. Therefore, positioning the heating component as such will significantly reduce the amount of heating component noise reaching the interior of the motorhome. These and other objects and advantages of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a perspective view of a preassembled vehicle frame mounted on a preassembled chassis forming the framework for a motorhome with a high interior ceiling including an HVAC system with common air return;
[0021] [0021]FIG. 2 is a perspective view of an assembled heating, ventilation, and air-conditioning (HVAC) system; and
[0022] [0022]FIG. 3 is a side, section schematic view of a motorhome provided with the HVAC system of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Reference will now be made to the drawings wherein like numerals refer to like parts throughout. FIG. 1 shows an preassembled vehicle frame 100 mounted to a preassembled chassis 102 . The vehicle frame 100 , mounted to the chassis 102 in the manner that will be described in greater detail below, facilitates the construction of a motorhome 104 (FIG. 3) with a greater interior ceiling height, which in this embodiment, is at least 7′-6″ in a reduced time span. The vehicle frame 100 also facilitates mounting of relatively massive items, such as generators, furnaces, storage and holding tanks, and the like low to the ground so as to provide a lower center of mass for the motorhome 104 .
[0024] The vehicle frame 100 provides a strong three dimensional space frame 118 to inhibit twisting of the vehicle frame 100 under torsional forces such as would arise when the motorhome 104 drives over uneven terrain so as to lift or drop a wheel 116 with respect to the other wheels 116 . The vehicle frame 100 further defines integral storage areas 106 as part of the structure of the vehicle frame 100 in a manner that will be described in greater detail below. As shown in FIG. 1, the storage areas 106 are positioned below the beltline of the frame 100 and chassis 102 . Placement of the storage areas 106 low within the motorhome 104 also positions items that may be stored in the storage areas 106 low within the motorhome 104 . This aspect of the invention advantageously positions heavy cargo that users may place in the motorhome 104 low along the vertical extent of the motorhome 104 thereby maintaining an advantageously low center of mass.
[0025] The vehicle frame 100 further facilitates routing of a heating, ventilation, and air conditioning (HVAC) system 110 below the beltline of the frame 100 so as to avoid intrusion of the HVAC system 110 into the interior living space of the motorhome 104 to further enable increased interior ceiling height of the motorhome 104 employing the vehicle frame 100 . The HVAC system 110 comprises a furnace 164 and air conditioning unit 162 including evaporator, condenser, and compressor. These relatively heavy portions of the HVAC system 110 are installed below the beltline of the frame 100 thereby maintaining a lower c.g. than other designs.
[0026] The chassis 102 also comprises a plurality of road wheels 116 with corresponding suspension, brake systems, steering, and drive mechanisms of types known in the art that are positioned at substantially the front and rear corners of the chassis 102 in the manner illustrated in FIG. 1. The road wheels 116 enable the motorhome 104 to roll along the road and to be steered and braked in a well understood manner. The road wheels 116 are positioned adjacent the overlapping raised rails 112 and lower rails 114 . The chassis 102 further comprises an engine assembly, transmission, drive axle, fuel system, and electrical system (not illustrated) of types known in the art to provide the motive power for the motorhome 104 . These items are advantageously located substantially within the plane of the rails 112 to lower the center of mass of the chassis 102 and thus the motorhome 104 .
[0027] The chassis 102 of this embodiment is highly resistant to bending along longitudinal and transverse axes. However, the chassis 102 , by itself, is susceptible to twisting along the plane of the longitudinal and transverse axes due to torsional forces. Such torsional force may arise when a road wheel(s) 116 at one corner of the chassis 102 is displaced either above or below the plane of the remaining road wheels 116 . Additionally, the torque of the engine exerts a torsional force on the chassis 102 .
[0028] The motorhome 104 of this embodiment is assembled on and around the interconnected vehicle frame 100 and the chassis 102 . The motorhome 104 provides users with a vehicle having a variety of living spaces and amenities fitted within the motorhome 104 . It is expected that the partitioning of the interior living spaces and placement of interior amenities will vary depending on the needs of any particular application or customer.
[0029] The motorhome 104 also comprises a front loop 192 as shown in FIG. 1. The loop 192 is a generally rectangular structure attached at the front of the motorhome 104 to the frame 100 . The loop 192 provides structural support for interior body assemblies in the driver's and front passenger's area as well as the front exterior bodywork of the motorhome 104 and the front windshield. The loop 192 is assembled from a plurality of elongate steel members via welding in a similar manner to that previously described with respect to the frame 100 .
[0030] The vehicle frame 100 also comprises seat supports 126 . The seat supports 126 are, in one embodiment, rectangular structures formed from sheet steel approximately ⅛″ thick and are approximately 12{fraction (13/16)}″ by 22½″. The seat supports 126 are fixedly attached to the vehicle frame 100 via a plurality of bolts and/or welding in a known manner adjacent the front end of the vehicle frame 100 . The seat supports 126 provide a support and attachment structure for passenger seats 128 of known types. The passenger seats 128 provide seating accommodations for driver and passengers in a known manner.
[0031] The HVAC system 110 in this embodiment comprises the air conditioning unit 162 , the furnace 164 , a manifold 166 , a duct 170 , at least one register 172 , an intake 171 , and a filter 173 as illustrated in FIG. 1. The intake 171 (shown in section view in FIGS. 1 and 3) commonly directs air from the interior of the motorhome 104 to the air conditioning unit 162 and the furnace 164 . The filter 173 is positioned within the intake 171 and filters the air entering the HVAC system 110 . The air conditioning unit 162 receives air from the interior of the motorhome 104 via the intake and cools this filtered incoming air and directs the cool air into the interior of the motorhome 104 via the manifold 166 , duct 170 and register(s) 172 . The furnace 164 warms incoming air and directs the warm air into the interior of the motorhome 104 also via the manifold 166 , duct 170 and register(s) 172 . The air-conditioning unit 162 , furnace 164 , and filter 173 are commercially available and the selection of an appropriate model of air-conditioning unit 162 , furnace 164 , and filter 173 is expected to vary depending on the size of and amount of insulation provided for a particular embodiment of motorhome 104 .
[0032] The manifold 166 receives air from both the air conditioning unit 162 and the furnace 164 and routes the air to the duct 170 . The duct 170 extends substantially the length of the interior of the motorhome 104 as shown in FIGS. 1 and 3. The duct 170 carries the warm or cool air to at least one register 172 . The registers 172 direct cool or warm air, received from the duct 170 , into the interior of the motorhome 104 . The registers 172 includes a screen to inhibit objects falling into the interior of the registers 172 and the duct 170 .
[0033] The common intake 171 is advantageously formed on two sides by interior paneling that serves both to direct the air inside the intake 171 and also provide interior trim in the interior of the motorhome 104 . The other two sides of the intake 171 are formed by interior surfaces of the coach in a corner of the motorhome 104 . Thus, the intake 171 is substantially defined by body structure of the motorhome 104 that simultaneously serves other structural or esthetic functions thereby reducing material redundancy and effecting weight and materiel savings for the motorhome 104 . In addition, by directing air to both the air-conditioning unit 162 and the furnace 164 , the common intake 171 of this embodiment, obviates the need for the separate air intakes for the A/C unit and the furnace of other known designs.
[0034] The common intake 171 of this embodiment also facilitates the use of a single filter 173 for the HVAC system 110 . This single filter 173 reduces the time and expense of maintaining the HVAC system 110 by the end user as compared to other designs with multiple filters for the separate A/C and furnace systems. This commonality also reduces the time and expense of construction of the HVAC system 110 as well as reducing the weight thereof. In certain embodiments, the filter 173 can comprise a plurality of filter elements or stages, for example, a first filter element/stage adapted to remove larger air borne particles and a second filter element/stage adapted to remove smaller airborne particles that may pass through the first element/stage.
[0035] The HVAC system 110 , of this embodiment, is located within or below the plane of the chassis 102 . Positioning the air conditioning unit 162 and the furnace 164 , which are both relatively heavy items, within or below the plane of the chassis 102 further lowers the center of mass of the motorhome 104 to thereby improve the road handling of the motorhome 104 . The placement of the HVAC system 110 of this embodiment also distances the duct 170 and registers 172 from the coach roof 140 . Other known motorhome designs rout HVAC ducting adjacent the roof of the vehicle which exposes the cool air to thermal heating from sunlight incident on the roof of the vehicle. In the motorhome 104 of this embodiment, the duct 170 , register 172 , and air conditioning unit 162 are shaded from incident sunlight by the motorhome 104 . Thus, the HVAC system 110 can more efficiently provide cool air to the interior of the motorhome 104 . This improves the occupant's comfort in hot weather and reduces fuel costs for powering the HVAC system 110 .
[0036] A further advantage of the HVAC system 110 of this embodiment is that the air conditioning unit 162 , duct 170 , and register 172 which carry cool air are located below the living space of the motorhome 104 . As is well understood by those of ordinary skill in the art, a cooler than ambient surface, such as the air conditioning unit 162 , duct 170 , and register 172 induces liquid water to condense out of the atmosphere if the temperature of the surface is at or below the dew point. When air conditioning ducting is routed above the living space of a motorhome, liquid water that condenses on the ducting is drawn downwards by gravity. This can induce liquid water to intrude into walls, ceilings, and other interior materials. It can be appreciated that liquid water can readily damage the structural integrity of typical motorhome building materials. Liquid water can also stain and warp interior materials, damaging the aesthetics of a motorhome. The air conditioning unit 162 , duct 170 , and registers 172 of this embodiment are positioned below the living space of the motorhome 104 and thus water that condenses out during use of the HVAC system 110 is drawn downwards and away from the motorhome 104 without intruding into the living spaces of the motorhome 104 .
[0037] An additional advantage of the HVAC system 110 of this embodiment is that placement of the HVAC system 110 adjacent and below the beltline of the chassis 102 obviates the need to place portions of an HVAC system on the roof of the motorhome 104 . Other known HVAC systems place portions of the system on the exterior roof of a motorhome. This requires that the major plane of the outer roof be lowered with respect to the roof of the present invention so as to maintain the overall height restrictions previously mentioned. Lowering the exterior roof height results in corresponding lowering of the interior ceiling height and a corresponding reduction in the interior space and livability of such a motorhome.
[0038] Yet another advantage of the HVAC system 110 of this embodiment is that placement of the HVAC system 110 adjacent and below the beltline of the chassis 102 distances the furnace 164 and air conditioning unit 162 from the interior of the motorhome 104 . The air conditioning unit 162 and furnace 164 are relatively noisy in operation. Placing the HVAC system 110 outside the interior of the motorhome 104 distances the noise sources of the air conditioning unit 162 and the furnace 164 and thus provides a quieter, more comfortable living environment for users of the motorhome 104 .
[0039] Although the preferred embodiments of the present invention have shown, described and pointed out the fundamental novel features of the invention as applied to those embodiments, it will be understood that various omissions, substitutions and changes in the form of the detail of the device illustrated may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the invention should not be limited to the foregoing description but is to be defined by the appended claims.
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A unitized heating, ventilation, and air conditioning (HVAC) system for ventilating and regulating the air temperature inside a motorhome. Air is drawn from inside the motorhome and is directed to a furnace and an air conditioning unit via a common air return. A filter is positioned within the common return. The HVAC unit is compact and adapted for placement below the living area of motorhome so as to reduce the noise inside the cabin generated by the HVAC system and to reduce the center of mass of the motorhome so equipped.
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CROSS REFERENCE TO RELATED APPLICATIONS
Reference is made to commonly assigned U.S. patent application Ser. No. 09/379,776, filed Aug. 24, 1999 entitled “Forming A Display Having Conductive Image Areas Over A Light Modulating Layer” by Dwight J. Petruchik et al., U.S. patent application Ser. No. 09/723,389, filed Nov. 28, 2000, entitled “Unipolar Drive for Cholesteric Liquid Crystal Displays” by David M. Johnson et al., U.S. patent application Ser. No. 09/915,831, filed Jul. 26, 2001, entitled “Method of Making Liquid Crystal Display Having a Dielectric Adhesive Layer for Laminating a Liquid Crystal Layer” by Smith et al and U.S. patent application Ser. No. 09/915,614, filed Jul. 26, 2001, entitled “Making a Liquid Crystal Display Using Heat and Pressure Lamination of Liquid Crystal Coating” by Smith et al, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to providing a dielectric layer for polymer dispersed liquid crystal displays.
BACKGROUND OF THE INVENTION
Currently, information is displayed using assembled sheets of paper carrying permanent inks or displayed on electronically modulated surfaces such as cathode ray displays or liquid crystal displays. Other sheet materials can carry magnetically writable areas to carry ticketing or financial information, however magnetically written data is not visible.
A structure is disclosed in PCT/WO 97/04398, entitled “Electronic Book With Multiple Display Pages” which is a thorough recitation of the art of thin, electronically written display technologies. Disclosed is the assembling of multiple display sheets that are bound into a “book”, each sheet is arranged to be individually addressed. The patent recites prior art in forming thin, electronically written pages, including flexible sheets, image modulating material formed from a bi-stable liquid crystal system, and thin metallic conductor lines on each page.
Fabrication of flexible, electronically written display sheets are disclosed in U.S. Pat. No. 4,435,047. A first sheet has transparent ITO conductive areas and a second sheet has electrically conductive inks printed on display areas. The sheets can be glass, but in practice have been formed of Mylar polyester. A dispersion of liquid crystal material in a binder is coated on the first sheet, and the second sheet is bonded to the liquid crystal material. Electrical potential applied to opposing conductive areas operate on the liquid crystal material to expose display areas. The display uses nematic liquid crystal material which ceases to present an image when de-energized.
U.S. Pat. No. 5,223,959 discloses a plurality of polymer dispersed liquid crystal material, each having a different dye material of red, green or blue dye material. Differing electrical signals to common electrodes operate on each of the materials to control the state of each type of dyed liquid crystal material. The patent requires the use of conventional nematic liquid crystals with a dye to absorb light. The droplets are chemically treated to be stable in either a clear or a light absorbing state. The invention also requires materials having different response times to electrical signals. The device must be continually driven so that the human eye perceives complementary colors. This arrangement has the disadvantage of requiring continuous, high speed electrical drive because the materials do not maintain their state. The material must be driven to achieve a neutral color density.
U.S. Pat. No. 5,437,811 discloses a light-modulating cell having a polymer dispersed chiral nematic liquid crystal. The chiral nematic liquid crystal has the property of being driven between a planar state reflecting a specific visible wavelength of light and a light scattering focal-conic state. Said structure has the capacity of maintaining one of the given states in the absence of an electric field.
U.S. Pat. No. 3,816,786 discloses droplets of cholesteric liquid crystal in a polymer matrix responsive to an electric field. The electrodes in the patent can be transparent or non-transparent and formed of various metals or graphite. It is disclosed that one electrode must be light absorbing and it is suggested that the light absorbing electrode be prepared from paints contains conductive material such as carbon.
U.S. Pat. No. 5,289,300 discusses forming a conductive layer over a liquid crystal coating to form a second conductor. The description of the preferred embodiment discloses Indium-Tin-Oxide (ITO) over a liquid crystal dispersion to create a transparent electrode.
Prior art discloses the use of dielectric barrier layers formed over ITO conductors. The dielectric layer protects the ITO transparent conductor from damage from electrochemical interaction with the light modulating material. The protective layers are typically formed by vacuum sputtering silicon dioxide over the ITO conductors. The vacuum forming process is slow and expensive.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a highly effective dielectric coating over electrodes used in polymer dispersed liquid crystal displays.
This object is achieved in a method of making a liquid crystal display, comprising the steps of:
(a) providing a substrate;
(b) providing a first electrode over the substrate;
(c) coating the first electrode with aqueous dispersed material which when dried provides a dielectric layer over the first electrode;
(d) coating the dielectric layer with liquid crystal bearing material and drying such liquid crystal bearing material; and
(e) providing a second electrode in contact with the dried liquid crystal bearing material.
The invention provides an inexpensive dielectric layer between field carrying electrodes in displays that are aqueous coated. Such dielectric layers provide a good bond between the aqueous suspension and the ITO on a flexible substrate.
The present invention provides a dielectric layer over a conductive layer using simple, inexpensive aqueous coatings. Such coatings permit the fabrication of electronic privacy screens having long life and durability. The aqueous dielectric coating significantly improves yields of cholesteric memory displays having electrical electrodes applied over a polymer dispersed liquid crystal layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a sheet having a coated liquid crystal in accordance with the present invention;
FIG. 2 is a plot of a distribution of domain size for aqueous dispersed liquid crystal;
FIG. 3A is a sectional view a sheet having a coated emulsion before drying;
FIG. 3B is a sectional view of a sheet having a coated emulsion after drying;
FIG. 4A is a sectional view of a nematic liquid crystal without an applied electric field;
FIG. 4B is a sectional view of a nematic liquid crystal with an applied electric field;
FIG. 5A is a display sheet having a laminated second electrode in accordance with prior art;
FIG. 5B is a display sheet having a laminated second electrode in accordance with a first embodiment of this invention;
FIG. 5C is a display sheet having a laminated second electrode in accordance with a second embodiment of this invention;
FIG. 5D is a display sheet having a laminated second electrode in accordance with a third embodiment of this invention;
FIG. 6A is a view of the optical characteristics of a chiral nematic material in a planar state reflecting light;
FIG. 6B is a view of the optical characteristics of a chiral nematic material in a focal-conic light diffusing state;
FIG. 7 is a plot of the response of a cholesteric to an electrical field of varying strength;
FIG. 8A is a display sheet having a coated second electrode in accordance with prior art; and
FIG. 8B is a display sheet having a coated second electrode in accordance with this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is an isometric partial view of a new structure for a medium shown as a sheet 10 made in accordance with the invention. It will be understood that other forms of media such as a more permanent display can also be used in accordance with the present invention. Sheet 10 includes a flexible substrate 15 , which is a thin transparent polymeric material, such as Kodak Estar film base formed of polyester plastic that has a thickness of between 20 and 200 microns. In an exemplary embodiment, substrate 15 can be a 125-micron thick sheet of polyester film base. Other polymers, such as transparent polycarbonate, can also be used.
First electrode 20 is formed over substrate 15 . First electrode 20 can be Tin-Oxide or Indium-Tin-Oxide (ITO), with ITO being the preferred material. Typically the material of first electrode 20 is sputtered as a layer over substrate 15 having a resistance of less than 250 ohms per square. In certain applications, the sputtered layer is patterned in any well known manner. Alternatively, first electrode 20 can be an opaque electrical electrode material such as copper, aluminum or nickel. If first electrode 20 is an opaque metal, the metal can be a metal oxide to create light absorbing first electrode 20 . First electrode 20 can be patterned by conventional lithographic or laser etching means.
A light modulating layer 30 which preferably is a polymer dispersed liquid crystal layer overlays first patterned electrodes 20 . In a first case, the liquid crystal material is a nematic liquid crystal. Cholesteric liquid crystal materials can be Merck BL12, BL48, available from EM Industries of Hawthorne, N.Y. Such materials have high anisotropy indices of diffraction, which can act as a light diffusing surface in the absence of an electric field and as a transparent sheet 10 in the presence of an electric field.
In a second case the liquid crystal is a cholesteric liquid crystal, having peak reflection from the infrared through the visible spectrum. Application of electrical fields of various intensities and duration can drive a chiral nematic material (cholesteric) into a reflective, a transmissive state or an intermediate state. These materials have the advantage of maintaining a given state indefinitely after the field is removed. Cholesteric liquid crystal materials can be Merck BL112, BL118 or BL126, available from EM Industries of Hawthorne, N.Y.
Second electrode 40 is formed over light modulating layer 30 . Second electrode 40 should have sufficient conductivity to carry a field light modulating layer 30 . Second electrode 40 can be formed in a vacuum environment using materials such as Aluminum, Tin, Silver, Platinum, carbon, Tungsten, Molybdenum, Tin or Indium or combinations thereof. Oxides of said metals can be used provide a dark second electrode 40 . The metal material can be excited by energy from resistance heating, cathode arc, electron beam, sputtering or magnetron excitation. Tin-Oxide or Indium-Tin Oxide coatings permit second electrode 40 to be transparent.
Alternatively, second electrode 40 can be printed conductive ink such as Electrodag 423SS screen printable electrical conductive material from Acheson Corporation. Such printed materials are finely divided graphite particles in a thermoplastic resin. In the preferred embodiment, second electrode 40 is formed using printable ink electrodes to produce a low cost display. The use of a flexible support for substrate 15 , laser etching to pattern first electrode 20 , machine coating light modulating layer 30 and printing second electrode 40 permits the fabrication of very low cost display sheets having memory.
The dispersion of liquid crystals in aqueous suspension is done in any conventional manner. One method is to disperse liquid crystal oils in deionized water containing dissolved gelatin. Other water soluble binders such as polyvinyl alcohol (PVA) or polyethylene oxide (PEO) can be used. Such compounds are machine coatable on equipment associated with photographic films. FIG. 2 is a plot of the dispersions of domain size for a liquid crystal oil in aqueous suspension. The oil domains have a size distribution around a mean diameter. A certain number are above a certain diameter D, and are called oversized domains 31 .
FIG. 3A is a section view of a typical liquid crystal oil dispersed in water coated over first electrode 20 and containing oversized liquid crystal oil domains 31 . Such coatings are dried to remove water from the suspension. FIG. 3B is a section view of the dried coating. The liquid crystal material is encapsulated by the water-soluble binder to create a pressure light modulating layer 30 . Oversize oil domains 31 can be significantly larger in diameter than the dry thickness of polymer dispersed liquid crystal layer 30 . Oversized oil domains 31 create coating defects 33 in the dried light modulating layer 30 .
FIG. 4A is a sectional view of a first, privacy light modulating layer 30 , which is a nematic liquid crystal material having high optical anisotropy. It has been found that 2-micron diameter domains of the liquid crystal in aqueous suspension converts incident light 54 into scattered light 58 in the absence of an electric field. In this case, polymer dispersed liquid crystal layer 30 within sheet 10 can be used as a privacy screen. The material is further provided with first electrode 20 and second electrode 40 on either side of polymer dispersed liquid crystal layer 30 so that an electrical field can be applied across the material. FIG. 4B is a sectional view of polymer dispersed liquid crystal layer 30 with an electrical field applied. Liquid crystal material within each domain is aligned by the electrical field, and sheet 10 will becomes transparent. Electrically switching between the light scattering and transparent state using an electric field provides an electrically switched privacy screen.
FIG. 5A is a sectional view of a privacy screen sheet 10 built in accordance with prior art. A second substrate 16 , having second electrode 40 is bonded to a substrate 15 having a first electrode 20 and a light modulating layer 30 . One method of bonding the two sheets of the privacy screens is to provide heat and pressure to bond second electrode 40 to light modulating layer 30 . Coating defect 33 creates an air filled cavity in sheet 10 . When sheets 10 , formulated for privacy screen window application, are manufactured and a field is applied, liquid crystals in light modulating layer 30 begins to permanently align in the transparent state, even in the absence of a field.
FIG. 5B is a sectional view of a sheet 10 built in accordance with the current invention. A protective layer 35 is aqueous coated over first electrode 20 . The dielectric layer was created by coating a 1.3% deionized gelatin solution at a rate of 0.38 cc per square meter. The resulting coating was about 0.5 microns thick. An emulsion of high anisotropy liquid crystal in a gel-water solution was coated over an ITO coated sheet of polyester. A second polyester sheet, also having an ITO coated surface was heat bonded over the dried light modulating layer 30 . The liquid crystal material in experimental sheet 10 did not begin to align in the direction of the electrical field after several weeks of application of an electrical field. It is believed that the gelatin dielectric layer acts to prevent alignment of the liquid crystal material with the gelatin encapsulated domain.
Dielectric protective layers can be built in to sheet 10 in a variety of ways. FIG. 5C is a sectional view of sheet 10 fabricated by coating a solution of gelatin over second electrode 40 to create protective layer 35 instead of between first electrode 20 and light modulating layer 30 . FIG. 5D is a sectional view of third embodiment. Protective layers 35 are coated over both first electrode 20 and second electrode 40 before assembly to provide a dielectric layer between both electrodes and light modulating layer 30 . These configurations are effective in preventing liquid crystal material in polymer dispersion from taking permanent alignment to long term electrical fields.
FIG. 6 A and FIG. 6B show two stable states of cholesteric liquid crystals. In FIG. 6A, a high voltage field has been applied and quickly switched to zero potential, which converts cholesteric liquid crystal to a planar state 50 . Incident light 54 striking cholesteric liquid crystal in planar state 50 is reflected as reflected light 56 to create a bright image. In FIG. 6B, application of a lower voltage field pulse leaves cholesteric liquid crystals in a transparent focal conic state 52 . Incident light 54 passing through a cholesteric liquid crystal in focal conic state 52 is transmitted. Second patterned electrodes 40 can be black which will absorb incident light 54 to create a dark image when the liquid crystal material is in focal conic state 52 . As a result, a viewer perceives a bright or dark image depending on if the cholesteric material is in planar state 50 or focal conic state 52 , respectively.
FIG. 7 is a plot of the response of a cholesteric material to a pulsed electrical field. Such curves can be found in U.S. Pat. Nos. 5,453,863 and 5,695,682. For a given pulse time, typically between 5 and 200 milliseconds, a pulse at a given voltage can change the optical state of a cholesteric liquid crystal. Voltage below disturbance voltage V 1 can be applied without changing the state of the cholesteric material. A higher voltage pulse at a focal-conic voltage V 2 will force a cholesteric material into the focal conic state 52 . A voltage pulse at planar voltage V 3 will force the cholesteric material into the planar state 50 . The curve characteristic of cholesteric liquid crystal permits passive matrix writing of cholesteric displays.
FIG. 8A is a sectional view of a coated cholesteric display sheet 10 . Substrate 15 supports a plurality of first electrodes 20 . A cholesteric liquid is has been dispersed in a gelatin solution, coated and dried to create light modulating layer 30 over first electrodes 20 . Second electrodes 40 are printed over light modulating layer 30 to provide a black, electrically electrodes that can be selectively energized to apply fields to the cholesteric liquid crystal in light modulating layer 30 . Coating defects 33 in light modulating layer 30 causes electrical shorting between first electrodes 20 and second electrodes 40 . Material adjacent to coating defect 33 cannot be switched between planar state 50 and focal-conic state 52 .
FIG. 8B is a sectional view of an experimental sheet 10 formed in accordance with the present invention. A protective layer 35 is aqueous coated and dried over first electrode 20 prior to application of the aqueous light modulating layer 30 . The dielectric layer was created by coating a 1.3% deionized gelatin solution at a rate of 0.38 cc per square meter. The resulting coating was about 0.5 microns thick. Sheet 10 assembled, incorporating protective layer 35 and electrically tested. The 0.5 micron thick protective layer was effective in preventing image defects due to coating and provides effective insulation between electrodes used in changing the state of cholesteric liquid crystals.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST
10 sheet
15 substrate
16 second substrate
20 first electrode
30 light modulating layer
31 oversized domains
33 coating defect
35 protective layer
40 second electrode
50 planar liquid crystals
52 focal-conic liquid crystals
54 incident light
56 reflected light
58 scattered light
V 1 disturbance voltage
V 2 focal-conic voltage
V 3 planar voltage
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A method of making a liquid crystal display, comprising the steps of: providing a substrate; providing a first electrode over the substrate; coating the first electrode with aqueous dispersed material which when dried provides a dielectric layer over the first electrode; coating the dielectric layer with liquid crystal bearing material and drying such liquid crystal bearing material and providing a second electrode in contact with the dried liquid crystal bearing material.
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BACKGROUND OF THE INVENTION
This invention is concerned with locating and tracing concealed elongated conductive objects, such as pipes or cables, and is more particularly concerned with improved locating and tracing of a first object when a second object is adjacent to the first.
In the prior art, there are two general techniques of locating buried metallic objects. A passive technique employs a gradiometer or the like as a magnetic locator for detecting the presence of ferrous metal objects, such as iron and steel pipes, iron markers, manhole covers, well casings, etc. An active technique uses a transmitter to induce alternating currents in non-ferrous metal pipes, power cables, or communication cables, for example, and a receiver to sense magnetic fields associated with the currents.
The model MAC-51B Magnetic and Cable Locator manufactured by the assignee of the present invention is designed for selective active or passive use. When apparatus of this type is employed to locate and trace a cable (or non-ferrous pipe), for example, a transmitter may be disposed on the ground at a position close to the location (or suspected location) of a portion of the cable so as to induce an alternating current therein that may be traced by moving a receiver back and forth over the ground. When there are no interfering objects close to the cable being traced, this system works admirably, producing a distinct single null in the output signal of the receiver when the receiver is located directly over the cable and is oriented so as to sense a vertical component of a circumferential magnetic field associated with the current in the cable. When, however, another cable (or pipe) is present adjacent to the first cable, e.g., within a few feet of the first cable and extending in the same general direction, the single null output signal characteristic of the receiver becomes distorted, and tracing of the desired cable may become difficult.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides a system and method that improves substantially the ease and accuracy of locating and tracing of one concealed object, such as a buried pipe or cable, in the presence of an adjacent object.
In one of the broader aspects of the invention, a system for locating at least one of a pair of concealed, elongated, conductive, adjacent objects, comprises, in combination, a transmitter and a receiver, said transmitter having means including a pair of antennae for inducing a pair of distinguishable alternating currents in said objects, respectively, said receiver being movable relative to said transmitter and to said objects, having means for sensing magnetic fields associated with said currents, respectively, and having means for producing an output signal dependent upon the sensing of both of said fields.
In another of the broader aspects of the invention, a method of locating at least one of a pair of concealed, elongated, conductive, adjacent objects comprises producing in said objects a pair of distinguishable alternating currents, respectively, moving with respect to said objects a receiver sensitive to a pair of magnetic fields associated with said currents, respectively, and producing an output signal from said receiver dependent upon the sensing by said receiver of both of said fields.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described in conjunction with the accompanying drawings which illustrate preferred (best mode) embodiments, and wherein:
FIGS. 1 and 2 are diagrammatic views illustrating the use of prior art apparatus in locating and tracing a buried cable;
FIG. 3 is a diagrammatic view illustrating an output signal characteristic when a prior art receiver encounters a pair of adjacent cables (or pipes);
FIG. 4 is a diagrammatic view illustrating transmitting apparatus in accordance with the invention;
FIG. 5 is a diagrammatic view illustrating an optimum position of the transmitting apparatus with respect to a pair of buried pipes or cables;
FIG. 6 is a view similar to FIG. 3 and illustrating an improvement in the output signal characteristic due to the invention;
FIG. 7 is a view similar to FIG. 5 but illustrating the transmitting apparatus in a non-optimum position;
FIG. 8 is a view similar to FIG. 6 and illustrating the output signal characteristic for the disposition of the transmitting apparatus in FIG. 7;
FIG. 9 ,is a block diagram of transmitting apparatus employed in the invention;
FIG. 10 is a block diagram of receiving apparatus employed in the invention; and
FIG. 11 is a diagrammatic view illustrating a modification of transmitting antennae orientation.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates, diagrammatically, the use of the aforesaid model MAC-51B Cable Locator to locate and trace a buried cable (or pipe) C. A transmitter T with a loop antenna A is placed on the ground over a portion of the cable C (a portion that is known or located experimentally) and generates an electromagnetic field F that is coupled to the cable C and that induces in the cable an alternating current. The current has a circumferential field F' associated therewith that is sensed by a receiver R moved back and forth over the ground by an operator O. Apparatus of this type is well known and need not be described in detail.
As shown in FIG. 2, in which the cable C extends perpendicular to the plane of the drawing, when the receiver R is held vertically (so as to sense a vertical component of the field F') and is moved back and forth across the cable C (three positions of the receiver being illustrated), an output signal characteristic S is produced having a null N directly over the cable and two lobes L and L' at opposite sides of the cable. By sweeping the receiver back and forth across the cable while moving along the general direction of the cable, the position of the cable may be readily traced.
When a second cable (or pipe) C' is present adjacent to the first as shown in FIG. 3, the output signal characteristic S may be distorted so that the null N is located between the cables and one of the side lobes has a substantially greater amplitude than the other. The configuration of the output signal characteristic depends, for example, upon the depth of the second cable C' relative to the first cable C, the distance between the cables, and their relative size and conductivity. Thus, when two cables are present, running generally in the same direction, tracing of the desired cable may become difficult. The present invention alleviates this problem to a substantial degree, as will now be described.
As shown in FIG. 4, the invention employs a transmitter T' having a pair of antennae A' and A" that are preferably spaced a few feet apart (say 3-5 feet), that are driven by RF signals, and that generate corresponding magnetic fields F1 and F2. Each of the antennae A' and A" may comprise 100 turns of No. 14 wire wound on a 1/2 inch by 8 inch ferrite rod, for example. As described in more detail hereinafter, the signals that drive the antennae are distinguishable, and the fields F1 and F2 induce corresponding distinguishable currents in cables C and C', respectively. As shown in FIG. 11, the orientation of the antennae may be changed from the horizontal orientation shown in FIG. 4 to enhance the inducement of currents in the respective cables.
The transmitting apparatus is optimally positioned relative to the cables as shown in FIG. 5. Sometimes sufficient information as to the location of at least part of the cables is available to permit such positioning initially. At other times, however, such information is not available, and the transmitting apparatus may be initially positioned as shown FIG. 7, i.e., centered over one of the cables, or even completely beside the cables. Usually, sufficient information is available to determine at least the approximate location of a portion of a cable (or pipe) to be located and traced. After initial tracing, using a receiver R of the type referred to earlier, for example, the position of the transmitter may be moved to the position of FIG. 5 to optimize further tracing operations.
As described hereinafter in more detail, the system of the invention is capable of producing two distinct output signal nulls N and N' over respective cables C and C', as shown in FIG. 6. It is thus possible to locate and trace one of the cables (or even both cables) more easily and accurately than with prior art systems and methods. As is apparent in FIG. 6, lobes L and L' are located at opposite sides of the cable C, and although these lobes may have different amplitudes, the null N is readily perceived.
When the transmitting apparatus is located as shown in FIG. 7, the output signal characteristic may have the configuration shown in FIG. 8, in which one of the lobes L', is substantially distorted. By moving the location of the transmitting apparatus in the direction of the distorted lobe L', it is possible to arrive at the position shown in FIG. 5 and to produce an output signal having the characteristic shown in FIG. 6. The output signal characteristics shown in FIGS. 6 and 8 may be shifted upwardly or downwardly with respect to a base line by adjustment of a receiver deadband control, for example.
When the receiver R is employed to trace a cable C in the presence of an adjacent cable C', the receiver will normally be swept back and forth across both cables to facilitate the desired positioning of the transmitter and to monitor the total output signal characteristic as the receiver is moved in the general direction of the cable(s) to be traced. In accordance with the invention, output signal characteristics of the type shown in FIGS. 6 and 8 are produced only when the receiver senses both fields associated with the currents in the respective cables, which are distinguishable. Among the techniques that may be employed to make the currents distinguishable from one another and to produce an output signal dependent upon the presence of both currents are: (1) currents having different carrier frequencies that may be combined to produce a beat frequency, (2) currents having the same carrier frequency amplitude-modulated by different frequencies that may be combined to produce a beat frequency, and (3) currents that are pulsed at different repetition rates that may be combined to produce a beat frequency. Other techniques may also be employed to distinguish the currents in the respective cables and to produce an output signal dependent upon the presence of both currents.
As shown in FIG. 9, in a first embodiment the transmitter T' has carrier generators t and t' that produce sinusoidal carrier currents of 82.300 KHz and 82.682 KHz, for example, which drive antenna A' and A", respectively. The carrier frequencies when detected in the receiver R, will produce a beat frequency signal of 382 Hz. To produce a pulsating audio output signal which is easier for the operator to distinguish from background noise than a steady tone, each of the carrier frequencies may be pulsed on and off at a 6 Hz rate, for example, by a pulse generator t".
FIG. 10 illustrates a typical receiver employed in the invention (which may be similar to the receiver of the model MAC-51B Magnetic and Cable Locator referred to earlier). The fields associated with the currents in the cables C and C', for example, are sensed by a sensor coil 10 (which may be wound upon a ferrite core) producing a combined signal that is supplied to an 82.5 KHz amplifier 12. The amplified signal is detected in an 82.5 KHz detector (demodulator) 14. The amplifier 12 amplifies both the 82.300 KHz and the 82.682 KHz carrier components in the combined signal from coil 12, and the detector 14 (a non-linear circuit) detects the envelope of the amplified signal and produces a 382 Hz beat frequency signal (pulsating at 6 Hz) when both components are present. A filter 16 passes the 382 Hz beat frequency signal to a variable gain amplifier 18, and the amplified beat frequency signal is applied to a 382 Hz detector 20. A 6 Hz pulsating signal from detector 20 (a non-linear circuit) is passed by a low pass filter 22 to a voltage controlled oscillator 24, which produces a variable frequency signal that is amplified by an audio amplifier 26 to produce a pulsating output signal that is supplied to a speaker 28.
If, instead of using different carrier frequencies to drive the respective antennae A' and A", the same carrier frequency is used, both currents may be amplitude modulated by the same 382 Hz modulation frequency but pulsed at different and asynchronous pulse rates, such as 20.12 Hz for one antenna and 23.87 Hz for the other. The two signals will blend in the receiver and produce 20.12 Hz or 23.87 Hz pulsations of a 382 Hz signal at the output of detector 20 when a signal from only one cable is present and will produce a beat frequency signal of 3.75 Hz at the output of detector 20 when signals from both cables are present. Thus, if the low pass filter 22 is set to reject frequencies above 4 Hz, for example, an output signal from the speaker 28 will only be produced when currents in both cables are sensed by the receiver.
As a further alternative, the same 82.5 KHz carrier (pulsed on and off at 6 Hz, for example) may be employed for both antennae but modulated at 1288 Hz and 906 Hz, respectively, which will produce a pulsating beat frequency signal of 382 Hz at the output of detector 14 when the currents in both cables are sensed. This signal may be processed as in the first embodiment.
The invention is especially useful in an environment in which the horizontal separation s between the cables is related to the depth d of the cable to be located and traced in accordance with the relationship s<11/2d. The effect achieved by the invention is enhanced by the fact that the field from the transmitter, and hence the excitation at a cable, decreases by the inverse cube of the distance between an antennae and a cable. For example, if the cables and the antennae were each separated horizontally by 3 feet and the cables were buried 3 feet, then a signal due to a given antenna in a cable under that antenna would be 2.8 times stronger than a signal due to that antenna in a cable 3 feet to one side of the antenna. This phenomenon substantially reduces the inducement of currents from both antennae in the same cable when the transmitter is properly positioned. It also enhances the desired performance of the receiver, which may be optimized by adjustment of a threshold sensitivity control (indicated in FIG. 10).
While preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims. For example, the transmitter may be designed so that only one of the antennae may be energized (e.g., by a modulated 82.5 KHz carrier as in the aforesaid Model MAC-51B) for cable locating and tracing when only a single cable is present.
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Locating and tracing of a concealed, elongated, conductive object, such as a buried pipe or cable, is enhanced, when a second such object is adjacent to the first, by employing a transmitter having a pair of antennae that induce distinguishable currents in the respective objects. A receiver movable with respect to the transmitter and with respect to the objects produces an output signal dependent upon the sensing of fields associated with both currents. The position of the transmitter relative to the objects is adjusted to optimize the output signal.
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This is a continuation of application Ser. No. 08/077,178 filed on Jun. 15, 1993, now abandoned.
FIELD OF THE INVENTION
The present invention relates to the production of an improved indicium or indicia on the surface of articles, especially contact lenses.
BACKGROUND OF THE INVENTION
Proper identification of contact lenses is important. Since most contact lens wearers have a different prescription for each eye, the optical power of each contact lens often differs. In addition, the use of an identifying indicium or indicia on a contact lens can be used by the wearer not only as a means of distinguishing lenses from each other, but distinguishing one side of a lens from the other. For example, an indicium or indicia can be used as an inversion indicator to determine if the lens is being put in the eye correctly (i.e. with the proper side of the lens against the eye). Indicia, together, can form lot and batch numbers on the lenses for identification purposes.
Quality control personnel must be able to identify and orient the lens quickly for further inspection. Lens inspectors often have only a limited amount of time to inspect each lens. The lenses must therefore be oriented consistently to begin the inspection process. Often an indicium, or indicia on the lens, such as a logo, is used to orient the lens. Since each individual lens inspection must be done quickly, a highly visible indicium or indicia which assists the inspector in orienting the lens is important.
In many instances, the indicium is difficult to locate due to the lack of contrast between the appearance of the indicia and the lens itself. An identification mark which has sufficient contrast to be easily visible when the lens is not on the eye but relatively invisible when on the eye would be of great advantage to lens wearers, dispensing practitioners, inspectors and anyone who handles such lenses.
SUMMARY OF THE INVENTION
The present invention is a method of improving the visibility of an indicium or indicia on an optically clear surface (when the lens is not on the eye) comprising forming an indicium or indicia having a pattern of regions of varying depth within the boundaries of each indicium. In a preferred embodiment, some of the regions of each indicium are the same height as the surface of the lens. Other regions within the pattern, which may be alternating regions, do not extend to the surface of the lens, and therefore comprise a subsurface region of depressions relative to the lens surface.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a magnified cross-sectional view of an indicium, "B", on a contact lens
FIG. 2 shows a magnified schematic representation of an indicium, "B", according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, a magnified cross-sectional perspective of an indicium (2) as contemplated by the present invention displays the pattern of regions of varying depth formed at or near the surface of a contact lens. It is believed that the pattern of regions of varying depth creates the conditions necessary for light to be bent in complex ways leading to areas of reflectance and absorbance. The regions of varying depth cause a series of "dark" shadowed areas (1) at the subsurface of the indicium (3) which contrast sharply with the "light" clear areas of the indicium and on the surface of the lens (4). Such contrast makes the indicium significantly more visible than the indicium ordinarily produced which has an imprint of only one depth.
FIG. 2 shows a top view of the letter "B" indicium (2). From this view the "dark" shadowed areas (1) are prominently shown, and contrast sharply with the "light" surface areas of the indicium (4).
One way of enhancing the visibility of a lens indicium formed by a single depression cut or molded into a lens surface was to increase the opacity of the depression. Such opacity, however, is the result of "roughed-up" surfaces in the depression which, in turn, increases surface area. Additional surface area is not desirable for an article such as a contact lens which must remain sterile. The microscopic crevices created by the "roughed-up" surface at the bottom of the indicium may allow biological matter and impurities to adhere and collect.
It is believed that the present invention presently benefits from the shadowed effect created by the repeating pattern of regions of varying depth which alter the path of light, or "bend" light, causing the effect of easily perceptible areas of bright regions and dark regions within the boundaries of the indicium.
It is understood that a logo may be formed by an indicium, or indicia taken together. For example, for the purposes of this application, "B&L" is a logo comprised of three indicium (collectively considered indicia). When a lens is marked, according to this invention, depressions are created along with surface regions. Both the depressions and the surface regions form a pattern, the boundaries of which form the indicium.
When an article such as a contact lens is held by a wearer in ambient light (naturally occurring light), the enhanced indicium has been shown to be easily visible. The unaided human eye appears to be able to more quickly perceive the indicium due to the contrast provided by the multiple shadowed regions of the indicium of the present invention, which show up distinctly against the transparent lens. In ambient light, the indicium may appear "whitish" or translucent to the wearer when held up to the light. Such easy location and identification of the indicium assures that the proper lens surface will be placed against the eye when the lens is inserted in the eye.
A highly visible indicium or indicia on a lens also is helpful to the practitioner who must check and match the power of the lens according to the wearer's prescription. Symbols representing lens power and other identifying information useful to the practitioner may be marked on the lens.
Similarly, the highly visible indicium of the present invention is useful to the lens quality control personnel responsible for inspection of the lenses. The additional light supplied to the instrumentation used for inspecting the lenses, appears to illuminate the indicium in such a way as to offer significant contrast as against the transparent lens being inspected. When the lens having the indicium of the present invention is inspected at magnification with additional light provided, the indicium will show clear, or white areas at the surface regions, and darker, shadowed areas at the depressions. The indicium is thus spotted quicker and easier by the inspectors, causing considerably less eye strain and fatigue. More lenses can therefore be inspected in shorter amounts of time which may significantly improve overall lens processing and quality control.
The lenses may be marked by methods well known in the tooling and contact lens field. The tools used to make the mold for cast molding procedures are often constructed of stainless steel or are stainless steel with various nickel or nickel alloy plate coatings. The tools may be treated via acid etching, laser, electrolysis, or according to other methods known by those skilled in the field to imprint the desired indicium. The tools may then be integrated into the injection molding procedures used to make the molds. The indicium therefore, according to one embodiment, is imprinted into the mold. When the monomer mix is compressed and cured between the mold halves during cast molding, or spun cast and cured, the indicium from the tool which is imprinted on the mold is transferred to the lens through methods well known to those skilled in the field.
According to one embodiment of the present invention, lasers can be used to mark lenses which are made according to other methods including cast molding. Suitable masks could be used in concert with lasers known to be effective for etching contact lens type materials, such as UV excimer lasers emitting at wavelengths of about 200 nm. The masks could conceivably have the indicium cut into them which could then be imparted to the lens. Further, laser processing may be used which does not involve the use of masks, but which directly etches the target (in this case the lens), the mold or the tool.
While parallel regions of alternating depth, which may appear as stripes, have been found to provide excellent contrast and therefore offer enhanced visibility over known indicium which are of only one depth, it is understood that many configurations, geometric and random, may produce suitable contrast and also be more visible. For example, a pattern of circles, or dots have been produced with good results of causing enhanced contrast. Indeed, any shape or pattern, both regular and repeating, or random in nature may produce the desired results, so long as the pattern comprises one region which has essentially the same surface characteristics of the surrounding substrate, and another subsurface region, or depression, which is of a depth sufficient to create suitable visible contrast.
The additional contrast and visibility provided by the indicium of the present invention on articles such as contact lenses may enable the indicium to be marked not as deeply into the surface of the lens. This would reduce the surface area where biological matter and other impurities often collect. Since the marks need not be as deep as is conventionally done, it may be possible to produce thinner lenses which may increase comfort.
The following example serves only to further illustrate aspects of the present invention and should not be construed as limiting the invention.
EXAMPLE
Process for Etching Tool Used to Make Lens Mold
The stainless steel tool was degreased by dipping the tool into a methylene chloride bath. The tool was then air dried and inspected using a microscope at 20× magnification. The tool was then handled with cotton gloves and mounted onto a spinning fixture used to hold the tool which was then attached to a motor capable of spinning the tool at a rate of 3600 RPM. The motor was engaged and the tool spun at 3600 RPM while being lowered into a cup of photo resist material (Baker 1-PR-21 analyzed positive resist 820 VSLI low particle grade) for 5 seconds. The tool was removed from the cup and spun for an additional 30 seconds. The tool was removed from the spinning fixture and inspected at 20× magnification. If any particles were detected the above procedures would be repeated. The tool was then placed in a holding rack in an oven an baked at 90 degrees C. for 15 minutes. When a nickel coated stainless steel was used, the baking time was 30 minutes. The tool was then removed from the oven, cooled and inspected under the microscope at 20× magnification.
The "B&L" logo was then etched onto the tool using UV radiation from a source at an intensity of 5 amperes. A locating means for locating the logo which was on a film mask on the tool was selected. The tool was placed in a holding means and aligned with the UV source. The tool was exposed to the UV source through the mask for 5 seconds. The tool was then removed from the holding means and dipped in the developer (100% Positive Resist Developer, OCG Micro Electronics Materials, Inc., West Patterson, N.J.) which is prepared to a concentration of 50% water/50% developer. The tool was then inspected at 20× magnification for defects. At this point, photo resist has been removed from the tool surface in the shape of the logo to be etched into the surface of the tool. The tool was then placed in a holding rack under a fume hood. A water/ferric chloride (50/50) solution was used to etch stainless steel. A nitric acid/water/hydrofluoric acid solution (5 parts/6 parts/2 parts) was used to etch a nickel coated stainless steel tool. A blunt polyethylene stick was used to dip into the acid solution, and a drop of acid was placed on the exposed logo without touching the stick to the surface of the tool, leaving acid on the tool for 2 minutes on the stainless steel (and 1 minute on the nickel coated tools). The tool was then washed with water and inspected under the microscope (20× magnification). The tool was then cleaned without wiping by dipping in acetone followed by air drying.
The finished tool was then placed into a cavity block which was placed into position in an injection molding machine used to make the contact lens mold.
Many other modifications and variations of the present invention are possible to the skilled practitioner in the field, in light of the teachings herein. It is therefore understood that, within the scope of the claims, the present invention can be practiced other than as herein specifically described.
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A method of improving the visibility of indicia marked into an optically clear surface is disclosed comprising marking a pattern of varying depths within the boundaries of the indicia.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording/reproduction apparatus for a disk-shaped information medium and, more particularly, to a disk recording/reproduction apparatus which can load different types of disk media into the recording/reproduction apparatus and can rotate them.
2. Related Background Art
Conventionally, upon loading a disk-shaped recording medium (to be referred to as a disk hereinafter) into a drive unit of a disk recording/reproduction apparatus, as a method of setting the disk on a turntable, two methods, i.e., a magnet clamp method and a mechanical clamp method, are normally used.
A disk clamp mechanism based on the conventional mechanical clamp method has the structure shown, in e.g., FIG. 1. The mechanism includes a disk 101 having a central hole 102, a spindle 150 for rotating the disk, a turntable 151 for rotating the disk set thereon, a tapered cone 152 which is vertically slidable along the spindle 150 to perform centering of the disk on the turntable 151, a compression coil spring 153 for biasing the tapered cone 152 upward in FIG. 1, and a disk pressing member 154 for pressing the disk from above. A magnet is fixed to the disk pressing member 154 to magnetically attract the disk toward the turntable 151 side.
In the disk clamp mechanism with the above-described arrangement, the tapered cone 152 is inserted into the central hole 102 of the disk, and the peripheral portion of the tapered cone 152 is fitted in tight contact with the central hole 102 of the disk to perform centering of the disk. In this state, the disk 101 is fixed to the turntable 151 by the disk pressing member 154 by the attraction force between the magnet fixed to the disk pressing member and the turntable 151.
On the other hand, a disk clamp mechanism based on the conventional magnet clamp method has a structure, as shown in, e.g., FIG. 2. The mechanism includes a disk 111, a hub 112 consisting of a magnetic material, and a magnet 113 for magnetically attracting the hub 112 to a turntable.
In the disk clamp mechanism with the above arrangement, a spindle 150 is inserted into the central hole of the hub 112 to perform centering. In this state, the disk 111 is fixed to a turntable 156 by the attraction force between a magnet 157 and the hub 112.
As a versatile disk clamp mechanism, which can set and clamp different types of disks, applied to the above-mentioned two different clamp methods, on a single turntable, a mechanism described in Japanese Laid-Open Patent Application No. 6-150504 is known, as shown in, e.g., FIGS. 3A and 3B.
In this prior art, a tapered cone for performing centering of a disk without any hub (see FIG. 3A), and a spindle for performing centering of a disk with a hub (see FIG. 3B) are coaxially arranged, and the mechanism can selectively set and drive these disks on a single spindle and turntable using a magnetic force.
As another versatile disk clamp mechanism, as shown in FIG. 4, a mechanism described in Utility Model Application No. 3004098 is known. Since this mechanism has two disk support surfaces with different heights on a single turntable, disks with different clamp areas can be clamped on the single turntable.
However, despite the disk clamp mechanism shown in FIGS. 3A and 3B or FIG. 4 is arranged, when disk support positions are different in the radial direction of the disk, as shown especially in FIG. 4, the following problem is posed independently of the clamp methods. More specifically, in a disk clamp mechanism for a disk which is loaded into a cartridge in advance, when the cartridge has a small turntable insertion hole in correspondence with the small support diameter of the disk, if the turntable insertion hole is larger than the support diameter of another disk, a support portion of the turntable side, that supports the larger support-diameter portion, spatially interferes with the cartridge case, and it becomes impossible to support the cartridge storage type disk on the turntable.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above situation, and has as its object to provide a versatile disk recording/reproduction apparatus with a disk clamp mechanism which can set different types of disks on a turntable even when the support diameter of one disk is larger than the diameter of a turntable insertion hole formed on a cartridge case of the other cartridge storage type disk.
The above-mentioned object is achieved by the following characteristic arrangement.
That is, there is provided a disk apparatus which can cope with a first disk having a central hole, and a second disk, which has a central hole smaller than the central hole of the first disk and has a hub containing a magnetic material, comprising:
a spindle, which is fitted in the central hole of the second disk, to perform centering of the second disk; and
a turntable arranged on the spindle,
the turntable comprising:
a magnet for attracting the hub so as to hold the second disk on the turntable;
a first support surface, which contacts a disk surface of the second disk at a position outside the hub and supports the second disk; and
a caddie for holding the first disk upon loading the first disk into the apparatus, and
the caddie comprising:
a fitting portion, which is fitted into the central hole of the first disk to perform centering of the first disk and comprises a magnetic portion to be attracted by the magnet; and
a sub-turntable, which is arranged to oppose the fitting portion to sandwich the held first disk therebetween, the sub-turntable being supported by the turntable upon loading the caddie into the apparatus, and clamping the first disk in cooperation with the fitting portion.
Also, there is provided a disk apparatus which can cope with a first disk having a central hole, and a second disk, which has a central hole smaller than the central hole of the first disk and has a hub containing a magnetic material, comprising:
a spindle, which is fitted in the central hole of the second disk to perform centering of the second disk; and
a turntable arranged on the spindle,
the turntable comprising:
a magnet for attracting the hub so as to hold the second disk on the turntable;
a first support surface which contacts a disk surface of the second disk at a position outside the hub and supports the second disk; and
a clamp member for clamping the first disk in cooperation with the turntable, and
the clamp member comprising:
a fitting portion, which is fitted into the central hole of the first disk to perform centering of the first disk and comprises a magnetic portion to be attracted by the magnet; and
a second support surface, which contacts a disk surface of the first disk at a position outside the first support surface and clamps the first disk in cooperation with the first support surface.
The above and other objects and features will become apparent from the following description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a disk clamp mechanism based on a conventional mechanical clamp method;
FIG. 2 is a sectional view showing a disk clamp mechanism based on a conventional magnet clamp mechanism;
FIGS. 3A and 3B are sectional views showing a state wherein disks of two different clamp methods are clamped by a single disk clamp mechanism;
FIG. 4 is a sectional view especially showing a state wherein disks of two different clamp methods, which have different clamp areas, are clamped by a single disk clamp mechanism;
FIG. 5 is a perspective view for explaining a case wherein a disk clamp mechanism according to the first embodiment of the present invention is applied to a second disk;
FIG. 6 is a perspective view for explaining a case wherein the disk clamp mechanism according to the first embodiment of the present invention is applied to a first disk;
FIG. 7 is a side sectional view showing a state wherein the first disk is set on the disk clamp mechanism according to the first embodiment of the present invention;
FIG. 8 is a side sectional view showing a state wherein the second disk is stored in a cartridge case and is set on the disk clamp mechanism according to the first embodiment of the present invention;
FIG. 9 is a side sectional view for explaining the setting state of a clamper, a spindle motor, and a first disk according to the second embodiment of the present invention;
FIG. 10 is a side sectional view the setting state in correspondence with FIG. 9;
FIG. 11 is a side sectional view showing a state wherein a second disk loaded into a disk cartridge is set on a turntable in the second embodiment of the present invention; and
FIG. 12 is a side sectional view showing the setting state in correspondence with FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the present invention will be described in detail hereinafter with reference to FIGS. 5 to 8. FIGS. 6 and 7 show a disk clamp mechanism to be applied to a cartridge storage type disk, such as an ISO standard 3.5" MOD. In this case, the clamp mechanism comprises a spindle 23 which performs centering of a disk set at the recording/reproduction position in the apparatus, and is rotated, and a turntable 20 on which the disk is set. A magnet 22 arranged on the turntable 20 attracts and holds the disk.
In this disk clamp mechanism, for a first disk having a hub 31, consisting of a magnetic material, around a central hole 33 to be fitted on the spindle 23, i.e., a disk 32 stored in a cartridge case 30 in this embodiment, the above-mentioned magnet 22 is arranged to oppose the hub 31, and the above-mentioned turntable 20 has an annular support portion 25 which contacts the disk surface outside the hub 31. The support portion 25 determines the position, in the axial direction of the spindle 23, of the disk.
On the other hand, as shown in FIGS. 5 and 8, as for a second disk, such as a compact disk having a central hole 1a larger than the central hole 33, a disk 1 is set on the turntable 20 via a clamper 3 and a sub-turntable 4, which clamps the disk 1 in combination with the clamper 3 and is set on the turntable 20.
That is, the clamper 3 has a fitting/holding portion 3c (in this embodiment, its outer peripheral portion has a tapered cone shape) to be fitted in a central hole 1a of the disk 1, a central hole 3a to be fitted on the spindle 23, and a to-be-attracted portion 3b which opposes the magnet 22 and consists of a magnetic material.
The above-mentioned clamper 3 and the sub-turntable 4 are respectively rotatably mounted on an upper portion (case lid) 10 and a lower portion (case main body) 8 of a cartridge case 2, which is free to open/close vertically. The second disk 1 is loaded into the cartridge case, and is clamped vertically between the clamper 3 and the sub-turntable 4 in the closed state of the cartridge case.
More specifically, the support portion 25 is located outside the fitting/holding portion 3c, and the sub-turntable 4 has an annular support portion 4b which contacts the disk surface of the second disk 1 to hold the second disk 1 at the same height level as that of the first disk 32. Note that the sub-turntable 4 is detachably fitted on the turntable 20 while its annular lower surface 4c is placed on a rest portion 21 formed on the outer periphery of the turntable 20. On the other hand, the cartridge case 2 has, on its lower portion 8, an opening portion 7 which opposes the moving region of a pickup head used for recording/reproduction, and a space portion 9 for storing the disk 1.
In this arrangement, as shown in FIG. 7, when the turntable 20 is inserted into the opening formed at the center of the lower surface of the cartridge case 30, the hub 31 is magnetically attracted by the magnet 22, and the central hole 33 is fitted on the spindle 23, thereby determining the radial position of the disk. On the other hand, the lower surface of the first disk 32 contacts and engages with the top surface of the support portion 25 of the turntable 20, thus determining the position, in the axial direction of the spindle 23, of the disk. In this state, the clamping operation is completed.
In this case, when the support portion 25 is formed at a position that does not interfere with the opening portion, opposing the pickup head, and the lower surface of the cartridge case 30, the disk clamp mechanism of the present invention can be applied to the above-mentioned cartridge storage type disk 32.
As shown in FIG. 5, the second disk 1 is stored in the space portion 9 of the cartridge case 2, and the upper portion 10 is closed. At the same time, the fitting/holding portion 3c of the clamper 3 is fitted into the central hole 1a of the disk 1. In this case, a snap fit holding member (not shown), provided to the lower portion 8, maintains the closed state. The disk 1 in this state is loaded into the disk recording/reproduction apparatus together with the cartridge case 2, and is clamped on the turntable 20 via the clamper 3 and the sub-turntable 4, as shown in FIG. 8.
That is, when the turntable 20 is inserted into the central opening portion formed on the lower portion 8 of the cartridge case 2, the to-be-attracted portion 3b of the clamper 3 is magnetically attracted by the magnet 22, and the central hole 3a of the clamper 3 is fitted on the spindle 23. Since the clamper 3 slightly moves downward due to the magnetic attraction, the disk 1 contacts the support surface 4b of the sub-turntable 4, and the central hole 4a is fitted on the outer circumferential portion of the support portion 25 of the turntable 20. Also, the lower surface 4c contacts the upper surface of the rest portion 21, thus completing the clamp operation.
In this case, since the central hole 1a of the disk 1 is fitted on the tapered portion 3c of the clamper 3 aligned by the spindle 23, the radial position of the disk is determined. On the other hand, since the clamper 3 slightly moves downward, the lower surface 4c contacts the rest portion 21 via the disk 1, thus determining the position, in the axial direction of the spindle 23, of the disk.
In this embodiment, the rest portion 21 formed on the turntable 20 protrudes from the outer periphery of the turntable 20, but may have a stepped axial shape. Furthermore, the rest portion 21 need not always be formed into an annular shape but may be formed intermittently in the circumferential direction at least, e.g., at three positions.
The second embodiment of the present invention will be described below with reference to FIGS. 9 to 12. FIGS. 9 and 10 are side sectional views showing the setting state of a first disk, such as a CD (compact disk), having only the central hole. FIGS. 11 and 12 are side sectional views for explaining the setting state of a second disk which has a central hole smaller than that of the first disk and has a hub including a magnetic material, and more particularly, a disk such as a 3.5" MOD loaded into a cartridge, in which a central opening portion, for receiving the shaft of a spindle motor, is defined by a hole smaller than the diameter of a clamp region for the first disk. That is, the second embodiment of the present invention comprises a mechanism for selectively setting the two different types of disks on the shaft of a single spindle motor 201. The mechanism will be described in detail below.
When the first disk (220) is to be set, the first disk 220 is conveyed by a tray 250 (broken line) arranged in a disk apparatus to a position at which the central position of a clamper 210 roughly matches that of the disk 220. The clamper 210 is constituted by a pressing member 217 which biases balls 216 in the direction of an arrow D in FIG. 9 using a compression coil spring 218, a holding portion 211 formed with a flange surface 213 which contacts the clamp region of the disk 220, and a distal end portion 214 comprising a contact portion contacting a first support surface 203 of the spindle motor, a hole 215 fitted on a rotation shaft 202 of the spindle motor, and a member which includes a ferromagnetic member in at least a portion facing the spindle motor.
When a disk type identification means (not shown) determines the first disk, a clamper loading mechanism (not shown) is driven by a control means (not shown) in a state wherein the first disk is placed and held on the tray 250 (the clamper 210 is located at a broken line position in FIG. 9), thereby moving the clamper 210 downward.
When the distal end portion 214 of the clamper is fitted in the central hole of the disk and is further inserted, the balls 216, which are elastically biased outward in the radial direction of the disk, pass the central hole of the disk, and press the edge portion of the central hole on the opposite surface of the disk to bring the clamp region of the disk 220 into contact with the flange surface 213, thus holding the disk by the biasing force (see FIG. 9). In this state, the positions, in the radial direction of the disk and in the direction of the rotation shaft, of the disk 220 are determined with respect to the clamper 210.
The spindle motor 201 has the first support surface 203 which contacts the distal end portion 214 of the clamper to determine the position, in the direction of the rotation shaft, of the disk 220, a second support surface 204 which contacts the clamp region of a second disk 231 to determine the position, in the direction of the rotation shaft, of the disk, the rotation shaft 202 which is fitted in the central hole 215 of the clamper 210 and a central hole 232a of the hub of the second disk 231 to determine the radial position of the first and second disks, and a magnet 205 which magnetically attracts the clamper 210 and the hub of the second disk 231.
After the disk 220 is held by the clamper 210, the tray 250 is moved downward in the direction of the arrow D in FIG. 9 by the tray loading mechanism (not shown). After the tray 250 moves downward, the central hole 215 is fitted on the rotation shaft 202 to determine the radial position of the disk. At the same time, since the distal end portion 214 of the clamper 210 is constituted by the member including the ferromagnetic member, the distal end portion 214 of the clamper 210 is attracted by the magnet 205, and contacts the first support surface 203. Thus, the holding state of the disk on the spindle motor is maintained by the attraction force of the magnet 205, and at the same time, the position, in the direction of the rotation shaft, of the disk is determined. The tray 250 further moves downward and is separated away from the disk 220, thus completing the setting operation (see. FIG. 10).
When the first disk is to be removed, the tray 250 is moved upward together with the clamper 210, which holds the disk 220, so as to separate the clamper 210 away from the spindle motor 201 against the attraction force of the magnet 205. In order to detach the disk 220 from the clamper 210, the tray 250 is moved upward to the position where the clamper 210 was attached to the disk 220 (see FIG. 9). When the clamper 210 further moves upward while holding the tray 250, the disk 220 contacts an interference member 251. When the clamper 210 further moves upward (in a direction opposite to an arrow C), the balls 216, which serve as an elastic holding mechanism of the central hole, are displaced inward in the radial direction of the central hole, and disengage from the central hole. As a result, the disk 220 drops onto and is held by the tray 250, thus completing the disengagement from the clamper 210.
A case will be explained below wherein the second disk is loaded. FIG. 11 shows the second disk 231, which has a hub 232 consisting of a magnetic material at its central portion, and is loaded in a disk cartridge 230.
When the second disk 231 is loaded into the disk apparatus and the disk identification means (not shown) determines that the second disk is loaded, the control means (not shown) controls the clamper loading mechanism (not shown) to maintain the clamper 210 in the holding state (the clamper 210 is indicated by a broken line in FIG. 12).
The disk cartridge 230 is moved downward by the tray loading mechanism (not shown), and the shaft of the spindle motor 201 is inserted into the opening formed at the center of the lower surface of the cartridge 230 (a description of a shutter opening/closing mechanism for closing the opening of the disk cartridge, a cartridge holding mechanism, and the like will be omitted).
When the hub 232 approaches the magnet 205 arranged on the spindle motor 201, the hub consisting of a ferromagnetic material is attracted by the magnetic force of the magnet 205, and its central hole 232a is fitted on the rotation shaft 202, thus determining the radial position of the disk. At the same time, the clamp region on the lower surface of the disk 231 contacts and engages with the second support surface 204 of the spindle motor, thus determining the position, in the direction of the rotation shaft, of the disk.
In the state wherein the second support surface 204 is in tight contact with the clamp region of the second disk by the magnetic attraction force, the holding state of the second disk 231 on the spindle motor 201 is maintained.
Detachment of the second disk is realized in such a manner that the hub 232 is separated against the attraction force of the magnet 205 by moving the cartridge 230 upward with respect to the spindle motor 201 using the tray loading mechanism. The above embodiment adopts the arrangement described above, but the mode of the present invention is not limited to this.
For example, the elastic holding portion for holding the first disk on the clamper may be supported by an easily deformable elastic member such as a synthetic resin, and a contact portion to the central hole of the disk may be constituted by arranging roughly spherical members at the positions of the balls 216 to be free to move inward in the radial direction of the disk. The compression coil spring 218 may be replaced by any other elastic members, as long as it has a function of biasing the pressing member 216. Furthermore, the distal end portion 214 of the clamper 210 may be constituted by a combination of a non-magnetic member such as a synthetic resin and a ferromagnetic member arranged at only the distal end portion facing the magnet 205 of the spindle motor 201, or a synthetic resin member formed by containing ferromagnetic powder, as a means other than that constituted by only a ferromagnetic material.
The first support surface 203 formed on the spindle motor 201 need only be arranged at an arbitrary position between the rotation shaft 202 and the second support surface 204, and may be, e.g., the surface, facing the clamper, of the magnet 205. In this case, the contact surface between the first support surface 203 and the distal end portion 214 of the clamper 210 must be located at a position in the direction of the rotation shaft, where it does not interfere with the hub 232 of the second disk.
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A clamping mechanism for clamping both a mechanically clampable type of disk and a magnetically clampable type of disk includes a magnet provided on a turntable for clamping the magnetically clampable disk, and a fitting portion and a sub-turntable portion of a caddie for clamping the mechanically clampable disk. When the caddie is loaded on the apparatus, the sub-turntable is fixed on the turntable by the magnet.
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FIELD OF THE INVENTION
[0001] This invention relates to mowing machines for cutting grass and other vegetation, and more specifically to electromagnetic clutches for transmission of power from a lawn mower engine to mower blades.
BACKGROUND OF THE INVENTION
[0002] Electromagnetic clutches typically are used to transmit power from a lawn mower engine to two or more cutting blades mounted on spindles under a mower deck. The electromagnetic clutches are designed to engage very quickly to minimize clutch plate wear. However, a disadvantage of the sudden engagement is that engine speed may droop. As a result, the mower deck may vibrate and shake until the rotational speed of the blades and spindles increases sufficiently. Until the blades reach the desired speed, the belt or belts may slip on the pulleys mounted on the drive shaft and blade spindles.
[0003] Electromagnetic clutches for mower blades may be engaged by actuating a push button or toggle PTO switch. If the operator notices significant engine speed droop when actuating the PTO switch, he or she may then turn off the switch to disengage the clutch before the engine stalls, either before or shortly after clutch lockup. If the operator repeatedly flips the PTO switch to attempt re-engaging the clutch to mate up the engine to a stalled load, the useful life of the clutch will be greatly reduced.
[0004] A stalled load, or stall condition, may be a mower blade that is stuck against an obstruction on the ground under the mower deck, or a mower blade that encounters high resistance rotating through a build-up of grass clippings or debris on the undersurface of the deck. These and other stall conditions can significantly slow or stop rotation of rotary cutting blades. Attempts to engage and re-engage the mower blade clutch while a stall condition exists increases clutch wear.
[0005] In the past, attempts to address the mower blade clutch engagement problem have not been very effective or economical. One approach is to size the electromagnetic clutch with sufficient capacity to stall the engine without slipping the clutch, requiring a more costly clutch assembly. Another approach is to provide a clutch that allows the belt to slip significantly before the engine stalls. However, the belt may wear excessively before the operator notices the belt slipping or smells the belt burning, and then uses the PTO switch to disengage the clutch.
[0006] Soft engagement devices also exist for electromagnetic clutches to reduce sudden clutch engagement, by modulating the voltage applied to the electromagnetic coils of the clutch. The electronic modules allow the clutch plates to slip for a period, while reducing the engine droop and other undesirable characteristics of the hard start. However, the clutch may be susceptible to wear during use of a soft engagement device.
[0007] A system is needed to reduce wear to an electromagnetic clutch for transmission of power from a lawn mower engine to mower blades, and to prevent attempted repeated engagement of the clutch while a stall condition exists.
SUMMARY OF THE INVENTION
[0008] A stall detection system for mower blade clutch engagement includes a PTO switch that may be actuated to engage a mower blade to a power source, a sensor for sensing an operating condition of the power source or mower blade, and a microcontroller connected to the sensor and the PTO switch. The microcontroller determines if the operating condition from the sensor satisfies a predetermined criteria during an interval after engagement of the PTO switch, and de-actuates the PTO switch to disengage the mower blade from the power source if the operating condition fails to satisfy the criteria. The stall detection system reduces wear to an electromagnetic clutch for transmission of power to mower blades, and prevents attempted repeated engagement of the clutch while a stalled load or stall condition exists.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram of a stall detection system for mower blade clutch engagement according to a first embodiment of the invention.
[0010] FIG. 2 is a logic diagram of a stall detection system for mower blade clutch engagement according to a first embodiment of the invention.
[0011] FIG. 3 is a graph of engine rpm, spindle rpm, and PTO voltage in relation to time before and after actuation of a PTO switch, and clutch lockup, of a typical mower deck without a stall condition.
[0012] FIG. 4 is a pulse train diagram illustrating a sequence of pulses from an engine operating condition sensor of a mower that may be used to determine if a stall condition exists.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] In one embodiment, as shown in FIG. 1 , stall detection system 101 is provided for a counter-rotating, rear discharge/rear collection mower deck 103 . The mower deck may be used in a variety of different mowing vehicles or walk-behind mowers, and in a variety of different mower configurations. For example, one, two, or more decks may be attached to a vehicle. Mower deck 103 may be a two-chamber deck; i.e., with two cutting blades and spindles; and may be positioned at or adjacent the front, middle, or rear of the vehicle. However, in an alternative embodiment, the mower deck may have three or more chambers, each chamber having a cutting blade attached to a spindle.
[0014] In one embodiment, stall detection system 101 utilizes one or more sensors of operating conditions of a mower and provide input to microcontroller 119 in diagnostics control module 109 to determine if a stall condition exists during mower blade clutch engagement. The mower operating conditions are detected by the sensors to indicate if there is a stalled load, or stall condition, such as, but not limited to, obstructions on the ground under the mower deck, or build-up of grass clippings or debris on the undersurface of the deck. In general, stall conditions are operating conditions of the mower that significantly slow or stop rotation of rotary cutting blades.
[0015] The microcontroller may apply the input from one or more sensors to preprogrammed software logic that performs the following steps during a time period after operator actuation of PTO switch 133 . Initially, when the operator actuates PTO switch 133 to provide electric power to electric clutch coil 123 for engaging the mower blade clutch, the microcontroller compares the sensor input to one or more criteria to determine if a stall condition exists. The microcontroller performs the assessment or comparison before a stall condition brings engine 111 to a stop, and preferably before clutch lockup. Additionally, if the microcontroller determines a stall condition exists during mower blade clutch engagement, the microcontroller provides a signal to FET 125 to shut off power to electric clutch coil 123 , discontinuing engagement of the clutch before the engine stalls. Discontinued engagement preferably is done before clutch lockup, but alternatively the microcontroller may provide a signal to disengage the clutch shortly after lockup.
[0016] In one embodiment, if the microcontroller switches off power to the electric clutch coil due to a stall condition, the operator may actuate the PTO switch a second time in an attempt to engage the mower blade clutch. The second time the operator actuates the PTO switch, the microcontroller again determines if a stall condition exists, and switches off power to the electric clutch coil before the engine stops. The operator may actuate the PTO switch a third time and, if a stall condition exists, the microcontroller switches off power to the clutch coil before the engine stops.
[0017] In one embodiment, each time the microcontroller determines a stall condition exists and switches off power to the electric clutch coil, a counter is incremented. After the counter reaches a preselected number, such as three, the microcontroller shuts off electric power to the engine ignition or shuts off the fuel supply to bring the engine to a stop. As a result, if an operator attempts more than three engagements of the mower blade clutch but each time a stall condition is detected, the microcontroller provides a signal causing the engine to stop. Alternatively, the microcontroller may provide a warning signal to the operator or disable the electric clutch coil for a specified period if the operator attempts another engagement of the clutch after three detected stall conditions. If, however, the clutch engagement is successful during one of the three attempted engagements, the increment counter is set back to zero.
[0018] In one embodiment, the stall detection system 101 senses the rotational speed of a blade spindle of mower deck 103 . The spindle may have a first or upper end with a belt driven pulley attached thereto, and a second or lower end with a rotary cutting blade attached thereto for cutting grass. The spindle also may be equipped with a code wheel 105 . A code wheel tooth sensor 107 may be mounted on the mower deck adjacent the spindle to detect the rotational speed of the code wheel. The code wheel tooth sensor may be electrically connected to digital speed input 108 of diagnostics electronic module 109 . The code wheel tooth sensor may produce pulses that are indicative of the rotational speed of the spindle. The microcontroller determines if the rotational speed of the spindle meets one or more preselected criteria. For example, if the sensed rotational speed of the spindle does not increase to a preselected rpm (e.g., 1000 rpm) after a preselected time period (e.g., 0.5 second) after the operator actuates the PTO switch, the microcontroller may be programmed to determine that a stall condition exists before clutch lockup. Alternatively, if the sensed spindle does not accelerate sufficiently (e.g., increased rotational speed of at least 500 rpm per second), the microcontroller may determine that a stall condition exists, even after clutch lockup.
[0019] In a second embodiment, stall detection system 101 senses the rotational speed of internal combustion engine 111 or other power source. For example, the rotational speed of engine flywheel 113 may be sensed by flywheel tooth sensor 115 . The flywheel tooth sensor may be electrically connected to digital speed input 108 of the diagnostics electronic module. The flywheel tooth sensor may produce pulses indicative of the rotational speed of the engine. The microcontroller then determines if the rotational speed of the engine flywheel meets one or more preselected criteria. For example, if the sensed rotational speed of the engine decreases below a preselected rpm (e.g., 1000 rpm) during a preselected time period (e.g., 0.5 second) after the operator actuates the PTO switch, the microcontroller may be programmed to determine that a stall condition exists. Alternatively, if the engine decelerates too fast (e.g., a decrease of more than 2500 rpm) during a preselected time period (e.g., 0.5 second) after the operator actuates the PTO switch, the microcontroller also may determine a stall condition exists. Preferably, the preselected time period when a stall condition can be detected is before clutch lockup.
[0020] Additionally, in one embodiment, the microcontroller not only may determine if a stall condition exists before clutch lockup, but also if a stall condition exists shortly after clutch lockup, and then disengage the clutch. For example, if the engine does not increase to a preselected rpm (e.g., 1500 rpm) after a preselected time period (e.g., 1 second) after the operator actuates the PTO switch, the microcontroller may be programmed to determine that a stall condition exists. Alternatively, if the engine does not accelerate sufficiently (e.g., an increase of at least 250 rpm per second), the microcontroller may determine that a stall condition exists.
[0021] In a third embodiment, stall detection system 101 senses the rotational speed of alternator 117 . The alternator may be electrically connected to digital speed input 108 of the diagnostics electronic module, and may produce pulses similar to the engine speed sensor. The microcontroller determines if the rotational speed of the alternator satisfies one or more preselected criteria. The criteria may include those identified above for the engine. If the pulses from the alternator indicate the speed has decreased or decelerated more than a specified amount shortly after PTO switch actuation, the microcontroller may be programmed to determine that a stall condition exists.
[0022] In one embodiment, diagnostics control module 109 includes microcontroller 119 which receives digital electronic input signals from one or more of the sensors described above through digital speed input 108 . The microcontroller may be an 8 bit controller with “capture” capability that allows the microcontroller to accurately measure the time between pulses in a pulse train from an engine flywheel sensor, alternator coils, or a deck spindle sensor. The microcontroller provides an output to FET 125 which provides the appropriate power to the electric clutch coil to engage or disengage the electromagnetic clutch based on the digital input from one or more sensors.
[0023] In one embodiment, operator control and display 127 may include throttle control 112 which may be mechanically or electromechanically linked to the engine to increase or decrease the fuel supply to the engine and thereby increase or decrease engine speed. The operator control and display also may include hour meter and status display 131 which may be electrically connected to diagnostics electronic module 109 to provide cumulative running time of the engine and show if the PTO is presently engaged or disengaged. Additionally, the operator control and display may include PTO switch 133 which may be electrically connected to the diagnostics electronic module and may be used by the operator to initiate control logic for providing power to the electric clutch coil.
[0024] In one embodiment, control logic in microcontroller 119 may detect a stall condition, provide a signal through FET to automatically deactivate current through the clutch coil to disengage or discontinue engagement of the clutch, inform the operator of the stall condition, and shut down the engine through engine kill switch 110 after the operator attempts to engage the clutch repeatedly (e.g., more than three times) under a stall condition. Engine kill switch 110 may block ignition or fuel to the engine combustion chambers. Alternatively, instead of shutting down the engine after several sensed stall conditions, the microcontroller may trigger a warning on the operator control and display, and/or disable the clutch for a predetermined period of time, or cool down period. Clutch cool down timer 121 may specify the time period during which actuation of the PTO switch is blocked from energizing clutch coil 123 .
[0025] In one embodiment, as shown in FIG. 2 , control logic is shown in a flow diagram for an embodiment of the invention that senses engine speed to determine if a stall condition exists. The control logic starts in block 201 when the diagnostics control module of a mower is powered on. In block 202 , the microcontroller determines if the PTO switch is already on. If the PTO switch is already on, the logic returns to block 202 . If the PTO switch is off, the engine period is computed, and the rolling average of a fixed number (e.g., 100) of engine periods also may be computed.
[0026] Now referring to FIG. 4 , engine period is a time value which can be measured in microcontroller instruction executions, and the engine period for the nth period may be expressed as P En =t n −t (n-1) where t n is the time of the n th pulse and t (n-1) is the time of the immediately preceding pulse. When a pulse is seen by the microcontroller, the current value of the timer is captured and stored in a register. When the next capture event occurs, the period is the difference between the two time values, measured in units of microcontroller instruction executions. Measuring the period of successive pulses is the inverse of speed. Engine period may be converted using known constants to engine speed in units of rpm or Hertz, but is not necessary for executing the control logic of the invention.
[0027] Referring again to FIG. 2 , in block 204 , the microcontroller again determines if the PTO switch is already on. If the PTO switch is already on, the logic returns to block 203 . The microcontroller may execute the steps of blocks 201 - 204 , before entering the stall detection sequence in block 205 , even if the PTO switch is not actuated.
[0028] If the PTO switch is off, in block 205 the stall detection sequence is started, including starting the stall counter and stall timer. The stall timer assures the system senses for stall conditions only during a specified time period after the operator actuates the PTO switch. The stall counter counts the number of times a stall condition is detected following actuation of the PTO switch.
[0029] In block 206 , the latest engine period is measured. In block 207 , the change in engine period is calculated. The change in engine period of the nth period from the immediately preceding period may be expressed as dP E =P En −P E(n-1) . In block 208 , the microcontroller determines if the amount of change in engine period indicates an engine stall condition or not. The microcontroller may compare the change dP E to one or more preselected stored values. If the change in engine period indicates no stall condition, in block 209 the microcontroller checks if the stall detect timer has expired. The stall detect timer, which was started in block 205 , may run for a preselected interval (e.g., 3 seconds) after actuation of the PTO switch, during which time the microcontroller receives sensor information to determine if a stall condition exists. If the stall detect timer has expired, in block 210 the stall detection sequence is exited, in block 211 the stall detect counter and stall detect timer are cleared, and the logic returns to block 202 .
[0030] However, if the change in engine period indicates engine speed has dropped too sharply, in excess of the preselected amount, in block 212 the microcontroller provides a signal through FET 125 to shut off power to electric clutch coil 123 , disengaging the clutch. In block 213 , the stall detect counter is incremented by one. In block 214 , the microcontroller determines if the stall detect counter has reached a value greater than three. If it has not, the logic returns to block 203 . The operator then may elect to actuate the PTO switch again, in which case the logic reenters the stall detection sequence described above.
[0031] In block 214 , if the stall detect counter indicates a value greater than three, the microcontroller sends a signal to engine kill switch to shut off the engine ignition or fuel to stop the engine. Alternatively, or additionally, a warning signal may be provided to the operator control and display, or the electric clutch coil may be deactivated for a specified period of time.
[0032] Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
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A stall detection system for mower blade clutch engagement determines if there is a stall condition by sensing one or more operating conditions such as engine deceleration or blade spindle rotation. If a stall condition is detected, a microcontroller shuts off actuating current to the electric clutch coil and automatically disengages or discontinues engagement of the clutch. The microcontroller may also provide a signal to inform the operator of the stall condition, and prevent repeated activation of the clutch until the stall condition is corrected.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This continuation-in-part patent application claims priority to the continuation-in-part patent application having Ser. No. 12/214,007, filed Jun. 16, 2008; which claims priority to the non-provisional patent application having Ser. No. 10/905,827, filed Jan. 21, 2005, which is now U.S. Pat. No. 7,402,536.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to chair pads and, more particularly, to wood chair pads. Chair pads are used as a protective covering for a floor area on which a chair rests or some other furniture item. The chair pad is utilized to protect the underlying floor from damage due to wear and tear caused by the chair and/or the occupant of the chair moving about within the floor area on which the chair rests. A typical chair pad is made of plastic or other appropriate material that is semi flexible, but resilient enough such that when the chair pad is placed on the floor area a semi rigid surface is provided by the chair pad. The semi rigid surface makes it easier to move about in the floor area with a chair with wheels.
[0003] Most chair pads are a unitary one piece flattened body. Some chair pads as indicated are made of plastic. However others are made of a hardwood material to provide a better aesthetic appeal. Hardwood chair pads, however, are not flexible. These chair pads, particularly largely ones, are difficult to move about and very difficult to ship because of the special packaging required. Also, one alternative to hardwood is bamboo, which can also be utilized for a chair pad if processed like a hardwood.
[0004] Bamboo is a grass, which belongs to the sub-family Bambusoidae of the family Poaceae (Graminae). Bamboo occurs naturally on every industrialized and populated continent with the exception of Europe. There are over 1000 known species of bamboo plants. It is a durable and versatile material, which has been utilized by various cultures and civilizations for various applications. Bamboo has been an integral part of the cultural, social and economic traditions of many societies. There is a vast pool of knowledge and skills related to the processing and usage of bamboo, which has encouraged the use of bamboo for various applications.
[0005] Clumping bamboo can be widely grown in tropical climates. The trunk of the plant is called the “culm”. The culm is a wider at the trunk or bottom and narrows toward the top. In some varieties of bamboo the culm may grow 40 to 60 feet tall. Once established, bamboo plants can replenish themselves in two or three years. Each year a bamboo will put out several full length culms, which are generally hollow, in the form of a tube having “nodes”. There are other parts of the bamboo plant that can be utilized other than the culm, including commonly used parts of a bamboo such as branches and leaves, culm sheaths, buds and rhizomes. Some species are very fast growing at the rate of one metre per day, in the growing season.
[0006] As mention above, bamboo occurs naturally on most continents, mainly in the tropical areas of a given continent. Its natural habitat ranges in latitude from Korea and Japan to South Argentina. It has been reported that millions tons of bamboo are harvested each year, almost three-fifths of it in India and China. On known source of quality bamboo is found in the Anji Mountains of China.
[0007] Bamboo has many uses such as substituting commercially for wood, plastics, and composite materials in structural and product applications. There is a large diversity of species, many of which are available in India, which is the second largest source of bamboo in the world ranking only behind China. These grow naturally at heights ranging from sea level to over 3500. Most Indian bamboo is sympodial (clump forming); the singular exception is Phylostacchus bambuisodes , cultivated by the Apa Tani Tribe on the Ziro plateau in Arunachal Pradesh.
[0008] Bamboo has to undergo certain processing stages to convert them into boards/laminates. The green bamboo culms are converted into slivers/planks and then to boards. The boards are finally finished by surface coating. The common primary processing steps for making sliver/planks from green bamboo culms are 1. Cross Cutting; 2. Radial Splitting; 3. Internal Knot Removing & Two-sided Planing; 4. Four-sided Planing; and 5. forming slivers/planks. The common secondary processing steps for making board/laminate from sliver/planks are 1. Starch Removal & Anti-fungal Treatment; 2. Drying; 3. Resin Application; 4. Laying of Slivers/planks; 5. Hot Pressing & Curing; and 6. form laminates/Boards. The common surface coating and finishing stages are 1. Surface Sanding & Finishing; 2. Surface Coating with melamine/polyurethane; 3. Curing of Laminates; 4. Fine Sanding; 5. Evaluation of Surface Properties.
[0009] There are various types of bamboo flooring including tongue and groove and the type that need to be butted together. The lacquered flooring tiles are finished using wear resistant UV lacquer and the unlacquered flooring tiles need to be coated/waxed and polished after installation. The strength of bamboo boards can be better than common wood board for its special Hi-steam pressure process. The board has good water resistance for its shrinking and expanding rate. Its water-absorbing rate is better than wood and is further humidity resistant and smooth. It has been reported that the strength of 12 mm bamboo ply-board is equivalent to that of a 25 mm plywood board. There are also removable bamboo flooring covering having bamboo on one side and carpeting on the other side. Although this type of flooring have limited flexibility.
[0010] There are also various types of bamboo chair pads made of flat elongated planks or strips arranged side by side length wise and attached along abutting adjacent edges binding them together in a side by die arrangement. There is also usually a cloth or felt backing or some other fibrous materials bonded to the underside. The bamboo chair pad as with any other wood chair pad is rigid.
[0011] The bamboo material is very durable for chair pad application, however, the construction of many bamboo pads are rigid lacking the capability to flex or bend. A novel bamboo chair pad construction is needed.
SUMMARY OF THE INVENTION
[0012] The invention is a hard wood chair pad formed from multiple elongated bamboo planks that have been processed like hardwood flooring. The chair pad provides a substantially hardwood rigid surface but the pad can be rolled up like a chair pad for ease of transport and shipping. The hardwood planks have sufficient thickness such that when they are bonded to a backing in an adjacent side by side manner a substantially rigid surface is provided. The planks are not adjacent connected along their side edges, therefore the pad can be rolled for ease of transport.
[0013] The bamboo chair pad can be manufactured from 100% Anji Mountain bamboo from China. The bamboo is all treated with various protective coatings to add resistance to natural factors including water, sun and dirt. All bamboo chair pads are made from the harder portions of the bamboo trunk. (Some bamboo used for indoor purposes are manufactured from the softer fibers of the inside of the bamboo trunk). This portion of the bamboo trunk is not utilized for this invention. The bamboo utilized in the present invention is taken from the harder part of the bamboo trunk to assure maximum endurance and longevity. The lower trunk portion of the bamboo plant is harder and less porous.
[0014] The bamboo for the present invention is kiln dried to prevent warping and remove moisture that can cause future warping. Certain styles of bamboo are oxidized in a boiling vat of liquid to bring out different variations of color versus the common method of spray staining the bamboo planks to a particular color. The oxidation process also makes the bamboo less porous to moisture. In addition, the planks will be carbonized, in addition to being oxidized, in that boiling vat of liquid, which not only brings out coloration, but also removes any insects from the bamboo slats. A UV coating can also be applied to the bamboo planks. One embodiment of the inventions can have 7 coats of UV protection. The UV protection can be obtained by applying several layers of polyurethane coatings, and said coatings are applied a number of successive times and have exposure to UV heat bulbs, to add to their curing. The bamboo can be arranged with a series of planks lying next to one another and then assembled into a chair pad utilizing the same manufacturing processes and machinery utilized for bamboo rugs. The chair pad can then be rolled or pressed thereby compressing the entire layer of the chair pad.
[0015] During the assembly process a mesh sheet is placed on the bottom side of the chair pad. The mesh sheet can be made of nylon fibers. The mesh sheet is a fibrous mesh sheet, and it may be formed of one of synthetic and natural fibers, in its construction. A mastic layer is then placed over the nylon mesh sheet before a final layer of high density felt or sisal is applied, which can be preferably about approximately 2 mm in thickness. Then the chair pads are cut to the desired dimensions.
[0016] After the bamboo planks are kiln dried, so as to prevent warping, and after their oxidizing and being carbonized in a boiling vat of liquid, the bamboo planks may be placed in humidity measured drying room for multiple days to assure even drying and to maintain a consistent moisture level in the bamboo planks, as used. In other words, the drying room lowers the moisture content, and consistently keeps the moisture content of the planks uniformly at that lower level.
[0017] Certain bamboo that can be used in the manufacture of the present bamboo chairpad is oxidized and gives it an extra step in making the bamboo more impermeable to water, sunlight and dirt. Once the elongated bamboo planks have been processed, they are adjacently aligned lengthwise, and side by side. A fibrous strip, or multiple threads and/or a fibrous tape material can be applied to the underside to connect the bamboo planks. A fiber mesh sheet can then be applied and bonded to the underside to hold the strips together. Then the porous mating is bonded to the underside. The present inventions construction provides a product that is easily packaged, transported, shipped and moved about to the flexibility of the chair pad and ability to roll up.
[0018] These and other advantageous features of the present invention will be in part apparent and in part pointed out herein below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
[0020] FIG. 1 is a perspective view of the chair pad;
[0021] FIG. 2 is a perspective partial cut away view of the bamboo chair pad;
[0022] FIG. 3 is a perspective partial cut away exploded view of the chair pad layers;
[0023] FIG. 4 is a perspective partial cut away view of the chair pad illustrating its flexibility; and
[0024] FIG. 5 is a partial end view of the chair pad.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] According to the embodiment(s) of the present invention, various views are illustrated in FIGS. 1-5 and like reference numerals are being used consistently throughout to refer to like and corresponding parts of the invention for all of the various vies and figures of the drawing. Also, please note that the first digit(s) of the reference number for a given item or part of the invention should be correspond to the FIG. number in which the item or part is first identified.
[0026] One embodiment of the present invention comprising bamboo planks and a felt or sisal backing teaches a novel apparatus and method for a bamboo chair pad that is highly flexible along the plank seams for ease of rolling up.
[0027] The details of the invention and various embodiments can be better understood by referring to the figures of the drawing. Referring to FIG. 1 , a perspective view of the present chair pad invention is shown. The chair pad construction include a plurality of elongated bamboo planks 102 arranged lengthwise in a side by side manner where the long side edge of each planks can abut against the adjacent long side edge of the adjacent planks. The abutting relationship between the planks can form a seam 114 . The adjacent long side edges of adjacent planks can be unattached. The bamboo chair pad as shown is cut into a typical chair pad pattern outline that is a substantially rectangular outline with adjacent corner sections cut away. See the notched cutaway areas 104 and 106 .
[0028] Referring to FIG. 2 , the layers are shown assembled together forming the bamboo chair pad with a cut away revealing the liner layers. At least one fibrous tape strip extending orthogonally with respect to the lengthwise extension of the planks, see item 210 of FIG. 2 , can be utilized to connect the plank together in an abutting relationship with each adjacent plank in system forming a chair pad. The fibrous tape strip can have some adhesive or adhesion properties on at least one facing surface of the tape strip such that it bonds to the underside of the planks to connect the adjacent planks together from the underside of the plank. The strip can extend edge to edge of the bamboo layer portion 304 , see FIG. 3 .
[0029] The rug as described herein can be such that the bamboo slats or planks are kiln dried to prevent warping. The bamboo planks or slats may also be carbonized in a boiling vat of liquid for use for coloring of the bamboo. This has a tendency to take out the sugars from the bamboo which prevents deterioration, and allows for its colorations. The chair pad as described can also be such that the bamboo slats are oxidize in a boiling vat of liquid for coloring the bamboo rather than performing a staining process. The chair pad as described can have a resin layer that is a mastic resin layer for sealing and moisture resistance. The chair pad invention as described herein can be such that the bamboo slats or planks or made of the harder lower trunk portions of the bamboo plant. The loom fiber such that the fibrous tape strip, can be a poly resin fiber.
[0030] Also, in lieu of the tape embodiment, the planks can be connected by a series of substantially parallel fibers having adhesive properties extending orthogonally with respect to the lengthwise extension of the planks. The connecting tape strips or fibers 210 can also extend in a crossing angular fashion with respect to the lengthwise extension of the seams 114 . A fiber mesh sheet 206 can then be applied on the underside 308 of the bamboo layer portion 304 , see FIG. 3 . The mesh sheet further bonds the bamboo planks together. The chair pad as described herein can be such that the bamboo planks are kiln dried to prevent warping. The chair pad as described can also be such that the bamboo planks are oxidized in a boiling vat of liquid for coloring the bamboo rather than performing a staining process. The planks can vary in size; however one embodiment can have planks that are about approximately 5 mm thick and about approximately 5 cm wide. However, these dimensions can vary based on intended usage and preference. One embodiment of the chair pad can have planks with seven layers of UV protection and urethane coatings applied for mar and scuff resistance.
[0031] The chair pad, as described, can have a resin layer that is a mastic resin layer for sealing and moisture resistance. The chair pad invention as described herein can be such that the bamboo planks are made of the harder lower trunk portions of the bamboo plant. The fiber such as the fibrous tape strip can be a poly resin fiber. The fiber mesh sheet can also be a poly fiber mesh sheet.
[0032] All of these features provide significant flexibility. The construction of the layers bonded under the bamboo planks provides strength and durability as well as portability. The construction and the material contained in the construction described herein also provide substantial flexibility such that the chair pad can be easily rolled up.
[0033] Referring to FIG. 3 , an exploded partial cut away view of the present invention's bamboo chair pad layers is shown. The chair pad 100 is shown and with the layers revealed in an exploded view. The chair pad 100 comprises a plurality of elongated flat bamboo planks 102 arranged lengthwise and side by side and each plank connected in a substantially abutting relationship with respect to an adjacent plank forming seams 114 between adjacent planks. The connected planks form the bamboo chair pad layer portion 304 (bamboo layer). The abutting long edges of adjacent planks can be unattached along the seams 114 .
[0034] The adjacent planks can be connected to each other on the chair pad's bamboo layer underside 308 (the underside of the planks) by at least one fibrous tape strip extending orthogonally with respect to the lengthwise extension of the planks, see item 210 of FIG. 2 using the identified system for forming a chair pad. The loom fibrous tape strip can have some adhesive or adhesion properties on at least on facing surface of the tape strip such that it bonds to the underside of the planks to connect the adjacent planks together from the underside of the planks. The strip can extend orthogonally with respect to the lengthwise extension of the planks and can extend edge to edge of the bamboo layer portion 304 .
[0035] Also, the planks can be connected by a series of substantially parallel fibers having adhesive properties extending orthogonally with respect to the lengthwise extension of the planks. The connecting tape strips or fibers 210 can also extend in a crossing angular fashion with respect to the lengthwise extension of the seams 114 . A fiber mesh sheet 206 can then be applied on the underside 308 the bamboo layer portion 304 . The mesh sheet further bonds the bamboo planks together. One embodiment of the mesh sheet can be a nylon mesh sheet.
[0036] A resin material layer applied to the fiber mesh sheet underside 310 bonding the mesh sheet to the underside 308 of the chair pad's bamboo layer 304 . The resin material can be for example a mastic resin layer. The mastic resin layer will assist in providing a moisture seal for the underside of the chair pad for durability as well as bond the mesh sheet to the bamboo plank's underside 308 . Then a high density layer 312 of matted natural or man made fiber is applied to the mesh sheet underside 310 . The resin layer assists in bonding the high density fiber layer to the mesh underside. The high density layer can be moisture, mildew and skid resistant. The high density fiber layer can be made of matted sisal, felt, rubber, or polymer padding bonded under and to the resin material layer or the high density layer can be made of another appropriate fiber. One embodiment of the high density fiber layer can be about approximately 2 mm in thickness. However, the thickness of the high density fiber layer can vary significantly depending on the application and the environment for which the chair pad is to be used. Once the layers have been bonded, they can be pressed or rolled further compressing and bonding the layers together.
[0037] Referring to FIGS. 4 and 5 , a perspective partial cut away view of the chair pad illustrating its flexibility, and a partial end view of the chair pad is shown. The high density layer 312 , the mesh layer 206 , the tape 210 , and the bamboo plank layer 102 are all shown in these views. The adjacent long side edges 502 and 504 of the planks 102 are shown unattached along the seams 114 .
[0038] The various bamboo chair pad examples shown above illustrate a novel outdoor/indoor bamboo chair pad construction. A user of the present invention may choose any of the above bamboo chair pad construction embodiments, or an equivalent thereof, depending upon the desired application. In this regard, it is recognized that various forms of the subject outdoor/indoor bamboo chair pad could be utilized without departing from the spirit and scope of the present invention.
[0039] As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the spirit and scope of the present invention.
[0040] Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims.
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A bamboo Chair pad that can be manufactured from 100% Anji Mountain bamboo from China. The bamboo is all treated with various protective coatings to add resistance to natural factors including water, sun and dirt. All bamboo chair pads can be manufactured from the harder portions of the bamboo trunk. (Some bamboo is manufactured from the softer fibers of the inside of the bamboo trunk). This portion of the bamboo trunk is not utilized for this invention. The bamboo utilized in the present inventions is taken from the harder part of the bamboo trunk to assure maximum endurance and longevity. The lower trunk portion of the bamboo plant is harder and less porous.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is related to the following recently filed application U.S. patent application entitled WALL ANCHOR CONSTRUCTS AND SURFACE-MOUNTED ANCHORING SYSTEMS UTILIZING THE SAME.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to folded wall anchors and to surface-mounted anchoring systems employing the same, both of which are used in cavity wall constructs. More particularly, the invention relates to sheetmetal wall anchors and wire formative veneer ties that comprise positive interlocking components of the anchoring system. The system has application to seismic-resistant structures and to cavity walls having special requirements. The latter include high-strength requirements for jumbo brick and stone block veneers and high-span requirements for larger cavities with thick insulation.
2. Description of the Prior Art
In the late 1980's, surface-mounted wall anchors were developed by Hohmann & Barnard, Inc., patented under U.S. Pat. No. 4,598,518 of the first-named inventor hereof. The invention was commercialized under trademarks DW-10, DW-10-X, and DW-10-HS. These widely accepted building specialty products were designed primarily for dry-wall construction, but were also used with masonry backup walls. For seismic applications, it was common practice to use these wall anchor as part of the DW-10 Seismiclip interlock system which added a Byna-Tie wire formative, a Seismiclip snap-in device—described in U.S. Pat. No. 4,875,319 ('319), and a continuous wire reinforcement.
In the dry wall application, the surface-mounted wall anchor of the above-described system has pronged legs that pierce the insulation and the wall board and rest against the metal stud to provide mechanical stability in a four-point landing arrangement. The vertical slot of the wall anchor enables the mason to have the wire tie adjustably positioned along a pathway of up to 3.625-inch (max.)The interlock system served well and received high scores in testing and engineering evaluations which examined effects of various forces, particularly lateral forces, upon brick veneer masonry construction. However, under certain conditions, the system did not sufficiently maintain the integrity of the insulation.
The engineering evaluations further described the advantages of having a continuous wire embedded in the mortar joint of anchored veneer wythes. The seismic aspects of these investigations were reported in the inventor's '319 patent. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces resulted in the incorporation of a continuous wire reinforcement requirement in the Uniform Building Code provisions. The use of a continuous wire in masonry veneer walls has also been found to provide protection against problems arising from thermal expansion and contraction and to improve the uniformity of the distribution of lateral forces in the structure.
Shortly after the introduction of the pronged wall anchor, a seismic veneer anchor, which incorporated an L-shaped backplate, was introduced. This was formed from either 12- or 14-gauge sheetmetal and provided horizontally disposed openings in the arms thereof for pintle legs of the veneer anchor. In general, the pintle-receiving sheetmetal version of the Seismiclip interlock system served well, but in addition to the insulation integrity problem, installations were hampered by mortar buildup interfering with pintle leg insertion.
In the 1980's, an anchor for masonry veneer walls was developed and described in U.S. Pat. No. 4,764,069 by Reinwall et al., which patent is an improvement of the masonry veneer anchor of Lopez, U.S. Pat. No. 4,473,984. Here the anchors are keyed to elements that are installed using power-rotated drivers to deposit a mounting stud in a cementitious or masonry backup wall. Fittings are then attached to the stud which include an elongated eye and a wire tie therethrough for deposition in a bed joint of the outer wythe. It is instructive to note that pin-point loading—that is forces concentrated at substantially a single point—developed from this design configuration. Upon experiencing lateral forces over time, this resulted in the loosening of the stud.
Exemplary of the public sector building specification is that of the Energy Code Requirement, Boston, Mass. (see Chapter 13 of 780 CMR, Seventh Edition). This Code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities. Here, the emphasis is upon creating a building envelope that is designed and constructed with a continuous air barrier to control air leakage into or out of conditioned space adjacent the inner wythe.
As insulation became thicker, the tearing of insulation during installation of the pronged DW-10X wall anchor, see supra, became more prevalent. This occurred as the installer would fully insert one side of the wall anchor before seating the other side. The tearing would occur during the arcuate path of the insertion of the second leg. The gapping caused in the insulation permitted air and moisture to infiltrate through the insulation along the pathway formed by the tear. While the gapping was largely resolved by placing a self-sealing, dual-barrier polymeric membrane at the site of the legs and the mounting hardware, with increasing thickness in insulation, this patchwork became less desirable. The improvements hereinbelow in surface mounted wall anchors look toward greater retention of insulation integrity and less reliance on a patch.
Another prior art development occurred shortly after that of Reinwall/Lopez when Hatzinikolas and Pacholok of Fero Holding Ltd. introduced their sheetmetal masonry connector for a cavity wall. This device is described in U.S. Pat. Nos. 5,392,581 and 4,869,043. Here a sheetmetal plate connects to the side of a dry wall column and protrudes through the insulation into the cavity. A wire tie is threaded through a slot in the leading edge of the plate capturing an insulative plate thereunder and extending into a bed joint of the veneer. The underlying sheetmetal plate is highly thermally conductive, and the '581 patent describes lowering the thermal conductivity by foraminously structuring the plate. However, as there is no thermal break, a concomitant loss of the insulative integrity results.
In recent building codes for masonry structures a trend away from eye and pintle structures is seen in that newer codes require adjustable anchors be detailed to prevent disengagement. This has led to anchoring systems in which the open end of the veneer tie is embedded in the corresponding bed joint of the veneer and precludes disengagement by vertical displacement.
Another application for high-span anchoring systems is in the evolving technology of self-cooling buildings. Here, the cavity wall serves additionally as a plenum for delivering air from one area to another. While this technology has not seen wide application in the United States, the ability to size cavities to match air moving requirements for naturally ventilated buildings enable the architectural engineer to now consider cavity walls when designing structures in this environmentally favorable form.
In the past, the use of wire formatives have been limited by the mortar layer thicknesses which, in turn are dictated either by the new building specifications or by pre-existing conditions, e.g. matching during renovations or additions the existing mortar layer thickness. While arguments have been made for increasing the number of the fine-wire anchors per unit area of the facing layer, architects and architectural engineers have favored wire formative anchors of sturdier wire. On the other hand, contractors find that heavy wire anchors, with diameters approaching the mortar layer height specification, frequently result in misalignment. This led to the low-profile wall anchors of the inventors hereof as described in U.S. Pat. No. 6,279,283. However, the above-described technology did not address the adaption thereof to surface mounted devices.
In the course of prosecution of U.S. Pat. No. 4,598,518 (Hohmann '518) several patents, indicated by an asterisk on the tabulation below, became known to the inventors hereof and are acknowledged hereby. Thereafter and in preparing for this disclosure, the additional patents which became known to the inventors are discussed further as to the significance thereof:
Patent Inventor O. Cl. Issue Date 2,058,148* Hard 52/714 October 1936 2,966,705* Massey 52/714 January 1961 3,377,764 Storch Apr. 16, 1968 4,021,990* Schwalberg 52/714 May 10, 1977 4,305,239* Geraghty 52/713 December 1981 4,373,314 Allan Feb. 15, 1983 4,438,611* Bryant 52/410 March 1984 4,473,984 Lopez Oct. 2, 1984 4,598,518 Hohmann Jul. 8, 1986 4,869,038 Catani Sep. 26, 1989 4,875,319 Hohmann Oct. 24, 1989 5,063,722 Hohmann Nov. 12, 1991 5,392,581 Hatzinikolas et al. Feb. 28, 1995 5,408,798 Hohmann Apr. 25, 1995 5,456,052 Anderson et al. Oct. 10, 1995 5,816,008 Hohmann Oct. 15, 1998 6,209,281 Rice Apr. 3, 2001 6,279,283 Hohmann et al. Aug. 28, 2001 Foreign Patent Documents 279209* CH 52/714 March 1952 2069024* GB 52/714 August 1981
Note: Original classification provided for asterisked items only.
It is noted that with some exceptions these devices are generally descriptive of wire-to-wire anchors and wall ties and have various cooperative functional relationships with straight wire runs embedded in the inner and/or outer wythe.
U.S. Pat. No. 3,377,764—D. Storch—Issued Apr. 16, 1968
Discloses a bent wire, tie-type anchor for embedment in a facing exterior wythe engaging with a loop attached to a straight wire run in a backup interior wythe.
U.S. Pat. No. 4,021,990—B. J. Schwalberg—Issued May 10, 1977
Discloses a dry wall construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheet-metal anchor. Like Storch '764, the wall tie is embedded in the exterior wythe and is not attached to a straight wire run.
U.S. Pat. No. 4,373,314—J. A. Allan—Issued Feb. 15, 1983
Discloses a vertical angle iron with one leg adapted for attachment to a stud; and the other having elongated slots to accommodate wall ties. Insulation is applied between projecting vertical legs of adjacent angle irons with slots being spaced away from the stud to avoid the insulation.
U.S. Pat. No. 4,473,984—Lopez—Issued Oct. 2, 1984
Discloses a curtain-wall masonry anchor system wherein a wall tie is attached to the inner wythe by a self-tapping screw to a metal stud and to the outer wythe by embedment in a corresponding bed joint. The stud is applied through a hole cut into the insulation.
U.S. Pat. No. 4,869,038—M. J. Catani—Issued 091/26/89
Discloses a veneer wall anchor system having in the interior wythe a truss-type anchor, similar to Hala et al. '226, supra, but with horizontal sheetmetal extensions. The extensions are interlocked with bent wire pintle-type wall ties that are embedded within the exterior wythe.
U.S. Pat. No. 4,879,319—R. Hohmann—Issued Oct. 24, 1989
Discloses a seismic construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheet-metal anchor. Wall tie is distinguished over that of Schwalberg '990 and is clipped onto a straight wire run.
U.S. Pat. No. 5,392,581—Hatzinikolas et al.—Issued Feb. 28, 1995
Discloses a cavity-wall anchor having a conventional tie wire for mounting in the brick veneer and an L-shaped sheetmetal bracket for mounting vertically between side-by-side blocks and horizontally on atop a course of blocks. The bracket has a slit which is vertically disposed and protrudes into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 5,408,798—Hohmann—Issued Apr. 25, 1995
Discloses a seismic construction system for a cavity wall having a masonry anchor, a wall tie, and a facing anchor. Sealed eye wires extend into the cavity and wire wall ties are threaded therethrough with the open ends thereof embedded with a Hohmann '319 (see supra) clip in the mortar layer of the brick veneer.
U.S. Pat. No. 5,456,052—Anderson et al.—Issued Oct. 10, 1995
Discloses a two-part masonry brick tie, the first part being designed to be installed in the inner wythe and then, later when the brick veneer is erected to be interconnected by the second part. Both parts are constructed from sheetmetal and are arranged on substantially the same horizontal plane.
U.S. Pat. No. 5,816,008—Hohmann—Issued Oct. 15, 1998
Discloses a brick veneer anchor primarily for use with a cavity wall with a drywall inner wythe. The device combines an L-shaped plate for mounting on the metal stud of the drywall and extending into the cavity with a T-head bent stay. After interengagement with the L-shaped plate the free end of the bent stay is embedded in the corresponding bed joint of the veneer.
U.S. Pat. No. 6,209,281—Rice—Issued Apr. 3, 2001
Discloses a masonry anchor having a conventional tie wire for mounting in the brick veneer and sheetmetal bracket for mounting on the metal-stud-supported drywall. The bracket has a slit which is vertically disposed when the bracket is mounted on the metal stud and, in application, protrudes through the drywall into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 6,279,283—Hohmann et al.—Issued Aug. 28, 2001
Discloses a low-profile wall tie primarily for use in renovation construction where in order to match existing mortar height in the facing wythe a compressed wall tie is embedded in the bed joint of the brick veneer.
None of the above provide the high-strength, surface-mounted wall anchor or anchoring systems utilizing these devices of this invention. As will become clear in reviewing the disclosure which follows, the cavity wall structures benefit from the recent developments described herein that lead to solving the problems of insulation integrity, of interference from excess mortar, and of high-span applications. In the related Application, wire formatives are compressively reduced in height at the junctures between the wall reinforcements and the wall anchors and various techniques of forming junctures between embedded wire formatives are introduced.
SUMMARY
In general terms, the invention disclosed hereby is a surface mounted wall anchor and an anchoring system employing the same. The wall anchor is a folded sheetmetal device which is described herein as functioning with various wire formative veneer ties. The folded construction of the wall tie enables the junctures of the legs and the base of the wall anchor to be located inboard from the periphery of the wall anchor. During formation of the wall anchor, the outer surface of the enfolded leg and the underside of the base are caused to be coplanar. Upon installation, the coplanar elements act to seal the insertion point where the legs enter into the exterior layer of building materials on the inner wythe. This sealing effect precludes the penetration of air, moisture, and water vapor into the inner wythe structure.
In the first embodiment, the folded wall anchor is adapted from the earlier inventions of Schwalberg, U.S. Pat. No. 4,021,990 and of Hohmann, U.S. Pat. No. 4,875,319, see supra. Here it is seen that the double folded wall anchor (with legs moved inboard) together with a swaged veneer tie and wire reinforcement in the outer wythe creates a seismic construct of superior strength. This construct is applied to a dry wall inner wythe having thick insulation over wallboard, a larger-than-normal cavity, and a facing of jumbo brick.
In the second and third embodiments, the folded wall anchors are of the winged variety. The wings in the second embodiment are perforated and permit selectively adjustable positioning of the veneer tie. Here it is seen that a double folded wall anchor together with a standard box veneer tie is applied to a dry wall inner wythe having interior insulation and, thus, the wall anchor legs have only to penetrate the wallboard layer. In the third embodiment, the wings are slotted with a centrally disposed reinforcement bar. The folded wall anchor is paired with a canted, low-profile veneer anchor. The folded wall anchor is surface-mounted to a masonry block inner wythe having insulation on the exterior surface and a brick facing. The use of this innovative surface-mounted wall anchor in various applications addresses the problems of insulation integrity, thermal conductivity, and pin-point loading encountered in the previously discussed inventions.
OBJECTS AND FEATURES OF THE INVENTION
Accordingly, it is the primary object of the present invention to provide a new and novel anchoring systems for cavity walls, which systems are surface mountable to the backup wythe thereof.
It is another object of the present invention to provide a new and novel wall anchor mounted on the exterior surface of the wall board or the insulation layer and secured to the metal stud or standard framing member of a dry wall construction.
It is yet another object of the present invention to provide an anchoring system which is detailed to prevent disengagement under seismic or other severe environmental conditions.
It is still yet another object of the present invention to provide an anchoring system which is constructed to maintain insulation integrity by preventing air and water penetration.
It is a feature of the present invention that the folded wall anchor thereof has a coplanar baseplate for sealing against the leg insertion points.
It is another feature of the present invention that the legs of the folded wall anchor hereof have only point contact with the metal studs with substantially no resultant thermal conductivity.
It is yet another feature of the present invention that the bearing area between the wall anchor and the veneer tie spreads the forces thereacross and avoids pin-point loading.
Other objects and features of the invention will become apparent upon review of the drawing and the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWING
In the following drawing, the same parts in the various views are afforded the same reference designators.
FIG. 1 shows a first embodiment of this invention and is a perspective view of a surface-mounted anchoring system as applied to a cavity wall having a larger-than-normal cavity with an inner wythe of dry wall construction having thick insulation in the cavity and an outer wythe of brick;
FIG. 2 is a rear perspective view showing the folded wall anchor of the surface-mounted anchoring system of FIG. 1 ;
FIG. 3 is a perspective view of the surface-mounted anchoring system of FIG. 1 shown with a folded wall anchor, a swaged veneer tie threaded therethrough, and a reinforcing wire for seismic protection;
FIG. 4 is a cross sectional view of FIG. 1 which shows the relationship of the surface-mounted anchoring system of this invention to the dry wall construction and to the brick outer wythe;
FIG. 5 is a perspective view of a second embodiment of this invention showing a surface-mounted anchoring system for a cavity wall and is similar to FIG. 1 , but shows a dry wall construction with interior insulation and a wall anchor with perforated wings with a box veneer tie for insertion into the bed joints of the brick veneer facing wall;
FIG. 6 is a rear perspective view showing the folded wall anchor with perforated wings of FIG. 5 ;
FIG. 7 is a partial perspective view of FIG. 5 showing the relationship of the folded wall anchor with perforated wings and the corresponding veneer tie;
FIG. 8 is a perspective view of a third embodiment of this invention showing a surface-mounted anchoring system for a cavity wall and is similar to FIG. 1 , but shows a masonry block backup wall with a folded wall anchor with slotted wings and a low-profile, canted veneer tie.
FIG. 9 is a rear perspective view showing the wall anchor with slotted wings of FIG. 8 ; and,
FIG. 10 is a partial perspective view of FIG. 8 showing the relationship of the wall anchor and the corresponding veneer tie.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before entering into the detailed Description of the Preferred Embodiments, several terms which will be revisited later are defined. These terms are relevant to discussions of innovations introduced by the improvements of this disclosure that overcome the deficits of the prior art devices.
In the embodiments described hereinbelow, the inner wythe is provided with insulation. In the dry wall construction, this takes the form, in one embodiment, of exterior insulation disposed on the outer surface of the inner wythe and, in another embodiment, of interior insulation disposed between the metal columns of the inner wythe. In the masonry block backup wall construction, insulation is applied to the outer surface of the masonry block. Recently, building codes have required that after the anchoring system is installed and, prior to the inner wythe being closed up, that an inspection be made for insulation integrity to ensure that the insulation prevents infiltration of air and moisture. Here the term insulation integrity is used in the same sense as the building code in that, after the installation of the anchoring system, there is no change or interference with the insulative properties and concomitantly substantially no change in the air and moisture infiltration characteristics.
In a related sense, prior art sheetmetal anchors have formed a conductive bridge between the wall cavity and the interior of the building. Here the terms thermal conductivity and thermal conductivity analysis are used to examine this phenomenon and the metal-to-metal contacts across the inner wythe.
Anchoring systems for cavity walls are used to secure veneer facings to a building and overcome seismic and other forces, i.e. wind shear, etc. In the past, some systems have experienced failure because the forces have been concentrated at substantially a single point. Here, the term pin-point loading refers to an anchoring system wherein forces are concentrated at a single point.
In addition to that which occurs at the facing wythe, attention is further drawn to the construction at the exterior surface of the inner or backup wythe. Here there are two concerns namely, maximizing the strength of the securement of the surface-mounted wall anchor to the backup wall and, as previously discussed minimizing the interference of the anchoring system with the insulation. The first concern is addressed using appropriate fasteners such as, for mounting to masonry block, the properly sized concrete threaded anchors with expansion sleeves or concrete expansion bolts and, for mounting to metal, dry-wall studs, self-tapping screws. The latter concern is addressed by the flatness of the base of the surface-mounted, folded anchors covering the openings formed by the legs (the profile is seen in the cross-sectional drawing FIG. 3 ).
In the detailed description, the veneer reinforcements and the veneer anchors are wire formatives the wire used in the fabrication of veneer joint reinforcement conforms to the requirements of ASTM Standard Specification A-951-00, Table 1. For the purpose fo this application tensile strength tests and yield tests of veneer joint reinforcements are, where applicable, those denominated in ASTM A-951-00 Standard Specification for Masonry Joint Reinforcement.
Referring now to FIGS. 1 through 4 , the first embodiment shows a surface-mounted anchoring system suitable for seismic zone applications. This anchoring system, discussed in detail hereinbelow, has a folded wall anchor, an interengaging veneer tie, and a veneer (outer wythe) reinforcement and is surface mounted on a an externally insulated dry wall. For the first embodiment, a cavity wall having an insulative layer of 2.5 inches (approx and a total span of 3.5 inches (approx is chosen as exemplary. As the veneer being anchored is a jumbo brick veneer, the anchoring system includes extra vertical adjustment.
The surface-mounted anchoring system for cavity walls is referred to generally by the numeral 10 . A cavity wall structure 12 is shown having an inner wythe or dry wall backup 14 with sheetrock or wallboard 16 mounted on metal studs or columns 17 and an outer wythe or facing wall 18 of brick 20 construction. Between the inner wythe 14 and the outer wythe 18 , a cavity 22 is formed. The cavity 22 , which has a 3.5-inch span, has attached to the exterior surface 24 of the inner wythe 14 insulation in the form of insulating panels 26 . The insulation 26 is disposed on wallboard 16 . Seams 28 between adjacent panels of insulation 26 are substantially vertical and each aligns with the center of a column 17 .
Successive bed joints 30 and 32 are substantially planar and horizontally disposed and in accord with building standards are 0.375-inch (approx in height. Selective ones of bed joints 30 and 32 , which are formed between courses of bricks 20 , are constructed to receive therewithin the insertion portion of the anchoring system hereof. Being surface mounted onto the inner wythe, the anchoring system 10 is constructed cooperatively therewith, and as described in greater detail below, is configured to minimize air and moisture penetration around the wall anchor/inner wythe juncture.
For purposes of discussion, the cavity surface 24 of the inner wythe 14 contains a horizontal line or x-axis 34 and an intersecting vertical line or y-axis 36 . A horizontal line or z-axis 38 , normal to the xy-plane, passes through the coordinate origin formed by the intersecting x- and y-axes. A folded wall anchor 40 is shown which has a Pair of legs 42 which penetrate the wallboard 16 and insulation 26 . Folded wall anchor 40 is a stamped metal construct which is constructed for surface mounting on inner wythe 14 and for interconnection with veneer tie 44 .
The veneer tie 44 is adapted from one shown and described in Hohmann, U.S. Pat. No. 4,875,319, which patent is incorporated herein by reference. The veneer tie 44 is shown in FIG. 1 as being emplaced on a course of bricks 20 in preparation for embedment in the mortar of bed joint 30 . In this embodiment, the system includes a veneer or outer wythe reinforcement 46 , a wall anchor 40 and a veneer tie 44 . The veneer reinforcement 46 is constructed of a wire formative conforming to the joint reinforcement requirements of ASTM Standard Specification A-951-00, Table 1, see supra.
At intervals along a horizontal line surface 24 , folded wall anchors 40 are surface-mounted using mounting hardware 48 . The folded wall anchors 40 are positioned on surface 24 so that the longitudinal axis of a column 17 lies within the yz-plane formed by the longitudinal axes 50 and 52 of upper leg 54 and lower leg 56 , respectively. The legs 54 and 56 are folded, as best shown in FIG. 2 , so that the base surface 58 of the leg portions and the base surface 60 of the bail portion 62 are substantially coplanar and, when installed, lie in an xy-plane. Upon insertion in insulation 26 , the base surfaces 58 and 60 rest snugly against the opening formed thereby and serves to cover the opening precluding the passage of air and moisture therethrough. This construct maintains the insulation integrity. Optionally, a layer of Textroseal® sealant 63 , a thick multiply polyethylene/polymer-modified asphalt distributed by Hohmann & Barnard, Inc., Hauppauge, N.Y. 11788 may be applied under the base surfaces 58 and 60 for additional protection.
The dimensional relationship between wall anchor 40 and veneer tie 44 limits the axial movement of the construct. Each veneer tie 44 has a rear leg 64 opposite the bed-joint-deposited portion thereof which is formed continuous therewith. The slot or bail aperture 66 of bail 62 is constructed, in accordance with the building code requirements, to be within the predetermined dimensions to limit the z-axis 38 movement. The slot 66 is slightly larger horizontally than the diameter of the tie. The bail-receiving slot 66 is elongated vertically to accept a veneer tie threadedly therethrough and permit y-axis adjustment. The dimensional relationship of the rear leg 64 to the width of bail 62 limits the x-axis movement of the construct. For positive interengagement and to prevent disengagement under seismic conditions, the front legs 68 and 70 of veneer tie 44 and the reinforcement wire 46 are sealed in bed joint 30 forming a closed loop.
The folded wall anchor 40 is seen in more detail in FIGS. 2 through 4 . The legs 54 and 56 are folded 180° about end seams 72 and 74 , respectively, and then 90° at the inboard seams 76 and 78 , respectively, so as to extend parallel the one to the other. The legs 54 and 56 are dimensioned so that, upon installation, they extend through insulation panels 26 and wallboard 16 and the endpoints 80 thereof abut the metal studs 17 . Although only two-leg structures are shown, it is within the contemplation of this invention that more folded legs could be constructed with each leg terminating at an inboard seam and having the insertion point 82 of the insulation 26 covered by the wall anchor body. Because the legs 54 and 56 abut the studs 17 only at endpoints 80 , the thermal conductivity across the construct is minimal as the cross sectional metal-to-metal contact area is minimized. (There is virtually no heat transfer across the mounting hardware 48 because of the nonconductive washers thereof.)
The description which follows is a second embodiment of the surface-mounted anchoring system for cavity walls of this invention. For ease of comprehension, wherever possible similar parts use reference designators 100 units higher than those above. Thus, the veneer tie 144 of the second embodiment is analogous to the veneer tie 44 of the first embodiment. Referring now to FIGS. 5 through 7 , the second embodiment of the surface-mounted anchoring system is shown and is referred to generally by the numeral 110 . As in the first embodiment, a wall structure 112 is shown. The second embodiment has an inner wythe or backup wall 114 of a dry wall or a wallboard construct 116 on columns or studs 117 and an outer wythe or veneer 118 of facing stone 120 . The inner wythe 114 and the outer wythe 118 have a cavity 122 therebetween. Here, the anchoring system has a surface-mounted wall anchor with perforated wing portions or receptors for receiving the veneer tie portion of the anchoring system.
The anchoring system 110 is surface mounted to the exterior surface 124 of the inner wythe 114 . In this embodiment batts of insulation 126 are disposed between adjacent columns 117 . Successive bed joints 130 and 132 are substantially planar and horizontally disposed and in accord with building standards are 0.375-inch (approx.) in height. Selective ones of bed joints 130 and 132 , which are formed between courses of bricks 120 , are constructed to receive therewithin the insertion portion of the anchoring system construct hereof. Being surface mounted onto the inner wythe, the anchoring system 110 is constructed cooperatively therewith, and as described in greater detail below, is configured to penetrate through the wallboard at a covered insertion point.
For purposes of discussion, the cavity surface 124 of the inner wythe 114 contains a horizontal line or x-axis 134 and an intersecting vertical line or y-axis 136 . A horizontal line or z-axis 138 , normal to the xy-plane, passes through the coordinate origin formed by the intersecting x- and y-axes. A folded wall anchor 140 is shown which has a pair of legs 142 which penetrate the wallboard 116 . Folded wall anchor 140 is a stamped metal construct which is constructed for surface mounting on inner wythe 114 and for interconnection with veneer tie 144 .
The veneer tie 144 is a box Byna-Tie® device manufactured by Hohmann & Barnard, Inc., Hauppauge, N.Y. 11788. The veneer tie 144 is shown in FIG. 5 as being emplaced on a course of bricks 120 in preparation for embedment in the mortar of bed joint 130 . In this embodiment, the system includes a folded wall anchor 140 and a veneer tie 144 .
At intervals along a horizontal line on surface 124 , folded wall anchors 140 are surface-mounted using mounting hardware 148 with neoprene sealing washers. The folded wall anchors 140 are positioned on surface 124 so that the longitudinal axis of a column 117 lies within the yz-plane formed by the longitudinal axes 150 and 152 of upper leg 154 and lower leg 156 , respectively. The legs 154 and 156 are folded, as best shown in FIG. 6 , so that the base surface 158 of the leg portions and the intermediate base surface 160 are substantially coplanar and, when installed, lie in an xy-plane. Upon insertion in the wallboard 116 , the base surfaces 158 and 160 rest snugly against the opening formed thereby and serves to cover the opening precluding the passage of air and moisture therethrough, thereby maintaining the insulation integrity. It is within the contemplation of this invention that a coating of sealant or a layer of a polymeric compound—such as a closed-cell foam—be placed on base surfaces 158 and 160 for additional sealing.
In the second embodiment, perforated wing portions 162 therealong are bent upwardly (when viewing legs 142 as being bent downwardly) from intermediate base 160 for receiving veneer tie 144 therethrough. The dimensional relationship between wall anchor 140 and veneer tie 144 limits the axial movement of the construct. Each veneer tie 144 has a rear leg 164 opposite the bed-joint deposited portion thereof, which rear leg 164 is formed continuous therewith. The perforations 166 provide for selective adjustability and, unlike the other embodiments hereof, restrict the y-axis 136 movement of the anchored veneer. The opening of the perforation 166 of wing portions 162 is constructed to be within the predetermined dimensions to limit the z-axis 138 movement in accordance with the building code requirements. The perforation 166 is slightly larger horizontally than the diameter of the tie 144 . If y-axis 136 adjustability is desired, the perforations 166 may be elongated vertically. The dimensional relationship of the rear leg 164 to the width of spacing between wing portions 162 limits the x-axis movement of the construct. For positive interengagement, the front legs 168 and 170 of veneer tie 144 are sealed in bed joint 130 forming a closed loop.
The folded wall anchor 140 is seen in more detail in FIGS. 6 and 7 . The upper legs 154 and lower leg 156 are folded 180° about end seams 172 and 174 , respectively, and then 90° at the inboard seams 176 and 178 , respectively, so as to extend parallel the one to the other. The legs 154 and 156 are dimensioned so that, upon installation, they extend through wallboard 116 and the endpoints 180 thereof abut the metal studs 117 . Although only two leg structures are shown, it is within the contemplation of this invention that more folded legs could be constructed with each leg terminating at an inboard seam and having the insertion point 182 of the wallboard 116 covered by the wall anchor body. Because the legs 154 and 156 abut the studs 117 only at endpoints 180 , the thermal conductivity across the construct is minimal as the cross sectional metal-to-metal contact area is minimized. (There is virtually no heat transfer across the mounting hardware 148 because of the nonconductive washers thereof.
The description which follows is a third embodiment of the surface-mounted anchoring system for cavity walls of this invention. For ease of comprehension, wherever possible similar parts use reference designators 100 units higher than those above. Thus, the veneer tie 244 of the third embodiment is analogous to the veneer tie 144 of the second embodiment. Referring now to FIGS. 8 through 10 , the third embodiment of the surface-mounted anchoring system is shown and is referred to generally by the numeral 210 . As in the previous embodiments, a wall structure 212 is shown. Here, the third embodiment has an inner wythe or backup wall 214 of masonry block 216 and an outer wythe or veneer 218 of facing brick 220 . The inner wythe 214 and the outer wythe 218 have a cavity 222 therebetween. The anchoring system has a surface-mounted wall anchor with slotted wing portions or receptors for receiving the veneer tie portion of the anchoring system and a low-profile box tie.
The anchoring system 210 is surface mounted to the exterior surface 224 of the inner wythe 214 . In this embodiment panels of insulation 226 are disposed on the masonry block 216 . Successive bed joints 230 and 232 are substantially planar and horizontally disposed and in accord with building standards are 0.375-inch (approx.) in height. Selective ones of bed joints 230 and 232 , which are formed between courses of bricks 220 , are constructed to receive therewithin the insertion portion of the anchoring system construct hereof. Being surface mounted onto the inner wythe, the anchoring system 210 is constructed cooperatively therewith, and as described in greater detail below, is configured to penetrate through the insulation at a covered insertion point.
For purposes of discussion, the cavity surface 224 of the inner wythe 214 contains a horizontal line or x-axis 234 and an intersecting vertical line or y-axis 236 . A horizontal line or z-axis 238 , normal to the xy-plane, passes through the coordinate origin formed by the intersecting x- and y-axes. A folded wall anchor 240 is shown which has a pair of legs 242 which penetrate the insulation 226 . Folded wall anchor 240 is a stamped metal construct which is constructed for surface mounting on inner wythe 214 and for interconnection with veneer tie 244 .
The veneer tie 244 is adapted from the low-profile box Byna-Tie® device manufactured by Hohmann & Barnard, Inc., Hauppauge, N.Y. 11788 under U.S. Pat. No. 6,279,283. The veneer tie 244 is shown in FIG. 8 as being emplaced on a course of bricks 220 in preparation for embedment in the mortar of bed joint 230 . In this embodiment, the system includes a folded wall anchor 240 and a canted veneer tie 244 .
At intervals along a horizontal line surface 224 , folded wall anchors 240 are surface-mounted using masonry mounting hardware 248 . The folded wall anchors 240 are positioned on surface 224 at the intervals required by the applicable building codes. The upper legs 254 and lower leg 256 are folded, as best shown in FIG. 9 , so that the base surface 258 of the leg portions and the intermediate base surface 260 are substantially coplanar and, when installed, lie in an xy-plane. Upon insertion in insulation 226 , the base surfaces 258 and 260 rest snugly against the opening formed thereby and serves to cover the opening precluding the passage of air and moisture therethrough, thereby maintaining the insulation integrity. It is within the contemplation of this invention that a coating of sealant or a layer of a polymeric compound—such as a closed-cell foam—be placed on base surfaces 258 and 260 for additional sealing.
In the third embodiment, slotted wing portions 262 therealong are bent upwardly (when viewing legs 242 as being bent downwardly) from intermediate base 260 for receiving veneer tie 244 therethrough. The dimensional relationship between wall anchor 240 and veneer tie 244 limits the axial movement of the construct. Each veneer tie 244 has a rear leg 264 opposite the bed-joint deposited portion thereof, which rear leg 264 is formed continuous therewith. The slots 266 provide for adjustability and, unlike the second embodiment hereof, do not restrict the y-axis 236 movement of the anchored veneer. The opening of the slot 266 of wing portions 262 is constructed to be within the predetermined dimensions to limit the z-axis 238 movement in accordance with the building code requirements. The slots 266 are slightly larger horizontally than the diameter of the tie 244 . The dimensional relationship of the rear leg 264 to the width of spacing between wing portions 262 limits the x-axis movement of the construct. For positive interengagement, the front legs 268 and 270 of veneer tie 244 are sealed in bed joint 230 forming a closed loop.
The folded wall anchor 240 is seen in more detail in FIGS. 9 and 10 . The upper legs 254 and lower leg 256 are folded 180° about end seams 272 and 274 , respectively, and then 90° at the inboard seams 276 and 278 respectively, so as to extend parallel the one to the other. The legs 254 and 256 are dimensioned-so that, upon installation, they extend through insulation panels 226 and the endpoints 280 thereof abut the exterior surface 124 of masonry block 216 . Because the insertion point 282 into insulation 226 of the legs 254 and 256 is sealingly covered by the structure, the water and water vapor penetration into the backup wall is minimal. (There is virtually no heat transfer across the mounting hardware 248 because of the nonconductive washers thereof.)
In the veneer tie shown in FIGS. 8 and 10 , a bend is made at a point of inflection 284 . This configuring of the veneer tie 244 , compensates for the additional strengthening of wall anchor 240 at crossbar 286 . Thus, if the bed joint 230 is exactly coplanar with the strengthening crossbar 286 the bent veneer tie 244 facilitates the alignment thereof.
In the above description of the folded wall anchors of this invention various configurations are described and applications thereof in corresponding anchoring systems are provided. Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.
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A folded wall anchor and an anchoring system employing the same are disclosed. The anchor is a folded sheetmetal construct utilizable with various wire formative veneer ties. The folded wall tie enables the junctures of the legs and the base of the wall anchor to be located inboard from the periphery of the wall anchor. Upon installation with the surfaces of the enfolded leg and of the base coplanar, the leg insertion point is sealed thereby. This sealing precludes penetration of air, moisture, and water vapor into the wall structure. Various embodiments showing wall anchor configurations with suitable veneer ties are provided.
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BACKGROUND OF THE INVENTION
This invention has application in the field of printing wherein the combination of printing plates, such as credit cards, and multi-layered form assemblies are used. The printing assemblies generally have at least one sheet of paper and a carbon and a printing impression is made on a sheet by impressing a printing plate against a printing assembly. For reducing the distance between the printing pad and the printing anvil and for printing with the application of only a minimum of power, in prior devices a guide mechanism is used, comprising either a toggle joint system or a cam, by means of which the printing pad and the printing anvil can be directed toward one another in the vertical direction. After the printing pad and printing anvil are placed adjacent one another, an electromagnetic lifting mechanism exerts a very short printing impulse on the printing assembly to complete the printing operation.
The printing plates in such devices are horizontally supplied to and from the printing station, as is customary in prior art address printing machines which do not include electromagnetic printing means. It would be advantageous with regard to each operation to have an electromagnetic printing device of the type heretofor described which can be loaded and unloaded vertically, i.e. from the top of the printing device.
SUMMARY OF THE INVENTION
This invention is an improvement over the printing devices utilizing a combination of mechanical and electromagnet printing means. A particularly small, compact and therefore low-priced device has been attained, which, in spite of being manually operated, results in exact imprints which yield machine readable impressions.
For the obtaining of the above mentioned benefits, the printing device of the instant invention has the printing anvil, together with the armature plate connected to it, slidably mounted so as to be horizontally moved by hand from a first position, in which position the printing plate as well as the printing assembly can be vertically fed into the housing, to a forward position, in which the printing anvil is located directly in front of the printing pad and the interposed printing assembly. Additionally, when in the forward position, the armature is located directly in front of the magnet and therewith in the impulse readiness position.
It has been found advantageous in such printing devices to provide a capacitor which triggers the printing impulse through the electromagnet, when a switch is closed, to drive the armature plate, which is connected to the printing anvil. A handle extends through an aperture in the housing to enable the manual shifting of the armature plate and the printing anvil connected to it. A switch is located at the end of the path of this handle so as to be closed thereby. It has been found advantageous to mount this handle on the armature plate so as to be axially movable against the effect of a spring and to arrange the switch so as to be closable only after the spring has been compressed by the handle. In such a construction of the printing device, the printing anvil together with the plate can be moved into the printing position by hand under application of only a minimum of power, and a slight shifting of the handle compressing the associated spring is sufficient for actuating the switch and therefor triggering the printing impulse.
It has been found advantageous, with regard to ease of printing operation, to provide a holding frame for supporting the plates. The frame is pivotally mounted on the printing anvil so as to be pivoted about a lower horizontal axis in such way so that an opening slot for insertion or removal of the printing plates is provided when the frame is pivoted in the direction away from the printing anvil.
BRIEF DESCRIPTION OF THE DRAWINGS
Other details, advantages and characteristics of this invention will become apparent from the following description and by reference to the accompanying figures of the drawing wherein like numbers designate like parts:
FIG. 1 is a longitudinal, cross-sectional view of a printing device incorporating the features of the instant invention;
FIG. 2 is a circuit diagram of the electrical circuit provided to the printing device shown in FIG. 1;
FIG. 3 is a detailed view of a ratched device for feeding an ink ribbon within the printing device shown in FIG. 1;
FIGS. 4a and 4b are front views illustrating details of construction and taken along the line 4--4 of FIG. 1;
FIG. 4c is a plane view of a printing plate which may be used with the device shown in FIG 1;
FIGS. 5a and 5b are detailed longitudinal views illustrating the mode of holding a printing plate in the printing device shown in FIG. 1;
FIG. 6 is a longitudinal, cross-sectional view of an alternate embodiment of the printing device of FIG. 1;
FIG. 7 is an exploded, perspective view of the printing device shown in FIG. 6;
FIG. 8 is an exploded view of the ink ribbon box used in the printing device shown in FIGS. 1 and 6 and taken along the lines 8--8 of FIG. 7; and
FIG. 9 is another exploded view of the ink ribbon box of FIGS. 1 and 2 taken along the lines 9--9 of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the printing device illustrated therein has an elongated housing 1. Located within the housing 1 are two opposed electromagnets 2 with which an armature plate 3 is associated. This armature plate 3 is connected to a printing anvil 5 by means of a central rod 4. The central rod 4 slidably extends through a horizontal sleeve bearing 7 which is mounted in a vertical support 6 and which extends into the area between the electromagnets 2. A printing pad 9 is arranged in front of the printing anvil 5 and is mounted on a printing pad carrier 8. For this purpose, a vertical support 10 of the housing is arranged to be connected to the printing pad carrier 8 by means of a screw 11. Set screws 11', 11", allow exact adjustment of the printing pad 9 with respect to the printing anvil 5.
Located in the space between the printing anvil 5 and the printing pad 9 is an ink ribbon box 12 which contains an ink ribbon 12'. In order to drive the ink ribbon 12', receiving lugs 52 are mounted in the ink ribbon box 12 and one receiving lug is coupled with a ratchet wheel 39. The manner in which one of the receiving lugs 52 cooperates with a ratchet device will be described hereinafter in conjunction with FIG. 3.
Within an opening 18 between the ink ribbon box 12 and the printing pad 9, a document 13, or printing assembly, may be inserted from above. The printing assembly 13 will normally include at least one sheet of paper, and at least one carbon paper. Alternatively, an ink encapsulated self printing form may be used. The vertical movement of this printing assembly 13 is in the direction as indicated by the arrow shown in FIG. 1 and the assembly is supported by a spring loaded bar 14 mounted upon the vertical support 10. In this way, an exact positioning of the assembly 13 is assured.
Still referring to FIG. 1, a holding frame 16 serves as a support for a plate 15 and is pivotally mounted on a laterally extending pin 17 which is secured to the printing anvil 5. When the holding frame 16 is pivoted away from the printing anvil 5, it forms an upward opening slot for the insertion or removal of a plate 15 which corresponds to the insertion opening 18 at the top of the housing 1. The holding frame 16 has an L-shaped wall 23 for laterally engaging the plate 15 and supporting the same at its bottom edge. These walls 23 terminate at their upper ends into struts 19 which are generally perpendicular to the vertical support 6. These side walls 23 of the holding frame 16 extend along both sides of the printing anvil 5 and are operatively connected therewith through the struts 19 and traversely extending members 20 which are adjacent the vertical support 6. The traverse members 20 limit the extent of pivotal movement by the frame 16 through engagement with the printing anvil 5 as can be seen in FIG. 7.
As can be seen in FIGS. 5a and 5b, a spring 21 is arranged between each traverse member 20 and the printing anvil 5 and is mounted within a bore of the printing anvil 5. In the position of the printing anvil 5, with regard to the vertical support 6, as illustrated in the FIGS. 5a and 5b the traverse members 20 engage the printing anvil 5. Consequently, the spring 21 is compressed and the holding frame 16 pivoted around the lower horizontal pins 17 to form an opening slot for the insertion or removal of the plate 15.
As can be seen in FIG. 4c, each printing plate 15 is provided at its bottom edge with a bevel 22. A corresponding limiting pin 22' is arranged at the lower part of the frame 16 and together with the bevel 22, assures an exact positioning of the plate 15. As illustrated in FIGS. 4a and 5a, the plate 15 engages the lower portion of wall 23 of the frame 16 only if the bevel 22 of the plate 15 is in alignment with the limiting pin 22'. In the case where the plate 15 is incorrectly inserted into the holding frame 16, as shown in the FIGS. 4b and 5b, i.e. turned 180 degrees, one of the corners of the plate abuts the limiting pin 22' and the plate is suspended above the holding frame 16. Forward movement of the printing anvil 5 in the direction as indicated by the arrow shown in the FIGS. 4d or 5b is prevented by the presence of a projection 24 which extends from the housing. The upper edge of the plate 15 would be engaged by the projection 24 if the plate is not properly seated within the frame 16.
The central rod 4 is arranged in such a manner that the armature plate 3 will be located directly in front of the electromagnets 2 when the printing anvil 5, together with the plate 15, is moved into virtual engagement with the printing pad 9. In order to be moved manually, under application of only a minimum of power, into the position as indicated by the dotted lines illustrated in FIG. 1, the armature plate 3 is provided with a handle 26 which extends outwardly through an opening 25 of the housing 1. A switch 27 is arranged in the path of movement of this handle 26, the switch preferably being a mercury switch.
As is shown in FIG 2, the switch 27 is connected through the electromagnets 2 to a discharging circuit having a capacitor 28 (not shown in FIG. 1) which is charged by a source of power through a switch 29, a resistor 30 and a rectifier 31. The handle 26 is axially and slidably mounted on the armature plate 3 so as to be moved against the effect of the force of a spring 32 which holds the handle within the armature plate. When the handle, together with the armature plate 3, the central rod 4, and the printing anvil 5, has been moved into the position as illustrated by the dotted lines in FIG. 1, further pushing on the handle 26 causes a compression of the spring 32 and subsequently the closing of the switch 27 which is arranged in the path of movement of the handle 26. The closing of the switch causes the discharging of the capacitor, thereby enabling the electromagnets 2. This will result in the printing anvil 5 being impacted against the printing pad 9 to complete the printing operation.
The unit comprising the armature plate 3, the central rod 4 and the printing anvil 5 is connected to a horizontally extending push rod 33 (shown in FIG. 3) which actuates a ratchet device associated with the ink ribbon box 12. The push rod 33 is slidably received within a portion 34 of the housing in such a manner that a longitudinal deviation is prevented. The push rod 33 is provided at its outer end with a pin 35 which extends through an inclined slotted hole 36 of an engaging member 37. This engaging member 37 is vertically guided by pins 37' which are supported by the housing 11 and is provided with a leaf spring 38 which engages a ratchet wheel 39 mounted on a lug 52 of the ink ribbon box 12. A second leaf spring 41 is supported by the housing 11 and prevents reverse rotation of the ratchet wheel 39 in the direction as indicated by the arrow illustrated in FIG. 3.
From the aforementioned description it will be appreciated that a printing device according to this invention is not only characterized by small and inexpensive construction, which is moreover easy to operate, but will produce only a minimum of noise. Additionally, sets of assemblies with different thicknesses can be printed without an adjustment of the force of impression. Furthermore, the imprints will be obtained on predetermined areas of the assemblies, based on the one hand on the vertical arrangement of the plate holding device, thereby resulting in an automatic support of the plates after they have been inserted in the holding frame of the printing anvil, and on the other hand on the precise support of the forms on the spring loaded bar 14. Accurate and uniform machine readable impressions can be attained by using an ink ribbon box, which use eliminates smudging of the fingers of the operator. Appropriately, the ink ribbon box 12 may be made out of a transparent material so that a mark placed near the end of the ink ribbon 12' can be seen by the operator.
An alternate embodiment is shown in FIGS. 6 and 7. The ink ribbon box 12 and printing assembly 13 are insertable from the top into the interior of the housing 11 between the printing anvil 5 and the printing pad 9. Arranged in the gap between the printing anvil 5 and the printing pad 9 are the ink ribbon box and an elastic mask 42. The mask 42 is arranged between the printing pad 9 and the ink ribbon box 12. The assembly 13, moreover, is insertable through the opening 19, in the direction of the arrow, between the mask 42 and the printing pad 9. In order to determine the exact printing position of the assembly 13, the mask 42 is provided at its lower end with a flange 43 which extends under the printing pad 9.
The ink ribbon box 12 can be inserted in the device from the top in the same manner as the assembly 13 and the plate 15 (compare the arrows in FIG. 6). The inserting movement of the ink ribbon box 12 is limited therewith by means of a trough 44 which is disposed in the housing and provided with conically extending walls 44'. The opening 18 of the housing 1 receives a depending member 24 which is shaped so as to form an upper supporting means for the ink ribbon box 12. The ink ribbon box 12 is kept in engagement to this supporting means 24 by means of the mask 42. The mask 42 is provided with a bending portion 45 at its free end which engages the ink ribbon to form a suitable insertion opening for the assembly 13. FIG. 7 shows in an exploded view the essential arrangement of the respective parts. A bottom flange 43 of the mask 42 rests on a supporting bar 46 and a spring 47 acts on the mask in the direction of the ink ribbon box 12. The bottom flange 43 is formed at an angle of more than ninety degrees. The mask is made of an elastic material, as, for instance, bronze sheet metal. The top of the mask 42 is provided with a bent portion 45, which engages the ink ribbon box 12 and may extend into a slot in the upper cylinder 50 of the ink ribbon box. The mask 42 is furthermore provided with two apertures 48 and 49 of which the first aperture 48 enables the printing of a printing block which is stationarily mounted in the device and contains standard data thereon. The other aperture 49 enables the printing of the data of the plate 15.
From the FIGS. 8 and 9 details of the ink ribbon box 12 and its guidance and support within the trough 44 can be seen. The ink ribbon box 12 has two cylinders 50 and 50' extending parallel to each other in which the respective rolls 51 of ink ribbon are received. The receptive rolls 5' are disposed about the receiving lugs 52 which extend outwardly through the cylinders 50 and 50' and of which at least one is provided with radial notches 53 for feeding the ink ribbon 12' by engagement with the ratchet wheel 39. The cylinders 50 and 50' are connected to each other through flanges 54 and 55 which are formed as U-shaped bars with legs that extend outwardly, i.e. in the direction away from the cylinders 50 and 50'. The side walls 44' and 44" of the trough 44 extend upwardly and are provided with guide grooves 56 which engage the U-shaped bars of the flanges 54 and 55. The flanges 54 and 55 are staggered i.e. one of the vertical flanges is arranged on the side of the plane determined by the cylinder axis which face the mask 42 and the other on that side of the plane which faces the printing anvil 5.
The housing of the ink ribbon box 12 may be formed of two identical parts to reduce the costs for manufacturing. The ink ribbon box 12, as indicated previously, may be made out of transparent material, so that the approach of the end of the ink ribbon 50 can be detected. Instead of the transparent material, metal can be used for the manufacturing of the ink ribbon box 12. In this case, the upper cylinder 50 is provided with a window 57 which enables the operator to detect the end of the ink ribbon 12'.
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This invention relates to a relatively small printing device for printing onto a printing assembly of the kind having at least one form and an ink transferring ribbon associated with it. The printing device is top loading and includes a flat printing pad and a printing anvil serving as a support for a printing plate, such as a credit card, and for the printing assembly. Also included is an electromagnetic impulse device which has at least one electromagnet and an armature plate connected to the printing anvil and by means of which a short impression impulse is exerted after the distance between the printing pad and the printing anvil has manually been reduced to virtually the distance corresponding to the thickness of the plate and the printing assembly.
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SUMMARY OF THE INVENTION
This invention relates to a new and distinct Lantana camara cultivar which is outstanding because of its very compact growth habit, strong tendency to self branching, dramatic multi-colored, continuous bloom display, dense forest green leaves, and tendency to set seed infrequently; and was primarily selected for these characteristics. This selection was made from a specially designed Lantana hybridizing program with said hybrid cultivars being planted and grown in Grain Valley, Mo.
ORIGIN AND ASEXUAL REPRODUCTION
Asexual reproduction of this cultivar by tip cuttings was directed by me, such reproduction establishing that the plant does in fact maintain the characteristics described, in successive generations.
It should be noted that the plant was initially selected from a Lantana planting being grown near Grain Valley, Mo. in a cultivated area and has since been reproduced by tip cuttings in the vicinity of Grain Valley, Mo. with the new and distinct characteristics stated herein, found to be maintained through successive generations as before recited.
Lantana camara is native to the subtropics and tropical North and South America and are woody ornamentals which are not cold hardy North of USDA horticulture Zone 9. the roughish leaves range from yellow-green to green to blue-green and the two basic growth forms are mounding and trailing (weeping). Bloom color usually includes yellow, white, cream, pink, or orange.
The cultivar of Lantana camara `Robcomplan` may further be described as having a number of distinctive characteristics which are enumerated in the succeeding specific description but broadly stated as comprising a very compact growth habit of only 8"-12" (in height and width) in one season, a strong tendency to self branching, a multi-colored bloom display which transitions from yellow (PMS#109) to a sienna tone (PMS#157) and orange (PMS#172), then to fushia pink (PMS#205), dense forest-green (PMS#343) leaves with blue overtones, and reduced tendency to set seed. The continuous color display begins blooming at 6-7 weeks after cuttings are made, or 4 weeks after potting. Almost no pinching is needed due to this cultivar's tendency to self-branching.
I have chosen to identify this new cultivar as Lantana camara `Robcomplan`. It is possible that other identification will be adopted in the trade, but the name selected will serve for the purposes hereof.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying photographs show as nearly true as it is reasonably possible to make the same, in color illustrations of this character, typical leaves and flowers of the new variety. The photographic drawings illustrate the flower form, the distinctive color transitions of the florets, and the very compact growth habit when compared to the comparison plant.
FIG. 1 illustrates the bloom cluster with varying maturity of the florets (to display the color range as well as possible).
FIG. 2 illustrates the compact growth habit of the mature plant as distinguished from a mature comparison plant.
DETAILED DESCRIPTION
In order to more specifically identify the cultivar, descriptive details are set forth hereinafter, along with related aspects of the plant which serve to distinguish the same, all colors being noted as compared with the Pantone Matching System (PMS). The measurements and colors were recorded from mature plants grown in the vicinity of Grain Valley, Mo.
Parentage:
Seed parent.--Lantana camara `Confetti` (in controlled open pollination).
Pollen parent.--Unknown.
Propagation: Asexual reproduction by tip cuttings started near Grain Valley, Mo.
PLANT DESCRIPTIONS
Inflorescence and reproductive parts: The inflorescence is a flat topped round cluster of 25-30 florets. The individual clusters are determinate and arise from the leaf axils. Each individual floret is slightly un-symmetrical with a bilateral symmetry and is subtended by a single bract. The perianth consist of: Calyx (5 united petals) and the Corolla (5 united petals with narrow tube). The flowers are zygomorphic, hermaphroditic, and have 4 introse stamens which are didynamous.
The ovary is superior, the style is terminal, and the stigma is lobed. The ovary is 2 locular, but is divided into 4 loculi by a false septum in each loculus. The placentation is axile with 2 ovules per carpel.
The fruit classification is drupe and potentially contains 2 seeds. When fruit forms, it is green (PMS#363); then matures through a deep purple (PMS#533) to a near black (PMS#532)
Inflorescence dimensions:
Bloom cluster.--11/2" in diameter.
Single floret.--1/4".
Pedicle length.--1.1".
Corolla tube.--3/8".
Inflorescence colors:
Buds.--Salmon-pink(PMS#163).
First opening.--bright yellow (PMS#109).
Transitions through.--Sienna (PMS#157) and Orange (PMS#172).
Maturity.--Fushia pink (PMS#205).
Tube.--Pink in all stages (PMS#212).
Developmental pattern: First flowers develop in a circular pattern on the periphery of the inflorescence.
Leaves and stems.--Leaf shape: Ovate. Leaf margins: Serrate. Leaf tip and Base: Acute. Leaf veins: Pinnate. Leaf surface: Rough due to bristly hairs. Leaf arrangement: Opposite. Leaf color: Immature leaves are Forest Green (PMS#349) and mature leaves are Blue Green (PMS#343). Leaf size: Length 2". Petiole: 1/2". Width: 11/4". Stem: Square in youth becoming round and woody with age.
Roots.--highly branched and fibrous
Flowering time.--The color display begins blooming at 6-7 weeks after cuttings are made, or 4 weeks after potting, and continue until temperatures drop below 45 degrees Fahrenheit.
Disases.--No unusual susceptibility to diseases noted to date.
Insects.--Typical of this plant genius, white flies can be attracted to Lantana. There are no other insect problems known at this time.
GENERAL OBSERVATIONS
Lantana camara `Robcomplan`, with its dwarf and very compact growth habit is ideal for the smaller garden and landscape designs and the patio/pot culture trend. The lack of need to pinch for compact growth and the self-branching quality is a very time saving feature for the home gardener.
For the purpose of ornamental horticulture in our present living environments which include smaller yards and patio gardening, Lantana camara plant "Robcomplan" is ideal due to several characteristics:
A. It is an excellent plant for mass plantings, low borders, hanging baskets or floral specimen standards. Lantana camara `Robcomplan` will produce a continuous display of bright, multiple colors in the hot summer sun when other color has disappeared.
B. Self-branching is spontaneous, so almost no pinching is necessary. This growth habit, atypical in lantanas, produces a full compact display plant with little care or attention on the part of the gardener.
C. The leaves are smaller and more closely arranged than other Lantanas, which enhances the "compacta" display. It forms a compact mound 12"×12" in one season. It's very compact growth habit with small leaf size, short internode spacing, and tendency toward self-branching places "Robcomplan" in a category all its own, as this "compact habit" is not typical for any other Lantana in our awareness.
D. Lantana camara `Robcomplan` has a reduced tendency to set seed, therefore the inflorescence gives a longer display of color to the garden.
COMPARISON TO KNOWN VARIETIES
Lantana camara plant `Robcomplan` is similar to Lantana camara Confetti` in color. The inflorescence form and color presentations of these two cultivars are similar. There are no Lantanas in the trade that are a close comparison to "Robcomplan" in reference to its very compact growth habit, short internode spacing, and strong tendency to self branching. For Example: In one growing season of four months, `Confetti` forms a loose, open mound of 24"×24" with internode spacing of 11/2"-21/2". During this same growing period, `Robcomplan`"forms a dense, compact mound of 12"×12" with internode spacing of 3/4"-1".
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A new cultivar of Lantana is provided. The very compact growth habit with short internode spacing and strong tendency to self branching, with a continuous multi-colored bloom display, a reduced tendency to set seed, and dense rich forest green leaves providing a cultivar well suite for mass plantings, low borders, hanging baskets or floral specimens.
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BACKGROUND OF THE INVENTION
This invention relates to a heat recovery apparatus. A heat recovery apparatus may comprise a heat transfer space having a gas inlet and a gas outlet and in which at least two separate heat exchangers are arranged successively in the gas flow direction, as well as at least two separate heat transfer medium flow circuits. This kind of heat transfer apparatus provides advantageous heat transfer from a gas flow containing impurities.
The invention relates also to a method of operating a heat recovery apparatus, which method is effective to minimize fouling in a the heat recovery apparatus.
Utilization of heat recovery in order to recover energy from hot gases is commonly known and is beneficial. However, hot gases typically contain various impurities, the nature of which depends on the origin of the hot gases. For example a considerable amount of hot gas is generated in operation of a heat engine and the combustion gases contain various impurities, for example soot and condensable components such as hydrocarbons, depending on the fuel used in the engine.
U.S. Pat. No. 4,869,209 shows an automatic programmable cleaning system for heat exchange tubes of a waste heat boiler. For removing deposits from surfaces of the heat exchange tubes, it is suggested to spray water intermittently into the hot gas flow, whereby the soot that is removed is carried along with the exhaust gases out of the boiler. However, this kind of method is not suitable for general use. Further, evaporating the water consumes the energy of the gas, and the water consumption and the need for maintenance also affects the serviceability of the method.
It is of great importance that the heat transfer surfaces of the exhaust gas boiler of a combustion engine should be clean, in order to maintain efficiency, but it has been observed that these boilers tend to foul rapidly. In connection with state of the art combustion engines, and specifically with installations in which the combustion gases contain condensable components, for example hydrocarbons, as may be the case with gas engines, it may be necessary to clean the heat transfer surfaces as frequently as every 500 hours. Specifically, when the heat is recovered at different temperature levels, and condensation takes place especially in the last heat transfer stage on heat exchanger surfaces at lower temperatures, the efficiency of heat transfer decreases rapidly. In this kind of installation, the cleaning of the heat exchanger operating at lower temperature is accomplished in practice by emptying the heat exchangers, whereby its temperature may rise. This causes the condensable components in question to become soft (or melt) and drain down away from heat exchanger surfaces. However, this procedure may decrease the efficiency of heat recovery because during the cleaning operation, which may take approximately 8 hours, heat is not recovered by the heat exchanger in question. Further, the need to empty the heat exchanger may in some cases impose demands with respect to its material and construction, specifically due to the fact that being uncooled, its temperature may rise to a higher level than would be desirable. In that case also there is a risk of boiler fire.
In order to maintain the efficiency of heat recovery at an adequately high level and generally to maintain the equipment in an optimal operating state, the heat transfer surfaces must be kept clean by regular cleansing. Various methods and devices for this purpose are known from the prior art, but they still include many restrictions and may be inadequate with respect to their operation.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a heat recovery apparatus and method, by means of which it is possible to improve the state of the art and minimize the before mentioned and other problems of the prior art.
In an embodiment of the invention, the heat recovery apparatus comprises a heat transfer space having a gas inlet and a gas outlet and in which at least two separate heat exchangers have been provided successively in the gas flow direction, as well as at least two separate heat transfer circuits. The apparatus also comprises means for altering the direction of gas flow in the heat transfer apace and mean; for connecting each heat transfer circuit selectively to either of the at least two separate heat exchangers. This embodiment is specifically suitable for heat recovery from gases containing sticky, adhesive components, such as condensable hydrocarbons.
In this case, for example in connection with a gas engine operating in accordance with the Otto cycle, when the heat transfer circuits are operating at different temperature levels, such that thee temperature level of the gas before entering a heat exchanger connected to a first heat transfer circuit is typically 350-450° C. and after a heat exchanger connected to a second heat transfer circuit is typically 180-200° C., and as the heat transfer circuits operate typically at temperature level of, on average 60—100° C., it is possible to provide an arrangement in which, after the heat transfer surfaces have become fouled, specifically through condensation of hydrocarbons, to an excessive level, or otherwise when desired, the mode of operation of the apparatus may be altered as will be described in following.
The heat recovery apparatus in accordance with the invention preferably includes a heat transfer space, which comprises two parallel flow ducts, each of which contains at least one heat exchanger and which flow ducts abut at their other ends on a common space.
The present invention provides distinct benefits compared to the prior art. Firstly, the method is very effective compared for example to cleaning by water, which does not have much effect on deposits formed by condensed hydrocarbons. Additionally the cleaning of the heat transfer surfaces is done during the normal operation, whereby there is substantially no interference with the heat recovery. Further, there are no heat losses due to evaporation of cleaning water. Thus, by means of the present invention the heat exchangers can be maintained especially clean, since the change of the mode of the operation may be done always according to the need without impairing the operation. Additionally the present invention does not consume any additional agent for cleaning and also wearing of parts is minimized.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is described, by way of example, with reference to the attached drawings, in which:
FIG. 1 shows diagrammatically an apparatus in accordance with the present invention,
FIG. 2 shows schematically an apparatus in accordance with the invention in its first mode of operation,
FIG. 3 shows schematically the apparatus of FIG. 2 in its second mode of operation, and
FIG. 4 shows schematically a modified form of the apparatus of FIG. 2 in its second mode of operation.
DETAILED DESCRIPTION
In FIG. 1 there is shown a waste heat recovery boiler 10 , including wall structures surrounding a heat transfer space 11 . The heat transfer space 11 is preferably arranged substantially vertical and it comprises preferably two parallel flow ducts 11 ′, 11 ″, which abut at their other ends, here at their lower ends, on a common space. The ducts 11 ′, 11 ″ are separated by a vertical intermediate wall 17 . At least one heat exchanger 12 , 13 is arranged in each of the parallel ducts. The heat exchangers have heat transfer surfaces of substantially equivalent heat transfer capability. For example, their surface areas may correspond or they may be otherwise arranged so that their operation corresponds to each other. There may also be other heat exchangers and such are preferably located between the heat exchangers 12 and 13 in the gas flow direction.
Correspondingly at their other ends the ducts 11 ′, 11 ″ abut on a means for altering the direction of gas flow, which means here comprises two chambers 14 , is separated from each other by a partition wall 16 . It should be noted that the plane of the partition wall 16 is inclined to the plane of the intermediate wall 17 limiting the flow ducts 11 ′, 11 ″. The partition wall 16 prevents direct flow communication between the gas inlet 18 and the gas outlet 19 . The gas inlet 18 is in operational connection with gas production equipment 2 (shown in FIGS. 2, 3 and 4 ). Advantageously the gas production equipment may be a piston engine utilizing gaseous fuel, in view of the consistence of and temperature level of the gases from such engine. The wall structures of the heat transfer space 11 operate also as walls limiting the chambers 14 , 15 , whereby the apparatus is constructed as an integrated unit. The walls limiting the chambers 14 , 15 , including the partition wall 16 and the intermediate wall 17 , may be constructed for example as cooled walls, whereby these walls also include heat transfer surfaces. Additionally, being substantially vertical, the ducts 11 ′, 11 ″ may easily he ventilated for removing hot exhaust gases on shut-down, for example for maintenance.
The chambers 14 and 15 are selectively connectable to the flow ducts 11 ′ and 11 ″ so that gas is caused to pass always through the two ducts in series. This is accomplished by means of the valves 20 , 21 provided in the chambers 14 , 15 . In the figure the valves are illustrated as slide-type valves, by means of which the opening from the chamber 14 to one of the ducts 11 ′, 11 ″ is open and the other opening is closed, and similarly for the chamber 15 . The valves may also be of a different type, such as butterfly-valves. The valves should be positively controlled so that each chamber 14 or 15 may be connected to only one of the ducts 11 ′, 11 ″ at a time, and so that the gas will always pass through the two ducts in series. The flow control of the gas by the slide valves 20 , 21 shown in the figure takes place by executing a pull or push movement of the shaft of the valves.
Operation of the apparatus will be described in the following with reference to FIG. 2 . FIG. 2 illustrates several valves. Valves that are open are illustrated by thicker lines than valves that are closed. The gas is caused to flow from the gas production equipment 2 to the gas inlet 18 . After passing through the gas inlet 18 , the gas flow is guided in a respective desired manner into the heat transfer space 11 . In a first mode of operation shown herein, the valve 21 directs the gas into the duct 11 ′. The gas flows in the duct 11 ′ substantially vertically downwards and passes the heat exchanger 12 transferring heat to heat transfer medium flowing in the heat exchanger. As can be seen from FIG. 2, the heat exchanger 12 is connected to a first heat transfer circuit 311 , 312 , which operates at higher temperature level than a second heat transfer circuit 301 , 302 . The first heat transfer circuit will be also referred to as the HT-circuit and the second heat transfer circuit will be referred to as the LT-circuit. The apparatus thus comprises valves 212 , 214 , 221 , 223 , 222 , 244 , 211 , 213 for connecting the heat transfer circuits selectively to the heat exchangers 12 , 13 . The heat transfer medium from the first heat transfer circuit 311 , 312 is guided under control of the valves 212 , 214 either to the heat exchanger 12 located in the duct 11 ′ or to the heat exchanger 13 located in the duct 11 ″. In the first mode of operation, which is shown in FIG. 2, the valve 212 is open and valve 214 is closed. The heat transfer medium is thus guided to the heat exchanger 12 located in the duct 11 ′, which heat exchanger 12 is upstream in the gas flow. The heat transfer medium is guided back to the first heat transfer circuit under control of valves 221 and 223 . In the first mode of operation, the valve 221 is open and valve 223 is closed.
After passing the heat exchanger 12 , the gas enters the common space connecting the flow ducts 11 ′, 11 ″, from which it passes to the second flow duct 11 ″ by changing its flow direction about 180° upwards. The gas flows upwards in the duct 11 ″ through the heat exchanger 13 transferring heat to the heat transfer medium flowing in the heat exchanger. As can be seen from FIG. 2, the heat exchanger 13 is connected to the second heat transfer circuit 301 , 302 , which operates at a lower temperature level than the first heat transfer circuit 311 , 312 . The heat transfer medium from the second heat transfer circuit 301 , 302 is guided under control of valves 222 and 224 either to the heat exchanger 12 located in the duct 11 ′ or to the heat exchanger 13 located in duct 11 ″. In the first mode of operation the valve 222 is closed and the valve 224 is opened, whereby the second heat transfer medium is guided to the heat exchanger 13 in the duct 1111 , which heat exchanger is downstream in the gas flow. The apparatus is operated in this first mode of operation for a desired period of time or advantageously until the mode of operation is altered based on a predetermined event.
The predetermined event comprises preferably the following. During the operation of the apparatus, measurement information is collected by a central processing unit 1 at least from the heat transfer process. The collected measurement information is compared with set values, which have been stored in or are available to the central processing unit 1 , and in the event that the measured information differs from the set values by more than a predetermined amount, the mode of operation of the arrangement is altered. Information regarding the heat transfer media is collected by temperature senders 23 , 24 provided in the heat transfer medium channels and/or information regarding gas pressure difference and/or gas temperature is collected by pressure and/or temperature senders 25 , 26 provided in the gas flow channels to be used as measurement information. Thus, when for example the pressure difference of gas flow increases beyond a set value or the temperature of heat transfer medium coming from a heat exchanger is not at a predetermined level, the mode of operation is altered.
FIG. 3 shows the second mode of operation, which will be described in the following. The gas supplied to the apparatus is now caused to flow from the gas production equipment 2 through the gas inlet 18 to the duct 11 ″. Gas flows in the duct 11 ″ substantially vertically downwards and passes the heat exchanger 13 transferring heat to heat transfer medium flowing in the hear exchanger. As can be seen from FIG. 3, the heat exchanger 13 , which was connected to the LT-circuit 301 , 302 during the first mode of operation, is now connected to the HT-circuit 311 , 312 whereby a cleaning effect of heat transfer surfaces according to the invention is provided. The deposits that accumulated on the surfaces of the heat exchanger when operating in the first mode soften. Especially, when the apparatus is used for heat recovery from exhaust gases of a gas engine, components that condense and harden on a relatively cool heat transfer surface of the heat exchanger 13 in the first mode of operation soften and drain down from the heat transfer surface of the heat exchanger, where from they can be removed from the apparatus through a discharge valve 28 , which is preferably controlled by the central processing unit 1 for example so that the valve is opened during a selected interval after each change in mode of operation.
The heat transfer medium of the HT-circuit 311 , 312 is guided through the open valve 214 of the valve pair 212 , 214 to the heat exchanger 13 in the duct 11 ″, which is now upstream in the gas flow. The heat transfer medium is guided back to the first haet transfer medium circuit under control of the open valve 223 of the valve pair 221 , 223 .
After passing the heat exchanger 13 , the gas enters the common space connecting the flow ducts 11 ′, 11 ″, from which space the gas is guided further upwards through the flow duct 11 ′ by changing its flow direction through 180λ. In this duct, the gas flows upwards through the heat exchanger 12 and transfers heat to the heat transfer medium flowing in the heat exchanger 12 . As can be seen from FIG. 3, the heat exchanger 12 is connected to the second heat transfer circuit i.e. to the LT-circuit 301 , 302 . The heat transfer medium of the LT-circuit 301 , 302 is guided through the open valve 222 of the valve pair 222 , 244 to thee heat exchanger 12 in the duct 11 ′, which heat exchanger is now downstream in the gas flow. The arrangement is now operated in this second mode of operation for a desired period of time or advantageously until the mode of operation is altered again based on a predetermined event.
A controllable central processing unit 1 or the like is provided for controlling the operation of the valves. The operation of the valves 20 , 21 guiding the gas flow is synchronized with valves 211 , 212 , 213 , 214 , 221 , 222 , 223 , 224 guiding the heat transfer medium so that the valves of each chamber 14 , 15 are positively controlled so that a flow connection from a chamber may be established with only one of the flow ducts 11 ′, 11 ″ at a time, the gas is always caused to pass through both of the ducts 11 ′, 11 ″, and the HT-circuit is always connected with the heat exchanger that is upstream of the heat exchanger connected to the lt-circuit.
FIG. 4 shows a modification of the apparatus shown in FIGS. 2 and 3. In the case of the apparatus shown in FIG. 4, the heat transfer surface of the first heat exchanger 12 is larger than that of the second heat exchanger, so that in the first mode of operation heat is transferred more effectively to the first heat transfer medium than to the second heat transfer and the first heat transfer medium is heated to a higher temperature than the second heat transfer medium. In the second mode of operation, in which the second heat transfer medium flows through the first heat exchanger 12 , some of the heat transfer medium of the LT-circuit may be guided to bypass the first heat exchanger via a conduit 227 . The by-pass flow rejoins the flow through the heat exchanger 12 downstream of the valve 211 . The temperature of the second heat transfer medium, after mixing the by-pass flow and the flow through the heat exchanger 12 , corresponds to the situation when operating in the first mode of operation. The flow of gas in this case corresponds to that shown in FIG. 3 . The heat exchanger 13 is now connected to the first heat transfer circuit i.e. the HT-circuit 311 , 312 . According to FIG. 4, in order to compensate or offset the greater power obtained by the larger surface area of the heat exchanger 12 , a part of the heat transfer medium of the LT-circuit 301 , 302 may be guided to bypass the heat exchanger 12 through the conduit 227 . The conduit 227 is advantageously provided with a closing or shut-off valve 225 and control valve 226 , by means of which the flow rate may be adjusted. The arrangement is operated in the second mode of operation for the time required for cleaning of the heat exchanger 13 , after which the mode of operation is changed again.
The foregoing disclosure is merely one possibility to implement the arrangement with heat transfer circuits, and in addition the heat transfer circuits may be provided with separate loops operated by circulation pumps. In this manner the inlet and outlet flows of the separate loops may be separately adjusted (not shown).
A corresponding effect may also be achieved by guiding the gas-side flow by altering the position of the valve so that some gas bypasses the heat exchanger directly through heat exchanger space from chamber 14 to chamber 15 . This may be accomplished for example so that the pair of openings, which is in principle required to be closed by each mode of operation, is not totally closed, but both of the valve openings in the chamber are left partly open by the valves 20 , 21 (FIG. 1 ).
In some cases, for example in order to ensure monitoring of the apparatus during the operation, it may be advantageous to perform the cleaning, i.e. change the mode of operation, by operating fully manually.
The invention is not limited to the illustrated embodiments but several modifications of the invention are reasonable within the scope of the attached claims. The heat exchanger apparatus may be designed to operate in an orientation that is inverted with respect to that shown, and the ducts 11 ′, 11 ″ are above the chamber 14 , 15 . The heat exchangers may, as to their actual connections to the heat transfer medium circuit, operate either as parallel, counter or cross flow type. The apparatus may also comprise other heat exchangers and heat transfer circuits.
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Apparatus for recovering heat from a gas flow defines a heat transfer space through which the gas flow can be directed, the heat transfer space having a first region and a second region, a gas inlet and a gas outlet. A first valve arrangement alters the direction of gas flow through the heat transfer space, the first valve arrangement having a first condition in which the first region is upstream of the second region and a second condition in which the second region is upstream of the first region. First and second heat exchangers are disposed in the first and second regions respectively of the heat transfer space. A second valve arrangement connects each heat exchanger selectively either to a first heat transfer medium flow circuit or to a second heat transfer medium flow circuit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an acidic bleaching solution that generates little or no chlorine gas during use and which is particularly effective as a cleaner for removing soapscum, limescale, mold and mildew from treated surfaces. The invention also relates to a bleaching system for forming the acidic bleaching solution and a method of preparing the acidic bleaching solution.
2. Related Background Art
Bleach/sulfamic acid cleaning compositions have long been known. For example, UK Patent Application GB 932,750 discloses a powdered cleansing composition containing alkali metal monopersulfate salts and alkali metal chlorides in combination with a nitrogen-containing chlorine-hypochlorite acceptor such as sulfamic acid. The chlorine generated upon the addition of water to the composition is said to be tied up by the nitrogen-containing chlorine-hypochlorite acceptor so as to reduce or eliminate the expected chlorine odor.
A sanitizing composition which is said to have an improved shelf life in the dry state is described in UK Patent Application GB 2078522. The composition comprises sodium or calcium hypochlorite, an acid source which desirably includes sulfamic acid in combination with another non-reducing acid such as malic acid or succinic acid and a surfactant. The acid content of the composition is said to enhance the ability of the composition to sanitize surfaces with lime scale or milk stone. This composition, however, has been reported to evolve chlorine gas when stored in damp conditions or when prepared in concentrated aqueous solutions.
U.S. Pat. No. 4,822,512 reportedly overcomes this problem through the use of a low level of water-soluble inorganic halide in the composition, such as sodium chloride. In particular, a water-soluble biocidal composition is described as (a) 0.01 to 5 parts by weight of a water-soluble inorganic halide, (b) 25 to 60 parts by weight of an oxidizing agent which, in aqueous solution, reacts with halide to generate hypothalite ions, (c) 3 to 8 parts by weight of sulfamic acid, (d) 0 to 20 parts by weight of an anhydrous non-reducing organic acid such as malic acid or succinic acid and (e) 10 to 30 parts by weight of an anhydrous alkali metal phosphate. The pH of a 1% by weight aqueous solution of this composition is between about 1.2 and 5.5. The aforementioned compositions, however, are directed to dry or powder compositions and thus do not contemplate the problems associated with aqueous liquid bleach solutions.
In particular, it is well known that the addition of an aqueous hypochlorite solution to an acidic cleaning solution will generally result in the evolution of potentially dangerous amounts of chlorine gas. A number of compositions have been proposed in an attempt to overcome this problem. U.S. Pat. No. 3,749,672 is directed to buffered aqueous solutions having a pH between 4 and 11 which are prepared by adding a hypochlorite such as sodium hypochlorite to certain N-hydrogen compounds such as sulfamic acid. In particular, it is said that stable bleaching compositions under acid conditions (e.g. pH of about 4.0 to 6.9) may be obtained when there is an excess of sulfamate (e.g., a mole ratio less than 2:1 of hypochlorite to sulfamate). However, the presence of the excess sulfamate is likely to result in a hypochlorite-sulfamate complex which will decrease the bleaching kinetics or efficiency of the composition.
U.S. Pat. No. 5,503,768 describes a halogen scavanger constituted by an aromatic ring and at least one group which contains a lone-pair-containing hetero atom adjacent to the aromatic ring. The electron donating aromatic compound, i.e., the halogen scavenger, can be added to an acid cleaner which when mixed with an oxidizing agent such as sodium hypochlorite prior to use suppresses the release of halogen gas. It is reported that it is desirable to add the electron donating aromatic compound to the acid cleaner in an approximately equal molar amount to the halogen estimated to be released upon the mixture of the acid cleaner with the oxidizing agent.
There continues, however, to be a need for acidic bleaching compositions that do not result in the substantial generation of potentially hazardous chlorine gas when a hypochlorite solution is mixed with an acidic solution. Such acidic bleaching compositions, i.e., low chlorine gas generation, that have excellent bleaching efficacy are particularly desirable.
SUMMARY OF THE INVENTION
This invention relates to an acidic bleaching solution prepared by the process of mixing
(a) a first aqueous solution having a pH of about 6 or less comprising:
(i) a chlorine deactivating agent; and
(ii) a non-oxidizable acid; and
(b) a second aqueous solution having a pH of about 10 or greater comprising:
(i) a hypochlorite salt having 7% by weight or less of residual chloride ion; and
(ii) optionally a thickening agent, wherein said bleaching solution has a pH of about 6 or less and a molar ratio of hypochlorite ion to said chlorine deactivating agent when said first aqueous solution is mixed with said second aqueous solution is about 3.60 to about 2.5. Exemplary chlorine deactivating agents include sulfamic acid and the salts thereof, isocyanurates, imidosulfonates, carbamates, sulfonamidates and heterocyclic compounds including, for example, glycolurils, hydantoins and succinimides. Other exemplary chlorine deactivating agents include aromatic compounds which have a resonance-effect-relying electron donating group as a constituent. Sulfamic acid and the salts thereof are most preferred.
The acidic bleaching solution of this invention is highly effective for bleaching mold stains on ceramic tiles and like surfaces. The inventive solution may also be employed for bleaching foods, beverages and general soil stains on other hard surfaces such as linoleum, as well as soft surfaces such as laundry and carpets.
Another aspect of this invention is directed to a bleaching system for forming the above-described solution. The system is comprised of a first vessel containing the first aqueous solution and a second vessel containing the second aqueous solution. The first and second vessels can be, for example, either two separate containers or two separate compartments within a single container. The bleaching system is used to form the bleaching solution by mixing an amount of the second solution so that the hypochlorite ion is mixed with the chlorine deactivating agent at a molar ratio of 3.60 to 2.50 to provide a solution having a pH of about 6 or less.
Another aspect of this invention is directed to a method of preparing the acidic bleaching solution of this invention. This method comprises mixing the above-described first aqueous solution and second aqueous solution to form the acid bleaching solution of this invention. This method advantageously results in a highly effective acidic bleaching solution which generates 5 ppm of chlorine gas or less after the solutions are mixed.
DETAILED DESCRIPTION OF THE INVENTION
The acidic bleaching solution of this invention is prepared by the admixture of a first aqueous solution containing a chlorine deactivating agent and a nonoxidizable acid with a second aqueous solution containing a hypochlorite salt and optionally a thickening agent. The pH of the first aqueous solution is about 6 or less, while the pH of the second aqueous solution is about 10 or greater. The pH of the mixture of the two aqueous solutions is about 6 or less. Most preferably the pH of the acidic bleaching solutions is about 4-5. Acidic bleaching solutions having a pH below 4 are generally not preferred because such solutions require an excess of chlorine deactivating agent.
Chlorine deactivating agents are well known. Sulfamic acid and water soluble salts thereof are preferred in the present invention. Such water soluble salts include, for example, sodium, potassium, magnesium, calcium, lithium and aluminum salts of sulfamic acid. Sulfamic acid itself, however, is most preferred.
Other chlorine deactivating agents useful in the present invention include, for example, isocyanuric acid, succinimide, cyanamide, dicyandiamide, melamine, ethyl carbamate, urea, thiourea, 1,3-dimethylbiuret, methyl phenylbiuret, barbituric acid, 6-methyluracil, 2-imidazolinone, iron, 5,5-dimethylhydantoin, ethyleneurea, 2-pyrimidinone, benzamide, phthalimide, N-ethylacetamide, azetidin-2-one, 2-pyrrolidone, caprolactam, sulfamide, p-toluenesulfonamide, phenyl sulfinimide, phenyl sulfinimidylamide, diphenyl sulfonimide, dimethyl sulfinimine, isothiazolene-1,1-dioxide, orthophosphoryl triamide, pyrophosphoryl triamide, phenyl phosphoryl-bis dimethylamide, boric acid amide, methanesulfonamide, melamine, pyrrolidone, hydantoin, acetanilide, acetamide, N-methylurea, acetylurea, biuret, ethyl allophanate, pyrrole and indole.
Additional useful chlorine deactivating agents include the electron-donating aromatic compounds described in U.S. Pat. No. 5,503,768, the disclosure of which is incorporated by reference herein.
Generally, the chlorine deactivating agent is present in the first aqueous solution in an amount between about 0.05% to about 10.0%, preferably between about 0.5% to about 4.0% by weight of the first aqueous solution. However, a critical aspect of this invention is that the chlorine deactivating agent present in the first aqueous solution should be combined with the hypochlorite of second aqueous solution at a molar ratio of hypochlorite to chlorine deactivating agent between about 3.60 and about 2.5, preferably between about 3.40 and about 2.80.
The nonoxidizable acid employed in the first aqueous solution is resistant to oxidation by hypochlorite salts. Typically it is present in amount of up to the buffer capacity of the first aqueous solution. Accordingly, the nonoxidizable acid is generally present in amounts from about 3% to about 15%, most preferably between about 6% to about 10% by weight of the first aqueous solution. Preferred nonoxidizable acids include succinic, adipic and oxalic acids. Other potential nonoxidizable acids include polyphosphates, polycarboxylates and diphosphonates, particularly aliphatic or cyclic diphosphonates, such as etridonic acid (EHDP).
The first aqueous solution may also contain a base to adjust the pH. Generally the pH of the first aqueous solution is adjusted to about 2-6, preferably 4-5 by the addition of a base such as sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide. Since the first aqueous solution acts as a buffer, the ultimate pH of the acidic bleaching solution of this invention will generally approximate the pH of the the first aqueous solution. Other components of the first aqueous solution may include surfactant(s), hydrotrope(s), solvent(s), fragrance(s) and the like.
Surfactant(s) may also be included in the first aqueous solution to enhance the cleaning and/or foaming properties of the acidic bleaching solution of this invention. Such surfactants include, but are not limited to, linear alkyl benzene sulfonates, lauryl sulfates, alcohol ether sulfates and the like. Other surfactants that may be present, but are less preferred, are ethoxylated nonionic surfactants. The amount of surfactant utilized in the first aqueous solution is determined by the surfactant cleaning properties as well as the particular application for which the acidic bleaching solution is formulated. Generally, the surfactant is present in an amount between about 0 to 15% by weight of the first aqueous solution.
Hydrotropes may be employed in the first aqueous solution to assist in blending of solvents and surfactants, if present. Therefore the amount of hydrotrope is dependent upon the concentration of the solvents and surfactant. Generally, the hydrotrope is present in an amount between about 0 to about 8%, preferably about 2% to about 6% and most preferably about 4% by weight of the first aqueous solution. A preferred hydrotrope is sodium xylene sulfonate. Other exemplary hydrotropes include sodium butyl monoglycol sulfate, sodium toluene sulfonate and sodium cumene sulfonate.
Organic solvents may also be present in the first aqueous solution to enhance the cleaning efficiency of the acidic bleaching solution of this invention. Such organic solvents are well known to those of ordinary skill in the art. A preferred solvent is 2-(2-hexyloxy ethoxyl) ethanol available as Hexyl Carbitol® from Union Carbide, Danbury, Conn. Other typical solvents that may be employed in this invention include glycol ethers such as, for example, ethylene glycol monobutyl ether or ethylene glycol monohexyl ether available as Butyl Cellusolve® and Hexyl Cellusolve®, respectively, from Union Carbide, as well as various Dowanol® solvents available from Dow Chemical, Midland, Mich. The solvent is generally present in the first aqueous solution in an amount of about 0 to 10%, more preferably about 3% to 7% by weight of the first aqueous solution.
The hypochlorite salts employed in the present invention include, for example, potassium hypochlorite, sodium hypochlorite, lithium hypochlorite and the like. Sodium hypochlorite is most preferred. A critical aspect of this invention is that the hypochlorite salt must have 7% or less residual chloride ion content, most preferably less than 1.0% by weight of the hypochlorite salt. Sodium hypochlorite having such a low residual chloride ion content is available from Olin Corporation, Charleston, Tennessee under the tradename "Hypure".
Generally the hypochlorite salt is present in an amount between about 0.5% to about 12%, preferably about 1.0% to about 5% by weight of the second aqueous solution. Again, the amount of hypochlorite salt will depend upon the amount of chlorine deactivating agent present in the first aqueous solution and the mixing ratio of the two aqueous solutions, as well as the desired bleaching efficiency of the resulting acidic bleaching solution.
The second aqueous solution also preferably contains a thickening agent. Polyacrylate thickeners are preferred, although any thickener may be employed which is not deleteriously affected by the hypochlorite salt. Generally the thickening agent is present in the second aqueous solution in an amount from about 0 to about 5%, preferably from about 1% to about 3% by weight of the second aqueous solution.
For the best stability and most efficient bleaching efficacy the acidic bleaching solution is prepared just prior to use by admixture of the first aqueous solution and the second aqueous solution. Accordingly, another aspect of this invention is directed to a bleaching system for conveniently forming the acidic bleaching solution of this invention just prior to use.
The preferred bleaching system of this invention is comprised of two vessels. The first vessel contains the first aqueous solution and a second vessel contains the second aqueous solution. The concentration of the components in the first and second solutions is selected so that when a given amount of the first aqueous solution is mixed with a given amount of the second aqueous solution the above-described acidic bleaching solution is obtained. Thus, the concentrations of the components in the first aqueous solution and the second aqueous solution will be dependent upon the ratio of the mixture of the two solutions. Once it is decided what fixed amount of the first aqueous solution is to be combined with a fixed amount of the second solution, then the determination of the amounts of each component in each solution, particularly the amounts of hypochlorite salt and chlorine deactivating agent, is a simple arithmetic calculation, i.e., a routine calculation to those having ordinary skill in the art.
The vessels employed in the bleaching system of this invention can each be separate containers or can be a single container having two compartments. For instance, a single container having two compartments or vessels holding the first aqueous and second aqueous solutions and having a pump line inserted into each compartment and merging at a single pump spray mechanism may be employed. On the other hand, the bleaching systems of this invention can simply consist of two separate containers holding the first aqueous and second aqueous solutions which can be mixed by adding a predetermined amount of one solution to a predetermined amount of the other. Other delivery mechanisms which provide a means for mixing the components of the bleaching solution of this invention are also contemplated. Exemplary containers for use with the bleaching system of this invention are disclosed in U.S. Pat. No. 5,398,846 entitled "Assembly for Simultaneous Dispensing of Multiple Fluids", the disclosure of which is incorporated by reference as if fully set forth herein.
The present invention is also directed to the method of preparing the acidic bleaching solution of this invention. The method comprises the step of combining the previously described first aqueous and second aqueous solutions so that the ratio of the hypochlorite ion added to the chlorine deactivating agent is between about 3.60 and 2.5, preferably about 3.40 to about 2.80 and the resulting acidic bleach solution has a pH of 6 or less, most preferably 5 to 4.
The examples which follow are intended as an illustration of certain preferred embodiments of the invention, and no limitation of the invention is implied.
EXAMPLE 1
A first aqueous solution was prepared having the following components:
______________________________________Components % w/w______________________________________Deionized Water 72.2NaOH 2.20Hexyl Carbitol.sup.1 5.00Sodium Xylene Sulfonate 4.00Succinic Acid 7.00Sulfamic Acid 1.00Fragrance 0.60Calsoft L-60 (58% actives).sup.2 5.00Calfoam ES-603 (59% actives).sup.3 3.00______________________________________ .sup.1 2(2-Hexyloxy ethyloxy) ethanol available from Union Carbide, danbury, Connecticut .sup.2 Sodium dodecylbenzene sulfonate; available from Pilot Chemical, re Bank, New Jersey. .sup.3 Sodium lauryl ether sulfate; available from Pilot Chemical, Red Bank, New Jersey.
The resulting first aqueous solution had a pH of about 4.2.
A second aqueous solution was prepared having the following components:
______________________________________Components % w/w______________________________________Deionized Water 89.5Sokalan PA 50 (40% actives, pH 7).sup.1 2.0Sodium Hypochlorite, low salt, 20%.sup.2 8.5______________________________________ .sup.1 A polyacrylate thickener; available from BASF, Parsippany, New Jersey. .sup.2 Hypure N (0.53% chloride ion content) available from Olin Corp., Charleston, Tennessee.
The resulting second aqueous solution had a pH of about 12.
An acidic bleaching solution was prepared by placing the first aqueous solution (the cleaning solution) and the second aqueous solution (the bleaching solution) in separate chambers of a dual chambered bottle. The bleaching solution and cleaning solution were codispensed at an equal rate and sprayed into an enclosed 10 inch (25.4 cm)×10 inch (25.4 cm)×16 inch (40.6 cm) plexi-glass box. The combined solution had a pH of 4.17. No chlorine gas was detected by measurement with a Matheson-Kitagawa Gas Analyzer, Model #8014-400A and Matheson-Kitagawa Precision Gas Detector Tubes (Tube #1092b, Chlorine, 0.1-10 ppm) over a time interval of 15-20 minutes after application of the acidic bleaching solution.
Bleaching Efficacy
The acidic aqueous solutions of this invention were assessed for the ability to bleach common mold and mildew found on shower tiles in a typical bathroom. White, 4 inch (10.2 cm)×4 inch (10.2 cm), ceramic tiles were used. These tiles were quartered, washed and dried prior to inoculation with A. niger in Czappek Dox Broth. The tiles were placed in humidity chambers that were equilibrated with a saturated solution of sodium phosphate to maintain a humidity of 80-95% and incubated at 28° C. for 7 to 21 days until a desired amount of mold growth was obtained.
The bleaching solution to be tested was then applied to the tile by spray from a dual chambered bottle. Subtantially equivalent amounts of bleaching solution were applied to separate tiles and the tile was allowed to stand for specified time period (5-25 minutes). After the specified time interval, each tile was assessed for whiteness and rated on a scale of 0 to 4 (0- no bleaching; 1-25% bleaching; 2-50% bleaching; -75% bleaching; 4-100% bleaching). The results of the bleach efficacy test are set forth in Table 1, infra.
Comparative Example 1
An acidic aqueous bleaching solution was prepared in a manner similar to Example 1, with the exception that the first aqueous solution did not contain sulfamic acid. Approximately 40 ppm of chlorine gas was detected upon mixing the first aqueous solution with the second aqueous solution.
Examples 2-4 and Comparative Examples 2-8
The effect of changing the hypochlorite/sulfamic acid ratio (B/SA) at a constant pH was studied by preparing first aqueous solutions in the manner described in Example 1, but varying the concentration of sulfamic acid and sodium hydroxide. The sodium hydroxide was varied to adjust the first aqueous solution to a pH of about 4.2.
The concentration of the sulfamic acid and ratio of hypochlorite ion to sulfamic acid (on both a weight/weight basis and a molar basis) for each formulation (including Example 1), as well as the chlorine gas generation data and the bleach efficacy (Bleach Eff., are set forth in Table 1 below.
TABLE 1______________________________________ B/SA Cl.sub.2 B/SA BleachFormulation %SA (%w/w) pH (ppm) (molar) Eff.______________________________________Compar. 2 0.5 3.4 ˜4.2 15 6.43 4Compar. 3 0.6 2.83 ˜4.2 15 5.35 3Compar. 4 0.67 2.54 ˜4.2 10 4.80 4Compar. 5 0.7 2.43 ˜4.2 10 4.59 2Compar. 6 0.75 2.27 ˜4.2 5 4.29 2Compar. 7 0.8 2.13 ˜4.2 10 4.03 2Compar. 8 0.85 2 ˜4.2 10 3.78 2Example 2 0.9 1.9 ˜4.2 5 3.59 2Example 3 0.95 1.8 ˜4.2 1 3.40 2Example 1 1.0 1.7 ˜4.2 0 3.21 2Example 4 1.1 1.55 ˜4.2 0 2.93 2______________________________________ B = .sup.- OCl formula weight SA = Sulfamic acid formula weight
Other variations and modifications of this invention will be obvious to those skilled in the art.
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An acidic bleaching solution formed from the admixture of a first aqueous solution containing a chlorine deactivating agent and a second aqueous solution containing a hypochlorite salt is disclosed. Also disclosed is a bleaching system for forming the acidic bleaching solution, as well as a method of preparing the acidic bleaching solution. The acidic bleaching solution advantageously generates little or no chlorine gas while being a particularly effective cleaner for removing soapscum, limescale, mold and mildew from treated surfaces.
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BACKGROUND OF THE INVENTION
This invention relates to a container assembly for the storage, display, and advertisement of iced beverage products, such as bottled and canned beverages.
Container assemblies of the type with which this invention is concerned allow for easy access to chilled beverages so as to induce impulse purchase of an iced beverage product. The assembly is generally a self-supporting stand and a bucket or container which is large enough to hold a substantial quantity of ice and beverage bottles or cans, but small enough so as not to substitute for a more conventional display case for cooled beverage products Generally, these units are easily movable giving a store owner unlimited flexibility as to the location of the units within the store. The container assemblies are most often located near the entrance or exit of the store so as to give potential customers easy access to the beverages and to provide an eye-catching advertisement which everyone exiting or entering the store must pass.
Because these container assemblies are used to store iced beverage products, most have some means by which water can be drained from the assembly as the ice melts. Conventionally, these drainage means comprise a drainage opening in the bucket container and a flow control valve or spigot connected to the bottom of the container. Because there is no indication of how much water may be existent in the container or in the reservoir if the assembly includes a water reservoir beneath the container to catch overflow of melted ice, someone must regularly check the level of water in the container or reservoir. But, even if regularly checked so as to avoid overflow and spillage, the container or reservoir must be drained by locating a bucket beneath the drain spigot or valve and then draining the water from the bucket. This is oftentimes an inconvenient procedure, particularly when it must be conducted with more regularity than is necessary in order to avoid periodic overflow.
Beverage display bins of the type described hereinabove are also subject to problems with the drain valves. Of course, if those drain valves leak, there is a potential for water on the floor of a commercial establishment causing accidents if store visitors slip on the resulting water pool.
It has therefore been an objective of this invention to provide an improved iced beverage display bin or container assembly which eliminates the need to drain the bin of melted ice more regularly than is absolutely required in order to prevent overflow of the water resulting from melted ice contained in the bin.
Still another objective of this invention has been to provide an improved chilled beverage display bin which is less expensive than prior art bins and which eliminates the potential for spillage resulting from a defective drainage valve or spigot.
SUMMARY OF THE INVENTION
These objectives are achieved in accordance with the practice of this invention by a chilled beverage display bin in the form of a container assembly for containing and displaying iced beverage products, which assembly comprises a self-supporting open-top stand and a liquid-impervious storage tank or bucket supported from and contained internally of the stand. The bottom of the bucket has a drainage hose extending therefrom, which drainage hose is transparent or translucent and extends through a hole in the sidewall of the stand to the exterior thereof. From the exterior of the stand, this hose mounts in a channel of the stand and extends upwardly to the top of the stand. The hose contains no valve, but because it extends to the top of the stand and to the vertical height of the top of the bucket, the hose functions not only as a flow control device or valve, but also as a telltale of the level of water in the container or bucket of the assembly. Thereby, the need for a flow control valve or spigot is eliminated. All that is required to drain the bucket of water is to remove the hose from the channel of the stand and place the end of it in a bucket at a location below the level of water in the stand.
The container assembly of this invention eliminates the need for a potential leak source in the form of a flow control valve or spigot attached to the drainage opening of the ice containing bucket or container of the assembly, and thereby renders the assembly not only safer because of the elimination of the potential for a leaky valve, but additionally renders the assembly less expensive than prior art valve-containing assemblies. Additionally, the flexible hose serves as a telltale of level of water in the container of the assembly such that the container need not be emptied more often than absolutely necessary.
These and other objects and advantages of the invention will be more readily apparent from the following description of the drawings in which:
FIG. 1 is a perspective view of a container assembly for storage and display of iced beverage containers embodying the invention of this application.
FIG. 2 is a cross-sectional view of the container assembly taken on line 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view similar to FIG. 2, but illustrating the manner of draining water from the container of the assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, the container assembly 2 of this invention comprises a hollow, open-top, self-supporting body or stand 4, a liquid-impervious bucket or storage tank 6, and a flexible, transparent or translucent drainage hose 10 for draining liquid from the tank 6. The hose 10, in the stored position illustrated in FIG. 2, also functions as a telltale for enabling the level of liquid in the tank 6 to be visually determined from outside the assembly.
The container assembly 2 is, in one preferred embodiment, equipped with a top closure 12 which is hingedly connected to the top edge 15 of the sidewall 14 of the self-supporting body or stand 4. As illustrated in FIG. 3, the top closure 12 may be lifted away from the top 15 of the supporting body 4 about a hinge 17 to allow access to beverage containers 11, such as cans or bottles, contained in the storage tank 6. The top closure 12 is preferably transparent or translucent enough to allow visual inspection of the beverage containers 11 or other iced objects located within the container assembly 2 without requiring a person to lift the closure 12. In the preferred embodiment, the closure 12 is molded so as to simulate ice cubes, as is best illustrated in FIG. 1.
The self-supporting body or stand 4 of the container assembly 2 has a bottom 16, sidewalls 14, and an open top 20. The self-supporting body 4 is generally triangular when viewed in top plan and is hollow to allow the container or storage tank 6 to be contained within the supporting body 4 with a top flange 22 of the tank 6 resting atop the top edge 15 of the stand 4. Alternatively, the stand 4 and tank 6 may be rotationally molded as a common plastic casting.
Located inside and supported by the self-supporting body 4 is the bucket or storage tank 6. The storage tank 6 is liquid impervious so as to contain water derived from the melted ice 7 upon which the beverage containers are supported. The storage tank 6 has a bottom wall 24, sidewalls 26, and an open top 28. Preferably, the sidewalls 26 of the tank 6 define a triangle when viewed in top plan so that the tank is of the same general peripheral configuration as the stand 4. Though the top of the storage tank 22 is approximately flush with the top of the self-supporting body 20, the bottom wall 24 of the storage tank 6 is located in a plane substantially above the bottom 16 of the self-supporting body 4. This allows a customer access to items contained within the tank 6 without requiring the customer to reach down to floor level to reach an item.
The storage tank 6 is equipped with a drainage opening and spout 8 that is located in or near the bottom of the storage tank 24. This spout is provided to allow drainage of the storage tank 24 as ice 7 in the tank melts and liquid accumulates.
Attached to the drainage spout 8 is the transparent or translucent flexible drainage hose 10. Referring to FIG. 3, it will be seen that one end portion 29 of the drainage hose 10 is located internally of the self-supporting body 4 and another end portion 30 is located externally of the self-supporting body 4. The drainage hose 10 passes from inside the self-supporting body 4 to outside the self-supporting body 4 via an opening 32 in the sidewall 14 of the self-supporting body 4. The end 34 of the outside portion 30 of the drainage hose 10 is open and is releasably supported near the top 20 of the self-supporting body 4. When the storage tank 6 is not being drained, the external portion 30 of the drainage hose 10 extends approximately vertically upward from the opening 32 in the sidewall 14 of the self-supporting body 4 to approximately the top 20 of the self-supporting body 4.
Referring to FIG. 2, the external portion 30 of the drainage hose 10 is preferably supported within a concave channel 36 in the sidewall 14 of the self-supporting body 4. The concave channel 36 runs vertically along the sidewall 14 of the self-supporting body 4 and is molded into the corner of the sidewall 14 as shown in more detail in FIG. 1. It is preferably sized relative to the outside diameter of the hose such that the hose snaps into and is frictionally retained within the channel. To ensure that the hose 10 remains in the channel and is not inadvertently dislodged therefrom, the top end of the hose may be inserted into a hole in the top of the stand. The external portion 30 of the drainage hose 10 is removable from the concave channel 36 to facilitate drainage (see FIG. 3) and is returnable to an upright vertical position after the tank has been completely drained (see FIG. 2). When in an upright vertical position, the external portion 30 of the drainage hose 10 is substantially flush with the outer wall 14 of the self-supporting body 4 within the concave channel 36.
The drainage hose 10 is either translucent or transparent, and therefore, when the external portion 30 of the drainage hose 10 is secured in an upright vertical position within the concave channel 36, the hose 10 functions as a telltale of the level 40 of liquid in the storage tank 6 (see FIG. 2). When the external portion 30 of the hose 10 is in the upright vertical position with the open end 34 supported near the top 20 of the self-supporting body 4, the liquid in the storage tank 6 is contained without the use of a flow control valve. As long as the water level 40 within the storage tank 6 remains below the height of the open end 34 of the external portion 30 of the drainage hose 10, the liquid in the storage tank 6 will be contained as shown in FIG. 2. To drain the storage tank 6 then, the open end 34 of the external portion 30 of the drainage hose 10 is removed from its secured position near the top 20 of the self-supporting body 4 and positioned at a level lower than the level of water 40 in the storage tank 6 (see FIG. 3). Thereby, drainage is accomplished without the need of a flow control valve.
The primary advantage of the container assembly 2 described hereinabove over prior art container assemblies for displaying and merchandising chilled beverages is that it provides a very attractive and relatively inexpensive container for accomplishing this function which is more convenient to use and less prone to leakage than prior assemblies utilized for this same purpose. It also has the advantage, because it controls the drainage of water from the tank 6 without the utilization of a valve, of being less subject to leakage and more convenient to drain than prior assemblies utilized for this same purpose.
Although the foregoing description and the drawings describe and illustrate a container assembly that fulfills the objects and advantages sought therefor, variations and modifications are contemplated as may be apparent to those skilled in the art and may be encompassed within the scope of the claims.
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A chilled beverage display bin for containing and displaying iced beverage products. The bin comprises a stand and a bucket or beverage display container contained internally of the stand. A translucent or transparent drainage hose is connected to the bottom of the bucket and extends through the stand into a channel formed on the exterior of the stand such that the hose functions as a telltale of the level of liquid in the container, and when removed from the channel, facilitates drainage of liquid from the container without the need for a flow control valve.
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This is a continuation of application Ser. No. 077,438 filed July 24, 1987 now abandoned.
FIELD OF THE INVENTION
The present invention relates to stretchable fabrics having enhanced thermal insulation properties, and which are particularly useful in thin, close-fitting outdoor apparel such as skiwear, gloves and work clothing.
BACKGROUND ART
Nonwoven thermally insulating elastically stretchable fabrics are taught in U.S. Pat. No. 4,551,378. Although these fabrics offer good insulating properties and comfort in wearing, the present invention makes possible even better insulating properties. Fabric as taught in U.S. Pat. No. 4,551,378 can be a component of fabric of the invention.
A different stretchable nonwoven thermal insulating fabric, which in one embodiment comprises a nonwoven web formed from thin fibrous layers laminated together, with the fibers comprising a polyester type copolymer containing butylene terephthalate, is taught in U.S. Pat. No. 4,438,172.
Another nonwoven thermal insulating fabric having stretch properties is commercially available under the trademark "Viwarm" from a Japanese manufacturer. The material is a spray-bonded, lightly needle-tacked nonwoven web of a blend of one- and three-denier single-component polyester fibers, the three-denier fiber having sufficient crimp to provide stretch properties. The product has a high "power stretch" (i.e., it requires a large force to stretch the fabric), and it does not have the combination of thermal insulating properties and low density offered in the present invention.
A different item of background prior art, relevant because it teaches blends of fibers useful in some embodiments of the present invention, is U.S. Pat. No. 4,118,531. This patent teaches blends of melt-blown microfibers and crimped staple textile fibers, which form lofty, high-insulating-value fabric or sheet material.
SUMMARY OF THE INVENTION
The present invention provides a new elastically stretchable fabric having a surprisingly high insulating value in view of its relative thinness, and which can be repeatedly stretched without losing its thermal insulative properties or its dimensional integrity. Briefly summarized, the new stretchable fabric, sometimes referred to herein as a "stretch fabric," comprises at least one elastically stretchable fibrous carrier web having substantially uniform stretch properties and carrying a thin coherent layer of microfibers coated on at least one surface of the carrier web. A coated layer of melt-blown microfibers is preferred and when deposited on the carrier web as a thin layer, preferably having a weight less than about 30 g/m 2 , greatly enhances the thermal insulating character of the fabric and functions as a substantially integral part of the fabric, e.g., stretches and retracts with the carrier web as the latter stretches and retracts and remains in adherent contact with the carrier web. It is preferred that the thermal insulating property of the fabric is at least 20% greater than the thermal insulating property of the carrier web, and more preferably at least 50% greater.
DETAILED DESCRIPTION
Carrier webs used in the present invention may comprise any elastically stretchable fibrous material, but preferably comprise a nonwoven web of bicomponent fibers bonded together by fusion of fibers at points of contact and thermally crimped in situ as is described in U.S. Pat. No. 4,551,378, which is incorporated herein by reference. The carrier webs should have substantially uniform low power stretch properties such as provided by the webs described in that patent. The carrier web (and finished fabric of the invention) preferably substantially recovers its original dimensions and insulation properties after repeated (i.e., 10 or more) extensions of 40% above its original dimension.
It is usually desirable that the bulk density of the carrier web be kept relatively low so as to provide good thermal insulating properties while keeping the web weight low. Weights of about 30 to 150 g/m 2 and densities ranging from about 0.005 to 0.020 g/cm 3 are preferable in the carrier web for most apparel applications. Also, carrier webs included in webs of the present invention are preferably permeable so as to facilitate the transfer of moisture through the total construction. Without adequate permeability, moisture will accumulate in the garment and adversely impact its ability to keep the wearer warm. Carrier webs should have a permeability (such as a Frazier permeability) of at least about 0.25 m 3 /sec/m 2 (50 ft 3 /min/ft 2 ) with a flow resistance of 124 Pa (1/2 inch water gauge pressure).
The microfiber-based coated layers of the present invention are typically comprised of fibers having an average diameter of less than about 10 micrometers. They can be prepared by a variety of techniques including solution-blowing or melt-blowing processes, but preferably are prepared by a melt-blowing process. A number of polymeric materials may be used for the preparation of the microfibers, including but not limited to polyethylene, polypropylene, polyethylene terephthalate (PET), and polyurethanes. Combinations of such polymers can be used as bicomponent fibers, e.g., as polyethylene/polypropylene or polypropylene/polyethylene terephthalate bicomponent fibers taught in microfiber form in U.S. Pat. No. 4,547,420, or also in some cases as blends. Coating weights are chosen to provide sufficient thermal insulation for the contemplated use of the finished fabric, but generally are at least about 5 g/m 2 and preferably at least 10 g/m 2 . The most preferred range, especially for melt-blown microfibers, is about 10-20.
Crimped staple textile fibers may be included in the microfiber-based coated layers in the fabrics of the present invention to achieve increased loft, but microfibers generally comprise at least 50 or 60 weight-percent of the coating.
The microfibers used in the invention are typically prepared by means of a melt-blowing process, for example, as taught by Wente, Van A., "Superfine Thermoplastic Fibers," in Industrial Engineering Chemistry, Vol. 48, pages 1342 et seq, (1956), or in Report No. 4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Superfine Organic Fibers" by Wente, Van A.; Boone, C. D. and Fluharty, E. L. The microfibers are typically collected directly onto the carrier web, as by interposing the webs in an air stream of the fibers. The carrier web can be held in either a relaxed or an extended configuration. Microfibers or mixtures of microfibers and staple textile fibers are able to penetrate into the web to a greater degree when the carrier web is in a stretched configuration and become more mechanically entwined, but good entwining is also achieved in the relaxed state. Melt-blown microfibers have good conformance and become well-entwined with the carrier web so as to remain adhered to the web with just mechanical entwining.
The present invention is further described by the following non-limiting examples.
EXAMPLES 1-6
A series of fabrics of the invention were prepared using as the carrier web a 34-g/m 2 -basis weight elastically stretchable nonwoven web as described in U.S. Pat. No. 4,551,378 made from staple highly eccentric sheath-core type bicomponent fibers having a polypropylene core and polyethylene sheath (Chisso ES fibers available from Chisso Corporation, Osaka, Japan). Polypropylene melt-blown microfiber coated layers were applied to the carrier web by feeding the carrier web under slight tension around a portion of the rotating collector drum of a melt-blowing apparatus similar to that described in U.S Pat. No. 4,118,531, which is incorporated herein by reference. A range of coating weights and collector/die distances were utilized in preparing a variety of samples, as described in Table I.
TABLE I______________________________________ Finished Finished Coating Collector Web Web Weight Distance Thickness DensityExample (g/m.sup.2) (cm) (cm) (g/m.sup.3)______________________________________1 Control -- .22 .0152 8 6 .261 .0133 8 14 .244 .0144 16 10 .28 .0125 24 6 .332 .0106 24 14 .285 .012______________________________________ Insulating % Thickness % Clo Value Increase IncreaseExample (Clo) (Clo/cm) From Coating From Coating______________________________________1 .34 1.545 Control --2 .451 1.73 18.6 32.63 .477 1.96 10.9 40.34 .53 1.89 28.0 56.05 .604 1.82 50.9 77.66 .582 2.04 29.5 71.2______________________________________
The power stretch (force required to stretch) of all the above samples fell within the range of 400 to 800 g for a 40% elongation of the sample.
EXAMPLE 7
A fabric of the invention similar to that of Example 4 was prepared, except that 6-denier polyethylene terephthalate staple fibers, 3.8 cm in length, were incorporated (using apparatus as taught in U.S. Pat. No. 4,118,531) into the coated layer in an amount of 8 g/m 2 in addition to the 16 g/m 2 of microfibers. The finished material had a thickness of 0.44 cm and a clo value of 0.826 which corresponded to a thickness increase of 100%, a clo increase of 142.9% and a clo/cm of 1.88.
EXAMPLES 8-11
A series of fabrics of the invention were prepared using a carrier web as used in Example 1 except that the latter had a basis weight of about 40 g/m 2 . Nylon melt-blown microfiber coatings were applied to the carrier web using conditions, and obtaining results, as described in Table II.
TABLE II______________________________________ Finished Finished Coating Collector Web Web Weight Distance Thickness DensityExample (g/m.sup.2) (cm) (cm) (g/m.sup.3)______________________________________8 15 8 0.21 0.02679 20 16 0.22 0.028210 29 24 0.23 0.029111 Control -- 0.22 0.0191______________________________________ Perme- % Thick- ability ness % CloInsulating (ft.sup.3 / Increase IncreaseValue min/ m.sup.3 / From FromExample (Clo) (Clo/cm) ft.sup.2) s/m.sup.2 Coating Coating______________________________________8 0.354 1.68 190 .965 (4.5)* 15.39 0.369 1.67 145 .737 0.0 20.210 0.428 1.86 80 .40 4.5 39.411 0.307 1.39 -- -- Control --______________________________________ *thickness decreased
EXAMPLES 12-15
A series of fabrics of the invention were prepared using a carrier web as described in Example 1 except that it had a basis weight of about 43 g/m 2 . Polyethylene terephthalate (PET) melt-blown microfibers were coated onto the carrier web under conditions, and with results, as described in Table III.
TABLE III______________________________________ Finished Finished Coating Collector Web Web Weight Distance Thickness DensityExample (g/m.sup.2) (cm) (cm) (g/m.sup.3)______________________________________12 14 8 0.25 0.022813 17 16 0.25 0.024414 25 24 0.28 0.025015 Control -- 0.22 0.0191______________________________________ Perme- % Thick- ability ness % CloInsulating (ft.sup.3 / Increase IncreaseValue min/ m.sup.3 / From FromExample (Clo) (Clo/cm) ft.sup.2) s/m.sup.2 Coating Coating______________________________________12 0.430 1.72 218 1.11 13.6 40.113 0.408 1.64 226 1.15 13.6 32.914 0.474 1.53 170 .86 27.3 54.415 0.307 1.39 -- -- Control --______________________________________
EXAMPLES 16-18
A series of fabrics of the invention were prepared using a carrier web as described in Examples 1-6 except that it had a basis weight of about 84.4 g/m 2 .
TABLE IV______________________________________ Finished Finished Coating Collector Web Web Weight Distance Thickness DensityExample (g/m.sup.2) (cm) (cm) (g/m.sup.3)______________________________________16 14 16 0.457 0.021517 8.2 16 0.473 0.019618 Control -- 0.420 0.0201______________________________________ Perme- % Thick- ability ness % CloInsulating (ft.sup.3 / Increase IncreaseValue min/ m.sup.3 / From FromExample (Clo) (Clo/cm) ft.sup.2) s/m.sup.2 Coating Coating______________________________________16 0.780 1.71 218 1.11 8.8 21.117 0.774 1.64 229 1.63 12.6 15.518 0.644 1.53 52 .26 Control --______________________________________
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An elastically stretchable fabric having enhanced thermal insulation properties comprising at least one elastically stretchable carrier web having substantially uniform stretch properties and a thin coherent coated layer of melt-blown microfibers carried on at least one surface of the carrier web, said melt-blown microfibers being selected from the group consisting of polypropylene, polyethylene, polyurethane, polyethylene terephthalate or mixtures thereof.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase Application of PCT/EP2014/059929, filed May 15, 2014, which claims priority to European Patent Application No. 13168793.1, filed May 22, 2Q13, the contents of such applications being incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates to a method for joining concealed workpiece parts by means of an energy beam.
BACKGROUND OF THE INVENTION
[0003] A joining technique is known in which two parts are to be joined to each other in an area in which one part is lying on the other, such that the joining seam for connecting the two parts has to be produced through the part lying on top, wherein the relative position of the two parts with respect to each other is usually determined by gauging the parts and gauging the positions of the two parts relative to each other in the joining position.
[0004] Once the two parts are calibrated in their joining position in the joining station, on energy beam can travel a predetermined joining trajectory along the joining contour and join the two parts, wherein the joining seam may be placed in a position in which a secure and permanent connection between the workpiece parts is not ensured, for example due to the accumulation of permitted production tolerances on the workpiece parts. These faulty workpieces can be detected by quality control and filtered out or submitted for reworking. This additional process step takes time and therefore increases costs.
[0005] DE 10 2007 062 535 A1, which is incorporated by reference, discloses a method for joining two workpiece parts using a beam, wherein a joining contour on a lower workpiece part is concealed by an upper workpiece part, such that the joining seam for joining the lower workpiece part and upper workpiece part has to be placed without being able to monitor in-line whether the joining seam has been correctly placed. The method includes gauging and aligning the workpiece parts before beginning the process of joining using a beam.
[0006] Gauging and aligning each workpiece is time-consuming and can therefore for example prolong a cycle time in a production line. This prolonged cycle time leads to a lower throughput per unit time and therefore increases costs.
SUMMARY OF THE INVENTION
[0007] There is therefore a need for a method using which it is possible to detect a position of a concealed joining contour before beginning the joining process, without having to gauge the workpieces in a complicated and/or costly way.
[0008] One aspect of the invention relates to a method for joining concealed workpiece parts by means of an energy beam, wherein in a first step, a lower workpiece part and an upper workpiece part are positioned relative to each other, wherein the upper workpiece part contacts the lower workpiece part over an area or linearly along a joining contour of the lower workpiece part when they are positioned, thereby concealing the joining contour. A target profile of the joining contour is known, in relation to a co-ordinate system, in a controller for the energy beam.
[0009] The upper workpiece part and the lower workpiece part together form a common joining contact, and the energy beam is directed onto an upper side of the upper workpiece part, which faces away from the lower workpiece part, and is moved along the joining contour or joining contact by a controller, in order to join the upper workpiece part to the joining contour of the lower workpiece part in a material lock.
[0010] Before beginning the actual process of joining the upper workpiece part to the lower workpiece part, an exploratory seam is produced on the upper side of the upper workpiece part using the energy beam, for detecting the joining contour or its exact position and alignment, respectively.
[0011] By means of a detector, a boundary is detected at which a surface area of the upper workpiece part which does not have any contact with the lower workpiece part borders a surface area of the upper workpiece part which does have contact with the joining contour. The controller registers a position of the boundary and compares it with a target position of the boundary which is stored in the controller.
[0012] If the controller determines that an actual position of the boundary deviates from the target position stored in the controller, a target profile of the energy beam along the joining contour is corrected.
[0013] The exploratory seam can extend from where it begins to where a first boundary is detected and beyond. The exploratory seam can in particular extend from the surface area of the upper workpiece part which does not have any contact with the lower workpiece part, over the surface area of the upper workpiece part which does have contact with the joining contour, into another surface area of the upper workpiece part which does not have any contact with the lower workpiece part, i.e. the exploratory seam can comprise a first boundary when the exploratory seam transitions from the surface area of the upper workpiece part which does not have any contact with the lower workpiece part into the surface area of the upper workpiece part which does have contact with the joining contour, and a second boundary on an opposite side of the upper workpiece part in contact with the joining contour when the exploratory seam transitions from the surface area of the upper workpiece part which does have contact with the joining contour into another surface area of the upper workpiece part not in contact with the joining contour.
[0014] A parameter which is characteristic of the exploratory seam, in particular a physical or chemical parameter, can be detected and monitored by the detector. Such a parameter can for example be a heat energy field of the exploratory welding seam, a current rating, a voltage or a gas flow rate.
[0015] The detector can for example be an optical detector which follows the energy beam at a short distance or is arranged to the side of the energy beam. The detector can for example detect a heat energy distribution in the exploratory seam even while the energy beam is producing the exploratory seam.
[0016] The value/s of the parameter/s which is/are detected by the detector can change abruptly at the boundary. This abrupt change indicates that the boundary or a boundary point from the surface area of the upper workpiece part which does not have any contact with the lower workpiece part to a surface area of the upper workpiece part which does have contact with the joining contour is situated at this location, wherein the detector for example detects an edge of the joining contour or another area of the joining contour which in particular abuts the upper workpiece part in a line, i.e. the exploratory seam extends on the upper side of the upper workpiece part which faces the energy beam, up to and into the surface area of the upper workpiece part which conceals the joining contour formed by or on the lower workpiece part.
[0017] The detected abrupt change in the parameter/s at the boundary or boundary point can be identified and registered by the controller, wherein “registered” means that the boundary is defined with respect to its x, y and z direction in a for example Cartesian co-ordinate system in which the dimensions and directions of the upper workpiece part and the lower workpiece part are known.
[0018] In order to obtain as exact a position as possible, the controller can comprise a filter algorithm which processes the value(s) of the parameter(s) detected by the detector, in order to at least partially eliminate known distortions in the data captured.
[0019] In particular in order to detect the exact position of a convoluted or angular joining contour below the upper workpiece part, it can be advantageous to produce at least two exploratory seams on the upper side of the upper workpiece part by means of the energy beam, at least one of which extends from the surface area of the upper workpiece part which does not have any contact with the lower workpiece part, over the surface area of the upper workpiece part which does have contact with the joining contour, into another surface area of the upper workpiece part which does not have any contact with the lower workpiece part, and the other of which extends at least from the surface area of the upper workpiece part which does not have any contact with the lower workpiece part into the surface area of the upper workpiece part which does have contact with the joining contour. Thus, at least two boundaries are detected by the detector, and actual positions of at least two boundaries or boundary points are registered by the controller. The actual positions of the boundaries can then be compared with the target positions of the boundaries which are stored in the computer, such that an actual profile of a concealed convoluted or angled joining contour of a workpiece can be determined.
[0020] Instead of the two exploratory seams, it is also possible for three or more exploratory seams to be placed by the energy beam and for more than three boundaries to be detected by the detector and registered by the controller. However, since each additional exploratory seam means increased material and/or energy consumption and thus takes time and therefore costs money, a necessary number of exploratory seams can be determined for each workpiece and each joining contour, and the beginning, direction and length of each joining seam can be defined, in advance of applying the method.
[0021] Once all the predetermined boundaries have been registered by the controller, the controller can determine the actual position of the joining contour concealed by the upper workpiece part, compare it with a target position of the joining contour and—if the actual position and target position of the joining contour deviate—correct a joining trajectory of the energy beam which is stored in the controller. The energy beam can then be guided by the controller on the upper side of the upper workpiece part along the actual position of the joining contour, in order to connect the upper workpiece part to the lower workpiece part in the concealed joining contour.
[0022] Alternatively, the movement of the energy beam can be corrected after a first boundary or a first and second boundary has/have been detected and registered, and the exploratory seam can transition into a joining seam along the joining contour without interrupting the movement of the energy beam, i.e. the controller compares the detected and registered actual position with the predetermined target position of the joining contour, and as applicable corrects for a first time the profile of the energy beam along the joining contour in the target position which is stored in the controller, even as it compares the actual position with the target position of the first boundary at which the surface area of the upper workpiece part which does not have any contact with the lower workpiece part switches to the surface area of the upper workpiece part which does have contact with the joining contour.
[0023] If, while the upper workpiece part is being joined to the lower workpiece part, the detector detects that the energy beam is switching from the surface area of the upper workpiece part which does have contact with the joining contour to a surface area of the upper workpiece part which does not have any contact with the lower workpiece part, the profile of the energy beam along the joining contour in the target position—which has already been corrected once in the controller—is corrected a second time. This process can be repeated until the energy beam is only then moved in the surface area of the upper workpiece part which does have contact with the joining contour.
[0024] This means that the energy beam is stabilised to an actual profile of the joining contour by the controller in a meandering movement.
[0025] The energy beam can exhibit a higher or lower energy for producing the joining seam than for producing the exploratory seam. The exploratory seam can be produced using an energy at which it is reliably ensured that at least one characteristic parameter of the exploratory seam changes abruptly when the energy beam switches from the surface area of the upper workpiece part which does not have any contact with the lower workpiece part into the surface area of the upper workpiece part which does have contact with the joining contour, or vice versa. If the exploratory seam transitions into the joining seam without interruption, the energy of the energy beam can for example be increased or reduced from an exploratory seam energy value to a joining seam energy value, when the detector detects the first boundary or at a later time which is for example predetermined in the controller.
[0026] Alternatively or additionally, the speed at which the energy beam is moved over the upper side of the upper workpiece part which faces it can be different when the exploratory seam is being produced and when the joining seam is being produced. The energy beam can for example be moved at a higher or lower speed when the exploratory seam is being produced than when the joining seam is being produced.
[0027] It generally holds during the entire method that boundaries are detected by the detector, the positions of the boundaries are registered by the controller and compared with the positions of the boundaries which are stored in the controller, and that if the position of at least one of the boundaries deviates, the movement of the energy beam along the joining contour is corrected in order to guide the energy beam into or back into the surface area of the upper workpiece part which does have contact with the joining contour.
[0028] The exploratory seam can be produced obliquely or transverse to the joining contour which is stored in the controller.
[0029] In particular when the exploratory seam which extends substantially transverse to the joining contour is being produced, the energy beam can connect or tack the upper workpiece part, at least at points, to the joining contour of the lower workpiece part in a material lock. The upper workpiece part is thus connected to the joining contour at points and defined for the subsequent joining process.
[0030] The detector can be a detector of a system for monitoring the quality of joining seams. The quality monitoring system is in particular one which can monitor the quality of a joining seam in-line, wherein “in-line” means that quality control is performed at substantially the same time as the joining seam or exploratory seam, respectively, is produced.
[0031] The joining method can be a welding method, a soldering method or an adhering method. In the adhering method, an adhesive can be used which is deposited onto the joining contour and activated by the heat energy of the energy beam, wherein in the adhering method and the soldering method, the energy of the energy beam for producing the exploratory seam can be sufficient to activate the adhesive or melt the solder, i.e. the increase in the energy of the energy beam described above with respect to the joining method can be omitted in the adhering method and/or soldering method if the energy beam transitions from the exploratory seam into the joining seam without interruption and is stabilised to the joining contour or to the surface area of the upper side of the upper workpiece part which contacts the joining contour, respectively, in a meandering form.
[0032] The welding method can for example be an electric arc welding method using a melting electrode (MIG, MAG), a laser welding method, a high-frequency induction welding method, a plasma welding method or another suitable welding method.
[0033] The method described can in principle be advantageously used to join any two workpiece parts in a concealed seam, wherein the upper workpiece part and the lower workpiece part can be formed from the same material, for example metal or plastic. The metal can be inter alia a thin-walled steel casting or a metal casting. It is however also possible for the upper workpiece part to be formed from a different material to the lower workpiece part comprising the joining contour.
[0034] The lower workpiece part can for example be a part of a motor vehicle structure or a motor vehicle body, and the upper workpiece part can for example be a part of a motor vehicle structure or a motor vehicle body, i.e. the method can advantageously be used in a production line for mass-produced articles such as motor vehicles.
[0035] In order to join the lower workpiece part to the upper workpiece part, the lower workpiece part and/or the upper workpiece part can be placed in a joining station and preferably fixed relative to each other, in the joining station or before they are placed in the joining station, wherein the joining station is a stationary joining station or a joining station which is connected to a robot arm and spatially moved by the robot arm during joining.
[0036] The joining station can be formed such that the lower workpiece part and the upper workpiece part lie in a known position in a co-ordinate system, for example a Cartesian co-ordinate system, after they have been placed in the joining station and/or fixed. This known position can be inputted into the controller and stored in the controller, i.e. the controller knows the theoretical position and the theoretical profile of the joining contour, which is concealed by the upper workpiece part, on the lower workpiece part and can guide the energy beam along the joining contour. Due for example to an accumulation of permitted tolerances on the upper workpiece part and the lower workpiece part, the joining contour may not lie at the target position which is stored in the controller. Thus, it may be that the controller does not reliably guide the energy beam along the joining contour and that the joining seam produced thus exhibits defects. In order to locate the concealed joining contour or its actual position, respectively, the exploratory seam can be produced on the upper side of the upper workpiece part by means of the energy beam, as described above.
[0037] In order to produce the exploratory seam and the joining seam, a beam-emitting part of a system which produces the high-energy beam and/or the detector of the quality control device can be affixed to a robot arm and form a combined joining and control tool. The robot arm can be able to be freely moved spatially.
[0038] Joining the lower workpiece part to the upper workpiece part can be performed as an uninterrupted joining process if the parts to be joined are respectively connected to a robot arm, such that they can be freely moved spatially, and the combined joining and control tool is a stationary tool or is connected to another robot arm, such that it can be freely moved spatially.
[0039] A method and device for joining components without using a clamping frame is known from WO 2009/140977, which is incorporated by reference, an international application of the Applicant's which is explicitly referenced here.
[0040] Another aspect of the invention relates to a computer program for performing the method described above.
[0041] A computer can feature: a digital microprocessor unit (CPU) with a data connection to a storage system and a bus system; a working memory (RAM); and a storage means. The CPU is designed to: implement commands which are embodied as a program which is stored in a storage system; detect input signals from the data bus; and emit output signals to the data bus. The storage system can feature various storage media such as optical, magnetic, solid-state and other non-volatile media, on which a corresponding computer program for performing the method and the advantageous embodiments is stored. The program can be designed such that it represents and/or is capable of performing the methods described here, such that the CPU can perform the steps of such methods and can therefore control the energy beam of the joining device.
[0042] A computer program which is suitable for performing a method comprises program code means for performing all the steps of the method when the program is run on a computer.
[0043] The computer program can be inputted by simple means into controllers which already exist, and can be used to control a method for joining a workpiece along a concealed joining seam.
[0044] Another aspect of the invention relates to a computer program product comprising program code means which are stored on a computer-readable data storage medium, in order to be able to perform the method described above when the program code means are run on a computer.
[0045] The computer program product can also be integrated into controllers as a retrofit option.
[0046] It holds for the entire description and the claims that the expression “a(n)” is used as an indefinite article and does not limit the number of parts to one. Where “a(n)” is intended to have the meaning of “only one”, this will be understood by the person skilled in the art from the context or is unambiguously disclosed by the use of suitable expressions such as for example “one”.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] An example embodiment is described below in more detail on the basis of the drawings, which show:
[0048] FIG. 1 a workpiece with two exploratory seams;
[0049] FIG. 2 the workpiece of FIG. 1 in a perspective lateral view;
[0050] FIG. 3 a workpiece with an alternative exploratory seam;
[0051] FIG. 4 a detailed view of an energy beam and a detector, when placing an exploratory seam;
[0052] FIG. 5 a stationary joining station with a joining robot; and
[0053] FIG. 6 an example of a measurement curve when detecting a boundary.
DETAILED DESCRIPTION OF THE INVENTION
[0054] FIG. 1 shows a workpiece 1 consisting of an upper workpiece part 2 and a lower workpiece part 3 . The upper workpiece part 2 lies on the lower workpiece part 3 , such that an energy beam 10 shown in FIG. 4 cannot directly process the joining contour 4 along which the upper workpiece part 2 contacts the lower workpiece part 3 .
[0055] In order to be able to determine an exact position of the lower workpiece part 3 relative to the upper workpiece part 2 , two exploratory seams 5 , 6 have been produced—in the example embodiment, by means of the energy beam 10 —on an upper side 2 a of the upper workpiece part 2 which faces the energy beam 10 .
[0056] Since the approximate position of the lower workpiece part 3 relative to the upper workpiece part 2 is known with regard to general joining tolerances, the energy beam 10 can place the beginning of the exploratory seam 5 ; 6 on the upper side 2 a of the upper workpiece part 2 in an area which already lies near the joining contour 4 , wherein the exploratory seam 5 ; 6 is placed substantially transverse to the joining contour 4 or in the area of a corner or curve of the joining contour 4 , such that it can detect the joining contour 4 before and after the corner.
[0057] When the exploratory seam 5 ; 6 is being produced, the exploratory seam 5 ; 6 or at least one typical parameter of the exploratory seam 5 ; 6 , respectively, can be monitored by a detector 11 shown in FIG. 4 . When the exploratory seam 5 ; 6 switches from a surface area A 1 of the upper workpiece part 2 which does not have any contact with the lower workpiece part 3 to a surface area A 2 in which the upper workpiece part 2 contacts the joining contour 4 , the at least one parameter of the exploratory seam 5 ; 6 being monitored by the detector 11 changes abruptly. The same holds for the reverse case, when the exploratory seam 5 ; 6 switches from the surface area A 2 to the surface area A 1 .
[0058] This means that the detector 11 can detect boundary or contact points 7 , 8 in which the exploratory seam 5 ; 6 switches from the surface area A 1 or A 2 to the surface area A 2 or A 1 . Since the position of the lower workpiece part 3 and the upper workpiece part 2 is known in a reference system, such as a Cartesian co-ordinate system, of for example a joining station 9 , the positions of the contact points 7 , 8 can be detected exactly. An actual position of the lower workpiece part 3 with respect to the upper workpiece part 2 then follows from the positions of the contact points 7 , 8 .
[0059] Using the known positions of the contact points 7 , 8 of the exploratory seam 5 ; 6 or exploratory seams 5 , 6 , a target position of the lower workpiece part 3 with respect to the upper workpiece part 2 or a predetermined target joining trajectory of the energy beam 10 , respectively, which is stored in a computer 12 which is not shown in FIG. 1 , is corrected to an actual joining trajectory for the energy beam 10 .
[0060] FIG. 2 shows the workpiece 1 of FIG. 1 in a perspective view. The position of the joining contour 4 of the lower workpiece part 3 or the area in which the upper workpiece part 2 lies on the joining contour 4 of the lower workpiece part 3 , respectively, is shown by the broken lines. The exploratory seams 5 , 6 extend from a surface area A 1 in which the upper workpiece part 2 does not contact the lower workpiece part 3 , over a surface area A 2 in which the upper workpiece part 2 contacts the joining contour 4 of the lower workpiece part 3 , into another surface area A 1 , wherein the contact points 7 , 8 at the boundaries between a surface area A 1 and a surface area A 2 and between a surface area A 2 and a surface area A 1 are detected by the detector 11 (not shown), and a current position and alignment of the lower workpiece part 3 relative to the upper workpiece part 2 is calculated from an actual position of the contact points 7 , 8 , as already described with respect to FIG. 1 . This calculated position and alignment of the lower workpiece part 3 then serves as a basis for calculating a joining trajectory to be travelled by the energy beam 10 (not shown).
[0061] FIG. 3 shows an alternative exploratory seam 5 ′. The exploratory seam 5 ′ is produced at an acute angle to the joining contour 4 . If the detector 11 then detects a contact point 7 ; 8 , the target joining trajectory of the energy beam 10 which is stored in the computer 12 is immediately corrected, and the energy beam 10 pivots towards the actual position of the joining contour 4 . If, shortly thereafter, the detector 11 detects another contact point 7 ; 8 , this leads to another correction of the joining trajectory of the energy beam 10 . This process can be repeated multiple times, until the energy beam 10 is stabilised to the correct actual joining trajectory for joining the workpiece 1 by the meandering movement, as shown in FIG. 3 .
[0062] FIG. 4 shows an exploratory seam 5 ′ being produced using the energy beam 10 , and at least one typical parameter of the exploratory seam 5 ′ being simultaneously monitored by the detector 11 .
[0063] In the example embodiment shown, the energy beam 10 is a laser beam, and the detector 11 is an optical detector 11 of a quality assurance device using which the quality of a welding seam can be monitored in-line, i.e. while the welding seam is being produced or shortly after it has been produced.
[0064] In the example embodiment, the detector 11 and a device 10 a which emits the energy beam 10 are affixed to a common tool head 14 which, as shown in FIG. 5 , is affixed to a robot arm 15 of an industrial robot 16 . The robot arm 15 can move the combined joining and detection tool spatially, both along an exploratory seam and along a joining seam in accordance with FIGS. 1 and 3 .
[0065] The exploratory seams 5 , 6 of FIG. 1 are produced first and the energy beam 10 and the detector 11 are then moved to a predetermined starting point for joining the upper workpiece part 2 to the joining contour 4 of the lower workpiece part 3 , while in the case of the alternative exploratory seam 5 ′ shown in FIG. 3 , the energy beam 10 transitions into the joining seam without interruption.
[0066] The energy beam 10 can connect the upper workpiece part 2 to the joining contour 4 of the lower workpiece part 3 at points even as it produces the exploratory seams 5 , 6 of FIG. 1 . The workpiece 1 is thus already pre-fixed in a material lock and can be joined, in its pre-fixed position, along the joining contour 4 .
[0067] The energy beam 10 can produce the exploratory seam 5 ; 6 and the joining seam using the same energy and at the same speed. The exploratory seam 5 ; 6 can however also be produced using an energy which is greater than or less than the energy for producing the joining seam and/or at a speed which is less than or greater than the speed for producing the joining seam.
[0068] FIG. 5 shows an example of an arrangement comprising a stationary joining station 9 and an industrial robot 16 . The industrial robot 16 comprises a robot arm 15 which bears a tool head 14 . The detector 11 and the device 10 a which emits the energy beam 10 are connected to the tool head 14 .
[0069] The device 10 a is connected to an energy source 17 , which produces or provides the energy for the energy beam 10 , via a line L E and to a computer 12 , which for example controls the movements of the energy beam 10 and regulates the energy of the energy beam 10 , via a line L 1 .
[0070] The detector 11 is connected to the computer 12 via a line L 2 and transmits the captured parameter data which are typical of the welding seam, irrespective of whether it is an exploratory seam 5 ; 6 or a joining seam, to the computer 12 .
[0071] The computer 12 comprises a memory 13 in which a target position of the upper workpiece part 2 with respect to the lower workpiece part 3 and a target joining trajectory for the energy beam 10 for joining the upper workpiece part 2 to the lower workpiece part 3 is stored for the workpiece 1 to be processed. The computer 12 can compare the data captured by the detector 11 with the target position data of the workpiece 1 . If the computer 12 determines, on the basis of the boundaries or contact points 7 , 8 detected by the detector 11 , that the detected actual position of the joining contour 4 on the lower workpiece part 3 deviates from the target position of the joining contour or lower workpiece part 3 , respectively, which is stored in the computer 12 , it can correct the target joining trajectory for the energy beam 10 by means of an algorithm which is stored in the computer 12 , such that the energy beam 1 Q can then be guided by the computer 12 along the detected actual profile of the joining contour 4 .
[0072] FIG. 6 shows a typical profile of a parameter of the exploratory seam 5 ; 6 , as detected by the detector 11 , at the boundary between the surface area A 1 of the upper workpiece part 2 which does not have any contact with the lower workpiece part 3 and the surface area A 2 in which the upper workpiece part 2 contacts the joining contour 4 of the lower workpiece part 3 . The parameter detected by the detector 11 changes abruptly at the boundary between the surface area A 1 and the surface area A 2 .
[0073] Since the point on the upper side 2 a of the upper workpiece part 2 at which the energy beam 10 begins producing the exploratory seam 5 ; 6 is detected and registered or is predetermined, respectively, by the computer 12 and is stored in the computer 12 , and since the direction and speed in/at which the energy beam 10 is moved when producing the exploratory seam 5 ; 6 are predetermined and are stored in the computer 12 , the computer 12 can register the contact point 7 ; 8 on the basis of this abrupt change in the parameter and can calculate a correction for the joining trajectory of the energy beam 10 on the basis of the registered contact point 7 ; 8 or on the basis of multiple registered contact points 7 , 8 .
[0074] Although a number of possible embodiments of the invention have been disclosed in the preceding description, it will be appreciated that numerous other variants of embodiments exist through possible combinations of any of the technical features and embodiments mentioned and also any of the technical features and embodiments which are obvious to the person skilled in the art. It will also be appreciated that the example embodiments are to be understood merely as examples which in no way limit the scope of protection, applicability or configuration. The preceding description is instead intended to illustrate to the person skilled in the art a suitable way of realising at least one example embodiment. It will be appreciated that numerous changes with respect to the function and arrangement of the elements can be made to an example embodiment, without departing from the scope of protection disclosed in the claims and its equivalents.
LIST OF REFERENCE SIGNS
[0000]
1 workpiece
2 upper workpiece part
2 a upper side
3 lower workpiece part
4 joining contour
5 , 5 ′ exploratory seam
6 exploratory seam
7 contact point, boundary
8 contact point, boundary
9 joining station
10 energy beam
10 a beam-emitting device
11 detector
12 computer
13 memory
14 tool head
15 robot arm
16 industrial robot
17 energy source
A 1 surface area
A 2 surface area
L 1 line
L 2 line
L E line
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A method for joining concealed workpiece parts by an energy beam, wherein a lower workpiece part and an upper workpiece part are positioned relative to each other; the upper workpiece part contacts the lower workpiece part along a joining contour; the energy beam is directed onto an upper side of the upper workpiece part, moved along the joining contour by a controller, in order to join the upper workpiece part to the joining contour; an exploratory seam is produced on the upper work piece part, for detecting the joining contour; a detector detects a boundary at which a surface area of the upper work piece part borders a surface area of the upper work piece part which does have contact with the joining contour; the controller registers a position of the boundary and compares it with a target position of the boundary which is stored in the controller.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 11/951,802, filed 6 Dec. 2007 (issuing as U.S. Pat. No. 7,841,410 on 30 Nov. 2010), which is a continuation in part of U.S. patent application Ser. No. 11/749,591, filed 16 May 2007 (issued as U.S. Pat. No. 7,607,481 on 27 Oct. 2009), each of which is hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus that is of particular utility in cementing operations associated with oil and gas well exploration and production. More specifically the present invention provides an improvement to cementing operations and related operations employing a plug or ball dropping head.
2. General Background of the Invention
Patents have issued that relate generally to the concept of using a plug, dart or a ball that is dispensed or dropped into the well or “down hole” during oil and gas well drilling and production operations, especially when conducting cementing operations. The following possibly relevant patents are incorporated herein by reference. The patents are listed numerically. The order of such listing does not have any significance.
TABLE
Pat. No.
TITLE
ISSUE DATE
3,828,852
Apparatus for Cementing Well Bore Casing
Aug. 13, 1974
4,427,065
Cementing Plug Container and Method of
Jan. 24, 1984
Use Thereof
4,624,312
Remote Cementing Plug Launching System
Nov. 25, 1986
4,671,353
Apparatus for Releasing a Cementing Plug
Jun. 09, 1987
4,722,389
Well Bore Servicing Arrangement
Feb. 02, 1988
4,782,894
Cementing Plug Container with Remote
Nov. 08, 1988
Control System
4,854,383
Manifold Arrangement for use with a Top
Aug. 08, 1989
Drive Power Unit
4,995,457
Lift-Through Head and Swivel
Feb. 26, 1991
5,095,988
Plug Injection Method and Apparatus
Mar. 17, 1992
5,236,035
Swivel Cementing Head with Manifold
Aug. 17, 1993
Assembly
5,293,933
Swivel Cementing Head with Manifold
Mar. 15, 1994
Assembly Having Remove Control Valves
and Plug Release Plungers
5,435,390
Remote Control for a Plug-Dropping Head
Jul. 25, 1995
5,758,726
Ball Drop Head With Rotating Rings
Jun. 02, 1998
5,833,002
Remote Control Plug-Dropping Head
Nov. 10, 1998
5,856,790
Remote Control for a Plug-Dropping Head
Jan. 05, 1999
5,960,881
Downhole Surge Pressure Reduction System
Oct. 05, 1999
and Method of Use
6,142,226
Hydraulic Setting Tool
Nov. 07, 2000
6,182,752
Multi-Port Cementing Head
Feb. 06, 2001
6,390,200
Drop Ball Sub and System of Use
May 21, 2002
6,575,238
Ball and Plug Dropping Head
Jun. 10, 2003
6,672,384
Plug-Dropping Container for Releasing a
Jan. 06, 2004
Plug Into a Wellbore
6,904,970
Cementing Manifold Assembly
Jun. 14, 2005
7,066,249
Cementing Manifold Assembly
Jul. 27, 2006
BRIEF SUMMARY OF THE INVENTION
The present invention provides an improved method and apparatus for use in cementing and like operations, employing a plug or ball dropping head of improved configuration.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIGS. 1A , 1 B, 1 C are partial sectional elevation views of the preferred embodiment of the apparatus of the present invention wherein line A-A of FIG. 1A matches line A-A of FIG. 1B , and line B-B of FIG. 1B matches line B-B of FIG. 1C ;
FIG. 2 is a partial, sectional, elevation view of the preferred embodiment of the apparatus of the present invention;
FIG. 3 is a partial, sectional, elevation view of the preferred embodiment of the apparatus of the present invention;
FIG. 4 is a sectional view taken long lines 4 - 4 of FIG. 2 ;
FIG. 5 is a sectional view taken along lines 5 - 5 of FIG. 3 ;
FIG. 6 is a partial perspective view of the preferred embodiment of the apparatus of the present invention;
FIG. 7 is a sectional elevation view of the preferred embodiment of the apparatus of the present invention and illustrating a method step of the present invention;
FIG. 8 is a sectional elevation view of the preferred embodiment of the apparatus of the present invention and illustrating a method step of the present invention;
FIG. 9 is an elevation view of the preferred embodiment of the apparatus of the present invention and illustrating the method of the present invention;
FIG. 10 is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of FIG. 10 matches line A-A of FIG. 9 ;
FIG. 11 is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of FIG. 11 matches line A-A of FIG. 9 ;
FIG. 12 is a sectional elevation view illustrating part of the method of the present invention;
FIG. 13 is a sectional elevation view illustrating part of the method of the present invention;
FIG. 14 is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of FIG. 14 matches line A-A of FIG. 9 ;
FIG. 15 is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of FIG. 15 matches line A-A of FIG. 9 ;
FIG. 16 is a sectional elevation view illustrating part of the method of the present invention;
FIG. 17 is a partial perspective view of the preferred embodiment of the apparatus of the present invention;
FIG. 18 is a partial view of the preferred embodiment of the apparatus of the present invention and showing a ball valving member;
FIG. 19 is a partial side view of the preferred embodiment of the apparatus of the present invention and showing an alternate construction for the ball valving member;
FIG. 20 is a partial view of the preferred embodiment of the apparatus of the present invention and showing a ball valving member;
FIG. 21 is a partial side view of the preferred embodiment of the apparatus of the present invention and showing an alternate construction for the ball valving member;
FIG. 22 is a sectional view of the preferred embodiment of the apparatus of the present invention showing an alternate sleeve arrangement;
FIG. 23 is a sectional view of the preferred embodiment of the apparatus of the present invention showing an alternate sleeve arrangement;
FIG. 24 is a fragmentary view of the preferred embodiment of the apparatus of the present invention;
FIG. 25 is a fragmentary view of the preferred embodiment of the apparatus of the present invention; and
FIG. 26 is a fragmentary view of the preferred embodiment of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 9 shows generally an oil well drilling structure 10 that can provide a platform 11 such as a marine platform as shown. Such platforms are well known. Platform 11 supports a derrick 12 that can be equipped with a lifting device 21 that supports a top drive unit 13 . Such a derrick 12 and top drive unit 13 are well known. A top drive unit can be seen for example in U.S. Pat. Nos. 4,854,383 and 4,722,389 which are incorporated herein by reference.
A flow line 14 can be used for providing a selected fluid such as a fluidized cement or fluidized setable material to be pumped into the well during operations which are known in the industry and are sometimes referred to as cementing operations. Such cementing operations are discussed for example in prior U.S. Pat. Nos. 3,828,852; 4,427,065; 4,671,353; 4,782,894; 4,995,457; 5,236,035; 5,293,933; and 6,182,752, each of which is incorporated herein by reference.
A tubular member 22 can be used to support plug dropping head 15 at a position below top drive unit 13 as shown in FIG. 9 . String 16 is attached to the lower end portion of plug dropping head 15 .
In FIG. 9 , the platform 11 can be any oil and gas well drilling platform such as a marine platform shown in a body of water 18 that provides a seabed or mud line 17 and water surface 19 . Such a platform 11 provides a platform deck 20 that affords space for well personnel to operate and for the storage of necessary equipment and supplies that are needed for the well drilling operation.
A well bore 23 extends below mud line 17 . In FIGS. 10 and 11 , the well bore 23 can be surrounded with a surface casing 24 . The surface casing 24 can be surrounded with cement/concrete 25 that is positioned in between a surrounding formation 26 and the surface casing 24 . Similarly, a liner or production casing 32 extends below surface casing 24 . The production casing 32 has a lower end portion that can be fitted with a casing shoe 27 and float valve 28 as shown in FIGS. 10-16 . Casing shoe 27 has passageway 30 . Float valve 28 has passageway 29 .
The present invention provides an improved method and apparatus for dropping balls, plugs, darts or the like as a part of a cementing operation. Such cementing operations are in general known and are employed for example when installing a liner such as liner 32 . In the drawings, arrows 75 indicate generally the flow path of fluid (e.g. cement, fluidized material or the like) through the tool body 34 . In that regard, the present invention provides an improved ball or plug or dart dropping head 15 that is shown in FIGS. 1-8 and 10 - 17 . In FIGS. 1A , 1 B, 1 C and 2 - 8 , ball/plug dropping head 15 has an upper end portion 31 and a lower end portion 33 . Ball/plug dropping head 15 provides a tool body 34 that can be of multiple sections that are connected together, such as with threaded connections. In FIGS. 1A-1C , the tool body 34 includes sections 35 , 36 , 37 , 38 , 39 . The section 35 is an upper section. The section 39 is a lower section.
Ball/plug dropping head 15 can be pre-loaded with a number of different items to be dropped as part of a cementing operation. For example, in FIGS. 1A , 1 B, 1 C there are a number of items that are contained in ball/plug dropping head 15 . These include an upper, larger diameter ball dart 40 , 41 and smaller diameter ball 42 . In FIGS. 18-26 , an alternate embodiment is shown which enables very small diameter balls, sometimes referred to as “frac-balls” 102 (which can have a diameter of between about ½ and ⅝ inches) to be dispensed into the well below toll body 34 .
The tool body 34 supports a plurality of valving members at opposed openings 90 . The valving members can include first valving member 43 which is an upper valving member. The valving members can include a second valving member 44 which is in between the first valving member 43 and a lower or third valving member 45 . Valving member 43 attaches to tool body 34 at upper opening positions 61 , 62 . Valving member 44 attaches to tool body 34 at middle opening positions 63 , 64 . Valving member 45 attaches to tool body 43 at lower opening positions 65 , 66 .
Threaded connections 46 , 47 , 48 , 49 can be used for connecting the various body sections 35 , 36 , 37 , 38 , 39 together end to end as shown in FIGS. 1A , 1 B, 1 C. Tool body 34 upper end 31 is provided with an internally threaded portion 50 for forming a connection with tubular member 22 that depends from top drive unit 13 as shown in FIG. 9 . A flow bore 51 extends between upper end 31 and lower end 33 of tool body 34 .
Sleeve sections 52 are secured to tool body 34 within bore 15 as shown in FIGS. 1A , 1 B, 1 C. Sleeves 52 can be generally centered within bore 51 as shown in FIGS. 1A , 1 B, 1 C using spacers 67 that extend along radial lines from the sections 35 - 39 .
Each valving member 43 , 44 , 45 is movable between open and closed positions. In FIGS. 1A , 1 B, 1 C each of the valving members 43 , 44 , 45 is in a closed position. In that closed position, each valving member 43 , 44 , 45 prevents downward movement of a plug, ball 40 , 42 , or dart 41 as shown. In FIG. 1A , the closed position of valving member 43 prevents downward movement of larger diameter ball 40 . Similarly, in FIG. 1B , a closed position of valving member 44 prevents a downward movement of dart 41 . In FIG. 1B , a closed position of valving member 45 prevents a downward movement of smaller diameter ball 42 . In each instance, the ball, dart or plug rests upon the outer curved surface 68 of valving member 43 , 44 or 45 as shown in the drawings.
Each valving member 43 , 44 , 45 provides a pair of opposed generally flat surfaces 69 , 70 (see FIGS. 3 , 6 , 17 ). FIG. 17 shows in more detail the connection that is formed between each of the valving members 43 , 44 , 45 and the tool body 34 . The tool body 34 provides opposed openings 90 that are receptive the generally cylindrically shaped valve stems 54 , 55 that are provided on the flat sections or flat surfaces 69 , 70 of each valving member 43 , 44 , 45 . For example, in FIGS. 6 and 17 , the flat surface 69 provides valve stem 54 . Openings 90 are receptive of the parts shown in exploded view in FIG. 17 that enable a connection to be formed between the valving member 43 , 44 or 45 and the tool body 34 . For the stem 55 , fastener 91 engages an internally threaded opening of stem 55 . Bushing 92 is positioned within opening 90 and the outer surface of stem 55 registers within the central bore 95 of bushing 92 . Bushing 92 is externally threaded at 93 for engaging a correspondingly internally threaded portion of tool body 34 at opening 90 . O-rings 60 can be used to interface between stem 55 and bushing 92 . A slightly different configuration is provided for attaching stem 54 to tool body 34 . Sleeve 94 occupies a position that surrounds stem 54 . Sleeve 54 fits inside of bore 95 of bushing 92 . The externally threaded portion 93 of bushing 92 engages correspondingly shaped threads of opening 90 . Pins 99 form a connection between the stem 54 at openings 98 and the sleeve 94 . Fastener 96 forms a connection between bushing 92 and an internally threaded opening 97 of stem 54 . As assembled, this configuration can be seen in FIG. 1A for example. The flat surfaces 69 , 70 enable fluid to flow in bore 51 in a position radially outwardly or externally of sleeve or sleeve section 52 by passing between the tool body sections 35 , 36 , 37 , 38 , 39 and sleeve 52 . Thus, bore 51 is divided into two flow channels. These two flow channels 71 , 72 include a central flow channel 71 within sleeves 52 that is generally cylindrically shaped and that aligns generally with the channel 53 of each valving member 43 , 44 , 45 . The second flow channel is an annular outer flow channel 72 that is positioned in between a sleeve 52 and the tool body sections 35 , 36 , 37 , 38 , 39 . The channels 71 , 72 can be concentric. The outer channel 72 is open when the valving members 43 , 44 , 45 are in the closed positions of FIGS. 1A , 1 B and 1 C, wherein central flow channel 71 is closed.
When the valving members 43 , 44 , 45 are rotated to a closed position, fins 73 become transversely positioned with respect to the flow path of fluid flowing in channel 72 thus closing outer flow channel 72 (see FIG. 5 ). This occurs when a valving member 43 , 44 , 45 is opened for releasing a ball 40 or 42 or for releasing dart 41 . FIG. 4 illustrates a closed position ( FIG. 4 ) of the valving member 45 just before releasing smaller diameter ball 42 . Fins 73 are generally aligned with bore 15 and with flow channels 71 , 72 when flow in channel 72 is desired ( FIG. 4 ). In FIG. 4 , valving member 45 is closed and outer flow channel 72 is open.
In FIGS. 2-3 , 5 and 7 - 8 , a tool 74 has been used to rotate valving member 45 to an open position that aligns its channel 53 with central flow channel 71 enabling smaller diameter ball 42 to fall downwardly via central flow channel 71 ( FIG. 8 ). In FIG. 5 , outer flow channel 72 has been closed by fins 73 that have now rotated about 90 degrees from the open position of FIG. 4 to the closed position. Fins 73 close channel 72 in FIG. 5 . It should be understood that tool 74 can also be used to rotate valving member 44 from an open position of FIG. 1B to a closed position such as is shown in FIG. 5 when it is desired that dart 41 should drop. Similarly, tool 74 can be used to rotate upper valving member 43 from the closed position of FIG. 1A to an open position such as is shown in FIG. 5 when it is desired to drop larger diameter ball 40 .
FIGS. 7-16 illustrate further the method and apparatus of the present invention. In FIG. 8 , lower or third valving member 45 has been opened as shown in FIG. 5 releasing smaller diameter ball 42 . In FIG. 8 , smaller diameter ball 42 is shown dropping wherein it is in phantom lines, its path indicated schematically by arrows 75 .
FIG. 10 shows a pair of commercially available, known plugs 76 , 77 . These plugs 76 , 77 include upper plug 76 and lower plug 77 . Each of the plugs 76 , 77 can be provided with a flow passage 79 , 81 respectively that enables fluid to circulate through it before ball 42 forms a seal upon the flow passage 81 . Smaller diameter ball 42 has seated upon the lower plug 77 in FIG. 10 so that it can now be pumped downwardly, pushing cement 80 ahead of it. In FIG. 11 , arrows 78 schematically illustrate the downward movement of lower plug 77 when urged downwardly by a pumped substance such as a pumpable cement or like material 80 . Each of the plugs 76 , 77 can be provided with a flow passage 79 , 81 respectively that enables fluid to circulate through it before ball 42 forms a seal upon the flow passage 81 (see FIG. 11 ). When plug 77 reaches float valve 28 , pressure can be increased to push ball 42 through plug 77 , float valve 28 and casing shoe 27 so that the cement flows (see arrows 100 , FIG. 11 ) into the space 101 between formation 26 and casing 32 .
In FIG. 12 , second valving member 44 is opened releasing dart 41 . Dart 41 can be used to push the cement 80 downwardly in the direction of arrows 82 . A completion fluid or other fluid 83 can be used to pump dart 41 downwardly, pushing cement 80 ahead of it. Once valves 44 and 45 are opened, fluid 83 can flow through openings 84 provided in sleeves 52 below the opened valving member (see FIG. 7 ) as illustrated in FIGS. 7 and 12 . Thus, as each valving member 43 or 44 or 45 is opened, fluid moves through the openings 84 into central flow channel 71 .
When valve 44 is opened, dart 41 can be pumped downwardly to engage upper plug 76 , registering upon it and closing its flow passage 79 , pushing it downwardly as illustrated in FIGS. 14 and 15 . Upper plug 79 and dart 41 are pumped downwardly using fluid 83 as illustrated in FIGS. 14 and 15 . In FIG. 16 , first valving member 43 is opened so that larger diameter ball 40 can move downwardly, pushing any remaining cement 80 downwardly.
The ball 40 can be deformable, so that it can enter the smaller diameter section 86 at the lower end portion of tool body 34 . During this process, cement or like mixture 80 is forced downwardly through float collar 28 and casing shoe 27 into the space that is in between production casing and formation 26 . This operation helps stabilize production casing 32 and prevents erosion of the surrounding formation 26 during drilling operations.
During drilling operations, a drill bit is lowered on a drill string using derrick 12 , wherein the drill bit simply drills through the production casing 32 as it expands the well downwardly in search of oil.
FIGS. 18-26 show an alternate embodiment of the apparatus of the present invention, designated generally by the numeral 110 in FIGS. 22-23 . In FIGS. 18-26 , the flow openings 84 in sleeves 52 of ball/plug dropping head 110 of FIGS. 1-17 have been eliminated. Instead, sliding sleeves 111 are provided that move up or down responsive to movement of a selected valving member 112 , 113 . It should be understood that the same tool body 34 can be used with the embodiment of FIGS. 18-26 , connected in the same manner shown in FIGS. 1-17 to tubular member 22 and string 16 . In FIGS. 18-26 , valving members 112 , 113 replace the valving members 43 , 44 , 45 of FIGS. 1-17 . In FIGS. 18-26 , sleeves 111 replace sleeves 52 . While two valving members 112 , 113 are shown in FIGS. 22 , 23 , it should be understood that three such valving members (and a corresponding sleeve 111 ) could be employed, each valving member 112 , 113 replacing a valving member 43 , 44 , 45 of FIGS. 1-17 .
In FIGS. 18-26 , tool body 34 has upper and lower end portions 31 , 33 . As with the preferred embodiment of FIGS. 1-17 , a flow bore 51 provides a central flow channel 71 and outer flow channel 72 . Each valving member 112 , 113 provides a valve opening 114 . Each valving member 112 , 113 provides a flat surface 115 (see FIG. 20 ). Each valving member 112 , 113 provides a pair of opposed curved surfaces 116 as shown in FIG. 20 and a pair of opposed flat surfaces 117 , each having a stem 119 or 120 .
An internal, generally cylindrically shaped surface 118 surrounds valve opening 114 as shown in FIG. 20 . Each valving member 112 , 113 provides opposed stems 119 , 120 . Each valving member 112 , 113 rotates between opened and closed positions by rotating upon stems 119 , 120 . Each of the stems 119 , 120 is mounted in a stem opening 90 of tool body 34 at positions 61 , 62 and 63 , 64 as shown in FIG. 22 .
In FIG. 19 , valving member 122 , 123 is similar in configuration and in sizing to the valving members 43 , 44 , 45 of the preferred embodiment of FIGS. 1-17 , with the exception of a portion that has been removed which is indicated in phantom lines in FIG. 19 . The milled or cut-away portion of the valving member 112 , 113 is indicated schematically by the arrow 121 . Reference line 122 in FIG. 19 indicates the final shape of valving member 112 , 113 after having been milled or cut. In FIGS. 20 and 21 , a beveled edge at 123 is provided for each valving member 112 , 113 .
When a valving member 112 , 113 is in the closed position of FIG. 22 , flow arrows 124 indicate the flow of fluid through the tool body 34 bore 51 and more particularly in the outer channel 72 as indicated in FIG. 22 .
In FIG. 23 , the lower valving member 113 has been rotated to an open position as indicated schematically by the arrow 134 , having been rotated with tool 74 . In this position, fins 73 now block the flow of fluid in outer channel 72 . Flat surface 115 now faces upwardly. In this position, the cut-away portion of valving member 113 that is indicated schematically by the arrow 121 in FIG. 19 now faces up. Sliding sleeve 111 drops downwardly as indicated schematically by arrows 130 when a valving member 112 or 113 is rotated to an open position (see valving member 113 in FIG. 23 ). In FIG. 22 , a gap 129 was present in between upper valve 112 and sleeve 111 that is below the valve 112 . The sleeve 111 that is in between the valves 112 , 113 is shown in FIG. 22 as being filled with very small diameter balls or “frac-balls” 102 .
When valving member 113 is rotated to the open position of FIG. 23 , the gap is now a larger gap, indicated as 135 . Gap 135 (when compared to smaller gap 129 ) has become enlarged an amount equal to the distance 121 illustrated by arrow 121 in FIG. 19 . The frac-balls 102 now drop through valving member 113 as illustrated by arrows 127 in FIG. 23 . Arrows 125 , 126 in FIG. 23 illustrate the flow of fluid downwardly through gap 135 and in central channel 71 .
A sleeve 111 above a valving member 112 or 113 thus move up and down responsive to a rotation of that valving member 112 or 113 . Spacers 28 can be employed that extend from each sleeve 111 radially to slidably engage tool body 34 . In FIGS. 20 and 21 , each stem 119 , 120 can be provided with one or more annular grooves 131 that are receptive of o-rings 60 or other sealing material. As with the preferred embodiment of FIGS. 1-17 , openings 132 in each stem 119 , 120 are receptive of pins 99 . Likewise, each stem 119 , 120 provides internally threaded openings 133 . Thus, the same connection for attaching a valving member 112 , 113 to tool body 34 can be the one shown in FIGS. 1-17 .
The following is a list of parts and materials suitable for use in the present invention.
PARTS LIST
Part Number
Description
10
oil well drilling structure
11
platform
12
derrick
13
top drive unit
14
flow line
15
ball/plug dropping head
16
string
17
sea bed/mud line
18
body of water
19
water surface
20
platform deck
21
lifting device
22
tubular member
23
well bore
24
surface casing
25
cement/concrete
26
formation
27
casing shoe
28
float valve
29
passageway
30
passageway
31
upper end
32
liner/production casing
33
lower end portion
34
tool body
35
section
36
section
37
section
38
section
39
section
40
larger diameter ball
41
dart
42
smaller diameter ball
43
first valving member
44
second valving member
45
third valving member
46
threaded connection
47
threaded connection
48
threaded connection
49
threaded connection
50
threaded portion
51
flow bore
52
sleeve
53
channel
54
stem
55
stem
56
sleeve
57
sleeve
58
plug
59
plug
60
o-ring
61
opening position
62
opening position
63
opening position
64
opening position
65
opening position
66
opening position
67
spacer
68
outer curved surface
69
flat surface
70
flat surface
71
central flow channel
72
outer flow channel
73
fin
74
tool
75
arrow
76
upper plug
77
lower plug
78
arrows
79
flow passage
80
cement
81
flow passage
82
arrow
83
fluid
84
opening
85
opening
86
smaller diameter section
87
arrow - fluid flow path
88
fastener
89
internally threaded opening
90
opening
91
fastener
92
bushing
93
external threads
94
sleeve
95
passageway/bore
96
fastener
97
internally threaded opening
98
opening
99
pin
100
arrows
101
space
102
frac-ball
110
ball/plug dropping head
111
sleeve
112
valving member
113
valving member
114
valve opening
115
flat surface
116
curved surface
117
flat surface
118
internal surface
119
stem
120
stem
121
arrow
122
reference line
123
beveled edge
124
arrow
125
arrow
126
arrow
127
arrow
128
spacer
129
smaller gap
130
arrow sleeve movement
131
annular groove
132
opening
133
internally threaded opening
134
arrow
135
larger gap
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured valving member with curved and flat portions that alternatively direct fluid flow through a bore or opening in the valving member via an inner channel or around the periphery of the valving member in an outer channel. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a thermally printable paper article with an elastomeric underlayer. The article of the present invention provides improved printing performance by virtue of the underlayer.
[0002] In direct thermal printing, a thermal printhead comes in direct contact with paper to heat the paper and produce an image. When the paper does not contact the printhead completely, the heat conveyed to the paper tends to diffuse, resulting in unfavorably low energy efficiency. Conventionally, thermal papers are produced with high smoothness to achieve better contact between the printer and the paper; nevertheless, the match is imperfect and, consequently, defects are manifested in the image in the form of missing dots. These missing dots, which are voids found in, for example, bars of a barcode or spots found in spaces of the code that are read as irregularities in the reflectance profile, result in poor barcode readability.
[0003] It would therefore be an advantage in the art of thermal printing to find a way to improve print performance by improving contact between the printhead and the paper.
SUMMARY OF THE INVENTION
[0004] The present invention addresses a need in the art by providing, in a first aspect, a coated paper article comprising:
[0000] a) a 40-μm to 500-μm thick paper substrate;
b) a 3-μm to 20-μm thick elastomeric layer having a compressive modulus in the range of from 10 3 Pa to 10 8 Pa disposed over the paper substrate;
c) a 2-μm to 10-μm thick pigmented heat insulating layer comprising insulating particles selected from the group consisting of hollow sphere polymer particles, clay particles, and zeolite particles disposed over the elastomeric layer; and
d) a 1-μm to 10-μm thick thermosensitive recording layer disposed over the pigmented heat insulating layer.
[0005] In a second aspect, the present invention is a coated paper article comprising:
[0000] a) a 40-μm to 500-μm thick paper substrate;
b) a 3-μm to 20-μm thick elastomeric layer of interconnecting polymer particles disposed over the paper substrate, wherein the polymer particles have a core-shell morphology wherein the weight-to-weight ratio of the core to the shell is in the range of from 80:20 to 98:2; wherein the core comprises, based on the weight of the core, from 90 to 99.9 weight percent structural units of a monomer selected from the group consisting of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2-propylheptyl acrylate, and from 0.1 to 10 weight percent structural units of a multiethylenically unsaturated monomer;
c) a 2-μm to 10-μm thick pigmented heat insulating layer comprising insulating particles selected from the group consisting of hollow sphere polymer particles, clay particles, and zeolite particles disposed over the elastomeric layer; and
d) a 1-μm to 10-μm thick thermosensitive recording layer disposed over the pigmented heat insulating layer.
[0006] The article of the present invention provides a way to improve print performance by mitigating the adverse effects of pressure applied to the paper.
DETAILED DESCRIPTION OF THE INVENTION
[0007] In a first aspect, the present invention is a coated paper article comprising:
[0000] a) a 40-μm to 500-μm thick paper substrate;
b) a 3-μm to 20-μm thick elastomeric layer having a compressive modulus in the range of from 10 3 Pa to 10 8 Pa disposed over the paper substrate;
c) a 2-μm to 10-μm thick pigmented heat insulating layer comprising insulating particles selected from the group consisting of hollow sphere polymer particles, clay particles, and zeolite particles disposed over the elastomeric layer; and
d) a 1-μm to 10-μm thick thermosensitive recording layer disposed over the pigmented heat insulating material layer.
[0008] The article of the present invention is advantageously prepared by applying an elastic layer, then an insulating layer, and then a thermosensitive recording layer to the paper by sequential drawdowns of aqueous coating formulations. In a preferred method of applying the elastic layer, an aqueous dispersion of polymer particles having a compressive modulus in the range of from 10 3 Pa, preferably from 10 4 Pa, more preferably from 10 6 Pa to 10 8 Pa is applied to the paper substrate using a wire-wound rod at controlled speed on a drawdown machine. The coated paper is then advantageously dried at advance temperatures before the next layer is applied.
[0009] The polymer particles are preferably characterized by a core-shell morphology, wherein the core comprises from 80, more preferably from 85, and most preferably from 90 weight percent, to preferably 98, and more preferably to 96 weight percent of the polymer particles, and the shell comprises preferably from 2, more preferably from 5 weight percent, to preferably 20, more preferably to 15, and most preferably to 10 weight percent of the polymer particles.
[0010] The core preferably comprises, based on the weight of the core, from 90, more preferably from 95, and most preferably from 98 weight percent, to preferably 99.9, more preferably to 99.8, and most preferably to 99.5 weight percent structural units of a monomer selected from the group consisting of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2-propylheptyl methacrylate. The core preferably further comprises, based on the weight of the core, from 0.1, more preferably from 0.2, and most preferably from 0.5 weight percent, to preferably 10, more preferably to 5, and most preferably to 2 weight percent structural units of a multiethylenically unsaturated monomer. Preferred multiethylenically unsaturated monomers are diethylenically unsaturated monomers such as allyl methacrylate, divinyl benzene, butylene glycol diacrylate, ethylene glycol diacrylate, butylene glycol dimethacrylate, and ethylene glycol dimethacrylate.
[0011] The shell preferably comprises structural units of at least one monomer selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, and t-butyl methacrylate. Preferably, at least 90%, more preferably at least 95%, and most preferably at least 98% of the core comprises structural units of butyl acrylate and allyl methacrylate; preferably at least 90%, more preferably at least 95%, and most preferably at least 98% of the shell comprises structural units of methyl methacrylate.
[0012] The preferred thickness of the elastomeric layer is from 5 μm to 15 μm (˜5 g/m 2 to 15 g/m 2 ).
[0013] An insulating layer is formed by applying an aqueous dispersion or hollow sphere polymer particles or an aqueous suspension of clay or zeolite particles to the coated paper and drying applied coating. Commercially available aqueous dispersions of hollow sphere polymer particles include ROPAQUE™ TH-2000 Hollow Sphere Polymer, ROPAQUE™ AF-1055 Hollow Sphere Polymer, and ROPAQUE™ Ultra E Opaque Polymer. (A Trademark of The Dow Chemical Company or its Affiliates.) The particle size of the hollow sphere polymers is typically in the range of from 275 nm, more preferably from 350 nm, to preferably 2 μm, more preferably to 1.8 μm, and most preferably to 1.6 μm. Preferably, thickness of the insulating layer is in the range of from 4 μm to 8 μm (corresponding to ˜1.4 g/m 2 to 10 g/m 2 , depending on the density of the insulating material.)
[0014] A solution of a thermosensitive recording material is then advantageously applied to the paper coated with the elastomeric and insulating layers and dried. The thermosensitive recording material typically comprises a leuco dye and a color developer (see U.S. Pat. No. 4,929,590) and may also comprise a variety of other additives including binders, fillers, crosslinking agents, surface active agents, and thermofusible materials.
[0015] As the following examples demonstrate, the article of the present invention shows an improvement in optical density, which is an indicator of print quality, over coated paper that does not include an elastomeric layer.
[0016] For Example 1, the polymer particles that form the elastomeric layer are characterized as shown in Table 1. BA refers to butyl acrylate, ALMA refers to allyl methacrylate, and MMA refers to methyl methacrylate. Compressive Modulus was calculated as described in the section titled Calculation of Compressive Modulus.
[0000]
TABLE 1
Characterization of Polymer Particles
forming the Elastomeric Layer
Core:Shell wt/wt ratio
94:4
Core (wt %)
Copolymer of BA(99.3)/ALMA(0.7)
Shell (wt %)
Poly(MMA)
Compressive Modulus
2.1 MPa
Example 1—Preparation of a Coated Paper Article with an Elastomeric Underlayer
[0017] An aqueous dispersion of the core-shell elastomeric polymer particles (119.9 g, 51.3% solids, particle size 170 nm) was combined with RHOPLEX™ P308 Binder (a Trademark of The Dow Chemical Company or Its Affiliates, 10.1 g, 49.8% solids), and water (31.6 g) with stirring. A coating was applied to the paper substrate using a wire-wound rod at a controlled speed on a drawdown machine; the coated paper was then transferred to a convection oven set at 80° C. to dry for 1 min. The density of the elastomeric layer was found to be 3.7 g/m 2 as determined by cutting a known area of coated material and weighing the sample.
[0018] A solution of ROPAQUE AF-1055 Hollow Sphere Polymer (71.7 g, 26.7% solids), RHOPLEX P308 Binder (8.8 g, 49.8% solids), polyvinyl alcohol (obtained from Kremer Pigmente, 3.9 g, 14.5% solids), and water (117.5 g) was prepared; the pH of the mixture was adjusted to 7.5 and the viscosity adjusted to 400 cPs with RHOPLEX RM232D Rheology Modifier. A portion of this mixture was then applied and dried as described above. The density of the applied coating was 3.5 g/m 2 .
[0019] The thermosensitive recording formulation was prepared by mixing together water (5.7 g) and a dispersant (0.03 g) with stirring. Calcium carbonate powder (4.4 g, Tunex-E from Shirashi Kogyo Kaisha, Ltd.) was then added slowly and stirring was continued for 5 min before silica powder (3.7 g, Mizucasil P-603 from Mizusawa Kagaku K.K.) was added slowly to the mixture. Stirring was continued for an additional 5 min during which time an aqueous dispersion of 4-hydroxy-4′-isopropoxydiphenylsulfone (8.8 g, 50% solids) was slowly added, followed by the addition of an aqueous dispersion of 2-benzyl-oxy-napthalene (7.3 g, 40% solids), followed by addition of an aqueous dispersion of zinc stearate (3.1 g), then an aqueous dispersion of 2-anilino-6-(dibutylamino)-3-methylfluoran (5.2 g, 35% solids). Then, defoamer (0.007 g) was added and the mixture was allowed to stir for an additional 5 min. Finally, a solution of fully hydrolyzed polyvinyl alcohol (14.7 g) was slowly added and stirring continued for an additional 5 min. The density of the applied coating was 3.5 g/mm 2 .
Comparative Example 1—Preparation of a Coated Paper Article without an Elastomeric Underlayer
[0020] The article of the comparative example was prepared essentially as described in Example 1 except for the absence of elastomeric layer step. The optical densities of the two samples were measured at 8 mJ/mm 2 in accordance with ASTM F1405 using an Atlantek M200 thermal printer and an X-Rite optical densitometer. The coated substrate of Example 1 was found to have an optical density of 1.19 AU while the coated substrate of Comparative Example 1 was found to have an optical density of 0.86 AU. The higher optical density observed for the example of the invention correlates with significantly higher print quality.
Calculation of Compressive Modulus
[0021] Thermal Mechanical Analysis was carried out using a TA Q400 Thermomechanical Analyzer equipped with a compression sample fixture. Samples of dried coating slab were prepared by pouring a 1-mm thick aqueous coating formulation onto a smooth Teflon petri dish and drying the sample in vacuo at 50° C. The dried specimen was removed from the Teflon surface and released as a free standing pellet. On the TA Q400 instrument with probe tip fixture, the force was ramped from 0.05 N was ramped to 0.5 N, while at the same time the dimensions of the coating pellet sample were measured. The dimension and force were then calculated to yield stress and strain according to the formula:
[0000]
σ
=
F
A
,
[0000] where σ is stress, F is the force applied from the probe, and A is the area of the probe in contact with the sample surface.
[0000]
ɛ
=
l
-
l
0
l
0
,
[0000] where ε is strain, calculated from measured real time thickness of specimen l, and original thickness of specimen l 0 before force was applied. When strain versus stress is plotted, the slope of the strain stress curve gives the compressive modulus of the test specimen.
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The present invention relates to a thermally printable paper article with an elastomeric underlayer, which imparts improved printing performance.
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BACKGROUND OF THE INVENTION
Modern day data processing systems are often made up of several processor units, several memory storage units, several control units and a variety of input output devices. Often each of these units is housed in one or more cabinets arranged within a specially designed computer room. The use of cabinets is particularly useful where the data processing system is modularized, i.e., its capacity can be increased or decreased by adding or removing cabinets. Such cabinets have found use more and more with the advent of circuit boards, each of which has mounted or otherwise formed thereon complete logic arrays. Several of these circuit boards may be removably disposed in each cabinet and are of such a nature that in the maintenance or trouble shooting of the data processing system they may be removed and replaced with little effort.
The cabinets which house such circuitry generally provide easy access for such replacement. Panels or doors secured to the cabinets by screws or the like which may be removed provide one manner in which such access may be provided.
Another way is simply to provide each cabinet with hinged doors which may be opened to allow maintenance or testing of the various components. Often times it is advantageous to remove the door completely to permit major repair or replacement of one or more defective circuit board or in the actual factory assembly of circuitry and electrical interconnection during the manufacturing process.
In the field where on site maintenance occurs, the various cabinets are generally arrayed in side by side or adjacent relationship. In such an environment, the door hinges must be such as to permit the door to be easily removed without serious interference with adjacent cabinets.
OBJECTS
It is an object of the present invention to provide a hinge arrangement to permit easy removal of a cabinet door.
It is another object of the present invention to provide a hinge arrangement which permits easy removal of a cabinet door but which prevents accidental removal of the door.
A further object of the present invention is to provide a hinge arrangement which facilitates rapid removal of a cabinet door, prevents accidental removal thereof and one in which the hinges are so designed as not to interfere with or damage adjacent cabinets.
DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a side view of the cabinet and door hinge arrangement of the present invention;
FIG. 2 shows a top view of the hinge for the top of the cabinet;
FIG. 3 shows a top view of the hinge for the top of the door;
FIG. 4 shows a top view of the hinge for the bottom of the cabinet;
FIG. 5 shows a top view of the hinge for the bottom of the door and taken through line A--A of FIG. 1 with the hinge for the bottom of the cabinet removed;
FIGS. 6a and 6b show a side and top view of the pin used for the hinge at the bottom of the door and cabinet;
FIG. 7 shows the relationship of the hinges at the top of the cabinet and door when the door is in the ninety degree open position and,
FIG. 8 shows the relationship of the hinges at the bottom of the cabinet and door when the door is in the ninety degree open position.
DESCRIPTION OF THE INVENTION
Referring now more particularly to FIG. 1 there is shown in partial outline, a cabinet 10 for housing various components of an electronic data processing system or other types of components, electronic or otherwise.
Secured to the upper left hand portion of the cabinet 10 is an L-shaped hinge 11. One length 11a of the hinge 11 is fixed to the cabinet by any convenient means, e.g., countersunk screws (not shown). The other length 11b of the hinge extends perpendicularly from the cabinet 10.
Length 11b has a hole 12 as best seen in FIG. 2 in which a pin 13 is firmly held, as for example, by a press fit. The pin 13 extends downwardly below the bottom surface of length 11b for cooperation with the upper door hinge as is described hereinbelow.
Secured to the upper left hand portion of a door 14 is an L-shaped hinge 15. The hinge 15 has a length 15b secured as by countersunk screws (not shown) to the upper edge of the door 14 and a length 15a which extends around the back of the door 14. The length 15a which is substantially less in dimension than length 11a abuts the length 11a when the door 14 is in the closed position as shown.
A portion of length 15b extends beyond the door and as best seen in FIG. 3 has a hole 16 formed therein. The hole 16 has a diameter slightly greater than the diameter of the pin 13.
The pin 13 is received in hole 16 and supports the door 14 against lateral movement while at the same time permitting rotational movement when the door is opened and shut.
Secured to the lower left hand side of the cabinet 10 is another L-shaped hinge 17 substantially of the same configuration as hinge 11.
Hinge 17 has a length 17a secured as by countersunk screws (not shown) to the cabinet 10 and a length 17b which extends perpendicularly away from the cabinet 10. The length 17b has a hole 18 as best seen in FIG. 4 into which a pin 19 is secured as by a press fit. The pin 19 extends upwardly beyond the upper surface of the length 17b.
As seen in FIGS. 6a and 6b the upper half of the portion of the pin 19 which extends beyond the upper surface of the length 17a has cut portions which form opposite flat surfaces 19a the planes of which are perpendicular to the front of cabinet 10.
Secured to the lower edge of the door 14 is an L-shaped hinge 20. The hinge 20 is similar in configuration to the hinge 15. It has a length 20a disposed against the back of the door 14 and abutting length 17a of the hinge 17 with the length 20a being substantially shorter than the length 17a. The hinge 20 has a length 20b secured to the door as by countersunk screws (not shown) extending perpendicularly away from the door 14.
The hinge 20 has a hole 21 in length 20b for receiving the pin 19. As seen in FIG. 5, extending from the hole 21 is a slot 22 the center line of which is always parallel to the front surface of the door 14 regardless of which position the door 14 happens to be in.
The slot 22 has a width less than the diameter of the hole 21 but greater than the distance between surfaces 19a of the pin 19.
As seen in FIG. 1 the door 14 effectively rests on the hinge 17. The portion of the pin 19 having the surfaces 19a protrudes beyond the hole 21. In this position, the pin 19 prevents lateral movement of the door while permitting its rotational movement as when the door 14 is open or shut.
From examination of FIGS. 2, 3, 4 and 5, it is apparent that the upper and lower hinges are in virtual coincidence when the door is in the closed position. It should be noted that the hinges are so configured and positioned that they do not interfere with adjacent cabinets.
Likewise as seen in FIGS. 6 and 7 where the door 14 is shown in its 90° open position, neither of the hinges extends beyond a line extending from the side of the cabinet 10 and thus no inference exists with adjacent cabinets.
Also, as seen in FIG. 1 there is a gap 23 between hinges 11 and 12. Since the pin 13 loosely fits into hole 16 of the hinge length 15b, the door may be raised upwardly the distance of the gap 23.
As seen in FIGs. 3 and 5, hinges 15 and 20 are cut off to form surfaces 15c and 20c respectively on lengths 15a and 20a to facilitate opening and shutting the door 14. When the door 14 is in the 90° open position, the slot 22 is aligned with the width of the pin 19 between the surfaces 19a. In this position, the door 14 may be removed by raising the door 14 until the slot 22 is opposite the width defined by the surfaces 19a. At this point the bottom of the door is easily moved away from the cabinet since the pin 19 no longer restrains lateral movement in this direction.
When the door 14 has been removed at the bottom of the cabinet 10, the door is lowered somewhat until hole 16 is disengaged from the pin 13 and the door is then completely removed from the cabinet. As can be understood, such removal is done without the slightest interference with cabinets that may be adjacent.
Similarly, the door 14 may be placed back on the cabinet by holding the door 14 in the ninety degree open position and inserting pin 13 in hole 16. While holding the door up the pin 19 may be inserted in hole 21 of hinge length 10b by sliding the slot 22 past surfaces 19a of pin 19. When this is accomplished the door is lowered so that it rests on the length 17b of hinge 17. In this position the surfaces 19a are above slot 22 and the door is restrained from lateral movement since the diameter of the pin 19 is greater than the width of the slot 22.
Other modifications of the present invention are possible in light of the above description and the illustrations of the present invention set forth should not be construed as placing limitations on the present invention other than those contained in the claims which follow.
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A hinge arrangement to permit quick removal of a cabinet door without interference with adjacent cabinets. The hinge arrangement is so configured as to permit the door to be removed by manually lifting the door out when it is in the ninety degree open position.
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BACKGROUND OF THE INVENTION
The present invention generally relates to an input device, such as a mouse, and more particularly relates to a mouse that includes an exchangeable palm rest for adjusting the size of the mouse.
Input devices for computers and the like typically include mice, keyboards, joysticks, touch pads and the like for computer control. These input devices are typically used to control computer applications that typically include graphical objects that may be manipulated by the input device. Typical input devices often include one or more buttons and a roller for computer control. Mice often do not comfortably fit a user's hand size as the mice do not have adjustable body sizes. For example, may designers make mice to fit men's hands but fail to make mice that fit women and children's hands.
Examples of mice having adjustable body elements include: Logitech Europe S.A. U.S. Pat. No. 6,704,003, Felton U.S. Pat. No. 6,690,359, Sharp Laboratories U.S. Pat. No. 6,567,073, Shearn U.S. Pat. No. 6,229,527, IBM U.S. Pat. No. 6,195,085, Wacom U.S. Pat. No. 6,154,196, France Telecom U.S. Pat. No. 6,118,431, and Harskamp U.S. Pat. No. 6,016,138.
The mouse industry continues to strive to develop new mouse devices that are adjustable to comfortably fit a user's hand.
BRIEF SUMMARY OF THE INVENTION
The present invention generally provides an input device, such as a mouse, and more particularly provides a mouse that includes a dead front display.
According to one embodiment, the mouse includes a mouse body having a first side and a second side; and a palm rest coupled to the sides of the mouse body. The palm rest has a first size and the palm rest is configured to be removed from the mouse body to fit another palm rest to the mouse body having. The size of the other palm rest has a second size that is different from the first size. The palm rest includes a first arm, a second arm, and a body portion that couples the first arm and the second arm. The first arm and the second arm are respectively coupled to the first side and the second side of the mouse body. According to a specific embodiment, the mouse body has a different width, a different length, and/or a different height from the other mouse body. The palm rest is configured to be pivoted to raise and lower the body portion of the palm rest. The mouse body includes a back side between the first and second sides, and the body portion of the palm rest is coupled to back side of the mouse body. The body portion of the palm rest is coupled to the back side by a retractable attachment device. The mouse body includes a front side that is oppositely disposed with respect to the back side and includes a least one control button and a scroll wheel that are disposed substantially on the front side of the mouse body. The first and second arms respectively include first and second pins, the first and second sides respectively include first and second pin cavities, and the first and second pin cavities are removably coupled to the first and second pins to removably couple the palm rest to the mouse body. The first and second pins are configured to slide from the first and second cavities to decouple the palm rest from the mouse body.
The palm rest is coupled to the mouse body such that a gap is formed between the palm rest and the mouse body and the gap is configured as a vent. The mouse body may include a fan device configured to circulate air in the gap. The mouse body may also include a weight disk removably coupled to a bottom surface of the mouse body, wherein the weight disk is configured to include a set of removable weights to adjust the balance and/or weight of the mouse.
According to another embodiment of the invention, the mouse includes a mouse body having a first side and a second side, wherein a first plurality of indents are formed in the first side and a second plurality of indents are formed in the second side; and a palm rest coupled to the mouse body. The palm rest has a first size and is configured to be removed from the mouse body to fit another palm rest to the mouse body having a second size that is different from the first size. The palm rest includes a first arm, a second arm, and a body portion that couples the first arm and the second arm. The first arm includes a first pin device formed thereon, and the second arm includes a second pin device formed thereon. The first arm and the second arm are respectively coupled to the first side and second side of the mouse body. The first pin and the second pin are respectively configured to be positioned in the first plurality of indents and the second plurality of indent to tilt the body portion of the palm rest up or down. The mouse body has a different width, a different length, and/or a different height from the width, the length, and/or the height of the other mouse body.
A better understanding of the nature and advantages of the present invention may be gained with reference to the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are simplified side and top views of a mouse having a mouse body and an exchangeable palm rest according to one embodiment of the present invention;
FIGS. 2A-2C are simplified top views of exemplary palm rests having various sizes;
FIGS. 3A-3C are simplified side views of the palm rests shown respectively in FIG. 2A-2C ;
FIG. 4 is an enlarged view of a pin cavity formed in the mouse body according to one embodiment of the present invention;
FIGS. 5A and 5B are simplified top and side views of a mouse according to another embodiment of the present invention;
FIGS. 6A and 6B are bottom and side views of a mouse having a weight disk according to another embodiment of the present invention; and
FIGS. 7A and 7B are side and top views of a mouse according to another embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIGS. 1A and 1B are simplified side and top views of a mouse 100 having a mouse body 102 and an exchangeable palm rest 105 according to one embodiment of the present invention. Palm rest 105 generally has a u-shape with two arms 110 a and 110 b that extend from a body portion 110 c of the palm rests. Arms 110 a and 110 b are configured to generally extend along the sides of the mouse body, which may have a generally curved shape. Arms 110 a and 110 b form a portion of the sides of mouse 100 . Body portion 110 c generally extends along a back portion of the mouse body and forms a back portion of mouse 100 . Various size palm rests 105 may be coupled to the mouse body to adjust the width, height, and/or length of the mouse. It should be understood the while element 105 is referred to as a palm rest, the palm rest may have a relatively short body portion 110 c such that the palm rest does not extend under a palm portion of a user's hand, but may only extend under the user's fingers. It should also be understood that the palm rest may be substantially long such that the palm rest may also extend beyond the user's palm.
According to one embodiment of the present invention, mouse body 102 includes first and second control buttons 120 a and 120 b and a roller wheel 125 disposed on a front portion of the mouse body. The control buttons may be configured to perform traditional control button functions on a computer controlled by the mouse, such as making a selection on the computer's monitor and/or launching a drop down menu. A selection may include a selection of a portion of text from a document or the like. Document as referred to herein may include a text document, a table, a graphic image, computer code, a web page, or the like. The scroll button may be configured to scroll the document on the monitor, enlarge or reduce the document or the like. Such functions are well known to those of skill in the art and will not be described in further detail herein.
FIGS. 2A-2C are simplified top views of exemplary palm rests 105 a - 105 c , respectively. Palm rests 105 a - 105 c have various sizes. For example, palm rest 105 a has a relatively larger width “w” than palm rests 105 b and 105 c , and palm rest 105 b has a relatively larger width than palm rest 105 c . Palm rest 105 a also has a relatively longer length “1” than palm rests 105 b and 105 c , and palm rest 105 b has a relatively longer length than palm rest 105 c.
FIGS. 3A-3C are simplified side views of palm rests 105 a - 105 c , respectively. Palm rests 105 a - 105 b have various heights “h”. For example, palm rest 105 a has a relatively larger height than palm rests 105 b and 105 c , and palm rests 105 b has a relatively larger height than palm rest 105 c . It should be understood that the height, widths, and lengths of palm rests 105 a - 105 c are exemplary and that palm rests according to embodiments of the present invention may have a variety of heights, widths, and lengths.
Referring again to FIGS. 2A-2C , each palm rests includes a clip 135 on a front portion of the palm rest's body portion. The clip might include a pin, a spring or the like that is configured to couple to an indented portion 140 of the mouse body. Each palm rest may include a retraction device 145 or the like that is configured to retract clip 135 from indent 145 .
According to one embodiment, mouse 100 includes first and second pin cavities 150 a and 150 b that are disposed on opposite side of mouse body 102 . Each palm rest includes first and second pins 155 a and 155 b respectively disposed on inside portions of arms 110 a and 110 b . Pin cavities 150 a and 150 b are configured to respectively receive pins 155 a and 155 b to removably attach the palm rest to the mouse body.
FIG. 4 is an enlarged view of pin cavity 150 a according to one embodiment of the present invention. The pin cavity includes a first slotted portion 160 configured to receive pin 155 a to attach the palm rest to the mouse body. The pin cavity includes a second slotted portion 165 in which the pin 155 a is configured to slide “back” to couple the palm rest to the mouse body as the palm rest is rotated to fit clip 135 into indent 140 . Pin cavity 150 b is configured similarly to pin cavity 150 a on the opposite side of the mouse body and is configured to receive pin 155 b.
According to one embodiment of the present invention, the palm rest is configured such that a vent region 167 is formed between the palm rest and the mouse body. The vent may extend from the bottom of the mouse to the top of the mouse. According to one embodiment, the mouse body includes a fan 170 (see FIG. 4 ) that is configured to blow air from a vent 175 , through gap 167 , and up to a user's hand. The fan may be configured to dry perspiration that forms on the user hand as the user uses the mouse.
FIGS. 5A and 5B are simplified top and side views of a mouse 500 according to another embodiment of the present invention. Mouse 500 is similar to mouse 100 in that mouse 500 includes a mouse body 102 ′ and a palm rest 105 ′, which are similar to mouse body 102 and palm rest 105 described above. Mouse 500 differs from mouse 100 in that the palm rest 105 ′ is configured to be tilted up or down (indicated by arrow 502 ) to raise or lower the body portion 110 c of the palm rest. Specifically, palm rest 105 ′ includes first and second button devices 505 a and 505 b disposed respectively on the left and right arms 110 a and 110 b of the palm rest. The button devices are configured to be positioned in various indents 510 formed on the sides of mouse body 102 ′ to hold the palm rest in various tilted positions. The back of mouse body 102 ′ might also include a number of indents, such as indent 140 , that are configured to receive clip 135 to hold the palm rest in the various tilted positions.
FIGS. 6A and 6B are bottom and side views of a mouse 600 according to one embodiment of the present invention. Mouse 600 includes a weight disk 605 that may be removably attached to the bottom of the mouse. The weight disk includes a set of weight cavities 610 formed therein. The weight cavities are configured to receive a set of weights 615 . As shown in FIG. 6B , the four of the weight cavities are filled with weights 615 , and four of the weight cavities are not filled with weights. The user of mouse 600 may fill the weight cavities with weights to adjust the weight and the weight balance of the mouse. While the weight cavities and weights are shown as generally round, the weight cavities and weights may have a variety of shapes, such as arced or the like. According to one embodiment of the present invention, mouse body 102 includes a weight disk 605 that may be variously filled with weights 615 .
FIGS. 7A and 7B are side and top views of a mouse 700 and of the mouse's associated body portion 705 . Mouse 700 differs from various mice embodiments described above in that mouse 700 includes a palm rest 710 that includes a palm rest portion 110 c that extends over the top of the body and includes arms 710 a and 710 b that extend farther toward the front of the mouse. The arms may include first and second pins 755 a and 755 b respectively disposed on inside portions of arms 710 a and 710 b , and that are configured to fit into pin cavities 750 a and 750 b that are at the front of the mouse body. Similar to mice embodiments described above, mouse 700 include a clip (not shown) that is configured to couple to an indented portion of the mouse body. Similar to mouse embodiments described above, palm rest 710 may have a variety of widths and lengths.
According to one embodiment, one or more palm rests include a dead front display for displaying information to a user. A dead front display is configured to display lighted information through the palm rest, but the information is configured not to be visible if the information is not lighted. For a detailed explanation of dead front displays see U.S. patent Ser. No. 11/356,386, titled Dead Front Mouse, filed Feb. 15, 2006, of David Shaft et al., which is incorporated by reference herein in its entirety.
It is to be understood that the exemplary embodiments described above are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. Therefore, the above description should not be understood as limiting the scope of the invention as defined by the claims.
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A mouse having an adjustable body size includes a mouse body having a first side and a second side; and a palm rest coupled to the mouse body, wherein the palm rest has a first size and the palm rest is configured to be removed from the mouse body to fit another palm rest to the mouse body having a second size that is different from the first size. The palm rest includes a first arm, a second arm, and a body portion that couples the first arm and the second arm. The first arm and the second arm are respectively coupled to the first side and second side of the mouse body.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of U.S. patent application Ser. No. 10/015,588, filed Dec. 17, 2001, which claims priority of U.S. provisional application Ser. No. 60/255,742, filed Dec. 15, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a flow shut off or throttling valve in the nozzle housing of a sprinkler for limiting or preventing flow of water to the nozzle.
[0004] 2. Background of the Invention
[0005] In order to achieve suitably irrigate an irregularly shaped area of land surface or near the borders of a land parcel, it may be desirable to change the distribution profile or configuration in a sprinkler to adjust the coverage range, distribution angle, etc. As a result, several different types of sprinklers have been offered to address this need.
[0006] For example, U.S. Pat. Nos. 3,323,725 to Hruby; 3,383,047 to Hauser; and 4,729,511 to Citron each discloses a sprinkler having various structures for restricting a flow of water through the flow path through the sprinkler. However, restriction of the flow also results in a loss in pressure of the flow exiting from the nozzle. Such limited adjustment capabilities, moreover, are frequently inadequate to provide adequate or even coverage to edges, corners, or more unusual boundaries of a parcel of land to be irrigated.
[0007] U.S. Pat. No. 5,234,169 to McKenzie, on the other hand, discloses a sprinkler which provides a removable nozzle and a camming mechanism for expelling the nozzle from the flow passage in a nozzle housing. It is thus possible to achieve a greater range of distribution profiles with the ability to change the nozzle altogether, relative to the sprinkler systems in the prior art referenced above. With this sprinkler, however, it is necessary to turn off a flow of water to the sprinkler in order to avoid getting wet during the nozzle exchange process.
[0008] Similarly, U.S. Pat. No. 6,085,995 to Kah, Jr. et al. discloses a sprinkler in which a plurality of different nozzles are provided in the nozzle housing, with each nozzle effecting a different distribution profile from the others. A nozzle selection change is easily performed by operating a selection mechanism provided on the nozzle housing. With this sprinkler, however, the plurality of nozzles are provided on a common unit, and a user may not need all of the different types of nozzles provided in the set.
[0009] In U.S. Pat. No. 5,762,270 to Kearby, et al, the disclosed sprinkler unit includes a valve provided in the flow path through the sprinkler housing for stopping the flow through the nozzle for facilitating a nozzle change. The valve, however, is physically disposed within the flow path, regardless of whether the valve is in an opened position or a closed position. Such placement of the valve requires the flow stream to flow around the valve enroute to the nozzle when the valve is open, thus resulting in increased turbulence in the flow stream and pressure loss of the flow exiting from the nozzle.
[0010] It is thus desirable to provide a sprinkler having a removable nozzle and a mechanism for stopping the flow through the nozzle at the sprinkler location, wherein the presence of the mechanism does not introduce a pressure loss to the flow exiting the sprinkler.
SUMMARY OF THE INVENTION
[0011] In a primary aspect of the present invention, a flow control and shut off valve which has a simple configuration is provided in a sprinkler, and can be actuated from the top or side of the nozzle housing to shut off or throttle the flow to one or more sprinkler nozzles. The valve throttles or shuts off a stream of water flowing through the flow path in the nozzle housing at a location upstream of the nozzle, so that the nozzle can be removed and exchanged without having to turn off the water supply to the sprinkler.
[0012] The valve can be formed as a simple and thin component which can be made of a molded plastic. The valve is disposed in the nozzle housing and can be moved in and out of a flow path through the nozzle housing using a valve controller or actuating element, which is engaged with a set of gear teeth molded onto the valve. A tight seal around the valve is achieved by the mating fit between the smooth plastic surfaces of the valve and the valve seat or by the insertion of “O” rings in the valve seat areas. The valve may be a flat or curved component and may operate in a slot or in a cavity molded into the nozzle housing. In each case, an opening in the valve is aligned with the flow path through the nozzle housing so that all the surfaces and edges of the valve are completely out of the flow path when the valve is in a fully opened position.
[0013] The flow control valve of the present invention may provide the ability to throttle or shut off the flow only to a primary nozzle while allowing the flow to continue at full pressure to at least one shorter range secondary nozzle, to thereby maintain good atomization for uniform precipitation close to the sprinkler.
[0014] In another aspect of the present invention, a nozzle retention member may be mechanically linked to the shut off valve so that when the flow shut off valve is moved to a closed position, the nozzle retention is automatically disengaged so that the nozzle may be removed and exchanged while the sprinkler remains pressurized.
[0015] The valve may be actuated by a manual shut off valve actuation ring rotatably mounted around the outside of the nozzle housing. Additionally, selectable stream break-up or deflection lugs which can be moved into the nozzle stream for range control may be mounted on the manual shut off valve actuating ring around the outside of the nozzle housing. Such an arrangement eliminates the need to include a separate stream breakup screw in the nozzle housing, as commonly used in many prior art sprinklers to secure a nozzle in the nozzle housing.
[0016] In one embodiment of the invention, the valve is preferably provided in the nozzle housing of a rotary driven sprinkler and is formed as a sleeve valve having an axis of rotation which is displaced from the rotational center line of the sprinkler to enable straightening of the flow passing between the valve and upstream of the nozzle in a lateral side passage portion of the flow path through the nozzle housing. Generally, the lateral side passage portion extends at an angle from a vertical main portion of the flow path to lead the flow path out of the nozzle housing via the nozzle.
[0017] In another embodiment of the invention, the valve is formed as a cone-shaped element and is disposed in the nozzle housing to intersect the flow passage from the side to shut off the flow through the nozzle passage.
[0018] All of the configurations of the valve allow a stream to flow fully unobstructed through the flow path with no valve pressure loss when the valve is in a fully opened position.
[0019] All of the nozzle housing valve configurations are preferably made to be operated from the top of the nozzle housing or the side of the nozzle housings and to include an indicator on the nozzle housing to indicate the opened or closed state of the valve.
[0020] Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a cross-sectional view of a rotary driven nozzle housing on top of a stationary sprinkler body showing a horizontally placed flow throttling and shut off valve in the nozzle housing.
[0022] FIG. 2 is a cross-sectional view from the top through the plane II-II indicated in FIG. 1 through the nozzle housing showing a vertical portion of the flow path with a throttle valve in a fully opened position to the left in the figure and the valve gate aligned with the flow path.
[0023] FIG. 3 is a cross-sectional view from the top through the plane II-II indicated in FIG. 1 through the nozzle housing showing a vertical portion of the flow path with a throttle valve in a fully closed position to the right.
[0024] FIG. 4 is a cross-sectional view of an entire rotary driven sprinkler including nozzle housing and body showing the placement of an arc setting shaft, flow valve control shaft and components of a gear and water turbine drive.
[0025] FIG. 4A is a partial sectional view from the top of the sprinkler showing the arc set, idler reversing gear and indicator member gear.
[0026] FIG. 5 is a cross-sectional view of a rotary driven nozzle housing having a rotatable sleeve valve positioned with its center line offset from the center line of rotation of the sprinkler and a valve actuation shaft accessible at the top of the sprinkler housing.
[0027] FIG. 6 is a cross-sectional view of a rotary driven nozzle housing including a cone-shaped sleeve valve intersecting the flow passage through the nozzle housing.
[0028] FIG. 7 is a cross-sectional view of a rotary driven nozzle housing with a rotatable sleeve valve connected through an idler gear to a ring gear around the outside circumference of the upper nozzle housing, wherein the ring gear has a serrated outside circumference to facilitate manual operation thereof.
[0029] FIG. 8 is an elevational view of the nozzle housing of FIG. 7 and showing the ring gear as having structure configured to retain or release the changeable nozzle in the nozzle housing. Also shown are selectable stream break-up lugs that can be moved into the stream by further rotation of the ring beyond a position at which the flow valve is opened. A nozzle alignment and removal lug is shown on the bottom of the nozzle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Referring to FIGS. 1-3 of the drawings, a first preferred embodiment of the present invention is shown in which an upper portion of a rotary driven sprinkler 1 includes a cylindrical nozzle housing assembly 2 mounted for rotation about axis X-X on top of a sprinkler stationary body or riser assembly 4 . The riser assembly 4 has an opening 3 at its upper end in which an output drive shaft 5 is received. Output drive shaft 5 extends above the riser assembly 4 and is connected to the nozzle housing assembly 2 for rotationally driving the nozzle housing assembly.
[0031] A flow path through the sprinkler is established via a center flow passage 31 and an outlet passage 33 . Center flow passage 31 is defined by drive shaft 5 and an interior cylindrical portion formed centrally in chamber 10 of nozzle housing 12 . Center flow passage 31 leads into outlet passage 33 which is arranged at an angle relative to the axis X-X. As can be seen in FIG. 1 , water flowing through the flow path thus flows from a water source (not shown) into the output drive shaft 5 of sprinkler body 4 , out through flow opening 25 of output drive shaft 5 and into nozzle housing 12 , through outlet passage 33 and exiting the nozzle housing 12 after passing through a nozzle 34 disposed in outlet passage 33 for distributing a flow of water in accordance with a profile or range enabled by nozzle 34 .
[0032] Nozzle 34 is removably secured in the outlet passage 33 of the flow path in the nozzle housing 12 . The removable nozzle 34 is retained in place by a range control screw 38 . Furthermore, a turning and flow straightening guide 16 is provided in the flow path just upstream of the nozzle 34 in the flow passage 33 .
[0033] The distribution range and/or profile of the stream exiting nozzle 34 can be controlled by range control screw 38 , which is provided in an opening 44 in nozzle housing 12 which is aligned with nozzle 34 in outer passage 33 . Range control screw 38 controls the distribution range by deflecting the flow stream exiting through nozzle 34 , and is accessible for adjustment from the top of nozzle assembly 2 .
[0034] FIG. 1 also shows a second hollow shaft 6 which is concentric with output drive shaft 5 and is used for setting the arc of oscillation by rotationally positioning one arc control contact relative to the other. An arc setting gear 7 is attached to the outer hollow drive shaft 6 by serrations formed on one or both interfacial surfaces. The contacting edges between arc setting gear 7 , sprinkler housing 4 and outer shaft 6 are sealed by an “O” ring to the stationary sprinkler housing 7 to prevent water from penetrating into the sprinkler housing.
[0035] As can be seen in FIGS. 4 and 4 A, arc setting gear 7 engages a gear 69 formed at the base of an arc set shaft 71 , which can be accessed from the top of nozzle assembly 2 to set the arc of oscillation. An arc set indicator 50 is viewable at the top of nozzle assembly 2 . Optionally, arc set indicator 50 can be used to also set the arc from the top of the nozzle housing as well as serving as an indicator, instead of or in addition to shaft 71 as an arc set controller. The arc set indicator 50 includes a gear 68 which is engaged with an intermediate idler gear 80 , which in turn is engaged with a gear 70 of arc set shaft 71 . Thus, arc set indicator 50 is connected to arc setting gear 7 via gear 69 of shaft 71 , gear 70 of shaft 71 , idler gear 80 , and gear 68 of arc set indicator 50 .
[0036] Idler gear 80 is provided between gear 70 on connecting shaft 71 and gear 68 of arc set indicator 50 for reversing the rotation direction of the arc setting indicator 50 from that of the rotation movement of the arc control contact member being set. This is an important feature since it allows the arc set shaft 71 and the indicator 50 to be turned in the same rotational direction as a change in the arc of oscillation occurs. That is, the indicator will reflect an increase in arc of oscillation by turning in the same direction that the arc set shaft 71 is being turned to effect such an increase, for example. Also, when nozzle housing 2 is rotated to its fixed side of the arc, the indicator will then point to where it will oscillate to for ease of arc setting. This is advantageous because to increase the arc of oscillation, e.g. by rotating the arc set shaft in the clockwise direction, the arc control contact that is being rotated clockwise must be shifted further counter-clockwise so that it does not trip the reversing mechanism as soon. This aspect of controlling the arc of oscillation is discussed more fully in, for example, U.S. Pat. No. 4,901,924.
[0037] Additionally, arc of oscillation setting of the output drive shaft is more thoroughly discussed in U.S. Pat. Nos. Re 35,037; 5,417,370; and 4,901,924, the disclosures of which are hereby fully incorporated by reference.
[0038] Nozzle housing assembly 2 includes a housing body 12 and a bottom plate 11 attached to housing body 12 by sonic welding or other attachment means, to thereby define a chamber 10 in the nozzle housing 12 . A shut off valve 9 is formed as a simple slidable shut off piece 13 and is positioned in chamber 10 across the center flow passage 31 of the flow path through sprinkler body 4 and nozzle housing 12 at the top of output drive shaft 5 . Shut off valve 9 includes a valve gate 17 formed as an opening in slidable piece 13 , and is slidable between a fully opened position in which valve gate 17 is aligned with opening 25 in the flow path ( FIG. 2 ), and a fully closed position in which valve gate 17 is moved entirely out of the flow path such that flow passage 31 is blocked at opening 25 of drive shaft 5 ( FIG. 3 ). Slidable shut off valve 9 also includes gear teeth formed along one side edge for engaging the gear of shut off valve actuation shaft 20 ( FIGS. 2, 4 ), whereby valve 9 is moved between the fully opened position and the fully closed position by turning shut off valve actuation shaft 20 . Moreover, slidable valve piece 13 is guided by guide rails 14 formed on nozzle housing bottom plate 11 , while being moved by the gear of actuation shaft 20 . An “O” ring seal 30 is shown surrounding the flow passage 31 at opening 25 into the nozzle housing, to serve as a water tight seat for the valve piece 13 .
[0039] A recess 15 is formed on the underside of sliding shut off valve member 13 to allow flow to continue at full pressure to a secondary stagger passage nozzle 41 which is separated from the primary nozzle, to provide water coverage fall out close-in to the sprinkler.
[0040] As further shown in FIG. 1 , a recess 42 is formed at and extends around the top of nozzle housing 12 . A plate 39 and a rubber cover 40 are received in recess 42 , wherein the plate 39 provides rigidity for supporting the rubber cover 40 and is attached to the nozzle housing 12 by sonic welding or other attachment method. Plate 39 has openings where required, such as for exposing the arc set indicator 50 , the shut off valve actuation shaft 20 , etc.
[0041] Preferably, the rubber cover 40 is fixed in the recess 42 with the plate 39 by rubber holding plugs fitting into holes in the plate 39 (not shown). However, other holding devices can be used. An opening 56 in rubber cover 40 is aligned with opening 44 in the nozzle housing 12 to access the stream-deflecting range control screw 38 through a slit 58 in rubber cover 40 . An “arrow” marked on cover 40 indicates radial the position of the stream outlet opening 33 so that it can be quickly determined with a glance at the top of nozzle housing assembly 2 . Also, arc set indicator 50 extends through an opening 64 in the rubber cover 40 aligned with an opening 48 in plate 39 and to the top surface of the rubber cover 40 .
[0042] Arc set shaft 71 and flow throttling and shut off valve actuation shaft 20 , as seen in FIG. 4 , extend to the top of rubber cover 40 and are accessible from the top through holes 95 and 96 formed therein. The position of the shut off valve can also be viewed and/or indicated at the top cover 40 , since less than one turn is required for full opening or closing of the flow shut off valve.
[0043] Referring now to FIG. 5 , a second preferred embodiment of the present invention is shown in which an upper portion of a rotatable sprinkler 101 includes a cylindrical nozzle housing assembly 102 mounted for rotation about axis X-X on top of a stationary sprinkler body assembly 104 . The stationary sprinkler body assembly 104 is connected to a source of water and has an opening 103 at its upper end through which an output drive shaft 105 exits stationary sprinkler body 104 (riser assembly) for connecting to nozzle housing assembly 102 .
[0044] The output drive shaft 105 is hollow as shown in FIG. 5 , and is attached to nozzle housing assembly 102 through a snap collar 108 which can be glued or sonic welded to the nozzle housing 115 .
[0045] A flow path is defined from the water source through output drive shaft 105 , into a central cylindrical chamber 169 formed in nozzle housing 115 , and through a side passage 133 arranged at an angle relative to axis X-X and extending to a stream exit opening 132 leading out of nozzle housing 115 .
[0046] A removable nozzle 134 is fitted in stream exit opening 132 of nozzle housing 115 , and is held in the nozzle housing by a stream break-up or deflection screw 138 . The nozzle has a primary stream exit opening 141 and optionally may have one or more secondary flow openings 140 for close-in stream break-up and coverage by the sprinkler. Flow straightener 150 is provided upstream of the nozzle for guiding a flow stream flowing through the flow path through sprinkler 101 after the change in direction from the vertical orientation of cavity 169 to the angled orientation of side passage 133 .
[0047] Flow from the sprinkler body assembly 104 up through the nozzle drive shaft 105 and into the nozzle housing 115 and to the nozzle 134 is controlled by a sleeve valve 160 and can be shut off to allow removing and/or changing the nozzle 134 to a different nozzle for effecting a different flow rate or stream angle, if desired, even when the sprinkler is connected to a pressurized source of water.
[0048] The rotary sleeve valve 160 has an opening 161 at least the size of the transition area forming the junction between the central portion of the flow path and the angled side passage 133 , and can be operated by turning a geared operator screw 165 to align the opening 161 in sleeve valve 160 with the side passage 133 in the nozzle housing 102 .
[0049] As the secondary opening 140 of nozzle 134 is downstream of valve opening 161 , flow to secondary nozzle 140 is throttled or opened and closed along with flow to the primary nozzle opening 141 .
[0050] Sleeve valve 160 has gear teeth 162 formed around its top end, as shown in FIG. 5 , to cooperate with gear teeth on the operator screw 165 , and is configured to rotate about axis Y-Y in cavity 169 . The operator screw 165 can extend to the top of nozzle housing assembly 102 so as to allow opening and closing the valve from the outside during sprinkler operation.
[0051] The gear ratio of the operator screw 165 to the sleeve valve gear 162 can be made 1:1. Since a full revolution of the operator screw 165 is not required to open and close the sleeve valve 160 , an arrow head recess 168 may be provided on the top of operator screw 165 to indicate a valve open or closed position on the top of the sprinkler nozzle housing assembly 102 .
[0052] A third preferred embodiment of the present invention is shown in FIG. 6 . This embodiment is similar to the second embodiment in that a nozzle housing assembly 202 is rotationally mounted on a stationary riser assembly 204 , and includes a rotatable flow shut off valve 260 mounted in the nozzle housing around the flow path for intersecting the same. Flow shut off valve 260 , however, is conically-shaped and has a valve opening 261 intersecting the flow passage 233 through the nozzle housing assembly 202 , at a position between the removable nozzle 241 and a flow straightening element provided in the flow path.
[0053] Nozzle 241 may also include a secondary nozzle area 250 . As in the case of FIG. 5 , flow to secondary nozzle 250 is throttled or opened and closed along with flow to the primary nozzle opening.
[0054] The conically-shaped flow shut off valve member 260 is operated by gear teeth 262 formed around its bottom end and connected for external operation from the top or side of nozzle housing assembly 202 by gear 265 .
[0055] In this embodiment, nozzle housing 215 includes a centrally positioned arc set shaft 275 which is concentric with the nozzle drive shaft 205 and which is connected to the top of nozzle housing 215 via an arc set indicating and setting mechanism. As shown in FIG. 6 , the arc set indicating and setting mechanism includes an arc set indicating cylinder member 280 having an upper smaller section 282 rotatably fitted in a correspondingly sized cylindrical opening 283 in the nozzle housing 215 .
[0056] The arc set indicating cylinder member 280 has a lower larger section 284 . An “O” ring seal 286 is provided to prevent flow from leaking to the outside while allowing the arc set indicating member 280 to be turned to set a desired arc of oscillation of the nozzle housing assembly 202 by the rotary drive mechanism (not shown) housed in the sprinkler body housing assembly 204 . Such an arc set control mechanism is shown and described in U.S. Pat. No. 4,901,924, issued Feb. 20, 1990 and U.S. Pat. No. 5,417,370, issued May 23, 1995, the disclosures of which are incorporated herein by reference as though fully set forth.
[0057] FIGS. 7 and 8 show a fourth preferred embodiment of the present invention, which includes the nozzle housing assembly and flow shut off valve described above in connection with the embodiment shown in FIG. 5 . The fourth embodiment is a variant of the second embodiment in which a removable nozzle 334 is now retained at 380 in the nozzle housing assembly 302 by a rotatable nozzle retention and flow shut off control ring 375 around the outside of the cylindrical nozzle housing 315 .
[0058] Here, nozzle 334 includes a primary opening 350 and one or more secondary openings 352 , again downstream of a rotary shut off and throttle valve 360 described below.
[0059] The nozzle retention and flow shut off control ring 375 as shown in FIG. 8 has recesses 390 and 391 which enables nozzle 334 to be removed from nozzle housing 315 when control ring 375 is rotated so that one of recesses 390 and 391 is aligned over nozzle 334 . When neither of recesses 390 and 391 are aligned with nozzle 334 , control ring 375 forms a barrier to thereby retain nozzle 334 in the nozzle housing 315 against the water flow pressure forces.
[0060] The nozzle retention and flow shut off control ring 375 is connected to the rotary sleeve valve 360 by gear teeth 376 formed around the inside circumference of the nozzle retention and flow shut off ring 375 . Gear teeth 376 cooperate with teeth 366 formed on geared operator screw 365 , which teeth 366 are in turn connected to teeth 362 of the rotary sleeve valve 360 for rotating the sleeve valve to align opening 361 formed in the barrel of the sleeve valve 360 with flow passage 333 in the nozzle housing 315 .
[0061] As previously described with respect to the embodiment of FIG. 5 , such arrangement opens and closes off a flow to the removable nozzle 334 .
[0062] Because control ring 375 has a greater diameter than that of sleeve valve 360 , the inner circumference of control ring 375 is capable of accommodating more gear teeth 366 . For example, a 40° rotation of the control ring 375 may achieve a 120° rotation of the rotary sleeve valve 360 . This is more than enough to rotate the rotary sleeve valve 360 to fully open or close flow to the removable nozzle 334 . Preferably, therefore, rotary sleeve valve 360 has a barrel top 367 , as shown in FIG. 7 , which is exposed at the top 303 of nozzle housing assembly 302 to directly indicate the position of flow shut off valve 360 , i.e. whether the valve is open or closed or at a position in-between.
[0063] A stream deflection lug 392 and a stream break-up lug 393 are shown in FIG. 8 as elements attached to the rotatable nozzle retention and flow shut off control ring 375 .
[0064] Teeth 376 around the inside diameter of control ring 375 may be omitted beyond a rotational position of the control ring 375 in the counter-clockwise direction, as shown in FIG. 8 , for example, at which the flow shut off valve 360 is fully opened, and beyond the rotational position in the clockwise direction at which the flow shut off valve 360 is fully closed. This will allow the ring to continue to be rotated to the right (counter-clockwise) once the flow shut off valve 360 is fully opened to enable a full stream to flow to the nozzle, which thereby enables other functions to be associated with the control ring 375 , such as mounting the flow break-up lug 393 or flow deflection lug 392 on the control ring 50 . The additional functional features may then be rotated to intercept the flow stream from the nozzle 334 in the primary flow opening 341 to produce the desired stream modification results.
[0065] Also, continued rotation of the nozzle retention and flow shut off control ring 375 to the right (counter-clockwise) beyond the fully opened position of valve 360 will bring recess 391 in the ring 375 into alignment with nozzle 334 . Since the gearing for closing the flow shut off valve 360 has been omitted for this portion of the control ring 375 , the valve 360 is still open such that when recess 391 is moved into alignment with nozzle 334 , the flow pressure can be used to blow the now unrestrained nozzle out of the nozzle housing 315 so that another nozzle configuration maybe installed.
[0066] Upon rotating the control ring 375 back to the left (clockwise) so that teeth 376 around the inside surface of ring gear 375 again engages teeth 366 of operator screw 365 , flow shut off valve 360 will again be rotated towards the closed position. This arrangement is configured so that when recess 390 is aligned with nozzle 334 , no flow or pressure is present in outlet passage 333 in the nozzle housing so that nozzle 334 may be removed for cleaning or substitution with a different nozzle, for example.
[0067] After insertion of a new nozzle or re-insertion of the one removed, control ring 375 may be again rotated to the right (counter-clockwise) in which nozzle 334 is retained in the nozzle housing 315 by edge 380 of the ring 375 , such as the position shown in FIG. 8 , wherein continued rotation of ring 375 will re-open flow shut valve 360 by aligning flow opening 361 in the valve 360 sleeve with flow passage 333 in the nozzle housing 315 .
[0068] As shown in FIGS. 7 and 8 , the removable nozzle 334 preferably includes an alignment and removal lug 395 at the bottom of the nozzle 334 . A recess 396 with sloped sides is formed in the nozzle housing 315 to cause nozzle 334 to be properly set and in the same position each time a nozzle is just installed into the nozzle housing side passage 333 . Also, a tool may be inserted into recess 396 behind the alignment and retention lug 395 to manually pry or pull the nozzle 334 out from the nozzle housing 315 when the nozzle is not retained by the ring 375 . As previously described, the nozzle 334 may be blown out with the ring 375 positioned with recess 391 aligned with the nozzle, if desired.
[0069] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. For example, although the present invention is described above as being preferably used in rotary driven sprinkler, it is noted that the present invention may also be useful in stationary sprinklers or sprinklers having a non-rotational spray pattern. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A flow shut off or throttling valve is provided in a sprinkler nozzle housing to enable a nozzle to be changed without having to turn off a flow pressure source. The valve intersects a flow path through the nozzle housing and has an opening such that when the opening is aligned with the flow path, a flow stream can flow unobstructed through the flow path. The valve is movable between a fully open position in which the opening is aligned with the flow path and a closed position which blocks the flow stream from flowing to a nozzle disposed at an outlet passage of the flow path. The valve may be constructed to be either slidable or rotatable between the two positions, and is actuated by a gearing arrangement which is operable at the exterior of the nozzle housing. The external valve actuator may function as a physical barrier to retain the removable nozzle in the nozzle housing when the valve is open and to disengage the nozzle when the valve is closed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a tool for the pipe fitting trades, particularly in gas pipe plumbing. In particular, the invention relates to a tool for holding a T-connector in position when torquing the perpendicular third nut on the T-connector to prevent damage to the other connections.
[0003] 2. Description of the Related Art
[0004] When plumbing gas lines, e.g., propane or natural gas, T-connectors with compression or flared fittings are often used to divide gas flow from a source to two or more appliances. The T-connectors are generally made of brass and include three nuts for compression fit of three copper lines. Each copper line must be flared before tightening the nut down on the T-connector. For purposes of the present application, the first and second nut will be the two that are in-line, or coaxial, while the third nut will be perpendicular to the first two, thus forming the downwardly extending leg of the “T”.
[0005] A problem occurs when torquing (either tightening or loosening) the third nut while one or both of the first and second nuts are attached to copper line. Torque applied to the third nut is transmitted to the T-connector body, which places strain on the first and/or second connections. An opposite torque should be applied to the T-connector itself to balance and counteract the torque applied to the third nut to prevent damage to the flared ends of the copper lines at the first and/or second connections. Past practice has been to use an adjustable wrench extending at an odd angle from the top of the “T” in an attempt to hold the T-connector in place while torquing the third nut. Unfortunately, it is very difficult to prevent a significant net torque against the T-connector using an adjustable wrench on the T-connector itself. If the net torque is too great, damage to the flared ends of the copper pipe could result, in which case a leak can occur.
[0006] It has not, to the inventors' knowledge, heretofore been recognized that many such leaks can be prevented if the T-connector is properly immobilized during the torquing operation. Neither has there been a satisfactory tool available to immobilize the T-connector when torquing the third nut by applying a counteracting torque to the T-connector.
[0007] U.S. Pat. No. 5,333,821, issued Aug. 2, 1994 to Lee, discloses a fan pipe holder for a soldering iron. The device comprises a plurality of opposed ribs connected by spine. The ribs and spine are bent into a desired configuration from a single sheet of flat stainless steel. This device is not suitable for holding a T-connector, since it is not sized to fit over the first two nuts of a T-connector, is not stiff enough to immobilize the T-connector, and does not include a handle.
[0008] Japanese Patent No. 54-6,126 teaches a rain-pipe holder for supporting rigid cylinders on either side of soft bellows. This device is also not suitable since it not sized to fit over the first two nuts of a T-connector, nor is it stiff enough to immobilize the T-connector when torquing the third nut. In addition, it does not include a handle.
[0009] Japanese Patent No. 08-300,267 discloses a pipe holder used when making a coaxial connection. This device uses spring-loaded clips to maintain two pipes in alignment when making a connection. It is not suitable for immobilizing a T-connector. The clips would not be strong enough to maintain a firm hold on the T-connector, even if they were positioned close enough together to both engage the T-connector. Furthermore, the handle extending between the clips does not enhance a person's leverage over what would be available simply by grasping the T-connector itself.
[0010] None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a T-connector holding tool and method solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0011] The T-connector holding tool of the present invention is a hand tool for immobilizing or applying a torque to a T-connector. The tool has an elongated handle portion and a head portion fixed to the handle portion. The head portion includes a pair of rigid claws, each including an interior surface sized to capture a corresponding one of two aligned nuts of the T-connector. When applying a torque to the third nut of a T-connector, the T-connector is immobilized by capturing the aligned first and second nuts and applying a counteracting torque to the T-connector, said counteracting torque being opposite the torque applied to said third nut.
[0012] Accordingly, it is a principal object of the invention to prevent leaks at T-connector connections.
[0013] It is another object of the invention to prevent leaks at T-connector connections by immobilizing the T-connector while torquing the third nut.
[0014] It is a further object of the invention to immobilize the T-connector by capturing the first and second nuts in a pair of claws.
[0015] Still another object of the invention is to immobilize the T-connector by allowing a person to apply a counteracting torque to the T-connector on an axis that is coincident with the axis of the third nut.
[0016] It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
[0017] These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an environmental, elevational view of a T-connector holding tool according to the present invention.
[0019] FIG. 2 is a perspective view of an interchangeable head of the T-connector holding tool shown in FIG. 1 as seen from the bottom of the head.
[0020] FIG. 3 is a perspective view of a handle of the T-connector holding tool of the present invention, matable with the interchangeable head of FIG. 2 FIG. 4 is an elevational view of the T-connector holding tool according to the present invention.
[0021] FIG. 5 is an environmental, elevational view showing an intermediate step in the operation of the T-connector holding tool.
[0022] FIG. 6 is a perspective view of an alternative embodiment of the interchangeable head shown in FIG. 2 .
[0023] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] The T-connector holding tool of the present invention is useful in immobilizing a T-connector when torquing the third nut thereof. The tool will now be described in detail with reference to FIGS. 1-4 . A T-connector is a connector having three pipe connections generally used for splitting off a flow of fluid. For the purposes of discussion, a first and second connection are in-line or coaxial, forming the top of the “T” shape of the T-connector. The third connection is on a stem extending perpendicularly from the axis of the first two connections, forming the depending leg of the “T”.
[0025] FIG. 1 shows a T-connector 20 that includes a body with three compression fittings disposed in the shape of a “T”, as described above. When torquing third nut 22 of T-connector 20 , it is commonly required that some counteracting torque be applied to the body of T-connector 20 , to prevent damage to flared ends (not shown) of copper pipes 24 , 26 fit to the first and second nuts of T-connector 20 .
[0026] T-connector holding tool 50 can be used to immobilize, or apply a counteracting torque, to T-connector 20 when torquing third nut 22 , thereby ensuring no damage to the remaining connecting pipes 24 , 26 and reducing the overall potential for leaks.
[0027] Handle 54 is placed so that it extends parallel to pipes 24 and 26 . Head 52 is attached to handle 54 . Head 52 includes two pairs of rigid claws 56 , 58 . Claws 56 , 58 extend on either side of the first and second nuts of T-connector 20 . Thus, when a lateral force is applied to handle 54 , a torque is generated in T-connector 20 that is coincident with the axis of third nut 22 .
[0028] The structure of head 52 will now be described in more detail with reference to FIGS. 2 and 4 . Head 52 includes a cylindrical body 60 extending between a claw 56 and a claw 58 . Each claw 56 , 58 is formed from two jaws rigidly connected to body 60 and has a cylindrical inner surface 57 . The claws 56 and 58 are in parallel, spaced relation, so that the cylindrical inner surfaces 57 define an imaginary cylinder having axis 59 . Each cylindrical surface extends more than halfway around the circumference of the imaginary cylinder. Axis 59 extends parallel to body 60 , and the radius of cylindrical surface 57 is chosen to be slightly larger than the corner-to-corner diameter of the first and second nuts of the T-connector. Thus, each claw 56 , 58 is shaped and positioned to capture one of the first and second nuts of the T-connector. By “capture” it is meant that lateral movement, i.e., translation in a direction other than along its axis, is prevented. For each size T-connector (each used for different pipe diameters), there will be a different size head 52 . Head 52 may be thought of as two parallel, spaced apart crow's foot wrenches joined together by a cylindrical body, except that claws 56 and 58 have a smooth, arcuate bore instead of having hexagonal points defined therein adapted for gripping the nut. Of course, claws 56 and 58 may have hexagonal points defined therein if so desired.
[0029] Head 52 includes hole 64 extending through body 60 and a socket portion 62 for engaging handle 54 as will now be described. Head 52 can be detached and reattached to handle 54 using a snap connection. Handle 54 , shown by way of example in FIG. 3 , includes a handle portion 70 and a lug 74 extending longitudinally from and coaxially with handle portion 70 . Handle portion 70 may be about eight inches long (20 cm) and lug 74 may be about 3 inches long (8 cm). Handle 54 also includes a square drive snap connector 72 , e.g., a ½ inch square drive, having a spring-loaded ball bearing 75 extending partially therefrom in the manner well known and understood in the art of hand tools. Spring-loaded ball bearing 75 engages one of detents 65 formed inside the socket 62 at the bottom end of head 52 . Thus, head 52 is attached to handle 54 simply by inserting lug 74 of handle 54 into hole 64 formed in head 52 until snap connector 72 snaps into place, i.e., spring-loaded ball bearing 75 engages one of detents 65 . The top end of lug 74 is cylindrical, sliding into a cylindrical bore defined in the top end of head 52 .
[0030] FIG. 6 shows an alternative embodiment of head 52 wherein socket portion 62 extends transversely through cylindrical body 60 . Thus, when inserted in socket 62 , handle 54 will extend generally perpendicularly axis 59 but not in the same plane.
[0031] Handle 54 and head 52 are made of machined aluminum or aluminum alloy, but of course other known materials and manufacturing methods that are well known in the hand tool industry are contemplated. However, it is desirable that T-connector holding tool 50 be rigid and durable. For example, steel, stainless steel, and/or lightweight composite materials may be used in the production of T-connector holding tool 50 . Handle portion 70 of handle 54 may be dipped in or otherwise coated or covered with elastomeric material (not shown) to provide an improved grip and comfort. Handle portion 70 may be knurled, etched, or finished in another known fashion to improve the grip and aesthetics.
[0032] An additional head 52 is manufactured for each commonly sized T-connector. T-connectors are most commonly are made for quarter-inch pipe, three-eighths inch pipe, one-half inch pipe, and five eighths inch pipe. It is contemplated that a head 52 be produced for each size T-connector. By providing interchangeable heads, considerable space can be saved in the technician's toolbox. However, it is of course also within the scope of the invention that each size head 52 have a handle 54 such that handle 54 and head 52 are produced as a single contiguous piece of metal or other rigid durable material.
[0033] Referring now to FIGS. 1 and 5 , a short explanation of the use of T-connector holding tool will now be described. Because cylindrical surface 57 extends more than halfway around the circumference of the (imaginary) cylinder it defines, claws 56 , 58 cannot slide laterally over first and second nuts 29 ( FIG. 5 ). As shown in FIG. 5 , T-connector holding tool 50 is first placed in the intermediate position shown, with one of claws 56 , 58 placed between first and second nuts 29 and the other of claws 56 , 58 placed adjacent T-connector 20 . Then, T-connector holder 50 is slid axially in the direction of arrow 80 until it is in the position shown in FIG. 1 , with each of claws 56 and 58 snuggly encircling each of first and second nuts 29 .
[0034] Now, the technician, using a wrench to torque (i.e., tighten or loosen) third nut 22 , uses handle 54 of T-connector holding tool 50 to balance torque transferred from third nut 22 to T-connector 20 . Handle 54 can be held relative to pipe 24 , or the technician can simply utilize handle 54 to push against as leverage against the handle of the wrench (not shown) used to torque third nut 22 . When a lateral force is applied to handle 54 , opposite lateral forces are applied to each of the first and second nuts of T-connector 20 , thereby providing a net torque against T-connector 20 that is coincident with the axis of the third nut. Thus, it is possible to apply a balancing or counteracting torque when torquing the third nut.
[0035] Various modifications of the instant tool are envisioned. For example, cylinder 60 may include one or more holes to permit handle lug 74 of handle 54 to enter at various angles to accommodate T-connectors in locations otherwise inaccessible to T-connector holding tool 50 . For example, an additional hole extending through cylinder 60 having an axis perpendicular to hole 64 and skew to axis 59 can be provided. Additionally, rather than snap connection, a screw connection or other known type of temporary connection may be used.
[0036] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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A T-connector holding tool is a tool for immobilizing or applying a torque to a T-connector. The tool has an elongated handle portion and a head portion fixed to the handle portion. The head portion includes a pair of rigid claws, each including an interior surface sized to capture a corresponding one of two aligned nuts of the T-connector. When applying a torque to the third nut of a T-connector, the T-connector is immobilized by capturing the aligned first and second nuts and applying a counteracting torque to the T-connector, the counteracting torque being opposite the torque applied to the third nut.
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BACKGROUND OF THE INVENTION
The present invention relates, in general, to the field of photography and, more specifically, to photographic apparatus having manually operable dual actuators for facilitating sequential actuation of two different modes of apparatus operation.
The present invention is directed to improvements in photographic apparatus of the type generally disclosed in commonly-assigned copending applications: Ser. No. 54,598, entitled "Camera With Folding Flash Unit", filed July 3, 1979, by Bruce K. Johnson and George D. Whiteside; and Ser. No. 54,652, entitled "Camera With Telescoping Dual Actuators", filed July 3, 1979, by Carl W. Davis and Joseph E. Murray, Jr.; respectively. These cameras essentially include an electronic strobe-type flash unit powered by a battery which battery also powers the camera's electrical system. To prevent the battery's power delivery rate being exceeded so as to minimize its power drain and to prevent actuation of an exposure cycle before the flash is fully charged when it is desired to fire the latter, a sequential actuating system is provided. Such a system operates essentially to charge the flash unit storage capacitor immediately preceding the film exposure and processing cycle.
For instance, the approach taken in the aforenoted application Ser. No. 54,598 provides sequential actuation. This is, in part, accomplished by a dual actuator housed in an elongated actuator housing formed on one side of the camera. Extending from the actuator housing towards the camera user is a first actuator push button and longitudinally opposed therefrom is a forwardly facing second actuator button. In use, the first actuator push button is pushed forwardly for causing closing of an internal electrical switch. Closing of this switch allows the film pack battery to charge a flash unit capacitor. When charging is complete, as indicated by a visual signal in the viewfinder, the user pushes rearwardly on the second button. This latter movement causes an internal slider arrangement to effectively close a second internal electrical switch for initiating an automatic cycle of camera operation including film exposure with supplemental artificial illumination provided by the charged flash unit. This system works satisfactorily. There is, however, potential for problems.
For example, it might be somewhat awkward for the user to refrain from pushing rearwardly on the second forward facing push button while simultaneously with his second finger pushing forwardly with his thumb on the rearwardly facing first actuator push button. As a consequence thereof, inadvertent actuation of the exposure cycle could arise.
In anticipation of a user inadvertently operating the actuators in the wrong sequence, additional logic circuitry would be necessary for electrically blocking out an exposure start signal which is produced by operation of the second actuator push button. However, use of additional logic circuitry denies the user the option of initiating an exposure cycle of camera operation exclusive of the flash firing. This would be a problem whenever it is desired to, for example, take an exposure through a glass window wherein it is not desired to fire the flash unit. Additionally, battery drainage is a potential problem because of the absence of an inhibiting circuit for preventing inadvertent operation of a flash charge actuator when the camera is not being used.
The approach taken in copending U.S. patent application Ser. No. 54,652 overcomes the aforenoted potential for problems by eliminating the forward and aft placement of the first and second actuators as well as allowing the bypassing of the flash charging actuator when directly initiating an automatic cycle of camera operation. As described in this application, a dual actuating telescoping push button arrangement is provided. Specifically, a small forward inner button is initially depressed for effecting strobe charging. Thereafter, the photographer presses an outer button without releasing the inner button. The automatic cycle of camera operation is initiated upon the outer button effecting contact with an internal switch in the camera. While the foregoing approach successfully eliminates many of the potential problems associated with the foregoing described unit, there nevertheless exists a potential problem in that a user may inadvertently press the wrong button.
Other examples of cameras having dual actuators of the general type noted are referred to in commonly-assigned U.S. Pat. Nos. 4,001,640 and 4,085,414. It should be noted, however, that use of these dual actuators are somewhat awkward and their structure is not compatible with the noted internal slider switching arrangements of the foregoing cameras. This slider switching arrangement has proven it to be an extremely reliable device in, for example, the Pronto! and One Step cameras manufactured by the Polaroid Corporation, Cambridge, Mass.
SUMMARY OF THE INVENTION
In accordance with the present invention, the aforenoted potential for problems of inadvertent and improper use of dual actuators of the type mentioned above are substantially diminished. This is achievable by provision of an improved actuator apparatus for greatly inhibiting improper sequential actuation of dual actuators.
As in prior dual actuators for use with photographic apparatus having a housing, an artificial illumination device is connected to the housing and is energizable by energizing means for providing a pulse of illumination. An exposure control system is provided for initiating an exposure interval upon being energized by the energizing means. A first means is provided with a manually accessible portion and is movable between an off or inoperative position to an operative or charging position in response to being manually displaced so that during movement toward the operative position the energizing means energizes the illuminating device. A second means having a manually accessible portion is operable for movement between an off or inoperative position and an operative or exposure position. When the second means is in the operative position, the energizing means energizes the exposure control system for initiating exposure.
In an illustrated embodiment, the first means includes a cover connected to a portion of the housing for movement between the inoperative and operative positions. When in the inoperative position the first means is in substantially covering relation to the manually accessible portion of the second means to thereby inhibit actuation of the latter's manually accessible portion. Moving this cover to the charging position connects the energizing means to the artificial illuminating device for energizing the latter. Simultaneously, such movement significantly uncovers the manually accessible portion of the second means. Advantageously, this facilitates sequential actuation of the second switch for initiating exposure control.
Among the objects of the invention are, therefore, the provision of an improved actuator apparatus for greatly inhibiting inadvertent sequential operation of one of a pair of actuators; the provision of an improved actuator apparatus which inhibits inadvertent sequential operation while simultaneously permitting independent actuation of either one of the actuators; and the provision of an improved camera apparatus having a dual actuator for greatly inhibiting inadvertent sequential actuation of one of a pair of actuators while simultaneously permitting independent actuation of either one of the pair of actuators.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow when taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a camera incorporating the improved dual actuator of the present invention;
FIG. 2 is an enlarged elevational view, partly broken away, illustrating details of the dual actuator when in one condition of operation;
FIG. 3 is a view similar to FIG. 2 but showing the dual actuator in another position of operation;
FIG. 4 is a perspective view, shown in exploded fashion, of selected components forming one of the actuators of the improved dual actuator system of the present invention;
FIG. 5 is a side elevational view forming one of the actuator arrangements of the dual actuating system of the present invention; and
FIG. 6 is an electrical block diagram of the camera's electrical switch system showing the various electrical switches which are to be actuated by the noted dual actuating system of the present invention.
DETAILED DESCRIPTION
Referring to FIGS. 1-3, the improved camera apparatus 10 includes a camera housing 12 having in a section thereof an electronic flash unit 14. Connected to one side of the housing 12 is a dual actuator arrangement 16 of the present invention. Essentially, the dual actuator arrangement 16 is operative for charging a storage capacitor (not shown) in the flash unit 14 and for initiating an automatic cycle of camera operation including initiating a film exposure cycle. Components of the dual actuating arrangement 16 include a first or pivotal flash charge actuator 18 and a second or slider switch actuator 20.
In this embodiment, the camera 10 is of the self-developing type and is configured for use with a film pack 22 (FIG. 5) of the kind including a stack of self-developing film units 24, as well as a generally flat electrical battery. The battery is for powering the camera's electrical system including the electronic flash unit 14. For a representative example of the film pack, see commonly assigned U.S. Pat. No. 3,877,045.
A bottom base section 26 of the camera housing 12 has a chamber configured for housing the film pack 22 so that the uppermost one of the stacked film units 24 is at the camera's focal plane. Extending forwardly of the base section 26 is a pivotally mounted loading door section 28. For releasably retaining the door section 28 in the closed condition, there is provided a slidable latch 30. The slide latch 30 can be operated so that the loading door section 28 may be pivoted downwardly for providing access to an open end of the film pack receiving chamber. Also, it is to be noted that the loading door section 28 houses a pair of motor driven pressure-applying rollers 32. For facilitating withdrawal of the film units 24 from the film pack 22 when the loading door section 28 is in its closed position (see FIG. 5), the bite of the rollers is in alignment with a film unit withdrawal slot 34. Consistent with the operation of the self-developing cameras of the foregoing type, it will be understood that the uppermost film unit 24 is advanced between the rollers 32 for processing in a well-known manner and then pass through an elongated exit slot (not shown) formed on the front wall of the loading door section 28 to the exterior of the camera.
Again referring to FIG. 1, there is seen an upstanding generally box-like shutter housing section 36. Housed within this section 36 is a majority of the camera's exposure control components. For a more detailed description of the shutter housing in the context of the exposure control components reference is made to the last noted application. Connected to one side wall of the shutter section 36 is the dual actuator arrangement 16. Rearwardly extending from the camera housing 12 is a viewfinder tube 38. Included in the tube is a rear lens 39 which optically communicates with a front lens (not shown) in the front face of the shutter section 36.
Referring back to the flash unit 14, it too is included within the shutter section 36. Such flash unit 14 includes a light output window 40 so as to direct light from the flash unit toward the object to be photographed. It will be appreciated that the flash unit 14 is electrically connected to a flash charge and operating logic circuit positioned within the shutter housing section 36.
The mechanisms employed in the camera 10 for purposes of effecting a complete automatic cycle of camera operation including film exposure and subsequent film processing are set forth in greater detail in commonly assigned U.S. Pat. No. 4,040,072 issued to Bruce K. Johnson and George D. Whiteside on Aug. 2, 1977. For instance, the shutter mechanism includes a pair of overlapping shutter blades of the well-known scanning type. These blades are reciprocally driven by a pivoting walking beam mechanism between positions blocking and gradually unblocking the exposure path through the camera lens to the focal plane by the way of a reflecting inclined mirror (not shown). For driving the blades to the blocking position, a solenoid is provided. When energized, the solenoid overcomes the biasing of a spring which spring generally tends to drive the blades to the unblocking position. Therefore, when the solenoid is deenergized, the spring is effective for driving the blades to the unblocking position. For purposes of maintaining the shutter blades in their scene light blocking condition while at the same time avoiding a power drain for purposes of energizing the solenoid, there is provided a shutter release mechanism. Essentially, the shutter release mechanism, upon commencement of the exposure cycle, will permit the shutter blade spring to drive the blades to the opening position and when the solenoid is deenergized, it will retain the shutter blades in their scene light blocking position despite deenergization of the solenoid. This particular shutter release mechanism does not form an aspect of the present invention. Therefore, details not necessary for an understanding of this invention have been omitted. However, a more detailed description of the foregoing described shutter release mechanism is described in the last noted U.S. Patent.
Reference is now made to the dual actuating arrangement 16 of the present invention. As mentioned, the dual actuating arrangement 16 includes a slider switch actuator 20 of the type disclosed in the aforenoted copending application Ser. No. 54,652. Reference is now made to FIGS. 4, 5 and 6 for better describing switches S 1 , S 2 , S 3 . Since these switches do not per se form an aspect of the present invention, a detailed description thereof will not be presented. However, that structure which leads to a better understanding of the present invention will be set forth. For greater details regarding the structure and operation of these electrical components, reference is made to the last aforenoted application as well as U.S. Pat. No. 4,040,072. S 1 , S 2 and S 3 are mounted on a switch block 58 that is housed within the apron housing section 29. Closing of the S 1 switch acts to electrically connect an electrical battery 42 to an exposure and sequencing control circuit 44, a motor and solenoid control circuit 46 for operating shutter solenoid 48 and an electrical motor 50 for driving the processing rollers, film advance device and the camera sequencing wheel. Moreover, closing of the S 1 switch energizes the solenoid 48 for effecting release of the mechanical shutter latch. Release of the shutter latch allows counterclockwise pivotal movement of a switch actuator 52 (FIG. 5). This movement results in sequential closing of normally open shutters S 2 and S 3 . In this embodiment, the S 2 switch is a power latch switch for maintaining electrical connection of the battery 42 to the circuits 44 and 46. By reason of this, the user is allowed to manually release the slider switch assembly to open S 1 without interruption of the automatic cycle. The S 3 switch is arranged to close after closing of the S 2 switch for providing a logic input signal to the circuit 44 from the battery. This indicates commencement of the automatic exposure cycle. As the shutter blades open, they allow monitoring of the scene lighting conditions. Achievement of this is brought about by a light integrating circuit. This circuit includes a light sensor or photocell 54 and associated therewith a capacitor 56. The photocell 54 and the capacitor 56 are connected for providing a trigger signal or a voltage indicative of the quantity of scene light reaching the sensor on a time basis. Receipt of the trigger signal operates the circuits 44 and 46 for once again energizing the solenoid 48 and for closing the shutter blades to thereby terminate exposure. Following this, the motor 50 is operated for effecting film processing and driving of a sequencing wheel (not shown) for causing reset including the opening of switches S 2 and S 3 .
The S 1 switch includes an elongated top contact 60 and spaced therefrom a bottom contact 62. These contacts 60 and 62 project rearwardly from the underside of an electrically insulating terminal board 64. Only the portions of the S 2 and S 3 switches which also project from the terminal board 64 are shown. This is because they do not pertain to the present invention.
Still referring to the slider switch actuator 20, it includes elongated slider 66 and slide actuator 67. The elongated slider 66 is made of a generally flat molded plastic body having an upper longitudinally extending opening 68 and a somewhat longer opening 70 therebelow. The upper opening 68 provides access for pivot shaft 72 of the switch actuator 52 which is operative for actuating switches S 2 , S 3 . Also, the upper opening 68 permits longitudinal movement of the slider 66 between its first or inoperative position to its second or operative position. Forwardly extending from the slider 66 is a finger 76 and laterally spaced therefrom a rear finger 78. When the slider 66 is in an inoperative position (FIG. 4), the upper and lower contacts 60 and 62 rest, respectively, on fingers 76 and 78; and S 1 is open. When the contacts 60, 62 engage each other, they close switch S 1 (FIG. 5). The force normally pushing the slider 66 to the inoperative position is provided by a biasing spring 80 and the fingers 76, 78 are effective for causing separation of the contacts 60 and 62.
Reference is made to FIG. 4 for better describing the actuator 20. The slider 66 and slide actuator 67 are coupled together for effecting the desired movement from the inoperative to the operative position. A notch coupling flange 82 at the forward end of the slider 66 includes a V-shaped notch 84 for receiving a coupling tab 86 on the slider actuator member 67. In this embodiment, the slider actuator 67 includes an offset or main body portion 88 which is slidably mounted in the actuator housing 69 (FIGS. 2, 3). Formed at the forward portion of the slider actuator 67 so as to be positioned outside the actuator housing 69 is a manually accessible finger operated push button member 90 having a finger accessible push button surface 92. Depending from the push button 90 is a vertically positioned tab 94. Both the push button surface 92 and the vertically extending tab 94 are arranged so as to be conveniently, manually depressed by the index finger of a user. Thus, by pushing inwardly on the push button 90, the slider actuator 67 will also simultaneously move in the slider 66 inwardly against the bias of the spring 80. This effects movement of the fingers 76, 78 to allow the contacts 60 and 62 to come together to close normally open switch S 1 .
Moreover, closing of the S 1 switch energizes the solenoid 48 for releasing the shutter latch to thereby allow counterclockwise movement of a switch actuator 52 to the position shown in FIG. 5. This movement causes, as noted, sequential closing of normally open switches S 2 and S 3 .
The foregoing provides a camera actuator or second means operable upon manual displacement between operative and inoperative positions operable for energizing the exposure control system by having the battery 42 electrically connected thereto.
Reference is made to FIGS. 1-4 for illustrating the pivotal switch system 18 which is operable for charging the flash unit 14. Included in the system 18 is a molded plastic actuating cover 96. The cover 96 is pivotally connected at 98 to the side of the shutter section 36 above the slider actuating housing 69 for pivotal movement between its inoperative or off position (FIG. 3) and its operative or exposure position (FIG. 2). When the cover 96 is in its operative position, the S 4 switch (FIG. 6) is closed for purposes of charging the flash unit 14. When the cover 96 is in its off or inoperative position, it essentially serves to cover the slider switch actuator 20. By virtue of such covering, a camera user is greatly inhibited from manually pushing inwardly on the push button surface 92. Inadvertent closing of the S 1 switch is thus greatly minimized. Accordingly, the likelihood of a user depressing the slider switch arrangements, in an improper photographic sequence, is significantly diminished. Moreover, the cover 96 is formed with an open bottom end. This is for permitting the depending actuator tab 94 to extend beneath a bottom plane defined by the cover bottom; (FIG. 3). In this connection, a user is nonetheless capable of pressing inwardly on the push button tab 94 for effecting closing of S 1 . Because of the positioning of the tab 94 rearwardly of the forward wall 100 of the cover 96 and the relatively small size of the tab 94 in comparison to push button surface 92 it is relatively difficult for a user to inadvertently press the tab for closing the S 1 switch when the cover 96 is in its covering position. Thus, a user would have to specifically intend to press the tab 94. Since the tab 94 is still accessible, independent exposure control operation of the camera is provided without having to actuate the flash unit 14. Thus, for instance, photographs can be taken through a window without the adverse effects brought about by flash.
The cover 96 includes a generally hollow interior defined by opposed end walls 100, 102 and side walls 104. As seen in FIG. 3, the cover 96 covers the actuator housing 69 and the push button 92. A recess 105 is formed on the interior side wall 104 and is sized to accommodate an electrical contact member 106 of switch S 4 (FIG. 3). The contact member 106 extends outwardly from the housing section 36. The end wall 102 is configured and positioned for being easily engaged by a user's thumb. Mounted on an interiorly disposed ledge 108 in the cover 96 is an electrical switch contact element 110 of switch S 4 . The switch contact element 110 is constructed to engage the contact member 106 when the cover is moved upwardly to its operating position. Because of the pivotal connection of the cover 96, a user can easily support the camera bottom with three fingers of the right hand, while using the thumb of the same hand to conveniently pivot the cover 96 to the noted operative position (FIG. 2) for closing S 4 , while having the index finger free to depress inwardly the actuator 67 inwardly for effecting closing of the S 1 switch. The foregoing provides a first means or flash charge actuator operable upon movement between inoperative and operative positions for energizing the flash unit 14.
Closing of the normally open flash charge switch S 4 serves to electrically connect the battery 42 to a flash charge and logic circuit 112 (FIG. 6). This circuit 112 is also electrically connected to the exposure and sequencing control circuit 44, flash unit 14, and a flash charge state indicator circuit 114. This latter circuit 114 includes an indicator, such as a light-emitting diode, which may be seen by the user as he looks through the viewfinder tube 38. Thus, a normal cycle of camera operation is initiated by the sequential actuation of S 4 to charge the flash unit 12 and then S 1 to begin the automatic cycle of camera operation. Such diode indicates the charge state of the capacitor 56 in the flash unit 14. The specific operation of the S 4 switch is more clearly described in the last noted copending application. However, for better appreciating the operation of this invention only those details of S 4 which are necessary will be described. Upon closing of the S 4 switch, circuit 112 charges the storage capacitor 56 in the flash unit 14 while monitoring the state of charge and providing a continuously updated interior signal to the indicator circuit 114. During the exposure phase, the flash charge and logic circuit 112 feeds the appropriate flash fire and quench signals provided by exposure and sequencing control circuit 44 to the flash unit 14.
Based upon the foregoing detailed description, it is believed the operation of the improved dual actuator arrangement 16 of the present invention in terms of operating the camera exposure and the flash unit 14 are readily apparent. However, to briefly supplement the above description the following is set forth.
To actuate the dual actuating switch arrangement 16, the user can initially pivot the cover 96 from its off position (FIG. 3) to its operative condition (FIG. 2). This is accomplished by simply having the end wall 102 pressed generally downwardly by the user's thumb. It will be appreciated that three fingers of the same hand support one side of the camera. Such pivotal movement will effect closing of the S 4 switch because the contact members 106 and 110 are brought into electrically conductive engagement. Owing to gravity, release of the thumb permits the cover 96 to resume its inoperative position. As noted, the flash unit 14 is then appropriately charged so that the flash unit can operate when S 1 is closed. When the cover 96 has been moved to its operative condition, the push button surface 92 is freely accessible to the index finger. Thus, the flash actuating members 66, 67 can now be displaced from their inoperative position to their charging position for effecting closing of the S 1 switch. However, the switch arrangement 18 and the switch actuator 20 provide the user with the option to eliminate the flash operation of the camera by bypassing the flash charge stage. In this instance, the user merely presses inwardly on the tab 94 for closing the S 1 switch without charging the flash unit 14. Because of the arrangement and construction of the cover 96 relative to the push button 90 inadvertent actuation of the push button is greatly inhibited.
Because certain changes may be made in the above-described improved camera without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description as shown in the accompanying drawings shall be interpreted as illustrative and not as limiting.
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For charging a flash device in a photographic apparatus, there is provided a flash charging actuator manually displaceable between an off position and a charge position. For commencing exposure in such apparatus, there is a camera actuator manually displaceable between an off position and an exposure position. The flash charging actuator includes a cover portion for covering a finger engagable portion of the camera actuator when the former actuator is in its off position for inhibiting operation of the latter. Moving the charging actuator to its charge position uncovers the finger engagable portion so that the camera operator can sequentially depress the camera actuator after the flash device has been charged.
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BACKGROUND
[0001] Binary sampling commonly refers to periodically sampling a signal to reduce the signal to a time-indexed series of binary values (0 or 1). In contrast, analog sampling such as commonly used in oscilloscopes generally samples a signal less frequently, but each sample retains information about the analog level of the signal when sampled. The analog level for each sample can be recorded as a multi-bit digital value, in which case, analog sampling generates a series of multi-bit values that approximates the analog signal.
[0002] An advantage of binary sampling is that binary sampling can generally achieve a higher sampling rate than can be practically achieved with analog sampling. For example, a binary sampling instrument, such as a bit error rate tester (BERT), can sample every bit of a high data rate signal, while current analog samplers with analog bandwidths over a couple of GHz are generally limited to a few thousand samples per second. Analog samplers can thus capture only a small fraction of the bits of a high data rate signal.
[0003] Another benefit of binary sampling is that a binary sampling circuit for a given test signal data rate can often be manufactured at a lower cost than an analog sampling circuit suitable for measurement of the signal. The lower cost of binary sampling makes it desirable to try to replicate the capabilities of analog sampling systems using binary sampling systems.
SUMMARY
[0004] In accordance with an aspect of the invention, a binary sampling system can sample a signal to generate test data that is analyzed to extract information about the analog characteristics of the signal. For example, a bit error tester or alternatively a counter counting the number of samples having a particular value can measure the percentages or rates of zeros or ones measured in a signal for a range of sampling thresholds and a range of phase offsets. Derivatives of the measured rate then indicate the density of signal waveforms at the voltage and phase at which the derivative was taken, and plots of the derivative provide similar information to that provided in an oscilloscope trace.
[0005] One specific embodiment of the invention is a test system that includes an analog comparator, a binary sampler, and a counter. The analog comparator compares an input signal to an adjustable threshold level. The binary sampler, which uses an adjustable phase parameter that determines a phase of sampling, samples an output signal from the analog comparator. The counter can then count samples from the binary sampler that have a selected binary state. A processing system can then be used to analyze a set of counts/rates from the counter to determine an analog characteristic of the input signal. The analysis can include, for example, taking a derivative or identifying a threshold corresponding to a characteristic voltage of the signal.
[0006] Another specific embodiment of the invention is a method for analyzing a signal. The method includes: varying a threshold over a first range; varying a phase over a second range; and for each value of the threshold and the phase, determining a rate at which the signal has a voltage above the threshold when sampled at the phase. Analysis of the rates can then determine an analog characteristic of the signal.
[0007] Yet another specific embodiment of the invention is another method for analyzing a signal. The method includes sampling the signal with a binary sampler having an adjustable phase for sampling and an adjustable threshold. The adjustable threshold separates levels of the signal corresponding to different binary states of samples output from the binary sampler. From the sampling, the method determines rates of a selected one of the binary states in the samples output from the binary sampler. Each of the rates is preferably determined for a unique combination of values of the adjustable threshold and the adjustable phase. The rates can then be analyzed to determine an analog characteristic of the signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of a system using binary sampling and bit error rate measurements to determine analog characteristics of a signal.
[0009] FIG. 2 is a block diagram of a system in accordance with an embodiment of the invention using binary sampling and value counts to determine analog characteristics of a signal.
[0010] FIG. 3 is a block diagram of a delay circuit that provides clock signal with an adjustable phase delay.
[0011] FIG. 4 is a plot illustrating how the rate of zero values represented in a signal depends on the threshold level separating voltages representing zero from voltages representing one when a phase for sampling is within the rise time or the fall time of the signal.
[0012] FIG. 5 illustrates how the rate of occurrences of zeros in a data signal depends on the threshold level separating voltages representing zero from voltages representing one.
[0013] FIG. 6 shows how a derivative of the rate shown in FIG. 5 provides traces that indicate analog characteristics of a signal.
[0014] Use of the same reference symbols in different figures indicates similar or identical items.
DETAILED DESCRIPTION
[0015] In accordance with an aspect of the invention, a binary sampling system can analyze analog characteristics of high-frequency or high-data rate signals. For the analysis, the binary sampling system determines the rate of samples having a voltage level above or alternatively below a threshold level (e.g., a rate of samples having value one or zero) for a specific phase of the signal). The rate measurement is then repeated for a range of threshold levels and phases to determine the rate as a function of the threshold (i.e., voltage) and the phase (i.e., time). A derivative of the rate function indicates the density of occurrences of the signal within the ranges of voltage and time and therefore when plotted simulates traces generated in an oscilloscope. The analog characteristics of the signal can thus be determined from the binary sampling.
[0016] In a related measurement process, binary sampling techniques based on bit error ratio (BER) measurements determine analog characteristics of a signal such as a data signal from a system under test (SUT). FIG. 1 illustrates a system 100 using BER-based techniques to measure analog characteristics of a SUT (not shown). System 100 includes a differential amplifier or comparator 110 , a binary sampler 120 , a variable delay circuit 130 , an error compare circuit 140 , a pattern generator 150 , an error counter 160 , and a bit counter 170 .
[0017] During a measurement, the system under test produces a signal DATA representing a known series of binary values, and signal DATA is input to comparator 110 . Comparator 110 compares the analog voltage of signal DATA to a threshold level VT, and generates an output signal that is at a high voltage or a low voltage depending on whether the analog voltage of signal DATA is higher or lower than the threshold level VT.
[0018] A binary sampler 120 samples the output signal from comparator 110 and produces a binary sampled signal having a data frequency that is preferably the same as the data frequency of signal DATA. Alternatively, the data frequency of signal DATA could be an integer multiple of the sampling frequency that binary sampler 120 uses. To control the timing of sampling in the embodiment of FIG. 1 , a variable delay circuit 130 receives a clock signal CLK having the desired frequency, and delays clock signal CLK by a delay that a parameter Φ selects. The delayed clock signal triggers binary sampler 120 and thereby controls the frequency and the phase at which binary sampler 120 samples the output signal from comparator 110 .
[0019] Error compare circuit 140 compares the binary sampled signal from sampler 120 to a binary signal from pattern generator 150 . The binary signal from pattern generator 150 represents a data series that is the same as or derived from the known binary series that signal DATA should represent. A difference between the binary sample from sampler 120 and the known signal from pattern generator 150 indicates a bit error in signal DATA for the parameters VT and Φ used. Error compare circuit 140 triggers error counter 160 to count the errors, and the clock signal (or the delayed clock signal) triggers bit counter 170 to count the total number of bits sampled. The ratio of the error count from counter 160 to the bit count from bit counter 170 indicates the bit error ratio (BER).
[0020] A processing system 180 analyzes the BERs that are measured for a range of threshold levels VT and clock phases Φ. Observing the variation in the BER as the threshold level VT and the sampling phase Φ vary indicates analog characteristics of signal data. For example, when sampling phase Φ corresponds to a time when signal DATA may transition between a low level (e.g., binary zero) and a high level (e.g., binary one), the BER changes dramatically as comparison threshold level VT crosses the characteristic voltage levels of signal DATA at the sampled phase. Analog voltage levels of signal DATA can thus be determined at a series of values of phase Φ to provide information similar to that provided in an oscilloscope trace.
[0021] The analysis techniques available in system 100 as described above use a signal DATA that represents a known binary series, which permits identification of errors and measurement of the BER. Accordingly, such analysis techniques may not be available during normal operation of the system under test when the values of signal DATA are not known.
[0022] FIG. 2 illustrates a system 200 in accordance with an embodiment of the invention that can measure analog characteristics of a signal DT without knowing a specific series of bits represented in signal DT. System 200 includes a differential amplifier or comparator 110 , a binary sampler 120 , a variable delay circuit 130 , a counter 240 , and a data processor 250 . When compared to system 100 , system 200 does not require a pattern generator or an error comparator that are in the BER-based system 100 described above. In alternative embodiments, system 200 can be implemented in a full-featured test system, a low-cost test circuit for circuit self-testing, or an on-chip test circuit for chip self testing. In one specific embodiment, system 200 is a low cost test circuit implemented as a printed circuit assembly.
[0023] In operation, system 200 can determine a count or rate of samples of a signal DT having a voltage below (or alternatively above) a selected threshold level VT at a selected phase Φ of signal DT. In particular, comparator 110 compares voltage of signal DT to the threshold level VT and drives an output signal high or low depending on whether signal DT has a voltage higher or lower than threshold level VT. Binary sampler 120 samples the output signal from comparator 110 at frequency that preferably corresponds to the data rate of signal DT and a phase that the parameter Φ of variable delay 130 selects. The output signal of sampler 120 enables or disables counter 240 , so that counter 240 counts when the binary samples are zero or one (corresponding to signal DT being below or above threshold level VT).
[0024] System 200 can be implemented using well-known devices. For example, in an exemplary embodiment of the invention, comparator 110 is a differential amplifier, and binary sampler 120 is a high speed D flip-flop. If desired, a demultiplexer circuit (not shown) may be included following binary sampler 120 and effectively convert a high frequency bit stream from binary sampler 120 to a lower frequency parallel data stream. Several lower-speed circuits operating in parallel could then implement counter 240 and parts of data processor 250 .
[0025] Delay circuit 130 preferably provides precisely controlled delays to permit phase adjustments in signal DT that may have a frequency greater than 1 GHz. FIG. 3 illustrates one embodiment of a suitable delay circuit 300 . Delay circuit 300 includes a buffer 310 that relays and input clock signal CLK to a phase adjustor 320 . Phase adjuster 320 provides larger scale adjustments of the phase that parameter Φ selects and can be implemented using a commercially available phase adjustor such as an MC100EP195 from ON Semiconductor, Inc. To provide finer phase control, a second buffer 330 feeds the signal from phase adjustor 320 to circuit block 340 that provides a variable capacitance. Circuit block 340 may include, for example, one or more varactor diodes that provide a capacitance that slows transitions in the signal by an amount that depends on parameter Φ. A final buffer 350 drives the delayed clock signal DCLK high or low at times that depend on the transition rate of the signal from circuit block 340 .
[0026] Data processor 250 performs analysis processes that are described further below. In alternative embodiments of the invention, data processor 250 can be implemented in dedicated hardware, firmware executed in a microcontroller, and/or software executed in a computer or other external system.
[0027] System 200 of FIG. 2 does not compare the sampler output to a known waveform but instead counts the number of zeros (or ones) in a signal DT representing unknown data values. System 200 thus uses binary sampling, but not a bit error rate measurement. However, a BER test circuit measurement can determine the rate of zeroes (or of ones) if the “expected” signal generated by pattern generator 150 is all ones (zeroes). Thus, analysis techniques described below may be applied either when sampling circuit 200 or a BER test circuit is available. However, in normal operation, the BER test system must maintain synchronization between a local pattern generator and the input signal because a BER test system compares an input signal to an expected pattern. Therefore many BER circuits are designed to enter a synchronization search mode when the BER is high, for example, when the BER is above about 0.1. In order for a BER tester to be able to reproduce all capabilities of test system 200 , the BER tester must permit disabling of the synchronization search mode. Test system 200 , in contrast, does not require pattern synchronization. Therefore, system 200 can operate even when sampling conditions would produce a high BER. The ability to test signals even in high BER regions may allow certain analyses that are not possible with unmodified BER test systems. For example, signal properties such as rise-time, fall-time, average 1-level, average 0-level, maximum voltage, mask test outside the eye-center, overshoot or 1-level ripple, undershoot or 0-level ripple can be measured or determined.
[0028] In an exemplary embodiment, the count in counter 240 of system 200 is proportional to the rate (sometimes referred to herein as the zero-rate) of occurrences of signal DT being below threshold level VT at the selected phase Φ of signal DT. System 200 can determine comparable zero-rates for other threshold levels and phases by setting the desired parameters VT and Φ and counting zeros for a fixed time. Alternatively, the zero-rate is equal to the ratio of the count from counter 240 and a matching count of the total number of bits. A similar one-rate is proportional to a count of the number of samples above threshold level VT, and the sum of the one-rate and the zero-rate should be equal to the bit rate or frequency of signal DT. In accordance with an aspect of the invention, analog characteristics of a signal can be extracted from zero-rates or one-rates found by binary sampling of the signal using a ranges of phases and thresholds. The following describes examples of using the zero-rates in binary sampling to determine analog characteristics of a signal, but one-rates could be used in a similar manner.
[0029] FIG. 4 illustrates a plot 400 of zero rates as a function of the threshold level VT at a fixed sampling phase that sometimes corresponds to signal DT transitioning between a high level and a low level. Plot 400 illustrates that the zero-rate is zero when the threshold level VT is below a minimum voltage of V 0 MIN of signal DT because all samples have voltage greater than or equal to voltage V 0 MIN . As threshold level VT increases from the minimum voltage V 0 MIN to a maximum voltage V 0 MAX of the voltages representing bit value zero, the rate increases, and then plateaus at a rate 410 corresponding to the probability of signal DT remaining stable at bit value zero for two consecutive bits. In a typical data signal that has a statistically equal chance of retaining or switching binary value, the first plateau rate 410 will be about 25%, which corresponds to the chance of two consecutive bits having value zero. However, for a binary series having other statistical properties, the level of the first plateau rate 410 may not correspond to 25%.
[0030] The selected phase for plot 400 is close to transitions between consecutive bits. In particular, at the selected phase, the average voltage when the signal is rising is voltage VR AVE , and the average voltage when the signal is falling is voltage VF AVE . Plot 400 illustrates the case when the selected phase is early in the rise or fall so that the average rising voltage VR AVE is less than the average falling voltage VF AVE .
[0031] As the threshold VT approaches the average rising voltage VR AVE , the zero-rate increases as more of the cases of voltage rise become less than threshold level VT. A second plateau rate 420 occurs when nearly all samples of the rising voltage at the selected phase are less than the threshold level VT. This plateau rate would correspond to about 50% for a signal representing a binary series in which the probability of value zero is 50%, but plateau rate 420 may not correspond to 50% for a signal having different statistical properties.
[0032] Similarly, as the threshold level VT approaches the average falling voltage VF AVE , the zero-rate increases as more of the cases of voltage fall become less than threshold level VT. A third plateau rate 430 occurs when nearly all samples of the falling voltage at the selected phase are less than the threshold level VT. This plateau rate 430 would be about 75% for a signal representing a binary series in which the probability to remain at the same level is equal to the probability to transition to the other level, but plateau rate 430 may differ if the signal has different statistical properties.
[0033] The zero-rate rises again when the threshold level VT exceeds the minimum voltage V 1 MIN representing binary value 1. A final plateau rate 440 of 100% occurs when the threshold level VT is greater than the maximum voltage V 1 MAX of signal DT.
[0034] Varying the selected phase and repeating the measurements of the rates for each of a series of threshold levels VT provides the zero-rate as a function of a two-dimensional domain. FIG. 5 illustrates how the domain of threshold level VT and phase Φ can be divided into regions 510 , 520 , 530 , 540 , and 550 . Region 510 corresponds to a zero-rate that is nearly zero because the threshold voltage VT is below the minimum voltage of the signal. Region 520 corresponds to a first plateau rate where threshold level VT is greater than nearly all of the cases where the sample corresponds to a stable low level of the signal. Region 530 corresponds to a second plateau rate where threshold level VT is greater than one of the average transitional voltages of the signal. Region 540 corresponds to a third plateau rate where threshold level VT is greater than both of the average transitional voltages of the signal. Region 550 corresponds to the final plateau where threshold level VT is greater than maximum voltage of the signal. Regions 515 , 525 , 535 , and 545 are regions where the rate is transitioning from one plateau to another.
[0035] Processing of the data represented in FIG. 5 can provide a result comparable to an oscilloscope measurement. For example, if at a given sampling phase, a zero-rate of 50% is observed at a threshold V 1 and a zero-rate of 51% is observed at a threshold V 2 that is greater than threshold V 1 , then 1% of the sampled signal waveforms must have had voltages between V 1 and V 2 at the sampling time/phase. More generally, the density of traces per voltage of the signal, which is what an oscilloscope measures, is equal to the derivative of the zero-rate with respect to sampling threshold. Given a set of zero-rates that a binary sampler produced at various choices of parameters Φ and VT, well-known numerical techniques can approximate the derivative. In particular, finite differences in the rates provide a simple approximation of the derivative. Numerical derivatives are inherently noisy, and thus long sampling times may be preferred to obtain high accuracy in estimating the trace density.
[0036] FIG. 6 illustrates areas 610 of the domain of threshold level VT and phase Φ where the derivative of the rate function is above a minimal non-zero level. Areas 610 correspond to oscilloscope traces. In particular, areas 610 form the “eye” pattern that oscilloscopes traces conventionally form during analysis a binary signal. The eye pattern presents analog characteristics of the signal such as the minimum and maximum voltage level representing zero, the minimum and maximum voltage levels representing one, the rising edge duration, the falling edge duration, and the general time dependence of the rise and fall of voltage levels. (Rising and falling edge durations are signal parameters representing the time required for transitions between binary zero and one levels.) Given the trace density eye, such as that shown in FIG. 6 , the rise and fall times can be measured using techniques developed for oscilloscope analysis. Further refinements to the analysis techniques, which reduce the amount of sample data required, are described further below.
[0037] The measurement results illustrated in FIG. 6 depend only on the derivative or gradient of the zero-rates (or the one-rates), and no knowledge of the incoming pattern or binary series is required. Thus, the technique may be applied to operational systems. Further, a system measuring analog signal characteristics through evaluation of the zero-rate (or one-rate) of a binary sampled signal can employ circuitry that is simpler than a BER tester. For example, a system such as system 200 of FIG. 2 that can measure zero-rates (or one-rates) does not require the error comparator and local pattern generator used in the bit error measurement systems such as system 100 of FIG. 1 .
[0038] An advantage of using zero-rates or one-rates for signal analysis is the ability to determine voltages Vtop and Vbase, which represent the average voltages of respective binary values one and zero. Oscilloscopes commonly provide built-in measurements of voltages Vtop and Vbase, but such measurements may be impractical when using BER testers due to the synchronization requirements between the sampled signal and the known pattern. Using zero-counting or one-counting, voltages Vtop and Vbase can be measured by choosing a sampling phase at the eye center of traces 610 and locating the threshold level VT giving 75% and 25% zero-rate, respectively. It should be noted that the analysis that determines voltages Vtop and Vbase does not require determination of a derivative or the trace density.
[0039] The 20%-80% rising edge duration can be determined using voltages Vtop and Vbase that are determined as described above. A process for determining the 20%-80% rising edge duration, for example, can initially set threshold level VT to 0.8*Vbase+0.2*Vtop, and then search for a phase Φ to the right of the eye center that gives a zero-rate equal to ½ of the plateau rate 410 . Subtracting the bit period from this phase Φ provides the initial instant tr 1 of the rising edge. The process can then set threshold level VT to 0.2*Vbase+0.8*Vtop and search for a phase Φ to the left of eye center that achieves a zero-rate equal to the average of plateau rate 430 and plateau rate 440 . This identifies the final instant tr 2 of the rising edge. The rising edge duration is the difference tr 2 −tr 1 . Other VT values might be used, for example to find the 10%-90% rising edge duration. It is also straightforward to modify the described process to find similar falling edge durations. The method of searching for the correct zero-rate could be by any of several well-known search algorithms. The use of search algorithms, and direct analysis of the zero-rate without calculating derivatives, reduces the number of combinations of phase Φ and threshold level VT that must be sampled to reach the desired measurement result.
[0040] Another measurable analog signal characteristic is overshoot or undershoot. Overshoot and undershoot are signal parameters that indicate the amount of ringing present in a waveform. Because ringing phenomena are characterized by waveform behavior outside the central eye area, measurement overshoot and undershoot by BER techniques may not be practical, but zero or one counting techniques can measure these parameters. For example, to measure overshoot, the system can measure Vtop at various phases Φ. The number of different phases measured can be selected according to the bandwidth of the signal DT. The maximum Vtop, divided by Vtop at the center phase, is the overshoot.
[0041] Mask testing is a further use of both oscilloscopes and BER testers. Mask testing requires detection of signal traces passing through forbidden regions of the eye. BER testers generally are able to test only masks within the central eye region. The masks specified for important communications standards such as Gigabit Ethernet and Fibre Channel also specify mask regions above and below the eye. Testing against these masks is commonly done with an oscilloscope. However, zero or one counting allows testing mask regions inside and outside the central eye area using low cost binary sampling circuits. A system having a zero or one-counter can test above or below the central eye simply by setting parameters VT and Φ to correspond to points in the mask region above (or below) the eye, and count occurrences of ones (or zeroes), which indicate mask failures.
[0042] Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. For example, although the above-described embodiments have concentrated on analysis of binary data signals, similar techniques and circuit can analyze other signals such as clock signal, a return-to-zero encoded data signal, or a multilevel-encoded data signal. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as defined by the following claims.
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Circuits that count zeros or ones in a binary sampling of a signal can measure analog characteristics of the signal. By this technique, relatively simple circuits can perform parameter measurements that are difficult to achieve with BER-based binary sampling techniques. Low cost binary sampling circuits can also perform measurements that previously might have required more complex and expensive analog sampling. The new technique is applicable to full-featured test systems, low-cost test circuits, and on-chip test circuits.
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RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/642,841 filed on Jan. 10, 2005, which is incorporated herein by reference in its entirety.
FIELD
The present invention relates to the fields of chemistry and medicine. More particularly, the present invention relates to novel compounds and methods of using those compounds for medicinal use and/or to modulate androgen receptors.
BACKGROUND
The discussion that follows is intended solely as background information to assist in the understanding of this invention; nothing in this section is intended to be, nor is it to be construed as, prior art to the invention.
The androgen receptor (AR) belongs to the family of nuclear hormone receptors. Nuclear hormone receptors define a superfamily of ligand activated transcription factors. Members of this family are characterized by a number of modular domains: a zinc finger DNA binding domain (DBD), which triggers the interaction of the receptor with specific response elements at the DNA site, a ligand binding domain (LBD) adjacent to the DBD, and two transcriptional activation domains AF-1 and AF-2, which are ligand-independent and ligand-dependent, respectively. Upon ligand binding to the receptor, a conformational change occurs within the LBD bringing the AF-2 domain in closer proximity and allowing for the recruitment of co-activators. Co-activators create a physical interaction between the nuclear hormone receptor and components of the transcriptional machinery, establishing transcriptional modulation of target genes.
The steroid sex hormones testosterone and the more potent dihydroxy testosterone (DHT) represent the AR endogenous ligands. Through activation of the receptor, these “male sex hormones” modulate a number of physiological processes most notably primary and secondary male characteristics.
Clinical situations in which levels of plasma testosterone are decreased, also known as hypogonadism, have been extensively studied. For instance, children suffering from such a condition exhibit a total absence of pubertal development. Delay in puberty leads to psychological problems, secondary to short stature and/or delay in the acquisition of secondary sexual characteristics and the reduction of bone mass. Moreover, several epidemiological studies have confirmed that plasma testosterone levels gradually decrease with aging. On average a quarter of men in their sixties display clinical hypogonadism. This condition is even more prevalent among male octogenarians where 50-80% of men in this age group clinically qualify for hypogonadism. Decreased testosterone plasma levels are also seen in aging women. Age-related hypogonadism is associated with an obvious impairment in the quality of life from physical manifestations (muscle, bone density loss) to psychological problems (mood disorders, cognition, decreased libido). This condition is referred to as “male menopause” or “andropause”.
Current therapies rely on the use of testosterone and testosterone analogs. They are the treatment of choice in delayed male puberty, male fertility as well as endometriosis. Because of the strong anabolic effects of this class of steroid hormones, they have been therapeutically approved for restoring skeletal muscle mass in patients suffering from burns. A number of placebo controlled clinical studies have reported a therapeutic benefit to androgen agonism in aging men. In particular, reports have emerged demonstrating the benefit of testosterone replacement therapy in improving a number of aspects of age related hypogonadism such as bone density, anabolism, libido, mood disorders (lack of vigor, well being) and cognition. In the ophthalmologic arena, dry eye is also amenable to treatment with testosterone or testosterone analogs. More recent studies have highlighted a correlation between decreasing testosterone levels and increased incidence of Alzheimer's disease.
Since oral preparations of testosterone and testosterone analogs are ineffective due to enhanced first-pass metabolism and hepatotoxicity, intramuscular injectable forms of long-acting esters have constituted the basis of testosterone replacement therapy. However, the large fluctuations of serum testosterone levels induced by these preparations cause unsatisfactory shifts of mood and sexual function in some men; because of the frequent injections required, this delivery mode is thus far from being ideal. In contrast, transdermal testosterone patches display more favorable pharmacokinetic properties and have proven to be an effective mode of delivery. Nevertheless, testosterone patch systems (especially scrotal patches) are hampered by the high rate of skin irritations. Recently, testosterone gels have gained approval. Gels are applied once daily on the skin in quantities large enough to deliver sufficient amounts of testosterone to restore normal hormonal values and correct the signs and symptoms of hypogonadism. However while being very effective, this mode of application raises matters of adequate and consistent delivery.
Steroidal AR ligands, however, are plagued by undesirable adverse side effects, for instance prostate enlargement, acne, hirsutism, virilization and masculinisation. Furthermore, the androgenic property of testosterone and its analogs are thought to constitute a enhanced risk of prostate cancer. Thus, a search has been initiated for non-steroidal compounds that can modulate the activity of AR ligands; such compounds are referred to as Selective Androgen Receptor Modulators or SARMs. It is expected that this class of compounds will in general demonstrate better pharmacokinetic and specificity profiles than current steroidal therapies. In particular, non-steroidal SARMs are expected to lack androgenic properties. Second generation SARMs are expected contribute additional therapeutic benefits by displaying positive anabolic properties and antagonistic androgenic components. Another desirable feature of SARMs is expected to be their significant bioavailability.
SUMMARY
An embodiment of this invention is a compound represented by formula (I) or formula (II):
and prodrugs, stereoisomers, and pharmaceutically acceptable salts thereof wherein:
Z 1 , Z 2 , Z 3 and Z 4 are each independently selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted heterocyclyl, halogen, cyano, hydroxy, optionally substituted aminoalkyl, optionally substituted alkoxy, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclylalkyl, optionally substituted heteroarylalkyl, C(O)OR 4 , C(O)NR 4 R 5 , NHC(O)R 4 , NHSO 2 R 4 , OC(O)R 4 , C═NOR 4 , CF 3 , COR 4 , SR 4 , S(O) n R 8 , and SO 2 NR 8 R 9 ; provided that at least one of Z 1 , Z 2 , Z 3 or Z 4 is not hydrogen; R 1 is selected from the group consisting of cyano and nitro; ring A, which comprises atoms Y 1 and Y 2 , is an optionally substituted bicyclic or tricyclic non-aromatic heterocycle containing up to three heteroatoms selected from the group consisting of N, O, S, S═O, SO 2 , C═O, and C═S, wherein neither Y 1 nor Y 2 is C═O or C═S; R 4 and R 5 are each independently selected from the group consisting of hydrogen, cyano, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, heterocyclylalkyl or substituted heterocyclylalkyl, arylalkyl or substituted arylalkyl, aryl or substituted aryl, heteroarylalkyl or substituted heteroarylalkyl, and heteroaryl or substituted heteroaryl; R 6 and R 7 are each independently selected from the group consisting of hydrogen, halo, cyano, hydroxy, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, heterocyclylalkyl or substituted heterocyclylalkyl, arylalkyl or substituted arylalkyl, aryl or substituted aryl, heteroarylalkyl or substituted heteroarylalkyl, heteroaryl or substituted heteroaryl, OR 4 , NR 4 R 5 , SR 4 , C(O)R 4 , C(O)OR 4 , C(O)NR 4 R 5 , NHC(O)R 4 , NR 4 C(O)R 5 , OC(O)R 4 , C(S)R 4 , C(S)OR 4 , C(S)NR 4 R 5 , NHC(S)R 4 , OC(S)R 4 , S(O) n R 4 , SO 2 NR 4 R 5 , OSO 2 R 4 , NHSO 2 R 4 , and alkyl substituted with OR 4 , NR 4 R 5 , SR 4 , C(O)R 4 , C(O)OR 4 , C(O)NR 4 R 5 , NHC(O)R 4 , NR 4 C(O)R 5 , OC(O)R 4 , C(S)R 4 , C(S)OR 4 , C(S)NR 4 R 5 , NHC(S)R 4 , OC(S)R 4 , S(O)R 4 , SO 2 NR 4 R 5 , OSO 2 R 4 , or NHSO 2 R 4 ; R 8 and R 9 are each independently selected from the group consisting of hydrogen, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, heterocyclylalkyl or substituted heterocyclylalkyl, arylalkyl or substituted arylalkyl, and heteroarylalkyl or substituted heteroarylalkyl; and n is an integer from 1 to 3.
In an embodiment of this invention, the compound of formula I or formula II is not selected from the group consisting of:
In an embodiment of this invention, ring A is a bicyclic heterocycle.
In an embodiment of this invention, the bicyclic heterocycle is a bridged bicyclic heterocycle.
In an embodiment of this invention:
Z 1 and Z 2 are independently selected from the group consisting of hydrogen, unsubstituted —(C 1 -C 4 )alkyl, —(C 1 -C 4 )alkylOH, —(C 1 -C 4 )alkyl(halo), halo, cyano, —OR 4 , —OC(O)R 4 , —CF 3 , —CHO and —CH═NOR 4 ; R 6 and R 7 are independently selected from the group consisting of hydrogen, unsubstituted —(C 1 -C 4 )alkyl, —(C 1 -C 4 )alkylOH, —(C 1 -C 4 )alkyl(halo), halo, cyano, —OR 4 , —OC(O)R 4 and —CF 3 ; and,
the bridged bicyclic heterocycle comprises one nitrogen atom, wherein R 4 is selected from the group consisting of hydrogen, unsubstituted (C 1 -C 4 )alkyl, unsubstituted (C 3 -C 6 )cycloalkyl and unsubstituted aryl.
In an embodiment of this invention ring A has the structure:
In an embodiment of this invention ring A has the structure:
In an embodiment of this invention, R 6 is hydroxy.
In an embodiment of this invention, R 7 is —(C 1 -C 4 )alkyl.
In an embodiment of this invention, R 7 is bonded to the same carbon atom to which R 6 is bonded.
In an embodiment of this invention, ring A is tropane or an optionally substituted tropane. In an embodiment of this invention, ring A is optionally substituted with one or more substituents selected from the group consisting of hydrogen, halogen, hydroxy, alkoxy or substituted alkoxy, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, aminoalkyl or substituted aminoalkyl, OC(O)R 4 , and NHC(O)R 4 . In an embodiment of this invention, R 1 is cyano. In an embodiment of this invention, at least one of R 6 or R 7 on ring A is hydroxy or alkyl. In an embodiment of this invention, Z 1 is alkyl, halogen, haloalkyl or hydroxyalkyl. In an embodiment of this invention, Z 2 is alkyl, halogen, haloalkyl or hydroxyalkyl. In an embodiment of this invention, Z 1 is methyl or ethyl and Z 2 is halogen. In an embodiment of this invention, Z 1 is methyl or ethyl and Z 2 is chloro. In an embodiment of this invention, Z 1 is methyl and Z 2 is chloro.
In an embodiment of this invention, the compound of formula (I) or formula (II) is selected from the group consisting of:
endo-8-(3-chloro-2-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; 2-Chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]octan-8-yl)-3-methylbenzonitrile; 2-Bromo-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-5-methylbenzonitrile; 6-(3-endo-Hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-2-methyl-3-nitrobenzoic acid; 2-(Trifluoromethyl)-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]octan-8-yl)benzonitrile 3-Bromo-2-chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1 ]oct-8-yl)benzonitrile; endo-8-(2,3-Dimethyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; 2-Chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-iodobenzonitrile; endo-8-[2-(hydroxymethyl)-3-methyl-4-nitrophenyl]-8-azabicyclo[3.2.1]octan-3-ol; 4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-trifluoromethylbenzonitrile; endo-8-(2-Chloro-3-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; 2-Chloro-6-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-nitrobenzaldehyde; endo-8-(3-Chloro-2-hydroxymethyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; 2-Chloro-6-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-nitrobenzaldehyde oxime; endo-8-(2-Chloro-3-hydroxymethyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; endo-8-(5-Chloro-2-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; 2-Chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)benzonitrile; 6-(3-endo-Hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-2-methyl-3-nitrobenzoic acid; endo-8-(2-Hydroxymethyl-3-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol; 2-Chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile; 2-Chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile hydrochloride; and 2-Chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile mesylate.
An embodiment of this invention is a prodrug ester, carbonate, carbamate, sulfate, phosphate or phosphoramidate of a compound or formula (I) or formula (II).
An embodiment disclosed herein includes a pharmaceutical composition comprising a compound of formula (I) or formula (II) and a pharmaceutically acceptable excipient.
An embodiment disclosed herein includes a method of treating a condition selected from the group consisting of hypogonadism, lower than normal testosterone plasma levels, infertility in males, erectile dysfunction in males, andropause in males, endometriosis in females, dyspareunia in females, vaginismus in females, sexual arousal disorders in females, sexual orgasmic disorders in females, disorders of libido in males, cachexia, HIV wasting, critical illnesses in which muscle wasting is apparent, sarcopenia, frailty, short stature, dwarfism, bone density loss, mood disorders, depression, impaired cognitive functions, neurodegenerative disorders, xerophthalmia, metabolic disorders, cardiovascular disorders, obesity, anemia, prostate cancer, and schizophrenia, comprising administering to a patient exhibiting one or more symptoms of the condition a compound of a compound of this invention or a prodrug, stereoisomer, or pharmaceutically acceptable salt thereof.
In an embodiment of this invention, the mood disorder is selected from the group consisting of lack of well being, lack of vigor, anger, irritability, sadness, tiredness, and nervousness. In an embodiment of this invention, the neurodegenerative disorder is selected from the group consisting of Alzheimer's disease, Mild cognition impairment (MCI), Lewis body dementia, and frontal temporal dementia. In an embodiment of this invention, the metabolic disorder is selected from the group consisting of dyslipidemia, atherosclerosis, and non-insulin dependent diabetes (NIDDM). In an embodiment of this invention, the cardiovascular disorder is selected from the group consisting of hypertension, coronary artery disease, and myocardial perfusion.
An embodiment of this invention is a method of modulating spermatogenesis in males, comprising: administering to a male subject a compound of this invention or a prodrug, a stereoisomer or a pharmaceutically acceptable salt thereof.
An embodiment disclosed herein is a method of hormonal replacement therapy, comprising administering to a subject in need of hormonal replacement therapy a compound of this invention or a prodrug, a stereoisomer or a pharmaceutically acceptable salt thereof.
An embodiment of this invention, need for hormonal replacement therapy is caused by orchiectomy by surgical or chemical means.
An embodiment disclosed herein includes a method of improving muscle strength comprising administering to a subject in need thereof a compound of this invention or a prodrug, a stereoisomer or a pharmaceutically acceptable salt thereof.
In an embodiment of this invention, need for improvement in muscular strength is caused by muscular dystrophy, myotonic dystrophy, or glucocorticoid-treated asthma.
An embodiment disclosed herein includes a method of preventing a condition selected from the group consisting of bone density loss, xerophthalmia, metabolic disorders, cardiovascular disorders, obesity, and prostate cancer, comprising administering to a subject a compound of this invention or a prodrug, a stereoisomer or a pharmaceutically acceptable salt thereof.
In an embodiment of this invention, the metabolic disorder is selected from the group consisting of dyslipidemia, atherosclerosis, and non-insulin dependent diabetes (NIDDM). In one embodiment, the cardiovascular disorder is selected from the group consisting of hypertension, coronary artery disease, and myocardial perfusion.
An embodiment disclosed herein includes a method of improving a health-related quality of life parameter selected from the group consisting of survival, impairment, functional status, health perception, and opportunities, comprising administering to a subject a compound of this invention or a prodrug, a stereoisomer or a pharmaceutically acceptable salt thereof.
An embodiment disclosed herein includes a method of delaying the progression of prostate cancer, comprising administering to a patient in need thereof a compound of this invention or a prodrug, a stereoisomer, or a pharmaceutically acceptable salt thereof.
An embodiment disclosed herein includes a method of modulating an androgen receptor comprising contacting the receptor with a compound of this invention or a prodrug, a stereoisomer or a pharmaceutically acceptable salt thereof.
DETAILED DESCRIPTION
Brief Description of the Drawings
FIG. 1 depicts bar graphs comparing wet tissue weights of prostate tissues upon daily subcutaneous (s.c.) administration to rats of 1 or 3 mg/kg of testosterone propionate (TP) with various doses of compound 198RL26 (p.o.) for a period of two weeks.
FIG. 2 depicts bar graphs comparing wet tissue weights of seminal vesicle tissues upon daily s.c. administration to rats of 1 or 3 mg/kg of testosterone propionate (TP) with various doses of compound 198RL26 (p.o.) for a period of two weeks.
FIG. 3 depicts bar graphs comparing wet tissue weights of levator ani muscle tissues upon daily s.c. administration to rats of 1 or 3 mg/kg of testosterone propionate (TP) with various doses of compound 198RL26 (p.o.) for a period of two weeks.
FIG. 4 depicts bar graphs of plasma levels of luteinizing hormone (LH) in rats upon castration after daily (s.c.) administration to rats of 1 or 3 mg/kg of testosterone propionate (TP) with various doses of compound 198RL26 (p.o.) for a period of two weeks.
Discussion
As noted above, in an embodiment of this invention, prodrugs, metabolites, stereoisomers, and pharmaceutically acceptable salts of the compounds of this invention are provided.
A “prodrug” refers to an agent that is converted into the parent drug in vivo. Prodrugs are often useful because, in some situations, they may be easier to administer than the parent drug. They may, for instance, be bioavailable by oral administration whereas the parent is not. The prodrug may also have improved solubility in pharmaceutical compositions over the parent drug. Conventional procedures for the selection and preparation of suitable prodrug derivatives are described, for example, in Design of Prodrugs , (ed. H. Bundgaard, Elsevier, 1985), which is hereby incorporated herein by reference in its entirety. A non-limiting example of a prodrug for use herein includes those that promote the solubility of alcohols such as by the procedures described in Mahfous, N. H. et al, J. Pharm. Pharmacol., 53, 841-848 (2001) and Bundgaard, H. et al., J. Med. Chem., 32, 2503-2507 (1989), both of which are incorporated herein by reference in their entirety.
The term “pro-drug ester” refers to derivatives of the compounds disclosed herein formed by the addition of any of several ester-forming groups that are hydrolyzed under physiological conditions. Examples of pro-drug ester groups include pivoyloxymethyl, acetoxymethyl, phthalidyl, indanyl and methoxymethyl, as well as other such groups known in the art, including a (5-R-2-oxo-1,3-dioxolen-4-yl)methyl group. Other examples of pro-drug ester groups can be found in, for example, T. Higuchi and V. Stella, in “Pro-drugs as Novel Delivery Systems”, Vol. 14, A.C.S. Symposium Series, American Chemical Society (1975); and “Bioreversible Carriers in Drug Design: Theory and Application”, edited by E. B. Roche, Pergamon Press: New York, 14-21 (1987) (providing examples of esters useful as prodrugs for compounds containing carboxyl groups). Each of the above-mentioned references is herein incorporated by reference in their entirety.
Metabolites of the compounds of this invention include active species that are produced upon introduction of the compounds into the biological milieu.
Where the compounds of formula (I) or formula (II) have at least one chiral center, they may exist as a racemate or as enantiomers. It should be noted that all such isomers and mixtures thereof are included in the scope of the present invention. Furthermore, some of the crystalline forms for the compounds of formula (I) or formula (II) may exist as polymorphs. Such polymorphs are included in one embodiment of the present invention. In addition, some of the compounds of the present invention may form solvates with water (i.e., hydrates) or common organic solvents. Such solvates are included in one embodiment of the present invention.
The term “pharmaceutically acceptable salt” refers to a salt of a compound that does not cause significant irritation to an organism to which it is administered and does not abrogate the biological activity and properties of the compound. In some embodiments, the salt is an acid addition salt of the compound. Pharmaceutical salts can be obtained by reacting a compound with inorganic acids such as hydrohalic acid (e.g., hydrochloric acid or hydrobromic acid), sulfuric acid, nitric acid, phosphoric acid and the like. Pharmaceutical salts can also be obtained by reacting a compound with an organic acid such as aliphatic or aromatic carboxylic or sulfonic acids, for example acetic, succinic, lactic, malic, tartaric, citric, ascorbic, nicotinic, methanesulfonic, ethanesulfonic, p-toluensulfonic, salicylic or naphthalenesulfonic acid. Pharmaceutical salts can also be obtained by reacting a compound with a base to form a salt such as an ammonium salt, an alkali metal salt, such as a sodium or a potassium salt, an alkaline earth metal salt, such as a calcium or a magnesium salt, a salt of organic bases such as dicyclohexylamine, N-methyl-D-glucamine, tris(hydroxymethyl)methylamine, C 1 -C 7 alkylamine, cyclohexylamine, triethanolamine, ethylenediamine, and salts with amino acids such as arginine, lysine, and the like.
If the manufacture of pharmaceutical formulations involves intimate mixing of the pharmaceutical excipients and the active ingredient in its salt form, then it may be desirable to use pharmaceutical excipients which are non-basic, that is, either acidic or neutral excipients.
In an embodiment of this invention, the compounds of this invention can be used alone, in combination with other compounds hereof or in combination with one or more other agents active in the therapeutic areas described herein.
The term “halogen atom,” refers to fluorine, chlorine, bromine, or iodine, with fluorine and chlorine being presently preferred.
The term “ester” refers to a chemical moiety with formula —(R) n —COOR′, where R and R′ are independently selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl (bonded through a ring carbon) and heteroalicyclic (bonded through a ring carbon), and where n is 0 or 1.
An “amide” is a chemical moiety with formula —(R) n —C(O)NHR′ or —(R) n —NHC(O)R′, where R and R′ are independently selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl (bonded through a ring carbon) and heteroalicyclic (bonded through a ring carbon), and where n is 0 or 1. An amide may be an amino acid or a peptide molecule attached to a compound of this invention, thereby forming a prodrug.
Any amine, hydroxy, or carboxyl side chain on the compounds of the present invention can be esterified or amidified. The procedures and specific groups to be used to achieve this end are known to those of skill in the art and can readily be found in reference sources such as Greene and Wuts, Protective Groups in Organic Synthesis, 3 rd Ed., John Wiley & Sons, New York, N.Y., 1999, which is incorporated herein in its entirety.
The term “aromatic” refers to an aromatic group which has at least one ring having a conjugated pi electron system and includes both carbocyclic aryl (e.g., phenyl) and heterocyclic aryl groups (e.g., pyridine). The term includes monocyclic or fused-ring polycyclic (i.e., rings which share adjacent pairs of carbon atoms) groups. The term “carbocyclic” refers to a compound which contains one or more covalently closed ring structures, and that the atoms forming the backbone of the ring are all carbon atoms. The term thus distinguishes carbocyclic from heterocyclic rings in which the ring backbone contains at least one atom which is different from carbon. The term “heteroaromatic” refers to an aromatic group which contains at least one heterocyclic ring.
The term “alkyl,” as used herein, means any unbranched or branched, substituted or unsubstituted, saturated hydrocarbon. The alkyl moiety, may be branched, straight chain, or cyclic. The alkyl group may have 1 to 20 carbon atoms (whenever it appears herein, a numerical range such as “1 to 20” refers to each integer in the given range; e.g., “1 to 20 carbon atoms” means that the alkyl group may consist of 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms, although the present definition also covers the occurrence of the term “alkyl” where no numerical range is designated). The alkyl group may also be a medium size alkyl having 1 to 10 carbon atoms. The alkyl group could also be a lower alkyl having 1 to 5 carbon atoms. The alkyl group may be designated as “C 1 -C 4 alkyl” or similar designations. By way of example only, “C 1 -C 4 alkyl” indicates that there are one to four carbon atoms in the alkyl chain, i.e., the alkyl chain is selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and t-butyl.
The alkyl group may be substituted or unsubstituted. When substituted, the substituent group(s) is(are) one or more group(s) individually and independently selected from substituted or unsubstituted cycloalkyl, substituted or unsubstituted cylcloalkenyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroaryloxy, heterocyclyl, heterocyclooxy, heteroalicyclyl, hydroxy, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, acyl, thiol, substituted or unsubstituted thioalkoxy, alkylthio, arylthio, cyano, halo, carbonyl, thiocarbonyl, acylalkyl, acylamino, acyloxy, aminoacyl, aminoacyloxy, oxyacylamino, keto, thioketo, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulfonamido, N-sulfonamido, C-carboxy, O-carboxy, isocyanato, thiocyanato, isothiocyanato, nitro, silyl, trihalomethanesulfonyl, and substituted or unsubstituted amino, including mono- and di-substituted amino groups, and the protected derivatives thereof, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO 2 -alkyl, —SO 2 -substituted alkyl, —SO 2 -aryl and —SO 2 -heteroaryl. Typical alkyl groups include, but are in no way limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, ethenyl, propenyl, butenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. Wherever a substituent is described as being “optionally substituted” that substitutent may be substituted with one of the above substituents.
In the present context, the term “cycloalkyl” is intended to cover three-, four-, five-, six-, seven-, and eight- or more membered rings comprising carbon atoms only. A cycloalkyl can optionally contain one or more unsaturated bonds situated in such a way, however, that an aromatic pi-electron system does not arise. Some examples of “cycloalkyl” are the carbocycles cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, cycloheptane, or cycloheptene.
An “alkenyl” moiety refers to a group consisting of at least two carbon atoms and at least one carbon-carbon double bond. An alkenyl may be unbranched or branched, substituted or unsubstituted, unsaturated hydrocarbon including polyunsaturated hydrocarbons. In some embodiments, the alkenyl is a C 1 -C 6 unbranched, mono-unsaturated or di-unsaturated, unsubstituted hydrocarbons. The term “cycloalkenyl” refers to any non-aromatic hydrocarbon ring, preferably having five to twelve atoms comprising the ring.
An “alkyne” moiety refers to a group consisting of at least two carbon atoms and at least one carbon-carbon triple bond.
The substituent “R” appearing by itself and without a number designation refers to a substituent selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl (bonded through a ring carbon) and heteroalicyclyl (bonded through a ring carbon).
The term “alkoxy” refers to any unbranched, or branched, substituted or unsubstituted, saturated or unsaturated ether, with C 1 -C 6 unbranched, saturated, unsubstituted ethers being preferred, with methoxy being preferred, and also with dimethyl, diethyl, methyl-isobutyl, and methyl-tert-butyl ethers also being preferred. The term “cycloalkoxy” refers to any non-aromatic hydrocarbon ring, preferably having five to twelve atoms comprising the ring.
An “O-carboxy” group refers to a RC(═O)O— group, where R is as defined herein.
A “C-carboxy” group refers to a —C(═O)OR groups where R is as defined herein.
An “acetyl” group refers to a —C(═O)CH 3 , group.
A “trihalomethanesulfonyl” group refers to a X 3 CS(═O) 2 — group where X is a halogen.
A “cyano” group refers to a —CN group.
An “isocyanato” group refers to a —NCO group.
A “thiocyanato” group refers to a —CNS group.
An “isothiocyanato” group refers to a —NCS group.
A “sulfinyl” group refers to a —S(═O)—R group, with R as defined herein.
A “S-sulfonamido” group refers to a —S(═O) 2 NR, group, with R as defined herein.
A “N-sulfonamido” group refers to a RS(═O) 2 NH— group with R as defined herein.
A “trihalomethanesulfonamido” group refers to a X 3 CS(═O) 2 NR— group with X and R as defined herein.
An “O-carbamyl” group refers to a —OC(═O)—NR, group-with R as defined herein.
An “N-carbamyl” group refers to a ROC(═O)NH— group, with R as defined herein.
An “O-thiocarbamyl” group refers to a —OC(═S)—NR, group with R as defined herein.
An “N-thiocarbamyl” group refers to an ROC(═S)NH— group, with R as defined herein.
A “C-amido” group refers to a —C(═O)—NR 2 group with R as defined herein.
An “N-amido” group refers to a RC(═O)NH— group, with R as defined herein.
The term “perhaloalkyl” refers to an alkyl group where all of the hydrogen atoms are replaced by halogen atoms.
The term “acylalkyl” refers to a RC(═O)R′— group, with R as defined herein, and R′ being a diradical alkylene group. Examples of acylalkyl, without limitation, may include CH 3 C(═O)CH 2 —, CH 3 C(═O)CH 2 CH 2 —, CH 3 CH 2 C(═O)CH 2 CH 2 —, CH 3 C(═O)CH 2 CH 2 CH 2 —, and the like.
The term “aminoalkyl” refers to a substituent selected from the group consisting of —RNR′R″, —RNHR′, and —RNH 2 , with R, R′, and R″ independently being as R is defined herein.
Unless otherwise indicated, when a substituent is deemed to be “optionally substituted,” it is meant that the substituent is a group that may be substituted with one or more group(s) individually and independently selected from morpholinoalkanoate, cycloalkyl, aryl, heteroaryl, heterocyclyl, heteroalicyclic, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, thiocarbonyl, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulfonamido, N-sulfonamido, C-carboxy, O-carboxy, isocyanato, thiocyanato, isothiocyanato, nitro, silyl, trihalomethanesulfonyl, and amino, including mono- and di-substituted amino groups, and the protected derivatives thereof. The protecting groups that may form the protective derivatives of the above substituents are known to those of skill in the art and may be found in references such as Greene and Wuts, above.
The term “heterocyclyl” is intended to mean three-, four-, five-, six-, seven-, and eight- or more membered rings wherein carbon atoms together with from 1 to 3 heteroatoms constitute the ring. A heterocyclyl can optionally contain one or more unsaturated bonds situated in such a way, however, that an aromatic pi-electron system does not arise. The heteroatoms are independently selected from oxygen, sulfur, and nitrogen.
A heterocyclyl can further contain one or more carbonyl or thiocarbonyl functionalities, so as to make the definition include oxo-systems and thio-systems such as lactams, lactones, cyclic imides, cyclic thioimides, cyclic carbamates, and the like.
Heterocyclyl rings can optionally be fused ring systems containing two or more rings wherein at least one atom is shared between two or more rings to form bicyclic or tricyclic structures. In some embodiments, such fused ring systems are formed by a bridging moiety between two atoms of a heterocyclyl.
Heterocyclyl rings can optionally also be fused to aryl rings, such that the definition includes bicyclic structures. Typically such fused heterocyclyl groups share one bond with an optionally substituted benzene ring. Examples of benzo-fused heterocyclyl groups include, but are not limited to, benzimidazolidinone, tetrahydroquinoline, and methylenedioxybenzene ring structures.
Some examples of “heterocyclyls” include, but are not limited to, tetrahydrothiopyran, 4H-pyran, tetrahydropyran, piperidine, 1,3-dioxin, 1,3-dioxane, 1,4-dioxin, 1,4-dioxane, piperazine, 1,3-oxathiane, 1,4-oxathiin, 1,4-oxathiane, tetrahydro-1,4-thiazine, 2H-1,2-oxazine, maleimide, succinimide, barbituric acid, thiobarbituric acid, dioxopiperazine, hydantoin, dihydrouracil, morpholine, trioxane, hexahydro-1,3,5-triazine, tetrahydrothiophene, tetrahydrofuran, pyrroline, pyrrolidine, pyrrolidone, pyrrolidione, pyrazoline, pyrazolidine, imidazoline, imidazolidine, 1,3-dioxole, 1,3-dioxolane, 1,3-dithiole, 1,3-dithiolane, isoxazoline, isoxazolidine, oxazoline, oxazolidine, oxazolidinone, thiazoline, thiazolidine, 1,3-oxathiolane, and an azabicyclo system such as azabicyclo[3.2.1]octyl(tropane). Binding to the heterocycle can be at the position of a heteroatom or via a carbon atom of the heterocycle, or, for benzo-fused derivatives, via a carbon of the benzenoid ring.
In the present context the term “aryl” is intended to mean a carbocyclic aromatic ring or ring system. Moreover, the term “aryl” includes fused ring systems wherein at least two aryl rings, or at least one aryl and at least one C 3-8 -cycloalkyl share at least one chemical bond. Some examples of “aryl” rings include optionally substituted phenyl, naphthalenyl, phenanthrenyl, anthracenyl, tetralinyl, fluorenyl, indenyl, and indanyl. The term “aryl” relates to aromatic, including, for example, benzenoid groups, connected via one of the ring-forming carbon atoms, and optionally carrying one or more substituents selected from heterocyclyl, heteroaryl, halo, hydroxy, amino, cyano, nitro, alkylamido, acyl, C 1-6 alkoxy, C 1-6 alkyl, C 1-6 hydroxyalkyl, C 1-6 aminoalkyl, C 1-6 alkylamino, alkylsulfenyl, alkylsulfinyl, alkylsulfonyl, sulfamoyl, or trifluoromethyl. The aryl group can be substituted at the para and/or meta positions. In other embodiments, the aryl group can be substituted at the ortho position. Representative examples of aryl groups include, but are not limited to, phenyl, 3-halophenyl, 4-halophenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 3-aminophenyl, 4-aminophenyl, 3-methylphenyl, 4-methylphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-trifluoromethoxyphenyl 3-cyanophenyl, 4-cyanophenyl, dimethylphenyl, naphthyl, hydroxynaphthyl, hydroxymethylphenyl, trifluoromethylphenyl, alkoxyphenyl, 4-morpholin-4-ylphenyl, 4-pyrrolidin-1-ylphenyl, 4-pyrazolylphenyl, 4-triazolylphenyl, and 4-(2-oxopyrrolidin-1-yl)phenyl.
In the present context, the term “heteroaryl” is intended to mean a heterocyclic aromatic group where one or more carbon atoms in an aromatic ring have been replaced with one or more heteroatoms selected from the group comprising nitrogen, sulfur, and oxygen.
Furthermore, in the present context, the term “heteroaryl” comprises fused ring systems wherein at least one aryl ring and at least one heteroaryl ring, at least two heteroaryl rings, at least one heteroaryl ring and at least one heterocyclyl ring, or at least one heteroaryl ring and at least one cycloalkyl ring share at least one chemical bond.
The term “heteroaryl” is understood to relate to aromatic, C 3-8 cyclic groups further containing one oxygen or sulfur atom or up to four nitrogen atoms, or a combination of one oxygen or sulfur atom with up to two nitrogen atoms, and their substituted as well as benzo- and pyrido-fused derivatives, for example, connected via one of the ring-forming carbon atoms. Heteroaryl groups can carry one or more substituents, selected from halo, hydroxy, amino, cyano, nitro, alkylamido, acyl, C 1-6 -alkoxy, C 1-6 -alkyl, C 1-6 -hydroxyalkyl, C 1-6 -aminoalkyl, C 1-6 -alkylamino, alkylsulfenyl, alkylsulfinyl, alkylsulfonyl, sulfamoyl, or trifluoromethyl. In some embodiments, heteroaryl groups can be five- and six-membered aromatic heterocyclic systems carrying 0, 1, or 2 substituents, which can be the same as or different from one another, selected from the list above. Representative examples of heteroaryl groups include, but are not limited to, unsubstituted and mono- or di-substituted derivatives of furan, benzofuran, thiophene, benzothiophene, pyrrole, pyridine, indole, oxazole, benzoxazole, isoxazole, benzisoxazole, thiazole, benzothiazole, isothiazole, imidazole, benzimidazole, pyrazole, indazole, tetrazole, quionoline, isoquinoline, pyridazine, pyrimidine, purine and pyrazine, furazan, 1,2,3-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, triazole, benzotriazole, pteridine, phenoxazole, oxadiazole, benzopyrazole, quinolizine, cinnoline, phthalazine, quinazoline, and quinoxaline. In some embodiments, the substituents are halo, hydroxy, cyano, O—C 1-6 -alkyl, C 1-6 -alkyl, hydroxy-C 1-6 -alkyl, and amino-C 1-6 -alkyl.
The terms “purified,” “substantially purified,” and “isolated” as used herein refer to the compounds of the invention being free of other, dissimilar compounds with which the compounds of the invention are normally associated in their natural state, so that the compounds of the invention comprise at least 0.5%, 1%, 5%, 10%, or 20%, and most preferably at least 50% or 75% of the mass, by weight, of a given sample.
Synthesis
The compounds of this invention may be synthesized by methods described below, or by modification of these methods. Ways of modifying the methodology include, among others, temperature, solvent, reagents etc., and will be obvious to those skilled in the art. In general, during any of the processes for preparation of the compounds it may be necessary and/or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by means of conventional protecting groups, such as those described in Protective Groups in Organic Chemistry (ed. J. F. W. McOmie, Plenum Press, 1973); and Greene & Wuts, Protective Groups in Organic Synthesis , John Wiley & Sons, 1991, which are both hereby incorporated herein by reference in their entirety. The protecting groups may be removed at a convenient subsequent stage using methods known from the art. Synthetic chemistry transformations useful in synthesizing applicable compounds are known in the art and include e.g. those described in R. Larock, Comprehensive Organic Transformations , VCH Publishers, 1989, or L. Paquette, ed., Encyclopedia of Reagents for Organic Synthesis , John Wiley and Sons, 1995, which are both hereby incorporated herein by reference in their entirety.
The compounds of formula (I) and formula (II) can be prepared starting from halo-substituted aromatic rings such as C and C′ (Scheme 1) by base catalyzed aromatic nucleophilic substitution of a halogen with the appropriate amine D to get compounds of the general formula I, where R 1 , Z 1 , Z 2 , Z 3 , Z 4 , R 6 , R 7 , Y 1 , Y 2 are defined as above for formulas (I) and (II), or are suitable precursors thereof, and X represents a halide. The process may be carried out in a suitable solvent, e.g. an aprotic solvent such as toluene, acetonitrile, benzene, dioxane, DMSO, THF or DMF with a suitable base such as pyridine, DBU, and using an excess of the secondary amine (which also can act as the base). The reaction may occur at a temperature between +20° C. and +150° C. Alternatively, the reaction can be carried out under microwave irradiation at temperatures up to 300° C.
Alternatively, compounds according to formula (I) or formula (II) can be prepared by introducing the amine D through metal-catalysed (e.g. palladium or nickel) nucleophilic substitution on an appropriately substituted halo- or pseudohalo aryl (e.g. Br, I—, Cl—, triflate-, nonaflate-, tosylate-substituted aryl derivatives) (Hartwig, Angew. Chem. Int. Ed., 1998, 37, 2046-2067; Yang & Buchwald, J. Organometallic Chem., 1999, 576, 125-146; Hartwig in Modern Amination Methods ; Ricci, Ed.; Wiley-VCH: Weinheim, Germany, 2000) or Cu-catalyzed (Buchwald et al, Org. Lett., 2002, 4, 581-584, Kwong & Buchwald, Org. Lett., 2003, 5, 793-796). Metal-catalyzed amination reaction may also be performed under microwave irradation (T. Wang et al., Org. Lett., 2003, 5, 897-900); all of which are hereby incorporated herein by reference in their entirety.
Alternatively, compounds according to formula (I) or formula (II) may be prepared from the appropriately substituted aniline-based derivatives using an appropriate bifunctional alkylating agent as shown in Scheme 2, where R 1 , Z 1 , Z 2 , Z 3 , Z 4 , R 6 , R 7 , Y 1 , Y 2 are defined as above for formulas (I) and (II), or are suitable precursors thereof, and L 1 and L 2 represent a suitable leaving group. Non-limiting examples of leaving groups L 1 and L 2 are a halogen atom, e.g., chlorine, bromine or iodine, or a sulfonate, e.g., tosylate or mesylate, or another leaving group favoring the reaction. The reaction is conveniently carried out by stirring the reagent under basic conditions in an inert solvent, e.g., diisopropylethylamine in acetonitrile, or K 2 CO 3 in N,N-dimethylformamide. The reaction is typically carried out at temperatures between room temperature and 120° C.
The appropriate starting materials may be commercially available or may be prepared according to methodology disclosed in the literature. Substituents R 1 , Z 1 , Z 2 , Z 3 , Z 4 and any R 6 and R 7 may each be individually introduced at any appropriate stage of the preparation of the compounds, following procedures known in the literature.
Compounds according to formula (I) or formula (II) in which R 1 is nitro may be prepared by classical nitration methods well described in the literature, using HNO 3 /H 2 SO 4 or other methods known to those skilled in the art.
Compounds according to formula (I) or formula (II) in which Z 1 , Z 2 , Z 3 or Z 4 are halogen, may be prepared by classical halogenation methods described in the literature, using Br 2 or other methods known to those skilled in the art. Alternatively, an appropriately substituted aniline-based precursor can be converted into a halo-derivative via a diazotisation according to the Sandmeyer methodology using sodium nitrite in acetic acid or trifluoroacetic acid, and then reacted with e.g. with hexafluorophosphoric acid and decomposition of the resulting salt to obtain the fluoro derivative (W. Adcock et al., J. Am. Chem. Soc., 1967, 89, 386-390, which is hereby incorporated herein by reference in its entirety).
Compounds according to formula (I) or formula (II) in which R 1 , Z 1 , Z 2 , Z 3 or Z 4 are cyano, CONR 4 R 5 , or COOR 4 may be obtained by Pd catalyzed cyanation from corresponding iodides, bromides (Alterman & Hallberg, J. Org. Chem., 2000, 65, 7984-7989) and chlorides (Sundermeier et al, Angew. Chem. Int. ed, 2003, 42, 1661-1664) as well as by Ni mediated cyanation of aryl bromides and chlorides (Arvela & Leadbeater, J. Org. Chem., 2003, 68, 9122-9125); where all these reference are hereby incorporated herein by reference in their entirety. The nitriles may also be obtained by reaction of a halo-derivative or a Sandmeyer diazo-intermediate with cuprous cyanide. The aryl nitriles thus obtained can be either converted to the corresponding tetrazoles by microwave-induced cycloaddition chemistry (Alterman & Hallberg, J. Org. Chem., 2000, 65, 7984-7989, which is hereby incorporated herein by reference in its entirety) or hydrolyzed to corresponding carboxylic acids. In addition, compounds bearing carboxylic acid residues can be accessed from corresponding aryl iodides, bromides and triflates by Pd catalyzed hydroxycarbonylation chemistry (Cacchi et al, Org. Lett, 2003, 5, 4269-4293; which is hereby incorporated herein by reference in its entirety). Compounds bearing aryl amide residues can be accessed from corresponding aryl bromides by Pd catalyzed aminocarbonylation chemistry (Wan et al, J. Org. Chem., 2002, 67, 6232-6235; which is hereby incorporated herein by reference in its entirety). The carboxylic acids may be further derivatized to amides by classical acylation reactions or coupling agents methodology well described in the art.
Compounds according to formula (I) or formula (II) in which Z 1 , Z 2 , Z 3 or Z 4 , are S(O) n R 8 or SO 2 NR 8 R 9 may be prepared by direct aryl sulfonation by use of concentrated sulfuric acid, SO 3 or chlorosulphonic acid or by hydrolysis of a sulfonyl chloride. The sulfonyl chloride can be obtained by addition of SO 2 to a diazonium salt in the presence of cupric chloride. Alternatively, sulfonyl chlorides can be prepared by addition of SO 2 (forming a sulfinic acid salt) to aryl metal complexes, e.g. aryl lithium or aryl Grignard reagents, followed by reaction with sulfuryl chloride. Sulfonate esters can be obtained by reaction of the sulfonyl chlorides with alcohols. Sulfonic acid esters and sulfonamides are conveniently prepared from sulfonyl chlorides. Sulfones can be prepared Friedel-Craft type reaction of aromatic compounds with sulfonyl halides, by reaction of alkyl halides or sulfonates with aryl sulfinate salts, by addition of Grignard reagents to sulfonyl chlorides or by oxidation of thiophenols.
Compounds according to formula (I) or formula (II) in which Z 1 , Z 2 , Z 3 or Z 4 are alkoxy or OCOR 4 may be typically prepared by Williamson ether synthesis from the corresponding hydroxyaryl derivatives or by acylation using methods described below.
Compounds according to formula (I) or formula (II) in which Z 1 , Z 2 , Z 3 or Z 4 are COR 4 may be prepared from corresponding aryl iodides by Pd catalyzed acylation chemistry (Cacchi et al, Org. Lett, 2003, 5, 289-293, which is hereby incorporated herein by reference in its entirety). Alternatively, they may be obtained from the corresponding aryls by Friedel-Crafts chemistry (Read, J. Am. Chem. Soc., 1922, 44, 1746-1755, which is hereby incorporated herein by reference in its entirety), or by addition of aryl-Grignard reagents to nitriles (Whitmore et al, J. Am. Chem. Soc., 1947, 69, 235-237, which is hereby incorporated herein by reference in its entirety) or to acyl chlorides (Whitmore & Lester, J. Am. Chem. Soc., 1942, 64, 1247, which is hereby incorporated herein by reference in its entirety), or by either Pd-catalyzed (Gooβen and Ghosh, Angew. Chem. Int. Ed. Engl., 2001, 40, 3458-3460) or Rh-catalyzed acylation of arylboronic acids (Frost & Wadsworth, Chem. Commun., 2001, 22, 2316-2317; both of which are hereby incorporated herein by reference in their entirety).
Compounds according to formula (I) or formula (II) in which Z 1 , Z 2 , Z 3 or Z 4 are lower aminoalkyl, NHCOR 4 , or NHSO 2 R 4 may be obtained from an aniline-based precursor, which may be commercially available or may be obtained by reduction from a nitro-derivative prepared as described above, using e.g. Raney nickel and hydrazine or Pd or Pt catalysts and hydrogen. Alternatively, an aminoalkyl group can be introduced following the same methods as described above (Scheme 1) or by reductive amination (Emerson & Walters, J. Am. Chem. Soc., 1938, 60, 2023; Milovic et al, Synthesis, 1991, 11, 1043-1045, both of which are hereby incorporated herein by reference in their entirety), or by dehydrative alkylation (Rice & Kohn, J. Am. Chem. Soc., 1955, 77, 4052; Brown & Reid, J. Am. Chem. Soc., 1924, 46, 1838, both of which are hereby incorporated herein by reference in their entirety). Additionally, compounds of this type may also be synthesized from corresponding boronic acids by Cu-catalyzed coupling (Antilla & Buchwald, Org. Lett., 2001, 3, 2077-2079, which is hereby incorporated herein by reference in its entirety). The amino group can be further derivatized by alkylation, acylation (Wolf, Liebigs Ann. Chem., 1952, 576, 35; Yasukara et al, J. Chem. Soc. Perkin Trans. 1, 2000, 17, 2901-2902; Nigam & Weedon, J. Chem. Soc., 1957, 2000; all of which are hereby incorporated herein by reference in their entirety), formylation (Hirst & Cohen, J. Chem. Soc., 1895, 67, 830; Olah & Kuhn, Chem. Ber. 1956, 89, 2211; Guthrie et al, Can. J. Chem., 1993, 71, 2109-2122; all of which are hereby incorporated herein by reference in their entirety) or sulfonylation. Alternatively, compounds bearing amide substituents may be obtained from suitable halo or pseudohalo precursor either by Pd catalyzed (Yin & Buchwald, J. Am. Chem. Soc., 2002, 124, 6043-6048, which is hereby incorporated herein by reference in its entirety) or by Cu catalyzed amidation chemistries (Buchwald et al, J. Am. Chem. Soc., 2002, 124, 7421-7428, which is hereby incorporated herein by reference in its entirety).
Compounds according to formula (I) or formula (II) in which Z 1 , Z 2 , Z 3 or Z 4 are SR 4 may be obtained from a suitable halo- or pseudohalo precursor by Pd catalyzed (Li, J. Org. Chem., 2002, 67, 3643-3650, which is hereby incorporated herein by reference in its entirety), or Cu catalyzed thioetherification chemistry (Kwong & Buchwald, Org. Lett., 2002, 4, 3517-3520, which is hereby incorporated herein by reference in its entirety). Alternatively, these compounds may be prepared by alkylation of corresponding arylthiol precursors (Vogel, J. Chem. Soc., 1948, 1809; Landini & Rocca, Synthesis, 1974, 565-566; Bun-Hoi et al, J. Org. Chem., 1951, 16, 988; all of which are hereby incorporated herein by reference in their entirety). Alternatively, alkylarylsulfanyls may be obtained by irradiation of benzenethiols and alkenes (Screttas and Micha-Screttas, J. Org. Chem., 1978, 43, 1064-1071, which is hereby incorporated herein by reference in its entirety).
Furthermore, starting from aryl bromides and iodides, employing alkyl lithium and alkyl Grignard reagents, halogen-metal exchange chemistry can be utilized to introduce a broad range of electrophiles such as alkyls, —Si(R) 3 , —CHO, —COOH, —CN, —SO 2 N(R) 2 , —SR, —B(OR) 2 , —Sn(R) 3 , —ZnX (X═Br, Cl).
In general, an amine or alcohol functionality may be further derivatized, for example acylated using any carboxylic acid halide e.g., chloride, or carboxylic anhydride to give amides, as exemplified in Scheme 3 by amine or alcohol K, where R 5 and Aryl are defined in agreement with formula (I) or formula (II), Z 1 is OH, NH 2 , NHR 4 , or SH; Z 2 is O, NH, NR 4 , or S; Z 3 is O or S; X represents a halide, and R 4 is defined in agreement with formula (I) or formula (II). The reaction is typically carried out using an excess of the acylating agent and a suitable base, e.g., triethylamine or diisopropylethylamine in an inert solvent, e.g., dichloromethane, at a temperature between 0° C. and room temperature and under dry conditions. As an alternative to the carboxylic acid halides and carboxylic acid anhydrides, the amine/alcohol may be acylated using a carboxylic acid and a suitable coupling reagent e.g. PyBroP, DCC or EDCI. The reaction is typically carried out using an excess of the acylating agent and the coupling reagent in an inert solvent, e.g., dichloromethane, at a temperature between 0° C. and 100° C. under dry conditions.
Alternatively, an amine or alcohol functionality may be alkylated using an appropriate alkylating agents, such as T-L 1 . Leaving group L 1 is suitably a halogen atom, e.g., chlorine, bromine or iodine, or a sulfonate, e.g., tosylate or mesylate, or another leaving group favoring the reaction. The reaction is conveniently carried out by stirring the reagent under basic conditions in an inert solvent, e.g., diisopropylethylamine in acetonitrile, or K 2 CO 3 in N,N-dimethylformamide. The reaction is typically carried out at temperatures between room temperature and 80° C.
Furthermore, ketones, exemplified in Scheme 4 by tropanone derivative G, may be modified by reductive amination using any primary or secondary amine HNR 4 R 5 , where R 4 , R 5 and Aryl are defined in agreement with formula (I) or formula (II).
Alternatively the same methodology may be used to modify primary or secondary amines, exemplified by amine J (Scheme 4). The reaction is conveniently carried out by stirring the reactants in an inert solvent such as methanol or ethanol. As a reducing agent, solid-supported borohydride, NaBH 4 , NaCNBH 3 , BH 3 .pyridine, H 2 /Pd—C or any related reagent may be used, including solid-supported reagents. The reaction is typically carried out at room temperature, but less reactive carbonyl compounds may require higher temperatures and/or the pre-formation of the corresponding imine under water removal before addition of the reducing agent.
Furthermore, ketones, exemplified in Scheme 5 by tropanone derivative G, may be reacted with a variety of organometallic reagents, such as Grignard or lithium reagents, where R 6 and Aryl are defined in agreement with formula (I) or formula (II), to give derivatives such as K. The Grignard reaction is typically carried out in a solvent such as THF, and in some cases the addition of anhydrous cerium trichloride may improve the reaction yields.
Alternatively, ketones exemplified by tropanone G (Scheme 5) may be converted to epoxides L upon reaction with a sulfur ylide such as dimethylsulfoxonium methylide and dimethylsulfonium methylide, generated from trimethylsulfoxonium iodide or trimethylsulfonium iodide by addition of a base such as sodium hydride, in an inert solvent such as dimethylsulfoxide at a temperature of 0-40° C. Alternatively, ketone G can be converted into an olefin by a Wittig or Wadsworth-Homer-Emmons reaction, or by Tebbe olefination. The alkenes thus obtained may then be converted into the corresponding epoxide by treatment with oxidation reagents such as hydroperoxide or MCPBA. Epoxides such as derivative L may be further derivatized by reactions with a wide variety of nucleophiles, such as cyanide, alkoxides, amines, organometallic reagents, or carbanions derived from amide or sulfonamide derivatives upon treatment with base, to give tertiary alcohols exemplified by derivatives M1-M5, where R 4 , R 5 , R 6 , Nu and Aryl are defined in agreement with formula (I) or formula (II). Certain reactions can be facilitated by the addition of a Lewis acid catalyst such as Ytterbium triflate or boron trifluoride etherate. Furthermore, the epoxide may be reduced to the tertiary alcohol using a reducing agent such as LiAlH 4 , NaBH 4 /LiCl, Superhydride, borane, catalytic hydrogenation or any related reagent may be used, including solid-supported reagents. The reactions may typically be carried out at temperatures of 0-100° C. in solvents such as THF, diethylether, or diglyme.
Furthermore, the introduction of substituents on ring A or on the phenyl moiety may occur at any stage of the synthetic pathway, and thus ring A may be prepared first and its amine function reacted with a suitable phenyl precursor in a later step of the synthesis as shown in Scheme 6, in which the tropane derivative P exemplifies ring A as defined in formula (I) or formula (II). The amine function may require transient protecting groups (PG) such as Boc, CBz, benzyl, p-methoxybenzyl.
Where the processes for the preparation of the compounds of formula (I) or formula (II) give rise to mixtures of stereoisomers, such isomers may be separated by conventional techniques such as preparative chiral chromatography. The compounds may be prepared in racemic form or individual enantiomers may be prepared by stereoselective synthesis or by resolution. The compounds may be resolved into their component enantiomers by standard techniques, such as the formation of diastereomeric pairs by salt formation with an optically active acid, such as (−)-di-p-toluoyl-d-tartaric acid and/or (+)-di-p-toluoyl-1-tartaric acid, followed by fractional crystallization and regeneration of the free base. The compounds may also be resolved using a chiral auxiliary by formation of diastereomeric derivatives such as esters, amides or ketals followed by chromatographic separation and removal of the chiral auxiliary.
Methods of Use
In an embodiment of this invention, compounds of this invention are capable of modulating the activity of an androgen receptor.
The term “modulate” refers to the ability of a compound disclosed herein to alter the function of an androgen receptor. A modulator may activate the activity of an androgen receptor, may activate or inhibit the activity of an androgen receptor depending on the concentration of the compound exposed to the androgen receptor, or may inhibit the activity of an androgen receptor. The term “modulate” also refers to altering the function of an androgen receptor by increasing or decreasing the probability that a complex forms between an androgen receptor and a natural binding partner. A modulator may increase the probability that such a complex forms between the androgen receptor and the natural binding partner, may increase or decrease the probability that a complex forms between the androgen receptor and the natural binding partner depending on the concentration of the compound exposed to the androgen receptor, and or may decrease the probability that a complex forms between the androgen receptor and the natural binding partner. Modulation of the androgen receptor may be assessed using Receptor Selection and Amplification Technology (R-SAT) as described in U.S. Pat. No. 5,707,798, the disclosure of which is incorporated herein by reference in its entirety.
The term “activate” refers to increasing the cellular function of an androgen receptor. The term “inhibit” refers to decreasing the cellular function of an androgen receptor. The androgen receptor function may be the interaction with a natural binding partner or catalytic activity.
The term “contacting” as used herein refers to bringing a compound disclosed herein and a target androgen receptor together in such a manner that the compound can affect the activity of the androgen receptor, either directly; i.e., by interacting with the androgen receptor itself, or indirectly; i.e., by interacting with another molecule on which the activity of the androgen receptor is dependent. Such “contacting” can be accomplished in a test tube, a petri dish or the like. In a test tube, contacting may involve only a compound and a androgen receptor of interest or it may involve whole cells. Cells may also be maintained or grown in cell culture dishes and contacted with a compound in that environment. In this context, the ability of a particular compound to affect an androgen receptor related disorder; i.e., the IC 50 of the compound can be determined before use of the compounds in vivo with more complex living organisms is attempted. For cells outside the organism, multiple methods exist, and are well-known to those skilled in the art, to get the androgen receptors in contact with the compounds including, but not limited to, direct cell microinjection and numerous transmembrane carrier techniques. The term “contacting” can also refer to bringing a compound disclosed herein to contact with a target androgen receptor in vivo. Thus, if a compound disclosed herein, or a prodrug thereof, is administered to an organism and the compound is brought together with an androgen receptor within the organism, such contacting is within the scope of the present disclosure.
In an embodiment hereof, a compound of this invention may be an agonist of an androgen receptor, while in other embodiments, the compound may be an antagonist of an androgen receptor. In an embodiment hereof, the compound may be a partial agonist of an androgen receptor. A compound that is a partial agonists may in some cases be a partial activator of a receptor, while in other cases may be a partial repressor of a receptor. In an embodiment of this invention, the compound may be a tissue-specific modulator, while in other circumstances, the compound may be a gene-specific modulator.
In an embodiment of this invention, an androgen receptor is activated by contacting it with a compound of formula (I) or formula (II). The contacting of the androgen receptor may be in vivo or in vitro. When the receptor is contacted in vivo, the contacting may be accomplished by administering the compound to the living subject containing the receptor. In some embodiments, the living subject is a patient. In an embodiment of this invention, the patient may be a mammal. The mammal may be selected from the group consisting of mice, rats, rabbits, guinea pigs, dogs, cats, sheep, goats, cows, primates, such as monkeys, chimpanzees, and apes, and humans. In an embodiment of this invention, the patient is a human.
In an embodiment hereof, a compound of this invention may be administered to a patient in order to treat a condition in the patient. Such conditions include, without limitation, hypogonadism, lower than normal testosterone plasma levels, infertility, sexual arousal disorder, sexual orgasmic disorders, disorders of libido, muscle wasting due to cachexia, HIV wasting, or critical illnesses, sarcopenia, frailty, short stature, dwarfism, bone density loss, mood disorders including lack of well being, lack of vigor, anger, irritability, sadness, tiredness, nervousness, depression, impaired cognitive functions including verbal fluency and spatial memory, neurodegenerative disorders, including Alzheimer's disease, Mild cognition impairment (MCI), Lewis body dementia, and frontal temporal dementia, xerophthalmia, metabolic disorders, including dyslipidemia, atherosclerosis, and non-insulin dependent diabetes (NIDDM), cardiovascular disorders including but not limited to hypertension, coronary artery disease, and myocardial perfusion, obesity, anemia, prostate cancer, and schizophrenia. In an embodiment hereof, a compound of this invention may be administered to a patient in order to prevent a condition in the patient. The condition prevented includes, without limitation, bone density loss; xerophthalmia; metabolic disorders, including dyslipidemia, atherosclerosis, and non-insulin dependent diabetes (NIDDM); cardiovascular disorders including hypertension, coronary artery disease, and myocardial perfusion; obesity; and prostate cancer.
In an embodiment hereof, a compound of this invention is effective in treating certain conditions in male patients. Thus, the compound may be administered to the male patient in order to treat one or more of the conditions. The condition treated in the male includes, without limitation, infertility, erectile dysfunction, andropause, and disorders of libido. In an embodiments hereof, a compound of this invention may be administered to a male patient in order to modulate spermatogenesis in the male patient.
In an embodiment hereof, a compound of this invention is effective in treating certain conditions in female patients. Thus, the compound may be administered to the female patient in order to treat one or more of the conditions. The condition treated in the female includes, without limitation, endometriosis, dyspareunia, vaginismus, sexual arousal disorder, and sexual orgasmic disorder.
In an embodiment hereof, a compound of this invention may be administered to a patient in order to effect hormone replacement.
In an embodiment hereof, a compound of this invention may be administered to a patient in order to improve muscle strength. For example, the compound may be administered in need of improvement in muscle strength due to muscular dystrophy, mytonic dystrophy, or glucocorticoid-treated asthma.
In an embodiment hereof, a compound of this invention may be administered to a patient in order to improve a health-related quality of life parameter such as survival, impairment, functional status, health perception, and opportunities.
In an embodiment hereof, a compound of this invention may be administered to a male patient suffering from prostate cancer in order to delay the progression of the prostate cancer.
Pharmaceutical Compositions
An embodiment of this invention relates to a pharmaceutical composition comprising a physiologically acceptable surface active agents, carriers, diluents, excipients, smoothing agents, suspension agents, film forming substances, and coating assistants, or a combination thereof; and a compound disclosed herein. Acceptable carriers or diluents for therapeutic use are well known in the pharmaceutical art, and are described, for example, in Remington's Pharmaceutical Sciences, 18th Ed., Mack Publishing Co., Easton, Pa. (1990), which is incorporated herein by reference in its entirety. Preservatives, stabilizers, dyes, sweeteners, fragrances, flavoring agents, and the like may be provided in the pharmaceutical composition. For example, sodium benzoate, ascorbic acid and esters of p-hydroxybenzoic acid may be added as preservatives. In addition, antioxidants and suspending agents may be used. Alcohols, esters, sulfated aliphatic alcohols, and the like may be used as surface active agents; sucrose, glucose, lactose, starch, crystallized cellulose, mannitol, light anhydrous silicate, magnesium aluminate, magnesium methasilicate aluminate, synthetic aluminum silicate, calcium carbonate, sodium acid carbonate, calcium hydrogen phosphate, calcium carboxymethyl cellulose, and the like may be used as excipients; magnesium stearate, talc, hardened oil and the like may be used as smoothing agents; coconut oil, olive oil, sesame oil, peanut oil, soya may be used as suspension agents or lubricants; cellulose acetate phthalate as a derivative of a carbohydrate such as cellulose or sugar, or methylacetate-methacrylate copolymer as a derivative of polyvinyl may be used as suspension agents; and plasticizers such as ester phthalates and the like may be used as suspension agents.
The term “pharmaceutical composition” refers to a mixture of a compound disclosed herein with other chemical components, such as diluents or carriers. The pharmaceutical composition facilitates administration of the compound to an organism. Multiple techniques of administering a compound exist in the art including, but not limited to, oral, injection, aerosol, parenteral, and topical administration. Pharmaceutical compositions can also be obtained by reacting compounds with inorganic or organic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid and the like.
The term “carrier” defines a chemical compound that facilitates the incorporation of a compound into cells or tissues. For example dimethyl sulfoxide (DMSO) is a commonly utilized carrier as it facilitates the uptake of many organic compounds into the cells or tissues of an organism.
The term “diluent” defines chemical compounds diluted in water that will dissolve the compound of interest as well as stabilize the biologically active form of the compound. Salts dissolved in buffered solutions are utilized as diluents in the art. One commonly used buffered solution is phosphate buffered saline because it mimics the salt conditions of human blood. Since buffer salts can control the pH of a solution at low concentrations, a buffered diluent rarely modifies the biological activity of a compound.
The term “physiologically acceptable” defines a carrier or diluent that does not abrogate the biological activity and properties of the compound.
The pharmaceutical compositions described herein can be administered to a human patient per se, or in pharmaceutical compositions where they are mixed with other active ingredients, as in combination therapy, or suitable carriers or excipient(s). Techniques for formulation and administration of the compounds of the instant application may be found in “Remington's Pharmaceutical Sciences,” Mack Publishing Co., Easton, Pa., 18th edition, 1990.
Suitable routes of administration may, for example, include oral, rectal, transmucosal, topical, or intestinal administration; parenteral delivery, including intramuscular, subcutaneous, intravenous, intramedullary injections, as well as intrathecal, direct intraventricular, intraperitoneal, intranasal, or intraocular injections. The compounds can also be administered in sustained or controlled release dosage forms, including depot injections, osmotic pumps, pills, transdermal (including electrotransport) patches, and the like, for prolonged and/or timed, pulsed administration at a predetermined rate.
The pharmaceutical compositions of the present invention may be manufactured in a manner that is itself known, e.g., by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or tabletting processes.
Pharmaceutical compositions for use in accordance with the present invention thus may be formulated in conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen. Any of the well-known techniques, carriers, and excipients may be used as suitable and as understood in the art; e.g., in Remington's Pharmaceutical Sciences, above.
Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, mannitol, lactose, lecithin, albumin, sodium glutamate, cysteine hydrochloride, and the like. In addition, if desired, the injectable pharmaceutical compositions may contain minor amounts of nontoxic auxiliary substances, such as wetting agents, pH buffering agents, and the like. Physiologically compatible buffers include, but are not limited to, Hanks's solution, Ringer's solution, or physiological saline buffer. If desired, absorption enhancing preparations (for example, liposomes), may be utilized.
For transmucosal administration, penetrants appropriate to the barrier to be permeated may be used in the formulation.
Pharmaceutical formulations for parenteral administration, e.g., by bolus injection or continuous infusion, include aqueous solutions of the active compounds in water-soluble form. Additionally, suspensions of the active compounds may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or other organic oils such as soybean, grapefruit or almond oils, or synthetic fatty acid esters, such as ethyl oleate or triglycerides, or liposomes. Aqueous injection suspensions may contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers or agents that increase the solubility of the compounds to allow for the preparation of highly concentrated solutions. Formulations for injection may be presented in unit dosage form, e.g., in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.
For oral administration, the compounds can be formulated readily by combining the active compounds with pharmaceutically acceptable carriers well known in the art. Such carriers enable the compounds of the invention to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated. Pharmaceutical preparations for oral use can be obtained by combining the active compounds with solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate. Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active compound doses. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active compound doses.
Pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. All formulations for oral administration should be in dosages suitable for such administration.
For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.
For administration by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of, e.g., gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.
Further disclosed herein are various pharmaceutical compositions well known in the pharmaceutical art for uses that include intraocular, intranasal, and intraauricular delivery. Suitable penetrants for these uses are generally known in the art. Pharmaceutical compositions for intraocular delivery include aqueous ophthalmic solutions of the active compounds in water-soluble form, such as eyedrops, or in gellan gum (Shedden et al., Clin. Ther., 23(3):440-50 (2001)) or hydrogels (Mayer et al., Ophthalmologica, 210(2):101-3 (1996)); ophthalmic ointments; ophthalmic suspensions, such as microparticulates, drug-containing small polymeric particles that are suspended in a liquid carrier medium (Joshi, A., J. Ocul. Pharmacol., 10(1):29-45 (1994)), lipid-soluble formulations (Alm et al., Prog. Clin. Biol. Res., 312:447-58 (1989)), and microspheres (Mordenti, Toxicol. Sci., 52(1):101-6 (1999)); and ocular inserts. All of the above-mentioned references, are incorporated herein by reference in their entireties. Such suitable pharmaceutical formulations are most often and preferably formulated to be sterile, isotonic and buffered for stability and comfort. Pharmaceutical compositions for intranasal delviery may also include drops and sprays often prepared to simulate in many respects nasal secretions to ensure maintenance of normal ciliary action. As disclosed in Remington's Pharmaceutical Sciences, 18th Ed., Mack Publishing Co., Easton, Pa. (1990), which is incorporated herein by reference in its entirety, and well-known to those skilled in the art, suitable formulations are most often and preferably isotonic, slightly buffered to maintain a pH of 5.5 to 6.5, and most often and preferably include antimicrobial preservatives and appropriate drug stabilizers. Pharmaceutical formulations for intra-auricular delivery include suspensions and ointments for topical application in the ear. Common solvents for such aural formulations include glycerin and water.
The compounds may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
In addition to the formulations described previously, the compounds may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
For hydrophobic compounds, a suitable pharmaceutical carrier may be a cosolvent system comprising benzyl alcohol, a nonpolar surfactant, a water-miscible organic polymer, and an aqueous phase. A common cosolvent system used is the VPD co-solvent system, which is a solution of 3% w/v benzyl alcohol, 8% w/v of the nonpolar surfactant Polysorbate 80™, and 65% w/v polyethylene glycol 300, made up to volume in absolute ethanol. Naturally, the proportions of a co-solvent system may be varied considerably without destroying its solubility and toxicity characteristics. Furthermore, the identity of the co-solvent components may be varied: for example, other low-toxicity nonpolar surfactants may be used instead of POLYSORBATE 80™; the fraction size of polyethylene glycol may be varied; other biocompatible polymers may replace polyethylene glycol, e.g., polyvinyl pyrrolidone; and other sugars or polysaccharides may substitute for dextrose.
Alternatively, other delivery systems for hydrophobic pharmaceutical compounds may be employed. Liposomes and emulsions are well known examples of delivery vehicles or carriers for hydrophobic drugs. Certain organic solvents such as dimethylsulfoxide also may be employed, although usually at the cost of greater toxicity. Additionally, the compounds may be delivered using a sustained-release system, such as semipermeable matrices of solid hydrophobic polymers containing the therapeutic agent. Various sustained-release materials have been established and are well known by those skilled in the art. Sustained-release capsules may, depending on their chemical nature, release the compounds for a few weeks up to over 100 days. Depending on the chemical nature and the biological stability of the therapeutic reagent, additional strategies for protein stabilization may be employed.
Agents intended to be administered intracellularly may be administered using techniques well known to those of ordinary skill in the art. For example, such agents may be encapsulated into liposomes. All molecules present in an aqueous solution at the time of liposome formation are incorporated into the aqueous interior. The liposomal contents are both protected from the external micro-environment and, because liposomes fuse with cell membranes, are efficiently delivered into the cell cytoplasm. The liposome may be coated with a tissue-specific antibody. The liposomes will be targeted to and taken up selectively by the desired organ. Alternatively, small hydrophobic organic molecules may be directly administered intracellularly.
Additional therapeutic or diagnostic agents may be incorporated into the pharmaceutical compositions. Alternatively or additionally, pharmaceutical compositions may be combined with other compositions that contain other therapeutic or diagnostic agents.
Methods of Administration
The compounds or pharmaceutical compositions of this invention may be administered to the patient by any suitable means. Non-limiting examples of methods of administration include, among others, (a) administration though oral pathways, which administration includes administration in capsule, tablet, granule, spray, syrup, or other such forms; (b) administration through non-oral pathways such as rectal, vaginal, intraurethral, intraocular, intranasal, or intraauricular, which administration includes administration as an aqueous suspension, an oily preparation or the like or as a drip, spray, suppository, salve, ointment or the like; (c) administration via injection, subcutaneously, intraperitoneally, intravenously, intramuscularly, intradermally, intraorbitally, intracapsularly, intraspinally, intrasternally, or the like, including infusion pump delivery; (d) administration locally such as by injection directly in the renal or cardiac area, e.g., by depot implantation; as well as (e) administration topically; as deemed appropriate by those of skill in the art for bringing the compound of the invention into contact with living tissue.
Pharmaceutical compositions suitable for administration include compositions where the active ingredients are contained in an amount effective to achieve its intended purpose. The therapeutically effective amount of the compounds disclosed herein required as a dose will depend on the route of administration, the type of animal, including human, being treated, and the physical characteristics of the specific animal under consideration. The dose can be tailored to achieve a desired effect, but will depend on such factors as weight, diet, concurrent medication and other factors which those skilled in the medical arts will recognize. More specifically, a therapeutically effective amount means an amount of compound effective to prevent, alleviate or ameliorate symptoms of disease or prolong the survival of the subject being treated. Determination of a therapeutically effective amount is well within the capability of those skilled in the art, especially in light of the detailed disclosure provided herein.
As will be readily apparent to one skilled in the art, the useful in vivo dosage to be administered and the particular mode of administration will vary depending upon the age, weight and mammalian species treated, the particular compounds employed, and the specific use for which these compounds are employed. The determination of effective dosage levels, that is the dosage levels necessary to achieve the desired result, can be accomplished by one skilled in the art using routine pharmacological methods. Typically, human clinical applications of products are commenced at lower dosage levels, with dosage level being increased until the desired effect is achieved. Alternatively, acceptable in vitro studies can be used to establish useful doses and routes of administration of the compositions identified by the present methods using established pharmacological methods.
In non-human animal studies, applications of potential products are commenced at higher dosage levels, with dosage being decreased until the desired effect is no longer achieved or adverse side effects disappear. The dosage may range broadly, depending upon the desired affects and the therapeutic indication. Typically, dosages may be between about 10 microgram/kg and 100 mg/kg body weight, preferably between about 100 microgram/kg and 10 mg/kg body weight. Alternatively dosages may be based and calculated upon the surface area of the patient, as understood by those of skill in the art.
The exact formulation, route of administration and dosage for the pharmaceutical compositions of the present invention can be chosen by the individual physician in view of the patient's condition. (See e.g., Fingl et al. 1975, in “The Pharmacological Basis of Therapeutics”, which is hereby incorporated herein by reference in its entirety, with particular reference to Ch. 1, p. 1). Typically, the dose range of the composition administered to the patient can be from about 0.5 to 1000 mg/kg of the patient's body weight. The dosage may be a single one or a series of two or more given in the course of one or more days, as is needed by the patient. In instances where human dosages for compounds have been established for at least some condition, the present invention will use those same dosages, or dosages that are between about 0.1% and 500%, more preferably between about 25% and 250% of the established human dosage. Where no human dosage is established, as will be the case for newly-discovered pharmaceutical compounds, a suitable human dosage can be inferred from ED 50 or ID 50 values, or other appropriate values derived from in vitro or in vivo studies, as qualified by toxicity studies and efficacy studies in animals.
It should be noted that the attending physician would know how to and when to terminate, interrupt, or adjust administration due to toxicity or organ dysfunctions. Conversely, the attending physician would also know to adjust treatment to higher levels if the clinical response were not adequate (precluding toxicity). The magnitude of an administrated dose in the management of the disorder of interest will vary with the severity of the condition to be treated and to the route of administration. The severity of the condition may, for example, be evaluated, in part, by standard prognostic evaluation methods. Further, the dose and perhaps dose frequency, will also vary according to the age, body weight, and response of the individual patient. A program comparable to that discussed above may be used in veterinary medicine.
Although the exact dosage will be determined on a drug-by-drug basis, in most cases, some generalizations regarding the dosage can be made. The daily dosage regimen for an adult human patient may be, for example, an oral dose of between 0.1 mg and 2000 mg of each active ingredient, preferably between 1 mg and 500 mg, e.g. 5 to 200 mg. In other embodiments, an intravenous, subcutaneous, or intramuscular dose of each active ingredient of between 0.01 mg and 100 mg, preferably between 0.1 mg and 60 mg, e.g. 1 to 40 mg is used. In cases of administration of a pharmaceutically acceptable salt, dosages may be calculated as the free base. In some embodiments, the composition is administered 1 to 4 times per day. Alternatively the compositions of the invention may be administered by continuous intravenous infusion, preferably at a dose of each active ingredient up to 1000 mg per day. As will be understood by those of skill in the art, in certain situations it may be necessary to administer the compounds disclosed herein in amounts that exceed, or even far exceed, the above-stated, preferred dosage range in order to effectively and aggressively treat particularly aggressive diseases or infections. In some embodiments, the compounds will be administered for a period of continuous therapy, for example for a week or more, or for months or years.
Dosage amount and interval may be adjusted individually to provide plasma levels of the active moiety which are sufficient to maintain the modulating effects, or minimal effective concentration (MEC). The MEC will vary for each compound but can be estimated from in vitro data. Dosages necessary to achieve the MEC will depend on individual characteristics and route of administration. However, HPLC assays or bioassays can be used to determine plasma concentrations.
Dosage intervals can also be determined using MEC value. Compositions should be administered using a regimen which maintains plasma levels above the MEC for 10-90% of the time, preferably between 30-90% and most preferably between 50-90%.
In cases of local administration or selective uptake, the effective local concentration of the drug may not be related to plasma concentration.
The amount of composition administered will, of course, be dependent on the subject being treated, on the subject's weight, the severity of the affliction, the manner of administration and the judgment of the prescribing physician.
Compounds disclosed herein can be evaluated for efficacy and toxicity using known methods. For example, the toxicology of a particular compound, or of a subset of the compounds, sharing certain chemical moieties, may be established by determining in vitro toxicity towards a cell line, such as a mammalian, and preferably human, cell line. The results of such studies are often predictive of toxicity in animals, such as mammals, or more specifically, humans. Alternatively, the toxicity of particular compounds in an animal model, such as mice, rats, rabbits, or monkeys, may be determined using known methods. The efficacy of a particular compound may be established using several recognized methods, such as in vitro methods, animal models, or human clinical trials. Non-limiting examples of appropriate in vitro animal models include castrated male rats or aged male orchidectomized rats. When selecting a model to determine efficacy, the skilled artisan can be guided by the state of the art to choose an appropriate model, dose, and route of administration, and regime. Of course, human clinical trials can also be used to determine the efficacy of a compound in humans.
The compositions may, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active ingredient. The pack may for example comprise metal or plastic foil, such as a blister pack. The pack or dispenser device may be accompanied by instructions for administration. The pack or dispenser may also be accompanied with a notice associated with the container in form prescribed by a governmental agency regulating the manufacture, use, or sale of pharmaceuticals, which notice is reflective of approval by the agency of the form of the drug for human or veterinary administration. Such notice, for example, may be the labeling approved by the U.S. Food and Drug Administration for prescription drugs, or the approved product insert. Compositions comprising a compound of the invention formulated in a compatible pharmaceutical carrier may also be prepared, placed in an appropriate container, and labeled for treatment of an indicated condition.
EXAMPLES
General Procedures
NMR Methods. Unless otherwise stated, 1 H NMR spectra were recorded on a Bruker Ultrashield 300 MHz and chemical shifts are given in δ-values [ppm] referenced to the residual solvent peak chloroform (CDCl 3 ) at 7.26 and methanol (CD 3 OD) at 3.31 ppm. 1 H NMR spectra were recorded at 400 MHz on a Varian Mercury-VX400 MHz spectrometer. Coupling constants, J, are reported in Hertz. The NMR spectra of the compounds are described for their free amine form. Materials and solvents were of the highest grade available from commercial sources and were used without further purification.
LC/MS Method I. The analysis was performed on a combined prep/analytical Waters/Micromass system consisting of a ZMD single quadropole mass spectrometer equipped with electrospray ionization interface. The HPLC system consisted of a Waters 600 gradient pump with on-line degassing, a 2700 sample manager and a 996 PDA detector. Separation was performed on an X-Terra MS C18, 5 μm 4.6×50 mm column. Buffer A: 10 mM ammonium acetate in water, buffer B: 10 mM ammonium acetate in acetonitrile/water 95/5. A gradient was run from 30% B to 100% B in 7 min, hold at 100% B for 1 min and re-equilibrated for 5.5 min. The system was operated at 1 ml/min.
LC/MS Method II. The analysis was performed on a Waters/Micromass LC/MS system consisting of a ZQ single quadropole mass spectrometer equipped with electro-spray ionization interface. The HPLC was a Waters 2795 Alliance HT system with a 996 PDA detector. Separation was performed on an X-Terra MS C18, 3.5 μm 4.6×30 mm column. Buffer A: 10 mM ammonium acetate in water, buffer B: 10 mM ammonium acetate in acetonitrile/water 95/5. A gradient was run from 30% B to 100% B in 5.5 min, stay at 100% B for 0.5 min, re-equilibrate for 2.5 min. System was operated at 1 mL/min.
LC/MS Method III. The analysis was performed on a combined prep/analytical Waters/Micromass system consisting of a ZMD single quadropole mass spectrometer equipped with electro-spray ionization interface. The HPLC system consisted of a Waters 600 gradient pump with on-line degassing, a 2700 sample manager and a 996 PDA detector.
Separation was performed on an YMC C18 J'sphere ODS H80, 5 μm 4.6×100 mm column. Buffer A: 0.15% TFA in water, buffer B: 0.15% TFA in acetonitrile/water 95/5. A gradient was run from 30% B to 100% B in 10 min, stay at 100% B for 2 min, re-equilibrate for 5 min. System was operated at 1 ml/min.
Preparation of hydrochloride salts. Typically, the compounds were dissolved in dichloromethane, treated with an excess of 1M HCl in diethylether and precipitated from n-heptane. The solvents were removed in vacuo and after drying, the hydrochloride salts were obtained as solids.
Example 1
endo-8-(3-chloro-2-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol (173FBA73bL)
To a solution of 198RL41 (0.050 g, 0.264 mmol) in pyridine (0.5 mL) was added nortropine (0.134 g, 1.056 mmol) and the reaction mixture was allowed to stir at 90° C. during 17 h. The mixture was diluted with ethyl acetate and the organic phase washed with 0.4 N HCl and sat. aq. NaHCO 3 ; evaporation of the dried (Na 2 SO 4 ) organic phase gave a crude product (0.055 g) which was purified by preparative TLC (n-heptane/ethyl acetate 7:3). Extraction of the lower R f band afforded 173FBA73bL (0.026 g).
LC/MS m/z 297 [M+H] + . 1 H-NMR (CDCl 3 , 300 MHz) δ 7.62 (d, 1H, J=9.0), 6.72 (d, 1H, J=9.0), 4.14 (t, 1H, J=4.9), 3.76 (br s, 2H), 2.35 (s, 3H), 2.25-2.13 (m, 4H), 1.94-1.79 (m, 4H). 13 C-NMR (CDCl 3 , 75 MHz) 155.6, 142.1, 130,7, 129.4, 124.5, 114.5, 65.1, 59.1, 40.5, 27.9, 18.3.
Example 2
3-Bromo-2-chloro-6-fluorotoluene (165RL91)
2-chloro-6-fluorotoluene (5.00 g, 34.6 mmol) and iron (0.1 g, 0.17 mmol) was stirred in a 100 mL flask. Bromine (6.08 g, 38.1 mmol) was added slowly in 3 portions with 1 min between each addition. The reaction was stirred for additional 15 min. Then dichloromethane (50 ml) was added, the reaction mixture transferred to a separation funnel and washed with a sodium thiosulphate solution (10%, 30 mL) until it had turned colorless. The layers were separated and the organic layer was washed with sat. sodium hydrogen carbonate (30 mL), dried and evaporated to give the title compound as a colorless oil (7.57 g, 98%) containing 15% 3-bromo-5-chloro-2-fluorotoluene (calc. by 1 H-NMR). The compound was used in the next step without further purification.
GC/MS m/z 222 [M+H] + . 1 H-NMR (CDCl 3 , 300 MHz) δ 7.53 (dd, 1H, J=5.5, 8.6, Ar—H), 7.07 (t, 1H, J=8.6, Ar—H), 2.35 (d, 3H, J=2.3, CH 3 ).
Example 3
2-Chloro-4-fluoro-3-methylbenzonitrile (165RL87a)
3-Bromo-2-chloro-6-fluorotoluene 165RL91 (173 mg, 0.78 mmol), zinc cyanide (91 mg, 0.78 mmol) and tetrakis(triphenylphosphine)palladium(0) (27 mg, 23 μmol) was charged in a vial, DMF (1 mL) added, and the mixture irradiated for 150 sec at 200° C. in a microwave oven. Diethyl ether (30 ml) was added and the reaction mixture washed with magnesium sulphate (4% solution, 3×20 mL) followed by brine (20 mL). The organic layer was dried and evaporated. The product was further purified by column chromatography on silica gel using n-heptane/ethyl acetate (9:1) giving a white solid (55 mg, 42%).
GC/MS m/z 169 [M+H] + . 1 H-NMR (CDCl 3 , 300 MHz) δ 7.43 (dd, 1H, J=5.6, 8.8, Ar—H), 6.87 (t, 1H, J=8.8, Ar—H), 2.36 (d, 3H, J=2.4, CH 3 ).
Example 4
2-Chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]octan-8-yl)-3-methylbenzonitrile, hydrochloride (165RL90)
2-Chloro-4-fluoro-3-methylbenzonitrile (165RL87a, 55 mg, 0.32 mmol) and nortropine (165 mg, 1.29 mmol) was dissolved in pyridine (2 mL) and the mixture irradiated at 220° C. for 2 hours in a microwave oven. Dichloromethane (50 mL) was added and the mixture washed with hydrochloric acid (0.4 M, 2×30 mL) followed by sat. sodium hydrogen carbonate (20 mL). The organic layer was dried over sodium sulfate, filtered and evaporated. The product was further purified by column chromatography using dichloromethane to give the title compound (16.2 mg, 18%).
R f =0.45 (CH 2 Cl 2 ). LC/MS m/z 277 [M+H] + . 1 H-NMR (CDCl 3 , 300 MHz) δ 7.37 (d, 1H, J=8.6, Ar—H), 6.78 (d, 1H, J=8.6, Ar—H), 4.20 (m, 1H, Tr-H), 3.80 (m, 2H, Tr-H), 2.37 (s, 3H, Ar—CH 3 ), 2.32-2.22 (m, 4H, Tr-H), 1.98-1,81 (m, 4H, Tr-H).
Example 5
2-(trifluoromethyl)-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]octan-8-yl)benzonitrile (196MBT4-B)
Nortropine (269 mg, 2.12 mmol) and 4-fluoro-2-(trifluoromethyl)benzonitrile (100 mg, 0.529 mmol) were dissolved in pyridine (2 mL). The mixture was heated to 100° C. in a sealed flask for 6 hours and then concentrated. The residue was dissolved in 2 M HCl (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated, and the resulting oil was purified by preparative TLC (eluting with dichloromethane) to afford 133 mg (85%) of the title compound as a colorless solid.
LC/MS m/z 297 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.65-6.75 (m, 3H), 4.35-4.28 (m, 2H), 4.12-4.05 (m, 1H), 2.48-2.39 (m, 2H), 2.17-2.04 (m, 4H), 1.82-1.73 (m, 2H), 1.60-1.52 (m, 1H).
Example 6
3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (197FBA17d)
Trimethylsulfoxonium iodide (7.33 g, 33.3 mmol) was slowly added to a suspension of NaH (55-65% dispersion in mineral oil, 1.45 g, 33.3 mmol) in DMSO (20 mL) and the reaction mixture was stirred for 1 h. A solution of Boc-tropinone (5.0 g, 22.2 mmol) was added and the mixture was stirred at r.t. for 20 h. Aqueous work-up (EtOAc/H 2 O) and evaporation of the dried (MgSO 4 ) organic phase gave the crude epoxide spiro[8-azabicyclo[3.2.1]octane-3,2′-oxirane]-8-carboxylic acid tert-butyl ester (197FBA10a), which was used in the next step without further purification.
Super-Hydride® (1.0 M THF solution, 29.0 mmol, 29.0 mL) was added to a solution of 197FBA10a (5.3 g, 22.2 mmol) in dry THF (10 mL), cooled with a water bath, and the reaction mixture was stirred at r.t. After 1 h the mixture was cooled again (ice bath), slowly quenched with water (10 mL), the aqueous phase was saturated with K 2 CO 3 , and the reaction mixture was extracted with diethylether. The organic phase was dried and evaporated to give a crude product which was taken up in ethyl acetate (200 mL) and filtered through a silica pad to give 197FBA17d as a colorless oil (4.11 g, 77%).
GC-MS m/z 241. 1 H-NMR (CDCl 3 ) 4.19 (m, 2H), 2.18-2.12 (m, 2H), 1.95-1.89 (m, 4H), 1.66 (d, J=14.3, 2H), 1.46 (s, 9H), 1.17 (s, 3H).
Example 7
endo-3-exo-methyl-8-azabicyclo[3.2.1]octan-3-ol hydrochloride (197FBA20a)
4 M HCl solution in dioxane (40 mL) was added to solution of 197FBA17d (3.81 g, 15.8 mmol) in diethylether (40 mL). The reaction mixture was stirred during 2 h, then evaporated to give a white solid, which was filtered, washed with heptane (70 mL), and dried to give 197FBA20a as a white solid (2.17 g, 77%).
1 H-NMR (DMSO-d 6 ) δ 3.87 (br s, 2H), 2.27 (d, J=7.3, 2H), 2.00 (dd, J=14.9 and 3.2, 2H), 1.87-1.83 (m, 2H), 1.74 (d, J=14.6, 2H), 1.07 (s, 3H).
Example 8
2-Chloro-4-fluoro-3-methylbenzonitrile (198RL18)
3-Bromo-2-chloro-6-fluorotoluene (7.0 g, 31 mmol), zinc cyanide (3.7 g, 31 mmol) and tetrakis(triphenylphosphine)palladium(0) (1.81 g, 1.56 mmol) was added to a flask under argon atmosphere. Dry DMF (35 mL) was added and the reaction mixture was stirred under argon at 120° C. The reaction was monitored by GC-MS and full conversion was observed after 2 hours. The mixture was diluted with dichloromethane (300 mL), washed with water (100 mL) and 4% magnesium sulfate solution (100 mL), dried over magnesium sulphate, filtered, and evaporated to give a clear oil. The product was further purified by column chromatography on silica gel using n-heptane/ethyl acetate (9:1) giving a white solid (3.79 g, 71%).
1 H-NMR (CDCl 3 ) δ 7.43 (dd, 1H, J=5.6, 8.8, Ar—H), 6.87 (t, 1H, J=8.8, Ar—H), 2.36 (d, 3H, J=2.4, CH 3 ).
Example 9
Trifluoromethanesulfonic acid 2,3-dimethyl-4-nitrophenyl ester (195JP07)
Trifluoromethanesulfonic anhydride (1.57 mL, 8.77 mmol) was added to 2,3-dimethyl-4-nitrophenol (1.12 g, 6.70 mmol) and triethylamine (2.5 mL, 17.9 mmol) in dichloromethane (40 mL) at 0° C. under Ar atmosphere and the resulting mixture was allowed to stir overnight at r.t. 2M HCl (50 mL) was then added and the solution was extracted with dichloromethane (3×100 mL). The organic extracts were combined, washed with saturated aqueous NaHCO 3 (100 mL), diluted with n-heptane (200 mL), and passed through a pad of silica gel to give 1.96 g (98%) of 195JP07 as a yellow oil.
GC/MS m/z 299 [M] + . 1 H-NMR (CDCl 3 , 300 MHz) δ 7.72 (d, 1H, J=9.0), 7.28 (d, 1H, J=9.0), 2.48 (s, 3H), 2.41 (s, 3H).
Example 10
endo-8-(2,3-Dimethyl-4-nitro-phenyl)-8-azabicyclo[3.2.1]octan-3-ol (195JP08)
195JP07 (793 mg, 2.65 mmol), nortropine (1.01 g, 7.96 mmol), and pyridine (2.5 mL) were heated to 110° C. for 16 h. The crude material was then cooled to r.t., poured into water (200 mL), and extracted with ethyl acetate (3×100 mL). The combined organic extracts were dried (Na 2 SO 4 ), concentrated in vacuo, and the residue purified by preparative TLC (EtOAc/n-heptane, 1:8 as eluent) to give 49.7 mg (6.8%) of 195JP08 as a yellow solid.
R f =0.38 (EtOAc/n-heptane 1:1). LC/MS m/z 277 [M+H] + . 1 H-NMR (CDCl 3 , 300 MHz) δ 7.70 (d, 1H, J=9.0), 6.79 (d, 1H, J=9.0), 4.25 (t, 1H, J=4.5), 3.79 (br s, 2H), 2.47 (s, 3H), 2.49-2.25 (m, 4H) 2.32 (s, 3H), 1.98-1.85 (m, 4H).
Example 11
2-Chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-iodobenzonitrile (195JP18)
Adapting a protocol by Uchiyama et al (J. Am. Chem. Soc., 2002, 124, 8514-8515), which reference is incorporated herein by reference in its entirety, 2-chloro-4-fluorobenzonitrile (311 mg, 2.0 mmol) in dry THF (1.0 mL) was added dropwise to lithium di-t-butyl(2,2,6,6-tetramethylpiperidino)zinncate (4.0 mmol in 10 mL THF, Uchiyama et al J. Am. Chem. Soc., 1999, 121, 3539-3540, which is incorporated herein by reference in its entirety) at 0° C. and stirred at 0° C. for 3.5 h. Iodine (5.08 g, 20.0 mmol) was then added and the reaction was stirred at r.t. overnight. Na 2 S 2 O 3 (1.0 M, 50 mL) and saturated aqueous NH 4 Cl (100 mL) were added, followed by extraction with dichloromethane (3×100 mL), drying of the combined organic layers over Na 2 SO 4 , filtering, and removal of the solvents in vacuo. The residue was passed through a pad of silica gel eluting with EtOAc/n-heptane (1:40), affording 112 mg (0.40 mmol) of 2-chloro-4-fluoro-3-iodobenzonitrile. This material was combined with nortropine (114 mg, 0.90 mmol), K 2 CO 3 (186 mg, 0.134 mol) and DMSO (2.0 mL), and stirred at 130° C. for 1.5 h. The crude mixture thus obtained was diluted with n-heptane (10 mL), passed through a pad of silica gel using EtOAc/n-heptane (1:2), concentrated and purified by preparative TLC (EtOAC/n-heptane, 1:1) to give 1.5 mg (1.7%) of 195JP18 as an off-white solid.
R f =0.21 (EtOAc/n-heptane 1:1). LC/MS m/z 389 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.42 (d, 1H, J=8.6), 6.70 (d, 1H, J=8.6), 4.16 (br s, 1H), 3.95 (br s, 2H), 2.50-2.22 (m, 4H) 1.93-1.78 (m, 4H).
Example 12
3-Bromo-2-chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)benzonitrile (195JP22)
This reaction was carried out identically as in Example 11, using bromine instead of iodine as the electrophile, to afford 4.0 mg (0.5%) of 195JP22 as an off-white solid.
R f =0.34 (EtOAc/n-heptane, 1:1). LC/MS m/z 342 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.39 (d, 1H, J=8.6), 6.74 (d, 1H, J=8.6), 4.15 (t, 1H, J=5.0), 4.02 (br s, 2H), 2.38-2.20 (m, 4H), 1.92-1.79 (m, 4H).
Example 13
2-Bromo-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-5-methyl-benzonitrile (195JP26)
This reaction was carried out identically as in Example 12, using 4-fluoro-3-methylbenzonitrile instead of 2-chloro-4-fluorobenzonitrile as the substrate, to afford 17.6 mg (1.4%) of 195JP26 as an off-white solid.
R f =0.28 (EtOAc/n-heptane 1:1). LC/MS m/z 322 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.29 (s, 1H), 6.92 (s, 1H), 4.12 (t, 1H, J=5.0), 3.82 (br s, 2H), 2.30-2.13 (m, 4H), 2.19 (s, 3H), 1.92-1.72 (m, 4H).
Example 14
endo-8-(2-Chloro-3-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol (196MBT14-B)
To a suspension of 2,3-dichlorotoluene (500 mg, 3.11 mmol) in concentrated sulfuric acid (2.5 mL) was added dropwise a solution of potassium nitrate (314 mg, 3.11 mmol) in concentrated sulfuric acid (2.5 mL) at room temperature. The resulting suspension was stirred 1 hour at room temperature and then poured into ice/water (100 mL) under stirring. The resulting aqueous phase was basified to pH 10 by addition of 25% aqueous ammonia and subsequently extracted with dichloromethane (2×100 mL). The combined organic phases were dried over sodium sulphate, filtered and evaporated. The crude product was purified by preparative TLC (0-100% ethyl acetate in heptane) to give a 4:1 mixture of 6- and 5-nitrated product (232 mg). 80 mg of this mixture was dissolved in pyridine (1 mL). Nortropine (198 mg, 1.553 mmol) was added and the mixture was heated to 110° C. in a sealed flask for 20 hours and then concentrated. The residue was dissolved in 2 M HCl (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated, and the resulting oil was purified by preparative TLC (eluting with dichloromethane) to afford the title compound (35 mg, 14% from 2,3-dichlorotoluene) as a yellow solid.
LC/MS m/z 297 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.76 (d, J=10.5, 1H), 6.80 (d, J=10.5, 1H), 4.24-4.16 (m, 1H), 4.14-4.05 (m, 2H), 2.59 (s, 3H), 2.40-2.25 (m, 4H), 1.97-1.81 (m, 4H), 1.55 (s, 1H).
Example 15
2-Chloro-6-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-nitro-benzaldehyde (196MBT30)
Potassium nitrate (638 mg, 6.31 mmol) was dissolved in concentrated sulfuric acid (4.5 mL) and added dropwise to a stirred solution of 2-chloro-6-fluorobenzaldehyde (1.0 g, 6.31 mmol) at room temperature. The mixture was stirred 1 hour at room temperature and then poured into icewater (100 mL) under stirring. The resulting aqueous phase was basified to pH 10 by addition of 25% aqueous ammonia and subsequently extracted with dichloromethane (2×100 mL). The combined organic phases were dried over sodium sulphate, filtered and evaporated to give 2-chloro-6-fluoro-3-nitrobenzaldehyde (196MBT28-A, 1.16 g, 91%). Regioselectivity was confirmed by 13 C-NMR.
Nortropine (62 mg, 0.491 mmol) and 196MBT28-A (100 mg, 0.491 mmol) were dissolved in pyridine (2 mL) and the mixture shaken in a sealed flask for 2 hours and then concentrated. The residue was dissolved dichloromethane (40 mL) and the organic phase was washed with 2 M HCl (40 mL) followed by 2 M NaOH (40 mL) and finally dried over Na 2 SO 4 , filtered and evaporated. The resulting oil was purified by preparative TLC (0-5% methanol in dichloromethane) to afford 40 mg (26%) of the title compound as a yellow solid.
LC/MS m/z 311 [M+H] + . 1 H-NMR (CDCl 3 ) δ 10.26 (s, 1H), 7.93 (d, J=9.5, 1H), 6.84 (d, J=9.5, 1H), 4.21-4.16 (m, 1H), 4.10-4.01 (m, 2H), 2.40-2.18 (m, 4H), 2.13-1.98 (m, 2H), 1.90-1.82 (m, 2H), 1.47 (s, 1H).
Example 16
endo-8-(3-Chloro-2-hydroxymethyl-4-nitrophenyl)-8-azabicyclo[3.2.1]-octan-3-ol (196MBT32)
196MBT30 (20 mg, 0.064 mmol) was dissolved in methanol (1 mL). Sodium borohydride (3 mg, 0.064 mmol) was added and the mixture was stirred 30 min at room temperature. Saturated aqueous ammonium chloride (1 mL) was added and extracted with dichloromethane (2×10 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated to give 18 mg (90%) of the title compound as a yellow solid.
LC/MS m/z 313 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.80 (d, J=9.0, 1H), 6.82 (d, J=9.0, 1H), 4.86 (d, J=6.5, 2H), 4.24-4.18 (m, 1H), 4.16-4.05 (m, 2H), 3.00 (t, J=6.5, 1H), 2.36-2.22 (m, 4H), 2.00-1.86 (m, 4H), 1.36 (s, 1H).
Example 17
2-Chloro-6-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-nitro-benzaldehyde oxime (196MBT40)
196MBT30 (132 mg, 0.426 mmol) was dissolved in tetrahydrofuran (2 mL). Sodium carbonate (45 mg, 0.426 mmol) was added followed by water (0.5 mL) and hydroxylamine hydrochloride (30 mg, 0.426 mmol). The mixture was stirred 1 hour at room temperature and then concentrated. Dichloromethane (50 mL) was added and the organic phase was washed with 2 M HCl (50 mL) followed by 2 M NaOH (50 mL) and finally dried over Na 2 SO 4 , filtered and evaporated. The resulting residue was purified by preparative TLC (0-5% methanol in dichloromethane) to afford 45 mg (32%) of the title compound as a yellow solid.
LC/MS m/z 326 [M+H] + . 1 H-NMR (MeOD) δ 8.15 (s, 1H), 7.90-6.90 (m, 2H), 4.25-4.00 (m, 3H), 2.35-1.80 (m, 8H).
Example 18
endo-8-(2-Chloro-3-hydroxymethyl-4-nitrophenyl)-8-azabicyclo[3.2.1]-octan-3-ol (196MBT48)
Potassium nitrate (578 mg, 5.71 mmol) was dissolved in concentrated sulfuric acid (4.5 mL) and added dropwise to a stirred solution of 2,3-dichlorobenzaldehyde (1.0 g, 5.71 mmol) at room temperature. The mixture was left without stirring for 10 days at room temperature. Material that had crystallized out of the reaction mixture was collected by filtration to afford 2,3-dichloro-6-nitrobenzaldehyde (196MBT36, 433 mg, 34%) as yellow needles. Regioselectivity was confirmed by the Bayer-Drewson indigo synthesis.
196MBT36 (100 mg, 0.455 mmol) was dissolved in methanol (2 mL). Sodium borohydride (17 mg, 0.455 mmol) was added and the mixture was stirred for 30 minutes at room temperature. Saturated aqueous ammonium chloride (1 mL) was added and extracted with dichloromethane (2×10 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated to give 2,3-dichloro-6-nitrobenzyl alcohol (196MBT46-A, 92 mg, 91%) as a yellow solid.
196MBT46-A (92 mg, 0.418 mmol) and nortropine (53 mg, 0.418 mmol) were dissolved in pyridine (2 mL). The mixture was heated to 110° C. in a sealed flask for 3 days and then concentrated. The red residue was dissolved in 2 M HCl (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated, and the resulting oil was purified by preparative TLC (0-5% methanol in dichloromethane) to afford 1.0 mg (1%) of the title compound as a yellow solid.
LC/MS m/z 313 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.90-6.85 (m, 2H), 5.00-4.97 (m, 2H), 4.26-4.15 (m, 3H), 3.00-2.92 (m, 1H), 2.40-2.30 (m, 4H), 2.00-1.83 (m, 4H), 1.27 (s, 1H).
Example 19
endo-8-(5-Chloro-2-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]octan-3-ol (196MBT6-1)
Nortropine (269 mg, 2.12 mmol) and 4-chloro-2-fluoro-5-nitrotoluene (100 mg, 0.527 mmol) were dissolved in pyridine (2 mL). The mixture was heated to 110° C. in a sealed flask for 20 hours and then concentrated. The residue was dissolved in 2 M HCl (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated, and the resulting oil was purified by preparative TLC (eluting with dichloromethane) to afford 14 mg (9%) of the title compound as a colorless solid.
LC/MS m/z 297 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.86 (s, 1H), 6.75 (s, 1H), 4.17-4.10 (m, 1H), 3.97-3.88 (m, 2H), 2.30-2.10 (m, 7H), 1.96-1.74 (m, 4H), 1.40-1.32 (m, 1H).
Example 20
2-Chloro-4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)benzonitrile (196MBT8-B)
Nortropine (269 mg, 2.12 mmol) and 2-chloro-4-fluorobenzonitrile (100 mg, 0.643 mmol) were dissolved in pyridine (2 mL). The mixture was heated to 110° C. in a sealed flask for 20 hours and then concentrated. The residue was dissolved in 2 M HCl (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated, and the resulting oil was purified by preparative TLC (eluting with dichloromethane) to afford 107 mg (63%) of the title compound as a colorless solid.
LC/MS m/z 263 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.46-6.51 (m, 3H), 4.29-4.16 (m, 2H), 4.16-4.00 (m, 1H), 2.45-2.27 (m, 2H), 2.18-1.96 (m, 4H), 1.79-1.65 (m, 2H), 1.56 (s, 1H).
Example 21
6-Chloro-2-methyl-3-nitrobenzoic acid (198RL35)
2-Chloro-6-methylbenzoic acid (99 mg, 0.58 mmol) was dissolved in conc. hydrochloric acid (1 mL) and cooled in an ice bath. To this solution potassium nitrate in conc. hydrochloric acid (1 mL) was added drop wise. The reaction mixture was stirred for 5 min, then the ice bath was removed and stirring was continued for another 2 hours. The reaction mixture was poured onto ice (25 g) and extracted with ethyl acetate (3×25 mL). The combined organic layers were dried over sodium sulphate, filtered and concentrated in vacuo to give a mixture of the desired 3-nitro (70%) and the 5-nitro (30%) derivatives (118.6 mg, 95%). No effort was made to separate the two isomers, and the mixture was used in the next step.
1 H-NMR (CDCl 3 ) δ 10.53 (br, 1H, CO 2 H), 7.91 (d, 0.7H, J=8.8, Ar—H), 7.85 (d, 0.3H, J=8.4, Ar—H), 7.44 (d, 0.7H, J=8.8, Ar—H), 7.31 (d, 0.3H, J=8.4, Ar—H), 2.59 (s, 2.1H, Ar—CH 3 ), 2.59 (s, 0.9H, Ar—CH 3 ).
Example 22
6-(3-endo-Hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-2-methyl-3-nitrobenzoic acid (198RL39)
6-Chloro-2-methyl-3-nitrobenzoic acid (198RL35, containing 30% of the 5-nitro isomer, 227 mg, 1.05 mmol) and nortropine (536 mg, 4.21 mmol) were dissolved in pyridine (5 mL) and shaken in a vial at 90° C. for 5 days. The reaction mixture was diluted with ethyl acetate (20 mL) and extracted with sodium hydroxide solution (2 M, 3×20 mL). The pH of the combined alkaline layers were regulated to approximately 5 with hydrochloric acid solution (6 M) and extracted with ethyl acetate (3×30 mL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo. The crude product was purified by preparative HPLC to give a yellow solid (154 mg, 48%).
LC/MS m/z 307 [M+H] + . 1 H-NMR (CDCl 3 ) δ 9.90 (br, 1H, CO 2 H), 7.90 (d, 1H, J=9.2, Ar—H), 6.87 (d, 1H, J=9.2, Ar—H), 4.20 (m, 3H, Tr-H), 2.52 (s, 3H, Ar—CH 3 ), 2.40-2.27 (m, 4H, Tr-H), 2.12-2.04 (m, 4H, Tr-H), 1.90 (m, 1H, Tr-OH).
Example 23
endo-8-(2-Hydroxymethyl-3-methyl-4-nitrophenyl)-8-azabicyclo[3.2.1]-octan-3-ol (198RL48-3)
6-(3-endo-Hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-2-methyl-3-nitrobenzoic acid (198RL39, 64 mg, 0.21 mmol) was dissolved in THF (1 mL). This was stirred at 0° C. while borane-THF complex (1 M, 0.35 mL, 0.35 mmol) was added dropwise. After complete addition the mixture was allowed to warm to r.t. and stirring was continued overnight after which LC-MS analysis showed approximately 50% conversion. The reaction was worked up (water/ethyl acetate). The crude product was purified twice by preparative TLC, using ethyl acetate as the mobile phase, to afford the title compound (2.1 mg, 3%).
R f =0.57 (ethyl acetate). LCMS m/z 292 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.75 (d, 1H, J=9.1, Ar—H), 6.85 (d, 1H, J=9.1, Ar—H), 4.89 (s, 2H, Ar—CH 2 OH), 4.21 (m, 1H, Tr-H), 3.95 (m, 2H, Tr-H), 2.57 (s, 3H, Ar—CH 3 ), 2.43-2.25 (m, 4H, Tr-H), 2.14-2.01 (m, 4H, Tr-H).
Example 24
2-Chloro-4-fluoro-3-methyl-1-nitrobenzene (198RL41)
1-Chloro-3-fluoro-2-methylbenzene (1.00 mL, 8.24 mmol) was dissolved in sulfuric acid (18 M, 10 mL) and cooled in an ice bath. Potassium nitrate (0.87 g, 8.65 mmol) dissolved in sulfuric acid (18 M, 10 mL) was added dropwise to the cold solution. The reaction mixture was stirred for 5 min, then the ice bath was removed and stirring was continued for another 2 h. The reaction mixture was poured onto ice (25 g) stirred for 5 min and extracted with ethyl acetate (3×25 mL). The combined organic layers were dried over sodium sulfate, filtered and evaporated to give a clear yellow oil (1.34 g, purity 85%). The product was used without further purification in the next reaction step.
1 H-NMR (CDCl 3 ) δ 7.11 (m, 1H, Ar—H), 7.10 (m, 1H, J=8.3, Ar—H), 2.40 (m, 3H, Ar—CH 3 ).
Example 25
4-(3-endo-hydroxy-8-azabicyclo[3.2.1]oct-8-yl)-3-trifluoromethylbenzo-nitrile (196MBT10-B)
Nortropine (269 mg, 2.12 mmol) and 4-fluoro-3-(trifluoromethyl)benzonitrile (100 mg, 0.529 mmol) were dissolved in pyridine (2 mL). The mixture was heated to 110° C. in a sealed flask for 20 hours and then concentrated. The residue was dissolved in 2 M HCl (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic phases were dried over Na 2 SO 4 , filtered and evaporated, and the resulting oil was purified by preparative TLC (eluting with dichloromethane) to afford 55 mg (35%) of the title compound as a colorless solid.
LCMS m/z 297 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.80-6.85 (m, 3H), 4.15-4.00 (m, 3H), 2.33-2.10 (m, 4H), 2.00-1.84 (m, 2H), 1.82-1.70 (m, 2H), 1.39 (s, 1H).
Example 26
2-Chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile (198RL93)
2-Chloro-4-fluoro-3-methylbenzonitrile (198RL18, 2.48 g, 14.6 mmol), endo-3-exo-methyl-8-azabicyclo[3.2.1]octan-3-ol hydrochloride (197FBA20a, 3.37 g, 19.0 mmol), and potassium carbonate (6.67 g, 48.2 mmol) were dissolved in dimethyl sulphoxide (40 mL), and the mixture stirred under argon at 80° C. for 18 hours. The reaction mixture was poured into water (200 mL) and stirred for 30 min. The off-white solid was filtered off and recrystallised twice from toluene, giving a white powder (1.53 g). The mother liquor was evaporated and the residue recrystallised to yield a second batch of compound (210 mg), giving an overall yield of 40%.
Mp=145-147° C. R f =0.68 (ethyl acetate/dichloromethane 1:1) LC/MS m/z 291 [M+H] + . 1 H-NMR (CDCl 3 ) δ 7.39 (d, 1H, J=8.6, Ar—H), 6.84 (d, 1H, J=8.6, Ar—H), 3.82 (m, 2H, Tr-H), 2.36 (s, 3H, Ar—CH 3 ), 2.32-2.22 (m, 2H, Tr-H), 2.17-1.98 (m, 2H, Tr-H), 1.92-1.77 (m, 4H, Tr-H), 1.26 (s, 3H, Tr-CH 3 ).
Example 27
2-Chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile hydrochloride (198RL26)
The hydrochloride salt was prepared by dissolving 2-chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile (198RL93) in diethyl ether and adding HCl (1.1 eq, 4 M solution in 1,4-dioxane). The mixture was allowed to stir for 15 min and the precipitated salt was filtered off as a fine white powder.
Mp=160° C. (decomposition).
Example 28
2-Chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile mesylate (198RL93-MS)
The mesylate salt was prepared by dissolving 2-chloro-4-(3-endo-hydroxy-3-exo-methyl-8-azabicyclo[3.2.1]oct-8-yl)-3-methylbenzonitrile (198RL93) in diethyl ether and adding methylsulfonate (1.1 eq). The mixture was allowed to stir for 15 min and the precipitated salt was filtered off as a fine white powder.
Mp=164° C. (decomposition).
Example 29
In vitro Determination of Receptor Activity
The functional receptor assay, Receptor Selection and Amplification Technology (R-SAT™), was used with minor modifications from the procedure described previously (Brann, M. R., U.S. Pat. No. 5,707,798, which is hereby incorporated herein by reference in its entirety) to screen compounds for efficacy at the Androgen AR receptor. Briefly, NIH3T3 cells were grown in roller bottles to 70-80% confluence. Cells were then transfected for 12-16 h with plasmid DNAs using Polyfect (Qiagen Inc.) as per the manufacturer's protocol. R-SAT assays were typically performed by transfecting 30 ug/bottle of receptor and 50 ug/bottle of β-galactosidase plasmid DNA. All receptor and helper constructs used were in mammalian expression vectors. Helpers are defined as signaling molecules that modulate both ligand-dependent and/or ligand-independent function of the AR receptor, typically co-activators.
NIH3T3 cells were transfected for 12-16 h, then trypsinized and frozen in DMSO. Frozen cells were later thawed, plated at 10,000-40,000 cells per well of a 96 well plate containing drug. Cells were then grown in a humidified atmosphere with 5% ambient CO 2 for five days. Media was then removed from the plates and marker gene activity was measured by the addition of the β-galactosidase substrate o-nitrophenyl β-D-galactopyranoside (ONPG, in PBS with 5% NP-40). The resulting colorimetric reaction was measured in a spectrophotometric plate reader (Titertek Inc.) at 420 nM. All data were analyzed using the computer program XLFit (IDBSm).
Results for selected compounds are presented in Table 1.
TABLE 1
compound
% Efficacy
pEC50
173FBA73bL
80
8.5
198RL26
79
8.8
165RL90
81
8.7
Example 30
In vivo Activity of Androgen Receptor Agonists
Test compounds of formula I are administered p.o. daily for two weeks to castrated male Sprague Dawley rats (n=3). The effects of the test compounds (1, 3, 10, 30 mg/kg) are compared to testosterone propionate (1 and 3 mg/kg s.c.; positive control) and vehicle (10% Tween80; negative control). Blood and wet weights of prostate gland and seminal vesicle are measured after sacrifice that occurs 24 hours after the last dose. Blood is collected in heparin collection tubes after sacrifice that occurred 24 hours after the last dose. Blood is centrifuged and plasma collected and plasma samples frozen.
Rat luteinizing hormone (LH) plasma levels are determined using an enzyme linked immunoabsorbent assay (ELISA) from Amersham as per manufacturer's instructions. The solid phase assay is based on the competition between unlabeled rLH and a fixed quantity of biotin labelled rLH for a limited amount of rLH specific antibody. A conjugate streptavidin/peroxidase allows for signal amplification and detection in presence of the substrate.
Results for 198RL26
Daily subcutaneous (s.c.) administration of testosterone propionate (TP), at a dose of 1 mg/kg for a period of two weeks, produced significant increases in prostate ( FIG. 1 ), seminal vesicle ( FIG. 2 ), and levator ani muscle ( FIG. 3 ) wet tissue weights as compared to vehicle treatment. In contrast, daily s.c. administration of 3 mg/kg 198RL26 for a period of two weeks did not appear to significantly alter wet tissue weights. Daily administration of higher doses (3 and 10 mg/kg) of 198RL26 appeared to significantly increase wet tissue weights, however, not to the extent of TP. These data suggest, as compared TP, the potential for negative side effects (i.e, increased seminal vesicle and prostate size) with 198RL26 may not be evident until doses of at least 100× of TP are reached. Upon castration, plasma levels of luteinizing hormone (LH) increased by approximately 3-4 fold. ( FIG. 4 ) Chronic administration of TP (1 mg/kg, s.c. for 14 days) restored LH levels to those obtained in naive rats (non-castrated animals). Daily administration of 198RL26 (various doses, p.o. for 14 days) produced a dose-dependent suppression of plasma LH levels, such that a complete reversal was evident at 10 mg/kg.
Although the invention has been described with reference to embodiments and examples, it should be understood that numerous and various modifications can be made without departing from the scope and spirit of the invention.
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Disclosed herein is a novel class of aminophenyl compounds having the structure:
wherein R 1 is cyano or nitro and ring A is a bi- or tricyclic bridged heterocycle and to their use as modulators of androgen receptor for the treatment or prevention of conditions relating thereto.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a protective cover for a pickup truck tailgate and more particularly to a protective cover which protects the rear side of a pickup truck tailgate.
[0003] 2. Description of the Related Art
[0004] Many types of protective covers or “bras” have been previously provided for protecting the front ends of cars and trucks from rock chips, etc. Further, protective covers or shields have also been provided for the protection of the cargo side of a pickup truck tailgate, since the cargo side of the tailgate is exposed to the materials being transported in the truck box such as rocks, lumber, etc. Additionally, protective covers have also been provided to protect the rearward side of the tailgate, since rocks sometimes are thrown from a passing vehicle towards a trailer or the like which is being pulled by the pickup truck with the rocks bounding forwardly from the trailer onto the rear side of the tailgate. Tailgate protective covers, which protect the rear surface of a pickup truck tailgate, are disclosed in Des. Pat. Nos. 433,661 and 323,639. Although the covers of the '661 and '639 patents would appear to protect the tailgates upon which they are mounted, it is believed that those covers are less than convenient to install and will perhaps become inadvertently detached during use.
SUMMARY OF THE INVENTION
[0005] A protective cover for a pickup truck tailgate is disclosed which is designed to be placed adjacent the rear side of the tailgate to prevent flying rocks from chipping the finish of the tailgate. The cover of this invention comprises a generally rectangular, flexible plastic and/or fabric cover member having a rear side, a front side, an upper end, a lower end, and opposite side edges. An elongated, J-shaped channel member is secured to the lower end of the cover member and extends between the side edges thereof. An elongated strip of the hooked portion of a hook-and-loop fastener is secured to the upper front end of the cover member and which extends between the side edges of the cover member. The lower end of the protective cover is secured to the tailgate by attaching the J-shaped channel member to the lower end of the tailgate. The upper end of the protective cover is secured to the tailgate by securing the strip of the hooked portion of the hook-and-loop fastener to a strip of the looped portion of the hook-and-loop fastener which is secured to the upper forward end of the tailgate.
[0006] It is therefore a principal object of the invention to provide a protective cover for the rearward side of a pickup truck tailgate.
[0007] A further object of the invention is to provide a protective cover for the rearward side of a pickup truck tailgate which is conveniently attached to the tailgate.
[0008] A further object of the invention is to provide a protective cover for the rearward side of a pickup truck tailgate which will not become detached during use.
[0009] A further object of the invention is to provide a protective cover for the rearward side of a pickup truck tailgate which economical of manufacture, durable in use and refined in appearance.
[0010] These and other objects will be apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a rear perspective view of the protective cover of this invention mounted on a pickup truck tailgate;
[0012] [0012]FIG. 2 is a front perspective view of the protective cover;
[0013] [0013]FIG. 3 is a front perspective view of the tailgate and the cover; and
[0014] [0014]FIG. 4 is a sectional view illustrating the protective cover mounted on the tailgate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The numeral 10 refers to a conventional pickup truck having a truck bed 12 and a tailgate 14 . Tailgate 14 includes a cargo side 16 , rear side 18 , upper end 20 , lower end 22 , and opposite side edges 24 and 26 . Tailgate 14 is provided with a conventional rearwardly presented handle 28 mounted thereon for opening the tailgate 14 . Normally, most tailgates have a lip or flange 29 at the lower end thereof which extends downwardly from the lower rearward end thereof.
[0016] The protective cover of this invention is referred to by the reference numeral 30 and is preferably constructed of a flexible plastic material or a flexible fabric material such as used on protective covers fitted to the front of vehicles to protect the same. Cover 30 includes an interior or front surface 32 , exterior or rear surface 34 , an upper end 36 , a lower end 38 , and opposite side edges 40 and 42 . Cover 30 is provided with an elongated opening 43 formed therein adapted to register with the tailgate handle 28 when cover 30 is mounted on the tailgate 14 . An elongated strip 44 of the hooked portion of a hook-and-loop fastener material such as Velcro™ or the like is secured to the front surface 32 of cover 30 at the upper interior end thereof. In the preferred embodiment, an elongated J-shaped channel member 46 , comprised of plastic or the like, is secured to the lower end of the cover 30 . For purposes of description, channel member 46 will be described as including leg portion 48 , base portion 50 which may either be curved or flat, and leg portion 52 . Leg portion 48 is secured to the lower end of the cover 30 by stitching, adhesive, etc., as seen in FIG. 4. When secured to the cover 30 , as seen in FIG. 4, the leg portion 52 is spaced forwardly of cover 30 to provide a space 54 between leg portion 52 and cover 30 . Space 54 is provided so as to be able to receive the lip 29 of the tailgate 14 when the cover is secured to the tailgate 14 . As seen, channel member 46 has outer end portions 56 and 58 , respectively, which receive the lower ends of side edges 40 and 42 , respectively, of cover 30 for strengthening or reinforcing purposes. The upper inner end of tailgate 14 has an elongated strip 60 of the looped portion of a hook-and-loop fastener material such as Velcro or the like secured thereto.
[0017] When it is desired to mount the protective cover 30 on the tailgate 14 to protect the rearward side thereof, the cover 30 is positioned adjacent the rear side of tailgate 14 with the front surface 32 of the cover 30 being adjacent the rear side of tailgate 14 , as seen in FIG. 3. The J-shaped channel member 46 is then secured to the lip 29 at the lower end of tailgate 14 so that lip 29 is received in space 54 . The upper end 36 of cover 30 is then drawn over the upper end 20 of tailgate 14 so that strip 60 may be secured to strip 44 thereby securely mounting the cover 30 on tailgate 14 to protect the rearward surface thereof. When the cover 30 is positioned on the tailgate 14 , the opening 43 of cover 30 registers with the tailgate handle 28 to provide convenient access thereto.
[0018] The fact that the upper end 36 folds over the upper end 20 of tailgate 14 , as seen in FIG. 4, reduces the possibility that wind could inadvertently blow the cover 30 from the tailgate 14 . Although the J-shaped channel member 46 is the preferred method of securing the lower end of the cover 30 to the lower end of the tailgate 14 , a strip of the hooked portion of a hook-and-loop material could be secured to the lower end of tailgate 14 and a strip of the looped portion of a hook-and-loop material could be secured to the lower front side of cover 30 for engagement with the hooked strip on the lower end of tailgate 14 . Further, in some cases, the opening 43 may be omitted if the tailgate does not have a tailgate handle at its rear side.
[0019] Although it is preferred that strips 44 and 60 extend continuously across the widths of cover 30 and tailgate 14 , spaced-apart strips 44 and spaced-apart strips 60 could be utilized. Further, while strip 44 has been described as being hooked and strip 60 has been described as being looped, strip 44 could be looped and strip 60 could be hooked.
[0020] Additionally, although it is preferred that the J-shaped channel member 46 extend continuously across the lower end of cover 30 , a plurality of spaced-apart J-shaped channel members could be secured to the lower end of cover 30 . However, it is believed that the use of a continuous J-shaped channel member improves the appearance of the cover and lessens the likelihood that the lower end of the cover will inadvertently become disconnected from the tailgate. Further, while the J-shape of the channel member 46 is the preferred shape, it is possible that a U-shaped channel member could be substituted therefore. It is believed that the J-shape enhances the attachment of the channel member to the cover 30 .
[0021] Thus it can be seen that the invention accomplishes at least all of its stated objectives.
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A protective cover is disclosed which is positioned adjacent the rear side of a pickup truck tailgate to protect the same from rock chips, etc. The lower end of the cover is removably attached to the lower end of the tailgate. The upper end of the cover is removably attached to the upper end of the tailgate.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application Serial No. 101 14 845.3, filed Mar. 24, 2001, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates, in general, to a clutch release bearing, and more particularly to a clutch release bearing for use in a clutch mechanism for motor vehicles.
[0003] A clutch release bearing is typically intended for actuation of a clutch mechanism, e.g. separating clutch, disposed between the internal combustion engine and a gearbox, and is configured as a tapered roller bearing which includes a revolving outer bearing ring, a non-rotatable inner bearing ring, and rolling members, received in a cage and guided between the bearing rings. Supported against the outer ring is an adjustment ring, which establishes a connection between a disk spring of the clutch mechanism and the release bearing, whereby the disk spring bears directly on a skirt of the outer ring at the side of the adjustment ring confronting the clutch mechanism. The adjustment ring is configured to allow a relative movement of the adjustment ring and the outer ring so as to implement a self-adjusting or self-aligning release bearing.
[0004] Such a release bearing is able to compensate shocks generated by axial misalignment with the disk spring that is connected directly to the clutch mechanism. The axial shocks, caused by the disk spring and reinforced by the operation of the internal combustion engine, increase wear and thus reduce the service life of the release bearing.
[0005] German Pat. No. 199 12 432 A1 describes a release bearing with a revolving outer ring for direct support of an adjustment ring. In their contact zone, the outer ring and the adjustment ring have complementary calotte-shaped segments to allow a relative movement. The outer ring of the release bearing as well as the adjustment ring are made of steel. As a consequence, rust formation caused by friction can be experienced, resulting in greater wear. High wear results in annoying noise and triggers the so-called clutch judder that adversely affects the overall riding comfort, so that the service life of these release bearings is insufficient to meet the demands by vehicle manufactures.
[0006] It would therefore be desirable and advantageous to provide an improved release bearing, which obviates prior art shortcomings and which exhibits a long service life, is maintenance-free and inhibits noise while still being reliable in operation and cost-efficient to produce.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the present invention, a release bearing includes a rolling-contact bearing having a non-rotatable inner ring, a rotating outer ring, and plural rolling members located between the inner and outer rings; an adjustment ring having a ring flange for abutment against a disk spring of a clutch mechanism; and a sliding element made of bearing material and disposed in a support zone, which is defined between complementary calotte-shaped portions of the outer ring and the adjustment ring so that the adjustment ring and the outer ring are movable relative to one another for effecting a self-adjustment of the release bearing.
[0008] The present invention resolves prior art problems by providing a sliding element in the support zone or contact zone between the adjustment ring and the revolving outer ring of the release bearing. The sliding element is suitably made of a bearing material or appropriate friction-reducing and wear-resistant material which is maintenance-free to ensure a long service life. As a result of the reduction in friction, the self-adjusting feature of the components, outer ring and adjustment ring, is significantly improved. The optimized self-adjustment is further able to significantly dampen the axial shocks transmitted via the clutch mechanism into the release bearing. The provision of a sliding element eliminates a direct contact of the steel parts, adjustment ring and outer ring, and this prevents friction-based rust formation. By sandwiching the sliding element in the support zone between the outer ring and adjustment ring, the latter components are effectively decoupled from one another so that noise development is suppressed. A direct contact of the adjustment ring upon the outer ring is suitably avoided to thereby ensure a maintenance-free, low friction and sat the same time damping self-adjustment between the mutually moving components, adjustment ring and outer ring. The sliding element can be connected to either one of the carriers, i.e. outer ring or adjustment ring, without requiring any modification of the carrier that is selected to bear against the sliding element, so that existing installation space can be used. Support of the adjustment ring on the outer ring permanently eliminates friction-based rust formation.
[0009] It is to be understood by persons skilled in the art that the term “carrier” used in the description to refer to the outer ring or to the adjustment ring of the release bearing.
[0010] Wear of the spherical or calotte-shaped portions in the support zone between the sliding element and the outer ring or adjustment ring is significantly reduced compared to conventional self-adjusting release bearings. Moreover, clutch judder is effectively prevented which has a positive effect to reduce noise development. A sliding element according to the present invention can be fabricated in great numbers and does not require special handling for installation or securement to the adjustment ring or outer ring of the release bearing.
[0011] According to one embodiment of the present invention, the sliding element may be connected to the outer ring of the release bearing. A largest possible contact surface can be realized, when the sliding element embraces the entire side of the outer ring and is extended to an area shy of the contour of the non-rotatable inner ring at formation of a slight annular gap. In this way, the rotating outer ring can be optimized with respect to size and weight and may have a width which is substantially limited to the provision of a suitable raceway for the rolling members. At the same time, the sliding element ensures on the side confronting the adjustment ring a large contact zone or enlarged support zone for the adjustment ring. Thus, a sufficiently large contact zone or support zone between the mutually movable components is realized even at extremely tilted positions. As an alternative, the sliding element may also be connected directly to the adjustment ring to form a unitary structure which has calotte-shaped portions to complement the outer contour of the rotating outer ring of the release bearing. In either case, the large-area contact of the sliding element upon the adjustment ring or outer ring results in a sufficient support in each and every position, i.e., also when the adjustment ring occupies an extremely tilted disposition. At the same time, the large-area contact of the sliding element ensures a reduced surface pressure so that the strength and rigidity of the sliding element is not adversely affected.
[0012] According to another feature of the present invention, the sliding element may also be configured in segments, instead of a continuous contact, for resting upon the outer ring or adjustment ring. In this way, the adhesion of the sliding element is improved because tension as a consequence of different coefficients of thermal expansion between the different materials of the adjustment ring or outer ring, and the sliding element is effectively eliminated. Of course, the sliding element may also be configured with a longitude slot or groove, which coincides with the symmetry axis, in order to compensate varying coefficients of thermal expansion. Instead of one slot or groove, also several slots or grooves may be provided about the circumference of the sliding element and formed alternately on the inside or outside of the sliding element or extend through the wall of the sliding element. Any suitable configuration of the slot or slots is conceivable, i.e., straight, meander-shaped or slanted.
[0013] The production costs for making a sliding element according to the present invention can be reduced, when employing an injection molding process. This process can also be used to incorporate in a single step the slots and grooves in the sliding element for compensation of varying coefficients of thermal expansion.
[0014] Regardless of its configuration, the sliding element may be positively secured to either one of the carriers, i.e. outer ring or the adjustment ring of the release bearing. Suitably, the surface of the carrier may be formed with grooves for engagement or guidance of projections of the sliding element. As a result, the sliding element is also secured against rotation with respect to the carrier. As an alternative or in addition to the positive securement, the sliding element may also be urged into forced engagement with the carrier, for example, through gluing. An example of a suitable glue includes a high-temperature adhesive. Gluing of the sliding element ensures also a compensation of even small unevenness between the carrier and the sliding element so as to prevent the formation of voids which are detrimental to a secure attachment of the sliding element.
[0015] According to another feature of the present invention, the sliding element may be formed by a coating applied directly through injection onto the outer ring or adjustment ring. In this way, diametrical tolerances of the mating components, outer ring and adjustment ring, that may influence the structural length, are eliminated. Suitably, the carrier may include in the contact zone with the sliding element a circumferential crease or groove, which is filled by the material of the sliding element during injection molding, to realize an effective positive securement of the sliding element to the carrier and to prevent a rotation. Stress through shrinkage during injection molding can be counteracted in a controlled manner, by providing the outer ring or the adjustment ring in the support zone with at least one axis-parallel or helical notch. To prevent a rotation of the parts, a groove is provided in diametric opposition to the notch at the diameter and/or in the plane surface of the adjustment ring or outer ring and can also be filled with sliding element material during injection molding.
[0016] The sliding element, on the one hand, and the outer ring or the adjustment ring, on the other hand, may be made of different materials. The material for the sliding element is selected by taking into account optimum wear properties and friction properties as well as inexpensive fabrication and mounting to the outer ring or adjustment ring. The carrier, outer ring or adjustment ring, is suitably made of steel. The configuration of the carrier allows hereby a production without material removal, in particular a deep-drawing process that enables a production of the adjustment ring as well as of the outer ring on a large scale in a cost-efficient manner. To realize sufficient strength, especially wear-resistance, the adjustment ring as well as the outer ring may be heat-treated at least in those zones that are subject to high loads, such as the calotte-shaped segments, tracks for the rolling members, as well as the contact surface for support of the disk spring of the clutch mechanism.
[0017] The sliding element may suitably be made of a high-strength and wear-resistant plastic, such as thermoplastic material or a duroplastic material. The sliding element may include additives such as carbon fibers, MoS 2 fractions, and/or epoxy resins, alone or in combination, for realizing a lubrication and/or improved service life, when the sliding element is based on duroplastic material. The use of duroplastic material significantly enhances the useful life of the sliding element, without adversely affecting the manufacturing costs. The sliding element may also be made of PPA or PA46 combined with carbon fibers as wear-reducing agent and PTFE as friction-reducing agent. Its may also be conceivable to make the sliding element of ceramic material. This ceramic material, also called industrial ceramic, exhibits optimal wear-resistance and is therefore suitable for use with a contact surface that is subject to severe conditions and soiling during operation of the release bearing.
[0018] Persons skilled in the art will understand, that the foregoing description of materials for the sliding element is not exhaustive but only illustrative, because other materials or material combinations may be conceivable as well so long as they generally follow the concepts outlined here, i.e. exhibit sufficient friction properties and wear-resistance and can be shaped appropriately and manufactured in a cost-efficient manner.
[0019] The adjustment ring may be made by a deep-drawing process and is suitably made of steel C80M which subsequently can be hardened through heat-treatment to realize an improved wear resistance.
[0020] According to another embodiment of the present invention that optimizes the number of used components includes an adjustment ring which is supported directly by the outer ring. Hereby, these structural parts form in a contact zone or support zone complementary calotte-shaped portions. An adjustment ring of this type can then suitably combined with a sliding element made from a duroplastic material by an injection tool drawn in axial direction to provide a N-section profile. The use of duroplastic material is advantageous here because of its sufficient strength and shape stability. The sliding element may be secured to the ring flange through gluing, in combination with protrusions of the sliding element for positive engagement in respective recesses of the ring flange.
[0021] According to another feature of the present invention, the adjustment ring may also be so configured that its components, ring flange and sliding element, are made of same material. For example, the adjustment ring may be made of ceramic material or duroplastic material. The components of the adjustment ring may be glued for realizing a permanent connection. Gluing may be assisted by a positive connection in which the sliding element is connected to the ring flange via a crown gearing and/or spline profiles or the like, whereby a greater contact surface is realized at the same time. In addition, the adjustment ring is secured against rotation and the bonding of the parts is improved. Excess glue can be accumulated in depressions or notches formed on at least one bonded surface of the mating annular regions being joined.
[0022] According to another feature of the present invention, that optimizes the number of used components includes a single-piece adjustment ring which is made exclusively of duroplastic material or ceramic and combined with the release bearing. An adjustment ring of this type corresponds also to an assembled adjustment ring, which has components made of same material.
[0023] According to another feature of the present invention, the release bearing may include a captivating mechanism by which all components of the release bearing are captivated after mounting and installation. Hereby, the rotating outer ring is provided with a sleeve or clip which extends axially over a contact zone of the adjustment ring with the outer ring. The sleeve or the clip is hereby spaced from the adjustment ring and guided while maintaining an annular gap. An end portion of the sleeve projects behind a marginal area, so that the release bearing including the adjustment ring is captivated to form a unitary structure.
[0024] According to another feature of the present invention, the calotte-shaped portions of the outer ring and the adjustment ring are disposed at an angle of ≧15° to an axis of symmetry of the release bearing. Suitably, the sliding element and the outer ring or the adjustment ring have a radius of ≧30 mm in an area of the support zone.
BRIEF DESCRIPTION OF THE DRAWING
[0025] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
[0026] [0026]FIG. 1 is a half-section of a release bearing according to the present invention for interaction with an adjustment ring, with a sliding element embracing a rotating outer ring for support of the adjustment ring;
[0027] [0027]FIG. 2 is a half-section of a modified release bearing according to the present invention, showing the sliding element snapped to the outer ring;
[0028] [0028]FIG. 3 is a half-section of another variation of a release bearing according to the present invention, incorporating a captivating mechanism;
[0029] [0029]FIG. 4 is a half-section of still another variation of a release bearing according to the present invention, which used a sliding element for implementing a captivating mechanism for the adjustment ring;
[0030] [0030]FIG. 5 is a half-section of still another variation of a release bearing according to the present invention, incorporating yet another modified captivating mechanism;
[0031] [0031]FIG. 6 is a half-section of still another variation of a release bearing according to the present invention;
[0032] [0032]FIG. 7 is a sectional view of a release bearing according to the present invention, in which the outer ring has secured thereto the sliding element and a captivating mechanism; and
[0033] [0033]FIG. 8 is a sectional view of another variation of a release bearing according to the present invention, in which the adjustment ring includes a sliding element.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.
[0035] Turning now to the drawing, and in particular to FIG. 1, there is shown a half-section of a release bearing, generally designated by reference numeral 1 and defined by a symmetry axis 10 . The release bearing 1 is mounted on a guide sleeve 50 , positioned in concentric surrounding relationship to a driveshaft, not shown, which connects an internal combustion engine to a gearbox. The release bearing 1 is configured in the form of a tapered roller bearing and includes a non-rotatable inner ring 2 , a rotating outer ring 3 and a plurality of rolling members 4 positioned between the inner ring 2 and the outer ring 3 . Surrounding the outer ring 3 on the outside is a sliding element 5 , the outside of which supports an adjustment ring 6 to prevent a direct contact between the outer ring 3 and the adjustment ring 6 in a support zone 7 . In order to enable a self-adjustment of the release bearing 1 with respect to the adjustment ring 6 , the directly supporting components, the outer ring 13 and the adjustment ring 6 , have complementary calotte-shaped configuration in the support zone 7 . As indicated in FIG. 1, the support zone 7 extends with respect to the symmetry axis 10 of the release bearing 1 at an angle α of ≧15°. Reference character R denotes the radius of the support zone 7 , i.e., the sliding element 5 and the outer ring 3 have a radius R of ≧30 mm in the area of the support zone 7 .
[0036] The adjustment ring 6 has a substantially disk-shaped configuration and supports a disk spring 11 which is connected directly or indirectly with the clutch mechanism. FIG. 1 shows the adjustment ring 6 in a neutral position as well as in both extreme tilting positions, shown in broken and dashdot lines, respectively, and referring to positions in which the adjustment ring 6 is tilted relative to the outer ring 3 .
[0037] On its side confronting the adjustment ring 6 , the sliding element 5 includes a leg portion 12 which is formed with a collar 13 extending axially inwardly in the direction of the rolling members 4 to terminate shy of the inner ring 2 at formation of an annular gap. A shielding plate 14 of sheet metal is mounted form-fittingly to the leg portion distal end of the sliding element 5 and extends toward the inner ring 2 to terminate just shy thereof to define an annular gap therebetween. The collar 13 of the sliding element 5 and the shielding plate 14 seal together an interior space of the release bearing 1 on both sides of the rolling members 4 . The release bearing 1 further includes a captivating mechanism, generally designated by reference numeral 15 and including a sheet metal holder or clip 16 which is securely fixed to the inner ring 2 . The clip 16 has a substantially cylindrical configuration and extends axially beyond the support zone 7 between the sliding element 5 and the outer ring 3 . The clip 16 has an end portion 19 which is bent inwardly to radially overlap an end portion 18 of the adjustment ring 6 .
[0038] Turning now to FIGS. 2 to 8 , there are shown releases bearings of substantially similar configuration as the release bearing 1 of FIG. 1 so that parts corresponding with those in FIG. 1 are denoted by identical reference numerals and not explained again. In describing the following Figures, like parts of the release bearing 1 , in particular the sliding element 5 , will be identified by corresponding reference numerals followed by a distinguishing lower case character.
[0039] [0039]FIG. 2 shows a release bearing 1 a which differs from the release bearing 1 of FIG. 1 in that the outer ring 3 a is secured form-fittingly to the sliding element 5 a . Hereby, the sliding element 5 a is provided on the side distal to the adjustment ring 6 with a retaining lug 19 which snaps onto an end face of the outer ring 3 , when installed.
[0040] The release bearing 1 b according to FIG. 3 includes a sliding element 5 b which, like in the embodiment of FIG. 1, is mounted by the shielding plate 14 to the outer ring 3 but includes in addition an axially compressed seal 42 for better sealing action. The captivating mechanism 15 b of the release bearing 1 b is implemented by providing a clip 16 b which has a substantially U-shaped configuration and includes an inner leg 22 which is secured to an axially projecting portion of the inner ring 2 b . Extending the inner leg 22 is a radial portion 21 which covers a confronting end face of the release bearing 1 b . An outer leg 23 of the clip 16 b extends axially above the support zone 7 between the adjustment ring 6 and the sliding element 5 b . Hereby, an end portion of the leg 23 is bent inwardly to partially overlap the adjustment ring 6 .
[0041] The release bearing 1 c according to FIG. 4 includes a sliding element 5 c which is so configured as to form an outer slot 24 in substantial parallel relationship to the support zone 7 for engagement of an end portion 18 of the adjustment ring 6 . A slot-bounding outer wall portion 25 of the sliding element 5 c extends at a distance to the end portion 18 of the adjustment ring 6 to realize a radial overlap and thereby implement a captivating mechanism 15 c . The sliding element 5 c has a groove 41 which faces the outer ring 3 and is provided to compensate tension as a result of different coefficients of thermal expansion between the materials of the sealing elemtn 5 a and the outer ring 3 . In addition, the groove 41 can be used for receiving lubricant and/or wearing particles.
[0042] The release bearing 1 d according to FIG. 5 includes a captivating mechanism 15 d in the form of a clip 16 d shaped from sheet metal and comparable to the clip 16 b of FIG. 3. The clip 16 d includes an inner substantially Z-shaped retaining member 27 , which is secured to the inner ring 2 b , and an angle 28 , which connects to the retaining member 27 and screens with a radial portion an end face of the release bearing 1 d . The angle 28 terminates in an outer cylindrical leg 29 which extends axially above the support zone 7 between the adjustment ring 6 and the outer ring 3 . The leg 29 has an end portion 30 which is bent inwardly and terminates in an outwardly arched end to permit a desired radial deflection during installation of the adjustment ring 6 and thus to simplify the assembly.
[0043] The release bearing 1 e according to FIG. 6 includes a sealing element 5 d , which corresponds substantially to the configuration shown in FIG. 4, and includes slot 24 for realizing the captivating mechanism 15 c . In addition, the sliding element 5 e is provided on its side distal to the slot 24 with an axial prolongation 31 which terminates with a circumferential or segmental retention nose 32 in radially inward direction. When installed, the retention nose 32 latches on to a shoulder 33 of a disk-like sealing element 34 which has an angled configuration. The sealing element 34 surrounds, axially limited, the outside of the outer ring 3 and extends in radial direction towards the inner ring 2 b at formation of an annular gap 35 .
[0044] The release bearing 1 f according to FIG. 7 includes an outer ring 3 f and a sliding element 5 f , whereby the outer ring 3 f is formed on its end distal to the sliding element 5 f with a radially outwardly directed step 36 for support of a ring-shaped clip 16 f which is surrounded on the outside by a sheet metal sleeve 39 . The sleeve 39 embraces the outside of the release bearing 1 f to form on one end the captivating mechanism 15 f by means of an inwardly bent end portion 17 . On the other end 43 , the sleeve 39 secures form-fittingly the shielding plate 14 which is disposed on the outer ring 3 f to provide a sealing action of the interior space of the release bearing 1 f for the rolling members 4 and extends radially toward the inner ring 2 b . The sleeve 39 is formed with a circumferential depression 39 for securing the sleeve 39 to the clip 16 f . Once the assembly is completed, the end 43 of the sleeve 39 is bent inwardly to unite all components of the release bearing 1 f to form a captivated unitary structure. A sealing mass 44 may be incorporated in an axial ring space bounded by the shielding plate 14 and the clip 16 f for realizing an improved sealing o the sleeve 39 and the outer ring 3 b . A suitable material for the sealing mass 44 may be silicone or acryl.
[0045] The release bearing 1 g according to FIG. 8 includes a single-piece adjustment ring 6 g which is supported by the outer ring 3 g in the support zone 7 in form-fitting manner. The component-optimized release bearing 1 g includes a clip 16 g designed as a multi-function component which assumes the function of a shielding plate and a seal between the outer ring 3 g and the inner ring 2 g , on the one hand, and provides a captivating mechanism 15 g by having an outer leg which extends in axial direction up to an area above the support zone 7 and has one end to radially overlap an end portion 18 of the adjustment ring 6 b.
[0046] Regardless of its configuration, the sliding element may be formed by a coating applied directly through injection onto the outer ring. In this way, diametrical tolerances of the mating components, outer ring and adjustment ring, that may influence the structural length, are eliminated.
[0047] While the invention has been illustrated and described as embodied in a self-adjusting clutch release bearing, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
[0048] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents:
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A release bearing includes a rolling-contact bearing having a non-rotatable inner ring, a rotating outer ring, and plural rolling members located between the inner and outer rings, An adjustment ring having a ring flange is provided for abutment against a disk spring of a clutch mechanism, and a sliding element made of bearing material is disposed in a support zone defined between complementary calotte-shaped portions of the outer ring and the adjustment ring so that the adjustment ring and the outer ring are movable relative to one another for effecting a self-adjustment of the release bearing.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of and an apparatus for releasing a cut-through connection.
[0002] Network services provided for data transmission can be classified into a connection type and a connection-less type.
[0003] In the connection-type network service, communication data is transmitted through a communication channel which has been established exclusively between a sender terminal and a receiver terminal according to a telephone number, for example, designated by the sender terminal.
[0004] On the other hand, communication data is transmitted being divided into packets, such as IP (Internet Protocol) packets, each added with a header having destination information, in the connection-less-type network service. The packet received by a node of the network is relayed to a next node retrieved by referring to routing information prepared in the node according to the destination information described in the header. Being thus relayed node by node, each packet finally arrives to a destination node which accommodates the receiver terminal of the packet.
[0005] In the connection-less-type network service, communication channels between the sender terminal and the receiver terminal can be shared by packets having various destinations, enabling a good use of the network resources.
[0006] However, in view of transmission speed, the connection-type network service is advantageous, and substantially the same efficiency of the network resources can be obtained even in the connection-type network service when there are many packets to be transmitted continuously from a specific sender terminal to a specific receiver terminal.
[0007] Recently, a network node device called the IP switch is developed, wherein an ATM (Asynchronous Transfer Mode) switch is employed together with an IP controller which takes charge of routing the IP packets by controlling the ATM switch.
[0008] In the IP switch, continuous flows of IP packets, such as a flow of multi-media data or burst data, are taken in consideration, and a VC (Virtual Channel) is assigned to each distinct continuous flow of the IP packets, so that ATM cells of the concerning flows can be relayed promptly by way of “cell-switching”, that is, can be relayed directly by the ATM switch without reassembled into packet data.
[0009] In the IP switch, ATM cells of the IP packet arrived to the node for the first of each continuous flow are reassembled into packet data and transferred to the IP controller. When the IP packet is detected by the IP controller to belong to an continuous flow, such as a flow according to the FTP (File Transfer Protocol) or the HTTP (Hyper Text Transfer Protocol), a VC connection exclusively assigned to the flow is established in the ATM switch for performing a high-speed switching of the ATM cells of the flow, at the cell-level without passing the IP controller. This connection is called the cut-through connection.
[0010] The cut-through connection should be released when the concerning flow has been over, that is, when it is detected that any ATM cell of the concerning flow does not arrive for a predetermined time period.
[0011] Besides the IP switch, several network node devices, such as those called the LANE (LAN Emulation over ATM), the MPOA (Multi-Protocol Over ATM) or the IPOA (IP Over ATM), are proposed or developed in the ATM Forum or the IETF (Internet Engineering Task Force) by integrating the ATM and the IP technology.
[0012] In these network node devices, also, the cut-through connection is established for each continuous flow of the packet traffic, similarly to the IP switch, and established cut-through connections are monitored always individually for releasing them in the absence of their traffic for a certain time period.
[0013] For detecting the absence of the packet arrival for a certain period, a traffic monitoring means, which is realized conventionally with software and cell counters for counting cell arrivals on each cut-through connection, has been provided in any of the IP switch, the LANE, the MPOA and the IPOA.
[0014] [0014]FIG. 5 is a block diagram illustrating a configuration example of a conventional traffic monitoring means for detecting the absence of the cell arrival, and FIG. 6 is a flowchart illustrating operational steps performed in the software for controlling the monitoring means of FIG. 5.
[0015] A cell detecting unit 41 detects passage of ATM cells of each cut-through connection, which is notified to a cell counter 42 and the count value of the cell counter 42 is incremented by one with passage of one ATM cell.
[0016] In the software implemented in the IP controller, for example, initialization is performed (at step S 20 of FIG. 6) when a cut-through connection is newly established. A register A for storing the preceding count value of the cell counter 42 and a soft counter, both provided in the software, are reset to ‘0’, together with the cell counter 42 , and a timing clock, which indicates a timing periodically to read out the cell counter 42 , is started.
[0017] Every time the timing to read out the cell counter 42 arrives (YES at step S 21 ), the count value of the cell counter 42 is read out (at step S 22 ) and compared to the preceding count value of the cell counter 42 stored in the register A (at step S 23 ).
[0018] When the count value is not equal to the preceding value, it means that at least one ATM cell of the cut-through connection is arrived and so, the concerning traffic is determined to be flowing normally. The preceding value stored in the register A is revised with the count value newly read out (at step S 24 ), and the operational step returns to S 21 for repeating steps S 21 to S 24 .
[0019] When the count value of the cell counter 42 is detected to be equal to the preceding value (at step S 23 ), the software counter is incremented by one (at step S 25 ) as no ATM cell has arrived from the preceding read-out timing. Until the software counter counts a threshold value, the operational steps S 21 to S 26 are repeated. When the count value of the software counter attains to the threshold value, it is determined (at step S 27 ) that the traffic of the corresponding cut-through connection has terminated, and the concerning cut-through connection is released.
[0020] However, a problem of the conventional traffic monitoring means as above described is that there must be performed many software processings, such as reading out the cell counter 42 (step S 22 ), comparing the count value to the preceding value (steps S 23 and S 24 ), or revising the software counter (step S 25 ). Therefore, when the number of established cut-through connections becomes large, load of the software to be executed in the IP controller, for example, becomes too much increased.
[0021] Another problem of the conventional traffic monitoring means is that a large memory space is required because the software counter and the register A should be provided for each cut-through connection.
SUMMARY OF THE INVENTION
[0022] Therefore, a primary object of the present invention is to provide a method of and an apparatus for releasing a cut-through connection which is applicable to such network node devices and able to reduce load to be charged on software processings.
[0023] In order to achieve the object, in an apparatus according to an aspect of the invention for releasing a cut-through connection in a network node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node, there are comprised:
[0024] a timer having a time counter assigned to the cut-through connection and outputting a time-out notification signal when a count value of the time counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the time counter being incremented along with time passage and being reset when the cut-through connection is established and when a cell of the cut-through connection arrives to the network node;
[0025] a time-out threshold memory wherein the time-out threshold value is registered;
[0026] a connection-release control unit for controlling a cell processing unit to release the cut-through connection according to the time-out notification signal; and
[0027] a connection-release message generator for transmitting a connection-release requesting message of the cut-through connection towards a next node according to the time-out notification signal.
[0028] Therefore, the load to the control software for detecting traffic termination of the cut-through connections can be far reduced according to the invention in comparison with the conventional method.
[0029] An apparatus according to a second aspect of the invention comprises:
[0030] a timer having an up/down counter assigned to the cut-through connection and outputting a time-out notification signal when a count value of the up/down counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the up/down counter being reset when the cut-through connection is established, being incremented according to clock pulses having a cell cycle predetermined for the cut-through connection and being decremented when a cell of the cut-through connection arrives to the network node;
[0031] a time-out threshold memory wherein the time-out threshold value is registered;
[0032] a cycle-clock generator for generating the clock pulses referring to a value of the cell cycle which is registered in a cell-cycle memory corresponding to the cut-through connection;
[0033] a connection-release control unit for controlling a cell processing unit to releasing the cut-through connection according to the time-out notification signal; and
[0034] a connection-release message generator for transmitting a connection-release requesting message of the cut-through connection towards a next node according to the time-out notification signal.
[0035] According to the second aspect, the time-out notification signal can be generated even when the average cell arrival cycle of a cut-through connection remains longer than a predetermined cell cycle for a certain time period. Therefore, also the cut-through connection whereof cell traffic has become too small can be released efficiently.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The foregoing, further objects, features, and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawings wherein the same numerals indicate the same or the corresponding parts.
[0037] In the drawings:
[0038] [0038]FIG. 1 is a block diagram illustrating a connection releasing circuit according to an embodiment of the invention;
[0039] [0039]FIG. 2 is a block diagram illustrating inner configuration of a traffic monitoring unit 2 of FIG. 1;
[0040] [0040]FIG. 3 is a flowchart illustrating operational steps of the connection release circuit of FIG. 1;
[0041] [0041]FIG. 4 is a block diagram illustrating another configuration example of the traffic monitoring unit 2 of FIG. 1;
[0042] [0042]FIG. 5 is a block diagram illustrating a configuration example of a conventional traffic monitoring means for detecting the absence of the cell arrival; and
[0043] [0043]FIG. 6 is a flowchart illustrating operational steps performed in the software for controlling the monitoring means of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Now, embodiments of the present invention will be described in connection with the drawings.
[0045] [0045]FIG. 1 is a block diagram illustrating a connection releasing circuit according to an embodiment of the invention to be applied to a network node device. The connection releasing circuit of FIG. 1 comprises a cell detecting unit 1 , a traffic monitoring unit 2 , a connection-release control unit 3 , a cell processing unit 4 , a connection-release message generating unit 5 and an ATM switch 6 . The ATM switch 6 may be replaced by a cell inserting unit 6 , when the node device has only one output port to be connected to a next node. In the following description, they are represented by the ATM switch 6 .
[0046] The cell detecting unit 1 transfers input cells to the cell processing unit 4 and outputs a cell detection signal 10 to the traffic monitoring unit 2 by detecting arrival of each cell.
[0047] In the cell detection signal 10 , there is included information concerning a corresponding connection identifier such as VPI/VCI (Virtual Path Identifier/Virtual Channel Identifier) of the detected cell.
[0048] The traffic monitoring unit 2 outputs a time-out notification signal 20 to the connection-release control unit 3 and the connection-release message generating unit 5 when the cell detection signal 10 of a specific cut-through connection already established is not outputted from the cell detecting unit 1 during a certain time period.
[0049] The time-out notification signal 20 also includes information concerning corresponding connection identifier, the VPI/VCI, for example, of the cut-through connection as well as the cell detection signal 10 .
[0050] Receiving the time-out notification signal 20 , the connection-release control unit 3 controls the cell processing unit 4 to release a cut-through connection specified by the connection identifier included in the time-out notification signal 20 among the connections actually established.
[0051] The cell processing unit 4 takes charge of performing cell processings of the input cells, such as control of cell transfer and cell rejection, header conversion, or appending interior routing information to be used in the node device, when connections (including cut-through connections) are established, referring to connection information such as data prepared by the control software of the node device in the header conversion table or in the UPC (User Parameter Control) table, and takes charge of releasing a concerning cut-through connection by clearing the corresponding connection information when controlled by the connection-release control unit 3 .
[0052] The connection-release message generating unit 5 generates a connection-release message according to the time-out notification signal 20 supplied from the traffic monitoring unit 2 . The connection-release message is segmented into cells and switched/inserted into cells to be transmitted to the next node by the ATM switch 6 .
[0053] The ATM switch 6 (or the cell inserting unit 6 ) outputs cells supplied from the cell processing unit 4 and from the connection-release message generating unit 5 after rearranging them according to the interior routing information.
[0054] [0054]FIG. 2 is a block diagram illustrating inner configuration of the traffic monitoring unit 2 of FIG. 1, comprising a timer 21 and a time-out threshold memory 22 . The timer 21 has a plurality of time counters, and the time-out threshold memory 22 stores time-out threshold values each corresponding to each of the cut-through connections, respectively.
[0055] With a timer-enabling signal, one of the time counters is assigned to a cut-through connection and starts time counting. When the cell detection signal 10 is supplied from the cell detecting unit 1 , a corresponding time counter is reset, and when the count value of a time counter attains to its time-out threshold value, the time-out notification signal 20 is outputted together with the connection identifier corresponding to the concerning time counter.
[0056] [0056]FIG. 3 is a flowchart illustrating operational steps of the connection release circuit of FIG. 1.
[0057] Now, operation of the connection release circuit of FIG. 1 will be described referring to FIGS. 1 to 3 .
[0058] When a cut-through connection is established, a timer-enabling signal is supplied from the control software, with which a time counter in the timer 21 is started (at step S 10 ) and reset (at step S 11 ), and a time-out threshold value for the time counter is registered in the time-out threshold memory 22 . The time-out threshold value may be unique for all the time counters, or all the time-out threshold values may be preset when the node device is initialized. Here, the time-out threshold value is described to be distinct for each cut-through connection and to be registered when the cut-through connection is established by the control software.
[0059] Every time when arrival of a cell of the corresponding connection is detected (YES at step S 12 ) by the cell detecting unit 1 , the time counter is reset by the cell detection signal 10 outputted with the concerning connection identifier by repeating steps S 11 and S 12 .
[0060] When no cell of the corresponding connection arrives for one cycle of a timing clock (NO at step S 12 ), the concerning time counter is incremented (at step S 13 ) and checked whether the count value has attained to the corresponding time-out threshold value registered in the time-out threshold memory 22 .
[0061] In case the count value remains smaller than its time-out threshold value (NO at step S 14 ), the operational step returns to step S 12 to repeat steps S 11 to S 14 . When the count value is found to be equal to the time-out threshold value (YES at step S 14 ), a time-out notification signal 20 including concerning connection information is outputted (at step S 15 ). According to the time-out notification signal 20 , the concerning cut-through connection is released by the connection-release control unit 3 and a connection-release message is transmitted from the connection-release message generating unit 5 .
[0062] As heretofore described, the index for determining whether the time-out has arrived or not can be obtained at steps S 11 to S 13 in the flowchart of FIG. 3, while steps S 21 to S 25 must be performed by software processings in the flowchart of FIG. 6, conventionally, for obtaining the same index. Thus, the load to the control software for detecting traffic termination of the cut-through connections can be far reduced in the connection release method according to the embodiment in comparison with the conventional method of FIG. 6.
[0063] [0063]FIG. 4 is a block diagram illustrating another configuration example of the traffic monitoring unit 2 of FIG. 1.
[0064] In the traffic monitoring unit of FIG. 3, the timer 21 of FIG. 2 is replaced with a set of up/down counters 25 , and a set of cycle-clock generators 23 and a cell cycle memory 24 are further provided.
[0065] When a cut-through connection is newly established, one of the up/down counters 25 and one of the cycle-clock generators 23 are assigned to the concerning cut-through connection, and a corresponding cell cycle, with which the concerning cycle-clock generator outputs clock pulses, is determined in consideration of minimum cell traffic valuable for maintaining the concerning cut-through connection, and registered in the cell cycle memory 24 .
[0066] The concerning one of the up/down counters 25 is incremented according to the clock pulses generated by corresponding one of the cycle-clock generators 23 , and decremented according to the cell detection signal 10 of the cut-through connection.
[0067] When the count value of one of the up/down counters 25 attains to its time-out threshold value registered in the time-out threshold memory 22 , the time-out notification signal 20 is outputted together with the connection identifier.
[0068] In the traffic monitoring unit 2 of FIG. 2, the time-out notification signal 20 is generated on condition that there occurs no cell arrival for a certain time period. On the other hand, the time-out notification signal 20 is generated, in the traffic monitoring unit 2 of FIG. 4, even when the average cell arrival cycle of a cut-through connection remains for a certain time period to be longer than a predetermined cell cycle. Therefore, the cut-through connection, whereof cell traffic has become too small, can be released efficiently.
[0069] Heretofore, the embodiments of the invention are described to be employed for monitoring the traffic flow of ATM cells. However, application of the present invention is not limited to the ATM cells. It can be easily understood that the traffic monitoring unit 2 of FIG. 2 or FIG. 4 is applicable for monitoring traffic of layer-3 packets or layer-2 frames in the router, the layer-3 switch or the layer-2 switch, for example.
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To provide an apparatus for releasing a cut-through connection in a network node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node without charging large load on software processings, the apparatus for releasing a cut-through connection comprises a timer ( 21 ) having time counters each assigned to a cut-through connection and outputting a time-out notification signal ( 20 ) when a count value of the time counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the time counter being incremented along with time passage and being reset when the cut-through connection is established and when a cell of the cut-through connection arrives to the network node.
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TECHNICAL FIELD
The present invention relates to biotechnology and more particularly to an apparatus for cultivating tissue cells or microorganisms in suspension.
BACKGROUND ART
An apparatus for cultivating tissue cells and microorganisms in suspension is known in the art (SU, A1, No. 1331888, 1987); which comprises a closed reservoir to the bottom of which branch pipes are connected for feeding an aerating gas. One group of the branch pipes is arranged tangentially, and the other parallel to the cylindrical wall of the reservoir. In the process of cultivating, the aerating gas at once involves the suspension in a vortex motion with simultaneous circulation in the form of ascending and descending streams along the axis of the apparatus.
However, such an apparatus cannot be used for cultivating cells of animal and human tissues: these cells can be easily traumatized, since in the process of cultivating in suspension a large number of gas bubbles is formed, and destruction of these bubbles will cause death of many cells. Aeration by gas blowing leads to the formation of foam which also results in loss of a part of the cells. Foam suppression will require introducing costly non-toxic chemical defoaming agents into the nutrient medium, the technological process of cultivation will be complicated, and the use of defoaming agents will deteriorate the properties of the culture medium.
An apparatus for cultivating tissue cells and microorganisms in suspension is known in the art (U.S. Pat. No. 4,259,449, 1981), which comprises a cylindrical reservoir with a cover and branch pipes for feeding an aerating gas and removing gaseous medium, and a device for stirring the cell suspension, said device being made as a grid disposed in the bottom part of the reservoir. Air is supplied through the grid to the reservoir for creating hydrostatic pressure which prevents precipitation of cells from the suspension.
However, the productivity of such an apparatus in the process of cultivating cells is low owing to worsening of the mass transfer characteristics which, in turn, are impaired, insofar as the intensity of feeding the aerating gas is reduced in order to obviate traumatizing the cells. Even in this case traumatizing the cells cannot be ruled out completely, and intensive foam formation takes place.
Also known in the art is an apparatus for cultivating tissue cells and microorganisms in suspension (WO 92/05245, A1, Feb. 4, 1992), comprising a cylindrical reservoir with a cover and branch pipes for gas feeding and removal, a device for aerating and stirring the suspension. The device for the aeration and stirring comprises a horizontal blade wheel secured on a vertical power shaft and arranged in the top part of the reservoir directly under the cover, and an annular plate placed thereunder, provided with a central opening for the removal of gas, attached over the periphery thereof to the wall of the reservoir, forming an annular space around the blade wheel for gas feeding and removal. Slot openings are provided in the annular partition for the passage of gas, said slots being distributed uniformly along the circumference at an angle to the horizontal plane. The branch pipe for feeding the gas is installed in the cover coaxially with the blade wheel, and the branch pipe for the removal of gas is coupled to said annular space and disposed on the edge of the cover.
The disadvantage of such an apparatus is that formation of vortex motion of liquid (potential vortex with axial reverse flow) therein can be achieved at high gas flow velocities (greater than 15-18 m/s) above the surface of this liquid, i.e., said vortex formation involves considerable power inputs. At the same time, there occurs entrainment of liquid drops from the surface of the suspension with subsequent ejection of these drops onto the wall of the reservoir. Cells in the suspension drops become traumatized by the impact against the wall of the apparatus, i.e., mass death of the cells takes place. With a decrease in the gas flow velocity (6-8 m/s), an unstable flow of the liquid above the surface of the cell suspension is observed, i.e., the axial-symmetric vortex motion of the liquid is periodically changed for auto-oscillations of the liquid, in which mode there originates a wave travelling along the wall of the reservoir. The surface of the liquid becomes curved and represents an asymmetric paraboloid of rotation. All the liquid in the apparatus oscillates as a single whole, the entire apparatus starts rocking, and this produces an unfavorable effect on the cell cultivation process. Besides, the design of the apparatus allows cultivating cells with the reservoir being filled to a height equal to or less than one diameter of this reservoir. If the reservoir is filled with the cell suspension to a height greater than one diameter thereof, a stagnant zone will be formed at the bottom of the reservoir. During cultivation cells will inevitably settle in this zone and perish because of deficiency in oxygen.
An apparatus for cultivating tissue cells or microorganisms in suspension is known, which comprises a cylindrical reservoir with a cover and branch pipes, accordingly, for feeding an aerating gas and removing gaseous medium, and a device for aerating and stirring the suspension, comprising a horizontal blade wheel secured on a vertical hollow shalt and arranged in the top part of the reservoir directly under the cover (WO 93/21301, A1, Oct. 28, 1993—the first embodiment of the apparatus). The device for aerating and stirring the medium is provided with an annular partition installed in the cylindrical reservoir coaxially with the blade wheel, a clearance being formed between the cylindrical wall of the reservoir and the annular partition; the device is also provided with a mechanism for stabilizing the position of the annular partition with respect to the surface of the cell suspension. In accordance with this embodiment of the invention, the mechanism for stabilizing the position of the annular partition with respect to the surface of the cell suspension is made in the form of racks attached to the cover of the reservoir and to the annular partition with help of latches with a possibility of varying the position of the annular partition in relation to the height of the reservoir. The annular partition should be immersed to a depth H≧0.02(D 1 -D 2 ), where
D 1 is the diameter of the annular partition;
D 2 is the diameter of the axial opening in the annular partition.
A disadvantage of this embodiment of the apparatus is as follows. In many cases the process of cultivating cells and tissues is accompanied by changes in the level of the initial filling of the bioreactor (for example, owing to periodic sampling or the cultivation in the initial period being carried out with small volumes of the nutrient medium, whereas the final stage of cultivating is carried out with maximum filling of the reservoir of the reactor). As a result, the depth (H) of immersing the annular partition changes, i.e., the condition H≧≧0.02(D 1 -D 2 ) is disturbed. A decrease of the value (H) results in “locking” of the liquid drain through the axial opening in the annular partition, and this leads to deterioration of the process of stirring and aerating the cells being cultivated. Should the annular partition hang stationary above the surface of the cell suspension, the mass-transfer parameters will worsen still further. If the depth of immersing (H) of the annular partition is appreciably greater than H=0.02(D 1 -D 2 ), a travelling wave will be formed above the surface of the suspension, which gradually results in rocking the whole mass of the cell suspension, bringing it to the state of unstable stirring with lowered mass-transfer parameters. Therefore, under the conditions of periodic variations in the level of filling the reservoir of the apparatus in the process of cultivating, this device will be either almost inoperable, or introducing an additional mechanism will be required for automatic setting of the annular partition to the optimum depth on variations in the level of filling of the apparatus reservoir. This will make the apparatus much more complicated. Furthermore, the use of a stationary annular partition will involve additional power inputs and time expenditures for the bioreactor to reach the operating mode.
The known prior art most relevant to the proposed technical solution (prototype) is an apparatus for cultivating tissue cells or microorganisms in suspension, which comprises a cylindrical reservoir with a cover and branch pipes, accordingly, for feeding an aerating gas and removing gaseous medium, and a device for aerating and stirring the suspension, comprising a horizontal blade wheel secured on a vertical hollow shaft and arranged in the top part of the reservoir directly under the cover (WO 93/21301, A1, Oct. 28, 1993—the second embodiment of the apparatus). The device for aerating and stirring the medium is provided with an annular partition installed in the cylindrical reservoir coaxially with the blade wheel, a clearance being formed between the cylindrical wall of the reservoir and the annular partition; the device is also provided with a mechanism for stabilizing the position of the annular partition with respect to the surface of the cell suspension. The mechanism for stabilizing the position of the annular partition with respect to the surface of the cell suspension consists of floats with lead blades secured to the upper surface of the annular partition. The annular partition should be immersed to the depth H≧0.02(D 1 -D 2 ), where
D 1 is the diameter of the annular partition;
D 2 is the diameter of the axial opening in the annular partition.
The disadvantage of this embodiment of the apparatus (the embodiment with the floating annular partition) is in that for reaching a high density of plant and animal cells in suspension or in cultivating highly aerobic cell cultures, the velocity of the air vortex above the surface of the liquid phase should be greater than 7-8 m/s in order to provide optimum conditions for aerating said biological objects. But with such velocities of the air vortex the intensity of the ascending fluid flow (axial reverse flow) is such that the annular partition floats up (because of the origin of pressure difference above and under the partition) to the surface of the cell suspension (the condition of optimum immersion of the annular partition H≧≧0.02(D 1 -D 2 ) is disturbed, as a result of which the hydrodynamic mode of the flow (stirring) of the liquid (cell suspension) is disturbed, the conditions of aerating the cells being cultivated are worsened, this being followed by the precipitation of the biomass to the bottom of the reactor and death of the cells because of shortage in oxygen. On variations in the viscosity of the liquid phase in the process of cultivating biological objects, the annular partition, owing to its constant buoyancy, may uncontrollably change its position in relation to the surface of the liquid phase.
Besides, as the floating annular partition rotates in the cell suspension, stagnant shadow zones originate behind the floats, in which the cells being cultivated precipitate and accumulate. The lower layers of the cells perish in said zones because of shortage in oxygen, the quality of the finished product being thereby impaired and the technological characteristics of the apparatus lowered.
DISCLOSURE OF THE INVENTION
The present invention is directed to the provision of an apparatus for cultivating tissue cells or microorganisms in suspension which would ensure formation of an axial-symmetric vortex motion of liquid with axial reverse flow in the cell suspension without stagnant zones either at low velocities of gas movement (3-6 m/s) or at higher velocities thereof (7-10 m/s and more) above the surface of this liquid due to maintaining the annular partition at the optimal depth irrespective of changes in the intensity of the gas vortex above the surface of the cell suspension and changes in the viscosity of the liquid phase, which, in turn, will allow cultivating tissue cells or microorganisms having different oxygen requirements.
The set object is accomplished due to the fact that in an apparatus for cultivating tissue cells or microorganisms in suspension, which comprises a cylindrical reservoir with a cover and branch pipes, accordingly, for feeding an aerating gas and removing gaseous medium, and a device for aerating and stirring the suspension, comprising a horizontal blade wheel secured on a vertical hollow shaft and arranged in the top part of the reservoir directly under the cover, an annular partition installed in the cylindrical reservoir coaxially with the blade wheel with a clearance being formed between the cylindrical wall of the reservoir and the annular partition, and a mechanism for stabilizing the position of the annular partition with respect to the surface of the liquid phase (of the cell suspension), made in the form of guide elements and floats, according to the invention, the guide elements of the mechanism for stabilizing the position of the annular partition with respect to the surface of the liquid are made as detachable blades with a flat upper surface and a convex lower surface, said blades being oriented radially with respect to the annular partition and the surfaces of said blades defining an aerodynamic profile thereof of the “forward-sweep wing” type; the blades are attached with the help of struts to the upper surface of the annular partition or the blades are attached with the help of struts to the upper and lower surfaces of this partition, the blades being provided with units for varying the angle of attack with respect to the incoming flow of gas or liquid and for securing the blades to the struts on the annular partition and under it, respectively.
The aero- or hydrodynamic force originating as the blades of such design (with the profile of the “forward-sweep wing type) are streamlined by gas or liquid, is directed against the hydrodynamic force causing floating-up of the annular partition, and this allows said annular partition to be kept at an optimum depth when the velocity of the gas vortex above the surface of the liquid phase is greater than 6-7 m/s.
The units for varying the angle of attack with respect to the incoming flow of gas or liquid and for securing the blades to the struts on the annular partition and under it are made as clamping devices. Said units can be made as various plug-type connections, for instance, of the screw-nut or collet type.
When the blades on the annular partition are disposed above the surface of the cell suspension, the angle of attack of the blades with respect to the incoming flow of gas is from −15° to −90°, and when the blades are disposed in the liquid under the annular partition, the angle of attack of the blades with respect to the incoming flow of the liquid is from 0° to −35°.
In said angular ranges of inclination of the blades to the incoming flow of gas or liquid stable retention of the annular partition at an optimal depth with low power consumption is ensured.
The floats of the mechanism for stabilizing the position of the annular partition with respect to the surface of the liquid phase are made in the body of this partition. They are shaped as truncated unequal-sided pyramids oriented with the truncated vertexes toward the annular partition and fixed on the struts with a clearance in relation to the blades and the annular partition.
Such configuration of the floats ensures an increase in the reliability of maintaining the annular partition at an optimal depth irrespective of variations in the viscosity of the liquid phase, while the clearance between the floats and the annular partition eliminates stagnation shadow zones behind the floats, whereby settling, accumulation and death of the cultivated cells in these zones are prevented.
Arranging the floats in the body of the annular partition also eliminates stagnant shadow zones on this partition, whereby settling, accumulation and death of the cultivated cells in these zones are obviated.
The annular partition is immersed into the cell suspension to depth (H) equal to H=0.02-0.09(D 1 -D 2 ), where
D 1 is the diameter of the annular partition;
D 2 is the diameter of the axial opening in the annular partition.
A decrease in the value H<0.02(D 1 -D 2 ) results in “locking” the drain of liquid through the axial opening in the annular partition, this leading to deterioration of the process of stirring and aerating the cultivated cells, with subsequent settling of the biomass to the bottom of the reactor and death of the cells because of shortage in oxygen. If the depth of immersion (H) of the annular partition is appreciably greater than H=0.09(D 1 -D 2 ), a travelling wave is formed above the surface of suspension, which gradually brings the whole mass or the cell suspension into rocking and then into the mode of unstable stirring with lowered mass-transfer parameters (auto-oscillation mode). This negatively influences the viability and productivity of the biomass.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will further be explained by the description of a particular embodiment thereof with the reference to the accompanying drawings, on which:
FIG. 1 is a diagrammatic view of an apparatus for cultivating tissue cells and microorganisms in suspension, with blades disposed above an annular partition, and floats disposed in the body of this partition;
FIG. 2 is a sectional view of the apparatus, along A—A in FIG. 1;
FIG. 3 shows a mechanism for stabilizing the position of the annular partition in relation to the surface of liquid, with floats disposed on struts, and blades disposed above the annular partition and under it (the blades have small angles of attack with respect to the flow of gas and liquid);
FIG. 4 shows a mechanism for stabilizing the position of the annular partition in relation to the surface of liquid, with floats disposed on struts, and blades disposed above the annular partition (with the angle of attack of the blades with respect to the gas flow of −90°) and under this partition (with a small angle of attack of the blades with respect to the flow of liquid).
DESCRIPTION OF PREFERRED EMBODIMENT
The apparatus of the invention for cultivating tissue cells and microorganisms in suspension comprises a cylindrical reservoir 1 (FIG. 1) for a cell suspension, with a cover 2 and branch pipes 3 and 4 for supplying an aerating gas and removing gaseous medium, respectively, and a device for aerating and stirring the nutrient medium. The branch pipe 3 for supplying an aerating gas is installed above the cover 2 coaxially with the reservoir 1 , and the branch pipe 4 for gas removal is installed on an edge of the cover 2 . The device for aerating and stirring the cell suspension comprises a horizontal blade wheel 5 secured on a vertical hollow shaft 6 and arranged in the upper part of the reservoir 1 directly under the cover 2 ; an annular partition 7 installed in the reservoir 1 coaxially therewith and with the wheel 5 , a clearance being provided between the cylindrical wall of the reservoir 1 and the annular partition 7 ; and a mechanism for stabilizing the position of the annular partition 7 with respect to the surface of the cell suspension.
Lower surface 8 of the annular partition 7 is convex, and upper surface thereof is flat. Furthermore, the annular partition 7 has a diameter (D 1 ) equal to D 1 =(0.7÷6.9)D 0 , the diameter (D 2 ) of the axial opening in the partition 7 is equal to D 2 =(0.1÷0.3)D 1 , where D 0 is the inner diameter of the cylindrical reservoir 1 . The partition 7 should be immersed into the cell suspension to the depth (H) equal to H==0.02-0.09(D 1 -D 2 )
The mechanism for stabilizing the position of the annular partition 7 with respect to the surface of the cell suspension comprises floats 10 and guide elements 11 . The guide elements 11 of the mechanisms for stabilizing the position of the annular partition 7 in relation to the surface of the cell suspension are made as detachable blades 12 and 13 with a flat upper surface 14 and a convex lower surface 15 , said blades being oriented radially with respect to the annular partition and the surfaces of said blades defining an aerodynamic profile thereof of the “forward-sweep wing” type. Aerodynamic force F 1 originating as the blades 12 are streamlined by gas and hydrodynamic force F 2 originating as the blades 13 are streamlined by liquid, are directed against the hydrodynamic force F 3 which originates in the rotating stream of the liquid and causing floating-up of the annular partition 7 owing to the difference of pressures above and below this annular partition.
In one of the embodiments of the mechanism for stabilizing the position of the annular partition with respect to the surface of the liquid phase (FIG. 1) the blades 12 are installed with the help of struts 16 on the annular partition 7 , and the floats 10 are made in the body of this annular partition 7 .
In another embodiment of the mechanism for stabilizing the position of the annular partition with respect to the surface of the liquid phase (FIG. 3) the blades 12 are installed with the help of struts 16 on the annular partition 7 , and the blades 13 are installed with the help of struts 17 above the annular partition 7 . The floats 10 are attached to the struts 16 between the blades 10 and the annular partition 7 with the formation of clearances between the floats 10 and the partition 7 , as well as between the floats 10 and the blades 12 . The floats 10 are shaped as truncated unequal-sided pyramids oriented with the truncated vertexes toward the annular partition 7 .
In one of the modes of operation of the second embodiment of the mechanism for stabilizing the position of the annular partition with respect to the surface of the liquid phase (FIG. 4 ), the blades 12 are installed at the angle of −90° to the partition 7 and serve only for providing rotation of this partition in the liquid (in the cell suspension).
The blades 12 and 13 are provided with units for varying the angle of attack with respect to the incoming flow of gas or liquid and for securing the blades to the struts 16 on the annular partition 7 and to the struts 17 under the annular partition 7 , respectively. The units for varying the angle of attack of the blades 12 and 13 with respect to the incoming flow of gas or liquid and for securing them, respectively, to the struts 16 and 17 are made as clamping devices 18 of the screw-nut or collet type.
The angle of attack of the blades of 12 with respect to the incoming flow of the gas is from −15° to −90°, and the angle of attack of blades of the blades 13 with respect to the incoming flow of the liquid is from 0° to −35°.
The annular partition 7 is immersed into the cell suspension to the depth (H) equal to H=0.02-0.09(D 1 -D 2 ) where:
D 1 is the diameter of the annular partition;
D 2 is the diameter of the axial opening in the annular partition.
For rotation of the blade wheel 5 a magnetic coupling 19 is used, one of the moving parts 20 of which is mounted on the hollow shaft 6 above the cover 2 , and the other part 21 is disposed on a hollow axle 22 . The hollow axle 22 is disposed coaxially with the shaft 6 around the moving part 20 of the coupling 19 . The part 20 of the coupling 19 is brought in rotation, for example, through a belt transmission 23 by the electric motor 24 . In the bottom part of the reservoir 1 (in FIG. 1) a branch pipe 25 is disposed for the admission of the cultural medium and the inoculum. The same branch pipe 25 serves for draining the cell suspension on completion of the cultivation process.
The proposed apparatus operates as follows:
For cultivating highly aerobic biological objects (cells of animals or insects), the blades 12 are installed with the help of the clamping devices 18 on the struts 16 of the annular partition 7 with the angle of attack, for instance, of −35° (FIG. 1 ), or the blades 12 are installed on struts 16 with the angle of attack of the blades 12 , for instance, of −25°, and the blades 13 on the struts 17 of the annular partition 7 with the angle of attack of the blades 13 , for instance, of −15° (FIG. 3 ).
For cultivating low-aerobic biological objects (some types of bacteria), the blades 12 are installed with the help of the clamping devices 18 on the struts 16 of the annular partition 7 with the angle of attack, for example, of −16° (FIG. 1 ), or the blades 12 are installed on the struts 16 of the annular partition 7 with the angle of attack, for example, of −16° and the blades 13 are installed on the struts 17 of the annular partition 7 with the angle of attack of the blades 13 , for instance, of 0° (FIG. 3 ).
After that the cylindrical reservoir 1 with the installed annular partition 7 and the mechanism for stabilizing its position with respect to the surface of the liquid is filled with the nutrient medium under sterile conditions so that a space should be left above the surface of the medium in the upper part of the reservoir 1 for movement of the aerating gas, and the annular partition 7 be disposed on the surface of or at a certain depth in the nutrient medium (by selecting the buoyancy of the floats 10 ), which is less than the optimum depth H=0.02-0.09(D 1 -D 2 ). The blades 12 in this case are disposed above the surface of the liquid. For example, for the reservoir with the diameter D 0 =200 mm the optimum parameters of the apparatus are as follows: D 1 =160 mm; D 2 =32 mm; H=8 mm. Further, the temperature regime required for cultivating cells or microorganisms is set up, the necessary dose of inoculum is introduced, and the electric motor 24 is switched on. The necessary number of revolutions of the blade wheel 5 is set, depending on the requirements of the cultivation technology requirements. When the blade wheel 5 rotates above the surface of the nutrient medium with the inoculum, a rarefaction is created in the zone close to the axis of the reservoir 1 and an elevated pressure is created on the periphery of this reservoir. Under the effect of the pressure difference between the periphery and the zone close to the axis of the gas space, a swirling flow of the aerating gas is formed above the surface of the liquid, with the field of potential vortex velocity on the periphery of the reservoir 1 and an axial reverse flow in the zone near the axis thereof, which generates in the liquid a similar turbulent rotary motion with intensive stirring along the axis of the reservoir.
When cultivating low-aerobic biological objects, for instance, some types of bacterial cells, the rotation velocity of the gas vortex is set to be 3-6 m/s. In this case there is generated aerodynamic force F 1 (it originates as the blades 12 are streamlined by the gas flow) or aerodynamic force F 1 and hydrodynamic force F 2 are generated (the latter force originates as the blades 13 are streamlined by the liquid flow), or hydrodynamic force F 2 alone is generated. Said forces F 1 (FIG. 1) or F 1 and F 2 (FIG. 3 ), or F 2 (FIG. 4) additionally immerse the annular partition 7 , setting it at the optimal depth (H), which is in the range of depths H=0.02-0.09(D 1 -D 2 ).
When cultivating highly aerobic biological objects, for instance, plant or animal cells, the rotation velocity of the gas vortex is set to be higher than 7-10 m/s. With such velocities of the gas vortex, the annular partition 7 which is in the rotating stream of liquid, is acted upon not only by the forces F 1 (FIG. 1 ), or F 1 and F 2 (FIG. 3 ), or F (FIG. 4) directed vertically downwards, but also by additional hydrodynamic force F 3 (owing to the origination at such velocities of a flow of liquid stemming from the difference in pressures above the partition 7 and below it), said force F 3 being directed vertically upwards and causing the partition 7 to float up. The force F 3 compensates partly for the action of the forces F 1 and F 2 , and the annular partition 7 retains reliably its position in the range of depths H=0.02-0.09(D 1 -D 2 ).
Thus, the mechanism for stabilizing the position of the annular partition 7 allows to maintain it at the optimal depth (H) irrespective of the mode of cultivating or the volume of suspension in the apparatus. Owing to the installation of the annular partition 7 in the suspension, the intensity and directivity of its ascending and descending streams is increased (i.e., the efficiency of the gas vortex is increased).
According to calculations, at the average gas flow velocity above the surface of suspension V gas =10 m/s, the average rotation rate of the blades 12 together with the annular partition 7 (D 1 =160 mm) with respect to the liquid will be V part. =2.446 m/s, and force F 3 =0.393 N.
With the length of the blades 12 l 1 =7.5 cm and the chord h 1 =2 cm; with their number n 1 =3; with the angle of attack of the blades 12 with respect to the gas flow α 1 =−35°, force F 1 ==0.4873 N. Thus, in the embodiment of the mechanism for stabilizing the position of the annular partition 7 with respect to the surface of the liquid, shown in FIG. 1, the force F 1 is partially compensated for by the action of the force F 3 and said partition will reliably retain its position at the depth H.
With the length of the blades 13 l 2 =3.0 cm and the chord h 2 =1.5 cm; the number of the blades n 2 =6; the angle of attack of the blades 13 with respect to the liquid flow α 2 =0° the force F 2 =0.4845 N. Therefore, in the embodiment of the mechanism for stabilizing the position of the annular partition 7 with respect to the surface of the liquid, shown in FIG. 4, the force F 2 will be partially compensated for by the action of the force F 3 , and said partition will reliably retain its position at the depth H. Besides, stability of the position of the annular partition 7 in the given embodiment of the mechanism is supported by varying the buoyancy of the floats 10 .
The floats 10 configured as unequal-sided truncated pyramids also allow to maintain the annular partition 7 at the optimal depth irrespective of the mode of cultivating or the volume of the cell suspension in the apparatus, since in case the partition 7 happens to float up to some extent, say, because of an increase in the velocity of the gas vortex or in the density of the cell suspension in the course of cultivation, the buoyancy of the floats 10 decreases (owing to their specific shape), and the partition 7 again returns to the depth (H).
Arranging the floats 10 in the body of the partition 7 (FIG. 1) or setting a clearance between the floats 10 and the annular partition 7 (FIGS. 3, 4 ) provides elimination of stagnant (shadow) zones on the surface 9 of the partition 7 , and also prevents settling, accumulation and death of cultivated cells in said zones.
In the process of cultivating cells or microorganisms the aerating gas interacts with the liquid phase through its free surface above the annular partition 7 without mixing with the liquid. Therefore, no gas bubbles are present in the cell suspension, so that traumatizing of the cells and formation of foam are ruled out. At any velocity of the gas vortex, at least in the range of 3-20 m/s, detachment of suspension drops from the suspension surface does not occur, and traumatizing of cells is additionally reduced.
Due to rarefaction in the zone close to the axis of the blade wheel 5 , additional inflow of the aerating gas to the reservoir 1 is effected through the branch pipe 3 , and owing to an increased pressure on the periphery of the gas space above the surface of the suspension, the outflow of the gaseous medium from the reservoir 1 is effected through the branch pipe 4 . An optimal ratio of the aerating gas components for the provision of normal conditions of cultivating cells or microorganisms is achieved.
Thus, the proposed design features of the apparatus of the present inventions with different embodiments of the mechanism for stabilizing the position of the partition 7 with respect to the liquid medium makes it possible to ensure formation of an axial-symmetric rotary motion of liquid with axial reverse flow in the cell suspension without stagnant zones either at low velocities of gas movement (3-6 m/s) or at higher velocities thereof (7-10 m/s and more) above the surface of this liquid due to maintaining the annular partition at the optimal depth irrespective of changes in the intensity of the gas vortex above the surface of the cell suspension. This, in turn, allows cultivating tissue cells or microorganisms sensitive to mechanical traumatizing and having different oxygen requirements, as well as attaining a higher concentration of any types of cells in suspension.
Industrial Applicability
The proposed apparatus for cultivating tissue cells and microorganisms in suspension can be widely used in microbiological, medical and foodstuffs industry.
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An apparatus for cultivating tissue cells or microorganisms in suspension, in a manner which ensures formation of an axially symmetric vortex motion of liquid with an axial countercurrent flow in the cell suspension without stagnant zones at various locations. The apparatus has guide elements that stabilize the position of an annular partition with respect to the surface of the suspension, including first blades and second blades. The first blades are attached to the upper surface of the partition with the help of the first struts. The second blades are attached to the lower surface of the partition with the help of the second struts. Each of the first blades and the second blades is provided with a clamping device of “screw-nut” or collet type for varying the angle of attack with respect to the incoming flow of gas and liquid and for securing to the respective strut on the upper surface of the annular partition and at the lower surface of it.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] An embodiment of the present invention relates to a print management program, a print management device, a print management method, and a print system for managing print jobs.
[0003] 2. Description of the Related Art
[0004] In a commercial printing industry, a commercial print service provider receives a printed material (such as a catalog, or an advertisement) from a customer, the commercial print service provider produces a customer's desired printed output material from the printing material, and the commercial print service provider receives compensation in return for delivering the printed output material to the customer. The commercial print service provider produces the printed output material by performing plural processes including the reception of the printing material and the delivery of the printed output material. The processes from the reception of the printing material to the delivery of the printed output material include prepress processes, such as the reception of the printing material from the customer, a reception of printing conditions for a printed output material, a color correction, a layout modification, and a correction of a binding position; post-press processes, such as proof printing for the customer to confirm the result of the prepress processes, printing and subsequent binding, and pressure bonding; and the delivery of the printed output material to the customer. Here, the number of the processes between the reception of the printing material and the delivery of the printed output material varies depending on a customer's desired printing condition for the printed output material.
[0005] In a conventional commercial printing industry, a commercial print service provider tends to receive an order for printed materials that require mass printing from a customer, and the commercial print service provider responds to the mass printing of the printed materials by the above described processes. Further, for the printed materials that require the mass printing, there are many cases in which a printing condition on the printed materials from a customer is fixed. In the conventional commercial printing industry, the commercial print service provider performs the mass printing under a determined single printing condition. After completing the lot printing, the printing condition is altered, and the mass printing under the altered printing condition is performed again. Through such a print cycle, the customer's desired printed output material is produced.
[0006] In the above printing cycle, plural processes tend to occur, when the printing condition is altered. Therefore, when the printing condition is not altered, the commercial print service provider can perform continuous printing in an ongoing process. Thus the mass printing can be efficiently performed.
[0007] Recently, in the commercial printing industry, a so-called “print-on-demand (POD) market” is emerging, where relatively small lots of printed materials are delivered to a customer in a short delivery time. In the POD market, orders from plural customers tend to occur. Consequently, in the POD market, printed materials submitted to a commercial print service provider and printing conditions on printed output materials are diversified.
[0008] Further, recently, digital printing has been widely used, and a computer has been widely used for controlling processes for producing printed materials. For example, technologies are emerging, such as a workflow for submitting a printed material as electronic data through a network and for controlling the above described plural processes. For example, in the workflow, printing operations in the plural processes are defined using a job ticket, which is called “Job Definition Format (JDF),” and the printing operations are controlled by a printing system.
[0009] In accordance with such a change in the printing environment, commercial print service providers have been introducing the computer technologies into the printing systems, so as to produce printed materials, in response to receiving orders for the printed materials. On the other hand, the commercial service providers have been required to set up printing systems that can handle diversified printing conditions for the printed materials from customers. Further, in order to produce diversified printed materials desired by the customers, the commercial print service providers have been required to respond in a system aspect, such as introduction of plural printer devices and peripheral devices, as well as in a process aspect, such as modification of the above described plural processes in a relatively short cycle.
[0010] The commercial print service providers have been required to respond as described above. Additionally, the commercial print service providers may be required to improve operational efficiency so as to increase profit. Measures for improving the operational efficiency include simplification of the processes.
[0011] In the production print (PP) business, as a prepress process, an imposition process and a print setting process are performed by using plural applications and digital front ends (DFE). In the print setting process, finisher processing includes more setting items, such as settings of stapling and hole-punching, as well as various settings of folding and cutting, compared to setting items of a multi-function peripheral (MFP). In a prepress process, a print preview image may be altered or use of an unavailable function may be constrained, depending on a capability of a post-processing (finishing) device.
[0012] Conventionally, as a technique for improving usability of the device, the following technique has been known. Namely, under a condition in which a specification of a job ticket that can be processed by a printing system may vary, a determination is made as to whether the job ticket transmitted to a device can be processed by a printing device (e.g., Patent Document 1 (Japanese Published Unexamined Application No. 2010-111100)).
[0013] In the PP business, not only a finisher, which can perform hole-punching and stapling, is connected to a printing device, but also various devices, such as a stand-alone device that can perform hole-punching and stapling, a stand-alone folding device, and a stand-alone cutting device, are combined to produce a single printed output material.
[0014] Therefore, when available functions are restricted only based on a capability of the printing device, even though the printing system includes the stand-alone device that can perform hole-punching and stapling, a print job of a printed output material, which may be output by using the whole printing system, may not be produced. Further, even if there are some functions that may not be performed simultaneously in the printing device by itself because of constraining settings, the functions may be performed in the whole printing system by utilizing the stand-alone devices that can perform hole-punching and stapling. However, in this case, the printing system may not notify an operator of the availability of the functions.
[0015] An embodiment of the present invention is developed in view of the above problems. An objective of the embodiment is to provide a print management program, a print management device, a print management method, and a print system that can perform print setting, in which the entire printing processes are reflected.
SUMMARY OF THE INVENTION
[0016] In one aspect, there is provided a non-transitory computer readable recording medium that stores a print management program causing a computer to function as a retrieval unit that retrieves information about first functions of an image forming device and information about second functions of plural second devices, wherein the image forming device and plural of the second devices are connected to a print system including the computer; and a determination unit that determines whether the second functions of the second devices can process a print job, when the first functions of the image forming device cannot process the print job. When the determination unit determines that the second functions of the second devices cannot process the print job, the print management program constrains the second functions of the second devices from being utilized.
[0017] In another aspect, there is provided a print management device including a retrieval unit that retrieves information about first functions of an image forming device and information about second functions of plural second devices, wherein the image forming device and the second devices are connected to a print system including the print management device; and a determination unit that determines whether the second functions of the second devices can process a print job, when the first functions of the image forming device cannot process the print job. When the determination unit determines that the second functions of the second devices cannot process the print job, the print management device constrains the second functions from being utilized.
[0018] In another aspect, there is provided a print management method executed by a computer. The method includes a retrieval step of retrieving information about first functions of an image forming device and information about second functions of plural second devices, wherein the image forming device and plural of the second devices are connected to a print system including the computer; and a determination step of determining whether the second functions of the second devices can process a print job, when the first functions of the image forming device cannot process the print job. When the determination step determines that the second functions of the second devices cannot process the print job, the computer constrains the second functions of the second devices from being utilized.
[0019] In another aspect, there is provided a print system including a print management device and an image forming device. The print management device includes a retrieval unit that retrieves information about first functions of the image forming device and information about second functions of plural second devices, wherein the image forming device and the second devices are connected to the print system including the print management device; and a determination unit that determines whether the second functions of the second devices can process a print job, when the first functions of the image forming device cannot process the print job. When the determination unit determines that the second functions of the second devices cannot process the print job, the print management device constrains the second functions from being utilized.
[0020] Further, a method, a device, a system, a computer program, a recording medium, and a data structure, for which a portion of the embodiment or an arbitrary combination of portions of the embodiment is applied, may be effective as aspects of the embodiment.
[0021] According to the embodiment, a print management program, a print management device, a print management method, and a print system that can perform print setting, in which the entire printing processes are reflected, can be provided.
[0022] Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a block diagram showing an example of an overall configuration of a print system according to an embodiment;
[0024] FIG. 2 is a system configuration diagram schematically showing the configuration of the print system;
[0025] FIG. 3 is a hardware configuration diagram of an example of a PC;
[0026] FIG. 4 is a processing block diagram of an example of a PC server;
[0027] FIG. 5 is a configuration diagram of an example of a device function information table;
[0028] FIG. 6 is a configuration diagram of an example of an inter-function constraint information table;
[0029] FIG. 7 is a configuration diagram of an example of an inter-device constraint information table;
[0030] FIG. 8 is a configuration diagram of an example of an ordered constraint information table;
[0031] FIG. 9 is a processing block diagram of an example of a client PC;
[0032] FIG. 10 is a flowchart showing an example of a displaying procedure of a job ticket setting screen;
[0033] FIG. 11 is an image diagram of an example of the job ticket setting screen;
[0034] FIG. 12 is an image diagram of an example of the job ticket setting screen, in which a stapling function is checked; and
[0035] FIG. 13 is a flowchart showing an example of a procedure, when a function in the job ticket setting screen is checked.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Hereinafter, an embodiment of the present invention is explained by referring to accompanying figures. Here, the print system described below is to facilitate understanding of the embodiment. The embodiment is not limited to the print system described below.
[0037] FIG. 1 is a block diagram showing an example of an overall configuration of a print system according to the embodiment. The print system according to the embodiment includes one or more end user environments 1 ; and a POD print system environment 2 . The end user environments 1 and the POD print system environment 2 are connected through a network 3 , such as a LAN.
[0038] Each of the end user environments 1 is, for example, an environment where there is a client PC 11 connected to a corporate intranet. As an example of an application for a POD printing service, a print job generating application is installed on the client PC 11 . The client PC 11 can generate a print job.
[0039] The print job generating application 12 can execute an imposition function for attaching plural logical page images to a page, or an image editing function for adding information, such as a header, a footer, or a page number. Further, the print job generating application 12 can specify an instruction for hole-punching and an instruction for stapling, for printing and bookbinding.
[0040] In the POD print system environment 2 , a process management unit 20 , a digital printing unit 30 , and a post-press unit 40 are connected online. In the POD print system environment 2 , the process management unit 20 instructs the digital printing unit 30 and the post-press unit 40 to execute works. The process management unit 20 centrally manages the workflow of the POD print system environment 2 .
[0041] The process management unit 20 receives print jobs (print orders) from the end user environments 1 , and stores the print jobs. Further, the process management unit 20 can construct a workflow from works to be executed by the corresponding units, based on a print job from an end user. In addition, the process management unit 20 can efficiently perform scheduling of the works to be executed by the digital printing unit 30 , the post-press unit 40 , and operators. Furthermore, when an error occurs during an automatic operation of the print system, the process management unit 20 may notify the operator of the occurrence of the error. In general, the process management unit 20 includes at least one PC server 21 .
[0042] The digital printing unit 30 reads a paper manuscript received from an end user by using a scanner, such as a monochrome MFP or a color MFP, and outputs the results, in accordance with the instructions on the print job received from the process management unit 20 . In this manner, the digital printing unit 30 performs copying. The digital printing unit 30 can print a document and/or an image file received from an end user through the client PC 11 and through one of a printer driver and a hot folder, by using a printing device, such as the monochrome MFP or the color MFP. Further, the digital printing unit 30 can print a scanned image file that is scanned by the scanner. Furthermore, the digital printing unit 30 can print a document and/or an image file created by editing the foregoing document and/or image file, and the scanned image file.
[0043] The post-press unit 40 controls post-processing devices in accordance with operating instructions on post-press job received from the process management unit 20 . Here, the post-processing devices includes, at least, a paper folding device, a saddle stitching bookbinding device, a perfect binding device, a paper cutting device, a mail inserting device, and a collator. Further, the post-press unit 40 performs finishing processes to the printed paper, which has been output from the digital printing unit 30 . The finishing processes includes, for example, a folding process, a saddle stitching bookbinding process, a perfect binding process, a cutting process, a mail inserting process, and a collating process. The post-press unit 40 includes post-processing devices for performing post-processes after digital printing, such as a stapler 41 and a hole punch device 42 .
[0044] FIG. 2 is a system configuration diagram schematically showing the configuration of the print system according to the embodiment. FIG. 2 shows an example where the overall configuration of the print system shown in the block diagram of FIG. 1 is more simply configured.
[0045] An end user, for example, edits an image, performs an imposition process, inserts text, and instructs an execution of the post-process, by using the application for the POD printing service from the client PC 11 in the end user environment 1 . In this manner, the end user issues a print order (sends a print job) to the process management unit 20 in the POD print system environment 2 . The print job includes order information, which is referred to as a job ticket, and print data.
[0046] The PC server 21 in the process management unit 20 generates a print job (a print order) in accordance with the information (print setting) included in the job ticket. Then the PC server 21 sends instructions of the print data to the digital printing unit 30 and the post-press unit 40 .
[0047] The established configuration of the digital printing unit 30 varies depending on the POD print system environment 2 . However, in many cases, the digital printing unit 30 includes a combination of color or monochrome printers that can handle high-speed printing and that can print high-quality images. Recent printers can perform not only printing functions online, but also can perform post-processing of the printing, at once, online. Here, the post-processing includes at least hole-punching, cutting, perfect binding, and ring binding.
[0048] In the configuration example of FIG. 2 , a color printer 31 of the digital printing unit 30 includes a stapling function and a hole-punching function. Further, the post-press unit 40 includes the stand-alone stapler 41 having a stapling function, and the stand-alone hole-punch device 42 having a hole-punching function.
[0049] The client PC 11 in the end user environment 1 can be realized, for example, by a PC 50 having a hardware configuration shown in FIG. 3 . FIG. 3 is a hardware configuration diagram of an example of the PC 50 . The PC 50 shown in FIG. 3 includes an input unit 51 , an output unit 52 , a recording media reading unit 53 , an auxiliary storage unit 54 , a main storage unit 55 , a processing unit 56 , and an interface 57 , which are mutually connected through a bus 59 .
[0050] The input unit 51 is, for example, a keyboard and a mouse. The input unit 51 is used for inputting various signals. The output unit 52 is, for example, a display device. The output unit 52 is used for displaying various windows and data. The interface unit 57 is, for example, a modem or a LAN card. The interface unit 57 is used for connecting the PC 50 to the network 3 .
[0051] The print job generating application installed on the client PC 11 is, at least, a part of various programs that control the PC 50 . The print job generating application may be distributed as a recording medium 58 , or downloaded from the network 3 .
[0052] As the recording medium 58 , various types of recording mediums may be utilized. For example, as the recording medium 58 , a recording medium, such as a CD-ROM, a flexible disk, or a magnetic optical disk, may be utilized. In such a recording medium, information is optically, electrically, or magnetically recorded. Further, as the recording medium 58 , a semiconductor memory, such as a ROM, or a flash memory, may be utilized. In such a semiconductor memory, information is electrically recorded.
[0053] When the recording medium 58 , in which the print job generating application is recorded, is set up in the recording media reading unit 53 , the print job generating application is installed onto the auxiliary storage unit 54 from the recording medium 58 through the recording media reading unit 53 . The print job generating application that is downloaded from the network 3 or the like is installed onto the auxiliary storage unit 54 through the interface 57 . The auxiliary storage unit 54 stores the installed print job generating application, necessary files, and data.
[0054] When the print job generating application is executed, the main storage unit 55 retrieves the print job generating application from the auxiliary storage unit 54 and stores the print job generating application therein. Then the processing unit 56 executes various processes (described later) in accordance with the print job generating application stored in the main storage unit 55 .
[0055] Similarly, the PC server 21 in the process management unit 20 is realized, for example, by a PC shown in FIG. 3 . A processing unit 56 of the PC server 21 realizes various processes of the process management, in accordance with a process management program stored a main storage unit 55 of the PC server 21 .
[0056] The PC server 21 in the process management unit 20 is realized, for example, by processing blocks shown in FIG. 4 . FIG. 4 is a processing block diagram of an example of the PC server 21 . A process management program is installed on the PC server 21 . The PC server 21 realizes a device function information collecting unit 61 , a device capability information transmitting unit 62 , a device function information table 63 , an inter-function constraint information table 64 , an inter-device constraint information table 65 , and an ordered constraint information table 66 , by executing the process management program.
[0057] The device function information collecting unit 61 collects device function information from the devices included in the digital printing unit 30 , such as the color printers 31 , and from the devices included in the post-press unit 40 , such as the stapler 41 and the hole-punch device 42 . The device function information collecting unit 61 retrieves device function information from management information base (MIB) information of the devices by using, for example, the simple network management protocol (SNMP) of TCP/IP. The device function information collecting unit 61 stores the collected device function information in the device function information table 63 .
[0058] The device capability information transmitting unit 62 transmits the device function information stored in the device function information table 63 , inter-function constraint information stored in the inter-function constraint information table 64 , inter-device constraint information stored in the inter-device constraint information table 65 , and ordered constraint information stored in the ordered constraint information table 66 to the client PC 11 as device capability information.
[0059] The device function information table 63 stores the device function information collected from the devices. The inter-function constraint information table 64 stores the inter-function constraint information, which has been set by an operator or the like. The inter-device constraint information table 65 stores the constraint information among the devices, which has been set by the operator or the like. The ordered constraint information table 66 stores the ordered constraint information, which has been set by the operator or the like.
[0060] FIG. 5 is a configuration diagram of an example of the device function information table 63 . The device function information table 63 indicates, for each of the device names shown in FIG. 5 , availability or unavailability of a color printing function, a monochrome printing function, a stapling function, and a hole-punching function, by ON or OFF.
[0061] However, for an actual device, not only the ON/OFF information of the stapling function, but also various information, such as information about staplable positions, an angle of stapling, the number of simultaneously staplable staples, and a shape of the staples, may be defined as the function information. Further, for the actual device, not only the ON/OFF information of the hole-punching function, but also various information, such as information about the number of the holes, and hole-punched positions, may be defined as the function information. Here, for the sake of simplicity, only the ON/OFF information of the stapling function and the hole-punching function is indicated.
[0062] The device function information table 63 shown in FIG. 5 indicates, for example, that, for the color printer 31 in the digital printing unit 30 , the color printing function, the monochrome printing function, the stapling function, and the hole-punching function are available (ON). Further, the device function information table 63 shown in FIG. 5 indicates that, for the stapler 41 in the post-press unit 40 , only the staple function is available (ON). Further, the device function information table 63 shown in FIG. 5 indicates that, for the hole-punch device 42 in the post-press unit 40 , only the hole-punching function is available (ON).
[0063] FIG. 6 is a configuration diagram of an example of the inter-function constraint information table 64 . The inter-function constraint information table 64 indicates, as the constraint information, that, when the device function information satisfies a combinatorial condition for a function of one of the devices, the selection of the function is constrained. Here, the device function information has been obtained from the devices in the system configuration example of FIG. 2 .
[0064] The inter-function constraint information table 64 indicates pairs of a first combination and a second combination. Here, the first combination includes a first device name, a first function name, and a first functional value. The second combination includes a second device name, a second function name, and a second functional value. The inter-function constraint information table 64 indicates that the first combination and the second combination included in each of the above described pairs are constrained from simultaneously occurring within the same system.
[0065] The inter-function constraint information 101 indicates that, since the color printing function and the monochrome printing function of the color printer 31 are mutually exclusive functions, they are constrained from simultaneously being turned on. With the inter-function constraint information 101 , for the color printer 31 , only one of the color printing function and the monochrome printing function can be selected at once.
[0066] The inter-function constraint information 102 indicates that, since the color printing function and the monochrome printing function of the color printer 31 are mutually exclusive functions, they are constrained from simultaneously being turned off. With the inter-function constraint information 102 , for the color printer 31 , only one of either the color printing function or the monochrome printing function is selected at once.
[0067] The inter-function constraint information 103 constrains the stapling function and the hole-punching function of the color printer 31 from being simultaneously turned on. Here, for some devices, the stapling function and the hole-punching function may be simultaneously performed. However, FIG. 6 shows the example, where the simultaneous selection of the stapling function and the hole-punching function is constrained.
[0068] FIG. 7 is a configuration diagram of an example of the inter-device constraint information table 65 . The inter-device constraint information table 65 of FIG. 7 indicates, as the constraint information, that, when the device function information obtained from the devices in the system configuration example of FIG. 2 satisfies a combinatorial condition between devices, the functions specified by the combinatorial condition are constrained from being simultaneously selected.
[0069] The inter-device constraint information table 65 indicates pairs of a first combination and a second combination. Here, the first combination includes a first device name, a first function name, and a first functional value. The second combination includes a second device name, a second function name, and a second functional value. The inter-device constraint information table 65 indicates that the first combination and the second combination included in each of the above described pairs are constrained from simultaneously occurring in the corresponding first device and the second device.
[0070] The inter-device constraint information 111 constrains the stapling function of the color printer 31 and the stapling function of the stapler 41 from being simultaneously turned on. In other words, the inter-device constraint information 111 indicates that once the printed output material is stapled by the color printer 31 , the stapler 41 is not allowed to staple the printed output material.
[0071] The inter-device constraint information 112 constrains the hole-punching function of the color printer 31 and the hole-punching function of the hole-punch device 42 from simultaneously being turned on. In other words, the inter-device constraint information 112 indicates that once the printed output material is hole-punched by the color printer 31 , the hole-punch device 42 is not allowed to hole-punch the printed output material.
[0072] In this manner, the inter-device constraint information table 65 constrains the specific combinations of the functions between the devices from simultaneously being selected. In other words, the inter-device constraint information table 65 specifies constraining rules applied to a combination of the devices.
[0073] FIG. 8 is a configuration diagram of an example of the ordered constraint information table 66 . The ordered constraint information table 66 indicates constraint information about an execution order of functions, where the functions are performed by the different devices. Here, the information about the functions is indicated by the device function information obtained from the devices in the configuration example of FIG. 2 . For example, in the system configuration example of FIG. 2 , after the stapler 41 of the post-press unit 40 completes stapling, the color printer 31 of the digital printing unit 30 is constrained from printing. The ordered constraint information table 66 indicates the constrained execution orders of the functions, where the functions are performed by the different devices.
[0074] The ordered constraint information table 66 shows that after a first function specified by a first combination of a first device name, a first function name, and a first functional value is being performed, a second function specified by a second combination of a second device name, a second function name, and a second functional value is constrained from being performed.
[0075] The inter-function constraint information table 64 and the inter-device constraint information table 65 define constraining rules that constrain the specific combinations of the device functions from simultaneously being performed. Namely, the inter-function constraint information table 64 and the inter-device constraint information table 65 define constraining rules that do not depend on the execution orders of the device functions. On the other hand, the ordered constraint information table 66 defines the constraining rules that depend on the execution orders of the device functions. Namely, the ordered constraint information table 66 indicates that after completing an execution of a specific function of a device, an execution of another specific function of another device is constrained. In other words, each of the combinations of the device functions indicated in the ordered constraint information table 66 can be executed, provided that the execution order of the device functions in the combination are reversed. Further, the inter-function constraint information table 64 defines the constraining rules on the device functions of a single device. On the other hand, the ordered constraint information table 66 defines the constraining rules on the combinations of the first functions and the second functions, where the first function and the second function in each of the combinations are performed by different devices.
[0076] The ordered constraint information 121 indicates that, after completing the execution of the hole-punching function of the color printer 31 , the stapling function of the stapler 41 is constrained from being executed. The ordered constraint information 122 indicates that, after completing the execution of the hole-punching function of the hole-punch device 42 , the stapling function of the stapler 41 is constrained from being executed. The ordered constraint information 123 indicates that, after completing the execution of the staple function of the stapler 41 , all the functions of the color printer 31 are constrained from being executed. Here, “*” in the ordered constraint information table 66 represents all functions. The ordered constraint information 124 indicates that, after completing the execution of the hole-punching function of the hole-punch device 42 , all the functions of the color printer 31 are constrained from being executed.
[0077] The PC server 21 in the process management unit 20 includes the device function information table 63 , the inter-function constraint information table 64 , the inter-device constraint information table 65 , and the ordered constraint information table 66 . Here, the device function information table 63 defines the functions of the devices included in the digital printing unit 30 or the post-press unit 40 . The inter-function constraint information table 64 defines combinations of functions within a single device, where the functions included in each of the combinations are constrained from being simultaneously selected. The inter-device constraint information table 65 defines combinations of functions, where the functions included in each of the combinations are executed by different devices and are constrained from being simultaneously specified. The ordered constraint information table 66 defines constraint information that depends on execution orders of combinations of functions, where the functions included in each of the combinations are executed by different devices.
[0078] The constraint information stored in the inter-function constraint information table 64 , the inter-device constraint information table 65 , the ordered constraint information table 66 may be retrieved from the devices in the digital printing unit 30 or the post-press unit 40 by a communication function that utilizes, for example, the SNMP and the MIB. Alternatively, the above described constraint information may be registered in the PC server 21 in the process management unit 20 in advance.
[0079] The device capability information transmitting unit 62 transmits the device function information stored in the device function information table 63 , the inter-function constraint information stored in the inter-function constraint information table 64 , the inter-device constraint information stored in the inter-device constraint information table 65 , and the ordered constraint information stored in the ordered constraint information table 66 to the print job generating application 12 installed on the client PC 11 in the end user environment 1 through the network 3 .
[0080] The print job generating application 12 performs the screen control based on the device function information table 63 , the inter-function constraint information table 64 , the inter-device constraint information table 65 , and the ordered constraint information table 66 , so that available functions and unavailable functions are displayed on the screen.
[0081] The client PC 11 in the end user environment 1 is realized by, for example, processing blocks shown in FIG. 9 . FIG. 9 is a processing block diagram of an example of the client PC 11 . The print job generating application 12 has been installed on the client PC 11 . The client PC 11 realizes a device capability information receiving unit 71 , an available function determination unit 72 , and a screen control unit 73 by executing the print job generating application 12 .
[0082] The device capability information receiving unit 71 receives the device function information stored in the device function information table 63 , the inter-function constraint information stored in the inter-function constraint information table 64 , the inter-device constraint information stored in the inter-device constraint information table 65 , and the ordered constraint information stored in the ordered constraint information table 66 from the PC server 21 as the device capability information.
[0083] The available function determination unit 72 determines whether functions are available or unavailable based on the received device capability information, as described later. The screen control unit 73 performs the screen control of a job ticket setting screen based on the availability or the unavailability of the functions, as described later.
[0084] FIG. 10 is a flowchart showing an example of a procedure of displaying the job ticket setting screen. At step S 1 , the device capability information receiving unit 71 receives the device capability information from the PC server 21 . In general, the device capability information is text in the XML format, and the device capability information is retrieved by transferring the file using a protocol, such as HTTP. However, the data format and the protocol are not limited to that of the example.
[0085] At step S 2 , the available function determination unit 72 determines whether functions are available or unavailable based on the received device capability information, as described later. The screen control unit 73 performs the screen control of the job ticket setting screen based on the availability or the unavailability of each of the functions, so that the functions which have been determined to be available is selectable on the screen, as described later.
[0086] FIG. 11 is an image diagram of an example of the job ticket setting screen. When each of the functions takes two values as shown in the device function information table 63 in FIG. 5 , the job ticket setting screen 200 in FIG. 11 may be a checkbox, or another function selection screen. For example, when each of the functions takes more than two values, the job ticket setting screen 200 may be a function selection screen, such as a combo box.
[0087] Further, when a particular function is set to be selectable on the job ticket setting screen 200 , the screen control unit 73 may cause an item for selecting the particular function to be displayed on the job ticket setting screen 200 . When the particular function is not set to be selectable on the job ticket setting screen 200 , the screen control unit 73 may cause the item for selecting the particular function not to be displayed on the job ticket setting screen 200 . Alternatively, when the particular function is not set to be selectable, the screen control unit 73 may cause the item for selecting the particular function to be displayed with “greyed out.” The available function determination unit 72 determines the availability or unavailability of the functions, not based on the individual device function information, but based on the information about the whole print system.
[0088] In FIG. 11 , since the stapling function and the hole-punching function are determined to be available in the whole print system based on the device function information stored in the device function information table 63 of FIG. 5 , the job ticket setting screen 200 selectably displays the items for selecting the stapling function and the hole-punching function. Incidentally, on the job ticket setting screen 200 of FIG. 11 , the color printing function has already been checked. Thus the available function determination unit 72 determines that the monochrome printing function is unavailable, based on the inter-function constraint information stored in the inter-function constraint information table 64 of FIG. 6 . Therefore, the monochrome printing function is displayed with “greyed out.”
[0089] FIG. 12 is an image diagram of an example of a job ticket setting screen 210 , where the stapling function has been checked. The job ticket setting screen 210 of FIG. 12 is an example of a warning display for warning that the functions are performed by plural devices. Here, a method, a form, and a format of the display are not limited to that of the job ticket setting screen 210 shown in FIG. 12 . The warning display may be indicated by a balloon 211 as shown in FIG. 12 . Alternatively, the warning display may be indicated by a color, an icon, or another display method. The available function determination unit 72 may notice, in advance, that the functions are performed by the plural devices, based on the inter-function constraint information stored in the inter-function constraint information table 64 of FIG. 6 . Further, the warning display for warning that the functions are performed by the plural devices may be indicated at a time that the staple function is checked. Alternatively, the warning display may be indicated at a time that is immediately prior to the hole-punching function being checked (at a time that the mouse cursor overlaps with the checkbox), or at a time that the hole-punching function is checked.
[0090] When the hole-punching function is checked and the run button 212 is pressed on the job ticket setting screen 210 of FIG. 12 , a print job generating unit (not shown) realized by the print job generating application 12 generates a job ticket corresponding to the color printing function, the stapling function and the hole-punching function, and instructs an execution of print processing to the POD print system environment 2 (a portion of the print system).
[0091] The process management unit 20 in the POD print system environment 2 may determine as to which devices actually perform the stapling function and the hole-punching function. Further, the process management unit 20 may determine an execution order for performing the stapling function and the hole-punching function. Further, the execution order for performing the stapling function and the hole-punching function may be defined in the job ticket.
[0092] FIG. 13 is a flowchart showing an example of a procedure when a function on the job ticket setting screen 200 is checked. When an operator operating the client PC 11 checks the stapling function on the job ticket setting screen 200 , the available function determination unit 72 determines, at step S 11 , functions within the same device, which are constrained from being simultaneously performed with the stapling function, based on the inter-function constraint information stored in the inter-function constraint information table 64 of FIG. 6 . At step S 11 , the functions within the same device, which are constrained from being simultaneously performed with the stapling function, are determined.
[0093] This is because, in general, it is more efficient to perform all the processes within the same device. Here, if it is more efficient to distribute the processes over different devices, the constraining rules among the different devices may be determined earlier. In the embodiment, based on the inter-function constraint information 103 , it can be understood that the stapling function and the hole-punching function are constrained from being simultaneously selected.
[0094] Since the available function determination unit 72 can obtain the inter-device constraint information, when the available function determination unit 72 determines, at step S 11 , that there are some functions which are constrained from being performed, the available function determination unit 72 determines, at step S 12 , whether the constrained functions can be performed by another device. In the embodiment, it can be understood from the device function information table 63 of FIG. 5 that the hole-punching function can be performed by the hole-punch device 42 .
[0095] Further, when the available function determination unit 72 determines, at step S 12 , that the constrained functions are also constrained from being performed by another device, the available function determination unit 72 performs the process of step S 13 . At step S 13 , the available function determination unit 72 disables the setting of the constrained functions on the job ticket setting screen 200 .
[0096] When the available function determination unit 72 determines, at step S 12 , that the constrained functions can be performed by another device, namely, the constrained functions can be performed by plural devices, the available function determination unit 72 determines, at step S 14 , constraining rules among the devices, based on the inter-device constraint information table 65 .
[0097] Here, when the constrained functions are also constrained from being performed by the plural devices, the available function determination unit 72 determines that the functions are unavailable, and performs the process of step S 15 . At step S 15 , the available function determination unit 72 disables the setting of the constrained functions on the job ticket setting screen 200 . In the embodiment, it can be understood from the inter-device constraint information table 65 of FIG. 7 that the combination of the stapling function of the color printer 31 and the hole-punching function of the hole-punch device 42 is not constrained.
[0098] Further, when the functions are not constrained from being performed by the plural devices, the available function determination unit 72 determines, at step S 16 , ordered constraining rules among different devices based on the ordered constraint information table 66 of FIG. 8 . When the functions are constrained from being performed irrespectively of the execution order, the available function determination unit 72 performs the process of step S 17 . At step S 17 , the available function determination unit 72 disables the setting of the constrained functions on the job ticket setting screen 200 .
[0099] On the other hand, when the functions are not constrained with respect to a particular execution order, the available function determination unit 72 enables the setting of the functions, and indicates the warning display for warning that the functions are performed by the plural devices at step S 18 .
[0100] It can be understood from the ordered constraint information 121 of the ordered constraint information table 66 in FIG. 8 that an execution order of performing the hole-punching function of the color printer 31 and subsequently performing the stapling function of the stapler 41 is constrained. Further, it can be understood from the ordered constraint information table 66 in FIG. 8 that an execution order of performing the stapling function of the color printer 31 and subsequently performing the hole-punching function of the hole-punch device 42 is not constrained.
[0101] According to the embodiment, the print setting can be assigned to the job ticket, while taking into consideration of the functions and the constraining rules of the color printer 31 and the functions of the constraining rules of the whole printing processes. Further, when the functions are performed by the plural devices, a delivery delay and a cost increase may occur because of the increase in the amount of the work. Therefore, in such a case, according to the embodiment, the print system may warn an operator that the functions will be performed by the plural devices. Since the operator may distinguish functions that can be performed by a single device from functions that can be performed in the whole printing processes, the operator can assign a desired print setting to a job ticket while taking into consideration whether the functions are performed by the plural devices.
[0102] The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.
[0103] The present application is based on Japanese Priority Application No. 2011-045641 filed on Mar. 2, 2011, the entire contents of which are hereby incorporated herein by reference.
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A non-transitory computer readable recording medium that stores a print management program causing a computer to function as a retrieval unit that retrieves information about first functions of an image forming device and information about second functions of plural second devices; and a determination unit that determines whether the second functions of the second devices can process a print job, when the first functions of the image forming device cannot process the print job. Here, the image forming device and the second devices are connected to a print system including the computer. When the determination unit determines that the second functions of the second devices cannot process the print job, the print management program constrains the second functions of the second devices from being utilized.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional application Ser. No. 60/297,635, filed Jun. 12, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved process for producing N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide.
BACKGROUND OF THE INVENTION
[0003] Zaleplon, whose systematic chemical name is N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide, possesses anxiolytic, antiepileptic, sedative and hypnotic properties. It is approved by the U.S. Food and Drug Administration for short-term treatment of insomnia.
[0004] Zaleplon and a process for preparing it are disclosed in U.S. Pat. No. 4,626,538, which is incorporated herein by reference. In the '538 patent process, shown in Scheme 1, N-(3-acetylphenyl)ethanamide is condensed with dimethylformamide dimethyl acetal to form N-[3-[3-(dimethylamino)-1-oxo-2-propenyl)]phenyl]acetamide. The primary amide of the acetamide is then alkylated with ethyl iodide, forming N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide 1. To prepare zaleplon in the last step, ethylacetamide 1 is condensed with 3-amino-4-cyanopyrazole 2 by refluxing the reactants in glacial acetic acid for eight hours.
[0005] U.S. Pat. No. 5,714,607 discloses an improvement upon the '538 patent process. According to the '607 patent, zaleplon can be obtained in improved yield and purity if the final step of the '538 patent process is modified by adding water to the acetic acid solvent at about 10% to about 85% (v/v). It is also reported that the reaction is faster when water is added. As stated in the '607 patent, the improved conditions shorten the reaction time from about 3-3.5 to about 1-3.5 hours. According to Table 1 of the '607 patent, zaleplon was obtained in yields ranging from 81.7-90% and in HPLC purity ranging from 98.77 to 99.4%.
[0006] Nevertheless, development of a more advantageous procedure for production of zaleplon under acidic conditions starting from ethylacetamide and 3-amino-4-cyanopyrazole in high yield and purity and in a short time is still desirable.
[0007] In order to obtain marketing approval for a new drug product, manufacturers have to submit to the regulatory authorities evidence to show that the product is acceptable for human administration. Such a submission must include, among other things, analytical data to show the impurity profile of the product to demonstrate that the impurities are absent, or are present only a negligible amount. For such a demonstration there is a need for analytical methods capable of detection of the impurities and reference markers for identification and assaying thereof.
SUMMARY OF THE INVENTION
[0008] The present invention provides a process for producing zaleplon by reacting N-[3 -[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide and 3-amino-4-cyanopyrazole in a liquid reaction medium of water and a water-miscible organic compound under acidic conditions. The reaction proceeds through an imine intermediate that is prone to precipitate from water. The imine intermediate remains dissolved in the reaction media of this invention. The process proceeds rapidly at ambient temperature to produce highly pure zaleplon in high yield. The process is suitable for small or large-scale production of pure zaleplon.
[0009] In another embodiment, the present invention relates to pure zaleplon having a purity, as determined by HPLC, of at least 98.5%.
[0010] In yet another aspect, the present invention relates to pure zaleplon having a purity of at least 99% as determined by HPLC.
[0011] In another aspect, the present invention relates a method for preparation of a novel chemical compound, N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-5-yl)phenyl]-N-ethylacetamide, which is the regioisomer and main process impurity of zaleplon. This new compound, which is characterized by NMR and MS investigations, can be used as a reference marker in analysis of zaleplon.
[0012] In still a further aspect, the present invention relates to analytical methods for testing and show the impurity profile of zaleplon. These methods are also suitable for analyzing and assaying zaleplon and its main impurity which, in the methods of the invention, serves as reference marker.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a typical HPLC chromatogram for zaleplon produced by the method of the present invention.
[0014] FIG. 2 shows the HPLC chromatigram of the novel compound N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-5-yl)phenyl]-N-ethylacetamide produced by the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention is based on a mechanistic study and new observations concerning the reaction of N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide 1 with 3-amino-4-cyanopyrazole 2 leading to zaleplon. Our observations include identification of a reaction intermediate, imine 3 by high performance liquid chromatography-mass spectroscopy. Our results, including the identification of the imine intermediate, are consistent with a reaction mechanism that is set forth in Scheme 2.
[0016] According to Scheme 2, ethylacetamide 1 undergoes Michael-type addition of the 3-amino group of pyrazole 2. α-Elimination of dimethylamine from a transient charge-separated intermediate restores the double bond, which rearranges to form imine intermediate 3. The 2-nitrogen atom of the pyrazole ring cyclizes onto the keto group with elimination of water forming zaleplon.
[0017] Both the addition and cyclization reactions occur in the presence of acid. The dimethylamine liberated in the first elimination step binds an equivalent of acid. Consequently an excess of acid is required for this sequence of acid catalyzed conversions to go to completion.
[0018] The starting materials, imine intermediate, and product have significantly different polarities. It became apparent during the course of our study that while aqueous mineral acid is a good solvent for both starting materials 1 and 2, it is not a good solvent for imine intermediate 3 or zaleplon. Imine intermediate 3 tends to separate from aqueous mineral acids that do not contain a significant amount of a water-miscible organic co-solvent and forms an oily precipitate, thereby preventing the reaction from going to completion. The starting materials and imine intermediate are soluble in a variety of protic and polar aprotic organic solvents. Unfortunately, the rate of the reaction is solvent dependent and is much slower in the organic solvents we tried than it is in water.
[0019] Overcoming the above-mentioned solubility problems, the present invention provides a process for producing zaleplon whereby ethylacetamide 1, or an acid addition salt thereof, is reacted with 3-amino-4-cyanopyrazole 2, or an acid addition salt thereof, in a reaction medium of water and at least one water-miscible organic compound in the presence of an acid. The quantity of water, organic solvent, and acid can be adjusted independently. The water-miscible organic solvent can tend to solubilize imine intermediate 3. As stated previously, an equivalent or more of an acid must be present in order to maintain acidic conditions throughout the course of the reaction. By including at least one water-miscible organic compound, the solvating power in the reaction medium is decoupled from the choice of acid. This flexibility is advantageous because it enables optimization of the production process simultaneously for yield and reaction rate. Such flexibility is not possible in prior art processes. In the process described in the '607 patent, varying the amount of acid is the only means of altering the solvating properties of the reaction medium.
[0020] In particular, the reaction medium for production of zaleplon from compounds 1 and 2 according to this invention is a mixture of water and at least one water-miscible organic solvent (organic co-solvent). Organic co-solvents suitable in the practice of the present invention include organic compounds that do not bear carboxylic acid groups, such as C 1 -C 6 monohydroxyl and polyhydroxyl alcohols (e.g. methanol, ethanol, propanol), nitriles (e.g. acetonitrile, propionitrile), ethers (e.g. tetrahydrofuran, dioxane), nitro compounds (e.g. nitromethane, nitroethane), amides (e.g. formamide, dimethylformamide, acetamide, dimethylacetamide, hexamethylphosphoramide and hexamethylphosphortriamide, sulfoxides (e.g. dimethylsulfoxide), and other water-miscible organic compounds that are inert to the reagents and/or the product. Any of the above recited co-solvents can be used alone, or any of them can be used in any combination.
[0021] The ratio of organic co-solvent to water in the reaction medium is preferably from about 10% to about 90% (v/v) organic co-solvent in water, more preferably from about 30% to about 40% (v/v) organic co-solvent in water. Most preferably, the reaction medium is a mixture of about 36% (v/v) methanol in water.
[0022] As used herein in connection with the composition of water and organic co-solvent in a reaction medium, volume % (vol-%), % v/v, and N % v/v (where N is a number from 1 up to and including 100) are synonymous and calculated as follows (illustrated for species A):
Vol-% A =Wt A ×ρ A /(Wt A ×ρ A +Wt B ×ρ B )
where:
Wt A and Wt B are the weights in grams of species A and B, respectively, and ρ A and ρ B are the densities, in g./ml. of species A and B, respectively.
[0026] Suitable acids for use in the practice of the method of the present invention include inorganic acids, such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid and boric acid, and water-miscible organic acids, such as formic acid, acetic acid, propionic acid, oxalic acid, malonic acid and tartaric acid. The acid should be used in at least an amount capable of protonating all of the liberated dimethylamine, thereby maintaining an at least moderately acidic environment for ring closure of imine intermediate 3 and completion of the zaleplon-forming reaction. An acid may be added individually as such to the reaction mixture. Alternatively, the acid may be added as the proton donating component of an acid addition salt of ethylacetamide 1 or pyrazole 2. Thus, it will be appreciated by those skilled in the art that up to about two equivalents of acid may be added by using acid addition salts of the starting materials. Therefore, separate individual addition of an acid as such is not strictly necessary to establish acidic conditions.
[0027] Preferred acids include hydrochloric acid and phosphoric acid, either of which is preferably present in the reaction mixture in an amount of from about one to about two molar equivalents with respect to the limiting reagent. Starting materials 1 and 2 may be used in any ratio. The one present in the lesser molar amount constitutes the limiting reagent to which the amount of acid should be compared. The starting materials are preferably used in approximately equimolar amounts due to their cost.
[0028] In accord with especially preferred sets of production parameters used in Examples 1, 3-5, 13, 14, 19 and 20, the reaction goes to completion within several hours at ambient temperature, without external heating or cooling. The process according to the present invention is preferably conducted at a temperature in the range of from about 20° C. to about 25° C. The reaction also may be conducted at elevated temperature, up to the boiling point of the reaction medium (e.g. Examples 16-18), as well as at lower temperatures (e.g. Example 21).
[0029] The reaction time necessary for complete conversion is about 2 to about 8 hours at a temperature in the range of from about 20° C. to about 25° C., depending upon the composition of the reaction mixture. The time required for the reaction to go to completion may be decreased to about 0.2 hours at an elevated temperature of about 50° C. Reactions performed with cooling require more time to reach completion (about 6 to about 8 hours) but yield a product of somewhat higher purity (compare Examples 13 and 21).
[0030] By following the preferred embodiments of the invention, the zaleplon product precipitates from the reaction mixture by the end of the reaction or may be induced to precipitate by cooling. The precipitate may be recovered by filtration. Cooling the reaction mixture before collecting the product may increase the yield.
[0031] This process produces pure N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide (zaleplon) in the highest yield currently reported. The process of this invention achieves a higher reaction rate at lower temperatures than is possible using known processes for producing zaleplon.
[0032] The purity of the product, as isolated, is very high (above 98.5%). However, if desired, pure zaleplon obtained by the process of the present invention and having a purity of at least 98.5%, preferably at least 99%, as determined by HPLC, can be recrystallized from a solvent, preferably from methanol, ethanol, or a reaction medium of water and a co-solvent such as methanol, ethanol, acetonitrile and the like in order to produce a drug substance that complies with regulatory requirements.
[0033] Formation of N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-5-yl)phenyl]-N-ethylacetamide (4), regioisomer of zaleplon, has been discovered as a main impurity in the synthesis of zaleplon starting from 3-amino-4-cyanopyrazole and N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide. The amount of this impurity has been found to be strongly dependent on the reaction conditions.
[0034] According to the reaction conditions claimed in the U.S. Prov. Pat. Appl. 60/297,635 the amount of this impurity is in the range of 0.2-0.5% (HPLC) in the crude product.
[0035] In another embodiment the present invention provides a method for the preparation of the novel N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-5-yl)phenyl]-N-ethylacetamide (4) starting from 3-amino-4-cyanopyrazole and N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide by reacting them in water or in the mixture of water and a water miscible organic solvent in the presence of an acid. The amount of this impurity can be increase by up to 5% (HPLC) be use of a high concentration of a strong acid. This facilitates the isolation and characterization of this new compound.
[0036] The reaction can be performed at 20° to 30° C. or at higher temperature up to the boiling point of water. A temperature of 20° to 30° C. is preferred. As a water miscible organic solvent both polar protic (acetic acid, methanol, ethanol i-propanol) or aprotic (acetonitrile, tetrahydrofuran, dimethylformamide) solvents can be applied. As an acid, both mineral (hydrochloric, sulfuric, phosphoric) and organic (acetic, trifluoroacetic, methanesulfonic) can be used. Hydrochloric acid is the preferred preferred acid.
[0037] In a preferred embodiment of the present invention the reaction is performed in water in the presence of hydrochloric acid at about 25° C. The isolation of the mixture of zaleplon and its regioisomer 4 can be performed by evaporation, filtration, extraction and by combination of this methods.
[0038] In a particularly preferred embodiment of the present invention, after completion of the reaction, the reaction mixture is diluted with water and the precipitated zaleplon is removed by filtration. Then the filtrate is neutralized to precipitate the mixture of zaleplon and its regioismer 4. A further crop of the mixture can be obtained by extraction of water phase with water inmiscible organic solvents such as ethylacetate, dichloromethane, chloroform and like.
[0039] Isolation of compound 4 can be performed by chromatography. Column chromatography, preparative TLC or HPLC can be applied. Column chromatography is preferred. As a packing, silica gel or aluminium oxide can be used. Silica gel is preferred. As an eluent, different organic solvents or mixtures of them can be used. Mixtures of dichloromethane and acetone are preferred. The isolated 2 was characterized with 1 H-nmr and 13 C-nmr spectroscopic as well as mass spectrometric investigations to prove its structure.
[0040] In a further embodiment, the present invention provides novel HPLC methods for determination of the impurity profile and assay of zaleplon.
[0041] In one such embodiment, suitable for complete resolution (separation) of the peak of zaleplon (1) from the peak of structurally very similar compound (4) as well as the other impurities, the present invention provides a method for HPLC including the steps of:
a, dissolving zaleplon sample in acetonitrile:water (1:1) diluent, b, injecting the sample solution onto an RP-18, 5 μm, HPLC column, c, gradient eluting with a mixture of ammonium-formate buffer and acetonitrile, and d, measuring of the amounts of each impurity at 245 nm wavelength with a UV detector and appropriate recording device.
[0046] In another embodiment, particularly suitable for analysis and assay of zaleplon and its main impurity 4 in a drug substance and pharmaceutical compositions containing zaleplon, the present invention provides an HPLC method including the steps of:
a, dissolving zaleplon sample in acetonitrile:water (1:1) diluent, b, injection the sample solution onto an RP-18, 3 μm, HPLC column, c, eluting the sample from the column using a mixture of ammonium-format buffer and acetonitrile with determined flow rate, and d, measuring the zaleplon content of the relevant sample at 245 nm wavelength with a UV detector and appropriate recording apparatus
[0051] Having thus described the various aspects of the present invention, the following non-limiting examples are provided to illustrate specific embodiments.
EXAMPLES
Example 1
[0052] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (2.6 g, 0.01 mol) and 3-amino-4-cyanopyrazole (1.08 g, 0.01 mol) were dissolved in the mixture of water (35 cm 3 ) and methanol (20 cm 3 ). Phosphoric acid (85%) (0.67 cm 3 , 0.01 mol) was then added and the mixture was stirred at room temperature for about 4 hours. The reaction mixture was then cooled to about 5° C. and the crystalline product that formed was collected, washed with water and dried at about 60° C. to yield zaleplon (2.79 g, 91.5%) in 98.83% purity as determined by HPLC.
Example 2
[0053] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (2.6 g, 0.01 mol) and 3-amino-4-cyanopyrazole (1.08 g, 0.01 mol) were dissolved in the mixture of water (35 cm 3 ) and ethanol (20 cm 3 ). Phosphoric acid (85%) (0.67 cm 3 , 0.01 mol) was then added and the mixture was stirred at room temperature for about 8 hours. The reaction mixture was then cooled to about 5° C. and the crystalline product that formed was collected, washed with water and dried at about 60° C. to yield zaleplon (2.95 g, 96.7%) in 99.09% purity as determined by HPLC.
Example 3
[0054] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (2.6 g, 0.01 mol) and 3-amino-4-cyanopyrazole (1.08 g, 0.01 mol) were dissolved in the mixture of water (35 cm 3 ) and methanol (20 cm 3 ). Concentrated (37%) hydrochloride acid (1.0 cm 3 , 0.012 mol) was then added and the mixture was stirred at room temperature for about 2 hours. The reaction mixture was then cooled to about 5° C. and the crystalline product that formed was collected, washed with water and dried at about 60° C. to yield zaleplon (2.80 g, 91.8%) in 98.69% purity as determined by HPLC.
TABLE 1 The effects of different reaction conditions are illustrated in Table 1 Moles of Temp. Volume of Co-solvent Acid Time Yield Purity 3 Ex. ethylacetamide 1 (C) Water (cm 3) Co-solvent Volume (cm 3) Acid Moles Equivalents (h) (%) (%) 4 0.01 23 35 MeOH 20 H 3 PO 4 0.015 1.5 4 94.5 98.82 5 0.01 23 35 MeOH 20 H 3 PO 4 0.020 2 4 93.0 98.80 6 0.01 23 15 MeOH 40 H 3 PO 4 0.015 1.5 36 90.0 99.40 7 0.01 23 ... MeOH 55 H 3 PO 4 0.015 1.5 >72 ... ... 8 0.01 23 35 EtOH 14 H 3 PO 4 0.015 1.5 8 96.1 98.40 9 0.01 23 35 DMF 20 H 3 PO 4 0.015 1.5 10 87.9 98.57 10 0.01 23 35 ACN 20 H 3 PO 4 0.015 1.5 20 78.2 99.74 11 0.01 23 35 THF 20 H 3 PO 4 0.015 1.5 72 89.2 98.40 12 0.01 23 35 MeOH 20 HCl 0.010 1.0 24 82.0 98.95 13 0.01 23 35 MeOH 20 HCl 0.015 1.5 2 92.1 98.9l 14 0.01 23 35 MeOH 20 HCl 0.020 2.0 2 95.1 99.12 15 0.01 23 35 ... ... AcOH 0.260 26 5 85.0 98.97 16 0.01 50 35 MeOH 20 H 3 PO 4 0.015 1.5 0.25 90.2 99.25 17 0.01 50 35 MeOH 20 HCl 0.015 1.5 0.2 88.9 99.16 18 0.01 65 ... MeOH 55 H 3 PO 4 0.015 1.5 16 79.0 98.71 Determined as percent area of the peak corresponding to zaleplon in an HPLC chromacogram of the crude reaction mixture.
Example 19
[0055] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (26.0 g. 0.1 mol) and 3-amino-4-cyanopyrazole (10.8 g, 0.1 mol) were dissolved in the mixture of water (350 cm 3 ) and methanol (200 cm 3 ). Concentrated (37%) hydrochloric acid (12.5 cm 3 , 0.12 mol) was then added and the mixture was stirred at room temperature for about 2 hours. The reaction mixture was then cooled to about 5° C. and the crystalline product formed was collected, washed with water and dried at about 60° C. to yield zaleplon (29.8 g, 97.7%) in 99.08% purity as determined by HPLC.
Example 20
[0056] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (2.6 g, 0.01 mol) and 3-amino-4-cyanopyrazole-hydrochloride (1.44 g, 0.01 mol) were dissolved in the mixture of water (35 cm 3 ) and methanol (20 cm 3 ). Concentrated (37%) hydrochloric acid (0.83 cm 3 , 0.01 mol) was then added and the mixture was stirred at room temperature for about 2 hours. The reaction mixture was then cooled to about 5° C. and the crystalline product formed was collected, washed with water and dried at about 60° C. to yield zaleplon (2.93 g, 96.1%) in 99.16% purity as determined by HPLC.
Example 21
[0057] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (2.6 g, 0.01 mol) and 3-amino-4-cyanopyrazole (1.08 g, 0.01 mol) were dissolved in the mixture of water (35 cm 3 ) and methanol (20 cm 3 ). Concentrated (37%) hydrochloric acid (1.25 cm 3 , 0.015 mol) was then added and the mixture was stirred at about 15° C. for about 8 hours. The reaction mixture was then cooled to about 5° C. and the crystalline product formed was collected, washed with water and dried at about 60° C. to yield zaleplon (2.87 g, 94.1%) in 99.5% purity as determined by HPLC.
Example 22
Preparation of N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-5-yl)phenyl]-N-ethyl-acetamide
[0058] N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide (5.2 g, 0.02 mol) and 3-amino-4-cyanopyrazole (2.16 g, 0.02 mol) were dissolved in the mixture of water (50 ml) and concentrated hydrochloric acid (40 ml) and the mixture was stirred at room temperature for 8 h. The reaction mixture was then cooled to 5° C. and the precipitate was removed by filtration. The filtrate was neutralized by concentrated aqueous ammonia solution to precipitate 380 mg of the mixture of zaleplon and its regioisomer 4 which was collected by filtration. The filtrate was extracted with 100 ml of ethylacetate to give 100 mg of the mixture of the above two compounds upon evaporation. The two crops combined were put to a silica gel column (100 g) and the elution was performed by the solvent mixture of chloroform and acetone 3:1 (v/v) to yield as a second crop 240 mg (4%) of 4; mp 194-196° C.; 1 H-NMR (CDCl 3 ) δ (ppm) 1.143 (t, 3H), 1.876 (s, 3H), 3.804 (q, 2H), 7.361 (d, 1H), 7.532 (d, 1H), 7.613 (t, 1H), 8.018 (s, 1H), 8.159 (d, 1H), 8.375 (s, 1H), 8.805 ((d, 1H); 13 C-NMR (CDCl 3 ) δ (ppm) 12.89, 22.68, 43.84, 83.17, 107.71, 112.84, 127.17, 127.48, 130.62, 131.63, 136.67, 137.46, 144.10, 148.31, 149.99, 158.60, 169.90; MS (EI, 70 EV) m/z (%) 305 (M + , 18), 248 (59).
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The present invention provides a process for the production of N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide (zaleplon), an active ingredient that is approved for the treatment of insomnia. The process involves reacting N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide or a salt thereof with 3-amino-4-cyanopyrazole or a salt thereof under acidic conditions in a reaction medium comprising a mixture of water and a water-miscible organic compound.
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RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority under 35 U.S.C. § 120 from PCT Application Ser. No. PCTIEP00/04784, filed May 25, 2000.
FIELD OF INVENTION
[0002] The invention generally relates to a firearm system for a handgun which possesses an exchangeable barrel with a cartridge chamber and a breech.
BACKGROUND OF THE INVENTION
[0003] In these documents, when reference is given to position, the assumption is of a normal model of a handgun in a horizontal position, and “forward” is in the direction of shooting.
[0004] If a silenced weapon is to truly function without sound, the expansion noise of the gases which drive the bullet and the sound of the cartridge detonation must be suppressed. A third sound produced by the fired bullet will last as long as the bullet travels at supersonic velocity. For the suppression of the sound of the bullet, it is possible to choose cartridges, such that the velocity of the bullets is initially subsonic. Alternatively, one can excise gas relief passages in the barrel, which divert a portion of the driving gases into a silencer, and assure that the velocity of the bullet in flight does not exceed the supersonic level. This diversion of gas is only a reasonable measure when the nominal muzzle velocity of the bullet does not exceed the supersonic border. Finally, it is also possible to make use of special, somewhat experimentally made cartridges, the bullets of which do not attain supersonic velocities.
[0005] Since the 1960's, the caliber of military weapons has become steadily smaller. In the second world war, a caliber of 6.5 mm (Italy, Japan, Sweden) was generally seen as being too small to be effective as a military bullet. The average caliber was between 7.5 to 8 mm at that time.
[0006] Today, the modern NATO caliber is set at only 5.56 mm (.223 Remington). In the former Soviet Union, an effort was made to reduce caliber still further, striving for approximately 4.5 mm.
[0007] The bullet of a .223 cartridge weighs about 3.5 g. In order to maintain a sufficient energy at muzzle, the muzzle velocity of the bullet must exceed three times the supersonic level. In any event, the muzzle velocity is closely calculated and must not fall short of the calculated value.
[0008] If one would redesign this .223 cartridge so that with some reliability, its bullet would travel at a subsonic velocity, one would obtain a muzzle energy, which would run at only a tenth of its original muzzle energy. This would be a muzzle energy appropriate for a small bore weapon with weaker ammunition (subsonic munitions). However, this bullet would scarcely penetrate a notebook, and “bulletproof vest” could offer complete protective cover.
[0009] For today's military command organizations, the greatest possible repression of sounds emanating from firing is essential. To achieve such a goal, for the above reasons, no military weaponry can be employed, even when said weapons are equipped with silencers. Namely, either the sound of the firing is not silenced enough, or the effect of the shooting is insufficient. Now, it is entirely possible to make use of a submachine gun with a silencer, when the said gun fires on a closed breech basis and not, as is usual, from an open breech basis. With such a submachine gun, precision shots can be executed. It would be, however, better to employ the conventional military rifle for the use of such a silencer, as this weapon is already commercially available and need not be specially obtained. Further, the marksmen teams are familiar with the conventional weapon.
[0010] To accomplish this goal, one can provide the handgun with an exchangeable barrel for a large caliber cartridge. The reason for this, is that the larger caliber indicates a cartridge with a greater bullet weight, and consequently a greater muzzle energy, even in the subsonic velocity range. However, the earlier cited difficulties in military application are substituted for by new problems, namely the danger of erroneous cartridge switch. Here is an historic example:
[0011] In the first world war, the Mauser pistol, which already appeared on the market in 1896, was designed for the bottle cartridge 7.63 mm, but was converted to the 9 mm German Ordnance cartridge Parabellum. This conversion occurred only by use of another barrel, wherein however, the barrel for 7.63 mm and 9 mm were fully exchangeable. Other conversions and/or modifications were not necessary. Principally, a characteristic pistol stock became a recognition signal alerting that an exchange had been made.
[0012] In fact, inadvertent switches were often made, since either of the cartridges could be loaded into either pistol. If the 9.3 mm pistol were loaded with 7.63 mm cartridges, firing was still possible, but with reduced muzzle energy, accompanied by an erratic trajectory and loading difficulties. In the reverse situation, the 9 mm bullet squeezed itself through the 7.63 bore, and widened the bore, rendering it unuseable. Possibly, the bolts which limited the recoil travel for the breeching deformed as well.
[0013] Also, the earlier Mauser-cartridge 8×57 was modified several times, whereby, fundamentally, the cartridge with the smaller caliber (about 7×57) could be loaded into the bore intended for the larger caliber. In this case, the advantage was gained, that no direct damage to the weapon could be brought about. However, the accuracy of the gun, especially the sequential bull's-eye reliability was greatly reduced. If, for instance, the result of a commando raid depended on the results of a shot hitting its mark, then any inefficiency in the aim could not be accepted, especially when error can be attributed to a faulty loading of the weapon.
[0014] Based on the foregoing reasons, the disclosed device would provide a handheld firearm system, which would be free of the above difficulties.
SUMMARY OF THE INVENTION
[0015] A firearm system for the firing of bottle shaped cartridges from a firearm having an exchangeable barrel with a cartridge chamber and a breech closure, in accordance with the teachings of the present invention comprises an exchangeable barrel, which is designed for a bottle shaped cartridge with an essentially greater caliber than used in the original barrel of the firearm, wherein both cartridges have approximately the same length and same base measurements. The firearm system in accordance with the present invention has the feature that the bullet of the large caliber cartridge is so dimensioned, that if any effort is made to place the large caliber cartridge in the cartridge chamber of the bore for the smaller caliber, the said bullet will seat itself in the area of the cartridge section corresponding to the neck of the smaller cartridge and thereby prevent a complete insertion of the cartridge into the cartridge chamber. Additionally, the cartridge with the small caliber is so dimensioned, that any attempt to put the same into the cartridge chamber of the bore of the larger caliber, will result in its shoulder impinging against the shoulder of that section of the cartridge chamber corresponding to the larger caliber, or it will seat itself in front of this section, with the result that its complete insertion into the said cartridge chamber is prevented.
[0016] The shoulder of the large caliber cartridge is set back, in reference to the small caliber cartridge, or the large caliber cartridge exhibits at its shoulder a smaller diameter than does the small caliber cartridge, in other words, the large caliber cartridge is slimmer. The large caliber cartridge is preferably bottle shaped, but can also be slightly conical.
[0017] A cartridge that is placed in the wrong chamber will protrude from the non-fit cartridge chamber so far to the rear, that it remains unlatched by the oncoming breech block, and for this reason, the cartridge will not fire. Thus, only one barrel with, if required, a gas cylinder, silencer and munitions need be made available for the conversion of a handgun. These are parts, which, for little expense, can be purchased and kept available in the armory of a company.
[0018] The object of the disclosed device will be further explained with the aid of an embodiment presented in the accompanying schematic drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is an elevational cross sectional view of an exchangeable first barrel and a fragmentary view of a breech.
[0020] [0020]FIG. 2 is an elevational cross sectional view of an exchangeable second barrel and a fragmentary view of a breech.
[0021] [0021]FIG. 3 is a side elevational view of a first cartridge.
[0022] [0022]FIG. 4 is a side elevational view of the second cartridge.
[0023] [0023]FIG. 5 is the first cartridge of FIG. 3 inserted in the first barrel of FIG. 1
[0024] [0024]FIG. 6 is the second cartridge of FIG. 4 inserted in the second barrel of FIG. 2.
[0025] [0025]FIG. 7 is the first cartridge of FIG. 3 inserted in the second barrel of FIG. 2.
[0026] [0026]FIG. 8 is the second cartridge of FIG. 4 inserted in the first barrel of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Referring to FIG. 1, a breech 11 and an exchangeable first barrel 10 are shown. The first barrel 10 has a first cartridge chamber 12 , a breech end 14 , a shoulder 16 , and a first distance 18 defined from the breech end 14 to the shoulder 16 . Referring to FIG. 2, a breech 11 and an exchangeable second barrel 30 are shown. The second barrel 30 has a second cartridge chamber 32 , a breech end 34 , a shoulder 36 , and a second distance 38 defined from the breech end 34 to the shoulder 36 .
[0028] Referring to FIG. 3, a first cartridge 40 for use with the first barrel 10 is shown having a cartridge casing 42 , a circular base end 44 , a circular bullet-receiving end 46 , and a shoulder 48 defined by the narrowing of the cartridge casing 42 to a narrowing portion 50 . A bullet 52 is attached to the bullet-receiving end 46 of the cartridge casing 42 . Referring to FIG. 4, a second cartridge 60 , which has a larger caliber than the first cartridge 40 , for use with the second barrel 10 is shown having a cartridge casing 62 , a circular base end 64 , a circular bullet-receiving end 66 , and a shoulder 68 defined by the narrowing of the cartridge casing 62 to a narrowing portion 70 . A bullet 72 is attached to the bullet-receiving end 66 of the cartridge casing 62 .
[0029] Referring to FIG. 5, the first barrel 10 is sized to fully receive the first cartridge 40 in the first cartridge chamber 12 for detonation. When the first cartridge 40 is inserted in the first cartridge chamber 12 , the shoulder 16 of the first cartridge chamber 12 corresponds to the shoulder 48 of the first cartridge 40 .
[0030] Referring to FIG. 6, the second barrel 30 is sized to fully receive the second cartridge 60 in the second cartridge chamber 32 for detonation. When the second cartridge 60 is inserted in the second cartridge chamber 32 , the shoulder 36 of the second cartridge chamber 32 corresponds to the shoulder 68 of the second cartridge 60 .
[0031] Both cartridges 30 and 60 have the same overall length. Also, base ends 44 and 64 have the same dimensions. The first cartridge 40 and the second cartridge 60 , therefore, can be inserted into identical magazines. The distance 54 between the shoulder 48 and the base end 44 of the first cartridge 40 is longer than the distance 74 between the shoulder 68 and the base end 64 of the second cartridge 60 . Therefore, because the bullet 72 of the second cartridge 60 is longer than bullet 52 of the first cartridge 40 , the cartridge casing 62 of the second cartridge 60 is shorter than the cartridge casing 42 of the first cartridge 40 . Bullet 72 is a larger caliber bullet than bullet 52 and exhibits a substantial length over bullet 52 . For example, bullet 72 may have a caliber of 7.62 mm as compared to that of the bullet 52 , which may have a caliber of 5.56 mm, and bullet 72 may be between 12-15 g.
[0032] [0032]FIG. 7, shows the cartridge chamber 32 that is intended for the second cartridge 60 , but into which, as shown, the wrong cartridge has been introduced, namely the first cartridge 40 . The cartridge 40 rests with its shoulder 48 on the shoulder 36 of the second cartridge chamber 32 . Because the cartridge shoulder 48 is only appropriate for the cartridge chamber shoulder 16 of the first cartridge chamber 32 , base end 44 protrudes out of the breech end 34 of the second barrel 30 . Distance 38 of the cartridge chamber 32 is designed to fully receive the bullet 72 for breech closure or locking. Therefore, because the distance 54 of the cartridge casing 42 in longer than the distance 74 of the cartridge casing 62 , insertion of the cartridge 40 in the second cartridge chamber 32 results in base end 44 protruding out of the breech end 34 more than that required to close or lock the breech 11 . Breech 11 , which subsequently attempts to slide the first cartridge 40 into the second cartridge chamber 32 , ends its effort with a space between the breech end 34 of the second barrel 30 and the breech 11 . This space is greater than the greatest space, as well as the axial closing play, that a closed or locked breech will allow in any case. Therefore, because a firing pin in the breeching can only strike a cartridge upon full closing or locking, no firing can occur.
[0033] A reversed situation is shown in FIG. 8, depicting the cartridge chamber 12 for the first cartridge 40 , wherein the second cartridge 60 has been inserted. The second cartridge 60 , which is a large caliber cartridge, stops with the tip of its bullet 72 at the shoulder 36 of the first cartridge chamber 12 . Thus, the base end 64 of the second cartridge 60 protrudes farther out of the breech end 14 of the first cartridge chamber 12 than is permitted by the distance required to close or lock the breech 11 . Also in this case, the closure of the breech 11 comes to a stop, before the second cartridge 60 can be detonated.
[0034] Non-closure of the breech will be quite visible to a marksman. Therefore, the marksman must then recognize the error of putting the wrong cartridge into the cartridge chamber. This is best done, of course, before an enemy engagement, not while it is going on. DE 41 43 486 C2 has already disclosed a maneuver cartridge barrel, into which a live cartridge simply cannot be inserted. This possibility is not explained in the patent text. The maneuver cartridge can, however, in case of an exchange, be immediately loaded into the live ammunition barrel and also fired therefrom. This is contrary to the disclosed device, wherein a cartridge exchange is immediately recognizable and in no case can switched cartridges be fired.
[0035] Thus, a firing of the wrong cartridge, as is possible in the present state of the technology, is excluded.
[0036] Preferably, the first cartridge 40 exhibits a bullet 52 with a rounded tip and is furnished with a tombac sheathing. The second cartridge has a pointed bullet 72 which may be formed from a tipped steel core that is centrally inserted in the bullet 72 . The steel core prevents the bullet 72 from crumpling up and flattening out when it strikes a target. With the bullet 72 having a steel core, even light armor is still easily penetrable, in contrast to the conventional fully encased bullet of the same caliber and the same hitting power, but lacking the steel core.
[0037] The disclosed device, thus makes it possible to employ a modern, small caliber, rapid fire rifle in engagements, wherein the use of silencers is required and a suppression of the bullet sound is advantageous. With use of such a disclosed firing system, the hitting power of a submachine gun is achieved, and, because of the construction of the bullet, a decisive improvement is found in the penetrability of the firing.
[0038] Naturally, the disclosed device is principally appropriate to handguns, in which the barrel is simple to exchange. However the invented system can still be applied, although the barrel exchange meets with more complexities, in cases where a number of other weapons are rebuilt for long continuous usage or are so equipped from the start for the large caliber cartridges.
[0039] In large caliber cartridges, the shoulder, compared to that of the small caliber cartridges, is shortened to the rear, making the bullet essentially one diameter longer in the forward direction. The result is a very long, and consequently very heavy bullet.
[0040] Basing considerations on the fact that the larger caliber is about 2 mm larger than is the smaller, the conclusion must be drawn that the bullet weight is almost exactly four times the weight of the smaller caliber bullet. If this bullet is brought just barely into the subsonic range, then some 35 to 40% of the muzzle energy of the small caliber bullet is surrendered. This matches the muzzle energy of a heavy revolver. A bullet proof vest offers no protection from a direct hit by such a bullet.
[0041] For small caliber cartridges of the above mentioned kind, there exist repeating military rifles. Among these are, for instance, the sniper weapons of the East Germany. Such a weapon could be equipped with a changeable original barrel as well as an exchange barrel for large caliber cartridges and be further fitted with a silencer.
[0042] Preference is given, however, to a weapon system for use with the disclosed device, which includes a handgun designed with a gas pressure loader, and with which the bore is provided with a gas removal device (for instance, gas boring, cylinder for gas piston).
[0043] The existing barrel and the exchange barrel have their respective gas removal devices, thus the barrels are easily exchangeable. Accordingly, consideration has been given to the lessened gas pressure and altered gas pressure in the large caliber bore, by which the bullet is accelerated just barely under the supersonic level.
[0044] Moreover, the handgun for use with the disclosed device, is preferably designed as a rapid fire weapon, which as a standard weapon of a soldier is especially suited for commando task forces. The exchange of a barrel in a rapid-fire weapon does not bring about any significant weapon alteration procedures. The large caliber cartridges have the same length and the same base dimensions as the small caliber cartridges, the magazine remains unchanged, and all service elements and hand grips remain unchanged. Under certain circumstances it is advantageous to employ a modified visual sight, since the ballistics of the large caliber cartridges vary strongly from the ballistics of the small caliber cartridges.
[0045] The large caliber cartridge, can be a bottle shaped cartridge with a scarcely perceptible neck, or even a conically tapered cartridge without any neck. Essentially, especially in the latter case, the cone apex angle of the large caliber cartridge shell is larger than that of the small caliber cartridge shell. Thus, if the small caliber cartridge is erroneously placed in the cartridge chamber for the large caliber cartridge, it will not permit itself to be completely inserted. Where the large caliber cartridge is concerned, one should strive for a bullet with the greatest possible weight and, accordingly, the greatest possible caliber. In that effort, compromises may be made if a silencer or the like is already at hand, the caliber of which is somewhat smaller than the largest possible caliber which might have been obtained for the large caliber cartridge.
[0046] Such a large caliber bullet, because of its correspondingly large cross-section, has only a moderate penetration power. However, the said large bullet has a very high retention power on a living body, because the bullet transfers its entire kinetic energy to the said body.
[0047] Thus, a subsonic cartridge, in accord with the disclosed device, penetrates a “bulletproof vest” with a conventional 7.62 mm bullet. However, against the improved body protection favored now by NATO, which is made of 1.2 mm titanium sheet metal and 20 layers of Aramid fiber material (Kevlar), the said bullet is no longer effective, because it collapses or mushrooms against the titanium sheet metal. Further, against the said improved protection, the considerable cross section of the material is not fully penetrated but only tears and the bullet is retained by the Aramid fiber layer or slowed to the point of loss of effectiveness.
[0048] In order to overcome this disadvantage, in accord with the disclosed device, the bullet of the large caliber cartridge is a pointed bullet, even though, such a bullet as compared to a blunted or softly rounded bullet has a lesser weight. With the sharpened point, upon impact, the point brings against the titanium so high a loading per cross-sectional area, that a small area penetration can be made. Subsequently, the pressure of the remaining body of the bullet in a forward direction, splits the penetrated point apart with little loss in energy. Even the Aramid fibers do not need to be separated over the entire cross-section of the bullet, but are pressed randomly and with little energy expenditure away from one another by the pointed bullet tip.
[0049] To penetrate the Aramid fiber layers, a core is placed in the bullet, which forms the said point and which is made of tungsten carbide or preferentially, steel. Such a point remains practically undeformed upon striking titanium sheet and separates the Aramid fibers without difficulty.
[0050] It will be understood that the above description does not limit the invention to the above-given details. It is contemplated that various modifications and substitutions can be made without departing from the spirit and scope of the following claims.
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A system for firing either a first cartridge or a second cartridge from a handgun, the first and second cartridges having dissimilar calibers. The system includes a first barrel removably mounted to the handgun, with the first barrel including a first cartridge chamber sized to permit placement of the first cartridge into the first barrel in a firing position. The first cartridge chamber is sized to prevent placement of the second cartridge into the first cartridge chamber in the firing position. A second barrel is provided, which is interchangeable with the first barrel and which is also removably mounted to the handgun. The second barrel includes a second cartridge chamber sized to permit placement of the second cartridge into the second barrel in a firing position, and the second cartridge chamber is sized to prevent placement of the first cartridge into the second cartridge chamber in the firing position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to fourdrinier paper machines. More specifically, the present invention relates to assembly design and material selection for deckle structures used to confine a papermaking stock pond carried on a fourdrinier screen.
2. Description of the Prior Art
Fourdrinier paper machines are characterized by a closed loop web formation screen driven over an open, flat table surface. Extremely dilute, aqueous papermaking stock is jetted upon the traveling screen from a horizontally elongated nozzle; usually associated with a stock accumulation chamber called a headbox.
As the traveling screen carries the stock flow from the slice jet landing zone, aqueous vehicle, i.e., water, drains through the screen to leave the fiber constituent of the papermaking stock accumulated upon the upper screen surface as a consolidated mat.
Between the stock landing zone and that longitudinally displaced point along the screen belt traveling route whereat the mat consolidates into a paper web, the stock is supported on the screen surface as a liquid pond of diminishing depth. Without lateral containment, lateral liquid stock flow cross-directionally sweeps fiber stock towards the screen sides thereby undesirably tapering the paper web edge thickness.
To prevent such undesirable thickness tapering along the paper web edges, lateral pond confinement structures called "deckle boards" are positioned above and along the screen edges in the machine direction from the slice landing zone. Traditionally, deckle boards are similar to a pair longitudinal dams, each extending along the screen traveling direction respective to each lateral edge of the screen with the screen per se running under the deckle boards.
Elastomer skirts secured to the deckle board rigid structure drag against the underrunning screen for a partial fluid seal. To protect the screen from premature destruction, the elastomer is chosen to be significantly softer than the screen material.
A more recent innovation to the deckle structure has been to combine the deckle board with a screen edge cupping rail located outboard of the deckle board, as represented by U.S. Pat. No. 4,968,387 to R. L. Beran et al. The curled screen edges, traveling along respective, oppositely cupped rail profiles, hydraulically confine the stock pond. The deckle boards, internally of the cupped rails, are vertically positioned above the screen as to leave a substantial hydraulic channel beneath the lower deckle board edge. Machine white water fills the flow channel between the cupping rail and the outside surface of the deckle board. The inside faces of the deckle boards delineate the outer edge limits of the stock fiber. Standing waves generated in the stock pond are permitted to pass under the deckle board into white water channel and dissipate up the edge cup profile without reflection.
Although deckle boards that are operatively combined with screen edge cupping rails do not normally contact the screen, under certain production circumstances, the lower deckle edge is sufficiently close to the screen that frequent contact is inevitable. For this reason, need remains for a soft lower edge for the deckle blade.
Parallel developments have shown that the original generation of formation table deckle waves or waves which may develop from the trailing edge of a deckle blade may be substantially reduced or eliminated by extremely thin and smooth deckle blade construction. Unfortunately, most practical engineering materials that are sufficiently strong and rigid to be usefully thin and smooth are also much harder and tougher than the formation screen material. Consequently, use of thin, smooth deckle blades to eliminate forming table deckle waves has the potential for dramatically reducing the production life of the formation screen.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a thin, smooth deckle blade with a soft lower edge while satisfying all functional requirements.
Another object of the present invention is to secure a thin plate of polytetraflouroethylene (Teflon) between two polished surface plates of polycarbonate (Lexan).
Another object of the present invention is to provide an extremely reliable system for securing a laminated assembly of polytetraflouroethylene plate between polycarbonate plates.
These and other objects of the invention are accomplished by a composite deckle blade wherein the dominant wetted surface area of the blade is polished polycarbonate but projected below the external cladding of the polycarbonate blade sides is a polytetraflouroethylene blade edge.
A polymethylmethacrylate (Plexiglas) blade support structure is machined to fit an unusually clean surface frame mounting appliance. Stepped flats in the blade support body receive upper edges of the external cladding sides for a flush or smoothly transitioned exterior blade surface.
A spacing tongue between the steps secures a parallel separation dimension between the inside faces of the external cladding sides to receive the dimensioned thickness plate of polytetraflouroethylene. To secure the Teflon plate within this separation channel, transverse dowel pins of a material having adhesive compatibility with the cladding sides are inserted. Alternatively, expansion anchors or threaded compression pins may be used.
DESCRIPTION OF THE DRAWINGS
Relative to the drawings wherein like reference characters designate like or similar elements throughout the several figures of the drawings:
FIG. 1 is an abbreviated pictorial of a paper machine headbox section;
FIG. 2 is a detail of the invention in operative combination with a screen edge cupping rail;
FIG. 3 is an elevational detail of the present deckle blade assembly;
FIG. 4 is a bottom plan detail of the present deckle blade assembly;
FIG. 5 is a sectional detail of an alternative assembly pin structure; and
FIG. 6 is a sectional detail of another alternative assembly pin structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For environmental setting, FIG. 1 illustrates the relevant elements of a fourdrinier paper machine as comprising a headbox 10 which discharges dilute, aqueous papermaking stock from a slice opening 11 onto a horizontally carried, table segment of an endless belt screen 12. The screen is turned about and drawn from a breast roll 13 under headbox 10. Extensions 14 from the slice end wall, characterized as "pond sides" or "cheeking pieces," confine the fluid stock beyond the plane of discharge from the slice and may include the line of stock landing 15.
Dynamically, the jet of fluid stock lands upon the screen 12 which is moving at approximately the same horizontal velocity as the stock jet. Although drainage of the stock aqueous vehicle begins immediately, the initial drainage process continues for several seconds during which the stock remains as a highly fluidized pond 16. As this pond is carried away from the slice opening 11, water removal diminishes the pond depth until sufficient free water is removed to form a consolidated fibrous mat 18. That point of mat consolidation is observed on the paper machine as a "dry line" zone 17. Thus formed, the mat is further dried by pressure and heat to an integral, continuous paper web.
In transit, the pond 16 is laterally confined by deckling components such as the screen edge cupping rail 20 and the deckle board assembly 30 illustrated in section by FIG. 2. Although described in combination with the cupping rail 20, it should be understood that the present invention is not so limited and may be used independently.
In the preferred embodiment, the deckle board 30 is an assembly of two major components comprising the primary frame elements and the conveniently replaceable blade elements. Frame elements 31 and 35 are usually fabricated of steel or a suitable non-ferrous metal alloy whereas the blade elements are fabricated of selected, engineering plastics. The frame elements are rigidly secured to the paper machine structure by means such as that described by U.S. Pat. No. 3,607,624 and except for location trim adjustments, are not easily removable. The blade elements are designed to be expendable and easily replaced.
Primary frame element 31 is a flushing fountain comprising a square fluid conduit having a mid-line fluid flow barrier 32 flanked by conduit penetrating apertures 33.
Secured below the flushing fountain 31, by welding, for example, is square section C-clip 34 having guide rails 36 at the distal ends of suspension walls 35.
Guide rails 36 confine and support the expendable blade elements of the invention which include a support body 40 to which blade cladding plates 41 and 42 are secured as by adhesive bonding compounds. In support of a uniformly distributed flushing film over the blade surface, support body 40 is machined or molded with stepped areas 43 and 44 to receive a corresponding area of cladding plates 41 and 42 separated by a spacing tongue 45.
Cladding plate material suitable to provide necessary stiffness and rigidity may be polished polycarbonate (Lexan) whereas the support body 40 may be polymethylmethacrylante (Plexiglas). More generally, both plate and body materials should be of hard, tough polymer that may be polished to an exceedingly smooth surface and is dimensionally stable. Both plate and body may be Lexan or Plexiglas.
Between the two cladding plates 41 and 43 is a polytetrafluoroethylene (Teflon) soft blade plate 46 having a blade edge 47 projecting 1/2 inch to 1 inch below the lower edge of cladding plates 41 and 42. Although adhesive may be used on the interface between the cladding plates and the edge plate, the bond is usually less than reliable. Furthermore, the risk of adhesive bond failure is particularly great in the operating environment of a paper machine. Structural debris in a paper machine resulting from such adhesive bond failure is unacceptable due to the potential for great damage to fabrics, foils and other equipment or personnel. Accordingly, the blade assembly is secured by transverse shear pins 48 comprising dowels of a material that is adhesively compatible with the cladding plates 41 and 42.
Although the invention is presently perceived in the context of adhesively anchored shear pins, experience may provide that press-fit pins are sufficient. For removal and replacement of the polytetrafluoroethylene plate, secured by press-fit pins, only a drive or press punch is required. Dowel pins secured adhesively usually must be drilled away.
FIGS. 5 and 6 illustrate alternative embodiments of the present invention shear fasteners. In FIG. 5, the transverse pins 51 are of relatively soft polymer capable of force flow displacement. A countersunk screw 52 causes the pin 51 to grow by a volume directly proportional to the screw 52 volume.
The pin embodiment of FIG. 6 provides a two-part, reusable countersunk screw fastener 55 that can be set against a shoulder 56 to a predetermined length.
Note should be given to the preferred dimensional relationships wherein the total blade length is 10 to 15 feet long and the depth is 6 to 8 inches. Thickness of the blade, however, is on the order of 3/8 inch with the cladding plates 41 and 42 and soft blade plate 46 each being 1/8 inch thick.
The bottom plan view of FIG. 4 shows the blade trailing edge 49 to be tapered for the purpose of further minimizing pond flow disturbance and consequential wake generation.
Having fully disclosed our invention, numerous alternative and mechanically equivalent design configurations may be devised by those of ordinary skill in the art for particular invention features. As our invention, however,
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To protect the paper machine fourdrinier screen, deckle blades are fabricated with a soft polymer (polytetrafluoroethylene) lower edge having little adhesive affinity for either papermaking fiber or traditional plastic bonding compounds. Necessary structural rigidity is contributed to the assembly by a mechanical cladding of suitably stiff polymer plates that are adhesively bonded to a compatible plastic mounting body.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an engine stoppage notification apparatus.
Priority is claimed on Japanese Patent Application No. 2004-065850, filed Mar. 9, 2004, the content of which is incorporated herein by reference.
2. Description of Related Art
From the prior art, in a vehicle such as, for example, an automobile or a motorcycle or a scooter, in order to minimize the amount of exhaust gas which is emitted and the consumption of fuel, there have per se been known devices which stop the engine when the vehicle has ceased to move and the engine is idling, as when waiting at a traffic signal or during an episode of road congestion or the like, and which restart the engine from this idling stoppage state when the driver actuates the accelerator or releases the brake. A notification device is provided which notifies the driver of this engine stoppage during the idling stoppage state, and which thus also reassures the driver that this engine stoppage is not a malfunction (for example, refer to Japanese Patent Application, First Publication No. 2000-283010).
However, since the idling stoppage is performed provided that the idling stoppage conditions are fulfilled, even if, when for example waiting at a traffic signal or the like, it is clear to the driver of the vehicle that the signal will soon go to green, accordingly the intention of the driver to start off the vehicle and the timing of implementation of the idling stoppage may not correspond to one another and be mutually compatible, and there has been the problem that this imposes an undue burden upon the driver of the vehicle.
Furthermore if, even though the idling stoppage conditions are satisfied, the accelerator is again actuated for a second time during the time period from when the operation of the injector or injectors, and/or of the ignition, has been stopped in order to stop the engine to when the engine actually stops, then the problems occur that a burden of acceleration is imposed upon the engine which must restart again, and moreover a sense of discomfort is engendered in the driver, so that the product quality is deteriorated.
Thus, the objective of the present invention is to propose an engine stoppage notification apparatus, which is capable of alleviating the burden upon the driver of the vehicle by ensuring that the intention of the driver to start off the vehicle and the idling stoppage state correspond to one another and are mutually compatible, so that it is possible to anticipate enhancement of the product quality.
SUMMARY OF THE INVENTION
The present invention proposes an engine stoppage notification apparatus which is fitted to a vehicle including an engine, and which stops the engine when predetermined stoppage permission conditions are satisfied and starts the engine when predetermined restart permission conditions are satisfied, including a notification device which, from when the stoppage permission conditions are satisfied until the engine stops, issues a notification of the engine stoppage.
Since, according to the present invention as described above, the notification of the engine stoppage is provided from when the stoppage permission conditions for the engine are satisfied until the engine actually stops, accordingly it is possible for the driver to be aware of the engine stoppage in advance, and it is possible for him to make preparations for the engine stoppage. Therefore, it is possible to alleviate the burden upon the driver of the vehicle.
According to another aspect thereof, the present invention proposes an engine stoppage notification apparatus which is fitted to a vehicle including an engine, and which stops the engine when predetermined stoppage permission conditions are satisfied and starts the engine when predetermined restart permission conditions are satisfied, including: a sensor which detects the operational state of the vehicle; a stop permission determination device which determines whether or not the engine stoppage is permitted, based upon the detection signal from the sensor; a measurement device which measures a predetermined time period from the time point at which the stop permission determination device has determined that the engine stoppage is permitted; and a notification device which issues a notification of the engine stoppage, while the measurement device is measuring the predetermined time period.
According to the present invention as described above, the operational state of the vehicle is detected, and, based upon the result of this detection, a decision is made as to whether or not to permit the engine stoppage; and, if the operational state is such that the engine may be stopped, engine stoppage is permitted, the predetermined time period is measured from the time that the engine stoppage has thus been permitted, and after this predetermined time period has elapsed the engine is stopped. Since the notification of the engine stoppage is issued during the measurement of this predetermined time period, accordingly the driver is made aware of the engine stoppage in advance, so that he is able to make preparations for the engine stoppage. Therefore, it is possible to alleviate the burden upon the driver of the vehicle.
With the engine stoppage notification apparatus of the present invention, it is desirable for, after the engine has stopped, restarting of the engine to be prohibited while the predetermined time period is elapsing, irrespective of the presence or absence of the restart permission.
Since, according to the present invention as described above, restarting of the engine is not permitted until the predetermined time period has elapsed and the engine has completely stopped, accordingly it is possible to prevent imposition of a burden upon the engine due to restarting before it has completely stopped. Therefore, it is possible to enhance the product quality.
With the engine stoppage notification apparatus of the present invention, it is desirable for the notification device to be a display device which informs that the engine stoppage is imminent, from when the stoppage permission conditions are satisfied until the engine stops.
Since, according to the present invention as described above, the fact that the engine stoppage is imminent is displayed, accordingly it is possible for the driver of the vehicle to be visually aware that the engine stoppage is imminent. Therefore, it is possible further to alleviate the burden upon the driver of the vehicle.
Moreover, with the engine stoppage notification apparatus of the present invention, it is desirable for there to be further included a stoppage cancellation device which, from when the stoppage permission conditions are satisfied until the engine stops, is capable of cancellation of the engine stoppage.
According to the present invention as described above, if, even though the engine is stopped, it is clear to the driver of the vehicle that it will soon be required to restart it, such as for example when the vehicle is waiting at a signal or the like and it appears that the signal will shortly change to green, then it is possible for the driver of the vehicle to cancel the engine stoppage at any time without any sense of discomfort, even though the notification of the engine stoppage is being provided. Therefore, along with it being possible further to alleviate the burden upon the driver of the vehicle, it is also possible to further enhance the product quality.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an engine stoppage notification apparatus according to the first preferred embodiment of the present invention.
FIG. 2 is a flow chart of an engine stoppage procedure which is performed by the engine stoppage notification apparatus according to the first preferred embodiment of the present invention.
FIG. 3 is another flow chart of an engine stoppage procedure which is performed by the engine stoppage notification apparatus according to the first preferred embodiment of the present invention.
FIG. 4 is a flow chart of an engine stoppage decision procedure which is performed by the engine stoppage notification apparatus according to the first preferred embodiment of the present invention.
FIG. 5 is a flow chart of an engine restart procedure which is performed by the engine stoppage notification apparatus according to the first preferred embodiment of the present invention.
FIG. 6 is a timing chart of engine stoppage as performed by the engine stoppage notification apparatus according to the first preferred embodiment of the present invention.
FIG. 7 is a flow chart of an engine stoppage procedure which is performed by an engine stoppage notification apparatus according to the second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following, the first preferred embodiment of the present invention will be described with reference to the drawings.
In FIG. 1 , there is shown an engine stoppage notification apparatus 1 for a powered two wheel vehicle such as a scooter or the like. When stoppage permission conditions are satisfied and moreover the idling state is continuing, idling stoppage (hereinafter termed engine stoppage) is performed in which the engine ignition and fuel injection for the engine of this powered two wheel vehicle are stopped; and, when restart permission conditions such as for example accelerator actuation or the like are satisfied, the engine is restarted.
In this engine stoppage notification apparatus 1 , there is included a control device (an ECU) 2 which performs various types of control processing for the engine, a vehicle speed (V) sensor 3 , a throttle (TH) position sensor 4 , an revolution rate (NE) sensor 5 , an intake air pressure sensor 6 and the like are connected to the input (IN) side of the control device 2 . The detected vehicle speed signal from the vehicle speed sensor 3 is inputted to the control device 2 . The control device 2 makes a decision as to whether or not this powered two wheel vehicle is stopped, based upon this detected vehicle speed signal from the vehicle speed sensor 3 .
The detected throttle position signal from the throttle position sensor 4 is inputted to the control device 2 . The control device 2 detects the intention on the part of the driver to start off the vehicle based upon the result which is detected by this throttle position sensor 4 . In concrete terms, it detects whether or not the driver of this powered two wheel vehicle is performing accelerator actuation, based upon the detected throttle position signal from the throttle position sensor 4 .
The detected revolution rate signal from the revolution rate sensor 5 is inputted to the control device 2 . The control device 2 makes a decision as to whether or not the engine has been completely stopped (the revolution of the crank shaft has stopped). Furthermore, the negative pressure in the intake manifold which has been detected by the intake air pressure sensor 6 is inputted to the control device 2 . The control device 2 combines the result which is detected by the intake air pressure sensor 6 and the result which is detected by the throttle position sensor 4 , and makes an accurate decision as to the presence or absence of accelerator actuation by the driver of the vehicle.
The control device 2 is endowed with the function of acting as a stoppage permission determination device which, based upon the signals detected by the various sensors, decides whether or not the engine stoppage is permitted, and with the function of acting as a measurement device which measures a predetermined time period from the time point at which this stop permission determination device has permitted the engine stoppage. Furthermore, the control device 2 is endowed with the function of acting as a stoppage device which stops the engine after that predetermined time period has elapsed, and with the function of acting as a stoppage cancellation device which, from when the stoppage permission conditions are satisfied until the engine actually stops, is capable of canceling the engine stoppage.
The ignition (IG) 7 , an injector (INJ) 8 , a notification section (notification device) 9 , and a starter relay 10 are connected to the output (OUT) side of the control device 2 . The ignition 7 generates pulses for ignition of the engine, and supplies a voltage to an ignition plug which is fitted to the cylinder head of the engine. The injector 8 injects fuel to, for example, the combustion chamber or the intake manifold of the engine. The amount of the fuel which is injected from the injector 8 to the combustion chamber in this manner, and the timing of its injection, are controlled by the control device 2 .
The notification section 9 is a display device such as a lamp or the like, and is mounted to a meter panel upon which the speedometer of the vehicle and other display devices are fitted. This notification section 9 notifies the driver that the engine stoppage is imminent. In concrete terms, if for example the engine stops after ten seconds from when the stoppage permission conditions are satisfied, the notification section 9 may stimulate the attention of the driver by blinking from five seconds before the engine stops until the engine actually stops.
It should be understood that the notification section 9 may be located in any position, provided that its visibility is good; for example, it would also be acceptable to provide it upon a shield or the like in front of the meter panel.
The starter relay 10 is for putting into motion the starter motor which starts the vehicle. The opening and closing of the contacts of this starter relay 10 is controlled by the control device 2 .
In the following, the engine stoppage procedure which is executed by this first preferred embodiment of the present invention will be explained based upon the flow charts shown in FIGS. 2 through 5 , and upon the timing chart shown in FIG. 6 .
First, the engine stoppage procedure until the engine stoppage conditions are satisfied will be explained.
In step S 100 , a decision is made as to whether or not the engine stoppage procedure has been completed. If the result of the decision in step S 100 is NO (in other words, the engine stoppage procedure has not been completed), then the flow of control proceeds to step S 101 ; while, if the result of this decision is YES (in other words, the engine stoppage procedure has been completed), then the flow of control proceeds to step S 115 .
In step S 101 , an engine stoppage decision procedure shown in FIG. 4 is performed.
As shown in FIG. 4 , in step S 200 , a decision is made as to whether or not the vehicle speed is zero. If the result of the decision in step S 200 is YES (in other words, the vehicle speed is zero), then the flow of control proceeds to step S 201 ; while, if the result of this decision is NO (in other words, the vehicle speed is not zero), then the flow of control proceeds to step S 204 , in which the engine stoppage is set to “not permitted” and the flow of control returns.
In step S 201 , a decision is made as to whether or not the throttle (TH) position is the idling position. If the result of the decision in step S 201 is YES (in other words, the throttle position is the idling position), then the flow of control proceeds to step S 202 ; while, if the result of this decision is NO (in other words, the throttle position is not the idling position), then the flow of control again proceeds to step S 204 , in which, the engine stoppage is set to “not permitted” and the flow of control returns.
In step S 202 , a decision is made as to whether or not the revolution rate is the idling revolution rate. If the result of the decision in step S 202 is YES (in other words, the revolution rate is the idling revolution rate), then the flow of control proceeds to step S 203 , in which the engine stoppage is permitted and the flow of control returns. On the other hand, if the result of this decision is NO (in other words, the revolution rate is not the idling revolution rate), then the flow of control again proceeds to step S 204 , in which, again, the engine stoppage is set to “not permitted” and the flow of control returns.
Next, as shown in FIG. 2 , in step S 102 , a decision is made as to whether or not the engine stoppage is permitted. If the result of the decision is NO (in other words, if the engine stoppage is not permitted), then the flow of control proceeds to step S 113 ; while, if the result of this decision is YES (in other words, the engine stoppage is permitted), then the flow of control proceeds to step S 103 shown in FIG. 3 .
In step S 113 , a stoppage countdown is reset—in concrete terms, the value of a stoppage timer which performs this countdown is set to, for example, ten seconds—and then the flow of control proceeds to step S 114 .
In step S 114 , the notification section 9 is set to a notification cancellation mode (for example, it is turned off so as not to provide illumination), and then the flow of control proceeds to step S 112 shown in FIG. 3 . In step S 112 , the engine stoppage procedure is left unfinished—in other words, completion of the engine stoppage procedure is cancelled—and then the flow of control returns.
In other words, the above described procedures are repeated until the engine stoppage conditions hold (the engine stoppage conditions holding time point shown in FIG. 6 ).
When the engine stoppage is permitted in the above described step S 102 , the flow of control proceeds to step S 103 shown in FIG. 3 . In step S 103 the stoppage countdown is performed, in other words the value which has been set in the stoppage timer is decremented, and then the flow of control proceeds to step S 104 . In step S 104 , a decision is made as to whether or not the countdown has timed out. If the result of the decision is NO (in other words, the stoppage timer has not timed out), then the flow of control proceeds to step S 109 ; while, if the result of this decision is YES (in other words, the stoppage timer has timed out), then the flow of control proceeds to step S 105 .
Next, in step S 109 , a decision is made as to whether or not the countdown is directly before timeout (for example, five seconds). If the result of the decision in step S 109 is NO (in other words, it is not directly before timeout), then the flow of control proceeds to step S 110 ; while, if the result of this decision is YES (in other words, it is directly before timeout), then the flow of control proceeds to step S 111 .
In step S 110 , the notification section 9 is set to a normal notification mode (for example, “blink 1 ” in the first preferred notification embodiment shown in FIG. 6 ). On the other hand, in step S 111 , the notification section 9 is set to a directly before stoppage notification mode (for example, “blink 2 ” in the first preferred notification embodiment in FIG. 6 ). In step S 112 , as previously described, the flow of control returns with the engine stoppage procedure left unfinished.
In other words, as shown in FIG. 6 , from the time point that the engine stoppage conditions hold to the timeout time point, the notification section 9 shifts from the normal notification mode to the directly before stoppage notification mode, so that the driver is made aware that the engine will stop thereafter. The driver is able to cancel the engine stoppage at any time point until the timeout time point is arrived at. In concrete terms, if the driver intermittently moves the throttle grip, which is the accelerator, then, in the engine stoppage decision procedure subsequent to step S 101 , it is decided in step S 102 that engine stoppage is not permitted, and the stoppage countdown is reset in step S 113 , so that in step S 114 the notification section 9 is set to the notification cancellation mode, and the engine stoppage procedure is cancelled in step S 112 .
It should be understood that, apart from the throttle grip, it would also be acceptable to provide a dedicated switch for engine stoppage cancellation, so as to arrange for the engine stoppage to be cancelled by input from this dedicated cancellation switch.
When in the previously described step S 104 it has been detected that the countdown has timed out, then the flow of control proceeds to step S 105 . In step S 105 , fuel injection via the injector 8 and ignition via the ignition pulse output are stopped. In step S 106 the notification section 9 is set to the notification cancellation mode (for example, is turned off), and then the flow of control proceeds to step S 107 .
Since the time period from the timeout in step S 104 to the time point at which the fuel injection via the injector 8 and the ignition via the pulse output by the ignition 7 are stopped in step S 105 is an extremely short time period, accordingly, in the timing chart of FIG. 6 which will be described hereinafter, the instant of engine stoppage and the instant of timeout are shown as being the same time instant.
Next, in step S 107 , a decision is made as to whether or not the engine revolution has stopped. If the result of the decision in step S 107 is NO (in other words, the engine revolution has not stopped), then the flow of control proceeds to step S 112 ; while, if the result of this decision is YES (in other words, the engine revolution has stopped), then the flow of control proceeds to step S 108 .
It should be understood that, although it is shown in step S 106 that the notification cancellation mode (turned off) is set, it would also be acceptable for the notification section 9 to be turned, or blinked, provided that it is possible to recognize that this indicates engine stoppage (timeout).
In step S 112 , as described above, engine stoppage procedure unfinished is set, and the flow of control returns. On the other hand, in step S 108 , engine stoppage procedure completed is set, and, the flow of control returns.
In other words, while in step S 107 it is decided that the engine is not stopped, the ignition and fuel injection stoppage in step S 105 are maintained; while, when in step S 107 it is decided that the engine has stopped, then the flow of control proceeds to an engine restart procedure which will be described hereinafter, and here ignition and fuel injection are permitted.
In the previously described step S 100 , if it is decided that the engine stoppage procedure is completed, then the flow of control proceeds to step S 115 . In step S 115 , a decision is made as to whether or not the actuation of the starter relay has been completed. If the result of the decision in step S 115 is NO (in other words, the actuation of the starter relay has not been completed), then the flow of control proceeds to step S 116 ; while, if the result of this decision is YES (in other words, the actuation of the starter relay has been completed), then the flow of control proceeds to step S 101 , and the previously described engine stoppage decision procedure is repeated. In step S 116 , an engine restart procedure whose flow chart is shown in FIG. 5 is performed, and then the flow of control returns.
It should be understood that the notification mode of “blink 1 ” in step S 110 and the notification mode of “blink 2 ” in step S 111 are not to be considered as being limitative; provided that these two states can be distinguished from one another by the driver, any arrangement will be acceptable—for example, this notification may be performed according to whether the light is strongly or weakly illuminated. Furthermore, the notification cancelled mode of step S 114 is not limited to being shown by the light being turned off; it may alternatively be turned, or blinked.
Next, as shown in FIG. 5 , in step S 300 of the engine restart procedure, a decision is made as to whether or not the starter relay is ON. If the result of the decision in step S 300 is NO (in other words, the starter relay is not ON), then the flow of control proceeds to step S 301 ; while, if the result of this decision is YES (in other words, the starter relay is ON), then the flow of control proceeds to step S 309 .
Next, in step S 301 , a decision is made as to whether or not the throttle position is the idling position. If the result of the decision in step S 301 is YES (in other words, the throttle position is the idling position), then the flow of control proceeds to step S 302 ; while, if the result of this decision is NO (in other words, the throttle position is not the idling position), then the flow of control proceeds to step S 303 .
In step S 302 , the countdown for supplying electrical current to the starter relay 10 is reset. In other words, in step S 302 , an initial value is set as the set value of the time which protects the starter relay 10 .
In step S 308 , the non-completion of actuation of the starter relay is established, and then the flow of control returns.
After the previously described engine stoppage procedure completion in step S 108 has been established, when the driver of the vehicle temporarily actuates the throttle grip, which is the accelerator of the vehicle, in step S 301 it is determined that the throttle position is not the idling position, and the flow of control proceeds to step S 303 . In step S 303 , ignition and fuel injection are permitted, and then in the subsequent step S 304 a countdown is performed for electrical supply to the starter relay 10 , and then the flow of control proceeds to step S 305 .
In step S 305 , a decision is made as to whether or not the countdown for supply of electrical current to the starter relay 10 has timed out. If the result of the decision in step S 305 is NO (in other words, the countdown has not timed out), then the flow of control proceeds to step S 306 ; while, if the result of this decision is YES (in other words, the countdown has timed out), then the flow of control proceeds to step S 307 . In step S 306 , the starter relay 10 is turned ON, and then in step S 308 the non completion of the actuation of the starter relay 10 is established, and the flow of control returns. On the other hand, in step S 307 , the starter relay 10 is turned OFF, and then the flow of control returns via the above described procedure.
Next, since in step S 306 described previously the starter relay 10 is turned ON, it is determined in step S 300 that the starter relay 10 is ON, and the flow of control proceeds to step S 309 . In step S 309 , a decision is made as to whether or not the engine speed is above the complete firing revolution rate. If the result of the decision in step S 309 is YES (in other words, the engine speed is above the complete firing revolution rate), then the flow of control proceeds to step S 310 ; while, if the result of this decision is NO (in other words, the engine speed is below the complete firing revolution rate), then the flow of control proceeds to step S 304 and the above described procedure is repeated.
Here, by the complete firing revolution rate is meant the lower limit for revolution rate at which it is possible for the engine to restart its own revolution without aid from the starter motor.
In step S 310 the starter relay 10 is turned off, since it is taken that the engine has started because its engine speed is above the complete firing revolution rate. In next step S 311 the completion of actuation of the starter relay 10 is established and the flow of control returns. By the engine stoppage decision procedure of the previously described FIG. 4 flow chart, the engine stoppage becomes non-permitted, and the procedures before the engine stoppage conditions being satisfied are again repeated.
Accordingly, as shown in FIG. 6 , when for example the vehicle is waiting at a traffic signal and is stopped, engine stoppage is permitted and the stoppage timer starts to count down from the time point at which the engine stoppage conditions are satisfied, and the notification section 9 , which up until this time point has been turned off, starts to blink, as for example in the first preferred notification embodiment (in step S 110 ). Here, as in the first preferred notification embodiment of FIG. 6 , it would also be possible to establish the settings so as reliably to perform notification of the timeout to the driver of the vehicle by, for example, increasing the speed (in step S 111 ).
Both the fuel injection by the injector 8 and the pulse output by the ignition 7 are performed normally until the time point at which the stoppage timer times out (in step S 104 ), but, when that timeout time point arrives, both the fuel injection by the injector 8 and the pulse output by the ignition 7 are turned OFF (in step S 105 ). The blinking of the notification section 9 is turned off (in step S 111 ) until the timeout time point arrives. Here, during the interval from the timeout time point until the next time point, at which the revolution of the engine stops, the fuel injection by the injector 8 and the ignition by the pulse output of the ignition 7 are kept in the stopped state.
At the above described timeout time point when the fuel injection by the injector 8 and the ignition by the pulse output of the ignition 7 are stopped, the engine speed is gradually reduced, and, at the engine revolution stoppage time point, the engine speed has reliably reached zero. After this, the fuel injection by the injector 8 and the ignition by the pulse output of the ignition 7 are permitted (in step S 303 ).
At the restart time point such as when the signal goes to green or the like, the driver actuates the throttle grip which is the accelerator of this vehicle, since the throttle position becomes greater than the idling position, the engine stoppage permission shifts to engine stoppage non permission (in step S 101 ), the starter relay 10 goes to ON (in step S 306 ), and, at the same time as the cranking of the engine (in FIG. 5 , from the restart time point until the single dashed broken line), the fuel injection by the injector 8 and the pulse output of the ignition 7 are restarted, and the revolution rate rises above the complete firing revolution rate. The starter relay 10 goes to OFF, and the engine restarts and returns from the engine revolution stopped state.
Accordingly, with this first preferred embodiment, when the vehicle speed becomes zero due to waiting at a signal or the like, and also it is detected that the throttle position is equal to the idling position and moreover that the revolution rate is equal to the idling revolution rate, then automatic stoppage of the engine is permitted. Furthermore, when it is detected that the revolution rate has become zero but that the throttle position is not equal to the idling position, then the fuel injection by the injector 8 and the pulse output of the ignition 7 are permitted. Furthermore, when it is determined in step S 102 that engine stoppage is permitted, along with performing the countdown from the time point that the engine stoppage conditions are satisfied, this engine stoppage is notified during this countdown by the notification section 9 . Therefore, the driver of the vehicle is able to become aware of the engine stoppage in advance, and, since accordingly he is able to make preparations for the stopping of the engine, accordingly it is possible to alleviate the burden upon the driver.
During the time interval from when the fuel injection by the injector 8 and the ignition by the pulse output of the ignition 7 are stopped in step S 105 , until when the engine speed is completely stopped, irrespective of whether engine stoppage is permitted or is not permitted in steps S 203 and S 204 , the starter relay 10 does not go ON until the fuel injection by the injector 8 and the ignition by the pulse output of the ignition 7 are permitted in step S 303 . Since accordingly it is possible to prevent imposition of a burden upon the engine due to it being restarted before it has completely stopped. Therefore, it is possible to enhance the product quality.
Furthermore since, as shown in FIG. 6 , the driver of the vehicle is able to become aware of the fact that the engine stoppage is imminent due to the notification section 9 shifting from “blink 1 ” to “blink 2 ” during the time interval from when the engine stoppage conditions are satisfied until the timeout, accordingly it is possible further to alleviate the burden upon the driver.
Since, during the interval from when the engine stoppage permission has been determined in step S 102 until the operation of the injector 8 and of the ignition 7 have actually stopped, it is possible for input from the driver for canceling the engine stoppage to be received, accordingly it is possible to alleviate the burden upon the driver, and it is also possible to enhance the product quality. For example, if although the vehicle is stopped at a signal and waiting, it is clear that the signal will soon change to green, then even if the engine stops it will be necessary for it to restart immediately. Thus, the driver is able to perform the action of cancellation of the engine stoppage simply and easily, merely by actuating the throttle grip intermittently in consideration of the visual information which is provided to him by the notification section 9 .
Next, a second preferred embodiment of the present invention will be explained based upon the flow chart of FIG. 7 , and while referring to FIGS. 1 through 6 . It should be understood that, in the description of this second preferred embodiment, only the parts and features which are different from those in the first preferred embodiment described above, which are concentrated in the flow charts of FIG. 3 and FIG. 6 which deal with the preferred notification embodiment, will be explained, and repetitive discussion will be omitted. Although these procedures also show the engine stoppage procedure, just as in the first preferred embodiment described previously, the procedures of steps S 110 and S 111 of the first preferred embodiment described previously have been replaced by novel steps S 410 and S 411 , and step S 106 is omitted. In the following, these will be explained in order.
First, in the same manner as in the first preferred embodiment, the procedures from step S 100 to step S 104 are performed. Next, in step S 104 , a decision is made as to whether or not the countdown has timed out. If the result of the decision in step S 104 is NO (in other words, the countdown has not timed out), then the flow of control proceeds to step S 109 ; while, if the result of this decision is YES (in other words, the countdown has timed out), then the flow of control proceeds to step S 105 .
In step S 109 , a decision is made as to whether or not the countdown is directly before timeout. If the result of the decision in step S 109 is NO (in other words, the countdown is not directly before timeout), then the flow of control proceeds to step S 410 ; while, if the result of this decision is YES (in other words, the countdown is directly before timeout), then the flow of control proceeds to step S 411 .
In step S 410 , the notification section 9 is set to the normal notification mode (for example, the blinking of the second preferred notification embodiment in FIG. 6 ), and the flow of control proceeds to step S 112 . Furthermore, in subsequent step S 411 , the notification section 9 is set to the notification mode before stoppage (for example, the illumination of the preferred notification embodiment in FIG. 6 ), and then the flow of control proceeds to step S 112 .
In step S 105 the ignition and the fuel injection are stopped, and next in step S 107 a decision is made as to whether or not the engine revolution has stopped. After this the engine restart procedure of the FIG. 5 flow chart is terminated, and the illumination of this light is maintained, until returning to the procedure of step S 114 which sets the notification cancelled mode.
It should be understood that, as shown in the third preferred embodiment of FIG. 6 , it would also be acceptable to substitute illumination for the normal notification mode of step S 410 , and blinking for the notification mode just before stoppage of step S 411 .
Accordingly, with this second preferred embodiment of the present invention, in particular, it becomes possible to notify the driver, via the notification section 9 , of the fact that it is currently the interval from directly before the engine stoppage until the engine automatically restarts. Therefore, it is possible to enable the driver to recognize whether or not the engine has stopped abnormally, accordingly it is possible to alleviate the burden upon the driver.
It should be understood that the present invention is not to be considered as being limited to the above described preferred embodiments thereof; for example, it would also be acceptable to utilize it with a four wheeled vehicle upon which the engine is capable of automatic stoppage. Furthermore, it would also be acceptable to arrange for it to be possible to set any desired time period for setting the stoppage timer. Yet further, although the blinking display of the notification section 9 is shifted from “blinking 1 ” to “blinking 2 ” after five seconds from the time that the stoppage countdown started (in step S 103 ), this is not to be considered as being limitative of the present invention; it would also be acceptable to select any appropriate time period for thus shifting over the blinking display.
Even further, the method of display by the notification section 9 is not to be considered as limited to being blinking; it would also be possible to utilize any a device which provided such a display in any suitable format, provided that it enabled the driver of the vehicle to become aware that the timeout of the stoppage timer is imminent. Moreover, although in the shown embodiments of the present invention a display device such as a lamp or the like is employed as the notification section 9 , this is not to be considered as being limitative either; anything will be acceptable, provided that it enables the driver easily to become aware of the situation: for example, it would be acceptable to provide a notification via a liquid crystal display device, or via a LED, or aurally via a buzzer or the like.
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.
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The present invention provides an engine stoppage notification apparatus with which, due to its compatibility with and good correspondence to the intention of a driver to start off a vehicle and to stop and idle the vehicle, it is possible to anticipate the possibility of enhancement of product quality along with alleviation of the burden upon the driver. This engine stoppage notification apparatus notifies the driver that the engine is about to stop when the engine has satisfied certain predetermined stoppage permission conditions, and includes a notification device which, from when the stoppage permission conditions are satisfied until the engine stops, issues a notification of the engine stoppage.
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BACKGROUND OF THE INVENTION
The present invention relates to refrigeration chillers, to the compressors by which they are driven and to the lubrication thereof. With still more particularity, the present invention relates to refrigeration chillers driven by screw compressors and apparatus by which to ensure the immediate availability of lubricant to the compressor at chiller start-up.
The primary components of the refrigeration circuit of a refrigeration chiller include a compressor, a condenser, an expansion device and an evaporator. High pressure refrigerant gas is delivered from the compressor to the condenser where the refrigerant gas is cooled and condensed to the liquid state. The condensed high pressure refrigerant passes from the condenser to and through the expansion device. Passage of the refrigerant through the expansion device causes a pressure drop therein and the further cooling thereof. As a result, the refrigerant delivered from the expansion device to the evaporator is cool and is at relatively low pressure.
The refrigerant delivered to the evaporator is brought into heat exchange contact with a tube bundle disposed therein through which a relatively warmer heat transfer medium, such as water, flows. That medium will have been warmed by heat exchange contact with the heat load which it is the purpose of the refrigeration chiller to cool.
Heat exchange contact between the relatively cool refrigerant and the relatively warm heat transfer medium in the evaporator causes the refrigerant to vaporize and the heat transfer medium to be cooled. The now cooled medium is returned to the heat load to further cool it while the now heated, low pressure refrigerant is drawn out of the evaporator and into the compressor in the gaseous state for recompression and delivery to the condenser in a continuous process.
Where the compressor by which a refrigeration chiller is driven is a compressor of the screw type, it is typical that a relatively large amount of compressor lubricant will mix with the refrigerant gas undergoing compression therein and will be carried out of the compressor entrained in the stream of high pressure refrigerant gas discharged therefrom. To a somewhat lesser extent this is also the case in chillers driven by compressors of other than the screw type.
An oil separator will typically be disposed downstream of a screw compressor in a refrigeration chiller for the purpose of disentraining lubricant from the high pressure refrigerant gas in which it is carried out of the compressor. The disentrained oil settles into a sump within the oil separator. The relatively high pressure that exists within the oil separator is used to drive the disentrained lubricant from the sump back to the compressor for purposes such as bearing lubrication, sealing and cooling of the refrigerant gas undergoing compression therein.
Because the disentrained oil is exposed to the relatively high discharge pressure that exists in the oil separator and because it is at relatively high temperature, it will typically absorb and contain on the order of 30% by weight of the refrigerant from which it has been disentrained. When a screw compressor-driven refrigeration chiller is shut down under certain operating circumstances, particularly when operating at or near full load and such as during a power interruption or an emergency stop, the resulting precipitous pressure drop in the high pressure side of the chiller system causes the relatively violent outgassing of the absorbed refrigerant from the oil on that side of the system as well as the gas-driven reverse direction high speed rotation of the no longer motor-driven screw rotors. These effects result from the system's attempt, once it shuts down, to equalize pressures within itself across the compressor and expansion devices which generally define the boundaries of the high and low pressure sides of the refrigeration circuit within a chiller when it is in operation. Under such circumstances, the main oil line connecting the compressor and the sump in the oil separator can be blown dry.
Under such shutdown circumstances, provided that the conditions causing them are transient, the chiller system will attempt to restart relatively quickly after shutting down. If the oil feed line to the compressor has been blown dry, such re-starts can be unsuccessful due to the lack of a sensed supply of oil in the compressor supply line or can, if successful, potentially have the long term effect of damaging the compressor for intermittent lack of lubricant at start-up.
The need exists, in order to assure the long-term reliability of the compressor and to reduce or eliminate repeated unsuccessful attempted chiller re-starts and the service calls that can result therefrom under certain circumstances, for apparatus and/or a method by which to assure lubricant flow to a screw compressor in a refrigeration chiller shortly after chiller start-up even if the nature of the preceding chiller shutdown was such as to cause the oil supply line to the compressor to be blown dry.
SUMMARY OF THE INVENTION
It is an object of the present invention to ensure the availability of lubricant to a screw compressor employed in a refrigeration chiller at start-up irrespective of the conditions under which the chiller previously shut down.
It is another object of the present invention to assure the availability of lubricant to the screw compressor in a refrigeration chiller when it starts up even if the line by which lubricant is supplied to the compressor has been blown dry as a result of the nature of the previous shutdown of the chiller.
It is a still further object of the present invention to assure the supply of lubricant to a screw compressor in a refrigeration chiller, even after the supply line by which lubricant is delivered to the compressor has been blown dry during the previous chiller shutdown, without the need or use of moving parts or controls dedicated to that purpose.
It is another object of the present invention to assure that lubricant is delivered to a screw compressor in a refrigeration chiller shortly after start-up, irrespective of the circumstances of the previous compressor shutdown, so as to both ensure long term compressor reliability and to eliminate repeated failed chiller starts that can occur if lubricant availability to the compressor cannot be confirmed shortly after a compressor re-start is attempted.
These and other objects of the present invention, which will better be appreciated and understood by reference to the following Description of the Preferred Embodiment and the accompanying drawing figures, are accomplished in a screw compressor-driven refrigeration chiller which has a lubricant reservoir connected in parallel with the main line by which lubricant is supplied to the compressor during normal operation. When the main compressor lubricant supply line is blown dry, as can occur under certain chiller shutdown circumstances, it is immediately re-filled out of the reservoir. The reservoir remains sufficiently filled with lubricant, even after the oil supply line has been blown dry, to accomplish the purpose of re-filling a critical portion thereof. Once emptied, the reservoir is re-filled as the chiller next starts up and remains filled until such time as the main compressor lubricant supply line is again blown dry. In chiller systems in which a sensor is used to ensure the availability of lubricant to the compressor in a timely manner after a chiller start-up, providing for the immediate refilling of the main lubricant supply line, even after it has been blown dry, assures that the chiller will not be subject to repeated failed starts as a result of the failure of the sensor to sense lubricant in the critical chiller lubricant supply line location.
DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a schematic illustration of the refrigeration chiller of the present invention.
FIG. 2 is an illustration of the apparatus of the present invention by which the supply of lubricant to the compressor of the chiller of FIG. 1 is assured.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, chiller system 10 includes a compressor 12, in oil separator 14, a condenser 16, an expansion valve 18 and an evaporator 20. All of these components are serially connected as a circuit for refrigerant flow as will more thoroughly be described.
Compressor 12 is, in the preferred embodiment, a compressor of the screw type in which screw rotors 22 and 24 are meshingly engaged in a working chamber 26. In a screw compressor of the type illustrated in FIG. 1, one of the screw rotors of compressor 12 is driven by a motor 28 when the chiller is in operation. Refrigerant gas is drawn into working chamber 26 of the compressor from evaporator 20 through suction area 30 of the compressor and is compressed by the intermeshing counter-rotation of the motor-driven screw rotors therein. The compressed gas is discharged from the working chamber 26 of the compressor into discharge area 32 thereof at significantly increased pressure and temperature.
By their nature, refrigeration screw compressors often require the delivery of a significant quantity of lubricant to them for multiple purposes, most typically associated with compressor lubrication, sealing and/or cooling needs. After or during its use for these purposes, the lubricant typically makes its way into the compressor's working chamber. Lubricant is driven to the locations of its use by the pressure differential that exists between the oil separator 14, which is at discharge pressure when the chiller is in operation and which is the source of the lubricant, and the relatively lower pressure locations of its use within the compressor.
The amount of lubricant that becomes entrained in the refrigerant gas flowing through the compressor's working chamber is significant. Such oil is carried out of the compressor to the oil separator where it is disentrained and drains to sump 34 therein. Because oil separator 14 and sump 34 are at discharge pressure and because the refrigerant gas and oil therein are relatively hot when the chiller is in operation, the oil in sump 34 of the oil separator can, because of such pressures and temperatures, contain on the order of 30% by weight of absorbed refrigerant.
The discharge pressure that exists internal of oil separator 14 drives lubricant from sump 34 through line 36 to, for instance, bearings 38 and 40 of the compressor and to oil injection port 42 which opens into the compressor's working chamber. The lubricant injected directly into the working chamber of the compressor and into the gas undergoing pressure therein through port 42 cools the refrigerant in the working chamber and/or provides a seal between the screw rotors and the inner wall of the working chamber. The lubricant directed to the bearings provides for the lubrication thereof.
Referring additionally now to FIG. 2, chiller 10, in the preferred embodiment of the present invention, is provided with apparatus by which to assure that lubricant is made available to the compressor shortly after start-up and, in particular, is quickly made available to the compressor oil injection port even under the circumstance that the previous shutdown of the compressor and chiller system has caused the lubricant supply line leading from the oil separator to the injection port to be blown dry. In that regard, lubricant supply line 36 includes a first tee-section 44, a second tee-section 46, a section of piping 48 connecting the two tee-sections and a sensor block 50 that defines a flow path 52 through it which is in communication with a sensor 54. Lubricant is delivered from sump 34 of the oil separator to first tee-section 44 through piping section 56 of supply line 36. After next flowing through piping section 48, tee section 46 and flow path 52 of sensor block 50, the lubricant is delivered to the injection port of the compressor through piping section 58 which, during normal chiller operation and subsequent to normal chiller shutdowns, will typically retain and contain lubricant due to the importance of its purpose and/or its physical location in the context of the chiller assembly.
Piping section 66, which branches off from tee-section 46, may feed less critical compressor locations or may feed compressor locations that are less affected by blow-back through lubricant supply line 36, should it occur, due to its geometry and/or location in the context of the chiller assembly and/or due to the fact that it connects to the main line running from the sump in oil separator 14 to the compressor via a "tee". It is to be noted that in certain chiller designs and lubrication systems, second tee-section 46 may not exist at all or only a single line or more than two oil lines may feed lubricant to the compressor. Further, the compressor location fed by line 58 may be other than an injection port. All such possibilities are contemplated and fall within the scope of the present invention.
A lubricant reservoir 60 is in flow communication with first tee-section 44 and line 36 via conduit 62 and is likewise in flow communication with section 58 of lubricant supply line 36 through drain line 64. Reservoir 60, in the preferred embodiment, is sized so as to hold from 1.5 to 2.0 times the volume of lubricant that will typically reside in section 58 of the lubricant supply line. Conduit 62, through which lubricant flows into reservoir 60, is sized such that reservoir 60 fills, when empty, relatively quickly, preferably without diverting more than approximately 10 to 15 percent of the total oil flow through line 36 during the fill process. Drain line 64, on the other hand, is a much smaller line with the ratio between the flow areas through conduit 62 and through drain line 64 being, in the preferred embodiment, on the order or 16:1. By use of this ratio, reservoir 60, if empty, is, in the preferred embodiment, caused to be filled within about 45 seconds of a compressor re-start.
Under normal operating conditions, reservoir 60 remains filled because the rate at which it is filled, when oil is flowing through lubricant supply line 36, is greater than the rate at which lubricant drains out of reservoir 60 to section 58 of that lubricant supply line through drain line 64. Because of the free-flow relationship between reservoir 60 and the oil supply line through conduit 62 and drain line 64, some drainage and re-filling of the reservoir will continuously occur as oil flows through line 36. The rate/amount of drainage and re-filling will, however, be relatively small given the size of drain line 64.
Under the circumstance where section 58 of lubricant supply line 36 is dry and the pressure therein is such as to allow reservoir 60 to drain to it through drain line 64, the sizing of drain line 64 is such that it takes, in the preferred embodiment, approximately one minute for reservoir 60 to drain to and fill piping section 58. It is to be understood that reference to a "dry" lubricant supply line herein is not necessarily meant to suggest complete dryness of the line or that the line is entirely devoid of oil. It is only meant to convey the circumstance that much of the lubricant that would normally be found in the line has, for some reason, been displaced therefrom.
Under certain chiller shutdown circumstances, pressures within the chiller system, including those within the compressor, the oil separator and supply line 36, can and do change dramatically and quickly. Such conditions typically occur when the chiller shuts down under full or near full load, often due to a power interruption or another system condition that causes an emergency chiller shutdown. Such pressure transients most often last only on the order of 15 to 20 seconds. However, during such transient conditions, system pressures may be such as to cause the lubricant normally contained in lubricant supply line 36 to be blown thereoutof and back to the oil separator which, under such conditions, can momentarily be at a relatively lower pressure than the compressor locations it normally feeds.
Even during such transient pressure conditions oil will, in fact, be metered into section 58 of oil supply line 36 from reservoir 60 through drain line 64 because reservoir 60 is, once again, in open communication with line 36 through both conduit 62 and drain line 64. However, the amount of lubricant that drains into section 58 of the oil supply line under any circumstance, including this one, is limited by the size of drain line 64. Reservoir 60 is, accordingly, sized to account for the lubricant that will drain thereoutof through drain line 64 while transient pressure conditions exist and will, after such transient conditions subside, contain sufficient lubricant to essentially fill oil supply line 58 even if it has been blown dry. As a result, lubricant is immediately available in section 58 of the lubricant supply line when the chiller next attempts to start. This ensures that critical compressor locations are quickly supplied with lubricant, even if line 36 has been blown dry as a result of the circumstances of the preceding chiller shutdown, and assures that the re-start will be permitted to continue as a result of the existence and sensing of lubricant in section 58 by sensor 54.
Of significance with respect to the present invention is the fact that an assured supply of lubricant is provided to the compressor, even under circumstances where the lubricant supply line has been blown dry due to the nature of the preceding chiller shutdown, without the need for any proactive control of the process by which the assured supply of lubricant is provided and without the need for moving parts. This is because the reservoir is replenished from and drains to the lubricant supply line via a flow path that is continuous and unobstructed.
Also, in chiller systems where part of the chiller protection scheme includes the use of a sensor the purpose of which is to sense the existence of lubricant in the main lubricant supply line by which the compressor is fed, failure of the sensor to sense the existence of lubricant in the supply line when the chiller next attempts to start after the main lubricant supply line has been blown dry can cause repetitive compressor re-start failures and result in service calls. In the preferred embodiment of the present invention, sensor 54 is an optical sensor connected to chiller controller 68 which must optically sense the presence of a liquid within section 58 of the main lubricant supply line or controller 68 will not permit the chiller to start. Such failed re-starts and the need for such calls are, to a great extent, eliminated by the employment of the reservoir system of the present invention. Therefore, not only is the long-term reliability of the compressor enhanced by the present invention but the likelihood of repetitive failed re-starts and the need for service calls relating thereto is to a great extent reduced or eliminated.
While the present invention has been described in terms of a preferred embodiment, it will be appreciated that many modifications thereto will be apparent to those skilled in the art. In particular, it will be apparent that the apparatus of the present invention, while primarily designed for and used in refrigeration chillers driven by screw compressors, has application in a wide variety of compressor systems where there is a need to assure and prove lubricant flow to the compressor under circumstances where the compressor's oil supply line may have been blown dry or otherwise have been caused to drain, such as a result of the circumstance of the preceding compressor shutdown.
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An assured supply of lubricant to the compressor in a refrigeration chiller is provided by a reservoir that is connected in parallel with the main line by which lubricant is supplied to the compressor. The reservoir is connected to the main lubricant supply line in a manner such that if the lubricant supply line is blown dry, as can occur as a result of an unusual or abnormal chiller shutdown condition, a critical portion of the supply line will be refilled by the reservoir relatively very quickly which assures the immediate availability of lubricant to the compressor from that portion of the lubricant supply line when it next starts up.
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This is a divisional of application(s) Ser. No. 08/138,907, filed on Oct. 18, 1993, now U.S. Pat. No. 5,533,833 which was a FWC of Ser. No. 07/968,557, filed on Oct. 29, 1992, (now abandoned).
FIELD OF THE INVENTION
The present invention relates generally to melt spinning synthetic polymeric fibers. More particularly, the present invention relates to apparatus for distributing molten polymer flow to the backhole of a spinneret.
BACKGROUND OF THE INVENTION
As used herein, the term "regular geometric shape" refers to the common two-dimensional shapes of a rectangle, square, oval, circle, triangle or other similar ordinary shape.
Thin distribution flow plates having complex distribution flow patterns formed on one surface thereof accompanied by through holes are known. Distribution flow plates of that type improve flexibility and melt flow processing when compared to the state of the art at the time of that invention. Such plates are disclosed in co-owned U.S. Pat. No. 5,162,074 issued Nov. 10, 1992, "Profiled Multi-Component Fibers and Method and Apparatus for Making Same".
Although thin distribution flow plates having complex flow patterns provide many advantages, additional advantages are available when the multiple functions of these thin plates are split up so that only a single function is performed in a single thin plate. This allows mixing and matching of functions by interchanging only one or more of the single function plates within a stack of plates. For example, by changing one or more of the single function plates, the resulting fiber's cross-section can be changed from sheath/core to side-by-side without modification of the other spin pack parts.
French Patent No. 2,429,274 discloses a stack of thin plates useable to combine distinct polymer streams prior to the backhole of a spinneret. Each backhole requires its own stack of plates although the stacks may be interconnected. Because they result in polymer stream mixing, these plates are unsuitable for forming many cross-sections, for example, sheath core.
SUMMARY OF THE INVENTION
Accordingly, the present invention is a spin pack for spinning synthetic fibers from two or more liquid polymer streams including means for supplying at least two polymer streams to the spin pack, a spinneret having extrusion orifices and flow distribution plate sets. The flow distribution plate sets include at least one patterned plate having edges which define a substantially regular two-dimensional geometric shape, a substantially planar upstream surface, a substantially planar downstream surface and at least one flow distribution pattern stenciled therein by cutting through. The flow distribution pattern connects the upstream surface with the downstream surface. The flow distribution plate sets further include, for each patterned plate, at least one boundary plate stacked sealingly adjacent thereto and having edges which define a substantially regular geometric shape, a substantially planar upstream surface and a substantially planar downstream surface. The boundary plate has cut-through holes connecting the upstream surface with the downstream surface to form at least one flow-through channel to allow fluid flow through the patterned plate and otherwise is substantially solid with solid portions where the patterned plate is cut through to accomplish fluid flow in a direction transverse to the flow in the flow-through channel. The liquid polymer streams flow as discrete streams through the flow distribution plate sets to the spinneret.
Another aspect of the present invention is a process for spinning fibers from synthetic polymers (a) feeding at least one liquid polymer to a spin pack; and (b) in the spin pack, routing the at least one polymer to at least one patterned plate having edges defining a substantially regular two-dimensional geometric shape, a substantially planar upstream surface, a substantially planar downstream surface and at least one flow distribution pattern stenciled therein by cutting through. The flow distribution pattern connects the upstream surface with the downstream surface. Each patterned plate has at least one corresponding boundary plate stacked sealingly adjacent thereto and has edges which define a substantially regular geometric shape, a substantially planar upstream surface and a substantially planar downstream surface. The boundary plate has cut-through holes connecting the upstream surface with the downstream surface to form at least one flow-through channel to allow fluid flow through the patterned plate and otherwise is substantially solid with solid portions where the patterned plate is cut through to accomplish fluid flow in a direction transverse to the flow in the flow-through channel. The liquid polymer streams flow as discrete streams through flow distribution channels formed by the at least one patterned plate and the at least one corresponding boundary plate to the spinneret. The polymer is extruded into fibrous strands.
A still further aspect of the present invention is a method of assembling a flow distribution plate for distributing at least two discreet molten polymer streams to a spinneret comprising: (a) stenciling a pattern in at least one first plate such that the first plate has edges which define a substantially regular two-dimensional geometric shape, a substantially planar upstream surface, a substantially planar downstream surface and at least one flow distribution pattern stenciled therein by cutting through. The flow distribution pattern connects the upstream surface with the downstream surface. The first plate is then stacked sealingly adjacent to a second plate which has edges which define a substantially regular geometric shape, a substantially planar upstream surface and a substantially planar downstream surface. The boundary plate has cut-through holes connecting the upstream surface with the downstream surface to form at least one flow-through channel to allow fluid flow through the patterned plate and otherwise is substantially solid with solid portions where the patterned plate is cut through to accomplish fluid flow in a direction transverse to the flow in the flow-through channel. The liquid polymer streams flow as discrete streams through the flow distribution plate sets to the spinneret.
It is an object of the present invention to provide a versatile flow distribution apparatus for melt spinning synthetic fibers.
Another object of the present invention is a versatile process for melt spinning synthetic fibers.
A further object of the present invention is to provide a method for assembling distribution flow apparatus.
Related objects and advantages will be apparent to those ordinarily skilled in the art after reading the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away perspective view of a spin pack assembly for making sheath/core type fibers and incorporating flow distribution plate sets of the present invention.
FIG. 2 is an elevational cross-sectional view of the polymer inlet of FIG. 1 taken along line 2--2 and looking in the direction of the arrows.
FIG. 3 is an elevational cross-sectional view of the polymer inlet block of FIG. 1 taken along line 3--3 in FIG. 1.
FIG. 4 is the top plan view of a dual-function pattern and boundary plate of FIG. 1 according to the present invention.
FIG. 5 is the top plan view of a boundary plate of FIG. 1 according to the present invention.
FIG. 6 is the top plan view of a pattern plate of FIG. 1 according to the present invention.
FIG. 7 is a partial cross-sectional view of three stacked plates according to the present invention.
FIG. 8 is an exploded view of two plates from a spin pack showing an alternate configuration of the present invention.
FIG. 9 is the partial cross-sectional view of FIG. 7, showing an optional filtering insert.
FIG. 10 is a partial cross-section similar to FIG. 7 but showing an alternate optional filtering insert.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To promote an understanding of the principles of the present invention, descriptions of specific embodiments of the invention follow and specific language describes the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and that such alterations and further modifications, and such further applications of the principles of the invention as discussed are contemplated as would normally occur to one ordinarily skilled in the art to which the invention pertains.
The present invention involves thin plates having polymer flow holes and channels cut through them. These plates have substantially planar upstream and downstream surfaces that form substantially regular geometric shapes. A stack of two or more of these plates can be used in forming multicomponent fibers or mixed component yarns having various cross-sections. These plates are inexpensive and disposable, and have a high degree of design flexibility. The flow holes and channels may be cut through using electro-discharge machining (EDM), drilling, cutting (including laser cutting) or stamping. Preferable machining techniques are those which allow for a wide selection of plate materials so long as the materials do not creep under the spinning conditions and do not adversely react with the polymers. Possible materials include both ferrous and non-ferrous metals, ceramics and high temperature thermoplastics. The high temperature thermoplastics can even be injection molded. While methods for machining, eroding, stamping, injecting, etc., are readily available in the art, for convenience, an example of how a plate may be made is provided in Example 1.
The thin distribution flow plate sets of the present invention include pattern plates and boundary plates. Unlike other comparable thin distribution plates, the disclosed pattern plates have transverse channels cut completely through from the upstream surface to the downstream surface. The surface of the next adjacent downstream plate serves as the bottom or boundary of the flow channel. Therefore, each thin plate contains only one feature, i.e., arrangement of channels and holes to distribute melt flow in a predetermined manner. Greater flexibility relative to other more complicated flow distribution plates is provided.
Referring to FIG. 1, a spin pack assembly constructed in accordance with the present invention and designed to produce sheath/core bicomponent fibers of round cross section is illustrated. Assembly 10 includes the following plates sealingly adjoining each other: polymer inlet block 11; metering plate 12; first pattern plate 13; boundary plate 14; second pattern plate 15 and spinneret plate 16. Fluid flow is from inlet block 11 to spinneret plate 16. The parts of the assembly may be bolted together and to the spinning equipment by means of bolt holes 19. Polymer inlet block 11 includes holes for receiving each type of polymer being extruded. In this example there are two polymers, sheath and core, so that two polymer inlet orifices 17 and 18 are shown.
Downstream of polymer inlet block 11 is metering plate 12 which contains metering holes 22 and 23 which receive polymer from core channels 20 and sheath channel 21, respectively. Metering holes 22 receive core polymer from distribution channels 20 (FIG. 2) and route it to distribution slot 24 cut-through first pattern plate 13. Metering holes 23 receive polymer from sheath distribution channel 21 (FIG. 2) and convey it to holes 25 cut through first pattern plate 13 and to holes 27 cut through boundary plate 14 which sealingly adjoins first pattern plate 13.
The top surface of boundary plate 14 confines the core polymer within cut channel 24 whereby the core polymer fills channel 24 and is forced to exit through cut hole 26 in boundary plate 14. Boundary plate 14 has a regular two-dimensional shape, i.e., a rectangle.
Pattern plate 15 has a regular two-dimensional shape, i.e., a rectangle, and has star shaped holes cut through its thickness. The center of the star aligns with the center of backhole 29 of spinning orifice 30 in spinneret plate 16. The four corners of star holes 28 are located outside the perimeter of backhole 29. Sheath polymer streams from holes 27 in boundary plate 14 flow into the corners of star holes 28. Because the bottom surface of boundary plate 14 confines the streams to star holes 28, the sheath streams flow laterally into the backhole 29. Therefore, boundary plate 14 forms the lower boundary for channel 24 and the upper boundary for star hole 28. The core polymer stream from hole 26 of plate 14 flows into the center of star hole 28 and down into backhole 29 where it is surrounded by sheath streams. The combined flow issues from spinning orifices 30 to form round bicomponent fibers.
As will be recognized by the ordinarily skilled, molten polymers may be fed to the assembly by any suitable conventional means. Molten core polymer enters the assembly through polymer inlet 17 shown in the elevational cross-section of FIG. 2. Inlet 17 splits into feed legs 31 and 32 which feed the two main distribution channels 20. Molten sheath polymer enters through inlet 18 shown in the elevational cross-section of FIG. 3 and flows to main distribution channel 21.
FIG. 7 further illustrates the general principle of the present invention. Shown in FIG. 7 are three plates of a spin pack in partial cross-section. These plates illustrate the boundary/pattern plate concept. As shown, plates 111 and 112 are boundary plates and plate 113 is a pattern plate. Polymer flow is in the direction of arrows P. Polymer passes through the cut-through portion (through hole 115) because through hole 115 overlaps pattern 117 in plate 113. Pattern 117 allows transverse flow of the polymer, i.e., transverse to the polymer flow in the through hole 115, of the polymer because a horizontal flow channel 118 is formed by the faces 121 and 123 of boundary plates 111 and 112, respectively. The horizontal flow path directs the polymer to through hole 125 because hole 125 overlaps with pattern 117.
It will be readily apparent to those who are ordinarily skilled in this art that the shape of the pattern and boundary holes may vary widely so long as any portion of the cut-through parts on adjacent plates overlap. Also, certain plates may perform both boundary and pattern functions. This concept is illustrated in FIG. 8. FIG. 8 shows in exploded partial elevational perspective view of dual function plates 211 and 213. Upper dual function plate 211 has elongated slots 215 cut through its thickness.
Lower dual function plate 213 also has elongated slots 216 cut through its thickness. Immediately adjacent slots 215 and 216 overlap so that they are in fluid flow communication. Yet, these slots are oriented at 90° relative to each other so that polymer passing from slot 215 into slot 216 will change its course by 90°.
Optionally, filtering parts may be incorporated into the apparatus. For example, porous metal inserts may be placed within the cut of a pattern plate. As shown in FIG. 9, porous metal insert 310 has the dimensions of cut (pattern) 117 in plate 113. Polymer flow (P) passing through porous metal insert 310 will be filtered.
An alternative method for filtering is shown in FIG. 10. Porous plate 410 is inserted between pattern plate 113 and boundary plate 112. Polymer flow (P) passing through porous plate 410 will be filtered.
Also envisioned as part of the present invention is a process for spinning polymers. Preferably, the process is for melt spinning molten thermoplastic polymers. An apparatus of the present invention is useful in the process of the present invention. In the process, one or more molten polymer streams, preferably at least two, enter a spin pack. In the spin pack, the polymers are distributed as discrete streams from the inlet to the backhole of a spinneret where they may or may not meet, depending on the particular cross-section being extruded. Distribution is accomplished by routing the polymer through holes and into channels where the channels are bounded by at least the plate immediately above or below. Alternatively, the channels are bounded by both the plates above and below.
In the channels, the polymer flows transversely (or perpendicular) to the flow in the holes. Eventually, the polymer exits the channel through another hole in the plate immediately below.
The apparatus and process of the present invention are useful for melt spinning thermoplastic polymers according to known or to be developed conditions, e.g., temperature, denier, speed, etc., for any melt spinnable polymer. Post extrusion treatment of the fibers may also be according to standard procedures. The resulting fibers are suitable for use as expected for fibers of the type.
The invention will be described by reference to the following detailed example. The example is set forth by way of illustration, and is not intended to limit the scope of the invention.
EXAMPLE 1
EDM Plates
The x-y coordinates of 24 circular holes and 6 oblong holes are programmed into a numerically controlled EDM machine supplied by Schiess Nassovir with a 0.096 micron spark width correction (offset).
A 0.5 mm thick stainless steel plate is sandwiched between two 2 mm thick support plates and fastened into the frame opening of the EDM machine with help of three clamps. A 0.5 mm diameter hole is drilled into the center of each hole and channel to be eroded and a 0.15 mm brass wire electrode is threaded through the hole. The wire is properly tensioned. The cutting voltage is 70 volts. The table with the plate assembly is guided by means of the computerized x-y guidance program to achieve the desired pattern after the power has been turned on. While cutting, the brass wire electrode is forwarded at a rate of 8 mm/sec and the plate assembly advances at a cutting rate of 3.7 mm/min. Throughout the cutting, the brass wire electrode is flushed with demineralized water with a conductivity of 2×10 E4 Ohm cm with a nozzle pressure of 0.5 kg/cm 2 . After the desired pattern has been cut, the support plates are discarded.
EXAMPLE 2
Spinning Fibers
Thin distribution plates having cuts similar to the plates shown in FIGS. 4, 5 and 6 are machined from 26 gauge (0.018") 430 stainless steel. The plates are inserted between a reusable spinneret and a metering plate. A top plate having polymer inlets is located upstream of the metering plate. The top plate, metering plate, thin distribution plates and spinneret are cylindrical in shape. These plates are positioned into a spinneret housing with through bolts which provide a clamping force to seal the surfaces of the plates.
The sheath polymer is nylon 6 having an RV of approximately 2.4. The temperature of the molten sheath polymer is controlled at 278° C. The core polymer is nylon 6 having an RV of approximately 2.7. The temperature of the molten core polymer is controlled at 288° C. The spin pack and spinneret are controlled at 285° C. Each spinneret has two groups of three capillaries having a diameter of 200 microns and a length of 400 microns.
The fibers are quenched as they exit the spinneret by a stream of cross flowing air having a velocity of approximately 30 m/min. The yarns make an "S" shaped path across a pair of godets before being wound onto a bobbin. The surface velocities of the first and second godets is 1050 and 1054 m/min respectively. The yarn has a velocity of 1058 m/min at the winder. A water-based finish dispersion is applied to the yarns prior to winding.
Three filament 50 denier yarn is spun from the plate assembly. Each filament is a round, concentric, sheath/core bicomponent having a core which makes up 10% of the total fiber cross-sectional area. The resulting sheath/core yarns have good physical properties as demonstrated from the following table.
TABLE______________________________________ Breaking Tenac- Elongation ModulusDen- Load ity (g/ at 1% at 10% Modulusier (g) den) (%) (g/den) (g/den)______________________________________Avg. 49.6 58.67 1.18 413.89 3.41 2.63Std. 0.02 2.27 0.05 15.65 2.78 0.11Dev.______________________________________
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A spin pack for spinning synthetic fibers from two or more liquid polymer streams includes a supply for at least two polymer streams to the spin pack; a spinneret having extrusion orifices; and flow distribution plate sets. The flow distribution plate sets include at least one patterned plate having edges which define a substantially regular two-dimensional geometric shape, a substantially planar upstream surface, a substantially planar downstream surface and at least one flow distribution pattern stenciled therein by cutting through. For each patterned plate, at least one boundary plate stacked sealingly adjacent thereto and having edges which define a substantially regular geometric shape, a substantially planar upstream surface and a substantially planar downstream surface. The boundary plate has cut-through holes connecting the upstream surface with the downstream surface to form at least one flow-through channel to allow fluid flow through the patterned plate but otherwise is substantially solid.
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CROSS-REFERENCE TO RELATED APPLICATION
The instant patent application is related to U.S. Provisional Patent Application Ser. No. 61/080,370, filed on Jul. 14, 2008, titled “Positive Handle Stop For Switches,” the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to handle stops. More particularly, the invention encompasses a positive handle stop for a switch. The positive handle stop for a switch, such as, a safety switch, prevents the handle of a switch from returning to the shipping position once the switch is turned ON. The invention also includes a shipping position for the inventive handle so as to reduce the size of the packaging need to ship the switch apparatus.
BACKGROUND INFORMATION
A positive handle stop provides a mechanical stop for a handle to engage in when going from an ON-position to an OFF-position.
For most all applications handles for safety switches are designed to prevent the switch operator's hands from being injured when operating the safety switch. In order to prevent injury the handle must protrude past the enclosure cover in the ON-position and also in the OFF-positions. Since the handle protrudes past the cover the shipping carton must be enlarged to accommodate the handle protrusion and which in turn increases the carton, packaging and shipping costs.
Currently the handle guard, such as, one provide by Siemens Corporation, is located on the outside of the handle and provides a positive stop for the ON, OFF, and the shipping position of the safety switch. The stop for the OFF-position is a metal protrusion formed in the handle guard. In order to place the switch in the shipping position the handle must be forced to the side of the handle guard protrusion slightly deforming the handle. Once the handle is moved past the stop to the ON-position it returns to its' original form. Other manufacturers in the industry either do not provide a shipping position for their safety switches or a positive-type stop for their handles for their safety switches.
Another problem with having the handle guard protrusion as the positive stop is that after repeated use the handle will wear the stop down allowing the handle to move past the OFF-position. The switch has a provision for locking in the OFF-position by placing a lock through an opening in the handle and handle guard. If the handle is moved past the OFF-position it may be possible to place a lock in the handle guard only and not the handle allowing an operator to turn the switch ON with the lock installed.
Thus, a need exists for an improved positive handle stop for safety switches.
This invention overcomes the problems of the prior art and provides an inventive positive handle stop for switches.
PURPOSES AND SUMMARY OF THE INVENTION
The invention is a novel positive handle stop for switches.
Therefore, one purpose of this invention is to provide a novel positive handle stop for switches.
Another purpose of this invention is to provide a positive handle stop for a switch which prevents a handle of the switch from returning to the shipping position once the switch is turned ON.
Yet another purpose of this invention is to provide a positive handle stop for a switch which has a shipping position and an operational position.
Still yet another purpose of this invention is to provide a positive handle stop for a switch which has a shipping position to reduce the size of the shipping package.
Therefore, one aspect this invention comprises a handle stop for a switching apparatus, comprising:
(a) at least one handle guard, wherein a first end of said handle guard and a second end of said handle guard are secured to a switching apparatus, and wherein said handle guard has an open area between said first end and said second end;
(b) at least one handle stop, wherein said handle stop is inside said open area of said handle guard, and wherein said handle stop has a first end and a second end, and wherein said first end of said handle stop is secured to an inner portion of said handle guard and said second end of said handle stop has at least one securing means which rests against an inner face of said handle guard in a first position and protrudes through a first opening in said handle guard in a second position; and
(c) a handle, wherein said handle is inside said open area of said handle guard, and wherein said handle has a first end and a second end, and wherein said first end of said handle is secured to said switching apparatus and said second end slides against said handle stop in a first position, and rests against said handle stop in a second position, thereby forming said handle stop for a switching apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention that are novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The drawings are for illustration purposes only and are not drawn to scale. Furthermore, like numbers represent like features in the drawings. The invention itself, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:
FIG. 1 is an outside perspective view of an exemplary switch apparatus having a positive handle stop for a safety switch which is used to illustrate an embodiment of the present invention.
FIG. 2 is an enlarged inside view showing the handle along with the inventive handle stop and the handle guard.
FIG. 3 is an outside view of the inventive positive handle stop with the cover and the enclosure showing the inventive handle in a shipping position.
FIG. 4 is an outside view of the inventive positive handle stop with the cover and the enclosure showing the inventive handle in an OFF-position.
FIG. 5 is an enlarged perspective view of the inventive positive handle stop while viewing from an OFF-position of the inventive handle.
FIG. 6 is an enlarged perspective view of the inventive positive handle stop while viewing from an ON-position of the inventive handle.
DETAILED DESCRIPTION
The positive handle stop of the present invention provides a novel mechanical stop for the handle to engage when going from the ON to the OFF position or to the shipping position.
As stated earlier, the positive handle stop eliminates the problems of the prior art. The positive handle stop is typically displaced or positioned using a screwdriver or a pair of pliers, which allows the handle to move or be moved into the shipping position. Once the handle is moved to the OFF-position or an ON-position the positive handle stop springs back into place. The positive handle stop incorporates a hook feature that can be locked into the handle guard. When the handle is moved to the OFF-position it will cause the hook feature to lock into the handle guard locking the positive handle stop in place.
Referring to FIGS. 1 through 6 , taken together, FIG. 1 is an outside perspective view of an exemplary switch apparatus 23 , having a positive handle stop 20 , such as, for a safety switch 23 , which is used to illustrate an embodiment of the present invention. While, FIG. 2 is an enlarged inside view showing the handle 10 , along with the inventive handle stop 20 , and the handle guard 30 . The switch apparatus 23 , has at least one handle 10 , having an upper portion 12 , a bent portion 14 and a bottom portion 16 . The upper portion 12 , has at least one hole or opening 13 . The bottom portion 16 , has at least one hole or opening 17 . The switch apparatus 23 , has at least one handle stop 20 , where the handle stop 20 , has a first portion 22 , a second portion 24 , and a third portion 26 . The first portion 22 , has at least one tab or protrusion 21 , and the third portion 26 , has at least one securing location 27 . The switch apparatus 23 , has at least one handle guard 30 , to couple with and to protect the handle 10 , and the handle stop 20 . The handle guard 30 , has a face or a first portion 32 , a first bent portion 34 , a first securing portion 36 , a second bent portion 35 , and a second securing portion 38 . The first bent portion 34 , has at least one securing location 37 , and the first securing portion 36 , has at least one opening or securing location 39 . The second securing portion 38 , has at least one opening or securing location 47 . The face or first portion 32 , has at least one first opening or securing location 31 , and at least one second opening or securing location 33 , and optionally at least one third opening or securing location 43 . The securing means 21 , of the handle stop 20 , is preferably inserted through the opening 31 , and secures the handle stop 20 , to the handle guard 30 . The handle stop 20 , is also secured to the handle guard 30 , using the securing location 27 , and the securing location 37 .
The securing means 21 , of the inventive handle stop 20 , preferably has a flexible bent portion 29 , such as a hairpin type bent portion 29 , or so that when the securing means 21 , is inserted inside the hole or opening 31 , the flexible bent portion 29 , can pass through the opening 31 , and an end portion of the flexible bent portion 29 , can lodge itself against an outer face or surface 72 , of the handle guard 30 . For some applications the bent portion 29 , could be a separate piece that is secured to the end of the securing means 21 , so as to form a T-junction or a L-junction. It is preferred that during operation of the apparatus 23 , the bent portion 29 , which is preferably arcuate or arched so that an end portion of the bent portion 29 , rests against the outer surface 72 , of the handle guard 30 , like an end of a bow. It should be appreciated that during shipping of the apparatus 23 , the securing means 21 , along with the flexible bent portion 29 , are pushed back through the hole or opening 31 , by means of a screw-driver or a pair of pliers and the flexible bent portion 29 , rest against the opening 31 , but on an inside face or surface, of the handle 12 . It should be appreciated that the end of the securing means 21 , of the positive handle stop 20 , rests against the handle 10 , in the shipping position, such that a portion of the handle 10 , is inside a portion of an opening or slot 74 , in the handle guard 30 .
FIG. 3 is an outside view of the inventive positive handle stop 20 , with the cover 50 , and the enclosure 60 , showing the inventive handle 10 , in a shipping position. The handle 10 , can also have a sleeve or a handle cover 15 . At least one securing means 67 , such as, a bolt 67 , or a screw 67 , secure the handle 10 , to the enclosure 60 , at hole or opening 17 . It is preferred that when the apparatus 23 , is prepared for shipping, the handle 10 , is moved to a position which is below a plane of an enclosure cover 50 , of the switching apparatus 23 . However, for some applications it may be preferred to have a substantial portion of the handle 10 , below a plane of the enclosure cover 50 , during the shipping process of the switching apparatus 23 .
FIG. 4 is an outside view of the inventive positive handle stop 20 , with the cover 50 , and the enclosure 60 , showing the inventive handle 10 , in an OFF-position. At least two securing means 49 , such as, a bolt 49 , or a screw 49 , secures the handle guard 30 , to the enclosure 60 , at the openings or securing locations 39 and 47 .
FIG. 5 is an enlarged perspective view of the inventive positive handle stop 20 , while viewing from an OFF-position of the inventive handle 10 . As one can see that in the OFF-position the hole or opening 13 , in the handle 10 , is aligned with the hole or opening 33 , in the handle guard 30 , such that a lock (not shown) can be used to prevent or limit or stop the movement of the handle 10 , relative to the handle guard 30 , that is fixedly secured to the enclosure 60 . One can also see that the bottom of the upper portion 12 , of the handle 10 , is in contact with, or rests on, the first portion 22 , of the handle stop 20 , and the positive handle stop 20 , prevents the movement or sliding of the handle 10 , towards the securing location 27 , 37 , as more clearly seen when FIG. 2 and FIG. 5 , are viewed together.
FIG. 6 is an enlarged perspective view of the inventive positive handle stop 20 , while viewing from an ON-position of the inventive handle 10 . As one can see that in the operational or ON-position of the apparatus 23 , the flexible bent portion 29 , of the securing means 21 , has been popped through the opening 31 , and the end of the flexible bent portion 29 , rests on the outer face surface 72 , of the handle guard 30 . Additionally, in the ON-position the handle 10 , is moved away from the first portion 22 , of the handle stop 20 , and is positioned closer to the second bent portion 35 , of the handle guard 30 , as more clearly seen when FIG. 2 and FIG. 6 , are viewed together.
The sleeve or a handle cover 15 , is preferably made of an electrically insulating material, wherein the electrically insulating material is selected from a group comprising, Teflon, nylon, plastic, composite material, and combination thereof, to name a few.
The hole or opening 31 , in the handle guard 30 , to accommodate the securing means 21 , is preferably selected from a group comprising, trapezoidal hole, square hole, rectangular hole, elliptical hole, triangular hole, and combination thereof, to name a few.
The securing means 21 , along with the flexible bent portion 29 , is preferably made from material selected from a group comprising, stainless steel, steel, metallic material, plastic, rubber, composite, and combination thereof, to name a few.
In order to eliminate the extra packaging cost the inventive handle 10 , of this invention is placed in a shipping position. In the shipping position the inventive handle 10 , of this invention is moved past the OFF-position allowing the inventive handle 10 , to drop below the plane of the enclosure cover 50 , or at least be substantially in the same plane as the plane of the enclosure cover 50 .
The safety switch 23 , preferably also has a provision for locking in the OFF-position, which can be done by placing a lock (not shown) through openings 13 and 33 , in the handle 10 , and handle guard 30 , respectively. If the handle 10 , if moved past the OFF-position it may be possible to place a lock (not shown) in the handle guard 30 , only and not on the handle 10 , thus allowing an operator to turn the switch ON with the lock (not shown) still installed in the opening 33 , of the handle guard 30 .
While the present invention has been particularly described in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.
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The present invention relates generally to handle stops. More particularly, the invention encompasses a positive handle stop for a switch. The positive handle stop for a switch, such as, a safety switch, prevents the handle of a switch from returning to the shipping position once the switch is turned ON. The invention also includes a shipping position for the inventive handle so as to reduce the size of the packaging need to ship the switch apparatus.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/642,993, filed Dec. 19, 2006, now abandoned, which claims the benefit of U.S. Prov. Pat. App. Ser. No. 60/751,680, filed on Dec. 19, 2005, now expired, the entire disclosures of which are incorporated by reference herein in their entirety.
[0002] This application is also a continuation in part of U.S. patent application Ser. No. 11/395,448 entitled “Artificial human limbs and joints employing actuators, springs, and Variable-Damper Elements” filed on Mar. 31, 2006 by Hugh M. Herr, Daniel Joseph Paluska, and Peter Dilworth. Application Ser. No. 11/395,448 claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/666,876 filed on Mar. 31, 2005 and the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/704,517 filed on Aug. 1, 2005.
[0003] This application is also a continuation in part of U.S. patent application Ser. No. 11/499,853 entitled “Biomimetic motion and balance controllers for use in prosthetics, orthotics and robotics” filed on Aug. 4, 2006 by Hugh M. Herr, Andreas G. Hofmann, and Marko B. Popovic. Application Ser. No. 11/499,853 claims the benefit of the filing date of, U.S. Provisional Patent Application Ser. No. 60/705,651 filed on Aug. 4, 2005.
[0004] This application is also a continuation in part of U.S. patent application Ser. No. 11/495,140 entitled “An Artificial Ankle-Foot System with Spring, Variable-Damping, and Series-Elastic Actuator Components” filed on Jul. 29, 2006 by Hugh M. Herr, Samuel K. Au, Peter Dilworth, and Daniel Joseph Paluska. Application Ser. No. 11/495,140 claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/704,517 filed on Aug. 1, 2005 and was also a continuation in part of the above-noted application Ser. No. 11/395,448.
[0005] This application is also a continuation in part of U.S. patent application Ser. No. 11/600,291 entitled “Exoskeletons for running and walking” filed on Nov. 15, 2006 by Hugh M. Herr, Conor Walsh, Daniel Joseph Paluska, Andrew Valiente, Kenneth Pasch, and William Grand. Application Ser. No. 11/600,291 claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/736,929 filed on Nov. 15, 2005 and is a continuation in part of the above noted applications Ser. Nos. 11/395,448, 11/499,853 and 11/495,140.
[0006] The present application claims the benefit of the filing date of each of the foregoing patent applications and incorporates the disclosure of each of the foregoing applications herein by reference.
FIELD OF THE TECHNOLOGY
[0007] This invention relates to artificial joints and limbs for use in prosthetic, orthotic or robotic devices.
BACKGROUND
[0008] Biomimetic Hybrid Actuators employed in biologically-inspired musculoskeletal architectures as described in the above noted U.S. patent application Ser. No. 11/395,448 employ an electric motor for supplying positive energy to and storing negative energy from an artificial joint or limb, as well as elastic elements such as springs, and controllable variable damper components, for passively storing and releasing energy and providing adaptive stiffness to accommodate level ground walking as well as movement on stairs and surfaces having different slopes.
[0009] The above noted application Ser. No. 11/495,140 describes an artificial foot and ankle joint consisting of a curved leaf spring foot member that defines a heel extremity and a toe extremity, and a flexible elastic ankle member that connects said foot member for rotation at the ankle joint. An actuator motor applies torque to the ankle joint to orient the foot when it is not in contact with the support surface and to store energy in a catapult spring that is released along with the energy stored in the leaf spring to propel the wearer forward. A ribbon clutch prevents the foot member from rotating in one direction beyond a predetermined limit position, and a controllable damper is employed to lock the ankle joint or to absorb mechanical energy as needed. The controller and a sensing mechanisms control both the actuator motor and the controllable damper at different times during the walking cycle for level walking, stair ascent and stair descent.
[0010] The above noted Application G-25 describes an exoskeleton worn by a human user consisting of a rigid pelvic harness worn about the waist of the user and exoskeleton leg structures each of which extends downwardly alongside one of the human user's legs. The leg structures include hip, knee and ankle joints connected by adjustable length thigh and shin members. The hip joint that attaches the thigh structure to the pelvic harness includes a passive spring or an active actuator to assist in lifting the exoskeleton and said human user with respect to the ground surface upon which the user is walking and to propel the exoskeleton and human user forward. A controllable damper operatively arresting the movement of the knee joint at controllable times during the walking cycle, and spring located at the ankle and foot member stores and releases energy during walking.
[0011] The additional references listed below identify materials which are referred to in the description that follows. When cited, each reference is identified by a single number in brackets; for example, the first reference below is cited using the notation “{1}.”
1. Palmer, Michael. Sagittal Plane Characterization of Normal Human Ankle Function across a Range of Walking Gait Speeds. Massachusetts Institute of Technology Master's Thesis, 2002. 2. Gates Deanna H., Characterizing ankle function during stair ascent, descent, and level walking for ankle prosthesis and orthosis design. Master thesis, Boston University, 2004. 3. Hansen, A., Childress, D. Miff, S. Gard, S. and Mesplay, K., The human ankle during walking: implication for the design of biomimetic ankle prosthesis, Journal of Biomechanics, 2004 (In Press). 4. Koganezawa, K. and Kato, I., Control aspects of artificial leg, IFAC Control Aspects of Biomedical Engineering, 1987, pp. 71-85. 5. Herr H, Wilkenfeld A. User-Adaptive Control of a Magnetorheological Prosthetic Knee. Industrial Robot: An International Journal 2003; 30: 42-55. 6. Seymour Ron, Prosthetics and Orthotics: Lower limb and Spinal, Lippincott Williams & Wilkins, 2002. 7. G. A. Pratt and M. M. Williamson, “Series Elastic Actuators,” presented at 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems, Pittsburgh, Pa., 1995. 8. Inman V T, Ralston H J, Todd F. Human walking Baltimore: Williams and Wilkins; 1981. 9. Hof. A. L. Geelen B. A., and Berg, J. W. Van den, “Calf muscle moment, work and efficiency in level walking; role of series elasticity,” Journal of Biomechanics, Vol 16, No. 7, pp. 523-537, 1983. 10. Gregoire, L., and et al, Role of mono- and bi-articular muscles in explosive movements, International Journal of Sports Medicine 5, 614-630. 11. Endo, K., Paluska D., Herr, H. A quasi-passive model of human leg function in level-ground walking IEEE/RSJ International Conference on Intelligent Robots and Systems ( IROS ); Oct. 9-16, 2006; Beijing, China.
[0023] As noted in references {1}, {2}, {3}, and {4} above, an artificial limb system that mimics a biological limb ideally needs to fulfill a diverse set of requirements. The artificial system must be a reasonable weight and have a natural morphological shape, but still have an operational time between refueling or battery recharges of at least one full day. The system must also be capable of varying its position, stiffness, damping and nonconservative motive power in a comparable manner to that of a normal, healthy biological limb. Still further, the system must be adaptive, changing its characteristics given such environmental disturbances as walking speed and terrain variation. The current invention describes a novel actuator and limb architecture capable of achieving these many requirements.
[0024] From recent biomechanical studies described in references {1}, {2} and {3} above, researchers have determined that biological joints have a number of features. Among these are:
(a) the ability to vary stiffness and damping; (b) the ability to generate large amounts of positive mechanical work (nonconservative motive output); and (c) the ability to produce large amounts of power and torque when needed.
[0028] An example of the use of more than one control strategy in a single biological joint is the ankle. See {1} and {2}. For level ground ambulation, the ankle behaves as a variable stiffness device during the early to midstance period, storing and releasing impact energies. Throughout terminal stance, the ankle acts as a torque source to power the body forward. In distinction, the ankle varies damping rather than stiffness during the early stance period of stair descent. These biomechanical findings suggest that in order to mimic the actual behavior of a human joint or joints, stiffness, damping, and nonconservative motive power must be actively controlled in the context of an efficient, high cycle-life, quiet and cosmetic biomimetic limb system, be it for a prosthetic or orthotic device. This is also the case for a biomimetic robot limb since it will need to satisfy the same mechanical and physical laws as its biological counterpart, and will benefit from the same techniques for power and weight savings.
[0029] The current state of the art in prosthetic leg systems include a knee joint that can vary its damping via magnetorheological fluid as described in {5}, and a carbon fiber ankle which has no active control, but that can store energy in a spring structure for return at a later point in the gait cycle e.g. the Flex-Foot {4} or the Seattle-Lite {6}. None of these systems are able to add energy during the stride to help keep the body moving forward or to reduce impact losses at heel strike. In the case of legged robotic systems, the use of the Series Elastic Actuator (SEA) enables robotic joints to control their position and torque, such that energy may be added to the system as needed. See {7}. In addition, the SEA can emulate a physical spring or damper by applying torques based on the position or velocity of the joint. However, for most applications, the SEA requires a tremendous amount of electric power for its operation, resulting in a limited operational life or an overly large power supply. Robotic joint designs in general use purely active components and often do not conserve electrical power through the use of variable-stiffness and variable-damping devices.
SUMMARY
[0030] The following summary provides a simplified introduction to some aspects of the invention as a prelude to the more detailed description that is presented later, but is not intended to define or delineate the scope of the invention.
[0031] In this specification and the claims, the following terms have the following meanings:
actuator: see the definition of “motor” below; agonist: A contracting element that is resisted or counteracted by another element, the antagonist; agonist-antagonist actuator: a mechanism comprising (at least) two actuators that operate in opposition to one another: an agonist actuator that, when energized, draws two elements together and an antagonist actuator that, when energized, urges the two elements apart; antagonist: An expanding element that is resisted or counteracted by another element, the agonist; biomimetic: a man-made structure or mechanism that mimics the properties and behavior of biological structures or mechanisms, such as joints or limbs; dorsiflexion: bending the ankle joint so that the end of the foot moves upward; elastic: capable of resuming an original shape after deformation by stretching or compression; extension: A bending movement around a joint in a limb that increases the angle between the bones of the limb at the joint; flexion: A bending movement around a joint in a limb that decreases the angle between the bones of the limb at the joint; motor: an active element that produces or imparts motion by converting supplied energy into mechanical energy, including electric, pneumatic or hydraulic motors and actuators; plantarflexion: bending the ankle joint so that the end of the foot moves downward; spring: an elastic device, such as a metal coil or leaf structure, which regains its original shape after being compressed or extended.
[0044] For an artificial joint to behave like a biological joint, a synthetic actuator must have the following properties:
[0045] 1) The actuator must consume negligible power when exerting zero force. Near the equilibrium length of muscle (peak of active tension-length curve), the passive tension is typically zero. Thus a muscle-actuated joint goes limp when the muscles are not electrically stimulated.
[0046] 2) The actuator must consume negligible power when outputting force at constant length (isometric) and while performing dissipative, nonconservative work. Muscle tissue is very efficient for isometric and dissipative control modes.
[0047] 3) The actuator must be capable of independently engaging flexion and extension tendon-like, series springs. Since biological joints have at least one flexor muscle and at least one extensor muscle, the time at which a flexor tendon becomes taught or engaged can be independent of the time at which an extensor tendon becomes engaged. As an example, with a muscle-actuated joint, the elastic energy from one tendon can be released as a second tendon is being elongated.
[0048] 4) The actuator must be capable of independently varying joint position and stiffness. Through co-contraction between a muscle flexor and extensor, joint stiffness can be modulated without changing joint position. Further, joint position can be varied while keeping joint stiffness constant.
[0049] 5) The actuator must be capable of exploiting series elasticity for mechanical power amplification, or a “catapult” control modality. For motion tasks that require high mechanical power, muscle-tendon units in animals and humans often employ a catapult control where the muscle belly stretches the series tendon, and later that stored elastic energy is released to achieve relatively higher joint powers than would be possible if the muscle belly were to generate that power directly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] In the detailed description which follows, frequent reference will be made to the attached drawings, in which:
[0051] FIG. 1 depicts the various subdivisions of the stance phase of walking;
[0052] FIGS. 2A , 2 B and 2 C show torque vs. angle plots in level-ground walking for slow speed, normal and fast walking;
[0053] FIG. 3 illustrates human ankle biomechanics for stair ascent;
[0054] FIG. 4 illustrates human ankle-foot biomechanics for stair descent;
[0055] FIGS. 5A and 5B illustrate the manner in which knee angle and knee power respectively vary during the walking cycle for level ground walking;
[0056] FIGS. 6A and 6B are posterior and side elevational views respectively of an agonist-antagonist actuator embodying the invention;
[0057] FIGS. 7A and 7B are posterior and side elevational views of an agonist-antagonist actuator mechanism implementing an artificial ankle;
[0058] FIGS. 8A and 8B are posterior and side elevational views of agonist-antagonist actuator mechanisms implementing an artificial knee;
[0059] FIGS. 9A and 9B are side elevational and perspective views of an agonist-antagonist actuator mechanism positioned on both sides of the joint axis;
[0060] FIG. 10A and 10B are posterior and side elevational views of an agonist-antagonist actuator mechanism using motor and spring combinations;
[0061] FIG. 11A shows a model of leg prosthesis employing series-elastic clutches at the hip, knee and ankle joints;
[0062] FIGS. 11B and 11C are graphs comparing the behaviors of biological ankle and knee joints respectively with the modeled joints of FIG. 11A ;
[0063] FIG. 12A , 12 B and 12 C are plots of the mechanical power of each model element is versus percentage gait cycle for ankle, knee and hip, respectively;
[0064] FIG. 13A shows the major components of the transtibial system are shown;
[0065] FIG. 13B shows the monoarticular ankle mechanism of FIG. 13A in more detail;
[0066] FIG. 13C and 13D show elevational and schematic views respectively of the bi-articular ankle knee mechanism of FIG. 13A ;
[0067] FIGS. 14A and 14B shows the major components of an artificial ankle and knee system;
[0068] FIG. 14C is a schematic diagram of the artificial ankle and knee system seen in FIGS. 14A and 14B ; and
[0069] FIG. 14D shows the knee's variable moment arm (VMA) device (seen at the top of FIGS. 14A and 14B ) in more detail.
DETAILED DESCRIPTION
[0070] In the construction of a biologically realistic limb system that is high performance, light weight, quiet and power efficient, a agonist-antagonist actuator design is proposed herein comprising a plurality of actuators and series elastic structures. Since it is desirable to minimize the overall weight of the limb design, the efficiency of the agonist-antagonist actuator design is critical, especially given the poor energy density of current power supplies, e.g. lithium-ion battery technology. By understanding human biomechanics, the lightest, most energy efficient agonist-antagonist actuator design can be achieved.
[0071] In the next section, the key features of biomechanical systems are highlighted. A more complete description of biomechanical systems is found in the patent applications cited in the foregoing “Cross Reference to Related Applications” whose disclosures are incorporated herein by reference.
[0072] Joint Biomechanics: The Human Ankle
[0073] Understanding normal walking biomechanics provides the basis for the design and development of the agonist-antagonist actuator design. Specifically, the function of human ankle under sagittal plane rotation is described for different locomotor conditions including level-ground walking and stair/slope ascent and descent. In addition, the function of the human knee during level ground walking is described. From these biomechanical descriptions, the justifications for key mechanical components and configurations of the actuator invention are established.
[0074] Level-Ground Walking
[0075] A level-ground walking gait cycle is typically defined as beginning with the heel strike of one foot seen at 103 in FIG. 1 and ending at the next heel strike of the same foot seen at 113 . See {8}. The main subdivisions of the gait cycle are the stance phase (˜60%) and the swing phase (˜40%) which are illustrated in FIG. 1 . The swing phase represents the portion of the gait cycle when the foot is off the ground. The stance phase begins at heel strike when the heel touches the floor and ends at toe off when the same foot rises from the ground surface. Additionally, we can further divide the stance phase into three sub-phases: Controlled Plantar Flexion (CP), Controlled Dorsiflexion (CD), and Powered Plantar Flexion (PP).
[0076] Detailed descriptions for each phase and the corresponding ankle functions are described in FIG. 1 . CP begins at heel-strike 103 and ends at foot-flat shown at 105 . Simply speaking, CP describes the process by which the heel and forefoot initially make contact with the ground. In {1} and {3}, researchers showed that CP ankle joint behavior is consistent with a linear spring being loaded or stretched where joint torque is proportional to joint position.
[0077] During the loading process, the spring behavior is, however, variable; joint stiffness is continuously modulated by the body from step to step. After the CP period, the CD phase begins. In FIG. 2 , the average torque versus angle curves are shown for 68 healthy, young participants walking on a level surface. As is shown, during CP (from 103 to 105 ), the ankle behaves as a linear spring of variable stiffness during the loading cycle, but the torque curve does not trace back to point 1 , but rather assumes higher torque values during the early period of CD.
[0078] Ankle torque versus position during the CD period from 105 to 107 can often be described as a nonlinear spring being loaded or stretched where stiffness increases with increasing ankle position. It is noted that as walking speed increases, the extent to which the ankle behaves as a nonlinear spring increases, with the CD loading phase exhibiting distinct nonlinear behavior during fast walking (see fast walking, FIG. 2 ). The main function of the ankle during CD is to store elastic energy to propel the body upwards and forwards during the PP phase. See {9} and {3}.
[0079] The PP phase begins at 107 after CD and ends at the instant of toe-off shown at 109 . During PP in moderate to fast walking speeds, the ankle can be modeled as a catapult in series or in parallel with the CD spring or springs. Here the catapult component includes an actuator that does work on a series spring during the CD phase and/or during the first half of the PP phase. The catapult energy is then released along with the spring energy stored during the CD phase to achieve the high plantar flexion power during late stance. This catapult behavior is necessary because the work generated during PP is more than the negative work absorbed during the CP and CD phases for moderate to fast walking speeds as clearly seen in FIGS. 2A-2C . See {1}, {2}, {3} and {9}.
[0080] FIGS. 2A , 2 B and 2 C show torque vs. angle plots in level-ground walking for slow speed walking at 0.9 m/sec ( FIG. 2A ), normal walking speed at 1.25 m/sec ( FIG. 2B ) and fast walking at 1.79 m/sec. Only the stance period of a single foot is shown (heel strike to toe off). Point 1 on the charts denotes heel strike, point 2 foot flat, point 3 peak dorsiflexion, and point 4 toe off. Although during slow walking the loading curve (points 2 - 3 ) is approximately equal to the unloading curve (points 3 - 4 ), for higher walking speeds the torque assumes higher values during the unloading, PP phase (points 3 - 4 ). Hence, for walking speeds greater than 0.9 m/s (slow speed), the human ankle cannot be modeled as a series of coupled springs because the positive work performed by the ankle exceeds the negative work. It is noted that, as walking speed increases, the degree of nonlinear behavior during CD (points 2 - 3 ) increases along with the total amount of positive work production during PP (points 3 - 4 ), consistent with a catapult model where the soleus muscle belly slowly elongates the series Achilles tendon spring during CD, increasing the slope of the torque versus angle curve and the subsequent positive power output of the ankle.
[0081] Stair Ascent and Descent
[0082] FIG. 3 illustrates human ankle biomechanics for stair ascent; The first phase of stair ascent is called Controlled Dorsiflexion 1 (CD 1 ), which begins with foot strike in a dorsiflexed position at 201 and continues to dorsiflex until the heel contacts the step surface at 203 . In this phase, the ankle can be modeled as a linear spring. The second phase is Powered Plantar flexion 1 (PP 1 ), which begins at the instant of foot flat (when the ankle reaches its maximum dorsiflexion) at 203 and ends when dorsiflexion begins once again at 205 . The human ankle behaves as a torque actuator to provide extra energy to support the body weight. The third phase is Controlled Dorsiflexion 2 (CD 2 ), in which the ankle dorsiflexes as seen at 205 until heel-off at 207 . For that phase, the ankle can be modeled as a linear spring. The fourth and final phase is Powered Plantar flexion 2 (PP 2 ). Here the foot pushes off the step as seen at 207 , acting as a torque actuator in parallel with the CD 2 spring to propel the body upwards and forwards until toe-off occurs at 209 and the swing phase begins.
[0083] FIG. 4 illustrates the human ankle-foot biomechanics for stair descent. The stance phase of stair descent is divided into three sub-phases: Controlled Dorsiflexion 1 (CD 1 ), Controlled Dorsiflexion 2 (CD 2 ), and Powered Plantar flexion (PP). CD 1 begins at forefoot strike seen at 303 and ends at foot-flat seen at 305 . In this phase, the human ankle can be modeled as a variable damper. In CD 2 , from foot flat at 305 , the ankle continues to dorsiflex forward until it reaches a maximum dorsiflexion posture at 307 . Here the ankle acts as a linear spring in series with a variable-damper designed to effectively control the amount of energy stored by the linear spring. During PP, beginning at 307 , the ankle plantar flexes until the foot lifts from the step at 309 . In this final phase, the ankle releases stored CD 2 energy, propelling the body upwards and forwards. From toe off at 309 until the next foot strike at 313 , the foot in the swing phase.
[0084] Because the kinematic and kinetic patterns at the ankle during stair ascent/descent are significantly different from that of level-ground walking (see {2}), a description of such ankle-foot biomechanics seems appropriate. For stair ascent, the human ankle-foot can be effectively modeled using a combination of an actuator and a variable stiffness mechanism. However, for stair descent, variable damping needs also to be included for modeling the ankle-foot complex; the power absorbed by the human ankle is much greater during stair descent than the power released by 2.3 to 11.2 J/kg. See reference {2}.
[0085] Joint Biomechanics: The Human Knee
[0086] There are five distinct phases to knee operation throughout a level-ground walking cycle as illustrated in FIGS. 5A and 5B . See reference {8}. FIG. 5A shows how the knee angle varies during the walking cycle, and FIG. 5B shows how knee power varies. As seen in FIG. 5A , the stance phase of walking can be divided into three sub-phases: Stance Flexion, Stance Extension, and Pre-Swing. The swing phase is divided into two phases: Swing Flexion and Swing Extension. As seen in FIG. 5B , for level ground walking, the human knee does more negative work than positive work.
[0087] Beginning at heel strike indicated at 403 , the stance knee begins to flex slightly. This flexion period, called the Stance Flexion phase, allows for shock absorption upon impact as well as to keep the body's center of mass at a more constant vertical level throughout the stance period. During this phase, the knee acts as a spring, storing energy in preparation for the Stance Extension phase.
[0088] After maximum flexion is reached in the stance knee at 404 , the joint begins to extend, until maximum extension is reached as indicated at 406 . This knee extension period is called the Stance Extension phase. Throughout the first ˜60% of Stance Extension, the knee acts as a spring, releasing the stored energy from the Stance Flexion phase of gait. This first release of energy corresponds to power output indicated at 501 in the graph at the bottom of FIG. 5B . During the last ˜30% of Stance Extension, the knee absorbs energy in a second spring and then that energy is released during the next gait phase, or Pre-Swing.
[0089] During late stance or Pre-Swing from 406 to 407 , the knee of the supporting leg begins its rapid flexion period in preparation for the swing phase. During early Pre-Swing, as the knee begins to flex in preparation for toe-off, the stored elastic energy from Stance Extension is released. This second release of energy corresponds to power output seen at 503 in FIG. 5B .
[0090] As the hip is flexed, and the knee has reached a certain angle in Pre-Swing, the leg leaves the ground at 407 and the knee continues to flex. At toe-off 407 , the Swing Flexion phase of gait begins. Throughout this period, knee power is generally negative where the knee's torque impedes knee rotational velocity. During terminal Swing Flexion, the knee can be modeled as an extension spring in series with a variable damper, storing a small amount of energy in preparation for early Swing Extension.
[0091] After reaching a maximum flexion angle during swing at 408 , the knee begins to extend forward. During the early Swing Extension period, the spring energy stored during late Swing Flexion is then released, resulting in power output seen at 505 in FIG. 5B . During the remainder of Swing Extension, the human knee outputs negative power (absorbing energy) to decelerate the swinging leg in preparation for the next stance period. During terminal Swing Extension, the knee can be modeled as a flexion spring in series with a variable damper, storing a small amount of energy in preparation for early stance (at 507 ). After the knee has reached full extension, the foot once again is placed on the ground, and the next walking cycle begins.
[0092] An agonist-antagonist actuator described below implements these muscle-like actuation properties. The actuator comprises a plurality of springs, mechanical transmissions, and active elements where each spring is in series with an active element via a transmission, and each spring-transmission-active element combination are in parallel and capable of opposing one another in an agonist-antagonist manner. The components of the agonist-antagonist actuator are listed in Table 1 with their functional purposes outlined.
[0093] The Agonist-antagonist actuator: An Example
[0094] In FIG. 6 , one implementation of the actuator is shown as an example. For this particular actuator form, the active element comprises a motor in parallel with a variable damper. The flexion and extension motors can control the position of flexion and extension nuts, respectively, via ballscrew mechanical transmissions. As seen in FIG. 6 , two side-by-side actuators are attached at their upper ends to a cross-rod 601 which provides a connection point to the upper link 603 of the joint mechanism. The upper link 603 is connected to the lower link 605 at a joint 607 .
[0095] The actuator that extends along the left-hand side of the upper and lower links 603 and 605 as seen in FIG. 6 includes an extension nut 611 that engages with and compresses an extension spring 613 . The extension spring 613 is positioned between the extension nut 611 and a linear bearing 617 which is attached to the lower link 605 . An extension ballscrew seen at 621 connected via a gearbox (not shown) to the armature of an extension motor 623 . An extension nut guidance shaft 625 is attached to the case of the motor 623 and extends downwardly from the motor 623 through the extension nut 611 and the linear bearing 617 to a shaft endcap 629 . The guidance shaft 625 prevents the extension nut from rotating so that, as the extension motor 623 rotates the extension ballscrew 621 , the extension nut 611 moves longitudinally with respect to the cross-rod 601 and the motor 623 , varying the joint angle at which the extension nut engages with the extension spring 613 . Thus, the extension motor 623 can compress the extension spring 613 as the extension nut 611 is driven downward to increase the length of the actuator and extend (increase) the joint angle.
[0096] The actuator that extends along the right-hand side of the upper and lower links 603 and 605 as seen in FIG. 6 includes a flexion nut 631 that engages with and compresses a flexion spring 633 . The flexion spring 633 is positioned between the flexion nut 631 and a linear bearing 637 which is attached to the lower link 605 . A flexion ballscrew seen at 641 connected via a gearbox (not shown) to the armature of a flexion motor 643 . A flexion nut guidance shaft 645 is attached to the case of the flexion motor 643 and extends downwardly from the motor 643 through the linear bearing 637 and the flexion nut 631 and the to a flexion shaft endcap 649 . The flexion nut guidance shaft 645 prevents the extension nut from rotating so that, as the flexion motor 643 rotates the flexion ballscrew 641 , the flexion nut 631 moves longitudinally with respect to the cross-rod 601 and the flexion motor 643 , varying the joint angle at which the flexion nut engages with the flexion spring 633 . Thus, the flexion motor 623 can compress the flexion spring 633 as the flexion nut 631 is driven upwardly to decrease the length of the actuator and decrease the joint angle during flexion.
[0097] A variable damper is connected in parallel with each of the motors. An extension variable damper seen at 651 is connected in parallel with the extension motor 623 and a flexion variable damper seen at 653 is connected in parallel with the flexion motor 643 .
[0098] Through the independent control of flexion and extension nut positions, the actuator length at which the flexion and extension springs are engaged can be independently controlled (Muscle-Like Property 3 ). Furthermore, the flexion and extension motors can compress each series spring simultaneously without the joint rotating where each spring exerts an equal but oppositely opposed force.
[0099] If the series springs are hardening springs where spring stiffness increases with increasing compression, joint stiffness can be effectively controlled through this agonist-antagonist motor action (Muscle-like property 4 ). After the motors co-contract and compress the flexion and extension springs to a desired spring deflection and a desired actuator stiffness, to maintain that stiffness, the variable dampers can output high damping levels to impede ballscrew rotation at low power requirements.
[0100] Since each motor is in parallel with each variable damper, both motors can be turned off while still maintaining spring deflection and overall actuator stiffness (Muscle-Like Property 2 ). The actuator can also dissipate mechanical energy at low power (Muscle-Like Property 2 ).
[0101] In the actuator form of FIG. 6 , the ballscrew transmissions are backdrivable. Hence, when an external agent compresses or lengthens the actuator, energy can be dissipated using the variable dampers. Since each variable damper is in parallel with each motor, during such a dissipative action, the motors can act as generators to store electrical power for later use. Finally, zero actuator force can be achieved at zero power consumption (Muscle-Like Property 1 ). If the motors move the ballscrew nuts away from their respective spring element, the actuator will output zero force and no energy is required to maintain that force.
[0102] Component Implementations
[0103] Active Element. Depending on the application, each active element could be either a motor or a variable damper/clutch, or a combination of these elements. If the active element includes a variable damper/clutch, it could be implemented using hydraulic, pneumatic, friction, electrorheological, magnetorhelogical, hysteresis brake, or magnetic particle brake damping/clutching strategies. The preferred mechanism for damping control is a hysteresis brake because the zero power damping level is negligible. This feature is important because the variable damper is behind the mechanical transmission where any strain rate dependent, low-end viscous or frictional effect would likely be amplified.
[0104] If the active element includes a motor, it could be any electric motor, brushed or brushless. It could also be a hydraulic or pneumatic cylinder or other mechanical power-producing elements such as artificial muscle, piezoelectrics or nitinol wire.
[0105] Spring. The springs could be implemented as linear or torsional spring elements. They may be metal die springs, carbon fiber leaf springs, elastomeric compression springs, or pneumatic springs. For the preferred implementations described in this specification, the springs are die compression springs.
[0106] Mechanical Transmission. The mechanical transmissions could be implemented as linear or torsional transmission elements. They could be harmonic drives, ballscrew drives, leadscrew drives, or any other mechanical transmission known in the art. For the case where the active element and the series spring are both linear or both rotary elements, and no gear reduction is deemed necessary, the transmission would simply be a material linkage, connecting spring to active element. For example, if the active element is a linear artificial muscle, and the spring a linear, elastomeric element, then the spring would simply be attached directly to the artificial muscle. For the preferred embodiments described in FIGS. 6-10 , the mechanical transmissions are ballscrew transmissions.
[0000]
TABLE 1
Mechanical components of the Agonist-Antagonist Actuator System
Component
Function
Spring
Store and release energy, absorb shock,
provide stiffness
Active Element
Control positive and negative work and
power, control effective spring
equilibrium length and stiffness,
generate electrical power, clutch to
engage series elasticity
Mechanical
Couple spring to active element, offer
Transmission
gear reduction between active element
and output, convert rotary active
element to linear spring element
[0107] Sensing Implementations
[0108] For the Agonist-antagonist actuator to function properly, there are various sensors required to measure the state of the various actuator components. The sensors required to enable general actuator operation and control are:
1) Position sensors located at the biomimetic joint axis to measure joint angle (a rotary potentiometer), and at the active element (motor/variable damper/clutch) rotor to measure total displacement of the element's drive shaft and additionally the active element's velocity (a shaft encoder). 2) A force sensor (strain gauges) to measure the actual torque borne by the joint. 3) A displacement sensor on each spring in order to measure the amount of energy stored.
[0112] Instead of directly measuring the deflection of the series springs (# 3 ), sensory information from #1 can be employed. By subtracting the biomimetic joint angle from the active element output shaft angle, it is possible to calculate the amount of energy stored in the motor series spring. Also, the series spring displacement sensor can be used to measure the torque borne by the joint because joint torque can be calculated from the series spring output force.
[0113] Many variations exist in the particular sensing methodologies employed in the measurement of the listed parameters. Although preferred sensory methods have been specified, it is noted here that what is critical is to capture the energy state of the spring elements and the velocities of interior points.
[0114] In the remaining sections, we present embodiments of the agonist-antagonist actuator capable of providing biologically realistic dynamic behaviors for an artificial ankle and knee joint.
[0115] An agonist-antagonist actuator for an artificial ankle joint
[0116] Mechanical Design
[0117] The ankle design comprises flexion and extension motors for the active elements, and corresponding flexion and extension transmissions and springs. The flexion and extension motors provide control of joint spring equilibrium position and stiffness, damping and nonconservative, motive force output. In the section to follow, we provide an example of how the agonist-antagonist actuator could be employed as an artificial ankle.
[0118] The Agonist-antagonist actuator, as used in an artificial ankle application, is shown in FIGS. 7A and 7B . An upper shin link 701 and a foot link 702 rotate with respect to one another about an ankle joint 705 as best seen in the side view, FIG. 7B . Two actuators extend in parallel alongside the shin link 701 . In the actuator seen at the left in FIG. 7A , a plantar flexion motor 711 drives a flexion ballscrew 713 that extends through a linear bearing 715 , a plantar flexion spring 717 and a plantar flexion nut 719 to an endcap 720 . The flexion motor 711 is attached to a crossrod 723 by a strut 725 . The dorsiflexion actuator is seen at the right in FIG. 7A and includes a dorsiflexion motor 731 which is attached at its lower end by a strut 735 to the cross rod 723 . A dorsiflexion ballscrew 741 is driven by the dorsiflexion motor and extends upwardly through a dorsflexion nut 743 , a dorsiflexion spring 747 , and a linear bearing 758 to an endcap 749 . The foot link 702 is attached to a leaf spring foot plate seen at 750 .
[0119] The description that follows explains how, during level-ground walking, the joint might be controlled for the swing, controlled plantar flexion (CP), controlled dorsiflexion (CD), and powered plantar flexion (CP) phases of gait. In addition, the description will explain how the joint might be controlled for stair/slope ascent and descent.
[0120] Level-Ground Walking: Swing Phase and CP
[0121] During early swing, the plantar flexion ballscrew nut 719 is positioned such that the ankle joint is dorsiflexed to achieve foot clearance. During terminal stance, three distinct control methods can be employed in preparation for heel strike and the CP phase. In human walking, the amount of energy stored during CP increases with increasing walking speed. To achieve this increase in energy with speed, the total angular deflection of the ankle can be increased with increasing speed and/or the quasi-stiffness or the actual stiffness of the ankle can be increased. Thus, in a first control approach, the effective spring equilibrium length of the actuator at heel strike could be increased with increasing walking speed. Here the spring equilibrium position of the joint is equal to the desired heel strike ankle angle. The effect of this control would be that more mechanical energy is stored in the dorsiflexion spring during CP as walking speed increases. In an alternate approach, during terminal swing both dorsi and plantar flexion motors 731 and 711 could do work on their respective series springs in a co-contraction control scheme. If the series springs are hardening springs (stiffness increases with increasing deflection), this co-contraction action would effectively increase the actual stiffness of the actuator, and the ankle joint across which the actuator spans. Still further, in a third approach, the quasi-stiffness of the actuator/joint could be increased or decreased during CP. For the ankle system shown in FIGS. 7A and 7B , the flexion and extension ballscrews are non-backdriveable. Hence, during CP, if the desired ankle stiffness can be achieved simply by compressing the dorsiflexion spring 747 , the dorsiflexion motor 731 can be turned off to conserve power. If a lower quasi joint stiffness is required, the dorsiflexion motor 731 can unwind the dorsiflexion spring 747 during CP, and if a greater quasi joint stiffness is required, the motor can compress the spring 747 during CP. Depending on the terrain (smooth or uneven), walking speed, and power consumption constraints, the control algorithm of the artificial ankle will select the appropriate ankle spring equilibrium and stiffness values for terminal swing/CP to achieve a smooth heel strike to forefoot strike transition.
[0122] It is noted here that in the invention described herein, there can be separate series spring stiffnesses for joint dorsi and plantar flexion, and these two sets of springs 717 and 747 can be selected to give distinct flexion and extension joint stiffnesses at little to no power consumption. If the motors change ankle position when minimal torques are applied to the joint, such as during the swing phase of walking, very little electrical power is required to change the spring equilibrium position of the joint. In the embodiment seen in FIGS. 7A and 7B , where the ballscrews 713 and 741 are non-backdriveable, the motors need not consume any electrical power to hold the joint's position even during ground contact. Controlling the joint spring set point at heel strike can be useful, for example, when the wearer switches shoes with different heel heights or when the terrain changes character (slopes/stairs and uneven terrain), thus changing the natural angle of the ankle joint when the foot is resting on a flat ground surface.
[0123] Level-Ground Walking: CD and CP Phases
[0124] During early CD in human walking, the ankle torque does not return to point 1 in FIG. 2 . Rather, the torque assumes a higher value compared to the torque values from points 1 to 2 . To achieve this higher torque output, the plantar flexion motor 711 has to move the plantar flexion nut 719 to reduce the gap between the nut and the plantar flexion spring 717 as the dorsiflexion spring 747 is being compressing during CP. This repositioning of the plantar flexion nut allows the plantar flexion spring to be engaged even before the dorsiflexion spring has released its energy, thus providing a higher torque during early CD than during CP.
[0125] During mid to terminal CD in human walking, the ankle torque versus angle curve becomes increasingly nonlinear as walking speed increases. In addition, peak ankle power and the net ankle work during stance increases with increasing walking speed (see FIG. 2 ). Thus, at 0.9 m/sec, when the human ankle, on average, stores as much energy as it releases, the mechanical response of the artificial ankle during CP will, on average, be dictated by the series, plantar flexion spring. That is to say, the stiffness of the plantar flexion spring will be tuned to correspond to the average, quasi-stiffness (slope of the torque-angle curve) of the human ankle during CD. To decrease the quasi-stiffness of the artificial ankle during CP, the plantar flexion motor would be controlled to unwind the plantar flexion spring, and to increase quasi-stiffness, the motor would compress the spring. Thus, as walking speed increases above 0.9 m/sec, the plantar flexion motor would compress the plantar flexion spring during CD to achieve the following characteristics 1) to increase the quasi-stiffness of the artificial ankle during CD and 2) to increase the power output and the positive work performed during PP. It is noted here that to achieve a passive, spring response during the stance period of walking, the flexion and extension motors can be turned off to conserve power since the ballscrews are nonbackdriveable.
[0126] From {1} {2}, it has been shown that the maximum dorsiflexion ankle torque during level-ground walking is in the range from 1.5 Nm/kg to 2 Nm/kg, i.e. around 150 Nm to 200 Nm for a 100 kg person. Further, the maximum controlled plantar flexion torque is relatively small, typically in the range of 0.3 Nm/kg to 0.4 Nm/kg. Because of these biomechanics, a uni-directional spring in parallel with the agonist-antagonist actuator of FIGS. 7A and 7B would lower the peak torque requirements of the actuator. The uni-directional spring would engage at a small or zero dorsiflexion angle (90 degrees between foot and shank) and would lower the peak torque requirements of the Agonist-antagonist actuator since the peak controlled plantar flexion torque is considerably smaller than the peak dorsiflexion torque. Thus, additional elements could be added to the design of FIG. 7 such as a parallel, uni-directional spring.
[0127] Stair/Slope Ascent and Descent
[0128] For ascending a stair or slope, the dorsi and plantar flexion motors would move the nuts to reposition the ankle joint to an appropriate angle given the nature of the stair/slope. Once the artificial toe is loaded at first ground contact, the plantar flexion spring compresses and stores energy. During this CD process the plantar flexion motor can compress the spring farther so that additional power is delivered to the walking robot or prosthesis/orthosis user during PP. After toe-off, the motors control the equilibrium position of the ankle in preparation for the next step.
[0129] During stair descent, the body has to be lowered after forefoot contact until the heel makes contact with the stair tread. See re reference {2}. During this CD phase, the plantar flexion motor unwinds the plantar flexion spring as the spring is compressing to effectively dissipate mechanical energy. Once the heel makes contact with the stair tread, the motor can be turned off so that the plantar flexion spring begins to store energy for release during PP. For slope descent, the ankle response is similar, except that mechanical energy is absorbed by the dorsiflexion motor during CP instead of during CD.
[0130] An Agonist-Antagonist actuator for an Artificial Knee Joint
[0131] The knee design comprises an extension motor and a flexion variable damper for the active elements, and corresponding flexion and extension transmissions and springs. The extension motor and the flexion variable damper provide control of joint spring equilibrium position and stiffness, damping and nonconservative, motive force output. In this implementation of the agonist-antagonist actuator, a flexion motor is not included in an attempt to simplify the mechanism. Since only a flexion variable damper is present, the flexion nut is mechanically grounded to the linear bearing since a flexion motor is not present to actively reposition the flexion nut. Hence, when the knee joint flexes and extends, the flexion ballscrew rotations, but that rotation does not introduce significant zero-power joint resistance because 1) the flexion ballscrew is highly backdriveable and 2) the flexion variable damper has a negligible low-end damping value. A preferred method for the flexion variable damper is a hysteresis brake because of its minimal low-end damping value. In the section to follow, I provide an example of how the agonist-antagonist actuator could be employed as an artificial knee.
[0132] The agonist-antagonist actuator, as used in an artificial knee application, is shown in FIGS. 8A and 8B . The actuator consists of an upper (thigh) link 801 and a lower (shin) link 803 which are rotatably connected at a joint 805 . As seen at the left of the lower link 803 , an extension motor 811 drives an extension ballscrew 821 that extends downwardly from the motor 811 through an extension nut 815 , an extension spring 817 , and a linear bearing 819 . An extension nut guidance shaft 825 prevents the extension nut from rotating as the extension ballscrew 813 rotates.
[0133] The mechanism on the right side of the lower link 803 is passive; that is, it does not include an active motor element but rather includes a flexion variable damper 831 and a flexion spring 833 . A flexion ballscrew 841 extends from the damper 831 downwardly through a linear bearing 843 , the flexion spring 833 and a flexion nut 847 . A flexion nut guidance shaft 851 prevents the flexion nut 847 from rotating as the extension ballscrew 841 rotates.
[0134] Level-Ground Walking
[0135] During level-ground walking, the joint is controlled for the swing, early stance flexion, mid-stance extension, and pre-swing phases of gait. In addition, as described below, the joint may be controlled for stair/slope ascent and descent. Beginning at heel strike, the stance knee begins to flex slightly in normal human walking ( FIG. 5 ). As was noted earlier, this flexion period, called the Stance Flexion phase, allows for shock absorption upon impact as well as to keep the body's center of mass at a more constant vertical level throughout the stance period. During this phase, the artificial knee shown in FIGS. 8A and 8B outputs a spring response, storing energy in preparation for the Stance Extension phase. Here the extension spring 817 stores energy, and then that energy is released during the Stance Extension phase. In this implementation of the agonist-antagonist actuator, the extension ballscrew transmission is non-backdriveable. Thus, if the desired actuator stiffness during Stance Flexion corresponds to the extension spring stiffness, the extension motor need not be active, reducing electrical power requirements. If a higher or lower quasi joint stiffness is desired, the extension motor 811 can compress or unwind the extension spring 813 during early stance knee flexion, respectively, by repositioning the extension nut 815 that acts on the extension spring 817 .
[0136] After maximum flexion is reached in the stance knee in normal human walking, the joint begins to extend, until maximum extension is reached. This knee extension period is called the Stance Extension phase. Throughout the first ˜60% of Stance Extension, the knee acts as a spring, releasing the stored energy in the extension spring from the Stance Flexion phase of gait. This first release of energy corresponds to power output P 2 in FIG. 5B . During the last ˜30% of Stance Extension, the artificial knee is controlled to absorb energy in the flexion spring 833 and then that energy is released during the next gait phase, or Pre-Swing. Here the energy from hip muscular work and the remaining stored energy in the extension spring 817 is then stored in the flexion spring 833 . To engage the flexion spring, the flexion variable damper 831 outputs a high damping value, locking the flexion ballscrew 841 , and forcing the flexion nut 847 to compress the flexion spring 833 . During this energy storage, if it is desirable to lower the effective quasi-stiffness of the joint, the flexion variable damper 831 can output lower damping values to allow the flexion ballscrew 841 to slip, and for energy to be dissipated as heat. Here again, as in the artificial ankle joint of FIGS. 7A and 7B , the flexion and extension springs of the agonist antagonist actuator of FIGS. 8A and 8B are precisely tuned such that biological knee mechanics can be achieved while minimizing power supply demands and overall artificial joint mass.
[0137] During late stance or Pre-Swing, a normal human knee of the supporting leg begins its rapid flexion period in preparation for the swing phase. During early Pre-Swing in the artificial knee joint of FIGS. 8A and 8B , as the knee begins to flex in preparation for toe-off, the stored elastic energy in the flexion spring 833 stored during Stance Extension is released. This second release of energy corresponds to power output P 3 in FIG. 5B . During this process, the flexion variable damper 831 can be used to modulate the amount of stored elastic energy in the flexion spring that is actually released to power the knee joint.
[0138] In normal human walking, as the hip is flexed, and the knee has reached a certain angle in Pre-Swing, the leg leaves the ground and the knee continues to flex. At toe-off, the Swing Flexion phase of gait begins. Throughout this period, human knee power is generally negative where the knee's torque impedes knee rotational velocity. In the artificial knee joint of FIGS. 8A and 8B , once the elastic energy from the flexion spring 833 has been released and the artificial leg has entered the swing phase, the knee joint typically has to absorb mechanical energy to decelerate the swinging lower leg. This can be done in two ways. First, the flexion variable damper 831 can be used to dissipate mechanical energy as heat and to decelerate the swinging artificial leg. In addition, during late Swing Flexion, the extension motor 811 can position the extension ballscrew nut 815 such that the extension spring 817 compresses and stores elastic energy for use during Swing Extension.
[0139] After reaching a maximum flexion angle during swing, a normal human knee begins to extend forward. For the artificial knee of FIGS. 8A and 8B , during the early Swing Extension period, the elastic energy stored during late Swing Flexion in the extension spring 817 is released, resulting in power output P 4 in FIG. 5B . This control action, once again, reduces the energy demands from the knee's power supply. In all cases, the flexion variable damper 831 can be used to precisely modulate the amount of power delivered to the swinging artificial leg from the stored elastic energy.
[0140] During the remainder of Swing Extension, the human knee typically outputs negative power (absorbing energy) to decelerate the swinging leg in preparation for the next stance period. As with Swing Flexion, this can be done in two ways. First, the flexion variable damper 831 can be used to dissipate mechanical energy as heat and to decelerate the swinging artificial leg. In addition, during late Swing Extension, the flexion variable damper 831 can output a relatively high damping value such that the flexion spring 833 compresses and stores elastic energy for use during Stance Flexion. Here a small amount of energy is stored in preparation for early stance (power P 1 ). After the knee has reached full extension, the foot once again is placed on the ground, and the next walking cycle begins.
[0141] In summary, the artificial knee shown in FIGS. 8A and 8B is capable of reproducing the positive power contributions P 1 , P 2 , P 3 and P 4 shown in FIG. 5 for level-ground walking
[0142] Stair/Slope Ascent and Descent
[0143] For stair/slope descent, a normal human knee performs negative work during stance where knee torque is in the opposite direction to knee rotational velocity. The agonist-antagonist actuator of FIGS. 8A and 8B can perform this negative work in two ways. First, the flexion variable damper 831 can be used to dissipate mechanical energy as heat and to decelerate the rotating artificial leg. In addition, during terminal stance, the extension motor 811 can position the extension ballscrew nut 815 such that the extension spring 817 compresses and stores elastic energy for use later to power Swing Extension to prepare the artificial leg for the next stance period.
[0144] For stair/slope ascent, during the swing phase the extension motor 811 can actively control knee position to accurately locate the foot on the next stair tread or slope foothold. Once the artificial foot is securely positioned on the stair tread or ground, the motor 811 can then deflect and store energy in the extension spring 817 . This stored elastic energy can then assist the knee wearer or humanoid robot to actively straighten the knee during the stance period, lifting the body upwards.
[0145] Finally, the agonist-antagonist actuator of FIGS. 8A and 8B allows for the “windup” phase of a catapult style control to occur at any desired time. This means much greater flexibility as to when large amounts of power can be efficiently generated and used. This flexibility is critical when designing an artificial knee that can be used for jumping. For such a movement task, energy has to be stored prior to the jump, and then the elastic energy has to be released at a precise time to facilitate a jumping action. Specifically for the agonist-antagonist actuator of FIGS. 8A and 8B , the flexion variable damper 831 would be controlled to output high damping to effectively lock the flexion ballscrew 841 . Following this action, the extension motor 811 would slowly compress the extension spring 817 . Once high powers are deemed necessary about the joint output, the flexion variable damper 831 would then be controlled to suddenly unlock to allow rapid rotation of the flexion ballscrew 841 and the release of elastic strain energy from the extension spring 817 .
[0146] Alternative Configurations of the Agonist-Antagonist Actuator
[0147] It should be understood that the agonist-antagonist actuator described herein could be implemented in a number of different ways. For example, an active element and transmission-spring combination could be positioned on each side of the artificial joint. This configuration, shown in FIG. 9 , has the advantage that when only one spring is being compressed, no off-axis bending torques are borne by the lower link seen at 901 . The lower link 901 is attached to the upper link 903 at a joint 905 . A crossbar strut 907 is rigidly attached to the lower link 901 . A linear bearing is attached to each end of the crossbar strut 907 and a ballscrew, one of which is seen at 909 , extends through the linear bearing. The ballscrew seen at 909 extends downwardly from a drive motor 911 through a variable damper 913 , the linear bearing, a spring 915 , and a ballscrew nut 917 to an end cap 919 .
[0148] In the agonist-antagonist actuator implementations shown in FIGS. 6 , 7 and 8 , when only a single spring is being compressed, the upper and lower links experience a bending torque because the pair of active element-transmission-spring combinations are on the same side of the joint axis. It should also be understood that more than two active element-transmission-spring combinations could be employed to actuate multiple degrees of freedom. For example, in FIG. 10 , four active element-transmission-spring combinations are shown to actuate a two degree of freedom joint. Still further, it should be understood that an agonist-antagonist actuation system can include active element-transmission-spring combinations than span two or more joints in a poly-articular architecture. The biomechanics of poly-articular actuation is discussed in the next section.
[0149] In the arrangement shown in FIG. 10 , the joint attaches an upper link 1001 to a lower link 1003 for rotation about two orthogonal axes. As seen in FIG. 10B , the upper link rotates in a first degree of freedom about an axis through the crossbar 1007 that is parallel to the long dimension of a crossbar 1009 , and in a second degree of freedom about an axis through the crossbar 1009 that is parallel to the crossbar 1007 . Four different actuators are attached from the ends of the crossbars 1007 and 1009 and all four have a like structure illustrated by the actuator at the left in FIG. 10A . An drive motor 1021 attached to the crossbar 1005 rotates a ballscrew 1022 that passes through variable damper 1027 and a linear bearing 1029 attached to the lower link 1003 . The ballscrew 1022 further extends through a series spring 1031 and a ballscrew nut 1033 to an endcap 1040 . For each degree of freedom, one of the motor-spring-damper mechanisms controls the rotation of the upper link 1001 with respect to the lower link 103 in one direction while an opposing motor-spring-camper mechanism attached to other end of the same crossbar controls the rotation in that degree of freedom in the other direction, thus providing agonist-antagonist actuator control in both degrees of freedom.
[0150] Agonist-Antagonist Actuators Spanning more than One Joint
[0151] In the foregoing description, the agonist-antagonist actuator mechanism contemplated by the present invention was described and specific examples were provided as to its use in ankle and knee actuation, and different illustrative implementations were described. For each of these implementations, the agonist-antagonist actuator spanned a single joint. In other implementations, an agonist-antagonist actuator may span more than one rotary joint. The functional purpose of poly-articular muscle architectures in the human leg is to promote the transfer of mechanical energy from proximal muscular work to distal joint power generation. See reference {10}. To capture truly biomimetic limb function, both muscle-like actuators and mono, bi, and poly-articular artificial musculoskeletal architectures are critical. Hence, it should be understood that the agonist-antagonist actuator described herein could span more than one artificial joint. For example, an active element-transmission-spring combination could act across the hip and knee of an artificial leg, or across the knee and ankle of an artificial leg.
[0152] The Biomechanics of Mono and Bi-Articular Leg Actuation
[0153] In the previous sections, an agonist-antagonist actuator was described and specific examples were provided as to its use in ankle and knee actuation. For each of these descriptions, the actuator was used as a mono-articular device, spanning only a single joint. In subsequent embodiments, we describe how mono-articular actuation strategies can be used in combination with bi-articular actuation strategies to better replicate biological limb dynamics and efficiency.
[0154] The functional purpose of bi-articular muscle architectures in the human leg is to promote the transfer of mechanical energy from proximal muscular work to distal joint power generation {10}. To better explain how bi-articular actuation effects biological limb energetics, we present a biomechanical model of the human musculoskeletal architecture in FIG. 11A {11}. By modeling the human leg, we seek to understand how leg muscles and tendons work mechanically during walking in order to motivate the design of efficient prosthetic, orthotic, and robotic limbs.
[0155] We hypothesize that a robotic leg comprising only knee and ankle variable-impedance elements, including springs, clutches and variable-damping components, can capture the dominant mechanical behavior of the human knee and ankle for level-ground ambulation. As a preliminary evaluation of this hypothesis, we put forth a simple leg prosthesis model, shown in FIG. 11A , that is motivated by the human leg musculoskeletal architecture {11}. The model seen in FIG. 11 includes a drive motor 1101 at the hip, a knee joint 1103 and an ankle joint 1105 . A musculo-skeletal model of human leg function in walking. The model comprises seven mono-articular series-elastic clutches and four bi-articular series-elastic clutches/variable-dampers. Only a single actuator 1101 acts at the model's hip joint. In (B) and (C), model predictions for ankle and knee are compared with human gait data, respectively. Here gait data are shown for a 70 kg study participant with a 0.9 meter leg length and a walking speed of 1.2 m/s. The model of (A) agrees well with the human gait data, suggesting that muscles that span the ankle and knee primarily act as variable-impedance devices during level-ground walking We vary quasi-passive model parameters, or spring constants, damping levels and times when series-elastic clutches are engaged, using an optimization scheme where errors between model joint behaviors and normal human joint biomechanics are minimized.
[0156] The capacity of the musculoskeletal leg model to capture human-like ankle and knee mechanics in level-ground walking is shown in FIGS. 11B and 11C , respectively. At each joint state (position and velocity), the leg model is in good agreement with experimental values of joint torque and power, suggesting that a robotic leg can produce human-like walking dynamics through the control of only knee and ankle impedance.
[0157] Mono-articular ankle mechanism. The ankle mechanism comprises mono-articular dorsi and plantar flexion springs that can be engaged or disengaged with series elastic clutch mechanisms (see FIG. 11A ). In FIG. 12A , the mechanical power for each ankle component is plotted versus percent gait cycle. At heel strike (0% cycle), the clutch for the ankle dorsiflexion spring is engaged, causing the spring to stretch and store energy during early stance plantar flexion. When the tibia begins rotating forwardly after forefoot contact, the ankle plantar flexion spring is engaged and continues to store energy throughout the controlled dorsiflexion phase, and then that stored energy is released to contribute to ankle powered plantar flexion at terminal stance. Mechanical power output for each component of the human leg model of FIG. 11A .
In (A), (B) and (C), the mechanical power of each model element is plotted versus percentage gait cycle for ankle, knee and hip, respectively. Here the gait cycle begins at heel strike (0%) and ends with the heel strike of the same leg (100%).
[0161] Mono-articular knee mechanism. The knee mechanism comprises mono-articular flexion and extension springs that can be engaged or disengaged with series elastic clutch mechanisms (see FIG. 11A ). In FIG. 12B , the mechanical power for each knee mono-articular component is plotted versus percent gait cycle. At heel strike (0% cycle), the clutch for the knee extensor spring is engaged, causing the spring to stretch during early stance knee flexion. Here the knee extensor spring inhibits the knee from buckling. As the knee extends from a flexed posture, the knee flexor spring is engaged at the point of maximum knee extension velocity, storing energy that is subsequently used during terminal stance to help lift the lower leg from the ground surface.
[0162] Ankle-Knee Bi-Articular Mechanism. The leg model's ankle-knee bi-articular mechanism comprises a spring that can be engaged or disengaged with two clutch mechanisms (see FIG. 11A ). A first clutch, or the distal clutch, attaches the series spring to a point between the ankle and knee joint, and a second clutch, or the proximal clutch, attaches that same spring to a point above the knee axis. After heel strike in human walking, the knee typically undergoes a flexion period. During that phase of gait, both the proximal and distal clutches are disengaged, and the bi-articular spring does not apply a force to the prosthesis skeleton. However, as the knee begins to extend (˜10% cycle), the proximal clutch engages, and the bi-articular spring stretches. When the knee is fully extended, the distal clutch changes from a disengaged state to an engaged state, and the proximal clutch disengages. Engaging the distal clutch mechanically grounds the bi-articular spring below the knee rotational axis, changing the ankle-knee mechanism from a bi-articular to a mono-articular device. As a consequence of this action, all the energy stored in the bi-articular spring is used to power ankle plantar flexion during terminal stance. Thus in summary, the ankle-knee mechanism allows energy from hip muscular/actuator work to be transferred to the ankle for late stance powered plantar flexion.
[0163] Knee-Hip Bi-Articular Mechanism. The leg model's knee-hip bi-articular mechanisms comprise a spring that can be engaged or disengaged with either a clutch or variable-damper mechanism (see FIG. 11A ). There are three knee-hip bi-articular mechanisms. The clutch of the knee-hip flexor is engaged during swing phase knee extension and begins storing energy its series spring. As a result of this control action, the lower leg is decelerated smoothly prior to reaching full knee extension. In addition, elastic energy is stored in the knee-hip flexor spring that is later released during the early stance period. The knee-hip flexor also undergoes an energy storage/release sequence that begins during stance knee extension. The stored energy is then released to power rapid knee flexion movements at terminal stance to lift the foot and lower leg from the ground surface. The clutch of the knee-hip extensor is engaged during terminal stance, storing energy that is later released to enhance knee extension. Finally, the iliotibial tract series-elastic variable-damper applies an extensor knee torque to offset the knee flexor torque applied by the ankle-knee bi-articular mechanism. During stance knee extension, the ankle-knee bi-articular spring is elongated, exerting a torque about the knee. At the same time the iliotibial tract series spring is elongated thereby applying an extensor torque at the knee. Thus, through the action of the iliotibial tract mechanism, the effect of the ankle-knee bi-articular mechanism on net knee torque is minimized.
[0164] In the human leg, the functional purpose of bi-articular muscle is to promote the transfer of mechanical energy from proximal muscular work to distal joint power generation {10}. Using the biomimetic architecture shown in FIG. 11A , the robotic leg can achieve ankle powered plantar flexion without the requirement of powering a large motor located at the ankle joint. Approximately ten joules of net work are transferred to the ankle from the knee and hip in the modeling results shown in FIGS. 11 and 12 .
[0165] In subsequent embodiments, we motivate the design of prosthetic, orthotic and robotic leg structures using the leg model of FIG. 11 .
[0166] Mono and Bi-Articular Actuation for a Transtibial Prosthetic Leg System
[0167] The prosthetic leg model of FIG. 11A suggests that leg prostheses could produce human-like joint mechanics during level-ground ambulation if a musculoskeletal leg architecture and a variable-impedance control paradigm were exploited. However, the proposed biomimetic leg prosthesis does not eliminate the need for knee and ankle actuators, but the model does suggest that nonconservative joint actuator work need not be performed during normal, steady state walking For some situations, positive joint actuator work is required. For example, for uphill locomotory function, some positive actuator work would be necessary, especially at the knee. Furthermore, ankle and knee torque control would be necessary to reject large whole-body force disturbances that threaten balance. Although joint actuation is still necessary, the proposed biomimetic design will increase the time between battery recharges or power supply refueling, and will reduce robotic limb noise production during level-ground walking.
[0168] In FIG. 13 , the design of the proposed transtibial ankle-foot system with mono and bi-articular mechanisms is shown. In FIG. 13A , the major components of the transtibial system are shown, including the mono-articular ankle mechanism at 1303 , the bi-articular ankle-knee mechanism at 1305 , and a flexible nylon cord at 1307 . FIG. 13B shows the monoarticular ankle mechanism in more detail. This mechanism comprising two motors 1313 , mechanical transmissions and series dorsiflexion springs at 1317 , and series plantar flexion springs at 1319 . FIG. 13C shows the bi-articular mechanism ( 1305 in FIG. 13A ) and FIG. 13D shows a schematic of the bi-articular mechanism, including two uni-directional clutches seen at 1321 and 1351 and a series spring at 1324 . The limb architecture largely reflects the leg model shown in FIG. 11A , except the mono-articular knee mechanism has been excluded as this basic musculoskeletal structure is still intact in transtibial amputees.
[0169] The ankle mechanism 1303 seen in FIG. 13B comprises two agonist-antagonist, series-elastic actuators acting across the ankle joint. The foot-ankle design is similar to that described earlier in FIG. 7 . Each actuator has a small electric motor 1313 in series with one of the die springs 1317 or 1319 . Each series spring is a nonlinear hardening spring where spring stiffness increases with increasing spring compression. A non-backdriveable leadscrew 1331 is employed to covert rotary motor movement into linear movement of a leadscrew nut 1332 . A slider mechanism is seen at 1334 and a guide rod at 1335 . By re-positioning the leadscrew nut 1332 , each motor 1313 can independently vary the position of the ankle joint at which the series spring 1317 or 1319 becomes engaged. Such an ankle spring equilibrium control is important for many prosthesis functions, including slope and stair ascent and descent. The mono-articular ankle mechanism can also change ankle spring stiffness. During the swing phase each motor can simultaneously compress each nonlinear spring using a co-contraction control. Since spring stiffness increases with increasing deflection, the more the motor system compresses the springs, the stiffer the ankle joint becomes. Since the mechanical transmission is non-backdriveable, once a desired ankle stiffness has been achieved, the motors can be turned off to save electrical power. The foot-ankle design is similar to that described earlier in FIG. 7 .
[0170] In FIGS. 13C and 13D , the bi-articular ankle-knee mechanism and schematic are shown, respectively. The mechanism comprises two uni-directional clutches seen at 1351 and 1321 and a spring at 1324 . Each clutch is formed by two opposing cams (see 1353 ) that press against a shaft that directly connects to the spring. At the bottom of FIG. 13C , a foot assembly is seen at 1327 and the ankle axis is at 1328 . The ankle joint connection is seen at 1329 . In an engaged state, the cam configuration only allows for shaft movement in one direction. As can be seen in FIG. 13D , if both uni-directional clutches A and B are in the disengaged state, with each cam pair rotated outwardly with a small cam motor, the ankle and knee can freely rotate without the bi-articular spring exerting a force. When the ankle dorsi and plantar flexes in this disengaged state, the lower floating cam-clutch assembly 1321 translates on the linear guide rail 1367 . Furthermore, when the knee flexes and extends, the entire spring assembly translates on the linear guide rail 1367 . In distinction, when both clutches are in their engaged state, both ankle dorsiflexion and knee extension cause the bi-articular spring 1324 to stretch and store energy. Since the flexible nylon cord 1307 can resist tension but not compression, once the knee has reached full extension during the stance phase, knee flexion throughout terminal stance is not restricted by the bi-articular assembly, and all the stored energy in the bi-articular spring augments ankle powered plantar flexion.
[0171] Sensors for Active Ankle-Foot Prosthesis
[0172] For the active transtibial prosthesis to function properly, there are various sensors required to measure the state of the various system components and the intent of the amputee user. The additional sensors required to enable general prosthesis operation and control are:
4) position sensors located at the knee and ankle axes to measure joint angles (rotary potentiometers), and on each motor shaft to measure total displacement and velocity of each motor (a shaft encoder); 5) an inertial measurement unit (IMU) to determine the absolute position of the prosthesis in space; 6) a displacement sensor on each spring in order to measure the amount of force borne by a spring and the torque borne by the ankle joint; and 7) electromyographic (EMG) sensors to determine residual limb muscle activity.
[0177] Series spring displacement sensors can be used to determine the torque borne by the ankle joint because joint torque can be calculated from the agonist-antagonist spring output forces.
[0178] Control for Active Ankle-Foot Prosthesis
[0179] Local Prosthesis Control. A critical advantage of the human-like musculoskeletal prosthesis is that it allows the amputee user to directly control ankle powered plantar flexion. Because of the bi-articular ankle-knee mechanism, the extent of midstance knee extension defines how much energy is transferred to the prosthetic ankle for powering ankle plantar flexion at terminal stance. Since transtibial amputees generally have direct control over their knee, the biomimetic transtibial prosthesis allows for direct control over ankle power output.
[0180] The point in the gait cycle where the prosthesis series spring elements are engaged will largely be defined by joint state (position and velocity) and foot-ground interaction forces. The spring equilibrium angle for the ankle mono-articular mechanism will be equal to the ankle angle at first heel strike. Here heel strike will be detected using ankle torque sensing. For level ground ambulation, the heel strike ankle angle will be kept largely invariant with walking speed, but will be modulated from step to step for slope and stair ambulation.
[0181] The uni-directional clutch devices in the bi-articular mechanism will be controlled in a speed invariant manner. After heel strike in walking, the knee typically undergoes a flexion period. During that phase of gait, both bi-articular clutches will be disengaged, and therefore the bi-articular spring will not apply a force to the prosthesis skeleton. However, as the knee begins to extend (˜10% cycle), both clutches will be engaged, causing the bi-articular spring to stretch. Once the prosthesis enters the swing phase as detected by zero ankle torque, the bi-articular clutches will be disengaged so as to allow unrestricted knee and ankle movement throughout the swing phase.
[0182] Electromyographic (EMG) Control of Prosthetic Ankle Stiffness. The residual anatomy will allow amputees to voluntarily control joint stiffness via activation of the muscles in the residual limb. When walking on a rigid ground surface, the amputee user can select a low ankle stiffness, whereas when walking on a compliant terrain, the amputee can exploit a relatively high ankle stiffness.
[0183] Within the human body, such voluntary changes in joint stiffness are modulated by muscular co-activation. When antagonist muscles are simultaneously recruited, the net torque produced about the joint is related to the difference between the forces generated by the activated muscles, while the joint stiffness is related to their sum. Thus, activity from residual muscles is a natural control source for specifying the desired level of ankle stiffness. Since EMG provides a measure of muscular effort, it can be used in a “natural” manner to control stiffness of a joint. For a transtibial amputee, the muscles of the anterior and posterior compartment of the leg form the natural location from which to derive stiffness control signals.
[0184] A joint stiffness control signal is derived from the sum of the plantar flexion and dorsiflexion EMG amplitudes. The stiffness control signal will be related to stiffness via a straight line relationship with a zero-level control signal signifying the minimum available stiffness level and the maximum-level control signal signifying the maximum available stiffness level. Thus, limited muscle effort results in a low ankle stiffness while high muscular effort results in a high ankle stiffness. Using this control strategy, stiffness can be volitionally controlled by the amputee in a natural manner.
[0185] Although the device of FIGS. 13A-13D was described as a transtibial prosthesis, the mechanism could also be used as an orthosis or exoskeleton. The mechanism would be useful as an orthosis for an individual that suffers from an ankle pathology but generally has normal knee and hip function. For such an application, the mechanism would be placed in parallel with the human leg to augment ankle mechanics as a permanent assistive device.
[0186] Mono and Bi-articular actuation for an Artificial Ankle and Knee System
[0187] Description
[0188] A proposed artificial ankle and knee system is shown in FIGS. 14A-D . The mechanism could be employed for a transfemoral prosthesis, orthosis, leg exoskeleton, or robotic leg. The mono-articular ankle-foot 1303 and knee 1401 designs are identical to the structures described in FIG. 13B and FIG. 8 , respectively. However, the ankle-knee bi-articular mechanism 1410 is different from that proposed in FIGS. 13C and 13D . The bi-articular device of FIG. 13 has to be attached above the knee axis. In distinction, the bi-articular device 1410 of FIGS. 14A-14D attaches adjacent to the knee axis.
[0189] The bi-articular ankle-knee mechanism of FIGS. 14A-14D comprises a motor 1411 , non-backdriveable mechanical transmission 1413 , screw nut 1414 , series spring 1417 , a knee bi-articular connection 1421 , an ankle bi-articular connection 1431 , and a knee variable moment arm (VMA) device 1441 (seen in more detail in FIG. 14D ).
[0190] During level-ground walking, we describe how the ankle-knee bi-articular mechanism would be controlled for the swing, early stance flexion, mid-stance extension, and pre-swing phases of gait.
[0191] During the swing phase and early stance knee flexion, the screw nut 1414 is moved away from the series spring 1417 so that ankle and knee joint movements do not cause the spring to compress. However, when stance knee extension begins (18% gait cycle), the lead screw nut 1414 is moved by the motor 1411 until it engages the series spring 1417 . As a consequence of this control action, both knee extension and ankle dorsiflexion contributes to spring compression. Once the knee has reached full extension, the VMA device 1441 then minimizes the moment arm that the knee bi-articular connection makes with the knee axis of rotation. Because the knee moment arm is minimized, most of the strain energy stored in the bi-articular spring contributes to ankle powered plantar flexion at terminal stance. Generally, the knee moment arm 1441 can be controlled to effectively modulate the amount of energy release that occurs through the knee joint.
[0192] The VMA device comprises a small motor 1451 plus gear train 1455 , non-backdriveable lead screw 1459 , lead screw nut 1461 , and variable moment arm pin 1466 . A shin tube mount is seen at 1457 . When the motor 1451 rotates, the lead screw nut 1461 moves the variable moment arm pin 1466 across the variable moment arm slot 1471 . The pin is attached to the knee bi-articular connection. Thus, the VMA motor can actively control the perpendicular distance, or moment arm, between the knee bi-articular connection and the knee axis.
[0193] Summary
[0194] Several agonist-antagonist actuator variations comprising a plurality of active element transmission-spring combinations acting in parallel have described. These actuator embodiments combine active and passive elements in order to achieve high performance with minimal mass. In addition, the use of agonist-antagonist actuators as mono and poly-articular linear elements has been described. The combination of biologically-inspired musculoskeletal architectures and agonist-antagonist actuation strategies as described above provide novel, low mass, efficient and quiet biomimetic artificial limbs. These artificial limb structures may be used to advantage to provide improved orthotic and prosthetic devices and legged robotic mechanisms.
CONCLUSION
[0195] It is to be understood that the methods and apparatus which have been described above are merely illustrative applications of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.
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Artificial limbs and joints that behave like biological limbs and joints employ a synthetic actuator which consumes negligible power when exerting zero force, consumes negligible power when outputting force at constant length (isometric) and while performing dissipative, nonconservative work, is capable of independently engaging flexion and extension tendon-like, series springs, is capable of independently varying joint position and stiffness, and exploits series elasticity for mechanical power amplification.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 61/258,896, filed Nov. 6, 2009, the disclosure of which is incorporated herein by reference in its entirety.
FIELD
[0002] This technology relates to a serving tray and storage system. More particularly, the technology relates to a cracker serving tray and a mating storage container for housing the cracker serving tray when crackers are installed on the tray.
BACKGROUND
[0003] Crackers are typically stored in their product packaging, in Ziploc bags, or in plastic or glass containers to promote freshness. Crackers are often served in a bowl or on a tray. Applicant is unaware of any known containers that can be used to serve and store both round and square crackers in a storage tray inside a plastic storage container.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0004] FIG. 1 is a perspective view of an example cracker serving tray that may be utilized with differently shaped and sized crackers, with square crackers shown positioned on the tray;
[0005] FIG. 2 is an exploded perspective view of the example cracker serving tray of FIG. 1 , showing square crackers positioned on the tray;
[0006] FIG. 3 is a schematic view of square crackers
[0007] FIG. 4 is an inner end view of the end cap of the tray shown in FIG. 1 ;
[0008] FIG. 5 is a side view of the tray shown in FIG. 1 , with a spacer installed on the tray;
[0009] FIG. 6 is a top view of the tray shown in FIG. 1 with a spacer installed on the tray;
[0010] FIG. 7 is a schematic view of the leg and rail of the tray shown in FIG. 1 , depicting the angle between the two surfaces;
[0011] FIG. 8 is a face view of the spacer in an uninstalled position;
[0012] FIG. 9 is a perspective view of an alternative example cracker serving and storage system that has different end caps than that shown in FIG. 1 ;
[0013] FIG. 10 is a perspective view of an alternative example cracker tray shown with square crackers installed in the tray;
[0014] FIG. 11 is a perspective view of the cracker tray of FIG. 10 shown installed in a square container;
[0015] FIG. 12 is a perspective view of the cracker tray of FIG. 10 shown installed in a round container;
[0016] FIG. 13 is a perspective view of an example round container for use with the example cracker serving tray;
[0017] FIG. 14 is a side view of the container shown in FIG. 13 ;
[0018] FIG. 15 is a cross-sectional view of a cap that may be utilized with the example container of FIG. 13 ;
[0019] FIG. 16 is a perspective view of the cap of FIG. 15 ;
[0020] FIG. 17 is a perspective view of a rectangular container for use with the example cracker serving tray;
[0021] FIG. 18 is a side view of the container shown in FIG. 17 ;
[0022] FIG. 19 is a cross-sectional view of a cap for use with the rectangular container shown in FIG. 17 ;
[0023] FIG. 20 is a perspective view of the cap of FIG. 19 ;
[0024] FIG. 21 is a perspective exploded view of an example cracker serving tray being positioned in a round container;
[0025] FIG. 22 is a cross-sectional view of the cap installed on the round container of FIG. 13 ;
[0026] FIG. 23 is a perspective exploded view of an example cracker serving tray being positioned in a square container; and
[0027] FIG. 24 is a cross-sectional view of the cap installed on the square container of FIG. 17 .
DETAILED DESCRIPTION
[0028] The example cracker serving and storage system 10 incorporates a cracker serving tray 12 and one or more storage containers 14 for the serving tray 12 . The system 10 provides a combination of a tray 12 for holding and serving crackers 34 and a storage container 14 that is sized to accept the tray 12 therein without having to remove the crackers 34 from the tray 12 for storage purposes. The tray 12 simplifies the storage and serving of crackers 34 .
[0029] FIG. 1 depicts an example serving tray 12 for use with the system 10 . The tray 12 shown includes two rails 16 that together form a trough for receiving the crackers 34 there between. The two rails 16 are joined together at the ends by two end plates 18 . The end plates 18 keep the rails 16 spaced apart from one another in parallel relation. The rails 16 are elongated and are coupled at either end to legs 20 so that four legs 20 are utilized, one at each corner of the tray 12 . The legs 20 may be formed integrally with the rails 16 . The legs 20 maintain the rails 16 in spaced relation to a surface that the tray 12 sits on.
[0030] Each rail 16 forms a first angle A 1 relative to the perpendicular from the surface that the tray 12 sits on and the associated leg 20 forms a different angle A 2 relative to the perpendicular from the surface that the tray 12 sits on. As shown, the rails 16 form an upright V-shape and the legs 20 form an upside down V-shape. The V-shape of the rails 16 is designed to form a trough for holding the crackers 34 in place. An angle A 3 is positioned between the rails 16 and the legs 20 . This angle A 3 may be approximately 90 degrees. More particularly, this angle A 3 may be greater than or less than 90 degrees by 5, 10, 15, 20 degrees or more. One angle A 3 is about 92 degrees. The legs 20 may be substantially perpendicular to the rails 16 , or could be angled at a different angle, ranging from approximately 45 degrees to about 135 degrees. An example angle A 3 is shown in FIG. 7 .
[0031] The rails 16 face one another to form side walls of the tray 12 and are positioned at opposite angles relative to the surface that the tray 12 seats upon. The legs 20 maintain the rails 16 above the surface, and provide a space between the bottom of the rails and the surface in order to allow portions of a cracker 34 to seat about a surface between the rails 16 . As shown in FIG. 2 , a square saltine-type cracker 34 would have one corner 36 of the cracker 34 positioned between the rails 16 . The legs 20 have a height sufficient to elevate the corner 36 of the cracker 34 above the surface.
[0032] FIGS. 3 and 4 depict the end plates or caps 18 . In FIG. 3 , the end plate 18 is installed on the rails 16 and the outer side of the end plate 18 is visible. In FIG. 4 , the opposite side, or inner side 38 of the end plate 18 is shown in an uninstalled position. The end caps 18 may have a shape that mirrors the angles of the rails 16 so that the end cap 18 tapers from wider at the top to narrower at the bottom. The end caps 18 may be coupled to the rails 16 and positioned above the legs 20 , if desired, so that the end cap 18 does not rest on the surface that the tray 12 seats on. The end plates 18 may be substantially flat, or have a different profile. The end caps 18 could be used as additional trays 12 for storing something other than crackers 34 , such as forming a recess for holding cheese or dip.
[0033] The end caps 18 may include slots or tabs 22 for mating with the rails 16 . The example shown in FIGS. 3 and 4 includes both slots 22 for receiving tabs 22 that are positioned on the rails 16 , as shown in FIG. 2 . In addition, elongated tabs 22 are formed and extend outwardly from the inner sides 38 of the end plates 18 and the rails 16 seat against the elongated tabs 22 . Other attachment mechanisms may also be used to join the end caps 18 to the rails 16 , including mechanical and chemical means, such as soldering or gluing. At least one end cap 18 is utilized, but two end caps 18 may also be utilized, with one end cap 18 being positioned at either end of the tray 12 . An end cap 18 may be integrally formed with the rails 16 , if desired, as shown in FIGS. 9 and 10 .
[0034] FIGS. 5 and 6 depict a side and top view of the example cracker serving tray 12 . In FIG. 5 , the rails 16 are shown to extend along the length of the tray 12 . The rails 16 form the upper portion of the sides of the tray 12 and the legs 20 form the lower portion of the sides of the tray 12 . The legs 20 may be coupled directly to the rails 16 , as shown. In addition, a stabilizing section 40 may be positioned in the lower portion of the sides between the legs 20 and rails 16 , but spaced from the surface that the tray seats on. As shown in FIG. 6 , a space 42 is provided between the rails 16 for accepting a cracker 34 therebetween.
[0035] FIG. 8 depicts a spacer 24 , or sliding stop, that is provided for both maintaining a proper spacing between the rails 16 and for capturing crackers 34 between the end plate 18 and the spacer 24 . The spacer 24 may also be V-shaped and is slidable along the rails 16 and includes slots 26 that form arms 28 that seat over the side of the rails 16 so that the spacer 24 rests entirely on the rails 16 . The spacer 24 is shown positioned on or in proximity to the rails in FIGS. 1 , 2 , and 9 . The spacer 24 is sized such that it may slide along the length of the tray 12 , but stays in position to hold crackers 34 in position in the tray 12 . Friction created between the slots 26 , arms 28 , and rails 16 allows the spacer 24 to maintain its position once slid. The spacer 24 helps to retain the crackers 34 in an upright position in the tray 12 for ease of removal.
[0036] FIG. 9 depicts an alternative example cracker serving tray. This example is the same as the example shown in FIG. 1 , except that the end plates 18 are attached in a slightly different manner to the rails 16 . In this example, the rails 16 do not include smaller tabs 22 , like those shown in FIG. 2 . Instead, the rails 16 seat in slots 22 defined between tabs 22 on the end plates 18 . Other attachment mechanisms may also be utilized, if desired.
[0037] FIG. 10 depicts crackers 34 installed on an example cracker serving tray 12 . In this example, a rear end plate it not utilized and the forward end plate 18 is integrally formed with the rails 16 . In addition, the legs 20 are longer than those shown in prior examples. The spacer 24 is utilized to maintain the rails 16 in spaced relation. FIGS. 11 and 12 show the example serving tray 12 installed inside a container 14 according to the system. FIG. 11 depicts a square or rectangular tube container 14 and FIG. 12 depicts a round tube container 14 .
[0038] Decorative features 30 , advertising materials, or other indicia may be positioned on the end plates 18 , rails 16 or spacer 24 . FIGS. 10-12 show a decorative cut out being positioned on the end cap 18 and spacer 24 . Square crackers 34 are shown positioned in the tray 12 of FIGS. 10-12 , but other size crackers may also be utilized. It should be noted that the legs 20 , rails 16 , end caps 18 , and spacer 24 should be sized based upon the anticipated product to be stored in the tray 12 so that the product remains raised above the surface that the tray 12 sits on.
[0039] As is evident from FIGS. 11 and 12 , both the crackers 34 and the tray 12 can be stored in the tube 14 together so that the crackers 34 do not need to be removed from the tray 12 prior to storage. The container 14 shown in FIGS. 11 and 12 is made of a transparent plastic material and has a cover or lid 32 that is positioned at one end of the tube 14 . A lid 32 could be positioned at both ends of the tube 14 , if desired. In the example shown, the same tray 12 and crackers 34 can seat in either a round container 14 or a square container 14 . Both tubes 14 may be included with the system 10 or a single tube could be included. Certain sized crackers 34 may fit better in one tube than in the other. While round, oval, and rectangular crackers are not shown, it will be recognized that any size crackers can be used with the system.
[0040] FIGS. 13-16 depict greater details concerning the round storage container 14 . The round container 14 is tube-like and has one end 44 that is closed and another end 46 that is open. The open end 46 is used for inserting the cracker serving tray 12 , as shown in FIG. 21 . The open end 46 of the tube 14 includes screw threads 48 for mating with a cap 50 . The cap 50 may be plain, as shown, or include indicia, advertising materials, designs, or the like, as known by those of skill in the art. The cap 50 is shown installed on the tube in FIG. 22 . The cap 50 has screw threads 52 for mating with threads 48 on the container 14 .
[0041] FIGS. 17-20 depict greater details concerning the square storage container 14 . The square container 14 is tube-like and has one end 44 that is closed and another end 46 that is open. The open end 46 is used for inserting the cracker serving tray 12 therein, as shown in FIG. 23 . This container 14 includes an insert-type cap 54 , that is inserted into the opening 46 of the container 14 and seats snugly in the opening 46 to close the container 14 . The lid 54 has a lip 56 so that the lid 54 cannot easily be forced too far into the container 14 . In addition, a tab 58 is coupled to one or more corners of the lid 54 and is used to assist in removing the lid 54 from the container 14 . FIG. 24 shows the lid 54 installed on the opening 46 of the container 14 .
[0042] Any type of material may be utilized with the example cracker tray 12 and storage container 14 that is known to those of skill in the art. For example, the tray 12 could be plastic, metal, glass, or other known materials. The container 14 could be transparent or opaque and may be made of a plastic or other material. The tray 12 and spacer 24 may be made of the same materials or different materials. The tray 12 could be any color desired or clear and transparent. The container 14 could also be any color desired. One material that may be used for both the tray 12 and the container 14 is polypropylene.
[0043] Different sizes and types of crackers 34 may be installed on the tray 12 if desired. The containers 14 completely enclose the crackers 34 installed on the tray 12 so that they are not exposed to humidity or moisture during storage.
[0044] Any size tray 12 may be utilized. The container 14 should be large enough to accept the tray 12 with crackers 34 installed inside the container 14 . The containers 14 shown are round or square, but could be other shapes and sizes. For example, the containers could be rectangular, oval, or other shapes. The containers 14 shown have a lid 32 installed at one end thereof, but could have lids 32 at both ends if desired. The lid 32 may be the same type of material as the container 14 , or a different type of material. For example, the container 14 could be opaque while the lid 32 is transparent to allow a user to view the interior of the contents of the container 14 .
[0045] In use, the user assembles the tray 12 , if necessary, by inserting the tabs on the rails into the slots on the end caps. Then the spacer 24 may be positioned over the rails 16 so that each arm rests on an exterior surface of each rail 16 . Then crackers 34 may be positioned in the tray 12 so that they rest against an end plate 18 and the spacer 24 is slid along the rails 16 until it abuts and captures the crackers 34 in the tray 12 . When the user is finished using the tray 12 and crackers 34 still remain in the tray 12 , the user may position the tray 12 and crackers 34 inside a storage container 14 . The lid 32 is then placed on the storage container 14 to provide an air-tight fit. The tray 12 could also be stored in the container 14 without any crackers 34 installed on the tray 12 .
[0046] While the above description is in the context of crackers 34 , other similar materials could be stored in the container 14 . For example, recipe cards or photographs, or other food items could be stored in the container 14 . One example of other food would be sliced bread, pita bread, bagels, cookies or similar food items. The container 14 and tray 12 would need to be sized accordingly.
[0047] The term “substantially” or “substantial,” as used herein, is a term of estimation.
[0048] While various features of the claimed invention are presented above, it should be understood that the features may be used singly or in any combination thereof. Therefore, the claimed invention is not to be limited to only the specific embodiments depicted herein.
[0049] Further, it should be understood that variations and modifications may occur to those skilled in the art to which the claimed invention pertains. The embodiments described herein are exemplary of the claimed invention. The disclosure may enable those skilled in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the invention recited in the claims. The intended scope of the invention may thus include other embodiments that do not differ or that insubstantially differ from the literal language of the claims. The scope of the present invention is accordingly defined as set forth in the appended claims.
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A cracker serving and storage system includes a tray defining a trough having at least two sides and a slidable spacer configured to couple to the two sides and slide along the trough to capture the crackers in the tray. A storage container is also provided for storing the crackers and tray therein. A method for storing and serving crackers includes providing a cracker tray, positioning crackers in the tray, providing a spacer, and positioning the spacer between the rails behind the crackers to hold the crackers in position in the tray.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved veranda tent, more particularly a veranda tent of the type used as a sunshade at the exterior side, substantially the upper side, of a veranda or the like.
2. Description of the Related Art
It is known that the most efficient sunshade is formed by a tent cloth in any material which is provided alongside the exterior side above the roof of the veranda.
Such veranda tent, anyhow, may also be used in itself, in other words, as an actual tent.
The guides for such a veranda tent almost always have a length which is equal to the depth of the veranda, in such a manner that the tent cloth, when it is completely unwound, covers the complete upper surface of the veranda.
In order to still reduce the incidence of light, it has already been proposed to have the aforementioned guides protrude over the lower edge of the veranda roof in order to obtain thereby that the tent cloth, when it is completely unwound, protrudes over the lower edge of the veranda roof.
The disadvantage of such a construction, anyhow, is that, when the tent cloth is wound up, the aforementioned guides always keep protruding over the lower edge of the veranda roof which is no esthetic sight, on one hand, and which often forms a danger if the height of the veranda is relatively small, on the other hand.
SUMMARY OF THE INVENTION
The present invention aims at an improved veranda tent which allows to unwind the roll of cloth past the lower edge of the roof pane of the veranda but whereby, when the tent cloth is wound up, no protruding parts are present under the roof edge of the veranda cloth.
To this aim, the improved veranda tent showing the aforementioned and other advantages consists of a winding and unwinding mechanism provided in a top casing and whereby the deployment lath of the tent cloth can be moved in guides, characterized in that the aforementioned guides each are formed of two parts, namely fixed guides and movable guides, whereby these movable guides are movable in lengthwise direction in respect to the fixed guides and whereby the movable guides can be moved from the deployment lath.
In an advantageous form of embodiment, the fixed guides will be constructed as exterior guide, whereas the movable guides are constructed as interior guide. In another form of embodiment, the movable guides, respectively interior guides, may be realized in a telescopic manner.
BRIEF DESCRIPTION OF THE DRAWINGS
With the intention of better showing the characteristics of the invention, preferred embodiments of an improved veranda tent according to the invention are described hereafter, by way of example, without any limitative character, with reference to the accompanying drawings, wherein:
FIG. 1, in a very schematic manner, in perspective represents a veranda provided with an improved veranda tent according to the invention, whereby the tent cloth is in wound-up position;
FIG. 2 is a view similar to that of FIG. 1, whereby, however, the tent cloth is in unwound position;
FIG. 3 represents a top view of the veranda tent according to the invention;
FIG. 4 represents a view according to arrow F4 in FIG. 3;
FIG. 5, on a larger scale, represents the part which is indicated by F5 in FIG. 3;
FIGS. 6, 7, 8, 9 and 10, on a larger scale, represent cross-sections according to the lines VI--VI, VII--VII, VIII--VIII, IX--IX and X--X in FIG. 3;
FIG. 11 represents a top view similar to that of FIG. 3, however, with the tent cloth in an intermediate position;
FIG. 12 represents a top view similar to that of FIGS. 3 and 11, however, with the cloth tent in the completely unwound position;
FIGS. 13 to 15 represent an alternative embodiment for a connection between the interior guide and the exterior guide according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1 and 2, a veranda 1 is represented above which an improved veranda tent according to the invention is provided.
This veranda tent substantially consists in a top casing 2 wherein the winding mechanism for the tent cloth 3 is situated, and, towards each extremity of this top casing 2, exterior guides, 4 and 5, respectively, extending over the complete depth of the veranda 1, in other words, from the top casing 2 up to the lower edge of the roof pane.
These exterior guides 4-5 consist of a substantially U-shaped profile, the open sides of which are directed towards each other.
With these exterior guides 4 and 5 cooperate interior guides, 6 and 7, respectively, in which latter the extremities of the deployment lath 8, to which the tent cloth 3 is attached, can be moved.
These interior guides 6-7 substantially show a T-shape which is rotated 90°.
The complete driving mechanism for the tent cloth 3 is situated in the top casing 2, whereby this driving mechanism substantially is formed by a shaft 9 to which the second extremity of the tent cloth is attached and upon which this latter can be wound; a not represented electric motor which, for example, can be provided in the shaft 9 in order to wind and unwind the tent cloth 3; and at each extremity of the shaft 9 a reel, 10 and 11, respectively, at which one extremity of a cable, 12 and 13, respectively, is fixed.
The exterior guides 4 and 5, over almost the largest part of their length, show rails, 14 and 15, respectively, on one hand, which may serve as guides for rollers 16, and rolling surfaces 18-19, respectively, for guide wheels 20 and 21, whereby the rollers 16 and 17 each are mounted on a shaft 22 and 23, whereupon, in this form of embodiment, the guide wheels 20 and 21 are fixed, too.
The rollers 16 and 17 show a diabolo-shape, in such a way that they do not only form a vertical, but also a lateral guide, whereas the guide wheels 20 and 21 are simple flat rollers.
The shafts 22 and 23 are attached in the respective interior guides 6 and 7, whereby the wheels 16-17 and 20-21 are attached in an appropriate manner freely rotatable, but axially immobile, at the shafts 22 and 23.
Starting from the pair of reels 10 and 11, the pair of cables 12 and 13 run over a plurality of pulleys 24, 25, 26, 27 and 28, and subsequently disappear in the deployment lath 8 wherein the extremity 29 of cable 12, by the intermediate of a tension spring 31 is connected to the extremity 30 of cable 13.
The aforementioned pulleys 24 to 28 are always fixed freely rotatable, but axially immobile, on shafts which, as becomes clear from the FIGS. 6 to 10, themselves are fixed in an appropriate manner, respectively in the exterior guides 4-5, the interior guides 6-7 and the deployment profile 8, in such a manner that the cables 12 and 13 can pass freely through these exterior guides 4-5, respectively interior guides 6-7.
The second and fourth pulleys 25 and 27 are provided at the lower free extremity of the exterior guides 4-5, respectively the interior guides 6-7, whereas the third pulleys 26 are provided at a distance from the lower free extremity of the interior guides 6-7 which is somewhat larger than the length of the interior guides 6-7 which desirably extends beyond the exterior guides 4-5.
Towards each extremity, the deployment lath 8 is provided with a protrusion 32 situated in a space 33 in the interior guides 6 and 7, whereby the interior guides 6 and 7, towards each extremity, at least at the location of the space 33, are closed by means of a wall, 34 and 35, respectively, which, in this form of embodiment, forms an abutment for the aforementioned protrusions 32 of the deployment lath 8.
Obviously, such an abutment might also be formed by a pin or pin-like structure.
Finally, at the outer wall of each interior guide 6-7, more particularly towards the upper free extremity thereof, a protrusion 36 is provided which, for example, is triangular, whereas towards the upper extremity of each exterior guide 4 and 5 a pin 37 is provided in this latter with which the aforementioned protrusion 36 can cooperate, the free extremity of which preferably is triangular, too.
The pin 37, under the influence of a pressure spring 38, is always pushed towards the interior guide 6 or 7 concerned.
The functioning of the veranda tent according to the invention is very simple and as follows.
In the position whereby the tent cloth 3 is wound up, the deployment lath 8 is situated with its protrusions 32 against the abutments 34 of the interior guides 6 and 7, whereby these interior guides 6-7 also are situated in their uppermost position, more particularly the position as shown in FIG. 5, whereby the protrusions 36 are situated behind the pins 37 of the guides 4-5.
When the tent cloth 3 has to be unwound according to arrow P in FIG. 4, the shaft 9 has to be driven counter-clockwise in this FIG. 4, in other words, according to arrow Pl.
This has as a consequence that the cables 12 and 13 will be wound onto the rolls 10 and 11 according to P2, whereby these cables, so to say, exert a tension upon the pulleys 28 in the deployment lath 8, thereby moving this deployment lath 8 in the interior guides 6-7.
When the deployment lath 8, with its protrusions 32, touches the abutment wall 35 of the interior guides 6-7, at a certain moment the resistance of the pins 37 in the exterior guides 4 and 5 shall be overcome, as a result of which the protrusions 36 at the interior guides 6-7 shall push the pins 37 inwards and thereby shall move alongside these pins 37, in such a manner that the interior guides 6 and 7 move, by means of the wheels 16-17 and 20-21, in the exterior guides 4-5 in order to finally protrude over rather a large part out of these latter guides, as indicated in FIGS. 2 and 12, in order to elongate, so to say, the exterior guides 4 and 5.
The extension of the interior guides 6 and 7 beyond the exterior guides 4 and 5 is stopped by either exactly determining the length of the cloth 3, by providing appropriate abutments, not represented in the drawings, between the interior guides 6-7 and the exterior guides 4-5, or still by means of electric contacts actuated by the cloth 3.
It is obvious that, in this manner, it is obtained that, for example, in the case of a veranda as shown in FIGS. 1 and 2, the cloth 3 can be brought beyond the lower edge of the veranda in a simple manner.
In order to rewind the cloth 3, it suffices to drive the shaft 9 in clockwise direction in FIG. 4, as a result of which the cloth 3 is pulling at the deployment lath 8 and this latter is taking along the interior guides 6-7.
In this way, it is obtained that the extensions of the exterior guides 4 and 5, formed by the interior guides 6 and 7, disappear in the exterior guides when the cloth 3 is wound up.
During all these movements of the cloth 3, the spring 31 will compensate the successive differences in diameter of the quantity of cloth 3 in respect to the rolls 10 and 11.
In FIGS. 13 to 15, an alternative embodiment of a locking between the interior guides 6-7 and the exterior guides 4-5 is shown.
Hereby, the protrusions 32 of the deployment lath 8 have an inclined surface 39 which can cooperate with the inclined surface 40 of a locking element 41 which can be shifted in a substantially transverse guide 42 which is provided at the lower free extremity of each interior guide 6-7.
In this guide 42, there is an abutment 43 provided for a spring 44 which permanently pushes the locking element 41 into the locked position, whereby in this latter position it cooperates with an opening 45 in the exterior guides 4-5.
In this alternative embodiment, when the veranda tent is opened, the interior guides 6-7 will remain locked in the exterior guides 4-5 until the protrusions 32 of the deployment lath 8 remove the locking elements 41 from the openings 45, by means of the cooperation of the inclined surfaces 39-40.
It is clear that the present invention is in no way limited to the form of embodiment described by way of example and shown in the accompanying drawings, but that such improved veranda tent can be realized in a variety of forms and dimensions without leaving the scope of the invention.
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Improved veranda tent of the type whereby the winding and unwinding mechanism is provided in a top casing (2) and whereby the deployment lath (8) of the tent cloth (3) can be moved in guides, characterized in that the aforementioned guides each are formed by two parts, namely fixed guides (4-5) and movable guides (6-7), whereby these movable guides (6-7) are movable in lengthwise direction in respect to the fixed guides (4-5) and whereby the movable guides (6-7) are movable in respect to the deployment lath (8).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/982,334, filed Oct. 24, 2007, entitled “Catheter Securement Device,” which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a securement device used to secure a medical article or medical article fitting to a patient.
[0004] 2. Description of the Related Art
[0005] It is often necessary to introduce fluids and liquid medications directly into a blood vessel of a patient. Various types of medical articles, such as catheters, are often used in combination with connectors and syringes. A catheter is essentially a tube inserted through an incision in the skin into a blood vessel in the patient's body, generally without surgery. A simple intravenous (IV) line is usually acceptable for introduction of fluids and liquid medications into a blood vessel for short term general use. IV lines are typically inserted into a patient's arm by inserting a catheter or some other medical article, containing a needle, which pierces the skin, into a blood vessel. The needle is removed and discarded, while the medical article remains in the blood vessel.
[0006] It is important to minimize movement of the inserted medical article. If the medical article is not properly secured in place, it may be inadvertently displaced from its intended location. Consequently, medication delivered through the IV line may be released at an incorrect position. Furthermore, repeated back and forth movement of the medical article, or pistoning, can cause irritation of the blood vessel, disrupt proper introduction of medications to the patient, and increase the potential for bleeding or infection at the medical article insertion site. If extensive movement occurs, the IV line could even come out of the patient, interrupting delivery of medication and requiring re-insertion, often with hospitalization.
[0007] In the past, medical articles, such as catheters, were typically taped into place on the patient's skin. However, taping is time consuming and labor intensive. Tape also collects bacteria and must be frequently removed and replaced. More importantly, taping is not necessarily effective for securing a medical article in place on a patient. Sutures have also been used to attach medical articles to patients. With sutures, the medical article is stitched onto the skin. Sutures, however, can also be a source of infection, can cause pain and inflammation, and can make it more difficult to clean around the insertion site. Sutures also require time and skill to apply, and can cause scarring.
[0008] More recently, manufactured medical article anchors or securing devices have become widely adopted. While various designs have been developed, these devices are typically relatively inefficient or difficult to operate or manipulate. Thus, engineering design challenges remain to providing reliable, secure, and efficient medical article anchoring devices. Accordingly, improved medical article anchoring devices are needed.
SUMMARY OF THE INVENTION
[0009] One aspect of the present invention thus involves a retainer for a medical article. The retainer comprises a body member forming a channel configured to receive at least a portion of a medical article, the channel having a longitudinal axis. The body member moves between an open position and a closed position, the portion of the medical article being secured in the channel at least when the body member is in the closed position. The retainer further comprises at least one or more actuators coupled to the body member and configured to move the body member to the open position so as to receive the portion of the medical article in the channel. The retainer further comprises a base portion disposed over at least a portion of the body member, the base portion having one or more passageways configured to receive at least a portion of the one or more actuators.
[0010] Another aspect is a retainer for a medical article. The retainer comprises a body member that forms a channel configured to receive at least a portion of a medical article, the channel having a longitudinal axis. The retainer further comprises a latch member configured to move between a lock position and an unlock position. The latch member compresses the body member towards the longitudinal axis so as to secure the received portion of the medical article when in the lock position.
[0011] Another aspect of the present invention involves a retainer for a medical article. The retainer comprises a body member forming a channel configured to receive at least a portion of a medical article, the channel having a longitudinal axis. The body member is made of a first material and moves between an open position and a closed position, the portion of the medical article being secured in the channel at least when the body member is in the closed position. The retainer further comprises a base portion disposed over at least a portion of the body member, the base portion being made of a second material. The retainer also comprises at least one or more actuators coupled to the body member and being configured to move the body member to the open position so as to receive the portion of the medical article in the channel, at least a portion of the at least one or more actuators being made from a third material, the third material being different from at least one of the first material and second material. The retainer further comprises a pad supporting the base portion and having a lower surface, at least a portion of the lower surface being covered by an adhesive.
[0012] Further aspects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiments that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the drawings, the same element number indicates the same element in each of the views.
[0014] FIG. 1 is a perspective view of a securement device, according to one embodiment.
[0015] FIG. 2 is a perspective view of the securement piece of the securement device shown in FIG. 1 .
[0016] FIG. 3 is a perspective view of the shell of the securement device shown in FIG. 1 .
[0017] FIG. 4 is a perspective view of the securement device shown in FIG. 1 engaging a catheter fitting.
[0018] FIG. 5 is a perspective view of the securement device shown in FIG. 4 with the arms in a lowered position.
[0019] FIG. 6 is a front-right perspective view of a securement device, according to another embodiment.
[0020] FIG. 7 is a rear-right perspective view of the securement device shown in FIG. 6 .
[0021] FIG. 8 is a bottom perspective view of the securement device shown in FIGS. 6-7 .
[0022] FIG. 9 is a perspective view of the securement device shown in FIGS. 6-8 engaging a catheter fitting.
[0023] FIG. 10 is a perspective view of a securement device, according to another embodiment.
[0024] FIG. 11 is a perspective view of the securement body and hinge element of the securement device shown in FIG. 10 .
[0025] FIG. 12 is a bottom perspective view of the cover of the securement device shown in FIG. 10 .
[0026] FIG. 13 is a top perspective view of the cover of the securement device shown in FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Various embodiments of the invention will now be described. The following description provides specific details for a thorough understanding and enabling description of these embodiments. One skilled in the art will understand, however, that the invention may be practiced without many of these details. Additionally, some well-known structures or functions may not be shown or described in detail so as to avoid unnecessarily obscuring the relevant description of the various embodiments.
[0028] The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this detailed description section.
[0029] Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of items in the list.
[0030] To assist in the description of these components of the securement device, the following coordinate terms are used. A “longitudinal axis” is generally parallel to a portion of the medical article retained by the securement device, as well as parallel to the axis of a channel of the securement piece, through which the medical article extends. A “lateral axis” is normal to the longitudinal axis. A “transverse axis” extends normal to both the longitudinal and lateral axes. In addition, as used herein, “the longitudinal direction” refers to a direction substantially parallel to the longitudinal axis; “the lateral direction” refers to a direction substantially parallel to the lateral axis; and “the transverse direction” refers to a direction substantially parallel to the transverse axis. Also, the terms “proximal” and “distal” are used consistently with the description of the exemplary application. Thus, proximal and distal are used in reference to the center of the patient's body.
[0031] Turning now to the drawings, in a first embodiment, as shown in FIGS. 1-5 , a securement device 10 is configured to receive, secure, or stabilize a medical article or medical article fitting 12 , for example, an IV (intravenous) catheter, peripheral IV catheter, IV hub, IV luer, IV adaptor or extension, or any other suitable medical article or fitting. A “medical article fitting” as used herein includes any type of medical article fitting, attachment, accessory, hub, connector, and so forth, whether integral with the medical article or as a separate piece from the medical article. Furthermore, the term “medical article” as used herein may refer to a medical article alone, a medical article fitting alone, or a medical article in combination with any type of medical article fitting.
[0032] As shown in FIG. 2 , the securement device 10 includes a substantially longitudinal securement piece 20 having a central opening 19 for receiving a medical article 12 . The securement piece 20 may be substantially arch-shaped, semi-cylindrical, or generally contoured to fit over or around a medical article 12 . An upper region of the securement piece 20 preferably slopes generally in the longitudinal direction at an angle suitable to facilitate insertion of a needle, catheter, or other medical article into a patient. In one embodiment, the angle may be about 4-10°, or 5-9°, or 6-8°. Accordingly, a medical article 12 may be positioned within the sloped or angled securement piece 20 and directed toward the patient at an angle allowing for optimum flow, delivery, or drainage of any fluid to or from the patient.
[0033] One or more engagement members 23 or other protrusions extend from the inner surface of one or both side walls 24 , 25 of the securement piece 20 . The engagement members 23 may extend from the inner surface at an angle of 0-90° relative to the side walls 24 , 25 . Preferably, the engagement members 23 extend from the inner surface of the side walls 24 , 25 at an angle of 25-65°, or 35-55°, or approximately 45°.
[0034] In the illustrated embodiment, a row of engagement members 23 is positioned on the inner surface of each side wall 24 , 25 of the securement piece 20 . The engagement members 23 are arranged in two pairs on each side wall 24 , 25 , with the pairs extending in opposite directions, toward each other, at approximately 45° angles. Alternatively, every engagement member 23 may extend in the same direction as one another, or each engagement member may be oriented in a direction opposite its neighboring engagement members 23 .
[0035] Positioned generally toward the center of the top portion 30 of the securement piece 20 is a clearance opening 28 . The clearance opening 28 is of a size sufficient to receive a tab or other extension from a medical article 12 . In one embodiment, the clearance opening 28 is of a size sufficient to allow the tab or extension to pass or extend through the clearance opening 28 without contacting the sides or perimeter bordering the clearance opening 28 .
[0036] Extending from the bottom of the side walls 24 , 25 of the securement piece 20 are one or more arm receptacles 29 . In the illustrated embodiment, a pair of arm receptacles 29 extend from each side wall 24 , 25 . The arm receptacles 29 may be substantially semi-cylindrical or have any other configuration suitable for receiving ends of an actuator arm 40 or other member used to expand or “open” the securement piece 20 . In one embodiment, two spaced apart arm receptacles 29 extend from the bottom of each side wall 24 , 25 .
[0037] Two arms 40 are shown in the illustrated embodiment. The arms 40 are generally U-shaped and include substantially perpendicularly extending (relative to a centerline of the U-portion of the arm 40 ) end portions 41 . The arms 40 may alternatively be rectangular, circular, oval, or have any other shape or configuration suitable for attachment to the securement piece 20 , and for manipulation by a user to expand the securement piece 20 .
[0038] As shown in FIG. 2 , the end portions 41 of the arms 40 are securely positioned in the arm receptacles 29 . For example, the end portions 41 may be snapped or otherwise inserted into the arm receptacles 29 such that they are securely held therein, yet are permitted to freely rotate or pivot within the arm receptacles 29 . The arms 40 are preferably constructed of a hard, rigid material such as, for example, metal or plastic. The arms 40 may optionally be covered with a soft material 42 , for example, rubber, foam, or latex, to provide an aesthetically pleasing appearance and a comfortable gripping surface. The aim covering 42 also provides increased surface area to facilitate expanding or opening of the securement piece 20 via inward force applied to the arms 40 . The soft covering may optionally include ridges or ribs to increase traction and facilitate gripping and operation of the arms 40 .
[0039] A shell 31 optionally covers or encases the securement piece 20 . The shell 31 is preferably made of a soft material, for example, rubber, foam, or latex, to provide a more aesthetically pleasing appearance and increased comfort for a patient. As shown in FIG. 3 , the shell 31 includes a top portion 32 , which generally corresponds to and fits around the top portion 30 of the securement piece 20 . Extending downwardly from each corner of the top portion 32 is a shell wall 33 . One or more of the shell walls 33 optionally includes an inner portion 34 protruding inwardly toward the longitudinal axis of the securement piece 20 . The inner portions 34 may aid in preventing longitudinal movement of a medical article 12 through the securement piece 20 . Each shell wall 33 includes an opening 35 on its inner surface for receiving an arm receptacle 29 of the securement piece 20 . The opening 35 may have varying depths suitable for receiving arm receptacles 29 of varying sizes, or the opening 35 may be a hole that extends entirely through the wall 33 .
[0040] In the illustrated embodiment, two base portions 50 extend laterally from the shell walls 33 . The base portions 50 may be rigid, or may be generally flexible or contoured to conform to a specific patient site. A hydro-colloidal pad or other cushion may optionally be attached to an underside of each of the base portions 50 for providing increased patient comfort. The specific pad shape and size may vary. The underside of each of the base portions 50 (or of the cushions, if present) preferably includes an adhesive layer covered by a peelable strip 52 . The peelable strips 52 are removable such that the adhesive may be exposed and the base portions 50 may be adhered to a desired securement site.
[0041] Each base portion 50 preferably includes a separate peelable strip 52 such that the central opening 19 of the securement device 10 is not blocked by a peelable strip 52 . This allows the securement device 10 to be placed over the top of a medical article 12 before removing the strips 52 and adhering the device 10 to the patient. Alternatively, a single peelable strip may extend over the underside of both base portions 50 . In such an embodiment, the strip 52 is removed prior to attaching the securement device 10 to a medical article 12 . Alternatively, the securement device 10 may be affixed to a patient by applying adhesive tape over or around the device 10 or the base portions 50 and against the patient site.
[0042] In use, the arms 40 are raised into the “up” position, as shown in FIGS. 1 and 2 . An attendant squeezes the arms 40 toward each other, causing the central opening 19 in the securement piece 20 to widen so the securement device 10 may be placed over a medical article 12 . The attendant then releases the arms 40 , allowing the securement piece 20 to close or tightly conform around the medical article 12 , as shown in FIG. 4 . In this position, the engagement members 23 (possibly in conjunction with the inner portions 34 of the shell walls 33 , depending on the configuration of the medical article 12 ) secure the medical article 12 in place and substantially prevent it from moving longitudinally within the securement device 10 . The attendant may then lower the arms 40 , into the position shown in FIG. 5 , so they are not obtrusive. Finally, the attendant may remove the peelable strips 52 , exposing the adhesive, and press the base portions 50 against a patient to adhere the securement device 10 containing the medical article 12 to the patient's skin.
[0043] Turning to FIGS. 6-9 , in an alternative embodiment, a securement device 60 includes a substantially longitudinal securement body 62 including a central opening 64 for receiving a medical article 66 . The securement body 62 may be substantially arch-shaped, semi-cylindrical, or generally contoured to fit over or around a medical article. An upper region of the securement body 62 preferably slopes generally in the longitudinal direction at an angle suitable to facilitate insertion of a needle or other medical article into a patient. In one embodiment, the angle may be about 4-10°, or 5-9°, or 6-8°. Accordingly, a medical article may be positioned within the sloped or angled securement body 62 and be directed toward the patient at an angle allowing for optimum flow, delivery, or drainage of any fluid to or from the patient.
[0044] The upper portion of the securement body 62 preferably includes a clearance opening 65 . The clearance opening 65 is of a size sufficient to receive a tab or other extension from a medical article 12 . In one embodiment, the clearance opening 65 is of a size sufficient to allow a tab or extension to pass or extend through the clearance opening 65 without contacting the sides or perimeter bordering the clearance opening 65 . The securement body 62 optionally includes one or more notches 69 for accommodating one or more laterally extending members of a medical article. In one embodiment, a latch receptacle 70 or similar opening may be included in a side wall of the securement body 62 for receiving a latch of an optional cover, as described below.
[0045] One or more engagement members 67 or other protrusions preferably extend into the interior of the securement body 62 . The engagement members 67 may extend at an angle of 0-90° relative to the interior walls of the securement body 62 . Preferably, the engagement members 67 extend at an angle of 25-65°, or 35-55°, or approximately 45° relative to the interior walls. In the illustrated embodiment, two opposing engagement members 67 are positioned near the rear of, and extend into the interior of the securement body 62 at angles of approximately 45° relative to the side walls of the securement body 62 . Any other suitable number of engagement members 67 may alternatively be included on the securement body 62 .
[0046] The securement body 62 further includes one or more base portions 68 extending laterally from lower side regions of the securement body 62 . The base portions 68 may be rigid, or may be generally flexible or contoured to conform to a specific patient site. A hydro-colloidal pad or other cushion may optionally be attached to an underside of each of the base portions 68 to provide increased patient comfort. The specific pad shape and size may vary. The underside of each of the base portions 68 (or of the cushions, if present) preferably includes an adhesive layer, which may be covered by one or more peelable strips (not shown), as described in the first embodiment. The one or more peelable strips are removable such that the adhesive may be exposed and the base portions 68 may be adhered to a desired securement site.
[0047] In use, an attendant may pull the base portions 68 laterally away from each other to widen the central opening 64 so that it may be placed over a medical article 66 . The attendant may then release the base portions 68 so that the securement body 62 closes or securely conforms around the medical article 66 , as shown in FIG. 9 . Alternatively, the attendant may snap the securement body 62 over top of the medical article 66 . The attendant may then remove the peelable strips, exposing the adhesive, and press the base portions 68 against a patient to adhere the securement apparatus 60 containing the medical article 66 to the patient's skin.
[0048] As shown in FIGS. 10-13 , in another embodiment, a securement device 80 includes a cover 82 or lid for covering and gripping the securement body 62 . The cover 82 is preferably attached to one of the base portions 68 via a hinge, pivot joint, or similar structure. The hinge may take various forms. For example, a hinge may include a tongue 84 on the cover 82 and a groove 86 formed in a hinge element 72 on the base portion 68 . A hinge may alternatively include a conventional pin-hinge mechanism, a snap-fitting mechanism including a snap-arm and a snap-receptacle, or any other suitable hinge or pivot joint.
[0049] The cover 82 preferably includes a receiving region 87 configured to grip or squeeze the securement body 62 , and a lever 89 or handle for allowing an attendant to manipulate the cover 82 . The cover 82 further includes a latch element 88 for engaging the latch receptacle 70 in the securement body 62 . The latch element 88 is preferably supported on a release arm 90 , which is accessible via an opening 95 in the cover 82 . The release arm 90 is pressable toward the lever end of the cover 82 for releasing the latch element 88 from the latch receptacle 70 , which allows the cover 82 to be pivoted into the open position.
[0050] Any other suitable latch mechanism may alternatively be included. For example, the lever end of the cover 82 may include a latch element for engaging a latch receptacle supported on the base portion 68 opposite the one supporting the hinge element 72 . Alternatively, a latch element may be positioned on the base portion 68 and a latch receptacle may be included in the cover 82 . In another alternative embodiment, the hinge may be omitted and the cover 82 or lid may snap over the securement body 62 into receiving elements on both base portions 68 via latch or lock elements at both ends of the cover 82 .
[0051] In use, an attendant may pull the base portions 68 laterally away from each other to widen the central opening in the securement body 62 so that it may be placed over a medical article 66 . The attendant may then release the base portions 68 so that the securement body 62 closes or conforms around the medical article 66 , as shown in FIG. 10 . Because the gripping cover 82 is included, the securement body 62 does not necessarily have to securely grip the medical article 66 without the aid of the cover 82 , but it may optionally do so. The attendant may then pivot the cover 82 to the closed position, in which the latch element 88 engages the latch receptacle 70 . In this closed position, the walls of the receiving region 87 grip or squeeze the outer walls of the securement body 62 toward the medical article 66 such that the engagement members 67 securely grip or squeeze the medical article 66 . The attendant may then remove the peelable strips, exposing the adhesive, and press the base portions 68 against a patient to adhere the securement device 80 containing the medical article 66 to the patient's skin.
[0052] It is to be understood that not necessarily all objects or advantages disclosed herein may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition to the variations described herein, other known equivalents for each feature can be incorporated by one of ordinary skill in this art to construct a device and/or system in accordance with principles of this invention.
[0053] While the illustrative embodiments have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but by a fair reading of the claims that follow.
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A securement device ( 10 ) secures a medical article ( 12 ) to the body of a patient and prevents longitudinal movement of the medical article ( 12 ) relative to the securement device ( 10 ). The securement device ( 10 ) includes a base portion ( 50 ) that is disposed over at least a part of a securement piece ( 20 ). The securement piece ( 20 ) forms a channel ( 19 ) configured to receive at least a portion of the medical article ( 12 ). The device ( 10 ) includes at least one actuator ( 40 ). The at least one actuator ( 40 ) is coupled with the securement piece ( 20 ) and configured to move the securement piece ( 20 ) between open position and a closed position. When the securement piece ( 20 ) is in the open position, it can receive at least a portion of the medical article ( 12 ). When the securement piece ( 20 ) is in the closed position, it prevents the received medical article ( 12 ) from moving in the longitudinal direction relative to the securement device ( 10 ). In some embodiments the securement piece ( 20 ) has engagement members ( 23 ) extending from the inner surface of the securement piece ( 20 ). In an embodiment, the securement device ( 10 ) includes an opening ( 28 ) that receives an outwardly extending member of the medical article ( 12 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of fabricating a semiconductor device in which by use of an SOI (Silicon on Insulator) substrate an electric potential of a support substrate can be fixed, and also relates to a semiconductor device fabricated according to the method.
2. Description of the Related Art
An SOI substrate is a semiconductor substrate that has a structure in which an SOI layer and a support substrate are separated by a buried oxide film. A transistor formed on the SOI substrate, since the SOI layer thereon the transistor is formed is electrically isolated completely from the support substrate by a thick buried oxide film, has characteristics such as being small in the parasitic capacitance, not causing latch-up, being strong against the cross talk noise, and so on.
However, even when the SOI substrate is used, it is difficult to completely inhibit the cross talk from occurring between elements formed on the same substrate. As a countermeasure for this, there is a method in which an electric potential of the support substrate under the buried oxide film is fixed. However, in the case of a package whose support substrate side is covered with resin like a WCSP (Wafer-level Chip Size Package) being used, since direct electrical contact cannot be attained from the support substrate, it is necessary to form a contact from a wafer surface to the support substrate and thereby to establish electrical contact from the SOI layer side. At this time, in order to reduce the electrical resistance that is generated between the contact and the support substrate, a contact hole penetrating through an element isolation layer formed on the SOI layer and the buried oxide film is formed and, to the support substrate exposed at the bottom portion thereof, with the element isolation layer therein the contact hole is formed as a mask, ion implantation of a high concentration impurity is performed.
[Patent Literature No.1]
Japanese Patent Application Laid-Open (JP-A) No.11-354631
[Patent Literature No.2]
JP-A No. 2002-110951
[Patent Literature No.3]
JP-A No. 2002-83972
[Patent Literature No.4]
JP-A No. 9-283766
However, according to the method in which a contact hole is formed from the SOI layer side toward the support substrate and the ion implantation is performed to the support substrate at the bottom portion of the contact hole, in the case of a process where the miniaturization is advanced being used, an aspect ratio is increased; accordingly, there are worries in that the impurity may not sufficiently reach up to the support substrate.
Furthermore, even if the impurity could sufficiently reach the support substrate, a region where the impurity is implanted at a high concentration would be limited to the bottom portion of the contact hole. Accordingly, in the semiconductor device obtained according to such a method, over a region almost from the bottom portion of the contact hole to a lower portion of the element formation region, the impurity is not implanted at a high concentration. This will also cause the following problem.
In order to control the operation of the transistor formed in the element formation region in the SOI layer, in some cases, a electrical potential of the support substrate at the lower portion of the element formation region is manipulated, at this time, the manipulation is done by changing the electrical potential of a plug that buries the contact hole. However, as is noted above, in the region almost from the bottom portion of the contact hole of the support substrate to the lower portion of the element formation region, the impurity is not ion implanted at a high concentration; accordingly, the electrical resistance is high. Accordingly, in the region from the bottom portion of the contact hole of the support substrate to the lower portion of the element formation region, an electrical current cannot be flowed so much; accordingly, the supply of the electric charges to the support substrate at the lower portion of the element formation region is delayed. As a result, the manipulation of the electrical potential of the support substrate at the lower portion of the element formation region cannot be speedily performed.
SUMMARY OF THE INVENTION
In order to overcome the above mentioned problems, in the method of fabricating a semiconductor device according to the invention, an SOI layer that has an element formation region and an element isolation region through an oxide film on a substrate is formed, an impurity is ion implanted to the support substrate in the neighborhood of the oxide film so as to extend from the lower portion of the element formation region to the lower portion of the element isolation region to make the support substrate of a portion where the impurity is ion implanted low in the electric resistance, followed by heating the support substrate to form an element isolation layer in the element isolation region of the SOI layer, and thereby a plug that penetrates through the element isolation layer and the oxide film and reaches the low resistance region is formed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B , respectively, are a sectional view and a plan view showing a first embodiment according to the present invention.
FIGS. 2A and 2B , respectively, are a sectional view and a plan view showing the first embodiment according to the invention.
FIGS. 3A and 3B , respectively, are a sectional view and a plan view showing the first embodiment according to the invention.
FIGS. 4A and 4B , respectively, are a sectional view and a plan view showing the first embodiment according to the invention.
FIGS. 5A and 5B , respectively, are a sectional view and a plan view showing a second embodiment according to the invention.
FIG. 6 is a circuit diagram for explaining an effect of the second embodiment according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(First Embodiment)
FIGS. 1A through 4A are plan views showing a first embodiment according to the invention. Furthermore, FIGS. 1B through 4B are sectional views showing cross-sections when each of FIGS. 1A through 4A is cut along a dotted line XY. In the following, the first embodiment according to the invention will be explained with reference to the FIGS. 1 through 4 . The first embodiment according to the invention is a method of fabricating a semiconductor device with an SOI substrate.
Firstly, as shown in FIGS. 1A and 1B , a semiconductor substrate that has a buried oxide film 20 between a support substrate 10 and an SOI layer 30 (hereinafter referred to as SOI substrate) is prepared. The SOI substrate may be any one of a wafer-like one and a chip obtained by dividing a wafer into individual chips. Furthermore, it may be either of one that is formed according to a SIMOX (Silicon IMplanted Oxide) method and one that is formed according to a lamination method. Still furthermore, the SOI layer 30 has an element formation region and an element isolation region. In the neighborhood of the buried oxide film 20 of the support substrate 10 , an impurity is ion implanted at a high concentration of substantially 1E20 cm−-3, and thereby the neighborhood of the buried oxide film 20 of the support substrate 10 is made a low resistance layer 40 . The impurity is ion implanted so as to extend at least from the support substrate 10 at the lower portion of the element formation region to the support substrate 10 at the lower portion of the element isolation region. As far as the condition is satisfied, the impurity can be ion implanted anywhere in the neighborhood of the buried oxide film 20 of the support substrate 10 . For example, the ion implantation can be applied to an entire surface of the support substrate 10 . The ion implantation is performed through the SOI layer 30 and the buried oxide film 20 .
Then, the support substrate 10 is subjected to heat treatment. Since the impurity that is ion implanted to the support substrate 10 is diffused a certain degree owing to the heat treatment, an impurity that is ion implanted to the support substrate 10 is desirably low in the diffusion coefficient. This is because by suppressing the diffusion due to the heat treatment as low as possible, the electric resistance of the low resistance layer 40 formed by ion implantation of the impurity is suppressed from rising. For example, when the support substrate 10 is silicon, As and so on are desirable.
The above heat treatment is not necessarily applied immediately after the ion implantation of the impurity, and may be applied simultaneously with the heat treatment of a diffusion layer 70 when a transistor 60 is formed in the subsequent step or similarly simultaneously with the heat treatment when an element isolation region 50 is formed in the subsequent step. By thus performing, the number of times of the heat treatment can be reduced, the number of steps can be reduced, and thereby the diffusion of the impurity can be suppressed to the lowest possible limit.
Subsequently, as shown in FIGS. 2A and 2B , the element isolation layer 50 is formed in the element isolation region of the SOI layer 30 according to the LOCOS method and so on, and a transistor 60 that has a diffusion layer 70 in the element formation region on the SOI layer 30 is formed.
Then, as shown in FIGS. 3A and 3B , an interlayer insulating film 80 is deposited on the SOI layer 30 and the element isolation layer 50 . Furthermore, a contact hole 90 that goes through the interlayer insulating film 80 , element isolation layer 50 and buried oxide film 20 and reaches the support substrate 10 is formed.
Lastly, as shown in FIGS. 4A and 4B , an adhesion layer 95 made of TiN is formed at the bottom portion of the contact hole 90 , thereon a plug 100 made of W is deposited, and thereby the contact hole 90 is buried. Furthermore, in burying the contact hole 90 , instead of W, Poly-Si into which an impurity is ion implanted may be used. In this case, by making the impurity that is ion implanted in the support substrate 10 and the impurity that is ion implanted in the Poly-Si the same conductivity type, the Schottky barrier is inhibited from occurring between the support substrate 10 and the plug 100 .
As explained above, according to a method of fabricating a semiconductor device according to a first embodiment of the invention, when the impurity is ion implanted into the support substrate under the oxide film, the element isolation layer having the contact hole is not used as a mask. Since the impurity is ion implanted into the support substrate before an element and the element isolation layer are formed, the impurity can reach the support substrate irrespective of the aspect ratio of the contact hole.
Furthermore, instead of previously laminating the impurity ion implanted support substrate, buried oxide film and SOI layer each, the impurity is ion implanted to the support substrate of the completed SOI wafer. Accordingly, there is no chance that owing to the diffusion of the impurity that is ion implanted to the support substrate due to heat at the time of lamination, the electric resistance of a region where the impurity is ion implanted, that is, a low electric resistance layer becomes larger.
(Second Embodiment)
FIG. 5B is a plan view showing a second embodiment according to the invention. Furthermore, FIG. 5A is a sectional view showing a cross section when FIG. 5B is cut along a dotted line XY. In the following, the second embodiment according to the invention will be explained with reference to FIGS. 5A and 5B . The second embodiment according to the invention is a semiconductor device that uses an SOI substrate and corresponds to a semiconductor device fabricated by use of the first embodiment.
The second semiconductor device according to the invention is formed on a buried oxide film 20 formed on a support substrate 10 .
An SOI layer 30 and an element isolation layer 50 are disposed on the buried oxide film 20 . A semiconductor element 60 that has a diffusion layer 70 is formed in the SOI layer 30 . Furthermore, in a region close to the buried oxide film 20 of the support substrate 10 , an impurity such as As or the like is ion implanted at such a high concentration as substantially 1E20 cm−3, the portion being the low electric resistance layer 40 . Still furthermore, the low electric resistance layer 40 extends from the lower portion of the element isolation region 50 to the lower portion of the SOI layer 30 .
Furthermore, on the SOI layer 30 and the element isolation layer 50 , an interlayer insulating film 80 is formed. Still furthermore, a plug 100 that penetrates through each of the interlayer insulating film 80 , the element isolation layer 50 and the buried oxide film 20 , is made of W and reaches down to the surface of the support substrate 10 is formed. Furthermore, the bottom portion of the plug 100 is the adhesion layer 95 made from TiN. That is, the adhesion layer 95 at the bottom portion of the plug 100 comes into contact with the low electric resistance layer 40 .
As explained above, the semiconductor device according to the second embodiment of the invention has, in the neighborhood of the oxide film of the support substrate, a low electric resistance layer that extends from the lower portion of the SOI layer to the lower portion of the element isolation layer. Furthermore, a contact is connected to the low electric resistance layer thereof. When the structure is shown with a circuit diagram, it becomes like FIG. 6 . In the following, an effect of the second embodiment according to the invention will be explained with reference to FIG. 6 .
In FIG. 6 , node N 1 is the plug 100 ; respective nodes N 2 are portions that are at a lower portion of the SOI layer 30 of the low electric resistance layer 40 ; and wiring resistance R is a portion that extends from the plug 100 to the lower portion of the SOI layer 30 of the low electric resistance layer 40 .
When the operation of the transistor 60 is controlled, in some cases, an electrical potential of the low electric resistance layer 40 of a portion that is on an opposite side through the buried oxide film 20 to the transistor 60 is adjusted. At this time, the low electric resistance layer 40 (hereinafter referred to as N 2 ) of the portion, as shown in FIG. 6 , is electrically connected to the plug 100 (hereinafter referred to as N 1 ); accordingly, when a electrical potential of the N 1 is varied, a electrical potential of the N 2 can be adjusted.
When the electrical potential of N 1 is varied, electrical potential difference is generated between the N 1 and N 2 ; accordingly, an electric current flows between the N 1 and N 2 . Owing to the electric current, electric charges move from the N 1 to the N 2 , finally the N 1 and N 2 become the same in the electrical potential. This is the mechanism by which the electrical potential of N 2 is adjusted. However, at this time, there is the wiring resistance R between the N 1 and N 2 ; accordingly, when the electrical potential difference between the N 1 and N 2 is determined, according to the Ohm's law, a magnitude of the electric current is also determined. The electric current becomes larger as a value of the wiring resistance R becomes smaller. Accordingly, the smaller the wiring resistance R is, the larger is an electric current that can be flowed between the N 1 and N 2 . Furthermore, an electric current denotes an amount of electric charges that flow in a unit time. Accordingly, since as the electric current becomes larger, the electric charges move more rapidly, the electrical potential of the N 2 can be swiftly changed with respect to the change of electrical potential of N 1 .
In the second embodiment of the invention, since the low electric resistance layer extends from the plug to the lower portion of the SOI layer, a larger electric current can be flowed from the plug to the support substrate at the lower portion of the SOI layer. Accordingly, when the electrical potential of the support substrate at the lower portion of the SOI layer is manipulated in order to control the operation of the transistor formed in the element formation region in the SOI layer, the electrical charges can be rapidly supplied to the support substrate at the lower portion of the SOI layer. Accordingly, the electrical potential of the support substrate at the lower portion of the SOI layer can be rapidly manipulated.
As mentioned above, in the method of fabricating the semiconductor device described in the first embodiment according to the invention, irrespective of the aspect ratio of the contact hole, the impurity can reach down to the support substrate. Furthermore, since the ion implantation of the impurity is applied to the support substrate of a completed SOI wafer, there is no chance that owing to heat during the lamination, the impurity that is ion implanted to the support substrate diffuses to increase the electric resistance of a region where the impurity is ion implanted, namely, the low electric resistance layer. On the other hand, the semiconductor device according to the second embodiment of the invention allows rapidly manipulating the electric potential of the support substrate at the lower portion of the element formation region.
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The present invention relates to a method of fabricating a semiconductor device that allows assuredly ion implanting an impurity to a support substrate and a semiconductor device that can rapidly operate an electric potential of the support substrate. According to the present fabricating method, an impurity is ion implanted over an entire surface of a support substrate under a buried oxide film; accordingly, the impurity can be delivered to other than a bottom portion of a contact hole. Accordingly, a low electric resistance layer extending from a lower portion of an element formation region to a lower portion of an element isolation region can be formed. As a result, an electric current can be flowed much from a contact to the support substrate at the lower portion of the element formation region. Accordingly, electric charges can be rapidly supplied to the support substrate at the lower portion of the element formation region, resulting in rapid operation of an electric potential of the support substrate at the lower portion of the element formation region.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority of U.S. Provisional Application No. 61/972,897 filed Mar. 31, 2014, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a flexible automation cell adapted to load blanks for production parts into an adjacent machining center for the performance of a primary operation, to unload the parts after performance of the primary operation, and to perform secondary operations, including checking the results of the primary operation on the unloaded part, and to a roll check operation for measuring gear run-out.
BACKGROUND OF THE INVENTION
Automated machining centers, often employing numerically controlled milling machines, lathes, or similar specialty machine tools such as gear grinding machines and the like, have come into widespread use to perform primary operations on workpieces. The parts produced by these machining centers often require secondary operations, such as the inspection of the parts for proper completion of the primary operation, cleaning the part by washing or the like, or the performance of additional machining operations. In present practice, these primarily machined parts are unloaded from the machining center and delivered to a separated machine for the performance of the necessary secondary operations. Often several secondary operations must each be performed in different machines and the part must further be transported between these machines. This multistage processing is often time consuming, requires substantial manual labor, and is wasteful of shop space.
SUMMARY OF THE INVENTION
To eliminate these inefficiencies, the present invention is directed toward an automation cell adapted to be located immediately adjacent to a machining center and incorporating robotic means for loading the machining center with blanks to be operated on by performance of one or more primary operations, and the ability to remove the primary machined parts to the automation cell for inspection and the performance of one or more secondary operations. The output of the automation cell constitutes parts which have been primarily machined, passed inspection, and had some or all of the necessary secondary operations performed in the cell. This arrangement greatly improves the speed of producing finished parts; eliminates the labor necessary to load, unload, and transport the parts between machines; and conserves shop floor space.
While a preferred embodiment of the invention employing a novel run-out roll inspection operation performed in the automation cell is disclosed, the broader aspects of the present invention are applicable to any part requiring primary operations to be performed in a machining center and secondary operations to be performed after the primary machining. The invention is not limited to the common numerically controlled milling machines or lathes but is applicable to any machining sequence amenable to a primary operation being performed in one machine and secondary operations being performed in one or more separated machines.
In the preferred embodiment of the invention the machining center constitutes a gear grinder and the associated automation cell inspects primarily machined parts that are received from the gear grinder for assurance that their run-out is within specified limits in a novel manner. The automation cell may also laser mark the parts and wash them to remove any residual materials from the primary machining operation. Unmachined blanks and the resulting primarily machined parts are transferred between the automation cell and the machining center by a robot. In the preferred embodiment of the invention the robot comprises a six axis electrically servo driven robot with high speed and precision. The robotic arm is equipped with a “dual gripper” tooling configuration that uses servo controlled gripper mechanisms to clamp and unclamp the parts. The servo controlled gripper mechanism also provides the ability to measure the part diameter to determine that the proper part style has been loaded into the machining center from the automation cell and that the part matches the current part selected for manufacturing.
The dual gripper tooling configuration allows the robot to perform a part exchange wherein, in a single cycle, the part blank is loaded from the automation cell into the machining center and a primarily machined part is removed from the machining center to the automation cell for the performance of secondary operations, preferably including inspection.
The automation cell of the preferred embodiment employs a part wash and spinoff station used to remove material fines and excess cutting fluid from the machined parts. It also incorporates a laser marking which will mark the part with an assigned 2D code or serial number that can be used for traceability of the workpiece. The cell contains a controller that can record and store data for each gear that is logged to the unique serial number.
In the preferred embodiment of the invention the parts being operated on are ground gears and the inspection performed in the automation cell constitutes a novel process for checking gear run-out from center line during meshed rotation of the machined gear against a qualified master part. Broadly, the machined production gear is loaded into a powered spindle for rotation and the master gear is supported for rotation on a slide capable of movement toward and away from the production gear along an axis which is essentially normal to the rotational axis of the production gear. The slide rotatably supports the master gear and is preferably powered pneumatically to move the master gear into meshed engagement with the rotating production gear. As the two rotate, the slide support is forced laterally to the rotational axis against the fluid driver, as a result of gear run-out from center line. This motion is sensed and a signal from the sensor is provided to a controller that will determine whether the maximum run-out value exceeds an acceptable limit. If it does exceed this limit, the gear will be tagged as a reject.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objectives, advantages, and applications of the present invention will be made apparent by the following detailed description of a preferred embodiment of the invention. The description makes reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a commercially available gear grinding machine and an adjacent automation cell embodying the present invention;
FIG. 2 is a plan view of the automation cell forming part of the present invention;
FIG. 3A is a perspective view of the preferred embodiment of the automation cell of the present invention from the upper corner of the front, with the side panels removed;
FIG. 3B is a perspective view of the automation cell from the upper rear, with the side panels removed;
FIG. 4 is a plan view of the roll checking mechanism of the present invention;
FIG. 5 is an elevation view of the roll checking mechanism of FIG. 4 ;
FIG. 6 is an end view of the roll checking mechanism of the present invention;
FIG. 7 is a perspective view from the upper side of the roll checking mechanism of the present invention; and
FIG. 8 is a detail view of the dual gripper mechanism support on the free end of the robotic arm forming part of the automation cell.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated in FIG. 1 , the automation cell 10 of the present invention coordinates and is disposed adjacent to a machining center 12 that performs primary operations on workpieces. Typical machining centers constitute numerically controlled milling machines or lathes or other specialty machines such as the gear grinder employed in the preferred embodiment of the present invention. The machining centers could constitute “tool changing” machine centers employing a variety of cutters that can be alternatively employed by the machine such as tool changing milling machines.
As has been noted, the preferred embodiment of the present invention relates, among other things, to the automation cell 10 for performing secondary operations on a gear after a gear blank has been initially ground in a modular gear grinding machine 12 such as is illustrated in FIG. 1 . These commercially available machines may be equipped with one or more work spindles which may be automatically moved into an easily accessible loading and unloading position. The illustrated machine is manufactured by Reishauer.
The automation cell 10 is generally indicated in the plan view of FIG. 2 and in the two perspective views of FIGS. 3A and 3B . The cell is enclosed by a rectangular framework 14 . The framework supports side and top panels which enclose the automation cell 10 but which are not shown in FIGS. 2, 3A, and 3B for purposes of illustration. The panels are typically formed of plastic and may be translucent.
The frame 14 supports a horizontal table 16 . The table supports a pair of trays 18 and 20 . The tray 18 is used to receive incoming parts, that is blanks that have not been primarily machined. These may be loaded either manually or automatically through two access doors 22 in the side panels. The tray 20 is for outgoing parts, that is parts that have been primarily machined in the machining center 12 , returned to the automation cell 10 , undergone the secondary operations provided by the automation cell, and passed inspection.
In its central section the table 16 supports a robot 24 which can move incoming parts from the tray 18 into the machining center 12 , can retrieve the primarily machined parts, move them between the secondary operation devices supported in the automation cell 10 , and place the completed parts, those which passed the inspection, in the outgoing part tray 20 . Completed parts which do not pass the inspection provided by the automation cell 10 are placed by the robot 24 into a reject part bin 26 .
The robot 24 is programmable and preferably constitutes a six axis of freedom robot.
The robot 24 is programmed to place certain sample parts which have been completed and passed inspection into an SPC (statistical process control) post assembly 28 . For example, every fiftieth part which has passed inspection may be moved into the post 28 where it may be removed and externally inspected to ensure that the automation cell is meeting the required inspection standard.
The parts removed from the machining center 12 by the robot 24 are first loaded into a roll check assembly 30 . This assembly, which will later be explained in more detail, is a novel unit for checking gear run-out from center line during rotation of the machined gear against a qualified master part. This run-out measurement is compared to a stored maximum value. The machined parts that do not meet this roll-out specification are loaded by the robot into the reject part bin 26 .
The automation cell 10 also has a laser marker 32 for the completed parts. This preferably constitutes a fiber type laser used for part marking. The laser will mark a part with an assigned 2D code/serial number that can be used for traceability of the workpiece. The cell can record and store data for each gear that is logged to the unique serial number. Possible data points for collection could be: 1) manufacturing machine number; 2) manufacturing machine spindle number (in the case of multi spindle machines); 3) date and time of manufacture; 4) roll check inspection results. The laser marker 32 further comprises a shuttle used to fix the gear and transport it under the laser marker in a sealed enclosure for marking.
The automation cell 10 further comprises a part washer 36 to wash the parts and rotate them to spin off moisture and the like, used to remove material fines and excess cutting fluid from the machined parts.
As has been noted, the robot 24 arm 38 has the capability of gripping two parts at a time in order to load one new part and remove one completed part from the gear grinder or other serviced machine 12 . The detail of the arm end is illustrated in FIG. 8 . Each of the grippers, labeled A and B, comprises a pair of concave sections facing one another, one of which can be moved toward and away from the other under suitable fluid power. The arm also includes gauging equipment which measures the closed positions of the movable gripper section against the part to provide a measurement of the part diameter and control the amount of force applied during the gripping process. The diameter measurement may be used to determine that the proper part style has been loaded in the incoming part tray, and that the part matches the current part selected for manufacturing.
A preferred embodiment of the roll check assembly 30 is illustrated in FIGS. 4-7 . The roll check assembly is supported on a base plate 50 . A pair of linear bearing rolls 52 extend parallel to one another on the base and support a master gear slide table 54 . The master gear slide table 54 has a spindle 56 for supporting a master gear 66 , extending from its upward surface. A gear for inspection 58 is supported on an ID clamp on a second spindle 60 . The spindle 60 is located between the linear rolls 52 . A pneumatic cylinder 64 with adjustable pressure control drives the slide table 54 toward the spindle 60 to bring the master gear 66 into mesh with the machined gear 58 . In operation, the motor 70 rotates the machined gear 58 as well as the master gear 66 which is in mesh with the machined gear 58 . Any deviation in roll-out from the center line in the machined gear will force the master gear slide table 54 to move away from the center line of the machined gear 58 . An LVDT 70 , best seen in FIG. 4 , senses the position of the slide table and feeds an amplified signal in the millivolt or milliamp range to a processor that translates these signals into a linear position. These signals are stored and compared with a stored value for maximum roll-out to segregate the proper machined gears from the improper gears. By adjusting the pressure control on the cylinder 64 , the slide 54 can be accurately followed by movements of the shaft of the cylinder 64 .
In alternative embodiments of the invention the master gear could be powered into rotation rather than the machined gear.
The sequence of operation of the roll check device is as follows:
1. Operator installs the appropriate master gear on the spindle 56 for the selected production part. 2. Operator installs the appropriate machined gear ID clamp mandrel on the spindle 60 for the selected production part. 3. The robot 24 places a machined gear onto the driven spindle 60 . 4. The driven spindle ID clamp will actuate, clamping the part on the ID (internal diameter). 5. The slide table 54 then is actuated forward by the pneumatic cylinder 64 to engage the machined gear with the master gear. 6. The machined gear then starts to rotate. During initial rotation, the LVDT 70 is monitoring the linear position of the slide table to first ensure the production and master gears have meshed. Once the mesh is realized, the production gear will now monitor the rotation to ensure 1.5 revolutions of the production piece while the LVDT is monitoring the slide table position for gear run-out. 7. Once the inspection cycle is complete, the slide table retracts back to the load/unload position and the driven spindle unclamps the ID part clamp of the production piece. 8. Now the cycle is complete and the material handling device is clear to remove the machined gear and load the next one, re-starting the cycle again at step 3.
The sequence of operation of the entire system is as follows:
1. Operator loads a full tray of “Green” part blanks in the incoming part tray 18 , and an empty tray 20 at the outgoing part tray position. 2. Operator closed the access door and presses a start button. 3. The robot 24 travels to the incoming tray position and removes a green part with gripper A. 4. The robot then travels to the grinding machine and removes a finished part with gripper B, and places a green part with gripper A and moves out clear of the machine (at this point the machine starts its cycle). 5. The robot travels to the part wash position 36 and removes a finished/washed part with gripper A, and places the finished/dirty part in the washer with gripper B and moves up clear of the washer (at this point the washer starts its cycle). 6. The robot travels to the roll checker 30 and removes a full inspected part from the checker fixture with gripper B, and places the cleaned finished part in the checker fixture with gripper A and moves clear of the roll checker (at this point the roll checker starts its cycle). 7a. The robot 24 travels to the laser marker shuttle 34 and removes a marked part with gripper A, and places the inspected part in the shuttle fixture with gripper B and moves up clear of the shuttle fixture (at this point the shuttle fixture moves into the laser position for marking the part). 7b. If the inspected part does not pass the roll check, the robot will move to the reject bin and deposit the part. 8. The robot travels to the outgoing tray position 20 and places the machined, washed, inspected and laser marked part into the outgoing part tray. 9. Cycle now starts over at sequence number 3.
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An automation cell incorporating elements for performing secondary operations on a machined part is adapted to be disposed adjacent to a machining center for performing the primary operations on the part. The cell incorporates a robotic arm capable of being moved into position with respect to the machining center so as to load machined parts into the machining center and unload primarily machined parts for the performance of secondary operations in the cell. In a preferred embodiment the automation cell performs roll check operations on the primarily machined gear by bringing it into meshed engagement with a master gear and rotating the meshed gears and employing a sensor to monitor the roll-out of the machined gear.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of prior application Ser. No. 09/594,585, filed Jun. 15, 2000.
FIELD OF INVENTION
This invention relates to compounds and methods that reduce or control levels of cholesterol and triglycerides and their oxidation to lipid peroxidases, thus preferably inhibiting or arresting the development of atherosclerosis and restenosis when administered to mammals, including humans.
BACKGROUND OF THE INVENTION
The present invention relates generally to compositions and methods for treating atherosclerosis; more particularly, it relates to methods and compositions for treating or preventing atherosclerosis whereby the many and varied problems associated with the disease can be prevented, arrested, substantially alleviated or cured.
In the United States and Western Europe, cardiovascular disease and its associated maladies, dysfunctions and complications are a principal cause of disability and the chief cause of death. One specific entity significantly contributing to this pathophysiologic process is atherosclerosis, which has been generally recognized as the leading health care problem both with respect to mortality and health care costs. The American Heart Association estimates that 953,110 persons died of cardiovascular diseases in 1997 (41.2 percent of all deaths), more than the number of mortality for cancer (539,377), accidents (95,644) and HIV (16,516) combined. Furthermore, by association calculations, close to a quarter of the US population suffers from one or more forms of cardiovascular disease. American Heart Assoc ., 2000, http://www.americanheart.org/Heart_and_Stroke_A_Z_Guide/cvds.html. The medical costs associated with coronary heart disease are estimated at $95 billion dollars a year. Gonzalez & Kannewurf, 55 (19) American Journal of Health-System Pharmacy S4-7 (Supp. 1, 1998).
Atherosclerosis is a disease characterized by the deposition of fatty substances, primarily cholesterol, and subsequent fibrosis in the inner layer (intima) of an artery, resulting in plaque deposition on the inner surface of the arterial wall and degenerative changes within it. The ubiquitous arterial fatty plaque is the earliest lesion of atherosclerosis and is a grossly flat, lipid-rich atheroma consisting of macrophages (white blood cells) and smooth muscle fibers. The fibrous plaque of the various forms of advanced atherosclerosis has increased intimal smooth muscle cells surrounded by a connective tissue matrix and variable amounts of intracellular and extracellular lipid. At the luminal surface of the artery, a dense fibrous cap of smooth muscle or connective tissue usually covers this plaque or lesion. Beneath the fibrous cap, the lesions are highly cellular consisting of macrophages, other leukocytes and smooth muscle cells. Deep in this cell-rich region may be areas of cholesterol crystals, necrotic debris and calcification.
If allowed to progress, the disease can cause narrowing and obstruction of the lumen of the artery, diminished or occluded blood flow and, consequently, ischemia or infarction of the predominantly affected organ or anatomical part such as the brain, heart, intestine or extremities. The result can be significant loss of function, loss of cellular substance, emergency medical and/or surgical procedures, and significant disability or death. Alternatively, the arterial wall can be severely weakened by the infiltration of the muscular layer with the lipid (cholesterol), inflammatory white blood cells, connective tissue and calcium, resulting in soft and/or brittle areas which can become segmentally dilated (aneurysmal) and rupture or crack leading to organ, limb or even life-threatening hemorrhage.
Once the disease has progressed to the stage of significant persistent symptoms and compromised function, the next treatment step has conventionally been artery bypass grafting to repair and/or replace the damaged artery. While coronary artery bypass has become one of the more common major cardiovascular surgical procedures in the United States, surgery clearly is not the solution to the pathologic process. Moreover, there is a significant risk of morbidity and mortality associated with surgery that many patients are reluctant to accept. Indeed, the autogenous veins or arteries used to bypass the disease-impaired arteries undergo atherosclerosis changes postoperatively generally at a faster rate than the original, affected arteries. The Coronary-Artery Surgery Study (CASS) sponsored by the National Heart, Lung and Blood Institute (NHLBI) concluded that certain subsets of patients do not gain any overall statistical benefit from bypass surgery in comparison to other medical treatments. Carraciolo, 91(9) Circulation 2335-44 (1995).
As an alternative to coronary bypass surgery, certain medications and procedures are used to treat the results of atherosclerosis. These treatments include chelation with ethylene diamine tetra-acetic acid (EDTA) and percutaneous transluminal coronary angioplasty (PTCA). EDTA treatments, however, are still experimental, unproved and potentially as harmful as they are beneficial. PTCA treatments are invasive, of limited application and success and occasionally manifest lethal complications. Highly experimental intra-arterial laser beam plaque vaporization has limited application and requires an open operative approach to affected vessels.
It is now well established that vascular blockage and cardiovascular disorders including myocardial infarction, coronary heart disease, hypertension and hypotension, cerebrovascular disorders including stroke, cerebral thrombosis and memory loss due to stroke; peripheral vascular disease and intestinal infarction are caused by blockage of arteries and arterioles by atherosclerotic plaque. The production of atherosclerotic plaque formation is multi-factorial in its production. Hypercholesterolemia, especially elevated levels of low-density lipoprotein cholesterol (LDL) is an important risk factor for atherosclerosis and arteriosclerosis and associated diseases.
Lipoproteins are spherical particles with the non-polar triglycerides and cholesteryl esters in the hydrophobic core, the polar lipids, phospholipids and free cholesterol on the surface with apolipoproteins. When the amount of cholesterol entering the body increases, the pools of sterol within liver cells expands and the receptors that clear LDL from the blood down-regulate, thus increasing LDL levels in the blood. When cholesterol intake is constant, some long-chain saturated fatty acids further suppress the hepatic LDL receptor whereas several unsaturated fatty acids have the opposite effect. Lipoprotein (a) [Lp (a)] has emerged as a plasma lipoprotein linked to both diseases of the coronary arteries, the carotid and the cerebral arteries. It is structurally related to LDL and possesses one molecule of apolipoprotein B 100 per particle. Macrophages express the scavenger receptor that readily recognizes oxidatively modified Lp (a). Marcovina & Morrisett, 6 Current Opinion In Lipdology 136-145 (1995).
Cholesterol levels below 200 mg/dl are considered “desirable.” A Scandinavian study showed that reduction of cholesterol reduced mortality associated with coronary artery disease (CAD) by 42% over six year period and reduced overall mortality by 30%. Goodman & Gilman's The Pharmacological Basis of Therapeutics (J. Hardman & L. Lipman, 9 th ed. 1996) [Hereinafter “J. Hardman”]. Researchers have shown that a 1-mMol/L increase in triglyceride levels produces a 76% increase in cardiovascular disease risk in women and a 31% increase in men. Austin, 83 (9B) American Journal of Cardiology 13F-16F (1999). Even in patients with established disease, lowering of LDL cholesterol to between 2 and 2.5 mmol/L retards its progression and may even lead to regression. Illingsworth, 41(20) DRUGS 151-160 (1991).
It is recommended that persons with elevated cholesterol concentrations above 240 mg/dL (6.2 mM/L) receive treatment and that those with borderline values between 200-239 mg/dL (5.2 to 6.2 mM/L) be further evaluated according to the presence of risk factors for coronary artery disease including the sex of the patient, post-menopausal status, a low plasma concentration of HDL cholesterol (below 35 mg/dL [0.9 mM/L]), positive family history, smoking, hypertension and diabetes mellitus. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, 269(23) J. Am. Medical A . 3015-3023 (1993). Other factors include obesity, hypertriglyceridemia, sedentary lifestyle, steroid use, β-adrenergic blocking agents, some diuretics and genetic factors. Frohlich & Pritchard, 22 Clinical Biochemistry 417-433 (1989).
By the 1980's, it was recognized that HDL levels could be more important in predicting atherosclerotic disease than LDL and that HDL may prevent the development of CAD. Id. Factors such as smoking, obesity, hypertriglyceridemia, genetic factors and lack of exercise are major causes of reduced serum HDL. HDL cholesterol lipoproteins move excess cholesterol from the extrahepatic organs to the liver for excretion. Dietschy, 65 Am. J. Clinical Nutrition 1581S-9S (1997). There is evidence that virtually every body tissue is capable of at least some cholesterol synthesis from the precursor acetyl-coenzyme A (CoA). Every day, HDL carries back to the liver an amount of cholesterol equal to the amount synthesized and taken up as LDL by all extrahepatic organs except endocrine glands. There is a second LDL transport process that is receptor independent. Id. Removal of free cholesterol from arterial wall cells may be an important mechanism by which HDL plays an anti-atherogenic role. J. Hardman, supra, at 878.
The earliest recognized gross lesion in atherogenesis is the fatty streak, characterized by an accumulation of cells loaded with cholesteryl esters (“foam cells”) just beneath the vascular endothelium. The LDL receptor in the arteries gives rise to foam cells and fatty streaks, the earliest lesion in atherosclerosis, but there is also a receptor-independent mechanism for their formation. This has been demonstrated by the development of lesions rich in macrophage-derived foam cells, even in patients and animals deficient in LDL receptors, and the failure to produce foam cells from normal monocytes and monocyte derived macrophages incubated with LDL. This led researchers to explore the possibility of a post-secretory modification of LDL before it is taken up into foam cells by a new, specific receptor: the “scavenger receptor.” Steinberg, 320(14) New Eng. J. Medicine 915-924 (1989).
Researchers have shown that when LDL was incubated with cultured endothelial cells it underwent a striking series of physical and chemical changes and was taken up by cultured macrophages 10 times more rapidly than native LDL. Id., at 916. At any given level of hypercholesterolemia there is considerable variation in clinical disease. Postsecretory modifications in the structure of lipoproteins appear to effect their atherogenic potential. Steinberg, supra, at 915. It is not only the elevated levels of LDL cholesterol that are important, but also its oxidation that leads to atherosclerosis. For this reason antioxidants are believed to reduce the risk of atherosclerotic disease. Mortensen, 18 Molecular Aspects of Medicine s137-s144, (Supp.1997). Peroxidation of polyunsaturated fatty acids in the LDL. lipids is the common initiating factor of the changes and the cytotoxicity of oxidized LDL has been proven by several research groups and may lead to the denudation of the benign fatty-streak lesion into the atheromatous plaque. Steinberg, supra, at 918.
Researchers believe that the oxidation of LDL within the arterial wall itself is most important. Ocana, 321(17) New Eng. J. Medicine 1196-1197 (1989). Auto-antibodies to MDL-LDL were seen at significantly higher titers in men with atherosclerosis than in normal controls, and in a greater proportion of smokers, those with higher LDL cholesterol, and those with higher serum levels of copper in the case group. Salonen, 339 LANCET 883-887 (1992).
Researchers also have studied the effects of incubation of LDL with macrophages and found that in that environment LDL is oxidized and recognized and taken up by the acetyl LDL or scavenger receptor in the same cell. Alpha-tocopherol, butylated hydroxytoluene (BHT) and Probucol block this process. Parthasarathy, 6(5) Arteriosclerosis 505-10 (1986). Treatment with Probucol, a potent anti-oxidant, significantly lowered the rate of development of fatty streak lesions in hyperlipidemic rabbits, although the plasma cholesterol level was not lower than in lovastatin-treated animals. Carew, Schwenke & Steinberg, 84 Proc. Nat'l Acad. Sci. USA 7725-7729 (1987). Similar results have been demonstrated in cultures of LDL with endothelial cells. Steinbrecher, 81 Proc. Nat'l Acad. Sci . 3883-3887 (1984). Monocytes and neutrophils, when incubated with LDL, oxidize LDL and render it toxic. Cathcart, Morel & Chisolm, 38 J. Leukocyte Biology 341-350 (1985).
Vitamin E, a potent antioxidant, has been shown to reduce the extent of atherosclerosis in several animal models and studies have shown that Vitamin E can be protective against the disease. Pryor 28(1) Free Radical Biology & Medicine 141-64 (2000). The development of the fatty streak lesion may be based upon two factors: the presence of elevated plasma LDL and its oxidative modification within the artery wall. Steinberg, supra, at 919. LDL particles in whole plasma contain the antioxidant compounds vitamin E and β-carotenes and the plasma itself contains antioxidants that protect the LDL for a relatively short time. Under pro-oxidant conditions, the vitamin E and β-carotene are destroyed before the fatty acids undergo peroxidation. Id., at 921. It is likely that decreases in vitamin E and beta-carotene are early events reflecting the initial stages of lipid peroxidation. Witztum & Steinberg, 88(6) J. Clinical Investigation 1785-1792 (1991).
Common medications used to lower plasma cholesterol levels include Atromid-S®. (clofibrate), Choloxin® (dextrothyroxine sodium), Colestid®, (colestipol hydrochloride), Lopid®. (gemfibrozil), Lorelco®, (probucol), Nicolar® (Niacin/nicotinic acid) and Questran ® (Cholestyramine resin). These drugs and their associated treatments, however, generally are directed only at the cause, and not the result, of atherosclerosis and have not been shown to be effective in reversing the plaque deposition and degenerative changes in the arterial walls. These phannacological agents also have many other shortcomings such as, for example, adverse side effects (hypertension, cardiac arrhythmias, gastrointestinal disturbances, headache, hypersensitivity, etc . . . ), contraindications (heart, liver or kidney disease, pregnancy, etc . . . ), requirement for lifelong conscientious administration, difficulty in maintaining consistent patient compliance, variable reliability and high cost.
Other therapies have been used to lower cholesterol levels. These include: dietary changes, Bruce, 19(1) Journal of the American College of Nutrition 61-7 (2000); fiber and psyllium, Knopp, 17(1) American Journal of Preventive Medicine 18-23 (1999), Burton & Mannien, 668 Medica Scandinavica 9104 (Supp. 1982); Vitamins C, E, and carotenoids, Anonymous 20(1) European Heart Journal 725-41 (1999), Azen, 94(10) Circulation 2369-72 (1996), Hodis, 273(23) J. Am. Medical A 1849-54 (1995), Kothari 28(1) Acta Biologica Academiae Scientiarum Hungaricae 111-4 (1977); L-carnitine, Stefanutti, 149(2) Clinica Terapeutica 115-9 (1998), Elisaf, 18(5) Am. J. Nephrology 416-21 (1998); fatty acids, Leng, 4(4) Vascular Medicine 219-26 (1999); fatty acids eicosapentanoic acid (fish oil) and garlic, Morcos, 89(10) J. Nat. Medical A . 673-8 (1997); beta glucan, U.S. Pat. No. 6,020,324 to Jamas, et.al.; and, arnino acids, U.S. Pat. No. 5,248,688 to Dudrick.
Bile acid-binding resins, such as cholestyramine, promote bile acid excretion and were shown to produce a 20% decrease in LDL. This treatment, however, lead to a compensatory increase in the number of hepatic LDL receptors and induction of HMG-CoA Reductase activity, which may bind other negatively charged anions and hence decrease the absorption of therapeutic drugs. J. Hardman, supra, at 890-1.
U.S. Pat. No. 6,020,383, to Stone, states that a substance used as an antioxidant in food and in cosmetics and to inhibit polymerization of polyesters, tert-butylhydroquinone (“TBHQ”), was shown to unexpectedly reduce blood cholesterol and triglycerides in rats. The inventor further discusses the use of TBHQ in combination with other natural oxidants including vitamins C and E, tocopherols, and Coenzyme Q 10 .
The HMG-CoA Reductase inhibitors have been used with some success in reducing blood levels of LDL cholesterol and raising HDL levels. Cholesterol is produced via the mevalonic acid pathway. Reducing the formation of mevalonic acid, a precursor to cholesterol, leads to a corresponding decrease in hepatic cholesterol biosynthesis with a reduction in the cellular pool of cholesterol. There is a compensatory increase in the number of high affinity LDL receptors expressed on the cell surface, stimulating an increase in catabolism of VLDL remnants and LDL, and possibly a reduced hepatic synthesis. Illingsworth, supra.
The first specific competitive inhibitors of HMG CoA Reductase that were tested in human subjects were mevastatin (isolated from cultures of Penicillium citrinum ) and lovastatin (isolated from cultures of Aspergillis terreus and Monascus purpurea ). Endo, 32(8) J. Antibiotics 852-4 (1979). A related compound, Monacolin M, was isolated from culture of Monascus ruber in 1986. Endo, Komagata & Shimae, 39(12) J. Antibiotics 1670-3, (1986). Mevastatin, however, was withdrawn from clinical use in Japan because of rumored changes in intestinal morphology in dogs, although similar effects were not seen with lovastatin. Illingsworth, supra, at 152. The efficacy of the other HMG-Reductase inhibitors is documented. Lovastatin was shown to decrease levels of VLDL by 53% and LDL by 32.4%, and simvastatin was shown to decrease cholesterol by 34% and triglycerides by 39%, yet the concentration of Lp (a) rose in some patients. Id., at 155. Side effects include headaches, transient changes in bowel habits, nausea, insomnia, and less commonly muscle tenderness and increased plasma creatine kinase. Illingsworth, supra, at 157.
Pravastatin has also been combined with nicotinic acid (niacin) to increase reductions in serum cholesterol. Davignon, 73 Preventive Cardiology 339-345, (1994). Lovastatin was shown to be safe and effective in reducing total cholesterol and LDL while raising HDL, but side effects included increased liver transaminase levels (in 2%), myopathy with a creatine kinase greater than 10 times normal (in 0.5% of subjects) and required discontinuation in 9% of those treated. The authors confirmed the need to monitor liver function tests every 4-6 weeks in patients on lovastatin therapy. Dujovne, 91 Am. J. Medicine 25S-30S (Supp. 1B, 1991).
A serious shortcoming of the HMG CoA Reductase inhibitors, including the more natural Monascus, is the unavoidable depletion of Coenzyme Q 10 . This is because Coenzyme Q 10 is synthesized from acetyl-CoA through mevalonate and isopentenylpyrophophate, as is cholesterol. By inhibiting the production of mevalonate to reduce cholesterol, it follows that there is less to form Coenzyme Q 10 as well. Mortensen, supra.
SUMMARY OF THE INVENTION
The inventor has now discovered that appreciating the multi-factorial genesis of cholesterol elevation and affecting several phases of cholesterol production simultaneously with a composition of natural substances is a way to effectively control cholesterol levels. A method of altering the concentration of the cholesterol constituents in the blood of a human to reduce the risk of atherosclerosis and vascular disease is provided. A composition comprising red yeast rice, Coenzyme Q 10 , and mixed tocopherols, with or without one or more selected from the group consisting of selenium, inositol hexanicotinate or chromium, is administered to a human in an amount effective to reduce or control blood cholesterol, to increase the concentration of HDL-cholesterol and/or to decrease the concentration of LDL-cholesterol in the blood of the human.
In accordance with the present invention, methods and compositions are provided for use in treating atherosclerosis and its associated diseases including cardiovascular disorders, cerebrovascular disorders, peripheral vascular disorders, and intestinal vascular disorders. The methods and compositions of the present invention are particularly advantageous in that they may be used to both significantly lower plasma cholesterol levels and substantially arrest, reverse and/or cure the arterial plaque deposition and degenerative vascular wall changes associated with atherosclerosis.
The compositions of the present invention can be administered prophylactically, so as to inhibit atherogenesis or restenosis, or therapeutically after atherogenesis has been initiated. Thus, for example, a patient who is to undergo balloon angioplasty can have a regimen of the composition administered substantially prior to the balloon angioplasty, preferably at least about a week or substantially longer. Alternatively, in a patient where atherogenesis is suspected, the administration the composition can begin at any time. Administration may be accomplished in any manner known to those skilled in the art, including peroral, liposomal, inhalation, sublingual, rectal (e.g., suppositories), or through an oral spray or dermal patch.
Methods are provided for modulating the production of LDL-cholesterol through inhibition of HMG-Reductase, enhancing levels of HDL-cholesterol, replacing the resulting deficiency of Coenzyme Q 10 , supplying anti-oxidants mixed tocopherols with or without selenium to reduce the oxidation of LDL into lipid peroxidases, and normalizing carbohydrate metabolism through the administration of chromium and/or inositol hexanicotinate. As a prophylactic or treatment for atherosclerotic susceptible hosts, the composition is chronically administered at an effective dosage. For restenosis, the agent may be administered for a limited period since this pathological process generally abates 3-6 months after the vascular injury (i.e., angioplasty or atherectomy).
In one embodiment of the invention, the composition is administered to a human in one or more tablets as a dietary supplement.
In another embodiment of the invention, the composition is administered to a human in a pharmaceutical composition.
In another aspect, the invention is a method of altering the concentration of cholesterol constituents in the blood of a human, to preferably reduce the risk of atherosclerosis and vascular disease, where the composition is administered to a human in an amount effective to increase the concentration of HDL-cholesterol in the blood of the human. Reducing cholesterol levels with the administration of this composition can also prevent other plaque formation and other types of atherosclerotic disease such as the cereberovascular complications of carotid artery plaques, peripheral vascular disease and claudication, and intestinal vascular blockage and infarction.
DETAILED DESCRIPTION OF THE INVENTION
Hyperlipidemia relates to plasma cholesterol and triglyceride levels that exceed “normal” —arbitrarily defined as the 95 th percentile. But it is now clear that “ideal” or “optimal” levels are far below the normal levels of the population. A large proportion of United States adults have concentrations above the optimal range and should be considered to have hyperlipoproteinemia. J. Hardman, supra, at 875.
In a preferred embodiment of the invention, a composition is administered that simultaneously affects several different mechanisms in the production of atherosclerosis, including the levels of LDL and HDL cholesterol, through inhibiting HMG-CoA Reductase, correcting any consequent depletion of Coenzyme Q 10 , and inhibiting the oxidation of LDL into lipid peroxidases. In another embodiment, chromium or inositol hexanicotinate, or both, is added for control of insulin and lipid metabolism and additional control or reduction of cholesterol levels.
One theory is that both the presence of elevated plasma LDL and its oxidative modification within the artery wall is required to produce atherosclerosis. Steinberg, supra. Indeed, then the use of an appropriate antioxidant in vivo should decrease the rate at which LDL is taken up by macrophage foam cells and slow the development of the fatty streak lesion. This phenomena has been demonstrated in receptor deficient rabbits treated with Probucol as an antioxidant. Parthasarathy, supra.
Red yeast is a mixture of several species of Monascus fungi; the predominant one is Monascus purpureus . Monascus was first described in 1884. Van Tieghem, 31 Bull. Soc'y Botany France 226 (1884). Monascus has been used for centuries as in wine fermentation and as a food colorant and preservative. See http://www.allok.coin/ehistorie.htm. A traditional Chinese product used to make rice wine and as a preservative is based on rice that has been fermented with Monascus purpureus . Heber, 69 Am. J Clinical Nutrition 231-236 (1999), citing Stuart, Chinese Materia Medica—Vegetable Kingdom ( 1979). This product also has a tradition of being useful in “improving the blood circulation.” D. Bensky & R. Barolet, Chinese Herbal Medicine: Materia Medica (Revised Ed. 1993).
The medical applications of red yeast were described in the ancient Chinese pharmacopoeia, Pen Ts'ao Kang Mu, published during the Ming dynasty (1368-1644). It describes red yeast as useful for treating indigestion, diarrhea, and improving the health of the spleen, stomach, and circulation. In Ancient China, Monascus was called “Hongqu” and was said to have the ability to cure stomach and spleen, to strengthen the blood, and the principle to preserve and endorse the common Qi interdependent. Ben Cao Gang Mu Von Li Shi - Zen, Book of Medicinal Herbs (1590).
More recently, researchers discovered that a strain of Monascus yeast used in the production of red yeast rice naturally produced a substance that inhibits cholesterol synthesis called Monacolin K (lovastatin), along with a group of 8 Monacolin-related substances that are HMG-CoA Reductase inhibitors. Endo, supra. Experiments in rabbits revealed that one extract, Xuezhikang, lowered cholesterol levels by 44% and 59% at doses of 0.4 and 0.8 mg/kg, respectively. Id., see also Li, 18(1) Nutrition Research 71-81 (1998). These doses correspond to human doses of 24 mg and 48 mg (for a 60-kg person). Chinese red yeast rice costs only $20-30 per month at such doses, compared to the average cost of $187/month for a cholesterol-lowering drug. Id.
The effects of Monascus purpureus rice in 324 patients were compared with the effects of another Chinese herbal medicine, Jiaogulan (gynostemma pentaphylla) on serum cholesterol. Wang, 58(12) Current Therapeutic Research 964-978 (1997). Eligible patients were recruited if their serum total cholesterol (TC) was 240 mg/DL (5.95 mmol/L) or higher, LDL-cholesterol was 130 mg/dL (3.41 mmol/L), or triglycerides (TG) were 200-400 mg/dL (2.26-4.52 mmol/L). In addition, HDL-cholesterol was 40 mg/dL (1.04 mmol/L) or less for men or 45 mg/dL (1.16 mmol/L) for women. After 8 weeks, total cholesterol decreased by 34.5% (P<0.001) in treated patients while the positive controls had only an 8.3% decrease. Those patients with pretreatment cholesterol over 300 mg/dL had a greater reduction than did those whose cholesterol prior to treatment was below 240 mg/dL. And while the increase in HDL cholesterol was minor for those with pre-treatment levels >45 mg/dL, significant increases were observed in those with pretreatment HDL of 35-45 mg/dL (16%) and less than 35 mg/dL (25.1%).
Coenzyme Q 10 (Ubiquinone) is a naturally occurring substance that plays a central role in oxidative respiration as a catalyst and has a separate direct membrane stabilizing effect. In man, vitamin E, beta-carotene, and Coenzyme Q 10 all appear to be endogenous antioxidants in LDL. Epidemiologic data suggest a negative correlation between coronary disease and levels of vitamin E. Witztum & Steinberg, supra. It is also an antioxidant and free radical scavenger, and protects ischemic tissue from the damage that occurs when blood flow is restored (reperfusion damage). In studies of cardiac patients, deficiencies of the enzyme were found in 75% of 132 biopsy specimens of heart tissues, and 20% of 406 blood samples. Studies performed by several different groups of researchers have shown that supplementation with Coenzyme Q 10 improves the signs and symptoms of CAD at doses of 1.5 mg/kg per day (90 mg in a 60 kg person), 150 mg/day and 600 mg/day. Greenberg & Frishman, 30 J. Clinical Pharmacology 596-608 (1990) at p. 599. Earlier clinical studies in Japan used a dose of 5 mg, and later a dose range of 25-100 mg. Folkers, el al., 2 J. Molecular Medicine 431-460 (1977).
Coenzyme Q 10 and alpha-tocopherol in the LDL cholesterol are depleted faster on lovastatin therapy during peroxidative insult. The finding was associated with a shortened lag time of conjugated diene formation suggesting diminished resistance of LDL particles to the early phase of oxidative stress. A crossover study was conducted to investigate the effects of supplementation with 180 mg per day Ubiquinone (Coenzyme Q 10 ). There were no differences in the measurements for cholesterol, LDL, HDL, the LDL/HDL ratio, triglycerides, or apolipoprotein levels between treatment arms. But in the oxidative studies, the total depletion time of LDL Coenzyme Q 10 was 49.6% longer on lovastatin but was comparable to pre-treatment levels with supplementation. The authors concluded that the improvement was scarce and its clinical relevance remained open. Palomaki, 39 J. Lipid Research 1430-1437 (1998). In men with familial combined hyperlipidemia, LDL was more prone to oxidation and the Coenzyme Q 10 in the LDL was more predominantly in a reduced state, suggesting the Coenzyme Q 10 plays an important role in protecting LDL from in vivo oxidation. de Rijke, 17(11) Arteriosclerosis, Thrombosis, And Vascular Biology 127-133 (1997). This was studied by comparing patients treated with 20-mg simvastatin per day with or without supplementation with Coenzyme Q 10 at 100 mg per day. In both groups, both total cholesterol and LDL cholesterol declined and results were highly statistically significant. But levels of Coenzyme Q 10 , which started out similar, decreased in the group treated with simvastatin alone, yet increased in the group that was supplemented. Bargossi, 15 Molecular Aspects Of Medicine s187-s193 (Supp. 1994).
Minimally oxidized LDL is believed to be involved in the early stages of atherosclerosis. In several studies of the HGM-CoA Reductase induced Coenzyme Q 10 deficiency, supplementation with coenzyme Q 10 at 100 mg to 180 mg was shown to correct the depletion of the enzyme within the LDL particle. Id. Supplementation with Coenzyme Q 10 , 100 mg per day for 30 days resulted in increased Coenzyme Q 10 levels in all three LDL subfractions (P<0.01) in each of the 10 subjects studied. Small increases in vitamin E were observed, as well as a significant decrease in hydroperoxide levels in the LDL 3 subfraction, which is commonly elevated in patients at high risk for coronary artery disease. Alleva, 92 Proc. Nat'l Acad. Sci . 9388-9391 (1995).
In an open label, eight-year study, 424 patients with various forms of cardiovascular disease added Coenzyme Q 10 , 75 mg to 600 mg/day, to their diets. Improvements in myocardial function (58%) and decreased dependency on drugs (43%) were noted. Langsjoen, 15 Molecular Aspects Of Medicine s 165-s175 (Supp. 1994).
Several prospective studies suggest an inverse association between dietary intake or plasma concentrations of antioxidants and CVD. In a cross-cultural study of 16 European populations, the strongest inverse correlation in this study was observed between ischemic heart disease and plasma concentration of vitamin E, a well-established anti-oxidant. Meydani, 345(8943) Lancet 170-175 (1995). However, two earlier studies in Finland and the Netherlands reviewed by Meydani in 1995 did not find an association between serum vitamin E and subsequent CVD mortality. In men, a borderline significant association was found for dietary intake of vitamin E alone, but it was much stronger for vitamin E supplement users consuming above 100 IU vitamin E daily for at least 2 years. Id.
In their review of published studies, Jha et.al, reported, inter alia, the results of the U.S. Nurses'Health Study. This study followed 87,000 female nurses for an average of 8 years. About 13% of women regularly used vitamin E supplements. These women, after adjustment for age, smoking, alcohol use, menopausal status, hormone use, exercise, aspirin use, hypertension, cholesterol intake, diabetes, caloric intake, and vitamin C and beta-carotene intake, had a statistically significant reduction in relative risk of 31% (95% confidence limit, 3%, to 51 %) for non-fatal myocardial infarction and death from cardiovascular disease in comparison with women who did not use the supplements. The absolute risk reduction was 3.4 women per 10,000 woman-years (a woman-year is one woman followed for one year) of follow-up (8.5 compared with 5.2 per 10,000 woman-years of follow-up). Jha, el al., 123(11) Annals Of Internal Medicine 860-872 (1995).
Vitamin E is a mixture of tocopherols. D-alpha-tocopherol has the highest biological activity and is the most widely available form of vitamin E in food. The other isomers (beta, gamma, and delta) are less biologically active than d-alpha-tocopherol. The commercially available synthetic forms of vitamin E comprise an approximately equal mixture of eight stereoisomeric forms of alpha-tocopherol. For practical purposes, 1 international unit (IU) of vitamin E is referred to as 1 mg of the synthetic form, racemic alpha-tocopheryl acetate, and the natural form of d-alpha-tocopherol has a biopotency of vitamin E equal to 1.49 IU. Vegetables and seed oils including soybean, safflower and corn, sunflower seeds, nuts, whole grains, and wheat germ are the main sources of the tocopherols. Meydani, supra.
Researches have observed a relation between deficient selenium (an antioxidant) and an excess risk of acute myocardial infarction as well as death from CHD and CVD in Eastern Finland. Low serum selenium levels and lipid peroxidation in vivo are associated with accelerated progression of carotid atherosclerosis in Eastern Finnish men. In a 1994 study, Salonen reported that a subject's hair mercury content correlated most strongly of all cardiovascular risk factors. Mercury forms an insoluble complex with selenium (mercury selenide), thus binding selenium in an inactive form that cannot serve as a cofactor for glutathione peroxidase, an important scavenger of peroxide s and lipid peroxides. Salonen, 91(3) Circulation 645-655 (1995). But another study based on 251 subjects who had infarctions and an equal number of healthy controls matched by age, smoking status, and time from randomization, showed no statistical association between plasma selenium and myocardial infarction. Salvini, 76(17) Am. J. Cardiology 1218-1221 (1995).
Deficiency of chromium, a trace element, has been associated with lipid abnormalities and an increased risk of atherosclerotic disease. Newman measured serum chromium levels in 32 subjects referred for selective coronary arteriography. Patients with catheterization-proven coronary disease had significantly lower serum chromium levels and higher serum triglyceride (TG) than patients without coronary disease. Newman HA, et. al. 24(4) Clinical Chemistry 541-4 (1978).
Chromium is a cofactor in the maintenance of normal lipid and carbohydrate metabolism and its supplementation in normal volunteers has been shown to reduce the levels of total cholesterol, LDL, and apolipoprotein B, and raise levels of HDL. Press, Geller & Evans, 152(1) Western J. Medicine 41-5 (1990). Chromium and two molecules of nicotinic acid form a biologically active complex referred to as “glucose tolerance factor,” which has been reported to enhance the action of insulin. Jeejeebhoy confirmed the its importance in humans when he successfully treated an insulin-resistant diabetic patient with only chromium supplementation after she had become chromium deficient after 3 years of parenteral nutrition. See Lee & Reasner, 17(12) Diabetes Care 1449-1452 (1994). An increase in HDL cholesterol levels was observed after chromium treatment in 23 healthy volunteers and in 72 hypertensive men on beta-blockers. Id.
Other groups have shown chromium to improve the lipid profile, hyperglycemia, and body weight in persons with obesity or diabetes. Type 2 diabetics were treated with 100-mcg chromium BID or 500 mcg BID or placebo. The higher dose group showed lower blood sugar and cholesterol than the placebo group after 2 and 4 months. Anderson, 46(11) Diabetes 1786-91 (1997). Chromium supplementation is also useful for elevated triglycerides. In a prospective, double-blind, cross-over study of 14 men and 16 women supplementation with chromium picolinate for 2 months resulted in a statistically significant reduction in triglyceride levels of 17.4% (133 vs. 161 mg/dl; P<0.05). Lee & Reasner, supra.
Inositol hexaphosphate is a form of nicotinic acid that does not produce a flush. Nicotinic acid (niacin, a water-soluble B vitamin) has been shown to decrease triglyceride, increase HDL cholesterol, lower LDL cholesterol, and decrease lipoprotein(a); it also decreases fibrinogen. Gotto Jr., 82(9A) Am. J. Cardiology 22Q-25Q (1998). It was also shown to increase levels of HDL-cholesterol by 35%, to 1.20+/−0.21 mmol/liter (46.5+/−8.1 mg/dl) at a mean dose of 2,250 mg/day. Zema, 35 (3) Journal Of The American College Of Cardiology 640-6 (2000).
Nicotinic acid was first reported to be hypolipidemic in 1955. Large doses (3 to 6 g/day) rapidly decrease VLDL and LDL and dramatically increase HDL even as much as 20 or 30 mg/dL. But it causes numerous side effects, most importantly an intense flushing and pruritis. Abnormalities of hepatic function, including jaundice, are potentially serious and can occur with 2-g day or delayed-release products. Elevated fasting glucose and delayed glucose tolerance occur frequently and rare side effects include reversible optic maculopathy, toxic amblyopia, arrhythmias, and orthostatic hypotension. See J. Hardman at pp.889-90.
Probucol, a potent antioxidant, was marketed for several years as a hypolipidemic but is now considered only a second or third line agent because of its erratic LDL response and persistent ability to lower HDL levels. It inhibits atherosclerosis in hypercholesterolemic rabbits and non-human primates independently of its hypolipidemic effects, supporting the hypothesis that oxidation is a key step in its development. J. Hardman, supra, at pp. 891-2. Short-term adverse effects include gastrointestinal symptoms, headache, dizziness and increase in the QT interval I many patients.
All of the ingredients used in the compositions of the present invention are obtainable commercially by suppliers well known to those skilled in the art of nutritional supplement formulation. Red yeast rice, although also commercially available, may alternatively be prepared by traditional means.
Indeed, the solid state fermentation of rice by Monascus has a long tradition in East Asian countries; its fermentation dates back at least to the first century AD. Heber, supra. The fermentate is obtained as scarlet to purple red grains, which have the original rice grain structure well preserved. The commercial product is mostly a ground powder, which is know as “Ang Kak” or “Hong Qu” in Chinese The Japanese name for the product is “Koji”.
Traditional or improved red yeast can be prepared by traditional fermentation procedures or their modification. In Ancient China, Monascus was called “Hongqu” and was first described in the 16 th century. B.C.G.M. Von Li Shizhen, Book Of Medicinal Herbs (1590). It was said to have the ability to cure stomach and spleen, to strengthen the blood, and the principle to preserve and endorse the common Qi interdependent. It. The preparation of Hongqu was described as follows:
You take 1 Dan and 5 Dou Jing Mi [the rice]. Clean this with water in a bowl and let it soak for one night. Then you'll cook it like normal food. Further you separate [the rice] in 15 portions and add Jin Pilzmutter. Roll and knead [the mass] to distribute all equally. Form [all] together to one portion and cover it carefully with a silkcloth. First heat [the whole], then take off the silk and splay [the rice pulp]. If the rice pulp is warm, push it together to a heap. Again cover it carefully [with a silkcloth]. Next day at noon again make three heaps [of the pulp], let it rest for a while and form of each part five heaps. Let it rest a short time. Then form all together to a heap. Then let it rest for w while. Then form 15 pieces. Heat a little and then form again a heap. Repeat this 5 times. At the third day fill a big tun with fresh water. Dip short time and process wet and form again a heap. Handle again with this method. At the fourth day again dip it in fresh water. If the fungus falls for half and swim for half at the surface, then again use the method from above: Dip shortly. If the fungus completely is at the surface, it's ready. Take it out and dry it in the sun. If this rice responds, we call it shenghuang, a fresh Yellow Color. If you add Hongqu to alcohol, fish sauces or hacked meat, it results a fresh and appealing red. If it doesn't appeal to the heart his quality isn't very well. If added to medicaments, take stored, old Hongqu, that's good.
http-//www.allok.com/ehistorie.htm, quoting von li Schizhen, supra.
According to another early reported method ( Sung, T'ien Kung K'ai Wu 291-294 (1637, Sun trans. 1966)), red yeast can be prepared by the fermentation of washed and cooked non-glutinous rice using red wine mash, natural juice of Polygonum grass, and alum water. The rice is fermented in open air for 7 days on bamboo trays under very clean conditions. The rice changes its color from white to black, black to brown, and brown to red and then red to yellow, which is then harvested as red yeast. According to an alternative traditional method, non-glutinous rice can be fermented in a hole in the ground lined by bamboo mats, which is securely covered. Fermentation is allowed to take place underground for one year or more, up to four years. WO 98/14177 (1998), at p. 9.
The traditional method has been improved with modern fermentation techniques and equipment to more precisely control temperature, pH, pressure and other fermentation parameters thus reducing the time required. One example is as follows: culture media containing kidney-bean juice 2%, sugar 4%, yeast 0.5% are added to rice (40-80 ml per 100 g) and sterilized by heat while the pH is maintained at pH3 to 8. Red yeast fungi Monascus purpureus Went strain M4184 is added and cultured at 15-35° C. for 9 days. At the end of the fermentation process, the fermentation broth is drained and discarded, while the solid residue is sterilized by heat, dried and crushed into powder. Id. This powder can be used directly in the various compositions and formulations provided in the present invention.
Monascus purpureus is available commercially around the world, through distributors such as Dr. Winfried Behr at Friedrich-Breuer-Str. 86-D-53225 Bonn, Allok at Lachenmeyrs TR. 18a, 81827, Munchen, Germany and Samlong Chemical Co., Ltd., P.B. Box 65, Changzhou, Jiangsu, China.
Coenzyme Q 10 , mixed tocopherols (vitamin E), selenium, chromium, and inositol hexaphosphate are available commercially, in bulk and wholesale, from suppliers well known to those with ordinary skill in the art. For instance, Vitamin E may be obtained from Ava Health PO Box 730, Grove City, Ohio 43123-0730 and Wholesale Vitamins USA, Inc., of Brooklyn, N.Y. offers over 8,000 vitamins at wholesale prices.
Any dosage form may be employed for providing the patient with an effective dosage of the composition. Dosage forms include tablets, capsules, dispersions, suspensions, solutions, capsules, transdermal delivery systems, etc . . . Tablets and capsules represent the most advantageous oral dosage unit form. Any method known to those of ordinary skill in the art may be used to prepare capsules, tablets, or other dosage formulations. Pharmaceutically acceptable carriers include binding agents such as pregelatinized maize starch, polyvinylpryrrolidone or hydroxypropyl methycellulose; binders or fillers such as lactose, pentosan, microcrystalline cellulose or calcium hydrogen phosphate; lubricants such as magnesium stearate, talc or silica; disintegrants such as potato starch or sodium starch; or wetting agents such as sodium lauryl sulfate. Tablets or capsules can be coated by methods well known to those of ordinary skill in the art.
According to one aspect of the invention a composition is provided comprising a pharmaceutically acceptable combination of the composition and at least one carrier. Pharmaceutically acceptable carriers for inclusion into the present compositions include carriers most suitable for combination with lipid-based drugs such as diluents, excipients and the like which enhance its oral administration. Suitable carriers include, but are not limited to, sugars, starches, cellulose and derivatives thereof, wetting agents, lubricants such as sodium lauryl sulfate, stabilizers, tabletting agents, anti-oxidants, preservatives, coloring agents and flavoring agents. Reference may be made to Remington's Pharmaceutical Sciences , (17th ed.1985) for other carriers that would be suitable for combination with the present compositions. As will be appreciated, the pharmaceutical carriers used to prepare compositions in accordance with the present invention will depend on the administrable form to be used.
According to one embodiment of the invention, the novel composition of the present invention comprises red yeast fermented on rice, Coenzyme Q 10 , chromium, selenium and mixed tocopherols and inositol hexanicotinate, and is formulated for oral administration. Oral dosage forms formulated in accordance with standard pharmaceutical practice may be employed. Capsules are a particularly useful vehicle for administering the present composition. The administration of the composition is preferably in accordance with a predetermined regimen, which may be at least once daily and over an extended period of time as a chronic treatment, and could last for one year or more, including the life of the host. The dosage administered will depend upon administration frequency, the blood level desired, other concurrent therapeutic treatments, the condition's severity, whether the treatment is for prophylaxis or therapy, the patient's age, the severity of cholesterol elevation, and the like.
In a preferred aspect of the invention, a composition of the present invention is administered to reduce or control blood cholesterol levels in persons having a total cholesterol of 240 mg/DL (5.95 mmol/L) or higher. In another embodiment of the invention, the compositions are administered to reduce levels of LDL-cholesterol in persons with an LDL-cholesterol of 130 mg/dL (3.41 mmol/L) or higher. In yet another embodiment of the invention, the compositions are administered to reduce triglycerides in persons having blood triglycerides of 200 mg/dL (2.26 mmol/L) or higher. In another embodiment, a composition of the present invention is administered to raise levels of HDL to persons with an HDL-cholesterol of 35 mg/dL (1.04 mmol/L) or lower to reduce the risk of atherosclerosis associated with low HDL levels. The compositions and methods of the present invention may also be utilized to improve or maintain vascular health in specific organ systems including the cardiovascular system, the cereberovascular system, the peripheral vascular system and the intestinal vascular system.
According to an additional embodiment, the compositions of the present invention may be admixed by conventional methods and may be administered by an alternative route such as suppository, spray, liquid, powder, liposome, dermal patch, and inhalant. These methods are well known to those skilled in the art. For example, liposonies may be formulated according to methods such as those of U.S. Pat. No. 5,853,755, to Foldvari, U.S. Pat. No. 4,235,871 to Papahadjopoulos, et al, or U.S. Pat. No. 4,708,861 to Popescu et al (liposome-gel combination). Sublingual and transdermal methods are also well known to those skilled in the art, e.g., U.S. Pat. No. 5,922,342 to Shah, et al describes a sublingual formulation and U.S. Pat. No. 4,997,655 to Nagy, et al describes a transdermal administration method.
In a specific embodiment of the invention, the composition comprises between 50 mg and 3.6 gm red yeast rice, between 5 and 300 mg coenzyme Q10, between 10 mcg and 1 mg chromium, between 5 and 1 g inositol, between 10 mcg and 1 mg selenium, and between 5 IU and 800 IU mixed tocopherols. In yet another embodiment of the invention, the composition comprises between 100 mg and 2.4 gm red yeast rice, between 5 and 250 mg coenzyme Q10, between 10 mcg and 500 mcg chromium, between 10 and 800 mg inositol, between 10 mcg and 500 mcg selenium, and between 5 IU and 400 IU mixed tocopherols. In yet another embodiment of the invention, the composition comprises between 100 mg and 1.2 gm red yeast rice, between 5 and 150 mg coenzyme Q 10 , between 10 mcg and 300 mcg chromium, between 20 and 500 mg inositol, between 10 mcg selenium, and between 5 IU and 200 IU mixed tocopherols. And in yet another embodiment of the invention, the composition may be administered in a daily dose of between 50 mg and 1.6 gm red yeast rice, between 10 and 600 mg coenzyme Q10 and between 5 IU and 800 IU mixed tocopherols.
In a preferred embodiment, the composition is administered in four tablets each comprising about 500 mg red yeast rice, about 15 mg coenzyme Q 10 about 50 mcg chromium, about 13 mg inositol, about 50 mcg selenium, and about 20 IU mixed tocopherols to provide a total daily dose of about 2 gm red yeast rice, about 60 mg Coenzyme Q 10 , about 200 mcg chromium, about 52 mg inositol, about 200 mcg selenium and about 80 IU mixed tocopherols.
The administration of the composition would be in accordance with a predetermined regimen, which would be at least once daily and over an extended period of time as a chronic treatment, and could last for one year or more, including the life of the host. The dosage administered will depend upon the frequency of the administration, the blood level desired, other concurrent therapeutic treatments, the severity of the condition, whether the treatment is for prophylaxis or therapy, the age of the patient, the levels of LDL-cholesterol and HDL-cholesterol in the patient, and the like.
The invention will be further illustrated by the following non-limiting examples:
EXAMPLE 1
A study of the effect of the red yeast rice, 200 mg QID, Coenzyme Q 10 10 mg QID, mixed tocopherols 10 IU QID, selenium 20 mcg QID, chromium 20 mcg QID, and inositol 20 mg QID on HDL-cholesterol, non HDL-cholesterol, and total cholesterol concentrations in the blood of men with elevated cholesterol levels is conducted over a 6 month period. A statistical analysis is performed to compare the resulting cholesterol levels of the test and a control (placebo) group to determine if a significant improvement in cholesterol levels results from administration of the test preparation.
Sixty men having total plasma cholesterol of between 240 and 300 mg/dL are selected for inclusion in the statistical study. Two weeks prior to the start of the study each subject completes a two day dietary intake record and is interviewed by a Registered Dietitian to calculate each individual's daily energy requirement for a basal low fat, low cholesterol National Cholesterol Education Program Step I diet. Each subject is given a booklet published by the American Heart Association containing a long list of foods, along with a calculated “fat gram prescription” which complies with the criteria for the basal diet.
All subjects follow the basal diet for a period of at least fourteen days. After this, baseline blood samples are drawn on two separate days, and the subjects are randomly assigned to one of two treatment groups, the test capsules or matching placebo capsules. Both groups continue on their basal diet and incorporate four tablets of the test composition in the diet.
The effects of the dietary supplementation on total cholesterol, HDL-cholesterol, and non-HDL cholesterol, as well as dietary intake, body mass index, and physical activity are evaluated using multiple linear regression analysis and a standard students t-test. In each analysis the baseline value of the outcome variable is included in the model as a covariant. Treatment by covariant interaction effects is tested by the method outlined by Weigel & Narvaez, 12 Controlled Clinical Trials 378-94 (1991). If there are no significant interaction effects, the interaction terms are removed from the model. The regression model assumptions of normnality and homogeneity of variance of residuals are evaluated by inspection of the plots of residuals versus predicted values. Detection of the temporal outset of effects is done sequentially by testing for the presence of significant treatment effects at 18, 12, and 6 weeks, proceeding to the earlier time in sequence only when significant effects have been identified at each later time period. In addition, differences between groups in nutrient intake, physical activity, and body mass index (ht/wt.sup.2) at each time point are compared using one-way analysis of variance. Changes from the baseline within each group are evaluated using paired t-tests. In addition, analysis of variance is performed on all baseline measurements and measurable subject characteristics to assess homogeneity between groups. All statistical procedures are conducted using the Statistical Analysis System (SAS Institute Inc., Cary, N.C.). An alpha level of 0.05 is used in all statistical tests.
A statistically significant increase in HDL-cholesterol and the decrease in non-HDL cholesterol including LDL-cholesterol are observed in the blood of the treated subjects upon completion of the study but not the controls. The differences between the levels of HDL-cholesterol and non-HDL cholesterol including LDL-cholesterol in the treated subjects and controls are statistically significant.
EXAMPLE 2
A composition of the following formulation was prepared in table form by standard methods:
Red yeast rice
500 mg
Coenzyme Q 10
15 mg
Mixed tocopherols
20 IU
Selenium
50 mcg
Chromium
50 mcg
Inositol
13 mg
4 tablets per day is the recommended dosage for an average weight adult human (70-kg).
The invention has been described in detail with particular reference to preferred embodiment thereof. However, it will be appreciated that those skilled in the art, upon consideration of this disclosure may make variations and modifications within the spirit and scope of the invention.
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This invention provides compositions and methods related to the administration of red yeast rice, coenzyme Q 10 , and chromium, with or without inositol hexanicotinate, selenium, and mixed tocopherols to reduce or control blood cholesterol, triglycerides, low density lipoproteins, or increasing or controlling high density lipoproteins in a mammal, to reduce arterial plaque build-up, atherosclerosis, in a mammal which may be associated with cardiovascular, cerebrovascular, peripheral vascular, or intestinal vascular disorders.
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Pursuant to 35 USC §119, the priority of DE 199 00 681.4 filed Jan. 4, 1999 is claimed.
BACKGROUND OF THE INVENTION
Because of the increasing use of nucleic acids in animal and human medicine, such as in gene therapy, there has been a growing need for making these materials available in greater purity. The term “nucleic acids” is to be understood as a collective term, encompassing deoxyribonucleic acids (DNA), ribonucleic acids (RNA), antisense RNA and nucleic acids with modified bases or structure. Endotoxins from gram-negative bacteria such as E. coli are often present in nucleic acids and when, during the course of recovery and isolation of such acids, particles of bacterial cell walls are not completely eliminated, there exists the possibility of the endotoxins finding their way to the final nucleic acid solutions being used in, say, a medical study. The introduction of endotoxins into patients must, of course, be avoided at all costs, since, where humans and experimental animals are concerned, endotoxins cause serious symptoms of illness, including fever and inflammation of blood vessels, activate blood-clotting and stimulate the production of antigens by the immune system.
EP 0 853 123 A1 discloses a process for the purification of nucleic acids in aqueous solutions, in which the solution containing nucleic acid and not cleared of endotoxins is flowed tangentially over ultrafiltration membranes with exclusion limits of 1 to 1000 kilodaltons. When this is carried out, because of its large size, a molecule of nucleic acid should not pass the membrane. At the same time, substances of lesser molecular weight, such as endotoxins, migrate through the membrane and/or are adsorbed on the membrane. The disadvantages of such an ultrafiltration technique are the considerable cost of the necessary apparatus, the large amount of time consumed (by virtue of the relatively low filtration speed common to the use of ultrafiltration membranes), the requirement for using large volumes of liquid feed solution (making the procedure unsuitable for laboratory scale work) and the tendency for dissolved proteins to prematurely blind the membranes.
These disadvantages are overcome by the present invention, which provides a process which can be carried out quickly and simply for the purification of aqueous solutions of nucleic acids, by which a lasting reduction of the endotoxin content is achieved, and which is suitable for both large- and small-scale treatments.
BRIEF SUMMARY OF THE INVENTION
The process of the present invention comprises filtering an endotoxin-containing aqueous nucleic acid feed solution through at least one layer of a microporous weakly basic anion exchange membrane, thereby binding both endotoxins and nucleic acid(s) onto the membrane. Particles greater in size than the pores of the anion exchange membrane are excluded from passage through the membrane and are restrained on the feed side of the membrane array. Subsequently, bound nucleic acid(s) are selectively eluted from the membrane by a buffered neutral salt solution having a higher ionic strength than the nucleic acid feed solution, leaving endotoxins bound to and/or adsorbed onto the membrane. The process results in the recovery of an essentially endotoxin-free nucleic acid solution. Optionally, the nucleic acid elution step may be preceded by a washing with a buffer of lesser ionic strength than that of the elution solution, in order that impurities such as proteins, which have collected in membrane's pores or are weakly bound to the membrane may be separated therefrom.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In a preferred embodiment of the invention, the aqueous nucleic acid feed solution is adjusted to a pH in the range of 5 to 9.5 and has an ionic strength of ≦0.1M, while the pH of the buffered neutral salt solution is adjusted to a value of 5 to 9.5 with an ionic strength of from about 0.5 to about 3M. In a particularly preferred embodiment, the pH of the feed solution is adjusted to about 8 and its ionic strength is about 0.01M, while the pH of the buffered neutral salt solution is about 5.5 with an ionic strength of between about 1 and 2 M, and most preferably 0.7 M when sodium chloride is the neutral salt.
For increasing the security of the filtration and the capacity for purification, more than one layer of the membrane may be employed, particularly in the form of a laminated pack as is described in U.S. Pat. No. 5,618,418 or a wound filter as taught in DE OS 197 11 083, the pertinent disclosures of which are incorporated herein by reference. The membranes can also be in the form of one or more pleated membrane cartridges, as they are usually used in sterile filtration.
Suitable weakly basic anionic exchange membranes include those containing primary, secondary or tertiary amine groups, which are affixed to the membrane either singly or in combination with one another. Such membranes are based on immobilizing weakly basic groups onto the surface of large pore size, modified membranes such as cellulosic membranes, with diethylamine for example being the weakly basic anion exchanger. Such a membrane is commercially available from Sartorius AG of Gottingen, Germany and sold as Sartobind®D.
A preferred subset of such anion exchange membranes are those which possess predominately or exclusively tertiary aliphatic amines as the ion exchange groups, wherein at least one of the alkyl groupings contain 2 to 5 carbon atoms with those containing 3 or more carbon atoms being branched or straight chain. A particularly preferred ion exchange group is a tertiary amine, having two ethyl groups. Such membranes preferably have a pore size range of from 0.01 to 30 μm, even more preferably of from 0.1 to 8 μm. The membranes in accord with the invention should not be confused with those anion exchange membranes used in electrodialysis, even though the pore size ranges may be the same as those preferred in the present invention. See EP 0 538 315 B1 and EP 0 527 992 B1. Other membranes suitable for use in the present invention are polyamides, polysulfones and polyvinylidene fluoride.
In the filtration of an aqueous nucleic acid- and endotoxin-containing feed solution through a weakly basic anion exchange membrane, both nucleic acids and endotoxins are bound to the membrane, probably by an ionic mechanism. The binding occurs not only on the outer surface of the membrane, but also on the inner surfaces of the membrane pores.
In a rather surprising aspect of the present invention, the inventors have discovered, that upon subsequent contact with a neutral salt solution of relatively higher ionic strength than the feed solution, the nucleic acid component is selectively eluted, meaning that it is reversibly bound, while at least a majority of the endotoxin component remains irreversibly bound to and /or adsorbed onto the membrane. This effect does not occur with the use of strongly basic anion exchange membranes, such as, for example, Sartobind™ Q type membranes (Sartorius AG); specifically, while the strongly basic anion exchange membranes do bind both the nucleic acid and endotoxin components, upon subsequent contact with a neutral salt solution of a higher ionic strength both components are eluted, thus permitting endotoxins to pass through the membrane along with nucleic acid(s), an undesirable result. Porous membranes having no ion exchange groups are likewise unsuitable for purification of nucleic acids. Thus, for example, a polypropylene membrane adsorbs both endotoxins and nucleic acids irreversibly, so that selective elution of one of the two substances is not possible.
The anion exchange membranes used in the present invention exhibit a high flux, so that filtration time is held to a minimum. The use of the anion exchange membranes enables the filtration of both small and large volumes, the latter containing nucleic acids in extremely dilute concentrations. This is due to the fact that the nucleic acid molecules are ionically bound by the filtration through the membrane and can subsequently be eluted from the membrane with relatively small liquid volumes. This leads to a concentration effect of several orders of magnitude. If essentially micro-quantities of nucleic acids are only available (as in the case of lab work), it has proven useful to employ a small centrifugation tube as a separation means to be used in conjunction with weakly basic anion exchange membranes. Such an apparatus is commercially available as Centribind® D (Sartorius AG).
The invention will be more fully understood by study of the following examples. In the examples, endotoxin from the firm Pyroquant, Charge 11717 was used and the quantitative determination of endotoxin concentration was accomplished with the Limulus Amoebo-Lysat Test (LAL Test) of Pyrogent, Ch. 2196, sensitivity 6 pg/mL. Weakly basic anion exchange membranes (Sartobind® D) were used, as well as strongly basic anion exchange membranes (Sartobind® Q). Polypropylene (PP) membranes having a nominal pore diameter of 0.2 μm were from Akzo Nobel, class 2EPPHF, type 0884.
Example 1
Three-membrane arrays of 25 mm diameter membranes of the weakly basic anion exchange membrane, the strongly basic anion exchange membrane and the polypropylene membrane were placed in stainless steel filter holders and first flushed through with 20 mL of water for rinsing and wetting the membranes. Subsequently, 5 mL of a feed solution of 100 μg DNA of the plasmid pSE 420 (order number E7772 from SIGMA, of Deisenhofen, Germany) and 3 μg/mL endotoxin in a buffer of the composition 10 mM tris-HCl, pH 8.0 and 1 mM EDTA (hereinafter referred to as “TE buffer”) were filtered through the membranes and the filtrate retained. Thereafter 20 mL TE buffer was directed through the membrane array, in order to wash non-bonded contamination out of the membranes. Then elution of the DNA was accomplished by directing 4 mL of a 2 M NaCl solution in TE buffer to obtain an eluate.
The filtrate and the eluate were sequentially diluted in a ratio of 1:10 with TE buffer, and tested by the LAL Test for the presence of endotoxins. With a UV spectro-photometer set at a wavelength of 260 nm (the absorption peak for DNA), the concentration of DNA in the filtrate and in the eluate was also determined. The yield of DNA was then set at 100%. In Table 1, the concentrations of DNA and endotoxin are shown, each reported concentration being the average of at least two trials.
TABLE 1
wt % DNA
wt % Endotoxin
Membrane
in filtrate
in eluate
in filtrate
in eluate
Sartobind ® D
3.5
50
2.0
1.6
weakly basic
PP*
10
1.2
0
0
Sartobind ®
3.3
33
17
16
strongly basic
*irreversible binding
Example 2
In a first trial three of the same weakly basic anion exchange membranes as in Example 1 were stacked in a stainless steel filter holder and first flushed with 20 mL water. Subsequently, 3 mL of the same feed solution of Example 1 were filtered through the membranes and the filtrate retained. Thereafter 20 ml TE buffer was directed through the membrane array, in order to wash out non-bonded contamination. Elution was accomplished as in Example 1.
In a second trial elution was conducted with a solution of 2 M NaCl in 10 mM sodium acetate buffer at pH 5.5. The filtrate and eluate were sequentially diluted in a ratio of 1:10 with TE buffer and tested for the presence of endotoxin and DNA as in Example 1; the reported concentrations represent the average of at least two trials.
TABLE 2
wt % DNA
wt % Endotoxin
Trial No.
in filtrate
in eluate
in filtrate
in eluate
1
11
68
2.7
1.6
2
11
58
0.7
.16
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
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There is disclosed a membrane process for the purification of nucleic acids in aqueous solutions whereby a lasting reduction of endotoxin content is achieved. The process is suitable for small or large volumes and can be carried out quickly and with simple apparatus.
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FIELD OF THE INVENTION
This invention relates to fuel control for a fuel injected engine and particularly to a method and apparatus for a closed loop fuel control.
BACKGROUND OF THE INVENTION
The control of internal combustion engines by microcomputer based controls has become commonplace and has made possible the calculation of optimum fuel quantity to be delivered to each individual cylinder. The use of fuel injectors for direct injection into the cylinders or at the intake port of each cylinder provides a practical means of delivering fuel to each cylinder. Prior to this invention only open loop fuel control has been used for the lack of an ability to measure the actual amount of fuel delivered by an injector. Therefore injectors were calibrated when new to correlate the injector control signal with the amount of fuel injected. Such calibrations are approximate because the injection amount varies with engine operating conditions and with age and wear on the injector. As a result, the actual delivery is not known and there is a tendency for the fuel quantity to deviate from the calculated value.
There are advantages to controlling the fuel to the individual cylinders. For example, such control would make fuel balancing possible, i.e., equal amounts of fuel could be delivered to all cylinders. Conversely, deliberate variances of fuel delivery could be accurately managed if available control parameters required that for the best operation.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a method and apparatus for closed loop fuel control. It is a further object to provide such control on an individual fuel injector basis.
The invention is carried out by means for controlling the fuel quantity delivered by a fuel injector to an engine comprising: a positive displacement fuel injector activated by a control signal and having a plunger which moves in proportion to the amount of fuel delivered, means for measuring plunger displacement and generating a displacement signal representing fuel quantity, command means for generating a desired fuel signal representing desired fuel quantity, control means responsive to the desired fuel signal for generating the control signal to activate the injector for effecting a fuel delivery, and the control means including a closed loop means responsive to the desired fuel signal and the displacement signal for adjusting the fuel delivery to the engine to match the actual quantity to the desired quantity.
The invention is further carried out by the method of controlling the fuel quantity delivered to an engine by a fuel injector having a positive displacement plunger comprising the steps of: calibrating the plunger displacement versus fuel quantity, generating a command value representing the desired fuel quantity, pulsing the fuel injector by a pulsewidth modulated control signal to deliver fuel to the engine, measuring the displacement of the plunger, computing the fuel quantity from the displacement in accordance with the calibration, comparing the fuel quantity to the command fuel value to determine an error, and adjusting the control signal pulsewidth to reduce the error so that the injected fuel quantity substantially equals the command fuel value.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other advantages of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings wherein like references refer to like parts and wherein:
FIG. 1 is a schematic diagram of a fuel injector control circuit with each fuel injector having a feedback sensor according to the invention,
FIG. 2 is a control circuit and injector schematic for the system of FIG. 1,
FIG. 3 is a pulsewidth versus injected fuel quantity calibration curve,
FIG. 4 is flow diagram of the closed loop fuel control process according to the invention,
FIG. 5 is a diagram of pulsewidth versus cycle number for a test run on a four cylinder engine, and
FIG. 6 is a diagram of injection quantity versus cycle number for the same engine test as FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The ensuing description is for a fuel injection system developed specifically for a direct-injection stratified-charge engine. It is expected that the same principles or even the same circuit will apply to other engines having port fuel injection for each cylinder, as well as to diesel engines. The system is predicated upon the availability of a fuel injector having a plunger movement substantially proportional or at least precisely calibrated to the amount of fuel delivered and to a sensor coupled to the fuel injector for measuring the plunger movement, thus providing feedback information on the actual fuel amount. The invention is not directed to the specific structure of such an injector/sensor but rather is directed to the method and the system using the properties of that type of injector.
FIG. 1 illustrates the system as applied to a four cylinder engine with a fuel injector 10 for each cylinder. Each injector is coupled to an injector controller 12 by a control line 14 and a feedback line 16. An engine control computer 18 has a number of inputs including but not limited to accelerator position, engine speed, manifold absolute pressure (MAP), and an EGR signal. The computer issues four output pulses on lines 20 for each injector. The pulses are timed for correct application to the injectors 10 and are coupled through the injector controller 12. The widths of the pulses determines the fuel quantity delivered by the injectors. The challenge in such a control is to tailor each pulsewidth to a value which results in the precise desired fuel quantity. The feedback is used for that purpose. The feedback lines 16 from the injectors carry signals which are processed by the injector controller 12 and are fed back to the computer via lines 22 and an analog to digital converter 24.
FIG. 2 relates to just one channel of the system which is sufficient to control one injector and more fully illustrates the source of the feedback information. The injector controller 12 includes a driver circuit 26 which processes the pulsewidth signal on line 20 to output an injector actuating pulse on line 14 and a sensor circuit 28 which processes the sensor signal on line 16. The injector 10 is of the positive displacement type having a plunger 30 in a bore 32 which is filled with fuel from a fuel line 34 and has an orifice or spring loaded valve 36 for emitting the fuel when the plunger is stroked in the bore.
The amount of plunger displacement is directly proportional to the amount of fuel delivered. The plunger is operated by an armature 38 which is controlled by a solenoid 40. The control pulse on line 14 energizes the solenoid 40 to move the armature 38 and plunger 30. The wider the pulse on line 14 the further the plunger is displaced and the greater the fuel amount. The fuel amount is not, however, directly proportional to the pulsewidth. The injector must be calibrated at several pulsewidths for at least approximate fuel amounts to derive a pulsewidth versus fuel amount calibration curve. The direct plunger actuation by a solenoid is only an example of a fuel injection mechanism responsive to an electrical pulse. Another example is a plunger operated by hydraulic pressure which in turn is controlled by an electrically operated valve. In any event, the plunger movement is measured by a sensor, shown in the drawings as an LVDT 42 responsive to the armature position. The LVDT is coupled to a sensor circuit 28 in the controller 12 which develops a voltage proportional to armature position with respect to some reference point. A peak-hold circuit 46 retains the maximum voltage of the sensor circuit and this value is sent to the computer 18 as representing the maximum plunger displacement and thus the actual fuel amount. In the event that the fuel amount is not exactly proportional to the measured displacement, a second calibration curve of fuel amount versus sensor voltage is made.
Both calibration curves, i.e. pulse width versus fuel quantity and fuel quantity versus sensor voltage, are stored in the computer 18 in the form of equations. FIGS. 3 illustrates the pulsewidth versus fuel quantity calibration curve. This is a typical curve empirically determined for a particular injector and is represented by the polynomial BASE=1.257+0.00412Q+0.000425Q 2 , where BASE is the base pulsewidth in milliseconds and Q is the injected quantity in mm 3 /stroke. The actual injected quantity AQ versus voltage V for the same injector is a straight line represented by AQ=-27.1398+23.744V.
The computer 18 has a fuel demand algorithm for calculating the desired fuel quantity Q and a pulsewidth algorithm responsive to the quantity Q and the sensor feedback signal representing actual fuel quantity AQ to calculate the pulsewidth necessary to eliminate the error, i.e. the difference between Q and AQ. The fuel demand algorithm may be any of the well known fuel control programs in common usage. The pulsewidth algorithm is set forth in the flow chart of FIG. 4. That program reads the desired quantity Q as determined by the fuel demand algorithm, computes the pulsewidth BASE from the equation for the pulsewidth versus fuel calibration curve, reads the sensor voltage and computes the actual quantity AQ from the equation for the voltage versus fuel quantity calibration. Next, the fuel error is computed as E i =Q-AQ (where the subscript i refers to the present engine cycle) and a proportional-integral-differential control is implemented by computing the integral term SUM i =SUM i-1 +E i , computing the differential term DIFF=E i -E i-1 , and computing the DELTA term from DELTA=K P E i +K I SUM i +K D DIFF. Finally the BASE and DELTA solutions are added to yield the corrected value TOTAL PULSEWIDTH which is the control value sent to the injector controller. The constant K P for the proportional term is determined from the differential of the pulsewidth versus fuel quantity curve at a point midway between the values of Q and AQ and multiplying by a constant, i.e. K P =K(0.00412+0.00085Q a ) where Q a =(Q+AQ)/2. The values of K, K I and K D are determined empirically.
If the pulsewidth versus fuel quantity calibration were precise and if the injection could be faithfully executed without deviation from the calibrated values under every engine condition the closed loop system would not be necessary. In practice, however, it has been demonstrated that even the precise calibration changes with age and wear but it does form a workable starting place for the closed loop system. That is, the initial engine cycle upon starting requires some reasonable fuel quantity for successful combustion. A test sequence for a four cylinder engine having crudely calibrated injectors illustrates this point and further illustrates the effectiveness of the closed loop fuel control.
The test is documented in FIG. 5 which charts pulsewidth for each injector versus the engine cycle and FIG. 6 which charts AQ for each injector, as measured by sensor voltage, versus engine cycle. In FIG. 5, the fuel demand quantity is a constant 17.1 mm 3 per stroke and the calibration curves for that value yielded pulsewidths ranging from 1450 to 1900 microseconds for the several cylinders for the 0th cycle which operates open loop. During that cycle the default value of the AQ feedback signal is zero so that the BASE pulsewidth is not adjusted. FIG. 6 for the same condition indicates that the corresponding AQ, as calculated from sensor voltage after the injection event, ranges from 8.6 to 15.3 mm 3 . This was adequate for engine starting. The closed loop then was effective for subsequent cycles and the AQ quickly reached the goal of 17.1 mm 3 for all cylinders, thus showing the effectiveness of the control. FIG. 5 shows that when stabilized, the pulsewidths ranged from 1880 to 2380 microseconds which reflects the responses of individual injectors to the control pulses.
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In an engine having direct fuel injection or injection at individual intake ports, the fuel injectors are of the positive displacement type and are equipped with plunger displacement sensors to yield a displacement signal representing the quantity of fuel injected. This signal is used as feedback to a closed loop PID control which compares the injected quantity to a demand quantity to determine an error and calculates a control pulsewidth which reduces the error eventually to zero. An open loop injector calibration of pulsewidth versus approximate fuel quantity is used as a base pulsewidth to which the closed loop adds a correction value.
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BACKGROUND OF THE INVENTION
1. Cross Reference to Related Applications
This application is a division of application Ser. No. 431,588 filed Sept. 30, 1982.
This application is related to PROCESS FOR PRODUCTION OF AROMATICS (BTX) FROM HEAVY HYDROCARBONS (filed Oct. 20, 1982; Ser. No. 06/435,608) (Swami Narayanan, Herman N. Woebcke and Axel R. Johnson) filed coincidentally with this application as a result of a common development effort.
2. Field of the Invention
This invention relates generally to thermal cracking of hydrocarbons to produce olefins. More particularly, the invention relates to cracking heavy hydrocarbons such as naphtha, kerosene, atmospheric gas oil, vacuum gas oil and resid to produce olefins. Most specifically, the invention relates to the use of cracked light hydrocarbons as a diluent and heat source for cracking heavy hydrocarbons.
3. Description of the Prior Art
At present, there are a variety of processes available for cracking heavy hydrocarbons to produce olefins. Typically, the hydrocarbon to be cracked is delivered to a furnace comprised of both a convection and radiant zone or section. The hydrocarbon is initially elevated in temperature in the convection zone and thereafter delivered to the radiant zone wherein it is subjected to intense heat from radiant burners. An example of a conventional furnace and process is shown in U.S. Letters Pat. No. 3,487,121 (Hallee). After cracking, the effluent is rapidly quenched to terminate the cracking reactions.
It is also now well known that steam is used as a diluent in cracking hydrocarbons. The dilution steam reduces the mixture molecular weight and reduces the hydrocarbon partial pressure in the cracking coils. The reduced partial pressure inhibits the formation of undesirable coke products on the interior of the radiant tubes. In addition increasing dilution steam increases yield of desirable components during cracking. On the other hand, the use of steam in the hydrocarbon stream requires larger furnace capacity and equipment than would be necessary for the hydrocarbon without steam. Further, when steam is used, energy and equipment must be provided to generate and superheat the steam. In balance, the economic optimum has favored operation at minimum steam-to-hydrocarbon ratio.
In the past, light hydrocarbons were generally used to produce olefins in the thermal cracking process. In general, light hydrocarbons can be cracked with dilution steam in the range of 0.3 to 0.6 pound of steam per pound of hydrocarbon. More recently, the demand for olefins has exceeded the availability of light hydrocarbons. Thus, the industry has turned to heavier hydrocarbons as a feedstock for olefin production. It has been found that a greater quantity of dilution steam is required for the heavier hydrocarbons than for the lighter hydrocarbons. It has been found that the heavy hydrocarbons require from about 0.7 to 1.0 pound of dilution steam per pound of hydrocarbon. As a general proposition, the higher quantities of dilution steam are needed for heavier hydrocarbons to obtain the desired partial pressure of the hydrocarbon stream which is required to suppress the coking rates in the radiant coils during thermal cracking. Correlatively, the dilution steam requirement demands increased furnace size and greater utility usage.
The industry has, in the past, suggested diluents other than steam in thermal cracking. For example, in U.S. Letters Pat. No. 4,021,501 (Dyer) the use of butene as a diluent in the cracking process is suggested. In U.S. Letters Pat. No. 4,002,556 (Satchell) the suggestion is made that a hydrogen donor diluent be used. Therein, the hydrogen donor is a material that has been partially hydrogenated and readily gives up hydrogen under thermal cracking conditions. This material is injected into the cracking unit at a plurality of points to maintain the ratio of hydrogen transfer to the ratio of cracking at a substantially uniform level through the unit.
The industry has also used hydrocarbon as a quench material for direct quench of the pyrolysis effluent. In U.S. Letters Pat. No. 2,928,886 (Nisbet), cracked gas effluent is quenched by direct contact with an oil-water emulsion (5%-15% oil). Further, the use of aromatic hydrocarbons and gas oils as a quench oil to increase the olefin yield of cracked feedstocks is known. In French Patent No. 1349293 (Metallgesellschaft), and Japanese 41/19886 (Sumitomo Chemical) that basic concept is disclosed.
Very recently a process has been developed for cracking a light hydrocarbon under high severity conditions and thereafter coincidentally quenching the cracked effluent with a heavy hydrocarbon and cracking the heavy hydrocarbon quench at low severity by use of the sensible heat from the cracked effluent. U.S. Letters Pat. No. 4,268,375 (Johnson).
In all of the processes known, there is no process in which heavy hydrocarbon is initially partially cracked with a minimal amount of dilution steam and thereafter cracked to completion at high severity conditions using cracked light hydrocarbon effluents as a diluent.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process in which heavy hydrocarbon can be cracked using a minimal amount of dilution steam, i.e., one in which the dilution steam is well below the conventional 0.7 to 1.0 pound of steam per pound of hydrocarbon.
It is another object of the present invention to crack heavy hydrocarbon and light hydrocarbon in a combined process.
It is a further object of the present invention to provide a process in which light hydrocarbon is cracked essentially to its maximum conversion at a high coil outlet temperature and heavy hydrocarbon is simultaneously cracked to an intermediate stage and thereafter the cracked light hydrocarbon effluent is joined with the partially cracked heavy hydrocarbon effluent to serve as the diluent for the heavy hydrocarbon.
It is a still further object of the present invention to provide a process for cracking heavy hydrocarbons in which the equipment size, and the utility requirements, for the process is reduced below that presently required to crack heavy hydrocarbon without a loss in yield of desirable olefins when compared to conventional cracking at high steam dilutions.
It is another and further object of the present invention to provide substantial utility reduction, savings in installation costs due to reduced service area requirements, and minimization of associated dilution steam generation equipment.
To this end, a process and apparatus are provided to crack light hydrocarbon feedstock and heavy hydrocarbon feedstock in a combined system.
The light hydrocarbon feedstock is cracked in a first stage conventionally, with the customary requisite amount of dilution steam. Cracking of the light hydrocarbon feedstock proceeds by first providing dilution steam and elevating the temperature of the feedstock in the convection section of a furnace and thereafter cracking the light hydrocarbon feedstock to maximum conversion in the radiant zone of the furnace.
At the same time, the heavy hydrocarbon feedstock is provided with a minor amount of dilution steam and elevated in the convection zone of a furnace to a temperature in the range of 1000° F. Thereafter, the heavy hydrocarbon feedstock is partially cracked in a radiant zone at temperatures above 1100° F. and up to 1450° F.
The light hydrocarbon feedstock cracked at high conversion and the partially cracked heavy hydrocarbon feedstock are combined. Further cracking of the heavy hydrocarbon can take place in one of several modes:
(i) in the radiant zone--under direct firing control
(ii) in the radiant zone--but away from the direct line of radiant exposure
(iii) adiabatically--totally insulated from radiant and convection contribution, may be external to the furnace, and
(iv) by any combinations of these modes.
In the common line, the cracked pyrolysis gas from the light feedstock is, in effect, quenched to terminate or reduce the reactions of the light effluent. Simultaneously, the heat from the light hydrocarbon feedstock cracked at high conversion provides additional heat to further crack the heavy hydrocarbon feedstock.
The furnace design developed for the process employs a section of the furnace suited to partially crack the heavy hydrocarbon feedstock, a section to maximize the conversion of a light hydrocarbon feedstock, and a section to provide discrete regulation of the heat supplied to the common line, in which the light hydrocarbon pyrolysis gas is quenched and the partially cracked heavy hydrocarbon effluent is further cracked to the desired level of conversion.
Conventional quenching methods and a conventional separation system are also provided to complete the process.
DESCRIPTION OF THE DRAWINGS
The invention will be better understood when viewed in combination with the drawings wherein:
FIG. 1 is a schematic diagram of the process of the present invention shown as adapted for application using a conventional pyrolysis furnace; and
FIG. 2 is a schematic drawing of a furnace specifically designed to crack light and heavy hydrocarbons in accordance with the process of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As has been previously indicated, the process of the present invention is directed to provide a means for cracking heavy hydrocarbon feedstock without the need for the large amount of dilution steam. Previously, this large steam requirement was necessary to provide the partial pressures required to suppress coke formation in the radiant section of the cracking furnace. The heavy hydrocarbon feedstocks contemplated are naphtha, kerosene, atmospheric gas oil, vacuum gas oil and resid. Further, the process of the invention is capable of being performed in conventional furnace apparatus, however, as will be seen, a furnace uniquely suited and specifically designed for the process of the present invention is also provided. The process of the invention is conveniently characterized as "DUOCRACKING".
As best shown in FIG. 1, a conventional furnace 2 comprised of a convection zone 6, and a radiant zone 8, is provided with convection and radiant section lines capable of performing the process of the present invention.
The convection zone 6 of the present invention is arranged to receive a feedstock inlet line 10 for the light hydrocarbon feedstock and an inlet line 18 for a heavy hydrocarbon feedstock. Coils 12 and 20 through which the light hydrocarbon feedstock and heavy hydrocarbon feedstock pass respectively are located in the convection zone 6 of the furnace 2. Lines 14 and 22 are provided to deliver dilution steam to the convection coils 12 and 20, respectively.
The radiant zone 8 is provided with coils 16 for cracking the light hydrocarbon feedstock to high conversion, and coils 24 for partially cracking the heavy hydrocarbon feedstock. A common coil 26 is also provided in which the heavy hydrocarbon feedstock is cracked to high severity by any one of the four modes explained earlier and the effluent from the light hydrocarbon is in effect, quenched to terminate the reactions. An effluent discharge line 28 is provided and conventional quench equipment such as a USX (Double Tube Exchanger) and/or a TLX (Multi-Tube Transfer Line Exchanger) are afforded to quench the cracked effluent.
The system also includes a separation system 4 which is conventional. As seen in FIG. 1, the separation system 4 is adapted to separate the quench effluent into residue gas (line 32), ethylene product (line 34) propylene product (line 36) butadiene/C 4 product (line 38), raw pyrolysis gasoline/BTX product (line 40), light fuel oil product (line 42), and fuel oil product (line 44).
Optionally, a line 24A is provided to deliver the partially cracked heavy hydrocarbon directly from the convection coil 20 to the common line 26. Under certain conditions, the heavy hydrocarbon can be partially cracked in convection zone 6 thereby rendering further cracking in the radiant zone unnecessary.
In essence, the process of the present invention is conducted by delivering a light hydrocarbon feedstock such as ethane, propane, normal and iso-butane, propylene, mixtures thereof, raffinates or naphthas through line 10 to the convection coils 12 in convection section 6 of furnace 2. Heavy hydrocarbon feedstock such as naphtha, kerosene, atmospheric gas oil or vacuum gas oils are delivered through line 18 to the convection coils 20.
Dilution steam is delivered by line 14 to convection coils 12 through which the light hydrocarbon feedstock is being passed. It is preferable that the dilution steam be superheated steam at temperatures in the range of 800° F. to 1000° F. The dilution steam is mixed with the light hydrocarbon feedstock at approximately 0.3 to 0.6 pound of steam per pound of feedstock. The composite of light feedstock and dilution steam is elevated in temperature to approximately 1000° F. to 1200° F. in convection section 6. Thereafter, the heated hydrocarbon is passed through coil 16 in radiant section 8 of furnace 2. In the radiant section, the light hydrocarbon feedstock is preferably cracked under high severity conditions to temperatures between 1500° F. and 1700° F. at residence times of about 0.1 to 0.3 seconds.
At the same time, the heavy hydrocarbon feedstock is delivered through line 18 to convection coils 20 in convection zone 6 of furnace 2. Dilution steam is delivered by line 22 to convection coils 20 to mix with the heavy hydrocarbon in a ratio of about 0.15 to 0.20 pound of steam per pound of hydrocarbon. The mixture is elevated to a temperature between 850° F. and 1200° F.--preferably 900° F. and 1000° F. in convection zone 6 of furnace 2. Thereafter, heavy hydrocarbon feedstock from convection section 6 is delivered to radiant coils 24 wherein it is partially cracked under low to medium severity conditions to a temperature of about 1250° F. to 1450° F. at residence times of about 0.05 to 0.20 seconds.
The partially cracked heavy hydrocarbon feedstock is delivered to the common line 26 and the completely cracked light hydrocarbon pyrolysis gas from line 16 is also delivered to common line 26. In common line 26, the completely cracked light feedstock effluent provides heat to effect more complete cracking of the partially cracked heavy hydrocarbon. Concomitantly, the light hydrocarbon feedstock effluent is quenched by the lower temperature partially cracked heavy hydrocarbon feedstock in common line 26. The composite mixture is further cracked, then quenched in conventional quench equipment and thereafter separated into the various specific products.
Furnace 102 of FIG. 2 has been developed particularly for the process of the present invention. As in the conventional furnace, a convection zone 106 and a radiant zone 108 are provided. However, a separate coil 120 in the convection zone for the passage of heavy hydrocarbon is provided and a separate coil 112 for the passage of light hydrocarbon are also provided.
Radiant zone 108 is arranged with a radiant coil 116 and a plurality of burners 140 for high severity cracking of the light hydrocarbon feedstock. Practice has taught that coil 116 can be a multi-tube coil, i.e. at least two tubes, with the burners having a composite capacity of firing to achieve a conversion level of about 60 to 65% ethane, 85 to 95% propane, 90 to 95% C 4 's, 95 to 98% of raffinate or light naphtha conversion. A short coil of 116 will provide a low residence time but higher coil outlet temperature. Such as short coil will enhance selectivity. A longer coil of 116 which can bring about the above-mentioned conversions of lighter components can also be used to provide a lower coil outlet temperature. Either the longer or short coil can be used to advantage as is known to those who are well versed in this art.
An array of radiant burners 140 will provide the necessary heat to bring about high severity cracking of the light hydrocarbon in coils 116.
Radiant section 108 is also provided with a coil 124 for partial cracking of the heavy hydrocarbon which can be a single tube. An array of burners 142 will provide the heat necessary to partially crack the heavy hydrocarbon.
An array of burners 146 located opposite common tube 126 will provide discrete heating of common tube 126 in which the heavy hydrocarbon is completely cracked and the light hydrocarbon effluent is quenched.
The heat available in the light hydrocarbon effluents now provide enthalpy for continued decomposition of heavy hydrocarbon. By selecting appropriate flow quantities of light and heavy hydrocarbon streams, the requisite amount of heat for the completion of heavy hydrocarbon decomposition can be provided.
However, tube 126 can now be discretely fired by burners 146 so as to provide additional heat needed over and above that supplied from the light hydrocarbon effluents.
Maintaining coil 126 inside the firebox environment provides an atmosphere for the heavy hydrocarbon to isothermally absorb the heat from the light effluents under controlled conditions. The heavy hydrocarbon which instantly reaches a higher temperature due to mixing is maintained at the mixed temperature of about 1400° F. for a short residence time of about 0.02 to 0.05 second to bring about the desired conversion level.
Maintaining coil 124A shadowed or insulated from direct radiation provides an atmosphere for heavy hydrocarbon to adiabatically absorb heat from light effluents. The successive introduction of light hydrocarbon cracked effluents into the heavy hydrocarbon stream in coil 124A, would also provide a controlled increasing temperature profile with respect to heavy hydrocarbon.
Higher conversion levels of heavy hydrocarbon are achieved by increasing the mixture temperature to 1500°-1600° F. by adding additional heat if required by burners 146. Under these increased firing conditions, lower residence times of 0.01 to 0.02 seconds effect the complete conversion of the heavy hydrocarbons.
An example of the process of the present invention compared with a conventional process reveals the yield advantages of the invention. In the example, the following process conditions were maintained:
______________________________________ Conventional DUOCRACKING______________________________________Feedstock Kuwait gas oil Kuwait gas oil 100 lbs/hr 100 lbs/hr (line 18) equivalent equivalent Ethane 59 lbs/hr (line 10)Gas OilCracking Severity* 2.2 2.2Convection Exit (line 20) (line 12)Temperature 1050° F. 1000° F. 1160° F.Dilution Steam 1.07 0.18 0.5lb/lb HydrocarbonRadiant Zone (line 24) (line 16)Residence Time 0.3 sec 0.1 0.25Exit Temperature 1480° F. 1453° F. 1525° F.Supplementary Dilutionlb of cracked 0.0 0.89 (line 26)Ethane + Steam/lbof heavy gas oilTotal Dilution lb/lb 1.07 1.07of heavy gas oilDUOCRACKING CoilResidence Time 0.06Exit Temperature 1525° F.Yields, Wt % of HGOCH.sub.4 12.5 13.0Ultimate C.sub.2 H.sub.4 23.0 26.4C.sub.3 H.sub.6 13.0 13.2C.sub.4 H.sub.6 3.5 2.6Total Olefins 39.5 42.2C.sub.5 -400F 16.1. 14.3BTX 9.7 10.1400F+ 25.9 24.4______________________________________ *Defined as kinetic severity function, analytical.
The DUOCRACKING yield data reported in the Example are only the gas oil contributions in the combined cracking process. The ethane contribution was obtained by allowing the ethane to crack under identical process conditions as the mixture. The ethane contribution was then subtracted from the mixture yields to obtain only the gas oil contribution under DUOCRACKING process conditions.
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The invention is a pyrolysis furnace for cracking heavy oils to olefins. The furnace includes a convection zone and a radiation zone. In parallel streams, the heavy stream and a stream diluent are heated in the convection zone to the point of partial thermal cracking while in the other stream a lighter oil and steam are cracked to produce olefins. The hot, olefinic light stream is then mixed with the heated heavy stream and further cracked in the radiation zone.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of, and claims priority to, U.S. patent application Ser. No. 13/453,461 filed Apr. 23, 2012 by Geoffrey Taylor and entitled ELASTICALLY STRETCHABLE FABRIC FORCE SENSOR ARRAYS AND METHODS OF MAKING; which in turn is a continuation of U.S. patent application Ser. No. 12/380,845 filed Mar. 5, 2009 by Geoffrey Taylor, and entitled ELASTICALLY STRETCHABLE FABRIC FORCE SENSOR ARRAYS AND METHOD OF MAKING.
BACKGROUND OF THE INVENTION
[0002] A. Field of the Invention
[0003] The present invention relates to transducers or sensors used to measure forces or pressures exerted on a surface.
[0004] B. Description of Background Art
[0005] Whenever a human body is supported by an object such as a chair or bed, normal and shear forces produced in reaction to the weight of the individual are transmitted from the supporting surface through the skin, adipose tissues, muscles, etc. to the skeleton. The forces exerted on body parts by support surfaces, which are equal and opposite to body weight forces, can in some cases cause damage to tissues. Forces on body parts can compress internal blood vessels and occlude nutrients from the tissue, the product of the magnitude and duration of these forces determining whether tissue damage or morbidity will occur. The areas of the human body which are most at risk of developing tissue damage such as a pressure sore are: heel, ischial tuberosities, greater trochanter, occiput and sacrum.
[0006] Some prior art sensor arrays for sensing patient pressure have suffered from disadvantages. For example, with some prior art sensors arrays, if the array is used to measure pressures exerted on a human body by a very form-fitting, conformal wheelchair seat cushion or extremely low pressure bed mattress or cushion, the array will often interfere with the function of the cushion or bed support surface, and give erroneous force measurements which are used to map the way the bed or chair supports a person. Such errors result from a “hammocking” effect, in which a flexible but not drapable sensor array deployed between fixed support positions cannot conform precisely to the shape of a patient. This effect can occur for example, using sensor arrays that use wire core sensing elements which make the arrays essentially non-stretchable. The lack of conformability of a sensor array alters the way a cushion or bed supports a patient, and also frequently results in forces or pressures exerted on individual sensors in the array being larger than a patient would actually encounter in the absence of the sensor array.
[0007] Another situation in which existing force sensor arrays for measuring and mapping forces exerted on human body parts are less than satisfactory occurs when attempting to make such measurements in a non-obtrusive, non-interfering manner on body parts which have complex shapes such as the feet.
[0008] Still further, in some prior art sensor arrays, it can be difficult to measure the resistance of sensor elements in an array using matrix addressing of the sensor elements. The difficulty results from the fact that the electrical resistances of all the non-addressed sensor elements in an array shunts the resistance of each addressed sensor element, resulting in cross-talk inaccuracies in measurements of individual sensor element resistances.
SUMMARY OF THE INVENTION
[0009] Briefly stated, the present invention comprehends novel pressure or force sensing transducers which include individual force sensing elements that are arranged in a planar array on or within a substrate consisting of a thin, flexible polymer sheet or a thin sheet of woven or non-woven fabric.
[0010] According to one embodiment of the invention, a flexible force sensing array is provided that includes an elastically stretchable sheet, a plurality of first conductive paths, a layer of sensing material, a layer of semiconductive material, and a plurality of second conductive paths. The first conductive paths are supported on the elastically stretchable sheet. The layer of sensing material is positioned in contact with the first conductive paths and the layer of sensing material has an electrical characteristic that varies in response to physical forces exerted on it. The layer of semiconductive material is positioned in contact with the layer of sensing material on a side of the layer of sensing material opposite the plurality of first conductive paths. The plurality of second conductive paths are positioned in contact with the layer of semiconductive material on a side of the layer of semiconductive material opposite the layer of sensing material.
[0011] According to another embodiment, a flexible force sensing array is provided that includes a first elastically stretchable sheet, a plurality of first conductive paths, an intermediate elastically stretchable sheet, a layer of semiconductive material, a second elastically stretchable sheet, and a plurality of second conductive paths. The plurality of first conductive paths are supported on the first elastically stretchable sheet and are parallel to each other. The intermediate elastically stretchable sheet is positioned in contact with the first elastically stretchable sheet and includes sensing material thereon that has an electrical characteristic that varies in response to applied physical forces. The layer of semiconductive material is positioned in contact with the intermediate elastically stretchable sheet to thereby form with the sensing material a PN junction. The plurality of second conductive paths are supported on the second elastically stretchable sheet and are in electrical contact with the semiconductive material. The second conductive paths are parallel to each other and transverse to the first conductive paths.
[0012] According to other embodiments, the sensing material is a piezoresistive material. The piezoresistive material may be supported by an elastically stretchable substrate. The elastically stretchable substrate may be made at least partially of nylon. The first and second elastically stretchable sheets may both be made from woven fabric. The woven fabric is nylon in one embodiment.
[0013] The semiconductive layer may be coated onto the layer of sensing material and include a metallic oxide. In some embodiments, the metallic oxide may include copper oxide.
[0014] A cover sheet may be included in some embodiments that is made from an elastically stretchable material. In some embodiments, the cover is a polyurethane or polyvinyl chloride.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a partly broken away perspective view of a basic embodiment of a three-layer piezoresistive thread pressure sensor array according to one embodiment, which uses a pair of polymer film outer substrates and a central piezoresistive layer.
[0016] FIG. 2 is a vertical transverse sectional view or end view of the sensor array of FIG. 1 taken in the direction 2 - 2 .
[0017] FIG. 3 is a partly broken-away, upper perspective view of a second, two-layer embodiment of a piezoresistive thread pressure sensor array, in which the central piezoresistive layer shown in the basic embodiment of FIGS. 1 and 2 is replaced by a piezoresistive coating on conductive threads of the sensor array.
[0018] FIG. 4 is a vertical transverse sectional or end view of the sensor array of FIG. 3 , taken in the direction 4 - 4 .
[0019] FIG. 5 is a fragmentary perspective view of a modification of the sensor array of FIGS. 1 and 3 in which adjacent pairs of more closely packed row and column conductor threads are spatially and electrically isolated from each other by non-conductive threads.
[0020] FIG. 6A is a fragmentary transverse sectional view of the sensor array of FIGS. 1 and 2 , on a further enlarged scale, showing the disposition of crossed row and column conductive threads contacting a central piezoresistive layer to form force sensing elements, with no external force applied to the elements.
[0021] FIG. 6B is a view similar to that of FIG. 6A , but with a moderate normal force applied to the sensor elements.
[0022] FIG. 6C shows the sensor elements with a larger external force applied thereto.
[0023] FIG. 7 is a graph showing electrical resistance plotted as a function of force or pressure exerted on sensor elements of the sensor arrays shown in FIGS. 1 and 3 .
[0024] FIG. 8A is a fragmentary transverse sectional view of the sensor array of FIGS. 3 and 4 on a further enlarged scale, showing the disposition of row and column piezoresistive threads to form force sensing elements, with no external force applied to the array.
[0025] FIG. 8B is a view similar to that of FIG. 8A , but with a moderate normal force applied to the sensor elements.
[0026] FIG. 8C shows the sensor element with a larger external force applied thereto.
[0027] FIG. 9 is a partly broken-away perspective view of a three-layer embodiment of a piezoresistive threads pressure sensor array, which uses a pair of fabric outer substrates and a central piezoresistive layer.
[0028] FIG. 10 is a fragmentary view of the sensor array of FIG. 9 on an enlarged scale and showing a lower plan view of an upper horizontal row conductor part of the sensor array.
[0029] FIG. 11 is a fragmentary view of the sensor array of FIG. 9 , on an enlarged scale and showing an upper plan view of a lower vertical column conductor part of the sensor array.
[0030] FIG. 12 is a vertical transverse sectional view, of the sensor array of FIG. 9 , taken in the direction 12 - 12 .
[0031] FIG. 13A is a partly broken-away, exploded upper perspective view of a fourth, two-layer piezoresistive thread pressure sensor array using fabric substrates in which the central piezoresistive layer of the embodiment shown in FIG. 9 is replaced by a piezoresistive coating on conductive threads of the sensor array.
[0032] FIG. 13B is a vertical transverse sectional view of the sensor array of FIG. 13A , taken in the direction 13 B- 13 B.
[0033] FIG. 14 is a partly broken-away upper perspective view of a fifth, single layer embodiment of a piezoresistive thread pressure sensor array which has a single fabric substrate, in which both row and column piezoresistive threads are fastened to the same side of a single insulating substrate sheet.
[0034] FIG. 15 is an upper plan view of the sensor array of FIG. 14 .
[0035] FIG. 16 is a vertical transverse sectional view of the sensor array of FIG. 14 , taken in the direction 16 - 16 .
[0036] FIG. 17 is partly broken-away, exploded upper perspective view of a modification of the fabric substrate sensor arrays of FIG. 9 , 13 or 14 in which lower column conductive threads of the sensor array are disposed in a sinuous arrangement on the fabric lower substrate panel.
[0037] FIG. 18 is an upper perspective view of another modification of the single layer fabric substrate sensor array of FIG. 14 in which both the row and column conductive threads are sinuously arranged and located on opposite sides of a piezoresistive substrate sheet.
[0038] FIG. 19 is an upper plan view of the sensor array of FIG. 18 .
[0039] FIG. 20 is a lower plan view of the sensor array of FIG. 18 .
[0040] FIG. 21 is a vertical transverse sectional view of the sensor array of FIG. 19 .
[0041] FIG. 21A is a fragmentary upper perspective view of a single layer fabric substrate sensor array in which both upper row and lower column piezoresistive threads are sinuously arranged and fastened to the same side of a single insulating substrate sheet.
[0042] FIG. 22A is a schematic diagram showing the number of conductive lead-outs required to measure the resistance of individual sensor elements in a linear array.
[0043] FIG. 22B shows sensor elements which do not have to be in a linear arrangement.
[0044] FIG. 23 is a schematic diagram showing a reduced number of lead-outs for matrix addressing an array of sensor elements arranged in a matrix array, including, but not limited to, the sensor array of FIG. 39 .
[0045] FIG. 24 is a schematic diagram showing sensor elements of the array of FIG. 23 modified to include a diode junction.
[0046] FIG. 25 is an upper perspective view of a force measuring sensor apparatus using two-layer sensor arrays of the type shown in FIG. 5 .
[0047] FIG. 26 is a block diagram showing the sensor array of FIGS. 1 and 3 interconnected with signal processing and display circuitry to comprise a force measurement system.
[0048] FIG. 27A is a perspective view of a sock incorporating the sensory array of FIG. 14-16 or 17 - 20 .
[0049] FIG. 27B is a horizontal transverse sectional view of the sock of FIG. 27A .
[0050] FIG. 28 is a typical electrical resistance-versus-normal force diagram of the sensors disclosed herein.
[0051] FIG. 29 is a partly schematic view of modifications of sensor elements of the arrays of FIG. 1 and FIG. 35 , in which sensor elements of the array have been modified to provide them with P-N, diode-type junctions.
[0052] FIG. 30 is a current-versus-voltage diagram for the sensor elements of FIG. 27 and.
[0053] FIG. 31 is an exploded perspective view of another embodiment of a force sensor array.
[0054] FIG. 32 is a perspective view of the sensor array of FIG. 31 .
[0055] FIG. 33 is an exploded perspective view of components of another embodiment of a force sensor array.
[0056] FIG. 34 is a perspective view of the sensor array of FIG. 33 .
[0057] FIG. 35 is a partly diagrammatic perspective view of a body support cushion apparatus with adaptive body force concentration minimization according to the present intention.
[0058] FIG. 36A is a fragmentary upper perspective view of the apparatus of FIG. 35 , showing a sensor array jacket of the apparatus removed from a mattress overlay cushion of the apparatus to thereby reveal individual air bladder cells of the mattress.
[0059] FIG. 36B is a fragmentary view of the mattress overlay of FIG. 36A , showing an individual air cell thereof.
[0060] FIG. 37 is a diagrammatic side elevation view of the apparatus of FIGS. 35 and 36 , showing certain bladder cells thereof deflated to reduce support forces exerted on parts of a human body supported by the mattress overlay.
[0061] FIG. 38 is a vertical sectional view of the mattress of FIG. 36 , taken in the direction of line 4 - 4 .
[0062] FIG. 39 is a fragmentary exploded perspective view of the mattress of FIG. 35 , showing elements of a force sensor arrangement thereof.
[0063] FIG. 40 is a diagrammatic view showing an exemplary relationship between the dimensions of adjacent air bladder cells and the width of an insulating strip between conductors of sensors on the cells.
[0064] FIG. 41 is a block diagram of electro-pneumatic controller elements of the apparatus of FIG. 35 .
[0065] FIG. 42 is a simplified perspective view of the electro-pneumatic controller of FIG. 41 .
[0066] FIG. 43 is a flow chart showing operation of the apparatus of FIG. 35 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0067] FIGS. 1-43 illustrate various aspects of elastically stretchable, conformable fabric force sensor arrays, and methods for making the arrays, according to the present invention.
[0068] Referring first to FIGS. 1 and 2 , a first, basic, three-layer embodiment of a force sensor array is shown.
[0069] As shown in FIGS. 1 and 2 , a three-layer force sensor array 30 includes a plurality m of elongated, straight thin conductive row threads 31 - 1 through 31 - m and a plurality n of elongated, straight thin, conductive column threads 32 - 1 through 32 - n.
[0070] The electrically conductive row threads 31 and column threads 32 consist of an elastically stretchable monofilament or woven polymer core 31 C, 32 C, which has been treated to make the threads electrically conductive, as by silver plating the core to form coatings 31 P, 32 P on cores 31 C, 32 C, respectively.
[0071] One type of example embodiment of a sensor array 30 used row and column conductive threads 31 , 32 made from silver plated nylon thread, 117/17 2 ply, catalog #A264, obtained from LESS EMF, 809 Madison Avenue, Albany, N.Y. 12208, USA. That conductive thread had a lineal resistivity of about 75 ohms per foot, and an elastic stretchability of about 1 percent, i.e., at least 10 times greater than that of a stainless steel wire of a similar diameter.
[0072] A second type of example embodiment of a sensor array uses row and column conductive threads made from silver plated stretchy nylon yarn, that plated yarn having the designation Shieldex, ®Lycra dtex 20, obtained from W. Zimmerman, GmbH & Co. K6, Riederstrasse 7, D-88171, Weiter-Simmerberg, Germany. That conductive thread had a lineal resistivity of about 500 ohms per foot. The elastic stretchability of that conductive yarn is greater than 30 percent, i.e., at least 300 times greater than that of a stainless steel wire of a similar diameter.
[0073] As shown in FIGS. 1 and 2 , a row threads 31 and column threads 32 lie in parallel planes but are inclined with respect to one another, such as at an angle of ninety-degrees. In the example embodiment 30 , row conductive threads 31 are fastened to the lower surface 34 on an upper substrate sheet 33 , and column conductive threads 32 are fastened to the upper surface 36 of a lower substrate sheet 35 .
[0074] As may be seen best by referring to FIG. 2 , sensor array 30 includes a thin central lamination or sheet 37 made of a piezoresistive material. As shown in FIG. 2 , opposed inner facing outer surfaces 38 , 39 of row and column conductive threads tangentially contact upper and lower surfaces 40 , 41 , respectively, of central piezoresistive sheet 37 . Thus, as shown in FIGS. 1 and 2 , each crossing point or intersection of a row conductive thread 31 and a column conductive thread 32 forms a piezoresistive sensor element 48 which consists of a small portion of central piezoresistive sheet 37 that is electrically conductively contacted by a row conductive thread and a column conductive thread.
[0075] In example embodiments of sensor array 32 , piezoresistive sheet 37 was fabricated by coating a stretchy, i.e., elastically stretchable thin Lycra-like fabric sheet with a piezoresistive material. A suitable fabric sheet, which forms a matrix for supporting the piezoresistive material, was a fabric known by the trade name Platinum, Milliken, Style #247579, obtained from the manufacturer, Milliken & Company, Spartenburg, S.C., USA. That fabric had a fiber content of 69 percent nylon and 31 percent Spandex, a thread count of about 88 threads per inch, and a thickness of 0.010 inch.
[0076] The piezoresistive material used to coat the fabric matrix is made as follows:
[0077] A solution of graphite, carbon powder, nickel powder and acrylic binder are mixed in proportions as required to obtain the desired resistance and piezoresistive properties. Silver coated nickel flake is used to achieve force response in the low force range of 0 to 1 psi, graphite is used for the mid range of 1 to 5 psi and Charcoal Lamp Black is used for high force range of 5 to 1000 psi. Following is a description of the substances which are constituents of the piezoresistive material:
[0078] Silver Coated Nickel Flake:
Platelets approximately one micron thick and 5 microns in diameter. Screen Analysis (−325 Mesh) 95%. Apparent Density 2.8. Microtrac d50/microns 12-17. Available from: Novamet Specialty Products Corporation,
681 Lawlins Road, Wyckoff, N.J. 07481
[0085] Graphite Powder:
Synthetic graphite, AC-4722T Available from: Anachemia Science
4-214 De Baets Street Winnipeg, MB R2J 3W6
[0090] Charcoal Lamp Black Powder:
Anachemia Part number AC-2155 Available from: Anachemia Science
4-214 De Baets Street Winnipeg, MB R2J 3W6
[0095] Acrylic Binder:
Staticide Acrylic High Performance Floor Finish P/N 4000-1 Ph 8.4 to 9.0 Available from: Static Specialties Co. Ltd.
1371-4 Church Street Bohemia, N.Y. 11716
[0101] Following are examples of mixtures used to make piezoresistive materials having different sensitivities:
[0102] Example I for forces in the range of 0 to 30 psi:
200 ml of acrylic binder 10 ml of nickel flake powder 10 ml of graphite powder 20 ml of carbon black
[0107] Example II for forces in the range of 0-100 psi
200 ml of acrylic binder 5 ml of nickel flake powder 5 ml of graphite powder 30 ml of carbon black
[0112] Example III for forces in the range of 0-1000 psi
200 ml of acrylic binder 1 ml of nickel flake powder 1 ml of graphite powder 40 ml of carbon black
[0117] The fabric matrix for piezoresistive sheet 37 is submerged in the piezoresistive coating mixture. Excess material is rolled off and the sheet is hung and allowed to air dry.
[0118] Upper and lower substrate sheets 33 , 34 are made of a thin, flexible insulating material, such as 0.002 inch thick polyurethane or polyvinyl chloride (PVC). In one embodimenty, the substrate sheets 33 , 34 are made of an elastomeric material which has a relatively high degree of elastic stretchability, so that sensor array 30 is readily stretchable and conformable to the surface of an irregularly-shaped object. It can be appreciated, however, that conductive threads 31 , 32 should also be elastically stretchable to facilitate stretchability of sensor array 30 . This is because conductive threads 31 , 32 are affixed to substrate sheet 33 , 34 , respectively, by, for example, blobs of adhesive 42 , as shown in FIG. 2 . Piezoresistive sheet 37 is also fixed to upper and lower substrate sheets 33 , 34 by blobs of glue 42 .
[0119] FIGS. 6A-6C illustrate how the arrangement of row and column conductive threads 31 , 32 , in combination with central piezoresistive layer 37 of sensor array 30 shown in FIGS. 1 and 2 , form individual force sensing elements 48 . Each force sensor element 48 is located at the cross-over or intersection point 49 of a row conductive thread, e.g., 31 - 1 , 31 - 2 , . . . 31 - m , with a column conductive thread, e.g., 32 - 1 , 32 - 2 , . . . 32 - n , for a MXN matrix of sensor elements. Thus, individual sensor elements may be identified by the nomenclature 48-XXX-YYY, where XXX denotes row number and YYY denotes column number.
[0120] As shown in FIGS. 2 and 6A , with no external force applied to sensor array 30 , at each cross-over point 49 of a row conductive thread 31 and a column conductive thread 32 of sensor array 30 , there is an upper electrically conductive tangential contact region 43 between central piezoresistive layer 37 and the upper conductive row thread, and a lower electrically conductive tangential contact region 44 between the piezoresistive layer and the lower, column conductive thread.
[0121] With no external force applied to sensor array 30 , the electrical resistance between a row conductive thread 31 and column conductive thread 32 , which consists of the series resistance of upper contact region 43 , lower contact region 44 , and the effective resistance of piezoresistive material 45 of piezoresistive layer 37 between the upper and lower contact regions is relatively high. The relatively high resistance results from the fact that in this case, tangential contact regions 43 and 44 are relatively small, and the thickness of uncompressed piezoresistive volume 45 is at its maximum value. However, as shown in FIGS. 6B and 6C , when sensor array 30 is placed on a supporting surface S and a normal force N of increasing magnitude is applied to upper surface 47 of the sensor array 30 , the electrical resistance between a row conductive thread 31 and a column conductive thread 32 decreases, as will now be described.
[0122] Referring still to FIGS. 2 and 6A , it may be seen that with no external force applied to sensor array 30 , tangential contact regions 43 , 44 between row and column conductive threads 31 , 32 and central piezoresistive layer 37 are relatively small, since the threads have a circular outer cross-sectional shape, which tangentially contacts flat planar surfaces of the piezoresistive layer. Under these circumstances, the small sizes of contact regions 43 , 44 results in relatively high electrical resistance between central piezoresistive layer 37 and row and column conductive threads 31 , 32 . Moreover, with central piezoresistive layer 37 uncompressed, its thickness and hence resistance are at a maximum value.
[0123] FIGS. 6B and 6C illustrate the effects of increasing external normal forces or pressures exerted on sensor array 30 . As shown in FIGS. 6B and 6C , sensor array 30 is placed with its lower surface 46 supported on a surface S and a force N is exerted perpendicularly downwards on upper surface 47 of the array, resulting in a reaction force U being exerted upwardly by supporting surface S on lower surface 46 of the array. Since central piezoresistive layer 37 is resiliently deformable, the compressive force on it decreases the thickness T of the part of the layer between a row conductive thread 31 and a column conductive thread 32 . This reduction in path length through piezoresistive layer 37 between a row conductive thread 31 and a column conductive thread 32 causes the electrical resistance R between the threads to decrease in value.
[0124] For moderate values of normal force N, as shown in FIG. 6B , resilient deformation of central piezoresistive layer 37 is relatively small, resulting in a relative small reduction in electrical resistance R between the threads. Larger forces N exerted on sensor array 30 cause a larger deformation of the central piezoresistive layer, as shown in FIG. 6C , resulting in a larger percentage reduction in resistance R. FIG. 7 illustrates in a general way the reduction in electrical resistance measurable between a row conductive thread 31 and a column conductive thread 32 , as a function of normal force or pressure exerted on array 30 at these points.
[0125] FIGS. 3 and 4 illustrate another embodiment 50 of a piezoresistive thread pressure sensor array in which the central piezoresistive layer shown in FIGS. 1 and 2 and described above is replaced by a piezoresistive coating on either, or both, row conductive threads 51 and column conductive threads 52 .
[0126] Sensor array 50 is facially similar to sensor array 20 disclosed and shown in FIGS. 1 and 2 of U.S. Pat. No. 6,543,299, but differs from that sensor array in important ways. Thus, row and column piezoresistive threads 51 , 52 of sensor array 50 are made of elastically stretchable polymer cores 51 C, 52 C which have been treated by silver plating the cores to form on the threads electrically conductive coatings 51 P, 52 P, respectively. The coatings on either or both cores 51 C, 52 C are clad with a layer 51 R, 52 R, respectively, of a material which has a piezoresistive characteristic. The piezoresistive material used to form cladding layers 51 R, 52 R on plated surfaces 51 P, 52 P of cores 51 C, 52 C, of piezoresistive conductive threads 51 , 52 may have a composition similar to that described above for making piezoresistive sheet layer 37 .
[0127] A method for making piezoresistive sensor threads by cladding conductive threads with a layer of a piezoresistive material includes preparing a slurry of piezoresistive material having a composition described in examples 1, 2 and 3 above. A highly conductive polymer thread, such as silver plated nylon thread 117/17 2 ply, Cat#124 available from LESS EMF Inc., 804 Madison Avenue, Albany, N.Y. 12208, is then immersed in a container holding the slurry, for a period of about 10 seconds. The end of a thread which has been immersed is withdrawn from the container, and while it is still wet, drawn through a circular aperture through a scraper plate.
[0128] In an example embodiment, a conductive thread having a core diameter of 0.25 mm and wet-coated diameter in the range of about 0.4 mm to 0.5 mm was drawn through a #360 scraper having a diameter of 0.45 mm, thus resulting in a wet scraped diameter of about 0.45 mm. The scraped thread was then fed through a stream of air heated to a temperature of 70 degrees C. at a linear travel speed of 100 mm/minute for a period of 5 minutes, to thus form a solidified coating having a diameter of about 0.4 mm.
[0129] As shown in FIGS. 3 and 4 , piezoresistive row and column threads 51 , 52 are fastened to upper and lower substrate sheets 63 , 65 , by suitable means such as adhesive blobs 74 . Substrate sheets 63 , 64 are made of a thin, flexible material such as 0.003 inch thick elastomeric polyurethane or polyvinyl chloride (PVC) that has a relatively high degree of elasticity.
[0130] FIGS. 3 and 8 A- 8 C illustrate how the arrangement of row and column piezoresistive threads 51 , 52 of sensor array 50 form individual force sensing elements 69 . In response to progressively larger compressive normal forces, piezoresistive cladding layers 51 R, 52 R on row and column conductive core threads 51 C, 52 C are progressively compressed into oval cross-sectional shapes of smaller diameter. Thus, as shown in FIGS. 8A-8C , the electrical resistance of each sensor element 70 decreases in inverse proportion to applied pressure, as shown in FIG. 7 .
[0131] FIG. 5 illustrates a modification 70 of the sensor arrays shown in FIGS. 1 and 3 and described above. Modified sensor array 70 may alternatively employ the three-layer construction of sensor array 30 shown in FIG. 1 , or the two-layer construction of sensor array 50 shown in FIG. 3 . The modification consists of fabricating sensor array 70 with electrically insulating material between adjacent rows and/or columns of conductive threads. Thus, for example, the modification 70 of two-layer sensor 50 shown in FIG. 3 includes elongated insulating threads 71 , made for example of 0.012 inch diameter polyester disposed between each pair of adjacent row conductive threads 51 and each pair of adjacent column conductive threads 52 .
[0132] The insulating threads 71 are secured in place by any suitable means, such as adhesively bonding the threads to substrate sheets 63 , 65 (see FIGS. 2 and 4 ). This constructing enables sensor array 70 to be substantially wrinkled or otherwise deformed to conform to an irregularly shaped surface, without the possibility of pairs adjacent row or column conductive threads 51 or 52 contacting one another to thus cause an electrical short circuit which would result in erroneous sensor element resistance measurements and force determinations. Optionally, insulation between adjacent pairs of row and column conductive threads could be applied by lightly spraying an aerosol insulation acrylic paint to hold the conductive threads in place.
[0133] FIGS. 9-12 illustrate a three-layer embodiment 80 of a piezoresistive thread force sensor array. Sensor array 80 is similar to the basic embodiment 30 of sensor array shown in FIGS. 1-2 and described above. However, sensor array 80 uses upper and lower substrate sheets 83 , 85 which are made of woven fabric rather than polymer films. This construction, in conjunction with the use of stretchy conductive row and column threads 81 , 82 made of plated nylon or Lycra cores, results in a sensor array that is even more flexible, elastically stretchable and drapable than sensor array 30 .
[0134] As may be seen best by referring to FIG. 10 , sensor array 80 includes a plurality of parallel, laterally spaced apart conductive row threads 81 which are fastened to the lower surface 84 of upper fabric substrate sheet 83 . The row conductive threads 81 are fastened to lower surface 84 of upper substrate sheet 83 by any suitable means. In one embodiment, as shown in FIG. 10 , each row conductive thread 81 is fastened to a substrate sheet by sewing the thread to fabric substrate sheet 83 by a smaller diameter, non-conductive thread 90 arranged in an elongated zig-zag stitching pattern. In an example embodiment, threads 90 consisted of 0.005-0.010 inch diameter, 100% polyester woven thread. For greater strength required for sensor arrays used to measure larger forces, threads 90 may optionally be monofilaments.
[0135] In an example embodiment of a sensor array 80 , upper and lower substrate sheets 83 , 85 were made from a light-weight, elastically stretchable fabric, both of the two following fabrics were tested and found suitable for substrate sheets 83 , 85 . (1) Milliken “Mil/glass” brand, Style #247579, composed of 69% nylon, 31% spandex, and having a weight of 1.8 oz./sq. yd. (2) Milliken “Interlude” brand, product #247211, composed of 82% nylon, 18% Lycra, and having a weight of 3.2-3.4 oz. Per sq. yd. Both of the foregoing fabrics are available from Milliken & Company, 23 Fiddler's Way, Lafayette, N.J. 07848.
[0136] As shown in FIG. 11 , lower column conductive threads 82 are fastened to the upper surface 86 of lower fabric substrate sheet 85 by non-conductive threads 91 of the same type as non-conductive threads 90 and in the same zig-zag stitching manner.
[0137] As shown in FIGS. 9 and 12 , three-layer fabric substrate sensor array 80 includes a central piezoresistive sheet 87 , which may have a composition and construction similar to that of central piezoresistive sheet 37 of sensor array 30 described above.
[0138] As may be seen best by referring to FIG. 13B , upper, row piezoresistive threads 101 are attached to lower surface 114 of upper fabric substrate sheet 113 by insulating sewn threads 90 arranged in zig-zag stitches. Similarly, lower, column piezoresistive threads 102 are attached to the upper surface 116 of lower substrate sheet 115 by sewn threads 91 arranged in zig-zag stitches.
[0139] FIGS. 13A and 13B illustrate another two-layer embodiment 100 of a piezoresistive thread force sensor array. Sensor array 100 is similar to sensor array 80 . However, in sensor array 100 , conductive row and column threads 81 , 82 are replaced by piezoresistive threads 101 , 102 which have the same characteristics as piezoresistive threads 51 , 52 of the two-layer polymer film substrate sensor array 50 shown in FIGS. 3 and 4 and described above. This construction eliminates the requirement for the central piezoresistive sheet 87 of three-layer fabric sensor array 80 described above.
[0140] FIGS. 14-16 illustrate a fifth, single layer embodiment 120 of a force sensor array in which row and column piezoresistive threads are attached to a single side of a single insulating fabric substrate sheet 127 .
[0141] As shown in FIGS. 14-16 , single layer fabric force sensor array 120 has a single substrate sheet 127 which is made from a light-weight, elastically stretchable fabric. Both of the two following fabric were listed and found suitable for making substrate sheet 127 . (1) Milliken “Millglass” brand, Style #247579, composed of 69% nylon, 31% spandex, and having a weight of 1.8 oz./sq. yd., and (2) Milliken “Interlude” brand, product #247211, composed of 82% nylon, 18% Lycra, and having a weight of 3.2-3.4 oz. Per sq. yd. Both of the foregoing fabrics are available from Milliken & Company.
[0142] A plurality of parallel, laterally spaced apart column piezoresistive threads 122 are fastened to the upper surface 130 of the substrate sheet. The column piezoresistive threads are made from silver-plated nylon thread, Catalog #A-264 obtained from LESS EMF, or from silver-plated stretchy nylon yarn, both of which are described in detail above in conjunction with the description of sensor array 30 .
[0143] In one embodiment of single fabric substrate sheet sensor array 120 , each column piezoresistive thread 122 is fastened to substrate sheet 127 by a smaller diameter, non-conductive thread 91 arranged in an elongated zig-zag stitching pattern. In an example embodiment, threads 91 consisted of 0.005-0.010 diameter, 100% polyester.
[0144] As shown in FIGS. 14 , 15 and 16 , sensor array 120 includes a plurality of parallel, laterally spaced apart piezoresistive row threads 121 which are also fastened to the upper surface 130 of substrate sheet 127 . As shown in FIG. 16 , m row piezoresistive threads 121 are fastened to substrate sheet 127 by non-conductive threads 90 of the same type as threads 91 and in the same zig-zag stitching manner.
[0145] As shown in FIG. 16 , opposed inner facing outer surface 128 , 129 of row and column piezoresistive threads 121 , 122 tangentially contact each other. Thus, as shown in FIGS. 14-16 , each crossing of a row piezoresistive thread 121 with a column piezoresistive thread 122 forms a piezoresistive sensor element 138 which consists of a small portion of piezoresistive coatings of a row and column piezoresistive thread tangentially contacting one another.
[0146] FIG. 17 illustrates a modification of the force sensor arrays using fabric substrate sheets shown in FIG. 9 , 13 or 14 and described above. As shown in FIG. 17 , a lower fabric substrate sheet 145 of modified force sensor array 140 has attached thereto lower, column conductive piezoresistive threads 142 which are sinuously curved with respect to parallel straight base lines between opposite ends of each thread, rather than lying directly on the base lines, as are the column conductive threads 82 of sensor array 80 shown in FIG. 11 . With this arrangement, lower fabric substrate sheet 145 is even more readily elastically stretchable in directions parallel to the column thread base lines because longitudinally spaced apart points on the fabric substrate sheet are not constrained to be at maximum lengths by the less elastically stretchable conductive threads. Thus, the stretchability of the column substrate sheet 145 is limited only by its intrinsic stretchability since the arrangement of column conductive threads 142 allows them to conform readily to size of the substrate sheet by changing spacing between peaks and valleys of the sinuously curved conductive threads, i.e., altering the spatial wavelengths of the sinuous curves formed by threads.
[0147] Optionally, upper row piezoresistive threads 141 may also be sinuously arranged in the same manner as lower column piezoresistive threads shown in FIG. 17 , to thus enhance elastic compliance, or stretchability, of sensor array 140 is in directions parallel to the row conductive threads as well as in directions parallel to the column piezoresistive threads. Also, either or both row and column conductive threads of three-layer sensor arrays such as those of the type shown in FIG. 1 may be sinuously arranged to provide enhanced uniaxial or biaxial stretchability.
[0148] FIGS. 18-21 illustrate another modification 180 of the single fabric substrate sheet sensor array 120 of FIG. 14 . Sensor array 180 has upper, row conductive threads 181 and lower, column conductive threads 182 which are both sinuously arranged on opposite sides of a fabric piezoresistive central substrate sheet 187 . This construction gives array 180 greater elasticity in directions parallel to the column conductive threads 182 as well as in directions parallel to row conductive threads 181 .
[0149] FIG. 21A illustrates another modification 200 , which row and column piezoresistive threads 201 , 202 are both sinuously arranged and attached to the upper surface 211 of an insulating substrate sheet 210 , in the manner shown in FIG. 16 .
[0150] FIG. 22A illustrates the number of conductive leads required to measure the resistance of individual elements of a linear array of sensor elements, to thus determine numerical values of force or pressure exerted on each sensor element. As shown in FIG. 22A a single common lead-out conductor C is connected to a linear array of intersecting lead-out conductors Li through Ln to form a plurality of sensor elements SI through Sn, by piezoresistive material at each intersection point. Thus, for a total of n sensors S, there are required a total R equal to n+1 lead-out conductors to measure the individual resistance of each sensor element SI through Sn and hence determine the forces F 1 through Fn exerted on each individual sensor element.
[0151] FIG. 22B shows a plurality of sensor elements Sn+1, Sn+2, Sn+3 which are not necessarily arranged in a linear array, being located, for example, on individual finger tips. As shown in FIG. 22B , n+1 lead-out conductors are also required for this configuration.
[0152] FIG. 7 illustrates the electrical resistance of a one-inch square piezoresistive force sensor element 48 using a piezoresistive sheet 37 having the formulation listed for an example sensor array 30 shown in FIGS. 1 and 2 , and fabricated as described above, as a function of normal force or pressure exerted on the upper surface 47 of upper substrate sheet 33 of sensor array 30 . As shown in FIG. 7 , the resistance varies inversely as a function of normal force.
[0153] As shown in FIG. 1 , row conductive threads 31 - 1 through 31 - m , in vertical alignment with column conductive threads 32 - 1 through 32 - n form with piezoresistive layer sheet 37 between the column and row conductive threads a mXn rectangular matrix array of m×n force elements 48 .
[0154] If upper and lower electrical connections to each sensor element 48 were electrically isolated from connections to each other sensor element, a separate pair of lead-out conductors for each of the sensors, would be required, i.e., a total of 2Qlead-out conductors for Q sensor elements or, if a single common electrode lead-out were employed as shown in FIG. 22 , a total of Q+1 lead-outs would be required.
[0155] As shown in FIG. 1 , sensor array 30 is arranged into a matrix of m rows and n columns, thus requiring only R=m×n lead-out conductors. However, as shown in FIG. 23 , if matrix addressing of sensor array 30 is used to measure the resistance of individual sensors 48 to thereby determine normal forces exerted on the sensors, there is a substantial cross-talk between the resistance on an addressed sensor 48 and non-selected sensors because of parallel current paths to non-addressed sensors. To overcome this cross-talk problem, the present inventor has developed a method for modifying sensors 48 to give them a diode-like characteristic. As may be confirmed by referring to FIG. 24 , the cross-talk between sensor elements 40 which have a non-bilateral, polarity-sensitive transfer function, mitigates the cross-talk problem present in the matrix of symmetrically conductive sensors 48 shown in FIG. 23 .
[0156] Sensor elements 48 are modified to have a diode-like characteristic by modifying the preparation of piezoresistive layer sheet 37 , as follows: First, a piezoresistive layer sheet 37 is prepared by the process described above. Then, either the upper surface 40 or the lower surface 41 of the piezoresistive coating 37 A of piezoresistive sheet 37 is modified to form thereon a P-N, semiconductor-type junction.
[0157] Modification of piezoresistive coating 37 A to form a P-N junction is performed by first preparing a slurry which has the composition of one of the three example mixtures described above, but modified by the addition of 5 ml each of copper oxide (CuO) in the form of a fine powder of 50-micron size particles, and 5 ml of cuprous oxide (Cu 2 O) in the form of a fine powder of 50-micron size particles and thoroughly stir-mixing the foregoing ingredients. The resultant solution is then reduced using about 30 mg of solution of sodium borohydride, also known as sodium tetrahydroborate (NaBH 4 ) or ammonium phosphate, to form a solution having a pH of about 5.5. The solution is then coated onto the upper surface 40 or lower surface 41 of piezoresistive coating 37 B on piezoresistive sheet 37 . This coating process is performed using a roller coating process which results in about 0.5 ml of solution per square centimeters being applied. The surface coating is then allowed to air-dry at room temperature and a relative humidity of less than 20%, for 4 hours. After the coated surface has dried, it functions as a P-type semiconductor, while the uncoated side of coating 37 B functions as an N-type semiconductor of P-N junction diode.
[0158] FIG. 29 illustrates a sensor element 48 which has been prepared as described above to give the sensor a diode-like characteristic, and a circuit for obtaining the I-V (current versus voltage) transfer function of the sensor. FIG. 30 shows a typical I-V curve for sensor elements 48 of FIG. 29 .
[0159] As stated above, the advantage of modifying sensor elements 48 of sensor array 30 by adding a semi-conductive layer that acts like a diode is that it reduces cross talk between sensors. As is shown in FIG. 23 , this cross-talk occurs because of the so-called “completing the square” phenomenon, in which three connections are made in a square matrix array of three non-addressed resistors that form the three corners of a square. Thus, any two connections in a vertical column and a third one in the same row function as either connection in an X-Y array of conductors. The resistor at the fourth corner of the square shows up as a phantom in parallel with an addressed resistor because the current can travel backwards through that resistor, and forward through the other resistors. Care and additional expense must be taken in the electronics to eliminate the contribution of this phantom. For example, if, as is shown in FIG. 23 , a potential V is applied between row and column conductors X 1 Y 1 , to thereby determine the resistance of piezoresistive sensor resistance R 11 , reverse current flow through “phantom” resistor R 22 would cause the sum of resistances R 12 +R 22 +R 22 to shunt R 11 , resulting in the parallel current flow paths indicated by arrows in FIG. 23 , which in turn would result in the following incorrect value of resistance:
[0160] R x1 y 1 =R 11 //(R 12 +[R 22 ]+R 21 ), R x1 Y 1 =R 11 (R 12 +[R 22 ]+R 21 )/(R 11 +R 12 +[R 22 ]+R 21 ), where brackets around a resistance value indicate current flow in a counterclockwise direction through that resistor, rather than clockwise, i.e., diagonally downwards towards the left. Thus, for example, if each of the four resistances listed above had a value of 10 ohms, the measured value of R 11 would be:
[0161] R 11 =10(10+10+10)/(10+10+10+10)=300/40=7.5 ohms, i.e., 25% below the actual value, 10 ohms, of R 11 . If the resistance values of R 12 , R 22 and R 21 of the three non-addressed piezoresistive sensor element 48 were each lower, e.g., 1 ohm, because of greater forces concentrated on those sensor elements 48 , the measured value of R 11 would be:
[0162] R 11 =10(1+1+1)/(10+1+1+1)=30/13=2.31 ohms, i.e., a value of about 77 percent below the actual value of R 11 .
[0163] On the other hand, by placing a diode in series with each piezoresistive sensor element 48 , as shown in FIG. 24 , the electrical resistance of an element measured in a reverse, counterclockwise direction a test current flow through the sensor element, e.g., R 22 , would be for practical purposes arbitrarily large, or infinity compared to the clockwise forward paths of current through the other resistances shown in FIGS. 23 and 24 . In this case, the measured resistance value for a 2×2 matrix of four resistances each having a value of 10 ohms would be:
[0164] R X1 Y 1 =10(1+∞+1)/(10+1+∞+1)=10 ohms, the correct value. Thus, modifying each sensor element 48 to include a p-n junction thereby give the sensor element a diode-like characteristic electrically isolates, i.e., prevents backward current flow, through each sensor element 48 . This enables the correct value of electrical resistance of each sensor element 48 and hence forces exerted thereon to be measured accurately R X1 y 1 using row and column matrix addressing rather than requiring a separate pair of conductors for each sensor element.
[0165] FIG. 25 illustrates a force measuring apparatus 150 . The apparatus 150 may use any of the types of sensor arrays described above, but in a particular example shown in FIG. 25 uses a sensor array 70 of the type shown in FIG. 5 .
[0166] As shown in FIG. 25 , force measuring apparatus 150 used four sensor arrays 70 - 1 , 70 - 2 , 70 - 3 and 70 - 4 , each having a matrix of 16 row conductive threads by 16 column conductive threads. The four arrays are arranged in a square matrix, to thus form a composite sensor array 70 -C consisting of 32 rows×32 columns of conductive threads having formed at their intersection 32×32=1,024 sensor elements 88 . As shown in FIG. 25 , each of the 32 row conductive thread lead-out wires and each of the 32 column conductive thread lead-outs is connected to a separate electrically conductive connector pin of a plurality of connector pins 154 - 1 through 154 - 64 of a pair of electrical interface connectors 153 - 1 , 153 - 2 .
[0167] FIG. 26 illustrates a force measurement system 160 which utilizes the force sensor apparatus 150 described above.
[0168] As shown in FIG. 26 , force measurement system 160 includes a computer 161 which is bidirectionally coupled to force sensor array 70 of force sensor apparatus 160 through a force sensor interface module 162 . The sensor interface module 162 includes a Digital-to analog Converter (DAC) 163 for generating in response to control signals from computer 161 test voltages or currents which are directed to matrix-addressed individual force sensors 88 .
[0169] As shown in FIG. 26 , individual force sensor elements 88 are addressed by connecting one terminal of a current or voltage source controlled by DAC 163 to a selected one of X-row conductors 51 - 1 - 51 - m by an X multiplexer 164 , and connecting the other terminal of the source to a selected one of Y-column conductors 52 - 1 - 52 - m by a Y multiplexer 165 . Sensor interface module 162 also included an Analog-to-Digital Converter (ADC) 166 which measures the voltage drop or current through a sensor element 88 resulting from application of a test current or voltage, and inputs the measured value to computer 161 . Using predetermined scale factors, computer 161 calculates the instantaneous value of electrical resistance of a selected addressed sensor element 88 , and from that resistance value, a corresponding normal force instantaneously exerted on the addressed sensor.
[0170] In response to control signals cyclically issued by computer 161 , X multiplexer 164 and Y multiplexer 165 are used to cyclically measure the resistance of each force sensor element 88 , at a relatively rapid rate of, for example, 3,000 samples per second, enabling computer 161 to calculate the force exerted on each force sensor element 88 at that sampling rate.
[0171] Measurement system 160 includes an operator interface block 167 which enables values of force or pressures measured by sensor elements 88 to be displayed as numerical values and/or a graph or pressure/force map on the display screen of a computer monitor 168 , or outputted to a peripheral device such as a printer, or a network such as the internet, through an I/O block 169 .
[0172] FIGS. 27A and 27B illustrate a sock 170 which includes one of the novel sensor arrays employing conductive threads which were described above, such as the single layer, fabric substrate piezoresistive thread sensor array shown in FIG. 14-16 or 17 - 20 .
[0173] As shown in FIG. 17 , sock 170 which includes a single layer fabric force sensor array 180 that is a modification of the planar force sensor array 120 shown in FIGS. 14-16 and described above. The modification of force sensor array 120 to form force sensor array 180 may be best visualized by considering that the left and right side edges of the array 120 are brought upwards from the plane of the page to meet and form a hollow cylindrical tube.
[0174] Row conductor threads protruding 121 from the aligned edges of the array are then electrically conductively fastened to a first, row conductor ribbon cable 181 . Column conductive threads protruding from one edge of the rolled-up array are electrically conductively fastened to a second, column conductor ribbon cable 182 . Outer ends 183 , 184 who protrude from an edge of array 120 are electrically connected to a resistance measuring circuit as shown in FIG. 26 and described above.
[0175] FIGS. 31-34 illustrate modifications of fabric substrate force sensor arrays using conductive threads, in which the conductive threads are fixed to a fabric substrate sheet without the use of sewn stitching by adhesive applied directly to a conductive thread. Thus, a first, three-layer fabric sensor array 190 includes a plurality of parallel, spaced apart row conductive elastic threads 191 which are adhesively bonded to the lower surface 194 of an upper stretchable fabric substrate sheet 193 made of 3 mil thick polyester or either of the two Milliken fabrics described above. Sensor array 190 also includes a plurality of parallel spaced apart column conductive elastic threads 192 which are adhesively bonded to an upper surface 196 of a lower stretchable fabric substrate sheet 195 . A thin sheet of stretchable fabric prepared to give it a piezoresistive property in the manner described above comprises a central piezoresistive layer 197 which is positioned between row and column conductive threads 191 , 192 . The foregoing three layers are then stacked on top of one another and dots of glue injected through the mesh openings of the fabric substrate of all three layers to adhere them together and thus form a completed sensor array 190 .
[0176] Sensor array 200 , shown in FIG. 33 , utilizes a single substrate sheet 207 . Conductive row and column threads 191 , 192 , separated by insulating threads 210 , 211 , are adhered to upper surface 212 and lower surface 213 of sheet 207 by double-stick tape strips 213 , 214 .
[0177] FIGS. 35-43 illustrate various aspects of a method and apparatus for minimizing body force concentrations on a human body using an adaptive cushion. The example embodiment depicted in FIGS. 35 and 37 includes an adaptive cushion which is of an appropriate size and shape for use on a standard single or hospital bed. However, as will be clear from the ensuing description of that example embodiment, the size and shape of the adaptive cushion can be varied to suit different applications, such as for use on a fixed chair or wheel chair.
[0178] Referring first to FIGS. 35 and 36A , an adaptive cushion apparatus 420 for minimum body force concentrations on a body of a person lying on a bed may be seen to include a longitudinally elongated, rectangular cushion overlay 421 . Cushion 421 has an appropriate size and shape to fit conformally on top of a standard size hospital bed. Thus, an example embodiment of cushion 421 had a laterally elongated, rectangular shape with a length of about 6 feet, a width of about 3 feet, and a thickness of about 4 inches.
[0179] The six panels of each air bladder cell 423 are sealingly joined at edges thereof to form a hermetically sealed body which has a hollow interior space 422 A.
[0180] As shown in FIG. 36A , mattress overlay cushion 421 is constructed as a rectangular, two-column by six-row array of 12 individual inflatable air bladder cells 422 . Each air bladder cell 422 has a laterally elongated, rectangular shape, having a length of about 18 inches, a depth of about 17 inches, and a thickness of about 4 inches. As shown in FIGS. 35 and 36 , bladders 422 are arranged in left and right columns, each having 6 longitudinally spaced apart, laterally disposed, laterally elongated bladders. As shown in FIGS. 36 and 38 , each air bladder cell has a flat base panel 423 , left and right end panels 424 , 425 , head and toe or front and rear panels 426 , 427 , and an upper panel 428 . The bladders 422 are made of a thin sheet of a flexible, elastomeric material such as neoprene rubber or polyurethane, having a thickness of about 0.014 inch. The six panels of each air bladder cell 422 are sealingly joined at edges thereof to form a hermetically sealed body which has a hollow interior space 422 A. Optionally, each air bladder cell 422 may be fabricated from a tubular preform in which each end panel is sealingly joined to opposite transverse ends of the tubular preform. In either embodiment, adjacent panels of an individual air bladder cell are sealingly joined by a suitable method such as ultrasonic bonding, RF-welding or adhesive bonding.
[0181] The number, size, shape, relative positioning and spacing of air bladder cells 422 of mattress cushion overlay 421 are not believed to be critical. However, it is believed preferable to arrange mattress overlay 421 into symmetrically-shaped left and right columns each having at least five and preferably six longitudinal zones corresponding to major curvature of a longitudinally disposed medial section of a typical human body. Thus, as shown in FIGS. 35 , 36 A and 37 , mattress overlay cushion 421 has a left-hand column of six air bladder cells 422 L 1 - 422 L 6 , and a right-hand column of six cells 421 R 1 - 421 R 6 .
[0182] As shown in FIGS. 38 and 40 , the bladders are stacked closely together in both front and rear and side by side directions, with minimum longitudinal and lateral spacings 429 , 430 , respectively, that are vanishingly small so that adjacent bladder cells physically contact each other.
[0183] As indicated in FIGS. 35 and 36 , each bladder cell 422 is provided with a tubular air inlet port 431 which protrudes through a side wall, e.g., a left or right side wall 424 or 425 , and communicates with a hollow interior space 422 A within the bladder. Air admitted into or exhausted from hollow interior space 422 A through port 431 of an air bladder cell 422 enables the cell to be inflated or deflated to a selected pressure.
[0184] Although the shape of each air bladder cell 422 of cushion 421 shown in FIGS. 35 and 36 is that of a rectangular block, or parallelepiped, the air bladder cells may optionally have different shapes, such as convex hemispheres protruding upwards from the base of the cushion. Also, the array of air bladder cells 422 of cushion 421 may be parts of a unitary structure with a common base panel 423 which has individual rectangular-block shaped, hemispherical or hollow inflatable bodies of other shapes protruding upwardly from the common unitary base panel.
[0185] Whether individual air bladder cells 422 are separate bodies or upper inflatable shell-like portions protruding upwardly from a common base, air inlet/exhaust port tubes 431 of each air bladder cell 422 , or selected air bladder cells 422 , may be located in the base panel 423 of the cell and protrude downwardly from the cell, rather than being located in a side wall and protruding laterally outwards, as shown in FIGS. 35 and 36A .
[0186] As shown in FIGS. 35 , 36 and 39 , body force minimization apparatus 420 includes a force sensor array 432 which has a matrix of individual force sensors 433 , with at least one sensor positioned on the upper surface 428 of each air bladder cell 422 . As will be explained in detail below, each force sensor 433 comprises a force sensitive transducer which has an electrical resistance that varies inversely with the magnitude of a normal, i.e., perpendicular force exerted on the sensor by an object such as the body of a person supported by overlay cushion 421 . In one embodiment, force sensor array 432 is maintained in position on the upper surfaces of air bladder cells 422 by a water-proof, form-fitting contour fabric sheet 421 A which fits tightly and removably over cushion 421 , as shown in FIG. 37 .
[0187] Referring to FIG. 35 , it may be seen that body force minimization apparatus 420 includes an electronic control module 435 . As will be explained in detail below, electronic control module 435 includes sensor interface circuitry 436 for electrical interconnection to sensors 433 . Electronic control module 435 also includes a computer 437 which is interconnected with sensor interface circuitry 436 . Computer 437 is programmed to receive input signals from sensor interface circuitry 436 , measure the resistance of individual sensors 433 and calculate therefrom the magnitude of forces exerted on each sensor, make calculations based on the force measurements, and issue command signals to control the pressure in individual air bladder cells 422 which are calculated using an algorithm to minimize force concentrations on the cells.
[0188] In one embodiment of apparatus 420 , measurement of the resistance of each sensor 433 is facilitated by arranging the sensors into a matrix array of rows and columns. With this arrangement, individual resistances of a 6×2 array 432 of sensors 433 may be measured using 6 row interface conductors and 2 column interface conductors 450 , 451 , as shown in FIG. 35 .
[0189] To avoid cross talk between measurements of individual sensors 433 , the aforementioned row-column addressing arrangement requires that each sensor have a non-bilateral, asymmetric current versus voltage characteristics, e.g., a diode-like impedance characteristic. As will be described in detail below, the present invention includes a novel sensor having the required diode-like characteristic. Alternatively, using force sensors 433 which do not have a diode-like characteristic, the force sensor array 432 can be partitioned into 12 separate rectangular sensors 433 each electrically isolated from one another, with a separate pair of interface conductors connected to upper and lower electrodes of each sensor.
[0190] As shown in FIG. 35 , body force minimization apparatus 420 includes an air pump or compressor 440 for providing pressurized air to the input port 442 of a selector valve manifold 441 . Selector valve manifold 441 has 12 outlet ports 443 A, each connected through a valve 443 to a separate air bladder cell inlet port 431 . As will be explained in detail below, the compressor 440 , selector valve manifold 441 and valves 443 are operably interconnected to computer 437 and an air pressure measurement transducer 444 . Pressure transducer 444 outputs an electrical signal proportional to pressure, which is input to computer 437 . This arrangement enables the inflation pressure of each air bladder cell 422 to be individually measured and varied under control of the computer 437 .
[0191] FIGS. 36A , 38 and 39 illustrate details of the construction of force sensor array 432 . As shown in those figures, sensor array 432 includes an upper cover sheet 445 made of a thin flexible, elastically stretchable material. In an example embodiment of sensor array 432 fabricated by the present inventor, cover sheet 445 was made of “two-way stretch” Lycra-like material which had a thickness of about 0.010 inch and a thread count of about 88 threads per inch. That material had the trade name Millglass Platinum, Style No. (24)7579, obtained from the Milliken & Company, P.O. Box 1926, Spartanburg, S.C. 29304.
[0192] Referring to FIG. 39 , sensor array 432 includes an upper, column conductor sheet 446 which is fixed to the lower surface of upper flexible cover sheet 445 , by flexible adhesive strips made of 3M transfer tape 950 , or a flexible adhesive such as Lepage's latex contact adhesive. Column conductor sheet 446 is made of a woven fabric matrix sheet composed of 92% nylon and 8% Dorlastan fibers, which give the sheet a flexible, two-way stretch elasticity. The fabric matrix sheet of conductor sheet 446 is electroless plated with a base coating of copper, followed by an outer coating of nickel. The metallic coatings completely impregnate the surfaces of fibers adjacent to interstices of the mesh fabric, as well as the upper and lower surfaces 447 , 448 of the conductor sheet 446 , thus forming electrically conductive paths between the upper and lower surfaces 447 and 448 . The present inventor has found that a suitable conductive fabric for conductor sheet is a Woven Silver brand, Catalog #A251 available from Lessemb Company, 809 Madison Avenue, Albany, N.Y. 12208, USA.
[0193] In an example embodiment of sensor array 432 , upper conductive sheet 446 was fabricated from the Woven Silver, Catalog #A 151 material described above. The surface resistivity of upper and lower surfaces 447 , 448 of that material was about 1 ohm per square or less, and the inter-layer resistance between upper and lower surfaces 447 , 448 was about 50 ohms per square.
[0194] In one embodiment of sensor array 432 , individual conductive pads, or rows or columns of conductors, are formed by etching metal-free channels vertically through conductor sheet 446 , from the top of upper conductive surface 447 , all the way to the bottom of lower conductive surface 448 . Thus, as shown in FIG. 39 , narrow longitudinally disposed straight channels 449 are etched through upper column conductor sheet 446 . This construction results in the formation of two adjacent, relatively wide, longitudinally elongated left and right planar column electrodes 450 , 451 . The adjacent left and right column electrodes are separated by a relatively thin channel 449 , thus electrically isolating the adjacent column electrodes from each other.
[0195] Insulating channels 449 are etched through upper conductor sheet 446 to form column electrodes 450 and 451 by the following novel process.
[0196] First, to prevent capillary wicking and resultant wetting of a subsequently applied etchant solution to fabric conductor sheet 446 , the sheet is pre-processed by treating it with a hydrophobic substance such as PTFE. The treatment can be made by spraying the conductor fabric sheet 446 with an aerosol containing a hydrophobic material such as PTFE. A suitable aerosol spray is marketed under the trade name Scotch Guard by the 3M Company, St. Paul, Minn. Areas of fabric conductor sheet 446 which are to have insulating channels 449 formed therein are masked from the hydrophobic treatment by adhering strips of masking tape which have the shape of the channels to the sheet before applying the hydrophobic material to the sheet.
[0197] Following the pre-processing of conductor sheet 446 to make it hydrophobic, sheets of masking tape are adhered tightly to both upper and lower surfaces 447 , 448 of the conductor sheet, using a roller or press to insure that there are no voids between the masking tape and surfaces, which could allow etchant solution to contact the conductive surfaces. Next, strips of masking tape having the shape of insulating channels 449 are removed from the conductor sheet. Optionally, the strips of masking tape to be removed are preformed by die-cutting partially through larger sheets of masking tape.
[0198] After strips of masking tape corresponding to channels 449 have been stripped from conductor sheet 446 , the conductive metal coatings of the fabric sheet aligned with the channels is chemically etched away. One method of performing the chemical etching uses a concentrated solution of 10 mg ammonium phosphate in 30 ml of water. The ammonium phosphate solution is mixed with methyl cellulose solid powder, at a concentration of 10 percent methyl cellulose powder until a gel consistency is obtained. The etchant gel thus formed is then rollered onto the areas of upper and lower surfaces 447 , 448 of conductor sheet 446 , over channels 449 . The etchant gel is allowed to reside on channels 449 for approximately 1 hour, at room temperature, during which time the nickel and copper plating of the fabric matrix of conductor sheet 446 , in vertical alignment with channels 449 , is completely removed, thus making the channels electrically insulating. This process separates the conductor sheet into left and right column electrodes 450 , 451 , respectively.
[0199] The etching process which forms insulating channel 449 is completed by rinsing the etchant gel from upper and lower surfaces 447 , 448 of conductor sheet 446 , followed by removal of the masking tape from the upper and lower surfaces.
[0200] Referring still to FIG. 39 , it may be seen that sensor array 432 includes a thin piezoresistive sheet 452 which has on an upper surface 453 , that is in intimate contact with lower surfaces of left and right column electrodes 450 , 451 . Piezoresistive sheet 452 also has a lower surface 454 which is in intimate electrical contact with the upper surfaces of row electrodes on a lower row conductor sheet 456 . Lower, row conductor sheet 456 has a construction exactly similar to that of upper, column conductor sheet 446 . Thus, lower row conductor sheet 456 has upper and lower conductive surfaces 457 , 458 , and narrow, laterally disposed insulating channels 459 which are positioned between and define row electrodes 461 , 462 , 463 , 464 , 465 , 466 .
[0201] The function of piezoresistive sheet 452 of sensor array 432 is to form a conductive path between column and row electrodes, e.g., left-hand column electrode 450 and rear row electrode 461 , the resistance of which path varies in a predetermined fashion as a function of normal force exerted on the sensor array.
[0202] In example embodiments of sensor array 432 , piezoresistive sheet 452 was fabricated by coating a stretchy, thin Lycra-like fabric sheet with a piezoresistive material. A suitable fabric sheet, which forms a matrix for supporting the piezoresistive material, was a fabric known by the trade name Platinum, Milliken, Style #247579, obtained from the manufacturer, Milliken & Company, Spartanburg, S.C., USA. That fabric had a fiber content of 69 percent nylon and 31 percent Spandex, a thread count of about 88 threads per inch, and a thickness of 0.010 inch. The piezoresistive material used to coat the fabric matrix is made as follows:
[0203] A solution of graphite, carbon powder, nickel powder and acrylic binder are mixed in proportions as required to obtain the desired resistance and piezoresistive properties. Silver coated nickel flake is used to achieve force response in the low force range of 0 to 1 psi, graphite is used for the mid range of 1 to 5 psi and Charcoal Lamp Black is used for high force range of 5 to 1000 psi. Following is a description of the substances which are constituents of the piezoresistive material:
[0204] Silver Coated Nickel Flake:
Platelets approximately one micron thick and 5 microns in diameter. Screen Analysis (−325 Mesh) 95%. Apparent Density 2.8. Microtrac d50/microns 12-17. Available from: Novamet Specialty Products Corporation, 681 Lawlins Road, Wyckoff, N.J. 07481
[0211] Graphite Powder:
Synthetic graphite, AC-4722T Available from: Anachemia Science 4-214 DeBaets Street Winnipeg, MB R2J 3W6
[0216] Charcoal Lamp Black Powder:
Anachemia Part number AC-2155 Available from: Anachemia Science 4-214 DeBaets Street Winnipeg, MB R2J 3W6
[0221] Acrylic Binder:
Staticide Acrylic High Performance Floor Finish P/N 4000-1 Ph 8.4 to 9.0 Available from: Static Specialties Co. ltd. 1371-4 Church Street Bohemia, N.Y. 11716
[0227] Following are examples of mixtures used to make piezoresistive materials having different sensitivities:
[0228] Example I for forces in the range of 0 to 30 psi:
200 ml of acrylic binder 10 ml of nickel flake powder 10 ml of graphite powder 20 ml of carbon black
[0233] Example II for forces in the range of 0-100 psi
200 ml of acrylic binder 5 ml of nickel flake powder 5 ml of graphite powder 30 ml of carbon black
[0238] Example III for forces in the range of 0-1000 psi
200 ml of acrylic binder 1 ml of nickel flake powder 1 ml of graphite powder 40 ml of carbon black
[0243] The fabric matrix for piezoresistive sheet 452 is submerged in the piezoresistive coating mixture. Excess material is rolled off and the sheet is hung and allowed to air dry.
[0244] FIG. 40 illustrates calculation of a minimum spacing S between adjacent air bladder cells 422 , and a minimum width of non-conductive strip 449 between adjacent conductors of sensor array 432 .
[0245] Referring to FIG. 40 , as a patient sinks into a deflating bladder 422 , the upper force sensor layer 433 is drawn down and away from the bladder over which it was initially positioned. If the non-conductive strip 449 is too narrow, there is a possibility that a conductor such as column conductor 450 overlying the deflating bladder will contact adjacent conductor 451 and, thus register forces that are not representative of the force over the bladder in which it was originally positioned. It is therefore necessary to make the non-conductive strip 449 wide enough to prevent this from happening. If we assume a simple situation wherein an air bladder cell is deflated until the center of the cell, then the force sensing layer is drawn down a distance equal to the diagonals (C 1 and C 2 ) as shown in FIG. 40 , the width S of non-conductive strip 449 should be made equal to or greater than (C 1 +C 2 −the width of the bladder) to prevent forces being misread as coming from a neighboring cell.
[0246] FIG. 28 illustrates the electrical resistance of a one-inch square piezoresistive force sensor element 448 using a piezoresistive sheet 437 having the formulation listed for an example sensor array 432 shown in FIGS. 35 and 36 , and fabricated as described above, as a function of normal force or pressure exerted on the upper surface 447 of upper substrate sheet 433 of sensor array 432 . As shown in FIG. 28 , the resistance varies inversely as a function of normal force.
[0247] As shown in FIGS. 35 and 39 , left and right column electrodes 450 and 451 , in vertical alignment with row electrodes 461 , 462 , 463 , 464 , 465 , 466 , of 12 form with piezoresistive layer sheet 452 between the column and row electrodes a 2×6 rectangular matrix array of 12 force sensors 433 .
[0248] Optionally, the upper and lower electrodes for each sensor 433 could be segmented into electrically isolated rectangular pads by etching channels 449 , 459 through both upper conductive sheet 446 and lower conductive sheet 456 . This arrangement would require a separate pair of lead-out conductors for each of the 12 sensors, i.e., a total of 24 leads.
[0249] As shown in FIGS. 35 and 39 , sensor array is arranged into rows and columns, thus requiring only 8 lead-out conductors. However, as shown in FIG. 23 , if matrix addressing of sensor array 432 is used to measure the resistance of individual sensors 433 to thereby determine normal forces exerted on the sensors, there is a substantial cross-talk between the resistance on an addressed sensor 433 and nonselected sensors because of parallel current paths to non-addressed sensors. To overcome this cross-talk problem, the present inventor has developed a method for modifying sensors 433 to give them a diode-like characteristic. As may be confirmed by referring to FIG. 24 , the cross-talk between sensors 433 which have a non-bilateral, polarity-sensitive transfer function, mitigates the cross-talk problem present in the matrix of symmetrically conductive sensors 433 shown in FIG. 23 .
[0250] Sensors 433 are modified to have a diode-like characteristic by modifying the preparation of piezoresistive layer sheet 452 , as follows: First, a piezoresistive layer sheet 452 is prepared by the process described above. Then, either the upper surface 469 or the lower surface 470 of the piezoresistive coating 467 of piezoresistive sheet 452 is modified to form thereon a P-N, semiconductor-type junction.
[0251] Modification of piezoresistive coating 467 to form a P-N junction is performed by first preparing a slurry which has the composition of one of the three example mixtures described above, but modified by the addition of 5 ml each of copper oxide (CuO) in the form of a fine powder of 50-micron size particles, and 5 ml of cuprous oxide (Cu 2 O) in the form of a fine powder of 50-micron size particles and thoroughly stir-mixing the foregoing ingredients. The resultant solution is then reduced using about 30 mg of solution of sodium borohydride, also known as sodium tetrahydroborate (NaBH4) or ammonium phosphate, to form a solution having a pH of about 5.5. The solution is then coated onto the upper surface 469 or lower surface 470 of piezoresistive coating 468 on piezoresistive sheet 452 . This coating process is performed using a roller coating process which results in about 0.5 ml of solution per square centimeters being applied. The surface coating is then allowed to air-dry at room temperature and a relative humidity of less than 20%, for 4 hours. After the coated surface has dried, it functions as a P-type semiconductor, while the uncoated side of coating 468 functions as an N-type semiconductor of P-N junction diode.
[0252] FIG. 29 illustrates a sensor 433 which has been prepared as described above to give the sensor a diode-like characteristic, and a circuit for obtaining the 1-V (current versus voltage) transfer function of the sensor. FIG. 30 shows a typical 1-V curve for sensor 433 of FIG. 29 .
[0253] As stated above, the advantage of modifying sensors 433 by adding a semi-conductive layer that acts like a diode is that it reduces cross talk between sensors. As is shown in FIG. 23 , this cross-talk occurs because of the so-called “completing the square” phenomenon, in which three connections are made in a square matrix array of three non-addressed resistors that form the three corners of a square. Thus, any two connections in a vertical column and a third one in the same row function as either connection in an X-Y array of conductors. The resistor at the fourth corner of the square shows up as a phantom in parallel with an addressed resistor because the current can travel backwards through that resistor, and forward through the other resistors. Care and additional expense must be taken in the electronics to eliminate the contribution of this phantom. For example, if, as is shown in FIG. 23 , a potential V is applied between row and column conductors X 1 Y 1 , to thereby determine the resistance of piezoresistive sensor resistance R 11 , reverse current flow through “phantom” resistor R 22 would cause the sum of resistances R 12 +R 22 +R 22 to shunt R 11 , resulting in the parallel current flow paths indicated by arrows in FIG. 23 , which in turn would result in the following incorrect value of resistance:
[0254] R x1 y 1 =R 11 //(R 12 +[R 22 ]+R 21 ), R x1 Y 1 =R 11 (R 12 +[R 22 ]+R 21 )/(R 11 +R 12 +[R 22 ]+R 21 ), where brackets around a resistance value indicate current flow in a counterclockwise direction through that resistor, rather than clockwise, i.e., diagonally downwards towards the left. Thus, for example, if each of the four resistances listed above had a value of 10 ohms, the measured value of R 11 would be:
[0255] R 11 =10(10+10+10)/(10+10+10+10)=300/40=7.5 ohms, i.e., 25% below the actual value, 10 ohms, of R 11 . If the resistance values of R 12 , R 22 and R 21 of the three non-addressed piezoresistive sensors 433 were each lower, e.g., 1 ohm, because of greater forces concentrated on those sensors 433 , the measured value of R 11 would be:
[0256] R 11 =10(1+1+1)/(10+1+1+1)=30/13=2.31 ohms, i.e., a value of about 77 percent below the actual value of R 11 .
[0257] On the other hand, by placing a diode in series with each piezoresistive sensor element 433 , as shown in FIG. 24 , the electrical resistance of an element measured in a reverse, counterclockwise direction a test current flow through the sensor element, e.g., R 22 , would be for practical purposes arbitrarily large, or infinity compared to the clockwise forward paths of current through the other resistances shown in FIGS. 23 and 24 . In this case, the measured resistance value for a 2×2 matrix of four resistances each having a value of 10 ohms would be:
[0258] R x1 y 1 =10(1+∞+1)/(10+1+∞+1)=10 ohms, the correct value.
[0259] Thus, modifying each sensor 433 element to include a p-n junction thereby gives the sensor element a diode-like characteristic that electrically isolates, i.e., prevents backward current flow, through each sensor element 433 . This enables the correct value of electrical resistance R x1 y 1 of each sensor element 433 and hence forces exerted thereon to be measured accurately using row and column matrix addressing rather than requiring a separate pair of conductors for each sensor element.
[0260] The above-described components of force minimization apparatus 420 are interconnected to form a closed-loop servo control system. That system is effective in reducing body force concentrations using an algorithm according to the method described herein. An understanding of this method and apparatus may be facilitated by referring to FIG. 41 , which is a block diagram of an electro-pneumatic controller system component 420 A of apparatus 420 , in conjunction with the diagrammatic view of the apparatus shown in FIG. 35 , and the perspective view shown in FIG. 39 .
[0261] Referring to FIG. 41 , it may be seen that electro-pneumatic controller apparatus 420 A includes a computer 37 which is bidirectionally coupled to force sensor array 432 through force sensor interface module 436 . The sensor interface module 436 includes a Digital-to-Analog Converter (DAC) 471 for generating in response to control signals from computer 437 test voltages or currents which are directed to matrix addressed individual force sensors 433 .
[0262] Individual force sensors 433 are addressed by connecting one terminal of a current or voltage source controlled by DAC 471 to a selected one of X-row conductors 1 - 6 by an X multiplexer 472 , and connecting the other terminal of the source to a selected one of Y-column conductors 1 or 2 by a Y multiplexer 473 . Sensor interface module 437 also included an Analog-to-Digital Converter (ADC) 474 which measures the voltage drop or current through a sensor 433 resulting from application of a test current or voltage, and inputs the measured value to computer 437 . Using predetermined scale factors, computer 437 calculates the instantaneous value of electrical resistance of a selected addressed sensor 433 , and from that resistance value, a corresponding normal force instantaneously exerted on the addressed sensor.
[0263] In response to control signals cyclically issued by computer 437 , X multiplexer 472 and Y multiplexer 473 are used to cyclically measure the resistance of each force sensor element 433 , at a relatively rapid rate of, for example, 3,000 samples per second, enabling computer 437 to calculate the force exerted on each force sensor 433 at that sampling rate.
[0264] Referring still to FIG. 41 , apparatus 420 includes a pressure control module 475 for dynamically controlling the air pressure in each individual air bladder cell 422 , in response to command signals issued by computer 437 , based upon values of force measured by sensor array 432 and an algorithm programmed in the computer. As shown in FIG. 41 , pressure control module 475 is operably interconnected to air compressor 440 and air pressure transducer 444 at output port 476 of the compressor to pressurize air in the outlet port to a value controllable by computer 437 .
[0265] Outlet port 476 of compressor 440 is coupled to inlet port 442 of a 12-outlet port manifold 441 . In response to electrical control signals issued by computer 437 and routed through pressure control module 475 , each of 12 individual air bladder cell inlet selector valves 443 connected to separate outlet ports 443 A of manifold 441 is individually controllable.
[0266] In a first, open position of a selector valve 443 , the air inlet port 431 of a selected air bladder cell 422 is pressurized to a pressure measured by transducer 444 to a predetermined value, by turning on compressor 440 , to thereby inflate the cell to a desired pressure. Alternatively, with compressor 440 in an off-mode, a vent valve 477 coupled to the input port 442 of manifold 441 may be opened to deflate an air bladder cell 422 to a lower pressure value by exhausting air to the atmosphere.
[0267] After a selected one of the 12 selector valves 443 has been opened in response to a command signal from computer 437 for a time period sufficient to inflate a selected air bladder cell 422 to a predetermined pressure, an electrical signal output by pressure transducer 444 , which is proportional to the pressure in that cell and input to computer 437 , results in the computer outputting a closure command signal to the valve and a shut-off command signal to compressor 440 .
[0268] When vent valve 477 and a selected selector valve 443 have been opened in response to command signals from computer 437 to deflate a selected air bladder cell 422 to a lower predetermined pressure, an electrical signal from pressure transducer 444 input to computer 437 results in an electrical closure command signal being output from the computer. That command signal closes vent valve 477 and the open selector valve 443 , thereby maintaining the selected lower pressure in the selected air bladder cell. In an exactly analogous fashion, the air pressure in each other air bladder cell 422 is sequentially adjustable by sending a command signal to a selector valve 443 to open that valve, and operating compressor 440 and/or vent valve 477 to inflate or deflate the air bladder cell to a predetermined pressure.
[0269] FIG. 42 is a simplified perspective view of an embodiment of a housing for electro-pneumatic apparatus 420 A shown in FIG. 41 and described above. As shown in FIGS. 41 and 42 , electro-pneumatic controller 420 A includes an operator interface module 478 . Operator interface module 478 includes manual controls, including a multi-function, on/off, mode control switch and button 479 , up and down data entry slewing buttons 480 , 481 , and a digital display 482 . Display 482 is controllable by switch 479 to selectively display air pressure within and force on selectable air bladder cells 422 , and the sum and average of all forces exerted on sensors 433 .
[0270] As shown in FIG. 42 , electro-pneumatic controller 420 A is contained in a box-like housing 483 which has protruding from a rear panel 484 thereof an L-bracket 485 for suspending the housing from a side board or end board of a bed. Housing 483 of electro-pneumatic controller 420 A also includes a tubular member 486 for interfacing air hoses 487 with air bladder cells 422 , row and column conductors 488 , 489 , to sensors 433 of sensor array 432 , and an electrical power cord 490 to a source of electrical power for powering the components of apparatus 420 A.
[0271] Force Minimization Algorithm
[0272] The force minimization apparatus described above is made up of a multiplicity of air 424 bladder cells 422 . Each cell 422 has on its upper surface a separate force sensor 433 . An air pressure transducer 444 is provided to measure the air pressure in each cell. Each force sensor is located in a potential contact region between a person lying on cushion 421 and the air bladder cell. Each piezoresistive force sensor 433 functions as a force sensitive transducer which has an electrical resistance that is inversely proportional to the maximum force exerted by a person's body on the air bladder cell 422 , the maximum force corresponding to the lowest resistance path across any part of each sensor.
[0273] As shown in FIG. 37 , each air bladder cell 422 supports a different longitudinal zone of the user such as the head, hips or heels. The compressor 440 and selector valves 443 controlling the air pressure in each zone are controlled by sensors 433 and pressure measurements made by pressure transducer 444 , using a novel algorithm implemented in computer 437 . There can be a minimum of one zone using one air bladder cell 433 , and up to N zones using n air bladder cells, wherein each zone has a force sensor 433 to measure the maximum force on that air bladder cell, the pressure transducer 444 being used to measure the air pressure in that air bladder cell. The control algorithm is one of continuous iteration wherein the force sensors 433 determine the peak force on the patient's body, and the pressure transducer 444 measures the pressure at which the force occurs. At the end of a cycle sampling forces on all sensors, the bladder air pressure is restored to the pressure where the force was minimized for all zones. This process continues and the apparatus constantly hunts to find the optimal bladder pressures for each individual cell resulting in minimizing peak forces on a person supported by overlay cushion 421 .
[0274] Algorithm Description:
[0275] Given:
[0276] N Zones each containing one air bladder cell and numbered one to N
[0277] The air bladder cell of each zone is selectably connectable to an air pressure transducer to measure P#
[0278] Each air bladder cell is fitted with an individual force sensor capable of measuring the maximum force F# exerted on the surface of each cell.
[0279] A common compressor supplies air at pressures of up to 5 psi to selected individual air bladder cells of the zones. There is a normally closed vent valve for deflating a selected air bladder cell by exhausting air to the atmosphere through the vent valve.
[0280] There is a selector valve that selects which air bladder is being inflated with air or deflated by exhausting air to the atmosphere through the vent valve.
[0281] Algorithm Steps:
[0282] 1. Pset:::: Pset, start, close vent valve
[0283] 2. Select zone i=1 by opening selector valve 1
[0284] 3. Turn the compressor on.
[0285] 4. Measure the air pressure in the air bladder cell in zone I
[0286] 5. Pressurize the zone-one air bladder cell to a predetermined upper set pressure and close the selector valve value Pset.
[0287] 6. Repeat for i+1 until i+1=N
[0288] 7. Select Zone i=I
[0289] 8. Obtain the force sensor readings for all zones.
[0290] 9. Open Vent valve.
[0291] 10. Deflate the zone-one air bladder cell to a predetermined minimum pressure and monitor all the force sensor readings on all air bladder cells. Maintain bladder pressures in all other air bladder cells at their upper set pressures. Measure forces on all air bladder cells as the single, zone-one air bladder is being deflated and compute the sum and optionally the average of all force sensor readings.
[0292] 12. Store in computer memory the pressure reading of the zone-one air bladder cell at which the minimum sum and optionally the average of all force sensor readings occurs.
[0293] 13. Restore the pressure in the zone one air bladder cell to the value where the minimum sum and average force sensor readings for all the force sensors was obtained.
[0294] 14. Close the zone-one selector valve. Maintain the pressure in zone one.
[0295] 15. Set: Count=i+1.
[0296] 16. Repeat steps 2 thru 15 until Count=i+1=N.
[0297] 17. Set: Pset=Pset, start−(Count*20%_(i.e., reduce the initial pressure in the zone one bladder).
[0298] 18. Repeat Steps 2 thru 16 (i.e., with a reduced initial pressure).
[0299] Caveat
[0300] 19. Constantly monitor all force sensors and if significant change (Delta F>0.2*F#) is detected (patient moved) start over at Step 1 .
[0301] FIG. 43 is a flow chart showing the operation of apparatus 420 utilizing the algorithm described above. Table 1 lists appropriate lower and upper initial set pressures for bladders 422 , as a function of the weight of a patient or other person supported by overlay cushion 421 of the apparatus.
[0000]
TABLE 1
Patient Weight
Minimum Pressures
Start Pressure
75-119 Pounds
5.5″ ± 0.7:H 2 O
6.5″ ± 0.7:H 2 O
10.31 ± 2 mmHg
12.18 ± 2 mmHg
120-164 Pounds
6″ ± 0.7:H 2 O
8″ ± 0.7:H 2 O
11.25 ± 2 mmHg
15 ± 2 mmHg
165-199 Pounds
8″ ± 0.7:H 2 O
10″ ± 0.7:H 2 O
15 ± 2 mmHg
18.75 ± 2 mmHg
200-250 Pounds
10″ ± 0.7:H 2 0
12″ ± 0.7:H 2 O
18.75 ± 2 mmHg
22.49 ± 2 mmHg
Maximum Pressure
26″ ± 0.7:H 2 O
48.74 ± 4 mmHg
[0302] In a variation of the method and apparatus according described above, after the pressures in each air bladder cell 422 have been optimized for minimum force concentration, inlet tubes 431 may be permanently sealed, and the adaptive cushion 421 permanently disconnected from pressure control module 475 . This variation would also enable the custom fabrication of cushions 421 using air bladder cells 422 , for customizing chair cushions to minimize force concentrations on a particular individual. Similarly, the variation of the method and apparatus could be used to customize saddle cushions or car seats.
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A force sensing array includes multiple layers of material that are arranged to define an elastically stretchable sensing sheet. The sensing sheet may be placed underneath a patient to detect interface forces or pressures between the patient and the support structure that the patient is positioned on. The force sensing array includes a plurality of force sensors. The force sensors are defined where a row conductor and a column conductor approach each other on opposite sides of a force sensing material, such as a piezoresistive material. In order to reduce electrical cross talk between the plurality of sensors, a semiconductive material is included adjacent the force sensing material to create a PN junction with the force sensing material. This PN junction acts as a diode, limiting current flow to essentially one direction, which, in turn, reduces cross talk between the multiple sensors.
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FIELD OF THE INVENTION
This invention relates to decorative trim pieces for building surface such as walls or ceilings, methods of installing the pieces, and methods of manufacturing the pieces.
BACKGROUND OF THE INVENTION
Decorative trim is used in several situations, such as used with covings, crowns, or as a cornice (trim at a junction between a ceiling and a wall), as a baseboard, (trim at a junction between a floor and a wall), picture rails, wall panel mouldings, door and window casings, or trims attached to a ceiling. Trim can be attached to adjacent surfaces in a number of ways (typically mechanically fastened and/or glued), and presents a three-dimensional decorative surface to the viewing eye when installed.
Previous trims present complications at corners. The appearance of the trim at the corners when installed depends upon several factors including length of the trim's pattern repeat, the desired length of coverage, and the accuracy of the mitred cuts at the ends of the pieces of trim at the corner. Ideally, the mitred cuts should meet smoothly and with mirrored edges across the entire surfaces of the two adjacent pieces of trim. For many installers, especially non-professional installers such as people doing their own home renovations, preparing, laying out and installing pieces of trim with adequate mitre cuts is a time-consuming and frustrating exercise, which is not always entirely successful.
SUMMARY OF THE INVENTION
The present invention improves on prior trim pieces by providing a trim piece with unitary blocks that form part of the pattern of the trim itself. Each of these blocks will provide at least two faces at angles to each other, one of which is connected to the rest of the trim piece. While pan of the decorative trim piece, the blocks are distinctive parts of the decorative trim, ideally presenting decorative breaks or highlights of the pattern,
In use to cover an inner or outer corner, a trim piece with a block at one end is positioned so that the trim piece is attached to the surface to be covered and the block is positioned so that a face looks down the second surface to be covered by a second trim piece placed to abut the block. In use to turn ninety degrees on the same surface, a decorative trim piece with a block at one end is positioned so that the trim piece is attached to the surface to be covered and the block is positioned so that a face looks down the same surface at a ninety degree angle. A second decorative trim piece is placed to abut the block.
In one aspect of the invention, there is provided a unitary decorative trim piece for installation on a building surface such as wall or ceiling, the trim piece comprising an elongate member having a central axis and a block at a first end of the member wherein the block has an end face substantially orthogonal to the axis for receipt thereagainst of the end of another trim piece when the pieces are aligned with each other for installation on a common surface.
In a feature of this aspect, the block has an obverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an inside corner formed at the juncture of adjacent walls, In another feature of this aspect, the block has a reverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an outside corner formed at the juncture of adjacent walls. In yet another feature of this aspect, the block has a lower side face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface. In a still further feature of this aspect, the block has an upper side face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface. In still another feature of this aspect, the block has a reverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an outside corner formed at the juncture of adjacent walls. In yet another feature of this aspect, the block has an upper side face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface.
In a second aspect of this invention, there is provided a unitary decorative trim piece for installation on a building surface such as a wall or a ceiling, the trim piece comprising: an elongate member having a decorative obverse face, and a central axis; first and second blocks at first and second ends of the member, wherein each of the blocks has an end face substantially orthogonal to the axis for receipt thereagainst of the end of another trim piece when the pieces are aligned with each other for installation on a common wall; the first block has an obverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an inside corner formed at the juncture of adjacent walls and has a reverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an outside corner formed at the juncture of adjacent walls; and the second block has a lower side face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface and has an upper side face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface.
In a feature of this second aspect, the end face, obverse face, and reverse face of the first block are coincident with first, second and third surfaces, respectively, of a first imaginary rectangular parallelepiped and the end face, the lower side face, and the upper side face of the second block are coincident with first, second and third surfaces, respectively, of a second imaginary rectangular parallelepiped. In another feature of this aspect, the end face, obverse face, and reverse face of the first block are coincident with first, second and third surfaces, respectively, of an imaginary rectangular parallelepiped and the end face, the lower side face, and the upper side face of the second block are coincident with first, second and third surfaces, respectively, of the imaginary rectangular parallelepiped.
In another aspect of this invention, there is provided a unitary decorative trim piece for installation on a building surface such as a wall or a ceiling, the trim piece comprising: an elongate member having a decorative obverse face; and a block at an end of the elongate member, wherein the block has a face for receipt thereagainst of the end of another trim piece when the pieces are aligned with each other for installation to form a corner on a common wall.
In still another aspect of this invention, there is provided a unitary decorative trim piece for installation on a building surface such as a wall or a ceiling, the trim piece comprising an elongate member having a decorative obverse face; and a block at an end of the elongate member, wherein the block has a face for receipt thereagainst of the end of another trim piece when the pieces are positioned with each other for installation at an inside corner.
In yet another aspect of this invention, there is provided a unitary decorative trim piece for installation on a building surface such as a wall or a ceiling the trim piece comprising: an elongate member having a decorative obverse face; and a block at an end of the elongate member, wherein the block has a face for receipt thereagainst of the end of another trim piece when the pieces are positioned with each other for installation on an outer corner.
In an additional feature of these aspects, the ratio of the length of the elongate member in the direction of the longitudinal axis of the elongate member to the length of the block in the direction of the longitudinal axis of the elongate member is at least 12:1. In another additional feature of these aspects, the ratio of the length of the elongate member in the direction of the longitudinal axis of the elongate member to the length of the block in the direction of the longitudinal axis of the elongate member is at least 20:1.
In still another aspect of the invention, there is provided a unitary decorative trim piece for installation on a building surface such as wall or ceiling, the trim piece comprising: an elongate member having a central axis; a first block at a first end of the member; wherein: the first block has an end face substantially orthogonal to the axis for receipt thereagainst of the end of another trim piece when the pieces are aligned with each other for installation on a common surface; the first block has an obverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an inside corner formed at the juncture of adjacent walls; and the first block has a reverse face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned for installation at an outside corner formed at the juncture of adjacent walls.
In another feature of this aspect, the trim piece further comprises: a second block at a second end of the member; wherein: the second block has an end face substantially orthogonal to the axis for receipt thereagainst of the end of another trim piece when the pieces are aligned with each other for installation on a common surface; the second block has an upper face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface, and the second block has a lower face substantially orthogonal to the end face for receipt thereagainst of the end of another trim piece when the pieces are positioned to together form a corner on a common surface.
In another aspect of the invention, there is provided a commercial package comprising (a) a trim piece and (b) instructions for removing at least one of the blocks thereof so as to provide the elongate member with a free end for abutment with the end face, obverse face or reverse face of the first block, or the end face, the lower side face or the upper side face of the second block, of a second said trim piece.
In still another aspect of the invention, there is provided a commercial package comprising (a) a trim piece and (b) instructions for removing at least one of the blocks thereof and removing part of the elongate member with a square cut so as to provide the elongate member with a free end for abutment with the end face, obverse face or reverse face of the first block, or the end face, the lower side face or the upper side face of the second block, of a second said trim piece.
In yet another aspect of the invention, there is provided a commercial package comprising (a) a trim piece and (b) instructions for removing at both of the blocks thereof so as to provide the elongate member with a first free end for abutment with the end face, obverse face or reverse face of the first block, or the end face, the lower side face or the upper side face of the second block, of a second said trim piece and a second free end for abutment with the end face, obverse face or reverse face of the first block, or the end face, the lower side face or the upper side face of the second block, of a third said trim piece.
In yet another aspect of the invention, there is provided a method of installing trim pieces to form decorative trim on one or more building walls, the method comprising the steps of:
(A) installing a said piece in a horizontal position on a first wall with the first block located at an inside corner formed by the juncture of said first wall and a second wall, and as required, any of the following steps (B) to (F):
(B) (i) removing the first block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the end face of the second block of another piece; and
(ii) installing the uninstalled piece on either the first wall or the second wall in aligned orientation with a previously installed piece and with the free end thereof in abutment with the end face of the second block of the previously installed piece;
(C) repeating steps (B)(i) and B(ii);
(D) removing the second block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the face of another trim piece, and installing the uninstalled piece in a horizontal position on the second wall and with the first free end thereof in abutment with the obverse face of the first block of the piece installed in step (A);
(E) (i) removing the second block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the end face of the first block of another piece; and
(ii) installing the uninstalled piece on either the first wall or the second wall in aligned orientation with a previously installed piece and with the free end thereof in abutment with the end face of the first block of the previously installed piece;
(F) repeating steps (i)(i) and (E)(ii),
In still another aspect of the invention, there is provided a method of installing trim pieces to form decorative trim on one or more building walls, the method comprising the steps of:
(A) installing a said piece in a horizontal position on a first wall with the first block located at an outside corner formed by the juncture of said first wall and a second wall, and as required, any of the following steps (B) to (F)
(B) (i) removing the first block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the end face of the second block of another piece; and
(ii) installing the uninstalled piece on either the first wall or the second wall in aligned orientation with a previously installed piece and with the free end thereof in abutment with the end face of the second block of the previously installed piece;
(C) repeating steps (B)(i) and B(ii),
(D) removing the second block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the face of another trim piece, and installing the uninstalled piece in a horizontal position on the second wall and with the first free end thereof in abutment with the reverse face of the first block of the piece installed in stop (A);
(E) (i) removing the second block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the end face of the first block of another piece; and
(ii) installing the uninstalled piece on either the first wall or the second wall in aligned orientation with a previously installed piece and with the free end thereof in abutment with the end face of the first block of the previously installed piece;
(F) repeating steps (EXi) and (E)(ii).
In yet another aspect of the invention, there is provided a method of installing trim pieces to form decorative trim on a common building wall, the method comprising the steps of:
(A) installing a said piece in a horizontal position on the common wall, and as required, any of the following steps (B) to (F):
(B) (i) removing the first block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the end face of the second block of another piece; and
(ii) installing the uninstalled piece on the common wall in aligned orientation with a previously installed piece and with the free end thereof in abutment with the end face of the second block of the previously installed piece;
(C) repeating steps ( 13 )(i) and B(ii),
(D) removing the second block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the face of another trim piece, and installing the uninstalled piece in a vertical position on the common wall and with the first free end thereof in abutment with the lower face or upper face of the first block of the piece installed in step (A);
(E) (i) removing the second block from an uninstalled piece so as to provide the elongate member thereof with a free end for abutment against the end face of the first block of another piece; and
(ii) installing the uninstalled piece on the common wall in aligned orientation with a previously installed piece and with the free end thereof in abutment with the end face of the first block of the previously installed piece;
(F) repeating steps (E)(i) and (E)(ii).
In still another aspect of the invention, there is provided a method of installing trim pieces to form decorative trim on the common wall, the method comprising the steps of installing a first said trim piece on the common wall; obtaining a second said trim piece with a free end at the end of the elongate member opposite the block; and installing the second said trim piece on the common wall in position with the first said trim piece to form a corner on the common wall and with the free end of the second trim piece in abutment with the face of the block of the first said trim piece.
In still another aspect of the invention, there is provided a method of installing trim pieces to form decorative trim on an inside corner formed by the juncture of a first and a second wall, the method comprising the steps of installing a first said trim piece on the first wall so the block is located at the inside corner; obtaining a second said trim piece with a free end at the end of the elongate member opposite the block, and installing the second said trim piece on the second wall in position to complete the inside corner with the first said trim piece and with the free end of the second trim piece in abutment with the obverse face of the block of the first said trim piece.
In still another aspect of the invention, there is provided a method of installing trim pieces to form decorative trim on an outer corner formed by the juncture of a first and a second wall, the method comprising the steps of: installing a first said trim piece on the first wall so the block is located at the outside corner; obtaining a second said trim piece with a free end at the end of the elongate member opposite the block, and installing the second said trim piece on the second wall in position to complete the outside corner with the first said trim piece and with the free end of the second trim piece in abutment with the reverse face of the block of the first said trim piece.
In still another aspect of the invention, there is provided a method of manufacturing a unitary decorative trim wherein the elongate member and block are formed as a single piece. In another feature of this aspect, the unitary decorative trim is made by an open cast molding process. In still another feature of this aspect, the unitary decorative trim is made by an injection molding process. In yet another feature of this aspect, the unitary decorative trim is from polyurethane.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of a decorative trim piece;
FIG. 2 is a perspective view of a second embodiment of a decorative trim piece;
FIG. 3 is a perspective view of several decorative trim pieces, illustrating their installation around several walls and a ceiling;
FIG. 4A is a perspective view of a third embodiment of a decorative trim piece, with two different blocks allowing of additional decorative trim pieces in different directions;
FIG. 4B is a elevation view of the decorative trim piece of FIG. 4A;
FIG. 4C is a cut-away view or section of decorative trim piece of FIG. 4A along cut 4 C in FIG. 4B;
FIG. 4D is a cut away view of an alternative embodiment of the decorative trim piece of FIG. 4A;
FIG. 5 is a perspective view of an installation of decorative trim pieces with a coving; and
FIG. 6 is a plan view of a decorative trim piece for use with a corner with an obtuse angle.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
An embodiment of the invention is shown in FIG. 1 . Turning to FIG. 1, decorative trim piece 20 includes an elongate member 22 with a central axis 23 attached to a block 24 . Elongate member 22 has a obverse face 26 . Block 24 has a face 28 to which elongate member 22 is attached at end 25 . Elongate member 22 has an end 21 which is not covered. In the embodiment of FIG. 1, block 24 is a cube, and so has five faces in addition to face 28 : end face 32 which is orthogonal to axis 23 , an obverse face 34 orthogonal to end face 32 , a reverse face 38 orthogonal to end face 32 , a lower side face 30 orthogonal to end face 32 , and an upper side face 36 orthogonal to end face 32 .
A second embodiment of the invention is shown in FIG. 2 . Turning to FIG. 2, decorative trim piece 40 includes an elongate member 42 having a central axis 43 attached to a block 44 at end 46 and attached to a second block 48 at end 50 . Elongate member 42 has an obverse face 52 . Block 44 has a face 54 to which elongate member 42 is attached at end 46 . In the embodiment of FIG. 2, block 44 is a cube, and so has five faces in addition to face 54 : end face 60 which is orthogonal to axis 43 , an obverse face 62 orthogonal to end face 60 , a reverse face 58 orthogonal to end face 60 , a lower side face 56 orthogonal to end face 60 , and an upper side face 64 orthogonal to end face 60 . Similarly, block 48 has a face 66 to which elongate member 42 is attached at end 50 . Block 48 is a cube, and so has five faces in addition to face 66 : end face 72 which is orthogonal to axis 43 , an obverse face 68 orthogonal to end face 72 , a reverse face 76 orthogonal to end face 72 , a lower side face 14 orthogonal to end face 72 , and an upper side face 70 orthogonal to end face 72 .
The trim piece embodiment 20 in FIG. 1 and the trim piece embodiment 40 in FIG. 2 are related in that, if a square cut is made in the elongate member 42 of FIG. 2, a trim piece embodiment 20 and an inverse of trim piece 20 are created.
The trim pieces of the invention are provided as single pieces to the consumer and are thus called “unitary”. A preferred manufacturing process is to prepare the piece in a mold (such as an open-cast mold). In such a process it is thus convenient to manufacture all portions of the piece in a single step. This does not imply that during the manufacturing stage, a block and an elongate member of a trim piece could not be manufactured as separate parts and affixed to each other for sale to a consumer.
The installation of the decorative trim pieces is illustrated in FIG. 3 . Tuning to FIG. 3, walls 80 , 82 and 84 are attached to a ceiling 86 . Two alternative installations of several decorative trim pieces 88 and 90 are shown.
Several trim pieces 88 includes: decorative trim piece 100 which has block 102 attached to elongate member 104 ; decorative trim piece 106 which has block 108 attached to elongate member 110 ; decorative trim piece 112 which has block 114 attached to elongate member 116 ; decorative trim piece 118 which has block 120 attached to elongate member 122 ; and elongate member 124 which extends off the edge of the figure.
In installation, decorative trim piece 106 is attached to the ceiling 86 . Trim piece 112 is in turn placed so elongate member 116 abuts reverse face 130 of block 108 . This creates a turn in the trim around a imaginary ninety degree outer corner. Similarly, trim piece 118 is in turn a placed so elongate member 122 abuts obverse face 134 of block 114 . This creates a turn in the trim around a imaginary ninety degree inner corner. In turn, elongate member 124 may be abutted against end face 138 of block 120 . This extends the trim along the axis of trim piece 118 . Similarly, end face 140 of block 102 of trim piece 100 may be abutted against end 142 of elongate member 110 to extend the trim in the axis of trim piece 106 .
In FIG. 3, the several trim pieces 88 have elongate members that simply present a curved obverse face. The blocks have a square point on their lower faces.
It should be noted that, if the elongate members of trim pieces 88 are cut to the appropriate lengths (by making square cuts in the elongate members) and moved in the direction of arrows 92 and 94 , the several trim pieces 8 : could fit snugly against walls 80 , 82 and 84 .
Several trim pieces 90 includes; trim piece 144 which has block 146 attached to elongate member 148 ; trim piece 150 which has block 152 attached to elongate member 154 ; trim piece 156 which has block 158 attached to elongate member 160 ; trim piece 162 which has block 164 attached to elongate member 166 ; and elongate member 168 which extends off the edge of the figure,
In installation, trim piece 150 is attached to wall 84 in position so that block 152 rests in corner 133 . Trim piece 144 is in turn placed so end face 170 of block 146 abuts elongate member 154 . This extends the trim in the same axis as trim piece 150 .
Trim piece 156 is cut (by making a square cut in elongate member 160 ) and placed X attached to wall 32 so that end 173 of elongate member 160 abuts obverse face 172 of block 152 , and reverse face 174 of block 158 faces down wall 80 . This creates a turn in the trim around ninety degree inner corner 133 . Similarly, trim piece 162 is cut (by making a square cut in elongate member 166 ) and placed attached to wall 80 so that end 177 of elongate member 166 abuts reverse face 174 of block 158 , and block 164 rests against wall 80 so that lower face 178 of block 164 faces down wall 80 . Further trim pieces (represented by elongate member 168 ) may be placed in a direction orthogonal to lower face 178 . This creates a ninety-degree corner in the trim on common wall 80 .
It should be noted that, if the elongate members of trim pieces 90 are cut to the appropriate lengths (by making square cuts in the elongate members) and moved in the direction of arrows 96 and 98 , the several trim pieces 90 could fit snugly against ceiling 86 .
It should be noted that block 164 is a different shape than blocks 146 , 152 and 153 . The face against which an end of an elongate piece is to abut, lower face 178 , should be of a size suitable to have the end of a decorative trim piece abut against it, or to be of similar size to the other faces which abut the end of an elongate piece. Since the installation takes a 90 degree turn to a different plane than the previous decorative trim pieces in the several decorative trim pieces 90 , a differently shaped block is needed.
The cuts needed to install decorative trim pieces as illustrated in FIG. 3 are square cuts, not mitre cuts, Square cuts are much easier to make properly than mitre cuts, and particularly so for the “do it-yourself” home improvement market.
As seen in FIG. 3, in the multiple trim pieces 90 , two types of blocks are used: the thinner blocks 146 , 152 and 158 , and thicker block 164 . These different blocks are used, respectively, to run the trim either in a straight line along a wall or around an inner or outer corner, and to run the trim around a corner on a wall.
A particularly preferred embodiment is a trim piece with two different blocks to allow the trim pieces to be aligned with each other, installed around inside corners, around outside corners, or to form 90 degree turns (in either an inner or outer direction), or both as desired. This is further explained in FIGS. 4A and 4B. Turning to FIG. 4A, trim piece 180 has an elongate member 182 with two differently-shaped blocks 134 and 186 . This trim piece 180 may be seen in elevation view from the obverse face 190 in FIG. 4 B. Tuning to FIG. 4B, block 134 has a length A on sides 192 and 194 . In contrast, block 186 has a length A on side 196 but a length B on sides 198 and 200 . FIG. 4C is a side view along cut 4 C in FIG. 4 B. Turning to FIG. 4C, block 186 has a length A on side 188 and a length B on side 200 . Decorative obverse side 190 may be somewhat shorter (but is usually not longer) than the length of side 200 , a seen in FIG. 4C, where decorative obverse side has a length of C.
Since block 186 has a length of A in only sides 188 and 196 and not in side 198 , block 196 only allows ninety degree changes in direction in the plane of elongate member 182 rotated around an axis 202 . In contrast, block 184 has sides 192 , 194 and 208 with a length A, and so allows ninety degree changes of direction from axis 207 as well as allowing the trim to continue in the direction of axis 207 .
As seen in FIG. 4C, the elongate member 182 extends to lie along side 188 and side 200 . When installed, trim piece 180 is attached to an abutting surface, typically along side 188 , although attachment along either or both of sides 188 and 200 is possible. However, as seen in FIG. 4D, elongate member 182 only needs to run partially along sides 188 and 200 (portions 202 and 204 , respectively) to allow for attachment to abutting surfaces.
In a preferred embodiment, the trim pieces are sold with a block arrangement as seen in trim piece 180 of FIG. 4A, with instructions to cut off either of the blocks 184 and 186 (and ends of elongate member 182 ) as necessary. Alternatively, trim piece 180 could be constructed so the blocks 184 and 186 are attached to elongate member 182 by a frangible web and are easily detached, although as a practical matter this would require injection molding rather than open cast molding to produce. The trim pieces may be made from polyurethane. The relative dimensions of the decorative trim pieces, such as A and B in FIGS. 4B and 4C, and the length of the elongate members, may be varied to suit the application or particular installation. The style of the decoration or ornamentation and the sizes of the decorative trim pieces may be varied to suit particular installations and applications. In some cases, the overall length of the trim piece would vary from 6 feet to 12 feet with A being around 1¼ inch and B around 1 inch. It would be possible to have the elongate member range from 12 inches to 3 feet to 20 feet or even longer depending upon the application. The lengths A can also vary, being 6 inches, 12 inches or even 36 inches, and length B also varying, with lengths such as 5 inches, 10 inches or 30 inches, FIG. 5 shows the trim pieces used in conjunction with a coving. Turning to FIG. 5, there is a ceiling 210 , and walls 212 , 214 and 216 , Trim pieces 218 , 220 and 222 are attached to the ceiling 210 , while trim pieces 224 , 226 and 228 are attached to walls 212 , 214 and 216 . Covings 230 and 232 are attached to the ceiling and walls to abut the trim pieces, and are mitred at corners 234 and 236 .
Some faces of the blocks in FIGS. 1, 2 , 3 and 4 A- 4 D have been described as “orthogonal” to the central axis of the various trim pieces. It is to be understood that “orthogonal” means orthogonal within the tolerances commonly encountered in the building profession. In particular, the description of the fares as “orthogonal” should be taken to encompass variations from strict orthogonality that would still permit the trim pieces to be effectively used as described in this application.
It should also be recognized by those skilled in the art that similar decorative trims can be produced to fit around inside or outside corners with angles at other than right angles. FIG. 6 shows a decorative trim piece 300 with an elongate member 302 and block 304 . Face 306 is at an obtuse angle 308 to central axis 310 of elongate member 302 , allowing trim piece 300 to be used with corresponding obtuse corners. Similarly, face 312 is at an acute angle to central axis 310 , allowing trim piece 300 to be used with corresponding acute corners.
Those skilled in the art will appreciate that various modifications of detail may be made to the preferred embodiments described herein, which would come within the spirit and scope of the invention as described in the following claims.
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A trim piece is diclosed that allows from easier placement of trim pieces around corners. An elongated member has a block at an end. The block has an abutment face pointed in a direction to extend around a corner and face down the direction for the next trim piece to be placed. The abutment face may alternatively face in the longitudinal direction of the elongate member, or face in a direction for the next trim piece to be placed on the same surface as the first trim piece.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to soft, absorbent and bulky cellulosic fibrous webs which have been treated so that they impart a soothing or emollient effect to the human skin when used for wiping or drying while essentially retaining their water-absorbent property and strength. The agent used in the present invention is a condensation product of an amino acid with a reducing sugar.
HISTORY OF THE PRIOR ART
It has heretofore been suggested to treat cellulosic fibrous webs with lanolin to impart a feeling of softness to the webs. See, for example, Wemyss, et al., 2,877,115 and Yang, 2,944,931 or with other fatty solids, see Britt, 3,305,392 However, such a treatment has the disadvantage that the water absorbency of the cellulosic web is dramatically reduced by the application of these fatty-type materials, so that the web can no longer satisfactorily perform a wiping or drying function in reference to moist skin.
SUMMARY OF THE INVENTION
The present invention has as its object rather than imparting the feeling of softness to cellulosic webs, the imparting to the human skin an emollient or soothing effect through wiping with a cellulosic web while retaining the drying and strength characteristics of the untreated web. In many environments such as hospitals and clinics, persons are required to frequently wash and dry their hands. This can produce skin irritation, particularly in cold weather. Also, persons suffering from the common cold must frequently apply facial tissues. Also people suffering from diarrhea must use large quantities of toilet tissue. Repeated wipings with treated toilet tissue has been found to condition the perineal region so that it maintains a non-irritating condition. Likewise, a soft feeling is achieved after using facial treatment in the manner of this invention so that the nasal skin is left with a velvety soft feeling even after repeated wipes.
The present inventors have found that the water absorbency can essentially be retained while imparting a skin soothing character to webs for drying or wiping the skin by treating soft absorbent cellulosic webs with glucose glutamate. Products made from such webs exhibit the ability to transfer chemicals from the cellulosic fibrous web to the skin generating emollient benefits while concomitantly successfully executing the previous function of the produce which is to wipe or dry the skin. Webs treated with lanolin, by contrast, are markedly inferior in producing the desired benefits and are even perceived in some cases as irritating or to cause itching. This may be attributable, not only to the fact that some people are allergic to lanolin, but also as observed by Jacobi, et al., 3,231,472 dry skin is not caused by the loss of fat material in skin but by the loss of the water soluble constituents therein. In accordance with the present invention, a glucose glutamate condensation product of an amino acid with a reducing sugar is applied to a web of cellulosic fibers in an amount from 0.1 to 2% by weight of the web. The presence of small residual amounts of glucose glutamate on the skin, after hand drying, materially aids in restoring and maintaining the moisture balance necessary for healthy skin. This condensation product is disclosed and described in detail in U.S. Patent 3,231,472, incorporated herein by reference. As will be readily appreciated, the fact that the polymers of the present invention are water-soluble totally distinguishes the treatment of the present invention from that of the lanolin treatments of the prior art. The high molecular weight polymers of the present invention are commercially available from Wickhen Products, Inc., a wholly-owned subsidiary of Dow Corning, under the brand name WICKENOL.
DETAILED DESCRIPTION
For the purpose of illustrating the present invention, paper webs having a basis weight of 54 g/m 2 (32 pounds per ream of 2,880 square feet) were treated in the finishing process at a point after the paper has been unwound from the parent roll and embossed, but before the slitting, folding, cut off stacking and wrapping processes. The treating fluid, comprising the active ingredients dissolved in water, is applied at a rate to yield the addition of between 0.034 to 1.086 g/m 2 (0.02 to 0.64 pounds per ream) of the WICKHEN compound or 0.1 to 2.0% by weight of the web. For toilet tissue such as Scott COTTONELLE or 2-ply facial, another example illustrating the present invention could be paper webs having basis weight of 27 g/m 2 (16 lbs. per ream) of 2,880 square feet were treated at location similar to that disclosed above. The treating fluid comprising the active ingredients dissolved in water is applied at a rate to yield an addition of between 0.017 to 0.543 g/m 2 (0.01 to 0.32 lbs/ream) of the compound or 0.1 to 2% by weight of web.
Any application technique known in the art which does not unduly compact the web and which evenly distributes the fluid at the desired rate onto the paper web may be employed. These application techniques include spraying, transfer roll coating and gravure printing. If compaction caused by gravure printing is considered too great to the finished product, this step may be carried out prior to the step of bulking by embossing. The amount of compaction which can be suffered is influenced by numerous variables much as the original bulk of the web, consumer expectations regarding bulk and the perceived need for patterned printing which can be achieved by gravure roll methods. The present inventors have found that the benefits perceived by users are best achieved by spraying the treating fluid onto the web.
Two sheets were prepared as follows:
EXAMPLE 1
A paper web having a basis weight of 31.2 pounds per ream of 2880 square feet (52.9 grams per square meter) was sprayed on one side of the sheet with a Wickenol formulation containing 3.75% glucose glutamate in solution to yield a lotionized sheet containing 0.27% glucose glutamate by weight of the web.
EXAMPLE 2
A paper web having a basis weight of 33.1 pounds per ream of 2880 square feet (56.2 grams per square meter) was sprayed on one side of the sheet with Alcolac lanolin (RRT-1-200A) containing 5% lanolin in solution to yield a lotionized sheet containing 0.27% lanolin by weight of web.
Towels fabricated from sheets made in accordance with the preceding examples 1 and 2 and a control towel were tested by a panel of nurses to evaluate the condition of their hands after repeated drying of their hands. Sensory perceptions are, of course, subjective; however, the results, it is believed, validly rank the towels in relation to one another. The test procedure asked participants to compare the condition of their hands after four dryings with a control towel against four dryings with a test towel. The control towel consisted of untreated paper towels, commercially available as SCOTT Brand 150 C-fold towels. All test towels were kinder to the participants' hands than the control towel, as evidenced by the percentage stating their hands felt the same or better after the dryings. The length of time it took to dry hands with the control towel and the test towels was the same. On average, the drying time was sixteen seconds. The testing procedure comprised a wash and dry sequence as follows: one wash and dry with control towel, followed by one with test towel; four wash and dry sequences with control towel followed by four with test towel; and finally five with test towel. In the test of towels made in accordance with Example 1 (Wickenol), at the end of the test 58% of the participants said their hands felt better, 17% said they felt the same and 25% said their hands felt worse. In the test of towels made in accordance with Example 2 (lanolin) at the end of the test, 27% of the participants said their hands felt better, 9% said they felt the same and 64% said their hands felt worse.
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Disclosed are soft, absorbent and bulky cellulosic fibrous webs which have been treated so that they impart a soothing or emollient effect to the human skin when used for wiping or drying while essentially retaining their water-absorbent property and strength. The agent used in the present invention is a condensation product of an amino acid with a reducing sugar.
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FIELD OF THE INVENTION
The present invention relates to a method of and apparatus for high-speed scanning of printed electromagnetic field levels and is particularly concerned with testing circuit packages and like devices.
BACKGROUND OF THE INVENTION
An important tool in circuit board design is the ability to easily and accurately locate and measure electromagnetic emissions from an operating circuit board. The prior art electronic emission monitors are represented by Canadian Letters Patent 1,286,724 assigned to Northern Telecom Limited, granted on Jul. 23, 1991; U.S. Pat. No. 4,829,238 granted on May 9, 1989; U.S. Pat. No. 5,006,788 granted on Apr. 9, 1991; and, U.S. Pat. No. 5,218,294. These patents describe a method and apparatus for monitoring electromagnetic emission levels from operating printed circuit boards.
The prior art enabled the user to carry out two types of scans: spectral, that is, signal strength relative to the frequency of the scanner, and spatial, that is, signal strength relative to the position of the signal on the printed circuit board. The spectral scan retains only the highest value observed at each frequency point, regardless of the probe, and the display is, therefore, merely a profile of peak electromagnetic amplitudes plotted against frequency. All other readings are discarded. A spatial scan takes a reading of the signal level at the designated frequency, for each probe within the selected scan area. The scan results are retained in a display file which provides a color coded map of the current flows (signal strength) in the scan area at the defined frequency. The amount of time required to complete the scan is in the range of 95 seconds.
The disadvantages and limitations associated with the prior art apparatus relate to the fact that it cannot scan the board under test fast enough for use in production line testing. To be effective in such an application requires an method and apparatus for gathering spectral information from all locations of the printed circuit board under test in much less than one second.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved method and apparatus for monitoring electromagnetic field levels from printed circuit board.
In accordance with an aspect of the present invention there is provided an apparatus for testing a device for electromagnetic field therefrom, the apparatus comprising: probe means positionable in a plurality of predetermined positions immediately adjacent to the device, said predetermined positions having a known spatial arrangement; addressing means for successively addressing the probe means at each predetermined position; a receiver connected to said addressing means for measuring current induced in the probe means by electromagnetic field from respective immediate adjacent regions of the device under test; signal processing means for analyzing electrical outputs from the probe means to obtain a measure of electromagnetic field levels immediately adjacent the device under test associated with each predetermined position; spectrum analyzer means to gather and analyze spectral information; digital computing means to convert the analog output of the spectrum analyzer means to a digital output; calibration means to calibrate the digital output.
In a further embodiment of the present invention, the spectrum analyzer output is connected to an analog to digital converter via the “video out” output socket.
In yet another embodiment of the present invention, the initial analog to digital conversion is triggered to start the sweep of the printed circuit board under test by the electromagnetic scanning apparatus thereby synchronizing the operation of the device under test with the scanning apparatus allowing the collection of scanning data with respect to time.
In an embodiment of the present invention, a spectral scan of the device under test is obtained resulting in a display of the profile of peak amplitudes plotted against frequency. Several peaks are chosen by the computer system and the frequency of each peak is recorded. From the frequencies of these peaks, a piece wise linear frequency calibration curve is produced.
Another aspect of this invention is directed to a method of high-speed scanning of electromagnetic field levels comprising the steps of: placing a device under test immediately adjacent to a probe means which comprising a plurality of probes, each probe having a predetermined position within the probe means; addressing a first probe of the plurality of probes, then synchronizing a spectrum analysis sweep to commence at the same point in time of the activity of the device under test; measuring electromagnetic field levels from the device under test as detected by the first probe, and, using a spectrum analyzer, sweep across a desired frequency range generating a video output signal; digitizing this video output signal, level calibrating the digitized video output signal and saving the individual data so obtained. Furthermore, these steps can be optionally repeated for each probe of the plurality of probes as required and the steps between the individual data of the digitized data set frequency calibrated, and optionally waiting one sample time more, followed by repeating the above steps for each possible sample time for each probe of the plurality of probes, and displaying the calibrated data set.
In another embodiment of the present invention a method is provided whereby measured level of electromagnetic radiation from the device under test is calibrated. The “Cal Out” output of the spectrum analyzer is serially connected via an attenuating means of 40 dB to the spectrum analyzer input.
Particularly for testing a device for electromagnetic field therefrom, the apparatus can further include a memory at which circuit layout design data is stored, and means for inputting said circuit layout design data to the controller means, said controller means being operable to generate a circuit layout map from the circuit layout design data and said display being means operable simultaneously to display said map of electromagnetic field level measures and said circuit layout with said maps superimposed.
In accordance with the present invention, a spectral analyzer is placed in series with the electromagnetic probe array.
In accordance with another embodiment of the invention, the “video out” terminal of the spectral analyzer is connected to a high speed analog to digital (A/D) converter.
By using a spectral-spatial scan, the present invention seeks to overcome the disadvantages found in the prior art. The use of a spectral-spatial scan makes it possible to measure electromagnetic fields from devices under test orders of magnitude faster than prior art scanner apparatus. The increased scanning speeds enable the user to build large data structures of scan data. In addition, the systems provide powerful manipulative, comparative and analytical tools which allows multiple perspectives of the scan results, thus establishing a new level of visualization capabilities.
A further objective of the present invention is to provide a device of the character herewithin described which permits the production of improved products; significantly reduces pre-compliance times with a consequent reduction in the time to market of the device under test; reduced re-engineering or modification costs; cost effective means for ensuring on-going electromagnetic field compliance with preset standards; and, minimized life-cycle costs for the product. The spectral-spatial scan system provide a low cost, automated, non-contacting, testing of a devices quality and a testing of their performance on the manufacturing line.
BRIEF DESCRIPTION OF DRAWINGS
The present invention will be further understood from the following description with references to the drawings in which:
FIG. 1 illustrates known art scanning apparatus;
FIG. 2 illustrates, in a block diagram, a high-speed scanning apparatus in accordance with an embodiment of the present invention;
FIG. 3 illustrates in a flow chart a calibration method in accordance with an embodiment of the present invention;
FIG. 4 graphically illustrates the amplitude verses frequency spectrum collected by the apparatus of FIG. 2 with a window superimposed upon a peak in the spectrum in accordance with the method of FIG. 3;
FIG. 5 graphically illustrates evaluation of a peak for suitability as a calibration point in accordance with the method of FIG. 3;
FIG. 6 graphically illustrates narrow span sweep of the peak in accordance with the method of FIG. 3;
FIG. 7 illustrates a sample piece-wise linearization curve used by the method of FIG. 3 to calibrate the frequency of the collected spectrum data;
FIG. 8 illustrates in a flow chart a method of spectrum amplitude calibration in accordance with an embodiment of the present invention;
FIG. 9 illustrates an apparatus set-up used for the method of FIG. 8;
FIG. 10 graphically illustrates an exemplary amplitude calibration curve obtained by the method of FIG. 8; and
FIG. 11 graphically illustrates an exemplary time-frequency-level plot obtained by the method of Chart B.
DETAILED DESCRIPTION
In the known apparatus, as shown in FIG. 1, the method for testing a device for electromagnetic fields therefrom, the method comprising positioning an array of electromagnetic field monitoring probes occupying predetermined positions within the array immediately adjacent to the device under test, successively addressing the probes to measure detected current induced in the probes by electromagnetic field from respective immediately adjacent regions of the device under test, and analyzing electrical outputs from the probes to obtain a position-dependent measure of electromagnetic fields immediately adjacent to the device under test.
For example, a co-pending device described in Canadian Patent Application 2,161,292 has a electromagnetic sweep range of plus one gigahertz (+1 GHz). Using a 100 KHz bandwidth, a minimum of 20,000 readings would be necessary to cover all of the information contained in the electromagnetic spectrum under analysis. The internal digitizer of the spectrum analyzer on the prior art apparatus would require 34 separate sweeps with each sweep taking 100 msec to complete. This speed is not adequate for high speed production applications. One method to increase the speed of the spectral scanner is to connect an external high-speed digitizer. However, the only available output is the “video out” output of the spectrum analyzer. This output is not calibrated and therefore would yield inconsistent scanning results.
Referring to FIG. 2, there is illustrated in a block diagram, a high-speed scanning apparatus in accordance with an embodiment of the present invention. The high-speed scanning apparatus includes an electromagnetic scanning (EMSCAN) probe array 10 , a spectrum analyzer 12 , a computer 14 having an analog-to-digital (A/D) converter 16 , a synchronization (SYNC) block 18 for testing the electromagnetic radiation emitted by the device under test (DUT) 20 . The EMSCAN probe array 10 is connected to the spectrum analyzer 12 and the computer 14 via an IEEE 488 bus 22 . The spectrum analyzer 12 is connected to an A/D connecter via a video out line 24 and a blanking out line 26 . The computer 14 is connected to the SYNC block 18 via a line 28 to provide a ready or arm signal thereto. The SYNC block 18 has an input/output port connected to the DUT 20 , for receiving from or sending to the DUT 20 , a sync signal via a sync signal line 30 . The SYNC block 18 has an output coupled to the spectrum analyzer 12 via a first trigger line 32 and to the A/D converter 16 via a second trigger line 34 .
In operation, a high-speed scan is accomplished by externally digitizing the video out signal, provided on the video out line 24 , in the A/D converter 16 . The digitizing process is initiated in synchronization with the spectrum analyzer. Optionally, the synchronization signal can be applied to the device under test (DUT) 20 or alternatively, can be received from the DUT 20 . The synchronization is accomplished by the SYNC block 18 . The SYNC block 18 first receives a ready signal form the computer 14 , then in one mode of operation sends a sync signal to the DUT 20 and trigger signals to the spectrum analyzer 12 and A/D converter 16 . Thus, activity in the DUT 20 and both the spectrum analyzer and the A/D converter are synchronized.
In another mode of operation, the armed SYNC block 18 receives a synchronization signal, generated by the DUT 20 , and in response thereto, sends trigger signals to the spectrum analyzer 12 and the A/D converter 16 . The A/D converter 16 uses the video blanking signal from the spectrum analyzer 12 to stop its digitization process. The spectrum analyzer, for example, may be a Hewlett-Packard 8594E.
In order to consistently map a predetermined number of data points for each sweep of the spectrum analyzer, data interpolation or decimation is performed upon the digitized data output from the A/D converter. For example, at a sampling rate of 100 kHz and a sweep time of one second, each sweep of the spectrum analyzer would provide 100,000 data points. However, the blanking signal used by the A/D converter 16 to stop digitizing data likely does not have sufficient accuracy to ensure that precisely 1100,000 data points are generated. In this event, the data are interpolated or decimated such that exactly the predetermined number of data points or samples result from each sweep.
The step of the high-speed measurement process are summarized in the following chart:
CHART A
HIGH-SPEED MEASUREMENT PROCESS
Step
Process
1.
Setup the spectrum analyzer and read back the sweep time.
(FIG. 2)
2.
Select the first Emscan probe.
3.
Set the “Ready Line” and arm the Synchronizer.
4.
The synchronizer waits until the DUT is ready or runs
immediately for unsynchronized scans. The spectrum
analyzer's sweep and the Analog to Digital Converter (A/D)
are then triggered.
5.
The A/D digitizes the signal at the spectrum analyzer's
“Video Out” and “Blanking Out” for a duration of the sweep
time plus a percentage.
6.
Determine the end of sweep from the digitized blanking data.
7.
Linearly rescale the ‘Video Out’ data to correct to the number
of digitized points desired.
8.
Apply the Level Calibration formula to the data. Note: this
formula is only determined from time to time (once per
month).
9.
Step to the next Emscan probe and repeat step 3-8 until the
last probe is completed. The spectral data for each probe is
stored in an array.
10.
Run the Frequency calibration algorithm.
11.
Display the data.
Referring to FIG. 3, there is illustrated in a flow chart, a calibration method in accordance with an embodiment of the present invention. Once the data has been collected in accordance with steps 1-9 of Chart A, at step 10, the frequency calibration method of FIG. 3 is applied as follows. The first step as represented by a block 100 is to find the highest peak in each of several windows, evenly spaced across the frequency range as illustrated in FIG. 4 . Then, as represented by a block 102 , based upon a minimum level and the area under the peak evaluate the peaks in each window for acceptability for use as a calibration point as illustrated in FIG. 5 . Then as represented by a block 104 , find the uncalibrated frequency of the first acceptable peak. Then, as represented by a block 106 , set the spectrum analyzer center frequency to that frequency. Then, as represented by a block 108 , set the spectrum analyzer span to a small percentage of the original span. Then, as represented by a block 110 , take a sweep with the spectrum analyzer. As represented by a block 112 , move the spectrum analyzer's marker to the peak, as illustrated in FIG. 6 . In a block 114 determine the frequency of that marker (peak). At a block 116 repeat from steps 3-8 for each acceptable peak. Then, as represented by block 118 , generate a piece-wise linearization curve from the measured values, as illustrated in FIG. 7 . Finally, as represented by a block 120 , use this curve to adjust the displayed spectrum to the calibrated frequency.
Referring to FIG. 8, there is illustrated, an a flow chart, a method of spectrum amplitude calibration in accordance with an embodiment of the present invention. For the apparatus of FIG. 2, at the spectrum analyzer 12 attach “Cal Out” to “In” through a 40 dB attenuator, as shown in FIG. 9, as represented by a block 200 . Set the spectrum analyzer Reference Level and Attenuation Level so that the trace falls on the bottom graticule, as represented by a block 202 . Measure the voltage on the “Video Out”, as represented by a block 204 . Increase the spectrum analyzer Reference Level and Attenuation Level so that the trace falls on the next graticule, as represented by a block 206 . Repeat steps 3 and 4 until the top graticule has been measured, as represented by a block 208 . Calculate a calibration formula from the data, as represented by a block 210 . The formula is a least square fit to a straight line, i.e. Y=aX+b, as illustrated in FIG. 7 .
Once the set-up of FIG. 2 has been calibrated, thereby allowing high-speed scanning, collection of time related data becomes practical. There are two methods for collecting time related data: single probe multiple frequency (spectral); and single frequency multiple probes (spatial).
To gather single frequency multiple probe data, the spectrum analyzer Center Frequency is set to the desired frequency at zero span and the output is digitized for each probe for the duration under consideration. The start of the digitization is synchronized to the activity on the DUT. Detailed steps are given hereinbelow in Chart B.
CHART B
SINGLE FREQUENCY SCANNING
Step
Process
1.
Set up the spectrum analyzer for the desired Center
Frequency, Bandwidths, etc. Set it to zero span and turn
the sweep off.
2.
Select the desired probe.
3.
Wait for a trigger signal for the DUT.
4.
Digitize the ‘Video Out’ of the spectrum analyzer for the
duration desired and save the data.
5.
Select another probe and repeat steps 3-4.
6.
Display the data.
To gather single probe spectral data, the spectrum analyzer is setup for the desired spectrum sweep and a single probe is selected. The spectrum analyzer sweep is triggered at time 0 of the activity on the DUT and the data collected. The spectrum analyzer is then triggered at time 0 +1n sample duration(s) and process is repeated until data has been collected for the desired time intervals. Note: multiple probes could be scanned in this fashion to produce a data set of position verses time and frequency. That is a combination of the two types of scans. Detailed steps are given hereinbelow in Chart C.
CHART C
SINGLE PROBE TIME SCANNING
Step
Process
1.
Setup the spectrum analyzer and read back the sweep
time. (FIG. 2)
2.
Select an Emscan probe.
3.
Set the ‘Ready Line’ and arm the Synchronizer.
4.
The synchronizer waits until the DUT is ready. The
spectrum analyzer's sweep and the Analog to Digital
Converter (A/D) are then triggered.
5.
The A/D digitizes the signal at the spectrum analyzer's
‘Video Out’ And ‘Blanking Out’ for a duration of the sweep
time plus a percentage.
6.
Determine the end of sweep from the digitized blanking
data.
7.
Linearly rescale the ‘Video Out’ data to correct to the
number of digitized points desired.
8.
Apply the Level Calibration formula to the data. Note: this
formula is only determined from time to time (once per
month).
9.
Repeat step 3-8 waiting one sample time more each time
until the desired duration has passed. (FIG. 11) The
spectral data for sample time is stored in an array.
10.
Run the Frequency calibration algorithm.
Note: for a combination time scan, select another probe
and repeat steps 2-10 until all the desired probes are
scanned.
11.
Display the data.
Numerous modifications, variations, and adaptations may be made to the particular embodiments of the invention described above without departing from the scope of the invention, which is defined in the claims.
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A method and apparatus for high-speed scanning of electromagnetic emission levels includes a synchronizer for synchronizing scanning of a device under test with digitizing a output video signal from a spectrum analyzer. The synchronizer can be responsive to a synchronization signal from the device under test or can generate a synchronization signal to the device under test. Methods for calibrating the level and frequency of the video output signal are provided. Once calibrated the high-speed scanning can be used to develop single probe multifrequency/time scans yielding amplitude versus frequency and time plots, and single frequency multiple probe/time scans yielding amplitude versus space and time plots.
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